Method of forming coated layer of fluorescent substance on inner surface of bulb
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsHitoshi Yamazaki, Hiroshi Ito
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Abstract
Method for coating fluorescent material on the inner surface of a bulb using a coating lacquer comprising an aqueous suspension of the finely divided fluorescent material, an organic water soluble polymer, a surfactant, and colloidal alumina as a binder, the improvement which comprises incorporating boric acid and hydrogen peroxide in the suspension. When the coated lacquer is burned out by heating the bulb, the boric acid melt coats the alumina binder to render same inactive for gas absorption and the hydrogen peroxide accelerates the combustion or burning out of the organic polymer and surfactant from the coated lacquer.
Claims9
In a method of forming a coated layer of a fluorescent substance on the inner surface of a bulb which comprises coating a suspension incorporating a fluorescent substance, an organic water soluble polymer, a surfactant, a fine powdery aluminum oxide as binder, and a bulb heat-treating step of burning out said organic water soluble polymer and said surfactant from the coated layer, the improvement which comprises incorporating boric acid and hydrogen peroxide or a precursor thereof in said suspension.
Dependencies are inferred from the claim text.