Mitsui Toatsu Chemicals, Incorporated

Mitsui Chemicals, Inc.

Tutomu Iwatani

Tadashi Asanuma

Tetsunosuke Shiomura

Nobutaka Uchikawa

Tateyo Sasaki

Ryuichi Sugimoto

Shigeru Kimura

Takeo Inoue

Osamu Uchida

Katsumi Takeuchi

Takayuki Yamada

Norihide Inoue

Yukio Ishii

Kouji Kitabayashi

Kazumi Mizutani

Yoshiho Sonobe

Mitsuru Ito

Kaoru Kawanishi

Satoshi Fukushima

Masashiro Kouno

Yukari Tamai

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

The invention provides a polymeric insulating material having a high dielectric breakdown voltage. The material comprises polypropylene which has been obtained in a yield of at least 300,000 g/g-Ti based on titanium in a catalyst upon polymerization, contains ash in an amount not greater than 40 ppm by weight when analyzed by completely burning the polypropylene in air, said ash containing titanium in an amount not greater than 1 ppm by weight based on the weight of the polypropylene, and also contains chlorine in an amount not greater than 2 ppm by weight and boiling n-heptane soluble matter in an amount not smaller than 1 wt. % but not greater than 10 wt. %. To further improve the dielectric breakdown voltage an inorganic oxide or hydroxide free of particles of 10 .mu.m and greater in diameter and having an average particle size not greater than 1 .mu.m, an organopolysilane, a maleic-anhydride-grafted polypropylene, or a silane compound containing at least one organic polyether group can be added to the polypropylene.

Polymeric insulating material and formed article making use of the

The invention provides a polymeric insulating material having a high dielectric breakdown voltage. The material comprises polypropylene which has been obtained in a yield of at least 300,000 g/g-Ti based on titanium in a catalyst upon polymerization, contains ash in an amount not greater than 40 ppm by weight when analyzed by completely burning the polypropylene in air, said ash containing titanium in an amount not greater than 1 ppm by weight based on the weight of the polypropylene, and also contains chlorine in an amount not greater than 2 ppm by weight and boiling n-heptane soluble matter in an amount not smaller than 1 wt. % but not greater than 10 wt. %. According to the invention, it is possible to further improve the dielectric breakdown voltage by adding to the polypropylene an inorganic oxide or hydroxide free of particles of 10 .mu.m and greater in diameter and having an average particle size not greater than 1 .mu.m, an organopolysilane, a maleic-anhydride-grafted polypropylene, or a silane compound containing at least one organic polyether group.

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

Disclosed herein is a polypropylene resin composition of a high syndiotacticity comprising a substantial homopolymer of propylene, in which the ratio of the intensity of the peak attributable to the syndiotactic pentad bonds to the sum of the intensities of all the peaks attributable to the methyl groups in the spectrum of the methyl groups measured by .sup.13 C-NMR is 0.7 or more, and a copolymer of ethylene and propylene, and a preparation process thereof.

Polypropylene resin compositions of high syndiotacticity and preparation

Copolymers of butene-1 and propylene, having specific physical properties and substantially a syndiotactic structure; and easily heat-sealable polypropylene resin compositions comprising 5-50 parts by weight of one of the copolymers and 95-50 parts by weight of a stereoregular crystalline propylene-ethylene copolymer or propylene ethylene-C.sub.4-12 -.alpha.-olefin copolymer having specific compositions and melt flow index.

Butene-1 copolymers and resin compositions containing the same

Propylene copolymer

Copolymers of butene-1 and propylene, having specific physical properties and substantially a syndiotactic structure; and easily heat-sealable polypropylene resin compositions comprising 5-50 parts by weight of one of the copolymers and 95-50 parts by weight of a stereoregular crystalline propylene-ethylene copolymer or propylene-ethylene-C.sub.4-12 -.alpha.-olefin copolymer having specific compositions and melt flow index.

Butene-1 copolymer and resin composition containing the same

An improved method for preparing block copolymers of propylene which comprises providing a polymerizer composed of at least two reaction vessels connected to one another, substantially homopolymerizing propylene in a first step and then copolymerizing ethylene and propylene in a second step in the presence of a stereoregular catalyst, characterized by carrying out the homopolymerization of propylene in the polymerizer composed of at least two reaction vessels connected to one another in series, then introducing the resulting polymer slurry into a countercurrent washing column and countercurrently washing the slurry with propylene, introducing the washed slurry withdrawn from the lower part of the washing column into a reaction vessel in the second step connected to the washing column and performing the polymerization of ethylene and propylene, of which ratio ranges from 15/85 to 95/5. According to this method, a block copolymer of propylene exhibiting excellent physical properties can be obtained efficiently.

Method for preparing block copolymers of propylene

A copolymer of propylene and butene-1, the constituent monomer units of which comprise 20-63 wt. % of propylene and 37-80 wt. % of butene-1, and which exhibits 0.5 or more in the ratio of the sum of the intensities of absorptions observed at about 20.0-21.0 ppm to the sum of the intensities of total absorptions attributable to the methyl groups in the propylene units observed at about 19.0-22.0 ppm in the .sup.13 C-NMR spectrum measured in a 1,2,4-trichlorobenzene solution and 0.05 or more in the intrinsic viscosity measured at 135.degree. C. in a tetralin solution.

Copolymer of propylene and butene-1

A polymer of 4-methylpentene-1 having a substantially syndiotactic structure, which polymer contains 0 to 30 mol % of the .alpha.-olefin unit other than the 4-methylpentene-1 unit and has excellent physical properties.

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Osaka, Japan

Tutomu Iwatani