Patent · US Expired

Semipermeable membranes

US4828708A · kind A · utility

21Cited by
1References
8Claims
0Family size

Assignee

Inventor

Key dates

Filing dateSep 28, 1987
Grant dateMay 9, 1989
Priority date
Expiry dateSep 28, 2007

Classification

  • Technology area (CPC B)Performing Operations; Transporting
  • CPC primaryB01D71/56
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

A reverse osmosis membrane with excellent nitrate rejection that is particularly suitable for point-of-use drinking water purposes. The reverse osmosis membrane is a composite material comprising a porous support layer and an ultrathin polyamide desalinizing layer which is the interfacial condensation reaction product of (a) meta-phenylenediamine and (b) a mixture of a major portion of isophthaloyl chloride and a minor proportion of trimesoyl chloride.

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