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. 13, 1986
Filed:
Apr. 29, 1985
Applicant:
Inventors:
Koichi Kono, Saitama, JP;
Shoichi Mori, Saitama, JP;
Kenji Miyasaka, Saitama, JP;
Jyoichi Tabuchi, Saitama, JP;
Assignee:
Toa Nenryo Kogyo Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
B32B / ;
U.S. Cl.
CPC ...
428220 ; 4283155 ; 521143 ;
Abstract
A polyethylene microporous membrane having a thickness of at most 10 .mu.m, a breaking strength of at least 200 kg/cm.sup.2 and a porosity of at least 30% is produced by heating and dissolving polyethylene having a weight average molecular weight of at least 5.times.10.sup.5 in a solvent, forming a gel sheet from the resulting solution, subjecting the gel sheet to a solvent removal treatment to adjust the amount of the solvent in the gel sheet to 10 to 80% by weight, heating and stretching the sheet and then removing the residual solvent therefrom.