Sumitomo Chemical Company, Limited

Yuji Ikezawa

Hideo Shinonaga

Susumu Kanzaki

Hiroyuki Harada

Satoru Sogabe

Takahisa Hara

Taichi Nishio

Tatsuyuki Mitsuno

Teruhisa Koyama

Taisuke Okita

Taro Harada

A polypropylene resin composition, which exhibits an excellent coating adherence, high rigidity, high impact strength at low temperatures, prominent heat resistance and excellent appearance of moldings even without effecting a treatment with trichloroethane as a pretreatment step before coating, comprises 30 to 92% by weight crystalline ethylene propylene block copolymer (A), 5 to 30% by weight ethylene-.alpha. olefin copolymer rubber (B), 3 to 20% by weight ethylene-butene-1 copolymer (C) having the following characteristics:

Polypropylene resin composition

A polypropylene resin composition, which exhibits an excellent coating adherence, high rigidity, high impact strength at low temperatures, prominent heat resistance and excellent appearance of moldings as required for coatings on the exterior parts of automobiles even without effecting a treatment with trichloroethane as pretreatment step before coating and without a primer as undercoating and which can be baked at a temperature of 130.degree. C. or higher, comprises 15 to 92% by weight crystalline ethylene propylene block copolymer, 5 to 40% by weight ethylene propylene copolymer rubber, 1 to 15% by weight polypropylene oligomer containing hydroxyl group, and 2 to 30% by weight inorganic filler.

A mica-reinforced propylene resin composition having a volatile matter at 105.degree. C of 0.12% or less is obtained by heating and melting a mixture containing (A) a crystalline polypropylene, (B) mica treated with an organosilane compound, (C) a bismaleimide compound, and (D) an organic peroxide. It has excellent stiffness, heat resistance and dimensional stability, does not corrode a mold, and does not exhale an irritating odor during molding.

Mica-reinforced propylene resin composition

A resin composition is provided which comprises a crystalline propylene-ethylene copolymer resin mixed with mica having a specified average particle diameter and particle size distribution or a rubber-like material so that it shows an excellent balance between rigidity and impact strength and an excellent thermal resistance and provides an excellent appearance when formed in products. In a preferred embodiment, the polypropylene resin composition comprises 50 to 97% by weight of a crystalline propylene-ethylene copolymer resin, 0 to 20% by weight of a rubber-like material, and 3 to 50% by weight of mica having an average particle diameter determined by photo extinction sedimentation method of 0.5 to 4.5.mu. and a particle size distribution of 95% or more by weight for 10.mu. or less, 60% or more by weight for 5.mu. or less, and 10 to 80% by weight for 1.mu. or less.

Polypropylene resin composition comprising talc having specified average

Polyolefin compositions comprising (I) crystalline polyolefin and (II) a mixture of inorganic fillers 5 to 45% by weight based on the total weight of said polyolefin and mixture, said mixture comprising (1) 40 to 95% by weight of a powder of a mixture of predominant calcium metasilicate and 0.2 to 20% by weight of calcium carbonate, said powder being in the long and narrow shape and more than 98% by weight thereof being passable through a 200-mesh Tyler's standard sieve, and (2) 60 to 5% by weight of hydrated magneium silicate powder which is passable through a 325-mesh Tyler's standard sieve.

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Nagoya, Japan

Yuji Ikezawa