PURPOSE: To provide pulverizing and dispersing media which prevent the incorporation of an impurity into ITO starting material in pulverizing, mixing and dispersing stages and to produce high purity ITO starting material.
CONSTITUTION: First of all, 100g of powder which is compounded in 90:10wt. ratio with In2O3 powder and SnO2 powder having 4N purity is charged into a nylon pot of 3l volume. Then, the ball-like pulverizing and dispersing media having 10mm diameter and consisting of the ITO sintered compact having 92% relative density is charged into the pot so as to make 1l volume, and 200g pure water is added, and then the pot is placed on a ball mill pedestal and allowed to rotate for mixing at 70rpm for 10hr, and slurry is obtained. Then, the obtained slurry is dried, and the ITO starting material is obtained. Next, the ITO starting material is formed to prescribed shape and sintered, and a film is formed using this sintered compact by sputtering method and the ITO film having high purity and lower resistance is obtained.
TOISHI MITSUTERU
KUDO YOSHINORI
DOWA CHEMICAL KK