| 摘要 |
PURPOSE:To suppress the peeling of luminous layers without impairing luminous efficiency by forming the first and the second luminous layers in sequence on the inner surface of a bulb made of soda glass and specifying mixed quantities of metal borate and alumina in both luminous layers. CONSTITUTION:A bulb made of soda glass is flow-coated with a suspension containing metal borate and alumina on its inner surface and air-dried to form the first luminous layer. Next, it is flow-coated with the second suspension containing metal borate and alumina and air-dried to form the second luminous layer over the first luminous layer. b>=3a>0 and b<=a<2b are set for the first luminous layer and the second luminous layer respectively, where b% and a% are mixed quantities of metal borate and alumina respectively. The mixed quantities of metal borate in the first luminous layer and the second luminous layer are set within ranges of 2.0-5.0% and 0.5-3.0% respectively. Accordingly, the peeling of luminous layers can be suppressed without impairing luminous efficiency. |
