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:
Oct. 26, 2010
Filed:
Aug. 19, 2003
Michio Tsuyumoto, Himeji, JP;
Yo Yamato, Himeji, JP;
Michio Tsuyumoto, Himeji, JP;
Yo Yamato, Himeji, JP;
Daicel Chemical Industries, Ltd., Osaka-shi, JP;
Abstract
A porous film of the invention is a porous film having a large number of continuous micropores. The film has a thickness of 5 to 200 μm, has an average surface pore size A of 0.01 to 10 μm, an average surface porosity C, and has an average inside pore size B and an average inside porosity D. The ratio A/B of A to B is 0.3 to 3. The porous film is produced by casting a polymer solution containing a polymer onto a substrate to form a film and subjecting the film to phase conversion to thereby form a porous film. In the method, the polymer constituting the porous film has a surface tension Sa [mN/m], the substrate has a surface tension Sb [mN/m], and Sa and Sb satisfy the following condition: Sa−Sb≧−10.