PRODUCTION METHOD OF COLORED CALCIUM CARBONATE AND COLORED CALCIUM CARBONATE

To provide a colored calcium carbonate with reduced color saturation resulting from washing with water.SOLUTION: A method of producing colored calcium carbonate which is characterized in that, upon synthesizing calcium carbonate by blowing carbon dioxide gas into a calcium hydroxide suspension for a reaction, a dye is added prior to the completion of crystal growth of calcium carbonate particles so as to yield colored calcium carbonate comprising the dye incorporated in its crystal structure. Depending on the conditions of the reaction, particle sizes and specific surface areas of the synthesized calcium carbonate particles can be controlled. Colored calcium carbonate can be efficiently produced by adjusting the timing of addition of the dye and reaction temperature accordingly.SELECTED DRAWING: Figure 2 【課題】水洗浄による彩度の低下が抑えられた着色炭酸カルシウムの提供。【解決手段】水酸化カルシウム懸濁液に炭酸ガスを吹き込み、反応させることにより炭酸カルシウムを合成する際に、炭酸カルシウム粒子の結晶成長が完了するまでに色素を添加し、結晶構造内に色素が取り込まれた着色炭酸カルシウムを合成する。反応条件によって、合成される炭酸カルシウム粒子の粒子径や比表面積を制御することができ、それに応じて、色素の添加タイミングや反応温度を適切にすることにより、効率よく着色炭酸カルシウムを製造できる。【選択図】図２