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. 26, 1993
Filed:
Jul. 07, 1989
Applicant:
Inventors:
Akira Miyake, Mishima, JP;
Yoshinori Yamamoto, Takatsuki, JP;
Assignee:
Hitachi Maxell, Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G11B / ; B05D / ; C23C / ; B32B / ;
U.S. Cl.
CPC ...
428 64 ; 428 65 ; 428480 ; 428900 ; 428323 ; 4284237 ; 428694 ; 427129 ; 2041922 ;
Abstract
A magnetic disc comprising a nonmagnetic substrate made of a synthetic resin film and at least one magnetic layer on the surface of the substrate has improved reliability when it having a dimensional shrinkage factor of not more than 0.04% in a radial direction after keeping the magnetic disc at 60.degree. C., 90% RH for 64 hours and then keeping it at room temperature for 72 hours.