- Patent Title: Glass for magnetic recording medium substrate or for glass spacer to be used in magnetic recording/reproducing device, magnetic recording medium substrate, magnetic recording medium, glass spacer to be used in magnetic recording/reproducing device, and magnetic recording/reproducing device
-
Application No.: US17784528Application Date: 2020-12-11
-
Publication No.: US11999652B2Publication Date: 2024-06-04
- Inventor: Koichi Sato , Kazuaki Hashimoto
- Applicant: HOYA CORPORATION
- Applicant Address: JP Tokyo
- Assignee: HOYA CORPORATION
- Current Assignee: HOYA CORPORATION
- Current Assignee Address: JP Tokyo
- Agency: Global IP Counselors, LLP
- Priority: JP 19225368 2019.12.13
- International Application: PCT/JP2020/046405 2020.12.11
- International Announcement: WO2021/117897A 2021.06.17
- Date entered country: 2022-06-10
- Main IPC: G11B5/73
- IPC: G11B5/73 ; C03C3/087 ; C03C3/095 ; G11B5/235 ; G11B5/72
Abstract:
Provided is a glass for a magnetic recording medium substrate or for a glass spacer for a magnetic recording/reproducing apparatus, in which the total content of Li2O, Na2O, K2O, B2O3, and ZnO (Li2O+Na2O+K2O+B2O3+ZnO) is in a range of 0 mol % or more and 3 mol % or less, the mole ratio of the total content of Al2O3 and MgO relative to the total content of SiO2 and CaO [(Al2O3+MgO)/(SiO2+CaO)] is in a range of 0.30 or more and 0.6 or less, the total content of SiO2 and Al2O3 (SiO2+Al2O3) is in a range of 64 mol % or more and 85 mol % or less, and the total content of SiO2, Al2O3, MgO, and CaO (SiO2+Al2O3+MgO+CaO) is in a range of 87 mol % or more and 98 mol % or less.
Public/Granted literature
Information query
IPC分类:
