Patent Number: 6,251,997

Title: Polypropylene resin composition and injection-molded article thereof

Abstract: A polypropylene resin composition, which is light weighing, has very high values for the stiffness and heat resistance and is superior in the scratch-proof property with better moldability upon molding and which can be injection-molded into formed articles without occurrence of cracking, comprising 5-25% by weight of a higher molecular weight polypropylene (A) having an intrinsic viscosity [.eta.], determined in decalin at 135.degree. C., in the range from 6 to 11 dl/g and 95-75% by weight of a lower molecular weight polypropylene (B) having an intrinsic viscosity [.eta.], determined in decalin at 135.degree. C., in the range from 0.6 to 1.6 dl/g, wherein the said resin composition has the following charactristic features <<1>> and <<2>>, namely, <<1>> an isotactic pentad fraction (mmmm-fraction), determined by .sup.13 C-NMR, of at least 96.5% and <<2>> a molecular weight distribution value expressed by Mw/Mn (weight-average molecular weight/number-average molecular weight), determined by gel permeation chromatography (GPC), of at least 8.

Inventors: Imai; Tadashi (Ichihara, JP), Hashimoto; Mikio (Sakai, JP), Harima; Shigeru (Takaishi, JP)

Assignee: Grand Polymer Co Ltd

International Classification: C08L 23/00 (20060101); C08L 23/10 (20060101); C08L 023/00 (); C08L 023/10 ()

Expiration Date: 06/26/2018