Mitsubishi Petrochemical Company Limited

Yuji Ozeki

Takeo Shimada

Hajime Ikeno

Iwao Ishino

Akiyoshi Oonishi

Yoshikazu Higaki

Tadao Okada

Koshi Matsubara

Kenichi Nakamura

A copolymer is manufactured by allowing ethylene (A) and vinyl compounds (B) represented by the following general formula to undergo radical polymerization at a pressure of 1000-5000 kg/cm.sup.2 and a temperature of 100.degree.-400.degree. C., ##STR1## wherein R.sub.1 and R.sub.2 are each an independent hydrogen atom or a methyl group, R.sub.3 is a hydrogen atom or an alkyl group of 1-4 carbon atoms; a ratio of (B) to the sum of (A) and (B) is less than 1 mol %; a proportion of the amount of vinyl compounds (B), which are not successively bonded at all to the units (B) in the chain, but bonded to unlike units (A) on both sides thereof, to the total amount of (B) units in the copolymer is at least a 83%; and an MFR of the copolymer ranges from 0.1 to 200 g/10 min. Although the copolymer contains only a small amount of the vinyl compound (B) it nevertheless has excellent photo stabilizing effects.

Ethylene copolymer and method of producing same

A copolymer of ethylene and an ethylenically .alpha.,.beta.-unsaturated acid halogenated phenyl ester represented by the formula (1): ##STR1## (wherein R is hydrogen or a methyl group, X is a halogen atom, Y is an alkyl group having 4 to 18 carbon atoms, n is 0 or 1, m is an integer of 1 to 5, and l is 0 or an integer of 1 to 4), wherein the halogenated phenyl ester group unit content is about 0.005 to about 10 mol %. This copolymer is excellent in dielectric breakdown characteristics and flexibility, and its excellent performance can be maintained over a long period of time. Thus, it is useful as a superhigh voltage electric wire cable insulative material.

Ethylene copolymer and process for the production thereof

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Yokkaichi, Japan

Yuji Ozeki