Nichia Chemical Industries, Limited

Nichia Kagaku Kogyo K.k.

Yoshikatsu Aihara

Shoichi Bando

Katsunori Uchimura

Tomokazu Suzuki

Yoshiaki Shizuki

Electrolytes are attached to fluorescent particle surfaces to prevent open spots in cathode-ray tube coatings dried at high temperatures. Electrolytes that are sulfates, nitrates, or chlorides of alkali or alkaline-earth metals are added to a liquid suspension of fluorescent particles which have passed through a cleaning step. Electrolytes are added to the suspension to make the conductivity of the clear top liquid greater than 30 .mu..OMEGA..sup.-1 cm.sup.-1. The fluorescent particle preparation process is finished with a final dehydration and drying step.

Cathode-ray tube fluorescent material and its method of manufacture

A method of reclaiming a phosphor from a recovered phosphor slurry containing carbon, a bichromate, and polyvinyl alcohol, comprises, (a) a decomposition treatment step of adding an alkali to the recovered phosphor slurry after the slurry is heated to prepare a phosphor suspension having an alkali concentration of 0.5N or less in the slurry, and adding an oxidizing agent in an amount of 1.0 to 20.0 wt % with respect to a dry solid component of the suspension, (b) a weak acid treatment step of separating a phosphor from the suspension, and adding a weak acid to a suspension obtained by adding water to the separated phosphor, thereby adjusting a pH to be 3.0 to 5.0, and (c) a surface treatment step of treating the surface of the phosphor separated from the suspension.

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Anan, Japan

Yoshikatsu Aihara