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AssigneeHitachi, Ltd.
InventorsHeigo Ishihara, Akira Osaki, Takanori Kudo
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A magnetic recording medium is prepared by applying a magnetic paint containing at least magnetic particles and a thermally curable binder to a substrate, thermally curing the applied magnetic paint, thereby forming a magnetic film, and impregnating micropores formed in the magnetic film with a lubricant, where the magnetic paint further contains a poly(alkyleneoxide)-grafted binder, and the grafted poly(alkyleneoxide) moiety is thermally decomposed during the thermal curing, thereby forming the micropores in the magnetic film. A large number of micropores having a pore size of not more than 0.1 .mu.m are formed in the magnetic film, and a magnetic disk of high durability with less noises and errors during the recording and reproduction can be obtained.
A process for producing a magnetic recording medium which comprises applying a magnetic paint containing at least magnetic particles and a thermally curable binder to a substrate, thermally curing the applied magnetic paint, thereby forming a magnetic film, and impregnating micropores formed in the magnetic film with a lubricant, the magnetic paint further containing a poly(alkyleneoxide)-grafted binder, the grafted poly(alkyleneoxide) moiety being thermally decomposed during the thermal curing, thereby forming the micropores in the magnetic film.
A magnetic paint, which comprises at least magnetic particles and a thermally curable binder, a portion of the thermally curable binder being a poly(alkyleneoxide)-grafted thermally curable binder.
A process for producing a magnetic recording medium, which comprises applying a paint containing a thermally curable binder and a poly(alkyleneoxide)-grafted binder as a portion of the binder to a substrate, thereby forming an underlayer, subjecting the underlayer to primary curing at a temperature at which the poly(alkyleneoxide) can remain in the underlayer, then applying a magnetic paint containing at least magnetic particles and a thermally curable binder to the underlayer, thereby forming a magnetic film, subjecting the magnetic film and the underlayer to a secondary curing at a higher temperature than the temperature for the primary curing, thereby thermally decomposing the poly(alkyleneoxide) moiety in the underlayer and dissipating the decomposition products, thereby forming a large number of fine pores in the underlayer and forming micropores extending from the fine pores to the surface of the magnetic film at the same time, and impregnating fine pores with a lubricant from the micropores.
Dependencies are inferred from the claim text.