| 摘要 |
PURPOSE:To obtain the title high-purity fine hydroxyapatite particles with reduced formation of a mixed phase and having excellent crystallinity by adding a specified amt. of an aq. soln. of H3PO4 to a slurry contg. a non-phosphoric acid type reactive Ca salt, and heating the mixture to cause a reaction. CONSTITUTION:An aq. soln. of H3PO4 is added to a slurry contg. a non- phosphoric acid type reactive Ca salt so that the atomic ratio of Ca/P is controlled to >=10/6, and the mixture is subjected to a reaction at >=50 deg.C. The pH of the product thus obtained is controlled by adding an org. acid or an inorg. acid. Hydrochloric acid, sulfuric acid, nitric acid, etc., are exemplified as the inorg. acid, and acetic acid, oxalic acid, tartaric acid, etc., are used as the org. acid. When those acids are added to control the pH, the atomic ratio of Ca/P of the obtained hydroxyapatite can be controlled to <=1.67. Ca(OH)2 is most preferably used from the standpoint of reactivity.
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