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:
Mar. 15, 1983
Filed:
Oct. 05, 1981
Sueo Machi, Takasaki, JP;
Isao Ishigaki, Maebashi, JP;
Takanobu Sugo, Gunma, JP;
Kazuo Murata, Takatsuki, JP;
Shiro Tanso, Takatsuki, JP;
Keizi Senoo, Takasaki, JP;
Japan Atomic Energy Research Inst., Tokyo, JP;
Yuasa Battery Co., Ltd., Osaka, JP;
Abstract
A novel process for the production of a separator for use in a cell to prevent the short-circuiting of positive active material and negative active material comprises irradiating a polyolefin film 150 .mu.m or less thick with ionizing radiation at a dose rate of 5.times.10.sup.4 -10.sup.7 rads/sec. to give a total dose of 1 Mrad or more, contacting the irradiated film with an aqueous solution of a terminally unsaturated monomer such as acrylic acid, methacrylic acid and the like at a temperature of 10.degree. C.-60.degree. C. to thereby cause grafting of the monomer onto the polyolefin film before the grafted polymer film is treated with an aqueous alkaline solution to finally obtain the separator for use in a cell, which is substantially improved in that it shows low electrical resistance and is excellent both in its acid resistance and mechanical strength.