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. 18, 1989
Filed:
May. 02, 1988
Jay W Palmer, Tampa, FL (US);
Terry L Rosenstiel, Mount Prospect, IL (US);
United States Gypsum Company, Chicago, IL (US);
Abstract
This invention relates to the manufacture of hydroxylapatite in a through-solution process wherein monobasic calcium phosphate is reacted with a calcium hydroxide solution. In a preferred embodiment, an acidic premix is formed by reacting phosphoric acid and calcium hydroxide with high shear agitation in a first stage, and thereafter reacting the acidic premix with a saturated solution of calcium hydroxide also under high shear agitation in a second stage. The second stage reaction is carried out in an alkaline solution by carefully metering the acid premix into the calcium hydroxide solution whereby the pH of the solution is maintained above 11 until the reaction is near completion. It is particularly preferred to use a stoichiometric portion of calcium hydroxide in carrying out the reactions. After the hydroxylapatite precipitate is recovered, it may be sintered at a temperature between about 700.degree. C. and 1100.degree. C. for about 5 to 30 minutes to form a crystalline hydroxylapatite.