| 摘要 |
PROBLEM TO BE SOLVED: To obtain a filler for a high temperature, having a low gas permeability by mixing a large-sized zirconia powder, a medium-sized zirconia powder each having a specified particle size and a zircon powder composed of fine particles having a specified particle diameter. SOLUTION: This filling material for a high temperature is obtained by preparing a large-sized zirconia powder having 10-40 μm particle diameter and a medium-sized zirconia powder having 1-10 μm particle diameter by crushing and classifying a raw powder of 3 mol.% yttria-stabilized zirconia, etc., having 10-80 μm particle diameter, 50 μm mean particle diameter and 10.9×10<-6> deg.C<-1> expansion coefficient, using fine particles of zircon having 0.1-1.0 μm particle diameter, 0.3 μm mean particle diameter, 10 m<2> /g specific surface area and 7.9×10<-6> deg.C<-1> expansion coefficient, forming a slurry of the fine particle zircon powder, a dispersing medium such as water and a dispersing agent such as a polycarboxylic acid ammonium, etc., by a dispersing treatment with a ball mill, etc., then adding the zirconia powder consisting of approximately 80 wt.% medium-sized particles and approximately 20 wt.% large-sized particles in a weight ratio of the zirconia powder/the zircon powder = (75/25)-(85/15) for dispersing. |
