Propylene-based copolymer, process for producing the same and film comprising the same
US6573332B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Aug 27, 2001 |
| Grant date | Jun 3, 2003 |
| Priority date | — |
| Expiry date | Aug 27, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31909
- WIPO fieldMacromolecular chemistry, polymers
- WIPO sectorChemistry
Abstract
A propylene-based copolymer obtained by copolymerizing propylene with ethylene and/or an &agr;-olefins having 4 or more carbon atoms in the presence of a polymerization catalyst in a first step to produce a copolymer having a content of the &agr;-olefins of 1 mol % or more and less than 15 mol % and an ethylene content of 5 mol % or less in amount of 1 to 30% by weight as a copolymer component (A), and subsequently copolymerizing propylene with ethylene and/or an &agr;-olefins having 4 or more carbon atoms in a second step or later steps to produce a copolymer having a content of the &agr;-olefins of 15 to 30 mol % and an ethylene content of 5 mol % or less in amount of 70 to 99% by weight as a copolymer component (B).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.