PROBLEM TO BE SOLVED: To provide a method for producing a calcium phosphate composition excellent in X-ray radiopacity, whose cured object has high mechanical strength when being used in a clinical field or the like.SOLUTION: In this method for producing calcium phosphate composition, a calcium phosphate composition is produced, which comprises tetracalcium phosphate particles (A), calcium hydrogenphosphate particles (B) and X-ray contrast agent particles (C) with the blending ratio (A/B) between (A) and (B) of 40/60-60/40 in terms of the molar ratio, and which has following properties, after mixing and crushing (B) and (C) and then mixing (A) therewith, namely, the average particle size of (A) is 5-30 μm, the average particle size of (B) is 0.1-5 μm, the average particle size of (A) is larger than the average particle size of (B), the average particle size of (C) is ≤3 μm, and 1-50 pts.wt. (C) is contained with respect to a 100 pts.wt total of (A) and (B), wherein the mean value of X-ray impermeability of a cured object having a thickness of 1 mm obtained by curing the composition at the powder/liquid mixing weight ratio of 2.5 is 3-9 mm in terms of the thickness of an aluminum plate.COPYRIGHT: (C)2013,JPO&INPIT【課題】臨床現場で使用する際などに硬化物の機械的強度が高く、かつX線造影性の良好なリン酸カルシウム組成物の製造方法を提供する。【解決手段】リン酸四カルシウム粒子(A)、リン酸水素カルシウム粒子(B)及びX線造影剤粒子(C)からなり、(A)と(B)の配合割合(A/B)がモル比で40/60~60/40であり、(B)と(C)とを混合して粉砕してから(A)と混合することより、(A)の平均粒径が5~30μm、(B)の平均粒径が0.1~5μm、(B)の平均粒径に比べて(A)の平均粒径が大きく、(C)の平均粒径が3μm以下であり、かつ(A)及び(B)の合計100重量部に対し、1~50重量部の(C)を含むリン酸カルシウム組成物を製造し、前記組成物が、粉/液混合重量比2.5で硬化して得られる厚さ1mmの硬化物のX線不透過性の平均値がアルミ板の厚さで3~9mmであるリン酸カルシウム組成物の製造方法である。【選択図】なし
