JP2017008241A - Rubber composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber composition providing a rubber crosslinked article excellent in low heat generating property and wet grip property for providing low fuel effect property and wet grip property in a tire of automobile.SOLUTION: There is provided a rubber composition containing a polymer represented by the formula (1) where a silicon-containing compound is added to a conjugated diene polymer terminal, and a silane coupling agent. The silicon-containing compound contains at least a nitrogen-containing group and further the silane coupling agent is a sulfide-based, mercapto-based, protected mercapto-based, vinyl-based, amino-based, glycidoxy-based, nitro-based or chloro-based silane coupling agent.SELECTED DRAWING: None

Description

  The present invention relates to a rubber composition containing a conjugated diene polymer, and more particularly, to provide a rubber cross-linked product that is excellent in low heat build-up and wet grip properties and that is suitably used for constituting a fuel-efficient tire. The present invention relates to a rubber composition.

  In recent years, automobile tires are strongly required to have low fuel consumption due to environmental problems and resource problems, while excellent wet grip properties are required from the viewpoint of safety. A crosslinked product of a rubber composition blended with silica as a filler is superior in low heat build-up compared to a crosslinked composition of a rubber composition blended with carbon black, and therefore rolling resistance when a tire is configured is reduced. Therefore, a tire excellent in fuel efficiency can be obtained by constituting a tire using a crosslinked product of a rubber composition containing silica.

  In such a rubber composition, in order to increase the affinity between rubber and silica, a technique for introducing a functional group having a high affinity for silica by reacting a modifier with the polymerization active terminal of the rubber is known. It has been.

  For example, as disclosed in Patent Document 1 and Patent Document 2, when a rubber polymer is obtained by a solution polymerization method, the rubber itself has an affinity for silica by reacting a modifier with an active terminal of the polymer. Technology that gives the potential is being studied. However, due to the recent increase in demand for low fuel consumption and wet grip properties for automobile tires, a rubber that can provide a rubber cross-linked product that is further excellent in low heat generation and excellent in wet grip properties is desired. ing.

JP-A-1-249812 JP 2003-171418 A

  The present invention has been made in view of such a situation, and an object of the present invention is to provide a rubber composition capable of providing a crosslinked rubber product having low heat build-up and excellent wet grip properties.

  As a result of diligent research to achieve the above object, the present inventors have found that a conjugated diene polymer chain having an active end is substituted with a tertiary amine structure-containing group at the 8-position as a modifier. -By reacting a compound having a dioxa-2-silacyclooctane structure, a silane coupling agent is added to a conjugated diene polymer in which a group having a specific structure is introduced at the end of the polymer chain. According to the resulting rubber composition, it was found that the rubber cross-linked product obtained by using the rubber composition was excellent in low heat build-up and wet grip properties, and completed the present invention.

（一般式（１）中、ｐｏｌｙｍｅｒは共役ジエン単量体単位を含んでなる重合体鎖を表し、Ｘ^１はヒドロカルビルオキシ基、ハロゲン基および水酸基から選択される官能基を表し、Ｒ^１は置換基を有していてもよい炭化水素基を表し、Ｒ^２およびＲ^３は、それぞれ、置換基を有していてもよい炭化水素基を表し、Ｒ^２およびＲ^３は互いに結合して、これらが結合する窒素原子とともに環構造を形成していてもよく、該環構造を形成する場合には、これらが結合する窒素原子に加えて、これらが結合する窒素原子以外のヘテロ原子とともに環構造を形成していてもよい。ｎは１〜３の整数であり、ｍは０〜２の整数であり、ｐは０〜２の整数であり、ｎ＋ｍ＋ｐ＝３である。）

（一般式（２）中、ｐｏｌｙｍｅｒは共役ジエン単量体単位を含んでなる重合体鎖を表し、Ｘ^２はヒドロカルビルオキシ基、ハロゲン基および水酸基から選択される官能基を表し、Ｒ^４は置換基を有していてもよい炭化水素基を表し、Ｒ^５およびＲ^６は、それぞれ、置換基を有していてもよい炭化水素基を表し、Ｒ^５およびＲ^６は互いに結合して、これらが結合する窒素原子とともに環構造を形成していてもよく、該環構造を形成する場合には、これらが結合する窒素原子に加えて、これらが結合する窒素原子以外のヘテロ原子とともに環構造を形成していてもよい。ｓは１または２であり、ｔは０または１であり、ｕは０または１であり、ｓ＋ｔ＋ｕ＝２である。） That is, according to the present invention, there is provided a rubber composition comprising a conjugated diene polymer represented by the following general formula (1) or the following general formula (2) and a silane coupling agent. Is done.

(In the general formula (1), polymer represents a polymer chain containing a conjugated diene monomer unit, X ¹ represents a functional group selected from a hydrocarbyloxy group, a halogen group and a hydroxyl group, and R ¹ represents a substituted group. represents a hydrocarbon group which may have a group, R ² and R ³ each represent a hydrocarbon group which may have a substituent, R ² and R ^3, taken together, these A ring structure may be formed together with the nitrogen atom to which these are bonded. (N is an integer of 1 to 3, m is an integer of 0 to 2, p is an integer of 0 to 2, and n + m + p = 3).

(In general formula (2), polymer represents a polymer chain comprising a conjugated diene monomer unit, X ² represents a functional group selected from a hydrocarbyloxy group, a halogen group and a hydroxyl group, and R ⁴ represents a substituted group. represents a hydrocarbon group which may have a group, R ⁵ and R ⁶ each represents a hydrocarbon group which may have a substituent, R ⁵ and R ^6, taken together, these A ring structure may be formed together with the nitrogen atom to which these are bonded. And s is 1 or 2, t is 0 or 1, u is 0 or 1, and s + t + u = 2.)

In the rubber composition of the present invention, the silane coupling agent is a sulfide-based, mercapto-based, protected mercapto-based, vinyl-based, amino-based, glycidoxy-based, nitro-based, or chloro-based silane coupling agent. preferable.
The rubber composition of the present invention preferably further contains 10 to 200 parts by weight of silica with respect to 100 parts by weight of the rubber component in the rubber composition.
The rubber composition of the present invention preferably further contains a crosslinking agent.

Moreover, according to this invention, the rubber crosslinked material formed by bridge | crosslinking said rubber composition is provided.
Furthermore, according to the present invention, there is provided a tire comprising the above rubber cross-linked product.

  ADVANTAGE OF THE INVENTION According to this invention, the rubber composition which can give the rubber crosslinked material excellent in the low exothermic property and wet grip property can be provided.

  The rubber composition of the present invention contains a conjugated diene polymer represented by the following general formula (1) or general formula (2) and a silane coupling agent.

（一般式（１）中、ｐｏｌｙｍｅｒは共役ジエン単量体単位を含んでなる重合体鎖を表し、Ｘ^１はヒドロカルビルオキシ基、ハロゲン基および水酸基から選択される官能基を表し、Ｒ^１は置換基を有していてもよい炭化水素基を表し、Ｒ^２およびＲ^３は、それぞれ、置換基を有していてもよい炭化水素基を表し、Ｒ^２およびＲ^３は互いに結合して、これらが結合する窒素原子とともに環構造を形成していてもよく、該環構造を形成する場合には、これらが結合する窒素原子に加えて、これらが結合する窒素原子以外のヘテロ原子とともに環構造を形成していてもよい。ｎは１〜３の整数であり、ｍは０〜２の整数であり、ｐは０〜２の整数であり、ｎ＋ｍ＋ｐ＝３である。）

（一般式（２）中、ｐｏｌｙｍｅｒは共役ジエン単量体単位を含んでなる重合体鎖を表し、Ｘ^２はヒドロカルビルオキシ基、ハロゲン基および水酸基から選択される官能基を表し、Ｒ^４は置換基を有していてもよい炭化水素基を表し、Ｒ^５およびＲ^６は、それぞれ、置換基を有していてもよい炭化水素基を表し、Ｒ^５およびＲ^６は互いに結合して、これらが結合する窒素原子とともに環構造を形成していてもよく、該環構造を形成する場合には、これらが結合する窒素原子に加えて、これらが結合する窒素原子以外のヘテロ原子とともに環構造を形成していてもよい。ｓは１または２であり、ｔは０または１であり、ｕは０または１であり、ｓ＋ｔ＋ｕ＝２である。） <Conjugated diene polymer>
First, the conjugated diene polymer used in the present invention will be described.
The conjugated diene polymer used in the present invention is represented by the following general formula (1) or the following general formula (2). The conjugated diene polymer used in the present invention may consist of only one represented by the following general formula (1), or only one represented by the following general formula (2). Or the mixture of what is represented by the following general formula (1) and what is represented by the following general formula (2) may be sufficient.

(In the general formula (1), polymer represents a polymer chain containing a conjugated diene monomer unit, X ¹ represents a functional group selected from a hydrocarbyloxy group, a halogen group and a hydroxyl group, and R ¹ represents a substituted group. represents a hydrocarbon group which may have a group, R ² and R ³ each represent a hydrocarbon group which may have a substituent, R ² and R ^3, taken together, these A ring structure may be formed together with the nitrogen atom to which is bonded, and in the case of forming the ring structure, in addition to the nitrogen atom to which they are bonded, the ring structure is combined with a hetero atom other than the nitrogen atom to which they are bonded. (N is an integer of 1 to 3, m is an integer of 0 to 2, p is an integer of 0 to 2, and n + m + p = 3).

(In general formula (2), polymer represents a polymer chain comprising a conjugated diene monomer unit, X ² represents a functional group selected from a hydrocarbyloxy group, a halogen group and a hydroxyl group, and R ⁴ represents a substituted group. represents a hydrocarbon group which may have a group, R ⁵ and R ⁶ each represents a hydrocarbon group which may have a substituent, R ⁵ and R ^6, taken together, these A ring structure may be formed together with the nitrogen atom to which these are bonded. And s is 1 or 2, t is 0 or 1, u is 0 or 1, and s + t + u = 2.)

  The polymer chain represented by “polymer” in the general formulas (1) and (2) is a polymer chain including a conjugated diene monomer unit. The conjugated diene compound used as a monomer for constituting the conjugated diene monomer unit is not particularly limited, but 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-phenyl -1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3-hexadiene, 4,5-diethyl-1,3-octadiene, 3-butyl-1,3-octadiene And so on. Of these, 1,3-butadiene and / or isoprene are preferred. These conjugated diene compounds may be used alone or in combination of two or more.

  The polymer chain represented by “polymer” in the general formulas (1) and (2) may be composed only of a conjugated diene monomer unit, but is a compound copolymerizable with a conjugated diene compound. It may further contain a unit consisting of Examples of the compound copolymerizable with the conjugated diene compound include styrene, methylstyrene, ethylstyrene, t-butylstyrene, α-methylstyrene, α-methyl-p-methylstyrene, chlorostyrene, bromostyrene, methoxystyrene, Aromatic vinyl compounds such as dimethylaminomethylstyrene, dimethylaminoethylstyrene, diethylaminomethylstyrene, diethylaminoethylstyrene, cyanoethylstyrene, vinylnaphthalene; chain olefin compounds such as ethylene, propylene, 1-butene; cyclopentene, 2-norbornene, etc. A non-conjugated diene compound such as 1,5-hexadiene, 1,6-heptadiene, 1,7-octadiene, dicyclopentadiene, 5-ethylidene-2-norbornene; (Meth) acrylic acid esters such as methyl (meth) acrylate, ethyl (meth) acrylate and butyl (meth) acrylate; other (meth) acrylic acid derivatives such as (meth) acrylonitrile and (meth) acrylamide; Is mentioned. Among these, aromatic vinyl compounds are preferable, and styrene is preferable among them. The compounds copolymerizable with these conjugated diene compounds may be used alone or in combination of two or more.

  In the polymer chain represented by “polymer” in the general formulas (1) and (2), the ratio of the conjugated diene monomer unit to the total monomer units constituting the polymer chain is Although not particularly limited, it is usually 30% by weight or more, preferably 40% by weight or more, and more preferably 50% by weight or more. Further, the content of vinyl bonds (1,2-vinyl bond and 3,4-vinyl bond) in the conjugated diene monomer unit portion of the polymer chain is not particularly limited, but is usually 1 to 90 mol%. , Preferably it is 5-85 mol%, More preferably, it is 10-80 mol%. Further, in this polymer chain, the ratio of the aromatic vinyl monomer unit to the total monomer units constituting the polymer chain is not particularly limited, but is usually 70% by weight or less, preferably It is 60% by weight or less, more preferably 50% by weight or less. In this polymer chain, the ratio of the monomer units other than the conjugated diene monomer unit and the aromatic vinyl monomer unit to the total monomer units constituting the polymer chain is also particularly limited. However, it is usually 20% by weight or less, preferably 10% by weight or less, and more preferably 5% by weight or less.

  When the polymer chain represented by “polymer” in the general formula (1) and the general formula (2) is composed of two or more types of monomer units, the bonding mode is, for example, a block shape or a taper. However, it is preferable to use a random binding mode. By making it random, the obtained rubber cross-linked product becomes superior due to its low heat build-up. In addition, the polymer chain represented by “polymer” in the general formula (1) and the general formula (2) is bonded to the silicon atom represented by “Si” in the general formula (1) and the general formula (2). The terminal on the side may be constituted by a polymer block consisting essentially only of isoprene units. By comprising a polymer block consisting essentially of isoprene units at the end, when silica is compounded in the rubber composition of the present invention, the affinity between the conjugated diene polymer and silica is improved, The resulting rubber cross-linked product can be made more excellent in low heat buildup and wear resistance.

  N in the general formula (1) (that is, the number of polymer chains bonded to the silicon atom represented by “Si” in the general formula (1)) is an integer of 1 to 3. The conjugated diene polymer used in the present invention may be composed only of those in which n in the general formula (1) is a specific numerical value, or a mixture of different n in the general formula (1). It may be.

  Further, s in the general formula (2) (that is, the number of polymer chains bonded to the silicon atom represented by “Si” in the general formula (2)) is 1 or 2. The conjugated diene polymer used in the present invention may be composed only of those in which s in the general formula (2) is a specific numerical value, or a mixture of different s in the general formula (2). It may be.

In General Formula (1) and General Formula (2), X ¹ and X ² represent a functional group selected from a hydrocarbyloxy group, a halogen group, and a hydroxyl group. The hydrocarbyloxy group that can be a functional group represented by X ¹ and X ² is not particularly limited, but is a methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, isobutoxy group, sec-butoxy group. Groups, alkoxy groups such as tert-butoxy group; alkenyloxy groups such as vinyloxy group and allyloxy group; aryloxy groups such as phenoxy group and naphthoxy group; aralkyloxy groups such as benzyloxy group; and the like. Among these, an alkoxy group or an aryloxy group is preferable, an alkoxy group is more preferable, and a methoxy group or an ethoxy group is particularly preferable. Further, the halogen group that can be X ¹ and X ² is not particularly limited, and examples thereof include a fluoro group, a chloro group, a bromo group, and an iodo group, and among these, a chloro group is preferable. X ¹ and X ² may be a hydroxyl group, and the hydroxyl group may be a hydrocarbyloxy group or a halogen group that has been hydrolyzed to become a hydroxyl group.

In the general formula (1) and general formula (2), when X ¹ and X ² contain an alkoxy group (that is, contains an alkoxysilyl group), the alkoxy group may It can be converted to a hydroxyl group by hydrolysis (ie, converted to a silanol group).

M in the general formula (1) (that is, the number of functional groups represented by X ¹ in the general formula (1)) is an integer of 0 to 2, and preferably 1 or 2. The conjugated diene polymer used in the present invention may be composed only of those in which m in the general formula (1) is a specific numerical value, or a mixture of different m in the general formula (1). It may be. In the case where m is 2, the functional groups represented by X ¹ in the general formula (1) contained in one molecule of the conjugated diene polymer may be the same or mutually It may be different.

Further, t in the general formula (2) (that is, the number of functional groups represented by X ² in the general formula (2)) is 0 or 1. The conjugated diene polymer of the present invention may be composed only of those in which t in the general formula (2) is a specific numerical value, or a mixture of different t in the general formula (2). There may be.

In General Formula (1) and General Formula (2), R ¹ and R ⁴ represent a hydrocarbon group which may have a substituent. Although it does not specifically limit as a hydrocarbon group which can become R < ¹ >, R < ⁴ >, a methyl group, an ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, etc. Alkyl groups such as vinyl group and allyl group; alkynyl groups such as ethynyl group and propynyl group; aryl groups such as phenyl group and naphthyl group; aralkyl groups such as benzyl group; Among these, an alkyl group or an aryl group is preferable, and an alkyl group is more preferable. Moreover, the hydrocarbon group represented by R ¹ and R ⁴ may have a substituent other than the hydrocarbon group, and the substituent is not particularly limited, but may be a carboxyl group, an acid anhydride group, Examples thereof include carbonyl group-containing groups such as hydrocarbylcarbonyl group, alkoxycarbonyl group and acyloxy group, epoxy group, oxy group, cyano group, amino group and halogen group.

P in the general formula (1) (that is, the number of groups represented by R ¹ in the general formula (1)) is an integer of 0 to 2, preferably 0 or 1. The conjugated diene polymer used in the present invention may consist only of those in which p in the general formula (1) is a specific numerical value, or a mixture of different p in the general formula (1). It may be. In the case where p is 2, the groups represented by R ¹ in the general formula (1) contained in one molecule of the conjugated diene polymer may be the same or different from each other. It may be a thing.

In general formula (2), u (that is, the number of groups represented by R ⁴ in general formula (2)) is 0 or 1. The conjugated diene polymer used in the present invention may be composed only of those in which u in the general formula (2) has a specific numerical value, or a mixture of different u in general formula (2). It may be.

In General Formula (1) and General Formula (2), R ² and R ³ , R ⁵ and R ⁶ each represents a hydrocarbon group which may have a substituent, and R ² and R ³ are bonded to each other. In addition, a ring structure may be formed together with the nitrogen atom to which they are bonded. Similarly, R ⁵ and R ⁶ may be bonded to each other to form a ring structure together with the nitrogen atom to which they are bonded. In addition, when these form a ring structure, in addition to the nitrogen atom to which they are bonded, the ring structure may be formed with a hetero atom other than the nitrogen atom to which they are bonded. When R ² and R ³ , R ⁵ and R ⁶ are not bonded to each other, the hydrocarbon group that can be R ² and R ³ , R ⁵ and R ⁶ is not particularly limited, but is a methyl group, an ethyl group, n- Alkyl groups such as propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group and tert-butyl group; alkenyl groups such as vinyl group and allyl group; alkynyl groups such as ethynyl group and propynyl group; phenyl group Aryl groups such as naphthyl group; aralkyl groups such as benzyl group; and the like. Among these, an alkyl group or an aryl group is preferable, an alkyl group is more preferable, and a methyl group or an ethyl group is particularly preferable. In addition, when R ² and R ³ , or R ⁵ and R ⁶ are bonded to each other to form a ring structure together with the nitrogen atom to which these are bonded, a divalent carbon formed by combining R ² and R ³ A hydrogen group or a divalent hydrocarbon group formed by bonding R ⁵ and R ⁶ is not particularly limited, but an n-butylene group (in the general formula (1) or the general formula (2), A 1-pyrrolidine group together with a nitrogen atom to be bonded), an n-pentylene group (when forming a 1-piperidine group), a butadienylene group (when forming a 1-pyrrole group), and the like.

In addition, the hydrocarbon group represented by R ² and R ³ , R ⁵ and R ⁶ may have a substituent other than the hydrocarbon group regardless of the presence or absence of the ring structure. Is not particularly limited, but includes carbonyl group-containing groups such as carboxyl group, acid anhydride group, hydrocarbylcarbonyl group, alkoxycarbonyl group, acyloxy group, epoxy group, oxy group, cyano group, amino group, halogen group, etc. be able to. Further, when R ² and R ³ , or R ⁵ and R ⁶ are bonded to each other to form a ring structure, the atoms forming the ring structure include carbon atoms, general formula (1), and general formula ( In 2), a hetero atom other than the nitrogen atom to which they are bonded may be contained, and examples of such a hetero atom include a nitrogen atom and an oxygen atom.

  In the general formula (1), n + m + p = 3. That is, the sum of n, m, and p in the general formula (1) is 3.

  In the general formula (2), s + t + u = 2. That is, the sum of s, t, and u in the general formula (2) is 2.

The conjugated diene polymer used in the present invention is particularly preferably a hydrocarbon group represented by R ² and R ³ , R ⁵ and R ⁶ , and a piperazine ring together with a nitrogen atom to which these are bonded. Those forming a structure are mentioned. More specifically, the conjugated diene polymer of the present invention is particularly preferably a conjugated diene polymer represented by the following general formula (3) or the following general formula (4). When the conjugated diene polymer used in the present invention has such a structure, the resulting rubber cross-linked product can be made particularly excellent in low heat build-up.

一般式（３）中、ｐｏｌｙｍｅｒ、Ｘ^１、Ｒ^１、ｎ、ｍ、およびｐは、いずれも、一般式（１）におけるものと同じものを表し、Ｒ^７は炭化水素基を表し、ｎ＋ｍ＋ｐ＝３である。

In general formula (3), polymer, X ¹ , R ¹ , n, m, and p all represent the same as in general formula (1), R ⁷ represents a hydrocarbon group, and n + m + p = 3.

一般式（４）中、ｐｏｌｙｍｅｒ、Ｘ^２、Ｒ^４、ｓ、ｔ、およびｕは、いずれも、一般式（２）におけるものと同じものを表し、Ｒ^８は炭化水素基を表し、ｓ＋ｔ＋ｕ＝２である。

In general formula (4), polymer, X ² , R ⁴ , s, t, and u all represent the same as in general formula (2), R ⁸ represents a hydrocarbon group, and s + t + u = 2.

R ⁷ and R ⁸ in general formula (3) and general formula (4) represent a hydrocarbon group. Although it does not specifically limit as a hydrocarbon group which can become R < ⁷ >, R < ⁸ >, a methyl group, an ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, etc. Alkyl groups such as vinyl group and allyl group; alkynyl groups such as ethynyl group and propynyl group; aryl groups such as phenyl group and naphthyl group; aralkyl groups such as benzyl group; Among these, an alkyl group or an aryl group is preferable, an alkyl group is more preferable, and a methyl group is particularly preferable.

  The weight average molecular weight (Mw) of the conjugated diene polymer used in the present invention is not particularly limited, but is usually 1,000 to 3,000,000, preferably as a value measured by gel permeation chromatography in terms of polystyrene. It is in the range of 10,000 to 2,000,000, more preferably 100,000 to 1,500,000. By setting the weight average molecular weight of the conjugated diene polymer within the above range, the balance between the workability and mechanical strength of the conjugated diene polymer is improved.

  Further, the molecular weight distribution represented by the ratio (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the conjugated diene polymer used in the present invention is not particularly limited, but preferably 1.0. It is -5.0, More preferably, it is 1.0-3.0. By setting the molecular weight distribution of the conjugated diene polymer in the above range, the resulting rubber cross-linked product is more excellent in low heat generation.

  Although it does not specifically limit as a method to manufacture the conjugated diene polymer (namely, conjugated diene polymer represented by General formula (1) or General formula (2)) used by this invention, For example, an inert solvent In the first step, a monomer containing a conjugated diene compound is polymerized using a polymerization initiator to obtain a conjugated diene polymer chain having an active end, and a conjugated diene heavy polymer having the active end. Examples include a production method including a second step of reacting a compound represented by the general formula (5), which will be described later, with the active end of the combined chain.

  In the first step, in order to obtain a conjugated diene polymer having an active end, the conjugated diene compound used as a monomer is the conjugated diene polymer used in the present invention (that is, the general formula (1) ) Or the conjugated diene polymer represented by the general formula (2)), the same examples as those exemplified as the conjugated diene compound used for constituting the polymer chain containing the conjugated diene monomer unit are exemplified. it can.

  Moreover, you may use an aromatic vinyl compound with a conjugated diene compound as a monomer. As the aromatic vinyl compound used as the monomer, in the conjugated diene polymer used in the present invention (that is, the conjugated diene polymer represented by the general formula (1) or the general formula (2)), The same thing as illustrated as an aromatic vinyl compound which can be used in order to comprise the polymer chain which comprises a conjugated diene monomer unit can be illustrated. Further, as the monomer, a compound copolymerizable with the conjugated diene compound other than the aromatic vinyl compound may be used together with the conjugated diene compound. As the compound copolymerizable with the conjugated diene compound other than the aromatic vinyl compound used as the monomer, the above-described conjugated diene polymer used in the present invention (that is, the general formula (1) or the general formula (2)). As a compound copolymerizable with a conjugated diene compound other than an aromatic vinyl compound, which can be used to constitute a polymer chain comprising a conjugated diene monomer unit. The same thing as illustrated can be illustrated.

  The inert solvent used for the polymerization is not particularly limited as long as it is one usually used in solution polymerization and does not inhibit the polymerization reaction. Specific examples of the inert solvent include chain aliphatic hydrocarbons such as butane, pentane, hexane, and heptane; alicyclic hydrocarbons such as cyclopentane and cyclohexane; aromatic hydrocarbons such as benzene, toluene, and xylene; Is mentioned. These inert solvents may be used individually by 1 type, and may be used in combination of 2 or more type. Although the usage-amount of an inert solvent is not specifically limited, It is the quantity from which a monomer concentration will be 1 to 50 weight%, for example, Preferably it will be 10 to 40 weight%.

  The polymerization initiator used for the polymerization is not particularly limited as long as it can polymerize a monomer containing a conjugated diene compound to give a conjugated diene polymer chain having an active end. Specific examples thereof include a polymerization initiator having an organic alkali metal compound, an organic alkaline earth metal compound, a lanthanum series metal compound, or the like as a main catalyst. Examples of the organic alkali metal compound include organic monolithium compounds such as n-butyllithium, sec-butyllithium, t-butyllithium, hexyllithium, phenyllithium and stilbenelithium; dilithiomethane, 1,4-dilithiobutane, 1,4 -Organic polyvalent lithium compounds such as dilithio-2-ethylcyclohexane, 1,3,5-trilithiobenzene, 1,3,5-tris (lithiomethyl) benzene; organic sodium compounds such as sodium naphthalene; organic such as potassium naphthalene Potassium compounds; and the like. Examples of the organic alkaline earth metal compound include di-n-butylmagnesium, di-n-hexylmagnesium, diethoxycalcium, calcium distearate, di-t-butoxystrontium, diethoxybarium, and diisopropoxybarium. , Diethyl mercaptobarium, di-t-butoxybarium, diphenoxybarium, diethylaminobarium, barium distearate, diketylbarium and the like. As a polymerization initiator having a lanthanum series metal compound as a main catalyst, for example, a lanthanum series metal comprising a lanthanum series metal such as lanthanum, cerium, praseodymium, neodymium, samarium, gadolinium, a carboxylic acid, and a phosphorus-containing organic acid And a polymerization initiator composed of this salt and a cocatalyst such as an alkylaluminum compound, an organoaluminum hydride compound, and an organoaluminum halide compound. Among these polymerization initiators, an organic monolithium compound and an organic polyvalent lithium compound are preferably used, an organic monolithium compound is more preferably used, and n-butyllithium is particularly preferably used. The organic alkali metal compound is used as an organic alkali metal amide compound by previously reacting with a secondary amine such as dibutylamine, dihexylamine, dibenzylamine, pyrrolidine, hexamethyleneimine, and heptamethyleneimine. Also good. These polymerization initiators may be used individually by 1 type, and may be used in combination of 2 or more type.

  The amount of the polymerization initiator used may be determined according to the molecular weight of the target conjugated diene polymer chain, but is usually 1 to 50 mmol, preferably 1.5 to 20 mmol, per 1000 g of monomer. Preferably it is the range of 2-15 mmol.

  The polymerization temperature is usually in the range of −80 to + 150 ° C., preferably 0 to 100 ° C., more preferably 30 to 90 ° C. As the polymerization mode, any of batch type and continuous type can be adopted. However, when copolymerizing a conjugated diene compound and an aromatic vinyl compound, a conjugated diene monomer unit and an aromatic vinyl monomer are used. The batch method is preferred because it is easy to control the randomness of the bond with the unit. As described above, the polymer chain represented by “polymer” in general formula (1) and general formula (2) is represented by “Si” in general formula (1) and general formula (2). In order to configure the terminal of the side bonded to the silicon atom with a polymer block consisting essentially only of isoprene units, the polymerization mode is set to batch, and first, other than the polymer block consisting only of isoprene units. After polymerizing the monomer for forming the part, before adding the compound represented by the general formula (5) described later to the polymerization reaction system, only isoprene is added as a monomer to the polymerization reaction system. And polymerization may be performed.

  In addition, when polymerizing a monomer comprising a conjugated diene compound, in order to adjust the vinyl bond content in the conjugated diene monomer unit in the resulting conjugated diene polymer chain, it is polar in an inert organic solvent. It is preferable to add a compound. Examples of the polar compound include ether compounds such as dibutyl ether and tetrahydrofuran; tertiary amines such as tetramethylethylenediamine; alkali metal alkoxides; phosphine compounds. Among these, ether compounds and tertiary amines are preferable, tertiary amines are more preferable, and tetramethylethylenediamine is particularly preferable. These polar compounds may be used individually by 1 type, and may be used in combination of 2 or more type. What is necessary is just to determine the usage-amount of a polar compound according to the vinyl bond content made into the objective, Preferably it is 0.001-100 mol with respect to 1 mol of polymerization initiators, More preferably, it is 0.01-10 mol. is there. When the amount of the polar compound used is within this range, it is easy to adjust the vinyl bond content in the conjugated diene monomer unit, and problems due to deactivation of the polymerization initiator hardly occur.

  According to the first step as described above, a conjugated diene polymer chain having an active end can be obtained in an inert solvent. Next, in the second step, the compound represented by the following general formula (5) is reacted with the active terminal of the conjugated diene polymer chain having the active terminal.

一般式（５）中、Ｘ^３はヒドロカルビルオキシ基、ハロゲン基および水酸基から選択される官能基を表し、Ｒ^９は置換基を有していてもよい炭化水素基を表し、Ｒ^１０およびＲ^１１は、それぞれ、置換基を有していてもよい炭化水素基を表し、Ｒ^１０およびＲ^１１は互いに結合して環構造を形成していてもよく、該環構造を形成する場合には、これらが結合する窒素原子に加えて、これらが結合する窒素原子以外のヘテロ原子とともに環構造を形成していてもよい。ｒは０〜２の整数である。

In the general formula (5), X ³ represents a functional group selected from a hydrocarbyloxy group, a halogen group and a hydroxyl group, R ⁹ represents a hydrocarbon group which may have a substituent, R ¹⁰ and R ¹¹ Each represents a hydrocarbon group which may have a substituent, and R ¹⁰ and R ¹¹ may be bonded to each other to form a ring structure, and in the case of forming the ring structure, In addition to the nitrogen atom to which is bonded, a ring structure may be formed together with a hetero atom other than the nitrogen atom to which these are bonded. r is an integer of 0-2.

In the general formula (5), X ³ represents a functional group selected from a hydrocarbyloxy group, a halogen group and a hydroxyl group. Specific examples of the functional group that can be the functional group represented by X ³ include the same examples as those exemplified as the functional groups that can be X ¹ and X ² in the general formula (1) and general formula (2). it can.

R in the general formula (5) (that is, the number of groups represented by X ³ in the general formula (5)) is an integer of 0 to 2. In the case where r in the general formula (5) is 2, the groups represented by X ³ contained in one molecule of the compound represented by the general formula (5) may be the same. May be different from each other.

In the general formula (5), R ⁹ represents a hydrocarbon group which may have a substituent. Specific examples of the hydrocarbon group and the substituent in the hydrocarbon group which may have a substituent represented by R ⁹ are R ¹ and R ⁴ in general formula (1) and general formula (2). The same thing as illustrated about the hydrocarbon group which may have a substituent which can be mentioned can be mentioned. In the case where r in the general formula (5) is 0, two groups represented by R ⁹ in the general formula (5) included in one molecule of the compound represented by the general formula (5) are the same. May be different or different from each other.

In the general formula (5), R ¹⁰ and R ¹¹ each represents a hydrocarbon group which may have a substituent, and R ¹⁰ and R ¹¹ are bonded to each other, and together with the nitrogen atom to which they are bonded, a ring structure In the case of forming the ring structure, in addition to the nitrogen atom to which they are bonded, the ring structure may be formed with a hetero atom other than the nitrogen atom to which they are bonded. Specific examples of the hydrocarbon group in the hydrocarbon group which may have a substituent represented by R ¹⁰ and R ¹¹ and the substituent include R ² in General Formula (1) and General Formula (2) and The same thing as what was illustrated about the hydrocarbon group which may have a substituent which can become R < ³ >, R < ⁵ > and R < ⁶ > can be mentioned.

一般式（６）中、Ｘ^３、Ｒ^９、およびｒは、いずれも、一般式（５）におけるものと同じものを表し、Ｒ^１２は炭化水素基を表す。 In order to obtain a conjugated diene polymer represented by general formula (3) or general formula (4), which is particularly preferable as the conjugated diene polymer used in the present invention, it is represented by general formula (5). A compound represented by the following general formula (6) may be used as the compound.

In general formula (6), X ³ , R ⁹ , and r all represent the same as in general formula (5), and R ¹² represents a hydrocarbon group.

R ¹² in the general formula (6) represents a hydrocarbon group. The hydrocarbon group that can be R ¹² is not particularly limited, but is an alkyl group such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, or a tert-butyl group. Alkenyl groups such as vinyl group and allyl group; alkynyl groups such as ethynyl group and propynyl group; aryl groups such as phenyl group and naphthyl group; aralkyl groups such as benzyl group; Among these, an alkyl group or an aryl group is preferable, an alkyl group is more preferable, and a methyl group is particularly preferable.

  Specific examples of the compound represented by the general formula (5) include 2,2-dimethoxy-8- (4-methylpiperazinyl) methyl-1,6-dioxa-2-silacyclooctane, 2,2- Diethoxy-8- (4-methylpiperazinyl) methyl-1,6-dioxa-2-silacyclooctane, 2,2-dimethoxy-8- (N, N-diethyl) methyl-1,6-dioxa-2 -Silacyclooctane, 2-methoxy-2-methyl-8- (4-methylpiperazinyl) methyl-1,6-dioxa-2-silacyclooctane and the like. One of these compounds represented by the general formula (5) may be used alone, or two or more thereof may be used in combination.

  Although the usage-amount of the compound represented by General formula (5) is not specifically limited, The quantity of the compound represented by General formula (5) with respect to 1 mol of active terminals of the conjugated diene type polymer chain which has the active terminal made to react. As, it is preferable that it is 0.5-10.0 mol, It is more preferable that it is 0.7-5.0 mol, It is especially preferable that it is 1.0-2.0 mol. By using the compound represented by the general formula (5) in such an amount, the rubber composition using the resulting conjugated diene polymer gives a rubber cross-linked product particularly excellent in low heat build-up. Become.

  In general, when the compound represented by the general formula (5) reacts with the active end of the conjugated diene polymer chain having the active end, the reaction is considered to proceed as follows. That is, first, the first reaction form is illustrated. As a first step reaction, the oxygen-silicon bond in the 8-membered ring structure in the compound represented by the general formula (5) is cleaved, and the silicon atom is A new bond is formed between the active end of the conjugated diene polymer chain, and the oxygen atom is derived from the counter ion of the active end and a salt structure (Note that this salt structure is derived from the polymerization reaction terminator when the polymerization reaction is stopped) React with protons to form hydroxyl groups). Furthermore, when the compound represented by the general formula (5) has a hydrocarbyloxysilyl group (when r in the general formula (5) is 1 or 2), the hydrocarbyloxy group in the hydrocarbyloxysilyl group And the active end of the conjugated diene polymer chain react, and further, a bond is formed between the silicon atom and the active end of the conjugated diene polymer chain.

Alternatively, as the second reaction form, in the first-stage reaction, the oxygen-silicon bond in the 8-membered ring structure in the compound represented by the general formula (5) is bonded to the silicon atom without cleavage. , X ³ is desorbed to form a new bond between the silicon atom and the active end of the conjugated diene polymer chain, and the oxygen atom forms a salt structure with the counter ion at the active end (this salt The structure forms a hydroxyl group by reacting with protons derived from a polymerization reaction terminator or the like when the polymerization reaction is stopped). Furthermore, when the compound represented by the general formula (5) has a hydrocarbyloxysilyl group (when r in the general formula (5) is 1 or 2), the hydrocarbyloxy group in the hydrocarbyloxysilyl group And the active end of the conjugated diene polymer chain react, and further, a bond is formed between the silicon atom and the active end of the conjugated diene polymer chain.

  The reaction proceeds according to the first reaction form, whereby the conjugated diene polymer represented by the general formula (1) can be obtained, while the reaction proceeds according to the second reaction form. Thus, a conjugated diene polymer represented by the general formula (2) can be obtained. In addition, the reaction according to the first reaction form and the reaction according to the second reaction form proceed simultaneously (for example, while the reaction proceeds mainly according to the first reaction form, 2), a mixture of a compound represented by the general formula (1) and a compound represented by the following general formula (2) can be obtained as a conjugated diene polymer. it can.

  The method of reacting the compound represented by the general formula (5) with the conjugated diene polymer chain having an active end is not particularly limited, but there are methods of mixing these in a solvent in which each of them can be dissolved. Can be mentioned. As the solvent used in this case, those exemplified as the inert solvent used in the polymerization described above can be used. In this case, the method of adding the compound represented by the general formula (5) to the polymerization solution used for the polymerization for obtaining a conjugated diene polymer chain having an active end is simple and preferable. In this case, the compound represented by the general formula (5) is preferably dissolved in an inert solvent and added to the polymerization system, and the solution concentration is in the range of 1 to 50% by weight. It is preferable. Although reaction temperature is not specifically limited, Usually, it is 0-120 degreeC, Reaction time is also not specifically limited, Usually, it is 1 minute-1 hour.

  The timing of adding the compound represented by the general formula (5) to the solution containing the conjugated diene polymer chain having an active end is not particularly limited, but the polymerization reaction is not completed and the conjugate having an active end is present. The state in which the solution containing a diene polymer chain also contains a monomer, more specifically, the solution containing a conjugated diene polymer chain having an active end is 100 ppm or more, more preferably 300 It is desirable to add the compound represented by the general formula (5) to this solution in a state containing ˜50,000 ppm of monomer. By adding the compound represented by the general formula (5) in this way, side reactions between the conjugated diene polymer chain having an active terminal and impurities contained in the polymerization system are suppressed, and the reaction is performed. It becomes possible to control well.

  In addition, the conjugated diene polymer chain having the active terminal remains in the state before the compound represented by the general formula (5) is reacted with the conjugated diene polymer chain having the active terminal or after the reaction. In the state where the effect of the present invention is not inhibited, a part of the active terminus of the conjugated diene polymer chain having an active terminus is used as a coupling agent or a modifier that has been conventionally used. May be added to the polymerization system for coupling or modification.

一般式（７）中、Ｒ^１３は置換基を有していてもよいアルキル鎖を表し、Ｘ^４はハロゲン基を表し、Ｍは珪素原子または錫原子を表す。 Examples of the coupling agent used in this case include tin halide, silicon halide, and a compound represented by the following general formula (7).

In the general formula (7), R ¹³ represents an alkyl chain which may have a substituent, X ⁴ represents a halogen group, and M represents a silicon atom or a tin atom.

  Examples of tin halides include tin tetrachloride and triphenylmonochlorotin, with tin tetrachloride being preferred. Examples of the silicon halide include silicon tetrachloride, hexachlorodisilane, triphenoxychlorosilane, methyltriphenoxysilane, and diphenoxydichlorosilane, with silicon tetrachloride being preferred.

In the general formula (7), R ¹³ represents a hydrocarbon group which may have a substituent, and the hydrocarbon group that can be R ¹³ is not particularly limited, but includes a methylene group, 1,2-ethylene. Group, 1,3-propylene group, 1,4-butylene group, 1,5-pentylene group, 1,6-hexylene group, 4-methyl-2,2-pentylene group, 2,3-dimethyl-2,3 -Butylene group etc. are mentioned. Among these, 1,2-ethylene group and 1,6-hexylene group are preferable. In addition, the halogen group that can be X ⁴ is not particularly limited, and examples thereof include a fluoro group, a chloro group, a bromo group, and an iodo group, and among these, a chloro group is preferable. Furthermore, although M is a silicon atom or a tin atom, it is preferably a silicon atom.

  Specific examples of the compound represented by the general formula (7) include bis (trichlorosilyl) methane, 1,2-bis (trichlorosilyl) ethane, 1,3-bis (trichlorosilyl) propane, 1,4. -Bis (trichlorosilyl) butane, 1,5-bis (trichlorosilyl) pentane, 1,6-bis (trichlorosilyl) hexane and the like.

  In the method for producing a conjugated diene polymer of the present invention, the amount of tin halide, silicon halide, or the compound represented by the general formula (7) is not particularly limited, but the conjugated diene heavy polymer having an active terminal is not limited. The amount per 1 mol of the active terminal of the combined chain is preferably 0.001 to 0.2 mol, more preferably 0.005 to 0.1 mol, and 0.01 to 0.05 mol. It is particularly preferred. By using the tin halide, the silicon halide, or the compound represented by the general formula (7) in such an amount, the shape stability of the resulting conjugated diene polymer can be further improved.

  About the conjugated diene polymer chain having an active end, an unreacted active end remains after reacting the compound represented by the general formula (5) and, if desired, a coupling agent or other modifier. If present, it is preferable to deactivate the unreacted active terminal by adding a polymerization terminator such as alcohol such as methanol, ethanol, isopropanol or water to the polymerization solution.

  If desired, an anti-aging agent such as a phenol stabilizer, a phosphorus stabilizer, or a sulfur stabilizer may be added to the solution of the conjugated diene polymer obtained as described above. What is necessary is just to determine suitably the addition amount of an anti-aging agent according to the kind etc. Furthermore, if desired, an extension oil may be blended to form an oil-extended rubber. Examples of extender oils include paraffinic, aromatic and naphthenic petroleum softeners, plant softeners, and fatty acids. When using a petroleum softener, it is preferable that the content of polycyclic aromatics extracted by the method of IP346 (the inspection method of THE INSTITUTE PETROLEUM in the UK) is less than 3%. When using extending oil, the usage-amount is 5-100 weight part normally with respect to 100 weight part of conjugated diene polymers.

The conjugated diene polymer thus obtained can be obtained as a solid conjugated diene polymer by separating it from the reaction mixture, for example, by removing the solvent by steam stripping. it can. In addition, when the conjugated diene polymer obtained by the polymerization reaction has a hydrocarbyloxy group or a halogen group as the group represented by X ¹ or X ² in the general formula (1) or (2), When this conjugated diene polymer is subjected to steam stripping, at least a part of these groups may be hydrolyzed to generate a hydroxyl group. As a group represented by X ¹ and X ² thus generated, a hydroxyl group ( The conjugated diene polymer having a silanol group can also be a conjugated diene polymer used in the present invention (that is, a conjugated diene polymer represented by the general formula (1) or the general formula (2)). .

  The coupling rate of the conjugated diene polymer used in the present invention (that is, the conjugated diene polymer represented by the general formula (1) or (2)) is not particularly limited, but is preferably 10% by weight or more. More preferably, it is 15% by weight or more, particularly preferably 20% by weight or more, and preferably 80% by weight or less, more preferably 75% by weight or less, particularly preferably 70% by weight or less. When the coupling ratio is in the above range, the rubber cross-linked product obtained by cross-linking the rubber composition containing such a conjugated diene polymer may be excellent in mechanical strength and wear resistance. it can. The coupling rate is 1.8 times the peak top molecular weight of the conjugated diene polymer chain having an active terminal before reacting with the compound represented by the general formula (5) and the coupling agent or other modifier. It is the weight fraction of the polymer molecule having the above molecular weight with respect to the total amount of the finally obtained conjugated diene polymer, and the measurement of the molecular weight at this time is obtained as a polystyrene equivalent molecular weight by gel permeation chromatography. To do.

<Silane coupling agent>
The rubber composition of the present invention contains a silane coupling agent in addition to the conjugated diene polymer represented by the above general formula (1) or general formula (2). In addition to the conjugated diene polymer represented by the general formula (1) or the general formula (2) described above, a low heat generation property and wet grip property of the conjugated diene polymer can be obtained by blending a silane coupling agent. The improvement effect can be further enhanced.

  The silane coupling agent is not particularly limited, and various silane coupling agents can be used. In the present invention, sulfide-based, mercapto-based, protected mercapto-based, vinyl-based, amino-based, glycidoxy-based, A nitro or chloro silane coupling agent can be preferably used. Among them, a vulcanized structure can be formed with the conjugated diene polymer represented by the general formula (1) or the general formula (2) described above, thereby further improving the low heat buildup and wet grip properties. From the viewpoint of being able to produce a sulfite, mercapto or protected mercapto silane coupling agent. Moreover, a silane coupling agent may be used individually by 1 type, and may use 2 or more types together.

  Examples of the sulfide-based silane coupling agent include a silane coupling agent having a sulfide group and a hydrolyzable group. Examples of the hydrolyzable group include an alkoxy group, a phenoxy group, a carboxyl group, and an alkenyloxy group. Among these, an alkoxy group is preferable from the viewpoint that the dispersibility when blending a compounding agent such as silica is more excellent. When the hydrolyzable group is an alkoxy group, the alkoxy group preferably has 1 to 16 carbon atoms, more preferably 1 to 4 carbon atoms. Examples of the alkoxy group having 1 to 4 carbon atoms include a methoxy group, an ethoxy group, and a propoxy group.

Moreover, it is preferable that a sulfide type silane coupling agent is equipped with the bivalent organic group (henceforth a sulfide group containing organic group) containing the sulfide group represented by following General formula (8).
_{- (CH 2) γ -S β} - (CH 2) γ - (8)
In general formula (8), β represents an integer of 1 to 10, and is preferably an integer of 2 to 4. Moreover, in general formula (8), (gamma) represents the integer of 1-6 and it is preferable that it is an integer of 2-4.

Specific examples of the group represented by the general formula (8) include, for example, —CH ₂ —S ₂ —CH ₂ —, —C ₂ H ₄ —S ₂ —C ₂ H ₄ —, —C ₃ H ₆ —. _{S 3 -C 3 H 6 -,} - C 4 H 8 -S 2 -C 4 H 8 -, - CH 2 -S 4 -CH 2 -, - C 2 H 4 -S 4 -C 2 H 4 -, _{-C 3 H 6 -S 4 -C 3} H 6 -, - C 4 H 8 -S 4 -C 4 H 8 - , and the like.

  Examples of the sulfide-based silane coupling agent include bis (3-triethoxysilylpropyl) tetrasulfide, bis (2-triethoxysilylethyl) tetrasulfide, bis (3-triethoxysilylethyl) tetrasulfide, and bis ( 3-triethoxysilylpropyl) disulfide, bis (2-triethoxysilylethyl) disulfide and the like. Among these, bis (3-triethoxysilylpropyl) tetrasulfide and bis (3-triethoxysilylpropyl) disulfide are more preferable.

  Examples of the mercapto silane coupling agent include a silane coupling agent having a mercapto group and a hydrolyzable group. Examples of the hydrolyzable group include an alkoxy group, a phenoxy group, a carboxyl group, and an alkenyloxy group. Among these, an alkoxy group is preferable from the viewpoint that the dispersibility when blending a compounding agent such as silica is more excellent. When the hydrolyzable group is an alkoxy group, the alkoxy group preferably has 1 to 16 carbon atoms, more preferably 1 to 4 carbon atoms. Examples of the alkoxy group having 1 to 4 carbon atoms include a methoxy group, an ethoxy group, and a propoxy group.

  Among such mercapto silane coupling agents, mercapto silane coupling agents having a polyether chain and mercapto silane coupling agents having a polysiloxane structure (—Si—O—) are preferred.

The mercapto-based silane coupling agent having a polyether chain may be any one having a polyether chain, specifically, a side chain having two or more ether bonds, and specific examples thereof include, for example, -R ¹⁴ A side chain having a total of two or more structural units represented by —O—R ¹⁵ — can be mentioned. Here, in the above structural units, R ¹⁴ and R ¹⁵ are each independently a linear or branched alkylene group, a linear or branched alkenylene group, a linear or branched alkynylene group, Alternatively, it represents a substituted or unsubstituted arylene group. Of these, a linear alkylene group is preferable.

上記一般式（９）中、Ｒ^１６は、炭素数１〜８のアルコキシ基を表し、なかでも、炭素数１〜３のアルコキシ基が好ましい。炭素数１〜３のアルコキシ基としては、たとえば、メトキシ基、エトキシ基などが挙げられる。また、上記一般式（９）中、ａは１または２であり、１であることが好ましい。なお、ａが２である場合の複数あるＲ^１６はそれぞれ同一であっても異なっていてもよい。 As the mercapto-based silane coupling agent having such a polyether chain, a compound represented by the following general formula (9) can be suitably used.

In the general formula (9), R ¹⁶ represents an alkoxy group having 1 to 8 carbon atoms, and among them, an alkoxy group having 1 to 3 carbon atoms is preferable. Examples of the alkoxy group having 1 to 3 carbon atoms include a methoxy group and an ethoxy group. In the general formula (9), a is 1 or 2, and is preferably 1. A plurality of R ¹⁶ when a is 2 may be the same or different.

In the general formula (9), R ¹⁷ represents a linear polyether group having 4 to 30 carbon atoms. The polyether group is a group having two or more ether bonds. Specific examples thereof include a group having two or more structural units represented by —R ¹⁴ —O—R ¹⁵ — in total. It is done. R ¹⁴ and R ¹⁵ are the same as in the case of the mercapto silane coupling agent having a polyether chain described above. Moreover, in the said General formula (9), b is 1 or 2, and it is preferable that it is 2. A plurality of R ¹⁷ in the case where b is 2 may be the same or different.
Constituting R ^17, as the linear polyether group having 4-30 carbon atoms, a group represented by the following general formula (10) are preferred.

In General Formula (10), R ²⁰ represents a linear alkyl group, a linear alkenyl group, or a linear alkynyl group, and among them, a linear alkyl group is preferable. As the linear alkyl group, a linear alkyl group having 1 to 20 carbon atoms is preferable, and a linear alkyl group having 8 to 15 carbon atoms is more preferable. Specific examples of the linear alkyl group having 8 to 15 carbon atoms include octyl group, nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group and the like, and tridecyl group is particularly preferable.

In the general formula (10), R ²¹ represents a linear alkylene group, a linear alkenylene group, or a linear alkynylene group, and among them, a linear alkylene group is preferable. As the linear alkylene group, a linear alkylene group having 1 to 2 carbon atoms is preferable, and an ethylene group is more preferable. In said general formula (10), d represents the integer of 1-10, Preferably it is an integer of 3-7.

In General Formula (9), R ¹⁸ represents a hydrogen atom or an alkyl group having 1 to 8 carbon atoms. In the general formula (9), c is 0 or 1, preferably 0.

In General Formula (9), R ¹⁹ represents an alkylene group having 1 to 30 carbon atoms, among which an alkylene group having 1 to 12 carbon atoms is preferable, and an alkylene group having 1 to 5 carbon atoms is more preferable. Specific examples of the alkylene group having 1 to 5 carbon atoms include a methylene group, an ethylene group, and a propylene group.

  In the general formula (9), a, b, and c satisfy the relationship of a + b + c = 3 in addition to the above-described range.

The mercapto-based silane coupling agent having a polysiloxane structure may be any one having a polysiloxane structure (—S i—O—), and is represented by an average composition formula represented by the following general formula (11). Are preferred.
(A ¹ ) _e (A ² ) _f (A ³ ) _g (A ⁴ ) _h (R ²² ) _i SiO _{(4-2e-f-g-h-i) / 2} (11)

In the general formula (11), A ¹ represents a divalent organic group containing a sulfide group (hereinafter also referred to as a sulfide group-containing organic group), and is a group represented by the following general formula (12). It is preferable.
_{- (CH 2) j -S k} - (CH 2) j - (12)
In general formula (12), j represents an integer of 1 to 10, and is preferably an integer of 2 to 4. Moreover, in general formula (12), k represents the integer of 1-6 and it is preferable that it is an integer of 2-4.

Specific examples of the group represented by the general formula (12) include, for example, —CH ₂ —S ₂ —CH ₂ —, —C ₂ H ₄ —S ₂ —C ₂ H ₄ —, —C ₃ H ₆ —. _{S 3 -C 3 H 6 -,} - C 4 H 8 -S 2 -C 4 H 8 -, - CH 2 -S 4 -CH 2 -, - C 2 H 4 -S 4 -C 2 H 4 -, _{-C 3 H 6 -S 4 -C 3} H 6 -, - C 4 H 8 -S 4 -C 4 H 8 - , and the like.

In General Formula (11), A ² represents a monovalent hydrocarbon group having 5 to 10 carbon atoms, and specific examples thereof include a hexyl group, an octyl group, and a decyl group.

In the general formula (11), A ³ represents a hydrolyzable group, and specific examples thereof include an alkoxy group, a phenoxy group, a carboxyl group, an alkenyloxy group, and the like. It is preferable that it is group represented.
-OR ²³ (13)
In the general formula ^{(13), R 23} is an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 10 carbon atoms, an aralkyl group (aryl alkyl group) or an alkenyl group having 2 to 10 carbon atoms having from 6 to 10 carbon atoms In particular, an alkyl group having 1 to 5 carbon atoms is preferable. Specific examples of the alkyl group having 1 to 20 carbon atoms include methyl group, ethyl group, propyl group, butyl group, hexyl group, octyl group, decyl group, octadecyl group and the like. Specific examples of the aryl group having 6 to 10 carbon atoms include a phenyl group and a tolyl group. Specific examples of the aralkyl group having 6 to 10 carbon atoms include a benzyl group and a phenylethyl group. Specific examples of the alkenyl group having 2 to 10 carbon atoms include a vinyl group, a propenyl group, and a pentenyl group.

In the general formula (11), A ⁴ represents an organic group containing a mercapto group, and among them, a group represented by the following general formula (14) is preferable.
_{- (CH 2) l -SH (} 14)
In general formula (14), l represents an integer of 1 to 10, and is preferably an integer of 1 to 5.

Specific examples of the group represented by the general formula _{(14), -CH 2 SH,} -C 2 H 4 SH, -C 3 H 6 SH, -C 4 H 8 SH, -C 5 H 10 SH, - _{C 6 H 12 SH, -C 7} H 14 SH, -C 8 H 16 SH, -C 9 H 18 SH, and the like -C _{10 H} 20 SH.

In the general formula (11), R ²² represents a monovalent hydrocarbon group having 1 to 4 carbon atoms.

  In general formula (11), e, f, g, h, and i are 0 ≦ e <1, 0 ≦ f <1, 0 <g <3, 0 <h <1, 0 ≦ i <2, 0 <2e + f + g + h + i <4 (however, one of e and f is not 0). From the viewpoint that the scorch resistance of the rubber composition can be improved, e is preferably 0 <e <1, and more preferably 0 <e ≦ 0.50. Further, f is preferably 0 <f <1, more preferably 0.10 ≦ f ≦ 0.89, from the viewpoint that low heat build-up and wet grip properties can be further improved, and g Is preferably 1.2 ≦ g ≦ 2.0, and h is preferably 0.1 ≦ h ≦ 0.8.

Among the mercapto-based silane coupling agents having a polysiloxane structure represented by the general formula (11), the dispersibility when compounding a compounding agent such as silica can be made better. A ¹ is a group represented by the general formula (12), A ³ is a group represented by the general formula (13), and A ⁴ is a group represented by the general formula (14) Is more preferable.

  The molecular weight of the mercapto-based silane coupling agent having a polysiloxane structure represented by the general formula (11) is determined using toluene as a solvent from the viewpoint of scorch resistance and dispersibility when compounding agents such as silica are blended. The weight average molecular weight determined in terms of polystyrene by gel permeation chromatography (GPC) is preferably in the range of 500 to 2,300, more preferably in the range of 600 to 1,500.

  The mercapto equivalent of the mercapto-based silane coupling agent having a polysiloxane structure represented by the general formula (11) by the titration method of acetic acid / potassium iodide / potassium iodate added-sodium thiosulfate solution is the general formula (1) or From the viewpoint of excellent vulcanization reactivity with respect to the conjugated diene polymer represented by the formula (2), it is preferably 550 to 1900 g / mol, more preferably 600 to 1500 g / mol.

  The skeleton of the mercapto silane coupling agent having a polysiloxane structure represented by the general formula (11) preferably has no metal other than a silicon atom (for example, Sn, Ti, Al).

  A mercapto-based silane coupling agent having a polysiloxane structure represented by the general formula (11) is, for example, as a first production method, an organosilicon compound represented by the following general formula (16) and the following general formula ( It can be produced by a method of hydrolytic condensation with the organosilicon compound represented by 17). Alternatively, as a second production method, an organosilicon compound represented by the following general formula (15), an organosilicon compound represented by the following general formula (16), and an organic represented by the following general formula (17) The method of hydrolytic condensation with a silicon compound is mentioned. Furthermore, as a third production method, an organosilicon compound represented by the following general formula (15), an organosilicon compound represented by the following general formula (16), and an organic represented by the following general formula (17) A method of hydrolyzing and condensing a silicon compound and an organosilicon compound represented by the following general formula (18) is mentioned. Among these, the second method is preferable.

In the general formula (15), R ²⁴ represents an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 10 carbon atoms, or an alkenyl group having 2 to 10 carbon atoms, and in particular, an alkyl group having 1 to 5 carbon atoms. It is preferable that Specific examples of the alkyl group having 1 to 20 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, a decyl group, and an octadecyl group. Specific examples of the aryl group having 6 to 10 carbon atoms include a phenyl group, a tolyl group, and a naphthyl group. Specific examples of the alkenyl group having 2 to 10 carbon atoms include a vinyl group, a propenyl group, and a pentenyl group.
In General Formula (15), R ²⁵ represents an alkyl group having 1 to 10 carbon atoms or an aryl group having 6 to 10 carbon atoms. Specific examples of the alkyl group having 1 to 10 carbon atoms include a methyl group, an ethyl group, a propyl group, a butyl group, a hexyl group, an octyl group, and a decyl group. Specific examples of the aryl group having 6 to 10 carbon atoms are the same as R ²⁴ above.
In general formula (15), j and k are the same as j and k in general formula (12). Moreover, v represents the integer of 1-3 in general formula (15).

  Specific examples of the organosilicon compound represented by the general formula (15) include bis (trimethoxysilylpropyl) tetrasulfide, bis (triethoxysilylpropyl) tetrasulfide, bis (trimethoxysilylpropyl) disulfide, bis (tri And ethoxysilylpropyl) disulfide.

In the general formula (16), R ²⁶ is the same as R ^{24 in the} general formula (15), and R ²⁷ is the same as R ^{25 in the} general formula (15).
Moreover, in the said General formula (16), w is the same as that of v of the said General formula (15), and x represents the integer of 5-10.

  Specific examples of the organosilicon compound represented by the general formula (16) include, for example, pentyltrimethoxysilane, pentylmethyldimethoxysilane, pentyltriethoxysilane, pentylmethyldiethoxysilane, hexyltrimethoxysilane, and hexylmethyldimethoxy. Silane, hexyltriethoxysilane, hexylmethyldiethoxysilane, octyltrimethoxysilane, octylmethyldimethoxysilane, octyltriethoxysilane, octylmethyldiethoxysilane, decyltrimethoxysilane, decylmethyldimethoxysilane, decyltriethoxysilane, decyl And methyldiethoxysilane.

In general formula (17), R ²⁸ is the same as R ²⁴ in general formula (15), and R ²⁹ is the same as R ^{25 in} general formula (15).
In general formula (17), y is the same as v in general formula (15), and l is the same as l in general formula (14).

  Specific examples of the organosilicon compound represented by the general formula (17) include α-mercaptomethyltrimethoxysilane, α-mercaptomethylmethyldimethoxysilane, α-mercaptomethyltriethoxysilane, and α-mercaptomethylmethyldiethoxy. Examples thereof include silane, γ-mercaptopropyltrimethoxysilane, γ-mercaptopropylmethyldimethoxysilane, γ-mercaptopropyltriethoxysilane, and γ-mercaptopropylmethyldiethoxysilane.

In general formula (18), R ³⁰ is the same as R ²⁴ in general formula (15), and R ³¹ is the same as R ^{25 in} general formula (15).
Moreover, in General formula (18), z is the same as that of v of General formula (15), (alpha) represents the integer of 1-4.

  Specific examples of the organosilicon compound represented by the general formula (18) include, for example, methyltrimethoxysilane, dimethyldimethoxysilane, methyltriethoxysilane, methylethyldiethoxysilane, propyltrimethoxysilane, propylmethyldimethoxysilane, Examples thereof include propylmethyldiethoxysilane.

  When producing a mercapto-based silane coupling agent having a polysiloxane structure represented by the general formula (11), a solvent may be used as necessary. Examples of the solvent include, but are not limited to, aliphatic hydrocarbon solvents such as pentane, hexane, heptane, and decane, ether solvents such as diethyl ether, tetrahydrofuran, and 1,4-dioxane, formamide, dimethylformamide, and N-methyl. Examples thereof include amide solvents such as pyrrolidone, aromatic hydrocarbon solvents such as benzene, toluene and xylene, and alcohol solvents such as methanol, ethanol and propanol.

  Moreover, when manufacturing the mercapto type | system | group silane coupling agent which has a polysiloxane structure represented by General formula (11), you may use a catalyst as needed. The catalyst is not particularly limited, but specifically, acidic catalysts such as hydrochloric acid and acetic acid, Lewis acid catalysts such as tetrabutyl orthotitanate and ammonium fluoride, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium acetate, potassium acetate And alkali metal salts such as sodium hydrogen carbonate, potassium carbonate, potassium hydrogen carbonate, calcium carbonate, sodium methoxide and sodium ethoxide, and amine compounds such as triethylamine, tributylamine, pyridine and 4-dimethylaminopyridine.

  Moreover, as an organosilicon compound used when producing a mercapto-based silane coupling agent having a polysiloxane structure represented by the general formula (11), a silane coupling agent having a mercapto group (for example, the general formula (17) And a silane coupling agent other than a silane coupling agent having a sulfide group or a mercapto group (for example, an organic silicon compound represented by general formula (16) or general formula (18)), and In combination with a silane coupling agent having a mercapto group and a silane coupling agent other than a silane coupling agent having a sulfide group or a mercapto group, the silane coupling agent having a mercapto group / Silane coupling agents other than silane coupling agents having sulfide groups or mercapto groups The molar ratio of the “ringing agent” is preferably in the range of 1.1 / 8.9 to 6.7 / 3.3, and preferably in the range of 1.4 / 8.6 to 5.0 / 5.0. It is more preferable.

  Furthermore, as an organosilicon compound used for producing a mercapto-based silane coupling agent having a polysiloxane structure represented by the general formula (11), a silane coupling agent having a mercapto group (for example, the general formula (17) When a silane coupling agent having a sulfide group (for example, an organosilicon compound represented by the general formula (15)) is used in combination, a silane coupling agent having a mercapto group and a sulfide are used. The mixing ratio with the silane coupling agent having a group is 2.0 / 8.0 to 8.9 / 1 in terms of a molar ratio of “silane coupling agent having a mercapto group / silane coupling agent having a sulfide group”. 0.1 is preferable, and 2.5 / 7.5 to 8.0 / 2.0 is more preferable.

  Moreover, as an organosilicon compound used when producing a mercapto-based silane coupling agent having a polysiloxane structure represented by the general formula (11), a silane coupling agent having a mercapto group (for example, the general formula (17) Silane other than a silane coupling agent having a sulfide group or a mercapto group, and a silane coupling agent having a sulfide group (for example, an organosilicon compound represented by the general formula (15)). When using together with a coupling agent (for example, the organosilicon compound represented by General formula (16) and General formula (18)), the usage-amount of the silane coupling agent which has a mercapto group is in these total amount. It is preferable to set it as the range of 10.0-73.0 mol%. Further, the amount of the silane coupling agent having a sulfide group is preferably in the range of 5.0 to 67.0 mol% in the total amount thereof, other than the silane coupling agent having a sulfide group or a mercapto group. The amount of the silane coupling agent used is preferably in the range of 16.0 to 85.0 mol% in the total amount.

一般式（１９）中、Ｒ^３２は、Ｒ^３７Ｏ−、Ｒ^３７Ｃ（＝Ｏ）Ｏ−、Ｒ^３７Ｒ^３８Ｃ＝ＮＯ−、Ｒ^３７Ｒ^３８ＣＮＯ−、Ｒ^３７Ｒ^３８Ｎ−、または、−（ＯＳｉＲ^３７Ｒ^３８）_ζ（ＯＳｉＲ^３７Ｒ^３８Ｒ^３９）（ただし、Ｒ^３７、Ｒ^３８、Ｒ^３９は、それぞれ独立に水素原子または炭素数１〜１８の一価の炭化水素基であり、ζは１〜５の整数。）、Ｒ^３３は、Ｒ^１と同様のもの、または、水素原子または炭素数１〜１８の一価の炭化水素基、Ｒ^３４はＲ^１、Ｒ^２と同様のもの、または−［Ｏ（Ｒ^４０Ｏ）_ηＨ］基（ただし、Ｒ^４０は炭素数１〜１８のアルキレン基、ηは１〜４の整数である。）、Ｒ^３５は炭素数１〜１８の二価の炭化水素基、Ｒ^３６は炭素数１〜１８の一価の炭化水素基を示し、δ、εは、０≦δ≦３、０≦ε≦２、２≦δ＋ε≦３の関係を満たす数である。 The protected mercapto-based silane coupling agent is not particularly limited as long as it has a protected mercapto group. For example, a compound represented by the following general formula (19) can be preferably used.

In the general formula ^{(19), R 32 is, R 37 O-, R 37 C} (= O) O-, R 37 R 38 C = NO-, R 37 R 38 CNO-, R 37 R 38 N-, or , — (OSiR ³⁷ R ³⁸ ) _ζ (OSiR ³⁷ R ³⁸ R ³⁹ ) (where R ³⁷ , R ³⁸ , and R ³⁹ are each independently a hydrogen atom or a monovalent hydrocarbon group having 1 to 18 carbon atoms) , Ζ is an integer of 1 to 5.), R ³³ is the same as R ¹ , or a hydrogen atom or a monovalent hydrocarbon group having 1 to 18 carbon atoms, R ³⁴ is the same as R ¹ and R ² Or — [O (R ⁴⁰ O) _η H] group (where R ⁴⁰ is an alkylene group having 1 to 18 carbon atoms, η is an integer of 1 to 4), and R ³⁵ is 1 to 18 divalent hydrocarbon ^{group, R 36} represents a monovalent hydrocarbon group having 1 to 18 carbon atoms, [delta], epsilon is Is a number satisfying the relationship ≦ δ ≦ 3,0 ≦ ε ≦ 2,2 ≦ δ + ε ≦ 3.

  In the general formula (19), examples of the monovalent hydrocarbon group having 1 to 18 carbon atoms include an alkyl group having 1 to 18 carbon atoms, an alkenyl group having 2 to 18 carbon atoms, and an aryl group having 6 to 18 carbon atoms. And an aralkyl group having 7 to 18 carbon atoms. Here, the alkyl group and alkenyl group may be linear, branched or cyclic, and the aryl group and aralkyl group have a substituent such as a lower alkyl group on the aromatic ring. Also good.

 Specific examples of the monovalent hydrocarbon group having 1 to 18 carbon atoms include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, Pentyl, hexyl, octyl, decyl, dodecyl, cyclopentyl, cyclohexyl, vinyl, propenyl, allyl, hexenyl, octenyl, cyclopentenyl, cyclohexenyl, phenyl, tolyl Group, xylyl group, naphthyl group, benzyl group, phenethyl group, naphthylmethyl group and the like.

In general formula (19), the alkylene group having 1 to 18 carbon atoms represented by R ⁴⁰ may be linear, branched or cyclic, but is preferably linear. Examples of the linear alkylene group include methylene group, ethylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group, octamethylene group, decamethylene group, dodecamethylene group and the like.

In the general formula (19), examples of the divalent hydrocarbon group having 1 to 18 carbon atoms represented by R ³⁵ include an alkylene group having 1 to 18 carbon atoms, an alkenylene group having 2 to 18 carbon atoms, and a carbon number. Examples thereof include a cycloalkylene group having 5 to 18 carbon atoms, a cycloalkylalkylene group having 6 to 18 carbon atoms, an arylene group having 6 to 18 carbon atoms, and an aralkylene group having 7 to 18 carbon atoms. The alkylene group and alkenylene group may be linear or branched, and the cycloalkylene group, cycloalkylalkylene group, arylene group and aralkylene group have a substituent such as a lower alkyl group on the ring. It may be. As R ³⁵ , an alkylene group having 1 to 6 carbon atoms is preferable, and a linear alkylene group such as a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, or a hexamethylene group is particularly preferable. be able to.

  Specific examples of the protected mercapto silane coupling agent include 3-hexanoylthiopropyltriethoxysilane, 3-octanoylthiopropyltriethoxysilane, 3-decanoylthiopropyltriethoxysilane, and 3-lauroylthiopropyltri Ethoxysilane, 2-hexanoylthioethyltriethoxysilane, 2-octanoylthioethyltriethoxysilane, 2-decanoylthioethyltriethoxysilane, 2-lauroylthioethyltriethoxysilane, 3-hexanoylthiopropyltrimethoxy Silane, 3-octanoylthiopropyltrimethoxysilane, 3-decanoylthiopropyltrimethoxysilane, 3-lauroylthiopropyltrimethoxysilane, 2-hexanoylthioethyltrimethoxysilane, 2-octane Neu Lucio ethyltrimethoxysilane, 2- deca Neu thio ethyltrimethoxysilane, and the like of 2-lauroyl thio ethyltrimethoxysilane.

  Examples of vinyl silane coupling agents include vinyltrimethoxysilane, vinyltriethoxysilane, and vinyltris (2-methoxyethoxy) silane.

  Examples of amino silane coupling agents include 3-aminopropyltriethoxysilane, 3-aminopropyltrimethoxysilane, 3- (2-aminoethyl) aminopropyltriethoxysilane, and 3- (2-aminoethyl). Examples include aminopropyltrimethoxysilane.

  Examples of glycidoxy-based silane coupling agents include γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, and γ-glycidoxypropylmethyl. Examples include dimethoxysilane.

  Examples of the nitro silane coupling agent include 3-nitropropyltrimethoxysilane and 3-nitropropyltriethoxysilane.

  Examples of the chloro-based silane coupling agent include 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 2-chloroethyltrimethoxysilane, and 2-chloroethyltriethoxysilane.

  The compounding amount of the silane coupling agent in the rubber composition of the present invention is preferably 0.1 to 30 parts by weight, more preferably 0.5 to 20 parts per 100 parts by weight of the rubber component in the rubber composition. Parts by weight, more preferably 1 to 10 parts by weight. By making the compounding quantity of a silane coupling agent into the said range, the abrasion resistance and low heat build-up of the rubber crosslinked material obtained will become more excellent.

  The addition form of the silane coupling agent in the rubber composition of the present invention is not particularly limited. For example, when silica is compounded as a compounding agent, the silane coupling agent is preliminarily added to the silica. It is good also as a form which adds to the conjugated diene type | system | group polymer represented by General formula (1) or General formula (2) mentioned above with a silica in the state which performs surface treatment by silica, and exists in the surface of a silica. . Or of course, it is good also as a form which adds a silane coupling agent as it is.

The rubber composition of the present invention preferably further contains silica. Examples of the silica used in the present invention include dry method white carbon, wet method white carbon, colloidal silica, and precipitated silica. Among these, wet method white carbon mainly containing hydrous silicic acid is preferable. Alternatively, a carbon-silica dual phase filler in which silica is supported on the carbon black surface may be used. These silicas can be used alone or in combination of two or more. The nitrogen adsorption specific surface area (measured by the BET method according to ASTM D3037-81) of the silica used is preferably 50 to 300 m ² / g, more preferably 80 to 220 m ² / g, and particularly preferably 100. -170 m < ² > / g. Moreover, it is preferable that the pH of a silica is 5-10.

  The amount of silica in the rubber composition of the present invention is preferably 10 to 200 parts by weight, more preferably 30 to 150 parts by weight, and still more preferably based on 100 parts by weight of the rubber component in the rubber composition. Is 50 to 100 parts by weight. By making the blending amount of silica within this range, the processability of the rubber composition will be excellent, and the resulting rubber cross-linked product will be more excellent in wear resistance and low heat build-up.

  The rubber composition of the present invention may further contain carbon black such as furnace black, acetylene black, thermal black, channel black, and graphite. Among these, furnace black is preferable. These carbon blacks can be used alone or in combination of two or more. The compounding amount of carbon black is usually 120 parts by weight or less with respect to 100 parts by weight of the rubber component in the rubber composition.

  The method of adding silica to the rubber composition of the present invention is not particularly limited, and is a method of adding and kneading a solid rubber component (dry kneading method) or a solution of a rubber component and coagulating. A drying method (wet kneading method) or the like can be applied.

  Moreover, it is preferable that the rubber composition of the present invention further contains a crosslinking agent. Examples of the crosslinking agent include sulfur-containing compounds such as sulfur and sulfur halides, organic peroxides, quinonedioximes, organic polyvalent amine compounds, and alkylphenol resins having a methylol group. Among these, sulfur is preferably used. The amount of the crosslinking agent is preferably 0.1 to 15 parts by weight, more preferably 0.5 to 5 parts by weight, particularly preferably 1 to 100 parts by weight of the rubber component in the rubber composition. ~ 4 parts by weight.

  Further, in addition to the above components, the rubber composition of the present invention includes a crosslinking accelerator, a crosslinking activator, an anti-aging agent, a filler (excluding silica and carbon black), an activator, and a process oil in accordance with conventional methods. , Plasticizers, lubricants, tackifiers and the like can be blended in the required amounts.

  When sulfur or a sulfur-containing compound is used as the crosslinking agent, it is preferable to use a crosslinking accelerator and a crosslinking activator in combination. Examples of the crosslinking accelerator include sulfenamide-based crosslinking accelerators; guanidine-based crosslinking accelerators; thiourea-based crosslinking accelerators; thiazole-based crosslinking accelerators; thiuram-based crosslinking accelerators; dithiocarbamic acid-based crosslinking accelerators; A crosslinking accelerator; and the like. Among these, those containing a sulfenamide-based crosslinking accelerator are preferable. These crosslinking accelerators are used alone or in combination of two or more. The amount of the crosslinking accelerator is preferably 0.1 to 15 parts by weight, more preferably 0.5 to 5 parts by weight, particularly preferably 100 parts by weight of the rubber component in the rubber composition. 1 to 4 parts by weight.

  Examples of the crosslinking activator include higher fatty acids such as stearic acid; zinc oxide. These crosslinking activators are used alone or in combination of two or more. The compounding amount of the crosslinking activator is preferably 0.05 to 20 parts by weight, particularly preferably 0.5 to 15 parts by weight with respect to 100 parts by weight of the rubber component in the rubber composition.

  Moreover, you may mix | blend rubbers other than the conjugated diene polymer represented by the general formula (1) or the general formula (2) described above with the rubber composition of the present invention. Examples of other rubbers include natural rubber, polyisoprene rubber, emulsion polymerization styrene-butadiene copolymer rubber, solution polymerization styrene-butadiene copolymer rubber, and polybutadiene rubber (high cis-BR and low cis BR may be used. Further, it may be a polybutadiene rubber containing crystal fibers made of 1,2-polybutadiene polymer.), Styrene-isoprene copolymer rubber, butadiene-isoprene copolymer rubber, styrene-isoprene-butadiene copolymer rubber, acrylonitrile- Among butadiene copolymer rubbers and acrylonitrile-styrene-butadiene copolymer rubbers, those other than the above-described modified conjugated diene rubbers. Among these, natural rubber, polyisoprene rubber, polybutadiene rubber, and solution-polymerized styrene-butadiene copolymer rubber are preferable. These rubbers can be used alone or in combination of two or more.

  In the rubber composition of the present invention, the conjugated diene polymer represented by the general formula (1) or the general formula (2) preferably accounts for 10 to 100% by weight of the rubber component in the rubber composition. 50 to 100% by weight is particularly preferable. In such a ratio, the rubber component having the lower heat buildup and wear resistance can be obtained by including the conjugated diene polymer represented by the general formula (1) or the general formula (2) in the rubber component. A crosslinked product can be obtained.

  In order to obtain the rubber composition of the present invention, each component may be kneaded according to a conventional method. For example, after kneading a rubber component and a component excluding a thermally unstable component such as a crosslinking agent and a crosslinking accelerator. The desired rubber composition can be obtained by mixing the kneaded product with a thermally unstable component such as a crosslinking agent or a crosslinking accelerator. The kneading temperature of the component excluding the heat unstable component and the rubber component is preferably 80 to 00 ° C, more preferably 120 to 180 ° C, and the kneading time is preferably 30 seconds to 30 minutes. is there. The kneaded product and the thermally unstable component are usually mixed after cooling to 100 ° C. or lower, preferably 80 ° C. or lower.

  The rubber cross-linked product of the present invention is obtained by cross-linking the rubber composition of the present invention as described above. The rubber cross-linked product of the present invention uses the rubber composition of the present invention, for example, is molded by a molding machine corresponding to a desired shape, for example, an extruder, an injection molding machine, a compressor, a roll, and heated. Can be produced by carrying out a crosslinking reaction and fixing the shape as a crosslinked product. In this case, crosslinking may be performed after molding in advance, or crosslinking may be performed simultaneously with molding. The molding temperature is usually 10 to 200 ° C, preferably 25 to 120 ° C. The crosslinking temperature is usually 100 to 200 ° C., preferably 130 to 190 ° C., and the crosslinking time is usually 1 minute to 24 hours, preferably 2 minutes to 12 hours, particularly preferably 3 minutes to 6 hours.

  Further, depending on the shape and size of the rubber cross-linked product, even if the surface is cross-linked, it may not be sufficiently cross-linked to the inside. Therefore, secondary cross-linking may be performed by heating.

  As a heating method for crosslinking the rubber composition, a general method used for crosslinking of rubber such as press heating, steam heating, oven heating, hot air heating and the like may be appropriately selected.

  For example, since the rubber cross-linked product of the present invention obtained as described above is obtained by using the rubber composition of the present invention described above, it has excellent low heat buildup and wet grip properties. The rubber cross-linked product of the present invention makes use of such characteristics, and for example, in tires, materials for various parts of the tire such as cap treads, base treads, carcass, sidewalls, bead portions; Other various industrial materials; resin impact resistance improvers; resin film buffers; shoe soles; rubber shoes; golf balls; toys; In particular, since the rubber cross-linked product of the present invention is excellent in low heat build-up and wet grip properties, it can be suitably used as a tire material, particularly a low fuel consumption tire material, and is optimal for tread applications.

Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. In the examples, “parts” and “%” are based on weight unless otherwise specified.
Various measurements and evaluations were performed according to the following methods.

[Molecular weight of conjugated diene polymer]
The molecular weight of the polymer was determined as a polystyrene-equivalent molecular weight by gel permeation chromatography. Specific measurement conditions were as follows.
Measuring instrument: High-performance liquid chromatograph (trade name “HLC-8220” manufactured by Tosoh Corporation)
Column: Tosoh Corporation, product name "GMH-HR-H" was connected in series.
Detector: Differential refractometer Eluent: Tetrahydrofuran Column temperature: 40 ° C

[Coupling rate of conjugated diene polymer]
In the elution curve obtained by gel permeation chromatography under the above conditions, the area ratio of the peak portion having a peak top molecular weight of 1.8 times or more of the peak top molecular weight indicated by the smallest peak of molecular weight relative to the total elution area, The coupling rate of the conjugated diene polymer was taken as the value.

[Low heat build-up of rubber cross-linked product]
Regarding the low exothermic property of the rubber cross-linked product, a test piece having a length of 50 mm, a width of 12.7 mm, and a thickness of 2 mm was used at 60 ° C. under conditions of dynamic strain of 2.5% and 10 Hz using ARES manufactured by Rheometrics. Evaluation was made by measuring tan δ. The value of tan δ is indicated by an index with the measured value of Comparative Example 1 being 100. The smaller this index, the better the low heat buildup.

[Wet grip properties of rubber cross-linked products]
Regarding the wet grip properties of the rubber cross-linked product, a test piece having a length of 50 mm, a width of 12.7 mm, and a thickness of 2 mm was used at 0 ° C. under the conditions of dynamic strain of 0.5% and 10 Hz using ARES manufactured by Rheometrics. Evaluation was made by measuring the value of tan δ. The value of tan δ is indicated by an index with the measured value of Comparative Example 1 being 100. The larger this index, the better the wet grip.

[Production Example 1]
In a nitrogen atmosphere, 800 parts of cyclohexane, 94.8 parts of 1,3-butadiene, 25.2 parts of styrene, and 0.164 parts of tetramethylethylenediamine were added to an autoclave, and then 0.045 part of n-butyllithium was added. Then, polymerization was started at 60 ° C. The polymerization reaction was continued for 60 minutes, and after confirming that the polymerization conversion was in the range of 95% to 100%, 2,2-dimethoxy-8- (4-methylpiperazinyl) methyl-1,6 -After adding 0.322 part of dioxa-2-silacyclooctane and making it react for 30 minutes, 0.064 part of methanol was added as a polymerization terminator, and the solution containing a conjugated diene type polymer was obtained. Then, 2,4-bis [(octylthio) methyl] -o-cresol (trade name “Irganox 1520” manufactured by Ciba Specialty Chemicals Co., Ltd.) as an anti-aging agent was added to 100 parts of the obtained polymer component. After adding 15 parts to the solution, the solvent was removed by steam stripping, followed by vacuum drying at 60 ° C. for 24 hours to obtain a solid conjugated diene polymer (A1). The obtained conjugated diene polymer (A1) had a weight average molecular weight (Mw) of 370,000, a molecular weight distribution (Mw / Mn) of 1.29, and a coupling rate of 32.8%.

[Production Example 2]
Instead of 0.322 part of 2,2-dimethoxy-8- (4-methylpiperazinyl) methyl-1,6-dioxa-2-silacyclooctane, 2,2-dimethoxy-1-phenyl-1-aza A solid conjugated diene polymer (A2) was obtained in the same manner as in Production Example 1 except that 0.236 parts of -2-silacyclopentane was used. The obtained conjugated diene polymer (A2) had a weight average molecular weight (Mw) of 258,000, a molecular weight distribution (Mw / Mn) of 1.12 and a coupling rate of 4.5%.

[Production Example 3]
Instead of 0.322 part of 2,2-dimethoxy-8- (4-methylpiperazinyl) methyl-1,6-dioxa-2-silacyclooctane, 0.188 part of N-phenyl-2-pyrrolidone was used. A solid conjugated diene polymer (A3) was obtained in the same manner as in Production Example 1, except that it was. The conjugated diene polymer (A3) obtained had a weight average molecular weight (Mw) of 255,000, a molecular weight distribution (Mw / Mn) of 1.08, and a coupling rate of 2.2%.

[Example 1]
In a Brabender-type mixer with a capacity of 250 ml, 70 parts of the conjugated diene polymer (A1) obtained in Production Example 1 and 30 parts of butadiene rubber (trade name “Nipol BR1220” manufactured by Nippon Zeon Co., Ltd.) are kneaded for 30 seconds. Then, 50 parts of silica (made by Rhodia, trade name “Zeosil 1165MP”, nitrogen adsorption specific surface area (BET method): 163 m ² / g)), process oil (made by Nippon Oil Corporation, trade name “Aromax T-DAE”) )) And 20 parts of a silane coupling agent: 6 parts of bis (3- (triethoxysilyl) propyl) tetrasulfide (trade name “Si69” manufactured by Degussa Co., Ltd.) After kneading for 5 minutes, 25 parts of silica (trade name “Zeosil 1165MP”, manufactured by Rhodia), 3 parts of zinc oxide, stearic acid 2 parts and an anti-aging agent: 2 parts of N-phenyl-N ′-(1,3-dimethylbutyl) -p-phenylenediamine (trade name “NOCRACK 6C” manufactured by Ouchi Shinsei Co., Ltd.) are further added. The mixture was kneaded for 5 minutes, and the kneaded product was discharged from the mixer. The temperature of the kneaded product at the end of kneading was 150 ° C. After the kneaded product was cooled to room temperature, it was kneaded again in a Brabender type mixer at 110 ° C. for 2 minutes, and then the kneaded product was discharged from the mixer. Next, with an open roll at 50 ° C., the obtained kneaded product was mixed with 1.40 parts of sulfur, a crosslinking accelerator: N-tert-butyl-2-benzothiazolylsulfenamide (trade name “Noxeller NS-P”, After adding 1.2 parts of Ouchi Shinsei Chemical Co., Ltd.) and 1.2 parts of diphenylguanidine (trade name “Noxeller D”, Ouchi Shinsei Chemical Co., Ltd.) and kneading them, a sheet-like rubber composition The thing was taken out. This rubber composition was press-crosslinked at 160 ° C. for 20 minutes to produce a rubber cross-linked test piece. The test piece was evaluated for low heat build-up and wet grip. The results are shown in Table 1.

[Example 2]
As a silane coupling agent, instead of 6 parts of bis (3- (triethoxysilyl) propyl) tetrasulfide, 6 parts of 3-octanoylthio-1-propyltriethoxysilane (GE Toshiba Silicone Co., Ltd., “NXT silane”) Except that they were used, test pieces of rubber composition and rubber cross-linked product were prepared in the same manner as in Example 1 and evaluated in the same manner. The results are shown in Table 1.

Example 3
As a silane coupling agent, instead of 6 parts of bis (3- (triethoxysilyl) propyl) tetrasulfide, 6 parts of bis (3- (triethoxysilyl) propyl) disulfide (trade name “Si75” manufactured by Degussa) Except that was used, a rubber composition and a cross-linked rubber test piece were prepared in the same manner as in Example 1 and evaluated in the same manner. The results are shown in Table 1.

[Comparative Example 1]
In the same manner as in Example 1, except that 70 parts of the conjugated diene polymer (A2) obtained in Production Example 2 was used instead of 70 parts of the conjugated diene polymer (A1) obtained in Production Example 1. Then, test pieces of rubber composition and rubber cross-linked product were prepared and evaluated in the same manner. The results are shown in Table 1.

[Comparative Example 2]
In the same manner as in Example 2, except that 70 parts of the conjugated diene polymer (A2) obtained in Production Example 2 was used instead of 70 parts of the conjugated diene polymer (A1) obtained in Production Example 1. Then, test pieces of rubber composition and rubber cross-linked product were prepared and evaluated in the same manner. The results are shown in Table 1.

[Comparative Example 3]
In the same manner as in Example 3, except that 70 parts of the conjugated diene polymer (A2) obtained in Production Example 2 was used instead of 70 parts of the conjugated diene polymer (A1) obtained in Production Example 1. Then, test pieces of rubber composition and rubber cross-linked product were prepared and evaluated in the same manner. The results are shown in Table 1.

[Comparative Example 4]
In the same manner as in Example 1, except that 70 parts of the conjugated diene polymer (A3) obtained in Production Example 3 was used instead of 70 parts of the conjugated diene polymer (A1) obtained in Production Example 1. Then, test pieces of rubber composition and rubber cross-linked product were prepared and evaluated in the same manner. The results are shown in Table 1.

[Comparative Example 5]
In the same manner as in Example 2, except that 70 parts of the conjugated diene polymer (A3) obtained in Production Example 3 was used instead of 70 parts of the conjugated diene polymer (A1) obtained in Production Example 1. Then, test pieces of rubber composition and rubber cross-linked product were prepared and evaluated in the same manner. The results are shown in Table 1.

[Comparative Example 6]
In the same manner as in Example 3, except that 70 parts of the conjugated diene polymer (A3) obtained in Production Example 3 was used instead of 70 parts of the conjugated diene polymer (A1) obtained in Production Example 1. Then, test pieces of rubber composition and rubber cross-linked product were prepared and evaluated in the same manner. The results are shown in Table 1.

  As can be seen from Table 1, the rubber composition containing the conjugated diene polymer represented by the general formula (1) or the general formula (2) obtained by the manufacturing method described above and a silane coupling agent. The rubber cross-linked products obtained using (Examples 1 to 3) were obtained using rubber compositions (Comparative Examples 1 to 6) using conjugated diene polymers that were terminal-modified with different modifiers. Compared to the obtained rubber cross-linked product, it is excellent in low heat generation and wet grip.

Claims (6)

A rubber composition comprising a conjugated diene polymer represented by the following general formula (1) or the following general formula (2) and a silane coupling agent.

(In the general formula (1), polymer represents a polymer chain containing a conjugated diene monomer unit, X ¹ represents a functional group selected from a hydrocarbyloxy group, a halogen group and a hydroxyl group, and R ¹ represents a substituted group. represents a hydrocarbon group which may have a group, R ² and R ³ each represent a hydrocarbon group which may have a substituent, R ² and R ^3, taken together, these A ring structure may be formed together with the nitrogen atom to which these are bonded. (N is an integer of 1 to 3, m is an integer of 0 to 2, p is an integer of 0 to 2, and n + m + p = 3).

(In general formula (2), polymer represents a polymer chain comprising a conjugated diene monomer unit, X ² represents a functional group selected from a hydrocarbyloxy group, a halogen group and a hydroxyl group, and R ⁴ represents a substituted group. represents a hydrocarbon group which may have a group, R ⁵ and R ⁶ each represents a hydrocarbon group which may have a substituent, R ⁵ and R ^6, taken together, these A ring structure may be formed together with the nitrogen atom to which these are bonded. And s is 1 or 2, t is 0 or 1, u is 0 or 1, and s + t + u = 2.)   The rubber composition according to claim 1, wherein the silane coupling agent is a sulfide-based, mercapto-based, protected mercapto-based, vinyl-based, amino-based, glycidoxy-based, nitro-based, or chloro-based silane coupling agent.   The rubber composition according to claim 1 or 2, further comprising 10 to 200 parts by weight of silica with respect to 100 parts by weight of the rubber component in the rubber composition.   The rubber composition according to any one of claims 1 to 3, further comprising a crosslinking agent.   A crosslinked rubber product obtained by crosslinking the rubber composition according to claim 4.   A tire comprising the rubber cross-linked product according to claim 5.