Patent · US Expired

Formation of porous membranes by mechanical deformation

US4762657A · kind A · utility

10Cited by
17References
42Claims
0Family size

Assignee

Inventors

Key dates

Filing dateDec 12, 1985
Grant dateAug 9, 1988
Priority date
Expiry dateDec 12, 2005

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY10S264/47
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

This invention relates to a method for producing large area, controlled, uniform deformation of polymeric films which retards premature fracturing. The method includes a deformation step. Sulfonating and annealing the sulfonated deformed film are optional treatments of the method. Deformation can be achieved using pressing, peeling or rolling techniques. The deformed film is sulfonated utilizing sulfuric acid or fuming sulfuric acid. The product obtained using the inventive method results in a deformed film which has improved flow and entrance pressure characteristics compared to non-deformed film materials. The product can be used as a microfiltration membrane, ultrafiltration membrane or filter for various gas, vapor or liquid mixtures. The film may also serve as a porous substrate or other media for other types of fluid separation or purification.

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