| 摘要 |
1,216,702. Ceramic glaze. WESTERN ELECTRIC CO. Inc. 26 Jan., 1968 [30 Jan. 1967], No. 4219/68. Heading C1M. A ceramic substrate glaze comprises the following components in weightper cent: Al 2 O 3 4-10; SiO 2 38-43, CaO 0-10; BaO 5-18; B 2 O 3 0-10; PbO 13-22; Bi 2 O 3 5-15; TiO 2 0À5-2; K 2 O 0À5-2; As 2 O 3 0À25-1. In making the glaze, Al 2 O 3 , SiO 2 , PbO, TiO 2 and As 2 O 3 are added in the oxide form, CaO, BaO and K 2 O are used in the carbonate form and B 2 O 3 is added in the acid form, and Bi 2 O 3 as Bi(NO 3 ) 3 5H 2 O. The mixed components are heated to- 1350‹ to 1450‹ C. to form a molten glass, which is poured into cold water thereby fragmenting the glass into small particles, and grinding them to a desired particle size, e.g. 0À002 inch in diameter. The glaze can be applied to a high density Al 2 O 3 substrate containing at least 85% by weight of Al 2 O 3 by, for example, spraying as a wet spray with a binder, or in the dry form as a preformed transfer tape. After applying the glaze it is allowed to dry in air and is then fired. Heating is continued to 1000‹ to 1250‹ C. A glaze thickness of 0À0008 to 0À016 inch is. desirable. In an example, a spray composition is prepared from a glass frit and methylmethacrylate dissolved in ethylene glycol monoethylether acetate, which is applied to a 96 wt. per cent Al 2 O 3 substrate. |
