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. 18, 2014
Filed:
Feb. 24, 2011
Saori Tanizaki, Osaka, JP;
Norihiro Yamamoto, Osaka, JP;
Yasushi Nakagiri, Kyoto, JP;
Yasuyuki Shibano, Nara, JP;
Saori Tanizaki, Osaka, JP;
Norihiro Yamamoto, Osaka, JP;
Yasushi Nakagiri, Kyoto, JP;
Yasuyuki Shibano, Nara, JP;
Panasonic Corporation, Osaka, JP;
Abstract
A separator for a battery includes a porous polymer film having a first surface and a second surface opposite to the first surface, wherein the first surface has openings distributed thereon communicating with pores of the porous polymer film, and the ratio of the total area of the openings to the area of the first surface is 89% or more and 96% or less. The diameters of the openings may be within the range of 0.8 μm or more and 40 μm or less. A region with a predetermined thickness including at least the first surface of the porous polymer film preferably includes at least one selected from the group consisting of polypropylene, and a copolymer of propylene and another copolymerizable monomer.