Method of producing magnetic coating material for magnetic recording media
AssigneeTDK Electronics Co., Ltd.
InventorsYukihiro Isobe, Masashi Hayama, Kenji Hirabayashi
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Abstract
A magnetic coating material for magnetic recording media is produced by dispersing a magnetic coating material containing from 0.1 to 2.0% of an abrasive and from 0.05 to 1.0% of a betaine type ampholytic antistatic agent, both on the basis of the amount of a magnetic powder, in a dispersion mill using steel balls. The abrasive has a hardness of not lower than 6 on Mohs' scale.
Claims3
A method of producing a magnetic coating material for magnetic recording media, which comprises the steps of charging a mixture of a magnetic powder and a binder composition containing from about 0.1 to about 2.0% of an abrasive and from about 0.05 to about 1.0% of a betaine type ampholytic antistatic agent, both on the basis of the amount of a magnetic powder, together with steel balls and dispersing said mixture;
- said abrasive having a hardness of not lower than 6 on Mohs' scale.
A method for producing a degradation-resistant magnetic coating material for recording media comprising the steps of charging into a steel ball mill containing steel balls, a magnetic powder, a binder composition containing about 0.1% to about 2.0% of an abrasive having a Mohs' hardness of not less than 6 based on the weight of said megnetic power, and about 0.05 to about 1.0% of a betaine type ampholytic antistatic agent based on the weight of said magnetic powder, and dispersing said mixture in said mill.
Dependencies are inferred from the claim text.