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:
Mar. 20, 1979
Filed:
Aug. 15, 1977
Applicant:
Inventors:
Assignee:
Canadian Patents and Development Limited, Ottawa, CA;
Attorneys:
Primary Examiner:
Int. Cl.
CPC ...
B01D / ; B01D / ; B29D / ;
U.S. Cl.
CPC ...
2105 / ; 264 41 ; 264331 ;
Abstract
A process for preparing ultra-filtration membranes and the product thereof, in which a selected cellulosic-ester polymer solution is cast into a thin film, at about ambient temperature, partially dried and immersed in a gelation bath at -20 .degree. to +30.degree. C. The gelation bath contains a sufficient percentage by volume of ethyl alcohol or other organic polar compound to ensure that a flux rate in excess of the initial minimum is achieved. In this way, ultra-filtration membranes having water flux rates selected from within the approximate range 14-10,000 gals./sq.ft./day at 100 psig and a molecular weight cut off above about 15,000, can be produced.