KR930008117B1 - Phosphorous for crt and process for preparing the same - Google Patents

Abstract

The method comprises (a) heating a mixture of ethylsilicate, alcohol, water and an acid for a predetermined time to obtain a silicon compound which is to be attached to the fluorescent material, and (b) mixing the silicon compound with luminium salt (Al(CO3)39H2O) and zinc salt (ZnSO47H2O) and controlling the pH of the mixture at 6-12 with the addition of ammonia water. The amount of ethylsilicate is 0.2-13 wt.% with respect to 100 wt.% fluorescent material. The amounts of alcohol and water are 20-48 wt.%, respectively. The amount of acid is 0.02-1.5 wt.%. The amounts of aluminium salt and zinc salt are 0.1-0.5 wt.%, respectively.

Description

Phosphor for cathode ray tube and manufacturing method thereof

The present invention relates to a phosphor for a cathode ray tube and a method of manufacturing the same, and more specifically, to the anti-aging and luminous efficiency of the green and blue phosphors used in the color cathode ray tube and the green phosphors used in the monochrome cathode ray tube to improve the luminous efficiency It relates to a conventional phosphor and a method for producing the same.

In general, the fluorescent film for color cathode ray tubes has a structure in which phosphors emitting light of red, green, and blue colors on the inner surface of the glass panel are regularly arranged in the shape of dots or stripes, and a film of light absorbing material such as graphite is deposited on these phosphor array gaps. Has The fluorescent film having such a structure is formed by a photolithography method.

That is, first, a so-called phosphor slurry in which a phosphor is suspended in a polyvinyl alcohol (organic binder) solution containing a dichromate as a photosensitizer is applied to the inner surface of the panel, dried to form a photosensitive resin film, and then exposed through a shadow mask to expose the phosphor. After hardening the photosensitive resin film of a site | part, the unexposed part of the photosensitive resin film | membrane is removed by the image development process by hot water spray etc., and only the exposure part corresponding to the fluorescent substance coating part of the photosensitive resin film | membrane is obtained.

In manufacturing such a fluorescent film, the fluorescent film should prevent the color mixture caused by the incorporation between the phosphors and improve the adhesion and filling density to the phosphors and the panel to prevent the aging of the phosphor and increase the brightness. In order to satisfy this, improvement is required for the composition and manufacturing method of the phosphor slurry or the surface treatment of the phosphor used in the phosphor slurry.

Therefore, in order to obtain a high quality of the fluorescent film, it is conventionally known to attach phosphates such as silicon dioxide, magnesium, zinc, calcium, aluminum, etc. to the surface of the phosphor to improve dispersibility in the phosphor slurry, thereby obtaining a good fluorescent film.

In addition, potassium silicate (K ₂ O.nSiO ₂ ), Na ₄ P ₂ O ₇ · 10H ₂ O, Al (NO ₃ ) ₃ · 9H ₂ O, ZnSO ₄ · 7H ₂ O and NH ₄ OH and the like were mixed and used.

However, the phosphor surface-treated in this manner has a problem that the adhesion of the phosphor to the panel, the filling density is lowered, the luminescence is also lowered and the fluorescent color is not good.

Disclosure of Invention It is an object of the present invention to provide a surface-treated phosphor for providing a phosphor film having improved adhesion and filling density to a panel in view of the above problems, and a method of manufacturing the same.

In order to achieve the above object, the phosphor of the present invention is characterized in that the phosphor for cathode ray tube, an alkyl silicate attached to the phosphor and an anode for cathode ray tube made of alkali, is formed by adding an acid instead of the alkali.

In addition, the manufacturing method of the phosphor of the present invention is a method for producing a cathode ray tube phosphor consisting of a cathode ray tube phosphor and a Si compound attached to the phosphor, the step of obtaining a Si compound by heating ethyl silicate, alcohol, water and acid for a predetermined time; And a mixture of the obtained Si compound with aluminum and zinc salts and adjusting the pH with NH ₄ OH.

As the alkyl silicate used in the present invention, methyl silicate or ethyl silicate is preferred as it is easy to hydrolyze, methanol, ethanol, isopropyl alcohol, butanol, etc. are used as alcohol, and hydrochloric acid or nitric acid is used as acid. , ZnSO ₄ · 7H ₂ O as the zinc salt, Al (100 ₃ ) ₃ · 9H ₂ O, etc. were used as the aluminum salt.

The amount of the raw material used in the present invention is 0.2 to 13% by weight based on 100% by weight of the phosphor, the amount of alcohol and water is 20 to 48% by weight, the amount of acid is 0.02 to 1.5% by weight, The amount of aluminum salt and zinc salt was 0.1 to 0.5% by weight, respectively, and a small amount of NH ₄ OH was added.

In addition, the phosphors used in the present invention include zinc sulfide-based phosphors based on ZnS, for example, ZnS: Cu, Al, ZnS: Au, Cu, Al, ZnS: Ag, ZnS: Ag, Al, ZnS Zn, ZnS: Au, and ZnS: Ag, Cl and the like.

Hereinafter, the manufacturing method of the phosphor of the present invention will be described.

First, ethyl silicate is added to pure water and fully suspended. Next, ethanol is added to the suspension to dissolve the ethyl silicate. Subsequently, phosphors were added, and ZnSO ₄ · 7H ₂ O as the zinc salt and Al (NO ₃ ) ₃ · 9H ₂ O as the aluminum salt were added at 0.1 to 0.5% by weight, respectively, based on the total weight of the phosphor. In addition, the pH was adjusted to 6 to 12 using NH ₄ OH to a pH-adjusting alkali.

Referring to the preferred embodiment of the present invention.

Example 1

5 g of ethyl silicate is added to 20 ml of pure water, and the suspension is sufficiently suspended. 20 ml of ethanol is added to the obtained suspension to dissolve the ethyl silicate. 0.05 ml of nitric acid (HNO ₃ ) was added thereto, and stirred for 25 hours while heating at 50 ° C. to obtain a Si compound. Then, a suspension obtained by suspending 1000 g of ZnS: Cu and Al phosphors in 2 l of pure water is added to the solution, and a 10% aqueous zinc sulfate solution (0.1% by weight of zinc relative to 100% by weight of phosphor) is gradually added and stirred for about 20 minutes.

Then 10% aqueous aluminum nitrate solution (0.1% by weight of aluminum with respect to 100% by weight of phosphor) is added slowly, and then a small amount of aqueous NH ₄ OH solution is added to adjust the pH to 8.

The suspension thus obtained is allowed to stand for 1 hour to precipitate the phosphor to which the Si compound microparticles are attached, washed several times with pure water, dehydrated, and dried by heating at a temperature of 150 ° C. for 5 hours.

After drying, the phosphor mass was sieveed to obtain a desired phosphor.

Example 2

The phosphor of the present invention was obtained in the same manner as in Example 1, using 10 g of ethyl silicate.

As described above, the phosphor having the surface treatment material adhered to the surface of the phosphor has superior adhesive strength, greatly improved packing density, and increased luminescence brightness by about 5 to 10% as compared with the conventional silicate-based surface treated phosphor.

As described above, according to the present invention, the phosphors surface-treated with alkyl silicates have excellent dispersibility, and when used in the phosphor slurry, the packing density is greatly improved, the adhesion is excellent, the aging can be prevented, and the luminous luminance is also improved.

Claims (4)

A cathode ray tube phosphor comprising a cathode ray tube phosphor, an alkyl silicate attached to the phosphor and an alkali, wherein an acid is added instead of the alkali to form a cathode ray tube phosphor. The phosphor for cathode ray tube according to claim 1, wherein the amount of acid is 0.02 to 1.5% by weight based on 100% by weight of the phosphor. A method for producing a cathode ray tube phosphor comprising a cathode ray tube phosphor and a Si compound attached to the phosphor, further comprising the step of heating an ethyl silicate, alcohol, water and an acid for a predetermined time to obtain a Si compound. Method for producing a phosphor. According to claim 3, wherein the amount of ethyl silicate is 0.2 to 13% by weight based on 100% by weight of the phosphor, the amount of the alcohol and water is 20 to 48% by weight, respectively, the amount of the acid is 0.02 to 1.5% by weight And the amount of the aluminum salt and the zinc salt is 0.1 to 0.5% by weight, respectively, and the amount of NH ₄ OH is a small amount.