Mitsui Chemicals, Inc.

Mitsui Toatsu Chemicals, Incorporated

Osamu Uchida

Tadashi Asanuma

Tutomu Iwatani

Tetsunosuke Shiomura

Nobutaka Uchikawa

Tateyo Sasaki

Takeo Inoue

Shigeru Kimura

Ryuichi Sugimoto

Norihide Inoue

Katsumi Takeuchi

A syndiotactic polypropylene copolymer is disclosed which comprises 70 to 99.9 mole % of propylene and 0.1 to 30 mole % of an olefin other than propylene; in the,C-NMR spectrum of the syndiotactic polypropylene copolymer, a ratio of the intensity of a peak at about 20.2 ppm to the sum of the intensities of the total peaks attributable to methyl groups in propylene units at about 19-22 ppm being 0.3 or more. Also disclosed are extrusion-molded high-transparency articles, especially films and sheets and blown films, obtained by the extrusion of a polypropylene substantially having a syndiotactic structure.

Syndiotactic polypropylene copolymer and extruded polypropylene articles

The present invention is directed to a method for polymerizing an .alpha.-olefin characterized by using a catalyst system which is obtained by reacting a halogenated metallocene compound with an organometallic compound, and then bringing the resultant reaction product into contact with a compound which will be a stable anion by reaction with the reaction product of the halogenated metallocene compound and the organometallic compound. When the method of the present invention is carried out, a polyolefin can be obtained by the use of the inexpensive catalyst in a high activity per unit amount of the catalyst.

Metallocene-catalyzed olefin polymerization in the absence of aluminoxane

Disclosed herein is a process for preparing a syndiotactic polypropylene comprising washing with a hydrocarbon solvent a polymer obtained by polymerizing propylene in the presence of a catalyst comprising a transition metal compound having an asymmetric ligand. The slurry of the polymer obtained by the polymerization is treated with a .beta.-dicarboxy compound and an alcohol or with an alcohol containing hydrochloric acid gasunder non-aqueous conditions prior to the washing with a hydrocarbon solvent so that the residue of the catalyst used in the polymerization reaction may be rendered soluble in the hydrocarbon solvent, the properties of the resulting syndiotactic polypropylene are improved greatly.

Preparation process of syndiotactic polyproplene

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Osaka, Japan

Osamu Uchida