Method for preparing molded articles of syndiotactic polypropylene
US5759469A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 25, 1996 |
| Grant date | Jun 2, 1998 |
| Priority date | — |
| Expiry date | Sep 25, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/26
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A molded article of a syndiotactic polypropylene having excellent transparency in which a melting point attributed to the polypropylene having the syndiotactic structure measured at a heating rate of 10.degree. C./minute by differential scanning thermal analysis is represented by a substantially single peak, the aforesaid molded article being prepared by heating, melting and then hot-molding a homopolymer of propylene or a copolymer of propylene and a small amount of another olefin, which have a substantially syndiotactic structure, or a mixture of the homopolymer or the copolymer and a small amount of a polypropylene having a substantially isotactic structure, followed by quenching, or, after these steps, additionally subjecting the above molded article to a heat treatment at a temperature of less than its melting point. A method for preparing the above molded article is also disclosed here.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.