METHOD OF PRODUCING A MODIFIED DIENE-CONTAINING RUBBER, THE RUBBER AND A COMPOSITION BASED THEREON

Abstract

The present invention relates to a method of producing a rubber, comprising (co)polymerizing at least one diene monomer and optionally at least one vinylaromatic monomer, and a vinyl-silicone compound, in the presence of a functionalizing lithium initiator, and modifying the obtained (co)polymer by a poly functional silicon-containing agent. The functionalizing lithium initiator is obtained by reacting an organolithium compound, a secondary amine and a diene-containing compound. In addition, the instant inventon relates to rubbers obtained by said method, rubber compositions and vulcanizates based thereon, semi-finished products and tires, comprising such a rubber. The present invention provides obtaining of rubber compositions and vulcanizates based thereon characterized by the improved complex of histeresis properties.

Claims

1. A method of producing a rubber, comprising: a) (co)polymerizing: at least one diene monomer, optionally at least one vinylaromatic monomer, and a vinyl-silicone compound, in the presence of a functionalizing lithium initiator, and b) modifying the obtained (co)polymer by a polyfunctional silicon-containing agent, wherein the functionalizing lithium initiator is obtained by reacting an organolithium compound, a secondary amine and a diene-containing compound.

2. The method according to claim 1, wherein the (co)polymerization is an anionic (co)polymerization in solvent.

3. The method according to claim 1, wherein the diene monomer is selected from the group consisting of conjugated dienes having from 4 to 12 carbon atoms, preferably 1,3-butadiene and/or isoprene.

4. The method according to claim 1, wherein the vinylaromatic monomer is a compound selected from the group comprising: styrene, -methylstyrene, ortho-, meta- and para-methylstyrene, 3-vinyl toluene, ethylvinyl benzene, 4-cyclohexyl styrene, para-tert-butyl styrene, methoxy styrene, vinyl mesitylene, divinyl benzene, 1-vinyl naphthalene, 2,4,6-trimethyl styrene, preferably styrene or a-methylstyrene.

5. The method according to claim 1, wherein the functionalizing lithium initiator is obtained in situ in the reaction mixture of step a), wherein the diene-containing compound is a diene monomer of the step (a) of the (co)polymerization.

6. The method according to claim 1, wherein the vinyl-silicon compound is a compound represented by the general formula (I): ##STR00017## wherein R.sub.1 and R.sub.2 are the same or different and represent optionally substituted C.sub.1-20oalkyl, C.sub.2-20alkenyl, C.sub.3-20cycloalkyl, C.sub.6-20aryl, C.sub.5-20heterocyclyl, C.sub.5-20heteroaryl, or NR.sub.6R.sub.7, or R.sub.1 and R.sub.2 in combination with each other form a 3- to 8-membered saturated or unsaturated ring consisting of carbon atoms and, optionally, of 1 to 3 atoms selected from an oxygen atom, a sulfur atom and a nitrogen atom; R.sub.3 represents NR.sub.6R.sub.7, wherein R.sub.6 and R.sub.7, are the same or different and represent optionally substituted C.sub.1-8alkyl, C.sub.2-8alkenyl, C.sub.3-8cycloalkyl, C.sub.6-10aryl, C.sub.5-10heterocyclyl, C.sub.5-10heteroaryl.

7. The method according to claim 6, wherein R.sub.1 and R.sub.2 in the compound of formula (I) independently represent C.sub.1-20alkyl or C.sub.1-20alkenyl, or C.sub.6-10aryl, NR.sub.6R.sub.7, wherein said groups are optionally substituted with 1 to 3 substituents selected from halogen, C.sub.1-6alkoxy.

8. The method according to claim 7, wherein R.sub.1 and R.sub.2 in the compound of formula (I) independently represent C.sub.1-20alkyl.

9. The method according to claim 6, wherein R.sub.6 and R.sub.7 in the compound of formula (I) independently represent C.sub.1-20alkyl or C.sub.6-20 aryl, wherein said groups are optionally substituted with 1 to 3 substituents selected from halogen, C.sub.1-6alkoxy.

10. The method according to claim 6, wherein the vinyl-silicon compound is vinyl(C.sub.1-20)alkyl-di((C.sub.1-20)alkylamino)silane, vinyl-di(C.sub.1-20)alkyl-((C.sub.1-20)alkylamino)silane or vinyl-tris((C.sub.1-20)alkylamino)silane.

11. The method according to claim 6, wherein the vinyl-silicon compound is a compound selected from vinyl(dimethylamino)dimethylsilane, bis(dimethylamino)vinylmethylsilane, vinyl-tris(dimethylamino)silane, vinyl(dimethylamino)diethylsilane, bis(dimethylamino)vinylethylsilane, vinyl(diethylamino)dimethylsilane, bis(diethylamino)vinylmethylsilane, vinyl-tris(diethylamino)silane, vinyl(diethylamino)diethylsilane, bis(diethylamino)vinylethylsilane, vinyl(dimethylamino)diphenylsilane, bis(dimethylamino)vinylphenylsilane, vinyl(diphenylamino)dimethylsilane, bis(diphenylamino)vinylmethylsilane, vinyl-tris(diphenylamino)silane, preferably represents bis(dimethylamino)vinylmethylsilane.

12. The method according to any one of claims 1 to 11, wherein an amount of the vinyl-silicon compound is from 0.001 to 10 wt. %, preferably from 0.01 to 1 wt. %, more preferably from 0.03 to 0.1 wt. % based on the total amount of monomers.

13. The method according to claim 1, wherein the initiator is preliminary obtained or is obtained in situ in the reaction mixture by reacting an organolithium compound, a secondary amine and diene in equimolar amount in the presence of an electron-donor additive and a solvent.

14. The method according to claim 1, wherein the organolithium compound is C.sub.1-20 alkyllithium, C.sub.6-10aryllithium, C.sub.2-20alkenyllithium, C.sub.2-20alkylenedilithium, C.sub.2-20alkenylenedilithium compounds, and preferably is n-butyl lithium or sec-butyl lithium.

15. The method according to claim 1, wherein the secondary amine is a compound of the general formula (II): ##STR00018## wherein R.sub.a and R.sub.b independently represent optionally substituted C.sub.1-20alkyl, C.sub.2-20alkenyl, C.sub.3-20cycloalkyl, C.sub.6-20aryl, C.sub.5-20heterocyclyl, C.sub.5-20heteroaryl, or R.sub.a and R.sub.b in combination with each other form a 3- to 20-membered saturated or unsaturated ring consisting of carbon atoms and, optionally, of 1 to 3 atoms selected from an oxygen atom, a sulfur atom and a nitrogen atom, said ring optionally comprises 1 to 5 substituents selected from halogen, C.sub.1-6alkyl, C.sub.1-6alkoxy and C.sub.6-10aryl.

16. The method according to claim 15, wherein R.sub.a and R.sub.b in the formula (II) independently represent C.sub.1-20alkyl or C.sub.1-20alkenyl, or C.sub.6-10aryl, said groups are optionally substituted with 1 to 3 substituents selected from halogen and C.sub.1-6alkoxy.

17. The method according to claim 15, wherein the secondary amine is a compound selected from the group comprising dimethylamine, diethylamine, dipropylamine, di-n-butylamine, diisobutylamine, dipentylamine, dihexylamine, diheptylamine, dioctylamine, dicyclohexylamine, N,N-butylisopropylamine, dibenzylamine, methylbenzylamine, methylhexylamine, ethylhexylamine.

18. The method according to claim 15, wherein the secondary amine is a compound selected from the group comprising: pyrrolidine, piperidine, hexamethyleneimine, 2-methylpiperidine, morpholine, thiomorpholine, N-methylpiperazine, N-phenylpiperazine.

19. The method according to claim 1, wherein the diene-containing compound is selected from the group consisting of conjugated dienes having 4 to 12 carbon atoms, preferably represent 1,3-butadiene or isoprene.

20. The method according to claim 1, wherein the initiator is used in an amount of 1 to 50 mole/t of the rubber, preferably from 2 to 25 mole/t of the rubber, more preferably from 3 to 10 mole/t of the rubber.

21. The method according to claim 1, wherein the polyfunctional silicon-containing agent is a compound of the general formula (III): ##STR00019## wherein R.sup.1-R.sup.8 are the same or different and represent alkoxy groups having an alkyl chain C.sub.1-C.sub.20 and/or alkylC.sub.1-C.sub.20 and/or arylC.sub.6-C.sub.12 groups; X.sub.1-X.sub.4 are the same or different and represent epoxy, epoxyC.sub.1-20alkyl, epoxyC.sub.1-20alkylene-oxoalkyl or epoxyC.sub.6-12aryl groups, for example ##STR00020## m, n, k are the same or different and represent an integer of from 0 to 500, preferably from 2 to 100, more preferably from 4 to 50.

22. The method according to claim 1, wherein the silicon-containing agent is used in an amount from 0.01 to 10 wt. %, preferably from 0.1 to 1 wt. %, more preferably from 0.2 to 0.5 wt. % based on the total weight of monomers.

23. The method according to claim 1, wherein the (co)polymerization is carried out at temperature from (30) C. to (+120) C., preferably from 0 C. to 100 C., more preferably from 15 C. to 80 C.

24. The method according to claim 1, further comprising introducing an electron-donor additive to the reaction mixture.

25. The method according to claim 13 or claim 24, wherein the electron-donor additive is selected from the group consisting of ethers and tertiary amines having a boiling point that is lower than 80 C.

26. The method according to claim 25, wherein the electron-donor additive is selected from the group consisting of bis-(2-oxolanyl)methane, 2,2-bis-(2-oxolanyl)propane, (ditetrahydrofurylpropane-DTHFP), 1,1-bis(2-oxolanyl)ethane, 2,2-bis-(2-oxolanyl)butane, 2,2-bis(5-methyl-2-oxolanyl)propane, 2,2-bis(3,4,5-trimethyl-2-oxolanyl)propane, tetrahydrofuran, dialkyl ethers of mono- and oligoalkylene glycols, crown ethers, tertiary amines.

27. The method according to claim 1, comprising: feeding to a polymerization reactor: i) at least one diene monomer, ii) optionally at least one vinylaromatic monomer, iii) a vinyl-silicon compound; introducing a functionalizing initiator to a reaction mixture in the polymerization reactor; and introducing a polyfunctional silicon-containing agent to the reaction mixture until a conversion degree of at least one monomer and the vinyl-silicon compound reaches 95% and more.

29. A rubber obtained by the method according to claim 1.

30. The rubber according to claim 29, wherein the content of 1,2-units is from about 50 to about 80 wt. % based on the diene portion of the rubber.

31. The rubber according to claim 29, wherein a number-average molecular weight of the rubber M.sub.n is from 50000 to 500000.

32. A rubber composition comprising the rubber according to any one of claims 29 to 31 and at least one functional additive.

33. The composition according to claim 32, wherein the functional additive is selected from the group consisting of a reinforcing filler, an oil, a vulcanizing agent, a plasticizer, a softener, an antideteriorant, an antiozonant, an antifatigue, an additive improving the dispersion of fillers and processability of the composition, and combinations thereof.

34. A composition suitable for producing rubber articles, comprising: rubber obtained by the (co)polymerization of at least one diene monomer and optionally at least one vinylaromatic monomer and a vinyl silicon compound in the presence of a functionalizing lithium initiator and by the subsequent modification of the (co)polymer by a polyfunctional silicon-containing agent, wherein the functionalizing lithium initiator is obtained by reacting an organolithium compound, a secondary amide and a diene-containing compound, and at least one functional additive.

35. The composition according to claim 34, wherein the functional additive is selected from the group consisting of a reinforcing filler, an oil, a vulcanizing agent, a plasticizer, a softener, an anti-deteriorant, an antiozonant, an anti-fatigue, an additive improving the dispersion of fillers and processability of the composition, and combinations thereof.

36. The composition according to claim 35, wherein the reinforcing filler is silicon dioxide and/or carbon black.

37. The composition according to claim 34, further comprising butadiene and/or styrene and/or isoprene rubber.

38. A semi-finished product for tire, comprising the composition according to any one of claims 34-37.

39. The semi-finished product according to claim 38, wherein the semi-finished product is selected from a tread, a breaker or a sidewall.

40. A tire tread comprising the composition according to any one of claims 34-37.

41. A tire comprising the composition according to any one of claims 34-37.

Description

EMBODIMENT OF THE INVENTION

[0158] The preliminary obtaining of the functionalizing initiator (Pir-(Bd).sub.t-Li) (on example of pyrrolidine butadiene lithium)

[0159] A process of producing the functionalizing lithium initiator Pir-(Bd).sub.t-Li is carried out in the reactor of the firm Buchi with a glass cup having the useful capacity of 0.5L supplied with the mixer, thermostating jacket, connection pipes and special removable metal dispensers for feeding reagents.

[0160] Toluene (309 ml), THF (15.531 g) and pyrrolidine (9.9554 g) are fed to the reactor in the nitrogen stream and 2.5 M solution of n-butyl lithium in hexane (56 ml) is fed upon mixing (300 rpm), as a result of which a temperature of the reaction mass rises from 20 C. to 42 C., then the reaction mass is thermostated at 50 C. and butadiene (15.146 g) is fed, the mixing (300 rpm) is continued for one hour at temperature of 50-60 C. Thereafter, the THF is distilled under vacuum. The distillation is continued until the refractive index of the distilled liquid will be equal to the refractive index of styrene, namely 1.4969 at the temperature of 20 C. The remaining initiator solution is titrated by the solution of isopropanol in toluene, as a result of which the concentration of initiator equal to 0.32 mole/ll is reached. The obtained initiator is used in reactor syntheses: Molecular weight characteristics of the obtained initiator are presented below.

TABLE-US-00001 Number-average Weight-average Average molecular weight molecular weight Density molecular weight M.sub.n M.sub.w PD M.sub.z 705 758 1.08 816

[0161] Example 1. Polymerization with the Use of the Preliminary Obtained Functionalizing Lithium Initiator Pir-(Bd).sub.t-Li, the Polar Comonomerbis(dimethylamino)vinylmethylsilane (BDAS) and the Polyfunctional Silicon-Containing AgentCoatosil MP 200

[0162] The process of producing butadiene-styrene rubbers is carried out in the reactor of the firm Buchi with a metal cup having the useful capacity of 2 L supplied with the mixer, thermostating jacket, connection pipes and special removable metal dispensers for feeding reagents.

[0163] Petroleum solvent (984 g), butadiene (92.62 g), styrene (33.57 g) and 1 M of the BDAS solution in the petroleum solvent (0.32 ml) and 2.0 ml of the DTHFP solution in the petroleum solvent (0.32 M solution) are fed to the reactor cooled to (20) C. (2 C.) in the nitrogen stream at the mixer rotation speed of 50 rpm. Thereafter the rotation speed of the mixer equal to 300 rpm is fixed, after which the temperature of the reaction mass is increased up to 55 C. with the heating rate of 7 K/min; when the temperature amounts to 55 C., 3.9 ml of the initiator solution (0.32 M solution) is fed. When the required conversion degree of monomers (100%) is reached, the portion of the polymer is taken away for the analysis of microstructural and molecular properties of the rubber. Then the reaction mass is heated up to 80 C. and the polyfunctional silicon-containing agentCoatosil MP 200 is fed in an amount of 0.2 wt. % based on the rubber. The modification process is carried out at the temperature 80 C. for 30 minutes. After this, a polymerizate is poured out to a beaker and is filled with the antioxidant Novantox (0.4 wt. % based on the polymer). Then the aqueous degassing of the rubber is carried out in the oil bath at the temperature of 150 C. The obtained rubber containing water is dried on rolls at the temperature of 85 C.

[0164] Properties of the obtained rubber are presented in Table 1.

[0165] Example 2. Polymerization with the Use of the Preliminary Obtained Functionalizing Lithium Initiator Pir-(Bd)t-Li, the Polar ComonomerBDAS and the Polyfunctional Silicon-Containing AgentCoatosil MP 200

[0166] The process of producing butadiene-styrene rubbers is carried out according to the procedure described in example 1, except that 0.64 ml of 1M BDAS solution in the petroleum solvent is used (the amount of the polar comonomerthe BDASis two times greater).

[0167] Properties of the obtained rubber are presented in Table 1.

[0168] Example 3. Polymerization with the Use of Functionalizing Lithium Initiator Pyrrolidine+BuLi Obtained in the Reaction Mixture, the Polar ComonomerBDAS and the Polyfunctional Silicon-Containing AgentCoatosil MP 200

[0169] The process of producing butadiene-styrene rubbers is carried out in the reactor of the firm Buchi with a metal cup having the useful capacity of 2 L supplied with the mixer, thermostating jacket, connection pipes and special removable metal dispensers for feeding reagents.

[0170] Petroleum solvent (987 g), butadiene (91.92 g), styrene (35.75 g) and 4.0 ml of the DTHFP solution in the petroleum solvent (0.32 M solution), 1 M of the BDAS solution in the petroleum solvent (0.62 ml) and a pyrrolidine solution in the petroleum solvent (5.9 ml, 0.2 M) are fed to the reactor cooled to (20) C. (2 C.) in the nitrogen stream at the mixer rotation speed of 50 rpm. Thereafter the rotation speed of the mixer equal to 300 rpm is fixed, after which the temperature of the reaction mass is increased up to 55 C. with the heating rate of 7 K/min; when the temperature amounts to 55 C., 4.0 ml of the n-butyl lithium solution in the petroleum solvent (0.32 M solution) is fed. When the required conversion degree of monomers (100%) is reached, the portion of the polymer is taken away for the analysis of microstructural and molecular properties of the rubber. Then the reaction mass is heated up to 80 C. and the polyfunctional silicon-containing agentCoatosil MP 200 is fed in an amount of 0.3 wt. % based on the rubber. The modification process is carried out at the temperature of 80 C. for 30 minutes. After this, a polymerizate is poured out to a beaker and is filled with the antioxidant Novantox (0.4 wt. % based on the polymer). Then the aqueous degassing of the rubber is carried out in the oil bath at the temperature of 150 C. The obtained rubber containing water is dried on rolls at the temperature of 85 C.

[0171] Properties of the obtained rubber are presented in Table 1.

[0172] Example 4. Polymerization with the Use of the Preliminary Obtained Functionalizing Lithium Initiator Pir-(Bd).sub.t-Li, the Polar ComonomerBDAS and the Polyfunctional Silicon-Containing AgentCoatosil MP 200

[0173] The process of producing butadiene-styrene rubbers is carried out according to the procedure described in example 1, except that 0.64 ml of 1M BDAS solution (the amount of the polar comonomerthe BDASis two times greater) and 0.3 wt. % based on the total amount of monomers of the polyfunctional silicon-containing agentCoatosil MP200 (half as much again) are used.

[0174] Properties of the obtained rubber are presented in Table 1.

[0175] Example 5. Polymerization with the Use of the Functionalizing Lithium Initiator Pyrrolidine+BuLi Obtained in the Reaction Mixture, the Polar ComonomerBDAS and the Polyfunctional Silicon-Containing AgentCoatosil MP 200

[0176] The process of producing butadiene-styrene rubbers is carried out according to the procedure described in example 3, except that 0.64 ml of 1M BDAS solution in the petroleum solvent is used (the amount of the polar comonomerthe BDASis two times greater).

[0177] Properties of the obtained rubber are presented in Table 1.

[0178] Example 6. Polymerization with the Use of the Preliminary Obtained Functionalizing Lithium Initiator Pir-(Bd)t-Li, the Polar ComonomerBDAS and the Polyfunctional Silicon-Containing AgentCoatosil MP 200

[0179] The process of producing butadiene-styrene rubbers is carried out according to the procedure described in example 1, except that 1.28 ml of 1M BDAS solution in the petroleum solvent (the amount of the polar comonomerthe BDASis four times greater) and 0.3 wt. % based on the total amount of monomers of the polyfunctional silicon-containing agentCoatosil MP200 (1,5 times greater) are used.

[0180] Properties of the obtained rubber are presented in Table 1.

[0181] Example 7. Polymerization with the Use of the Preliminary Obtained Functionalizing Lithium Initiator Pir-(Bd)t-Li and the Polyfunctional Silicon-Containing AgentCoatosil MP 200

[0182] The process of producing butadiene-styrene rubbers is carried out according to the procedure described in example 1, except that 0.3 wt. % of the polyfunctional silicon-containing agent Coatosil MP200 based on the total amount of monomers (1.5 times greater) is used, and that the polar comonomer is not used.

[0183] Properties of the obtained rubber are presented in Table 1.

[0184] Example 8. Polymerization with the Use of the Functionalizing Lithium Initiator Pyrrolidine+BuLi Obtained in the Reaction Mixture and the Polyfunctional Silicon-Containing AgentCoatosil MP 200

[0185] The process of producing butadiene-styrene rubbers is carried out according to the procedure described in example 3, except that the polar comonomer is not used.

[0186] Properties of the obtained rubber are presented in Table 1.

[0187] Example 9. Polymerization in the Presence of n-butyl Lithium (Comparative)

[0188] The process of producing butadiene-styrene rubbers is carried out in the reactor of the firm Buchi with a metal cup having the useful capacity of 2 L supplied with the mixer, thermostating jacket, connection pipes and special removable metal dispensers for feeding reagents.

[0189] Petroleum solvent (990 g), butadiene (93.00 g), styrene (31.00 g) and 1.65 ml of the DTHFP solution in the petroleum solvent (0.32 M solution) are fed to the reactor cooled to (20) C. (2 C.) in the nitrogen stream at the mixer rotation speed of 50 rpm. Thereafter the rotation speed of the mixer equal to 300 rpm is fixed, after which the temperature of the reaction mass is increased up to 55 C. with the heating rate of 7 K/min; when the temperature amounts to 55 C., 3.3 ml of the n-butyl lithium solution in petroleum solvent (0.32 M solution) is fed. When the required conversion degree of monomers (100%) is reached, the polymer is poured out to the beaker and is filled with the antioxidant Novantox (0.4 wt. % based on the polymer). Then the aqueous degassing of the rubber is carried out in the oil bath at the temperature of 150 C. The obtained rubber containing water is dried on rolls at the temperature of 85 C.

[0190] Properties of the obtained rubber are presented in Table 1.

[0191] Example 10. Commercially Available Rubber

[0192] Properties of the commercially available rubber that is branched and functionalized are presented in Table 1.

TABLE-US-00002 TABLE 1 Properties of rubbers described in examples 1-12 A process of DTHFP/ BDAS, % Coatosil, NMR 1H MWD Example producing the Initiator wt. % per wt. % per St, 1,2-Bd*, M.sub.n 10.sup.3, M.sub.z 10.sup.3, Mooney No initiator Initiator ratio rubber rubber wt. % wt. % g/mole M.sub.w/M.sub.n g/mole viscosity 1 Preliminary Pir-(Bd).sub.t-Li 1/2 0.04 0.2 26.35 59.80 130 1.33 228 26.40 59.89 170 1.96 551 57 2 Preliminary Pir-(Bd).sub.t-Li 1/2 0.08 0.2 26.70 60.10 129 1.32 221 26.74 60.16 145 2.16 571 57 3 In the reaction Pyrrolidine + 1/2 0.08 0.3 26.88 58.15 149 1.43 308 mixture (in situ) BuLi 26.91 58.08 196 1.87 575 61 4 Preliminary Pir-(Bd).sub.t-Li 1/2 0.08 0.3 28.09 59.13 167 1.68 485 28.01 59.01 167 1.91 621 60 5 In the reaction Pyrrolidine + 1/2 0.16 0.3 28.41 57.25 145 1.72 452 mixture (in situ) BuLi 28.35 57.17 153 1.97 577 62 6 Preliminary Pir-(Bd).sub.t-Li 1/2 0.16 0.3 26.75 59.12 131 1.34 257 26.69 59.02 185 1.85 527 60 7 Preliminary Pir-(Bd).sub.t-Li 1/2 0.3 27.92 57.71 150 1.33 264 27.94 57.79 195 1.84 558 58 8 In the reaction Pyrrolidine + 1/2 0.3 27.61 56.41 128 1.37 222 mixture (in situ) BuLi 27.66 56.35 189 1.79 500 69 9 BuLi 1/2 26.44 60.20 180 1.21 263 49 10 no data about conditions of the synthesis and modification 19.30 63.30 133 1.80 432 58 *based on the butadiene portion of the polymer Pir-(Bd)t-Lifunctionalizing lithium initiator preliminary obtained Pyrrolidine + BuLifunctionalizing lithium initiator obtained in the reaction mixture BDASbis(dimethylamino)vinylmethylsilane Coatosilpolyfunctional end modifier- oligosiloxane.

[0193] Example 11. Tests of the Rubbers Described in Examples 1-10 in the Formulations of Rubber Compositions

[0194] The tests of the rubbers described in examples 1-8 and comparative samples (examples 9-10) were carried out in the rubber composition for passenger-car tire tread. The recipe of the rubber composition is presented in Table 2. The manufacture of the rubber compositions was carried out using the plasticorder Plastograph ECPlus, Model 2008 of the firm Brabender (Germany). The free volume of the mixing chamber with N 50 EHT type cam rotors was 80 cm.sup.3. The mixing was carried out in three steps: the 1.sup.st stepmixing all ingredients except for the vulcanizing group, i.e. sulfur, MBT, DPG, SAC); the initial temperature of chamber walls is 130 C., the maximal temperature in the chamber during the mixing processnot more than 160 C., the rotation speed of rotors is 40-60 rpm; the 2.sup.nd stepdispersing mixing the mixture of the step 1 without the addition of further ingredients; the initial temperature of chamber walls is 80 C., the maximal temperaturenot more than 130 C., the rotation speed of rotors is 60 rpm; the 3.sup.rd stepadministering the vulcanizing group to the rubber composition; the initial temperature of chamber walls is 80 C., the maximal temperaturenot more than 110 C., the rotation speed of rotors is 40 rpm.

TABLE-US-00003 TABLE 2 Formulation of the rubber compositions Content, weight parts per 100 weight parts Names of ingredients of the rubber Natural rubber TSR RSS-1 30.0 Solution butadiene-styrene rubber according 70.0 to examples 1-9 Carbon black N 339 (Yaroslavskiy factory of 13.0 carbon black) Precipitated colloidal silica Zeosil 1165 86.0 MP (Solvay) Plasticizer Vivatec 200 (Hansen&Rosental) 50.0 Plasticizer rapeseed oil (technical) 8.0 (Profet, LLC) Antiageing retardant 6PPD (EastmanSantoflex) 2.5 Antiageing retardant TMQ (Chemtura) 2.0 Protective wax Antilux 111 (RheinChemie) 2.0 Zinc oxide (Empils, LLC) 2.0 Stearic acid (Nefis Cosmetics, JSC) 1.0 Technological additive ActiplastST 4.0 (RheinChemie) Silanizing agent Si-69 (Evonic) 8.0 Mercaptobenzothiazole (MBT-2) (Stair, China) 0.1 Diphenylguanidine (DPG) (RheinChemie) 2.0 Sulfenamide C (SAC) (Lanxess) 2.0 Milled sulfur, technical 9998 (Oil company 1.7 Lukoil)
The preparation of rubber compositions for vulcanization, the vulcanization and preparation of samples for tests were carried out in accordance with ASTM D 3182. Modes of vulcanization: 160 C. for 20 min to assess the deformation-strength properties and for 30 min to assess the hardness and abradability. The assessment of the main properties of vulcanizates upon tension (f.sub.300-the conventional stress upon the 300% elongation, f.sub.r-modulus of rupture, .sub.rel-breaking elongation) was carried out according to ASTM D 412-98, of Shore D hardness (H)according to National State Standard 263-75. The Shopper-Schlobach abradability (ABR) (method B) was assessed in accordance with National State Standard 23509-79. Hysteresis properties (tg-mechanical loss tangent) were determined with the use of DMA 242 C apparatus (NETZSCH) and RPA-2000 apparatus (Alpha Technology). Conditions of tests on the DMA 242 C: two arm bend, sizes of the sample10.006.502.0 mm, amplitude 40 m (1%), frequency10 Hz, load7 N. The temperature range for the test is from (60) C. to (+60) C., the temperature increase rate is 2/min. Conditions of tests on the RPA-2000: shift, amplitude10%, frequency10 Hz, the temperature is 60 C.

[0195] Vulcanizing characteristics: t.sub.s1the starting time of vulcanization, t.sub.50time to 50% vulcanization degree, t.sub.90optimal time of vulcanization, M.sub.Hmaximum torque, M.sub.Lminimum torque, were assessed with the use of RPA 2000 apparatus at 160 C. for 30 min and frequency 1.7 Hz, in accordance with ASTM D 5289-07.

[0196] Table 3 comprises vulcanizing, physical-mechanical and hysteresis properties of rubber compositions and vulcanizates comprising rubbers described in examples 1-10.

TABLE-US-00004 TABLE 3 Properties of rubber compositions and vulcanizates Code and description of the sample Sample 1 Sample 2 Sample 3 Sample 4 Sample 5 Sample 6 Pir-(Bd).sub.t- Pir-(Bd).sub.t- Pir-Li (in Pir-(Bd).sub.t- Pir-Li (in Pir-(Bd).sub.t- Sample 7 Sample 8 Sample 9 Sample 10 Li; BDAS- Li; BDAS - situ); BDAS Li; BDAS situ); BDAS Li; BDAS Pir-(Bd).sub.t- Pir-Li Non- Commer- 0.04; 0.08; 0.08; 0.08; 0.16; 0.16; Li; (in situ); function- cially Coatosil Coatosil Coatosil Coatosil Coatosil Coatosil Coatosil Coatosil alized available Index 0.2 0.2 0.3 0.3 0.3 0.3 0.3 0.3 rubber rubber Vulcanizing characteristics (RPA-2000, 160 C. 30 min) t.sub.s1, min 1.7 1.7 1.9 1.9 1.5 1.6 1.5 1.6 1.8 1.9 t.sub.10, min 1.9 1.9 2.3 2.2 1.7 1.7 1.8 1.8 2.0 2.2 t.sub.50, min 3.4 3.5 3.5 3.4 2.8 3.3 2.9 3.0 3.1 3.4 t.sub.90, min 15.8 15.9 15.9 16.0 14.8 15.0 9.7 10.2 7.9 11.4 M.sub.H M.sub.L, dNm 17.0 16.4 16.9 17.3 16.7 17.2 17.5 17.0 15.5 15.8 Physical and mechanical properties of vulcanizates f.sub.300, MPa 11.4 12.0 11.5 11.1 12.0 11.8 11.4 11.2 8.6 10.4 f.sub.r, MPa 17.4 17.5 17.6 17.5 17.7 17.6 17.1 17.0 15.3 16.2 E.sub.rel, % 430 410 460 470 450 430 430 450 500 470 H, Shore A 59 57 59 59 60 61 62 60 62 60 ABR, mm.sup.3 170 172 173 167 179 181 169 169 184 173 Hysteresis properties tg (0 C.)* 0.417 0.467 0.453 0.419 0.419 0.430 0.401 0.369 0.349 0.366 tg (60 C.)* 0.164 0.148 0.139 0.140 0.140 0.130 0.155 0.154 0.194 0.162 tg (60 C.)** 0.125 0.122 0.118 0.117 0.123 0.122 0.144 0.148 0.148 0.133 Alteration in hysteresis properties (in %) with respect to example 9*** tg (0 C.)* 119 130 134 120 120 123 115 106 100 105 tg (60 C.)* 115 124 128 128 128 133 120 121 100 116 tg (60 C.)** 116 118 120 121 117 118 103 100 100 110 ABR, mm.sup.3 108 107 106 109 103 104 108 108 100 106 Comments: *DMA 242 C (1%, 10 Hz); **RPA-2000 (10%, 10 Hz, shift); ***values greater than 100 show the improvement of the index, less than 100 - worsening. Pir-Lifunctionalizing lithium initiator obtained in the reaction mixture Pir-(Bd).sub.t-Lifunctionalizing lithium initiator preliminary obtained BDASbis(dimethylamino)vinylmethylsilane, Coatosil 0.3polyfunctional end modifier - oligosiloxane. t.sub.s1the starting time of vulcanization, t.sub.50time to 50% vulcanization degree, t.sub.90optimal time of vulcanization, M.sub.Hmaximum torque, M.sub.Lminimum torque, f.sub.300the conventional stress upon the 300% elongation, f.sub.rmodulus of rupture, .sub.relbreaking elongation, H, ShoreShore hardness, ABRShopper-Schlobach abradability, tgmechanical loss tangent.

[0197] It is an object of the present invention to create rubbers capable of improving hysteresis properties of rubber compositions and vulcanizates comprising them, namely lower hysteresis loss at 60 C. and increase them at 0 C.

[0198] The hysteresis loss was assessed according to the mechanical loss tangent (tg) at temperatures0 C. and 60 C. and strain amplitudes1 and 10%.

[0199] The hysteresis properties determined at the temperature of 60 C. in case of tire tread rubbers characterize the rolling loss and, as a consequence, the economy of fuel of the automobile in the whole. Otherwise, for example, for industrial rubber articles of different purpose, this index may indicate the hysteresis loss level in the vulcanizates under dynamic operating conditions.

[0200] The index tg at temperature 0 C. is of interest for tread rubbers and characterizes their road grip properties. The improvement of road grip properties of the tread is observed upon the increased levels of tg at 0 C.

[0201] Rubbers obtained according to the invention (examples 1-6), due to the functionalization at the beginning of chain, using the functionalizing initiator, the modification at the end of chain, using the silicon-containing agent and the functionalization along the chain by means of inclusion of the polar comonomer, increase in the affinity and interaction between the rubber and filler, due to which vulcanizates comprising the rubbers according to examples 1-6 have 19-34% better tg at 0 C. in comparison with the vulcanizates comprising non-modified rubber (example 9) and 4-15% better tg at 0 C. in comparison with vulcanizates comprising rubbers with double functionalization at the beginning and at the end of chain (examples 7, 8) and 13-27% better tg at 0 C. in comparison with the commercially available rubber (example 10)(Table 3).

[0202] It follows from data of Table 3 that, in accordance with the invention, the simultaneous use for the rubber modification of the functionalized comonomer (BDAS) providing the functionalization along a polymer chain, the functionalizing initiator that is preliminary obtained or is obtained in the reaction mixture (according to the examples under the consideration, the functionalizing initiator is obtained upon the reaction of pyrrolidine with butyl lithium and butadiene) which provides the functionalization of the polymer chain at the beginning thereof, and a polyfunctional end modifieroligosiloxane (according to the examples under considerationthis is Coatosil MP 200), providing the branchingmodification at the ends of chains, results in lowering values of the index tg at 60 C. of the vulcanizates. Thus, the rubbers obtained according to the invention (examples 1-6) provide lowering the hysteresis loss of vulcanizates at 60 C., assessed upon 1% and/or 10% amplitude of the dynamic deformation, as compared to the unmodified rubber (example 9) by 15-33%, as compared to the rubbers with double functionalization at the beginning and at the end of chain (examples 7, 8)by 8-20%.

[0203] Thus, the proposed approach to the modification provides the necessary set of functional groups in the rubber, which has the greater advantageous influence on the compatibility of the rubber and filler in a rubber composition and, as a consequence, results in the significant lowering of hysteresis loss at 60 C. of vulcanizates produced on the basis of such rubber composition.

[0204] As regards the influence on the abradability of rubber compositions, the rubbers obtained according to the invention are at the level of comparison samples described in examples 7, 8, 10 and surpass the unmodified rubber (example 9).

[0205] The observed changes of vulcanizing properties of rubber compositions and deformation-strength properties of vulcanizates (see Table 3) do not limit the possibility of using the rubbers obtained in accordance with the invention according to the specific purpose, but should be taken by the skilled person into account upon the development of formulations of the rubber compositions comprising them.