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:
Apr. 11, 1989
Filed:
Dec. 22, 1987
Yoshio Mohri, Matsusaka, JP;
Kinji Sano, Matsusaka, JP;
Central Glass Company, Limited, Ube, JP;
Abstract
A transparent, semitransparent or opaline glass-ceramics containing calcium phosphate crystals uniform and very fine in grain size is obtained by heat-treating a glass essentially comosed of 38-52 wt % of SiO.sub.2, 4-16 wt % of P.sub.2 O.sub.5, 6-18 wt % of Al.sub.2 O.sub.3 (may partly be replaced by La.sub.2 O.sub.3), 20-33 wt % of CaO (may partly be replaced by MgO, BaO,SrO and/or ZnO), 4-17 wt % of ZrO.sub.2 (may partly be replaced by TiO.sub.2) and 0-0.5 wt % of alkali metal oxide(s), wherein the molar ratio of P hd 2O.sub.5 to ZrO.sub.2 is not greater than 3:1, at a temperature above the transition temperature and below the softening temperature of the glass. This glass-ceramics is excellent in refractoriness, electrical insulation resistance, chemical resistance and mechanical strength and has a relatively high coefficient of thermal expansion.