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. 12, 2014
Filed:
Sep. 14, 2006
Kotaro Takita, Nasushiobara, JP;
Shintaro Kikuchi, Saitama, JP;
Kazuhiro Yamada, Nasushiobara, JP;
Teiji Nakamura, Suginami-ku, JP;
Koichi Kono, Asaka, JP;
Kotaro Takita, Nasushiobara, JP;
Shintaro Kikuchi, Saitama, JP;
Kazuhiro Yamada, Nasushiobara, JP;
Teiji Nakamura, Suginami-ku, JP;
Koichi Kono, Asaka, JP;
Toray Battery Separator Film Co., Ltd, Tochigi, JP;
Abstract
A microporous polyethylene membrane made of a polyethylene resin having a ratio (mass-average molecular weight/number-average molecular weight) of 5 to 300 and comprising 1% or more by mass of ultra-high-molecular-weight polyethylene having a mass-average molecular weight of 7×10or more, the microporous polyethylene membrane comprising (a) a coarse-structure layer having an average pore diameter of more than 0.04 μm, which is formed on at least one surface, and (b) a dense-structure layer having an average pore diameter of 0.04 μm or less, an area ratio of the coarse-structure layer to the dense-structure layer in a membrane cross section being 0.1 to 0.8.