Polypropylene composition and the film thereof
US5654372A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 8, 1996 |
| Grant date | Aug 5, 1997 |
| Priority date | — |
| Expiry date | Mar 8, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08F297/083
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A polypropylene composition comprising a melt-kneaded polyprolylene composition obtained, using Zieglar-Natta catalyst, by polymerizing a monomer comprising propylene to form a polymer comprising polypropylene (component A) in amount of from 60 to 80% by weight to the total polymer amount in substantially the absence of an inert solvent in a 1st step and then polymerizing a mixture of ethylene content of from 20 to 50% by weight (component B) in a vapor phase to form an ethylene-propylene copolymer (component B) in amount of from 20 to 40% by weight to the total polymer amount in a 2nd step, said polypropylene composition being such that the intrinsic viscosity of component B ([.eta.]B) is at least 2.0 dl/g and the ratio ([.eta.]B/[.eta.]A) of the intrinsic viscosity of the component B to the intrinsic viscosity of the component A ([.eta.]A) is 1.8 or less and the melt flow rate of the polypropylene composition after melt-kneaded being 0.5 to 10 g/10 minutes.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.