Hydrogenated Conjugated Diene-Based Polymer, Hydrogenated Conjugated Diene-Based Polymer Composition, Rubber Composition, and Method for Producing Hydrogenated Conjugated Diene-Based Polymer

Abstract

A hydrogenated conjugated diene-based polymer of the present invention has a branch number (Bn) measured by viscosity detector-equipped GPC-light scattering measurement of 2.5 or more, and a hydrogenation rate of a structural unit derived from a conjugated diene compound of 30% or more and less than 99%.

Claims

1. A hydrogenated conjugated diene-based polymer, having a branch number (Bn) measured by viscosity detector-equipped GPC-light scattering measurement of 2.5 or more, and a hydrogenation rate of a structural unit derived from a conjugated diene compound of 30% or more and less than 99%.

2. The hydrogenated conjugated diene-based polymer according to claim 1, having a weight average molecular weight measured by GPC of 210,000 or more and less than 3,000,000.

3. The hydrogenated conjugated diene-based polymer according to claim 1, wherein assuming that composition ratios (% by mol) of a structural unit represented by the following formula (1), a structural unit represented by the following formula (2), a structural unit represented by the following formula (3), and a structural unit represented by the following formula (4) are a, b, c, and d, respectively, the following expression (S) is satisfied: ##STR00009##

4. The hydrogenated conjugated diene-based polymer according to claim 1, wherein assuming that composition ratios (% by mol) of a structural unit represented by the following formula (1) and a structural unit represented by the following formula (2) are a and b, respectively, the following expression (T) is satisfied: ##STR00010##

5. The hydrogenated conjugated diene-based polymer according to claim 1, comprising 3% by mass or more and less than 60% by mass of an aromatic vinyl monomer.

6. The hydrogenated conjugated diene-based polymer according to claim 1, wherein the modification ratio is 60% by mass or more.

7. The hydrogenated conjugated diene-based polymer according to claim 1, wherein the branch number (Bn) measured by viscosity detector-equipped GPC-light scattering measurement is 8.0 or more.

8. The hydrogenated conjugated diene-based polymer according to claim 1, comprising a star polymer structure having 3 branches or more, comprising, in a branched chain of at least one star structure, a portion derived from a vinyl-based monomer containing an alkoxysilyl group or a halosilyl group, and further comprising a main chain branch structure in the portion derived from a vinyl-based monomer containing an alkoxysilyl group or a halosilyl group.

9. The hydrogenated conjugated diene-based polymer according to claim 8, wherein the portion derived from a vinyl-based monomer containing an alkoxysilyl group or a halosilyl group is a monomer unit based on a compound represented by the following formula (5) or (6), the hydrogenated conjugated diene-based polymer comprises a branch point of a polymer chain formed by the monomer unit based on the compound represented by the following formula (5) or (6), and at least one end of the hydrogenated conjugated diene-based polymer is coupled with a coupling agent; ##STR00011## wherein R.sup.1 represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and may have a branch structure in a part thereof; R.sup.2 and R.sup.3 each independently represent an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and may have a branch structure in a part thereof; each of R.sup.1 to R.sup.3, if present in a plural number, is respectively independent; X.sup.1 represents a halogen atom, and if present in a plural number, each X.sup.1 is respectively independent; m represents an integer of 0 to 2, n represents an integer of 0 to 3, l represents an integer of 0 to 3, and (m+n+1) is 3: ##STR00012## wherein R.sup.2 to R.sup.5 each independently represent an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and may have a branch structure in a part thereof; each of R.sup.2 to R.sup.5, if present in a plural number, is respectively independent; X.sup.2 and X.sup.3 each independently represent a halogen atom, and each of X.sup.2 and X.sup.3, if present in a plural number, is respectively independent; m represents an integer of 0 to 2, n represents an integer of 0 to 3, l represents an integer of 0 to 3, and (m+n+l) is 3; and a represents an integer of 0 to 2, b represents an integer of 0 to 3, c represents an integer of 0 to 3, and (a+b+c) is 3.

10. The hydrogenated conjugated diene-based polymer according to claim 9, comprising a monomer unit based on a compound represented by the formula (5) wherein R.sup.1 is a hydrogen atom, and m is 0.

11. The hydrogenated conjugated diene-based polymer according to claim 9, comprising a monomer unit based on a compound represented by the formula (6) wherein m is 0 and b is 0.

12. The hydrogenated conjugated diene-based polymer according to claim 9, comprising a monomer unit based on a compound represented by the formula (5) wherein R.sup.1 is a hydrogen atom, m is 0, l is 0, and n is 3.

13. The hydrogenated conjugated diene-based polymer according to claim 9, comprising a monomer unit based on a compound represented by the formula (6) wherein m is 0, l is 0, n is 3, a is 0, b is 0, and c is 3.

14. The hydrogenated conjugated diene-based polymer according to claim 1, wherein a ratio of a component having a molecular weight of 300,000 or less (component LM) is 20% or more and 80% or less.

15. The hydrogenated conjugated diene-based polymer according to claim 1, wherein the hydrogenation rate is 50% or more and 75% or less.

16. A method for producing a hydrogenated conjugated diene-based polymer comprising the following steps (A) and (E), and at least one of the following steps (B) and (D), a hydrogenated conjugated diene-based polymer obtained in the step (E) having a branch number (Bn) measured by viscosity detector-equipped GPC-light scattering measurement of 2.5 or more, and a hydrogenation rate of a structural unit derived from a conjugated diene compound of 30% or more and less than 99%, the method comprising: a step (A) of polymerizing only a conjugated diene compound, or a conjugated diene compound and an aromatic vinyl compound to obtain conjugated diene-based polymer; a step (B) of reacting an end of the conjugated diene-based polymer with a branching agent to obtain a conjugated diene-based polymer solution containing a branched conjugated diene-based polymer having an active end; a step (D) of reacting the end of the conjugated diene-based polymer with a coupling agent; and a step (E) of hydrogenating the conjugated diene-based polymer to obtain a hydrogenated conjugated diene-based polymer.

17. The method for producing a hydrogenated conjugated diene-based polymer according to claim 16, comprising the step (D).

18. A hydrogenated conjugated diene-based polymer composition, comprising 100 parts by mass of the hydrogenated conjugated diene-based polymer according to claim 1, and 1 to 60 parts by mass of a rubber softener.

19. A rubber composition comprising a rubber component, and 5.0 parts by mass or more and 150 parts by mass or less of a filler based on 100 parts by mass of the rubber component, wherein the rubber component contains, based on 100 parts by mass of a total amount of the rubber component, 10 parts by mass or more of the hydrogenated conjugated diene-based polymer according to claim 1.

Description

EXAMPLES

[0333] The present embodiment will now be described in more detail with reference to specific examples and comparative examples, and it is noted that the present embodiment is not limited to the following examples and comparative examples at all.

[0334] Various physical properties of the examples and comparative examples were measured by the following methods.

(Mooney Viscosity of Polymer)

[0335] A conjugated diene-based polymer or a hydrogenated conjugated diene-based polymer was used as a sample to measure a Mooney viscosity by using a Mooney viscometer (trade name “VR1132” manufactured by Ueshima Seisakusho Co., Ltd.) in accordance with ISO 289 with an L-type rotor used.

[0336] A measurement temperature was 100° C. when a hydrogenated conjugated diene-based polymer was used as a sample.

[0337] Specifically, first, a sample was preheated at the test temperature for 1 minute, the rotor was rotated at 2 rpm, a torque was measured 4 minutes after, and the thus obtained measured value was defined as a Mooney viscosity (ML.sub.(1+4))

[0338] (Branch Number (Bn))

[0339] A conjugated diene-based polymer or a hydrogenated conjugated diene-based polymer not containing a rubber softener was used as a sample to measure a branch number (Bn) by viscosity detector-equipped GPC-light scattering measurement as follows. A gel permeation chromatography (GPC) measurement apparatus (trade name “GPCmax VE-2001” manufactured by Malvern Panalytical Ltd.) including a series of three columns using a polystyrene-based gel as a filler was used to perform measurement by using three detectors, that is, a light scattering detector, a refractive index (RI) detector, and a viscosity detector (trade name “TDA305” manufactured by Malvern Panalytical Ltd.) connected in the stated order. Based on standard polystyrene, an absolute molecular weight was obtained from results obtained by using the light scattering detector and the RI detector, and an intrinsic viscosity was obtained from results obtained by using the RI detector and the viscosity detector.

[0340] A straight-chain polymer was used under assumption of having an intrinsic viscosity [η]=10.sup.−3.883 M.sup.0.771, and a contracting factor (g′) was calculated as a ratio of the intrinsic viscosity at each molecular weight. It is noted that M represents an absolute molecular weight in the expression.

[0341] Thereafter, the thus obtained contracting factor (g′) was used to calculate a branch number (Bn) defined as g′=6 Bn/{(Bn+1)(Bn+2)}.

[0342] As an eluent, tetrahydrofuran (hereinafter also referred to as “THF”) containing 5 mmol/L of triethylamine was used.

[0343] As the columns, a series of columns of trade names “TSKgel G4000HXL”, “TSKgel G5000HXL” and “TSKgel G6000HXL” manufactured by Tosoh Corporation were connected and used.

[0344] Twenty (20) mg of a sample for the measurement was dissolved in 10 mL of THF to obtain a measurement solution, and 100 μL of the measurement solution was injected into the GPC measurement apparatus for performing the measurement under conditions of an oven temperature of 40° C. and a THF flow rate of 1 mL/min.

[0345] (Weight Average Molecular Weight, and Component Having Molecular Weight of 300,000 or Less (Component LM))

[0346] Measurement Conditions 1: A conjugated diene-based polymer or a hydrogenated conjugated diene-based polymer used as a sample was measured for a chromatogram using a GPC measurement apparatus (trade name “HLC-8320GPC” manufactured by Tosoh Corporation) including a series of three columns using a polystyrene-based gel as a filler with an RI detector (trade name “HLC8020” manufactured by Tosoh Corporation) used, and on the basis of a calibration curve obtained using standard polystyrene, a weight average molecular weight (Mw), a number average molecular weight (Mn), a molecular weight distribution (Mw/Mn), and a component having a molecular weight of 300,000 or less (component LM) of the sample were obtained.

[0347] As an eluent, THF (tetrahydrofuran) containing 5 mmol/L of triethylamine was used. As the columns, trade name “TSKguardcolumn Super MP(HZ)-H” manufactured by Tosoh Corporation connected, as a guard column at a previous stage, to a series of three columns of trade name “TSKgel Super Multipore HZ-H” manufactured by Tosoh Corporation were used.

[0348] Ten (10) mg of a sample for the measurement was dissolved in 10 mL of THF to obtain a measurement solution, and 10 μL of the measurement solution was injected into the GPC measurement apparatus for performing the measurement under conditions of an oven temperature of 40° C. and a THF flow rate of 0.35 mL/min.

[0349] Among various samples having been subjected to the measurement under the above-described measurement conditions 1, a sample having a molecular weight distribution (Mw/Mn) less than 1.6 was subjected again to the measurement under measurement conditions 2 described below. With respect to samples having been subjected to the measurement under the measurement conditions 1 and found to have a molecular weight distribution of 1.6 or more, the samples were subjected to the measurement under the measurement conditions 1.

[0350] Measurement Conditions 2: A conjugated diene-based polymer or a hydrogenated conjugated diene-based polymer used as a sample was measured for a chromatogram using a GPC measurement apparatus including a series of three columns using a polystyrene-based gel as a filler, and on the basis of a calibration curve obtained using standard polystyrene, a weight average molecular weight (Mw), a number average molecular weight (Mn), and a component having a molecular weight of 300,000 or less (component LM) of the sample were obtained.

[0351] As an eluent, THF containing 5 mmol/L of triethylamine was used. As the columns, a guard column of trade name “TSKguardcolumn Super H-H” manufactured by Tosoh Corporation, and columns of trade names “TSKgel SuperH5000”, “TSKgel SuperH6000”, and “TSKgel SuperH7000” manufactured by Tosoh Corporation were used.

[0352] An RI detector (trade name “HLC8020” manufactured by Tosoh Corporation) was used under conditions of an oven temperature of 40° C. and a THF flow rate of 0.6 mL/min. Ten (10) mg of a sample for the measurement was dissolved in 20 mL of THF to obtain a measurement solution, and 20 μL of the measurement solution was injected into the GPC measurement apparatus for performing the measurement.

[0353] (Modification Ratio)

[0354] A conjugated diene-based polymer or a hydrogenated conjugated diene-based polymer not containing a rubber softener was used as a sample to measure a modification ratio in the polymer by column adsorption GPC as follows. The measurement was performed by applying a characteristic that a modified basic polymer component adsorbs onto a GPC column using a silica-based gel as a filler.

[0355] A modification ratio was obtained by measuring an amount of adsorption onto a silica-based column based on a difference between a chromatogram measured by using a polystyrene-based column and a chromatogram measured by using a silica-based column obtained from a sample solution containing a sample and low molecular weight internal standard polystyrene.

[0356] Specifically, the measurement was performed as described below. A sample found to have a molecular weight distribution of 1.6 or more by the measurement under the measurement conditions 1 of (Weight Average Molecular Weight) was measured under the following measurement conditions 3, and a sample found to have a molecular weight distribution less than 1.6 was measured under the following measurement conditions 4.

[0357] Preparation of Sample Solution: Ten (10) mg of a sample and 5 mg of standard polystyrene were dissolved in 20 mL of THF to obtain a sample solution.

[0358] Measurement Conditions 3: GPC measurement conditions using polystyrene-based column:

[0359] An apparatus of trade name “HLC-8320GPC” manufactured by Tosoh Corporation was used, THF containing 5 mmol/L of triethylamine was used as an eluent, and 10 μL of the sample solution was injected into the apparatus to obtain a chromatogram using an RI detector under conditions of a column oven temperature of 40° C. and a THF flow rate of 0.35 mL/min. As the columns, a series of three columns of trade name “TSKgel Super Multipore HZ-H” and a guard column of trade name “TSKguardcolumn SuperMP(HZ)-H” manufactured by Tosoh Corporation connected at a previous stage were used.

[0360] Measurement Conditions 4: THF containing 5 mmol/L of triethylamine was used as an eluent, and 20 μL of the sample solution was injected into the apparatus to perform the measurement. As the columns, a guard column of trade name “TSKguardcolumn Super H-H” manufactured by Tosoh Corporation and columns of trade names “TSKgel Super H5000”, “TSKgel Super H6000”, and “TSKgel Super H7000” manufactured by Tosoh Corporation were used. A chromatogram was obtained by performing the measurement by using an RI detector (HLC8020, manufactured by Tosoh Corporation) under conditions of a column oven temperature of 40° C. and a THF flow rate of 0.6 mL/min.

[0361] GPC Measurement Conditions Using Silica-Based Column:

[0362] An apparatus of trade name “HLC-8320GPC” manufactured by Tosoh Corporation was used, THF was used as an eluent, and 50 μL of the sample solution was injected into the apparatus to obtain a chromatogram by using an RI detector under conditions of a column oven temperature of 40° C. and a THF flow rate of 0.5 mL/min. A series of columns of trade names “Zorbax PSM-1000S”, “PSM-3005” and “PSM-60S”, and a guard column of trade name “DIOL 4.6×12.5 mm 5 micron” connected at a previous stage were used.

[0363] Calculation Method for Modification Ratio:

[0364] It was assumed that the whole peak area of the chromatogram obtained by using the polystyrene-based column was 100, that a peak area of a sample was P1, and that a peak area of standard polystyrene was P2. It was also assumed that the whole peak area of the chromatogram obtained by using the silica-based column was 100, that a peak area of the sample was P3, and that a peak area of standard polystyrene was P4. Based on P1 to P4, a modification ratio (%) in the polymer was obtained in accordance with the following expression:

Modification ratio (%)=[1−(P2×P3)/(P1×P4)]×100

wherein P1+P2=P3+P4=100.

[0365] (Molecular Weight Obtained by GPC-Light Scattering Measurement (Absolute Molecular Weight))

A conjugated diene-based polymer or a hydrogenated conjugated diene-based polymer not containing a rubber softener was used as a sample, and a GPC-light scattering measurement apparatus including a series of three columns using a polystyrene-based gel as a filler was used to measure a chromatogram for obtaining a weight average molecular weight (Mw-i) (also designated as an “absolute molecular weight”) based on the viscosity of a solution and a light scattering method.

[0366] As an eluent, a mixed solution of tetrahydrofuran and triethylamine (THE in TEA: prepared by mixing 5 mL of triethylamine with 1 L of tetrahydrofuran) was used.

[0367] As the columns, a series of a guard column of trade name “TSKguardcolumn HHR-H” manufactured by Tosoh Corporation, and columns of trade names “TSKgel G6000HHR”, “TSKgel G5000HHR”, and “TSKgel G4000HHR” were connected and used.

[0368] A GPC-light scattering measurement apparatus (trade name “Viscotek TDAmax” manufactured by Malvern Panalytical Ltd.) was used under conditions of an oven temperature of 40° C. and a THF flow rate of 1 mL/min. Ten (10) mg of a sample for the measurement was dissolved in 20 mL of THF to obtain a measurement solution, and 200 μL of the measurement solution was injected into the GPC measurement apparatus for the measurement.

[0369] (Amount of Bound Styrene, Hydrogenation Rate, Expression (S), and Expression (T))

[0370] A conjugated diene-based polymer or a hydrogenated conjugated diene-based polymer not containing a rubber softener was used as a sample to measure the amount of bound styrene in the polymer, and a composition ratio (% by mol) among the structural unit represented by the formula (1), the structural unit represented by the formula (2), the structural unit represented by the formula (3) and the structural unit represented by the formula (4), and measurement was performed with a nuclear magnetic resonance apparatus (.sup.1H-NMR) under the following conditions for calculating a hydrogenation rate of a double bond in a structural unit derived from 1,3-butadiene (hereinafter also simply referred to as the “hydrogenation rate”), a value of the expression (S), and a value of the expression (T). The conditions for the .sup.1H-NMR measurement were as follows:

[0371] (Measurement Conditions)

[0372] Measurement apparatus: JNM-LA400 (manufactured by JEOL Ltd.)

[0373] Solvent: deuterated chloroform

[0374] Measurement sample: product extracted before and after hydrogenation of polymer

[0375] Sample concentration: 50 mg/mL

[0376] Observing frequency: 400 MHz

[0377] Chemical shift reference: TMS (tetramethylsilane)

[0378] Pulse delay: 2.904 sec

[0379] Scan frequency: 64 times

[0380] Pulse width: 45°

[0381] Measurement temperature: 26° C.

[0382] (Cold Flow)

[0383] A conjugated diene-based polymer (composition) or a hydrogenated conjugated diene-based polymer (composition) was used as a sample for measurement. As for cold flow, a load of 1 kg was applied to a sample in a size of 40 mm×40 mm×50 mm in thickness (H0) at 25° C., the resultant was left to stand for 60 minutes to obtain a resultant thickness (H60), and a change rate (%) of the thickness was calculated in accordance with the following expression:

Thickness change rate (%)=(H0−H60)×100/H0

[0384] A result of each of Comparative Examples 2 to 5, and Examples 1, 2, 4, 5 and 31 was expressed as an index obtained by assuming that a result of Comparative Example 1 was 100. A result of each of Examples 6 to 8 was expressed as an index obtained by assuming that a result of Comparative Example 6 was 100. A result of each of Examples 9 to 11 was expressed as an index obtained by assuming that a result of Comparative Example 7 was 100. A result was expressed as an index obtained by assuming that a result of Comparative Example 8 was 100. A result of each of Examples 15 to 17 was expressed as an index obtained by assuming that a result of Comparative Example 9 was 100.

[0385] A result of each of Comparative Examples 11 and 12, and Examples 18 to 23 was expressed as an index obtained by assuming that a result of Comparative Example 10 was 100. A result of each of Examples 24 to 26 was expressed as an index obtained by assuming that a result of Comparative Example 13 was 100. A result of each of Examples 27 to 29 was expressed as an index obtained by assuming that a result of Comparative Example 14 was 100. A result of Example 30 was expressed as an index obtained by assuming that a result of Comparative Example 15 was 100. A result of each of Examples 32 and 33 was expressed as an index obtained by assuming that a result of Comparative Example 16 was 100.

[0386] A lower index indicates that cold flow of a rubber bale during storage is small, and hence handleability is excellent.

[0387] A sample having an index of 79 or less is evaluated as very good (shown as ⊚⊚ in tables), a sample having an index of 80 to 89 is evaluated as good (shown as ⊚ in tables), a sample having an index of 90 to 99 is evaluated to have no practical problem (shown as ◯ in tables), a sample having an index of 100 to 105 is evaluated as rather poor (shown as Δ in tables), and a sample having an index of 105 or more is evaluated to have a practical problem (shown as X in tables).

[0388] (Preparation of Hydrogenation Catalyst)

[0389] A hydrogenation catalyst to be used for preparing a hydrogenated conjugated diene-based polymer in each of the examples and comparative examples described below was prepared by the following method.

[0390] A reaction vessel equipped with a stirrer, which had been subjected to nitrogen substitution, was charged with 1 L of dried and purified cyclohexane. Next, 100 mmol of bis(η5-cyclopentadienyl)titanium dichloride was added thereto. A n-hexane solution containing 200 mmol of trimethylaluminum was added thereto under sufficient stirring, followed by reaction at room temperature for about 3 days. Thus, a hydrogenation catalyst (T) was obtained.

[0391] (Structure of Branching Agent)

[0392] In each of the examples and comparative examples described below, trimethoxy(4-vinylphenyl)silane (BS-1) or dimethoxymethyl(4-vinylphenyl)silane (B2-2) was used as the branching agent, both of which are monomer units based on a compound represented by the following formula (5).

[0393] Trimethoxy(4-vinylphenyl)silane (BS-1) had a structure of the formula (5) in which R.sup.1 is hydrogen, R.sup.2 and R.sup.3 are methyl groups, m is 0, n is 3, and l is 0.

[0394] Dimethoxymethyl(4-vinylphenyl)silane (BS-2) had a structure of the formula (5) in which R.sup.1 is hydrogen, R.sup.2 and R.sup.3 are methyl groups, m is 1, n is 2, and l is 0.

##STR00008##

[0395] In the formula (5), R.sup.1 represents a hydrogen atom, an alky group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and may have a branch structure in a part thereof.

[0396] R.sup.2 and R.sup.3 each independently represent an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms, and may have a branch structure in a part thereof.

[0397] Each of R.sup.1 to R.sup.3, if present in a plural number, is respectively independent.

[0398] X.sup.1 represents a halogen atom. If present in a plural number, each X.sup.1 is respectively independent.

[0399] m represents an integer of 0 to 2, n represents an integer of 0 to 3, and l represents an integer of 0 to 3, and (m+n+1) is 3.

(Comparative Example 1) Hydrogenated Conjugated Diene-Based Polymer (Sample B1

[0400] A temperature-controllable autoclave having an internal volume of 40 L, and equipped with a stirrer and a jacket was used as a reactor, and 2,220 g of 1,3-butadiene, 780 g of styrene, and 21,000 g of cyclohexane, from which impurities had been removed, and 30 mmol of tetrahydrofuran (THF) and 15 mmol of 2,2-bis(2-oxolanyl)propane (BOP) used as polar materials were put in the reactor, and the internal temperature of the reactor was kept at 40° C.

[0401] To the reactor, 18 mmol of n-butyllithium was supplied as a polymerization initiator to star polymerization.

[0402] After starting the polymerization reaction, the internal temperature of the reactor started to increase due to heat generated by the polymerization, and the internal temperature of the reactor finally reached 76° C. Two minutes after reaching this peak of the reaction temperature, 6.0 mmol of N,N-bis(trimethylsilyl)aminopropyl methyltriethoxysilane (compound 1) was added as a coupling agent to the reactor to perform a coupling reaction for 20 minutes. To the resultant polymer solution, 3.0 mmol of methanol was added as a reaction terminator to obtain a solution of a conjugated diene-based polymer.

[0403] To the thus obtained solution of the conjugated diene-based polymer, the hydrogenation catalyst (T) prepared as described above was added in an amount, in terms of Ti, of 60 ppm per 100 parts by mass of the conjugated diene-based polymer, and a hydrogenation reaction was performed at a hydrogen pressure of 0.8 MPa and an average temperature of 85° C. for 1 hour to obtain a solution of a hydrogenated conjugated diene-based polymer. A hydrogenation rate of a butadiene-derived structural unit in the thus obtained hydrogenated conjugated diene-based polymer was 60.0%.

[0404] To the thus obtained solution of the hydrogenated conjugated diene-based polymer, 12.6 g of n-octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)-propionate and 3.0 g of 4,6-bis(octylthiomethyl)-o-cresol were added as antioxidants, the solvent was removed by steam stripping, and the resultant was subjected to a drying treatment with a drier to obtain a hydrogenated conjugated diene-based polymer (Sample B1).

[0405] Analysis results of Sample B1 are shown in Table 1-1. It was found, as a result of measurement, that a structure of a conjugated diene-based polymer obtained before adding the coupling agent in Sample B1 had a linear polymer structure, and did not have a star polymer.

(Comparative Example 2) Conjugated Diene-Based Polymer (Sample B2

[0406] A temperature-controllable autoclave having an internal volume of 40 L, and equipped with a stirrer and a jacket was used as a reactor, and 1,887 g of 1,3-butadiene (initial butadiene), 780 g of styrene, and 21,000 g of cyclohexane, from which impurities had been removed, and 30 mmol of tetrahydrofuran (THF) and 69 mmol of 2,2-bis(2-oxolanyl)propane (BOP) used as polar materials were put in the reactor, and the internal temperature of the reactor was kept at 42° C.

[0407] To the reactor, 92 mmol of n-butyllithium was supplied as a polymerization initiator to start polymerization.

[0408] After starting the polymerization reaction, the internal temperature of the reactor started to increase due to heat generated by the polymerization, and when monomer conversion in the reactor reached 98%, 18 mmol of trimethoxy(4-vinylphenyl)silane (BS-1) was added as a branching agent, followed by stirring for 5 minutes. Thereafter, 333 g of additional 1,3-butadiene (additional butadiene) was added thereto to cause a reaction. A final internal temperature of the reactor was 75° C.

[0409] The internal temperature of the reactor finally reached 76° C. Two minutes after reaching this peak of the reaction temperature, 8.0 mmol of 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane (compound 2) was added as a coupling agent to the reactor to perform a coupling reaction for 20 minutes. To the resultant polymer solution, 5.7 mmol of methanol was added as a reaction terminator to obtain a solution of a conjugated diene-based polymer.

[0410] To the thus obtained solution of the conjugated diene-based polymer, 12.6 g of n-octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)-propionate and 3.0 g of 4,6-bis(octylthiomethyl)-o-cresol were added as antioxidants, the solvent was removed by steam stripping, and the resultant was subjected to a drying treatment with a drier to obtain a conjugated diene-based polymer (Sample B2).

[0411] Analysis results of Sample B2 are shown in Table 1-1.

[0412] In each of a polymer obtained before adding the branching agent, a polymer obtained after adding the branching agent, and a polymer obtained after adding the coupling agent, the structure of the coupled conjugated diene-based polymer was identified based on comparison between a molecular weight obtained by GPC measurement and a branch number obtained by viscosity detector-equipped GPC measurement. Hereinafter, the structure of each sample was similarly identified. As a result of the measurement, as for the structure of Sample B2, a conjugated diene-based polymer obtained after adding the branching agent had a star polymer structure having 3.9 branches on average, and a conjugated diene-based polymer obtained after adding the coupling agent had, in a branched chain of 2 star structures on average, a portion derived from a vinyl-based monomer containing an alkoxysilyl group.

(Comparative Example 3) Hydrogenated Conjugated Diene-Based Polymer (Sample B3

[0413] A temperature-controllable autoclave having an internal volume of 40 L, and equipped with a stirrer and a jacket was used as a reactor, and 1,887 g of 1,3-butadiene (initial butadiene), 780 g of styrene, and 21,000 g of cyclohexane, from which impurities had been removed, and 30 mmol of tetrahydrofuran (THF) and 69 mmol of 2,2-bis(2-oxolanyl)propane (BOP) used as polar materials were put in the reactor, and the internal temperature of the reactor was kept at 42° C.

[0414] To the reactor, 92 mmol of n-butyllithium was supplied as a polymerization initiator to start polymerization.

[0415] After starting the polymerization reaction, the internal temperature of the reactor started to increase due to heat generated by the polymerization, and when monomer conversion in the reactor reached 98%, 18 mmol of trimethoxy(4-vinylphenyl)silane (BS-1) was added as a branching agent, followed by stirring for 5 minutes. Thereafter, 333 g of additional 1,3-butadiene (additional butadiene) was added thereto to cause a reaction. A final internal temperature of the reactor was 75° C.

[0416] The internal temperature of the reactor finally reached 76° C. Two minutes after reaching this peak of the reaction temperature, 8.0 mmol of 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane (compound 2) was added as a coupling agent to the reactor to perform a coupling reaction for 20 minutes. To the resultant polymer solution, 5.7 mmol of methanol was added as a reaction terminator to obtain a solution of a conjugated diene-based polymer.

[0417] To the thus obtained solution of the conjugated diene-based polymer, the hydrogenation catalyst (T) prepared as described above was added in an amount, in terms of Ti, of 60 ppm per 100 parts by mass of the conjugated diene-based polymer, and a hydrogenation reaction was performed at a hydrogen pressure of 0.8 MPa and an average temperature of 85° C. for 30 minutes to obtain a solution of a hydrogenated conjugated diene-based polymer. A hydrogenation rate of a butadiene-derived structural unit in the thus obtained hydrogenated conjugated diene-based polymer was 20.0%.

[0418] To the thus obtained solution of the hydrogenated conjugated diene-based polymer, 12.6 g of n-octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl)-propionate and 3.0 g of 4,6-bis(octylthiomethyl)-o-cresol were added as antioxidants, the solvent was removed by steam stripping, and the resultant was subjected to a drying treatment with a drier to obtain a hydrogenated conjugated diene-based polymer (Sample B3). Sample B3 had a hydrogenation rate of 20%.

[0419] Analysis results of Sample B3 are shown in Table 1-1.

[0420] As a result of measurement, a structure of a conjugated diene-based polymer obtained after adding the branching agent in Sample B3 had a star polymer structure having 3.9 branches on average, and a conjugated diene-based polymer obtained after adding the coupling agent had, in a branched chain of 2 star structures on average, a portion derived from a vinyl-based monomer containing an alkoxysilyl group.

(Examples 1 and 2, and Comparative Example 4) Hydrogenated Conjugated Diene-Based Polymers (Samples B4, B5, and B6, Respectively

[0421] Hydrogenated conjugated diene-based polymers (Sample B4, Sample B5, and Sample B6) were obtained through the same procedures as those of Comparative Example 3 except that an integrated hydrogen flow rate in the hydrogenation reaction was adjusted. Sample B4, Sample B5, and Sample B6 had hydrogenation rates of 63.0%, 92.0%, and 99.5%, respectively.

[0422] Analysis results of Sample B4, Sample B5, and Sample B6 are shown in Table 1-1.

[0423] As a result of measurement, a structure of a conjugated diene-based polymer obtained after adding the branching agent in each of Samples B4, B5 and B6 had a star polymer structure having 3.9 branches on average, and a conjugated diene-based polymer obtained after adding the coupling agent had, in a branched chain of 2 star structures on average, a portion derived from a vinyl-based monomer containing an alkoxysilyl group.

(Comparative Example 5) Hydrogenated Conjugated Diene-based Polymer (Sample B8

[0424] A hydrogenated conjugated diene-based polymer (Sample B8) was obtained in the same manner as in Comparative Example 1 except that the polar material was changed to 19 mmol of 2,2-bis(2-oxolanyl)propane (BOP), that the polymerization initiator was changed to 24 mmol of n-butyllithium, that the coupling agent was changed to 4.3 mmol of 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane (Compound 2), and that the reaction terminator was changed to 5.3 mmol of methanol. Sample B8 had a hydrogenation rate of 96%.

[0425] Analysis results of Sample B8 are shown in Table 1-1.

[0426] It was found, as a result of measurement, that a structure of a conjugated diene-based polymer obtained before adding the coupling agent in Sample B8 had a linear polymer structure, and did not have a star polymer.

(Example 4) Hydrogenated Conjugated Diene-Based Polymer (Sample B9

[0427] A hydrogenated conjugated diene-based polymer (Sample B9) was obtained through the same procedures as those of Comparative Example 3 except that the coupling agent was changed to 4.0 mmol of 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane (Compound 2) and 4.0 mmol of silicon tetrachloride (Compound 3), and that an integrated hydrogen flow rate in the hydrogenation reaction was adjusted. Sample B9 had a hydrogenation rate of 65%.

[0428] Analysis results of Sample B9 are shown in Table 1-1.

[0429] As a result of measurement, a structure of a conjugated diene-based polymer obtained after adding the branching agent in Sample B9 had a star polymer structure having 3.9 branches on average, and a conjugated diene-based polymer obtained after adding the coupling agent had, in a branched chain of 2 star structures on average, a portion derived from a vinyl-based monomer containing an alkoxysilyl group.

(Example 5) Hydrogenated Conjugated Diene-Based Polymer (Sample B10

[0430] A hydrogenated conjugated diene-based polymer (Sample B10) was obtained through the same procedures as those of Comparative Example 3 except that 18 mmol of trimethoxy(4-vinylphenyl)silane (BS-1) was added as the branching agent when monomer conversion in the reactor was 60%, that 7.4 mmol of trimethoxy(4-vinylphenyl)silane (BS-1) was further added as the branching agent when monomer conversion in the reactor was 98%, that 9.8 mmol of 1,3-dimethyl-2-imidazolidinone (Compound 4) was added as a modifier instead of the coupling agent of 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane (Compound 2), that the reaction terminator was changed to 5.3 mmol of methanol, and that an integrated hydrogen flow rate in the hydrogenation reaction was adjusted. Sample B10 had a hydrogenation rate of 65%.

[0431] Analysis results of Sample B10 are shown in Table 1-1.

[0432] As a result of measurement, as for the structure of Sample B10, a structure of a conjugated diene-based polymer obtained after the second addition of the branching agent had a star polymer structure having 5.2 branches on average, and had a portion derived from a vinyl-based monomer containing an alkoxysilyl group.

(Comparative Example 6) Hydrogenated Conjugated Diene-based Polymer (Sample B11

[0433] A hydrogenated conjugated diene-based polymer (Sample B11) was obtained through the same procedures as those of Comparative Example 1 except that the amount of initial butadiene was changed to 2,700 g, that the amount of styrene was changed to 300 g, that the polar material was changed to 4.8 mmol of 2,2-bis(2-oxolanyl)propane (BOP), that the polymerization initiator was changed to 22 mmol of n-butyllithium, that the coupling agent was changed to 7.3 mmol of N,N-bis(trimethylsilyl)aminopropyl methyltriethoxysilane (Compound 1), that the reaction terminator was changed to 3.3 mmol of methanol, and that an integrated hydrogen flow rate was adjusted. Sample B11 had a hydrogenation rate of 60%.

[0434] Analysis results of Sample B11 are shown in Table 1-2.

[0435] It was found, as a result of measurement, that a structure of a conjugated diene-based polymer obtained before adding the coupling agent in Sample B11 had a linear polymer structure, and did not have a star polymer.

(Examples 6, 7, and 8) Hydrogenated Conjugated Diene-Based Polymers (Samples B12, B13, and B14, Respectively

[0436] Hydrogenated conjugated diene-based polymers (Sample B12, Sample B13, and Sample B14) were obtained through the same procedures as those of Comparative Example 3 except that the amount of initial butadiene was changed to 2,295 g, that the amount of styrene was changed to 300 g, that the amount of additional butadiene was changed to 405 g, that the polar material was changed to 21 mmol of 2,2-bis(2-oxolanyl)propane (BOP), that the polymerization initiator was changed to 110 mmol of n-butyllithium, that the branching agent was changed to 35 mmol of dimethoxymethyl(4-vinylphenyl)silane (BS-2), that the coupling agent was changed to 5.9 mmol of N,N,N′,N′-tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (Compound 5), that the reaction terminator was changed to 8.6 mmol of methanol, and that an integrated hydrogen flow rate was adjusted. Sample B12, Sample B13, and Sample B14 had hydrogenation rates of 60.0%, 88.0%, and 93.0%, respectively.

[0437] Analysis results of Sample B12, Sample B13, and Sample B14 are shown in Table 1-2.

[0438] As a result of measurement, a structure of a conjugated diene-based polymer obtained before adding the coupling agent in each of Samples B12, B13 and B14 had a star polymer structure having 3.0 branches on average, and a conjugated diene-based polymer obtained after adding the coupling agent had, in a branched chain of 4 star structures on average, a portion derived from a vinyl-based monomer containing an alkoxysilyl group.

(Comparative Example 7) Hydrogenated Conjugated Diene-Based Polymer (Sample B15

[0439] A hydrogenated conjugated diene-based polymer (Sample B15) was obtained through the same procedures as those of Comparative Example 1 except that the amount of initial butadiene was changed to 1,950 g, that the amount of styrene was changed to 1,050 g, that the polar material was changed to 2.1 mmol of 2,2-bis(2-oxolanyl)propane (BOP), that the polymerization initiator was changed to 19 mmol of n-butyllithium, that the coupling agent was changed to 6.3 mmol of N,N-bis(trimethylsilyl)aminopropyl methyltriethoxysilane (Compound 1), that the reaction terminator was changed to 2.9 mmol of methanol, and that an integrated hydrogen flow rate was adjusted. Sample B15 had a hydrogenation rate of 50%.

[0440] Analysis results of Sample B15 are shown in Table 1-3.

[0441] It was found, as a result of measurement, that a structure of a conjugated diene-based polymer obtained before adding the coupling agent in Sample B15 had a linear polymer structure, and did not have a star polymer.

(Examples 9, 10, and 11) Hydrogenated Conjugated Diene-Based Polymers (Samples B16, B17, and B18, Respectively

[0442] Hydrogenated conjugated diene-based polymers (Sample B16, Sample B17, and Sample B18) were obtained through the same procedures as those of Comparative Example 3 except that the amount of initial butadiene was changed to 1,560 g, that the amount of styrene was changed to 1,050 g, that the amount of additional butadiene was changed to 390 g, that the polar material was changed to 12 mmol of 2,2-bis(2-oxolanyl)propane (BOP), that the polymerization initiator was changed to 146 mmol of n-butyllithium, that the branching agent was changed to 30 mmol of trimethoxy(4-vinylphenyl)silane (BS-1), that the coupling agent was changed to 7.2 mmol of N,N,N′,N′-tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (Compound 5), that the reaction terminator was changed to 0 mmol of methanol, and that an integrated hydrogen flow rate was adjusted. Sample B16, Sample B17, and Sample B18 had hydrogenation rates of 39.0%, 64.0%, and 95.0%, respectively.

[0443] Analysis results of Sample B16, Sample B17, and Sample B18 are shown in Table 1-3.

[0444] As a result of measurement, a structure of a conjugated diene-based polymer obtained before adding the coupling agent in each of Samples B16, B17 and B18 had a star polymer structure having 3.9 branches on average, and a conjugated diene-based polymer obtained after adding the coupling agent had, in a branched chain of 4 star structures on average, a portion derived from a vinyl-based monomer containing an alkoxysilyl group.

(Comparative Example 8) Hydrogenated Conjugated Diene-Based Polymer (Sample B19

[0445] A hydrogenated conjugated diene-based polymer (Sample B19) was obtained through the same procedures as those of Comparative Example 1 except that the amount of initial butadiene was changed to 2,220 g, that the amount of styrene was changed to 780 g, that the polar material was changed to 5.5 mmol of 2,2-bis(2-oxolanyl)propane (BOP), that the polymerization initiator was changed to 19 mmol of n-butyllithium, that the coupling agent was changed to 6.3 mmol of N,N-bis(trimethylsilyl)aminopropyl methyltriethoxysilane (Compound 1), that the reaction terminator was changed to 2.9 mmol of methanol, and that an integrated hydrogen flow rate was adjusted. Sample B19 had a hydrogenation rate of 70%.

[0446] Analysis results of Sample B19 are shown in Table 1-4.

[0447] It was found, as a result of measurement, that a structure of a conjugated diene-based polymer obtained before adding the coupling agent in Sample B19 had a linear polymer structure, and did not have a star polymer.

(Comparative Example 9) Hydrogenated Conjugated Diene-Based Polymer (Sample B23

[0448] A hydrogenated conjugated diene-based polymer (Sample B23) was obtained through the same procedures as those of Comparative Example 1 except that the amount of initial butadiene was changed to 3,000 g, that the amount of styrene was changed to 0 g, that the polar material was changed to 4.3 mmol of 2,2-bis(2-oxolanyl)propane (BOP), that the polymerization initiator was changed to 21 mmol of n-butyllithium, that the coupling agent was changed to 6.9 mmol of N,N-bis(trimethylsilyl)aminopropyl methyltriethoxysilane (Compound 1), that the reaction terminator was changed to 3.2 mmol of methanol, and that an integrated hydrogen flow rate was adjusted. Sample B23 had a hydrogenation rate of 60%.

[0449] Analysis results of Sample B23 are shown in Table 1-5.

[0450] It was found, as a result of measurement, that a structure of a conjugated diene-based polymer obtained before adding the coupling agent in Sample B23 had a linear polymer structure, and did not have a star polymer.

(Examples 15, 16 and 17) Hydrogenated Conjugated Diene-Based Polymers (Samples B24, B25, and B26, Respectively

[0451] Hydrogenated conjugated diene-based polymers (Sample B24, Sample B25, and Sample B26) were obtained through the same procedures as those of Comparative Example 1 except that the amount of initial butadiene was changed to 3,000 g, that the amount of styrene was changed to 0 g, that the polar material was changed to 6.8 mmol of 2,2-bis(2-oxolanyl)propane (BOP), that the polymerization initiator was changed to 45 mmol of n-butyllithium, that the coupling agent was changed to 4.5 mmol of N,N,N′,N′-tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (Compound 5), that the reaction terminator was changed to 6.9 mmol of methanol, and that an integrated hydrogen flow rate was adjusted. Sample B24, Sample B25, and Sample B26 had hydrogenation rates of 60%, 75%, and 94%, respectively.

[0452] Analysis results of Sample B24, Sample B25, and Sample B26 are shown in Table 1-5.

[0453] It was found, as a result of measurement, that a structure of a conjugated diene-based polymer obtained before adding the coupling agent in each of Samples B24, B25 and B26 had a linear polymer structure, and did not have a star polymer.

(Example 31) Hydrogenated Conjugated Diene-Based Polymer (Sample B27

[0454] A hydrogenated conjugated diene-based polymer (Sample B27) was obtained through the same procedures as those of Comparative Example 3 except that the amount of initial butadiene was changed to 1,887 g, that the amount of styrene was changed to 780 g, that the amount of additional butadiene was changed to 333 g, that the polar material was changed to 72 mmol of 2,2-bis(2-oxolanyl)propane (BOP), that the polymerization initiator was changed to 98 mmol of n-butyllithium, that the branching agent was changed to 22.6 mmol of trimethoxy(4-vinylphenyl)silane (BS-1), that the coupling agent was changed to 4.9 mmol of 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane (Compound 2), that the reaction terminator was changed to 3.7 mmol of methanol, and that an integrated hydrogen flow rate was adjusted. Sample B27 had a hydrogenation rate of 71%.

[0455] Analysis results of Sample B27 are shown in Table 1-5.

[0456] As a result of measurement, a structure of a conjugated diene-based polymer obtained before adding the coupling agent in Sample B27 had a star polymer structure having 3.9 branches on average, and a conjugated diene-based polymer obtained after adding the coupling agent had, in a branched chain of 3 star structures on average, a portion derived from a vinyl-based monomer containing an alkoxysilyl group.

TABLE-US-00001 TABLE 1-1 Comparative Comparative Comparative Comparative Example 1 Example 2 Example 3 Example 1 Example 2 Example 4 (Hydrogenated) Conjugated Type B1 B2 B3 B4 B5 B6 Diene-based Polymer Initial Butadiene g 2220 1887 1887 1887 1887 1887 Additional Butadiene g 0 333 333 333 333 333 Styrene g 780 780 780 780 780 780 Cyclohexane g 21000 21000 21000 21000 21000 21000 n-Butyllithium mmol 18 92 92 92 92 92 BOP mmol 15 69 69 69 69 69 Branching Type — BS-1 BS-1 BS-1 BS-1 BS-1 Agent Amount mmol 0 18 18 18 18 18 Added Coupling Type Compound 1 Compound 2 Compound 2 Compound 2 Compound 2 Compound 2 Agent Amount mmol 6.0 8.0 8.0 8.0 8.0 8.0 Added Methanol mmol 3.0 5.7 5.7 5.7 5.7 5.7 Hydrogenation Type T — T T T T Catalyst Amount ppm 60 0 60 60 60 60 Added Conjugated Mooney 56 60 55 52 65 66 Diene-based Viscosity Polymer or Weight Ten 32 56 56 56 56 56 Hydrogenated Average thousand Conjugated Molecular Diene-based Weight Polymer Component mass % 41.7 26.1 26.1 26.1 26.1 26.5 LM Content Modification mass % 80 82 82 81 81 81 Ratio Branch 1.1 5.7 5.5 5.3 5.1 5.1 Number Bn Absolute Ten 52 106 102 100 98 98 Molecular thousand Weight Styrene mass % 25.6 26.0 25.9 25.6 25.3 25.3 Content Hydrogenation Rate % 60.0 0.0 20.0 63.0 92.0 99.5 Expression (S) 55.8 55.0 55.2 55.8 55.1 54.9 Expression (T) 92 0 34 92 99.8 99.8 Cold Flow Index 100 92 93 82 68 67 Property Δ ◯ ◯ ⊚ ⊚⊚ ⊚⊚ Comparative Example 5 Example 4 Example 5 Example 31 (Hydrogenated) Conjugated Type B8 B9 B10 B27 Diene-based Polymer Initial Butadiene g 2220 1887 1887 1887 Additional Butadiene g 0 333 333 333 Styrene g 780 780 780 780 Cyclohexane g 21000 21000 21000 21000 n-Butyllithium mmol 24 92 92 98 BOP mmol 19 69 69 72 Branching Type — BS-1 BS-1 BS-1 Agent Amount mmol 0 18 25.4 22.6 Added Coupling Type Compound 2 Compound 2 + Compound 4 Compound 2 Agent Compound 3 Amount mmol 4.3 4.0 + 4.0 9.8 4.9 Added Methanol mmol 5.3 5.7 5.3 3.7 Hydrogenation Type T T T T Catalyst Amount ppm 60 60 60 60 Added Conjugated Mooney 64 55 56 67 Diene-based Viscosity Polymer or Weight Ten 36 51 47 64 Hydrogenated Average thousand Conjugated Molecular Diene-based Weight Polymer Component mass % 34.7 29 34.1 23.6 LM Content Modification mass % 71 40 60 85 Ratio Branch 1.3 5.4 4.9 6.6 Number Bn Absolute Ten 68 87 79 116 Molecular thousand Weight Styrene mass % 25.2 25.9 25.9 25.1 Content Hydrogenation Rate % 96.0 65.0 65.0 71.0 Expression (S) 55.1 55.2 55.2 54.7 Expression (T) 99.9 0 0 94 Cold Flow Index 94 80 87 76 Property ◯ ⊚ ⊚ ⊚⊚

TABLE-US-00002 TABLE 1-2 Comparative Example 6 Example 6 Example 7 Example 8 (Hydrogenated) Conjugated Diene- Type B11 B12 B13 B14 based Polymer Initial Butadiene g 2700 2295 2295 2295 Additional Butadiene g 0 405 405 405 Styrene g 300 300 300 300 Cyclohexane g 21000 21000 21000 21000 n-Butyllithium mmol 22 110 110 110 BOP mmol 4.8 21 21 21 Branching Type — BS-2 BS-2 BS-2 Agent Amount Added mmol 0 35 35 35 Coupling Type Compound 1 Compound 5 Compound 5 Compound 5 Agent Amount Added mmol 7.3 5.9 5.9 5.9 Methanol mmol 3.3 8.6 8.6 8.6 Hydrogenation Type T T T T Catalyst Amount Added ppm 60 60 60 60 Conjugated Mooney Viscosity 53 51 73 79 Diene-based Weight Average Ten 32 66 66 66 Polymer or Molecular Weight thousand Hydrogenated Component LM mass % 36.8 25.4 25.4 25.4 Conjugated Content Diene-based Modification Ratio mass % 80 78 78 78 Polymer Branch Number Bn 1.1 9.9 9.7 9.6 Absolute Molecular Ten 53 120 117 115 Weight thousand Styrene Content mass % 9.8 9.8 9.7 9.7 Hydrogenation Rate % 60.0 60.0 88.0 93.0 Expression (S) 40.8 40.8 40.4 40.1 Expression (T) 97 97 99.1 99.7 Cold Flow Index 100 78 68 65 Property Δ ⊚⊚ ⊚⊚ ⊚⊚

TABLE-US-00003 TABLE 1-3 Comparative Example 7 Example 9 Example 10 Example 11 (Hydrogenated) Conjugated Diene- Type B15 B16 B17 B18 based Polymer Initial Butadiene g 1950 1950 1950 1950 Additional Butadiene g 0 390 390 390 Styrene g 1050 1050 1050 1050 Cyclohexane g 21000 21000 21000 21000 n-Butyllithium mmol 19 146 146 146 BOP mmol 2.1 12 12 12 Branching Type — BS-1 BS-1 BS-1 Agent Amount Added mmol 0 30 30 30 Coupling Type Compound 1 Compound 5 Compound 5 Compound 5 Agent Amount Added mmol 6.3 7.2 7.2 7.2 Methanol mmol 2.9 0 0 0 Hydrogenation Type T T T T Catalyst Amount Added ppm 60 60 60 60 Conjugated Mooney Viscosity 64 37 67 91 Diene-based Weight Average Ten 33 82 82 82 Polymer or Molecular Weight thousand Hydrogenated Component LM mass % 31.5 22.8 22.8 22.8 Conjugated Content Diene-based Modification Ratio mass % 80 83 83 38 Polymer Branch Number Bn 1.1 16.4 16.1 15.9 Absolute Molecular Ten 55 138 136 132 Weight thousand Styrene Content mass % 34.5 34.7 34.5 34.2 Hydrogenation Rate % 50.0 39.0 64.0 95.0 Expression (S) 26.4 26.6 26.4 26.0 Expression (T) 26.5 93 98 99.6 Cold Flow Index 100 90 77 60 Property Δ ◯ ⊚⊚ ⊚⊚

TABLE-US-00004 TABLE 1-4 Comparative Example 8 (Hydrogenated) Conjugated Diene- Type B19 based Polymer Initial Butadiene g 2220 Additional Butadiene g — Styrene g 780 Cyclohexane g 21000 n-Butyllithium mmol 19 BOP mmol 5.5 Branching Type — Agent Amount Added mmol 0 Coupling Type Compound 1 Agent Amount Added mmol 6.3 Methanol mmol 2.9 Hydrogenation Type T Catalyst Amount Added ppm 60 Conjugated Mooney Viscosity 55 Diene-based Weight Average Ten 31 Polymer or Molecular Weight thousand Hydrogenated Component LM mass % 31.1 Conjugated Content Diene-based Modification Ratio mass % 80 Polymer Branch Number Bn 1.1 Absolute Molecular Ten 53 Weight thousand Styrene Content mass % 25.4 Hydrogenation Rate % 70.0 Expression (S) 45.6 Expression (T) 97 Cold Flow Property Index 100 Δ

TABLE-US-00005 TABLE 1-5 Comparative Example 9 Example 15 Example 16 Example 17 (Hydrogenated) Conjugated Diene- Type B23 B24 B25 B26 based Polymer Initial Butadiene g 3000 3000 3000 3000 Additional Butadiene g — — — — Styrene g 0 0 0 0 Cyclohexane g 21000 21000 21000 21000 n-Butyllithium mmol 21 45 45 45 BOP mmol 4.3 6.8 6.8 6.8 Branching Type — — — — Agent Amount Added mmol 0 0 0 0 Coupling Type Compound 1 Compound 5 Compound 5 Compound 5 Agent Amount Added mmol 6.9 4.5 4.5 4.5 Methanol mmol 3.2 6.9 6.9 6.9 Hydrogenation Type T T T T Catalyst Amount Added ppm 60 60 60 60 Conjugated Mooney Viscosity 63 60 74 96 Diene-based Weight Average Ten 33 59 59 59 Polymer or Molecular Weight thousand Hydrogenated Component LM mass % 29.1 27.9 27.9 27.9 Conjugated Content Diene-based Modification Ratio mass % 80 81 81 81 Polymer Branch Number Bn 1.1 5.9 5.6 5.5 Absolute Molecular Ten 56 103 101 100 Weight thousand Styrene Content mass % 0 0 0 0 Hydrogenation Rate % 60.0 60.0 75.0 94.0 Expression (S) 40.7 40.7 40.4 40.2 Expression (T) 94 94 98 99 Cold Flow Index 100 90 82 75 Property Δ ◯ ⊚ ⊚⊚

[0457] Branching agents and coupling agents shown in Tables 1-1 to 1-5 are the following compounds.

[0458] [Branching Agent]

[0459] BS-1: trimethoxy(4-vinylphenyl)silane

[0460] BS-2: dimethoxymethyl(4-vinylphenyl)silane

[0461] [Coupling Agent]

[0462] Compound 1: N,N-bis(trimethylsilyl)aminopropyl methyltriethoxysilane

[0463] Compound 2: 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane

[0464] Compound 3: silicon tetrachloride

[0465] Compound 4: 1,3-dimethyl-2-imidazolidinone

[0466] Compound 5: N,N,N′,N′-tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine

Application Examples 1 to 2, 4 to 11, and 15 to 17, and Application Comparative Examples 1 to 9, and Application Example 33

[0467] Samples B1 to B6, B8 to B19, B23 to B26, and B27 shown in Tables 1-1 to 1-5 were used as raw material rubber components to obtain rubber compositions containing the respective raw material rubber components in accordance with the following compounding conditions C.

[0468] (Rubber Component) [0469] Conjugated diene-based polymer or hydrogenated conjugated diene-based polymer (each of Samples B1 to B6, B8 to B19, B23 to B26, and B27): 100 parts by mass

[0470] (Compounding Conditions C)

[0471] An amount of each agent to be compounded is expressed in parts by mass based on 100 parts by mass of a rubber component not containing a rubber softener. [0472] Silica 1 (trade name “Ultrasil 7000GR” manufactured by Evonik Degussa, nitrogen adsorption specific surface area: 170 m.sup.2/g): 50.0 parts by mass [0473] Silica 2 (trade name “Zeosil Premium 200MP” manufactured by Rhodia, nitrogen adsorption specific surface area: 220 m.sup.2/g): 25.0 parts by mass [0474] Carbon black (trade name “Seast KH (N339)”, manufactured by Tokai Carbon Co., Ltd.): 5.0 parts by mass [0475] Silane coupling agent: (trade name “Si75”, manufactured by Evonik Degussa, bis(triethoxysilylpropyl)disulfide): 6.0 parts by mass [0476] SRAE oil (trade name “Process NC140”, manufactured by JX Nippon Oil & Energy Corporation): 25.0 parts by mass [0477] Zinc oxide: 2.5 parts by mass [0478] Stearic acid: 1.0 part by mass [0479] Anti-aging agent (N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine): 2.0 parts by mass [0480] Sulfur: 2.2 parts by mass [0481] Vulcanization accelerator 1 (N-cyclohexyl-2-benzothiazylsulfinamide): 1.7 parts by mass [0482] Vulcanization accelerator 2 (diphenylguanidine): 2.0 parts by mass

[0483] Total: 222.4 parts by mass

[0484] (Kneading Method)

[0485] The above-described materials were kneaded by the following method to obtain a rubber composition. A closed kneader (having an internal volume of 0.3 L) equipped with a temperature controller was used to knead, as a first stage of kneading, the raw material rubber component (each of Samples B1 to B6, B8 to B19, B23 to B26, and B27), the fillers (silica 1, silica 2 and carbon black), the silane coupling agent, the SRAE oil, zinc oxide and stearic acid under conditions of a filling ratio of 65% and a rotor rotation speed of 30 to 50 rpm. Here, the temperature of the closed mixer was controlled to obtain each rubber composition (compound) at a discharging temperature of 155 to 160° C.

[0486] Next, after cooling the compound obtained as described above to room temperature, as a second stage of the kneading, the anti-aging agent was added thereto, and the resultant was kneaded again to improve dispersibility of the silica. Also in this case, the discharging temperature for the compound was adjusted to 155 to 160° C. by the temperature control of the mixer. After cooling, as a third stage of the kneading, sulfur and the vulcanization accelerators 1 and 2 were added, and the resultant was kneaded by an open roll set to 70° C. to obtain a rubber composition (a conjugated diene-based polymer composition or a hydrogenated conjugated diene-based polymer composition). Thereafter, the resultant rubber composition was molded and vulcanized at 160° C. for 20 minutes by a vulcanizing press. The rubber composition prior to the vulcanization, and the rubber composition after the vulcanization were evaluated. Specifically, evaluations were performed as described below.

[0487] Results of Application Comparative Examples 1 to 4, Application Comparative Examples 6 to 9, Application Examples 1 to 2, Application Examples 4 to 11, Application Examples 15 to 17, and Application Example 33 are shown in Tables 2-1 to 2-5.

[0488] Results of Application Comparative Example 5 are shown in Table 3.

(Mooney Viscosity of Compound)

[0489] Each compound obtained after the second stage of the kneading and before the third stage of the kneading was used as a sample to measure a viscosity by using a Mooney viscometer in accordance with ISO 289 after preheating the compound at 130° C. for 1 minute, and after rotating a rotor for 4 minutes at 2 rpm.

[0490] A result of each of Application Comparative Examples 2 to 4 and Application Examples 1 to 2 and 4 to 5 was shown as an index obtained assuming that a result of Application Comparative Example 1 was 100. A result of each of Application Examples 6 to 8 was shown as an index obtained assuming that a result of Application Comparative Example 6 was 100. A result of each of Application Examples 9 to 11 was shown as an index obtained assuming that a result of Application Comparative Example 7 was 100. A result was shown as an index obtained assuming that a result of Application Comparative Example 8 was 100. A result of each of Application Examples 15 to 17 was shown as an index obtained assuming that a result of Application Comparative Example 9 was 100. A result of Application Example 33 was shown as an index obtained assuming that a result of Application Comparative Example 1 was 100. A result of Application Comparative Example 5 was shown as an index obtained assuming that a result of Application Comparative Example 10 obtained under compounding conditions D described below was 100. A lower index indicates better processability.

[0491] A sample having an index of 79 or less was evaluated as very good (shown as ⊚⊚ in the tables), a sample having an index of 80 to 89 was evaluated as good (shown as ⊚ in the tables), a sample having an index of 90 to 99 was evaluated to have no practical problem (shown as ◯ in the tables), a sample having an index of 100 to 105 was evaluated as rather poor (shown as Δ in the tables), and a sample having an index of 105 or more was evaluated to have a practical problem (shown as X in the tables).

[0492] (Breaking Strength and Elongation at Break, and Fracture Performance)

[0493] Breaking strength and elongation at break were measured in accordance with a tensile test method according to JIS K6251. In addition, a product of measured values of breaking strength and elongation at break was defined as fracture performance.

[0494] A result of each of Application Comparative Examples 2 to 4 and Application Examples 1 to 2 and 4 to 5 was shown as an index obtained assuming that a result of Application Comparative Example 1 was 100. A result of each of Application Examples 6 to 8 was shown as an index obtained assuming that a result of Application Comparative Example 6 was 100. A result of each of Application Examples 9 to 11 was shown as an index obtained assuming that a result of Application Comparative Example 7 was 100. A result was shown as an index obtained assuming that a result of Application Comparative Example 8 was 100. A result of each of Application Examples 15 to 17 was shown as an index obtained assuming that a result of Application Comparative Example 9 was 100. A result of Application Example 33 was shown as an index obtained assuming that a result of Application Comparative Example 1 was 100. A result of Application Comparative Example 5 was shown as an index obtained assuming that a result of Application Comparative Example 10 obtained under compounding conditions D described below was 100. A higher index indicates that breaking strength, elongation at break (fracture strength), and fracture performance are better.

[0495] A sample having an index of 121 or more was evaluated as very good (shown as ⊚⊚ in the tables), a sample having an index of 111 to 120 was evaluated as good (shown as ⊚ in the tables), a sample having an index of 101 to 110 was evaluated to have no practical problem (shown as ◯ in the tables), a sample having an index of 95 to 100 was evaluated as rather poor (shown as Δ in the tables), and a sample having an index of 94 or less was evaluated to have a practical problem (shown as X in the tables).

[0496] (Low Fuel Consumption Performance)

[0497] A viscoelasticity testing machine “ARES” manufactured by Rheometric Scientific, Inc. was used to measure a viscoelasticity parameter in a torsion mode.

[0498] A tan δ measured at 50° C. at a frequency of 10 Hz and strain of 3% was used as an index of fuel efficiency.

[0499] A result of each of Application Comparative Examples 2 to 4 and Application Examples 1 to 2 and 4 to 5 was shown as an index obtained assuming that a result of Application Comparative Example 1 was 100. A result of each of Application Examples 6 to 8 was shown as an index obtained assuming that a result of Application Comparative Example 6 was 100. A result of each of Application Examples 9 to 11 was shown as an index obtained assuming that a result of Application Comparative Example 7 was 100. A result was shown as an index obtained assuming that a result of Application Comparative Example 8 was 100. A result of each of Application Examples 15 to 17 was shown as an index obtained assuming that a result of Application Comparative Example 9 was 100. A result of Application Example 33 was shown as an index obtained assuming that a result of Application Comparative Example 1 was 100.

[0500] A sample having an index of 121 or more was evaluated as very good (shown as ⊚⊚ in the tables), a sample having an index of 111 to 120 was evaluated as good (shown as ⊚ in the tables), a sample having an index of 101 to 110 was evaluated to have no practical problem (shown as ◯ in the tables), a sample having an index of 95 to 100 was evaluated as rather poor (shown as Δ in the tables), and a sample having an index of 94 or less may be deteriorated in fuel efficiency as compared with a standard product, and may be lowered in grade of labelling system (shown as X in the tables). Results are shown in Tables 2-1 to 2-5, and Table 3.

Application Comparative Example 10

[0501] Sample B8 shown in Table 1-1 was used as a raw material rubber component to obtain a rubber composition containing the raw material rubber component under the following compounding conditions D:

[0502] (Rubber Component) [0503] Conjugated diene-based polymer or hydrogenated conjugated diene-based polymer (Sample B8): 100 parts by mass

[0504] (Compounding Conditions D)

[0505] An amount of each agent to be compounded is expressed in parts by mass based on 100 parts by mass of a rubber component not containing a rubber softener. [0506] Silica 1 (trade name “Ultrasil 7000GR” manufactured by Evonik Degussa, nitrogen adsorption specific surface area: 170 m.sup.2/g): 50.0 parts by mass [0507] Silica 2 (trade name “Zeosil Premium 200MP” manufactured by Rhodia, nitrogen adsorption specific surface area: 220 m.sup.2/g): 25.0 parts by mass [0508] Carbon black (trade name “Seast KH (N339)”, manufactured by Tokai Carbon Co., Ltd.): 5.0 parts by mass [0509] Silane coupling agent: (trade name “Si75”, manufactured by Evonik Degussa, bis(triethoxysilylpropyl)disulfide): 6.0 parts by mass [0510] SRAE oil (trade name “Process NC140”, manufactured by JX Nippon Oil & Energy Corporation): 15.0 parts by mass [0511] Zinc oxide: 2.5 parts by mass [0512] Stearic acid: 1.0 part by mass [0513] Anti-aging agent (N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine): 2.0 parts by mass [0514] Sulfur: 2.2 parts by mass [0515] Vulcanization accelerator 1 (N-cyclohexyl benzothiazylsulfinamide): 1.7 parts by mass [0516] Vulcanization accelerator 2 (diphenylguanidine): 2.0 parts by mass

[0517] Total: 212.4 parts by mass

[0518] (Kneading Method)

[0519] The above-described materials were kneaded by the following method to obtain a rubber composition. A closed kneader (having an internal volume of 0.3 L) equipped with a temperature controller was used to knead, as a first stage of kneading, the raw material rubber component (Sample B8), the fillers (silica 1, silica 2 and carbon black), the silane coupling agent, the SRAE oil, zinc oxide and stearic acid under conditions of a filling ratio of 65% and a rotor rotation speed of 30 to 50 rpm. Here, the temperature of the closed mixer was controlled to obtain each rubber composition (compound) at a discharging temperature of 155 to 160° C.

[0520] Next, after cooling the compound obtained as described above to room temperature, as a second stage of the kneading, the anti-aging agent was added thereto, and the resultant was kneaded again to improve dispersibility of the silica. Also in this case, the discharging temperature for the compound was adjusted to 155 to 160° C. by the temperature control of the mixer. After cooling, as a third stage of the kneading, sulfur and the vulcanization accelerators 1 and 2 were added, and the resultant was kneaded by an open roll set to 70° C. to obtain a rubber composition. Thereafter, the resultant rubber composition was molded and vulcanized at 160° C. for 20 minutes by a vulcanizing press. The rubber composition prior to the vulcanization, and the rubber composition after the vulcanization were evaluated. Specifically, evaluations were performed as described below. Results are shown in Table 3.

(Mooney Viscosity of Compound)

[0521] Each compound obtained after the second stage of the kneading and before the third stage of the kneading was used as a sample to measure a viscosity by using a Mooney viscometer in accordance with ISO 289 after preheating the compound at 130° C. for 1 minute, and after rotating a rotor for 4 minutes at 2 rpm.

[0522] A result was shown as an index obtained assuming that a result of Application Comparative Example 10 obtained under the compounding conditions D was 100. A lower index indicates better processability.

[0523] A sample having an index of 79 or less was evaluated as very good (shown as ⊚⊚ in the tables), a sample having an index of 80 to 89 was evaluated as good (shown as ⊚ in the tables), a sample having an index of 90 to 99 was evaluated to have no practical problem (shown as ◯ in the tables), a sample having an index of 100 to 105 was evaluated as rather poor (shown as A in the tables), and a sample having an index of 105 or more was evaluated to have a practical problem (shown as X in the tables).

[0524] (Breaking Strength and Elongation at Break, and Fracture Performance)

[0525] Breaking strength and elongation at break were measured in accordance with a tensile test method according to JIS K6251. In addition, a product of measured values of breaking strength and elongation at break was defined as fracture performance.

[0526] A result was shown as an index obtained assuming that a result of Application Comparative Example 10 obtained under the compounding conditions D was 100. A higher index indicates that breaking strength, elongation at break (fracture strength), and fracture performance are better.

[0527] A sample having an index of 121 or more was evaluated as very good (shown as ⊚⊚ in the tables), a sample having an index of 111 to 120 was evaluated as good (shown as ⊚ in the tables), a sample having an index of 101 to 110 was evaluated to have no practical problem (shown as ◯ in the tables), a sample having an index of 95 to 100 was evaluated as rather poor (shown as Δ in the tables), and a sample having an index of 94 or less was evaluated to have a practical problem (shown as X in the tables).

TABLE-US-00006 TABLE 2-1 Application Application Application Comparative Comparative Comparative Application Application Example 1 Example 2 Example 3 Example 1 Example 2 (Hydrogenated) Conjugated Type B1 B2 B3 B4 B5 Diene-based Polymer Compounding Conditions — C C C C C Physical Mooney Viscosity Index 100 90 88  94  99 Properties of of Compound Δ ◯ ⊚ ◯ ◯ Composition Breaking Index 100 90 95 113 120 Strength Δ X Δ ⊚ ⊚ Elongation at Index 100 92 95 115 123 Break Δ X Δ ⊚ ⊚⊚ Fracture Index 100 83 90 130 148 Performance Δ X X ⊚⊚ ⊚⊚ Low Fuel Index 100 86 93 109  85 Consumption Δ X X ◯ X Performance Application Comparative Application Application Application Example 4 Example 4 Example 5 Example 33 (Hydrogenated) Conjugated Type B6 B9 B10 B27 Diene-based Polymer Compounding Conditions — C C C C Physical Mooney Viscosity Index 103   83  90  89 Properties of of Compound Δ ⊚ ◯ ⊚ Composition Breaking Index 20 106 110 107 Strength X ◯ ◯ ◯ Elongation at Index 115  107 115 109 Break ⊚ ◯ ⊚ ◯ Fracture Index 23 113 127 117 Performance X ⊚ ⊚⊚ ⊚ Low Fuel Index 65  97 102 114 Consumption X Δ ◯ ⊚ Performance

TABLE-US-00007 TABLE 2-2 Application Comparative Application Application Application Example 6 Example 6 Example 7 Example 8 (Hydrogenated) Conjugated Type B11 B12 B13 B14 Diene-based Polymer Compounding Conditions — C C C C Physical Mooney Viscosity of Index 100  87  92  95 Properties of Compound Δ ⊚ ◯ ◯ Composition Breaking Index 100 106 119 124 Strength Δ ◯ ⊚ ⊚⊚ Elongation at Index 100 107 116 119 Break Δ ◯ ⊚ ⊚ Fracture Index 100 113 138 148 Performance Δ ⊚ ⊚⊚ ⊚⊚ Low Fuel Index 100 110  99  90 Consumption Δ ◯ Δ X Performance

TABLE-US-00008 TABLE 2-3 Application Comparative Application Application Application Example 7 Example 9 Example 10 Example 11 (Hydrogenated) Conjugated Type B15 B16 B17 B18 Diene-based Polymer Compounding Conditions — C C C C Physical Mooney Viscosity of Index 100  84  86 102 Properties of Compound Δ ⊚ ⊚ Δ Composition Breaking Index 100 105 116 131 Strength Δ ◯ ⊚ ⊚⊚ Elongation at Index 100 106 120 135 Break Δ ◯ ⊚ ⊚⊚ Fracture Index 100 111 139 177 Performance Δ ⊚ ⊚⊚ ⊚⊚ Low Fuel Index 100 106 122  95 Consumption Δ ◯ ⊚⊚ Δ Performance

TABLE-US-00009 TABLE 2-4 Application Comparative Example 8 (Hydrogenated) Conjugated Type B19 Diene-based Polymer Compounding Conditions — C Physical Mooney Viscosity of Index 100 Properties of Compound Δ Composition Breaking Strength Index 100 Δ Elongation at Break Index 100 Δ Fracture Performance Index 100 Δ Low Fuel Consumption Index 100 Performance Δ

TABLE-US-00010 TABLE 2-5 Application Comparative Application Application Application Example 9 Example 15 Example 16 Example 17 (Hydrogenated) Conjugated Type B23 B24 B25 B26 Diene-based Polymer Compounding Conditions — C C C C Physical Mooney Viscosity of Index 100  83  93 100 Properties of Compound Δ ⊚ ◯ Δ Composition Breaking Index 100 102 106 110 Strength Δ ◯ ◯ ◯ Elongation at Index 100 103 105 109 Break Δ ◯ ◯ ◯ Fracture Index 100 105 111 120 Performance Δ ◯ ⊚ ⊚ Low Fuel Index 100 111 107  94 Consumption Δ ⊚ ◯ X Performance

TABLE-US-00011 TABLE 3 Application Application Comparative Comparative Example 5 Example 10 (Hydrogenated) Conjugated Type B8 B8 Diene-based Polymer Compounding Conditions — C D Physical Mooney Viscosity of Index 88 100 Properties of Compound ⊚ Δ Composition Breaking Strength Index 92 100 X Δ Elongation at Break Index 104  100 ◯ Δ Fracture Performance Index 94 100 X Δ

[0528] [Production of Hydrogenated Conjugated Diene-Based Polymer Composition (Oil-Extended Polymer)]

(Comparative Example 10) Hydrogenated Conjugated Diene-Based Polymer Composition (Sample C1

[0529] Two tank pressure vessels, each of which is a stirrer-equipped tank reactor having an internal volume of 10 L and a ratio (L/D) of internal height (L) and diameter (D) of 4.0, having an inlet at a bottom and an outlet at a top, and equipped with a stirrer and a temperature controlling jacket, were connected to each other as polymerization reactors.

[0530] 1,3-Butadiene (initial butadiene), styrene and n-hexane, from which a water content had been precedently removed, were mixed under conditions of 17.7 g/min, 10.9 g/min and 175.2 g/min, respectively. In a static mixer provided in the middle of a pipe for supplying the thus obtained mixed solution to the inlet of the reactor, n-butyllithium (n-butyllithium for treatment) to be used for residual impurity inactivation was added and mixed at a rate of 0.105 mmol/min, and the resultant was continuously supplied to the bottom of the reactor. Besides, 2,2-bis(2-oxolanyl)propane (BOP) used as a polar material and n-butyllithium (n-butyllithium for polymerization initiation) used as a polymerization initiator were supplied, at rates of 0.034 mmol/min and 0.122 mmol/min, respectively, to the bottom of the first reactor, in which materials were vigorously mixed by the stirrer, for starting polymerization, and the internal temperature of the reactor was kept at 67° C.

[0531] The thus obtained polymer solution was continuously taken out from the top of the first reactor to be continuously supplied to the bottom of the second reactor for continuing the reaction at 70° C., and the resultant was further supplied to a static mixer from the top of the second reactor.

[0532] Next, to the polymer solution flowing out of an outlet of the reactor, N,N-bis(trimethylsilyl)aminopropyl methyltriethoxysilane (Compound 1) was added, as a coupling agent, continuously at a rate of 0.041 mmol/min, and the resultant was mixed by using the static mixer for performing a coupling reaction. Here, a time until the addition of the coupling agent to the polymer solution flowing out of the outlet of the reactor was 4.8 min, the temperature was 68° C., and a difference between the temperature in the polymerizing step and the temperature until the addition of the coupling agent was 2° C.

[0533] Next, to the polymer solution resulting from the coupling reaction, methanol was added as a reaction terminator at a rate of 0.019 mmol/min.

[0534] The thus obtained conjugated diene-based polymer solution was transferred to another reactor, the hydrogenation catalyst (T) prepared as described above was added thereto in an amount, in terms of Ti, of 60 ppm per 100 parts by mass of the conjugated diene-based polymer, and a hydrogenation reaction was performed at a hydrogen pressure of 0.8 MPa and an average temperature of 85° C. for 30 minutes to obtain a solution of a hydrogenated conjugated diene-based polymer. A hydrogenation rate of a butadiene-derived structural unit in the thus obtained hydrogenated conjugated diene-based polymer was 50.0%.

[0535] Next, to the resultant solution of the hydrogenated conjugated diene-based polymer, an antioxidant (BHT) was continuously added in an amount of 0.2 g per 100 g of the polymer. Simultaneously with the antioxidant, an SRAE oil (JOMO Process NC140, manufactured by JX Nippon Oil & Energy Corporation) was continuously added as a rubber softener in an amount of 25.0 g per 100 g of the polymer, and the resultant was mixed by using a static mixer. The solvent was removed by steam stripping, and thus, a hydrogenated conjugated diene-based polymer composition (Sample C1) was obtained.

[0536] Physical properties of Sample C1 are shown in Table 4-1.

[0537] It was found, as a result of measurement, that a structure of a conjugated diene-based polymer obtained before adding the coupling agent in Sample C1 had a linear polymer structure, and did not have a star polymer.

(Comparative Example 11) Conjugated Diene-Based Polymer Composition (Sample C2

[0538] Two tank pressure vessels, each of which is a stirrer-equipped tank reactor having an internal volume of 10 L and a ratio (L/D) of internal height (L) and diameter (D) of 4.0, having an inlet at a bottom and an outlet at a top, and equipped with a stirrer and a temperature controlling jacket, were connected to each other as polymerization reactors.

[0539] 1,3-Butadiene (initial butadiene), styrene and n-hexane, from which a water content had been precedently removed, were mixed under conditions of 14.2 g/min, 10.9 g/min and 175.2 g/min, respectively. In a static mixer provided in the middle of a pipe for supplying the thus obtained mixed solution to the inlet of the reactor, n-butyllithium (n-butyllithium for treatment) to be used for residual impurity inactivation was added and mixed at a rate of 0.105 mmol/min, and the resultant was continuously supplied to the bottom of the reactor. Besides, 2,2-bis(2-oxolanyl)propane (BOP) used as a polar material and n-butyllithium (n-butyllithium for polymerization initiation) used as a polymerization initiator were supplied, at rates of 0.056 mmol/min and 0.215 mmol/min, respectively, to the bottom of the first reactor, in which materials were vigorously mixed by the stirrer, for starting polymerization, and the internal temperature of the reactor was kept at 67° C.

[0540] The thus obtained polymer solution was continuously taken out from the top of the first reactor to be continuously supplied to the bottom of the second reactor for continuing the reaction at 70° C., and the resultant was further supplied to a static mixer from the top of the second reactor. When the polymerization was sufficiently stabilized, with copolymerizing 1,3-butadiene and styrene, trimethoxy(4-vinylphenyl)silane (BS-1) was added as a branching agent from the bottom of the second reactor at a rate of 0.032 mmol/min to perform a polymerization reaction and a branching reaction for obtaining a conjugated diene-based polymer having a main chain branch structure.

[0541] Next, from a middle portion of the second reactor, 1,3-butadiene (additional butadiene), from which a water content had been precedently removed, was additionally added under a condition of 3.5 g/min to further perform the polymerization reaction.

[0542] Next, to the polymer solution flowing out of an outlet of the reactor, N,N,N′,N′-tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (Compound 5) was added, as a coupling agent, continuously at a rate of 0.013 mmol/min, and the resultant was mixed by using a static mixer for performing a coupling reaction. Here, a time until the addition of the coupling agent to the polymer solution flowing out of the outlet of the reactor was 4.8 min, the temperature was 68° C., and a difference between the temperature in the polymerizing process and the temperature until the addition of the coupling agent was 2° C.

[0543] Next, to the polymer solution resulting from the coupling reaction, methanol was added as a reaction terminator at a rate of 0.018 mmol/min, and then an antioxidant (BHT) was continuously added in an amount of 0.2 g per 100 g of the polymer at a rate of 0.055 g/min (n-hexane solution). Simultaneously with the antioxidant, an SRAE oil (JOMO Process NC140, manufactured by JX Nippon Oil & Energy Corporation) was continuously added as a rubber softener in an amount of 25.0 g per 100 g of the polymer, and the resultant was mixed by using a static mixer. The solvent was removed by steam stripping, and thus, a conjugated diene-based polymer (Sample C2) was obtained.

[0544] Physical properties of Sample C2 are shown in Table 4-1.

[0545] In each of the polymer obtained before adding the branching agent, the polymer obtained after adding the branching agent, and the polymer obtained after adding the coupling agent, the structure of the conjugated diene-based polymer was identified based on comparison between a molecular weight obtained by GPC measurement and a branch number obtained by viscosity detector-equipped GPC measurement. Hereinafter, the structure of each sample was similarly identified. As a result of the measurement, a structure of a conjugated diene-based polymer obtained after adding the branching agent in Sample C2 had a star polymer structure having 4.2 branches on average, and a conjugated diene-based polymer obtained after adding the coupling agent had, in a branched chain of 4 star structures on average, a portion derived from a vinyl-based monomer containing an alkoxysilyl group.

(Comparative Example 12) Hydrogenated Conjugated Diene-Based Polymer Composition (Sample C3

[0546] Two tank pressure vessels, each of which is a stirrer-equipped tank reactor having an internal volume of 10 L and a ratio (L/D) of internal height (L) and diameter (D) of 4.0, having an inlet at a bottom and an outlet at a top, and equipped with a stirrer and a temperature controlling jacket, were connected to each other as polymerization reactors.

[0547] 1,3-Butadiene (initial butadiene), styrene and n-hexane, from which a water content had been precedently removed, were mixed under conditions of 14.2 g/min, 10.9 g/min and 175.2 g/min, respectively. In a static mixer provided in the middle of a pipe for supplying the thus obtained mixed solution to the inlet of the reactor, n-butyllithium (n-butyllithium for treatment) to be used for residual impurity inactivation was added and mixed at a rate of 0.105 mmol/min, and the resultant was continuously supplied to the bottom of the reactor. Besides, 2,2-bis(2-oxolanyl)propane (BOP) used as a polar material and n-butyllithium (n-butyllithium for polymerization initiation) used as a polymerization initiator were supplied, at rates of 0.056 mmol/min and 0.215 mmol/min, respectively, to the bottom of the first reactor, in which materials were vigorously mixed by the stirrer, for starting polymerization, and the internal temperature of the reactor was kept at 67° C.

[0548] The thus obtained polymer solution was continuously taken out from the top of the first reactor to be continuously supplied to the bottom of the second reactor for continuing the reaction at 70° C., and the resultant was further supplied to a static mixer from the top of the second reactor. When the polymerization was sufficiently stabilized, with copolymerizing 1,3-butadiene and styrene, trimethoxy(4-vinylphenyl)silane (BS-1) was added as a branching agent from the bottom of the second reactor at a rate of 0.032 mmol/min to perform a polymerization reaction and a branching reaction for obtaining a conjugated diene-based polymer having a main chain branch structure.

[0549] Next, from a middle portion of the second reaction, 1,3-butadiene (additional butadiene), from which a water content had been precedently removed, was additionally added under a condition of 3.5 g/min to further perform the polymerization reaction.

[0550] Next, to the polymer solution flowing out of an outlet of the reactor, N,N,N′,N′-tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (Compound 5) was added, as a coupling agent, continuously at a rate of 0.013 mmol/min, and the resultant was mixed by using a static mixer for performing a coupling reaction. Here, a time until the addition of the coupling agent to the polymer solution flowing out of the outlet of the reactor was 4.8 min, the temperature was 68° C., and a difference between the temperature in the polymerizing process and the temperature until the addition of the coupling agent was 2° C.

[0551] Next, to the polymer solution resulting from the coupling reaction, methanol was added as a reaction terminator at a rate of 0.018 mmol/min to obtain a solution of a conjugated diene-based polymer.

[0552] The thus obtained solution of the conjugated diene-based polymer was transferred to another reactor, the hydrogenation catalyst (T) prepared as described above was added thereto in an amount, in terms of Ti, of 60 ppm per 100 parts by mass of the conjugated diene-based polymer, and a hydrogenation reaction was performed at a hydrogen pressure of 0.8 MPa and an average temperature of 85° C. for 20 minutes to obtain a solution of a hydrogenated conjugated diene-based polymer. A hydrogenation rate of a butadiene-derived structural unit in the thus obtained hydrogenated conjugated diene-based polymer was 20.0%.

[0553] Next, to the resultant solution of the hydrogenated conjugated diene-based polymer, an antioxidant (BHT) was continuously added in an amount of 0.2 g per 100 g of the polymer. Simultaneously with the antioxidant, an SRAE oil (JOMO Process NC140, manufactured by JX Nippon Oil & Energy Corporation) was continuously added as a rubber softener in an amount of 25.0 g per 100 g of the polymer, and the resultant was mixed by using a static mixer. The solvent was removed by steam stripping, and thus, a hydrogenated conjugated diene-based polymer composition (Sample C3) was obtained.

[0554] Physical properties of Sample C3 are shown in Table 4-1.

[0555] As a result of measurement, a structure of a conjugated diene-based polymer obtained after adding the branching agent in Sample C3 had a star polymer structure having 4.2 branches on average, and a conjugated diene-based polymer obtained after adding the coupling agent had, in a branched chain of 4 star structures on average, a portion derived from a vinyl-based monomer containing an alkoxysilyl group.

(Examples 18 to 20) Hydrogenated Conjugated Diene-Based Polymer Compositions (Samples C4, C5 and C6, Respectively

[0556] Hydrogenated conjugated diene-based polymer compositions (Sample C4, Sample C5, and Sample C6) were obtained through the same procedures as those of Comparative Example 12 except that an integrated hydrogen flow rate in the hydrogenation reaction was adjusted. Hydrogenated conjugated diene-based polymers of Sample C4, Sample C5, and Sample C6 had hydrogenation rates of 55.0%, 87.0%, and 93.0%, respectively.

[0557] Analysis results of Sample C4, Sample C5, and Sample C6 are shown in Table 4-1.

[0558] As a result of measurement, a structure of a conjugated diene-based polymer obtained after adding the branching agent in each of Samples C4, C5, and C6 had a star polymer structure having 4.2 branches on average, and a conjugated diene-based polymer obtained after adding the coupling agent had, in a branched chain of 4 star structures on average, a portion derived from a vinyl-based monomer containing an alkoxysilyl group.

(Examples 21 to 23) Hydrogenated Conjugated Diene-Based Polymer Compositions (Samples C7, C8, and C9, Respectively

[0559] Hydrogenated conjugated diene-based polymer compositions (Sample C7, Sample C8, and Sample C9) were obtained through the same procedures as those of Comparative Example 12 except that the polar material was changed to 0.056 mmol/min of 2,2-bis(2-oxolanyl)propane (BOP), that the polymerization initiator was changed to 0.163 mmol/min of n-butyllithium (n-butyllithium for polymerization initiation), that the branching agent was changed to 0.033 mmol/min of trimethoxy(4-vinylphenyl)silane (BS-1), that the coupling agent was changed to 0.011 mol/min of 3-(4-methylpiperazine-1-yl)propyltrimethoxysilane (Compound 6), that the reaction terminator was changed to 0.16 mmol/min of methanol, and that an integrated hydrogen flow rate in the hydrogenation reaction was adjusted. Hydrogenated conjugated diene-based polymers of Sample C7, Sample C8, and Sample C9 had hydrogenation rates of 50.0%, 84.0%, and 93.0%, respectively.

[0560] Analysis results of Sample C7, Sample C8, and Sample C9 are shown in Table 4-1.

[0561] As a result of measurement, a structure of a conjugated diene-based polymer obtained after adding the branching agent in each of Samples C7, C8, and C9 had a star polymer structure having 4.2 branches on average, and a conjugated diene-based polymer obtained after adding the coupling agent had, in a branched chain of 1 star structure on average, a portion derived from a vinyl-based monomer containing an alkoxysilyl group.

(Comparative Example 13) Hydrogenated Conjugated Diene-Based Polymer Composition (Sample C10

[0562] A hydrogenated conjugated diene-based polymer composition (Sample C10) was obtained through the same procedures as those of Comparative Example 10 except that the amount of initial butadiene was changed to 21.5 g/min, that the amount of styrene was changed to 7.2 g/min, that the polar material was changed to 0.036 mmol/min of 2,2-bis(2-oxolanyl)propane (BOP), that the polymerization initiator was changed to 0.130 mmol/min of n-butyllithium (n-butyllithium for polymerization initiation), that the coupling agent was changed to 0.044 mmol/min of N,N-bis(trimethylsilyl)aminopropyl methyltriethoxysilane (Compound 1), that the reaction terminator was changed to 0.02 mmol/min of methanol, and that an integrated hydrogen flow rate in the hydrogenation reaction was adjusted. A hydrogenated conjugated diene-based polymer of Sample C10 had a hydrogenation rate of 50.0%.

[0563] Analysis results of Sample C10 are shown in Table 4-2.

[0564] It was found, as a result of measurement, that a structure of a conjugated diene-based polymer obtained before adding the coupling agent in Sample C10 had a linear polymer structure, and did not have a star polymer.

(Examples 24 to 26) Hydrogenated Conjugated Diene-Based Polymer Compositions (Samples C11, C12, and C13, Respectively

[0565] Hydrogenated conjugated diene-based polymer compositions (Sample C11, Sample C12, and Sample C13) were obtained through the same procedures as those of Comparative Example 12 except that the amount of initial butadiene was changed to 17.2 g/min, that the amount of styrene was changed to 7.2 g/min, that the polar material was changed to 0.051 mmol/min of 2,2-bis(2-oxolanyl)propane (BOP), that the polymerization initiator was changed to 0.170 mmol/min of n-butyllithium (n-butyllithium for polymerization initiation), that the branching agent was changed to 0.041 mmol/min of dimethoxymethyl(4-vinylphenyl)silane (BS-2), that the amount of additional butadiene was changed to 4.3 g/min, that the coupling agent was changed to 0.012 mol/min of 3,3′-(piperazine-1,4-di-yl)bis(N,N-bis(3-(triethoxysilyl)propyl)propan-1-amine) (Compound 7), that the reaction terminator was changed to 0.016 mmol/min of methanol, and that an integrated hydrogen flow rate in the hydrogenation reaction was adjusted. Hydrogenated conjugated diene-based polymers of Sample C11, Sample C12, and Sample C13 had hydrogenation rates of 50.0%, 82.0%, and 95.0%, respectively.

[0566] Analysis results of Sample C11, Sample C12, and Sample C13 are shown in Table 4-2.

[0567] As a result of measurement, a structure of a conjugated diene-based polymer obtained after adding the branching agent in each of Samples C11, C12, and C13 had a star polymer structure having 3 branches on average, and a conjugated diene-based polymer obtained after adding the coupling agent had, in a branched chain of 3.8 star structures on average, a portion derived from a vinyl-based monomer containing an alkoxysilyl group.

(Comparative Example 14) Hydrogenated Conjugated Diene-Based Polymer Composition (Sample C14

[0568] A hydrogenated conjugated diene-based polymer composition (Sample C14) was obtained through the same procedures as those of Comparative Example 10 except that the amount of initial butadiene was changed to 17.2 g/min, that the amount of styrene was changed to 11.5 g/min, that the polar material was changed to 0.054 mmol/min of 2,2-bis(2-oxolanyl)propane (BOP), that the polymerization initiator was changed to 0.120 mmol/min of n-butyllithium (n-butyllithium for polymerization initiation), that the coupling agent was changed to 0.041 mmol/min of N,N-bis(trimethylsilyl)aminopropyl methyltriethoxysilane (Compound 1), that the reaction terminator was changed to 0.018 mmol/min of methanol, and that an integrated hydrogen flow rate in the hydrogenation reaction was adjusted. A hydrogenated conjugated diene-based polymer of Sample C14 had a hydrogenation rate of 60%.

[0569] Analysis results of Sample C14 are shown in Table 4-3.

[0570] It was found, as a result of measurement, that a structure of a conjugated diene-based polymer obtained before adding the coupling agent in Sample C14 had a linear polymer structure, and did not have a star polymer.

(Examples 27 to 29) Hydrogenated Conjugated Diene-Based Polymer Compositions (Samples C15, C16, and C17, Respectively

[0571] Hydrogenated conjugated diene-based polymer compositions (Sample C15, Sample C16, and Sample C17) were obtained through the same procedures as those of Comparative Example 10 except that the amount of initial butadiene was changed to 17.2 g/min, that the amount of styrene was changed to 11.5 g/min, that the polar material was changed to 0.067 mmol/min of 2,2-bis(2-oxolanyl)propane (BOP), that the polymerization initiator was changed to 0.159 mmol/min of n-butyllithium (n-butyllithium for polymerization initiation), that the coupling agent was changed to 0.017 mmol/min of N,N,N′,N′-tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (compound 5), that the reaction terminator was changed to 0.024 mmol/min of methanol, and that an integrated hydrogen flow rate in the hydrogenation reaction was adjusted. Hydrogenated conjugated diene-based polymers of Sample C15, Sample C16, and Sample C17 had hydrogenation rates of 60.0%, 82.0%, and 93.0%, respectively.

[0572] Analysis results of Sample C15, Sample C16, and Sample C17 are shown in Table 4-3.

[0573] As a result of measurement, a structure of a conjugated diene-based polymer obtained before adding the coupling agent in each of Samples C15, C16 and C17 had a linear polymer structure, and did not have a star polymer.

(Comparative Example 15) Conjugated Diene-Based Polymer Composition (Sample C18

[0574] A conjugated diene-based polymer composition (Sample C18) was obtained through the same procedures as those of Comparative Example 10 except that the amount of initial butadiene was changed to 17.9 g/min, that the amount of styrene was changed to 9.8 g/min, that the amount of cyclohexane was changed to 145.3 g/min, that the polar material was changed to 0.098 mmol/min of 2,2-bis(2-oxolanyl)propane (BOP), that the polymerization initiator was changed to 0.242 mmol/min of n-butyllithium (n-butyllithium for polymerization initiation), that the coupling agent was changed to 0.030 mmol/min of N,N,N′,N′-tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (compound 5), that the reaction terminator was changed to 0.044 mmol/min of methanol, and that the hydrogenation catalyst (T) was not added and hence a hydrogenation reaction was not performed.

[0575] Analysis results of Sample C18 are shown in Table 4-4.

[0576] It was found, as a result of measurement, that a structure of a conjugated diene-based polymer obtained before adding the coupling agent in Sample C18 had a linear polymer structure, and did not have a star polymer.

(Example 30) Hydrogenated Conjugated Diene-Based Polymer Composition (Sample C19

[0577] A hydrogenated conjugated diene-based polymer composition (Sample C19) was obtained through the same procedures as those of Comparative Example 10 except that the amount of initial butadiene was changed to 17.9 g/min, that the amount of styrene was changed to 9.8 g/min, that the amount of cyclohexane was changed to 145.3 g/min, that the polar material was changed to 0.098 mmol/min of 2,2-bis(2-oxolanyl)propane (BOP), that the polymerization initiator was changed to 0.242 mmol/min of n-butyllithium (n-butyllithium for polymerization initiation), that the coupling agent was changed to 0.030 mmol/min of N,N,N′,N′-tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (compound 5), that the reaction terminator was changed to 0.044 mmol/min of methanol, and that an integrated hydrogen flow rate in the hydrogenation reaction was adjusted. A hydrogenated conjugated diene-based polymer of Sample C19 had a hydrogenation rate of 80.0%.

[0578] Analysis results of Sample C19 are shown in Table 4-4.

[0579] It was found, as a result of measurement, that a structure of a conjugated diene-based polymer obtained before adding the coupling agent in Sample C19 had a linear polymer structure, and did not have a star polymer.

Comparative Example 16

[0580] The same procedures as those of Comparative Example 10 were performed except that the amount of initial butadiene was changed to 17.9 g/min, that the amount of styrene was changed to 9.8 g/min, that the amount of cyclohexane was changed to 145.3 g/min, that the polar material was changed to 0.018 mmol/min of 2,2-bis(2-oxolanyl)propane (BOP), that the polymerization initiator was changed to 0.121 mmol/min of n-butyllithium (n-butyllithium for polymerization initiation), that the coupling agent was changed to 0.012 mmol/min of N,N,N′,N′-tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (compound 5), that the reaction terminator was changed to 0.025 mmol/min of methanol, and that the hydrogenation catalyst (T) was added in an amount, in terms of Ti, of 100 ppm per 100 parts by mass of a conjugated diene-based polymer. Since the viscosity became very high during the hydrogenation reaction, the hydrogenation reaction did not proceed, and hence the reaction was stopped, and thus, a conjugated diene-based polymer composition (Sample C20) was obtained.

[0581] Analysis results of Sample C20 are shown in Table 4-4.

[0582] It was found, as a result of measurement, that a structure of a conjugated diene-based polymer obtained before adding the coupling agent in Sample C20 had a linear polymer structure, and did not have a star polymer.

Example 32

[0583] The same procedures as those of Comparative Example 10 were performed except that the amount of initial butadiene was changed to 17.9 g/min, that the amount of styrene was changed to 9.8 g/min, that the amount of cyclohexane was changed to 145.3 g/min, that the polar material was changed to 0.018 mmol/min of 2,2-bis(2-oxolanyl)propane (BOP), that the polymerization initiator was changed to 0.121 mmol/min of n-butyllithium (n-butyllithium for polymerization initiation), that the coupling agent was changed to 0.012 mmol/min of N,N,N′,N′-tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine (compound 5), that the reaction terminator was changed to 0.025 mmol/min of methanol, that the hydrogenation catalyst (T) was added in an amount, in terms of Ti, of 200 ppm per 100 parts by mass of a conjugated diene-based polymer, and that cyclohexane was added to obtain a copolymer concentration in cyclohexane of 12% by mass. Since the viscosity became very high during the hydrogenation reaction, the hydrogenation reaction did not proceed, and hence the reaction was stopped, and thus, a conjugated diene-based polymer composition (Sample C21) was obtained.

[0584] Analysis results of Sample C21 are shown in Table 4-4.

[0585] It was found, as a result of measurement, that a structure of a conjugated diene-based polymer obtained before adding the coupling agent in Sample C21 had a linear polymer structure, and did not have a star polymer.

Example 33

[0586] Through the same procedures as those of Comparative Example 12 except that the amount of initial butadiene was changed to 14.3 g/min, that the amount of styrene was changed to 9.8 g/min, that the polar material was changed to 0.027 mmol/min of 2,2-bis(2-oxolanyl)propane (BOP), that the polymerization initiator was changed to 0.194 mmol/min of n-butyllithium (n-butyllithium for polymerization initiation), that the branching agent was changed to 0.048 mmol/min of trimethoxy(4-vinylphenyl)silane (BS-1), that the amount of additional butadiene was changed to 4.3 g/min, that the coupling agent was changed to 0.010 mmol/min of 2,2-dimethoxy (3-trimethoxysilylpropyl)-1-aza-2-silacyclopentane (compound 2), that the reaction terminator was changed to 0.010 mmol/min of methanol, and that an integrated hydrogen flow rate in the hydrogenation reaction was adjusted, the hydrogenation reaction proceeded without problems, and thus, a hydrogenated conjugated diene-based polymer composition (Sample C22) was obtained. A hydrogenated conjugated diene-based polymer of Sample C22 had a hydrogenation rate of 50%.

[0587] Analysis results of Sample C22 are shown in Table 4-4.

[0588] As a result of measurement, a structure of a conjugated diene-based polymer obtained after adding the branching agent in Sample C22 had a star polymer structure having 3.9 branches on average, and a conjugated diene-based polymer obtained after adding the coupling agent had, in a branched chain of 3.6 star structures on average, a portion derived from a vinyl-based monomer containing an alkoxysilyl group.

TABLE-US-00012 TABLE 4-1 Comparative Comparative Comparative Example 10 Example 11 Example 12 Example 18 Example 19 (Hydrogenated) Conjugated Type C1 C2 C3 C4 C5 Diene-based Polymer Composition Initial Butadiene (g/min) 17.7 14.2 14.2 14.2 14.2 Additional Butadiene (g/min) 0 3.5 3.5 3.5 3.5 Styrene (g/min) 10.9 10.9 10.9 10.9 10.9 Cyclohexane (g/min) 175.2 175.2 175.2 175.2 175.2 n-Butyllithium for Treatment (mmol/ 0.105 0.105 0.105 0.105 0.105 min) n-Butyllithium for Polymerization Initiation (mmol/ 0.122 0.215 0.215 0.215 0.215 min) BOP (mmol/ 0.034 0.056 0.056 0.056 0.056 min) Branching Type — BS-1 BS-1 BS-1 BS-1 Agent Amount Added (mmol/ 0 0.032 0.032 0.032 0.032 min) Coupling Type Compound 1 Compound 5 Compound 5 Compound 5 Compound 5 Agent Amount Added (mmol/ 0.041 0.013 0.013 0.013 0.013 min) Methanol (mmol/ 0.019 0.018 0.018 0.018 0.018 min) Hydrogenation Type T — T T T Catalyst Hydrogenation Catalyst (ppm) 60 0 60 60 60 Type of Rubber Softener SRAE SRAE SRAE SRAE SRAE Amount of Rubber Softener Added (phm) 25 25 25 25 25 Conjugated Diene- Mooney Viscosity 90 66 63 79 104 based Polymer or Weight Average 72 115 113 112 112 Hydrogenated Molecular Weight Conjugated Diene- Component LM mass % 26.9 20.7 20.7 20.7 20.7 based Polymer Content Modification Ratio mass % 82 88 88 88 88 Branch Number Bn 1.3 26.8 26.6 26.2 26.0 Absolute Molecular Ten 103 295 291 287 276 Weight thousand Styrene Content mass % 37.6 38 37.8 37.5 37.3 Hydrogenation Rate % 50.0 0.0 20.0 55.0 87.0 Expression (S) 30.6 30 30.6 30.6 30.3 Expression (T) 95 0 56 96 100 Oil-extended Cold Flow Property Index 100 91 87 76 69 Polymer Δ ◯ ⊚ ⊚⊚ ⊚⊚ Example 20 Example 21 Example 22 Example 23 (Hydrogenated) Conjugated Type C6 C7 C8 C9 Diene-based Polymer Composition Initial Butadiene (g/min) 14.2 14.2 14.2 14.2 Additional Butadiene (g/min) 3.5 3.5 3.5 3.5 Styrene (g/min) 10.9 10.9 10.9 10.9 Cyclohexane (g/min) 175.2 175.2 175.2 175.2 n-Butyllithium for Treatment (mmol/ 0.105 0.105 0.105 0.105 min) n-Butyllithium for Polymerization Initiation (mmol/ 0.215 0.163 0.163 0.163 min) BOP (mmol/ 0.056 0.056 0.056 0.056 min) Branching Type BS-1 BS-1 BS-1 BS-1 Agent Amount Added (mmol/ 0.032 0.033 0.033 0.033 min) Coupling Type Compound 5 Compound 6 Compound 6 Compound 6 Agent Amount Added (mmol/ 0.013 0.011 0.011 0.011 min) Methanol (mmol/ 0.018 0.016 0.016 0.016 min) Hydrogenation Type T T T T Catalyst Hydrogenation Catalyst (ppm) 60 60 60 60 Type of Rubber Softener SRAE SRAE SRAE SRAE Amount of Rubber Softener Added (phm) 25 25 25 25 Conjugated Diene- Mooney Viscosity 125 87 99 112 based Polymer or Weight Average 112 92 92 92 Hydrogenated Molecular Weight Conjugated Diene- Component LM mass % 20.7 23.1 23.1 23.1 based Polymer Content Modification Ratio mass % 88 86 86 86 Branch Number Bn 25.7 3.4 3.2 3.0 Absolute Molecular Ten 274 154 150 147 Weight thousand Styrene Content mass % 37.2 37.5 37.3 37.2 Hydrogenation Rate % 93.0 50.0 84.0 93.0 Expression (S) 30.1 30.6 30.3 30.1 Expression (T) 100 97 98 99 Oil-extended Cold Flow Property Index 64 90 84 79 Polymer ⊚⊚ ◯ ⊚ ⊚⊚

TABLE-US-00013 TABLE 4-2 Comparative Example 13 Example 24 Example 25 Example 26 (Hydrogenated) Conjugated Type C10 C11 C12 C13 Diene-based Polymer Composition Initial Butadiene (g/min) 21.5 17.2 17.2 17.2 Additional Butadiene (g/min) 0 4.3 4.3 4.3 Styrene (g/min) 7.2 7.2 7.2 7.2 Cyclohexane (g/min) 175.2 175.2 175.2 175.2 n-Butyllithium for Treatment (mmol/ 0.105 0.105 0.105 0.105 min) n-Butyllithium for Polymerization (mmol/ 0.130 0.17 0.17 0.17 Initiation min) BOP (mmol/ 0.036 0.051 0.051 0.051 min) Branching Type — BS-2 BS-2 BS-2 Agent Amount Added (mmol/ 0 0.041 0.041 0.041 min) Coupling Type Compound 1 Compound 7 Compound 7 Compound 7 Agent Amount Added (mmol/ 0.044 0.012 0.012 0.012 min) Methanol (mmol/ 0.02 0.016 0.016 0.016 min) Hydrogenation Type T T T T Catalyst Hydrogenation Catalyst (ppm) 60 60 60 60 Type of Rubber Softener SRAE SRAE SRAE SRAE Amount of Rubber Softener Added (phm) 25 25 25 25 Conjugated Mooney Viscosity 89 79 90 102 Diene-based Weight Average 73 103 101 100 Polymer or Molecular Weight Hydrogenated Component LM mass % 27.2 32.1 32.1 32.1 Conjugated Content Diene-based Modification Ratio mass % 84 84 84 84 Polymer Branch Number Bn 1.3 11.4 11.1 10.9 Absolute Molecular Ten 101 202 198 195 Weight thousand Styrene Content mass % 24.6 24.6 24.7 24.4 Hydrogenation Rate % 50.0 50.0 82.0 95.0 Expression (S) 30.6 30.6 30.3 30.1 Expression (T) 98 98 99 99 Oil-extended Cold Flow Property Index 100 90 76 67 Polymer Δ ◯ ⊚⊚ ⊚⊚

TABLE-US-00014 TABLE 4-3 Comparative Example 14 Example 27 Example 28 Example 29 (Hydrogenated) Conjugated Type C14 C15 C16 C17 Diene-based Polymer Composition Initial Butadiene (g/min) 17.2 17.2 17.2 17.2 Additional Butadiene (g/min) 0 0 0 0 Styrene (g/min) 11.5 11.5 11.5 11.5 Cyclohexane (g/min) 175.2 175.2 175.2 175.2 n-Butyllithium for Treatment (mmol/ 0.105 0.105 0.105 0.105 min) n-Butyllithium for Polymerization (mmol/ 0.120 0.159 0.159 0.159 Initiation min) BOP (mmol/ 0.054 0.067 0.067 0.067 min) Branching Type — — — — Agent Amount Added (mmol/ 0 0 0 0 min) Coupling Type Compound 1 Compound 5 Compound 5 Compound 5 Agent Amount Added (mmol/ 0.041 0.017 0.017 0.017 min) Methanol (mmol/ 0.018 0.024 0.024 0.024 min) Hydrogenation Type T T T T Catalyst Hydrogenation Catalyst (ppm) 60 60 60 60 Type of Rubber Softener SRAE SRAE SRAE SRAE Amount of Rubber Softener Added (phm) 25 25 25 25 Conjugated Mooney Viscosity 90 88 100 109 Diene-based Weight Average 74 99 99 99 Polymer or Molecular Weight Hydrogenated Component LM mass % 27.0 22.7 22.7 22.7 Conjugated Content Diene-based Modification Ratio mass % 83 87 87 87 Polymer Branch Number Bn 1.3 6.0 5.8 5.5 Absolute Molecular Ten 101 144 142 140 Weight thousand Styrene Content mass % 39.5 39.5 39.3 39.2 Hydrogenation Rate % 60.0 60.0 82.0 93.0 Expression (S) 40.8 40.8 40.3 40.1 Expression (T) 96 96 98 99 Oil-extended Cold Flow Property Index 100 90 80 73 Polymer Δ ◯ ⊚ ⊚⊚

TABLE-US-00015 TABLE 4-4 Comparative Comparative Example 15 Example 30 Example 16 Example 32 Example 33 (Hydrogenated) Conjugated Type C18 C19 C20 C21 C22 Diene-based Polymer Composition Initial Butadiene (g/min) 17.9 17.9 17.9 17.9 14.3 Additional Butadiene (g/min) 0 0 0 0 3.6 Styrene (g/min) 9.8 9.8 9.8 9.8 9.8 Cyclohexane (g/min) 145.3 145.3 145.3 145.3 145.3 n-Butyllithium for Treatment (mmol/ 0.105 0.105 0.105 0.105 0.105 min) n-Butyllithium for Polymerization (mmol/ 0.242 0.242 0.121 0.121 0.194 Initiation min) BOP (mmol/ 0.098 0.098 0.018 0.018 0.027 min) Branching Type — — — — BS-1 Agent Amount Added (mmol/ 0 0 0 0 0.048 min) Coupling Type Compound 5 Compound 5 Compound 5 Compound 5 Compound 2 Agent Amount Added (mmol/ 0.030 0.030 0.012 0.012 0.010 min) Methanol (mmol/ 0.044 0.044 0.025 0.025 0.010 min) Hydrogenation Type — T T T T Catalyst Hydrogenation (ppm) 0 60 100 200 100 Catalyst Type of Rubber Softener SRAE SRAE SRAE SRAE SRAE Amount of Rubber Softener Added (phm) 25 25 25 25 25 Conjugated Mooney Viscosity 65 100 129 134 118 Diene-based Weight Average 86 86 127 127 121 Polymer or Molecular Weight Hydrogenated Component LM mass % 23.0 23.0 16.3 16.3 20.1 Conjugated Content Diene-based Modification Ratio mass % 80 80 76 76 78 Polymer Branch Number 5.9 5.5 5.7 5.6 6.4 Bn Absolute Ten 123 120 194 194 293 Molecular Weight thousand Styrene Content mass % 35 34.7 34.6 34.6 34.6 Hydrogenation % 0.0 80.0 20.0 34.0 50.0 Rate Expression (S) 42 42.2 21.1 21.1 23.0 Expression (T) 0 99 91 97 98 Oil-extended Cold Flow Index 100 75 100 98 89 Polymer Property Δ ⊚⊚ Δ ◯ ⊚

[0589] Branching agents and coupling agents shown in Tables 4-1 to 4-4 are the following compounds.

[0590] [Branching Agent]

[0591] BS-1: trimethoxy(4-vinylphenyl)silane

[0592] BS-2: dimethoxymethyl(4-vinylphenyl)silane

[0593] [Coupling Agent]

[0594] Compound 1: N,N-bis(trimethylsilyl)aminopropyl methyltriethoxysilane

[0595] Compound 5: N,N,N′,N′-tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine

[0596] Compound 6: 3-(4-methylpiperazine-1-yl)propyltriethoxysilane

[0597] Compound 7: 3,3′-(piperazine-1,4-di-yl)bis(N,N-bis(3-(triethoxysilyl)propyl)propan-1-amine)

Application Examples 19 to 31, Application Comparative Examples 11 to 16, Application Comparative Example 19, and Application Examples 34 and 35

[0598] Samples C1 to C19, and C20 to C22 shown in Tables 4-1 to 4-4 were used as raw material rubber components to obtain rubber compositions containing the respective raw material rubber components in accordance with the following compounding conditions E.

[0599] (Rubber Component) [0600] Conjugated diene-based polymer composition or hydrogenated conjugated diene-based polymer composition (each of Samples C1 to C19 and C20 to C22): 100 parts by mass (parts by mass excluding a rubber softener)

[0601] (Compounding Conditions E)

[0602] An amount of each agent to be compounded is expressed in parts by mass based on 100 parts by mass of a rubber component not containing a rubber softener. [0603] Silica 1 (trade name “Ultrasil 7000GR” manufactured by Evonik Degussa, nitrogen adsorption specific surface area: 170 m.sup.2/g): 50.0 parts by mass [0604] Silica 2 (trade name “Zeosil Premium 200MP” manufactured by Rhodia, nitrogen adsorption specific surface area: 220 m.sup.2/g): 25.0 parts by mass [0605] Carbon black (trade name “Seast KH (N339)”, manufactured by Tokai Carbon Co., Ltd.): 5.0 parts by mass [0606] Silane coupling agent: (trade name “Si75”, manufactured by Evonik Degussa, bis(triethoxysilylpropyl)disulfide): 6.0 parts by mass [0607] SRAE oil (trade name “Process NC140”, manufactured by JX Nippon Oil & Energy Corporation): 37.5 parts by mass (including an amount precedently added as a rubber softener to be contained in each of Samples C1 to C19) [0608] Zinc oxide: 2.5 parts by mass [0609] Stearic acid: 1.0 part by mass [0610] Anti-aging agent (N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine): 2.0 parts by mass [0611] Sulfur: 2.2 parts by mass [0612] Vulcanization accelerator 1 (N-cyclohexyl-2-benzothiazylsulfinamide): 1.7 parts by mass [0613] Vulcanization accelerator 2 (diphenylguanidine): 2.0 parts by mass

[0614] Total: 234.9 parts by mass

[0615] (Kneading Method)

[0616] The above-described materials were kneaded by the following method to obtain a rubber composition. A closed kneader (having an internal volume of 0.3 L) equipped with a temperature controller was used to knead, as a first stage of kneading, the raw material rubber component (each of Samples C1 to C19, and C20 to C22), the fillers (silica 1, silica 2 and carbon black), the silane coupling agent, the SRAE oil, zinc oxide and stearic acid under conditions of a filling ratio of 65% and a rotor rotation speed of 30 to 50 rpm. Here, the temperature of the closed mixer was controlled to obtain each rubber composition (compound) at a discharging temperature of 155 to 160° C.

[0617] Next, after cooling the compound obtained as described above to room temperature, as a second stage of the kneading, the anti-aging agent was added thereto, and the resultant was kneaded again to improve dispersibility of the silica. Also in this case, the discharging temperature for the compound was adjusted to 155 to 160° C. by the temperature control of the mixer. After cooling, as a third stage of the kneading, sulfur and the vulcanization accelerators 1 and 2 were added, and the resultant was kneaded by an open roll set to 70° C. to obtain a rubber composition. Thereafter, the resultant rubber composition was molded and vulcanized at 160° C. for 20 minutes by a vulcanizing press. The rubber composition prior to the vulcanization, and the rubber composition after the vulcanization were evaluated. Specifically, evaluations were performed as described below.

[0618] Results of Application Comparative Examples 11 to 15, Application Examples 19 to 30, Application Comparative Example 19, and Application Examples 34 and 35 are shown in Tables 5-1 to 5-3.

[0619] Results of Application Comparative Example 16 and Application Example 31 are shown in Table 6.

[0620] (Mooney Viscosity of Compound)

[0621] Each compound obtained after the second stage of the kneading and before the third stage of the kneading was used as a sample to measure a viscosity by using a Mooney viscometer in accordance with ISO 289 after preheating the compound at 130° C. for 1 minute, and after rotating a rotor for 4 minutes at 2 rpm.

[0622] A result of each of Application Comparative Examples 12 and 13 and Application Examples 19 to 24 was shown as an index obtained assuming that a result of Application Comparative Example 11 was 100. A result of each of Application Examples 25 to 27 was shown as an index obtained assuming that a result of Application Comparative Example 14 was 100. A result of each of Application Examples 28 to 30 was shown as an index obtained assuming that a result of Application Comparative Example 15 was 100. A result of each of Application Examples 34 and 35 was shown as an index obtained assuming that a result of Application Comparative Example 19 was 100. A result of each of Application Example 31 and Application Comparative Example 16 obtained under the compounding conditions E was shown as an index obtained assuming that a result of Application Comparative Example 17 obtained under compounding conditions F described below was 100. A lower index indicates better processability.

[0623] A sample having an index of 79 or less was evaluated as very good (shown as ⊚⊚ in the tables), a sample having an index of 80 to 89 was evaluated as good (shown as ⊚ in the tables), a sample having an index of 90 to 99 was evaluated to have no practical problem (shown as ◯) in the tables), a sample having an index of 100 to 105 was evaluated as rather poor (shown as Δ in the tables), and a sample having an index of 105 or more was evaluated to have a practical problem (shown as X in the tables).

[0624] (Breaking Strength and Elongation at Break, and Fracture Performance)

[0625] Breaking strength and elongation at break were measured in accordance with a tensile test method according to JIS K6251. In addition, a product of measured values of breaking strength and elongation at break was defined as fracture performance. A result of each of Application Comparative Examples 12 and 13 and Application Examples 19 to 24 was shown as an index obtained assuming that a result of Application Comparative Example 11 was 100. A result of each of Application Examples 25 to 27 was shown as an index obtained assuming that a result of Application Comparative Example 14 was 100. A result of each of Application Examples 28 to 30 was shown as an index obtained assuming that a result of Application Comparative Example 15 was 100. A result of each of Application Examples 34 and 35 was shown as an index obtained assuming that a result of Application Comparative Example 19 was 100. A result of each of Application Example 31 and Application Comparative Example 16 obtained under the compounding conditions E was shown as an index obtained assuming that a result of Application Comparative Example 17 obtained under compounding conditions F described below was 100. A higher index indicates that breaking strength, elongation at break, and fracture performance are better.

[0626] A sample having an index of 121 or more was evaluated as very good (shown as ⊚⊚ in the tables), a sample having an index of 111 to 120 was evaluated as good (shown as ⊚ in the tables), a sample having an index of 101 to 110 was evaluated to have no practical problem (shown as ◯ in the tables), a sample having an index of 95 to 100 was evaluated as rather poor (shown as Δ in the tables), and a sample having an index of 94 or less was evaluated to have a practical problem (shown as X in the tables).

[0627] (Low Fuel Consumption Performance)

[0628] A viscoelasticity testing machine “ARES” manufactured by Rheometric Scientific, Inc. was used to measure a viscoelasticity parameter in a torsion mode.

[0629] A tan δ measured at 50° C. at a frequency of 10 Hz and strain of 3% was used as an index of fuel efficiency.

[0630] A result of each of Application Comparative Examples 12 and 13 and Application Examples 19 to 24 was shown as an index obtained assuming that a result of Application Comparative Example 11 was 100. A result of each of Application Examples 25 to 27 was shown as an index obtained assuming that a result of Application Comparative Example 14 was 100. A result of each of Application Examples 28 to 30 was shown as an index obtained assuming that a result of Application Comparative Example 15 was 100. A result of each of Application Examples 34 and 35 was shown as an index obtained assuming that a result of Application Comparative Example 19 was 100. A result of each of Application Example 31 and Application Comparative Example 16 obtained under the compounding conditions E was shown as an index obtained assuming that a result of Application Comparative Example 17 obtained under compounding conditions F described below was 100.

[0631] A sample having an index of 121 or more was evaluated as very good (shown as ⊚⊚ in the tables), a sample having an index of 111 to 120 was evaluated as good (shown as ⊚ in the tables), a sample having an index of 101 to 110 was evaluated to have no practical problem (shown as ◯ in the tables), a sample having an index of 95 to 100 was evaluated as rather poor (shown as Δ in the tables), and a sample having an index of 94 or less may be deteriorated in fuel efficiency as compared with a standard product, and may be lowered in grade of labelling system (shown as X in the tables). Results are shown in Tables 5-1 to 5-3, and Table 6.

Application Example 32 and Application Comparative Example 17

[0632] Samples C18 and C19 shown in Tables 4-3 were used as raw material rubber components to obtain rubber compositions containing the respective raw material rubber components in accordance with the following compounding conditions F.

[0633] (Rubber Component) [0634] Conjugated diene-based polymer composition or hydrogenated conjugated diene-based polymer composition (each of Samples C18 and C19): 100 parts by mass (parts by mass excluding a rubber softener)

[0635] (Compounding Conditions F)

[0636] An amount of each agent to be compounded is expressed in parts by mass based on 100 parts by mass of a rubber component not containing a rubber softener. [0637] Silica 1 (trade name “Ultrasil 7000GR” manufactured by Evonik Degussa, nitrogen adsorption specific surface area: 170 m.sup.2/g): 50.0 parts by mass [0638] Silica 2 (trade name “Zeosil Premium 200MP” manufactured by Rhodia, nitrogen adsorption specific surface area: 220 m.sup.2/g): 25.0 parts by mass [0639] Carbon black (trade name “Seast KH (N339)”, manufactured by Tokai Carbon Co., Ltd.): 5.0 parts by mass [0640] Silane coupling agent: (trade name “Si75”, manufactured by Evonik Degussa, bis(triethoxysilylpropyl)disulfide): 6.0 parts by mass [0641] SRAE oil (trade name “Process NC140”, manufactured by JX Nippon Oil & Energy Corporation): 27.5 parts by mass (including an amount precedently added as a rubber softener to be contained in each of Samples C18, C19) [0642] Zinc oxide: 2.5 parts by mass [0643] Stearic acid: 1.0 part by mass [0644] Anti-aging agent (N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine): 2.0 parts by mass [0645] Sulfur: 2.2 parts by mass [0646] Vulcanization accelerator 1 (N-cyclohexyl-2-benzothiazylsulfinamide): 1.7 parts by mass [0647] Vulcanization accelerator 2 (diphenylguanidine): 2.0 parts by mass

[0648] Total: 224.9 parts by mass

[0649] (Kneading Method)

[0650] The above-described materials were kneaded by the following method to obtain a rubber composition. A closed kneader (having an internal volume of 0.3 L) equipped with a temperature controller was used to knead, as a first stage of kneading, the raw material rubber component (Sample C18, C19), the fillers (silica 1, silica 2 and carbon black), the silane coupling agent, the SRAE oil, zinc oxide and stearic acid under conditions of a filling ratio of 65% and a rotor rotation speed of 30 to 50 rpm. Here, the temperature of the closed mixer was controlled to obtain each rubber composition (compound) at a discharging temperature of 155 to 160° C.

[0651] Next, after cooling the compound obtained as described above to room temperature, as a second stage of the kneading, the anti-aging agent was added thereto, and the resultant was kneaded again to improve dispersibility of the silica. Also in this case, the discharging temperature for the compound was adjusted to 155 to 160° C. by the temperature control of the mixer. After cooling, as a third stage of the kneading, sulfur and the vulcanization accelerators 1 and 2 were added, and the resultant was kneaded by an open roll set to 70° C. to obtain a rubber composition. Thereafter, the resultant rubber composition was molded and vulcanized at 160° C. for 20 minutes by a vulcanizing press. The rubber composition prior to the vulcanization, and the rubber composition after the vulcanization were evaluated. Specifically, evaluations were performed as described below. Results are shown in Table 6.

[0652] [Mooney Viscosity of Compound]

[0653] Each compound obtained after the second stage of the kneading and before the third stage of the kneading was used as a sample to measure a viscosity by using a Mooney viscometer in accordance with ISO 289 after preheating the compound at 130° C. for 1 minute, and after rotating a rotor for 4 minutes at 2 rpm.

[0654] A result of Application Example 32 obtained under the compounding conditions F was shown as an index obtained assuming that a result of Application Comparative Example 17 obtained under the compounding conditions F was 100. A lower index indicates better processability.

[0655] A sample having an index of 79 or less was evaluated as very good (shown as ⊚⊚ in the tables), a sample having an index of 80 to 89 was evaluated as good (shown as ⊚ in the tables), a sample having an index of 90 to 99 was evaluated to have no practical problem (shown as ◯ in the tables), a sample having an index of 100 to 105 was evaluated as rather poor (shown as Δ in the tables), and a sample having an index of 105 or more was evaluated to have a practical problem (shown as X in the tables).

[0656] (Breaking Strength and Elongation at Break, and Fracture Performance)

[0657] Breaking strength and elongation at break were measured in accordance with a tensile test method according to JIS K6251. In addition, a product of measured values of breaking strength and elongation at break was defined as fracture performance.

[0658] A result of Application Example 32 obtained under the compounding conditions F was shown as an index obtained assuming that a result of Application Comparative Example 17 obtained under the compounding conditions F was 100. A lower index indicates better processability. A higher index indicates that breaking strength, elongation at break (fracture strength), and fracture performance are better.

[0659] A sample having an index of 121 or more was evaluated as very good (shown as ⊚⊚ in the tables), a sample having an index of 111 to 120 was evaluated as good (shown as ⊚ in the tables), a sample having an index of 101 to 110 was evaluated to have no practical problem (shown as ◯ in the tables), a sample having an index of 95 to 100 was evaluated as rather poor (shown as Δ in the tables), and a sample having an index of 94 or less was evaluated to have a practical problem (shown as X in the tables).

[0660] (Low Fuel Consumption Performance)

[0661] A viscoelasticity testing machine “ARES” manufactured by Rheometric Scientific, Inc. was used to measure a viscoelasticity parameter in a torsion mode.

[0662] A tan δ measured at 50° C. at a frequency of 10 Hz and strain of 3% was used as an index of fuel efficiency.

[0663] A result of Application Example 32 obtained under the compounding conditions F was shown as an index obtained assuming that a result of Application Comparative Example 17 obtained under the compounding conditions F was 100.

[0664] A sample having an index of 121 or more was evaluated as very good (shown as ⊚⊚ in the tables), a sample having an index of 111 to 120 was evaluated as good (shown as ⊚ in the tables), a sample having an index of 101 to 110 was evaluated to have no practical problem (shown as ◯ in the tables), a sample having an index of 95 to 100 was evaluated as rather poor (shown as Δ in the tables), and a sample having an index of 94 or less may be deteriorated in fuel efficiency as compared with a standard product, and may be lowered in grade of labelling system (shown as X in the tables). Results are shown in Tables 5-1 to 5-3, and Table 6.

TABLE-US-00016 TABLE 5-1 Application Application Application Comparative Comparative Comparative Application Application Example 11 Example 12 Example 13 Example 19 Example 20 (Hydrogenated) Conjugated Type C1 C2 C3 C4 C5 Diene-based Polymer Composition Compounding Conditions — E E E E E Physical Mooney Viscosity of Index 100 85 83  80  83 Properties of Compound Δ ⊚ ⊚ ⊚ ⊚ Composition Breaking Index 100 87 90 110 115 Strength Δ X X ◯ ⊚ Elongation at Index 100 92 93 105 110 Break Δ X X ◯ ◯ Fracture Index 100 80 84 116 127 Performance Δ X X ⊚ ⊚⊚ Low Fuel Index 100 85 101  116  97 Consumption Δ X ◯ ⊚ Δ Performance Application Application Application Application Example 21 Example 22 Example 23 Example 24 (Hydrogenated) Conjugated Type C6 C7 C8 C9 Diene-based Polymer Composition Compounding Conditions — E E E E Physical Mooney Viscosity of Index  86  86  88  90 Properties of Compound ⊚ ⊚ ⊚ ◯ Composition Breaking Index 120 110 115 120 Strength ⊚ ◯ ⊚ ⊚ Elongation at Index 115 110 115 120 Break ⊚ ◯ ⊚ ⊚ Fracture Index 138 121 132 144 Performance ⊚⊚ ⊚⊚ ⊚⊚ ⊚⊚ Low Fuel Index  89 108 102  91 Consumption X ◯ ◯ X Performance

TABLE-US-00017 TABLE 5-2 Application Comparative Application Application Application Example 14 Example 25 Example 26 Example 27 (Hydrogenated) Conjugated Type C10 C11 C12 C13 Diene-based Polymer Composition Compounding Conditions — E E E E Physical Mooney Viscosity of Index 100  81  84  87 Properties of Compound Δ ⊚ ⊚ ⊚ Composition Breaking Index 100 105 110 115 Strength Δ ◯ ◯ ⊚ Elongation at Index 100 100 105 110 Break Δ Δ ◯ ◯ Fracture Index 100 105 116 127 Performance Δ ◯ ⊚ ⊚⊚ Low Fuel Index 100 112 103  88 Consumption Δ ⊚ ◯ X Performance

TABLE-US-00018 TABLE 5-3 Application Comparative Application Application Application Example 15 Example 28 Example 29 Example 30 (Hydrogenated) Conjugated Type C14 C15 C16 C17 Diene-based Polymer Composition Compounding Conditions — E E E E Physical Mooney Viscosity of Index 100  85  88  91 Properties of Compound Δ ⊚ ⊚ ◯ Composition Breaking Index 100 100 105 110 Strength Δ Δ ◯ ◯ Elongation at Index 100 100 100 105 Break Δ Δ Δ ◯ Fracture Index 100 100 105 116 Performance Δ Δ ◯ ⊚ Low Fuel Index 100 110 101  88 Consumption Δ ◯ ◯ X Performance

TABLE-US-00019 TABLE 6 Application Application Application Comparative Comparative Application Application Comparative Application Application Example 16 Example 17 Example 31 Example 32 Example 19 Example 34 Example 35 (Hydrogenated) Conjugated Type C18 C18 C19 C19 C20 C21 C22 Diene-based Polymer Composition Compounding Conditions — E F E F E E E Physical Mooney Viscosity of Index 87 100  85  98 100 104  93 Properties of Compound ⊚ Δ ⊚ ◯ Δ Δ ◯ Composition Breaking Index 85 100 110 130 100 104 114 Strength X Δ ◯ ⊚⊚ Δ ◯ ◯ Elongation at Index 105 100 105 100 100 102 108 Break ◯ Δ ◯ Δ Δ Δ ◯ Fracture Index 89 100 116 130 100 106 123 Performance X Δ ⊚ ⊚⊚ Δ ◯ ⊚⊚ Low Fuel Index 94 100  92 103 100 107 116 Consumption X Δ X ◯ Δ ◯ ⊚ Performance

Application Examples 36 to 54 and Application Comparative Examples 20 to 24

[0665] By employing raw material rubber components and compounding conditions G-1 to G-13 shown in Table 7-1 and Table 7-2, rubber compositions containing the respective raw material rubber components were obtained by a kneading method similar to that employed under the compounding conditions C.

[0666] Besides, a Mooney viscosity of a compound, breaking strength, elongation at break, fracture performance and low fuel consumption performance were measured by methods similar to the evaluation methods for the rubber compositions performed before and after vulcanization.

[0667] A result of each of Application Examples 36 to 46 was shown as an index obtained assuming that a result of Application Comparative Example 20 was 100. A result of Application Example 47 was shown as an index obtained assuming that a result of Application Comparative Example 21 was 100. A result of Application Example 48 was shown as an index obtained assuming that a result of Application Comparative Example 22 was 100. A result of each of Application Examples 49 to 52 was shown as an index obtained assuming that a result of Application Comparative Example 23 was 100. A result of each of Application Examples 53 and 54 was shown as an index obtained assuming that a result of Application Comparative Example 24 was 100.

[0668] Evaluation results are shown in Table 8-1 and Table 8-2.

TABLE-US-00020 TABLE 7-1 Application Comparative Application Application Application Application Application Example 20 Example 36 Example 37 Example 38 Example 39 Example 40 Compounding Conditions G-1 G-1 G-2 G-3 G-4 G-5 (Hydrogenated) Conjugated B11 B12 B12 B12 B12 B12 Diene-based Polymer Compounding (Hydrogenated) parts by 100 100 100 100 100 100 Composition Conjugated Diene- mass based Polymer Silica 3 parts by 70 70 70 70 mass Silica 4 parts by 70 mass Silica 5 parts by 70 mass Carbon Black 2 parts by 5 5 5 5 mass Carbon Black 3 parts by 5 mass SRAE Oil parts by mass Softener 1 parts by 35 35 35 35 35 mass Softener 2 parts by 35 mass Softener 3 parts by mass Softener 4 parts by mass Softener 5 parts by mass Softener 6 parts by mass Silane Coupling parts by 5.6 5.6 5.6 5.6 5.6 5.6 Agent 2 mass Silane Coupling parts by Agent 3 mass Silane Coupling parts by Agent 4 mass Zinc Oxide parts by 2.5 2.5 2.5 2.5 2.5 2.5 mass Stearic Acid parts by 2 2 2 2 2 2 mass Wax parts by 1 1 1 1 1 1 mass Anti-aging Agent parts by 1.5 1.5 1.5 1.5 1.5 1.5 mass Sulfur parts by 1.5 1.5 1.5 1.5 1.5 1.5 mass Vulcanization parts by 2 2 2 2 2 2 Accelerator 1 mass Vulcanization parts by 1 1 1 1 1 1 Accelerator 2 mass Application Application Application Application Application Application Example 41 Example 42 Example 43 Example 44 Example 45 Example 46 Compounding Conditions G-6 G-7 G-8 G-9 G-10 G-11 (Hydrogenated) Conjugated B12 B12 B12 B12 B12 B12 Diene-based Polymer Compounding (Hydrogenated) parts by 100 100 100 100 100 100 Composition Conjugated Diene- mass based Polymer Silica 3 parts by 70 70 70 70 70 70 mass Silica 4 parts by mass Silica 5 parts by mass Carbon Black 2 parts by mass Carbon Black 3 parts by mass SRAE Oil parts by mass Softener 1 parts by 35 35 mass Softener 2 parts by mass Softener 3 parts by 35 mass Softener 4 parts by 35 mass Softener 5 parts by 35 mass Softener 6 parts by 35 mass Silane Coupling parts by 5.6 5.6 5.6 5.6 Agent 2 mass Silane Coupling parts by 5.6 Agent 3 mass Silane Coupling parts by 5.6 Agent 4 mass Zinc Oxide parts by 2.5 2.5 2.5 2.5 2.5 2.5 mass Stearic Acid parts by 2 2 2 2 2 2 mass Wax parts by 1 1 1 1 1 1 mass Anti-aging Agent parts by 1.5 1.5 1.5 1.5 1.5 1.5 mass Sulfur parts by 1.5 1.5 1.5 1.5 1.5 1.5 mass Vulcanization parts by 2 2 2 2 2 2 Accelerator 1 mass Vulcanization parts by 1 1 1 1 1 1 Accelerator 2 mass [0669] Silica 3: VN3 manufactured by Evonik Degussa (N2SA: 175 m.sup.2/g) [0670] Silica 4: 115GR manufactured by Solvay Japan, Ltd. (N2SA: 115 m.sup.2/g) [0671] Silica 5: 9000GR manufactured by Evonik Degussa (N2SA: 235 m.sup.2/g) [0672] Carbon black 2: Dia Black N339 manufactured by Mitsubishi Chemical Corporation (N2SA: 96 m.sup.2/g, DBP absorption: 124 mL/100 g) [0673] Carbon black 3: Show Black N330 manufactured by Cabot Japan K.K. (N2SA: 75 m.sup.2/g) [0674] SRAE oil (trade name “Process NC140” manufactured by JX Nippon Oil & Energy Corporation) [0675] Softener 1: Diana Process AH-24 (aroma oil) manufactured by Idemitsu Kosan Co., Ltd. [0676] Softener 2: SYLVARES SA85 manufactured by Arizona Chemical Company (a methylstyrene-based resin (copolymer of α-methylstyrene and styrene), softening point: 85° C.) [0677] Softener 3: RICON 100 manufactured by Sartomer (liquid SBR, styrene content: 20% by mass, vinyl content: 70% by mass, weight average molecular weight: 4,500) [0678] Softener 4: NOVARES C100 manufactured by Rutgers Chemicals (coumarone-indene resin, softening point: 95 to 105° C.) [0679] Softener 5: Dercolyte L120 manufactured by DRT (polylimonene resin, softening point: 120° C.) [0680] Softener 6: Sylvatraxx 4150 manufactured by KRATON (polyterpene resin, softening point: 150°) [0681] Silane coupling agent 2: Si266 manufactured by Evonik Degussa [0682] Silane coupling agent 3: Si69 manufactured by Evonik Degussa [0683] Silane coupling agent 4: Si363 manufactured by Evonik Degussa [0684] Anti-aging agent: N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine [0685] Wax: Ozoace 0355 manufactured by Nippon Seiro Co., Ltd. [0686] Vulcanization accelerator 1: N-cyclohexyl-2-benzothiazylsulfinamide [0687] Vulcanization accelerator 2: diphenylguanidine

TABLE-US-00021 TABLE 7-2 Application Application Application Comparative Application Comparative Application Comparative Application Example 21 Example 47 Example 22 Example 48 Example 23 Example 49 Compounding Conditions G-12 G-12 G-12 G-12 G-13 G-13 (Hydrogenated) Conjugated B1 B4 B11 B13 C1 C4 Diene-based Polymer Composition Compounding (Hydrogenated) parts by 100 100 100 100 100 100 Composition Conjugated Diene- mass based Polymer (Composition) Silica 3 parts by 70 70 70 70 70 70 mass Silica 4 parts by mass Silica 5 parts by mass Carbon Black 2 parts by 5 5 5 5 5 5 mass Carbon Black 3 parts by mass SRAE Oil parts by 25 25 mass Softener 1 parts by mass Softener 2 parts by mass Softener 3 parts by mass Softener 4 parts by mass Softener 5 parts by 35 35 35 35 20 20 mass Softener 6 parts by mass Silane Coupling parts by 5.6 5.6 5.6 5.6 5.6 5.6 Agent 2 mass Silane Coupling parts by Agent 3 mass Silane Coupling parts by Agent 4 mass Zinc Oxide parts by 2.5 2.5 2.5 2.5 2.5 2.5 mass Stearic Acid parts by 2 2 2 2 2 2 mass Wax parts by 1 1 1 1 1 1 mass Anti-aging Agent parts by 1.5 1.5 1.5 1.5 1.5 1.5 mass Sulfur parts by 1.5 1.5 1.5 1.5 1.5 1.5 mass Vulcanization parts by 2 2 2 2 2 2 Accelerator 1 mass Vulcanization parts by 1 1 1 1 1 1 Accelerator 2 mass Application Application Application Application Comparative Application Application Example 50 Example 51 Example 52 Example 24 Example 53 Example 54 Compounding Conditions G-13 G-13 G-13 G-13 G-13 G-13 (Hydrogenated) Conjugated C6 C7 C9 C18 C21 C22 Diene-based Polymer Composition Compounding (Hydrogenated) parts by 100 100 100 100 100 100 Composition Conjugated Diene- mass based Polymer (Composition) Silica 3 parts by 70 70 70 70 70 70 mass Silica 4 parts by mass Silica 5 parts by mass Carbon Black 2 parts by 5 5 5 5 5 5 mass Carbon Black 3 parts by mass SRAE Oil parts by 25 25 25 25 25 25 mass Softener 1 parts by mass Softener 2 parts by mass Softener 3 parts by mass Softener 4 parts by mass Softener 5 parts by 20 20 20 20 20 20 mass Softener 6 parts by mass Silane Coupling parts by 5.6 5.6 5.6 5.6 5.6 5.6 Agent 2 mass Silane Coupling parts by Agent 3 mass Silane Coupling parts by Agent 4 mass Zinc Oxide parts by 2.5 2.5 2.5 2.5 2.5 2.5 mass Stearic Acid parts by 2 2 2 2 2 2 mass Wax parts by 1 1 1 1 1 1 mass Anti-aging Agent parts by 1.5 1.5 1.5 1.5 1.5 1.5 mass Sulfur parts by 1.5 1.5 1.5 1.5 1.5 1.5 mass Vulcanization parts by 2 2 2 2 2 2 Accelerator 1 mass Vulcanization parts by 1 1 1 1 1 1 Accelerator 2 mass

TABLE-US-00022 TABLE 8-1 Application Comparative Application Application Application Application Application Example 20 Example 36 Example 37 Example 38 Example 39 Example 40 Physical Mooney Viscosity of Index 100  97  94 102  95 102 Properties of Compound Δ ◯ ◯ Δ ◯ Δ Composition Breaking Index 100 108 101 102 108 117 Strength Δ ◯ ◯ ◯ ◯ ⊚ Elongation at Index 100 107 109 115 109 112 Break Δ ◯ ◯ ⊚ ◯ ◯ Fracture Index 100 116 110 117 118 131 Performance Δ ⊚ ◯ ⊚ ⊚ ⊚⊚ Application Application Application Application Application Application Example 41 Example 42 Example 43 Example 44 Example 45 Example 46 Physical Mooney Viscosity of Index 104 100 104 100 103 103 Properties of Compound Δ Δ Δ Δ Δ Δ Composition Breaking Index 114 108 115 122 108 121 Strength ⊚ ◯ ⊚ ⊚⊚ ◯ ⊚⊚ Elongation at Index 110 112 120 104 118 109 Break ◯ ⊚ ⊚ ◯ ⊚ ◯ Fracture Index 125 121 138 127 127 132 Performance ⊚⊚ ⊚⊚ ⊚⊚ ⊚⊚ ⊚⊚ ⊚⊚

TABLE-US-00023 TABLE 8-2 Application Application Application Comparative Application Comparative Application Comparative Application Example 21 Example 47 Example 22 Example 48 Example 23 Example 49 Physical Mooney Viscosity of Index 100 102 100  94 100  74 Properties of Compound Δ Δ Δ ◯ Δ ⊚⊚ Composition Breaking Index 100 104 100 116 100 112 Strength Δ ◯ Δ ⊚ Δ ⊚ Elongation at Index 100 105 100 115 100 108 Break Δ ◯ Δ ⊚ Δ ◯ Fracture Index 100 109 100 133 100 121 Performance Δ ◯ Δ ⊚⊚ Δ ⊚⊚ Application Application Application Application Comparative Application Application Example 50 Example 51 Example 52 Example 24 Example 53 Example 54 Physical Mooney Viscosity of Index  84  98 104 100 104  92 Properties of Compound ⊚ ◯ Δ Δ Δ ◯ Composition Breaking Index 129 104 106 100 103 116 Strength ⊚⊚ ◯ ◯ Δ ◯ ⊚ Elongation at Index 121 103 107 100 101 110 Break ⊚⊚ ◯ ◯ Δ ◯ ◯ Fracture Index 156 107 113 100 104 128 Performance ⊚⊚ ◯ ⊚ Δ ◯ ⊚⊚

[0688] As shown in Tables 1-1 to 1-5, Tables 2-1 to 2-5, Table 3, Tables 4-1 to 4-4, Tables 5-1 to 5-3, Table 6, Tables 7-1 to 7-2, and Tables 8-1 to 8-2, it was also confirmed that, in the hydrogenated conjugated diene-based polymers or the hydrogenated conjugated diene-based polymer compositions of Examples 1 to 30 and Examples 31 to 33, cold flow is suppressed, the Mooney viscosity of compound obtained when used for obtaining a vulcanizate therefrom is low, and good processability is exhibited as compared with those of Comparative Examples 1 to 15 and Comparative Example 16.

[0689] In addition, as shown in Tables 2-1 to 2-5, Table 3, Tables 5-1 to 5-3, Table 6, Tables 7-1 to 7-2, and Tables 8-1 to 8-2, it was confirmed that the rubber compositions of Application Examples 1 to 32 and Application Examples 33 to 54 are excellent in breaking strength, elongation at break, and fracture performance when in the form of a vulcanizate as compared with those of Application Comparative Examples 1 to 17 and Application Comparative Examples 19 to 24. In particular, it was confirmed, based on the results of Application Examples 1, 5, 6, 9, 10, 12, 15, 16, and 33, that balance between strength and low fuel consumption performance is very excellent when a hydrogenation rate is in a range of 39 to 80%.

[0690] This application is based upon the prior Japanese patent application (Japanese Patent Application No. 2020-068489) filed on Apr. 6, 2020, and the prior Japanese patent application (Japanese Patent Application No. 2020-068479) filed on Apr. 6, 2020, the entire contents of which are incorporated herein by reference.

INDUSTRIAL APPLICABILITY

[0691] A hydrogenated conjugated diene-based polymer of the present invention is industrially applicable as a material or the like of tire treads, interiors/exteriors of vehicles, anti-vibration rubbers, belts, shoes, foam bodies, and various industrial products.