JP2003054991A - Glass paste, transfer film and plasma display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a glass paste used as the starting material of a transparent dielectric formed in a plasma display panel and enabling shortening of baking time without lowering the transmittance of a dielectric layer. SOLUTION: Display electrodes 103 are aligned on a front glass substrate 102 and the glass paste which becomes a dielectric layer 104 is applied to cover a dielectric layer precursor 104a. Since a decomposition accelerating material 1042 which accelerates the decomposition of an organic component such as a resin contained in a dispersant 1041 is contained in the glass paste in such a way that the material 1042 comes in contact with the organic component, the material 1042 accelerates the decomposition of the organic component in baking. As a result, at the stage of melting of glass powder 1040, the organic component vanishes nearly thoroughly and bubbles of a gas generated by the decomposition of the organic component such as a resin are not trapped in the resulting dielectric layer 104.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a glass paste,
The present invention relates to a transfer film, a plasma display panel and the like.

[0002]

2. Description of the Related Art In recent years, in a color display device used for image display such as a television, a plasma display panel (Plasma Display Panel, hereinafter referred to as "PDP") is capable of displaying beautiful images and is a thin and large panel. It is attracting attention as a display device that can realize

A PDP is generally constructed by arranging a front panel and a rear panel facing each other. Figure 7 shows PD
It is a fragmentary sectional view of the front panel in P. As shown in the figure, the front panel includes a front glass substrate 1102, display electrodes 1103 lined up on the main surface of the front glass substrate 1102 on the rear panel side, and transparent electrodes covering the display electrodes 1103 and the front glass substrate 1102. Dielectric layer 11
04, and a protective layer 110 covering the surface of the dielectric layer 1104.
5 and 5.

When the PDP is driven, the light emitted from the phosphor layer (not shown) on the rear panel is converted into the protective layer 1105, the dielectric layer 1104, and the display electrode 110 on the front panel.
3 and the front glass substrate 1102 to be emitted light of the PDP. Therefore, it can be seen that the luminous efficiency of the PDP depends on the transmittance of the front glass substrate. In particular, the dielectric layer 1104 is thicker than the protective layer 1105 and the like, and the transmittance tends to decrease because of the necessity to insulate the display electrode 1103. Therefore, improvement of the transmittance is desired.

The formation of the dielectric layer 1104 is usually performed by coating the front glass substrate 1102 with a dielectric layer precursor made of glass paste dried by a paste method or a laminating method, and coating the dielectric layer precursor at a temperature of 500 ° C. or higher. A method is used in which the temperature is raised to calcination and the calcination is devised in order to improve the transmittance of the formed dielectric layer. That is,
Firing is generally performed in two steps: a decomposition step of decomposing an organic component such as a resin, a solvent and a surfactant contained in the glass paste, and a melting step of melting the glass powder.

First, in the decomposition step, a temperature (for example, 35) at which an organic component such as resin existing between glass powders can be decomposed without melting the glass powders.
Hold for a predetermined time (about 10 to 30 minutes) at 0 to 450 ° C. In particular, many organic components such as resins having a large molecular weight are not easily decomposed, but by providing the hold period of this decomposition step, the organic components contained in the glass paste are completely decomposed and disappeared.

Next, in the melting step, the temperature at which the glass powder begins to melt (for example, the softening point (50
After holding for a predetermined time (about 10 to 30 minutes) so that the temperature becomes about 0 ° C.) or more), the residual glass powder is melted and solidified by slow cooling. Here, when the organic components such as the resin remain without being completely decomposed in the decomposition step, they are decomposed in the melting step to generate gas. In that case, as shown in FIG. 7, the dielectric layer 1
The gas remains as bubbles 1104a in 104, which causes a decrease in the transmittance of the dielectric layer 1104. However, in the decomposition step, since the hold period for completely removing the organic component contained in the glass paste is provided, in the melting step, water and Gas generation is suppressed,
The decrease in the transmittance of the dielectric layer 1104 due to the generation of the bubbles 1104a is suppressed.

[0008]

By the way, in the above-mentioned firing, since the temperature has to be raised to a very high temperature of 500 ° C. or higher, the energy cost is high, and further firing time is required in order to reduce the manufacturing cost of the PDP. It is desired to shorten it. In order to shorten the firing time, it is possible to shorten the process time of the decomposition step.

However, in this case, the organic components such as the resin may remain without being completely decomposed in the decomposition step, and in that case, bubbles 1104a are generated inside the dielectric layer 1104 and the dielectric layer 1104 is formed. The transmitted light is scattered by the bubbles 1104a, and the dielectric layer 110
The transmittance of No. 4 is significantly reduced. On the other hand, although it is conceivable to shorten the time of the melting step, it is difficult to shorten the melting time of the glass powder because it becomes substantially constant in proportion to the type and temperature of the glass used.

Further, in an extreme case of the melting step, the glass powder is melted and the gaps between the powders are closed, while a large amount of oxygen is consumed by the combustion of the resin remaining between the glass powders. There is a problem that the inside of the glass becomes a reducing atmosphere and the glass is colored and the transmittance is lowered. Such a problem becomes more noticeable when a glass paste is coated on the front glass substrate 1102 by using a laminating method using a transfer film that uses more resin than the paste method.

[0011]

In view of the above problems, the present invention provides a glass paste, a transfer film, etc., which can shorten the firing time without lowering the transmittance of the dielectric layer to be formed. It is an object. In order to achieve the above object, the glass paste according to the present invention is a glass paste that is a starting material of a transparent dielectric material formed in a plasma display panel, and contains a glass powder and an organic component. And a decomposition-promoting substance that promotes decomposition of the organic component, and the decomposition-promoting substance is present in a region in contact with the organic component.

Generally, the glass powder dispersant contains an organic component such as a resin, a solvent, a surfactant and a polymerization initiator. Since the glass paste according to the present invention contains a decomposition promoting substance that promotes the decomposition of the organic component,
When heated to form the dielectric layer, the organic component is decomposed rapidly, and is almost completely decomposed before the glass powder is softened. Therefore, the gas generated when the organic component such as resin is decomposed is not confined in the dielectric layer, and the firing time can be shortened as compared with the conventional case without lowering the transmittance of the dielectric layer.

As the decomposition promoting substance, a catalyst which promotes the decomposition reaction of the organic component can be used. As a specific catalyst, a substance selected from at least one of Co, Mn, Zn, Ti, and Ni can be used. On the other hand, as the decomposition accelerating substance, a polymerization initiator capable of accelerating the initiation reaction when polymerizing the resin raw material can be used.

As the polymerization initiator, a radical polymerization initiator or an anionic polymerization initiator can be used. In addition, a catalyst that promotes the oxidation of the above organic components can be used as the decomposition promoting substance. As this catalyst, P
d, Pt, Co ₃ O ₄ , PdO, Cr ₂ O ₃ , Mn ₂ O ₃ , A
A substance selected from at least one of g ₂ O, CuO, MnO ₂ , CoO, and NiO can be used.

The transfer film according to the present invention is used for forming a transparent dielectric formed on a plasma display panel, and includes a support film and a dielectric layer precursor coated on the support film. A transfer film, wherein the dielectric layer precursor includes a glass powder, an organic component, a glass powder dispersant for dispersing the glass powder, and a decomposition promoting substance for promoting the decomposition of the organic component, The decomposition-promoting substance is present in a region in contact with the organic component.

With such a transfer film, the decomposition of the organic component contained in the dielectric layer precursor is accelerated during the firing as in the case of the above glass paste, so that the transmittance of the formed dielectric layer is increased. The firing time can be shortened without lowering. Here, as the organic component and the decomposition accelerating substance, the same ones as those used in the above glass paste can be used.

The method of manufacturing a PDP according to the present invention is
A method of manufacturing a PDP, comprising forming a dielectric layer on the front glass substrate by coating a front surface glass substrate with a glass paste and drying the glass paste to coat the dielectric layer precursor. When the glass paste is applied to the front glass substrate, the glass paste containing the decomposition promoting substance as described above is applied.

According to this, when the dielectric layer precursor is fired, the decomposition promoting substance can accelerate the decomposition of the organic component such as resin, so that the firing time can be shortened as compared with the conventional case. Further, since the organic component is decomposed quickly, the organic component disappears almost completely by the time the temperature near the softening point of the glass is reached, so that no bubbles are generated inside the dielectric layer.

Here, when firing the dielectric layer precursor, if the firing temperature is continuously raised to the softening point of the glass contained in the glass paste, the hold period in the decomposition step is provided as in the conventional case. Therefore, the firing time can be shortened. Further, the PDP according to the present invention
Is a front glass substrate on which a plurality of pairs of display electrodes are arranged, a dielectric layer covering the display electrodes is arranged, and a rear glass substrate which is arranged opposite to the side of the front glass substrate on which the display electrodes are arranged. The dielectric layer is formed by firing a glass paste, and the glass paste containing the decomposition promoting substance is used for the glass paste. Therefore, the firing time can be shortened. It is possible and the manufacturing cost is reduced.

This also has the same effect in the PDP in which the dielectric layer is formed by using the transfer film.

[0021]

DETAILED DESCRIPTION OF THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. The following embodiments and drawings of the present invention are for the purpose of illustration, and the present invention is not limited thereto. (First Embodiment) (1) Configuration of PDP First, the configuration of the PDP will be described.

FIG. 1 is a perspective view showing a part of the PDP in a developed state. As shown in the figure, the PDP includes a front panel 101 and a rear panel 111.
The protective layer 105 and the tops of the partition walls 115 arranged on the rear panel 111 are in contact with each other. Front panel 1
No. 01 has a plurality of display electrodes 103 arranged in a row on a front glass substrate 102 made of a sodium borosilicate glass formed by a float method, on which a dielectric layer 104 made of transparent glass and an oxide film are formed. A protective layer 105 made of magnesium (MgO) is coated in that order. The display electrode 103 is a transparent electrode 103a made of ITO provided linearly on the surface of the front glass substrate 102.
And silver or C arranged in a line on the transparent electrode 103a.
It is provided with a metal electrode 103b laminated with u-Cr-Cu. The display electrode 103 is not limited to this configuration, and may have a configuration in which the transparent electrode 103a does not exist.

The dielectric layer 104 is formed by melting glass powder described later and has a function of insulating the display electrode 103. The protective layer 105 is made of MgO and protects the dielectric layer 104 from sputtering due to discharge that occurs between the display electrodes 103. Back panel 111
Is the front glass substrate 10 in the rear glass substrate 112.
The address electrodes 113 are arranged in a row on the main surface on the side opposite to 1, the visible light reflection layer 114 is coated thereon, and the partition walls 115 are arranged in a row on the visible light reflection layer 114. Phosphor layers 116 that emit red, green, and blue are arranged between the partitions 115 in order of color.

The front panel 101 and the rear panel 111
Means that the protective layer 105 in the front panel 101 and the partition 115 in the rear panel 111 are arranged so as to be in contact with each other, and the edge portions of the respective panels 101 and 111 are sealing materials (not shown) such as frit glass. ) Is sealed. As a result, a space partitioned by the partition wall 115 is formed between the front panel 101 and the rear panel 111, and a discharge gas composed of an inert gas such as He—Ne is sealed in this space.

When the PDP is driven, discharge is generated between the display electrodes 103 by applying a periodic pulse to the pair of display electrodes 103 on the front panel 101. This discharge radiates ultraviolet rays from the discharge gas, which is converted into visible light by the phosphor layer 116. This visible light is transmitted to the protective layer 105, the dielectric layer 104,
The light is transmitted through the transparent electrode 103a and the front glass substrate 102, and the transmitted light allows the PDP to display an image.

(2) Method for Manufacturing Front Panel in PDP The present invention is characterized by the composition and firing method of the glass paste used for forming the dielectric layer 104 in the front panel 101. Therefore, the composition of the glass paste and the firing method will be described below while describing the method for manufacturing the front panel 101.

The front panel 101 is a front glass substrate 10.
2, the display electrodes 103 are arranged in a row, and the dielectric layer 1 is formed on the display electrodes 103.
It is formed by coating a glass paste to be 04, firing it to form a dielectric layer 104, and then coating a protective layer 105 thereon. 2 (a) to 2
(E) is a side view of the front panel 101 in each manufacturing process.

First, as shown in FIG. 2A, a front glass substrate 102 is prepared. Next, as shown in FIG. 2B, a display electrode 103 composed of a transparent electrode and a metal electrode is formed on one main surface of the front glass substrate 102 by a thin film method or a thick film method (a screen patterned into an electrode shape is formed). Screen printing method used, a method of forming a solid shape using a die coating method and then patterning using a photo method,
It is formed by using a laminating method or the like in which an electrode film processed into a film is transferred.

Then, as shown in FIG. 2C, a glass paste is applied onto the front glass substrate 102 on which the display electrodes 103 are formed by a method such as screen printing or die coating and dried to obtain a dielectric layer precursor. Form body 104a. The glass paste used to form the dielectric layer precursor 104a includes glass powder made of transparent glass, a solvent, a resin that serves as a binder while evenly dispersing the glass powder in the solvent, and the glass paste. And a decomposition promoting substance that accelerates decomposition or combustion of an organic component such as a resin or a solvent and reduces the molecular weight. The organic component means all the organic substances contained in the glass paste, and the glass paste may contain organic substances such as a surfactant and a polymerization initiator in addition to the resin and the solvent.

The above solvent becomes a viscous solution by dissolving the resin, and this solution functions as a dispersant for dispersing the glass powder, and the glass powder is evenly dispersed therein (hereinafter, the solvent and the resin). A mixture containing and is called a glass powder dispersant). This glass powder dispersant may contain a surfactant or a polymerization initiator, and may contain no solvent when the resin itself is a viscous liquid.

Here, the solvent has a good affinity with the glass powder and a good solubility of the resin, can give an appropriate viscosity required when the glass paste is applied, and easily evaporates. Is preferred. Specifically, acetic acid-n-butyl, BCA (butyl carbitol acetate), terpineol, or the like can be used. These may be used alone or in combination of two or more. This solvent is 40 wt% to the glass powder in order to keep the viscosity of the glass paste moderate.
% Or less, and more preferably 5 to 30 wt%.

The glass powder is not particularly limited, but one having a softening point in the range of 400 to 600 ° C. is preferable. For example, lead oxide, boron oxide,
A mixture of silicon oxide _{(PbO-B 2 O 3 -SiO} 2 system),
A mixture of zinc oxide, boron oxide and silicon oxide (ZnO-
B ₂ O ₃ -SiO ₂ -based), lead oxide, boron oxide, silicon oxide, a mixture of aluminum oxide (PbO-B ₂ O ₃ -Si
O ₂ -Al ₂ O ₃ system), lead oxide, zinc oxide, boron oxide,
A mixture of silicon oxide _{(PbO-ZnO-B 2 O} 3 -SiO
₂ ) Glass frit powder (for example, particle size 5
˜15 μm) can be used.

As the resin, for example, ethyl cellulose or acrylic resin can be used. The molecular weight of this resin is preferably about 4,000 to 300,000, as a polystyrene-equivalent weight average molecular weight measured by GPC, because it is easy to handle. Further, the amount contained in the glass paste is preferably 5 to 40 wt% with respect to the glass powder, and more preferably 10 to
30 wt% is preferable. This is because when the resin content is less than 5 wt% with respect to the glass powder, the viscosity when the paste is applied cannot be maintained,
This is because if the content exceeds wt%, it will take time for the resin to disappear at the time of firing to be described later, or the strength and film thickness of the formed dielectric layer will be insufficient.

As the decomposition promoting substance, a catalyst, a polymerization initiator and a peroxide can be used. Here, it is known that an organic component composed of a polymer such as a resin is decomposed by application of heat, light, or radiation, and its molecular weight is lowered. The decomposition rate of the molecule is further improved. It is known that the decomposition of the main chain of a polymer causes a reaction called a depolymerization reaction, which can be regarded as a reaction opposite to the polymerization reaction. The polymerization reaction and the depolymerization reaction proceed at the same time, and the reaction rates are balanced at the so-called ceiling temperature. Usually, below the ceiling temperature, the polymerization reaction becomes predominant, and the addition of a catalyst thereto lowers the activation energy of the polymerization reaction and further increases the reaction rate. On the other hand, on the higher temperature side than the ceiling temperature,
Since the depolymerization reaction becomes dominant, if the glass paste containing the catalyst is at a temperature higher than the ceiling temperature, the decomposition of the organic component rapidly progresses. As such a catalyst component, C
O, Mn, Zn, Ti, Ni can be mentioned. In particular, Co, Mn, Zn, and Ni are used for those in which organic components are synthesized by polycondensation reaction.
i is used when the organic component is synthesized by an addition polymerization reaction.

For example, of the organic components, a resin will be described as an example. When polymethylmethacrylate (addition polymerization reaction), which is an acrylic resin, is used as the resin, it is selected from Co, Ti, and Ni as decomposition promoting substances. By using the above-mentioned materials and applying a temperature higher than the ceiling temperature (220 ° C.), the decomposition of polymethylmethacrylate progresses more rapidly than in the past, and the monomers can be easily decomposed.

Further, such a catalyst also has a function of lowering the molecular weight of organic components other than the polymer used as a solvent. Here, as the decomposition promoting substance, a polymerization initiator can be used in addition to the catalyst. For example, an acrylic resin is synthesized by a radical polymerization reaction and an anionic polymerization reaction, and a polymerization initiator is used at the start of the polymerization. For the same reason as described above, this polymerization initiator rapidly accelerates the depolymerization reaction at a temperature exceeding the ceiling temperature, and therefore, like the catalyst, can lower the molecular weight of the resin and accelerate the decomposition.

Examples of the radical polymerization reaction initiator include peroxides and azo compounds. In particular,
Benzoyl peroxide, azobisisobutyronitrile, cumene hydroperoxide, tertiary butyl hydroperoxide, persulfate and the like can be used. As the initiator of the anionic polymerization reaction, an alkyllithium catalyst such as n-butyllithium can be used.

Although the decomposition promoting substance has been designed to promote the decomposition of the organic component, a decomposition promoting substance which promotes the oxidation of the organic component to reduce the molecular weight of the organic component may be used. In general, most organic substances promote a combustion reaction, that is, an oxidation reaction, by using a catalyst. The catalyst is suitable as a decomposition-promoting substance because it can promote the oxidation reaction of organic components in a small amount, and is itself chemically stable and does not change by combustion. Further, such a catalyst also has a function of promoting oxidation and burning of organic components other than the polymer used as a solvent.

The decomposition promoting substance for promoting combustion is selected with reference to the following order of combustion reactions (order of strength of combustion) according to the molecular structure of the compound used for the organic component such as resin. be able to. For example, the order of combustion reaction of methane is Pd>Pt> Co ₃ O ₄ >PdO>
Cr ₂ O ₃ > Mn ₂ O ₃ . The order of combustion reaction of propylene is Pt>Pd> Ag ₂ O> Co ₃ O ₄ > CuO.
> MnO ₂ . The order of combustion reaction of carbon monoxide is C
It is oO>NiO> MnO ₂ . Further, by adding an organic component having a functional group containing peroxide or oxygen, oxygen essential for combustion can be supplemented and the decomposition reaction can be promoted.

The ratio of these decomposition promoting substances mixed in the glass paste is preferably 0.
1 to 10 wt%, more preferably 0.5 to 5 wt
%, Most preferably 1 to 3 wt%. this is,
The content of decomposition promoting substance is 0.1wt% to the glass powder.
If it is less than 10%, the lowering of the molecular weight of the organic component may be insufficient, and if it is more than 10% by weight, the color of the decomposition promoting substance may color the front panel. Is.

The glass paste can be prepared by kneading the above-mentioned glass powder, solvent, resin, decomposition accelerating substance and the like using a roll kneader, a mixer, a homomixer or the like. Alternatively, the glass powder and the decomposition accelerating substance are dispersed in a solvent, and the powder and the decomposition accelerating substance are adhered to the particle surfaces of the glass powder by baking and drying the resin and a solvent to form a paste. You can also The glass paste thus prepared has a viscosity of 1 in consideration of ease of application.
-30 Pa · s, more preferably 3-10 Pa · s.

The glass paste thus prepared is applied onto the front glass substrate 102 by using a roller coater, a blade coater or the like, as shown in FIG.
A dielectric layer precursor 104a as shown in (c) is formed. Next, the front panel on which the dielectric layer precursor 104a is formed is fired, and the dielectric layer 1 as shown in FIG.
To form 04.

FIG. 3 (a) is a graph plotting the conventional baking temperature and time, and FIG. 3 (b) is a graph plotting the baking temperature and time according to the present embodiment.
4A to 4C are side views of the front panel in each firing step according to the present embodiment. First, before describing the front panel baking process according to the present embodiment, a conventional front panel baking process will be described.

In the conventional firing of the front panel, as shown in FIG. 3 (a), in the decomposition step, the decomposition of organic components such as resin proceeds at a temperature of about 350 ° C. without melting the glass powder contained in the glass paste. After heating to 10
Hold for about 30 minutes to 30 minutes. As a result, the decomposition of the organic components such as the resin sufficiently progresses, and the decomposed organic components pass through the gaps of the glass powder and are dispersed. If this hold time is insufficient or insufficient, the decomposition of the organic components will not be completed completely, and the undecomposed organic components will be decomposed in the glass melted in the subsequent melting step, and the gas will become bubbles. It may remain in the dielectric layer. Therefore, it is difficult to shorten the hold time in the disassembling step.

On the other hand, the front panel 1 according to the present embodiment
No. 01 dielectric layer precursor 104a contains a decomposition promoting substance. That is, as shown in FIG. 4A, the glass powder 10 is included in the dielectric layer precursor 104a of the front panel.
40, glass powder dispersant 1 which is a mixture of resin and solvent
041 and a decomposition promoting substance 1042 that lowers the molecular weight of the organic component contained in the glass powder dispersant 1041. The decomposition promoting substance 1042 is the glass powder 10
Glass powder dispersant 10 rather than being present inside 40
It is arranged in contact with an organic component such as resin in 41. Therefore, even if the temperature is 350 ° C. or lower, the decomposition rate of the organic component is remarkably increased by the decomposition accelerating substance at a temperature exceeding the ceiling temperature of the organic component such as resin, and the organic component is sufficiently decomposed. .

Therefore, as shown in FIG. 3 (b), in the firing, the holding time of the decomposition step as in the conventional case is unnecessary, or even if the holding time is provided, the time is shortened as compared with the conventional case. be able to. Therefore, the time required for the firing can be shortened as compared with the conventional case. As shown in FIG. 4B, the gas generated by the decomposition of these organic components passes through the glass powders 1040 and is diffused, leaving only the glass powder in the dielectric layer precursor 104a.

Then, in the melting step, the temperature of the residual glass powder is raised to a temperature equal to or higher than its softening point (if the hold time in the decomposition step is unnecessary, the temperature is continuously raised from room temperature to the softening point). By holding from several minutes to several tens of minutes, the glass powder is melted and there is no gap between the powders. By lowering the temperature of this front panel to room temperature, a bubble-free dielectric layer 104 as shown in FIG. 4C is formed.

Then, on the dielectric layer 104, as shown in FIG.
By covering the protective layer 105 made of MgO as shown in (e), the front panel 101 (FIG. 1) is formed. Thus, by using the glass paste containing the decomposition promoting substance for forming the dielectric layer, the firing time can be shortened without generating bubbles in the dielectric layer, that is, without lowering the transmittance of the dielectric layer. be able to. Therefore, in the PDP, the firing time can be shortened without lowering the brightness.

(3) Method for Manufacturing Rear Panel 111 An example of a method for manufacturing the rear panel 111 will be described with reference to FIG. In the rear panel 111, first, a silver paste for an electrode is screen-printed on the rear glass substrate 112 and then baked to form the address electrodes 113 in a row. A glass paste obtained by adding titanium oxide to the same component as that used for forming the dielectric layer 104 of the front panel is applied thereon by using a screen printing method. Then, the visible light reflecting layer 11 is baked by performing the same baking as the above-mentioned baking process of the front panel.
4 is formed. Furthermore, on this visible light reflection layer 114,
A partition 115 is formed by repeatedly applying a paste containing a lead-based glass material at a predetermined pitch using a screen printing method, and then firing the paste. This partition 11
5 forms a discharge space divided into cells (unit light emitting regions) in the x-axis direction. Here, the address electrode 11
3 and the visible light reflection layer 114 may be baked together after printing the partition wall 115.

A paste-like phosphor ink containing red (R), green (G), and blue (B) phosphor particles is repeatedly applied to the grooves between the partition walls 115 in the order of colors. . By baking this at a temperature of 400 to 590 ° C. to burn off the resin in the paste, the phosphor layer 116 formed by binding the respective phosphor particles is formed. (4) Fabrication of PDP by pasting panels together The front panel 101 and the back panel 111 thus fabricated are stacked so that the display electrodes 103 and the address electrodes 113 are orthogonal to each other, and the sealing glass is provided around the panel edges. Is inserted, and this is fired at, for example, about 450 ° C. for 10 to 20 minutes to form an airtight seal layer (not shown) for sealing. Then, after the discharge space is once evacuated to a high vacuum (for example, 1.1 × 10 ⁻⁴ Pa), a discharge gas (for example, a He—Xe-based or Ne—Xe-based inert gas) is kept at a predetermined pressure. By encapsulating P
The DP is created.

In such a PDP, the firing time of the dielectric layer in the front panel can be shortened, so that the manufacturing cost is reduced. (5) Experiment An example sample in which a dielectric layer was formed on a glass substrate was prepared using the glass paste containing each decomposition promoting substance described in the above embodiment, and the transmittance was measured.

Further, Comparative Examples 1 and 2 in which a dielectric layer was formed on a glass substrate were prepared using a glass paste containing no decomposition promoting substance, and the transmittance was measured in the same manner. In addition, each Example sample and Comparative example sample 1
For the firing of the dielectric layer, firing was performed in the firing pattern shown in FIG. In Comparative Example Sample 2, the same dielectric layer precursor as in Comparative Example Sample 1 was applied, and this was baked in the firing pattern shown in FIG. 3A (however, the hold time in the decomposition step was 30 minutes). Firing was performed.

Table 1 shows the types and addition amounts of the glass pastes used in the respective Example samples and Comparative Example samples.
It has been described in.

[0054]

[Table 1]

(Examples 1 to 18) PD200 made by Asahi Glass was formed on the glass substrate by the float method.
Was used. Then, the glass paste used the components shown in Table 1 as the decomposition promoting substance, and the addition amount was also the amount described as a percentage with respect to the powder glass contained in the glass paste. In addition, ethyl cellulose was used as the resin, and the dielectric layer was formed to have a thickness of 30 μm after firing.

(Comparative Example Sample 1) The sample of Comparative Example is different from that of each Example only in that the decomposition promoting substance is not contained. The other composition and firing conditions are the same, and the dielectric layer ( A thickness of 30 μm) was formed. (Comparative Example Sample 2) Using a glass paste having the same composition as in Comparative Example Sample 1 above, firing was performed in a firing pattern in which the hold time of the decomposition step in FIG. Was formed.

(Transmittance Measuring Conditions) As a measuring instrument, a total diffuse transmittance measuring device (CM-35 manufactured by Minolta Co., Ltd.)
00d) was used to measure the total diffused transmittance of the glass substrate on which the dielectric layer was formed. Note that the transmittance of only the glass substrate was measured as a blank, and the total diffused transmittance of only the dielectric layer was measured by subtracting this transmittance from the measurement results. The results are shown in Table 1.

As can be seen from Table 1, Comparative Example Sample 2
And in each of the example samples, the total diffuse transmittance is 8
It is over 3%. From this, it can be seen that the samples of each example according to the present invention maintain the same transmittance as the dielectric layer fired in the conventional firing pattern. On the other hand, the comparative sample 1 has a transmittance of 78%, which is 6% or more lower than that of each example sample.

This is because the glass paste used in Comparative Example Sample 1 does not contain a decomposition promoting substance, so that organic components such as resin remain in the dielectric layer even when the glass powder is melted. It is considered that the bubbles became bubbles in and the transmittance of the dielectric layer was lowered. Furthermore, the height of the partition wall 115 (FIG. 1) is set to 0 in accordance with the PDP (42 inch VGA) in which the dielectric layer is formed under the same manufacturing conditions as those of the above-described example samples 1 to 18 and comparative example samples 1 and 2. ．
15 mm, the interval between the partition walls 115 (cell pitch) is 0.
36 mm and the distance between the display electrodes 103 was set to 0.1 mm), and the brightness was measured and compared under the same driving conditions. As a result, each Example sample 1-1
8 and PDP having the same dielectric layer as Comparative Sample 2
Was about 5% higher in brightness than the PDP having the dielectric layer of Comparative Sample 1. From this, it can be seen that by using the glass paste of the present invention, the brightness of the PDP can be secured to the same level as the conventional one. Further, in the range of the addition amount of the decomposition promoting substance shown in Table 1, coloring of the front panel was not observed.

Although ethyl cellulose is used as the resin here, the same effect can be obtained with an acrylic resin. Further, as the decomposition-promoting substance, if it is a compound of a decomposition-promoting substance that does not itself promote the decomposition of the organic component but is changed to a substance that promotes the decomposition of the organic component by heating by firing or the like. Can be used.

(Second Embodiment) In the first embodiment, the glass paste is applied when the dielectric layer in the front panel is formed. In the form, a glass paste is applied to a supporting film in advance and dried to use a transfer film in which a dielectric layer precursor is formed on the supporting film. The PDP according to the second embodiment
Since the configuration is substantially the same as that of the first embodiment except that the method of forming the dielectric layer is different, the method of forming the dielectric layer will be mainly described.

FIGS. 5A to 5E are side views of the front panel in each manufacturing process of the front panel. Similar to the first embodiment, the front glass substrate shown in FIG. 5A is prepared, and as shown in FIG. 5B, the display electrodes 203 are provided on the front glass substrate 202 by the thick film method or the thin film method. Line up with.

Next, the transfer film 204a from which the cover film has been removed is pressed onto the front glass substrate 202 on which the display electrodes 203 are arranged. Here, the transfer film 204a is, as shown in FIG.
04b and dielectric layer precursor 2 obtained by drying glass paste
04c and a cover film (not shown), and the dielectric layer precursor 204c is sandwiched between the support film 204b and the cover film. For this reason,
Dust is less likely to adhere to the dielectric layer precursor 204c.

The support film 204b is preferably made of a resin having heat resistance and solvent resistance to the solvent contained in the glass paste and having flexibility.
Specifically, a film (thickness 20 to 100 μm) made of polyethylene, polypropylene, polystyrene, polyimide, polyvinyl alcohol, polyvinyl chloride or the like can be used.

A glass paste having the same composition as in the first embodiment is uniformly applied to the support film 204b using a roll coater, a blade coater such as a doctor blade, a curtain coater, a wire coater or a fountain coater. After applying a glass paste having a different thickness, it is dried for about 0.1 to 30 minutes while maintaining a temperature of 40 to 150 ° C. to form a dielectric layer precursor 204c. The amount of residual solvent in the dielectric layer precursor 204c is usually 10 wt% or less,
In order to secure the adhesiveness and shape-retaining property required for the close contact with the front glass substrate 202, about 1 to 5 wt% is preferable.

Then, a cover sheet having the same composition and thickness as the support film 204b is pressure-bonded onto the dielectric layer precursor 204c to transfer the transfer film 20.
4a is formed. Since the support film 204b and the cover sheet have flexibility, the transfer film 2
04a can be rolled and stored compactly.

Transfer film 204 formed in this way
a is the front glass substrate 2 after the cover sheet is peeled off.
02 is pressure-bonded while applying heat. Then, by peeling the support film 204b, the display electrode 203
Only the dielectric layer precursor 204c is coated on the front glass substrate 202 on which is formed. Here, in order to facilitate the peeling of the cover sheet and the support film 204b, it is preferable that the surfaces of these are subjected to a release treatment.

As described above, the front glass substrate 202 coated with the dielectric layer precursor 204c is fired in the same temperature pattern as the firing pattern in the first embodiment, and as shown in FIG. The dielectric layer 204 is formed. FIG. 6A to FIG. 6C show the dielectric layer precursor 204.
It is a side view of a front panel which shows a situation at the time of baking of c.

As shown in FIG. 6A, in the dielectric layer precursor 204c, the glass powder 2040 and a glass powder dispersion made of a mixture containing a resin and a solvent are dispersed in the same manner as the glass paste in the first embodiment. Agent 2041 and decomposition-promoting substance 204 that lowers the molecular weight of organic components such as resins and decomposes them
2 is included. By firing this in a temperature rising pattern as shown in FIG. 3B, the decomposition accelerating substance 2042 comes into contact with the organic component such as resin at an initial stage, that is, from the ceiling temperature to about 350 ° C. Completely decomposes the organic components such as resin while rapidly lowering the molecular weight. The decomposed gas is volatilized and diffused while passing through the gap of the glass powder 2040. Therefore, it is not necessary to secure the hold time in the decomposition step of the organic component as in the conventional case, and the organic component has almost completely disappeared when the glass powder 2040 softens. Then, by further raising the temperature and holding it at a temperature near the softening point of the glass powder 2040, the powder is melted and the gaps between the powders are filled, so that FIG.
The dielectric layer 204 is formed as shown in FIG. At this point, since the organic component contained in the dielectric layer precursor 204c has disappeared, no bubbles are generated in the dielectric layer 204. By slowly cooling this front panel, a solidified dielectric layer 204 is formed on the front glass substrate 202.

Finally, as shown in FIG. 5E, a front panel is formed by covering the dielectric layer 204 with a protective layer. As described above, even when the transfer film is used to form the dielectric layer 204, it is possible to shorten the firing time without generating bubbles in the dielectric layer 204, as in the first embodiment. it can.

[0071]

As described above, by using the glass paste and the transfer film of the present invention for forming the dielectric layer on the front panel side in the PDP, the bubbles that reduce the transmittance of the front panel are formed. Therefore, the firing time of the dielectric layer can be shortened.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a part of a PDP.

FIG. 2 is a side view of the front panel in each manufacturing process of the front panel.

FIG. 3A is a graph showing a baking temperature pattern of a conventional front panel. (B) It is a graph which shows the baking temperature pattern of the front panel concerning 1st Embodiment.

FIG. 4 is a side view of the front panel at each stage during firing.

FIG. 5 is a side view of the front panel in each manufacturing process of the front panel according to the second embodiment.

FIG. 6 is a side view of the front panel in each manufacturing process of the front panel according to the second embodiment.

FIG. 7 is a sectional view of a front panel of a conventional PDP.

[Explanation of symbols]

101 front panel 102,202 Front glass substrate 103, 203 display electrodes 104,204 Dielectric layer 104a, 204c Dielectric layer precursor 105 protective layer 111 rear panel 112 Rear glass substrate 113 address electrodes 204a transfer film 204b support film 1040 glass powder 1041 dispersant 1042 Decomposition accelerator

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masaki Aoki             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Keisuke Sumita             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Hideki Ashida             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Junichi Hibino             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 4G062 AA08 AA09 AA15 BB01 CC01                       DA02 DC02 DE02 DF02 MM05                       MM07 MM25 NN26 PP01 PP12                 5C027 AA05 AA10                 5C040 FA01 FA04 GB03 GB14 GD07                       GD09 GD10 JA09 JA22 KA08                       KA14 KB24 MA26 MA30

Claims (26)

[Claims] 1. A glass paste as a starting material for a transparent dielectric material formed on a plasma display panel, comprising a glass powder and an organic component, and a glass powder dispersant for dispersing the glass powder, and the organic material. A glass paste comprising a decomposition promoting substance that promotes decomposition of a component, wherein the decomposition promoting substance is present in a region in contact with the organic component. 2. The decomposition promoting substance is a catalyst for promoting a decomposition reaction of the organic component.
The glass paste described in 1. 3. The catalyst is Co, Mn, Zn, Ti,
The glass paste according to claim 2, which is a substance selected from at least one of Ni. 4. The organic component contains a resin serving as a binder, and the decomposition promoting substance is a polymerization initiator capable of promoting an initiation reaction when polymerizing the raw material of the resin. The glass paste according to claim 1, characterized in that 5. The glass paste according to claim 4, wherein the polymerization initiator is a radical polymerization initiator. 6. The glass paste according to claim 5, wherein the radical polymerization initiator is a peroxide or an azo compound. 7. The peroxide or azo compound is a substance selected from at least one of benzoyl peroxide, azobisisobutyronitrile, cumene hydroperoxide, tertiary butyl hydroperoxide, and persulfate. It exists, The glass paste of Claim 6 characterized by the above-mentioned. 8. The glass paste according to claim 4, wherein the polymerization initiator is an anionic polymerization initiator. 9. The glass paste according to claim 8, wherein the anionic polymerization initiator is an alkyllithium catalyst. 10. The glass paste according to claim 1, wherein the decomposition promoting substance is a catalyst that promotes the oxidation of the organic component. 11. The catalyst is Pd, Pt, Co ₃ O ₄ ,
PdO, Cr ₂ O ₃ , Mn ₂ O ₃ , Ag ₂ O, CuO, Mn
The glass paste according to claim 10, which is a substance selected from at least one of O ₂ , CoO, and NiO. 12. A support film, which is used for forming a transparent dielectric formed on a plasma display panel,
A transfer film comprising a dielectric layer precursor coated on the support film, wherein the dielectric layer precursor is glass powder, an organic component, and a decomposition promoting substance that promotes decomposition of the organic component. The transfer film, wherein the decomposition promoting substance is present in a region in contact with the organic component. 13. The transfer film according to claim 12, wherein the decomposition promoting substance is a catalyst that promotes a decomposition reaction of the organic component. 14. The catalyst is Co, Mn, Zn, T.
The transfer film according to claim 13, wherein the transfer film is a substance selected from at least one of i and Ni. 15. The organic component contains a resin serving as a binder, and the decomposition promoting substance is a polymerization initiator capable of promoting an initiation reaction when polymerizing the raw material of the resin. The transfer film according to claim 12, wherein: 16. The transfer film according to claim 15, wherein the polymerization initiator is a radical polymerization initiator. 17. The transfer film according to claim 16, wherein the radical polymerization initiator is a peroxide or an azo compound. 18. The peroxide or azo compound is a substance selected from at least one of benzoyl peroxide, azobisisobutyronitrile, cumene hydroperoxide, tertiary butyl hydroperoxide, and persulfate. The transfer film according to claim 17, wherein the transfer film is present. 19. The transfer film according to claim 15, wherein the polymerization initiator is an anionic polymerization initiator. 20. The transfer film according to claim 19, wherein the anionic polymerization initiator is an alkyllithium catalyst. 21. The decomposition promoting substance is a catalyst for promoting the oxidation of the organic component.
The transfer film according to. 22. The catalyst is Pd, Pt, Co ₃ O ₄ ,
PdO, Cr ₂ O ₃ , Mn ₂ O ₃ , Ag ₂ O, CuO, Mn
The transfer film according to claim 21, wherein the transfer film is a substance selected from at least one of O ₂ , CoO, and NiO. 23. A dielectric layer precursor is coated by coating a glass paste on a front glass substrate and drying,
A method of manufacturing a plasma display panel, wherein a dielectric layer is formed on the front glass substrate by firing it, when applying a glass paste to the front glass substrate,
A method for manufacturing a plasma display panel, which comprises applying the glass paste according to claim 1. 24. The method of manufacturing a plasma display panel according to claim 23, wherein in the firing of the dielectric layer precursor, the firing temperature is continuously raised to the softening point of the glass contained in the glass paste. 25. A front glass substrate on which a plurality of pairs of display electrodes are arranged and a dielectric layer covering the display electrodes, and a back surface arranged opposite to the side of the front glass substrate on which the display electrodes are arranged. It is a plasma display panel provided with a glass substrate, Comprising: The said dielectric material layer is formed by baking glass paste, The said glass paste is 1-11.
A plasma display panel comprising the glass paste according to any one of 1. 26. A front glass substrate on which a plurality of pairs of display electrodes are arranged and a dielectric layer covering the display electrodes is arranged, and a back surface arranged opposite to the side of the front glass substrate on which the display electrodes are arranged. A plasma display panel comprising a glass substrate, wherein the dielectric layer is formed by firing a dielectric layer precursor transferred from the transfer film according to claim 12. Plasma display panel characterized by.