Method for molding syndiotactic polypropylene
US5200131A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 2, 1991 |
| Grant date | Apr 6, 1993 |
| Priority date | — |
| Expiry date | Apr 2, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S526/943
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method for molding a polypropylene or a propylene copolymer having a syndiotactic structure which comprises the steps of melting, molding, if desired, quenching and then stretching a propylene homopolymer or a copolymer of propylene and a small amount of ethylene or another .alpha.-olefin which has a substantially syndiotactic structure, or a mixture of the same and a small amount of a polypropylene having a substantially isotactic structure. The molded and stretched article can be heated at a temperature of a molding temperature or more, while a load is applied to the article. Furthermore, the molded and stretched article, if desired, can be treated with a hydrocarbon vapor, while a load is applied to the article. The molded article obtained by the method of the present invention has a novel crystalline structure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.