Patent ID: 6752677
Filing Date: 2004-06-22
Classification: C03C,H01T

Abstract:
A method for producing a spark plug, the spark plug comprising a center electrode, a metal shell and an alumina ceramic insulator disposed between the center electrode and the metal shell, wherein at least part of the surface of the insulator is covered with a glaze layer comprising oxides,the method comprising the steps of: preparing a coated glaze powder so that a surface of each particle of a glaze powder is covered by an elution-suppressing coating layer, the elution-suppressing coating layer suppressing an elution of water soluble component that is contained in each particle of the glaze powder; preparing a glaze slurry by suspending the glaze powder in a water solvent; applying the glaze slurry to a surface of the insulator so as to form a glaze powder-deposited layer; and baking the glaze powder-deposited layer to the surface of the insulator to form the glaze layer by heating the glaze powder-deposited layer.