| 摘要 |
PROBLEM TO BE SOLVED: To suppress modification with the lapse of time after mixing a phosphor suspension to manufacture a high quality lamp high in the film strength of a phosphor film by making a metallic oxide contain aluminum oxide with specific surface area set in a specified range, and setting the pH value of the phosphor suspension into a specific range. SOLUTION: The specific surface area of an aluminum oxide is made 1.5-30 m2/g, and the pH value of a suspension is made 8-10. When the major diameter of a metallic oxide is called aμm and the minor diameter is called bμm, it is preferable to satisfy a relational expression of 0.5<=b/a<=1.0. The suspension is a mixture of a phosphor, the metallic oxide serving as a binder, a polyethylene oxide serving as a binder for heightening the viscosity of the phosphor suspension, pure water serving as a dispersion medium, and ammonia serving as a pH conditioner at the weight ratio of 1:0.013:0.009:1.850:0.0001. In this case, the phosphor, metallic oxide and ammonia are added in this order and mixed after dissolving the polyethylene oxide in pure water in an agitating device.
|
