Mitsui Toatsu Chemicals, Incorporated

Mitsui Chemicals, Inc.

Tadashi Asanuma

Nobutaka Uchikawa

Tetsunosuke Shiomura

Tateyo Sasaki

Shigeru Kimura

Tutomu Iwatani

Kazuhiko Yamamoto

Mitsuru Ito

Kaoru Kawanishi

Takeo Inoue

Akihiro Yamaguchi

Ichiro Fujio

Shoji Tamai

Hideaki Oikawa

Yuichi Okawa

Ryuichi Sugimoto

Kaneo Ito

Tatuo Ohoka

Yoshiyuki Funakoshi

Keizaburo Yamaguchi

Wataru Yamashita

Mitsunori Matsuo

Norihide Inoue

Osamu Uchida

Katsumi Takeuchi

Satoshi Fukushima

Saburo Kawashima

Naoya Ogata

Yoichi Kawai

Tadahiro Sunaga

Yoshihiro Sakata

Katsuaki Iiyama

Keigo Suehiro

Akihiko Nakajima

Takehisa Nakanishi

Hiroshi Matsuzawa

Junko Ohnaka

Yoshiko Tokura

Kouji Kitabayashi

Hideaki Okikawa

Yukari Nishimori

Shosuke Nakanishi

Tetusnosuke Shiomura

Takayuki Yamada

Kazumi Mizutani

Yoshiho Sonobe

Nobuhito Koga

Masahiro Kouno

Akira Ito

Tsutomu Ishida

Yuko Ishihara

Masahiro Kaneko

Tamio Kawasumi

Toshiyuki Kataoka

Yukio Ishii

Takao Tanaka

Masumi Okita

Yukari Tamai

Masashiro Kouno

Tsutomu Iwatani

Masami Hashimoto

Shunji Ueda

Minoru Hino

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

Preparation of hydrogenated product of cyclic olefin ring-opening metathesis polymer

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

An olefin polymerization catalyst system comprising an organic transition metal compound and a support, wherein an organic transition metal compound is soluble in an inert organic solvent and a support which is insoluble in the inert organic solvent, and the support comprises an organic high molecular weight compound which contains a specific carbonyl-containing group. The catalyst system can polymerize an olefin in a high activity, provides polymer with high stereoregularity, prevents adhesion or fouling of the polymer generated in the course of polymerization or an organic aluminum oxy compound on the inner wall of the reactor, leads to high bulk density of the polymer and very reduced level of fisheye and/or gel generation on the processed item, can maintain high productivity, can manufacture high quality product, and thus provides extremely high contribution in industry.

Olefin polymerization catalyst system

A method for preparing molded articles of a crosslinked polyolefin is here disclosed which comprises the steps of mixing polyolefin granules comprising polyolefin granules containing a hydrosilylation catalyst, polyolefin granules containing the copolymer of an alkenylsilane and an olefin, and if necessary, polyolefin granules containing neither the hydrosilylation catalyst nor the copolymer of the alkenylsilane and the olefin, and then heating, melting and molding the mixture in a molding machine. According to the present invention, the molded articles of the crosslinked polyolefin containing no residual crosslinking agent and having improved heat resistance and mechanical strength can be obtained by the easy method which comprises mixing the above-mentioned respective granules, and then heating, melting and molding the mixture.

Method for preparing molded articles of cross-linked polyolefin

A multi-layer blow molded article of a polypropylene comprising at least two layers, wherein at least one layer of the inner layer or layers comprises a resin composition containing 100-50 parts by weight of a syndiotactic polypropylene with an Mw/Mn of 3.0 or more and 0-50 parts by weight of an ethylene-.alpha.-olefin copolymer elastomer, and the outermost layer comprises a syndiotactic polypropylene with an Mw/Mn of less than 3.0, an isotactic polypropylene with an Mw/Mn of 6.0 or less, a resin composition containing 99-50 parts by weight of either of said polypropylenes and 1-50 parts by weight of an ethylene-.alpha.-olefin copolymer elastomer, or a polypropylene formed by heat degradation of a syndiotactic or isotactic polypropylene and having an Mw/Mn of 3.0 or more.

Multi-layer blow molded article of polypropylene

A molded article obtained by blow molding a propylene having a substantially syndiotactic structure or a resin composition comprising a polypropylene having a substantially syndiotactic structure and a copolymer of ethylene and propylene, and a multi-layer molded article obtained from this resin composition in which at least one surface of the molded article is a polypropylene layer having the substantially syndiotactic structure.

Transparent impact-resistant molded articles

A molded article of a syndiotactic polypropylene having excellent transparency in which a melting point attributed to the polypropylene having the syndiotactic structure measured at a heating rate of 10.degree. C./minute by differential scanning thermal analysis is represented by a substantially single peak, the aforesaid molded article being prepared by heating, melting and then hot-molding a homopolymer of propylene or a copolymer of propylene and a small amount of another olefin, which have a substantially syndiotactic structure, or a mixture of the homopolymer or the copolymer and a small amount of a polypropylene having a substantially isotactic structure, followed by quenching, or, after these steps, additionally subjecting the above molded article to a heat treatment at a temperature of less than its melting point. A method for preparing the above molded article is also disclosed here.

Method for preparing molded articles of syndiotactic polypropylene

A fiber excellent in strength and having an average size of 10,000-0.1 denier can be obtained by extruding a new material composed mainly of a polypropylene having a syndiotactic pentad fraction of 0.7 or more and optionally stretching the resulting extruded material. By using as the raw material a composition consisting of two kinds of polypropylenes each having an intrinsic viscosity .eta..sub.1 or .eta..sub.2, the log(.eta..sub.2 /.eta..sub.1) being more than 0.05 or less than -0.05, and a syndiotactic pentad traction of 0.7 or more at a weight ratio of 95:5-5:95 or a composition consisting of at least 50 parts by weight of a syndiotactic polypropylene having the intrinsic viscosity .eta..sub.1 and a syndiotactic pentad fraction of 0.7 or above and at most 50 parts by weight of an isotactic polypropylene having the intrinsic viscosity .eta..sub.2, the extrudability is improved and the fiber stretching conditions are broadened.

Process of making polyprophylene fibers

Molded articles of syndiotactic polypropylene and method for preparing

A radiation-resistant polypropylene resin composition is disclosed which comprises a polypropylene having a substantially syndiotactic structure, and if desired, a phosphorus-containing anti-oxidant, an amine-containing anti-oxidant and/or a nucleating agent. Molded articles obtained from this resin composition can be utilized as containers for foods and medicines, and their physical properties scarcely deteriorate during sterilization by radiation.

Radiation-resistant polypropylene resin composition

Disclosed is a syndiotactic propylene copolymer containing 0.01 to 40 mol % of olefin units containing --OH group in the side chain. Of absorption peaks attributed to the methyl groups of the propylene units on an absorption spectrum by .sup.13 C-NMR of the copolymer, the intensity of an absorption peak observed at about 20.2 ppm is 0.3 or more of the intensity of absorption peaks of all the methyl groups attributed to the propylene units. The copolymer is produced by copolymerizing propylene and an alkenylsilane or alkenylborane compound in the presence of a catalyst system comprising an asymmetric ligands-having transition metal compound and an aluminoxane, followed by heat-treating the resulting propylene-alkenylsilane copolymer in the presence of a trialkylamine oxide and KF.HF or oxidizing and decomposing the resulting propylene-alkenylborane compound copolymer. Also disclosed is a resin composition comprising the copolymer and other polyolefin(s).

Syndiotactic propylene copolymer, preparation of the same, and resin

A polyimide resin composition substantially comprising 1 99.9.about.50 parts by weight of polyimide having recurring structural units of the formula ##STR1## and 2 0.1.about.50 parts by weight of a polyimide which improved melt flowability and is prepared by using 1,3-bis(3-aminophenoxy)benzene or 6,6'-bis(3-aminophenoxy)-3,3,3',3'-tetramethyl-1,1'-spirobiindane as essential diamine component, or polyether pyridine having recurring structural units of the formula: ##STR2## is disclosed. Further, a polyimide based resin composition comprising the polyimide resin composition or a polyimide copolymer obtained by using the above diamines and a fibrous reinforcement is disclosed. These compositions have remarkably good processability, excellent heat stability and repeated fatigue characteristics.

Polyimide resin composition

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Takaishi, Japan

Tadashi Asanuma