Resin composition, method for forming cured product, and cured product

Abstract

Provided are: a resin composition that contains copper particles and a specific resin, and is capable of producing a cured product having a low volume resistance value; and a cured product obtained by curing the resin composition. Said resin composition contains: (A) copper particles having an average particle size of 0.1-20 μm; (B) a phosphoric acid-modified epoxy resin obtained by reacting a phosphoric acid (b1) with an epoxy compound (b2); and (C) a hardener, wherein the content of the component (B) is 0.1-30 parts by mass and the content of the component (C) is 0.1-5 parts by mass, with respect to 100 parts by mass of the total amount of the components (A) to (C). Furthermore, said cured product is obtained by curing the resin composition.

Description

[Technical field]

[0001] The present invention relates to a resin composition containing copper particles and a specific resin, a method for forming a cured product of this resin composition, and the cured product. [Background technology]

[0002] Resin compositions containing conductive metals are used as one of the materials for forming circuit wiring, touch panels, solar cells, sensors, etc. Currently, copper particles, which have low production costs, are attracting particular attention as a conductive metal, and various resin compositions containing copper particles are being investigated.

[0003] For example, Patent Document 1 discloses a conductive copper paste composition containing copper powder, a phenolic resin, an imidazole compound, a polyhydric phenol monomer, and a reactive rubber elastomer. Patent Document 2 discloses an aqueous copper paste material containing flaky copper powder, electrolytic spherical copper powder, a reducing agent, and an aqueous resin. Patent Document 3 discloses a copper paste composition containing copper particles, a resol-type phenolic resin, and a vinylphenol-based polymer. Patent Document 4 discloses a conductive copper paste containing copper particles, a resol-type phenolic resin, an epoxy resin, and an organic acid. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Publication No. 9-12937 [Patent Document 2] JP 2013-115004 A [Patent Document 3] JP 2018-92864 A [Patent Document 4] JP 2018-181558 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, there has been a problem in that a cured product obtained by curing a coating film formed using a resin composition or the like as disclosed in Patent Documents 1 to 4 has a high volume resistivity and is prone to a decrease in electrical conductivity.

[0006] Therefore, the present invention has been made to solve the above problems, and an object of the present invention is to provide a resin composition containing copper particles and a specific resin, capable of producing a cured product with low volume resistivity. Another object of the present invention is to provide a method for forming a cured product using the above resin composition, and a cured product obtained by curing the above resin composition. [Means for solving the problem]

[0007] Means of Solving the Problems The present inventors have conducted extensive research to solve the above problems and have found that a resin composition containing a specific component can solve the above problems, thereby completing the present invention.

[0008] That is, according to the present invention, there is provided a resin composition comprising (A) copper particles having an average particle size of 0.1 to 20 μm, (B) a phosphoric acid-modified epoxy resin obtained by reacting phosphoric acids (b1) with an epoxy compound (b2), and (C) a curing agent, in which the content of the (B) component is 0.1 to 30 parts by mass and the content of the (C) component is 0.1 to 5 parts by mass relative to 100 parts by mass of the total amount of the (A) to (C) components.

[0009] According to the present invention, there is also provided a method for forming a cured product, the method including: a coating step of coating the above-mentioned resin composition onto a substrate; and a curing step of heating the substrate onto which the resin composition has been coated, to cure the resin composition.

[0010] Furthermore, according to the present invention, there is provided a cured product obtained by curing the above-mentioned resin composition. Effect of the Invention

[0011] According to the present invention, it is possible to provide a resin composition containing copper particles and a specific resin, which is capable of producing a cured product having a low volume resistivity. Also, according to the present invention, it is possible to provide a method for forming a cured product using the above-mentioned resin composition, and a cured product obtained by curing the above-mentioned resin composition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Hereinafter, an embodiment of the present invention will be described in detail. A resin composition according to one embodiment of the present invention is a resin composition comprising, as essential components, (A) copper particles having an average particle size of 0.1 to 20 μm (hereinafter also referred to as "component (A)"); (B) a phosphoric acid-modified epoxy resin obtained by reacting phosphoric acids (b1) with an epoxy compound (b2) (hereinafter also referred to as "component (B)"); and (C) a curing agent (hereinafter also referred to as "component (C)").

[0013] The component (A) is copper particles having an average particle size of 0.1 to 20 μm. The type of copper particles is not particularly limited, and well-known general copper particles can be used. The average particle size of the copper particles is 0.1 to 20 μm, preferably 0.5 to 10 μm, and more preferably 1.0 to 5 μm. The average particle size of the copper particles is the particle size at which the cumulative 50% of the volume-based particle size distribution is reached (D 50 ) represents the shape of the copper particles. The shape of the copper particles is not particularly limited, and one or more types of copper particles such as granular, needle-like, and flake-like can be used. Among them, it is preferable to contain granular copper particles, and it is more preferable to contain both granular and flake-like copper particles, since the conductivity of the resulting cured product is high. In this specification, both scale-like copper particles and plate-like copper particles are included in the flake-like copper particles. The content of the granular copper particles is preferably 70 to 100 parts by mass, and more preferably 75 to 95 parts by mass, relative to 100 parts by mass of the total amount of the (A) component. The content of the flake-like copper particles is preferably 0 to 30 parts by mass, and more preferably 5 to 25 parts by mass, relative to 100 parts by mass of the total amount of the (A) component.

[0014] When the copper particles are oxidized by air, etc., it is preferable to wash the copper particles in advance with an aqueous solution containing an inorganic acid or an organic acid dissolved therein. For example, an aqueous solution containing sulfuric acid dissolved therein is preferably used as the aqueous solution for washing the copper particles.

[0015] The (B) component is a phosphoric acid-modified epoxy resin. This (B) phosphoric acid-modified epoxy resin is a reaction product of phosphoric acid (b1) and epoxy compound (b2). The phosphoric acid (b1) is not particularly limited as long as it is a compound having a phosphoric acid bond in its molecule. Examples of such phosphoric acid (b1) include phosphoric acid (orthophosphoric acid: H3PO4), phosphorous acid (H3PO3), hypophosphorous acid (H3PO2), phosphonic acid (H3PO3), diphosphoric acid (pyrophosphoric acid: H4P2O7), and polyphosphoric acid such as triphosphoric acid. Among these, phosphoric acid (H3PO4) is preferred because the resulting cured product has high electrical conductivity.

[0016] The epoxy compound (b2) is not particularly limited as long as it is a compound having one or more epoxy groups in its molecule. Examples of such epoxy compounds (b2) include n-butyl glycidyl ether, C 12 ~C 14reactive diluents having one epoxy group, such as alkyl glycidyl ether of the above, allyl glycidyl ether, 2-ethylhexyl glycidyl ether, styrene oxide, phenyl glycidyl ether, cresyl glycidyl ether, p-sec-butylphenyl glycidyl ether, t-butylphenyl glycidyl ether, glycidyl methacrylate, and tertiary carboxylic acid glycidyl ester; reactive diluents having two epoxy groups, such as ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, and neopentyl glycol diglycidyl ether; reactive diluents having three epoxy groups, such as trimethylolpropane triglycidyl ether and glycerin triglycidyl ether; bisphenol A type epoxy resins, and Examples of the epoxy compounds include bisphenol type epoxy resins such as bisphenol F type epoxy resins; biphenyl type epoxy resins and tetramethylbiphenyl type epoxy resins; dicyclopentadiene type epoxy resins; naphthalene type epoxy resins; alicyclic epoxy resins obtained from cyclohexane dimethanol, hydrogenated bisphenol A, etc.; novolac type epoxy resins such as phenol novolac type epoxy resins, cresol novolac type epoxy resins, bisphenol A novolac type epoxy resins, epoxidized products which are condensates of phenols and aromatic aldehydes having phenolic hydroxyl groups, and biphenyl novolac type epoxy resins; triphenylmethane type epoxy resins; tetraphenylethane type epoxy resins; dicyclopentadiene-phenol addition reaction type epoxy resins; and phenol aralkyl type epoxy resins. These epoxy compounds (b2) may be used alone or in combination of two or more.

[0017] Among the specific examples of the epoxy compound (b2) described above, it is preferable to use a bisphenol-type epoxy resin, a biphenyl-type epoxy resin, or an alicyclic epoxy resin, which are easily available and inexpensive and have good physical properties after curing, and it is more preferable to use a bisphenol-type epoxy resin.

[0018] (B) phosphoric acid-modified epoxy resin is a phosphorus atom-containing epoxy compound having an epoxy group at its terminal. (B) phosphoric acid-modified epoxy resin can be obtained by reacting phosphoric acid (b1) with epoxy compound (b2). Preferably, phosphoric acid (b1) can be obtained by reacting epoxy compound (b2) with phosphoric acid (b1) at 20 to 100°C. After reacting phosphoric acid (b1) with epoxy compound (b2) in the presence of a solvent, the solvent may be removed. It is preferable to react phosphoric acid (b1) with epoxy compound (b2) so that the number of epoxy groups in epoxy compound (b2) is greater than the number of active hydrogens in phosphoric acid (b1). When a plurality of epoxy compounds (b2) are used, it is preferable to synthesize phosphorus-modified epoxy resin (B) as follows. First, phosphoric acid (b1) is reacted with at least one epoxy compound (b2) under conditions in which the number of active hydrogens in the phosphoric acid (b1) is greater than the number of epoxy groups in the epoxy compound (b2), to synthesize a phosphorus-modified epoxy compound (intermediate) in which active hydrogens derived from the phosphoric acid (b1) remain. Next, the synthesized phosphorus-modified epoxy compound (intermediate) is reacted with at least one other epoxy compound (b2), to finally obtain a phosphorus-atom-containing epoxy compound having an epoxy group at its terminal as component (B).

[0019] Examples of the solvent used when reacting the phosphoric acid (b1) with the epoxy compound (b2) include ketones such as methyl ethyl ketone, methyl amyl ketone, diethyl ketone, acetone, methyl isopropyl ketone, propylene glycol monomethyl ether acetate, and cyclohexanone; ethers such as tetrahydrofuran, 1,2-dimethoxyethane, 1,2-diethoxyethane, and propylene glycol monomethyl ether; esters such as ethyl acetate and n-butyl acetate; aromatic hydrocarbons such as benzene, toluene, and xylene; halogenated aliphatic hydrocarbons such as carbon tetrachloride, chloroform, trichloroethylene, and methylene chloride; and halogenated aromatic hydrocarbons such as chlorobenzene. Among these, ketones are preferred from the viewpoint of ease of removal after the reaction, and methyl ethyl ketone and methyl isopropyl ketone are more preferred.

[0020] Bisphenol-type epoxy resins and novolac-type epoxy resins that can be used as the epoxy compound (b2) do not have a single repeating unit, and it is difficult to define their overall structure using a chemical formula or a general formula. Furthermore, during the synthesis process of the phosphoric acid-modified epoxy resin (B), a side reaction may occur in which the hydroxyl group generated from the epoxy compound (b2) reacts with other epoxy groups in the epoxy compound (b2), so the structure of the phosphoric acid-modified epoxy resin (B) may become complicated. Therefore, the structure of the phosphoric acid-modified epoxy resin (B) is not uniform, but is rich in variety, and it is practically impossible to define the structure by a uniform chemical bond or general formula. For the above reasons, the phosphoric acid-modified epoxy resin (B) must be defined by its manufacturing method.

[0021] In the process for producing the phosphoric acid-modified epoxy resin (B), it is preferred that the compound used as the modifier for the starting epoxy compound (b2) is only the phosphoric acid (b1).

[0022] The content of the (B) component in the resin composition is 0.1 to 30 parts by mass relative to 100 parts by mass of the total of the (A) to (C) components. The content of the (B) component in the resin composition is preferably 1 to 20 parts by mass, more preferably 5 to 15 parts by mass, relative to 100 parts by mass of the total of the (A) to (C) components, because the electrical conductivity of the resulting cured product is increased. If the content of the (B) component is less than 0.1 parts by mass relative to 100 parts by mass of the total of the (A) to (C) components, the effect of including the (B) component is not easily obtained. On the other hand, even if the content of the (B) component is more than 30 parts by mass relative to 100 parts by mass of the total of the (A) to (C) components, the effect of including the (B) component is not easily improved.

[0023] Component (C) is a curing agent that cures the phosphoric acid-modified epoxy resin (B), which is an epoxy compound. Examples of the curing agent (C) include latent curing agents, acid anhydrides, polyamine compounds, polyphenol compounds, and cationic photoinitiators.

[0024] Examples of the latent curing agent include dicyandiamide, hydrazide, imidazole compound, amine adduct, sulfonium salt, onium salt, ketimine, acid anhydride, and tertiary amine, etc. Use of these latent curing agents is preferable because it allows the resin composition containing the additive for forming a cured product to be a one-liquid type curable resin composition that is easy to handle.

[0025] Examples of the imidazole compound include 2-methylimidazole, 2-phenylimidazole, 2-undecylimidazole, 2-heptadecylimidazole, 2-phenyl-4-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 1-benzyl-2-phenylimidazole, 1-benzyl-2-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 2,4-diamino-6(2'-methylimidazole(1'))ethyl-s-triazine, 2,4-diamino-6(2'-undecylimidazole(1'))ethyl-s-triazine ... Examples of imidazoles include 2-methylimidazole-4-hydroxymethyl-5-methylimidazole, 1-cyanoethyl-2-phenyl-3,5-dicyanoethoxymethylimidazole, and other imidazoles; and salts of these imidazoles with polycarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, trimellitic acid, pyromellitic acid, naphthalenedicarboxylic acid, maleic acid, and oxalic acid. Among these, 2-ethyl-4-methylimidazole is preferred from the standpoint of curability and storage stability. Examples of commercially available products include those with the trade names "2P4MHZ-PW", "2P4MHZ", and "2E4MZ" (all manufactured by Shikoku Chemical Industry Co., Ltd.).

[0026] Examples of acid anhydrides include phthalic anhydride, trimellitic anhydride, pyromellitic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, maleic anhydride, succinic anhydride, and 2,2-bis(3,4-dicarboxyphenyl)-1,1,1,3,3,3-hexafluoropropane dianhydride.

[0027] Examples of the polyamine compound include aliphatic polyamines such as ethylenediamine, diethylenetriamine, and triethylenetetramine; alicyclic polyamines such as menthenediamine, isophoronediamine, bis(4-amino-3-methylcyclohexyl)methane, bis(aminomethyl)cyclohexane, and 3,9-bis(3-aminopropyl)2,4,8,10-tetraoxaspiro[5,5]undecane; aliphatic amines having an aromatic ring such as m-xylenediamine; and aromatic polyamines such as m-phenylenediamine, 2,2-bis(4-aminophenyl)propane, diaminodiphenylmethane, diaminodiphenylsulfone, α,α-bis(4-aminophenyl)-p-diisopropylbenzene, and 2,2-bis(4-aminophenyl)-1,1,1,3,3,3-hexafluoropropane.

[0028] Examples of polyphenol compounds include phenol novolac, o-cresol novolac, t-butylphenol novolac, dicyclopentadiene cresol, terpene diphenol, terpene dicatechol, 1,1,3-tris(3-tert-butyl-4-hydroxy-6-methylphenyl)butane, butylidene bis(3-tert-butyl-4-hydroxy-6-methylphenyl), and 2,2-bis(4-hydroxyphenyl)-1,1,1,3,3,3-hexafluoropropane.

[0029] As the component (C), it is preferable to use a latent curing agent, and among these, it is more preferable to use an imidazole compound.

[0030] The content of the (C) component in the resin composition is 0.1 to 5 parts by mass relative to 100 parts by mass of the total of the (A) to (C) components. The content of the (C) component in the resin composition is preferably 0.3 to 4 parts by mass, more preferably 0.5 to 3 parts by mass, relative to 100 parts by mass of the total of the (A) to (C) components. If the content of the (C) component is less than 0.1 parts by mass relative to 100 parts by mass of the total of the (A) to (C) components, the resin composition is difficult to cure. On the other hand, even if the content of the (C) component is more than 5 parts by mass relative to 100 parts by mass of the total of the (A) to (C) components, the effect of including the (C) component is difficult to improve.

[0031] The resin composition according to one embodiment of the present invention preferably further contains (D) at least one resin selected from the group consisting of xylene resins, phenolic resins, and epoxy resins (excluding the component (B)). By using the components (A), (B), and (C) in combination with the component (D), it is possible to obtain a resin composition capable of producing a cured product having a lower volume resistivity.

[0032] As the xylene resin, for example, resol type xylene resin, alkylphenol modified xylene resin, novolac type xylene resin, polyol modified xylene resin, ethylene oxide modified xylene resin, etc. can be used. Among them, it is preferable to use resol type xylene resin. In addition, commercially available products can also be used. As commercially available xylene resin, for example, resol type xylene resin (manufactured by Fudow Co., Ltd., product names: PR-1440, PR-1440M), alkylphenol modified xylene resin (manufactured by Fudow Co., Ltd., product names: GHP-150, HP-120, HP-100, HP-210, HP-70), novolac type xylene resin (manufactured by Fudow Co., Ltd., product names: NP-100, GP-212, P-100, GP-200, HP-30), polyol modified xylene resin (manufactured by Fudow Co., Ltd., product name: K-100), ethylene oxide modified xylene resin (manufactured by Fudow Co., Ltd., product name: L5), etc. can be mentioned.

[0033] As the phenolic resin, for example, novolac type phenolic resin or resol type phenolic resin can be used. Among them, it is preferable to use resol type phenolic resin. Commercially available products can also be used. Examples of commercially available phenolic resins include powdered phenolic resins (manufactured by Gun-ei Chemical Industry Co., Ltd., product names: Resitop, PGA-4528, PGA-2473, PGA-4704, PGA-4504, manufactured by Sumitomo Bakelite Co., Ltd., product names: SUMILITE RESIN PR-UFC-504, PR-EPN, PR-ACS-100, PR-ACS-150, PR-12687, PR-13355, PR-16382, PR-217, PR-310, PR-311, PR-50064, PR-50099, PR-50102, PR -50252, PR-50395, PR-50590, PR-50590B, PR-50699, PR-50869, PR-51316, PR-51326B, PR-51350B, PR-51510, PR-51541B, PR-51794, PR -51820, PR-51939, PR-53153, PR-53364, PR-53497, PR-53724, PR-53769, PR-53804, PR-54364, PR-54458A, PR-54545, PR-55170, PR-80 00, PR-FTZ-1, PR-FTZ-15), flake phenolic resin (manufactured by Sumitomo Bakelite Co., Ltd., product name: SUMILITE RESIN PR-12686R, PR-13349, PR-50235A, PR-51363F, PR-51494G, PR-51618G, PR-53194, PR-53195, PR-54869, PR-F-110, PR-F-143, PR-F-151F, PR-F-85G, PR-HF-3, PR-HF-6), liquid phenolic resin (manufactured by Sumitomo Bakelite Co., Ltd., product name: SUMILITE RESIN PR-50087, PR-50607B, PR-50702, PR-50781, PR-51138C, PR-51206, PR-51663, PR-51947A, PR-53123, PR-53338, PR-53365, PR-53717, PR-54135, PR-54313, PR-54562, PR-55345, PR-940, PR-9400, PR-967), resol type liquid phenolic resin (Gun-ei Chemical Co., Ltd., product name: Resitop PL-4826, PL-2390,PL-4690, PL-3630, PL-4222, PL-4246, PL-2211, PL-3224, PL-4329, PL-5208, manufactured by Sumitomo Bakelite Co., Ltd., product name: SUMILITE RESIN PR-50273, PR-51206, PR-51781, PR-53056, PR-53311, PR-53416, PR-53570, PR-54387), fine granular phenolic resin (manufactured by Airwater Co., Ltd., product name: Bellpearl, R800, R700, R600, R200, R100, S830, S870) , S890, S895, S290, S190), spherical phenolic resins (manufactured by Gun-ei Chemical Industry Co., Ltd., trade names: Marilyn GU-200, FM-010, FM-150, HF-008, HF-015, HF-075, HF-300, HF-500, HF-1500), solid phenolic resins (manufactured by Gun-ei Chemical Industry Co., Ltd., trade names: Resitop PS-2601, PS-2607, PS-2655, PS-2768, PS-2608, PS-4609, PSM-2222, PSK-2320, PS-6132), etc.

[0034] Examples of epoxy resins (excluding component (B)) include, by trade name, bisphenol A type epoxy resins AER-X8501 (manufactured by Asahi Chemical Industry Co., Ltd.), R-301 (manufactured by Mitsubishi Chemical Corporation), and YL-980 (manufactured by Mitsubishi Chemical Corporation); bisphenol F type epoxy resins YDF-170 (manufactured by Tohto Kasei Co., Ltd.), YL-983 (manufactured by Mitsubishi Chemical Corporation), and YL-983U (manufactured by Mitsubishi Chemical Corporation); epoxy resins having a glycidyl group (Denacol EX-121, Denacol EX-171, Denacol EX-192, Denacol EX-211, Denacol EX-221, Denacol EX-231, Denacol EX-241, Denacol EX-251, Denacol EX-261, Denacol EX-271, Denacol EX-281, Denacol EX-291, Denacol EX-301, Denacol EX-311, Denacol EX-321, Denacol EX-331, Denacol EX-341, Denacol EX-351, Denacol EX-361, Denacol EX-371, Denacol EX-381, Denacol EX-391, Denacol EX-401, Denacol EX-411, Denacol EX-421, Denacol EX-431, Denacol EX-441, Denacol EX-451, Denacol EX-451, Denacol EX-461, Denacol EX-471, Denacol EX-481, Denacol EX-491, Denacol EX-491, Denacol EX-401, Denacol EX-411, Denacol EX-421, Denacol EX-431, Denacol EX-4 212, Denacol EX-313, Denacol EX-314, Denacol EX-321, Denacol EX-411, Denacol EX-421, Denacol EX-512, Denacol EX-521, Denacol EX-611, Denacol EX-612, Denacol EX-614, Denacol EX-622, Denacol EX-810, Denacol EX-811, Denacol EX-850, Denacol EX-851, Denacol EX-821, Denacol EX-830, Denacol EX-832, Denacol EX-841, Denacol EX- 861, Denacol EX-911, Denacol EX-941, Denacol EX-920, Denacol EX-931, Denacol EX-145, Denacol EX-146, Denacol EX-147, Denacol EX-201, Denacol EX-711, Denacol EX-721, Oncoat EX-1020, Oncoat EX-1030, Oncoat EX-1040, Oncoat EX-1050, Oncoat EX-1051, Oncoat EX-1010, Oncoat EX-1011, Oncoat 1012 (manufactured by Nagase ChemteX Corporation); E Polite M-1230, Epolight 40E, Epolight 100E, Epolight 200E, Epolight 400E, Epolight 70P, Epolight 200P, Epolight 400P, Epolight 1500NP, Epolight 1600, Epolight 80MF, Epolight 100MF (manufactured by Kyoeisha Chemical Co., Ltd.), Oxol PG-100, Oxol EG-200, Oxol EG-210, Oxol EG-250 (manufactured by Osaka Gas Chemical Co., Ltd.), HP4032, HP4032D, HP4700 (manufactured by DIC Corporation), ESN-475V (manufactured by Nippon Steel & Sumitomo Metal Chemical Co., Ltd.);152, 154, 157S70, YX8800 (manufactured by Mitsubishi Chemical), ADEKA GLYCILOR ED-503, ADEKA GLYCILOR ED-503G, ADEKA GLYCILOR ED-506, ADEKA GLYCILOR ED-523T, ADEKA RESIN EP-4100, ADEKA RESIN EP-4100G, ADEKA RESIN EP-4100E, ADEKA RESIN EP-4100L, ADEKA RESIN EP-4100TX, ADEKA RESIN EP-4000, ADEKA RESIN EP-4005, ADEKA RESIN EP-4080E, ADEKA RESIN EP-4082HT, ADEKA RESIN EP-4901, ADEKA RESIN EP-4901E, ADEKA GLYCILOR ED-501, ADEKA GLYCILOR ED-509E, ADEKA GLYCILOR ED-509S, ADEKA GLYCILOR ED-529 (manufactured by ADEKA Corporation); polyalkyleneoxy bisphenol A type epoxy resins EXA-4816 (manufactured by Dainippon Ink and Chemicals Co., Ltd.), EXA-4822 (manufactured by Dainippon Ink and Chemicals Co., Ltd.); bisphenol AD ​​type epoxy resin R-1710 (manufactured by Mitsui Petrochemical Industries Co., Ltd.); phenol novolac type epoxy resin N-730S (manufactured by Dainippon Ink and Chemicals Co., Ltd.), Quatrex -2010 (Dow Chemical Company); cresol novolac type epoxy resins YDCN-702S (Tohto Kasei Co., Ltd.), EOCN-100 (Nippon Kayaku Co., Ltd.); multifunctional epoxy resins EPPN-501 (Nippon Kayaku Co., Ltd.), TACTIX-742 (Dow Chemical Company), VG-3010 (Mitsui Petrochemical Co., Ltd.), 1032S (Mitsubishi Chemical Co., Ltd.), 1032-H60 (Mitsubishi Chemical Co., Ltd.); naphthalene-based epoxy resin HP-4032 (Dainippon Ink and Chemicals Co., Ltd.); alicyclic epoxy resins EHPE-3150, CEL-3000 (Dainippon Ink and Chemicals Co., Ltd.) Cel Chemical Industry Co., Ltd.), DME-100 (Shin-Nippon Rika Co., Ltd.), EX-216L (Nagase Chemical Industry Co., Ltd.); aliphatic epoxy resin W-100 (Nagase Chemical Industry Co., Ltd.); amine-type epoxy resins ELM-100 (Sumitomo Chemical Co., Ltd.), YH-434L (Tohto Kasei Co., Ltd.), TETRAD-X, TETRAD-C (Mitsubishi Gas Chemical Co., Ltd.), 630, 630LSD (Mitsubishi Chemical Co., Ltd.); resorcinol-type epoxy resin Denacol EX-201 (Nagase Chemical Industry Co., Ltd.); neopentyl glycol-type epoxy resin Denacol EX-211 (Nagase Chemical Industry Co., Ltd.);Examples of the epoxy resin include Denacol EX-212 (manufactured by Nagase Chemical Industries, Ltd.), which is a hexanediol glycol type epoxy resin; Denacol EX series (EX-810, 811, 850, 851, 821, 830, 832, 841, 861 (manufactured by Nagase Chemical Industries, Ltd.)), which is an ethylene-propylene glycol type epoxy resin; and EXA-4850-1000 (manufactured by Dainippon Ink and Chemicals, Inc.), and EXA-4850-150 (manufactured by Dainippon Ink and Chemicals, Inc.), which are vinyl ether type epoxy resins. Among these epoxy resins, it is preferable to use an epoxy resin having a glycidyl group.

[0035] The content of the (D) component in the resin composition is preferably 1 to 30 parts by mass relative to 100 parts by mass of the total of the (A) to (C) components. The content of the (D) component in the resin composition is more preferably 3 to 20 parts by mass, and particularly preferably 5 to 15 parts by mass, relative to 100 parts by mass of the total of the (A) to (C) components, because the electrical conductivity of the resulting cured product is increased. If the content of the (D) component is less than 1 part by mass relative to 100 parts by mass of the total of the (A) to (C) components, the effect of including the (D) component is difficult to be obtained. On the other hand, even if the content of the (D) component is more than 30 parts by mass relative to 100 parts by mass of the total of the (A) to (C) components, the effect of including the (D) component is difficult to be improved.

[0036] Next, a method for forming a cured product according to one embodiment of the present invention will be described. The method for forming a cured product according to this embodiment includes a coating step of coating the above-mentioned resin composition on a substrate, and a curing step of heating the substrate coated with the resin composition to cure the resin composition. In the curing step, it is preferable to heat the substrate coated with the resin composition at 50 to 250°C, since a cured product having better electrical conductivity can be obtained, and it is more preferable to heat the substrate at 100 to 200°C. In addition, in the curing step, it is preferable to heat the substrate coated with the resin composition for 1 to 200 minutes, and it is more preferable to heat the substrate for 10 to 60 minutes. If necessary, the method may further include a drying step of volatilizing low-boiling components such as organic solvents by keeping the substrate or the substrate coated with the resin composition at 50 to 150°C before the curing step.

[0037] In the coating step, examples of the method for coating the resin composition onto the substrate (coating method) include spin coating, dipping, spray coating, mist coating, flow coating, curtain coating, roll coating, knife coating, bar coating, slit coating, screen printing, gravure printing, offset printing, inkjet printing, brush coating, and the like.

[0038] In order to form a cured film having a required thickness, any step from the coating step to the curing step may be repeated multiple times. For example, all steps from the coating step to the curing step may be repeated multiple times, or the coating step and the drying step may be repeated multiple times.

[0039] The resin composition can be cured to obtain a cured product according to one embodiment of the present invention. Examples of applications of the cured product according to this embodiment include a conductive layer, an electrode film, and wiring. EXAMPLES

[0040] The present invention will be described in more detail below using examples and comparative examples. However, the present invention is not limited to the following examples.

[0041] <Component (A)> As component (A) (copper particles), A-1 and A-2 shown below were prepared. A-1: Granular copper particles (D 50 : 3.5μm, product name "1300Y", manufactured by Mitsui Mining & Smelting Co., Ltd.) A-2: Flake-shaped copper particles (D 50 : 3.1μm, product name "1200YP", manufactured by Mitsui Mining & Smelting Co., Ltd.)

[0042] <(B) component> As component (B) (phosphate-modified epoxy resin), B-1 and B-2 shown below were prepared. B-1: A compound obtained by reacting ADEKA Corporation's product name "EP-49-10P" (product name "ADEKA RESIN EP-4100E" (bisphenol A type epoxy resin, epoxy equivalent: 190 g / eq., manufactured by ADEKA Corporation) with phosphoric acid at 60 to 70°C; phosphoric acid modification amount: 1.0% by mass) B-2: A compound obtained by reacting ADEKA Corporation's product name "EP-49-10P2" (product name "ADEKA RESIN EP-4100E" (bisphenol A type epoxy resin, epoxy equivalent: 190 g / eq., manufactured by ADEKA Corporation) with phosphoric acid at 60 to 70°C; phosphoric acid modification amount: 1.5% by mass)

[0043] <(C) component> As the component (C) (curing agent), C-1 shown below was prepared. C-1: Imidazole compound (product name "2E4MZ", manufactured by Shikoku Chemical Industry Co., Ltd.)

[0044] <(D) component> As the component (D) (resin), the following D-1 to D-3 were prepared. D-1: Xylene resin (product name "PR-1440", manufactured by Fudow Co., Ltd.) D-2: Phenolic resin (product name "PL-2211", manufactured by Gun-ei Chemical Industry Co., Ltd.) D-3: Epoxy resin (product name "ED-509S", manufactured by ADEKA) D-4: Epoxy resin (product name "EP-4100", manufactured by ADEKA)

[0045] <Resin composition> (Examples 1 to 7, Comparative Examples 1 to 4) The components were mixed so as to obtain the compositions shown in Table 1, and Example Resin Compositions Nos. 1 to 7 and Comparative Example Resin Compositions Nos. 1 to 4 were produced.

[0046] TIFF0007662525000001.tif158170

[0047] <Production of cured product> Example resin compositions Nos. 1 to 7 and comparative resin compositions Nos. 1 to 4 were each applied to a glass substrate to a thickness of 30 μm using a bar coater method, and then baked at 150° C. for 30 minutes in air to obtain thin-film-like cured products of examples Nos. 1 to 7 and comparative cured products Nos. 1 to 4.

[0048] <Evaluation of volume resistance> (Evaluation Examples 1-7, Comparative Evaluation Examples 1-4) A high-precision resistivity meter (product name "Loresta GP", manufactured by Mitsubishi Chemical Analytech Co., Ltd.) was used to measure the volume resistivity of the cured products of the examples 1 to 7 and the cured products of the comparative examples 1 to 4 by the four-probe method. The results are shown in Table 2.

[0049] TIFF0007662525000002.tif97170

[0050] As shown in Table 2, Evaluation Examples 1 to 7 have lower volume resistivity than Comparative Evaluation Examples 1 to 4, that is, Example cured products Nos. 1 to 7 have better conductivity than Comparative Example cured products 1 to 4. Among Evaluation Examples 1 to 7, Evaluation Examples 1 to 6 have even lower volume resistivity, and Evaluation Examples 1, 4, and 6 have particularly low volume resistivity. From the above results, it can be seen that the conductivity of the resulting cured product is particularly improved by (i) further containing component (D) in addition to components (A) to (C); and (ii) containing both granular copper particles and flake-shaped copper particles as component (A). From the above, it is clear that the cured product obtained by curing the resin composition of this embodiment has excellent conductivity.

Claims

1. (A) copper particles having an average particle size of 0.1 to 20 μm; (B) a phosphoric acid-modified epoxy resin obtained by reacting a phosphoric acid (b1) with an epoxy compound (b2), and (C) containing a curing agent, the content of the (B) component is 0.1 to 30 parts by mass and the content of the (C) component is 0.1 to 5 parts by mass, relative to 100 parts by mass of the total amount of the (A) to (C) components; The component (A) contains both granular copper particles and flaky copper particles, The content of the granular copper particles is 75 to 95 parts by mass relative to 100 parts by mass of the total amount of the component (A), The resin composition has a content of the flake-like copper particles of 5 to 25 parts by mass relative to 100 parts by mass of the total amount of the component (A).

2. Further, the composition contains at least one resin selected from the group consisting of (D) xylene resin, phenol resin, and epoxy resin (excluding the (B) component), 2. The resin composition according to claim 1, wherein the content of the component (D) is 1 to 30 parts by mass relative to 100 parts by mass of the total amount of the components (A) to (C).

3. A resin composition as described in claim 2, wherein the phenolic resin is a resol type phenolic resin.

4. A coating step of coating a substrate with the resin composition according to any one of claims 1 to 3; and a curing step of heating the substrate to which the resin composition has been applied to cure the resin composition.

5. The method for forming a cured product according to claim 4, wherein the substrate coated with the resin composition is heated at 50 to 250° C. for 1 to 200 minutes.

6. A cured product obtained by curing the resin composition according to any one of claims 1 to 3.

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