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:
Apr. 29, 2014
Filed:
Aug. 29, 2008
Shintaro Kikuchi, Saitama-ken, JP;
Junko Takita, Tochigi-ken, JP;
Shintaro Kikuchi, Saitama-ken, JP;
Kotaro Takita, Tochigi-ken, JP;
Toray Battery Separator Film Co., Ltd, Tochigi, JP;
Abstract
The invention relates to polyolefin membranes and membrane precursors comprising polyethylene and polypropylene. The polyolefin membrane can be a microporous polyolefin membrane comprising a first microporous layer and at least one second microporous layers where the first and second layers contain polypropylene and polyethylene, and the amount of polyethylene in the first layer is at least about 80 wt. % and the amount of polyethylene in the second layer is at least about 50 wt. %. The amount of polyethylene is higher in the first microporous layer than in the second microporous layer, and the total amount of the polyethylene in the first and second microporous layers is at least about 61 wt. %, based on the weight of the multi-layer, microporous polyolefin membrane.