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:
Sep. 16, 1986
Filed:
Oct. 01, 1984
Koji Kaneda, Dothan, AL (US);
Masayoshi Sugiyama, Miyagi, JP;
Sony Corporation, Tokyo, JP;
Abstract
A magnetic recording medium is disclosed, in which a magnetic layer is formed on one surface of the non-magnetizable substrate and a back coating layer consisting essentially of a binder and a non-magnetizable pigment is formed on the other surface of the substrate. In the back coating layer, more than 80 weight percent of the binder is a polyurethane resin or a polyester resin having hydrophilic polar groups. The back coating layer also contains carbon black for preventing electrostatic charging and pigments with Mohs hardness higher than 5 for improving durability. The carbon black to the pigments weight ratio is set to be in the range of 95:5 to 60:40.