Invention Grant
- Patent Title: Glass substrate for magnetic disk and method for producing the same
- Patent Title (中): 磁盘用玻璃基板及其制造方法
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Application No.: US12628484Application Date: 2009-12-01
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Publication No.: US08092280B2Publication Date: 2012-01-10
- Inventor: Mizuho Ishida , Norihito Shida , Katsuhiro Matsumoto , Kazuo Mannami
- Applicant: Mizuho Ishida , Norihito Shida , Katsuhiro Matsumoto , Kazuo Mannami
- Applicant Address: JP Tokyo
- Assignee: Asahi Glass Company, Limited
- Current Assignee: Asahi Glass Company, Limited
- Current Assignee Address: JP Tokyo
- Agency: Oblon, Spivak, McClelland, Maier & Neustadt, L.L.P.
- Priority: JP2008-307633 20081202
- Main IPC: B24B7/19
- IPC: B24B7/19 ; C03B17/00 ; G11B5/65

Abstract:
The present invention relates to a method for producing a glass substrate for a magnetic disk, the method including a step of polishing a main surface of a circular glass plate while supplying a polishing slurry containing a polishing material, in which polishing is performed, after a polishing surface is subjected to dressing treatment, by using a polishing pad having: a first resin foam layer which forms the polishing surface, includes a resin foam having pores with a pore diameter of more than 20 μm and has a thickness of 400 μm or less; and a second resin foam layer which is provided between a platen for fixing the polishing pad and the first resin foam layer, includes a resin foam having pores with a pore diameter of 20 μm or less and has a thickness of 50 to 250 μm, and in which a total thickness of the first resin foam layer and the second resin foam layer is 550 μm or less, and a international rubber hardness degree of the polishing pad measured by the M method according to JIS K6253 is 40 IRHD or more.
Public/Granted literature
- US20100136372A1 GLASS SUBSTRATE FOR MAGNETIC DISK AND METHOD FOR PRODUCING THE SAME Public/Granted day:2010-06-03
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