Sumitomo Chemical Company, Limited

Sumitomo Rubber Industries Limited

Toyoda Goesi Co., Ltd.

Keisaku Yamamoto

Akio Imai

Kizuku Wakatsuki

Masahiro Fukuyama

Yuichi Saito

Nobuyuki Yoshida

Yoshio Tanimoto

Kiyoshi Ikeda

Hayato Saba

Hiroshi Furukawa

Tomoaki Seki

Kiyoyuki Sugimori

Mitsuji Tsuji

Nobuhiro Natsuyama

Hideaki Yamada

Kiyosi Ikeda

Yasushi Okamoto

Hiroyoshi Takao

Hirofumi Johoji

Hidetake Hozumi

Tadaaki Nishiyama

Noriyasu Yasuda

Takashi Sanada

Masanori Aritake

Katsunari Inagaki

Hiroyuki Harada

Yuji Kobayashi

Takeshi Naito

Sumio Hara

Toru Fukumoto

Junichi Koshiba

Kohichi Iketani

Minoru Takane

Eiichi Usuda

Shuji Imaoka

Masahiro Ichinose

Mashiro Fukuyama

Daizaburo Imai

Masatoshi Ogura

Akio Okumura

Isao Takano

A propylene copolymer comprising propylene, at least one olefin selected from the group consisting of olefins having 2 to 20 carbon atoms except propylene, and a cyclic olefin, wherein the total number of carbon atoms of the monomers except the cyclic olefin is at least 7. This copolymer is mixed with a thermoplastic resin such as polypropylene to provide a thermoplastic resin composition having excellent flexibility, transparency, resistance to whitening on bending, scratch resistance and heat resistance.

Propylenic copolymer and thermoplastic resin composition

A propylene copolymer obtainable by polymerizing a propylene, at least one of .alpha.-olefin having 4-20 carbon atoms, and ethylene, in the presence of a catalyst for olefin polymerizaton including the following (A), (B) and/or (C):

Propylene copolymer

A rubber composition obtained by kneading a mixture comprising 100 parts by weight of a solution polymerized diene rubber, 5-100 parts by weight of silica, 1-15 parts by weight of a silane coupling agent, and 1-20 parts by weight of an organic silicon compound having a number average molecular weight of about 100-10,000, and maintaining the temperature during the kneading at 200.degree. C. or less. The composition is excellent in wear resistance and productivity, has lower rolling resistance and is useful, for example, for automobile tires.

Rubber composition

Provided is a rubber composition obtainable by kneading a mixture at a maximum temperature between about 120.degree. to about 170.degree. C. The mixture includes:

A composition is disclosed which contains about 80.0 to about 99.9% by weight of a (meth)acrylate monomer having a structure represented by a formula (I) or a mixture of the (meth)acrylate monomer and alkyl acrylate having an alkyl ester comprising alcohol of 1 to 8 carbon atoms, and about 20.0 to about 0.1% by weight of a crosslinking monomer copolymerizable with the (meth)acrylate monomer. The composition can be used in formulating elastomeric compositions having a favorable balance of properties.

(Meth)acrylate copolymer and its elastomer compositions

An automotive weather strip comprising a base material, a urethane layer and an adhesive composition formed between the base material and the urethane layer, wherein said base material comprises an ethylene/propylene rubber and said adhesive composition comprises components (A) to (E), the weight ratio of component (A) to component (B) being 60:40 to 40:60,

Automotive weather strip

A rubber composition is provided which comprises 100 parts by weight of ethylene-(meth)-acrylate copolymer rubbers and/or ethylene-(meth)-acrylate-unsaturated glycidyl ester copolymers, 5 to 300 parts by weight of a hydroxide of a typical metallic element belonging to Group II or III of the Mendeleev's periodic table and 0.1 to 50 parts by weight of a metallic acrylate compound. This composition keeps properties required for rubbers such as tensile strength, elasticity, scorch resistance and processability at high levels and is excellent in wear resistance and flame retardance.

A process for producing ethylene-.alpha.-olefin copolymer rubbers which comprises mixing a vanadium compound-containing solution and an alcohol-containing solution with stirring for 10-600 seconds to obtain a mixed solution, immediately feeding the mixed solution into a polymerization vessel containing an organoaluminum compound, and copolymerizing ethylene and an .alpha.-olefin, or ethylene, an .alpha.-olefin and a non-conjugated diene compound in the polymerization vessel. According to this process, the activity of polymerization catalyst can be maintained at a high level, no by-product of the reaction of the vanadium compound and the alcohol is deposited as precipitate in the apparatus and no such additional operations as bubbling is necessary.

Process for producing ethylene-alpha-olefin copolymer rubber

A rubber composition for sponge rubber which contains following components (A).about.(E) and satisfies the following requirements that the ratio by weight of (A)/(B) is 30/70.about.99/1 and the amount of component (C) is 50.about.400 parts by weight per 100 parts by weight of the total amount of components (A) and (B):

Rubber compositions for sponge rubber

A graft polymer wherein an iodine-containing fluororubber has been grafted on an ethylene-.alpha.-olefin copolymer or other polymer can be obtained by mixing 30 parts by weight of an iodine-containing fluororubber (a vinylidene fluoride-hexafluoropropylene copolymer containing iodine) and 70 parts by weight of an ethylene-propylene copolymer rubber at 180.degree. C. for 30 minutes while applying shear deformation using a Brabender mixer.

Process for producing graft polymer

A rubber composition is provided which comprises 100 parts by weight of ethylene-(meth)acrylate copolymer rubbers and/or ethylene-(meth)acrylate-unsaturated glycidyl ester copolymers, 5 to 300 parts by weight of a hydroxide of a typical metallic element belonging to Group II or III of the Mendeleev's periodic table and 0.1 to 50 parts by weight of a metallic acrylate compound. This composition keeps properties required for rubbers such as tensile strength, elasticity, scorch resistance and processability at high levels and is excellent in wear resistance and flame retardance.

A rubber composition for tire treads comprising a rubber component consisting essentially of (A) 20 to 100% by weight of a solution-polymerized styrene-butadiene copolymer rubber having a Mooney viscosity ML.sub.1+4 of 30 to 200 at 100.degree. C. prepared by copolymerization of styrene, butadiene and a polyvinyl aromatic compound followed by coupling with a trifunctional or tetrafunctional coupling agent, and (B) 0 to 80% by weight of at least one rubber selected from the group consisting of an emulsion-polymerized styrene-butadiene rubber, a butadiene rubber, natural rubber and a synthetic polyisoprene rubber; and (C) 50 to 250 parts by weight of a carbon black having an iodine adsorption number of not less than 60 mg/g and an oil absorption of not less than 110 ml/100 g per 100 parts by weight of said rubber component; the tan .delta. peak temperature Tg of the cured product of said rubber composition being from -40.degree. to +5.degree. C. The tread rubber composition can be processed without causing bagging with a good dispersibility of carbon black and provides tires having a low rolling resistance and a high grip characteristic.

Rubber composition for tire treads

A rubber composition which is vulcanizable with organic peroxides and provides vulcanized rubber excellent in oil resistance, heat resistance, low-temperature resistance and compression set. The composition comprises 30 to 95 parts by weight of the following component (A) and 70 to 5 parts by weight of the following component (B) (wherein component (A)+component (B)=100 parts by weight) as well as 1 to 10 parts by weight of the following component (C) per 100 parts by weight of the total amount of the components (A) and (B):

Rubber compositions and vulcanized rubber compositions

A vulcanizable epoxy group-containing elastomer composition is disclosed, comprising (A) an epoxy group-containing elastomer, (B) an organic compound containing at least two ##STR1## bonds, wherein X and Y, which may be the same or different, each represents an oxygen atom or a sulfur atom, per molecule or an organic compound containing at least two carboxyl groups per molecule, and (C) a phosphine compound represented by formula: ##STR2## wherein R.sub.1 and R.sub.2, which may be the same or different, each represents an alkyl group having from 1 to 4 carbon atoms; and R represents a hydrogen atom or an alkoxy group having from 1 to 4 carbon atoms. The composition has excellent compression set, particularly in a high temperature atmosphere, as well as excellent mechanical characteristics.

Vulcanizable epoxy group-containing elastomer composition

An elastomeric butadiene copolymer prepared by a process which comprises copolymerizing butadiene, a polyvinyl aromatic compound and optionally styrene in a hydrocarbon solvent in the presence of an organolithium polymerization initiator and subjecting the resulting copolymer having lithium at the polymer end or ends to a coupling reaction with a trifunctional or tetrafunctional coupling agent, said butadiene copolymer satisfying the following conditions: (a) the content of styrene is at most 50% by weight, (b) the content of vinyl bonds in the butadiene portion is from 10 to 90% by weight, (c) the molecular weight distribution curve obtained by a high performance liquid chromatography has at least three peaks, and 5 to 60% by weight of all the polymer chains have a molecular weight which is at least 5 times the molecular weight in terms of standard polystyrene corresponding to the peak appearing on the lowest molecular weight side of the high performance liquid chromatogram, and (d) the Mooney viscosity (ML.sub.1+4, 100.degree. C.) is from 30 to 200. The butadiene copolymer has an improved processability with excellent resilience, wet grip property, abrasion resistance and mechanical properties, and is suitable for tire use.

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Ichihara, Japan

Keisaku Yamamoto