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:
Mar. 11, 1997
Filed:
May. 30, 1995
Maki Hamaguchi, Kobe, JP;
Tetsuya Yamamoto, Kobe, JP;
Tetsuo Suzuki, Kobe, JP;
Hideki Yamamuro, Kobe, JP;
Hiroshi Chosokabe, Kobe, JP;
Kabushiki Kaisha Kobe Seiko Sho, Kobe, JP;
Abstract
A carbon substrate is prepared from a molded article of thermosetting resin by heat-treating in an inert atmosphere. The resin is characterized in that the content of Fe, Al, Ni, Co, Cr, and Mg insoluble in the resin is less than 1 ppm each and the content of Ca and Si insoluble in the resin is less than 2 ppm each. The thermosetting resin is further characterized in that the water content is less than 3 wt % and the ratio of the methylene carbon (CH.sub.2) connected to the hydroxyl group (OH) is less than 3% (based on the total carbon number). The carbon substrate prepared in this manner is almost free of defects and voids. It is suitable for use as the substrate of magnetic recording medium. The thermosetting resin may be a powdery or granular one which fluidizes and then cures on heating. A molded article of thermosetting resin is prepared by introducing the resin melt into a mold and curing it with heating under pressure. It is subsequently heat-treated in an inert atmosphere to give a molded article of glass-like carbon.