Insulative resin composition, cured product of same, and electronic component

Abstract

The present invention addresses the problem of providing an insulative resin composition suitable for aerosol-jet printing technologies.　Provided is an insulative resin composition which contains (A) inorganic particles having a mean particle diameter (D50) of 0.02-0.5 μm, (B) a polyfunctional thermosetting compound, and (C) a curing agent, and which has a viscosity of 400 mPa·s or less as measured using a type-E viscometer at a condition of 25°C and 50 rpm.

Description

Insulating resin composition, cured product thereof, and electronic component

[0001] The present invention relates to an insulating resin composition, a cured product thereof, and an electronic component including the cured product.

[0002] Printed electronics, in which conductive or insulating resin compositions are printed directly onto a target object based on digital data to form circuits, batteries, various sensors, or insulating patterns, is a field that has been attracting attention in recent years. Inkjet printing is one of the printing technologies that has long been used as a representative printing technology for printed electronics. Piezoelectric inkjet printing is a technology that applies pressure to ink inside a tiny nozzle with a diameter of approximately 20 to 50 μm to eject droplets.

[0003] The droplets ejected from the inkjet head are 10 to 100 μm in diameter, so the minimum achievable line width is 30 μm or more, which limits the line width. Also, because the printing gap between the nozzle surface and the printing target is narrow, this method is suitable for printing on two-dimensional flat surfaces, but presents challenges when used to print on three-dimensional curved surfaces.

[0004] In recent years, aerosol jet printing has attracted attention as a technology that overcomes the challenges posed by inkjet printing. Aerosol jet printing is a technology in which a generated aerosol is sprayed from a fine nozzle using gas (see, for example, Patent Document 1). Aerosol jet printing creates microdroplets with a diameter of 10 μm or less, transports them to a spraying unit (nozzle) using gas, and digitally controls the on-off of the spray from the nozzle toward a substrate, thereby enabling the formation of fine patterns, for example, with a minimum line width of 10 μm. Furthermore, this aerosol jet printing technology allows for a wide substrate-to-nozzle distance during printing, enabling printing even with a printing gap of approximately 5 mm, making it possible to print on substrates with irregularities of several mm or on three-dimensional curved surfaces.

[0005] Patent Document 2 discloses an insulating resin composition for inkjet that can be applied by an inkjet method, can maintain its shape after application, and can reduce the occurrence of voids after curing. The insulating resin composition for inkjet contains a monoacrylate having a viscosity of less than 3 mPa·s at room temperature and a filler having a maximum particle size of less than 3 μm.

[0006] JP 2011-502741 A JP 2018-117002 A

[0007] In aerosol jet printing technology, it is necessary to aerosolize the substance to be ejected, and therefore it is required to be able to form fine droplets with a diameter of 10 μm or less. However, when an attempt was made to apply a conventional curable resin composition such as the insulating resin composition for inkjet described in Patent Document 2 to aerosol jet printing technology, it was found that fine droplets could not be formed or the ejection properties were poor, making it unsuitable for aerosol jet printing technology.

[0008] An object of the present invention is to provide an insulating resin composition suitable for aerosol jet printing technology.

[0009] Specific means for solving the above problems are as follows. A first embodiment of the present invention is the following insulating resin composition. (1) An insulating resin composition comprising: (A) inorganic particles having an average particle size (D50) of 0.02 to 0.5 μm; (B) a polyfunctional thermosetting compound; and (C) a curing agent; wherein the insulating resin composition has a viscosity of 400 mPa·s or less as measured at 25°C and 50 rpm using an E-type viscometer. (2) The insulating resin composition according to (1) above, wherein the (A) inorganic particles are surface-treated with a (meth)acrylic surface treatment agent. (3) The insulating resin composition according to (1) or (2) above, wherein the (B) polyfunctional thermosetting compound comprises a bifunctional thermosetting compound. (4) The insulating resin composition according to any one of (1) to (3) above, further comprising (D) a monofunctional reactive diluent. (5) The insulating resin composition according to (4) above, wherein the content of the (D) monofunctional reactive diluent is 40 to 80 parts by mass per 100 parts by mass of the total amount of the (B) polyfunctional thermosetting compound, the (C) curing agent, and the (D) monofunctional reactive diluent. (6) The insulating resin composition according to any one of (1) to (5) above, wherein the content of the (A) inorganic particles is 15 to 50 parts by mass per 100 parts by mass of the resin composition. (7) The insulating resin composition according to any one of (1) to (6) above, wherein the insulating resin composition is substantially free of particles having a particle diameter of more than 1.0 μm. (8) The insulating resin composition according to any one of (1) to (7) above, which is for aerosol jet printing. (9) The insulating resin composition according to any one of (1) to (7) above, which is for inkjet printing.

[0010] A second embodiment of the present invention is (10) a cured product obtained by curing the insulating resin composition according to any one of (1) to (9) above. A third embodiment of the present invention is (11) an electronic component comprising the cured product according to (10) above. Embodiments of the present invention also include the following printing methods and uses. (12) An aerosol jet printing method comprising a step of aerosol jet printing the insulating resin composition according to any one of (1) to (9) above onto a substrate. (13) An inkjet printing method comprising a step of inkjet printing the insulating resin composition according to any one of (1) to (9) above onto a substrate. (14) Use of the insulating resin composition according to any one of (1) to (9) above in aerosol jet printing. (15) Use of the insulating resin composition according to any one of (1) to (9) above in inkjet printing.

[0011] According to a first embodiment of the present invention, an insulating resin composition suitable for aerosol jet printing techniques can be obtained. The insulating resin composition of the first embodiment is also suitable for inkjet printing techniques. Furthermore, according to a second embodiment of the present invention, a cured product of the insulating resin composition applied by aerosol jet printing or inkjet printing can be obtained. Furthermore, according to a third embodiment of the present invention, an electronic component including such a cured product can be obtained.

[0012] In this specification, following the convention in the field of synthetic resins, a name including the term "resin," which normally refers to a polymer (particularly a synthetic polymer), may be used for a component constituting a curable resin composition before curing, even if the component is not a polymer, for example, a prepolymer compound before curing.

[0013] [Insulating Resin Composition] The insulating resin composition according to a first embodiment of the present invention comprises: (A) inorganic particles having an average particle size (D50) of 0.02 to 0.5 μm; (B) a polyfunctional thermosetting compound; and (C) a curing agent; and has a viscosity of 400 mPa s or less as measured at 25°C and 50 rpm using an E-type viscometer. According to this embodiment, an insulating resin composition suitable for aerosol jet printing technology can be obtained.

[0014] (A) Inorganic particles having an average particle diameter (D50) of 0.02 to 0.5 μm The insulating composition of this embodiment contains (A) inorganic particles having an average particle diameter (D50) of 0.02 to 0.5 μm (hereinafter also referred to as "(A) inorganic particles" or "component (A)"). Component (A) acts as a filler, and can maintain an appropriate elastic modulus of the cured product obtained by curing the resin composition, while also reducing the linear expansion coefficient of the cured product. Examples of inorganic particles include, but are not limited to, insulating inorganic particles such as silica, alumina, and magnesium oxide. In this embodiment, the inorganic particles are preferably silica particles.

[0015] In this specification, the average particle size (D50) refers to the particle size (D50) of 50% of the cumulative total of all inorganic particles, and can be determined from the results of particle size distribution measurement performed by a microtrack method (laser diffraction scattering method).

[0016] In this embodiment, it is more preferable that the (A) inorganic particles are surface-treated with a (meth)acrylic surface treatment agent. Aerosol jet printing technology generates microdroplets (aerosol) with a diameter of 1 to 5 μm and delivers them to a nozzle via gas, so the particle diameter of the inorganic particles is required to be smaller than that of the microdroplets. However, reducing the particle diameter of the inorganic particles increases the viscosity of the resin composition, resulting in problems such as inability to aerosolize or eject from the nozzle. By including inorganic particles surface-treated with a (meth)acrylic surface treatment agent, the viscosity of the resin composition measured at 25°C and 50 rpm using an E-type viscometer can be reduced to 400 mPa·s or less, even if the particle diameter of the inorganic particles is small.

[0017] The surface treatment agent has two or more different functional groups in its molecule, one of which is a functional group that chemically bonds with the inorganic material, and the other is a functional group that chemically bonds with the organic material. Examples of the surface treatment agent include, but are not limited to, silane-based surface treatment agents, aluminum-based surface treatment agents, and titanium-based surface treatment agents, depending on the type of functional group that chemically bonds with the inorganic material. When the inorganic particles are silica, it is preferable to use a silane-based surface treatment agent.

[0018] The (meth)acrylic surface treatment agent has an acryloyl group or a methacryloyl group as a functional group that chemically bonds with the organic material. Specific examples of methacryl-silane surface treatment agents include, but are not limited to, 3-methacryloxypropyltrimethoxysilane (e.g., a commercially available product such as KBM503 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-methacryloxypropylmethyldimethoxysilane (e.g., a commercially available product such as KBM502 manufactured by Shin-Etsu Chemical Co., Ltd.), 3-methacryloxypropylmethyldiethoxysilane (e.g., a commercially available product such as KBE502 manufactured by Shin-Etsu Chemical Co., Ltd.), and 3-methacryloxypropyltriethoxysilane (e.g., a commercially available product such as KBE503 manufactured by Shin-Etsu Chemical Co., Ltd.). Specific examples of acrylic-silane surface treatment agents include, but are not limited to, 3-acryloxypropyltrimethoxysilane (e.g., a commercially available product such as KBM-5103 manufactured by Shin-Etsu Chemical Co., Ltd.).

[0019] The (meth)acrylic surface treatment agents may be used alone or in combination of two or more.

[0020] The average particle size (D50) of the (A) inorganic particles is, from the viewpoint of wettability and dispersibility in resin, 0.02 to 0.5 μm, preferably 0.03 to 0.4 μm, and more preferably 0.04 to 0.3 μm.

[0021] In the present embodiment, the content of the (A) inorganic particles is preferably 10 to 60 parts by mass, and more preferably 15 to 50 parts by mass, relative to 100 parts by mass of the resin composition, from the viewpoint of adjusting the viscosity of the resin composition and suppressing cure shrinkage of the cured product.

[0022] The insulating resin composition of this embodiment preferably does not substantially contain particles having a particle diameter of more than 1.0 μm. Particles having a particle diameter of more than 1.0 μm refer to inorganic particles such as silica, or organic particles made of resin such as fluororesin or acrylic resin, and have a particle diameter of more than 1.0 μm. This can prevent nozzle clogging when the resin composition is applied by aerosol jet printing.

[0023] (B) Polyfunctional Thermosetting Compound The insulating resin composition of this embodiment contains (B) a polyfunctional thermosetting compound (hereinafter also referred to as "component (B)"). The (B) polyfunctional thermosetting compound includes a heat- and light-curable compound. The (B) polyfunctional thermosetting compound has two or more functional groups, and thus can cure the resin composition by forming a crosslinked network between component (B) and a (C) curing agent described below through heat treatment, or by subjecting component (B) to a radical polymerization reaction through heat treatment and / or UV treatment, thereby imparting adhesive strength. Examples of polyfunctional thermosetting compounds include, but are not limited to, polyfunctional (meth)acrylate compounds having two or more (meth)acryloyloxy groups, polyfunctional epoxy compounds having two or more epoxy groups, polyfunctional maleimide compounds having two or more maleimide groups, and polyfunctional allyl ester compounds having two or more allyl ester groups. In one embodiment, (B) the multifunctional thermosetting compound is preferably a multifunctional (meth)acrylate compound, a multifunctional epoxy compound, or a combination thereof.

[0024] The polyfunctional (meth)acrylate compound can be cured by heat treatment and / or UV treatment. Examples of polyfunctional (meth)acrylate compounds include, but are not limited to, trimethylolpropane tri(meth)acrylate, 3-methyl-1,5 pentanediol di(meth)acrylate, glycidyl (meth)acrylate, ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,10-decanediol di(meth)acrylate, tetramethylene glycol di(meth)acrylate, glycerin di(meth)acrylate, trimethylolpropane di(meth)acrylate, pentaerythritol di(meth)acrylate, and pentaerythritol tri(meth)acrylate.

[0025] The polyfunctional epoxy compound can be cured by heat treatment. Examples of polyfunctional epoxy compounds include, but are not limited to, bisphenol A epoxy compounds, bisphenol F epoxy compounds, phenol novolac epoxy compounds, alicyclic epoxy compounds, polyfunctional tetrakis(hydroxyphenyl)ethane or tris(hydroxyphenyl)methane epoxy compounds having many benzene rings, biphenyl epoxy compounds, triphenolmethane epoxy compounds, polybutadiene epoxy compounds (epoxidized polybutadiene), naphthalene epoxy compounds, dicyclopentadiene epoxy compounds, aminophenol epoxy compounds, and silicone epoxy compounds. Polyglycidyl esters such as diglycidyl ether of bisphenol A ethylene oxide adduct and diglycidyl ether of bisphenol A propylene oxide adduct, and reaction products of p-xylylene glycol and 1-chloro-2,3-epoxypropane can also be used as polyfunctional epoxy compounds.

[0026] The polyfunctional maleimide compound can be cured by heat treatment and / or UV treatment. Examples of polyfunctional maleimide compounds include, but are not limited to, bismaleimide compounds such as N,N'-(4,4'-diphenylmethane)bismaleimide, bis(3-ethyl-5-methyl-4-maleimidophenyl)methane, and 2,2-bis[4-(4-maleimidophenoxy)phenyl]propane. Other examples of polyfunctional maleimide compounds include compounds obtained by reacting dimer acid diamine with maleic anhydride, and compounds obtained by reacting maleimidated amino acids, such as maleimidoacetic acid and maleimidocaproic acid, with polyols. Maleimidated amino acids are obtained by reacting maleic anhydride with aminoacetic acid or aminocaproic acid, and preferred polyols are polyether polyols, polyester polyols, polycarbonate polyols, and poly(meth)acrylate polyols, with those not containing an aromatic ring being particularly preferred. Since the maleimide group can react with an allyl group, it is also preferable to use it in combination with a polyfunctional allyl ester compound. The polyfunctional allyl ester compound is preferably an aliphatic compound, and among them, a compound obtained by transesterification of a cyclohexane diallyl ester with an aliphatic polyol is more preferable.

[0027] In this embodiment, from the viewpoint of viscosity of the resin composition, it is preferable that the (B) polyfunctional thermosetting compound contains a bifunctional thermosetting compound. In one aspect, it is preferable that the (B) polyfunctional thermosetting compound contains a trifunctional or higher functional thermosetting compound from the viewpoint of increasing the elastic modulus of the cured product. In another aspect, it is preferable that the (B) polyfunctional thermosetting compound contains a combination of a bifunctional thermosetting compound and a trifunctional or higher functional thermosetting compound.

[0028] The polyfunctional thermosetting compound (B) is preferably liquid at 25°C.

[0029] In the present embodiment, from the viewpoint of appropriately increasing the elastic modulus of the cured product, the content of the (B) polyfunctional thermosetting compound is preferably 20 to 80 parts by mass, more preferably 20 to 75 parts by mass, and preferably 30 to 70 parts by mass, relative to 100 parts by mass of the resin composition.

[0030] (C) Curing Agent The insulating resin composition of this embodiment contains a (C) curing agent (hereinafter also referred to as "component (C)"). This allows the resin composition to be cured by forming a crosslinked network between component (B) and component (C) through heat treatment, or by a radical polymerization reaction of component (B) initiated by component (C) through heat treatment and / or UV treatment. In this embodiment, the (C) curing agent includes a (C1) curing agent for a crosslinking reaction and a (C2) curing agent for a radical polymerization reaction. Examples of the (C1) curing agent for the crosslinking reaction include, but are not limited to, phenol-based curing agents, acid anhydride-based curing agents, amine-based curing agents, modified imidazole-based curing agents, hydrazide compounds, dicyandiamide, and thiol-based curing agents. From the viewpoint of the adhesiveness of the resin composition, phenol-based curing agents are more preferred. Note that in this embodiment, the (C1) curing agent for the crosslinking reaction also includes so-called curing accelerators that act catalytically to promote crosslinking. (C2) The curing agent for the radical polymerization reaction includes a photoradical polymerization initiator and a thermal radical polymerization initiator. The curing agent (C) can be appropriately selected depending on the type of component (B).

[0031] (C1) Curing Agent for Crosslinking Reaction When component (B) contains a polyfunctional thermosetting compound such as a polyfunctional epoxy compound, the resin composition of the present embodiment preferably contains (C1) a curing agent for crosslinking reaction.

[0032] As the phenolic curing agent, a phenolic resin known as a curing agent for epoxy resins can be used. Specific examples of phenolic curing agents include, but are not limited to, resole or novolac phenolic resins, alkyl resole phenolic resins, alkyl novolac phenolic resins, aralkyl novolac phenolic resins, xylene resins, and allyl phenolic resins. The OH group equivalent of the phenolic curing agent is preferably 80 to 250 g / eq, and more preferably 80 to 200 g / eq. In the case of alkyl resole or alkyl novolac phenolic resins, alkyl groups having 1 to 18 carbon atoms can be used, with alkyl groups having 2 to 10 carbon atoms, such as ethyl, propyl, butyl, pentyl, hexyl, octyl, nonyl, and decyl, being preferred. Commercially available phenolic curing agents include, but are not limited to, the phenolic resin curing agent manufactured by Meiwa Kasei Co., Ltd. (product name: MEH8005).

[0033] As the acid anhydride curing agent, acid anhydrides known as epoxy resin curing agents can be used. Specific examples of acid anhydride curing agents include, but are not limited to, phthalic anhydride, maleic anhydride, dodecenyl succinic anhydride, trimellitic anhydride, benzophenone tetracarboxylic dianhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, etc. Commercially available acid anhydride curing agents include, but are not limited to, acid anhydride curing agent (product name: YH307) manufactured by Mitsubishi Chemical Corporation.

[0034] Amine-based curing agents include imidazoles as well as aliphatic amines and aromatic amines. Among these, imidazoles are also used as curing accelerators that accelerate the reaction between the epoxy compound and the curing agent. Examples of aliphatic amines include aliphatic polyamines such as diethylenetriamine, triethylenetetraamine, tetraethylenepentamine, trimethylhexamethylenediamine, m-xylenediamine, and 2-methylpentamethylenediamine; alicyclic polyamines such as isophoronediamine, 1,3-bisaminomethylcyclohexane, bis(4-aminocyclohexyl)methane, norbornenediamine, and 1,2-diaminocyclohexane; and piperazine-type polyamines such as N-aminoethylpiperazine and 1,4-bis(2-amino-2-methylpropyl)piperazine, but are not limited to these. Examples of aromatic amines include, but are not limited to, aromatic polyamines such as diaminodiphenylmethane, m-phenylenediamine, diaminodiphenylsulfone, diethyltoluenediamine, trimethylenebis(4-aminobenzoate), polytetramethyleneoxide-di-p-aminobenzoate, tris(dimethylaminomethyl)phenol, benzyldimethylamine, and 1,8-diazabicyclo(5,4,0)undensene-7.

[0035] Examples of imidazoles include imidazole compounds such as 2-ethyl-4-methylimidazole, 2-phenylimidazole, 2-methylimidazole, 2-phenyl-4-methylimidazole, 1-cyanoethyl-2-methylimidazole, 1-cyanoethyl-2-undecylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and 2-phenyl-4,5-dihydroxymethylimidazole, but are not limited to these.

[0036] Examples of modified imidazole curing agents include epoxy-imidazole adduct compounds and acrylate-imidazole adduct compounds. Commercially available epoxy-imidazole adduct compounds include curing agents manufactured by Ajinomoto Fine-Techno Co., Ltd. (product names: Amicure PN-23, Amicure PN-40), curing agents manufactured by Asahi Kasei E-materials Corporation (product name: Novacure HX-3721), and curing agents manufactured by T&K TOKA Corporation (product name: Fujicure FX-1000), but are not limited thereto. Commercially available acrylate-imidazole adduct compounds include curing agents manufactured by ADEKA Corporation (product name: EH2021), but are not limited thereto.

[0037] Examples of thiol-based curing agents include, but are not limited to, 2-ethylhexyl-3-mercaptopropionate, n-octyl-3-mercaptopropionate, tetraethylene glycol bis(3-mercaptopropionate), trimethylolpropane tris(3-mercaptopropionate), tris-[(3-mercaptopropionyloxy)-ethyl]-isocyanurate, polysulfide polymers, 1,4-bis(3-mercaptobutyryloxy)butane, 1,3,5-tris(3-mercaptobutyryloxyethyl)-1,3,5-triazine-2,4,6(1H,3H,5H)-trione, trimethylolpropane tris(3-mercaptobutyrate), trimethylolethane tris(3-mercaptobutyrate), and the like. The thiol-based curing agent can also react with a polyfunctional (meth)acrylate compound or a polyfunctional maleimide compound.

[0038] The curing agent (C1) may be used alone or in combination of two or more.

[0039] From the viewpoint of storage stability and curability, the amount of the curing agent (C1) is preferably 0.1 to 10 parts by mass per 100 parts by mass of the resin composition (excluding the solvent).

[0040] (C2) Curing Agent for Radical Polymerization Reaction When component (B) contains a polyfunctional thermosetting compound such as a polyfunctional (meth)acrylate compound or a polyfunctional maleimide compound, the resin composition of the present embodiment preferably contains (C2) a curing agent for radical polymerization reaction.

[0041] When component (B) includes a polyfunctional (meth)acrylate compound or a polyfunctional maleimide compound, the resin composition of this embodiment may also include a photoradical polymerization initiator. By including a photoradical polymerization initiator, UV curing is promoted. This allows, for example, the resin composition to be temporarily fixed by UV curing. Examples of photoradical polymerization initiators include alkylphenone compounds and acylphosphine oxide compounds.

[0042] Examples of alkylphenone compounds include benzyl dimethyl ketals such as 2,2-dimethoxy-1,2-diphenylethan-1-one (for example, commercially available as Omnirad 651 from IGM Resins B.V.); α-aminoalkylphenones such as 2-methyl-2-morpholino(4-thiomethylphenyl)propan-1-one (for example, commercially available as Omnirad 907 from IGM Resins B.V.); α-hydroxyalkylphenones such as 1-hydroxy-cyclohexyl-phenyl-ketone (for example, commercially available as Omnirad 184 from IGM Resins B.V.); 2-dimethylamino-2-(4-methyl-benzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one (for example, commercially available as IGM Resins B.V.) Examples of suitable methyl methyl acrylates include, but are not limited to, 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone (for example, a commercially available product, Omnirad 369, manufactured by IGM Resins BV), and 2-benzyl-2-(dimethylamino)-4'-morpholinobutyrophenone (for example, a commercially available product, Omnirad 369, manufactured by IGM Resins BV).

[0043] Examples of the acylphosphine oxide compound include, but are not limited to, 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (for example, a commercially available product such as Omnirad TPO H manufactured by IGM Resins B.V.), bis(2,4,6-trimethylbenzoyl)-phenylphosphine oxide (for example, a commercially available product such as Omnirad 819 manufactured by IGM Resins B.V.), and the like.

[0044] As the photoradical polymerization initiator, any one of them may be used alone, or two or more of them may be used in combination.

[0045] When the resin composition contains a photoradical polymerization initiator, the content of the photoradical polymerization initiator is preferably 0.01 to 5 mass%, more preferably 0.1 to 3 mass%, relative to the total mass of the resin composition, from the viewpoints of the curing rate and pot life of the resin composition.

[0046] When component (B) includes a polyfunctional (meth)acrylate compound or a polyfunctional maleimide compound, the resin composition of this embodiment may also include a thermal radical polymerization initiator. By including a thermal radical polymerization initiator in the resin composition, it becomes possible to cure the resin composition by heating for a short period of time. There are no particular limitations on the thermal radical polymerization initiator that can be used, and known materials can be used. Specific examples of thermal radical polymerization initiators include dialkyl peroxides such as dicumyl peroxide, t-butylcumyl peroxide, 1,3-bis(2-t-butylperoxyisopropyl)benzene, and 2,5-dimethyl-2,5-bis(t-butylperoxy)hexane; 1,1-bis(t-butylperoxy)cyclohexane, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 1,1-bis(t-amylperoxy)cyclohexane, and 2,2-bis(t-butylperoxy)hexane. peroxyketals such as t-butylperoxy)butane, n-butyl 4,4-bis(t-butylperoxy)valerate, or ethyl 3,3-(t-butylperoxy)butyrate; and alkyl peroxyesters such as t-butylperoxy 2-ethylhexanoate, 1,1,3,3-tetramethylbutylperoxy-2-ethylhexanoate, t-butylperoxyisobutyrate, t-butylperoxymaleate, or t-butylperoxybenzoate. As the thermal radical polymerization initiator, any one of them may be used alone, or two or more of them may be used in combination.

[0047] When the resin composition contains a thermal radical polymerization initiator, the content of the thermal radical polymerization initiator is preferably 0.01 to 5 mass %, more preferably 0.1 to 3 mass %, relative to the total mass of the resin composition.

[0048] The curing agent (C) may be used alone or in combination of two or more thereof.

[0049] (D) Monofunctional Reactive Diluent The resin composition of this embodiment preferably contains (D) a monofunctional reactive diluent (hereinafter also referred to as "component (D)"). By including the (D) monofunctional reactive diluent, the viscosity of the resin composition can be reduced. Furthermore, because it is monofunctional, it does not form crosslinks, and can suppress an increase in internal stress of the cured product due to excessive crosslink density. This can suppress cure shrinkage of the cured product and provide flexibility. Examples of (D) monofunctional reactive diluents include monofunctional (meth)acrylate compounds, monofunctional maleimide compounds, and monofunctional epoxy compounds. In this embodiment, the (D) monofunctional reactive diluent is preferably a monofunctional (meth)acrylate compound. In one aspect, the (D) monofunctional reactive diluent preferably contains a monofunctional reactive diluent having a rigid structure such as an isobornyl structure or a dicyclopentadienyl structure. By including a monofunctional reactive diluent having a rigid structure, the viscosity of the resin composition can be reduced, the glass transition temperature (Tg) of the cured product can be increased, and the shrinkage of the cured product can be reduced.

[0050] Examples of monofunctional (meth)acrylate compounds include ethyl (meth)acrylate, trifluoroethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, glycidyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, isoamyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, isobornyl (meth)acrylate, stearyl (meth)acrylate, lauryl (meth)acrylate, phenoxyethyl (meth)acrylate, benzyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, ethoxydiethylene glycol (meth)acrylate, phenoxydiethylene glycol (meth)acrylate, (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, butoxydiethylene glycol (meth)acrylate, methoxydipropylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, methoxytriethylene glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, 2-ethylhexyldiethylene glycol (meth)acrylate, 4-tert-butylcyclohexyl (meth)acrylate, 3-phenoxybenzyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, octyl acrylate, nonyl acrylate, isononyl acrylate, 3,3,5-Trimethylcyclohexyl acrylate, cyclic trimethylolpropane formal acrylate, 1-naphthalenemethyl (meth)acrylate, 1-ethylcyclohexyl (meth)acrylate, 1-methylcyclohexyl (meth)acrylate, 1-ethylcyclopentyl (meth)acrylate, 1-methylcyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentanyl (meth)acrylate, nonyl phenoxy polyethylene glycol (meth)acrylate, tetrahydrodicyclopentadienyl (meth)acrylate, 2-(o-phenylphenoxy)ethyl (meth)acrylate, isobornylcyclohexyl (meth)acrylate, (2-methyl-2-ethyl-1,3-dioxolan-4-yl)methyl (meth)acrylate, 1-adamantyl (meth)acrylate, 3-hydroxy-1-adamantyl (meth)acrylate, 2-methyl-2-adamantanyl (meth)acrylate, 2- Ethyl-2-adamantanyl (meth)acrylate, 2-isopropyladamantan-2-yl (meth)acrylate, 3-hydroxy-1-adamantyl (meth)acrylate, (adamantan-1-yloxy)methyl (meth)acrylate, 2-isopropyl-2-adamantyl (meth)acrylate, 1-methyl-1-ethyl-1-adamantylmethanol (meth)acrylate, 1,1-diethyl-1-adamantylmethanol (meth)acrylate, 2-cyclohexylpropane-2-yl (meth)acrylate, 1-isopropylcyclohexyl (meth)acrylate, 1-methylcyclohexyl (meth)acrylate, 1-ethylcyclopentyl (meth)acrylate, 1-methylcyclohexyl (meth)acrylate, tetrahydropyranyl (meth)acrylate, tetrahydro-2-furanyl (meth)acrylate, 2-oxotetrahydrofuran-3-yl (meth)acrylate, (5-oxotetrahydrofuran-2-yl)methyl (meth)acrylate, (2-oxo-1,Examples of suitable diluents include, but are not limited to, 3-dioxolan-4-yl)methyl (meth)acrylate and 1-ethoxyethyl (meth)acrylate. These may be used alone or in combination of two or more. Among these, monofunctional reactive diluents having an isobornyl structure such as isobornyl (meth)acrylate, and monofunctional reactive diluents having a dicyclopentadienyl structure such as dicyclopentenyl (meth)acrylate, dicyclopentanyl (meth)acrylate, and dicyclopentenyloxyethyl (meth)acrylate are preferred. These may be used alone or in combination of two or more.

[0051] Examples of monofunctional maleimide compounds include, but are not limited to, maleimides; aliphatic hydrocarbon group-containing maleimides such as methylmaleimide, ethylmaleimide, propylmaleimide, butylmaleimide, hexylmaleimide, octylmaleimide, dodecylmaleimide, stearylmaleimide, and cyclohexylmaleimide; and aromatic ring-containing maleimides such as phenylmaleimide. These may be used alone or in combination of two or more.

[0052] Examples of monofunctional epoxy compounds include aromatic monofunctional epoxy compounds such as phenyl glycidyl ether, cresyl glycidyl ether, p-s-butylphenyl glycidyl ether, styrene oxide, p-tert-butylphenyl glycidyl ether, o-phenylphenol glycidyl ether, p-phenylphenol glycidyl ether, and N-glycidylphthalimide; and aliphatic monofunctional epoxy compounds such as n-butyl glycidyl ether, 2-ethylhexyl glycidyl ether, α-pinene oxide, allyl glycidyl ether, 1-vinyl-3,4-epoxycyclohexane, 1,2-epoxy-4-(2-methyloxiranyl)-1-methylcyclohexane, 1,3-bis(3-glycidoxypropyl)-1,1,3,3-tetramethyldisiloxane, and neodecanoic acid glycidyl ester, but are not limited to these. These compounds may be used alone or in combination of two or more.

[0053] The monofunctional reactive diluent (D) may be used alone or in combination of two or more kinds.

[0054] When the resin composition of this embodiment contains a monofunctional reactive diluent (D), the content of the monofunctional reactive diluent (D) is preferably 40 to 80 parts by mass, and more preferably 45 to 70 parts by mass, per 100 parts by mass of the total amount of the polyfunctional thermosetting compound (B), the curing agent (C), and the monofunctional reactive diluent (D). By setting the proportion of the monofunctional reactive diluent (D) within the above range, the viscosity of the resin composition can be reduced, and the coatability by the aerosol jet method can be further improved.

[0055] (E) Other Additives If desired, the resin composition of the present embodiment may contain other additives, such as carbon black, titanium black, a silane coupling agent, an ion trapping agent, a leveling agent, an antioxidant, an antifoaming agent, a viscosity modifier, a flame retardant, or a solvent, as needed, within a range that does not impair the properties of the resin composition of the present embodiment. The type and amount of each additive are as usual.

[0056] The method for producing the resin composition of this embodiment is not particularly limited. The resin composition of this embodiment can be obtained, for example, by simultaneously or separately introducing components (A) to (C), and optionally components (D) and (E) and other additives, into an appropriate mixer, and stirring and mixing while melting by heating if necessary to form a homogeneous composition. The mixer is not particularly limited, but examples include a Raikai mixer, Henschel mixer, three-roll mill, ball mill, planetary mixer, and bead mill equipped with a stirrer and a heater. These devices may also be used in appropriate combination.

[0057] The resin composition thus obtained is thermosetting and can be cured by heat treatment at 130 to 200° C. for 30 to 180 minutes, for example.

[0058] Furthermore, when component (B) contains a polyfunctional (meth)acrylate compound or a polyfunctional maleimide compound, the resin composition is photocurable and thermosetting. In this case, after application of the resin composition, it can be temporarily fixed by applying light of a predetermined wavelength, and then fully cured by applying heat to form a cured product. The specific methods for temporary fixing and fully curing are not particularly limited. When photocuring the resin composition, the light to be irradiated is, for example, ultraviolet (UV) light. In one embodiment, the resin composition may be only photocured.

[0059] In this embodiment, the viscosity of the resin composition measured using an E-type viscometer at 25°C and 50 rpm is 400 mPa·s or less, preferably 350 mPa·s or less, and more preferably 300 mPa·s or less. The resin composition of this embodiment is suitable for aerosol jet printing due to its low viscosity despite containing inorganic particles with small particle diameters. From the viewpoint of suppressing cure shrinkage, the lower limit of the viscosity of the resin composition measured using an E-type viscometer at 25°C and 50 rpm is, for example, 50 mPa·s or more, preferably 100 mPa·s or more, and more preferably 200 mPa·s or more. In one aspect, the viscosity of the resin composition measured using an E-type viscometer at 25°C and 50 rpm is preferably 50 to 400 Pa·s, more preferably 100 to 350 Pa·s, and even more preferably 200 to 300 Pa·s.

[0060] The method for applying the resin composition of this embodiment is not particularly limited, and for example, it can be applied to a desired portion of a substrate or the like by a known printing method, dispensing method, or coating method. Examples of printing or dispensing methods include, but are not limited to, aerosol jet printing, inkjet printing (jet dispense printing), screen printing, lithographic printing, carton printing, metal printing, offset printing, gravure printing, flexographic printing, and air dispenser. Examples of coating methods include, but are not limited to, dip coating, spray coating, bar coater coating, gravure coating, reverse gravure coating, and spin coater coating. The method for applying the resin composition of this embodiment is preferably aerosol jet printing or inkjet printing, and more preferably aerosol jet printing. Use of the insulating resin composition of this embodiment in aerosol jet printing or inkjet printing also represents one embodiment of the present invention.

[0061] [Cured Product of Resin Composition] The cured product of the second embodiment of the present invention is a cured product obtained by curing the insulating resin composition of the first embodiment described above.

[0062] From the viewpoint of adhesiveness, the cured product of this embodiment preferably has a modulus of elasticity of 1.0 to 9.0 GPa, more preferably 3.5 to 8.0 GPa, and even more preferably 4.0 to 7.0 GPa. The modulus of elasticity of the cured product can be adjusted by adjusting the types and amounts of the components of the resin composition. For example, when each component contains a rigid structure such as biphenyl, naphthalene, dicyclopentadiene, cresol novolac, isobornyl, or dicyclopentadienyl, the modulus of elasticity tends to be high. Furthermore, for example, the modulus of elasticity tends to be high by increasing the crosslink density by including a polyfunctional thermosetting compound having three or more functionalities.

[0063] From the viewpoint of solder reflowability, the cured product of this embodiment preferably has a glass transition temperature (Tg) of 60°C or higher, more preferably 70°C or higher, and even more preferably 80°C or higher. The Tg of the cured product can be adjusted by adjusting the type and amount of components of the resin composition. For example, when each component contains a rigid structure such as biphenyl, naphthalene, dicyclopentadiene, cresol novolac, isobornyl, or dicyclopentadienyl, the Tg tends to be high. Furthermore, for example, the Tg tends to be high by increasing the crosslink density by including a trifunctional or higher polyfunctional thermosetting compound. The upper limit of the Tg of the cured product is not particularly limited, but is preferably 260°C or lower.

[0064] [Electronic Component] An electronic component according to a third embodiment of the present invention includes the cured product according to the second embodiment. Examples of the electronic component include a semiconductor package manufactured by adhering a semiconductor chip (die) such as an IC or LSI to a support member such as a substrate, bonding the die to the support member, and then sealing with a molding compound. Such a semiconductor package can be mounted on a printed circuit board or a motherboard.

[0065] [Printing Method, Method for Producing Cured Product] Another embodiment of the present invention is an aerosol jet printing method including a step of aerosol jet printing the insulating resin composition of the first embodiment onto a substrate. In aerosol jet printing technology, minute droplets with a diameter of 10 μm or less are created, transported to a spraying unit (nozzle) by gas, and the on-off control of the spray from the nozzle toward the substrate is digitally controlled, thereby enabling the formation of fine patterns, for example, with a minimum line width of 10 μm. Furthermore, this aerosol jet printing technology allows for a wide substrate-to-nozzle distance during printing, enabling printing even with a print gap of about 5 mm, thereby enabling printing on substrates with irregularities of about several mm or three-dimensional curved surfaces. The substrate may be, for example, a component constituting an electronic component, such as a semiconductor element or a substrate, but is not limited thereto. The component material may be any of engineering plastics (e.g., LCP (liquid crystal polymer), polyamide, polycarbonate, etc.), ceramics, or metals (e.g., copper, nickel), etc. Yet another embodiment of the present invention is a method for producing a cured product, comprising: a step of aerosol jet printing the insulating resin composition of the above-mentioned first embodiment onto a substrate; and a step of curing the aerosol jet-printed insulating resin composition.

[0066] Another embodiment of the present invention is an inkjet printing method comprising the step of inkjet printing the insulating resin composition of the first embodiment described above onto a substrate. The substrate is, for example, a component constituting an electronic part, such as, but not limited to, a semiconductor element, a substrate, etc. The material of the component may be any of engineering plastics (e.g., LCP (liquid crystal polymer), polyamide, polycarbonate, etc.), ceramics, metals (e.g., copper, nickel), etc. Yet another embodiment of the present invention is a method for producing a cured product comprising: a step of inkjet printing the insulating resin composition of the first embodiment described above onto a substrate; and a step of curing the inkjet-printed insulating resin composition.

[0067] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to these examples. In the following examples, parts and % represent parts by mass and % by mass unless otherwise specified.

[0068] [Examples 1 to 12, Comparative Examples 1 to 4] [Preparation of Resin Compositions] Resin compositions were prepared by mixing predetermined amounts of each component using a three-roll mill according to the formulations shown in Table 1. In Table 1, the amount of each component is expressed in parts by mass (unit: g). The components used in the examples and comparative examples are as follows.

[0069] (A) Inorganic particles having an average particle size (D50) of 0.02 to 0.5 μm (A-1): (meth)acrylic surface-treated silica filler 1 (product name: YC100-SM1, manufactured by Admatechs Co., Ltd., average particle size (D50): 0.1 μm, surface treatment agent: 3-methacryloxypropyltrimethoxysilane) (A-2): (meth)acrylic surface-treated silica filler 2 (product name: YA050C-SM1, manufactured by Admatechs Co., Ltd., average particle size (D50): 0.05 μm, surface treatment agent: 3-methacryloxypropyltrimethoxysilane) (A'): Inorganic particles other than component (A) (A'-1): (meth)acrylic surface-treated silica filler 3 (product name: SE2200-SME, manufactured by Admatechs Co., Ltd., average particle size (D50): more than 1 μm, surface treatment agent: 3-glycidoxypropyltrimethoxysilane) (A'-2): (meth)acrylic surface-treated silica filler 4 (product name: YA010C-SM1, manufactured by Admatechs Co., Ltd., average particle size (D50): 0.01 μm, surface treatment agent: 3-methacryloxypropyltrimethoxysilane) (A'-3): silica filler without surface treatment (product name: Seahoster KE-S30HG, manufactured by Nippon Shokubai Co., Ltd., average particle size (D50): 0.3 μm) (A'-4): trimethyl surface-treated silica filler (AEROSIL (registered trademark) RX50, manufactured by Nippon Aerosil Co., Ltd., average particle size (D50): 0.02 to 0.10 μm)

[0070] (B) Multifunctional thermosetting compound (B-1): Trifunctional (meth)acrylate compound (chemical name: trimethylolpropane triacrylate, product name: Light Acrylate TMP-A, manufactured by Kyoeisha Chemical Co., Ltd., viscosity: 80 to 120 mPa·s, Cas. No.: 15625-89-5) (B-2): Bifunctional (meth)acrylate compound 1 (chemical name: 3-methyl-1.5 pentanediol diacrylate, product name: Light Acrylate MPD-A, manufactured by Kyoeisha Chemical Co., Ltd., viscosity: 8 mPa·s, Cas. No.: 64194-22-5) (B-3): Bifunctional (meth)acrylate compound 2 (chemical name: 1,9-nonanediol diacrylate, product name: Light Acrylate 1.9ND-A, manufactured by Kyoeisha Chemical Co., Ltd., viscosity: 10 mPa·s, Cas. No.: 107481-28-7) (B-4): Trifunctional epoxy compound (chemical name: N,N-diglycidyl-4-(glycidyloxy)aniline, product name: jER-630, manufactured by Mitsubishi Chemical Corporation, viscosity: 5000 to 10000 mPa·s, Cas. No.: 5026-74-4) (B-5): Bifunctional epoxy compound 1 (polyoxyalkylene bisphenol A diglycidyl ether, product name: EP4000S, manufactured by ADEKA Corporation, viscosity: 1800 mPa·s, Cas. No.: 36484-54-5) (B-6): Difunctional epoxy compound 2 (tetramethylbiphenyl epoxy compound, product name: YX4000H, manufactured by Mitsubishi Chemical Corporation, solid (room temperature), Cas. No.: 85954-11-6) (B-7): Difunctional epoxy compound 3 (polypropylene glycol type epoxy compound, product name: PG207GS, manufactured by Nippon Steel Chemical & Material Co., Ltd., viscosity: 20 to 70 mPa s, Cas. No.: 9072-62-2)

[0071] (C) Curing Agents (C-1): Phenol-based curing agent (product name: MEH8005, manufactured by Meiwa Chemical Industry Co., Ltd., viscosity: 4500 to 7500 mPa·s, Cas. No.: 27924-97-6 or 9003-35-4) (C-2): Imidazole-based curing agent (chemical name: 4-methyl-2-phenylimidazole, product name: 2P 4MZ, manufactured by Shikoku Chemical Industry Co., Ltd., Cas. No.: 827-43-0) (C-3): 1-hydroxy-cyclohexyl-phenyl-ketone (photoradical polymerization initiator, product name: Omnirad 184, manufactured by IGM Resins B.V., solid (room temperature), Cas. No.: 947-19-3) (C-4): 2,4,6-trimethylbenzoyl-diphenyl-phosphine oxide (photoradical polymerization initiator, product name: Omnirad TPO H, manufactured by IGM Resins B.V., solid (room temperature), Cas. No.: 75980-60-8) (C-5): 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanoate (thermal radical polymerization initiator, product name: Perocta O, manufactured by NOF Corporation, liquid (room temperature), Cas. No.: 22288-43-3)

[0072] (D) Monofunctional reactive diluent (D-1): Isobornyl acrylate (product name: IBXA, manufactured by Kyoeisha Chemical Co., Ltd., viscosity: 5 to 10 mPa·s, Cas. No.: 5888-33-5) (D-2): Dicyclopentanyl acrylate (product name: FA513AS, manufactured by Showa Denko Materials Co., Ltd., viscosity: 7 to 17 mPa·s, Cas. No.: 79637-74-4)

[0073] In the examples and comparative examples, the properties of the resin compositions and the cured products obtained by curing the resin compositions were measured as follows.

[0074] [Viscosity Measurement] The viscosity of each resin composition was measured at 25°C at 5 rpm and 50 rpm using a cone-plate type viscometer TV-22 (cone plate: 1°34' x R24) manufactured by Toki Sangyo Co., Ltd. The viscosity at 50 rpm is shown in Table 1 as "viscosity." In the table, "N.A." indicates that the viscosity was outside the measurement range and could not be measured. The results are shown in Table 1.

[0075] [Aerosol Jet Printing Evaluation Test] Each resin composition was evaluated using an aerosol jet dispenser (OPTOMEC Corporation: Aerosol Jet: AJHD2). The evaluation conditions were as follows: nozzle 300 (μm), sheath gas 80 sccm, atomization gas 900 sccm, distance between nozzle and substrate 5 mm, printing speed 10 mm / sec. Each resin composition was sprayed onto a glass substrate. Those that could be ejected without nozzle clogging were marked with "◯", and those that could not be ejected were marked with "X". The results are shown in Table 1.

[0076] [Inkjet Printing Evaluation Test] Each resin composition was evaluated using a jet dispenser (AeroJet: MJET-A-2 manufactured by Musashi Engineering Co., Ltd.). The evaluation conditions were as follows: Sheet: W type, Rod: M lot, Nozzle: 26G, Stroke: 100 (μm), Pressure: 125 (MPa), On time: 3.5 (msec), Off time: 5 (msec). Each resin composition was sprayed onto a glass substrate. Those that could be ejected without nozzle clogging were marked with "O", and those that could not be ejected were marked with "X". The results are shown in Table 1.

[0077] [Measurement of Elastic Modulus and Glass Transition Temperature (Tg) of Cured Product] Two glass plates coated with a release agent and dried were prepared. A resin composition was coated on one glass plate, and after a gap was set so that the film thickness was approximately 100 μm, the glass plate was sandwiched between the other glass plate. One side was irradiated with 500 mJ / cm using an LED-type UV irradiation device (Omnicure: AC475, manufactured by Excelitas). ２ The film was then turned over and irradiated with 500 mJ / cm of UV light (wavelength 365 nm). ２The sample was then irradiated with UV light (wavelength 365 nm). The sample was then cured into a sheet at 175°C for 60 minutes. This was then processed into a 40 mm x 5 mm test piece for dynamic viscoelasticity measurement (DMA). DMA measurements were performed using a viscoelasticity measuring device (Seiko Instruments Inc. DMS6100) under the following conditions: measurement mode: tension, heating rate: 3°C / min, measurement frequency: 10 Hz, and the modulus of elasticity and Tg at room temperature were determined. In the table, "N.A." indicates values ​​outside the measurement range and therefore unmeasurable. The results are shown in Table 1. From the viewpoint of adhesiveness, the modulus of elasticity of the cured product is preferably in the range of 1.0 to 9.0 GPa, more preferably 3.5 to 8.0 GPa, and even more preferably 4.0 to 7.0 GPa. From the viewpoint of solder reflowability, the Tg of the cured product is preferably in the range of 60°C or higher, more preferably 70°C or higher, and even more preferably 80°C or higher. The upper limit is not particularly limited, but is preferably 260°C or less.

[0078] [Measurement of shrinkage rate of cured product] The specific gravity of the resin composition at 25°C (liquid specific gravity) was measured using a 10 cc pycnometer made of polytetrafluoroethylene (PTFE). Two glass plates coated with a release agent and dried were prepared. The resin composition was coated on one glass plate, and after a gap was set so that the film thickness was approximately 300 μm, the glass plate was sandwiched between the other glass plate. One side was irradiated with 500 mJ / cm using an LED-type UV irradiation device (Omnicure: AC475, manufactured by Excelitas). ２ The film was then turned over and irradiated with 500 mJ / cm of UV light (wavelength 365 nm). ２ The film was irradiated with UV light (wavelength 365 nm). It was then cured at 175°C for 60 minutes under heating conditions. The weight (a, unit: g) of the cured film was measured, and the cured film was then placed in pure water and thoroughly degassed. The weight (b, unit: g) of the degassed cured film was measured, and the specific gravity was calculated using equation (1) (specific gravity of the cured product). The shrinkage of the cured product was calculated using equation (3). The results are shown in Table 1. Specific gravity of the cured product (g / cm ３ ) = weight of cured film (a) / volume (cm ３ ) ... (1) Volume (cm ３ ) = ((a) - (b)) / density of water at temperature c (g / cm ３) (2) Shrinkage rate (%) = {1 - (specific gravity of liquid / specific gravity of cured product)} × 100 (3) From the viewpoint of suppressing peeling and cracking, the shrinkage rate of the cured product is preferably in the range of 8.0% or less, more preferably 7.0% or less, even more preferably 6.0% or less, and particularly preferably 5.0% or less.

[0079]

[0080] All of the resin compositions of Examples 1 to 12 exhibited good dischargeability in both aerosol jet printing and inkjet printing. Comparative Example 1, which used inorganic particles with an average particle diameter (D50) larger than that of the (A) inorganic particles of the present invention, had a low viscosity, but the inorganic particles had a large particle diameter, making it impossible to aerosolize the resin composition and ejecting it by aerosol jet printing. Comparative Example 2, which used inorganic particles with an average particle diameter (D50) smaller than that of the (A) inorganic particles of the present invention, made it impossible to uniformly disperse the inorganic particles in the resin composition and measure the viscosity. Furthermore, ejection was impossible by either aerosol jet printing or inkjet printing. Comparative Example 3, which had a viscosity higher than that of the resin composition of the present invention, was unable to eject it by aerosol jet printing. In Comparative Example 4, the viscosity of the resin composition was too high to measure using an E-type viscometer at 25°C and 50 rpm. Furthermore, ejection was impossible by either aerosol jet printing or inkjet printing.

[0081] The disclosure of Japanese Patent Application No. 2022-187282 (filing date: November 24, 2022) is incorporated herein by reference in its entirety. All documents, patent applications, and technical standards mentioned herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. (A) Inorganic particles with an average particle size (D50) of 0.02 to 0.5 μm, (B) Polyfunctional thermosetting compounds, and (C) Hardener Includes, The viscosity measured using an E-type viscometer at 25°C and 50 rpm is 400 mPa·s or less. An insulating resin composition.

2. The insulating resin composition according to claim 1, wherein the inorganic particles (A) are surface-treated with a (meth)acrylic surface treatment agent.

3. (B) The insulating resin composition according to claim 1, wherein the polyfunctional thermosetting compound comprises a bifunctional thermosetting compound.

4. The insulating resin composition according to claim 1, further comprising (D) a monofunctional reactive diluent.

5. The insulating resin composition according to claim 4, wherein the content of (D) monofunctional reactive diluent is 40 to 80 parts by mass per 100 parts by mass of the total amount of (B) polyfunctional thermosetting compound, (C) curing agent, and (D) monofunctional reactive diluent.

6. The insulating resin composition according to claim 1, wherein the content of the inorganic particles (A) is 15 to 50 parts by mass per 100 parts by mass of the resin composition.

7. The insulating resin composition according to claim 1, which substantially does not contain particles with a particle size greater than 1.0 μm.

8. The insulating resin composition according to claim 1, for use in aerosol jet printing.

9. The insulating resin composition according to claim 1, for use in inkjet printing.

10. A cured product obtained by curing the insulating resin composition according to any one of claims 1 to 9.

11. An electronic component comprising the cured product described in claim 10.

12. A method for aerosol jet printing, comprising the step of aerosol jet printing an insulating resin composition according to any one of claims 1 to 9 onto a substrate.

13. An inkjet printing method comprising the step of inkjet printing an insulating resin composition according to any one of claims 1 to 9 onto a substrate.

14. Use of the insulating resin composition according to any one of claims 1 to 9 in aerosol jet printing.

15. Use of the insulating resin composition according to any one of claims 1 to 9 in inkjet printing.