| 摘要 |
PURPOSE:To facilitate the removal of impurities by a method wherein impurities such as iron and the like are removed from slurry, which is prepared by wet- disperse the raw material of ceramic substrate at low viscosity and, after the viscosity of the slurry is enhanced, the slurry is wet-dispersed and then formed into sheet. CONSTITUTION:Various raw materials of ceramic substrate mixed with binder, plasticizer and solvent are charged in a ball mill so as to wet-disperse in order to produce lowly viscous slurry having the viscosity of 1,000cp. After the completion of dispersion, the resultant slurry is discharged in a vacuum tank so as to remove un-dispersed matter in the slurry during discharging process and then remove iron in the slurry by the attraction with an electromagnet device provided in discharging course. Next, the resultant slurry added with plasticizer consisting of PVB and DBP in the raw materials is wet-dispersed again with an agitator so as to turn the viscosity of the slurry at the beginning of the agitation into 10,000cp. During the agitation, bubbles are removed under vacuum and, at the same time, some part of the solvent is also removed, resulting in turning the viscosity of the slurry into 30,000cp finally by vacuum deaeration. The resultant slurry is formed into sheet and dried. |
