Method of producing polypropylene tapes
US6758994B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 2002 |
| Grant date | Jul 6, 2004 |
| Priority date | — |
| Expiry date | Oct 30, 2022 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2023/12
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
The present invention relates to a process for making polymer tapes utilizing metallocene catalysts. An isotactic propylene polymer is prepared by polymerizing propylene in the presence of an isospecific metallocene catalyst. The resulting polypropylene is heated, extruded and withdrawn as a sheet. The sheet is then slit longitudinally into tape segments and drawn in the longitudinal direction to a draw ratio of at least about 4.5:1 to produce an oriented tape. It has been found that these polypropylene tapes have different characteristics than those polypropylene tapes produced using Ziegler-Natta catalyst drawn at the same draw ratios.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.