Patent · US Expired

Positively charged polyvinylidene fluoride membrane

US5282971A · kind A · utility

75Cited by
19References
29Claims
0Family size

Assignee

Inventors

Key dates

Filing dateMay 11, 1993
Grant dateFeb 1, 1994
Priority date
Expiry dateMay 11, 2013

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB01D2323/385
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

A filter medium comprising a microporous polyvinylidene fluoride membrane and a polymer containing positively charged quaternary ammonium groups covalently bonded to the membrane, and a method of using the filter medium to treat a composition, particularly a biological or pharmaceutical composition such as an ophthalmic composition.

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