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:
Jul. 10, 1990
Filed:
Dec. 26, 1989
International Business Machines Corporation, Armonk, NY (US);
Abstract
The invention concerns a method of increasing the lubricant retention of a magnetic layer, wherein a magnetic layer, containing magnetic particles dispersed in a curable organic binder system and organic solvents and an additive, is cured in a two-step process, wherein the magnetic layer, in a first step, is heated in an inert gas for a given time to a given temperature and, in a second step, in an inert gas to which oxygen has been added, for a given time to a given temperature. According to a preferred embodiment of the invention, the magnetic layer with polyvinyl methyl ether (PVME) as an additive is heated in nitrogen for 2.5 hours to 234.degree. C. and, after cooling down, in a nitrogen atmosphere containing 30 vol % oxygen for 60 minutes to 234.degree. C. In the first step, this kind of curing leads to polymerization of the binder and phase separation of PVME and in the second step of oxidation of PVME, forming a plurality of pores in the magnetic layer.