JP2010180380A - Glass-coated phosphorescent light emitter particle and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing phosphorescent light emitter particles with excellent water resistance and with uniform particle size and phosphor distribution. <P>SOLUTION: On a temporary retaining member, (1) a mask having periodically arranged holes is mounted, and multiple mixture layers (A) are formed by screen printing a mixture of glass fine particles and a resin adhesive agent; (2) before the resin adhesive agent cures, a mixture of phosphor particles and glass particles are spread on the mixture layers (A) to form a phosphor layer (B) thereon; (3) the mask used in step (1) is aligned and mounted on the phosphor layer (B) and a mixture layer (A) is formed by screen printing a mixture of glass fine particles and a resin adhesive agent; (4) by repeating step (2) and step (3) as needed, a granular laminate is formed with three layers or five or more layers where the mixture layer (A) and the phosphor layer (B) are stacked alternately; and (5) glass-coated phosphorescent light emitter particles are manufactured by firing the granular laminate. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to phosphorescent phosphor particles used for, for example, signs for evacuation guidance, guidance lines, road white lines, or decorative patterns, and a method for producing the same, and in particular, phosphorescent luminescence with excellent water resistance and low luminance unevenness. The present invention relates to body particles and a method for producing the same.

In recent years, phosphorescent phosphors that are excited by ultraviolet rays or the like and have long afterglow observed, for example, MAl ₂ O ₄ (M is calcium, strontium, or barium) are used as mother crystals and activated by lanthanoids such as europium. A luminous phosphor (Patent Document 1) has been developed.

  Such phosphorescent illuminants are used for evacuation guidance signs, guide lines, etc., but the phosphorescent illuminator alone is easily hydrolyzed, so it is durable to use outdoors that touch rainwater etc. There were drawbacks in terms of Therefore, a method of pulverizing a phosphorescent phosphor and a ceramic base material after mixing and firing (Patent Documents 2 and 3), and forming a mixed member layer in which phosphorescent phosphor particles and glass particles are mixed on a temporary holding member. In addition, after the temporary holding member is peeled off, it is possible to use the phosphorescent phosphor particles with improved water resistance by covering the phosphorescent phosphor by a method such as firing-grinding-refiring (Patent Document 4). Proposed.

Japanese Patent No. 2543825 Japanese Patent No. 3580652 Japanese Patent No. 3580653 JP 2007-112585 A

  However, in the manufacturing method of the phosphorescent phosphor particles, the phosphorescent phosphor is made of a glass material or the like because the phosphorescent phosphor and the ceramic base material or the glass material are mixed and fired and then pulverized to form phosphorescent phosphor particles. However, the problem of water resistance was not sufficiently solved. In addition, the phosphor particles are not mixed in a uniform amount in the phosphor particles here, and there is a problem that unevenness occurs in emission luminance for each particle. In addition, since the particles are formed by pulverization, there is a problem that the sizes of the particles are uneven, that is, the particle size distribution is large and the luminance unevenness is similarly generated. Therefore, the yield was low and the production cost was problematic.

  The present invention has been made in view of the above-mentioned problems, and the purpose thereof is a phosphorescent phosphor particle in which substantially all phosphorescent phosphor particles are coated with glass and water resistance is significantly improved, and An object of the present invention is to obtain glass-coated phosphorescent phosphor particles having uniform phosphor particles and containing the same amount of phosphor in each particle almost uniformly and to provide a method for producing the same.

  In the present invention, a plurality of glass fine particle and resin adhesive mixture layers are formed on a temporary holding member using screen printing using a mask in which a large number of holes having the same diameter are formed. A phosphor particle layer containing body particles and glass particles is formed, and a mixture layer of glass fine particles and a resin adhesive is further formed thereon using the mask, and if necessary, a phosphor particle layer and By repeating the formation of the mixture layer and further laminating, and then firing the particulate laminate, the particle size is uniform, and the phosphor is blended in a uniform amount in each particle, and is substantially phosphorescent with glass. The above-mentioned problems have been solved by producing phosphorescent phosphor particles coated with phosphorescent particles.

That is, the first gist of the present invention is as follows.
(1) A mask in which a large number of holes having the same diameter are formed is placed, and a plurality of mixture layers (A) are formed on a temporary holding member by screen printing a mixture of glass fine particles and a resin adhesive,
(2) Before the mixture layer (A) is solidified, the phosphor particles and glass particles are arranged on the mixture layer (A), and the phosphor layer (B) is placed on the mixture layer (A). )
(3) The mask plate used in the step (1) and the temporary holding member are aligned and placed on the phosphor layer (B) by screen printing a mixture of glass fine particles and a resin adhesive. A),
(4) A granular laminate in which the mixture layer (A) and the phosphor layer (B) are alternately laminated in three layers or five or more layers by repeating the steps (2) and (3) as necessary. Many points are formed on the temporary holding member,
(5) The present invention resides in a method for producing glass-coated luminous phosphor particles, wherein the granular laminate is fired without peeling the temporary holding member or without peeling the temporary holding member.

  The glass fine particles used for the mixture layer (A) may be any glass particles that can be mixed with a resin adhesive and screen-printed, but have a low softening temperature so that the phosphor can be easily coated with glass. A glass frit having a particle size of 5 to 30 μm is particularly preferable. The resin adhesive used for the mixture layer (A) may be any as long as screen printing is possible.

  The glass particles and the phosphor particles used in the phosphor layer (B) preferably have the same size as each other. Usually, the size of the glass particles is 0.5 that of the phosphor particles. Glass particles and phosphor particles are selected so as to be in the range of ˜2 times. Since the phosphor layer (B) is formed by adhering to the adhesive in the mixture layer (A) before the mixture layer (A) is solidified, it is formed into a layer. The particle diameter of the phosphor particles is the thickness of the phosphor layer (B). For this reason, the magnitude | size of the phosphor particle and the glass particle is suitably selected according to the thickness of the desired phosphor layer (B).

  The weight ratio of the glass particles and the phosphor particles in the phosphor layer (B) is preferably in the range of 7: 3 to 9: 1. If the amount of glass particles is small, the phosphor particles after firing are not preferable because the phosphor particles are not completely covered with glass. On the other hand, if the relative amount of the phosphor particles is too small, the luminance of the phosphor particles is decreased, which is not preferable.

  Whether the laminate of the mixture layer (A) and the phosphor layer (B) is 3 layers or 5 layers or more is determined according to the hole diameter of the mask. In order to make the obtained luminous phosphor particles closer to a spherical shape, the resin adhesive in the mixture layer is removed by firing and shrinks in the thickness direction of the particulate laminate, so the total of the particulate laminate before firing The thickness is 1.5 to 3 times, preferably around 2 times the diameter of the mask hole. The thickness of the mixture layer (A) is approximately the same as the thickness of the mask used for screen printing, and the thickness of the phosphor layer (B) is approximately the same as the particle size of the phosphor particles or glass particles. If the hole diameter and thickness of the mask to be masked and the particle diameter of the luminous phosphor particles are determined, the required number of laminations is determined.

  Firing of the temporary holding member on which the granular laminate is placed is heated at 300 to 500 ° C. for 1 hour or longer in a firing furnace, and is removed by baking so as not to carbonize the resin adhesive in the granular laminate. The glass particles are fired at 600 to 800 ° C. to fuse the glass particles to form luminous phosphor particles that are substantially entirely covered with glass.

  At the time of the firing, when the granular laminate is formed on the resin thin layer with an interval, and the granular laminate is fired while adhering to the resin thin layer, the granular laminates can be prevented from sticking to each other. Therefore, in the screen printing mask, it is preferable that the distance between the formed holes is equal to or larger than the diameter of the holes. However, if the distance is too large, the number of points of the mixture layer (A) formed by one screen printing is obtained. This reduces production efficiency. Further, it is preferable in terms of production efficiency that the holes are arranged periodically.

By forming a water-soluble surface on the base material and further screen-printing on a temporary holding member on which a water-insoluble resin thin layer is formed, and immersing the temporary holding member in water for a short time, the granular laminate becomes a resin thin layer. Can be easily produced.

  The second gist of the present invention is characterized in that the initial luminance after the phosphorescent phosphor particles are immersed in water at room temperature for 48 hours is 85% or more of the initial luminance before being immersed in water. The glass-coated luminous phosphor particles are

  According to the present invention, glass-coated phosphorescent phosphor particles having a uniform particle size and a uniform distribution of phosphorescent particles on each particle and excellent in water resistance can be easily produced. Moreover, the luminous phosphor particles having a desired particle diameter can be obtained by changing the hole diameter of the mask. Moreover, since the luminous phosphor particles of the present invention have a uniform particle size, sieving is not required, and the yield is improved.

Explanatory drawing of the manufacturing method of this invention

Hereinafter, although embodiment of this invention is described using drawing, this invention is not limited to these embodiment, unless the summary is exceeded.
FIG. 1 is an explanatory diagram of an embodiment of the manufacturing method of the present invention.
As shown in FIG. 1, a water-soluble surface 2 (for example, dextrin) is formed on the surface of a substrate 1 (for example, cardboard) of a temporary holding member, and a resin thin layer 3 (for example, an acrylic resin adhesive is applied thereon). A hardened layer is prepared (I in FIG. 1), and a mask 4 in which holes of a desired size (for example, a diameter of 1000 μm) are periodically vacated is formed on the resin thin layer 3. Then, the mixture layer (A) is formed by screen-printing the mixture composed of the glass fine particles and the resin adhesive (II in FIG. 1).

The distance between the mask holes and the holes is preferably larger than the diameter of the mask holes. For example, when the diameter of the mask hole is 500 μm, the distance between the holes is preferably 500 μm or more, more preferably 1 to 1.5 mm. The thickness of the mask is not particularly limited, but is preferably about half the diameter of the mask hole. For example, when the hole diameter is 500 μm, the thickness of the mask is preferably about 200 to 300 μm. The layer thickness of the mixture layer (A) is approximately the same as the plate thickness of the mask.
The shape of the mask hole is not limited to a circle, but may be an ellipse, a polygon such as a rectangle or a hexagon, but if the hole shape is extremely distorted, the resulting phosphorescent phosphor glass particles become distorted. This is not preferable. When the shape of the mask hole is other than a circle, the “hole diameter” in this specification is the diameter of a circle inscribed in the hole.

  The material of the glass fine particles may be any material as long as it is transparent to the excitation light and light emission of the phosphor. However, a material having a low softening temperature is preferable in order to completely cover the phosphor with glass after firing. The particle size of the glass fine particles may be any particle size as long as it can be mixed with a resin adhesive and screen printed. Examples of preferable glass fine particles include glass frit having a particle size of 5 to 30 μm.

The resin adhesive is not particularly limited as long as it can be adjusted to a viscosity capable of screen printing, and examples thereof include an adhesive made of an acrylic resin and a solvent.
The mixing ratio of the glass fine particles and the resin adhesive is not particularly limited, but is preferably in the range of 3: 1 to 1: 3 by weight.

  Then, before the mixture layer (A) is solidified, the phosphor particles (B) are formed by arranging the phosphor particles and glass particles on the mixture layer (A) (III in FIG. 1). The phosphor layer (B) is formed in the manner of drawing a sand picture. That is, the phosphorescent material or glass particles placed on the mixture layer (A) are bonded onto the mixture layer (A) by the resin adhesive in the mixture layer (A), thereby forming the phosphor layer (B). Since the phosphor particles or glass particles that have fallen into the gaps between the mixture layers (A) are not adhered, they can be removed by a method such as shaking the temporary holding member.

  Phosphors are known phosphors such as oxide phosphors such as strontium aluminate activated by lanthanoids such as europium, and sulfide phosphors such as phosphors doped with barium calcium sulfide. Either is acceptable.

  The particle diameter of the phosphor particles may be smaller than the diameter of the mask hole, and the average particle diameter is preferably about half of the diameter of the mask hole. For example, when the mask hole has a diameter of 500 μm, phosphor particles having a maximum particle size of 500 μm or less and an average particle size of around 250 μm are preferable.

  The particle size of the glass particles that form the phosphor layer together with the phosphor particles is preferably the same as the particle size of the phosphor particles. The material of the glass particles may be any material as long as it is transparent to the excitation light and light emission of the phosphor, and examples thereof include borosilicate glass.

  The mixing ratio of the phosphor particles and the glass particles is preferably in the range of 9: 1 to 7: 3 in terms of the weight ratio of glass: phosphor. If the amount of glass particles is small, the phosphor-coated phosphor particles after firing are not preferable because the phosphor particles are not completely covered with glass. If the amount of the phosphor particles is too small, the luminance of the glass-coated phosphor particles is reduced, which is not preferable.

  A mixture layer (A) is further formed on the phosphor layer (B) by screen printing. At this time, the mixture layer (A) can be formed on the phosphor layer (B) by placing the mask plate used in the previous step and the temporary holding member in alignment (IV in FIG. 1). .

  Although FIG. 1 shows an example in which the granular laminated body has three layers, if necessary, the phosphor layer and the mixture layer may be alternately laminated to form five or more layers. The number of layers of the granular laminate is preferably set so that the total thickness of the granular laminate before firing is 1 to 3 times the diameter of the mask hole. Since the thickness of the mixture layer (A) is almost the same as the mask plate thickness and the thickness of the phosphor layer (B) is about the same as the average particle size of the phosphor particles, the approximate total of the granular laminates The thickness can be easily estimated and the preferred number of layers can be estimated. For example, when the mask plate thickness is 200 μm and the average particle diameter of the phosphorescent material particles is 250 μm, the total thickness of the three layers is about 650 μm, the five layers are about 1100 μm, and the seven layers are about 1550 μm. When the mask hole diameter is 500 μm, the total thickness of the laminate before firing is preferably about 500 to 1500 μm. Therefore, the mixture layer (A) and the phosphor layer (B) have a three-layer or five-layer structure. Is the best. In order to manufacture large phosphorescent phosphor glass particles, if the mask hole is enlarged, the mask thickness should be increased or the particle size of the phosphor particles should be increased so that the number of laminations does not become excessive. It is preferable to enlarge it.

After the resin adhesive of the granular laminate is solidified, it is immersed in water for several seconds to dissolve the water-soluble surface 2, and the resin thin layer 3 on which the granular laminate is placed is peeled from the substrate 1 of the temporary holding member, and the resin The granular laminate is fired while being placed on the thin layer 3. Baking is carried out at 300 to 500 ° C. for 1 hour or longer, and the resin adhesive in the resin thin layer and the mixture layer (A) is incinerated and removed so that the resin is not carbonized. In this step, the temperature may be maintained at any temperature of 300 to 500 ° C, or may be slowly raised to be in the range of 300 to 500 ° C for 1 hour or more.
The glass particles are then fused together by maintaining at 600-800 ° C. for 5-30 minutes.

  Since the glass-coated phosphor particles produced by the above production method have a uniform particle size and a uniform phosphor content in each particle, luminance unevenness is reduced. In addition, since the phosphor is almost completely covered with glass, it has excellent water resistance, and even when the phosphorescent phosphor particles are immersed in water, there is little decrease in luminance. % Or more of the initial luminance can be maintained.

EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited to an Example.
[Example 1]
A dextrin layer (water-soluble layer) is formed on the surface of the cardboard (temporary holding member base material), and a resin adhesive (screen printing oil manufactured by Ferro Japan) is screen-printed with a solid plate to obtain a temporary holding member. .
On this temporary holding member, a metal mask having a plate thickness of about 200 μm in which holes having a diameter of 1000 μm are periodically vacated at intervals of about 1000 μm is placed, and 10 parts by weight of a glass frit having a particle size of 5 to 10 μm (manufactured by Nippon Frit) A mixture layer (A) having a thickness of about 200 μm was formed by screen-printing a mixture obtained by mixing 8 parts by weight of the resin adhesive.

Next, before the acrylic resin adhesive solidifies, 2 parts by weight of phosphor particles having an average particle diameter of 250 μm (trade name G300L--250N manufactured by Nemoto Special Chemical Co., Ltd.) and borosilicate glass particles having an average particle diameter of 250 μm (Potters) 8 parts by weight of mixed particles (made by Ballotin Co., Ltd.) were placed on the mixture layer (A) to form a phosphorescent material layer (B).
Thereafter, the mask plate and the temporary holding member used in the previous step are aligned and placed, and the mixture layer (A) is formed on the phosphorescent material layer (B) by screen printing. A granular laminate having a layer structure was formed.
After the adhesive was dried and solidified, the temporary holding member was immersed in water for several seconds to dissolve the dextrin layer, and a granular laminate was periodically arranged on the resin film.

The obtained granular laminate was baked in a baking furnace together with the resin film. Firing was performed by slowly raising the temperature, taking 1 hour or more at 300 to 500 ° C., then maintaining at about 700 ° C. for about 15 minutes, and then slowly cooling to room temperature to obtain glass-coated phosphorescent phosphor particles.
The obtained glass-coated luminous phosphor particles were approximately spherical. When sieving using a JIS Z 8801 standard sieve, as shown in Table 1, 97% or more by weight ratio was in the range of 1000 μm to 1400 μm, and the particle size was uniform.

The obtained glass-coated luminous phosphor particles were immersed in water at room temperature for 48 hours, and the initial luminance before and after being immersed in water was measured. The initial luminance before immersion in water was 66 mcd / m ² , 48 hours. The initial luminance after being immersed in water was 60 mcd / m ² , and the initial luminance of about 91% before being immersed in water was maintained. The initial luminance is the luminance of the luminous phosphor particles when the phosphor particles are irradiated with a 200 Lux D65 fluorescent lamp for 20 minutes and then moved to a dark place.

[Comparative Example 1]
The external appearance of the obtained glass-coated phosphorescent phosphor particles was observed in the same manner as in Example 1 except that the mixing ratio of the phosphor particles and the borosilicate glass particles for forming the phosphor layer (B) was changed. The results are shown in Table 1.

  From this result, it is understood that the mixing ratio of the glass and the phosphor in the phosphor layer is preferably 9: 1 to 7: 3 by weight.

[Comparative Example 2]
Glass-coated luminous phosphor particles were produced in the same manner as described in JP-A No. 2007-112585. That is, on a temporary holding member having a dextrin layer formed on the surface of cardboard, phosphor particles (60 parts by weight) having an average particle diameter of about 25 μm, glass frit (100 parts by weight) having a particle diameter of 6 to 8 μm, and squeegee oil ( 80 parts by weight of the mixture is screen-printed using a solid plate to form a 150 μm thick glass / phosphor mixture layer, the temporary holding member is peeled off, fired at about 800 ° C., crushed and refired. Thus, glass-coated luminous phosphor particles were obtained.
The particle size distribution of the obtained luminous phosphor particles was as shown in Table 3, and the particle sizes were uneven. Moreover, the glass particle which does not contain a phosphor is scattered.

Moreover, when the obtained luminous phosphor particles were immersed in water for 48 hours and the luminance before and after immersion was measured, the initial luminance before immersion in water was 61 mcd / m ² , and the initial luminance after immersion was At 50 mcd / m ² , there was only about 82% of the brightness before immersion in water.

  According to the present invention, phosphorescent phosphor particles having excellent water resistance and a uniform particle size and phosphorescent substance distribution can be obtained, and phosphorescent light can be stored not only indoors but also on outdoor signs, guide lines, road white lines, etc. The body can be used.

1: base material of temporary holding member 2: water-soluble surface 3: water-insoluble resin thin layer 4: mask A: mixture layer B: phosphorescent material layer

Claims (9)

(1) A mask in which a large number of holes having the same diameter are formed is placed, and a plurality of mixture layers (A) are formed on a temporary holding member by screen printing a mixture of glass fine particles and a resin adhesive,
(2) Before the mixture layer (A) is solidified, a mixture of phosphor particles and glass particles is placed on the mixture layer (A), and the phosphor layer (B) is placed on the mixture layer (A). Form
(3) The mask plate used in the step (1) and the temporary holding member are aligned and placed on the phosphor layer (B) by screen printing a mixture of glass fine particles and a resin adhesive. A),
(4) A granular laminate in which the mixture layer (A) and the phosphor layer (B) are alternately laminated in three layers or five or more layers by repeating the steps (2) and (3) as necessary. Many points are formed on the temporary holding member,
(5) The method for producing glass-coated luminous phosphor particles, wherein the granular laminate is fired without peeling the temporary holding member or without peeling the temporary holding member.   2. The glass-coated luminous phosphor particles according to claim 1, wherein the granular laminate is fired at 300 to 500 ° C. for 1 hour or more and then calcined at 600 to 800 ° C. for 5 to 30 minutes. Production method.   The glass-coated phosphorescent material according to claim 1 or 2, wherein the average particle size of the glass particles used in the phosphor layer (B) is 0.5 to 2 times the average particle size of the phosphor particles. For producing fluorescent luminescent particles.   4. The ratio of glass particles to phosphor particles used in the phosphor layer (B) is 7: 3 to 9: 1 in a weight ratio. 5. A method for producing glass-coated luminous phosphor particles.   The thickness before firing of the granular laminate (the total thickness of the mixture layer (A) and the phosphor layer (B)) is 1.5 to 3 times the diameter of the hole in the mask. The method for producing glass-coated luminous phosphor particles according to any one of claims 1 to 4.   The temporary holding member is formed by forming a water-soluble surface on a base material, and forming a water-insoluble resin thin layer on the water-soluble surface, and screen printing is performed on the water-insoluble resin thin layer. The manufacturing method of the glass covering luminous phosphor particle in any one of Claims 1 thru | or 5.   Before firing the granular laminate, the temporary holding member is immersed in water to dissolve the water-soluble surface, and the granular laminate is fired in a state of being disposed on the water-insoluble resin thin layer. 6. A method for producing glass-coated luminous phosphor particles according to 6. Excellent in nature   8. The glass-coated luminous phosphor according to claim 1, wherein the holes of the mask for screen-printing the mixture layer (A) are periodically arranged at intervals equal to or larger than the diameter of the holes. Particle production method.   Glass-coated phosphorescent phosphor particles, wherein the initial luminance after the phosphorescent phosphor particles are immersed in water at room temperature for 48 hours is 85% or more of the initial luminance before being immersed in water.

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