Patent ID: 8741995

Claim:
A calcium carbonate surface-treated with a surface-treating agent containing a sodium salt and/or a potassium salt of a fatty acid, the surface-treating agent containing a sodium salt or a potassium salt of palmitic saturated acid in an amount of PW (% of total fatty acid content by weight), the surface-treating agent containing a sodium salt or a potassium salt of saturated stearic acid in an amount of SW (% of total fatty acid content by weight), a total amount of PW and SW being PW+SW≧90, a ratio of PW to SW being 0.30≦PW/SW≦1.1, a sodium salt or a potassium salt of a saturated fatty acid except palmitic acid and stearic acid, among the fatty acids, being a saturated fatty acid having 12, 14, and 20 to 31 carbon atoms, a sodium salt or a potassium salt of lauric acid and a sodium salt or a potassium salt of myristic acid being included in a total amount of 5% of total fatty acid content by weight or less, a sodium salt or a potassium salt of an unsaturated fatty acid being included in an amount of 5% of total fatty acid content by weight or less, the surface-treated calcium carbonate having a BET specific surface area of SA 2 (m 2 /g), the sodium salt or the potassium salt of the fatty acid being used for the treatment in an amount of FA (parts by weight) based on 100 parts by weight of calcium carbonate in terms of acid, the BET specific surface area (SA 2 ) being 15≦SA 2 ≦48, and a ratio (FA/SA 2 ) of the treatment amount (FA) to the BET specific surface area (SA 2 ) being 0.095≦FA/SA 2 ≦0.135, wherein the surface-treated calcium carbonate is extracted with diethyl ether to afford a treating agent extraction amount of 0.1% by weight.