JP2019019266A - Method of producing rubber composition for tire and method of manufacturing tire - Google Patents

Abstract

To provide a method of producing a rubber composition for a tire, which is capable of obtaining better processability even when compounded with a silane coupling agent having a mercapto group, and to provide a method of manufacturing a tire.SOLUTION: The method of producing a rubber composition for a tire, which contains rubber components (A) including at least two rubber components, a predetermined polysulfide compound (B), and a silane coupling agent (C) having a mercapto group, includes: a step X1 of kneading a first rubber component of the rubber components (A) and the polysulfide compound (B); a step X2 of thereafter kneading the silane coupling agent (C); and a step X3 of thereafter kneading a second rubber component of the rubber components (A). The activating ability to a mercapto group of the first rubber component is smaller than that of the second rubber component. The method of manufacturing a tire includes the production method.SELECTED DRAWING: None

Description

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

  In recent years, from the standpoints of resource and energy savings, as well as environmental protection, social demands for reducing carbon dioxide emissions have increased, and various countermeasures such as weight reduction and the use of electric energy have been considered for automobiles. ing. Therefore, it is required to reduce rolling resistance of automobile tires and improve fuel efficiency, and to improve performance such as durability.

  For example, as a method for reducing rolling resistance, there are known methods such as adoption of silica blending, weight reduction of filler, use of a filler having a small reinforcing property, etc. There is a tendency for performance to deteriorate.

  Patent Document 1 discusses the use of a silane coupling agent having a highly reactive mercapto group (mercapto silane coupling agent) for the purpose of improving performance such as fuel efficiency. However, mercapto-based silane coupling agents provide good fuel efficiency, wet grip performance, and wear resistance, while being highly reactive, they gel during kneading with rubber components and have good processability. There is concern that it will get worse.

  Therefore, in Patent Document 2, by further blending a predetermined polysulfide compound with a rubber composition containing a silane coupling agent having a mercapto group, the processability, fuel efficiency, rubber strength, and abrasion resistance of the rubber composition are increased. And improving crack growth resistance in a well-balanced manner.

JP 2009-120819 A JP 2014-47327 A

  However, in the production method described in Patent Document 2, natural rubber and butadiene rubber are used as rubber components, and these are obtained by kneading a silane coupling agent having a mercapto group and a predetermined polysulfide compound in the same kneading step. There is room for further improvement in processability.

  An object of the present invention is to provide a method for producing a rubber composition for a tire and a method for producing a tire that can obtain better processability even when a silane coupling agent having a mercapto group is blended. To do.

  As a result of intensive studies, the present inventors have found that a rubber component (A) containing at least two rubber components, a polysulfide compound (B) represented by the following formula (1) or (2), and a silane cup having a mercapto group In the method for producing a rubber composition for a tire containing a ring agent (C), the first rubber component of the rubber component (A) having a smaller activation ability for mercapto groups and the polysulfide compound (B) are kneaded. Step X1, the subsequent step X2 of kneading the silane coupling agent (C), and then the second rubber having a higher activation ability for mercapto groups than the first rubber component of the rubber component (A). It has been found that the manufacturing method including the step X3 of kneading the components can improve the processability of the unvulcanized rubber and can solve the above problems. The present invention has been completed on top.

（式中、Ｒ¹は、同一または異なって、置換基を有してもよい炭素数３〜１５の１価の炭化水素基を表す。ｎは２〜６の整数を表す。）

（式中、Ｒ²は、同一または異なって、置換基を有してもよい炭素数３〜１５の２価の炭化水素基を表す。ｍは２〜６の整数を表す。）、
［２］前記ゴム成分（Ａ）中、スチレン含有量が２５〜５０質量％、好ましくは２８〜４７質量％、より好ましくは３１〜４４質量％であり、ビニル結合量が１０〜３５モル％、好ましくは１２〜３３モル％、より好ましくは１４〜３１モル％であるジエン系ゴムを５０質量％以上、好ましくは６０質量％、より好ましくは７０質量％含む上記［１］記載の製造方法、
［３］前記スチレン含有量が前記ビニル結合量の２倍以上、好ましくは２．２倍以上である上記［２］記載の製造方法、
［４］メルカプト基を有するシランカップリング剤が、下記式（３）で表される化合物、および／または下記式（４）で表される結合単位Ａと下記式（５）で表される結合単位Ｂとを含む化合物である上記［１］〜［３］のいずれかに記載の製造方法

（式中、Ｒ¹⁰¹〜Ｒ¹⁰³は、直鎖もしくは分岐鎖の炭素数１〜１２のアルキル基、直鎖もしくは分岐鎖の炭素数１〜１２のアルコキシ基、または−Ｏ−（Ｒ¹¹¹−Ｏ）_z−Ｒ¹¹²（ｚ個のＲ¹¹¹は、直鎖もしくは分岐鎖の炭素数１〜３０の２価の炭化水素基を表す。ｚ個のＲ¹¹¹は、それぞれ同一でも異なっていてもよい。Ｒ¹¹²は、直鎖もしくは分岐鎖の炭素数１〜３０のアルキル基、直鎖もしくは分岐鎖の炭素数２〜３０のアルケニル基、炭素数６〜３０のアリール基、または炭素数７〜３０のアラルキル基を表す。ｚは、１〜３０の整数を表す。）で表される基を表す。Ｒ¹⁰¹〜Ｒ¹⁰³はそれぞれ同一でも異なっていてもよい。Ｒ¹⁰⁴は、直鎖もしくは分岐鎖の炭素数１〜６のアルキレン基を表す。）

（式中、ｘは０以上の整数、ｙは１以上の整数である。Ｒ²⁰¹は、水素原子、ハロゲン原子、直鎖もしくは分岐鎖の炭素数１〜３０のアルキル基、直鎖もしくは分岐鎖の炭素数２〜３０のアルケニル基、直鎖もしくは分岐鎖の炭素数２〜３０のアルキニル基、または該アルキル基の末端の水素原子が水酸基もしくはカルボキシル基で置換されたものを表す。Ｒ²⁰²は、直鎖もしくは分岐鎖の炭素数１〜３０のアルキレン基、直鎖もしくは分岐鎖の炭素数２〜３０のアルケニレン基、または、直鎖もしくは分岐鎖の炭素数２〜３０のアルキニレン基を表す。Ｒ²⁰¹とＲ²⁰²とで環構造を形成してもよい。）、
［５］上記［１］〜［４］のいずれかに記載の製造方法で得られるタイヤ用ゴム組成物の加硫前の段階でタイヤ用部材を成形し、他のタイヤ用部材と組み合わせて生タイヤを成形する工程と、前記成形工程で得られた生タイヤを加硫する加硫工程とを含むタイヤの製造方法、
［６］少なくとも２種のゴム成分を含むゴム成分（Ａ）、下記式（１）または（２）で表されるポリスルフィド化合物（Ｂ）、およびメルカプト基を有するシランカップリング剤（Ｃ）を含有するタイヤ用ゴム組成物であって、
前記ゴム成分（Ａ）のうちの第１のゴム成分と前記ポリスルフィド化合物（Ｂ）とを混練りして得られる混練物に前記シランカップリング剤（Ｃ）を加えて混練りし、その後得られる混練物に前記ゴム成分（Ａ）のうちの第２のゴム成分を加えて混練りすることにより得られ、前記第１のゴム成分のメルカプト基に対する活性化能力が前記第２のゴム成分よりも小さいものであるタイヤ用ゴム組成物

（式中、Ｒ¹は、同一または異なって、置換基を有してもよい炭素数３〜１５の１価の炭化水素基を表す。ｎは２〜６の整数を表す。）

（式中、Ｒ²は、同一または異なって、置換基を有してもよい炭素数３〜１５の２価の炭化水素基を表す。ｍは２〜６の整数を表す。）、ならびに
［７］上記［６］記載のタイヤ用ゴム組成物で構成されるタイヤ用部材を備えるタイヤ
に関する。 That is, the present invention
[1] Contains a rubber component (A) containing at least two types of rubber components, a polysulfide compound (B) represented by the following formula (1) or (2), and a silane coupling agent (C) having a mercapto group A method for producing a rubber composition for a tire, comprising:
A step X1 of kneading the first rubber component of the rubber component (A) and the polysulfide compound (B);
The step X2 of adding the silane coupling agent (C) to the kneaded product obtained in the step X1 and kneading, and the second rubber component of the rubber component (A) to the kneaded product obtained in the step X2. Step X3 of adding and kneading
And a method for producing a rubber composition for tires, wherein the first rubber component has a smaller activation ability for mercapto groups than the second rubber component

(In the formula, R ^1, same or different, .n representing a monovalent hydrocarbon group which may having 3 to 15 carbon atoms have a substituent is an integer of 2-6.)

(Wherein R ² is the same or different and represents a C 3-15 divalent hydrocarbon group which may have a substituent; m represents an integer of 2-6);
[2] In the rubber component (A), the styrene content is 25 to 50% by mass, preferably 28 to 47% by mass, more preferably 31 to 44% by mass, and the vinyl bond content is 10 to 35% by mol. The production method according to the above [1], wherein the diene rubber, which is preferably 12 to 33 mol%, more preferably 14 to 31 mol%, contains 50 mass% or more, preferably 60 mass%, more preferably 70 mass%,
[3] The production method according to the above [2], wherein the styrene content is at least twice the vinyl bond amount, preferably at least 2.2 times the vinyl bond amount,
[4] A silane coupling agent having a mercapto group is a compound represented by the following formula (3) and / or a bond unit A represented by the following formula (4) and a bond represented by the following formula (5): The production method according to any one of the above [1] to [3], which is a compound containing unit B

(Wherein R ^{101 to} R ¹⁰³ represent a linear or branched alkyl group having 1 to 12 carbon atoms, a linear or branched alkoxy group having 1 to 12 carbon atoms, or —O— (R ¹¹¹ —O ) _z -R ¹¹² _(z pieces by R ¹¹¹ is .z pieces by R ¹¹¹ representing a divalent hydrocarbon group having 1 to 30 carbon atoms, straight chain or branched chain, may each be the same or different. R ¹¹² is a linear or branched alkyl group having 1 to 30 carbon atoms, a linear or branched alkenyl group having 2 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, or a 7 to 30 carbon atom. Represents an aralkyl group, z represents an integer of 1 to 30.) R ^{101 to} R ¹⁰³ may be the same or different from each other, and R ¹⁰⁴ may be linear or branched. Represents an alkylene group having 1 to 6 carbon atoms.)

(In the formula, x is an integer of 0 or more, and y is an integer of 1 or more. R ²⁰¹ is a hydrogen atom, a halogen atom, a linear or branched alkyl group having 1 to 30 carbon atoms, a linear or branched chain. R ²⁰² represents an alkenyl group having 2 to 30 carbon atoms, a linear or branched alkynyl group having 2 to 30 carbon atoms, or a group in which a hydrogen atom at the terminal of the alkyl group is substituted with a hydroxyl group or a carboxyl group. Represents a linear or branched alkylene group having 1 to 30 carbon atoms, a linear or branched alkenylene group having 2 to 30 carbon atoms, or a linear or branched alkynylene group having 2 to 30 carbon atoms. R ²⁰¹ and R ²⁰² may form a ring structure).
[5] A tire member is formed at a stage before vulcanization of the tire rubber composition obtained by the production method according to any one of [1] to [4] above, and combined with other tire members. A method for producing a tire, comprising: a step of molding a tire; and a vulcanization step of vulcanizing the raw tire obtained in the molding step,
[6] A rubber component (A) containing at least two rubber components, a polysulfide compound (B) represented by the following formula (1) or (2), and a silane coupling agent (C) having a mercapto group A tire rubber composition comprising:
It is obtained by adding the silane coupling agent (C) to a kneaded product obtained by kneading the first rubber component of the rubber component (A) and the polysulfide compound (B), and then kneading. It is obtained by adding the second rubber component of the rubber component (A) to the kneaded product and kneading, and the activation capability of the first rubber component for mercapto groups is higher than that of the second rubber component. Tire rubber composition which is small

(In the formula, R ^1, same or different, .n representing a monovalent hydrocarbon group which may having 3 to 15 carbon atoms have a substituent is an integer of 2-6.)

(In the formula, R ² is the same or different and represents a divalent hydrocarbon group having 3 to 15 carbon atoms which may have a substituent. M represents an integer of 2 to 6), and [ 7] It relates to a tire provided with the member for tires comprised with the rubber composition for tires of the above-mentioned [6].

  In the manufacturing method of the rubber composition for tires of this invention containing the rubber component (A) containing at least 2 types of rubber components, the predetermined polysulfide compound (B), and the silane coupling agent (C) which has a mercapto group. In the step X1, the first rubber component of the rubber component (A) and the polysulfide compound (B) are kneaded, and the silane coupling agent (C) is added to the kneaded product obtained in the step X1. In addition, the step X2 of kneading, and the step X3 of adding and kneading the second rubber component of the rubber component (A) to the kneaded product obtained in the step X2, According to the method for producing a tire rubber composition having an activation ability for mercapto groups smaller than that of the second rubber component, the processability of the unvulcanized rubber can be further improved.

  The present invention provides a rubber component (A) containing at least two rubber components, a polysulfide compound (B) represented by the formula (1) or (2), and a silane coupling agent (C) having a mercapto group. It is a manufacturing method of the rubber composition for tires to contain. In this production method, the first rubber component of the rubber component (A) and the polysulfide compound (B) are kneaded, and the silane coupling agent is added to the kneaded product obtained in the step X1. (C) adding and kneading step X2, and adding the second rubber component of the rubber component (A) to the kneaded product obtained in the step X2 and kneading step X3, The rubber component has a smaller activation ability for mercapto groups than the second rubber component.

  In a compound containing a rubber component and silica, by using a silane coupling agent having a mercapto group, low fuel consumption performance and wet grip performance can be improved in a balanced manner, and improvement in wear resistance performance can also be expected. However, on the other hand, there are problems in processability such as deterioration of the sheet material during mixing. The reason for this is thought to be that the mercapto group of the silane coupling agent is easily radicalized at the time of mixing and is bonded to the rubber component to gel. On the other hand, in the present invention, the radicalized mercapto group of the silane coupling agent reacts with a predetermined polysulfide compound to form a -SS-bond before reacting with the rubber component (i.e., By capturing a radical derived from a mercapto group with a predetermined polysulfide compound), the reactivity between the silane coupling agent and the rubber component is lowered, and gelation can be prevented. Here, since the reactivity of the silane coupling agent having a mercapto group is very high, in the present invention, a predetermined polysulfide compound is not simultaneously with the silane coupling agent having a mercapto group, but a silane cup having a mercapto group. The rubber component is kneaded before the silane coupling agent having a mercapto group so that the radical can be efficiently captured from the time when the ring agent starts to radicalize. Also, when two or more rubber components having different reactivity with mercapto groups are used, polysulfide can be obtained by kneading from a rubber component having a smaller activation ability of mercapto groups with a silane coupling agent having a mercapto group. Even if there is room for improvement in scavenging of radicals by the compound, it is considered that gelation caused by a silane coupling agent having a mercapto group can be more reliably reduced. When the temperature rises during vulcanization, the disulfide bond due to the predetermined polysulfide compound and mercapto group is broken, and it is considered that it can react with the rubber component and function as a silane coupling agent.

  Here, in the present specification, the activation ability of the rubber component with respect to the mercapto group is the reactivity with respect to the mercapto group of the rubber component, and the rubber component having a higher activation ability has a silane coupling agent having a mercapto group. When kneaded, gelation as described above proceeds, and the surface state of the sheet dough deteriorates. For this reason, the activation ability with respect to the mercapto group of each rubber component is evaluated by using the surface roughness when a sheet fabric is formed using a silane coupling agent having a mercapto group as an index. The surface roughness was determined by using a silane coupling agent having a specific mercapto group, adding a specific amount of the silane coupling agent to 100 parts by mass of the rubber component to be evaluated, and kneading to produce a rubber sheet. The surface roughness of the rubber fabric surface is measured with a surface roughness meter in accordance with the arithmetic average roughness Ra of JIS B 0601. Moreover, the rubber component used as a reference | standard is determined about the obtained result, the index | exponent (activation ability index) of each rubber component is calculated | required by setting the average surface roughness (Ra) obtained with the rubber component to 100, and this index | exponent To compare the activation ability of each rubber component for mercapto groups.

  The rubber component (A) in the present invention is not particularly limited except that it contains at least two types of rubber components having different activation capacities for mercapto groups, and appropriately combined with rubber components used in conventional tire rubber compositions. Can be used. In the present specification, for convenience, when two kinds of rubber components are included, the one having a smaller activation ability for mercapto groups is used as the first rubber component, and the one having a larger activation ability for mercapto groups is used as the second rubber. Ingredients. Which of these first and second rubber components is applicable depends on the rubber component to be combined, and therefore what kind of rubber component is included as the first and second rubber components is particularly limited. It is not a thing. Moreover, in this invention, it is other rubber components other than the 1st and 2nd rubber component, Comprising: The activation ability with respect to a mercapto group is larger than a 1st rubber component, It reacts with a mercapto group rather than a 2nd rubber component. A rubber component having a small activation ability can be contained.

  In this invention, since the one where the difference in the activation ability with respect to the mercapto group with a 1st rubber component and a 2nd rubber component is large can exhibit the effect of this invention more, it is preferable. For example, the difference between the first rubber component and the second rubber component in the activation ability index for the mercapto group is preferably 5 or more, more preferably 10 or more, and 15 or more. Further preferred.

  In the present invention, the rubber component contained in the rubber component (A) includes, for example, isoprene-based rubber including natural rubber (NR) and polyisoprene rubber (IR), butadiene rubber (BR), styrene butadiene rubber (SBR), Examples thereof include diene rubber components such as styrene isoprene butadiene rubber (SIBR), chloroprene rubber (CR), acrylonitrile butadiene rubber (NBR), and butyl rubber. The ability to activate mercapto groups of these rubber components cannot be determined unconditionally because they vary depending on the presence and type of modifying groups, the proportion of monomer units contained, etc. The content of double bonds, particularly the proportion of double bonds located at the ends such as 1,2-vinyl bonds, has an influence. The rubber component (A) of the present invention preferably includes at least one rubber component containing a conjugated diene compound, and SBR from the viewpoint of a balance between fuel efficiency, wear resistance, durability, and wet grip performance. And BR are preferably contained.

  Furthermore, in the present invention, as the diene rubber, it is possible to use a diene rubber having a styrene content of 25 to 50% by mass and a vinyl bond content of 10 to 35 mol%. This is preferable because low fuel consumption can be obtained with a good balance. Examples of the diene rubber containing styrene and vinyl include SBR and SIBR.

The styrene content of the diene rubber is preferably 25% by mass or more, more preferably 28% by mass or more, and further preferably 31% by mass or more from the viewpoint of grip performance. If the styrene content is too high, the styrene groups are adjacent to each other, the polymer becomes too hard, the cross-linking tends to be non-uniform, the blowability during high-temperature running may be deteriorated, and the temperature dependency increases and the temperature changes. Therefore, the styrene content of the diene rubber is preferably 50% by mass or less, and 47% by mass or less. Is more preferable, and 44 mass% or less is further more preferable. In the present specification, the styrene content of the diene rubber is calculated by ¹ H-NMR measurement.

  The vinyl bond amount of the diene rubber is preferably 10 mol% or more, more preferably 12 mol% or more, and further preferably 14 mol% or more from the viewpoint of ensuring the reactivity with silica, rubber strength and wear resistance. Further, the vinyl bond amount of the diene rubber is preferably 35 mol% or less, more preferably 33 mol% or less, from the viewpoints of prevention of increase in temperature dependency, grip performance, EB (durability), and abrasion resistance. The mol% or less is more preferable. In addition, in this specification, the vinyl bond amount (1,2-bond butadiene unit amount) of SBR is measured by infrared absorption spectrum analysis.

  The content of the diene rubber in the rubber component when the styrene content is 25 to 50% by mass and the vinyl bond content is 10 to 35% by mole is preferably 50% by mass or more, 60 mass% or more is more preferable, and 70 mass% or more is further more preferable. By setting the content of the diene rubber to 50% by mass or more, there is a tendency that the performance change in a high temperature range can be suppressed and higher grip performance and blowability can be exhibited. In addition, the content of the diene rubber is preferably 90% by mass or less, more preferably 85% by mass or less, and further preferably 80% by mass or less from the viewpoints of wear resistance, grip performance, and fuel efficiency.

  Furthermore, in the diene rubber, the styrene content is preferably 2 times or more, more preferably 2.2 times or more of the vinyl bond amount, for the reason of achieving both wet skid performance and low fuel consumption. The upper limit is not particularly limited, but the diene rubber preferably has a styrene content of 3.0 times or less the vinyl bond content. When the styrene content exceeds 3.0 times the vinyl bond content, the glass transition temperature is excessively increased, and the fuel economy and low temperature properties tend to be remarkably lowered.

  SBR is not particularly limited, and examples thereof include emulsion polymerization SBR (E-SBR), solution polymerization SBR (S-SBR), and the like, and may or may not be oil-extended. Further, terminal-modified S-SBR and main chain-modified S-SBR with enhanced interaction force with the filler can also be used. Furthermore, hydrogenated products of these SBRs (hydrogenated SBR) can also be used. These SBR may be used independently and may use 2 or more types together.

  The BR is not particularly limited. For example, BR having a cis content of 95% or more (high cis BR), a rare earth butadiene rubber synthesized using a rare earth element-based catalyst (rare earth BR), and a syndiotactic polybutadiene crystal. Commonly used in the tire industry such as BR to be contained (SPB-containing BR) and modified BR can be used. Especially, it is preferable to use high cis BR from the point that it is excellent in abrasion resistance.

  The content of BR in the rubber component in the case of containing BR is preferably 5% by mass or more, and more preferably 10% by mass or more. When the BR content is less than 5% by mass, the effect of improving the wear resistance tends to be difficult to obtain. The BR content is preferably 35% by mass or less, and more preferably 25% by mass or less. When the content of BR exceeds 35% by mass, the dry grip performance tends to be remarkably lowered and the wet grip performance tends to be remarkably lowered.

（式中、Ｒ¹は、同一または異なって、置換基を有してもよい炭素数３〜１５の１価の炭化水素基を表す。ｎは、２〜６の整数を表す。）

（式中、Ｒ²は、同一または異なって、置換基を有してもよい炭素数３〜１５の２価の炭化水素基を表す。ｍは、２〜６の整数を表す。） The predetermined polysulfide compound in the present invention is a compound represented by the following formula (1) or (2).

(In the formula, R ^1, same or different, .n representing a monovalent hydrocarbon group which may having 3 to 15 carbon atoms have a substituent, represents an integer from 2 to 6.)

(Wherein, R ² are the same or different, .m representing a divalent hydrocarbon group which may having 3 to 15 carbon atoms have a substituent, represents an integer from 2 to 6.)

R ¹ in the formula (1) is a monovalent hydrocarbon group having 3 to 15 carbon atoms which may have a substituent, and the carbon number is preferably 5 to 12, and 6 to 10 is More preferred. The monovalent hydrocarbon group for R ¹ may be linear, branched or cyclic, and is a saturated or unsaturated hydrocarbon group (aliphatic, alicyclic, aromatic hydrocarbon group, etc.). Either is acceptable. Of these, an aromatic hydrocarbon group which may have a substituent is preferable.

Examples of R ¹ include an alkyl group having 3 to 15 carbon atoms, a substituted alkyl group, a cycloalkyl group, a substituted cycloalkyl group, an aralkyl group, and a substituted aralkyl group. Among these, an aralkyl group and a substituted aralkyl group are exemplified. preferable. Here, examples of the alkyl group include a butyl group and an octyl group, examples of the cycloalkyl group include a cyclohexyl group, and examples of the aralkyl group include a benzyl group and a phenethyl group. Examples of the substituent include polar groups such as an oxo group (═O), a hydroxy group, a carboxyl group, a carbonyl group, an amino group, an acetyl group, an amide group, and an imide group.

  N in the above formula (1) is an integer of 2 to 6, preferably 2 or 3, and more preferably 2.

R ² in the above formula (2) is an optionally substituted divalent hydrocarbon group having 3 to 15 carbon atoms, preferably 3 to 10 carbon atoms. Is more preferable. The divalent hydrocarbon group for R ² may be linear, branched or cyclic, and may be a saturated or unsaturated hydrocarbon group (such as an aliphatic, alicyclic or aromatic hydrocarbon group). Either is acceptable. Especially, the aliphatic hydrocarbon group which may have a substituent is preferable, and a linear aliphatic hydrocarbon group is more preferable.

Examples of R ² include an alkylene group having 3 to 15 carbon atoms and a substituted alkylene group. Here, examples of the alkylene group include a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, and a nonylene group, and examples of the substituent include those similar to the substituent for R ¹ .

  M in the above formula (2) is an integer of 2 to 6, preferably 2 or 3, and more preferably 2.

  Specific examples of the polysulfide compound represented by the above formula (1) or (2) include N, N′-di (γ-butyrolactam) disulfide, N, N′-di (5-methyl-γ-butyrolactam) disulfide. N, N′-di (5-ethyl-γ-butyrolactam) disulfide, N, N′-di (5-isopropyl-γ-butyrolactam) disulfide, N, N′-di (5-methoxy-γ-butyrolactam) Disulfide, N, N′-di (5-ethoxy-γ-butyrolactam) disulfide, N, N′-di (5-chloro-γ-butyrolactam) disulfide, N, N′-di (5-nitro-γ-butyrolactam) ) Disulfide, N, N′-di (5-amino-γ-butyrolactam) disulfide, N, N′-di (δ-valerolactam) disulfide, N, N′-di (δ -Caprolactam) disulfide, N, N'-di (ε-caprolactam) disulfide, N, N'-di (3-methyl-δ-caprolactam) disulfide, N, N'-di (3-ethyl-ε-caprolactam) Disulfide, N, N′-di (3-isopropyl-ε-caprolactam) disulfide, N, N′-di (δ-methoxy-ε-caprolactam) disulfide, N, N′-di (3-ethoxy-ε-caprolactam ) Disulfide, N, N′-di (3-chloro-ε-caprolactam) disulfide, N, N′-di (δ-nitro-ε-caprolactam) disulfide, N, N′-di (3-amino-ε-) Caprolactam) disulfide, N, N′-di (ω-heptalactam) disulfide, N, N′-di (ω-octalactam) disulfide, dithiodi Caprolactam, morpholine disulfide, N- benzyl -N - [(dibenzylamino) disulfanyl] phenyl methanamine (N, N'-dithiobis (dibenzyl amine)), and the like. Of these, dithiodicaprolactam (hereinafter also referred to as caprolactam disulfide) is preferable. In the present invention, the polysulfide compounds represented by the above formula (1) or (2) may be used alone or in combination of two or more.

  The content of the polysulfide compound is preferably 0.3 parts by mass or more, more preferably 0.4 or more, and further preferably 0.5 parts by mass or more with respect to 100 parts by mass of silica. When the content of the polysulfide compound is 0.3 parts by mass or more, the dough of the unvulcanized rubber sheet after kneading tends to be remarkably smooth. Moreover, 8 mass parts or less are preferable with respect to 100 mass parts of silica, and, as for content of a polysulfide compound, 4 mass parts or less are more preferable. By setting the content of the polysulfide compound to 10 parts by mass or less, there is a tendency that deterioration in fracture strength and deterioration in wear resistance are eliminated.

  The content of the polysulfide compound is preferably 1 part by mass or more and more preferably 3 parts by mass or more with respect to 100 parts by mass of the silane coupling agent having a mercapto group. By setting the content of the polysulfide compound to 1 part by mass or more, the dough of the unvulcanized rubber sheet after kneading tends to be remarkably smooth. Moreover, 100 mass parts or less are preferable with respect to 100 mass parts of silane coupling agents which have a mercapto group, and, as for content of a polysulfide compound, 50 mass parts or less are more preferable. By setting the content of the polysulfide compound to 100 parts by mass or less, there is a tendency that deterioration in fracture strength and deterioration in wear resistance are eliminated.

（式中、Ｒ¹⁰¹〜Ｒ¹⁰³は、直鎖もしくは分岐鎖の炭素数１〜１２のアルキル基、直鎖もしくは分岐鎖の炭素数１〜１２のアルコキシ基、または−Ｏ−（Ｒ¹¹¹−Ｏ）_z−Ｒ¹¹²（ｚ個のＲ¹¹¹は、直鎖もしくは分岐鎖の炭素数１〜３０の２価の炭化水素基を表す。ｚ個のＲ¹¹¹は、それぞれ同一でも異なっていてもよい。Ｒ¹¹²は、直鎖もしくは分岐鎖の炭素数１〜３０のアルキル基、直鎖もしくは分岐鎖の炭素数２〜３０のアルケニル基、炭素数６〜３０のアリール基、または炭素数７〜３０のアラルキル基を表す。ｚは、１〜３０の整数を表す。）で表される基を表す。Ｒ¹⁰¹〜Ｒ¹⁰³はそれぞれ同一でも異なっていてもよい。Ｒ¹⁰⁴は、直鎖もしくは分岐鎖の炭素数１〜６のアルキレン基を表す。）

（式中、ｘは０以上の整数、ｙは１以上の整数である。Ｒ²⁰¹は、水素原子、ハロゲン原子、直鎖もしくは分岐鎖の炭素数１〜３０のアルキル基、直鎖もしくは分岐鎖の炭素数２〜３０のアルケニル基、直鎖もしくは分岐鎖の炭素数２〜３０のアルキニル基、または該アルキル基の末端の水素原子が水酸基もしくはカルボキシル基で置換されたものを表す。Ｒ²⁰²は、直鎖もしくは分岐鎖の炭素数１〜３０のアルキレン基、直鎖もしくは分岐鎖の炭素数２〜３０のアルケニレン基、または、直鎖もしくは分岐鎖の炭素数２〜３０のアルキニレン基を表す。Ｒ²⁰¹とＲ²⁰²とで環構造を形成してもよい。） The silane coupling agent having a mercapto group in the present invention is a compound represented by the following formula (3) and / or a bond unit A represented by the following formula (4) and a bond represented by the following formula (5). A compound containing unit B is preferred.

(Wherein R ^{101 to} R ¹⁰³ represent a linear or branched alkyl group having 1 to 12 carbon atoms, a linear or branched alkoxy group having 1 to 12 carbon atoms, or —O— (R ¹¹¹ —O ) _z -R ¹¹² _(z pieces by R ¹¹¹ is .z pieces by R ¹¹¹ representing a divalent hydrocarbon group having 1 to 30 carbon atoms, straight chain or branched chain, may each be the same or different. R ¹¹² is a linear or branched alkyl group having 1 to 30 carbon atoms, a linear or branched alkenyl group having 2 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, or a 7 to 30 carbon atom. Represents an aralkyl group, z represents an integer of 1 to 30.) R ^{101 to} R ¹⁰³ may be the same or different from each other, and R ¹⁰⁴ may be linear or branched. Represents an alkylene group having 1 to 6 carbon atoms.)

(In the formula, x is an integer of 0 or more, and y is an integer of 1 or more. R ²⁰¹ is a hydrogen atom, a halogen atom, a linear or branched alkyl group having 1 to 30 carbon atoms, a linear or branched chain. R ²⁰² represents an alkenyl group having 2 to 30 carbon atoms, a linear or branched alkynyl group having 2 to 30 carbon atoms, or a group in which a hydrogen atom at the terminal of the alkyl group is substituted with a hydroxyl group or a carboxyl group. Represents a linear or branched alkylene group having 1 to 30 carbon atoms, a linear or branched alkenylene group having 2 to 30 carbon atoms, or a linear or branched alkynylene group having 2 to 30 carbon atoms. R ²⁰¹ and R ²⁰² may form a ring structure.)

  Hereinafter, the compound represented by the formula (3) will be described.

R ^{101 to} R ¹⁰³ are each a linear or branched alkyl group having 1 to 12 carbon atoms, a linear or branched alkoxy group having 1 to 12 carbon atoms, or —O— (R ¹¹¹ —O) _z —R. ^The group represented by ¹¹² is represented. From the viewpoint that the effects of the present invention can be obtained satisfactorily, at least one of R ^{101 to} R ¹⁰³ is preferably a group represented by —O— (R ¹¹¹ —O) _z —R ^112. More preferably, it is a group represented by O— (R ¹¹¹ —O) _z —R ¹¹² , and one is a linear or branched alkoxy group having 1 to 12 carbon atoms.

Examples of the linear or branched alkyl group having 1 to 12 carbon atoms (preferably 1 to 5 carbon atoms) represented by R ^{101 to} R ¹⁰³ include, for example, methyl group, ethyl group, n-propyl group, isopropyl group, n- Examples include a butyl group, an iso-butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a heptyl group, a 2-ethylhexyl group, an octyl group, and a nonyl group.

Examples of the linear or branched alkoxy group having 1 to 12 carbon atoms (preferably 1 to 5 carbon atoms) represented by R ^{101 to} R ¹⁰³ include, for example, methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n -Butoxy group, iso-butoxy group, sec-butoxy group, tert-butoxy group, pentyloxy group, hexyloxy group, heptyloxy group, 2-ethylhexyloxy group, octyloxy group, nonyloxy group and the like can be mentioned.

In —O— (R ¹¹¹ —O) _z —R ¹¹² of R ^{101 to} R ¹⁰³ , R ¹¹¹ is a linear or branched carbon number of 1 to 30 (preferably having a carbon number of 1 to 15, more preferably a carbon number). 1 to 3) represents a divalent hydrocarbon group. Examples of the hydrocarbon group include a linear or branched alkylene group having 1 to 30 carbon atoms, a linear or branched alkenylene group having 2 to 30 carbon atoms, and a linear or branched chain chain having 2 to 30 carbon atoms. Alkynylene group, an arylene group having 6 to 30 carbon atoms, and the like. Of these, a linear or branched alkylene group having 1 to 30 carbon atoms is preferable.

Examples of the linear or branched alkylene group having 1 to 30 carbon atoms (preferably 1 to 15 carbon atoms, more preferably 1 to 3 carbon atoms) as R ¹¹¹ include, for example, a methylene group, an ethylene group, a propylene group, and butylene. Group, pentylene group, hexylene group, heptylene group, octylene group, nonylene group, decylene group, undecylene group, dodecylene group, tridecylene group, tetradecylene group, pentadecylene group, hexadecylene group, heptadecylene group, octadecylene group and the like.

Examples of the linear or branched alkenylene group having 2 to 30 carbon atoms (preferably 2 to 15 carbon atoms, more preferably 2 or 3 carbon atoms) of R ¹¹¹ include, for example, vinylene group, 1-propenylene group, 2- Examples include propenylene group, 1-butenylene group, 2-butenylene group, 1-pentenylene group, 2-pentenylene group, 1-hexenylene group, 2-hexenylene group, 1-octenylene group and the like.

Examples of the linear or branched alkynylene group having 2 to 30 carbon atoms (preferably 2 to 15 carbon atoms, more preferably 2 or 3 carbon atoms) of R ¹¹¹ include, for example, ethynylene group, propynylene group, butynylene group, pentynylene. Group, hexynylene group, heptynylene group, octynylene group, noninylene group, decynylene group, undecynylene group, dodecynylene group and the like.

Examples of the arylene group having 6 to 30 carbon atoms (preferably 6 to 15 carbon atoms) of R ¹¹¹ include a phenylene group, a tolylene group, a xylylene group, and a naphthylene group.

  z is an integer of 1 to 30, preferably 2 to 20, more preferably 3 to 7, and still more preferably 5 or 6.

R ¹¹² is a linear or branched alkyl group having 1 to 30 carbon atoms, a linear or branched alkenyl group having 2 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, or an aralkyl having 7 to 30 carbon atoms. Represents a group. Of these, a linear or branched alkyl group having 1 to 30 carbon atoms is preferred.

Examples of the linear or branched alkyl group having 1 to 30 carbon atoms (preferably 3 to 25 carbon atoms, more preferably 10 to 15 carbon atoms) of R ¹¹² include, for example, a methyl group, an ethyl group, and an n-propyl group. , Isopropyl group, n-butyl group, iso-butyl group, sec-butyl group, tert-butyl group, pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group, nonyl group, decyl group, undecyl group, Examples include dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, octadecyl group and the like.

Examples of the straight chain or branched chain alkenyl group of R ¹¹² having 2 to 30 carbon atoms (preferably 3 to 25 carbon atoms, more preferably 10 to 15 carbon atoms) include, for example, vinyl group, 1-propenyl group, 2- Propenyl group, 1-butenyl group, 2-butenyl group, 1-pentenyl group, 2-pentenyl group, 1-hexenyl group, 2-hexenyl group, 1-octenyl group, decenyl group, undecenyl group, dodecenyl group, tridecenyl group, Examples include a tetradecenyl group, a pentadecenyl group, and an octadecenyl group.

Examples of the aryl group having 6 to 30 carbon atoms (preferably 10 to 20 carbon atoms) represented by R ¹¹² include a phenyl group, a tolyl group, a xylyl group, a naphthyl group, and a biphenyl group.

Examples of the aralkyl group having 7 to 30 carbon atoms (preferably 10 to 20 carbon atoms) of R ¹¹² include a benzyl group and a phenethyl group.

Specific examples of the group represented by —O— (R ¹¹¹ —O) _z —R ¹¹² include, for example, —O— (C ₂ H ₄ —O) ₅ —C ₁₁ H ₂₃ , —O— (C _{2 H 4 -O) 5 -C 12 H} 25, -O- (C 2 H 4 -O) 5 -C 13 H 27, -O- (C 2 H 4 -O) 5 -C 14 H 29, -O _{- (C 2 H 4 -O)} 5 -C 15 H 31, -O- (C 2 H 4 -O) 3 -C 13 H 27, -O- (C 2 H 4 -O) 4 -C 13 H _{27, -O- (C 2 H 4} -O) 6 -C 13 H 27, -O- (C 2 H 4 -O) 7 -C 13 H 27, and the like. Among them, —O— (C ₂ H ₄ —O) ₅ —C ₁₁ H ₂₃ , —O— (C ₂ H ₄ —O) ₅ —C ₁₃ H ₂₇ , —O— (C ₂ H ₄ —O) _{5 -C 15 H 31, -O- (C} 2 H 4 -O) 6 -C 13 H 27 are preferable.

Examples of the linear or branched alkylene group having 1 to 6 carbon atoms (preferably 1 to 5 carbon atoms) of R ¹⁰⁴ are the same as, for example, the linear or branched alkylene group having 1 to 30 carbon atoms of R ^111. Can be mentioned.

Examples of the compound represented by the above formula (3) include 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, 2-mercaptoethyltrimethoxysilane, 2-mercaptoethyltriethoxysilane, and the following formula: (Si363 manufactured by Evonik Degussa) and the like, and a compound represented by the following formula can be preferably used. These may be used alone or in combination of two or more.

  Next, the compound containing the bond unit A represented by the above formula (4) and the bond unit B represented by the above formula (5) will be described.

  The compound containing the bond unit A represented by the above formula (4) and the bond unit B represented by the above formula (5) is being processed compared to polysulfide silanes such as bis- (3-triethoxysilylpropyl) tetrasulfide. An increase in the viscosity of the resin is suppressed. This is presumably because the increase in Mooney viscosity is small because the sulfide portion of the bond unit A is a C—S—C bond and is thermally stable compared to tetrasulfide and disulfide.

Moreover, the shortening of the scorch time is suppressed as compared with mercaptosilane such as 3-mercaptopropyltrimethoxysilane. This is because the bonding unit B has a mercaptosilane structure, but the —C ₇ H ₁₅ portion of the bonding unit A covers the —SH group of the bonding unit B, so that it does not easily react with the polymer and scorch is less likely to occur. This is probably because of this.

  In the silane coupling agent having the above structure, the content of the bond unit A is 30 mol% from the viewpoint that the effect of suppressing the increase in viscosity during processing and the effect of suppressing the shortening of the scorch time can be enhanced. The above is preferable, 50 mol% or more is more preferable, 99 mol% or less is preferable, and 90 mol% or less is more preferable. Further, the content of the bonding unit B is preferably 1 mol% or more, more preferably 5 mol% or more, further preferably 10 mol% or more, preferably 70 mol% or less, more preferably 65 mol% or less, and 55 mol%. % Or less is more preferable. Further, the total content of the bonding units A and B is preferably 95 mol% or more, more preferably 98 mol% or more, and particularly preferably 100 mol%. The content of the bond units A and B is an amount including the case where the bond units A and B are located at the terminal of the silane coupling agent. The form in the case where the bonding units A and B are located at the end of the silane coupling agent is not particularly limited as long as the units corresponding to the formulas (4) and (5) indicating the bonding units A and B are formed. .

Examples of the halogen atom for R ²⁰¹ include a chlorine atom, a bromine atom, and a fluorine atom.

^Examples of the linear or branched alkyl group having 1 to 30 carbon atoms of ^R201 include methyl, ethyl, n-propyl, isopropyl, n-butyl, iso-butyl, sec-butyl, tert -Butyl group, pentyl group, hexyl group, heptyl group, 2-ethylhexyl group, octyl group, nonyl group, decyl group and the like can be mentioned. As for carbon number of this alkyl group, 1-12 are preferable.

^Examples of the linear or branched alkenyl group having 2 to 30 carbon atoms represented by R ²⁰¹ include a vinyl group, 1-propenyl group, 2-propenyl group, 1-butenyl group, 2-butenyl group, 1-pentenyl group, 2- A pentenyl group, 1-hexenyl group, 2-hexenyl group, 1-octenyl group and the like can be mentioned. The alkenyl group preferably has 2 to 12 carbon atoms.

^Examples of the linear or branched alkynyl group having 2 to 30 carbon atoms represented by ^R201 include ethynyl group, propynyl group, butynyl group, pentynyl group, hexynyl group, heptynyl group, octynyl group, nonynyl group, decynyl group, and undecynyl group. And dodecynyl group. The alkynyl group preferably has 2 to 12 carbon atoms.

^Examples of the linear or branched alkylene group having 1 to 30 carbon atoms of R ²⁰² include an ethylene group, a propylene group, a butylene group, a pentylene group, a hexylene group, a heptylene group, an octylene group, a nonylene group, a decylene group, and an undecylene group. , Dodecylene group, tridecylene group, tetradecylene group, pentadecylene group, hexadecylene group, heptadecylene group, octadecylene group and the like. The alkylene group preferably has 1 to 12 carbon atoms.

^Examples of the linear or branched alkenylene group having 2 to 30 carbon atoms of R ²⁰² include vinylene group, 1-propenylene group, 2-propenylene group, 1-butenylene group, 2-butenylene group, 1-pentenylene group, 2- Examples include a pentenylene group, a 1-hexenylene group, a 2-hexenylene group, and a 1-octenylene group. The alkenylene group preferably has 2 to 12 carbon atoms.

Examples of the linear or branched C2-C30 alkynylene group of R ²⁰² include ethynylene group, propynylene group, butynylene group, pentynylene group, hexynylene group, heptynylene group, octynylene group, noninylene group, decynylene group, and undecynylene group. And dodecynylene group. The alkynylene group preferably has 2 to 12 carbon atoms.

In the compound containing the bond unit A represented by the above formula (4) and the bond unit B represented by the above formula (5), the total of the repeating number (x) of the bonding unit A and the repeating number (y) of the bonding unit B Is preferably in the range of 3 to 300. Within this range, the mercaptosilane of the bond unit B is covered with the bond unit A —C ₇ H ₁₅ , so that the scorch time can be prevented from being shortened, and good reactivity with silica and rubber components can be achieved. Can be secured.

  As a compound containing the coupling unit A represented by the above formula (4) and the coupling unit B represented by the above formula (5), for example, NXT-Z30, NXT-Z45, NXT-Z60 manufactured by Momentive, etc. are used. can do. These may be used alone or in combination of two or more.

  The content of the silane coupling agent having a mercapto group is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, further preferably 2 parts by mass or more, particularly preferably 100 parts by mass of silica. It is 4 parts by mass or more. If the amount is less than 0.5 parts by mass, there is a possibility that improvement effects such as low fuel consumption cannot be sufficiently obtained. The content is preferably 20 parts by mass or less, more preferably 12 parts by mass or less, still more preferably 10 parts by mass or less, and particularly preferably 9 parts by mass or less. If it exceeds 20 parts by mass, the rubber strength and wear resistance tend to decrease.

  In the present invention, the rubber composition may further contain another silane coupling agent in addition to the silane coupling agent having a mercapto group. Examples of other silane coupling agents include 3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-triethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide, and 2-triethoxysilyl. Ethyl-N, N-dimethylthiocarbamoyl tetrasulfide, 3-trimethoxysilylpropylbenzothiazole tetrasulfide, 3-triethoxysilylpropylbenzothiazolyl tetrasulfide, 3-triethoxysilylpropyl methacrylate monosulfide, 3-trimethoxy Silylpropyl methacrylate monosulfide, bis (3-triethoxysilylpropyl) tetrasulfide, bis (3-triethoxysilylpropyl) trisulfide, bis (3-triet Sisilylpropyl) disulfide, bis (2-triethoxysilylethyl) tetrasulfide, bis (3-trimethoxysilylpropyl) tetrasulfide, bis (2-trimethoxysilylethyl) tetrasulfide, bis (3-diethoxymethylsilyl) Propyl) tetrasulfide, 3-mercaptopropyldimethoxymethylsilane, dimethoxymethylsilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide, dimethoxymethylsilylpropylbenzothiazole tetrasulfide and the like.

  In the present invention, silica is used. By blending silica, fuel economy, wear resistance, and wet grip performance can be improved. Silica is not particularly limited, and for example, silica that is prepared by a dry method (anhydrous silica), silica that is prepared by a wet method (hydrous silica), and the like used in the tire industry should be used. Can do. Of these, hydrous silica prepared by a wet method is preferred because of its large number of silanol groups. Silica may be used alone or in combination of two or more.

The nitrogen adsorption specific surface area (N ₂ SA) of silica is preferably 20 m ² / g or more, more preferably 30 m ² / g or more, and further preferably 100 m ² / g or more. Also, N ₂ SA is preferably 400 meters ² / g or less, more preferably 300 meters ² / g, more preferably not more than 280m ² / g. If it is in the said range, there exists a tendency for low-fuel-consumption property and workability to be obtained with sufficient balance. Incidentally, N ₂ SA of the silica in this specification is a value measured by the BET method in accordance with ASTM D3037-81.

  The content of silica is preferably 20 parts by mass or more, more preferably 30 parts by mass or more, and still more preferably 40 parts by mass or more with respect to 100 parts by mass of the rubber component. By setting the silica content to 20 parts by mass or more, there is a tendency that the effect of improving the fuel efficiency by blending silica is sufficiently obtained and the effect of improving the wear resistance performance is sufficiently obtained. 120 mass parts or less are preferable with respect to 100 mass parts of rubber components, as for content of a silica, 110 mass parts or less are more preferable, and 100 mass parts or less are more preferable. By controlling the silica content to 120 parts by mass or less, deterioration of dispersibility of silica in rubber is suppressed, better fuel economy and workability tend to be obtained, and better wear resistance can be obtained. Tend.

  In addition to the above components, the rubber composition for tires according to the present invention includes compounding agents generally used in the rubber industry in the past, such as reinforcing fillers other than silica, processing aids, zinc oxide, stearic acid, various Anti-aging agents, softening agents such as pressure-sensitive adhesive resins, vulcanizing agents such as oil, wax and sulfur, various vulcanization accelerators, and the like can be appropriately contained.

  As reinforcing fillers other than silica, those conventionally used in tire rubber compositions such as carbon black, calcium carbonate, alumina, clay and talc can be blended. Among these, carbon black is preferable because it is excellent in reinforcement and wear resistance.

  The carbon black is not particularly limited, and those generally used in the tire industry such as GPF, FEF, HAF, ISAF, and SAF can be used, and fine carbon black manufactured and sold by Mitsubishi Chemical Corporation is preferably used. Can do. These may be used alone or in combination of two or more.

The nitrogen adsorption specific surface area (N ₂ SA) of carbon black is preferably 50 m ² / g or more, more preferably 80 m ² / g or more from the viewpoint of weather resistance and reinforcement. Also, N ₂ SA of carbon black is low fuel consumption, dispersibility, preferably 250 meters ² / g or less from the viewpoint of fracture properties and durability, and more preferably at most 220 m ² / g. In addition, N ₂ SA of carbon black in this specification is a value measured according to A method of JIS K 6217.

  The content with respect to 100 parts by mass of the rubber component in the case of containing carbon black is preferably 3 parts by mass or more, more preferably 5 parts by mass or more from the viewpoint of weather resistance. Further, the content of carbon black is preferably 40 parts by mass or less, and more preferably 30 parts by mass or less from the viewpoints of low fuel consumption and processability.

  Examples of the processing aid include fatty acid metal salts, fatty acid amides, amide esters, silica surfactants, fatty acid esters, mixtures of fatty acid metal salts and amide esters, mixtures of fatty acid metal salts and fatty acid amides, and the like. These may be used alone or in combination of two or more. Of these, a fatty acid metal salt, an amide ester, and a mixture of a fatty acid metal salt and an amide ester or a fatty acid amide are preferable, and a mixture of a fatty acid metal salt and a fatty acid amide is particularly preferable.

  The fatty acid constituting the fatty acid metal salt is not particularly limited, but is saturated or unsaturated fatty acid (preferably having 6 to 28 carbon atoms (more preferably having 10 to 25 carbon atoms, more preferably 14 to 20 carbon atoms). ) Saturated or unsaturated fatty acids), for example, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, arachidic acid, behenic acid, nervonic acid and the like. These may be used alone or in combination of two or more. Especially, a saturated fatty acid is preferable and a C14-20 saturated fatty acid is more preferable.

  Examples of the metal constituting the fatty acid metal salt include alkali metals such as potassium and sodium, alkaline earth metals such as magnesium, calcium and barium, zinc, nickel and molybdenum. Of these, zinc and calcium are preferable, and zinc is more preferable.

  The fatty acid amide may be a saturated fatty acid amide or an unsaturated fatty acid amide. Examples of the saturated fatty acid amide include N- (1-oxooctadecyl) sarcosine, stearic acid amide, and behenic acid amide. Examples of the unsaturated fatty acid amide include oleic acid amide and erucic acid amide.

  As a specific example of the mixture of the fatty acid metal salt and the fatty acid amide, WB16 manufactured by Straktor, which is a mixture of the fatty acid calcium and the fatty acid amide, may be mentioned. Specific examples of the fatty acid zinc salt include Ultra-Flow 440 manufactured by Performance Additives.

  When the processing aid is contained, the content with respect to 100 parts by mass of the rubber component is preferably 0.8 parts by mass or more, and more preferably 1.5 parts by mass or more. If the amount is less than 0.8 part by mass, the effect of addition may not be sufficiently obtained. Moreover, 10 mass parts or less are preferable, as for content of a processing aid, 8 mass parts or less are more preferable, and 6 mass parts or less are more preferable. When the amount exceeds 10 parts by mass, slipping between the polymer phases occurs, and it becomes difficult to obtain a structure in which the polymer phases are interlaced with each other, so that wear resistance tends to deteriorate and fracture strength tends to decrease.

  Examples of the tackifying resin include resins conventionally used in rubber compositions for tires such as aromatic petroleum resins. Examples of aromatic petroleum resins include phenolic resins, coumarone indene resins, terpene resins, styrene resins, acrylic resins, rosin resins, dicyclopentadiene resins (DCPD resins), and the like. Examples of the phenolic resin include colesin (manufactured by BASF) and tackolol (manufactured by Taoka Chemical Industries). Examples of the coumarone indene resin include coumarone (manufactured by Nippon Paint Chemical Co., Ltd.), escron (manufactured by Nippon Steel Chemical Co., Ltd.), neopolymer (manufactured by Nippon Petrochemical Co., Ltd.), and the like. Examples of the styrene resin include Sylvatrax (registered trademark) 4401 (manufactured by Arizona Chemical Co., Ltd.). Examples of the terpene resin include TR7125 (manufactured by Arizona Chemical Co.), TO125 (manufactured by Yasuhara Chemical Co., Ltd.), and the like.

  The softening point of the tackifying resin is preferably 40 ° C. or higher, and more preferably 60 ° C. or higher. By setting the softening point to 40 ° C. or higher, sufficient grip performance tends to be obtained. Further, the softening point is preferably 120 ° C. or lower, and more preferably 100 ° C. or lower. By setting the softening point to 120 ° C. or less, sufficient grip performance tends to be obtained. The softening point of the resin in the present invention is the temperature at which the sphere descends when the softening point specified in JIS K 6220-1: 2001 is measured with a ring and ball softening point measuring device.

  3 mass parts or more are preferable and, as for content with respect to 100 mass parts of rubber components of tackifying resin, 5 mass parts or more are more preferable. When the content of the tackifying resin is 3 parts by mass or more, sufficient grip performance tends to be obtained. Moreover, 30 mass parts or less are preferable and, as for content of tackifying resin, 25 mass parts or less are more preferable. By setting the content of the tackifying resin to 30 parts by mass or less, sufficient wear resistance performance tends to be obtained, and good fuel efficiency performance tends to be obtained.

  In addition, zinc oxide, stearic acid, various anti-aging agents, oil, and wax can be those conventionally used in the rubber industry.

  The vulcanizing agent is not particularly limited, and those commonly used in the rubber industry can be used, but those containing a sulfur atom are preferable, for example, powdered sulfur, precipitated sulfur, colloidal sulfur, surface-treated sulfur, Examples include insoluble sulfur.

  The vulcanization accelerator is not particularly limited. For example, sulfenamide, thiazole, thiuram, thiourea, guanidine, dithiocarbamic acid, aldehyde-amine or aldehyde-ammonia, imidazoline. And xanthate-based vulcanization accelerators, and among them, sulfenamide-based, thiuram-based, and guanidine-based vulcanization accelerators are preferable because the effects of the present invention can be obtained more suitably.

  Examples of the sulfenamide vulcanization accelerator include CBS (N-cyclohexyl-2-benzothiazylsulfenamide), TBBS (Nt-butyl-2-benzothiazylsulfenamide), N-oxyethylene- Examples include 2-benzothiazylsulfenamide, N, N′-diisopropyl-2-benzothiazylsulfenamide, N, N-dicyclohexyl-2-benzothiazylsulfenamide, and the like. Examples of thiazole vulcanization accelerators include 2-mercaptobenzothiazole and dibenzothiazolyl disulfide. Examples of the thiuram vulcanization accelerator include tetramethylthiuram monosulfide, tetramethylthiuram disulfide, and tetrabenzylthiuram disulfide (TBzTD). Examples of the guanidine vulcanization accelerator include diphenyl guanidine (DPG), diortolyl guanidine, orthotolyl biguanidine and the like. These may be used alone or in combination of two or more. Among these, TBBS, TBzTD, and DPG are preferable from the viewpoint that the effects of the present invention can be more suitably obtained, and it is more preferable to use these three types in combination.

  In the method for producing a tire rubber composition of the present invention, as described above, before kneading a silane coupling agent having a mercapto group into a rubber component, the rubber component and the predetermined polysulfide compound are kneaded. In addition, the rubber component to be used is not particularly limited as long as it is kneaded with a silane coupling agent from a rubber component having a smaller mercapto group activation ability. For example, an X kneading step (step X) for kneading a rubber component and a reinforcing filler such as silica mainly, a step X1 for kneading the first rubber component and a polysulfide compound, and then discharging the kneaded product. Without adding a silane coupling agent having a mercapto group and kneading, and further including a step X3 of adding and kneading the second rubber component without discharging the kneaded material, and then obtained. A kneading step (step Y) for kneading a vulcanizing agent and other chemicals other than the vulcanization accelerator in the kneaded product and a F kneading step (step F) for kneading the vulcanizing agent and vulcanization accelerator are performed. Can be implemented. Of course, the kneaded material obtained in the step X1 may be discharged once and used in the next step X2. Similarly, the kneaded material obtained in the step X2 may be discharged once and used in the next step X3. Before kneading the silane coupling agent having a mercapto group into a rubber component, the rubber component and the predetermined polysulfide compound are kneaded, and among the rubber components to be used, the ability to activate a mercapto group Due to the feature of the present invention that the rubber component is kneaded with the coupling agent from the smaller rubber component, even if a silane coupling agent having a mercapto group is used, deterioration of the sheet material of the unvulcanized rubber can be prevented, and the process passes The sex can be improved dramatically.

  Further, the kneading of the silica into the rubber component may be performed in any step other than the F kneading step (step F) of kneading the vulcanizing agent or the vulcanization accelerator, and the total content of silica. Is preferably divided and kneaded in each step.

  In one aspect of the method for producing a rubber composition for a tire of the present invention, for example, a first rubber component, a predetermined polysulfide compound, and a reinforcing agent such as silica or carbon black are kneaded (step X1), and a mercapto is mixed therewith. A silane coupling agent having a group and silica are added and kneaded (step X2), and then the second rubber component and silica are added and kneaded (step X3), and discharged to obtain a kneaded product X. . Thereafter, other various chemicals are added to the obtained kneaded product X, kneaded (step Y), and discharged to obtain a kneaded product Y. Next, a vulcanizing agent and a vulcanization accelerator are added to the obtained kneaded product Y and kneaded (step F), whereby an unvulcanized rubber composition can be obtained.

  The kneading in the process X is preferably performed at a discharge temperature of 140 to 170 ° C. for 1 to 5 minutes as a whole. The kneaded product obtained in the step X is preferably cooled to 80 ° C. or lower, preferably 25 to 45 ° C., and then used in the subsequent step.

  The kneading in the process Y is preferably performed at a discharge temperature of 130 to 160 ° C. for 1 to 5 minutes. It is preferable that the kneaded material obtained in the process Y is cooled to 80 ° C. or less, preferably 25 to 45 ° C., and then used in the subsequent process.

  The kneading in the step F is preferably performed at a discharge temperature of 90 to 130 ° C. for 1 to 5 minutes.

  Each kneading in the method for producing a tire rubber composition of the present invention can be carried out using a known kneader. For example, a mechanical shearing force such as a Banbury mixer, a kneader, or an open roll is added to the material to knead and mix. An apparatus for performing

  A tire rubber composition which is another embodiment of the present invention includes a rubber component (A) containing at least two rubber components, a polysulfide compound (B) represented by the above formula (1) or (2), and A tire rubber composition containing a silane coupling agent (C) having a mercapto group, wherein the first rubber component of the rubber component (A) and the polysulfide compound (B) are kneaded, Thereafter, the silane coupling agent (C) is kneaded, and then the second rubber component of the rubber component (A) is kneaded, and the activation of the first rubber component with respect to mercapto groups is performed. The ability is smaller than that of the second rubber component. The tire rubber composition of the present invention has improved processability. This is because, as described above, the polysulfide compound kneaded into the rubber component forms a -S-S- bond with the mercapto group of the silane coupling agent having a mercapto group to be added, thereby forming a silane coupling agent. It is possible to prevent the rubber component from gelling due to styrene, and to improve the scavenging of radicals by polysulfide compounds by kneading with the silane coupling agent having a mercapto group from the rubber component with the smaller ability to activate the mercapto group Even if there is room for this, it is considered that the gelation caused by the silane coupling agent having a mercapto group can be more reliably reduced.

  The tire rubber composition of the present invention can be produced by the method for producing a tire rubber composition of the present invention described above, and the description of the method for producing a tire rubber composition in the present specification is as described above. The present invention is also applicable to the tire rubber composition, and in the description of the manufacturing method of the tire rubber composition of the present invention in the present specification, various materials and compounding ratios, and the tire rubber composition to be obtained The description relating to properties and the like is also applied to the rubber composition for tires of the present invention.

  The tire manufacturing method of the present invention is a tire molding process in which a tire rubber composition manufactured by the manufacturing method of the present invention is extruded in accordance with the shape of a tire member such as a tire tread at an unvulcanized stage. A molding process for forming an unvulcanized tire (raw tire) by pasting together with other tire members on the machine and molding by a normal method, and this unvulcanized tire (raw tire) in a vulcanizer It is a tire manufacturing method including a vulcanization step of heating and pressurizing. The vulcanization temperature is, for example, 120 ° C. or more and 200 ° C. or less.

  The rubber composition for tires of the present invention can be used for tire members such as tire treads, undertreads, carcass, sidewalls, and beads. In particular, because of excellent abrasion resistance, a tire having a tread composed of the rubber composition of the present invention is preferable.

  The tire of the present invention can be produced by the tire production method of the present invention described above using the tire rubber composition of the present invention, regardless of whether it is a pneumatic tire or a non-pneumatic tire. Examples of pneumatic tires include passenger car tires, truck / bus tires, motorcycle tires, and high-performance tires. In addition, the high-performance tire in this specification is a tire that is particularly excellent in grip performance, and is a concept that includes a competition tire used in a competition vehicle.

  EXAMPLES Hereinafter, although this invention is demonstrated based on an Example, this invention is not limited only to these Examples.

Hereinafter, various chemicals used in Examples and Comparative Examples are shown together.
SBR1: SLR6430 manufactured by Trinceo (mercapto group activation ability index: 90, S-SBR, styrene content: 40% by mass, vinyl bond content: 18 mol%, oil content 37.5% relative to 100 parts by mass of rubber component Oil exhibition including parts by mass)
SBR2: Mercapto group activation ability index: 100, styrene content: 25% by mass, and vinyl bond content: 44 mol% solution polymerization SBR
BR1: BR150B manufactured by Ube Industries, Ltd. (mercapto group activation ability index: 95, vinyl bond content: 1.5 mol%, cis 1,4-content 97%)
BR2: activation capability index of mercapto group: 105, vinyl bond content: 13 mol%, and cis 1,4-content of 36% BR
Polysulfide compound: Renogran CLD80 (caprolactam disulfide) manufactured by Rhein Chemie (80% masterbatch product)
Fine carbon black: carbon black silica with a nitrogen adsorption specific surface area (N ₂ SA) of 180 m ² / g: ULTRASIL® VN3 (N ₂ SA: 175 m ² / g) manufactured by Evonik Degussa
Silane coupling agent A: NXT-Z45 manufactured by Momentive (copolymer of bonding unit A and bonding unit B (bonding unit A: 55 mol%, bonding unit B: 45 mol%))
Silane coupling agent B: Si363 manufactured by Evonik Degussa
Zinc oxide: Zinc Hua No. 1 manufactured by Mitsui Mining & Smelting Co., Ltd. Stearic acid: Bead stearic acid Tsubaki wax manufactured by NOF Co., Ltd .: Ozoace 0355 manufactured by Nippon Seiwa Co., Ltd. (paraffin type)
Oil: VivaTec400 (TDAE oil) manufactured by H & R Co., Ltd.
Styrene resin: Sylvatrax (registered trademark) 4401 manufactured by Arizona Chemical Co. (softening point: 85 ° C.)
Anti-aging agent (1): Antigen 6C (N- (1,3-dimethylbutyl) -N′-phenyl-p-phenylenediamine) manufactured by Sumitomo Chemical Co., Ltd.
Anti-aging agent (2): NOCRACK 224 (TMQ, 2,2,4-trimethyl-1,2-dihydroquinoline polymer) manufactured by Ouchi Shinsei Chemical Co., Ltd.
Processing aid (1): Ultra-Flow (registered trademark) 440 (natural fatty acid zinc / metal soap) manufactured by Performance Additives
Processing aid (2): Sstructl WB16 (mixture of fatty acid ester and fatty acid metal salt) manufactured by Schill & Seilacher
Sulfur: HK-200-5 (5% oil-containing powder sulfur) manufactured by Hosoi Chemical Co., Ltd.
Vulcanization accelerator (1): Sunseller NS-G (N- (tert-butyl) -2-benzothiazolesulfenamide (TBBS)) manufactured by Sanshin Chemical Industry Co., Ltd.
Vulcanization accelerator (2): Sunseller TBZTD (tetrabenzylthiuram disulfide (TBzTD)) manufactured by Sanshin Chemical Industry Co., Ltd.
Vulcanization accelerator (3): Noxeller D (N, N′-diphenylguanidine) manufactured by Ouchi Shinsei Chemical Industry Co., Ltd.

Mercapto group activation ability determination test The reactivity of each rubber component used in Examples and Comparative Examples to mercapto groups (mercapto group activation ability index) was examined by the following procedure. 80 parts by mass of silica, 6.4 parts by mass of silane coupling agent A, and 35 parts by mass of oil are kneaded for 3 minutes with a 16 L B / B mixer with respect to 100 parts by mass of the rubber component, and kneaded at an exhaust temperature of 160 ° C. Was discharged. 1 kg of the obtained kneaded material was wound around an 8-inch open roll with a width of 30 cm and a thickness of 2 mm, and kneaded until the rubber temperature reached 95 ± 5 ° C. to obtain a rubber sheet. Thereafter, the obtained rubber sheet was cut, and the surface roughness Ra of the rubber fabric skin was measured with a surface roughness meter in accordance with the arithmetic average roughness Ra of JIS B 0601. About the value of the reciprocal of the obtained surface roughness, it represented by the index | exponent on the basis of the case of SBR1 like the following formula | equation. The larger the value, the smaller the surface roughness and the better the ability to activate mercapto groups.
(Mercapto group activation ability index)
= 100 × standard SBR1 surface roughness Ra / surface roughness Ra of each rubber component

Examples 1-9 and Comparative Examples 1-13
According to the blending contents shown in Table 1, 2 or 3, various chemicals shown in Step X1 were kneaded for 20 seconds with a 1.7 L Banbury mixer. Thereafter, various chemicals shown in Step X2 of Table 1, 2 or 3 were added and kneaded for 80 seconds, various chemicals shown in Step X3 of Table 1, 2 or 3 were added and further kneaded for 80 seconds, and the discharge temperature The kneaded material was discharged at 160 ° C. The obtained kneaded material was cooled to about 30 ° C. and then used in the next step.

  Next, according to the blending contents shown in step Y of Table 1, 2 or 3, other various chemicals were added to the obtained kneaded product, and kneaded at a discharge temperature of 150 ° C. for 2 minutes. The obtained kneaded material was cooled to about 30 ° C. and then used in the next step. Thereafter, sulfur and a vulcanization accelerator are added to the kneaded material obtained in the step Y according to the blending contents shown in the step F of Table 1, 2 or 3, and the condition of the discharge temperature of 125 ° C. using an open roll. Under kneading for 3 minutes, an unvulcanized rubber composition was obtained.

  Each obtained unvulcanized rubber composition was press vulcanized with a 2 mm thick mold at 170 ° C. for 12 minutes to obtain a vulcanized rubber composition.

  Further, the obtained unvulcanized rubber composition is formed into a tread shape, and bonded together with other tire members to form an unvulcanized tire (raw tire), and vulcanized at 165 ° C. for 15 minutes, A tire (tire size: 205 / 55R16) was manufactured.

  The processability of the unvulcanized rubber compositions obtained in Examples 1 to 9 and Comparative Examples 1 to 13 was evaluated by the following test. The results are shown in Tables 1-3.

<Workability (average surface roughness Ra)>
1 kg of unvulcanized rubber composition was wound around an 8-inch open roll with a width of 30 cm and a thickness of 2 mm, and kneaded until the rubber temperature reached 95 ± 5 ° C. to obtain a rubber sheet. Thereafter, the obtained rubber sheet was cut, and the surface roughness Ra of the rubber fabric skin was measured with a surface roughness meter in accordance with the arithmetic average roughness Ra of JIS B 0601. About the value of the reciprocal number of the obtained surface roughness, as for Examples 1-8, Comparative Examples 2-7, and Comparative Examples 10-13, the comparative example 1 was made into the reference | standard comparative example, and Example 9 and comparison were carried out as follows. For Example 9, Comparative Example 8 was used as a reference comparative example and indicated by an index. The larger the value, the smaller the surface roughness and the better the workability.

  (Workability index) = 100 × surface roughness Ra of reference comparative example / surface roughness Ra of each example

  From the results of Tables 1, 2 and 3, the first rubber component having a smaller activation ability with respect to mercapto groups in the rubber component (A) and the polysulfide compound are kneaded, and then a silane coupling having a mercapto group. In Examples 1 to 9, in which the agent was kneaded, and then the second rubber component of the rubber component (A) having a higher activation ability for mercapto groups than the first rubber component was kneaded, In comparison with Comparative Examples 1, 2 and 5-8, in which the rubber component (A) containing the rubber and the silane coupling agent having a mercapto group were used, and the rubber component (A) was kneaded simultaneously at the same time, It can also be seen that the workability is remarkably improved. In addition, the second rubber component having a higher activation ability for mercapto groups in the rubber component (A) is combined with a silane coupling having a mercapto group before the first rubber component having a smaller activation ability for mercapto groups. In Comparative Examples 3, 4, and 9 kneaded with the agent, the workability is further lowered as compared with Comparative Example 1 and Comparative Example 8. Then, after kneading the first rubber component having a smaller activation ability for mercapto groups with a silane coupling agent having a mercapto group, the polysulfide compound is kneaded, and then the second activation ability for mercapto groups is larger. It can be seen that in Comparative Example 10 in which the rubber component was kneaded, the workability tends to be slightly deteriorated as compared with Comparative Example 1. Then, a rubber component having a higher activation capability for mercapto groups and a polysulfide compound are kneaded, and then a rubber component having a lower activation capability for mercapto groups is used simultaneously with a silane coupling agent having a mercapto group or a mercapto group. In Comparative Examples 11 and 12, which were kneaded prior to the silane coupling agent having the above, the processability was slightly improved as compared to Comparative Example 1, but a remarkable improvement in workability as in Example 1 was observed. I understand that there is no.

Claims (7)

For tires containing a rubber component (A) containing at least two types of rubber components, a polysulfide compound (B) represented by the following formula (1) or (2), and a silane coupling agent (C) having a mercapto group A method for producing a rubber composition, comprising:
A step X1 of kneading the first rubber component of the rubber component (A) and the polysulfide compound (B);
The step X2 of adding the silane coupling agent (C) to the kneaded product obtained in the step X1 and kneading, and the second rubber component of the rubber component (A) to the kneaded product obtained in the step X2. Step X3 of adding and kneading
And a method for producing a rubber composition for tires, wherein the first rubber component has a smaller activation ability for mercapto groups than the second rubber component.

(In the formula, R ^1, same or different, .n representing a monovalent hydrocarbon group which may having 3 to 15 carbon atoms have a substituent is an integer of 2-6.)

(Wherein, R ² are the same or different, .m representing a divalent hydrocarbon group which may having 3 to 15 carbon atoms have a substituent is an integer of 2-6.) The manufacturing method according to claim 1, wherein the rubber component (A) contains 50% by mass or more of a diene rubber having a styrene content of 25 to 50% by mass and a vinyl bond content of 10 to 35% by mol. The method according to claim 2, wherein the styrene content is twice or more the vinyl bond amount. A silane coupling agent having a mercapto group is a compound represented by the following formula (3) and / or a binding unit A represented by the following formula (4) and a binding unit B represented by the following formula (5): The production method according to any one of claims 1 to 3, wherein the compound comprises:

(Wherein R ^{101 to} R ¹⁰³ represent a linear or branched alkyl group having 1 to 12 carbon atoms, a linear or branched alkoxy group having 1 to 12 carbon atoms, or —O— (R ¹¹¹ —O ) _z -R ¹¹² _(z pieces by R ¹¹¹ is .z pieces by R ¹¹¹ representing a divalent hydrocarbon group having 1 to 30 carbon atoms, straight chain or branched chain, may each be the same or different. R ¹¹² is a linear or branched alkyl group having 1 to 30 carbon atoms, a linear or branched alkenyl group having 2 to 30 carbon atoms, an aryl group having 6 to 30 carbon atoms, or a 7 to 30 carbon atom. Represents an aralkyl group, z represents an integer of 1 to 30.) R ^{101 to} R ¹⁰³ may be the same or different from each other, and R ¹⁰⁴ may be linear or branched. Represents an alkylene group having 1 to 6 carbon atoms.)

(In the formula, x is an integer of 0 or more, and y is an integer of 1 or more. R ²⁰¹ is a hydrogen atom, a halogen atom, a linear or branched alkyl group having 1 to 30 carbon atoms, a linear or branched chain. R ²⁰² represents an alkenyl group having 2 to 30 carbon atoms, a linear or branched alkynyl group having 2 to 30 carbon atoms, or a group in which a hydrogen atom at the terminal of the alkyl group is substituted with a hydroxyl group or a carboxyl group. Represents a linear or branched alkylene group having 1 to 30 carbon atoms, a linear or branched alkenylene group having 2 to 30 carbon atoms, or a linear or branched alkynylene group having 2 to 30 carbon atoms. R ²⁰¹ and R ²⁰² may form a ring structure.) A tire member is molded at a stage before vulcanization of the tire rubber composition obtained by the manufacturing method according to any one of claims 1 to 4, and a raw tire is molded in combination with another tire member. A tire manufacturing method comprising: a step and a vulcanizing step of vulcanizing the green tire obtained in the molding step. A tire component comprising a rubber component (A) containing at least two rubber components, a polysulfide compound (B) represented by the following formula (1) or (2), and a silane coupling agent (C) having a mercapto group A rubber composition comprising:
It is obtained by adding the silane coupling agent (C) to a kneaded product obtained by kneading the first rubber component of the rubber component (A) and the polysulfide compound (B), and then kneading. It is obtained by adding the second rubber component of the rubber component (A) to the kneaded product and kneading, and the activation capability of the first rubber component for mercapto groups is higher than that of the second rubber component. A rubber composition for tires that is small.

(In the formula, R ^1, same or different, .n representing a monovalent hydrocarbon group which may having 3 to 15 carbon atoms have a substituent is an integer of 2-6.)

(Wherein, R ² are the same or different, .m representing a divalent hydrocarbon group which may having 3 to 15 carbon atoms have a substituent is an integer of 2-6.) A tire provided with the member for tires comprised with the rubber composition for tires of Claim 6.