Conductive resin composition and cured product thereof

Abstract

The purpose of the present invention is to provide a conductive resin composition which can be cured at room temperature (5-50 DEG C) and which can be cured into a cured product having excellent conductivity. The conductive resin composition contains an epoxy resin as a component (A), a spine-shaped conductive filler as a component (B), and a curing agent for an epoxy resin as a component (C).

Description

Technical Field

[0001] The present invention relates to a conductive resin composition and a cured product thereof. Background Art

[0002] Conventional heat-curable epoxy-based conductive adhesives are widely used in the manufacture of motors and electronic components due to their excellent bonding properties and heat resistance. However, in order to exhibit excellent conductivity, high-temperature heating of at least about 150° C. is required.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2010-037389 Summary of the invention

[0006] However, in recent years, energy-saving production lines that eliminate heat source processes have been developed in manufacturing sites of electronic components and the like, and the above-mentioned heat-curable epoxy-based conductive adhesive cannot be applied.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a conductive resin composition that cures at room temperature (5 to 50° C.) and whose cured product has excellent conductivity.

[0008] The gist of the present invention is described below.

[0009] [1] A conductive resin composition comprising an epoxy resin as component (A), a spike-shaped conductive filler as component (B), and a curing agent for the epoxy resin as component (C).

[0010] [2] The conductive resin composition according to [1], comprising the following agent A and agent B.

[0011] Agent A: a composition containing an epoxy resin as component (A) and a spike-shaped conductive filler as component (B); and

[0012] Agent B: A composition containing a curing agent for epoxy resin as the component (C).

[0013] [3] The conductive resin composition according to [1] or [2], wherein the component (B) is a spike-like nickel filler.

[0014] [4] The conductive resin composition according to any one of [1] to [3], wherein the component (A) contains at least a glycidylamine resin.

[0015] [5] The conductive resin composition according to any one of [1] to [4], further comprising a polyfunctional radical polymerizable compound as component (D).

[0016] [6] The conductive resin composition according to any one of [1] to [5], wherein the component (C) is liquid at 25°C.

[0017] [7] The conductive resin composition according to any one of [1] to [6], which does not contain a peroxide.

[0018] [8] The conductive resin composition according to any one of [1] to [7], comprising 100 to 1000 parts by mass of the component (B) based on 100 parts by mass of the component (A).

[0019] [9] A cured product obtained by curing the conductive resin composition according to any one of [1] to [8]. DETAILED DESCRIPTION

[0020] The invention will be described in detail below. It should be noted that in this specification, "X to Y" is used to include the numerical values ​​(X and Y) described before and after as lower limits and upper limits, and means "X or more and Y or less".

[0021] A conductive resin composition according to one embodiment of the present invention is a conductive resin composition comprising an epoxy resin as component (A), a spike-shaped conductive filler as component (B), and a curing agent for epoxy resin as component (C). The conductive resin composition according to the present invention cures at room temperature (5 to 50° C.), and its cured product can have excellent conductivity.

[0022] <(A)Component>

[0023] If the component (A) used in the present invention is an epoxy resin, it can be used without particular limitation. As the component (A), for example, an epoxy resin (a1) having 2 or more and less than 3 (preferably 2) epoxy groups in one molecule, a multifunctional epoxy resin (a2) having 3 or more and less than 10 (preferably 3 or more and 9 or less) epoxy groups in one molecule, etc. can be cited. In the present invention, the component (A) can use the component (a1) and the component (a2) at the same time. It should be noted that when the conductive resin composition contains two or more components (A) (for example, (a1) and (a2)), the content of the component (A) refers to the total amount of these. In addition, the adhesive described later is not included in the component (A) and is regarded as an optional component.

[0024] The component (A) can be used in either a liquid or solid state at 25°C, but is preferably in a liquid state at 25°C from the viewpoint of being easy to handle. It should be noted that the easy to handle means that the conductive resin composition has a low viscosity and is easy to apply. In this specification, the liquid state means a substance having a viscosity of 0.01 mPa·s to 1000 Pa·s measured by a cone-plate viscometer at 25°C.

[0025] The component (a1) is not particularly limited, and examples thereof include bisphenol-type epoxy resins such as bisphenol A epoxy resin, bisphenol F epoxy resin, bisphenol S epoxy resin, and bisphenol AD ​​epoxy resin, hydrogenated bisphenol-type epoxy resin, alkylene glycol-type epoxy resins such as 1,2-butanediol diglycidyl ether, 1,3-butanediol diglycidyl ether, 1,4-butanediol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, 2,3-butanediol diglycidyl ether, 1,5-pentanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, and 1,4-cyclohexanedimethanol diglycidyl ether, and glycidylamine resins such as N,N-bis(2,3-epoxypropyl)o-toluidine. These components (a1) may be used alone or in combination of two or more. Among these, from the viewpoint of excellent curability and excellent conductivity at room temperature, the component (a1) preferably contains a bisphenol epoxy resin, and more preferably contains both a bisphenol A epoxy resin and a bisphenol F epoxy resin. In addition, from the viewpoint of excellent curability at room temperature, the component (a1) preferably contains a glycidylamine resin, and more preferably contains both a bisphenol epoxy resin and a glycidylamine resin. By having the above-mentioned component (a1), a conductive resin composition that is further cured at room temperature and whose cured product has excellent conductivity can be obtained. In addition, the component (a1) preferably contains a difunctional bisphenol epoxy resin, and more preferably contains a difunctional bisphenol A epoxy resin and a difunctional bisphenol F epoxy resin, and particularly preferably contains a difunctional bisphenol A epoxy resin, a difunctional bisphenol F epoxy resin, and a difunctional glycidylamine resin.

[0026] When the component (a1) includes a bisphenol A epoxy resin and a bisphenol F epoxy resin, the mass ratio of the bisphenol A epoxy resin (when two or more types are included, the total amount thereof) to the bisphenol F epoxy resin (when two or more types are included, the total amount thereof) in the component (a1) is not particularly limited. The content of the bisphenol F epoxy resin is, for example, 10 to 300 parts by mass, more preferably 30 to 200 parts by mass, and particularly preferably 50 to 150 parts by mass relative to 100 parts by mass of the bisphenol A epoxy resin.

[0027] When the component (a1) includes a bisphenol epoxy resin and a glycidylamine resin, the mass ratio of the bisphenol epoxy resin (when two or more types are included, the total amount thereof) to the glycidylamine resin (when two or more types are included, the total amount thereof) in the component (a1) is not particularly limited. The glycidylamine resin is, for example, 10 to 200 parts by mass, more preferably 20 to 150 parts by mass, and particularly preferably 30 to 120 parts by mass relative to 100 parts by mass of the bisphenol epoxy resin.

[0028] The component (a2) is not particularly limited, and examples thereof include novolac epoxy resins such as phenol novolac epoxy resins and cresol novolac epoxy resins; glycidylamine compounds such as N,N-diglycidyl-4-glycidyloxyaniline, 4,4'-methylenebis(N,N-diglycidylaniline), tetraglycidyldiaminodiphenylmethane, and tetraglycidyl-m-xylylenediamine; naphthalene epoxy resins having four glycidyl groups; glycidylamine resins such as triglycidyl-p-aminophenol, etc. These components (a2) may be used alone or in combination of two or more.

[0029] Here, as the component (a2), a polyfunctional epoxy resin having 3 or more and less than 9 (or 3 or more and less than 8) epoxy groups in one molecule is preferred, a polyfunctional epoxy resin having 3 or more and less than 8 (or 3 or more and less than 7) epoxy groups in one molecule is more preferred, a polyfunctional epoxy resin having 3 or more and less than 7 (or 3 or more and less than 6) epoxy groups in one molecule is further preferred, a polyfunctional epoxy resin having 3 or more and less than 6 (or 3 or more and less than 5) epoxy groups in one molecule is particularly preferred, and a polyfunctional epoxy resin having 3 epoxy groups in one molecule is most preferred.

[0030] When the component (A) includes the components (a1) and (a2), the mass ratio ((a1) / (a2)) of the components (a1) and (a2) is not particularly limited, but is preferably in the range of 20 / 80 to 90 / 10, more preferably in the range of 30 / 70 to 85 / 15, still more preferably in the range of 40 / 60 to 80 / 20, and particularly preferably in the range of 50 / 50 to 70 / 30. By setting the above range, a conductive resin composition that is further cured at room temperature and whose cured product has excellent conductivity can be obtained.

[0031] There are no particular limitations on commercially available products of the component (A), and examples thereof include jER (registered trademark) 828, 827, 1001, 801, 806, 807, 152, 604, 630, 871, YX8000, YX8034, and YX4000 (all manufactured by Mitsubishi Chemical Corporation); EPICLON 830, 850, 830LVP, 850CRP, 835LV, HP4032D, 703, 720, 726, 820 (all manufactured by DIC Corporation); EP4100, EP4000, EP4080, EP4085, EP4088, EPU6, EPU7N, EPR4023, EPR1309, EP4920 (all manufactured by ADEKA Corporation), TEPIC (registered trademark) (all manufactured by Nissan Chemical Industries, Ltd.); KF-101, KF-1001, KF-105, X-22-163B, X-22-9002 (all manufactured by Shin-Etsu Chemical Co., Ltd.); DENACOL (registered trademark) EX411, 314, 201, 212, 252 (all manufactured by Nagase ChemteX Co., Ltd.); DER-331, 332, 334, 431, 542 (all manufactured by Dow Chemical); YH-434, YH-434L (all manufactured by NIPPONSTEEL Chemical & Material Co., Ltd.); GOT (all manufactured by Nippon Kayaku Co., Ltd.), etc.

[0032] <(B) Ingredient>

[0033] The (B) component of the present invention, i.e., the spike-shaped conductive filler, can provide a conductive resin composition that cures at room temperature and has excellent conductivity by combining with the (A) component and the (C) component of the present invention. As the above-mentioned (B) component, for example, metal powders such as nickel, gold, platinum, silver, copper, palladium, alloys such as solders formed by combining these in various ways, organic polymer particles, and plated particles in which other metal films are coated on metal particles. These (B) components can be used alone or in combination of two or more. It should be noted that when the conductive resin composition contains two or more (B) components, the content of the (B) component refers to their total amount. Among them, from the aspect of being able to achieve low resistance, as the (B) component, gold, silver, copper, and nickel are preferred. Particularly preferred (B) component is nickel. Here, the spike-shaped refers to a shape having sharp protrusions on the surface of the primary particle, and there are multiple (usually 3 to 500) conical protrusions with a height of 1 / 3 to 1 / 50 of the particle diameter on one particle. In addition, the (B) component can be surface-treated with a lubricant. As the lubricant, a saturated fatty acid or / and an unsaturated fatty acid can be used. As the lubricant, for example, capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, heptadecanoic acid, stearic acid, linolenic acid, linoleic acid, palmitoleic acid, oleic acid, etc. can be mentioned. These lubricants can be used alone or in combination of two or more.

[0034] The average particle size of the above-mentioned component (B) is not particularly limited, and is, for example, 0.01 to 150 μm, preferably 0.1 to 50 μm, and particularly preferably 1 to 13 μm. By being within the above-mentioned range, it is preferred in that a conductive resin composition having further excellent conductivity can be obtained. The above-mentioned average particle size is the particle size (D50) at a cumulative volume ratio of 50% in the particle size distribution obtained by a laser diffraction scattering method. As an example, the average particle size is measured using a laser diffraction scattering shape distribution measuring instrument. The apparent density of the above-mentioned component (B) is not particularly limited, and is, for example, 0.5 to 10 g / cm 3 , preferably 1.0 to 5.0 g / cm 3 , particularly preferably 1.5 to 3.5 g / cm 3 The above range is preferred in that a conductive resin composition having further excellent conductivity can be obtained. The test method for the above apparent density is in accordance with JIS Z2504:2020.

[0035] The content of the component (B) contained in the conductive resin composition as a whole is not particularly limited, and is, for example, 10 to 95% by mass, preferably 30 to 90% by mass, more preferably 50 to 85% by mass, and particularly preferably 70 to 82% by mass. Within the above range, a conductive resin composition that is further cured at room temperature and has excellent conductivity can be obtained. In addition, relative to 100 parts by mass of the above-mentioned (A) component, the content of the above-mentioned (B) component is 100 to 1000 parts by mass, more preferably 200 to 900 parts by mass, and particularly preferably 300 to 700 parts by mass. Within the above range, a conductive resin composition that is further cured at room temperature and has excellent conductivity can be obtained.

[0036] The component (B) can be obtained from the market. For example, Ni powder type 123 manufactured by Vale can be used.

[0037] <(C) Ingredients>

[0038] The component (C) used in the present invention is a curing agent for epoxy resin. From the viewpoint of room temperature curability, the component (C) is preferably an amine compound that is liquid at a temperature of 25°C. Specific examples of the component (C) include aliphatic polyamines, alicyclic polyamines, aromatic polyamines, secondary amines, tertiary amines, polyamide amines, and amine compounds in which the amine groups are modified at the ends of high molecular weight bodies. These components (C) can be used alone or in combination of two or more. From the perspective of obtaining a conductive resin composition that cures at room temperature and has excellent conductivity, the component (C) preferably contains an amine compound having an amine value of 400KOHmg / g or more, and more preferably contains only a curing agent selected from an amine compound having an amine value of 400KOHmg / g or more and a tertiary amine. It should be noted that when the conductive resin composition contains two or more components (C), the content of the component (C) refers to their total amount. In addition, the adhesive described later is not included in the component (C) and is regarded as an optional component.

[0039] Specific examples of aliphatic polyamines include, but are not limited to, ethylenediamine, diethylenetriamine, triethylenetetramine, hexamethylenediamine, etc. Specific examples of alicyclic polyamines include, but are not limited to, mensanediamine (MDA), isophoronediamine (IPDA), N-aminoethylpiperazine (N-AEP), diaminodicyclohexylmethane, norbornanediamine (NBDA), etc. Specific examples of aromatic polyamines include, but are not limited to, meta-phenylenediamine (MXDA), meta-phenylenediamine, diaminodiphenylmethane, diaminodiphenylsulfone, diaminodiethyldiphenylmethane, etc. Specific examples of secondary or tertiary amines include, but are not limited to, piperidine, pyridine, benzyldimethylamine, dimethylaminomethylphenol, 2,4,6-tris(dimethylaminomethyl)phenol, triethylenediamine, dimethylcyclohexylamine, dimethylbenzylamine, dimethylhexylamine, dimethylaminophenol, dimethylamino-p-cresol, 1,4-diazabicyclo〔2.2.2〕octane, 1,8-diazabicyclo〔5.4.0〕undecene-1, etc. Specific examples of amine compounds having amino groups modified at the ends of high molecular weight bodies include, but are not limited to, amino-terminated butadiene-acrylonitrile copolymers, amino-terminated (meth)acrylic (co)polymers, amino-terminated polyether polymers, and amino-terminated polyester polymers. It is preferred that the component (C) contains a tertiary amine in order to obtain a conductive resin composition that is further cured at room temperature and has excellent conductivity. Examples of the tertiary amine include 2,4,6-tris(dimethylaminomethyl)phenol and dimethylaminomethylphenol, and 2,4,6-tris(dimethylaminomethyl)phenol is most preferred.

[0040] Examples of commercially available products of (C) include ANCAMINE 1110, ANCAMINE K54, ANCAMINE K618, and ANCAMINE 2709 manufactured by EVONIC, Fujicure (registered trademark) 4011, 4025, 4030, 7000, 7001, 7002, 8121, Tohmide 235-A, and 235-R manufactured by T&K TOKA, EH-451N manufactured by ADEKA Corporation, Hypro ATBN 1300X16 manufactured by Huntsman, and ST11, ST12, ST14, ST15, and LV11 manufactured by Mitsubishi Chemical Corporation.

[0041] When two or more of the above-mentioned (C) components are included, from the viewpoint of excellent curability at room temperature, the mass ratio of the alicyclic polyamine: the aliphatic polyamine is preferably 20:80 to 80:20, and more preferably 30:70 to 70:30. The aliphatic polyamine: the polyamide amine is preferably 95:5 to 50:50, and more preferably 90:10 to 70:30. The polyamide amine: the amine compound in which the amino group is modified at the terminal of the polymer is preferably 90:10 to 20:80, and more preferably 80:20 to 50:50. In addition, from the viewpoint of excellent curability at room temperature, the content of the tertiary amine is preferably 1 to 20% by mass, more preferably 2 to 10% by mass, and most preferably 3 to 10% by mass relative to the total amount of the (C) component.

[0042] The amount (content) of the component (C) is preferably 5 to 200 parts by mass, more preferably 10 to 150 parts by mass, and most preferably 20 to 110 parts by mass relative to 100 parts by mass of (A). Within the above range, a conductive resin composition that is further cured at room temperature and has excellent conductivity can be obtained.

[0043] <(D) Ingredient>

[0044] The conductive resin composition of the present invention may further contain a multifunctional free radical polymerizable compound as the (D) component. The (D) component used in the present invention, i.e., the multifunctional free radical polymerizable compound, is not particularly limited as long as it is a compound having two or more free radical polymerizable functional groups in the molecule. The (D) component can provide a conductive resin composition that is further cured at room temperature and has excellent conductivity by combining with the (A) to (C) components of the present invention. There are no particular restrictions on the free radical polymerizable functional groups of the above-mentioned (D) component, and examples thereof include ethylenically unsaturated groups such as (meth)acryloyl, allyl, and vinyl. As the above-mentioned (D) component, compounds commonly used in adhesives and coatings can be used. Specifically, for example, as the (D) component, a difunctional or higher multifunctional (meth)acrylate (multifunctional (meth)acrylate compound) can be used. These (D) components can be used alone or in combination of two or more. It should be noted that when the conductive resin composition contains two or more (D) components, the content of the (D) component refers to their total amount. Among them, from the viewpoint of obtaining a conductive resin composition that is further cured at room temperature and has excellent conductivity, the component (D) preferably contains a trifunctional or higher (meth)acrylate. The component (D) is more preferably a (meth)acrylate having an aliphatic hydrocarbon skeleton, and most preferably trimethylolpropane tri(meth)acrylate. In addition, the binder described later is not included in the component (D) and is considered an optional component.

[0045] It should be noted that in this specification, acryloyl and methacryloyl are collectively referred to as (meth)acryloyl. In addition, in this specification, (meth)acrylate refers to both acrylate and methacrylate. Also, compounds containing (meth) such as (meth)acrylic acid are also a general term for compounds having "methyl" in the name and compounds without "methyl".

[0046] The difunctional (meth)acrylate is not particularly limited, and examples thereof include ethylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, glycerol di(meth)acrylate, neopentyl glycol di(meth)acrylate, stearic acid-modified pentaerythritol di(meth)acrylate, dicyclopentenyl di(meth)acrylate, di(meth)acryloyl isocyanurate, alkylene oxide-modified bisphenol di(meth)acrylate, epoxy di(meth)acrylate, urethane di(meth)acrylate, polyisobutylene di(meth)acrylate, and acrylic polymers containing a di(meth)acryloyl group. Among these, the difunctional (meth)acrylate is preferably epoxy di(meth)acrylate or urethane di(meth)acrylate. The above-mentioned carbamate di(meth)acrylate is not particularly limited, and examples thereof include carbamate di(meth)acrylate with a polybutadiene skeleton, carbamate di(meth)acrylate with a hydrogenated polybutadiene skeleton, carbamate di(meth)acrylate with a polycarbonate skeleton, carbamate di(meth)acrylate with a polyether skeleton, and carbamate di(meth)acrylate with a polyester skeleton. These difunctional (meth)acrylates can be used alone or in combination of two or more.

[0047] The trifunctional (meth)acrylate is not particularly limited, and examples thereof include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, tri(acryloyloxyethyl)isocyanurate, etc. These trifunctional (meth)acrylates may be used alone or in combination of two or more.

[0048] As tetrafunctional or higher (meth) acrylate, there is no particular limitation, and examples thereof include ditrimethylolpropane tetra(meth) acrylate, pentaerythritol tetra(meth) acrylate, dipentaerythritol monohydroxy penta(meth) acrylate, alkyl-modified dipentaerythritol penta(meth) acrylate, dipentaerythritol hexa(meth) acrylate, urethane tetra(meth) acrylate, urethane hexa(meth) acrylate, etc. Among these, tetrafunctional or higher (meth) acrylate is preferably dipentaerythritol hexa(meth) acrylate. These tetrafunctional or higher (meth) acrylates can be used alone or in combination of two or more.

[0049] There are no particular limitations on commercially available products of the component (D), and examples thereof include NK Ester A-NPG, 701A, A-200, A-DCP, ABE-10, A-TMPT, A-9300, A-TMM-3, A-TMMT, AD-TMP, A-DPH, A-9550, TPOA-50, NPG, 701, 14G, 23G, DCP, TMPT, BPE-80N manufactured by Shin-Nakamura Chemical Industry Co., Ltd. and KAYARAD DPHA manufactured by Nippon Kayaku Co., Ltd. These may be used alone or in combination of two or more.

[0050] The addition amount (compounding amount, content) of the above-mentioned (D) component is not particularly limited, and is preferably 1 to 50 parts by mass, more preferably 2 to 40 parts by mass, and particularly preferably 3 to 30 parts by mass relative to 100 parts by mass of the (A) component. Within the above range, a conductive resin composition that is further cured at room temperature and has excellent conductivity can be obtained. In addition, relative to 100 parts by mass of the above-mentioned (C) component, the content of the above-mentioned (D) component is preferably 1 to 50 parts by mass, particularly preferably 2 to 40 parts by mass, and 3 to 30 parts by mass. Within the above range, a conductive resin composition that is further cured at room temperature and has excellent conductivity can be obtained.

[0051] <Optional Ingredients>

[0052] The conductive resin composition of the present invention may contain additives such as conductive fillers, monofunctional radical polymerizable compounds, non-conductive fillers, binders, curing accelerators, storage stabilizers, antioxidants, light stabilizers, plasticizers, pigments, flame retardants, and surfactants other than the component (B) of the present invention, within the range not impairing the purpose of the present invention. It should be noted that the conductive resin composition of the present invention preferably does not contain an organic peroxide or a photoradical polymerization initiator from the viewpoint of storage stability.

[0053] If the conductive filler of the (B) component not involved in the present invention embodies conductivity, the material of the particles, the shape of the particles, etc. are not limited. The conductive filler of the non-(B) component can include, for example, metal particles composed of one or more metals selected from gold, silver, copper, nickel, palladium, platinum, tin, bismuth, iron, etc., alloys such as solders formed by combining these in a variety of ways, organic polymer particles, and plated particles coated with other metal films on metal particles. These conductive fillers of non-(B) components can be used alone, or two or more can be used in combination. As the shape of the conductive filler of the non-(B) component, spherical, amorphous, flaky (scaly), plate-like, filamentous, dendritic, etc. (except spikes) can be mentioned. These can be used alone, or two or more can be used in combination. In addition, the conductive filler of the non-(B) component can be surface treated with a lubricant. As a lubricant, a saturated fatty acid and / or an unsaturated fatty acid can be used. Examples of the lubricant include capric acid, undecanoic acid, lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, heptadecanoic acid, stearic acid, linolenic acid, linoleic acid, palmitoleic acid, and oleic acid. These lubricants may be used alone or in combination of two or more.

[0054] For the conductive resin composition of the present invention, a non-conductive filler can be added to the extent that the storage stability is not impaired in order to improve the elastic modulus and fluidity of the cured product. Specifically, non-conductive fillers include glass, fumed silica, alumina, mica, ceramics, silicone rubber powder, calcium carbonate, aluminum nitride, carbon powder, kaolin clay, dry clay minerals, dry diatomaceous earth, etc. The amount (content) of the non-conductive filler is preferably about 0.1 to 100 parts by mass relative to 100 parts by mass of the above-mentioned (A) component.

[0055] The fumed silica can be matched for the purpose of adjusting the viscosity of the conductive resin composition of the present invention or improving the mechanical strength of the cured product of the present invention. As the fumed silica, it is preferred to use fumed silica etc. that has been hydrophobized with organochlorosilanes, polyorganosiloxanes, hexamethyldisilazane, etc. As a specific example of fumed silica, commercial products such as trade names Areosil R974, R972, R972V, R972CF, R805, R812, R812S, R816, R8200, RY200, RX200, RY200S, R202, etc., made by Japan Aerosil Co., Ltd., can be cited.

[0056] The conductive resin composition of the present invention may be added with a binder. Examples of the binder include aluminate coupling agents, 3-methacryloxypropylmethyldimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-methacryloxypropylmethyldiethoxysilane, 3-methacryloxypropyltriethoxysilane, 3-acryloxypropyltrimethoxysilane, methacryloxyoctyltrimethoxysilane, vinyltrimethoxysilane, vinyltrichlorosilane, vinyltriethoxysilane, vinyl-tri(β-methoxyethoxy)silane, γ-chloropropyltrimethoxysilane, β-(3 , 4-epoxycyclohexyl)ethyl trimethoxysilane, γ-glycidyloxypropyl trimethoxysilane, γ-mercaptopropyl trimethoxysilane, γ-aminopropyl triethoxysilane, N-β-(aminoethyl)-γ-aminopropyl trimethoxysilane, N-β-(aminoethyl)-γ-aminopropyl methyl dimethoxysilane, γ-ureidopropyl triethoxysilane, hydroxyethyl methacrylate phosphate, methacryloyloxyoxyethyl acid phosphate, methacryloyloxyoxyethyl acid phosphate monoethylamine half salt, 2-hydroxyethyl methacrylate phosphate, etc. The content of the binder is preferably 0.05 to 30 parts by mass, more preferably 1 to 15 parts by mass, and particularly preferably 3 to 10 parts by mass relative to 100 parts by mass of the component (A).

[0057] <Manufacturing method>

[0058] The conductive resin composition of the present invention can be produced by a conventionally known method. For example, it can be produced by mixing the components (A) to (C), the component (D) as required, and the predetermined amounts of the optional components, preferably at a temperature of 10 to 70° C. for 0.1 to 5 hours using a mixing device such as a mixer.

[0059] <Two-component conductive resin composition>

[0060] In one embodiment, the conductive resin composition of the present invention is a two-component conductive resin composition containing an agent A and an agent B, wherein the agent A is a composition containing the above-mentioned (A) component and the (B) component, and the agent B is a composition containing the above-mentioned (C) component. Preferably, the agent A is a composition containing the above-mentioned (A) component and the (B) component, and the agent B is a composition containing the above-mentioned (C) component and the (B) component. By separating the components into separate liquids in this way, unnecessary reactions can be suppressed during storage, and storage stability can be improved. In such a two-component conductive resin composition, the agent A and the agent B can also be manufactured by mixing the components using a known method. And, when used, the agent A and the agent B are mixed for use. It should be noted that the content of the agent B is 5 to 300 parts by mass relative to 100 parts by mass of the agent A, more preferably 10 to 200 parts by mass, and particularly preferably 20 to 150 parts by mass. The above-mentioned agent A and agent B can be cured by mixing and stirring the two before use.

[0061] The two-component conductive resin composition according to one embodiment of the present invention may contain the above-mentioned component (B) in both agent A and agent B. In this case, the mass ratio of the component (B) contained in agent A to the component (B) contained in agent B is preferably 90:10 to 10:90, more preferably 80:20 to 25:75, and most preferably 75:25 to 40:60. If it is in the range of 90:10 to 10:90, the workability during mixing of the two components is excellent, and a cured product with excellent conductivity can be obtained.

[0062] When the two-component conductive resin composition according to one embodiment of the present invention contains the component (D), it is preferably contained at least in agent A, and more preferably contained only in agent A. By containing the component (D) in agent A, curing at room temperature is further possible.

[0063] The above-mentioned A agent is a composition containing (A) component and (B) component, and the amount (content) of (B) component is preferably 100-1000 mass parts relative to 100 mass parts of (A) component, more preferably 200-700 mass parts, and most preferably 300-500 mass parts. In addition, when (D) component is included, relative to 100 mass parts of (A) component, the amount (content) of (B) component is preferably 100-1000 mass parts, and the amount (content) of (D) component is 1-50 mass parts, more preferably the amount (content) of (B) component is 200-700 mass parts, and the amount (content) of (D) component is 2-40 mass parts, and the most preferably the amount (content) of (B) component is 300-500 mass parts, and the amount (content) of (D) component is 3-30 mass parts.

[0064] The above-mentioned agent B is a composition containing the component (C) and, if necessary, the component (B), and the blending amount (content) of the component (B) is preferably 100 to 1000 parts by mass, more preferably 200 to 700 parts by mass, and most preferably 300 to 500 parts by mass relative to 100 parts by mass of the component (C).

[0065] <Curing method and cured product>

[0066] The cured product obtained by curing the conductive resin composition of the present invention is also an embodiment of the present invention. In addition, the curing conditions of the conductive resin composition are not particularly limited, for example, 5 to 50°C. The curing time is not particularly limited, preferably 1 hour to 20 days, more preferably 6 hours to 10 days, and particularly preferably 12 hours to 5 days. In addition, the cured product obtained by curing the two-component conductive resin composition involved in one embodiment of the present invention is also an embodiment of the invention. Curing based on two-component mixing means that it can be cured by mixing two liquids when used. In addition, the curing conditions of the two-component conductive resin composition are not particularly limited, for example, 5 to 50°C. The curing time is not particularly limited, preferably 1 hour to 20 days, more preferably 6 hours to 10 days, and particularly preferably 12 hours to 5 days. It should be noted that the conductive resin composition of the present invention can be further cured by heating at 50 to 150°C.

[0067] <Coating method>

[0068] As a method for applying the conductive resin composition of the present invention to an adherend, for example, dispensing using an automatic coater, spraying, inkjetting, screen printing, gravure printing, dip coating, spin coating, etc. can be used. It should be noted that the conductive resin composition of the present invention is preferably liquid at a temperature of 25° C. from the viewpoint of coating properties.

[0069] <Application>

[0070] The conductive resin composition of the present invention can be used for conductive adhesives and grounding required around liquid crystal image display elements, organic EL elements, solar cell elements, camera modules, flexible printed circuit boards, wearable devices, battery packs, etc., since it can obtain a cured product that cures at room temperature (5 to 50° C.) and has excellent conductivity.

[0071] Example

[0072] The present invention will be further described in detail with reference to the following examples, but the present invention is not limited to these examples. In addition, unless otherwise specified, the operation test was carried out under an environment of 25° C. and 55% RH.

[0073] <Preparation of Conductive Resin Composition>

[0074] The components were collected in parts by mass as shown in Table 1, and mixed in a mixer at room temperature for 60 minutes to prepare the A agent and B agent contained in the conductive resin composition. It should be noted that the detailed preparation amount is in accordance with Table 1, and all the values ​​are described in parts by mass. Hereinafter, the conductive resin composition is also referred to as the "composition", and the cured product after curing the composition is also referred to as the "cured product".

[0075] <(A)Component>

[0076] a1-1: Bifunctional bisphenol A type epoxy resin (liquid (viscosity (25°C): 13 Pa·s) jER828 manufactured by Mitsubishi Chemical Corporation)

[0077] a1-2: Bifunctional bisphenol A type epoxy resin (liquid (viscosity (25°C): 10 Pa·s) jER827 manufactured by Mitsubishi Chemical Corporation)

[0078] a1-3: Bifunctional bisphenol F type epoxy resin (liquid (viscosity (25°C): 2 Pa·s) jER806 manufactured by Mitsubishi Chemical Corporation)

[0079] a1-4: difunctional glycidylamine resin (N,N-bis(2,3-epoxypropyl)o-toluidine liquid (viscosity (25°C): 50 mPa·s) GOT manufactured by Nippon Kayaku Co., Ltd.)

[0080] a2-1: trifunctional glycidylamine resin (triglycidyl p-aminophenol liquid (viscosity (25°C): 750 mPa·s) jER630 manufactured by Mitsubishi Chemical Corporation)

[0081] <(B) Components and comparative components>

[0082] b1: average particle size 3.7 μm, apparent density 2.1 g / cm 3 Spiky nickel filler (Ni powder type 123 manufactured by Vale)

[0083] b'1: average particle size 2.5 μm, apparent density 0.58 g / cm 3 Nickel wire filler (Ni powder type 255 manufactured by Vale)

[0084] b'2: average particle size 15 μm, apparent density 1.1 g / cm 3 Nickel flake filler (Ni powder type HCA-1 manufactured by Vale)

[0085] b'3: average particle size 19 μm, apparent density 4.2 g / cm 3Spherical nickel filler (Ni powdertype SNP+20 manufactured by Vale)

[0086] <(C) Ingredients>

[0087] c1: modified alicyclic polyamine (amine value: 405 KOHmg / g liquid (viscosity (25°C): 200 mPa·s) Fujicure 8121 manufactured by T&K TOKA Co., Ltd.)

[0088] c2: Modified aliphatic polyamine (amine value: 420 KOHmg / g liquid (viscosity (25°C): 400 mPa·s) EH-451N manufactured by ADEKA Corporation)

[0089] c3: Polyamidoamine (amine value: 390 KOHmg / g, liquid (viscosity (25°C): 13 Pa·s), Fujicure 235-A manufactured by T&KTOKA Co., Ltd.)

[0090] c4: Polyamidoamine (amine value: 410 KOHmg / g, liquid (viscosity (25°C): 3 Pa·s), Tohmide 235-R manufactured by T&K TOKA Co., Ltd.)

[0091] c5: amino-terminated butadiene-acrylonitrile copolymer (amine value: 62000 KOHmg / g, liquid (viscosity (25°C): 200 Pa·s), Hypro ATBN 1300X16 manufactured by HUNTSMAN)

[0092] c6: tertiary amine (liquid tris-2,4,6-dimethylaminomethylphenol (viscosity (25°C): 200 mPa·s) Ancamine K-54 manufactured by EVONIC Corporation)

[0093] <(D) Ingredient>

[0094] d1: a polyfunctional radical polymerizable compound (trimethylolpropane triacrylate, NK Ester A-TMPT manufactured by Shin-Nakamura Chemical Co., Ltd.).

[0095] The test methods used in the examples and comparative examples in Table 1 are as follows.

[0096] <Connection resistance measurement>

[0097] Prepare the agent A and agent B of the embodiment and comparative example of Table 1, and prepare a composition obtained by mixing 100 parts by mass of agent B with respect to 100 parts by mass of agent A. Next, for an aluminum plate with a width of 25 mm × a length of 100 mm × a thickness of 1.6 mm, a masking tape is pasted in a manner that exposes a width of 10 mm × a length of 50 mm × a thickness of 250 μm. Thereafter, the above composition is scraped. Then, the masking tape is peeled off, a spacer with a thickness of 200 μm is clamped, and the aluminum plate not coated with the composition is bonded from above. Use a pressure head to press 4 places around the bonding part, let it stand at 25°C for 24 hours, and then release the pressure head as a test piece. Make 3 of the above test pieces, make the needle-shaped electrodes of the dual-display multimeter contact the upper and lower aluminum plates respectively to measure the resistance, and take the average value as the "connection resistance value (Ω) after 24 hours".

[0098] In addition, the above operation is repeated, and the resistance produced by releasing the pressure head after 48 hours is measured as the "connection resistance value (Ω) after 48 hours". It should be noted that in this specification, the connection resistance value after 24 hours is preferably less than 100Ω, more preferably less than 50Ω, and particularly preferably less than 30Ω. The connection resistance value after 48 hours is preferably less than 10Ω, more preferably less than 1Ω, and particularly preferably less than 0.5Ω. In addition, the insulation indication is at the upper limit of the measurement of the dual-display multimeter and cannot be measured. It should be noted that the connection resistance value refers to the virtually measured resistance value generated between the cured product and the adherend, which is different from the volume resistivity of the resistance value as a single substance of the cured product.

[0099] [Table 1]

[0100]

[0101] Examples 1 to 4 in Table 1 respectively use the same (B) component but change the types of (A) component and (C) component. As shown in Table 1, it can be seen that the compositions of Examples 1 to 4 cure at room temperature and their cured products have excellent conductivity. In contrast, Comparative Example 1 uses a filamentous nickel filler instead of the (B) component of Example 2, and it can be seen that the connection resistance values ​​after 24 hours and 48 hours become higher. In addition, Comparative Example 2 uses a flake nickel filler instead of the (B) component of Example 2, and it can be seen that the connection resistance values ​​after 24 hours and 48 hours become higher. In addition, Comparative Example 3 uses a spherical nickel filler instead of the (B) component of Example 2, and it can be seen that the connection resistance values ​​after 24 hours and 48 hours are high, exceeding the upper limit of the measurement of the dual-display multimeter.

[0102] Industrial Applicability

[0103] The present invention is a conductive resin composition that cures at room temperature and has excellent conductivity, and thus can be used in various conductive paste applications and is effective, and therefore is industrially useful.

[0104] This application is based on Japanese Patent Application No. 2022-095628 filed on June 14, 2022, the disclosed contents of which are incorporated herein by reference in their entirety.

Claims

1. A conductive resin composition comprising an epoxy resin as component (A), a spike-shaped conductive filler as component (B), and a curing agent for the epoxy resin as component (C).

2. The conductive resin composition according to claim 1, comprising the following agent A and agent B, Agent A: a composition containing an epoxy resin as component (A) and a spike-shaped conductive filler as component (B); and Agent B: A composition containing a curing agent for epoxy resin as the component (C).

3. The conductive resin composition according to claim 1 or 2, wherein The component (B) is a spike-shaped nickel filler.

4. The conductive resin composition according to claim 1 or 2, wherein The component (A) contains at least a glycidylamine resin. 5 . The conductive resin composition according to claim 1 , further comprising a polyfunctional radical polymerizable compound as component (D).

6. The conductive resin composition according to claim 1 or 2, wherein The component (C) is in a liquid state at 25°C.

7. The conductive resin composition according to claim 1 or 2, which does not contain a peroxide.

8. The conductive resin composition according to claim 1 or 2, wherein The (B) component is contained in an amount of 100 to 1000 parts by mass based on 100 parts by mass of the (A) component. 9 . A cured product obtained by curing the conductive resin composition according to claim 1 or 2.

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