公开(公告)号：US20180222789A1

公开(公告)日：2018-08-09

申请号：US15945144

申请日：2018-04-04

Applicant: ASAHI GLASS COMPANY, LIMITED

Inventor： Eriko MAEDA ,  Hiroyuki HIJIYA ,  Kensuke NAGAI ,  Tetsuya NAKASHIMA ,  Yutaka KUROIWA

IPC: C03C3/091 ,  C03C3/087 ,  C03C3/085 ,  C03C4/20

Abstract: The present invention pertains to a glass for a data storage medium substrate which contains a specific amount of each of SiO2, Al2O3, MgO, CaO, SrO, BaO, Li2O, Na2O, and K2O, in molar percentage based on the oxides, and does not substantially contain B2O3 or ZrO2, wherein the sum of the Li2O, Na2O, and K2O contents (R2O), the molar ratio of the SiO2 content to the Al2O3 content (SiO2/Al2O3), and the molar ratio of the sum of the SiO2 and Al2O3 contents (SiO2+Al2O3) to R2O [(SiO2+Al2O3)/R2O] fall within their specific ranges, formula (1): 90