Patent · US Expired

Polypropylene resin composition and injection-molded article thereof

US6251997A · kind A · utility

50Cited by
0References
42Claims
0Family size

Assignee

Inventors

Key dates

Filing dateFeb 3, 2000
Grant dateJun 26, 2001
Priority date
Expiry dateFeb 3, 2020

Classification

  • Technology area (CPC C)Chemistry; Metallurgy
  • CPC primaryC08L2205/02
  • WIPO fieldMacromolecular chemistry, polymers
  • WIPO sectorChemistry

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, PA1 <<1>> an isotactic pentad fraction (mmmm-fraction), determined by .sup.13 C-NMR, of at least 96.5% and PA1 <<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.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.