JP2002270037A - Photo-curing type conductor ink and method for forming electrode pattern - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide ultraviolet-curable conductor ink and an electrode forming method capable of forming a high-precision electrode pattern by a lithographic offset printing method. SOLUTION: This ultraviolet-curable conductor ink comprises at least conductive powder and an organic constituent removable by baking, and contains 50-90 wt.% of the conductive powder and 10-50 wt.% of the organic constituent removable by baking. The organic constituent is a photo-curing resin prepared by imparting a photo-reactive functional group to a copolymer comprising at least (metha)allyl ether expressed by the following general formula (1): H2 C= CR1 HCH2 O(AO)n R, and maleic acid anhydride as monomer materials and having two or more constituent units derived from the monomers. In the formula, R1 is H or CH3 , AO is a mixture of one or more kinds of 3-18C oxyalkylene groups, which may be added in a block-like form in the case of two or more kinds, R is a 4-24C hydrocarbon group or an acyl group, and (n) is a number of 1-1000 representing the mean additional mol number of the oxyalkylene group.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive ink for forming an electrode pattern with high precision by lithographic offset printing, and a method of forming an electrode. The present invention relates to a conductive ink suitable for forming an electrode for an image display device, an image pickup tube electrode, and particularly an electrode for a plasma display, which requires high accuracy, and to an electrode forming method.

[0002]

2. Description of the Related Art In recent years, it has been demanded that a fine pattern of electrodes in an electronic circuit or an image display device can be formed with higher accuracy and at lower manufacturing cost.

Conventionally, as a method for forming a fine electrode pattern, a pattern is formed by a screen printing method or a photolithographic method using a pattern forming paste containing a conductive powder, and then the organic component is volatilized by firing. There is a method of making the electrode pattern. However, in the electrode pattern formation by the screen printing method, there is a limit of printing accuracy due to elongation of a mesh material constituting a screen printing plate, and the problem that edge accuracy of the formed pattern is low and that the screen is easily clogged. Therefore, there is a problem that it is not suitable for continuous mass production. On the other hand, the photolithography method, although capable of forming an electrode pattern with high accuracy, has a complicated manufacturing process, a large amount of material loss, and has a limit in reducing the manufacturing cost.

[0004] For this reason, it has been attempted to reduce the cost of forming a fine electrode pattern by using a lithographic offset printing method having a simple process and mass productivity. In this lithographic offset printing method, a conductive ink containing a conductive powder is supplied to an intaglio or lithographic printing plate, and the ink pattern on the printing plate is once transferred to a blanket, and then transferred to an electrode forming object. After that, it is fired to decompose organic components,
The electrode pattern is formed by volatilization.

[0005] The lithographic offset printing method described above has an advantage that it is possible to form an electrode pattern with higher precision than the screen printing method, and that the amount of ink used is smaller than that of the photolithographic method. Further, in the photolithography method, the cross-sectional shape in the width direction of the electrode pattern formed by firing has a sharp edge, and a dielectric layer is formed thereon, for example, like an electrode of a plasma display panel. In such a case, there is a problem that the edge of the electrode breaks through the dielectric layer and is exposed,
The electrode obtained by the lithographic offset printing method has an advantage that the problem can be solved because the edge is smooth (not sharp).

[0006]

However, in the conventional lithographic offset printing method using a conductive ink, there is a problem that the ink supply to the image portion of the waterless lithographic plate is insufficient or the background is stained. . Further, there are problems that the width accuracy of the formed print pattern is poor, that a sufficient film thickness cannot be obtained after printing, and that a pinhole is generated.

Also, a metal intaglio or a glass intaglio,
In the lithographic offset printing method using a blanket, a doctor blade is generally used for filling the conductive ink into the intaglio plate, but this doctor blade has problems such as durability.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned circumstances, and provides a photocurable conductive ink capable of forming a highly accurate electrode pattern by a lithographic offset printing method. An object of the present invention is to provide an electrode forming method using a curable conductive ink.

[0009]

The above object is achieved by the present invention described below. The photocurable conductive ink of the present invention,
A photocurable conductive ink containing 50 to 90% by weight of a conductive powder and 10 to 50% by weight of an organic component, wherein the organic component is represented by the following general formula (1). Allyl ether and maleic anhydride are used as at least a monomer raw material, and other monomers are blended if necessary, and a copolymer having at least two or more structural units derived from the monomer is used as a photoreactive functional group. A photocurable resin ink, which is a photocurable resin obtained by imparting the following.

[0010]

Embedded image

(Wherein, R ₁ represents H or CH ₃ , AO is one or a mixture of two or more oxyalkylene groups having ₃ to 18 carbon atoms, and when two or more are added, they are added in a block form.) R may represent a hydrocarbon group or an acyl group having 4 to 24 carbon atoms, and n may be 1 to 1000 in terms of the average number of moles of the oxyalkylene group added.) In the organic component,
As the copolymer before providing the photoreactive functional group, a copolymer represented by the following general formula (2) can be used.

[0012]

Embedded image

(Wherein, in the formula, n is 20 to 70, and AO is one or a mixture of two or more oxyalkylene groups having 3 to 18 carbon atoms.) R is a hydrocarbon group or an acyl group having 4 to 24 carbon atoms, and m is an average number of added moles of an oxyalkylene group of 1 to 1
000 and X represent a linear or branched alkylene group, and Y represents a hydrogen atom or a methyl group, respectively. The photocurable conductive ink of the present invention having the above-described configuration improves the dispersibility of the conductive powder, and makes it possible to control the viscosity of the ink to a desired value. It is presumed that such an improvement in the dispersibility of the conductive powder is due to the formation of a metal complex by coordination of a conductive atom, for example, Ag, using the carbonyl group in the copolymer resin as a ligand. Therefore, even when applied to lithographic offset printing, thick coating is possible, and a highly reliable and accurate electrode pattern can be formed. In addition, the photocurable conductive ink of the present invention is further subjected to lithographic offset printing on the once cured lithographic offset printing coating film in order to cure with ionizing radiation (ie, ultraviolet rays or electron beams). By doing so, it is possible to freely control the film thickness to a desired value. Therefore, if the electrode pattern is formed by lithographic offset printing using the photocurable conductive ink of the present invention, in addition to the excellent pattern accuracy inherent in lithographic offset printing, there is an advantage that thick coating is possible. is there.

The photocurable conductive ink of the present invention can contain glass frit in a range not exceeding 10% by weight. When the electrode pattern formation body is a glass substrate, the adhesion between the fired electrode and the glass substrate is improved. When the content of the glass frit exceeds 10% by weight, the storage stability of the conductive ink deteriorates, the resistance value of the electrode increases, and the edge shape deteriorates.

The method for forming an electrode according to the present invention comprises the steps of: printing a photocurable conductive ink containing a conductive powder in a pattern by printing;
For example, it is characterized in that a printing pattern is formed by applying the composition to a substrate surface such as glass and exposing it to light. For the printing in the electrode forming method of the present invention, planographic offset printing and rotary printing can be suitably applied.

The photocurable conductive ink of the present invention is applied by lithographic offset printing or rotary printing to, for example, a substrate surface such as glass in a pattern and is exposed to cure the resin component to form a printed pattern. In addition, it is possible to form a highly accurate electrode pattern of an image display device such as a plasma display panel.

In the lithographic offset printing method employed in the electrode forming method of the present invention, the intaglio is filled with ink by a roll, and the printing pattern formed by the intaglio is transferred to a lithographic blanket. This is performed by a technique of transferring to a coating. When the intaglio is a glass intaglio, a doctor may be used to fill the intaglio with ink.

The photocurable conductive ink of the present invention is particularly suitable for such lithographic offset printing. If the photocurable conductive ink of the present invention is printed by lithographic offset printing, the thickness of the printed coating film can be adjusted. It is possible to perform thick printing. The thickness of the printed coating film obtained by the electrode forming method of the present invention can be thickened to a thickness of 10 μm or less after firing in one lithographic offset printing. Since the lithographic offset printing of the present invention can cure the resin component by exposing the printed coating film applied in a pattern form, after one application, immediately apply the same lithographic offset printing to perform overcoating, and finally, A firing step can be performed, and in a short time, an electrode pattern having an increased thickness can be continuously formed. For example, the thickness at the time of printing for forming an electrode of an image display device such as a plasma display panel can be formed. (Printed coating film before firing) can be 16 μm or more.

The pattern such as lithographic offset printing or rotary printing using the photocurable conductive ink of the present invention can be formed into an electrode pattern whose density is enhanced by firing and whose conductivity is enhanced. For those requiring high conductivity, such as electrodes for plasma displays, it is desirable to perform a firing step. In the photocurable conductive ink of the present invention, the firing is performed by raising the temperature from room temperature to 400 ° C to 600 ° C.

[0020]

Next, the present invention will be described in more detail with reference to preferred embodiments.

Conductive Powder As the conductive powder used in the photocurable conductive ink of the present invention, Au, Ag, Cu, Al, Pt, Pd, Ni and the like can be mentioned. One or two of
More than one kind, and further, alloy powders of the above metals can be used. The shape of the conductive powder may be any of various shapes such as an irregular shape, a lump, a scale, a microcrystal, a sphere, and a flake.

The photocurable conductive ink of the present invention preferably contains two or more types of conductive powders having different particle diameters. By including two or more kinds of conductive powders selected from the group having different particle diameters in the ink, the thixotropic property of the ink is increased and the viscosity of the ink can be adjusted to be higher. For this reason, there is an effect that background stains do not occur in the print pattern. The conductive powder has an average particle size of 0.02 to 5 μm, preferably 0.1 to 2.0 μm.
To 90% by weight, preferably 60 to 90% by weight, and an average particle size of 1 to 10 μm, preferably 3 to 8 μm. A ratio of 40% by weight is preferable for adjusting the viscosity of the ink.

If the average particle size of the conductive powder is less than 0.02, the conductive powder in the conductive ink tends to agglomerate, making dispersion difficult. On the other hand, if the average particle size exceeds 10 μm, when kneading the ink with an inking roll of a lithographic offset printing machine, separation occurs, or the transfer state becomes poor when transferring the ink between rolls, or the plate is damaged. There is a possibility that it is not preferable.

When the content of the conductive powder in the photo-curable conductive ink of the present invention is less than 50% by weight, the organic component removed by firing increases, the denseness of the electrode becomes poor, and the resistance decreases. The value may be high or, in some cases, a disconnection may occur. When the content of the conductive powder exceeds 90% by weight, the shape retention of the printed film of the conductive ink is low,
It becomes difficult to form a good pattern. When the content of the organic component in the photocurable conductive ink of the present invention is less than 10% by weight, the shape retention of the printed coating film of the conductive ink is low, and it is difficult to form a good pattern, and the content exceeds 50% by weight. In addition, the amount of organic components removed by firing increases, and the denseness of the electrode deteriorates, the resistance value increases, and in some cases, disconnection occurs, which is not preferable.

The shape of the conductive powder is such that the conductive powder having an average particle size of 0.02 to 5 μm is spherical or microcrystalline, and the conductive powder having an average particle size of 1 to 10 μm is scale-like. It is preferable that the ink be in the form of a flake or a flake in order to adjust the viscosity of the ink.

The viscosity of the photocurable conductive ink of the present invention at a rotation speed of 100 s ^-1 is desirably in the range of 1,000 to 5,000 P, preferably 1500 to 3,500 P. By setting the range as described above, it becomes possible to prevent background contamination in planographic offset printing and to stabilize the shape of a printed pattern. The viscosity was measured by RDA-II manufactured by Rheometric Scientific Inc.
The viscosity was measured when the ink was sandwiched between parallel plates of 25 mmφ and a shear was applied.

Since the photocurable conductive ink of the present invention is cured by ultraviolet rays or electron beams, the film thickness can be freely controlled by overprinting. For example, after printing and before firing, a thickness of 16 μm or more can be achieved, and the photocurable conductive ink of the present invention can have such a film thickness even when lithographic offset printing is used. In addition,
After firing, the organic components are removed by firing, so that the final thickness of the electrode for an image display device such as an electrode for a plasma display can be made 10 μm or less.

In lithographic offset printing, the formed printing film surface may not be stable in a single printing step, but the photocurable conductive ink of the present invention can be used for continuous printing of two or more times. Therefore, by performing lithographic offset printing twice or more, the film surface is stabilized, and the print pattern shape is stabilized.

Organic Component The organic component constituting the photocurable conductive ink of the present invention is the above-mentioned copolymer, which is volatilized and decomposed by firing to leave carbide in the fired film. Anything that does not have anything. Allyl ether represented by the general formula (1), maleic anhydride, and, if necessary, a monomer copolymerizable with these monomers, for example, a vinyl-type monomer, more specifically, styrene, etc. A compound obtained by adding an aromatic vinyl compound or the like as a copolymer component can be used as an organic component. In order to make the copolymer a photocurable resin, the maleic anhydride site is opened and reacted with a reactive monomer having a hydroxyl group in the structure to obtain a photocurable resin. As the reactive monomer used,
It is sufficient that the structure contains a hydroxyl group. Examples of the reactive monomer that can be used include 2-hydroxyethyl (meth) acrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, and caprolactone-modified 2-hydroxyethyl acrylate. , Caprolactone-modified 2-hydroxyethyl methacrylate, 2
-Hydroxypropyl acrylate, 2-hydroxypropyl methacrylate and the like.

The photocurable conductive ink of the present invention contains, as additives, a dispersant, a wetting agent, a thickener, a leveling agent, an antifouling agent, a gelling agent, a silicone oil, a silicone resin, and an antifoaming agent. And a plasticizer may be added.

The photocurable conductive ink of the present invention may optionally contain a polymerization initiator, a polymerization inhibitor, a reactive monomer and the like. As a polymerization initiator to be added to the photocurable conductive ink of the present invention, it does not volatilize and decompose by firing and does not leave carbides in the film after firing. Specifically, benzophenone, methyl 0-benzoylbenzoate, 4,4-bis (dimethylamine) benzophenone,
4-4 bis (diethylamine) benzophenone, α-amino acetophenone, 4,4-dichlorobenzophenone, 4-benzoyl-4-methyldiphenylketone, dibenzylketone, fluorenone, 2,2-diethoxyacetophenone, 2,2- Dimethoxy-2-phenylacetophenone, 2-hydroxy-2-methylpropylphenone, p-tert-butyldichloroacetophenone,
Thioxanthone, 2-methylthioxanthone, 2-chlorothioxanthone, 2-isopropylthioxanthone,
Diethylthioxanthone, benzyldimethyl ketal,
Benzylmethoxyethyl acetal, benzoin methyl ether, anthraquinone, 2-tert-butylanthraquinone, 2-amylanthraquinone, β-chloranthraquinone, anthrone, benzanthrone, dibensuberone, methyleneanthrone, 4-azidobenzylacetophenone, 2,6-bis ( p-azidobenzylidene) -4-methylcyclohexanone, 2-phenyl-
1,2-butadione-2- (0-methoxycarbonyl)
Oxime, 1-phenyl-propanedione-2- (0-
Ethoxycarbonyl) oxime, 1,3-diphenyl-
Propanetrione-2- (0-ethoxycarbonyl) oxime, 1-phenyl-3-ethoxypropanetrione-2- (0-benzoyl) oxime, Michler's ketone, 2-methyl- [4- (methylthio) phenyl] -2
-Morpholino-1-propane, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1, naphthalenesulfonyl chloride, quinoline sulfonyl chloride, n-phenylthioacridone, 4,4-azo Photoreducible dyes such as bisisobutyronitrile, diphenyl sulfide, benzthiazole disulfide, triphenylphosphine, camphorquinone, carbon tetrabromide, tribromophenyl sulfone, benzoin peroxide, eosine, methylene blue, and ascorbic acid, Examples thereof include a combination of reducing agents such as ethanolamine, and these can be used alone or in combination of two or more.

In addition, a reactive monomer may be added to the photocurable conductive ink of the present invention, if necessary. The reactive monomer to be added is one which does not volatilize or decompose by firing and does not leave carbide in the film after firing, and may include polyfunctional and monofunctional reactive monomers. For example, monofunctional tetrahydrofurfuryl (meth) acrylate, hydroxyethyl (meth)
Mono (meth) acrylates such as acrylate, vinylpyrrolidone, (meth) acryloyloxyethyl succinate, (meth) acryloyloxyethyl phthalate;
If it is bifunctional or more, when classified by skeleton structure, polyol (meth) acrylate (epoxy-modified polyol (meth) acrylate, lactone-modified polyol (meth) acrylate, etc.), polyester (meth) acrylate, epoxy (meth) acrylate, urethane (meth) Acrylates: Other poly (meth) acrylates having a skeleton of polybutadiene, isocyanuric acid, hydantoin, melamine, phosphoric acid, imide, phosphazene, etc., and are various types of UV curable and electron beam curable Various monomers, oligomers and polymers can be used.

More specifically, a bifunctional monomer,
Oligomers and polymers such as polyethylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, and 1,6-hexanediol di (meth) acrylate; trifunctional monomers and oligomers;
The polymer is trimethylolpropane tri (meth)
Acrylate, pentaerythritol tri (meth) acrylate, aliphatic tri (meth) acrylate, etc .; tetrafunctional monomers, oligomers and polymers as pentaerythritol tetra (meth) acrylate, ditrimethylolpropanetetra (meth) acrylate, aliphatic tetra ( Meth) acrylates and the like; pentafunctional or higher functional monomers, oligomers and polymers having dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, etc., as well as a polyester skeleton, urethane skeleton, and phosphazene skeleton. (Meth) acrylate and the like. The number of functional groups is not particularly limited, but if the number of functional groups is less than 3, the curability tends to decrease. If the number of functional groups is 20 or more, carbide tends to remain in the film after firing. ~ 2
Those having zero functionality are preferred. In the present invention, the above monomer is
It can be used as a species or a mixture of two or more.

Glass frit The glass frit to be contained in the conductive ink of the present invention as required is, for example, a softening temperature of 400 to 600 ° C.
And the thermal expansion coefficient α ₃₀₀ is 35 × 10 ^{−7 to} 85 × 10 ^−7.
/ ° C, a glass frit having a glass transition temperature of 300 to 500 ° C can be used, and ZnO-based glass, B ₂
It is desirable to use a glass frit that does not contain an alkali oxide such as an O ₃ -alkaline earth metal oxide glass. If the softening temperature of the glass frit exceeds 600 ° C., it is necessary to increase the firing temperature. For example, when the heat resistance of the electrode pattern forming body is low, thermal deformation occurs in the firing step, which is not preferable. On the other hand, if the softening temperature of the glass frit is less than 400 ° C., the glass frit is fused before the organic components are completely decomposed and volatilized and removed by baking, which is not preferable because voids are easily formed. further,
Thermal expansion coefficient alpha ₃₀₀ of the glass frit is 35 × 10 ^-7 / ℃
If it is less than 85 × 10 ⁻⁷ / ° C., the difference from the coefficient of thermal expansion of the electrode pattern-formed body may be too large, which may cause distortion and the like, which is not preferable. The particle size (D ₅₀ ) of such a glass frit is in the range of 0.1 to 5 μm, preferably 0.5 to 3 μm.

Solvent The photocurable conductive ink of the present invention can be solvent-free depending on the type of monomer. However, when a solvent is added to the photocurable conductive ink of the present invention and used, a solvent having a boiling point of 390 ° C. or lower is used. Solvents that are easily absorbed by the blanket change the properties of the conductive ink, and are undesirable because the blanket swells and reduces the printing dimensional accuracy. The solvent to be used is preferably a petroleum solvent such as normal paraffin, isoparaffin, naphthene, or alkylbenzene, or a mixed solvent obtained by combining these. When a mixed solvent is used, it is desirable to select a background stain in consideration of printability such as resistance.

The photocurable conductive ink of the present invention has an extremely good dispersibility despite the high content of the conductive powder, and is excellent in kneading on an inking roll and applicability to a lithographic plate. Things. In the lithographic offset printing using the photocurable conductive ink of the present invention, the thickness of the printed pattern can be increased, and the electrode pattern can be formed with higher precision by firing the electrode pattern.

When performing lithographic offset printing using the photocurable conductive ink of the present invention, there is no particular limitation on the lithographic offset printing machine to be used. FIG. 1 is a plan view showing a preferred example of the lithographic offset printing press, and FIG. 2 is a side view of the lithographic offset printing press shown in FIG. 1 and 2, a lithographic offset printing press 1 includes a base 2 on which a printing platen 3 and a printing plate 4 are arranged at a predetermined interval, and two guide rails 5, 5 are laid in parallel. A print head 6 which can be freely moved on the guide rails 5 by a moving mechanism (not shown).

The print head 6 is provided with a blanket roll 7 that can be raised and lowered and a first inking roll group 8. The first inking roll group 8 includes a kneading roller that swings in the direction of the rotation axis of the roll, and an inking roll that applies ink to a printing plate. The base 2 is provided with a second inking roll group 9 and an ink blade 10 for storing conductive ink. The second inking roll group 9 is composed of an ink ejection roll for ejecting ink from the ink blade 10 and a kneading roller that swings in the roll rotation axis direction.

The lithographic offset printing press shown in FIGS. 1 and 2 transfers an intaglio pattern onto a blanket and prints on a substrate with the blanket. In the lithographic offset printing press 1, an electrode pattern forming body 11 (FIG.
Is indicated on the printing platen 3). Then, the print head 6 first moves on the guide rails 5, 5 onto the second inking roll group 9. Here, the second
The conductive ink kneaded and uniformized in the inking roll group 9 of the first inking roll group 8 of the print head 6
Is transferred to Next, the print head 6 is mounted on the guide rail 5,
5 is moved toward the printing plate 4 and the conductive ink is applied to the printing plate 12 by the inking rolls of the first inking roll group 8. The printing plate 12 is an intaglio plate, so that the ink can be thicker than a lithographic plate. Thereafter, the print head 6 returns on the guide rails 5 and 5 to the second inking roll group 9 side, and again the conductive ink kneaded and uniformed by the second inking roll group 9 is printed. 6 and transferred to the first inking roll group 8.
During this time, the blanket roll 7 has risen to a position where it does not contact the printing plate 12. This ink application operation may be performed a plurality of times. Next, the print head 6 moves toward the printing platen 3 with the blanket roll 7 lowered to the printing position. Then, when the print head 6 passes through the printing plate 4, the conductive ink on the image portion of the printing plate 12 is transferred to the blanket roll 7, and at the same time, the printing is performed by the inking rolls of the first inking roll group 8. The conductive ink is newly applied to the printing plate 12.

The print head 6 further moves toward the printing platen 3, and the conductive ink is printed from the blanket roll 7 on the electrode pattern forming body 11 placed on the printing platen 3. Thereafter, the print head 6 returns to the second inking roll group 9 side.

When the print head 6 returns to the second inking roll group 9 side, the blanket roll 7 may be used to print on the electrode pattern forming body 11 in a superimposed manner. When the print head 6 returns to the second inking roll group 9 side while transferring the conductive ink from the printing plate 12 to the blanket roll 7, the print head 6 moves toward the printing platen 3 again. And blanket roll 7
The conductive ink may be overlaid on and transferred. By doing so, the electrode pattern can be printed thick.
Further, generation of holes can be prevented. In addition, when transferring the ink by overlapping, it is possible to eliminate the tack on the surface by exposing with an ultraviolet ray or an electron beam, and to transfer the ink by overlapping. This makes it possible to perform thick printing with high accuracy.

The electrode pattern obtained by the lithographic offset printing in this way is fired, if necessary, to substantially remove organic components, thereby enhancing the conductivity of the electrode pattern. For baking, heating is performed in the range of 400 ° C to 600 ° C. To substantially remove the organic component in the present invention,
Organic components in the final printed coating are less than 10%, preferably 0%
%. When the photocurable conductive ink of the present invention is used for an electrode pattern for a plasma display, the electrode pattern after firing has an organic component of 0% without limit.
However, this is not always the case, particularly when used in applications where resistance is not considered.

The photocurable conductive ink of the present invention is suitable for forming electrodes for plasma displays, but is not limited thereto. Electrodes for image displays such as electrodes for EL displays, electrodes for LCD displays, and CRT electrodes. It can be applied to the formation of an imaging tube electrode. The electrode that does not require a glass frit can be applied to an electrode for a film liquid crystal display, an electrode for a film EL display, and an electrode for a film color film.

[0044]

EXAMPLES Examples of the production of the photocurable resin used in this example are shown below.

Production Example 1 of Photocurable Resin A 2-liter four-necked flask equipped with a reflux condenser, a stirrer, a dropping funnel and a thermometer was charged with an allyl ether-maleic anhydride copolymer, Marialim AAB-0851 (product). 200 g of Nippon Oil and Fat and 7.0 g of 2-hydroxyethyl methacrylate (abbreviation: HEMA) were charged together with an acidic catalyst, reacted at a temperature of 90 to 100 ° C. for 12 hours, and then cooled to room temperature. By IR analysis of the product, 17
The disappearance of the absorption peak at 80 cm ^-1 was confirmed, and the reaction was terminated. As the conductive powder, silver powder A having the properties shown in Table 1 below,
B, C, and D were prepared.

[0046]

[Table 1]

Preparation of Photocurable Conductive Ink One of the above conductive powders (A to D) was used, and the components shown in Examples 1 to 5 below were mixed to prepare five types of Examples 1 to 5. A photocurable conductive ink was prepared. The amounts of the conductive powder, the total amount of the organic components, and the amount of the glass frit used in the conductive ink are shown in Examples 1 to 5 below.

Example 1 60 parts by weight of conductive powder A 15 parts by weight of conductive powder B 3 parts by weight of glass frit (ASF 1350: trade name, manufactured by Asahi Glass Co., Ltd.) 10 parts by weight of resin of Production Example 1 Pentaerythritol hexaacrylate (KAYARAD DPHA: trade name, manufactured by Nippon Kayaku Co., Ltd.) 5 parts by weight Trimethylolpropane triacrylate (KAYARAD TMPTA: trade name, manufactured by Nippon Kayaku Co., Ltd.) 5 parts by weight Photopolymerization initiator (Irg. 184: Product name, Ciba Specialty Chemicals) 2 parts by weight

Example 2 17 parts by weight of conductive powder B 60 parts by weight of conductive powder C 1.5 parts by weight of glass frit (ASF 1350: trade name, manufactured by Asahi Glass Co., Ltd.) Glass frit (ASF 1375: product) 1.5 parts by weight Resin of Production Example 1 10 parts by weight Dipentaerythritol hexaacrylate (KAYARAD DPHA: trade name, manufactured by Nippon Kayaku Co., Ltd.) 8 parts by weight Photopolymerization initiator (Irg. 184: Product name, Ciba Specialty Chemicals) 2 parts by weight

Example 3 Conductive Powder A 60 parts by weight Conductive Powder B 20 parts by weight Glass frit (ASF 1350: trade name, manufactured by Asahi Glass Co., Ltd.) 1.5 parts by weight Glass frit (ASF 1375: product Name, manufactured by Asahi Glass Co., Ltd.) 1.5 parts by weight 15 parts by weight of resin of Production Example 1 photopolymerization initiator (Irg. 184: trade name, manufactured by Ciba Specialty Chemicals) 2 parts by weight solvent (AF6: trade name, day) 5 parts by weight

[Example 4] 65 parts by weight of conductive powder C 10 parts by weight of conductive powder D 5 parts by weight of glass frit (ASF 1280: trade name, manufactured by Asahi Glass Co., Ltd.) 15 parts by weight of resin of Production Example 1 Methylolpropane triacrylate (KAYARAD TMPTA: trade name, manufactured by Nippon Kayaku Co., Ltd.) 3 parts by weight Photopolymerization initiator (Irg.184: trade name, manufactured by Ciba Specialty Chemicals Co., Ltd.) 2 parts by weight

[Example 5] 10 parts by weight of conductive powder B 60 parts by weight of conductive powder D 5 parts by weight of glass frit (ASF 1375: trade name, manufactured by Asahi Glass Co., Ltd.) 15 parts by weight of resin of Production Example 1 Methylolpropane triacrylate (KAYARAD TMPTA: trade name, manufactured by Nippon Kayaku Co., Ltd.) 5 parts by weight Photopolymerization initiator (Irg.184: trade name, manufactured by Ciba Specialty Chemicals) 5 parts by weight Solvent (No. 5 solvent: trade name) , Made by Mitsubishi Nisseki) 5 parts by weight

Comparative Example 1 Conductive Powder A 80 parts by weight Glass frit (ASF 1350: trade name, manufactured by Asahi Glass Co., Ltd.) 3 parts by weight Trimethylolpropane triacrylate (KAYARAD TMPTA: trade name, manufactured by Nippon Kayaku Co., Ltd.) 7 parts by weight Diallyl phthalate (Dups: trade name, manufactured by Daiso Co., Ltd.) 8 parts by weight Photopolymerization initiator (Irg.184: trade name, manufactured by Ciba Specialty Chemicals) 2 parts by weight

Comparative Example 2 80 parts by weight of conductive powder B Glass frit (ASF 1280: trade name, manufactured by Asahi Glass Co., Ltd.) 3 parts by weight dipentaerythritol hexaacrylate (KAYARAD DPHA: trade name, manufactured by Nippon Kayaku Co., Ltd.) 7 parts by weight Diallyl phthalate (Dups: trade name, manufactured by Daiso Co., Ltd.) 8 parts by weight Photopolymerization initiator (Irg.184: trade name, manufactured by Ciba Specialty Chemicals) 2 parts by weight

Comparative Example 3 Conductive Powder A 15 parts by weight Conductive Powder B 60 parts by weight Glass frit (ASF 1350: trade name, manufactured by Asahi Glass Co., Ltd.) 1.5 parts by weight Glass frit (ASF 1375: product Name, manufactured by Asahi Glass Co., Ltd.) 1.5 parts by weight 20 parts by weight of resin of Production Example 1 photopolymerization initiator (Irg. 184: trade name, manufactured by Ciba Specialty Chemicals) 2 parts by weight solvent (AF6: trade name, day) 5 parts by weight

Example 6 Formation of Electrode Pattern Using the conductive inks of Examples 1 to 5 and Comparative Examples 1 to 3 prepared in the above steps, a lithographic offset printing machine shown in FIG. Glass substrate (soda glass, 350mm)
× 450 mm, pressure 2.1 mm) under the following printing conditions, and then the temperature was raised to 580 ° C. in a firing apparatus manufactured by Koyo Thermo System Co., Ltd.
The electrode pattern was obtained by holding for 0 minutes and lowering to room temperature. Printing conditions Printing speed: 600 mm / s Printing pressure: 0.1 mm (both on the printing plate and on the substrate) Number of printings: 4 Printing plates used: Waterless plate (DG-
2) (100 μm width of image area) Blanket roll: NBR blanket The printing adequacy of the conductive ink in the above-described electrode pattern formation, the shape of the printed material, and the quality of the electrode pattern were evaluated. The results are shown in Table 2 below.

[0057]

[Table 2]

According to Table 2, the photocurable conductive inks of Examples 1 to 5 of the present invention were compared in both the dispersibility of the conductive powder, the printing characteristics of the photocurable conductive ink, and the formed electrode pattern. It turns out that it is better than the example.

Example 7 Measurement of Viscosity The viscosity of the photocurable conductive ink used in Example 3 and Comparative Example 3 was measured using RDA-II (trade name, manufactured by Rheometric Scientific). , Rate
The viscosity was measured when the ink was sandwiched between a 25 mmφ parallel plate and a shear by a sweep. The results are shown in the graph of the viscosity chart of FIG. In FIG. 3, the arrow A indicates the viscosity curve of the ink of Example 3, and the arrow B indicates the viscosity curve of the ink of Comparative Example 3. It can be seen that the particle size distribution of the conductive powder is not within the scope of the present invention, and the viscosity is very high when the weight ratio of the two types of conductive powder used in Example 3 is reversed. .

Thermogravimetric Analysis TGA (thermogravimetric analysis) of a coating film obtained by irradiating 500 mJ / cm ² of ultraviolet rays using the resin composition obtained by removing the conductive powder from the ink composition of Example 3 was measured. . For comparison, a coating film obtained by curing only the organic component excluding the conductive powder of Comparative Example 2 was performed. For thermogravimetric analysis,
The measurement was performed by a method based on JIS-K7120. TGA-7 (trade name, manufactured by Perkin Elmer) as a thermogravimetric analyzer
And at a heating rate of 20 ° C./min. as a result,
The obtained TGA (thermogravimetric analysis) is shown as a graph in FIG. 4 (Example 3) and FIG. 5 (Comparative Example 2). 4 and 5, it can be seen that the resin of Example 3 has better firing properties than the resin of Comparative Example 2.

Example 8 Using a photocurable conductive ink having the same composition as in Example 3 above, overprinting was performed once to four times by a lithographic offset printing machine shown in FIGS. Every time printing is performed, a UV irradiation device (FUSION UV SYS
500 mJ using an H valve with TEM
/ Cm ² was applied. The results of the film thickness at each time were as follows. In addition, the first time indicates the number of times of the transition from blanket roll to glass in lithographic offset printing. First time 3.24 μM Second time 8.7 μM Third time 12.5 μM Fourth time 16.7 μM

[0062]

According to the photocurable conductive ink of the present invention,
16 μm by printing method, especially lithographic offset printing method
The above-described thick printing can be performed, the background stain can be prevented, and an electrode pattern can be formed with higher precision than screen printing.

The photocurable conductive ink of the present invention has good dispersibility of the conductive powder, printability, electrode patternability, and firing property.

The printing pattern using the photocurable conductive ink of the present invention can be made into an electrode pattern whose compactness is enhanced by firing and whose conductivity is enhanced.

[Brief description of the drawings]

FIG. 1 is a plan view showing an example of a lithographic offset printing press for forming an electrode pattern using the photocurable conductive ink of the present invention.

FIG. 2 is a side view of the lithographic offset printing press shown in FIG.

FIG. 3 is a graph showing a viscosity measurement of the photocurable conductive ink used in Example 3 and Comparative Example 3.

FIG. 4 is a graph showing the results of thermogravimetric analysis of the resin used in the ink of Example 3.

FIG. 5 is a graph showing the results of thermogravimetric analysis of the resin used in the ink of Comparative Example 2.

[Explanation of symbols]

 Reference Signs List 1 lithographic offset printing machine 2 base 3 printing platen 4 printing plate 5 guide rail 6 print head 7 blanket roll 8 first inking roll group 9 second inking roll group 10 ink blade 11 electrode pattern forming body 12 Printing plate

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] March 29, 2001 (2001.3.2)
9)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0056

[Correction method] Change

[Correction contents]

Example 6 Formation of Electrode Pattern Using the conductive inks of Examples 1 to 5 and Comparative Examples 1 and 2 prepared in the above steps, a lithographic offset printing machine shown in FIG. Glass substrate (soda glass, 350mm)
× 450 mm, thickness 2.1 mm) under the following printing conditions, and then the temperature was raised to 580 ° C. in a firing device manufactured by Koyo Thermo System Co., Ltd.
The electrode pattern was obtained by holding for 0 minutes and lowering to room temperature. Printing conditions Printing speed: 600 mm / s Printing pressure: 0.1 mm (both on the printing plate and on the substrate) Number of printings: 4 Printing plates used: Waterless plate (DG-
2) (width of image area 100 microns m) blanket roll: NBR blanket conductive ink in the above-mentioned electrode pattern forming printability, to assess the quality of the electrodes pattern, and the results are shown in Table 2 below.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01J 11/02 H01J 11/02 BF Term (Reference) 4J039 AD01 AD02 AD10 AD14 BA06 BA25 BD02 BD04 BE12 EA24 FA04 GA02 5C027 AA02 5C040 GC03 GC18 GC19 JA12 JA21 JA28 KA01 KA16 KB03 KB09 KB17 KB28 MA24 MA26 5G301 DA03 DA34 DA38 DA42 DD02 5G323 CA05

Claims (17)

[Claims] 1. An electroconductive powder comprising at least a conductive powder and an organic component capable of being calcined and removed. Wherein the organic component comprises (meth) allyl ether represented by the following general formula (1) and maleic anhydride as at least a monomer material, and is derived from the monomer. A photocurable conductive ink, which is a photocurable resin obtained by adding a photoreactive functional group to a copolymer having at least two units. Embedded image (However, in the formula, R ₁ represents H or CH ₃ , and AO is one or a mixture of two or more oxyalkylene groups having ₃ to 18 carbon atoms. R may represent a hydrocarbon group or an acyl group having 4 to 24 carbon atoms, and n represents an average number of added moles of the oxyalkylene group of 1 to 1000.) 2. The photocurable conductive ink according to claim 1, wherein the copolymer before imparting the photoreactive functional group is represented by the following general formula (2). Embedded image (However, in the formula, n is 20 to 70, and AO has 3 to 1 carbon atoms.
8 or a mixture of two or more oxyalkylene groups, and when two or more oxyalkylene groups are used, they may be added in a block form; R is a hydrocarbon group or an acyl group having 4 to 24 carbon atoms; X represents a linear or branched alkylene group; Y represents a hydrogen atom or a methyl group; ) 3. The photocurable conductive ink according to claim 1, wherein the conductive powder is a mixture of two or more groups of conductive powders having different particle diameters. 4. The conductive powder according to claim 1, wherein 50 to 90% by weight has an average particle diameter of 0.02 to 5 μm, and 10 to 50% by weight has an average particle diameter of 1 to 10 μm. Or 1
Item 2. The photocurable conductive ink according to item 1. 5. The conductive powder has an average particle size of 0.02 to 0.02.
The shape of the conductive powder of 5 μm is spherical or microcrystalline,
The photocurable conductive ink according to any one of claims 1 to 4, wherein the shape of the conductive powder having an average particle size of 1 to 10 µm is a flake shape or a flake shape. 6. The photocurable conductive ink according to claim 1, wherein the glass frit is contained in an amount not exceeding 10% by weight. 7. Viscosity at a rotation speed of 100 s ⁻¹ is 10
The photocurable conductive ink according to any one of claims 1 to 6, which has a range of from 00 to 5000P. 8. A method for forming an electrode, comprising applying a photocurable conductive ink containing a conductive powder to a substrate in a pattern by printing, exposing to form a printed pattern, and then firing. 9. An electrode forming method comprising applying a photocurable conductive ink containing a conductive powder to a substrate in a pattern by lithographic offset printing, exposing to form a printed pattern, and then firing. . 10. A printed pattern is formed by applying the photocurable conductive ink according to claim 1 to a substrate in a pattern by printing, exposing to light, and then firing. Electrode formation method. 11. A method in which the photocurable conductive ink according to claim 1 is applied to a substrate in a pattern by lithographic offset printing, exposed to form a printed pattern, and then fired. Electrode forming method. 12. The lithographic offset printing is performed by a method in which an intaglio plate is filled with ink using a roll, a printing pattern formed by the intaglio plate is transferred to a lithographic blanket, and further transferred to an object to be coated. Item 12. The electrode forming method according to Item 9 or 11. 13. The method of claim 8, wherein said exposure is ionizing radiation.
13. The electrode forming method according to any one of claims 12 to 12. 14. The electrode forming method according to claim 8, wherein a printing pattern having an increased thickness is formed by applying printing a plurality of times and applying the printing repeatedly. 15. The method for forming an electrode according to claim 8, wherein the thickness of the printed coating film before firing is 16 μm or more. 16. The electrode forming method according to claim 8, wherein the thickness of the printed coating film after firing is 10 μm or less. 17. An electrode pattern obtained by the method for forming an electrode according to claim 8, wherein an organic component is substantially removed by a firing step to increase conductivity.