Sumitomo Chemical Company, Limited

Kiyoyuki Sugimori

Akio Imai

Keisaku Yamamoto

Kizuku Wakatsuki

Hayato Saba

Hiroyoshi Takao

Hiroyuki Harada

Nobuyuki Yoshida

Masahiro Fukuyama

Hideaki Yamada

Junichi Koshiba

Katsunari Inagaki

Yukio Naito

Masashi Hamba

Yuji Gotoh

Kohzoh Miyazaki

Minoru Takane

A method for purifying an ethylene-.alpha.-olefin olefin having at least 3 carbon atoms, or ethylene with an .alpha.-olefin having at least 3 carbon atoms and a nonconjugated diene compound, in a hydrocarbon solvent in the presence of a catalyst comprising a vanadium compound, an organoaluminum compound, and a halogenated ester compound, the method including a step of mixing and stirring the polymerization reaction mixture obtained by the polymerization reaction in an aqueous alkaline solution in such an amount as to give an aqueous phase having a pH of not lower than 10.0 after mixing and stirring, is disclosed. A method for purifying an ethylene-.alpha.-olefin copolymer is also disclosed, including a step of an oxidation treatment of the polymerization reaction mixture in an aqueous alkaline solution in such an amount as to give an aqueous phase having a pH of not lower than 10.0 after the oxidation treatment.

Method for purifying ethylene-.alpha.-olefin copolymer

An inert hydrocarbon solvent-soluble catalyst for polymerization of olefinic hydrocarbons and a process for producing an olefinic polymer using the same are disclosed, the catalyst being composed of (A) a reaction product obtained by reacting (a) at least one vanadium compound represented by formula:

Catalyst for olefinic hydrocarbon polymerization and process and

Herein is disclosed a vulcanizable rubber composition comprising a copolymer rubber constituted of ethylene, propylene and nonconjugated polyene, wherein ethylene/propylene molar ratio is 78/22 to 97/3 and the total content of propylene and nonconjugated polyene is 6 to 30% by mole in said copolymer rubber. By the use of the rubber composition of the present invention, a vulcanized product excellent in tensile strength, heat resistance, oil resistance, compression set resistance and flex behavior can be obtained. The vulcanized product can be used as automobile parts and other innumerable articles such as socket cover, heat resistant hose, electric wire, condenser cap, heat resistant belt, vibration-proof rubber, hoses, weather strip, seal sponge, black side wall of tire, etc.

Rubber composition

Catalyst for olefinic hydrocarbon polymerization and process for

Herein is disclosed a vulcanizable rubber composition comprising a copolymer rubber constituted of ethylene, propylene and nonconjugated polyene, wherein ethylene/propylene molar ratio is 78/22 to 97/3 and the total content of propylene and nonconjugated polyene is 6 to 30% by mole in said copolymer rubber. By the use of the rubber composition of the present invention, a vulcanized product excellent in tensile strength, heat resistance, oil resistance, compression set resistance and flex behavior can be obtained. The vulcanized product can be used as automobile parts and other innumerable articles such as socket cover, heat resistant hose, electric wire, condenser cap, heat resistant belt, vibration-proof rubber, hoses weather strip, seal sponge, black side wall of tire, etc.

An ethylene-.alpha.-olefin copolymer is disclosed, which comprises ethylene and an .alpha.-olefin having from 3 to 10 carbon atoms, has an ethylene/.alpha.-olefin molar ratio of from 88/12 to 98/2, and which has a number average molecular weight of from 35,000 to 80,000 and a weight average molecular weight/number average molecular weight ratio of from 1.8/1 to 3.0/1 as determined by gel permeation chromatography. A process for producing the ethylene-.alpha.-olefin copolymer is also disclosed. The ethylene-.alpha.-olefin copolymer exhibits excellent transparency and excellent low-temperature heat-sealing properties. The process is advantageous from the standpoint of equipment, energy and cost.

Ethylene-.alpha.-olefin copolymer and process for producing the same

An ethylene-.alpha.-olefin copolymer comprising ethylene and an .alpha.-olefin having from 3 to 10 carbon atoms, the copolymer having an .alpha.-olefin content of from 1.0 to 8.0 mol %, a density of from 0.900 to 0.930 g/cm.sup.3, and a melt flow rate of from 0.1 to 100 g/10 min., the programed-temperature thermogram of said copolymer as determined with a differential scanning calorimeter after being completely melted and then gradually cooled showing an endothermic peak (a) in a range of from 75.degree. to 100.degree. C. and an endothermic peak (b) in a range of from 120.degree. to 140.degree. C., with the ratio of an endotherm at the endothermic peak (b), .DELTA.Hb, to an endotherm at the endothermic peak (a), .DELTA.Ha, i.e., .DELTA.Hb/.DELTA.Ha, being from 0.03 to 2.0. The copolymer provides a film exhibiting excellent physical properties required for packaging film.

Ethylene-alpha-olefin copolymer and films obtained therefrom

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Chiba, Japan

Kiyoyuki Sugimori