| 摘要 |
PURPOSE:To permit uniform coating of phosphor film having the first layer composed of super minutely powdered substance such as titanium disulfide by forming a film made of super minutely powdered substance on the inner wall of a glass bulb by using the aqueous solution of polyethylene oxide as water-soluble binder. CONSTITUTION:Aqueous solution of polyethylene oxide is prepared, and a suspension is produced by adding said aqueous solution of oxide into titanium dioxide having an average particle diameter of 1mu or less e.g. 0.3mu. Pure water is added into said suspension, to make it less viscous, and the suspension is applied onto the whole surface of the inner wall of a glass bulb to form a thin film of the first layer. Said film is heated for instance at 500-600 deg.C to completely combust binder and is cooled thereafter. Then, white phosphor substance is applied onto the whole surface of the above film to form the luminous layer as the second layer. Thus, coating of superior film surface having the first layer made of super fine powdered substance can be achieved. |
