JPS62149708A - Improved rubber for tire tread - Google Patents

Abstract

PURPOSE:To obtain the titled rubber excellent in tensile strength, resiliency, resistance to heat build-up, etc., by introducing a terminal modifying group having a specified atomis group into each terminal of a conjugated diolefin polymer or a conjugated diolefin/vinyl aromatic compound copolymer. CONSTITUTION:The purpose rubber-like polymer of a MW distribution <=2.2 and a Mooney viscosity of 15-150 is obtained by introducing a terminal modifying group having an atomic group containing an element selected from among those of Groups IV, V and VI of the perioddic table and having an electronegativity satisfying the formula into each terminal of a conjugated diolefin homopolymer or of a copolymer of a conjugated diolefin with a vinyl aromatic compound. This polymer is obtained by, for example, a method comprising polymerizing a conjugated diolefin monomer by using, e.g., a dilithium catalyst to obtain a living diolefin polymer containing lithium on each terminal and introducing a modifying group into each terminal by reaction with a specified vinyl compound (e.g., p-dimethylaminostyrene).

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a conjugated diolefin polymer or copolymer produced using an alkyllithium catalyst and suitable for the tread of fuel-efficient tires.

[Conventional technology and its problems]

In recent years, due to the soaring price of crude oil, energy conservation has been advocated in various industries, including automobiles.
Many attempts have been made to reduce gasoline consumption.
The engine has been improved, the weight of the car body and tires has been reduced, and the air resistance of the car body and the rolling resistance of the tires have been reduced.

In our efforts to save energy related to automobiles,
Various attempts have been made to reduce the rolling resistance of automobile tires, such as improving the tire structure and improving the vulcanized rubber used in tire treads. In an attempt to reduce roller resistance, there is a method to improve vulcanized rubber, that is, a method to reduce energy loss of vulcanized rubber and improve rebound resilience or heat generation. How to improve the raw material rubber used, how to change the type of carbon black,
Methods of reducing the amount of carbon black or oil used in vulcanized rubber to achieve high repulsion elasticity are being considered.Among the above improvement methods, methods of improving the raw material rubber include methods that improve the raw material rubber. Knowledge of the physical properties of rubber and vulcanized rubber shows that although it is possible to improve rebound by using polymers with higher molecular weights than conventional ones, the Mooney viscosity of the rubber and compound increases, making processability difficult. It is not possible to make major improvements because of the decrease in On the other hand, by changing the combination prescription,
Even in the method of reducing the blended amounts of oil and carbon black, the Mooney viscosity of the compound increases, and even in this case, the processability is not bad, so it is impossible to improve the processability without sacrificing the processability. difficult.

Incidentally, in recent years, it has been found that random styrene-butadiene copolymer rubber having a branched structure with many vinyl bonds is suitable for use in tire applications. Rubbers with various structures have been studied and various proposals have been made. For example, when tin-coupling styrene-butadiene copolymer rubber with an increased vinyl content to form a branched styrene-butadiene copolymer rubber, adding butadiene to the polymerization immediately before the camping reaction increases the rolling resistance. Improved methods have been proposed (Japanese Patent Application Laid-Open No. 57-87407, Japanese Patent Application Laid-Open No. 58-162605). However, even with this method, it cannot be said that the improvement of the 9-resistance is sufficient, and there are problems such as the manufacturing method becomes complicated.

In addition, completely random styrene butylene is produced by continuously introducing monomer into a polymerization zone with high stirring efficiency and controlling the temperature at 80°C or higher using a catalyst consisting of an organolithium compound and a Lewis base, and allowing the polymerization to proceed. Gen copolymer rubber has been proposed (Japanese Patent Application Laid-Open No. FJf357-1
00112). This polymer showed excellent performance in terms of tensile strength, rebound resilience, low heat generation, abrasion resistance, wet skid properties, etc. However, this copolymer rubber also needed to be further improved in terms of impact resilience, low heat build-up, and the like.

In addition to this, various methods have been proposed for improving raw rubber, including introducing functional groups at the ends of polymers.

For example, a method in which a benzophenone having a substituent at the terminal of a living polymer is reacted (Japanese Patent Application Laid-open No. 16260/1983)
4, % Japanese Patent Application Laid-open No. 189203-1983), those in which a compound having a 10-N- bond is reacted at the end of a living polymer (Japanese Patent Application Laid-open No. 137913-1983, Japanese Patent Application Laid-open No. 137914-1982) Although there have been some improvements in rebound resilience, low heat generation, abrasion resistance, etc., the improvements have not been sufficient.

There is also a proposal to use lithium amide as an initiator to obtain a conjugated diene polymer in which a tertiary amino group is introduced at one end of the polymer, and then to couple it in a branched manner with a coupling agent (Unexamined Japanese Patent Publication No. Publication No. 59-38209)
However, because lithium amide was used as an initiator, polymerization initiation was not uniform, the molecular weight distribution was abnormally expanded, and polymerization was difficult to proceed, making it difficult to obtain a polymer with a high molecular weight. Improvements in heat generation properties, #4 abrasion properties, etc. were insufficient.

Furthermore, there is a proposal for introducing an anionically polymerizable monomer having a tertiary amino group as a functional group into the polymer chain (Japanese Unexamined Patent Publication No. 154742/1982), but this method has poor rebound properties and low heat generation. There was no improvement in properties such as durability and abrasion resistance.

In addition, there is a proposal to perform polymerization using lithium naphthalene or sodium naphthalene as an initiator, and then react with organic sulfenyl chloride to modify both terminals (Japanese Patent Publication No. 1985-855), but the dilithium catalyst is incomplete. Because of this, the molecular weight distribution is extremely expanded, and only one end becomes a living room.
No improvement in wear resistance was made.

Therefore, the problem to be solved by the present invention is to provide a rubber composition that does not impair wet skidding properties, processability, etc., and has extremely excellent properties in terms of modulus, tensile strength, rebound resilience, low heat build-up, and abrasion resistance. As a result of extensive research to develop this, we have come to invent a specific conjugated diolefin polymer or copolymer.

[Means and effects for solving the problems] That is, the present invention provides a conjugated diolefin polymer or a conjugated diolefin/
A copolymer of a vinyl aromatic compound and a vinyl aromatic compound, wherein both ends of the polymer are selected from Groups Ⅰ, Ⅲ, and Ⅲ of the periodic table, and the electronegativity satisfies the formula 0.41≦. −≦0.60
(In the formula, Xp is the electronegativity of the atom, and N is the periodic table group number of the atom.) At least 1f
It has a terminal modified group having an atomic group containing Ii, and the molecular weight distribution ('hk /Mn) of the polymer or copolymer is 2.
2 or less, and the 5-2-viscosity (ML1'::Cn is 15
100 parts by weight of raw rubber containing at least 10% by weight of this in the rubber component, 10-100 parts by weight of carbon black, 0.3 # of sulfur.
To provide a rubber composition suitable for a tire tread, which is blended with a five-layer compound and a vulcanization accelerator.

The present invention will be described in detail below.

The rubber-like conjugated diolefin polymer or the copolymer of a conjugated diolefin and a vinyl aromatic compound (hereinafter referred to as a conjugated diolefin polymer) having terminal modified groups at both ends of the present invention is prepared in a hydrocarbon solvent. After reacting alkyl monolithium with a specific vinyl compound in advance, a conjugated diolefin monomer is polymerized or copolymerized to create a living rubber-like conjugated diolefin polymer with a modified group at one end. A method of introducing modified groups at both ends by reacting a vinyl compound with a coupling agent, and a method of introducing modified groups at both ends by reacting a coupling agent with the above-mentioned living rubber-like conjugated diolefin polymer having a modified group at one end. how to,
In addition, the living rubber-like conjugated diolefin polymer having a modified group at one end is reacted with the following compound, which has a specific atomic group in the molecule and a functional group that binds to the active lithium end. It can be obtained by a method of introducing a modified group at the terminal, and a combination or combination of the above methods. Furthermore, a conjugated diolefin monomer is polymerized using a dilithium catalyst in a hydrocarbon solvent, resulting in a rubbery conjugated diolefin polymer containing living lithium at both ends, which is then reacted with a specific vinyl compound to modify both ends. A method of introducing a group, and a method of introducing a group into the rubber-like conjugated diolefin polymer containing living lithium at both ends, which has a specific modified group, and has a functional group that binds to the living end, and has a functional group that binds to the living end. A method of introducing modified groups at both ends by reacting a compound with
and combinations and combinations thereof.

The conjugated diolefin used in the present invention includes: 1.
3-butadiene, isobre/, 1,3-pentadiene,
Includes 2,3-methyl-1,3-butadiene, 1,3-hexadiene, etc., preferably 1,3-butadiene,
It is implen. The vinyl aromatic compound used in the present invention includes styrene, α-methylstyrene, vinyltoluene, vinylnaphthalene, divinylbenzene, trivinylbenzene, divinylnaphthalene, etc., with styrene being preferred.

The terminal modifying groups to be introduced at both ends of the polymer of the present invention are selected from Groups (1), (V), and (2) of the periodic table, and have electronegativity of the formula 0.41≦ and ≦0.6O. (wherein, Xp represents the electronegativity of the atom, and N represents the periodic table group number of the atom).

Here, Xp is the electronegativity of the atom, and in the present invention, Pauling's electronegativity (Chemistry Handbook Basic Edition Revised 2nd Edition, 128
8 pages, published by Maruzen Co., Ltd.). N is the group number of the atom in the periodic table. Atoms that satisfy such requirements include nitrogen, oxygen, silicon, phosphorus, sulfur, germanium, tin, and lead. As an atomic group containing at least one of these atoms, as a nitrogen-containing atomic group, -Nζ
Biji (R1, R2 are hydrogen or substituents), = N-R1
(Rt is hydrogen or a substituent), -CmiN, -N=C=0,
-0-C”:N.

-8-CEN, -N=C=8゜-N20, etc., and the oxygen-containing atomic group is -8-0-R1
(R1 is hydrogen or a Ut substituent), -〇-R,, (R1 is hydrogen or a substituent), etc., and the sulfur-containing atomic group is
-8-R, (R is hydrogen or a substituent), etc., and examples of phosphorus-containing atomic groups include groups), and examples of silicon-, germanium-, tin-, and lead-containing atomic groups include -MX, - MX2R1, -MX(R1)2, -M(R
1) 3 (M is either 5iXGe, Sn, Pb, X is a substituent such as alkyl, aryl, etc.) Even if these atomic groups are adjacent to each other, Alternatively, two or more may be present in the same terminal modified group.

The specific vinyl compound for introducing the terminal modified group of the present invention into the conjugated diolefin polymer is a vinyl compound having the above-mentioned atomic group, and among these, a vinyl compound containing a tertiary amino group is particularly preferable. It is.

As the tertiary amine group-containing vinyl compound, general formula a, R
R2 is a compound selected from C1 to □8 alkyl, arylalkyl, aryl group), general formula (m = integer from 1 to 3, R1, R,, U same as above) and a hyal pyridine derivative, for example,
p-dimethylaminostyrene, p-diethylaminostyrene, p-dimethylaminomethylstyrene, p (2-
dimethylaminoethyl)styrene, m-(2-dimethylaminoethyl)styrene, p-(2-diethylamineethyl)styrene, I) (2” methylaminovinyl)
Examples include styrene, p-(2-diethylamino-nyl)styrene, 2-vinylpyridine, 4-vinylpyridine, 2-vinyl-5-etherpyridine, etc. Preferably p-(2-diethylamino-nyl)styrene,
-dimethylaminoethyl)styrene is used.

When introducing a terminal modified group by reacting the active lithium terminal with these specific vinyl compounds, an average of 10 moles or less, preferably 6 moles or less, and more preferably 1 to 4 moles of the terminal modified group are introduced per one terminal.

If there are more terminal modified groups than this, the heat generation property and impact resilience will be poor;
Furthermore, if the number of terminal groups is small, the effects of heat generation and impact resilience will be reduced.

In order to introduce the terminal modified group of the present invention into the conjugated diolefin polymer, in the compound having a specific atomic group and a functional group bonding to the active lithium terminal, the specific atomic group is selected from Group Ⅰ, Group V and Group Ⅰ of the Table of Laws, and whose electronegativity is according to the formula 0.41μ<0.60 (wherein,
Xp is the electronegativity of the atom, N is the periodic table group number of the atom). 'l The functional group bonded to the IJ thiium terminal is '::C=0. 7=8. ≧C=,N
-R1 (R.

: substituent) M-X (M: P, Si, Ge
, Sm5PJX: halogen, alkoxy, aryl,
benzyl group), etc. Among these, compounds having a medium-pressure tertiary amino group and a carbonyl group or a thiocarbonyl group, carbodiimides with the general formula (R1)z (几2)mS? t: X (R1, R2
indicates an alkyl, aryl, or alkoxy group;
rogen, t+m=3 L=O or an integer from 1 to 3, m
= 0 or an integer of 1 to 3 tin compounds, compounds having a thioether group and a carbonyl or thiocarbonyl group are preferred.

Compounds having a tertiary amine group and a carbonyl group or thiocarbonyl group in the molecule include the general formula (M is O or S,
m = integer from 1 to 3, R1, R2 (M is O or S, n =
An integer of 0 to 6, 几1, R2 is 01 to . 8 alkyl, arylalkyl, aryl group), general formula R, R2 is C□-□8 alkyl, arylalkyl, aryl group), general formula R, R2 is C□-□ 8 alkyl, arylalkyl, aryl group), a compound having the general formula -C-R3 (M
is O or S, R3 is an atomic group containing a tertiary amino group, a pyridyl group, a quinolyl group, etc.), and these are, for example, N,N-dimethyl 7-olamide, N,N-
Diethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethyl-N', N'-dimethylaminoacetamide, N,N-
Dimethylacrylamide, NeN-dimethylmethacrylamide, N,N-diethylacetamide, N,N-dimethylbenzamide, N,N-dimethyl-N',N'-(
p-dimethylamino)benzamide, N,N-dimethylthioformamide, N,N,N',N'-tetramethylurea, N,N,N',N'-tetramethylthiourea,
N,N'-dimethylethyleneurea, N-ethyl-N-methyl-8-quinolinecarboxamide, N,N-dimethylnicotinamide, N,N-dimethyl-4-pyridylamide, N,N-dimethylmethacrylamide, N-methyl-ε-caprolactam, N-methyl-δ-parerolactam, N-methyl-γ-butyrolactam, N-)fk-β
-Propiolactam, N, N, N', N'-tetramethylmaleic acid amide, N, N, N', N'-tetramethylphthalamide, N-methylsuccimide, N-methylphthalimide, 10-acetyl Phenoxazine, 3.
7-bis(diethylamino)-10-benzoylphenoxazine, lO-acetylphenothiazine, 3.7-
Bis(dimethylamino)-10-benzoylfetchacycin, N,N-ethyl diethylcarbamate, N,N-
Dimethyl-N', N-(p-diethylamino)benzalacetamide, N,N-dimethyl-N', N'-(
p-dimethylamino) cinnamylidene acetoand, N
, N-dimethyl-N', N'-(2-dimethylamino)
vinylamide, p-dimethylaminobenzophenone, 4
．． 4'-bis(dimethylamino)benzophenone, 4.
4'-bis(diethylamino)benzophenone, p-dimethylaminobenzaldehyde, p-dimethylaminoacetophenone, p-(2-dimethylaminoethyl)aceto7dinone, '4.4'=bis(2-diethylaminoethyl)benzophenone, 4.4'-bis(3-dimethylaminepropyl)benzophenone, p(2-dimethylaminoethyl)benzaldehyde, 4.4'-bis(2-dimethylaminovinyl)benzophenone, p-(
2-dimethylaminovinyl)acetophenone, p-dimethylaminobenzalacetone, p-dimethylaminobenzalacetone, p-dimethylaminobenzalacetophenone, N,N-(p-dimethylamino)cinnamoyl-N',N'- (p-dimethylamino)benzene, N,
N-(p-dimethylamino)cinnamoyl-N', N'
-(2-dimethylamino)ethylene, 1,3-bis(4
'-dimethylaminobenzal)a7):/, 2.6-bis(4'-dimethylaminobenzal)cyclohexanone, p-dimethylaminocinnamylideneacetone, p-diethylaminocinnamylideneacetophenone, 4 (
p-dimethylaminophenyl)-1,a-butadienyl-N:N'(pI-dimethylamino)phenylketone,
3,3-bis(p-dimethylaminophenyl)phthalide, 3-diethylamino-6-methylfluorane, 3-diethylamino-6-methyl-7-anilinoflu terpene,
3,6-bis(diethylamino)fluorane-γ-anilinolactam, 2-(p-pyridyl)vinylmethylketone, 2-(4'-(2',6'-dimethyl)hyridyl]vinylmethylketone, 2- (p-pyridyl)vinyl-
N', N'-(p'-dimethylamino)phenylketone, 2-(o-pyridyl)vinylmethylketone, 4-
Acetylpyridine, 2-acetylpyridine, 4-benzoylpyridine, 2-benzoylpyridine, 4-(p'-
dimethylaminobenzoyl)pyridine, methyl 4-pyridinecarboxylate, methyl 2-pyridinecarboxylate, 4.
4'-dipyridyl ketone, N, N, N', N'-tetramethylthiuram monosulfide, N, N, N', N'-
Tetrabutylthiuram disulfide, N, N,
Examples include N', N'-pentamethylenethiuram tetrasulfide.

Carbodiimides include compounds having the general formula -N=C=N- bond, including dialkylcarbodiimide, alkylarylcarbodiimide, and diarylcarbodiimide, such as dimethylcarbodiimide, diethylcarbodiimide, diarylcarbodiimide, dibutylcarbodiimide, and diarylcarbodiimide. Examples include carbodiimide, dicyclohexylcarbodiimide, dibenzylcarbodiimide, diphenylcarbodiimide, methylpropylcarbodiimide, butylcyclohexylcarbodiimide, ethylbenzylcarbodiimide, propylphenylcarbodiimide, and phenylbenzylcarbodiimide.

Examples of the tin compound with the general formula (Rs)t (Rs)m SN Examples include phenyldimethyltin chloride, butyldiphenyltin chloride, and benzyldiphenyltin chloride.

Compounds having a thioether group and a carbonyl or thiocarbonyl group include thiodipropionate esters, alkylthiopropionate esters, dialkyl dixanthogen compounds, and examples include distearyl thiodipropionate, myristyl thiodipropionate, thiodipropionate, and thiodipropionate. Examples include silacryl propionate, ethyl laurylthiopropionate, diisobrobil dixanthate, and diethyl dixanthate.

When reacting a good compound with an active lithium terminal and a functional period that has a specific atomic group and is bonded to the active lithium terminal, the compound is used in an amount of 0.5 mol or more, preferably 0.65 mol or more relative to the active lithium. ~1.2 mol is used.

Coupling agents include tin, silicon, germanium polyhalogen compounds, polyvinyl compounds, polyallyl compounds, polyphenyl compounds, polybenzyl compounds, polyalkoxy compounds, etc. For example, tin tetrachloride,
Silicon tetrachloride, germanium tetrachloride, tin tetrabromide, silicon tetrabromide, methyltin trichloride, ethyltin trichloride, butyltin trichloride, methylsilicon trichloride, dimethyltin dichloride, dibutyltin dichloride, dimethylsilicon dichloride, tetravinyl Examples include tin, butyltri and nyltin, tetraallyltin, tetraphenyltin, triphenyltin chloride, tetrabenzyltin, tetra-silicon, and tetramethoxysilicon. Preferably, tin tetrachloride, methyltin trichloride, and diptyltin dichloride are used.

These coupling agents have a 0.5
More than the required amount is used, preferably 0.65 to 1.2 equivalents.

Furthermore, a method for introducing a modifying group into the end of these lipping polymers can also be combined and used together.

In that case, when a specific vinyl compound is reacted, it still becomes a living end after the reaction, and when a coupling agent is reacted, or when the molecule has a specific atomic group,
The living end may be terminated after the reaction, such as when reacting with a compound that has a functional group that binds to the active lithium end, and in these combinations, the modified group can be efficiently added to one end It is important to react in such a manner that 1 mole or more, and an average of 10 moles or less, are bonded for the effects of rebound and exothermic properties.In addition, it is important to leave as little unreacted compound as possible, and from a cost perspective, tensile It is also necessary from performance aspects such as strength, modulus, and hardness.

Hydrocarbon solvents used in the present invention include n-butane, n-pentane, 1ao-pentane, n-hexane, n-
-heptane, 1so-octane, cyclohexane, methylcyclopentane, benzene, toluene, etc. Particularly preferred solvents are n-hexane, n-hebutane, and cyclohexane. These hydrocarbon solvents may be used alone or in combination of two or more kinds, and are usually used in an amount of 1 to 20 parts by weight per part by weight of the monomer.

Examples of alkyl monolithium catalysts include hydrocarbons with l lithium atoms bonded to them, such as ethyllithium,
Examples include propyllithium, n-butyllithium, 5eC-butyllithium, tert-butyllithium, phenyllithium, perobenyllithium, and hexyllithium, with n-butyllithium being particularly preferred! 3ec-
Butyllithium. This alkyl monolithium catalyst can be used not only as 1fffl but also as a mixture of two or more types. The amount of the alkyl monolithium catalyst used depends on the Mooney viscosity of the produced polymer, but is usually 0.3 to 3 mmol, preferably 0.5 to 1.5 mmol, per 1007 monomers.

As the dilithium catalyst used in the present invention, there are roughly three types known depending on the manufacturing method. Namely, these are reactions between metallic lithium and dihalogen compounds, reactions between metallic lithium and diolefins, and reactions between organolithium and aromatic hydrocarbons containing disubstituted vinyl groups or alkenyl groups. In any case, as a dilithium catalyst, it is necessary that the monolithium portion is small, preferably the purity of the dilithium catalyst component is 90 mole or more, and that the initiation rate of both lithium atoms is substantially the same as the dilithium catalyst. . In this regard, a dilithium catalyst formed by the reaction of organolithium with an aromatic hydrocarbon containing a disubstituted vinyl group or an alkenyl group is preferred. More preferably, JP-A-58-136603
This is the method according to the publication. The amount of dilithium catalyst used is
It depends on the Mooney viscosity of the produced polymer, but usually the monomer is 10
0.4 #66 ml per 02, preferably 0.8-3
Millimoles.

In the conjugated diolefin rubber of the present invention, the vinyl aromatic compound is used in an amount of 0 to 50% by weight in the monomer, and if it exceeds 50% by weight, the heat generation of the vulcanized rubber is poor. On the other hand, if the amount of vinyl aromatic compounds is small, the tensile strength of the vulcanized rubber will be low.
Preferably it is 5 to 45% by weight.

The vinyl bond of the conjugated diolefin part of the conjugated diolefin rubber used in the present invention is preferably 1O to 75q
6, more preferably 15 to 50 inches.

Less vinyl bonding means less wet skid resistance;
On the other hand, if the vinyl bond is high, the abrasion resistance is low. ) and number average molecular weight (
Mw/
Rh) is 2.2 or less, preferably 1.2 to 2.0
The range is more preferably 1.3 to 1.8.

If the molecular weight distribution is larger than 2.2, the impact resilience and heat generation properties will be poor, and if the molecular iZ distribution is small, the processability will be reduced.

The molecular weight distribution determined by GPC may have one peak or two peaks. Generally, processability can be improved by coupling with a branching agent having three or more branches.

When the conjugated diolefin rubber used in the present invention is a copolymer of a conjugated diolefin and a vinyl aromatic, a random copolymer is preferable. A Lewis base can also be used as a randomizing agent if necessary. Randomizing agents include ethers such as tetrahydrofuran, diethylene glycol dimethyl ether, diethylene glycol dibutyl ether, amines such as triethylamine and tetramethylethylenediamine, thioethers, phosphines, phosphoramides, alkylbenzene sulfonates, potassium and sodium alkoxides. etc. 1. The vinyl aromatic chain distribution, which is a measure of the randomness of a copolymer of a conjugated diolefin and a vinyl aromatic compound, is analyzed by GPC of a low-temperature ozonolyzed product of the copolymer rubber. This method was developed by China et al.
The chain distribution of vinyl aromatic compounds is 2 in conjugated diolefins.
The decomposition product obtained by ozone cleavage of all the heavy bonds is analyzed by GPCK (Macromolecules, 19
83,16.1925)0 The copolymers used in the present invention are isolated vinyl aromatic compounds analyzed by this method,
That is, the vinyl aromatic compound having a chain of 1 vinyl aromatic compound unit is preferably 40% by weight or more, more preferably 50% by weight or more of the total vinyl aromatic compound, and the long chain vinyl aromatic compound block, that is, the vinyl aromatic The vinyl aromatic compound having a chain of 8 or more group compound units is preferably 5% by weight or less of the total vinyl aromatic compound, and more preferably 2.5% by weight or less. Even if the isolated vinyl aromatic compound is less than 40% by weight or the long chain vinyl aromatic compound block is more than 5 times, the excellent properties of the composition of the present invention, such as the high impact resilience and The balance between low heat build-up and high wet skid resistance is unfavorable.

The Mooney viscosity of the rubber-like conjugated diolefin polymer having modified groups at both ends of the present invention is ML□1004″15~1
50 is preferable, and 20-130 is more preferable.

If the Mooney viscosity is lower than this, the tensile strength, abrasion resistance, rebound, and heat generation properties of the vulcanized rubber will be poor; if the Mooney viscosity is higher than this, the processability will be poor, and excessive torque will be generated when kneading with rolls or Banbury. Otherwise, the performance of the vulcanized rubber is poor due to poor dispersion of carbon.

The specific conjugated diolefin rubber having modified groups at both ends of the present invention can be used alone or in a blend with other rubbers.

When used in a blend with other rubbers, the specific conjugated diolefin rubber of the present invention having modified groups at both ends is used in an amount of 10% by weight or more based on the raw material rubber. If it is less than 10% by weight, the balance between high impact resilience, low heat build-up and high wet skid resistance, which are the excellent properties of the composition of the present invention, will deteriorate.

Other rubbers that can be used with the specific conjugated diolefin rubber having modified groups at both ends of the present invention include natural rubber, synthetic cis-polyinprene, styrene-butadiene copolymer rubber, and polybutadiene rubber. Includes various diene rubbers that are sulfurized.

The specific conjugated diolefin rubber of the present invention having modified groups at both ends can be used alone or blended with curved rubber to form a composition suitable for tire treads comprising carbon black, a vulcanizing agent, and a vulcanization accelerator. .

The amount of carbon black used to create the specific conjugated diolefin rubber composition of the present invention is 10-100 parts by weight of carbon black per 100 parts by weight of raw material rubber.
Parts by weight are used. If it is less than 10 parts by weight, the tensile strength, abrasion resistance, etc. will not be sufficient, and if it exceeds 100 parts by weight, the rubber elasticity will be significantly lowered, which is not preferable. Preferably, it is 20 to 80 high resolution parts.

The type of carbon black used in preparing the specific conjugated diolefin rubber composition of the present invention preferably has an iodine adsorption f (IA) of 60 wq/y or more and a dibutyl phthalate oil absorption 1 (DBP) of 80 rnl/10.
Carbon black of 0F or higher is used. Such carbon black has a small particle size and no structure, and other carbon blacks may not provide the high balance of high tensile strength, high rebound resilience, and abrasion resistance of the present invention. . Preferably, the IA is soV/7 or higher and the DBP is 100 mj! /1.001 or more carbon black. Examples of these carbon blacks include those called HAF, 15AF, and SAF.

In preparing the specific conjugated diene rubber composition of the present invention, 0.3 to 5 parts by weight of sulfur is used as a vulcanizing agent based on 100 parts by weight of the raw rubber. If the sulfur content is too low, tensile strength, rebound resilience, and abrasion resistance will be insufficient, and if it is too high, the rubber elasticity will decrease. In preparing the specific conjugated diene rubber composition of the present invention, the amount is preferably 0.5 to 2.5 parts by weight, various conventionally known vulcanization accelerators can be used as the vulcanization accelerator. However, preferably a thiazole-based vulcanization accelerator is used. What is thiazole-based vulcanization accelerator?R'
It is a vulcanization accelerator whose basic structure is N'C-8-(Rnia\S/rukylene, arylene) group. With these vulcanization accelerators, the excellent tensile strength, rebound properties, and abrasion resistance of the present invention can be obtained, but with other accelerators, proper vulcanization may not be obtained. These vulcanization accelerators are preferably vulcanization accelerator M (2-mercaptobenzothiazole), vulcanization accelerator DM (dibenzothiazyl disulfide)''), vulcanization accelerator CZ (N- 7
chlorhexyl-2-benzothiazylsulfenamide)
There is.

The amount of vulcanization accelerator used is preferably 0.2 to 3 parts per 100 parts of rubber.

The composition using the specific conjugated diene rubber of the present invention includes:
Process oils commonly used for rubber compounding are used depending on the purpose and application. They are divided into paraffinic, naphthenic, and aromatic based on their chemical structure. For applications where tensile strength and abrasion resistance are important, aromatic and tsuku-based are used, while naphthenic and paraffinic are used for applications where rebound resilience and low-temperature properties are important. are preferably used. The amount is 5 parts by weight per 100 parts by weight of raw rubber.
-100 parts by weight is suitable; if it is less than 5 parts by weight, the processability is poor and the dispersion of carbon black is poor, so properties such as tensile strength and elongation are not expressed, and if it exceeds -1100 parts by weight, tensile strength, This is undesirable because it causes a significant decrease in rebound resilience and hardness.

When the specific conjugated diene rubber composition of the present invention is used, fillers other than carbon black, zinc oxide, stearic acid, antioxidants, antiozonants, wax, etc. may be added as necessary. be able to.

In addition, fillers other than carbon black include silicic acid,
Silicates, calcium carbonate, titanium oxide, various clays, etc. are used.

The copolymer rubber composition of the present invention is obtained by kneading the above-mentioned components using a mixer known for use in the rubber industry, such as an open roll or an internal mixer, by various known methods. Rubber products obtained through the vulcanization process exhibit superior performance compared to rubber products obtained from conventionally known rubber compositions. Among them, it exhibits high impact resilience under special pressure, low heat generation, tensile strength, and wet skid property. Therefore, ``normal conjugated diolefin polymer,
It is used in applications where a composition of a conjugated diolefin-vinyl aromatic compound copolymer is used, and is particularly preferably used for tire treads.

〔Example〕

These are specifically shown and are not intended to limit the scope of the present invention.

Example 1 50-cyclohexane containing 0.52 f of n-butyllithium was placed in a nitrogen-substituted glass bottle with a rubber stopper and had an internal volume of 300 fnt, and 3.55 f was added to the bottle while stirring at room temperature.
of p-(2-dimethylamineethyl)styrene (for i
2.5 mol per unit) was gradually injected over about 15 minutes, and 1
The mixture was stirred and reacted at room temperature for an hour.

45 cyclohexane was added to a reactor with an internal volume of 10 tons and equipped with a stirrer.
98f, purified butadiene 7801, purified styrene 1
After charging 62 t and 382 t of tetrahydrofuran and maintaining the temperature at 40°C, the previously prepared n-butyllithium and p-(2-dimethylaminoethyl)styrene were injected to start polymerization. The polymerization temperature was increased. From the moment the internal temperature reaches 75'GK', 138$'
of butadiene and 322y of cyclohexane were added using a metering pump over a period of 17 minutes for 10 minutes, and 1 minute after the end of the addition, 92.5 mol/i of p-(2-dimethylaminoethyl)styrene C was added to 3.55 f of p-(2-dimethylaminoethyl)styrene C. Add
The reaction was continued for an additional 20 minutes. Thereafter, 81 BHT (2,6-di-1-butyl-4) was added to the polymer solution as an antioxidant.
- After adding methylphenol, remove the solvent by heating,
The polymer was recovered. The obtained polymer had a Mooney viscosity (ML1+4100°C) of 25, a styrene content of 15% by weight, and a microstructure of the butadiene moiety: 32% of 1,4-trans bonds, 22% of l,4cis bonds, and 112-vinyl. The binding was 46%.

In addition, the molecular weight distribution Mw/Mn obtained from this combination GPC (Kölpermeation chromatography)
= 1.3, indicating that the GPC curve had one peak.

The styrene content and the microstructure of the butadiene moiety were determined by measuring the engineering R spectrum and calculating by Hampton's method. Mw/Mn is G, P, C.

(Ro Ri Seisakusho, LC-aA, Kara A to',
to', 1o'.

It was determined by calculation using a calibration curve using polystyrene as a standard substance.

Further, the isolated styrene determined by GPC,l of the ozone decomposed product was 68% by weight based on the total styrene, and the long chain block styrene was 0.3% by weight.

Next, using this polymer as a raw material rubber and using a Banbury mixer for testing with an internal capacity of 1.7 L, according to method B of the standard mixing procedure of ASTM-D-3403-75, with the formulation shown in Table 1. , a mixture was obtained, these were vulcanized, and each physical property was measured. The measurements were performed using the method shown below.

(1) Hardness and tensile strength: According to JIS-6301.

(2) Repulsion: Luebke method according to JIS-6301. However, the repulsion at 70°C is as follows:
After preheating in the oven for 1 hour, quickly remove and measure.

(3) Using a Gutdrich heat generating Gutdrich flexmeter, the test was conducted under the conditions of 50°C and 180 rpm (load: 48 bonds, displacement: 0.225 inch, star), and the difference in temperature rise after 20 minutes was expressed. .

(4100°C) Wet skid resistance Using a Stansy London portaple skid tester and using Safety Walk (manufactured by 3M) as the road surface,
It was measured according to the method of STM-E-808-74. 5B
It was expressed as an index with the measured value of R1502 set as 100.

The measurement results are shown in Table-2.

Example 2 In the same manner as in Example 1, a living copolymer rubber having a modified group bonded to one end was obtained, and then 0.9272 N, N ′−
Dimethylethylene urea (1 mol/i) was added and the polymer was recovered in the same manner. The obtained polymer had a Mooney viscosity (ML144) of 28 and a styrene content of 15% by weight.
The microstructure of the butadiene moiety was 33% 4-trans bonds, 22% 1,4-cis bonds, and 45 1,2-vinyl bonds.

Also, Mw/Mn = 1, 4, and GP
The curve C had one peak. In addition, the ozone decomposition product (isolated styrene determined by 3PC is 65% by weight based on the total styrene, and long chain block styrene is 0.9% by weight.
It was 5% by weight. It was blended and vulcanized in the same manner as in Example 1, and its performance was measured. The results are shown in Table-2.

Example 3 In the same manner as in Example 1, a living copolymer rubber having a modifying group bonded to one end was obtained, and then 0.159F tin tetrachloride (0.3 equivalent for i) was fully quenched. , 1 minute later, 1 more.
539 of 4,4'-bis(dimethylamino)benzophenone (0.7 mol per 1 mol) was processed, and chilimer was recovered in the same manner. The obtained polymer had a Mooney viscosity (ML1 dimension C4C = 55, styrene content 15% by weight, microstructure of the butadiene moiety, 1.4-trans bond 32%,
(2) 21% of 4-cis bonds and 47% of 1,2-vinyl bonds. In addition, Mw/Mn was 1.6, indicating that the GPC curve had two peaks.Also, the isolated styrene determined by GPC of the ozone decomposed product was 68% by weight based on the total styrene. The content of long-chain blocked styrene was 0.5% by weight.It was oriented and vulcanized in the same manner as in Example 1, and its performance was measured.The results are shown in Table 2.

Example 4 A product was prepared by the method of Example 1 of JP-A-58-136603.

45 cyclohexane was added to a reactor equipped with a stirrer with an internal volume of 10t.
98 F, Refined Getashev '180? , purified styrene 162? After charging 38 fft of tetrahydrofuran and maintaining the temperature at 40°C, the previously prepared cyclohexane solution of dilithium catalyst was added to 2.32 fft of dilithium catalyst.
The entire amount equivalent to f was injected to initiate polymerization, and thereafter the polymerization temperature was raised adiabatically. 1 from the time the internal temperature reaches 75℃
A mixture of 381 getadiene and 322f cyclohexane was added over 10 minutes using a metering pump, and 1 minute after the addition was complete, 2.0'l of N-methyl-C-caprolactam (1.0 mol/i) was added to the total The mixture was added and reacted for an additional 20 minutes. Thereafter, 82 BHT was added as an antioxidant to the polymer solution, and then the solvent was removed by heating and the polymer was recovered. The obtained polymer has a Mooney viscosity < ML
, 1:04'C) is 30, styrene content 15% by weight,
The microstructure of the butadiene moiety is 32% of 1.4-trans bonds, 22% of 1.4-cis bonds, 7t of 1,2-pini bonds,
The bond was 46chi. Further, it was shown that when MW/Nln=1.3, the p and GPC curves had one peak. Furthermore, the amount of isolated styrene determined by GPC of the ozone-decomposed product was 65% by weight based on the total styrene, and the amount of long-chain block styrene was 0.5% by weight. It was blended and vulcanized in the same manner as in Example 1, and its performance was measured. The results are shown in Table-2.

Example 5 In the same manner as in Example 4, a living copolymer rubber at both ends was obtained using a dilithium catalyst, and 4,4'-bis(dimethylamino)benzophenone (4.361) was used instead of N-methyl-ε-caprolactam. 1.0 mol per i) is added to the
Polymer was recovered in the same manner.

The obtained polymer had a Mooney viscosity (ML t”:”) of 3.
2. Containing styrene 1it 15% by weight, the microstructure of the butadiene moiety is 1,4-trans bond 32ti, I, 4-
The content was 21% for cis bonds and 47% for 1,2-vinyl bonds.

Furthermore, Mw/Mn = 1.3, indicating that the GPC curve had one peak. Also, GP of ozone decomposition product
The isolated styrene determined from C was 65% by weight based on the total styrene, and the long chain block styrene was O, S weight%. It was blended and vulcanized in the same manner as in Example 1, and its performance was measured.゛The results are shown in Table-2.

Example 6 In the same manner as in Example 4, a living copolymer rubber at both ends was obtained using a dilithium catalyst, and 7.10f of p-(2-dimethylaminoethyl)styrene (as opposed to N-methyl-C-caprolactam) was used instead of N-methyl-C-caprolactam. 2.5 mol/i) was added, and the polymer was recovered in the same manner. The obtained polymer has a Mooney viscosity (
"t+<) is 35, styrene content is 15% by weight, butadiene moiety microstructure is 1.4 trans bond 32%
, 1.4-cis bond 21 Z, L2-vinyl, bond 47
It was Chi.

Further, Mw/Mn = 1.4, indicating that the GPC curve had one peak. Also, GP of ozone decomposition product
The isolated styrene determined from C was 65% by weight based on the total styrene, and the long chain block styrene was 0.5% by weight. It was blended and vulcanized in the same manner as in Example 1, and its performance was measured. The results are shown in Table-2.

Example 7 In the same manner as in Example 4, a living copolymer rubber at both ends was obtained using a dilithium catalyst, and instead of N-methyl-C-caprolactam, 3.35 f of N,N'cyclohexylcarbodiimide (1. 0 mol) was added, and the polymer was recovered in the same manner. The obtained polymer has a Mooney viscosity (ML
1+4) is 32, styrene content is 15% by weight, and the microstructure of the butadiene moiety is 1.4-trans bond 32
21% of 1,4-cis bonds and 47 L2-vinyl bonds. Moreover, Mw 7Mn=1.3, indicating that the GPC curve had one peak. Further, the amount of isolated styrene determined by GPC of the ozone decomposed product was 65% by weight based on the total styrene, and the amount of long chain block styrene was 0.5% by weight. It was blended and vulcanized in the same manner as in Example 1, and its performance was measured. The results are shown in Table-2.

Example 8 In the same manner as in Example 4, a living copolymer rubber at both ends was obtained using a dilithium catalyst, and instead of N-methyl-ε-caprolactam, 4.26 f of 4-vinyl pyridine (for i and 2.5 mol) was added, and the polymer was recovered in the same manner. The obtained polymer has a Mooney viscosity (MLl"+'4'c)
The microstructure of the butadiene moiety is 37, styrene-containing ils, 1.4
There were 21 -cis bonds and 47 1,2-vinyl bonds. Also, Mw/Mn = 1.4, which indicates that the GPC curve has one peak.

Isolated styrene determined by GPC of the secondary ozone decomposition product was 65% by weight based on the total styrene, and long chain block styrene was 0.5% by weight. Mixed in the same manner as in Example 1,
It was vulcanized and its performance was measured.

The results are shown in Table-2.

Example 9 In the same manner as in Example 4, a living copolymer rubber at both ends was obtained from the dilithium catalyst [τ, and K 6.25 ? ) Riphenyltin chloride (1.0 mol/i) was added, and the polymer was recovered in the same manner. The obtained polymer has a Mooney viscosity (ML1τ
7) is 37, styrene content is 15% by weight, and the microstructure of the butadiene moiety is 1.4-trans bond 32q6.1
, 21% of 4-cis bonds and 47% of 1,2-vinyl bonds. Also, Mw/Mn = 1.4, which indicates that the GPC curve has one peak. Also, GP of ozone decomposition product
The isolated styrene determined from C was 65% by weight based on the total styrene, and the long chain block styrene was 0.5% by weight. The mixture was blended and vulcanized in the same manner as in Example 1, and the performance was measured. The results are shown in Table-2.

Example 10 In the same manner as in Example 4, a living copolymer rubber at both ends of υ was obtained using a dilithium catalyst, and ethyl laurylthiopropionate of N-methyl-ε-caprolactam (F) VC4,9Of (for i equivalent) was obtained. , 91.0 mol) was added, and the polymer was recovered in the same manner. The obtained polymer has a Mooney viscosity (ML
1% by weight) is 38, contains styrene! 15% by weight, the microstructure of the butadiene part is 1.4-) Lance bond 3
2-thi, 1,4-cis bond 21%, 1,2-vinyl bond 4
It was 7chi. Also, Mw/Mn=1.4, and GPC
The curve indicated that there was one peak. Further, the amount of isolated styrene determined by GPC of the ozone decomposed product was 65% by weight based on the total styrene, and the amount of long chain block styrene was 0.5% by weight. It was blended and vulcanized in the same manner as in Example 1, and its performance was measured. The results are shown in Table-2.

Example 11 In the same manner as in Example 4, a living copolymer rubber at both ends was obtained using a dilithium catalyst, and 3.38f of N,N,N',N'-tetra was used instead of N-methyl-ε-caprolactam. Methylthiuram monosulfide (i/o mol)
was added, and the polymer was recovered in the same manner. The obtained polymer had a Mooney viscosity (ML□1%'C) of 36, a styrene content of 15% by weight, and a microstructure of the butadiene moiety.
1.4-) 32 lance bonds, 21 1.4-cis bonds, 1. Z-vinyl bond is 47% and fto and Mw/M
n=t, 3, indicating that the GPC curve had one peak. Further, the amount of isolated styrene determined by GPC of the ozone decomposed product was 65% by weight based on the total styrene, and the amount of long chain block styrene was 0.5% by weight. Compounding and vulcanization were carried out in the same manner as in Example 1, and all performance measurements were carried out. The results are in the table-
Shown in 2.

Comparative Example 1 Cyclohexa 74
598f, refined pork chef 780? , Ill Styrene 1621. After charging tetrahydrofuran 382 and maintaining the temperature at 40° C., 0.52 f of n-butyllithium was injected to initiate polymerization, and the polymerization temperature was then raised adiabatically. From the moment the internal temperature reaches 75℃, 13
A mixture of 8F butadiene and 3222 7 chlorohexane was added using a metering pump over io minutes, and after the addition was complete, the reaction was continued for an additional 10 minutes, and then 8F was added to the polymer solution as an antioxidant. After adding BHT, the solvent was removed by heating,
The polymer was recovered. The obtained polymer has a Mooney viscosity (
ML□1°C) is 22, styrene content is 15% by weight, and the microstructure of the butadiene moiety is 1.4-trans bond 3
4th, 1,4-cis bond 23th, 1,2-vinyl bond 4
It was 3%. Also, Mw/Mn = 1.1, and G
The PC curve shows that there is one peak.Next. The isolated styrene determined by GPC of the t+t ozone decomposition product is 5% by weight based on the total styrene, and the long chain block styrene is 1% by weight based on the total styrene.
．． It was 3% by weight. Blended and vulcanized in the same manner as in Example 1,
Performance was measured. The results are shown in Table-2.

Comparative Example 2 After obtaining a living polymer in the same manner as Comparative Example 1, 3.55
p-(2-dimethylaminoethyl)styrene (2.5 mol per i) of f was added, and the reaction was further continued for 20 minutes.

Then, collect the polymer in the same way.

The obtained polymer had a Mooney viscosity (ML□10 (4″) of 361, X, fV content of 15% by weight, microstructure of the butadiene moiety of 1.4-), lance bonds of 32, 1,4
-cis bond was 21%, and 1.2-vinyl bond was 47q6. Also, Mw/Mn = 1, 3, and GP
The curve C had one peak. Furthermore, isolated styrene determined by GPC of the ozone decomposed product was 63% by weight based on the total styrene, and long chain block styrene was 0.5% by weight.
% by weight. It was blended and vulcanized in the same manner as in Example 1, and its performance was measured. The results are shown in Table-2.

Comparative Example 3 After obtaining a living polymer in the same manner as Comparative Example 2, p-(2
-dimethylamino-ethyl)styrene instead of 2.1
8F 4,4'-bis(dimethylamino)benzophenone (1 mole per i) was added and the polymer was recovered in the same manner. The obtained polymer had a Mooney viscosity (ML) of 28, a styrene content of 15% by weight, and a microstructure of the butadiene moiety of 32 units of 1,4-trans bonds, l
, 22% of 4-cis bonds, and 46% of 1,2-vinyl bonds. Further, Mw/Mn = 1.2, indicating that the GPC curve had one peak. Also, the amount of isolated styrene determined by GPC of the ozone decomposed product is 6% compared to the total styrene.
5% by weight, and long chain block styrene is 0.3% by weight.
Met. Compounding and vulcanization were carried out in the same manner as in the examples, and the performance was measured. The results are shown in Table-2.

Comparative Example 4 Emulsion polymerization 5BR-1502 was blended and vulcanized in the same manner as in Example 1, and its performance was measured. The results are shown in Table-2.

〔Effect of the invention〕

As mentioned above, the conjugated diolefin rubber according to the present invention has extremely good tensile strength, rebound resilience, and heat generation properties. The rubber and composition thereof of the present invention are particularly suitable for use in tire treads, and have great industrial significance.

Margin table below - 1 *1 Kyodo Oil Phenamide vulcanization conditions = 160°C x 20 minutes

Claims (1)

[Claims] 1) A conjugated diolefin polymer or a copolymer of a conjugated diolefin and a vinyl aromatic compound, which has a compound selected from Groups IV, V and VI of the periodic table at both ends of the polymer,
And reduce the number of atoms whose electronegativity falls within the range of the formula 0.41≦Xp/N≦0.60 (wherein, Xp is the electronegativity of the atom, and N indicates the periodic table group number of the atom). The molecular weight distribution (@M@w/@M@n) of the polymer or copolymer is 2.2 or less, and the Mooney viscosity (ML_1_+_4^1) ^0^0
A rubbery polymer having a temperature of 15 to 150