TW201432723A - Conductive paste - Google Patents

Abstract

A conductive paste being an embodiment of the present invention contains metal microparticles (A), a resin binding agent (B), and an organic solvent (C), and also contains an organic monocarboxylic acid metal salt (D1), a diketone chelating agent (D2), and an aromatic compound (D3) that is indicated by general formula (1). This conductive paste is capable of forming an electrode having excellent conductive stability over time, and/or has excellent printing characteristics.

Description

Conductive paste

The present invention relates to conductive pastes.

The conductive paste is a material for forming a fine electrode and a dot-shaped fine electrode, for example, on a printed circuit board. Conventionally, a silver paste is recommended because of high conductivity.

However, the coating film obtained from the conductive silver paste is liable to undergo ion migration. Also, the silver particles are relatively expensive. In addition, in the industry, conductive pastes using low-cost copper particles have also begun to be used.

The conductive paste using copper particles is a composition obtained by kneading copper particles, a resin adhesive, and an organic solvent by a kneader and a three-roller. Further, it may be applied to the substrate in such a manner as to have a desired wiring pattern, and then dried, hardened or fired to form a desired circuit and electrode.

However, the circuit and the electrode obtained from the conductive copper paste tend to increase in volume resistivity over time, and do not exhibit long-term continuous conductivity. This is because the copper particles are easily oxidized and a thick oxide film is formed on the surface.

As a means for achieving electrical conductivity stability over time of a conductive copper paste, Patent Document 1 proposes to add an alkyl benzoic acid, a hydroquinone, an aminophenol, etc. as an additive in a conductive copper paste. The method of the agent, but its effect has not yet reached the high standard of meeting the needs of the industry.

As another example, it is disclosed that palladium acts as a catalyst in the state in which palladium and copper formate coexist, and the temperature at which the resin is used as a substrate at a low temperature lower than the thermal decomposition temperature of copper formate itself is 130 to 140 ° C. The technique of obtaining a copper film at a temperature (license document 2).

However, in this method, since the coarse composite particles prepared by the liquid phase method are directly used, it is difficult to obtain uniformity as a printing ink. Further, there is a high possibility that the pattern cannot be formed by the printing method. Further, there is also a problem that copper powder is simultaneously formed during film formation, and the material efficiency is low.

[Previous Technical Literature]

[license literature]

[Patent Document 1] Japanese Patent Publication No. 5-135619

[Patent Document 2] JP-A-6-93455

[Summary of the Invention]

According to the present invention, it is possible to provide an electrode having superior conductivity and electrical conductivity and/or a conductive paste having excellent printing characteristics over time, thereby solving the above-mentioned at least one technical problem.

The inventors of the present invention repeated the results of intensive research and analysis and found that at least a part of the above problems can be solved by including the conductive paste with three specific materials.

A conductive paste of the present invention comprises: (A) metal fine particles, (B) a resin adhesive, and (C) an organic solvent, and further comprises: (D1) an organic monocarboxylic acid A metal salt, a (D2) diketone-based chelating agent, and (D3) an aromatic compound represented by the following general formula (Chemical Formula 1).

(In Chemical Formula 1, R ¹ , R ² , R ³ , R ⁴ and R ^{5 each} represent hydrogen, a hydroxyl group, an alkyl group, a carboxylic acid group or an amine group. Further, n is 0 or 1, and when n is 1, A is Indicates an alkylene group. Further, X represents a carboxylic acid group or a fluorenyl group.

Although a clear mechanism has not been clarified, according to the conductive paste, a metal complex of the component (D2) can be produced by the ligand exchange reaction between the above (D1) component and the above (D2) component. This is because the metal ion of the organic monocarboxylic acid metal salt of the (D1) component which is formed by the organic monocarboxylic acid ion and the metal ion is in conformity with the (D2) component of the bidentate ligand. The object can exist more stably from the viewpoint of the entropy effect.

Further, the oxide film formed on the surface of the component (A) is reduced by the reduction of the organic monocarboxylic acid derived from the (D1) component as a result of the ligand exchange reaction. As a result, it is considered that the conductivity originally possessed by the component (A) is restored. Further, the metal complex of the component (D2) produced as a result of the above-described ligand exchange reaction is decomposed under heating. As a result, the fine particles of the metal particles generated by the exchange of the (D1) component, that is, the ligand exchange reaction between the (D1) component and the (D2) component, are precipitated on the surface of the (A) component and in the continuous phase. . On behalf of In one example, the metal-generated particles (metal particles) derived from one of the (D1) components become one or all of the surface of the (A) component. However, since the metal particles do not have an oxide film on the surface, they are excellent in conductivity. Therefore, with this conductive paste, it is possible to obtain a coating film having a small volume resistivity which is not only at room temperature and at a high temperature, and which is low in time (hereinafter, "because the volume resistivity passes over time" The low amplitude is small, and the change in conductivity over time is small, which is simply described as "time-dependent conductivity stability"). Moreover, since the conductive paste has good screen printing suitability, fine wiring and minute electrodes can be formed. Further, with this conductive paste, it is possible to obtain a material having a temporal conductivity stability equivalent to that of a silver paste.

According to the conductive paste of the present invention, it is possible to obtain a coating film having a small volume resistivity which is not only at room temperature but also at a high temperature. Moreover, since the conductive paste has good screen printing suitability, fine wiring and minute electrodes can be formed.

X‧‧‧(A) ingredients

Y‧‧‧fine particles

Fig. 1 is an electron micrograph showing a state in which metal ions of the component (D1) are precipitated as fine particles on the surface of the component (A) and the continuous phase in the first embodiment of the present invention.

Fig. 2 is an electron microscope photograph corresponding to Fig. 1 shown in Comparative Example 2.

Hereinafter, an example of a conductive paste of an embodiment of the present invention will be described. To elaborate.

<First embodiment>

The conductive paste of the present embodiment includes (A) metal fine particles (hereinafter referred to as (A) component), (B) a resin adhesive (hereinafter referred to as (B) component), and (C) an organic solvent (hereinafter referred to as C) Ingredients) conductive paste. Further, the conductive paste of the present embodiment further comprises (D1) an organic monocarboxylic acid metal salt (hereinafter referred to as (D1) component), and (D2) a diketone chelating agent (hereinafter referred to as (D2) component), (D3) An aromatic compound (hereinafter referred to as (D3) component) represented by the following general formula (Chemical Formula 1). (A) component, (B) component, (C) component, (D1) component, (D2) component, and (D3) component are mixed by a known means (for example, a mixing step of a three-roller machine, etc.) The conductive paste of this embodiment is manufactured. Further, in the present embodiment, the above (D1), (D2), and (D3) are used as additives. Further, in the present embodiment, copper particles are typically used as the component (A).

Although the example of the component (A) of the present embodiment is copper particles, the present embodiment is not limited to copper particles. For example, the component (A) of the present embodiment is selected from the group consisting of copper, cobalt, iron, zinc, aluminum, titanium, vanadium, manganese, zirconium, molybdenum, indium, lanthanum, cerium, tungsten, and at least one of the foregoing metals. The metal fine particles composed of at least one of the groups of the alloys of the alloy can achieve the same or at least a portion of the effects of the present embodiment. In addition, the average primary particle diameter of the component (A) is not particularly limited, but is preferably an angle of 0.05 μm or more and 50 μm or less from the viewpoint of temporal conductivity stability and screen printing suitability. Further, it is a more appropriate aspect to the extent of 0.05 μm or more and 30 μm or less. Moreover, the average primary particle diameter is a laser diffraction. The measured value of the scattering method. Further, the component (A) may be a spherical, slightly spherical, flat or dendritic microparticle as a representative example. But by The dendritic (A) component is particularly excellent from the viewpoint of electrical conductivity stability.

Further, the type of the copper particles used as the component (A) of the present embodiment is not particularly limited. Various known copper particles can be used as the component (A) without particular limitation. Further, the copper particles also contain copper alloy particles. Representative examples of metals other than copper constituting the copper alloy are cobalt, iron, zinc, aluminum, titanium, vanadium, manganese, zirconium, molybdenum, indium, bismuth, antimony, tungsten, and the like.

An example of the component (B) of this embodiment is a resin adhesive which can be used for a conductive paste. Various known thermosetting resins or thermoplastic resins can be used as the component (B). Specific examples of the component (B) are at least one selected from the group consisting of a phenol resin, a polyester resin, an epoxy resin, a polyurethane resin, and an acrylic resin.

Here, a representative example of the above phenol resin is a novolak type phenol resin or a solubilized phenol resin. The above phenol resin is not particularly limited. Further, representative examples of the phenolic aldehydes which are raw materials are carbolic acid, cresol, amyl phenol, bisphenol A, butyl phenol, octyl phenol, nonyl phenol, and dodecyl phenol. Further, representative examples of the formaldehyde are fumarin, paraformaldehyde and the like.

Further, a representative example of the above polyester resin is a compound in which an acid component is reacted with an ethylene glycol component.

Here, representative examples of the acid component are aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, 2,6-naphthalenedicarboxylic acid, or succinic acid, adipic acid, and stilbene. An aliphatic dicarboxylic acid such as an acid, azelaic acid or dodecane dicarboxylic acid, or 1,4-cyclohexanedicarboxylic acid, hexahydrophthalic anhydride or 1,1'-bicyclohexane-4,4 An alicyclic dicarboxylic acid such as a dicarboxylic acid or a 2,6-decahydronaphthalene dicarboxylic acid, or a trivalent or higher polycarboxylic acid such as trimellitic anhydride or pyromellitic dianhydride.

Further, representative examples of the above diol component are ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propanediol, 2-methyl-1,3-propanediol, 1, Aliphatic binary such as 3-butanediol, neopentyl glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, dipropylene glycol Alcohol, or alicyclic diol such as 1,4-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, hydrogenated bisphenol A, hydrogenated bisphenol F, Or glycerol, trimethylolpropane, trimethylolethane, diglycerol, triglycerol, 1,2,6-hexanetriol, pentaerythritol, dipentaerythritol, dipentaerythritol, sorbitol, nectar A trivalent or higher polyhydric alcohol such as an alcohol.

Further, the physical properties of the polyester resin are not particularly limited. Typically, the hydroxyl value is 3 KOHmg/g or more, 200 KOHmg/g or less, and the acid value is 0.1 KOHmg/g or more and 50 KOHmg/g or less.

Representative examples of the above epoxy resin are a bisphenol type epoxy resin, a hydride of a bisphenol type epoxy resin, or a reaction of a novolak type epoxy resin or a cresol novolak resin with a haloepoxide. A novolac type epoxy resin, a biphenyl type epoxy resin, or an amine modified resin obtained by reacting each of the above epoxy resins with various known amines, or each of the above epoxy resins and various known amines and polyisocyanates The amine obtained. A urethane-modified resin (refer to Japanese Laid-Open Patent Publication No. 2010-235918) and the like.

Further, representative examples of the above bisphenols are bisphenol A, bisphenol F, bisphenol AD, bisphenol S, tetramethyl bisphenol A, tetramethyl bisphenol F, tetramethyl bisphenol AD, tetramethyl Bisphenol S, tetrabromobisphenol A, tetrachlorobisphenol A, tetrafluorobisphenol A, and the like.

Further, representative examples of the above amines are methylaniline and dimethylbenzene. Amines, cumylamine (isopropylanilide), hexylaniline, mercaptoaniline, dodecylaniline, etc., or aromatic amines, or cyclopentylamine, cyclohexylamine, norbornylamine An alicyclic amine such as methylamine, ethylamine, propylamine, butylamine, hexylamine, octylamine, decylamine, dodecylamine, octadecylamine, twenty An aliphatic amine such as an alkylamine, 2-ethylhexylamine, dimethylamine, diethylamine, dipropylamine, dibutylamine, dipentylamine or diheptylamine, or diethanolamine, Alkanolamines such as diisopropanolamine, di-2-hydroxybutylamine, N-methylethanolamine, N-ethylethanolamine, N-benzylethanolamine, and the like.

Further, representative examples of the above polyisocyanate are 1,5-naphthyl diisocyanate, 4,4'-diphenylmethane diisocyanate, benzylidene diisocyanate, butane-1,4-diisocyanate, and hexamethylene Various aliphatic or alicyclic groups such as bis-isocyanate, 2,2,4-trimethylhexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, Or an aromatic diisocyanate.

Further, representative examples of the above epoxy resin are selected from the group consisting of the above bisphenols and epichlorohydrin (so-called phenoxy resin), amine-modified epoxy resins and amines. At least one of the groups composed of the urethane-modified epoxy resin is preferably from the viewpoint of adhesion to the substrate and/or print suitability.

Representative examples of the above urethane resin are a polymer polyol and a polyisocyanate, and a poly(urea) urethane resin using an amine as a raw material is required. The polymer polyol is a hydroxyl group-containing material (polyester polyol), a polycarbonate polyol, a polyether polyol, or the like in the polyester resin.

Further, representative examples of the above polyisocyanate are butane-1,4-diisocyanate, 1,6-hexamethylene diisocyanate, lysine diisocyanate, 2, 2, 4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, cyclohexane-1,4-diisocyanate, isophorone diisocyanate, dicyclohexylmethane -4,4'-diisocyanate, 1,3-bis(isocyanatemethyl)cyclohexane, 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'- Diphenyldimethylmethane diisocyanate, benzylidene diisocyanate, and the like.

Further, representative examples of the above amines are diamines such as ethylenediamine, propylenediamine, hexamethylenediamine, isophoronediamine, dicyclohexylmethane-4,4-diamine, or n-butylamine. Monoamines such as mono-n-butylamine, diethanolamine, monoethanolamine, alkanolamines such as monoethanolamine and diethanolamine, and the like.

Moreover, as a representative example of the above-mentioned urethane resin, an isocyanate terminal urethane prepolymer obtained by reacting the above polymer polyol and the above polyisocyanate may be used, and chain extension and/or chain cessation may be carried out using the above amine.

Further, a representative example of the above acrylic resin is a product obtained by copolymerizing various acrylic monomers. Representative examples of the monomer are methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, dodecyl (meth)acrylate, Octadecylmethyl methacrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, cyclohexyl (meth)acrylate, (methyl) An alkyl (meth) acrylate such as cyclopentyl acrylate or isobornyl (meth)acrylate, or hydroxymethyl (meth) acrylate, hydroxyethyl (meth) acrylate or 2-(meth) acrylate Hydroxypropyl ester, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, hydroxycyclohexyl (meth)acrylate, 4-(hydroxymethyl)cyclohexyl (meth)acrylate Methyl ester, 4-(hydroxymethyl)cyclohexylmethyl 2-hydroxypropionate, (A Hydroxy (meth) acrylate such as hydroxyphenyl acrylate, or α,β unsaturated carboxylic acid such as acrylic acid, methacrylic acid, crotonic acid, isocrotonic acid, fumaric acid, maleic acid (anhydride), or benzene An aromatic vinyl monomer such as ethylene, α-methylstyrene, t-butylstyrene or dimethylstyrene, or acrylamide, methacrylamide or N-(2-hydroxyethyl)propene oxime Amine, N-(1-methyl-2-hydroxyethyl) acrylamide, (meth) acrylamide, or an unsaturated sulfonic acid, or an aminoalkyl unsaturated monomer, or a polyoxyalkylene Examples of unsaturated monomers, or chlorodecane-based (meth) acrylates, or (poly) decane mono(meth) acrylates, or fluoroalkyl (mono) acrylates, and the like.

Further, in the present embodiment, the above component (B) may be used in combination with other resin adhesives. Specific examples of the other resin adhesive are selected from the group consisting of polyethylene resin, polypropylene resin, polyvinyl chloride resin, polystyrene resin, polyvinyl acetate, polytetrafluoroethylene resin, ABS resin, AS resin, polyamide resin, Polyvinyl acetal resin, polycarbonate resin, modified polyphenylene ether resin, polyethylene terephthalate resin, polybutylene terephthalate resin, cyclic polyolefin resin, polyphenylene sulfide resin, At least one of a group consisting of a polyanthracene resin, a polyether oxime resin, an amorphous polyarylate resin, a liquid crystal polymer resin, a polyetheretherketone resin, and a polyamidoximine resin.

Further, the amount of the component (B) used is not particularly limited. However, from the viewpoint of screen printing suitability and temporal conductivity stability, the amount of the component (B) is preferably 1 part by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the component (A). From the same viewpoint, the above range is preferably 5 parts by mass or more, 25 parts by mass or less, and 10 parts by mass or more and 20 parts or less.

Further, the above component (C) is an organic solvent which can be used for a conductive paste. Agent. Various known organic solvents can be used without particular limitation. Representative examples of (C) are ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-propyl ether, ethylene glycol monoisopropyl ether, ethylene glycol mono-n-butyl ether, diethylene glycol single Methyl ether, diethylene glycol monoethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol monomethyl ether, diethyl ether, ethylene glycol dimethyl ether, ethylene glycol methyl ethyl ether, ethylene Alcohol ethyl ether acetate, diethylene glycol diethyl ether, diethylene glycol monomethyl ether acetate, diethylene glycol monoethyl ether acetate, tetrahydrofuran and other ether alcohols, or methanol, ethanol, isopropanol , non-ether alcohols such as cyclohexanol, ethylene glycol, propylene glycol, 1,4-butanediol, triethylene glycol, ethyl lactate, butyl lactate, diacetone alcohol, rosin alcohol, borneol, Or a ketone solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone or cyclohexanone, or methyl acetate, ethyl acetate, butyl acetate, methyl methoxypropionate or ethyl propionate. An ester solvent such as diethyl oxalate or diethyl malonate, or dichloromethane, 1,2-dichloroethane, 1,4-dichlorobutane, trichloroethane, chlorobenzene or o-dichloro a halogen solvent such as benzene, An aromatic solvent such as hexane, heptane, octane and other aliphatic solvents, or benzene, toluene, xylene and the like, or α- pinene turpentine or (pinene) and other plant-based solvents, propylene carbonate, or the like.

Therefore, at least one selected from the group consisting of the ether alcohol, the non-ether alcohol, the ester solvent, the ketone solvent, the aliphatic solvent, the aromatic solvent, and the plant solvent This is an aspect that can be employed in this embodiment. However, among these, the ether alcohol is preferred from the viewpoint of temporal conductivity stability and/or screen printing suitability.

Further, the amount of the component (C) used is not particularly limited. However, from the viewpoints of handleability, screen printing suitability, and/or time-dependent conductivity stability, the component (C) is 1 part by mass or more and 30 parts by mass with respect to 100 parts by mass of component (A). The degree is lower. From the same viewpoint, the above range is preferably 3 mass parts or more, 20 parts by mass or less, and 5 parts or more and 15 parts or less.

<About additives>

As described above, the conductive paste of the present embodiment is mixed as a component of the conductive paste as the (D1) component, the (D2) component, and the (D3) component as additives. In the present embodiment, the desired temporal stability and/or screen printing suitability are achieved by the interaction of the (D1) component, the (D2) component, and the (D3) component.

Further, although the inventors of the present invention have not determined the reason for obtaining such an effect, it is presumed that the bonding step in the production of the conductive paste of the present embodiment and/or the heating of the conductive paste after screen printing are performed. The following reactions [1] to [3] occur during the drying process.

[1] A metal complex of the component (D2) can be produced by a ligand exchange reaction between the component (D1) and the component (D2). This is because the metal ion of the organic monocarboxylic acid metal salt of the (D1) component formed by the organic monocarboxylic acid ion and the metal ion forms a complex with the (D2) component of the bis ligand ligand, by entropy The effect of the effect can be more stable.

[2] The oxide film formed on the surface of the component (A) is reduced by reduction of an organic monocarboxylic acid derived from the component (D1) produced as a result of the ligand exchange reaction. As a result, it is considered that the conductivity originally possessed by the component (A) is restored.

[3] On the other hand, the metal complex of the (D2) component which is produced as a result of the above-described ligand exchange reaction is decomposed under heating, and the metal ion derived from the released (D1) component (in the present embodiment) As a copper ion) as a fine particle It precipitates on the surface of the component (A) and in the continuous phase. The more specific mechanism predicted by the inventors of the present invention is as follows. First, it is considered that the metal complex of the (D2) component formed by the ligand exchange reaction of the (D1) component and the (D2) component precipitates metal particles by thermal decomposition, and the metal particles cover the above-mentioned (A) component. One or all of the surface.

FIG. 1 is an electron micrograph showing a state in which the metal ions are precipitated as fine particles (X in FIG. 1) on the surface of the component (A) (Y in FIG. 1) and the continuous phase. . Further, since the metal particles do not have an oxide film on the surface, they are excellent in conductivity.

By the above action, the conductive paste is excellent in electrical conductivity stability not only at room temperature but also at a high temperature. Further, since it was confirmed that the conductive paste has good screen printing suitability, fine wiring and minute electrodes can be formed. Moreover, the effects of the (D1) component, the (D2) component, and the (D3) component alone in the monomer are achieved when the (D1) component, the (D2) component, and the (D3) component cooperate with each other, and the taste is particularly deep. It deserves special mention.

Further, the component (D1) is not particularly limited as long as it is a metal salt of an organic monocarboxylic acid. A representative example of the organic monocarboxylic acid is one selected from the group consisting of formic acid, oxalic acid, salicylic acid, benzoic acid, glycolic acid, and glyoxylic acid. Further, a representative example of the metal is one selected from the group consisting of copper, silver, palladium, and platinum. Further, the component (D1) is not particularly limited. However, it is easy to carry out a ligand exchange reaction with the (D2) component, and it is safe to use, and it is easy to optimize the temporal conductivity stability and/or screen printing suitability of the conductive paste of the present embodiment. A suitable example of the component (D1) is copper formate and/or copper oxalate.

Further, the amount of the component (D1) used is not particularly limited. However, by From the viewpoint of the conductivity stability and/or the screen printing suitability, the amount of the component (D1) is preferably 0.5 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the component (A). From the same viewpoint, the above range is 3 mass parts or more, and 15 mass parts or less is more preferable.

Further, a representative example of the component (D2) is a diketone compound which acts as a chelating agent for monovalent or divalent metal ions. Various known diketone compounds can be used as the component (D2) without particular limitation. In this embodiment, the (D2) component forms a complex with a monovalent or divalent metal ion. Here, as a particularly suitable example of the component (D2), a ligand exchange reaction is likely to occur in the component (D1), and as a result, the conductive stability of the conductive paste of the present embodiment is imparted. Therefore, a β-diketone compound represented by the following general formula (Chemical Formula 2) is used as the component (D2), which is particularly suitable.

(In Chemical Formula 2, Y ¹ and Y ² may be the same or different and each represents an alkyl group, a fluoroalkyl group, an alkenyl group, an alkoxy group, a (meth) acrylonitrile group, a phenyl group, and a benzyl group. One functional group).

Further, the carbon number of the alkyl group, the alkenyl group and the alkoxy group is not particularly limited. These carbon numbers are represented by 6 or more and 18 or less. And the alkyl group, Alkenyl and alkoxy groups may also have a branch. Further, a halogen atom (chlorine, fluorine, or the like) may be bonded to one of the alkyl group, the alkenyl group, and the alkoxy group. Further, one or a plurality of functional groups selected from the group consisting of the alkyl group, the alkenyl group and the alkoxy group may be bonded to one of the phenyl groups in combination with an amine group, a nitro group or a hydroxyl group.

Representative examples of the above β-diketone compound are selected from the group consisting of methyl acetate, ethyl acetate, ethyl acetoacetate, butyl acetate, methyl 4-methoxyacetate, 2-B. Ethyl decyl ethoxymethyl propyl decanoate, methyl pivaloyl acetate, methyl isobutyroyl acetate, benzhydryl ethyl acetate, p-methoxybenzene Methyl thioglycolate, methyl hexyl thioacetate, methyl decyl methacrylate, methyl hexadecanoacetate, methyl 4-methoxy acetamidine ethyl ester, methyl acetonitrile methyl acetate, C At least one of the group consisting of diethyl acetoacetate, hexafluoroacetamidine, benzylidene acetonide, and benzhydrylmethane.

As an example of other (D2) components, dehydroacetic acid, ethyl 2-cyclopentanonecarboxylate, ethyl 2-cyclohexanonecarboxylate, methyl 2-cyclopentanonecarboxylate or 2-cyclohexanonecarboxylic acid a cyclic diketone compound such as an ester.

Further, the amount of the component (D2) used is not particularly limited. However, the amount of the (D2) component is preferably 0.1 part by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the component (A), from the viewpoint of the stability of the time-dependent conductivity and/or the suitability of the screen printing. From the same viewpoint, the above range is 0.5 mass% or more, and 5 mass parts or less is more preferable. Further, the above range is 1 part by mass or more, and particularly preferably 5 parts or less.

The component (D3) is representatively represented by the following general formula (Chemical Formula 3).

[Chemical Formula 3]

(In Chemical Formula 3, R ¹ , R ² , R ³ , R ⁴ and R ^{5 each} represent hydrogen, a hydroxyl group, an alkyl group, a carboxylic acid group or an amine group. Further, n is 0 or 1, and when n is 1, A is Indicates an alkylene group. Further, X represents a carboxylic acid group or a fluorenyl group.

Further, the carbon number of the alkyl group of the above Chemical Formula 3 is not particularly limited. The carbon number of the alkyl group represented is 1 or more and 9 or less. Further, the carbon number of the alkoxy group is not particularly limited. The carbon number of the alkoxy group represented is 1 or more and 4 or less. Further, the carbon number represented by A in the above Chemical Formula 3 is 1 or more and 3 or less. Also, the A may be a branched alkylene group. Further, any of R ¹ and R ⁵ of the above Chemical Formula 3 may be a carboxylic acid group, and when X is a carboxylic acid group, the two carboxylic acid groups form one of the acid anhydride rings.

Further, a representative example of the component (D3) wherein X is a carboxylic acid group is benzoic acid, p-hydroxybenzoic acid, salicylic acid, terephthalic acid, phthalic acid, phthalic anhydride or isophthalic acid, etc. . Other representative examples are p-ethylbenzoic acid, p-propylbenzoic acid, p-butylbenzoic acid, p-pentylbenzoic acid, p-hexylbenzoic acid, p-nonylbenzoic acid, m-aminobenzoic acid, 3,5-di Aminobenzoic acid and the like.

Further, a representative example of the (D3) component X being an aldehyde group is benzaldehyde, 2-methylbenzaldehyde, 4-methylbenzaldehyde, 2-methoxybenzaldehyde, 3-methoxybenzaldehyde, 4-methyl Oxybenzaldehyde, 4-butoxybenzaldehyde, p-isopropylbenzaldehyde, cyclamen aldehyde, 3,4-dihydroxybenzaldehyde, 2,4-dimethylbenzaldehyde, 2-ethoxybenzaldehyde , 4-ethoxybenzaldehyde, 4-ethylbenzaldehyde, 2-hydroxybenzaldehyde, 4-hydroxybenzaldehyde, 3,4-dimethoxybenzaldehyde, 2,3-dimethoxybenzaldehyde or 4 - Hydroxy-3,5-dimethoxybenzaldehyde and the like.

Further, from the viewpoint of temporal conductivity stability and/or screen printing suitability, a suitable example of the component (D3) is at least one selected from the group consisting of benzoic acid, aminobenzoic acid, and benzaldehyde.

Further, the amount of the component (D3) used is not particularly limited. However, the amount of the (D3) component is 0.1 part by mass or more and 15 parts or less, preferably about 10 parts by mass of the (A) component, from the viewpoint of the electrical conductivity stability over time and/or the suitability of the screen printing. It is 0.5 to 5 parts by mass, and more preferably 1 to 5 parts by mass.

<Other additives>

In the conductive paste of the present embodiment, other additives may be further mixed as needed. Specific examples of the other additives are a coupling agent, a surfactant, a hardener for the component (B), a conductive auxiliary agent, a leveling agent, an antifoaming agent, a thixotropic agent (fine cerium oxide, etc.), and/or a leveling agent.

Representative examples of the above coupling agent are known coupling agents such as a decane system, a titanate system, and an aluminate system. By using this coupling agent, the dispersibility of the component (A) in the conductive paste of the present embodiment and the adhesion of the component (A) to the component (B) can be improved.

A decane coupling agent can be suitably used to improve the adhesion between the conductive paste of the present embodiment and the substrate. As a specific kind thereof, for example, an epoxy functional decane such as 3-epoxypropyl ether propyl trimethoxy decane or 2-(3,4-epoxycyclohexane)ethyltrimethoxy decane, 3- Aminopropyltrimethoxy decane, N-2-(aminoethyl) 3-aminopropyltrimethoxy decane, N-2-(aminoethyl) 3-aminepropyl Dimethoxyoxane, vinyltrimethoxydecane, vinylphenyltrimethoxydecane, vinyltris(2-methoxyethoxy)decane, 3-propenyloxypropyltrimethoxydecane, 3 - methacryloxypropyltrimethoxydecane, 3-thiolpropyltrimethoxydecane, and the like.

Further, a representative example of the above surfactant is an amphoteric surfactant, an anionic surfactant, a cationic surfactant or a nonionic surfactant. The screen printing suitability of the conductive paste of the present embodiment can be improved by using a surfactant. Representative examples of the amphoteric surfactant are either alkylamine oxides or alkylbetaines. Further, representative examples of the anionic surfactant are alkyl sulfate, polyoxyethylene alkyl sulfate, alkylbenzenesulfonate, alkylnaphthalenesulfonate, fatty acid salt, and naphthalenesulfonic acid formalin condensate. a salt, a polycarboxylic acid type polymer surfactant, an alkenyl succinate, an alkyl sulfonate, a polyoxyalkylene alkyl ether, or a polyoxyalkylene alkyl ether phosphate or a salt thereof. Further, a representative example of the cationic surfactant is an alkylamine salt or a quaternary ammonium salt. Further, representative examples of the nonionic surfactant are polyoxyethylene alkyl ether, polyoxyalkylene alkyl ether, polyoxyethylene derivative, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester. , polyoxyethylene sorbitan fatty acid ester, glycerin fatty acid ester, polyoxyethylene fatty acid ester, polyoxyethylene hardened castor oil, polyoxyethylene alkylamine, polyoxyalkylene alkyleneamine or alkylalkanol Amidoxime and the like.

Further, the curing agent is one in which the component (B) contains a hydroxyl group in the molecule. Representative examples of the curing agent are aromatic diisocyanate such as toluene diisocyanate, diphenylmethane diisocyanate, and benzodimethyl diisocyanate, or hexamethylene diisocyanate or trimethylhexamethylene dichloride. Aliphatic diisocyanates such as isocyanate and lysine diisocyanate, or dicyclohexylmethane diisocyanate, different buddha A diisocyanate compound such as an alicyclic diisocyanate such as ketone diisocyanate, 1,4-cyclohexane diisocyanate, hydrogenated xylene diisocyanate or hydrogenated methyl phenyl diisocyanate. Further, a dimer and a trimer of each of the above diisocyanate compounds, and an isocyanate-based curing agent such as an adduct or a block thereof can be used.

Further, the component (B) is an element having an epoxy group in the molecule, and representative examples of the curing agent are amines such as melamine, urea, benzoguanamine, acetamide, spiroamine, and dicyandiamide. hardener.

In addition, the component (B) is a substance having a carboxylic acid group in the molecule, and a representative example of the curing agent is an aziridine-based curing agent or an epoxy-based curing agent.

Representative examples of the above conductive auxiliary agent are metal oxide such as indium tin oxide (ITO), antimony tin oxide (ATO), gallium-doped zinc oxide (GZO), aluminum-doped zinc oxide (AZO), or graphite powder, furnace black, and groove black. , carbon black, acetylene black, Ketjen black and other carbon-based fillers.

Representative examples of the above leveling agent are a decane-based leveling agent, a fluorine-based leveling agent, or an acrylic leveling agent.

The conductive paste of the present embodiment can be used for the above (A) component, (B) component, (C) component, (D1) component, (D2) component and (D3) component, and other additives as needed. By using a three-roller kneader, ultrasonic disperser, sand mill, grinder, bead mill, super grinder, ball mill, moving impeller, disperser, horizontal sand mill (KD mill), colloid mill It is produced by various known dispersing means such as a dynatron, a planetary mill, and/or a press kneader.

By coating the conductive paste of the present embodiment on various substrates Even printing, heat curing, and a conductive coating film, wiring, and electrodes can be obtained. Representative examples of the substrate are plastic films such as polyethylene terephthalate, polycarbonate, polyethylene, polyvinyl chloride, polypropylene, polystyrene or polymethyl methacrylate, or splashes in the plastic film. An ITO film or a glass plate obtained by plating ITO. Further, representative examples of the printing method are screen printing or gravure printing. Further, the heating temperature is not particularly limited. The representative heating temperature is 110 ° C or more and 150 ° C or less.

<Example>

Hereinafter, the above embodiment will be further specifically described by way of examples, but the above embodiments are not limited to the embodiments. Also, "part" is the quality benchmark.

[Example 1]

65.9 parts of copper particles (trade name "SCX-17", manufactured by DOWA Electronics Materials Co., Ltd., average primary particle diameter: 5.7 μm), phenol resin (PL-5208, manufactured by Kyoei Chemical Industry Co., Ltd., solid content 60% by mass) Diethylene glycol monoethyl ether solution) 13.6 parts, diethylene glycol monoethyl ether acetate (hereinafter also referred to as DEGMEEA) 10.2 parts, copper oxalate 0.5 hydrate 5.7 parts, acetamidine acetone 2.3 parts and benzoic acid 2.3 The part is twisted by a three-roller machine to obtain a conductive paste.

[Embodiment 2]

53.1 parts of copper particles (SCX-17), phenoxy resin (trade name "YP-50", manufactured by Nippon Steel Co., Ltd., a solid content of 35 mass% of diethylene glycol monoethyl ether solution) 13.5, 5.7 parts of copper (II) formate hydrate, 2.3 parts of acetamidine acetone, 2.3 parts of benzoic acid and 26.3 parts of diethylene glycol monoethyl ether acetate (DEGMEEA) were combined by a three-roller machine to obtain a conductive paste. material.

[Example 3]

In addition to making the phenoxy resin YP-50 9.5, the polyester resin (trade name) "XA0653", UNITIKA Co., Ltd., 40% by mass of ethylene glycol monoethyl ether solution), and 4.1 parts of DEGMEEA, with (D1) to (D3) The same treatment as in Example 2 was carried out to obtain a conductive paste. Further, the ratio of the component (A) may be changed according to the variation of the above respective ratios (the same applies to the description of each of the following examples, comparative examples, and reference examples).

[Example 4]

In addition, the phenoxy resin YP-50 was 8.0 parts, and the polyester resin (trade name "XA0653", manufactured by UNITIKA Co., Ltd., 40% by mass of ethylene glycol monoethyl ether solution) was used. The DEGMEEA was treated in the same ratio as in Example 2 except for the point of 28.4, and a conductive paste was obtained by the same ratio as in the case of Example 2 (D1).

[Example 5]

13.6 parts of copper particles (SCX-17), part 65.9, phenolic resin (PL-5208, manufactured by Kyoei Chemical Industry Co., Ltd., solid content 60% by mass diethylene glycol monoethyl ether solution), DEGMEEA 10.2 The part, 5.7 parts of copper (II) formate tetrahydrate, 2.3 parts of acetamidine acetone, and 2.3 parts of benzoic acid were twisted together in a three-roller machine to obtain a conductive paste.

[Embodiment 6]

In the same manner as in the fifth embodiment except that the copper particles (SCX-17) were changed to other copper particles (trade name "FCC-TB", manufactured by Fukuda Metal Foil Co., Ltd., average primary particle diameter: 7 μm). The ratio is processed to obtain a conductive paste.

[Embodiment 7]

In addition to changing copper particles (SCX-17) to other copper particles (trade name) A conductive paste was obtained by treating in the same ratio as in Example 5 except that "FCC-CP-X5", manufactured by Fukuda Metal Foil Co., Ltd., having an average primary particle diameter of 15 μm.

[Embodiment 8]

A conductive paste was obtained by treating in the same ratio as in Example 5 except that copper (II) hydride hydrate was changed to 11.4.

[Embodiment 9]

A conductive paste was obtained by treating in the same ratio as in Example 6 except that benzoic acid was changed to m-aminobenzoic acid.

[Embodiment 10]

A conductive paste was obtained by treating in the same ratio as in Example 9 except that the m-aminobenzoic acid was changed to 3,5-diaminobenzoic acid.

[Example 11]

A conductive paste was obtained by treating in the same ratio as in Example 10 except that 3,5-diaminobenzoic acid was changed to benzaldehyde.

[Embodiment 12]

A conductive paste was obtained by treating in the same ratio as in Example 6 except that acetonitrile was changed to ethyl acetacetate.

[Example 13]

A conductive paste was obtained by treating in the same ratio as in Example 12 except that ethyl acetamacetate was changed to ethyl acetate.

[Embodiment 14]

65.9 parts of copper particles (SCX-17), phenolic resin (trade name "PL-5208", manufactured by Kyoei Chemical Industry Co., Ltd., solid content 60% by mass 13.6 parts of diol monoethyl ether solution, DEGMEEA 10.2, 5.7 parts of silver formate, 2.3 parts of acetamidine and 2.3 parts of benzoic acid were twisted together in a three-roller machine to obtain a conductive paste.

[Comparative Example 1]

A conductive paste was obtained by kneading 90 copper particles (SCX-17) and 20.0 phenol resin (PL-5208) in a three-roller machine.

[Comparative Example 2]

A conductive paste was obtained by twisting 90 pieces of copper particles (SCX-17), 20.0 parts of phenol resin (PL-5208), and 2.0 parts of benzoic acid in a three-roller machine. Further, Fig. 2 is an electron microscope photograph corresponding to Fig. 1 in Comparative Example 2. As shown in Fig. 2, the precipitate observed in Fig. 1 (which is considered to be such a substance) was not observed.

[Comparative Example 3]

A conductive paste was obtained by treating in the same ratio as in Example 6 except that benzoic acid and copper (II) formate tetrahydrate were not used.

[Reference example]

In the case of silver particles (trade name "SILFLAKE 241", manufactured by Technic, average primary particle diameter: 2.7 μm), 70.1 parts, epoxy resin (trade name "jer-1007", manufactured by Mitsubishi Chemical Corporation, 100% by mass of solid content) 6.1, phenolic resin (trade name "Hitanol 3305N", manufactured by Hitachi Chemical Co., Ltd., solid content 40% by weight diethylene glycol monoethyl ether acetate) 2.6, DEGMEEA 10.4, diethylene glycol butyl ether 7.5 Part 3.3 and diethylene glycol butyl ether acetate were combined in a three-roller machine to obtain a conductive paste.

【Table 1】

In Tables 1 and 2, the "mass portion" is a converted value when the component (A) is 100 mass parts. Further, the value of the mass portion of the (B) component is considered to be the mass portion of the diethylene glycol monoethyl ether acetate contained in the component (B).

<Formation of Coating Film of Conductive Paste>

Each of the conductive pastes of the examples and the comparative examples was printed on a soda glass plate under a printing condition to have a film thickness of 8 μm, and dried at 150 ° C for 60 minutes to form a cured coating film.

Screen printing plate: polyester 180 mesh (wire diameter 48 μm), emulsifier = 25 μm.

Frame size: 320mm × 320mm.

Squeegee speed: 200mm/sec.

Scraper hardness: 80 degrees.

Scraper angle: 65 degrees.

Doctor speed: 200 mm/sec.

Clearance: 1.5mm.

Then, a commercially available four-terminal type electric resistance meter (product name "mΩ HiTESTER 3540", manufactured by Nikken Electric Co., Ltd.) was used, and the initial volume resistivity of the coating film immediately after drying was 12 hours, 72 hours, and 192, respectively. The volume resistivity (in Ω.cm) at hours and 520 hours was measured at 80 °C. Further, with respect to the coating films of Examples 1 to 8, the volume resistivity at 1000 hours was measured at 80 °C.

In addition, the above-described embodiments and examples are disclosed for the purpose of describing the embodiments and examples, and are not intended to limit the invention. Further, modifications including the above-described embodiments or other combinations of the embodiments, which are within the scope of the invention, are also included in the scope of the present application.

[Industrial availability]

The conductive paste of the above-described embodiment and each of the examples is mainly used as an electrode of an electronic component or an electrode such as a wiring for a printed wiring board. Moreover, it can also be applied to various uses of other printed and non-printed conductive pastes. For example, the conductive paste of the present embodiment can be applied to a condenser external electrode, a solar cell conductive circuit, an ITO glass electrode, a TO glass electrode, and a stamp. A soldering conductive portion or the like is attached to the brush circuit.

Further, the cured product, the electronic component, or the electronic device including the conductive paste of each of the above embodiments can be applied to a wide range of applications in the same manner as the conductive paste of each of the above embodiments.

X‧‧‧(A) ingredients

Y‧‧‧fine particles

Claims (14)

A conductive paste comprising: (A) metal microparticles, (B) a resin binder, and (C) an organic solvent, and further comprising: (D1) an organic monocarboxylic acid metal salt, and a (D2) diketone chelating agent (D3) an aromatic compound represented by the following general formula (Chemical Formula 1), (In Chemical Formula 1, R ¹ , R ² , R ³ , R ⁴ and R ^{5 each} represent hydrogen, a hydroxyl group, an alkyl group, a carboxylic acid group or an amine group, and further, n is 0 or 1, and when n is 1, A is Represents an alkylene group and, further, X represents a carboxylic acid group or a fluorenyl group.) The conductive paste according to claim 1, wherein the metal particles formed by the ligand exchange reaction of the (D1) component and the (D2) component cover a surface of the component (A) or All. The conductive paste according to any one of claims 1 to 2, wherein the organic monocarboxylic acid constituting the component (D1) is selected from the group consisting of formic acid, oxalic acid, salicylic acid, benzoic acid, and glycolic acid. One species of the group consisting of glyoxylic acid. The conductive paste according to any one of claims 1 to 3, wherein the metal constituting the component (D1) is at least one selected from the group consisting of copper, silver, palladium and platinum. The conductive paste according to any one of the above-mentioned items (1), wherein the amount of the component (D1) is 0.5 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the component (A). The conductive paste according to any one of the above-mentioned items (1), wherein the amount of the component (D2) is 0.1 part by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the component (A). The conductive paste according to any one of claims 1 to 6, wherein the component (D3) is at least one selected from the group consisting of benzoic acid, aminobenzoic acid, and benzaldehyde. The conductive paste according to any one of the above-mentioned items (1), wherein the amount of the component (D3) is 0.1 part by mass or more and 15 parts by mass or less with respect to 100 parts by mass of the component (A). The conductive paste according to any one of claims 1 to 8, wherein the metal microparticles of the component (A) are selected from the group consisting of copper, cobalt, iron, zinc, aluminum, titanium, vanadium, manganese, zirconium, At least one of a group consisting of molybdenum, indium, antimony, bismuth, tungsten, and an alloy containing at least one of the foregoing metals. The conductive paste according to claim 9, wherein the metal fine particles have an average particle diameter of 0.05 μm or more and 50 μm or less. The conductive paste according to any one of claims 1 to 10, wherein the component (B) is selected from the group consisting of a phenol resin, a polyester resin, an epoxy resin, a polyurethane resin, and an acrylic resin. At least one. The conductive paste according to any one of the above-mentioned items (1), wherein the amount of the component (B) is 1 part by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the component (A). The conductive paste according to any one of claims 1 to 12, wherein the component (C) is selected from the group consisting of an ether alcohol, a non-ether alcohol, an ester solvent, a ketone solvent, and an aliphatic solvent. At least one of a group consisting of an aromatic solvent and a plant solvent. The conductive paste according to any one of the above-mentioned items (1), wherein the amount of the component (C) is 1 part by mass or more and 30 parts by mass or less with respect to 100 parts by mass of the component (A).