Nichia Kagaku Kogyo K.k.

Nichia Chemical Industries, Limited

Shoichi Bando

Yoshikatsu Aihara

Ichiro Takeoka

Katsunori Uchimura

Tomokazu Suzuki

Miyuki Sumitomo

Masahiro Yoneda

Akio Fujii

Yoshiaki Shizuki

Misa Furuoka

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

In a cathode-ray tube phosphor, a layer consisting of a substantially uniform SiO.sub.2 film or an organic film consisting essentially of at least one type of a polymer selected from the group consisting of an acrylic resin, gelatin, alginic acid, chitosan, and a urea resin is formed as a first layer on the surface of a phosphor particle, and a layer containing at least one type of a metal selected from the group consisting of Zn, Al, and an alkali earth metal and at least one member selected from the group consisting of a colloidal silica, an alumina sol, and a titania sol each having a particle size of 50 nm or less is formed as a second layer on the first layer. This phosphor is excellent in oxidation resistance and dispersibility.

Method of manufacturing a cathode ray tube phosphor screen

A cathode-ray tube phosphor is manufactured by coating, on the surfaces of phosphor particles, a mixture of a metal alginate containing at least one type of a metal selected from the group consisting of Zn, Al, and an alkali earth metal and at least one type of a water-soluble binder selected from the group consisting of gum arabic, gelatin, polymethacrylamide, and polyvinyl alcohol.

Cathode-ray tube phosphor

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.

Method of reclaiming phosphor

In a phosphor for a cathode-ray tube, a composition containing SiO.sub.2 and at least one element selected from the group consisting of indium, zirconium, and antimony is adhered on the surfaces of phosphor particles.

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Shoichi Bando