| 摘要 |
PROBLEM TO BE SOLVED: To produce a hydroxyapatite platelike large-sized crystal under comparatively mild reaction conditions and without requiring any special device by heating an aqueous suspension of powdery CaHPO4 .2H2 O having platelike crystal form and fine powder CaCO3 to a specified temp. and maintaining the suspension at this temp. SOLUTION: The objective crystal is produced by heating an aqueous suspension of powdery CaHPO4 .2H2 O having platelike crystal form and fine powder CaCO3 having a <=5μm average particle size to a temp. within the range of 40 to 70 deg.C and maintaining the suspension at this temp. to allow it to react. At this time, when this temp. is <40 deg.C, the reaction rate becomes slow and unreacted powdery CaHPO4 .2H2 O or CaCO3 remains in the reaction product even at the time of allowing the suspension to react for >=10hr. On the other hand, when this temp. is >70 deg.C, crystal disintegration due to the release of crystallization water from CaHPO4 .2H2 O occurs to incur the formation of hydroxyapatite crystallites. |
