The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 02, 1990
Filed:
Dec. 13, 1989
Applicant:
Inventor:
John E Cadotte, Minnetonka, MN (US);
Assignee:
Filmtec Corporation, Minneapolis, MN (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B01D / ;
U.S. Cl.
CPC ...
210639 ; 210651 ; 210652 ; 21050038 ;
Abstract
A reverse osmosis membrane having improved rejection of sulfuric acid and/or isopropanol is described. The membrane is prepared by treating a crosslinked, polyamide discriminating layer with an amine-reactive reagent selected from a carboxylic acid ester, a carboxylic acid anhydride, an amine-reactive organic halogen compound, an ethylenically unsaturated hydrocarbon, or a 1,3-propane sultone, at conditions whereby the passage of sulfuric acid in a 2 percent aqueous solution at a transmembrane pressure of 400 psi is reduced by at least 30 percent.