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:
May. 16, 1989
Filed:
Jan. 28, 1986
Kenji Sumiya, Osaka, JP;
Yoshinori Yamamoto, Osaka, JP;
Shigeo Aoyama, Kyoto, JP;
Yoji Takeuchi, Osaka, JP;
Hitachi Maxell, Ltd., Osaka, JP;
Abstract
A magnetic recording medium comprising a substrate and a magnetic layer coated on the substrate which comprises a magnetic powder and a binder resin, wherein said binder resin comprises a modified polymer selected from the group consisting of a polymer having a backbone chain comprising a vinyl chloride/vinyl acetate/vinyl alcohol terpolymer and a polymer having a backbone chain comprising polyurethane to both of which a phosphoric acid group of the formula: ##STR1## wherein A is a hydrogen atom, an alkali metal atom or a hydrocarbon group, and n is 0 or 1 is bonded, the magnetic layer having improved surface smoothness, improved durability and excellent electromagnetic conversion characteristics particularly in the short wavelength range.