JP2019183010A - Rubber composition for tire, and pneumatic tire - Google Patents

Abstract

To provide a rubber composition for a tire, capable of comprehensively improving fuel economy, wear resistance, dry grip performance and wet grip performance, and a pneumatic tire produced using the rubber composition.SOLUTION: The present invention relates to the rubber composition for a tire, which contains a rubber component containing 40-80 mass% of a styrene-butadiene rubber and 10-35 mass% of a butadiene rubber, 80 pts.mass or more of silica based on 100 pts.mass of the rubber component, and 10-60 pts.mass of a terpene-based resin based on 100 pts.mass of the rubber component and which satisfies formula (A) α/β≤3, where α is the styrene content [mass%] of the styrene-butadiene rubber; and β is the content [pts.mass] of the terpene-based resin based on 100 pts.mass of the rubber component.SELECTED DRAWING: None

Description

The present invention relates to a tire rubber composition and a pneumatic tire.

In recent years, due to increasing interest in environmental issues, there has been a strong demand for lower fuel consumption for automobiles, and rubber compositions used for automobile tires are also required to have excellent fuel efficiency. .

Tires are required to have grip performance such as dry grip performance and wet grip performance in order to ensure safety and the like. In order to meet this requirement, styrene butadiene rubber is widely used as a rubber component. However, when styrene butadiene rubber is used, fuel economy and wear resistance tend to be reduced. Thus, grip performance, fuel efficiency, and wear resistance are contradictory, and it is difficult to improve them comprehensively.

The present invention solves the above-mentioned problems and can improve the fuel efficiency, wear resistance, dry grip performance and wet grip performance in a comprehensive manner, and a pneumatic tire manufactured using the rubber composition The purpose is to provide.

The present invention relates to a rubber component having a styrene butadiene rubber content of 40 to 80% by mass and a butadiene rubber content of 10 to 35% by mass, and a silica having a content of 80 parts by mass or more based on 100 parts by mass of the rubber component. And a terpene resin having a content of 10 to 60 parts by mass with respect to 100 parts by mass of the rubber component, and relates to a tire rubber composition satisfying the following formula (A).
(A) α / β ≦ 3
α: Styrene content of styrene-butadiene rubber [% by mass]
β: Content of terpene resin relative to 100 parts by mass of rubber component [parts by mass]

The rubber composition preferably contains carbon black having a specific surface area of cetyltrimethylammonium bromide of 130 m ² / g or more.

It is preferable that the styrene-butadiene rubber has a styrene content of 35% by mass or more.

The rubber composition preferably satisfies the following formula (B).
(B) γ1 / γ2 ≦ 0.1
γ1: content of carbon black with respect to 100 parts by mass of rubber component [parts by mass]
γ2: Silica content with respect to 100 parts by mass of rubber component [parts by mass]

The nitrogen adsorption specific surface area of the silica is preferably 220 m ² / g or more.

It is preferable that content of the said silica with respect to 100 mass parts of said rubber components is 100-130 mass parts.

The rubber composition preferably contains a mercapto silane coupling agent.

In 100% by mass of the rubber component, the content of low cis butadiene rubber having a cis content of 50% by mass or less is preferably 10% by mass or more.

It is preferable that the content of the plasticizer with respect to 100 parts by mass of the rubber component is 40 parts by mass or more.

The present invention also relates to a pneumatic tire produced using the rubber composition.

According to the present invention, since the tire rubber composition contains a predetermined amount of styrene butadiene rubber, butadiene rubber, silica, and terpene resin and satisfies the formula (A), low fuel consumption, wear resistance, dry grip Performance and wet grip performance can be improved comprehensively.

The tire rubber composition of the present invention contains a predetermined amount of styrene butadiene rubber (SBR), butadiene rubber (BR), silica and terpene resin, and satisfies the formula (A).

The rubber composition has the above-described effects, which are presumed to be achieved by the following effects.
When SBR is used as the main component of the rubber component, the grip performance tends to be improved, but the fuel economy and wear resistance tend to be reduced. On the other hand, in the above rubber composition, BR is used as a rubber component other than SBR, the ratio thereof is adjusted, the amount of silica and the amount of terpene resin are adjusted to a specific range, and further, SBR styrene. By adjusting the amount and the amount of the terpene resin to a specific ratio, the silica and the terpene resin are favorably dispersed in the rubber composition. Thereby, it is considered that fuel efficiency, wear resistance, dry grip performance, and wet grip performance are comprehensively improved.

The rubber composition contains SBR as a rubber component.
It does not specifically limit as SBR, For example, emulsion polymerization styrene butadiene rubber (E-SBR), solution polymerization styrene butadiene rubber (S-SBR), etc. can be used. SBR may be either non-modified SBR or modified SBR.

The modified SBR may be any SBR having a functional group that interacts with a filler such as silica. For example, at least one terminal of SBR is modified with a compound having a functional group (modifier). SBR (terminal-modified SBR having the above-mentioned functional group at the terminal), main-chain-modified SBR having the above-mentioned functional group at the main chain, and main-chain end-modified SBR having the above-mentioned functional group at the main chain and the terminal (for example, in the main chain) A hydroxyl group modified (coupled) with a polyfunctional compound having the above functional group and having at least one terminal modified with the above modifier with a main chain terminal modified SBR) or a polyfunctional compound having two or more epoxy groups in the molecule. And terminal-modified SBR into which an epoxy group has been introduced.

Examples of the functional groups include amino groups, amide groups, silyl groups, alkoxysilyl groups, isocyanate groups, imino groups, imidazole groups, urea groups, ether groups, carbonyl groups, oxycarbonyl groups, mercapto groups, sulfide groups, disulfides. Group, sulfonyl group, sulfinyl group, thiocarbonyl group, ammonium group, imide group, hydrazo group, azo group, diazo group, carboxyl group, nitrile group, pyridyl group, alkoxy group, hydroxyl group, oxy group, epoxy group, etc. . These functional groups may have a substituent. Among them, an amino group (preferably an amino group in which a hydrogen atom of the amino group is substituted with an alkyl group having 1 to 6 carbon atoms), an alkoxy group (preferably an alkoxy group having 1 to 6 carbon atoms), an alkoxysilyl group ( An alkoxysilyl group having 1 to 6 carbon atoms is preferred.

（式中、Ｒ^１、Ｒ^２及びＲ^３は、同一又は異なって、アルキル基、アルコキシ基、シリルオキシ基、アセタール基、カルボキシル基（−ＣＯＯＨ）、メルカプト基（−ＳＨ）又はこれらの誘導体を表す。Ｒ^４及びＲ^５は、同一又は異なって、水素原子又はアルキル基を表す。Ｒ^４及びＲ^５は結合して窒素原子と共に環構造を形成してもよい。ｎは整数を表す。） As the modified SBR, SBR modified with a compound (modifier) represented by the following formula is particularly preferable.

Wherein R ¹ , R ² and R ³ are the same or different and represent an alkyl group, an alkoxy group, a silyloxy group, an acetal group, a carboxyl group (—COOH), a mercapto group (—SH) or a derivative thereof. R ⁴ and R ⁵ may be the same or different and each represents a hydrogen atom or an alkyl group, R ⁴ and R ⁵ may be bonded to form a ring structure with a nitrogen atom, and n represents an integer.)

As the modified SBR modified with the compound represented by the above formula (modifier), the polymerization terminal (active terminal) of the styrene butadiene rubber (S-SBR) of solution polymerization is the compound represented by the above formula. Modified SBR (modified SBR described in JP 2010-111753 A) is preferably used.

R ¹ , R ² and R ³ are preferably alkoxy groups (preferably having 1 to 8 carbon atoms, more preferably having 1 to 4 carbon atoms). R ⁴ and R ⁵ are preferably an alkyl group (preferably an alkyl group having 1 to 3 carbon atoms). n is preferably 1 to 5, more preferably 2 to 4, and still more preferably 3. In the case of forming a ring structure with a nitrogen atom bonded to R ⁴ and R ^5, it is preferably a 4- to 8-membered ring. The alkoxy group also includes a cycloalkoxy group (such as cyclohexyloxy group) and an aryloxy group (such as phenoxy group and benzyloxy group).

Specific examples of the modifier include 2-dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 2-dimethylaminoethyltriethoxysilane, 3-dimethylaminopropyltriethoxysilane, 2-diethylaminoethyltri Examples include methoxysilane, 3-diethylaminopropyltrimethoxysilane, 2-diethylaminoethyltriethoxysilane, and 3-diethylaminopropyltriethoxysilane. Of these, 3-dimethylaminopropyltrimethoxysilane, 3-dimethylaminopropyltriethoxysilane, and 3-diethylaminopropyltrimethoxysilane are preferable. These may be used alone or in combination of two or more.

As the modified SBR, modified SBR modified with the following compound (modifier) can also be suitably used. Examples of the modifier include polyglycidyl ethers of polyhydric alcohols such as ethylene glycol diglycidyl ether, glycerin triglycidyl ether, trimethylol ethane triglycidyl ether, trimethylol propane triglycidyl ether; and two or more such as diglycidylated bisphenol A Polyglycidyl ethers of aromatic compounds having the following phenol groups; polyepoxy compounds such as 1,4-diglycidylbenzene, 1,3,5-triglycidylbenzene, polyepoxidized liquid polybutadiene; 4,4′-diglycidyl-diphenyl Epoxy group-containing tertiary amines such as methylamine and 4,4′-diglycidyl-dibenzylmethylamine; diglycidylaniline, N, N′-diglycidyl-4-glycidyloxyaniline, diglycidyl Luso toluidine, tetraglycidyl meta-xylene diamine, tetraglycidyl diaminodiphenylmethane, tetraglycidyl -p- phenylenediamine, diglycidyl aminomethyl cyclohexane, diglycidyl amino compounds such as tetraglycidyl-1,3-bisaminomethylcyclohexane;

Amino group-containing acid chlorides such as bis- (1-methylpropyl) carbamic acid chloride, 4-morpholine carbonyl chloride, 1-pyrrolidine carbonyl chloride, N, N-dimethylcarbamic acid chloride, N, N-diethylcarbamic acid chloride; 1 , 3-bis- (glycidyloxypropyl) -tetramethyldisiloxane, epoxy group-containing silane compounds such as (3-glycidyloxypropyl) -pentamethyldisiloxane;

(Trimethylsilyl) [3- (trimethoxysilyl) propyl] sulfide, (trimethylsilyl) [3- (triethoxysilyl) propyl] sulfide, (trimethylsilyl) [3- (tripropoxysilyl) propyl] sulfide, (trimethylsilyl) [3 -(Tributoxysilyl) propyl] sulfide, (trimethylsilyl) [3- (methyldimethoxysilyl) propyl] sulfide, (trimethylsilyl) [3- (methyldiethoxysilyl) propyl] sulfide, (trimethylsilyl) [3- (methyldioxy) Sulfide group-containing silane compounds such as propoxysilyl) propyl] sulfide, (trimethylsilyl) [3- (methyldibutoxysilyl) propyl] sulfide;

N-substituted aziridine compounds such as ethyleneimine and propyleneimine; methyltriethoxysilane, N, N-bis (trimethylsilyl) -3-aminopropyltrimethoxysilane, N, N-bis (trimethylsilyl) -3-aminopropyltriethoxy Alkoxysilanes such as silane, N, N-bis (trimethylsilyl) aminoethyltrimethoxysilane, N, N-bis (trimethylsilyl) aminoethyltriethoxysilane; 4-N, N-dimethylaminobenzophenone, 4-N, N- Di-t-butylaminobenzophenone, 4-N, N-diphenylaminobenzophenone, 4,4′-bis (dimethylamino) benzophenone, 4,4′-bis (diethylamino) benzophenone, 4,4′-bis (diphenylamino) ) Benzophenone, N, N (Thio) benzophenone compounds having an amino group and / or a substituted amino group such as N ′, N′-bis- (tetraethylamino) benzophenone; 4-N, N-dimethylaminobenzaldehyde, 4-N, N-diphenylaminobenzaldehyde , A benzaldehyde compound having an amino group and / or a substituted amino group such as 4-N, N-divinylaminobenzaldehyde; N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, N-phenyl-2-pyrrolidone, N -T-butyl-2-pyrrolidone, N-substituted pyrrolidone such as N-methyl-5-methyl-2-pyrrolidone N-methyl-2-piperidone, N-vinyl-2-piperidone, N-phenyl-2-piperidone, etc. N-substituted piperidones; N-methyl-ε-caprolactam, N-phenyl-ε-capro N-substituted lactams such as octam, N-methyl-ω-laurylactam, N-vinyl-ω-laurylactam, N-methyl-β-propiolactam, N-phenyl-β-propiolactam other,

N, N-bis- (2,3-epoxypropoxy) -aniline, 4,4-methylene-bis- (N, N-glycidylaniline), tris- (2,3-epoxypropyl) -1,3,5 -Triazine-2,4,6-triones, N, N-diethylacetamide, N-methylmaleimide, N, N-diethylurea, 1,3-dimethylethyleneurea, 1,3-divinylethyleneurea, 1,3 -Diethyl-2-imidazolidinone, 1-methyl-3-ethyl-2-imidazolidinone, 4-N, N-dimethylaminoacetophene, 4-N, N-diethylaminoacetophenone, 1,3-bis (diphenyl) Amino) -2-propanone, 1,7-bis (methylethylamino) -4-heptanone, etc. can be mentioned. Of these, modified SBR modified with alkoxysilane is preferable.
In addition, modification | denaturation by the said compound (modifier) can be implemented by a well-known method.

The vinyl content of SBR is preferably 20% by mass or more, more preferably 30% by mass or more, and preferably 60% by mass or less, more preferably 40% by mass or less. Within the above range, the effects of the present invention tend to be obtained more favorably.
The vinyl amount (1,2-bonded butadiene unit amount) can be measured by the method described in the examples below.

The weight average molecular weight (Mw) of SBR is preferably 500,000 or more, more preferably 800,000 or more, and preferably 1.2 million or less, more preferably 1,000,000 or less. Within the above range, the effects of the present invention tend to be obtained more favorably.
Mw is based on a value measured by gel permeation chromatography (GPC) (GPC-8000 series manufactured by Tosoh Corp., detector: differential refractometer, column: TSKGEL SUPERMULTIPORE HZ-M manufactured by Tosoh Corp.). In standard polystyrene conversion.

When the rubber composition contains a plurality of SBRs, the “styrene amount” in the present invention means the average styrene amount of the plurality of SBRs, and when only one kind of SBR is contained, it means the styrene amount of the SBR. . The average styrene content of SBR is {Σ (content of each SBR × styrene content of each SBR)} / total content of all SBR. For example, when the rubber component is composed of 90% by mass of SBR (A) (styrene content 40% by mass), 5% by mass of SBR (B) (styrene content 25% by mass), and 5% by mass of BR, the average styrene content is 39. 21% by mass (= (90 × 40 + 5 × 25) / (90 + 5)). The styrene content (average styrene content) of SBR is preferably 20% by mass or more, more preferably 35% by mass or more, and preferably 60% by mass or less, more preferably 40% by mass or less. Within the above range, the effects of the present invention tend to be obtained more favorably.
The amount of styrene can be measured by the method described in the examples below.

As SBR, SBR manufactured and sold by Sumitomo Chemical Co., Ltd., JSR Co., Ltd., Asahi Kasei Co., Ltd., Nippon Zeon Co., Ltd., etc. can be used, for example.

Although content of SBR in 100 mass% of rubber components should just be 40-80 mass%, Preferably it is 50 mass% or more, More preferably, it is 65 mass% or more. Within the above range, the effects of the present invention tend to be obtained more favorably.

The rubber composition contains BR as a rubber component.
The BR is not particularly limited, and BR having a high cis content, BR having a low cis content, BR containing a syndiotactic polybutadiene crystal, and the like can be used. The BR may be either a non-modified BR or a modified BR. Examples of the modified BR include a modified BR in which the above-described functional group is introduced. These may be used alone or in combination of two or more. Of these, low-cis butadiene rubber (Loss BR) having a cis content of 50% by mass or less is preferred. The cis content of Rhosis BR is preferably 40% by mass or less, and preferably 5% by mass or more.
The cis content can be measured by infrared absorption spectrum analysis.

As BR, for example, products such as Ube Industries, JSR, Asahi Kasei, Nippon Zeon, and the like can be used.

In the case of containing Rhosis BR, the content of Rhosis BR in 100% by mass of the rubber component is preferably 10% by mass or more, more preferably 15% by mass or more, and preferably 30% by mass or less, preferably 25 It is below mass%. Within the above range, the effects of the present invention tend to be obtained more favorably.

The BR content in 100% by mass of the rubber component (the total content of Rhosis BR and other BRs) may be 10 to 35% by mass, preferably 15% by mass or more, more preferably 25% by mass or more. Moreover, Preferably it is 30 mass% or less. Within the above range, the effects of the present invention tend to be obtained more favorably.

Rubber components that can be used in addition to SBR and BR include diene systems such as isoprene rubber, acrylonitrile butadiene rubber (NBR), chloroprene rubber (CR), butyl rubber (IIR), and styrene-isoprene-butadiene copolymer rubber (SIBR). Rubber. These diene rubbers may be used alone or in combination of two or more.

The rubber composition contains silica.
Examples of the silica include dry process silica (anhydrous silicic acid), wet process silica (hydrous silicic acid) and the like, but wet process silica is preferred because of the large number of silanol groups. These may be used alone or in combination of two or more.

Nitrogen adsorption specific surface area _(N 2 SA) of silica is preferably 110m ² / g or more, more preferably 150 meters ² / g or more, more preferably 200 meters ² / g or more, particularly preferably 220 m ² / g or more, Moreover, Preferably it is 300 m < ² > / g or less, More preferably, it is 260 m < ² > / g or less. Within the above range, the effects of the present invention tend to be obtained more favorably.
The nitrogen adsorption specific surface area of silica is a value measured by the BET method according to ASTM D3037-81.

Examples of silica that can be used include products such as Degussa, Rhodia, Tosoh Silica, Solvay Japan, and Tokuyama.

The content of silica with respect to 100 parts by mass of the rubber component may be 80 parts by mass or more, preferably 90 parts by mass or more, more preferably 100 parts by mass or more, and preferably 130 parts by mass or less. Is 120 parts by mass or less. Within the above range, the effects of the present invention tend to be obtained more favorably.

The rubber composition preferably contains a silane coupling agent together with silica. Thereby, there exists a tendency for the effect of this invention to be acquired more favorably.
The silane coupling agent is not particularly limited. For example, bis (3-triethoxysilylpropyl) tetrasulfide, bis (2-triethoxysilylethyl) tetrasulfide, bis (4-triethoxysilylbutyl) tetrasulfide, Bis (3-trimethoxysilylpropyl) tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, bis (2-triethoxysilylethyl) trisulfide, bis (4-trimethoxysilylbutyl) trisulfide, bis ( 3-triethoxysilylpropyl) disulfide, bis (2-triethoxysilylethyl) disulfide, bis (4-triethoxysilylbutyl) disulfide, bis (3-trimethoxysilylpropyl) disulfide, bis (2-trimethoxysilyl ester) 3) disulfide, bis (4-trimethoxysilylbutyl) disulfide, 3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide, 2-triethoxysilylethyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3 -Sulfide systems such as triethoxysilylpropyl methacrylate monosulfide, mercapto systems such as 3-mercaptopropyltrimethoxysilane and 2-mercaptoethyltriethoxysilane, vinyl systems such as vinyltriethoxysilane and vinyltrimethoxysilane, 3-amino Amino-based compounds such as propyltriethoxysilane and 3-aminopropyltrimethoxysilane; glycidoxy-based compounds such as γ-glycidoxypropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane; Toro propyltrimethoxysilane, 3-nitro-triethoxysilane and nitro-based, 3-chloropropyl trimethoxy silane, chloro system such as 3-chloropropyl triethoxysilane and the like. These may be used alone or in combination of two or more. Among these, a sulfide type and a mercapto type are preferable, and a mercapto type is more preferable because the effects of the present invention can be obtained better.

As the mercapto-based silane coupling agent, a compound having a structure in which a mercapto group is protected by a protecting group (for example, a compound represented by the following formula (S1)) can be used in addition to a compound having a mercapto group. .

（式中、Ｒ^１００１は−Ｃｌ、−Ｂｒ、−ＯＲ^１００６、−Ｏ（Ｏ＝）ＣＲ^１００６、−ＯＮ＝ＣＲ^１００６Ｒ^１００７、−ＯＮ＝ＣＲ^１００６Ｒ^１００７、−ＮＲ^１００６Ｒ^１００７及び−（ＯＳｉＲ^１００６Ｒ^１００７）_ｈ（ＯＳｉＲ^１００６Ｒ^１００７Ｒ^１００８）から選択される一価の基（Ｒ^１００６、Ｒ^１００７及びＲ^１００８は同一でも異なっていても良く、各々水素原子又は炭素数１〜１８の一価の炭化水素基であり、ｈは平均値が１〜４である。）であり、Ｒ^１００２はＲ^１００１、水素原子又は炭素数１〜１８の一価の炭化水素基、Ｒ^１００３は−［Ｏ（Ｒ^１００９Ｏ）_ｊ］−基（Ｒ^１００９は炭素数１〜１８のアルキレン基、ｊは１〜４の整数である。）、Ｒ^１００４は炭素数１〜１８の二価の炭化水素基、Ｒ^１００５は炭素数１〜１８の一価の炭化水素基を示し、ｘ、ｙ及びｚは、ｘ＋ｙ＋２ｚ＝３、０≦ｘ≦３、０≦ｙ≦２、０≦ｚ≦１の関係を満たす数である。）

（式中、ｖは０以上の整数、ｗは１以上の整数である。Ｒ^１１は水素、ハロゲン、分岐若しくは非分岐の炭素数１〜３０のアルキル基、分岐若しくは非分岐の炭素数２〜３０のアルケニル基、分岐若しくは非分岐の炭素数２〜３０のアルキニル基、又は該アルキル基の末端の水素が水酸基若しくはカルボキシル基で置換されたものを示す。Ｒ^１２は分岐若しくは非分岐の炭素数１〜３０のアルキレン基、分岐若しくは非分岐の炭素数２〜３０のアルケニレン基、又は分岐若しくは非分岐の炭素数２〜３０のアルキニレン基を示す。Ｒ^１１とＲ^１２とで環構造を形成してもよい。） As a particularly suitable mercapto-based silane coupling agent, a silane coupling agent represented by the following formula (S1), a binding unit A represented by the following formula (I), and a coupling unit B represented by the following formula (II) Examples include silane coupling agents.

(In the formula, R ¹⁰⁰¹ represents —Cl, —Br, —OR ¹⁰⁰⁶ , —O (O═) CR ¹⁰⁰⁶ , —ON = CR ¹⁰⁰⁶ R ¹⁰⁰⁷ , —ON = CR ¹⁰⁰⁶ R ¹⁰⁰⁷ , —NR ¹⁰⁰⁶ R ¹⁰⁰⁷ and — ( The monovalent groups (R ¹⁰⁰⁶ , R ^1007, and R ¹⁰⁰⁸ ) selected from OSiR ¹⁰⁰⁶ R ¹⁰⁰⁷ ) _h (OSiR ¹⁰⁰⁶ R ¹⁰⁰⁷ R ¹⁰⁰⁸ ) may be the same or different and each have a hydrogen atom or a carbon number of 1 to 18 R is a monovalent hydrocarbon group, h has an average value of 1 to 4, and R ¹⁰⁰² is R ¹⁰⁰¹ , a hydrogen atom or a monovalent hydrocarbon group having 1 to 18 carbon atoms, and R ¹⁰⁰³ is − _{^{[O (R 1009 O) j}} ] - group ^{(. R 1009} represents an alkylene group having 1 to 18 carbon atoms, j is an integer from 1 to ^{4), R 1004} is from 1 to 18 carbon atoms Valent hydrocarbon ^{group, R 1005} represents a monovalent hydrocarbon group having 1 to 18 carbon atoms, x, y and z, x + y + 2z = 3,0 ≦ x ≦ 3,0 ≦ y ≦ 2,0 ≦ z It is a number that satisfies the relationship of ≦ 1.)

(In the formula, v is an integer of 0 or more, and w is an integer of 1 or more. R ¹¹ is hydrogen, halogen, a branched or unbranched alkyl group having 1 to 30 carbon atoms, a branched or unbranched carbon number of 2 to 2. 30 alkenyl groups, branched or unbranched alkynyl groups having 2 to 30 carbon atoms, or those in which the hydrogen at the terminal of the alkyl group is substituted with a hydroxyl group or a carboxyl group, R ¹² is branched or unbranched carbon number 1 to 30 represents an alkylene group, a branched or unbranched alkenylene group having 2 to 30 carbon atoms, or a branched or unbranched alkynylene group having 2 to 30 carbon atoms, wherein R ¹¹ and R ¹² form a ring structure. May be.)

In the formula (S1), R ¹⁰⁰⁵ , R ¹⁰⁰⁶ , R ¹⁰⁰⁷ and R ¹⁰⁰⁸ are each independently a linear, cyclic or branched alkyl group having 1 to 18 carbon atoms, an alkenyl group, an aryl group and an aralkyl group. A group selected from the group consisting of When R ¹⁰⁰² is a monovalent hydrocarbon group having 1 to 18 carbon atoms, it is selected from the group consisting of linear, cyclic or branched alkyl groups, alkenyl groups, aryl groups, and aralkyl groups. It is preferably a group. R ¹⁰⁰⁹ represents a linear, preferably a cyclic or branched alkylene group, particularly preferably a straight-chain. R ¹⁰⁰⁴ is, for example, an alkylene group having 1 to 18 carbon atoms, an alkenylene group having 2 to 18 carbon atoms, a cycloalkylene group having 5 to 18 carbon atoms, a cycloalkylalkylene group having 6 to 18 carbon atoms, or an arylene having 6 to 18 carbon atoms. And aralkylene groups having 7 to 18 carbon atoms. The alkylene group and alkenylene group may be either linear or branched, and the cycloalkylene group, cycloalkylalkylene group, arylene group, and aralkylene group have a functional group such as a lower alkyl group on the ring. You may do it. As R ¹⁰⁰⁴ , an alkylene group having 1 to 6 carbon atoms is preferable, and a linear alkylene group such as a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, or a hexamethylene group is particularly preferable.

Specific examples of R ¹⁰⁰² , R ¹⁰⁰⁵ , R ¹⁰⁰⁶ , R ¹⁰⁰⁷ and R ¹⁰⁰⁸ in formula (S1) include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl. Group, tert-butyl group, pentyl group, hexyl group, octyl group, decyl group, dodecyl group, cyclopentyl group, cyclohexyl group, vinyl group, propenyl group, allyl group, hexenyl group, octenyl group, cyclopentenyl group, cyclo Hexenyl group, phenyl group, tolyl group, xylyl group, naphthyl group, benzyl group, phenethyl group, naphthylmethyl group and the like can be mentioned.
Examples of R ¹⁰⁰⁹ in Formula (S1), the linear alkylene group include a methylene group, an ethylene group, n- propylene, n- butylene, hexylene and the like, and the branched alkylene group, An isopropylene group, an isobutylene group, a 2-methylpropylene group, etc. are mentioned.

Specific examples of the silane coupling agent represented by the formula (S1) include 3-hexanoylthiopropyltriethoxysilane, 3-octanoylthiopropyltriethoxysilane, 3-decanoylthiopropyltriethoxysilane, 3- Lauroylthiopropyltriethoxysilane, 2-hexanoylthioethyltriethoxysilane, 2-octanoylthioethyltriethoxysilane, 2-decanoylthioethyltriethoxysilane, 2-lauroylthioethyltriethoxysilane, 3-hexanoyl Ruthiopropyltrimethoxysilane, 3-octanoylthiopropyltrimethoxysilane, 3-decanoylthiopropyltrimethoxysilane, 3-lauroylthiopropyltrimethoxysilane, 2-hexanoylthioethyltrimethoxysilane, 2-o Motor noise Lucio ethyltrimethoxysilane, 2- deca Neu thio ethyltrimethoxysilane, and 2-lauroyl thio ethyl trimethoxysilane. These may be used alone or in combination of two or more. Of these, 3-octanoylthiopropyltriethoxysilane is particularly preferable.

In the silane coupling agent containing the bonding unit A represented by the formula (I) and the coupling unit B represented by the formula (II), the content of the bonding unit A is preferably 30 mol% or more, more preferably 50 mol. % Or more, preferably 99 mol% or less, more preferably 90 mol% or less. Further, the content of the binding unit B is preferably 1 mol% or more, more preferably 5 mol% or more, still more preferably 10 mol% or more, preferably 70 mol% or less, more preferably 65 mol% or less, More preferably, it is 55 mol% or less. Further, the total content of the binding units A and B is preferably 95 mol% or more, more preferably 98 mol% or more, and particularly preferably 100 mol%.
The content of the bond units A and B is an amount including the case where the bond units A and B are located at the terminal of the silane coupling agent. The form in the case where the bonding units A and B are located at the end of the silane coupling agent is not particularly limited as long as the units corresponding to the formulas (I) and (II) indicating the bonding units A and B are formed. .

Regarding R ¹¹ in formulas (I) and (II), examples of the halogen include chlorine, bromine, and fluorine. Examples of the branched or unbranched alkyl group having 1 to 30 carbon atoms include a methyl group and an ethyl group. Examples of the branched or unbranched alkenyl group having 2 to 30 carbon atoms include vinyl group and 1-propenyl group. Examples of the branched or unbranched alkynyl group having 2 to 30 carbon atoms include ethynyl group and propynyl group.

Regarding R ¹² in the formulas (I) and (II), examples of the branched or unbranched alkylene group having 1 to 30 carbon atoms include an ethylene group and a propylene group. Examples of the branched or unbranched C2-C30 alkenylene group include vinylene group and 1-propenylene group. Examples of the branched or unbranched alkynylene group having 2 to 30 carbon atoms include an ethynylene group and a propynylene group.

In the silane coupling agent containing the binding unit A represented by the formula (I) and the coupling unit B represented by the formula (II), the number of repeating units (v) of the connecting unit A and the number of repeating units (w) of the connecting unit B The total number of repetitions (v + w) is preferably in the range of 3 to 300.

When the silane coupling agent is contained, the content of the silane coupling agent is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, and preferably 20 parts by mass with respect to 100 parts by mass of silica. Hereinafter, it is more preferably 15 parts by mass or less. Within the above range, the effects of the present invention tend to be obtained more favorably.

The rubber composition contains a terpene resin.
As the terpene resin, a polyterpene resin obtained by polymerizing a terpene compound, an aromatic modified terpene resin obtained by polymerizing a terpene compound and an aromatic compound, or the like can be used. These hydrogenated products can also be used.

The polyterpene resin is a resin obtained by polymerizing a terpene compound. The terpene compound is a hydrocarbon represented by a composition of (C ₅ H ₈ ) _n and an oxygen-containing derivative thereof. Monoterpene (C ₁₀ H ₁₆ ), sesquiterpene (C ₁₅ H ₂₄ ), diterpene (C ₂₀ H ₃₂₎ Terpenes having a basic skeleton classified into, for example, α-pinene, β-pinene, dipentene, limonene, myrcene, alloocimene, ocimene, α-ferrandrene, α-terpinene, γ-terpinene, terpinolene 1,8-cineole, 1,4-cineole, α-terpineol, β-terpineol, γ-terpineol and the like.

Examples of the polyterpene resin include a pinene resin, a limonene resin, a dipentene resin, and a pinene / limonene resin made from the above-mentioned terpene compound. Of these, pinene resin is preferred. The pinene resin usually contains both α-pinene and β-pinene having an isomer relationship, but due to the difference in the components contained, β-pinene resin containing β-pinene as a main component and α-pinene It is classified into α-pinene resin mainly composed of pinene.

Examples of the aromatic modified terpene resin include terpene phenol resins using terpene compounds and phenolic compounds as raw materials, and terpene styrene resins using terpene compounds and styrene compounds as raw materials. Moreover, the terpene phenol styrene resin which uses a terpene compound, a phenol type compound, and a styrene type compound as a raw material can also be used.

As the terpene-based resin, a polyterpene resin is preferable and a β-pinene resin is more preferable because the effect of the present invention tends to be obtained better.

The weight average molecular weight (Mw) of the terpene resin is preferably 1000 or more, more preferably 2350 or more, and is preferably 5000 or less, more preferably 4000 or less. Within the above range, the effects of the present invention tend to be obtained more favorably.

The number average molecular weight (Mn) of the terpene resin is preferably 500 or more, more preferably 830 or more, and preferably 3000 or less, more preferably 2000 or less. Within the above range, the effects of the present invention tend to be obtained more favorably.
Mn can be obtained by the same method as Mw.

The content of the terpene resin relative to 100 parts by mass of the rubber component may be 10 to 60 parts by mass, preferably 20 parts by mass or more, more preferably 35 parts by mass or more, and still more preferably 40 parts by mass or more. Moreover, Preferably it is 55 mass parts or less, More preferably, it is 45 mass parts or less. Within the above range, the effects of the present invention tend to be obtained more favorably.

In the rubber composition, the SBR styrene content and the terpene resin content satisfy the following formula (A).
(A) α / β ≦ 3
α: Styrene content of styrene-butadiene rubber [% by mass]
β: Content of terpene resin relative to 100 parts by mass of rubber component [parts by mass]

In the formula (A), α / β may be 3 or less, preferably 2 or less, and preferably 0.5 or more, more preferably 0.9 or more. Within the above range, the effects of the present invention tend to be obtained more favorably.

The rubber composition may contain other resins in addition to the terpene resin. Other resins are not particularly limited as long as they are widely used in the tire industry. Rosin resins, coumarone indene resins, styrene resins, pt-butylphenol acetylene resins, acrylic resins, C5 resins, C9 resin etc. are mentioned. These may be used alone or in combination of two or more.

Examples of commercially available terpene resins and other resins include Maruzen Petrochemical Co., Ltd., Sumitomo Bakelite Co., Ltd., Yashara Chemical Co., Ltd., Tosoh Corp., Rutgers Chemicals, BASF, Arizona Chemical, Japan Products such as Nikko Chemical Co., Ltd., Nippon Shokubai Co., Ltd., JX Energy Co., Ltd., Arakawa Chemical Industry Co., Ltd., Taoka Chemical Industry Co., Ltd. can be used.

The rubber composition preferably contains carbon black. Thereby, there exists a tendency for the effect of this invention to be acquired more favorably.
The carbon black is not particularly limited, and examples thereof include N134, N110, N220, N234, N219, N339, N330, N326, N351, N550, and N762. These may be used alone or in combination of two or more.

The specific surface area of cetyltrimethylammonium bromide (CTAB) of carbon black is preferably 130 m ² / g or more, more preferably 135 m ² / g or more, and preferably 200 m ² / g or less, more preferably 150 m ² / g. It is as follows. Within the above range, the effects of the present invention tend to be obtained more favorably.
The CTAB specific surface area of carbon black is a value measured according to JIS K6217-3: 2001.

The nitrogen adsorption specific surface area (N ₂ SA) of carbon black is preferably 120 m ² / g or more, more preferably 146 m ² / g or more, and preferably 200 m ² / g or less, more preferably 180 m ² / g. It is as follows. Within the above range, the effects of the present invention tend to be obtained more favorably.
The N ₂ SA of carbon black is a value measured according to JIS K6217-2: 2001.

Examples of carbon black include products such as Asahi Carbon Co., Ltd., Cabot Japan Co., Ltd., Tokai Carbon Co., Ltd., Mitsubishi Chemical Co., Ltd., Lion Co., Ltd., Shin-Nikka Carbon Co., Ltd., Columbia Carbon Co., etc. Can be used.

When carbon black is contained, the content of carbon black is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and preferably 20 parts by mass or less, with respect to 100 parts by mass of the rubber component. Preferably it is 15 mass parts or less. Within the above range, the effect of the present invention can be more suitably obtained.

In the rubber composition, the content of silica and the content of carbon black preferably satisfy the following formula (B). Thereby, there exists a tendency for the effect of this invention to be acquired more favorably.
(B) γ1 / γ2 ≦ 0.4
γ1: content of carbon black with respect to 100 parts by mass of rubber component [parts by mass]
γ2: Silica content with respect to 100 parts by mass of rubber component [parts by mass]

In the formula (B), γ1 / γ2 may be 0.4 or less, preferably 0.2 or less, more preferably 0.1 or less, and preferably 0.01 or more, more preferably 0.03 or more. Within the above range, the effects of the present invention tend to be obtained more favorably.

The rubber composition preferably contains a plasticizer. Thereby, there exists a tendency for the effect of this invention to be acquired more favorably.
The plasticizer is a material that imparts plasticity to the rubber component, and includes oil, liquid rubber, wax, and the like in addition to the resin such as the terpene resin described above. Specifically, it is a component extracted from the rubber composition using acetone.

The content of the plasticizer (the total content of the terpene resin and the other plasticizer) is preferably 40 parts by mass or more, more preferably 53 parts by mass or more, and still more preferably with respect to 100 parts by mass of the rubber component. It is 63 parts by mass or more, preferably 100 parts by mass or less, more preferably 90 parts by mass or less. Within the above range, the effect of the present invention can be more suitably obtained.

Examples of the oil include process oil, vegetable oil and fat, or a mixture thereof. As the process oil, for example, a paraffin process oil, an aroma process oil, a naphthene process oil, or the like can be used. As vegetable oils and fats, castor oil, cottonseed oil, sesame oil, rapeseed oil, soybean oil, palm oil, palm oil, peanut oil, rosin, pine oil, pineapple, tall oil, corn oil, rice bran oil, beet flower oil, sesame oil, Examples include olive oil, sunflower oil, palm kernel oil, camellia oil, jojoba oil, macadamia nut oil, and tung oil. These may be used alone or in combination of two or more. Among these, process oil is preferable and aroma-based process oil is more preferable because the effects of the present invention can be obtained satisfactorily.

When oil is contained, the oil content is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, and preferably 50 parts by mass or less, more preferably 100 parts by mass of the rubber component. It is 40 parts by mass or less. Within the above range, the effects of the present invention tend to be obtained more favorably.

Examples of the liquid rubber include liquid butadiene rubber (liquid BR), liquid styrene butadiene rubber (liquid SBR), and liquid isoprene rubber (liquid IR). These liquid rubbers may be used alone or in combination of two or more. Of these, liquid BR and liquid SBR are preferable.

As the liquid rubber, for example, a product such as Sertomer Company Inc. can be used.

When the liquid rubber is contained, the content of the liquid rubber is preferably 10 parts by mass or more, more preferably 20 parts by mass or more, and preferably 50 parts by mass or less, with respect to 100 parts by mass of the rubber component. Preferably it is 40 mass parts or less. Within the above range, the effects of the present invention tend to be obtained more favorably.

The wax is not particularly limited, and examples thereof include petroleum waxes such as paraffin wax and microcrystalline wax; natural waxes such as plant waxes and animal waxes; synthetic waxes such as polymers such as ethylene and propylene. These may be used alone or in combination of two or more. Of these, petroleum wax is preferable, and paraffin wax is more preferable.

As the wax, for example, products such as Ouchi Shinsei Chemical Co., Ltd., Nippon Seiwa Co., Ltd., Seiko Chemical Co., Ltd. can be used.

When the wax is contained, the content of the wax is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and preferably 20 parts by mass or less, more preferably 100 parts by mass of the rubber component. It is 10 parts by mass or less. Within the above range, the effects of the present invention tend to be obtained more favorably.

The rubber composition may contain an anti-aging agent.
Examples of the antiaging agent include naphthylamine type antiaging agents such as phenyl-α-naphthylamine; diphenylamine type antiaging agents such as octylated diphenylamine and 4,4′-bis (α, α′-dimethylbenzyl) diphenylamine; N -Isopropyl-N'-phenyl-p-phenylenediamine, N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine, N, N'-di-2-naphthyl-p-phenylenediamine, etc. P-phenylenediamine-based antioxidants; quinoline-based antioxidants such as 2,2,4-trimethyl-1,2-dihydroquinoline polymer; 2,6-di-t-butyl-4-methylphenol; Monophenolic antioxidants such as styrenated phenol; tetrakis- [methylene-3- (3 ', 5'-di-t-butyl- '- hydroxyphenyl) propionate] bis methane, tris, polyphenolic antioxidants, and the like. These may be used alone or in combination of two or more. Of these, p-phenylenediamine-based antioxidants and quinoline-based antioxidants are preferable.

As the anti-aging agent, for example, products such as Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., Ouchi Shinsei Chemical Co., Ltd., and Flexis Co. can be used.

When the anti-aging agent is contained, the content of the anti-aging agent is preferably 1 part by mass or more, more preferably 4 parts by mass or more, and preferably 10 parts by mass or less with respect to 100 parts by mass of the rubber component. More preferably, it is 8 parts by mass or less. Within the above range, the effects of the present invention tend to be obtained more favorably.

The rubber composition may contain stearic acid.
A conventionally well-known thing can be used as a stearic acid, For example, products, such as NOF Corporation, NOF company, Kao Corporation, FUJIFILM Wako Pure Chemicals Co., Ltd., and Chiba fatty acid company, can be used.

When stearic acid is contained, the content of stearic acid is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and preferably 10 parts by mass or less, based on 100 parts by mass of the rubber component. Preferably it is 5 mass parts or less. Within the above range, the effects of the present invention tend to be obtained more favorably.

The rubber composition may contain zinc oxide.
Conventionally known zinc oxide can be used, for example, Mitsui Kinzoku Mining Co., Ltd., Toho Zinc Co., Ltd., Hakusui Tech Co., Ltd., Shodo Chemical Industry Co., Ltd., Sakai Chemical Industry Co., Ltd. Can be used.

When zinc oxide is contained, the content of zinc oxide is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and preferably 10 parts by mass or less, relative to 100 parts by mass of the rubber component. Preferably it is 5 mass parts or less. Within the above range, the effects of the present invention tend to be obtained more favorably.

The rubber composition may contain sulfur.
Examples of sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersible sulfur, soluble sulfur and the like generally used in the rubber industry. These may be used alone or in combination of two or more.

As the sulfur, for example, products such as Tsurumi Chemical Co., Ltd., Karuizawa Sulfur Co., Ltd., Shikoku Kasei Kogyo Co., Ltd., Flexis Co., Nihon Kiboshi Kogyo Co., Ltd., Hosoi Chemical Co., Ltd. can be used.

When sulfur is contained, the content of sulfur is preferably 0.5 parts by mass or more, more preferably 1.5 parts by mass or more, and preferably 10 parts by mass or less with respect to 100 parts by mass of the rubber component. More preferably, it is 5 parts by mass or less. Within the above range, the effects of the present invention tend to be obtained more favorably.

The rubber composition may contain a vulcanization accelerator.
Examples of the vulcanization accelerator include thiazole vulcanization accelerators such as 2-mercaptobenzothiazole, di-2-benzothiazolyl disulfide, N-cyclohexyl-2-benzothiazylsulfenamide; tetramethylthiuram disulfide (TMTD ), Tetrabenzylthiuram disulfide (TBzTD), tetrakis (2-ethylhexyl) thiuram disulfide (TOT-N), and other thiuram vulcanization accelerators; N-cyclohexyl-2-benzothiazolesulfenamide, Nt-butyl- 2-benzothiazolylsulfenamide, N-oxyethylene-2-benzothiazole sulfenamide, N-oxyethylene-2-benzothiazole sulfenamide, N, N′-diisopropyl-2-benzothiazole sulfenamide, etc. Sulfena De-based vulcanization accelerator; diphenylguanidine, it may be mentioned di-ortho-tolyl guanidine, guanidine-based vulcanization accelerators such as ortho tri ruby guanidine. These may be used alone or in combination of two or more. Of these, sulfenamide-based vulcanization accelerators and guanidine-based vulcanization accelerators are preferred because the effects of the present invention can be obtained more suitably.

When the vulcanization accelerator is contained, the content of the vulcanization accelerator is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, and preferably 10 parts by mass with respect to 100 parts by mass of the rubber component. Part or less, more preferably 8 parts by weight or less. Within the above range, the effects of the present invention tend to be obtained more favorably.

In addition to the above components, the rubber composition includes additives generally used in the tire industry, such as organic peroxides; fillers such as calcium carbonate, talc, alumina, clay, aluminum hydroxide, and mica. Etc. may be further blended. The content of these additives is preferably 0.1 to 200 parts by mass with respect to 100 parts by mass of the rubber component.

The rubber composition can be produced, for example, by a method of kneading the above components using a rubber kneading apparatus such as an open roll or a Banbury mixer, and then vulcanizing.

As kneading conditions, in the base kneading step in which additives other than the vulcanizing agent and the vulcanization accelerator are kneaded, the kneading temperature is usually 100 to 180 ° C, preferably 120 to 170 ° C. In the final kneading step of kneading the vulcanizing agent and vulcanization accelerator, the kneading temperature is usually 120 ° C. or lower, preferably 85 to 110 ° C. Further, a composition obtained by kneading a vulcanizing agent and a vulcanization accelerator is usually subjected to vulcanization treatment such as press vulcanization. The vulcanization temperature is usually 140 to 190 ° C, preferably 150 to 185 ° C. The vulcanization time is usually 5 to 15 minutes.

The rubber composition is suitably used for treads (cap treads), but for members other than treads, for example, sidewalls, base treads, under treads, clinch apex, bead apex, breaker cushion rubber, carcass cord coating It may be used for rubber, insulation, chafers, inner liners, etc., or side reinforcement layers for run-flat tires.

The pneumatic tire of the present invention is produced by a usual method using the rubber composition.
That is, the rubber composition is extruded in accordance with the shape of each tire member of the tread at an unvulcanized stage, and molded together with other tire members by a normal method on a tire molding machine. Form a vulcanized tire. The unvulcanized tire is heated and pressurized in a vulcanizer to obtain a tire.

The pneumatic tire can be used for passenger car tires, truck / bus tires, motorcycle tires, high performance tires, and the like, and is particularly suitable for passenger car tires.

The present invention will be specifically described based on examples, but the present invention is not limited to these examples.
The various chemicals used in the examples are described below.
SBR1: modified SBR synthesized in the following Production Example 1 (styrene content: 40% by mass, vinyl content: 30% by mass, Mw: 950,000)
SBR2: SLR6430 manufactured by Dow Chemical (styrene content: 40% by mass, vinyl content: 24% by mass, Mw: 1 million, containing 37.5 parts by mass of oil with respect to 100 parts by mass of rubber solid content)
BR1: BR710 manufactured by Ube Industries, Ltd. (cis content: 90% by mass or more)
BR2: N103 manufactured by Asahi Kasei Chemicals Corporation (cis content: 38% by mass)
Carbon black: N134 (CTAB: 135 m ² / g, N ₂ SA: 146 m ² / g)
Silica 1: Ultrasil 9000GR manufactured by Evonik Degussa (N ₂ SA: 240 m ² / g)
Silica 2: Ultrasil VN3 (N ₂ SA: 167 m ² / g) manufactured by Evonik Degussa
Silica 3: ZEOSIL 1115MP (N ₂ SA: 115 m ² / g) manufactured by Rhodia
Silane coupling agent 1: NXT-Z45 manufactured by Momentive (copolymer of bonding unit A and bonding unit B (bonding unit A: 55 mol%, bonding unit B: 45 mol%))
Silane coupling agent 2: NXT (3-octanoylthiopropyltriethoxysilane) manufactured by Momentive
Silane coupling agent 3: Si266 (bis (3-triethoxysilylpropyl) disulfide) manufactured by Evonik Degussa
Oil: VIVETEC500 (TDAE oil) manufactured by H & R
Terpene resin: Sylvatrax 4150 manufactured by Arizona Chemical Co. (β-pinene resin, β-pinene content: 98% by mass or more, Mw: 2350, Mn: 830)
Wax: Ozoace 0355 manufactured by Nippon Seiwa Co., Ltd.
Anti-aging agent 1: NOCRACK 6C (N- (1,3-dimethylbutyl) -N′-phenyl-p-phenylenediamine) manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.
Anti-aging agent 2: Nocrack RD (poly (2,2,4-trimethyl-1,2-dihydroquinoline)) manufactured by Ouchi Shinsei Chemical Co., Ltd.
Stearic acid: Stearic acid “椿” manufactured by NOF Corporation
Zinc oxide: Zinc Hua No. 1 manufactured by Mitsui Mining & Smelting Co., Ltd. Sulfur: Powder sulfur vulcanization accelerator manufactured by Tsurumi Chemical Co., Ltd. 1: Noxeller NS (N-tert-butyl manufactured by Ouchi Shinsei Chemical Co., Ltd.) -2-Benzothiazolylsulfenamide)
Vulcanization accelerator 2: Noxeller D (1,3-diphenylguanidine) manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.

(Production Example 1)
A nitrogen-substituted autoclave reactor was charged with cyclohexane, tetrahydrofuran, styrene, and 1,3-butadiene. After adjusting the temperature of the reactor contents to 20 ° C., n-butyllithium was added to initiate polymerization. Polymerization was performed under adiabatic conditions, and the maximum temperature reached 85 ° C. When the polymerization conversion rate reached 99%, 1,3-butadiene was added, and after further polymerizing for 5 minutes, N, N-bis (trimethylsilyl) -3-aminopropyltriethoxysilane was added as a modifier. Reaction was performed. After completion of the polymerization reaction, 2,6-di-tert-butyl-p-cresol was added. Subsequently, the solvent was removed by steam stripping, and drying was performed with a hot roll adjusted to 110 ° C. to obtain SBR1.

(Analysis of SBR)
The structural identification of SBR (measurement of styrene content and vinyl content) was performed using a JNM-ECA series apparatus manufactured by JEOL Ltd. The measurement was performed after drying under reduced pressure, by dissolving 0.1 g of the polymer in 15 ml of toluene, slowly pouring it into 30 ml of methanol and reprecipitating it.

(Examples and Comparative Examples)
In accordance with the formulation shown in Table 1, materials other than sulfur and a vulcanization accelerator were kneaded for 5 minutes at 150 ° C. using a 1.7 L Banbury mixer manufactured by Kobe Steel, Ltd. Obtained. Next, sulfur and a vulcanization accelerator were added to the obtained kneaded product, and kneaded for 5 minutes under the condition of 80 ° C. using an open roll to obtain an unvulcanized rubber composition. The obtained unvulcanized rubber composition is formed into a tread shape and bonded together with other tire members to form an unvulcanized tire, press vulcanized at 150 ° C. for 12 minutes, and a test tire ( Size: 195 / 65R15). The following evaluation was performed using the obtained test tire, and the results are shown in Table 1.
In Table 1, the rubber content in the oil-extended rubber is described in the rubber column, and the oil content in the oil-extended rubber is added to the oil column. In the column of the plasticizer content, the total amount of oil, terpene resin, and wax is described.

(Low fuel consumption)
Using a rolling resistance tester, the rolling resistance when each test tire was run at a rim (15 × 6JJ), internal pressure (230 kPa), load (3.43 kN), speed (80 km / h) was measured, The index was expressed as an index when the comparative example 1 was set to 100 (low fuel consumption index). A larger index indicates better fuel efficiency. In this embodiment, the target is 180 or more.

(Abrasion resistance)
Install each test tire on all wheels of a vehicle (domestic FF2000cc), measure the groove depth of the tire tread after a running distance of 8000km, calculate the running distance when the tire groove depth decreases by 1mm, and compare The results are shown as an index when Example 1 is 100 (wear resistance index). The larger the index, the longer the travel distance when the tire groove depth is reduced by 1 mm, and the better the wear resistance. In this embodiment, the target is 70 or more.

(Dry grip performance)
Each test tire was mounted on all wheels of a vehicle (domestic FF2000cc), and the vehicle traveled 10 laps on a dry asphalt road test course. The test place was Okayama test course of Sumitomo Rubber Industries, Ltd., and the temperature was 20-25 ° C. Then, the test driver evaluated the stability of the control during steering at that time, and displayed as an index when the comparative example 1 was set to 100 (dry grip performance index). The larger the index, the better the grip performance on the dry road surface. In this embodiment, the target is 70 or more.

(Wet grip performance)
Each test tire was mounted on all wheels of a vehicle (domestic FF2000cc), the braking distance from the initial speed of 100 km / h was obtained on the wet asphalt road surface, and displayed as an index when Comparative Example 1 was set to 100 (wet Grip performance index). The larger the index, the shorter the braking distance and the better the wet grip performance. In the present embodiment, the target is 150 or more.

Claims (10)

A rubber component having a styrene-butadiene rubber content of 40 to 80% by mass and a butadiene rubber content of 10 to 35% by mass;
Silica having a content of 80 parts by mass or more based on 100 parts by mass of the rubber component;
Containing 10 to 60 parts by mass of a terpene resin with respect to 100 parts by mass of the rubber component;
A tire rubber composition satisfying the following formula (A).
(A) α / β ≦ 3
α: Styrene content of styrene-butadiene rubber [% by mass]
β: Content of terpene resin relative to 100 parts by mass of rubber component [parts by mass] The tire rubber composition according to claim 1, comprising carbon black having a cetyltrimethylammonium bromide specific surface area of 130 m ² / g or more. The rubber composition for tires according to claim 1 or 2, wherein the styrene-butadiene rubber has a styrene content of 35% by mass or more. The rubber composition for tires in any one of Claims 1-3 which satisfy | fills following formula (B).
(B) γ1 / γ2 ≦ 0.1
γ1: content of carbon black with respect to 100 parts by mass of rubber component [parts by mass]
γ2: Silica content with respect to 100 parts by mass of rubber component [parts by mass] The tire rubber composition according to claim 1, wherein the silica has a nitrogen adsorption specific surface area of 220 m ² / g or more. The rubber composition for a tire according to any one of claims 1 to 5, wherein a content of the silica is 100 to 130 parts by mass with respect to 100 parts by mass of the rubber component. The rubber composition for tires according to any one of claims 1 to 6, comprising a mercapto silane coupling agent. The rubber composition for tires according to any one of claims 1 to 7, wherein, in 100% by mass of the rubber component, the content of a low-cis butadiene rubber having a cis content of 50% by mass or less is 10% by mass or more. The rubber composition for a tire according to any one of claims 1 to 8, wherein a content of the plasticizer with respect to 100 parts by mass of the rubber component is 40 parts by mass or more. The pneumatic tire produced using the rubber composition in any one of Claims 1-9.