US Patent 7510607 Coating composition and method for producing the same

A coating composition, a method for producing the coating composition, a coating film and magnetic recording medium are described. The coating composition comprises a binder, a solvent, and an α-alumina powder, wherein the α-alumina powder satisfies the following (a) and (b):(a) when the α-alumina powder is pressed to obtain a green body and the green body is sintered at 1250° C. under the atmospheric pressure, a relative density of the obtained sintered body is about 80% or more, and(b) a BET specific surface area of the α-alumina powder is about 10 m2/g or more.