| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a hard disc abrasive made of glass enabling a high quality abraded face to obtain in a high speed abrading properties, improved productivity and cost reduction to bring by comprising ceric oxide particle as a stable slurry dispersed in water, a ratio of the cerium to the whole rare earth elements being at least a certain value and the ceric oxide particle having a specific average secondary particle diameter. SOLUTION: A hard disc abrasive made of glass comprises a stable slurry of a cerie oxide particle having an average secondary particle diameter of 0.1-0.5 &mu m dispersed in water and contains 0.2-30 wt.% as a CeO2 concentration. A ratio of the cerium to the whole rare earth elements is preferably at least 95% in terms of weight of the oxide. The ceric oxide particle to be used comprises reacting a cerous salt with an alkali in a mole ratio of (OH)/(Ce3+)=3-30 in an aqueous medium under an inert gas atmosphere to prepare a suspension of cerous hydroxide, and then blowing a gas containing oxygen at a temperature of 10-90 deg.C in the atmosphere to produce the crystalline ceric oxide having the average secondary particle diameter of 0.1-0.5 &mu m.</p> |
