Patent ID: 6569519
Filing Date: 2003-05-27
Classification: C01F,C01P,C08K,Y10T

Abstract:
An &agr;-alumina powder, comprising &agr;-alumina particles having an average diameter of not less than about 2 &mgr;m and not more than about 5 &mgr;m, a particle size distribution such that a ratio of 90 wt % diameter D90 to 10 wt % diameter D10 represented by D90/D10 is not more than about 2, and a crystalline form represented by an index A of more than about 0.40 and not more than about 0.50, wherein the index A is obtained by substituting X-ray intensities I(110), I(300) and I(116) at the (110) plane, the (300) plane and the (116) plane, respectively, determined by X-ray diffraction, into the following formula (I):A={I(110)+I(300)}/{2Ã—I(116)}â€ƒâ€ƒ(I).