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. 18, 1995
Filed:
May. 11, 1993
Kazuko Hanai, Kanagawa, JP;
Fuji Photo Film Co., Ltd., Kanagawa, JP;
Abstract
Disclosed is a magnetic recording medium comprising, a non-magnetic support having thereon (i) a lower non-magnetic layer comprising a non-magnetic powder and a binder, and (ii) an upper magnetic layer comprising a ferromagnetic powder and a binder, wherein an extract, obtained by extracting with tetrahydrofuran the binder present in the area between the outer surface of the upper magnetic layer and a position 0.1 .mu.m in depth from the outer surface, has a weight-average molecular weight of 15,000 or more, and wherein the reaction ratio of the curing agent reacted with the binder in the area between the outer surface of the upper magnetic layer and a position 0.1 .mu.m in depth from the outer surface is at least 1.3 times as much as the reaction ratio of the curing agent reacted with the binder containing a polyurethane in the lower nonmagnetic and upper magnetic layers as a whole. Also disclosed is a process for making this magnetic recording medium.