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:
Jan. 05, 1993
Filed:
Apr. 18, 1991
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Abstract
A magnetic recording medium improved in electromagnetic characteristics, running durability and running properties is disclosed, comprising a non-magnetic support and at least one magnetic layer formed thereon, said magnetic layer having a ferromagnetic powder dispersed in a binder, wherein said magnetic layer contains at least one member selected from the group consisting of an aromatic phosphoric acid or a derivative thereof, an aromatic phosphonic acid or a derivative thereof, and an aromatic sulfonic acid or a derivative thereof, and wherein said ferromagnetic powder has a pH of at least 7, and said binder is a vinyl chloride copolymer having an epoxy group and a hydroxyl group attached to an alkyl chain group. Also, a method for producing a magnetic recording medium is disclosed which comprises the steps of kneading and dispersing a ferromagnetic powder having a pH of at least 7, at least one member selected from the group consisting of an aromatic phosphoric acid or a derivative thereof, an aromatic phosphonic acid or a derivative thereof, and an aromatic sulfonic acid or a derivative thereof, and a vinyl chloride copolymer having an epoxy group and a hydroxyl group attached to an alkyl chain group, together with a solvent; and then optionally adding at least one additive thereto, and mixing to prepare a magnetic coating; and then applying the resulting magnetic coating to a non-magnetic support; drying, calendering and then heat treating.