RU2574246C2 - Rubber mix and air tube - Google Patents

Abstract

FIELD: motor car construction.

SUBSTANCE: claimed rubber mix comprises the rubber component and silicon dioxide. Said rubber component contains 30-90 wt % of bonded diene polymer per 100 wt % of the rubber component. Said bonded diene polymer contains the structural unit obtained from the bonded diene and structural unit described by formula (I). Terminal group of the bonded diene polymer is modified by the compound of formula (II). The rubber component contains the extra natural and butadiene rubber. The content of silicon dioxide per 100 wt % of the rubber component makes 10-100 wt %.

EFFECT: better fuel saving and grip with wet road surface, higher wear resistance.

6 cl, 4 tbl, 6 ex

Description

Technical field

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

State of the art

Recently, as environmental protection measures are tightened, requirements for fuel economy of vehicles are becoming more stringent. A certain contribution to fuel economy can also be obtained through the use of car tires made from the corresponding rubber compounds. For example, rubber compounds containing a conjugated diene polymer (e.g., polybutadiene, styrene-butadiene copolymer) and a filler (e.g. carbon black, silica) can be used to make automobile tires.

For example, in patent publication [1], a method for increasing fuel economy is proposed. In this method, diene rubber modified with an organosilicon compound containing an amino group and an alkoxy group is used. However, in the past few years, fuel economy requirements have become even more stringent. Moreover, since some other properties that rubber compounds used for the manufacture of car tires should have, for example, providing good adhesion to tires with wet road surfaces and high abrasion resistance, are usually not consistent with the fuel economy property, an optimal balance between the required properties can be achieved quite difficult.

List of links

Patent Literature

Patent Literature 1: JP 2000-344955 A

SUMMARY OF THE INVENTION

The objective of the present invention is to solve the above problems and provide a rubber composition that provides a good balance of increasing fuel economy, wet grip and abrasion resistance, as well as manufacturing a pneumatic tire from said rubber composition.

The present invention relates to a rubber composition comprising a rubber component and silicon oxide, where the rubber component contains at least 5% by weight, a conjugated diene polymer per 100% by weight, of the rubber component,

the conjugated diene polymer contains a structural unit derived from a conjugated diene and a structural unit represented by the following formula (I):

in which each X ¹ , X ² and X ³ independently represents a group represented by formula (Ia) below, a hydroxyl group, a hydrocarbon group or a substituted hydrocarbon group and at least one of X ¹ , X ² and X ³ is a group represented by the formula ( Ia) or a hydroxyl group:

wherein each R ¹ and R ² independently represents a hydrocarbon group of C _1-6, hydrocarbon group, substituted C _1-6, a silyl group or a substituted silyl group, and R ¹ and R ² may be bonded to each other to form a cyclic structure together with nitrogen atom

moreover, at least one of the end groups of the conjugated diene polymer is modified by a compound represented by the following formula (II):

in which n is an integer from 1 to 10; each R ³ , R ⁴ and R ⁵ independently represents a C _1-4 hydrocarbon group or a C _1-4 hydrocarbyloxy group and at least one of R ³ , R ⁴ and R ⁵ is a hydrocarbyloxy group; and A represents a functional group containing a nitrogen atom, and

where silicon dioxide is contained in an amount of from 5 to 150 parts by weight per 100 parts by weight rubber component.

R ¹ and R ² in the formula (Ia) are preferably C _1-6 hydrocarbon groups.

Two of X ¹ , X ² and X ³ in the formula (I) are preferably selected from the group consisting of the group represented by the formula (Ia) and a hydroxyl group.

And in the formula (II) is preferably a group represented by the following formula (IIa):

in which each R ⁶ and R ⁷ independently represents a group C _1-6 , possibly containing at least one atom selected from the group,

consisting of a nitrogen atom, an oxygen atom and a silicon atom; R ⁶ and R ⁷ may be bonded to each other to form a cyclic structure together with a nitrogen atom; and R ⁶ and R ⁷ can form a single group bonded to nitrogen via a double bond.

The content of vinyl bonds in the conjugated diene polymer is at least 10 mol%, but does not exceed 80 mol%. per 100 mol%. structural units derived from conjugated diene.

The rubber composition preferably includes at least one compound selected from natural rubber and butadiene rubber.

Preferably, silicon dioxide has a specific surface area, determined by the nitrogen adsorption method, from 40 to 400 m ² / g.

The rubber composition is preferably intended to be used as a rubber composition for a tread.

The present invention also relates to a pneumatic tire made from a rubber composition.

According to the present invention, the rubber composition contains a specific conjugated diene polymer and silicon oxide, and a pneumatic tire can be obtained from such a mixture, providing an improved balance of fuel economy, wet grip and galling resistance.

Description of embodiments

The rubber composition according to the present invention contains silicon oxide and a conjugated diene polymer that contains a structural unit derived from a conjugated diene and a structural unit represented by the following formula (I):

in which each X ¹ , X ² and X ³ independently represents a group represented by the following formula (Ia), a hydroxyl group,

a hydrocarbon group or a substituted hydrocarbon group, and at least one of X ¹ , X ² and X ³ is a group represented by formula (Ia) or a hydroxyl group:

wherein each R ¹ and R ² independently represents a hydrocarbon group of C _1-6, hydrocarbon group, substituted C _1-6, a silyl group or a substituted silyl group, and R ¹ and R ² may be bonded to each other to form a cyclic structure together with nitrogen atom

moreover, at least one of the end groups of the conjugated diene polymer is modified by a compound represented by the following formula (II):

in which n is an integer from 1 to 10; each R ³ , R ⁴ and R ⁵ independently represents a C _1-4 hydrocarbon group or a C _1-4 hydrocarbyl group and at least one of R ³ , R ⁴ and R ⁵ is a hydrocarbyl group; and A represents a functional group containing a nitrogen atom.

Examples of the conjugated diene used to produce the structural units of the conjugated diene include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene and 1,3-hexadiene. Each of them can be used as such, or a combination of two or more of these substances can be used. From the viewpoint of ease of preparation, 1,3-butadiene and isoprene are preferred.

Each X ¹ , X ² and X ³ in the formula (I) for the structural unit represented by the formula (I) independently represents a group represented by the formula (Ia), a hydroxyl group, a hydrocarbon group or a substituted hydrocarbon group, and at least one of X ¹ , X ² and X ³ is a group represented by formula (Ia) or a hydroxyl group.

Each R ¹ and R ² in the formula (Ia) independently represents a C _1-6 hydrocarbon group, a C _1-6 substituted hydrocarbon group, a silyl group or a substituted silyl group, and R ¹ and R ² can be linked to each other to form a cyclic structures together with a nitrogen atom.

As used in this work, the term "hydrocarbon group" means a hydrocarbon residue. Such a hydrocarbon residue refers to a monovalent group obtained by removing hydrogen from a hydrocarbon. The term “substituted hydrocarbon group” means a group obtained by substituting one or more hydrogen atoms in a hydrocarbon residue. The term “hydrocarbyloxy group” means a group obtained by replacing a hydrogen atom of a hydroxyl group with a hydrocarbon group, while the term “substituted hydrocarbyloxy group” means a group obtained by replacing one or more hydrogen atoms in a hydrocarbyloxy group with substituents. The term “substituted silyl group” means a group obtained by substituting one or more hydrogen atoms in the silyl group.

Examples of the C _1-6 hydrocarbon group for R ¹ and R ² include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, neopentyl, isopentyl and n-hexyl; cycloalkyl groups such as cyclohexyl; and phenyl group.

Examples of substituted C _1-6 hydrocarbon groups for R ¹ and R ² include substituted hydrocarbon groups, each of which contains at least one substituent selected from the group consisting of groups containing a nitrogen atom, groups containing an oxygen atom and groups containing an atom silicon. Groups comprising a group containing a nitrogen atom as a substituent may be represented by examples of dialkylaminoalkyl groups such as dimethylaminoethyl and diethylaminoethyl; groups including a group containing oxygen as a substituent may be represented by examples of alkoxyalkyl groups such as methoxymethyl, methoxyethyl, ethoxymethyl and ethoxyethyl; and groups including a silicon-containing group as a substituent may be exemplified by trialkylsilyl-alkyl groups, such as a trimethylsilylmethyl group.

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

Examples of groups in which R ¹ and R ² are linked to each other include C _1-12 divalent groups, possibly each containing at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom, and a silicon atom. Specific examples of such groups include alkylene groups such as trimethylene, tetramethylene, pentamethylene and hexamethylene; oxydialkylene groups such as oxydiethylene and oxydipropylene; and nitrogen-containing groups, such as groups represented by —CH ₂ CH ₂ —NH — CH ₂ - and groups represented by —CH ₂ CH ₂ —N = CH—.

The group in which R ¹ and R ² are bonded to each other is preferably a nitrogen-containing group and more preferably a group represented by —CH ₂ CH ₂ —NH — CH ₂ - or a group represented by —CH ₂ CH ₂ —N = CH—.

The hydrocarbon group for R ¹ and R ^{2 is} preferably an alkyl group, more preferably a C _1-4 alkyl group, more preferably a methyl group, an ethyl group, an n-propyl group or an n-butyl group, and in particular preferably an ethyl group or an n-butyl group . The substituted hydrocarbon group for R ¹ and R ^{2 is} preferably an alkoxyalkyl group and more preferably a C _1-4 alkoxyalkyl group. The substituted silyl group for R ¹ and R ^{2 is} preferably a trialkylsilyl group, and more preferably a trimethylsilyl group.

Preferably each R ¹ and R ² is an alkyl group, an alkoxyalkyl group or a substituted silyl group or is a nitrogen-containing group in which R ¹ and R ² are bonded to each other, and each of them is preferably an alkyl group, more preferably C _1-4 alkyl a group and even more preferably a methyl group, an ethyl group, an n-propyl group or an n-butyl group.

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

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

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

From the point of view of economic efficiency and wide availability, the group represented by formula (Ia) is preferably an acyclic amino group, more preferably a dialkylamino group, even more preferably a dialkylamino group containing a C _1-4 alkyl substituent, and even more preferably a dimethylamino group, diethylamino group, di (n- propyl) amino group or di (n-butyl) amino group.

Examples of the hydrocarbon group for X ¹ , X ² and X ³ in 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. Examples of the substituted hydrocarbon include alkoxyalkyl groups such as a methoxymethyl group, an ethoxymethyl group, a methoxyethyl group and an ethoxyethyl group.

The hydrocarbon group for X ¹ , X ² and X ^{3 is} preferably an alkyl group, more preferably a C _1-4 alkyl group, and even more preferably a methyl group or ethyl group. The substituted hydrocarbon group for X ¹ , X ² and X ^{3 is} preferably an alkoxyalkyl group and more preferably a C _1-4 alkoxyalkyl group.

The hydrocarbon group or substituted hydrocarbon group for X ¹ , X ² and X ^{3 is} preferably an alkyl group or an alkoxyalkyl group, more preferably a C _1-4 alkyl group or a C _1-4 alkoxyalkyl group, even more preferably a C _1-4 alkyl group and more preferably methyl group or ethyl group.

At least one of X ¹ , X ² and X ³ in the formula (I) is a hydroxyl group or a group represented by the formula (Ia). Preferably, at least two of X ¹ , X ² and X ³ are a hydroxyl group or a group represented by formula (Ia). More preferably, two of X ¹ , X ² and X ³ are a hydroxyl group or a group represented by formula (Ia). In order to achieve a good balance of high fuel economy, wet grip, and abrasion resistance, it is preferred that at least one of the groups X ¹ , X ² and X ³ be a hydroxyl group, more preferably at least two groups of X ¹ , X ² and X ³ were hydroxyl groups, and even more preferably, two groups of X ¹ , X ² , and X ³ were hydroxyl groups.

In terms of improving the balance of fuel economy, wet grip and abrasion resistance, the structural unit having the formula (I) is preferably a structural unit in which two groups of X ¹ , X ² and X ³ are an acyclic amino group or a hydroxyl group. The structural unit in which two groups of X ¹ , X ² and X ³ are acyclic amino groups is preferably a bis (dialkylamino) alkyl vinyl silane fragment, and more preferably a bis (dimethylamino) methyl vinyl silane fragment, a bis (diethylamino) methyl vinyl silane fragment, bis (di (n-propyl) amino) methyl vinylsilane fragment or bis (di (n-butyl) amino) methyl vinylsilane fragment. The structural unit in which two groups of X ¹ , X ² and X ³ are hydroxyl groups is preferably a dihydroxyalkyl vinyl silane fragment and more preferably a dihydroxymethyl vinyl silane fragment.

In terms of improving the balance of fuel economy, wet grip, and abrasion resistance, the number of structural units having formula (I) in a conjugated diene polymer (per unit mass of polymer) is preferably at least 0.001 mmol / g of polymer but not more than 0.1 mmol / g of polymer. More preferably, said amount is at least 0.002 mmol / g of polymer, but not more than 0.07 mmol / g of polymer. Even more preferably, said amount is at least 0.003 mmol / g of polymer, but not more than 0.05 mmol / g of polymer.

The conjugated diene polymer is a polymer containing at least one end group modified with a compound represented by the following formula (II):

in which n is an integer from 1 to 10; each R ³ , R ⁴ and R ⁵ independently represents a C _1-4 hydrocarbon group or a Ci-4 hydrocarbyloxy group, and at least one of R ³ , R ⁴ and R ⁵ represents a hydrocarbyloxy group; and A represents a functional group containing a nitrogen atom.

Each R ³ , R ⁴ and R ⁵ in the formula (II) independently represents a C _1-4 hydrocarbon group or a C _1-4 hydrocarbyloxy group and at least one of R ³ , R ⁴ and R ⁵ is a hydrocarbyloxy group.

Examples of the hydrocarbon group for R ³ , R ⁴ and R ⁵ include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl and tert-butyl. Examples of hydrocarbyloxyl groups for R ³ , R ⁴ and R ⁵ include an alkoxyl group such as a methoxyl group, an ethoxyl group, an n-propoxyl group, an isopropoxyl group, an n-butoxyl group, a sec-butoxyl group and a t-butoxyl group.

The hydrocarbon group for R ³ , R ⁴ and R ^{5 is} preferably an alkyl group, more preferably a C _1-3 alkyl group, and even more preferably a methyl or ethyl group. The hydrocarbyloxy group for R ³ , R ⁴ and R ^{5 is} preferably an alkoxy group, more preferably a C _1-3 alkoxy group, and even more preferably a methoxy or ethoxy group.

Considering R ³ , R ⁴ and R ⁵ , it is preferable that at least two groups of R ³ , R ⁴ and R ⁵ be hydrocarbyloxy groups, and more preferably, three groups of R ³ , R ⁴ and R ⁵ are hydrocarbyloxy groups, to achieve fuel economy, wet grip and abrasion resistance with good balance.

n in formula (II) represents an integer from 1 to 10. From the point of view of achieving balanced fuel economy, wet grip and abrasion resistance, n is preferably not more than 3. In terms of improving economic efficiency, n is preferably not more than 4. In particular, n is preferably 3.

And in the formula (II) is a functional group containing a nitrogen atom, and examples of the latter include an amino group, an isocino group, a cyano group, a pyridyl group, a piperidyl group, a pyrazinyl group, a morpholino group and the like.

A is preferably a group represented by the following formula (IIa):

in which each R ⁶ and R ⁷ independently represents a group C _1-6 , possibly containing at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom and a silicon atom; R ⁶ and R ⁷ may be bonded to each other to form a cyclic structure together with a nitrogen atom; and R ⁶ and R ⁷ can form a single group bonded to nitrogen via a double bond.

Examples of R ⁶ and R ⁷ in formula (IIa) include C _1-6 hydrocarbon groups, C _1-6 substituted hydrocarbon groups, and substituted silyl groups.

Examples of hydrocarbon groups for R ⁶ and R ⁷ include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, n-pentyl group, nonopentyl a group, an isopentyl group and an n-hexyl group; cycloalkyl groups such as a cyclohexyl group; and phenyl group.

Examples of substituted hydrocarbon groups for R ⁶ and R ⁷ include substituted hydrocarbon groups, each of which contains at least one substituent selected from the group consisting of groups containing a nitrogen atom, groups containing an oxygen atom, and groups containing an atom silicon. Groups comprising a group containing a nitrogen atom as a substituent can be represented by the following examples of dialkylaminoalkyl groups, such as a dimethylaminoethyl and diethylaminoethyl group. Groups comprising an oxygen-containing group as a substituent may be represented by the following examples of alkoxyalkyl groups, such as a methoxymethyl, methoxyethyl, ethoxymethyl and ethoxyethyl group; alkylene oxide groups such as an epoxy group and a tetrahydrofuranyl group; and alkylene oxide alkyl groups such as glycidyl group and tetrahydrofurfuryl group. Groups including a silicon-containing group as a substituent may be exemplified by trialkylsilylalkyl groups, such as a trimethylsilylmethyl group.

As used in this work, the term "alkylene oxide group" means a monovalent group obtained by removing a hydrogen atom from the ring of a cyclic ester compound. The term “alkylene oxide alkyl group” means a group obtained by substituting at least one hydrogen atom in the alkyl group with an alkylene oxide group.

Examples of substituted silyl groups for R ⁶ and R ⁷ include trialkylsilyl groups such as a trimethylsilyl group, a triethylsilyl group and a t-butyldimethylsilyl group; and trialkoxysilyl groups, such as a trimethoxysilyl group.

Examples of the group in which R ⁶ and R ⁷ are bonded to each other include C _2-12 divalent groups, possibly each containing at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom and a silicon atom . Specific examples of such groups include alkylene groups such as a trimethylene group, a tetramethylene group, a pentamethylene group, and a hexamethylene group; oxydialkylene groups such as oxydiethylene group and oxydipropylene group; and nitrogen-containing groups, such as the group represented by —CH ₂ CH ₂ —NH — CH ₂ - and the group represented by —CH ₂ CH ₂ —N = CH—.

The group in which R ⁶ and R ⁷ are bonded to each other is preferably a nitrogen-containing group and more preferably a group represented by —CH ₂ CH ₂ —NH — CH ₂ - and a group represented by —CH ₂ CH ₂ —N = CH—.

Examples of a single nitrogen-bonded group via a double bond for R ⁶ and R ⁷ include C _2-12 divalent groups, possibly each containing at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom, and an atom silicon. Specific examples of such groups include an ethylidene group, a 1-methylpropylidene group, a 1,3-dimethylbutylidene group, a 1-methylethylidene group, and a 4-N, N-dimethylaminobenzylidene group.

The hydrocarbon group for R ⁶ and R ^{7 is} preferably an alkyl group, more preferably a C _1-4 alkyl group, even more preferably a methyl, ethyl, n-propyl or n-butyl, and even more preferably methyl or ethyl group. The substituted hydrocarbon group for R ⁶ and R ^{7 is} preferably an alkoxyalkyl group, an alkylene oxide group or an alkylene oxide alkyl group. The substituted silyl group for R ⁶ and R ^{7 is} preferably a trialkylsilyl group or a trialkoxysilyl group, more preferably a trialkylsilyl group and even more preferably a trimethylsilyl or triethylsilyl group.

Preferably, R ⁶ and R ⁷ are a nitrogen-containing group in which R ⁶ and R ⁷ are bonded to each other or each is an alkyl group, an alkoxyalkyl group, an alkylene oxide group, an alkylene oxide alkyl group or a substituted silyl group, and more preferably an alkyl group, an alkylene oxide group, alkylene oxide alkyl group or trialkylsilyl group.

Examples of the groups represented by formula (IIa) include cyclic amino groups and cyclic amino groups.

Examples of acyclic amino groups include dialkylamino groups such as dimethylamino group, diethylamino group, di (n-propyl) amino group, di (isopropyl) amino group, di (n-butyl) amino group, di (sec-butyl) amino group, di (tert-butyl) amino group, di (neopentyl) amino group and ethylmethylamino group; di (alkoxyalkyl) amino groups such as di (methoxymethyl) amino group, di (methoxyethyl) amino group, di (ethoxymethyl) amino group and di (ethoxyethyl) amino group; and di (trialkylsilyl) amino groups such as a di (trimethylsilyl) amino group and a di (t-butyldimethylsilyl) amino group. Other examples of groups include a (di (alkylene oxide) amino group such as a di (epoxy) amino group and a di (tetrahydrofuranyl) amino group; and a di (alkylene oxide alkyl) amino group such as a di (glycidyl) amino group and di (tetrahydrofurfuryl) amino group. Additional examples of groups include ethylideneamino group, 1-methylpropylideneamino group, 1,3-dimethylbutylideneamino group, 1-methylethylideneamino group and 4-N, N-dimethylaminobenzylideneamino group.

As used in this work, the term "di (alkylene oxide) amino group" means a group obtained by replacing two hydrogen atoms bonded to the nitrogen atom of the amino group with two alkylene oxide groups. The term “di (alkylene oxide alkyl) amino group” means a group obtained by substituting two hydrogen atoms bonded to the nitrogen atom of the amino group with two alkylene oxide alkyl groups.

Examples of cyclic amino groups include 1-polymethyleneimino groups such as 1-pyrrolidinyl groups, 1-piperidino group, 1-hexamethyleneimino group, 1-heptamethyleneimino group, 1-octamethyleneimino group, 1-decamethyleneimino group, and 1-dodecamethyleneimino group. Other examples of cyclic amino groups include a 1-imidazolyl group, a 4,5-dihydro-1-imisolyl group, a 1-imidazolidinyl group, a 1-piperazinyl group, and a morpholino group.

With respect to achieving fuel economy, wet grip performance, abrasion resistance, and long-term stability and wide availability of the compound, the group represented by formula (IIa) is preferably an acyclic amino group and more preferably a dialkylamino group, di (alkylene oxide) amino group, di (alkylene oxide) an alkyl) amino group or a di (trialkylsilyl) amino group.

Examples of the compound represented by formula (II) include compounds in which a group of formula (IIa) is an acyclic amino group, such as a dialkylamino group, a di (alkoxyalkyl) amino group, a di (alkylene oxide) amino group, a di (alkylene oxide alkyl) amino group, or a di (trialkylsilyl) amino group .

Compounds in which a group of formula (IIa) is a dialkylamino group can be represented by the following examples:

[3- (dialkylamino) propyl] trialkoxysilanes such as

[3- (dimethylamino) propyl] trimethoxysilane,

[3- (diethylamino) propyl] trimethoxysilane,

[3- (ethylmethylamino) propyl] trimethoxysilane,

[3- (dimethylamino) propyl] triethoxysilane,

[3- (diethylamino) propyl] triethoxysilane, and

[3- (ethylmethylamino) propyl] triethoxysilane;

[3- (dialkylamino) propyl] alkyldialkoxysilanes, such as

[3- (dimethylamino) propyl] methyldimethoxysilane,

[3- (diethylamino) propyl] methyldimethoxysilane,

[3- (ethylmethylamino) propyl] methyldimethoxysilane,

[3- (dimethylamino) propyl] ethyldimethoxysilane,

[3- (diethylamino) propyl] ethyldimethoxysilane,

[3- (ethylmethylamino) propyl] ethyldimethoxysilane,

[3- (dimethylamino) propyl] methyldiethoxysilane,

[3- (diethylamino) propyl] methyldiethoxysilane,

[3- (ethylmethylamino) propyl] methyldiethoxysilane,

[3- (dimethylamino) propyl] ethyldiethoxysilane,

[3- (diethylamino) propyl] ethyldiethoxysilane and

[3- (ethylmethylamino) propyl] ethyldiethoxysilane; and

[3- (dialkylamino) propyl] dialkylalkoxysilanes, such as

[3- (dimethylamino) propyl] dimethylmethoxysilane,

[3- (diethylamino) propyl] dimethylmethoxysilane,

[3- (dimethylamino) propyl] diethylmethoxysilane,

[3- (diethylamino) propyl] diethylmethoxysilane,

[3- (dimethylamino) propyl] dimethylethoxysilane,

[3- (diethylamino) propyl] dimethylethoxysilane,

[3- (dimethylamino) propyl] diethylethoxysilane and

[3- (diethylamino) propyl] diethylethoxysilane.

Compounds in which the group of formula (IIa) is a di (alkoxyalkyl) amino group can be illustrated by the following examples:

{3- [Di (alkoxyalkyl) amino] propyl} trialkoxysilanes, such as

{3- [Di (methoxymethyl) amino] propyl} trimethoxysilane,

{3- [Di (ethoxymethyl) amino] propyl} trimethoxysilane,

{3- [Di (methoxyethyl) amino] propyl} trimethoxysilane,

{3- [Di (ethoxyethyl) amino] propyl} trimethoxysilane,

{3- [Di (methoxymethyl) amino] propyl} triethoxysilane,

{3- [Di (ethoxymethyl) amino] propyl} triethoxysilane,

{3- [Di (methoxyethyl) amino] propyl} triethoxysilane and

{3- [di (ethoxyethyl) amino] propyl} triethoxysilane;

{3- [Di (alkoxyalkyl) amino] propyl} alkyldialkoxysilanes, such as

{3- [Di (methoxymethyl) amino] propyl} methyldimethoxysilane,

{3- [Di (ethoxymethyl) amino] propyl} methyldimethoxysilane,

{3- [Di (methoxyethyl) amino] propyl} methyldimethoxysilane,

{3- [Di (ethoxyethyl) amino] propyl} methyldimethoxysilane,

{3- [Di (methoxymethyl) amino] propyl} ethyldimethoxysilane,

{3- [Di (ethoxymethyl) amino] propyl} ethyldimethoxysilane,

{3- [Di (methoxyethyl) amino] propyl} ethyldimethoxysilane,

{3- [Di (ethoxyethyl) amino] propyl} ethyldimethoxysilane,

{3- [Di (methoxymethyl) amino] propyl} methyldiethoxysilane,

{3- [Di (ethoxymethyl) amino] propyl} methyldiethoxysilane,

{3- [Di (methoxyethyl) amino] propyl} methyldiethoxysilane,

{3- [Di (ethoxyethyl) amino] propyl} methyldiethoxysilane,

{3- [Di (methoxymethyl) amino] propyl} ethyldiethoxysilane,

{3- [Di (ethoxymethyl) amino] propyl} ethyldiethoxysilane,

{3- [Di (methoxyethyl) amino] propyl} ethyldiethoxysilane, and

{3- [di (ethoxyethyl) amino] propyl} ethyldiethoxysilane; and

{3- [Di (alkoxyalkyl) amino] propyl} dialkylalkoxysilanes, such as

{3- [Di (methoxymethyl) amino] propyl} dimethylmethoxysilane,

{3- [Di (ethoxymethyl) amino] propyl} dimethylmethoxysilane,

{3- [Di (methoxyethyl) amino] propyl} dimethylmethoxysilane,

{3- [Di (ethoxyethyl) amino] propyl} dimethylmethoxysilane,

{3- [di (methoxymethyl) amino] propyl} diethylmethoxysilane,

{3- [di (ethoxymethyl) amino] propyl} diethylmethoxysilane,

{3- [di (methoxyethyl) amino] propyl} diethylmethoxysilane,

{3- [di (ethoxyethyl) amino] propyl} diethylmethoxysilane,

{3- [Di (methoxymethyl) amino] propyl} dimethylethoxysilane,

{3- [Di (ethoxymethyl) amino] propyl} dimethylethoxysilane,

{3- [Di (methoxyethyl) amino] propyl} dimethylethoxysilane,

{3- [Di (ethoxyethyl) amino] propyl} dimethylethoxysilane,

{3- [Di (methoxymethyl) amino] propyl} diethylethoxysilane,

{3- [Di (ethoxymethyl) amino] propyl} diethylethoxysilane,

{3- [Di (methoxyethyl) amino] propyl} diethylethoxysilane, and

{3- [Di (ethoxyethyl) amino] propyl} diethylethoxysilane.

Compounds in which a group with formula (IIa) is a di (alkylene oxide) amino group can be illustrated by the following compounds in which a group with formula (IIa) is a di (epoxy) amino group, for example

{3- [Di (epoxy) amino] propyl} trimethoxysilane,

{3- [Di (epoxy) amino] propyl} triethoxysilane,

{3- [Di (epoxy) amino] propyl} methyldimethoxysilane,

{3- [Di (epoxy) amino] propyl} ethyldimethoxysilane,

{3- [Di (epoxy) amino] propyl} methyldiethoxysilane,

{3- [Di (epoxy) amino] propyl} ethyldiethoxysilane,

{3- [Di (epoxy) amino] propyl} dimethylmethoxysilane,

{3- [Di (epoxy) amino] propyl} diethylmethoxysilane,

{3- [Di (epoxy) amino] propyl} dimethylethoxysilane and

{3- [di (epoxy) amino] propyl} diethylethoxysilane; and

compounds in which a group with the formula (IIa) is a di (tetrahydrofuranyl) amino group, for example

{3- [Di (tetrahydrofuranyl) amino] propyl} trimethoxysilane,

{3- [Di (tetrahydrofuranyl) amino] propyl} triethoxysilane,

{3- [Di (tetrahydrofuranyl) amino] propyl} methyldimethoxy silane,

{3- [Di (tetrahydrofuranyl) amino] propyl} ethyldimethoxy silane,

{3- [Di (tetrahydrofuranyl) amino] propyl} methyldiethoxy-silane,

{3- [Di (tetrahydrofuranyl) amino] propyl} ethyldiethoxy-silane,

{3- [Di (tetrahydrofuranyl) amino] propyl} dimethylmethoxy silane,

{3- [di (tetrahydrofuranyl) amino] propyl} diethylmethoxy silane,

{3- [Di (tetrahydrofuranyl) amino] propyl} dimethylethoxy silane, and

{3- [Di (tetrahydrofuranyl) amino] propyl} diethylethoxy silane,

Compounds in which a group with formula (IIa) is a di (alkylene oxide alkyl) amino group can be represented by the following compounds in which a group with formula (IIa) is a di (glycidyl) amino group, for example

{3- [Di (glycidyl) amino] propyl} trimethoxysilane,

{3- [Di (glycidyl) amino] propyl} triethoxysilane,

{3- [Di (glycidyl) amino] propyl} methyldimethoxysilane,

{3- [Di (glycidyl) amino] propyl} ethyldimethoxysilane,

{3- [Di (glycidyl) amino] propyl} methyldiethoxysilane,

{3- [Di (glycidyl) amino] propyl} ethyldiethoxysilane,

{3- [Di (glycidyl) amino] propyl} dimethylmethoxysilane,

{3- [di (glycidyl) amino] propyl} diethylmethoxysilane,

{3- [Di (glycidyl) amino] propyl} dimethylethoxysilane and

{3- [di (glycidyl) amino] propyl} diethylethoxysilane; and

compounds in which a group with the formula (IIa) is a di (tetrahydrofurfuryl) amino group, for example

{3- [Di (tetrahydrofurfuryl) amino] propyl} trimethoxysilane,

{3- [di (tetrahydrofurfuryl) amino] propyl} triethoxysilane,

{3- [Di (tetrahydrofurfuryl) amino] propyl} methyldimethoxysilane,

{3- [Di (tetrahydrofurfuryl) amino] propyl} ethyldimethoxysilane,

{3- [Di (tetrahydrofurfuryl) amino] propyl} methyldiethoxysilane,

{3- [Di (tetrahydrofurfuryl) amino] propyl} ethyldiethoxysilane,

{3- [Di (tetrahydrofurfuryl) amino] propyl} dimethylmethoxysilane,

{3- [di (tetrahydrofurfuryl) amino] propyl} diethylmethoxysilane,

{3- [Di (tetrahydrofurfuryl) amino] propyl} dimethylethoxysilane, and

{3- [Di (tetrahydrofurfuryl) amino] propyl} diethylethoxysilane.

Compounds in which the group of formula (IIa) is a di (trialkylsilyl) amino group can be represented by the following examples:

{3- [di (trialkylsilyl) amino] propyl} trialkoxysilanes, such as

{3- [di (trimethylsilyl) amino] propyl} trimethoxysilane,

{3- [di (t-butyldimethylsilyl) amino] propyl} trimethoxysilane,

{3- [di (trimethylsilyl) amino] propyl} triethoxysilane and

{3- [di (t-butyldimethylsilyl) amino] propyl} triethoxysilane;

{3- [di (trialkylsilyl) amino] propyl} alkyldialkoxysilanes, such as

{3- [di (trimethylsilyl) amino] propyl} methyldimethoxysilane,

{3- [di (t-butyldimethylsilyl) amino] propyl} methyldimethoxysilane,

{3- [Di (trimethylsilyl) amino] propyl} methyldiethoxysilane and

{3- [di (t-butyldimethylsilyl) amino] propyl} methyldiethoxysilane; and

{3- [di (trialkylsilyl) amino] propyl} dialkylalkoxysilanes, such as

{3- [di (trimethylsilyl) amino] propyl} dimethylmethoxysilane,

{3- [di (t-butyldimethylsilyl) amino] propyl} dimethylmethoxysilane,

{3- [Di (trimethylsilyl) amino] propyl} dimethylethoxysilane and

{3- [Di (t-butyldimethylsilyl) amino] propyl} dimethylethoxysilane.

Among the examples above,

[3 (dialkylamino) propyl] trialkoxysilanes are preferred and

[3- (dimethylamino) propyl] trimethoxysilane,

[3- (diethylamino) propyl] trimethoxysilane,

[3- (dimethylamino) propyl] triethoxysilane and

[3- (diethylamino) propyl] triethoxysilane are more preferred.

Other examples of the compound represented by formula (II) include compounds in which the group of formula (IIa) is a cyclic amino group, such as a 1-piperidino group, 1-hexamethyleneimino group, 1-imidazolyl group, 4,5-dihydro-1-imidazolyl group , 1-piperazinyl group or morpholino group.

Compounds in which a group according to formula (IIa) is a 1-piperidino group can be represented by the following examples:

3- (1-piperidino) propyltrimethoxysilane,

3- (1-piperidino) propyltriethoxysilane,

3- (1-piperidino) propylmethyldimethoxysilane,

3- (1-piperidino) propylethyldimethoxysilane,

3- (1-piperidino) propylmethyldiethoxysilane and

3- (1-piperidino) propylethyldiethoxysilane.

Compounds in which a group according to formula (IIa) is a 1-hexamethyleneimino group can be represented by the following examples:

3- (1-hexamethyleneimino) propyltrimethoxysilane,

3- (1-hexamethyleneimino) propyltriethoxysilane,

3- (1-hexamethyleneimino) propylmethyldimethoxysilane,

3- (1-hexamethyleneimino) propylethyldimethoxysilane,

3- (1-hexamethyleneimino) propylmethyldiethoxysilane and

3- (1-hexamethyleneimino) propylethyldiethoxysilane.

Compounds in which a group of formula (IIa) is a 1-imidazolyl group can be represented by the following examples:

N- (3-trimethoxysilylpropyl) imidazole and

N- (3-triethoxysilylpropyl) imidazole.

Compounds in which the group of formula (IIa) is a 4,5-dihydro-1-imidazolyl group can be represented by the following examples:

N- (3-trimethoxysilylpropyl) -4,5-dihydroimidazole and

N- (3-triethoxysilylpropyl) -4,5-dihydroimidazole.

Compounds in which a group of formula (IIa) is a 1-piperazinyl group can be represented by the following examples:

3- (1-piperazinyl) propyltrimethoxysilane,

3- (1-piperazinyl) propyltriethoxysilane,

3- (1-piperazinyl) propylmethyldimethoxysilane,

3- (1-piperazinyl) propylethyldimethoxysilane,

3- (1-piperazinyl) propylmethyldiethoxysilane and

3- (1-piperazinyl) propylethyldiethoxysilane.

Compounds in which the group of formula (IIa) is a morpholino group can be represented by the following examples:

3-morpholinopropyltrimethoxysilane,

3-morpholinopropyltriethoxysilane,

3-morpholinopropylmethyldimethoxysilane,

3-morpholinopropylethyldimethoxysilane,

3-morpholinopropylmethyldiethoxysilane and

3-morpholinopropylethyldiethoxysilane.

Among the above examples, compounds in which a group with formula (IIa) is a 1-imidazolyl group and compounds in which a group with formula (IIa) is a 4,5-dihydro-1-imidazolyl group are preferred and

N- (3-trimethoxysilylpropyl) imidazole and

N- (3-triethoxysilylpropyl) imidazole.

N- (3-trimethoxysilylpropyl) -4,5-dihydroimidazole and

N- (3-triethoxysilylpropyl) -4,5-dihydroimidazole is most preferred.

In addition to structural units derived from a conjugated diene (conjugated diene units), a conjugated diene polymer may also contain structural units derived from another monomer. Examples of other monomers include aromatic vinyls, vinyl nitriles and esters of unsaturated carboxylic acids. Aromatic vinyls can be represented by the following examples: styrene, α-methylstyrene, vinyltoluene, vinylnaphthalene, divinylbenzene, trivinylbenzene and divinylnaphthalene. Vinyl nitriles can be represented by the following examples: acrylonitrile and the like, and esters of unsaturated carboxylic acids can be represented by the following examples: methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate and the like. Among these examples, aromatic vinyls are preferred, and styrene is more preferred.

To increase abrasion resistance, the conjugated diene polymer preferably contains structural units derived from aromatic vinyl (aromatic vinyl units). In this case, based on the total number of conjugated diene units and aromatic

vinyl units (= 100% by mass), the content of aromatic vinyl units is preferably not less than 10% by mass (the content of conjugated diene units is not more than 90% by mass) and more preferably not less than 15% by mass (the content of conjugated diene units is not more than 85% of the mass). In order to increase fuel economy, the content of aromatic vinyl units is preferably not more than 50 wt% (the content of conjugated diene units is at least 50 wt%) and more preferably not more than 45 wt% (the content of conjugated diene units is at least 55% masses).

If we take the content of conjugated diene units as 100 mol%, then in order to increase fuel economy, the content of vinyl bonds in the conjugated diene polymer is preferably not more than 80 mol%. and more preferably not more than 70 mol%. To improve wet grip, the vinyl content is preferably at least 10 mol%, more preferably at least 15 mol%, even more preferably at least 20 mol%. and particularly preferably at least 40 mol%. The content of vinyl bonds can be determined using infrared spectroscopy and calculated from the intensity of the absorption band located at 910 cm ^-1 , which is the peak absorption of the vinyl group.

In order to increase fuel economy, the molecular weight distribution of the conjugated diene polymer is preferably 1 to 5, and more preferably 1 to 2. The molecular weight distribution can be determined after measuring the number average molecular weight (Mn) and weight average molecular weight (Mw) by gel permeation chromatography (GPC) and the subsequent division of Mw into Mn.

Suitable examples of a method for producing a conjugated diene polymer include a preparation method comprising Steps A and B, discussed below.

(Step A): A polymerization step of monomers comprising a conjugated diene and a vinyl compound having the formula (III) below in the presence of an alkali metal catalyst in a hydrocarbon solvent to form a polymer whose polymer chain

contains a monomer unit derived from a conjugated diene and a monomer unit derived from a vinyl compound having the formula (III), and which contains at least one terminal group containing an alkali metal obtained from a catalyst:

in which each X ⁴ , X ⁵ and X ⁶ independently represents a group represented by formula (IIIa) below, a hydrocarbon group or a substituted hydrocarbon group and at least one of X ⁴ , X ⁵ and X ⁶ is a group represented by formula (IIIa) :

in which each R ⁸ and R ⁹ independently represents a C _1-6 hydrocarbon group, a C _1-6 substituted hydrocarbon group, a silyl group or a substituted silyl group, and R ⁸ and R ⁹ can be linked together to give a cyclic structure together with nitrogen atom.

(Step B): a step for reacting the polymer obtained in Step A with a compound represented by the following formula (II):

in which n is an integer from 1 to 10; each R ³ , R ⁴ and R ⁵ independently represents a C _1-4 hydrocarbon group or a C _1-4 hydrocarbyloxy group and at least one of R ³ , R ⁴ and R ⁵ is a hydrocarbyloxy group; and A represents a functional group containing a nitrogen atom.

Examples of the alkali metal catalysts used (in Step A) include alkali metals, organometallic compounds of alkali metals, complexes of alkali metal and polar compounds, and oligomers containing alkali metals. Non-limiting examples of alkali metals include: lithium, sodium, potassium, rubidium, cesium and the like. Non-limiting examples of organometallic alkali metal compounds include: ethyl lithium, n-propyl lithium, isopropyl lithium, n-butyl lithium, sec-butyl lithium, t-octyl lithium, n-decyl lithium, phenyl lithium, 2-naphthyl lithium, 2-butyl phenyl lithium, 4-phenyl butyl lithium, cyclohexyl lithium, 4- cyclopentyl lithium, dimethylaminopropyl lithium, diethylaminopropyl lithium, tert-butyldimethylsilyloxypropyl lithium, N-morpholinopropyl lithium, lithium hexamethylene imide, lithium pyrrolidide, lithium piperidide, lithium heptamethyleneimide, 1,4-lithium dodecamethylene butenide, 2-lithium, sodium, sodium biphenylide, potassium naphthalenide and the like. Non-limiting examples of complexes of an alkali metal and a polar compound include a tetrahydrofuran-potassium complex, a diethoxyethane-potassium complex, and the like. Non-limiting examples of alkali metal oligomers include sodium tetramer α-methyl styrene. Of these, organometallic lithium and sodium compounds are preferred, and organometallic lithium and sodium compounds having 2 to 20 carbon atoms are more preferred.

The hydrocarbon solvent used in (step A) is a solvent that does not deactivate the catalyst based on an organometal compound of an alkali metal, and examples of the latter include aliphatic hydrocarbons, aromatic hydrocarbons and alicyclic hydrocarbons. Aliphatic hydrocarbons can be represented by the following examples: propane, n-butane, iso-butane, n-pentane, iso-pentane, n-hexane, propene, 1-butene, iso-butene, trans-2-butene, cis-2- butene, 1-pentene, 2-pentene, 1-hexene, 2-hexene and the like. Aromatic hydrocarbons can be represented by the following examples: benzene, toluene, xylene and ethylbenzene. Alicyclic hydrocarbons can be represented by the following examples: cyclopentane, cillohexane and the like. One of them can be used separately or two or more of them can be used in combination. C _2-12 hydrocarbons are preferred among the examples.

Monomers including a conjugated diene and a vinyl compound having the formula (V) (during Step A) are polymerized to form a conjugated diene polymer containing an alkali metal obtained from the alkali metal catalyst described above in the terminal group of the polymer chain. Examples of conjugated dienes include 1,3-butadiene, isoprene, 1,3-pentadiene, 2,3-dimethyl-1,3-butadiene and 1,3-hexadiene. Each of them can be used as such or in combination of two or more substances. From the viewpoint of ease of preparation, preferred compounds are 1,3-butadiene and isoprene.

Each X ⁴ , X ⁵ and X ⁶ in the formula (III) independently represents a group represented by the formula (IIIa), a hydrocarbon group or a substituted hydrocarbon group and at least one of X ⁴ , X ⁵ and X ⁶ is a group represented by the formula ( IIIa).

Each R ⁸ and R ⁹ in formula (IIIa) independently represents a C _1-6 hydrocarbon group, a C _1-6 substituted hydrocarbon group, a silyl group or a substituted silyl group, and R ⁸ and R ⁹ can be linked together to give a cyclic structure together with a nitrogen atom.

Examples of the C _1-6 hydrocarbon group for R ⁸ and R ⁹ include alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, neophenyl, isophenyl and n hexyl; cycloalkyl groups such as cyclohexyl; and phenyl group.

Examples of the substituted C _1-6 hydrocarbon group in R ⁹ and R ¹⁰ include substituted hydrocarbon groups, each of which contains at least one substituent selected from the group consisting of nitrogen-containing groups, oxygen-containing groups and silicon-containing groups. Non-limiting examples of groups containing a nitrogen-containing group as a substituent include dialkylaminoalkyl groups, for example, a dimethylaminoethyl group and a diethylaminoethyl group. Non-limiting examples of groups containing an oxygen-containing group as a substituent include alkoxyalkyl groups, for example, a methoxymethyl group, a methoxyethyl group, an ethoxymethyl group, and an ethoxyethyl group. Non-limiting examples of groups containing a silicon-containing group as a substituent include trialkylsilylalkyl groups, for example, a trimethylsilylmethyl group and the like.

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

Examples of groups in which R ⁸ and R ⁹ are bonded to each other include C _1-12 divalent groups, possibly each containing at least one atom selected from the group consisting of a nitrogen atom, an oxygen atom, and an atom silicon. Specific examples of which include alkylene groups such as a trimethylene group, a tetramethylene group, a pentamethylene group, and a hexamethylene group; oxydialkylene groups such as oxydiethylene group and oxydipropylene group; and nitrogen-containing groups, such as groups represented by —CH ₂ CH ₂ —NH — CH ₂ - and groups represented by —CH ₂ CH ₂ —N = CH—.

The group in which R ⁸ and R ⁹ are bonded to each other is preferably a nitrogen-containing group and more preferably a group represented by —CH ₂ CH ₂ —NH — CH ₂ - and a group represented by —CH ₂ CH ₂ —N = CH—.

The hydrocarbon group for R ⁸ and R ^{9 is} preferably an alkyl group, more preferably a C _1-4 alkyl group, even more preferably a methyl, ethyl, n-propyl or n-butyl group, and in particular preferably an ethyl or n-butyl group. The substituted hydrocarbon group for R ⁸ and R ^{9 is} preferably an alkoxyalkyl group and more preferably a C _1-4 alkoxyalkyl group. The substituted silyl group for R ⁸ and R ^{9 is} preferably a trialkylsilyl group and more preferably a trimethylsilyl group.

Preferably each R ⁸ and R ⁹ is an alkyl group, an alkoxyalkyl group or a substituted silyl group or is a nitrogen-containing group in which R ⁸ and R ⁹ are bonded to each other and each of them is more preferably an alkyl group, even more preferably C _1-4 an alkyl group and even more preferably a methyl group, an ethyl group, an n-propyl group or an n-butyl group.

Examples of the group represented by formula (IIIa) include acyclic amino groups and cyclic amino groups.

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

Examples of cyclic amino groups include 1-polymethyleneimino groups such as 1-pyrrolidinyl group, 1-piperidino group, 1-hexamethyleneimino group, 1-heptamethyleneimino group, 1-octamethyleneimino group, 1-decamethyleneimino group and 1-dodecamethyleneimino group. Other examples of cyclic amino groups also include a 1-imidazolyl group, a 4,5-dihydro-1-imidazolyl group, a 1-imidazolidinyl group, a 1-piperazinyl group and a morpholino group.

For economic efficiency and affordability, the group having the formula (III) is preferably an acyclic amino group, more preferably a dialkylamino group, even more preferably a dialkylamino group containing a C _1-4 alkyl substituent, and most preferably a dimethylamino group, diethylamino group, di (n-propyl ) an amino group or a di (n-butyl) amino group.

Examples of the hydrocarbon group for X ⁴ , X ⁵ and X ⁶ in formula (III) include alkyl groups such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group and tert-butyl Group. Examples of the substituted hydrocarbon group include alkoxy groups such as a methoxymethyl group, an ethoxymethyl group, a methoxyethyl and ethoxyethyl group.

The hydrocarbon group for X ⁴ , X ⁵ and X ^{6 is} preferably an alkyl group, more preferably a C _1-4 alkyl group, and even more preferably a methyl group or ethyl group. The substituted hydrocarbon group for X ⁴ , X ⁵ and X ^{6 is} preferably an alkoxy group and more preferably a C _1-4 alkoxyalkyl group.

The hydrocarbon group or substituted hydrocarbon group for X ⁴ , X ⁵ and X ^{6 is} preferably an alkyl group or alkoxy group, more preferably a C _1-4 alkyl or C _1-4 alkoxyalkyl group, even more preferably a C _1-4 alkyl group and even more preferably a methyl or ethyl group.

At least one of X ⁴ , X ⁵ and X ⁶ in the formula (III) is a group represented by the formula (IIIa). Preferably, at least two of X ⁴ , X ⁵ and X ⁶ are groups represented by formula (IIIa) and more preferably two of X ⁴ , X ⁵ and X ⁶ are groups represented by formula (IIIa).

Examples of the vinyl compound represented by formula (III) used in (step A) include compounds in which one of X ⁴ , X ⁵ and X ⁶ is an acyclic amino group represented by formula (IIIa), and each of the other two is a hydrocarbon group or a substituted hydrocarbon group, for example, (dialkylamino) dialkylvinylsilanes, {di (trialkylsilyl) amino} dialkylvinylsilanes and (dialkylamino) dialkoxyalkylvinylsilanes.

(Dialkylamino) dialkylvinylsilanes can be represented by the following examples:

(dimethylamino) dimethylvinylsilane,

(ethylmethylamino) dimethylvinylsilane,

(diethylamino) dimethylvinylsilane,

(ethyl-n-propylamino) dimethylvinylsilane,

(ethyl isopropylamino) dimethyl vinyl silane,

(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) diethyl vinyl silane,

(ethyl isopropylamino) diethyl vinyl silane,

(di (n-propyl) amino) diethyl vinyl silane,

(diisopropylamino) diethylvinyl silane,

(n-butyl-n-propylamino) diethyl vinyl silane,

(di (n-butyl) amino) diethyl vinyl silane,

(dimethylamino) dipropylvinylsilane,

(ethylmethylamino) dipropylvinylsilane,

(diethylamino) dipropylvinylsilane,

(ethyl n-propylamino) dipropyl vinyl silane,

(ethyl isopropylamino) dipropyl vinyl silane,

(di (n-propyl) amino) dipropyl vinyl silane,

(diisopropylamino) dipropylvinylsilane,

(n-butyl-n-propylamino) dipropyl vinyl silane,

(di (n-butyl) amino) dipropyl vinyl silane,

(dimethylamino) dibutylvinylsilane,

(ethylmethylamino) dibutylvinylsilane,

(diethylamino) dibutylvinylsilane,

(ethyl n-propylamino) dibutyl vinyl silane,

(ethyl isopropylamino) dibutyl vinyl silane,

(di (n-propyl) amino) dibutylvinylsilane,

(diisopropylamino) dibutylvinylsilane,

(n-butyl-n-propylamino) dibutylvinylsilane,

(di (n-butyl) amino) dibutylvinylsilane and the like.

{Di (trialkylsilyl) amino} dialkylvinylsilanes can be represented by the following examples:

{di (trimethylsilyl) amino} dimethylvinylsilane,

{di (t-butyldimethylsilyl) amino} dimethylvinylsilane,

{di (trimethylsilyl) amino} diethylvinylsilane,

{di (t-butyldimethylsilyl) amino} diethyl vinyl silane and the like.

(Dialkylamino) dialkoxyalkylvinylsilanes can be represented by the following examples:

(dimethylamino) dimethoxymethylvinylsilane,

(dimethylamino) dimethoxyethyl vinyl silane,

(dimethylamino) diethoxymethylvinylsilane,

(dimethylamino) diethoxyethyl vinyl silane,

(diethylamino) dimethoxymethylvinylsilane,

(diethylamino) dimethoxyethyl vinyl silane,

(diethylamino) diethoxymethylvinylsilane,

(diethylamino) diethoxyethyl vinyl silane and the like.

Mention may be made of compounds in which two of X ⁴ , X ⁵ and X ⁶ are acyclic amino groups represented by formula (IIIa) and the third substituent is a hydrocarbon group or a substituted hydrocarbon group such as bis (dialkylamino) alkylvinylsilanes, bis {di (trialkylsilyl) -amino} alkyl vinyl silanes and bis (dialkylamino) alkoxyalkyl vinyl silanes.

Bis (dialkylamino) alkylvinylsilanes can be represented by the following examples:

bis (dimethylamino) methylvinylsilane,

bis (ethylmethylamino) methylvinylsilane,

bis (diethylmethylamino) methylvinylsilane,

bis (ethyl-n-propylamino) methylvinylsilane,

bis (ethyl isopropylamino) methyl vinyl silane,

bis (di (n-propyl) amino) methylvinylsilane,

bis (diisopropylamino) methylvinylsilane,

bis (n-butyl-n-propylamino) methylvinylsilane,

bis (di (n-butyl) amino) methylvinylsilane,

bis (dimethylmethylamino) ethylvinylsilane,

bis (ethylmethylamino) ethylvinylsilane,

bis (diethylmethylamino) ethylvinylsilane,

bis (ethyl-n-propylamino) ethylvinylsilane,

bis (ethyl isopropylamino) ethyl vinyl silane,

bis (di (n-propyl) amino) ethylvinylsilane,

bis (diisopropylamino) ethylvinylsilane,

bis (n-butyl-n-propylamino) ethylvinylsilane,

bis (di (n-butyl) amino) ethylvinylsilane,

bis (dimethylmethylamino) ethylvinylsilane,

bis (ethylmethylamino) propylvinylsilane,

bis (diethylmethylamino) propylvinylsilane,

bis (ethyl n-propylamino) propyl vinyl silane,

bis (ethyl isopropylamino) propyl vinyl silane,

bis (di (n-propyl) amino) propylvinylsilane,

bis (diisopropylamino) propylvinylsilane,

bis (n-butyl-n-propylamino) propyl vinyl silane,

bis (di (n-butyl) amino) propylvinylsilane,

bis (dimethylmethylamino) butylvinylsilane,

bis (ethylmethylamino) butylvinylsilane,

bis (diethylmethylamino) butylvinylsilane,

bis (ethyl-n-propylamino) butylvinylsilane,

bis (ethyl isopropylamino) butyl vinyl silane,

bis (di (n-propyl) amino) butyl vinylsilane,

bis (diisopropylamino) butylvinylsilane,

bis (n-butyl-n-propylamino) butylvinylsilane,

bis (di (n-butyl) amino) butylvinylsilane and the like.

Bis {di (trialkylsilyl) amino} alkylvinylsilanes can be represented by the following examples:

bis {di (trimethylsilyl) amino} methylvinylsilane,

bis {di (t-butyldimethylsilyl) amino} methylvinylsilane,

bis {di (trimethylsilyl) amino} ethylvinylsilane,

bis {di (t-butyldimethylsilyl) amino} ethylvinylsilane and the like.

Bis (dialkylamino) alkoxyalkyl vinyl silanes can be represented by the following examples:

bis (dimethylmethylamino) methoxymethylvinylsilane,

bis (dimethylmethylamino) methoxyethyl vinyl silane,

bis (dimethylmethylamino) ethoxymethylvinylsilane,

bis (dimethylmethylamino) ethoxyethyl vinyl silane,

bis (diethylmethylamino) methoxymethylvinylsilane,

bis (diethylmethylamino) methoxyethyl vinyl silane,

bis (diethylmethylamino) ethoxymethylvinylsilane,

bis (diethylmethylamino) ethoxyethyl vinyl silane and the like.

Mention may be made of compounds in which all three X ⁴ , X ⁵ and X ⁶ are acyclic amino groups represented by formula (IIIa), such as three (dialkylamino) vinyl silanes.

Examples of such compounds include:

tri (dimethylamino) vinylsilane,

tri (ethylmethylamino) vinylsilane,

three (diethylamino) vinylsilane,

tri (ethylpropylamino) vinylsilane,

three (dipropylamino) vinylsilane and

tri (butylpropylamino) vinylsilane.

Mention may be made of compounds in which two of X ⁴ , X ⁵ and X ⁶ are cyclic amino groups represented by the formula (IIIa) and the third substituent is a hydrocarbon group or a substituted hydrocarbon group such as bis (morpholino) methyl vinyl silane, bis (piperidino) methyl vinyl silane, bis (4,5-dihydroimidazolyl) methylvinylsilane; and bis (hexamethyleneimino) methylvinylsilane.

A vinyl compound represented by formula (III) in which X ⁴ , X ⁵ and X ⁶ are groups represented by formula (IIIa) is preferably a vinyl compound in which two of X ⁴ , X ⁵ and X ⁶ are acyclic amino groups, and , in order to increase fuel economy, wet grip, and abrasion resistance, more preferably bis (dialkylamino) alkyl vinyl silane and even more preferably bis (dimethylamino) methyl vinyl silane,

bis (diethylamino) methylvinylsilane,

bis (di (n-propyl) amino) methylvinylsilane or

bis (di (n-butyl) amino) methylvinylsilane. From the point of view of the availability of the compound, bis (diethylamino) methyl vinylsilane and bis (di (n-butyl) amino) methyl vinyl silane are preferred.

In (step A), the combination of a conjugated diene and a vinyl compound represented by the formula (III) with another monomer can be polymerized. Examples of other monomers include aromatic vinyls, vinyl nitriles and unsaturated carboxylic acid esters. Aromatic vinyls can be represented by the following examples: styrene, α-methylstyrene, vinyltoluene, vinylnaphthalene, divinylbenzene, trivinylbenzene and divinylnaphthalene. Vinyl nitriles can be represented by examples of acrylonitrile and the like, and unsaturated carboxylic acid esters can be represented by the following examples: methyl acrylate, ethyl acrylate, methyl methacrylate, ethyl methacrylate and the like. Among these examples, aromatic vinyls are preferred, and styrene is more preferred.

The polymerization (Step A) can be carried out in the presence of agents, for example, an agent that regulates the content of vinyl bonds in conjugated diene units, and an agent that regulates the distribution of conjugated diene units and structural units derived from a monomer other than a conjugated diene in chains of a conjugated diene polymer (hereinafter all such agents are called "regulators"). Examples of such agents include ethers, tertiary amines and phosphine derivatives. Non-limiting examples of ethers include: cyclic ethers, for example tetrahydrofuran, tetrahydropyran and 1,4-dioxane; aliphatic monoesters, for example diethyl ether and dibutyl ether; aliphatic polyethers, for example, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol diethyl ether and diethylene glycol dibutyl ether; aromatic ethers, for example, diphenyl ether and anisole; and similar compounds. Non-limiting examples of tertiary amines include: triethylamine, tripropylamine, tributylamine, N, N, N ', N'-tetramethylethylenediamine, N, N-diethylaniline, pyridine, quinoline and the like. Non-limiting examples of phosphine derivatives include: trimethylphosphine, triethylphosphine, triphenylphosphine and the like. Each of these substances can be used as such or in combination of two or more substances.

The polymerization temperature in (step A) is usually from 25 ° C to 100 ° C, preferably from 35 ° C to 90 ° C, and more preferably from 50 ° C to 80 ° C. The polymerization time is usually from 10 minutes to 5 hours.

In (step B), the amount of the compound represented by formula (II) that comes into contact with the polymer obtained in (step a) is usually from 0.1 to 3 mol, preferably from 0.5 to 2 mol, and more preferably from 0.7 to 1.5 mol per mol of alkali metal from an alkali metal catalyst.

In (step B), the polymer obtained (in step A) is contacted with a compound represented by formula (II) usually at a temperature of from 25 ° C to 100 ° C, preferably from 35 ° C to 90 ° C, and more preferably from 50 ° C to 80 ° C. The polymerization time is usually 60 seconds to 5 hours, preferably 5 minutes to 1 hour, and more preferably 15 minutes. up to 1 hour

In the method for producing a conjugated diene polymer, a coupling agent, if necessary, can be added to the hydrocarbon solution of the conjugated diene polymer from the moment of initiation of the polymerization of monomers using an alkali metal catalyst until the termination of polymerization. Examples of a binding agent include compounds represented by the following formula (IV):

in which R ¹⁰ 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 represents an integer from 0 to 2.

The term "aromatic residue" means a monovalent group obtained by removing hydrogen bound to the aromatic ring of an aromatic hydrocarbon.

Coupling agents represented by formula (IV) may be represented by the following: silicon tetrachloride, metiltrihlrosilan, dimethyldichlorosilane, trimethylchlorosilane, tin tetrachloride, metiltrihlorolovo, dimetildihlorolovo, trimetilhlorolovo, tetramethoxysilane, methyltrimethoxysilane, dimetoksidimetilsilan, methyltriethoxysilane, ethyltrimethoxysilane, dimetoksidietilsilan, dietoksidimetilsilan, tetraethoxysilane, ethyltriethoxysilane, diethoxyethylsilane and the like.

In terms of ease of processing of the conjugated diene polymer, the amount of crosslinking agent is preferably not less than 0.03 mol and more preferably not less than 0.05 mol per mol of alkali metal obtained from an alkali metal catalyst. In order to increase fuel economy, this amount is preferably not more than 0.4 mol, and more preferably not more than 0.3 mol.

The conjugated diene polymer can be removed from the hydrocarbon solution of the conjugated diene polymer by a known recovery method, for example, (1) adding a coagulant to the hydrocarbon solution of the conjugated diene polymer; or (2) passing steam into a hydrocarbon solution of a conjugated diene polymer. The recovered conjugated diene polymer can be dried using a known drying device, for example, a belt dryer or an extrusion dryer.

In the method for producing a conjugated diene polymer, the treatment in which the group represented by formula (Ia) in the polymer is replaced with a hydroxyl group is preferably carried out, for example, by hydrolysis. This treatment is carried out on a single polymer or in the form of a composition, as described below. Examples of the hydrolysis method include known methods, such as a steam stripping process. The treatment allows the conversion of X ¹ , X ² and / or X ³ in the formula (I) into hydroxyl groups and thus contributes to improving the balance between improved fuel economy, wet grip and galling resistance.

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

Examples of other rubbers include the conventional styrene-butadiene copolymer, polybutadiene rubber (BK), butadiene-isoprene copolymer, and butyl rubber. Mention may also be made of natural rubber (NR), a copolymer of ethylene and propylene, a copolymer of ethylene and octene and the like. Two or more kinds of these rubbers may be used in combination. In particular, from the viewpoint of improving the balance of fuel economy, wet grip, and abrasion resistance, it is preferable to use NK and / or BK, and more preferably a combination of NK and BK.

The content of the conjugated diene polymer per 100% of the mass. the rubber component is preferably at least 5% by mass, more preferably at least 10% by mass, even more preferably at least 30% by mass. and particularly preferably at least 50% of the mass. If the content of the conjugated diene polymer is less than 5% by mass, an increase in fuel economy is less likely. The content of the conjugated diene polymer is preferably not more than 90% by mass, more preferably not more than 80% by mass, and even more preferably not more than 70% by mass. If the content of the conjugated diene polymer exceeds 90% by mass, then abrasion resistance may decrease and production costs may increase.

There are no practical restrictions on NK. For example, natural rubbers widely used in the tire industry can be used, such as SIR20, RSS # 3, TSR20, deproteinized natural rubber (DPNC), highly purified natural rubber (HONG) and the like.

The content of the NC in the calculation of 100 wt.% The rubber component is preferably not less than 5 wt.%. more preferably not less than 10 wt.% and even more preferably not less than 15 wt.%. Abrasion resistance tends to decrease when the content of NK is less than 5 wt.%. The content of NK is preferably not more than 70 wt.% And more preferably not more than 60 wt.%. The wet grip characteristics tend to decrease when the NK content is more than 70 mass%.

There are practically no restrictions on BC and can be used that are widely used in the tire industry, such as BC with a high content of cis bonds such as BR1220 from Zeon Corporation and BR130B and BR150B from Ube Industries, Ltd., and NC containing syndiotactic polybutadiene crystals such as VCR412 and VCR617 from Ube Industries, Ltd.

The BC content per 100 wt.% Of the rubber component is preferably not less than 5 wt.%, More preferably not less than 10 wt.% And even more preferably not less than 15 wt.%. Abrasion resistance tends to decrease when the BC content is less than 5 wt.%. The content of BC is preferably not more than 60 wt.% And more preferably not more than 50 wt.%. The wet grip characteristics tend to decrease when the BC content exceeds 60 mass%.

The total content of NK and BK per 100 wt.% Of the rubber component is preferably at least 10 wt.%, More preferably at least 20 wt.% And even more preferably at least 30 wt.%. Abrasion resistance tends to decrease when the total content is less than 10 wt.%. The total content is preferably not more than 70 wt.% And more preferably not more than 50 wt.%. The wet grip characteristics tend to decrease when the total content exceeds 70% by weight.

The rubber composition of the present invention is characterized by the content of silicon dioxide as a reinforcing filler. The amount (content) of silicon dioxide per 100 parts by weight the rubber component is preferably from 5 to 150 mass. and more preferably from 10 to 100 parts by weight Abrasion resistance will be insufficient when the amount of silicon dioxide is less than 5 parts by weight Machinability also tends to deteriorate when the amount of silica exceeds 150 parts by weight. One type of silica is used alone, or two or more kinds thereof are used in combination.

Silicon dioxide preferably has a specific surface area (N ₂ SA), determined by nitrogen adsorption, from 40 to 400 m ² / g, and more preferably from 60 to 360 m ² / g. If silicon dioxide has a specific surface area for nitrogen adsorption of less than 40 m ² / g, it is possible to obtain a small reinforcing effect and a decrease in abrasion resistance. If silicon dioxide has a specific surface area, determined by nitrogen adsorption, of more than 400 m ² / g, its dispersibility tends to deteriorate and hysteresis losses tend to increase, which leads to lower fuel economy.

The specific surface area of silicon dioxide determined by the nitrogen adsorption method is a value measured by the BET method in accordance with cASTM D3037-81.

The content of silicon dioxide per 100 wt.% The total content of silicon dioxide and soot is preferably not less than 60 wt.% And more preferably not less than 85 wt.%. The content of silicon dioxide is preferably not more than 98 wt.% And more preferably not more than 95 wt.%. If the silica content is in the indicated ranges, then a suitable balance of fuel economy, wet grip, and abrasion resistance can be achieved.

A silane coupling agent can be used along with the addition of silica. Examples of a silane coupling agent include:

bis (3-triethoxysilylpropyl) tetrasulfide,

bis (3-triethoxysilylpropyl) trisulfide,

bis (3-triethoxysilylpropyl) disulfide,

bis (3-triethoxysilylethyl) tetrasulfide,

bis (3-trimethoxysilylpropyl) tetrasulfide,

bis (2-trimethoxysilylethyl) tetrasulfide,

3-mercaptopropyltrimethoxysilane,

3-mercaptopropyltriethoxysilane,

2-mercaptoethyltrimethoxysilane,

2-mercaptoethyltriethoxysilane,

3-trimethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide,

3-triethoxysilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide,

2-triethoxysilylethyl-N, N-dimethylthiocarbamoyl tetrasulfide,

3-trimethoxysilylpropylbenzothiazole tetrasulfide,

3-triethoxysilylpropylbenzothiazolyltetrasulfide,

3-triethoxysilylpropyl methacrylate monosulfide,

3-trimethoxysilylpropyl methacrylate monosulfide,

bis (3-diethoxymethylsilylpropyl) tetrasulfide,

3-mercaptopropyl dimethoxymethylsilane,

dimethoxymethylsilylpropyl-N, N-dimethylthiocarbamoyl tetrasulfide; and dimethoxymethylsilylpropylbenzothiazole tetrasulfide.

Among examples, bis (3-triethoxysilylpropyl) tetrasulfide and 3-trimethoxysilylpropylbenzothiazolyltetrasulfide are preferred with respect to the hardening improvement effect. One of the silane coupling agents may be used alone, or two or more of them may be used in combination.

The amount of silane coupling agent per 100 parts by weight silica is preferably at least 1 part by weight and more preferably at least 2 parts by weight If the silane coupling agent is included in an amount of less than 1 part by weight, the resulting uncured rubber composition has a tendency to high viscosity and its workability has a tendency to deteriorate. The amount of silane coupling agent per 100 parts by weight silica is preferably not more than 20 parts by weight and more preferably not more than 15 parts by weight If the silane coupling agent is included in an amount of more than 20 parts by weight, the effect of the silane coupling agent associated with its amount will not be obtained, and the cost will increase.

Known additives can be used and examples thereof include vulcanizing agents such as sulfur; vulcanization accelerators such as thiazole-based vulcanization accelerators, thiuram-based vulcanization accelerators, sulfenamide-based vulcanization accelerators and guanidine-based vulcanization accelerators; vulcanization activators such as stearic acid and zinc oxide; organoperoxides; fillers such as carbon black, calcium carbonate, talc, aluminum dioxide, clay, aluminum hydroxide and mica; silane coupling agents; processing aids such as oil filler and lubricants; and antioxidants.

Examples of carbon black include various types of furnace black (carbon black), for example, SAF, ISAF, HAF, MAF, FEF, SRF, GPF, APF, FF, CF, SCF and ECF; acetylene black (carbon acetylene black); thermal carbon black (carbon black), for example, FT and MT; channel soot (carbon channel soot), for example, EPC, MPC and SS; and graphite. Each of these substances can be used as such or in combination of two or more substances. From the point of view of improving the balance of fuel economy, wet grip tires and abrasion resistance, carbon black content per 100 mass. parts of the rubber component is preferably not less than 1 mass. parts and more preferably not less than 3 mass. parts. The carbon black content is preferably not more than 30 mass. parts and more preferably not more than 10 mass. parts.

Carbon black typically has a specific surface area (N ₂ SA) for nitrogen adsorption of 5 to 200 m ² / g and the lower limit of the latter is preferably 50 m ² / g, while the upper limit of the latter is preferably 150 m ² / g. Soot typically has a dibutyl phthalate (DBP) adsorption of 5 to 300 ml / 100 g and the lower limit is preferably 80 ml / 100 g, while the upper limit is preferably 180 ml / 100 g. If soot has N ₂ SA or less DBP adsorption the lower limit of the range, it is likely to obtain a small strengthening effect and abrasion resistance to decrease. If the upper limit of the range is exceeded, soot will have poorer dispersibility and hysteresis losses will increase, which will lead to lower fuel economy. The specific surface area for nitrogen adsorption is measured in accordance with ASTM D4820-93, and the adsorption of DBP is measured in accordance with ASTM D2414-93. Applicable industrial products include those manufactured by Tokai Carbon Co., Ltd. under the trademarks SEAST 6, SEAST 7HM and SEAST KM, and Degussa products under the trademark CK3 and Special Black 4A and the like.

Examples of the oil filler include aromatic mineral oil (viscosity-weight constant (VVC value) = 0.900 to 1.049), naphthenic mineral oil (VVC value = 0.850 to 0.899) and paraffin mineral oil (VVC value = 0.790 to 0.849). The content of polycyclic aromatic compounds in the oil filler is preferably less than 3 wt.% And more preferably less than 1 wt.%. The content of polycyclic aromatic compounds is measured in accordance with the method of the British Petroleum Institute 346/92. In addition, the content of aromatic compounds (CA) of the filler oil is preferably not less than 20 wt.%. Two or more such oil fillers may be used in combination.

Examples of vulcanization accelerators include thiazole-based vulcanization accelerators, such as 2-mercaptobenzothiazole, dibenzothiazyl disulfide and N-cyclohexyl-2-benzothiazyl sulfenamide; thiuram-based vulcanization accelerators such as tetramethylthiuram monosulfide and tetramethylthiuram disulfide; sulfenamide-based vulcanization accelerators such as N-cyclohexyl-2-benzothiazole sulfenamide, N-t-butyl-2-benzothiazole sulfenamide, N-hydroxyethylene-2-benzothiazole sulfenamide and N, N'-diisopropyl-2-benzothiazole sulfenamide; and guanidine-based vulcanization accelerators such as diphenylguanidine, di-ortho-tolyl guanidine, and ortotolyl biguanidine. The amount to be used per 100 parts by weight the rubber component is preferably from 0.1 to 5 parts by weight and more preferably from 0.2 to 3 parts by weight

Known methods can be used to add other rubbers, additives and the like to the conjugated diene polymer to form a rubber composition. For example, a method can be used in which the components are mixed using a known mixer, for example, a screw mixer or a Banbury mixer.

Regarding the mixing conditions when adding additives other than vulcanizing agents and vulcanization accelerators, the mixing temperature is usually from 50 ° C to 200 ° C, preferably from 80 ° C to 190 ° C and the mixing time is usually from 30 s to 30 minutes preferably from 1 to 30 minutes

When a vulcanizing agent and a vulcanization accelerator are added, the mixing temperature is usually not more than 100 ° C. and preferably from room temperature to 80 ° C. The mixture, which includes a vulcanizing agent and a vulcanization accelerator, is usually subjected to a vulcanizing treatment, such as vulcanization in the press before use. The vulcanization temperature is usually from 120 ° C to 200 ° C and preferably from 140 ° C to 180 ° C.

The use of the rubber composition according to the present invention achieves a good balance of fuel economy, wet grip and abrasion resistance, along with a significant improvement in each of these properties.

The rubber composition of the present invention is suitable for use with various tire elements and is particularly well suited for treads.

The pneumatic tire of the present invention can be obtained from the rubber composition in the usual way. More specifically, the unvulcanized rubber composition, which optionally contains various additives, is extruded in the form of a tread of a tire and then placed in a conventional manner in a tire assembly machine and assembled with other tire elements to form an unvulcanized tire. This unvulcanized tire is subjected to heat and pressure in a vulcanizer to produce a pneumatic tire in accordance with the present invention.

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

EXAMPLES

The present invention is described in detail by the following examples.

The evaluation of the properties was carried out using the following properties. In subsequent evaluations, comparative example 1 was used as a comparative reference for examples 1-4 and comparative examples 2-4, and comparative example 5 was used as a comparative reference for comparison with example 5.

1. The content of vinyl bonds (unit: mol%)

The content of vinyl bonds in the polymer was determined using infrared spectral analysis, the intensity of the absorption band of approximately 910 cm ^-1 , which corresponds to the absorption peak of the vinyl group.

2. the content of styrene units (unit: mol%)

In accordance with the standard JIS K6383 (1995), the content of styrene units in the polymer was determined by the refractive index.

3. The distribution of molecular weight (Mw / Mn)

The weight average molecular weight (Mw) and number average molecular weight (Mn) were determined by gel permeation chromatography (GPC) under the conditions (1) - (8) below. Then, the molecular weight distribution (Mw / Mn) of the polymer was determined from the measured values of Mw and Mn.

(1) Device: HLC-8020 from Tosoh Corporation

(2) Separation columns: 2 × GMH-XL arranged in series - from Tosoh Corporation

(3) Measurement temperature: 40 ° C

(4) Carrier: tetrahydrofuran

(5) Flow rate: 0.6 ml / min.

(6) Injection amount: 5 ml

(7) Detector: differential refractometer

(8) Molecular Weight Standards: Polystyrene Standards

4.tanδ (tgδ)

A test sample was cut out in the form of a tape (1 mm or 2 mm × 40 mm long) from a sheet of vulcanized rubber compound and subjected to tests. Using a spectrometer from Ueshima Seisakusho Co., Ltd., tanδ was measured at a dynamic strain amplitude of 1%, a frequency of 10 Hz, and a temperature of 50 ° C. The inverse tanδ value was expressed as an indicator relative to the reference value for comparison (= 100). A larger numerical value indicates less rolling resistance and therefore better fuel economy.

5. Rolling Resistance

Rolling resistance was measured using a device for measuring rolling resistance when testing the tire on a rim 15 × 6JJ with an internal air pressure of 230 kPa, with a load of 3.43 kN at a speed of 80 km / h. The obtained value was expressed as an indicator relative to the value of the reference value for comparison (= 100). The higher the score, the better (better fuel economy).

6. Wet grip characteristics

The test tires were mounted on all wheels of the vehicle (applicant country, FF, engine displacement of 2000 cm ³ ) and the stopping distance was determined at an initial speed of 100 km / h on wet asphalt road surface. The obtained value was expressed as an indicator, the larger the numerical value, the better the sliding characteristics on a wet road surface (adhesion characteristics on a wet road surface). The determination of indicators was carried out using the following formula.

Sliding characteristics on a wet road surface = (braking distance of reference for comparison) / (Braking distance of a specific example or comparative example) × 100

7. Abrasion test using

The volume of losses of each vulcanized rubber compound was measured using the LAIP device (laboratory abrasion and sliding laboratory test device) under the following conditions: load of 50 N, speed of 20 km / h and a retraction angle of 5 °. The numerical values (LAIP indicator) presented in Tables 2 and 3 are values relative to the reference loss volume for comparison (= 100). The larger the value, the better the abrasion resistance.

Technological example 1 (polymer synthesis 1)

A stainless steel polymerization reactor with an internal volume of 20 L was washed, dried, and then purged with dry nitrogen. 10.2 kg of hexane (specific gravity = 0.68 g / cm ³ ), 547 g of 1,3-butadiene, 173 g of styrene, 6.1 ml of tetrahydrofuran and 5.0 ml of ethylene glycol diethyl ether were loaded into the polymerization reactor. Then, 11.1 mmol of bis (diethylamino) methylvinylsilane and 13.1 mmol of n-butyllithium were added in a cyclohexane solution and n-hexane solution, respectively, to initiate polymerization.

The copolymerization of 1,3-butadiene and styrene was carried out for three hours at a stirring speed of 130 rpm and a temperature inside the polymerization reactor of 65 ° C, with a continuous supply of monomers in the polymerization reactor. The amount of 1,3-butadiene and the amount of styrene loaded during the whole polymerization, respectively, were 821 g and 259 g.

Then, the resulting polymer solution was stirred at a speed of 130 rpm and 11.1 mmol of [3- (diethylamino) propyl] triethoxysilane was added and stirred for 15 minutes. Then a hexane solution (20 ml) containing 0.54 ml of methanol was added to the polymer solution and the resulting polymer solution was stirred for five minutes.

1.8 g of 2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (brand: Sumilizer GM from Sumitomo Chemical Co., Ltd. was added to the polymer solution. ) and 0.9 g pentaerythyl tetrakis (3-laurylthiopropionate) (trademark: Sumilizer TP-D from Sumitomo Chemical Co., Ltd.). Then, polymer 1 was removed from the polymer solution by steam stripping. Evaluation of the results for polymer 1 are presented in table 1. The number of structural units represented by formula (I) in the polymer, which was calculated based on the amount of starting materials introduced and loaded into the polymerization reactor, was 0.006 mmol / g-polymer (per unit mass of polymer).

Technological example 2 (polymer synthesis 2)

A stainless steel polymerization reactor with an internal volume of 5 L was washed, dried, and then purged with dry nitrogen. 2.55 kg of hexane (specific gravity = 0.68 g / cm ³ ), 137 g of 1,3-butadiene, 43 g of styrene, 1.5 ml of tetrahydrofuran and 1.2 ml of ethylene glycol diethyl ether were loaded into the polymerization reactor. Then 3.6 mmol of n-butyllithium in a solution of n-hexane was introduced and 1,3-butadiene and styrene were copolymerized for 2.5 hours. During the copolymerization reaction, the stirring speed was set to 130 rpm, the temperature inside the polymerization reactor was set to 65 ° C and monomers were continuously charged into the polymerization reactor. The amount of loaded 1,3-butadiene and the amount of loaded styrene, respectively, were 205 g and 65 g.

After polymerization for 2.5 hours, 2.8 mmol of bis (diethylamino) methylvinylsilane in a cyclohexane solution was introduced into the polymerization reactor with stirring at a speed of 130 rpm and a temperature inside the polymerization reactor of 65 ° C, followed by stirring for 30 minutes.

Then a hexane solution (20 ml) containing 0.14 ml of methanol was introduced into the polymerization reactor, and then the polymer solution was stirred for five minutes.

1.8 g of 2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (brand: Sumilizer GM from Sumitomo Chemical Co., Ltd. was added to the polymer solution. ) and 0.9 g pentaerythyl tetrakis (3-laurylthiopropionate) (trademark: Sumilizer TP-D from Sumitomo Chemical Co., Ltd.). Then, polymer 2 was recovered from the obtained polymer solution by steam stripping. Assessment of the results of polymer 2 are presented in table 1. The number of structural units represented by formula (I) in the polymer, which was calculated based on the amount of starting materials introduced and loaded into the polymerization reactor, was 0.006 mmol / g-polymer (per unit mass of polymer).

Technological example 3 (polymer synthesis 3)

A stainless steel polymerization reactor with an internal volume of 20 L was washed, dried, and then purged with dry nitrogen. 10.2 kg of hexane (specific gravity = 0.68 g / cm ³ ), 547 g of 1,3-butadiene, 173 g of styrene, 6.1 ml of tetrahydrofuran and 5.0 ml of ethylene glycol diethyl ether were loaded into the polymerization reactor. Then, 11.1 mmol of bis (diethylamino) methylvinylsilane and 13.1 mmol of n-butyllithium were added in a cyclohexane solution and n-hexane solution, respectively, to initiate polymerization.

The copolymerization of 1,3-butadiene and styrene was carried out for three hours at a stirring speed of 130 rpm and a temperature inside the polymerization reactor of 65 ° C, with a continuous supply of monomers in the polymerization reactor. The amount of 1,3-butadiene and the amount of styrene loaded during the whole polymerization, respectively, were 821 g and 259 g.

Then a hexane solution (20 ml) containing 0.54 ml of methanol was added to the polymer solution and the polymer solution was stirred for five minutes.

Then, 1.8 g of 2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (trademark: Sumilizer GM from Sumitomo Chemical Co., Ltd. Was added to the polymer solution. .) and 0.9 g of pentaerythyl tetrakis (3-laurylthiopropionate) (trademark: Sumilizer TP-D from Sumitomo Chemical Co., Ltd.). Then, polymer 3 was recovered from the obtained polymer solution by steam stripping. Evaluation of the results for polymer 3 are presented in table 1. The number of structural units represented by formula (I) in the polymer, which was calculated based on the amount of starting materials introduced and loaded into the polymerization reactor, was 0.006 mmol / g-polymer (per unit mass of polymer).

Technological example 4 (polymer synthesis 4)

A stainless steel polymerization reactor with an internal volume of 20 L was washed, dried, and then purged with dry nitrogen. 10.2 kg of hexane (specific gravity = 0.68 g / cm ³ ), 547 g of 1,3-butadiene, 173 g of styrene, 6.1 ml of tetrahydrofuran and 5.0 ml of ethylene glycol diethyl ether were loaded into the polymerization reactor. Then 13.1 mmol of n-butyllithium was introduced as a solution of n-hexane to initiate polymerization.

The copolymerization of 1,3-butadiene and styrene was carried out for three hours at a stirring speed of 130 rpm and a temperature inside the polymerization reactor of 65 ° C, with a continuous supply of monomers in the polymerization reactor. The amount of 1,3-butadiene and the amount of styrene loaded during the whole polymerization, respectively, were 821 g and 259 g.

Then, the resulting polymer solution was stirred at a speed of 130 rpm and 11.1 mmol of [3- (diethylamino) propyl] triethoxysilane was added and stirred for 15 minutes. Then a hexane solution (20 ml) containing 0.54 ml of methanol was added to the polymer solution and the polymer solution was stirred for five minutes.

1.8 g of 2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (brand: Sumilizer GM from Sumitomo Chemical Co., Ltd. was added to the polymer solution. ) and 0.9 g pentaerythyl tetrakis (3-laurylthiopropionate) (trademark: Sumilizer TP-D from Sumitomo Chemical Co., Ltd.). Then, polymer 4 was recovered from the obtained polymer solution by steam stripping. Evaluation of the results for polymer 4 are presented in table 1. Since polymer 4 was synthesized without using the compound represented by formula (III), polymer 4 does not contain structural units represented by formula (I).

Technological example 5 (polymer synthesis 5)

A stainless steel polymerization reactor with an internal volume of 20 L was washed, dried, and then purged with dry nitrogen. 10.2 kg of hexane (specific gravity = 0.68 g / cm ³ ), 547 g of 1,3-butadiene, 173 g of styrene, 6.1 ml of tetrahydrofuran and 5.0 ml of ethylene glycol diethyl ether were loaded into the polymerization reactor. Then, 13.1 mmol of n-butyllithium in n-hexane solution was introduced to initiate polymerization.

The copolymerization of 1,3-butadiene and styrene was carried out for three hours at a stirring speed of 130 rpm and a temperature inside the polymerization reactor of 65 ° C, with a continuous supply of monomers in the polymerization reactor. The amount of 1,3-butadiene and the amount of styrene loaded during the whole polymerization, respectively, were 821 g and 259 g.

Then a hexane solution (20 ml) containing 0.54 ml of methanol was added to the polymer solution and the polymer solution was stirred for five minutes.

1.8 g of 2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (brand: Sumilizer GM from Sumitomo Chemical Co., Ltd. was added to the polymer solution. ) and 0.9 g pentaerythyl tetrakis (3-laurylthiopropionate) (trademark: Sumilizer TP-D from Sumitomo Chemical Co., Ltd.). Then, polymer 5 was removed from the obtained polymer solution by steam stripping. Evaluation of the results of polymer 5 are presented in table 1. since polymer 5 was synthesized without using the compound represented by formula (III), polymer 5 does not contain structural units represented by formula (I).

Technological example 6 (polymer synthesis 6)

A stainless steel polymerization reactor with an internal volume of 20 L was washed, dried, and then purged with dry nitrogen. 10.2 kg of hexane (specific gravity = 0.68 g / cm ³ ), 547 g of 1,3-butadiene, 173 g of styrene, 6.1 ml of tetrahydrofuran and 5.0 ml of ethylene glycol diethyl ether were loaded into the polymerization reactor. Then, 11.1 mmol of bis (diethylamino) methylvinylsilane and 13.1 mmol of n-butyllithium were added in a cyclohexane solution and n-hexane solution, respectively, to initiate polymerization.

The copolymerization of 1,3-butadiene and styrene was carried out for three hours at a stirring speed of 130 rpm and a temperature inside the polymerization reactor of 65 ° C, with a continuous supply of monomers in the polymerization reactor. The amount of 1,3-butadiene and the amount of styrene loaded during the whole polymerization, respectively, were 821 g and 259 g.

Then, the resulting polymer solution was stirred at a speed of 130 rpm and 11.1 mmol of [3- (diethylamino) propyl] triethoxysilane was added and stirred for 15 minutes. Then a hexane solution (20 ml) containing 0.54 ml of methanol was added to the polymer solution and the polymer solution was stirred for five minutes.

Then, 1.8 g of 2-tert-butyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate (trademark: Sumilizer GM from Sumitomo Chemical Co., Ltd. Was added to the polymer solution. .) and 0.9 g of pentaerythyl tetrakis (3-laurylthiopropionate) (trademark: Sumilizer TP-D from Sumitomo Chemical Co., Ltd.). Then, the polymer solution was evaporated at ordinary temperature for 24 hours and then dried in vacuum at 55 ° C for 12 hours so that polymer 6 was obtained. The evaluation of the results for polymer 6 is shown in Table 1. The number of structural units represented by formula (I) in the polymer, which was calculated based on the amount of starting materials introduced and loaded into the polymerization reactor, was 0.006 mmol / g-polymer (per unit mass of polymer).

Table 1 Polymer 1 Polymer 2 Polymer 3 Polymer 4 Polymer 5 Polymer 6 The content of styrene units (wt.%) 25 25 24 25 24 25 The content of vinyl bonds (mol%) 59 59 60 59 58 60 Molecular Weight Distribution (Mw / Mn) 1,2 1,1 1,2 1,1 1,1 1,2

The chemical compounds used in the examples and comparative examples are described below.

Natural rubber: RSS # 3

Butadiene rubber: Ubepol BR150B from Ube Industries, Ltd.

Polymers 1-6: see process examples 1-6 above

Silica: Ultrasil VN3-G (N2SA: 175 m ² / g) by Degussa

Silane coupling agent: Si69 (bis (3-triethoxysilylpropyl) -tetrasulfide) from Degussa

Carbon black: Diablack N339 (N ₂ SA: 96 m ² / g, DBP adsorption: 124 ml / 100 g) from Mitsubishi Chemical Corporation

Oil: X-140 from Japan Energy Corporation

Antioxidant: Antigene 3C from Sumitomo Chemical Co., Ltd.

Stearic acid: Tsubaki stearic acid granules from NOF Corporation

Zinc Oxide: No. 1 Zinc Oxide from Mitsui Mining & Smelting Co., Ltd. Wax: Sunnoc N by Ouchi Shinko Chemical Industrial Co., Ltd. Sulfur: Sulfur powder from Tsurumi Chemical Industry Co., Ltd. Vulcanization Accelerator 1: Soxinol CZ from Sumitomo Chemical Co., Ltd. Vulcanization Accelerator 2: Soxinol D from Sumitomo Chemical Co., Ltd. (Examples 1-5 and comparative examples 1-5)

In accordance with each composition presented in table. 2 or 3, materials besides sulfur and vulcanization accelerators were mixed for 5 min at a temperature of 150 ° C using a Banbury mixer from Kobe Steel, Ltd. to obtain a mixed mixture. Sulfur and vulcanization accelerators were then added to the mixed mixture and mixed using an open type mixer for 5 minutes at 80 ° C. to obtain an unvulcanized rubber composition. The unvulcanized rubber composition was vulcanized under a press for 20 minutes at a temperature of 170 ° C. in a mold with a thickness of 0.5 mm to obtain a vulcanized rubber composition.

In addition, the unvulcanized rubber composition was formed in the form of a tread and assembled with other tire elements in a tire assembly machine to produce an unvulcanized tire. The unvulcanized tire was cured for 12 minutes at a temperature of 170 ° C to obtain a test tire (size: 195 / 65R15).

The resulting vulcanized rubber compounds and test tires were evaluated using the previously described test methods. In the table. 2 and 3 show the results of these tests. Tables A and B show the results of additional experiments.

As shown in tables 2 and 3, the rubber mixtures of the examples, each of which contained a polymer (polymer 1 or 6) containing a structural unit derived from a conjugated diene and a structural unit represented by formula (I), and containing an end group modified the compound represented by formula (II), provides a suitable balance of increased fuel economy, wet grip tires and abrasion resistance, compared with rubber mixtures obtained in

comparative examples.

From table A it is seen that a mixture of rubbers, including the claimed conjugated diene polymer, natural rubber and butadiene rubber in certain quantities, allows to obtain a well-balanced improvement in fuel economy, wet grip and abrasion resistance.

So, example 1 and experiments 1-1 to 1-4, including mixtures of rubbers, including the claimed conjugated diene polymer, NK and BK in the declared amounts, demonstrate a good overall efficiency indicator (rolling resistance, wet grip and abrasion resistance) from 130 to 132. On the other hand, the overall performance indicator of comparative examples 1-1 to 1-4 (from 122 to 126), including the claimed conjugated diene polymer, NK and BK, but in amounts outside the stated ranges, worse than for performance indicator in example 1 and experiments 1-1 to 1-4.

It can be seen from the attached table B that a mixture comprising silicon dioxide in the declared amounts of 10 to 100 parts can provide well-balanced improvements in fuel economy, wet grip performance and abrasion resistance.

So, in experiment 2 according to the invention and in comparative experiment 2 with 10 parts of silicon dioxide, the overall efficiency indicator of experiment 1, which is 123, turned out to be better than the overall efficiency indicator of experiment 2, which is 100. A similar result was obtained in experiment 3 according to the invention and comparative example 3 with 100 parts of silica.

Claims (6)

1 Rubber compound comprising a rubber component and silicon dioxide,
in which the rubber component contains from 30 to 90 mass. % conjugated diene polymer per 100 mass. % rubber component
the conjugated diene polymer contains a structural unit derived from a conjugated diene and a structural unit represented by the following formula (I):

in which each X ¹ , X ² and X ³ independently represents a hydroxyl group or a C _1-4 alkyl group, and at least one of X ¹ , X ² and X ³ is a hydroxyl group,
moreover, at least one of the end groups of the conjugated diene polymer is modified by a compound represented by the following formula (II):

in which n is an integer from 1 to 10; each R ³ , R ⁴ and R ⁵ independently represents a C _1-3 alkyl group or a C _1-3 alkoxy group and at least one of R ³ , R ⁴ and R ⁵ is a C _1-3 alkoxy group; and A represents a group represented by formula (IIa):

in which each R ⁶ and R ⁷ independently represents a C _1-6 alkyl group, and
where the rubber component further comprises natural rubber and butadiene rubber, and the content of natural rubber is from 5 to 60 mass. %, and the content of butadiene rubber is from 5 to 60 mass. % and
silicon dioxide is contained in an amount of from 10 to 100 mass. hours per 100 mass. including rubber component. 2. The rubber composition according to claim 1, in which two of X ¹ , X ² and X ³ in the formula (I) are a hydroxyl group. 3. The rubber mixture according to claim 1, in which the content of vinyl bonds in the conjugated diene polymer is at least 10 mol%, but does not exceed 80 mol%. per 100 mol%. structural units derived from conjugated diene. 4. The rubber mixture according to claim 1, in which the specific surface area of silicon oxide, determined by the method of adsorption of nitrogen, is from 40 to 400 m ² / year 5. The rubber composition according to claim 1, which is intended for use as a rubber composition for a tread. 6. The pneumatic tire obtained from the rubber composition according to claim 1.