| 摘要 |
PROBLEM TO BE SOLVED: To provideα-alumina powder for a magnetic recording medium, which can be easily dispersed in a binder resin. SOLUTION: Theα-alumina powder for the magnetic recording medium has a≥10 m<SP>2</SP>/g BET specific surface area and a sintered body obtained by calcining theα-alumina at 1,250°C under normal pressure has≥80% relative density. Theα-alumina powder is manufactured by calcining anα-alumina precursor which does not substantially contain metal elements other than aluminum under an atmosphere of≤600 Pa partial pressure of steam. Theα-alumina powder is dispersed in the binder resin to obtain a coating composition for the magnetic recording medium. The magnetic recording medium having a magnetic recording layer formed by applying the coating composition for the magnetic recording medium on a supporting substrate on the supporting substrate has a smooth surface. COPYRIGHT: (C)2005,JPO&NCIPI |
