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. 09, 2017
Filed:
Jul. 25, 2014
Toray Battery Separator Film Co., Ltd., Nasushiobara, JP;
Kotaro Takita, Nasushiobara, JP;
Yoichi Matsuda, Nasushiobara, JP;
Sadakatsu Suzuki, Nasushiobara, JP;
Abstract
A method of producing microporous membranes includes stretching a multi-layer layer extrudate having first and second layers, the first layer including a first polyolefin and a first diluent, and the second layer including a second polyolefin and a second diluent, the second polyolefin including polypropylene in an amount of 1.0 wt. % to 40.0 wt. %, the polypropylene having an Mw>0.9×10and a ΔHm≧100.0 J/g; removing at least a portion of the diluents to produce a dried membrane having a first length and a first width; stretching the membrane by a first magnification factor of 1.1 to 1.5 and stretching the membrane by a second magnification factor of 1.1 to 1.3; and reducing the width.