KR100981509B1 - Inorganic Powder-Containing Paste and Process for Preparing the Same, and Process for Preparing Member for Plasma Display Panel - Google Patents

Abstract

The present invention relates to a method for producing an inorganic powder-containing paste, wherein the inorganic powder-containing paste is dispersed using a disperser equipped with a roller in a cylindrical container.

According to the present invention, an inorganic powder-containing paste having a small amount of foreign matter and excellent dispersibility in a short treatment time can be provided.

Inorganic powder-containing paste, plasma display panel member, foreign matter amount, dispersibility.

Description

Inorganic Powder-Containing Paste and Process for Preparing the Same, and Process for Preparing Member for Plasma Display Panel}             

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a side view showing the outline of a disperser used in the present invention.

Fig. 2 is a cross-sectional view showing the most preferred form of the disperser roller portion used in the present invention.

3 is an enlarged view of the roller unit of FIG. 2;

4 is a cross-sectional view showing another example of the disperser roller portion.

5 is a cross-sectional view when a tapered roller bearing is used for the roller portion of the disperser.

<Explanation of symbols for the main parts of the drawings>

1: cylindrical container

2: rotor

3: axis of rotation

4: groove

5: roller

6: small gap between roller and rotor                 

7: clearance between the inner wall of the cylindrical vessel and the rotor

8: container inner wall

9: bearing roller

10: tapered roller bearing

11: paste outlet

12: paste supply port

13: metering pump

14: Spare Disperser

The present invention relates to an inorganic powder-containing paste and a method for producing the same, which are suitable for producing a member for a plasma display panel.

Plasma display panels (hereinafter referred to as PDPs) have attracted attention as displays that can be used in thin and large televisions. PDP mainly consists of front panel and back panel. On the glass substrate on the front plate side serving as the display surface, a plurality of pairs of sustain electrodes are formed of a material such as silver, chromium, aluminum, or nickel. In addition, a dielectric layer composed mainly of glass is formed to a thickness of 20 to 50 µm so as to cover the sustain electrode. In addition, an MgO layer is formed so as to cover the dielectric layer.

On the other hand, many address electrodes are formed in stripe form on the glass substrate of the back plate side. Further, a dielectric layer composed mainly of glass is formed to cover the address electrode. On the dielectric layer, a partition wall for partitioning discharge cells is formed, and a phosphor layer is formed in a discharge space formed of the partition wall and the dielectric layer. In the case of a PDP capable of full color display, the phosphor layer is composed of phosphors that emit light in each of red, green, and blue colors.

The front plate and the back plate are sealed so that the sustain electrode of the glass substrate on the front plate side and the address electrode on the back plate side are orthogonal to each other, and a rare gas composed of helium, neon, xenon, or the like is sealed in the gap between these substrates to form a PDP. Since the pixel cells are formed around the intersections of the scan electrodes and the address electrodes, the PDP has a plurality of pixel cells, and image display is possible.

When forming such an electrode, a dielectric, a partition, and a phosphor layer, the paste which disperse | distributed inorganic powder, such as metal powder, glass powder, and phosphor powder, to binder resin is used normally. As a method of disperse | distributing these inorganic powders to binder resin, roll mills, such as a 3-axis roller, are conventionally used.

However, the three-axis roller has various problems in terms of quality, manufacturing cost, working environment, etc. because the apparatus is an open system and a batch type. The first is a problem of deterioration of the working environment due to evaporation of the solvent from the paste. Second, since the viscosity changes, the process of performing viscosity adjustment again, etc. increases. Third, foreign matters are mixed in the surrounding work environment. Fourth, in order to process continuously, it is a problem that it is difficult to connect with the front-back process of a triaxial roller. Fifthly, in order to increase the amount of processing, the roll diameter must be increased and the roll length must be increased, resulting in heavy equipment or uneven roll spacing, resulting in poor dispersion of the paste.

As a substitute for such an open and batch triaxial roller, a sand mill is disclosed in Japanese Utility Model Laid-Open No. 7-7740 (first to fourth pages). The sand mill can have a closed structure and can be subjected to continuous processing. However, when the sand mill is used for dispersing the PDP paste, it is difficult to control the grinding conditions, which makes it difficult to apply the PDP paste. Specifically, there have been problems such as a decrease in luminance due to a change in the particle size of the phosphor powder, a change in the particle size distribution of the metal powder or the glass powder, and a change in the photosensitive characteristics of the photosensitive paste. In addition, since the PDP paste contains a large amount of inorganic powder, the paste has a viscosity of tens of thousands of mPa · s, and the media cannot concentrate on the screen or gap separator disposed at the outlet of the sand mill, thereby preventing operation. .

Moreover, as another dispersing apparatus which can be made into a sealed structure and can also be processed continuously, a roller mill is disclosed by Unexamined-Japanese-Patent No. 11-197479. However, when used for dispersion of PDP paste, there has been a problem that the internal pressure of the container rises and operation is impossible.

In view of the problems of the prior art, an object of the present invention is to provide a high quality and low cost inorganic powder-containing paste.                         

Another object of the present invention is to provide a method for producing a high quality and low cost plasma display panel member using such an inorganic powder-containing paste.

In order to solve the said subject, this invention consists of the following structures.

(1) A method for producing an inorganic powder-containing paste, wherein the inorganic powder-containing paste is dispersed using a disperser equipped with a roller in a cylindrical container.

(2) The method for producing an inorganic powder-containing paste according to (1), wherein the disperser is a disperser having a paste supply port at one end of the cylindrical container and a paste discharge port at the other end.

(3) The method for producing an inorganic powder-containing paste according to (2), wherein the inorganic powder-containing paste is supplied to the paste supply port using a metering pump.

(4) In (1), the disperser arranges the rotor rotatable in the cylindrical container, has a plurality of grooves parallel to the rotation axis in the outer peripheral portion of the rotor, and in each groove at least the inner wall of the groove by centrifugal force by the rotation of the rotor. And a gap formed between the rollers and the rollers, which are in contact with the inner wall of the cylindrical container and are rotated while rotating in the cylindrical container, respectively.

(5) The method for producing an inorganic powder-containing paste according to (1), wherein the roller has a diameter of 5 to 50 mm and a length of 10 to 100 mm.

(6) The method for producing an inorganic powder-containing paste according to (1), wherein the inner wall and the roller of the cylindrical container of the disperser are made of a ceramic material.

(7) The method for producing an inorganic powder-containing paste according to (1), wherein the viscosity of the inorganic powder-containing paste is 10,000 to 80,000 mPa · s.

(8) The method for producing an inorganic powder-containing paste according to (1), wherein the content of the inorganic powder in the inorganic powder-containing paste is in the range of 30 to 95% by weight.

(9) The method for producing an inorganic powder-containing paste according to (1), wherein the inorganic powder is one or two or more selected from glass, refractory fillers, phosphors, metals, and metal oxides.

(10) The method for producing an inorganic powder-containing paste according to (1), wherein the inorganic powder-containing paste contains a compound having an unsaturated double bond.

(11) An inorganic powder-containing paste prepared by the method for producing an inorganic powder-containing paste according to any one of (1) to (10).

(12) The inorganic powder-containing paste according to (11), which is used for formation of electrodes, black stripes, dielectrics, partitions, and phosphors of a display.

(13) The inorganic powder-containing paste according to (11), wherein the amount of foreign matter in the paste is 15 mg or less.

(14) A method for producing a member for a plasma display panel, comprising the step of applying an inorganic powder-containing paste on at least a substrate, wherein the inorganic powder-containing paste is an inorganic powder-containing paste according to (11). The manufacturing method of the member for ray panels.

Embodiments of the Invention

Hereinafter, the present invention will be described in more detail.

As an example of the disperser used for disperse | distributing the inorganic powder containing paste of this invention, the roller 5 is attached to the cylindrical container 1 as shown in FIG. Since the apparatus of FIG. 1 is equipped with the paste supply port 12 in one side of the cylindrical container 1, and the paste discharge port 11 in the other side, continuous processing is attained. Here, an inorganic powder containing paste means what consists mainly of an inorganic powder and binder resin.

As a method of a continuous process, the method of supplying a paste using the metering pump 13 to the paste supply port 12 is preferable. Specific examples of the metering pump 13 include centrifugal pumps, propeller pumps, viscous pumps, reciprocating pumps, rotary pumps, and the like. The centrifugal pump includes a single stage spiral winding pump, a multistage spiral winding pump, a single stage turbine pump, a borehole pump, and the like. Propeller pumps include an axial flow pump, a four-flow pump, and the like. Examples of the viscous pump include a single stage vortex pump and a multistage vortex pump. Examples of the reciprocating pump include a horizontal piston pump, a shoulder piston pump, a horizontal plunger pump, a shoulder plunger pump, a diaphragm pump, a tube pump, and a wing pump. Rotary pumps include an external gear pump, an internal gear pump, an eccentric screw pump, a vane pump, a roller pump, and the like. Among these, a diaphragm pump and an eccentric screw pump are preferable in order to supply a paste with high viscosity as used in the present invention. By using the metering pump 13, a paste with stable dispersibility can be obtained. In addition, it is preferable that the liquid contact portion is manufactured or coated with a ceramic material such as zirconia or cylon because the wear resistance can be improved. In addition, it is preferable to disperse | distribute with the preliminary disperser 14 before supplying a paste to the metering pump 13.

Moreover, it is preferable that the disperser of this invention has a structure shown to FIG. 2, FIG. As shown in FIG. 2, the rotor 2 rotatable on the same axis as the cylindrical container 1 is arrange | positioned, The outer peripheral part of the rotor 2 has many grooves 4 parallel to the rotating shaft 3, and each groove | channel In (4), a small gap 6 is formed between at least the inner wall of the groove 4 and the roller by the centrifugal force by the rotation of the rotor 2. In addition, since the rollers 5 which rotate in contact with the inner wall surface of the cylindrical container 1 and revolve in the cylindrical container 1 are respectively mounted in the grooves 4, the undispersed paste does not pass (short pass). The whole inorganic powder containing paste can be disperse | distributed uniformly.

As a roller mounted in a cylindrical container, it is preferable that the diameter is the range of 5-50 mm, and the length is 10-100 mm, More preferably, it is the range of 6-30 mm and 15-80 mm in length. When the roller is in this range, a paste excellent in dispersibility can be obtained.

In the disperser, when the rotor 2 rotates in the cylindrical container 1, the roller 5 mounted in each groove 4 of the rotor 2 by the centrifugal force is at least an inner wall surface of the cylindrical container 1. They rotate in contact with each other and revolve in the cylindrical container 1. In addition, the paste sent from the supply port into the cylindrical container 1 is pressed by the roller 5 to the inner wall surface of the cylindrical container 1 and extruded into the discharge port. In addition, since the roller 5 is inserted in the groove 4 of the rotor 2, the rotation speed of the rotor 2 becomes the revolution speed of the roller 5. Therefore, by the centrifugal force by the rotation of the rotor 2, the paste is strongly pressed against the inner wall surface of the cylindrical container 1, and repeatedly receives a compression and a shearing action.

In this case, the region through which the paste passes is limited to almost the periphery of the inner wall surface of the cylindrical container 1. In other words, as shown in FIG. 3, the portion of the gap 7 between the inner wall surface of the cylindrical container 1 and the outer circumferential surface of the rotor 2 is a passage area of the paste. Moreover, in this specific area | region, the flow phenomenon of the paste shown by the arrow of FIG. 3 always arises by the stirring action of the rotor 2. As a result, the paste is always circulated in this specific area and uniformly dispersed.

In addition, the disperser used by this invention is demonstrated using FIG. Due to the centrifugal force by the rotation of the rotor 2, a gap 6 is formed between the inner wall of the groove 4 and the outer circumferential surface of the roller 5, and since the paste also enters the gap 6, The rotating roller 5 also receives a strong shearing action here.

Here, it is preferable from the viewpoint of dispersibility improvement that many grooves 4 are disposed radially. Since many grooves 4 are disposed radially, the paste is uniformly compressed and sheared by the rollers 5 mounted on the grooves 4. Moreover, it is preferable that many rollers 5 are closely attached to one groove 4 in the direction parallel to a rotating shaft. The roller 5 is attached to the one groove 4 in close contact with and in the direction parallel to the rotation axis, so that the entire inner wall surface of the cylindrical container 1 can be a dispersion area, and in one groove 4 Since each mounted roller receives independent compression and shearing actions, a paste with improved dispersibility can be obtained.

Moreover, even if it is a disperser other than the above as shown, if a roller is attached to a cylindrical container, it can be used. For example, as shown in FIG. 4, the roller 5 rotates and rotates inside the cylindrical container 1 to provide a compression and shearing action to the paste between the container inner wall 8. Further, for example, a plurality of tapered roller bearings 10 are arranged in a cylindrical container as shown in FIG. 5 to perform dispersion by pressurization on a rolling surface by rolling of the bearing rollers 9.

Such a disperser is preferable because at least the inner wall of the cylindrical container and the roller are made of ceramic materials such as zirconia and cylon, since they can improve wear resistance.

The disperser in the present invention may be a horizontal type having a paste supply port 12 on one side of the cylindrical container 1 and a paste discharge port 11 on the other side, as shown in FIG. It may be of the vertical type having 12) at the lower side and the paste discharge port 11 at the upper side. By setting it as a vertical type, since the bubble which enters in an inorganic powder containing paste can be reduced, the defoaming process time after a dispersion process can be shortened.

The inorganic powder containing paste in this invention mainly consists of an inorganic powder and binder resin. It is preferable that content of an inorganic powder is 30 to 95 weight%, and also 32 to 90 weight% is small in the shrinkage rate at the time of baking in a PDP manufacturing process, and small in the shape change by baking.                     

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 of 50 to 400 ° C. of 50 × 10 ⁻⁷ to 100 × 10 ⁻⁷ . In addition, by blending silicon oxide in the range of 3 to 60% by weight and boron oxide in the range of 5 to 50% by weight, electrical, mechanical and thermal properties required as partition walls such as electrical insulation, strength, coefficient of thermal expansion, compactness of the insulating layer, and the like. Can improve. As glass powder in this invention, what consists mainly of low melting glass powder is preferable. It is preferable that the glass transition temperature of low melting glass powder is 430-500 degreeC, and a glass softening point is 470-620 degreeC. When the glass transition temperature and the glass softening point are in this range, the distortion of the substrate is small at the time of firing, and a dense partition layer is obtained. The particle diameter of the glass powder is selected in consideration of the line width or height of the partition to be manufactured, 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 4 cm ² / g. It is preferable.

As the phosphor powder, for example, red is 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 And (ZnCd) S: Ag + In ₂ O ₃ . As 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 0 ₁₂ : Ce, CeMgAl ₁₁ O ₁₉ : Tb, Gd ₂ O ₂ S: Tb, Y ₃ Al ₅ 0 ₁₂ : Tb, ZnO: Zn and the like. have. As 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, and the like. Can be mentioned.

In addition, at least one elementary constituent rare earth selected from yttrium (Y), gadolinium (Gd) and lutetium (Lu) with at least one element selected from the group consisting of thulium (Tm), terbium (Tb) and europium (Eu) Tantalic acid rare earth phosphors substituted with an element can also be used. Preferably, the tantalum rare earth phosphor is an active yttrium tantalum phosphorus with europium represented by the composition formula Y _1-X Eu _X TaO ₄ , wherein X is about 0.005 to 0.1. Activated yttrium tantalate with europium is preferably used as the red phosphor, and as the green phosphor, terbium in which the tantalum rare earth phosphor is represented by the composition formula Y _1-X Tb _X TaO ₄ (wherein X is about 0.001 to 0.2) Adhesion activated yttrium tantalum is preferably used. As the blue phosphor, active thallium tantalum with thulium, in which the tantalum rare earth phosphor is represented by Y _1-X Tm _X TaO ₄ (wherein X is about 0.001 to 0.2), is preferably used.

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

As a metal powder, what contains 1 or more types chosen from the group of Ag, Au, Pd, Ni, Cu, Al, and Pt can be used. These can also be used in any one of single, alloy, and mixed powder. As a particle diameter of a metal powder, it is preferable that the center diameter of a volume reference distribution is 0.7-6 micrometers. More preferably, it is 1.3-4 micrometers. By the particle diameter being in this range, the formation of a fine fine pattern becomes possible.

The binder resin in the paste of the present invention is preferably oxidized and / or decomposed and / or vaporized at the time of firing so that carbides do not remain in the inorganic substance, and ethyl cellulose, methyl cellulose, nitrocellulose, cellulose acetate, cellulose Cellulose resins such as propionate and cellulose butyrate, or methyl (meth) acrylate, ethyl (meth) acrylate, normal butyl (meth) acrylate, isobutyl (meth) acrylate, and isopropyl (meth) acrylic Acrylic resins composed of polymers or copolymers such as acrylate, 2-ethylmethyl (meth) acrylate and 2-hydroxyl ethyl (meth) acrylate, poly-α-methylsulfone, polyvinyl alcohol, polybutene and the like are preferably used. Used. It is preferable that content of binder resin in the paste of this invention is 5-65 weight%, and also 10-60 weight%.

Other components in the paste of the present invention include additive components such as an organic solvent, a plasticizer, an antioxidant, an antifoaming agent, a dispersant, and a leveling agent, and a refractory filler. Moreover, especially when using the paste of this invention as a photosensitive paste, additive components, such as a photosensitive component, a photoinitiator, a sensitizer, a ultraviolet absorber, and a polymerization inhibitor, can be added, such as a photosensitive polymer, a photosensitive oligomer, and a photosensitive monomer. .

An organic solvent is used to adjust the viscosity at the time of apply | coating a paste to a board | substrate according to a coating method. As the organic solvent used at this time, diethylene glycol monobutyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol mono-2-ethyl hexyl ether, diethylene glycol mono-2-ethylhexyl ether, 2,2,4- Trimethyl-1,3-pentanediol monoisobutylate, 2,2,4-trimethyl-1,3-pentanedioldiisobutylate, 2-ethyl-1,3-hexanediol, terpineol, benzyl alcohol, 1-butoxy-2-propane, 1,2-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-methylbutylacetate, 2-methoxyethanol, 2 Ethoxyethanol, 2- (methoxymethoxy) ethanol, 2-isopropoxyethanol, 2-butoxyethanol, 2- (isopentyloxy) ethanol, 2- (hexyloxy) ethanol, 2-phenoxy Ethanol, 2- (benzyloxy) ethanol, benzyl alcohol, green Furyl alcohol, tetrafurfuryl alcohol, 2,2'-dihydroxydiethyl 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-diethoxyethane, 1,2-dibutoxyethane, cyclohexanone, methyl acetate , Ethyl acetate, propyl acetate, isopropyl acetate, butyl acetate, 1-methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, cyclohexyl acetate, benzyl acetate, hexane, cyclohexane, methyl ethyl ketone, 2- Pentanone, 3-pentanone, 2-hexanone, methyl isobutyl ketone, 2-heptanone, 4-heptanone, diisobutyl ketone, etc. are mentioned. It is preferable that the organic solvent is a good solvent with respect to the binder resin used. In addition, the solvent is selected in consideration of the volatility of the solvent and the solubility of the binder resin used. If the solubility of the binder resin in the solvent is low, the viscosity of the coating liquid increases even if the solid content ratio is the same.

When the content rate of the organic solvent is too small, the viscosity of the phosphor paste becomes high, and it is difficult to remove bubbles in the partition forming material, and the smoothness of the coated surface tends to be poor due to poor leveling. On the contrary, in too many cases, the settling of the dispersing particles is accelerated, which makes it difficult to stabilize the composition of the phosphor paste, and it tends to cause problems such as requiring a lot of energy and time for drying. To 65% by weight, more preferably 40 to 60% by weight.

A refractory filler is added preferably in order to stabilize the shape at the time of baking. As a refractory filler, what is not softened at the baking temperature of about 500-650 degreeC can be used widely, and ceramic powders, such as high melting glass, alumina, magnesia, calcia, cordierite, silica, mullite, zircon, zirconia, are illustrated can do. When the partition is made dark in order to reduce the reflection of external light of the PDP and to raise the practical contrast, Co-Cr-Fe, Co-Mn-Fe, Co-Fe-Mn-Al, Co- are used as fire-resistant black pigments. Pigments, such as Ni-Cr-Fe, Co-Ni-Mn-Cr-Fe, Co-Ni-Al-Cr-Fe, Co-Mn-Al-Cr-Fe-Si, can also be used. On the other hand, when whitening a partition wall for the purpose of effectively inducing light emission of a fluorescent substance to the whole panel, titania etc. can also be used as a fire-resistant white pigment.

As the photosensitive monomer, many compounds having an active carbon-carbon unsaturated double bond are used. As a functional group, the monofunctional and polyfunctional compound which has 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, ditrimethylol propane tetraacrylate, cyclohexyl methacrylate, ethylene glycol dimetha Acrylate, trimethylolpropane trimethacrylate, glycidyl methacrylate, and the like.

When using the paste of this invention as a photosensitive paste, it is preferable to use photosensitive polymer and / or photosensitive oligomer as binder resin. The oligomers or polymers are obtained by polymerization or copolymerization of components selected from compounds having carbon-carbon unsaturated double bonds.

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

As for the acid value of the polymer or oligomer which has acidic groups, such as a carboxyl group, in the side chain obtained in this way, the range of 50-180 and 70-140 is preferable. It is preferable from a photosensitive characteristic to add a photoinitiator in 0.005 to 5 weight% with respect to the photosensitive paste.

After the pastes of the present invention are combined so as to have a predetermined composition, they are predispersed by a mixer such as a planetary mixer, and then dispersed and kneaded in a disperser equipped with a roller in the above-mentioned cylindrical container. It is produced homogeneously by.                     

In the inorganic powder-containing paste thus obtained, the amount of foreign matter in the paste is 15 mg or less, so that the amount of foreign matter is particularly small compared with the conventional method.

The viscosity of the inorganic powder-containing paste to be dispersed is preferably within the range of 10,000 to 80,000 mPa · s from the viewpoint of dispersibility and applicability, and more preferably 15,000 to 65,000 mPa · s.

Next, the example which applies each paste manufactured by the manufacturing method of the paste of this invention to the member for display panels is demonstrated.

On the substrate, a stripe-type electrode is formed by photolithography using photosensitive silver paste as an address electrode, and a dielectric paste is applied to the substrate by screen printing, followed by baking at 500 to 600 캜 to form a dielectric layer. do.

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

The phosphor paste is formed on the partition walls thus formed. Although the formation method of a fluorescent substance is not specifically limited, For example, the screen printing method, the method of discharging fluorescent substance paste from a mold | metal, the photosensitive paste method, etc. are mentioned. Among them, the method of discharging the phosphor paste from the mold and the screen printing method are preferable because a low-cost PDP can be obtained. After apply | coating fluorescent substance paste and drying, it bakes for 30 minutes at 500 degreeC, for example, and forms a fluorescent substance layer in the side and bottom part of a partition.                     

<Examples>

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

(Paste composition)

(1) bulkhead paste

52% of glass powder with an average particle diameter of 2 µm obtained by pulverizing a glass composed mainly of lead oxide, boron oxide, zinc oxide, silicon oxide, and barium oxide, and 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) prop Cypionate] The photosensitive paste which consists of 0.05%, organic dye (basic blue 7), 0.01%, and organic solvent (propylene glycol monomethyl ether acetate) 22%.

(2) red phosphor paste

(Y, Gd, Eu) 35% of the average particle diameter of 3 ㎛ BO ₃ phosphor powder, ethyl cellulose 7% and 58% organic solvent (terpineol).

(3) green phosphor paste

(Zn, Mn) ₂ SiO ₂ 33.5% of the phosphor powder having an average particle diameter of 2.5 µm, 6.5% of ethyl cellulose, and 60% of an organic solvent (terpineol).

(4) blue phosphor paste 1                     

(Ba, Eu) MgAl ₁₀ O ₁₇ A phosphor particle having a mean particle size of 2 μm, 33.5%, ethyl cellulose 6.5%, and an organic solvent (terpineol) 60%.

(5) blue phosphor paste 2

(Ba, Eu) phosphor powder of 25.5% MgAl ₁₀ O ₁₇ average particle diameter of 2 ㎛, ethylcellulose 6.5%, an organic solvent (terpineol) by 68%.

(6) dielectric paste

80% of lead borosilicate glass with an average particle diameter of 5 micrometers of softening point 410 degreeC, 2% of ethyl cellulose, and 18% of an organic solvent (terpineol).

(7) electrode paste

3% glass powder with an average particle diameter of 0.8 µm and a methyl methacrylate / methacrylic acid copolymer (weight composition ratio 60/40, obtained by pulverizing a glass composed of bismuth oxide, silicon oxide, boron oxide, zirconium oxide, zinc oxide, and aluminum oxide) A photosensitive paste comprising 6% by weight average molecular weight 32000), 3% dipentaerythritol hexaacrylate, 1% benzophenone, 74% Ag powder having an average particle diameter of 1.2 µm, and 13% organic solvent (propylene glycol monomethyl ether acetate).

(8) Dielectric Paste for Front Panel

PbO.B ₂ O ₃ .SiO ₂ glass 75%, softening point 475 ° C, average particle diameter of 3.8 μm, ethyl cellulose 3%, organic solvent (propylene glycol n-propyl ether / tripropylene glycol n-butyl ether = 80/20) 22 %.

(9) black paste

Cu-Fe-Mn black pigment having an average particle diameter of 0.25 µm 28%, bismuth oxide, silicon oxide, zirconium oxide, zinc oxide, aluminum oxide 35% glass powder having an average particle diameter of 1.0 µm pulverized, methyl methacrylate / Photosensitive black paste consisting of 12% methacrylic acid copolymer (weight composition 60/40, weight average molecular weight 32000), dipentaerythritol hexaacrylate 5%, benzophenone 1%, organic solvent (dipropylene glycol methyl ether) 19% .

(Evaluation method of paste)

(1) viscosity

It measured on the conditions of rotation speed 3rpm and measurement temperature of 25 degreeC using the field type viscometer (the Brookfield company make, model DV-1).

(2) dispersibility

The distribution density of the particles was observed using a grind gauge (0-50 μm manufactured by Eriksen) to read the scale of the portion where the dense particles appeared. However, when the boundary line of the dense particles appeared in the middle of the scale and the scale, or when the values of the two grooves were different, the scale with the larger value was read, and the median value of the three measured values was defined as the dispersion degree of the paste.

(3) foreign matter

After dispersing 20 kg of paste after filtering with a disc filter (filtration pressure: 0.2 MPa, filter: 500 mesh) of 293 mmφ, the filter was placed in a clean container and immersed in clean acetone and washed with an ultrasonic cleaner for 30 minutes. After washing, the washing solution was further filtered through a 25 mm phi disk filter (filtration pressure: 0.05 MPa, filter: nylon net [11 μm in diameter]) to measure the amount of foreign matter remaining on the filter with precise balance.

<Examples 1 to 5>

Each paste was weighed a predetermined amount, and then preliminarily dispersed in a planetary mixer (manufactured by Inoue Seisakusho Co., Ltd.). The conditions at this time were performed for 60 minutes at 30 rpm. After completion of the preliminary dispersion, the upper vessel was set in the lower vessel of the mixer, and connected to a disperser equipped with a roller in a cylindrical vessel with a tube of 18 mmφ made of Teflon (registered trademark). 0.2 MPa of pneumatic pressure was applied to the container of the mixer, and the paste in the mixer container was extruded into the cylindrical container of the disperser. The operating conditions of the disperser were 300 rpm. Subsequently, the paste whose dispersion was complete was filtered. Filtration was performed with a disk filter (filtration pressure: 0.2 MPa, filter: 500 mesh) of 293 mmφ.

The throughput of each paste was 20 kg, and the results of measuring the time required for the 20 kg dispersion treatment, the degree of dispersion after the dispersion treatment, the viscosity, and the amount of foreign matter on the disk filter are shown in Tables 1 and 2 below.

Next, the back plate of the AC (AC) type plasma display panel was manufactured using the glass substrate (Asahi Glass Co., Ltd. product / "PD-200") of the size 340x260x2.8 mm.

On the substrate, a stripe-shaped electrode having a pitch of 140 µm, a line width of 60 µm and a thickness of 4 µm after baking was formed by photolithography using a photosensitive electrode paste as an address electrode. After apply | coating a dielectric paste to this board | substrate by the screen printing method, it baked at 550 degreeC and formed the dielectric layer of thickness 10micrometer.

Furthermore, after the pattern was formed on the dielectric layer by using a barrier paste, it was baked for 15 minutes at 570 ° C. to form a stripe-shaped barrier rib pattern having a pitch of 140 μm, a line width of 20 μm, and a height of 100 μm.

The phosphor paste was applied to the partition walls thus formed by using a method of ejecting the phosphor paste from the detention, and a phosphor layer was formed on the side and bottom of the partition walls.

Next, the front plate was manufactured by the following process. First, ITO was formed on the same glass substrate as the back plate by sputtering, and then resist coated, and a transparent electrode having a thickness of 0.1 m and a line width of 200 m was formed by exposure, development, and etching. Moreover, after baking by the photolithographic method using the photosensitive electrode paste which consists of black silver powder, the bus electrode of thickness 10micrometer was formed. Electrodes were produced having a pitch of 140 µm and a line width of 60 µm.

Furthermore, 20 micrometers of transparent dielectric pastes were apply | coated on the front plate in which the electrode was formed, and it baked and hold | maintained at 430 degreeC for 20 minutes. Next, an electron beam evaporator was used to uniformly cover the formed transparent electrode, black electrode, and dielectric layer, and a Mg0 film having a thickness of 0.5 µm was formed to complete the front plate.

After the obtained front glass substrate was bonded and sealed with the said back glass substrate, the gas for discharge was sealed, the drive circuit was bonded together, and the plasma display (PDP) was manufactured. Voltage was applied to this panel and the display state was observed. The observation results are shown in Tables 1 and 2 below.

<Example 6>

Each paste was weighed a predetermined amount, and then preliminarily dispersed in a planetary mixer (manufactured by Inoue Seisakusho Co., Ltd.). The conditions at this time were performed for 60 minutes at 30 rpm. After completion of the preliminary dispersing, the lower container of the mixer was set, and the paste was supplied to the disperser with a discharge pressure of 0.05 MPa of the pump through a double diaphragm pump (YD type manufactured by Seisakusho Co., Ltd.). To 5 and performed the same.

<Example 7>

After adjusting the inorganic powder-containing paste in the same manner as in Examples 1 to 5, a back plate and a front plate were prepared to complete the PDP.

<Comparative Examples 1 to 3>

Each paste was weighed a predetermined amount, and then preliminarily dispersed in a planetary mixer (manufactured by Inoue Seisakusho Co., Ltd.). The conditions at this time were performed for 60 minutes at 30 rpm. After completion | finish of preliminary dispersion, it divided into two-liter polyethylene containers little by little, and disperse | distributed with the triaxial roller (Inoue Seisakusho). Treatment conditions made the rotation speed of a roller 40 rpm. In Comparative Example 1, the number of passes of the triaxial roller was once, in Comparative Example 2, the number of passes was twice, and in Comparative Example 3, the number of passes was three times. Subsequently, the paste whose dispersion was complete was filtered. Filtration was performed with a disk filter (filtration pressure: 0.2 MPa, filter 500 mesh) of 293 mmφ.

The throughput of each paste was 20 kg, and the results of measuring the time required for the 20 kg dispersion treatment, the degree of dispersion after the dispersion treatment, the viscosity, and the amount of foreign matter on the disk filter are shown in Tables 1 and 2 below.

Observation of the display state of the panel was performed in the same manner as in Examples 1 to 5. The results are shown in Tables 1 and 2 below.                     

Pastes obtained in Examples 1 to 3 had a small amount of foreign matter, and a paste having good dispersibility was obtained in a short time. Moreover, the display characteristic of the panel obtained using such a paste was favorable. In Examples 4 to 5, the dispersibility was slightly decreased, but the foreign matter amount was small, and the panel display characteristics were good.

The paste obtained in Example 6 had a small amount of foreign matter, and a paste having excellent dispersibility was obtained in a short time. Moreover, the display characteristic of the panel obtained using such a paste was favorable.

In Example 7, as a result of using a paste having a small amount of phosphor powder in the blue phosphor paste, the dispersion treatment time was faster, but display unevenness occurred because the blue phosphor was thinly formed.

In Comparative Examples 1 to 3, a large amount of foreign matter was found in each paste. Dispersibility became good by increasing the number of passes, but the foreign matter amount and the paste viscosity increased. In order to improve dispersibility, the number of passes required three times, and a long processing time was required. In addition, in panel display characteristics, many panel uneven parts which were the cause of a foreign material existed, and were bad.

By processing with a disperser equipped with a roller in the cylindrical container, a paste having a small amount of foreign matter and excellent dispersibility can be obtained in a short processing time. In addition, by using the present paste, a paste capable of producing a high quality and low cost display panel member can be provided.

Claims (14)

The rotor which can rotate an inorganic powder containing paste in a cylindrical container is provided, and has many groove | channels parallel to the rotating shaft in the outer peripheral part of a rotor, and a clearance gap between at least the inner wall of a groove | channel by the centrifugal force by the rotation of a rotor in each groove | channel. A method for producing an inorganic powder-containing paste, wherein the dispersion is formed using a disperser provided with rollers that rotate in contact with the inner wall of the cylindrical container and revolve in the cylindrical container. The method for producing an inorganic powder-containing paste according to claim 1, wherein the disperser is a disperser having a paste supply port at one end of the cylindrical container and a paste discharge port at the other end. The method for producing an inorganic powder-containing paste according to claim 2, wherein the inorganic powder-containing paste is supplied to the paste supply port using a metering pump. delete The method for producing an inorganic powder-containing paste according to claim 1, wherein the diameter of the roller is in the range of 5 to 50 mm and the length is in the range of 10 to 100 mm. The method for producing an inorganic powder-containing paste according to claim 1, wherein the inner wall and the roller of the cylindrical container of the disperser are made of a ceramic material. The method for producing an inorganic powder-containing paste according to claim 1, wherein the viscosity of the inorganic powder-containing paste is in the range of 10,000 to 80,000 mPa · s. The method for producing an inorganic powder-containing paste according to claim 1, wherein the content of the inorganic powder in the inorganic powder-containing paste is in the range of 30 to 95% by weight. The method for producing an inorganic powder-containing paste according to claim 1, wherein the inorganic powder is one or two or more selected from glass, refractory fillers, phosphors, metals and metal oxides. The method for producing an inorganic powder-containing paste according to claim 1, wherein the inorganic powder-containing paste contains a compound having an unsaturated double bond. delete delete delete delete

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