Polypropylene composition and process for producing the same
US6271310A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 15, 1999 |
| Grant date | Aug 7, 2001 |
| Priority date | — |
| Expiry date | Oct 15, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08L23/16
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A polypropylene composition which contains 0.01 to 5 parts by weight of an olefin (co)polymer (a) having an intrinsic viscosity of 15 to 100 dl/g, 100 parts by weight of a propylene homopolymer (b) having an intrinsic viscosity of 0.2 to 10 dl/g, and 28 to 300 parts by weight of an ethylene/propylene copolymer (c) having an intrinsic viscosity of 0.2 to 10 dl/g, and in which the ratio of the melt flow rate of the homopolymer (b) to that of the copolymer (c), MFR.sub.PP /MFR.sub.RC, is 0.3 to 4 and the product of the ratio of the intrinsic viscosity of the copolymer (c) to that of the homopolymer (b), [.eta.].sub.RC /[.eta.].sub.PP, and the weight ratio of the amount of the homopolymer (b) to that of the copolymer (c), W.sub.PP /W.sub.RC, is in the range of from 0.2 to 3.0. The composition has high melt tension, high crystallization temperature, and excellent thermal stability, and yields a molded article having excellent transparency, reduced molding shrinkage, and excellent resistance to whitening by impact or bending.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.