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:
Feb. 14, 1995
Filed:
Sep. 20, 1993
Gisbert Schulze, Lauf, DE;
Hoechst CeramTec Aktiengesellschaft, Selb, DE;
Abstract
To prepare a ceramic molded article based on silicate or based on alumina, a ceramic starting material containing clay, kaolin, steatite and/or alumina is mixed with a silicate-containing flux, the mixture is made into a molded article and the molded article is heated and dense-sintered. At least some of the flux used is composed of a preferably alkali metal-free glass frit whose beginning of softening is above 850.degree. C. Advantageously, an alkali metal-free boron silicate glass is used in amounts of 0.1-20% by weight of the starting mixture. This process makes it possible to prepare, inter alia, ceramic molded articles comprising a glass phase and a crystalline portion substantially containing Al.sub.2 O.sub.3, in which the glass phase content is 22-34% by weight and comprises 50-68% by weight of SiO.sub.2, 12-22% of Al.sub.2 O.sub.3, 0.1-4.5% of Fe.sub.2 O.sub.3, 0.1-13% of TiO.sub.2, 0.1-23% of CaO, 0.1-9% of MgO, 0-7% of Na.sub.2 O, 0-11% of K.sub.2 O, 0-9% of BaO and 0-23% of B.sub.2 O.sub.3 and the crystalline portion comprises 1-25% of SiO.sub.2, 70-80% of Al.sub.2 O.sub.3, 0.1-1% of Fe.sub.2 O.sub.3, 0.1-3% of TiO.sub.2, 0.1-5% of CaO, 0.1-2% of MgO, 0-1.5% of Na.sub.2 O, 0-2.5% of K.sub.2 O, 0-2% of Bao and 0-5% of B.sub.2 O.sub.3.