Invention Application
- Patent Title: GLASS FOR MAGNETIC RECORDING MEDIUM SUBSTRATE AND USAGE THEREOF
-
Application No.: US14341142Application Date: 2014-07-25
-
Publication No.: US20140334276A1Publication Date: 2014-11-13
- Inventor: Naomi MATSUMOTO , Kazuaki Hashimoto
- Applicant: Hoya Corporation
- Applicant Address: JP Tokyo
- Assignee: HOYA CORPORATION
- Current Assignee: HOYA CORPORATION
- Current Assignee Address: JP Tokyo
- Main IPC: G11B5/73
- IPC: G11B5/73 ; C03C3/087 ; C03C3/085

Abstract:
An aspect of the present invention relates to glass for a magnetic recording medium substrate, which includes essential components in the form of SiO2, Li2O, Na2O, and one or more alkaline earth metal oxides selected from the group consisting of MgO, CaO, SrO, and BaO, wherein a molar ratio of a content of MgO to a combined content of MgO, CaO, SrO, and BaO (MgO/(MgO+CaO+SrO+BaO)) is equal to or greater than 0.80, and which has a Young's modulus of equal to or greater than 80 GPa, and a glass transition temperature of equal to or greater than 620° C.
Public/Granted literature
- US09007878B2 Glass for magnetic recording medium substrate and usage thereof Public/Granted day:2015-04-14
Information query
IPC分类: