Mitsubishi Petrochemical Company Limited

Takeo Shimada

Tsutomu Isaka

Yoshiteru Kageyama

Iwao Ishino

Akiyoshi Oonishi

Shigekazu Hayashi

Noriyuki Okada

Yukimasa Miwa

Mitsuyuki Matsuura

Shuhei Doi

Yoshio Kobayashi

Shuhei Yada

Takayuki Inoue

Hideaki Nakagawa

Masaki Saito

Mitsugu Ishioka

Nobuhiro Usami

Yuji Ozeki

Akito Hagiwara

Takashi Fujimoto

Michito Ukita

A novel process for production of polyethylene comprises polymerizing ethylene or a mixture of ethylene and a copolymerizable comonomer in the presence of a Ziegler-type catalyst at a pressure of 200 atm or more and at a temperature of 125.degree. C. or more, wherein an organic peroxide is added to the resulting polymerization product taken out of a reaction zone to deactivate the remaining catalyst. Formation of undesired oligomers or low-molecular polymers is prevented because the reaction does not proceed in the polymerization product taken out of the reaction zone. There is almost no retardation of the polymerization reaction even by the recycled use of the monomer separated and collected from the polymerization product.

Process for production of polyethylene

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

As a fuel oil additive, an ethylenic copolymer is provided which is derived from:

Fuel oil additive and fuel oil having improved flowability

An ethylene copolymer comprising an ethylene unit and an ester unit selected from ethylenically .alpha.,.beta.-unsaturated acid esters represented by the formula (I) or (II): ##STR1## wherein R.sup.1 represents a hydrogen atom or a methyl group; and R.sup.2 represents a halogenated alkyl group having from 1 to 15 carbon atoms; ##STR2## wherein R.sup.3 represents a hydrogen atom or a methyl group; and n represents 0 or 1,

Ethylene copolymer

The water absorptive resin composition of this invention is a composite comprising 5 to 95% of a carboxylate-containing water absorptive resin and 95 to 5% of a glycidyl group-containing polyolefin. The process for producing this water absorptive resin composition according to this invention comprises kneading a carboxylate-containing water absorptive resin and a glycidyl group-containing polyolefin under the kneading conditions of a kneading temperature of 120.degree. to 280.degree. C. and a residence time in a kneader of 2 seconds or more. According to this invention, there is produced a composition of excellent water absorptivity, shape maintenance and moldability into a film.

Water absorptive resin compositions and process for producing the same

An ethylene copolymer comprising ethylene and a compound of formula (I) ##STR1## wherein R.sup.1 represents a hydrogen atom or a methyl group, and R.sup.2 represents a methyl group or an ethyl group, the content of the compound of formula (I) being from 0.005 to less than 10 mole %, and the copolymer being a random copolymer prepared by radical polymerization of ethylene and the compound of formula (I).

A process for catalytic homo- or co-polymerization of ethylene under the conditions of a pressure of at least 300 kg/cm.sup.2, a temperature of at least 180.degree. C., a contact time with a catalyst of 10 to 150 seconds and substantial absence of a solvent is disclosed. The catalyst used comprises Components A and B where Component A is a solid composition prepared by mixing and pulverizing (1) a magnesium halide, (2) titanium trichloride, and (3) an electron donor and Component B is an organoaluminum compound containing a halogen.

Process for polymerizing ethylene

A crosslinkable polyethylene resin composition comprises, basically, (A) a copolymer of ethylene and an ethylenically unsaturated silane compound, wherein the content of the ethylenically unsaturated silane compound unit is 0.001 to 15 percent by weight, and (B) a silanol condensation. The copolymer may further comprise a monomer copolymerizable with the ethylene and the ethylenically unsaturated silane compound. The composition may be expandable, further comprising a foaming agent and may further comprise a polyolefin and a filler and may be in the form of a film or sheet.

Crosslinkable polyethylene resin compositions

A copolymer of ethylene and a minor proportion of an .alpha.-olefin having 4 to 10 carbon atoms is characterized by having the properties

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Yokkaichi, Japan

Takeo Shimada