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. 17, 1989
Filed:
Mar. 13, 1987
Hermann Dallman, Wiesbaden-Naurod, DE;
Hartmut Hensel, Schlangenbad, DE;
Werner Schafer, Hofheim, DE;
Hoechst Aktiengesellschaft, , DE;
Abstract
A coextruded, biaxially draw-oriented, multi-layer polyester film as a base film for magnetic tape is described, whose characteristics are that the total thickness of the multi-layer film is no more than 10 .mu.m, the surface roughness of the base film on the side intended for the application of an information-carrying coating has an R.sub.a value (DIN 4768) of less than or equal to 0.010 .mu.m and the surface roughness of the opposite side of the base film which is not intended for application of an information-carrying coating, has an R.sub.a value of greater than 0.010 .mu.m and that the film has an E-modulus in the machine direction of greater than or equal to 6500 N/mm.sup.2.