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:
Apr. 08, 2003
Filed:
Mar. 07, 2000
Hirotoshi Kizumoto, Otsu, JP;
Takeshi Yatsuka, Otsu, JP;
Chikara Sugitawa, Otsu, JP;
Kuniyuki Doi, Otsu, JP;
Toyo Boseki Kabushiki Kaisha, Osaka, JP;
Abstract
A magnetic recording medium possessing a magnetic layer formed by application onto a non-magnetic support, of a magnetic coating containing magnetic particles dispersed in a binder which contains a polyurethane resin, together with carbon black particles at 5% by weight or higher, based on the weight of the magnetic particles. The polyurethane resin to be used herein is composed of: (a) a polyester polyol having a molecular weight of 2000 or lower and containing at least one selected from the group consisting of aromatic dibasic acids and alicyclic dibasic acids at a ratio of 90 mol % or higher of acid components; (b) a high molecular weight polyol having a molecular weight of 5000 or lower, which is at least one selected from the group consisting of (b1) polyester polyols each containing an aliphatic dibasic acid at a ratio of 90 mol % or higher of acid components, (b2) polylactones, (b3) polyester polyols, and (b4) polycarbonate polyols; (c) an organic diisocyanate compound; and (d) an optional compound having a molecular weight of 500 or lower and containing at least two functional groups in one molecule, which are reactive with isocyanate groups.