Microporous polyolefin membrane and method of producing same
US5051183A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 20, 1990 |
| Grant date | Sep 24, 1991 |
| Priority date | — |
| Expiry date | Sep 20, 2010 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY02E60/10
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A microporous polyolefin membrane made of a polyolefin composition containing 1 weight % or more of an ultra-high-molecular-weight polyolefin having a weight-average molecular weight of 7.times.10.sup.5 or more and having a weight-average molecular weight/number-average molecular weight ratio of 10-300, the microporous membrane having a thickness of 0.1-25 .mu.m, a porosity of 35-95%, an average pore diameter of 0.001-0.2 .mu.m and a breaking strength of 0.2 kg or more per 15 mm width is produced by (a) preparing a solution comprising 10-50 weight % of the polyolefin composition and 50-90 weight % of a solvent; (b) extruding the solution through a die; (c) cooling the extruded solution to form a gel-like article; (d) stretching the gel-like article at a temperature equal to or lower than a melting point of the polyolefin composition +10.degree. C; and (e) removing the remaining solvent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.