Nippon Oil Company

Yoshiyuki Shimo

Kazuo Matsuura

Nobuyuki Kuroda

Naoki Kataoka

Yutaka Shikatani

Hiroshi Kobayashi

Yoshio Tajima

Takeichi Shiraishi

Seizo Kobayashi

Kazutosi Nomiyama

Etsuo Kawamata

Hobuyuki Kuroda

A polyethylene article such as film or fiber having high strength and high elastic modulus is produced by orienting an ultra-high molecular weight polyethylene having an intrinsic viscosity at 135.degree. C. in decalin of 5 to 50 dl/g, said ultra-high molecular weight polyethylene being prepared by homo- or copolymerizing ethylene in the presence of a catalyst system and hydrogen, said catalyst system comprising (1) a solid catalyst component containing at least magnesium, titanium and/or vanadium, (2) an organometallic compound and (3) a compound represented by the following general formula �I!: ##STR1## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 are each hydrogen or a hydrocarbon residue, with the proviso that any two of R.sup.1, R.sup.2, R.sup.3 and R.sup.4 may conjointly form a cyclic hydrocarbon residue.

Process for producing polyethylene material of high strength and high

An electroactive polymer is obtained by doping a copolymer represented by the following general formula (I): ##STR1## wherein R.sup.1 is hydrogen or a hydrocarbon residue having 1 to 20 carbon atoms; R.sup.2 is hydrogen, a hydrocarbon residue having 1 to 20 carbon atoms, furyl, pyridyl, nitrophenyl, chlorophenyl, or methoxyphenyl; l is an integer not smaller than 2; m is an integer not smaller than 1; and n is an integer not smaller than 2.

Novel compolymers and electroactive polymers derived therefrom

Provided is a copolymer having a repeating unit represented by the general formula ##STR1## wherein Ar represents ##STR2## wherein R.sup.1 represents hydrogen or a hydrocarbon group having 1 to 20 carbon atoms, R.sup.2 represents hydrogen, a hydrocarbon group having 1 to 20 carbon atoms, furyl, pyridyl, chlorophenyl, nitrophenyl or methoxyphenyl, n is 1 or more and an electroactive polymer obtained by doping the above copolymer.

Novel copolymers and electroactive polymers derived from same

Disclosed is polyethylene composition having excellent environmental stress cracking resistance (ESCR) and giving molded articles with good surface properties. This composition comprises a blend of two specific types of polyethylene selected with due consideration for their molecular weight distribution in addition to their molecular weights, so that it has excellent melt tension, ESCR and moldability. Accordingly, it can suitably be used in blow molding and extrusion molding to produce molded articles with no shark skin, as well as vessels of very large size. This composition is formed by blending (A) polyethylene obtained according to a two-step polymerization process using a Ziegler catalyst containing magnesium and titanium, and (B) high-molecular-weight polyethylene obtained with the aid of a chromium-containing catalyst, in a specified proportion.

Polyethylene composition

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Yokohama, Japan

Yoshiyuki Shimo