| 摘要 |
PURPOSE:To obtain raw material powder for a BaTiO3-based semiconductor porcelain composition of a low specific resistance by using specific BaTiO3, SrTiO3, CaTiO3 and PbTiO3 as principal components and further specifying a composition containing a semiconductor conversion agent and additives. CONSTITUTION:To a principal component composed of 45-85mol% BaTiO3, 1-20mol% SrTiO3, 5-20mol% CaTiO3 and 1-20mol% PbTiO3, are further added 0.05-0.14mol% oxide such as Nb or Sb, 0.02-0.06mol% CuO and 0.7-2.0mol% SiO2. Thereby, raw material powder for a BaTiO3-based semiconductor porcelain composition is obtained. In the process, the aforementioned BaTiO3 is powder composed of skeletal secondary particles, having open cells and 150-250mum average particle diameter, containing <=5wt.% particles with <=50mum particle diameter and composed of mutually connected primary particles having <=0.2mum particle diameter. The SrTiO3 is powder composed of skeletal secondary particles, having open cells and 70-180mum average particle diameter with 20-30m<2>/g BET specific surface area and composed of primary particles having <=0.1mum particle diameter. Particle characteristics of the PbTiO3, as necessary, are also specified. Thereby, the objective raw material powder for the semiconductor porcelain composition, having a specific resistance value as low as <=about 10OMEGAcm and excellent in withstand voltage and alpha-value is obtained. |
