Patent ID: 6627566
Filing Date: 2003-09-30
Classification: C03C,G11B

Abstract:
A substrate for information recording medium composed of crystallized glass comprisingSiO2: 35-65 mol %, Al2O3: 5-20 mol %, MgO: 10-40 mol %, TiO2: 5-15 mol %, and K2O: 0.1-2 mol % wherein the sum of SiO2, Al2O3, MgO, and TiO2 is equal to or more than 93 mol %, and main crystals contained in the crystallized glass are enstatite and/or its solid solution;and wherein the crystallized glass has a molar ratio of Al2O3 to MgO (Al2O3/MgO) of less than 0.5, substantially does not comprise spinel as a crystal phase, and does not comprise ZnO.