Mitsubishi Petrochemical Company Limited

Oji Yuka Goseishi Co., Ltd.

Fukashi Hashimoto

Masaaki Yamanaka

Tetsuji Kakizaki

Takashi Toyoda

Yozo Ohba

A stretched film having excellent printing and writing properties and mechanical strength is produced by stretching a film molded from a styrene-grafted polyolefin resin in at least one direction. The styrene-grafted polyolefin resin is produced by heating an aqueous suspension containing 100 parts by weight of polyolefin resin particles, from 10 to 400 parts by weight of a styrene monomer, and a free radical polymerization initiator in an amount of from 0.01 to 1 part by weight per 100 parts by weight of the styrene monomer.

Stretched film

This invention relates to biaxially oriented polypropylenefilm and method for its production. The method for its production comprises a step of fusing and extruding polypropylene in a sheet form, a step of cooling and solidifying a formed polypropylene film, a step of preheating it and a step of orienting it in a longitudinal direction and finally in a lateral direction, characterized in that a longitudinal orientation of the polypropylene film is carried out by at least a double-stage process. The polypropylene film thus biaxially oriented has improved rigidity.

Biaxially oriented polypropylene film and method for its production

A biaxially-stretched polypropylene composite film comprises a biaxially-stretched substrate film of a crystalline polypropylene and a monoaxially- or biaxially-stretched film of a resin composition bonded in laminated state to at least one surface of the substrate film, the resin composition comprising 96 to 50 percent (by weight) of a propylene copolymer (a), 3 to 30 percent of a polybutene-1 (b), and 1 to 20 percent of an ethylene-propylene-butene-1 random copolymer (c). The propylene copolymer (a) is an ethylene-propylene random copolymer (a.sub.1), an ethylene-propylene-butene-1 random copolymer (a.sub.2), or a mixture (a.sub.3) of at least two kinds of copolymers each of at least two monomers selected from ethylene, propylene, and butene-1. The resin composition comprising the components (a), (b) and (c) is also provided and is characterized by its capability of being heat sealed at low temperatures.

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Yokkaichi, Japan

Fukashi Hashimoto