Patent · US Expired

Polyolefin microporous film and method for preparing the same

US6245272A · kind A · utility

45Cited by
3References
3Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 1, 2000
Grant dateJun 12, 2001
Priority date
Expiry dateDec 1, 2020

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02E60/10
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

It is an object of the present invention to provide a microporous polyolefin membrane, high in elongation and porosity, low in shrinkage, and capable of improving battery characteristics, safety and productivity, when used for battery separators. The microporous polyolefin membrane of the present invention comprises (A) an ultra-high-molecular-weight polyolefin having a weight-average molecular weight of 5.times.10.sup.5 or more, or (B) a composition containing an ultra-high-molecular-weight polyolefin having a weight-average molecular weight of 5.times.10.sup.5 or more, and having a porosity of 45 to 95%, elongation at break of 300% or more, bubble point exceeding 980 KPa and thermal shrinkage in the TD direction of 3% or less. The present invention also provides a method for producing the above microporous polyolefin membrane.

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