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:
Nov. 24, 1981
Filed:
Sep. 21, 1979
Stephen Z Jakabhazy, Weston, MA (US);
Leos J Zeman, Winchester, MA (US);
Abcor, Inc., Wilmington, MA (US);
Abstract
A microporous polymeric membrane is made by preparing a polymer-casting solution, casting a thin film of the casting solution on a support base, allowing partial evaporation of the solvent from the cast film for a predetermined period of time and contacting the partially evaporated film with a leaching liquid to provide the microporous membrane. A membrane with particularly good mechanical strength and hydrophilic properties is formed when the casting solution comprises a vinylidene fluoride polymer and from about 35 to about 85% by weight of a vinyl acetate polymer; and when the acetate polymer is hydrolyzed after the leaching step to convert the acetate groups to hydroxyl groups.