Mitsui Petrochemical Industries, Ltd.

Hideaki Yamaguchi

Toshihiro Sagane

Shuji Minami

Syuji Minami

Akira Mizuno

Hiroo Wamura

Hidekuni Oda

Shigemi Shiraki

Hirokazu Kajiura

Masayuki Okabe

Kenji Wakatsuru

Ryosuke Tomita

Takehiko Kawate

Kotaroh Kishimura

This invention is to provide a novel process for the isomerization of a cycloolefin having an endo form to a cycloolefin having an exo form. The resulting isomer mixture has a novel composition, and a random copolymer produced from the above compositionally novel isomer mixture and ethylene has an excellent heat resistance and mechanical strength.

Isomerization of cycloolefin from endo-form to exo-form and

In accordance with the present invention, there are provided cycloolefin random copolymers composed of ethylene and cycloolefin and containing substantially no polyethylene, and processes for preparing the same. Optical disc substrates prepared from the above-mentioned copolymers are excellent in transparency and also capable of minimizing the occurence of errors in reading of the discs due to quality of the substrates used therefor.

Cycloolefin random copolymer and process for preparing same

The present invention is intended for the preparation of a cycloolefin random copolymer, which is a copolymer of ethylene, cycloolefin and if necessary .alpha.-olefin, in a high yield. The process for preparing a cycloolefin random copolymer according to the invention is a process for preparing a cycloolefin random copolymer comprising repeating units derived from (i) ethylene in an amount of 40 to 97% by mol, repeating units derived from (ii) cycloolefin in an amount of 3 to 60% by mol and repeating units derived from (iii) .alpha.-olefin of 3-20 carbon atoms in an amount of 0 to 20% by mol, wherein (i) ethylene, (ii) cycloolefin and if necessary (iii) .alpha.-olefin of 3-20 carbon atoms are copolymerized in a liquid phase in the presence of a catalyst formed from (A) a soluble vanadium compound having a tertiary alkoxy group or .beta.-diketone as a ligand and (B) an organoaluminum compound represented by the formula (i-Bu) .sub.n AlCl.sub.3-n wherein n is 1.0 to 2.5.

Process for preparing cycloolefin random copolymer

A random copolymer characterized in that (A) the copolymer comprises polymerized units from ethylene and polymerized units from at least one cycloolefin, (B) the mole ratio of the polymerized units from the cycloolefin to the polymerized units from ethylene is from 3:97 to 60:40, (C) the cycloolefin is incorporated in the polymer chain without ring opening, (D) the copolymer has an intrinsic viscosity of 0.01 to 20 dl/g, (E) the copolymer has a molecular weight distribution (Mw/Mn) of not more than 4, and (F) the copolymer has a crystallinity of 0 to 10%. The random copolymer may be grafted by (a) alpha, beta-unsaturated carboxylic acids and/or their derivatives, (b) styrenes, (c) organic silicon compounds having an olefinically unsaturated bond and a hydrolyzable group, or (d) unsaturated epoxy monomers. The random copolymer is produced by continuously copolymerizing ethylene with at least one cycloolefin in a hydrocrbon medium in the presence of a catalyst formed from a soluble vanadium compound and an organoaluminum compound while maintaining the atomic ratio of vanadium atoms to aluminum atoms in the reaction system, V/Al, at 2 or higher.

Random copolymer, and process for production thereof

Copolymerization of ethylene and cycloolefin isomerized from endo-form

A process for producing a cycloolefin random copolymer, which comprises

Process for producing cycloolefin random copolymer

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Iwakuni, Japan

Hideaki Yamaguchi