Microporous polyolefin film and process for producing the same
US6824865B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 6, 2001 |
| Grant date | Nov 30, 2004 |
| Priority date | — |
| Expiry date | Jul 6, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/249991
- WIPO fieldChemical engineering
- WIPO sectorChemistry
Abstract
A microporous polyolefin membrane is formed by fine fibrils, comprising (A) a polyolefin having a weight-average molecular weight of 5×105 or more or (B) a composition containing component (A), connected to each other, and has micropores of 0.05 to 5 &mgr;m in average pore size and crystal lamellas of component (A) or (B) being in a specific orientation state. The membrane is produced by extruding a solution of component (A) or (B) in a solvent, into a gel-like formed article; thermally setting the article, with or without stretching, at least at the crystal dispersion temperature of component (A) or (B), but at melting point of component (A) or (B) plus 30° C. or lower; and removing the solvent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.