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:
May. 29, 1984
Filed:
Sep. 10, 1982
Thomas A Tweddle, Orleans, CA;
William L Thayer, Ottawa, CA;
Oleh Kutowy, North Gower, CA;
Srinivasa Sourirajan, Ottawa, CA;
Canadian Patents & Development Limited, Ottawa, CA;
Abstract
Polysulfone cast films, including polyethersulfone cast films, are partially gelled with mineral acid prior to or during the conventional water gelation to control the porosity of and improve the productivity of reverse osmosis and ultrafiltration membranes thus produced. The partial gelation may be carried out prior to the water gelation by contacting the cast film with the mineral acid in a gaseous or aqueous form and the gaseous form may be diluted with air. The partial gelation may, in different embodiments, be carried out simultaneously with the conventional gelation by dissolving the mineral acid in the gelation liquid.