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:
Aug. 28, 1990
Filed:
Oct. 05, 1988
Iwao Okazaki, Mukou, JP;
Koichi Abe, Kyoto, JP;
Shoji Nakajima, Ootsu, JP;
Kiyohiko Ito, Ootsu, JP;
Satoru Nishino, Ootshu, JP;
Hidehito Minamizawa, Ootsu, JP;
Toray Industries, Inc., , US;
Abstract
A biaxially oriented polyester film suited as a substrate for magnetic recording media. The film comprises a polyester and inert particles and has at least one surface with protrusions formed by the existence of the inert particles. The surface has a parameter of surface topography .sqroot.(.beta./.sigma.) of 0.1 to 0.7. The average distance between adjacent protrusions is not more than 20 um and the coefficient of friction of the surface and the parameter of surface topography satisfies the following equations (1) and (2): ##EQU1## wherein y is the coefficient of friction, .beta. is mean flatness of protrusions and .sigma. is standard deviation of height distribution of protrusions.