Nissan Motor Company Limited

Nihon Plast Co., Ltd.

Other

Japan Polychem Corporation

Kazushige Ohnishi

Kazuyuki Yamamoto

Akira Kawai

Satoru Ichikawa

Motoru Komatsu

Kazuo Matsuyama

Tomio Hirata

Masahiro Terada

Hirosuke Kamae

Yukihito Zanka

Satoru Yoshikawa

Tamihiro Ohashi

Minoru Adachi

Takashi Niimi

Takuya Kurio

The invention relates to a polyolefin-based resin composition that is in an amount of 100 wt % in total. This composition includes (a) 60-66 wt % of a crystalline propylene-ethylene block copolymer, (b) 12-20 wt % of an ethylene-propylene copolymer rubber, and (c) 18-25 wt % of an inorganic filler. The block copolymer contains a first segment of a homopolymer of propylene and a second segment of a copolymer of propylene and ethylene, and has an isotactic pentad tacticity of at least 0.96. The ratio of the weight average molecular weight of the block copolymer to the number average molecular weight thereof is not greater than 6. The copolymer rubber contains therein 50-60 wt % of ethylene, and has a Mooney viscosity of from 45 to 55 at 125&deg; C. The inorganic filler is one selected from the group consisting of a talc, a first combination of the talc and a glass fiber, and a second combination of the talc and a whisker. The talc has an average particle diameter of not greater than 2 &mgr;m. The glass fiber has an average fiber length of from 5 to 10 mm and an average diameter of from 15 to 20 &mgr;m. The whisker has an average fiber length of from 15 to 25 &mgr;m and an average diameter of from 0.5 to 1 &mgr;m. A molded plastic article made from the resin composition is substantially improved in scratch resistance.

Polyolefin-based resin composition and automotive molded plastic made from same

A polyolefin-based plastic composition suitable for an automotive molded pillar member such as a pillar garnish. The plastic composition comprises (A) block copolymer in an amount ranging from 53 to 68 parts by weight, the block copolymer having a Melt Flow Rate (at 230.degree. C. and under 2.16 kg) ranging from 20 to 50 g/10 min. and containing crystalline polypropylene section in an amount ranging from 90 to 95% by weight, having a density of not lower than 0.908 g/cm.sup.3, and propylene-ethylene random copolymer section in an amount ranging from 5 to 10% by weight, the propylene-ethylene random copolymer section having an ethylene content ranging from 35 to 45% by weight; (B) ethylene-1-butene copolymer rubber in an amount ranging from 12 to 20 parts by weight and having a density ranging from 0.85 to 0.87 g/cm.sup.3 and a Melt Flow Rate (at 230.degree. C. and under 2.16 kg) ranging from 0.2 to 5 g/10 min., the copolymer rubber containing 1-butene in an amount ranging from 30 to 40% by weight; and (C) talc in an amount ranging from 22 to 30 parts by weight and having a length not more than 15 .mu.m and an average particle size ranging from 1.5 to 6 .mu.m, the talc having an average aspect ratio not lower than 5. The polyolefin-based plastic composition has a Melt Flow Rate (at 230.degree. C. and under 2.16 kg) not lower than 8 g/10 min., a Flexural Elastic Modulus not lower than 1960 MPa when molded, and an IZOD not lower than 0.088 KJ/m when molded, and a Rockwell hardness (in R scale) not lower than 65 when molded.

Polyolefin-based plastic composition and automotive molded article

A pillar garnish for a front pillar disposed between a front windshield glass and a side window glass of an automotive vehicle. The pillar garnish comprises a main body section formed of plastic and secured to a vehicle body. The main body section is generally channel-shaped to cover the front pillar forming part of the vehicle body. The main body section has an inner surface facing the front pillar, and an outer surface facing a vehicle passenger inside a passenger compartment. A plurality of reinforcement ribs are formed at the inner surface of the main body section and integral with the main body section. Each reinforcement rib extends perpendicular to the inner surface. Additionally, a plurality of auxiliary ribs are formed at the inner surface of the main body section and integral with the main body section. Each auxiliary rib extends parallel with each reinforcement rib. Each rib is located between the reinforcement ribs which are located adjacent each other. Each rib extends to occupy at least a part of a region surrounded by the inner surface of the main body section and first and second imaginary straight lines in a transverse plane perpendicular to a longitudinal axis of the main body section.

Interior material for automotive vehicle

Growing community of inventors

Shizuoka, Japan

Kazushige Ohnishi