Idemitsu Petrochemical Co., Ltd.

Honda Giken Kogyo Kabushiki Kaisha

Ryuzo Tomomatsu

Manabu Nomura

Minoru Sugawara

Youichi Matsuo

Tetsuya Oda

Kazuaki Kihara

Naoki Narukawa

Takumasa Fukuda

Tetsushi Yamada

A propylene-based resin composition has good external appearance due to good weld appearance and low gloss and has excellent mechanical properties such as impact resistance and stiffness. The composition is well-balanced in the external appearance and mechanical properties. Automotive interior trims made of the composition are also described. The propylene-based resin composition comprises (A) 60 to 90% by weight of a propylene-based resin (1) comprising 78 to 88% by weight of 23&#xb0; C. p-xylene insolubles (a) and 12 to 22% by weight of 23&#xb0; C. p-xylene solubles (b), (2) the insolubles (a) having an isotactic pentad fraction of 95% or higher, a relaxation time (&#x3c4;) of 0.01 to 0.35 second at an angular frequency (&#x3c9;) of 10&#xb0;/sec when measured by melt viscoelastometry and a molecular weight distribution index (PDI) of 1 to 18 which is expressed by &#x3c9;/10&#x3c9;wherein &#x3c9;is an angular frequency at which a storage modulus (G') as measured by melt viscoelastometry is 2&#xd7;10Pa and &#x3c9;is an angular frequency at which a storage modulus (G&#x2032;) as measured by melt viscoelastometry is 2&#xd7;10Pa, and (3) the solubles (b) having an intrinsic viscosity [&#x3b7;] (in decalin at 135&#xb0; C.) of 3.3 dl/g or higher and an ethylene unit content of 43% by weight or smaller; (B) 0 to 10% by weight of a rubberlike elastomer; and (C) 10 to 30% by weight of tale. The automotive interior trims are produced by injection-molding the composition.

Propylene resin composition and interior automotive member comprising the same

The polypropylene-based resin composition of the invention consists basically of (a) a polypropylene resin or a block copolymer of propylene and ethylene of specified ethylene content specified in terms of the melt index and the isotacticity relative to the isotactic pentad of the propylene moiety and (b) a talc powder specified in terms of the average particle diameter and the average aspect ratio of particles. The resin composition has good blow-moldability and is capable of giving molded articles having excellent mechanical strengths and dimensional accuracy to be useful, for example, as a material of automobile bumper beams. The performance of the resin composition can be further improved when the composition is a ternary composition by partially replacing the component (a) with (a') a high-density polyethylene specified in terms of the melt index and a special parameter derived from the viscosity measurement or when the composition is a quaternary composition consisting of the components (a), (a') and (b) and an additional component (c) which is a rubbery elastomer, e.g., EPR, specified in terms of the complex viscosity.

Polypropylene-based resin composition

A polyolefin resin composition comprising from 30% to 96% by weight of a polyolefin, from 3% to 50% by weight of a fibrous inorganic filler selected from the group consisting of a magnesium hydroxide fiber, a magnesium oxide fiber, and a gypsum fiber having a mean fiber diameter of from 0.1 to 2 .mu.m and an aspect ratio of from 20 to 100 or a mixture of two or more of said inorganic fillers, and from 1% to 60% by weight of a thermoplastic elastomer. The said composition provides a molded material which has a good external appearance and is excellent in the impact strength, rigidity, and heat stability.

Polyolefin resin composition containing fibrous inorganic filler

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Ichihara, Japan

Ryuzo Tomomatsu