KR920004165B1 - Process for the prepartion of fluorescent substance - Google Patents

Abstract

The blue-pigment adhered fluorescent material is produced by (a) mixing a water-soluble mixture of 100 wt.% blue fluorescent material (I) and 0.005-1 wt.% acryl emulsion with a pigment solution of pigment powder (II), water and PVA, (b) controlling the mixture with acetic acid, sulfuric acid or nitric acid to become pH 3-7, and (c) washing and drying it. The material (I) is pref. ZnS:Ag:Cl or ZnS:Ag Al, and the powder (II) is pref. 3NaAl SiO2 Na2S2, CoO nAl2O3 or CoO nSnO2. The fluorescent material is used in the mfr. of a screen for CRT.

Description

Pigment attached phosphor manufacturing method

The accompanying drawings are graphs illustrating the relationship of dispersibility according to the size of the pigment-adhesive body and the pigment-free phosphor for explaining the present invention.

The present invention relates to a method for preparing a blue pigment-containing phosphor having a compositional formula ZnS: Ag, which is used for the preparation of cathode ray tube fluorescent surface of color television, and has a uniform pigment coating state and no aggregation between phosphor particles, which is good in dispersibility. The present invention relates to a method for producing a blue pigment-containing phosphor having good affinity.

The red, blue, or green phosphors used in the manufacture of the fluorescent surface of the cathode ray tube for color television have unwanted wavelengths in the emission spectrum of each phosphor due to the filter effect of these pigment particles when the red pigment, blue pigment, and green pigment are attached to the phosphor, respectively. The light emission color becomes clear by absorbing or reducing light, and when the fluorescent film is made in this way, the reflectance of the fluorescent surface is lowered by the absorption effect of external light by the pigment, thereby greatly improving the image quality.

Therefore, the red, blue, and green phosphors used in the cathode ray tube for color telegraph should be coated with the pigment particles on the surface of the phosphors. In this case, (1) Pigment particles with arabic rubber or PVP are used. And a method of making a gel with gelatin attached thereto (Japanese Patent No. 50-56146), and (2) producing a water-soluble acidic polymer and a water-soluble basic polymer in place of PVP and gelatin in the method of (1), respectively. Method (Japanese Patent No. 51-77649), and (3) a method of preparing cationic acrylic monomers and anionic acrylic emulsions in place of PVP and gelatin in method (1), respectively (Japanese Patent 56-35707).

On the other hand, the pigment-adhesive body first, the adhesion of the pigment particles and the phosphor particles is strong, there should be no pigment detachment when combining the phosphor coating liquid. Secondly, it should be uniformly applied on the surface of pigment particle and phosphor particle and there will be less aggregation when pigment is attached. Third, attach the appropriate amount of oriental medicine in consideration of the decrease in brightness and the improvement of reflectance of the mold particles due to the pigment adhesion. Fourth, characteristics such as high affinity with the combination solution of the pigment-containing fluorescent substance are required, and the reduction of luminance at the time of pigment deposition, the suppression of aggregation occurrence, the firm adhesion of the pigment and the affinity with the combination solution are improved. It is an important issue to be addressed.

In particular, in the case of agglomeration of the phosphor or lack of affinity with the combination solution, the stripe characteristics are poor in the manufacture of the fluorescent film, or fine bubbles are generated in the combination, resulting in pin holes in the manufacture of the phosphor film. ) Has a direct effect on the fluorescent film, such as a low adhesion strength to the face plate (face plate).

Therefore, in the present invention, there is no agglomeration even after the coating of the pigment, and the pigment has excellent affinity with the combination solution at the time of the combination, so that there is no generation of fine bubbles, and the adhesion strength is excellent. There is this.

Embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The accompanying drawings are graphs illustrating the dispersibility relationship with phosphors without pigments in order to explain the characteristics of the phosphors with pigments according to the present invention.

First, a water-soluble mixture of a blue phosphor and an acrylic emulsion as a binder is prepared, that is, the pure water and the blue mold are uniformly stirred with a stirrer or the like, and then a predetermined acrylic is added, mixed for a sufficient time, and then a blue pigment mixed with PVA. Pour the solution.

After mixing for a certain time, the pH is adjusted to 7-3 with acetic acid, nitric acid, sulfuric acid, etc., and then washed 1 to 2 times, followed by drying and sieving to form the phosphor with blue pigment of the present invention.

The pigment solution at this time is manufactured by the following method.

1: 7: 20 by weight ratio of blue pigment, pure water and ball (Ball) is ball milled for 1 to 2 days, and then diluted with pure water to obtain a pigment dispersion, and then a predetermined amount of PVA is uniformly mixed therein to prepare.

That is, in the present invention, in order to reduce the aggregation between the phosphor particles generated by the use of a binder during pigment coating and to increase the affinity with the combination solution containing PVA as a main component, it is important to share PVA simultaneously with the acrylic emulsion as a binder. The amount of acrylic emulsion and PVA in the binder is in the range of 0.005-1 wt% and 0.001-0.1 wt% with respect to 100 wt% of the phosphor.

Examples of the blue phosphor that can be used as the blue pigment-containing phosphor of the present invention include CaWO ₄ , ZnS; Ag, Cl, ZnS; Ag, Al, 2CaO, MgO, 2SiO, Ce, Y ₂ O ₂ S: Tb, (Ca, Mg) SiO ₃ : Ti, and the like, and these particle diameters are appropriately 3 to 15 µm.

In addition, the pigment particles used in the blue pigment phosphors include ultramarine blue (3NaAl.SiO ₂ .Na ₂ S ₂ ) and blue blue (Fe ₄ [Fe (CN ₆ ] ₃ .nH ₂ O cobalt blue (CoO.nAl ₂ O ₃ ). , CoO · nSnO ₂ , copper emulsion (CuS), and the like, and the average particle diameter is preferably 0.5 μm or less.

The best combination of phosphors with blue pigment for practical use in manufacturing fluorescent film of cathode ray tube for color television is ZnS: Ag, Cl or ZnS: Ag, Al phosphor and cobalt blue or navy blue pigment.

The amount of pigment particles with respect to the amount of phosphor depends on the kind of phosphor, the kind of pigment particles, the desired increase in reflectance, etc., but is usually 15 wt% or less (about 0.05 to 10 wt%) with respect to 100 wt% of the phosphor. If no more than 15wt%, the luminance of the phosphor is considerably lowered.

Hereinafter, the present invention will be described in more detail with reference to the following examples.

EXAMPLE

ZnS: Ag, Cl blue phosphor, 350g of zinc sulfide as a parent, revived with silver, and activated with chlorine, is completely dispersed in 1400ml of pure water using a stirrer, and 0.5ml of acrylic emulsion solution is added thereto.

Thereafter, the mixture is allowed to stir sufficiently, the phosphor particles are allowed to settle, and the supernatant is washed once using a gradient method, and the pigment dispersion prepared by stirring is filled again with pure water as the height of the original water surface.

At this time, the pigment dispersion is prepared by the following method.

2 wt% of the pigment per 100 wt% of the phosphor is ball milled for 1 to 2 days with a ratio of pigment: pure water: glass ball: 1: 7: 20, and then diluted with an appropriate amount of pure water to obtain a pigment dispersion. While dispersing this using a stirrer, 0.05ml of PVA solution is added to mix the pigment and PVA evenly.

After the pigment dispersion was added, the mixture was sufficiently stirred to completely mix the pigment preparation prepared with PVA and the phosphor solution added with acrylic emulsion, and then adjusted to PH 7 using acetic acid to complete the pigment deposition. After water separation and drying, the resultant is sieved through a 400 mesh sieve to obtain a blue pigment-containing phosphor.

The blue pigment-attached phosphor prepared in this Example has a very good pigment coating state and has a much more uniform coating of the surface of the phosphor particles than the conventional one using the same amount or more of pigments. As illustrated in the figure, the dispersibility is good, and the affinity with the combination solution is excellent, and it has very good characteristics when forming a fluorescent film.

In the CRT manufactured using the present phosphor, the fluorescent film characteristics and the screen test characteristics were found to be better than those of the conventional ones. The results of the measurement are shown in Tables 1 and 2.

TABLE 1

Membrane Property Measurements

에 비해 155

로서 매우 높은 것으로 나타난다.In the case of the characteristic of the fluorescent film, the stripe shape is better than the conventional one, so it is more linear and the adhesive strength is also existing.

Compared to 155

As very high.

TABLE 2

Screen test results

In the screen test, all the measurement items such as WiB, Ib, luminance, and color coordinates are included within the normal characteristic range, and the overall phosphor characteristic is very good.

Example 2

120 g of ZnS: Ag, Al blue phosphor, which is zinc sulfide as a parent and silver co-activation, is dispersed in 480 ml of pure water, and then 1 ml of an acrylic emulsion solution is added to 100 wt% of phosphor, and the mixture is sufficiently stirred to be mixed with the phosphor.

Next, a prepared pigment dispersion is added, mixed with sufficient time, and then adjusted to PH 3 using nitric acid to prepare a pigment-containing blue phosphor.

The pigment dispersion is prepared in the same manner as in Example 1 except that the amount of PVA is reduced to 0.1 ml.

The blue pigment with phosphor prepared in this way also has a good surface coating state, has a small aggregation, good dispersibility, and good affinity with the combination solution, resulting in a strong adhesion on the face plate surface when applied to the cathode ray tube panel. It has the same properties as the product of Example 1.

As described above, in the case of producing the pigment-containing phosphor by the production method of the present invention, various properties required for the pigment-containing phosphor, in particular, in terms of improving dispersibility, affinity with the combination solution, and uniform application of the pigment particles Pigmented phosphors with satisfactory improved properties can be obtained.

That is, the particle size distribution before and after the pigment coating is the same and there is no aggregation at all, so that a uniform and dense stripe can be formed in the manufacture of the fluorescent film, and PVA, which is the main component of the preparation, is used as the binder for the pigment coating. The high affinity of the present invention results in the absence of microbubbles in the preparation of the phosphor coating solution and the high adhesion strength to the face plate of the cathode ray tube, thereby preventing the stripping of the stripe at a prescribed exposure amount.

Claims (2)

A silver-reactive chlorine co-activated zinc sulfide blue phosphor or a silver-activated aluminum co-activated zinc sulfide blue phosphor was prepared with a solution of 0.005 to 1 wt% of an acrylic emulsion per 100 wt% of the phosphor, and cobalt blue, a pigment, 100 wt% A pigment-attached phosphor prepared by attaching a pigment to the surface of the phosphor particles by adjusting the pH to 7 to 3 while preparing a uniformly mixed pigment solution by adding 0.001 to 1wt% of PVA per sugar, and mixing the two solutions evenly. Manufacturing method. The method according to claim 1, wherein the amount of cobalt blue which is a blue pigment is in the range of 0.05 to 10 wt%.

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