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:
Dec. 13, 2011
Filed:
Oct. 27, 2004
Hidehiko Funaoka, Yokohama, JP;
Kotaro Takita, Yokohama, JP;
Norimitsu Kaimai, Yokohama, JP;
Shigeaki Kobayashi, Yokohama, JP;
Koichi Kono, Asaka, JP;
Hidehiko Funaoka, Yokohama, JP;
Kotaro Takita, Yokohama, JP;
Norimitsu Kaimai, Yokohama, JP;
Shigeaki Kobayashi, Yokohama, JP;
Koichi Kono, Asaka, JP;
Toray Tonen Specialty Separator Godo Kaisha, Nasushiobara, JP;
Abstract
A method for producing a microporous polyolefin membrane formed by fine fibrils, the membrane comprising (A) a polyolefin having a weight-average molecular weight of 5×10or more or (B) a composition containing Component (A), connected to each other, and having micropores of 0.05 to 5 μm in average pore size and crystal lamellas of Component (A) or (B) being in a specific alignment state. The method includes extruding a solution of Component (A) or (B) in a solvent into a gel-like formed article; thermally setting the article, with or without stretching, at least at the crystal dispersion temperature of Component (A) or (B), but at melting point of Component (A) or (B) plus 30° C. or lower; and removing the solvent.