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. 31, 1994
Filed:
Feb. 12, 1992
Masami Etchu, Yokohama, JP;
Hisashi Hamano, Sagamihara, JP;
Masahiro Hosoi, Tokyo, JP;
Yasuhiro Saeki, Sagamihara, JP;
Teijin Limited, Osaka, JP;
Abstract
A magnetic tape for audio cassettes wherein a magnetic layer is provided on base film characterized in that the a base film, is biaxially oriented polyethylene-2,6-naphthalate film having a Young's modulus in the longitudinal direction of 850 Kg/mm.sup.2 or more, a Young's modulus in the transverse direction of 550 Kg/mm.sup.2 or more a surface roughness Ra in the range of 0.015 to 0.040 .mu.m, and a thermal shrinkage rate in the longitudinal direction of 0.3% or less in a case where it was held at a temperature of 100.degree. C. for 1 hour. A magnetic tape for audio cassettes is provided which is capable of long-time recording and wherein deterioration of magnetic characteristics does not easily occur in use, storage and the like at a high temperature, for example in the open during summer or in cars, compared to conventional ones.