| 摘要 |
PURPOSE:To increase a polishing speed and to improve surface coarseness, by a method wherein specified acid is contained in alumina quality polishing material powder. CONSTITUTION:After sulfamin acid nickel is dissolved in slurry containing alumina quality polishing material powder, e.g. alpha-Al2O3, having an average grain size of 0.5-10mum, the solution is regulated to pH4-7 by means of sulfamin acid to prepare a composition for polishing an aluminum magnetic disc. In this case, a ratio of sulfamin acid nickel by which the composition is occupied is set to 0.5-10wt.%, and an occupying ratio of alumina quality material powder is set to 1-25wt.%. The action of the sulfamin acid nickel enables improvement of polishing performance of the composition, increase of a polishing speed, and improvement of surface coarseness. |
