Process of making polyprophylene fibers
US5624621A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Aug 24, 1995 |
| Grant date | Apr 29, 1997 |
| Priority date | — |
| Expiry date | Aug 24, 2015 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/2931
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A fiber excellent in strength and having an average size of 10,000-0.1 denier can be obtained by extruding a new material composed mainly of a polypropylene having a syndiotactic pentad fraction of 0.7 or more and optionally stretching the resulting extruded material. By using as the raw material a composition consisting of two kinds of polypropylenes each having an intrinsic viscosity .eta..sub.1 or .eta..sub.2, the log(.eta..sub.2 /.eta..sub.1) being more than 0.05 or less than -0.05, and a syndiotactic pentad traction of 0.7 or more at a weight ratio of 95:5-5:95 or a composition consisting of at least 50 parts by weight of a syndiotactic polypropylene having the intrinsic viscosity .eta..sub.1 and a syndiotactic pentad fraction of 0.7 or above and at most 50 parts by weight of an isotactic polypropylene having the intrinsic viscosity .eta..sub.2, the extrudability is improved and the fiber stretching conditions are broadened.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.