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. 13, 2001
Filed:
May. 28, 1999
Masato Sekino, Tsukuba, JP;
Hiroyuki Nakagawa, Shimotsuma, JP;
Osamu Iwamoto, Tsukuba, JP;
Masaaki Ushioda, Shimodate, JP;
Tokuyama Corporation, Yamaguchi-ken, JP;
Abstract
Provided is a porcelain which is suitable as a dental porcelain capable of being fired on a ceramics core and has a low firing temperature and a low thermal expansion coefficient and which is excellent in a chemical durability. The above dental porcelain comprises glass containing silicon oxide, aluminum oxide, boron oxide, zinc oxide, sodium oxide and lithium oxide as principal components. The contents of these respective components in the above glass are 57 to 65% by weight of SiO,, 8 to 18% by weight of Al,O,, 15 to 25% by weight of B,O,, 0.1 to 2% by weight of ZnO, 3 to 7% by weight of Na,O and 2 to 8% by weight of Li,O respectively in terms of a percent by weight based on the total of the respective components when the respective components are reduced to SiO,, Al,O,, B,O,, ZnO, Na,O and Li,O respectively. The particularly preferred dental porcelain comprises glass having a thermal expansion coefficient of 6.0×10,(1/°C.) or less as a principal structural component.