International Business Machines Corporation

Rainer Morbitzer

Johannes Windeln

Heinz Hilgers

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.

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Mainz-Kostheim, Germany

Rainer Morbitzer