| 摘要 |
Yellow iron oxide hydroxide particles suitable for use as a pigment comprise iron oxide hydroxide core particles provided with a composite oxide hydroxide of Fe and Al on the surface thereof, wherein: (i) the amount of Al in the composite oxide hydroxide is from 0.1 to 10 % by weight, calculated as Al, based on the weight of the iron oxide hydroxide core particle; (ii) the amount of Fe in the composite oxide hydroxide is 0.1 to 50 % by weight, calculated as Fe, based on the weight of the iron oxide hydroxide core particle; (iii) the ratio of Al to Fe in the composite oxide hydroxide is from 0.05:1 to 2:1, calculated as Al and Fe atoms; and (iv) said yellow iron oxide hydroxide particles have an average major axis diameter of from 0.1 to 1.0 mu m, an average minor axis diameter of from 0.02 to 0.10 mu m, an aspect ratio (major axis diameter/minor axis diameter) of from 2 to 20, a BET specific surface area of from 10 to 180 m<2>/g and a heat-resistance temperature of not less than 255 DEG C. |
