Polymer composition and rubber article

Abstract

Provided is a polymer composition capable of producing a tire product having high grip and high wear resistance. The polymer composition according to the present invention is characterized by comprising: a rubber component comprising a conjugated diene polymer (A-1); and at least one type selected from the group consisting of raw material component polymers comprising a C5 fraction comprising an aliphatic olefin, and raw material component polymers comprising a C9 fraction comprising an aromatic olefin and a C5 fraction comprising an aliphatic olefin. The conjugated diene polymer (A-1) contains a structural unit derived from a conjugated diene compound and a structural unit derived from an aromatic vinyl compound. The content of the structural unit derived from the aromatic vinyl compound is 5-60 mass% with respect to the total amount of the structural unit derived from the conjugated diene compound and the structural unit derived from the aromatic vinyl compound, and the content of the structural unit derived from the aromatic vinyl compound is 5-60 mass% with respect to the total amount of the structural unit derived from the conjugated diene compound and the structural unit derived from the aromatic vinyl compound. The content of discontinuous aromatic vinyl compound single chains in the aromatic vinyl compound is less than 40% by mass, and the content of aromatic vinyl compound long chains in which 8 or more aromatic vinyl compound units are linked is 10% by mass or less.

Description

TECHNICAL FIELD

[0001] The present application relates to a polymer composition. In addition, the present application relates to a rubber product formed using the polymer composition. BACKGROUND

[0002] In the past, a tire has been manufactured from a rubber composition containing a vulcanizing agent responsible for vulcanization, a filler such as carbon black, silica, an anti-aging agent for suppressing quality deterioration, a wax, and the like, and each component has been improved.

[0003] In recent years, various properties such as grip performance and rolling resistance have been required for a tire. For example, Patent Literature 1 describes a rubber composition containing a hydrogenated dicyclopentadiene (DCPD) series petroleum resin. It is found in Patent Literature 1 that a composition containing a specific hydrogenated DCPD series resin has high grip performance and low rolling resistance. In addition, Patent Literature 2 describes a rubber composition for a tire inner liner containing a C5, C9, or hydrogenated DCPD hydrocarbon resin. It is found that a composition composed of at least one of a DCPD-based polymer, a cyclopentadiene (CPD)-based polymer, a DCPD-styrene copolymer, a C5 homopolymer and copolymer resin, a C5-styrene copolymer resin, a terpene homopolymer or copolymer resin, a pinene homopolymer or copolymer resin, a C9 homopolymer and copolymer resin, a C5 / C9 copolymer resin, an alpha-methylstyrene homopolymer or copolymer resin, and combinations thereof has low air permeability.

[0004] PRIOR ART DOCUMENTS

[0005] PATENT LITERATURE

[0006] Patent Literature 1: Japanese Patent Application Laid-Open No. 2018-536044

[0007] Patent Literature 2: Japanese Patent Application Laid-Open No. 2018-193567 SUMMARY

[0008] However, the rubber compositions described in Patent Literatures 1 and 2 have room for improvement in the balance between grip performance and wear resistance.

[0009] Therefore, the present inventors and others have conducted intensive studies in order to solve the above problem, and as a result, surprisingly found that a tire manufactured using a polymer composition containing a specific rubber component and a specific raw material component polymer has high grip performance and high wear resistance. The present inventors and others have completed the present application based on the above insight.

[0010] That is, according to the present application, the following invention is provided.

[0011] [1] A polymer composition comprising:

[0012] a rubber component containing a conjugated diene polymer (A-1), and

[0013] at least one selected from a raw material component polymer containing a C5 fraction containing an aliphatic olefin, and a raw material component polymer containing a C9 fraction containing an aromatic olefin and a C5 fraction containing an aliphatic olefin;

[0014] The conjugated diene polymer (A-1) contains structural units derived from a conjugated diene compound and structural units derived from an aromatic vinyl compound,

[0015] The content of the structural units derived from the aromatic vinyl compound is 5 to 60 mass% relative to the total amount of the structural units derived from the conjugated diene compound and the structural units derived from the aromatic vinyl compound,

[0016] The content of the structural units derived from the aromatic vinyl compound, the aromatic vinyl compound is less than 40 mass% in a short chain of the aromatic vinyl compound, and more than 8 aromatic vinyl compound units are connected in a long chain of the aromatic vinyl compound is 10 mass% or less.

[0017] [2] The polymer composition according to [1], wherein the C5 fraction containing an aliphatic olefin contains at least one selected from the group consisting of piperyline, isoprene, 1-pentene, 2-pentene, 2-methyl-1-butene, 2-methyl-2-butene, and 3-methyl-1-butene.

[0018] [3] The polymer composition according to [1] or [2], wherein the C9 fraction containing an aromatic olefin contains at least one selected from the group consisting of vinyltoluene, α-methylstyrene, styrene, indene, and methylindene.

[0019] [4] The polymer composition according to any one of [1] to [3], wherein the proton amount per 1 molecule of the raw material component polymer satisfies the following condition:

[0020] 0 ≤ aromatic proton amount ≤ 95

[0021] 0 ≤ olefin proton amount ≤ 90.

[0022] [5] The polymer composition according to any one of [1] to [4], wherein the number average molecular weight (Mn) of the raw material component polymer is 300 g / mol or more and less than 3000 g / mol.

[0023] [6] The polymer composition according to any one of [1] to [5], wherein the content of the conjugated diene polymer (A-1) is 5 mass% or more of the total amount of the rubber component.

[0024] [7] The polymer composition according to any one of [1] to [6], wherein the conjugated diene-based polymer (A-1) has a nitrogen-containing group and a hydrocarbonoxysilyl group.

[0025] [8] The polymer composition according to any one of [1] to [7], further comprising a filler.

[0026] [9] A rubber product formed using the polymer composition according to any one of [1] to [8].

[0027]

[10] The rubber product according to [9], wherein the rubber product is selected from the group consisting of a tire, a tire tread, and a tire sidewall.

[0028] According to the present application, it is possible to provide a polymer composition that can produce a tire product having high grip performance and high wear resistance. Further, according to the present application, it is possible to produce a tire having high grip performance and high wear resistance. DETAILED DESCRIPTION

[0029] In the present specification, a numerical range recited in the form of "A to B" can be interpreted as including the numerical value A as a lower limit value and the numerical value B as an upper limit value.

[0030] [Polymer composition]

[0031] The polymer composition of the present application contains a rubber component and a raw material component polymer, and can further contain a filler and a silane coupling agent. A tire produced using the polymer composition of the present application has high grip performance and high wear resistance. Hereinafter, each component contained in the polymer composition is described in detail. Note that, in the present specification, the "rubber component" contained in the polymer composition refers to a polymer that can obtain a cured product exhibiting rubber elasticity by thermal curing. The cured product exhibits a property of deforming greatly with a small force at room temperature (for example, a deformation of 2 times or more in elongation when stretched at room temperature), and quickly returning to almost the original shape when the force is removed.

[0032] (Rubber component)

[0033] The rubber component used in the polymer composition contains at least a conjugated diene-based polymer (A-1), and can further contain other rubber components (hereinafter, also referred to simply as "other rubber components") other than A-1.

[0034] (Conjugated diene-based polymer (A-1))

[0035] The conjugated diene polymer (A-1) comprises structural units derived from conjugated diene compounds and structural units derived from aromatic vinyl compounds, and satisfies the following conditions (1) and (2). By satisfying the following conditions (1) and (2) with the conjugated diene polymer (A-1), tires with high grip and high wear resistance can be manufactured.

[0036] (1) The content of structural units from aromatic vinyl compounds is 5% to 60% by mass relative to the total amount of structural units from conjugated diene compounds and structural units from aromatic vinyl compounds. The content of structural units from aromatic vinyl compounds relative to the total amount of structural units from conjugated diene compounds and structural units from aromatic vinyl compounds is preferably 55% by mass or less, more preferably 50% by mass or less, and further preferably 10% by mass or more, more preferably 15% by mass or more. It should be noted that the proportion of structural units from aromatic vinyl compounds in the polymer is determined by... 1 The value was determined by H-NMR.

[0037] (2) Relative to the content of structural units from aromatic vinyl compounds, the discontinuous aromatic vinyl compound single chains are less than 40% by mass, preferably 38% by mass or less, but may be 1% by mass or more, 5% by mass or more, 10% by mass or more, 15% by mass or more, or 20% by mass or more, and the long chains of aromatic vinyl compounds with 8 or more aromatic vinyl compound units are 10% by mass or less, preferably 5% by mass or less, but may be 0.1% by mass or more, 0.2% by mass or more, or 0.5% by mass or more. The chain of the aromatic vinyl compound is calculated by analyzing the conjugated diene polymer by gel permeation chromatography after ozone decomposition [Tanaka et al., Polymer, 22, 1721 (1981)].

[0038] The conjugated diene polymer (A-1) preferably has a nitrogen-containing group and a hydroxyl group. It should be noted that "hydroxyl group" is a group in which at least one hydroxyl group is bonded to a silicon atom, and refers to the group represented by the following formula (1).

[0039]

[0040] (In equation (1), R) 1 and R 2 Each is an independent hydrocarbon group. i is an integer from 1 to 3. When i is 1, the multiple R groups in the formula... 2 Same or different. When i is 2 or 3, multiple R in the formula 1 Same or different. (This indicates a bonding site.)

[0041] As the nitrogen-containing group, for example, a primary amino group, a secondary amino group, a tertiary amino group, a protected primary amino group, a protected secondary amino group, an imino group, an imidazolyl group, an azasilolyl group, a silazane structure, and the like can be given, and a primary amino group, a protected primary amino group, an imino group are preferable, and a primary amino group is more preferable. In addition, as the hydrocarbyloxysilyl group, a group represented by the above formula (1) in which i is 3, R 1 a group represented by the above formula (1) in which i is 2, R 1 and R 2 each independently a group represented by a linear or branched alkyl group having 1 to 6 carbon atoms, and the like, and a triethoxysilyl group or a diethoxymethylsilyl group is preferable, and a triethoxysilyl group is more preferable. By the conjugated diene-based polymer (A-1) having a nitrogen-containing group and a hydrocarbyloxysilyl group, high grip performance and high abrasion resistance become good.

[0042] In the case where the nitrogen-containing group and the hydrocarbyloxysilyl group are introduced into the conjugated diene-based polymer (A-1), the nitrogen-containing group and the hydrocarbyloxysilyl group can be introduced respectively, or can be introduced simultaneously. The specific introduction method of the nitrogen-containing group and the hydrocarbyloxysilyl group is described in detail in the items of <Polymerization Process> to <Modification Process>.

[0043] The nitrogen-containing group and the hydrocarbyloxysilyl group can be introduced to the main chain end of the polymer, or can be introduced to both the side chain and the main chain end of the polymer. Among these, from the aspect that a tire having high grip performance and high abrasion resistance can be manufactured, it is preferable that at least the specific structure is introduced to the main chain end. Herein, in the present specification, the "main chain" of the polymer refers to the longest "stem" portion in the atomic chain of the polymer. The "side chain" of the polymer refers to the portion branching from the "stem" of the polymer.

[0044] The content of the conjugated diene-based polymer (A-1) is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 20% by mass or more, with respect to the total amount of the rubber component, and can be 100% by mass or less, can be 90% by mass or less, or can be 80% by mass or less. If the content of the conjugated diene-based polymer (A-1) is within the above numerical range, a tire having high grip performance and high abrasion resistance can be manufactured.

[0045] (Method for producing conjugated diene-based polymer (A-1))

[0046] The conjugated diene-based polymer (A-1) can be obtained by copolymerizing a conjugated diene compound and an aromatic vinyl compound. Further, a nitrogen-containing group and a hydrocarbyloxy silyl group can be introduced into the conjugated diene-based polymer (A-1) by reacting a compound having a nitrogen-containing group and a compound having a hydrocarbyloxy silyl group with the conjugated diene-based polymer (A-1), or by reacting a compound having a nitrogen-containing group and a hydrocarbyloxy silyl group with the conjugated diene-based polymer (A-1). These reactions are not particularly limited, and, for example, the conjugated diene-based polymer (A-1) is preferably produced by a method including a polymerization step. Hereinafter, matters related to the manner of the present disclosure are described in detail.

[0047] < Polymerization step >

[0048] This step is a step of polymerizing monomers including a conjugated diene compound and an aromatic vinyl compound to obtain a conjugated diene-based polymer having a living terminal. As the conjugated diene compound used in the polymerization, for example, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene, 1,3-pentadiene, and the like can be given. These conjugated diene compounds can be used alone or in combination of two or more.

[0049] The content of the structural unit derived from the conjugated diene compound can be appropriately adjusted according to the condition (content of the structural unit derived from the aromatic vinyl compound) of the above (1). The amount of the conjugated diene compound used is preferably 40% by mass to 95% by mass, more preferably 45% by mass to 95% by mass, and even more preferably 50% by mass to 95% by mass, relative to the total amount of the conjugated diene compound and the aromatic vinyl compound used in the polymerization.

[0050] As the aromatic vinyl compound used in the polymerization, for example, styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, α-methylstyrene, 2,4-dimethylstyrene, 2,4-diisopropylstyrene, 4-tert-butylstyrene, divinylbenzene, t-butoxy styrene, vinylbenzyl dimethylamine, (4-vinylbenzyl)dimethylaminoethyl ether, N,N-dimethylaminoethylstyrene, vinylpyridine, and the like can be given. These aromatic vinyl compounds can be used alone or in combination of two or more.

[0051] As the monomers used in the above polymerization, a compound other than the conjugated diene compound and the aromatic vinyl compound (hereinafter, also referred to as "a third monomer") can also be used. As the third monomer, for example, acrylonitrile, methyl methacrylate, ethyl methacrylate, methyl acrylate, ethyl acrylate, hydroxyethyl methacrylate, and hydroxyethyl acrylate, and the like can be given. These third monomers can be used alone or in combination of two or more.

[0052] The amount of the third monomer used is preferably 25% by mass or less, more preferably 15% by mass or less, and also can be 0% by mass or more, relative to the total amount of the monomers used in the polymerization.

[0053] As the polymerization method, any one of a solution polymerization method, a gas phase polymerization method, and a bulk polymerization method can be used, and a solution polymerization method is particularly preferable. Also, as the polymerization form, any one of a batch method and a continuous method can be used, and a batch method is preferable. In the case where a solution polymerization method is used, as one example of a specific polymerization method, a method in which monomers containing a conjugated diene compound and an aromatic vinyl compound are polymerized in an organic solvent in the presence of a polymerization initiator and a randomizing agent, if necessary, can be given.

[0054] As the polymerization initiator, an alkali metal compound can be used. As specific examples of the alkali metal compound, for example, alkyl lithium such as methyllithium, ethyllithium, n-propyllithium, n-butyllithium, sec-butyllithium, t-butyllithium; 1,4-dilithiobutane, phenyllithium, stilbenelithium, naphthyllithium, 1,3-bis(l-lithio-l,3-dimethylpentyl)benzene, 1,3-phenylenebis(3-methyl-l-phenylpentylidene)dilithium, naphthylsodium, naphthylpotassium, ethoxypotassium, and the like can be given. Among these, a lithium compound is preferable.

[0055] As the alkali metal compound, a compound having a functional group that interacts with silica (hereinafter, also referred to as "an initiation modifier") can also be used in the above polymerization. By performing the polymerization in the presence of the initiation modifier, a functional group that interacts with silica can be introduced to the polymerization initiation terminal of the conjugated diene-based polymer (A-1). Note that the "functional group that interacts with silica" in the present specification refers to a group having an element such as nitrogen, sulfur, phosphorus, oxygen, and the like that interacts with silica. The "interaction" refers to the formation of a covalent bond between molecules, or the formation of an intermolecular force weaker than a covalent bond (for example, an electromagnetic force such as ion-dipole interaction, dipole-dipole interaction, hydrogen bonding, van der Waals force, and the like that acts between molecules).

[0056] The initiating modifier is preferably an alkali metal compound containing nitrogen. Among them, a mixture of an alkali metal compound not containing nitrogen and a secondary amine compound can be given. In the mixture, as the secondary amine compound, for example, dimethylamine, diethylamine, dipropylamine, dibutylamine, dodecamethyleneimine, N,N'-dimethyl-N'-trimethylsilyl-1,6-diaminohexane, piperidine, pyrrolidine, hexamethyleneimine, heptamethyleneimine, dicyclohexylamine, N-methylbenzylamine, di(2-ethylhexyl)amine, diallylamine, morpholine, N-(trimethylsilyl)piperazine, N-(tert-butyldimethylsilyl)piperazine, 1,3-bis(trimethylsilyl)-1,3,5-triazinane, N-trimethylsilylpiperazine, 1,3,3-trimethyl-6-azabicyclo[3.2.1]octane, 1-propyl-3-azabicyclo[3.2.2]nonane and the like chain or cyclic secondary amine compounds can be given. As the alkali metal compound not containing nitrogen, alkyl lithium is preferably used.

[0057] It should be noted that when the polymerization is performed in the presence of the above mixture, the alkali metal compound not containing nitrogen and the secondary amine compound can be mixed in advance and the mixture thereof can be added to the polymerization system to perform the polymerization. Alternatively, the alkali metal compound not containing nitrogen and the secondary amine compound can be added to the polymerization system and mixed in the polymerization system to perform the polymerization. By performing the polymerization in the presence of the mixture of the alkali metal compound not containing nitrogen and the secondary amine compound, a nitrogen-containing group can be introduced to the terminal of the main chain of the conjugated diene polymer (A-1).

[0058] The amount of the polymerization initiator used (the total amount in the case of using two or more) is preferably 0.01 to 20 mmol, more preferably 0.05 to 15 mmol, relative to 100 g of the monomer used in the synthesis of the conjugated diene polymer (A-1). In addition, the proportion of the initiating modifier used can be 10 to 100 mol% relative to the total amount of the polymerization initiator (preferably an alkali metal compound) used in the polymerization of the above monomer.

[0059] Randomizing agents can be used for purposes such as adjusting the vinyl bond content (indicating the percentage of vinyl bonds in a polymer) and adjusting the ratio of single-chain to long-chain aromatic vinyl compounds. Examples of randomizing agents include at least one potassium salt selected from dimethoxybenzene, tetrahydrofuran, dimethoxyethane, diethylene glycol dibutyl ether, diethylene glycol dimethyl ether, 2,2-di(tetrahydrofuranyl)propane, 2-(2-ethoxyethoxy)-2-methylpropane, triethylamine, pyridine, N-methylmorpholine, tetramethylethylenediamine, etc.; potassium alkanol, potassium phenolate, potassium salts of organic carboxylic acids, potassium salts of organic sulfonic acids, and potassium salts of organic phosphite fractions. The randomizing agents exemplified above can be used alone or in combination of two or more. Potassium salts are preferred, and combinations of potassium salts with the aforementioned randomizing agents other than potassium salts are more preferred.

[0060] As an organic solvent used in polymerization, any organic solvent that is inactive in the reaction can be used, such as aliphatic hydrocarbons, alicyclic hydrocarbons, and aromatic hydrocarbons. Among these, hydrocarbons with 3 to 8 carbon atoms are preferred. Specific examples include propane, n-butane, isobutane, n-pentane, isopentane, n-hexane, cyclohexane, propylene, 1-butene, isobutene, trans-2-butene, cis-2-butene, 1-pentyne, 2-pentyne, 1-hexene, 2-hexene, benzene, toluene, xylene, ethylbenzene, heptane, cyclopentane, methylcyclopentane, methylcyclohexane, 1-pentene, 2-pentene, and cyclohexene. It should be noted that one or more organic solvents can be used alone or in combination.

[0061] When using solution polymerization, from the viewpoint of maintaining a balance between productivity and ease of polymerization control, the monomer concentration in the reaction solvent is preferably 5-50% by mass, more preferably 10-30% by mass. The polymerization temperature is preferably -20°C to 150°C, more preferably 0-120°C. Furthermore, the polymerization reaction is preferably carried out at a pressure sufficient to substantially retain the monomer in the liquid phase. Such pressure can be obtained by methods such as pressurizing the reactor using a gas that is inactive in the polymerization reaction.

[0062] Conjugated diene polymers with active ends can be obtained through such polymerization reactions. The preferred weight-average molecular weight (Mw) of the obtained conjugated diene polymer, calculated from polystyrene using gel permeation chromatography (GPC), is 5.0 × 10⁻⁶. 4 ~1.0×10 6 If Mw is less than 5.0 × 10 4 If the tensile strength, low heat generation, and wear resistance of the cross-linked polymer tend to decrease, especially if the value is greater than 1.0 × 10⁻⁶. 6there is a tendency that the processability of the polymer composition obtained using the conjugated diene-based polymer decreases easily. More preferably, 8.0 x 10 4 ~ 9.0 x 10 6 Further preferably, 1.0 x 10 5 ~ 8.0 x 10 5 .

[0063] For the conjugated diene-based polymer having a living terminal, the content of the vinyl bond in the butadiene unit (hereinafter, also referred to as "vinyl content") is preferably 10% by mass or more, more preferably 20% by mass or more, and further preferably 30% by mass or more. In addition, the vinyl content is preferably 70% by mass or less, more preferably 68% by mass or less, and further preferably 65% by mass or less. If the vinyl content is 10% by mass or more, there is a tendency that the grip property becomes high, and if it is 70% by mass or less, there is a tendency that the abrasion resistance of the obtained vulcanizate becomes high. It should be noted that the "vinyl content" in the present specification is a value indicating the proportion of the structural unit having a 1,2-bond in the conjugated diene-based polymer with respect to all the structural units of butadiene, and is a value determined by 1 H-NMR.

[0064] <Modification Step>

[0065] The production method of the conjugated diene-based polymer (A-1) can include a modification step in addition to the above polymerization step. In this step, the living terminal possessed by the conjugated diene-based polymer obtained in the above polymerization step is reacted with a compound having a hydrocarbyloxysilyl group. A conjugated diene-based polymer having a hydrocarbyloxysilyl group can be obtained by this reaction. It should be noted that the "living terminal" in the present specification refers to a portion constituting a carbon-metal bond (more specifically, a carbanion) present at one end of a molecular chain.

[0066] As the compound having a hydrocarbonoxysilyl group, a compound having both a nitrogen-containing group and a hydrocarbonoxysilyl group in one molecule (hereinafter also referred to as "stop end modifier") is preferable. As the stop end modifier, an amino group-containing alkoxysilane compound, an imino group-containing alkoxysilane compound, an imidazole group-containing alkoxysilane compound, an alkoxysilane compound having an azasilolane structure, and the like can be used. As the amino group-containing alkoxysilane compound, for example, N,N-bis(trimethylsilyl)aminopropylmethyldimethoxysilane, N,N-bis(trimethylsilyl)aminopropyltrimethoxysilane, N,N-bis(trimethylsilyl)aminopropyltriethoxysilane, N,N-bis(trimethylsilyl)aminopropylmethyldiethoxysilane, N,N-bis(trimethylsilyl)aminoethyltrimethoxysilane, N,N-bis(trimethylsilyl)aminoethyltriethoxysilane, N,N-bis(trimethylsilyl)aminoethylmethyldimethoxysilane, N,N-bis(trimethylsilyl)aminoethylmethyldiethoxysilane, and the like can be given.

[0067] Further, as other examples of the amino group-containing alkoxysilane compound, tri(2-triethoxysilyl ethyl)amine, tri(3-triethoxysilyl propyl)amine, tri(5-triethoxysilyl pentyl)amine, N,N,N',N'-tetra(2-triethoxysilyl ethyl)-l,2-diaminoethane, N,N,N',N'-tetra(3-triethoxysilyl propyl)-l,3-diaminopropane, and N,N,N-tris(triethoxysilyl)propylamine, and compounds obtained by substituting the alkyl group, alkanediyl group in these compounds with an alkyl group having 1 to 6 carbon atoms, an alkanediyl group having 1 to 6 carbon atoms, respectively, can be given.

[0068] As other examples of the imino group-containing alkoxysilane, for example, N-(l,3-dimethylbutylidene)-3-(triethoxysilyl)-l-propanamine, N-(l-methylpropylidene)-3-(triethoxysilyl)-l-propanamine, N-(4-N,N-dimethylaminobenzylidene)-3-(triethoxysilyl)-l-propanamine, N-(cyclohexylidene)-3-(triethoxysilyl)-l-propanamine, and tri-methoxysilyl compounds, methyl diethoxysilyl compounds, ethyl dimethoxysilyl compounds, 3-hexamethyleneiminopropyltrimethoxysilane, and 3-hexamethyleneiminopropylmethyldimethoxysilane, corresponding to these triethoxysilyl compounds, and compounds obtained by substituting the alkyl group, alkylene group in the above compounds with an alkyl group having 1 to 6 carbon atoms, an alkylene group having 1 to 6 carbon atoms, can be given.

[0069] As other examples of the alkoxysilane having an imidazolyl group, for example, N-(3-trimethoxysilylpropyl)-4,5-dihydroimidazole, N-(3-triethoxysilylpropyl)-4,5-dihydroimidazole, N-(3-trimethoxysilylpropyl)-4,5-imidazole, N-(3-triethoxysilylpropyl)-4,5-imidazole, and N,N-bis(triethoxysilylpropyl)aminopropyl-1-imidazole, and a compound obtained by substituting the alkyl group and alkanediyl group in the above compounds with an alkyl group and alkanediyl group having 1 to 6 carbon atoms can be given.

[0070] As the alkoxysilane compound having an azasilolane structure, for example, 1-trimethylsilyl-2,2-dimethoxy-1-aza-2-silolane, 1-triethylsilyl-2,2-diethoxy-1-aza-2-silolane, 2,2-dimethoxy-1-(3-trimethoxysilylpropyl)-1,2-azasilolane, 2,2-dimethoxy-1-phenyl-1,2-azasilolane, 2-(2,2-dimethoxy-1,2-azasilolane-1-yl)-N,N-diethylethan-1-amine, and the like can be given.

[0071] As the stop end modifier, one of these can be used alone, or two or more can be used in combination.

[0072] The reaction of the polymerization-active end with the stop end modifier is preferably performed in the form of a solution reaction. This solution reaction can be performed using a solution containing unreacted monomers after the polymerization reaction, or can be performed after the conjugated diene-based polymer contained in the solution is separated and dissolved in a suitable solvent such as cyclohexane. In addition, the above reaction can be performed using either of a batch system and a continuous system. At this time, the method of adding the end modifier is not particularly limited, and methods such as a method of adding all at once, a method of adding in batches, a method of adding continuously, and the like can be given.

[0073] At the above reaction, the amount of the stop end modifier used is appropriately set according to the kind of the compound used in the reaction, and is preferably 0.1 molar equivalent or more, and more preferably 0.3 molar equivalent or more, with respect to the metal atom participating in the polymerization reaction possessed by the polymerization initiator. By making the amount of the stop end modifier used at the above reaction 0.1 molar equivalent or more, the modification reaction can be made to proceed sufficiently, and the dispersibility of the filler can be appropriately improved. In addition, in order to avoid excessive addition of the stop end modifier, the amount of the stop end modifier used is preferably 1.5 molar equivalent or less, and more preferably 1.2 molar equivalent or less, with respect to the metal atom participating in the polymerization reaction possessed by the polymerization initiator.

[0074] The reaction temperature of the above reaction is usually the same as the temperature of the polymerization reaction, and is preferably from -20°C to 150°C, more preferably from 0 to 120°C. If the reaction temperature is too low, there is a tendency for the viscosity of the modified conjugated diene polymer to increase. On the other hand, if the reaction temperature is too high, the polymerization active terminal becomes easily deactivated. The reaction time is preferably from 1 minute to 5 hours, more preferably from 2 minutes to 1 hour.

[0075] It should be noted that, in the production of the conjugated diene polymer, the treatment of reacting the polymerization active terminal with a coupling agent can be performed for the purpose of increasing the Mooney viscosity, the cold flow property, or the like of the polymer. Hereinafter, the reaction of the polymerization active terminal with the coupling agent will also be referred to as "coupling reaction". The reaction using the coupling agent can be performed before or after the reaction of the polymerization active terminal with the terminal-stopping modifier, or can be performed simultaneously with the reaction of the polymerization active terminal with the terminal-stopping modifier. In addition, the terminal-stopping modifier can not be used, and only the coupling agent can be used. As specific examples of the coupling agent, 2,4-toluene diisocyanate, diphenylmethane diisocyanate, N,N,N',N'-tetramethylphthalamide, silicon tetrachloride, N,N,N',N'-tetramethyl-4,4'-benzophenone, tin tetrachloride, and the like can be given.

[0076] In addition, when a compound having a protective group (trimethylsilyl group or the like) is used as the terminal-stopping modifier, for the conjugated diene polymer having the protective group from the terminal-stopping modifier, a polymer obtained by hydrogenating part or all of the protective group can be used as the conjugated diene polymer in a later process. In addition, when a compound containing a protective group is used as the terminal-stopping modifier, the conjugated diene polymer modified by the terminal-stopping modifier can be further reacted with an onium salt generator. In this case, as the conjugated diene polymer, a polymer having an onium salt structure at the terminal of the polymer can be obtained. By the conjugated diene polymer having the onium salt structure, the shape retention property of the crosslinked body obtained using the polymer composition can be improved, and this is preferred from this aspect.

[0077] In order to separate the conjugated diene polymer contained in the reaction solution, for example, a publicly known desolventizing method such as stripping and a drying operation such as heat treatment can be performed. The weight average molecular weight (Mw) of the conjugated diene polymer in terms of polystyrene based on gel permeation chromatography (GPC) is preferably from 1.0 x 104 to 1.0 x 107, more preferably from 1.2 x 104 to 1.0 x 106, further preferably from 1.5 x 104 to 1.0 x 105, and particularly preferably from 2.0 x 104 to 8.0 x 105. 5 If the Mw is less than 1.0 x 104, there is a tendency for the shape stability, the tensile strength, and the abrasion resistance of the crosslinked body to easily decrease. If the Mw is more than 1.0 x 107, there is a tendency for the shape stability, the tensile strength, and the abrasion resistance of the crosslinked body to easily decrease. 5 If the Mw is less than 1.0 x 104, there is a tendency for the shape stability, the tensile strength, and the abrasion resistance of the crosslinked body to easily decrease. If the Mw is more than 1.0 x 107, there is a tendency for the shape stability, the tensile strength, and the abrasion resistance of the crosslinked body to easily decrease. 5 If the Mw is less than 1.0 x 104, there is a tendency for the shape stability, the tensile strength, and the abrasion resistance of the crosslinked body to easily decrease. If the Mw is more than 1.0 x 107, there is a tendency for the shape stability, the tensile strength, and the abrasion resistance of the crosslinked body to easily decrease. 5 If the Mw is less than 1.0 x 104, there is a tendency for the shape stability, the tensile strength, and the abrasion resistance of the crosslinked body to easily decrease. If the Mw is more than 1.0 x 107, there is a tendency for the shape stability, the tensile strength, and the abrasion resistance of the crosslinked body to easily decrease. If the Mw is less than 1.0 x 104, there is a tendency for the shape stability, the tensile strength, and the abrasion resistance of the crosslinked body to easily decrease. If the Mw is more than 1.0 x 107, there is a tendency for the shape stability, the tensile strength, and the abrasion resistance of the crosslinked body to easily decrease.6 If Mw is greater than 1.5 x 10 6 then there is a tendency for the processability of the polymer composition to easily decrease. The Mw of the conjugated diene-based polymer is more preferably 1.3 x 10 6 Further preferably, the Mw is 1.0 x 10 6

[0078] As described above, the conjugated diene-based polymer A-1 can be obtained by the method including the <Polymerization Step>. In addition, the conjugated diene-based polymer A-1 having a nitrogen-containing group can be obtained by using an initiation modifier in the <Polymerization Step>. By further going through the <Modification Step>, the conjugated diene-based polymer A-1 having a nitrogen-containing group and a hydrocarbonoxysilyl group can be obtained.

[0079] (Other Rubber Component)

[0080] As the other rubber component, there is no particular limitation as long as the above-described conditions for the conjugated diene-based polymer (A-1) are not satisfied. As the other rubber component, for example, a butadiene rubber (BR, such as high-cis BR in which the cis-1,4 bond is 90% or more), an emulsion-polymerized or solution-polymerized styrene-butadiene rubber (SBR), a styrene-isoprene-butadiene rubber, a styrene-isoprene rubber, a partially hydrogenated styrene-butadiene rubber, a styrene-a-methylstyrene-butadiene rubber, an ethylene-propylene-diene rubber, a natural rubber (NR), an isoprene rubber (IR), an isoprene-butadiene rubber, and a halogenated isoprene rubber, a liquid rubber, an ethylene-propylene rubber (EPM), an ethylene-propylene-diene rubber (EPDM), a silicone rubber, and the like can be mentioned.

[0081] As the liquid rubber, a liquid polyisoprene (liquid IR), a liquid polybutadiene (liquid BR), a liquid styrene-butadiene copolymer (liquid SBR), a liquid ethylene-propylene copolymer (liquid EP), and the like can be mentioned. For example, a liquid SBR having a weight average molecular weight of 1000 to 100000, preferably 2000 to 80000 can be used. Note that the weight average molecular weight referred to here is the weight average molecular weight converted to polystyrene by gel permeation chromatography (GPC) analysis. The liquid rubber used in the present disclosure refers to a liquid rubber having fluidity at 23°C.

[0082] The content of the other rubber component can be appropriately adjusted depending on the content of the conjugated diene-based polymer (A-1). For example, the content of the other rubber component is preferably 95% by mass or less, more preferably 90% by mass or less, further preferably 85% by mass or less, with respect to the total amount of the rubber components, and can be 0% by mass, can be 5% by mass or more, and can be 10% by mass or more. ​

[0083] The content of the rubber component is preferably 20 to 70 mass%, more preferably 25 to 65 mass%, and further preferably 30 to 60 mass% relative to the total amount of the polymer composition. If the content of the rubber component is within the above numerical range, a tire having high grip performance and high wear resistance can be produced.

[0084] (Polymer of raw material component)

[0085] The polymer of raw material component used in the polymer composition is at least one selected from the group consisting of a polymer of raw material component containing a C5 fraction containing an aliphatic olefin and a polymer of raw material component containing a C9 fraction containing an aromatic olefin and a C5 fraction containing an aliphatic olefin. Note that, in the present application, the "polymer of raw material component" refers to a polymer obtained by polymerizing a raw material component (C5 fraction containing an aliphatic olefin, etc.). By using such a polymer of raw material component, a tire having high grip performance and high wear resistance can be produced.

[0086] The C5 fraction containing an aliphatic olefin is a fraction having a boiling point range of about 20 to 110°C in a fraction obtained by thermal cracking of a petroleum-based material (naphtha, etc.), and mainly contains compounds having 4 to 5 carbon atoms. As the aliphatic olefin in the C5 fraction, for example, piperitone, isoprene, 1-pentene, 2-pentene, 2-methyl-1-butene, 2-methyl-2-butene, 3-methyl-1-butene, 1,2-pentadiene, and 3-methyl-1,2-butadiene, etc. can be included, and two or more kinds can be included.

[0087] The C9 fraction containing an aromatic olefin is a fraction having a boiling point range of about 100 to 280°C in a fraction obtained by thermal cracking of a petroleum-based material (naphtha, etc.), and mainly contains compounds having 8 to 10 carbon atoms. As the aromatic olefin in the C9 fraction, for example, vinyltoluene, α-methylstyrene, styrene, indene, methylindene, etc. can be included, and two or more kinds can be included.

[0088] The raw material component can further include other components in addition to the C5 fraction containing an aliphatic olefin and the C9 fraction containing an aromatic olefin. As the other components, non-polymerizable hydrocarbons that do not have a polymerizable group and do not participate in polymerization can be included. As the non-polymerizable hydrocarbons, for example, saturated hydrocarbons (alkanes, cycloalkanes, etc.), aromatic hydrocarbons (benzene, methyl ethylbenzene, toluene, etc.), etc. can be included.

[0089] The polymerization method of the raw material component is not particularly limited, and can be performed by a publicly known method. As the polymerization method, for example, thermal polymerization, cationic polymerization, etc. can be included, and thermal polymerization is preferred.

[0090] The reaction temperature of the thermal polymerization is not particularly limited, and for example, is preferably 250°C to 300°C, more preferably 260°C to 290°C.

[0091] The reaction time of the thermal polymerization is not particularly limited, and for example, is preferably 1 hour to 10 hours, more preferably 2 hours to 7 hours, further preferably 3 hours to 5 hours.

[0092] The number average molecular weight (Mn) of the raw material component polymer is not particularly limited, and for example, is preferably 300 g / mol or greater and less than 3000 g / mol, more preferably 400 g / mol or greater, further preferably 500 g / mol or greater, more further preferably 600 g / mol or greater, more further preferably 700 g / mol or greater, and more preferably 2500 g / mol or less, further preferably 2000 g / mol or less, more further preferably 1700 g / mol or less, particularly preferably 1500 g / mol or less, most preferably 1300 g / mol or less.

[0093] If the number average molecular weight (Mn) of the raw material component polymer is within the above numerical range, the compatibility with the rubber component becomes good, and the viscoelasticity characteristics, which are an index of high grip performance, become good.

[0094] Note that the number average molecular weight (Mn) of the raw material component polymer can be measured by a method of GPC (gel permeation chromatography) analysis that is conventionally known. In the present application, the value is measured by the method described in the Examples below.

[0095] The amount of protons per 1 molecule of the raw material component polymer preferably satisfies the following conditions: 0 ≤ amount of aromatic protons ≤ 95, 0 ≤ amount of olefin protons ≤ 90; more preferably satisfies 0 ≤ amount of aromatic protons ≤ 80, 0 ≤ amount of olefin protons ≤ 50; further preferably satisfies 0 ≤ amount of aromatic protons ≤ 50, 0 ≤ amount of olefin protons ≤ 30; particularly preferably satisfies 0 ≤ amount of aromatic protons ≤ 20, 0 ≤ amount of olefin protons ≤ 10.

[0096] If the amount of protons per 1 molecule of the raw material component polymer satisfies the above conditions, the compatibility with the rubber component becomes good, and the viscoelasticity characteristics, which are an index of high grip performance, become good.

[0097] Note that the amount of protons per 1 molecule of the raw material component polymer can be measured by a method of H NMR that is conventionally known. In the present application, the value is measured by the method described in the Examples below. 1 H NMR to measure. In the present application, the value is measured by the method described in the Examples below.

[0098] The raw material component polymer can be subjected to hydrogenation. The method of hydrogenation of the raw material component polymer is not particularly limited and can be performed by a method known in the art. The method of hydrogenation can be performed, for example, by contacting the raw material component polymer with a hydrogenation catalyst in the presence of molecular hydrogen.

[0099] The hydrogenation catalyst is not particularly limited and examples thereof include nickel-based catalysts, molybdenum-based catalysts, cobalt-based catalysts, palladium-based catalysts, platinum-based catalysts, and the like.

[0100] The reaction temperature of hydrogenation is not particularly limited and is preferably, for example, from 150°C to 320°C, more preferably from 160°C to 300°C.

[0101] The reaction pressure of hydrogenation is not particularly limited and is preferably, for example, from 2 MPa to 30 MPa, more preferably from 3 MPa to 25 MPa.

[0102] The reaction time of hydrogenation is not particularly limited and is preferably, for example, from 1 hour to 10 hours, more preferably from 2 hours to 7 hours, further preferably from 3 hours to 5 hours.

[0103] (Other resins)

[0104] The polymer composition can further include other resins in addition to the raw material component polymer. As the other resins, for example, rosin-based resins, terpene-based resins, coumarone-based resins, phenolic-based resins, and the like can be given.

[0105] (Filler)

[0106] As the filler, silica, carbon black, and an inorganic compound represented by the following formula (2) (hereinafter, also referred to as "inorganic compound (M)"), a reinforcing fiber (for example, inorganic fibers such as glass fibers or carbon fibers, organic fibers such as nylon or polyester), and barium sulfate, and the like can be given. Among these, at least one selected from the group consisting of silica, carbon black, and the inorganic compound (M) is preferably used.

[0107] nM 1 • mSiO k • iH2O (2)

[0108] (In formula (2), M 1 is at least one selected from the group consisting of a specific metal selected from any one of aluminum, magnesium, titanium, and calcium, an oxide of the specific metal, a hydroxide of the specific metal, a hydrate of the oxide of the specific metal, and a hydrate of the hydroxide of the specific metal. n is an integer of 1 to 5, m is an integer of 0 to 10, k is an integer of 2 to 5, and i is an integer of 0 to 10.)

[0109] (Silica)

[0110] As the silica, there is no particular limitation, and for example, dry process silica, wet process silica, colloidal silica, and precipitated silica, etc. can be mentioned. Among these, wet process silica in which aqueous silicic acid is the main component is preferred. These silicas can be used alone or in combination of two or more. In addition, the BET specific surface area of the silica (determined in accordance with ISO 5794 / 1) is preferably in the range of 40 to 350 m 2 / g, further preferably in the range of 80 to 300 m 2 / g, particularly preferably in the range of 120 to 250 m 2 / g. Silica having a BET specific surface area in this range has the advantage of being able to have both rubber reinforcing properties and dispersibility in the conjugated diene-based polymer (A-1). As such silica, commercially available products such as "Nipsil AQ" (BET specific surface area = 205 m 2 / g) and "Nipsil KQ" manufactured by Nippon Silica Chemical Co., Ltd., "Ultrasil VN3" (BET specific surface area = 175 m 2 / g) manufactured by Degussa, etc. can be used.

[0111] Two or more kinds of silica having different specific surface areas can also be used in combination in the polymer composition. Specifically, a first silica having a CTAB (cetyltrimethylammonium bromide) specific surface area of 180 m 2 / g or more, a BET specific surface area of 185 m 2 / g or more, and an aggregate size of 45 nm or more, and a second silica having a CTAB specific surface area of 95 m 2 / g or less, and a BET specific surface area of 100 m 2 / g or less can be used in combination. Note that the CTAB specific surface area of the silica can be determined in accordance with ASTM D3765-92.

[0112] The polymer composition can contain a first silica having a CTAB specific surface area of 180 m 2 / g or more, a BET specific surface area of 185 m 2 / g or more, and an aggregate size of 45 nm or more, and a second silica having a CTAB specific surface area of 95 m 2 / g or less, and a BET specific surface area of 100 m 2 / g or less. By using such a first silica and a second silica in combination, the first silica having a small average primary particle diameter but a large aggregate size can be dispersed well in the rubber component. Thereby, the dispersibility of the silica can be improved, and excellent rubber breaking strength, wear resistance, low fuel consumption, and processability can be obtained.

[0113] The CTAB specific surface area of the first silica is preferably 190 m 2 / g or more, more preferably 195 m 2 / g or more, further preferably 197 m 2 / g or more. If the CTAB specific surface area is 190 m 2 / g or more, there is a tendency that rubber breaking strength and abrasion resistance are easily improved sufficiently. The CTAB specific surface area of the first silica is preferably 350 m 2 / g or less, more preferably 300 m 2 / g or less, further preferably 250 m 2 / g or less. If the CTAB specific surface area is 350 m 2 / g or less, dispersibility is excellent and aggregation is not easy, so there is a tendency that physical properties are easily maintained.

[0114] The BET specific surface area of the first silica is preferably 190 m 2 / g or more, more preferably 195 m 2 / g or more, further preferably 210 m 2 / g or more. If the BET specific surface area is 190 m 2 / g or more, there is a tendency that rubber breaking strength and abrasion resistance are easily improved sufficiently. The BET specific surface area of the first silica is preferably 350 m 2 / g or less, more preferably 300 m 2 / g or less, further preferably 260 m 2 / g or less. If the BET specific surface area is 350 m 2 / g or less, dispersibility is excellent and aggregation is not easy, so there is a tendency that physical properties are easily maintained. Note that the BET specific surface area of the silica is measured in accordance with ASTM D3037-81.

[0115] The aggregate size of the first silica is 45 nm or more, preferably 50 nm or more, more preferably 55 nm or more, further preferably 60 nm or more. In addition, the aggregate size of the first silica is preferably 100 nm or less, more preferably 80 nm or less, further preferably 70 nm or less, particularly preferably 67 nm or less. By having such an aggregate size, good dispersibility (processability) can be obtained, and excellent low fuel consumption and abrasion resistance can be imparted. Note that the aggregate size of the silica can be measured by the method described in Japanese Patent Application Publication No. 2011-140613.

[0116] The average primary particle diameter of the first silica is preferably 25 nm or less, more preferably 22 nm or less, further preferably 17 nm or less, and particularly preferably 14 nm or less. The lower limit of the average primary particle diameter of the first silica is not particularly limited, and is preferably 3 nm or more, more preferably 5 nm or more, and further preferably 7 nm or more. Although having such a small average primary particle diameter, the dispersibility (processability) of the silica can be further improved by the structure of the carbon black having the above-mentioned aggregate size, and the low fuel consumption and the wear resistance can be further improved. Note that the average primary particle diameter of the silica can be found by observing the silica using a transmission or scanning electron microscope, measuring the primary particle diameters of 400 or more silica observed in a field of view, and averaging the diameters.

[0117] The CTAB specific surface area of the second silica is preferably 10 m 2 / g or more, more preferably 20 m 2 / g or more, and further preferably 30 m 2 / g or more. If the CTAB specific surface area is 10 m 2 / g or more, the reinforcing property becomes high, and it is easy to ensure the mechanical strength and the wear resistance required for the polymer composition used in the manufacture of a tire. The CTAB specific surface area of the second silica is preferably 80 m 2 / g or less, more preferably 60 m 2 / g or less, and further preferably 50 m 2 / g or less. If the CTAB specific surface area is 80 m 2 / g or less, the dispersibility of the silica becomes good, and it is easy to improve the rubber breaking strength and the wear resistance.

[0118] The BET specific surface area of the second silica is preferably 10 m 2 / g or more, more preferably 20 m 2 / g or more, and further preferably 30 m 2 / g or more. If the BET specific surface area is 10 m 2 / g or more, the reinforcing property becomes high, and it is easy to ensure the mechanical strength and the wear resistance required for the polymer composition used in the manufacture of a tire. The BET specific surface area of the second silica is preferably 85 m 2 / g or less, more preferably 60 m 2 / g or less, and further preferably 50 m 2 / g or less. If the BET specific surface area is 85 m 2 / g or less, the dispersibility of the silica becomes good, and it is easy to improve the rubber breaking strength and the wear resistance.

[0119] The average primary particle diameter of the second silica is preferably 20 nm or greater, more preferably 25 nm or greater, further preferably 30 nm or greater, particularly preferably 35 nm or greater, and most preferably 55 nm or greater. In addition, the upper limit of the average primary particle diameter of the second silica is not particularly limited, and is preferably 500 nm or less, more preferably 200 nm or less, further preferably 100 nm or less, and particularly preferably 70 nm or less. By having such an average primary particle diameter, the rubber breaking strength and the wear resistance can be improved.

[0120] (Carbon black)

[0121] As the carbon black, there is no particular limitation, and for example, carbon blacks of the GPF, FEF, HAF, ISAF, and SAF grades can be given. The nitrogen adsorption specific surface area (N2SA) of the above-mentioned carbon black is not particularly limited, and from the viewpoint of more excellent effects and the like according to the present disclosure, it is preferably 50 to 200 m 2 / g, and more preferably 70 to 150 m 2 / g. The nitrogen adsorption specific surface area (N2SA) is a value determined by measuring the amount of nitrogen adsorbed on the surface of the carbon black according to JIS K6217-2:2001 "Part 2: Determination of Specific Surface Area - Nitrogen Adsorption Method - Single Point Method". The carbon black can be used alone as one kind, or two or more kinds can be used in combination. The blending amount of the carbon black is preferably in the range of 1 to 150 parts by mass, and further preferably in the range of 5 to 120 parts by mass, with respect to 100 parts by mass of the rubber component.

[0122] (Inorganic filler)

[0123] As specific examples of the inorganic compound (M), as a compound in which the specific metal is aluminum, for example, aluminum oxide, aluminum oxide monohydrate, aluminum hydroxide, aluminum carbonate, aluminum silicate, calcium aluminate (Al2O3·CaO·2SiO4, etc.); as a compound in which the specific metal is magnesium, for example, magnesium oxide, magnesium hydroxide, magnesium carbonate, magnesium silicate, calcium magnesium silicate (CaMgSiO4), talc, etc.; as a compound in which the specific metal is titanium, for example, titanium oxide, etc.; and as a compound in which the specific metal is calcium, for example, calcium oxide, calcium hydroxide, calcium carbonate, calcium silicate, etc. can be given.

[0124] The total content of the fillers is preferably 10 to 200 parts by mass, more preferably 30 to 150 parts by mass, and further preferably 50 to 120 parts by mass, with respect to 100 parts by mass of the rubber component.

[0125] (Silane coupling agent)

[0126] In the case of compounding silica, a silane coupling agent is preferably compounded. As the silane coupling agent, a publicly known silane coupling agent can be used. For example, bis[3-(triethoxysilyl)propyl]tetrasulfide, bis[3-(triethoxysilyl)propyl]disulfide, 3-[ethoxybis(3,6,9,12,15-pentaoxaoctadecan-1-yloxy)silyl]-1-propanethiol, 3-mercaptopropyltrimethoxysilane, 3-octanoylthio-1-propyltriethoxysilane, and a homopolycondensate thereof or a co-condensate with 3-mercaptopropyltriethoxysilane can be mentioned. Bis[3-(triethoxysilyl)propyl]tetrasulfide can also be used as a commercially available product, for example, Si-69 manufactured by Winkler Co. In addition, bis[3-(triethoxysilyl)propyl]disulfide can also be used as a commercially available product, for example, Si-75 manufactured by Winkler Co. In addition, 3-[ethoxybis(3,6,9,12,15-pentaoxaoctadecan-1-yloxy)silyl]-1-propanethiol can also be used as a commercially available product, for example, Si-363 manufactured by Winkler Co. In addition, 3-mercaptopropyltrimethoxysilane can be used as a commercially available product, for example, KBM803 manufactured by Shin-Etsu Chemical Co. In addition, 3-octanoylthio-1-propyltriethoxysilane can be used as a commercially available product, for example, NXT-Silane manufactured by Momentive. In addition, a condensate of 3-octanoylthio-1-propyltriethoxysilane can also be used as a commercially available product, for example, NXT-Z45 Silane manufactured by Momentive. These silane coupling agents can be used alone or in combination of two or more. The content of the silane coupling agent is preferably 1 part by mass to 30 parts by mass, more preferably 2 parts by mass to 20 parts by mass, with respect to 100 parts by mass of silica.

[0127] (Other additives)

[0128] The polymer composition of the present application can contain other additives such as vulcanizing agents, vulcanization accelerators, vulcanization aid accelerators, anti-aging agents, softening agents, antioxidants, and colorants, etc. within a range not impairing the functions thereof.

[0129] As the vulcanizing agent, powdered sulfur, precipitated sulfur, high-dispersibility sulfur, surface-treated sulfur, insoluble sulfur, dimorpholinodi-sulfide, alkylphenol disulfide, and the like can be mentioned. The content of the vulcanizing agent is preferably 0.1 parts by mass to 10 parts by mass, more preferably 1 part by mass to 5 parts by mass, with respect to 100 parts by mass of the rubber component.

[0130] As the vulcanization accelerator, there are, for example, thiuram-based such as tetramethylthiuram disulfide (TMTD), tetraethylthiuram disulfide (TETD), tetramethylthiuram monosulfide (TMTM), aldehyde-ammonia-based such as hexamethylenetetramine, guanidine-based such as diphenylguanidine (DPG), thiazole-based such as 2-mercaptobenzothiazole (MBT), dibenzothiazyl disulfide (DM), sulfenamide-based such as N-cyclohexyl-2-benzothiazole sulfenamide (CBS), N-tert-butyl-2-benzothiazole sulfenamide (BBS), and dithiocarbamic acid salt-based such as zinc dimethyldithiocarbamate (ZnPDC). The content of the vulcanization accelerator is preferably 0.1 to 10 parts by mass, more preferably 1 to 5 parts by mass, relative to 100 parts by mass of the rubber component.

[0131] As the vulcanization accelerator aid, there are, for example, fatty acids, zinc fatty acids, zinc salts of fatty acids, and zinc oxide. As the fatty acid, there are, for example, acetic acid, propionic acid, butyric acid, stearic acid, acrylic acid, and maleic acid. As the zinc fatty acid, there are, for example, zinc acetate, zinc propionate, zinc butyrate, zinc stearate, zinc acrylate, and zinc maleate. As the zinc salt of the fatty acid, there are, for example, the above-mentioned zinc salts of the fatty acids. The content of the vulcanization accelerator aid is preferably 0.1 to 10 parts by mass, more preferably 1 to 5 parts by mass, relative to 100 parts by mass of the rubber component.

[0132] As the anti-aging agent, there are, for example, compounds of the hindered amine-based and the hindered phenol-based. The content of the anti-aging agent is preferably 0.1 to 10 parts by mass, more preferably 1 to 5 parts by mass, relative to 100 parts by mass of the rubber component.

[0133] As the antioxidant, there are, for example, butylated hydroxytoluene (BHT), butylated hydroxyanisole (BHA), and the like. The content of the antioxidant is preferably 0.1 to 10 parts by mass, more preferably 1 to 5 parts by mass, relative to 100 parts by mass of the rubber component.

[0134] As the softening agent, there are, for example, the petroleum-based softening agents such as aromatic oil, paraffin oil, and naphthenic oil, the plant-based softening agents such as palm oil, castor oil, cottonseed oil, and soybean oil, and the like. One or two or more kinds thereof can be appropriately selected and used. In the case where the softening agent is contained, from the viewpoint of the ease of handling, it is preferable that the softening agent be a liquid at ordinary temperature such as 25°C, and, for example, the petroleum-based softening agent such as aromatic oil, paraffin oil, and naphthenic oil, and particularly, aromatic oil is preferable. The content of the softening agent is preferably 10 to 200 parts by mass, more preferably 20 to 100 parts by mass, relative to 100 parts by mass of the rubber component.

[0135] As the colorant, inorganic pigments such as titanium dioxide, zinc oxide, ultramarine blue, red iron oxide, lithopone, lead, cadmium, iron, cobalt, aluminum, hydrochloride, sulfate, azo pigments, copper phthalocyanine pigments, and the like can be mentioned. The content of the colorant is preferably 0.1 to 10 parts by mass, more preferably 1 to 5 parts by mass, relative to 100 parts by mass of the rubber component.

[0136] The other additives can be mixed with the rubber component by using a publicly known rubber mixing machine such as a roll, a Banbury mixer, a kneader, and the like, and vulcanized under arbitrary conditions to be used as a polymer composition. The amount of the other additives to be added can be the conventional amount unless the object of the present application is impaired.

[0137] [Method for producing polymer composition]

[0138] The method for producing the polymer composition of the present application at least includes a step of mixing the above rubber component with the above raw material component polymer. The method for producing the polymer composition can preferably include a step of further mixing the above vulcanizing agent. More preferably, it can include a step of further mixing the vulcanizing agent and the above vulcanization accelerator.

[0139] In addition, the method for producing the polymer composition can be mixed with the above other additives as appropriate within a range not impairing the function of the polymer composition.

[0140] A publicly known mixing device can be used in the production of the polymer composition, and the mixing temperature, time, order of mixing, and the like can be appropriately selected.

[0141] [Rubber product]

[0142] The polymer composition of the present application can be used to produce a rubber product by a publicly known method and technical common sense known to those skilled in the art. As the rubber product, tires, rubber members for automobiles other than tires (exterior members, interior members, weather strips, trunk room members, pedal members, sealing strip members, sealant members, gasket members), hoses, belts, seats, shock absorbing rubbers, rolls, linings, adhesive tapes, sealing materials, gloves, fender materials, medical rubbers (syringe gaskets, tubes, catheters), gaskets (for household electrical appliances, for construction), asphalt modifiers, handle members, toys, shoes, sandals, keyboards, gears, PET bottle cap gaskets, and the like can be mentioned. Among these, tires are preferred.

[0143] [Tire]

[0144] For example, a tire can be manufactured by extruding the polymer composition, then molding using a tire molding machine, and then heating and pressurizing using a vulcanizer to form crosslinks. The shape, structure, size, and material of the tire are not particularly limited and can be appropriately selected according to the purpose. In addition, the use of the tire is not particularly limited, and for example, a passenger car tire, a heavy load tire, a machine foot pedal (motorcycle) tire, and a studless tire can be given. The tire manufactured using the polymer composition of the present application has high grip and high wear resistance.

[0145] The polymer composition of the present application can be applied to each part of a tire. The application part of the tire is not particularly limited and can be appropriately selected from a tread, a sidewall, a carcass, an inner liner, a tire base, and a belt portion according to the purpose. Among these, the tire tread and the sidewall are particularly preferred.

[0146] Examples

[0147] Hereinafter, the present application will be specifically described by citing examples and comparative examples, but the present application is not limited to these examples. It should be noted that "parts" and "%" in the examples and comparative examples are based on mass unless otherwise specified. The following shows the measurement method of various physical properties of the polymer and the rubber.

[0148] (1) Bonded styrene content (%: content of structural unit derived from aromatic vinyl compound): calculated by 500 MHz H-NMR measurement using deuterated chloroform as a solvent. 1 H-NMR measurement.

[0149] (2) Proportion of short chain of aromatic vinyl compound and (3) Proportion of long chain of aromatic vinyl compound: After the styrene butadiene copolymer rubber is decomposed by ozone according to the method of Tanaka et al. (Polymer, 22, 1721 (1981)), the proportion of short chain of aromatic vinyl compound and the proportion of long chain of aromatic vinyl compound are measured by a gel permeation chromatography (GPC) device "Alliance HPLC" (manufactured by Waters Corporation) under the following conditions, and the number of styrene chains corresponding to the peaks is calculated based on the retention time of the peak apex (when multiple peaks exist, with respect to each peak) of the obtained GPC curve. In addition, the proportion of short chain of aromatic vinyl compound and the proportion of long chain of aromatic vinyl compound are calculated based on the area ratio of each peak.

[0150] (GPC conditions)

[0151] • Column: 2 of trade name "GPC KF-801" (manufactured by Tosoh Corporation)

[0152] • Column temperature: 40°C

[0153] • Mobile phase: Tetrahydrofuran

[0154] • Flow rate: 0.6 ml / min

[0155] • Sample concentration: 0.2 wt%

[0156] (4) Vinyl content (%): calculated from the results of1H-NMR measurement at 500 MHz. 1

[0157] (5) Weight average molecular weight of the polymer: measured using a gel permeation chromatography (GPC) device "HLC-8120 GPC" (manufactured by Tosoh Corporation) under the following conditions, and the weight average molecular weight (Mw) converted to polystyrene was calculated from the retention time corresponding to the apex of the largest peak in the obtained GPC curve.

[0158] (GPC conditions)

[0159] • Column: two of "GMHXL" (manufactured by Tosoh Corporation)

[0160] • Column temperature: 40°C

[0161] • Mobile phase: tetrahydrofuran

[0162] • Flow rate: 1.0 ml / min

[0163] • Sample concentration: 10 mg / 20 ml

[0164] <Manufacturing Example of Conjugated Diene-Based Polymer (A-1)>

[0165] (Styrene-butadiene rubber (SSBR) 1)

[0166] A nitrogen-substituted 5-liter high-pressure autoclave reactor was charged with cyclohexane 2000 g, tetrahydrofuran 2.5 mL as a vinyl content adjusting agent, potassium 4-dodecylbenzenesulfonate 0.08 mmol as a potassium compound, and styrene 175 g and 1,3-butadiene 150 g as polymerization monomers. After adjusting the temperature of the contents of the reactor to 35°C, polymerization was initiated by adding n-butyllithium 3.7 mmol as a polymerization initiator. At the time when the polymerization conversion reached 20% (corresponding to the time when the temperature of the contents reached 45°C), 1,3-butadiene (additional component) 175 g was added to the reactor at a constant supply rate over 25 minutes. The polymerization was performed under adiabatic conditions, and the maximum temperature reached 85°C.

[0167] ​At the time when the polymerization conversion rate reached 99% (35 minutes after the initiation of polymerization), 3.7 mmol of 3-(N,N-bistrimethylsilyl)aminopropylmethyldiethoxysilane as a terminal modifier was added, and stirred for 10 minutes. After 4.40 g of 2,6-di-t-butyl-p-cresol as an anti-aging agent was added to the stirred polymer solution, the solvent was removed by stripping, and dried using a hot roll adjusted to 130°C, thereby obtaining a modified conjugated diene polymer (hereinafter, also simply referred to as "styrene butadiene rubber (SSBR) 1").

[0168] (styrene butadiene rubber (SSBR) 2)

[0169] A 50-liter high-pressure autoclave reactor (1st reactor) was continuously charged with 1,3-butadiene as a monomer at a rate of 83 g / min, with styrene as a monomer at a rate of 28 g / min, with cyclohexane as a solvent at a rate of 745 g / min, with tetrahydrofuran as a vinyl content regulator (randomizer) at a rate of 1.2 g / min, and with n-butyllithium as a polymerization initiator at a rate of 55 mg / min, while the temperature in the reactor was controlled at 75°C.

[0170] The polymer solution was continuously discharged from the 1st reactor at a rate of 860 g / min, and a compound represented by the following formula (N-Si-1) was added to the discharged polymer solution at a rate of 115 mg / min, and continuously introduced into the 2nd reactor to be reacted. Di-t-butyl-p-cresol was added at the outlet of the 2nd reactor at 0.88 parts by mass relative to 100 parts by mass of the polymer. The polymer solution thus produced was subjected to solvent removal by stripping, and dried using a hot roll adjusted to 130°C, thereby obtaining a modified conjugated diene polymer (hereinafter, also simply referred to as "styrene butadiene rubber (SSBR) 2").

[0171]

[0172] (styrene butadiene rubber (SSBR) 3)

[0173] 2000 g of cyclohexane, 5.6 mL of tetrahydrofuran (as a vinyl content regulator), and 175 g of styrene and 150 g of 1,3-butadiene (as monomers) were charged into a nitrogen-replaced 5 L autoclave. After adjusting the temperature of the reactor contents to 45 °C, 3.7 mmol of n-butyllithium (as a polymerization initiator) was added to initiate polymerization. When the polymerization conversion reached 20% (equivalent to when the contents temperature reached 60 °C), 175 g of 1,3-butadiene (an additional component) was added to the reactor over a controlled feed rate over 25 minutes. Polymerization was carried out under adiabatic conditions, with a maximum temperature reaching 85 °C.

[0174] At the point when the polymerization conversion reached 99% (35 minutes after polymerization initiation), 3.7 mmol of 3-(N,N-bistrimethylsilyl)aminopropylmethyldiethoxysilane was added as an end modifier, and the mixture was stirred for 10 minutes. 4.40 g of 2,6-di-tert-butyl-p-cresol was added as an anti-aging agent to the stirred polymer solution, followed by solvent removal via stripping and drying using a hot roller heated to 130°C to obtain the modified conjugated diene polymer (hereinafter also referred to as "styrene-butadiene rubber (SSBR) 3").

[0175] (Styrene-butadiene rubber (SSBR) 4)

[0176] A 5-liter autoclave reactor, after nitrogen replacement, was charged with 2000 g of cyclohexane, 0.23 mmol of 2,2-bis(2-tetrahydrofuranyl)propane as a vinyl content regulator, 0.15 mmol of potassium 4-dodecylbenzenesulfonate as a potassium compound, and 125 g of styrene and 200 g of 1,3-butadiene as polymerization monomers. After adjusting the temperature of the reactor contents to 40°C, 3.7 mmol of n-butyllithium as a polymerization initiator was added to initiate polymerization. At the point when the polymerization conversion reached 20% (equivalent to when the contents temperature reached 50°C), 175 g of 1,3-butadiene (an additional component) was added to the reactor over 25 minutes at a controlled feed rate. Polymerization was carried out under adiabatic conditions, with a maximum temperature of 85°C. At the point when the polymerization conversion reached 99% (35 minutes after polymerization initiation), 3.7 mmol of 3-(N,N-bistrimethylsilyl)aminopropylmethyldiethoxysilane as an end modifier was added, and the mixture was stirred for 10 minutes. 4.40 g of 2,6-di-tert-butyl-p-cresol as an anti-aging agent was added to the stirred polymer solution, followed by solvent removal via stripping and drying using a hot roller heated to 130°C, thereby obtaining the modified conjugated diene polymer (hereinafter also referred to as "styrene-butadiene rubber (SSBR) 4").

[0177] (Styrene-butadiene rubber (SSBR) 5)

[0178] A 5-liter nitrogen-substituted autoclave reactor was charged with cyclohexane 2000 g, tetrahydrofuran 1.5 mL as a vinyl group content adjusting agent, and styrene 100 g and 1,3-butadiene 180 g as polymerization monomers. After adjusting the temperature of the contents of the reactor to 75°C, polymerization was initiated by adding n-butyllithium 3.0 mmol as a polymerization initiator. At the time when the polymerization conversion reached 20% (corresponding to the time when 5 minutes had elapsed after the initiation of polymerization), 1,3-butadiene (additional component) 120 g was added to the reactor at a certain supply rate over 30 minutes. The polymerization was carried out under isothermal conditions, with the maximum temperature reaching 85°C.

[0179] At the time when the polymerization conversion reached 99% (35 minutes after the initiation of polymerization), 3-(N,N-bistrimethylsilyl)aminopropylmethyldiethoxysilane 3.0 mmol as a terminal modifier was added, and stirred for 10 minutes. After adding 2,6-di-tert-butyl-p-cresol 3.52 g as an anti-aging agent to the polymer solution after stirring, desolventization was performed by stripping, and drying was performed using a hot roll adjusted to 130°C, thereby obtaining a modified conjugated diene polymer (hereinafter, also simply referred to as "styrene butadiene rubber (SSBR) 5").

[0180] The details of the above-obtained SSBRs 1 to 5 are shown in Table 1 below.

[0181] [Table 1]

[0182]

[0183] <Preparation of raw material polymer>

[0184] Resins 1 to 7 below were prepared.

[0185] • Resin 1 (manufactured by ENEOS Co., trade name: T-REZ RB100, unhydrogenated aromatic hydrocarbon resin, raw material: C5 fraction containing aliphatic olefin)

[0186] • Resin 2 (manufactured by ENEOS Co., trade name: T-REZ RB093, unhydrogenated aromatic hydrocarbon resin, raw material: C5 fraction containing aliphatic olefin)

[0187] • Resin 3 (manufactured by ENEOS Co., trade name: T-REZ RC115, unhydrogenated aromatic hydrocarbon resin, raw material: C5 fraction containing aliphatic olefin)

[0188] • Resin 4 (manufactured by ENEOS Co., trade name: T-REZ RC100, unhydrogenated aromatic hydrocarbon resin, raw material: C5 fraction containing aliphatic olefin)

[0189] • Resin 5 (manufactured by ENEOS Corporation, trade name: T-REZ RC093, unhydrogenated aromatic hydrocarbon resin, raw material: C5 fraction containing aliphatic olefin)

[0190] • Resin 6 (manufactured by ENEOS Corporation, trade name: T-REZ RD104, unhydrogenated aromatic hydrocarbon resin, raw material: C5 fraction containing aliphatic olefin and C9 fraction containing aromatic olefin)

[0191] • Resin 7 (manufactured by ENEOS Corporation, trade name: T-REZ PR802, unhydrogenated aromatic hydrocarbon resin, raw material: C5 fraction containing aliphatic olefin and C9 fraction containing aromatic olefin)

[0192] Evaluation of Resins

[0193] Measurement of Number Average Molecular Weight (Mn)

[0194] Each of the above resins was dissolved in tetrahydrofuran to prepare a sample at a concentration of 10 g / L, and HLC-8320 GPC (using column: TSKgel SuperHZ column series) manufactured by Tosoh Corporation was used to measure the number average molecular weight Mn. The number average molecular weight Mn was calculated from a calibration curve prepared in advance using a polystyrene kit (EasiVial PS-M and PS-L) manufactured by Agilent Corporation, based on the obtained RI curve. The calculation results are shown in Table 2.

[0195] Measurement of Proton Mass

[0196] The proton mass of each of the above resins was measured according to the following measurement steps 1 to 3. The measurement results are shown in Table 2.

[0197] 1. The sample in which 10 mg of the resin and 5.5 mg of a standard substance (dimethyl terephthalate) were dissolved in 1 g of deuterated chloroform was measured by H NMR. 1 It should be noted that the standard substance was selected so that the peaks thereof did not overlap with the aromatic region of the resin.

[0198] 2. The number of aromatic protons in the sample was quantified using an internal standard method. Based on the amount of the sample, 2.5 x 10 －5 mol or more of dimethyl terephthalate was contained in the sample, and when the integral value of the aromatic ring protons (4H) of the internal standard was set to 1.00, the corresponding proton mass was calculated from the integral values of the olefin region (4.5-6.0 ppm) and the aromatic region (6.0-7.5 ppm) of the resin. In addition, the protons from the deuterated chloroform residual component overlapping with the aromatic region could be ignored by subtracting the value obtained by a blank measurement using a sample not containing the resin in advance.

[0199] 3. The number of aromatic protons contained in one molecule was calculated from the Mn of each resin calculated above.

[0200] [Table 2]

[0201]

[0202] <Experiment Example 1>

[0203] [Example 1]

[0204] Each of the following components was kneaded using a 250 mL kneader (Laboplast Mill B250, manufactured by Toyo Rikiki Co., Ltd.) to obtain a polymer composition. The kneading conditions were temperature adjustment of 70°C, rotation speed of 50 rpm, and kneading time: plasticizing of the rubber component for 0.5 minutes → kneading for 1.5 minutes after addition of the silica and the additives → kneading for 2 minutes (the rubber temperature during kneading was maintained at 150°C).

[0205] • SSBR1 60 parts by mass

[0206] • SSBR2 40 parts by mass

[0207] • Silica (manufactured by Solvay, trade name: Hi-Sil® 1165MP) 70 parts by mass

[0208] • Carbon black (manufactured by DKS Co., Ltd., trade name: Seast KH) 5.60 parts by mass

[0209] • Zinc oxide No. 3 (manufactured by Toho Zinc Co., Ltd., trade name: Ginrei R) 3 parts by mass

[0210] • Stearic acid (manufactured by Nikko Chemicals Co., Ltd., trade name: Stearic acid 300) 2 parts by mass

[0211] • Anti-aging agent (manufactured by Onohoshi Shinko Chemical Industry Co., Ltd., trade name: NOCRAC 6C) 1 part by mass

[0212] • Silane coupling agent (manufactured by Evonik, trade name: Si75) 5.60 parts by mass

[0213] • Resin 1 15.0 parts by mass

[0214] • Sulfur (manufactured by Hosoi Chemical Industry Co., Ltd., trade name: Oil sulfur 325 mesh (5%)) 1.20 parts by mass

[0215] • Vulcanization accelerator 1 (manufactured by Onohoshi Shinko Chemical Industry Co., Ltd., trade name: NOCCELER CZ) 1.44 parts by mass

[0216] • Vulcanization accelerator 2 (manufactured by Onohoshi Shinko Chemical Industry Co., Ltd., trade name: NOCCELER D) 1.20 parts by mass

[0217] [Example 2]

[0218] 15.0 parts by mass of resin 2 was added instead of resin 1, and otherwise the same as in Example 1 to obtain a polymer composition.

[0219] [Example 3]

[0220] 15.0 parts by mass of resin 3 was added instead of resin 1, and otherwise the same as in Example 1 to obtain a polymer composition.

[0221] [Example 4]

[0222] 15.0 parts by mass of resin 4 was added instead of resin 1, and otherwise the same as in Example 1 to obtain a polymer composition.

[0223] [Example 5]

[0224] 15.0 parts by mass of resin 5 was added instead of resin 1, and otherwise the same as in Example 1 to obtain a polymer composition.

[0225] [Example 6]

[0226] 15.0 parts by mass of resin 6 was added instead of resin 1, and otherwise the same as in Example 1 to obtain a polymer composition.

[0227] [Comparative Example 1]

[0228] 15.0 parts by mass of aromatic oil (T-DAE, manufactured by ENEOS Corporation) was added instead of resin 1, and otherwise the same as in Example 1 to obtain a polymer composition.

[0229] [Comparative Example 2]

[0230] 15.0 parts by mass of resin 8 (homo-oligomer of α-methylstyrene, manufactured by Cray Valley Corporation, trade name: W-140, number average molecular weight (Mn) 1701) was added instead of resin 1, and otherwise the same as in Example 1 to obtain a polymer composition.

[0231] [Physical Property Evaluation]

[0232] (Viscoelasticity)

[0233] Using each of the polymer compositions obtained above, a rubber sheet (2 mm thick, 150 mm long, 150 mm wide) was obtained by heating and pressurizing at 160°C and 20 MPa for 30 minutes using a mold (manufactured by DUMBBELL, model number: MP-124NJ).

[0234] Next, for the obtained rubber sheet, tan δ at 0°C was found under the conditions of a strain of 20 μm (about 0.1%), a frequency of 10 Hz, and a measurement temperature of 0°C, using a viscoelasticity measuring device (Rheogel E-4000 manufactured by UBM Co., Ltd.) in accordance with JIS K6394. The measurement results are shown in Table 3. The greater the value of tan δ (0°C), the more excellent the gripping property. Note that, for each of the results of tan δ, Examples 1 to 6 and Comparative Example 1 are described as relative values when the value of Comparative Example 2 is taken as 100.

[0235] (Wear resistance)

[0236] The rubber sheet was obtained by the same operation as in the test of viscoelasticity described above. The obtained rubber sheet was used to produce a test piece of the following dimensions. Next, the test piece was subjected to a wear test in accordance with JIS K6264-7 using a Lambourn wear tester (manufactured by Kamisawa Mfg. Co., Ltd.) under the following conditions.

[0237] • Slip rate: 25%

[0238] • Additional load: 4.5 kg

[0239] • Test temperature: 50°C

[0240] • Sand drop amount: 10 g / min

[0241] • Dimensions: Test piece = diameter 49 mm, thickness 5 mm

[0242] Grinding stone = diameter 175 mm, thickness 25 mm

[0243] The wear amount was determined from the mass of the test piece before and after the wear test. The specific wear volume was calculated from the wear amount and the calculated specific gravity, and is described in Table 3 as an index (relative value) when the value of Comparative Example 2 is taken as 100. Note that the index of each example is the value calculated as follows.

[0244] Index of each example = wear amount of Comparative Example 2 (reference) / wear amount of each example x 100

[0245] That is, the greater the value of the index of each example, the more excellent the wear resistance.

[0246] [Table 3]

[0247]

[0248] <Experimental Example 2>

[0249] [Example 7]

[0250] Resin 7 was added at 15.0 parts by mass instead of Resin 1, and otherwise the same as in Example 1 to obtain a polymer composition.

[0251] [Example 8]

[0252] 40 parts by mass of SSBR2 and 53 parts by mass of SSBR3 were added as styrene butadiene rubbers, and otherwise, the same as Example 7 to obtain a polymer composition.

[0253] [Comparative Example 3]

[0254] 40 parts by mass of SSBR2 and 60 parts by mass of SSBR3 were added as styrene butadiene rubbers, and otherwise, the same as Example 7 to obtain a polymer composition.

[0255] [Physical Property Evaluation]

[0256] (Viscoelasticity)

[0257] The same as Test Example 1 using each polymer composition to obtain a rubber sheet. Next, tan δ at a measurement temperature of 0°C was calculated for the obtained rubber sheet. The measurement results are shown in Table 4. Note that, for each result of tan δ, Examples 7 and 8 are described as relative values when the value of Comparative Example 3 is set to 100.

[0258] (Wear Resistance)

[0259] The same as the above test of viscoelasticity to obtain a rubber sheet. Next, using the obtained rubber sheet, the same as Test Example 1 to measure the amount of wear. The specific wear volume was calculated from the amount of wear and the calculated specific gravity, and described in Table 4 as an index (relative value) when the value of Comparative Example 3 is set to 100.

[0260] [Table 4]

[0261]

[0262] <Test Example 3>

[0263] [Example 9]

[0264] 40 parts by mass of SSBR2 and 60 parts by mass of SSBR4 were added as styrene butadiene rubbers, and otherwise, the same as Example 7 to obtain a polymer composition.

[0265] [Comparative Example 4]

[0266] 40 parts by mass of SSBR2 and 60 parts by mass of SSBR5 were added as styrene butadiene rubbers, and otherwise, the same as Example 9 to obtain a polymer composition.

[0267] [Physical Property Evaluation]

[0268] (Viscoelasticity)

[0269] Rubber sheets were obtained using each of the polymer compositions similarly to Test Example 1. Next, tan δ at a measurement temperature of 0°C was calculated for the obtained rubber sheets. The measurement results are shown in Table 5. Note that, for each of the tan δ results, Example 9 is described as a relative value when the value of Comparative Example 4 is taken as 100.

[0270] (Wear resistance)

[0271] Rubber sheets were obtained similarly to the above-described viscoelasticity test. Next, using the obtained rubber sheets, the amount of wear was measured similarly to Test Example 1. From the amount of wear and the calculated specific gravity, the specific wear volume was calculated, and is described in Table 5 as an index (relative value) when the value of Comparative Example 4 is taken as 100.

[0272] [Table 5]

[0273]

[0274] <TEST EXAMPLE 4>

[0275] [Example 10]

[0276] The amount of silica added was changed to 100 parts by mass, the amount of silane coupling agent added was changed to 8.0 parts by mass, and the amount of resin 7 added was changed to 40.0 parts by mass, and otherwise, a polymer composition was obtained similarly to Example 7.

[0277] [Comparative Example 5]

[0278] Resin 8 was added at 40.0 parts by mass instead of resin 7, and otherwise, a polymer composition was obtained similarly to Example 10.

[0279] [Physical property evaluation]

[0280] (Viscoelasticity)

[0281] Rubber sheets were obtained using each of the polymer compositions similarly to Test Example 1. Next, tan δ at a measurement temperature of 0°C was calculated for the obtained rubber sheets. The measurement results are shown in Table 6. Note that, for each of the tan δ results, Example 10 is described as a relative value when the value of Comparative Example 5 is taken as 100.

[0282] (Wear resistance)

[0283] Rubber sheets were obtained similarly to the above-described viscoelasticity test. Next, using the obtained rubber sheets, the amount of wear was measured similarly to Test Example 1. From the amount of wear and the calculated specific gravity, the specific wear volume was calculated, and is described in Table 6 as an index (relative value) when the value of Comparative Example 5 is taken as 100.

[0284] [Table 6]

[0285]

Claims

1. A polymer composition comprising: a rubber component comprising a conjugated diene polymer (A-1), and at least one selected from the group consisting of a raw material component polymer comprising a C5 fraction containing an aliphatic olefin, and a raw material component polymer comprising a C9 fraction containing an aromatic olefin and a C5 fraction containing an aliphatic olefin; the conjugated diene polymer (A-1) comprises structural units derived from a conjugated diene compound and structural units derived from an aromatic vinyl compound, the content of the structural units derived from the aromatic vinyl compound is 5 to 60 mass% relative to the total amount of the structural units derived from the conjugated diene compound and the structural units derived from the aromatic vinyl compound, relative to the content of the structural units derived from the aromatic vinyl compound, aromatic vinyl compound short chains of less than 40 mass% of aromatic vinyl compound units are not continuous, and aromatic vinyl compound long chains of 10 mass% or less of 8 or more aromatic vinyl compound units are continuous.

2. The polymer composition according to claim 1, wherein, the C5 fraction containing an aliphatic olefin comprises at least one selected from the group consisting of piperylene, isoprene, 1-pentene, 2-pentene, 2-methyl-1-butene, 2-methyl-2-butene, 3-methyl-1-butene, 1,2-pentadiene, and 3-methyl-1,2-butadiene.

3. The polymer composition of claim 1, wherein, the C9 fraction containing an aromatic olefin comprises at least one selected from the group consisting of vinyltoluene, α-methylstyrene, styrene, indene, and methylindene.

4. The polymer composition of claim 1, wherein, the raw material component polymer satisfies the following conditions per 1 molecule of the proton: 0 < aromatic proton amount ≤ 95, 0 < olefin proton amount ≤ 90.

5. The polymer composition of claim 1, wherein, the number average molecular weight Mn of the raw material component polymer is 300 g / mol or more and less than 3000 g / mol.

6. The polymer composition of claim 1, wherein, the content of the conjugated diene polymer (A-1) is 5 mass% or more of the total amount of the rubber component.

7. The polymer composition of claim 1, wherein, the conjugated diene polymer (A-1) has a nitrogen-containing group and a hydrocarbon oxy silyl group.

8. The polymer composition of claim 1, wherein, further comprising a filler.

9. A rubber product formed using the polymer composition according to any one of claims 1 to 8.

10. The rubber article of claim 9, wherein, the rubber product is selected from the group consisting of a tire, a tire tread, and a tire sidewall.

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