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:
Jul. 05, 1988
Filed:
Apr. 08, 1986
Teruo Takahashi, Hachioji, JP;
Hirofumi Yoshikawa, Hachioji, JP;
Sadayoshi Miura, Yamato, JP;
Tamaki Kanai, Machida, JP;
Teijin Limited, Tokyo, JP;
Abstract
A polyester film having on at least one surface thereof a primer layer comprising a crosslinked product of a polyurethane having at least one functional group selected from a carboxyl group, a sulfo group, a hemisulfate group, and salts of these groups and a polyepoxy compound. The polyester film having a primer layer can be produced by coating an aqueous primer coating composition comprising a polyurethane having at least one of a carboxylic acid salt group, a sulfonic acid salt group and a hemisulfate salt group on at least one surface of a polyester film before its crystallization and orientation are completed, and thereafter completing the crystallization and orientation by subjecting the coated film to drying, stretching and heat-treatment, and is useful as a base film for magnetic recording media.