JP2021195440A - Rubber composition for tire and tire - Google Patents

Abstract

To provide a rubber composition for a tire and a tire capable of improving wet steering stability.SOLUTION: A rubber composition for a tire includes a rubber constituent, carbon black and silica, and satisfies the following expressions (A) to (D): (A) a total styrene content in the rubber constituent≥20 mass%; (B) a content of the silica>the total styrene content in the rubber constituent; (C) a content of the carbon black/the content of the silica≥1.5; and (D) an acetone extraction amount≤35 mass%.SELECTED DRAWING: None

Description

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

Conventionally, various methods for improving steering stability on wet road surfaces (wet steering stability) have been studied. For example, Patent Document 1 discloses a method of blending aluminum hydroxide and a dithiophosphate-based compound. There is. However, in recent years, further improvement in wet steering stability has been required.

Japanese Unexamined Patent Publication No. 11-334310

An object of the present invention is to provide a rubber composition for a tire and a tire capable of solving the above-mentioned problems and improving wet steering stability.

The present invention relates to a rubber composition for a tire containing a rubber component, carbon black and silica and satisfying the following formulas (A) to (D).
(A) Total amount of styrene in rubber component ≧ 20% by mass
(B) Silica content> Total styrene content in rubber component (C) Carbon black content / Silica content ≧ 1.5
(D) Acetone extraction amount ≤ 35% by mass

The rubber composition preferably contains an aromatic resin.

The rubber composition preferably contains a liquid polymer.

The specific surface area of the carbon black cetyltrimethylammonium bromide ^{is preferably 110 m 2} / g or more.

The average particle size of the silica is preferably 16 nm or less.

The rubber composition preferably contains a terpene-based resin.

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

The rubber composition preferably contains a dibenzylamine compound.

The present invention also relates to a tire having a tread using the rubber composition.

Since the present invention is a rubber composition for a tire containing a rubber component, carbon black and silica and satisfying the formulas (A) to (D), excellent wet steering stability can be obtained.

The rubber composition for a tire of the present invention contains a rubber component, carbon black and silica, and satisfies the formulas (A) to (D).

The reason why the above-mentioned effect can be obtained with the above rubber composition is presumed as follows.
Wet steering stability is considered to have a high correlation with rubber hardness, but in the above rubber composition, the total amount of styrene in the rubber component, the amount of carbon black, and the amount of silica are within a predetermined range. By the interaction between carbon black and silica and the rubber component, carbon black and silica are uniformly distributed (dispersed) in the rubber component, and the rubber hardness becomes uniform. Further, when the amount of acetone extracted is within a predetermined range, the rubber hardness is suitable for a wet road surface. It is considered that the wet steering stability is remarkably improved by making the rubber hardness uniform and appropriate in this way.

The rubber composition contains a rubber component.
Here, the rubber component is a component that contributes to crosslinking, and generally has a weight average molecular weight (Mw) of 10,000 or more.

The weight average molecular weight of the rubber component is preferably 50,000 or more, more preferably 150,000 or more, still more preferably 200,000 or more, and preferably 2 million or less, more preferably 1.7 million or less, still more preferably 1.4 million. It is as follows. Within the above range, the effect tends to be better obtained.

In the present specification, the weight average molecular weight (Mw) is a gel permeation chromatograph (GPC) (GPC-8000 series manufactured by Tosoh Corporation, detector: differential refractometer, column: TSKGEL manufactured by Tosoh Corporation. It can be obtained by standard polystyrene conversion based on the measured value by SUPERMULTIPORE HZ-M).

In the rubber composition, the total amount of styrene in the rubber component satisfies the following formula (A).
(A) Total amount of styrene in rubber component ≧ 20% by mass
In the formula (A), the total amount of styrene in the rubber component is the content (unit: mass%) in 100% by mass of the rubber component.

In the formula (A), the total amount of styrene in the rubber component is preferably 28% by mass or more, more preferably 32% by mass or more, further preferably 35% by mass or more, and preferably 50% by mass or less. It is preferably 45% by mass or less, more preferably 40% by mass or less. Within the above range, the effect tends to be better obtained.

Here, the total amount of styrene in the rubber component can be calculated by Σ (content of each rubber component × amount of styrene in each rubber component / 100). For example, when the amount of styrene: 40% by mass of SBR is 85% by mass, the amount of styrene: SBR of 25% by mass is 5% by mass, and the amount of styrene: BR of 0% by mass is 10% by mass in 100% by mass of the rubber component. , The total amount of styrene in the rubber component is 35.25% by mass (= 85 × 40/100 + 5 × 25/100 + 10 × 0/100).

In the rubber composition, it is preferable that the total amount of vinyl in the rubber component satisfies the following formula (A').
(A') Total vinyl content in rubber component ≥ 15% by mass
In the formula (A'), the total amount of vinyl in the rubber component is the content (unit: mass%) in 100% by mass of the rubber component.

In the formula (A'), the total amount of vinyl in the rubber component is preferably 18% by mass or more, more preferably 21% by mass or more, further preferably 22% by mass or more, and preferably 40% by mass or less. It is more preferably 35% by mass or less, still more preferably 30% by mass or less. Within the above range, the effect tends to be better obtained.

Here, the total amount of vinyl in the rubber component can be calculated by Σ (content of each rubber component × amount of vinyl in each rubber component / 100). For example, when the SBR having a vinyl content of 30% by mass is 85% by mass, the SBR having a vinyl content of 20% by mass is 5% by mass, and the BR having a vinyl content of 10% by mass is 10% by mass in 100% by mass of the rubber component. The total amount of vinyl in the rubber component is 27.5% by mass (= 85 × 30/100 + 5 × 20/100 + 10 × 10/100).

In the rubber composition, it is preferable that the total amount of styrene and the total amount of vinyl in the rubber component satisfy the following formulas (A'') and (A''').
(A'') Total vinyl content in rubber component / total styrene amount in rubber component ≧ 0.4
(A'''') Total styrene amount in the rubber component ≧ Total vinyl amount in the rubber component In the formulas (A'') and (A''''), the total styrene amount and the total vinyl amount in the rubber component are , Content in 100% by mass of rubber component (unit: mass%).

In the formula (A''), the total amount of vinyl in the rubber component / the total amount of styrene in the rubber component is preferably 0.5 or more, more preferably 0.6 or more, and preferably 1.5 or less. , More preferably 1.3 or less, still more preferably 0.8 or less. Within the above range, the effect tends to be better obtained.

| Total styrene amount in rubber component-Total vinyl amount in rubber component | is preferably 6 or more, more preferably 10 or more, still more preferably 13 or more, and preferably 20 or less, more preferably 18 or less. , More preferably 15 or less. Within the above range, the effect tends to be better obtained.

The amount of styrene and the amount of vinyl in each rubber component can be measured by a nuclear magnetic resonance (NMR) method.
Further, the total amount of styrene and the total amount of vinyl in the rubber component are calculated according to the above-mentioned calculation formula in the examples of the present specification. For example, a pyrolysis gas chromatograph mass spectrometer (Py-GC / It may be analyzed from the tire by MS) or the like.

The rubber components contained in the rubber composition include isoprene-based rubber, styrene-butadiene rubber (SBR), butadiene rubber (BR), acrylonitrile-butadiene rubber (NBR), chloroprene rubber (CR), butyl rubber (IIR), and styrene-isoprene. -Diene rubber such as butadiene copolymer rubber (SIBR) can be mentioned. These may be used alone or in combination of two or more. Of these, SBR and BR are preferable.

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. Examples of commercially available products include products such as Sumitomo Chemical Co., Ltd., JSR Corporation, Asahi Kasei Co., Ltd., and Zeon Corporation.

The amount of styrene in the SBR is preferably 10% by mass or more, more preferably 20% by mass or more, further preferably 30% by mass or more, and preferably 60% by mass or less, more preferably 50% by mass or less, still more preferably. Is 40% by mass or less. Within the above range, the effect tends to be better obtained.

The vinyl content of SBR is preferably 5% by mass or more, more preferably 15% by mass or more, further preferably 24% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably. Is 32% by mass or less. Within the above range, the effect tends to be better obtained.

The above-mentioned styrene amount and vinyl amount of SBR mean the styrene amount and vinyl amount of the SBR when there is only one type of SBR, and the average styrene amount and average vinyl amount when there are a plurality of types.
The average amount of styrene in SBR can be calculated by {Σ (content of each SBR x amount of styrene in each SBR)} / total content of all SBR, for example, styrene amount: 40% by mass in 100% by mass of rubber component. When the SBR is 85% by mass and the amount of styrene: 25% by mass, the average amount of styrene of SBR is 39.2% by mass (= (85 × 40 + 5 × 25) / (85 + 5)). ..
Similarly, the average vinyl content of SBR can be calculated by {Σ (content of each SBR × vinyl content of each SBR)} / total content of all SBR, for example, vinyl content in 100% by mass of rubber component: 30. When the mass% of SBR is 85% by mass and the amount of vinyl: 20% by mass of SBR is 5% by mass, the average amount of vinyl in SBR is 29.4% by mass (= (85 × 30 + 5 × 20) / (85 + 5)). ).

The content of SBR in 100% by mass of the rubber component is preferably 50% by mass or more, more preferably 70% by mass or more, further preferably 80% by mass or more, and preferably 95% by mass or less, more preferably 95% by mass or less. It is 90% by mass or less. Within the above range, the effect tends to be better obtained.

The BR is not particularly limited, and BR having a high cis content, BR having a low cis content, BR containing syndiotactic polybutadiene crystals, and the like can be used. Examples of commercially available products include products such as Ube Industries, Ltd., JSR Corporation, Asahi Kasei Corporation, and Nippon Zeon Corporation.

The cis amount (cis content) of BR is preferably 80% by mass or more, more preferably 90% by mass or more, further preferably 95% by mass or more, and preferably 99% by mass or less, more preferably 97% by mass. It is as follows. Within the above range, the effect tends to be better obtained.
The amount of BR cis can be measured by infrared absorption spectrum analysis.

The above-mentioned cis amount of BR means the cis amount of the BR when there is one kind of BR, and means the average cis amount when there are a plurality of kinds of BR.
The average cis amount of BR can be calculated by {Σ (content of each BR × cis amount of each BR)} / total content of all BR, for example, cis amount: 90% by mass in 100% by mass of rubber component. When BR is 20% by mass and cis amount: 40% by mass, the average cis amount of BR is 73.3% by mass (= (20 × 90 + 10 × 40) / (20 + 10)). ..

The content of BR in 100% by mass of the rubber component is preferably 5% by mass or more, more preferably 10% by mass or more, and preferably 50% by mass or less, more preferably 30% by mass or less, still more preferably. It is 20% by mass or less. Within the above range, the effect tends to be better obtained.

The rubber component may be modified to introduce a functional group that interacts with a filler such as silica.
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.

Specific examples of the above-mentioned compound having a functional group (modifier) include 2-dimethylaminoethyltrimethoxysilane, 3-dimethylaminopropyltrimethoxysilane, 2-dimethylaminoethyltriethoxysilane, and 3-dimethylaminopropyltriethoxy. Examples thereof include silane, 2-diethylaminoethyltrimethoxysilane, 3-diethylaminopropyltrimethoxysilane, 2-diethylaminoethyltriethoxysilane, and 3-diethylaminopropyltriethoxysilane.

The rubber composition contains carbon black.
The carbon black is not particularly limited, and examples thereof include N134, N110, N220, N234, N219, N339, N330, N326, N351, N550, and N762. As commercial products, products such as 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. are used. can. These may be used alone or in combination of two or more.

Cetyl trimethyl ammonium bromide (CTAB) specific surface area of the carbon black, preferably 110m ² / g or more, more preferably 120 m ² / g or more, more preferably 130m ² / g or more, preferably 200 meters ² / g Below, it is more preferably 180 m ² / g or less, ^{still more preferably 160 m 2} / g or less. Within the above range, the effect tends to be better obtained.
The CTAB specific surface area of carbon black is a value measured in accordance with JIS K6217-3: 2001.

The content of carbon black is preferably 40 parts by mass or more, more preferably 55 parts by mass or more, still more preferably 65 parts by mass or more, and particularly preferably 70 parts by mass or more with respect to 100 parts by mass of the rubber component. It is preferably 120 parts by mass or less, more preferably 100 parts by mass or less, and further preferably 90 parts by mass or less. Within the above range, the effect tends to be better obtained.

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. As commercially available products, products such as EVONIK, Tosoh Silica Co., Ltd., Solvay Japan Co., Ltd., and Tokuyama Corporation can be used. These may be used alone or in combination of two or more.

The average particle size of silica is preferably 20 nm or less, more preferably 17 nm or less, further preferably 16 nm or less, particularly preferably 15 nm or less, and preferably 6 nm or more, more preferably 9 nm or more, still more preferably 12 nm or more. Is. Within the above range, the effect tends to be better obtained.

In the present specification, a transmission electron microscope (TEM) observation is used as a method for measuring the average particle size of silica. Specifically, the silica particles are photographed with a transmission electron microscope, and when the shape of the particles is spherical, the diameter of the sphere is defined as the particle diameter, and when the shape of the particles is needle-shaped or rod-shaped, the minor diameter is defined as the particle diameter. In the case of a fixed form, the average particle size from the center is used as the particle size, and the average value of the particle size of 100 fine particles is used as the average particle size.

The content of silica is preferably 20 parts by mass or more, more preferably 30 parts by mass or more, still more preferably 40 parts by mass or more, and particularly preferably 45 parts by mass or more, based on 100 parts by mass of the rubber component. It is preferably 120 parts by mass or less, more preferably 90 parts by mass or less, still more preferably 70 parts by mass or less, and particularly preferably 60 parts by mass or less. Within the above range, the effect tends to be better obtained.

In the rubber composition, the silica content and the total styrene content in the rubber component satisfy the following formula (B).
(B) Silica content> Total amount of styrene in the rubber component In the formula (B), the silica content is the content (unit: parts by mass) with respect to 100 parts by mass of the rubber component, and is contained in the rubber component. The total amount of styrene is the content (unit: mass%) in 100% by mass of the rubber component.

| Silica content-total amount of styrene in the rubber component | is preferably 4 or more, more preferably 9 or more, still more preferably 13 or more, and preferably 20 or less, more preferably 18 or less, still more preferable. Is 15 or less. Within the above range, the effect tends to be better obtained.

In the rubber composition, the carbon black content and the silica content satisfy the following formula (C).
(C) Carbon black content / silica content ≧ 1.5
In the formula (C), the content of carbon black and the content of silica are the contents (unit: parts by mass) with respect to 100 parts by mass of the rubber component.

In the formula (C), the carbon black content / silica content is preferably 5.0 or less, more preferably 3.0 or less, still more preferably 2.0 or less. Within the above range, the effect tends to be better obtained.

Silica is preferably used in combination with a silane coupling agent.
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. As commercially available products, for example, products such as Degussa, Momentive, Shinetsu Silicone Co., Ltd., Tokyo Chemical Industry Co., Ltd., Azumax Co., Ltd., Toray Dow Corning Co., Ltd. can be used. These may be used alone or in combination of two or more. Of these, the mercapto system is preferable.

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、−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) 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 , -NR ¹⁰⁰⁶ R ¹⁰⁰⁷ and-(OSiR ¹⁰⁰⁶ R ¹⁰⁰⁷ ) _h (OSiR) ¹⁰⁰⁶ R ¹⁰⁰⁷ R ¹⁰⁰⁸⁾ a monovalent group selected from ^{(R 1006, R 1007} and ^{R 1008} may be the same or different, be each a hydrogen atom or a monovalent hydrocarbon group having 1 to 18 carbon atoms , 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 − [O (R ¹⁰⁰⁹ O) _j. ^{] -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, and R ¹⁰⁰⁵ is 1 carbon atom. It represents a monovalent hydrocarbon group of ~ 18, and x, y and z are numbers that satisfy the relationship of x + y + 2z = 3, 0 ≦ x ≦ 3, 0 ≦ y ≦ 2, 0 ≦ z ≦ 1).

(In the equation, v is an integer of 0 or more, w is an integer of 1 or more. R ¹¹ is a hydrogen, halogen, branched or unbranched alkyl group having 1 to 30 carbon atoms, branched or unbranched carbon number 2 to 2. 30 alkenyl groups, branched or unbranched alkynyl groups with 2 to 30 carbon atoms, or the hydrogen at the end of the alkyl group substituted with a hydroxyl group or a carboxyl group. R ¹² 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 11} and R ^12. 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, respectively. 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 a linear group. ^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 formula (II), the content of the binding 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. 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 11} in the 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 a vinyl group and a 1-propenyl group. Examples of the branched or unbranched alkynyl group having 2 to 30 carbon atoms include an ethynyl group and a propynyl group.

^{Regarding R 12} 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 unbranched 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 (v) of the binding unit A and the number of repetitions (w) of the binding unit B. The total number of repetitions (v + w) is preferably in the range of 3 to 300.

The content of the silane coupling agent is preferably 3 parts by mass or more, more preferably 6 parts by mass or more, still more preferably 8 parts by mass or more, and preferably 15 parts by mass or less with respect to 100 parts by mass of silica. , More preferably 12 parts by mass or less, still more preferably 10 parts by mass or less. Within the above range, the effect tends to be better obtained.

The rubber composition preferably contains an aromatic resin.
The aromatic resin is a polymer containing an aromatic monomer as a constituent monomer. For example, a homopolymer obtained by polymerizing one aromatic monomer alone, or two or more aromatic monomers. In addition to the copolymer obtained by copolymerizing the above, examples thereof include an aromatic monomer and a copolymer with another monomer copolymerizable therewith. Further, the aromatic resin is preferably in a solid state at room temperature (25 ° C.).

Examples of the aromatic monomer include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-methoxystyrene, p-tert-butylstyrene, p-phenylstyrene, and the like. Styrene-based monomers such as o-chlorostyrene, m-chlorostyrene, p-chlorostyrene; phenol-based monomers such as phenol, alkylphenol and alkoxyphenol; naphthol-based monomers such as naphthol, alkylnaphthol and alkoxynaphthol. ; Kumaron, Phenol, etc. can be mentioned. These may be used alone or in combination of two or more. Of these, styrene-based monomers are preferable, and styrene and α-methylstyrene are more preferable.

The aromatic resin is preferably an α-methylstyrene resin (α-methylstyrene homopolymer, a copolymer of α-methylstyrene and styrene, etc.) because the effect tends to be better. , A polymer of α-methylstyrene and styrene is more preferred.

The content of the aromatic resin is preferably 5 parts by mass or more, more preferably 8 parts by mass or more, still more preferably 10 parts by mass or more, and preferably 30 parts by mass with respect to 100 parts by mass of the rubber component. Hereinafter, it is more preferably 20 parts by mass or less, still more preferably 15 parts by mass or less. Within the above range, the effect tends to be better obtained.

The rubber composition preferably contains a terpene-based resin.
The terpene-based resin is a polymer containing a terpene compound (terpene-based monomer) as a constituent monomer. In addition to the coalescence, a terpene compound and a copolymer with another monomer copolymerizable therewith may also be mentioned. Further, the terpene resin is preferably in a solid state at room temperature (25 ° C.).

Terpene _compounds, hydrocarbon and oxygenated derivatives represented by a composition of _{(C 5} H _{8) n,} monoterpenes _(C 10 _{H 16),} sesquiterpene _(C 15 _{H 24),} diterpenes _(C 20 _{H 32} ) Etc., which are compounds having a terpene as a basic skeleton, and are, for example, α-pinene, β-pinene, dipentene, limonene, milsen, aloocimen, osimene, α-ferandrene, α-terpinene, γ-terpinene, and terpinene. , 1,8-Cineol, 1,4-Cineol, α-terpineol, β-terpineol, γ-terpineol and the like. These may be used alone or in combination of two or more.

The terpene-based resin is preferably a copolymer of a terpene compound and an aromatic monomer (aromatically modified terpene resin) because the effect tends to be better obtained, and a copolymer of the terpene compound and styrene is preferable. A polymer (terpene styrene resin) is more preferable.
In addition, in this specification, a polymer containing a terpene compound and an aromatic monomer as a constituent monomer, such as a terpene styrene resin, is treated as a terpene resin, not an aromatic resin.

The rubber composition may contain a resin other than the aromatic resin and the terpene resin. The resin that can be used is not particularly limited as long as it is widely used in the tire industry, and examples thereof include rosin-based resins and acrylic-based resins. These may be used alone or in combination of two or more.

Examples of commercially available products of the above-mentioned resins include 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., and Nikko Chemical Co., Ltd. ), Nippon Shokubai Co., Ltd., JXTG Energy Co., Ltd., Arakawa Chemical Industry Co., Ltd., Taoka Chemical Industry Co., Ltd., etc. can be used.

The content of the resin (when a plurality of kinds of resins are used in combination, the total content thereof) is preferably 10 parts by mass or more, more preferably 15 parts by mass or more, and further preferably 20 parts by mass with respect to 100 parts by mass of the rubber component. It is more than parts, preferably 50 parts by mass or less, more preferably 35 parts by mass or less, still more preferably 25 parts by mass or less. Within the above range, the effect tends to be better obtained.

In the rubber composition, it is preferable that the resin content and the silica content satisfy the following formula (E).
(E) 0.1 ≤ resin content / silica content ≤ 1.5
In the formula (E), the content of the resin and the content of silica are the contents (unit: parts by mass) with respect to 100 parts by mass of the rubber component.

In the formula (E), the resin content / silica content is preferably 0.3 or more, more preferably 0.4 or more, and preferably 1.2 or less, more preferably 0.9 or less. , More preferably 0.6 or less. Within the above range, the effect tends to be better obtained.

In the rubber composition, it is preferable that the resin content and the carbon black content satisfy the following formula (F).
(F) 0.1 ≤ resin content / carbon black content ≤ 1.5
In the formula (F), the content of the resin and the content of carbon black are the contents (unit: parts by mass) with respect to 100 parts by mass of the rubber component.

In the formula (F), the resin content / carbon black content is preferably 0.2 or more, more preferably 0.3 or more, and preferably 1.2 or less, more preferably 0.8 or more. Below, it is more preferably 0.5 or less. Within the above range, the effect tends to be better obtained.

The rubber composition preferably contains a dibenzylamine compound.
The dibenzylamine compound is a compound having at least one group represented by the following formula (dibenzylamine group).

Specific examples of the dibenzylamine compound include dibenzylamine, tetrabenzylthiuram disulfide (TBzTD), zinc dibenzyldithiocarbamate, 1,6-bis (N, N'-dibenzylthiocarbamoyldithio) hexane and the like. .. As commercial products, products such as Sanshin Chemical Industry Co., Ltd., Ouchi Shinko Chemical Industry Co., Ltd., and LANXESS Co., Ltd. can be used. These may be used alone or in combination of two or more. Of these, a compound having two dibenzylamine groups is preferable, and tetrabenzylthium disulfide is more preferable.

The content of the dibenzylamine compound is preferably 0.5 parts by mass or more, more preferably 0.8 parts by mass or more, still more preferably 1 part by mass or more, and more preferably 1 part by mass or more, based on 100 parts by mass of the rubber component. Is 5 parts by mass or less, more preferably 3 parts by mass or less, still more preferably 2 parts by mass or less. Within the above range, the effect tends to be better obtained.

The rubber composition preferably contains a liquid polymer.
The liquid polymer is a (co) polymer in a liquid state at room temperature (25 ° C.), and for example, at least one (co) polymer selected from the group consisting of butadiene, isoprene, styrene, farnesene and derivatives thereof. Specific examples thereof include liquid styrene-butadiene copolymer (liquid SBR), liquid butadiene polymer (liquid BR), liquid isoprene polymer (liquid IR), and liquid styrene isoprene copolymer (liquid SIR). Examples thereof include a liquid farnesene polymer and a liquid farnesene butadiene copolymer. Further, the liquid polymer may be subjected to a modification treatment or a hydrogenation treatment. As commercially available products, products such as CRAY VALLEY Co., Ltd. and Kuraray Co., Ltd. can be used. These may be used alone or in combination of two or more. Of these, liquid SBR is preferable.

The weight average molecular weight (Mw) of the liquid polymer is preferably 9000 or less, more preferably 6000 or less, still more preferably 4500 or less, and preferably 100 or more, more preferably 1000 or more, still more preferably 2000 or more. .. Within the above range, the effect tends to be better obtained.

The content of the liquid polymer is preferably 1 part by mass or more, more preferably 5 parts by mass or more, still more preferably 10 parts by mass or more, and preferably 30 parts by mass or less with respect to 100 parts by mass of the rubber component. It is more preferably 20 parts by mass or less, still more preferably 15 parts by mass or less. Within the above range, the effect tends to be better obtained.

The rubber composition preferably contains a calcium compound.
The calcium compound is a compound having calcium, and examples thereof include inorganic salts such as calcium oxide, calcium hydroxide and calcium carbide; and oxoate salts such as calcium carbonate, calcium nitrate and calcium sulfate. Oxyacid salts also include fatty acid salts such as calcium acetate and calcium stearate. Examples of the substance containing a calcium compound include eggshell (main component: calcium carbonate) and WB16 (a mixture of fatty acid calcium, fatty acid amide and fatty acid amide ester) manufactured by Stractol. These may be used alone or in combination of two or more. Of these, oxoacid salts are preferable, and fatty acid salts (fatty acid calcium) are more preferable.

In the above rubber composition, the content of the calcium compound is preferably 0.1 part by mass or more, more preferably 0.2 part by mass or more in terms of calcium element with respect to 100 parts by mass of the rubber component. Further, it is preferably 1.5 parts by mass or less, more preferably 0.9 parts by mass or less, and further preferably 0.6 parts by mass or less. Within the above range, the effect tends to be better obtained.

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; Tetraquis- [methylene-3- (3', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] bis, tris, polyphenolic aging such as methane Examples include preventive agents. As commercial products, products of Seiko Chemical Co., Ltd., Sumitomo Chemical Co., Ltd., Ouchi Shinko Chemical Industry Co., Ltd., Flexis Co., Ltd., etc. can be used. These may be used alone or in combination of two or more.

The content of the antiaging agent is preferably 1 part by mass or more, more preferably 2 parts by mass or more, still more preferably 3 parts by mass or more, and preferably 8 parts by mass or less with respect to 100 parts by mass of the rubber component. , More preferably 6 parts by mass or less, still more preferably 4.5 parts by mass or less. Within the above range, the effect tends to be better obtained.

The rubber composition may contain oil.
Examples of the oil include process oils, vegetable oils and fats, or mixtures thereof. As the process oil, for example, a paraffin-based process oil, an aroma-based process oil, a naphthenic process oil, or the like can be used. Vegetable oils and fats include castor oil, cottonseed oil, linseed oil, rapeseed oil, soybean oil, palm oil, palm oil, peanut oil, rosin, pine oil, pineapple, tall oil, corn oil, rice oil, beni flower oil, and sesame oil. Examples thereof include olive oil, sunflower oil, palm kernel oil, camellia oil, jojoba oil, macadamia nut oil, and tung oil. Commercial products include Idemitsu Kosan Co., Ltd., Sankyo Yuka Kogyo Co., Ltd., JXTG Energy Co., Ltd., Orisoi Co., Ltd., H & R Co., Ltd., Toyokuni Seiyu Co., Ltd., Showa Shell Sekiyu Co., Ltd., Fuji Kosan Co., Ltd., etc. Products can be used. These may be used alone or in combination of two or more.

The content of the oil is preferably 10 parts by mass or more, more preferably 30 parts by mass or more, still more preferably 40 parts by mass or more, and preferably 100 parts by mass or less, based on 100 parts by mass of the rubber component. It is preferably 80 parts by mass or less, more preferably 60 parts by mass or less, and particularly preferably 50 parts by mass or less. Within the above range, the effect tends to be better obtained.

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. As commercial products, products such as Ouchi Shinko Kagaku Kogyo Co., Ltd., Nippon Seiro Co., Ltd., and Seiko Kagaku Co., Ltd. can be used. These may be used alone or in combination of two or more.

The content of the wax 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, more preferably 6 parts by mass or less, based on 100 parts by mass of the rubber component. Is. Within the above range, the effect tends to be better obtained.

The rubber composition may contain stearic acid.
As the stearic acid, conventionally known ones can be used, and as commercially available products, products such as NOF Corporation, Kao Corporation, Wako Pure Chemical Industries, Ltd., and Chiba Fatty Acid Co., Ltd. can be used. These may be used alone or in combination of two or more.

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, more preferably 6 parts by mass or less, based on 100 parts by mass of the rubber component. be. Within the above range, the effect tends to be better obtained.

The rubber composition may contain zinc oxide.
Conventionally known zinc oxide can be used, and commercially available products include Mitsui Metal Mining Co., Ltd., Toho Zinc Co., Ltd., Hakusui Tech Co., Ltd., Shodo Chemical Industry Co., Ltd., and Sakai Chemical Industry Co., Ltd. Products such as can be used. These may be used alone or in combination of two or more.

The content of zinc oxide 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, more preferably 6 parts by mass with respect to 100 parts by mass of the rubber component. It is as follows. Within the above range, the effect tends to be better obtained.

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. As commercial products, products such as Tsurumi Chemical Industry Co., Ltd., Karuizawa Sulfur Co., Ltd., Shikoku Kasei Industry Co., Ltd., Flexis Co., Ltd., Nippon Inui Kogyo Co., Ltd., Hosoi Chemical Industry Co., Ltd., etc. can be used. These may be used alone or in combination of two or more.

The sulfur content is preferably 0.5 parts by mass or more, more preferably 1.5 parts by mass or more, still more preferably 2 parts by mass or more, and preferably 6 parts by mass with respect to 100 parts by mass of the rubber component. Parts or less, more preferably 4 parts by mass or less, still more preferably 3 parts by mass or less. Within the above range, the effect tends to be better obtained.

The rubber composition may contain a vulcanization accelerator.
Examples of the vulcanization accelerator include thiazole-based vulcanization accelerators such as 2-mercaptobenzothiazole and di-2-benzothiazolyl disulfide; tetramethylthiuram disulfide (TMTD) and tetrakis (2-ethylhexyl) thiuram disulfide (TOT-). N) and other thiuram-based vulcanization accelerators; N-cyclohexyl-2-benzothiadylsulfenamide (CBS), N-tert-butyl-2-benzothiazolylsulfenamide (TBBS), N-oxyethylene- Sulfenamide-based vulcanization accelerators such as 2-benzothiazolesulfenamide, N, N'-diisopropyl-2-benzothiazolesulfenamide; guanidine-based additions such as diphenylguanidine, dioltotrilguanidine, orthotrilviguanidine Sulfenamide accelerators can be mentioned. As commercial products, products such as Sumitomo Chemical Co., Ltd. and Ouchi Shinko Chemical Industry Co., Ltd. can be used. These may be used alone or in combination of two or more.

The content of the vulcanization accelerator is preferably 1 part by mass or more, more preferably 2 parts by mass or more, still 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. It is not less than parts by mass, more preferably 8 parts by mass or less, still more preferably 6 parts by mass or less. Within the above range, the effect tends to be better obtained.

In addition to the above components, the rubber composition contains additives generally used in the tire industry, such as organic peroxides; fillers such as talc, alumina, clay, aluminum hydroxide, and mica; and the like. Further may be 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.

In the rubber composition, the amount of acetone extracted satisfies the following formula (D).
(D) Acetone extraction amount ≤ 35% by mass
In the formula (D), the amount of acetone extracted (unit: mass%) was measured by extracting acetone for 24 hours from the vulcanized rubber composition by a method according to JIS K 6229: 2015. Is.

In the formula (D), the amount of acetone extracted is preferably 32% by mass or less, more preferably 31% by mass or less, preferably 10% by mass or more, more preferably 20% by mass or more, still more preferably 26% by mass. % Or more. Within the above range, the effect tends to be better obtained.

The rubber composition can be produced, for example, by kneading each of the above components 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 vulcanization time is usually 5 to 15 minutes.

The rubber composition includes, for example, tread (cap tread), sidewall, base tread, under tread, shoulder, clinch, bead apex, breaker cushion rubber, carcass cord covering rubber, insulation, chafer, inner liner and the like. It can also be used as a tire member (as a rubber composition for a tire) such as a side reinforcing layer of a run-flat tire. Above all, it is suitable for tread.

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

The tread of the tire may be at least partially composed of the rubber composition, and may be entirely composed of the rubber composition.

The above tires (pneumatic tires, etc.) are passenger car tires; truck / bus tires; two-wheeled vehicle tires; high-performance tires; winter tires such as studless tires; run-flat tires having side reinforcing layers; sound absorbing members such as sponges. Tire with sound absorbing member provided in the tire cavity; Tire with a sealing member provided inside the tire or inside the tire cavity with a sealant that can be sealed at the time of puncture; Electronic parts such as sensors and wireless tags are provided inside the tire or inside the tire cavity. It can be used for tires with electronic parts and the like, and is suitable for passenger car tires.

The size of the tire is not particularly limited, and for example, the tire width can be appropriately selected within the range of 100 to 400 mm, the flatness within the range of 25 to 85%, and the rim diameter within the range of 10 to 25 inches. Is. Specific examples include 105 / 50R16, 115 / 50R17, 125 / 55R20, 135 / 45R21, 145 / 45R21, 155 / 45R18, 165 / 45R22, 175 / 45R23, 185 / 60R20, 195 / 55R14, 205 / 40R16, 215. / 40R16, 225 / 40R17, 235 / 40R17, 245 / 40R16, 255 / 40R17, 265 / 40R17, 275 / 35R18, 285 / 30R19, 295 / 45R20 and the like.

なお、タイヤ外径（Ｄｔ）とは、タイヤを適用リムに装着して内圧２５０ｋＰａ・無負荷とした状態のタイヤの外径である。タイヤ断面幅（Ｗｔ）とは、タイヤを適用リムに装着して内圧２５０ｋＰａ・無負荷とした状態のタイヤ側面の模様又は文字など全てを含むサイドウォール間の直線距離、つまり総幅からタイヤの側面の模様、文字などを除いた幅である。 It is preferable that the tire outer diameter Dt and the tire cross-sectional width Wt satisfy the relational expression of the following formula.

The tire outer diameter (Dt) is the outer diameter of the tire in a state where the tire is mounted on the applicable rim and the internal pressure is 250 kPa and no load is applied. The tire cross-sectional width (Wt) is the straight line distance between the sidewalls including all the patterns or characters on the side surface of the tire when the tire is mounted on the applicable rim and the internal pressure is 250 kPa and no load, that is, the side surface of the tire from the total width. It is the width excluding the pattern and characters of.

Specific examples of the tires that can satisfy the above formula include 145 / 60R18, 145 / 60R19, 155 / 55R18, 155 / 55R19, 155 / 70R17, 155 / 70R19, 165 / 55R20, 165 / 55R21, 165 / 60R19, and so on. Examples thereof include 165 / 65R19, 165 / 70R18, 175 / 55R19, 175 / 55R20, 175 / 55R22, 175 / 60R18, 185 / 55R19, 185 / 60R20, 195 / 50R20, and 195 / 55R20.

Tires satisfying the above formula are preferably applied to pneumatic tires for passenger cars. This is because the pneumatic tire for a passenger car satisfying the above formula tends to be more suitable for solving the problem of this case.

The present invention will be specifically described with reference to Examples, but the present invention is not limited thereto.

Hereinafter, various chemicals used in Examples and Comparative Examples will be described.

(Rubber component)
SBR1: Modified SBR synthesized in Production Example 1 below (styrene amount: 40% by mass, vinyl amount: 30% by mass, Mw: 950,000)
SBR2: SLR6430 manufactured by TRINSEO (styrene amount: 40% by mass, vinyl amount: 24% by mass, oil content 37.5 parts by mass with respect to 100 parts by mass of rubber solid content)
SBR3: Modified SBR synthesized in Production Example 2 below (styrene amount: 10% by mass, vinyl amount: 40% by mass, Mw: 200,000)
SBR4: JSR0122 manufactured by JSR Co., Ltd. (Styrene amount: 37% by mass, vinyl amount: 14% by mass, rubber solid content 100 parts by mass and oil content 34 parts by mass)
BR: BR150B manufactured by Ube Industries, Ltd. (Sith amount: 97% by mass, Vinyl amount: 1% by mass)

(Chemicals other than rubber components)
Carbon black: N134 (CTAB specific surface area: 135 m ² / g)
Silica 1: Ultrasil VN3 manufactured by Evonik Degussa (average particle size: 17 nm)
Silica 2: Ultrasil 9100GR manufactured by Evonik Degussa (average particle size: 15 nm)
Silane Coupling Agent 1: Si266 (bis (3-triethoxysilylpropyl) disulfide) manufactured by Evonik Degussa
Silane coupling agent 2: NXT-Z45 manufactured by Momentive (copolymer of bond unit A and bond unit B (bond unit A: 55 mol%, bond unit B: 45 mol%))
Oil: Diana Process NH-70S (aroma process oil) manufactured by Idemitsu Kosan Co., Ltd.
Resin 1: YS resin TO125 manufactured by Yasuhara Chemical Co., Ltd. (terpene styrene resin (copolymer of styrene and terpene compound))
Resin 2: Sylvatraxx4401 manufactured by Arizona Chemical Co., Ltd. (α-methylstyrene resin (copolymer of α-methylstyrene and styrene))
Resin 3: Knit resin Kumaron V-120 (Kumaron inden resin) manufactured by Nikko Kagaku Co., Ltd.
Liquid polymer: Ricon100 manufactured by Crayvalley (liquid SBR, Mw: 4500)
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 processing aid manufactured by Mitsui Metal Mining Co., Ltd .: WB16 manufactured by Structor (a mixture of fatty acid calcium, fatty acid amide and fatty acid amide ester, calcium element content: about 5% by mass)
Sulfur: HK-200-5 (5% by mass oil-containing powdered sulfur) manufactured by Hosoi Chemical Industry Co., Ltd.
Vulcanization Accelerator 1: Noxeller NS (N-tert-butyl-2-benzothiazolyl sulfeneamide) manufactured by Ouchi Shinko Kagaku Kogyo Co., Ltd.
Vulcanization accelerator 2: Noxeller D (diphenylguanidine) manufactured by Ouchi Shinko Chemical Industry Co., Ltd.
Dibenzylamine compound: Suncella TBzTD (tetrabenzylthiuram disulfide) manufactured by Sanshin Chemical Industry Co., Ltd.

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

(Manufacturing Example 2)
SBR3 was obtained by the same method as in Production Example 1 except that the amount of each chemical used was changed.

(Examples and comparative examples)
According to the formulation shown in Table 1, materials other than the dibenzylamine compound, sulfur and vulcanization accelerator are kneaded for 5 minutes under the condition of 150 ° C. using a 1.7 L Banbury mixer manufactured by Kobe Steel, Ltd. And got a kneaded product. Next, a dibenzylamine compound, sulfur and a vulcanization accelerator were added to the obtained kneaded product, and the mixture was kneaded at 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 12 minutes under the condition of 150 ° C. to obtain a test tire (test tire). Size: 175 / 60R18) was manufactured. The following evaluations were performed using the obtained test tires, 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.

(Acetone extraction amount (AE amount))
A sample (vulcanized rubber composition) was taken from the tread of the test tire, and the sample was extracted with acetone for 24 hours by a method according to JIS K 6229: 2015 to measure the amount of acetone extracted (% by mass).

(Wet steering stability)
The lap time when the vehicle equipped with the above test tires on all wheels ran 10 laps on a test course on a wet road surface was measured. In addition, the tires were run under the same conditions using reference tires having a longer lap time than in any of the examples and comparative examples. Then, the difference in the lap time between each Example and Comparative Example and the reference tire is expressed exponentially with Comparative Example 1 as 100. The larger the index, the larger the difference from the lap time of the reference tire (the amount of shortening of the lap time), indicating that the wet steering stability (steering stability on a wet road surface) is excellent.

From Table 1, the examples were superior in wet steering stability to the comparative examples.

Claims (9)

Contains rubber component, carbon black and silica,
A rubber composition for a tire satisfying the following formulas (A) to (D).
(A) Total amount of styrene in rubber component ≧ 20% by mass
(B) Silica content> Total styrene content in rubber component (C) Carbon black content / Silica content ≧ 1.5
(D) Acetone extraction amount ≤ 35% by mass The rubber composition for a tire according to claim 1, which contains an aromatic resin. The rubber composition for a tire according to claim 1 or 2, which contains a liquid polymer. The rubber composition for a tire according to any one of claims 1 to 3, wherein the carbon black has a specific surface area of cetyltrimethylammonium bromide of 110 m ^{2 / g or more.} The rubber composition for a tire according to any one of claims 1 to 4, wherein the average particle size of the silica is 16 nm or less. The rubber composition for a tire according to any one of claims 1 to 5, which contains a terpene resin. The rubber composition for a tire according to any one of claims 1 to 6, which contains a mercapto-based silane coupling agent. The rubber composition for a tire according to any one of claims 1 to 7, which contains a dibenzylamine compound. A tire having a tread using the rubber composition according to any one of claims 1 to 8.