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:
Oct. 11, 1988
Filed:
Apr. 07, 1986
Keiichiro Koba, Tochigi, JP;
Akria Mathumoto, Tochigi, JP;
Yoshinori Koyanagi, Tochigi, JP;
Toshio Hamasaki, Tochigi, JP;
Katsuya Eguchi, Tochigi, JP;
Mitsui Mining Company, Limited, Tokyo, JP;
Abstract
Disclosed is a glass-ceramic product having a chemical composition, as expressed in terms of oxides with the exception of F, in the weight range of 35 to 60% SiO.sub.2, 10 to 20% Al.sub.2 O.sub.3, 12 to 25% MgO, 5 to 15% K.sub.2 O and 4 to 15% F, containing no B.sub.2 O.sub.3, and containing 40 to 70% by weight of fluorophlogopite microcrystals. This glass-ceramic product has a flexural strength of not less than 1500 kgf/cm.sup.2, a heat resistance of about 1100.degree. C., excellent dielectric properties and good machinability, and is a material capable of extending the range of use of high performance ceramics. The aforesaid glass-ceramic product can be made by dissolving, in a solvent consisting essentially of a polar solvent, compounds (consisting largely of alkoxide compounds) of the metallic components and a fluorine compound in such proportions as to give a final product having the aforesaid chemical composition, hydrolyzing these compounds, dehydrating and drying the resulting gel, and heat-treating the resulting dry solid.