| 摘要 |
<p>PURPOSE:To reduce the formation of pores in a molding glass and to prevent the coalescence of the pores in the glass in the step of calcining the glass by specifying the average grain diameter of the glass powder within a specified range. CONSTITUTION:The average grain diameter of the glass powder are specified to 5.5mum+ or -1mum. The material of the glass is adapted to be specified to that having a crystallization temperature of 700 deg.C+ or -20 deg.C. There is used, for example, a glass powder which contains approx. 60wt% of ZnO, approx. 22.5wt% of B2O2, approx. 12.5wt% of SiO2 and approx. 5wt% of PbO in composition and 5.5mum of average grain diameter. Thus, the formation of pores in the molding glass can be reduced, the coalescence of the pores in the glass in the step of calcining the glass, and the deterioration of the withstand voltage of the glass powder caused by the discharge in an atmosphere with the pores can be prevented.</p> |
