KR950004194B1 - Process for the preparation of pigment attached to chemiluminescence - Google Patents

Abstract

The pigment-attached red light-emitting fluorescent material is produced by (a) dispersing 0.1 g gelatin to 20 ml pure water, and heating the dispersed liquor at 40 'C to make an aq. gelatin soln., (b) adding 100 g Y2O2S:Eu to the gelatin soln., and stirring the mixt. to make a fluorescent material-dispersed liquor (A), (c) dispersing 0.1 g arabin rubber to 100 ml pure water, and heating the dispersed liquor at 40 'C to make an aq. arabis rubber soln., (d) adding 0.3 g Fe2O3 red pigment to the soln., and stirring the mixt. to make a pigment-dispersed liquor (B), (e) mixing the liquors (A and B) to make a pigment-attached fluorescent material (I), and (f) adding 200 g Y2O2S:Eu fluorescent material and (I) to 500 ml pure water, and stirring, filtering and drying the mixt. The produced fluorescent material has a good chrominance and contrast.

Description

Method for producing pigmented phosphor

1 is an enlarged cross-sectional view of a pigmented phosphor, wherein a is for a pigmented phosphor according to a conventional method, and b is for a pigmented phosphor according to the method of the present invention.

2 is a graph showing the emission spectrum of the pigmented phosphor, where a is for the pigmented red light emitting phosphor, b is for the pigmented blue light emitting phosphor, and in each of the figures, a is for the pigmented phosphor according to the conventional method. And b is for the pigmented phosphor according to the method of the present invention.

* Explanation of symbols for main parts of the drawings

1: Pigment Attached Phosphor 2: Pigment

3: binder 4: pigment unattached phosphor

The present invention relates to a method for producing a pigment-containing phosphor, and more particularly, to a method for producing a pigment-containing phosphor having improved luminance and overall phosphor characteristics.

Phosphors for color cathode ray tubes generally satisfy the following conditions for the production of good quality color cathode ray tubes.

1) Have high brightness.

2) Good deterioration.

3) High color purity.

4) Good dispersibility when forming fluorescent film.

In order to satisfy the remaining conditions except for the above 1), a pigment is attached to the surface of each phosphor of red, green, and blue color, which causes each pigment to emit light and external light in some undesired areas. This is because the absorption of light reduces the reflection of light, thereby enhancing the color purity of the phosphor and improving various phosphor characteristics.

By the way, there are many side effects due to the pigment attached in addition to the various advantages described above. One of the biggest problems is a decrease in the luminance of light emitted by the phosphor due to the attachment of non-luminescent pigments. 1 is an enlarged cross-sectional view of a pigmented phosphor, in which A is a pigmented phosphor according to a conventional method. Referring to FIG. 1A, the pigment 2 is attached to the surface of the phosphor 1 by the binder 3, but it can be seen that the binder surrounds the entire surface of the phosphor in a thin film form. This binder film serves to block the light emitted by the phosphor and to lower the luminance. In particular, in the case of the blue light emitting phosphor-linked pigment, the luminance deterioration phenomenon is large, since the amount of the pigment and binder in the blue light emitting phosphor is larger than that of other phosphors.

Table 1 shows the characteristics of the phosphor before the pigment and the phosphor after the pigment is compared.

TABLE 1

* Red phosphor is Y ₂ O ₂ S: Eu, Red pigment particles are iron oxide (Fe ₂ O ₃ ), Blue phosphor is ZnS: Ag, Blue pigment particles are used high-balt blue (CoO · nA1 ₂ O ₃ ) It was.

* In the red-emitting phosphor, the amount of pigment attached is 0.15% by weight of the phosphor, the amount of the gum arabic and gelatin is 0.1% by weight, respectively. 0.4 wt%.

In addition to the pigment-containing phosphor, there are new problems such as detachment of the pigment and fall of the fluorescent stripe when forming the phosphor film, and the dispersibility of the phosphor is not good enough. Therefore, researches in various fields, such as improvement of a pigment attaching method and development of a new pigment, have been actively conducted.

It is an object of the present invention to provide a method for preparing a pigment-containing phosphor, which has a vivid color purity and contrast, as well as a phosphor having no pigment, and which has improved dispersibility and emission luminance when forming a phosphor film.

In order to achieve the above object, in the present invention, in the method of manufacturing a pigment-containing phosphor prepared by attaching a pigment to a surface of a phosphor by using a binder, the pigment-free phosphor is obtained by mixing a pigment-free phosphor and a pigment-free phosphor. A method for producing a pigment-containing phosphor is provided.

In particular, the phosphor is a red light emitting phosphor, and a pigment-free red light emitting phosphor obtained by mixing a non-pigmented red light emitting phosphor and a pigmented red light emitting phosphor obtained by adhering 0.2 to 0.5% by weight of a pigment is provided.

The mixing ratio of the non-pigmented red light-emitting phosphor and the pigmented red light-emitting phosphor may be arbitrarily selected in consideration of the color purity and the size of the light emission luminance. A useful range is 1: 1 to 1: 4, and the pigment is iron oxide (Fe ₂ O _3). ), ZnFe ₂ O ₄ , and cadmium sulfoselenide [Cd (S ₁ -x, Se x), 0 <x <1].

In addition, the present invention provides a method for producing a pigment-containing blue light-emitting phosphor obtained by mixing the above-mentioned phosphor, a blue light-emitting phosphor with no pigment as a blue light-emitting phosphor, and a pigmented blue light-emitting phosphor obtained by adhering 2.0 to 5.0% by weight of a pigment.

The mixing ratio of the pigment mibuchak blue light-emitting fluorescent substance and a pigment attached to the blue light-emitting fluorescent material is preferably 1: 1 to 1: 5, and the pigment is ultramarine blue _{(3NaAl · SiO 2 · Na 2} S 2), charged bit blue (CoO · nA1 ₂ At least one of O ₃ ).

And the binder can be used without limitation, such as gum arabic and gelatin or casein and gelatin.

Hereinafter, a preferred embodiment of the present invention will be described in detail.

(Example 1)

Gelatin 0.lg is dispersed in 200m1 of pure water and heated to 40 ℃ to prepare a gelatin aqueous solution. 100 g of Y ₂ O ₂ S: Eu phosphor is added to the aqueous gelatin solution and stirred until it is uniform with a stirrer to prepare a phosphor dispersion.

Arabia gum 0.lg is dispersed in 100m1 of pure water and heated to 40 ℃ to prepare an aqueous gum arabic solution. 0.3 g of iron oxide (Fe ₂ O ₃ ) red pigment is added to the arabic rubber aqueous solution, and the mixture is sufficiently stirred to prepare a pigment dispersion.

After mixing the obtained pigment dispersion and the phosphor dispersion, the pH is adjusted to 6 while stirring. If the precipitate is left to settle, the supernatant is poured out and the precipitate is washed several times with water. The solid mass is dried at a content of 100 ° C. to obtain a phosphor with iron oxide pigment attached.

200 g of Y ₂ O ₂ S: Eu phosphors with good dispersibility after the ball mill treatment without pigments and the pigments attached thereto were added to 500 m1 of pure water, stirred for 30 minutes, followed by filtration and drying. A pigmented red light emitting phosphor is obtained.

(Example 2)

The same procedure as in Example 1 was carried out, except that the amount of gelatin was 0.15 g, the amount of gum arabic was 0.15 g, and the amount of iron oxide (Fe ₂ O ₃ ) red pigment was 0.4 g.

Pigment-free Y ₂ O ₂ S: Eu phosphor 300g and the pigment-doped phosphor was added to 500 ml of pure water, stirred for 30 minutes and mixed well, and then precipitates were filtered and dried. A light emitting phosphor is obtained.

(Example 3)

Gelatin 0.6g is dispersed in 200m1 of pure water and heated to 40 ℃ to prepare a gelatin aqueous solution. 100 g of a ZnS: Ag phosphor is added to the gelatin aqueous solution, and stirred until uniform with a stirrer to prepare a phosphor dispersion.

0.6 g of gum arabic is dispersed in 100 ml of pure water and heated to 40 ° C. to prepare an aqueous gum arabic solution. ₃ g of cobalt blue (CoO · nA1 ₂ O ₃ ) blue pigment is added to the arabic rubber aqueous solution and sufficiently stirred to prepare a pigment dispersion.

After mixing the obtained pigment dispersion and the phosphor dispersion, the pH is adjusted to 6 while stirring. If the precipitate is left to settle, the supernatant is poured out and the precipitate is washed several times with water. The solid mass is dried at a content of 100 tons to obtain a phosphor having a cobalt blue pigment attached thereto.

Pigment adhered according to the method of the present invention by adding 100 g of ZnS: Ag phosphor and a pigment with phosphor to 500 ml of pure water and stirring for 30 minutes after filtration and drying. A blue light emitting phosphor is obtained.

(Example 4)

Performing the same method as in Example 3, but the amount of gelatin is 0.8g, the amount of gum arabic is 0.8g to obtain a phosphor with a cobalt blue pigment.

A pigment-free blue light-emitting phosphor according to the method of the present invention is obtained by adding 150 g of a pigment-free ZnS: Ag phosphor and a pigment to which the pigment is attached to 500 m1 of pure water, stirring for 30 minutes, and then filtering and drying the precipitate. .

Table 2 shows the color coordinates, light emission luminance and particle size distribution of the pigmented phosphors obtained in the above Examples.

TABLE 2

From the results shown in Table 2, it can be seen that the pigment-containing phosphor prepared according to the method of the present invention has almost the same color purity as the conventional phosphor, but improved luminance.

2 is a graph showing the emission spectrum of the pigmented phosphor, A is for the pigmented red light-emitting phosphor of Example 1, B is for the pigmented blue light-emitting phosphor of Example 3, in each figure a is conventional For the pigmented phosphor according to the method of, b is for the pigmented phosphor according to the method of the present invention.

It can also be seen from FIG. 2 that the luminous luminance of the pigment-attached phosphor according to the method of the present invention is improved as a whole, since the total amount of pigment used in the pigment-attached phosphor of the present invention is reduced.

In addition, the phosphor with phosphor of the present invention can be freely selected by adjusting the mixing ratio of the phosphor with the pigment and the phosphor without the pigment.

Claims (9)

A method for producing a pigment-bearing phosphor produced by attaching a pigment to a surface of a phosphor by using a binder, wherein the pigment-bearing phosphor is obtained by mixing a pigment-free phosphor and a pigment-bearing phosphor. The method of claim 1, wherein the phosphor is obtained by mixing a non-pigmented red luminescent phosphor as a red luminescent phosphor and a pigmented red luminescent phosphor obtained by adhering 0.2 to 0.5% by weight of a pigment. . The method according to claim 1 or 2, wherein the mixing ratio of the non-pigmented red luminescent phosphor and the pigmented red luminescent phosphor is 1: 1 to 1: 4. The method of claim 1 or 2, wherein the pigment is at least one of iron oxide (Fe ₂ O ₃ ), ZnFe ₂ O ₄ and cadmium sulfoselenide [Cd (S _1-x , Se x), 0 <x <1] Method for producing a pigment with a phosphor, characterized in that one. The method of claim 1 or 2, wherein the binder is gum arabic and gelatin or casein and gelatin. The method of claim 1, wherein the phosphor is obtained by mixing a non-pigmented blue luminescent phosphor as a blue luminescent phosphor and a pigmented blue luminescent phosphor obtained by adhering 2.0 to 5.0% by weight of a pigment. . The method for producing a pigment-containing phosphor according to claim 1 or 6, wherein a mixing ratio of the pigment-free blue-emitting phosphor and the pigment-containing blue-emitting phosphor is 1: 1 to 1: 5. The method according to claim 1 or 6, wherein the pigment is at least one of ultramarine (3NaAl.SiO ₂ .Na ₂ S ₂ ) and cobalt blue (CoO.nA1 ₂ O ₃ ). The method of claim 1 or 6, wherein the binder is gum arabic and gelatin or casein and gelatin.