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. 14, 1981
Filed:
Jan. 18, 1980
Warren H Philipp, North Olmsted, OH (US);
Li-Chen Hsu, Westlake, OH (US);
Dean W Sheibley, Sandusky, OH (US);
Abstract
A method of producing a cross-linked polyvinyl alcohol structure, such as a battery separator membrane or electrode envelope. An aqueous solution of a film-forming polyvinyl alcohol is admixed with an aldehyde cross-linking agent at basic pH to inhibit cross-linking. The cross-linking agent, preferably a dialdehyde such as glutaraldehyde, is used in an amount of from about 1/2 to about 20% of the theoretical amount required to cross-link all of the hydroxyl groups of the polymer. The aqueous admixture is formed into a desired physical shape, such as by casting a sheet of the solution. The sheet is then dried to form a self-supporting film. Cross-linking is then effected by immersing the film in aqueous acid solution. The resultant product has excellent properties for use as a battery separator, including a low electrical resistivity, the value of which is principally determined by the amount of cross-linking which is easily and closely controlled by the amount of cross-linking agent added to the polymer.