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:
Feb. 28, 2012
Filed:
Apr. 16, 2009
Applicants:
Yuuichi Abe, Osaka, JP;
Masaaki Mori, Osaka, JP;
Kousei Takiishi, Osaka, JP;
Inventors:
Assignee:
Nitto Denko Corporation, Osaka, JP;
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
B01D 53/22 (2006.01);
U.S. Cl.
CPC ...
Abstract
First, a mixture of a polytetrafluoroethylene fine powder and a liquid lubricant into a sheet-form body extending in a first direction. Next, the liquid lubricant is removed from the sheet-form body. Then, the sheet-form body is stretched by a factor of 40 to 250 in the longitudinal direction at a temperature equal to or higher than a melting point of polytetrafluoroethylene, and the stretched sheet-form body is further stretched by a factor of 3 to 40 in the width direction. Thus, a highly air-permeable porous polytetrafluoroethylene membrane is obtained.