The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Sep. 30, 2003
Filed:
Jul. 26, 2000
Xuelu Zou, Akishima, JP;
Katsuaki Uchida, Tokyo, JP;
Hoya Corporation, Tokyo, JP;
Abstract
Crystallized glasses for data recording media such as magnetic disks are provided, comprising 42-65 mol % SiO , 11-25 mol % Al O , 15-33 mol % MgO and 5.5-13 mol % TiO or 58-80 mol % SiO +Al O with MgO/(SiO +Al O ) being in the range of 0.125-0.55, wherein major crystals or crystals present at 50% by volume or more comprise &agr;-quartz solid solution or quartz-based crystals and enstatite and/or enstatite solid solution, or quartz-based crystals having a diffraction pattern almost comparable to that unique to quartz in the X-ray diffraction pattern and enstatite and/or enstatite solid solution and wherein the specific gravity is 2.9 g/cm or more. Said glass substrates have high Young's modulus, strength and heat resistance and excellent surface smoothness and surface homogeneity, and can be easily prepared.