| 摘要 |
<p>PURPOSE:To obtain a giant particle directly from a varistor powder, to be a low cost and to be provided with an excellent characteristic by a method wherein zinc oxide is used as a main component, an auxiliary component in very small quantities is added to and mixed with it and this mixture is molded and baked in an active oxygen atmosphere. CONSTITUTION:For example, a raw material in which an auxiliary component such as praseodymium oxide (Pr6O11), lanthanum oxide (La2O3), boron oxide (B2O3) or the like in proper quantities has been added to zinc oxide (ZnO) powder is mixed sufficiently by using a wet ball mill; a granulated powder (a varistor raw-material powder) is obtained by using a spray drier; and it is baked for several hours. As a baking atmosphere, the concentration of air and nitrous oxide (N2O) is changed; and the powder is baked under their atmospheric pressure. When the varistor powder is baked in an active oxygen atmosphere, it is not required to manufacture nucleus particles. Atoms are diffused easily in the active oxygen atmosphere because particles are grown; and giant particles can be obtained at a low temperature and in a short time. The auxiliary component is evaporated little.</p> |
