JP2014126609A - Conductive resin composition and conductive circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a conductive resin composition which does not impair optical characteristics and has a low specific resistance value and a conductive circuit formed by using the conductive resin composition.SOLUTION: A conductive resin composition comprises a carboxyl-group-containing resin, a conductive powder, a polyfunctional acrylate monomer, a photopolymerization initiator, a block isocyanate and an organic acid having no aromatic ring and two or more carboxyl groups. A conductive circuit formed by using the conductive resin composition is also provided.

Description

The present invention relates to a conductive resin composition and a conductive circuit formed using the conductive resin composition.

  Patent Documents 1 and 2 are known documents that disclose a conductive paste for forming a conductive pattern film on a substrate.

  Patent Documents 1 and 2 disclose a conductive paste containing a conductive powder, an organic binder, a photopolymerizable monomer, and a photopolymerization initiator.

  These conductive pastes are fired at a temperature of 500 ° C. or higher to remove the organic components in the paste, thereby ensuring the conductivity of the conductive circuit layer.

  In addition, the baking type conductive paste as described above generally contains glass frit together with the conductive powder, and by baking, the organic components in the paste are removed and the glass frit is melted to conduct the conductive pattern. And adhesion between the substrate and the substrate are ensured.

  However, since such a photosensitive conductive paste is baked at a temperature of 500 ° C. or higher, there is a problem that it is difficult to apply it on a heat-sensitive substrate. Accordingly, in order to ensure the conductivity of the conductive circuit layer, it has been desired to lower it to a desired low specific resistance value. However, when firing is not performed, the conductive paste does not necessarily have a desired low specific resistance value. Could not get.

Japanese Patent Laid-Open No. 2003-280181 Japanese Patent No. 4411113

  The present invention has been made to solve the above-described problems, and is applicable to a heat-sensitive substrate and uses a conductive resin composition that can ensure excellent conductivity and the conductive resin composition. It is an object of the present invention to provide a conductive circuit formed.

  Furthermore, the present invention is to provide a conductive resin composition capable of improving both coating film strength and adhesion to a base material, and a conductive circuit formed using this conductive resin composition. .

  Still another object of the present invention is to provide a conductive resin composition having a low specific resistance value without deteriorating optical characteristics, and a conductive circuit formed using this conductive resin composition.

  In order to solve the above-mentioned problems, the present invention has no carboxyl group-containing resin, conductive powder, polyfunctional (meth) acrylate monomer, photopolymerization initiator, blocked isocyanate, and aromatic ring, and two Provided is a conductive resin composition containing the above-described organic acid having a carboxyl group, and a conductive circuit formed using the conductive resin composition on a substrate.

According to the present invention, it can be applied to a heat-sensitive substrate, can ensure excellent conductivity, and is excellent in both coating film strength and adhesion to a base substrate, and further does not deteriorate optical properties. In addition, a conductive resin composition having a low specific resistance value and a conductive circuit formed using the conductive resin composition can be provided.

  First, the component mix | blended in the composition based on this invention is demonstrated.

(Components blended in the conductive resin composition)
(Carboxyl group-containing resin)
As the carboxyl group-containing resin, a known and commonly used resin compound containing a carboxyl group in the molecule can be used.
The carboxyl group-containing resin may be a carboxyl group-containing photosensitive resin containing a double bond, but a carboxyl group-containing resin not containing a double bond is preferred. Since the carboxyl group-containing resin not containing a double bond does not react with the (meth) acrylate monomer, no intermolecular bond is formed. For this reason, the carboxyl group-containing resin does not increase in molecular weight and is easily removed during development. As a result, the conductive powder becomes dense, and the specific resistance value of the conductive pattern film can be lowered.

  In addition, even if the carboxyl group-containing resin has a double bond at an extremely small ratio, the carboxyl group-containing resin containing such a double bond is within the range where the ratio has the same effect as the present invention. And “carboxyl group-containing resin not containing a double bond” of the present invention. Examples of the carboxyl group-containing resin not containing a double bond include those having a double bond equivalent of 10,000 or more.

  Among the carboxyl group-containing resins not containing a double bond, the carboxyl group-containing resin is particularly preferably a carboxyl group-containing resin containing neither a double bond nor an aromatic ring. By adopting a structure that does not contain an aromatic ring, the light absorption of the carboxyl group-containing resin itself can be suppressed, and the photoreactivity of the (meth) acrylate monomer can be relatively improved.

  Specific examples of the carboxyl group-containing resin not containing a double bond and an aromatic ring are listed below.

(1) a carboxyl group-containing resin obtained by copolymerizing with an unsaturated carboxylic acid such as (meth) acrylic acid and one or more other compounds having an unsaturated double bond;
(2) a carboxyl group-containing resin obtained by copolymerizing an acid anhydride having an unsaturated double bond such as maleic anhydride and a compound having another unsaturated double bond;
(3) a carboxyl group-containing resin obtained by reacting a compound having a hydroxyl group with a copolymer of an acid anhydride having an unsaturated double bond and another compound having an unsaturated double bond;
(4) A saturated carboxylic acid is reacted with a copolymer of an epoxy group, a compound having an unsaturated double bond, and a compound having an unsaturated double bond, and a polybasic acid anhydride is reacted with the resulting secondary hydroxyl group. Carboxyl group-containing resin obtained by
(5) A carboxyl group-containing resin obtained by reacting a hydroxyl group-containing polymer with a polybasic acid anhydride may be mentioned, but is not limited thereto.
In addition, in this specification, (meth) acrylic acid is a term that collectively refers to acrylic acid, methacrylic acid, and mixtures thereof, and the same applies to other similar expressions.

Since the carboxyl group-containing resin as described above has many free carboxyl groups in the side chain of the backbone polymer, development with a dilute alkaline aqueous solution is possible.
The acid value of the carboxyl group-containing resin is preferably in the range of 40 to 200 mgKOH / g, more preferably in the range of 45 to 120 mgKOH / g. When the acid value of the carboxyl group-containing resin is less than 40 mgKOH / g, alkali development becomes difficult. On the other hand, when the acid value exceeds 200 mgKOH / g, dissolution of the exposed area by the developer proceeds and the line becomes thinner than necessary. Depending on the case, the exposed portion and the unexposed portion may be dissolved and separated with a developer without distinction, and it becomes difficult to draw a normal conductive pattern, which is not preferable.

  The weight average molecular weight of the carboxyl group-containing resin varies depending on the resin skeleton, but is generally in the range of 2,000 to 150,000, more preferably 5,000 to 100,000. If the mass average molecular weight is less than 2,000, the tack-free performance may be inferior, the moisture resistance of the conductive pattern film after exposure may be poor, the film may be reduced during development, and the resolution may be greatly inferior. On the other hand, when the mass average molecular weight exceeds 150,000, developability may be remarkably deteriorated, and storage stability may be inferior.

  The blending amount of such a carboxyl group-containing resin is preferably 3 to 50% by mass and more preferably 5 to 30% by mass in the total conductive resin composition. When the amount is less than the above range, the strength of the conductive pattern film is lowered, which is not preferable. On the other hand, when the amount is larger than the above range, the viscosity becomes high or the coating property and the like are lowered, which is not preferable.

(Conductive powder)
First, any material can be used for the conductive powder as long as it imparts conductivity in the conductive resin composition. Examples of such conductive powder include Ag, Au, Pt, Pd, Ni, Cu, Al, Sn, Pb, Zn, Fe, Ir, Os, Rh, W, Mo, Ru, and the like. Among these, Ag is preferable. These conductive powders may be used in the form of a single component, but may be used in the form of an alloy or oxide. Furthermore, tin oxide (SnO ₂ ), indium oxide (In ₂ O ₃ ), ITO (Indium Tin Oxide), or the like can also be used. The conductive powder may be carbon powder such as carbon black, graphite, or carbon nanotube. However, care should be taken because the light transmittance is lowered.

  The shape of the conductive powder is not particularly limited, but is preferably other than flakes, particularly preferably acicular or spherical. As a result, the light transmittance is improved, and a conductive pattern film having excellent resolution can be formed.

  Such a conductive powder preferably has a maximum particle size of 30 μm or less in order to form fine lines. By setting the maximum particle size to 30 μm or less, the resolution of the conductive pattern film is improved.

  In addition, the conductive powder is an average particle diameter of 10 random conductive powders observed at 10,000 times using an electron microscope (SEM), and the range is 0.1 to 10 μm or less. preferable. If the average particle size is smaller than this range, the resistance value increases due to an increase in contact resistance, which is not preferable. On the other hand, when the average particle size is larger than the above range, when a conductor pattern is printed using a mesh screen plate, workability is deteriorated due to clogging of the screen, and formation of fine lines becomes difficult, which is not preferable. In addition, it is preferable to use the thing of the magnitude | size of 0.5-3.5 micrometers in the average particle diameter measured with the micro track | truck.

  The blending ratio of such conductive powder is preferably 800 to 900 parts by mass with respect to 100 parts by mass of the carboxyl group-containing resin. When there are too few compounding ratios of electroconductive powder, there exists a possibility that resistance value of an electroconductive resin composition may become high and sufficient electroconductivity may not be obtained. On the other hand, if a large amount of conductive powder is contained, the light transmission property is deteriorated and the formation of the conductive pattern film by exposure is deteriorated.

(Multifunctional (meth) acrylate monomer)
As the (meth) acrylate monomer, a polyfunctional (meth) acrylate monomer (bifunctional or higher (meth) acrylate monomer) is used. The reason for using the polyfunctional (meth) acrylate monomer is that the photoreactivity is improved and the resolution is excellent as compared with the case where the number of functional groups is one.

  Examples of the (meth) acrylate monomer include conventionally known polyester (meth) acrylate, polyether (meth) acrylate, urethane (meth) acrylate, carbonate (meth) acrylate, and epoxy (meth) acrylate. Specifically, hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate and 2-hydroxypropyl acrylate; diacrylates of glycols such as ethylene glycol, methoxytetraethylene glycol, polyethylene glycol, and propylene glycol; N, N-dimethylacrylamide Acrylamides such as N-methylol acrylamide and N, N-dimethylaminopropyl acrylamide; aminoalkyl acrylates such as N, N-dimethylaminoethyl acrylate and N, N-dimethylaminopropyl acrylate; hexanediol, trimethylolpropane, Polyhydric alcohols such as pentaerythritol, dipentaerythritol, tris-hydroxyethyl isocyanurate or the like; Multivalent acrylates such as a peroxide adduct, a propylene oxide adduct, or an ε-caprolactone adduct; a polyvalent such as phenoxy acrylate, bisphenol A diacrylate, and ethylene oxide adduct or propylene oxide adduct of these phenols Acrylates; glyceryl diglycidyl ether, glycerin triglycidyl ether, trimethylolpropane triglycidyl ether, polyglycerides of glycidyl ether such as triglycidyl isocyanurate; not limited to the above, polyether polyol, polycarbonate diol, hydroxyl-terminated polybutadiene, Polyacrylate polyol and other polyols are directly acrylated or urethane acrylated via diisocyanate Acrylates and melamine acrylates, and at least one of each methacrylate corresponding to the acrylate.

  Further, an epoxy acrylate resin obtained by reacting acrylic acid with a polyfunctional epoxy resin such as a cresol novolac type epoxy resin, or a hydroxy acrylate such as pentaerythritol triacrylate and a diisocyanate such as isophorone diisocyanate on the hydroxyl group of the epoxy acrylate resin. An epoxy urethane acrylate compound obtained by reacting a half urethane compound may be used as a photoreactive monomer. Such an epoxy acrylate resin can improve photocurability without deteriorating the touch drying property.

  Among these, a tetrafunctional (meth) acrylate monomer is preferable. Examples of tetrafunctional (meth) acrylate monomers include pentaerythritol tetraacrylate and pentaerythritol tetramethacrylate.

The tetrafunctional (meth) acrylate monomer is preferably a tetrafunctional urethane acrylate monomer or ester acrylate described in the chemical formulas (I) and (II).

In formula (I),
X ¹ represents a group containing an acryloyloxy group.

X ² represents a group containing a methacryloyloxy group.

X ³ and X ⁴ each independently represent a group containing an acryloyloxy group or a group containing a methacryloyloxy group. However, at least one of X ³ and X ⁴ represents a group containing a methacryloyloxy group.

L ¹ and L ² are each independently

Represents.

* Represents a binding site with Z.

Z represents a divalent linking group.

As the acrylate monomer, L ¹ and L ² in the general formula (I) are

It is preferable that it is urethane acrylate represented by these. In formula (III), * represents a binding site with Z.

Furthermore, as a monomer represented by general formula (I), urethane acrylate represented by the following formula (IV) is preferable.

In formula (IV),
Z ¹ represents an alkylene group.

R ¹ represents a hydrogen atom.

R ² represents a methyl group.

R ³ and R ⁴ each independently represents a hydrogen atom or a methyl group. However, at least one of R ³ and R ⁴ represents a methyl group.

  Furthermore, urethane acrylate or ester acrylate in which acrylic and methacryl are in a one-to-one relationship is particularly preferable as the tetrafunctional acrylate monomer.

  As such a 4-functional urethane acrylate or ester acrylate, for example, a product obtained by adding acrylic acid to glycidyl methacrylate and reacting the generated hydroxyl group with diisocyanate or dicarboxylic acid is preferable.

  Examples of commercially available products of tetrafunctional urethane acrylate include NK Oligo U-4HA (trade name, manufactured by Shin-Nakamura Chemical Co., Ltd.).

  Of these tetrafunctional acrylate monomers, tetrafunctional acrylate monomers represented by the formula (I) are preferred. Since this tetrafunctional acrylate monomer has a large number of functional groups, it has excellent photoreactivity and excellent resolution.

In addition, since X ¹ and X ² of the tetrafunctional acrylate monomer are different from each other, the reaction between X ¹ and X ² in the molecule is slow during photocuring. However, the acrylate monomer X ¹ or X ² reacts faster than the intramolecular reaction between the other acrylate monomers X ¹ or X ² . Thereby, since an intermolecular bond is formed between a plurality of acrylate monomers, the conductive resin composition is further cured and contracted. And only by heat-processing at low temperature, intermolecular reaction is further accelerated | stimulated and the conductive resin composition fully cures and shrinks. As a result, it is considered that the conductive powder becomes dense and the specific resistance value of the conductive pattern film is further lowered.

  The blending amount of such a tetrafunctional acrylate monomer is not particularly limited, but a ratio of 10 to 100 parts by mass, more preferably 20 to 80 parts by mass is appropriate with respect to 100 parts by mass of the carboxyl group-containing resin. It is. When the blending amount is less than 10 parts by mass, photocurability is lowered, and formation of a conductive pattern line is difficult due to alkali development after irradiation with active energy rays. On the other hand, when the amount exceeds 100 parts by mass, the solubility in an alkaline aqueous solution is lowered and the conductive pattern film becomes brittle.

(Photopolymerization initiator)
The photopolymerization initiator is not particularly limited, and may be a benzoin type or a phosphine oxide type, but is represented by the oxime ester type having a group represented by the following general formula (V) or the following general formula (VI). It is preferable to use an acetophenone-based photopolymerization initiator having the above group.

     In formula (V), R6 represents a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or a phenyl group, and R7 represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.

  In formula (VI), R8 and R9 each independently represents an alkyl group having 1 to 12 carbon atoms or an arylalkyl group, and R10 and R11 each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. Or R10 and R11 may be bonded to form a cyclic alkyl ether group.

  Among the oxime ester-based photopolymerization initiators, CGI-325, IRGACURE OXE01, IRGACURE OXE02 manufactured by BASF Japan, N-1919 manufactured by ADEKA, NCI-831, manufactured by Nippon Chemical Industry Co., Ltd. TOE-004 is preferred. Further, IRGACURE 389 may be used as a photopolymerization initiator. In addition, these photoinitiators can be used individually or in combination of 2 or more types.

  Examples of the acetophenone photopolymerization initiator having a group represented by the general formula (VI) include 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropanone-1, 2-benzyl-2. -Dimethylamino-1- (4-morpholinophenyl) -butan-1-one, 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] Examples include -1-butanone and N, N-dimethylaminoacetophenone. Examples of commercially available products include Irgacure 907, Irgacure 369, and Irgacure 379 manufactured by BASF Japan.

The blending amount of such a photopolymerization initiator is not particularly limited, but is suitably 0.01 to 30 parts by mass, preferably 0.5 to 15 parts by mass with respect to 100 parts by mass of the carboxyl group-containing resin. It is. When the blending amount of the photopolymerization initiator is less than 0.01 parts by mass, the photocurability is insufficient, and the conductive pattern film may be peeled off or the characteristics of the conductive pattern film such as chemical resistance may be deteriorated. Absent. On the other hand, if it exceeds 30 parts by mass, light absorption on the surface of the conductive pattern film of the photopolymerization initiator becomes violent, and the deep curability tends to decrease, which is not preferable.
(Block isocyanate compound)
In order to improve the toughness of the cured film obtained from the conductive resin composition and the adhesion to the base substrate, a compound having a blocked isocyanate group in one molecule, that is, a blocked isocyanate compound, and the like can be mentioned.

  The blocked isocyanate group contained in the blocked isocyanate compound is a group in which the isocyanate group is protected by reaction with a blocking agent and temporarily deactivated. When heated to a predetermined temperature, the blocking agent is dissociated to produce isocyanate groups.

  As the blocked isocyanate compound, an addition reaction product of an isocyanate compound and an isocyanate blocking agent is used. Examples of the isocyanate compound that can react with the blocking agent include isocyanurate type, biuret type, and adduct type. As this isocyanate compound, for example, the same aromatic polyisocyanate, aliphatic polyisocyanate or alicyclic polyisocyanate as described above is used.

  Examples of the isocyanate blocking agent include phenolic blocking agents such as phenol, cresol, xylenol, chlorophenol and ethylphenol; lactam blocking agents such as ε-caprolactam, δ-palerolactam, γ-butyrolactam and β-propiolactam; Active methylene blocking agents such as ethyl acetoacetate and acetylacetone; methanol, ethanol, propanol, butanol, amyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, propylene glycol monomethyl ether, benzyl Ether, methyl glycolate, butyl glycolate, diacetone alcohol, lactic acid And alcohol-based blocking agents such as ethyl lactate; oxime-based blocking agents such as formaldehyde oxime, acetaldoxime, acetoxime, methyl ethyl ketoxime, diacetyl monooxime, cyclohexane oxime; butyl mercaptan, hexyl mercaptan, t-butyl mercaptan, thiophenol, Mercaptan block agents such as methylthiophenol and ethylthiophenol; Acid amide block agents such as acetic acid amide and benzamide; Imide block agents such as succinimide and maleic imide; Amines such as xylidine, aniline, butylamine and dibutylamine Blocking agents; imidazole blocking agents such as imidazole and 2-ethylimidazole; imine blocking agents such as methyleneimine and propyleneimine It is.

The block isocyanate compound may be commercially available, for example, 7950, 7951, 7960, 7961, 7982, 7990, 7991, 7992 (above, trade name, manufactured by Baxenden) Sumijour BL-3175, BL-4165, BL-1100, BL-1265, Death Module TPLS-2957, TPLS-2062, TPLS-2078, TPLS-2117, Desmotherm 2170, Desmotherm 2265 (supplied by Sumitomo Bayer Urethane Co., Ltd., trade name), Coronate 2512, Coronate 2513, Coronate 2520 (supplied by Nippon Polyurethane Industry Co., Ltd., trade name), B-830, B-815, B-846, B-870, B-874, B-882 (Mitsui Takeda Chemical Co., trade name), TPA -B80E, 17 Examples include B-60PX, E402-B80T, MF-B60B, MF-K60B, SBN-70D (trade name, manufactured by Asahi Kasei Chemicals), Karenz MOI-BM (trade name, manufactured by Showa Denko KK), and the like. In addition, Sumidur BL-3175 and BL-4265 are obtained using methyl ethyl oxime as a blocking agent. The above-mentioned compounds having a blocked isocyanate group are used singly or in combination of two or more. be able to.

  The compounding amount of such a compound having a blocked isocyanate group is suitably 1 to 100 parts by mass, more preferably 2 to 70 parts by mass with respect to 100 parts by mass of the carboxyl group-containing resin. When the amount is less than 1 part by mass, sufficient toughness of the coating film cannot be obtained, which is not preferable. On the other hand, when it exceeds 100 mass parts, storage stability falls and it is not preferable.

  The dissociation temperature of the blocking agent of the blocked isocyanate is not particularly limited, but it is desirable that the blocking agent does not react at the temporary drying temperature (for example, 80 to 90 ° C.) but reacts at the final heat treatment. A temperature higher than the temporary drying temperature, for example, 100 ° C. or higher is preferable. In addition, when a polyester-based resin is used as the base material, for example, the dissociation temperature of the blocking agent of the blocked isocyanate can be prevented from being discolored, for example, 140, because the base material is easily discolored if the heat treatment temperature is too high. It is preferable that heat treatment can be performed at a temperature at which the base material is not discolored at a temperature not higher than ° C.

(Organic acid having no aromatic ring and having two or more carboxyl groups)
By using an organic acid that does not have an aromatic ring and has two or more carboxyl groups as the organic acid, the light absorption of the organic acid itself is suppressed, and the photoreactivity of the polyfunctional acrylate monomer is relatively high. Can be improved and excellent resolution can be obtained. Moreover, a composition with a low specific resistance value can be obtained. That is, according to the inventor's new knowledge, by using an organic acid that does not have an aromatic ring, the light transmittance is improved and sufficient curing shrinkage is achieved. Is in a niche state without being separated, and the specific resistance value can be reduced. Moreover, when the organic acid to mix | blend has a 2 or more carboxyl group, the specific resistance value was able to be reduced unexpectedly.

  In other words, the organic acid having no aromatic ring means an organic acid of an aliphatic compound. Examples of the organic acid according to the present invention include dicarboxylic acid, tricarboxylic acid, tetracarboxylic acid, pentacarboxylic acid, and hexacarboxylic acid, and dicarboxylic acid is particularly preferable. Specific examples of the dicarboxylic acid include 2,2'-thioniacetic acid, adipic acid, glutaric acid, oxalic acid, tartaric acid, malic acid, maleic acid, fumaric acid, malonic acid, and succinic acid. Specific examples of the tricarboxylic acid include aconitic acid, citric acid, isocitric acid, and oxalosuccinic acid. Specific examples of the tetracarboxylic acid include 1,2,3,4-butanetetracarboxylic acid and ethynetetracarboxylic acid. Examples of hexacarboxylic acid include 1,2,3,4,5,6-cyclohexacarboxylic acid.

  In the present invention, one or more of the above organic acids can be contained, and the amount of the organic acid is in the range of 0.1 to 5 parts by mass with respect to 100 parts by mass of the conductive powder. It is preferable. When the blending amount of the organic acid is less than 0.1 parts by mass with respect to 100 parts by mass of the conductive powder, the reaction between the conductive powder and the carboxyl group-containing resin occurs, and the long-term storage stability is reduced. When the amount exceeds 5 parts by mass, it is not preferable because moisture in the air is easily absorbed.

  In order to further improve the effects of the present invention, or to exhibit further effects within a range that does not impair the effects of the present invention, the conductive resin composition of the present invention is the above-described carboxyl group-containing resin, conductive property. Along with the powder, the polyfunctional acrylate monomer, the photopolymerization initiator, and the organic acid, other components exemplified below can be included.

(Dispersant)
By mix | blending a dispersing agent, the dispersibility and sedimentation property of a conductive resin composition can be improved.

  Examples of the dispersing agent include, for example, ANTI-TERRA-U, ANTI-TERRA-U100, ANTI-TERRA-204, ANTI-TERRA-205, DISPERBYK-101, DISPERBYK-102, DISPERBYK-103, DISPERBYK-106, DISPERBYK-108. DISPERBYK-109, DISPERBYK-110, DISPERBYK-111, DISPERBYK-112, DISPERBYK-116, DISPERBYK-130, DISPERBYK-140, DISPERBYK-142, DISPERBYK-145, DISPERBYK-161, DISPERBY63-62 -164, DISPERBYK- 66, DISPERBYK-167, DISPERBYK-168, DISPERBYK-170, DISPERBYK-171, DISPERBYK-174, DISPERBYK-180, DISPERBYK-182, DISPERBYK-183, DISPERBYK-185, DISPERBYK-184, DISPERBY92 DISPERBYK-2000, DISPERBYK-2001, DISPERBYK-2009, DISPERBYK-2020, DISPERBYK-2025, DISPERBYK-2050, DISPERBYK-2070, DISPERBYK-2095, DISPERBYK-2096, DISPERBYK-150P, DISPERBYK-2150 -P104S, BYK-P105, BYK-9076, BYK-9077, BYK-220S (manufactured by BYK Japan), Dispalon 2150, Disparon 1210, Disparon KS-860, Disparon KS-873N, Disparon 7004, Disparon 1830, Disparon 1860, Disparon 1850, Disparon DA-400N, Disparon PW-36, Disparon DA-703-50 (manufactured by Enomoto Kasei Co., Ltd.), Floren G-450, Floren G-600, Floren G-820, Floren G-700, Floren DOPA-44 and Florene DOPA-17 (manufactured by Kyoeisha Chemical Co., Ltd.) can be mentioned.

  The content of the dispersant is preferably 0.1 to 10 parts by mass, and preferably 0.5 to 5 parts by mass with respect to 100 parts by mass of the conductive powder in order to effectively achieve the above object.

(Photopolymerization inhibitor)
By adding the photopolymerization inhibitor, it is possible to suppress a certain amount of radical polymerization in accordance with the type of polymerization inhibitor and the amount of the addition among the radical polymerization that occurs inside the conductive resin composition by exposure. Thereby, the photoreaction with respect to weak light like scattered light can be suppressed. Therefore, since a finer line of the conductive pattern film can be formed sharply, it can be preferably used. The photopolymerization inhibitor is not particularly limited as long as it can be used as a photopolymerization inhibitor. For example, p-benzoquinone, naphthoquinone, di-t-butyl paracresol, hydroquinone monomethyl ether, α-naphthol, acetanidin Examples include acetate, hydrazine hydrochloride, trimethylbenzylammonium chloride, dinitrobenzene, picric acid, quinone dioxime, pyrogallol, tannic acid, resormin, cuperone, phenothiazine, and the like.

  The addition amount of the photopolymerization inhibitor is preferably 0.001 to 3 parts by mass, more preferably 0.01 to 2 parts by mass with respect to 100 parts by mass of the carboxyl group-containing resin. If it is less than this range, the effect of inhibiting polymerization is not exhibited, and even a low exposure amount due to light scattering is cured, and the line shape tends to be thickened. Also, if it exceeds this range, the sensitivity is lowered and a large amount of exposure is required, so care must be taken.

(Filler)
In the conductive resin composition of the present invention, a filler can be blended as necessary in order to increase the physical strength of the coating film. As such a filler, publicly known and commonly used inorganic or organic fillers can be used, and barium sulfate, silica, hydrotalcite and talc are particularly preferably used.

(Thermosetting component)
A thermosetting component can be added to the conductive resin composition of the present invention in order to impart heat resistance. Examples of thermosetting components used in the present invention include amine resins such as melamine resins and benzoguanamine resins, block isocyanate compounds, cyclocarbonate compounds, polyfunctional epoxy compounds, polyfunctional oxetane compounds, episulfide resins, melamine derivatives, and the like. A thermosetting resin can be used. Particularly preferred is a thermosetting component having two or more cyclic ether groups and / or cyclic thioether groups (hereinafter abbreviated as cyclic (thio) ether groups) in the molecule.

  Such a thermosetting component having two or more cyclic (thio) ether groups in the molecule is either one of the three-, four- or five-membered cyclic ether groups in the molecule, or the cyclic thioether group, or two of them. A compound having at least two epoxy groups in the molecule, that is, a polyfunctional epoxy compound, a compound having at least two oxetanyl groups in the molecule, that is, a polyfunctional compound. Examples include oxetane compounds, compounds having two or more thioether groups in the molecule, that is, episulfide resins.

  Examples of the polyfunctional epoxy compound include jER828, jER834, jER1001, jER1004 manufactured by Mitsubishi Chemical Corporation, Epicron 840 manufactured by DIC, Epicron 850, Epicron 1050, Epicron 2055, Epototo YD-011, YD manufactured by Tohto Kasei Co., Ltd. -013, YD-127, YD-128, D.C. E. R. 317, D.E. E. R. 331, D.D. E. R. 661, D.D. E. R. 664, Sumitomo Epoxy ESA-011, ESA-014, ELA-115, ELA-128, manufactured by Sumitomo Chemical Co., Ltd., A.A. E. R. 330, A.I. E. R. 331, A.I. E. R. 661, A.I. E. R. Bisphenol A type epoxy resin such as 664 (all trade names); jERYL903 manufactured by Mitsubishi Chemical, Epicron 152, Epicron 165 manufactured by DIC, Epototo YDB-400, YDB-500 manufactured by Tohto Kasei Co., Ltd., manufactured by Dow Chemical Of D. E. R. 542, Sumitomo Epoxy ESB-400, ESB-700 manufactured by Sumitomo Chemical Co., Ltd., A.A. E. R. 711, A.I. E. R. Brominated epoxy resins such as 714 (both trade names); jER152 and jER154 manufactured by Mitsubishi Chemical Corporation, and D.C. E. N. 431, D.D. E. N. 438, Epicron N-730, Epicron N-770, Epicron N-865 manufactured by DIC, Epototo YDCN-701, YDCN-704 manufactured by Tohto Kasei Co., Ltd., EPPN-201, EOCN-1025, EOCN manufactured by Nippon Kayaku Co., Ltd. -1020, EOCN-104S, RE-306, Sumitomo Epoxy ESCN-195X, ESCN-220, manufactured by Sumitomo Chemical Co., Ltd. E. R. Novolak type epoxy resins such as ECN-235, ECN-299, etc. (both trade names); Epicron 830 manufactured by DIC, jER807 manufactured by Mitsubishi Chemical Co., Ltd. Epototo YDF-170, YDF-175, YDF-2004 manufactured by Tohto Kasei Co., Ltd. (All trade names) bisphenol F-type epoxy resin; hydrogenated bisphenol A-type epoxy resins such as Epototo ST-2004, ST-2007, ST-3000 (trade name) manufactured by Toto Kasei Co., Ltd .; jER604, Etototo YH-434 manufactured by Tohto Kasei Co., Ltd. Sumitomo Chemical Co., Ltd. Sumi-epoxy ELM-120, etc. (all trade names) glycidylamine type epoxy resin; Hydantoin type epoxy resin; 2021 etc. (all trade names) alicyclic epoxy resin; Y manufactured by Mitsubishi Chemical Corporation -933, manufactured by Dow Chemical Company of T. E. N. , EPPN-501, EPPN-502, etc. (all trade names) trihydroxyphenylmethane type epoxy resin; Mitsubishi Chemical Corporation YL-6056, YX-4000, YL-6121 (all trade names) Type or biphenol type epoxy resin or a mixture thereof; bisphenol S type epoxy resin such as EBPS-200 manufactured by Nippon Kayaku Co., Ltd., EPX-30 manufactured by Asahi Denka Kogyo Co., Ltd., EXA-1514 manufactured by DIC Co., Ltd .; Bisphenol A novolac type epoxy resin such as jER157S (trade name) manufactured by KK; tetraphenylolethane type epoxy resin such as jERYL-931 (all trade name) manufactured by Mitsubishi Chemical; TEPIC manufactured by Nissan Chemical Industries, Ltd. ( All are trade names) heterocyclic epoxy resins; Nigiri such as Bremer DGT manufactured by Nippon Oil & Fats Co., Ltd. Zylphthalate resin; Tetraglycidylxylenoylethane resin such as ZX-1063 manufactured by Tohto Kasei Co., Ltd .; Naphthalene such as ESN-190, ESN-360 manufactured by Nippon Steel Chemical Co., Ltd., HP-4032, EXA-4750, EXA-4700 manufactured by DIC Group-containing epoxy resin; epoxy resin having a dicyclopentadiene skeleton such as HP-7200 and HP-7200H manufactured by DIC; glycidyl methacrylate copolymer epoxy resin such as CP-50S and CP-50M manufactured by NOF Corporation; and cyclohexyl Copolymerized epoxy resin of maleimide and glycidyl methacrylate; epoxy-modified polybutadiene rubber derivative (for example, PB-3600 manufactured by Daicel Chemical Industries), CTBN-modified epoxy resin (for example, YR-102, YR-450 manufactured by Toto Kasei Co., Ltd.), etc. Is mentioned But, the present invention is not limited to these. These epoxy resins can be used alone or in combination of two or more. Among these, a novolac type epoxy resin, a heterocyclic epoxy resin, a bisphenol A type epoxy resin or a mixture thereof is particularly preferable.

  Examples of the polyfunctional oxetane compound include bis [(3-methyl-3-oxetanylmethoxy) methyl] ether, bis [(3-ethyl-3-oxetanylmethoxy) methyl] ether, 1,4-bis [(3-methyl -3-Oxetanylmethoxy) methyl] benzene, 1,4-bis [(3-ethyl-3-oxetanylmethoxy) methyl] benzene, (3-methyl-3-oxetanyl) methyl acrylate, (3-ethyl-3-oxetanyl) In addition to polyfunctional oxetanes such as methyl acrylate, (3-methyl-3-oxetanyl) methyl methacrylate, (3-ethyl-3-oxetanyl) methyl methacrylate and oligomers or copolymers thereof, oxetane alcohol and novolak resin, Poly (p-hydroxystyrene), cardo-type bisphenol Le ethers, calixarenes, calix resorcin arenes, or the like ethers of a resin having a hydroxyl group such as silsesquioxane and the like. In addition, a copolymer of an unsaturated monomer having an oxetane ring and an alkyl (meth) acrylate is also included.

  Examples of the compound having two or more cyclic thioether groups in the molecule include bisphenol A type episulfide resin YL7000 manufactured by Mitsubishi Chemical Corporation. Moreover, episulfide resin etc. which replaced the oxygen atom of the epoxy group of the novolak-type epoxy resin with the sulfur atom using the same synthesis method can be used.

  The conductive resin composition of the present invention includes two or more isocyanate groups or blocked isocyanate groups in one molecule in order to improve the curability of the conductive resin composition and the toughness of the resulting cured film. A compound having can be added. Such a compound having two or more isocyanate groups or blocked isocyanate groups in one molecule is a compound having two or more isocyanate groups in one molecule, that is, a polyisocyanate compound, or two in one molecule. Examples thereof include compounds having the above blocked isocyanate groups, that is, blocked isocyanate compounds.

  As the polyisocyanate compound, for example, aromatic polyisocyanate, aliphatic polyisocyanate or alicyclic polyisocyanate is used. Specific examples of the aromatic polyisocyanate include 4,4′-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, naphthalene-1,5-diisocyanate, o-xylylene diisocyanate, m- Examples include xylylene diisocyanate and 2,4-tolylene dimer. Specific examples of the aliphatic polyisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate, methylene diisocyanate, trimethylhexamethylene diisocyanate, 4,4-methylenebis (cyclohexyl isocyanate), and isophorone diisocyanate. Specific examples of the alicyclic polyisocyanate include bicycloheptane triisocyanate. In addition, adduct bodies, burette bodies, and isocyanurate bodies of the isocyanate compounds listed above may be mentioned.

  The blocked isocyanate group contained in the blocked isocyanate compound is a group in which the isocyanate group is protected by reaction with a blocking agent and temporarily deactivated. When heated to a predetermined temperature, the blocking agent is dissociated to produce isocyanate groups.

  As the blocked isocyanate compound, an addition reaction product of an isocyanate compound and an isocyanate blocking agent is used. Examples of the isocyanate compound that can react with the blocking agent include isocyanurate type, biuret type, and adduct type. As this isocyanate compound, for example, the same aromatic polyisocyanate, aliphatic polyisocyanate or alicyclic polyisocyanate as described above is used.

  Examples of isocyanate blocking agents include phenolic blocking agents such as phenol, cresol, xylenol, chlorophenol and ethylphenol; lactam blocking agents such as ε-caprolactam, δ-valerolactam, γ-butyrolactam and β-propiolactam. Active methylene blocking agents such as ethyl acetoacetate and acetylacetone; methanol, ethanol, propanol, butanol, amyl alcohol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, propylene glycol monomethyl ether, Benzyl ether, methyl glycolate, butyl glycolate, diacetone alcohol, lactic acid And alcohol-based blocking agents such as ethyl lactate; oxime-based blocking agents such as formaldehyde oxime, acetaldoxime, acetoxime, methyl ethyl ketoxime, diacetyl monooxime, cyclohexane oxime; butyl mercaptan, hexyl mercaptan, t-butyl mercaptan, thiophenol, Mercaptan block agents such as methylthiophenol and ethylthiophenol; Acid amide block agents such as acetic acid amide and benzamide; Imide block agents such as succinimide and maleic imide; Amines such as xylidine, aniline, butylamine and dibutylamine Blocking agents; imidazole blocking agents such as imidazole and 2-ethylimidazole; imine blocking agents such as methyleneimine and propyleneimine It is.

  The block isocyanate compound may be commercially available, for example, 7950, 7951, 7960, 7961, 7982, 7990, 7991, 7992 (above, trade name, manufactured by Baxenden) Sumijour BL-3175, BL-4165, BL-1100, BL-1265, Death Module TPLS-2957, TPLS-2062, TPLS-2078, TPLS-2117, Desmotherm 2170, Desmotherm 2265 (supplied by Sumitomo Bayer Urethane Co., Ltd., trade name), Coronate 2512, Coronate 2513, Coronate 2520 (supplied by Nippon Polyurethane Industry Co., Ltd., trade name), B-830, B-815, B-846, B-870, B-874, B-882 (Mitsui Takeda Chemical Co., trade name), TPA -B80E, 17 Examples include B-60PX, E402-B80T, MF-B60B, MF-K60B, SBN-70D (trade name, manufactured by Asahi Kasei Chemicals), Karenz MOI-BM (trade name, manufactured by Showa Denko KK), and the like. Sumijoules BL-3175 and BL-4265 are obtained using methyl ethyl oxime as a blocking agent.

  The compounds having two or more isocyanate groups or blocked isocyanate groups in one molecule can be used singly or in combination of two or more.

The compounding amount of the compound having two or more isocyanate groups or blocked isocyanate groups in one molecule is 1 to 100 parts by mass, more preferably 2 to 100 parts by mass of the carboxyl group-containing resin. A proportion of 70 parts by weight is appropriate. When the amount is less than 1 part by mass, sufficient toughness of the coating film cannot be obtained, which is not preferable. On the other hand, when it exceeds 100 mass parts, storage stability falls and it is not preferable.

(Thermosetting catalyst)
When using the thermosetting component which has a 2 or more cyclic (thio) ether group in the said molecule | numerator in the conductive resin composition of this invention, it is preferable to contain a thermosetting catalyst. Examples of such thermosetting catalysts include imidazole, 2-methylimidazole, 2-ethylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, 4-phenylimidazole, 1-cyanoethyl-2-phenylimidazole. Imidazole derivatives such as 1- (2-cyanoethyl) -2-ethyl-4-methylimidazole; dicyandiamide, benzyldimethylamine, 4- (dimethylamino) -N, N-dimethylbenzylamine, 4-methoxy-N, N -Amine compounds such as dimethylbenzylamine and 4-methyl-N, N-dimethylbenzylamine; hydrazine compounds such as adipic acid dihydrazide and sebacic acid dihydrazide; and phosphorus compounds such as triphenylphosphine. Examples of commercially available products include 2MZ-A, 2MZ-OK, 2PHZ, 2P4BHZ, 2P4MHZ (both trade names of imidazole compounds) manufactured by Shikoku Kasei Kogyo Co., Ltd., and U-CAT (registered by San Apro). Trademarks) 3503N, U-CAT3502T (all are trade names of blocked isocyanate compounds of dimethylamine), DBU, DBN, U-CATSA102, U-CAT5002 (all are bicyclic amidine compounds and salts thereof), and the like. In particular, it is not limited to these, as long as it is a thermosetting catalyst for epoxy resins or oxetane compounds, or a catalyst that promotes the reaction of epoxy groups and / or oxetanyl groups with carboxyl groups, either alone or in combination of two or more. Can be used. Also, guanamine, acetoguanamine, benzoguanamine, melamine, 2,4-diamino-6-methacryloyloxyethyl-S-triazine, 2-vinyl-2,4-diamino-S-triazine, 2-vinyl-4,6-diamino S-triazine derivatives such as -S-triazine and isocyanuric acid adducts and 2,4-diamino-6-methacryloyloxyethyl-S-triazine and isocyanuric acid adducts can also be used. A compound that also functions in combination with the thermosetting catalyst.

  The blending amount of these thermosetting catalysts is sufficient in the usual quantitative ratio, for example, with respect to 100 parts by mass of the carboxyl group-containing resin or thermosetting component having two or more cyclic (thio) ether groups in the molecule. The amount is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 15 parts by mass.

(Thermal polymerization inhibitor)
The thermal polymerization inhibitor can be used to prevent thermal polymerization or temporal polymerization of the conductive resin composition of the present invention. Examples of thermal polymerization inhibitors include 4-methoxyphenol, hydroquinone, alkyl or aryl-substituted hydroquinone, t-butylcatechol, pyrogallol, 2-hydroxybenzophenone, 4-methoxy-2-hydroxybenzophenone, cuprous chloride, phenothiazine, chloranil. , Naphthylamine, β-naphthol, 2,6-di-tert-butyl-4-cresol, 2,2′-methylenebis (4-methyl-6-tert-butylphenol), pyridine, nitrobenzene, dinitrobenzene, picric acid, 4 -Toluidine, methylene blue, copper and organic chelating agent reactant, methyl salicylate, and phenothiazine, nitroso compound, chelate of nitroso compound and Al, and the like.

(Chain transfer agent)
In the conductive resin composition of the present invention, known N-phenylglycines, phenoxyacetic acids, thiophenoxyacetic acids, mercaptothiazole and the like can be used as chain transfer agents in order to improve sensitivity. Specific examples of chain transfer agents include, for example, chain transfer agents having a carboxyl group such as mercaptosuccinic acid, mercaptoacetic acid, mercaptopropionic acid, methionine, cysteine, thiosalicylic acid and derivatives thereof; mercaptoethanol, mercaptopropanol, mercaptobutanol Chain transfer agents having a hydroxyl group, such as 1-butanethiol, butyl-3-mercaptopropionate, methyl-3-mercaptopropionate, 2, 2 -(Ethylenedioxy) diethanethiol, ethanethiol, 4-methylbenzenethiol, dodecyl mercaptan, propanethiol, butanethiol, pentanethiol, 1-octanethiol, cyclo Ntanchioru, cyclohexane thiol, thioglycerol, 4,4-thiobisbenzenethiol like.

  A polyfunctional mercaptan-based compound can be used and is not particularly limited. For example, hexane-1,6-dithiol, decane-1,10-dithiol, dimercaptodiethyl ether, dimercaptodiethylsulfide. Aliphatic thiols such as xylylene dimercaptan, 4,4′-dimercaptodiphenyl sulfide, and aromatic thiols such as 1,4-benzenedithiol; ethylene glycol bis (mercaptoacetate), polyethylene glycol bis (mercaptoacetate), Propylene glycol bis (mercaptoacetate), glycerin tris (mercaptoacetate), trimethylolethane tris (mercaptoacetate), trimethylolpropane tris (mercaptoacetate), pentaerythritol Poly (mercaptoacetate) polyhydric alcohols such as rutetrakis (mercaptoacetate) and dipentaerythritol hexakis (mercaptoacetate); ethylene glycol bis (3-mercaptopropionate), polyethylene glycol bis (3-mercaptopropionate) ), Propylene glycol bis (3-mercaptopropionate), glycerin tris (3-mercaptopropionate), trimethylolethane tris (mercaptopropionate), trimethylolpropane tris (3-mercaptopropionate), penta Poly (3-mercaptopropionate) of polyhydric alcohol such as erythritol tetrakis (3-mercaptopropionate), dipentaerythritol hexakis (3-mercaptopropionate) 1,4-bis (3-mercaptobutyryloxy) butane, 1,3,5-tris (3-mercaptobutyloxyethyl) -1,3,5-triazine-2,4,6 ( Poly (mercaptobutyrate) s such as 1H, 3H, 5H) -trione and pentaerythritol tetrakis (3-mercaptobutyrate) can be used.

  Examples of these commercially available products include BMPA, MPM, EHMP, NOMP, MBMP, STMP, TMMP, PEMP, DPMP, and TEMPIC (above, manufactured by Sakai Chemical Industry Co., Ltd.), Karenz MT-PE1, Karenz MT-BD1, And Karenz-NR1 (manufactured by Showa Denko KK).

  Further, examples of the heterocyclic compound having a mercapto group acting as a chain transfer agent include mercapto-4-butyrolactone (also known as 2-mercapto-4-butanolide), 2-mercapto-4-methyl-4-butyrolactone, and 2-mercapto. -4-ethyl-4-butyrolactone, 2-mercapto-4-butyrothiolactone, 2-mercapto-4-butyrolactam, N-methoxy-2-mercapto-4-butyrolactam, N-ethoxy-2-mercapto-4- Butyrolactam, N-methyl-2-mercapto-4-butyrolactam, N-ethyl-2-mercapto-4-butyrolactam, N- (2-methoxy) ethyl-2-mercapto-4-butyrolactam, N- (2-ethoxy) Ethyl-2-mercapto-4-butyrolactam, 2-mercapto-5-va Lolactone, 2-mercapto-5-valerolactam, N-methyl-2-mercapto-5-valerolactam, N-ethyl-2-mercapto-5-valerolactam, N- (2-methoxy) ethyl-2-mercapto- 5-valerolactam, N- (2-ethoxy) ethyl-2-mercapto-5-valerolactam, 2-mercaptobenzothiazole, 2-mercapto-5-methylthio-thiadiazole, 2-mercapto-6-hexanolactam, 2 , 4,6-Trimercapto-s-triazine (manufactured by Sankyo Kasei Co., Ltd .: trade name Disnet F), 2-dibutylamino-4,6-dimercapto-s-triazine (manufactured by Sankyo Chemical Co., Ltd .: trade name Disnet) DB), and 2-anilino-4,6-dimercapto-s-triazine (manufactured by Sankyo Kasei Co., Ltd .: trade name: Gisnet AF).

  In particular, as a heterocyclic compound having a mercapto group that is a chain transfer agent that does not impair the developability of the conductive resin composition, 2-mercaptobenzimidazole, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole (trade names: Accelerator M) manufactured by Kawaguchi Chemical Industry Co., Ltd., 3-mercapto-4-methyl-4H-1,2,4-triazole, 5-methyl-1,3,4-thiadiazole-2-thiol, 1-phenyl-5 Mercapto-1H-tetrazole is preferred. These chain transfer agents can be used alone or in combination of two or more.

(Other additive components)
In the conductive resin composition of the present invention, known and commonly used components such as thickeners, defoaming / leveling agents, coupling agents, antioxidants, rust inhibitors and the like can be appropriately blended as necessary. Of course you can.

(Formation of conductive circuit)
Next, an example of a method for forming a conductive circuit using the conductive resin composition according to the present invention will be described.
With respect to the conductive resin composition of the present invention, a machine such as a three-roll roll or a blender is used for kneading and dispersing the above-described essential components and optional components.
The conductive resin composition thus dispersed is applied onto the substrate by an appropriate application method such as a screen printing method, a bar coater, or a blade coater. Next, in order to obtain dryness to the touch, the organic solvent is removed by drying at a temperature at which the carboxyl group-containing resin is not thermally decomposed, for example, about 60 to 120 ° C. for about 5 to 40 minutes in a hot air circulation drying oven, a far infrared drying oven or the like. Evaporate to obtain a tack-free coating.

  Note that the conductive resin composition can be formed into a film in advance, and in this case, the film may be laminated on the substrate.

Next, contact exposure or non-contact exposure is performed using a negative mask having a predetermined exposure pattern. As the exposure light source, a halogen lamp, a high-pressure mercury lamp, a laser beam, a metal halide lamp, a black lamp, an electrodeless lamp, or the like is used. As the exposure amount, the integrated light amount can be a low light amount of 200 mJ / cm ² or less. In addition, you may form a pattern in a coating film with a laser direct imaging apparatus, without using a mask.

  Next, the coating film is formed into a pattern by development such as spraying or dipping. Developers include aqueous alkali metal solutions such as sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate and sodium silicate, and aqueous amine solutions such as monoethanolamine, diethanolamine and triethanolamine, especially about 1.5% by mass or less. A dilute alkaline aqueous solution having a concentration of 1 is preferably used, as long as the carboxyl group of the carboxyl group-containing resin in the conductive resin composition is saponified and the uncured part (unexposed part) is removed, as described above. The developer is not limited to such a developer. Moreover, it is preferable to perform washing with water and acid neutralization in order to remove an unnecessary developer after development.

  Then, the obtained conductive pattern film is dried at a temperature at which the carboxyl group-containing resin is not thermally decomposed. Thus, a conductive circuit having a low resistance and a fine conductive pattern film can be formed. The drying temperature is preferably 150 ° C. or lower, more preferably 140 ° C. or lower, and even more preferably 130 ° C. or lower.

  In these steps, since baking is not performed at a high temperature of 500 ° C., a resin base material (film material) having no heat resistance can be used as the base material. Specifically, as a resin base material, for example, polyimide, polyester resin, polyethersulfone (PES), polystyrene (PS), polymethyl methacrylate (PMMA), polycarbonate (PC), polyamide (PA) , Polypropylene (PP), polyphenylene oxide (PPO), and the like, and a polyester-based resin can be preferably used. A glass substrate or the like may be used.

The present invention will be specifically described below based on examples. However, the present invention is not limited to these examples.
(Compounding ingredients)
[Carboxyl group-containing resin]
Synthesis example 1
A flask equipped with a thermometer, a stirrer, a dropping funnel, and a reflux condenser is charged with methyl methacrylate and methacrylic acid in a molar ratio of 0.87: 0.13, dipropylene glycol monomethyl ether as a solvent, and azobis as a catalyst. Isobutyronitrile was added and stirred at 80 ° C. for 6 hours under a nitrogen atmosphere to obtain a carboxyl group-containing resin solution. This carboxyl group-containing resin had a mass average molecular weight of about 10,000 and an acid value of 74 mgKOH / g. In addition, the mass average molecular weight of the obtained carboxyl group-containing resin was obtained by using Shimadzu Corporation pump LC-6AD and Showa Denko Co., Ltd. column Shodex (registered trademark) KF-804, KF-803, and KF-802. The measurement was performed by high performance liquid chromatography connected to a triplet. Hereinafter, this carboxyl group-containing resin solution is referred to as A-1 varnish. This carboxyl group-containing resin does not contain a double bond and does not contain an aromatic ring.

[Conductive powder]
Spherical conductive powder: Ag powder (maximum particle size 30 μm or less, average particle size 2 μm (SEM)))
[Multifunctional acrylate monomer]
Bifunctional (meth) acrylate monomer: Trade name; KAYARAD HX-220 (manufactured by Nippon Kayaku Co., Ltd.)
Tetrafunctional (meth) acrylate monomer: Trade name; NK Oligo U-4HA (manufactured by Shin-Nakamura Chemical Co., Ltd.)
[Photopolymerization initiator]
Product Name: IRGACURE 379EG (BASF Japan), 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone
[Block isocyanate]
Product name 7982 (manufactured by Baxenden) Isocyanate HDI trimer Blocking agent Dimethyl pyrazole
[Example organic acid]
Note 1 (Example 1): 2'2-thiodiacetic acid; aliphatic dicarboxylic acid, manufactured by Kanto Chemical Co., Ltd. Note 2 (Example 2): aliphatic dicarboxylic acid (bifunctional monomer), Kanto Chemical Co., Inc. Note 3: Citric acid; aliphatic tricarboxylic acid,
Note 4: 1,2,3,4-butanetetracarboxylic acid; aliphatic tetracarboxylic acid, manufactured by Kanto Chemical Co., Ltd. Note 5: 1,2,3,4,5,6-cyclohexanehexacarboxylic acid; aliphatic Hexacarboxylic acid, manufactured by Kanto Chemical Co., Ltd. [Comparative Example Organic Acid]
Note 6: pyruvic acid; aliphatic monocarboxylic acid, manufactured by Kanto Chemical Co., Ltd. Note 7: salicylic acid; aromatic monocarboxylic acid, manufactured by Kanto Chemical Co., Ltd. Note 8: trimellitic acid; aromatic tricarboxylic acid, Kanto [Dispersant] manufactured by Kagakusha
Product name DISPERBYK-111 (by Big Chemie Japan)
(Evaluation method)
Specimen creation:
Each conductive resin composition for evaluation is applied on the entire surface of a polyester resin substrate using a 300 mesh polyester screen, and then dried in a hot air circulation drying oven at 80 ° C. for 30 minutes to touch. A coating film having good drying property was formed. Then, using a high-pressure mercury lamp as a light source, through a negative mask, the integrated light quantity (step tablet 5 stages of exposure amount) on the conductive resin composition after the patterned exposure so that 200 mJ / cm ² or 200 mJ / cm ² Then, development was performed using a 0.4% by mass Na ₂ CO ₃ aqueous solution having a liquid temperature of 30 ° C., followed by washing with water. Finally, it was dried at 140 ° C. for 30 minutes to prepare a test piece on which a conductive pattern film was formed.

Development time: Visually determined the time from when the developer started to contact the dried coating film until the coating film was completely dissolved: Evaluation of the minimum line width of the test piece prepared by the above method did.

In the minimum line, a sample having no defect was evaluated as “good”.

Adjustment of exposure amount: Sensitivity was determined using Step Tablet Kodak No. 2, and based on this evaluation, the exposure amount of 5 steps of Step Tablets was adjusted so that the photocurability was constant.

Specific Resistance Value: A 4 mm × 10 cm pattern was formed by the above method, and the specific resistance value was calculated by measuring the resistance value and film thickness.

Adhesiveness: Pattern formation of L / S = 30/30 um was performed, cellotape (registered trademark) peel was performed, and no defect was evaluated as “good”. Those with defects were evaluated as “bad”.

Coating film strength: L / S = 30 / 30um pattern was formed, and a load of 750g was applied using a pencil hardness tester, which is an apparatus described in JIS K5600-5-4, perpendicular to the side of the line. A sample that was not broken when scratched was evaluated as “good”. Those with defects were evaluated as “bad”. The pencil used was Mitsubishi High Uni (Mitsubishi Pencil Co., Ltd., hardness: 3H).

(Test results)
The experimental conditions and evaluation results of Examples 1 to 5 included in the scope of the present invention and Comparative Examples 1 to 4 deviating from the scope of the present invention (not containing an organic acid or containing an organic acid not included in the present invention) These are summarized in Table 1 and Table 2 below.

  From Examples 1 to 5, the conductive resin composition according to the present invention can be applied to a heat-sensitive substrate and can ensure excellent conductivity and resolution. In addition to the excellent adhesion, it was confirmed that a conductive resin composition having a low specific resistance can be obtained.

  On the other hand, in Comparative Example 1 in which no organic acid is blended, the developability is lowered, and components other than the conductive component remain from the coating film having good developability, so that the specific resistance value is not lowered. It was. Further, in Comparative Example 2, an organic acid deviating from the present invention is blended. However, since there is no effect as a development aid and developability is not improved, the specific resistance value does not decrease for the same reason as in Comparative Example 1. It was. Since the organic acid of Comparative Example 3 also has no effect as a development aid and does not improve developability, the specific resistance value did not decrease for the same reason as in Comparative Examples 1 and 2. Furthermore, the presence of aromatics inhibits light transmission, and as a result, even if the exposure is increased, the conductive component is not separated and the specific resistance value does not decrease because it does not cause sufficient curing shrinkage unlike non-aromatics. It was. Since the organic acid of Comparative Example 4 also inhibits light transmission due to the presence of aromatics, even if the exposure amount is increased, it does not undergo sufficient curing shrinkage as in the case of non-aromatics, so the specific resistance value decreases. There wasn't.

Claims (12)

  A conductive resin comprising a carboxyl group-containing resin, a conductive powder, a polyfunctional acrylate monomer, a photopolymerization initiator, a blocked isocyanate, and an organic acid having no aromatic ring and having two or more carboxyl groups Composition.   The conductive resin composition according to claim 1, wherein the polyfunctional acrylate monomer is a tetrafunctional acrylate monomer. The conductive resin composition according to claim 2, wherein the tetrafunctional acrylate monomer is an acrylate monomer represented by the following chemical formula (I).

In formula (I),
X ¹ represents a group containing an acryloyloxy group.
X ² represents a group containing a methacryloyloxy group.
X ³ and X ⁴ each independently represent a group containing an acryloyloxy group or a group containing a methacryloyloxy group. However, at least one of X ³ and X ⁴ represents a group containing a methacryloyloxy group.
L ¹ and L ² are each independently

Represents.
* Represents a binding site with Z.
Z represents a divalent linking group. L ₁ and L ₂ in the general formula (I) are

(In formula (III), * represents a binding site with Z.)
The conductive resin composition of Claim 3 represented by these. The conductive resin composition according to claim 3, wherein the tetrafunctional acrylate monomer represented by the general formula (I) is represented by the following formula (IV).

In formula (IV),
Z ¹ represents an alkylene group.
R ¹ represents a hydrogen atom.
R ² represents a methyl group.
R ³ and R ⁴ each independently represents a hydrogen atom or a methyl group. However, at least one of R ³ and R ⁴ represents a methyl group.   The conductive resin composition according to claim 1, wherein the photopolymerization initiator includes an oxime ester photopolymerization initiator.   The conductive resin composition according to any one of claims 1 to 6, wherein the carboxyl group-containing resin does not contain a double bond.   The conductive resin composition according to claim 7, wherein the carboxyl group-containing resin not containing a double bond further has no aromatic ring.   The organic acid having no aromatic ring and having two or more carboxyl groups includes one or more organic acids selected from the group of dicarboxylic acids, tricarboxylic acids, and tetracarboxylic acids. The conductive resin composition according to any one of claims 1 to 8.   The conductive resin composition according to any one of claims 1 to 9, wherein the blocked isocyanate has a dissociation temperature of 100C to 140C.   The conductive resin composition according to any one of claims 1 to 10, wherein the conductive resin composition is applied to a substrate that is a film material and dried to form a conductive circuit.   The conductive circuit formed by apply | coating and drying the conductive resin composition of any one of Claims 1-11 on a base material.