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:
Nov. 17, 1981
Filed:
Dec. 15, 1980
William B Crandall, Alfred Station, NY (US);
Alfred University Research Foundation, Alfred, NY (US);
Abstract
A ceramic product having an expansion coefficient from about 1.0.times.10.sup.-6 .degree.C. to about 2.5.times.10.sup.-6 .degree.C. containing a sintered mixture of spodumene and clay is described. The sintered mixture also includes iron oxide in an amount from about 1.0% to about 7.0% by weight of the total sintered mixture. The final product includes a .beta. spodumene solid solution and mullite, and has a mullite content of less than 10% by volume. The presence of iron oxide in the sintered mixture reduces the formation of mullite during the formation of .beta. spodumene and thus reduces the expansion coefficient of the final product. The process for preparing the ceramic products described herein includes providing an intimate mixture of 40% by weight to 60% by weight of spodumene and 40% by weight to 60% by weight of clay and heating the mixture in the presence of iron oxide at a suitable time and temperature, within a range from cone 5 to cone 10 and preferably within a range from cone 6 to cone 9. The ceramic body is coated with a suitable glaze which preferably contains from about 70% by weight to about 90% by weight of spodumene and from about 10% by weight to about 30% by weight of talc and 20% by weight to about 10% by weight of whiting. The glaze composition also includes from about 1.0% by weight to about 7.0% by weight of iron oxide. The base portion of the ceramic products of this invention is optionally coated with a suitable terra sigillata for aesthetic purposes and also to avoid sticking of the product to the furnace during the firing process. The terra sigillata composition typically contains from about 10% by weight to 35% by weight of spodumene, 65% to 90% by weight of clay and 1% by weight to 7% by weight of iron oxide. Because of their low expansion coefficients the products of the invention are useful for a multitude of household purposes. They can readily withstand the thermal shock encountered when exposed to the extreme heating or cooling conditions normally present in household environments.