JP7035520B2 - Rubber composition for tires and pneumatic tires - Google Patents

Description

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

In recent years, due to growing interest in environmental issues, not only are automobiles required to have lower fuel consumption, but also rubber compositions used in automobile tires are required to be provided with good wear resistance and the like. There is.

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 demand, styrene-butadiene rubber is widely used as a rubber component, but its wear resistance tends to decrease. As described above, the grip performance and the wear resistance are in conflict with each other, and it is difficult to obtain the respective performances in a well-balanced manner.

INDUSTRIAL APPLICABILITY The present invention provides a rubber composition for a tire having improved dry grip performance, wet grip performance and wear resistance in a well-balanced manner, and a pneumatic tire produced by using the rubber composition. The purpose.

The present invention comprises a rubber component having a styrene-butadiene rubber content of 40 to 80% by mass, a butadiene rubber content of 10 to 30% by mass, and an isoprene-based rubber content of 10 to 30% by mass, and the rubber component. Silica having a content of 70 parts by mass or more with respect to 100 parts by mass, a liquid plasticizer having a content of 1 to 50 parts by mass with respect to 100 parts by mass of the rubber component, and a content of 1 to 50 parts by mass with respect to 100 parts by mass of the rubber component. The present invention relates to a rubber composition for a tire, which contains a C5 resin and satisfies the following formula (A).
(A) α1 / α2 ≧ 1
α1: Content of liquid plasticizer with respect to 100 parts by mass of rubber component [parts by mass]
α2: Content of C5 resin with respect 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 150 m ² / g or more.

The average amount of styrene in the styrene-butadiene rubber is preferably 30% by mass or less.

The rubber composition preferably contains carbon black and satisfies the following formula (B).
(B) β1 / β2 ≦ 0.1
β1: Content of carbon black with respect to 100 parts by mass of rubber component [parts by mass]
β2: 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.

The content of the silica with respect to 100 parts by mass of the rubber component is preferably 100 to 130 parts by mass.

The rubber composition preferably contains a mercapto-based silane coupling agent.

The content of the liquid plasticizer with respect to 100 parts by mass of the rubber component is preferably 25 to 50 parts by mass.

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

According to the present invention, the tire rubber composition contains styrene-butadiene rubber, butadiene rubber, isoprene-based rubber, silica, liquid plasticizer, and C5-based resin in predetermined amounts and satisfies the formula (A). Therefore, it is a dry grip. Performance, wet grip performance and wear resistance can be improved in a well-balanced manner.

The rubber composition for a tire of the present invention contains a predetermined amount of styrene-butadiene rubber (SBR), butadiene rubber (BR), isoprene-based rubber, silica, liquid plasticizer and C5-based resin, and satisfies the formula (A).

The above-mentioned rubber composition has the above-mentioned effect, and it is presumed that this is achieved by the following action and effect.
When SBR is used as the main component of the rubber component, the grip performance tends to be improved, but the wear resistance tends to decrease. On the other hand, in the above rubber composition, BR and isoprene-based rubber are used as rubber components other than SBR, the ratios thereof are adjusted, and the amount of silica, the amount of liquid plasticizer, and the amount of C5-based resin are also specified. By adjusting the ratio, the silica, the liquid plasticizer, and the C5 resin are well dispersed in the rubber composition. As a result, it is considered that the dry grip performance, the wet grip performance and the wear resistance are significantly (synergistically) improved in a well-balanced manner.

The rubber composition contains SBR as a rubber component.
The SBR is not particularly limited, and for example, emulsion-polymerized styrene-butadiene rubber (E-SBR), solution-polymerized styrene-butadiene rubber (S-SBR) and the like can be used. The SBR may be either a non-modified SBR or a 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 end of the SBR is modified with a compound having the above functional group (modifying agent). SBR (end-modified SBR having the above functional group at the end), main chain-modified SBR having the above-mentioned functional group in the main chain, and main chain-end-modified SBR having the above-mentioned functional group at the main chain and the end (for example, to the main chain) Main chain terminal modified SBR having the above functional group and having at least one end modified with the above modifying agent) or a polyfunctional compound having two or more epoxy groups in the molecule, which is modified (coupled) and has a hydroxyl group. And end-modified SBR into which an epoxy group has been introduced.

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

（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, an SBR modified with a compound (modifying agent) represented by the following formula is particularly suitable.

(In the formula, R ¹ , R ² and R ³ represent the same or different alkyl group, alkoxy group, silyloxy group, acetal group, carboxyl group (-COOH), mercapto group (-SH) or derivatives thereof. R ⁴ and R ⁵ may be the same or different and represent a hydrogen atom or an alkyl group. R ⁴ and R ⁵ may be combined to form a ring structure with a nitrogen atom. N represents an integer.)

The modified SBR modified by the compound (modifying agent) represented by the above formula includes, among others, the polymerization terminal (active terminal) of solution-polymerized styrene-butadiene rubber (S-SBR) using the compound represented by the above formula. Modified SBR (modified SBR or the like described in JP-A-2010-111753) is preferably used.

Alkoxy groups are suitable for R ¹ , R ² and R ³ (preferably an alkoxy group having 1 to 8 carbon atoms, and more preferably an alkoxy group having 1 to 4 carbon atoms). As R ⁴ and R ⁵ , an alkyl group (preferably an alkyl group having 1 to 3 carbon atoms) is suitable. n is preferably 1 to 5, more preferably 2 to 4, and even more preferably 3. Further, when R ⁴ and R ⁵ are bonded to form a ring structure together with a nitrogen atom, a 4- to 8-membered ring is preferable. The alkoxy group also includes a cycloalkoxy group (cyclohexyloxy group, etc.) and an aryloxy group (phenoxy group, benzyloxy group, etc.).

Specific examples of the above modifier include 2-dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 2-dimethylaminoethyltriethoxysilane, 3-dimethylaminopropyltriethoxysilane, and 2-diethylaminoethyltri. Examples thereof include methoxysilane, 3-diethylaminopropyltrimethoxysilane, 2-diethylaminoethyltriethoxysilane, 3-diethylaminopropyltriethoxysilane and the like. 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, a modified SBR modified with the following compound (modifying agent) can also be preferably used. Examples of the modifier include polyglycidyl ethers of polyvalent alcohols such as ethylene glycol diglycidyl ether, glycerin triglycidyl ether, trimethylol ethane triglycidyl ether, and trimethylol propane triglycidyl ether; and two or more diglycidylated bisphenol A and the like. Polyepoxidic compounds such as 1,4-diglycidylbenzene, 1,3,5-triglycidylbenzene, polyepoxidized liquid polybutadiene; 4,4'-diglycidyl-diphenyl Epoxide group-containing tertiary amines such as methylamine, 4,4'-diglycidyl-dibenzylmethylamine; diglycidylaniline, N, N'-diglycidyl-4-glycidyloxyaniline, diglycidyl orthotoluidine, tetraglycidylmethoxylenidin. , Tetraglycidylaminodiphenylmethane, tetraglycidyl-p-phenylenediamine, diglycidylaminomethylcyclohexane, tetraglycidyl-1,3-bisaminomethylcyclohexane and other diglycidylamino compounds;

Amino group-containing acid chlorides such as bis- (1-methylpropyl) carbamate chloride, 4-morpholincarbonyl chloride, 1-pyrrolidincarbonyl chloride, N, N-dimethylcarbamide acid chloride, N, N-diethylcarbamide acid chloride; 1 , 3-Bis- (Glysidyloxypropyl) -Tetramethyldisiloxane, (3-Glysidyloxypropyl) -Pentamethyldisiloxane and other epoxy group-containing silane compounds;

(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- (methyldisilyl) 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) ) A (thio) benzophenone compound having an amino group and / or a substituted amino group such as benzophenone, N, N, N', N'-bis- (tetraethylamino) benzophenone; 4-N, N-dimethylaminobenzaldehyde, 4- A benzaldehyde compound having an amino group and / or a substituted amino group such as N, N-diphenylaminobenzaldehyde, 4-N, N-divinylaminobenzaldehyde; N-methyl-2-pyrrolidone, N-vinyl-2-pyrrolidone, N- N-substituted pyrrolidone such as phenyl-2-pyrrolidone, Nt-butyl-2-pyrrolidone, N-methyl-5-methyl-2-pyrrolidone N-methyl-2-piperidone, N-vinyl-2-piperidone, N N-substituted piperidones such as -phenyl-2-piperidone; N-methyl-ε-caprolactam, N-phenyl-ε-caprolactam, N-methyl-ω-laurilolactum, N-vinyl-ω-laurylolactum, N -N-substituted lactams such as methyl-β-propiolactam, N-phenyl-β-propiolactam; etc.

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-dimethylaminoacetophen, 4-N, N-diethylaminoacetophenone, 1,3-bis (diphenyl) Amino) -2-propanone, 1,7-bis (methylethylamino) -4-heptanone and the like can be mentioned. Of these, modified SBR modified with alkoxysilane is preferable.
The modification with the above compound (denaturing agent) can be carried out by a known method.

The amount of styrene in the SBR is preferably 5% by mass or more, more preferably 10% by mass or more, and preferably 40% by mass or less, more preferably 25% by mass or less. Within the above range, the effect of the present invention tends to be obtained better.
The amount of styrene can be measured by the method described in Examples described later.

The vinyl content of SBR is preferably 20% by mass or more, more preferably 40% by mass or more, and preferably 80% by mass or less, more preferably 60% by mass or less. Within the above range, the effect of the present invention tends to be obtained better.
The amount of vinyl (1,2-bonded butadiene unit amount) can be measured by the method described in Examples described later.

The weight average molecular weight (Mw) of SBR is preferably 100,000 or more, more preferably 150,000 or more, and preferably 1 million or less, more preferably 500,000 or less. Within the above range, the effect of the present invention tends to be obtained better.
Mw is based on the measured value by gel permeation chromatography (GPC) (GPC-8000 series manufactured by Tosoh Corporation, detector: differential refractometer, column: TSKGEL SUPERMULTIPORE HZ-M manufactured by Tosoh Corporation). Can be obtained by standard polystyrene conversion.

The average amount of styrene in SBR is preferably 10% by mass or more, more preferably 15% by mass or more, and preferably 30% by mass or less, more preferably 25% by mass or less. Within the above range, the effect of the present invention tends to be obtained better.
Here, the average amount of styrene of SBR is {Σ (content of each SBR × amount of styrene of each SBR)} / total content of all SBR. For example, when the rubber component is composed of 90% by mass of SBR (A) (40% by mass of styrene amount), 5% by mass of SBR (B) (25% by mass of styrene amount), and 5% by mass of BR, the average amount of styrene is 39. It is 21% by mass (= (90 × 40 + 5 × 25) / (90 + 5)).

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

The content of SBR in 100% by mass of the rubber component may be 40 to 80% by mass, but is preferably 50% by mass or more, and preferably 70% by mass or less. Within the above range, the effect of the present invention tends to be obtained better.

The rubber composition contains BR as a rubber component.
The BR is not particularly limited, and BR having a high cis content, BR containing syndiotactic polybutadiene crystals, and the like can be used. The BR may be either a non-modified BR or a modified BR, and examples of the modified BR include a modified BR into which the above-mentioned functional group has been introduced. These may be used alone or in combination of two or more. In particular, the cis content of BR is preferably 90% by mass or more (preferably 95% by mass or more) because the wear resistance is improved. The cis content can be measured by infrared absorption spectrum analysis.

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

The content of BR in 100% by mass of the rubber component may be 10 to 30% by mass, but is preferably 15% by mass or more, and preferably 25% by mass or less. Within the above range, the effect of the present invention tends to be obtained better.

The rubber composition contains isoprene-based rubber as a rubber component.
Examples of the isoprene-based rubber include natural rubber (NR), isoprene rubber (IR), modified NR, modified NR, modified IR and the like. As the NR, for example, SIR20, RSS # 3, TSR20 and the like, which are common in the tire industry, can be used. The IR is not particularly limited, and for example, an IR 2200 or the like, which is common in the tire industry, can be used. Modified NR includes deproteinized natural rubber (DPNR), high-purity natural rubber (UPNR), etc., and modified NR includes epoxidized natural rubber (ENR), hydrogenated natural rubber (HNR), grafted natural rubber, etc. Examples of the modified IR include epoxidized isoprene rubber, hydrogenated isoprene rubber, grafted isoprene rubber and the like. These may be used alone or in combination of two or more.

The content of the isoprene-based rubber in 100% by mass of the rubber component may be 10 to 30% by mass, but is preferably 15% by mass or more, and preferably 25% by mass or less. Within the above range, the effect of the present invention tends to be obtained better.

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

The rubber composition contains silica.
Examples of silica include dry silica (silicic anhydride) and wet silica (hydrous silicic acid), but wet silica is preferable because it has a large amount of silanol groups. These may be used alone or in combination of two or more.

The nitrogen adsorption specific surface area (N ₂ SA) of silica is preferably 150 m ² / g or more, more preferably 200 m ² / g or more, still more preferably 220 m ² / g or more, and preferably 300 m ² / g or less. , More preferably 260 m ² / g or less. Within the above range, the effect of the present invention tends to be obtained better.
The nitrogen adsorption specific surface area of silica is a value measured by the BET method according to ASTM D3037-81.

As the silica, for example, products such as Degussa, Rhodia, Tosoh Silica Co., Ltd., Solvay Japan Co., Ltd., Tokuyama Corporation can be used.

The content of silica with respect to 100 parts by mass of the rubber component may be 70 parts by mass or more, preferably 80 parts by mass or more, more preferably 100 parts by mass or more, and preferably 150 parts by mass or less, more preferably. Is 130 parts by mass or less, more preferably 120 parts by mass or less. Within the above range, the effect of the present invention tends to be obtained better.

The rubber composition preferably contains a silane coupling agent together with silica. Thereby, the effect of the present invention tends to be obtained better.
The silane coupling agent is not particularly limited, and for example, bis (3-triethoxysilylpropyl) tetrasulfide, bis (2-triethoxysilylethyl) tetrasulfide, bis (4-triethoxysilylbutyl) tetrasulfide, and the like. 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-trimethoxysilylethyl) ) Disulfide, bis (4-trimethoxysilylbutyl) disulfide, 3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyltetrasulfide, 2-triethoxysilylethyl-N, N-dimethylthiocarbamoyltetrasulfide, 3- Sulfide type such as triethoxysilylpropyl methacrylate monosulfide, mercapto type such as 3-mercaptopropyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, vinyl type such as vinyltriethoxysilane and vinyltrimethoxysilane, 3-aminopropyl Amino-based such as triethoxysilane and 3-aminopropyltrimethoxysilane, glycidoxy-based such as γ-glycidoxypropyltriethoxysilane and γ-glycidoxypropyltrimethoxysilane, 3-nitropropyltrimethoxysilane, 3- Examples thereof include nitro type such as nitropropyltriethoxysilane, chloro type such as 3-chloropropyltrimethoxysilane and 3-chloropropyltriethoxysilane. These may be used alone or in combination of two or more. Among them, a sulfide type and a mercapto type are preferable, and a mercapto type is more preferable, because the effect of the present invention can be obtained more satisfactorily.

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

（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Ｒ^１００１、Ｒ^１００２、水素原子又は－［Ｏ（Ｒ^１００９Ｏ）_ｊ］_０．５－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、ｘは０以上の整数、ｙは１以上の整数である。Ｒ^１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^２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^１とＲ^２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) and a binding unit A represented by the following formula (I) and a binding unit B represented by the following formula (II) are used. Included silane coupling agents include.

(In the formula, R ¹⁰⁰¹ is -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 the OSiR ¹⁰⁰⁶ R ¹⁰⁰⁷ ) _h (OSiR ¹⁰⁰⁶ R ¹⁰⁰⁷ R ¹⁰⁰⁸ ) may be the same or different, each having a hydrogen atom or 1 to 18 carbon atoms. It is a monovalent hydrocarbon group, h has an average value of 1 to 4), R ¹⁰⁰² is R ¹⁰⁰¹ , a hydrogen atom or a monovalent hydrocarbon group having 1 to 18 carbon atoms, and R ¹⁰⁰³ is R. ¹⁰⁰¹ , R ¹⁰⁰² , hydrogen atom or-[O (R ¹⁰⁰⁹ O) _j ] _0.5 -group (R ¹⁰⁰⁹ is an alkylene group having 1 to 18 carbon atoms, j is an integer of 1 to 4), R ¹⁰⁰⁴ . Is a divalent hydrocarbon group having 1 to 18 carbon atoms, ^R1005 is a monovalent hydrocarbon group having 1 to 18 carbon atoms, and x, y and z are x + y + 2z = 3, 0≤x≤3,0. It is a number that satisfies the relationship of ≦ y ≦ 2 and 0 ≦ z ≦ 1.)

(In the equation, x is an integer of 0 or more, y is an integer of 1 or more. R ¹ is a hydrogen, halogen, branched or unbranched alkyl group having 1 to 30 carbon atoms, or 2 to 2 branched or unbranched carbon atoms. 30 alkenyl groups, branched or unbranched alkynyl groups having 2 to 30 carbon atoms, or hydrogens at the ends of the alkyl groups substituted with hydroxyl or carboxyl groups. R ² has branched or unbranched carbon atoms. It represents an alkylene group of 1 to 30, 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. A ring structure is formed by R ¹ and R ² . May be.)

In formula (S1), R ¹⁰⁰⁵ , R ¹⁰⁰⁶ , R ¹⁰⁰⁷ and R ¹⁰⁰⁸ are independently derived from a linear, cyclic or branched alkyl group having 1 to 18 carbon atoms, an alkenyl group, an aryl group and an aralkyl group. It is preferable that it is 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 a linear, cyclic or branched alkyl group, an alkenyl group, an aryl group and an aralkyl group. It is preferably a group. R ¹⁰⁰⁹ is preferably a linear, cyclic or branched alkylene group, and particularly preferably linear. ^R1004 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, and an arylene having 6 to 18 carbon atoms. Examples thereof include a group and an aralkylene group having 7 to 18 carbon atoms. The alkylene group and the alkenylene group may be linear or branched, and the cycloalkylene group, the cycloalkylalkylene group, the arylene group and the aralkylene group have a functional group such as a lower alkyl group on the ring. You may be doing it. As the 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 and a hexamethylene group is particularly preferable.

Specific examples of R ¹⁰⁰² , R ¹⁰⁰⁵ , R ¹⁰⁰⁶ , R ¹⁰⁰⁷ and R ¹⁰⁰⁸ in the formula (S1) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group and a 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 Examples thereof include a hexenyl group, a phenyl group, a trill group, a xsilyl group, a naphthyl group, a benzyl group, a phenethyl group and a naphthylmethyl group.
Examples of R ¹⁰⁰⁹ in the formula (S1) include a methylene group, an ethylene group, an n-propylene group, an n-butylene group, a hexylene group and the like as the linear alkylene group, and examples of the branched alkylene group include a branched alkylene group. Examples thereof include an isopropylene group, an isobutylene group and a 2-methylpropylene group.

Specific examples of the silane coupling agent represented by the formula (S1) include 3-hexanoylthiopropyltriethoxysilane, 3-octanoylthiopropyltriethoxysilane, 3-decanoylthiopropyltriethoxysilane, and 3-. Lauroylthiopropyltriethoxysilane, 2-hexanoylthioethyltriethoxysilane, 2-octanoylthioethyltriethoxysilane, 2-decanoylthioethyltriethoxysilane, 2-lauroylthioethyltriethoxysilane, 3-hexanoi Luciopropyltrimethoxysilane, 3-octanoylthiopropyltrimethoxysilane, 3-decanoylthiopropyltrimethoxysilane, 3-lauroylthiopropyltrimethoxysilane, 2-hexanoylthioethyltrimethoxysilane, 2-octanoylthio Examples thereof include ethyltrimethoxysilane, 2-decanoylthioethyltrimethoxysilane, and 2-lauroylthioethyltrimethoxysilane. 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 binding unit A represented by the formula (I) and the binding unit B represented by the following formula (II), the content of the binding unit A is preferably 30 mol% or more, more preferably 50. It is mol% or more, preferably 99 mol% or less, and more preferably 90 mol% or less. 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, and more preferably 65 mol% or less. More preferably, it is 55 mol% or less. 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 binding units A and B is an amount including the case where the binding units A and B are located at the end of the silane coupling agent. The form in which the binding units A and B are located at the ends of the silane coupling agent is not particularly limited, and may form a unit corresponding to the formulas (I) and (II) representing the binding units A and B. ..

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

Regarding ^R2 in the formulas (I) and (II), examples of the branched or non-branched alkylene group having 1 to 30 carbon atoms include an ethylene group and a propylene group. Examples of the branched or non-branched alkenylene group having 2 to 30 carbon atoms include a vinylene group and a 1-propenylene group. Examples of the branched or non-branched alkynylene group having 2 to 30 carbon atoms include an ethynylene group and a propynylene group.

In a silane coupling agent containing the binding unit A represented by the formula (I) and the binding unit B represented by the formula (II), the number of repetitions (x) of the binding unit A and the number of repetitions (y) of the binding unit B. The total number of repetitions (x + y) 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 effect of the present invention tends to be obtained better.

The rubber composition contains a liquid plasticizer.
The liquid plasticizer is a plasticizer that is liquid at 20 ° C., and examples thereof include oil, liquid rubber, and ester compounds. These may be used alone or in combination of two or more. Of these, oil is preferable.
The C5 resin described later is not included in the liquid plasticizer.

Examples of the oil include process oils, vegetable oils and fats, animal oils and fats and the like. Examples of the process oil include paraffin-based process oils, naphthen-based process oils, aromatic process oils and the like. In addition, as an environmental measure, a process oil having a low content of a polycyclic aromatic compound (PCA) compound (a low PCA content process oil) can also be mentioned. Low PCA content process oils include Treated Distillate Aromatic Extract (TDAE) oil, which is a re-extracted oil aromatic process oil, aroma substitute oil, which is a mixture of asphalt and naphthenic oil, and mild extraction solvents (mild extraction solvent). MES)), heavy naphthenic oil and the like can be mentioned. Vegetable oils and fats include 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 oil, sesame oil, olive oil, sunflower. Examples thereof include oil, palm kernel oil, camellia oil, jojoba oil, macadamia nut oil, safflower oil, and tung oil. Examples of animal fats and oils include oleyl alcohol, fish oil, and beef tallow. These may be used alone or in combination of two or more. Of these, process oils are preferred, low PCA content process oils are more preferred, and TDAE oils are even more preferred.

The content of the liquid plasticizer may be adjusted in the range of 1 to 50 parts by mass and within the range satisfying the formula (A) with respect to 100 parts by mass of the rubber component, but is preferably 5 parts by mass or more, more preferably. Is 15 parts by mass or more, more preferably 25 parts by mass or more, preferably 40 parts by mass or less, and more preferably 30 parts by mass or less. Within the above range, the effect of the present invention tends to be obtained better.

The rubber composition contains a C5 resin.
The C5 resin is a solid or liquid polymer at 20 ° C. using a C5 fraction as a constituent monomer, and examples thereof include a polymer polymerized with the C5 fraction as a main component (50% by mass or more). Specifically, C5 distillates (olefin hydrocarbons such as 1-pentene, 2-pentene, 2-methyl-1-butene, 2-methyl-1,3-butadiene, 1,2-pentadiene, 1,3 -A homopolymer obtained by independently polymerizing a diolefin hydrocarbon such as pentadiene), a copolymer obtained by copolymerizing two or more kinds of C5 distillates, a C5 distillate, and other copolymers capable of copolymerizing with the C5 distillate. A copolymer with a monomer is also mentioned.

Examples of other monomers include C9 fractions such as vinyltoluene, indene, and methyl indene. These may be used alone or in combination of two or more.

The C5 resin is preferably a copolymer of a C5 fraction and another monomer, and a copolymer of the C5 fraction and the C9 fraction is preferable because the effect of the present invention tends to be obtained better. Coalescence (C5 / C9 resin) is more preferred.

The softening point of the C5 resin is preferably 30 ° C. or higher, more preferably 60 ° C. or higher, and preferably 120 ° C. or lower, more preferably 94 ° C. or lower. Within the above range, the effect of the present invention tends to be obtained better.
In the present invention, the softening point of the resin is the temperature at which the ball drops when the softening point defined in JIS K 62201: 2001 is measured by a ring-ball type softening point measuring device.

The number average molecular weight (Mn) of the C5 resin is preferably 500 or more, more preferably 1000 or more, and preferably 2000 or less, more preferably 1200 or less. Within the above range, the effect of the present invention tends to be obtained better.
Mn can be obtained by the same method as Mw.

The weight average molecular weight (Mw) of the C5 resin is preferably 1000 or more, more preferably 2000 or more, and preferably 5000 or less, more preferably 3900 or less. Within the above range, the effect of the present invention tends to be obtained better.

The content of the C5 resin may be adjusted in the range of 1 to 50 parts by mass with respect to 100 parts by mass of the rubber component and in the range satisfying the formula (A), but is preferably 2 parts by mass or more, more preferably. Is 6 parts by mass or more, more preferably 8 parts by mass or more, preferably 30 parts by mass or less, and more preferably 20 parts by mass or less. Within the above range, the effect of the present invention tends to be obtained better.

The rubber composition may contain other resins in addition to the C5 resin. The other resins are not particularly limited as long as they are widely used in the tire industry, and are rosin-based resins other than rosin ester resins, kumaron indene resins, terpene-based resins, pt-butylphenol acetylene resins, and acrylic-based resins. Examples include resin. These may be used alone or in combination of two or more.

Commercial products of C5 resin and other resins include, for example, Maruzen Petrochemical Co., Ltd., Sumitomo Bakelite Co., Ltd., Yasuhara Chemical Co., Ltd., Toso Co., Ltd., Rutgers Chemicals Co., Ltd., BASF Co., Ltd., Arizona Chemical Co., Ltd., Japan. Products such as Petrochemical Co., Ltd., Nippon Catalyst Co., Ltd., JX Energy Co., Ltd., Arakawa Chemical Industry Co., Ltd., and Taoka Chemical Industry Co., Ltd. can be used.

In the rubber composition, the content of the liquid plasticizer and the content of the C5 resin satisfy the following formula (A).
(A) α1 / α2 ≧ 1
α1: Content of liquid plasticizer with respect to 100 parts by mass of rubber component [parts by mass]
α2: Content of C5 resin with respect to 100 parts by mass of rubber component [parts by mass]

In the formula (A), α1 / α2 may be 1 or more, but preferably 1.5 or more, preferably 18 or less, more preferably 14 or less, and further preferably 4 or less. Within the above range, the effect of the present invention tends to be obtained better.

The rubber composition preferably contains carbon black. Thereby, the effect of the present invention tends to be obtained better.
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 carbon black cetyltrimethylammonium bromide (CTAB) is preferably 150 m ² / g or more, more preferably 170 m ² / g or more, still more preferably 180 m ² / g or more, and preferably 250 m ² / g or more. Below, it is more preferably 200 m ² / g or less. Within the above range, the effect of the present invention tends to be obtained better.
The CTAB specific surface area of carbon black is a value measured in accordance with JIS K6217-3: 2001.

The nitrogen adsorption specific surface area (N ₂ SA) of carbon black is preferably 160 m ² / g or more, more preferably 177 m ² / g or more, and preferably 250 m ² / g or less, more preferably 200 m ² / g. It is as follows. Within the above range, the effect of the present invention tends to be obtained better.
The carbon black N ₂ SA is a value measured in accordance with JIS K6217-2: 2001.

The iodine adsorption amount (IA) of carbon black is preferably 170 mg / g or more, more preferably 188 mg / g or more, and preferably 250 mg / g or less, more preferably 200 mg / g or less. Within the above range, the effect of the present invention tends to be obtained better.
The IA of carbon black is a value measured in accordance with JIS K6217-1: 2008.

As carbon black, for example, products of Asahi Carbon Co., Ltd., Cabot Japan Co., Ltd., Tokai Carbon Co., Ltd., Mitsubishi Chemical Corporation, Lion Corporation, Shin Nikka Carbon Co., Ltd., Columbia Carbon Co., Ltd., 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 30 parts by mass or less, based on 100 parts by mass of the rubber component. It is preferably 20 parts by mass or less. Within the above range, the effect of the present invention can be obtained more preferably.

When carbon black is contained, it is preferable that the content of silica and the content of carbon black in the rubber composition satisfy the following formula (B). Thereby, the effect of the present invention tends to be obtained better.
(B) β1 / β2 ≦ 0.4
β1: Content of carbon black with respect to 100 parts by mass of rubber component [parts by mass]
β2: Silica content with respect to 100 parts by mass of rubber component [parts by mass]

In the formula (B), β1 / β2 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. It is 0.04 or more. Within the above range, the effect of the present invention tends to be obtained better.

The rubber composition may contain wax.
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 Shinko Kagaku Kogyo Co., Ltd., Nippon Seiro Co., Ltd., and Seiko Kagaku 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 2 parts by mass or more, and preferably 20 parts by mass or less, more preferably 20 parts by mass or more, based on 100 parts by mass of the rubber component. It is 10 parts by mass or less. Within the above range, the effect of the present invention tends to be obtained better.

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

As the anti-aging agent, for example, products of Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., Ouchi Shinko Chemical Industry Co., Ltd., Flexis Co., Ltd. and the like 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 3.5 parts by mass or more, and preferably 10 parts by mass with respect to 100 parts by mass of the rubber component. Parts or less, more preferably 8 parts by mass or less. Within the above range, the effect of the present invention tends to be obtained better.

The rubber composition may contain stearic acid.
As the stearic acid, conventionally known ones can be used, and for example, products such as NOF Corporation, NOF Corporation, Kao Corporation, Wako Pure Chemical Industries, Ltd., and Chiba Fatty Acid Co., Ltd. can be used.

When stearic acid is contained, the content of stearic acid is preferably 1 part by mass or more, more preferably 2.5 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 5 parts by mass or less. Within the above range, the effect of the present invention tends to be obtained better.

The rubber composition may contain zinc oxide.
As the zinc oxide, conventionally known products can be used, for example, products of Mitsui Metal Mining Co., Ltd., Toho Zinc Co., Ltd., HakusuiTech Co., Ltd., Shodo Chemical Industry Co., Ltd., Sakai Chemical Industry Co., Ltd., etc. Can be used.

When zinc oxide is contained, the content of zinc oxide 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. It is preferably 5 parts by mass or less. Within the above range, the effect of the present invention tends to be obtained better.

The rubber composition may contain sulfur.
Examples of sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, highly dispersible sulfur, and soluble sulfur, which are 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 Industry Co., Ltd., Karuizawa Sulfur Co., Ltd., Shikoku Chemicals Corporation, Flexis Co., Ltd., Nippon Inui Kogyo Co., Ltd., Hosoi Chemical Industry Co., Ltd. can be used.

When sulfur is contained, the sulfur content 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 5 parts by mass or less. Within the above range, the effect of the present invention tends to be obtained better.

The rubber composition may contain a vulcanization accelerator.
Examples of the vulcanization accelerator include thiazole-based vulcanization accelerators such as 2-mercaptobenzothiazole, di-2-benzothiazolyl disulfide, and N-cyclohexyl-2-benzothiadylsulfenamide; tetramethylthiuram disulfide (TMTD). ), Tetrabenzyltiuram disulfide (TBzTD), tetrakis (2-ethylhexyl) thiuram disulfide (TOT-N) and other thiuram-based vulcanization accelerators; N-cyclohexyl-2-benzothiazolesulfenamide, Nt-butyl- 2-benzothiazolyl sulfenamide, N-oxyethylene-2-benzothiazolesulfenamide, N-oxyethylene-2-benzothiazolesulfenamide, N, N'-diisopropyl-2-benzothiazolesulfenamide, etc. Sulfenamide-based vulcanization accelerator; guanidine-based vulcanization accelerators such as diphenylguanidine, dioltotrilguanidine, orthotrilviguanidine can be mentioned. These may be used alone or in combination of two or more. Of these, sulfenamide-based vulcanization accelerators and guanidine-based vulcanization accelerators are preferable because the effects of the present invention can be obtained more preferably.

When the vulcanization accelerator is contained, the content of the vulcanization accelerator is preferably 1 part by mass or more, more preferably 3.5 parts by mass or more, and preferably 3.5 parts by mass or more with respect to 100 parts by mass of the rubber component. It is 10 parts by mass or less, more preferably 8 parts by mass or less. Within the above range, the effect of the present invention tends to be obtained better.

In addition to the above components, the rubber composition contains additives commonly 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 kneading each component using a rubber kneading device such as an open roll or a Banbury mixer, and then vulcanizing.

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

The above rubber composition is preferably used for treads (cap treads), but for members other than treads, such as sidewalls, base treads, under treads, clinch apex, bead apex, breaker cushion rubber, and carcass cord coating. It may be used for rubber, insulation, chafer, inner liner, etc., and a side reinforcing layer of a run-flat tire.

The pneumatic tire of the present invention is manufactured by a usual method using the above rubber composition.
That is, the rubber composition is extruded according to the shape of each tire member of the tread at the unvulcanized stage, and is molded together with other tire members by a normal method on a tire molding machine. Form a vulcanized tire. A tire is obtained by heating and pressurizing this unvulcanized tire in a vulcanizer.

As for the pneumatic 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 with reference to Examples, but the present invention is not limited thereto.
The various chemicals used in the examples will be described below.
NR: TSR20
SBR1: Modified SBR synthesized in Production Example 1 below (styrene amount: 10% by mass, vinyl amount: 40% by mass, Mw: 200,000)
SBR2: Modified SBR synthesized in Production Example 2 below (styrene amount: 25% by mass, vinyl amount: 60% by mass, Mw: 150,000)
BR: BR730 manufactured by JSR Corporation
Carbon black: Prototype (CTAB: 180m ² / g, N ₂ SA: 177m ² / g, IA: 188mg / g)
Silica 1: Ultrasil 9000GR manufactured by Evonik Degussa (N ₂ SA: 240m ² / g)
Silica 2: Ultrasil VN3 manufactured by Evonik Degussa (N ₂ SA: 167m ² / g)
Silane coupling agent 1: NXT-Z45 manufactured by Momentive (copolymer of binding unit A and binding unit B (binding unit A: 55 mol%, binding unit B: 45 mol%))
Silane coupling agent 2: Si266 (bis (3-triethoxysilylpropyl) disulfide) manufactured by Evonik Degussa.
Oil: VIVATEC500 (TDAE oil) manufactured by H & R
C5 resin: Petrotac 100V manufactured by Tosoh Corporation (C5 / C9 resin, softening point: 94 ° C, Mw: 3900, Mn: 1200)
Wax: Ozo Ace 0355 manufactured by Nippon Seiro Co., Ltd.
Anti-aging agent 1: Nocrack 6C (N- (1,3-dimethylbutyl) -N'-phenyl-p-phenylenediamine) manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.
Anti-aging agent 2: Nocrack RD (Poly (2,2,4-trimethyl-1,2-dihydroquinoline)) manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.
Stearic acid: Stearic acid "Camellia" manufactured by NOF CORPORATION
Zinc oxide: Zinc oxide No. 1 manufactured by Mitsui Metal Mining Co., Ltd. Sulfur: Powdered sulfur vulcanization accelerator manufactured by Tsurumi Chemical Co., Ltd .1: Noxeller NS (N-tert-butyl) manufactured by Ouchi Shinko Chemical Industry Co., Ltd. -2-Benzothiazolylsulfenamide)
Vulcanization accelerator 2: Noxeller D (1,3-diphenylguanidine) manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.

(Manufacturing Example 1)
Under a nitrogen atmosphere, 3-dimethylaminopropyltrimethoxysilane was placed in a 100 ml volumetric flask, and anhydrous hexane was further added to prepare a terminal modifier.
N-Hexane, styrene, butadiene, and tetramethylethylenediamine were added to a pressure-resistant container sufficiently substituted with nitrogen, and the temperature was raised to 40 ° C. Next, after adding butyllithium, the temperature was raised to 50 ° C. and the mixture was stirred. Next, a silicon tetrachloride / hexane solution was added, and the mixture was stirred. Next, the above-mentioned terminal denaturing agent was added, and stirring was performed. After adding methanol in which 2,6-tert-butyl-p-cresol was dissolved in the reaction solution, the reaction solution was placed in a stainless steel container containing methanol to recover the aggregate. The obtained aggregate was dried under reduced pressure for 24 hours to obtain SBR1.

(Manufacturing Example 2)
Under a nitrogen atmosphere, 3-diethylaminopropyltrimethoxysilane was placed in a 100 ml volumetric flask, and anhydrous hexane was further added to prepare a terminal modifier.
N-Hexane, styrene, butadiene, and tetramethylethylenediamine were added to a pressure-resistant container sufficiently substituted with nitrogen, and the temperature was raised to 40 ° C. Next, after adding butyllithium, the temperature was raised to 50 ° C. and the mixture was stirred. Next, a silicon tetrachloride / hexane solution was added, and the mixture was stirred. Next, the above-mentioned terminal denaturing agent was added, and stirring was performed. After adding methanol in which 2,6-tert-butyl-p-cresol was dissolved in the reaction solution, the reaction solution was placed in a stainless steel container containing methanol to recover the aggregate. The obtained aggregate was dried under reduced pressure for 24 hours to obtain SBR2.

<Analysis of SBR>
The structure identification of SBR (measurement of styrene amount and vinyl amount) was performed using a JNM-ECA series device manufactured by JEOL Ltd. The measurement was carried out by dissolving 0.1 g of the polymer in 15 ml of toluene, slowly pouring it into 30 ml of methanol to reprecipitate, and drying under reduced pressure.

<Examples and comparative examples>
According to the compounding contents shown in Tables 1 and 2, using a 1.7 L Banbury mixer manufactured by Kobe Steel, Ltd., materials other than sulfur and vulcanization accelerator are kneaded under the condition of 150 ° C. for 5 minutes and mixed. I got a paste. Next, sulfur and a vulcanization accelerator were added to the obtained kneaded product, and the mixture was kneaded under the condition of 80 ° C. for 5 minutes 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, which is press-vulcanized for 10 minutes under the condition of 170 ° C. to obtain a test tire (test tire). Size: 195 / 65R15) was manufactured. The following evaluations were performed using the obtained test tires, and the results are shown in Tables 1 and 2.

(Dry grip performance)
Each test tire was attached to all wheels of the vehicle (domestic FF2000cc), and the actual vehicle was run for 10 laps on a test course on a dry asphalt road surface. The test site was the Okayama test course of Sumitomo Rubber Industries, Ltd., and the temperature was 20 to 25 ° C. Then, the test driver evaluated the stability of the control during steering at that time, and displayed it as an index when the standard formulation (Table 1 is Comparative Example 1 and Table 2 is Example 8) was set to 100 (dry grip performance). index). The larger the index, the better the grip performance on the dry road surface.

(Wet grip performance)
Each test tire was attached to all wheels of the vehicle (domestic FF2000cc), and the braking distance from the initial speed of 100 km / h was obtained on a wet asphalt road surface. It was displayed as an index when 8) was set to 100 (wet grip performance index). The larger the index, the shorter the braking distance and the better the wet grip performance.

(Abrasion resistance)
Each test tire is attached to all wheels of the vehicle (domestic FF2000cc), the groove depth of the tire tread after a mileage of 8000 km is measured, and the mileage when the tire groove depth is reduced by 1 mm is calculated and used as a reference. It is expressed as an index when the composition (Table 1 is Comparative Example 1 and Table 2 is Example 8) is set to 100 (wear resistance index). The larger the index, the longer the mileage when the tire groove depth is reduced by 1 mm, and the better the wear resistance.

From Tables 1 and 2, examples in which a predetermined amount of styrene-butadiene rubber, butadiene rubber, isoprene-based rubber, silica, liquid plasticizer, and C5-based resin are contained and the formula (A) is satisfied are dry grip performance and wet grip performance. And the wear resistance was significantly improved in a well-balanced manner.

Claims (8)

A rubber component having a styrene-butadiene rubber content of 40 to 80% by mass, a butadiene rubber content of 10 to 30% by mass, and an isoprene-based rubber content of 10 to 30% by mass.
Silica having a content of 80 parts by mass or more with respect to 100 parts by mass of the rubber component and
A liquid plasticizer having a content of 1 to 50 parts by mass with respect to 100 parts by mass of the rubber component.
It contains a C5 resin having a content of 1 to 50 parts by mass with respect to 100 parts by mass of the rubber component.
The amount of styrene in the styrene-butadiene rubber is 25% by mass or less, and the amount of styrene is 25% by mass or less.
A rubber composition for a tire satisfying the following formula (A) .
(A) α1 / α2 ≧ 1
α1: Content of liquid plasticizer with respect to 100 parts by mass of rubber component [parts by mass]
α2: Content of C5 resin with respect to 100 parts by mass of rubber component [parts by mass]
A rubber composition for a tire that satisfies at least one of the following requirements (i) to (iii).
(I) The content of the silica with respect to 100 parts by mass of the rubber component is 100 to 130 parts by mass.
(Ii) The content of the liquid plasticizer with respect to 100 parts by mass of the rubber component is 25 to 50 parts by mass.
(Iii) The softening point of the C5 resin is 30 ° C. or higher. A rubber component having a styrene-butadiene rubber content of 40 to 80% by mass, a butadiene rubber content of 10 to 30% by mass, and an isoprene-based rubber content of 10 to 30% by mass.
Silica having a content of 80 parts by mass or more with respect to 100 parts by mass of the rubber component and
A liquid plasticizer having a content of 1 to 50 parts by mass with respect to 100 parts by mass of the rubber component.
It contains a C5 resin having a content of 1 to 50 parts by mass with respect to 100 parts by mass of the rubber component.
A rubber composition for a tire satisfying the following formula (A) .
(A) α1 / α2 ≧ 1.5
α1: Content of liquid plasticizer with respect to 100 parts by mass of rubber component [parts by mass]
α2: Content of C5 resin with respect to 100 parts by mass of rubber component [parts by mass]
A rubber composition for a tire that satisfies at least one of the following requirements (i) to (iii).
(I) The content of the silica with respect to 100 parts by mass of the rubber component is 100 to 130 parts by mass.
(Ii) The content of the liquid plasticizer with respect to 100 parts by mass of the rubber component is 25 to 50 parts by mass.
(Iii) The softening point of the C5 resin is 30 ° C. or higher. The rubber composition for a tire according to claim 1 or 2, which contains carbon black having a specific surface area of 150 m ² / g or more. Contains carbon black,
The rubber composition for a tire according to any one of claims 1 to 3, which satisfies the following formula (B).
(B) β1 / β2 ≦ 0.1
β1: Content of carbon black with respect to 100 parts by mass of rubber component [parts by mass]
β2: Silica content with respect to 100 parts by mass of rubber component [parts by mass] The rubber composition for a tire according to any one of claims 1 to 4, 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 , which contains a mercapto-based silane coupling agent. The rubber composition for a tire according to any one of claims 1 to 6 , wherein the C5 resin contains a copolymer of a C5 fraction and a C9 fraction. A pneumatic tire produced by using the rubber composition according to any one of claims 1 to 7 .