| 摘要 |
PURPOSE:To eliminate defective molding and defective characteristics when granulated powder which is obtained by forming slurry from raw material powder whose main component is zinc oxide and by spraying and drying the slurry is bake and a voltage nonlinear resistor is fabricated by adding polycarboxylic acid ammoniate and zinc stearate into the slurry. CONSTITUTION:Praseodymium oxide, cobalt oxide, chromium oxide or the like of one atom% or less is added into the powder of zinc oxide. Pure water is added so that the solid-state component becomes 60weight%. Furthermore, 0.3weight% polycarboxylic acid ammoniate and 0.5weight% polyvinyl alcohol are added into the solid-state component. The materials are mixed in a ball mill for 20 hours. Thereafter, 1.2weight% zinc stearate is added and stirred. Agglomeration is not recognized in particles in the obtained slurry. The particles to the approximately primary particles are dispersed. The slurry is sprayed and dried with a spray dryer granulator. When the loading of the polycarboxylic acid ammoniate is 0.1-0.5weight%, the zinc stearate is added by 0.3-2.0weight%. Then, the viscosity of the slurry can be made low, and the dispersing state can be made uniform. Furthermore, the spherical granulated power can be obtained. |
