JPS598380B2 - Manufacturing method of pigmented phosphor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a phosphor whose surface is coated with pigment particles (hereinafter referred to as a "pigmented phosphor"), and more particularly to a method for producing a phosphor for use in cathode ray tubes for color television. The present invention relates to a method for producing a red-emitting phosphor with red pigment particles.

As is well known, when blue pigment particles, green pigment particles, and red pigment particles are attached to the particle surfaces of a blue-emitting phosphor, a green-emitting phosphor, and a red-emitting phosphor, respectively, of a cathode ray tube for color television, they Due to the filter effect of the pigment particles, part of the visible range of the emitted light spectrum is cut off, making the emitted light color clearer.Furthermore, the reflected light is reduced due to the absorption effect of external light due to the pigment coloring of the fluorescent film. This dramatically improves the contrast of images (Japanese Patent Laid-Open No. 50-5
No. 6146).

This pigmented phosphor is produced by attaching pigment particles to the surface of the phosphor particles using an adhesive such as a mixture of polyvinylpyrrolidone and gelatin, a mixture of gum arabic and gelatin, etc. Japanese Patent Publication No. 50-15614
No. 6, JP-A No. 53-5088, etc.).

In pigmented phosphors, it is important that the pigment particles adhere uniformly and firmly to the surface of the phosphor particles.
In general, pigmented phosphors obtained by the above-mentioned conventional manufacturing method using adhesives have problems in terms of uniformity of pigment particles on the surface of the phosphor particles due to the use of adhesives. . That is, the use of an adhesive tends to cause the pigment particles to aggregate with each other, which impairs the uniformity of the pigment particles on the surface of the phosphor particles. Pigmented phosphors, in which pigment particles aggregate with each other and do not adhere uniformly to the surface of the phosphor particles, require the use of a large amount of pigment particles in order to obtain a certain specific reflectance. As a result, a significant decrease in brightness occurs. Furthermore, in general, pigmented phosphors in which the pigment particles agglomerate frequently and the pigment particles do not adhere uniformly to the surface of the phosphor particles do not have sufficient adhesion strength of the pigment particles. The uniformity of pigment particles on the surface of the phosphor can be considerably improved by considering the manufacturing method such as the selection of adhesive (for example, when the above-mentioned mixture of gum arabic and gelatin is used as the adhesive) (It is possible to obtain a pigmented phosphor with better uniformity of pigment particles on the surface of the phosphor particles than when using the above-mentioned mixture of polyvinylpyrrolidone and gelatin), and as long as an adhesive is used, this phosphor The uniformity of pigment particles on the surface of particles is always a problem. As mentioned above, conventionally, pigmented phosphors are manufactured by attaching pigment particles to the surface of phosphor particles using an adhesive. Phosphors have always had a problem with the uniformity of pigment particles on the surface of the phosphor particles.

This problem of uniformity of pigment particles on the surface of phosphor particles cannot be fundamentally solved as long as an adhesive is used. Under these circumstances, we developed a manufacturing method that is fundamentally different from the conventional manufacturing method using adhesives, which allows easily obtaining a pigmented phosphor in which pigment particles are extremely uniformly adhered to the surface of the phosphor particles. A method is desired. However, such a manufacturing method has not been known so far. According to the present invention, it is possible to obtain a red-emitting phosphor with red pigment particles in which red pigment particles are extremely uniformly adhered to the surface of the red-emitting phosphor particles. It is an object of the present invention to provide a method for manufacturing a pigmented phosphor that is fundamentally different from the above-mentioned conventional manufacturing method using an adhesive. Traditionally, red pigment particles (α-Fe2O3) have been known as excellent red pigment particles used in the red light-emitting phosphor of cathode ray tubes for color television (Japanese Patent Laid-open No. 14177/1983), but the present inventors have Various studies have been conducted on methods of attaching α-Fe2O3 red pigment particles to light-emitting phosphors.

As a result, instead of attaching the pre-formed α-Fe2O3 red pigment particles to the red-emitting phosphor using an adhesive as in the conventional method described above, they were first chemically precipitated with the red-emitting phosphor. Iron hydroxide (l) [Fe(0H)2
] By supplying oxygen to the dispersion, α
A red-emitting phosphor to which iron monoxide hydroxide () [α-FeO(0H)] is attached is obtained, and then this α-FeO(0H)
By firing the red-emitting phosphor to which α-Fe2O3 has adhered to the surface of the red-emitting phosphor particles to generate αFe2O3 on the surface of the red-emitting phosphor particles, a pigmented phosphor with α-Fe2O3 red pigment particles extremely uniformly adhered to the surface of the red-emitting phosphor particles can be obtained. The inventors discovered that the present invention can be obtained and completed the present invention. The method for producing a pigmented phosphor of the present invention involves supplying oxygen to a dispersion of a red-emitting phosphor and chemically precipitated Fe(0H)2 to transform Fe(0H)2 into α-FeO(
0H), then separate a mixture of α-FeO(0H) and a red-emitting phosphor from this dispersion, and then calcining this mixture at a temperature of 250 to 750°C in an oxidizing atmosphere to emit red light. α-FeO (20
H) is α-Fe2O3.

The present inventors further investigated the method for producing the pigmented phosphor of the present invention described above.

As a result, instead of firing the mixture of α-FeO(0H) and the red-emitting phosphor obtained in the method for producing a pigmented phosphor of the present invention as is, this mixture was heated to a powder containing iron sulfate containing metallic iron. )(FeSO4) in an aqueous solution and supplying oxygen to this aqueous solution, α-FeO(0H
) is aged, and then the aged α-Fe obtained
When a mixture of O(0H) and a red-emitting phosphor is fired in the same manner as above, the resulting pigmented phosphor has α-Fe2O3 red pigment particles extremely uniformly attached to the surface of the red-emitting phosphor particles. It has been found that the pigmented phosphor has a higher degree of red coloring than the pigmented phosphor obtained by the above-mentioned manufacturing method of the present invention. Another method for producing a pigmented phosphor of the present invention is the method for producing a pigmented phosphor of the present invention in which an αFeO(0H) ripening step is further added to the above method for producing a pigmented phosphor of the present invention. Chemically precipitated Fe(0H)
Oxygen is supplied to the dispersion of 2 to convert Fe(0H)2 into α-Fe.
O(0H), and then α-FeO(0H) from this dispersion.
) and a red-emitting phosphor are separated, and this α-FeO
(0H) and a red-emitting phosphor containing metallic iron.
α-FeO(0H) is aged by placing it in an sO4 aqueous solution and supplying oxygen to this aqueous solution, and then a mixture of aged α-FeO(0H) and a red-emitting phosphor is separated from this aqueous solution. Then, this aged α-Fe
A mixture of O(0H) and a red-emitting phosphor is fired at a temperature of 250 to 750°C in an oxidizing atmosphere to remove aged α-FeO(0H) attached to the surface of the red-emitting phosphor particles.
~Fe2O3.

The present invention will be explained in detail below. In the pigmented phosphor of the present invention, Fe(0
H) A dispersion of 2 is prepared.

This dispersion is generally prepared by adding NaOH. It is prepared by adding and mixing an aqueous hydroxide solution such as KOH to form a Fe(0H)2 precipitate. However, the method is not limited to this method, and for example, first, the Fe salt () aqueous solution and the hydroxide aqueous solution are mixed to form a Fe(0H)2 precipitate, and a red light-emitting phosphor is added to the precipitate. There are no particular restrictions on the method of preparation as long as a dispersion in which the luminescent phosphor and chemically precipitated Fe(0H)2 coexist can be obtained.

The chemically precipitated Fe(0H)2 particles are significantly finer than the red-emitting phosphor particles, and therefore, in this dispersion, the Fe(0H)2 fine particles are susceptible to interparticle attraction, physical adsorption, etc. Therefore, it is thought that it is attached to the surface of the red-emitting phosphor particles. Next, oxygen is supplied into the dispersion liquid to oxidize Fe(0H)2 in the dispersion liquid and α-FeO(0H)2 in the dispersion liquid is oxidized.
H).

Oxygen is supplied by introducing air bubbles, oxygen bubbles, etc. into the dispersion liquid, but air bubbles are generally used from an economic point of view. Further, it is preferable that the temperature of the dispersion liquid be maintained at about 30 to 70° C. during oxygen supply. By supplying this oxygen, Fe(0H)2 is oxidized to α-FeO(0H), and the reaction is expressed by the following formula.

The particle size of α-FeO(0H) produced in this way changes depending on various conditions (for example, if the oxygen supply rate is increased and the oxidation rate is increased, α-FeO(0H) is
The nucleation of 0H) is promoted and the particle size becomes smaller), which are generally significantly finer than red-emitting phosphor particles.

Therefore, the generated α-FeO(0H) fine particles are Fe
It is thought that instead of (0H)2, it adheres to the surface of the red-emitting phosphor particles due to interparticle force, physical adsorption, or the like. Note that the production of α-FeO(0H) by the above-mentioned supply of oxygen can be performed, for example, by adding NaOH. Fe(0H) as described above is prepared by adding an aqueous hydroxide solution such as KOH to form Fe(0H)2 precipitate and converting this to α-FeO(0H).
It can also be carried out simultaneously with the preparation of a dispersion of 0H)2 and a red-emitting phosphor.

Next, a mixture of α-FeO(0H) and a red-emitting phosphor is separated from the above dispersion.

The mixture of α-FeO(0H) and red-emitting phosphor is separated by leaving the dispersion to precipitate the mixture of α-FeO(0H) and red-emitting phosphor, and then decanting the supernatant liquid. This is done using common separation methods such as removing the After separation, the resulting mixture is washed with water, dehydrated, and then dried. In the thus obtained mixture of α-FeO(0H) and a red-emitting phosphor, the α-FeO(0H) fine particles form a red-emitting phosphor by interparticle force, physical adsorption, etc., as described above. It is thought that it is attached to the particle surface.

Next, the mixture of α-FeO(0H) and red-emitting phosphor obtained as described above is filled into a heat-resistant container such as a quartz crucible or an aluminum crucible, and fired to obtain the desired α-Fe2
A red-emitting phosphor with O3 red pigment particles is obtained.

Firing is performed at 250 to 750°C in an oxidizing atmosphere such as air.
Perform at a temperature of As a result of this firing, αFeO(0H) attached to the surface of the red-emitting phosphor is dehydrated and becomes α-Fe2O.
It becomes 3.

The reaction is expressed by the formula below. The above firing conditions must be strictly observed.

If firing is carried out in an atmosphere other than an oxidizing atmosphere, α-Fe2O3 is not produced, and therefore the desired pigmented phosphor cannot be obtained. Furthermore, when the firing temperature is lower than 250°C, the above dehydration reaction does not occur;
When the temperature is higher than 0 DEG C., the generated .alpha.-Fe2O3 acts as a glare on the red-emitting phosphor, significantly reducing the luminance of the red-emitting phosphor. A more preferable firing temperature range is 400 to 700°C. Baking time depends on filling amount,
Generally, 30 minutes to 5 hours is appropriate, although it varies depending on the firing temperature employed. As a result of this firing, α-FeO(0H) attached to the surface of the red-emitting phosphor becomes α-Fe2
O3, and the desired red-emitting phosphor with α-Fe2O3 red pigment particles is obtained.

By the manufacturing method described above, it is possible to obtain a pigmented phosphor in which α-Fe2O3 red pigment particles are extremely uniformly adhered to the surface of the red-emitting phosphor particles.
The pigmented phosphor obtained by the above production method plus an α-FeO(0H) aging step has a higher red color than the pigmented phosphor obtained by the above production method. It has a degree of coloring.

The ripening of α-FeO(0H) and the red-emitting phosphor obtained by supplying oxygen to a dispersion of chemically precipitated Fe(0H)2 with a red-emitting phosphor This is done by placing the phosphor mixture in an aqueous FesO4 solution containing metallic iron and supplying oxygen to the aqueous solution.

Oxygen is supplied by introducing air bubbles and oxygen bubbles into the aqueous solution as in the case of αFeO(0H) production, but air bubbles are generally used from an economic point of view. Further, it is preferable that the temperature of the aqueous solution is maintained at about 30 to 80° C. during oxygen supply. Iron powder, iron particles, iron scraps, etc. are used as the metal iron. This αFeO(0H) ripening reaction is expressed by the following formula. As is clear from the above reaction formula, by first supplying oxygen to the FesO4 aqueous solution, FesO4 is oxidized and hydrolyzed, resulting in α-FeO(
0H) and H2SO4 are generated, and this generated α-F
The eO(0H) causes the growth (ripening) of α-FeO(0H) fine particles (seed crystal 1) present in this aqueous solution together with the red light-emitting phosphor.

On the other hand, H2SO4 generated at the same time reacts with metal iron to replenish FesO4. This aging reaction of α-FeO(0H) is carried out as appropriate until the α-FeO(0H) fine particles grow to a desired size. Although it depends on the reaction rate, the particle size of the aged α-FeO(0H) obtained even if this aging reaction is carried out for quite a long time is significantly smaller than the particle size of the red-emitting phosphor. . After the aging reaction, the mixture of aged α-FeO(0H) and red-emitting phosphor is separated from the aqueous solution by a common method, washed with water,
Dry after dehydration. Aged α-F obtained in this way
Even in the mixture of eO(0H) and red-emitting phosphor, the aged α-FeO(0H) particles are considered to be attached to the surface of the red-emitting phosphor. This mixture is fired in the same manner as described above to obtain a red-emitting fluorophore with α-Fe2O3 red pigment particles. In general, α-F
The aging reaction of eO(0H) is the reaction between α-FeO(0H) and red-emitting fluorescein obtained by supplying oxygen to a dispersion of chemically precipitated Fe(0H)2 with red-emitting phosphor. This is carried out by once separating the mixture of bodies from the dispersion liquid and placing this mixture in a separately prepared aqueous FesO4 solution containing metallic iron, but if it is possible under the conditions,
The process may also be carried out in a dispersion by directly adding metal iron and FesO4 to the dispersion without separating the mixture of α-FeO(0H) and the red-emitting phosphor.

The pigmented phosphor obtained by the production method including the above α-FeO(0H) aging step is better than α-FeO(0H).
α-FeO (0H
), the surface of the red-emitting phosphor particles has a stable α-F particle size with a larger particle size and therefore a higher degree of red coloration.
This is thought to be due to the generation of e2sO4. The manufacturing method of the present invention is mainly applied to red-emitting phosphors used in cathode ray tubes for color television, but is not necessarily limited to this, and can be applied to generally commonly used red-emitting phosphors in general. Needless to say, it can also be applied to

As the red-emitting phosphor used in the production method of the present invention, for example, a manganese-activated zinc orthophosphate phosphor [Zn3(
PO4)2:Mn], manganese-activated magnesium silicate phosphor (MgSiO3:Mn), silver-activated zinc sulfide cadmium phosphor [(Zn.Cd)S:3Ag], europium-activated yttrium vanadate phosphor (YVO4:Eu)
, europium-activated yttrium oxysulfide phosphor (Y2O
2S:Eu), europium-activated yttrium oxide phosphor (Y2O3:Eu), etc.;
It is preferable to use a YVO4:Eu fluor, a Y2O2S:EU fluor, or a Y2O3:Eu fluor. The red light-emitting phosphor used in the manufacturing method of the present invention preferably has an average particle diameter of 3 to 15 μm. Furthermore, the α-
The amount of Fe2O3 varies somewhat depending on the type of red-emitting phosphor used, but in general, 0.01 to 5 parts by weight is appropriate for 100 parts by weight of the red-emitting phosphor. The manufacturing conditions of the manufacturing method of the present invention described above are set so that the required amount of α-Fe2O3 is generated on the surface of the red light-emitting phosphor particles. The pigmented phosphor obtained by the production method of the present invention described above has α-Fe2O3 red pigment particles extremely uniformly adhered to the surface of the red-emitting phosphor particles. The uniformity of the α-Fe2O3 red pigment particles is significantly superior to that of pigmented phosphors obtained by conventional methods.

FIG. 1 illustrates the reflection spectrum of the pigmented phosphor obtained by the production method of the present invention, and the curve a is α
-FeO(0H) The reflection spectrum of a pigmented phosphor produced by a production method that does not include the aging process, curve b is α
It is a reflection spectrum of a pigmented phosphor manufactured by a manufacturing method including a -FeO(0H) aging step.

The pigmented phosphors of curves a and b are both Y2O2S:EU phosphors to which approximately equal amounts of α-Fe2O3 are attached.

As is clear from curves a and b, it can be seen that the pigmented phosphor obtained by the production method of the present invention is colored red. This means that α-Fe2O is present on the surface of the phosphor particles.
3 is generated. Furthermore, as is clear from the comparison between curve c and curve b, the pigmented phosphor (
Curve b) does not include the α-FeO(0H) ripening step
It can be seen that the reflectance in the wavelength region shorter than the red region is lower and the degree of red coloring is higher than in the pigmented phosphor manufactured by the method (curve a). Figure 2 shows electron micrographs (x
3000), A is a pigmented phosphor obtained by the conventional method, and B is a pigmented phosphor obtained by the manufacturing method of the present invention. As shown in Figure 2-A, αFe2O3 red pigment particles (small particles in the photo) are preliminarily attached to the surface of red-emitting phosphor particles (large particles in the photo) using an adhesive. In the pigmented phosphor thus obtained, aggregation of pigment particles was observed, and the uniformity of the α-Fe2O3 red pigment particles on the surface of the red-emitting phosphor particles was not sufficient.

On the other hand, in the pigmented phosphor obtained by the manufacturing method of the present invention shown in FIG. 2-B, the α-Fe2O3 pigment particles as shown in FIG. 2-A naturally aggregate. In particular, hardly any particles resembling α-Fe2O3 red pigment were observed.

Considering that the pigmented phosphor obtained by the production method of the present invention exhibits good red coloring, this means that
This is believed to be because in the pigmented phosphor obtained by the production method of the present invention, fine α-Fe2O3 red pigment particles are uniformly adhered to the surface of the red-emitting phosphor particles in the form of a film. In addition, in the pigmented phosphor obtained by sufficiently aging α-FeO(0H), α-Fe2O3 red pigment particles were observed on the surface of the red-emitting phosphor particles. Fe2O3 red pigment particles are shown in Figure 2-A.
The particles are not as large as the α-Fe2O3 red pigment particles shown in FIG. As explained above, according to the present invention, α-F is present on the surface of red-emitting phosphor particles.
A pigmented phosphor in which e2O3 red pigment particles are extremely uniformly adhered without agglomeration can be obtained.

Conventionally, α-FeO(0H) is generated from Fe(0H)2, and this α-FeO(0H) is fired to form α-Fe2O3.
A method of producing red pigment particles and a method of ripening α-FeO(0H) in an aqueous FesO4 solution containing metallic iron in the production method have been known. However, when this method for producing α-Fe2O3 red pigment particles is carried out with a red-emitting phosphor interposed, α-
It has not been known in the past that Fe2O3 red pigment particles can be produced uniformly without agglomeration, and this was accomplished for the first time by the present inventors.

Next, the present invention will be explained with reference to Examples. Example 1 A mixed solution of 100 tons of water, 100f7 of Y2O2S:Eu phosphors with an average particle size of 7μ, and 0.87% of FeSO4.7H20 was prepared, and thoroughly stirred to disperse the Y2O2S:Eu phosphors and simultaneously disperse FeSO4.7H20. was dissolved.

To this FesO4 aqueous solution in which the Y2O2S:EU phosphor was dispersed, 50y of a 0.2% NaOH aqueous solution was added to Fe(
0H)2 was precipitated. Next, Y2 obtained in this way
The temperature of the dispersion of O,S:Eu phosphor and Fe(0H)2 was maintained at 30°C, and air bubbles were introduced at a flow rate of 21/min. 2
After a period of time, the supply of air bubbles was stopped, and after being allowed to stand, the supernatant liquid was removed by decantation, and the obtained α-FeO(0H) and Y2
The O2S:EU phosphor mixture was washed with water, dehydrated, and dried.

Next, α-FeO(0H) and Y2O2 obtained in this way
:The mixture of EU phosphor was filled into an alumina crucible and fired in air at a temperature of 600 DEG C. for 2 hours to obtain a Y2O2S:EU phosphor with α-Fe2O3 red pigment particles.

Analysis of the pigmented phosphor obtained by the above manufacturing method revealed that 0.3 parts by weight of α-Fe2O3 was attached to 100 parts by weight of the Y2O2S:EU phosphor.

In addition, the reflectance of this pigmented phosphor at 500 nm and 600 nm is 45% and 70%, respectively, and 5
The ratio of the reflectance at 600 nm to that at 00 nm was 1.56. Further, when this pigmented phosphor was observed under an electron microscope, it was found that the α-Fe2O3 red pigment particles were Y2O2S:E as shown in Figure 2-B.
It adhered extremely uniformly to the surface of the u phosphor particles. Example 2 Y2O2S:Eu with water 100V and average particle size of 7μ
Fluorescent material 100V and FeSO4・7H200.1y
A mixed solution was prepared and thoroughly stirred to disperse the Y2O2S:Eu phosphor and at the same time dissolve the FeSO4.7H20.

To this FeSO4 aqueous solution in which the Y2O2S:EU phosphor was dispersed, 25y of a 0.2% NaOH aqueous solution was added to
(0H)2 was precipitated. Next, Y obtained in this way
The temperature of the dispersion of 2O2S:EU phosphor and Fe(0H)2 was maintained at 30°C, and air bubbles were introduced at a flow rate of 21/min.
After 2 hours, stop introducing air bubbles, leave to stand, and remove the supernatant liquid by decantation to obtain α-FeO (0H).
and Y2O2S:EU fluorophore was washed with water.

Next, 100y of water and 0.2V(r)FeSO4・7H
α-FeO (0H
) and Y2O2S:Eu phosphor mixture and lowered the liquid temperature to 6.
While maintaining the temperature at 0° C. and stirring, air bubbles were introduced at a flow rate of 21/min.

After 6 hours, the air bubble supply was stopped and the iron particles were removed.

After standing, the supernatant liquid was removed by decantation to obtain aged α-FeO (0H) and Y2O2S:E.
The mixture of U phosphors was washed with water, dehydrated and dried. Next, the mixture of aged α-FeO(0H) and Y2O2S:Eu phosphor thus obtained was filled into an alumina crucible and fired in air at a temperature of 600°C for 3 hours to form α-F.
A Y2O2S:Eu phosphor with e2O3 red pigment particles was obtained. The pigmented phosphor obtained by the above manufacturing method had an analysis result of Y.

It was found that 0.3 parts by weight of α-Fe2O3 was attached to 100 parts by weight of the O2S:Eu phosphor. In addition, the reflectance of this pigmented phosphor at 500 nm and 600 nm is 36% and 72%, respectively, and 500 nm
The ratio of reflectance at 600 nm to reflectance at nm was 2.00. Further, when this pigmented phosphor was observed under an electron microscope, it was found that the α-Fe2O3 red pigment particles were extremely uniformly adhered to the surface of the Y2O2S:Eu phosphor particles, as shown in FIG. 2-B. The pigmented phosphor manufactured by the manufacturing method of the above two examples,
A pigmented phosphor manufactured by a conventional manufacturing method (a method of attaching a red pigment to the surface of a Y2O2S:Eu phosphor using a binder, as shown in JP-A-53-14177) Conventional Example 1 and Conventional Example 2 (Conventional Example 2 is obtained by aging Conventional Example 1 in the manner of Example 2) Comparison data is shown in the following table. In this comparison, the integrated reflectances of both were made the same and other characteristics were compared.

As is clear from the above comparison table, when comparing the method of the present invention and the conventional method, the integrated reflectance (that is, the sum of the reflectances at all wavelengths, in other words, the spectroscopically averaged reflection (I) Requires less pigment (゛) Higher reflectance at 620 nm (object color is redder and better) (Ili ) High brightness (0V)) It has the characteristic advantage of a high ratio of 600 nm reflectance/500 nm reflectance (the red side has a higher reflectance), confirming that the method of the present invention is superior. can.

[Brief explanation of drawings]

FIG. 1 illustrates the reflection spectrum of the pigmented phosphor obtained by the production method of the present invention, and the curve a is α
-Reflectance spectrum of a pigmented phosphor produced by a production method that does not include the FeO(0H) aging process, curve b is α
It is a reflection spectrum of a pigmented phosphor manufactured by a manufacturing method including a -FeO(0H) ripening step.

Claims (1)

[Claims] 1. Infrared-emitting phosphor and chemically precipitated iron(II) hydroxide
Oxygen is supplied to the dispersion of [Fe(OH)_2] to convert iron (II) hydroxide [Fe(OH)_2] into α-iron oxide hydroxide (I
II) [α-FeO(OH)], and then a mixture of α-iron hydroxide hydroxide (III) [α-FeO(OH)] and a red color-forming phosphor is separated from this dispersion. The mixture was fired at a temperature of 250 to 750°C in an oxidizing atmosphere to remove α-iron oxide hydroxide (
III) [α-FeO(OH)]
2O_3) A method for producing a pigmented phosphor. 2. The method for producing a pigmented phosphor according to claim 1, wherein the firing temperature is 400 to 700°C. 3. The method according to claim 1 or 2, wherein the iron oxide (α-Fe_2O_3) is produced in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of the red light-emitting phosphor. A method for producing a pigmented phosphor. 4. The method for producing a pigmented phosphor according to any one of claims 1 to 3, wherein the red-emitting phosphor has an average particle diameter of 3 to 15 μm. 5. The pigmented fluorescent material according to any one of claims 1 to 4, wherein the red-emitting phosphor is a europium-activated yttrium oxysulfide phosphor (Y_2O_2S:Eu). Method of manufacturing light bodies. 6. The pigmented phosphor according to any one of claims 1 to 4, wherein the red-emitting phosphor is a europium-activated yttrium oxide phosphor (Y_2O_3:Eu). How the body is manufactured. 7. The pigmented fluorescent material according to any one of claims 1 to 4, wherein the red-emitting phosphor is a europium-activated yttrium vanadate phosphor (YVO_4:Eu). Method of manufacturing light bodies. 8. Red-emitting phosphor and chemically precipitated iron(II) hydroxide
Oxygen is supplied to the dispersion of [Fe(OH)_2] to convert iron (II) hydroxide [Fe(OH)_2] into α-iron oxide hydroxide (I
II) [α-FeO(OH)] and then separate a mixture of α-iron hydroxide hydroxide [α-FeO(OH)] and red-emitting phosphor from this dispersion. A mixture of iron(III) hydroxide oxide [α-FeO(OH)] and a red-emitting phosphor is placed in an aqueous solution of iron(II) sulfate (FeSO_4) containing metallic iron, and oxygen is supplied to this aqueous solution. Tsuteα
- Aging iron(III) hydroxide oxide [α-FeO(OH)], and then converting this aqueous solution into aged iron(III) oxide hydroxide [α-FeO(OH)] and red-emitting fluorescence. This aged mixture of α-iron(III) hydroxide hydroxide [α-FeO(OH)] and red-emitting phosphor was heated in an oxidizing atmosphere at a temperature of 250 to 750°C. A pigmented product characterized in that aged α-oxidized iron hydroxide (III) [α-FeO(OH)] attached to the surface of red-emitting phosphor particles by firing with red iron (α-Fe_2O_3) Method for manufacturing phosphors. 9. The method for producing a pigmented phosphor according to claim 8, wherein the firing temperature is 400 to 700°C. 10. The method according to claim 8 or 9, wherein the iron oxide (α-Fe_2O_3) is produced in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of the red light-emitting phosphor. A method for producing a pigmented phosphor. 11 The average particle diameter of the red light-emitting phosphor is 3 to 15 μm.
Claims 8 to 1 are characterized in that:
A method for producing a pigmented phosphor according to any one of item 0. 12. The pigmented fluorescent material according to any one of claims 8 to 11, wherein the red-emitting phosphor is a europium-activated yttrium oxysulfide phosphor (Y_2O_2S:Eu). Method of manufacturing light bodies. 13. The pigmented phosphor according to any one of claims 8 to 11, wherein the red-emitting phosphor is a europium-activated yttrium oxide phosphor (Y_2O_3:Eu). How the body is manufactured. 14. The pigment phosphor according to any one of claims 8 to 11, wherein the red-emitting phosphor is a europium-activated yttrium vanadate phosphor (YVO_4:Eu). How the body is manufactured.