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. 28, 2012
Filed:
Apr. 09, 2007
Kotaro Takita, Tochigi-ken, JP;
Junko Takita, Legal Representative, Tochigi-ken, JP;
Shintaro Kikuchi, Saitama-ken, JP;
Kotaro Takita, Tochigi-ken, JP;
Junko Takita, legal representative, Tochigi-ken, JP;
Shintaro Kikuchi, Saitama-ken, JP;
Toray Tonen Specialty Separator Godo Kaisha, Tochigi, JP;
Abstract
A multi-layer, microporous polyolefin membrane comprising first microporous layers constituting at least both surface layers, and at least one second microporous layer disposed between both surface layers, the first microporous layer comprising a first polyethylene resin containing 8% or more by mass of ultra-high-molecular-weight polyethylene having a weight-average molecular weight of 1×10or more, the second microporous layer comprising a second polyethylene resin containing 7% or less by mass of the ultra-high-molecular-weight polyethylene, and having a structure in which a pore diameter distribution curve obtained by mercury intrusion porosimetry has at least two peaks, and the total thickness of the first microporous layers being 15-60% per 100% of the total thickness of the first and second microporous layers.