JP2004182589A - Paste and method for manufacturing member for display panel using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a paste which can be homogeneously and rapidly applied to a base surface. <P>SOLUTION: The paste is composed of an inorganic powder and organic components. The paste has a yield value which is characteristically shown in the viscosity range of 200-20,000 [Pa×s]. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

  The present invention relates to a paste and a method for manufacturing a display panel member such as a plasma display and a plasma addressed liquid crystal display using the paste.

  2. Description of the Related Art Plasma display panels (hereinafter, referred to as PDPs) can permeate at higher speeds than liquid crystal panels, and are easy to increase in size, and thus have permeated OA equipment and public information display devices. Further, progress in the field of high-definition television is highly expected. With such expanded use, color PDPs having fine and large numbers of display cells are receiving attention.

  The PDP generates plasma discharge between electrodes in a discharge space provided between a front glass substrate and a rear glass substrate, and emits ultraviolet light generated from a gas sealed in the discharge space to a fluorescent light in the discharge space. The display is performed by touching the body. In this case, a partition having a width of about 20 to 80 μm and a height of about 20 to 200 μm in order to suppress the spread of discharge to a certain area and to perform display in a specified cell and to secure a uniform discharge space. Is provided.

  As a method of forming the partition walls, a glass paste is printed and dried by screen printing, this process is repeated many times, after a predetermined height, a method of baking, and a photolithographic technique using a photosensitive glass paste There is known a method of forming a partition by sandblasting or liquid honing through a subtractive mask layer formed by a photolithography method.

Conventionally, a screen printing method is known as a method of applying a glass paste or a photosensitive glass paste used for forming the partition walls to a substrate. However, in this method, a single application thickness is several tens of μm. In order to form a partition layer having a height of 20 to 200 μm, it is necessary to repeat printing / drying many times, generally ten times or more, and the productivity is extremely poor. As a method of coating the entire surface of the substrate at one time, a method of applying by a doctor blade method, a slit die coater method, or the like has been proposed. However, even with this method, the conventional glass paste has a problem in that the coating film at the edge of the substrate rises, and a high-quality PDP cannot be obtained. As a method for solving this problem, a method of controlling the thixotropic index of the paste has been proposed (for example, see Patent Document 1). Certainly, by controlling the thixotropy index of the paste, it is possible to perform uniform application over the entire surface of the substrate, but with this paste, high-speed uniform application is not possible, and there has been a problem that PDP productivity cannot be improved.
JP-A-2000-327371 (pages 3 to 8)

  Therefore, an object of the present invention is to provide a paste that enables uniform high-speed application within a substrate surface in view of the above-described conventional technology.

  Another object of the present invention is to provide a method for manufacturing a member for a plasma display panel at low cost using such a paste.

  That is, the present invention relates to a paste comprising an inorganic powder and an organic component, wherein the paste has a yield value, and the viscosity showing the yield value is in the range of 200 to 20,000 [Pa · s]. is there.

  Further, the present invention is a method for manufacturing a display panel member including a step of applying a paste on a substrate and drying the paste, wherein the paste is used.

  By using a paste characterized in that the paste has a yield value and the viscosity indicating the yield value is in the range of 200 to 20,000 [Pa · s], high-speed coating is possible, and the plasma display panel can be manufactured at low cost. Member can be provided.

  The paste in the present invention is composed of an inorganic powder and an organic component. The content of the inorganic powder is preferably from 35 to 95% by weight, and more preferably from 40 to 90% by weight, since the shrinkage during firing is small and the change in shape due to firing is small. Examples of the inorganic powder in the paste include glass powder, metal powder, and refractory filler.

The glass powder preferably has a coefficient of thermal expansion at 50 to 400 ° C. of 50 × 10 ^{−7 to} 100 × 10 ⁻⁷ . In addition, by mixing silicon oxide in the glass in the range of 3 to 60% by weight and boron oxide in the range of 5 to 50% by weight, it is required as a partition wall for electric insulation, strength, coefficient of thermal expansion, and denseness of the insulating layer. The improved electrical, mechanical and thermal properties can be improved. The glass powder in the present invention is preferably mainly composed of a low-melting glass powder. The glass transition temperature of the low melting glass powder is preferably 430 to 500 ° C, and the glass softening point is preferably 470 to 620 ° C. When the glass transition temperature and the glass softening point are in these ranges, the distortion of the substrate during firing is small, and a dense partition layer can be obtained. The particle size of the glass powder is selected in consideration of the line width and height of the partition wall to be produced, but the center diameter of the volume-based distribution is 1 to 6 μm, the maximum particle size is 30 μm or less, and the specific surface area is 1.5 to 1.5 μm. It is preferably 4 cm ² / g.

  As the metal powder, a powder containing at least one selected from the group consisting of Ag, Au, Pd, Ni, Cu, Al and Pt can be used. These can be used singly, in an alloy, or in a mixed powder state. As the particle diameter of the metal powder, the center diameter of the volume-based distribution is preferably 0.7 to 6 μm. More preferably, it is 1.3 to 4 μm. When the particle diameter is in this range, a fine and fine pattern can be formed.

  The refractory filler is preferably added to stabilize the shape during firing. As the refractory filler, those which do not soften at a firing temperature of about 500 to 650 ° C. can be widely used, and examples thereof include ceramic powders such as high melting point glass, alumina, magnesia, calcia, cordierite, silica, mullite, zircon, and zirconia. it can. When the partition walls are darkened in order to reduce the external light reflection of the PDP and increase the practical contrast, Co-Cr-Fe, Co-Mn-Fe, Co-Fe-Mn may be used as a fire-resistant black pigment. Pigments such as -Al, Co-Ni-Cr-Fe, Co-Ni-Mn-Cr-Fe, Co-Ni-Al-Cr-Fe, Co-Mn-AL-Cr-Fe-Si may be used. . On the other hand, when the partition walls are whitened for the purpose of effectively guiding the emission of the phosphor to the front surface of the panel, titania or the like may be used as a fire-resistant white pigment.

  Examples of the organic component in the present invention include a binder resin, an organic solvent, a plasticizer, an antioxidant, and an antifoaming agent. In particular, when the paste of the present invention is used as a photosensitive paste, photosensitive components such as a photosensitive polymer, a photosensitive oligomer, and a photosensitive monomer, a photopolymerization initiator, a sensitizer, an ultraviolet absorber, a polymerization inhibitor, and the like. Can be added.

  The binder resin in the paste of the present invention is preferably oxidized or / and decomposed or / and vaporized at the time of firing, and no carbide is left in the inorganic substance. Ethyl cellulose, methyl cellulose, nitrocellulose, cellulose acetate, cellulose propionate, cellulose butyrate Or a cellulose resin such as methyl (meth) acrylate, ethyl (meth) acrylate, normal butyl (meth) acrylate, isobutyl (meth) acrylate, isopropyl (meth) acrylate, 2-ethylmethyl (meth) acrylate, 2 Acrylic resins made of polymers or copolymers such as hydroxylethyl (meth) acrylate, poly-α-methylsulfone, polyvinyl alcohol, polybutene and the like are preferably used. The content of the binder resin in the paste of the present invention is preferably 5 to 65% by weight, more preferably 10 to 60% by weight.

  An organic solvent is used to adjust the viscosity when applying the paste to the substrate according to the application method. As the organic solvent used at this time, diethylene glycol monobutyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol mono-2-ethylhexyl ether, diethylene glycol mono-2-ethylhexyl ether, 2,2,4-trimethyl-1,3- Pentanediol monoisobutyrate, 2,2,4-trimethyl-1,3-pentanediol diisobutyrate, 2-ethyl-1,3-hexanediol, terpineol, benzyl alcohol, 1-butoxy-2-propane, , 2-diacetoxypropane, 1-methoxy-2-propanol, 2-acetoxy-1-ethoxypropane, (1,2-methoxypropoxy) -2-propanol, (1,2-ethoxypropoxy) -2-propanol Nol, 2-hydroxy-4-methyl-2-pentanone, 3-methoxy-3-methylbutyl acetate, 2-methoxyethanol, 2-ethoxyethanol, 2- (methoxymethoxy) ethanol, 2-isopropoxyethanol, 2- Butoxyethanol, 2- (isopentyloxy) ethanol, 2- (hexyloxy) ethanol, 2-phenoxyethanol, 2- (benzyloxy) ethanol, benzyl alcohol, furfuryl alcohol, tetrafurfuryl alcohol, 2,2′-dihydroxy Diethyl ether, 2- (2-methoxyethoxy) ethanol, 2- [2- (2-methoxyethoxy) ethoxy] ethanol, 2-methyl-1-butanol, 3-methyl-2-butanol, 2-methyl-1- Pentanol, 4-methyl -2-pentanol, 2-ethyl-1-butanol, 2-methoxyethyl acetate, 2-ethoxyethyl acetate, 2-butoxyethyl acetate, 2-phenoxyethyl acetate, 1,2-dimethoxyethane, 1,2-di Ethoxyethane, 1,2-dibutoxyethane, cyclohexanenone, methyl acetate, ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, cyclohexyl acetate, acetic acid Examples thereof include benzyl, hexane, cyclohexane, methyl ethyl ketone, 2-pentanone, 3-pentanone, 2-hexanone, methyl isobutyl ketone, 2-heptanone, 4-heptanone, and diisobutyl ketone. In the present invention, the paste preferably contains the organic solvent in the range of 20 to 70 wt%, more preferably 30 to 65 wt%. If the amount of the organic solvent is less than 20% by weight, the viscosity of the paste becomes high, and high-speed coating becomes difficult. On the other hand, if the amount of the organic solvent exceeds 70% by weight, sedimentation of the dispersed particles becomes faster, and it tends to cause problems such as difficulty in stabilizing the composition of the paste and requiring much energy and time for drying.

  When the paste of the present invention is used as a photosensitive paste, it is preferable to use a photosensitive polymer and / or a photosensitive oligomer as a binder resin. The oligomer or polymer is obtained by polymerization or copolymerization of a component selected from compounds having a carbon-carbon double bond.

  By copolymerizing an unsaturated acid such as an unsaturated carboxylic acid, the developability in an aqueous alkali solution after exposure can be improved. Specific examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, vinyl acetic acid, and acid anhydrides thereof.

  The acid value of the polymer or oligomer having an acidic group such as a carboxyl group in the side chain thus obtained is preferably 50 to 180, more preferably 70 to 140.

  As the photosensitive monomer, a compound having an active carbon-carbon unsaturated double bond is often used. As the functional group, monofunctional and polyfunctional compounds having a vinyl group, an allyl group, an acrylate group, a methacrylate group, and an acrylamide group can be applied. Specifically, 2- (2-ethoxyethoxy) ethyl acrylate, 1,3-butanediol diacrylate, pentaerythritol triacrylate, ditrimethylolpropane tetraacrylate, cyclohexyl methacrylate, ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate And glycidyl methacrylate.

  The photopolymerization initiator is preferably added in the range of 0.005 to 5% by weight based on the photosensitive paste in terms of photosensitive characteristics.

  The paste of the present invention requires the paste to have a yield value, the viscosity indicating the yield value to be in the range of 200 to 20,000 [Pa · s], and the yield value of the paste to be 0 to 2 [Pa]. And the viscosity exceeding the yield value is preferably in the range of 5 to 50 [Pa · s]. Here, the yield value and the viscosity are values measured using a rheometer of Visco Analyzer VAR-50 manufactured by Jusco International Co., Ltd., and the measurement temperature is 25 ° C. As the yield value, the viscosity is plotted on the vertical axis and the stress is plotted on the horizontal axis, and the yield value is determined at the point where the viscosity shows the maximum value.

  The paste has a yield value, and the viscosity indicating the yield value is in the range of 200 to 20,000 [Pa · s], preferably 300 to 10,000 [Pa · s], and the yield value of the paste is 0 to 2 [Pa · s]. [Pa], preferably in the range of 0 to 1.5 [Pa], and the viscosity exceeding the yield value is in the range of 5 to 50 [Pa · s], preferably 10 to 40 [Pa · s]. This makes it possible to obtain a paste that can be uniformly applied at high speed within the substrate surface.

  In general, in the doctor blade method or the slit die coater method, etc., it is possible to apply the paste onto the substrate at a high speed by reducing the viscosity of the paste to be applied.However, simply reducing the viscosity of the paste causes the paste to flow after the application, There are problems such as a problem that the paste runs out of the application area, a problem that the paste flows immediately after the application and flows into the sealing hole, and a problem that the applied film thickness is not uniform in the plane. Regarding the flow characteristics of the paste, it is preferable that the fluidity is high at the time of application and the fluidity disappears immediately after application. Specifically, by lowering the viscosity of the paste and giving the paste a yield stress of a certain value or more, high-speed application becomes possible when the pressure at the time of application exceeds the yield stress of the paste. The fluidity is lost, and the coated shape can be maintained. In this case, in order to eliminate the fluidity immediately after the application, it is preferable that the viscosity indicating the yield stress is high.

  As described in JP-A-2000-327371, when a thixotropy-imparting agent is added to a paste, thixotropy is imparted to the paste and a certain amount of flow characteristics can be controlled. However, the thixotropy-imparting agent has a thickening effect. In some cases, high-speed coating becomes difficult only by adding a thixotropic agent.

  Therefore, in the present invention, the flow characteristics were successfully controlled by including the thixotropic agent (A) and the surfactant (B) in the paste, and high-speed coating was realized. In general, a thixotropic agent and a surfactant are not mixed and used because they have properties that bring out contradictory properties, but they work effectively in the present invention.

The preferred range of A / B is 0.04 to 120, more preferably 0.05 to 100, and most preferably 0.06 to 80.
You. If A / B is less than 0.02, a sufficient yield value cannot be obtained, and if A / B exceeds 120, the viscosity exceeding the yield value becomes high, and high-speed coating becomes difficult.

  Specific examples of the thixotropic agent used in the present invention include casein, glue, gelatin, gluten, soy protein, ammonium alginate, potassium alginate, sodium alginate, gum arabic, tragacanth gum, karaya gum, guar gum, locust bean gum, and irish. Moss, soy lecithin, pectic acid, starch, agar, bentonite clay, ammonium polyacrylate, sodium polyacrylate, ammonium polymethacrylate, acrylic polymer, acrylic emulsion copolymer, crosslinked acrylic emulsion copolymer, polyvinyl alcohol, vinyl polymer Potassium salt, modified poly (vinyl methyl ether / maleic anhydride), vinyl pyrrolidone copolymer, polyacrylamide, fatty acid amide, etc. Aliphatic amide compounds, polyethylene oxide, carboxylated methyl cellulose, hydroxyethyl cellulose, xanthate cellulose, carboxylated starch, oleic acid, ammonium oleate, sodium silicate, aluminum stearate and octoate, magnesium stearate, calcium stearate, etc. No.

  Further, the thixotropic agent preferably has a weight retention at 500 ° C. of 1% by weight or less measured under the following conditions. When the thixotropic agent was heated from 30 ° C. to 500 ° C. at 10 ° C./min under an air atmosphere (flow rate: 20 ml / min) using a thermogravimeter (“TGA-50”, manufactured by Shimadzu Corporation). The weight at 500 ° C. is measured, and the weight retention at 500 ° C. is calculated by determining the ratio to the weight at room temperature. When the weight retention rate at 500 ° C. is 1% by weight or less, the firing residue after the firing of the paste is reduced, and problems such as abnormal discharge and reduction in luminance, which lower the reliability of the display, can be suppressed. More preferably, it is 0.5% by weight or less, further preferably 0.2% by weight or less.

  Among the above thixotropic agents, it is preferable to use an aliphatic amide compound from the viewpoint of controlling the yield value of the paste and reducing the weight retention at 500 ° C. to 1% or less.

  Furthermore, fatty acid amides obtained by reacting hydroxystearic acid and alkyleneamine from the viewpoint of the effect of imparting thixotropic properties, fatty acid amides obtained by reacting a mixture of hydroxystearic acid and linear fatty acids with alkyleneamine, urethane compounds and aliphatic compounds A urea compound obtained by reacting an isocyanate residue and an amine residue of an amide compound, a blend of a polyamide composed of a fatty acid, a polycarboxylic acid, and a polyamine, and a hydrogenated castor oil are preferable. Specifically, N, N'-12-hydroxystearic acid ethylenediamide, N, N'-12-hydroxystearic acid hexamethylenediamide, N, N'-12-hydroxystearic acid xylyleneamide, 12-hydroxystearin Mixture of acid and caproic acid, captylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid and ethylenediamine, hexamethylenediamine, propylenediamine, butylenediamine, octamethylenediamine, diethylenetriamide, triethylene Examples thereof include fatty acid amides obtained by reacting tetramine and the like.

  If these thixotropic agents are directly added to the glass paste, the dispersibility may be poor. Therefore, it is preferable that the thixotropic agents be dispersed in an organic solvent, heated, and then added to the glass paste. In this case, as the organic solvent used for dispersion, methanol, ethanol, alcoholic solvents such as benzyl alcohol, cyclopentane, cyclohexane, saturated hydrocarbons such as decalin, ethyl acetate, butyl acetate, amyl propionate, methyl adipate Such esters can be preferably used, but are not limited thereto. The heating treatment is preferably performed within a range of 30 to 100 ° C. for 1 to 72 hours.

  In the glass paste of the present invention, it is preferable to use one or more of the above thixotropic agents. The thixotropy-imparting agent is contained preferably in the range of 0.01 to 20% by weight, more preferably 0.05 to 10% by weight, based on the paste.

  Specific examples of the surfactant used in the paste of the present invention include sodium lauryl sulfate, sodium polyoxyethylene lauryl sulfate, triethanolamine polyoxyethylene lauryl sulfate, sodium polyoxyethylene lauryl ether acetate, and polyoxyethylene lauryl sulfosuccinic acid. Anionic surfactants such as disodium, coconut oil fatty acid sarcosine sodium, N-coconut fatty acid acyl-L-glutamate sodium, sodium lauryl phosphate, carboxymethylcellulose ammonium, carboxymethylcellulose sodium, castor oil sulfated oil, polycarboxylate and the like , Lauryl dimethylamine oxide, glyceryl monostearate, ethylene glycol monostearate, polyethylene glycol distearate, Sorbitan oleate, polyoxyethylene sorbitan monooleate, polyoxyethylene dioleate methyl gluoxide, polyoxyethylene tallow alkyl hydroxy myristyl ether, polyoxyethylene cetyl ether, polyoxyethylene nonyl phenyl ether, propylene glycol monostearate , Polyoxyethylene sorbite tetraoleate, polyoxyethylene hydrogenated castor oil, polyoxyethylene lanolin, polyoxyethylene octyl phenyl ether, polyoxyethylene dodecyl phenyl ether, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, polyoxyethylene Nonionic surfactants such as sorbitan fatty acid esters and fatty acid alkylolamides, stearyl chloride Trimethylammonium, behenyltrimethylammonium chloride, distearyldimethylammonium chloride, lanolin fatty acid aminopropylethyldimethylammonium ethyl sulfate, cetylpyridium chloride, lactate of stearate diethylaminoethylamide, citrate of dimethylaminopropylamide stearate, etc. Cationic surfactants, coconut oil fatty acid amidopropyldimethylaminoacetic acid betaine, lauryldimethylaminoacetic acid betaine, laurylhydroxysulfobetaine, lauroylamidoethylhydroxyethylcarboxymethylbetaine sodium hydroxypropyl phosphate, sodium β-laurylaminopropionate, etc. Examples include an amphoteric surfactant.

  Further, the surfactant preferably has a weight retention at 500 ° C. of 1% by weight or less measured under the following conditions. When the surfactant was heated from 30 ° C. to 500 ° C. at 10 ° C./min under an air atmosphere (flow rate: 20 ml / min) using a thermogravimeter (“TGA-50”, manufactured by Shimadzu Corporation) The weight at 500 ° C. is measured, and the weight retention at 500 ° C. is calculated by determining the ratio to the weight at room temperature. When the weight retention rate at 500 ° C. is 1% by weight or less, the firing residue after the firing of the paste is reduced, and problems such as abnormal discharge and reduction in luminance, which lower the reliability of the display, can be suppressed. More preferably, it is 0.5% by weight or less, further preferably 0.2% by weight or less.

  Among the above surfactants, it is preferable to use a nonionic surfactant because the yield value of the paste is controlled and the weight retention at 500 ° C. becomes 1% or less. More preferably, ethylene glycol monostearate, polyethylene glycol distearate, sorbitan monooleate, polyoxyethylene sorbitan monooleate, methyl gluoxide of polyoxyethylene dioleate, polyoxyethylene cetyl ether, propylene glycol monostearate, It is at least one selected from polyoxyethylene sorbite, polyoxyethylene alkyl ether, and polyoxyethylene fatty acid ester.

  In the glass paste of the present invention, it is preferable to use one or more of the above surfactants. The surfactant is preferably contained in the range of 0.01 to 10% by weight, more preferably 0.05 to 5% by weight, based on the paste.

  The paste of the present invention is prepared by mixing various components so as to have a predetermined composition, preliminarily dispersed by a mixer such as a planetary mixer, and then uniformly prepared by a dispersing and kneading means using a three-roller or the like.

  Such an inorganic powder-containing paste is applied over the entire surface of the substrate or partially applied. As a coating method, a conventional method such as a bar coater, a roll coater, a die coater, and a blade coater can be used. After the application, the product is dried using an arbitrary device such as a ventilation oven, a hot plate, and an IR drying furnace to form a coating film.

  Next, an example in which the paste manufactured by the paste manufacturing method of the present invention is applied to a display panel member will be described.

  A stripe electrode is formed on the substrate by a photolithography method using a photosensitive silver paste as a writing electrode, and a dielectric paste is applied to the substrate, and then baked at 500 to 600 ° C. to form a dielectric layer. To form

  Further, a pattern is formed on the dielectric layer by a photolithography method using a photosensitive glass paste, and then baked at 500 to 600 ° C. for 10 to 60 minutes to form a stripe-shaped partition pattern.

  The phosphor paste is formed on the partition walls thus formed. The method for forming the phosphor is not particularly limited, but includes, for example, a screen printing method, a method of discharging a phosphor paste from a die, a photosensitive paste method, and the like. A printing method is preferable because a simple and low-cost PDP can be obtained. After the phosphor paste is applied and dried, the paste is baked at, for example, 500 ° C. for 30 minutes to form a phosphor layer on the side and bottom of the partition.

  Hereinafter, the present invention will be described specifically with reference to Examples. However, the present invention is not limited to this. The concentration (%) in the examples is% by weight.

Materials used in Examples and Comparative Examples of the present invention are shown below.
Glass _{powder: Bi 2 O 3 / SiO 2} / Al 2 O 3 / ZnO / B 2 O 3 = 82/5/3/5/3 / of average particle size 2μm glass was milled composed of two glass powder filler: Average Titanium oxide polymer having a particle size of 0.5 μm (1): ethyl cellulose (N-50 manufactured by Hercules)
Polymer (2): "Cyclomer" P (ACA250, manufactured by Daicel Chemical Industries, Ltd.)
Organic solvent (1): benzyl alcohol Organic solvent (2): butyl carbitol acetate monomer: dipentaerythritol hexaacrylate Photopolymerization initiator: benzophenone antioxidant: 1,6-hexanediol-bis [(3,5-di -T-butyl-4-hydroxyphenyl) propionate]
Organic dye: Basic Blue 26
Plasticizer: bis (butoxyethyl) adipate.

Thixotropy-imparting agent (1): N, N'-12-hydroxystearic acid butyrene amide thixotropy-imparting agent (2): N, N'-12-hydroxystearic acid ethylenediamide thixotropy-imparting agent (3): N, N'- 12-Hydroxystearic acid hexamethylene diamide thixotropy-imparting agent (4): N, N'-12-Hydroxystearic acid xylylenediamide thixotropy-imparting agent (5): 1.2 mol of 12-hydroxystearic acid and 0.8 of palmitic acid The mol was charged into a four-necked flask, heated to 100 ° C., uniformly dissolved, and 1 mol of hexamethylenediamine was added. The temperature was gradually increased in a nitrogen gas stream, and the reaction was carried out at 200 ° C. for 7 hours. Heat and dissolve 20 parts of pale yellow fatty acid amide in 80 parts of benzyl alcohol and gradually cool. What was obtained by stirring.
Thixotropic agent (6): A. A urethane compound obtained by charging 1 mol of tolylene diisocyanate in a reaction vessel, adding dropwise 1 mol of methanol, and stirring at 40 ° C. for 4 hours. B. An amide compound obtained by charging 1 mol of xylylenediamine into a reaction vessel and dropping 1 mol of butyric acid with stirring at 80 ° C. C. After charging the same amount of xylol as the amide compound obtained in B and heating and dissolving to 100 ° C., the urethane compound obtained in A diluted with the same amount of xylol was added dropwise, and the mixture was added at 100 ° C. for 5 hours. What was obtained by aging.

Surfactant (1): polyoxyethylene cetyl ether surfactant (2): polyoxyethylene methyl dioleate surfactant (3): polyethylene glycol distearate surfactant (4): polyoxyethylene lauryl Sodium ether acetate.

(Examples 1 to 14, Comparative Examples 1 to 3)
After weighing each material at the composition and ratio shown in Table 1, they were mixed and kneaded with three rollers to obtain 14 types of pastes (pastes Nos. 1 to 17).

  The yield value and the viscosity of the obtained paste were measured using a Visco Analyzer VAR-50 manufactured by Jusco International Co., Ltd. (measuring temperature 25 ° C., test geometry 30φ / 4 ° cone was used). Further, the residue obtained by heating the thixotropic agent and the surfactant at 500 ° C. was measured using a thermogravimeter (“TGA-50”, manufactured by Shimadzu Corporation) in an air atmosphere (flow rate: 20 ml / min), 10 ° C. / The weight at 500 ° C. when the temperature was raised from 30 ° C. to 500 ° C. in minutes was measured, and the weight retention at 500 ° C. was calculated by determining the ratio to the weight at room temperature.

  Next, using a die coater (manufactured by Toray Industries, Inc.), the paste was applied onto a glass substrate (PD-200; manufactured by Asahi Glass Co., Ltd.) having a size of 340 × 260 × 2.8 mm while changing the application speed. The coating speed until the inside could not be uniformly coated was examined.

  Next, the back plate of an AC (AC) type plasma display panel was formed using a glass substrate (PD-200; manufactured by Asahi Glass Co., Ltd.) having a size of 340 × 260 × 2.8 mm.

  A stripe electrode having a pitch of 140 μm, a line width of 60 μm, and a thickness of 4 μm after firing was formed on the substrate by a photolithography method using a photosensitive silver paste as a writing electrode. After applying a dielectric paste to this substrate, it was baked at 550 ° C. to form a dielectric layer having a thickness of 10 μm.

  Further, using the above paste on the dielectric layer, through a subtractive mask layer formed by a photolithographic method, by sandblasting, after pattern formation, baking at 570 ° C. for 15 minutes, pitch 140 μm, line width 20 μm, high A 100 μm-striped partition pattern was formed.

  The phosphor paste of each color was applied and baked (500 ° C., 30 minutes) to the partition walls thus formed by using a screen printing method to form a phosphor layer on the side and bottom of the partition walls.

  Next, a front plate was produced by the following steps. First, an ITO was formed on the same glass substrate as the back plate by a sputtering method, a resist was applied, and a transparent electrode having a thickness of 0.1 μm and a line width of 200 μm was formed by exposure, development, and etching. Further, a bus electrode having a thickness of 10 μm was formed after firing by a photolithography method using a photosensitive silver paste composed of black silver powder. Electrodes having a pitch of 140 μm and a line width of 60 μm were prepared.

  Further, a transparent dielectric paste was applied to a thickness of 20 μm on the front plate on which the electrodes were formed, and baked at 430 ° C. for 20 minutes. Next, an MgO film having a thickness of 0.5 μm was formed using an electron beam evaporator so as to uniformly cover the formed transparent electrode, black electrode, and dielectric layer, thereby completing the front plate.

  After the obtained front glass substrate was bonded and sealed to the above-mentioned rear glass substrate, a discharge gas was sealed therein, and a driving circuit was joined thereto to produce a plasma display (PDP). A display was observed by applying a voltage to the panel.

  Table 2 shows the yield values of the pastes used in Examples 1 to 14 and Comparative Examples 1 to 3, the viscosity showing the yield value, the viscosity exceeding the yield value, the thixotropic agent / surfactant ratio, the thixotropic agent and the surfactant. The coating residue, the coating speed, the coating state, and the display characteristics of the PDP until the uniform coating on the substrate surface becomes impossible can be summarized. FIG. 1 shows a flow characteristic diagram of the paste used in Example 1 and Comparative Example 1.

  The pastes obtained in Examples 1 to 10 and 14 had good coatability and could be coated at high speed. The display characteristics of the PDP were also good.

  The pastes obtained in Examples 11 to 12 also had good coatability and could be coated at high speed, but the display characteristics of the PDP were slightly poor due to the high weight retention of the thixotropic agent and the surfactant. Was.

  In Comparative Example 1, the viscosity exceeding the yield value was high, and high-speed coating was not possible. Further, the coating state and the display characteristics were poor.

  In Comparative Example 2, although high-speed coating was possible, the shape could not be maintained after coating because there was no yield value, and the coating state was poor. In addition, the display characteristics of the PDP also showed display defects due to coating defects.

  In Comparative Example 3, the viscosity at the time of showing the yield value was high, and the viscosity exceeding the yield value was too high to apply.

It is a flow characteristic figure of the paste concerning the present invention.

Claims (12)

A paste comprising an inorganic powder and an organic component, wherein the paste has a yield value and a viscosity at which the paste exhibits a yield value is in a range of 200 to 20,000 [Pa · s]. The paste according to claim 1, wherein the yield value is in a range of 0 to 2 [Pa], and the viscosity exceeding the yield value is in a range of 5 to 50 [Pa · s]. 3. The paste according to claim 1, wherein the paste contains a thixotropic agent (A) and a surfactant (B). The paste according to claim 3, wherein the ratio of the thixotropic agent (A) to the surfactant (B) is in the range shown below.
A / B = 0.04 to 120 The paste according to claim 3 or 4, wherein when the thixotropy-imparting agent is heated from 30 ° C to 500 ° C at a rate of 10 ° C / min, the weight retention at 500 ° C is 1% by weight or less. The paste according to any one of claims 3 to 5, wherein the thixotropic agent is an aliphatic amide compound. Fatty acid amide obtained by reacting hydroxystearic acid and alkylenediamine with a thixotropic agent, aliphatic amide obtained by reacting a mixture of hydroxystearic acid and linear fatty acid with alkylenediamine, isocyanate of urethane compound and aliphatic amide compound The paste according to any one of claims 3 to 5, wherein the paste is at least one selected from urea compounds obtained by reacting a residue with an amine residue. The weight retention at 500 ° C. when the temperature of the surfactant is raised from 30 ° C. to 500 ° C. at 10 ° C./minute is 1% by weight or less. Paste. The paste according to any one of claims 1 to 8, wherein the content of the inorganic powder in the paste is in the range of 35 to 95% by weight. The paste according to any one of claims 1 to 9, wherein the inorganic powder is glass. The paste according to claim 1, wherein the paste contains a photosensitive organic component. A method for producing a display panel member, comprising a step of applying a paste on a substrate and drying the paste, wherein the paste according to any one of claims 1 to 11 is used as the paste. Production method.

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