PURPOSE: To obtain calcium phosphate having good disperse stability in liquid by adding a hydrophilic emulsifier having HLB higher than a specified value to calcium phosphate subjected to wet crushing in water.
CONSTITUTION: Water is added to calcium phosphate having 2-100m2/g specific surface area X by a nitrogen absorption method to prepare 1-60wt.% water suspension. To 100 pts.wt. of calcium phosphate in water slurry prepared by wet crushing in a wet crusher into the water suspension so that the conditions, Y≤100X/27+88000/9, 2≤X≤100, and Y≥10, may be satisfied, where Y= A×B×C1.3×D×E/100×F1.6×(100-D), A is the packed quantity of media of the wet crusher, B is true specific gravity of the media, C is peripheral velocity of the disc or rotor of the wet crusher (m/sec), D is solid content concentration of calcium phosphate (wt.%), E is residence time in a crushing chamber (min), and F is a particle diameter of the media (mm), 5-100 pts.wt. of a hydrophilic emulsifier of ≥10 HLB 10 (e.g. cane sugar fatty acid ester of ≥15 HLB) is added.
HASHIMOTO KAYOKO
TAKAHASHI MASAKO
MOTOYOSHI SHIRO
