JP2004306027A - Production apparatus of paste and production method of paste - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To dissolve various problems in qualities, production cost and operating environments, such that an operating environments grows worse due to vaporization of a solvent from a paste, such processes that rearrangement of viscosity due to a changing in viscosity increase, a foreign material is mixed from an operating environment and a dispersion fault originates from an unevenness of a gap of rolls. <P>SOLUTION: A production apparatus of a paste has a rotor and a roller in a cylindrical vessel, wherein the rotor is driven and the roller is rotated and revolved while contacting an inner wall of the cylindrical vessel to knead the paste injected between the roller and the inner wall of the cylindrical vessel. The production apparatus is constituted of a material wherein at least any one of the inner wall of the cylindrical vessel, the rotor and the roller has a density of 3.5-6.0 g/cm<SP>3</SP>and a Vickers hardness of ≥1,000 kgf/cm<SP>2</SP>. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a paste manufacturing apparatus and a paste manufacturing method, and more particularly to a display paste manufacturing apparatus.

  2. Description of the Related Art As a display that can be used for a thin and large-sized television, a plasma display panel (hereinafter abbreviated as PDP) has attracted attention. In a PDP, for example, a plurality of sustain electrodes forming a pair are formed of a material such as silver, chromium, aluminum, and nickel on a glass substrate on a front plate side serving as a display surface. Further, a dielectric layer mainly composed of glass is formed with a thickness of 20 to 50 μm to cover the sustain electrode, and an MgO layer is formed to cover the dielectric layer. On the other hand, a plurality of address electrodes are formed in stripes on the glass substrate on the back plate side, and a dielectric layer mainly composed of glass is formed so as to cover the address electrodes. A partition for dividing discharge cells is formed on the dielectric layer, and a phosphor layer is formed in a discharge space formed by the partition and the dielectric layer. In a PDP capable of full-color display, the phosphor layer is formed of one that emits light of each color of RGB. The front plate and the back plate are sealed so that the sustain electrodes of the glass plate on the front plate and the address electrodes on the back plate are orthogonal to each other, and are formed of helium, neon, xenon, etc. in the gap between those substrates. A rare gas is sealed to form PDP. Since the pixel cell is formed around the intersection of the scan electrode and the address electrode, the PDP has a plurality of pixel cells, and an image can be displayed.

  For such electrodes, dielectrics, partition walls, and phosphor layers, a paste in which an inorganic powder such as a metal powder, a glass powder, and a phosphor powder is dispersed in a binder resin is generally used. As a method for dispersing the inorganic powder in the binder resin, a roll mill such as a three-roller or a sand mill or a media disperser has been widely used.

  However, the three rollers have various problems in quality, manufacturing cost, and work environment because the apparatus is an open system and a batch type. For example, the working environment is deteriorated due to evaporation of the solvent from the paste, the number of processes is increased, such as adjusting the viscosity again due to a change in viscosity, foreign matter is mixed in from the working environment, and three rollers are used for continuous processing. If the diameter of the roll is increased and the roll length is increased to increase the processing amount, problems such as heavy equipment and poor dispersion due to uneven roll gaps are encountered. is there.

  As an alternative to the batch type three rollers in these open systems, there is a sand mill. The sand mill can have a closed structure and can be continuously processed. However, when used for dispersing a PDP paste, it is difficult to control the pulverization conditions, and it is difficult to apply the method to the production of a PDP paste. Specifically, for example, there is a problem that a decrease in luminance due to a change in the particle size of the phosphor powder or a change in the particle size distribution of the metal powder or the glass powder occurs, resulting in a change in the photosensitive characteristics of the photosensitive paste. Further, since the paste for PDP contains a large amount of inorganic powder, the paste has a viscosity of tens of thousands of mPa · s, and the medium is concentrated on a screen or a gap separator disposed at an outlet portion of a sand mill, causing clogging. There was also a problem.

  Therefore, as an alternative to these, a rotor and a roller are arranged in a cylindrical container, the rotor is driven, the roller revolves around itself while being in contact with the inner wall of the cylindrical container, and the paste injected between the roller and the inner wall of the cylindrical container is removed. A dispersing machine for kneading has been proposed (for example, see Patent Document 1).

  When this disperser is used, problems such as deterioration of the working environment and change in viscosity due to evaporation of the solvent from the paste, which are disadvantages of the three rolls due to the closed structure, are reduced.

  In addition, when using this disperser, it is difficult to control the grinding conditions, which was a drawback of the sand mill, and specifically, for example, a decrease in luminance due to a change in the particle size of the phosphor powder and a particle size distribution of the metal powder and the glass powder. The problem that a change occurs and causes a change in the photosensitive characteristics of the photosensitive paste is reduced.

However, in the process of performing the dispersion treatment, the cylindrical container, the rotor, and the roller generate friction, which causes friction, so that the paste temperature is increased and the paste is deteriorated, or the material constituting the cylindrical container, the rotor, and the roller is worn. There is a problem that the quality of the paste is reduced due to the falling off and mixing in the paste.
JP-A-11-197479 (page 2)

  Therefore, an object of the present invention is to provide a paste manufacturing apparatus and a paste manufacturing method capable of manufacturing a high-quality paste in view of the above-described problems of the related art.

In order to solve the above-mentioned problem, the present invention arranges a rotor and a roller in a cylindrical container, drives the rotor, and revolves while the roller is in contact with the inner wall of the cylindrical container. a paste production device for kneading the pastes, the inner wall of at least the cylindrical container, a rotor, and one of the rollers, density ^{3.5g / cm 3 ~6.0g / cm 3} , and, Vickers hardness 1000kgf / Mm ² or more.

  In a dispersing machine that kneads the paste injected between the roller and the inner wall of the cylindrical container, by disposing the rotor and the roller in the cylindrical container and rotating by rotating the roller while in contact with the inner wall of the cylindrical container, the rotor is driven. The density, hardness, and thermal conductivity of the inner wall of the cylindrical container, the rotor and the roller are specified to prevent the temperature rise of the paste material, thereby preventing the deterioration of the paste (viscosity increase) and the inner wall of the cylindrical container, the rotor and the roller material. Can be reduced to be mixed into the paste by abrasion, and a good quality paste and a paste manufacturing method can be provided. Panels made using these pastes have excellent lighting properties.

  As an example of a dispersing machine used for dispersing the paste of the present invention, a roller 5 is loaded in a cylindrical container 1 as shown in FIG. The apparatus shown in FIG. 2 is preferably provided with a paste supply port on one side of the cylindrical container 1 and a paste discharge port on the other side, so that continuous processing can be performed.

  Further, the dispersing machine shown in FIG. 3 in which a part of FIG. 1 is enlarged is preferable. A rotatable rotor 2 is arranged coaxially with the cylindrical container 1, and has a plurality of grooves 4 parallel to the rotation axis 3 on an outer peripheral portion of the rotor 2, and each groove 4 has at least a centrifugal force caused by rotation of the rotor 2. A small gap 6 is formed between “the inner wall of the groove 4 and the roller”, and the rollers 5 that respectively revolve inside the cylindrical container 1 while rotating in contact with the inner wall surface of the cylindrical container 1 are loaded. This is because the unpasted paste does not pass through (short pass) the paste, and the whole paste can be uniformly dispersed.

  When the rotor 2 rotates in the cylindrical container 1, the centrifugal force causes the roller 5 loaded in each groove 4 of the rotor 2 to abut at least the inner wall surface of the cylindrical container 1. Revolves inside the cylindrical container 1 while rotating. Then, the paste sent from the supply port to the inside of the cylindrical container 1 is pressed by the rollers 5 against the inner wall surface of the cylindrical container 1 and extruded to the discharge port. Further, since the roller 5 is inserted into the groove 4 of the rotor 2, the rotation speed of the rotor 2 becomes the revolution speed of the roller 5. Therefore, the paste is strongly pressed against the inner wall surface of the cylindrical container 1 by the centrifugal force generated by the rotation of the rotor 2, and is repeatedly subjected to compression and shearing action.

  In this case, the region through which the paste passes is limited to the very vicinity of the inner wall surface of the cylindrical container 1. In other words, as shown in FIG. 3, the gap 7 between the inner wall surface of the cylindrical container 1 and the outer peripheral surface of the rotor 2 is a paste passage area. Then, in this specific area, the flow of the paste shown by the arrow in FIG. 3 always occurs due to the stirring action of the rotor 2. As a result, the paste is constantly circulated in this specific area and is uniformly dispersed.

  Further, the disperser used in the present invention will be described with reference to FIG. Due to the centrifugal force generated by the rotation of the rotor 2, a gap 6 is formed between the inner wall of the groove 4 and the outer peripheral surface of the roller 5. Severe shearing action.

  Here, it is preferable that a large number of the grooves 4 are arranged radially from the viewpoint of improving the dispersibility. Since a large number of grooves 4 are arranged radially, the paste is uniformly compressed and sheared by the rollers 5 inserted in the grooves 4. Further, it is preferable that a plurality of the rollers 5 are inserted into one groove 4 in close contact with each other in a direction parallel to the rotation axis. Since the plurality of rollers 5 are closely inserted into one groove 4 in a direction parallel to the rotation axis, the entire inner wall surface of the cylindrical container 1 can be a dispersion area. Each of the loaded rollers is subjected to independent compression and shearing action, and a paste with improved dispersibility can be obtained.

These dispersing machines, at least the cylindrical vessel 1 inner wall, either of the material constituting the rotor 2 and the roller 5 is a density of ^{3.5g / cm 3 ~6.0g / cm 3} , and, Vickers hardness 1000kgf / Mm ² or more. Further, the heat conductivity is 0. It is preferable to be made of a material having a temperature of at least 01 cal / cm · sec · ° C.

When the density of the roller is lower than 3.5 g / cm ^{3, the} load applied to the roller by the rotation of the rotor is not sufficient, and the dispersion efficiency is reduced. When the density is higher than 6.0 g / cm ³ , the load applied to the roller is high. If it is too much, the material constituting the rotor and the rollers will be significantly worn, and abrasion powder will be mixed into the paste, deteriorating the paste quality or damaging the rotor.
If the Vickers hardness is lower than 1000 kgf / mm ² , the material constituting the inner wall of the cylindrical container, the rotor and the rollers during the dispersing process is significantly worn, and wear powder is mixed into the paste to lower the paste quality.

  When the thermal conductivity is less than 0.01 cal / cm · sec · ° C., the material constituting the rotor and the roller can be obtained even if a means for cooling the material constituting the inner wall of the cylindrical container, the rotor and the roller is taken in the process of performing the dispersion treatment. The temperature of the paste rises, and the paste temperature also rises.

  Examples of a material satisfying the above conditions include a ceramic material such as alumina. Further, among the ceramic materials, those in which the ceramic material contains at least zirconia are preferable.

  Such a ceramic material includes a mixture of alumina and zirconia. Further, the mixing ratio (% by weight) of zirconia / alumina = 5/95 to 95/5 is preferable. If the content of zirconia is less than 5% by weight, it becomes brittle, and if it exceeds 95% by weight, the thermal conductivity decreases, which is not preferable.

  Further, as shown in 12 and 13 of FIG. 2, at least the inner wall and / or the rotor of the cylindrical container of the dispersing machine has a structure capable of introducing a cooling medium, and the paste is controlled while controlling the paste temperature by introducing the cooling medium. Dispersing is preferred.

  In the case where the paste composition is a reactive paste, introduction of a refrigerant can prevent the paste temperature from becoming higher than a certain temperature, thereby preventing the reaction from proceeding and lowering the paste quality. Alternatively, when the paste has a high viscosity and is difficult to disperse, the paste viscosity can be reduced by introducing a heating medium to facilitate the dispersion.

The roller charged into the cylindrical container preferably has a diameter of 5 to 50 mm and a length of 10 to 100 mm, more preferably a diameter of 6 to 30 mm and a length of 15 to 80 mm. It is. When the roller is in this range, a paste having excellent dispersibility can be obtained. In order to obtain good dispersibility, the peripheral speed of the rotor is preferably 1.0 to 10 m / s.

  The viscosity of the paste from which an appropriate shearing force can be obtained in a range satisfying these conditions is preferably in the range of 5,000 to 100,000 mPas · sec. In the present disperser, it is preferable to continuously supply the paste to the supply side of the disperser to perform a continuous dispersion process.

  As a method of continuous processing, a method of supplying a paste to a paste supply port using a metering pump is preferable. Specific examples of the metering pump include a single-stage centrifugal pump, a multi-stage centrifugal pump, a single-stage turbine pump, a centrifugal pump such as a borehole pump, an axial-flow pump, a propeller pump such as a mixed-flow pump, a single-stage centrifugal pump, and a multi-stage vortex pump. Reciprocating pumps such as viscous pump, horizontal piston pump, rigid piston pump, horizontal type pump, horizontal type pump, diaphragm pump, tube pump, wing pump, etc., external gear pump, internal gear pump, eccentric screw pump, etc. Rotary pumps such as vane pumps and roller pumps are exemplified. In order to supply a paste having a high viscosity, a diaphragm pump or an eccentric screw pump is preferable. By using a metering pump, a paste having stable dispersibility can be obtained.

  Further, it is preferable that the liquid contact portion of these pumps is made of a ceramic material such as alumina, zirconia, an alumina / zirconia mixture, silicon carbide, and sialon because wear resistance can be improved.

  The paste in the present invention is mainly composed of an inorganic powder and a binder resin. 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, phosphor powder, and metal powder.

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 diameter of the glass powder is selected in consideration of the line width and height of the partition wall to be produced. The central 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 phosphor powder, for example, in red, Y ₂ O ₃ : Eu, YVO ₄ : Eu, (Y, Gd) BO ₃ : Eu, Y ₂ O ₃ S: Eu, γ-Zn ₃ (PO ₄ ) ₂ : Mn, (ZnCd) S: Ag + In ₂ O _{3 and the} like. In green, Zn ₂ GeO ₂ : M, BaAl ₁₂ O ₁₉ : Mn, Zn ₂ SiO ₄ : Mn, LaPO ₄ : Tb, ZnS: Cu, Al, ZnS: Au, Cu, Al, (ZnCd) S: Cu, _{Al, Zn 2 SiO 4: Mn} , As, Y 3 Al 5 O 12: Ce, CeMgAl 11 O 19: Tb, Gd 2 O 2 S: Tb, Y 3 Al 5 O 12: Tb, ZnO: Zn , etc. mentioned Can be The _{blue, Sr 5 (PO 4) 3} Cl: Eu, BaMgAl 14 O 23: Eu, BaMgAl 16 O 27: Eu, BaMg 2 Al 14 O 24: Eu, ZnS: Ag + red pigment, Y ₂ SiO _3: Ce, etc. Is raised.

Further, at least one element selected from the group consisting of thulium (Tm), terbium (Tb) and europium (Eu), and at least one element selected from yttrium (Y), gadolinium (Gd) and lutetium (Lu) It is also possible to use a rare earth tantalate phosphor in which a rare earth element constituting a base is substituted. Preferably, the rare earth tantalate phosphor is a europium-activated yttrium tantalate phosphor represented by a composition formula Y ₁ -XE _x TaO ₄ (where X is approximately 0.005 to 0.1). It is. For the red phosphor, europium-activated yttrium tantalate is preferably used, and for the green phosphor, a rare earth tantalate phosphor is represented by a composition formula Y _1-X Tb _x TaO ₄ (where X is approximately 0. 001-0.2) is preferably used. In addition, the blue phosphor includes a thulium-activated tantalate represented by Y _1-x Tm _x TaO ₄ (where X is approximately 0.001 to 0.2). Yttrium is preferably used.

  The phosphor powder used in the phosphor paste of the present invention has an area average diameter (Ds) of 1.0 to 2.5 μm, a center diameter (Dv) of a volume-based distribution of 1.8 to 4.5 μm, and Ds / Ds / Dv. Dv is preferably 1.2 to 2.5, and more preferably Ds is 1.2 to 2.3 μm, Dv is 2.0 to 4.2 μm, and Ds / Dv is 1.3 to 2.3. Is within the range. Ds, Dv and Ds / Dv within this range are preferable because the filterability of the paste can be improved.

  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 binder resin in the paste of the present invention is preferably oxidized or / and decomposed or / and vaporized at the time of baking, so that no carbides remain in the inorganic substance. 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.

  Other constituents of the paste of the present invention include additive components such as organic solvents, plasticizers, antioxidants, defoamers, dispersants, leveling agents, and refractory fillers. 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.

  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 , 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. The organic solvent is preferably a good solvent for the binder resin used. Further, the selection of the solvent is made by mainly considering the volatility of the solvent and the solubility of the binder resin used. This is because if the solubility of the solvent in the binder resin is low, the viscosity of the coating liquid tends to be high even at the same solid content ratio, and the coating characteristics tend to be deteriorated.

  If the content of the organic solvent is too small, the viscosity of the phosphor paste becomes too high, so that it is difficult to remove bubbles in the material for forming the partition walls, and the leveling defect tends to cause poor smoothness of the coated surface. On the other hand, if the amount is too large, the sedimentation of the dispersed particles becomes faster, and it becomes difficult to stabilize the composition of the phosphor paste, and there is a tendency to cause problems such as requiring much energy and time for drying. The preferable content of the solvent is 35 to 65% by weight, more preferably 40 to 60% by weight in the paste.

  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.

  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.

  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.

  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 is prepared by mixing various components so as to have a predetermined composition, and then preliminarily dispersed by a mixer such as a planetary mixer, and then dispersed and kneaded by a dispersing machine in which rollers are loaded in the above-described cylindrical container. To make it homogeneous.

  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 by a screen printing method, and then baked at 500 to 600 ° C. Then, a dielectric layer is formed.

  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.

(Paste composition)
(1) Partition wall paste 52% of glass powder having an average particle diameter of 2 μm obtained by pulverizing glass mainly composed of a substance of lead oxide, boron oxide, zinc oxide, silicon oxide and barium oxide, a methyl methacrylate / methacrylic acid copolymer (weight Composition ratio 60/40, weight average molecular weight 32000) 12%, dipentaerythritol hexaacrylate 12%, benzophenone 1.94%, 1,6-hexanediol-bis [(3,5-di-t-butyl-4-) (Hydroxyphenyl) propionate] 0.05%, an organic dye (Basic Blue 7) 0.01%, and an organic solvent (propylene glycol monomethyl ether acetate) 22%.

(Paste evaluation method)
(1) Viscosity device: Field type viscometer (manufactured by Brookfield, model DV-1)
Measurement: rotation speed 3 rpm, measurement temperature 25 ° C
Judgment criterion: A high paste viscosity indicates that the paste temperature increased and the paste was altered (polymerized).

(2) Dispersing device: Grind gauge (Erichsen, 0-50 μm)
Measurement: The distribution density of the pits was observed, and the scale where the dense pits appeared was read. However, when the dense line of the stub appears in the middle of the scales or when the values of the two grooves are different, read the larger scale and paste the median of the three measurements. Of dispersion.
Judgment: A large value indicates poor dispersibility.

(3) Foreign substance measurement: After 20 kg of the dispersed paste is filtered through a 293 mmφ disk filter (filtration pressure: 0.2 MPa, filter: 500 mesh), the filter is placed in a clean container, immersed in clean acetone, and ultrasonically cleaned. Wash for 30 minutes on the machine. After washing, the washing solution was further filtered through a 25 mmφ disk filter (filtration pressure: 0.05 MPa, filter: nylon net [pore diameter 11 μm]), and the amount of foreign matters remaining on the filter was measured with a precision balance.
Judgment: A large amount of foreign matter indicates poor dispersibility or mixing of wear powder such as a cylindrical container, a roller and a rotor of a dispersing machine.

(Examples 1 to 7, Comparative Examples 1 to 3)
After a predetermined amount of each paste was measured, it was preliminarily dispersed by a planetary mixer (manufactured by Inoue Seisakusho). The conditions at this time were 60 rpm at 30 rpm. After the pre-dispersion was completed, the upper pot was set in the lower pot of the mixer, and further connected to a disperser in which a roller was loaded in a cylindrical container by a tube of 18 mmφ made of fluororesin. A pressure of 0.2 MPa was applied to the mixer pot, and the paste in the mixer pot was extruded into a cylindrical container of a disperser. The operating conditions of the disperser were 400 rpm. Subsequently, the paste after the dispersion was completed was filtered. Filtration was performed with a 293 mmφ disk filter (filtration pressure: 0.2 MPa, filter: 500 mesh).

  The processing amount of each paste was 20 kg, and the results of measuring the paste temperature, the degree of dispersion, the viscosity, and the amount of foreign substances on the disk filter after the dispersion treatment are shown in Table 1.

  Table 2 shows the density, hardness, and thermal conductivity of the materials constituting the inner wall of the cylindrical container 1, the rotor 2, and the roller 5.

  In the pastes obtained in Examples 1 to 7, the amount of foreign substances was small, and pastes having good dispersibility were obtained in a short time. In addition, when these pastes were used for coating, the coatability was good. Particularly, in Examples 1 to 4 and 7, the amount of foreign matters was small and good. In a series of steps, the pastes of Examples 1 to 7 were applied, patterned, and fired to form a panel, and the lighting performance was good.

  In Comparative Example 1, the paste temperature was increased, the paste viscosity was increased, and the applicability was poor, and a uniform applied film thickness could not be obtained. In Comparative Examples 2 and 3, the amount of foreign matter was large in each paste, and uniform application was not performed. In a series of steps, when the pastes of Comparative Examples 1 to 5 were applied, patterned, and baked to form a panel, lighting failure due to uneven film thickness and the presence of foreign matter occurred.

FIG. 2 is a cross-sectional view showing the most preferred embodiment of the disperser used in the present invention. FIG. 1 is a lateral view schematically showing a dispersing machine used in the present invention. The enlarged view of the roller part of FIG.

Explanation of reference numerals

1: cylindrical container 2: rotor 3: rotating shaft 4: groove 5: roller 6: slight gap 7: gap 11: jacket 12: cooling / heating medium introduction path a
13: Cooling medium introduction path b

Claims (10)

This is a paste production apparatus that arranges a rotor and a roller in a cylindrical container, drives the rotor, and revolves while the roller is in contact with the inner wall of the cylindrical container, thereby kneading the paste injected between the roller and the inner wall of the cylindrical container. Te, at least inner walls of the cylindrical vessel, rotor, and one of the rollers, density ^{3.5g / cm 3 ~6.0g / cm 3} , and a Vickers hardness is formed of a material is 1000 kgf / mm ² or more A paste producing apparatus. At least one of the inner wall, the rotor, and the roller of the cylindrical container has a thermal conductivity of 0. 2. The paste producing apparatus according to claim 1, wherein the paste producing apparatus is made of a material having a temperature of at least 01 cal / cm.sec..degree. The paste production apparatus according to claim 1, wherein at least one of an inner wall, a rotor, and a roller of the cylindrical container is made of a ceramic material. The paste manufacturing apparatus according to any one of claims 1 to 3, wherein the ceramic material contains at least 5% by weight of zirconia. A paste production method using the paste production apparatus according to claim 1. The paste manufacturing method according to claim 5, wherein the paste contains an inorganic powder. The paste production method according to claim 6, wherein the content of the inorganic powder in the paste is in the range of 35 to 95% by weight. The paste manufacturing method according to claim 6, wherein the inorganic powder is at least one of glass, phosphor, and metal. The paste production method according to claim 5, wherein the paste contains a compound having an unsaturated double bond. The paste production method according to any one of claims 5 to 9, wherein the paste production method is used for forming an electrode, a dielectric, a partition, and a phosphor of a display.

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