KR100380555B1 - Black paste composition for the formation of black layer - Google Patents

Abstract

The present invention relates to a black paste composition useful for forming a black thin film, comprising 15 to 25 parts by weight of ruthenium-based polyoxide fine powder having a specific surface area of 5 to 40 m ² / g, an average particle diameter of 0.2 to 2 μm, and a maximum size of 5 μm or less. The black paste of the present invention comprises 40 to 85 parts by weight of a glass frit of and 8 to 40 parts by weight of an organic vehicle, which is dense, high in blackness and excellent in various physical properties on a glass substrate or a ceramic substrate. It is possible to provide a black thin film pattern.

Description

Black paste composition for black layer formation {BLACK PASTE COMPOSITION FOR THE FORMATION OF BLACK LAYER}

TECHNICAL FIELD This invention relates to a black paste composition. Specifically, It is related with the black paste composition used as a display member.

In recent years, there has been an increasing demand for low-temperature firing of conductor circuit patterns, low resistance of conductors, high refinement and high density in displays and circuit boards, and is a light and thin type as an image display device replacing heavy CRTs. Flat display was developed. Liquid crystal displays (LCDs) are being actively developed as flat panel displays, which have problems of dark images and narrow viewing angles.

As an alternative to the liquid crystal display, there is an image display device using a plasma display panel (hereinafter referred to as PDP) or an electron-emitting device that is a self-emitting discharge type display, which produces a brighter image than a liquid crystal display. Its demands are increasing because of its wide viewing angle and its ability to meet the needs of large screens and high resolutions.

The electron emitting device has a field emission type (FED) represented by a cold cathode electron emitting device, and an image forming apparatus using a cold cathode electron source emits fluorescence by irradiating an electron beam emitted from the electron emitting device to a phosphor. To display an image. In this apparatus, the front glass substrate and the back glass substrate are provided with functions, respectively, and the back glass substrate is designed with matrix wirings for connecting a plurality of electron-emitting devices and electrodes of those devices. Since these wirings intersect at the electrode portion of the electron-emitting device, a dielectric layer for insulating is designed. In addition, a spacer is formed between the substrates as an internal air pressure supporting member.

PDPs are capable of high-speed display and large-sized displays compared to liquid crystal displays, and thus demands are increasing in fields such as OA devices and information display devices. Regarding the PDP, an AC type gas display panel is shown in FIG. As shown in Fig. 1, the PDP has a structure in which a pair of electrodes regularly aligned are placed on two opposing glass substrates, and an inert gas such as neon, helium, and xenon is enclosed between the two substrates. By applying a voltage between and discharging in a small cell around the electrode, each cell is made to emit light to display. On the other hand, the both substrates are composed of a display side substrate 1 (hereinafter referred to as a front substrate) and a back side substrate 2 made of a transparent material such as glass. In general, a discharge holding electrode pair composed of a transparent electrode 3 and a bus electrode 4 and extending in a lateral direction and parallel to each other is disposed on the front substrate. They are covered with a transparent dielectric layer 5, furthermore a transparent protective layer 6. Similarly, a plurality of address electrodes 8 orthogonal to the discharge sustaining electrode pair are located on the back side substrate covered with the dielectric layer 7. The discharge cells are pixelated by the partition wall 9 at the intersections of the discharge sustaining electrode pairs with the address electrodes 8, or in the vicinity thereof, to selectively discharge these discharge cells to emit the phosphors 10. Display is performed.

In the above-described PDP, the electrode of the front plate is usually formed of, for example, silver paste. In this case, when the glass substrate comes into direct contact with the silver paste, it reacts to turn brown. On the other hand, in order to improve visibility, a material in which a black pigment is added to the silver paste to make the electrode black has been studied, but there is a problem that not only a sufficient degree of blackness is obtained but also browning is not avoided. In addition, when the black layer is used, the silver electrode of the front plate is usually formed on the glass substrate side, and then formed thereon. The black pigment moves to the silver electrode layer to lower the resistance of the silver electrode and the electrode end. There has been a problem such as causing an edge curl phenomenon. The edge curl is considered to occur when the organic component is removed by pyrolysis in the firing step of the patterned electrode, so that the electrode contracts and both ends in the electrode width direction fall from the electrode formation surface.

Accordingly, an object of the present invention is to solve the above problems, to form a black layer at a low temperature without lowering the resistance of the electrode, and to form a thin black film with high blackness without discoloring the glass substrate. To provide a black paste.

1 is a perspective view showing the basic structure of a typical gas discharge display panel.

In one aspect of the present invention for achieving the above object, 15 to 25 parts by weight of the ruthenium-based polyoxide fine powder in the specific surface area of 5 to 40 m ² / g, the average particle diameter range of 0.2 to 2 ㎛ and the maximum size of 5 ㎛ or less It provides a black paste composition ("normal black paste") comprising 40 to 85 parts by weight of the glass frit and 8 to 40 parts by weight of the organic vehicle.

The present invention also provides a specific black paste composition ("photosensitive black paste"), characterized in that the photosensitive organic component is used in place of the organic vehicle in the normal black paste.

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

The black paste composition of the present invention is characterized by using ruthenium-based polyoxide fine powder and glass frit.

The general black paste composition of the present invention preferably comprises 15 to 25 parts by weight of ruthenium-based polyoxide fine powder, 40 to 85 parts by weight of glass frit and 8 to 40 parts by weight of organic vehicle. The photosensitive black paste composition of the present invention preferably comprises 15 to 25 parts by weight of ruthenium-based polyoxide fine powder, 40 to 84 parts by weight of glass frit and 8 to 40 parts by weight of the photosensitive organic component.

The black paste composition of the present invention can be usefully used to form a black thin film by coating on a glass substrate of a PDP as shown in FIG.

In the case where a conventional silver paste is used as an electrode, the phenomenon of discoloration of the glass substrate is such that the silver in the silver paste reacts with an alkali component or the like in the silver paste during firing and ionized so that the ionized silver is a barrier layer such as a lower layer (between the glass substrate and the silver electrode layer). Layer is diffused into the glass substrate to cause a redox reaction with tin, whereby silver colloids. In order to suppress this reaction, an alkali content of 0.1 weight% or less is used as a glass frit component added to silver paste.

In the present invention, since the ruthenium multi-oxide fine powder is used as a paste constituent, occurrence of the above problem can be avoided. In other words, it loses the movement (diffusion) power of silver ions, the main component of the electrode, avoids reaction with tin in the glass substrate, prevents browning of the silver electrode, and improves contrast due to black powder, and decreases the conductivity of the silver electrode. A black thin film can be obtained which is not made.

The black paste of the present invention may be formed with an insulating pattern on a black stripe or lattice to improve contrast.

In the black paste of the present invention, a conductive powder may be used to impart conductivity, and in this case, the thickness of the black electrode layer formed after firing is preferably in the range of 2 to 5 μm. The electrode composite can be formed by baking a pattern after forming a pattern by exposing two layers of a black electrode and a bath conductor electrode, and developing.

In the present invention, the term "black" means black which represents a visually superior contrast with respect to white, and the brightness index L is 25 or less, more preferably 20 or less. The brightness index is defined in the International Illumination Commission (CIE) or JIS Z 8729. In the Lab colorimetric system, the brightness index is represented by L and the chromaticity a and b. Y specified in JIS Z 8701 can be used as Y in these regulations.

The component, the kneading process of the black paste composition of this invention, and its use method are demonstrated concretely below.

(1) Ruthenium-based polyoxide fine powder

The ruthenium-based polyoxide fine powder used in the black paste of the present invention may be RuO ₂ and other ruthenium polyoxides. The ruthenium-based fine oxide powder includes compounds described in US Pat. No. 3,583,931. Specific examples of preferred ruthenium-based polyoxide fine powders include RuO ₂ , GdBiRu ₂ O ₇ , Pb ₂ Ru ₂ O ₆ , and Co ₂ Ru ₂ O ₆ At least one selected from the group consisting of PbBiRu ₂ O _6.5 , Cu _x Bi _2-x Ru ₂ O ₇ (x = 0-1), and Bi ₂ Ru ₂ O ₇ .

The ruthenium-based polyoxide fine powder preferably has a specific surface area in the range of 5 to 40 m ² / g, more preferably in the range of 10 to 30 m ² / g. If the specific surface area is less than 5 m ² / g, the particles become too large to obtain a thin film having a high blackness. If the specific surface area is larger than 40 m ² / g, the black fine particles are too fine and print characteristics are deteriorated. Accuracy decreases and sinterability falls, and it becomes difficult to obtain a dense film.

The ruthenium-based polyoxide fine powder is contained in the black paste, thereby reducing the influence of the paste from the glass and the organic vehicle, and providing an electrode having a high blackness.

The ruthenium-based polyoxide fine powder preferably has an average particle diameter in the range of 0.01 to 0.1 µm, more preferably 0.02 to 0.08 µm. If the average particle diameter is out of the above range, the blackness is lowered, which is not preferable. In addition, the ruthenium-based polyoxide fine powder may be used with a ruthenium-based polyoxide powder having an average particle diameter of 0.3 to 1 ㎛ and a maximum size of 3 ㎛ or less. By using the said powder together, the shrinkage rate at the time of baking can be reduced. The ruthenium-based polyoxide powder is preferably used in an amount in the range of 5 to 40% by weight with respect to the ruthenium-based polyoxide fine powder, and when used at less than 5% by weight, the shrinkage inhibiting effect is reduced. The surface smoothness of the film is lowered, which is not preferable.

(2) glass frit

In addition, the glass frit used in the black paste composition of the present invention serves as a binder for bonding the ruthenium-based polyoxide fine powders contained in the black powder to each other, and improves the adhesion of the paste to the ceramic or glass substrate and simultaneously sinters There is an effect of softening at the time to aggregate the glass frit on the substrate side.

As the glass frit, glass frit A and glass frit B can be preferably used. As the glass frit A, it is possible to use bismuth oxide (Bi ₂ O ₃ ), and it is preferable that the composition component and content indicated in the oxide conversion notation contain 90 wt% or more of the composition as shown in Table 1 below, and the glass frit B The containing containing lead oxide (PbO) is used, It is preferable that the composition component and content which are represented by the oxide conversion notation contain 90 weight% or more of a composition as Table 2 below.

Component Content (parts by weight) Bi ₂ O ₃ 40 to 90 SiO ₂ 5 to 30 B ₂ O ₃ 5 to 30 BaO 2 to 40

Component Content (parts by weight) PbO 40 to 90 SiO ₂ 10 to 40 B ₂ O ₃ 5 to 30 ZnO 0 to 10 Al ₂ O ₃ 0 to 20

By use of the said glass frit, it becomes possible to bake waste yeast at the temperature from which a glass substrate is not stressed.

In the glass frit A composition, when bismuth oxide (Bi ₂ O ₃ ) is used in an amount less than 40 parts by weight, the effect of increasing the adhesive strength when baking the paste on the glass substrate is small, and when it exceeds 90 parts by weight, the softening point of the glass frit It is not preferable because this is too low and the de-vehicle property of the paste is bad and the adhesive strength with the substrate is lowered. The preferred amount of bismuth oxide is in the range of 50 to 80 parts by weight.

When the silicon oxide (SiO ₂ ) is less than 5 parts by weight in the glass frit A composition, the stability of the glass frit is lowered, and when it is more than 30 parts by weight, the heat resistance temperature rises and it is difficult to be baked on the glass substrate at 570 ° C. or less. It becomes difficult. Preferably, silicon oxide is used in amounts ranging from 5 to 15 parts by weight.

In the glass frit A composition, boron oxide (B ₂ O ₃ ) is added to control the baking temperature on the glass substrate so as not to impair the properties such as adhesive strength and thermal expansion coefficient, but below 5 parts by weight, the adhesive strength is lowered. When it exceeds 30 weight part, the stability of a glass frit will fall. Boron oxide is preferably used in an amount in the range of 7 to 20 parts by weight.

When the barium oxide (BaO) is used in the glass frit A composition at less than 2 parts by weight, it is difficult to control the glass baking temperature, and when it exceeds 40 parts by weight, the stability of the glass layer is lowered. Preferably used in amounts ranging from 2 to 30 parts by weight.

In addition, when the lead oxide (PbO) is less than 40 parts by weight in the glass frit B composition, the effect of increasing the adhesive strength when baking the paste on the glass substrate is small, and when it exceeds 90 parts by weight, the softening point of the glass frit is too low. It is not preferable because the de-vehicle property deteriorates and the adhesive strength with the substrate decreases. The preferred amount of lead oxide is in the range of 50 to 80 parts by weight.

When the silicon oxide (SiO ₂ ) is less than 10 parts by weight in the glass frit B composition, the stability of the glass frit is lowered, and when it is more than 40 parts by weight, the heat-resistant temperature rises and it is difficult to be baked on the glass substrate at 570 ° C. or less. It becomes difficult. Preferably, silicon oxide is used in amounts ranging from 10 to 30 parts by weight.

When boron oxide (B ₂ O ₃ ) is used in less than 5 parts by weight in the glass frit B composition, the adhesive strength is lowered, and when used in excess of 30 parts by weight, the stability of the glass frit is lowered. Boron oxide is preferably used in an amount in the range of 5 to 20 parts by weight.

When zinc oxide (ZnO) is used in excess of 10 parts by weight in the glass frit B composition, the stability of the glass layer is lowered, and the preferred amount of use is in the range of 2 to 5 parts by weight.

In the glass frit B composition, aluminum oxide (Al ₂ O ₃ ) is added to increase the deformation temperature of the composition and to stabilize the glass composition or paste, and if it exceeds 20 parts by weight, the heat-resistant temperature of the glass becomes too high to be baked on the glass substrate. It becomes difficult to do Preferred amounts of use range from 2 to 15 parts by weight.

In addition, according to the present invention, a composite glass frit containing both the glass frit A and the glass frit B may be used as the glass frit, and the components and contents expressed in the oxide conversion notation may be 90 It is preferable to contain by weight or more.

Component Content (parts by weight) Bi ₂ O ₃ 40 to 90 PbO 40 to 90 SiO ₂ 5 to 30 B ₂ O ₃ 5 to 30 BaO 2 to 40 ZnO 0 to 10 Al ₂ O ₃ 0 to 20

It is preferable that the said glass frit A, the glass frit B, and the composite glass frit are 0.1-2 micrometers of average particle diameters, and 5 micrometers or less of the largest sizes. More preferably, the average particle diameter is in the range of 0.1 to 1 mu m, and the maximum size is 3 mu m or less. When the particle diameter of the glass frit is in the above range, the adhesion strength with the glass substrate at low temperature can be increased, and a dense film of low resistance can be obtained, and even when the thin film is formed, there is an advantage that the peeling of the thin film is unlikely to occur.

The softening point of the glass frit A and the glass frit B is measured by a differential thermal (DSP) method, and the softening point is preferably in the range of 400 to 550 ° C, more preferably in the range of 420 to 500 ° C. If the softening point is lower than 400 ° C., organic components are easily contained, and as organic components such as polymers are decomposed, blisters are likely to occur in the coating film of the paste. On the other hand, when the softening point is higher than 550 ° C., the adhesive strength to the substrate of the film after firing is lowered.

(3) organic vehicle

Organic vehicle components usable in the general black paste of the present invention include cellulose derivatives such as ethyl cellulose, methyl cellulose, nitro cellulose and carboxymethyl cellulose, and resins such as acrylate ester, methacrylic acid ester, polyvinyl alcohol, polyvinyl butyral, etc. Ingredients may be used. Among them, acrylic resins and ethyl cellulose can be preferably used in view of the dispersibility of the conductive powder and the conductive fine particles, the coating properties of the paste, and the de-vehicle (degradability) during firing. These resin components are dissolved and used in an organic solvent.

The organic vehicle component is used in the composition of the present invention in an amount of 8 to 40 parts by weight, which is not preferable because it cannot be completely evaporated (sintered, debindered) in the firing step.

(4) photosensitive organic components

The photosensitive organic component used in the photosensitive black paste of the present invention is used in an amount of 8 to 40 parts by weight. When the amount of the photosensitive organic component used is less than 8 parts by weight, photocuring at the time of exposure is not sufficiently performed to the lower part of the black layer, and thus, It is difficult to form an ultrafine pattern, the cross-sectional shape of the black layer film is poor, and developability is deteriorated. Moreover, when the said photosensitive organic component exceeds 40 weight part, since the organic component removed by baking increases and the density of a film | membrane worsens, it is unpreferable.

The photosensitive organic component is composed of a photosensitive resin and a photopolymerization initiator, and the photosensitive resin may be either a negative type or a posi type, and the negative type is preferably used because it is easy to handle and easy to design. Can be. Examples of the photosensitive resin include linear or branched reactive polymers, monomers and oligomers having photosensitive groups such as acryloyl groups in the molecular structure and forming insoluble polymers by exposure.

Examples of the linear or branched reactive polymer include (meth) in the side chain of the polymer or copolymer of (meth) acrylic acid and / or its ester, or the copolymer of these monomers with a styrene-based compound and / or acrylonitrile. Acrylics such as polymers modified to have acrylic acid groups; Polyesters such as (meth) acrylates of unsaturated polyesters, polyesters and polyester polyols; Polyether (meth) acrylates such as polyethylene glycol (meth) acrylate and polypropylene glycol (meth) acrylate; Epoxy diacrylate type | system | group obtained by reaction of bisphenol-type epoxy resin, novolak-type epoxy resin, or alicyclic epoxy resin and acrylic acid; Urethane (meth) acrylate type | system | group obtained by reaction of a polyether polyol or polyester polyol, diisocyanate, and a hydroxyl-group containing (meth) acrylate; And polymers such as polyimide-based compounds such as a copolymer of biphenyltetracarboxylic anhydride and 2- (meth) acrylamide-diaminodiphenyl ether.

The polymer has a molecular weight of less than 50,000, preferably less than 30,000, and by adjusting in this range, printing properties or pattern formability can be improved.

As the monomer or oligomer, in addition to the oligomer having a low polymerization degree of the polymer, triethylene glycol acrylate, neopentyl glycol diacrylate, 1,6-hexanediol diacrylate, trimethylolpropane triacrylate, and pentaerythritol Or acrylic esters such as tetra-acrylate, dipentaerythritol hexaacrylate; Monomers such as epoxy resins such as bisphenol A-di (meth) acrylate.

Examples of the photopolymerization initiator include radical photoinitiators which generate free radicals when exposed to active rays such as ultraviolet rays, for example, 1-hydroxycyclohexylphenylketone, 2-hydroxy-2-methyl-1-phenylpropane- Acetophenone series, such as 1-one; Benzophenones such as benzophenone and 3,3'-dimethyl-4-methoxybenzophenone; Thioxanthones, such as thioxanthone and diethyl thioxanthone, can be used. These photoinitiators can be used individually or in mixture of 2 or more types, or in combination with photoinitiators, such as amines.

(4) organic solvent

In addition, an organic solvent may be added to the black paste composition of the present invention in order to adjust the viscosity by dissolving the organic components and dispersing the fine phosphinel powder and the glass frit. Organic solvents include texanol (2,2,4-trimethyl-1,3-pentanediol monoisobutyrate), ethylene glycol (terpene), butyl carbitol, ethyl cellosolve, ethylbenzene, isopropylbenzene , Methyl ethyl ketone, dioxane, acetone, cyclohexanone, cyclopentanone, isobutyl alcohol, dimethyl sulfoxide, terepineol, fine oil, polyvinyl butyral, 3-methoxybutyl acetate, γ-butyrolactone And diethyl phthalate. These organic solvents can be used individually or in mixture of 2 or more types.

(5) conductive powder

In addition, the black paste composition of the present invention may include a conductive metal powder containing at least one selected from the group consisting of Ag, Au, Pd, Ni, and Pt when used to form a black electrode. The shape of these powders may be spherical, plate-like, blocky, rod-like, and the like, and spherical powders having low cohesiveness and good dispersibility may be preferably used.

The average particle diameter of the conductive powder is in the range of 0.8 to 4 μm, preferably in the range of 1 to 3 μm. If the particle size is less than 0.8 µm outside of this range, the particles become too fine to increase the shrinkage rate during sintering and easily cause cracks in the film, the particles are agglomerated, it is difficult to obtain a stable dispersion state in the paste, and the printing characteristics are deteriorated. . In addition, when the particle diameter is larger than 4 µm, the surface of the paste coating film becomes rough, it is difficult to obtain a very fine pattern, and the sintering property is lowered, which makes it difficult to obtain a dense thin film, which is not preferable.

The surface area / weight ratio (specific surface area) of the conductive powder is preferably 0.5 to 3.5 m ² / g, and the density is in the range of 2.5 to 6 g / cm ³ . If the specific surface area is less than 0.5 m ² / g, the particles become too large and the smoothness of the coated film after firing decreases, which is not preferable. If the specific surface area is larger than 3.5 m ² / g, the particles become too fine, the particles tend to aggregate and the printing characteristics are degraded. If the density is out of the above range, the printing characteristics are poor, which is not preferable.

The conductive powder may be used in an amount ranging from 5 to 30% by weight based on the total amount of the components (1), (2) and (3).

(6) other additives

In addition to the above-mentioned components, the black paste composition of the present invention may contain a polymerization inhibitor such as hydroquinone monomethyl ether to impart stability during storage; Dispersants such as polyacrylates, cellulose derivatives; Adhesion imparting agents such as a silane coupling agent for improving the adhesion to a substrate; Antifoaming agent to improve coating performance; Plasticizers for improving workability; Additives such as thixotropic imparting agents may be included.

(7) kneading and black layer formation

The black paste composition of the present invention is kneaded by using a kneader such as a roll mill, a mixer, a homogenizer and the like having three rolls. In addition, the viscosity of the paste composition is usually in the range of 10,000 to 150,000 centipoise, preferably in the range of 30,000 to 100,000 centipoise, in order to impart fluidity suitable for application. The viscosity of the coating liquid at the time of printing can be adjusted normally in the range of 10,000-70,000 centipoise, preferably in the range of 20,000-50,000 centipoise.

Using the black paste of the present invention, a desired electrode pattern is formed on a substrate such as a glass substrate or a ceramic substrate by a screen printing method, and after drying, the black layer is baked at a low temperature in the range of 500 to 560 ° C. for 15 to 30 minutes to form a black layer. can do.

The photosensitive black paste containing the photosensitive organic component is formed by forming a photosensitive conductive layer on a glass or ceramic substrate by coating or transferring, covering the photosensitive conductive layer with a predetermined photomask, exposing, developing and firing to remove the organic component. The ultrafine black pattern of a large area can be easily formed by the so-called photolithography method formed in a black pattern by this.

Specifically, the photosensitive black paste of this invention is apply | coated on base materials, such as a glass substrate or a ceramic substrate, using well-known methods, such as a screen printing method, a bar coater, and a roll coater method, and usually in oven After drying, the organic solvent is removed, and the pattern portion is exposed to photoactive light sources such as ultraviolet rays, infrared rays, and ion beams with a photomask inserted thereon, followed by photocuring. As the active light source, ultraviolet light is preferable because it can be easily irradiated with a relatively simple device. The uncured portion is developed and removed with a developer, and then washed to form a pattern. As the developing step, a spray method, a dipping method, or the like is used. As a developing solution, aqueous alkali solution is used. Aqueous sodium carbonate solution etc. can be used as aqueous alkali solution, It is preferable to use organic aqueous alkali solution because it is easy to remove an alkali component at the time of baking. As the organic alkali, a general amine compound can be used, and specific examples thereof include mono ethanolamine and diethanolamine. The concentration of the aqueous alkali solution is usually in the range of 0.1 to 1.0% by weight. It is preferable in process control that the temperature at the time of image development is performed in 20-50 degreeC. Thus, the film | membrane in which the pattern was formed can be baked on a glass substrate at the temperature of 480-560 degreeC for 15 to 30 minutes, and can form a black layer.

The photosensitive black paste of the present invention is capable of forming a good pattern without sufficiently reaching the lower end of the ultraviolet ray at the time of exposure and developing edge curl after development, and obtaining a film having good adhesion to the substrate and high blackness after firing. Lose.

The present invention will be described in more detail with reference to the following Examples, which are not intended to limit the present invention. In addition, the concentration% is% by weight unless otherwise noted.

Example 1

20 parts by weight of Pb ₂ Ru ₂ O ₆ powder having an average particle diameter of 0.05 μm as a ruthenium multioxide fine powder and a specific surface area of 8 m ² / g, and 80 parts by weight of glass frit A were uniformly mixed. In this case, the glass frit A was composed of 68.9 wt% Bi ₂ O ₃ , 10.0 wt% SiO ₂ , 11.8 wt% B ₂ O ₃ , 6.5 wt% BaO and 2.8 wt% Al ₂ O ₃ , with an average particle diameter of 1.0 μm. It had a maximum size of 3.6 μm, a softening point of 460 ° C., and a thermal expansion coefficient of 90 × 10 ⁻⁷ / K.

Subsequently, the mixed powder was pulverized and mixed in a ball mill and dried to obtain a pure black powder. 92 parts by weight of this powder and 8 parts by weight of ethyl cellulose were added to terebinol as an organic solvent to adjust the viscosity, and then kneaded with a triaxial roll to prepare a black paste for printing.

The paste obtained as described above was applied to a 25 cm × 25 cm sized soda glass substrate by screen printing to form a coating film. The thickness after drying the coating film at 80 degreeC for 40 minutes was 4.5 micrometers. It baked at the speed | rate of 250 degreeC / hour, hold | maintained at the maximum temperature of 540 degreeC for 15 minutes, and baked.

The obtained black film was 2.4 micrometers in thickness, and was black with the brightness index L of 12 measured by the Minolta CR200 type spectrophotometer. Moreover, discoloration, such as yellow, was not observed in the glass substrate.

Example 2

In Example 1, except that Co ₂ Ru ₂ O ₆ powder having an average particle diameter of 0.06 ㎛ and a specific surface area of 12 m ² / g as a ruthenium multi-oxide fine powder was carried out in the same manner, the black film obtained after firing has a thickness It was 2.3 micrometers, and was black with a brightness index L of 15, and the yellowing phenomenon was not observed in the glass substrate.

Example 3

In Example 1, except that PbBiRu ₂ O _6.5 powder having an average particle diameter of 0.03 μm and a specific surface area of 15 m ² / g was used as the ruthenium multioxide fine powder, the black film obtained after firing had a thickness of 2.8 μm. , The light index L was 10, and yellowing was not observed on the glass substrate.

Example 4

In Example 1, ruthenium multi-oxide fine powder was carried out in the same manner, except that RuO ₂ powder having an average particle diameter of 0.02 ㎛ and a specific surface area of 35 m ² / g, the black film obtained after firing has a thickness of 2.8 ㎛, It was black with a brightness index L of 17 and no yellowing was observed on the glass substrate.

Example 5

In Example 1, as the ruthenium polyoxide fine powder, Cu _x Bi _2-x Ru ₂ O ₇ (x = 0.5) powder having an average particle diameter of 0.04 µm and a specific surface area of 14 m ² / g was used, and this black fine powder was 15 parts by weight. The same process was conducted except that 85 parts by weight of glass frit B was mixed with the mixture. At this time, the glass frit B is composed of 73% by weight of PbO, 14% by weight of SiO ₂ , 7% by weight of B ₂ O ₃ , 3% by weight of ZnO and 3% by weight of Al ₂ O ₃ and has an average particle diameter of 1.1 ㎛, the maximum size It had a softening point of 3.8 占 폚 and a coefficient of thermal expansion of 80 x 10 ^-7 / K.

The black film obtained after baking was 2.6 micrometers in thickness, and was black with a brightness index L of 13, and the yellowing phenomenon was not observed in the glass substrate.

Example 6

Ruthenium multi-oxide fine powder, 70 parts by weight of Bi ₂ Ru ₂ O ₇ powder having an average particle diameter of 0.1 ㎛ and specific surface area of 11 m ² / g and 30 parts by weight of Bi ₂ Ru ₂ O ₇ powder having an average particle diameter of 0.6 ㎛ and a maximum size of 2.3 ㎛ A mixture was used. 25 parts by weight of the ruthenium multioxide mixed powder, 40 parts by weight of the composite glass frit, and 35 parts by weight of Ag powder as the conductive powder were uniformly mixed. In this case, the composite glass frit is composed of 68% by weight of Bi ₂ O ₃ , 11% by weight of PbO, 3.5% by weight of SiO ₂ , 13.5% by weight of B ₂ O ₃ , 2.5% by weight of BaO and 1.5% by weight of Al ₂ O ₃ The particle size was 1.0 μm, the maximum size was 3.6 μm, the softening point was 450 ° C., the thermal expansion coefficient was 80 × 10 ⁻⁷ / K, the conductive Ag powder had an average particle diameter of 1.8 μm, a specific surface area of 2.4 m ² / g, It was a spherical powder with a density of 3.6 g / cm ³ .

Subsequently, the mixed powder was pulverized and mixed in a ball mill and dried to obtain a pure black powder. 90 parts by weight of this powder and 10 parts by weight of polyvinyl butyral as an organic component were added to terebinol as an organic solvent to adjust the viscosity, and then kneaded with a triaxial roll to prepare a black paste.

The paste obtained as described above was applied to a 25 cm × 25 cm sized soda glass substrate by screen printing to form a coating film. The thickness after drying the coating film at 80 degreeC for 40 minutes was 4.0 micrometers. It baked at the speed | rate of 250 degreeC / hour, hold | maintained at the maximum temperature of 540 degreeC for 15 minutes, and baked.

The obtained black film was 2.5 micrometers in thickness, and was black with a brightness index L of 16, and the yellowing phenomenon was not observed in the glass substrate.

Example 7

In Example 1, glass frit B as described in Example 5 was used instead of glass frit A, and 60 parts by weight of the powder and 40 parts by weight of the photosensitive organic component having the composition shown in Table 4 as texanol ( 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate) was prepared in the same manner as in Example 1 except that the photosensitive black paste composition of the present invention was prepared.

Component Usage (% by weight) Polymer: A polymer obtained by adding 10 mol% of glycidyl methacrylate to a copolymer composed of 60 mol% of n-butyl methacrylate, 10 mol% of 2-hydroxypropyl methacrylate and 30 mol% of methacrylic acid (molecular weight 50,000, T _g 50 ° C, acid value 100) 8 Monomer: Pentaerythritol tri / tetraacrylate 4 Photopolymerization initiator: Irgacure 369 of Tiba specialty chemicals 1.6

The photosensitive black paste obtained as described above was applied to a soda glass substrate having a size of 100 mm × 100 mm by screen printing to form a coating film. The thickness after drying a coating film at 90 degreeC for 30 minutes was 8 micrometers.

A negative pattern mask (stripe-shaped pattern, a line width of 80 μm, a pitch of 230 μm) was attached to the coating film and exposed to ultraviolet rays (a light source: an ultrahigh pressure mercury lamp) by irradiation (400 mJ / cm ² ). Subsequently, an aqueous solution of 0.5% sodium carbonate at 30 ° C. was sprayed and developed to remove the exposed portion. Thereafter, pure water was sprayed to wash the developer, and then dried at 80 ° C. for 20 minutes. Subsequently, it heated up at the speed | rate of 200 degreeC / hour, hold | maintained at the maximum temperature of 540 degreeC for 30 minutes, and baked.

The obtained black film was a rectangular film having a thickness of 3.3 mu m and a brightness index L of 17, and was firmly adhered to the substrate without end peeling or edge curl.

Example 8

A photosensitive black paste was prepared in the same manner as in Example 7, and 35 parts by weight of the same photosensitive component as described in Example 7, an average particle size of 1.8 mu m, a specific surface area of 2.4 m ² / g, and a density of 3.6 g / cm ³ were used. 65 weight part of Ag spherical powder was added to 3-methoxybutyl acetate as an organic solvent, and it melt | dissolved and knead | mixed with the triaxial roller to produce the photosensitive electrically conductive paste.

The photosensitive black paste was applied to a soda glass substrate having a size of 100 mm × 100 mm by screen printing, and dried at 90 ° C. for 20 minutes to form a coating film A having a thickness of 3.5 μm. The photosensitive conductive paste was applied on the coating film A in the same manner to form a coating film B having a dry thickness of 4.0 μm.

A negative pattern mask (stripe-shaped pattern, a line width of 80 μm, a pitch of 230 μm) was attached to the coating film B and exposed to ultraviolet light (a light source: an ultrahigh pressure mercury lamp) by irradiation (600 mJ / cm ² ). Subsequently, an aqueous solution of 0.5% sodium carbonate at 30 ° C. was sprayed and developed to remove the exposed portion. Thereafter, pure water was sprayed to wash the developer, and then dried at 80 ° C. for 20 minutes. Subsequently, it heated up at the speed | rate of 200 degreeC / hour, hold | maintained at the maximum temperature of 540 degreeC for 30 minutes, and baked.

The electrode thus obtained had a thickness of black bottom portion of 2.5 mu m, a thickness of white top portion of 2.3 mu m, and a thickness of the whole electrode of 4.8 mu m. In addition, the cross section of the two-layer film was almost rectangular, and was firmly adhered to the glass substrate without end peeling. The lower black film was black with a brightness index of 15, and no yellowing by silver was observed on the glass substrate.

The black paste according to the present invention contains a ruthenium multioxide fine powder and a glass frit, which can be fired even at a relatively low temperature, and can provide a thin film pattern having high adhesion strength to a substrate, low resistance and high blackness.

Claims (10)

15 to 25 parts by weight of ruthenium-based polyoxide fine powders with a specific surface area of 5 to 40 m ² / g, 40 to 85 parts by weight of glass frit with an average particle diameter of 0.2 to 2 μm and a maximum size of 5 μm or less and cellulose derivatives And 8 to 40 parts by weight of an organic vehicle selected from the group consisting of acrylic acid ester, methacrylic acid ester, polyvinyl alcohol and polyvinyl butyral. The method of claim 1, Ruthenium-based polyoxide powders include RuO ₂ , GdBiRu ₂ O ₇ , Pb ₂ Ru ₂ O ₆ , Co ₂ Ru ₂ O ₆ , PbBiRu ₂ O _6.5 , Cu _x Bi _2-x Ru ₂ O ₇ (x = 0-1) And Bi ₂ Ru ₂ O ₇ A composition comprising one or more selected from the group consisting of. The method of claim 1, Ruthenium-based fine oxide powder is characterized in that the average particle diameter ranges from 0.01 to 0.1 ㎛. The method of claim 1, When the glass frit is expressed in terms of oxide, 40 to 90 parts by weight of Bi ₂ O ₃ , 5 to 30 parts by weight of SiO _2, 5 to 30 parts by weight of B ₂ O ₃ , and BaO 2 to 40 parts by weight, Composition. The method of claim 1, When the glass frit is expressed in terms of oxide, 40 to 90 parts by weight of PbO, 10 to 40 parts by weight of SiO ₂ , 5 to 30 parts by weight of B ₂ O ₃ , 0 to 10 parts by weight of ZnO and 0 to 20 parts of Al ₂ O ₃ A composition comprising a weight part. The method of claim 1, When the glass frit is expressed in terms of oxide, 40 to 90 parts by weight of Bi ₂ O _3, 40 to 90 parts by weight of PbO, 5 to 30 parts by weight of SiO _2, 5 to 30 parts by weight of B ₂ O ₃ , and ZnO 0 to 10 Composition by weight and Al ₂ O ₃ 0 to 20 parts by weight. The method of claim 1, And further comprising an electrically conductive powder in an amount ranging from 5 to 30% by weight relative to the total amount of the ruthenium multioxide fine powder, glass frit and organic vehicle. The method of claim 1, The conductive powder is a composition characterized in that at least one selected from the group consisting of Ag, Au, Pd, Ni and Pt. The method of claim 1, The composition characterized in that the conductive powder has an average particle diameter in the range of 0.8 to 4 μm. The method of claim 1, A composition comprising a photosensitive resin and a photopolymerization initiator.