Patent · US Expired

Uniform polyvinylidene difluoride membranes

US5198505A · kind A · utility

5Cited by
5References
6Claims
0Family size

Assignee

Inventors

Key dates

Filing dateApr 11, 1991
Grant dateMar 30, 1993
Priority date
Expiry dateApr 11, 2011

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB01D71/34
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

A heat-treated, hydrophobic, polyvinylidene difluoride membrane is provided having uniform crystallinity as evidenced by a difference in crystallinity over the membrane of less than about 10 percent. Also provided is a hydrophilic, polyvinylidene difluoride membrane prepared from a heat-treated, hydrophobic, polyvinylidene difluoride membrane which remains hydrophilic after heating to a temperature as high as about 121.degree. C.

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