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:
Dec. 08, 1998
Filed:
Jul. 26, 1996
Sumitomo Electric Industries, Ltd., Osaka, JP;
Abstract
A silicon nitride ceramic porous body having excellent acid and alkali resistance, mechanical strength, and durability can be employed as a filter or a catalytic carrier. The silicon nitride porous body contains a plurality of silicon nitride crystal grains with pores formed in grain boundary parts thereof, or includes a body part and a pore part wherein the body part is formed by a plurality of silicon nitride crystal grains and the pore part forms a three-dimensional network structure. The body part is formed by at least 90 vol. % of silicon nitride crystal grains, which are directly bonded to each other. In order to prepare the finished ceramic porous body, a porous body compact which is mainly composed of silicon nitride, is brought into contact with an acid and/or an alkali so that a component other than silicon nitride is partially or entirely dissolved and removed from the compact. The compact is prepared from a mixed powder of silicon nitride powder and at least one of a rare earth compound powder, a transition metal compound powder, and a bismuth compound, which is heat treated in the temperature range from 1600.degree. C. to 2100.degree. C.