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. 23, 1993
Filed:
Jul. 27, 1992
Degussa Akteingesellschaft, , DE;
Abstract
Crystalline zirconium oxide powder with a BET surface of less than 30 m.sup.2 /g, preferably 10 to 20 m.sup.2 /g, a primary particle size of 0.1 to 0.5 .mu.m, a monoclinic crystal structure and, optionally, a content of Y.sub.2 O.sub.3 of 1 to 10% by weight and/or of 1 to 10% by wt. MgO. It is produced by adding an aqueous zirconium salt solution optionally containing yttrium ions and/or magnesium ions under agitation into a vessel which contains an aqueous base solution such as e.g. sodium hydroxide solution with a content of NaOH which corresponds to an excess of at least 0.5 mole/l NaOH. The mixture obtained in this manner is then treated hydrothermally at a temperature of 200.degree. to 400.degree. C., the product obtained is separated by filtration, washed chloride-free with water and dried at 100.degree. to 120.degree. C. The zirconium oxide powder can be used to produce sintered ceramics.