摘要 |
<p>Alunite type compound particles represented by the following general formula (I) and having a specific value of D 75 /D 25 when D 25 is the particle diameter of particles which account for 25 % of the total and D 75 is the particle diameter of particles which account for 75 % of the total in the cumulative particle size distribution curve measured by a laser diffraction method:
€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒ€ƒM a [Al 1-x M' x ] 3 (SO 4 2- ) y (OH) z ·mH 2 O€ƒ€ƒ€ƒ€ƒ€ƒ(I)
wherein M is at least one cation selected from the group consisting of Na + , K + , NH 4 + and H 3 O + , M' is at least one cation selected from the group consisting of Cu 2+ , Zn 2+ , Ni 2+ , Sn 4+ , Zr 4+ and Ti 4+ , and a, m, x, y and z satisfy 0.8 ‰¦ a ‰¦ 1.35, 0 ‰¦ m ‰¦ 5, 0 ‰¦ x ‰¦ 0.4, 1.7 ‰¦ y ‰¦ 2.5, and 4 ‰¦ z ‰¦ 7, respectively. The above particles of the present invention have a small average particle diameter, are spherical, disk-like or hexagonal and have an extremely narrow particle size distribution.</p> |