Polymer and asphalt composition

Abstract

The present invention provides a polymer comprising conjugated diene monomer units and vinyl aromatic monomer units, wherein the polymer has a polymer block (A) comprising principally vinyl aromatic monomer units, and a polymer block (B) comprising conjugated diene monomer units and vinyl aromatic monomer units, and has a Bragg spacing of 27 nm or larger and 50 nm or smaller.

Claims

1. A polymer comprising a conjugated diene monomer unit and a vinyl aromatic monomer unit, wherein the polymer has a polymer block (A) comprising principally a vinyl aromatic monomer unit, and a polymer block (B) comprising a conjugated diene monomer unit and a vinyl aromatic monomer unit, the polymer has a Bragg spacing of 27 nm or larger and 50 nm or smaller, the polymer has a peak top of loss tangent (tan ) in the range of 55 to 10 C. in a dynamic viscoelastic spectrum, the polymer has a functional group, and a value of the peak top is 0.7 or higher and 1.5 or lower.

2. The polymer according to claim 1, wherein a rate of hydrogenation of a double bond in the conjugated diene monomer unit is 0 mol % or higher and 90 mol % or lower.

3. The polymer according to claim 1, wherein the rate of hydrogenation of the double bond in the conjugated diene monomer unit is 50 mol % or higher and 90 mol % or lower.

4. The polymer according to claim 1, wherein the rate of hydrogenation of the double bond in the conjugated diene monomer unit exceeds 90 mol %.

5. The polymer according to claim 1, wherein the value of the peak top is 0.8 or higher and 1.3 or lower.

6. The polymer according to claim 5, wherein the value of the peak top is 0.9 or higher and 1.2 or lower.

7. The polymer according to claim 1, wherein a content of the vinyl aromatic monomer unit is 20% by mass or larger and 60% by mass or smaller.

8. The polymer according to claim 1, wherein the content of the polymer block (A) is 10% by mass or larger and 40% by mass or smaller.

9. The polymer according to claim 1, wherein the content of a short-chain vinyl aromatic monomer-polymerized moiety comprising 2 to 6 vinyl aromatic monomer units in the polymer block (B) is 50% by mass or larger based on the content of the vinyl aromatic monomer unit in the polymer block (B) defined as 100% by mass.

10. The polymer according to claim 9, wherein a content of a short-chain vinyl aromatic monomer-polymerized moiety in the polymer block (B) is 70% by mass or larger based on the content of the vinyl aromatic monomer unit in the polymer block (B) defined as 100% by mass.

11. The polymer according to claim 1, wherein the conjugated diene monomer unit consist of a conjugated diene monomer unit (a) derived from 1,2-bond and/or 3,4-bond and a conjugated diene monomer unit (b) derived from 1,4-bond, and when a total content of the conjugated diene monomer unit is defined as 100% by mass, a content of an alkenyl monomer unit (a1) of a hydrogenated part of the conjugated diene monomer unit (a) is 10% by mass or larger and 50% by mass or smaller, a content of an alkenyl monomer unit (b1) of a hydrogenated part of the conjugated diene monomer unit (b) is 0% by mass or larger and 80% by mass or smaller, and the sum of the contents of an unhydrogenated conjugated diene monomer unit (a) and an unhydrogenated conjugated diene monomer unit (b) after hydrogenation is 0% by mass or larger and 90% by mass or smaller.

12. The polymer according to claim 1, wherein the polymer has a weight-average molecular weight of 50000 or higher and 400000 or lower.

13. The polymer according to claim 1, wherein the content of the conjugated diene monomer unit (a) derived from 1,2-bond and/or 3,4-bond is 10 mol % or higher and 50 mol % or lower based on the total content of the conjugated diene monomer unit.

14. An asphalt composition comprising 0.5 parts by mass or more and 50 parts by mass or less of the polymer according to claim 1 and 100 parts by mass of asphalt.

15. An asphalt composition comprising 0.5 parts by mass or more and 50 parts by mass or less in total of the polymer according to claim 1 and a block copolymer (), and 100 parts by mass of asphalt, wherein the block copolymer () has at least one polymer block (A) comprising principally a vinyl aromatic monomer unit, and at least one polymer block (C) comprising principally a conjugated diene monomer unit, and a content of the block copolymer () is 15 to 85% by mass in the total amount of the polymer and the block copolymer ().

16. The asphalt composition according to claim 14, further comprising 0.03 parts by mass or more and 3 parts by mass or less of sulfur and/or a sulfur compound based on 100 parts by mass of the asphalt.

17. The asphalt composition according to claim 15, further comprising 0.03 parts by mass or more and 3 parts by mass or less of sulfur and/or a sulfur compound based on 100 parts by mass of the asphalt.

18. An asphalt composition comprising 0.5 parts by mass or more and 50 parts by mass or less of the polymer according to claim 1 and 100 parts by mass of asphalt.

19. An asphalt composition comprising 0.5 parts by mass or more and 50 parts by mass or less in total of the polymer according to claim 1 and a block copolymer (), and 100 parts by mass of asphalt, wherein the block copolymer () has at least one polymer block (A) comprising principally a vinyl aromatic monomer unit, and at least one polymer block (C) comprising principally a conjugated diene monomer unit, and a content of the block copolymer () is 15 to 85% by mass in the total amount of the polymer and the block copolymer ().

Description

EXAMPLES

(1) Hereinafter, the present invention will be described specifically with reference to Examples. However, the present invention is not intended to be limited by these Examples by any means.

(2) Measurement methods for polymers and asphalt compositions in Examples and Comparative Examples are as described below.

(3) [Measurement Method]

(4) <Content of Vinyl Aromatic Monomer Unit (Styrene Content) in Polymer>

(5) A given amount of each polymer was dissolved in chloroform and assayed using an ultraviolet spectrophotometer (manufactured by Shimadzu Corp., UV-2450). The content of the vinyl aromatic monomer units (styrene) was calculated using a calibration curve from the peak intensity of an absorption wavelength (262 nm) attributed to the vinyl aromatic compound (styrene).

(6) <Content of Polymer Block (A) in Polymer>

(7) The content of the polymer block (A) was measured by the osmium tetroxide method described in I. M. Kolthoff, et al., J. Polym. Sci. 1, p. 429 (1946) using each polymer before hydrogenation.

(8) A solution of 0.1 g of osmic acid in 125 mL of tertiary butanol was used in the decomposition of the polymer.

(9) <Vinyl Bond Content in Polymer and Rate of Hydrogenation of Double Bond in Conjugated Diene Monomer Unit>

(10) The vinyl bond content in each polymer and the rate of hydrogenation of double bonds in the conjugated diene monomer units were measured by nuclear magnetic resonance spectrum analysis (NMR) under conditions given below.

(11) Both of the vinyl bond content and the rate of hydrogenation were measured using a polymer sample after hydrogenation reaction. The polymer after hydrogenation was precipitated and recovered by the addition of a large amount of methanol to the reaction solution after hydrogenation reaction.

(12) Subsequently, the polymer after hydrogenation was extracted with acetone, and the extract was dried in vacuum and used as a sample for 1H-NMR measurement.

(13) The conditions for the 1H-NMR measurement will be described below.

(14) (Measurement Conditions)

(15) Measurement apparatus: JNM-LA400 (manufactured by JEOL Ltd.)

(16) Solvent: deuterated chloroform

(17) Measurement sample: polymer extracts obtained before and after hydrogenation

(18) Sample concentration: 50 mg/mL

(19) Observation frequency: 400 MHz

(20) Chemical shift standard: TMS (tetramethylsilane)

(21) Pulse delay: 2.904 seconds

(22) The number of scans: 64

(23) Pulse width: 45

(24) Measurement temperature: 26 C.

(25) <Dynamic Viscoelastic Spectrum>

(26) The loss tangent (tan ) was determined by the measurement of a viscoelastic spectrum using a viscoelastic measurement analyzer ARES (trade name; manufactured by TA Instruments Japan Inc.). A sample for measurement was loaded in a twisted-type geometry and assayed at a strain of 0.5% and a measurement frequency of 1 Hz.

(27) In this way, the peak height of the loss tangent (tan ) and the temperature at which the peak existed were measured.

(28) <Weight-Average Molecular Weight and Molecular Weight Distribution>

(29) The weight-average molecular weight (Mw) and molecular weight distribution (Mw/Mn) of each polymer were measured by GPC [apparatus: manufactured by Waters Corp.].

(30) The solvent used was tetrahydrofuran, and the measurement was carried out at a temperature of 35 C.

(31) The weight-average molecular weight (polystyrene-based molecular weight) and the number-average molecular weight were determined by checking a molecular weight at a peak of a chromatogram against a calibration curve determined from the measurement of commercially available standard polystyrenes (prepared using the peak molecular weights of the standard polystyrenes). The molecular weight distribution was determined from the ratio between the obtained weight-average molecular weight and number-average molecular weight.

(32) <Content of short-chain vinyl aromatic monomer-polymerized moiety (short-chain styrene content)>

(33) Oxygen having a (O.sub.3) concentration of 1.5% was allowed to pass at a rate of 150 mL/min through a dichloromethane solution of each polymer for oxidative decomposition. The obtained ozonide was reduced by dropwise addition into diethyl ether mixed with lithium aluminum hydride.

(34) Next, the resulting product was hydrolyzed by the addition of pure water and salted-out by the addition of potassium carbonate, followed by filtration to obtain a vinyl aromatic hydrocarbon component.

(35) This vinyl aromatic hydrocarbon component was assayed by GPC.

(36) The area ratio of the peak thus obtained (peak area corresponding to the short-chain vinyl aromatic monomer-polymerized moiety/total area of the peak) was calculated to obtain the content of the short-chain vinyl aromatic monomer-polymerized moiety based on 100% by mass of the vinyl aromatic monomer units in the polymer block (B) contained in the polymer.

(37) The ozone generator used was model OT-31R-2 manufactured by Nippon Ozone Generator Co., Ltd., and the GPC measurement was carried out at a flow rate of 1.0 mL/min and a column oven temperature of 35 C. by using 2487 manufactured by Waters Corp., chloroform as a solvent, and two columns (Shodex column-K803L) connected.

(38) <Bragg Spacing>

(39) The Bragg spacing of each polymer was measured using a nanoscale X-ray structural evaluation apparatus NANO-Viewer [apparatus: manufactured by Rigaku Corp.] and PILATUS 100K (two-dimensional semiconductor detector).

(40) The two-dimensional SAXS pattern obtained in PILATUS 100K was corrected for background and blank cell scattering. Then, the circular average was obtained to determine a one-dimensional scattering profile.

(41) The primary peak position (2m) of scattering derived from a microphase separation structure was read out from the one-dimensional scattering profile, and the interdomain space d, i.e., Bragg spacing, was calculated according to the Bragg equation (1):
d=/2/sin(m)(1)

(42) m: Bragg angle at the primary peak position of scattering

(43) <Method for Calculating X, Y, and Z>

(44) The rate of hydrogenation is represented by H, and the vinyl bond content is represented by V.

(45) X is indicated by X=V when HV and X=H when H<V.

(46) Y is indicated by HV provided that Y is absent when HV.

(47) Z is indicated by 100H.

(48) [Method for Producing Polymer]

(49) (Preparation of Hydrogenation Catalyst)

(50) A reaction vessel purged with nitrogen was charged with 2 L of dried and purified cyclohexane. After dissolution of 40 mmol of bis(5-cyclopentadienyl)titanium di-(p-tolyl) and 150 g of 1,2-polybutadiene (1,2-vinyl bond content: approximately 85%) having a molecular weight of approximately 1,000, a cyclohexane solution containing 60 mmol of n-butyllithium was added thereto, and the mixture was reacted at room temperature for 5 minutes. Immediately thereafter, 40 mmol of n-butanol was added thereto, and the mixture was stirred and stored at room temperature.

(51) (Polymer 1)

(52) Polymerization was carried out by the following method using a vessel-type reactor (internal volume: 10 L) with a stirrer and a jacket.

(53) The reactor was charged with 10 parts by mass of cyclohexane. After temperature adjustment to 70 C., 0.12% by mass of n-butyllithium based on the mass of all monomers (total amount of butadiene monomers and styrene monomers added to the reactor) and 0.4 mol of N,N,N,N-tetramethylethylenediamine (hereinafter, referred to as TMEDA) based on 1 mol of n-butyllithium were added to the reactor. Then, a cyclohexane solution containing 10 parts by mass of styrene as monomers (monomer concentration: 22% by mass) was added thereto over approximately 3 minutes, and the mixture was reacted for 30 minutes while the internal temperature of the reactor was adjusted to approximately 70 C.

(54) Next, a cyclohexane solution containing 59 parts by mass of butadiene (monomer concentration: 22% by mass) and a cyclohexane solution containing 21 parts by mass of styrene (monomer concentration: 22% by mass) were continuously supplied to the reactor at a constant rate over 20 minutes and 10 minutes, respectively. The specific energy (value obtained by dividing stirring power by the amount of the reaction solution in the polymerization vessel) was adjusted to 0.30 kw/m.sup.3, and the internal pressure of the reactor was set to 0.30 MPa, followed by reaction for 30 minutes. During this operation, the internal temperature of the reactor was adjusted to approximately 70 C.

(55) Then, a cyclohexane solution containing 10 parts by mass of styrene as monomers (monomer concentration: 22% by mass) was further added thereto over approximately 3 minutes, and the mixture was reacted for 30 minutes while the internal temperature of the reactor was adjusted to approximately 70 C. and the internal pressure of the reactor was adjusted to 0.30 MPa to obtain a polymer.

(56) Next, the hydrogenation catalyst described above was added at 90 ppm (in terms of titanium) based on the mass of the polymer to the obtained polymer, and hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 65 C. After the completion of the reaction, methanol was added to the polymer, and 0.3% by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate based on the mass of the polymer was then added thereto as a stabilizer to obtain a hydrogenated polymer. The rate of hydrogenation was 83%.

(57) (Polymer 2)

(58) The amount of styrene supplied at the first stage was changed to 11 parts by mass; the amounts of butadiene and styrene supplied at the second stage were changed to 55 parts by mass and 23 parts by mass, respectively; the duration of time required for the completion of addition of butadiene was changed to 30 minutes; and the amount of styrene supplied at the third stage was changed to 11 parts by mass. Polymerization was carried out in the same way as in the polymer 1 except for the above.

(59) Next, a hydrogenated polymer was obtained through the same hydrogenation reaction as in the polymer 1 except that the hydrogenation catalyst described above was added at 95 ppm (in terms of titanium) based on the mass of the polymer to the obtained polymer.

(60) The rate of hydrogenation was 89%.

(61) (Polymer 3)

(62) The amount of n-butyllithium supplied was changed to 0.125% by mass; the amount of styrene supplied at the first stage was changed to 12 parts by mass; the amounts of butadiene and styrene supplied at the second stage were changed to 63 parts by mass and 14 parts by mass, respectively; and the amount of styrene supplied at the third stage was changed to 11 parts by mass. Polymerization was carried out in the same way as in the polymer 1 except for the above.

(63) Next, a hydrogenated polymer was obtained through the same hydrogenation reaction as in the polymer 1 except that the hydrogenation catalyst described above was added at 85 ppm (in terms of titanium) based on the mass of the polymer to the obtained polymer.

(64) The rate of hydrogenation was 66%.

(65) (Polymer 4)

(66) The amount of n-butyllithium supplied was changed to 0.115% by mass; the amount of styrene supplied at the first stage was changed to 15 parts by mass; the amounts of butadiene and styrene supplied at the second stage were changed to 51 parts by mass and 19 parts by mass, respectively; the duration of time required for the completion of addition of butadiene was changed to 35 minutes; the specific energy was adjusted to 0.38 kw/m.sup.3, and the internal temperature of the reactor was adjusted to 75 C.; and the amount of styrene supplied at the third stage was changed to 15 parts by mass. Polymerization was carried out in the same way as in the polymer 1 except for the above.

(67) Next, a hydrogenated polymer was obtained through the same hydrogenation reaction as in the polymer 1 except that the hydrogenation catalyst described above was added at 65 ppm (in terms of titanium) based on the mass of the polymer to the obtained polymer.

(68) The rate of hydrogenation was 34%.

(69) (Polymer 5)

(70) The amount of styrene supplied at the first stage was changed to 10 parts by mass; the amounts of butadiene and styrene supplied at the second stage were changed to 56 parts by mass and 25 parts by mass, respectively; the duration of time required for the completion of addition of butadiene was changed to 30 minutes; and the amount of styrene supplied at the third stage was changed to 9 parts by mass. Polymerization was carried out in the same way as in the polymer 1 except for the above.

(71) Polymer 5 was obtained without hydrogenation reaction.

(72) The rate of hydrogenation was 0%.

(73) (Polymer 6)

(74) The amount of styrene supplied at the first stage was changed to 11 parts by mass; the amounts of butadiene and styrene supplied at the second stage were changed to 59 parts by mass and 20 parts by mass, respectively; the duration of time required for the completion of addition of butadiene was changed to 30 minutes; and the amount of styrene supplied at the third stage was changed to 10 parts by mass. Polymerization was carried out in the same way as in the polymer 1 except for the above.

(75) Next, a hydrogenated polymer was obtained through the same hydrogenation reaction as in the polymer 1 except that the hydrogenation catalyst described above was added at 95 ppm (in terms of titanium) based on the mass of the polymer to the obtained polymer.

(76) The rate of hydrogenation was 85%.

(77) (Polymer 7)

(78) The amount of n-butyllithium supplied was changed to 0.095% by mass; the amount of styrene supplied at the first stage was changed to 9 parts by mass; the amounts of butadiene and styrene supplied at the second stage were changed to 60 parts by mass and 22 parts by mass, respectively; the duration of time required for the completion of addition of butadiene was changed to 30 minutes; the specific energy was adjusted to 0.44 kw/m.sup.3; and the amount of styrene supplied at the third stage was changed to 9 parts by mass. Polymerization was carried out in the same way as in the polymer 1 except for the above.

(79) Next, a hydrogenated polymer was obtained through the same hydrogenation reaction as in the polymer 1 except that the hydrogenation catalyst described above was added at 95 ppm (in terms of titanium) based on the mass of the polymer to the obtained polymer.

(80) The rate of hydrogenation was 85%.

(81) (Polymer 8)

(82) The amount of n-butyllithium supplied was changed to 0.080% by mass; the amount of styrene supplied at the first stage was changed to 11 parts by mass; the amounts of butadiene and styrene supplied at the second stage were changed to 59 parts by mass and 20 parts by mass, respectively; the duration of time required for the completion of addition of butadiene was changed to 28 minutes; the specific energy was adjusted to 0.46 kw/m.sup.3; and the amount of styrene supplied at the third stage was changed to 10 parts by mass. Polymerization was carried out in the same way as in the polymer 1 except for the above.

(83) Next, a hydrogenated polymer was obtained through the same hydrogenation reaction as in the polymer 1 except that the hydrogenation catalyst described above was added at 90 ppm (in terms of titanium) based on the mass of the polymer to the obtained polymer.

(84) The rate of hydrogenation was 80%.

(85) (Polymer 9)

(86) The amount of n-butyllithium supplied was changed to 0.115% by mass; the amount of styrene supplied at the first stage was changed to 11 parts by mass; the amounts of butadiene and styrene supplied at the second stage were changed to 58 parts by mass and 21 parts by mass, respectively; and the duration of time required for the completion of addition of butadiene was changed to 30 minutes. Polymerization was carried out in the same way as in the polymer 1 except for the above.

(87) Then, 1,3-dimethyl-2-imidazolidinone was added at 0.95 mol based on 1 mol of n-butyllithium, and the mixture was reacted for 25 minutes.

(88) Next, a hydrogenated polymer was obtained through the same hydrogenation reaction as in the polymer 1 except that the hydrogenation catalyst described above was added at 90 ppm (in terms of titanium) based on the mass of the polymer to the obtained polymer.

(89) The rate of hydrogenation was 84%.

(90) (Polymer 10)

(91) The amount of n-butyllithium supplied was changed to 0.095% by mass; the amount of styrene supplied at the first stage was changed to 11 parts by mass; the amounts of butadiene and styrene supplied at the second stage were changed to 58 parts by mass and 21 parts by mass, respectively; and the duration of time required for the completion of addition of butadiene was changed to 30 minutes. Polymerization was carried out in the same way as in the polymer 1 except for the above.

(92) Next, a hydrogenated polymer was obtained through the same hydrogenation reaction as in the polymer 1 except that the hydrogenation catalyst described above was added at 80 ppm (in terms of titanium) based on the mass of the polymer to the obtained polymer.

(93) The rate of hydrogenation was 64%.

(94) (Polymer 11)

(95) The amount of n-butyllithium supplied was changed to 0.125% by mass; the amount of styrene supplied at the first stage was changed to 23 parts by mass; the amounts of butadiene and styrene supplied at the second stage were changed to 50 parts by mass and 5 parts by mass, respectively; the duration of time required for the completion of addition of butadiene was changed to 30 minutes; and the amount of styrene supplied at the third stage was changed to 22 parts by mass. Polymerization was carried out in the same way as in the polymer 1 except for the above.

(96) Next, the obtained polymer was subjected to the same hydrogenation reaction as in the polymer 1 to obtain a hydrogenated polymer.

(97) The rate of hydrogenation was 84%.

(98) (Polymer 12)

(99) Polymerization was carried out in the same way as in the polymer 1 except that: the amount of styrene supplied at the first stage was changed to 9 parts by mass; the amounts of butadiene and styrene supplied at the second stage were changed to 60 parts by mass and 22 parts by mass, respectively; the duration of time required for the completion of addition of butadiene was changed to 8 minutes; the amount of styrene supplied at the third stage was changed to 9 parts by mass; and the specific energy was adjusted to 0.42 kw/m.sup.3.

(100) Next, a hydrogenated polymer was obtained through the same hydrogenation reaction as in the polymer 1 except that the hydrogenation catalyst described above was added at 85 ppm (in terms of titanium) based on the mass of the polymer to the obtained polymer.

(101) The rate of hydrogenation was 75%.

(102) (Polymer 13)

(103) The amount of styrene supplied at the first stage was changed to 13 parts by mass; the amounts of butadiene and styrene supplied at the second stage were changed to 52 parts by mass and 22 parts by mass, respectively; the duration of time required for the completion of addition of butadiene was changed to 30 minutes; the internal temperature of the reactor was adjusted to 75 C.; and the amount of styrene supplied at the third stage was changed to 13 parts by mass. Polymerization was carried out in the same way as in the polymer 1 except for the above.

(104) Next, a hydrogenated polymer was obtained through the same hydrogenation reaction as in the polymer 1 except that the hydrogenation catalyst described above was added at 100 ppm (in terms of titanium) based on the mass of the polymer to the obtained polymer.

(105) The rate of hydrogenation was 96%.

(106) (Polymer 14)

(107) A polymer was obtained in the same way as in the polymer 1 by changing the amounts of monomers, etc., supplied to the reactor.

(108) The amount of n-butyllithium supplied was changed to 0.13% by mass; the amounts of butadiene and styrene supplied at the second stage were changed to 50 parts by mass and 30 parts by mass, respectively; the duration of time required for the completion of addition of butadiene was changed to 40 minutes; the internal temperature of the reactor was adjusted to 85 C., and the internal pressure of the reactor was adjusted to 0.42 MPa; and the specific energy was adjusted to 0.35 kw/m.sup.3. Polymerization was carried out in the same way as in the polymer 1 except for the above.

(109) Next, a hydrogenated polymer was obtained through the same hydrogenation reaction as in the polymer 1 except that the hydrogenation catalyst described above was added at 85 ppm (in terms of titanium) based on the mass of the polymer to the obtained polymer.

(110) The rate of hydrogenation was 70%.

(111) (Polymer 15)

(112) The amount of n-butyllithium supplied was changed to 0.125% by mass; the amount of styrene supplied at the first stage was changed to 20 parts by mass; the amount of butadiene supplied at the second stage was changed to 61 parts by mass, while styrene was not added at the second stage; and the amount of styrene supplied at the third stage was changed to 19 parts by mass. Polymerization was carried out in the same way as in the polymer 1 except for the above.

(113) Polymer 15 was obtained without hydrogenation reaction.

(114) The rate of hydrogenation was 0%.

(115) (Polymer 16)

(116) A vessel-type reactor with a jacket was used. The reactor was charged with a predetermined amount of cyclohexane, and the internal temperature of the reactor was adjusted to 60 C.

(117) Then, 0.12 parts by mass of n-butyllithium based on 100 parts by mass of all monomers (total amount of butadiene monomers and styrene monomers added to the reactor) were added from the bottom of the reactor.

(118) 0.40 mol of a cyclohexane solution of N,N,N,N-tetramethylethylenediamine based on 1 mol of n-butyllithium was further added thereto.

(119) Then, for polymerization reaction in the first step, a cyclohexane solution containing 10 parts by mass of styrene as monomers (monomer concentration: 15% by mass) was supplied thereto over approximately 10 minutes, and the internal temperature of the reactor was adjusted to 65 C.

(120) After the completion of the supply, the mixture was reacted for 15 minutes.

(121) Next, for polymerization reaction in the second step, a cyclohexane solution containing 57 parts by mass of butadiene (monomer concentration: 15% by mass) and a cyclohexane solution containing 23 parts by mass of styrene (monomer concentration: 15% by mass) were each continuously supplied to the reactor at a constant rate over 60 minutes. The specific energy was adjusted to 0.30 kw/m.sup.3, and the internal pressure of the reactor was set to 0.30 MPa, followed by reaction. After the completion of the supply, the mixture was reacted for 15 minutes.

(122) Next, for polymerization reaction in the third step, a cyclohexane solution containing 10 parts by mass of styrene (monomer concentration: 15% by mass) was supplied to the reactor over approximately 10 minutes, and the internal temperature of the reactor was adjusted to 65 C. After the completion of the supply, the mixture was reacted for 15 minutes.

(123) Next, the hydrogenation catalyst described above was added at 100 ppm (in terms of titanium) based on the mass of the polymer to the obtained polymer, and hydrogenation reaction was carried out at a hydrogen pressure of 0.7 MPa and a temperature of 65 C.

(124) After the completion of the reaction, an aqueous methanol solution was added to the polymer, and 0.1% by mass of octadecyl-3-(3,5-di-t-butyl-4-hydroxyphenyl) propionate based on the mass of the polymer was then added thereto as a stabilizer.

(125) (Polymer 17)

(126) 0.085 parts by mass of n-butyllithium based on 100 parts by mass of all monomers (total amount of butadiene monomers and styrene monomers added to the reactor) were added from the bottom of the reactor; the polymerization temperature was set to 55 C.; the first step was carried out by using a cyclohexane solution containing 11 parts by mass of styrene (monomer concentration: 15% by mass); the second step was carried out by using a cyclohexane solution containing 58 parts by mass of butadiene (monomer concentration: 15% by mass) and a cyclohexane solution containing 20 parts by mass of styrene (monomer concentration: 15% by mass), and adjusting the specific energy to 0.35 kw/m.sup.3; the third step was carried out by using a cyclohexane solution containing 11 parts by mass of styrene (monomer concentration: 15% by mass); and the hydrogenation catalyst was added at 95 ppm. Polymerization was carried out in the same way as in the polymer 16 except for the above.

(127) (Polymer 18)

(128) 0.125 parts by mass of n-butyllithium based on 100 parts by mass of all monomers (total amount of butadiene monomers and styrene monomers added to the reactor) were added from the bottom of the reactor; the polymerization temperature was set to 65 C.; the first step was carried out by using a cyclohexane solution containing 11 parts by mass of styrene (monomer concentration: 15% by mass); the second step was carried out by using a cyclohexane solution containing 45 parts by mass of butadiene (monomer concentration: 15% by mass) and a cyclohexane solution containing 33 parts by mass of styrene (monomer concentration: 15% by mass), and adjusting the specific energy to 0.25 kw/m.sup.3; and the third step was carried out by using a cyclohexane solution containing 11 parts by mass of styrene (monomer concentration: 15% by mass). Polymerization was carried out in the same way as in the polymer 16 except for the above.

(129) (Polymer 19)

(130) 0.115 parts by mass of n-butyllithium based on 100 parts by mass of all monomers (total amount of butadiene monomers and styrene monomers added to the reactor) were added from the bottom of the reactor; the polymerization temperature was set to 65 C.; the first step was carried out by using a cyclohexane solution containing 18 parts by mass of styrene (monomer concentration: 15% by mass); the second step was carried out by using a cyclohexane solution containing 50 parts by mass of butadiene (monomer concentration: 15% by mass) and a cyclohexane solution containing 14 parts by mass of styrene (monomer concentration: 15% by mass), and adjusting the specific energy to 0.32 kw/m.sup.3; and the third step was carried out by using a cyclohexane solution containing 18 parts by mass of styrene (monomer concentration: 15% by mass). Polymerization was carried out in the same way as in the polymer 16 except for the above.

(131) (Polymer 20)

(132) 0.125 parts by mass of n-butyllithium based on 100 parts by mass of all monomers (total amount of butadiene monomers and styrene monomers added to the reactor) were added from the bottom of the reactor; the polymerization temperature was set to 65 C.; the first step was carried out by using a cyclohexane solution containing 11 parts by mass of styrene (monomer concentration: 20% by mass); the second step was carried out by supplying a cyclohexane solution containing 57 parts by mass of butadiene (monomer concentration: 20% by mass) and a cyclohexane solution containing 21 parts by mass of styrene (monomer concentration: 20% by mass) in 3 portions each at 5-minute intervals, and adjusting the specific energy to 0.32 kw/m.sup.3; and the third step was carried out by using a cyclohexane solution containing 11 parts by mass of styrene (monomer concentration: 20% by mass). Polymerization was carried out in the same way as in the polymer 16 except for the above.

(133) (Polymer 21)

(134) The first step was carried out by using a cyclohexane solution containing 10 parts by mass of styrene (monomer concentration: 25% by mass); the second step was carried out by adding a cyclohexane solution containing 60 parts by mass of butadiene (monomer concentration: 25% by mass) and a cyclohexane solution containing 21 parts by mass of styrene (monomer concentration: 25% by mass) over 10 minutes each, and adjusting the specific energy to 0.32 kw/m.sup.3; and the third step was carried out by using a cyclohexane solution containing 9 parts by mass of styrene (monomer concentration: 25% by mass). Polymerization was carried out in the same way as in the polymer 16 except for the above.

(135) (Polymer 22)

(136) 0.125 parts by mass of n-butyllithium based on 100 parts by mass of all monomers (total amount of butadiene monomers and styrene monomers added to the reactor) were added from the bottom of the reactor; the polymerization temperature was set to 56 C.; the first step was carried out by using a cyclohexane solution containing 11 parts by mass of styrene (monomer concentration: 15% by mass); the second step was carried out by continuously supplying a cyclohexane solution containing 57 parts by mass of butadiene (monomer concentration: 15% by mass) and a cyclohexane solution containing 21 parts by mass of styrene (monomer concentration: 15% by mass) to the reactor at a constant rate over 55 minutes each, and adjusting the specific energy to 0.32 kw/m.sup.3 and the internal pressure of the reactor to 0.25 MPa, followed by reaction; and the third step was carried out by using a cyclohexane solution containing 11 parts by mass of styrene (monomer concentration: 15% by mass). Polymerization was carried out in the same way as in the polymer 16 except for the above.

(137) (Polymer 23)

(138) 0.085 parts by mass of n-butyllithium based on 100 parts by mass of all monomers (total amount of butadiene monomers and styrene monomers added to the reactor) were added from the bottom of the reactor; the polymerization temperature was set to 50 C.; the first step was carried out by using a cyclohexane solution containing 17 parts by mass of styrene (monomer concentration: 15% by mass) and setting the internal temperature of the reactor to 53 C.; the second step was carried out by continuously supplying a cyclohexane solution containing 43 parts by mass of butadiene (monomer concentration: 15% by mass) and a cyclohexane solution containing 24 parts by mass of styrene (monomer concentration: 15% by mass) to the reactor at a constant rate over 55 minutes each, and adjusting the specific energy to 0.42 kw/m.sup.3 and the internal pressure of the reactor to 0.15 MPa, followed by reaction; and the third step was carried out by using a cyclohexane solution containing 16 parts by mass of styrene (monomer concentration: 15% by mass). Polymerization was carried out in the same way as in the polymer 16 except for the above.

(139) (Polymer 24)

(140) 0.100 parts by mass of n-butyllithium based on 100 parts by mass of all monomers (total amount of butadiene monomers and styrene monomers added to the reactor) were added from the bottom of the reactor; the polymerization temperature was set to 57 C.; and the second step was carried out by continuously supplying a cyclohexane solution containing 60 parts by mass of butadiene (monomer concentration: 15% by mass) and a cyclohexane solution containing 20 parts by mass of styrene (monomer concentration: 15% by mass) to the reactor at a constant rate over 57 minutes each, and adjusting the specific energy to 0.42 kw/m.sup.3. Polymerization was carried out in the same way as in the polymer 16 except for the above.

(141) (Polymer 25)

(142) 0.080 parts by mass of n-butyllithium based on 100 parts by mass of all monomers (total amount of butadiene monomers and styrene monomers added to the reactor) were added from the bottom of the reactor; the polymerization temperature was set to 56 C.; and the second step was carried out by continuously supplying a cyclohexane solution containing 60 parts by mass of butadiene (monomer concentration: 15% by mass) and a cyclohexane solution containing 20 parts by mass of styrene (monomer concentration: 15% by mass) to the reactor at a constant rate over 59 minutes each, and adjusting the specific energy to 0.46 kw/m.sup.3. Polymerization was carried out in the same way as in the polymer 16 except for the above.

(143) (Polymer 26)

(144) 0.085 parts by mass of n-butyllithium based on 100 parts by mass of all monomers (total amount of butadiene monomers and styrene monomers added to the reactor) were added from the bottom of the reactor; the polymerization temperature was set to 55 C.; the first step was carried out by using a cyclohexane solution containing 11 parts by mass of styrene (monomer concentration: 15% by mass); and the polymerization in the second step was carried out by using a cyclohexane solution containing 59 parts by mass of butadiene (monomer concentration: 15% by mass) and a cyclohexane solution containing 20 parts by mass of styrene (monomer concentration: 15% by mass), and adjusting the specific energy to 0.35 kw/m.sup.3.

(145) Then, 0.95 mol of 1,3-dimethyl-2-imidazolidinone based on 1 mol of n-butyllithium was added to the reactor, and the mixture was reacted for 25 minutes.

(146) Next, the hydrogenation catalyst was added at 95 ppm to the obtained polymer. Polymerization was carried out in the same way as in the polymer 16 except for the above.

(147) (Polymer 27)

(148) 0.130 parts by mass of n-butyllithium based on 100 parts by mass of all monomers (total amount of butadiene monomers and styrene monomers added to the reactor) were added from the bottom of the reactor; the polymerization temperature was set to 85 C.; the first step was carried out by using a cyclohexane solution containing 8 parts by mass of styrene (monomer concentration: 15% by mass); the second step was carried out by continuously supplying a cyclohexane solution containing 50 parts by mass of butadiene (monomer concentration: 15% by mass) and a cyclohexane solution containing 35 parts by mass of styrene (monomer concentration: 15% by mass) to the reactor at a constant rate over 60 minutes each, and adjusting the specific energy to 0.08 kw/m.sup.3 and the internal pressure of the reactor to 0.32 MPa, followed by reaction; and the third step was carried out by using a cyclohexane solution containing 7 parts by mass of styrene (monomer concentration: 15% by mass). Polymerization was carried out in the same way as in the polymer 16 except for the above.

(149) (Polymer 28)

(150) 0.140 parts by mass of n-butyllithium based on 100 parts by mass of all monomers (total amount of butadiene monomers and styrene monomers added to the reactor) were added from the bottom of the reactor; the polymerization temperature was set to 56 C.; the first step was carried out by using a cyclohexane solution containing 11 parts by mass of styrene (monomer concentration: 15% by mass); the second step was carried out by continuously supplying a cyclohexane solution containing 59 parts by mass of butadiene (monomer concentration: 15% by mass) and a cyclohexane solution containing 19 parts by mass of styrene (monomer concentration: 15% by mass) to the reactor at a constant rate over 55 minutes each, and adjusting the specific energy to 0.09 kw/m.sup.3 and the internal pressure of the reactor to 0.25 MPa, followed by reaction; and the third step was carried out by using a cyclohexane solution containing 11 parts by mass of styrene (monomer concentration: 15% by mass). Polymerization was carried out in the same way as in the polymer 16 except for the above.

(151) (Polymer 29)

(152) 0.080 parts by mass of n-butyllithium based on 100 parts by mass of all monomers (total amount of butadiene monomers and styrene monomers added to the reactor) were added from the bottom of the reactor; the polymerization temperature was set to 55 C.; the first step was carried out by using a cyclohexane solution containing 10 parts by mass of styrene (monomer concentration: 15% by mass); the second step was carried out by using a cyclohexane solution containing 57 parts by mass of butadiene (monomer concentration: 15% by mass) and a cyclohexane solution containing 24 parts by mass of styrene (monomer concentration: 15% by mass), and adjusting the specific energy to 0.35 kw/m.sup.3; the third step was carried out by using a cyclohexane solution containing 9 parts by mass of styrene (monomer concentration: 15% by mass); and the hydrogenation catalyst was added at 85 ppm. Polymerization was carried out in the same way as in the polymer 16 except for the above.

(153) (Polymer 30)

(154) 0.085 parts by mass of n-butyllithium based on 100 parts by mass of all monomers (total amount of butadiene monomers and styrene monomers added to the reactor) were added from the bottom of the reactor; the polymerization temperature was set to 55 C.; the first step was carried out by using a cyclohexane solution containing 11 parts by mass of styrene (monomer concentration: 15% by mass); the second step was carried out by using a cyclohexane solution containing 58 parts by mass of butadiene (monomer concentration: 15% by mass) and a cyclohexane solution containing 20 parts by mass of styrene (monomer concentration: 15% by mass), and adjusting the specific energy to 0.39 kw/m.sup.3; the third step was carried out by using a cyclohexane solution containing 11 parts by mass of styrene (monomer concentration: 15% by mass); and hydrogenation reaction was not carried out. Polymerization was carried out in the same way as in the polymer 16 except for the above.

(155) (Polymer 31)

(156) The first step was carried out by using a cyclohexane solution containing 17 parts by mass of styrene (monomer concentration: 15% by mass); the second step was carried out by continuously supplying a cyclohexane solution containing 67 parts by mass of butadiene (monomer concentration: 15% by mass) to the reactor at a constant rate over 60 minutes, and performing the reaction for 15 minutes after the completion of the supply; the third step was carried out by using a cyclohexane solution containing 16 parts by mass of styrene (monomer concentration: 15% by mass); and hydrogenation reaction was not carried out. Polymerization was carried out in the same way as in the polymer 16 except for the above.

(157) TABLE-US-00001 TABLE 1 Content of Vinyl tan peak Short- Styrene polymer block Rate of bond Mw height/tempera- Bragg chain vinyl content (A) hydrogenation content (ten ture spacing content (mass %) (mass %) (mol %) (mol %) thousand) Mw/Mn ( C.) X/Y/Z (nm) (mass %) Polymer 1 41 20 83 32 18 1.1 0.9/35 32/51/17 35.9 94 Polymer 2 45 22 89 29 18 1.1 1.1/32 29/60/11 35.1 93 Polymer 3 37 23 66 26 17 1.1 0.8/40 26/40/34 36.4 71 Polymer 4 49 30 34 33 19 1.1 1.3/40 33/1/66 37.3 62 Polymer 5 44 19 0 30 18 1.1 1.0/30 0/0/100 38.2 90 Polymer 6 41 21 85 32 18 1.1 1.2/34 32/53/15 35.8 93 Polymer 7 40 18 85 31 23 1.1 1.0/31 31/54/15 44.2 90 Polymer 8 41 21 80 30 26 1.1 0.9/30 30/50/20 49.0 91 Polymer 9 42 21 84 30 19 1.1 0.9/35 30/54/16 36.4 92 Polymer 10 42 21 64 28 23 1.1 0.9/9 28/36/36 37.6 91 Polymer 11 50 45 84 33 17 1.1 0.7/43 33/51/16 35.7 93 Polymer 12 40 18 75 20 18 1.1 0.5/36 20/55/25 38.6 45 Polymer 13 48 26 96 30 18 1.1 1.2/30 30/66/4 33.3 87 Polymer 14 50 20 70 37 16 1.1 1.7/30 37/33/30 36.5 90 Polymer 15 39 39 0 21 17 1.1 0.1 or 0/0/100 37.4 0 lower/80

(158) TABLE-US-00002 TABLE 2 Content of Rate of Vinyl tan peak Short- Styrene polymer block hydrogena- bond Mw height/tempera- Bragg chain vinyl content (A) tion content (ten ture spacing content (mass %) (mass %) (mol %) (mol %) thousand) Mw/Mn ( C.) X/Y/Z (nm) (mass %) Polymer 16 43 20 99 27 18 1.1 1.2/31 27/72/1 32.9 90 Polymer 17 42 22 91 28 25 1.1 1.2/33 28/63/9 35.8 91 Polymer 18 55 22 96 28 17 1.1 1.3/15 28/68/4 30.0 87 Polymer 19 50 36 97 27 19 1.1 1.2/41 27/70/3 34.0 92 Polymer 20 43 22 99 29 17 1.1 1.2/37 29/70/1 34.8 75 Polymer 21 40 19 95 30 18 1.1 1.1/43 30/65/5 35.0 47 Polymer 22 43 22 95 30 17 1.1 0.7/32 30/65/5 34.4 80 Polymer 23 57 33 98 33 25 1.1 0.6/16 33/65/2 38.6 68 Polymer 24 40 20 97 29 22 1.1 0.9/29 29/68/3 43.0 90 Polymer 25 40 20 97 28 26 1.1 1.0/28 28/69/3 49.2 91 Polymer 26 41 21 92 30 25 1.1 1.2/31 30/62/8 35.3 89 Polymer 27 50 15 98 28 16 1.1 1.7/13 28/70/2 26.0 93 Polymer 28 41 22 98 28 14 1.1 0.7/30 28/70/2 26.7 83 Polymer 29 43 19 77 27 26 1.1 1.2/31 27/50/23 36.0 88 Polymer 30 42 22 0 30 25 1.1 1.1/35 0/0/100 36.8 93 Polymer 31 33 33 0 17 18 1.1 0.1 or lower 0/0/100 37.7 0

(159) [Production of Asphalt Composition]

(160) In Examples 1 to 36 and Comparative Examples 1 to 5, each asphalt composition was produced by the following procedures.

(161) 500 g of straight asphalt 60-80 (manufactured by Nippon Oil Corp.) was added to a 750 mL metal can, and the metal can was fully immersed in an oil bath of 180 C.

(162) Next, 3.5 parts by mass or 8 parts by mass of the polymer produced as mentioned above based on 100 parts by mass of the asphalt in a melted state were added thereto in small portions with stirring.

(163) After the completion of the addition, the mixture was stirred at a rotation speed of 6000 rpm for 90 minutes to prepare an asphalt composition.

(164) In the polymer addition step mentioned above, polymer 1 and SBS were added at a mixing ratio of 40 parts by mass/60 parts by mass. Then, the mixture was stirred for 180 minutes to produce asphalt compositions of Examples 10 and 11.

(165) Also, polymer 1 and SBS were added at a mixing ratio of 60 parts by mass/40 parts by mass. Then, production was carried out in the same way as in Examples 10 and 11 to produce an asphalt composition of Example 12.

(166) Furthermore, polymer 17 and SBS were added at a mixing ratio of 40 parts by mass/60 parts by mass. Then, production was carried out in the same way as in Examples 10 and 11 described above to produce asphalt compositions of Examples 29 and 30.

(167) Furthermore, polymer 17 and SBS were added at a mixing ratio of 60 parts by mass/40 parts by mass. Then, production was carried out in the same way as in Examples 10 and 11 described above to produce an asphalt composition of Example 31.

(168) The following SBS was used in Examples 10 to 12 and 29 to 31.

(169) Examples 10 and 29: Kraton D1184, which is a radial polymer having a styrene content of 30%, a diblock content of 14.5%, and a polystyrene-based weight-average molecular weight of 400000.

(170) Examples 11, 12, 30, and 31: Kraton D1101, which is a linear polymer having a styrene content of 31%, a diblock content of 17.0%, and a polystyrene-based weight-average molecular weight of 180000.

(171) In the polymer addition step mentioned above, 3.5 parts by mass of polymer 10 based on 100 parts by mass of the asphalt were added in small amounts with stirring. After the completion of the addition, the mixture was stirred at a rotation speed of 6000 rpm for 90 minutes. Then, 0.2 parts by mass of sulfur were added thereto, and the mixture was further stirred for 60 minutes to prepare an asphalt composition of Example 13.

(172) [Preparation of Mixture for Road Pavement]

(173) The asphalt composition obtained in each of Examples 1 to 33 and Comparative Examples 1 to 4 and an aggregate were mixed (total amount of the mixture: 10 kg) using a 27 L experimental mixer equipped with a heating apparatus to obtain an asphalt mixture for road pavement as a dense graded mixture.

(174) Specifically, the aggregate used had crushed stone No. 6/crushed stone No. 7/crushed sand/fine sand/stone dust mixing ratio of 36/19/27/12/6(%), and 5.5 parts by mass of the asphalt composition and 94.5 parts by mass of the aggregate were mixed. In other words, the content of the asphalt composition was set to 5.5% by mass in the mixture for road pavement.

(175) The aggregate used was crushed stone and crushed sand from Iwafune-cho, Shimotsuga-gun, Tochigi, Japan, fine sand from Sakae-cho, Inba-gun, Chiba, Japan, and stone dust from Yamasuge-cho, Sano, Tochigi, Japan.

(176) The particle size distribution of the aggregate used in the production of the asphalt mixture is shown in Table 3 below.

(177) TABLE-US-00003 TABLE 3 Percent weight Aggregate passing (%) Sieve mesh 19 100 (mm) 13.2 99.6 4.75 64.2 2.36 43.1 0.6 27 0.3 19.7 0.15 9.9 0.075 6.1 Amount of asphalt composition (mass %) 5.5

(178) The mixing of the asphalt composition and the aggregate was carried out by the following procedures.

(179) First, 94.5 parts by mass of the dense graded aggregate having a predetermined particle size were added to the mixer and dry-mixed for 25 seconds. Subsequently, 5.5 parts by mass of the asphalt composition obtained in each of Examples 1 to 33 and Comparative Examples 1 to 4 were added to the mixer and finally mixed with the aggregate for 50 seconds to obtain a dense graded mixture for road pavement.

(180) The mixing temperature was 177 C. for both of the dry mixing and the final mixing.

(181) [Physical Property of Asphalt Composition]

(182) The physical properties of each asphalt composition were measured by the methods given below.

(183) The measurement results are shown in Tables 4 to 6 below.

(184) (Softening Point (Ring & Ball Method))

(185) The softening point of the asphalt composition was measured according to JIS-K 2207.

(186) A defined ring was filled with a sample of the asphalt composition and horizontally supported in a glycerin solution. A ball of 3.5 g was placed at the center of the sample, and the temperature of the solution was raised at a rate of 5 C./min. The temperature at which the sample came into contact with the bottom plate of a ring base by the weight of the ball was measured.

(187) (Melt Viscosity)

(188) The melt viscosity was measured at 160 C. using a Brookfield viscometer.

(189) (Penetration)

(190) The penetration was determined according to JIS-K 2207 by measuring the length of penetration of a defined needle for 5 seconds into the sample kept at 25 C. in a constant-temperature water bath.

(191) (Elongation)

(192) The elongation was determined according to JIS-K 2207. The sample was poured into a form, made into a defined shape, and then kept at 15 C. in a constant-temperature water bath. Next, the sample was pulled at a rate of 5 cm/min. The distance of elongation of the sample until the sample broke was measured.

(193) (High-Temperature Storage Stability (Variation in Softening Point))

(194) Immediately after production of the asphalt composition, the asphalt composition was heated for 3 days in an oven of 180 C. Then, the metal can was removed, and the softening point was measured. The difference between the softening point immediately after the production and the softening point after the heating for 3 days was used as an index for the high-temperature storage stability. A smaller difference between the softening points means better high-temperature storage stability.

(195) (Dissolution Time)

(196) The average particle size of the polymer was measured during the production of the asphalt composition, and the time required for the polymer to reach a predetermined size was measured as a dissolution time.

(197) In the measurement method, the polymer was observed using transmitted light under a digital microscope.

(198) The measurement apparatus and the measurement conditions were as follows.

(199) Measurement apparatus: digital microscope VHX-2000 manufactured by Keyence Corp.

(200) Measurement Conditions

(201) Measurement temperature: 25 C.

(202) Magnification: 1000

(203) Measurement mode: transmitted light

(204) Sample adjustment method: 10 mg of the asphalt composition during stirring was collected onto a glass slide, which was then left standing for 20 seconds on a hot plate heated to 180 C. for melting. Then, a glass cover was placed on the melted asphalt composition to thinly spread the asphalt composition. The asphalt composition was left at room temperature for 30 minutes and then observed under a digital microscope. The time in the production when the dispersed particle size reached 10 m was defined as the dissolution time. A shorter time means better solubility.

(205) (Workability)

(206) A dense graded mixture was produced according to the above paragraph [Preparation of mixture for road pavement] and evaluated for easy leveling for construction.

(207) Easier leveling means better performance. The sample was rated as , , and X in order from better to poorer outcomes.

(208) : Easily leveled

(209) : Fair

(210) X: Difficult to level due to lost flowability

(211) (Low-Temperature Elongation)

(212) The elongation of an asphalt composition containing 3.5% by mass of each of polymers 1 to 33 produced by the method described above, or an asphalt composition containing 3.5% by mass in total of polymer 1 or polymer 17 and SBS in each of Examples 10 to 12 and 29 to 31 was measured according to JIS-K 2207.

(213) An asphalt sample having a defined shape was pulled at a rate of 5 cm/min in water of 5 C. The length (cm) of elongation of the sample until the sample broke was measured.

(214) A higher value means higher low-temperature performance. The sample was rated as , , and X in order from better to poorer outcomes.

(215) : 20 cm or more

(216) : 10 cm or more

(217) X: less than 10 cm

(218) (Recovery after Tension)

(219) The asphalt composition produced by the method described above was poured into a dedicated jig to produce a sample for measurement.

(220) The sample was pulled at a rate of 5 cm/min in a water bath of 25 C., and the pulling was terminated when the sample elongated by 20 cm. The sample was left standing for 5 minutes and then cut at the center.

(221) Then, the cut sample was left in a water bath for 60 minutes. The degree of recovery of the sample for measurement based on the original length was measured.

(222) Higher recovery after tension means better performance. The sample was rated as , , , and X in order from better to poorer outcomes.

(223) : 80% or more

(224) : 75% or more and less than 80%

(225) : 70% or more and less than 75%

(226) X: less than 70%

(227) (Heat Aging Resistance of Polymer)

(228) An asphalt composition containing 3.5% by mass of the polymer produced by the method described above was stored at 190 C. and sampled after a lapse of predetermined time. Change in the molecular weight distribution of the polymer was analyzed by GPC. Based on this change, the polymer was evaluated for its heat aging resistance.

(229) The peak height of the polymer obtained in GPC was lowered due to the thermal degradation of the polymer.

(230) Smaller change from the peak height of the polymer before storage means higher heat aging resistance and better performance.

(231) The sample was evaluated on the basis of the number of days required for change in height to reach 30% or more and rated as , , and X in order from better to poorer outcomes. Only the sample rated as was confirmed to have practically sufficient performance.

(232) : 2 days or later

(233) : 1 day or later and less than 2 days

(234) X: less than 1 day.

(235) (Resistance to Aggregate Spalling)

(236) A dense graded asphalt mixture was produced in the same way as in the above paragraph [Preparation of mixture for road pavement].

(237) This asphalt mixture was placed as a specimen in a Los Angeles tester for Marshall stability and subjected to 300 drum rotations without the use of a steel ball. After the test, the amount of loss (resistance to aggregate spalling) was measured.

(238) Lower resistance to aggregate spalling means better performance. The sample was rated as , , , and X in order from better to poorer outcomes.

(239) : less than 20%

(240) : 20% or more and less than 23%

(241) : 23% or more and less than 26%

(242) X: 26% or more

(243) (Dynamic Stability)

(244) A dense graded asphalt mixture was produced in the same way as in the above paragraph [Preparation of mixture for road pavement] and assayed for its dynamic stability according to B003 of the Test Methods Handbook from Japan Road Association.

(245) A loaded small wheel with a rubber tire was repetitively shuttled at a defined speed at a defined temperature for a defined time on a sample for evaluation having a predetermined size. The dynamic stability (pass/mm) was determined from the amount of deformation per unit time.

(246) A higher value means higher rutting resistance. The sample was rated as , , , and X in order from better to poorer outcomes.

(247) : 20000 passes/mm or more

(248) : 10000 passes/mm or more

(249) : 5000 passes/mm or more

(250) X: less than 5000 passes/mm

(251) TABLE-US-00004 TABLE 4 Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- ple 10 ple 1 ple 2 ple 3 ple 4 ple 5 ple 6 ple 7 ple 8 ple 9 Poly- Poly- Poly- Poly- Poly- Poly- Poly- Poly- Poly- Poly- mer 1 + mer 1 mer 2 mer 3 mer 4 mer 5 mer 6 mer 7 mer 8 mer 9 SBS Asphalt Straight asphalt 60-80 Physical Softening point ( C.) 67 70 63 67 66 68 68 73 66 68 prop- Melt viscosity (mPa .Math. s) (160 C.) 422 441 401 407 395 431 460 470 411 439 erties Penetration ( 1/10 mm) 44 41 46 42 44 43 41 41 45 46 Elongation (cm) (15 C.) 70 66 77 75 78 69 80 83 74 74 High-temperature storage stability 2 2 3 3 5 2 2 2 2 4 ( C.) Dissolution time (h) 0.5 0.75 0.5 0.5 1 0.5 1 1.5 0.5 1 Workability Low-temperature elongation (cm) X (5 C.) Recovery after tension X Heat aging resistance X X Resistance to aggregate spalling X (10 C.) Dynamic stability (pass/mm) X Exam- Exam- Exam- ple 11 ple 12 ple 13 Exam- Exam- Exam- Exam- Exam- Exam- Exam- Poly- Poly- Poly- ple 14 ple 15 ple 16 ple 17 ple 18 ple 19 ple 20 mer 1 + mer 1 + mer 10 + Poly- Poly- Poly- Poly- Poly- Poly- Poly- SBS SBS sulfur mer 11 mer 12 mer 13 mer 14 mer 16 mer 17 mer 18 Asphalt Straight asphalt 60-80 Physical Softening point ( C.) 64 66 68 72 66 72 62 68 72 67 prop- Melt viscosity (mPa .Math. s) (160 C.) 416 420 433 496 411 534 481 544 622 613 erties Penetration ( 1/10 mm) 46 45 44 37 44 35 40 34 36 33 Elongation (cm) (15 C.) 71 70 67 59 70 52 62 55 70 52 High-temperature storage stability 4 3 2 3 3 3 3 2 3 2 ( C.) Dissolution time (h) 1 1 0.75 4.5 3 2 2 2 2 2 Workability Low-temperature elongation (cm) X X X (5 C.) Recovery after tension Heat aging resistance X X X X Resistance to aggregate spalling X X (10 C.) Dynamic stability (pass/mm)

(252) TABLE-US-00005 TABLE 5 Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- Exam- ple 29 ple 30 ple 21 ple 22 ple 23 ple 24 ple 25 ple 26 ple 27 ple 28 Poly- Poly- Poly- Poly- Poly- Poly- Poly- Poly- Poly- Poly- mer 17 + mer 17 + mer 19 mer 20 mer 21 mer 22 mer 23 mer 24 mer 25 mer 26 SBS SBS Asphalt Straight asphalt 60-80 Physical Softening point ( C.) 68 69 68 70 73 71 70 70 73 70 prop- Melt viscosity (mPa .Math. s) (160 C.) 606 588 535 560 667 571 603 531 644 571 erties Penetration ( 1/10 mm) 35 34 35 35 32 35 35 36 36 36 Elongation (cm) (15 C.) 56 52 55 54 67 66 71 77 72 69 High-temperature storage stability 2 2 3 3 2 2 2 2 4 4 ( C.) Dissolution time (h) 1.5 1.5 1.5 1.5 4 2 2.5 2 3 3 Workability Low-temperature elongation (cm) X X X X X (5 C.) Recovery after tension X Heat aging resistance Resistance to aggregate spalling X (10 C.) Dynamic stability (pass/mm) Compar- Compar- Compar- Compar- Exam- ative ative ative ative ple 31 Exam- Exam- Exam- Exam- Exam- Exam- Poly- ple 32 ple 33 ple 1 ple 2 ple 3 ple 4 mer 17 + Poly- Poly- Poly- Poly- Poly- Poly- SBS mer 29 mer 30 mer 15 mer 27 mer 28 mer 31 Asphalt Straight asphalt 60-80 Physical Softening point ( C.) 71 67 67 54 59 59 52 prop- Melt viscosity (mPa .Math. s) (160 C.) 599 388 422 351 582 522 366 erties Penetration ( 1/10 mm) 36 43 44 49 35 35 50 Elongation (cm) (15 C.) 70 75 82 92 53 55 96 High-temperature storage stability 4 3 5 8 3 2 9 ( C.) Dissolution time (h) 3 2 4 5 3.5 3 5.5 Workability X X Low-temperature elongation (cm) X X (5 C.) Recovery after tension X X X Heat aging resistance X X X Resistance to aggregate spalling X X X X X X (10 C.) Dynamic stability (pass/mm) X

(253) TABLE-US-00006 TABLE 6 Comparative Example 34 Example 35 Example 36 Example 5 Polymer 1 Polymer 5 Polymer 13 Polymer 15 Component Asphalt Straight asphalt 60-80 Physical Softening point ( C.) 95 90 105 86 properties Melt viscosity (mPa .Math. s) (160 C.) 1905 1814 2233 1775 Penetration ( 1/10 mm) 30 32 28 36 Elongation (cm) (15 C.) 49 53 46 58 Dissolution time (h) 1.5 3 8 20

(254) The present application is based on Japanese Patent Application No. 2014-007293 filed with the Japanese Patent Office on Jan. 17, 2014, Japanese Patent Application No. 2014-085364 filed with the Japanese Patent Office on Apr. 17, 2014, Japanese Patent Application No. 2014-203037 filed with the Japanese Patent Office on Oct. 1, 2014, Japanese Patent Application No. 2014-203038 filed with the Japanese Patent Office on Oct. 1, 2014, Japanese Patent Application No. 2014-232736 filed with the Japanese Patent Office on Nov. 17, 2014, and Japanese Patent Application No. 2014-232737 filed with the Japanese Patent Office on Nov. 17, 2014, the contents of which are incorporated herein by reference in their entirety.

INDUSTRIAL APPLICABILITY

(255) The asphalt composition comprising the polymer of the present invention can be used in the fields of road pavement, roofings or waterproof sheets, and sealants and can be particularly suitably used in the field of road pavement.