Process for producing microporous ultra-high-molecular-weight polyolefin membrane
US4873034A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jul 22, 1988 |
| Grant date | Oct 10, 1989 |
| Priority date | — |
| Expiry date | Jul 22, 2008 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E60/10
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A process for producing a relatively thick microporous ultra-high-molecular-weight polyolefin membrane, including the steps of: (1) preparing a solution of an ultra-high-molecular-weight polyolefin having a weight-average molecular weight of 5.times.10.sup.5 or more; (b) extruding the solution from a die while rapidly cooling it in advance to its gelation temperature or below, thereby forming a gel-like sheet; (c) removing at least 10 wt % of the solvent from the gel-like sheet so that the gel-like sheet contains 10 to 90 wt % of the ultra-high-molecular-weight polyolefin; (d) stretching the gel-like sheet at a temperature equal to or lower than that which is 10.degree. C. above the melting point of the ultra-high-molecular-weight polyolefin; and (e) removing the residual solvent from the stretched product.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.