Other

Tetsuya Matsukawa

Minoru Terano

Masato Takahashi

Hideshi Satake

Nobutoshi Komori

Takahiro Oka

A polypropylene/ethylene block copolymer, which has a poly(ethylene-co-propylene) segment content of 5 to 100 wt. %, excluding 100 wt. %, and a total ethylene content of 2 to 95 wt. %. (a) The block polymer comprises polypropylene segments and poly(ethylene-co-propylene) segments chemically bonded thereto, and (b) the polypropylene segments and the poly(ethylene-co-propylene) segments have been synthesized in the presence of an olefin polymerization catalyst comprising an organometallic compound and a solid catalyst component comprising either titanium and a halogen, or titanium, magnesium, and a halogen. The block copolymer has a weight-average molecular weight of 100,000 or higher, is suitable for producing general-purpose molded articles, and has an excellent balance among mechanical properties, impact resistance, thermal properties, transparency, moldability, and other properties.

Propylene/ethylene block copolymer, blushing-resistant transparent polypropylene resin for molding, elastomer for molding, and molded article obtained from these

Propylene/ethylene block copolymer, blushing-resistant transparent polypropylene resin for molding, elastomer for molding, and molded article obtained therefrom

A process for preparing polypropylene-b-poly(ethylene-co-propylene) by the use of a tubular continuous polymerizer in the presence of an olefin-polymerizing catalyst comprising a solid catalyst component (1) composed of titanium and halogen; an organosilicon compound (2); and, if necessary, at least one electron-donating compound (3) selected from the group consisting of organosilicon compounds represented by the general formula: R Si(OR&prime;) (wherein R and R&prime; are each independently a C1-C10 hydrocarbon group; and n is an integer of 1 to 3) and nitrogenous heterocyclic compounds, wherein the solid catalyst component (1) is preliminarily brought into contact with the organosilicon compound (2) in the presence of the electron-donating compound (3), and then a polypropylene segment is formed through polymerization, followed by formation of a poly(ethylene-co-propylene) segment at the end of the polypropylene segment through polymerization. The process enables efficient preparation of the polymer with a reduced content of inorganic contaminants, even when the polymer is one having a weight-average molecular weight of as high as 100,000 or more.

Process for the preparation of polypropylene-b-poly(ethylene-co-propylene)

Propylene-ethylene block copolymer compositions and processes for production thereof

A propylene-ethylene block copolymer composition is disclosed which comprises 0.01 to 10% by weight of an A-B type propylene-ethylene block copolymer (C) consisting essentially of a polypropylene segment (A) and an ethylene-propylene random copolymer segment (B), and 99.99 to 90% by weight of a propylene polymer (D), wherein the A-B type propylene-ethylene block copolymer (C) comprises 5 to 80% by weight of the ethylene-propylene random copolymer segment (B) having an ethylene content of 10 to 90% by weight and the propylene polymer (D) comprises 60 to 95% by weight of a homopolymer of propylene or a copolymer of propylene containing a copolymerizable monomer therewith (D,) and 40 to 5% by weight of an ethylene-propylene random copolymer (D,).

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Kanagawa, Japan

Tetsuya Matsukawa