发明授权
- 专利标题： Glass substrate for information recording medium and magnetic information recording medium to which the glass substrate is applied
- 专利标题（中）： 用于信息记录介质的玻璃基板和应用玻璃基板的磁信息记录介质
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申请号： US10156659申请日： 2002-05-29
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公开(公告)号： US06818576B2公开(公告)日： 2004-11-16
- 发明人: Mikio Ikenishi , Atsuko Morita , Xuelu Zou
- 申请人： Mikio Ikenishi , Atsuko Morita , Xuelu Zou
- 优先权： JP2001-165226 20010531
- 主分类号： C04B3089
- IPC分类号： C04B3089
摘要：
Disclosed are a glass substrate for an information recording medium, having excellent scratch resistance and a light weight and having high fracture toughness, the glass substrate having a fragility index value, measured in water, of 12 &mgr;m−1/2 or less or having a fragility index value, measured in an atmosphere having a dew point of −5° C. or lower, of 7 &mgr;m−1/2 or less, or the glass substrate comprising, by mol %, 40 to 75% of SiO2, 2 to 45% of B2O3 and/or Al2O3 and 0 to 40% of R′2O in which R′ is at least one member selected from the group consisting of Li, Na and K), wherein the total content of SiO2, B2O3, Al2O3 and R′2O is at least 90 mol %, and a magnetic information recording medium comprising a magnetic recording layer formed on the glass substrate.