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:
Aug. 10, 1993
Filed:
Jul. 22, 1992
Applicant:
Inventors:
Shinji Tanaru, Osaka, JP;
Osamu Tanaka, Osaka, JP;
Hirofumi Nishibayashi, Osaka, JP;
Osamu Inoue, Osaka, JP;
Katsutoshi Yamamoto, Osaka, JP;
Toshio Kusumi, Osaka, JP;
Assignee:
Daikin Industries Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B32B / ; D02J / ;
U.S. Cl.
CPC ...
428131 ; 2642888 ; 264D / ; 4283155 ; 4283157 ; 428422 ; 428286 ;
Abstract
A polytetrafluoroethylene porous film, which is prepared by stretching a semisintered polytetrafluoroethylene material and heating the stretched material at a temperature higher than the melting point of sintered polytetrafluoroethylene, has an area ratio of fibrils to nodes of from 99:1 to 75:25, an average fibril diameter of from 0.05 to 0.2 .mu.m, a largest node area of not larger than 2 .mu.m.sup.2 and an average pore size of from 0.2 to 0.5 .mu.m and achieves low pressure loss.