Invention Application
- Patent Title: GLASS FOR INFORMATION RECORDING MEDIA SUBSTRATE, GLASS SUBSTRATE FOR MAGNETIC DISK AND MAGNETIC DISK
- Patent Title (中): 信息记录介质基板玻璃,磁盘和磁盘的玻璃基板
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Application No.: US12256172Application Date: 2008-10-22
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Publication No.: US20090110963A1Publication Date: 2009-04-30
- Inventor: Tetsuya NAKASHIMA , Kei Maeda , Noriaki Shimodaira , Atsuyoshi Takenaka
- Applicant: Tetsuya NAKASHIMA , Kei Maeda , Noriaki Shimodaira , Atsuyoshi Takenaka
- Applicant Address: JP Chiyoda-ku
- Assignee: ASAHI GLASS COMPANY, LIMITED
- Current Assignee: ASAHI GLASS COMPANY, LIMITED
- Current Assignee Address: JP Chiyoda-ku
- Priority: JP2007-279257 20071026; JP2008-112710 20080423
- Main IPC: G11B5/73
- IPC: G11B5/73 ; C03C3/093 ; C03C3/091 ; C03C3/085 ; C03C3/087

Abstract:
To provide a glass for an information recording media substrate, which is excellent in weather resistance.A glass for an information recording media substrate, which comprises, as represented by mol % based on oxide, from 61 to 66% of SiO2, from 11.5 to 17% of Al2O3, from 8 to 16% of Li2O, from 2 to 8% of Na2O, from 2.5 to 8% of K2O, from 0 to 6% of MgO, from 0 to 4% of TiO2 and from 0 to 3% of ZrO2, provided that Al2O3+MgO+TiO2 is at least 12%, and Li2O+Na2O+K2O is from 16 to 23%, wherein in a case of where B2O3 is contained, its content is less than 1%. The above glass for an information recording media substrate, wherein when the glass is left under steam atmosphere at 120° C. at 0.2 MPa for 20 hours, and the amount of Li, the amount of Na and the amount of K, which precipitate on a surface of the glass are represented as CLi, CNa and CK respectively, CNa is at most 0.7 nmol/cm2, and CLi+CNa+CK is at most 3.5 nmol/cm2.
Public/Granted literature
- US07838136B2 Glass for information recording media substrate, glass substrate for magnetic disk and magnetic disk Public/Granted day:2010-11-23
Information query
IPC分类: