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:
May. 20, 2003
Filed:
Jul. 22, 2002
Shyusei Ohya, Ichihara, JP;
Yuuichi Fujii, Ichihara, JP;
Shigeru Yao, Ichihara, JP;
Yukihiko Asano, Ichihara, JP;
Kimio Nakayama, Ichihara, JP;
Kenji Fukunaga, Ichihara, JP;
Ube Industries, Ltd., Ube, JP;
Abstract
A polyimide porous film obtained by drying and imidizing a polyimide precursor porous film which is substantially homogeneous on both sides, the polyimide porous film having pores on both sides wherein the pores all satisfy the conditions: 1) the difference in the mean pore size of both sides is less than 200% based on the smaller average value of the mean pore size, 2) the coefficient of variation for the pore size on each side is smaller than 70%, 3) the coefficient of variation for the pore centroid distance on each side is smaller than 50%, and 4) the mean pore size on each side is 0.05-5 &mgr;m.