Rubber composition for tire, and tire

Abstract

The present invention addresses the problem of providing a rubber composition for a tire, said composition being capable of providing good balance between processability, and low fuel consumption and wear resistance when applied to a tire. The means for solving the problem is a rubber composition for a tire characterized by including a rubber component and a filler, wherein the rubber component includes: 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, or a substituent including 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

Rubber composition for tires and tires

[0001] The present invention relates to a rubber composition for a tire and a tire.

[0002] In connection with the recent trend toward global carbon dioxide emission regulations accompanying growing interest in environmental issues, there is an increasing demand for improved fuel economy in automobiles. To meet such demands, tire performance is also required to improve fuel economy (i.e., reduce rolling resistance). Furthermore, from the viewpoint of tire economics, in the development of rubber compositions for tires, it is also required to improve wear resistance in addition to fuel economy.

[0003] However, since fuel economy and abrasion resistance are generally in a trade-off relationship, it is difficult to achieve both. For example, a method of increasing the amount of filler to improve abrasion resistance is known, but increasing the amount of filler causes problems such as poor filler dispersion, which deteriorates fuel economy, and further causes problems such as an increase in the unvulcanized viscosity of the rubber composition, which deteriorates processability. Thus, it is generally difficult to achieve a good balance between fuel economy, abrasion resistance, and processability.

[0004] In response to this, Patent Documents 1 and 2 listed below disclose rubber compounds for passenger car tires and rubber compounds for heavy-duty truck and bus tires, each containing a specific long-chain branched cyclopentene ring-opening rubber (LCB-CPR), and these rubber compounds are said to be effective in reducing the rolling resistance of tires, improving wet skid resistance, and improving abrasion resistance.

[0005] International Publication No. 2021 / 178233 International Publication No. 2021 / 178235

[0006] However, the inventors have conducted studies and found that even with the techniques described in Patent Documents 1 and 2, it is difficult to achieve a good balance between the processability of the rubber composition and the fuel economy and wear resistance of a tire using the rubber composition, and that there is still room for improvement.

[0007] Therefore, an object of the present invention is to solve the above-mentioned problems of the conventional technology and to provide a rubber composition for a tire that can achieve a good balance between processability and the fuel economy and abrasion resistance of the tire when applied to the tire. Another object of the present invention is to provide a tire that achieves a good balance between fuel economy, abrasion resistance, and productivity.

[0008] The rubber composition for a tire and the tire of the present invention that solve the above problems are summarized as follows.

[0009] [1] A rubber composition comprising a rubber component and a filler, wherein the rubber component is a rubber composition containing cyclopentene and the following general formula (1): [In the formula, R １ ~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.], and a modified polymer.

[0010] [2] The rubber composition for a tire according to [1], wherein the norbornene-based compound represented by the general formula (1) is 2-norbornene and / or dicyclopentadiene.

[0011] [3] The rubber composition for a tire according to [1] or [2], wherein the content of the copolymer of cyclopentene and a norbornene-based compound is 20 to 90 parts by mass per 100 parts by mass of the rubber component.

[0012] [4] The rubber composition for a tire according to any one of [1] to [3], wherein the copolymer of cyclopentene and a norbornene-based compound has a weight average molecular weight (Mw) of 200,000 to 1,000,000.

[0013] [5] The rubber composition for a tire according to any one of [1] to [4], wherein the copolymer of cyclopentene and a norbornene-based compound has a content of cyclopentene-derived structural units of 20 to 75 mass %.

[0014] [6] The rubber composition for a tire according to any one of [2] to [5], wherein the copolymer of cyclopentene and a norbornene-based compound has a content of structural units derived from 2-norbornene of 10 to 60 mass%.

[0015] [7] The rubber composition for a tire according to any one of [2] to [6], wherein the copolymer of cyclopentene and a norbornene-based compound has a content of structural units derived from dicyclopentadiene of 10 to 60 mass %.

[0016] [8] The rubber composition for a tire according to any one of [1] to [7], wherein the content of the modified polymer is 5 to 90 parts by mass in 100 parts by mass of the rubber component.

[0017] [9] The rubber composition for a tire according to any one of [1] to [8], wherein the modified polymer has a nitrogen-containing functional group.

[0018]

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

[0019]

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

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

[0020]

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

[11] , wherein the filler contains carbon black.

[0021]

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

[12] .

[0022] According to the present invention, it is possible to provide a rubber composition for a tire that can achieve a good balance between processability and the fuel economy and abrasion resistance of the tire when applied to the tire. Furthermore, according to the present invention, it is possible to provide a tire that achieves a good balance between fuel economy, abrasion resistance, and productivity.

[0023] The rubber composition for a tire and the tire of the present invention will be described in detail below by way of example based on embodiments thereof.

[0024] <Definitions> The compounds described herein may be derived in whole or in part from fossil resources, from biological resources such as plant resources, from recycled resources such as used tires, or from a mixture of two or more of fossil resources, biological resources, and recycled resources.

[0025] <Rubber composition for tire> The rubber composition for tire of the present embodiment includes a rubber component and a filler. In the rubber composition for tire of the present embodiment, the rubber component contains cyclopentene and a compound represented by the following general formula (1): [In the formula, R １ ~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.] (also simply referred to as "copolymer of cyclopentene and a norbornene compound" or "copolymer"), and a modified polymer (also simply referred to as "modified polymer").

[0026] In the rubber composition for tires of this embodiment, the copolymer of cyclopentene and a norbornene-based compound is characterized by having crosslinking points and by entanglement of polymer chains. Generally, when a filler is compounded into a rubber component, a reinforcing layer composed of the filler and the rubber component is formed around the filler. This reinforcing layer contributes to improving the reinforcement properties of the rubber composition, thereby improving abrasion resistance, etc. In contrast, in the rubber composition for tires of this embodiment, the rubber component contains the copolymer of cyclopentene and a norbornene-based compound, so that the reinforcing layer formed around the filler is specifically increased by the entanglement of the polymer chains, thereby sufficiently improving abrasion resistance. Furthermore, in the rubber composition for tires of this embodiment, the rubber component contains a modified polymer, which has high affinity with the filler and can improve the dispersibility of the filler, thereby improving the fuel economy, abrasion resistance, and processability of the rubber composition. Therefore, the rubber composition for tires of this embodiment can achieve a good balance between processability and the fuel economy and abrasion resistance of the tire when used in a tire.

[0027] (Rubber Component) The rubber composition for a tire of this embodiment contains a rubber component, and the rubber component provides rubber elasticity to the composition. The rubber component of the rubber composition for a tire of this embodiment contains a copolymer of cyclopentene and a norbornene-based compound represented by the above general formula (1), a modified polymer, and may further contain other rubbers.

[0028] - Copolymer of cyclopentene and norbornene-based compound - The copolymer of cyclopentene and norbornene-based compound contains structural units derived from cyclopentene and structural units derived from the norbornene-based compound represented by the above general formula (1). In a preferred embodiment, the copolymer of cyclopentene and norbornene-based compound is a ring-opening copolymer, and in particular, a cyclopentene ring-opening copolymer.

[0029] In the above general formula (1), R １ ~R ４each 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, tert-butyl, neopentyl, hexyl, and octyl groups; alkenyl groups such as vinyl, allyl, 2-pentenyl, 3-pentenyl, and 4-methyl-3-pentenyl groups; aryl groups such as phenyl, tolyl, 2,6-dimethylphenyl, 2,6-diisopropylphenyl, and naphthyl groups; and aralkyl groups such as benzyl and phenethyl groups.

[0030] Examples of the norbornene compounds represented by the general formula (1) include 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 called "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 called "1,4-methano-1,4,4a,9,9a,10-hexahydroanthracene"), dicyclopentadiene, methyldicyclopentadiene, dihydrodicyclopentadiene ("tricyclo[5.2.1.0 ２，６Bicyclo[2.2.1]hept-2-enes, such as unsubstituted or hydrocarbon-substituted bicyclo[2.2.1]hept-2-enes, such as tetracyclo[6.2.1.1]dec-8-enes; ３，６ .0 ２，７ ] dodec-4-ene, 9-methyltetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-4-ene, 9-ethyltetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-4-ene, 9-cyclohexyltetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-4-ene, 9-cyclopentyltetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-4-ene, 9-methylenetetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-4-ene, 9-ethylidenetetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-4-ene, 9-vinyltetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-4-ene, 9-propenyltetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-4-ene, 9-cyclohexenyltetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-4-ene, 9-cyclopentenyltetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-4-ene, 9-phenyltetracyclo[6.2.1.1 ３，６ .0 ２，７ ] tetracyclo[6.2.1.1] dodec-4-ene and the like, which are unsubstituted or have hydrocarbon substituents; ３，６ .0 ２，７ ] dodec-4-enes; bicyclo[2.2.1]hept-2-enes having an alkoxycarbonyl group such as methyl 5-norbornene-2-carboxylate, ethyl 5-norbornene-2-carboxylate, methyl 2-methyl-5-norbornene-2-carboxylate, and ethyl 2-methyl-5-norbornene-2-carboxylate; tetracyclo[6.2.1.1 ３，６ .0２，７ ] dodec-9-ene-4-carboxylate methyl, 4-methyltetracyclo[6.2.1.1 ３，６ .0 ２，７ ] tetracyclo[6.2.1.1] having an alkoxycarbonyl group, such as methyl dodec-9-ene-4-carboxylate ３，６ .0 ２，７ ] dodec-4-enes; bicyclo[2.2.1]hept-2-enes having a hydroxycarbonyl group or an acid anhydride group, such as 5-norbornene-2-carboxylic acid, 5-norbornene-2,3-dicarboxylic acid, and 5-norbornene-2,3-dicarboxylic acid anhydride; tetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-9-ene-4-carboxylic acid, tetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-9-ene-4,5-dicarboxylic acid, tetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-9-ene-4,5-dicarboxylic anhydride, or other tetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-4-enes; bicyclo[2.2.1]hept-2-enes 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, and 5-methyl-5-(2-hydroxyethoxycarbonyl)-2-norbornene; tetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-9-ene-4-methanol, tetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-9-en-4-ol and other hydroxyl group-containing tetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-4-enes; bicyclo[2.2.1]hept-2-enes having a hydrocarbonyl group such as 5-norbornene-2-carbaldehyde; tetracyclo[6.2.1.1 ３，６.0 ２，７ ] dodec-9-ene-4-carbaldehyde, and the like. ３，６ .0 ２，７ ] dodec-4-enes; bicyclo[2.2.1]hept-2-enes having an alkoxycarbonyl group and a hydroxycarbonyl group, such as 3-methoxycarbonyl-5-norbornene-2-carboxylic acid; bicyclo[2.2.1]hept-2-enes having a carbonyloxy group, such as 5-norbornen-2-yl acetate, 2-methyl-5-norbornen-2-yl acetate, 5-norbornen-2-yl acrylate, and 5-norbornen-2-yl methacrylate; 9-tetracyclo[6.2.1.1] acetate ３，６ .0 ２，７ ] dodec-4-enyl acrylate, 9-tetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-4-enyl, methacrylic acid 9-tetracyclo[6.2.1.1 ３，６ .0 ２，７ ] tetracyclo[6.2.1.1] having a carbonyloxy group such as dodec-4-enyl ３，６ .0 ２，７ ] dodec-4-enes; bicyclo[2.2.1]hept-2-enes having a functional group containing a nitrogen atom, such as 5-norbornene-2-carbonitrile, 5-norbornene-2-carboxamide, and 5-norbornene-2,3-dicarboxylic acid imide; tetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-9-ene-4-carbonitrile, tetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-9-ene-4-carboxamide, tetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-9-ene-4,5-dicarboxylic acid imide, or the like. ３，６ .0 ２，７ ] dodec-4-enes; bicyclo[2.2.1]hept-2-enes having a halogen atom such as 5-chloro-2-norbornene; 9-chlorotetracyclo[6.2.1.1 ３，６ .0 ２，７] tetracyclo[6.2.1.1] dodec-4-ene having a halogen atom, ３，６ .0 ２，７ ] dodec-4-enes; bicyclo[2.2.1]hept-2-enes having a functional group containing a silicon atom, such as 5-trimethoxysilyl-2-norbornene and 5-triethoxysilyl-2-norbornene; 4-trimethoxysilyltetracyclo[6.2.1.1 ３，６ .0 ２，７ ] dodec-9-ene, 4-triethoxysilyltetracyclo[6.2.1.1 ３，６ .0 ２，７ ] tetracyclo[6.2.1.1] having a functional group containing a silicon atom, such as dodec-9-ene ３，６ .0 ２，７ ] dodec-4-enes; etc. The norbornene-based compounds may be used singly or in combination of two or more.

[0031] The norbornene-based compound represented by the general formula (1) is preferably one in which m is 0 or 1, more preferably one in which m is 0. １ ~R ４ may be the same or different.

[0032] Among the norbornene compounds represented by the general formula (1), from the viewpoint of fuel economy and wear resistance of the rubber composition, R １ ~R ４ is preferably 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. １ ~R ４ are not particularly limited as long as they are groups that do not bond to each other and do not form a ring, and may be the same or different. R １ ~R ４ is preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. In this case, m is preferably 0 or 1, and more preferably 0. R in the above general formula (1) １ ~R ４However, as the norbornene-based compound having a substituent containing a hydrogen atom, a chain hydrocarbon group having 1 to 20 carbon atoms, or a halogen atom, a silicon atom, an oxygen atom, or a nitrogen atom, unsubstituted or hydrocarbon-substituted bicyclo[2.2.1]hept-2-enes are preferred, and among these, 2-norbornene is particularly preferred.

[0033] Furthermore, as the norbornene-based compound represented by the general formula (1), R ２ and R ３ Also preferred are compounds in which R and R are bonded to each other to form a ring. ２ and R ３ Specific examples of the ring structure formed by bonding together include a cyclopentane ring, a cyclopentene ring, a cyclohexane ring, a cyclohexene ring, a benzene ring, etc., which may form a polycyclic structure and may further have a substituent. Among these, a cyclopentane ring, a cyclopentene ring, and a benzene ring are preferred, and a compound having a single cyclopentene ring or a polycyclic structure of a cyclopentane ring and a benzene ring is particularly preferred. ２ , R ３ Other than R １ , R ４ may be the same or different, and are preferably a hydrogen atom or an alkyl group having 1 to 3 carbon atoms. In this case, m is preferably 0. ２ and R ３ As the norbornene-based compound in which the above are bonded to each other to form a ring, unsubstituted or hydrocarbon-substituted bicyclo[2.2.1]hept-2-enes are preferred, and among these, dicyclopentadiene is particularly preferred.

[0034] The copolymer of cyclopentene and a norbornene compound preferably contains cyclopentene-derived structural units in an amount of 20 to 75 mass%, more preferably 25 to 70 mass%, even more preferably 30 to 65 mass%, and particularly preferably 35 to 60 mass%, based on the total repeating structural units of the copolymer. By setting the content of cyclopentene-derived structural units in the copolymer to within the range of 20 to 75 mass%, the fuel economy and wear resistance of a rubber composition containing the copolymer can be further improved.

[0035] The copolymer of cyclopentene and a norbornene compound preferably contains structural units derived from the norbornene compound represented by the general formula (1) in an amount of 10 to 80 mass%, more preferably 20 to 70 mass%, even more preferably 25 to 65 mass%, and particularly preferably 40 to 65 mass%, based on the total repeating structural units of the copolymer. By setting the content of structural units derived from the norbornene compound represented by the general formula (1) in the copolymer to be in the range of 10 to 80 mass%, the fuel economy and wear resistance of a rubber composition containing the copolymer can be further improved.

[0036] In the copolymer of cyclopentene and a norbornene-based compound, the norbornene-based compound represented by the general formula (1) is preferably 2-norbornene and / or dicyclopentadiene. Since 2-norbornene and dicyclopentadiene are readily available, copolymers of cyclopentene and 2-norbornene and / or dicyclopentadiene are also readily available. Therefore, rubber compositions for tires containing copolymers of cyclopentene and 2-norbornene and / or dicyclopentadiene are advantageous in terms of cost.

[0037] When 2-norbornene is used as the norbornene compound represented by general formula (1), the copolymer of cyclopentene and a norbornene compound preferably contains 10 to 60 mass% of structural units derived from 2-norbornene, and more preferably 20 to 60 mass%, of the total repeating structural units of the copolymer. By setting the content of 2-norbornene-derived structural units in the copolymer to fall within the range of 10 to 60 mass%, the fuel economy and wear resistance of a rubber composition containing the copolymer can be further improved.

[0038] When dicyclopentadiene is used as the norbornene-based compound represented by the general formula (1), the copolymer of cyclopentene and a norbornene-based compound preferably contains 10 to 60 mass% of dicyclopentadiene-derived structural units, more preferably 20 to 50 mass%, of all repeating structural units of the copolymer. By setting the content of dicyclopentadiene-derived structural units in the copolymer to fall within the range of 10 to 60 mass%, the fuel economy and wear resistance of a rubber composition containing the copolymer can be further improved.

[0039] In one embodiment, the copolymer of cyclopentene and a norbornene-based compound may be a terpolymer of cyclopentene (CP), 2-norbornene (NB), and dicyclopentadiene (DCPD). The terpolymer of cyclopentene, 2-norbornene, and dicyclopentadiene is highly effective in improving the fuel economy of the rubber composition.

[0040] The copolymer of cyclopentene and a norbornene-based compound may be obtained by copolymerizing, in addition to cyclopentene and the norbornene-based compound represented by the general formula (1), other monomers copolymerizable therewith. Examples of such other monomers include cyclic monoolefins such as cyclopropene, cyclobutene, methylcyclopentene, cyclohexene, methylcyclohexene, cycloheptene, and cyclooctene; cyclic diolefins such as cyclohexadiene, methylcyclohexadiene, cyclooctadiene, and methylcyclooctadiene; and polycyclic cycloolefins having an aromatic ring such as phenylcyclooctene, 5-phenyl-1,5-cyclooctadiene, and phenylcyclopentene. The content of structural units derived from other monomers in the copolymer of cyclopentene and a norbornene-based compound is preferably 40% by mass or less, more preferably 30% by mass or less, based on the total repeating structural units of the copolymer. It is particularly preferred that the copolymer is substantially free of structural units derived from other monomers.

[0041] The copolymer of cyclopentene and a norbornene-based compound preferably has a weight-average molecular weight (Mw) of 200,000 to 1,000,000, more preferably 200,000 to 800,000, even more preferably 200,000 to 700,000, and particularly preferably 200,000 to 600,000. Copolymers having a weight-average molecular weight (Mw) in the range of 200,000 to 1,000,000 are easy to produce and have good processability (workability). Furthermore, by setting the weight-average molecular weight (Mw) of the copolymer in the range of 200,000 to 1,000,000, the fuel economy and wear resistance of a rubber composition containing the copolymer can be further improved. Furthermore, the copolymer of cyclopentene and a norbornene-based compound preferably has a ratio of weight-average molecular weight (Mw) to number-average molecular weight (Mn) (Mw / Mn, also referred to as "molecular weight distribution") of 1.0 to 5.0, more preferably 1.5 to 2.9, even more preferably 1.5 to 2.5, and particularly preferably 1.5 to 2.3. Here, the weight average molecular weight (Mw) and number average molecular weight (Mn) of the copolymer are values ​​measured by gel permeation chromatography (GPC) and converted into polystyrene.

[0042] The copolymer of cyclopentene and a norbornene-based compound preferably has a cis / trans ratio of 0 / 100 to 60 / 40, more preferably 5 / 95 to 55 / 45, even more preferably 10 / 90 to 50 / 50, and particularly preferably 15 / 85 to 39 / 61. The cis / trans ratio refers to the ratio of cis-structures to trans-structures of double bonds present in the repeating units constituting the copolymer of cyclopentene and a norbornene-based compound (cis / trans ratio). By setting the cis / trans ratio of the copolymer within the above range, the fuel economy and wear resistance of a rubber composition containing the copolymer can be further improved.

[0043] The copolymer of cyclopentene and a norbornene-based compound preferably has a glass transition temperature (Tg) of -80°C to 10°C, more preferably -75°C to 0°C, and even more preferably -70°C to -10°C. By setting the glass transition temperature (Tg) of the copolymer within the above range, the fuel economy and wear resistance of a rubber composition containing the copolymer can be further improved. The glass transition temperature of the copolymer can be controlled, for example, by adjusting the type and amount of the norbornene-based compound used.

[0044] The copolymer of cyclopentene and a norbornene compound may have a modifying group at the polymer chain end. The presence of such a terminal modifying group can further enhance the affinity for silica and the like, thereby improving the dispersibility of silica and the like in the rubber composition, and as a result, the processability (workability), fuel economy, and abrasion resistance of the rubber composition can be further improved. The modifying group introduced into the polymer chain end of the copolymer is not particularly limited, but is preferably a modifying group containing an atom selected from the group consisting of atoms in Group 15 of the periodic table, atoms in Group 16 of the periodic table, and silicon atoms. From the viewpoint of enhancing affinity for silica and the like, the modifying group for forming the terminal modifying group is more preferably a modifying group containing an atom selected from the group consisting of nitrogen, oxygen, phosphorus, sulfur, and silicon atoms, and among these, a modifying group containing an atom selected from the group consisting of nitrogen, oxygen, and silicon atoms is even more preferred.

[0045] Examples of modifying groups containing nitrogen atoms include amino groups, pyridyl groups, imino groups, amide groups, nitro groups, urethane bond groups, and hydrocarbon groups containing any of these groups. Examples of modifying groups containing oxygen atoms include hydroxyl groups, carboxylic acid groups, ether groups, ester groups, carbonyl groups, aldehyde groups, epoxy groups, and hydrocarbon groups containing any of these groups. Examples of modifying groups containing silicon atoms include alkylsilyl groups, oxysilyl groups, and hydrocarbon groups containing any of these groups. Examples of modifying groups containing phosphorus atoms include phosphate groups, phosphino groups, and hydrocarbon groups containing any of these groups. Examples of modifying groups containing sulfur atoms include sulfonyl groups, thiol groups, thioether groups, and hydrocarbon groups containing any of these groups. The modifying group may also be a modifying group containing multiple of the above groups. Among these, from the viewpoint of further improving the processability (workability), fuel economy, and abrasion resistance of the rubber composition, an amino group, a pyridyl group, an imino group, an amide group, a hydroxyl group, a carboxylic acid 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, etc., an oxysilyl group is particularly preferred. Here, the oxysilyl group refers to a group having a silicon-oxygen bond.

[0046] Examples of the oxysilyl group include an alkoxysilyl group, an aryloxysilyl group, an acyloxy group, an alkylsiloxysilyl group, and an arylsiloxysilyl group.Other examples include a hydroxysilyl group obtained by hydrolyzing an alkoxysilyl group, an aryloxysilyl group, or an acyloxy group.Among these, an alkoxysilyl group is preferred from the viewpoint of affinity with silica.The alkoxysilyl group is a group in which one or more alkoxy groups are bonded to a silicon atom, and specific examples thereof 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.

[0047] The introduction rate of the modified group at the polymer chain end of the copolymer of cyclopentene and norbornene compound is not particularly limited, but is preferably 10% or more, more preferably 20% or more, even more preferably 30% or more, and particularly preferably 40% or more, as a percentage of the number of copolymer chain ends into which the modified group has been introduced / the total number of copolymer chain ends. The higher the introduction rate of the terminal modified group, the higher the affinity for silica and the like, which is preferable. The method for measuring the introduction rate of the modified group at the polymer chain end is not particularly limited, but an example of introducing an oxysilyl group as the terminal modified group is as follows: １ It can be determined from the peak area ratio corresponding to the oxysilyl group determined by H-NMR spectrum measurement and the number average molecular weight (Mn) determined by gel permeation chromatography (GPC).

[0048] The copolymer of cyclopentene and a norbornene-based compound has a Mooney viscosity (ML １＋４ , 100°C) is preferably 20 to 150, more preferably 22 to 120, and particularly preferably 25 to 90.

[0049] The method for producing the copolymer of cyclopentene and a norbornene-based compound is not particularly limited, but examples thereof include a method in which cyclopentene and a norbornene-based compound represented by the general formula (1) are copolymerized in the presence of a ring-opening polymerization catalyst.

[0050] The ring-opening polymerization catalyst is not particularly limited as long as it can ring-open copolymerize cyclopentene with the norbornene-based compound represented by the general formula (1), but a ruthenium carbene complex or a halogen atom-containing Group 6 transition metal compound of the periodic table (hereinafter also referred to as "Group 6 transition metal compound of the periodic table") is preferred. These ring-opening polymerization catalysts may be used alone or in combination of two or more.

[0051] Examples of the ruthenium carbene complex include bis(tricyclohexylphosphine)benzylideneruthenium dichloride, bis(triphenylphosphine)-3,3-diphenylpropenylideneruthenium dichloride, bis(tricyclohexylphosphine)t-butylvinylideneruthenium dichloride, dichloro-(3-phenyl-1H-inden-1-ylidene)bis(tricyclohexylphosphine)ruthenium, bis(1,3-diisopropylimidazolin-2-ylidene)benzylideneruthenium dichloride, and bis(1,3-dicyclohexylimidazolin-2-ylidene)benzylideneruthenium dichloride. (1,3-dimesitylimidazolin-2-ylidene)benzylideneruthenium dichloride, (1,3-dimesitylimidazolin-2-ylidene)(tricyclohexylphosphine)benzylideneruthenium dichloride, (1,3-dimesitylimidazolin-2-ylidene)(tricyclohexylphosphine)benzylideneruthenium dichloride, (1,3-dimesitylimidazolidin-2-ylidene)(tricyclohexylphosphine)benzylideneruthenium dichloride, bis(tricyclohexylphosphine)ethoxymethylideneruthenium dichloride, (1,3-dimesitylimidazolidin-2-ylidene)(tricyclohexylphosphine)ethoxymethylideneruthenium dichloride, and the like.

[0052] 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 period periodic table, the same applies hereinafter), specifically a compound having a chromium atom, a molybdenum atom, or a tungsten atom, with a compound having a molybdenum atom or a compound having a tungsten atom being preferred, and a compound having a tungsten atom being more preferred in terms of high solubility in cyclopentene. Specific examples of the Group 6 transition metal compound of the periodic table include molybdenum compounds such as molybdenum pentachloride, molybdenum oxotetrachloride, and molybdenum(phenylimido)tetrachloride; and tungsten compounds such as tungsten hexachloride, tungsten oxotetrachloride, tungsten(phenylimido)tetrachloride, monocatecholatetungsten tetrachloride, bis(3,5-ditertiarybutyl)catecholatetungsten dichloride, and bis(2-chloroetherate)tetrachloride.

[0053] The amount of the ring-opening polymerization catalyst used, in terms of the molar ratio of (ring-opening polymerization catalyst:monomer used in copolymerization), is usually in the range of 1:500 to 1:2,000,000, preferably 1:700 to 1:1,500,000, and more preferably 1:1,000 to 1:1,000,000. When the Group 6 transition metal compound of the periodic table is used, the amount of the Group 6 transition metal compound used, in terms of the molar ratio of "Group 6 transition metal atom in the ring-opening polymerization catalyst:monomer used in ring-opening polymerization," is preferably in the range of 1:100 to 1:200,000, more preferably 1:200 to 1:150,000, and even more preferably 1:500 to 1:100,000.

[0054] When the above-mentioned transition metal compound of Group 6 of the periodic table is used as the ring-opening polymerization catalyst, it is preferable to use it in combination with an organoaluminum compound represented by the following general formula (2). The organoaluminum compound acts as a ring-opening polymerization catalyst together with the above-mentioned transition metal compound of Group 6 of the periodic table. (R ５ ) ３－ｘ Al (OR ６ ) ｘ ... (2) In the above general formula (2), R ５ and R ６ are each independently a hydrocarbon group having 1 to 20 carbon atoms, preferably a hydrocarbon group having 1 to 10 carbon atoms, and x is 0<x<3.

[0055] In the above general formula (2), R ５ and R ６ Examples of the alkyl group include alkyl groups such as methyl group, ethyl group, isopropyl group, n-propyl group, isobutyl group, n-butyl group, t-butyl group, n-hexyl group, cyclohexyl group, n-octyl group, and n-decyl group; and aryl groups such as phenyl group, 4-methylphenyl group, 2,6-dimethylphenyl group, 2,6-diisopropylphenyl group, and naphthyl group.

[0056] In addition, in the general formula (2), x is 0<x<3. That is, in the general formula (2), R ５ and OR ６The composition ratio of x to x can take any value within the ranges of 0<3-x<3 and 0<x<3, respectively. However, from the viewpoint of increasing the polymerization activity, x is preferably 0.5<x<1.5.

[0057] The organoaluminum compound represented by the general formula (2) can be synthesized, for example, by reacting trialkylaluminum with an alcohol, as shown in the following general formula (3): (R ５ ) ３ Al + xR ６ OH → (R ５ ) ３－ｘ Al (OR ６ ) ｘ + (R ６ ) ｘ H... (3)

[0058] As shown in the general formula (3), x in the general formula (2) can be arbitrarily controlled by specifying the reaction ratio of the corresponding trialkylaluminum and alcohol.

[0059] The amount of the organoaluminum compound used varies depending on the type of organoaluminum compound used, but is preferably 0.1 to 100 times by mole, more preferably 0.2 to 50 times by mole, and even more preferably 0.5 to 20 times by mole, relative to the Group 6 transition metal atoms constituting the Group 6 transition metal compound. If the amount of the organoaluminum compound used is too small, the polymerization activity may be insufficient, whereas if it is too large, side reactions tend to occur more easily during ring-opening polymerization.

[0060] The polymerization reaction may be carried out in a solventless state or in a solution. When copolymerization is carried out in a solution, the solvent used is not particularly limited as long as it is inert to the polymerization reaction and can dissolve the cyclopentene used in the copolymerization, the norbornene-based compound represented by the general formula (1), the polymerization catalyst, and the like. However, it is preferable to use a hydrocarbon solvent or a halogen-based solvent. 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. Examples of the halogen-based solvent include haloalkanes such as dichloromethane and chloroform; and aromatic halogens such as chlorobenzene and dichlorobenzene. These solvents may be used alone or in combination of two or more.

[0061] When copolymerizing cyclopentene with the norbornene-based compound represented by the general formula (1), an olefin compound or a diolefin compound may be added to the polymerization reaction system as a molecular weight modifier, if necessary, to adjust the molecular weight of the resulting copolymer. The olefin compound is not particularly limited as long as it is an organic compound having an ethylenically unsaturated bond, and examples thereof include α-olefins such as 1-butene, 1-pentene, 1-hexene, and 1-octene; styrenes 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. Examples of the diolefin compound include non-conjugated diolefins such as 1,4-pentadiene, 1,4-hexadiene, 1,5-hexadiene, 1,6-heptadiene, 2-methyl-1,4-pentadiene, 2,5-dimethyl-1,5-hexadiene, etc. The amount of the olefin compound or diolefin compound used as a molecular weight modifier may be appropriately selected depending on the molecular weight of the copolymer to be produced, but the molar ratio relative to the monomer used in the copolymerization is usually in the range of 1 / 100 to 1 / 100,000, preferably 1 / 200 to 1 / 50,000, and more preferably 1 / 500 to 1 / 10,000.

[0062] Furthermore, when the copolymer of cyclopentene and a norbornene-based compound is intended to have a modifying group at the polymer chain end, it is preferable to use a modifying group-containing olefinically unsaturated hydrocarbon compound as the molecular weight modifier instead of the above-mentioned olefin compound or diolefin compound. By using a modifying group-containing olefinically unsaturated hydrocarbon compound, the modifying group can be suitably introduced at the polymer chain end of the copolymer obtained by copolymerization. The modifying group-containing olefinically unsaturated hydrocarbon compound is not particularly limited as long as it has a modifying group and one metathesis-reactive olefinic carbon-carbon double bond. For example, when it is desired to introduce an oxysilyl group at the polymer chain end of the copolymer, an oxysilyl group-containing olefinically unsaturated hydrocarbon can be present in the polymerization reaction system.

[0063] Examples of the oxysilyl group-containing olefinically unsaturated hydrocarbon include those which introduce a modifying group only at one end (one end) of the polymer chain of the copolymer, such as alkoxysilane compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, allylmethoxydimethylsilane, allyltriethoxysilane, allylethoxydimethylsilane, styryltrimethoxysilane, styryltriethoxysilane, styrylethyltriethoxysilane, allyltriethoxysilylmethyl ether, and allyltriethoxysilylmethylethylamine; vinyltriphenoxysilane, allyltriphenoxysilane, and aryltriethoxysilane; aryloxysilane compounds such as vinyltriacetoxysilane, allyltriacetoxysilane, allyldiacetoxymethylsilane, and allylacetoxydimethylsilane; 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-allylundecamethylcyclohexasiloxane. Furthermore, examples of compounds for introducing modifying groups into both ends (both 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; aryloxysilane compounds such as 2-butene-1,4-di(triphenoxysilane); and 2-butene. acyloxysilane compounds such as 2-butene-1,4-di[tris(trimethylsiloxy)silane]; alkylsiloxysilane compounds such as 2-butene-1,4-di[tris(triphenylsiloxy)silane]; arylsiloxysilane compounds such as 2-butene-1,4-di[heptamethyltrisiloxane] and 2-butene-1,4-di(undecamethylcyclohexasiloxane); and the like.

[0064] The modifying group-containing olefinically unsaturated hydrocarbon compound acts as a molecular weight modifier in addition to the function of introducing a modifying group into the polymer chain terminal of the copolymer. Therefore, the amount of the modifying group-containing olefinically unsaturated hydrocarbon compound used may be appropriately selected depending on the molecular weight of the copolymer to be produced, but is usually in the range of 1 / 100 to 1 / 100,000, preferably 1 / 200 to 1 / 50,000, and more preferably 1 / 500 to 1 / 10,000 in terms of molar ratio relative to the monomers used in copolymerization.

[0065] The polymerization reaction temperature is not particularly limited, but is preferably −100° C. or higher, more preferably −50° C. or higher, even 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., even more preferably less than 90° C., and particularly preferably less than 80° C. The polymerization reaction time is not particularly limited, but is preferably 1 minute to 72 hours, and more preferably 10 minutes to 20 hours.

[0066] If desired, an antioxidant such as a phenol-based stabilizer, a phosphorus-based stabilizer, or a sulfur-based stabilizer may be added to the copolymer obtained by the polymerization reaction. The amount of the antioxidant to be added may be determined appropriately depending on the type of the antioxidant. Furthermore, if desired, an extender oil may be blended into the copolymer. When the copolymer is obtained as a polymerization solution, a known recovery method may be used to recover the copolymer from the polymerization solution. For example, a method may be used in which the solvent is separated by steam stripping or the like, the solid is filtered off, and then the solid is dried to obtain a solid copolymer.

[0067] The content of the copolymer of cyclopentene and a norbornene compound is preferably 20 to 90 parts by mass, and more preferably 30 to 85 parts by mass, per 100 parts by mass of the rubber component. When the content of the copolymer of cyclopentene and a norbornene compound is in the range of 20 to 90 parts by mass per 100 parts by mass of the rubber component, the balance of fuel economy, abrasion resistance, and processability of the rubber composition is further improved.

[0068] -Modified Polymer- The rubber component includes a modified polymer. The modified polymer has high affinity with fillers and can improve the dispersibility of the fillers, thereby improving the fuel economy, abrasion resistance, and processability of the rubber composition. In this specification, the "modified polymer" excludes the above-mentioned copolymer of cyclopentene and a norbornene-based compound represented by the general formula (1). In other words, the rubber component of the rubber composition for tires of this embodiment includes the above-mentioned copolymer of cyclopentene and a norbornene-based compound and a modified polymer other than the copolymer.

[0069] The modified functional group in the modified polymer may be, for example, a nitrogen-containing functional group, a silicon-containing functional group, a tin-containing functional group, or an oxygen-containing functional group, and among these, a nitrogen-containing functional group is preferred.When the modified polymer has a nitrogen-containing functional group, the affinity with the filler is further increased, and the dispersibility of the filler can be further improved, so that the fuel economy, abrasion resistance, and processability of the rubber composition can be further improved.

[0070] The nitrogen atom-containing functional group is preferably selected from the following: a monovalent hydrocarbon group having a straight-chain, branched, alicyclic, or aromatic ring and having 1 to 30 carbon atoms, and having a functional group selected from the group consisting of 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 imine group, an imine residue, an amide 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, an acyclic secondary amino group, an onium salt residue of an acyclic secondary amine, an isocyanuric acid triester residue, a cyclic tertiary amino group, an acyclic tertiary amino group, a nitrile group, a pyridine residue, an onium salt residue of a cyclic tertiary amine, and an onium salt residue of an acyclic tertiary amine, or a monovalent hydrocarbon group having a straight-chain, branched, alicyclic, or aromatic ring and having 1 to 30 carbon atoms, which may contain at least one heteroatom selected from an oxygen atom, a sulfur atom, and a phosphorus atom.

[0071] The modified polymer may be a polymer obtained by using a conjugated diene compound, or a conjugated diene compound and an aromatic vinyl compound as a monomer, and modifying the molecular terminals and / or main chain of a polymer or copolymer of the conjugated diene compound, or a copolymer of a conjugated diene compound and an aromatic vinyl compound, with a modifying agent; or a polymer obtained by using a conjugated diene compound, or a conjugated diene compound and an aromatic vinyl compound as monomers, and polymerizing or copolymerizing these monomers using a polymerization initiator having a modifying functional group.

[0072] Regarding the monomers used in the synthesis of the modified polymer, examples of conjugated diene compounds include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethylbutadiene, 2-phenyl-1,3-butadiene, and 1,3-hexadiene, and examples of aromatic vinyl compounds include styrene, α-methylstyrene, 1-vinylnaphthalene, 3-vinyltoluene, ethylvinylbenzene, divinylbenzene, 4-cyclohexylstyrene, and 2,4,6-trimethylstyrene.

[0073] Examples of the modified polymer include modified synthetic isoprene rubber (IR), modified butadiene rubber (BR), modified styrene-butadiene rubber (SBR), and modified styrene-isoprene rubber (SIR). Among these, modified butadiene rubber (BR) and modified styrene-butadiene rubber (SBR) are preferred, with modified butadiene rubber (BR) being particularly preferred. Modified butadiene rubber (BR) has a low glass transition temperature (Tg), and by combining it with the above-mentioned copolymer of cyclopentene and a norbornene compound, the fuel economy 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.

[0074] The modifying agent is preferably a hydrocarbyloxysilane compound, and the hydrocarbyloxysilane compound is preferably a compound represented by the following general formula (i): １１ ａ-Si-(OR １２ ) ４－ａ ... (i)

[0075] In general formula (i), R １１ and R １２ each 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, a is an integer of 0 to 2, and OR １２ If there are multiple, each OR １２ may be the same or different, and the molecule does not contain any active protons.

[0076] The hydrocarbyloxysilane compound is also preferably an aminoalkoxysilane compound represented by the following general formula (ii).

[0077] 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). １ is at least one functional group selected from 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 isocyanuric acid trihydrocarbyl ester group, a nitrile group, a pyridine group, a (thio)ketone group, an amide group, and a primary or secondary amino group having a hydrolyzable group. １ may be the same or different, and A １ may be a divalent group that bonds with Si to form a cyclic structure. ２１ 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, and when n1 is 2 or more, they may be the same or different. 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, both of which may contain a nitrogen atom and / or a silicon atom. ２２ may be the same or different, or may be joined together to form a ring. ２３represents 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 may be the same or different when n3 is 2 or greater. ２４ 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, and may be the same or different when n4 is 2 or greater. As the hydrolyzable group in the primary or secondary amino group having a hydrolyzable group, a trimethylsilyl group or a tert-butyldimethylsilyl group is preferred, and a trimethylsilyl group is particularly preferred.

[0078] The aminoalkoxysilane compound represented by the above general formula (ii) is preferably an aminoalkoxysilane compound represented by the following general formula (iii).

[0079] In the 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). ２ is NRa (Ra is a monovalent hydrocarbon group, a hydrolyzable group, or a nitrogen-containing organic group). 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. 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, any of which may contain a nitrogen atom and / or a silicon atom. ２６ may be the same or different, or may be joined together to form a ring. ２７ R 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. ２８ 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. As the hydrolyzable group, a trimethylsilyl group or a tert-butyldimethylsilyl group is preferred, and a trimethylsilyl group is particularly preferred.

[0080] The aminoalkoxysilane compound represented by the above general formula (ii) is also preferably an aminoalkoxysilane compound represented by the following general formula (iv) or (v).

[0081] In the general formula (iv), q1+q2=3 (wherein q1 is an integer of 0 to 2, and q2 is an integer of 1 to 3). 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. ３２ and R ３３ are each independently 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. ３４ are monovalent aliphatic or alicyclic hydrocarbon groups having 1 to 20 carbon atoms or monovalent aromatic hydrocarbon groups having 6 to 18 carbon atoms, and when q1 is 2, they may be the same or different. ３５ 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, and may be the same or different when q2 is 2 or greater. A specific example of the aminoalkoxysilane compound represented by general formula (iv) is N,N-bis(trimethylsilyl)-3-[diethoxy(methyl)silyl]propylamine (also referred to as "N,N-bis(trimethylsilyl)aminopropylmethyldiethoxysilane").

[0082]

[0083] In the general formula (v), r1+r2=3 (where r1 is an integer of 1 to 3, and r2 is an integer of 0 to 2). 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. ３７represents 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 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 may be the same or different. R ３８ represents a hydrocarbyloxy 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 may be the same or different when r2 is 2. A specific example of the aminoalkoxysilane compound represented by general formula (v) is N-(1,3-dimethylbutylidene)-3-triethoxysilyl-1-propanamine.

[0084] The aminoalkoxysilane compound represented by the above general formula (ii) is also preferably an aminoalkoxysilane compound represented by the following general formula (vi) or (vii):

[0085] 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. ４１ R is a hydrocarbyloxy 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. 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, where TMS represents a trimethylsilyl group (the same applies hereinafter).

[0086]

[0087] In general formula (vii), R ４３ and R ４４are each independently 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. 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.

[0088] 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).

[0089] In general formula (viii), s1+s2 is 3 (wherein s1 is an integer of 0 to 2, and s2 is an integer of 1 to 3). 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. ４７ and R ４８ are each independently 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. ４７ or R ４８ may be the same or different.

[0090]

[0091] In general formula (ix), X is a halogen atom. 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. ５０ and R ５１ are each independently 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 are bonded to form a divalent organic group. ５２ and R ５３are each independently a halogen atom, a hydrocarbyloxy 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. ５０ and R ５１ As the hydrolyzable group, a hydrolyzable group is preferred, and as the hydrolyzable group, a trimethylsilyl group or a tert-butyldimethylsilyl group is preferred, and a trimethylsilyl group is particularly preferred.

[0092] 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).

[0093] In the general formulas (x) to (xiii), the symbols U and V are each an integer of 0 to 2 and satisfy U+V=2. ５４ ~ ９２ may be the same or different and are monovalent or divalent aliphatic or alicyclic hydrocarbon groups having 1 to 20 carbon atoms, or monovalent or divalent aromatic hydrocarbon groups having 6 to 18 carbon atoms. α and β in general formula (xiii) are integers of 0 to 5.

[0094] Among the compounds satisfying general formula (x), general formula (xi), and general formula (xii), N1,N1,N7,N7-tetramethyl-4-((trimethoxysilyl)methyl)heptane-1,7-diamine, 2-((hexyl-dimethoxysilyl)methyl)-N1,N1,N3,N3-2-pentamethylpropane-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 are particularly preferred. Among the compounds satisfying general formula (xiii), N,N-dimethyl-2-(3-(dimethoxymethylsilyl)propoxy)ethanamine, N,N-bis(trimethylsilyl)-2-(3-(trimethoxysilyl)propoxy)ethanamine, N,N-dimethyl-2-(3-(trimethoxysilyl)propoxy)ethanamine, and N,N-dimethyl-3-(3-(trimethoxysilyl)propoxy)propan-1-amine are particularly preferred.

[0095] The hydrocarbyloxysilane compound is also preferably a compound represented by the following general formula (xiv):

[0096] In the above general formula (xiv), A ３is a monovalent group having at least one functional group selected from (thio)epoxy, (thio)isocyanate, (thio)ketone, (thio)aldehyde, imine, amide, isocyanuric acid trihydrocarbyl ester, (thio)carboxylic acid ester, metal salt of (thio)carboxylic acid, carboxylic acid anhydride, carboxylic acid halide, and carbonic acid dihydrocarbyl ester. Here, "(thio)epoxy" refers to epoxy and thioepoxy, "(thio)isocyanate" refers to isocyanate and thioisocyanate, "(thio)ketone" refers to ketone and thioketone, "(thio)aldehyde" refers to aldehyde and thioaldehyde, "(thio)carboxylic acid ester" refers to carboxylic acid ester and thiocarboxylic acid ester, and "metal salt of (thio)carboxylic acid" refers to metal salt of carboxylic acid and metal salt of thiocarboxylic acid. R １０１ R is a single bond or a divalent inert hydrocarbon group, and the divalent inert hydrocarbon group preferably has 1 to 20 carbon atoms. １０２ and R １０３ each 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, R １０２ If there are multiple R １０２ may be the same or different, OR １０３ If there are multiple, multiple OR １０３ may be the same or different. The molecule of the hydrocarbyloxysilane compound represented by general formula (xiv) does not contain an active proton or an onium salt.

[0097] In general formula (xiv), A ３ Among the functional groups in R, imine includes ketimine, aldimine, and amidine, and (thio)carboxylic acid ester includes unsaturated carboxylic acid ester such as acrylate and methacrylate. In addition, examples of the metal in the metal salt of (thio)carboxylic acid include alkali metals, alkaline earth metals, Al, Sn, and Zn. １０１Among these, preferred divalent inert hydrocarbon groups are alkylene groups having 1 to 20 carbon atoms. The alkylene groups may be linear, branched, or cyclic, with linear groups being particularly preferred. Examples of linear alkylene groups include methylene, ethylene, trimethylene, tetramethylene, pentamethylene, hexamethylene, octamethylene, decamethylene, and dodecamethylene. R １０２ and R １０３ Examples of the alkyl group include an alkyl group having 1 to 20 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, an aryl group having 6 to 18 carbon atoms, and an aralkyl group having 7 to 18 carbon atoms. Here, the alkyl group and the alkenyl group may be linear, branched, or cyclic, and examples thereof include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, an octyl group, a decyl group, a dodecyl group, a cyclopentyl group, a cyclohexyl group, a vinyl group, a propenyl group, an allyl group, a hexenyl group, an octenyl group, a cyclopentenyl group, and a cyclohexenyl group. The aryl group may have a substituent such as a lower alkyl group on the aromatic ring, and examples thereof include a phenyl group, a tolyl group, a xylyl group, and a naphthyl group. Furthermore, the aralkyl group may have a substituent such as a lower alkyl group on the aromatic ring, examples of which include a benzyl group, a phenethyl group, a naphthylmethyl group, etc. n is an integer of 0 to 2, preferably 0, and the molecule must be free of active protons and onium salts.

[0098] Examples of the hydrocarbyloxysilane compound represented by the general formula (xiv) include (thio)epoxy group-containing hydrocarbyloxysilane compounds such as 2-glycidoxyethyltrimethoxysilane, 2-glycidoxyethyltriethoxysilane, (2-glycidoxyethyl)methyldimethoxysilane, 3-glycidoxypropyltrimethoxysilane (hereinafter also referred to as "GPMOS"), 3-glycidoxypropyltriethoxysilane, (3-glycidoxypropyl)methyldimethoxysilane, 2-(3,4-epoxy Preferred examples of the epoxy silane include 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane, 2-(3,4-epoxycyclohexyl)ethyl(methyl)dimethoxysilane, 2-(3,4-epoxycyclohexyl)trimethoxysilane, and compounds in which the epoxy group is replaced with a thioepoxy group. Of these, 3-glycidoxypropyltrimethoxysilane and 2-(3,4-epoxycyclohexyl)trimethoxysilane are particularly suitable. Furthermore, examples of the imine group-containing hydrocarbyloxycyanide compound include N-(1,3-dimethylbutylidene)-3-(triethoxysilyl)-1-propanamine, N-(1-methylethylidene)-3-(triethoxysilyl)-1-propanamine, N-ethylidene-3-(triethoxysilyl)-1-propanamine, N-(1-methylpropylidene)-3-(triethoxysilyl)-1-propanamine, N-(4-N,N-dimethylaminobenzylidene)-3-(triethoxysilyl)-1-propanamine, N-(cyclohex ... Preferred examples of the triethoxysilyl compounds include N-(1-methylpropylidene)-3-(triethoxysilyl)-1-propanamine and trimethoxysilyl compounds, methyldiethoxysilyl compounds, ethyldiethoxysilyl compounds, methyldimethoxysilyl compounds, and ethyldimethoxysilyl compounds corresponding to these triethoxysilyl compounds. Of these, N-(1-methylpropylidene)-3-(triethoxysilyl)-1-propanamine and N-(1,3-dimethylbutylidene)-3-(triethoxysilyl)-1-propanamine are particularly preferred.

[0099] The modifying agent is preferably a coupling agent represented by the following general formula (xv).

[0100] In the above general formula (xv), R １１１ , R １１２ and R １１３ R each independently represents a single bond or an alkylene group having 1 to 20 carbon atoms. １１４ , R １１５ , R １１６ , R １１７ and R １１９ R each independently represents an alkyl group having 1 to 20 carbon atoms. １１８ and R １２１ R each independently represents an alkylene group having 1 to 20 carbon atoms. １２０ represents an alkyl group or a trialkylsilyl group having 1 to 20 carbon atoms, m represents an integer of 1 to 3, and p represents 1 or 2. R １１１ ~R １２１ When there are a plurality of m and p, each is independent, and each of i, j and k independently represents an integer of 0 to 6, provided that (i+j+k) is an integer of 3 to 10. ４ represents a hydrocarbon group having 1 to 20 carbon atoms or an organic group 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 having no active hydrogen. ４ The hydrocarbon group represented by includes saturated, unsaturated, aliphatic, and aromatic hydrocarbon groups. Examples of organic groups without active hydrogen include a hydroxyl group (—OH), a secondary amino group (>NH), a primary amino group (—NH ２ ), a functional group having an active hydrogen such as a sulfhydryl group (-SH), or an organic group not having such a functional group.

[0101] The coupling agent represented by general formula (xv) is preferably at least one selected from the group consisting of tetrakis[3-(2,2-dimethoxy-1-aza-2-silacyclopentane)propyl]-1,3-propanediamine, tetrakis(3-trimethoxysilylpropyl)-1,3-propanediamine, and tetrakis(3-trimethoxysilylpropyl)-1,3-bisaminomethylcyclohexane.

[0102] As the modifying agent, a coupling agent represented by the following general formula (xvi) is also preferred: (R １２６ ) ｂ ZX ｃ ... (xvi)

[0103] In the above general formula (xvi), Z is tin or silicon, and X is chlorine or bromine. １２６ is selected from the group consisting of alkyl groups having 1 to 20 carbon atoms, cycloalkyl groups having 3 to 20 carbon atoms, aryl groups having 6 to 20 carbon atoms, and aralkyl groups having 7 to 20 carbon atoms, where R １２６ Specific examples of the alkyl group 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. b is an integer of 0 to 3, and c is an integer of 1 to 4, where b+c=4.

[0104] The coupling agent represented by the general formula (xvi) includes tin tetrachloride, (R １２６ ) SnCl ３ , (R １２６ ) ２ SnCl ２ , (R １２６ ) ３ SnCl, silicon tetrachloride, etc. are preferred, and among these, tin tetrachloride is particularly preferred.

[0105] The polymerization initiator having a modified functional group is preferably a lithium amide compound, such as lithium hexamethyleneimide, lithium pyrrolidide, lithium piperidide, lithium heptamethyleneimide, lithium dodecamethyleneimide, lithium dimethylamide, lithium diethylamide, lithium dibutylamide, lithium dipropylamide, lithium diheptylamide, lithium dihexylamide, lithium dioctylamide, lithium di-2-ethylhexylamide, lithium didecylamide, lithium-N-methylpiperazide, lithium ethylpropylamide, lithium ethylbutylamide, lithium ethylbenzylamide, and lithium methylphenethylamide.

[0106] Further, as the lithium amide compound, a compound represented by the formula: Li-AM [wherein AM is represented by the following formula (xvii)] (In the formula, R １３１ and R １３２ are each independently an alkyl group, a cycloalkyl group, or an aralkyl group having 1 to 12 carbon atoms, or a substituted amino group represented by the following formula (xviii): (In the formula, R １３３ represents an alkylene group, a substituted alkylene group, an oxyalkylene group, or an N-alkylamino-alkylene group having 3 to 16 methylene groups. ) is a cyclic amino group represented by the formula (xvii). By using a lithium amide compound represented by the formula (xvii), a modified polymer into which at least one nitrogen-containing functional group selected from the group consisting of a substituted amino group represented by the formula (xvii) and a cyclic amino group represented by the formula (xviii) has been introduced can be obtained.

[0107] In the above formula (xvii), R １３１ and R １３２ is an alkyl group, a cycloalkyl group or an aralkyl group having 1 to 12 carbon atoms, and specific examples thereof 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. 1３１ and R １３２ may be the same or different.

[0108] 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 mono- to octa-substituted alkylene groups, and the substituents include linear or branched alkyl groups, cycloalkyl groups, bicycloalkyl groups, aryl groups, and aralkyl groups having 1 to 12 carbon atoms. １３３ Specifically, a trimethylene group, a tetramethylene group, a hexamethylene group, an oxydiethylene group, an N-alkylazadiethylene group, a dodecamethylene group, a hexadecamethylene group, and the like are preferred.

[0109] The lithium amide compound may be prepared in advance from a secondary amine and a lithium compound and used in the polymerization reaction, or may be generated in the polymerization system. Examples of the secondary amine include dimethylamine, diethylamine, dibutylamine, dioctylamine, dicyclohexylamine, diisobutylamine, and the like, as well as azacycloheptane (also referred to as "hexamethyleneimine (HMI)"), 2-(2-ethylhexyl)pyrrolidine, 3-(2-propyl)pyrrolidine, 3,5-bis(2-ethylhexyl)piperidine, 4-phenylpiperidine, 7-decyl-1-azacyclotridecane, 3,3-dimethyl-1-azacyclotetradecane, 4-dodecyl-1-azacyclooctane, 4-(2-phenylbutyl)-1-azacyclooctane, 3-ethyl-5-cyclohexyl-1-azacycloheptane, 4-hexyl-1-azacycloheptane, 9-methyl-1-azacyclopentane, 10-methyl-1-azacyclopentane, 11-methyl-1-azacyclopentane, 12-methyl-1-azacyclopentane, 13-methyl-1-azacyclopentane, 14-methyl-1-azacyclopentane, 15-methyl-1-azacyclopentane, 16-methyl-1-azacyclopentane, 17-methyl-1-azacyclopentane, 18-methyl-1-azacyclopentane, 19-methyl-1-azacyclopentane, 20-methyl-1-azacyclopentane, 21-methyl-1-azacyclopentane, 22-methyl-1-azacyclopentane, 23-methyl-1-azacyclopentane, 24-methyl-1-azacyclopentane, 25-methyl-1-azacyclopentane, 26-methyl-1-azacyclopentane, 27- -isoamyl-1-azacycloheptadecane, 2-methyl-1-azacycloheptadec-9-ene, 3-isobutyl-1-azacyclododecane, 2-methyl-7-tert-butyl-1-azacyclododecane, 5-nonyl-1-azacyclododecane, 8-(4'-methylphenyl)-5-pentyl-3-azabicyclo[5.4.0]undecane, 1-butyl-6-azabicyclo[3.2.1]octane, 8-ethyl-3-azabicyclo[3.2.1]octane, 1-propyl-3-azabicyclo[3.2.2]nonane, 3-(tert-butyl)-7-azabicyclo[4.3.0]nonane, 1,5,5-trimethyl-3-azabicyclo[4.4.0]decane and other cyclic amines. Furthermore, examples of the lithium compound that can be used include hydrocarbyl lithium such as ethyl lithium, n-propyl lithium, isopropyl lithium, n-butyl lithium, sec-butyl lithium, tert-octyl lithium, n-decyl lithium, phenyl lithium, 2-naphthyl lithium, 2-butyl-phenyl lithium, 4-phenyl-butyl lithium, cyclohexyl lithium, cyclopentyl lithium, and a reaction product of diisopropenyl benzene with butyl lithium.

[0110] In producing the modified polymer, anionic polymerization using the polymerization initiator having the above-mentioned modifying functional group or the lithium compound (i.e., a polymerization initiator not having a modifying functional group) may be used, but the polymerization reaction mechanism is not limited thereto, and for example, coordination polymerization may be used. Here, when producing the modified polymer by coordination polymerization, it is preferable to use a rare earth metal compound as the polymerization initiator, and it is more preferable to use the following components (a), (b), and (c) in combination.

[0111] The component (a) used in the coordination polymerization is selected from rare earth metal compounds and complex compounds of rare earth metal compounds and Lewis bases. Examples of rare earth metal compounds include carboxylates, alkoxides, β-diketone complexes, phosphates, and phosphites of rare earth elements. Examples of Lewis bases include acetylacetone, tetrahydrofuran, pyridine, N,N-dimethylformamide, thiophene, diphenyl ether, triethylamine, organic phosphorus compounds, and monohydric or dihydric alcohols. Preferred rare earth elements in the rare earth metal compounds are lanthanum, neodymium, praseodymium, samarium, and gadolinium, with neodymium being particularly preferred. Specific examples of component (a) include neodymium versatate, neodymium tri-2-ethylhexanoate and its complex compound with acetylacetone, neodymium trineodecanoate and its complex compound with acetylacetone, and neodymium tri-n-butoxide.

[0112] The component (b) used in the coordination polymerization is selected from organoaluminum compounds. Specific examples of the organoaluminum compound include trihydrocarbylaluminum compounds, hydrocarbylaluminum hydrides, and hydrocarbylaluminoxane compounds having a hydrocarbon group having 1 to 30 carbon atoms. Specific examples of the organoaluminum compound include trialkylaluminums, dialkylaluminum hydrides, alkylaluminum dihydrides, and alkylaluminoxanes. It is preferable to use aluminoxane in combination with another organoaluminum compound as the component (b).

[0113] The component (c) used in the coordination polymerization is selected from compounds having a hydrolyzable halogen or complex compounds of these with a Lewis base; organic halides having a tertiary alkyl halide, benzyl halide, or allyl halide; ionic compounds comprising a non-coordinating anion and a counter cation, etc. Specific examples of the component (c) include alkylaluminum dichlorides, dialkylaluminum chlorides, silicon tetrachloride, tin tetrachloride, complexes of zinc chloride with a Lewis base such as an alcohol, complexes of magnesium chloride with a Lewis base such as an alcohol, benzyl chloride, t-butyl chloride, benzyl bromide, t-butyl bromide, triphenylcarbonium tetrakis(pentafluorophenyl)borate, etc.

[0114] The modified polymer may be reacted with a modifier such as a hydrocarbyloxysilane compound and then with a condensation accelerator containing a metal element, or at least one selected from the group consisting of an inorganic acid and a metal halide. By reacting with the condensation accelerator containing a metal element, or at least one selected from the group consisting of an inorganic acid and a metal halide, a modified polymer having a high Mooney viscosity and excellent shape stability can be produced.

[0115] As the condensation accelerator containing a metal element, it is preferable to use a metal compound containing at least one metal selected from metals in Groups 2 to 15 of the periodic table. Specific metal elements include titanium, zirconium, aluminum, bismuth, tin, etc. Furthermore, as the condensation accelerator containing a metal element, an alkoxide, carboxylate, or acetylacetonate complex salt of the above metal is preferable. Specifically, preferred examples of the condensation accelerator include tetrakis(2-ethyl-1,3-hexanediolato)titanium, tetrakis(2-ethylhexyloxy)titanium (hereinafter also referred to as "tetra 2-ethylhexyl titanate" or "EHOTi"), tetra(octanediolate)titanium, tris(2-ethylhexanoate)bismuth, tetra-n-propoxyzirconium, tetra-n-butoxyzirconium, bis(2-ethylhexanoate)zirconium oxide, bis(oleate)zirconium oxide, tri-i-propoxyaluminum, tri-sec-butoxyaluminum, tris(2-ethylhexanoate)aluminum, tris(stearate)aluminum, zirconium tetrakis(acetylacetonate), aluminum tris(acetylacetonate), bis(2-ethylhexanoate)tin, and di-n-octyltin bis(2-ethylhexyl maleate).

[0116] On the other hand, examples of the inorganic acid include hydrochloric acid, sulfuric acid, and phosphoric acid. Furthermore, as the metal halide, a metal halide containing at least one metal selected from Groups 2 to 15 of the periodic table can be suitably used. For example, a halide containing at least one metal atom selected from the group consisting of silicon, tin, aluminum, zinc, titanium, and zirconium is more preferred. Specifically, the metal halide is preferably trimethylsilyl chloride, dimethyldichlorosilane, methyltrichlorosilane, silicon tetrachloride, methyldichlorosilane, tin tetrachloride, diethylaluminum chloride, ethylaluminum sesquichloride, ethylaluminum dichloride, zinc chloride, titanium tetrachloride, titanocene dichloride, zirconium tetrachloride, or zirconocene dichloride. The reaction with the inorganic acid or metal halide is preferably carried out in the presence of water. The water may be used in the form of a pure substance, a solution such as an alcohol, or a micelle dispersion in a hydrocarbon solvent.

[0117] The modified polymer may be stabilized by reacting it with a modifying agent such as a hydrocarbyloxysilane compound and then reacting it with a carboxylic acid partial ester of a polyhydric alcohol. Here, the carboxylic acid partial ester of a polyhydric alcohol refers to an ester of a polyhydric alcohol and a carboxylic acid, which has one or more hydroxyl groups. Specifically, esters of sugars or modified sugars having 4 or more carbon atoms and fatty acids are preferably used. More preferred examples of this ester include (1) fatty acid partial esters of polyhydric alcohols, particularly partial esters (monoesters, diesters, or triesters) of saturated or unsaturated higher fatty acids having 10 to 20 carbon atoms and polyhydric alcohols, and (2) ester compounds in which 1 to 3 partial esters of polycarboxylic acids and higher alcohols are bonded to a polyhydric alcohol. The polyhydric alcohol used as a raw material for the partial ester is preferably a sugar having 5 or 6 carbon atoms and at least three hydroxyl groups (which may be hydrogenated or not), glycol, or polyhydroxy compound. The raw material fatty acid is preferably a saturated or unsaturated fatty acid having 10 to 20 carbon atoms, such as stearic acid, lauric acid, or palmitic acid. Among the fatty acid partial esters of the polyhydric alcohols, sorbitan fatty acid esters are preferred, and specific examples include sorbitan monolaurate, sorbitan monopalmitate, sorbitan monostearate, sorbitan tristearate, sorbitan monooleate, and sorbitan trioleate.

[0118] The content of the modified polymer is preferably 5 to 90 parts by mass, more preferably 10 to 80 parts by mass, and even more preferably 15 to 70 parts by mass, per 100 parts by mass of the rubber component. When the content of the modified polymer is 5 to 90 parts by mass or more per 100 parts by mass of the rubber component, the balance of fuel economy, abrasion resistance, and processability of the rubber composition is further improved.

[0119] -Other Rubber- The rubber component may further contain other rubber. Examples of such other rubber include natural rubber (NR), unmodified synthetic isoprene rubber (IR), butadiene rubber (BR), styrene-butadiene rubber (SBR), chloroprene rubber (CR), butyl rubber (IIR), halogenated butyl rubber, ethylene-propylene rubber (EPR, EPDM), fluororubber, silicone rubber, and urethane rubber. The content of these other rubbers is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 10 parts by mass or less, per 100 parts by mass of the rubber component.

[0120] (Filler) The rubber composition for a tire of this embodiment contains a filler. By containing a filler, the reinforcing property of the rubber composition is improved. Examples of the filler include carbon black, silica, clay, talc, calcium carbonate, aluminum hydroxide, etc., and among these, carbon black is preferred.

[0121] 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 abrasion resistance of the rubber composition is further improved, and when the content is 80 parts by mass or less, the fuel economy and processability of the rubber composition are further improved. From the viewpoint of abrasion resistance, the content of the filler is more preferably 10 parts by mass or more, and even more preferably 20 parts by mass or more, per 100 parts by mass of the rubber component. From the viewpoint of fuel economy and processability, the content of the filler is more preferably 70 parts by mass or less, and even more preferably 60 parts by mass or less.

[0122] - Carbon Black - The filler preferably contains carbon black, which has a significant effect of reinforcing the rubber composition and improving the abrasion resistance of the rubber composition, and therefore a rubber composition for tires containing carbon black as a filler has further improved abrasion resistance.

[0123] The carbon black content is preferably in the range of 5 to 80 parts by mass per 100 parts by mass of the rubber component. When the carbon black content is 5 parts by mass or more per 100 parts by mass of the rubber component, the abrasion resistance of the rubber composition is further improved, and when the carbon black content is 80 parts by mass or less, the fuel economy and processability of the rubber composition are further improved. From the viewpoint of abrasion resistance, the carbon black content is more preferably 10 parts by mass or more, and even more preferably 20 parts by mass or more, per 100 parts by mass of the rubber component. From the viewpoint of fuel economy and processability, the carbon black content is more preferably 70 parts by mass or less, and even more preferably 60 parts by mass or less.

[0124] From the viewpoint of the abrasion 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, even more preferably 90% by mass or more, and may be 100% by mass.

[0125] (Others) In addition to the rubber component and filler described above, the rubber composition for a tire of this embodiment may contain, as necessary, various components commonly used in the rubber industry, such as a silane coupling agent, an antioxidant, a hardened fatty acid, zinc oxide (zinc white), a tackifier, a vulcanization accelerator, a vulcanizing agent, etc., appropriately selected within a range that does not impair the object of the present invention. Commercially available products can be suitably used as these compounding ingredients.

[0126] Examples of the antioxidant include N-(1,3-dimethylbutyl)-N'-phenyl-p-phenylenediamine (6C) and 2,2,4-trimethyl-1,2-dihydroquinoline polymer (TMDQ). These antioxidants may be used alone or in combination of two or more. The content of the antioxidant is not particularly limited, and is preferably in the range of 0.1 to 5 parts by mass, and more preferably 1 to 4 parts by mass, per 100 parts by mass of the rubber component.

[0127] Examples of the hardened fatty acid include stearic acid, etc. The content of the hardened fatty acid is not particularly limited, but is preferably in the range of 0.1 to 5 parts by mass, and more preferably 1 to 4 parts by mass, per 100 parts by mass of the rubber component.

[0128] The content of the zinc oxide (zinc white) is not particularly limited, but is preferably in the range of 0.1 to 10 parts by mass, and more preferably 1 to 8 parts by mass, per 100 parts by mass of the rubber component.

[0129] Examples of the tackifier include rosin-based resins, terpene-based resins, petroleum-based resins, phenol-based resins, coal-based resins, and xylene-based resins, and among these, petroleum-based resins are preferred. ５ based resin, C ５ -C ９ based resin, C ９ The content of the tackifier is not particularly limited, and is preferably in the range of 0.1 to 5 parts by mass, and more preferably 0.5 to 3 parts by mass, per 100 parts by mass of the rubber component.

[0130] Examples of the vulcanization accelerator include sulfenamide vulcanization accelerators, guanidine vulcanization accelerators, thiazole vulcanization accelerators, thiuram vulcanization accelerators, and dithiocarbamate vulcanization accelerators. These vulcanization accelerators may be used alone or in combination of two or more. The content of the vulcanization accelerator is not particularly limited, and is preferably in the range of 0.1 to 5 parts by mass, more preferably 0.2 to 4 parts by mass, per 100 parts by mass of the rubber component.

[0131] The vulcanizing agent may be sulfur, etc. The content of the vulcanizing agent is preferably in the range of 0.1 to 6 parts by mass, more preferably 0.5 to 3 parts by mass, in terms of sulfur content, per 100 parts by mass of the rubber component.

[0132] (Method for producing rubber composition for tire) The method for producing the rubber composition for tire is not particularly limited, but the rubber composition for tire can be produced, for example, by blending various components appropriately selected as necessary with the above-mentioned rubber component and filler, and kneading, heating, extruding, etc. Furthermore, the obtained rubber composition can be vulcanized to produce a vulcanized rubber.

[0133] The conditions for the kneading 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, the type of kneading device, etc. can be appropriately selected depending on the purpose. Examples of the kneading device include a Banbury mixer, an intermix, a kneader, a roll, etc. that are usually used for kneading rubber compositions.

[0134] The conditions for the heat-in are not particularly limited, and various conditions such as the heat-in temperature, heat-in time, and heat-in device can be appropriately selected depending on the purpose. Examples of the heat-in device include a heat-in roll mill typically used for heat-in of rubber compositions.

[0135] The extrusion conditions are not particularly limited, and various conditions such as extrusion time, extrusion speed, extrusion device, and extrusion temperature can be appropriately selected depending on the purpose. Examples of the extrusion device include an extruder typically used for extruding rubber compositions. The extrusion temperature can be appropriately determined.

[0136] The vulcanization apparatus, method, conditions, etc. are not particularly limited and can be appropriately selected depending on the purpose. Examples of vulcanization apparatus include a molding vulcanizer using a mold used for vulcanizing rubber compositions. The vulcanization temperature is, for example, about 100 to 190°C.

[0137] <Tire> The tire of this embodiment is characterized by including the above-described rubber composition for a tire. Since the tire of this embodiment includes the above-described rubber composition for a tire, it has a good balance of fuel economy, abrasion resistance, and productivity. The rubber composition is applied to the tread rubber of the tire.

[0138] The tire of this embodiment may be obtained by molding an unvulcanized rubber composition and then vulcanizing it, depending on the type of tire to be applied, or by molding a semi-vulcanized rubber that has been subjected to a pre-vulcanization step or the like and then further vulcanizing it. The tire of this embodiment is preferably a pneumatic tire, and the gas to be filled into the pneumatic tire may be normal air or air with an adjusted oxygen partial pressure, or an inert gas such as nitrogen, argon, or helium.

[0139] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples in any way.

[0140] <Method for Synthesizing Modified BR1> 283 g of cyclohexane, 50 g of 1,3-butadiene, 0.0057 mmol of 2,2-ditetrahydrofurylpropane, and 0.513 mmol of hexamethyleneimine (HMI) were added to a dried, nitrogen-purged, approximately 900 mL pressure-resistant glass vessel, and 0.57 mmol of n-butyllithium (BuLi) was then added. Polymerization was then carried out for 4.5 hours in a 50°C warm water bath equipped with a stirrer. The polymerization conversion rate was nearly 100%. Next, 0.100 mmol of tin tetrachloride was quickly added to this polymerization reaction system as a modifier (coupling agent), and the mixture was stirred at 50°C for an additional 30 minutes to carry out the modification reaction. Thereafter, 0.5 mL of an isopropanol solution of 2,6-di-t-butyl-p-cresol (BHT) (BHT concentration: 5% by mass) was added to the polymerization reaction system to terminate the reaction, and the mixture was further dried in a conventional manner to obtain a modified butadiene rubber having tin atoms (HMI-BR-Sn: modified BR1). １ The amount of vinyl bonds in the butadiene moiety was measured from the integral ratio of the H-NMR spectrum and was found to be 14%. The glass transition temperature (Tg) was calculated from the inflection point of the DSC curve and was found to be −95° C. The coupling rate was calculated from the ratio of the peak area on the highest molecular weight side to the entire area of ​​the molecular weight distribution curve by gel permeation chromatography (GPC) and was found to be 65%.

[0141] <Method for Synthesizing Modified BR2> A 5-L autoclave purged with nitrogen was charged with 2.4 kg of cyclohexane and 300 g of 1,3-butadiene under nitrogen. A catalyst prepared by reacting and aging the catalyst components (a cyclohexane solution of neodymium versatate (0.09 mmol), a toluene solution of methylalumoxane (MAO) (1.8 mmol), a toluene solution of diisobutylaluminum hydride (DIBAH) (5.0 mmol) and diethylaluminum chloride (0.18 mmol) and 1,3-butadiene (4.5 mmol) at 50°C for 30 minutes at 50°C was then added, and polymerization was carried out at 80°C for 60 minutes. The reaction conversion of 1,3-butadiene was nearly 100%. 200 g of this polymer solution was withdrawn, and a methanol solution containing 1.5 g of 2,4-di-tert-butyl-p-cresol was added to terminate the polymerization. The solvent was then removed by steam stripping, and the mixture was dried on a roll at 110°C to obtain a pre-modified polymer (butadiene rubber). Analysis of the obtained pre-modified polymer revealed that the 1,4-cis bond content was 97.0% and the 1,2-vinyl bond content was 1.1% by infrared spectroscopy (Morello method), the molecular weight distribution (Mw / Mn) determined by gel permeation chromatography (GPC) was 2.3, and the Mooney viscosity (ML １＋４ , 100°C) was 18. Furthermore, the remaining polymer solution was kept at a temperature of 60°C, and a toluene solution of 3-glycidoxypropyltrimethoxysilane (GPMOS) (4.5 mmol) was added, followed by reaction for 30 minutes. Subsequently, a toluene solution of tetra 2-ethylhexyl titanate (EHOTi) (13.5 mmol) was added, and the mixture was mixed for 30 minutes. Thereafter, a methanol solution containing 1.5 g of 2,4-di-tert-butyl-p-cresol was added, yielding 2.5 kg of a modified polymer solution. Next, the modified polymer solution was added to 20 L of an aqueous solution adjusted to pH 10 with sodium hydroxide, and a condensation reaction was carried out at 110°C for 2 hours, with removal of the solvent, and the mixture was dried on a roll at 110°C to yield a modified butadiene rubber (modified BR2). Analysis of the resulting modified butadiene rubber (modified BR2) revealed that the molecular weight distribution (Mw / Mn) determined by GPC was 2.7, and the Mooney viscosity (ML １＋４ , 125°C) was 43.

[0142] <Synthesis Method of Modified BR3> A cyclohexane solution of 1.4 kg, 250 g of 1,3-butadiene, and 0.285 mmol of 2,2-ditetrahydrofurylpropane was poured into a nitrogen-purged 5-L autoclave under nitrogen. 2.85 mmol of n-butyllithium (BuLi) was added to the autoclave, and polymerization was carried out for 4.5 hours in a 50°C warm water bath equipped with a stirrer. The reaction conversion of 1,3-butadiene was nearly 100%. A portion of the polymer solution was withdrawn into a methanol solution containing 1.3 g of 2,6-di-tert-butyl-p-cresol to terminate the polymerization. The solvent was then removed by steam stripping, and the resulting mixture was dried on a roll at 110°C to obtain unmodified polybutadiene. The microstructure (vinyl bond content) of the obtained unmodified polybutadiene was measured, and the vinyl bond content was found to be 30% by mass. The resulting polymer solution was maintained at 50°C without deactivating the polymerization catalyst, and 1129 mg (3.364 mmol) of N,N-bis(trimethylsilyl)aminopropylmethyldiethoxysilane with protected primary amino groups was added, and the modification reaction was carried out for 15 minutes. Subsequently, 8.11 g of tetrakis(2-ethyl-1,3-hexanediolato)titanium, a condensation accelerator, was added, and the mixture was stirred for an additional 15 minutes. 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, the solvent was removed and the protected primary amino groups were deprotected by steam stripping, and the rubber was dried on a heated roll heated to 110°C to obtain a primary amine-modified butadiene rubber (modified BR3). The microstructure (vinyl bond content) of the resulting modified butadiene rubber (modified BR3) was measured, and the vinyl bond content was found to be 30% by mass.

[0143] <Synthesis Method of Copolymer 1> 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 the polymerization reaction was carried out at 20°C for 2 hours. After the polymerization reaction, the polymerization was terminated by adding excess vinyl ethyl ether. The polymerization solution was poured into a large excess of methanol containing 2,6-di-t-butyl-p-cresol (BHT), and the precipitated polymer was recovered, washed with methanol, and then vacuum-dried at 50°C for 24 hours to obtain 67 parts by mass of Copolymer 1.

[0144] <Synthesis Method of Copolymer 2> 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 the polymerization reaction was carried out at 40°C for 2 hours. After the polymerization reaction, the polymerization was terminated by adding excess vinyl ethyl ether. The polymerization solution was poured into a large excess of methanol containing 2,6-di-t-butyl-p-cresol (BHT), and the precipitated polymer was recovered, washed with methanol, and then vacuum-dried at 50°C for 24 hours to obtain 60 parts by mass of Copolymer 2.

[0145] <Analysis of Copolymers> The molecular weight of each synthesized copolymer and the proportion of structural units derived from each monomer were measured by the following method. The results are shown in Table 1.

[0146] (1) Molecular Weight Measurement was performed using a gel permeation chromatography (GPC) system "HLC-8220" (manufactured by Tosoh Corporation) with two H-type columns "HZ-M" (manufactured by Tosoh Corporation) connected in series, with tetrahydrofuran as the solvent, at a column temperature of 40°C. A differential refractometer "RI-8320" (manufactured by Tosoh Corporation) was used as the detector. The weight average molecular weight (Mw) of the copolymer was measured as a polystyrene equivalent value.

[0147] (2) Proportion of structural units derived from each monomer The proportion of structural units derived from each monomer constituting the copolymer is １ It was determined by H-NMR spectrum measurement.

[0148]

[0149] <Preparation of Rubber Composition> Each component was blended and kneaded according to the formulation shown in Table 2 to prepare each rubber composition of the examples and comparative examples.

[0150] Each rubber composition further contained, as compounding ingredients other than the components shown in Table 2, 2 parts by mass of hardened fatty acid, 3.5 parts by mass of zinc oxide, 2.5 parts by mass of antioxidant (total amount of two types), 1 part by mass of resin, 1.4 parts by mass of sulfenamide vulcanization accelerator, and 1.05 parts by mass of sulfur per 100 parts by mass of the rubber component.

[0151] <Evaluation of Rubber Composition> The obtained rubber compositions were evaluated for fuel economy, abrasion resistance, and processability by the following methods. The results are shown in Table 2.

[0152] (3) Fuel Economy The loss tangent (tanδ) of a test piece made from the obtained rubber composition was measured using a viscoelasticity measuring device (TA Instruments) under conditions of a temperature of 50°C, a strain of 10%, and a frequency of 15 Hz. In addition, the modulus (M50) [MPa] at 50% strain of a test piece made from the obtained rubber composition was measured at room temperature. The evaluation results were indexed, with tanδ / M50 of Comparative Example 3 set to 100. The smaller the index value, the smaller the tanδ and the better the fuel economy.

[0153] (4) Abrasion Resistance In accordance with JIS K 6264-2:2005, sandpaper was attached to the grinding wheel using a Lambourn abrasion tester manufactured by Ueshima Seisakusho, and the amount of abrasion was measured at room temperature at a slip rate of 12%. The evaluation results were indexed, with the reciprocal of the amount of abrasion of Comparative Example 3 set as 100. A larger index value indicates a smaller amount of abrasion and better abrasion resistance.

[0154] (5) Processability Using an unvulcanized viscoelasticity measuring device "RPA2000 (manufactured by ALPHA TECHNOLOGIES)," the dynamic storage (shear) modulus G' was measured under conditions of a temperature of 130°C, a strain (torsion angle) of 1°, and a frequency of 100 cpm. The evaluation results were indexed, with the value of Comparative Example 3 set at 100. A smaller index value indicates a lower viscosity of the unvulcanized rubber and better processability, with a value of 145 or less being considered good.

[0155]

[0156] *1 NR: Natural rubber *2 BR: Butadiene rubber, manufactured by UBE Elastomers, product name "BR150L" *3 Modified BR1: Modified butadiene rubber synthesized by the above method *4 Modified BR2: Modified butadiene rubber synthesized by the above method *5 Modified SBR: Manufactured by ENEOS Material Corporation, product name "SL563", solution polymerization styrene-butadiene rubber, Sn modified *6 Modified BR3: Modified butadiene rubber synthesized by the above method *7 Copolymer 1: Copolymer of cyclopentene and norbornene-based compounds synthesized by the above method *8 Copolymer 2: Copolymer of cyclopentene and norbornene-based compounds synthesized by the above method *9 Carbon black 1: Carbon black having a cetyltrimethylammonium bromide (CTAB) adsorption specific surface area of ​​130 m ２ / g and dibutyl phthalate (DBP) absorption capacity of 140 mL / 100 g *10 Carbon black 2: N234, manufactured by Tokai Carbon Co., Ltd., trade name "SEAST 7HM", CTAB adsorption specific surface area = 119 m ２ / g

[0157] The results shown in Table 2 show that the rubber compositions of the examples containing a copolymer of cyclopentene and a norbornene-based compound and a modified polymer have a good balance of fuel economy, abrasion resistance, and processability.

[0158] On the other hand, the rubber compositions of Comparative Examples 1 and 2, which contain a copolymer of cyclopentene and a norbornene-based compound but do not contain a modified polymer, show significantly deteriorated processability, and the rubber composition of Comparative Example 5 shows significantly deteriorated wear resistance.

Claims

1. A rubber component and a filler, wherein the rubber component is a rubber composition represented by the following general formula (1): [In the formula, R １ ~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.], 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 a norbornene 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 copolymer of cyclopentene and a norbornene compound has a weight average molecular weight (Mw) of 200,000 to 1,000,000.

5. The rubber composition for tires according to claim 1, wherein the copolymer of cyclopentene and a norbornene compound has a content of structural units derived from cyclopentene of 20 to 75 mass %.

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

7. The rubber composition for tires according to claim 2, wherein the copolymer of cyclopentene and a norbornene compound has a content of structural units derived from dicyclopentadiene of 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 a tire according to claim 1, wherein the modified polymer is a modified butadiene rubber.

12. The rubber composition for a tire according to claim 1, wherein said filler comprises carbon black.

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

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