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. 01, 1980
Filed:
Dec. 12, 1977
Kwang C Chao, Palo Alto, CA (US);
Mark C Porter, Pleasanton, CA (US);
Nuclepore Corporation, Pleasanton, CA (US);
Abstract
A method for forming a microporous sheet of fluorocarbon polymer (e.g., polytetrafluoroethylene). An aqueous dispersion of polytetrafluoroethylene which includes a dissolved water-soluble, crystallizable metallic organic salt, preferably sodium benzoate, is formed into a sheet. Water is evaporated from an exposed surface of the sheet to grow crystals of the organic salt dispersed throughout the sheet. Then, the sheet is sintered. After cooling, the salt crystals are leached from the sheet by dissolution in water to leave a porous structure suitable for such uses as a filtration membrane or as a separation barrier in batteries or electrolytic cells.