JP2003112947A - Glass paste for plasma display panel, burning method therefor, and dielectric material or barrier material obtained by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide inexpensive glass paste for PDP (plasma display panel) of high quality which can be applied to the display of a large television monitor, a computer, or the like, can prepare a fine and dense film, and can enhance whiteness, to provide a burning method therefor, and to obtain a PDP dielectric material or a PDP barrier material by using the same. SOLUTION: The glass paste for PDP contains glass powder (A) and inorganic oxide powder (B). In the composition of each component, the content of the glass powder (A) is 80 to 95 wt.%, and the content of the inorganic oxide powder (B) is 5 to 20 wt.%, and, the particle diameter (particle size distribution D 50 value) of the glass powder (A) is 2.0 to 6.0 μm, and that of the inorganic oxide powder (B) is <=1.5 μm.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a glass paste for a plasma display panel (hereinafter referred to as PDP), a firing method thereof, and a PDP dielectric material or PD using the same.
Regarding the P barrier material, more specifically, it is an inexpensive and high-quality PD that can be used for displays such as large-sized TV monitors and computers, can obtain a dense film, and can improve whiteness.
Glass paste for P, firing method thereof and P using the same
It relates to a DP dielectric material or a PDP barrier material.

[0002]

2. Description of the Related Art In recent years, attention has been focused on thin and power-saving PDPs, and they are greatly expected as future wall-mounted high-definition television monitors. A PDP is a display panel in which a pair of glass plates are opposed to each other with a minute gap therebetween, and the periphery is sealed to provide a discharge space. A rare gas such as xenon enclosed in the discharge space is excited by the discharge, The phosphor emits light with energy to display an image.

Of the pair of glass plates, the glass plate on the side where an image is displayed on the PDP is called the front plate and the other is called the rear plate. A general back plate has a structure as shown in FIG. The PDP rear plate (1) has barriers (13) arranged in parallel in stripes, and electrodes (also called one address electrode) parallel to the barriers (13) on the bottom surfaces of the recesses of these barriers (13). 11) is formed, and this electrode (1
A dielectric layer (12) is formed so as to cover the surface of 1). Furthermore, the phosphors (14) indicated by R, B, and G, which are excited by ultraviolet rays, are applied to the wall surfaces of these barriers (13).

The PDP back plate (1) is formed by first patterning a stripe-shaped electrode (11) on a glass substrate (10) with a thick film material such as silver paste, followed by firing, and then forming this electrode ( A thick film material such as a dedicated glass paste to be the dielectric layer (12) is applied onto 11) and baked, and finally, a glass paste for barrier is applied onto the dielectric layer (12). And after patterning the barrier (13),
It is manufactured by firing.

Up to now, as a glass paste for PDP, a composition mainly containing low melting point glass has been used.
For example, Japanese Patent Application Laid-Open No. 11-297123 discloses a firing paste composition in which a low-melting glass, an inorganic filler, and a binder resin are main constituent components, and the inorganic filler is low-order titanium oxide. According to this invention, the low-order titanium oxide is changed to white titanium oxide when it is baked at 400 ° C. or higher, so that a black partition pattern can be formed on the dielectric layer, and the pattern shape and defects can be easily confirmed. It is said that it is possible to form a partition wall having a desired high reflectance.

Further, JP-A-2001-31446, a _P 2 _{O 5} based glass composition having a low melting _{point, P} 2 O
_A PbO-free low-melting-point glass composition containing ₅ , Al ₂ O ₃ , and B ₂ O ₃ as essential components is proposed, and it is said that a lead-free PDP back plate that can deal with environmental problems can be manufactured.

As described above, on the market, a glass paste capable of obtaining a dense film and improving whiteness is required as a material for manufacturing a PDP back plate, but such a glass paste is available. The current situation is that it is difficult.
To manufacture a large wall-mounted high-definition TV monitor,
Although a large amount of glass paste is consumed, the glass pastes proposed so far are expensive and have been a cause of impeding the practical use of PDPs.

Under such circumstances, there has been a strong demand for the appearance of an inexpensive and high-quality glass paste for PDP which can obtain a dense film and improve the whiteness.

[0009]

In view of the above-mentioned problems of the prior art, the object of the present invention is to utilize it for a display of a large-sized television monitor or a computer, a dense film can be obtained, and whiteness can be improved. An object of the present invention is to provide an inexpensive and high-quality glass paste for PDP, a firing method thereof, and a PDP dielectric material or PDP barrier material using the same.

[0010]

Means for Solving the Problems As a result of intensive studies for solving the above problems, the present inventor has found that a glass paste for a plasma display panel containing a glass powder (A) and an inorganic oxide powder (B). By optimizing the particle size of the glass powder (A) and the particle size of the inorganic oxide powder (B), and optimizing the mixing ratio of the glass powder (A) and the inorganic oxide powder (B). The present inventors have completed the present invention by finding that a glass paste capable of supplying a barrier material for PDP and a high-quality dielectric material can be obtained at low cost.

That is, according to the first aspect of the present invention,
P containing glass powder (A) and inorganic oxide powder (B)
In the glass paste for DP, the composition of each component is 80 to 95% by weight of glass powder (A) and inorganic oxide powder (B).
5 to 20% by weight, and the particle size of each component (particle size distribution D
The glass paste for PDPs is characterized by having a glass powder (A) of 2.0 to 6.0 μm and an inorganic oxide powder (B) of 1.5 μm or less.

According to a second aspect of the present invention, the first aspect
In the invention, the glass powder (A) is P in terms of oxide.
bO 5 to 70% by weight, B_TwoO_Three  1 to 15% by weight, S
iO _Two  5-40% by weight, Al_TwoO_Three  15% by weight or less
Below, ZnO 10 wt% or less, BaO + CaO 10 wt
Amount% or less, K_TwoO + Na_TwoO 2 wt% or less composition
A glass paste for PDP, which is characterized by
Be done.

According to the third aspect of the present invention, the first aspect
In the invention, the inorganic oxide powder (B) is Al
There is provided a glass paste for PDP, which is at least one selected from the group consisting of ₂ O ₃ , ZrO ₂ and TiO ₂ .

According to a fourth aspect of the present invention, the first aspect
The glass paste for PDP according to any one of the inventions 1 to 3 is applied to a glass substrate and then fired in a temperature range from 30 ° C lower to 30 ° C higher than the softening point of the glass powder (A). A method for firing a PDP paste is provided.

According to a fifth aspect of the present invention, the first aspect
A PDP dielectric material comprising the glass paste for PDP according to any one of the inventions 1 to 3 is provided.

Further, according to the sixth invention of the present invention, there is provided a PDP barrier material comprising the glass paste for PDP according to any one of the first to third inventions.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The glass paste for PDP of the present invention, the firing method thereof, and the PDP dielectric material or PDP will be described below.
The barrier material will be described in detail.

1. Glass paste for PDP The glass paste for PDP of the present invention comprises at least glass powder (A) and inorganic oxide powder (B).

A Glass Powder In the present invention, the glass powder is a dielectric material for PDP capable of forming a dense film, and a PDP capable of improving whiteness.
It is the basic component of the barrier material. The glass powder has a function of adhering particles of glass powder to each other and particles of glass powder and inorganic oxide powder.

The content of the glass powder is preferably 80 to 95% by weight, more preferably 85 to 90% by weight. If the content of the glass powder is less than 80% by weight, the amount of the inorganic oxide powder is relatively large, and a dense dielectric material cannot be realized. On the other hand, if the glass powder content exceeds 95% by weight, a dense dielectric film can be formed, but since the inorganic oxide powder content is low, white P
The DP barrier and the dielectric cannot be realized. In addition, P
When used as a DP barrier material, glass content is 95% by weight
When the amount is larger, the amount of the inorganic oxide powder that functions as an aggregate is too small, which causes a problem that the PDP barrier melts and flows during firing to collapse.

The glass powder has a particle size distribution D50 value of 2.0 to 6.0 μm. If it is finer than this, it becomes difficult to control the firing temperature, and if it is higher than a predetermined temperature, the PDP barrier collapses. On the other hand, if the particle size is larger than 6.0 μm, it becomes impossible to form a dense dielectric. In particular, if the PDP dielectric cannot be formed densely, there is a problem that a pinhole is generated in the dielectric film, the address electrode cannot be protected, and the address electrode is broken due to discharge.

The composition of the glass powder is PbO in terms of oxide.
  5 to 70% by weight, B_TwoO_Three  1-15% by weight, SiO
_Two  5-40% by weight, Al_TwoO_Three  15% by weight or less, Z
nO 10 wt% or less, BaO + CaO 10 wt% or less
Below, K_TwoO + Na_TwoO 2 wt% or less. Glass powder
If the powder composition is in this range, the coefficient of thermal expansion of the glass powder
Is 80 × 10^-7The following is widely used in PDP
Equivalent to or smaller than soda lime glass substrate
It shows the minimum value and shows excellent matching with the substrate. In addition,
Thermal expansion coefficient of soda lime glass substrate is 80 × 10
^-7~ 83 × 10 ^-7It is widely known that
The coefficient of thermal expansion of glass powder is extremely different from that of the substrate.
For example, the substrate, the dielectric film and the PDP barrier may be warped or distorted.
This causes defects such as collapse of the PDP barrier.

A particularly preferred composition is PbO in terms of oxide.
50-65 _{wt%, B} 2 O 3 _3~15 wt%, Si
O ₂ 10 to 35 _wt%, Al _{2 O} 3 10 wt% or less, 8 wt% ZnO less, BaO + CaO 5 wt%
Or _less, and K 2 O + _Na 2 O 2 wt% or less. This composition exhibits a softening point in the range of 500 ° C to 600 ° C.

B Inorganic Oxide Powder The inorganic oxide powder has a function as a pigment for realizing a white PDP barrier and a dielectric, and a function as an aggregate of the PDP barrier and the dielectric.

The content of the inorganic oxide powder must be lower than that of the glass powder, and is 5 to 20% by weight, preferably 8%.
-15% by weight. If the content is less than 5% by weight, a dense dielectric film can be formed, but a white PDP barrier or dielectric cannot be realized. When this is used as a PDP barrier material, the function as an aggregate is too weak, and the PDP barrier melts during firing, causing a problem of flow and collapse. On the other hand, if it exceeds 20% by weight, there is a problem that a dense dielectric material cannot be realized.

The finer the particle size of the inorganic oxide powder, the PD
Since the whiteness of the P barrier and the dielectric film is improved and the denseness of the dielectric film is improved, the particle size distribution D50 value is set to 1.5 μm or less. When the particle size is larger than 1.5 μm, the denseness of the dielectric film is impaired, which is not preferable. In particular, the PDP dielectric has a problem that voids are likely to occur when the particle size is larger than 1.5 μm.

The inorganic oxide powders are Al ₂ O ₃ and ZrO ₂
And at least one selected from the group consisting of TiO ₂ . With these inorganic oxides, the particle size is 1.5 μm
The following products are readily available. The dielectric or barrier of the PDP is preferably white, and the emission efficiency of the PDP can be improved by reflecting the light emitted from the phosphor. To form a white PDP barrier or dielectric, it is desirable to select TiO ₂ as the inorganic oxide powder.

2. Firing method From the glass paste of the present invention to PDP dielectric material, PDP
To produce the barrier material, the paste is applied to a glass substrate and the softening point of the glass powder is 30 ° C. below 3
Firing is performed at a temperature higher by 0 ° C, that is, in the temperature range of 470 to 630 ° C.

When the firing temperature is low, the PDP dielectric material is
Since sintering between the particles of the glass powder is insufficient, voids between the particles are not filled and a dense fired film cannot be obtained. On the other hand, if the firing temperature is too high, a small amount of residual voids grow between the particles of the glass powder, and bubbles form pinholes. Such voids and pinholes are fatal defects for the PDP dielectric. Therefore, the firing temperature is preferably 20 ° C. lower to 20 ° C. higher than the softening point of the glass powder, that is, 480 to 620 ° C.

The PDP barrier material of the present invention is optimally fired at a temperature 50 ° C. lower than the softening point of the glass powder to the softening point, that is, 450 to 600 ° C. If the firing temperature is too low, the glass powder will not be sufficiently sintered and sufficient strength cannot be obtained as a PDP barrier. On the other hand, if the firing temperature is too high, the material melts and flows, making it impossible to obtain a PDP barrier having a desired shape. A particularly preferable firing temperature is from a temperature 30 ° C. lower than the softening point of glass to the softening point.

3. PDP Barrier Material and PDP Dielectric Material The glass paste of the present invention can be mixed with an organic binder (organic vehicle) and formed into a thick film paste or a green sheet to form a PDP barrier material and a PDP dielectric material.

By printing and firing the thick film paste on a glass substrate by screen printing into a predetermined shape, a dielectric film and a PDP barrier can be formed.
A P back plate is formed. Also, a PDP dielectric material and P formed as a thick film paste or a green sheet
The PDP back plate can also be obtained by applying or transferring the DP barrier material to a predetermined substrate to form a desired barrier shape by sandblasting or the like and firing.

The particle size of the inorganic oxide powder (particle size distribution D
By setting the 50 value) to 1.5 μm or less, the PDP dielectric and the barrier can be formed of the same material.

[0034]

EXAMPLES The present invention will be described below based on examples.
The present invention is not limited thereby.

(Measurement of Leakage Current) On a soda lime glass substrate on which silver electrodes have been formed in advance, a baked film of a thick film glass paste is formed so as to cover the silver electrodes. Next, the glass substrate on which the fired film is formed is immersed in a 5 wt% NaCl aqueous solution. Using the glass substrate on which this fired film is formed as a cathode, a voltage of 5 V is applied to electrolyze the NaCl aqueous solution. The current value (leakage flow) during electrolysis is measured. Among the obtained current values, those showing 0.1 mA or more have voids or pinholes in the thick film glass paste fired film, and it is judged that the current leaks, and the number is recorded. The NaCl used is a commercially available reagent.

Examples 1 to 6 (Comparative Examples 1 to 6) PbO, B ₂ O ₃ , SiO ₂ and Al were used as glass powder.
Glasses A to F having the compositions shown in Table 1 were prepared by combining the respective components of ₂ O ₃ , ZnO, BaO, and K ₂ O + Na ₂ O. Each of these glass powders was melted and pulverized with a ball mill to a predetermined particle size. Table 1 It was shown to.

[0037]

[Table 1]

The glass powder thus obtained was mixed with an inorganic oxide in a ratio shown in Table 2 to prepare a glass paste. Next, an organic vehicle was added to the mixed powder of the glass powder and the inorganic oxide and mixed by a three-roll mill to obtain a thick film glass paste. The organic vehicle was prepared by mixing terpineol and ethyl cellulose in advance. Further, the particle size of the inorganic oxide used was measured by HRA type Microtrac manufactured by Nikkiso, and the results are also shown in Table 2.

[0039]

[Table 2]

The thick film glass paste thus produced was
It was screen-printed on a soda-lime glass substrate and baked. The film thickness was set to 30 μm to 40 μm after firing. A belt-type firing furnace having a peak temperature shown in Table 3 was used for firing, and the peak temperature was held for 30 minutes. The denseness of the obtained fired film was evaluated by the above-mentioned leak current measuring method. In Table 3, after firing each glass paste,
The result (leakage number) of the leak current is shown. Regarding the number of leaks in Table 3, the smaller the number of leaks, the more dense the film is formed as the PDP dielectric. Table 4 shows the state of warpage of the sample for which the leak current was measured (soda lime glass substrate obtained by firing glass paste). The absence of warpage is more suitable as a PDP dielectric material.

[0041]

[Table 3]

[0042]

[Table 4]

Next, a glass powder having the composition shown in Table 2 was mixed with an inorganic oxide, an organic vehicle was added thereto, and the mixture was mixed with a three-roll mill to obtain a thick film glass paste. Thick film glass paste on a soda-lime glass substrate with a width of 100 μm,
The pattern was screen-printed in a stripe pattern having a pitch of 300 μm and dried at 125 ° C. The printing process and the drying process were repeated to form a film having a film thickness of 150 μm after firing. The dried product obtained is baked to form a PDP.
Formed a barrier. For firing, a belt-type firing furnace having a peak temperature shown in Table 5 was used, and the peak temperature was held for 15 minutes.

[0044]

[Table 5]

The obtained PDP barrier was observed under a microscope to confirm whether the barrier collapsed. If the barrier had been obtained, rub it with tweezers to see if the barrier collapsed. Table 5 shows the PD of each thick film glass paste
An evaluation result as a P barrier is shown. In addition, Table 6 shows a comprehensive evaluation of the evaluation results of the PDP dielectric and the barrier of each glass paste.

[0046]

[Table 6]

From these results, if the glass powder, the content of the inorganic oxide, and the particle size are within the specific ranges as in Examples 1 to 6, the desired PDP dielectric, It can be seen that it can form a barrier. On the other hand, as in Comparative Examples 1 to 6, if the glass powder, the content of the inorganic oxide, and the particle size are out of the specific ranges, the desired PDP dielectric and barrier cannot be formed in the predetermined temperature range. I understand.

[0048]

According to the present invention, it is possible to manufacture a high-quality dielectric material or barrier material for a PDP back plate at a low cost, and its industrial value is extremely large.

[Brief description of drawings]

FIG. 1 is an explanatory view showing a structure of a PDP back plate.

[Explanation of symbols]

1 Back plate 10 glass substrates 11 address electrodes 12 Dielectric layer 13 barriers 14 Phosphor

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4G062 AA08 AA09 BB01 BB04 DA03                       DA04 DA05 DB01 DB02 DB03                       DB04 DC03 DC04 DD01 DE01                       DE02 DE03 DF03 DF04 DF05                       DF06 DF07 EA01 EA10 EB01                       EB02 EB03 EC01 EC02 EC03                       ED01 EE01 EE02 EE03 EF01                       EG01 EG02 EG03 FA01 FA10                       FB01 FC01 FD01 FE01 FF01                       FG01 FH01 FJ01 FK01 FL01                       GA01 GA10 GB01 GC01 GD01                       GE01 HH01 HH03 HH05 HH07                       HH09 HH11 HH13 HH15 HH17                       HH20 JJ01 JJ03 JJ05 JJ07                       JJ10 KK01 KK03 KK05 KK07                       KK10 MM05 MM08 NN40 PP01                       PP03 PP04                 5C027 AA05 AA06 AA09                 5C040 GD07 GD09 GF18 GF19 JA21                       KA08 KA09

Claims (6)

[Claims] 1. A glass paste for a plasma display panel containing a glass powder (A) and an inorganic oxide powder (B), wherein the composition of each component is 80 to 95% by weight of the glass powder (A),
Inorganic oxide powder (B) is 5 to 20% by weight, and the particle size (particle size distribution D50 value) of each component is glass powder (A).
2.0-6.0 μm, inorganic oxide powder (B) 1.5 μm
A glass paste for a plasma display panel, characterized in that: 2. The glass powder (A) is Pb in terms of oxide.
O 5 to 70% by weight, B ₂ O ₃ 1 to 15% by weight, Si
O ₂ 5 to 40 wt%, Al ₂ O ₃ 15 wt% or less,
ZnO 10% by weight or less, BaO + CaO 10% by weight
The glass paste for a plasma display panel according to claim 1, having a composition of K ₂ O + Na ₂ O 2 wt% or less. 3. The inorganic oxide powder (B) is Al ₂ O ₃ ,
At least one of claim 1 of the plasma display panel glass paste, characterized in that selected from the group consisting of ZrO ₂ and TiO _2. 4. After applying the glass paste for a plasma display panel according to any one of claims 1 to 3 to a glass substrate, from a temperature 30 ° C. lower to a temperature 30 ° C. higher than the softening point of the glass powder (A). A method for firing a paste for a plasma display panel, which comprises firing at a temperature range of 1. 5. A plasma display panel dielectric material comprising the glass paste for plasma display panel according to claim 1. 6. A plasma display panel barrier material comprising the glass paste for plasma display panel according to claim 1.