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:
Apr. 25, 1989
Filed:
Jun. 13, 1988
Applicant:
Inventors:
John E Cadotte, Minnetonka, MN (US);
David R Walker, Kilmarnock, GB;
Assignee:
The Dow Chemical Company, Midland, MI (US);
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C02F / ;
U.S. Cl.
CPC ...
210654 ;
Abstract
A novel water softening membrane and process for making the same is described. The membrane can be prepared by treating a polyamide reverse osmosis membrane with a strong mineral acid followed by treatment with a rejection enhancing agent. The resulting membrane at transmembrane pressures of 50 psi can attain a magnesium sulfate rejection with a 0.2 percent aqueous solution of more than 90 percent with a water flux of more than 15 gallons per square foot per day.