Title:
PROCESS FOR PRODUCING GLASS SUBSTRATE FOR INFORMATION-RECORDING MEDIUM
Document Type and Number:
WIPO Patent Application WO/2012/001924
Kind Code:
A1
Abstract:
A process for producing a glass substrate for information-recording media is provided in which when silica-based abrasive grains as an abrasive material are circulated and used for precisely polishing a glass plate having a composition containing cerium oxide, the number of times in which the abrasive material is circulable and usable is prevented from being limited. With the process, a glass substrate for information-recording media which has a satisfactory degree of flatness can be obtained. The process for producing a glass substrate for information-recording media includes: a rough polishing step in which a glass plate (10) is roughly polished using a polishing device (1) and a polishing liquid (7) containing an abrasive material comprising cerium oxide as a main component and then cleansed so that the amount of cerium oxide present on the glass plate surfaces falls to 0.125 ng/cm2 or below; and a subsequent precise polishing step in which the roughly polished glass plate is precisely polished using an abrasive material comprising colloidal silica.
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Inventors:
NAKAE, Hazuki (INC. 2970, Ishikawa-machi, Hachioji-sh, Tokyo 05, 〒1928505, JP)
Application Number:
JP2011/003604
Publication Date:
January 05, 2012
Filing Date:
June 23, 2011
Export Citation:
Assignee:
KONICA MINOLTA OPTO, INC. (2970, Ishikawa-machi Hachioji-sh, Tokyo 05, 〒1928505, JP)
コニカミノルタオプト株式会社 (〒05 東京都八王子市石川町２９７０番地 Tokyo, 〒1928505, JP)
コニカミノルタオプト株式会社 (〒05 東京都八王子市石川町２９７０番地 Tokyo, 〒1928505, JP)
International Classes:
C03C19/00; B24B37/00; C03C3/087; C03C3/095; G11B5/73; G11B5/84
Attorney, Agent or Firm:
KOTANI, Etsuji et al. (Osaka Nakanoshima Building 2nd Floor, 2-2 Nakanoshima 2-chome, Kita-ku, Osaka-sh, Osaka 05, 〒5300005, JP)
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Claims: