| 摘要 |
PURPOSE:To obtain lightweight ceramic beads having high crushing strength and reduced in abrasion by containing a dielectric material and a vitreous substance and setting a diameter to 0.3-5mm and bulk density to 1.5-2.5g/cm<3>. CONSTITUTION:As a dielectric material, barium titanate having a high dielectric constant or a composition based on barium titanate is used. The amount of a vitreous substance contained in dielectric ceramic beads is within a range of 10-100% by wt. of the dielectric substance. When the contents of the vitreous substance exceeds 100wt.%, the occupying volume of the dielectric substance in dielectric beads is reduced and, therefore, the dielectric constant of beads is lowered and it is not pref. from the aspect of discharge. The particle size of the dielectric ceramic beads is pref 0.3-5mm. In order to reduce the air passing resistance of a packed bed, the shape of the beads is desirably spherical. Further, bulk density is adjusted to 1.5-2.5g/cm<2>. From the aspect of discharge, the volume ratio of the dielectric material to beads is desirably 20% or more. |
