JP2000011887A - Phosphor paste and manufacture of plasma display panel substrate by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the dispersibility of phosphor powder and to uniformly and stably apply the paste to the bottom and side part of a bulkhead by including the phosphor powder, a binder resin and a solvent as main components, and setting pH within a specified range. SOLUTION: The pH of a phosphor paste is set to 7.5-11. Therefore, a material showing alkaline property is added. As this material, an organic compound removable in drying and baking processes is preferably used and, further, it is preferably liquefied at 25 deg.C and has a boiling point of 150-300 deg.C under normal pressure. Specific examples of such an organic compound include 3-(2-ethylhexyl) propylamine. The phosphor paste preferably consists of 30-60 wt.% of phosphor powder, 5-20 wt.% of a binder resin, and the remainder mainly consisting of an organic compound, an organic solvent and the like. The weight ratio of the phosphor powder to the binder resin is preferably 6:1 to 2:1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phosphor paste for a plasma display panel (hereinafter referred to as "PDP").
The present invention relates to a phosphor paste for producing a DP substrate and a method for producing a PDP substrate using the same.

[0002]

2. Description of the Related Art PDPs have permeated OA equipment and public information display devices because they can display at a higher speed than liquid crystal displays and can be easily made larger. Further, progress in the field of high-definition television is highly expected.

With the expansion of such applications, attention has been paid to color PDPs having a large number of fine display cells.
The PDP generates a plasma discharge between an anode and a cathode facing each other in a discharge space provided between a front glass substrate and a rear glass substrate, and emits ultraviolet light generated from a gas sealed in the discharge space. The display is performed by hitting a phosphor provided in the discharge space.
In this case, a partition (also referred to as a barrier or a rib) is provided to keep the spread of the discharge in a certain area and to perform display in a specified cell and to secure a uniform discharge space.

These partition walls are often formed in a stripe shape, and their sizes (line width, height, pitch) are P
Depends on DP performance. In order to increase the definition of PDP,
In other words, in order to increase the number of pixels at a certain screen size,
It is necessary to reduce the size of one pixel. In this case, it is necessary to reduce the pitch between the partition walls. However, when the pitch is reduced, the discharge space is reduced, and the luminance is reduced because the phosphor application area is reduced. Specifically, a 42-inch high-definition television (1920 × 10
OA monitor (35 pixels) or 23 inch (XGA: 10
In order to realize (24 × 768 pixels), the pixel size needs to be 450 μm, and the partition walls for each color need to be formed at a pitch of 150 μm. In this case, if the line width of the partition is large, a sufficient discharge space cannot be secured, and the application area of the phosphor becomes small, so that it becomes difficult to improve the luminance. For this reason, the partition wall for high definition has a stripe shape and a size of 15 to 50 μm.
m, height 80-150 μm, pitch 100-250 μm
Is preferably used.

[0005] The partition is usually formed on the rear glass substrate,
Phosphor layers for performing red (R), green (G) and blue (B) color display are further formed between cells formed by the partition walls. The formation of these phosphor layers has been conventionally performed by a screen printing method using a phosphor paste. That is, a process of applying a red light-emitting phosphor paste, a green light-emitting phosphor paste, and a blue light-emitting phosphor paste to between the partitions (cells) using a screen printing plate and drying the same is sequentially repeated.

[0006] This phosphor coating technique is an elemental technique that affects the quality of the PDP, and the phosphor paste is devised so as to be applied not only to the bottom of the cell but also to the side face of the partition for higher brightness. Have been. In addition, stable uniform application is required to eliminate screen unevenness. For this reason, in the screen printing method, the positional accuracy with respect to the partition walls, the rheology of the paste, and the like are important.

However, the screen printing plate is not in contact with the flat surface, but the phosphor paste is transferred while being supported by the top of the partition, so that the dirt on the back surface of the screen printing plate adheres to the top of the partition. Besides that happens,
It is difficult to maintain positional accuracy because the metal mesh tends to be warped or twisted. This tendency becomes severe as the size increases, and it is very difficult to produce a large-size, high-definition plasma display by a screen printing method.

In order to improve the screen printing technique, Japanese Patent Application Laid-Open No. 6-5205 discloses a method using a sandblasting technique.
No. 5 proposes a method of screen printing after applying a crosslinking agent. However, these were within the scope of the screen printing method and were not sufficiently improved.

In addition, there is a method using a photolithography technique as a method for realizing high-precision pattern coating. In this case, in order to form phosphor layers of red, green, and blue, each color is formed. There is a problem that the steps become complicated, for example, the steps of coating-exposure-development are repeated.

Therefore, as a method of applying the phosphor paste into the cells formed by the partition walls, a method of ejecting the phosphor paste from the tip of an ink jet nozzle to form a phosphor layer has been proposed. However, the viscosity of the phosphor paste must be 0.2 poise or less, and the amount of the phosphor powder in the paste cannot be increased, so that the thickness of the formed phosphor layer is reduced. Also,
Since the diameter of the ink jet nozzle is small, there is also a problem that the phosphor powder is clogged.

Further, the phosphor paste is obtained by dissolving and dispersing a phosphor powder and a binder resin component in an appropriate solvent (such as an organic solvent), and is neutral (pH 6.5 to 7.0).
4). Such a phosphor paste,
After dissolving and dispersing, it is good for one or two days, but if left for about three days or more, the phosphor powder will sediment and stick to the bottom of the container, and will not be redispersed by stirring. For this reason, it is necessary to use the device again with the disperser, which is inefficient. Further, the phosphor layer formed by applying the phosphor paste whose dispersion state has been reduced lacks uniformity in thickness even if it does not settle to the bottom of the container. Further, when the phosphor paste is transferred by a pipe or the like, there is a drawback that the phosphor paste easily adheres and deposits in the pipe, and when the phosphor paste is discharged from a discharge hole or the like, it is easily clogged depending on the structure of the discharge hole.

[0012]

SUMMARY OF THE INVENTION It is an object of the present invention to improve the above-mentioned drawbacks of the prior art, to provide a phosphor powder with good dispersibility, and to apply a phosphor paste uniformly and stably to the bottom and side surfaces of the partition walls. It is a first object of the present invention to provide a phosphor paste capable of forming a phosphor layer having an appropriate shape in a cell and producing a PDP substrate having high definition and high luminance. A second object of the present invention is to provide a method for manufacturing a PDP substrate using the phosphor paste.

[0013]

SUMMARY OF THE INVENTION The first object of the present invention is to provide a fluorescent material comprising a phosphor powder, a binder resin and a solvent as main components and having a pH of 7.5 to 11. Can be achieved by body paste.

A second object of the present invention is to provide a phosphor powder which emits any one of red, green and blue colors, a binder resin and a solvent as main components and a pH of 7.5 to 11. Manufacturing a phosphor screen by discharging a kind of phosphor paste from a die having a discharge hole, applying the paste in stripes between partition walls on a glass substrate, and then baking to form a phosphor screen. Can be achieved by law.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a phosphor paste contains at least a phosphor powder and a binder resin component and is dissolved and dispersed in an appropriate solvent (such as an organic solvent). 0.5 to 11.

By making the base powder weakly alkaline, the phosphor powder is unlikely to settle during storage or the like, and even if settled, it is redispersed by stirring, and the handling property is greatly improved. Further, clogging of a pipe, a discharge hole, and the like can be suppressed. In addition, since the paste is weakly alkaline, the paste is less corrosive and can be easily handled.

In the case of a strong alkali having a pH of more than 11, the paste is so corrosive that the paste cannot be easily handled. On the other hand, if the pH is less than 7.5, the redispersibility of the precipitated phosphor powder becomes poor, and the object of the present invention cannot be achieved.

The method for adjusting the pH of the phosphor paste to 7.5 to 11 includes adding a substance exhibiting alkalinity. Such a substance includes an organic compound which can be removed in a drying step or a baking step. Preferred are mentioned. For this purpose, it is preferable that the liquid be a liquid at 25 ° C. If it is liquid at 25 ° C., it can be easily dissolved at the time of preparing the paste, and it can be expected that good results can be obtained for the dispersibility of the powder. Further, a substance having a pH of 7.5 to 12 of the substance itself is preferable in view of the effect of adjusting the pH of the paste, the ease of handling, the low corrosion property, and the like.

The pH of the phosphor paste or organic compound
Is a value measured using a commercially available pH test paper (for example, DUOTEST two-band pH test paper).

Further, the fact that the boiling point of the organic compound at normal pressure is 150 to 300 ° C. is 80 to 100 ° C. (the temperature at which the binder resin does not melt and does not affect the shape of the phosphor layer formed by coating between the partition walls). ) Is preferable because it can be removed in a drying step for about 20 to 60 minutes. If the boiling point is lower than 150 ° C., it tends to volatilize during paste production such as kneading, and the viscosity is not easily stabilized. On the other hand, when the temperature exceeds 300 ° C., drying becomes insufficient, and cracks may occur in the phosphor layer after the drying step.

As such an organic compound, 3- (2-
Amine compounds such as ethylhexyloxy) propylamine, 3- (dibutylamino) propylamine, di-2-ethylhexylamine, 3- (diethylamino) propylamine, and 3-ethoxypropylamine can be preferably used.

The addition of the organic compound exhibiting alkalinity to the phosphor powder in an amount of 0.5 to 10% by weight affects the dispersibility of the phosphor in the paste and the shape of the phosphor layer when applied between the partition walls. Is not preferred.

Further, the ratio of the phosphor powder in the phosphor paste is 30 to 60% by weight, the ratio of the binder resin is 5 to 20% by weight, and the remainder is mainly composed of an organic compound, an organic solvent and the like. Is preferred.

Finally, only the phosphor powder contained in the phosphor paste remains after the firing step to form a phosphor layer, so that the phosphor powder content in the phosphor paste is 30%.
It is preferably about 60% by weight. If the content is less than 30% by weight, the phosphor layer becomes thin, and the luminance tends to decrease. On the other hand, when the content exceeds 60% by weight, the viscosity of the paste becomes high, and when the paste having the ejection holes is applied between the partition walls, the ejection property and the applicability tend to decrease. The content of the phosphor powder is more preferably 40 to 60% by weight.
It is.

Further, as deeply related to the applicability of the phosphor paste and the shape of the phosphor layer to be formed,
The relationship between the amount of phosphor powder and the amount of binder resin is important,
Phosphor powder: binder resin = 6: 1 to 2: 1 by weight ratio
It is preferable that

That is, in order to form a phosphor layer almost uniformly on both the side and bottom surfaces of the stripe-shaped partition walls already formed, and to realize an excellent image display with high luminance.
It is preferable that the weight ratio is satisfied.

If the amount of the phosphor powder exceeds six times the binder resin, the thickness of the phosphor layer on the side wall of the partition wall increases, and
If less than twice, the bottom surface tends to be thick. More preferably, phosphor powder: binder resin (weight ratio) = 5:
1-3: 1.

The content of the binder resin in the phosphor paste of the present invention is preferably 5 to 20% by weight. If the content is less than 5% by weight, it is not possible to satisfy the preferable ratio of the phosphor powder: binder resin (weight ratio) and the phosphor powder in the phosphor paste.
If it exceeds 20% by weight, the viscosity of the paste tends to be too high.

The phosphor paste is preferably fired at a relatively low temperature of about 400 ° C. where deterioration of the phosphor powder is small, and in view of the fact that it can be fired at such a low temperature, methyl cellulose, ethyl cellulose, propyl cellulose is used as a binder resin. It is preferable to use a cellulosic resin such as hydroxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxymethylpropylcellulose and hydroxyethylpropylcellulose. In particular, methyl cellulose and ethyl cellulose are more preferable in terms of dispersibility of the phosphor powder.

Further, among the cellulose resins, the solution viscosity of a 5% by weight solution using a mixed solvent of toluene / ethanol (mixing ratio 80/20) is 0.005 to 0.5.
It is preferable that the cellulose resin is 025 Pa · s. When the solution viscosity is higher than 0.025 Pa · s, the viscosity of the phosphor paste tends to increase,
Coating properties may be reduced. On the other hand, when the solution viscosity is 0.0
When the viscosity is lower than 05 Pa · s, the amount of the binder resin necessary for obtaining an appropriate viscosity as the phosphor paste increases, and it is difficult to maintain the phosphor powder: binder resin ratio preferred in the present invention.

In the phosphor paste of the present invention, it is preferable to use terpineol (terpineol) as a solvent because the solvent of the binder resin is high, the phosphor powder is sufficiently dispersed, and the coating property is excellent. .
Commercial terpineol is a mixture of three isomers,
It is a liquid having a boiling point of 217 to 219 ° C.

However, since the binder resin has good solubility in terpineol, when terpineol is used as a solvent, the viscosity of the phosphor paste tends to increase. Therefore, the solvent may be a mixed solvent containing alcohols in addition to terpineol,
Dissolves a sufficient amount of binder resin to keep the coatability and the thickness of the phosphor layer to the required level, and is preferable in that the viscosity of the phosphor paste is maintained at a suitable level for discharge from the die. .

The alcohol is not particularly limited as long as it is soluble in terpineol. Among them, aromatic alcohols have a boiling point of about 200 to about the same as that of terpineol.
It is around 250 ° C., which is preferable in that the paste viscosity is reduced.

As the aromatic alcohol, for example, 2
-Phenoxyethanol, benzyl alcohol, γ-phenylallyl alcohol, dimethylbenzylcarbinol, β-phenylethyl alcohol and the like. The aromatic alcohol itself cannot completely dissolve the cellulosic resin, and the dispersibility of the phosphor powder is relatively low. However, it does not pose a problem since the coexisting terpineol sufficiently functions. Benzyl alcohol is particularly preferably used in view of the solubility of the binder resin.

The phosphor powder which emits red, green or blue light used in the phosphor paste of the present invention is not particularly limited.
₂ O ₃ : Eu, YVO ₄ : Eu, Gd ₂ O ₃ : Eu, (Y,
Gd) BO ₃ : Eu, YBO ₃ : Eu and the like.
In the phosphor emitting green light, Zn ₂ SiO ₄ : Mn, BaAl
₁₂ O ₁₉ : Mn, BaMgAl ₁₆ O ₂₆ : Eu, Mn and the like. For a blue-emitting phosphor, CaWO ₄ : P
b, Y ₂ SiO ₅ : Ce, BaMgAl ₁₀ O ₁₇ : Eu and the like.

The particle size of the phosphor powder to be used is selected in consideration of the line width, partition spacing and thickness of the phosphor layer pattern to be produced. , The cumulative average particle diameter measured by wet measurement using water as a dispersion medium) is 0.5 to 15 μm, more preferably 0.5 to 6 μm, and the specific surface area is 0.1 to ⁵ m ² / cc; More preferably, it is 0.5 to ⁴ m ² / cc.

If the cumulative average particle size is less than 0.5 μm or the specific surface area exceeds 5 m ² / cc, the powder becomes too fine, so that the phosphor powder is apt to agglomerate and the discharge holes may be clogged. . When the cumulative average particle diameter exceeds 15 μm or the specific surface area is less than 0.1 m ² / cc, it is difficult to form a uniform and smooth phosphor layer having a target thickness (for example, 20 μm).

Further, the maximum particle size of the phosphor powder is 40 μm.
m or less, and even 20 μm or less,
This is preferable because troubles such as clogging at the time of ejection from a die hole of 200 μm can be reduced.

When the particle size condition of the phosphor powder is within the above range, a highly accurate pattern shape can be obtained, the luminous efficiency of the phosphor is good, and the life is prolonged.

The viscosity of the phosphor paste is preferably from 1 to 100 Pa · s, more preferably from 10 to 50 Pa, from the viewpoint of being suitable for applying the phosphor paste between the partition walls by discharging from a die having discharge holes. -It is s. Such a viscosity can be achieved, for example, by including 5 to 20% by weight of a cellulose resin having the above-mentioned specific solution viscosity in the phosphor paste as a binder resin.

The above viscosity can be measured by a rotational viscometer method or the like. Of these, 25 ° C using a B-type viscometer
At a shear rate of 1.2 to 24 s ^-1
It is a value measured in the range of the degree.

In the present invention, the phosphor paste has a viscosity of 1 to 50 Pa · s, and the phosphor powder contained has an average particle size of 0.5 to 15 μm and a specific surface area of 0.1 to ⁵ m ^2.
/ Cc, the maximum particle size is 40 μm or less, and the binder resin has a viscosity of 0% when dissolved at a concentration of 5% by weight in a mixed solution of a cellulose resin (more preferably, toluene: ethanol (mixing ratio 80:20)). 0.005 to 0.025
(Pa.s cellulose-based resin) is particularly preferred.

In the phosphor paste of the present invention, for example, a binder resin is heated and dissolved in a solvent using a stirrer (80 ° C.).
The binder solution thus prepared is preliminarily kneaded with a phosphor powder and an organic compound using a planetary mixer or the like. And it can manufacture by uniformly dispersing using a three roll, a ball mill, etc.

Next, a PD using the phosphor paste of the present invention
A preferred method of manufacturing the P substrate will be described.

The PDP substrate is made of, for example, three kinds of phosphors mainly composed of a phosphor powder, a binder resin and a solvent which emit light of any one of red, green and blue colors and having a pH of 7.5 to 11. The paste can be manufactured by a method in which the paste is discharged from a die having discharge holes, applied in stripes between partition walls on a glass substrate, and then fired to form a phosphor screen.

At this time, it is preferable that after the phosphor paste is applied, the paste is dried before firing and the firing is performed at a relatively low temperature of about 400 to 450 ° C.

According to this method, a phosphor layer capable of obtaining a sufficient luminance with a uniform thickness is formed on the side and bottom of the partition wall, and a good PDP substrate can be easily manufactured.

The method of applying the phosphor paste at this time will be described in detail with reference to the drawings.

FIG. 1 shows a glass substrate on which partition walls are formed, on which a phosphor paste is applied. Glass substrate 2
Has a pitch of 100 to 430 μm and a line width of 15 to 60 μm.
m, and a stripe-shaped partition wall 3 having a height of about 80 to 150 μm is formed.
The partitions are formed so that their cross sections are substantially rectangular, and the phosphor paste is applied in cells partitioned by these partitions to form red, green, and blue striped phosphor layers. .

That is, as shown in FIG. 2, a red phosphor paste layer 4, a green phosphor paste layer 5, and a blue phosphor paste layer 6 are repeatedly formed for each color, and one stripe of three red, green, and blue stripes is formed. By forming one pixel line, a substrate for a color PDP is obtained.

As described above, the technique of applying the phosphor paste is an important technique that affects the quality of PDP, and a screen printing method has been used so far. When the partition pitch is 100 to 430 μm as described above, the application pitch of the phosphor paste in the case of applying three colors is 300 to 12
If the partition line width is 50 μm, the width between the partition walls to which the paste is applied is 50 to 380 μm. The phosphor paste extruded between the partition walls from the screen printing plate on which such a pattern is formed is transferred to the side surfaces of the partition walls, and then descends on the partition wall side surfaces under the own weight of the phosphor paste. It is thought that the coating layer of the phosphor paste is formed on the side surface and the bottom portion of the partition wall.

Therefore, if the viscosity of the phosphor paste is low, the paste concentrates on the bottom and the thickness of the side wall of the partition wall becomes thin, which causes a loss of luminance and a decrease in luminance at a wide viewing angle, and a high viscosity. In this case, it is effective to secure the luminance, but it is necessary to carefully set the application conditions.

Further, in the case of application by such a screen printing method, the top of the partition walls may be contaminated with the paste of each color due to the problem of the wraparound of the paste on the back surface of the screen plate material and the problem of the positioning accuracy. How to remove such unnecessary paste is a very important problem from the viewpoint of improving the yield of the glass substrate.

From this point of view, it can be said that a preferable method of applying the phosphor paste is to apply the phosphor paste by discharging it from a base having discharge holes in order to manufacture a high-definition glass substrate.
Specifically, as shown in FIG. 4, from a die having one or a plurality of discharge holes 7 (the shape of the discharge portion is a flat plate, a nozzle or needle, and the hole shape is circular, elliptical, slit, or the like), This is a method in which the step of discharging and applying any one of the phosphor pastes 8 of red, green and blue is repeated for each color, and a phosphor layer is formed through a drying and baking step. At this time, it is preferable to perform drying each time each color is applied.

In such an application method, it is also possible to apply a method in which each color phosphor paste is ejected from a base having ejection holes for simultaneously ejecting three colors of red, green and blue.

As a method of discharging the phosphor paste from the die, it is preferable to continuously pressurize the paste with a certain range of pressure and discharge the paste with the pressure. Thereby, the discharge amount of the paste can be kept constant,
A stable coating thickness can be obtained.

After the phosphor paste is discharged from the discharge holes and applied between the partition walls, in a heating step such as drying and baking,
Organic components and organic solvents are evaporated or decomposed and removed,
A target red phosphor layer 4 ′, a green phosphor layer 5 ′, and a blue phosphor layer 6 ′ composed of only phosphor powder are formed on the substrate (FIG. 3).

Hereinafter, the present invention will be described specifically with reference to Examples, but it should not be construed that the invention is limited thereto. The concentration (%) is% by weight unless otherwise specified.

[0059]

Example 1 Phosphor powder 40%, ethyl cellulose (binder resin)
10%, 3- (dibutylamino) propylamine 2%,
Benzyl alcohol 38% and terpineol 10%
Was dissolved and pre-kneaded by a planetary mixer, and then dispersed by three rollers to prepare a phosphor paste. The ratio of the phosphor powder to the binder resin in this paste was 4: 1, and the viscosity of the paste was 14 for red, 18 for green, and 1 for blue.
It was 5 Pa · s. The pH of 3- (dibutylamino) propylamine is 8.5, and the pH of the phosphor paste is 7.9.
was.

The phosphor powder emits (Y, Gd) for emitting red light.
Three kinds of phosphor pastes were prepared using BO ₃ : Eu, Zn ₂ SiO ₄ : Mn for green light emission, and BaMgAl ₁₀ O ₁₇ : Eu for blue light emission. The cumulative average particle diameter, the maximum particle diameter, and the specific surface area of each color phosphor powder were as follows.

[0061] R ^{phosphor: 2.7μm, 13μm, 3.1m 2 /} cc G ^{phosphor: 3.6μm, 20μm, 2.5m 2 /} cc B phosphors: 3.7μm, 12μm, 2.3m ² / cc Each of these phosphor pastes was filtered through a 400-mesh stainless steel wire mesh, and then led through a pipe to a base.
Red, green, and blue pastes were applied in a stripe shape on a glass substrate on which 961 partition walls each having a thickness of 20 μm, a height of 120 μm, and a width of 30 μm were formed.

The coating was carried out by means of a die (L / D = 20) in which five needles each having a diameter of 150 μm and having a discharge hole with a diameter of 150 μm and having a pitch of 660 μm were press-fitted at the tip. The bases are 2 for each of the red, blue and green phosphor pastes.
Each group was used. The two bases were set side by side at a distance of 105.6 mm in the direction perpendicular to the partition wall direction, synchronized, and simultaneously run in the same direction at the same speed. The distance between the tip of the needle and the upper end of the partition was set to 80 μm. Then, the discharge pressure was adjusted to 250 kPa with a dispenser, and a fixed amount of the phosphor paste was discharged and applied between the partition walls while the base was running parallel to the partition walls at a constant speed of 10 mm / s. First, a red phosphor paste is applied between predetermined partition walls.
0 was applied at a time. At this time, two bases are placed at 3300 in the direction perpendicular to the partition wall direction at the position where the ten coatings are completed.
It was moved by μm. Next, the coating was applied between the 10 partition walls while the die was running in the reverse direction in the same manner. This process was repeated to apply 320 red phosphors at predetermined positions. After the completion of the coating, the coating was dried at 80 ° C. for 40 minutes with the coated surface facing upward. next,
320 blue phosphor pastes were similarly applied between the adjacent partitions coated with the red phosphor and dried. Next, 320 green phosphor pastes were similarly applied between the adjacent partitions coated with the blue phosphor and dried. Then, the obtained glass substrate was baked at 400 ° C. for 30 minutes.

These steps were continuously performed on 20 substrates, but no problems such as clogging of the discharge holes of the base and the pipes were found.

When the thickness of the side surface and the bottom portion of the fired phosphor layer were observed by an electron microscope, the phosphor for each color was formed in a stripe shape with a thickness of 20 ± 3 μm on the side surface and the same thickness of 20 ± 3 μm on the bottom. A substrate was obtained.

When the phosphor paste 10 days after the preparation was sufficiently stirred with a planetary mixer and applied in the same manner, the same result as immediately after the preparation of the paste was obtained.

Example 2 The same procedure as in Example 1 was repeated except that the alkaline organic compound of Example 1 was changed to 3-ethoxypropylamine so that the concentration was 1.5% and benzyl alcohol was 38.5%. A PDP substrate was manufactured.

The pH of 3-ethoxypropylamine is 1
2. The pH of the phosphor paste was 9.0. As in Example 1, a good phosphor shape was obtained, and no problems such as clogging of the discharge holes of the base and the pipes occurred.

Comparative Example 1 A phosphor paste and a PDP substrate were manufactured in the same manner as in Example 1 except that 3- (dibutylamino) propylamine of Example 1 was not added and the concentration of benzyl alcohol was changed to 40%. . The pH of the phosphor paste was 6.5.

As a result immediately after the preparation of the phosphor paste, the same good results as in Example 1 were obtained. However, after 10 days from the preparation, the phosphor was fixed to the bottom of the container, and the planetary mixer was used. It was not possible to knead with the stirring degree. For this reason, the scraper was scraped off with a scraper, and a well-stirred one was used. However, clogging of the discharge hole of the die frequently occurred. Again, it was necessary to disperse with three rollers or the like.

[0070]

The phosphor paste of the present invention is a phosphor paste for forming a phosphor screen by being applied between partition walls on a glass substrate for PDP, and is one of red, green and blue colors. The main component of the phosphor paste, the binder resin, and the solvent that emits light, and the phosphor paste has a pH of 7.
Since it is 5 to 11, the phosphor powder is excellent in dispersibility, applicability and handleability. In particular, by applying the method of applying the phosphor paste between the barrier ribs by discharging from a die having a discharge hole, the phosphor paste can be accurately applied in the cell, and a more excellent PDP substrate can be obtained. .

[Brief description of the drawings]

FIG. 1 is a schematic view showing an example of a glass substrate on which a partition used to carry out the present invention is formed.

FIG. 2 is a PDP after applying the phosphor paste of the present invention.
It is a schematic diagram which shows an example of the board for use.

FIG. 3 is a schematic view showing an example of a PDP substrate after firing.

FIG. 4 is a view schematically showing an example of a method for applying a phosphor paste of the present invention.

[Explanation of symbols]

 1: electrode 2: glass substrate 3: partition wall 4: red phosphor paste layer 4 ': red phosphor layer 5: green phosphor paste layer 5': green phosphor layer 6: blue phosphor paste layer 6 ': blue fluorescence Body layer 7: Discharge hole 8: Phosphor paste

Claims (9)

[Claims] 1. A phosphor paste for forming a phosphor screen between partition walls of a plasma display panel, comprising a phosphor powder, a binder resin and a solvent as main components, and having a pH of 7.5 to 7.5. 11. A phosphor paste, which is 11. 2. The phosphor paste according to claim 1, comprising an organic compound having a pH of 7.5 to 12. 3. The organic compound as a liquid at 25 ° C.
The phosphor paste according to the above. 4. The organic compound has a boiling point at normal pressure of 150 to
The phosphor paste according to claim 2, wherein the temperature is 300 ° C. 5. 5. A phosphor powder comprising 30 to 60% by weight, a binder resin of 5 to 20% by weight, an organic compound and an organic solvent, wherein the weight ratio of the phosphor powder to the binder resin is 6:
The phosphor paste according to any one of claims 1 to 4, wherein the ratio is 1 to 2: 1. 6. The method according to claim 1, wherein the viscosity is 1 to 100 Pa · s.
The phosphor paste according to any one of Items 1 to 5, wherein 7. The phosphor paste according to claim 1, wherein the binder resin is a cellulosic resin. 8. The phosphor paste according to claim 1, wherein the solvent is a mixed solvent containing terpineol and an aromatic alcohol. 9. A phosphor powder which emits any one of red, green and blue colors, a binder resin and a solvent as main components.
Three types of phosphor pastes having H of 7.5 to 11 are discharged from a die having discharge holes, applied in stripes between partition walls on a glass substrate, and then fired to form a phosphor screen. A method for manufacturing a substrate for a plasma display panel, comprising: