PROBLEM TO BE SOLVED: To provide a calcium carbonate composite improved in an oil absorption per 1 g of phosphorus.SOLUTION: There is provided a calcium carbonate composite which comprises calcium carbonate and a reaction product of phosphorus and calcium, wherein the oil absorption with respect to the weight of the whole calcium carbonate composite is 100-200 ml/100 g and the oil absorption with respect to the weight of phosphorus is 15 ml/g or more. There is provided a method for producing a calcium carbonate composite, which is preferably carried out at 30°C or less and which comprises: a carbonation step ST1 of performing carbonation by applying carbon dioxide to an aqueous calcium hydroxide suspension and an addition step ST2 of adding phosphoric acid or a phosphate to the aqueous calcium hydroxide suspension in a predetermined addition period. There is provided a calcium carbonate composite in which the molar ratio (Ca/P) of calcium to phosphorus is 5 to less than 500 and the calcium carbonate has a crystallite size of 40 nm.SELECTED DRAWING: Figure 1COPYRIGHT: (C)2017,JPO&INPIT【課題】リン1gあたりの吸油量を向上させた炭酸カルシウム複合体の提供。【解決手段】炭酸カルシウムと、リンとカルシウムの反応物を含み、炭酸カルシウム複合体全体の重量に対する吸油量が、100~200ml/100gであり、リンの重量に対する吸油量が、15ml/g以上である炭酸カルシウム複合体。水酸化カルシウム水懸濁液に二酸化炭素を付与して炭酸化する炭酸化工程ST1と、所定の添加期間において水酸化カルシウム水懸濁液に、リン酸又はリン酸塩を添加する添加工程ST2と、好ましくは30℃以下で行うことと、を含む製造工程である炭酸カルシウム複合体製造方法。カルシウムとリンのモル比(Ca/P)が5~500未満であり炭酸カルシウムの結晶子サイズが40nmである炭酸カルシウム複合体。【選択図】図1
