KR20060118406A - Precursor paste and method of producing the same - Google Patents

Abstract

To provide a fine structure precursor paste that allows it to produce PDP ribs or other fine structures with high aspect ratio and high accuracy without causing pattern deformation or other defects. The photosensitive paste comprises a photosensitive material, fine ceramic particles dispersed as primary particles in the paste, and a surfactant comprising a phosphorus based compound and a sulfonate-based compound.

Description

Precursor paste and manufacturing method thereof {PRECURSOR PASTE AND METHOD OF PRODUCING THE SAME}

The present invention relates to photosensitive pastes, and more particularly to precursor pastes that can be advantageously used in the formation of microstructures. The present invention also relates to a method for producing a microstructure using the paste, and a microstructure produced accordingly. A typical example of the microstructure is a lip formed on a back plate for a plasma display panel.

Thin and lightweight flat panel displays have attracted much attention as next generation display devices. As an example of a large flat-panel flat panel display, a plasma display panel (PDP) is used as a wall-mounted television receiver for business and recently for home use.

The PDP has a configuration as schematically shown in FIG. In the PDP 50, only one discharge cell 56 is shown for the sake of simplicity, but the discharge cell 56 is a front glass substrate 61, a back glass substrate 51 and a rib of fine structure (barrier lip, partition wall or (Also referred to as a barrier) (54). The front glass substrate 61 has a transparent display electrode 63 including a scan electrode and a sustain electrode, a transparent dielectric layer 62 and a transparent protective layer 64 formed thereon. The back glass substrate 51 has an address electrode 53 and a dielectric layer 52 formed thereon. The display electrode 63 and the address electrode 53 including the scan electrode and the sustain electrode are orthogonal to each other and are arranged at equal intervals. Each discharge cell 56 has a phosphor layer 55 formed on its inner wall and is filled with a rare gas (for example, Ne-Xe gas), so that spontaneous light emission occurs by plasma discharge between the electrodes.

In the PDP 50 described above, the lip 54 is generally made of a ceramic microstructure, to which the microstructure of the present invention can be applied. 2 schematically shows a lip 54 of the present invention as described in detail below, wherein the lip 54 is provided on the back glass substrate 51 together with the address electrode 53 to provide a back plate of the PDP. Form.

Since the shape and dimensional precision of the lip have a significant impact on the performance of the PDP, many methods for manufacturing the lip have been proposed. One method involves molding the precursor ceramic paste into a desired shape and then sintering the paste to produce densified ceramic grains. Various improvements have been made to the mold and the method used for its manufacture. For example, a metal or glass is used as a mold material, and the curable coating liquid is disposed between the surface of the glass substrate and the mold to form ribs, and then the mold is removed after curing the coating liquid, and the substrate to which the cured coating liquid is transferred is transferred. A method of forming a lip that calcinates is proposed (see Japanese Patent Laid-Open No. 9-12336). The coating liquid is a paste containing a low melting glass powder as a main component. However, this lip forming method requires that the mold be manufactured with high working precision, the lip tends to contain air bubbles, the lip can easily peel off from the glass substrate, and the mold and the glass substrate are in intimate contact with each other under reduced pressure. Since it is necessary to maintain the pressure-reducing device, it is required to install a decompression device, thus adding various manufacturing costs and requiring a skilled worker.

In addition to improvements to the mold and methods used in its manufacture, various improvements have been made to the lip forming paste. For example, in order to enable high aspect ratio and high precision pattern formation, the photosensitive paste containing phosphorus containing compound, the photosensitive organic component, and inorganic fine particles as an essential component which focused on suppressing gelation is proposed ( See Japanese Patent Laid-Open No. 9-218509.

Summary of the Invention

The present inventors have found that when a lip is formed using a photosensitive paste having a viscosity of 26,000 and a flexible mold, various defects occur due to blowing of bubbles. The occurrence of defects due to the blowing of bubbles was particularly noticeable in the lattice pattern.

The inventors have found that when a surfactant comprising a phosphorus compound and a sulfonate compound is mixed with a photosensitive paste, the viscosity is reduced to 20,000 cps or less by improving the dispersibility of the fine particles in the paste while maintaining a high content of ceramic fine particles. Found.

Therefore, in one aspect, the present invention,

Photosensitive materials;

Ceramic fine particles dispersed as primary particles in the photosensitive material; And

Surfactant comprising a phosphorus compound having at least one phosphorus atom together with at least one -OH group, and a sulfonate compound having a sulfonate group

It relates to a precursor paste comprising a. The precursor paste preferably has a viscosity of 1,500 to 20,000 cps at 22 ° C.

In another aspect, the present invention relates to a microstructure comprising a substrate and a projection pattern having a predetermined shape and dimension formed on the surface of a substrate formed by photocuring the precursor paste of the present invention.

In another aspect, the present invention,

Manufacturing a flexible mold having a groove pattern having a shape and a dimension corresponding to the protrusion pattern to be formed on the substrate surface;

Filling the grooves of the mold with the paste, for example by placing the paste in the space between the substrate and the groove pattern of the mold;

Laminating a mold on a substrate;

Irradiating light having a predetermined wavelength to the paste to perform photocuring to form a microstructure including a substrate and a protrusion pattern integrally bonded thereto; And

Removing the mold from the microstructure

It relates to a method for producing a microstructure comprising a substrate and a projection pattern having a predetermined shape and dimensions formed on the surface of the substrate.

1 is a cross-sectional view schematically showing an example of a prior art PDP to which the present invention may be applied.

2 is a perspective view showing a back plate of a PDP having a lip of the present invention, which is an embodiment of the microstructure of the present invention.

3 is a perspective view showing one embodiment of a flexible mold used in the present invention.

4 is a cross-sectional view taken along line IV-IV of the flexible mold shown in FIG. 3.

5A to 5C are cross-sectional views sequentially showing one method of manufacturing a back plate of a PDP having a lip of the present invention.

The present invention relates to a (eg photosensitive) ceramic paste suitable for use in producing microstructures such as lip of PDP by shaping the paste based on photocuring.

The photosensitive ceramic paste contains the following three components.

(1) photosensitive material;

(2) ceramic fine particles dispersed as primary particles in a paste; And

(3) A surfactant comprising a phosphorus compound having at least one phosphorus atom together with at least one -OH group in the molecule, and a sulfonate compound having a sulfonate group in the molecule.

The photosensitive ceramic paste may optionally contain other additional ingredients.

In the photosensitive ceramic paste of the present invention, the photosensitive material as the first component may be various photosensitive materials generally used for general purpose photosensitive pastes, but is preferably photosensitive containing a monomer or oligomer having a (meth) acryl group in a molecule. Material.

Examples of methacryl group-containing monomers or oligomers suitable for the practice of the present invention include triethylene glycol dimethacrylate, diethylene glycol dimethacrylate, ethylene glycol dimethacrylate, 1,6-hexanediol dimethacrylate. , Glycerin dimethacrylate, 2-hydroxy-3-acryloyloxypropyl methacrylate, neopentyl glycol dimethacrylate, 1,10-decanediol dimethacrylate, bisphenol A diglycidyl ether meta Crylic acid adducts and EO adduct dimethacrylates of bisphenol A include, but are not limited to these. These monomers or oligomers may be used alone or in combination of two or more thereof.

The second component, i.e., the ceramic fine particles, contains various ceramic particulates commonly used in the photosensitive paste. Ceramic materials that can be advantageously used in the form of particulates in embodiments of the present invention include, but are not limited to, glass, alumina, titania, zirconia, and silica. The fine particles of these ceramic materials can be used individually or in mixtures of two or more thereof. In addition, the fine particles of one ceramic material may be coated by one or more thin film coatings of another kind of ceramic material or, if necessary, by a polymer coating instead of a ceramic material.

The ceramic fine particles may have various particle sizes, but when considered to be used for the formation of a lip or the like, it preferably has an average particle size of about 0.1 to 10 μm, more preferably about 0.5 to 5.0 μm.

In addition, the phosphorus compound used as the third component (surfactant) in the photosensitive ceramic paste together with the photosensitive resin and the ceramic fine particles has one or more phosphorus atoms together with one or more -OH groups in the molecule (that is, one or more phosphorus-based compounds). Although it will not restrict | limit especially if it is a phosphorus compound which has an acidic radical, Preferably, it is a phosphorus compound represented by following formula (I), II, III, or IV.

In the formula,

R ¹ to R ⁷ represent the same or different hydrocarbon group having 1 to 60 carbon atoms, which may optionally contain 1 to 30 heteroatoms such as oxygen, nitrogen, sulfur, etc.,

X represents an oxygen atom or a sulfur atom,

m represents the integer of 1-4.

Typical examples of phosphorus compounds include dibutyl phosphite, butyl phosphite, dimethyl phosphite, methyl phosphite, propyl phosphite, dipropyl phosphite, diphenyl phosphite, phenyl phosphite, isopropyl phosphite, diisopropyl Phosphorous acid monoalkyl (C1-10) esters and phosphorous acid dialkyl (C1-10) esters such as phosphite and n-butyl-2-ethylhexyl phosphite; Monoalkyl phosphates (C1-10) such as dibutyl phosphate, butyl phosphate, methyl phosphate, propyl phosphate, dipropyl phosphate, diphenyl phosphate, phenyl phosphate, isopropyl phosphate, diisopropyl phosphate and butyl-2-ethylhexyl phosphate Ester and phosphoric acid dialkyl (C1-10) esters; And thiophosphate compounds in which the oxygen of the phosphate ester is substituted with sulfur, but is not limited thereto. Moreover, the compound which has unsaturated groups, such as an acryl group, a methacryl group, or a vinyl group, can be used for the alkyl residue of a phosphorous acid alkyl ester. It is also possible to use compounds having phosphate or phosphinate groups. More preferable phosphorus compounds include phosphorus compounds having two or more phosphate or phosphinate groups, for example, alkyldiphosphonic acids such as hydroxyethylenediphosphonic acid.

The sulfonate compound used as a surfactant in combination with a phosphorus compound is not particularly limited as long as it is a sulfonate compound having a sulfonate group in a molecule, and examples thereof include sodium alkylbenzenesulfonate, calcium alkylbenzenesulfonate, and sodium alkylnaphthalene. Sulfonates, naphthalenesulfonic acid-formalin condensates, sodium sulfosuccinic dialkyl esters, sodium alkyldiphenyl ether disulfonates and the like.

In the photosensitive ceramic paste of this invention, it is essential to use combining 2 types of said compound as surfactant. When using these compounds in combination, the mixing ratio (weight ratio) of the phosphorus compound to the sulfonate compound is usually in the range of about 99: 1 to 1:99, and preferably in the range of about 90:10 to 10:90. When the mixing ratio is out of the above range, the ceramic fine particles cannot be dispersed to the level of the primary particles, and the viscosity cannot be reduced to the desired level.

The photosensitive ceramic paste of the present invention has a viscosity of 20,000 cps or less, preferably 2,000 to 10,000 cps, as measured at 22 ° C. When the viscosity of the paste is reduced by reducing the content of the glass fine particles in the paste, an unavoidable problem occurs such as an increase in shrinkage during firing, an increase in defects and an increase in deformation of the lip. According to the invention, surfactants having phosphate groups are used synergistically in combination with surfactants having sulfonate groups. By doing in this way, it becomes unexpectedly possible to disperse glass or ceramic microparticles | fine-particles to the level of a primary particle in the photosensitive paste. As a result, for example, in the case of a photosensitive paste containing 80% by weight of glass fine particles, the viscosity can be reduced to 10,000 cps or less.

As described in the accompanying examples, the viscosity of the photosensitive paste containing 80% by weight of the glass fine particles could be reduced only to a high value of 26,000 cps when only a phosphorus-based compound having a phosphate group was added as the surfactant. In addition, the viscosity of the photosensitive paste could be reduced only to a high value of 35,000 cps when only sulfonate-based compounds having sulfonate groups were added as surfactants. However, when using a phosphorus compound having a phosphate group in combination with a sulfonate compound having a sulfonate group as illustrated, the viscosity of the photosensitive paste could be reduced to a value as low as 6,000 cps. In addition, the maximum particle size of the paste of the present invention was about 2 to 3 µm, and glass fine particles were dispersed as primary particles (average particle size of about 2 to 3 µm), which greatly contributed to the effect of the present invention.

In addition, the pastes described herein have been shown to have improved shelf life. For example, when the paste of the present invention was left at 22 ° C. for 2 months, there was no degradation exhibited by gelation.

The content of ceramic fine particles in the photosensitive ceramic paste of the present invention is usually in the range of about 60 to 90% by weight, preferably in the range of about 70 to 85% by weight. If the ceramic fine particle content in the paste is outside the above range, it may adversely affect the production and properties of the microstructure. Poor effects such as poor application of the paste, damage or defect of microstructures such as lip, and difficulty in releasing from the mold may occur.

The photosensitive ceramic paste of this invention contains the additive normally used for the general purpose photosensitive paste other than the above-mentioned component. Suitable additives include binders, photopolymerization initiators, diluents, ultraviolet absorbers, sensitizers, sensitizers, polymerization inhibitors, plasticizers, thickeners and organic solvents.

The photosensitive ceramic paste of the present invention may have various compositions as long as it satisfies the above-described structural features, preferably

5 to 15 parts by weight of the photosensitive resin,

60 to 90 parts by weight of ceramic fine particles,

0.1 to 1.0 parts by weight of a surfactant prepared from a phosphorus compound,

0.1 to 1.0 parts by weight of a surfactant prepared from a sulfonate compound,

5 to 15 parts by weight of a diluent, and

0.02 to 0.25 parts by weight of photopolymerization initiator

It has a composition comprising a.

Ceramic paste having such a composition may contain any additive in a commonly used amount.

The photosensitive ceramic paste of the present invention is preferably cured by photocuring by light irradiation through a flexible mold having a groove pattern having a predetermined shape and dimension formed on the substrate surface, and thus the microstructure providing precursor paste. Useful as A typical example of a microstructure is a lip formed on the back plate of a PDP. The groove pattern of the flexible mold in the manufacture of the lip on the back plate of the PDP may be a straight pattern consisting of a plurality of grooves arranged at equal intervals substantially parallel to each other, but preferably substantially parallel to each other It is a grid pattern composed of a plurality of grooves arranged at equal intervals to cross each other. That is, the lip of the back plate of the PDP may be formed in a straight pattern or a lattice pattern, but a lattice pattern is preferable.

The present invention provides a microstructure having a projection pattern having a predetermined shape and dimension formed on the substrate surface. The microstructure of the present invention is preferably a lip of the back plate of the PDP. In the back plate of the PDP, the protruding lip pattern is a straight line pattern composed of a plurality of ribs arranged at equal intervals substantially parallel to each other, or a plurality of ribs arranged at equal intervals so as to cross each other substantially parallel to each other. It may be a lattice pattern composed of ribs, but is preferably a rib of the lattice pattern.

The present invention also provides a method for producing a microstructure having a projection pattern having a predetermined shape and dimension formed on a substrate surface. The method of the present invention,

Manufacturing a flexible mold having a groove pattern having a shape and a dimension corresponding to the protrusion pattern formed on the surface;

Disposing the photosensitive ceramic paste (microstructure precursor paste) of the present invention in a space between the substrate and the groove pattern of the mold to fill the grooves of the mold with the ceramic paste, and stacking the mold on the substrate;

Irradiating light having a predetermined wavelength to the ceramic paste to perform photocuring to form a microstructure including a substrate and a protrusion pattern integrally bonded thereto; And

Removing the mold from the microstructure

It includes.

As mentioned above, the microstructure is preferably a lip of the back plate of the PDP. Thus, the method further comprises the step of forming a set of address electrodes on the surface of the substrate, substantially parallel to each other, at equal intervals independently of each other.

The mold used in the practice of the present invention is preferably flexible, comprising a support and a shaping layer provided on the support and having a groove pattern having a predetermined shape and dimension corresponding to the projection pattern formed on the surface. Mold. The flexible mold is described in detail below.

With reference to the accompanying drawings will be described in more detail the practice of the present invention.

2 shows a lip 54 of a PDP, which is a typical example of the microstructure of the present invention. The lip 54 of the PDP is formed on the back glass substrate 51 to constitute the back plate of the PDP, and can be advantageously used when included in the PDP 50 as shown in FIG. Although the illustrated lip 54 is formed in a straight pattern, the lattice patterns orthogonal to each other are also included in the scope of the present invention, and when the lip is formed in the lattice pattern, the photosensitive ceramic paste of the present invention will fully achieve its excellent effect. Can be.

The spacing c (cell pitch) of the lip 54 shown in the figure may vary depending on the screen size and / or other factors, but is usually in the range of about 150 to 400 μm. In general, it is required that the lip be free of defects and have high dimensional accuracy. For dimensional precision, the lip is required to be formed at a predetermined position corresponding to the address electrode with little error (only an error of several tens of micrometers is allowed). If the position error exceeds several tens of micrometers, it will adversely affect the emission condition of visible light, and satisfactory spontaneous light emission will be impossible. As the size of the screen becomes more common, the lip pitch precision has a serious problem.

When the lip 54 is viewed as a whole, there is a slight difference depending on the size of the substrate and the shape of the lip, but the total pitch R of the lip (distance between the ribs at both ends: only five ribs are shown in the drawing, but in reality, About 3,000 ribs are present), requiring tens of ppm precision. In the practice of the present invention, a flexible mold comprising a support and a forming layer supported by the support and having a groove pattern is advantageously used, but the precision of several tens of ppm is also expressed in the total pitch R of the mold (the distance between the grooves at both ends). Is required. According to the present invention, the problem of these dimensional accuracy can also be solved.

Although any flexible mold can be advantageously used in the practice of the present invention, the mold preferably includes a support comprising a plastic film, and a groove pattern (groove) formed by molding the photocurable resin on one side of the support. It includes a shaping layer having.

Suitable supports for the practice of the invention are films made of plastics materials. Examples of suitable plastic materials for use as the support include, but are not limited to, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), oriented polypropylene, polycarbonate and triacetate. PET films of these plastic materials are useful as supports, for example polyester films such as Tetoron (trade name) films can be advantageously used as a support. These plastic films can be used as a single | mono layer film or a multilayer film combining these 2 or more types.

In addition, the plastic film may have various thicknesses depending on the configuration of the mold and the PDP, and the thickness is usually in the range of 0.01 to 1.0 mm, preferably in the range of 0.1 to 0.4 mm. If the thickness of the support is outside the above range, handling becomes difficult. The thicker the support, the more advantageous it is.

The flexible metal mold | die has the shaping | molding layer provided on it in addition to the said support body. As will be described in detail below, the shaping layer has a groove pattern having a predetermined shape and dimension formed on the surface thereof corresponding to a projection pattern such as a lip or other microstructure of a PDP back plate manufactured using a mold. This can also be called a shape forming layer. Although a shaping | molding layer is comprised normally from a single layer, it may be formed in a multilayered structure from 2 or more types of materials which have a different characteristic as needed. When it is contemplated to use a photocurable molding material, both the support and the molding layer are preferably transparent.

Hereinafter, the configuration of the flexible mold will be described with reference to FIGS. 3 and 4. In addition, from the following description, the configuration of the ribs formed into a lattice pattern by photocuring using a flexible mold can also be easily understood.

3 is a schematic perspective view of a portion of a preferred embodiment of a flexible mold, and FIG. 4 is a cross-sectional view cut along the line IV-IV of FIG. 3. As can be seen from these figures, the flexible mold 10 has a back glass substrate 51 having ribs in a straight pattern including a plurality of ribs 54 arranged in parallel with each other as shown in FIG. 2. It is not designed to make). This is for producing a back glass substrate having the ribs of the lattice pattern, which, although not shown, comprises a plurality of ribs arranged substantially parallel to and intersecting with each other. The photosensitive ceramic paste of the present invention is particularly useful for producing back glass substrates having ribs of lattice pattern.

The flexible mold 10 has a groove pattern having a predetermined shape and dimensions formed on its surface as shown. The groove pattern is composed of a plurality of grooves 4 arranged at equal intervals while crossing substantially parallel to each other. As such, the flexible mold 10 may also be used for the production of other microstructures, but such a configuration having grooves formed in a lattice pattern on the surface is particularly useful for forming PDP ribs having projections of the lattice pattern. The flexible mold 10 may have additional layers as needed, or may process its component layers, but basically the support 1 and the grooves 4 formed thereon as shown in FIG. 3. It consists of the shaping | molding layer 11 which has a.

The shaping layer 11 is preferably made of a curable material. The curable material is a thermosetting material or a photocurable material. In particular, photocurable materials are useful because they can be cured in a relatively short time without the need for an extensive heating furnace to form the forming layer. The photocurable material is preferably a photocurable monomer or oligomer, more preferably an acrylic monomer or oligomer. The curable material may contain any additives. Suitable additives include polymerization initiators (eg photoinitiators) and antistatic agents.

Examples of suitable acrylic monomers for forming the shaping layer include, but are not limited to, urethane acrylate, polyether acrylate, acrylamide, acrylonitrile, acrylic acid and acrylic acid ester. Examples of acrylic oligomers suitable for forming the molding layer include, but are not limited to, urethane acrylate oligomers and epoxy acrylate oligomers. In particular, the urethane acrylate and its oligomers can provide a flexible and tough cured product after curing, and contribute to the improvement of the productivity of the mold because the curing speed is very high among the acrylates. Moreover, when these acrylic monomers or oligomers are used, a shaping | molding layer becomes optically transparent. Thus, a flexible mold including such a molding layer enables the use of a photocurable molding material in the production of microstructures such as PDP ribs. These acrylic monomers or oligomers may be used alone or in combination of two or more thereof.

As mentioned above, the support 1 carrying the shaping layer 11 is preferably a plastic film whose thickness is usually in the range of about 0.05 to 1.0 mm. In addition, the support is preferably optically transparent. When the support is optically transparent, the molding layer can be formed using a photocurable molding material because light irradiated for curing can be transmitted through the support. Typical examples of transparent supports are as described above.

When the flexible mold as described above and the fine ceramic structure of the present invention are combined in a molding operation, various microstructures may be manufactured according to the characteristics of the mold and the paste. For example, using the flexible mold shown in Figs. 3 and 4, it is possible to produce a lip of a PDP having a lattice pattern having high aspect ratio and high precision without causing any defect in the lip without requiring skill. have. In addition, the use of flexible molds makes it easy to manufacture large screen PDPs having such a lip structure by simply using laminated rolls instead of vacuum equipment and / or complicated processes.

The present invention also provides a microstructure and a method of manufacturing the same. The fine structure can be formed in various structures, but a typical example thereof is a lip portion of a substrate (back plate) of a PDP, in which the lip is formed on a glass plate. Hereinafter, with reference to FIG. 5, the method of manufacturing the PDP board | substrate which has the rib of a grid pattern using the flexible metal mold | die shown in FIG. 3 and FIG. 4 is demonstrated. For example, the manufacturing apparatus shown in FIGS. 1-3 of Unexamined-Japanese-Patent No. 2001-191345 can be used advantageously for implementation of this invention.

Although not shown, glass plates having electrodes arranged at equal intervals parallel to each other are prepared in advance and set on a surface plate. Subsequently, as shown in Fig. 5A, the flexible mold 10 of the present invention having the groove pattern is disposed at a predetermined position on the glass flat plate 31, and the glass flat plate 31 and the metal mold 10 are placed. Perform the sort of. Since the metal mold | die 10 is transparent, alignment of the glass plate 31 and an electrode can be performed easily. More specifically, the alignment is performed visually or by using a sensor such as a CCD camera so that the grooves of the mold 10 and the electrodes on the glass plate 31 are parallel to each other. At this time, temperature and humidity can be adjusted as needed to match the distance between the mold 10 and the adjacent electrode on the glass plate 31. This is because the mold 10 and the glass plate 31 expand and contract to a different degree according to temperature and humidity. Therefore, after the alignment of the glass plate 31 and the metal mold | die 10 is completed, the temperature and humidity at that time are adjusted constantly. This control method is particularly effective for the production of large surface area PDP substrates.

Next, the lamination roll 23 is arrange | positioned at one edge of the metal mold | die 10. The lamination roll 23 is preferably a rubber roll. One edge of the mold 10 is preferably fixed on the glass plate 31. In this way, the alignment of the glass plate 31 (with electrodes) with the mold 10 can be maintained during subsequent operations.

Next, the other free edge of the metal mold | die 10 is lifted up by the holder (not shown), and it moves to the upper side of the lamination roll 23, and exposes the glass flat plate 31. FIG. At this time, care is taken not to apply tension to the mold 10 to prevent wrinkles in the mold 10 and to maintain alignment between the glass plate 31 and the mold 10. However, other means can be used as long as it can maintain an aligned position. In the above method, since the mold 10 has elasticity, even when the mold 10 is rolled up as shown in the drawing, the mold 10 is returned to the aligned position correctly when subsequent lamination is performed.

Subsequently, a predetermined amount of the photosensitive paste 33 required for the formation of the lip is supplied onto the glass plate 31. The photosensitive paste 33 contains the photosensitive ceramic paste of this invention mentioned above. The photosensitive ceramic paste 33 can be supplied using the paste hopper with which the nozzle was attached, for example.

When applying the method shown in the figure, the photosensitive ceramic paste 33 is not uniformly supplied to the entire surface on the glass flat plate 31. Instead, the lip precursor 33 is supplied only to the position on the glass plate 31 in the vicinity of the lamination roll 23 as shown in Fig. 5A. This is because the photosensitive ceramic paste 33 can be uniformly applied onto the glass flat plate 31 as the lamination roll 23 moves on the mold 10 in the following steps. In addition, in order to smoothly perform this operation, the photosensitive ceramic paste 33 preferably has a viscosity in the range of 2,000 to 10,000 cps. However, the supply method of the photosensitive ceramic paste is not limited to the above-mentioned method. For example, although not shown, the photosensitive ceramic paste may be applied such that the entire surface of the glass plate is coated.

Subsequently, the lamination roll 23 is moved on the mold 10 at a predetermined speed by a rotating motor (not shown) as indicated by the arrows in FIG. 5 (A). While the lamination roll 23 is moving on the mold 10, the pressure is sequentially applied on the mold 10 by the gravity of the lamination roll 23 from one edge thereof to the other edge thereof, so that the glass plate 31 and The grooves of the mold 10 are filled with the paste by applying the photosensitive ceramic paste 33 over the spaces between the molds 10. That is, the photosensitive ceramic paste 33 is replaced with air to sequentially fill the grooves. At this time, the thickness of the photosensitive ceramic paste can be adjusted within the range of several micrometers to several tens of micrometers by adjusting the viscosity of the ceramic paste or the diameter, weight, or moving speed of a lamination roll.

In addition, according to the method shown in the figure, the groove of the mold also functions as a channel of airflow. Even when air is trapped in the grooves, when pressure is applied as described above, air can be efficiently purged to the outside of the mold. As a result, even when the photosensitive ceramic paste is supplied under atmospheric pressure by the above method, bubbles can be prevented from remaining in the grooves. That is, the need for pressure reduction in the application of the photosensitive ceramic paste can be eliminated. Of course, the pressure can be reduced to make it easier to remove bubbles.

Next, the photosensitive ceramic paste is cured. When the ceramic paste 33 coated on the glass plate 31 is photocurable, as shown in FIG. 5 (B), the laminate of the glass plate 31 and the mold 10 is a light irradiation apparatus (not shown). Irradiated with ultraviolet (UL) to the ceramic paste 33 through the glass plate 31 and the mold 10. Thus, a lip made of the photosensitive ceramic paste is formed.

Finally, the glass plate 31 and the metal mold | die 10 are taken out from the light irradiation apparatus in the state which bonded the lip 34 on the glass plate 31, and the metal mold | die 10 is shown in FIG. 5 (C). ). Molds typically have good release properties. However, a release coating may optionally be applied to the mold in order to easily remove the mold 10 with little force without damaging the lip 34 adhered to the glass plate 31. Of course, no large-scale devices are required for this removal.

Example  One

Preparation of Photosensitive Glass Paste:

The following materials were prepared in the following amounts for the preparation of the glass paste.

Photocurable oligomer: 318.5 g of bisphenol A diglycidyl methacrylate acid adduct (manufactured by Kyoeisha Co., Ltd.)

Photocurable polymer: 136.5 g of triethylene glycol dimethacrylate (manufactured by Wako Pure Chemical Industries, Ltd.)

Diluent: 455.0 g of 1,3-butanediol (made by Wako Pure Chemical Industries, Ltd.)

Photocuring initiator: 6.4 g of bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (manufactured by Ciba Specialty Chemicals, trade name "Irgacure 819")

Ceramic fine particles: 4093.0 g of mixed powder of lead glass and ceramic (manufactured by Asahi Glass Co., trade name "RFW-030")

Phosphorus-based surfactant: 25.3 g of phosphate propoxyalkyl polyol (manufactured by 3M Corporation, trade name "POCA")

Sulfonate surfactant: Sodium dodecylbenzenesulfonate (manufactured by Kao Co., trade name "NeoPelex # 25") 25.3 g

All of these raw materials were placed in an attritor mill and dispersed at 30 ° C. for 1 hour using a zirconia ball having a diameter of 7 mm as a dispersion medium.

After completion of the dispersion process, the paste was taken out of the attritor and left at 22 ° C. for a day. The viscosity of the paste was then measured with a Brookfield B viscometer with the measurement conditions of shaft # 5 and rotation speed 20 rpm. The paste exhibited a viscosity of 6,000 cps.

Preparation of PDP Backplate:

In order to manufacture the back plate of the PDP, a flexible resin mold having 2593 ribs each having a height of 200 mu m, an upper width of 100 mu m, and a pitch of 360 mu m having a length of 540 mm was manufactured.

Using a coating blade, the PDP glass substrate was coated with a photosensitive ceramic paste prepared as described above to a thickness of about 100 μm. The flexible mold was then laminated onto a glass substrate coated with glass paste while bending and aligning. A lamination roll 200 mm in diameter and 100 kg in weight was moved at a speed of 40 mm / sec. The pressure applied to the mold was only generated by the weight of the lamination roll.

The mold laminated on the glass substrate was irradiated with light having a wavelength of 400 to 450 nm on both sides of the mold and the glass substrate for 30 seconds using a fluorescent lamp array manufactured by Phillips Corp .. Thus, the photosensitive glass paste was cured to form lip. The glass substrate was removed from the mold together with the lip formed thereon to obtain a glass substrate having the lip.

The total pitch (distance between the lip of both ends) on the metal mold | die used for the shaping | molding operation | work, and the obtained glass substrate was measured by 5 points, and the result as shown in following Table 1 was obtained.

As understood from the measurement results shown in Table 1 above, the lip prepared using the phosphorus-based surfactant and sulfonate-based surfactant in the paste according to the present invention exhibited substantially the same dimensions as the mold, resulting in high dimensional accuracy. Shows that the lip was formed.

Subsequently, the glass substrate having the ribs formed thereon was baked at 550 ° C. for 1 hour to remove the organic component contained in the paste by combustion to form a lip made of the glass component. As a result of observing the lip formed on the back plate with an optical microscope, no defect was detected.

Comparative example  One

Perform the method described in Example 1, but for comparison, 50.6 g of phosphorus-based surfactant (phosphate propoxylalkyl polyol) is used instead of combining phosphorus-based and sulfonate-based surfactants in the preparation of the photosensitive ceramic paste. It was. The B viscosity of the paste thus obtained was found to be 26,000 cps (shaft # 5, 20 rpm).

Then, using the photosensitive ceramic paste prepared as described above, a glass substrate having a lip formed thereon was prepared by the method described in Example 1. In this comparative example, since the glass paste had a high viscosity of 26,000 cps, higher pressure was applied when laminating the mold on the glass substrate coated with the glass paste. Specifically, a lamination roll of 200 mm in diameter and 250 kg in weight was moved at a speed of 20 mm / sec. The glass substrate was removed from the mold together with the lip formed thereon to obtain a glass substrate having the lip.

The total pitch (distance between the ribs at both ends) of the mold used for the molding operation and the obtained glass substrate was measured at five points, and the results shown in Table 2 below were obtained.

As understood from the measurement results shown in Table 2 above, the lip produced using a paste containing only a phosphorous surfactant showed a dimensional difference of up to about 70 μm from the mold. In this comparative example, a lip having high dimensional accuracy could not be easily formed.

Subsequently, the glass substrate having the ribs formed thereon was baked at 550 ° C. for 1 hour to remove the organic component contained in the paste by combustion to form a lip made of the glass component. As a result of observing the lip formed on the back plate with an optical microscope, many defects were detected.

Comparative example  2

50.6 g of sulfonate-based surfactants (sodium dodecylbenzenesulfonate, instead of using a combination of phosphorous and sulfonate-based surfactants in the preparation of the photosensitive ceramic paste, for comparison) ) Was used. The B viscosity of the paste thus obtained was 35,000 cps (shaft # 5, 20 rpm).

Then, using the photosensitive ceramic paste prepared as described above, a glass substrate having a lip formed thereon was prepared by the method described in Example 1. In this comparative example, since the glass paste had a high viscosity of 35,000 cps, higher pressure was applied when laminating the mold on the glass substrate coated with the glass paste. Specifically, a lamination roll of 200 mm in diameter and 250 kg in weight was moved at a speed of 10 mm / sec. The glass substrate was removed from the mold together with the lip formed thereon to obtain a glass substrate having the lip.

The total pitch (distance between the lips at both ends) of the mold used for the molding operation and the lip on the obtained glass substrate was measured at 5 points. Similar to Comparative Example 1, the measurements indicated that the lip had a dimensional difference of up to about 100 μm with the mold. In conclusion, in the present comparative example, no lip with high dimensional accuracy could be formed.

Subsequently, the glass substrate having the ribs formed thereon was baked at 550 ° C. for 1 hour to remove the organic component contained in the paste by combustion to form a lip made of the glass component. As a result of observing the lip formed on the back plate with an optical microscope, many defects were detected.

Claims (13)

Photosensitive materials; Ceramic particles dispersed in the photosensitive material; A first surfactant comprising a phosphorus compound having at least one phosphorus atom together with at least one —OH group; And Second surfactant containing a sulfonate compound having a sulfonate group Precursor paste comprising a. The precursor paste of claim 1 having a viscosity of 1,500 to 20,000 cps at 22 ° C. 3. The precursor paste of claim 1 wherein the ceramic particles are present in an amount ranging from 60 wt% to 90 wt%. The precursor paste of Claim 1 or 2 in which the photosensitive material contains the monomer or oligomer which has a (meth) acryl group. The precursor paste of claim 1, wherein the ceramic particles comprise one or more materials selected from the group consisting of glass, alumina, titania, zirconia, silica, and mixtures thereof. The precursor paste according to claim 1, wherein the average particle size of the ceramic particles is in the range of 0.1 to 10 μm. The precursor paste of claim 1, wherein the first surfactant is present in a ratio of 99: 1 to 1:99 relative to the second surfactant. The method according to any one of claims 1 to 3, 5 to 15 parts by weight of the photosensitive resin; 60 to 90 parts by weight of ceramic particles; 0.1 to 1.0 parts by weight of a first surfactant including a phosphorus compound; 0.1 to 1.0 parts by weight of a second surfactant including a sulfonate compound; 5 to 15 parts by weight of the diluent; And 0.02 to 0.25 parts by weight of photopolymerization initiator Precursor paste comprising a. An article comprising a substrate and a projection pattern having a predetermined shape and dimension formed on a surface of a substrate, formed by photocuring the microstructure precursor paste of claim 1. The article of claim 9, wherein the protruding pattern is a straight pattern formed by placing the plurality of ribs at substantially equal intervals substantially parallel to each other. 10. The article of claim 9, wherein the protruding pattern is a lattice pattern formed by placing the plurality of ribs at substantially equal intervals such that they are substantially parallel to each other and intersect with each other. Providing a flexible mold having a groove pattern having a shape and a dimension corresponding to the protrusion pattern to be formed; Filling the groove of the mold with the precursor paste of any one of claims 1 to 3; Laminating a mold on a substrate; Photocuring the paste; And Step to remove the mold Comprising a method of manufacturing an article. A plasma display panel lip formed from the method of claim 12.

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