Process for the preparation of hydroxyapatite
AssigneeBK Ladenburg GmbH Gesellschaft fur Chemische Erzeugnisses
InventorsAlexander Maurer, Gudrun Raab, Guenter Raab, Reinhold Schmitt, Detlev Schober, Richard Taenzler
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Abstract
A process for the preparation of a hydroxyapatite, which is suitable as a tooth-cleaning substance, by precipitation from aqueous phosphoric acid and calcium hydroxide solution, in which a calcium-doped phosphoric acid solution is fed to an intensive mixer with a suspension of calcium hydroxide/oxide in a molar ratio of Ca:P=1.667 corresponding to the hydroxyapatite of and reacted there at precipitation temperatures of 60.degree.-100.degree. C., preferably 80.degree.-90.degree. C. and a pH of 4-8, preferably of 6.5-7.5. Also disclosed in a tooth-cleaning substance containing the hydroxyapatite.
Claims16
A process for the preparation of a hydroxyapatite suitable as a tooth-cleaning substance, comprising the steps of
- simultaneously feeding an acidic calcium phosphate solution having a molar ratio of Ca:P of from about 0.2:1 to 1:1 and a calcium suspension to an intensive mixer in a substantially stoichiometric molar ratio of Ca:P to provide a reaction mixture;
- reacting the reaction mixture under intensive mixing at a temperature of from about 60.degree. to about 100.degree. C. and at a pH of from about 4 to 8 to obtain a hydroxyapatite suspension;
- and
- separating a hydroxyapatite product from the suspension.
Dependencies are inferred from the claim text.