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:
Jul. 09, 2013
Filed:
Nov. 13, 2009
Isao Yamashita, Kanagawa, JP;
Koji Tsukuma, Kanagawa, JP;
Isao Yamashita, Kanagawa, JP;
Koji Tsukuma, Kanagawa, JP;
Tosoh Corporation, Tokyo, JP;
Abstract
Because fracture toughness and translucency of translucent colored alumina sintered body of the past were low, the alumina sintered body was not suitable for uses such as dental materials, which require high toughness. The present invention relates to providing a translucent colored alumina sintered body that contains transition metal oxides, and with which the fracture toughness is 4.5 MPa·mor more and the maximum value of total forward transmittance (sample thickness 1 mm) to a wavelength of 300-800 nm is 60% or more. The present invention relates to obtaining a sintered body, at least 20% of which contains anisotropic grains with a long axis length of 10 μm or greater and an aspect ratio of 1.5 or more by subjecting an alumina sintered body containing transition metal oxides having a eutectic point with alumina or an alumina sintered body containing transitional metal oxides and at least one selected from the group consisting of Group 1A alkali metal oxides, Group 2A alkaline earth metal oxides, and SiO, BO, POand GeOto pressureless sintering and HIP treatment.