| abstract |
Provided are surface-treated calcium carbonate fillers useful for curable resins and imparting properties excellent in heat resistance, discoloration resistance, strength, and elongation, and curable resin compositions containing the fillers. A surface-treated calcium carbonate filler for a curable resin composition, which is a surface-treated calcium carbonate obtained by treating a calcium carbonate synthesized using a dense limestone with a surface-treating agent, characterized in that it satisfies the following formulas (1) to ( 4), (1) 0≤Mg≤2000, (2) 0≤Fe≤200, (3) 70≤SFa≤100, (4) 0≤UFa≤30 Mg: The ratio of magnesium contained in the surface-treated calcium carbonate [ppm] Fe: Ratio of iron contained in surface-treated calcium carbonate [ppm] SFa: Ratio of saturated fatty acid in surface treatment agent containing monovalent water-soluble salt of fatty acid [% by weight] UFa: Monovalent water-soluble containing fatty acid The ratio [wt%] of unsaturated fatty acid in the surface treatment agent of the sexual salt. |