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. 28, 2004
Filed:
Jul. 03, 2002
Takeshi Hoshikawa, Kami-gun, JP;
Masatoshi Yamazoe, Kami-gun, JP;
Hirohisa Yamamoto, Osaka, JP;
Teruo Anraku, Osaka, JP;
Yamamoto Precious Metal Co., Ltd., Osaka, JP;
Abstract
The present invention provides a method for preparing a glass-ceramic containing leucite crystals, comprising the steps of: mixing (1) a glassy material comprising 53 to 65 wt. % of SiO , 13 to 23 wt. % of Al O , 9 to 20 wt. % of K O and 6 to 12 wt. % of Na O and (2) synthetic leucite seed crystals comprising 53 to 64 wt. % of SiO , 19 to 27 wt. % of Al O and 17 to 25 wt. % of K O, and heat-treating the mixture at 750 to 950° C. for 1 to 5 hours; and a dental porcelain powder and a metal-ceramic restoration both comprising a glass-ceramic prepared by the method. The porcelain comprising the glass-ceramic prepared by the method is substantially free of opacification and decrease in the coefficient of thermal expansion, during fusion-bonding to a metal frame.