Sumitomo Chemical Company, Limited

Sumitomo Rubber Industries Limited

Tomoaki Seki

Akio Imai

Keisaku Yamamoto

Nobuyuki Yoshida

Yuichi Saito

Hiroshi Furukawa

Yasushi Okamoto

Hiroyoshi Takao

Mitsuji Tsuji

A process for preparing modified diene polymer rubbers having an increased impact resilience, a reduced hardness at low temperatures and an improved processability, and useful as rubber materials for automobile tires and other industries which comprises producing a conjugated diene polymer having alkali metal end or ends, and reacting the alkali metal-containing polymer with (a) a silicon or tin compound of the formula: R.sub.a MX.sub.b wherein R is an alkyl group, an alkenyl group, a cycloalkenyl group or an aromatic hydrocarbon atom, a is 0, 1 or 2 and b is 2, 3 or 4, and (b) at least one member selected from the group consisting of a nitro compound; a phosphoryl chloride compound of the formula (1): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are an alkyl group; an aminosilane compound of the formula (2): ##STR2## wherein R.sup.5, R.sup.6 and R.sup.7 are an alkyl group or an alkoxyl group, R.sup.8 and R.sup.9 are an alkyl group, and n is an integer; an acrylamide compound of the formula (3): ##STR3## wherein R.sup.10 is hydrogen atom or methyl group, R.sup.11 and R.sup.12 are an alkyl group, and m is an integer; and an aminovinylsilane compound of the formula (4): ##STR4## wherein R.sup.13, R.sup.14, R.sup.15, R.sup.16 and R.sup.17 are an alkyl group.

Modified diene polymer rubbers

A process for preparing modified diene polymer rubbers having an increased impact resilience and a reduced hardness at low temperatures and useful as rubber materials for automobile tires and other industries which comprises producing an alkali metal-containing conjugated diene polymer, and reacting the akali metal-containing polymer with an acrylamide modifier compound of the formula: ##STR1## wherein R.sup.1 is hydrogen atom or methyl group, R.sup.2 and R.sup.3 are independently an alkyl group and n is an integer said alkali metal-containing diene polymer being prepared by a living anionic polymerization using an alkali metal-based catalyst or by an addition reaction of a diene polymer having conjugated diene units and an alkali metal-based catalyst in a hydrocarbon solvent. The modified diene polymers can be incorporated with usual rubber additives and with or without other rubbers to provide rubber compositions for various purposes, and the cured products show an increased impact resilience and a reduced hardness at low temperatures.

A process for preparing modified diene polymer rubbers having an increased impact resilience, a reduced hardness at low temperatures and an improved processability, and useful as rubber materials for automobile tires and other industries which comprises producing a conjugated diene polymer having alkali metal end or ends, and reacting the alkali metal-containing polymer with (a) a silicon or tin compound of the formula: R.sub.a MX.sub.b wherein R is an alkyl group, an alkenyl group, a cycloalkenyl group or an aromatic hydrocarbon group, M is silicon atom or tin atom, X is a halogen atom, a is 0, 1 or 2 and b is 2, 3 or 4, and (b) at least one member selected from the group consisting of a nitro compound; a phosphoryl chloride compound of the formula (1): ##STR1## wherein R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are an alkyl group; an aminosilane compound of the formula (2): ##STR2## wherein R.sup.5, R.sup.6 and R.sup.7 are an alkyl group or an alkoxyl group, R.sup.8 and R.sup.9 are an alkyl group, and n is an integer; an acrylamide compound of the formula (3): ##STR3## wherein R.sup.10 is hydrogen atom or methyl group, R.sup.11 and R.sup.12 are an alkyl group, and m is an integer; and an aminovinylsilane compound of the formula (4): ##STR4## wherein R.sup.13, R.sup.14, R.sup.15, R.sup.16 and R.sup.17 are an alkyl group.

A process for preparing modified diene polymer rubbers having an increased impact resilience and a reduced hardness at low temperatures and useful as rubber materials for automobile tires and other industries which comprises producing an alkali metal-containing conjugated diene polymer, and reacting the alkali metal-containing polymer with a modifier selected from the group consisting of a nitro compound, a phosphoryl chloride compound of the formula: ##STR1## wherein R.sup.1 to R.sup.4 are independently an alkyl group, and an aminosilane compound of the formula: ##STR2## wherein R.sup.5 to R.sup.7 are independently an alkyl group or an alkoxyl group, R.sup.8 and R.sup.9 are independently an alkyl group, and n is an integer,

Process for preparing modified diene polymer rubbers

A process for preparing modified diene polymer rubbers having an increased impact resilience and a reduced hardness at low temperatures and useful as rubber materials for automobile tires and other industries which comprises producing an alkali metal-containing conjugated diene polymer, and reacting the alkali metal-containing polymer with a modifier selected from the group consisting of a nitroalkyl acrylate of the formula: ##STR1## wherein R.sup.1 and R.sup.2 are independently an alkyl group and n is an integer, and a nitroamino compound of the formula: ##STR2## wherein R.sup.3 to R.sup.6 are independently an alkyl group, and m is an integer, said alkali metal-containing diene polymer being prepared by a living anionic polymerization using an alkali metal-based catalyst or by an addition reaction of a diene polymer having conjugated diene units and an alkali metal-based catalyst in a hydrocarbon solvent. The modified diene polymers can be incorporated with usual rubber additives to provide rubber compositions for various purposes, and the cured products show an increased impact resilience and a reduced hardness at low temperatures.

A process for producing a thermoplastic elastomer comprising a block copolymer of the A-B-A' type, wherein A is a monovinyl aromatic hydrocarbon polymer block, B is a conjugated diolefin polymer block, and A' is either the same as A or a polymer block derived from a dialkenyl aromatic hydrocarbon or a dihalogenated hydrocarbon, which process comprises polymerizing a monovinyl aromatic hydrocarbon in a polymerization medium in the presence of an organomonolithium compound as a polymerization initiator, adding a conjugated diolefin to perform block copolymerization, and further adding a monovinyl aromatic hydrocarbon to perform polymerization or in the alternative, adding a dialkenyl aromatic hydrocarbon or a dihalogenated hydrocarbon to perform coupling, wherein the monomer components are used in such amounts that the weight ratio of (A+A') to B ranges from 10/90 to 65/35, and a chained aliphatic hydrocarbon solvent containing from 0.0001 to 0.1 wt % of a Lewis basic compound is used as the polymerization medium, is disclosed. According to the process of the invention, the desired thermoplastic elastomer having good physical properties is readily obtainable with high reproducibility.

Process for producing thermoplastic elastomers

An elastomeric copolymer of an aromatic vinyl compound and butadiene prepared by a solution polymerization method, which has a glass transition temperature of not less than -50.degree. C. and contains polymer chains modified with a trifunctional or tetrafunctional coupling agent, and which contains not less than 3% by weight to less than 23% by weight, based on the whole polymer chains, of polymer chains having a molecular weight of at least 5 times a molecular weight corresponding to a peak appearing on the low molecular weight side of a high performance liquid chromatogram of the elastomeric copolymer. The elastomeric copolymer has an excellent processability and shows a low rolling resistance and a high wet grip characteristic when used as a rubber component in tires.

Elastomeric copolymer of aromatic vinyl compounds and butadiene

A branched polymer which is a butadiene homopolymer or a copolymer of an aromatic vinyl compound and butadiene and has a glass transition temperature of not less than -50.degree. C. and of which at least 70% by weight of the polymer chains has a branched structure in which high molecules are coupled by a trifunctional or tetrafunctional coupling agent, has an excellent roll processability as required in mixing a rubber component with additives and provides a rubber component for tire tread showing a low rolling resistance and an excellent wet skid resistance characteristic.

Branched polymer, process for the preparation thereof, tire tread rubber

A rubber composition containing an isoprene homopolymer or copolymer having a glass transition temperature of not less than -50.degree. C. and a Mooney viscosity of 20 to 120. The composition can provide a cured rubber having a high wet road gripping force and a small dynamic heat generating characteristic, and is very suitable for use in tires of automobiles.

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Ichihara, Japan

Tomoaki Seki