Fine zirconium oxide powder and method for producing same
View Patent ↗There are provided a method for producing a fine zirconium oxide powder which has a narrower particle size distribution than that of conventional zirconium oxide powders and which is capable of lowering the starting temperature in the sintering reaction of a reactant to which the fine zirconium oxide powder is added. When a hydrated zirconium is calcined to be dispersed in a solvent with a dispersing agent, an alcohol (e.g., IPA or t-butanol) having a branched chain structure, not a straight chain structure, is used as the solvent, and a dicarboxylic acid (e.g., maleic acid or oxalic acid) having two carboxyl groups in its molecule is used as the dispersing agent. Thus, a fine zirconium oxide powder having a narrow particle size distribution and a small particle size at 90 vol % is obtained.
1. A method for producing a fine zirconium oxide powder comprising the steps of:
preparing a hydrated zirconium from an aqueous zirconium solution;
calcining the hydrated zirconium to form a calcined powder;
adding a solvent and a dispersing agent to the calcined powder to disperse the calcined powder in the solvent; and
drying and grinding the calcined powder dispersed in the solvent, to produce a fine zirconium oxide powder,
wherein said solvent is an alcohol having a branched chain structure, and said dispersing agent is a carboxylic acid having at least two carboxyl groups in its molecule.
2. A method for producing a fine zirconium oxide powder as set forth in claim 1 , wherein the amount of said carboxylic acid is no greater than 5 wt %.
3. A method for producing a fine zirconium oxide powder as set forth in claim 1 , wherein said fine zirconium oxide powder has a mean particle size of no greater than 0.2 μm, and a particle size at 90 vol % of no greater than 0.3 μm.
4. A method for producing a fine zirconium oxide powder as set forth in claim 1 , wherein said fine zirconium oxide powder has a bulk density of 0.3 to 0.6 g/cm 3 .
5. A method for producing a fine zirconium oxide powder as set forth in claim 1 , wherein said alcohol is 2-propanol or t-butanol.
6. A method for producing a fine zirconium oxide powder as set forth in claim 1 , wherein said carboxylic acid is a dicarboxylic acid.
7. A method for producing a fine zirconium oxide powder as set forth in claim 6 , wherein said dicarboxylic acid is maleic acid or oxalic acid.