Rubber composition for tire and tire

Abstract

The present invention addresses the problem of providing a rubber composition for tires capable of providing a good balance between processability and low fuel consumption and wear resistance when applied to tires. The means for solving this problem is a rubber composition for tires characterized by comprising a rubber component and a filler, in which the rubber component comprises: a polymer of cyclopentene and a norbornene-based compound represented by general formula (1) [in the formula, R1-R4 each independently represent a hydrogen atom, a C1-20 hydrocarbon group, a C1-20 hydrocarbon group, a C1-20 hydrocarbon group, a C1-20 hydrocarbon group, a C1-20 hydrocarbon group, a C1-20 hydrocarbon group, a C1-20 hydrocarbon group, a C1-20 hydrocarbon group, and a C1-20 hydrocarbon group; or a substituent comprising a halogen atom, a silicon atom, an oxygen atom, or a nitrogen atom; r2 and R3 may be bonded to each other to form a ring; and m is an integer of 0-2]; and a modified polymer. .

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a rubber composition for tires and a tire. BACKGROUND

[0002] In connection with a global movement to regulate carbon dioxide emissions due to a high level of concern about environmental problems in recent years, the demand for improvement in fuel efficiency of motor vehicles is increasing. In order to meet this demand, improvement in tire performance, particularly, improvement in high fuel efficiency (i.e., reduction in rolling resistance) is also required.

[0003] Furthermore, from the viewpoint of tire economy, in the development of a rubber composition for tires, not only high fuel efficiency but also improvement in wear resistance is required.

[0004] However, generally, high fuel efficiency and wear resistance are in a trade-off relationship, and it is difficult to achieve both at the same time. For example, a method in which the amount of filler is increased to improve wear resistance is known, but increasing the amount of filler leads to a problem in that the dispersion state of the filler deteriorates, thereby causing deterioration in high fuel efficiency. Furthermore, there is also a problem in that the unvulcanized viscosity of the rubber composition increases, thereby causing deterioration in processability. Therefore, generally, it is difficult to achieve a good balance among high fuel efficiency, wear resistance, and processability.

[0005] In correspondence thereto, Patent Literature 1 and Patent Literature 2 below disclose a rubber composition for passenger car tires and a rubber composition for heavy truck and bus tires, which contain a specific long-chain branched cyclopentene ring-opening rubber (LCB-CPR). These rubber compositions are considered to be effective in reducing the rolling resistance of a tire, improving wet skid resistance, and improving wear resistance.

[0006] PRIOR ART DOCUMENTS

[0007] PATENT LITERATURE

[0008] Patent Literature 1: WO 2021 / 178233 A1

[0009] Patent Literature 2: WO 2021 / 178235 A1 SUMMARY

[0010] PROBLEMS TO BE SOLVED BY THE INVENTION

[0011] However, as a result of the present inventors’ studies, it was found that even with the techniques described in Patent Literature 1 and Patent Literature 2 above, it is difficult to achieve a good balance between processability of a rubber composition and both high fuel efficiency and wear resistance of a tire to which the rubber composition is applied, and there is still room for improvement.

[0012] Accordingly, an object of the present disclosure is to solve the above-described problems of the prior art and to provide a rubber composition for tires that can achieve a good balance between processability and both high fuel efficiency and wear resistance of a tire when applied to the tire.

[0013] Further, another object of the present disclosure is to provide a tire that achieves a good balance between high fuel efficiency, wear resistance, and productivity.

[0014] Approach for solving the problem

[0015] The basic configuration of the rubber composition for tires and the tire of the present disclosure for solving the above-described problems is as follows.

[0016] [1] A rubber composition for tires comprising a rubber component and a filler,

[0017] wherein the rubber component comprises:

[0018] a copolymer of cyclopentene and a norbornene-based compound represented by general formula (1) shown below:

[0019] [Chemical Formula 1]

[0020] ,

[0021] wherein, in general formula (1), R 1 to R 4 each independently represent a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a substituent containing a halogen atom, a silicon atom, an oxygen atom, or a nitrogen atom, R 2 and R 3 may be bonded to each other to form a ring, and m is an integer of 0 to 2; and

[0022] a modified polymer.

[0023] [2] The rubber composition for tires according to [1], wherein the norbornene-based compound represented by general formula (1) is 2-norbornene and / or dicyclopentadiene.

[0024] [3] The rubber composition for tires according to [1] or [2], wherein the content of the copolymer of cyclopentene and the norbornene-based compound is 20 to 90 parts by mass per 100 parts by mass of the rubber component.

[0025] [4] The rubber composition for tires according to any one of [1] to [3], wherein the weight average molecular weight (Mw) of the copolymer of cyclopentene and the norbornene-based compound is 200,000 to 1,000,000.

[0026] [5] The rubber composition for tires according to any one of [1] to [4], wherein the content ratio of the structural unit derived from cyclopentene of the copolymer of cyclopentene and norbornene-based compound is 20 to 75 mass%.

[0027] [6] The rubber composition for tires according to any one of [2] to [5], wherein the content ratio of the structural unit derived from 2-norbornene of the copolymer of cyclopentene and norbornene-based compound is 10 to 60 mass%.

[0028] [7] The rubber composition for tires according to any one of [2] to [6], wherein the content ratio of the structural unit derived from dicyclopentadiene of the copolymer of cyclopentene and norbornene-based compound is 10 to 60 mass%.

[0029] [8] The rubber composition for tires according to any one of [1] to [7], wherein the content of the modified polymer is 5 to 90 parts by mass per 100 parts by mass of the rubber component.

[0030] [9] The rubber composition for tires according to any one of [1] to [8], wherein the modified polymer has a nitrogen-containing functional group.

[0031]

[10] The rubber composition for tires according to any one of [1] to [9], wherein the modified polymer is a modified butadiene rubber or a modified styrene-butadiene rubber.

[0032]

[11] The rubber composition for tires according to any one of [1] to

[10] , wherein the modified polymer is a modified butadiene rubber.

[0033]

[12] The rubber composition for tires according to any one of [1] to

[11] , wherein the filler comprises carbon black.

[0034]

[13] A tire comprising the rubber composition for tires according to any one of [1] to

[12] .

[0035] Effects of the Invention

[0036] According to the present disclosure, it is possible to provide a rubber composition for tires that can achieve a good balance between processability and both high fuel efficiency and wear resistance of a tire when applied to the tire.

[0037] Further, according to the present disclosure, it is possible to provide a tire that achieves a good balance between high fuel efficiency, wear resistance, and productivity. DETAILED DESCRIPTION

[0038] Hereinafter, the rubber composition for tires and the tire of the present disclosure will be exemplified and described in detail on the basis of embodiments thereof.

[0039] <Definitions>

[0040] The compounds described in the present specification can be derived in part or in whole from fossil resources, can be derived from biological resources such as plant resources, or can be derived from recycled resources such as waste tires. Furthermore, they can be derived from a mixture of any two or more of fossil resources, biological resources, and recycled resources.

[0041] <Rubber composition for tire>

[0042] The rubber composition for tire of the present embodiment contains a rubber component and a filler. In the rubber composition for tire of the present embodiment, the rubber component contains:

[0043] a copolymer of cyclopentene and a norbornene-based compound represented by the following general formula (1) (hereinafter also simply referred to as "copolymer of cyclopentene and norbornene-based compound" or "copolymer"):

[0044] [Chemical 2]

[0045]

[0046] [in the formula, R 1 to R 4 each independently represent a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a substituent containing a halogen atom, a silicon atom, an oxygen atom, or a nitrogen atom; R 2 and R 3 may be bonded to each other to form a ring; and m is an integer of 0 to 2]; and

[0047] a modified polymer (hereinafter also simply referred to as "modified polymer").

[0048] In the rubber composition for tire of the present embodiment, the copolymer of cyclopentene and norbornene-based compound is characterized not only by having crosslinking points but also by entanglement between polymer chains.

[0049] Generally, when a filler is blended into a rubber component, a reinforcing layer composed of the filler and the rubber component is formed around the filler, and this reinforcing layer contributes to improvement in reinforcing property of the rubber composition, thereby improving wear resistance and the like.

[0050] On the contrary, in the rubber composition for tire of the present embodiment, since the rubber component contains the copolymer of cyclopentene and norbornene-based compound, the reinforcing layer formed around the filler is particularly increased due to the entanglement between the above-described polymer chains, and thus wear resistance can be sufficiently improved.

[0051] ​Further, in the rubber composition for tires of the present embodiment, since the rubber component contains the modified polymer, and the modified polymer has high affinity with the filler and can improve dispersibility of the filler, high fuel efficiency, wear resistance, and processability of the rubber composition can be improved.

[0052] Therefore, the rubber composition for tires of the present embodiment can achieve a good balance between processability and both high fuel efficiency and wear resistance when applied to tires.

[0053] (Rubber component)

[0054] The rubber composition for tires of the present embodiment contains a rubber component, and the rubber component imparts rubber elasticity to the composition. The rubber component of the rubber composition for tires of the present embodiment contains a copolymer of a cyclopentene and norbornene-based compound represented by the above general formula (1) and a modified polymer, and can further contain other rubbers.

[0055] -Copolymer of a cyclopentene and norbornene-based compound-

[0056] The copolymer of a cyclopentene and norbornene-based compound contains a structural unit derived from a cyclopentene and a structural unit derived from a norbornene-based compound represented by the above general formula (1). In a preferred embodiment, the copolymer of a cyclopentene and norbornene-based compound is a ring-opening copolymer, particularly a cyclopentene ring-opening copolymer.

[0057] In the above general formula (1), R 1 to R 4 each independently represents a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a substituent containing a halogen atom, a silicon atom, an oxygen atom, or a nitrogen atom; R 2 and R 3 may be bonded to each other to form a ring; and m is an integer of 0 to 2. Here, examples of the hydrocarbon group having 1 to 20 carbon atoms include: alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, neopentyl, hexyl, and octyl, and the like; alkenyl groups such as vinyl, allyl, 2-pentenyl, 3-pentenyl, and 4-methyl-3-pentenyl, and the like; aryl groups such as phenyl, tolyl, 2,6-dimethylphenyl, 2,6-diisopropylphenyl, and naphthyl, and the like; and aralkyl groups such as benzyl and phenethyl, and the like.

[0058] Examples of the norbornene-based compound represented by the above general formula (1) include:

[0059] unsubstituted or hydrocarbyl-substituted bicyclo[2.2.1]hept-2-enes such as 2- norbornene, 5-methyl-2-norbornene, 5-ethyl-2-norbornene, 5-butyl-2-norbornene, 5- hexyl-2-norbornene, 5-decyl-2-norbornene, 5-cyclohexyl-2-norbornene, 5- cyclopentyl-2-norbornene, 5-ethylidene-2-norbornene, 5-vinyl-2-norbornene, 5- propenyl-2-norbornene, 5-cyclohexenyl-2-norbornene, 5-cyclopentenyl-2-norbornene, 5-phenyl-2-norbornene, tetracyclo[9.2.1.0 2,10 .0 3,8 ]tetradeca-3,5,7,12-tetraene (also known as "1,4-methano-1,4,4a,9a-tetrahydro- 9H-fluorene"), tetracyclo[10.2.1.0 2,11 .0 4,9 ]pentadeca-4,6,8,13-tetraene (also known as "1,4-methano-1,4,4a,9,9a,10- hexahydroanthracene"), dicyclopentadiene, methyl dicyclopentadiene, and dihydrodicyclopentadiene (also known as "tricyclo[5.2.1.0 2,6 ]dec-8-ene"), and the like;

[0060] unsubstituted or hydrocarbyl-substituted tetracyclo[6.2.1.1 3,6 .0 2,7 ]dodeca-4-enes such as tetracyclo[6.2.1.1 3,6 .0 2 ,7 ]dodeca-4-ene, 9-methyltetracyclo[6.2.1.1 3,6 .0 2,7 ]dodeca-4-ene, 9-ethyltetracyclo[6.2.1.1 3,6 .0 2,7 ]dodeca-4-ene, 9-cyclohexyltetracyclo[6.2.1.1 3,6 .0 2,7 ]dodeca-4-ene, 9-cyclopentyltetracyclo[6.2.1.1 3,6 .0 2 ,7 ]dodeca-4-ene, 9-methylenetetracyclo[6.2.1.1 3,6 .0 2,7 ]dodeca-4-ene, 9-ethylidene tetracyclo[6.2.1.1 3, 6 .0 2,7 ]dodeca-4-ene, 9-vinyltetracyclo[6.2.1.1 3,6 .0 2,7 ]dodeca-4-ene, 9-propenyltetracyclo[6.2.1.1 3,6 .02,7 ]dodeca-4-ene, 9-cyclohexenyltetracyclo[6.2.1.1 3,6 .0 2,7 ]dodeca-4-ene, 9-cyclopentenyltetracyclo[6.2.1.1 3,6 .0 2,7 ]dodeca-4-ene and 9-phenyltetracyclo[6.2.1.1 3,6 .0 2,7 ]dodeca-4-ene, and the like;

[0061] Bicyclo[2.2.1]hept-2-ene derivatives having an alkoxycarbonyl group, such as 5-norbornene-2-carboxylic acid methyl ester, 5-norbornene-2-carboxylic acid ethyl ester, 2-methyl-5-norbornene-2-carboxylic acid methyl ester, and 2-methyl-5-norbornene-2-carboxylic acid ethyl ester, and the like;

[0062] Tetracyclo[6.2.1.1 3,6 .0 2,7 ]dodeca-4-ene derivatives, such as tetracyclo[6.2.1.1 3,6 .0 2 ,7 ]dodeca-9-ene-4-carboxylic acid methyl ester, and 4-methyltetracyclo[6.2.1.1 3,6 .0 2,7 ]dodeca-9-ene-4-carboxylic acid methyl ester, and the like;

[0063] Bicyclo[2.2.1]hept-2-ene derivatives having a hydroxycarbonyl group or an anhydride group, such as 5-norbornene-2-carboxylic acid, 5-norbornene-2,3-dicarboxylic acid, and 5-norbornene-2,3-dicarboxylic anhydride, and the like;

[0064] Tetracyclo[6.2.1.1 3,6 .0 2,7 ]dodeca-4-ene derivatives, such as tetracyclo[6.2.1.1 3,6 .0 2,7 ]dodeca-9-ene-4-carboxylic acid, tetracyclo[6.2.1.1 3,6 .0 2,7 ]dodeca-9-ene-4,5-dicarboxylic acid, and tetracyclo[6.2.1.1 3,6 .0 2,7 ]dodeca-9-ene-4,5-dicarboxylic anhydride, and the like;

[0065] Bicyclo[2.2.1]hept-2-ene derivatives having a hydroxyl group, such as 5-hydroxy-2- norbornene, 5-hydroxymethyl-2-norbornene, 5,6-di(hydroxymethyl)-2-norbornene, 5,5- di(hydroxymethyl)-2-norbornene, 5-(2-hydroxyethoxycarbonyl)-2-norbornene, 5-methyl- 5-(2-hydroxyethoxycarbonyl)-2-norbornene, and the like;

[0066] Tetracyclo[6.2.1.1 3,6 .0 2,7 ]dodec-4-ene derivatives having a hydroxyl group, such as tetracyclo[6.2.1.1 3,6 .0 2,7 ]dodec-9-en-4-methanol, tetracyclo[6.2.1.1 3,6 .0 2,7 ]dodec-9-en-4-ol, and the like;

[0067] Bicyclo[2.2.1]hept-2-ene derivatives having a hydrocarbonyl group, such as 5- norbornene-2-carboxaldehyde, and the like;

[0068] Tetracyclo[6.2.1.1 3,6 .0 2,7 ]dodec-4-ene derivatives having a hydrocarbonyl group, such as tetracyclo[6.2.1.1 3,6 .0 2,7 ]dodec-9-en-4-carboxaldehyde, and the like;

[0069] Bicyclo[2.2.1]hept-2-ene derivatives having both an alkoxycarbonyl group and a hydroxycarbonyl group, such as 3-methoxycarbonyl-5-norbornene-2-carboxylic acid, and the like;

[0070] Bicyclo[2.2.1]hept-2-ene derivatives having a carbonyloxy group, such as 5-norbornene-2-yl acetate, 2-methyl-5-norbornene-2-yl acetate, 5-norbornene-2-yl acrylate, 5- norbornene-2-yl methacrylate, and the like;

[0071] Tetracyclo[6.2.1.1 3,6 .0 2,7 ]dodec-4-ene derivatives having a carbonyloxy group, such as 9-tetracyclo[6.2.1.1 3,6 .0 2 ,7 ]dodec-4-en-yl acetate, 9-tetracyclo[6.2.1.1 3,6 .0 2,7 ]dodec-4-en-yl acrylate, and 9-tetracyclo[6.2.1.1 3,6 .0 2,7 ]dodec-4-en-yl methacrylate, and the like;

[0072] Bicyclic [2.2.1]hept-2-enes with nitrogen-containing functional groups, such as 5-norbornene-2-carboxynitrile, 5-norbornene-2-carboxamide, and 5-norbornene-2,3-dicarboximide, etc.;

[0073] Tetracyclic rings with nitrogen-containing functional groups [6.2.1.1] 3,6 .0 2,7 Dodecyl-4-enes, such as tetracyclic [6.2.1.1] 3,6 .0 2,7 [6.2.1.1] Dodecano-9-ene-4-carboxynitrile, tetracyclic [6.2.1.1] 3,6 .0 2,7 [6.2.1.1] Dodecano-9-ene-4-carboxamide and tetracyclic [6.2.1.1] 3,6 .0 2,7 Dodecane-9-ene-4,5-dicarboximide, etc.;

[0074] Bicyclic [2.2.1]hept-2-enes with halogen atoms, such as 5-chloro-2-norbornene, etc.

[0075] Tetracyclic rings containing halogen atoms [6.2.1.1] 3,6 .0 2,7 Dodecyl-4-enes, such as 9-chlorotetracyclo[6.2.1.1] 3, 6 .0 2,7 Dodecyl-4-ene, etc.;

[0076] Bicyclic [2.2.1]hept-2-enes with silicon-containing functional groups, such as 5-trimethoxysilyl-2-norbornene and 5-triethoxysilyl-2-norbornene;

[0077] Tetracyclic rings with silicon-containing functional groups [6.2.1.1] 3,6 .0 2,7 Dodecyl-4-enes, such as 4-trimethoxysilyltetracyclo[6.2.1.1] 3,6 .0 2,7 [6.2.1.1] Dodecyl-9-ene and 4-triethoxysilyltetracyclo[6.2.1.1] 3,6 .0 2,7 Dodecyl-9-ene, etc.

[0078] Norbornene compounds can be used alone or in combination of two or more.

[0079] As a norbornene compound represented by the above general formula (1), those in which m is 0 or 1 are preferred, and those in which m is 0 are more preferred. Furthermore, in the above general formula (1), R... 1 To R 4may be the same or different.

[0080] Among the norbornene-based compounds represented by the above general formula (1), norbornene-based compounds in which R 1 to R 4 is a hydrogen atom, a chain hydrocarbon group having 1 to 20 carbon atoms, or a substituent containing a halogen atom, a silicon atom, an oxygen atom, or a nitrogen atom. In this case, R 1 to R 4 are not particularly limited as long as they are groups that are not bonded to each other and do not form a ring, and can be the same or different, with a hydrogen atom or an alkyl group having 1 to 3 carbon atoms being preferable as R 1 to R 4 . Furthermore, among them, those in which m is 0 or 1 are preferable, with those in which m is 0 being more preferable. As the norbornene-based compounds in which R 1 to R 4 in the above general formula (1) is a hydrogen atom, a chain hydrocarbon group having 1 to 20 carbon atoms, or a substituent containing a halogen atom, a silicon atom, an oxygen atom, or a nitrogen atom, unsubstituted or hydrocarbon-substituted bicyclo[2.2.1]hept-2-ene-based compounds are preferable, and among them, 2-norbornene is particularly preferable.

[0081] Furthermore, as the norbornene-based compounds represented by the above general formula (1), compounds in which R 2 and R 3 are bonded to each other to form a ring are also preferable. Here, specific examples of the ring structure formed by bonding R 2 and R 3 to each other include a cyclopentane ring, a cyclopentene ring, a cyclohexane ring, a cyclohexene ring, and a benzene ring, and the like, which can form a polycyclic structure and can further have a substituent. Among them, a cyclopentane ring, a cyclopentene ring, and a benzene ring are preferable, and particularly, compounds having only a cyclopentene ring or compounds having a polycyclic structure of a cyclopentane ring and a benzene ring are preferable. Note that R 2 and R 3 other than R 1 and R 4 may be the same or different, and a hydrogen atom or an alkyl group having 1 to 3 carbon atoms is preferable. Furthermore, among them, those in which m is 0 are preferable. As the norbornene-based compounds in which R 2 and R 3 in the above general formula (1) are bonded to each other to form a ring, unsubstituted or hydrocarbon-substituted bicyclo[2.2.1]hept-2-ene-based compounds are preferable, and among them, dipentadiene is particularly preferable.

[0082] In the copolymer of cyclopentene and norbornene-based compound, the content ratio of the structural unit derived from cyclopentene is preferably 20 to 75% by mass, more preferably 25 to 70% by mass, still more preferably 30 to 65% by mass, particularly preferably 35 to 60% by mass, with respect to all the repeating structural units of the copolymer. By setting the content ratio of the structural unit derived from cyclopentene in the copolymer to the range of 20 to 75% by mass, the high fuel efficiency and the wear resistance of the rubber composition containing the copolymer can be further improved.

[0083] In the copolymer of cyclopentene and norbornene-based compound, the content ratio of the structural unit derived from the norbornene-based compound represented by the above general formula (1) is preferably 10 to 80% by mass, more preferably 20 to 70% by mass, still more preferably 25 to 65% by mass, particularly preferably 40 to 65% by mass, with respect to all the repeating structural units of the copolymer. By setting the content ratio of the structural unit derived from the norbornene-based compound represented by general formula (1) in the copolymer to the range of 10 to 80% by mass, the high fuel efficiency and the wear resistance of the rubber composition containing the copolymer can be further improved.

[0084] In the copolymer of cyclopentene and norbornene-based compound, it is preferable that the norbornene-based compound represented by the above general formula (1) is 2-norbornene and / or dicyclopentadiene. Since 2-norbornene and dicyclopentadiene are easily available, the copolymer of cyclopentene and 2-norbornene and / or dicyclopentadiene is easily available. Therefore, the rubber composition for tire containing the copolymer of cyclopentene and 2-norbornene and / or dicyclopentadiene is advantageous in terms of cost.

[0085] When 2-norbornene is used as the norbornene-based compound represented by the above general formula (1), the content ratio of the structural unit derived from 2-norbornene is preferably 10 to 60% by mass, more preferably 20 to 60% by mass, with respect to all the repeating structural units of the copolymer of cyclopentene and norbornene-based compound. By setting the content ratio of the structural unit derived from 2-norbornene in the copolymer to the range of 10 to 60% by mass, the high fuel efficiency and the wear resistance of the rubber composition containing the copolymer can be further improved.

[0086] When dicyclopentadiene is used as the norbornene-based compound represented by the above general formula (1), it is preferable that the content ratio of the structural unit derived from dicyclopentadiene be 10 to 60 mass% and more preferably 20 to 50 mass% with respect to all repeating structural units of the copolymer of cyclopentene and the norbornene-based compound. By setting the content ratio of the structural unit derived from dicyclopentadiene in the copolymer to the range of 10 to 60 mass%, the high fuel efficiency and wear resistance of the rubber composition containing the copolymer can be further improved.

[0087] In one embodiment, as the copolymer of cyclopentene and the norbornene-based compound, a terpolymer of cyclopentene (CP), 2-norbornene (NB), and dicyclopentadiene (DCPD) can be used. The terpolymer of cyclopentene, 2-norbornene, and dicyclopentadiene has a significant effect in improving the high fuel efficiency of the rubber composition.

[0088] The copolymer of cyclopentene and the norbornene-based compound can be a copolymer of cyclopentene and the norbornene-based compound represented by the above general formula (1) further copolymerized with other monomers copolymerizable therewith. Examples of such other monomers include: cyclic mono-olefins such as cyclopropene, cyclobutene, methylcyclopentene, cyclohexene, methylcyclohexene, cycloheptene, and cyclooctene; cyclic di-olefins such as cyclohexadiene, methylcyclohexadiene, cyclooctadiene, and methylcyclooctadiene; and polycyclic cyclic olefins having an aromatic ring such as phenylcyclooctene, 5-phenyl-l,5-cyclooctadiene, and phenylcyclopentene. The content ratio of the structural unit derived from the other monomers in the copolymer of cyclopentene and the norbornene-based compound is preferably 40 mass% or less, more preferably 30 mass% or less, and particularly preferably substantially no structural unit derived from the other monomers is contained.

[0089] The weight average molecular weight (Mw) of the copolymer of cyclopentene and the norbornene-based compound is preferably 200,000 to 1,000,000, more preferably 200,000 to 800,000, still more preferably 200,000 to 700,000, and particularly preferably 200,000 to 600,000. The copolymer having a weight average molecular weight (Mw) in the range of 200,000 to 1,000,000 is easy to manufacture and also has good processability (workability). Furthermore, by setting the weight average molecular weight (Mw) of the copolymer to the range of 200,000 to 1,000,000, the high fuel efficiency and wear resistance of the rubber composition containing the copolymer can be further improved.

[0090] Furthermore, the ratio (Mw / Mn, also referred to as "molecular weight distribution") of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the copolymer of cyclopentene and the norbornene-based compound is preferably 1.0 to 5.0, more preferably 1.5 to 2.9, still more preferably 1.5 to 2.5, and particularly preferably 1.5 to 2.3.

[0091] Here, the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the copolymer are polystyrene equivalents measured by gel permeation chromatography (GPC).

[0092] The cis / trans ratio of the copolymer of the cyclopentene and norbornene-based compound is preferably 0 / 100 to 60 / 40, more preferably 5 / 95 to 55 / 45, still more preferably 10 / 90 to 50 / 50, and particularly preferably 15 / 85 to 39 / 61. The cis / trans ratio refers to the ratio (cis / trans) of the contents of the cis structure and the trans structure of the double bond present in the repeating unit constituting the copolymer of the cyclopentene and norbornene-based compound. By setting the cis / trans ratio of the copolymer within the above range, the high fuel efficiency and the wear resistance of the rubber composition containing the copolymer can be further improved.

[0093] The glass transition temperature (Tg) of the copolymer of the cyclopentene and norbornene-based compound is preferably -80°C to 10°C, more preferably -75°C to 0°C, and still more preferably -70°C to -10°C. By setting the glass transition temperature (Tg) of the copolymer within the above range, the high fuel efficiency and the wear resistance of the rubber composition containing the copolymer can be further improved. The glass transition temperature of the copolymer can be controlled, for example, by adjusting the kind and the amount of the norbornene-based compound used.

[0094] The copolymer of the cyclopentene and norbornene-based compound can have a modified group at the end of the polymer chain. By having such an end-modified group, the affinity to silica or the like can be further improved, the dispersibility of silica or the like in the rubber composition can be improved, and as a result, the processability (handleability), the high fuel efficiency, and the wear resistance of the rubber composition can be further improved. The modified group introduced at the end of the polymer chain of the copolymer is not particularly limited, but a modified group containing an atom selected from the group consisting of an atom of Group 15 of the periodic table, an atom of Group 16 of the periodic table, and a silicon atom is preferable. From the viewpoint of further improving the affinity to silica or the like, a modified group containing an atom selected from the group consisting of a nitrogen atom, an oxygen atom, a phosphorus atom, a sulfur atom, and a silicon atom is more preferable, and among them, a modified group containing an atom selected from the group consisting of a nitrogen atom, an oxygen atom, and a silicon atom is still more preferable.

[0095] Examples of the modified group containing a nitrogen atom include an amino group, a pyridyl group, an imino group, an amido group, a nitro group, a carbamate bond, or a hydrocarbon group containing any of these groups. Examples of the modified group containing an oxygen atom include a hydroxyl group, a carboxyl group, an ether group, an ester group, a carbonyl group, an aldehyde group, an epoxy group, or a hydrocarbon group containing any of these groups. Examples of the modified group containing a silicon atom include an alkylsilyl group, an oxysilyl group, or a hydrocarbon group containing any of these groups. Examples of the modified group containing a phosphorus atom include a phosphoric acid group, a phosphine group, or a hydrocarbon group containing any of these groups. Examples of the modified group containing a sulfur atom include a sulfonyl group, a thiol group, a sulfide group, or a hydrocarbon group containing any of these groups. The modified group can also be a modified group containing two or more of the above-described groups. Among them, from the viewpoint of further improving the processability (handleability), high fuel efficiency, and wear resistance of the rubber composition, an amino group, a pyridyl group, an imino group, an amido group, a hydroxyl group, a carboxyl group, an aldehyde group, an epoxy group, an oxysilyl group, or a hydrocarbon group containing any of these groups is preferred, and from the viewpoint of affinity for silica or the like, an oxysilyl group is particularly preferred. Here, the oxysilyl group refers to a group having a silicon-oxygen bond.

[0096] Examples of the oxysilyl group include an alkoxy silyl group, an aryloxy silyl group, an acyloxy group, an alkylsilyloxy silyl group, and an arylsilyloxy silyl group. Furthermore, examples include a hydroxysilyl group obtained by hydrolyzing an alkoxy silyl group, an aryloxy silyl group, or an acyloxy group. Among them, from the viewpoint of affinity for silica, an alkoxy silyl group is preferred. The alkoxy silyl group is a group in which one or more alkoxy groups are bonded to a silicon atom, and specific examples include a trimethoxysilyl group, a dimethoxymethylsilyl group, a methoxydimethylsilyl group, a methoxydichlorosilyl group, a triethoxysilyl group, a diethoxymethylsilyl group, an ethoxydimethylsilyl group, a dimethoxyethoxysilyl group, a methoxydiethoxysilyl group, and a tripropoxysilyl group, etc.

[0097] The introduction ratio of the modified group at the polymer chain end of the copolymer of the cyclopentene and norbornene-based compound is not particularly limited, but as a value of the percentage of the number of the copolymer chain end at which the modified group is introduced to the total number of the copolymer chain ends, it is preferably 10% or more, more preferably 20% or more, still more preferably 30% or more, particularly preferably 40% or more. The higher the introduction ratio of the end modified group, the higher the affinity for silica or the like, which is preferred. The measurement method of the introduction ratio of the modified group at the polymer chain end is not particularly limited, but as an example in the case where an oxysilyl group is introduced as the end modified group, it can be measured from the amount of the oxysilyl group introduced at the end of the copolymer by 1The peak area ratio corresponding to the oxy silyl group obtained by H-NMR spectrum measurement and the number average molecular weight (Mn) obtained by gel permeation chromatography (GPC) are determined.

[0098] The Mooney viscosity (ML 1+4 at 100°C) is preferably 20 to 150, more preferably 22 to 120, and particularly preferably 25 to 90.

[0099] The method for producing the copolymer of a cyclopentene and a norbornene-based compound is not particularly limited, but for example, a method in which a cyclopentene and a norbornene-based compound represented by the above general formula (1) are copolymerized in the presence of a ring-opening polymerization catalyst can be mentioned.

[0100] The ring-opening polymerization catalyst is not particularly limited as long as it can ring-opening copolymerize a cyclopentene and a norbornene-based compound represented by the above general formula (1), but a ruthenium carbene complex or a transition metal compound of Group 6 of the periodic table containing a halogen atom (hereinafter also referred to as "transition metal compound of Group 6 of the periodic table") is preferable. These ring-opening polymerization catalysts can be used alone or in combination of two or more.

[0101] Examples of the ruthenium carbene complex include bis(tricyclohexylphosphine)benzylidene ruthenium dichloride, bis(triphenylphosphine)-3,3-diphenylpropenylidene ruthenium dichloride, bis(tricyclohexylphosphine)tert-butylvinylidene ruthenium dichloride, dichloro-(3-phenyl-1H-inden-1-ylidene)bis(tricyclohexylphosphine) ruthenium, bis(1,3-diisopropylimidazolin-2-ylidene)benzylidene ruthenium dichloride, bis(1,3-dicyclohexylimidazolin-2-ylidene)benzylidene ruthenium dichloride, (1,3-di-mesitylimidazolin-2-ylidene)(tricyclohexylphosphine)benzylidene ruthenium dichloride, (1,3-di-mesitylimidazolidin-2-ylidene)(tricyclohexylphosphine)benzylidene ruthenium dichloride, bis(tricyclohexylphosphine)ethoxymethylene ruthenium dichloride, and (1,3-di-mesitylimidazolidin-2-ylidene)(tricyclohexylphosphine)ethoxymethylene ruthenium dichloride, and the like.

[0102] The Group 6 transition metal compound of the periodic table is a compound having a Group 6 transition metal atom of the periodic table (long periodic table, the same applies hereinafter), specifically, a compound having a chromium atom, a molybdenum atom, or a tungsten atom, and a compound having a molybdenum atom or a tungsten atom is preferred, and particularly, from the viewpoint of high solubility in cyclopentene, a compound having a tungsten atom is more preferred. Specific examples of the Group 6 transition metal compound of the periodic table include molybdenum compounds such as molybdenum pentachloride, oxotetrachloromolybdenum, and (phenylimino) tetrachloromolybdenum; tungsten compounds such as tungsten hexachloride, oxotetrachlorotungsten, (phenylimino) tetrachlorotungsten, monocatacholate tungsten tetrachloride, bis(3,5-di-tert-butyl)catecholate tungsten dichloride, and bis(2-chloroetherate) tetrachloride, and the like.

[0103] The use amount of the ring-opening polymerization catalyst is usually in the range of 1:500 to 1:2,000,000, preferably 1:700 to 1:1,500,000, more preferably 1:1,000 to 1:1,000,000, in terms of the molar ratio (ring-opening polymerization catalyst: monomer for copolymerization). When the Group 6 transition metal compound of the periodic table is used, the amount of the Group 6 transition metal compound of the periodic table is preferably in the range of 1:100 to 1:200,000, more preferably 1:200 to 1:150,000, still more preferably 1:500 to 1:100,000, in terms of the molar ratio (Group 6 transition metal atom in the ring-opening polymerization catalyst: monomer for ring-opening polymerization).

[0104] When the Group 6 transition metal compound of the periodic table is used as the ring-opening polymerization catalyst, it is preferred to be used in combination with an organic aluminum compound represented by the following general formula (2). The organic aluminum compound is used as the ring-opening polymerization catalyst together with the above-mentioned Group 6 transition metal compound of the periodic table.

[0105] (R 5 ) 3-x Al(OR 6 ) x … (2)

[0106] In the above general formula (2), R 5 and R 6 each independently represent a hydrocarbon group having 1 to 20 carbon atoms, preferably a hydrocarbon group having 1 to 10 carbon atoms. In addition, x is 0 < x < 3.

[0107] In the above general formula (2), R5 and R 6 Examples include: alkyl groups such as methyl, ethyl, isopropyl, n - propyl, isobutyl, n - butyl, tert - butyl, n - hexyl, cyclohexyl, n - octyl, n - decyl; and aryl groups such as phenyl, 4 - methylphenyl, 2,6 - dimethylphenyl, 2,6 - diisopropylphenyl, naphthyl; etc.

[0108] Furthermore, in the above general formula (2), 0 < x < 3. That is, in the general formula (2), for R 5 and OR 6 the composition ratios can take any values within the respective ranges of 0 < 3 - x < 3 and 0 < x < 3, but from the viewpoint of achieving high polymerization activity, x is preferably 0.5 < x < 1.5.

[0109] The organoaluminum compound represented by the above general formula (2) can be synthesized, for example, by reacting a trialkylaluminum with an alcohol as shown by the following general formula (3).

[0110] (R 5 )3Al + xR 6 OH → (R 5 ) 3-x Al(OR 6 ) x + (R 6 ) x H … (3)

[0111] In the above general formula (2), x can be arbitrarily controlled by specifying the reaction ratio of the corresponding trialkylaluminum and alcohol as shown by the above general formula (3).

[0112] The amount of the organoaluminum compound used varies depending on the type of the organoaluminum compound used, but relative to the Group 6 transition metal atoms constituting the Group 6 transition metal compound of the periodic table, it is preferably 0.1 to 100 molar equivalents, more preferably 0.2 to 50 molar equivalents, and still more preferably 0.5 to 20 molar equivalents. If the amount of the organoaluminum compound used is too small, the polymerization activity may be insufficient, while if it is too large, side reactions tend to occur during ring - opening polymerization.

[0113] The polymerization reaction can be carried out in the absence of a solvent or in solution. When copolymerizing in solution, the solvent used is not particularly limited as long as it is inactive in the polymerization reaction and can dissolve the cyclopentene, norbornene-based compound represented by the above general formula (1), and a polymerization catalyst, etc. used for copolymerization, but a hydrocarbon solvent or a halogenated solvent is preferably used. Examples of the hydrocarbon solvent include aromatic hydrocarbons such as benzene, toluene, xylene, and ethylbenzene; aliphatic hydrocarbons such as hexane, n-heptane, and n-octane; and alicyclic hydrocarbons such as cyclohexane, cyclopentane, and methylcyclohexane; etc. Examples of the halogenated solvent include halogenated alkanes such as dichloromethane and chloroform; and aromatic halogens such as chlorobenzene and dichlorobenzene; etc. These solvents can be used alone or in combination of two or more.

[0114] When copolymerizing the cyclopentene and the norbornene-based compound represented by the above general formula (1), an olefin compound or a diene compound can be added to the polymerization reaction system as a molecular weight adjuster as needed to adjust the molecular weight of the resulting copolymer.

[0115] The olefin compound is not particularly limited as long as it is an organic compound having an olefinic unsaturated bond, and examples include: a-olefins such as 1-butene, 1-pentene, 1-hexene, and 1-octene; styrene-based compounds such as styrene and vinyltoluene; halogen-containing vinyl compounds such as allyl chloride; alkenyl alcohols such as allyl alcohol and 5-hexenol; silicon-containing vinyl compounds such as allyltrimethoxysilane, allyltriethoxysilane, allyltrichlorosilane, and styryltrimethoxysilane; and disubstituted olefins such as 2-butene and 3-hexene; etc. Examples of the diene compound include non-conjugated dienes such as 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,6-heptadiene, 2-methyl-1,4-pentadiene, and 2,5-dimethyl-1,5-hexadiene.

[0116] The use amount of the olefin compound and the diene compound used as the molecular weight adjuster can be appropriately selected depending on the molecular weight of the copolymer to be manufactured, but the molar ratio to the monomer for copolymerization is generally in the range of 1 / 100 to 1 / 100,000, preferably 1 / 200 to 1 / 50,000, more preferably 1 / 500 to 1 / 10,000.

[0117] Further, in the case where the copolymer of cyclopentene and norbornene-based compound has a modified group at the polymer chain terminal, it is preferable to use an olefinically unsaturated hydrocarbon compound containing a modified group instead of the above-mentioned olefin compound or diene compound as the molecular weight adjusting agent. By using the olefinically unsaturated hydrocarbon compound containing a modified group, the modified group can be appropriately introduced to the polymer chain terminal of the copolymer obtained by copolymerization. The olefinically unsaturated hydrocarbon compound containing a modified group is not particularly limited as long as it has a modified group and has one olefinic carbon-carbon double bond having a metathesis reactivity. For example, when it is desired to introduce an oxysilyl group to the polymer chain terminal of the copolymer, it is sufficient to make an olefinically unsaturated hydrocarbon containing an oxysilyl group exist in the polymerization reaction system.

[0118] Examples of alkoxysilanes containing oxysilyl groups, used as compounds for introducing modifying groups into the polymer chain of a copolymer at only one end (single-terminal), include alkoxysilane compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, allylmethoxydimethylsilane, allyltriethoxysilane, allylethoxydimethylsilane, styryltrimethoxysilane, styryltriethoxysilane, styrylethyltriethoxysilane, allyltriethoxysilylmethyl ether, and allyltriethoxysilylmethylethylamine; aryloxysilane compounds, such as vinyltriphenyloxysilane... Silanes, allyltriphenoxysilanes, and allylphenoxydimethylsilanes; acyloxysilane compounds, such as vinyltriacetoxysilane, allyltriacetoxysilane, allyldiacetoxymethylsilane, and allylacetoxydimethylsilane; alkylsiloxysilane compounds, such as allyltris(trimethylsiloxy)silane; arylsiloxysilane compounds, such as allyltris(triphenylsiloxy)silane; and polysiloxane compounds, such as 1-allylheptamethyltrisiloxane, 1-allylnonamethyltetrasiloxane, 1-allylnonamethylcyclopentasiloxane, and 1-allylundamethylcyclohexasiloxane; etc. Furthermore, examples of compounds used to introduce modifying groups into the two ends (two ends) of the polymer chain of the copolymer include alkoxysilane compounds such as bis(trimethoxysilyl)ethylene, bis(triethoxysilyl)ethylene, 2-butene-1,4-di(trimethoxysilane), 2-butene-1,4-di(triethoxysilane), and 1,4-di(trimethoxysilylmethoxy)-2-butene; and aryloxysilane compounds such as 2-butene-1,4-di(triphenoxysilane). Acyloxysilane compounds, such as 2-butene-1,4-di(triacetoxysilane); alkylsiloxysilane compounds, such as 2-butene-1,4-di[tris(trimethylsiloxy)silane]; arylsiloxysilane compounds, such as 2-butene-1,4-di[tris(triphenylsiloxy)silane]; and polysiloxane compounds, such as 2-butene-1,4-di(heptamethyltrisiloxane) and 2-butene-1,4-di(undecamethylcyclohexasiloxane); etc.

[0119] In addition to introducing the modifying group into the polymer chain end of the copolymer, the olefinic unsaturated hydrocarbon compound containing the modifying group also acts as a molecular weight modifier. Therefore, the amount of the olefinic unsaturated hydrocarbon compound containing the modifying group can be appropriately selected according to the molecular weight of the copolymer to be manufactured, but the molar ratio relative to the comonomer is usually in the range of 1 / 100 to 1 / 100,000, preferably 1 / 200 to 1 / 50,000, more preferably 1 / 500 to 1 / 10,000.

[0120] The polymerization reaction temperature is not particularly limited, but is preferably -100°C or higher, more preferably -50°C or higher, still more preferably 0°C or higher, and particularly preferably 20°C or higher. The upper limit of the polymerization reaction temperature is not particularly limited, but is preferably less than 120°C, more preferably less than 100°C, still more preferably less than 90°C, and particularly preferably less than 80°C. The polymerization reaction time is not particularly limited, but is preferably from 1 minute to 72 hours, more preferably from 10 minutes to 20 hours.

[0121] As needed, the copolymer obtained by the polymerization reaction can have an anti-aging agent such as a phenol-based stabilizer, a phosphorus-based stabilizer, or a sulfur-based stabilizer added thereto. The amount of the anti-aging agent added can be appropriately determined according to the kind thereof or the like. Furthermore, as needed, a filling oil can be blended into the copolymer. When the copolymer is obtained as a polymerization solution, in order to recover the copolymer from the polymerization solution, a known recovery method can be employed. For example, after the solvent is separated by vapor stripping or the like, the solid can be filtered out and further dried, to obtain the copolymer in a solid form.

[0122] The content of the copolymer of a cyclopentene and a norbornene-based compound is preferably from 20 parts by mass to 90 parts by mass, and more preferably from 30 parts by mass to 85 parts by mass, with respect to 100 parts by mass of the rubber component. When the content of the copolymer of a cyclopentene and a norbornene-based compound is in the range of from 20 parts by mass to 90 parts by mass with respect to 100 parts by mass of the rubber component, the balance between the high fuel efficiency, the wear resistance, and the processability of the rubber composition is further improved.

[0123] - Modified Polymer -

[0124] The rubber component contains a modified polymer (modified polymer). Since the modified polymer has a high affinity with the filler and can improve the dispersibility of the filler, the high fuel efficiency, the wear resistance, and the processability of the rubber composition can be improved.

[0125] It should be noted that, in the present specification, the copolymer of a cyclopentene and a norbornene-based compound represented by the above general formula (1) is excluded from the above "modified polymer". That is, the rubber component of the tire rubber composition of the present embodiment contains the copolymer of a cyclopentene and a norbornene-based compound and a modified polymer other than the copolymer.

[0126] Examples of the functional group in the modified polymer include, for example, a nitrogen-containing functional group, a silicon-containing functional group, a tin-containing functional group, and an oxygen-containing functional group, with the nitrogen-containing functional group being preferred. When the modified polymer has a nitrogen-containing functional group, the affinity with the filler is further improved, and the dispersibility of the filler can be further improved, so that the high fuel efficiency, the wear resistance, and the processability of the rubber composition can be further improved.

[0127] The functional group containing a nitrogen atom is preferably selected from the group consisting of:

[0128] a primary amino group, a primary amino group protected with a hydrolyzable protecting group, an onium salt residue of a primary amine, an isocyanate group, a thioisocyanate group, an imino group, an imine residue, an amido group, a secondary amino group protected with a hydrolyzable protecting group, a cyclic secondary amino group, an onium salt residue of a cyclic secondary amine, a non-cyclic secondary amino group, an onium salt residue of a non-cyclic secondary amine, a triisocyanurate residue, a cyclic tertiary amino group, a non-cyclic tertiary amino group, a nitrile group, a pyridyl group, an onium salt residue of a cyclic tertiary amine, and an onium salt residue of a non-cyclic tertiary amine; and has a monovalent hydrocarbon group having 1 to 30 carbon atoms including a linear chain, a branched chain, an alicyclic ring, or an aromatic ring; or can include a monovalent hydrocarbon group having 1 to 30 carbon atoms including a linear chain, a branched chain, an alicyclic ring, or an aromatic ring, which can contain at least one hetero atom selected from the group consisting of an oxygen atom, a sulfur atom, and a phosphorus atom.

[0129] As the modified polymer, a polymer or a copolymer obtained by using a conjugated diene compound or a conjugated diene compound and an aromatic vinyl compound as a monomer, and modifying the molecular terminal and / or main chain of the conjugated diene compound with a modifier; or a polymer obtained by using a conjugated diene compound or a conjugated diene compound and an aromatic vinyl compound as a monomer, and polymerizing or copolymerizing these monomers using a polymerization initiator having a modifying functional group can be used.

[0130] Examples of the conjugated diene compound with respect to the monomer used for synthesizing the modified polymer include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethylbutadiene, 2-phenyl-1,3-butadiene, and 1,3-hexadiene; and examples of the aromatic vinyl compound include styrene, a-methylstyrene, 1-vinylnaphthalene, 3-vinyltoluene, ethylvinylbenzene, divinylbenzene, 4-cyclohexylstyrene, and 2,4,6-trimethylstyrene.

[0131] Examples of the modified polymer include modified isoprene rubber (IR), modified butadiene rubber (BR), modified styrene-butadiene rubber (SBR), and modified styrene-isoprene rubber (SIR), among which modified butadiene rubber (BR) and modified styrene-butadiene rubber (SBR) are preferable, and modified butadiene rubber (BR) is particularly preferable. Modified butadiene rubber (BR) has a low glass transition temperature (Tg), and by combining it with the copolymer of the above-described cyclopentene and norbornene-based compound, the high fuel efficiency and wear resistance of the rubber composition can be further improved. In addition, modified styrene-butadiene rubber (SBR) has a high glass transition temperature (Tg), excellent processability, and also has the effect of suppressing uneven wear of the rubber composition.

[0132] As the modifier, a hydrocarbyloxysilane compound is preferable, and as the hydrocarbyloxysilane compound, a compound represented by the following general formula (i) is preferable.

[0133] R 11 a -Si-(OR 12 ) 4-a … (i)

[0134] In the general formula (i), R 11 and R 12 each independently represent a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, "a" is an integer of 0 to 2, and when a plurality of OR 12 are present, each OR 12 may be the same or different, and the molecule does not contain an active proton.

[0135] As the hydrocarbyloxysilane compound, an aminoalkoxysilane compound represented by the following general formula (ii) is also preferable.

[0136] [Chem. 3]

[0137]

[0138] In the general formula (ii), n1+n2+n3+n4=4 (wherein n2 is an integer of 1 to 4, and n1, n3 and n4 are integers of 0 to 3).

[0139] A 1 is at least one functional group selected from the group consisting of a saturated cyclic tertiary amine compound residue, an unsaturated cyclic tertiary amine compound residue, a ketimine residue, a nitrile group, a (thio)isocyanate group, an isocyanurate group, a nitrile group, a pyridine group, a (thio)ketone group, an amide group, and a primary or secondary amino group having a hydrolysable group. When n4 is 2 or more, A 1 may be the same or different, and A 1 may be a divalent group forming a cyclic structure by bonding to Si.

[0140] R 21 is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and when n1 is 2 or more, they can be the same or different.

[0141] R 22 is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and can contain a nitrogen atom and / or a silicon atom. When n2 is 2 or more, R 22may be the same or different, or can form a ring together.

[0142] R 23 is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, or a halogen atom, and when n3 is 2 or more, they can be the same or different.

[0143] R 24 is a divalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and when n4 is 2 or more, they can be the same or different.

[0144] As the hydrolyzable group in the primary amino group or the secondary amino group having a hydrolyzable group, a trimethylsilyl group or a tert-butyldimethylsilyl group is preferable, and a trimethylsilyl group is particularly preferable.

[0145] The aminoalkoxy silane compound represented by the above general formula (ii) is preferably an aminoalkoxy silane compound represented by the following general formula (iii).

[0146] [Chem. 4]

[0147]

[0148] In general formula (iii), p1 + p2 + p3 = 2 (wherein p2 is an integer of 1 to 2, and p1 and p3 are integers of 0 to 1).

[0149] A 2 is NRa (wherein Ra is a monovalent hydrocarbon group, a hydrolyzable group, or a nitrogen-containing organic group).

[0150] R 25 is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms.

[0151] R 26 is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, or a nitrogen-containing organic group, and can contain a nitrogen atom and / or a silicon atom. When p2 is 2, R 26 may be the same or different, or can form a ring together.

[0152] R 27 is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, or a halogen atom.

[0153] R 28R1is a divalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms.

[0154] As the hydrolysable group, a trimethylsilyl group or a tert-butyldimethylsilyl group is preferable, and a trimethylsilyl group is particularly preferable.

[0155] The aminoalkoxysilane compound represented by the above general formula (ii) is also preferably an aminoalkoxysilane compound represented by the following general formula (iv) or the following general formula (v).

[0156] [Chemical Formula 5]

[0157]

[0158] In the general formula (iv), q1+q2=3 (wherein q1is an integer of 0 to 2, and q2is an integer of 1 to 3).

[0159] R 31 is a divalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms.

[0160] R 32 and R 33 each independently represent a hydrolysable group, a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms.

[0161] R 34 is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and when q1is 2, they can be the same or different.

[0162] R 35 is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and when q2is 2 or more, they can be the same or different.

[0163] Specific examples of the aminoalkoxysilane compound represented by the general formula (iv) include N,N-bis(trimethylsilyl)-3-[diethoxy(methyl)silyl]propylamine (also referred to as "N,N-bis(trimethylsilyl)aminopropylmethyldiethoxysilane").

[0164] [Chemical Formula 6]

[0165]

[0166] In the general formula (v), r1+r2=3 (wherein r1is an integer of 1 to 3, and r2is an integer of 0 to 2).

[0167] R 36 is a divalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms.

[0168] R 37 is a dimethylaminomethyl group, a dimethylaminoethyl group, a diethylaminomethyl group, a diethylaminoethyl group, a methylsilyl(methyl)aminomethyl group, a methylsilyl(methyl)aminoethyl group, a methylsilyl(ethyl)aminomethyl group, a methylsilyl(ethyl)aminoethyl group, a dimethylsilylaminomethyl group, a dimethylsilylaminoethyl group, a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and when r1 is 2 or more, they can be the same or different.

[0169] R 38 is a hydrocarbon oxy group having 1 to 20 carbon atoms, a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and when r2 is 2, they can be the same or different.

[0170] Specific examples of the aminoalkoxy silane compound represented by general formula (v) include N-(1,3-dimethylbutylidene)-3-triethoxysilyl-1-propanamine.

[0171] The aminoalkoxy silane compound represented by the above general formula (ii) is also preferably an aminoalkoxy silane compound represented by the following general formula (vi) or the following general formula (vii).

[0172] [Chem. 7]

[0173]

[0174] In general formula (vi), R 40 is a trimethylsilyl group, a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms.

[0175] R 41 is a hydrocarbon oxy group having 1 to 20 carbon atoms, a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms.

[0176] R 42 is a divalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms.

[0177] Here, TMS represents a trimethylsilyl group (the same applies hereinafter).

[0178] [Chem. 8]

[0179]

[0180] In General Formula (vii), R 43 and R 44 each independently represents a divalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms.

[0181] R 45 is a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, and each R 45 may be the same or different.

[0182] The aminoalkoxysilane compound represented by the above General Formula (ii) is also preferably an aminoalkoxysilane compound represented by the following General Formula (viii) or the following General Formula (ix).

[0183] [Chem. 9]

[0184]

[0185] In General Formula (viii), s1 + s2 is 3 (where s1 is an integer of 0 to 2, and s2 is an integer of 1 to 3).

[0186] R 46 is a divalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms.

[0187] R 47 and R 48 each independently represents a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms. Multiple R 47 or R 48 may be the same or different.

[0188] [Chem. 10]

[0189]

[0190] In General Formula (ix), X is a halogen atom.

[0191] R 49 is a divalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, or a divalent aromatic hydrocarbon group having 6 to 18 carbon atoms.

[0192] R 50 and R 51each independently represents a hydrolyzable group, a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, or R 50 and R 51 may be bonded together to form a divalent organic group.

[0193] R 52 and R 53 each independently represents a halogen atom, a hydrocarbonoxy group, a monovalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms.

[0194] as R 50 and R 51 A hydrolyzable group is preferred, and as the hydrolyzable group, a trimethylsilyl group or a tert-butyldimethylsilyl group is preferred, a trimethylsilyl group is particularly preferred.

[0195] The aminoalkoxysilane compound represented by the above general formula (ii) is also preferably an aminoalkoxysilane compound represented by the following general formula (x), the following general formula (xi), the following general formula (xii), or the following general formula (xiii).

[0196] [Chem. 11]

[0197]

[0198] [Chem. 12]

[0199]

[0200] [Chem. 13]

[0201]

[0202] [Chem. 14]

[0203]

[0204] In general formulas (x) to (xiii), the symbols U and V are each an integer satisfying 0 to 2 and U + V = 2.

[0205] R 54 to R 92 may be the same or different and represent a monovalent or divalent aliphatic or alicyclic hydrocarbon group having 1 to 20 carbon atoms, or a monovalent or divalent aromatic hydrocarbon group having 6 to 18 carbon atoms.

[0206] In general formula (xiii), a and β are integers of 0 to 5.

[0207] Among the compounds satisfying general formulae (x), (xi) and (xii), particularly preferred are N1,N1,N7,N7-tetramethyl-4-((trimethoxysilyl)methyl)heptane-1,7-diamine; 2-((hexyl- dimethoxysilyl)methyl)-N1,N1,N3,N3-2-pentylpropane-1,3-diamine; N1-(3-(dimethylamino)propyl)-N3,N3-dimethyl-N1-(3-(trimethoxysilyl)propyl)propane-1,3-diamine; and 4-(3-(dimethylamino)propyl)-N1,N1,N7,N7-tetramethyl-4-((trimethoxysilyl)methyl)heptane-1,7-diamine.

[0208] Among the compounds satisfying general formula (xiii), particularly preferred are N,N-dimethyl-2-(3-(dimethoxymethylsilyl)propoxy)ethylamine; N,N-bis(trimethylsilyl)-2-(3- (trimethoxysilyl)propoxy)ethylamine; N,N-dimethyl-2-(3-(trimethoxysilyl)propoxy)ethylamine; and N,N-dimethyl-3-(3-(trimethoxysilyl)propoxy)propan-1-amine.

[0209] As the above hydrocarbyloxysilane compound, a compound represented by the following general formula (xiv) is also preferred.

[0210] [Formula 15]

[0211]

[0212] In the above general formula (xiv), A 3 is a monovalent group having at least one functional group selected from the group consisting of (thio)epoxy, (thio)isocyanate, (thio)ketone, (thio)aldehyde, imine, amide, trihydrocarbylisocyanurate, (thio)carboxylate, (thio)metal carboxylate, carboxylic anhydride, carboxylic halide, and dihydrocarbyl carbonate. Here, "(thio)epoxy" means epoxy and thioepoxy, "(thio)isocyanate" means isocyanate and thioisocyanate, "(thio)ketone" means ketone and thioketone, "(thio)aldehyde" means aldehyde and thioaldehyde, "(thio)carboxylate" means carboxylate and thio carboxylate, and "(thio)metal carboxylate" means metal carboxylate and thio metal carboxylate.

[0213] R 101 is a single bond or a divalent inactive hydrocarbon group, and the divalent inactive hydrocarbon group preferably has 1 to 20 carbon atoms.

[0214] R 102 and R 103each independently represents a monovalent aliphatic hydrocarbon group having 1 to 20 carbon atoms, or a monovalent aromatic hydrocarbon group having 6 to 18 carbon atoms, n is an integer of 0 to 2, and when a plurality of R 102 may be the same or different, and when a plurality of OR 102 may be the same or different, and when a plurality of OR 103 may be the same or different, and when a plurality of OR 103 may be the same or different.

[0215] Further, the hydrocarbyloxysilane compound represented by General Formula (xiv) does not include an active proton or onium salt in its molecule.

[0216] In the functional group of A 3 in General Formula (xiv), imines include ketimines, aldimines, and amidines, and (thio)carboxylates include unsaturated carboxylates such as acrylates and methacrylates. As the metal in the (thio)carboxylate metal salt, mention can be made of alkali metals, alkaline earth metals, Al, Sn, and Zn, and the like.

[0217] As the divalent inactive hydrocarbon group in R 101 , an alkylene group having 1 to 20 carbon atoms is preferable. The alkylene group can be linear, branched, or cyclic, but a linear alkylene group is particularly preferable. Examples of such linear alkylene groups include methylene, ethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, octamethylene, decamethylene, and dodecamethylene, and the like.

[0218] As R 102 and R 103 , examples include alkyl groups having 1 to 20 carbon atoms, alkenyl groups having 2 to 18 carbon atoms, aryl groups having 6 to 18 carbon atoms, and aralkyl groups having 7 to 18 carbon atoms. Here, the above-mentioned alkyl and alkenyl groups can be linear, branched, or cyclic, and examples thereof include methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, t-butyl, pentyl, hexyl, octyl, decyl, dodecyl, cyclopentyl, cyclohexyl, ethenyl, propenyl, allyl, hexenyl, octenyl, cyclopentenyl, and cyclohexenyl, and the like. The aryl group can have a substituent such as a lower alkyl group on the aromatic ring, and examples thereof include phenyl, tolyl, xylyl, and naphthyl, and the like. Further, the aralkyl group can have a substituent such as a lower alkyl group on the aromatic ring, and examples thereof include benzyl, phenethyl, and naphthylmethyl, and the like.

[0219] n is an integer of 0 to 2, but 0 is preferable, and it is essential that the molecule does not have an active proton or onium salt.

[0220] As the hydrocarbyloxysilane compound represented by the above general formula (xiv), for example, as the (thio)epoxy group-containing hydrocarbyloxysilane compound, 2- glycidoxyethyltrimethoxysilane, 2-glycidoxyethyltriethoxysilane, (2- glycidoxyethyl)methyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane (hereinafter also referred to as "GPMOS"), 3-glycidoxypropyltriethoxysilane, (3- glycidoxypropyl)methyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl(methyl)dimethoxysilane, 2-(3,4-epoxycyclohexyl)trimethoxysilane, and those in which a thioepoxy group is substituted for the epoxy group in these compounds are preferred, and among them, 3- glycidoxypropyltrimethoxysilane and 2-(3,4-epoxycyclohexyl)trimethoxysilane are particularly preferred.

[0221] As the imine group-containing hydrocarbyloxysilane compound, N-(1,3-dimethyl- butylidene)-3-(triethoxysilyl)-1 -propanamine, N-(1 -methyl-ethylidene)-3-(triethoxysilyl)- 1 -propanamine, N-ethylidene-3-(triethoxysilyl)-1 -propanamine, N-(1 -methyl- propylidene)-3-(triethoxysilyl)-1 -propanamine, N-(4-N,N-dimethylaminobenzylidene)-3- (triethoxysilyl)-1 -propanamine, N-(cyclohexylidene)-3-(triethoxysilyl)-1 -propanamine, and the corresponding trimethoxysilyl compounds, methyldiethoxysilyl compounds, ethyldiethoxysilyl compounds, methyldimethoxysilyl compounds, and ethyldimethoxysilyl compounds, etc. are preferred, and among them, N-(1 -methyl-propylidene)-3-(triethoxysilyl)-1 -propanamine and N-(1,3-dimethyl- butylidene)-3-(triethoxysilyl)-1 -propanamine are particularly preferred.

[0222] As the above-mentioned modifier, a coupling agent represented by the following general formula (xv) is also preferred.

[0223] [Chemical Formula 16]

[0224]

[0225] In the above general formula (xv), R 111 , R 112 , and R 113 each independently represent a single bond or an alkylene group having 1 to 20 carbon atoms.

[0226] R 114 , R 115 , R116 , R 117 , and R 119 each independently represents an alkyl group having 1 to 20 carbon atoms.

[0227] R 118 , and R 121 each independently represents an alkylene group having 1 to 20 carbon atoms.

[0228] R 120 represents an alkyl group having 1 to 20 carbon atoms or a trialkylsilyl group.

[0229] m is an integer of 1 to 3, and p is 1 or 2.

[0230] When a plurality of R 111 to R 121 , m, and p are present, each is independent, and i, j, and k each independently represent an integer of 0 to 6, provided that (i+j+k) is an integer of 3 to 10.

[0231] A 4 represents a hydrocarbon group having 1 to 20 carbon atoms, or an organic group having 1 to 20 carbon atoms, having at least one atom selected from the group consisting of an oxygen atom, a nitrogen atom, a silicon atom, a sulfur atom, and a phosphorus atom, and not having an active hydrogen.

[0232] Here, the hydrocarbon group represented by A 4 in the above general formula (xv) includes saturated, unsaturated, aliphatic, and aromatic hydrocarbon groups. As the organic group not having an active hydrogen, for example, an organic group not having a functional group containing an active hydrogen such as a hydroxyl group (-OH), a secondary amino group (>NH), a primary amino group (-NH2), or a mercapto group (-SH) can be mentioned.

[0233] The coupling agent represented by the general formula (xv) is preferably at least one selected from the group consisting of tetra[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tetra(3-trimethoxysilylpropyl)-1,3-propanediamine, and tetra(3-trimethoxysilylpropyl)-1,3-bisaminomethylcyclohexane.

[0234] As the above modifier, a coupling agent represented by the following general formula (xvi) is also preferable.

[0235] (R 126 ) b ZX c … (xvi)

[0236] In the above general formula (xvi), Z is tin or silicon, and X is chlorine or bromine.

[0237] R126 is selected from the group consisting of an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group having 3 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, and an aralkyl group having 7 to 20 carbon atoms. Here, R 126 Specific examples thereof include a methyl group, an ethyl group, an n-butyl group, a neophyl group, a cyclohexyl group, an n-octyl group, and a 2-ethylhexyl group, and the like.

[0238] b is 0 to 3, and c is 1 to 4, provided that b + c = 4.

[0239] As the coupling agent represented by the above general formula (xvi), tin tetrachloride, (R 126 )SnCl3, (R 126 )2SnCl2, (R 126 )3SnCl, and silicon tetrachloride, and the like are preferable, with tin tetrachloride being particularly preferable.

[0240] As the polymerization initiator having the above modification function, a lithium amide compound is preferable. Examples of such lithium amide compounds include lithium hexamethylenimide, lithium pyrrolidine, lithium piperidine, lithium heptamethylenimide, lithium dodecamethylenimide, lithium dimethylamide, lithium diethylamide, lithium dibutylamide, lithium dipropylamide, lithium diheptylamide, lithium dihexylamide, lithium dioctylamide, lithium di-2-ethylhexylamide, lithium didecylamide, lithium N-methylpiperazine, lithium ethylpropylamide, lithium ethylbutylamide, lithium ethylbenzylamide, and lithium methylphenethylamide, and the like.

[0241] Further, as the above lithium amide compound, a lithium amide compound represented by formula Li-AM [wherein AM is a substituted amino group represented by the following formula (xvii):

[0242] [Chem. 17]

[0243]

[0244] (wherein R 131 and R 132 each independently represent an alkyl group, a cycloalkyl group, or an aralkyl group having 1 to 12 carbon atoms), or a cyclic amino group represented by the following formula (xviii):

[0245] [Chem. 18]

[0246]

[0247] (wherein R 133alkylene, substituted alkylene, oxyalkylene, or N-alkylamino-alkylene) having 3 to 16 methylene groups, and by using the above-mentioned aminolithium compound, a modified polymer in which at least one nitrogen-containing functional group selected from the group consisting of a substituted amino group represented by formula (xvii) and a cyclic amino group represented by formula (xviii) is introduced can be obtained.

[0248] In the above formula (xvii), R 131 and R 132 are an alkyl group, a cycloalkyl group, or an aralkyl group having 1 to 12 carbon atoms, and specific examples include a methyl group, an ethyl group, a butyl group, an octyl group, a cyclohexyl group, a 3-phenyl-1-propyl group, and an isobutyl group, and the like. Note that R 131 and R 132 may be the same or different.

[0249] In the above formula (xviii), R 133 is an alkylene group, a substituted alkylene group, an oxyalkylene group, or an N-alkylamino-alkylene group having 3 to 16 methylene groups. Here, the substituted alkylene group includes a mono-substituted to an octa-substituted alkylene group, and as the substituent, a straight-chain or branched alkyl group having 1 to 12 carbon atoms, a cycloalkyl group, a bicycloalkyl group, an aryl group, or an aralkyl group can be mentioned. Specific examples of R 133 include a trimethylene group, a tetramethylene group, a hexamethylene group, an oxydiethylene group, an N-alkylazadiethylene group, a dodecamethylene group, and a hexadecamethylene group, and the like.

[0250] The above-mentioned aminolithium compound can be prepared primarily from a secondary amine and a lithiated compound and used for a polymerization reaction, or can be generated in a polymerization system.

[0251] As the above secondary amine, in addition to dimethylamine, diethylamine, dibutylamine, dioctylamine, dicyclohexylamine, and diisobutylamine, mention can also be made of cyclic amines such as azepane (also called "hexamethyleneimine (HMI)"), 2-(2-ethylhexyl)pyrrolidine, 3-(2-propyl)pyrrolidine, 3,5-bis(2-ethylhexyl)piperidine, 4-phenylpiperidine, 7-decyl-l-azacyclotridecane, 3,3-dimethyl-l-azacyclotetradecane, 4-dodecyl-l-azacyclooctane, 4-(2-phenylbutyl)-l-azacyclooctane, 3-ethyl-5-cyclohexyl-l-azacycloheptane, 4-hexyl-l-azacycloheptane, 9-isopentyl-l-azacycloheptadecane, 2-methyl-l-azacycloheptadec-9-ene, 3-isobutyl-l-azacyclododecane, 2-methyl-7-t-butyl-l-azacyclododecane, 5-nonyl-l-azacyclododecane, 8-(4'-methylphenyl)-5-pentyl-3-azabicyclo[5.4.0]undecane, l-butyl-6-azabicyclo[3.2.1]octane, 8-ethyl-3-azabicyclo[3.2.1]octane, l-propyl-3-azabicyclo[3.2.2]nonane, 3-(t-butyl)-7-azabicyclo[4.3.0]nonane, and l,5,5-trimethyl-3-azabicyclo[4.4.0]decane, and the like.

[0252] As the above lithium compound, a hydrocarbyllithium such as ethyllithium, n-propyllithium, isopropyl lithium, n-butyllithium, sec-butyllithium, t-octyllithium, n-decyllithium, phenyllithium, 2-naphthyl lithium, 2-butyl-phenyllithium, 4-phenyl-butyllithium, cyclohexyllithium, cyclopentyllithium, and the reaction product of diisopropenylbenzene and butyllithium can be used.

[0253] In the production of the above modified polymer, anionic polymerization using the above polymerization initiator having a modified functional group or the above lithium compound (i.e., a polymerization initiator not having a modified functional group) can be used, but the polymerization reaction mechanism is not limited thereto, and for example, coordination polymerization can also be used.

[0254] Here, when the modified polymer is produced by coordination polymerization, it is preferable to use a rare earth metal compound as the polymerization initiator, and further preferably use a combination of the following (a) component, (b) component, and (c) component.

[0255] The (a) component for coordination polymerization is selected from the group consisting of a rare earth metal compound and a complex of a rare earth metal compound with a Lewis base, and the like. Here, examples of the rare earth metal compound include carboxylates, alkoxides, β-diketone complexes, phosphates, and phosphonates of rare earth elements, and examples of the Lewis base include acetylacetone, tetrahydrofuran, pyridine, N,N-dimethylformamide, thiophene, diphenyl ether, triethylamine, an organophosphorus compound, and a monovalent or divalent alcohol. As the rare earth element in the above rare earth metal compound, lanthanum, neodymium, praseodymium, samarium, and gadolinium are preferable, and among them, neodymium is particularly preferable.

[0256] Further, as specific examples of the (a) component, neodymium versatate, neodymium tris-2-ethylhexanoate and a complex thereof with acetylacetone, neodymium trineodecanoate and a complex thereof with acetylacetone, and neodymium tris-n-butoxide can be mentioned.

[0257] The (b) component for coordination polymerization is selected from an organoaluminum compound. Specific examples of such an organoaluminum compound include trihydrocarbylaluminum compounds, hydrocarbylaluminum hydrides, and hydrocarbylaluminoxane compounds containing a hydrocarbyl group having 1 to 30 carbon atoms. Specific examples of such an organoaluminum compound include trialkylaluminum, dialkylaluminum hydride, alkylaluminum dihydride, and alkylaluminoxane. It is preferable to use a combination of aluminoxane and other organoaluminum compounds as the (b) component.

[0258] The (c) component for coordination polymerization is selected from a compound having a hydrolyzable halogen or a complex thereof with a Lewis base; an organic halide having a tertiary alkyl halide, a benzyl halide, or an allyl halide; and an ionic compound composed of a non-coordinating anion and a counter cation, and the like. Specific examples of such a (c) component include alkylaluminum dichloride, dialkylaluminum chloride, silicon tetrachloride, tin tetrachloride, a complex of zinc chloride with a Lewis base such as an alcohol, a complex of magnesium chloride with a Lewis base such as an alcohol, benzyl chloride, t-butyl chloride, benzyl bromide, t-butyl bromide, and triphenylcarbenium tetrakis(pentafluorophenyl)borate.

[0259] After the reaction with a modifier such as a hydroxyalkylsilane compound, the modified polymer can be further reacted with at least one selected from the group consisting of a condensation accelerator containing a metal element, an inorganic acid, and a metal halide. By the reaction with at least one selected from the group consisting of a condensation accelerator containing a metal element, an inorganic acid, and a metal halide, a modified polymer having a high Mooney viscosity and excellent shape stability can be produced.

[0260] As the condensation accelerator containing a metal element, it is preferable to use a metal compound containing at least one metal selected from metals belonging to Groups 2 to 15 of the periodic table. Specific examples of the metal element include titanium, zirconium, aluminum, bismuth, and tin. As the condensation accelerator containing a metal element, an alkoxide, a carboxylate, or an acetylacetonate complex of the above-mentioned metals is preferable. Specific examples of the condensation accelerator include tetra(2-ethyl-1,3-hexanediol) titanium, tetra(2- ethylhexyloxy) titanium (hereinafter also referred to as "tetra-2-ethylhexyl titanate" or "EHOTi"), tetra(octanediol) titanium, tris(2-ethylhexanoato) bismuth, tetra-n-propoxy zirconium, tetra-n-butoxy zirconium, bis(2-ethylhexanoato) zirconium oxide, bis(oleato) zirconium oxide, triisopropoxy aluminum, tri-sec-butoxy aluminum, tris(2-ethylhexanoato) aluminum, tris(stearato) aluminum, tetra(acetylacetonato) zirconium, tris(acetylacetonato) aluminum, bis(2-ethylhexanoato) tin, and di-n-octyl tin bis(2-ethylhexyl maleate).

[0261] On the other hand, examples of the inorganic acid include hydrochloric acid, sulfuric acid, and phosphoric acid.

[0262] As the metal halide, it is preferable to appropriately use a metal halide containing at least one metal selected from metals belonging to Groups 2 to 15 of the periodic table, and more preferably a halide containing at least one metal atom selected from the group consisting of silicon, tin, aluminum, zinc, titanium, and zirconium. Specific examples of the metal halide include trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, silicon tetrachloride, methyldichlorosilane, tin tetrachloride, diethylaluminum chloride, ethylaluminum sesquichloride, ethylaluminum dichloride, zinc chloride, titanium tetrachloride, bis(cyclopentadienyl)titanium dichloride, zirconium tetrachloride, and bis(cyclopentadienyl)zirconium dichloride.

[0263] The reaction with the inorganic acid or the metal halide is preferably performed in the presence of water. The water can be used alone, as a solution such as an alcohol solution, or as a dispersed micelle in a hydrocarbon solvent.

[0264] After the reaction with the modifier such as a hydrocarbyloxysilane compound, the modified polymer can be stabilized by a carboxylic partial ester reaction with a polyol.

[0265] Here, the carboxylic partial ester of a polyol refers to an ester of a polyol and a carboxylic acid, and means a partial ester having at least one hydroxyl group. Specifically, it is preferable to use an ester of a saccharide or a modified saccharide having 4 or more carbon atoms and a fatty acid. More preferably, the ester is (1) a fatty acid partial ester of a polyol, particularly a partial ester of a polyol and a saturated or unsaturated higher fatty acid having 10 to 20 carbon atoms (which can be a monoester, a diester, or a triester), or (2) an ester compound in which a partial ester of a polycarboxylic acid and a higher alcohol is bonded to a polyol in 1 to 3 units.

[0266] As the polyol used as a raw material for the ester, a sugar having 5 or 6 carbon atoms and at least 3 hydroxyl groups (which can be hydrogenated or can not be hydrogenated), a diol, or a polyhydroxy compound is preferably used. As the raw material fatty acid, a saturated or unsaturated fatty acid having 10 to 20 carbon atoms is preferably used, and examples include stearic acid, lauric acid, and palmitic acid.

[0267] Among the fatty acid esters of polyols, sorbitan fatty acid esters are preferable, and specific examples include sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan tristearate, sorbitan monooleate, and sorbitan trioleate.

[0268] The content of the modified polymer is preferably 5 to 90 parts by mass, more preferably 10 to 80 parts by mass, and still more preferably 15 to 70 parts by mass, with respect to 100 parts by mass of the rubber component. When the content of the modified polymer is 5 to 90 parts by mass with respect to 100 parts by mass of the rubber component, the balance between the high fuel efficiency, the wear resistance, and the processability of the rubber composition is further improved.

[0269] - Other Rubber -

[0270] The rubber component can further include other rubber. Examples of such other rubber include, in addition to natural rubber (NR), unmodified synthetic isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), chlorobutadiene rubber (CR), butyl rubber (IIR), halogenated butyl rubber, ethylene-propylene rubber (EPR, EPDM), fluororubber, silicone rubber, and polyurethane rubber. The content of these other rubbers is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and still more preferably 10 parts by mass or less, with respect to 100 parts by mass of the rubber component.

[0271] (Filler)

[0272] The rubber composition for tires of the present embodiment includes a filler. By including a filler, the reinforcing properties of the rubber composition are improved. Examples of such a filler include carbon black, silica, clay, talc, calcium carbonate, and aluminum hydroxide, with carbon black being preferable.

[0273] The content of the filler is preferably in the range of 5 to 80 parts by mass per 100 parts by mass of the rubber component. When the content of the filler is 5 parts by mass or more per 100 parts by mass of the rubber component, the wear resistance of the rubber composition is further improved, and when it is 80 parts by mass or less, the high fuel efficiency and processability of the rubber composition are further improved. From the viewpoint of wear resistance, the content of the filler is more preferably 10 parts by mass or more, and still more preferably 20 parts by mass or more, per 100 parts by mass of the rubber component, and from the viewpoint of high fuel efficiency and processability, it is more preferably 70 parts by mass or less, and still more preferably 60 parts by mass or less.

[0274] - Carbon Black -

[0275] It is preferable that the filler include carbon black. Since carbon black has a significant effect of reinforcing the rubber composition and improving the wear resistance thereof, the rubber composition for tires including carbon black as the filler has further improved wear resistance.

[0276] The content of the carbon black is preferably in the range of 5 to 80 parts by mass per 100 parts by mass of the rubber component. When the content of the carbon black is 5 parts by mass or more per 100 parts by mass of the rubber component, the wear resistance of the rubber composition is further improved, and when it is 80 parts by mass or less, the high fuel efficiency and processability of the rubber composition are further improved. From the viewpoint of wear resistance, the content of the carbon black is more preferably 10 parts by mass or more, and still more preferably 20 parts by mass or more, per 100 parts by mass of the rubber component, and from the viewpoint of high fuel efficiency and processability, it is more preferably 70 parts by mass or less, and still more preferably 60 parts by mass or less.

[0277] From the viewpoint of the wear resistance of the rubber composition, the proportion of carbon black in the filler is preferably 70% by mass or more, more preferably 80% by mass or more, and still more preferably 90% by mass or more, and can be 100% by mass.

[0278] (Other)

[0279] In addition to the above-described rubber component and filler, the rubber composition for tires of the present embodiment can optionally include various components generally used in the rubber industry, such as a silane coupling agent, an antioxidant, a hydrogenated fatty acid, zinc oxide (zinc white), a tackifier, a vulcanization accelerator, and a vulcanizing agent, as needed, within a range not impairing the object of the present application. Commercially available products can be appropriately used as these compounding agents.

[0280] Examples of the antioxidant include N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6C) and 2,2,4-trimethyl-1,2-dihydroquinoline polymer (TMDQ), and the like. These antioxidants can be used alone, or in combination of two or more. The content of the antioxidant is not particularly limited, but is preferably in the range of 0.1 part by mass to 5 parts by mass, more preferably 1 part by mass to 4 parts by mass, with respect to 100 parts by mass of the rubber component.

[0281] Examples of the hydrogenated fatty acid include stearic acid. The content of the hydrogenated fatty acid is not particularly limited, but is preferably in the range of 0.1 part by mass to 5 parts by mass, more preferably 1 part by mass to 4 parts by mass, with respect to 100 parts by mass of the rubber component.

[0282] The content of the zinc oxide (zinc white) is not particularly limited, but is preferably in the range of 0.1 part by mass to 10 parts by mass, more preferably 1 part by mass to 8 parts by mass, with respect to 100 parts by mass of the rubber component.

[0283] Examples of the tackifier include rosin-based resins, terpene-based resins, petroleum-based resins, phenol-based resins, coal-based resins, and xylene-based resins, among which the petroleum-based resins are preferred. Examples of such petroleum-based resins include C5-based resins, C5 / C9-based resins, C9-based resins, and dicyclopentadiene resins. The content of the tackifier is not particularly limited, but is preferably in the range of 0.1 part by mass to 5 parts by mass, more preferably 0.5 part by mass to 3 parts by mass, with respect to 100 parts by mass of the rubber component.

[0284] Examples of the vulcanization accelerator include sulfenamide-based vulcanization accelerators, guanidine-based vulcanization accelerators, thiazole-based vulcanization accelerators, thiuram-based vulcanization accelerators, and dithiocarbamate-based vulcanization accelerators. These vulcanization accelerators can be used alone, or in combination of two or more. The content of the vulcanization accelerator is not particularly limited, but is preferably in the range of 0.1 part by mass to 5 parts by mass, more preferably 0.2 part by mass to 4 parts by mass, with respect to 100 parts by mass of the rubber component.

[0285] Examples of the vulcanizing agent include sulfur. The content of the vulcanizing agent, in terms of sulfur, is preferably in the range of 0.1 part by mass to 6 parts by mass, more preferably 0.5 part by mass to 3 parts by mass, with respect to 100 parts by mass of the rubber component.

[0286] (Method for producing a rubber composition for tires)

[0287] The method for producing a rubber composition for tires is not particularly limited, but for example, it can be produced by mixing the above-described rubber component and the filler with various components appropriately selected as needed, and then kneading, heating, and extruding, or the like. Furthermore, the rubber composition obtained by vulcanization can be a vulcanized rubber.

[0288] The kneading conditions are not particularly limited, and various conditions such as the input volume of the kneading device, the rotation speed of the rotor, the ram pressure, the kneading temperature, the kneading time, and the kind of the kneading device can be appropriately selected according to the purpose. As the kneading device, a Banbury mixer, an Intermix, a kneader, or a roll, which are generally used for kneading a rubber composition, or the like can be used.

[0289] The heating conditions are also not particularly limited, and various conditions such as the heating temperature, the heating time, and the heating device can be appropriately selected according to the purpose. As the heating device, a heating roll machine, which is generally used for heating a rubber composition, or the like can be used.

[0290] The extrusion conditions are also not particularly limited, and various conditions such as the extrusion time, the extrusion speed, the extrusion device, and the extrusion temperature can be appropriately selected according to the purpose. As the extrusion device, an extruder, which is generally used for extruding a rubber composition, or the like can be used. The extrusion temperature can be appropriately determined.

[0291] The device, the method, and the conditions for vulcanization are not particularly limited, and can be appropriately selected according to the purpose. As the vulcanization device, a forming vulcanizer using a mold or the like, which is generally used for vulcanizing a rubber composition, can be used. For the vulcanization conditions, the temperature is, for example, about 100°C to 190°C.

[0292] <tyre>

[0293] The tire of the present embodiment is characterized by containing the above-described rubber composition for tire. Since the tire of the present embodiment contains the above-described rubber composition for tire, a good balance between high fuel efficiency, wear resistance, and productivity is achieved. As the application site of the rubber composition in the tire, the tread rubber can be mentioned.

[0294] The tire of the present embodiment can be obtained by forming using an unvulcanized rubber composition, and then vulcanizing according to the kind of the tire to be applied, or by forming using a semi-vulcanized rubber that has undergone a preliminary vulcanization step, and then further subjecting it to main vulcanization. The tire of the present embodiment is preferably a pneumatic tire, and as the gas filled in the pneumatic tire, in addition to ordinary air or air adjusted in oxygen partial pressure, a non-reactive gas such as nitrogen, argon, or helium can be used.

[0295] Example

[0296] Hereinafter, the present application will be described in more detail with reference to Examples, but the present application is not limited in any way to the following Examples.

[0297] <Method for synthesizing modified BR1>

[0298] In a pressure-resistant glass container of about 900 mL which had been dried and purged with nitrogen, 283 g of cyclohexane, 50 g of 1,3-butadiene, 0.0057 mmol of 2,2-di-tetrahydrofurylpropane, and 0.513 mmol of hexamethyleneimine (HMI) were added, followed by the addition of 0.57 mmol of n-butyllithium (BuLi). Thereafter, polymerization was performed in a 50°C water bath equipped with a stirring device for 4.5 hours. The polymerization conversion at this time was almost 100%. Next, 0.100 mmol of tin tetrachloride was rapidly added to the polymerization system as a modifier (coupling agent), and the mixture was further stirred at 50°C for 30 minutes to perform a modification reaction. Thereafter, 0.5 mL of a 2,6-di-t-butyl-p-cresol (BHT) isopropyl alcohol solution (BHT concentration: 5 mass%) was added to the polymerization system to terminate the reaction, and the product was further dried according to a conventional method to obtain a modified butadiene rubber containing a tin atom (HMI-BR-Sn: modified BR1). With respect to the obtained modified butadiene rubber (modified BR1), the content of the vinyl bond of the butadiene portion was analyzed by integration ratio analysis of the H-NMR spectrum, and the result was 14%. The glass transition temperature (Tg) was determined from the inflection point of the DSC curve, and was -95°C. The coupling rate was determined from the proportion of the peak area on the highest molecular weight side to the total area of the molecular weight distribution curve by gel permeation chromatography (GPC), and was 65%. 1 The content of the vinyl bond of the butadiene portion was analyzed by integration ratio analysis of the H-NMR spectrum, and the result was 14%. The glass transition temperature (Tg) was determined from the inflection point of the DSC curve, and was -95°C. The coupling rate was determined from the proportion of the peak area on the highest molecular weight side to the total area of the molecular weight distribution curve by gel permeation chromatography (GPC), and was 65%.

[0299] <Method for synthesizing modified BR2>

[0300] In a 5L autoclave purged with nitrogen, 2.4kg of cyclohexane and 300g of 1,3-butadiene were charged under a nitrogen atmosphere. To these, a catalyst prepared in advance by reacting a cyclohexane solution of neodymium versatate (0.09mmol) as a catalyst component, a toluene solution of methylaluminoxane (MAO) (1.8mmol), a toluene solution of diisobutylaluminum hydride (DIBAH) (5.0mmol), a toluene solution of diethylaluminum chloride (0.18mmol), and 1,3-butadiene (4.5mmol) at 50°C for 30 minutes was added, and polymerization was performed at 80°C for 60 minutes. The conversion rate of 1,3-butadiene was close to 100%. 200g of the polymer solution was taken out, a methanol solution containing 1.5g of 2,4-di-t-butyl-p-cresol was added to terminate the polymerization, then the solvent was removed by vapor stripping, and the product was dried on a roll at 110°C to obtain a pre-modified polymer (butadiene rubber). Analysis of the obtained pre-modified polymer by infrared spectroscopy (Morello method) showed that the content of 1,4-cis bond was 97.0%, the content of 1,2-vinyl bond was 1.1%, the molecular weight distribution (Mw / Mn) determined by gel permeation chromatography (GPC) was 2.3, the Mooney viscosity (ML 1+4 at 100°C) was 20, and the content of the vinyl bond of the butadiene portion was 14%. 1+4, 100°C) was 18.

[0301] Further, the remaining polymer solution was maintained at 60°C, a toluene solution of 3-glycidoxypropyltrimethoxysilane (GPMOS) (4.5 mmol) was added, and the mixture was reacted for 30 minutes. Subsequently, a toluene solution of tetra-2-ethylhexyl titanate (EHOTi) (13.5 mmol) was added and mixed for 30 minutes. Thereafter, a methanol solution containing 1.5 g of 2,4-di-tert-butyl-p-cresol was added to obtain 2.5 kg of a modified polymer solution.

[0302] Next, the above modified polymer solution was added to a 20 L aqueous solution adjusted to pH 10 with sodium hydroxide, and a condensation reaction was performed at 110°C for 2 hours while removing the solvent, and then dried on a roll at 110°C to obtain a modified butadiene rubber (modified BR2). Analysis of the obtained modified butadiene rubber (modified BR2) showed a molecular weight distribution (Mw / Mn) of 2.7 determined by GPC, and a Mooney viscosity (ML 1+4 , 125°C) was 43.

[0303] <Method for synthesizing modified BR3>

[0304] In a 5 L autoclave purged with nitrogen, 1.4 kg of cyclohexane, 250 g of 1,3-butadiene, and 0.285 mmol of 2,2-bistetrahydrofurylpropane as a cyclohexane solution were charged under a nitrogen atmosphere, and then 2.85 mmol of n-butyllithium (BuLi) was added. The polymerization was performed in a 50°C water bath equipped with a stirrer for 4.5 hours. The conversion rate of 1,3-butadiene was close to 100%. A portion of the polymer solution was taken out to a methanol solution containing 1.3 g of 2,6-di-tert-butyl-p-cresol to terminate the polymerization, and then the solvent was removed by vapor stripping, and the product was dried on a roll at 110°C to obtain a pre-modified polybutadiene. Measurement of the microstructure (vinyl bond content) of the obtained pre-modified polybutadiene showed that the vinyl bond content was 30 mass%.

[0305] The obtained polymer solution was maintained at 50°C without deactivating the polymerization catalyst, and 1129 mg (3.364 mmol) of N,N-bis(trimethylsilyl)aminopropylmethyldiethoxysilane in which the primary amino group was protected was added, and a modification reaction was performed for 15 minutes.

[0306] Thereafter, 8.11 g of tetra(2-ethyl-1,3-hexanediol) titanium was added as a condensation promoter, and stirring was continued for another 15 minutes.

[0307] Finally, 242 mg of silicon tetrachloride as a metal halide compound and 2,6-di-tert-butyl-p-cresol were added to the polymer solution after the reaction. Next, solvent removal and deprotection of the protected primary amino group were performed by vapor stripping, and the rubber was dried using a roll heated to 110°C to obtain a primary amine-modified butadiene rubber (modified BR3). Measurement of the microstructure (vinyl bond content) of the obtained modified butadiene rubber (modified BR3) showed that the vinyl bond content was 30 mass%.

[0308] <Method for synthesizing copolymer 1>

[0309] Under a nitrogen atmosphere, 65 parts by mass of cyclopentene, 35 parts by mass of 2-norbornene, 300 parts by mass of cyclohexane, and 0.066 parts by mass of 1-hexene were added to a glass reaction vessel equipped with a stirrer. Next, 0.024 parts by mass of the ring-opening polymerization catalyst dichloro-(3-phenyl-1H-inden-1-ylidene)bis(tricyclohexylphosphine)ruthenium(II) dissolved in 1 part by mass of toluene was added, and a polymerization reaction was performed at 20°C for 2 hours. After the polymerization reaction, the polymerization was terminated by adding an excess of vinyl ethyl ether. The polymerization solution was poured into a large excess of methanol containing 2,6-di-tert-butyl-p-cresol (BHT), the precipitated polymer was recovered, washed with methanol, and vacuum dried at 50°C for 24 hours to obtain 67 parts by mass of copolymer 1.

[0310] <Method for synthesizing copolymer 2>

[0311] Under a nitrogen atmosphere, 77 parts by mass of cyclopentene, 23 parts by mass of dicyclopentadiene, 300 parts by mass of cyclohexane, and 0.069 parts by mass of 1-hexene were added to a glass reaction vessel equipped with a stirrer. Next, 0.024 parts by mass of the ring-opening polymerization catalyst dichloro-(3-phenyl-1H-inden-1-ylidene)bis(tricyclohexylphosphine)ruthenium(II) dissolved in 1 part by mass of toluene was added, and a polymerization reaction was performed at 40°C for 2 hours. After the polymerization reaction, the polymerization was terminated by adding an excess of vinyl ethyl ether. The polymerization solution was poured into a large excess of methanol containing 2,6-di-tert-butyl-p-cresol (BHT), the precipitated polymer was recovered, washed with methanol, and vacuum dried at 50°C for 24 hours to obtain 60 parts by mass of copolymer 2.

[0312] <Analysis of copolymer>

[0313] The molecular weight and the proportion of structural units derived from each monomer of each synthesized copolymer were measured by the following method. The results are shown in Table 1.

[0314] (1) Molecular weight

[0315] A gel permeation chromatography (GPC) system "HLC-8220" (manufactured by Tosoh Corporation) was used, two H-type columns "HZ-M" (manufactured by Tosoh Corporation) were connected in series, and measurement was performed at a column temperature of 40°C using tetrahydrofuran as a solvent. As a detector, a differential refractometer "RI-8320" (manufactured by Tosoh Corporation) was used. The weight average molecular weight (Mw) of the copolymer was measured as a polystyrene conversion value.

[0316] (2) Proportion of structural units derived from each monomer

[0317] derived from each monomer constituting the copolymer. 1 The proportion of structural units derived from each monomer constituting the copolymer was determined by H-NMR spectrum measurement.

[0318] [Table 1]

[0319]

[0320] <Preparation of Rubber Composition>

[0321] Each component was blended and kneaded according to the formulation shown in Table 2 to prepare the rubber compositions of the examples and comparative examples.

[0322] In addition, to each rubber composition, as a compounding agent other than the components listed in Table 2, 2 parts by mass of a hydrogenated fatty acid, 3.5 parts by mass of zinc white, 2.5 parts by mass of an antioxidant (total of two kinds), 1 part by mass of a resin, 1.4 parts by mass of a sulfenamide-based vulcanization accelerator, and 1.05 parts by mass of sulfur were further blended with respect to 100 parts by mass of the rubber component.

[0323] <Evaluation of Rubber Composition>

[0324] The high fuel efficiency, wear resistance, and processability of the obtained rubber compositions were evaluated by the following methods. The results are shown in Table 2.

[0325] (3) High Fuel Efficiency

[0326] The loss tangent (tan δ) of the test piece prepared from the obtained rubber composition was measured using a viscoelasticity measuring device (TA Instruments) under conditions of 50°C, 10% strain, and a frequency of 15 Hz. In addition, the modulus (M50) [MPa] of the test piece prepared from the obtained rubber composition at 50% strain was measured at room temperature. The evaluation results were indexed by setting the tan δ / M50 of Comparative Example 3 to 100. The smaller the index value, the smaller the tan δ, indicating better high fuel efficiency.

[0327] (4) Wear Resistance

[0328] The abrasion amount at room temperature was measured according to JIS K 6264-2:2005 using a Lambourn abrasion tester (manufactured by Ueshima Seisakusho Co., Ltd.), in which abrasive paper was attached to the grinding wheel and the sliding rate was 12%. The evaluation results were exponentiated by setting the inverse of the abrasion amount of Comparative Example 3 to 100. The larger the exponent value, the smaller the abrasion amount, indicating better abrasion resistance.

[0329] (5) Processability

[0330] The dynamic storage (shear) modulus G' was measured using an unvulcanized viscoelastic device "RPA2000" (manufactured by ALPHA TECHNOLOGIES) under conditions of 130°C, 1° strain (twist angle), and 100 cpm frequency. The evaluation results were exponentiated by setting the value of Comparative Example 3 to 100. The smaller the exponent value, the lower the unvulcanized rubber viscosity, indicating better processability, and values of 145 or less were considered to be good.

[0331] [Table 2]

[0332]

[0333] *1 NR: Natural rubber

[0334] *2 BR: Butadiene rubber, manufactured by UBE Elastomer Co., Ltd., trade name "BR150L"

[0335] *3 Modified BR1: Modified butadiene rubber synthesized by the above method

[0336] *4 Modified BR2: Modified butadiene rubber synthesized by the above method

[0337] *5 Modified SBR: Manufactured by ENEOS Materials Corporation, trade name "SL563", solution polymerized styrene-butadiene rubber, Sn-modified

[0338] *6 Modified BR3: Modified butadiene rubber synthesized by the above method

[0339] *7 Copolymer 1: Copolymer of a cyclopentene and a norbornene-based compound synthesized by the above method

[0340] *8 Copolymer 2: Copolymer of a cyclopentene and a norbornene-based compound synthesized by the above method

[0341] *9 Carbon black 1: Having a DBP of 130 m 2Carbon black having a cetyltrimethylammonium bromide (CTAB) adsorption specific surface area of 120 mL / g and a dibutyl phthalate (DBP) absorption of 140 mL / 100 g

[0342] *10 Carbon black 2: N234, manufactured by Tokai Carbon Co., Ltd., trade name "SEAST 7HM", CTAB adsorption specific surface area = 119 m 2 / g

[0343] As can be seen from the results shown in Table 2, the rubber compositions of the examples containing the copolymer of a cyclopentene and norbornene-based compound and the modified polymer achieved a good balance between high fuel efficiency, wear resistance, and processability.

[0344] On the other hand, the rubber compositions of Comparative Examples 1 and 2 containing the copolymer of a cyclopentene and norbornene-based compound but not containing the modified polymer exhibited significantly deteriorated processability, and the rubber composition of Comparative Example 5 containing the copolymer of a cyclopentene and norbornene-based compound but not containing the modified polymer exhibited significantly deteriorated wear resistance.

Claims

1. A rubber composition for tires, characterized by, which comprises a rubber component and a filler, wherein the rubber component comprises: a copolymer of cyclopentene and a norbornene-based compound represented by the general formula (1) shown below: ， wherein, in General Formula (1), R 1 to R 4 each independently represent a hydrogen atom, a hydrocarbon group having 1 to 20 carbon atoms, or a substituent group containing a halogen atom, a silicon atom, an oxygen atom, or a nitrogen atom, R 2 and R 3 are optionally bonded to each other to form a ring, and m is an integer of 0 to 2; and a modified polymer.

2. The rubber composition for tires according to claim 1, wherein the norbornene-based compound represented by the general formula (1) is 2-norbornene and / or dicyclopentadiene.

3. The rubber composition for tires according to claim 1, wherein the content of the copolymer of cyclopentene and norbornene-based compound is 20 to 90 parts by mass per 100 parts by mass of the rubber component.

4. The rubber composition for tires according to claim 1, wherein the weight average molecular weight (Mw) of the copolymer of cyclopentene and norbornene-based compound is 200,000 to 1,000,000.

5. The rubber composition for tires according to claim 1, wherein the content ratio of the structural unit derived from cyclopentene of the copolymer of cyclopentene and norbornene-based compound is 20 to 75 mass%.

6. The rubber composition for tires according to claim 2, wherein the content ratio of the structural unit derived from 2-norbornene of the copolymer of cyclopentene and norbornene-based compound is 10 to 60 mass%.

7. The rubber composition for tires according to claim 2, wherein the content ratio of the structural unit derived from dicyclopentadiene of the copolymer of cyclopentene and norbornene-based compound is 10 to 60 mass%.

8. The rubber composition for tires according to claim 1, wherein the content of the modified polymer is 5 to 90 parts by mass per 100 parts by mass of the rubber component.

9. The rubber composition for tires according to claim 1, wherein the modified polymer has a nitrogen-containing functional group.

10. The rubber composition for tires according to claim 1, wherein the modified polymer is a modified butadiene rubber or a modified styrene-butadiene rubber.

11. The rubber composition for tires according to claim 1, wherein the modified polymer is a modified butadiene rubber.

12. The rubber composition for tires according to claim 1, wherein the filler comprises carbon black.

13. A tire comprising the rubber composition for tires according to claim 1.

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