Fluorescent material and its preparation

Abstract

Abstract PURPOSE:To prepare a fluorescent material having excellent dispersibility and screening characteristics, resistant to the lowering of fluorescent intensity by baking process, etc. and resistnat to the discolration caused by external impurities, by covering the particle of the fluorescent material with a continuous SiO2 layer. CONSTITUTION:Almost whole surface of a fluorescent particle is coated with a thin film of SiO2 having a thickness of 0.5-70mmu. The coating is carried out by mixing the fluorescent particles, pure water, and a solution of SiO2 obtained by dissolving SiO2 in an alkaline solution (choline, tetramethylammonium hydroxide, etc.), and evaporating to dryness. Since the individual particle of the fluorescent material is almost completely coated with SiO2, the fluorescent material has excellent dispersibility and is resistant to the lowering of the fluorescent intensity by the following baking process, etc. The fluorescent particles thus prepared are useful for the color- TV tube, fluorescent lamp, etc.

Inventors

• 👤 Minoru Watanabe
• 👤 Mitsuhiro Oikawa
• 👤 Toshio Nishimura
• 👤 Masao Asada
• 👤 Masao Tezuka
• 👤 Tsurahide Cho

Bibliographic Details