JPH11256047A - Photosensitive paste - Google Patents

Abstract

(57) Abstract: Provided is a photosensitive paste which is excellent in partition wall pattern formability particularly for a plasma display and a plasma addressed liquid crystal display. A photosensitive paste containing inorganic fine particles and a photosensitive organic component as essential components has a yield value of 0.5 to 5 Pa.
And

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive paste.

[0002]

2. Description of the Related Art Plasma display panels (PDPs)
Since plasma display devices and plasma-addressed liquid crystal displays can be easily increased in size, they have permeated OA equipment and public information display devices. Further, progress in the field of high-definition television is highly expected.

With the expansion of such applications, attention has been paid to color PDPs having a large number of fine display cells.
The PDP generates a plasma discharge between electrodes facing each other in a discharge space provided between a front glass substrate and a rear glass substrate, and emits ultraviolet light generated from a gas sealed in the discharge space. The display is performed by hitting the fluorescent material inside. In this case, in order to suppress the spread of the discharge to a certain area and perform the display in the specified cell, and at the same time, to secure a uniform discharge space, the partition (barrier,
Ribs).

The size of the partition walls is about 30 to 80 μm in width and about 100 to 200 μm in height. Usually, an insulating paste made of glass is applied to the back glass substrate by a screen printing method and dried. After forming a predetermined height by repeating the process more than twice, it is formed by firing. However, in the ordinary screen printing method, particularly when the panel size is increased, it is difficult to align the discharge electrode formed on the front substrate in advance with the printing location of the insulating paste, and it is difficult to obtain positional accuracy. There is. In addition, since the insulating paste is superposed and applied 10 times or more, the waving of the side edges of the partition walls and the wall and the disturbance of the skirt occur, and the accuracy of the height cannot be obtained, so that the display quality deteriorates. There are also problems such as poor workability and low yield. In particular, when the pattern line width is 50 μm and the pitch is 150 μm or less, there is a problem that the bottom of the partition wall is easily blurred due to the thixotropy of the paste, and it is difficult to form a sharp and residue-free partition wall.

[0005] With the increase in the area and resolution of PDPs, the screen printing method makes it difficult to manufacture partition walls having a high aspect ratio and a high definition, and it is disadvantageous in terms of cost. Is coming.

As methods for improving these problems, Japanese Patent Application Laid-Open Nos. 1-2296534, 2-165538, 5-342929, and 6-29 have been proposed.
No. 5676 proposes a method of forming a partition by a photolithography technique using a photosensitive paste. However, in these methods, there are problems that a dense partition wall cannot be obtained after firing and that the sensitivity and resolution of the photosensitive paste are low because the glass content of the photosensitive insulating paste is small. Therefore, in order to obtain a partition wall having a high aspect ratio, it is necessary to repeatedly perform the steps of screen printing, exposure, and development. However, if printing, exposure, and development are repeatedly performed, there is a limit due to a problem of alignment and a problem of cost.

Japanese Patent Application Laid-Open No. 8-50811 proposes a method in which a partition is formed by one exposure using a photosensitive glass paste method. However, in this method, the pitch is 200 μm or less, and the line width of the partition is 50 μm.
When producing the following high-definition partition walls, depending on the ratio of the inorganic component and the organic component in the photosensitive paste, the line width is increased, a desired line width is not obtained, or development remains, and a so-called residual film occurs. And poor pattern formability. Further, it is difficult for the organic components to disappear during baking, so-called binder removal property is poor, peeling and coloring may be caused, shrinkage during baking may be increased, and the height during pattern formation may be increased in order to obtain partition walls having a desired height. Need to be higher,
There is a problem that the margin at the time of pattern formation is small and the yield is deteriorated.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide a photosensitive paste having good pattern formability when used for forming partition walls.

[0009]

In order to achieve the above object, the present invention provides a photosensitive paste containing inorganic fine particles and a photosensitive organic component as essential components, wherein the paste has a yield value of 0.5 to 5 Pa. The photosensitive paste is characterized in that:

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The photosensitive paste of the present invention contains a photosensitive organic component and inorganic fine particles as essential components, and has a yield value of 0.
It is necessary to be 5 to 5 Pa. Paste is ideal Ne
Although the yield value in the case of showing the wtonian flow is 0, it is difficult to reduce the yield value to 0 with an actual photosensitive paste. It has been found that by adjusting this to a range of 0.5 to 5 Pa, pattern formability is improved. In the present invention, the yield value is a value measured indirectly by measuring a shear stress (= viscosity × shear speed) with respect to a shear speed and extrapolating the shear speed to zero. The measured value of the shear stress is a rotary viscometer RVDV-II + with a digital operation function manufactured by Brookfield, USA.
Series), small amount spindle (SC4-14)
Is a value obtained by measuring 2 ml of the photosensitive paste kept at a temperature of 25 ° C. in FIG.

The photosensitive paste having a yield value of 0.5 to 5 Pa has good coatability and gives a coated film surface having excellent smoothness, and therefore, irregular reflection on the surface of irradiated light is reduced. Furthermore, since the dispersibility of the inorganic fine particles is excellent, no air bubbles are generated in the paste due to entrainment of air, the scattering of light inside the paste is reduced, and the light transmittance is improved. These effects enable excellent pattern formation.

The partition to be formed by the photosensitive paste of the present invention has a height of 60 to 170 μm, which is advantageous in terms of discharge stability and luminance. In consideration of firing shrinkage, the thickness of the photosensitive paste applied film for forming the partition pattern must be 100 to 220 μm. In order to expose a high-definition pattern to a photosensitive paste coating film of such a thickness and to form a pattern with a high aspect ratio with high resolution, the active light beam for exposure must be transmitted as much as possible to the bottom of the coating film. Is required.

For this reason, in the present invention, the photosensitive paste has a total light transmittance of 5 μm as measured on a coating film having a thickness of 50 μm.
It is preferably at least 0%. In this case, the measurement wavelength is
After applying the paste, the measurement is performed at the wavelength of the light to be exposed. The light transmittance was measured using a spectrophotometer (UV
-3101PC).

In order to increase the total light transmittance, it is important to select a material having a high light transmittance to be blended with the photosensitive paste and uniformly mix them. Regarding the inorganic fine particles, it is required that the composition inside the powder is uniform and there is no composition unevenness such as bubbles. However, even if these are satisfied, a photosensitive paste having a high total light transmittance may not be obtained, and if the total light transmittance is low, active light for exposure may not be sufficiently transmitted to the lowermost portion of the coating film. ,
A high-definition pattern cannot be formed, a residual film is formed, a meandering of a partition pattern is generated, and when a display is manufactured, luminance may be reduced or luminance unevenness may occur.

Therefore, in the present invention, the inorganic fine particles 60
It is preferable that at least% by weight be glass fine particles.

Further, in a mixture system in which glass fine particles are dispersed in a photosensitive organic component such as a photosensitive paste, the light transmittance is determined by the fact that the average refractive indexes of these components are close to each other. Become the most important to enhance.

For this reason, it is preferable to use glass fine particles having an average refractive index of 1.5 to 1.65 as the inorganic fine particles in the photosensitive paste. Thereby, the difference between the average refractive index of the glass fine particles and the average refractive index of the photosensitive organic component is reduced, light scattering in the photosensitive paste is suppressed, and a partition pattern with a high aspect ratio is formed with high precision. Can be.

Generally, the refractive index of the organic component is 1.45 to
Since the refractive index of the glass fine particles is higher, the average refractive index of the glass fine particles is controlled to 1.5 to 1.65 in order to match the refractive indices of the two. It is preferable to make the difference from the refractive index about 0.05.

Further, the glass fine particles have an average refractive index of 1.
5 to 1.65, a coefficient of thermal expansion in a temperature range of 50 to 400 ° C. is 70 to 85 × 10 ⁻⁷ / K, a glass transition point of 450 to 550 ° C. and a softening point of 50.
The temperature is preferably from 0 to 600 ° C.

As the glass component satisfying the above conditions, those having the following components and the compounding amounts are used. That is, it has a composition of, in oxide notation, lithium oxide 2 to 10% by weight silicon oxide 10 to 30% by weight boron oxide 20 to 40% by weight barium oxide 2 to 15% by weight aluminum oxide 6 to 25% by weight.

The use of glass fine particles containing 2 to 10% by weight of lithium oxide not only facilitates the control of the softening point and the coefficient of thermal expansion, but also lowers the average refractive index of the glass. It is easy to reduce the difference in refractive index between the two. In order to improve the stability of the paste, the addition amount of the alkali metal oxide
It is preferably at most 10% by weight, more preferably at most 8% by weight.

In the above composition, sodium oxide or potassium oxide may be used instead of lithium oxide, but lithium oxide is preferred in view of paste stability.
When potassium oxide is used, there is an advantage that the refractive index can be controlled even with a relatively small amount of addition. Therefore, among alkali metal oxides, addition of lithium oxide and potassium oxide is effective.

The silicon oxide is preferably blended in the range of 10 to 30% by weight, and if it is less than 10% by weight, the denseness, strength and stability of the glass layer are reduced, and the coefficient of thermal expansion is reduced from a desired value. Detachment and mismatch with the glass substrate are likely to occur. Further, by setting the content to 30% by weight or less, there is an advantage that the thermal softening point is lowered and baking on a glass substrate becomes possible.

It is preferable that boron oxide is blended in the range of 20 to 40% by weight. If it exceeds 40% by weight, the stability of the glass is reduced. Boron oxide is 800
Baking so as not to impair the electrical, mechanical and thermal properties such as electrical insulation, strength, coefficient of thermal expansion, and denseness of the insulating layer, even when melting at a temperature of about 1200 ° C. and even when silicon oxide is large. It is blended to control the temperature in the range of 550-600 ° C. If it is less than 20% by weight, the strength of the insulating layer is reduced, and the stability of the glass is reduced.

Barium oxide is preferably blended in the range of 2 to 15% by weight. If it is less than 2% by weight, it is difficult to control the glass baking temperature and the electrical insulation.
On the other hand, if the content exceeds 15% by weight, the stability and the denseness of the glass layer decrease.

It is preferable that aluminum oxide is blended in the range of 6 to 25% by weight. Aluminum oxide is added to increase the strain point of the glass. If it is less than 6% by weight, the strength of the glass layer is reduced. If it exceeds 25% by weight, the heat-resistant temperature of the glass becomes too high, so that it is difficult to bake on the glass substrate. Further, it becomes difficult to obtain a dense insulating layer at a temperature of 600 ° C. or lower.

Although not described in the above composition, calcium oxide or magnesium oxide may be added. It is preferable to mix calcium oxide in the range of 2 to 10% by weight. It is added to facilitate melting of the glass and control the coefficient of thermal expansion. If it is less than 2% by weight, the strain point will be too low. Further, it is preferable that magnesium oxide is blended in a range of 1 to 10% by weight. Magnesium oxide is added to facilitate melting of the glass and control the coefficient of thermal expansion. If it exceeds 10% by weight, the glass tends to be devitrified, which is not good.

It is preferable that the glass fine particles do not contain metal oxides such as sodium oxide and yttrium oxide which deteriorate the plasma discharge characteristics. Even when it is contained, it is at most 5% by weight.

Further, titanium oxide, zirconium oxide and the like may be contained in the glass fine particles.
Preferably, it is less than about 10% by weight. Zirconium oxide is effective in controlling the softening point, glass transition point, and electrical insulation.

As a method for producing glass fine particles, for example, compounds such as raw materials such as lithium, silicon, aluminum, boron and barium are mixed so as to have a predetermined composition, melted at 900 to 1200 ° C., and quenched. It is made into a glass frit and then pulverized to a fine powder of 1 to 5 μm. High-purity carbonates, oxides, hydroxides and the like can be used as raw materials. Depending on the type and composition of the glass fine particles, ultra-high purity alkoxide or organometallic raw material of 99.99% or more is used, and if the powder is uniformly prepared by the sol-gel method, high electric resistance and dense pores are obtained. This is preferable because a high-strength insulating layer having a low level of resistance is obtained.

The particle diameter of the glass fine particles used in the present invention is selected in consideration of the line width and height of the partition wall to be produced. However, it should be carefully selected because it affects the viscosity characteristics of the paste. Is important.

The yield value of the photosensitive paste is 0.5 to 5 Pa
In order to control the particle size, the particle size of the glass particles and their distribution characteristics are important, and the tap density (according to JIS standards)
Is 0.6 g / cm ³ or more, more preferably 0.65 g / cm ³
cm ³ or more is preferable because the dispersibility of the glass fine particles in the paste is increased. In order to increase the tap density, it is necessary that particles having a large particle diameter are mixed, and the particle size distribution of the glass fine particles is closely related to the filling property.

For this reason, in the present invention, the average particle diameter of the glass fine particles is 1.5 to 7 μm, and the maximum particle diameter is 7 to 40 μm.
m is a necessary requirement that is preferable in order to increase the filling property of the glass fine particles and enhance the dispersibility of the glass fine particles in the paste.

By using glass fine particles having such characteristics, the filling property of the powder is improved, and even if the powder ratio in the photosensitive paste is increased, the entrapment of air bubbles is reduced, and extra light scattering is prevented. Since this is suppressed, a partition pattern having a preferable shape can be formed. When the particle size of the glass fine particles is smaller than the above range, the specific surface area increases, so that the cohesiveness of the powder increases and the dispersibility in the organic component decreases.
It becomes easy to entrap air bubbles. For this reason, light scattering increases, and the center of the partition wall becomes thicker, and the bottom is hardly hardened. When the tap density of the glass fine particles is smaller than the above, the bulk density of the powder is reduced, so that the filling property is reduced, the amount of the photosensitive organic component is insufficient, bubbles are easily entrained, and light scattering is also easily caused. In particular, when the particle size distribution of the glass fine particles is in the above range, the powder filling ratio can be increased, so that the firing shrinkage ratio decreases, and the pattern shape does not collapse during firing, and a stable partition wall shape can be obtained.

The method for measuring the particle size is not particularly limited.
It is convenient to use a laser diffraction / scattering method (eg, Microtrac Co., Ltd., particle size distribution analyzer HRA9320-X100).

Further, it is preferable to add, to the inorganic fine particles of the photosensitive paste of the present invention, filler fine particles composed of inorganic fine particles in addition to the glass fine particles having the above composition.
At this time, the content of the filler fine particles is 5 to 4 in the inorganic fine particles.
The content of 0% by weight is preferable for maintaining the strength and the shape of the partition walls obtained by firing. The amount of the filler component can control the shrinkage ratio at the time of firing after pattern formation by the amount of the filler component, and the pattern formation becomes easy.
As the filler component, ceramics such as titania, alumina, barium titanate, and zirconia, and high melting point glass can be used. Among these, the high melting point glass is
By adjusting the inorganic composition, the average refractive index, the softening point, and the coefficient of thermal expansion can be controlled, which is preferable. In particular, the average refractive index is 1.
Using high melting point glass particles having a glass transition point of 500 to 1200 ° C., a softening point of 550 to 1200 ° C., and a coefficient of thermal expansion of 35 to 75 × 10 ⁻⁷ / K at 25 to 400 ° C. Is preferred for pattern formation and shape retention.

The photosensitive paste of the present invention preferably contains 60 to 85% by weight of inorganic fine particles and 40 to 15% by weight of a photosensitive organic component, and the amount of the inorganic fine particles is 65 to 80% by weight. Is preferred. If the amount of the inorganic fine particles is less than 60% by weight, the shrinkage ratio during firing becomes large, which causes disconnection and peeling of the partition walls, which is not preferable. In addition, the pattern is likely to be thick and a residual film is likely to be generated during development. If the content is more than 85% by weight, the amount of the photosensitive component is too small, and the pattern formability deteriorates.

The photosensitive organic component which is an essential component of the photosensitive paste of the present invention includes, in addition to a photosensitive component selected from at least one of a photosensitive monomer, a photosensitive oligomer and a polymer, a photopolymerization initiator , A polymerization inhibitor and an ultraviolet absorber are preferably added. A sensitizer can be added as needed.

The photosensitive monomer and the photosensitive oligomer or polymer are preferably used as a mixture.

Examples of the photosensitive monomer include compounds having an active carbon-carbon double bond, and monofunctional and polyfunctional compounds having a vinyl group, an allyl group, an acrylate group, a methacrylate group, or an acrylamide group as a functional group. Applied. Particularly, in the present invention, it is preferable that the photosensitive organic component contains a polyfunctional acrylate compound and / or a polyfunctional methacrylate compound in an amount of 10 to 80% by weight. Since various kinds of compounds have been developed for the polyfunctional acrylate compound or the polyfunctional methacrylate compound, it is possible to select them from the viewpoint of reactivity, refractive index and the like.

As a method for controlling the refractive index of the organic component contained in the photosensitive paste, a method for controlling the refractive index of the photosensitive monomer is simple. In particular, the refractive index is 1.55
By using the photosensitive monomer of 1.8, the refractive index of the organic component can be increased. As the photosensitive monomer having a high refractive index, a polyfunctional acrylate or polyfunctional methacrylate monomer containing an aromatic ring such as a benzene ring or a naphthalene ring or a sulfur atom is preferable.

Further, the photosensitive organic components constituting the photosensitive paste serve to improve the physical properties of the cured product formed by the photoreaction, adjust the viscosity of the paste, and to improve the developability of the unexposed portions. It is preferable that an oligomer or a polymer is contained as a component that performs a controlling function. These oligomers or polymers have a carbon chain skeleton obtained by polymerization or copolymerization of components selected from compounds having a carbon-carbon double bond. As the monomer to be copolymerized, an unsaturated carboxylic acid or the like is useful, and it is possible to give a photosensitive paste which can develop an unexposed portion after exposure to an aqueous alkali solution. Specific examples of unsaturated carboxylic acids include acrylic acid, methacrylic acid, itaconic acid, crotonic acid, maleic acid, fumaric acid, vinyl acetic acid, and acid anhydrides thereof.

In the present invention, it is most preferable to use a photosensitive oligomer or polymer having a carboxyl group and an unsaturated double bond in the molecule and having a weight average molecular weight of 500 to 100,000. To apply the above method, an addition reaction of an oligomer or polymer having a carboxyl group in the side chain with an ethylenically unsaturated compound having a glycidyl group or an isocyanate group, acrylic acid chloride, methacrylic acid chloride or allyl chloride as described above is applied. Is done. Addition of an ethylenically unsaturated compound is preferred in that polymers and oligomers become photosensitive. The number of carboxyl groups for developing with an aqueous alkali solution and the number of ethylenically unsaturated groups that render the oligomer or polymer photosensitive can be freely selected depending on the reaction conditions.

The acid value of the thus obtained photosensitive oligomer or polymer having a carboxyl group in the side chain is 30.
It is good to control so as to be in the range of 150 to 150, preferably 80 to 120. When the acid value exceeds 150,
The allowable development width is reduced. On the other hand, when the acid value is 30 or less, the solubility of the unexposed portion in the developer decreases.

The above-mentioned photosensitive monomers, photosensitive oligomers or polymers, or binders contained as necessary, have no ability to absorb energy of actinic rays. Contains a photopolymerization initiator and a sensitizer.

The pattern formation by the photosensitive paste is to polymerize and crosslink the photosensitive component (monomer, oligomer, polymer) in the exposed portion to make it insoluble in a developing solution. The polymerization initiator is selected from those generating radical species. Photopolymerization initiators include mechanically different types such as a one-molecule direct cleavage type, an electron transfer between ion pairs, a hydrogen abstraction type, and a two-molecule composite system. In the photosensitive paste of the present invention, mainly one molecule is used. It is preferable to use a compound selected from the system direct cleavage type. For example, benzoin alkyl ether, α, α-dimethoxy-α-morpholinoacetophenone, α, α-dimethoxy-α-phenylacetophenone and the like are practically used. Further, peroxides, phosphine oxides, sulfur compounds, halogen compounds and the like can also be used. One or more of these can be used. The photopolymerization initiator is preferably used in an amount of 5 to 30% by weight with respect to the photosensitive component in consideration of the amount of the inorganic fine particles.

By using a sensitizer together with the photopolymerization initiator, the sensitivity can be improved (chemical sensitization) or the wavelength range effective for the reaction can be expanded (spectral sensitization). There are various modes of action of sensitizers, but those called triplet sensitizers are most often used, and specifically include hydrocarbon compounds, amino-nitro compounds, quinones, and xanthones , Anthrones, ketones, and organic dyes. Among them, those having an action as a photopolymerization initiator are also included. In the present invention, compounds selected from xanthones are preferably used, and examples thereof include 2,4-diethylthioxanthone and isopropylthioxanthone. These can be used alone or in combination of two or more.

When a sensitizer is added to the photosensitive paste of the present invention, it is necessary to select the addition amount in balance with the addition amount of the photopolymerization initiator. It is preferable to use it in the range of 2 to 30% by weight based on the components.

If the photopolymerization initiator and the sensitizer are too small, sufficient sensitivity cannot be obtained. However, if the photopolymerization initiator and the sensitizer are too large, the sensitivity can be increased. In other words, there is a possibility that the residual ratio of the exposed portion may be reduced, and inconveniences such as the occurrence of unnecessary curing between patterns and the formation of a residual film may occur. It is necessary to use appropriate amounts of the photopolymerization initiator and the sensitizer in order to form a pattern having an excellent shape with an appropriate sensitivity.

Further, it is effective to add an ultraviolet absorber to the photosensitive paste for pattern processing of an excellent shape. By adding a compound having a high ultraviolet light absorption effect, a high aspect ratio, high definition, and high resolution can be obtained. As the ultraviolet light absorber, those having an absorption maximum in a wavelength range of 350 to 400 nm are preferably used.

More specifically, at least one compound selected from azo, aminoketone, xanthene, quinoline, anthraquinone, benzophenone, diphenylcyanoacrylate, triazine, and p-aminobenzoic acid Alternatively, a dye or the like can be used. Of these, azo, benzophenone and diphenylcyanoacrylate are preferred. Even when an organic dye is added as an ultraviolet light absorber, it does not remain in the insulating film after firing, so that a decrease in insulating properties can be reduced, which is preferable.

The amount of the ultraviolet absorber added is 0.03 to 6% by weight based on the amount of the inorganic fine particles dispersed in the photosensitive paste.
It is preferred that More preferably, 0.05 to 5
% By weight. As the ultraviolet light absorber, there is a method of preparing a solution in which the ultraviolet light absorber is dissolved in an organic solvent in advance, and kneading the solution at the time of preparing a photosensitive paste, or a method of mixing and drying inorganic fine particles in the dye solution. In the latter method, so-called capsule-shaped inorganic fine particles in which the surface of each of the inorganic fine particles is coated with an organic dye film can be produced. As a result, reflection at the interface between the inorganic fine particles, particularly, the glass fine particles, is suppressed, and unnecessary photoreaction is prevented, so that it is estimated that thickening of the pattern and generation of a residual film are prevented.

The photosensitive paste may be polymerized, if necessary, to improve the thermal stability during storage or to suppress the photopolymerization reaction in areas other than the desired pattern due to scattered light and to increase the definition. Inhibitors can be added. Further, an antioxidant for preventing oxidation of the acrylic copolymer and other plasticizers can be added.

The polymerization inhibitor is not particularly limited as long as it can be used as a polymerization inhibitor. Specific examples include:
p-benzoquinone, naphthoquinone, para-xyloquinone, para-toluquinone, 2,6-dichloroquinone, 2,
5-diacetoxy-p-benzoquinone, 2,5-dicaproxy-p-benzoquinone, hydroquinone, pt-butylcatechol, 2,5-dibutylhydroquinone, mono-t-butylhydroquinone, 2,5-di-t-amyl Hydroquinone, di-t-butyl paracresol, hydroquinone monomethyl ether and the like can be mentioned. When a polymerization inhibitor is added, the amount added is 0.01 to 20% by weight in the photosensitive paste.

Further, the photosensitive paste of the present invention can be used by adding an organic solvent in order to adjust the viscosity when applied to a glass substrate or the like according to the application method. The organic solvent used at this time is methyl cellosolve,
Ethyl cellosolve, butyl cellosolve, methyl ethyl ketone, dioxane, acetone, cyclohexanone, cyclopentanone, isobutyl alcohol, isopropyl alcohol, tetrahydrofuran, dimethyl sulfoxide, γ-butyrolactone, and an organic solvent mixture containing at least one of these are used. Can be

The photosensitive paste of the present invention includes, for example, inorganic fine particles including glass fine particles, photosensitive monomers, photosensitive oligomers or polymers, photopolymerization initiators, sensitizers, ultraviolet light absorbers, other additives and solvents. Are prepared so as to have a predetermined composition, and then uniformly mixed and dispersed with a three-roller or a kneader to produce. The viscosity of the paste is adjusted by adding inorganic fine particles, a photosensitive component, a thickener, an organic solvent, a plasticizer, and the like.
ps (centipoise). For example, a glass substrate is coated once by a screen printing method to form a film having a thickness of 10 to 2 times.
To obtain 0 μm, 50,000 to 200,000 cps is preferable. When using a blade coater method, a slit die coater method, or the like, 10,000 to 20,000 cps is preferable.

The above-mentioned photosensitive paste of the present invention is preferably used for forming a partition pattern of a plasma display or a plasma-addressed liquid crystal display, because its effect is remarkable.

[0058]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be specifically described below with reference to embodiments. However, the present invention is not limited to this. The concentrations in the examples are% by weight unless otherwise noted.

The meanings of the abbreviations in the examples are as follows.

X-4007: 40% methacrylic acid, 30
% Methyl methacrylate, 30% styrene and a carboxyl group of 0.4 equivalent of glycidyl methacrylate added to carboxyl groups to obtain a weight average of 43,00.
0, a photosensitive polymer having an acid value of 95.

MGP400: a compound represented by the following chemical formula.

[0062]

Embedded image IC-369: product of Ciba-Geigy 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) butanone-1 DETX-S: 2,4-diethylthioxanthone Example 1 The following composition (analytical value) as inorganic fine particles ) Was prepared. 6.7% lithium oxide, silicon oxide 22
%, 32% boron oxide, 3.9% barium oxide, 19% aluminum oxide, 2.2% zinc oxide, 5.5% magnesium oxide, 4.1% calcium oxide. The glass transition point of the glass fine particles is 497 ° C., the softening point is 530 ° C., the refractive index is 1.58, the average particle diameter is 2.6 μm, and the maximum particle diameter is 22 μm.
m, tap density is 0.76 g / cm ³ . The glass fine particles are treated with 0.08% UV absorber Sudan IV (Azo dye, manufactured by Tokyo Chemical Industry Co., Ltd.) based on the glass fine particles.
Coating treatment.

A photosensitive polymer (X-400) was added to 70 parts by weight of glass particles having the above composition and treated with Sudan IV.
7) 15 parts by weight, photosensitive monomer (MGP400) 15
A photosensitive paste was prepared by kneading 3 parts by weight of 3 parts by weight, 4 parts by weight of a photopolymerization initiator (IC-369), 2 parts by weight of a plasticizer (dibutyl phthalate), and 30 parts by weight of a solvent (γ-butyrolactone). When the shear stress (Y) with respect to the shear rate (X) of this photosensitive paste is measured, Y = 240
A linear relationship of X + 2 was obtained, indicating a yield value of 2 Pa.

The photosensitive paste having such a viscosity characteristic is repeatedly screen-printed and dried on a glass substrate, applied to a predetermined thickness so as to have a dry thickness of 180 μm, and dried at 80 ° C. for 40 minutes. Thus, a coating film having no pinhole was obtained. G measured for a coating film having a thickness of 50 μm for transmittance measurement manufactured by such a coating method.
The total light transmittance in the linear wavelength region was 57%.

A photomask (stripe pattern, pitch 150 μm, line width 2) for forming a partition pattern for a plasma display is formed on the photosensitive paste coating film.
0 μm). Exposure was performed using an ultra-high pressure mercury lamp with an output of 20 mW / cm ² .
Irradiation at ³ J / cm ² was performed.

Then, 0.3% of monoethanolamine
The non-exposed portion was dissolved and removed by spraying the aqueous solution with a shower spray for 120 seconds, and further washed with water using a shower spray to form a partition wall pattern.

The shape of the obtained partition pattern was observed with an electron microscope. It has a sharp edge, a height of 180 μm,
It was confirmed that a high-definition partition pattern having a line width of 42 μm and a high aspect ratio was obtained.

Example 2 A photosensitive paste was prepared in the same manner as in Example 1 except that the composition (analytical value) of the glass fine particles was changed as follows.
A partition pattern was formed.

Lithium oxide 4%, silicon oxide 23%, boron oxide 32%, barium oxide 4%, aluminum oxide 20
%, Zinc oxide 2%, magnesium oxide 3%, calcium oxide 4%, zirconium oxide 1%.

The glass transition point of the glass particles is 494.
° C, softening point: 533 ° C, refractive index: 1.57, average particle size: 2.8 µm, maximum particle size: 22 µm, tap density: 0.7
8 g / cm ³ .

The relational expression between the shear rate and the shear stress of the obtained photosensitive paste is Y = 180X + 2, and the yield value is 2
Pa was indicated. The total light transmittance per 50 μm of this paste coating film thickness is 62%, the height is 180 μm,
A high-definition partition pattern with a line width of 40 μm and a high aspect ratio could be obtained.

Example 3 70 parts by weight of glass fine particles used in Example 1 as inorganic fine particles and 5 parts by weight of high melting glass powder having the following composition as filler fine particles were added. A photosensitive paste was prepared in the same manner as in Example 1 except that the addition amount was 12.5 parts by weight, and a partition pattern was formed.

Filler powder: silicon oxide 38%, boron oxide 10%, barium oxide 5.5%, aluminum oxide 3
4.5%, zinc oxide 2.2%, magnesium oxide 4.8
%, Calcium oxide 4.4%, titanium oxide 0.6%. Glass transition point: 656 ° C., softening point: 770 ° C., average refractive index: 1.58, average particle size: 2.4 μm, maximum particle size:
9.5 μm, tap density: 0.65 g / cm ³ .

The relational expression between the shear rate and the shear stress of the photosensitive paste is Y = 399X + 3, and the yield value is 3P.
a. The total light transmittance per 50 μm of the paste coating film thickness was 54%.

From the photosensitive paste having such characteristics, a high-definition partition pattern with a high aspect ratio of 180 μm in height and a line width of 45 μm could be obtained.

Example 4 Example 1 was repeated except that 0.6 parts by weight of a polymerization inhibitor (hydroquinone monomethyl ether) was added as a photosensitive organic component.
A photosensitive paste was prepared in the same manner as described above, and a partition pattern was formed. The relational expression between the shear rate and the shear stress of this photosensitive paste was Y = 240X + 2, and showed a yield value of 2 Pa.
The total light transmittance per paste coating thickness of 50 μm was 57%.

From the photosensitive paste having such characteristics, a high-definition partition pattern with a high aspect ratio of 180 μm in height and a line width of 36 μm could be obtained.

Comparative Example 1 In Example 1, the tap density of the glass fine particles was 0.57.
A photosensitive paste was prepared and a partition pattern was formed in the same manner as in Example 1 except that g / cm3 and the maximum particle diameter were 11 μm. The viscosity of the photosensitive paste was 340 ps (a value at a spindle rotation speed of 10 rpm), the relational expression between the shear rate and the shear stress was Y = 379X + (− 14), and the yield value was −14. The total light transmittance per 50 μm of the paste coating film thickness was 45%. Using the coating film of the photosensitive paste, a partition pattern was formed in the same manner as in Example 1, but the shape was remarkably thick and the pattern formability was poor.

COMPARATIVE EXAMPLE 2 In Comparative Example 1, 5 parts by weight of a solvent (γ-butyrolactone) was added to the paste to give a viscosity of 185 ps (a value at a spindle rotation speed of 10 rpm). The relational expression is: Y = 210X + (− 7)
And the yield value was -7 Pa. The total light transmittance per 50 μm of the paste coating film thickness was 48%. Also in this case, the pattern formability was poor.

Comparative Example 3 A photosensitive paste was prepared in the same manner as in Example 1 except that the photosensitive paste was changed to the following composition.
A partition pattern was formed. 90 parts by weight of glass particles treated with Sudan IV, 5 parts by weight of photosensitive polymer (X-4007), 5 parts by weight of photosensitive monomer (MGP400), 1.4 parts by weight of photopolymerization initiator (IC-369), plasticizer 2 parts by weight of (dibutyl phthalate) and 30 parts by weight of a solvent (γ-butyrolactone) were kneaded with three rollers to prepare a photosensitive paste. When the shear stress (Y) with respect to the shear rate (X) of the photosensitive paste was measured, a linear relationship of Y = 270X + 15 was obtained, and the yield value was 15 Pa.

The total light transmittance per 50 μm of the paste coating thickness was 42%. Also in this case, the pattern formability was poor.

[0082]

The photosensitive paste of the present invention has a yield value of 0.5 to 5 Pa in a photosensitive paste containing inorganic fine particles and a photosensitive organic component as essential components. Shows pattern formability. In particular, when used for forming a partition pattern of a plasma display or a plasma addressed liquid crystal display, the effect is remarkably exhibited, which is preferable.

Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI H01J 17/49 H01J 17/49 Z // C08F 290/08 C08F 290/08 C08L 33/00 C08L 33/00 C09D 201/00 C09D 201/00

Claims (10)

[Claims] 1. A photosensitive paste comprising inorganic fine particles and a photosensitive organic component as essential components, wherein the yield value of the paste is 0.5 to 5 Pa. 2. The photosensitive paste according to claim 1, wherein the total light transmittance of the coating film having a thickness of 50 μm of the photosensitive paste is 50% or more. 3. The photosensitive paste according to claim 1, wherein 60% by weight or more of the inorganic fine particles are glass fine particles. 4. A tap density of said glass fine particles is 0.6 g.
4 / cm ³ or more. 5. The glass fine particles having an average particle size of 1.5 to 1.5.
The photosensitive paste according to claim 3, wherein the photosensitive paste has a maximum particle diameter of 7 μm and a maximum particle diameter of 7 to 40 μm. 6. The photosensitive paste according to claim 1, wherein 5 to 40% by weight of the inorganic fine particles are filler fine particles. 7. The filler fine particles have a softening point of 550-12.
The photosensitive paste according to claim 6, which is a high melting point glass powder having a temperature of 00C and an average refractive index of 1.5 to 1.7. 8. The photosensitive paste according to claim 1, comprising 60 to 85% by weight of inorganic fine particles and 40 to 15% by weight of a photosensitive organic component. 9. The method according to claim 1, wherein the photosensitive organic component is mainly composed of a photosensitive monomer, a photosensitive oligomer or a polymer, and contains a photopolymerization initiator, a polymerization inhibitor and an ultraviolet absorber. The photosensitive paste as described in the above. 10. The photosensitive paste according to claim 1, which is used for forming a partition pattern in a plasma display or a plasma addressed liquid crystal display.