JP2002025341A - Dielectric paste, display member using dielectric paste, and display - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a plasma display with improved luminous efficiency by preventing a dielectric layer from becoming yellow caused by a generation of silver colloid due to the progress of reductive reaction and coagulation of the electrode composing silver which is ionized and dispersed into the dielectric layer. SOLUTION: There are provided a dielectric paste used for manufacture of the display member containing at least glass with low melting point and oxidizing agent, and it is used for the display member, and the display.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a dielectric paste, a display member using the same, a display, and a method of manufacturing a display member.

[0002]

2. Description of the Related Art A light and thin flat display is attracting attention as an image forming apparatus replacing a large and heavy cathode ray tube. Liquid crystal displays have been actively developed as flat displays, but problems such as dark images and narrow viewing angles remain. As an alternative to this liquid crystal display, an image forming apparatus using a plasma display panel or an electron-emitting device, which is a self-luminous display, can obtain a brighter image than a liquid crystal display, and has a wider viewing angle, a larger screen, The need for high definition is increasing, and the need is increasing.

The electron-emitting devices include a thermionic electron-emitting device and a cold cathode electron-emitting device. The cold cathode electron-emitting devices include a field emission type (FE type), a metal / insulating layer / metal type (MIM type), and a surface conduction type. An image forming apparatus using such a cold cathode electron source displays an image by irradiating a phosphor with an electron beam emitted from each type of electron-emitting device to generate fluorescent light. In this device, the front glass substrate and the rear glass substrate are used with their respective functions. The rear glass substrate is provided with a plurality of electron-emitting devices and a matrix-like wiring for connecting the electrodes of those devices. Since these wirings intersect at the electrode portion of the electron-emitting device, a dielectric layer for insulation is provided. Further, a partition is formed between the two substrates as an anti-atmospheric pressure support member.

In the case of a plasma display panel, a plasma discharge is generated between a display electrode and an address electrode facing each other in a discharge space provided between a front plate and a rear plate provided with respective functions, and the discharge space is formed in the discharge space. The display is performed by irradiating the ultraviolet rays generated from the gas sealed in the discharge space on the phosphor in the discharge space. Electrodes are formed on the front plate and the rear plate, respectively, and a dielectric layer is formed so as to cover them. Further, the rear glass substrate is provided with a partition wall in order to suppress the spread of the discharge to a certain area, perform the display in a specified cell, and secure a uniform discharge space.

The dielectric layer formed on the glass substrate of the back plate can be roughly divided into (1) a protective layer for electrodes, (2) accumulation of surface charges required for discharge, (3) support of partition walls, and (4) reflection. The layer plays four roles.

Usually, this dielectric layer is made of an inorganic compound mainly composed of glass designed to satisfy each condition. However, in the baking step of the plasma display manufacturing process, the diffusion of silver used for the electrode material may cause the dielectric layer to turn yellow, thereby lowering the reflectance of visible light emitted by the phosphor. However, there is a problem that the luminous efficiency of the plasma display is reduced. In addition, since the reflectance of the dielectric layer greatly differs depending on the wavelength, there is a problem that the color purity of the plasma display deteriorates. The problem of yellowing of the glass when silver is used as an electrode is known from the coloring of a rear window glass having a defroster function of an automobile described in Japanese Utility Model Publication No. 6-34341. As a countermeasure, a method has been proposed in which a ceramic layer is formed between a silver electrode and a glass substrate to prevent silver from diffusing into the glass substrate.

[0007]

However, when a ceramic layer is provided between a silver electrode and a dielectric layer by using this method, not only the number of steps is increased, but also a high-precision flatness like a plasma display is required. However, there is a problem that it is not suitable for a glass substrate used for a display that requires the above.

Accordingly, an object of the present invention is to prevent the yellowing of a dielectric layer due to silver diffused from a silver electrode while maintaining the flatness of a glass substrate without increasing the number of steps in a display manufacturing process. It is an object of the present invention to improve the luminous efficiency and color purity of a liquid crystal and to provide a display with excellent display characteristics.

[0009]

In order to solve the above problems, the present invention has the following arrangement. That is, the dielectric paste of the present invention is characterized by containing at least a low-melting glass and an oxidizing agent.

A display member according to the present invention is characterized in that it is manufactured by using the above-mentioned dielectric paste or that the dielectric layer contains a manganese compound and / or a chromic acid compound.

Further, a display according to the present invention is characterized by using the above-mentioned display member.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below using a plasma display as an example.
However, the present invention is not limited to this, and is preferably applied to a plasma addressed liquid crystal display and a display using an electron-emitting device or an organic electroluminescent device.

The substrate of the back plate of the plasma display is usually made of soda glass or Asahi Glass "PD-20".
It is manufactured using a glass substrate with a high strain point such as 0 ″. An electrode is formed on the glass substrate with a metal such as silver, copper, chromium, aluminum, nickel, and gold.
Here, it is preferable to use silver from the viewpoint of a metal having low resistance, which can be baked on a glass substrate at a temperature of 600 ° C. or lower. The electrodes are usually formed in a stripe shape having a width of 20 to 200 μm, and may be formed by pattern printing a silver paste containing silver powder and an organic binder as main components by screen printing or a photosensitive method using an organic binder as a photosensitive material. A photosensitive silver paste using an organic component is applied, pattern exposure is performed using a photomask, unnecessary portions are dissolved and removed in a development process, and the electrode is formed by heating and baking at 400 to 600 ° C. The conductive paste method can also be used.

The dielectric layer is usually formed at a temperature of 400 to 600 ° C. after applying a glass paste formed by kneading a pigment, a glass powder, an organic binder and the like on a substrate on which electrodes are formed.
It is formed by firing. The thickness of the dielectric layer is 4
~ 20 µm is preferred.

In order to form such a dielectric layer, the dielectric paste of the present invention needs to contain at least a low-melting glass and an oxidizing agent. In other words, by using such a dielectric paste for forming a dielectric layer of a display member, silver constituting an electrode formed on a glass substrate in a baking process is ionized and diffused into the dielectric layer, thereby causing a reduction reaction. In addition, it is possible to prevent the dielectric layer from yellowing, which is caused by the formation of silver colloid by agglomeration.

The low melting point glass used in the present invention is a glass transition point of 400 to 550 ° C. and a softening point of 450 to 600.
It means the glass of ° C. The glass transition point of the low melting glass is 550 ° C. or less, and the softening point is 600 ° C. or less.
No high-temperature firing is required, and no distortion occurs in the glass substrate during firing. Further, since the glass transition point is 400 ° C. or more and the softening point is 450 ° C. or more, no distortion occurs in the dielectric layer at the time of forming or sealing the phosphor layer in a later step,
Film thickness accuracy can be maintained.

Here, the low-melting glass has a composition of 10 to 85 parts by weight of bismuth oxide, 3 to 50 parts by weight of silicon oxide, 5 to 40 parts by weight of boron oxide and 4 to 40 parts by weight of zinc oxide in terms of oxide. Are preferred. Within this composition range, the dielectric layer can be baked on a glass substrate at a firing temperature of 520 to 590 ° C.

Bismuth oxide in the low melting glass powder is 1
It is preferred to be blended in the range of 0 to 85 parts by weight. 1
When the content is 0 parts by weight or more, the effect of controlling the baking temperature and the softening point appears. By setting the content to 85 parts by weight or less, the heat resistance temperature of the glass is prevented from being too low, so that the baking onto the glass substrate is properly performed.

The silicon oxide is preferably blended in the range of 3 to 50 parts by weight. By setting it to 3 parts by weight or more,
The denseness, strength and stability of the glass layer are improved, and the coefficient of thermal expansion becomes close to the value of the glass substrate, so that mismatching with the glass substrate can be prevented. By setting the content to 50 parts by weight or less, the softening point and the glass transition point are reduced, and the resin can be densely baked on a glass substrate at 580 ° C. or less.

It is preferable that boron oxide is blended in the range of 5 to 40 parts by weight. When the content is 5 parts by weight or more, electrical, mechanical, and thermal properties such as electrical insulation, strength, thermal expansion coefficient, and compactness can be improved. 40
When the amount is not more than part by weight, the stability of the glass can be maintained.

The zinc oxide is preferably added in the range of 4 to 40 parts by weight. When the content is 4 parts by weight or more, the effect of improving the denseness is exhibited, and when the content is 40 parts by weight or less, it is possible to prevent the baking temperature from becoming too low to be uncontrollable and to maintain the insulation resistance.

Further, even when glass containing 10 to 80 parts by weight of lead oxide is used, a dielectric layer having excellent stability can be formed in the same manner as when bismuth oxide is used. For example, it is preferable to use one having the following composition. Lead oxide 10 to 85 parts by weight Silicon oxide 3 to 50 parts by weight Boron oxide 5 to 40 parts by weight Zinc oxide 4 to 40 parts by weight Generally, the above glass component preferably does not contain a large amount of alkali metal. This is because, when an alkali metal is contained, a large amount of non-crosslinked oxygen is present in the glass, and the non-crosslinked oxygen causes yellowing of the dielectric layer due to reduction of silver ions diffused from the silver electrode. To do that. Specifically, the total content of alkali metals in the glass component is 5.0 parts by weight or less, preferably 3.
It means less than 0 parts by weight. However, by using a dielectric paste containing the oxidizing agent of the present invention, the degree of yellowing of the dielectric layer can be suppressed even when a glass powder containing a small amount of an alkali metal is used. For this reason, by using the dielectric paste of the present invention, restrictions on the glass powder that can be used for the dielectric layer are reduced.

The low melting point glass powder used in the present invention preferably has an average particle size of 1 to 4 μm. Here, the average particle size is a 50% volume particle size.

The oxidizing agent in the present invention preferably contains an inorganic oxidizing agent. This is because the inorganic oxidizing agent tends to be hardly burned even when firing the dielectric layer. Examples of the inorganic oxidizing agent include manganese compounds such as potassium permanganate, sodium permanganate, potassium manganate, sodium manganate, manganese dioxide, manganese oxide, manganese sulfate, manganese acetate, potassium dichromate, sodium dichromate, and chromium. Chromic acid compounds such as potassium oxide, sodium chromate and chromium oxide; lead compounds such as lead oxide and lead tetraacetate; mercury compounds such as mercury oxide and mercury acetate; and osmium tetroxide;
Ruthenium tetroxide and selenium dioxide. Among them, it is preferable to use a manganese compound and a chromic acid compound in consideration of environmental aspects and the like.

By the oxidizing agent represented by these, in the firing step of the dielectric layer, the reduction of silver ions diffused into the dielectric layer by changing the valence is suppressed and the yellowing of the dielectric layer is prevented. can do. From this viewpoint, among the above-mentioned manganese compounds, potassium permanganate, manganese dioxide, manganese sulfate, manganese acetate and the like can be preferably used. As the chromic acid compound, potassium dichromate, chromium oxide and the like can be preferably used.

In the present invention, these oxidizing agents can be used not only alone but also in combination in a dielectric paste or a dielectric layer. From the viewpoint, it is particularly preferable to include both a manganese compound and a chromic acid compound.

The content of the oxidizing agent in the dielectric paste of the present invention is preferably 0.01 to 5 parts by weight based on 100 parts by weight of the low melting point glass. When the amount is more than 0.01 parts by weight, reduction of silver ions diffused into the dielectric layer can be prevented, and yellowing can be more effectively prevented. In addition, manganese oxide, chromium oxide, and the like remain in the dielectric as a reaction residue of the oxidizing agent, but if the amount is less than 5 parts by weight, the coloring of the dielectric layer due to the reaction residue of the oxidizing agent is reduced. Can be further prevented. Furthermore, the content of the oxidizing agent in the dielectric layer is 0.05 to
More preferably, the amount is 3 parts by weight, and it is possible to effectively prevent yellowing due to silver in the dielectric layer and coloring due to a reaction residue of the oxidizing agent, thereby improving the luminous efficiency of the plasma display. Tend. More preferably, it is 0.1 to 1 part by weight.

To evaluate the yellowness of the dielectric layer, L *
b * value (JIS-Z-8) representing the yellowness of the a * b * color system
729) can be measured. As the dielectric layer,
It is preferable that the b * value representing the yellowness is in the range of -5 to 15. By satisfying the range of −5 to 15, the absorption of visible light generated from the phosphor can be suppressed, so that the luminous efficiency of the plasma display does not decrease.
In addition, it is possible to prevent variations in absorption intensity depending on the wavelength, and it is also possible to suppress a decrease in color purity of the plasma display. More preferably, it is -2 to 10.

Further, the dielectric paste of the present invention preferably further contains a filler. The filler has the effect of reducing the shrinkage of the dielectric layer at the time of firing and reducing the stress applied to the substrate, but such filler is preferably a high melting point glass powder having a softening point of 650 to 850 ° C. , Titania, alumina, silica, cordierite, mullite, spinel, barium titanate and zirconia. Among them, alumina, titania and silica are particularly preferably used. In the case of the back plate of a plasma display, a high reflectance is required for the dielectric layer to reflect visible light generated from the phosphor and improve the luminance. From that point, it is particularly preferable to use titanium oxide, which is a white pigment, as one kind of filler.

By properly selecting these fillers or using them in combination, it is possible to control the dielectric properties such as the dielectric constant and the reflectance of the dielectric layer, and it is possible to control the width of the address electrode and the fluorescent layer. It is easy to optimize the thickness for back plates with different thicknesses.

Here, the amount of the filler added is preferably at least 5 parts by weight. By setting the content to 5% by weight, the effect of reducing the firing shrinkage and controlling the coefficient of thermal expansion becomes higher. Further, by setting the filler addition amount to 50 parts by weight or less, it is possible to maintain the denseness and strength of the dielectric layer after firing, and at the same time, it is possible to further prevent defects such as cracks.

The dielectric paste has a form in which an inorganic component is mixed and dispersed in an organic component composed of a low melting point glass powder and a filler, and the inorganic powder is uniformly mixed and dispersed in the organic component. Is preferred for good coating properties. Further, in consideration of the binder removal property during firing, it is preferable that the sintering of the entire dielectric coating film proceeds at a uniform speed. In order to obtain such a paste, it is preferable that the relationship between the average particle size, the maximum particle size, and the tap density of the inorganic powder, particularly the relationship between the average particle size of the low-melting glass powder and the average particle size of the filler be within an appropriate range.

The average particle size of the inorganic powder is 0.05 to 4 μm,
Maximum particle size is 10μm or less and tap density is 0.6g
/ Cm ³ . Particles having such a range of particle size and its distribution, and powder mass per unit volume have good filling and dispersibility into the paste, and therefore a paste having excellent coatability can be prepared, so that it is dense and uniform. It is possible to obtain a suitable coating film. Since the cohesive force of the particles depends on the surface area, the average particle size is 0.05
When the thickness is at least μm, the cohesiveness is suppressed, the dispersibility in the paste is improved, and a dense and uniform coating film can be obtained. Further, by setting the thickness to 4.0 μm or less, the denseness of the formed dielectric paste coating film is improved, and bubbles and the like are hardly generated inside. Further, unnecessary unevenness does not occur on the surface of the coating film. It is also necessary for the maximum particle size to be 10 μm or less in order to prevent the generation of bubbles inside and the generation of unnecessary irregularities on the surface.

Further, the tap density of the inorganic powder is set to 0.6 g /
cm ³ or more, preferably 0.7 g / cm ³ or more,
The filling and dispersing properties of the powder are improved, and bubbles and aggregates are less likely to be generated. The thickness of the dielectric layer is 4 to 30 μm after firing.
m, more preferably 5 to 20 μm, in order to form a uniform and dense dielectric layer. 30 thickness
When the thickness is not more than μm, the binder removal property at the time of firing becomes good, and cracks due to the remaining binder do not occur. In addition, since the stress applied to the glass substrate is reduced, there is no problem such as warpage of the substrate. In addition, when the thickness is 4 μm or more, a uniform, dense dielectric layer can be formed with flatness, and problems such as cracks in the dielectric layer due to unevenness of the electrode portion do not occur.

Further, the dielectric paste of the present invention preferably contains the conductive powder in an amount of 0.5 to 10 parts by weight of the inorganic component. In an AC plasma display panel, when a plasma discharge is caused between a display electrode and an address electrode, space charges are generated, and most of the space charges are accumulated on a dielectric layer formed on the display electrode. Discharge occurs accidentally by the voltage due to the accumulated electric charges, which causes a problem of deteriorating image quality. In order to eliminate the accumulation of electric charges which causes the deterioration of the image quality, it is effective to mix conductive powder in the dielectric layer to leak the accumulated electric charges. Specifically, as the conductive powder, a metal powder selected from chromium or nickel, or a semiconductor in which impurities are mixed in a metal oxide such as indium oxide, tin oxide, or titanium oxide can be used. The amount of the conductive powder to be added is preferably 0.5 to 10 parts by weight. By setting it to 0.5 parts by weight or more,
Electric charges can be effectively leaked, and accidental discharge can be prevented. By setting the content to 10 parts by weight or less, the denseness of the dielectric layer can be maintained.

After applying and drying the dielectric paste on the substrate,
By firing, a dielectric layer is formed, a partition pattern is formed thereon, and firing is performed again to form a partition. Alternatively, it is possible to form a partition pattern on a coating film obtained by applying and drying a dielectric paste on a substrate, and simultaneously sinter the dielectric paste coating film and the partition pattern. It is possible to shorten the stroke, which is preferable.

When the dielectric layer and the partition are separately fired sequentially, the organic components include cellulose compounds such as ethyl cellulose and methyl cellulose, methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, methyl acrylate, ethyl acrylate, and isobutyl acrylate. Acrylic compound can be used. Further, additives such as a solvent and a plasticizer may be added to the glass paste. As the solvent, general-purpose solvents such as terpineol, butyl lactone, toluene, methyl cellosolve, butyl carbitol acetate, and the like can be used. Also, as a plasticizer, dibutyl phthalate,
Diethyl phthalate or the like can be used. Also,
In the case of simultaneous firing, it is preferable to apply heat to the applied film after applying the dielectric paste on the substrate. The curing of the dielectric paste coating film by heat is performed by sandblasting or photosensitive paste method, and in a process for forming partition walls, erosion by sandblasting abrasives, by solvent during development in photosensitive paste method. It is necessary to withstand the stress caused by the shrinkage of the applied film of the paste for forming the partition and the partition wall or the partition wall pattern, and to realize simultaneous firing of the dielectric layer and the partition wall with high yield.

The dielectric paste having such characteristics can be preferably achieved, for example, by including a thermal polymerization initiator and an organic component having an unsaturated bond in the dielectric paste. As a result, the polymerization or crosslinking reaction proceeds by the chain of the unsaturated bond cleavage reaction, and the molecular structure of the dielectric paste coating film can be changed to a three-dimensional network structure.

The thermal polymerization initiator becomes an active radical by, for example, heat, and can initiate a cleavage reaction of an unsaturated bond such as a carbon-carbon double bond. In order to introduce an organic component having an unsaturated bond, for example, it is preferable to add a monomer having a carbon-carbon double bond, and a method such as introducing a side chain having a carbon-carbon double bond into a polymer. It is also preferable to use For example, when using an acrylic resin, it is preferable to use a homo- or copolymer of acrylic acid or alkyl acrylates and methacrylic acid or alkyl methacrylate, and to select the properties so as to give the paste preferable properties. But can be made of polyacrylic acid, polymethacrylic acid, polymethyl acrylate, polyethyl acrylate, polymethyl methacrylate, polyethyl methacrylate, polypropyl methacrylate, polybutyl methacrylate, polyhexyl methacrylate, etc. Copolymers and copolymers obtained by combining monomers constituting these polymers are preferred.

As the binder polymer, in addition to the acrylic polymer having an unsaturated substituent, a cellulose compound represented by ethyl cellulose, methyl cellulose, etc., methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, methyl acrylate, ethyl acrylate, isobutyl acrylate It is also possible to cure the coating film using only the above-mentioned monomers using an acrylic compound such as the above.

For curing the dielectric paste coating film,
It is also effective to add an organic metal compound, an organic silane, or the like and to crosslink by heat.

The patterning of the partition walls of the present invention can be performed by a screen printing method in which paste screen printing is repeated, or by forming a resist on a paste coating film, removing unnecessary portions with an abrasive, and finally stripping the resist. Method, a photosensitive paste method of applying a photosensitive paste, exposing and developing after drying, a press molding method of pressing the paste coating film with a mold, removing the mold and forming a partition pattern, and the like are used. The photosensitive paste method is particularly preferable because the pattern definition can be improved and the process can be simplified. Hereinafter, description will be given in accordance with the procedure of the photosensitive paste method.

The photosensitive paste for partition walls preferably has the following form. The photosensitive organic component forms a pattern by utilizing a change due to a photoreaction generated by absorbing energy used for exposure. There are known a photo-dissolving type (positive type) in which the light-acting portion is dissolved in the solvent and a photo-insolubilizing type (negative type) in which the light-acting portion is insoluble in the solvent. ing. Either one may be used for the photosensitive paste for forming the photosensitive partition walls, but in order to form a solid pattern by mixing with an inorganic component, it is insoluble in a solvent by being photocured by polymerization and crosslinking reaction. It is preferable to use a photosensitive component of the following type.

The photosensitive organic component of the partition paste contains a photosensitive monomer and a photosensitive or non-photosensitive oligomer or polymer as main components, and contains a photopolymerization initiator. As the photosensitive monomer, a compound having an active carbon-carbon double bond is preferable, and monofunctional and polyfunctional compounds having a vinyl group, an allyl group, an acrylate group, a methacrylate group, and an acrylamide group as a functional group are applied. .
In particular, a compound containing 10 to 80 parts by weight of a polyfunctional acrylate compound and / or a polyfunctional methacrylate compound in an organic component is preferable. Various types of compounds have been developed for the polyfunctional acrylate compound and / or the polyfunctional methacrylate compound.
The selection can be made in consideration of the refractive index and the like.

As a photosensitive organic component, an oligomer or a polymer is used as a component that functions to improve the physical properties of a cured product formed by photoreaction, adjust the viscosity of a paste, and to control the developability of an unexposed portion. Is added. As these oligomers or polymers, those having a carbon chain skeleton obtained by polymerization or copolymerization of components selected from compounds having a carbon-carbon double bond are preferred. In particular, a weight average molecular weight of 2000 to 60,000 having a carboxyl group and an unsaturated double bond in the molecular side chain,
More preferably, 3000 to 40,000 oligomers or polymers are used. To introduce an unsaturated double bond, an oligomer or polymer having a carboxyl group in the side chain may be added to an ethylenic polymer having a glycidyl group or isocyanate group. It is preferable to carry out an addition reaction with an unsaturated compound, acrylic acid chloride, methacrylic acid chloride or allyl chloride. The number of ethylenically unsaturated groups can be appropriately selected depending on reaction conditions. The acid value of the oligomer or polymer is preferably from 50 to 160, particularly preferably from 70 to 140, from the viewpoint of the development allowance and the solubility of the unexposed portion in the developing solution.

In order to initiate a photoreaction by exposure, a photopolymerization initiator is preferably added. In the present invention, the functional groups of the photosensitive monomer, the photosensitive oligomer, and the photosensitive polymer are radically polymerizable in many cases. In this case, the photopolymerization initiator is selected from those which generate a radical species. In some cases, a sensitizer may be added to assist the effect of the photopolymerization initiator.

The thermal characteristics of the inorganic powder contained in the photosensitive paste for forming the partition walls are preferably similar to the thermal characteristics of the inorganic powder of the dielectric paste. This is to realize simultaneous firing of the formation of the dielectric layer and the formation of the partition layer without adversely affecting the glass plate serving as the substrate. Also, as described below, 10
In order to expose a high-definition pattern on the barrier rib paste coating film having a thickness of 0 μm or more and form a pattern with a high aspect ratio with high resolution, actinic light for exposure should travel as straight as possible to the bottom of the coating film. Preferably, it is transmitted. For this reason, it is preferable that an inorganic powder to be mixed with the photosensitive paste for forming a partition wall has a high light transmittance, and that the average refractive index is close to that of the photosensitive organic component.

The composition of the inorganic powder of the photosensitive paste for forming a partition wall is not limited to this, but it is preferable that the inorganic paste is composed of a glass powder having the following composition. That is, in terms of oxide, it has a composition of lithium oxide 3 to 15 parts by weight silicon oxide 10 to 30 parts by weight boron oxide 20 to 40 parts by weight barium oxide 2 to 15 parts by weight aluminum oxide 10 to 25 parts by weight .

Improvement of the shape retention and accuracy of the partition pattern;
It is preferable to add 10 to 50 parts by weight of a filler to the inorganic powder in order to reduce the firing shrinkage rate when forming the partition walls. By adding 10 parts by weight or more of the filler in the inorganic powder composed of the glass powder and the filler, it is possible to lower the firing shrinkage or control the coefficient of thermal expansion, thereby improving the shape retention and accuracy of the partition walls. . Further, addition of a filler is preferable in maintaining the strength of the obtained partition wall. On the other hand, by setting the content of the filler to 50 parts by weight or less,
The denseness of the partition after firing is maintained, the strength of the partition is maintained, and defects such as peeling or falling off can be prevented. Further, it is possible to prevent the adsorption of a trace amount of water and the retention of organic components in the partition walls, thereby preventing the deterioration of discharge characteristics. As the filler, at least one selected from the group consisting of titanium oxide, aluminum oxide, zirconium oxide, cordierite, mullite, spinel, and high melting point glass can be preferably used.

As with the dielectric paste, the inorganic powder constituting the photosensitive paste for forming barrier ribs has a preferable appropriate range of the average particle size, the maximum particle size, and the tap density for obtaining good coatability. The average particle size of the inorganic powder is 1.5 to
6 μm, and the maximum particle size is preferably 30 μm or less. By setting the average particle diameter to 1.5 μm or more, aggregation of the powder is suppressed, dispersibility in the paste is improved, a dense coating film can be formed, and a high-definition pattern can be obtained. on the other hand,
By setting the thickness to 6 μm or less, the denseness of the formed partition wall is improved, the mechanical strength can be improved without generating voids and the like, and the degree of vacuum inside is not reduced. . Further, there is no unnecessary unevenness on the surface of the partition wall, and no trouble occurs during sealing. Making the maximum particle size 30 μm or less is also advantageous in preventing mechanical strength and unnecessary irregularities on the surface. Tap density is 0.6
g / cm ³ or more, more preferably 0.7 g / cm ³ or more, improves the filling and dispersibility of the powder, makes it difficult to generate bubbles and agglomerates, has high light transmittance, and has an excellent pattern. A photosensitive paste for forming partition walls exhibiting characteristics can be obtained.

The mixing ratio of the inorganic powder of the photosensitive partition wall forming paste to the photosensitive organic component is 60/40 to 9
0/10 (parts by weight) is preferred. Furthermore, 65 / 35-
It is preferable that the ratio is 85/15 (parts by weight) from the viewpoint of the shrinkage ratio due to firing.

In addition to the above photosensitive organic components and inorganic powder,
If necessary, additives such as an ultraviolet absorber, a polymerization inhibitor, a dispersant, and a stabilizer can be added to the photosensitive paste.

The application of the photosensitive paste can be performed by a general method such as a screen printing method, a bar coater method, a roll coater method, and a doctor blade method. The coating thickness can be determined in consideration of the desired height of the partition and the shrinkage ratio due to baking of the paste. However, the preferable height of the partition after baking is 60 to 170 μm, and the coating is performed in consideration of the baking shrinkage. The thickness of the partition wall paste coating film is 100 to 2
It is preferably 20 μm.

After the photosensitive paste for the partition is applied, it is dried and exposed. The actinic rays used for the exposure are most preferably ultraviolet rays. As the light source, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a halogen lamp and the like are used. An exposure machine using a parallel beam using an ultra-high pressure mercury lamp as a light source is generally used.

After the exposure, development is carried out using the difference in solubility between the exposed part and the unexposed part in the developing solution.
An immersion method, a spray method, a brush method, or the like is used. As the developer, a solution in which an organic component, particularly an oligomer or a polymer, in the photosensitive partition wall paste is preferably used.
Photosensitive or non-photosensitive oligomers or polymers having a carboxyl group in the side chain preferably used in the present invention,
It can be developed with an aqueous alkali solution. The patterning of the partition wall may be performed in consideration of shrinkage due to baking, but the size of the partition wall after baking is 100 to 250 μm in pitch.
m, a height of 60 to 170 μm, and a width of 15 to 60 μm are preferable, and are mainly formed in a stripe shape, but may have a grid shape.

Usually, after the partition pattern is formed, a dielectric paste coating film and a partition pattern which have been previously cured by heat are simultaneously fired to form a dielectric layer and a partition layer. The firing atmosphere and temperature vary depending on the properties of the paste and the substrate, but are usually fired in air. As the firing furnace, a batch-type firing furnace or a belt-type continuous firing furnace can be used. In the case of a batch-type firing furnace, the temperature of the glass substrate on which the partition wall pattern is formed on the dielectric paste coating film is increased from room temperature to about 500 ° C. at a substantially constant speed over several hours, and further set as a firing temperature. 500-580 ° C
For 30 to 40 minutes and hold for 15 to 30 minutes for baking.

The firing temperature is preferably lower than the glass transition point of the glass substrate used. Usually, the firing temperature is 590 ° C
Hereinafter, by setting the baking time to 15 to 30 minutes, a good partition wall without defects such as sagging can be obtained.

A phosphor paste which emits red, green and blue light is applied to the cells sandwiched between the partition walls thus obtained, whereby the back plate of the plasma display panel, that is, the display member can be manufactured.

After bonding the back plate and the front plate,
A plasma display is manufactured by sealing, gas sealing, and mounting a driver IC for driving.

[0060]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to embodiments. However, the present invention is not limited to this. Prior to the description of the embodiments, various measurement methods will be described first. (Method of Measuring Particle Size) The particle size of the powder is a value measured using a particle size distribution analyzer (Microtrack HRA particle size analyzer Model No. 9320-X100) using a laser diffraction scattering method. And take 1 in purified water
Performed with ultrasonic dispersion for ~ 1.5 minutes. Average particle size is 50
The% volume particle size and the maximum particle size are the maximum values of the particle size. (Tap density measurement method) Tap density is JIS Z25
As described in 00, the mass per unit volume of the powder in the vibrated container. In the present invention, TSUTSU
I SCIENTIFIC INSTRUMENTS
Co. A. B. Using D POWER TESTER,
After vibrating the 100 cc container containing the glass powder for 5 minutes, the glass powder was ground and the mass per 100 cc was measured. (B * Measuring Method) In the present invention, b * of the dielectric layer was measured using a Minolta CM-2002 spectrophotometer after forming an electrode pattern, a dielectric layer and a partition pattern. (Brightness Evaluation Method) In the present invention, after the panel is manufactured, the panel is actually turned on, and a luminance meter LS-100 manufactured by Minolta is used.
The measurement was performed under the conditions of a measurement angle of 1 degree and a measurement light beam circle of 31 mm.

Examples 1 to 7, Comparative Example 1 First, a back plate of a plasma display was manufactured. A 42-inch diagonal glass substrate (PD200 manufactured by Asahi Glass Co., Ltd.) was washed, and an address electrode was formed on the surface thereof. The electrodes were formed by a photosensitive paste method. After applying and drying a photosensitive silver paste on the entire surface of the substrate, a desired pattern was exposed to ultraviolet light, unnecessary portions were removed with a developing solution, and firing was performed. In this embodiment, a silver electrode having a stripe pattern with a thickness of 3 μm, a line width of 100 μm, and a pitch of 360 μm was formed.

Next, a dielectric layer was formed on this electrode.
The dielectric pastes of Examples 1 to 7 and Comparative Example 1 consisted of 2 parts by weight of an organic component (ethyl cellulose), 13 parts by weight of a monomer (trimethylolpropane triacrylate), and a polymerization initiator (1-1′-azobis (cyclohexane-1). -Carbonitrile) of 0.1 part by weight and terpineol 20 parts by weight, and the inorganic component of each example was composed of a low-melting glass, a filler, and an oxidizing agent, and the type and amount of addition are shown in Table 1. After applying the dielectric paste by a screen printing method, thermal polymerization was performed at 150 ° C. for 10 minutes.
The concentrations in the examples are parts by weight unless otherwise noted. Composition and properties of low melting glass powder A (Note 1): Lead oxide 38
Parts, silicon oxide 6 parts, boron oxide 20 parts, zinc oxide 20
Parts, 4 parts of aluminum oxide. Glass transition point 445 ° C, softening point 485 ° C, coefficient of thermal expansion 75 × 10 ^-7 / ° C, density 4.
81 g / cm ³ .

These dielectric pastes were applied to the entire surface of the glass substrate with electrodes by screen printing. After applying the dielectric paste, thermal polymerization was performed at 150 ° C. for 10 minutes.

Next, a photosensitive paste for forming a partition was applied by a die coating method on a coating film obtained by thermally polymerizing a dielectric paste film. After drying the photosensitive paste coating film for forming the barrier ribs, the photosensitive paste is dried for 200 m through a stripe-shaped pattern photomask.
After giving an exposure amount of J / cm ² , development was performed with 0.2 parts of an aqueous 2-aminoethanol solution, and the pitch was 220 μm and the line width was 3 μm.
A partition pattern of 0 μm and a height of 160 μm was formed. Thereafter, a firing temperature of 570 using a roller hearth type firing furnace
Firing at 150C for 15 minutes. By measuring the b * value of the dielectric layers formed using the various dielectric pastes shown in Table 1, the yellowness was evaluated, and the results are summarized in Table 1.

A phosphor layer of three colors of red, green and blue was formed on the substrate on which the partition walls were formed, sealed together with the front plate, and gas was injected to produce a panel. With respect to the luminance evaluation, the luminance of the example of the present invention was relatively evaluated with the luminance when the plasma display to which no oxidizing agent was added was lit in white as 100.

[0066]

[Table 1]

In Examples 1 to 7 using a dielectric paste containing an oxidizing agent, the yellowness b * value of the dielectric was set to -5.
As a result, a plasma display with satisfactory luminance was obtained.

In Comparative Example 1, the oxidizing agent was not contained, and the b * value of the dielectric layer was 15 or more, and the luminance was low due to yellowing.

[0069]

According to the present invention, it is possible to provide a dielectric paste, a member for a display, and a display, which suppress yellowing of a dielectric layer and suppress a decrease in luminance due to yellowing.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01J 9/02 H01J 9/02 F 5G303 11/02 11/02 B F term (Reference) 2H025 AA11 AA18 AB20 AC01 AD01 BC31 CC08 CC20 DA20 FA29 4G062 AA08 AA09 AA15 BB01 BB05 DA03 DA04 DA05 DB01 DC03 DC04 DC05 DD01 DE03 DE04 DE05 DF01 EA01 EA10 EB01 EC01 ED01 EE01 EF01 EG01 FA01 FA10 FB01 FC01 FF01 GA01 F01 GA01 F01 GA01 GD01 GE01 HH01 HH03 HH05 HH07 HH09 HH11 HH13 HH15 HH17 HH20 JJ01 JJ03 JJ05 JJ07 JJ10 KK01 KK03 KK05 KK07 KK10 MM07 MM12 NN26 NN32 PP01 PP13 PP15 PP16 5C027 AA06 AA09 5C04 AA09 AA09 5C BA07 CA02 CA03 CA09 CB01 CB02 CB03 CB16 CB30 CB35

Claims (10)

[Claims] 1. A dielectric paste comprising at least a low-melting glass and an oxidizing agent. 2. The glass transition point of the low-melting glass is 400 to 5
The dielectric paste according to claim 1, wherein the dielectric paste has a softening point of 50 to 600C. 3. The dielectric paste according to claim 1, wherein the oxidizing agent contains an inorganic oxidizing agent. 4. The dielectric paste according to claim 1, wherein the oxidizing agent contains a manganese compound and / or a chromic acid compound. 5. The method according to claim 1, wherein the oxidizing agent is contained in an amount of 0.01 to 5 parts by weight per 100 parts by weight of the low melting point glass.
5. The dielectric paste according to any one of items 1 to 4. 6. The dielectric paste according to claim 1, further comprising at least one filler selected from the group consisting of alumina, titania, silica and high melting point glass. 7. A display member comprising the dielectric paste according to any one of claims 1 to 6. 8. The b * value of the L * a * b * color system is -5 to 15.
The display member according to claim 7, further comprising a dielectric layer having a range of: 9. A member for a display, wherein the dielectric layer contains a manganese compound and / or a chromic compound. 10. A display using the display member according to any one of claims 7 to 9.