Patent · US Expired

Polyethylene microporous membrane of ultra high molecular weight

US4588633A · kind A · utility

42Cited by
1References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 29, 1985
Grant dateMay 13, 1986
Priority date
Expiry dateApr 29, 2005

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10T428/249978
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

A polyethylene microporous membrane having a thickness of at most 10 .mu.m, a breaking strength of at least 200 kg/cm.sup.2 and a porosity of at least 30% is produced by heating and dissolving polyethylene having a weight average molecular weight of at least 5.times.10.sup.5 in a solvent, forming a gel sheet from the resulting solution, subjecting the gel sheet to a solvent removal treatment to adjust the amount of the solvent in the gel sheet to 10 to 80% by weight, heating and stretching the sheet and then removing the residual solvent therefrom.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.