| 摘要 |
PROBLEM TO BE SOLVED: To obtain a polishing composition having a high polishing rate and permitting to obtain an excellent processed surface usable in a magnetic disc devices by mixing an abrasive such as aluminum oxide or silicon dioxide with a metal salt, a chelating agent and water. SOLUTION: 0.1-50 wt.%, desirably 1-25 wt.% at least one abrasive selected among aluminum oxide, zirconium oxide, titanium oxide, silicon nitride and manganese dioxide each of which has a mean particle diameter of 0.01-10 μm, silicon dioxide having a mean particle diameter of 0.005-0.5 μm and cerium oxide having a mean particle diameter of 0.01-10 μm, 0.01-40 wt.%, desirably 0.05-25 wt.% metal salt comprising an aluminum salt selected from aluminum nitrate, aluminum sulfate, aluminum chloride, sodium aluminum sulfate, etc., 0.001-40 wt.%, desirably 0.05-25 wt.% chelating agent and optionally an additive such as cellulose or a water-soluble alcohol are dispersed or dissolved in water to obtain a polishing composition having a pH of 7 or below. |
