| 摘要 |
PROBLEM TO BE SOLVED: To provide a cerium oxide-based polishing agent substantially free of fluorine that can polish a glass substrate used for a hard disk substrate at high polishing speed, while achieving the reduction of surface roughness of glass substrate and the suppression of the occurrence of polishing flaws, and to provide a method for manufacturing a hard disk substrate made of glass. SOLUTION: There are provided a cerium oxide-based polishing agent for a hard disk substrate made of glass that satisfies the following requirements (1) to (5); and a method for manufacturing the hard disk substrate made of glass using the polishing agent. (1) The cerium oxide-based polishing agent has the total amount of rare earth oxides (TREO) of 95 mass% or more, and the amount of cerium oxide of 99 mass% or more based on the TREO. (2) The cerium oxide-based polishing agent contains fluorine of 0.05 mass% or less. (3) The cerium oxide has the crystallite diameter of 700 to 1000Åcalculated from powder X-ray diffraction. (4) The cerium oxide has the average particle diameter (D<SB POS="POST">50</SB>) of 0.4 to 0.8μm. and (5) The hard disk substrate made of glass has the Vickers hardness of 570 Hv or more. COPYRIGHT: (C)2012,JPO&INPIT |
