JP2013136727A - Conductive resin composition and conductive circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a conductive resin composition applicable to substrates vulnerable to heat, and capable of securing excellent conductivity; and a conductive circuit formed by using the conductive resin composition.SOLUTION: This conductive resin composition includes a carboxy group-containing resin containing no double bond, a conductive powder, at least any one among 2 to 4 functional groups-containing acrylate monomers, and a photopolymerization initiator. The conductive circuit is formed by using this conductive resin composition.

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.

    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.

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.

  In order to solve the above problems, the present invention provides at least one of a carboxyl group-containing resin not containing a double bond, a conductive powder, an acrylate monomer having 2 to 4 functional groups, and initiation of photopolymerization. Provided is a conductive resin composition containing an agent, and a conductive circuit formed on the substrate using the conductive resin composition.

  According to the present invention, it is possible to provide a conductive resin composition that can be applied to a heat-sensitive substrate and can ensure excellent conductivity, and a conductive circuit formed using the conductive resin composition. .

  The conductive resin composition of the present invention has the greatest feature in that a carboxyl group-containing resin not containing a double bond is used, and the number of functional groups of the acrylate monomer is specified as 2 to 4.

  The reason why the number of functional groups of the acrylate monomer is specified as 2 to 4 is as follows. By setting the number of functional groups of the acrylate monomer to 2 or more, the photoreactivity is improved and the resolution is excellent. In addition, since the number of functional groups is 4 or less, the reaction proceeds faster between the functional groups of other acrylate monomers and the functional groups than the functional groups of the acrylate monomers react with each other during photocuring. To do. Thereby, since an intermolecular bond is formed between a plurality of acrylate monomers, the conductive resin composition is 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 decreases.

  On the other hand, when the number of functional groups of the acrylate monomer is 1, resolution is not obtained because of poor photoreactivity. On the other hand, when the number of functional groups of the acrylate monomer is 5 or more, the functional groups react preferentially in the molecule of the acrylate monomer, so that an intermolecular bond is hardly formed. As a result, since the conductive resin composition does not sufficiently cure and shrink, it is considered that the conductive powder does not become dense and the specific resistance value of the conductive pattern film is unlikely to decrease.

  Therefore, the conductive resin composition of the present invention has excellent conductivity only by treating at a temperature lower than 500 ° C. without treatment at a temperature at which the carboxyl group-containing resin containing no double bond is thermally decomposed. Demonstrate sex. For this reason, the conductive resin composition of the present invention can be applied to a heat-sensitive substrate. In addition, the conductive resin composition of the present invention can ensure excellent resolution.

(Components blended in the conductive resin composition)
(Carboxyl group-containing resin not containing double bond)
As the carboxyl group-containing resin, a carboxyl group-containing resin containing no double bond is used. Since a carboxyl group-containing resin not containing a double bond (hereinafter sometimes abbreviated as “carboxyl group-containing resin”) does not react with an 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 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 making it.
(5) a carboxyl group-containing resin obtained by reacting a hydroxyl group-containing polymer with a polybasic acid anhydride,
However, it is not limited to these.
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 are not distinguished from each other by dissolution and peeling with a developer, which makes it difficult to draw a normal conductive pattern.

  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.

(2-4 functional acrylate monomers)
As the acrylate monomer, at least one of acrylic monomers having 2 to 4 functional groups is used.
Specific examples of acrylic monomers having 2 to 4 functional groups are shown below.
(Bifunctional acrylate monomer)
Examples of the bifunctional (meth) acrylate monomer include 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, 1,9-nonanediol di (meth) acrylate, and tricyclode Candimethanol (meth) acrylate, bisphenol A (poly) ethoxydi (meth) acrylate, bisphenol A (poly) propoxy di (meth) acrylate, bisphenol F (poly) ethoxydi (meth) acrylate, ethylene glycol di (meth) acrylate, (poly ) Di (meth) acrylate of ε-caprolactone adduct of ethylene glycol di (meth) acrylate hydroxypivalate neopentyl glycol (eg, Nippon Kayaku Co., Ltd., KAYARAD HX-220, HX-620, etc.) Rukoto can.

(Trifunctional acrylate monomer)
Examples of the trifunctional acrylate monomer include triacrylates or trimethacrylates of trihydric or higher polyhydric alcohols such as trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate and the like.

(Acrylic monomer with 4 functional groups)
Examples of tetrafunctional acrylate monomers include pentaerythritol tetraacrylate and pentaerythritol tetramethacrylate.

As the tetrafunctional acrylate monomer, a tetrafunctional urethane acrylate monomer or ester acrylate described in chemical formulas (I) and (II) is preferable.

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.).

  Among these acrylate monomers having 2 to 4 functional groups, the acrylate monomers having 4 functional groups represented by the formula (I) are preferable. 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 an acrylate monomer having 2 to 4 functional groups is not particularly limited, but is 10 to 100 parts by mass, more preferably 20 to 80 parts by mass with respect to 100 parts by mass of the carboxyl group-containing resin. Is appropriate. 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.
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. Other components exemplified below can be included together with at least any one of powder, acrylate monomer having 2 to 4 functional groups, and a photopolymerization initiator.

(Organic acid)
As the organic acid, an organic acid having no aromatic ring is preferable. By blending an organic acid not having an aromatic ring, the light absorption of the organic acid itself is suppressed, the photoreactivity of the acrylate monomer having 2 to 4 functional groups is relatively improved, and excellent resolution is obtained. be able to.

  Specific examples of organic acids include 2,2′-thiodiacetic acid, adipic acid, isobutyric acid, formic acid, citric acid, glutaric acid, acetic acid, oxalic acid, tartaric acid, lactic acid, pyruvic acid, malonic acid, butyric acid, Carboxylic acids such as malic acid, salicylic acid, benzoic acid, phenylacetic acid, acrylic acid, maleic acid, fumaric acid, crotonic acid; dibutyl phosphite, butyl phosphite, dimethyl phosphite, methyl phosphite, phosphorous acid Mono- or diesters of phosphorous acid such as dipropyl, propyl phosphite, diphenyl phosphite, phenyl phosphite, diisopropyl phosphite, isopropyl phosphite, phosphorous acid-n-methyl-2-ethylhexyl; phosphorus Dibutyl phosphate, butyl phosphate, dimethyl phosphate, methyl phosphate, dipropyl phosphate, propyl phosphate, diphenyl phosphate, phenyl phosphate, Examples thereof include mono- or diesters of phosphoric acid such as diisopropyl phosphate, isopropyl phosphate, and phosphoric acid-n-butyl-2-ethylhexyl. As the organic acid, 2,2'-thiodiacetic acid is preferable.

  The blending amount of the organic acid is preferably in the range of 0.1 to 5 parts by mass with respect to 100 parts by mass of the conductive powder. 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.

(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, DIC Corporation Epicron 840, Epicron 850, Epicron 1050, Epicron 2055, Etototo YD-011, manufactured by Tohto Kasei Co., Ltd. YD-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, BASF Japan Araldide 6071, Araldide 6084, Araldide GY250, Araldide GY260, Sumitomo Chemical Co., Ltd. Sumi-epoxy ESA-011, ESA-014, ELA-115, ELA-128, Asahi Kasei Kogyo Co., Ltd. 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 Japan Epoxy Resin, 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, Araldide 8011 manufactured by BASF Japan, Sumi-epoxy ESB-400 and ESB-700 manufactured by Sumitomo Chemical Co., Ltd. E. R. 711, A.I. E. R. Brominated epoxy resins such as 714 (all trade names); JER152 and JER154 manufactured by Japan Epoxy Resin, and D.C. E. N. 431, D.D. E. N. 438, Epicron N-730, Epicron N-770, Epicron N-865, Etototo YDCN-701, YDCN-704, Ardfide ECN1235, Araldide ECN1273, Araldide ECN1299, Araldide manufactured by BASF Japan XPY307, Nippon Kayaku Co., Ltd. EPPN-201, EOCN-1025, EOCN-1020, EOCN-104S, RE-306, Sumitomo Chemical Co., Ltd. Sumi-epoxy ESCN-195X, ESCN-220, manufactured by Asahi Kasei Kogyo Co., Ltd. A. E. R. Novolak type epoxy resins such as ECN-235, ECN-299, etc. (all trade names); Epicron 830 manufactured by DIC, JER807 manufactured by Japan Epoxy Resin, Epotote YDF-170, YDF-175 manufactured by Toto Kasei Co., Ltd., YDF- 2004, Bisphenol F type epoxy resin such as Araldide XPY306 manufactured by BASF Japan (all trade names); Hydrogenated bisphenol A such as Epototo ST-2004, ST-2007, ST-3000 (trade names) manufactured by Tohto Kasei Co., Ltd. Type epoxy resin: JER604 manufactured by Japan Epoxy Resin Co., Epototo YH-434 manufactured by Toto Kasei Co., Ltd., Araldide MY720 manufactured by BASF Japan, Sumi-Epoxy ELM-120 manufactured by Sumitomo Chemical Co., Ltd. (all trade names) Glycidylamine type epoxy resin; BA Hydantoin type epoxy resin such as Araldide CY-350 (trade name) manufactured by F Japan; Celoxide 2021 manufactured by Daicel Chemical Industries; alicyclic epoxy such as Araldide CY175 and CY179 manufactured by BASF Japan Resin; YL-933 manufactured by Japan Epoxy Resin Co., Ltd. E. N. , EPPN-501, EPPN-502, etc. (all trade names) trihydroxyphenylmethane type epoxy resin; Japan Epoxy Resin YL-6056, YX-4000, YL-6121 (all trade names), etc. Bisphenol S type epoxy resins such as xylenol type or biphenol type epoxy resins or mixtures thereof; 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 resins such as JER157S (trade name) manufactured by Epoxy Resin; Tetraphenylolethane type epoxy such as JERYL-931 manufactured by Japan Epoxy Resin, Araldide 163 manufactured by BASF Japan, etc. (all are trade names) Resin; manufactured by BASF Japan Heterocyclic epoxy resins such as Rudide PT810, TEPIC manufactured by Nissan Chemical Industries (both trade names); Diglycidyl phthalate resins such as Bremer DGT manufactured by NOF Corporation; Tetraglycidyl Xyleno such as ZX-1063 manufactured by Tohto Kasei Co., Ltd. Iruethane resin; Nippon Steel Chemical Co., Ltd. ESN-190, ESN-360, DIC Corporation HP-4032, EXA-4750, EXA-4700 and other naphthalene group-containing epoxy resins; DIC Corporation HP-7200, HP-7200H, etc. Epoxy resin having dicyclopentadiene skeleton; Epoxy resin of glycidyl methacrylate copolymer such as CP-50S, CP-50M manufactured by NOF Corporation; Copolymer epoxy resin of cyclohexyl maleimide and glycidyl methacrylate; Epoxy-modified polybutadiene rubber derivative (Example If manufactured by Daicel Chemical Industries, PB-3600, etc.), CTBN modified epoxy resin (e.g., Tohto Kasei Co. YR-102, YR-450, etc.) and others as mentioned, is not limited thereto. 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 Japan Epoxy Resins. 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 the isocyanate blocking agent include phenol 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 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 containing no double bond]
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)))
Needle-shaped conductive powder: Ag powder (maximum particle size 30 μm or less, average particle size 2 μm (SEM)))
[Acrylate monomer]
Monofunctional acrylate monomer: Trade name; Phenol EO-modified acrylate Bifunctional acrylate monomer: Trade name; KAYARAD HX-220 (manufactured by Nippon Kayaku Co., Ltd.)
Trifunctional acrylate monomer: Trade name; Aronix M-350 (manufactured by Toa Gosei Co., Ltd.)
Tetrafunctional acrylate monomer: Trade name; NK Oligo U-4HA (manufactured by Shin-Nakamura)
Hexafunctional acrylate monomer: Dipentaerythritol hexaacrylate (Nippon Kayaku Co., Ltd.)
[Photopolymerization initiator]
Product name: IRGACURE 379EG (manufactured by BASF Japan Ltd.), 2- (dimethylamino) -2-[(4-methylphenyl) methyl] -1- [4- (4-morpholinyl) phenyl] -1-butanone
[Organic acid]
2,2'-thiodiacetic acid
[Dispersant]
Product name DISPERBYK-111 (by Big Chemie Japan)
[Description of Examples and Comparative Examples]
As shown in Table 1 below, Examples 1 to 11 and 18 are blended with a tetrafunctional acrylate monomer, and Examples 12, 14, and 16 are blended with a bifunctional acrylate monomer, Examples 13, 15, and 17 are blends of trifunctional acrylate monomers. Among these examples, Examples 1 to 3, 8 to 10, 12, and 13 are added by changing the blending amount of the spherical conductive powder (Ag). In Examples 4 to 6, 11, 14, and 15, the needle-like conductive powder (Ag) was added in different amounts. Examples 7 and 16 to 18 are prepared by mixing spherical and needle-shaped conductive powders.

In Examples 8 to 11, the blending amount of the photopolymerization initiator was increased with respect to the blending amount of the photopolymerization initiator of Examples 1 to 4, and added.

  On the other hand, as shown in Table 2 below, Comparative Examples 1, 4, 6, and 8 use monofunctional acrylate monomers as acrylate monomers while changing their blending amounts. In Comparative Examples 2, 3, 5, and 7, hexafunctional acrylate monomers were used as acrylate monomers while changing the blending amount.

(Evaluation method)
With respect to each of the conductive resin compositions of Examples 1 to 18 and Comparative Examples 1 to 8 thus obtained, the resolution and specific resistance value were evaluated. The evaluation method is as follows.
Specimen creation:
Each conductive resin composition for evaluation was applied to 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 90 ° C. for 30 minutes to touch. A coating film having good drying property was formed. Thereafter, using a high-pressure mercury lamp as a light source, pattern exposure was performed through a negative mask so that the integrated light amount on the conductive resin composition was 200 mJ / cm ^2, and then 0.4 mass% Na ₂ CO at a liquid temperature of 30 ° C. then developed using a ₃ solution, and washed with water. Finally, it was dried at 130 ° C. for 30 minutes to prepare a test piece on which a conductive pattern film was formed.

Resolution: The minimum line width of the test piece prepared by the above method was evaluated.

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

The blending components, blending amounts, resolution, and specific resistance values of Examples 1 to 18 and Comparative Examples 1 to 8 are collectively shown in Tables 1 and 2. In Tables 1 and 2, “solid content of A-1 varnish” is a mass obtained by removing the solvent from the A-1 varnish.

In the conductive resin compositions according to Examples 1 to 18, a high-definition conductive pattern film with L / S = 30/30 μm or less can be formed even with exposure at a low exposure amount of 200 mJ / cm ² or less. all right. Further, without thermal decomposition of the carboxyl group-containing resin, specific resistance (Ω · cm) it was also found to be able to form a 5.00 ^-4 or less of the conductive pattern film. Therefore, it was found that the conductive resin composition of the present invention can be applied to a heat-sensitive substrate and can ensure excellent conductivity and resolution.

Claims (5)

  A conductive resin composition comprising: a carboxyl group-containing resin not containing a double bond; conductive powder; at least one of acrylate monomers having 2 to 4 functional groups; and a photopolymerization initiator. .   The conductive resin composition according to claim 1, wherein the carboxyl group-containing resin further does not contain an aromatic ring.   The conductive resin composition according to claim 1, wherein the photopolymerization initiator is an oxime ester type or an acetophenone type.   Furthermore, the organic acid which does not have an aromatic ring is included, The conductive resin composition in any one of Claims 1-3 characterized by the above-mentioned.   The electrically conductive circuit formed using the conductive resin composition in any one of Claims 1-4 on a base material.