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:
Nov. 30, 2004
Filed:
Jul. 06, 2001
Hidehiko Funaoka, Yokohama, JP;
Kotaro Takita, Yokohama, JP;
Norimitsu Kaimai, Yokohama, JP;
Shigeaki Kobayashi, Yokohama, JP;
Koichi Kono, Asaka, JP;
Tonen Chemical Corporation, Tokyo, JP;
Abstract
A microporous polyolefin membrane is formed by fine fibrils, comprising (A) a polyolefin having a weight-average molecular weight of 5×10 or more or (B) a composition containing component (A), connected to each other, and has micropores of 0.05 to 5 &mgr;m in average pore size and crystal lamellas of component (A) or (B) being in a specific orientation state. The membrane is produced by 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.