JP2010086719A - Method of forming photosensitive paste and pattern, and method of manufacturing member for planar display panel - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a photosensitive paste capable of forming a pattern of high strength and high definition. <P>SOLUTION: The photosensitive glass paste is composed of an organic component containing a photosensitive organic component and an inorganic component containing ≥50 mass% of a low softening point glass powder in a total inorganic component, and the inorganic component contains metal hydroxide powder. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a photosensitive paste suitable for forming an insulating pattern used in a flat display such as a plasma display panel, a field emission display, and a fluorescent display tube, a pattern forming method using the same, and a flat display panel member It is related with the manufacturing method.

  In recent years, development of flat displays such as plasma display panels, field emission displays, fluorescent display tubes, liquid crystal display devices, electroluminescence displays, and light emitting diodes has been rapidly advanced. Among these, the plasma display causes plasma discharge between the anode electrode and the cathode electrode facing each other in the discharge space provided between the front glass substrate and the rear glass substrate, and from the gas sealed in the discharge space. Display is performed by irradiating the generated ultraviolet rays to a phosphor provided in the discharge space. A gas discharge type display such as a plasma display or a fluorescent display tube requires an insulating partition for partitioning a discharge space. A field emission display such as a field emission display requires an insulating partition for separating the gate electrode and the cathode. In forming insulating partition walls such as these plasma display panels and field emission displays, materials and processing methods that can pattern an inorganic material such as glass powder with high accuracy are required.

In particular, regarding a plasma display, forming a finer partition wall and securing a wider discharge space is an indispensable technique for increasing the definition and brightness of the plasma display. Conventionally, as a method for performing fine pattern processing of an inorganic material, a method of forming a pattern by a photosensitive paste method has been proposed (for example, Patent Documents 1 to 3). In order to secure a wider discharge space, it is desired that the bottom line width and the top line width are both narrow in the cross-sectional shape of the barrier rib for plasma display. However, since the strength of the partition walls decreases as the width is reduced, the partition walls are chipped during sealing or panel drop test, and non-lighting defects due to the chipping occur. Achieving high strength has been an important issue. Conventionally, the strength of the partition walls has been studied by adding a hard metal oxide such as aluminum oxide. However, many of the hard metal oxides have a large refractive index, and when added to the photosensitive paste, the difference in refractive index from the organic component is large. It was unsuitable for formation.
Japanese Patent No. 3249576 (Claim 1) Japanese Patent No. 3239759 (Claim 1) Japanese Patent No. 3402070 (Claim 1)

  An object of the present invention is to provide a photosensitive paste capable of forming a high-strength and high-definition pattern by paying attention to the above-mentioned problems of the prior art. Another object of the present invention is to stably provide a member for a plasma display panel in which high-strength and high-definition partition walls are formed.

  In order to solve the above problems, the present invention has the following configuration. That is, the present invention is a photosensitive glass paste comprising an organic component containing a photosensitive organic component and an inorganic component containing a low softening point glass powder occupying 50% by volume or more of the total inorganic components, and further contains metallic water in the inorganic component. This is achieved by a photosensitive glass paste characterized in that it contains an oxide powder. The photosensitive paste is achieved by a pattern forming method characterized by at least coating, exposing, developing, and baking.

  According to the present invention, a photosensitive paste capable of forming a high-strength and high-definition pattern can be provided. In addition, it is possible to stably provide a member for a plasma display panel in which a high-strength and high-definition partition is formed.

  The photosensitive paste as used in the present invention means that the irradiated part becomes insoluble in the developer by irradiating the coating film after coating and drying, and then only the non-irradiated part is removed by the developer. This refers to a paste that can be patterned. The actinic rays mentioned here refer to electromagnetic waves in the wavelength region of 250 to 1100 nm, specifically, ultraviolet rays such as ultra-high pressure mercury lamps and metal halide lamps, visible rays such as halogen lamps, helium-cadmium lasers, helium-neon lasers, Specific examples include laser beams having specific wavelengths such as an argon ion laser, a semiconductor laser, a YAG laser, and a carbon dioxide laser.

  As a result of intensive studies on a photosensitive glass paste capable of forming a high-strength and high-definition pattern, the inventors have found that an inorganic component including a low softening point glass powder and a metal hydroxide powder and an organic component including a photosensitive organic component. It was clarified that it can be achieved by photosensitive glass paste consisting of components.

  The photosensitive paste of the present invention contains a low softening point glass powder as an essential component as an inorganic component. By containing the low softening point glass powder, it can be baked at a temperature equal to or higher than the softening temperature of the low softening point glass powder to remove organic components such as a photosensitive organic component described later to obtain a pattern made of an inorganic component. . In the present invention, the low softening point glass powder refers to a glass powder having a load softening temperature in the range of 400 to 600 ° C. This is because when the load softening temperature is within this range, there is no deformation of the pattern during sintering, and the meltability becomes appropriate. A more preferable range of the load softening temperature is 450 to 550 ° C. The load softening temperature can be obtained by a method of JIS-R2209 (2007) using a cylindrical test piece having a diameter of 50 mm and a height of 50 mm. Moreover, the ratio for which the low softening point glass powder accounts to the inorganic component needs to be 50 volume% or more. When the proportion of the low softening point glass powder in the inorganic component is less than 50% by volume, sintering during firing becomes difficult, the porosity of the pattern after firing increases, and the strength decreases. Further, when an opaque inorganic component other than the low softening point glass such as conductive powder is contained, the light transmittance of the paste coating film is lowered, and a good pattern cannot be formed. The proportion of the low softening point glass powder in the inorganic component is preferably 60 to 95% by volume. When the content ratio is less than 60% by volume, sintering during firing becomes difficult, and the porosity of the pattern after firing tends to increase, which is not preferable. If it exceeds 95% by volume, the fluidity of the entire inorganic component at the time of firing is increased, which may cause a problem that it becomes difficult to control the pattern shape after firing, which is not preferable.

The refractive index of the low softening point glass powder is preferably 1.50 to 1.65. By using such a low softening point glass powder, the difference in refractive index between the inorganic component and the organic component is reduced, and light scattering is suppressed, thereby facilitating high-precision pattern processing. The particle size of the low softening point glass powder is selected in consideration of the shape of the pattern to be produced, but 50% particles in the weight distribution curve measured by a particle size distribution measuring device (for example, “MT3300” manufactured by Nikkiso). It is preferable that the diameter d ₅₀ (average particle diameter) is 0.1 to 3.0 μm and the maximum particle diameter d _max (top size) is 10 μm or less.

The low softening point glass powder that can be preferably used has, for example, the following composition in oxide notation.
At least one of lithium oxide, sodium oxide, and potassium oxide: 3 to 15% by mass
Silicon oxide: 5 to 30% by mass
Boron oxide: 20-45% by mass
Zinc oxide: 1-5% by mass
Aluminum oxide: 10-25% by mass
Magnesium oxide and / or calcium oxide: 2 to 15% by mass
Barium oxide and / or strontium oxide: 2 to 15% by mass
As described above, at least one kind of alkali metal oxides of lithium oxide, sodium oxide, or potassium oxide is used, and the total amount is preferably 3 to 15% by mass, and more preferably 3 to 10% by mass. Specifically, lithium oxide 7% by mass, silicon oxide 22% by mass, boron oxide 33% by mass, zinc oxide 3% by mass, aluminum oxide 19% by mass, magnesium oxide 6% by mass, calcium oxide 5% by mass, barium oxide 5 Although it has a composition of mass%, it is not limited to this.

  The photosensitive paste of the present invention contains a metal hydroxide powder as an essential component in addition to the above low softening point glass powder as an inorganic component. In general, metal hydroxides are hardened by releasing water in the firing step to become corresponding metal oxides. Further, since the refractive index of the metal hydroxide is smaller than that of the corresponding metal oxide, the difference in the refractive index from the organic component in the photosensitive paste is not so large, and thus the exposure light scattering is suppressed. Therefore, by adding metal hydroxide powder as a metal oxide precursor to the paste and baking after patterning, the metal oxide having a large refractive index difference from the organic component can be directly added to the photosensitive paste. And a pattern containing a metal oxide can be formed. As the metal hydroxide, aluminum hydroxide, magnesium hydroxide, zirconium hydroxide or the like can be preferably used.

The proportion of the metal hydroxide powder in the inorganic component is preferably 5 to 40% by volume. When the content ratio is smaller than 5% by volume, the pattern strength becomes insufficient, which is not preferable. On the other hand, when the content ratio is larger than 40% by volume, the denseness of the pattern to be formed tends to be lowered, which is not preferable. The particle size of the metal hydroxide powder is selected in consideration of the shape of the pattern to be produced, but the average particle size (d ₅₀ ) is preferably 0.5 to 3.0 μm.

In the present invention, a filler component can be added as an inorganic component in addition to the above low softening point glass powder and metal hydroxide powder. The filler component in the present invention is added to improve pattern strength and firing shrinkage rate, and refers to inorganic fine particles that hardly melt and flow even at the firing temperature. By adding a filler component, the shrinkage | contraction by baking of a pattern can be suppressed or the intensity | strength of a pattern can be improved. The filler component has an average particle diameter (d ₅₀ ) of 1 to 4 μm and an average refractive index of 1.4 to 1.7 in consideration of dispersibility and filling properties in the photosensitive paste and suppression of light scattering during exposure. A thing can be preferably used. In the present invention, as such a filler component, at least one selected from high softening point glass powder having a glass transition temperature of 500 ° C. or higher, ceramic powder such as cordierite, silica, etc. can be used. From the viewpoint of easy adjustment of the average particle diameter and the average refractive index, it is preferable to use a high softening point glass powder.

  When using a high softening point glass powder as a filler component, it is preferable to add a glass transition temperature of 500 to 1200 ° C. in a composition range of 3 to 40% by volume with respect to all inorganic fine particles. When the amount is less than 3% by volume, the edge of the pattern tends to collapse during firing, and a pattern with a good shape may not be obtained. On the other hand, when it is more than 40% by volume, the denseness of the pattern to be formed tends to be lowered, which is not preferable. The high softening point glass powder that can be preferably used is, for example, 1% by mass of sodium oxide, 40% by mass of silicon oxide, 10% by mass of boron oxide, 33% by mass of aluminum oxide, 4% by mass of zinc oxide, 9% by mass of calcium oxide, 3% by mass of titanium oxide. % Composition, but is not limited to this.

  In the present invention, the inorganic component is preferably contained in the solid content of the photosensitive paste at a content of 40 to 65% by volume. Here, solid content means the organic component except the inorganic component contained in a paste, and a solvent. When the content of the inorganic component is less than 40% by volume, the pattern shrinkage due to firing increases, and the shape tends to be poor, which is not preferable. On the other hand, if it exceeds 65% by volume, the crosslinking reaction due to exposure becomes insufficient, and pattern formation becomes difficult.

  The content ratio (volume%) of the inorganic component in the solid content can be controlled by the addition amount (mass%) in consideration of the specific gravity of the inorganic component and the organic component at the time of preparing the paste. In addition, as a method of analyzing the content ratio of the inorganic component, a method of obtaining by thermogravimetry (TGA) and specific gravity measurement of a fired film of the inorganic component, or permeation of a paste dry film obtained by applying and drying a photosensitive paste And a method of obtaining by image analysis of an image observed with a scanning electron microscope. When determining by thermogravimetry and specific gravity measurement of a fired film of an inorganic component, for example, using a photosensitive paste of about 10 mg as a sample, the weight change from room temperature to 600 ° C. is TGA (for example, “TGA-50” manufactured by Shimadzu Corporation). Evaluate by Usually, since the solvent in the paste evaporates at 100 to 150 ° C., the mass ratio of the inorganic component and the organic component is determined from the ratio of the weight after the temperature rise of 600 ° C. to the weight after the solvent evaporation. On the other hand, the content ratio can be evaluated by evaluating the specific gravity of the inorganic component based on the film thickness, area and mass of the fired film. Moreover, when calculating | requiring a content rate by transmission electron microscope observation, the cross section perpendicular | vertical to the film surface of a paste dry film | membrane is observed with a transmission electron microscope (for example, "JEM-4000EX" by JEOL Ltd.), image The image analysis may be performed by distinguishing the inorganic component and the organic component according to the density of the image. As an evaluation area of the transmission electron microscope, for example, an area of about 20 μm × 100 μm is targeted, and observation may be performed at about 1000 to 3000 times.

  The organic component of the present invention includes a photosensitive organic component selected from at least one of a photosensitive monomer, a photosensitive oligomer, and a photosensitive polymer as an essential component, and further includes a non-photosensitive polymer component, an antioxidant, and photopolymerization initiation. It is comprised by adding additive components, such as an agent, a plasticizer, a thickener, a dispersing agent, an organic solvent, and a precipitation inhibitor, as needed.

  As the photosensitive polymer, an alkali-soluble polymer can be preferably used. This is because the polymer is alkali-soluble, so that an aqueous alkaline solution can be used as a developer instead of an organic solvent having a problem with the environment. As the alkali-soluble polymer, an acrylic copolymer can be preferably used. The acrylic copolymer is a copolymer containing at least an acrylic monomer as a copolymerization component. Specific examples of the acrylic monomer include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n -Butyl acrylate, sec-butyl acrylate, isobutyl acrylate, tert-butyl acrylate, n-pentyl acrylate, allyl acrylate, benzyl acrylate, butoxyethyl acrylate, butoxytriethylene glycol acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, di Cyclopentenyl acrylate, 2-ethylhexyl acrylate, glycerol acrylate, glycidyl acrylate, heptadecafluorodecyl acrylate 2-hydroxyethyl acrylate, isobornyl acrylate, 2-hydroxypropyl acrylate, isodecyl acrylate, isooctyl acrylate, lauryl acrylate, 2-methoxyethyl acrylate, methoxyethylene glycol acrylate, methoxydiethylene glycol acrylate, octafluoropentyl acrylate, phenoxy Acrylic monomers such as ethyl acrylate, stearyl acrylate, trifluoroethyl acrylate, acrylamide, aminoethyl acrylate, phenyl acrylate, 1-naphthyl acrylate, 2-naphthyl acrylate, thiophenol acrylate, benzyl mercaptan acrylate, and these acrylates into methacrylates Listed are alternatives It is. As the copolymer component other than the acrylic monomer, a compound having a carbon-carbon double bond can be used, but preferably styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene. , Styrenes such as chloromethylstyrene and hydroxymethylstyrene, 1-vinyl-2-pyrrolidone and the like.

  In order to impart alkali solubility to the acrylic copolymer, it is achieved by adding an unsaturated acid such as an unsaturated carboxylic acid as a monomer. Specific examples of the unsaturated acid include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, vinyl acetate, or acid anhydrides thereof. The acid value of the polymer after adding these is preferably in the range of 50-150.

  In order to increase the reaction rate of the curing reaction by exposure of the acrylic copolymer, it is preferable to use an acrylic copolymer having a carbon-carbon double bond at the side chain or molecular end. Examples of the group having a carbon-carbon double bond include a vinyl group, an allyl group, an acrylic group, and a methacryl group. An acrylic copolymer having such a functional group in the side chain or molecular end is composed of a glycidyl group, an isocyanate group, and a carbon-carbon with respect to the mercapto group, amino group, hydroxyl group, and carboxyl group in the acrylic copolymer. It can be synthesized by a reaction of a compound having a double bond, acrylic acid chloride, methacrylic acid chloride or allyl chloride.

  Examples of the compound having a glycidyl group and a carbon-carbon double bond include glycidyl methacrylate, glycidyl acrylate, allyl glycidyl ether, glycidyl ethyl acrylate, crotonyl glycidyl ether, glycidyl crotonate, and glycidyl isocrotonate. Examples of the compound having an isocyanate group and a carbon-carbon double bond include acryloyl isocyanate, methacryloyl isocyanate, acryloylethyl isocyanate, and methacryloylethyl isocyanate.

  Furthermore, the photosensitive paste of the present invention may contain a non-photosensitive polymer component as an organic component, for example, a cellulose compound such as methylcellulose and ethylcellulose, a high molecular weight polyether, and the like.

  The photosensitive monomer is a compound containing a carbon-carbon unsaturated bond. Specific examples thereof include methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, sec-butyl acrylate. , Isobutyl acrylate, tert-butyl acrylate, n-pentyl acrylate, allyl acrylate, benzyl acrylate, butoxyethyl acrylate, butoxytriethylene glycol acrylate, cyclohexyl acrylate, dicyclopentanyl acrylate, dicyclopentenyl acrylate, 2-ethylhexyl acrylate, glycerol Acrylate, glycidyl acrylate, heptadecafluorodecyl acrylate, 2-hydroxyethyl acrylate , Isobornyl acrylate, 2-hydroxypropyl acrylate, isodecyl acrylate, isooctyl acrylate, lauryl acrylate, 2-methoxyethyl acrylate, methoxyethylene glycol acrylate, methoxydiethylene glycol acrylate, octafluoropentyl acrylate, phenoxyethyl acrylate, stearyl acrylate, Trifluoroethyl acrylate, allylated cyclohexyl diacrylate, 1,4-butanediol diacrylate, 1,3-butylene glycol diacrylate, ethylene glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate, di Pentaerythritol hexaac Rate, dipentaerythritol monohydroxypentaacrylate, ditrimethylolpropane tetraacrylate, glycerol diacrylate, neopentyl glycol diacrylate, propylene glycol diacrylate, polypropylene glycol diacrylate, triglycerol diacrylate, trimethylolpropane triacrylate, tetrapropylene glycol Dimethacrylate, acrylamide, aminoethyl acrylate, phenyl acrylate, phenoxyethyl acrylate, benzyl acrylate, 1-naphthyl acrylate, 2-naphthyl acrylate, bisphenol A diacrylate, diacrylate of bisphenol A-ethylene oxide adduct, bisphenol A-propylene oxide With Additive diacrylate, thiophenol acrylate, benzyl mercaptan acrylate, a monomer in which 1 to 5 hydrogen atoms of these aromatic rings are substituted with chlorine or bromine atoms, or styrene, p-methylstyrene, o -Methyl styrene, m-methyl styrene, chlorinated styrene, brominated styrene, α-methyl styrene, chlorinated α-methyl styrene, brominated α-methyl styrene, chloromethyl styrene, hydroxymethyl styrene, carboxymethyl styrene, vinyl Naphthalene, vinyl anthracene, vinyl carbazole, and those obtained by substituting a part or all of the acrylates in the molecule of the above compounds with methacrylate, γ-methacryloxypropyltrimethoxysilane, 1-vinyl-2-pyrrolidone, etc. In the polyfunctional monomer, the group having an unsaturated bond may be a mixture of an acryl group, a methacryl group, a vinyl group, and an allyl group. In the present invention, one or more of these can be used.

  The photosensitive paste used in the present invention preferably further contains a urethane compound. By including a urethane compound, the flexibility of the paste dry film is improved, the stress during firing can be reduced, and defects such as cracks and disconnections can be effectively suppressed. Moreover, by containing a urethane compound, thermal decomposability improves and it becomes difficult to generate | occur | produce a baking residue in a baking process. Examples of the urethane compound preferably used in the present invention include compounds represented by the following general formula (1).

Here, R ₁ and R ₂ are selected from the group consisting of a substituent containing an ethylenically unsaturated group, hydrogen, an alkyl group having 1 to 20 carbon atoms, an allyl group, an aralkyl group, and a hydroxyaralkyl group, Each may be the same or different. R ₃ is an alkylene oxide group or alkylene oxide oligomer, and R ₄ is an organic group containing a urethane bond. n is an integer of 1-10.
As such a urethane compound, a compound containing an ethylene oxide unit is preferable. More preferably, in the general formula (1), R ₄ is an oligomer containing an ethylene oxide unit (hereinafter referred to as EO) and a propylene oxide unit, and the EO content in the oligomer is 8 to 70% by mass. A compound that is within range. When the EO content is 70% by mass or less, the flexibility is further improved and the firing stress can be reduced, so that defects can be effectively suppressed. Furthermore, the thermal decomposability is improved, and the firing residue is less likely to occur in the subsequent firing step. Moreover, compatibility with other organic components improves because EO content is 8% or more.

  It is also preferred that the urethane compound has a carbon-carbon double bond. When the carbon-carbon double bond of the urethane compound reacts with the carbon-carbon double bond of another crosslinking agent and is contained in the crosslinked product, polymerization shrinkage can be further suppressed.

  Specific examples of urethane compounds preferably used in the present invention include UA-2235PE (molecular weight 18000, EO content 20%), UA-3238PE (molecular weight 19000, EO content 10%), UA-3348PE (molecular weight 22000, EO). Content rate 15%), UA-5348PE (molecular weight 39000, EO content rate 23%) (the above-mentioned, Shin-Nakamura Chemical Co., Ltd. product) etc. are mentioned, However, It is not limited to these. Moreover, you may use these compounds in mixture.

  It is preferable that content of a urethane compound is 0.1-10 mass% of the organic component except a solvent. By setting the content to 0.1% by mass or more, the flexibility of the paste dry film can be improved, and the firing shrinkage stress when the paste dry film is fired can be reduced. When the content exceeds 10% by mass, the dispersibility of the organic component and the inorganic component is lowered, and the concentrations of the monomer and the photopolymerization initiator are relatively lowered, so that defects are likely to occur.

  As the photopolymerization initiator, a photo radical initiator that generates radicals upon irradiation with an active light source can be preferably used. Specific examples thereof include benzophenone, methyl o-benzoylbenzoate, and 4,4-bis (dimethylamino). Benzophenone, 4,4-bis (diethylamino) benzophenone, 4,4-dichlorobenzophenone, 4-benzoyl-4-methyldiphenyl ketone, dibenzyl ketone, fluorenone, 2,2-diethoxyacetophenone, 2,2-dimethoxy-2 -Phenylacetophenone, 2-hydroxy-2-methylpropiophenone, pt-butyldichloroacetophenone, thioxanthone, 2-methylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone, diethylthioxanthone, benzyl, Dilmethoxyethyl acetal, benzoin, benzoin methyl ether, benzoin butyl ether, anthraquinone, 2-t-butylanthraquinone, 2-amylanthraquinone, β-chloroanthraquinone, anthrone, benzanthrone, dibenzosuberone, methyleneanthrone, 4-azidobenzal Acetophenone, 2,6-bis (p-azidobenzylidene) cyclohexanone, 2,6-bis (p-azidobenzylidene) -4-methylcyclohexanone, 1-phenyl-1,2-butadion-2- (O-methoxycarbonyl) Oxime, 1-phenyl-1,2-propanedione-2- (O-ethoxycarbonyl) oxime, 1,3-diphenylpropanetrione-2- (O-ethoxycarbonyl) oxime, 1-phenyl-3-ethyl Toxipropanetrione-2- (O-benzoyl) oxime, Michler's ketone, 2-methyl-1- [4- (methylthio) phenyl] -2-morpholino-1-propanone, 2-benzyl-2-dimethylamino-1- ( 4-morpholinophenyl) -1-butanone, naphthalenesulfonyl chloride, quinolinesulfonyl chloride, N-phenylthioacridone, 4,4-azobisisobutyronitrile, diphenyl disulfide, benzthiazole disulfide, triphenylformine, camphorquinone And combinations of photoreducing dyes such as carbon tetrabrominated carbon, tribromophenyl sulfone, benzoin peroxide and eosin, and methylene blue with reducing agents such as ascorbic acid and triethanolamine. In the present invention, one or more of these can be used. A photoinitiator is 0.05-20 mass% with respect to the total amount of a photosensitive monomer and a photosensitive polymer, More preferably, it adds in 0.1-15 mass%. If the amount of the polymerization initiator is too small, the photosensitivity may be deteriorated. If the amount of the photopolymerization initiator is too large, the residual ratio of the exposed portion may be too small.

  In the present invention, an antioxidant is preferably added. The antioxidant has one or more of a radical chain inhibiting action, a triplet elimination action, and a hydroperoxide decomposition action. When an antioxidant is added to the photosensitive paste, an extra photoreaction caused by scattered light is suppressed by the antioxidant capturing radicals or returning the energy state of the excited photopolymerization initiator to the ground state. The photoreaction occurs abruptly at an exposure amount that cannot be suppressed by the antioxidant, so that the contrast between dissolution and insolubility in the developer can be increased. Specifically, p-benzoquinone, naphthoquinone, p-xyloquinone, p-toluquinone, 2,6-dichloroquinone, 2,5-diacetoxy-p-benzoquinone, 2,5-dicaproxy-p-benzoquinone, hydroquinone, p-t -Butylcatechol, 2,5-dibutylhydroquinone, mono-t-butylhydroquinone, 2,5-di-t-amylhydroquinone, di-t-butyl-p-cresol, hydroquinone monomethyl ether, α-naphthol, hydrazine hydrochloride , Trimethylbenzylammonium chloride, trimethylbenzylammonium oxalate, phenyl-β-naphthylamine, parabenzylaminophenol, di-β-naphthylparaphenylenediamine, dinitrobenzene, trinitrobenzene, picric acid, quinonedioxime, Lohexanone oxime, pyrogallol, tannic acid, triethylamine hydrochloride, dimethylaniline hydrochloride, cuperone, 2,2′-thiobis (4-tert-octylphenolate) -2-ethylhexylaminonickel- (II), 4, 4′-thiobis- (3-methyl-6-tert-butylphenol), 2,2′-methylenebis- (4-methyl-6-tert-butylphenol), triethylene glycol-bis [3- (3-tert-butyl) -5-methyl-4-hydroxyphenyl) propionate], 1,6-hexanediol-bis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate], 1,2,3-tri Examples include, but are not limited to, hydroxybenzene. In the present invention, one or more of these can be used. The addition amount of the antioxidant is preferably 0.1 to 30% by mass, more preferably 0.5 to 20% by mass in the photosensitive paste. By making the addition amount of the antioxidant within this range, it is possible to maintain the photosensitivity of the photosensitive paste, and maintain the degree of polymerization and maintain the pattern shape, while increasing the contrast between the exposed portion and the non-exposed portion. it can.

  An organic solvent is used to adjust the viscosity at the time of applying the photosensitive paste to the substrate according to the application method. The organic solvents used at this time are methyl cellosolve, ethyl cellosolve, butyl cellosolve, methyl ethyl ketone, dioxane, acetone, cyclohexanone, cyclopentanone, isobutyl alcohol, isopropyl alcohol, tetrahydrofuran, dimethyl sulfoxide, γ-butyrolactone, bromobenzene, chlorobenzene, dibromo Benzene, dichlorobenzene, bromobenzoic acid, chlorobenzoic acid and the like, and organic solvent mixtures containing one or more of these are used.

  The photosensitive paste of the present invention contains a low softening point glass powder, a metal hydroxide powder, a photosensitive organic component, an ultraviolet absorber, an antioxidant, a photopolymerization initiator, a dispersant, a solvent, and the like. After preparing the composition, the mixture is uniformly kneaded using a kneading apparatus such as a three-roller to produce a photosensitive paste. In addition, it is also preferable to appropriately filter and degas the photosensitive paste after the main kneading.

  The present invention relates to a pattern forming method characterized in that at least the photosensitive paste of the present invention thus obtained is applied, exposed, developed and baked. By using the pattern forming method of the present invention, a high-strength and high-definition pattern can be formed.

  Furthermore, this invention relates to the manufacturing method of the member for flat display panels including the process of forming a partition pattern using the above-mentioned pattern formation method. By the method for manufacturing a flat display panel member of the present invention, a flat display panel member having a high-strength and high-definition partition pattern can be manufactured accurately and stably.

  A procedure for producing a plasma display panel member will be described below. Here, the basic structure and the like will be described using the most common alternating current (AC) plasma display as an example of the plasma display, but the plasma display is not necessarily limited thereto.

  The plasma display is a member formed by sealing the front plate and the rear plate so that the phosphor layer formed on the front plate, the rear plate, or both faces the inner space, and discharges into the inner space. Gas is sealed. On the front plate, a transparent electrode (sustain electrode, scan electrode) for display discharge is formed on a substrate on the display surface side. Because of the discharge, the gap between the sustain electrode and the scan electrode should be relatively narrow. A bus electrode may be formed on the back side of the transparent electrode for the purpose of forming a lower resistance electrode. However, the bus electrode is made of Ag, Cr / Cu / Cr or the like and is often opaque. Therefore, unlike the transparent electrode, it interferes with the display of the cell, and is preferably provided at the outer edge of the display surface. In the case of an AC type plasma display, a transparent dielectric layer and an MgO thin film as a protective film are often formed on the upper layer of the electrode. On the back plate, electrodes (address electrodes) for selecting cells to be displayed are formed. The partition walls and phosphor layers for partitioning the cells may be formed on either or both of the front plate and the back plate, but are often formed only on the back plate. In the plasma display, the front plate and the back plate are sealed, and a discharge gas such as Xe-Ne or Xe-Ne-He is sealed in an internal space between the two.

  First, regarding the member manufacturing process, a method for manufacturing the front plate will be described. As the substrate, “PP8” (manufactured by Nippon Electric Glass Co., Ltd.) and “PD200” (manufactured by Asahi Glass Co., Ltd.), which are heat-resistant glass for soda glass and plasma display, can be used. The size of the glass substrate is not particularly limited, and a glass substrate having a thickness of 1 to 5 mm can be used.

  First, indium-tin oxide (ITO) is sputtered on a glass substrate, and a pattern is formed by a photoetching method. Subsequently, the black electrode paste for black electrodes is printed. The black electrode paste is composed mainly of an organic binder, a black pigment, conductive powder, and a photosensitive component when used in a photolithography method. As the black pigment, a metal oxide is preferably used. Examples of metal oxides include titanium black, copper, iron, manganese oxides and their composite oxides, and cobalt oxides. Cobalt oxides are less susceptible to fading when mixed with glass and fired. Is excellent. Examples of the conductive powder include metal powder and metal oxide powder. As the metal powder, gold, silver, copper, nickel or the like that is usually used as an electrode material can be used without any particular limitation. Since this black electrode has a high resistivity, an electrode paste having a high conductivity (for example, a material containing silver as a main component) is printed on the black electrode paste in order to produce a bus electrode by producing an electrode with a low resistivity. Print on the side. As this conductive paste, an electrode paste for address electrodes can also be suitably used. Then, batch exposure / development is performed to produce a bus electrode pattern. In order to ensure the conductivity, a highly conductive electrode paste may be printed again before development, and may be collectively developed after re-exposure. After the bus electrode pattern is formed, baking is performed. Thereafter, it is preferable to form a black stripe or a black matrix in order to improve contrast. The film thicknesses of the black electrode paste after firing and the conductive paste after firing are each preferably in the range of 1 to 5 μm. Moreover, it is preferable that the line | wire width after baking is 20-100 micrometers.

  Next, a transparent dielectric layer is formed using a transparent dielectric paste. The transparent dielectric paste is mainly composed of an organic binder, an organic solvent, and glass, but an additive such as a plasticizer may be appropriately added. The method for forming the transparent dielectric layer is not particularly limited. For example, the transparent dielectric paste is applied on the entire surface of the electrode forming substrate by screen printing, bar coater, roll coater, die coater, blade coater, spin coater, or the like. After application, the thick film can be formed by drying using an optional oven such as a ventilating oven, a hot plate, an infrared drying oven, or vacuum drying. It is also possible to make the transparent dielectric paste into a green sheet and laminate it on the electrode forming substrate. The thickness is preferably 10 μm to 30 μm.

  Next, firing is performed in a firing furnace. The firing atmosphere and temperature vary depending on the type of paste and substrate, but firing is performed in air, in an atmosphere of nitrogen, hydrogen, or the like. As the firing furnace, a batch-type firing furnace or a roller conveyance type continuous firing furnace can be used. The baking temperature is preferably a temperature at which the resin to be used sufficiently debinds. Usually, when an acrylic resin is used, baking is performed at 430 to 650 ° C. If the firing temperature is too low, the resin component tends to remain, and if it is too high, the glass substrate may be distorted and cracked.

Further, a protective film is formed. As the protective film, MgO, MgGd ₂ O ₄ , BaGd ₂ O ₄ , Sr _0. At least one of 6Ca _0.4 Gd ₂ O ₄ , Ba _0.6 Sr _0.4 Gd ₂ O ₄ , SiO ₂ , TiO ₂ , Al ₂ O ₃ , and the aforementioned low softening point glass may be used. In particular, MgO is preferable. A known technique such as electron beam evaporation or ion plating can be used as a method for forming the protective film.

  Next, a method for manufacturing the back plate will be described. As the glass substrate, soda glass, “PD200”, “PP8” can be used as in the case of the front plate. A stripe-shaped conductive pattern for address electrodes is formed on a glass substrate with a metal such as silver, aluminum, chromium, or nickel. As a forming method, these metal powders and a metal paste mainly composed of an organic binder are pattern-printed by screen printing, or after applying a photosensitive metal paste using a photosensitive organic component as an organic binder, It is possible to use a photosensitive paste method in which pattern exposure is performed using a mask, unnecessary portions are dissolved and removed in a development step, and further heated and baked at 350 to 600 ° C. to form an electrode pattern. Further, an etching method can be used in which after chromium or aluminum is vapor-deposited on a glass substrate, a resist is applied, and after the resist is subjected to pattern exposure and development, unnecessary portions are removed by etching. Furthermore, it is preferable to provide a dielectric layer on the address electrode. By providing the dielectric layer, it is possible to improve the stability of discharge and to prevent the partition wall formed on the upper layer of the dielectric layer from falling or peeling off. In addition, as a method for forming the dielectric layer, a dielectric paste mainly composed of an inorganic component such as glass powder or high softening point glass powder and an organic binder is printed or applied on the entire surface by screen printing, a slit die coater or the like. and so on.

  Next, a method for forming partition walls by photolithography will be described. The partition pattern is not particularly limited, but a lattice shape, a waffle shape or the like is preferable. First, a barrier rib paste made of the photosensitive paste of the present invention is applied on a substrate on which a dielectric is formed. As a coating method, methods such as a bar coater, a roll coater, a slit die coater, a blade coater, and screen printing can be used. The coating thickness can be determined in consideration of the desired partition wall height and the shrinkage rate due to baking of the paste. The coating thickness can be adjusted by the number of coatings, screen mesh, paste viscosity, and the like.

The applied partition paste is dried and then exposed. In general, the exposure is performed through a photomask, as in normal photolithography. Alternatively, a method of directly drawing with a laser beam or the like without using a photomask may be used. As the exposure apparatus, a stepper exposure machine, a proximity exposure machine, or the like can be used. Examples of the actinic rays used at this time include near infrared rays, visible rays, and ultraviolet rays. Among these, ultraviolet rays are most preferable, and as the light source, for example, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultrahigh-pressure mercury lamp, a halogen lamp, or a germicidal lamp can be used. Among these, an ultrahigh pressure mercury lamp is suitable. Although exposure conditions vary depending on the coating thickness, exposure is usually performed for 0.01 to 30 minutes using an ultrahigh pressure mercury lamp having an output of 1 to 100 mW / cm ² .

  After the exposure, development is performed by utilizing the difference in solubility between the exposed portion and the non-exposed portion in the developer. Usually, the immersion method, the spray method, the brush method, and the like are performed. As the developer, an organic solvent in which an organic component in the photosensitive paste can be dissolved can be used. However, when a compound having an acidic group such as a carboxyl group is present in the photosensitive paste, development can be performed with an alkaline aqueous solution. As the alkaline aqueous solution, sodium hydroxide, sodium carbonate, potassium hydroxide aqueous solution or the like can be used. However, it is preferable to use an organic alkaline aqueous solution because an alkaline component can be easily removed during firing.

  As the organic alkali, a general amine compound can be used. Specific examples include tetramethylammonium hydroxide, trimethylbenzylammonium hydroxide, monoethanolamine, and diethanolamine.

  The density | concentration of aqueous alkali solution is 0.05-5 mass% normally, More preferably, it is 0.1-1 mass%. If the alkali concentration is too low, it is difficult to remove the soluble part, and if the alkali concentration is too high, the pattern may be peeled off or corroded, which is not preferable. The development temperature during development is preferably 20 to 50 ° C. in terms of process control.

  Moreover, the partition may be composed of two or more layers. By using a structure of two or more layers, the configuration range of the partition wall shape can be expanded three-dimensionally. For example, in the case of a two-layer structure, the first layer is applied and exposed in a stripe shape, then the second layer is applied, the first layer is exposed to a stripe shape in the vertical direction, and development is performed, thereby causing unevenness. It is possible to form a partition wall having a cross-beam structure.

  Next, baking is performed by holding at a temperature of 520 to 620 ° C. for 10 to 60 minutes in a baking furnace to form partition walls.

  The photosensitive paste of the present invention is suitable for forming the above-described partition wall, and by using the photosensitive glass paste of the present invention, a high-strength and high-definition partition wall can be formed with high accuracy.

Next, a phosphor layer is formed using the phosphor paste. The phosphor layer can be formed by a photolithography method using a photosensitive phosphor paste, a dispenser method, a screen printing method, or the like. Although the thickness of a fluorescent substance layer is not specifically limited, It is 10-30 micrometers, More preferably, it is 15-25 micrometers. The phosphor powder is not particularly limited, but the following phosphors are preferable from the viewpoint of light emission intensity, chromaticity, color balance, lifetime, and the like. Blue is an aluminate phosphor (for example, BaMgAl ₁₀ O ₁₇ : Eu) or CaMgSi ₂ O ₆ activated with divalent europium. In the case of green, Zn ₂ SiO ₄ : Mn, YBO ₃ : Tb, BaMg ₂ Al ₁₄ O ₂₄ : Eu, Mn, BaAl ₁₂ O ₁₉ : Mn, and BaMgAl ₁₄ O ₂₃ : Mn are preferable in terms of panel luminance. More preferably _Zn 2 _SiO 4: is Mn. In red, (Y, Gd) BO ₃ : Eu, Y ₂ O ₃ : Eu, YPVO: Eu, and YVO ₄ : Eu are also preferable. More preferred is (Y, Gd) BO ₃ : Eu. When the phosphor is formed through the firing step, it may be performed simultaneously with the above-described firing of the dielectric layer and the partition wall.

  Hereinafter, the present invention will be specifically described by way of examples. However, the present invention is not limited to this.

The average particle size (d ₅₀ ) and the maximum particle size (d _max ) of the following inorganic powders are values measured using “MT3300” manufactured by Nikkiso Co., Ltd.

A. Photosensitive paste raw materials The following raw materials were used for the photosensitive paste for partition walls.
Photosensitive monomer M-1: trimethylolpropane triacrylate photosensitive monomer M-2: tetrapropylene glycol dimethacrylate photosensitive polymer: carboxyl group of copolymer consisting of methacrylic acid / methyl methacrylate / styrene = 40/40/30 To which 0.4 equivalent of glycidyl methacrylate was added and reacted (weight average molecular weight 43,000, acid value 100)
Photopolymerization initiator: 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -1-butanone (IC369 manufactured by Ciba Specialty Chemicals)
Antioxidant: 1,6-hexanediol-bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate]
UV absorber: Sudan IV (manufactured by Tokyo Ohka Kogyo Co., Ltd.)
Solvent: γ-butyrolactone low softening point glass powder: lithium oxide 7% by mass, silicon oxide 22% by mass, boron oxide 33% by mass, zinc oxide 3% by mass, aluminum oxide 19% by mass, magnesium oxide 6% by mass, barium oxide 5 Mass%, calcium oxide 5 mass% (glass transition temperature 491 ° C., d ₅₀ : 2 μm, d _max : 10 μm)
High softening point glass powder: 1% by mass of sodium oxide, 40% by mass of silicon oxide, 10% by mass of boron oxide, 33% by mass of aluminum oxide, 4% by mass of zinc oxide, 9% by mass of calcium oxide, 3% by mass of titanium oxide (glass transition Temperature: 652 ° C., d ₅₀ : 2 μm, d _max : 10 μm)
Metal hydroxide powder H-1: Aluminum hydroxide powder with an average particle size (d ₅₀ ) of 2 μm Metal hydroxide powder H-2: Aluminum hydroxide powder with an average particle size (d ₅₀ ) of 1 μm Metal hydroxide powder H -3: Magnesium hydroxide powder metal hydroxide powder H-4 having an average particle diameter (d ₅₀ ) of 1.5 μm: Zirconium hydroxide powder metal oxide powder O-1 having an average particle diameter (d ₅₀ ) of 1 μm: Average particle Aluminum oxide powder metal oxide powder O-2 having a diameter (d ₅₀ ) of 2 μm: Aluminum oxide powder metal oxide powder O-3 having an average particle diameter (d ₅₀ ) of 1 μm: Oxidation having an average particle diameter (d ₅₀ ) of 1.5 μm Magnesium powder metal oxide powder O-4: Zirconium oxide powder having an average particle diameter (d ₅₀ ) of 1 μm. Preparation of photosensitive paste 10 parts by weight of photosensitive monomer M-1, 10 parts by weight of photosensitive monomer M-2, 20 parts by weight of photosensitive polymer, 3 parts by weight of photopolymerization initiator, and 1 part by weight of antioxidant Part and an ultraviolet absorber were weighed in 0.02 part by weight, and then γ-BL was added appropriately as a solvent to adjust the viscosity. Next, the low softening point glass powder, the high softening point glass powder, the metal hydroxide powder, and the metal oxide powder are in the volume ratio shown in Table 1, and the content ratio (volume%) of the inorganic component in the solid content is 49%. It added so that it might become. This organic-inorganic mixture was kneaded with a three-roller kneader to obtain a photosensitive paste.

B. Manufacture of display member A plasma display back plate was prepared by the following procedure. Address electrode patterns were formed on a “PD-200” glass substrate (42 inches) manufactured by Asahi Glass Co., Ltd. by photolithography using a photosensitive silver paste. Next, a dielectric layer having a thickness of 20 μm was formed on the glass substrate on which the address electrodes were formed by screen printing. Thereafter, the photosensitive paste was uniformly applied on the back plate glass substrate on which the address electrode pattern and the dielectric layer were formed by screen printing until a desired thickness was obtained. Intermediate drying was performed at 100 ° C. for 10 minutes. Subsequently, exposure was performed through an exposure mask. The exposure mask is a chromium mask designed to enable the formation of stripe-shaped barrier rib patterns in a plasma display with a pitch of 160 μm and a line width of 20 μm. Exposure, Examples and ultra-high pressure mercury lamp with an output of each photosensitive paste per 50 mW / cm ² of Comparative Example from 100 mJ / cm ² to 500 mJ / cm ^2, were UV exposure to 5 mJ / cm ² intervals.

  Next, a 0.3% by mass aqueous solution of monoethanolamine kept at 35 ° C. was developed by applying it for 150 seconds in a shower, and was washed with water using a shower spray to remove the uncured space portion. For the evaluation of the partition pattern processability, samples with different bottom exposure widths of 80 μm were selected from samples with different exposure doses, and the presence or absence of residual film formation in the unexposed areas was confirmed with an optical microscope. If it is ○, if it is, ×.

  The selected sample was held at 560 ° C. for 30 minutes and fired to form partition walls, and then the phosphor layer was formed to a thickness of 20 μm by the dispenser method and fired to obtain a back plate.

C. Separation of partition wall The back plate was cut into 5cm x 13cm for a sample with a partition wall pattern workability of ○, and 4 points in the center of the substrate and 4 points on the center were marked, and the same size was attached to the front plate. Then, with the back plate side down, a metal ball having a weight of 114 g was dropped from the top to 5 points marked from the height of 30 cm twice. Thereafter, a 1 cm square portion at the center of the substrate was cut out, and a photograph of a partition wall missing portion was taken with a scanning electron microscope. From the photograph taken, the number of partition wall defects was measured. This evaluation is a model test for the occurrence of defects when the front plates are stuck together or subjected to an impact during transportation, and the number of partition wall defects is preferably 50 pieces / cm ² or less.

  Evaluation Results Table 2 shows the evaluation results of the back plates produced using the photosensitive pastes obtained in Examples 1 to 16 and Comparative Examples 1 to 14.

All the photosensitive pastes of Examples 1 to 16 were excellent in pattern processability, and the number of partition wall chips was small. On the other hand, it was found that Comparative Examples 1 and 2 not containing the metal hydroxide powder were excellent in pattern processability, but had a large number of partition wall chips and inferior in strength. In Comparative Examples 3 to 6 using the corresponding metal oxide instead of the metal hydroxide, the difference in the refractive index between the organic component and the metal oxide is large, so that a residue is generated due to scattering of exposure light, resulting in pattern processability. There was a problem. About Comparative Examples 7-10 which reduced the addition amount of the metal oxide, although the pattern workability was excellent, there were many partition wall chip | tips and there existed a problem in intensity | strength. In Comparative Examples 11 to 14 in which the addition amount of the low softening point glass powder is less than 50% by volume in all the inorganic components, it is difficult to sinter at the time of firing, and the porosity of the pattern after firing becomes large, so that the partition wall is missing. There were many problems with strength.

Claims (4)

A photosensitive glass paste comprising an organic component containing a photosensitive organic component and an inorganic component comprising a low softening point glass powder occupying 50% by volume or more of all inorganic components, and further comprising a metal hydroxide powder in the inorganic component A photosensitive glass paste characterized by that. The photosensitive glass paste according to claim 1, wherein the metal hydroxide is any one of aluminum hydroxide, magnesium hydroxide, and zirconium hydroxide. A method for forming a pattern, comprising at least coating, exposing, developing, and baking the photosensitive paste according to claim 1. The manufacturing method of the member for flat display panels including the process of forming a partition using the formation method of the pattern of Claim 3.