JPH11246633A - Conjugated diolefin-based copolymer rubber and its composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a conjugated diolefin-based copolymer rubber having good processability even in any blends of a carbon black blend and a silica blend, having simultaneously improved abrasion resistance, fracture characteristics, low hysteresis loss and wet skid characteristics, and usable as a material, for a tire thread for a low fuel consumption tire, a large tire and a high quality tire. SOLUTION: This conjugated diolefin-based copolymer rubber is a copolymer of a conjugated diolefin and an aromatic vinyl compound, has 0.0025-0.20 mmol/ g-copolymer rubber of the content of an amino group binding to the rubber, 5-30 wt.% of the content of a polymerization unit of an aromatic vinyl compound, >=55 mol.% of the content of a vinyl-bond (the content of 1,2-bond and 3,4-bond) in the polymerization units of the conjugated diolefin part or 30-50 wt.% of the content of the polymerization unit of the aromatic vinyl compound, and 25-55 mol.% of the content of the vinyl bond in the polymerization unit at the conjugated diolefin part, and has a polymodal type molecular weight distribution measured by a GPC.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a conjugated diolefin copolymer rubber. More specifically, the present invention relates to a conjugated diolefin-based copolymer rubber capable of providing an automobile tire tread having good workability and a balance of wear resistance, fracture characteristics, low hysteresis loss and wet skid characteristics.

[0002]

2. Description of the Related Art In response to recent demands for lower fuel consumption of automobiles, rubber materials for tires have low rolling resistance, excellent wear resistance, excellent breaking characteristics, and also have steering stability represented by wet skid resistance. A conjugated diolefin rubber is desired.

In order to reduce the rolling resistance of a tire,
Hysteresis loss of the vulcanized rubber may be reduced, and as an evaluation index of the vulcanized rubber, the rebound resilience at 50 to 80 ° C.,
A tan δ of up to 80 ° C., good-rich heat generation and the like are used. Large rebound resilience at 50-80 ° C or 50-80 ° C
A rubber material having a small tan δ or good rich heat generation is preferable. As rubber materials having a small hysteresis loss, natural rubber, polyisoprene rubber, polybutadiene rubber and the like are known, but these have a problem that wet skid resistance is low.

As a method of reducing hysteresis loss without impairing wet skid resistance, a functional group is introduced into a polymer terminal of a styrene-butadiene copolymer having various structures polymerized with an organolithium initiator in a hydrocarbon solvent. A way to do that has been proposed. Styrene butadiene copolymer obtained by modifying or coupling a polymer terminal with a tin compound (see JP-A-57-55912), styrene-butadiene copolymer having a polymer terminal modified with an isocyanate compound or the like (Japanese Patent Application Laid-Open No.
No. 141741). These modified polymers exhibited an effect of reducing hysteresis loss without impairing wet skid resistance, particularly in a composition containing carbon black as a reinforcing agent, and further exhibiting excellent abrasion resistance and fracture characteristics.

On the other hand, recently, as a rubber material for tires, there has been proposed a method of using a rubber composition in which silica or a mixture of silica and carbon black is blended as a reinforcing agent. Tire treads containing silica or a mixture of silica and carbon black have low rolling resistance and good steering stability typified by wet skid resistance,
On the other hand, there is a problem that the vulcanizate has low tensile strength and abrasion resistance. The above-mentioned modified styrene-butadiene copolymer is a rubber material for tires having excellent abrasion resistance and fracture characteristics in a composition using carbon black as a reinforcing agent, but it is not suitable in a composition using silica as a reinforcing agent. The improvement effect is small.

For the purpose of improving the tensile strength and abrasion resistance of a vulcanizate containing silica or a mixture of silica and carbon black, a rubber composition containing a polymer having a functional group compatible with silica has been proposed. Have been. Tokiko 4
JP-A-9-36957 proposes a method for producing a polymer by reacting silicon tetrahalide, trihalosilane or the like. Japanese Patent Publication No. 52-5071 discloses a method for producing a polymer modified with a halogenated silane compound. Furthermore, Japanese Patent Laid-Open No. 1-188
No. 501 discloses an alkylsilyl group and JP-A-5-230.
No. 286 discloses a diene rubber into which a halogenated silyl group is introduced.

Although the use of these modified polymers in a composition containing silica or a mixture of silica and carbon black can improve the physical properties to some extent,
The tensile strength and abrasion resistance of the vulcanized product have not yet been sufficiently improved, and the hysteresis loss has not been sufficiently reduced particularly with the increase in the ratio of carbon black when a mixture of silica and carbon black is blended. Further, in general, there has been a problem that the silica-containing composition is inferior in processability to the carbon black-containing composition, so that the processing cost is high. 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.

[0008] The conventionally known modified polymers are mainly classified into those suitable for compounding with carbon black and those suitable for compounding with silica. It was necessary to reselect the rubber to be used. Further, when a mixture of silica and carbon black is blended, the effect of any of the modified polymers increases or decreases in correlation with the mixing ratio of silica and carbon black.

[0009] As an effective modified polymer in both carbon black and silica blends, a polymer into which an amino group is introduced is considered. Regarding the compounding of carbon black, (1) a polymer having an amino group introduced into a polymerization terminal by using a lithium amide initiator (JP-A-59-38)
No. 209, Japanese Patent Publication No. 5-1298, JP-A-6-2795
No. 15, JP-A-6-199923 and JP-A-7-5-5
(2) styrene-butadiene copolymers of various structures polymerized with an organolithium initiator with urea compounds (see JP-A-61-27338) and dialkylaminobenzophenones Compounds (JP-A-58-162604 and JP-A-58-162604)
No. 189203), lactam compounds (Japanese Unexamined Patent Publication No.
Polymers obtained by modification with a nitrogen-containing compound (see, for example, JP-A-1-43402) have been proposed. Further, as a polymer for blending silica, JP-A-1-101344, JP-A-64-22940 and JP-A-9-7168.
No. 7 proposes a diene rubber having an amino group introduced therein.

The polymers obtained by these methods have achieved various improvements in physical properties to some extent in the respective formulations of carbon black and silica. However, the above-mentioned literature mainly describes a method for introducing an amino group into a polymer in detail, and does not mention the relationship between the structure of the polymer itself and each performance beyond general matters.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to provide a conjugated diolefin copolymer rubber having a novel combination of composition and properties. Another object of the present invention is to have a specific content of polymerized units of an aromatic vinyl compound having an amino group in the polymer chain, a specific vinyl bond content in a polymerized unit of a specific conjugated diolefin moiety, and An object of the present invention is to provide a conjugated diolefin-based copolymer rubber having a specific GPC molecular weight distribution.

Still another object of the present invention is to provide good workability in any combination of carbon black and silica, low hysteresis loss and wet skid characteristics without impairing abrasion resistance and fracture characteristics. As a tread material for fuel-efficient tires, large tires and high-performance tires, which have improved hysteresis loss, abrasion resistance and fracture characteristics at the same time without any improvement or impairing wet skid properties. An object of the present invention is to provide a conjugated diolefin copolymer rubber which can be used. Still other objects and advantages of the present invention will become apparent from the following description.

According to the present invention, the above objects and advantages of the present invention are attained in a copolymer rubber of a conjugated diolefin and an aromatic vinyl compound, wherein (1) the amino group content (nitrogen content) bonded to the copolymer rubber; Amount) 0.0025-0.20 mmol
/ G · copolymer rubber polymer, wherein (2) the content of polymerized units of the aromatic vinyl compound is 5% by weight or more and less than 30% by weight based on the copolymer rubber, and (3) polymerization of conjugated diolefin The vinyl bond content (content of 1,2 bond and 3,4 bond) in the unit is 55 mol% or more based on the polymerized unit of the conjugated diolefin, and (4) the molecular weight distribution is polymodal. A copolymer rubber (hereinafter sometimes referred to as the first copolymer rubber of the present invention) or a copolymer rubber of a conjugated diolefin and an aromatic vinyl compound, wherein (1) the rubber is bonded to the rubber. Amino group content (nitrogen content) is 0.0025 to 0.20 mmol
1 / g · copolymer rubber polymer, wherein (2) the content of the polymerized unit of the aromatic vinyl compound is 3 based on the copolymer rubber.
0 to 50% by weight, and (3) the vinyl bond content (1,2 bond and 3,3) in the polymerized unit of the conjugated diolefin.
(4 bond content) based on the polymerization unit of the conjugated diolefin is 25 to 55 mol%, and (4) the molecular weight distribution is a polymodal type. This may be referred to as a second copolymer rubber).

Hereinafter, the present invention will be described in detail. The copolymer rubber of the present invention (an outline including the first copolymer rubber and the second copolymer rubber, and hereinafter the same unless otherwise specified) is a copolymer obtained by copolymerizing a conjugated diolefin and an aromatic vinyl compound. One of the features is that it is a coalescence and has an amino group.

The content of amino groups bonded to the copolymer rubber is 0.0025 to 0.20 mmol / g · copolymer rubber polymer. The content is preferably from 0.0030 to
0.10 mmol / g · copolymer rubber polymer, more preferably 0.0030 to 0.05 mmol / g · copolymer rubber polymer.

The amino group has a polymerization start terminal, a polymerization end terminal,
It may be bonded to any of the polymer main chain and side chain, but is introduced at the polymerization start terminal or the polymerization end terminal since the energy loss from the polymer terminal can be suppressed and the hysteresis loss property can be improved. Is preferred.

When the number of amino groups bonded to the polymer chain exceeds 0.20 mmol / g · copolymer rubber polymer, the interaction with a reinforcing agent such as carbon black or silica becomes too high, and the compounding viscosity is reduced. Improves the workability. Further, the number of amino groups is 0.0025 mmol / g.
If the amount is less than the copolymer rubber polymer, the effect of introducing an amino group will not be exhibited.

The amino group introduced into the polymer chain of the polymer of the present invention includes, for example, the following formulas (a1) and (a)
2):

Embedded image (Wherein, R ¹ represents hydrogen (—H), an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms;
² is an alkyl group having 1 to 20 carbon atoms or 6 to 20 carbon atoms
Represents an aryl group. )

[0019]

Embedded image (Wherein, R ³ and R ⁴ are the same or different and each have 1 carbon atom)
Indicates to 3 alkylene group, X is -CH ₂ -, - it indicates O- and -NH- from group selected, R ⁵ is hydrogen (-
H) or an alkyl group having 1 to 5 carbon atoms;
Represents an integer of 1 to 4. )).

The structures represented by the above formulas (a1) and (a2) include, for example, dimethylamino, diethylamino, dipropylamino, di-n-butylamino,
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, ethylhexylamino group, trimethyleneimino group, tetramethyleneimino group, 2-methyltetramethyleneimino group, 3-methyltetramethyleneimino group, pentamethyleneimino group, 2
-Methylpentamethyleneimino group, 3-methylpentamethyleneimino group, 4-methylpentamethyleneimino group,
Examples thereof include a 3,5-dimethylpentamethyleneimino group, a 2-ethylpentamethyleneimino group, a hexamethyleneimino group, a heptamethyleneimino group, and a dodecamethyleneimino group. The introduction rate of these functional groups is 0.
If the amount is less than 0025 mmol / g · copolymer rubber polymer%, the resulting copolymer rubber does not sufficiently improve hysteresis loss characteristics, abrasion resistance, and fracture characteristics, which is not preferable.

The method of introducing a functional group having the structure of (a1) and / or (a2) into the terminal of the polymer of the present invention is not particularly limited, and for example, the following method can be adopted. Method (1), after reacting an organic monolithium compound with a vinyl compound or a conjugated diolefin compound having a functional group of the structure (a1) and / or (a2) in a hydrocarbon solvent, A method of copolymerizing with 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, Examples thereof include 2-vinyl-5-ethylpyridine and 4-vinylbenzyldimethylaminoethyl ether.

Method (2), (a1) and / or (a)
Conjugated diolefins and aromatics using a reaction product of a secondary amine compound having the structure of 2) and an organic alkali metal compound or an alkali metal amide compound having the structure of (a1) and / or (a2) as a polymerization initiator A method of copolymerizing with a vinyl compound.

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-
(2-ethylhexyl) amine, dicyclohexylamine, N-methylbenzylamine, diallylamine and the like can be mentioned. Examples of the secondary amine compound having the structure (a2) include morpholine, piperazine,
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- Dimethylpyrrolidine, azetidine, hexamethyleneimine, heptamethyleneimine, 5-benzyloxyindole, 3
-Azaspiro [5,5] undecane, 3-azabicyclo [3.2.2] nonane, carbazole and the like.
The alkali metal amide compound having the structure of (a1) and / or (a2) is obtained by converting the hydrogen atom (H) of the secondary amine compound having the structure of (a1) and / or (a2) to an alkali metal (Li, Na, K, Rb or S
It is a compound substituted by c).

Method (3), (a1) and / or (a)
Conjugated diolefins and aromatics using a reaction product of a tertiary amine compound having the structure of 2) and an organic alkali metal compound or an organic alkali metal compound having a structure of (a1) and / or (a2) as a polymerization initiator A method of copolymerizing with a vinyl compound.

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, benzyldimethylamine, benzyldiethylamine, benzyldipropylamine, benzyldibutylamine, (o-methylbenzyl) dimethylamine, (m-methylbenzyl) dimethyl Amines and (p-methylbenzyl) dimethylamine.

Examples of the tertiary amine compound having the structure (a2) include, for example, N, N-tetramethylene-o-
Toluidine, N, N-heptamethylene-o-toluidine, N, N-hexamethylene-o-toluidine, N, N-
Trimethylenebenzylamine, N, N-tetramethylenebenzylamine, N, N-hexamethylenebenzylamine, N, N-tetramethylene (o-methylbenzyl) amine, N, N-tetramethylene (p-methylbenzyl)
Amines, N, N-hexamethylene (o-methylbenzyl) amine, N, N-hexamethylene (p-methylbenzyl) amine and the like.

The organic alkali metal compound having the structure of (a1) and / or (a2) is obtained by converting the active hydrogen atom (H) of the tertiary amine compound having the structure of (a1) and / or (a2) to an alkali. Metals (Li, Na, K,
Rb or 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, and preferably n-butyllithium, sec-butyllithium.
-Butyl lithium is used.

The reaction between the secondary amine compound or the tertiary amine compound and the organic alkali metal compound is carried out by the secondary
It is necessary to carry out the reaction in a molar ratio of the amino group (NH) in the structure of the tertiary amine compound or the active hydrogen in the structure of the tertiary amine compound to the organic alkali metal compound of 1: 0.2 to 5.0. Yes, preferably 1: 0.5-2.0, more preferably 1: 0.8-1.2. 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. And 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 when the polymer terminal is modified with a functional group is reduced. I do. In addition, the reaction between the secondary amine compound or the tertiary amine compound and the organic alkali metal compound is performed in a reaction pot separate from the polymerization vessel prior to the polymerization, and the polymerization vessel is charged. Good.

The reaction between the secondary amine compound or the tertiary amine compound and the organic alkali metal compound basically proceeds instantaneously, but an aging 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,
There is no problem if used after storage for about 10 days to 2 weeks.
Further, the reaction between the secondary amine compound or the tertiary amine compound and the organic alkali metal compound is desirably performed in a temperature range of 0 to 120 ° C. In addition, a secondary amine compound or a tertiary amine compound is reacted with an organic alkali metal compound in the presence of a monomer of a conjugated diolefin and a monomer of an aromatic vinyl compound in a polymerization vessel,
A mode in which polymerization is performed subsequently 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 rubber of the present invention is a polymer obtained by copolymerizing a conjugated diolefin and an aromatic vinyl compound, and has an amino group as described above. . 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 are preferably used.

Examples of the aromatic vinyl compound include styrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, α-methylstyrene, 2,4
-Dimethylstyrene, 2,4-diisopropylstyrene, 4-tert-butylstyrene, divinylbenzene, tert-butoxystyrene and mixtures thereof. Of these, styrene is particularly preferred.

In the first copolymer rubber of the present invention, the content of the bound aromatic vinyl compound bonded in the polymer chain, that is, the content of the polymerized unit of the aromatic vinyl compound is determined based on the copolymer rubber. 5% by weight or more and less than 30% by weight, preferably 10% by weight or more and less than 27% by weight. If the content of the bound aromatic vinyl compound is less than 5% by weight, the wet skid properties, abrasion resistance and breakage properties deteriorate. If the content is 30% by weight or more, the balance between hysteresis loss and wet skid characteristics deteriorates.

In the polymerization unit of the conjugated diolefin,
In the first copolymer rubber of the present invention, the content of 2-bonds and / or 3,4-bonds (hereinafter, referred to as vinyl bonds) is preferably at least 55 mol%, based on the polymerization units of the conjugated diolefin. Is at least 57 mol%, more preferably at least 59 mol%. If the vinyl bond content is less than 55 mol%, the balance between hysteresis loss and wet skid characteristics will be deteriorated. Further, it is difficult to exceed 90 mol% in a general method for synthesizing a copolymer of an aromatic vinyl compound and a conjugated diolefin.

In the second copolymer rubber of the present invention, the content of the bound aromatic vinyl compound bonded in the polymer chain is 30 to 50% by weight, preferably 30 to 50% by weight, based on the copolymer rubber. ~ 45% by weight. When the content of the bound aromatic vinyl compound is less than 30% by weight, wet skid properties are obtained.
Abrasion resistance and destruction characteristics deteriorate. If it exceeds 50% by weight, the hysteresis loss increases.

Further, the content of 1,2-bonds and / or 3,4-bonds (hereinafter, referred to as vinyl bonds) in the polymerized unit of the conjugated diolefin is determined by the conjugated diolefin in the second copolymer rubber of the present invention. 25 based on polymerized units of the olefin,
To 55 mol%, preferably 28 to 55 mol%, more preferably 30 to 45 mol%. Vinyl bond content is 2
If it is less than 5 mol%, the wet skid characteristics deteriorate and the steering stability is poor. On the other hand, if it exceeds 55 mol%, the breaking strength and abrasion resistance deteriorate, and the hysteresis loss property increases.

One feature of the copolymer rubber of the present invention is that the molecular weight distribution measured by GPC is multimodal (polymodal type). If the molecular weight distribution is monomodal (monomodal type) and the molecular weight distribution is narrow (for example, Mw / Mn is less than 2.0), the viscosity when compounded with a reinforcing agent or other compounding agent increases, and the processability deteriorates. I do. 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 for the purpose of lowering the viscosity of the compound, low hysteresis loss is worsened, and the stickiness of the rubber is increased, handling becomes worse, and the cold flow becomes larger and storage stability is worsened. I do. Further, when the molecular weight distribution is monomodal (monomodal type) and the molecular weight distribution is wide (for example, Mw / Mn is 2.0 or more), the low molecular weight component increases, and the low hysteresis loss performance and wear resistance performance deteriorate. .

The method for making the molecular weight distribution of the copolymer rubber of the present invention measured by GPC multimodal (polymodal type) is not particularly limited. Method (1), after copolymerizing a conjugated diolefin and an aromatic vinyl compound, when a polymerization conversion rate becomes 90% to 100%, a specific coupling agent is added, and the coupling agent is added. It reacts with the active terminal of some polymers to jump the molecular weight. By controlling the amount of the coupling agent to be added, the amount of the polymer whose molecular weight is jumped and the amount of the polymer which does not react with the coupling agent can be controlled to make the molecular weight distribution multimodal. Method (2), a reagent that can deactivate a part of the polymerization active terminal when the polymerization conversion is 50% or less when copolymerizing a conjugated diolefin and an aromatic vinyl compound (a so-called polymerization terminator) Is added. Polymerization terminals that have not been deactivated are
Further, since the remaining monomer is polymerized, the molecular weight increases compared to the deactivated polymer, and the molecular weight distribution becomes multimodal.

Of these, the method (1) of adding a coupling agent is preferable from the viewpoint of the physical properties of the polymer and the productivity. When the polymerization conversion reaches 90% to 100%, the specific coupling agent to be reacted with the polymerization active terminal includes (a) an isocyanate compound and / or
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,
At least one compound selected from the group consisting of (d) silicon compounds, (e) ester compounds, (f) ketone compounds, and (g) tin compounds.

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

Specific examples of the amide compound or 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,
Preferred are imide compounds such as phthalimide and N-methylphthalimide.

Specific examples of the pyridyl-substituted ketone compound or the pyridyl-substituted vinyl compound as the component (c) include:
Dibenzoylpyridine, diacetylpyridine, divinylpyridine and the like can be mentioned as preferred.

The amount of each of the components (a) to (c) is such that a functional group such as an isocyanate group, an isothiocyanate group, a carbonyl group or a vinyl group is usually used in an amount of 0.2 to 1 g atom equivalent of lithium atom. 10 equivalents, preferably 0.5-0.5
It is an amount equivalent to 5.0 equivalents. If it is less than 0.2 equivalent, the effect of vulcanized rubber on rebound resilience and low heat build-up is inferior. On the other hand, if it exceeds 10 equivalents, unreacted substances increase and odor is generated, vulcanization speed is increased, and vulcanization speed is increased. It is not preferable because the resilience of rubber and the effect of low heat generation are reduced.

Specific examples of the silicon compound (d) include dibutyldichlorosilicon, methyltrichlorosilicon, methyldichlorosilicon, tetrachlorosilicon, triethoxymethylsilane, triphenoxymethylsilane, trimethoxysilane, methyltriethoxysilicon. Silane,
Preferred are 4,5-epoxyheptylmethyldimethoxysilane, bis (triethoxysilylpropyl) tetrasulfide, and the like. The halogen atom, the phenoxy group and the ester group are contained in an amount of 0.05 to 5 equivalents, preferably 0.1, per 1 g of the lithium atom.
It can be added in an amount in the range of ~ 1.5 equivalents.

Preferred examples of the ester compound as the component (e) include diethyl adipate, diethyl malonate, diethyl phthalate, diethyl glutarate, diethyl maleate and the like. The ester group is 0.05 to 1.5 per 1 g atom equivalent of lithium atom.
It can be added in an amount falling within the equivalent range.

Specific examples of the ketone compound as the component (f) include N, N, N ′, N′-tetramethyl-4,4′-diaminobenzophenone, N, N, N ′, N′-tetraethyl ( 4,4'-diamino) -benzophenone, N, N-dimethyl-1-aminobenzoquinone, N, N, N ', N'-
Tetramethyl-1,3-diaminobenzoquinone, N, N
-Dimethyl-1-aminoanthraquinone, N, N,
N ', N'-tetramethyl-1,4-diaminoanthraquinone and the like can be mentioned as preferred. A carbonyl group is contained in an amount of 0.0 per 1 g atom equivalent of lithium atom.
It can be added in an amount in the range of 5 to 5 equivalents.

Specific examples of the tin compound (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, Preferred examples include ethyltin tristearate, butyltin trisoctanoate, butyltin tristearate, butyltin trislaurate, dibutyltin bisoctanoate, dibutyltin bisstearate, and dibutyltin bislaurate. The addition amount of the component (g) is such that the halogen atom or the carboxylate group is in the range of 0.05 to 5 equivalents per 1 g of lithium atom.

The polymerization conversion of the copolymer rubber is 90 to 100%.
These compounds to be added and reacted at the time point can be used alone or in combination of two or more. In order to increase the reaction efficiency between the polymerization active terminal and the above compound, after the copolymer rubber is formed, a conjugated diene compound such as 1,3-butadiene is further added to the polymerization system per 1 g atom equivalent of lithium atom, preferably 0.5 to 0.5. 50
0 mol, more preferably 1 to 200 mol,
It is preferable to carry out a terminal modification reaction.

Among the above compounds, (a) an isocyanate compound and / or an isothiocyanate compound,
(D) a silicon compound, (f) a ketone compound and (g)
When at least one of the tin compounds is used, abrasion resistance,
A polymer suitable for low fuel consumption tires or large tires that require low hysteresis performance improvement, or for high performance tires that require steering stability and high breaking strength represented by wet skid performance is obtained. . Extending oil or liquid rubber can be added to the polymer modified or coupled with these compounds. However, if (g) a tin compound is used and a high aromatic extender oil having a viscosity specific gravity of 0.950 or more is used, the tin-carbon bond is cleaved before compounding and the modifying effect is lost. It is preferable to add extender oil or liquid rubber having a specific gravity of 0.800 to 0.950. In addition, among the above compounds, the use of a tin compound (g) has an excellent effect on the improvement of workability aimed at by the present invention, and is particularly preferable. In the present invention, it is preferable that the polymer in which the polymer chain terminal is modified or coupled is contained in an amount of 40% by weight or more in the whole polymer. If it is less than 40% by weight, it is not preferable in view of breaking strength and low hysteresis performance.

The polymerization reaction and the modification or coupling reaction for obtaining the copolymer rubber of the present invention are usually carried out at 0 to 1
The reaction is performed in a temperature range of 20 ° 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.

Also, if necessary, diethyl ether,
Di-n-butyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol dibutyl ether, tetrahydrofuran, 2,2- (bistetrahydrofurfuryl) propane, bistetrahydrofur Ether compounds such as furyl formal, methyl ether of tetrahydrofurfuryl alcohol, ethyl ether of tetrahydrofurfuryl alcohol, butyl ether of tetrahydrofurfuryl alcohol, α-methoxytetrahydrofuran, dimethoxybenzene, dimethoxyethane and / or
Or triethylamine, pyridine, N, N, N ', N'
Tertiary amine compounds such as tetramethylethylenediamine, dipiperidinoethane, methyl ether of N, N-diethylethanolamine, ethyl ether of N, N-diethylethanolamine, and butyl ether of N, N-diethylethanolamine; , Added into the polymerization system,
The microstructure (vinyl bond content) of the conjugated diolefin portion of the diolefin (co) polymer can be adjusted.

Preferred hydrocarbon solvents used when polymerizing the copolymer rubber of the present invention include, for example, pentane,
Hexane, heptane, octane, methylcyclopentane, cyclohexane, benzene, xylene and the like can be mentioned.

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

These potassium compounds can be added in an amount of from 0.005 to 0.5 mole per gram atomic equivalent of lithium of the organolithium compound used to form 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 performing the reaction for modifying the polymer terminal with a functional group is reduced.

When the polymer of the present invention is polymerized using an alkali metal amide initiator, the polymerization reaction activity is improved, and the reaction efficiency between the polymer active terminal and a modifier (coupling agent) is improved. For this purpose, an alkali metal alkoxide compound may be added together with the polymerization initiator. The alkali metal alkoxide compound can be a reaction between an alcohol having a corresponding structure and an organic alkali metal compound, and the reaction is performed before copolymerizing the conjugated diolefin and the aromatic vinyl compound in a hydrocarbon solvent. The reaction may be performed in the presence of the monomer. Preferred examples of the alkali metal alkoxide compound include alkali metal alkoxides such as tetrahydrofurfuryl alcohol, N, N-dimethylethanolamine, N, N-diethylethanolamine and 1-piperazineethanolamine.

As an organic alkali metal compound to be reacted with an alcohol compound to form an alkali metal alkoxide, an organic lithium compound is preferable. For example, ethyl lithium, propyl lithium, n-butyl lithium, sec-butyl lithium, t-butyl lithium,
Hexyllithium or a mixture thereof can be mentioned, and preferred are n-butyllithium and sec-butyllithium. The molar ratio between the alcohol compound and the organolithium compound needs to be 1: 0.7 to 5.0, preferably in the range of 1: 0.8 to 2.0,
More preferably, it is 1: 0.9 to 1.2. If the molar ratio of the organolithium compound exceeds 5.0, the effects of improving breaking strength, abrasion resistance, and low hysteresis cannot be obtained. On the other hand, when the molar ratio of the organolithium compound is less than 0.8, the polymerization rate is remarkably reduced, the productivity is significantly reduced, and the reaction for modifying the polymer terminal with a functional group is performed. Denaturation efficiency decreases.

In the present invention, in preparing an initiator comprising a reaction product of a secondary amine compound or a tertiary amine compound and an organolithium compound, the reaction is carried out, and then, such as 1,3-butadiene or isoprene is used. A conjugated diolefin compound in an amount of 1 to 100 times by mole the initiator component,
It is preferable to use it for the main polymerization after preliminarily polymerizing by adding 1 to 50 times mol since it is preferable because the polymerization reaction starts promptly.

Further, the Mooney viscosity (ML1 + 4, 100 ° C.) of the copolymer rubber obtained in the present invention is preferably in the range of 20 to 200. If it is less than 20, the breaking strength, abrasion resistance, and low hysteresis loss deteriorate. , 200, the workability decreases. In addition, Mooney viscosity (ML1 +
(100.degree. C., 100.degree. C.) is inferior in processability as it is, which is not preferable. However, extender oils such as aromatic process oils and naphthene process oils and liquid polymers having an average molecular weight of 150,000 or less are added. Thus, the Mooney viscosity can be reduced to 100 or less, so that it can be used without any problem in processing. However, when an aromatic process oil having a viscosity specific gravity of more than 0.950 is added to the polymer modified or coupled with the tin compound of the component (g), the tin-carbon bond is easily cleaved.
It is preferable to add extender oil or liquid rubber having a viscosity specific gravity (VGC) of 0.800 to 0.950.

The polymerization reaction solution containing the copolymer rubber obtained in the present invention may be prepared by a method used in a conventional solution polymerization method, for example, after adding a stabilizer or the like in a solution state, and then, if necessary, an aromatic system. Process oil, extender oil such as naphthenic process oil or liquid polymer having an average molecular weight of 150,000 or less (or a solution of the liquid polymer) is added,
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 isolate the desired copolymer rubber of the present invention.

The copolymer rubber of the present invention may be used alone or blended with natural rubber, polyisoprene rubber, polybutadiene rubber, emulsion-polymerized styrene-butadiene rubber and the like, and reinforcing agents such as carbon black and silica and various compounding agents,
After kneading by roll and Banbury mixer,
It can be used for tires such as treads, sidewalls and carcass, as well as belts, anti-vibration rubber and other industrial products by adding sulfur, vulcanization accelerators and the like.

When the copolymer rubber of the present invention is used for a tire, particularly for a tire tread, reinforcing materials to be filled include carbon black, 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 preferably 20 to 110 parts by weight based on 100 parts by weight of the total rubber component. Also, in particular,
For low fuel consumption tire applications, silica is preferably used for the purpose of reducing hysteresis loss of the vulcanizate to give good rolling resistance and improving wet skid resistance. The amount of the silica is preferably 20 to 120 parts by weight based on 100 parts by weight of the total rubber component.

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

Further, the copolymer rubber of the present invention is added to a carbon-silica dual phase filler (Dual Ph).
As a result, the same advantages as when carbon black and silica are used in combination can be obtained. Carbon-silica dual-phase filler is a so-called silica coating, in which silica is chemically bonded to the surface of carbon black.
Carbon black, trade name CR from Cabot Corporation
X2000, CRX2002 and CRX2006.

[0065] Carbon-silica dual phase
The amount of the filler is preferably 1 to 100 parts by weight, more preferably 5 to 100 parts by weight of the total of the rubber components.
９５95 parts by weight. In the present invention, carbon-silica
Dual phase fillers can be used in combination with other fillers. Examples of the filler that can be used in combination include, but are not limited to, carbon black, silica, calcium carbonate, and magnesium carbonate. Among them, carbon black and silica are preferred.
These fillers that can be used together have a total amount of rubber component of 100%.
It is preferable to add 3 to 100 parts by weight, particularly 5 to 95 parts by weight, based on parts by weight.

[0066]

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.

The conjugated diolefin moiety 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 . Glass transition temperature was measured according to ASTM D3418. 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, a preheating time of 1 minute, a rotor operation time of 4 minutes, and a temperature of 100 ° C.

Coupling efficiency Gel permeation chromatography (GPC)
It was calculated from the peak area ratio between the polymer before coupling and the polymer whose molecular weight was increased by coupling from the obtained GPC curve measured by using (Type 244, manufactured by Water Corporation).

The amino group content (mmo) bonded to the polymer
1 / g Copolymer rubber polymer) First, after dissolving the polymer in toluene, the amino group-containing compound not bonded to the copolymer rubber was separated from the rubber by precipitation in a large amount of methanol, and then dried.
Using the copolymerized rubber subjected to this treatment as a sample,
・ Kean, James S. Fritz, J.M. Anal.
Chem. , Vol. 24, p. 564 (1952), "acid-base titration in an organic solvent using a perchloric acid-acetic acid solution". Chloroform is used as the solvent for dissolving the sample, and methyl violet is used as the titration indicator.
According to the calibration curve prepared with the n-octylamine solution,
Quantified. By dividing the quantitative value (mmol) by the weight of the polymer used in the analysis, the content of the amino group bound to the target polymer (mmol / g · copolymer rubber polymer)
I asked.

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.

[0071]

[Table 1]

The tensile strength was measured according to JIS K6301. tan δ (50 ° C.), tan δ (0 ° C.) Using a dynamic spectrometer manufactured by Rheometrics of the United States, measurement was performed under the conditions of a tensile dynamic strain of 1%, a frequency of 10 Hz, and 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 20 g of cyclohexane, 5 g of tetrahydrofuran, and 100 g of a pressure-resistant bottle sufficiently filled with nitrogen
Di-n-butylamine (4.84 mmol) as a secondary amine
and then plugged. Then, n-butyllithium 4.8 was added.
After adding 4 mmol and reacting at 50 ° C. for 15 minutes,
1.39 g (25.8 mmol) of 1,3-butadiene was added, and the mixture was further reacted for 15 minutes. Next, 2,500 g of cyclohexane, 23.13 g of tetrahydrofuran, 100 g of styrene, and 390 g of 1,3-butadiene were charged into a 5-liter autoclave reaction vessel sufficiently substituted with nitrogen. After adjusting the temperature of the contents of the reaction vessel to 10 ° C., the entire amount of the above initiator solution was added to initiate polymerization. After the polymerization conversion reaches 100%, 1,3
-10 g of butadiene was added and reacted for 5 minutes to convert the polymer end into butadienyl lithium, and then 0.91 mmol of tin tetrachloride was added to carry out a coupling reaction for 15 minutes. The manufacturing conditions are shown in Table 2. After the reaction, 2,6-di-t-butyl-p-cresol was added to the polymer solution, and the solvent was removed by steam stripping.
The rubber was dried with a hot roll at 15 ° C. Table 3 shows the physical properties and the like of the obtained copolymer rubber (hereinafter, referred to as polymer A-1).

Example 2 Di-n-butylamine (4.84 mmol) as a secondary amine
4.8 instead of pyrrolidine (tetramethylene imine)
Except for using 4 mmol, a copolymer rubber (hereinafter referred to as polymer B-1) was obtained with the same formulation as polymer A-1.
Table 2 shows the production conditions and physical properties of the polymer B-1.
And Table 3.

Example 3 To a 5-liter autoclave reaction vessel charged with cyclohexane, tetrahydrofuran, 1,3-butadiene and styrene, 4.84 mmol of pyrrolidine (tetramethyleneimine) was added in advance, and then n-butyllithium .84 mmol was added directly to obtain a copolymer (hereinafter, referred to as polymer C-1) in the same manner as polymer B-1. The production conditions and physical properties of the polymer C-1 are shown in Tables 2 and 3, respectively.

Example 4 A polymer C-C was prepared except that 2.42 mmol of N, N-diethylethanolamine was charged into an autoclave reactor, and 7.26 mmol of n-butyllithium was added.
In the same manner as in Example 1, a copolymer rubber (hereinafter referred to as polymer D-1) was obtained. The production conditions and physical properties of the polymer D-1 are shown in Tables 2 and 3, respectively.

Examples 5 to 12 and Comparative Examples 1 to 6 Tetrahydrofuran, 1,3-butadiene, styrene,
The amounts of pyrrolidine (tetramethyleneimine), n-butyllithium, and the modifying agent were as shown in Table 2, and the polymerization temperature was adjusted to the temperature shown in Table 3, to obtain a polymer in the same manner as in Polymer C-1. Tables 2 and 3 show the production conditions, physical properties, and the like of the polymer in each example.

Example 13 When adjusting the initiator in a pressure bottle, 4.84 mmol of N, N-dimethyl-o-toluidine was used instead of 4.84 mmol of di-n-butylamine, and the coupling reaction after polymerization was carried out. A copolymer rubber (hereinafter referred to as polymer M-1) was obtained with the same formulation as polymer A-1, except that 1.84 mmol of dioctyltin dichloride was used in place of 0.91 mmol of tin tetrachloride as a coupling agent used for the above. . The production conditions and physical properties of the polymer M-1 are shown in Tables 2 and 3, respectively.

Example 14 When adjusting the initiator in a pressure bottle, 4.84 mmol of vinylbenzyldimethylamine (VBDMA) was used instead of 4.84 mmol of di-n-butylamine, and used for the coupling reaction after polymerization. A copolymer rubber (hereinafter referred to as polymer N-1) was prepared in the same manner as polymer A-1, except that 1.82 mmol of dioctyltin dichloride was used instead of 0.91 mmol of tin tetrachloride as a coupling agent.
). The production conditions and physical properties of the polymer N-1 are shown in Tables 2 and 3, respectively.

Example 15 and Comparative Example 7 Tetrahydrofuran, 1,3-butadiene, styrene,
The amounts of pyrrolidine (tetramethyleneimine), n-butyllithium, and the modifier were set as shown in Table 2, and the polymerization temperature was adjusted to the polymerization temperature shown in Table 3, and a polymer solution was obtained in the same manner as in Polymer C-1. . Polymer 100 in the resulting polymer solution
37.5 parts by weight of solution-polymerized SBR rubber based on parts by weight (vinyl content = 62%, bound ST amount = 25%, weight average molecular weight (Mw) = 10,000, weight average molecular weight (Mw) and number average) Ratio to molecular weight (Mn) (Mw / Mn) = 1.0
After the addition of 5), 2,6-di-t-butyl-p-cresol was added, the solvent was removed by steam stripping, and the rubber was dried with a hot roll at 115 ° C. The production conditions and physical properties of the obtained polymer are shown in Tables 2 and 3, respectively.

Example 16 and Comparative Example 8 Tetrahydrofuran, 1,3-butadiene, styrene,
The amounts of pyrrolidine (tetramethyleneimine), n-butyllithium, and the modifier were set as shown in Table 2, and the polymerization temperature was adjusted to the polymerization temperature shown in Table 3, and a polymer solution was obtained in the same manner as in Polymer C-1. . Polymer 100 in the resulting polymer solution
After adding 37.5 parts by weight of the aromatic oil to the parts by weight, 2,6-di-t-butyl-p-cresol was added, and the solvent was removed by steam stripping. To dry the rubber. The production conditions and physical properties of the obtained polymer are shown in Tables 2 and 3, respectively.
It was shown to.

[0083]

[Table 2]

[0084]

[Table 3]

Evaluation of Physical Properties of Rubber Compositions Reference Examples 1 to 14 and Comparative Reference Examples 1 to 5 (Carbon Black Low Filling Compound) Styrene-butadiene copolymer rubber without extension oil or liquid rubber was added to A in Table 1. A vulcanized product was prepared under the conditions of the “carbon black-based low-filling compounding” shown, 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 Reference Example 1 (Polymer Q-
It is represented by an index with the value of 1) being 100, and the larger the numerical value of any physical property, the better. Table 4 shows the polymers used for the evaluation and the physical property evaluation results.

[0086]

[Table 4]

Reference Examples 15 to 19 and Comparative Reference Examples 6 to 8
(Carbon Black High Filling Compound) A vulcanizate was produced under the conditions of “Carbon Black High Filling Compound” shown in Table 1B, and physical properties were evaluated. Tensile strength, t
The values of an δ (0 ° C.), tan δ (50 ° C.), and Lambourn abrasion were 1 in Comparative Reference Example 6 (Polymer Q-1).
It is represented by an index of 00, and the larger the number, the better the physical properties. Table 5 shows the polymers used for the evaluation and the physical property evaluation results.

[0088]

[Table 5]

Reference Examples 20 to 22 and Comparative Reference Examples 9-1
3 (Silica-based high-filling compound) A styrene-butadiene copolymer rubber was vulcanized under the conditions of “silica-based high-filling compound” shown in C of Table 1 to evaluate its physical properties. Tensile strength, tan δ (0 ° C), tan δ
(50 ° C.) and the physical properties of Lambourn abrasion are shown in Comparative Reference Example 1.
0 (Polymer Q-1) expressed as an index with the value of 100;
In each case, the larger the number, the better. Table 6 shows the polymers used for the evaluation and the physical property evaluation results.

[0090]

[Table 6]

Reference Examples 23 to 25 and Comparative Reference Examples 14 to
18 (Carbon Black / Silica High Filling Compound) A styrene-butadiene copolymer rubber was vulcanized under the conditions of “Carbon Black / Silica High Filling Compound” shown in Formulation D of Table 1 to evaluate its physical properties. . Tensile strength, tan δ
(0 ° C.), tan δ (50 ° C.), and physical property values of Lambourn abrasion were 100 values of Comparative Reference Example 15 (Polymer Q-1).
The larger the number, the better. Table 7 shows the polymers used for the evaluation and the results of the physical property evaluation.
Shown in

[0092]

[Table 7]

Tables 4 to 7 show the following. From the evaluation results of the carbon black-based low filling compound in Table 4,
The diolefin copolymer having an amino group introduced at the polymerization terminal of the present invention has a wet skid performance while maintaining the abrasion resistance of a conventional polymer having no amino group introduced at the polymerization terminal at or above the same level. (Tan δ, 0 ° C) while maintaining the breaking strength, abrasion resistance and low hysteresis performance (tan δ, 5).
0 ° C.) is improved. Further, the active terminal of the polymer polymerized with the initiator of the present invention,
It can be seen that the effect of improving various physical properties is remarkable by modifying with a tin compound, an amide compound, a pyridyl-substituted ketone compound, an ester compound, and the like, and efficiently introducing functional groups at both ends of the molecular chain. Comparative Reference Example 5 in Table 4, Comparative Reference Example 11 in Table 6 and Comparative Example 16 in Table 7 are polymers having a monomodal molecular weight distribution in which an amino group is introduced at a polymerization terminal, but have poor extrusion processability. It can be seen that the breaking strength, abrasion resistance and low hysteresis performance (tan δ, 50 ° C.) also deteriorated.

Table 5 Evaluation by Carbon Black High Filling Compound, Table 6 Evaluation by Silica High Filling Compound, Table 7
From the evaluation of the silica / carbon black combined system high-filling blend, it can be seen that the polymer of the present invention has an effect of improving various physical properties as compared with the conventional polymer in any blending.

Example 21 20 g of cyclohexane, 5 g of tetrahydrofuran, and 100 g of a pressure-resistant bottle sufficiently filled with nitrogen
Di-n-butylamine (4.84 mmol) as a secondary amine
and then plugged. Then, n-butyllithium 4.8 was added.
After adding 4 mmol and reacting at 50 ° C. for 15 minutes,
1.39 g (25.8 mmol) of 1,3-butadiene was added, and the mixture was further reacted for 15 minutes. Next, 2,500 g of cyclohexane, 5.00 g of tetrahydrofuran, 175 g of styrene, 175 g of styrene, and 1,3-butadiene 1 were placed in an autoclave reaction vessel having an inner volume of 5 liters sufficiently substituted with nitrogen.
75 g were charged. After adjusting the temperature of the contents of the reaction vessel to 55 ° C., the entire amount of the above initiator solution was added to initiate polymerization. After the initiation of the polymerization, when the color of the reaction solution, which was yellow, became slightly reddish, 1,3-butadiene 140
g was continuously charged into the reactor (charge rate was adjusted so that the solution did not turn red). After the polymerization conversion reaches 100%, 10 g of 1,3-butadiene
Was added and reacted for 5 minutes to convert the polymer end into butadienyl lithium, and then 0.91 mmol of tin tetrachloride was added to carry out a coupling reaction for 15 minutes. Table 8 shows the manufacturing conditions. After the reaction, 2,6-di-t-
Butyl-p-cresol was added, the solvent was removed by steam stripping, and the rubber was dried with a hot roll at 115 ° C. Table 9 shows the physical properties and the like of the obtained copolymer rubber (hereinafter, referred to as polymer A-2).

Example 22 As a secondary amine di-n-butylamine 4.84 mmol
4.8 instead of pyrrolidine (tetramethylene imine)
Except for using 4 mmol, a copolymer rubber (hereinafter referred to as polymer B-2) was obtained with the same formulation as polymer A-2.
Table 8 shows the production conditions and physical properties of Polymer B-2.
And Table 9.

Example 23 To a 5-liter autoclave reaction vessel charged with cyclohexane, tetrahydrofuran, 1,3-butadiene, and styrene, 4.84 mmol of pyrrolidine (tetramethyleneimine) was added in advance, and then n-butyllithium was added. .84 mmol was added directly and copolymer rubber (hereinafter referred to as polymer C-2) was prepared in the same manner as polymer B-2.
). Tables 8 and 9 show the production conditions and physical properties of the polymer C-2.

Example 24 A polymer C was prepared except that 2.42 mmol of N, N-diethylethanolamine was charged into an autoclave reaction vessel, and 7.26 mmol of n-butyllithium was added.
A copolymer rubber (hereinafter, referred to as polymer D-2) was obtained in the same manner as in Comparative Example-2. Tables 8 and 9 show the production conditions and physical properties of the polymer D-2.

Examples 25 to 32 and Comparative Examples 11 to 17 Tetrahydrofuran, 1,3-butadiene, styrene,
The amounts of pyrrolidine (tetramethyleneimine), n-butyllithium, and the modifying agent were as shown in Table 8, and the polymerization temperature was adjusted to the temperature shown in Table 9, and a polymer was obtained in the same manner as in Polymer C-2. Tables 8 and 9 show the production conditions and physical properties of the polymer in each example.

Example 33 When adjusting the initiator in a pressure bottle, 4.84 mmol of N, N-dimethyl-o-toluidine was used instead of 4.84 mmol of di-n-butylamine, and the coupling reaction after polymerization was carried out. A copolymer rubber (hereinafter referred to as polymer M-2) was obtained with the same formulation as polymer A-2 except that 1.82 mmol of dioctyltin dichloride was used instead of 0.91 mmol of tin tetrachloride as a coupling agent used in the above. . Tables 8 and 9 show the production conditions, physical properties, and the like of the polymer M-2.

Example 34 When adjusting the initiator in a pressure bottle, 4.84 mmol of vinylbenzyldimethylamine (VBDMA) was used instead of 4.84 mmol of di-n-butylamine, and used for the coupling reaction after polymerization. The copolymer rubber (hereinafter referred to as polymer N-2) has the same formulation as polymer A-2 except that 1.82 mmol of dioctyltin dichloride is used instead of 0.91 mmol of tin tetrachloride as a coupling agent.
). Tables 8 and 9 show the production conditions and physical properties of the polymer N-2.

Examples 35 and 37 and Comparative Example 18 Tetrahydrofuran, 1,3-butadiene, styrene,
The amounts of pyrrolidine (tetramethyleneimine), n-butyllithium, and the modifier were set as shown in Table 8, and the polymerization temperature was adjusted to the temperature shown in Table 9, and a polymer solution was obtained in the same manner as in Polymer C-2. . Polymer 100 in the resulting polymer solution
37.5 parts by weight of solution-polymerized SBR rubber based on parts by weight (vinyl content = 62%, bound ST amount = 25%, weight average molecular weight (Mw) = 10,000, weight average molecular weight (Mw) and number average) Ratio to molecular weight (Mn) (Mw / Mn) = 1.0
After the addition of 5), 2,6-di-t-butyl-p-cresol was added, the solvent was removed by steam stripping, and the rubber was dried with a hot roll at 115 ° C. The production conditions and physical properties of the obtained polymer are shown in Tables 8 and 9, respectively.

Examples 36 and 38 and Comparative Example 19 Tetrahydrofuran, 1,3-butadiene, styrene,
The amounts of pyrrolidine (tetramethyleneimine), n-butyllithium, and the modifier were set as shown in Table 8, and the polymerization temperature was adjusted to the temperature shown in Table 9, and a polymer solution was obtained in the same manner as in Polymer C-2. . Polymer 100 in the resulting polymer solution
After adding 37.5 parts by weight of the aromatic oil to the parts by weight, 2,6-di-t-butyl-p-cresol was added, and the solvent was removed by steam stripping. To dry the rubber. The production conditions and physical properties of the obtained polymer are shown in Tables 8 and 9 respectively.
It was shown to.

[0104]

[Table 8]

[0105]

[Table 9]

Evaluation of Physical Properties of Rubber Composition Reference Examples 31 to 43 and Comparative Reference Examples 21 to 27 (compounds for carbon black low fuel consumption tires) Styrene-butadiene copolymer rubber without extension oil or liquid rubber was used as shown in Table 1. A vulcanized product was prepared under the conditions of “compound for carbon black fuel-efficient tires” shown in A, and the physical properties were evaluated. Tensile strength, tan δ (0 ° C.), tan δ (50
° C) and the physical properties of Lambourn abrasion are expressed as indices with the value of Comparative Reference Example 21 (Polymer S-2) as 100, and the larger the number, the better. Table 10 shows the polymers used for the evaluation and the physical property evaluation results.

[0107]

[Table 10]

Reference Examples 44 to 48 and Comparative Reference Examples 28 to
30 (Compound for carbon black-based high-performance tire) A vulcanized product was produced under the conditions of “compound for carbon black-based high-performance tire” shown in Table 1B, 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 Reference Example 28 (Polymer S-
It is represented by an index with the value of 2) being 100, and the larger the numerical value of any physical property, the better. Table 11 shows the polymers used for the evaluation and the physical property evaluation results.

[0109]

[Table 11]

Reference Examples 49 to 54 and Comparative Reference Examples 31 to
34 (Blending for Silica-Based Low Fuel Consumption Tires) A styrene-butadiene copolymer was vulcanized under the conditions of “Blending for Silica-based Low Fuel Consumption Tires” shown in Table 1C.
Physical properties were evaluated. Tensile strength, tan δ (0 ° C), ta
The values of nδ (50 ° C.) and the physical properties of Lambourn abrasion are expressed as indices with the value of Comparative Reference Example 31 (Polymer S-2) being 100. The larger the numerical value of each physical property, the better. Table 12 shows the polymers used for the evaluation and the physical property evaluation results.

[0111]

[Table 12]

Reference Examples 55 to 60 and Comparative Reference Examples 35 to
38 (Compound for carbon black / silica combined fuel-efficient tire) A styrene-butadiene copolymer rubber was vulcanized under the conditions of “Carbon black / silica highly filled compound” shown in Formulation D of Table 1, and physical properties were evaluated. Was done. Tensile strength, tan δ
(0 ° C.), tan δ (50 ° C.), and the physical property value of Lambourn abrasion were obtained by comparing the value of Comparative Reference Example 35 (Polymer S-2) with 100.
The larger the number, the better. Table 1 shows the polymers used for the evaluation and the physical property evaluation results.
3 is shown.

[0113]

[Table 13]

Tables 8 to 13 show the following.
According to the evaluation results of the carbon black-based fuel-efficient tire compound shown in Table 10, the diolefin-based copolymer rubber having an amino group introduced at the polymerization terminal of the present invention is a wet skid of a polymer obtained from a conventional organolithium compound. Performance (tan
It can be seen that the balance between the breaking strength, the wear resistance and the low hysteresis performance (tan δ, 50 ° C.) is improved while maintaining (δ, 0 ° C.). Further, the active terminal of the polymer polymerized with the initiator of the present invention, a tin compound, an amide compound,
It can be seen that, by modifying with a pyridyl-substituted ketone compound, an isocyanate compound, or the like, and efficiently introducing functional groups at both ends of the molecular chain, the effect of improving various physical properties is remarkable. Comparative Reference Example 27 is a polymer having a monomodal molecular weight distribution in which an amino group is introduced into a polymerization terminal, but has poor extrusion workability, and also has poor breaking strength, abrasion resistance and low hysteresis performance (tan δ, 50 ° C.). You can see that it is doing.

The evaluation based on the formulation for the carbon black-based high-performance tire shown in Table 11, the evaluation based on the formulation for the silica-based low fuel consumption tire shown in Table 12, and the evaluation based on the combination for the silica / carbon black combined fuel-efficient tire shown in Table 13 are also obtained from the present invention. It can be seen that the polymer of the present invention has an effect of improving various physical properties as compared with a polymer obtained from a conventional organic lithium in any of the formulations.

[0116]

According to the present invention, a specific content of a polymerized unit of an aromatic vinyl compound, a specific vinyl bond content in a polymerized unit of a conjugated diolefin, and a specific GPC
Provided is a diolefin-based copolymer rubber having a molecular weight distribution and having an amino group introduced into a terminal. By using such a diolefin-based copolymer rubber, it has good workability in both the compounding of carbon black and the compounding of silica, and simultaneously improves the wet skid characteristics, abrasion resistance and fracture characteristics in a well-balanced manner. And especially high performance tires,
Tread rubbers such as low fuel consumption tires and all season tires can be suitably used.

────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification symbol FI // (C08F 236/14 212: 04) (72) Inventor Iwawa Hattori 2-1-2-11 Tsukiji, Chuo-ku, Tokyo JSR Inside the corporation

Claims (8)

[Claims] 1. A copolymer rubber of a conjugated diolefin and an aromatic vinyl compound, wherein (1) the amino group content (nitrogen content) bonded to the rubber is 0.0025 to 0.20 mmol.
/ G · copolymer rubber polymer, wherein (2) the content of polymerized units of the aromatic vinyl compound is 5% by weight or more and less than 30% by weight based on the copolymer rubber, and (3) polymerization of conjugated diolefin The vinyl bond content (content of 1,2 bond and 3,4 bond) in the unit is 55 mol% or more based on the polymerized unit of the conjugated diolefin, and (4) the molecular weight distribution is polymodal. A copolymer rubber characterized in that: 2. A copolymer rubber of a conjugated diolefin and an aromatic vinyl compound, wherein (1) the amino group content (nitrogen content) bonded to the rubber is 0.0025 to 0.20 mmol.
/ G · copolymer rubber polymer, and (2) the content of the polymerized unit of the aromatic vinyl compound is 30 based on the copolymer rubber.
And (3) a vinyl bond content (1,2 bond and 3,4 bond) in the polymerized unit of the conjugated diolefin.
(Bond content) is 25 to 55 mol% based on the polymerized units of the conjugated diolefin, and (4) the copolymer has a molecular weight distribution of a polymodal type. 3. The copolymer rubber according to claim 1, wherein at least 40% of the polymerization termination terminal is (a) an isocyanate compound and / or an isothiocyanate compound, (b) an amide compound and / or an imide compound, and (c) a pyridyl-substituted ketone compound. And / or a pyridyl-substituted vinyl compound, (d)
The copolymer rubber according to claim 1, wherein the copolymer rubber is modified or coupled with at least one compound selected from the group consisting of a silicon compound, (e) an ester compound, (f) a ketone compound, and (g) a tin compound. . 4. The polymerization rubber wherein at least 40% of the polymerization termination terminal is modified with at least one compound selected from the group consisting of the compounds (a), (b), (f) and (g). The copolymer rubber according to claim 1 or 2, which is coupled. 5. The method according to claim 1, wherein the amino group has the following formula (a1) and / or
Or (a2): (Wherein, R ¹ represents hydrogen (—H), an alkyl group having 1 to 20 carbon atoms, or an aryl group having 6 to 20 carbon atoms;
² is an alkyl group having 1 to 20 carbon atoms or 6 to 20 carbon atoms
Represents an aryl group. ) (Wherein, R ³ and R ⁴ are the same or different and each have 1 carbon atom)
Indicates to 3 alkylene group, X is -CH ₂ -, - represents a group selected from O- and -NH-, R ⁵ is hydrogen (-
H) or an alkyl group having 1 to 5 carbon atoms, and k represents an integer of 1 to 4. 3. The copolymer rubber according to claim 1, having a structure represented by the formula: 6. 100 parts by weight of a total rubber component containing the copolymer rubber according to claim 1 and carbon black, silica and carbon black / silica.
A rubber composition comprising 20 to 120 parts by weight of at least one filler selected from the group consisting of dual phase fillers. 7. The rubber composition according to claim 6, which is used for a tire tread. 8. A tire wherein the tire tread comprises the rubber composition according to claim 6.