| 摘要 |
PURPOSE:To obtain the titled compound having high cleaning performance and low abrasive action, exhibiting excellent tooth-whitening effect and suitable as an abrasive base for dentifrice, by neutralizing phosphoric acid with a Ca compound such as quick lime or CaCO3 in the presence of a specific habit modifier. CONSTITUTION:One or more kinds of Ca compounds selected from quick time, slaked lime and CaCO3 are added to water at a concentration of e.g. 50-200g/l (in terms of CaO) and stirred to obtain milk of lime consisting of a slurry of fine Ca(OH)2, etc. The lime of milk is added to an aqueous solution of phosphoric acid heated at <=50 deg.C. Preferably after the initiation of the neutralization reaction, the reaction mixture is added with a condensed phosphoric acid (e.g. pyrophosphoric acid) or its salt of alkali metal, alkaline earth metal, Al, etc., as a habit modifier in an amount of 20-50pts.wt. (in terms of P2O7) based on 100pts.wt. of the resultant compound and the neutralization reaction is completed to obtain the titled compound having a density of 1.9-2.29g/cm<3>, a specific surface area of 10-50m<2>/g and an average particle diameter of 10-50mu and consisting of aggregates of primary particles having a particle diameter of 0.01-0.9mu. |
