JP2000038423A - Conjugated diolefin copolymer rubber and rubber composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a diolefin copolymer rubber having good processability and improved low-hysteresis loss and wet-skid characteristics without lowering the abrasion resistance and breaking characteristics. SOLUTION: The objective conjugated diolefin copolymer rubber satisfies the following conditions. (1) The copolymer is produced by the copolymerization of a conjugated diolefin and an aromatic vinyl compound; (2) not less than 70% of the polymer chain in the total polymer chain has amino group on the polymerization starting terminal; (3) the content of bonded aromatic vinyl compound is 5-55 wt.%; (4) the amount of single aromatic vinyl compound unit composed of singly bonded aromatic vinyl compound is >=50 wt.% based on the total bonded aromatic vinyl compound; (5) the amount of long-chain aromatic vinyl compound unit composed of >=8 aromatic vinyl compounds bonded to form a chain is <10% based on the total bonded aromatic vinyl compound; and (6) the molecular weight distribution is monomodal and the ratio of weight- average molecular weight (Mw) to number-average molecular weight (Mn) (Mw/Mn) is >=1.3 and <3.0.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a conjugated diolefin-based copolymer rubber and a rubber composition.

[0002]

2. Description of the Related Art In response to recent demands for low fuel consumption of automobiles, a rubber material for tires has low rolling resistance, excellent wear resistance and breaking characteristics, and also has steering stability performance represented by wet skid resistance. The development of conjugated diolefin rubbers has been desired.

Recently, there has been proposed a method of using a rubber composition in which silica or a mixture of silica and carbon black is blended with a reinforcing agent as a rubber material for tires. A tire tread containing silica or a mixture of silica and carbon black has low rolling resistance and good steering stability typified by wet skid resistance, but has the problem of low tensile strength and low wear resistance of the vulcanizate. And the viscosity of the compounded rubber is higher than that of the rubber composition containing only carbon black.
Extrusion characteristics). Further, the deterioration of workability has led to a problem that processing cost is increased.

In order to improve the tensile strength and abrasion resistance of a vulcanizate containing silica or a mixture of silica and carbon black, various rubber compositions containing a polymer having a functional group compatible with silica have been introduced. Proposed. For example, Japanese Patent Publication No. 49-36957 proposes a method of producing a polymer by reacting silicon tetrahalide, trihalosilane and the like. Japanese Patent Publication No. 52-5071 discloses a method for producing a polymer modified with a halogenated silane compound. JP-A-1-18850
No. 1 discloses a diene rubber into which an alkylsilyl group has been introduced, and JP-A-5-230286 discloses a diene rubber into which a halogenated rusili group has been introduced. By using these modified polymers in a composition containing silica or a mixture of silica and carbon black, some improvement in physical properties can be seen, but the vulcanizate still has a sufficient improvement in tensile strength and abrasion resistance. Was not. Also,
Use of the above-mentioned polymer having a functional group which has an affinity for silica is not preferred because the processability tends to be further deteriorated.

Further, the above-mentioned conventionally known modified polymers are mainly suitable for blending silica, and when blending a mixture of silica and carbon black, the hysteresis loss is increased as the mixing ratio of carbon black increases. The effect of reducing the tensile strength and the effect of improving the tensile strength and wear resistance were reduced. In order to solve this problem, an effective modified polymer has been eagerly desired in both a silica compound and a mixture of silica and carbon black.

As an effective modified polymer in both the silica compound and the carbon black compound, a polymer into which an amino group is introduced is considered. For example, diene rubbers having an amino group introduced therein have been proposed as polymers for blending silica in JP-A-1-101344, JP-A-64-22940 and JP-A-9-71687. Further, regarding the compounding of carbon black, (1) a polymer having an amino group introduced into a polymerization terminal using a lithium amide initiator (JP-A-59-38209, JP-B-5-38209)
1298, JP-A-6-279515, JP-A-6-1
No. 99923 and JP-A-7-53616)
(2) The styrene-butadiene copolymer having various structures polymerized with an organolithium initiator is terminated with a urea compound (see JP-A-61-27338) and a dialkylaminobenzophenone compound (see JP-A-58-1983). 162604
And Japanese Patent Application Laid-Open No. 58-189203) have been proposed.

By using the polymers obtained by these methods, various improvements in physical properties have been achieved to some extent in the respective formulations of silica and carbon black. However, the above-mentioned documents mainly describe a method for introducing an amino group into a polymer in detail,
No mention was made of the relationship between the structure of the polymer itself and each of the properties, except for general matters.

[0008]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a diolefin copolymer having an amino group introduced at the terminal of a polymer, a bonding unit of a specific aromatic vinyl compound and a specific GPC molecular weight distribution. It is to provide coalescence. Another object of the present invention is to provide good workability in any combination of carbon black, silica and carbon black or carbon black, and to provide low hysteresis loss without impairing abrasion resistance and fracture characteristics. sex,
It is an object of the present invention to provide a novel diolefin-based copolymer rubber which has improved wet skid properties and can be used as a tread material for fuel-efficient tires, large tires, and high-performance tires.

Another object of the present invention is to provide a rubber composition comprising the copolymer rubber of the present invention and a specific filler and exhibiting the above-mentioned excellent performance. Still other objects and advantages of the present invention will become apparent from the following description.

[0010]

Means for Solving the Problems In order to solve the above problems, the present inventors have intensively studied the structural factors of a diolefin copolymer having an amino group introduced at the terminal of the polymer. As a result, a diolefin copolymer having a specific aromatic vinyl compound chain structure and a specific GPC molecular weight distribution has good workability in any of the carbon black and silica blends, and has abrasion resistance. The present inventors have found that the balance between low hysteresis loss and wet skid characteristics is improved without impairing the breaking characteristics, and the present invention has been completed.

That is, the above objects and advantages of the present invention are as follows. First, (1) a polymer obtained by copolymerizing a conjugated diolefin and an aromatic vinyl compound, and (2) a total polymer At least 70% of the polymer chain has an amino group at the polymerization start end of the polymer chain, (3) the amount of the bound aromatic vinyl compound is 5 to 55% by weight, and (4) the aromatic vinyl compound alone The linked, single-chain aromatic vinyl compound unit is 50% by weight or more based on the bonded aromatic vinyl compound, and (5) the long-chain aromatic vinyl compound unit having eight or more bonded aromatic vinyl compounds connected is: Less than 10% based on the bound aromatic vinyl compound, and (6) the molecular weight distribution is monomodal and the ratio Mw / Mn of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 1.3 or more, .
It is achieved by a conjugated diolefin-based copolymer rubber, which is less than 0.

Hereinafter, the present invention will be described in detail. The conjugated diolefin-based copolymer rubber of the present invention is a polymer obtained by copolymerizing a conjugated diolefin and an aromatic vinyl compound, and at least 70% of the polymer chain has an amino group at the polymerization initiation terminal. have. As the conjugated diolefin compound used in the present invention, for example, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-
Chloro-1,3-butadiene, 1,3-pentadiene and mixtures thereof and the like.

The aromatic vinyl compounds include, for example, styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, α-methylstyrene, 2,4
-Dimethylstyrene, 2,4-diisopropylstyrene, 4-tert-butylstyrene, divinylbenzene, vinylbenzyldimethylamine, vinylbenzyldimethylaminoethanolamine, N, N-dimethylaminoethylstyrene, tert-butoxystyrene, vinylpyridine and the like Can be mentioned. Of these, styrene is preferred.

The content of the bound aromatic vinyl compound is from 5 to 55% by weight, based on the copolymer. Preferably, it is at least 10% by weight and less than 50% by weight. When the content of the bound aromatic vinyl compound is less than 5% by weight, the obtained copolymer has poor wet skid properties, abrasion resistance and fracture properties. On the other hand, if it exceeds 55% by weight, the balance between hysteresis loss and wet skid characteristics of the obtained copolymer is deteriorated.

The content of 1,2-bonds and / or 3,4-bonds (hereinafter, vinyl bonds) in the conjugated diolefin portion of the polymer is not particularly limited.
It is preferable that it is above. Further, it is difficult to produce a copolymer having a vinyl bond exceeding 90% by a usual synthesis method for producing a copolymer of an aromatic vinyl compound and a conjugated diolefin. A more preferred range of the vinyl bond is 1
5% to 85%.

The amino group introduced into the polymerization initiation terminal of at least 70% of the total polymer chains of the polymer of the present invention includes the following formulas (a1) and (a2)

General formula (a1):

Embedded image (In the formula, R ¹ and R ² are the same or different and are a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms.)

General formula (a2):

Embedded image (Wherein, R ³ and R ⁴ are an alkylene group having 1 to 3 carbon atoms, X is —CH ₂ —, —O—, or —NH—,
R ⁵ is a hydrogen atom or an alkyl group having 1 to 5 carbon atoms, and k is an integer of 1 to 4. )

And the group represented by Examples of the group represented by the formula (a1) include a dimethylamino group, a diethylamino group, a dipropylamino group, and a di-n
-Butylamino group, diisobutylamino group, dipentylamino group, dihexylamino group, di-n-butylamino group, diheptylamino group, dioctylamino group, diallylamino group, dicyclohexylamino group, butylisopropylamino group, dibenzylamino Group, methylbenzylamino group, dibenzylamino group, methylhexylamino group and ethylhexylamino group. Examples of the group represented by the above formula (a2) include a trimethyleneimino group, a tetramethyleneimino group, a 2-methyltetramethyleneimino group, a 3-methyltetramethyleneimino group, a pentamethyleneimino group, a 2-methyl Pentamethyleneimino group, 3-methylpentamethyleneimino group, 4-methylpentamethyleneimino group, 3,5-dimethylpentamethyleneimino group, 2-ethylpentamethyleneimino group, hexamethyleneimino group, heptamethyleneimino group, dodeca Examples include a methyleneimino group. The introduction ratio of these functional groups to the polymerization initiation terminal is 7
If it is less than 0%, the hysteresis loss characteristics, abrasion resistance, and breaking characteristics of the obtained copolymer are not sufficiently improved, which is not preferable.

The polymer of the present invention has (a)
The method for introducing the amino group represented by 1) and / or (a2) is not particularly limited, and examples thereof include the following method.

Method (1): After reacting an organic alkali metal compound with a vinyl compound or a conjugated diolefin compound having a functional group having the structure of (a1) and / or (a2) in a hydrocarbon solvent, A method of copolymerizing a diolefin and an aromatic vinyl compound.

(A1) used in the method (1) and / or
Alternatively, examples of the vinyl compound having a functional group having the structure of (a2) include p-dimethylaminostyrene, p-diethylaminostyrene, p-dimethylaminomethylstyrene, p- (2-dimethylaminoethyl) styrene, and m-
(2-dimethylaminoethyl) styrene, p- (2-diethylaminoethyl) styrene, p- (2-dimethylaminovinyl) styrene, p- (2-diethylaminovinyl) styrene, 2-vinylpyridine, 4-vinylpyridine and 2-vinyl-5-ethylpyridine and the like can be mentioned.

Method (2): (a1) and / or (a)
A reaction product of a secondary amine compound having the structure of 2) and an organic alkali metal compound, or (a1) and / or
Or a method of copolymerizing a conjugated diolefin and an aromatic vinyl compound using an alkali metal amide compound having the structure (a2) as a polymerization initiator.

The secondary amine compound having the structure (a1) used in the method (2) includes, for example, dimethylamine, diethylamine, dipropylamine, di-n-butylamine, di-sec-butylamine, dipentylamine, Dihexylamine, di-n-octylamine, di-
Examples thereof include (2-ethylhexyl) amine, dicyclohexylamine, N-methylbenzylamine, and diallylamine. Examples of the secondary amine compound having the structure (a2) include morpholine, piperazine, 2,6-dimethylmorpholine, 2,6-dimethylpiperazine, 1-ethylpiperazine, 2-methylpiperazine, 1-benzylpiperazine, Piperidine, 3,3-
Dimethylpiperidine, 2,6-dimethylpiperidine, 1
-Methyl-4- (methylamino) piperidine, 2,2,
6,6-tetramethylpiperidine, pyrrolidine, 2,5-
Examples thereof include dimethylpyrrolidine, azetidine, hexamethyleneimine, heptamethyleneimine, 5-benzyloxyindole, 3-azaspiro [5,5] undecane, 3-azabicyclo [3,2,2] nonane and carbazole. (A1) and / or (a2)
The alkali metal amide compound having the structure of (a)
The hydrogen atom (H) of the secondary amine compound having the structure of 1) and / or (a2) is replaced with an alkali metal (Li, N
a, K, Rb, Sc).

Method (3): (a1) and / or (a)
A reaction product of a tertiary amine compound having the structure of 2) and an organic alkali metal compound, or (a1) and / or
Or a method of copolymerizing a conjugated diolefin and an aromatic vinyl compound using an organic alkali metal compound having the structure of (a2) as a polymerization initiator.

The tertiary amine compound having the structure (a1) used in the method (3) includes, for example, N, N-dimethyl-o-toluidine, N, N-dimethyl-p-toluidine, N, N- Dimethyl-m-toluidine, α-picoline, β-picoline, γ-picoline, and the like.

The tertiary amine compound having the structure (a2) includes, for example, N, N-tetramethylene-o-
Toluidine, N, N-heptamethylene-o-toluidine, N, N-hexamethylene-o-toluidine and the like. The organic alkali metal compound having the structure of (a1) and / or (a2) is the same as the above (a1) and / or
Alternatively, one of the hydrogen atoms (H) of the tertiary amine compound having the structure (a2) is replaced with an alkali metal (Li, Na, K,
Rb, Sc).

Here, (a1) and / or (a2)
When copolymerizing a conjugated diolefin and an aromatic vinyl compound using a reaction product of a secondary amine compound having a structure of or a tertiary amine compound and an organic alkali metal compound as a polymerization initiator, As the organic alkali metal compound to be reacted with the tertiary amine compound or the tertiary amine compound, an organic lithium compound is preferable. Specific examples include ethyllithium, propyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, hexyllithium, and mixtures thereof. Of these, n-butyllithium and sec-butyllithium are preferred.

The reaction between the secondary amine compound or the tertiary amine compound and the organic alkali metal compound is carried out by an amino group (NH) in the structure of the secondary amine compound or in the structure of the tertiary amine compound. The molar ratio between the active hydrogen and the organic alkali metal compound must be in the range of 1: 0.2 to 5.0, preferably 0.5 to 2.0, and more preferably 0.8 to 1.0. .2. If the molar ratio of the organic alkali metal compound exceeds 5.0 with respect to the amino group (NH) in the structure of the secondary amine compound or the active hydrogen in the structure of the tertiary amine compound, the breaking strength and the wear resistance will increase. sex,
The effect of improving low hysteresis cannot be obtained. On the other hand, when the molar ratio of the organic alkali metal compound is less than 0.2, the polymerization rate is remarkably reduced, the productivity is significantly reduced, and the modification efficiency at the time of modifying the polymer terminal with a functional group is reduced. descend.

Further, a secondary amine compound or a tertiary amine compound
The reaction between a secondary amine compound and an organic alkali metal compound is as follows:
Prior to the polymerization, the reaction may be carried out in a reaction pot separate from the polymerization vessel and charged to the polymerization vessel, or a secondary amine compound or a tertiary amine compound and an organic alkali metal may be charged in the presence of a monomer. The polymerization may be carried out by reacting the compound with the compound and using the product as an initiator.

The reaction between the secondary amine compound or the tertiary amine compound and the organic alkali metal compound basically proceeds instantaneously, but a ripening time of 1 to 180 minutes may be provided. Since the product of this reaction is relatively stable under a nitrogen atmosphere, it may be used immediately after the reaction or used after storage for about 10 days to 2 weeks. The reaction between the secondary amine compound or the tertiary amine compound and the organic alkali metal compound is 0 to 120.
It is desirable to carry out in a temperature range of ° C.

In the polymerization vessel, the second monomer is used in the presence of a conjugated diolefin monomer and an aromatic vinyl compound monomer.
A mode in which a reaction between a tertiary amine compound or a tertiary amine compound and an organic alkali metal compound is carried out, followed by polymerization may be employed. The reaction temperature at this time coincides with the polymerization initiation temperature, but can be arbitrarily selected in a temperature range of 0 to 120 ° C.

The copolymer of the present invention has an aromatic vinyl compound alone, the content of a single-chain aromatic vinyl compound unit is 50% by weight or more based on the bound aromatic vinyl compound, One of the features is that the content of the long-chain aromatic vinyl compound unit in which eight or more compounds are linked is less than 10% based on the bound aromatic vinyl compound. The preferred content of the single-chain aromatic vinyl compound unit is 55% by weight or more, and the preferred content of the long-chain aromatic vinyl compound unit is less than 5% by weight. The linkage chain length of the aromatic vinyl compound can be measured by an ozonolysis-gel permeation chromatography method developed by Tanaka et al. (Tanaka et al., Polymer, V.
ol.22, P.1721-1723, 1981.). If the aromatic vinyl compound alone is linked, the single-chain aromatic vinyl compound unit is less than 50% by weight, or the long-chain aromatic vinyl compound unit having eight or more aromatic vinyl compounds linked is 10% by weight or more, The low hysteresis loss property of the resulting copolymer is inferior. The polymer of the present invention has a monomodal molecular weight distribution (monomodal type), and the ratio Mw / Mn of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 1.3 or more;
It is less than 0.

Even if the molecular weight distribution is monomodal (monomodal type), if the molecular weight distribution is narrow (Mw / Mn is less than 1.3), the viscosity when compounded with a reinforcing agent or other compounding agent is high. And workability deteriorates. Deterioration of the processability of the compound not only increases the processing cost, but also causes poor dispersion of the reinforcing agent and other compounding agents, leading to deterioration in the physical properties of the compound. If the molecular weight of raw rubber is reduced to lower the viscosity of the compound, the low-loss property of the compound worsens, the viscosity of the rubber increases, the handling becomes poor, and the cold flow increases, and the storage stability increases. Worsens. Further, even if Mw / Mn is 1.3 or more and less than 3.0, if the molecular weight distribution is multimodal (polymodal type), sufficient workability cannot be obtained.

The molecular weight distribution of the copolymer of the present invention is monomodal (monomodal type), and the ratio Mw / Mn of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 1.3 or more. The method for setting the value to less than 0 is not particularly limited, and for example, the following method is available.

(Method-1) Polymerization is performed while continuously charging a solvent, a monomer, a polymerization initiator and, if necessary, an ether compound and a tertiary amine compound in a polymerization system [continuous polymerization method]. Here, the polymerization initiator refers to (a1) and / or
Or a vinyl compound having a functional group having the structure of (a2),
Or a reaction product of a conjugated diolefin compound and an organic alkali metal compound, or (a1) and / or (a
Reaction product of a secondary amine compound having the structure of 2) and an organic alkali metal compound, or a specific tertiary amine compound having a functional group of the structure of (a1) and / or (a2) and an organic alkali metal It means the reaction product with the compound. A vinyl compound having a functional group having the structure of (a1) and / or (a2), a reaction product of a conjugated diolefin compound and an organic alkali metal compound, a reaction product of a secondary amine compound and an organic alkali metal compound, Alternatively, the reaction between the specific tertiary amine compound and the organic alkali metal compound may be performed in a separate reaction pot from the polymerization vessel before the polymerization, and the polymerization vessel may be charged continuously. A vinyl compound or a conjugated diolefin compound having a functional group having the structure of (a1) and / or (a2), a secondary amine compound, or a tertiary amine compound and an organic alkali metal compound are continuously placed in a polymerization vessel simultaneously with the monomer. It is also possible to carry out the reaction by charging the product in a continuous manner and to carry out the polymerization using the product as an initiator [continuous polymerization system].

(Method-2) A solvent, a polymerization initiator and, if necessary, an ether compound and a tertiary amine compound are charged into the polymerization system in advance, and only the monomer is charged continuously or intermittently to perform polymerization. [Continuous addition method of monomer].

Here, the polymerization initiator is a reaction product of a vinyl compound having a functional group having the structure of (a1) and / or (a2) or a conjugated diolefin compound with an organic alkali metal compound, or (a1) and / Or (a
Reaction product of a secondary amine compound having the structure of 2) and an organic alkali metal compound, or a specific tertiary amine compound having a functional group of the structure of (a1) and / or (a2) and an organic alkali metal The reaction product with the compound may be prepared and used in a separate pot other than the polymerization vessel before the polymerization, or (a1) and / or in the polymerization vessel before charging the monomer continuously or intermittently. Or a vinyl compound or a conjugated diolefin compound having a functional group having the structure of (a2), or a secondary amine compound having a structure of (a1) and / or (a2) or a structure of (a1) and / or (a2) May be prepared by reacting a specific tertiary amine compound having a functional group with an organic alkali metal compound.

In the copolymer of the present invention, at least 40% of the total polymer chains have (a)
An isocyanate compound and / or an isothiocyanate compound, (b) an amide compound and / or an imide compound, (c) a pyridyl-substituted ketone compound and / or a pyridyl-substituted vinyl compound, (d) a silicon compound,
At least one selected from the group consisting of (e) an ester compound, (f) a ketone compound and (g) a tin compound
Modification or coupling with a kind of compound (modifying agent) is advantageous in terms of the physical properties of the polymer (for example, reducing hysteresis loss or improving abrasion resistance and breaking strength), as well as productivity. Is also preferred.

Of these compounds, specific examples of the isocyanate compound and the thioisocyanate compound as the component (a) include phenyl isocyanate, 2,4-
Tolylene diisocyanate, 2,6-tolylene diisocyanate, diphenylmethane diisocyanate, polymeric diphenylmethane diisocyanate (C
-MDI), isophorone diisocyanate, hexamethylene diisocyanate, 1,3,5-benzenetriisocyanate and phenyl-1,4-diisothiocyanate.

Specific examples of the amide compound and the imide compound as the component (b) include succinamide, phthalamide, N, N, N ', N'-tetramethylphthalamide, oxamide, N, N, Amide compounds such as N ′, N′-tetramethyloxamide, succinimide, N-methylsuccinimide, maleimide, N-methylmaleimide,
Examples include imide compounds such as phthalimide and N-methylphthalimide.

Specific examples of the pyridyl-substituted ketone compound and the pyridyl-substituted vinyl compound as the component (c) include:
Examples include dibenzoylpyridine, diacetylpyridine, divinylpyridine and the like.

The amount of the components (a) to (c) used is usually 0.1% based on the functional groups such as isocyanate group, isothiocyanate group, carbonyl group and vinyl group per 1 g atom equivalent of lithium atom. It is 2 to 10 equivalents, preferably 0.5 to 5.0 equivalents. If it is less than 0.2 equivalent, the effects of the resilience and low heat generation of the vulcanized rubber tend to be inferior.
Exceeding the equivalent amount is not preferred because unreacted substances are increased and an odor is generated, the vulcanization speed is increased, and the resilience of the vulcanized rubber and the effect of low heat generation are reduced.

Specific examples of the silicon compound as the component (d) include dibutyldichlorosilicon, methyltrichlorosilicon, methyldichlorosilicon, tetrachlorosilicon, triethoxymethylsilane, and triphenoxymethylsilane. 0.05 to 5 equivalents, preferably 0.1 to 5 equivalents per 1 g of lithium atom, based on the halogen atom, phenoxy group and ester group.
It can be added in a range of 1.5 equivalents.

Specific examples of the ester compound as the component (e) include diethyl adipate, diethyl malonate, diethyl phthalate, diethyl glutarate and diethyl maleate. It can be added in the range of 0.05 to 1.5 equivalents per 1 g atom equivalent of lithium atom.

Specific examples of the ketone compound as the component (f) include N, N-dimethyl-1-aminobenzoquinone, N, N, N ', N'-tetramethyl-1,3-diaminobenzoquinone, N, N N-dimethyl-1-aminoanthraquinone and N, N, N ', N'-tetramethyl-1,4
-Diaminoanthraquinone, N, N, N ', N'-tetramethyl-4,4'-aminobenzophenone, N, N,
N ', N'-tetraethyl-4,4'-aminobenzophenone and the like can be mentioned. These can be added in a range of 0.05 to 5 equivalents per 1 g atom equivalent of lithium atom.

Specific examples of the tin compound as the component (g) include tetrachlorotin, tetrabromotin, trichlorobutyltin, trichloromethyltin, trichlorooctyltin, dibromodimethyltin, dichlorodimethyltin, dichlorodibutyltin, and dichlorodioctyl. Tin,
1,2-bis (trichlorostannyl) ethane, 1,2-bis (methyldichlorostannylethane), 1,4-bis (trichlorostannyl) butane, 1,4-bis (methyldichlorostannyl) butane, Examples include ethyltin tristearate, butyltin trisoctanoate, butyltin tristearate, butyltin trislaurate, dibutyltin bisoctanoate, dibutyltin bisstearate, and dibutyltin bislaurate. The amount of the component (k) added is 1 g of lithium atom.
The range of 0.05 to 5 equivalents per atomic equivalent is preferably based on a halogen atom or a carboxylate group.

The polymerization conversion of these copolymers is 90-1.
Compounds added and reacted at the time of 00% can be used alone or in combination of two or more. In addition, in order to increase the reaction efficiency of the polymerization active terminal and the above compound, after producing the copolymer, the polymerization system further contains 1,3-butadiene in an amount of 0.5 to 500 mol, preferably 1 to 500 mol per 1 g of lithium atom. It is preferable to carry out the terminal modification reaction after adding 200 mol.

Among the above compounds, (a) isocyanate compounds and / or isothiocyanate compounds,
When (d) a silicon compound, (e) an ester compound, (f) a ketone compound, and (g) a tin compound are used, wear resistance, low hysteresis performance, and wet skid performance, which are the objects of the present invention, are represented. It has an excellent effect on improving steering stability and high breaking strength, and a copolymer suitable for low fuel consumption tires, large tires, or high-performance tires can be obtained. Extenders and liquid rubbers can be added to the copolymers modified or coupled with these compounds. Further, among the above compounds, (d) a silicon compound,
(G) When a tin compound is used, there is also an excellent effect on the improvement of workability aimed at by the present invention, which is particularly preferable. In the present invention, the polymer whose terminal is modified or coupled needs to be contained in an amount of 40% by weight or more, preferably 70% by weight or more in the whole polymer. If it is less than 40% by weight, the breaking strength and the low hysteresis performance are inferior and are not preferred.

The polymerization reaction and the modification or coupling reaction for obtaining the polymer of the present invention are usually carried out at 0 to 120.
The reaction is performed in a temperature range of ° C., and may be performed under a constant temperature condition or a rising temperature condition. The polymerization system may be either a batch polymerization system or a continuous polymerization system, and the polymerization is performed while continuously charging the above-mentioned solvent, monomer, polymerization initiator and, if necessary, the ether compound and the tertiary amine compound ( Although it is preferable to employ a method (method-1; continuous polymerization method), a polymer of the same quality can be obtained by adopting a method (method-2) in which only the monomer is charged continuously or intermittently and polymerized. Is possible.

Further, if necessary, diethyl ether,
Di-n-butyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, propylene glycol diethyl ether, diethylene glycol dimethyl ether, tetrahydrofuran, α-methoxytetrahydrofuran, dimethoxybenzene, dimethoxyethane, tetrahydrofurfuryl methyl ether,
Ether compounds such as tetrahydrofurfurylethyl ether, 2,2-bistetrahydrofurfurylpropane and / or triethylamine, pyridine, N, N,
Tertiary amine compounds such as N ′, N′-tetramethylethylenediamine, dipiperidinoethane, N, N-diethylaminoethanol ethyl ether are added to the polymerization system to form a diolefin (co) polymer. The microstructure (vinyl bond content) of the conjugated diolefin moiety can be adjusted.

Examples of the hydrocarbon solvent used when polymerizing the conjugated diolefin copolymer of the present invention include pentane, hexane, heptane, octane, methylcyclopentane, cyclohexane, benzene, xylene and the like.

When the reactivity of the initiator used in the present invention is to be improved, or when the aromatic vinyl compound introduced into the polymer is randomly arranged or a single chain of the aromatic vinyl compound is added. A potassium compound may be added together with the polymerization initiator. Examples of the potassium compound added together with the polymerization initiator include potassium isopropoxide, potassium-t-butoxide, potassium-t-amyloxide, potassium-n-heptaoxide,
Potassium benzyl oxide, potassium phenoxide, potassium alkoxide and potassium phenoxide; potassium such as lauric acid such as isovaleric acid and caprylic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, benzoic acid, phthalic acid and 2-ethylhexanoic acid Salts, potassium salts of organic sulfonic acids such as dodecylbenzenesulfonic acid, tetradecylbenzenesulfonic acid, hexadecylbenzenesulfonic acid, octadecylbenzenesulfonic acid; diethyl phosphite, diisopropyl phosphite, diphenyl phosphite, phosphorous acid For example, potassium salts of organic phosphorous acid such as dibutyl and dilauryl phosphite are used.

These potassium compounds can be added in an amount of 0.005 to 0.5 mol per 1 gram atomic equivalent of lithium of the organolithium compound used for forming the initiator. If the amount is less than 0.005 mol, the effect of adding the potassium compound (improvement of the reactivity of the initiator, randomization of the aromatic vinyl compound or addition of a single chain) does not appear, whereas if it exceeds 0.5 mol, the polymerization activity is reduced. In addition, the productivity is greatly reduced, and the modification efficiency at the time of carrying out the reaction for modifying the terminal of the polymer with a functional group is reduced, or a gelling reaction is caused.

When polymerizing the polymer of the present invention using an alkali metal amide initiator, the polymerization reaction activity is improved,
A lithium alkoxide compound may be added together with the polymerization initiator for the purpose of improving the reaction efficiency between the polymer active terminal and the modifying agent (coupling agent). The lithium alkoxide compound can be prepared by reacting an alcohol having a corresponding structure with an organic lithium compound or metallic lithium. When a batch polymerization method is employed, the lithium alkoxide compound may be prepared in the presence of the monomer before copolymerizing the conjugated diolefin and the aromatic vinyl compound in a hydrocarbon solvent. Examples of the alkali metal alkoxide compound include lithium alkoxides such as tetrahydrofurfuryl alcohol, N, N-dimethylethanolamine, N, N-diethylethanolamine and 1-piperazineethanolamine.

Examples of the organolithium compound to be reacted with an alcohol compound to form an alkali metal alkoxide include, for example, ethyllithium, propyllithium, n-butyllithium, sec-butyllithium, t-butyllithium and t-butyllithium.
-Butyllithium, hexyllithium, phenyllithium or mixtures thereof. Of these, n-butyllithium and sec-butyllithium are preferred.

The molar ratio of the alcohol compound to the organolithium compound (the former to the latter) needs to be 1: 0.7 to 5.0, preferably in the range of 0.8 to 2.0. , More preferably 0.9 to 1.2. When the molar ratio of the organolithium compound exceeds 5.0, it is difficult to obtain the effects of improving the breaking strength, abrasion resistance and low hysteresis. On the other hand, when the molar ratio of the organolithium compound is less than 0.8, the polymerization rate is remarkably reduced, and the productivity is easily reduced. The denaturation efficiency at the time of carrying out is reduced.

(A1) and / or (a2) of the present invention
A vinyl compound or a conjugated diolefin compound having a functional group having a structure of (a1) and / or a secondary amine compound having a structure of (a2) or a functional compound having a structure of (a1) and / or (a2) When an initiator consisting of a reaction product of a specific tertiary amine compound and an organolithium compound is prepared in a separate pot from the polymerization vessel, 1,
It is preferable to add a conjugated diolefin compound such as 3-butadiene or isoprene in an amount of 1 to 100 times, preferably 1 to 50 times, the mole of the initiator component, since the polymerization reaction starts promptly.

Further, the Mooney viscosity (ML1 + 4,100) of the conjugated diolefin-based (co) polymer obtained in the present invention.
C) is preferably in the range of 20 to 200. 20
If it is less than 200, the breaking strength, abrasion resistance and low hysteresis loss deteriorate, and if it exceeds 200, the workability tends to decrease. The Mooney viscosity (ML1 + 4, 100 ° C.) is 1
Although the polymer exceeding 00 is inferior in processability as it is, it is not preferable. However, the addition of a extender oil such as an aromatic process oil or a naphthene process oil or a liquid polymer having an average molecular weight of 150,000 or less increases the Mooney viscosity. It can be reduced to 100 or less so that it can be used without any problem in processing. However, when an aromatic process oil is added to a polymer modified or coupled with the tin compound as the component (k), the tin-carbon bond is easily cleaved, so that the following formula VGC = (G −0.24-0.022 log (V-3
5.5)) / 0.755 where G: specific gravity (60/60 ° F) V: Saybolt universal viscosity (sus), 210 °
The viscosity specific gravity constant (VGC) represented by F is 0.800 to 0.8.
Preferably, an extender oil of 950 is blended.

The polymerization reaction solution containing the conjugated diolefin-based copolymer provided by the present invention may be added to a solution used in a usual solution polymerization method, for example, after adding a stabilizer or the like in a solution state, Extender oils such as aromatic process oils and naphthene process oils and liquid polymers having an average molecular weight of 150,000 or less (or a solution of the liquid polymer)
And the rubber and the solvent are separated and washed by a direct drying method or a steam stripping method, and dried by a vacuum drier, a hot air drier, a roll, or the like to obtain the desired conjugated diolefin-based copolymer. Can be released.

The conjugated diolefin-based copolymer of the present invention comprises
Blend alone or with natural rubber, polyisoprene rubber, polybutadiene rubber, emulsion-polymerized styrene-butadiene rubber, etc., and kneaded with a reinforcing agent such as carbon black or silica and various compounding agents with a roll or Banbury mixer, and then sulfur, By adding a sulfur accelerator, it can be used for tire rubber such as treads, sidewalls, carcass, belts, anti-vibration rubber and other industrial products.

When the conjugated diolefin copolymer of the present invention is used for a tire, particularly a tire tread, the reinforcing material to be filled includes carbon black, granular silica and the like. In particular, when the vulcanized product is effectively reinforced and good wear resistance and breaking strength are expected, carbon black is preferably used. The filling amount is the total rubber component 1
20 to 100 parts by weight with respect to 00 parts by weight. In particular, for use in fuel-efficient tires, the use of granular silica is preferred for the purpose of lowering the hysteresis loss of the vulcanizate to provide good rolling resistance and improving wet skid resistance. The filling amount of this granular silica is 20 to 12 parts by weight based on 100 parts by weight of all rubber components.
0 parts by weight.

When silica is used as a filler, various known silane coupling agents can be used for the purpose of enhancing the reinforcing effect. The silane coupling agent is a component capable of reacting with a silica surface such as an alkoxysilyl group in a molecule and a component capable of reacting with a rubber, particularly a carbon-carbon double bond, such as a polysulfide, a mercapto group, or an epoxy group. Refers to a compound having For example, bis- (3-triethoxysilylpropyl) tetrasulfide is well known as a silane coupling agent. Further, by using a combination of carbon black and granular silica in the range of 20 to 120 parts by weight with respect to 100 parts by weight of the total rubber component, good abrasion, excellent breaking strength and excellent low hysteresis performance, It is also possible to balance wet grip performance.

[0064]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, which do not limit the scope of the present invention. Various measurements in the examples were performed according to the following methods. It was determined by a microstructure infrared absorption spectrum method (Morello method). A calibration curve was prepared and determined by the infrared absorption spectrum method of the bound styrene content . Single-chain aromatic vinyl compound unit (unit in which aromatic vinyl compound is connected alone) and long-chain aromatic vinyl compound unit (unit in which eight or more aromatic vinyl compounds are connected) Ozonolysis-gel developed by Tanaka et al. Measured by permeation chromatography (Polyme
r, Vol. 22, P. 1721-1723, 1981.). Weight average molecular weight gel permeation chromatography (GPC)
(Water Company, Model 244), in terms of polystyrene. Mooney Viscosity According to JIS K6300, it was measured at an L rotor, preheating for 1 minute, rotor operation time for 4 minutes, and a temperature of 100 ° C.

Evaluation of Physical Properties of Vulcanizate
After kneading with a cc Labo Plastomill, various measurements were performed using a vulcanized product that had been vulcanized at 145 ° C. for a predetermined time. Tensile strength was measured according to JIS K6301. tan δ (50 ° C.), tan δ (0 ° C.) Measurement was performed using a dynamic spectrometer manufactured by Rheometrics, USA, under the conditions of a tensile dynamic strain of 1%, a frequency of 10 Hz and a temperature of 50 ° C. Indicated by an index, the larger the numerical value, the smaller and better the rolling resistance. Also, tan δ (0 ° C.)
Uses the same equipment, tensile dynamic strain 0.1%, frequency 10H
z, measured at 0 ° C. Expressed as an index, the larger the numerical value, the greater and better the wet skid resistance.

Lambourn abrasion index Using a Lambourn abrasion tester, the slip rate was represented by the amount of abrasion at 25%, and the measurement temperature was room temperature. The higher the index, the better the wear resistance. The unity and gloss appearance of the dump rubber after processability kneading were visually inspected and evaluated.

Example 1 (Polymer A) 20 g of cyclohexane, 5 g of tetrahydrofuran were placed in a pressure-resistant bottle having an inner volume of 100 ml which had been sufficiently substituted with nitrogen.
Di-n-butylamine as a secondary amine 4.84 mm
ol is added and stoppered, then n-butyl lithium
4.84 mmol was added and reacted at 50 ° C. for 15 minutes. Thereafter, 1.39 g of 1,3-butadiene (25.8 m
mol) was added, and the mixture was further reacted for 15 minutes.

Into a 20 liter autoclave reaction vessel equipped with a stirrer and jacket, which has been fully substituted with nitrogen, 1,2-butadiene 10
20 g / mi of 1,3-butadiene containing 0 ppm
n, styrene 10 g / min, cyclohexane 150 g / min as solvent and tetrahydrofuran 1.
07 g / min. And a reaction product of the above prepared pyrrolidine and n-butyllithium as a catalyst were continuously charged at 0.011 g / min. In terms of n-butyllithium as a raw material, and the temperature of the reactor was controlled at 70 ° C. did. At the top outlet of the first reactor, methyltriphenoxysilane was continuously added at a rate of 0.058 g / min., And this was introduced into the second reactor connected to the reactor to carry out a denaturation reaction. . Table 1 summarizes the conditions of the polymerization reaction and the modification reaction. At the outlet of the second reactor, 0.7 parts by weight of di-tert-butyl-p-cresol was added to 100 parts by weight of rubber. 37.5 parts by weight of a highly aromatic oil was added to 100 parts by weight of the rubber to the polymer solution after the reaction, the solvent was removed by steam stripping, and the rubber was dried with a hot roll at 115 ° C. Table 3 shows the analysis results. The polymerization conversion rate is 3%
At this time, a part of the polymer solution was withdrawn, and the polymer was isolated and analyzed by ¹ H-NMR.
It was confirmed that an amino group was introduced into 8%.

Example 2 (Polymer B) Di-n-butylamine (4.84 mmol) as a secondary amine
4.8 instead of pyrrolidine (tetramethylene imine)
Except for using 4 mmol, a polymer was obtained with the same formulation as Polymer A. The reaction conditions are shown in Table 1, and the analytical values of the obtained polymer are shown in Table 3.

Example 3 (Polymer C) Di-n-butylamine as an amine compound 4.84 mm
A polymer was obtained in the same manner as in Polymer A, except that 4.84 mmol of vinylbenzyldimethylamine, a vinyl compound having a tertiary amino group, was used instead of ol. The reaction conditions are shown in Table 1, and the analysis values of the obtained polymer are shown in Table 3.

Example 4 (Polymer D) A fully nitrogen-substituted autoclave reactor equipped with a stirrer and jacket and having a volume of 20 liters containing 1,3-butadiene containing 100 ppm of 1,2-butadiene as a monomer was prepared. Butadiene: 20 g / min., Styrene: 10 g / min., Cyclohexane: 15 g
0 g / min., 1.07 g / mi of tetrahydrofuran
n. As a catalyst, 0.011 g / min. of pyrrolidine and 0.011 g / min. of n-butyllithium were continuously charged, and the temperature of the reactor was controlled at 70 ° C.

At the top outlet of the first reactor, methyltriphenoxysilane was continuously added at a rate of 0.058 g / min., And this was introduced into the second reactor connected to the above reactor to perform coupling. The reaction was performed. The reaction conditions are shown in Table 1. The reaction conditions are shown in Table 1. At the outlet of the second reactor, 0.7 parts by weight of di-tert-butyl-p-cresol was added to 100 parts by weight of rubber. A highly aromatic oil was added to the polymer solution after the reaction in an amount of 37.5 parts by weight based on 100 parts by weight of the rubber, the solvent was removed by steam stripping, and the rubber was dried with a hot roll at 115 ° C. The analytical values of the obtained polymer are shown in Table 3.

Example 5 (Polymer E) N, N-dimethyl-o-, a tertiary amine compound, was changed to 0.011 g / min of pyrrolidine as the amine compound.
A polymer was obtained according to the same formulation as Polymer D except that toluidine was used in an amount of 0.021 g / min. Table 1 shows the reaction conditions.
Table 3 shows the analytical values of the obtained polymer.

Examples 6 to 16 (Polymers FP) Charge composition of monomers, charge amounts of tetrahydrofuran, pyrrolidine, n-butyllithium, and type and amount of modifier added at the top outlet of the first reactor Was changed as described in Table 1, and a polymer was obtained in the same manner as in Polymer D. However, for Polymers J and K, the solvent was removed without adding a high aromatic extender oil, and the polymer was dried. The analytical values of the obtained polymer are shown in Table 3.

Comparative Example 1 (Polymer Q) The addition amount of 1,3-butadiene was 22.5 g / min., The addition amount of styrene was 7.5 g / min., And the addition amount of tetrahydrofuran was 3.85 g / min. Except for the change, polymerization was carried out in the first reactor in the same manner as in Polymer D. In the second reactor, 1,3-butadiene was further added as a monomer at 11.3 g / min. 8 g / min., 0.006 pyrrolidine as a catalyst
g / min. and 0.006 g / mi of n-butyllithium.
n. was continuously charged and polymerization was carried out at 70 ° C.

At the top outlet of the second reactor, methyltriphenoxysilane was continuously added at 0.088 g / min., And this was introduced into the third reactor connected to the second reactor. To perform a coupling reaction.
The reaction conditions are shown in Table 1. The subsequent treatment was performed in the same manner as in the case of the polymer D to obtain a polymer. The analytical values of the obtained polymer are shown in Table 3.

Comparative Examples 2 and 3 (Polymer R, S) The polymerization and modification reactions were carried out in the same manner as in Polymer D except that the amount of pyrrolidine, one component of the catalyst, was changed as shown in Table 1. A polymer was obtained. The analytical values of the obtained polymer are shown in Table 3.

Comparative Example 4 (Polymer T) In a 5-liter autoclave reaction vessel replaced with nitrogen, 2,500 g of cyclohexane, 25.0 g of tetrahydrofuran, 100 g of styrene, 400 g of 1,3-butadiene and 0.19 g of pyrrolidine were added. Was charged. After adjusting the temperature of the contents of the reaction vessel to 10 ° C., 0.19 g of n-butyllithium was added to initiate polymerization. The polymerization was carried out under adiabatic conditions and the maximum polymerization temperature reached 85 ° C. After the polymerization conversion reached 100%, 2.97 mmol of methyltriphenoxysilane was added to carry out a modification reaction for 15 minutes. 2,6-Di-tert-butyl-p-cresol was added to the polymer solution after the reaction, and 187.5 g of a highly aromatic oil (37.5 parts by weight per 100 parts by weight of rubber) was further added. The solvent was removed by steam stripping, and the rubber was dried with a hot roll at 115 ° C. The reaction conditions are shown in Table 2, and the analytical values of the obtained polymer are shown in Table 3.

Example 17 (Polymer U) Cyclohexane (2,500 g), tetrahydrofuran (47.5 g), and pyrrolidine (0.19 g) were charged into a nitrogen-substituted autoclave reaction vessel having a volume of 5 liters, and the temperature of the contents of the reaction vessel was lowered. The temperature was adjusted to 60 ° C. After adding 0.19 g of n-butyllithium, 1.11 g of styrene /
The polymerization was carried out by continuously charging 4.33 g / min of 1,3-butadiene for 90 minutes. During the polymerization, the temperature of the reaction system was controlled to be 60 ° C. After the completion of charging of the monomer, the polymerization conversion reaches 100%, and then 2.97 mmol of methyltriphenoxysilane is obtained.
Was added and reacted for 15 minutes. 2,6-Di-t-butyl-p-cresol was added to the polymer solution after the reaction, and 187.5 g of a highly aromatic oil (rubber 100
(37.5 parts by weight with respect to the weight unit), the solvent was removed by steam stripping, and the rubber was dried with a hot roll at 115 ° C. The reaction conditions are shown in Table 2, and the analytical values of the obtained polymer are shown in Table 3.

Comparative Example 5 (Polymer V) Polymerization reaction / modification was carried out in the same formulation as Polymer T, except that in the formulation of Polymer T, the charge amount of the monomer, tetrahydrofuran, and the polymerization temperature were changed as shown in Table 2. The reaction was performed to obtain a polymer. The analytical values of the obtained polymer are shown in Table 3.

Comparative Example 6 (Polymer W) Polymerization was carried out in the same manner as in Polymer U, except that 0.19 g of pyrrolidine was not added. The reaction conditions are shown in Table 2, and the analytical values of the obtained polymer are shown in Table 3.

Comparative Example 7 (Polymer X) In the formulation of Polymer T, polymerization was carried out without adding 0.19 g of pyrrolidine, and the modification reaction after polymerization was changed to 2.97 mmol of methyltriphenoxysilane to obtain N,
N, N ', N'-tetraethylaminobenzophenone 2.
A polymer was obtained with the same formulation as for polymer T, except that the run was 97 mmol. The reaction conditions are shown in Table 2, and the analytical values of the obtained polymer are shown in Table 3.

[0083]

[Table 1]

[0084]

[Table 2]

[0085]

[Table 3]

Evaluation of Physical Properties of Rubber Compositions Examples 18 to 27 and Comparative Examples 8 to 11 (Blended with carbon black) The styrene-butadiene copolymer experimentally produced as described above was mixed with the "blended with carbon black" shown in Table 4A. A vulcanized product was prepared under the following conditions, and physical properties were evaluated. Tensile strength, tan δ (0 ° C.), tan δ (5
0 ° C.), and the physical property value of Lambourn abrasion is represented by an index when the value in the case of using Comparative Example 2 (Polymer R) is set to 100, and the larger the numerical value of each physical property, the better. Table 5 shows the polymers used for the evaluation and the physical property evaluation results.

Examples 28 to 36 and Comparative Examples 12 to 16 (containing silica) The styrene-butadiene copolymer was prepared as shown in Table 4.
A vulcanizate was prepared under the conditions of “silica compounding” shown in B of Table B, and physical properties were evaluated. Tensile strength, tan δ (0 ° C), tan
δ (50 ° C.) and physical properties of Lambourn abrasion are shown in Comparative Example 2.
It is represented by an index with the value in the case of using (Polymer R) being 100, and the larger the value of each physical property, the better. Table 6 shows the polymers used for the evaluation and the physical property evaluation results.

Examples 37 to 46 and Comparative Examples 17 to 23 (combination of carbon black / silica) The styrene-butadiene copolymer produced as described above was mixed with a mixture of carbon black / silica shown in the composition C of Table 4. Under the above conditions, and the physical properties were evaluated. Tensile strength, t
An δ (0 ° C.), tan δ (50 ° C.), and physical properties of Lambourn abrasion are represented by indices with the value in the case of using Comparative Example 2 (Polymer R) being 100, and the larger the number, the better. It is. Table 7 shows the polymers used for the evaluation and the physical property evaluation results.

[0089]

[Table 4]

[0090]

[Table 5]

[0091]

[Table 6]

[0092]

[Table 7]

Tables 5 to 7 show the following. According to the evaluation results of the carbon black compound shown in Table 5, the diolefin copolymer having an amino group introduced at the polymer terminal and having a specific aromatic vinyl compound chain structure and a specific GPC molecular weight distribution according to the present invention is a Good processability of the polymer of
Low hysteresis loss (tan δ, 50 ° C.) and wet skid characteristics (t) without impairing wear resistance and fracture characteristics
(an δ, 0 ° C.). FIG. 1 shows the low hysteresis loss property (tan δ, 50 ° C.) and the wet skid property (t) of the polymer of the present invention.
(an δ, 0 ° C.).

Further, the active terminal of the polymer polymerized with the initiator of the present invention is modified with an isocyanate compound, a tin compound, an ester compound, a ketone compound, an amide compound, a pyridyl-substituted ketone compound or the like to form a molecular chain. It can be seen that the effect of improving various physical properties is remarkable by efficiently introducing a functional group into both ends of the compound. Comparative Examples 10 and 11 are polymers having a bimodal molecular weight distribution in which an amino group is introduced at a polymerization terminal, but have poor extrusion processability, and have high breaking strength.
It can be seen that the balance between the wet skid characteristics (tan δ, 0 ° C.) and the low hysteresis performance (tan δ, 50 ° C.) is also deteriorated. Comparative Example 11 is out of the range of the present invention in the chain structure of the aromatic vinyl compound, and is particularly inferior in balance between wet skid characteristics (tan δ, 0 ° C.) and low hysteresis performance (tan δ, 50 ° C.).

From the results of the evaluation by the combination of silica shown in Table 6 and the evaluation of the combination of silica and carbon black shown in Table 7, the effect of the polymer of the present invention was improved in all the formulations in comparison with the conventional polymer. It can be seen that FIG.
3 and FIG. 3 clearly show that the polymer of the present invention has an excellent balance between hysteresis loss properties (tan δ, 50 ° C.) and wet skid properties (tan δ, 0 ° C.) even when silica is mixed or silica / carbon black is used in combination. Is what you do.

[0096]

According to the present invention, there is provided a diolefin copolymer having an amino group introduced at the terminal of the polymer, having a specific bond unit of an aromatic vinyl compound and a specific GPC molecular weight distribution. You. By using such a diolefin-based copolymer, it has good workability and does not impair abrasion resistance in any combination of carbon black, silica and carbon black / silica. The low hysteresis loss property, wet skid property, and breaking property are simultaneously improved, and particularly, it can be suitably used for tread rubber such as high-performance tires, fuel-efficient tires, and all-season tires.

[Brief description of the drawings]

FIG. 1 shows the balance between hysteresis loss property (tan δ, 50 ° C.) and wet skid characteristics (tan δ, 0 ° C.) in the carbon black formulation shown in Table 5.

FIG. 2 shows hysteresis loss properties (tan δ, 50 ° C.) and wet skid properties (tan) of the silica compound shown in Table 6.
δ, 0 ° C.).

FIG. 3 shows the balance between hysteresis loss property (tan δ, 50 ° C.) and wet skid properties (tan δ, 0 ° C.) in the combination of carbon black and silica shown in Table 7. It is to be noted that the larger the numerical value, the better, and the upper right direction in the figure has a good balance between the two.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Hiroshi Akuma F-term (reference) 4J002 BC101 BL001 DA036 DJ016 FD016 GN01 4J100 AB02P AB03P AB04P AB07P AB16P AQ12P AS01Q AS02Q AS03Q AS07Q BA04P BA11H BA12H BA15H BA31P BA35H BA42H BA50H BA71H BA77H BC43H BC66H BC69H BD04H CA04 CA31 DA04 FA02 FA03 FA17 HA61 HC25 HC33 HC34 HC50 HC51 HC63 HC77 HC78 HC85

Claims (3)

[Claims] 1. A polymer obtained by copolymerizing (1) a conjugated diolefin and an aromatic vinyl compound, wherein (2)
At least 70% of all polymer chains have an amino group at the polymerization initiation end of the polymer chain, (3) the amount of the bound aromatic vinyl compound is 5 to 55% by weight, and (4) the aromatic vinyl compound. Is a single-chain aromatic vinyl compound unit which is singly linked, is 50% by weight or more based on the bound aromatic vinyl compound, and (5) a long-chain aromatic vinyl compound wherein eight or more bonded aromatic vinyl compounds are linked. The units are less than 10% based on the linked aromatic vinyl compound, and (6) the molecular weight distribution is monomodal, and the weight average molecular weight (Mw) to number average molecular weight (Mn) ratio Mw / Mn is 1.3. Above, 3.
A conjugated diolefin-based copolymer rubber, which is less than 0. 2. The polymerization-terminated end of at least 40% of the polymer chains in all polymer chains has the following (a), (b), (c),
(D), (e), (f) and (g) compounds; (a) isocyanate compound and / or isothiocyanate compound, (b) amide compound and / or imide compound, (c) pyridyl substitution Ketone compounds and / or
Or a pyridyl-substituted vinyl compound, (d) a silicon compound, (e) an ester compound, (f) a ketone compound,
The conjugated diolefin-based copolymer rubber according to claim 1, wherein the conjugated diolefin-based copolymer rubber is modified or coupled with at least one compound selected from the group consisting of (g) a tin compound. 3. 100 parts by weight of a total rubber component containing the copolymer rubber of claim 1 or 2 and carbon black 20 to 1
A rubber composition comprising 00 parts by weight, 20 to 120 parts by weight of silica, and a filler selected from the group consisting of carbon black and 20 to 120 parts by weight of silica.