Method of injection-molding zirconia ceramic.

摘要

A method of manufacturing sinters by hot-kneading zirconia ceramic powder and an organic binder, injection-molding the kneaded mixture, removing the organic binder from the moldings, then burning the binder-removed moldings, characterized by 0.5 to 15 moles of at least one oxide chosen from yttrium oxide, magnesium oxide, calcium oxide, or cerium oxide being added to said zirconia ceramic powder; The average particle size of said zirconia ceramic powder being equal to or smaller than 1 mu m; Said organic binder comprising one or more organic substances soluble to an alcohol or to a mixed solvent of an alcohol and a mixture of water, aliphatic ketone, and aromatic hydrocarbon, such as polyethylene glycol, glycol-fatty acid ester, glycerol-fatty acid ester, polyvinyl butyral, polyvinyl methyl ether, polyvinyl ethyl ether, and propionic acid vinyl, and one or more thermoplastic resins insoluble to an alcohol nor to the mixed solvent; and said organic binder being removed from moldings formed by injection-molding by putting the moldings in contact with the alcohol or the mixed solvent to extract the substances soluble to the alcohol or to the mixed solvent in said organic binder, then heating the moldings in an oxidizing gas to remove the remaining substances insoluble to the alcohol nor to the mixed solvent in the organic binder. By the improved organic binder and the improved removing method of the organic binder, the method of the present invention can injection-mold zirconia ceramic powder with average particle size 1 mu m which requires addition of 55% by volume or more resins and is difficult to injection-mold by conventional methods. This method makes it possible to manufacture zirconia ceramic products with a high density and a high mechanical strength.