JP2013018812A - Rubber composition and pneumatic tire - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rubber composition that can improve fuel efficiency, wet grip performance, wear resistance, and rubber strength in a well-balanced manner, and to provide a pneumatic tire using the rubber composition.SOLUTION: The rubber composition includes a rubber component, silica, and a bisdithio compound of 1,2-bis(N, N'-dibenzyl thiocarbamoyl dithio)ethane or the like. In 100 mass% of the rubber component, the content of a conjugated diene polymer that includes a structural unit based on a conjugated diene and a structural unit derived from nitrogen-containing group-substituted vinyl silane, and in which at least one terminal of the polymer is modified by an alkoxy group-containing tertiary amine compound of an N,N-dialkyl-substituted carboxylic acid amide dialkyl acetal compound or the like is at least 5 mass%, and the content of the silica is 5-150 pts.mass based on 100 pts.mass of the rubber component.

Description

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

In recent years, due to increasing interest in environmental issues, there has been a strong demand for lower fuel consumption for automobiles, and rubber compositions used for automobile tires are also required to have excellent fuel efficiency. . As a rubber composition for an automobile tire, a rubber composition containing a conjugated diene polymer such as polybutadiene or butadiene-styrene copolymer and a filler such as carbon black or silica is used.

As a method for improving fuel economy, for example, Patent Document 1 proposes a method using a diene rubber (modified rubber) modified with an organosilicon compound containing an amino group and an alkoxy group. However, in recent years, further improvement in fuel efficiency has been demanded. In addition, the performance required for rubber compositions for automobile tires includes wet grip performance, wear resistance, and rubber strength, but these performances are generally in contradiction with low fuel consumption, It was difficult to obtain high performance in a well-balanced manner.

Patent Document 2 proposes a method of blending a specific reversion inhibitor with isoprene-based rubber to achieve both low fuel consumption and wear resistance. However, there is still room for improvement in terms of improving fuel economy, wet grip performance, wear resistance, and rubber strength in a balanced manner.

JP 2000-344955 A JP 2006-45471 A

An object of the present invention is to solve the above-mentioned problems and to provide a rubber composition that can improve fuel economy, wet grip performance, wear resistance, and rubber strength in a well-balanced manner, and a pneumatic tire using the same.

［式中、Ｘ^１、Ｘ^２及びＸ^３は、それぞれ独立に、下式（Ｉａ）で表される基、水酸基、ヒドロカルビル基又は置換ヒドロカルビル基を表し、Ｘ^１、Ｘ^２及びＸ^３の少なくとも１つが、下式（Ｉａ）で表される基又は水酸基である。］

［式中、Ｒ^１及びＲ^２は、それぞれ独立に、炭素原子数が１〜６のヒドロカルビル基、炭素原子数が１〜６の置換ヒドロカルビル基、シリル基又は置換シリル基を表し、Ｒ^１及びＲ^２は結合して窒素原子と共に環構造を形成していてもよい。］

［式中、ｍは１〜１１の整数を表し、Ａは窒素原子を有する官能基を表す。］

［式中、Ｗは炭素数２〜１０のアルキレン基、Ｒ^１３及びＲ^１４は、同一若しくは異なって、窒素原子を含む１価の有機基を表す。］ The present invention contains a rubber component, silica and a compound represented by the following formula (1), and among 100% by mass of the rubber component, a structural unit based on a conjugated diene and a structural unit represented by the following formula (I): The content of the conjugated diene polymer obtained by modifying at least one end of the polymer with a compound having a group represented by the following formula (II) is 5% by mass or more, and the rubber component is 100% by mass. It is related with the rubber composition whose content of the said silica with respect to a part is 5-150 mass parts.

[Wherein, X ¹ , X ² and X ³ each independently represent a group represented by the following formula (Ia), a hydroxyl group, a hydrocarbyl group or a substituted hydrocarbyl group, and at least ^one of X ¹ , X ² and X ³ One is a group or a hydroxyl group represented by the following formula (Ia). ]

[Wherein, R ¹ and R ² independently denote a hydrocarbyl group having 1 to 6 carbon atoms, a substituted hydrocarbyl group having 1-6 carbon atoms, or a substituted silyl group, R ¹ and R ² may be bonded to form a ring structure with the nitrogen atom. ]

[Wherein, m represents an integer of 1 to 11, and A represents a functional group having a nitrogen atom. ]

[Wherein, W represents an alkylene group having 2 to 10 carbon atoms, and R ¹³ and R ¹⁴ are the same or different and each represents a monovalent organic group containing a nitrogen atom. ]

R ¹ and R ^{2 in} formula (Ia) are preferably hydrocarbyl groups having 1 to 6 carbon atoms.
^Two of X ¹ , X ² and X ^{3 in} the formula (I) are preferably a group or a hydroxyl group represented by the formula (Ia).

［式中、ｎは０〜１０の整数を表し、Ｒ^３は炭素原子数が１〜５のヒドロカルビル基を表し、Ｒ^４、Ｒ^５、Ｒ^６及びＲ^７は、それぞれ独立に、水素原子、炭素原子数が１〜５のヒドロカルビル基、炭素原子数が１〜５の置換ヒドロカルビル基又は炭素原子数が１〜５のヒドロカルビルオキシ基を表し、Ｒ^４及びＲ^５が複数ある場合は、複数あるＲ^４及び複数あるＲ^５はそれぞれ同じであっても異なっていてもよく、Ｒ^８及びＲ^９は、それぞれ独立に、窒素原子、酸素原子及びケイ素原子からなる原子群から選ばれる少なくとも１種の原子を有していてもよい炭素原子数が１〜６の基を表し、Ｒ^８及びＲ^９は結合して窒素原子と共に環構造を形成していてもよく、Ｒ^８及びＲ^９は窒素に二重結合で結合する同一の基であってもよい。］
また、式（ＩＩＩ）のＲ^６及びＲ^７の一方が水素原子であることが好ましい。 The compound having a group represented by the formula (II) is preferably a compound represented by the following formula (III).

[Wherein n represents an integer of 0 to 10, R ³ represents a hydrocarbyl group having 1 to 5 carbon atoms, and R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represent a hydrogen atom, A hydrocarbyl group having 1 to 5 carbon atoms, a substituted hydrocarbyl group having 1 to 5 carbon atoms or a hydrocarbyloxy group having 1 to 5 carbon atoms, and when there are a plurality of R ⁴ and R ^5, there are plural R ⁴ and a plurality of R ⁵ may be the same or different, and R ⁸ and R ⁹ are each independently at least one selected from the group consisting of a nitrogen atom, an oxygen atom and a silicon atom. atom represents even though a good number of carbon atoms from 1 to 6 groups have, R ⁸ and R ⁹ may form a ring structure with bonded to a nitrogen atom, R ⁸ and R ⁹ are nitrogen It may be the same group bonded by a double bond ]
Moreover, it is preferable that one of R ⁶ and R ^{7 in} the formula (III) is a hydrogen atom.

The vinyl bond amount of the conjugated diene polymer is preferably 10 mol% or more and 80 mol% or less, with the content of the structural unit based on the conjugated diene being 100 mol%.
The rubber composition preferably contains natural rubber and / or butadiene rubber.
The silica preferably has a nitrogen adsorption specific surface area of 40 to 400 m ² / g.

The content of the compound represented by the formula (1) with respect to 100 parts by mass of the rubber component is preferably 5 to 23 parts by mass.
The rubber composition preferably contains 0.1 to 7 parts by mass of sulfur with respect to 100 parts by mass of the rubber component.

The rubber composition is preferably used as a tread rubber composition.
The present invention also relates to a pneumatic tire produced using the rubber composition.

According to the present invention, since it is a rubber composition containing a specific conjugated diene polymer, silica, and a specific compound, fuel economy, wet grip performance, wear resistance, and rubber strength are improved in a well-balanced manner. Pneumatic tires can be provided.

［式中、Ｘ^１、Ｘ^２及びＸ^３は、それぞれ独立に、下式（Ｉａ）で表される基、水酸基、ヒドロカルビル基又は置換ヒドロカルビル基を表し、Ｘ^１、Ｘ^２及びＸ^３の少なくとも１つが、下式（Ｉａ）で表される基又は水酸基である。］

［式中、Ｒ^１及びＲ^２は、それぞれ独立に、炭素原子数が１〜６のヒドロカルビル基、炭素原子数が１〜６の置換ヒドロカルビル基、シリル基又は置換シリル基を表し、Ｒ^１及びＲ^２は結合して窒素原子と共に環構造を形成していてもよい。］

［式中、ｍは１〜１１の整数を表し、Ａは窒素原子を有する官能基を表す。］ The rubber composition of the present invention has a structural unit based on a conjugated diene and a structural unit represented by the following formula (I), and at least one end of the polymer is formed by a compound having a group represented by the following formula (II). A modified conjugated diene polymer, silica, and a compound represented by the formula (1) are contained.

[Wherein, X ¹ , X ² and X ³ each independently represent a group represented by the following formula (Ia), a hydroxyl group, a hydrocarbyl group or a substituted hydrocarbyl group, and at least ^one of X ¹ , X ² and X ³ One is a group or a hydroxyl group represented by the following formula (Ia). ]

[Wherein, R ¹ and R ² independently denote a hydrocarbyl group having 1 to 6 carbon atoms, a substituted hydrocarbyl group having 1-6 carbon atoms, or a substituted silyl group, R ¹ and R ² may be bonded to form a ring structure with the nitrogen atom. ]

[Wherein, m represents an integer of 1 to 11, and A represents a functional group having a nitrogen atom. ]

Examples of the conjugated diene based on the conjugated diene include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, 1,3-hexadiene, and the like. These may be one type or two or more types. From the viewpoint of availability, 1,3-butadiene and isoprene are preferable.

X ¹ , X ² and X ³ in formula (I) of the structural unit represented by formula (I) each independently represent a group represented by formula (Ia), a hydroxyl group, a hydrocarbyl group or a substituted hydrocarbyl group. , X ¹ , X ² and X ³ are a group represented by the formula (Ia) or a hydroxyl group.

R ¹ and R ^{2 in} formula (Ia) each independently represent a hydrocarbyl group having 1 to 6 carbon atoms, a substituted hydrocarbyl group having 1 to 6 carbon atoms, a silyl group, or a substituted silyl group, and R ¹ And R ² may be bonded together to form a ring structure together with the nitrogen atom.

As used herein, a hydrocarbyl group represents a hydrocarbon residue. Here, the hydrocarbon residue represents a monovalent group obtained by removing hydrogen from a hydrocarbon. A substituted hydrocarbyl group represents a group in which one or more hydrogen atoms of a hydrocarbon residue are substituted with a substituent. The hydrocarbyloxy group represents a group in which a hydrogen atom of a hydroxyl group is substituted with a hydrocarbyl group, and the substituted hydrocarbyloxy group represents a group in which one or more hydrogen atoms of the hydrocarbyloxy group are substituted with a substituent. The substituted silyl group represents a group in which one or more hydrogen atoms of the silyl group are substituted with a substituent.

Examples of the hydrocarbyl group having 1 to 6 carbon atoms of R ¹ and R ² include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n- Examples thereof include alkyl groups such as pentyl group, neopentyl group, isopentyl group and n-hexyl group; cycloalkyl groups such as cyclohexyl group; phenyl groups and the like.

The substituted hydrocarbyl group having 1 to 6 carbon atoms in R ¹ and R ² includes at least one group selected from the group consisting of a group having a nitrogen atom, a group having an oxygen atom, and a group having a silicon atom. The substituted hydrocarbyl group which has as a substituent can be mention | raise | lifted. Examples of the group having a group having a nitrogen atom as a substituent include dialkylaminoalkyl groups such as a dimethylaminoethyl group and a diethylaminoethyl group. Examples of the group having a group having an oxygen atom as a substituent include methoxymethyl Group, alkoxyalkyl group such as methoxyethyl group, ethoxymethyl group, ethoxyethyl group and the like, and groups having a silicon atom as a substituent include trialkylsilylalkyl groups such as trimethylsilylmethyl group, etc. I can give you.

Examples of the substituted silyl group for R ¹ and R ² include trialkylsilyl groups such as a trimethylsilyl group, a triethylsilyl group, and a t-butyldimethylsilyl group.

The group to which R ¹ and R ² are bonded is a divalent group having 1 to 12 carbon atoms that may have at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom and a silicon atom. Group. For example, an alkylene group such as a trimethylene group, a tetramethylene group, a pentamethylene group, and a hexamethylene group; an oxydialkylene group such as an oxydiethylene group and an oxydipropylene group; and —CH ₂ CH ₂ —NH—CH ₂ — And a nitrogen-containing group such as a group represented by —CH ₂ CH ₂ —N═CH—.

The group to which R ¹ and R ² are bonded is preferably a nitrogen-containing group, a group represented by —CH ₂ CH ₂ —NH—CH ₂ —, a group represented by —CH ₂ CH ₂ —N═CH—. Is more preferable.

The hydrocarbyl group of R ¹ and R ² is preferably an alkyl group, more preferably an alkyl group having 1 to 4 carbon atoms, further preferably a methyl group, an ethyl group, an n-propyl group, or an n-butyl group, Group, n-butyl group is particularly preferred. The substituted hydrocarbyl group for R ¹ and R ² is preferably an alkoxyalkyl group, and more preferably an alkoxyalkyl group having 1 to 4 carbon atoms. The substituted silyl group for R ¹ and R ² is preferably a trialkylsilyl group, and more preferably a trimethylsilyl group.

R ¹ and R ² are preferably an alkyl group, an alkoxyalkyl group, a substituted silyl group, or a nitrogen-containing group to which R ¹ and R ² are bonded, more preferably an alkyl group, still more preferably carbon. It is an alkyl group having 1 to 4 atoms, and more preferably a methyl group, an ethyl group, an n-propyl group, or an n-butyl group.

Examples of the group represented by the formula (Ia) include an acyclic amino group and a cyclic amino group.

Examples of the acyclic amino group include dimethylamino group, diethylamino group, di (n-propyl) amino group, di (isopropyl) amino group, di (n-butyl) amino group, di (sec-butyl) amino group, di ( dialkylamino groups such as tert-butyl) amino group, di (neopentyl) amino group, ethylmethylamino group; di (methoxymethyl) amino group, di (methoxyethyl) amino group, di (ethoxymethyl) amino group, di ( And di (alkoxyalkyl) amino groups such as ethoxyethyl) amino group; and di (trialkylsilyl) amino groups such as di (trimethylsilyl) amino group and di (t-butyldimethylsilyl) amino group.

Examples of the cyclic amino group include 1-pyrrolidinyl group, 1-piperidino group, 1-hexamethyleneimino group, 1-heptamethyleneimino group, 1-octamethyleneimino group, 1-decamethyleneimino group, 1-dodecamethyleneimino. 1-polymethyleneimino groups such as groups can be mentioned. Examples of the cyclic amino group include 1-imidazolyl group, 4,5-dihydro-1-imidazolyl group, 1-imidazolidinyl group, 1-piperazinyl group, morpholino group and the like.

The group represented by the formula (Ia) is preferably an acyclic amino group, more preferably a dialkylamino group, and still more preferably 1 to 1 carbon atoms from the viewpoint of economy and availability. A dialkylamino group substituted with 4 alkyl groups, and more preferably a dimethylamino group, a diethylamino group, a di (n-propyl) amino group, and a di (n-butyl) amino group.

Examples of the hydrocarbyl group of X ^{1 to} X ^{3 in} the formula (I) include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, and tert-butyl group. be able to. Examples of the substituted hydrocarbyl group include alkoxyalkyl groups such as a methoxymethyl group, an ethoxymethyl group, a methoxyethyl group, and an ethoxyethyl group.

The hydrocarbyl group of X ^{1 to} X ³ is preferably an alkyl group, more preferably an alkyl group having 1 to 4 carbon atoms, and still more preferably a methyl group or an ethyl group. Furthermore, the substituted hydrocarbyl group X ¹ to X ^3, preferably an alkoxyalkyl group, more preferably an alkoxyalkyl group having 1 to 4 carbon atoms.

The hydrocarbyl group and substituted hydrocarbyl group of X ^{1 to} X ³ are preferably an alkyl group or an alkoxyalkyl group, and more preferably an alkyl group having 1 to 4 carbon atoms or an alkyl group having 1 to 4 carbon atoms. It is an alkoxyalkyl group, more preferably an alkyl group having 1 to 4 carbon atoms, and still more preferably a methyl group or an ethyl group.

At least one of X ¹ , X ² and X ^{3 in} the formula (I) is a group or a hydroxyl group represented by the formula (Ia). Preferably, two or more of X ¹ , X ² and X ³ are a group or a hydroxyl group represented by the formula (Ia), more preferably ^{two of} X ¹ , X ² and X ³ are represented by the formula (Ia ) Or a hydroxyl group. Further, fuel economy, wet grip performance, abrasion resistance and rubber strength in terms of good balance is obtained at a high level, preferably at least one of hydroxyl group of X ^1, X ² and X ^3, X ^1, It is more preferable that two or more of X ² and X ³ are hydroxyl groups, and it is more preferable that ^{two of} X ¹ , X ² and X ³ are hydroxyl groups.

From the viewpoint of improving the fuel efficiency, wet grip performance, wear resistance and rubber strength in a well-balanced manner, as the structural unit represented by the formula (I), ^{two of} X ¹ , X ² and X ³ are an acyclic amino group or A structural unit that is a hydroxyl group is preferred. As the structural unit in which ^{two of} X ¹ , X ² and X ³ are acyclic amino groups, bis (dialkylamino) alkylvinylsilane units are preferred, bis (dimethylamino) methylvinylsilane units, bis (diethylamino) methylvinylsilane units, Bis (di (n-propyl) amino) methylvinylsilane units and bis (di (n-butyl) amino) methylvinylsilane units are more preferred. As the structural unit in which two of X ¹ , X ² and X ³ are hydroxyl groups, a dihydroxyalkylvinylsilane unit is preferable, and a dihydroxymethylvinylsilane unit is more preferable.

The content of the structural unit represented by the formula (I) in the conjugated diene polymer is preferably from the viewpoint of improving the fuel economy, wet grip performance, wear resistance and rubber strength in a balanced manner, per polymer unit mass. Is 0.001 mmol / g polymer or more and 0.1 mmol / g polymer or less. More preferably, it is 0.002 mmol / g polymer or more and 0.07 mmol / g polymer or less. More preferably, it is 0.003 mmol / g polymer or more and 0.05 mmol / g polymer or less.

［式中、ｍは１〜１１の整数を表し、Ａは窒素原子を有する官能基を表す。］ The conjugated diene polymer is a polymer obtained by modifying at least one end of a polymer with a compound having a group represented by the following formula (II).

[Wherein, m represents an integer of 1 to 11, and A represents a functional group having a nitrogen atom. ]

m represents an integer of 1 to 11. From the viewpoint of improving fuel efficiency, it is preferably 1 or more, and from the viewpoint of improving economy during production, it is preferably 4 or less. A is a functional group having a nitrogen atom, and examples thereof include an amino group, an isocyano group, a cyano group, a pyridyl group, a piperidyl group, a pyrazinyl group, and a morpholino group.

［式中、ｎは０〜１０の整数を表し、Ｒ^３は炭素原子数が１〜５のヒドロカルビル基を表し、Ｒ^４、Ｒ^５、Ｒ^６及びＲ^７は、それぞれ独立に、水素原子、炭素原子数が１〜５のヒドロカルビル基、炭素原子数が１〜５の置換ヒドロカルビル基又は炭素原子数が１〜５のヒドロカルビルオキシ基を表し、Ｒ^４及びＲ^５が複数ある場合は、複数あるＲ^４及び複数あるＲ^５はそれぞれ同じであっても異なっていてもよく、Ｒ^８及びＲ^９は、それぞれ独立に、窒素原子、酸素原子及びケイ素原子からなる原子群から選ばれる少なくとも１種の原子を有していてもよい炭素原子数が１〜６の基を表し、Ｒ^８及びＲ^９は結合して窒素原子と共に環構造を形成していてもよく、Ｒ^８及びＲ^９は窒素に二重結合で結合する同一の基であってもよい。］ Examples of the compound having a group represented by the formula (II) include a compound represented by the following formula (III).

[Wherein n represents an integer of 0 to 10, R ³ represents a hydrocarbyl group having 1 to 5 carbon atoms, and R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represent a hydrogen atom, A hydrocarbyl group having 1 to 5 carbon atoms, a substituted hydrocarbyl group having 1 to 5 carbon atoms or a hydrocarbyloxy group having 1 to 5 carbon atoms, and when there are a plurality of R ⁴ and R ^5, there are plural R ⁴ and a plurality of R ⁵ may be the same or different, and R ⁸ and R ⁹ are each independently at least one selected from the group consisting of a nitrogen atom, an oxygen atom and a silicon atom. atom represents even though a good number of carbon atoms from 1 to 6 groups have, R ⁸ and R ⁹ may form a ring structure with bonded to a nitrogen atom, R ⁸ and R ⁹ are nitrogen It may be the same group bonded by a double bond ]

N of Formula (III) represents the integer of 0-10. From the viewpoint of improving economy, it is preferably 3 or less, more preferably 0.

R ^{3 in} formula (III) represents a hydrocarbyl group having 1 to 5 carbon atoms. Examples of the hydrocarbyl group of R ³ include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, and t-butyl group.

The hydrocarbyl group for R ³ is preferably an alkyl group, more preferably an alkyl group having 1 to 4 carbon atoms, and still more preferably a methyl group or an ethyl group.

R ^{4 to} R ^{7 in} formula (III) are each independently a hydrogen atom, a hydrocarbyl group having 1 to 5 carbon atoms, a substituted hydrocarbyl group having 1 to 5 carbon atoms, or 1 to 5 carbon atoms. represent hydrocarbyl group, when R ⁴ and R ⁵ are a plurality, the R ⁵ to R is ⁴ and a plurality of plurality of may be different even in the same, respectively.

Examples of the hydrocarbyl group of R ^{4 to} R ⁷ include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, and t-butyl group.

Examples of the substituted hydrocarbyl group of R ^{4 to} R ⁷ include a substituted hydrocarbyl group having as a substituent at least one group selected from the group consisting of a group having a nitrogen atom and a group having an oxygen atom. Examples of the group having a group having a nitrogen atom as a substituent include dialkylaminoalkyl groups such as a dimethylaminoethyl group and a diethylaminoethyl group. Examples of the group having a group having an oxygen atom as a substituent include methoxymethyl And alkoxyalkyl groups such as a methoxyethyl group, an ethoxymethyl group, and an ethoxyethyl group.

Examples of the hydrocarbyloxy group of R ^{4 to} R ⁷ include alkoxy groups such as a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, and a t-butoxy group. .

The hydrocarbyl group of R ^{4 to} R ⁷ is preferably an alkyl group, more preferably an alkyl group having 1 to 4 carbon atoms, and still more preferably a methyl group or an ethyl group.

The substituted hydrocarbyl group of R ^{4 to} R ⁷ is preferably an alkoxyalkyl group, more preferably an alkoxyalkyl group having 1 to 4 carbon atoms, and still more preferably a methoxymethyl group or an ethoxyethyl group. .

The hydrocarbyloxy group of R ^{4 to} R ⁷ is preferably an alkoxy group, more preferably an alkoxy group having 1 to 3 carbon atoms, and still more preferably a methoxy group or an ethoxy group.

From the viewpoint of improving fuel economy, wet grip performance, wear resistance and rubber strength in a well-balanced manner and economical efficiency, one of R ⁶ and R ⁷ is preferably a hydrogen atom. More preferably, one of R ⁶ and R ⁷ is a hydrogen atom, and the other is an alkyl group or an alkoxy group. More preferably, one of R ⁶ and R ⁷ is a hydrogen atom, and the other is an alkoxy group. Particularly preferred are a methoxy group and an ethoxy group.

R ⁸ and R ^{9 in} formula (III) each independently have 1 to 6 carbon atoms which may have at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom and a silicon atom. R ⁸ and R ⁹ may be bonded to form a ring structure together with the nitrogen atom, and R ⁸ and R ⁹ may be the same group bonded to nitrogen by a double bond.

Examples of R ⁸ and R ^{9 in} formula (III) include a hydrocarbyl group having 1 to 6 carbon atoms, a substituted hydrocarbyl group having 1 to 6 carbon atoms, and a substituted silyl group.

Examples of the hydrocarbyl group of R ⁸ and R ⁹ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, neopentyl group, and isopentyl group. And alkyl groups such as n-hexyl group; cycloalkyl groups such as cyclohexyl group; phenyl groups and the like.

The substituted hydrocarbyl group of R ⁸ and R ^{9 is} a substituted hydrocarbyl group having as a substituent at least one group selected from the group consisting of a group having a nitrogen atom, a group having an oxygen atom and a group having a silicon atom. I can give you. Examples of the group having a group having a nitrogen atom as a substituent include dialkylaminoalkyl groups such as a dimethylaminoethyl group and a diethylaminoethyl group. Examples of the group having a group having an oxygen atom as a substituent include methoxymethyl Group, alkoxyalkyl group such as methoxyethyl group, ethoxymethyl group, ethoxyethyl group; alkylene oxide group such as epoxy group, tetrahydrofuranyl group; alkylene oxide alkyl group such as glycidyl group, tetrahydrofurfuryl group, etc. Examples of the group having a group having a silicon atom as a substituent include a trialkylsilylalkyl group such as a trimethylsilylmethyl group.
In the present specification, the alkylene oxide group represents a monovalent group obtained by removing a hydrogen atom from a ring of a cyclic ether compound. The alkylene oxide alkyl group represents a group in which one or more hydrogen atoms of the alkyl group are substituted with an alkylene oxide group.

Examples of the substituted silyl group for R ⁸ and R ⁹ include a trialkylsilyl group such as a trimethylsilyl group, a triethylsilyl group, and a t-butyldimethylsilyl group; a trialkoxysilyl group such as a trimethoxysilyl group.

The group to which R ⁸ and R ⁹ are bonded is a divalent group having 2 to 12 carbon atoms that may have at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom and a silicon atom. Group. For example, an alkylene group such as a trimethylene group, a tetramethylene group, a pentamethylene group, and a hexamethylene group; an oxydialkylene group such as an oxydiethylene group and an oxydipropylene group; and —CH ₂ CH ₂ —NH—CH ₂ — And a nitrogen-containing group such as a group represented by —CH ₂ CH ₂ —N═CH—.

The group to which R ⁸ and R ⁹ are bonded is preferably a nitrogen-containing group, a group represented by —CH ₂ CH ₂ —NH—CH ₂ —, a group represented by —CH ₂ CH ₂ —N═CH—. Is more preferable.

As the same group bonded to the nitrogen of R ⁸ and R ^{9 by} a double bond, the number of carbon atoms optionally having at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom and a silicon atom 2 to 12 divalent groups. Examples thereof include an ethylidene group, 1-methylpropylidene group, 1,3-dimethylbutylidene group, 1-methylethylidene group, 4-N, N-dimethylaminobenzylidene group.

The hydrocarbyl group of R ⁸ and R ⁹ is preferably an alkyl group, more preferably an alkyl group having 1 to 4 carbon atoms, still more preferably a methyl group, an ethyl group, or an n-propyl group. , An n-butyl group, and more preferably a methyl group or an ethyl group. The substituted hydrocarbyl group for R ⁸ and R ⁹ is preferably an alkoxyalkyl group, an alkylene oxide group, or an alkylene oxide alkyl group. The substituted silyl group for R ⁸ and R ⁹ is preferably a trialkylsilyl group or a trialkoxysilyl group, more preferably a trialkylsilyl group, still more preferably a trimethylsilyl group or a triethylsilyl group. .

R ⁸ and R ⁹ are preferably an alkyl group, an alkoxyalkyl group, a substituted silyl group, or a nitrogen-containing group to which R ⁸ and R ⁹ are bonded, and more preferably an alkyl group having 1 to 4 carbon atoms. More preferred are a methyl group, an ethyl group, an n-propyl group, and an n-butyl group, and even more preferred are a methyl group and an ethyl group.

Examples of the amino group in which R ⁸ and R ⁹ are bonded to a nitrogen atom include an acyclic amino group and a cyclic amino group.

Examples of the acyclic amino group include dimethylamino group, diethylamino group, di (n-propyl) amino group, di (isopropyl) amino group, di (n-butyl) amino group, di (sec-butyl) amino group, di ( dialkylamino groups such as tert-butyl) amino group, di (neopentyl) amino group, ethylmethylamino group; di (methoxymethyl) amino group, di (methoxyethyl) amino group, di (ethoxymethyl) amino group, di ( And di (alkoxyalkyl) amino groups such as ethoxyethyl) amino group; and di (trialkylsilyl) amino groups such as di (trimethylsilyl) amino group and di (t-butyldimethylsilyl) amino group. In addition, di (alkylene oxide) amino groups such as di (epoxy) amino groups and di (tetrahydrofuranyl) amino groups; di (alkylene oxide alkyl) amino groups such as di (glycidyl) amino groups and di (tetrahydrofurfuryl) amino groups You can raise a group. Furthermore, an ethylideneamino group, 1-methylpropylideneamino group, 1,3-dimethylbutylideneamino group, 1-methylethylideneamino group, 4-N, N-dimethylaminobenzylideneamino group, and the like can also be mentioned.

Examples of the cyclic amino group include 1-pyrrolidinyl group, 1-piperidino group, 1-hexamethyleneimino group, 1-heptamethyleneimino group, 1-octamethyleneimino group, 1-decamethyleneimino group, 1-dodecamethyleneimino. 1-polymethyleneimino groups such as groups can be mentioned. Examples of the cyclic amino group include 1-imidazolyl group, 4,5-dihydro-1-imidazolyl group, 1-imidazolidinyl group, 1-piperazinyl group, morpholino group and the like.

The amino group in which R ⁸ and R ⁹ are bonded to a nitrogen atom is preferably an acyclic amino group from the viewpoint of low fuel consumption, wet grip performance, abrasion resistance, rubber strength, long-term stability and availability of the compound. More preferably a dialkylamino group, still more preferably a dimethylamino group or a diethylamino group.

Examples of the compound represented by the formula (III) include N, N-dialkyl-substituted carboxylic acid amide dialkyl acetal compounds.

As the N, N-dialkyl-substituted carboxylic acid amide dialkyl acetal compound,
N, N-dimethylformamide dimethyl acetal, N, N-diethylformamide dimethyl acetal, N, N-di (n-propyl) formamide dimethyl acetal,
N, N-dimethylformamide diethyl acetal, N, N-diethylformamide diethyl acetal, N, N-di (n-propyl) formamide diethyl acetal,
N, N-dialkylformamide dialkyl acetals such as N, N-dimethylformamide ethyl methyl acetal, N, N-diethylformamide ethyl methyl acetal, N, N-di (n-propyl) formamide ethyl methyl acetal;

N, N-dimethylacetamide dimethyl acetal, N, N-diethylacetamide dimethyl acetal, N, N-di (n-propyl) acetamide dimethyl acetal,
N, N-dimethylacetamide diethyl acetal, N, N-diethylacetamide diethyl acetal, N, N-di (n-propyl) acetamide diethyl acetal,
N, N-dialkylacetamido dialkyl acetals such as N, N-dimethylacetamidoethyl methyl acetal, N, N-diethylacetamidoethyl methyl acetal, N, N-di (n-propyl) acetamidoethyl methyl acetal;

N, N-dimethylpropionamide dimethyl acetal, N, N-diethylpropionamide dimethyl acetal, N, N-di (n-propyl) propionamide dimethyl acetal,
N, N-dimethylpropionamide diethyl acetal, N, N-diethylpropionamide diethyl acetal, N, N-di (n-propyl) propionamide diethyl acetal,
N, N-dimethylpropionamidoethyl methyl acetal, N, N-diethylpropionamidoethyl methyl acetal, N, N-di (n-propyl) propionamidoethyl methyl acetal, N, N-dialkylpropionamido dialkyl acetal, etc. can give.

Among these, from the viewpoint of improving the fuel efficiency, wet grip performance, wear resistance and rubber strength in a balanced manner,
N, N-dialkylformamide dialkyl acetal,
More preferably,
N, N-dimethylformamide dimethyl acetal,
N, N-diethylformamide dimethyl acetal,
N, N-dimethylformamide diethyl acetal,
N, N-diethylformamide diethyl acetal.

The conjugated diene polymer may have a constituent unit based on another monomer in addition to the constituent unit based on the conjugated diene (conjugated diene unit). Examples of the other monomer include aromatic vinyl, vinyl nitrile, and unsaturated carboxylic acid ester. Examples of the aromatic vinyl include styrene, α-methylstyrene, vinyl toluene, vinyl naphthalene, divinyl benzene, trivinyl benzene, and divinyl naphthalene. Examples of the vinyl nitrile include acrylonitrile, and examples of the unsaturated carboxylic acid ester include methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate. Among these, aromatic vinyl is preferable, and styrene is more preferable.

The conjugated diene polymer preferably has a structural unit based on aromatic vinyl (aromatic vinyl unit) from the viewpoint of wear resistance. The content of the aromatic vinyl unit is preferably a conjugated diene unit. And the total amount of aromatic vinyl units is 100% by mass, preferably 10% by mass or more (conjugated diene unit content is 90% by mass or less), more preferably 15% by mass or more (conjugate diene unit content) Is 85% by mass or less). Further, from the viewpoint of low fuel consumption, the content of the aromatic vinyl unit is preferably 50% by mass or less (the content of the conjugated diene unit is 50% by mass or more), more preferably 45% by mass or less (conjugated diene). The unit content is 55% by mass or more).

The vinyl bond content of the conjugated diene polymer is preferably 80 mol% or less, more preferably 70 mol% or less from the viewpoint of fuel efficiency, with the content of the conjugated diene unit being 100 mol%. Moreover, from a viewpoint of wet grip performance, Preferably it is 10 mol% or more, More preferably, it is 15 mol% or more, More preferably, it is 20 mol% or more, Most preferably, it is 40 mol% or more. The vinyl bond amount is determined from the absorption intensity in the vicinity of 910 cm ^−1, which is the absorption peak of the vinyl group, by infrared spectroscopy.

The molecular weight distribution of the conjugated diene polymer is preferably 1 to 5, more preferably 1 to 2, from the viewpoint of low fuel consumption. The molecular weight distribution is obtained by measuring the number average molecular weight (Mn) and the weight average molecular weight (Mw) by gel permeation chromatography (GPC) method and dividing Mw by Mn.

［式中、Ｘ^４、Ｘ^５及びＸ^６は、それぞれ独立に、下式（ＩＶａ）で表される基、ヒドロカルビル基又は置換ヒドロカルビル基を表し、Ｘ^４、Ｘ^５及びＸ^６の少なくとも１つが、下式（ＩＶａ）で表される基である。］

［式中、Ｒ^１０及びＲ^１１は、それぞれ独立に、炭素原子数が１〜６のヒドロカルビル基、炭素原子数が１〜６の置換ヒドロカルビル基、シリル基又は置換シリル基を表し、Ｒ^１０及びＲ^１１は結合して窒素原子と共に環構造を形成していてもよい。］
（工程Ｂ）：工程Ａで得られた重合体と下式（ＩＩ）で表される基を有する化合物とを反応させる工程。

［式中、ｍは１〜１１の整数を表し、Ａは窒素原子を有する官能基を表す。］ As a suitable production method of the conjugated diene polymer, there can be mentioned a production method having the following steps A and B.
(Step A): In a hydrocarbon solvent, a monomer containing a conjugated diene and a vinyl compound represented by the following formula (IV) is polymerized with an alkali metal catalyst, and a monomer unit based on the conjugated diene and A step of obtaining a polymer having an alkali metal derived from the catalyst at at least one end of a polymer chain having a monomer unit based on a vinyl compound represented by the formula (IV).

[Wherein, X ⁴ , X ⁵ and X ⁶ each independently represent a group represented by the following formula (IVa), a hydrocarbyl group or a substituted hydrocarbyl group, wherein at least one of X ⁴ , X ⁵ and X ⁶ is And a group represented by the following formula (IVa). ]

^{Wherein, R 10} and ^{R 11} each independently represent a hydrocarbyl group having 1 to 6 carbon atoms, a substituted hydrocarbyl group having 1-6 carbon atoms, a silyl group, or a substituted silyl ^{group, R 10} and R ¹¹ may be bonded to form a ring structure with the nitrogen atom. ]
(Step B): A step of reacting the polymer obtained in Step A with a compound having a group represented by the following formula (II).

[Wherein, m represents an integer of 1 to 11, and A represents a functional group having a nitrogen atom. ]

Examples of the alkali metal catalyst used in (Step A) include alkali metals, organic alkali metal compounds, complexes of alkali metals and polar compounds, oligomers having alkali metals, and the like. Examples of the alkali metal include lithium, sodium, potassium, rubidium, cesium and the like. Examples of the organic alkali metal compound include ethyl lithium, n-propyl lithium, iso-propyl lithium, n-butyl lithium, sec-butyl lithium, t-octyl lithium, n-decyl lithium, phenyl lithium, 2-naphthyl lithium, 2 -Butylphenyllithium, 4-phenylbutyllithium, cyclohexyllithium, 4-cyclopentyllithium, dimethylaminopropyllithium, diethylaminopropyllithium, t-butyldimethylsiloxypropyllithium, N-morpholinopropyllithium, lithium hexamethyleneimide, lithium pyrrole Zido, lithium piperidide, lithium heptamethylene imide, lithium dodecamethylene imide, 1,4-dilithio-2-butene, sodium naphthalenide, sodium Bifenirido, such as potassium napthalenide can be mentioned. Examples of the complex of alkali metal and polar compound include potassium-tetrahydrofuran complex and potassium-diethoxyethane complex. Examples of the oligomer having alkali metal include sodium salt of α-methylstyrene tetramer. Can do. Among these, an organic lithium compound or an organic sodium compound is preferable, and an organic lithium compound or an organic sodium compound having 2 to 20 carbon atoms is more preferable.

The hydrocarbon solvent used in (Step A) is a solvent that does not deactivate the organic alkali metal compound catalyst, and examples thereof include aliphatic hydrocarbons, aromatic hydrocarbons, and alicyclic hydrocarbons. Examples of the aliphatic hydrocarbon include propane, n-butane, iso-butane, n-pentane, iso-pentane, n-hexane, propene, 1-butene, iso-butene, trans-2-butene, cis-2- Examples include butene, 1-pentene, 2-pentene, 1-hexene, 2-hexene and the like. In addition, examples of the aromatic hydrocarbon include benzene, toluene, xylene, and ethylbenzene. Examples of the alicyclic hydrocarbon include cyclopentane and cyclohexane. These may be used alone or in combination of two or more. In these, a C2-C12 hydrocarbon is preferable.

In (Step A), a monomer containing a conjugated diene and a vinyl compound represented by formula (IV) is polymerized, and a conjugated diene polymer having an alkali metal derived from the above-mentioned alkali metal catalyst at the polymer chain end. Manufacturing. Examples of the conjugated diene include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, and 1,3-hexadiene. Used in combination of more than one species. Among these, 1,3-butadiene and isoprene are preferable from the viewpoint of availability.

X ⁴ , X ⁵ and X ⁶ in the formula (IV) each independently represent a group represented by the formula (IVa), a hydrocarbyl group or a substituted hydrocarbyl group, and at least one of X ⁴ , X ⁵ and X ⁶ Is a group represented by the formula (IVa).

R ¹⁰ and R ^{11 in} formula (IVa) each independently represent a hydrocarbyl group having 1 to 6 carbon atoms, a substituted hydrocarbyl group having 1 to 6 carbon atoms, a silyl group, or a substituted silyl group, and R ¹⁰ And R ¹¹ may be bonded together to form a ring structure together with the nitrogen atom.

Examples of the hydrocarbyl group having 1 to 6 carbon atoms of R ¹⁰ and R ¹¹ include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n- Examples thereof include alkyl groups such as pentyl group, neopentyl group, isopentyl group and n-hexyl group; cycloalkyl groups such as cyclohexyl group; phenyl groups and the like.

The substituted hydrocarbyl group having 1 to 6 carbon atoms of R ¹⁰ and R ¹¹ is at least one group selected from the group consisting of a group having a nitrogen atom, a group having an oxygen atom, and a group having a silicon atom. The substituted hydrocarbyl group which has as a substituent can be mention | raise | lifted. Examples of the group having a group having a nitrogen atom as a substituent include dialkylaminoalkyl groups such as a dimethylaminoethyl group and a diethylaminoethyl group. Examples of the group having a group having an oxygen atom as a substituent include methoxymethyl Group, alkoxyalkyl group such as methoxyethyl group, ethoxymethyl group, ethoxyethyl group and the like, and groups having a silicon atom as a substituent include trialkylsilylalkyl groups such as trimethylsilylmethyl group, etc. I can give you.

Examples of the substituted silyl group of R ¹⁰ and R ¹¹ include a trialkylsilyl group such as a trimethylsilyl group, a triethylsilyl group, and a t-butyldimethylsilyl group.

The group to which R ¹⁰ and R ¹¹ are bonded is a divalent group having 1 to 12 carbon atoms that may have at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom and a silicon atom. Group. For example, an alkylene group such as a trimethylene group, a tetramethylene group, a pentamethylene group, and a hexamethylene group; an oxydialkylene group such as an oxydiethylene group and an oxydipropylene group; and —CH ₂ CH ₂ —NH—CH ₂ — And a nitrogen-containing group such as a group represented by —CH ₂ CH ₂ —N═CH—.

The group to which R ¹⁰ and R ¹¹ are bonded is preferably a nitrogen-containing group, a group represented by —CH ₂ CH ₂ —NH—CH ₂ —, a group represented by —CH ₂ CH ₂ —N═CH—. Is more preferable.

The hydrocarbyl group of R ¹⁰ and R ¹¹ is preferably an alkyl group, more preferably an alkyl group having 1 to 4 carbon atoms, further preferably a methyl group, an ethyl group, an n-propyl group, or an n-butyl group, Group, n-butyl group is particularly preferred. The substituted hydrocarbyl group for R ¹⁰ and R ¹¹ is preferably an alkoxyalkyl group, more preferably an alkoxyalkyl group having 1 to 4 carbon atoms. The substituted silyl group for R ¹⁰ and R ¹¹ is preferably a trialkylsilyl group, and more preferably a trimethylsilyl group.

R ¹⁰ and R ¹¹ are preferably an alkyl group, an alkoxyalkyl group, a substituted silyl group, or a nitrogen-containing group to which R ¹⁰ and R ¹¹ are bonded, more preferably an alkyl group, still more preferably carbon. It is an alkyl group having 1 to 4 atoms, and more preferably a methyl group, an ethyl group, an n-propyl group, or an n-butyl group.

Examples of the group represented by the formula (IVa) include an acyclic amino group and a cyclic amino group.

Examples of the acyclic amino group include dimethylamino group, diethylamino group, di (n-propyl) amino group, di (isopropyl) amino group, di (n-butyl) amino group, di (sec-butyl) amino group, di ( dialkylamino groups such as tert-butyl) amino group, di (neopentyl) amino group, ethylmethylamino group; di (methoxymethyl) amino group, di (methoxyethyl) amino group, di (ethoxymethyl) amino group, di ( And di (alkoxyalkyl) amino groups such as ethoxyethyl) amino group; and di (trialkylsilyl) amino groups such as di (trimethylsilyl) amino group and di (t-butyldimethylsilyl) amino group.

Examples of the cyclic amino group include 1-pyrrolidinyl group, 1-piperidino group, 1-hexamethyleneimino group, 1-heptamethyleneimino group, 1-octamethyleneimino group, 1-decamethyleneimino group, 1-dodecamethyleneimino. 1-polymethyleneimino groups such as groups can be mentioned. Examples of the cyclic amino group include 1-imidazolyl group, 4,5-dihydro-1-imidazolyl group, 1-imidazolidinyl group, 1-piperazinyl group, morpholino group and the like.

The group represented by the formula (IVa) is preferably an acyclic amino group, more preferably a dialkylamino group, and still more preferably 1 to 1 carbon atoms from the viewpoint of economy and availability. A dialkylamino group substituted with 4 alkyl groups, and more preferably a dimethylamino group, a diethylamino group, a di (n-propyl) amino group, and a di (n-butyl) amino group.

Examples of the hydrocarbyl group of X ^{4 to} X ^{6 in} the formula (IV) include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, and tert-butyl group. be able to. Examples of the substituted hydrocarbyl group include alkoxyalkyl groups such as a methoxymethyl group, an ethoxymethyl group, a methoxyethyl group, and an ethoxyethyl group.

The hydrocarbyl group of X ^{4 to} X ⁶ is preferably an alkyl group, more preferably an alkyl group having 1 to 4 carbon atoms, and still more preferably a methyl group or an ethyl group. Furthermore, the substituted hydrocarbyl group X ⁴ to X ^6, preferably an alkoxyalkyl group, more preferably an alkoxyalkyl group having 1 to 4 carbon atoms.

The hydrocarbyl group and substituted hydrocarbyl group of X ^{4 to} X ⁶ are preferably an alkyl group or an alkoxyalkyl group, and more preferably an alkyl group having 1 to 4 carbon atoms or an alkyl group having 1 to 4 carbon atoms. It is an alkoxyalkyl group, more preferably an alkyl group having 1 to 4 carbon atoms, and still more preferably a methyl group or an ethyl group.

At least one of X ⁴ , X ⁵ and X ^{6 in} the formula (IV) is a group represented by the formula (IVa). Preferably, two or more of X ⁴ , X ⁵ and X ⁶ are groups represented by formula (IVa), more preferably two of X ⁴ , X ⁵ and X ⁶ are represented by formula (IVa) It is a group represented.

As the vinyl compound represented by formula (IV) used in (Step A), one of X ^{4 to} X ⁶ is an acyclic amino group represented by formula (IVa), and two are hydrocarbyl groups or substituted hydrocarbyls. Examples of the group-containing compound include (dialkylamino) dialkylvinylsilane, {di (trialkylsilyl) amino} dialkylvinylsilane, (dialkylamino) dialkoxyalkylvinylsilane, and the like.

(Dialkylamino) dialkylvinylsilane includes (dimethylamino) dimethylvinylsilane, (ethylmethylamino) dimethylvinylsilane, (diethylamino) dimethylvinylsilane, (ethyl-n-propylamino) dimethylvinylsilane, (ethylisopropylamino) dimethylvinylsilane, ( Di (n-propyl) amino) dimethylvinylsilane, (diisopropylamino) dimethylvinylsilane, (n-butyl-n-propylamino) dimethylvinylsilane, (di (n-butyl) amino) dimethylvinylsilane,
(Dimethylamino) diethylvinylsilane, (ethylmethylamino) diethylvinylsilane, (diethylamino) diethylvinylsilane, (ethyl-n-propylamino) diethylvinylsilane, (ethylisopropylamino) diethylvinylsilane, (di (n-propyl) amino) diethyl Vinylsilane, (diisopropylamino) diethylvinylsilane, (n-butyl-n-propylamino) diethylvinylsilane, (di (n-butyl) amino) diethylvinylsilane,
(Dimethylamino) dipropylvinylsilane, (ethylmethylamino) dipropylvinylsilane, (diethylamino) dipropylvinylsilane, (ethyl-n-propylamino) dipropylvinylsilane, (ethylisopropylamino) dipropylvinylsilane, (di (n- Propyl) amino) dipropylvinylsilane, (diisopropylamino) dipropylvinylsilane, (n-butyl-n-propylamino) dipropylvinylsilane, (di (n-butyl) amino) dipropylvinylsilane,
(Dimethylamino) dibutylvinylsilane, (ethylmethylamino) dibutylvinylsilane, (diethylamino) dibutylvinylsilane, (ethyl-n-propylamino) dibutylvinylsilane, (ethylisopropylamino) dibutylvinylsilane, (di (n-propyl) amino) dibutyl Examples include vinylsilane, (diisopropylamino) dibutylvinylsilane, (n-butyl-n-propylamino) dibutylvinylsilane, (di (n-butyl) amino) dibutylvinylsilane, and the like.

As {di (trialkylsilyl) amino} dialkylvinylsilane, {di (trimethylsilyl) amino} dimethylvinylsilane, {di (t-butyldimethylsilyl) amino} dimethylvinylsilane, {di (trimethylsilyl) amino} diethylvinylsilane, {di (T-butyldimethylsilyl) amino} diethylvinylsilane and the like.

(Dialkylamino) dialkoxyalkylvinylsilane includes (dimethylamino) dimethoxymethylvinylsilane, (dimethylamino) dimethoxyethylvinylsilane, (dimethylamino) diethoxymethylvinylsilane, (dimethylamino) diethoxyethylvinylsilane, (diethylamino) dimethoxymethyl Examples thereof include vinylsilane, (diethylamino) dimethoxyethylvinylsilane, (diethylamino) diethoxymethylvinylsilane, (diethylamino) diethoxyethylvinylsilane, and the like.

Compounds in which two of X ^{4 to} X ⁶ are acyclic amino groups represented by the formula (IVa) and one is a hydrocarbyl group or a substituted hydrocarbyl group include bis (dialkylamino) alkylvinylsilane, bis {di (tri Alkylsilyl) amino} alkylvinylsilane, bis (dialkylamino) alkoxyalkylvinylsilane, and the like.

Examples of bis (dialkylamino) alkylvinylsilane include bis (dimethylamino) methylvinylsilane, bis (ethylmethylamino) methylvinylsilane, bis (diethylamino) methylvinylsilane, bis (ethyl-n-propylamino) methylvinylsilane, and bis (ethylisopropyl). Amino) methylvinylsilane, bis (di (n-propyl) amino) methylvinylsilane, bis (diisopropylamino) methylvinylsilane, bis (n-butyl-n-propylamino) methylvinylsilane, bis (di (n-butyl) amino) Methyl vinyl silane,
Bis (dimethylamino) ethylvinylsilane, bis (ethylmethylamino) ethylvinylsilane, bis (diethylamino) ethylvinylsilane, bis (ethyl-n-propylamino) ethylvinylsilane, bis (ethylisopropylamino) ethylvinylsilane, bis (di (n -Propyl) amino) ethylvinylsilane, bis (diisopropylamino) ethylvinylsilane, bis (n-butyl-n-propylamino) ethylvinylsilane, bis (di (n-butyl) amino) ethylvinylsilane,
Bis (dimethylamino) propylvinylsilane, bis (ethylmethylamino) propylvinylsilane, bis (diethylamino) propylvinylsilane, bis (ethyl-n-propylamino) propylvinylsilane, bis (ethylisopropylamino) propylvinylsilane, bis (di (n -Propyl) amino) propylvinylsilane, bis (diisopropylamino) propylvinylsilane, bis (n-butyl-n-propylamino) propylvinylsilane, bis (di (n-butyl) amino) propylvinylsilane,
Bis (dimethylamino) butylvinylsilane, bis (ethylmethylamino) butylvinylsilane, bis (diethylamino) butylvinylsilane, bis (ethyl-n-propylamino) butylvinylsilane, bis (ethylisopropylamino) butylvinylsilane, bis (di (n -Propyl) amino) butylvinylsilane, bis (diisopropylamino) butylvinylsilane, bis (n-butyl-n-propylamino) butylvinylsilane, bis (di (n-butyl) amino) butylvinylsilane, and the like.
As bis {di (trialkylsilyl) amino} alkylvinylsilane, bis {di (trimethylsilyl) amino} methylvinylsilane, bis {di (t-butyldimethylsilyl) amino} methylvinylsilane, bis {di (trimethylsilyl) amino} ethyl Examples include vinyl silane and bis {di (t-butyldimethylsilyl) amino} ethyl vinyl silane.

Examples of bis (dialkylamino) alkoxyalkylvinylsilane include bis (dimethylamino) methoxymethylvinylsilane, bis (dimethylamino) methoxyethylvinylsilane, bis (dimethylamino) ethoxymethylvinylsilane, bis (dimethylamino) ethoxyethylvinylsilane,
Examples thereof include bis (diethylamino) methoxymethylvinylsilane, bis (diethylamino) methoxyethylvinylsilane, bis (diethylamino) ethoxymethylvinylsilane, and bis (diethylamino) ethoxyethylvinylsilane.

Examples of the compound in which three of X ^{4 to} X ⁶ are acyclic amino groups represented by the formula (IVa) include tri (dialkylamino) vinylsilane.
For example, tri (dimethylamino) vinylsilane, tri (ethylmethylamino) vinylsilane, tri (diethylamino) vinylsilane, tri (ethylpropylamino) vinylsilane, tri (dipropylamino) vinylsilane, tri (butylpropylamino) vinylsilane Can do.

Compounds in which two of X ^{4 to} X ⁶ are cyclic amino groups represented by the formula (IVa) and one is a hydrocarbyl group or a substituted hydrocarbyl group include bis (morpholino) methylvinylsilane, bis (piperidino) methylvinylsilane, bis (4,5-dihydroimidazolyl) methylvinylsilane, bis (hexamethyleneimino) methylvinylsilane and the like can be mentioned.

As the vinyl compound represented by the formula (IV) in which two of X ⁴ , X ⁵ and X ⁶ are groups represented by the formula (IVa), preferably two of X ⁴ , X ⁵ and X ⁶ are acyclic A vinyl compound that is an amino group, and is preferably bis (dialkylamino) alkylvinylsilane, more preferably bis (dimethylamino) from the viewpoint of fuel economy, wet grip performance, abrasion resistance, and rubber strength. Methyl vinyl silane, bis (diethylamino) methyl vinyl silane, bis (di (n-propyl) amino) methyl vinyl silane, bis (di (n-butyl) amino) methyl vinyl silane. Among these, bis (diethylamino) methylvinylsilane and bis (di (n-butyl) amino) methylvinylsilane are preferable from the viewpoint of availability of the compound.

In (Step A), polymerization may be performed by combining the conjugated diene and the vinyl compound represented by the formula (IV) with another monomer. Examples of other monomers include aromatic vinyl, vinyl nitrile, and unsaturated carboxylic acid ester. Examples of the aromatic vinyl include styrene, α-methylstyrene, vinyl toluene, vinyl naphthalene, divinyl benzene, trivinyl benzene, and divinyl naphthalene. Examples of the vinyl nitrile include acrylonitrile, and examples of the unsaturated carboxylic acid ester include methyl acrylate, ethyl acrylate, methyl methacrylate, and ethyl methacrylate. Among these, aromatic vinyl is preferable, and styrene is more preferable.

Polymerization in (Step A) is an agent that adjusts the vinyl bond amount of the conjugated diene unit, and an agent that adjusts the distribution of constituent units based on monomers other than the conjugated diene unit and the conjugated diene in the conjugated diene polymer chain. (Hereinafter collectively referred to as “regulator”) or the like. Examples of such agents include ether compounds, tertiary amines, and phosphine compounds. Examples of the ether compound include cyclic ethers such as tetrahydrofuran, tetrahydropyran, and 1,4-dioxane; aliphatic monoethers such as diethyl ether and dibutyl ether; ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, and diethylene glycol diethyl ether. And aliphatic diethers such as diethylene glycol dibutyl ether; aromatic ethers such as diphenyl ether and anisole. Examples of the tertiary amine include triethylamine, tripropylamine, tributylamine, N, N, N ′, N′-tetramethylethylenediamine, N, N-diethylaniline, pyridine, quinoline and the like. Examples of the phosphine compound include trimethylphosphine, triethylphosphine, triphenylphosphine, and the like. These may be used alone or in combination of two or more.

The polymerization temperature in (Step A) is usually 25 to 100 ° C, preferably 35 to 90 ° C. More preferably, it is 50-80 degreeC. The polymerization time is usually 10 minutes to 5 hours.

In (Step B), the amount of the compound having a group represented by the formula (II) to be brought into contact with the polymer prepared in Step A is usually 0.1 to 1 mol of alkali metal derived from the alkali metal catalyst. 3 moles, preferably 0.5-2 moles, more preferably 0.7-1.5 moles.

In (Step B), the temperature at which the polymer prepared in Step A is brought into contact with the compound having a group represented by formula (II) is usually 25 to 100 ° C., preferably 35 to 90 ° C. . More preferably, it is 50-80 degreeC. The contact time is usually 60 seconds to 5 hours, preferably 5 minutes to 1 hour, more preferably 15 minutes to 1 hour.

In the method for producing the conjugated diene polymer, a coupling agent may be added to the hydrocarbon solution of the conjugated diene polymer in the polymerization termination from the start of polymerization of the monomer using an alkali metal catalyst, if necessary. Good. An example of the coupling agent is a compound represented by the following formula (V).
R ¹² _a ML _4-a (V)
[Wherein, R ¹² represents an alkyl group, an alkenyl group, a cycloalkenyl group or an aromatic residue, M represents a silicon atom or a tin atom, L represents a halogen atom or a hydrocarbyloxy group, and a represents 0 to 2 Represents an integer. ]
Here, the aromatic residue represents a monovalent group obtained by removing hydrogen bonded to an aromatic ring from an aromatic hydrocarbon.

As the coupling agent represented by the formula (V), silicon tetrachloride, methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, tin tetrachloride, methyltrichlorotin, dimethyldichlorotin, trimethylchlorotin, tetramethoxysilane, methyl Examples include trimethoxysilane, dimethoxydimethylsilane, methyltriethoxysilane, ethyltrimethoxysilane, dimethoxydiethylsilane, diethoxydimethylsilane, tetraethoxysilane, ethyltriethoxysilane, and diethoxydiethylsilane.

The addition amount of the coupling agent is preferably 0.03 mol or more, more preferably 0.05 mol or more, from the viewpoint of processability of the conjugated diene polymer per 1 mol of alkali metal derived from the alkali metal catalyst. is there. Moreover, from a viewpoint of low fuel consumption, Preferably it is 0.4 mol or less, More preferably, it is 0.3 mol or less.

Conjugated diene polymers can be collected by known recovery methods, for example, (1) a method of adding a coagulant to a hydrocarbon solution of a conjugated diene polymer, and (2) adding steam to a hydrocarbon solution of a conjugated diene polymer. By this method, the conjugated diene polymer can be recovered from the hydrocarbon solution. The recovered conjugated diene polymer may be dried by a known dryer such as a band dryer or an extrusion dryer.

Moreover, in the manufacturing method of the said conjugated diene polymer, it is preferable to perform the process which substitutes the group represented by the formula (Ia) of a polymer by a hydroxyl group by hydrolysis etc. The treatment may be performed in the state of the polymer alone or in the state of the composition as described below. Examples of the hydrolysis method include known methods such as a method by steam stripping. The above-described processing, the X ¹ to X ³ in the formula (I) may be a hydroxyl group, fuel economy, wet grip performance, abrasion resistance and rubber strength can be further improved with good balance.

The conjugated diene polymer can be used in the rubber composition of the present invention as a rubber component, and is preferably used in combination with other rubber components and additives.

Examples of other rubber components include conventional styrene-butadiene copolymer rubber, polybutadiene rubber (BR), butadiene-isoprene copolymer rubber, and butyl rubber. Moreover, natural rubber (NR), an ethylene-propylene copolymer, an ethylene-octene copolymer, and the like can be given. Two or more of these rubber components may be used in combination. Among them, it is preferable to use NR and / or BR, and more preferable to use both components of NR and BR from the viewpoint that fuel economy, wet grip performance, wear resistance and rubber strength can be improved in a well-balanced manner. .

The content of the conjugated diene polymer in 100% by mass of the rubber component is preferably 5% by mass or more, more preferably 10% by mass or more, still more preferably 30% by mass or more, and particularly preferably 50% by mass or more. When the content of the conjugated diene polymer is less than 5% by mass, there is a tendency that an improvement effect of low fuel consumption is difficult to obtain. The content of the conjugated diene polymer is preferably 90% by mass or less, more preferably 80% by mass or less, and still more preferably 70% by mass or less. When the content of the conjugated diene polymer exceeds 90% by mass, the wear resistance is lowered and the cost tends to be high.

NR is not particularly limited, and, for example, SIR20, RSS # 3, TSR20, deproteinized natural rubber (DPNR), high purity natural rubber (HPNR), and the like can be used in the tire industry.

The content of NR in 100% by mass of the rubber component is preferably 5% by mass or more, more preferably 15% by mass or more. If it is less than 5% by mass, the wear resistance tends to decrease. The NR content is preferably 70% by mass or less, more preferably 30% by mass or less. If it exceeds 70% by mass, the wet grip performance tends to decrease.

The BR is not particularly limited. For example, BR1220 manufactured by Nippon Zeon Co., Ltd., BR130B manufactured by Ube Industries, Ltd. Commonly used in the tire industry such as BR containing syndiotactic polybutadiene crystals can be used.

The content of BR in 100% by mass of the rubber component is preferably 5% by mass or more, more preferably 15% by mass or more. If it is less than 5% by mass, the wear resistance tends to decrease. The BR content is preferably 60% by mass or less, more preferably 30% by mass or less. If it exceeds 60% by mass, the wet grip performance tends to decrease.

The total content of NR and BR in 100% by mass of the rubber component is preferably 10% by mass or more, more preferably 30% by mass or more. If it is less than 10% by mass, the wear resistance tends to decrease. The total content is preferably 70% by mass or less, more preferably 50% by mass or less. If it exceeds 70% by mass, the wet grip performance tends to decrease.

［式中、Ｗは炭素数２〜１０のアルキレン基、Ｒ^１３及びＲ^１４は、同一若しくは異なって、窒素原子を含む１価の有機基を表す。］ In the present invention, a compound represented by the following formula (1) is used. Thereby, a CC bond with high binding energy and high thermal stability can be retained in the rubber composition.

[Wherein, W represents an alkylene group having 2 to 10 carbon atoms, and R ¹³ and R ¹⁴ are the same or different and each represents a monovalent organic group containing a nitrogen atom. ]

The alkylene group for W (having 2 to 10 carbon atoms) is not particularly limited, and includes linear, branched, and cyclic groups. Among these, a linear alkylene group is preferable. As for carbon number, 4-8 are preferred. When the number of carbon atoms in the alkylene group is 1, thermal stability tends to be poor, and there is a tendency that the effect of having an alkylene group cannot be obtained. It tends to be difficult to form a crosslinked chain represented by

Examples of the alkylene group satisfying the above conditions include ethylene group, trimethylene group, tetramethylene group, pentamethylene group, hexamethylene group, heptamethylene group, octamethylene group, decamethylene group and the like. Among these, a hexamethylene group is preferable because a cross-link represented by -S-SWS-SS- is smoothly formed between the polymers and is thermally stable.

R ¹³ and R ¹⁴ are not particularly limited as long as they are monovalent organic groups containing a nitrogen atom, but those containing at least one aromatic ring are preferred, and N—C (═S) in which a carbon atom is bonded to a dithio group. )-Is more preferable. R ¹³ and R ¹⁴ may be the same or different, but are preferably the same for reasons such as ease of production.

Examples of the compound represented by the formula (1) include 1,2-bis (N, N′-dibenzylthiocarbamoyldithio) ethane and 1,3-bis (N, N′-dibenzylthiocarbamoyldithio). Propane, 1,4-bis (N, N′-dibenzylthiocarbamoyldithio) butane, 1,5-bis (N, N′-dibenzylthiocarbamoyldithio) pentane, 1,6-bis (N, N ′) -Dibenzylthiocarbamoyldithio) hexane, 1,7-bis (N, N'-dibenzylthiocarbamoyldithio) heptane, 1,8-bis (N, N'-dibenzylthiocarbamoyldithio) octane, 1,9 -Bis (N, N′-dibenzylthiocarbamoyldithio) nonane, 1,10-bis (N, N′-dibenzylthiocarbamoyldithio) decane and the like. Among these, 1,6-bis (N, N′-dibenzylthiocarbamoyldithio) hexane is preferable because it is thermally stable and has excellent polarizability.

The content of the compound represented by the formula (1) is preferably 5 parts by mass or more, more preferably 6 parts by mass or more with respect to 100 parts by mass of the rubber component. If it is less than 5 parts by mass, the effect of adding the compound represented by formula (1) may not be sufficiently obtained. The content is preferably 23 parts by mass or less, more preferably 8 parts by mass or less. When it exceeds 23 parts by mass, the crosslinking density becomes too high, and the wear resistance may be deteriorated.

The rubber composition of the present invention is characterized by compounding silica as a reinforcing agent. 5-150 mass parts is preferable with respect to 100 mass parts of rubber components, and, as for the compounding quantity (content) of silica, 10-100 mass parts is more preferable. If the amount of silica is less than 5 parts by mass, the wear resistance tends to be insufficient, while if the amount of silica exceeds 150 parts by mass, the workability tends to deteriorate. Silica may be used alone or in combination of two or more.

The content of silica in a total of 100% by mass of silica and carbon black is preferably 60% by mass or more, more preferably 85% by mass or more, preferably 98% by mass or less, more preferably 95% by mass or less. . If it is in the said range, low-fuel-consumption property, wet grip performance, abrasion resistance, and rubber | gum strength can be improved in a high dimension and with sufficient balance.

Further, the nitrogen adsorption specific surface area (N ₂ SA) of silica is preferably 40 to 400 m ² / g, and particularly preferably 150 to ²⁰⁰ m ² / g. Silica having a nitrogen adsorption specific surface area of less than 40 m ² / g has a small reinforcing effect and tends to have low wear resistance, and silica exceeding 400 m ² / g has poor dispersibility, increased hysteresis loss, and low fuel consumption. There is a tendency to decrease.

Known additives can be used, such as sulfur vulcanizing agents; thiazole vulcanization accelerators, thiuram vulcanization accelerators, sulfenamide vulcanization accelerators, guanidine vulcanization accelerators. Vulcanization accelerators such as stearic acid and zinc oxide; organic peroxides; fillers such as carbon black, calcium carbonate, talc, alumina, clay, aluminum hydroxide, mica; silane coupling Agents; processing aids such as extender oils and lubricants; anti-aging agents can be exemplified.

Examples of the silane coupling agent include sulfide, mercapto, vinyl, amino, glycidoxy, nitro, and chloro silane coupling agents. Among them, bis (3-triethoxysilylpropyl) tetrasulfide, bis (2-triethoxysilylethyl) tetrasulfide, bis (3-triethoxysilylpropyl) disulfide, bis (2-triethoxysilylethyl) disulfide, etc. A sulfide system is preferred, and bis (3-triethoxysilylpropyl) tetrasulfide is more preferred. Here, the content of the silane coupling agent is preferably 3 to 20 parts by mass with respect to 100 parts by mass of silica.

Examples of the carbon black include furnace black (furness carbon black) such as SAF, ISAF, HAF, MAF, FEF, SRF, GPF, APF, FF, CF, SCF and ECF; acetylene black (acetylene carbon black); FT and Examples thereof include thermal black (thermal carbon black) such as MT; channel black (channel carbon black) such as EPC, MPC and CC; graphite and the like. These can be used alone or in combination of two or more.

The nitrogen adsorption specific surface area _(N 2 SA) of carbon black is usually 5 to 200 m ² / g, the lower limit is preferably ^{50 m} 2 / g, the upper limit is 150 meters ² / g. Carbon black has a dibutyl phthalate (DBP) absorption amount of usually 5 to 300 ml / 100 g, preferably a lower limit of 80 ml / 100 g and an upper limit of 180 ml / 100 g. If the N ₂ SA or DBP absorption amount of the carbon black is less than the lower limit of the above range, the reinforcing effect tends to be small and the wear resistance tends to decrease. If the upper limit of the above range is exceeded, dispersibility is poor and hysteresis loss increases. There is a tendency for fuel efficiency to decrease. The nitrogen adsorption specific surface area is measured according to ASTM D4820-93, and the DBP absorption is measured according to ASTM D2414-93. As a commercially available product, Tokai Carbon Co., Ltd. trade name SHIEST 6, SEAST 7HM, SEAST KH, Evonik Degussa trade name CK3, Special Black 4A, etc. can be used.

Examples of the sulfur include powdered sulfur, precipitated sulfur, colloidal sulfur, insoluble sulfur, and highly dispersible sulfur.

The sulfur content is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more with respect to 100 parts by mass of the rubber component. If it is less than 0.1 parts by mass, the vulcanization rate will be slow, and the productivity may be deteriorated. The content is preferably 7 parts by mass or less, more preferably 1 part by mass or less. If it exceeds 7 parts by mass, the rubber physical property change after aging may be increased.

When sulfur is used in the rubber composition of the present invention, the total content of sulfur and the compound represented by the formula (1) is preferably 5 parts by mass or more, more preferably, 100 parts by mass of the rubber component. 7 parts by mass or more. The total content is preferably 25 parts by mass or less, more preferably 10 parts by mass or less. By setting it within the above range, a good cross-linked structure is formed, and the effects of the present invention can be obtained satisfactorily.

Examples of the extending oil include aromatic mineral oil (viscosity specific gravity constant (VGC value) 0.900 to 1.049), naphthenic mineral oil (VGC value 0.850 to 0.899), paraffinic mineral oil (VGC value 0.790 to 0.849), and the like. The polycyclic aromatic content of the extender oil is preferably less than 3% by mass, more preferably less than 1% by mass. The polycyclic aromatic content is measured according to the British Petroleum Institute 346/92 method. Moreover, the aromatic compound content (CA) of the extending oil is preferably 20% by mass or more. These extending oils may be used in combination of two or more.

Examples of the vulcanization accelerator include 2-mercaptobenzothiazole, dibenzothiazyl disulfide, and thiazole vulcanization accelerators such as N-cyclohexyl-2-benzothiazylsulfenamide; tetramethylthiuram monosulfide, tetramethylthiuram. Thiuram vulcanization accelerators such as disulfides; N-cyclohexyl-2-benzothiazole sulfenamide, Nt-butyl-2-benzothiazole sulfenamide, N-oxyethylene-2-benzothiazole sulfenamide, N -Sulfenamide vulcanization accelerators such as oxyethylene-2-benzothiazole sulfenamide and N, N'-diisopropyl-2-benzothiazole sulfenamide; diphenylguanidine, diortolylguanidine, orthotolylbiguanidine What guanidine-based vulcanization accelerator can be mentioned, its amount is preferably from 0.1 to 5 parts by mass with respect to 100 parts by mass of the rubber component, more preferably from 0.2 to 3 parts by weight.

As a method for producing a rubber composition by blending the conjugated diene polymer with other rubber components or additives, a known method, for example, using a known mixer such as a roll or a banbury for each component. A kneading method can be used.

As kneading conditions, when additives other than the vulcanizing agent and the vulcanization accelerator are blended, the kneading temperature is usually 50 to 200 ° C., preferably 80 to 190 ° C., and the kneading time is usually 30 seconds. -30 minutes, preferably 1-30 minutes.
When blending a vulcanizing agent and a vulcanization accelerator, the kneading temperature is usually 100 ° C. or lower, preferably room temperature to 80 ° C. A composition containing a vulcanizing agent and a vulcanization accelerator is usually used after vulcanization treatment such as press vulcanization. The vulcanization temperature is usually 120 to 200 ° C, preferably 140 to 180 ° C.

The rubber composition of the present invention is excellent in balance between low fuel consumption, wet grip performance, abrasion resistance and rubber strength, and can provide a remarkable improvement effect of these performances.

The rubber composition of the present invention can be suitably used for each member of a tire, and can be particularly suitably used for a tread.

The pneumatic tire of the present invention can be produced by a usual method using the rubber composition. That is, a rubber composition containing various additives as necessary is extruded according to the shape of a tire tread, etc. at an unvulcanized stage, and molded by a normal method on a tire molding machine, It can be bonded together with other tire members to form an unvulcanized tire. This unvulcanized tire can be heated and pressurized in a vulcanizer to produce the pneumatic tire of the present invention.

The pneumatic tire of the present invention can be suitably used as a tire for passenger cars and a tire for trucks and buses (heavy load tire).

Hereinafter, the present invention will be described by way of examples.
The physical properties were evaluated by the following method. In the following evaluation, Comparative Example 1 was used as a reference comparative example.

1. Vinyl bond amount (unit: mol%)
The amount of vinyl bonds in the polymer was determined from the absorption intensity near 910 cm ^−1, which is the absorption peak of the vinyl group, by infrared spectroscopy.

2. Styrene unit content (unit: mass%)
According to JIS K6383 (1995), the content of styrene units in the polymer was determined from the refractive index.

3. Molecular weight distribution (Mw / Mn)
The weight average molecular weight (Mw) and number average molecular weight (Mn) were measured by gel permeation chromatography (GPC) method under the following conditions (1) to (8). And the molecular weight distribution (Mw / Mn) of the polymer was calculated | required from measured Mw and Mn.
(1) Apparatus: HLC-8020 manufactured by Tosoh Corporation
(2) Separation column: Tosoh GMH-XL (two in series)
(3) Measurement temperature: 40 ° C
(4) Carrier: Tetrahydrofuran (5) Flow rate: 0.6 mL / min (6) Injection volume: 5 μL
(7) Detector: Differential refraction (8) Molecular weight standard: Standard polystyrene

4). tan δ
A strip-shaped test piece having a width of 1 mm or 2 mm and a length of 40 mm was punched out of the sheet-like vulcanized rubber composition and subjected to the test. Using a spectrometer manufactured by Ueshima Seisakusho, tan δ was measured at a dynamic strain amplitude of 1%, a frequency of 10 Hz, and a temperature of 50 ° C. The reciprocal value of tan δ was expressed as an index with the reference comparative example being 100. The larger the value, the lower the rolling resistance and the lower the fuel consumption.

5. Using a rolling resistance rolling resistance tester, the rolling resistance when the test tire is run at a rim (15 × 6JJ), internal pressure (230 kPa), load (3.43 kN), speed (80 km / h) is measured, It was displayed as an index when the reference comparative example was 100. A larger index is better (low fuel consumption).

6). Wet grip performance Each test tire was mounted on all wheels of a vehicle (domestic FF2000cc), and a braking distance from an initial speed of 100 km / h was determined on a wet asphalt road surface. The result is expressed as an index. The larger the number, the better the wet skid performance (wet grip performance). The index was calculated by the following formula.
Wet skid performance = (braking distance of reference comparative example) / (braking distance of each example or comparative example) × 100

7). LAT abrasion test Using a LAT tester (Laboratory Ablation and Skid Tester), the volume loss of each vulcanized rubber composition was measured under the conditions of a load of 50 N, a speed of 20 km / h, and a slip angle of 5 °. The numerical values (wear resistance index) in Table 2 are relative values when the volume loss amount of the reference comparative example is 100. The larger the value, the better the wear resistance.

8). Rubber strength According to JIS-K 6251 (2010) "Vulcanized rubber and thermoplastic rubber-Determination of tensile properties" Tensile test using No. 3 dumbbell type rubber test piece made of sheet vulcanized rubber composition The modulus at break (TB) (MPa) and the elongation at break (EB) (%) were measured. Then, the rubber strength (TB × EB / 2) of the reference comparative example was set to 100, and the rubber strength of each blend was indicated by an index according to the following calculation formula. The larger the rubber strength index, the better the fracture strength.
(Rubber strength index) = (Rubber strength of each compound) / (Rubber strength of reference comparative example) × 100

Production Example 1 (Synthesis of Polymer 1)
It washed 20 liter stainless steel polymerization reactor, and dried, flushed with dry nitrogen, hexane (specific gravity 0.68g ^/ cm 3) 10.2kg, 1,3- butadiene 547 g, styrene 173 g, tetrahydrofuran 6. 1 ml and ethylene glycol diethyl ether 5.0 ml were charged into the polymerization reactor. Next, 11.5 mmol of bis (diethylamino) methylvinylsilane and 14.1 mmol of n-butyllithium were added as a cyclohexane solution and an n-hexane solution, respectively, to initiate polymerization.
The stirring rate was 130 rpm, the temperature in the polymerization reactor was 65 ° C., and 1,3-butadiene and styrene were copolymerized for 3 hours while continuously supplying the monomer into the polymerization reactor. The supply amount of 1,3-butadiene in the total polymerization was 821 g, and the supply amount of styrene was 259 g.
Next, the obtained polymer solution was stirred at a stirring speed of 130 rpm, 11.5 mmol of N, N-dimethylformamide dimethylacetal was added, and the mixture was stirred for 15 minutes. 20 ml of hexane solution containing 0.54 ml of methanol was added to the polymer solution, and the polymer solution was further stirred for 5 minutes.

2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilyzer GM) was added to the polymer solution. 8 g, 0.9 g of pentaerythrityl tetrakis (3-laurylthiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer TP-D) was added, and then the polymer was removed from the polymer solution by steam stripping. 1 was recovered. The evaluation results of the polymer 1 are shown in Table 1. In addition, the content of the structural unit represented by the formula (I) in the polymer calculated from the input amount and the supply amount of the raw material into the polymerization reactor is 0.006 mmol / g polymer per polymer unit mass. there were.

Production Example 2 (Synthesis of Polymer 2)
It washed 20 liter stainless steel polymerization reactor, and dried, flushed with dry nitrogen, hexane (specific gravity 0.68g ^/ cm 3) 10.2kg, 1,3- butadiene 547 g, styrene 173 g, tetrahydrofuran 6. 1 ml and ethylene glycol diethyl ether 5.0 ml were charged into the polymerization reactor. Next, 14.1 mmol of n-butyllithium was added as an n-hexane solution, and 1,3-butadiene and styrene were copolymerized for 1 hour. During the polymerization, the stirring speed was 130 rpm, the temperature in the polymerization reactor was 65 ° C., and the monomer was continuously fed into the polymerization reactor.
After the polymerization for 1 hour, 11.0 mmol of bis (diethylamino) methylvinylsilane was added as a cyclohexane solution, and the mixture was charged into the polymerization reactor under the conditions of a stirring speed of 130 rpm and a polymerization reactor temperature of 65 ° C.
Next, the monomer was continuously supplied into the polymerization reactor, and 1,3-butadiene and styrene were copolymerized for 0.5 hour. During the polymerization, the stirring speed was 130 rpm, and the temperature in the polymerization reactor was 65 ° C.
After the 0.5 hour polymerization, 11.0 mmol of bis (diethylamino) methylvinylsilane was added as a cyclohexane solution, and the mixture was charged into the polymerization reactor under the conditions of a stirring speed of 130 rpm and a polymerization reactor internal temperature of 65 ° C.
Next, the monomer was continuously supplied into the polymerization reactor, and 1,3-butadiene and styrene were copolymerized for 0.5 hour. During the polymerization, the stirring speed was 130 rpm, and the temperature in the polymerization reactor was 65 ° C.
After the 0.5 hour polymerization, 11.0 mmol of bis (diethylamino) methylvinylsilane was added as a cyclohexane solution, and the mixture was charged into the polymerization reactor under the conditions of a stirring speed of 130 rpm and a polymerization reactor internal temperature of 65 ° C.
Next, the monomer was continuously supplied into the polymerization reactor, and 1,3-butadiene and styrene were copolymerized for 0.5 hour. During the polymerization, the stirring speed was 130 rpm, and the temperature in the polymerization reactor was 65 ° C. The supply amount of 1,3-butadiene in the total polymerization was 821 g, and the supply amount of styrene was 259 g.
Next, the obtained polymer solution was stirred at a stirring speed of 130 rpm, 11.0 mmol of N, N-dimethylformamide dimethylacetal was added, and the mixture was stirred for 15 minutes. 20 ml of hexane solution containing 0.54 ml of methanol was added to the polymer solution, and the polymer solution was further stirred for 5 minutes.

2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilyzer GM) was added to the polymer solution. 8 g, 0.9 g of pentaerythrityl tetrakis (3-laurylthiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer TP-D) was added, and then the polymer was removed from the polymer solution by steam stripping. 2 was recovered. The evaluation results of Polymer 2 are shown in Table 1. In addition, the content of the structural unit represented by the formula (I) in the polymer calculated from the input amount and the supply amount of the raw material into the polymerization reactor is 0.018 mmol / g polymer per polymer unit mass. there were.

Production Example 3 (Synthesis of Polymer 3)
It washed 20 liter stainless steel polymerization reactor, and dried, flushed with dry nitrogen, hexane (specific gravity 0.68g ^/ cm 3) 10.2kg, 1,3- butadiene 547 g, styrene 173 g, tetrahydrofuran 6. 1 ml and ethylene glycol diethyl ether 5.0 ml were charged into the polymerization reactor. Next, 11.5 mmol of bis (diethylamino) methylvinylsilane and 14.1 mmol of n-butyllithium were added as a cyclohexane solution and an n-hexane solution, respectively, to initiate polymerization.
The stirring rate was 130 rpm, the temperature in the polymerization reactor was 65 ° C., and 1,3-butadiene and styrene were copolymerized for 3 hours while continuously supplying the monomer into the polymerization reactor. The supply amount of 1,3-butadiene in the total polymerization was 821 g, and the supply amount of styrene was 259 g.
Next, the obtained polymer solution was stirred at a stirring speed of 130 rpm, 11.5 mmol of N, N-dimethylformamide dimethylacetal was added, and the mixture was stirred for 15 minutes. 20 ml of hexane solution containing 0.54 ml of methanol was added to the polymer solution, and the polymer solution was further stirred for 5 minutes.

2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilyzer GM) was added to the polymer solution. 8 g, 0.9 g of pentaerythrityltetrakis (3-laurylthiopropionate) (manufactured by Sumitomo Chemical Co., Ltd., trade name: Sumilizer TP-D) was added, and then the polymer solution was stirred at room temperature for 24 hours Evaporated and further dried under reduced pressure at 55 ° C. for 12 hours to obtain a polymer 3. The evaluation results of the polymer 3 are shown in Table 1. In addition, the content of the structural unit represented by the formula (I) in the polymer calculated from the input amount and the supply amount of the raw material into the polymerization reactor is 0.006 mmol / g polymer per polymer unit mass. there were.

Below, various chemical | medical agents used by the Example and the comparative example are demonstrated.
Natural rubber: RSS # 3
Butadiene rubber: Ubepol BR150B manufactured by Ube Industries, Ltd.
SBR (non-modified): NS116 manufactured by Nippon Zeon Co., Ltd. (styrene content: 20%, vinyl content: 60%)
Polymers 1-3: Production Examples 1 to 3 above
Silica: Ultrasil VN3-G (N ₂ SA: 175 m ² / g) manufactured by Evonik Degussa
Silane coupling agent: Si69 (bis (3-triethoxysilylpropyl) tetrasulfide) manufactured by Degussa
Carbon black: Dia Black N339 manufactured by Mitsubishi Chemical Corporation (N ₂ SA: 96 m ² / g, DBP absorption: 124 ml / 100 g)
Oil: X-140 manufactured by Japan Energy Co., Ltd.
Anti-aging agent: Antigen 3C manufactured by Sumitomo Chemical Co., Ltd.
Stearic acid: Beads manufactured by NOF Corporation Zinc stearate Zinc oxide: Zinc flower No. 1 manufactured by Mitsui Kinzoku Mining Co., Ltd. Wax: Sunnock N manufactured by Ouchi Shinsei Chemical Co., Ltd.
Sulfur: powder sulfur cross-linking agent manufactured by Tsurumi Chemical Co., Ltd .: Vulcuren VP KA9188 (1,6-bis (N, N′-dibenzylthiocarbamoyldithio) hexane manufactured by LANXESS)
Vulcanization accelerator 1: Soxinol CZ manufactured by Sumitomo Chemical Co., Ltd.
Vulcanization accelerator 2: Soxinol D manufactured by Sumitomo Chemical Co., Ltd.

(Examples and Comparative Examples)
In accordance with the formulation shown in Table 2, materials other than sulfur, a crosslinking agent and a vulcanization accelerator were kneaded for 5 minutes at 150 ° C. using a 1.7 L Banbury mixer manufactured by Kobe Steel, Ltd. A kneaded product was obtained. Next, sulfur, a crosslinking agent, and a vulcanization accelerator were added to the kneaded product obtained, and kneaded for 5 minutes at 80 ° C. using an open roll to obtain an unvulcanized rubber composition. The obtained unvulcanized rubber composition was press vulcanized with a 0.5 mm thick mold at 170 ° C. for 20 minutes to obtain a vulcanized rubber composition.
Further, the obtained unvulcanized rubber composition is molded into a tread shape and bonded together with other tire members on a tire molding machine to form an unvulcanized tire, which is vulcanized at 170 ° C. for 12 minutes, and tested. Tires (size: 195 / 65R15) were manufactured.

The obtained vulcanized rubber composition and test tire were used for evaluation by the above test method. Each test result is shown in Table 2.

As shown in Table 2, the terminal was modified with a compound having a structural unit based on a conjugated diene and a structural unit represented by the above formula (I) and having a group represented by the above formula (II). The rubber composition of the example using the polymer (polymers 1 to 3) and the compound (crosslinking agent) represented by the above formula (1) in combination with the fuel efficiency compared to the rubber composition of the comparative example, Wet grip performance, wear resistance and rubber strength were improved in a well-balanced manner.

Claims (12)

Containing a rubber component, silica and a compound represented by the following formula (1),
Of the 100% by mass of the rubber component, at least a polymer having a structural unit based on a conjugated diene and a structural unit represented by the following formula (I) and having a group represented by the following formula (II): The content of the conjugated diene polymer obtained by modifying one end is 5% by mass or more,
Content of the said silica with respect to 100 mass parts of said rubber components is 5-150 mass parts, The rubber composition characterized by the above-mentioned.

[Wherein, X ¹ , X ² and X ³ each independently represent a group represented by the following formula (Ia), a hydroxyl group, a hydrocarbyl group or a substituted hydrocarbyl group, and at least ^one of X ¹ , X ² and X ³ One is a group or a hydroxyl group represented by the following formula (Ia). ]

[Wherein, R ¹ and R ² independently denote a hydrocarbyl group having 1 to 6 carbon atoms, a substituted hydrocarbyl group having 1-6 carbon atoms, or a substituted silyl group, R ¹ and R ² may be bonded to form a ring structure with the nitrogen atom. ]

[Wherein, m represents an integer of 1 to 11, and A represents a functional group having a nitrogen atom. ]

[Wherein, W represents an alkylene group having 2 to 10 carbon atoms, and R ¹³ and R ¹⁴ are the same or different and each represents a monovalent organic group containing a nitrogen atom. ] The rubber composition according to claim ^1, wherein R ¹ and R ^{2 in} the formula (Ia) are hydrocarbyl groups having 1 to 6 carbon atoms. The rubber composition according to claim 1 or 2, wherein ^two of X ¹ , X ² and X ^{3 in} the formula (I) are a group or a hydroxyl group represented by the formula (Ia). The rubber composition according to any one of claims 1 to 3, wherein the compound having a group represented by the formula (II) is a compound represented by the following formula (III).

[Wherein n represents an integer of 0 to 10, R ³ represents a hydrocarbyl group having 1 to 5 carbon atoms, and R ⁴ , R ⁵ , R ⁶ and R ⁷ each independently represent a hydrogen atom, A hydrocarbyl group having 1 to 5 carbon atoms, a substituted hydrocarbyl group having 1 to 5 carbon atoms or a hydrocarbyloxy group having 1 to 5 carbon atoms, and when there are a plurality of R ⁴ and R ^5, there are plural R ⁴ and a plurality of R ⁵ may be the same or different, and R ⁸ and R ⁹ are each independently at least one selected from the group consisting of a nitrogen atom, an oxygen atom and a silicon atom. atom represents even though a good number of carbon atoms from 1 to 6 groups have, R ⁸ and R ⁹ may form a ring structure with bonded to a nitrogen atom, R ⁸ and R ⁹ are nitrogen It may be the same group bonded by a double bond ] One of R < ⁶ > and R < ⁷ > of Formula (III) is a hydrogen atom, The rubber composition of Claim 4 characterized by the above-mentioned. The vinyl bond content of the conjugated diene polymer is 10 mol% or more and 80 mol% or less, where the content of the constituent unit based on the conjugated diene is 100 mol%. The rubber composition as described in 2. The rubber composition according to claim 1, comprising natural rubber and / or butadiene rubber. The rubber composition according to claim 1, wherein the silica has a nitrogen adsorption specific surface area of 40 to 400 m ² / g. The rubber composition according to any one of claims 1 to 8, wherein the content of the compound represented by the formula (1) with respect to 100 parts by mass of the rubber component is 5 to 23 parts by mass. The rubber composition according to claim 1, comprising 0.1 to 7 parts by mass of sulfur with respect to 100 parts by mass of the rubber component. It is used as a rubber composition for treads, The rubber composition in any one of Claims 1-10 characterized by the above-mentioned. The pneumatic tire produced using the rubber composition in any one of Claims 1-11.