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:
Oct. 13, 1987
Filed:
Aug. 21, 1985
Seishiro Nakamura, Kurashiki, JP;
Katsutoshi Oukami, Kurashiki, JP;
Kuraray Co., Ltd., Kurashiki, JP;
Abstract
An improved process for producing shaped ceramic articles of calcium phosphate by reacting calcium ions with phosphate ions in an aqueous medium at pH 8 or up to give gelatinous precipitates of calcium phosphate, with the molar ratio of calcium to phosphorus being 1.45 to 1.75, dispersing the precipitates into an aqueous medium to give a slurry containing 5 to 25 wt % of solids, casting the slurry into a mold conforming to the desired shape of the article and having the mold face finished sooth with a hydrophobic polymer or metal, drying the slurry at 130.degree. C. or below to give a ceramic green body of calcium phosphate, and sintering the green body at 800.degree. to 1400.degree. C., wherein said improvement comprises casting the slurry into a centrifuge tube which functions as a mold, centrifugally separating the slurry into a supernatant layer and a precipitate layer containing less than 73 wt % of water with a centrifugal force greater than 1100 G, removing the supernatant liquid from the centrifuge tube, and drying the precipitate layer in the centrifuge tube. The green body of calcium phosphate is sintered to give a ceramic article of desired shape with no cracking.