Curable resin composition, cured product, adhesive, and adhesive film

Abstract

An object of the present application is to provide a curable resin composition which is excellent in heat resistance, thermal conductivity and adhesiveness. In addition, an object of the present application is to provide a cured product of the curable resin composition, and an adhesive and an adhesive film formed using the curable resin composition. The present application relates to a curable resin composition containing a curable resin, a curing agent including an imide oligomer, and a thermally conductive filler, the curable resin composition having a thermal conductivity of 1 W / m·K or more after curing.

Description

Technical Field

[0001] This invention relates to a curable resin composition exhibiting excellent heat resistance, thermal conductivity, and adhesive properties. Furthermore, this invention relates to cured products of the curable resin composition, as well as adhesives and adhesive films made using the cured resin composition. Background Technology

[0002] As a method for heat dissipation of electronic components, in general, a heat-dissipating material is introduced between the electronic component and a metal heat transfer plate to prevent heat generated by the electronic component from accumulating within the electronic component. As such heat-dissipating materials, adhesives using curable resin compositions with excellent thermal conductivity and heat resistance have been studied. Examples of curable resin compositions with excellent thermal conductivity and heat resistance include, for example, an adhesive composition containing epoxy resin and siloxane-modified polyamide-imide components disclosed in Patent Document 1, and a curable resin composition containing polyimide silicone resin having two or more phenolic hydroxyl groups per molecule and epoxy resin disclosed in Patent Document 2.

[0003] Existing technical documents

[0004] Patent documents

[0005] Patent Document 1: Japanese Patent Application Publication No. 2003-193016

[0006] Patent Document 2: Japanese Patent Application Publication No. 2005-113059 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] When using existing curable resin compositions disclosed in Patent Documents 1 and 2 as adhesives for electronic components, problems such as poor contact sometimes occur due to the adhesion of low molecular weight siloxane compounds from these compositions to the electronic components.

[0009] In contrast, while the aforementioned problems do not occur when using non-silicone materials, it is difficult to fully satisfy the requirements for heat resistance, thermal conductivity, and adhesion.

[0010] The object of this invention is to provide a curable resin composition with excellent heat resistance, thermal conductivity, and adhesive properties. Furthermore, the object of this invention is to provide a cured product of the curable resin composition, as well as adhesives and adhesive films made using the cured resin composition.

[0011] means for solving problems

[0012] This invention relates to a curable resin composition comprising a curable resin, a curing agent, and a thermally conductive filler, wherein the curing agent comprises an imide oligomer, and the cured curable resin composition has a thermal conductivity of 1 W / m·K or higher.

[0013] The present invention will now be described in detail.

[0014] The inventors discovered that by further adding a thermally conductive filler to a curable resin composition comprising a curable resin and an imide oligomer as a curing agent, the thermal conductivity of the cured resin composition becomes 1 W / m·K or higher, thereby obtaining a curable resin composition with excellent heat resistance, thermal conductivity and adhesion, thus completing the present invention.

[0015] The lower limit of the thermal conductivity of the cured resin composition of the present invention is 1 W / m·K. By achieving a thermal conductivity of 1 W / m·K or higher after curing, the cured resin composition of the present invention can be suitable for use as a heat-dissipating adhesive. The preferred lower limit of the thermal conductivity after curing is 1.5 W / m·K, and the more preferred lower limit is 2 W / m·K.

[0016] Furthermore, there is no particular upper limit to the preferred thermal conductivity after curing, but the practical upper limit is 20 W / m·K.

[0017] It should be noted that the above-mentioned thermal conductivity can be measured at 23°C according to ASTM D5470. For example, a measuring apparatus for measuring the above-mentioned thermal conductivity can be the "T3SterDynTIM Tester" from Mentor Siemens Business. Furthermore, the cured product for which the above-mentioned thermal conductivity is to be measured is a cured product obtained by drying a curable resin composition and then heating it at 190°C for 1 hour.

[0018] The curable resin composition of the present invention contains a curable resin.

[0019] Examples of curable resins include epoxy resins, cyanate ester resins, phenolic resins, polyimide resins, maleimide resins, benzoxazine resins, silicone resins, acrylic resins, and fluororesins. Preferably, the curable resin includes at least one selected from epoxy resins, cyanate ester resins, maleimide resins, and benzoxazine resins; more preferably, it includes epoxy resin. The curable resins can be used alone or in combination of two or more.

[0020] Examples of epoxy resins mentioned above include: bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol E type epoxy resin, bisphenol S type epoxy resin, 2,2'-diallyl bisphenol A type epoxy resin, hydrogenated bisphenol type epoxy resin, propylene oxide addition bisphenol A type epoxy resin, resorcinol type epoxy resin, biphenyl type epoxy resin, thioether type epoxy resin, diphenyl ether type epoxy resin, dicyclopentadiene type epoxy resin, naphthalene type epoxy resin, fluorene type epoxy resin, naphthylene ether type epoxy resin, phenolic resin, o-cresol phenolic resin, dicyclopentadiene phenolic resin, biphenyl phenolic resin, naphthol phenolic resin, glycidylamine type epoxy resin, alkyl polyol type epoxy resin, rubber modified epoxy resin, glycidyl ester compounds, etc. From the perspective of processability, epoxy resins that are liquid at 25°C are preferred, considering their low viscosity and ease of adjustment in curing properties. These epoxy resins can be used alone or in combination of two or more.

[0021] As described below, the curable resins described above preferably do not contain compounds having a siloxane backbone.

[0022] The curable resin composition of the present invention also contains a curing agent.

[0023] The curing agent described above contains an imide oligomer. By using the imide oligomer as the curing agent, the cured resin composition of the present invention exhibits excellent heat resistance.

[0024] The aforementioned imide oligomers preferably have reactive functional groups capable of reacting with the aforementioned curable resin.

[0025] The aforementioned reactive functional groups also depend on the type of curing resin used. When using epoxy resin as the curing resin, it is preferable to select at least one selected from acid anhydride groups, phenolic hydroxyl groups, and amino groups. Among these, acid anhydride groups or phenolic hydroxyl groups are particularly preferred from the perspective of storage stability and heat resistance.

[0026] The aforementioned imide oligomer preferably has the aforementioned reactive functional groups at the ends of the main chain, and more preferably has the aforementioned reactive functional groups at both ends of the main chain.

[0027] Specifically, the aforementioned imide oligomer preferably has a structure represented by formula (1-1) or formula (1-2), or formula (2-1) or formula (2-2). By having a structure represented by formula (1-1) or formula (1-2), or formula (2-1) or formula (2-2), the reactivity and compatibility of the aforementioned imide oligomer with the aforementioned curable resin become more excellent.

[0028] [Chemical Formula 1]

[0029]

[0030] In formulas (1-1) and (1-2), A is an acid dianhydride residue; in formula (1-1), B is an aliphatic diamine residue or an aromatic diamine residue; and in formula (1-2), Ar is a divalent aromatic group that can be substituted.

[0031] [Chemical Formula 2]

[0032]

[0033] In formulas (2-1) and (2-2), A is an acid dianhydride residue, B is an aliphatic triamine residue or an aromatic triamine residue, and Ar is a divalent aromatic group that can be substituted in formula (2-2).

[0034] The aforementioned dianhydride residues are preferably tetravalent groups represented by formula (3-1) or formula (3-2) below.

[0035] [Chemical Formula 3]

[0036]

[0037] In formulas (3-1) and (3-2), * indicates a bonding position. In formula (3-1), Z represents a bonding bond, an oxygen atom, a carbonyl group, a sulfur atom, a sulfonyl group, a straight-chain or branched divalent hydrocarbon group, or a divalent group with an aromatic ring. When Z is a hydrocarbon group, an oxygen atom may be present between the hydrocarbon group and each aromatic ring in formula (3-1). When Z is a divalent group with an aromatic ring, an oxygen atom may be present between the divalent group with the aromatic ring and each aromatic ring in formula (3-1). The hydrogen atoms in the aromatic rings of formulas (3-1) and (3-2) may be substituted.

[0038] In the case that Z in the above formula (3-1) is a straight-chain or branched divalent hydrocarbon group, or a divalent group with an aromatic ring, these groups can be substituted.

[0039] Examples of substituents that can be used as straight-chain or branched divalent hydrocarbon groups, or where the divalent groups having aromatic rings are replaced, include: halogen atoms, straight-chain or branched alkyl groups, straight-chain or branched alkenyl groups, alicyclic groups, aryl groups, alkoxy groups, nitro groups, cyano groups, etc.

[0040] Examples of acid dianhydrides that serve as the source of the aforementioned acid dianhydride residues include, for example, the acid dianhydrides represented by formula (9) described later.

[0041] When B in formula (1-1) is an aliphatic diamine residue, or when B in formula (2-1) or formula (2-2) is an aliphatic triamine residue, the preferred lower limit for the number of carbon atoms in the aliphatic diamine residue and the aliphatic triamine residue is 4. By making the number of carbon atoms in the aliphatic diamine residue and the aliphatic triamine residue 4 or more, the resulting curable resin composition exhibits improved flexibility and processability before curing, as well as superior dielectric properties after curing. A more preferred lower limit for the number of carbon atoms in the aliphatic diamine residue and the aliphatic triamine residue is 5, and a further preferred lower limit is 6.

[0042] Furthermore, there is no particular upper limit on the preferred number of carbon atoms of the aforementioned aliphatic diamine residues and aliphatic triamine residues; the practical upper limit is 60.

[0043] Examples of aliphatic diamines that can serve as sources of the aforementioned aliphatic diamine residues include: aliphatic diamines derived from dimer acids, straight-chain or branched aliphatic diamines, aliphatic ether diamines, and aliphatic cycloaliphatic diamines.

[0044] Examples of aliphatic diamines derived from dimer acids include: dimeric diamine (Japanese: ダイマージアミン), hydrogenated dimeric diamine, etc.

[0045] Examples of the aforementioned straight-chain or branched aliphatic diamines include: 1,4-butanediamine, 1,6-hexanediamine, 1,8-octanediamine, 1,9-nonanediamine, 1,10-decanediamine, 1,11-undecanediamine, 1,12-dodecanediamine, 1,14-tetradecanediamine, 1,16-hexadecanediamine, 1,18-octadecanediamine, 1,20-eicosanediamine, 2-methyl-1,8-octanediamine, 2-methyl-1,9-nonanediamine, and 2,7-dimethyl-1,8-octanediamine.

[0046] Examples of aliphatic ether diamines include 2,2'-oxobis(ethylamine), 3,3'-oxobis(propylamine), and 1,2-bis(2-aminoethoxy)ethane.

[0047] Examples of the aforementioned aliphatic cyclohexane diamines include 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, cyclohexanediamine, methylcyclohexanediamine, isophoronediamine, etc.

[0048] The aliphatic diamine residues mentioned above are preferably aliphatic diamine residues derived from dimer acids.

[0049] Examples of aliphatic triamines that can serve as sources of the aforementioned aliphatic triamine residues include: aliphatic triamines derived from trimeric acids, straight-chain or branched aliphatic triamines, aliphatic ether triamines, and aliphatic cycloaliphatic triamines.

[0050] Examples of aliphatic triamines derived from trimeric acids include melamine and hydrogenated melamine.

[0051] Examples of straight-chain or branched aliphatic triamines include: 3,3'-diamino-N-methyldipropylamine, 3,3'-diaminodipropylamine, diethylenetriamine, bis(hexamethylene)triamine, 2,2'-bis(methylamino)-N-methyldiethylamine, etc.

[0052] The aliphatic triamine residues mentioned above are preferably the aliphatic triamine residues derived from trimeric acids.

[0053] Alternatively, a mixture of the above-mentioned dimeric diamine and the above-mentioned melamine can also be used as the above-mentioned aliphatic diamine and / or the above-mentioned aliphatic triamine.

[0054] Commercially available products derived from dimer acids and / or triazomeric diamines and / or triamines derived from trimer acids include, for example, aliphatic diamines and / or triamines manufactured by BASF, aliphatic diamines and / or triamines manufactured by Croda, etc.

[0055] Examples of aliphatic diamines and / or aliphatic triamines manufactured by BASF include Versamine 551 and Versamine 552.

[0056] Examples of aliphatic diamines and / or aliphatic triamines manufactured by Croda include Priamine 1071, Priamine 1073, Priamine 1074, and Priamine 1075.

[0057] In the case where B in formula (1-1) is an aromatic diamine residue, the aromatic diamine residue is preferably a divalent group represented by formula (4-1) or formula (4-2).

[0058] [Chemical Formula 4]

[0059]

[0060] In formulas (4-1) and (4-2), * indicates a bonding position. In formula (4-1), Y is a bonding bond, an oxygen atom, a carbonyl group, a sulfur atom, a sulfonyl group, a straight-chain or branched divalent hydrocarbon group, or a divalent group with an aromatic ring. When Y is a hydrocarbon group, an oxygen atom may be present between the hydrocarbon group and each aromatic ring in formula (4-1). When Y is a divalent group with an aromatic ring, an oxygen atom may be present between the divalent group with an aromatic ring and each aromatic ring in formula (4-1). The hydrogen atoms of the aromatic rings in formulas (4-1) and (4-2) may be substituted.

[0061] In the case that Y in the above formula (4-1) is a straight-chain or branched divalent hydrocarbon group, or a divalent group with an aromatic ring, these groups can be substituted.

[0062] Examples of substituents that can be used as straight-chain or branched divalent hydrocarbon groups, or where the divalent groups having aromatic rings are replaced, include: halogen atoms, straight-chain or branched alkyl groups, straight-chain or branched alkenyl groups, alicyclic groups, aryl groups, alkoxy groups, nitro groups, cyano groups, etc.

[0063] Aromatic diamines that serve as the source of the aforementioned aromatic diamine residues include, for example, aromatic diamines in the case where the diamine represented by formula (10) described later is an aromatic diamine.

[0064] As described below, the curing agent preferably does not contain compounds having a siloxane backbone. In particular, when the imide oligomer has a siloxane backbone in its structure, it may lower the glass transition temperature of the cured resin composition or contaminate the adherends, thus causing poor adhesion. Therefore, it is preferable to use an imide oligomer that does not have a siloxane backbone in its structure.

[0065] The molecular weight of the aforementioned imide oligomer is preferably 5000 or less. By setting the molecular weight of the aforementioned imide oligomer to 5000 or less, the long-term heat resistance of the cured resin composition becomes more excellent. A more preferred upper limit for the molecular weight of the aforementioned imide oligomer is 4000, and a further preferred upper limit is 3000.

[0066] In particular, regarding the molecular weight of the aforementioned imide oligomers, when having structures represented by formulas (1-1) and (2-1) above, it is preferably 900 or more and 5000 or less; when having structures represented by formulas (1-2) and (2-2) above, it is preferably 550 or more and 4000 or less. A more preferred lower limit for the molecular weight when having structures represented by formulas (1-1) and (2-1) above is 950, and a further preferred lower limit is 1000. A more preferred lower limit for the molecular weight when having structures represented by formulas (1-2) and (2-2) above is 580, and a further preferred lower limit is 600.

[0067] It should be noted that, in this specification, the term "molecular weight" refers to the molecular weight determined from the structural formula for compounds with a defined molecular structure. However, for compounds with a broad degree of polymerization or unspecified modification sites, number-average molecular weight is sometimes used. Furthermore, the aforementioned "number-average molecular weight" is a value obtained by gel permeation chromatography (GPC) using tetrahydrofuran as a solvent and converting it to polystyrene. Examples of columns used for determining the number-average molecular weight based on polystyrene conversion using GPC include JAIGEL-2H-A (manufactured by Nippon Analytical Industries Co., Ltd.).

[0068] The aforementioned imide oligomers are preferably imide oligomers represented by the following formulas (5-1), (5-2), (5-3), (5-4), or (5-5), or imide oligomers represented by the following formulas (6-1), (6-2), (6-3), (6-4), (6-5), or (6-6).

[0069] [Chemical Formula 5]

[0070]

[0071] In formulas (5-1) to (5-5), A is the aforementioned dianhydride residue. In formulas (5-1) to (5-5), A can be the same or different. In formulas (5-1) to (5-4), B is the aforementioned aliphatic diamine residue or the aforementioned aromatic diamine residue. In formulas (5-3) and (5-4), B can be the same or different. In formula (5-5), B is the aforementioned aliphatic triamine residue or the aforementioned aromatic triamine residue. In formula (5-2), X is a hydrogen atom, a halogen atom, or a monovalent hydrocarbon group that can be substituted. In formula (5-4), W is a hydrogen atom, a halogen atom, or a monovalent hydrocarbon group that can be substituted. In formulas (5-3) and (5-4), n is the number of repetitions.

[0072] [Chemical Formula 6]

[0073]

[0074] In formulas (6-1) to (6-6), A is the aforementioned dianhydride residue. In formulas (6-1) to (6-6), A can be the same or different. In formulas (6-1) to (6-6), R is a hydrogen atom, a halogen atom, or a monovalent hydrocarbon group that can be substituted. In formulas (6-1), (6-2), (6-4), and (6-6), R can be the same or different. In formulas (6-3) and (6-5), W is a hydrogen atom, a halogen atom, or a monovalent hydrocarbon group that can be substituted. In formulas (6-2) to (6-4), B is the aforementioned aliphatic diamine residue or the aforementioned aromatic diamine residue. In formulas (6-4) and (6-5), B can be the same or different. In formula (6-6), B is the aforementioned aliphatic triamine residue or the aforementioned aromatic triamine residue.

[0075] In formulas (5-1) to (5-5) and formulas (6-1) to (6-6) above, A is preferably a tetravalent group represented by formula (7-1) or formula (7-2) below.

[0076] [Chemical Formula 7]

[0077]

[0078] In formulas (7-1) and (7-2), * indicates a bonding position. In formula (7-1), Z represents a bonding bond, an oxygen atom, a carbonyl group, a sulfur atom, a sulfonyl group, a straight-chain or branched divalent hydrocarbon group, or a divalent group with an aromatic ring. When Z is a hydrocarbon group, an oxygen atom may be present between the hydrocarbon group and each aromatic ring in formula (7-1). When Z is a divalent group with an aromatic ring, an oxygen atom may be present between the divalent group with an aromatic ring and each aromatic ring in formula (7-1). The hydrogen atoms in the aromatic rings of formulas (7-1) and (7-2) may be substituted.

[0079] In formulas (5-1) to (5-4) and formulas (6-2) to (6-5) above, B is preferably a divalent group represented by formula (8-1) or formula (8-2) below.

[0080] [Chemical Formula 8]

[0081]

[0082] In formulas (8-1) and (8-2), * indicates a bonding position. In formula (8-1), Y is a bonding bond, an oxygen atom, a carbonyl group, a sulfur atom, a sulfonyl group, a straight-chain or branched divalent hydrocarbon group, or a divalent group with an aromatic ring. When Y is a hydrocarbon group, an oxygen atom may be present between the hydrocarbon group and each aromatic ring in formula (8-1). When Y is a divalent group with an aromatic ring, an oxygen atom may be present between the divalent group with an aromatic ring and each aromatic ring in formula (8-1). The hydrogen atoms of the aromatic rings in formulas (8-1) and (8-2) may be substituted.

[0083] As a method for manufacturing an imide oligomer having the structure represented by formula (1-1) above, for example, a method of reacting an acid dianhydride represented by formula (9) below with a diamine represented by formula (10) below is provided. In addition, by using an aliphatic triamine or an aromatic triamine instead of the diamine represented by formula (10) below, an imide oligomer having the structure represented by formula (2-1) above can be manufactured.

[0084] [Chemical Formula 9]

[0085]

[0086] In formula (9), A is the same tetravalent group as A in formula (1-1) above.

[0087] [Chemical Formula 10]

[0088]

[0089] In formula (10), B is the same divalent group as B in formula (1-1) above, and R 1 ~R 4 Each can be an independent hydrogen atom or a monovalent hydrocarbon group.

[0090] The following is a specific example of a method for reacting the acid dianhydride represented by formula (9) above with the diamine represented by formula (10) above.

[0091] Examples include: First, dissolving the diamine represented by formula (10) in a solvent (e.g., N-methylpyrrolidone) that can dissolve the amic acid oligomer obtained by the reaction, then adding the acid dianhydride represented by formula (9) to the resulting solution and reacting to obtain an amic acid oligomer solution. Next, removing the solvent by heating or reducing pressure, and further heating at about 200°C or higher for more than 1 hour to allow the amic acid oligomer to react. By adjusting the molar ratio of the acid dianhydride represented by formula (9) to the diamine represented by formula (10) and the imidization conditions, an imide oligomer with a desired number-average molecular weight and a structure represented by formula (1-1) at both ends can be obtained.

[0092] Furthermore, by replacing a portion of the dianhydride represented by formula (9) above with the anhydride represented by formula (11) below, an imide oligomer with a desired number-average molecular weight, having a structure represented by formula (1-1) above at one end and a structure derived from the anhydride represented by formula (11) below at the other end, can be obtained. In this case, the dianhydride represented by formula (9) above and the anhydride represented by formula (11) below can be added simultaneously or separately.

[0093] Furthermore, by replacing a portion of the diamine represented by formula (10) above with a monoamine represented by formula (12) below, it is possible to obtain an imide oligomer having a desired number-average molecular weight, a structure represented by formula (1-1) above at one end, and a structure derived from the monoamine represented by formula (12) below at the other end. In this case, the diamine represented by formula (10) above and the monoamine represented by formula (12) below can be added simultaneously or separately.

[0094] [Chemical Formula 11]

[0095]

[0096] In equation (11), Ar is a divalent aromatic group that can be substituted.

[0097] [Chemical Formula 12]

[0098]

[0099] In equation (12), Ar is a monovalent aromatic group that can be substituted, and R 5 and R 6 Each can be an independent hydrogen atom or a monovalent hydrocarbon group.

[0100] As a method for manufacturing an imide oligomer having the structure represented by formula (1-2) above, examples include: reacting an acid dianhydride represented by formula (9) above with a phenolic hydroxyl monoamine represented by formula (13) below; or reacting an acid dianhydride represented by formula (9), a diamine represented by formula (10) above, and a phenolic hydroxyl monoamine represented by formula (13) below. Furthermore, by using an aliphatic triamine or an aromatic triamine instead of the diamine represented by formula (10) above, an imide oligomer having the structure represented by formula (2-2) above can be manufactured.

[0101] [Chemical Formula 13]

[0102]

[0103] In equation (13), Ar is a divalent aromatic group that can be substituted, and R 7 and R 8 Each can be an independent hydrogen atom or a monovalent hydrocarbon group.

[0104] The following is a specific example of a method for reacting the acid dianhydride represented by formula (9) above with the phenolic hydroxy monoamine represented by formula (13) above.

[0105] Examples include: First, dissolving the phenolic hydroxy monoamine represented by formula (13) in a solvent (e.g., N-methylpyrrolidone) that can dissolve the amic acid oligomer obtained by the reaction, then adding the acid dianhydride represented by formula (9) to the resulting solution and reacting to obtain an amic acid oligomer solution. Next, removing the solvent by heating or reducing pressure, and further heating at about 200°C or higher for at least 1 hour to react the amic acid oligomer. By adjusting the molar ratio of the acid dianhydride represented by formula (9) to the phenolic hydroxy monoamine represented by formula (13) and the imidization conditions, imide oligomers with desired number-average molecular weights and structures represented by formulas (1-2) at both ends can be obtained.

[0106] Furthermore, by replacing a portion of the phenolic hydroxy monoamine represented by formula (13) with the monoamine represented by formula (12), an imide oligomer with a desired number-average molecular weight, having a structure represented by formula (1-2) at one end and a structure derived from the monoamine represented by formula (12) at the other end, can be obtained. In this case, the phenolic hydroxy monoamine represented by formula (13) and the monoamine represented by formula (12) can be added simultaneously or separately.

[0107] The following are specific examples of methods for reacting the acid dianhydride represented by formula (9), the diamine represented by formula (10), and the phenolic hydroxy monoamine represented by formula (13).

[0108] Examples include: First, dissolving the phenolic hydroxyl monoamine represented by formula (13) and the diamine represented by formula (10) in a solvent (e.g., N-methylpyrrolidone) that can dissolve the amic acid oligomer obtained by the reaction, and then adding the acid dianhydride represented by formula (9) to the resulting solution to react and obtain an amic acid oligomer solution. Next, removing the solvent by heating or reducing pressure, and then further heating at about 200°C or higher for more than 1 hour to react the amic acid oligomer. By adjusting the molar ratio of the acid dianhydride represented by formula (9), the diamine represented by formula (10), and the phenolic hydroxyl monoamine represented by formula (13), as well as the imidization conditions, it is possible to obtain an imide oligomer with a desired number-average molecular weight and a structure represented by formulas (1-2) at both ends.

[0109] Furthermore, by replacing a portion of the phenolic hydroxy monoamine represented by formula (13) with the monoamine represented by formula (12), an imide oligomer with a desired number-average molecular weight, having a structure represented by formula (1-2) at one end and a structure derived from the monoamine represented by formula (12) at the other end, can be obtained. In this case, the phenolic hydroxy monoamine represented by formula (13) and the monoamine represented by formula (12) can be added simultaneously or separately.

[0110] Examples of acid dianhydrides represented by the above formula (9) include: pyromellitic dianhydride, 3,3'-oxophthalic anhydride, 3,4'-oxophthalic anhydride, 4,4'-oxophthalic anhydride, 4,4'-(4,4'-isopropylidene diphenoxy) phthalic anhydride, 4,4'-bis(2,3-dicarboxyphenoxy) diphenyl ether dianhydride, p-phenylene-bisphenyltriester dianhydride, 2,3,3',4'-biphenyltetramethylcarboxylic acid dianhydride, etc.

[0111] From the perspective of superior solubility and heat resistance, the dianhydride used as a raw material for the above-mentioned imide oligomers is preferably an aromatic dianhydride with a melting point of 240°C or less, more preferably an aromatic dianhydride with a melting point of 220°C or less, and even more preferably an aromatic dianhydride with a melting point of 200°C or less. Particularly preferred are 3,4'-oxophthalic anhydride (melting point 180°C) and 4,4'-(4,4'-isopropylidenediphenoxy)phthalic anhydride (melting point 190°C).

[0112] It should be noted that, in this specification, the term "melting point" refers to the value measured using a differential scanning calorimeter as the temperature of the endothermic peak when the temperature is increased at a rate of 10 °C / min. Examples of such differential scanning calorimeters include the EXTEAR DSC6100 (manufactured by SII Nano Technology).

[0113] Among the diamines represented by the above formula (10), examples of aromatic diamines include: 3,3'-diaminodiphenylmethane, 3,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylmethane, 3,3'-diaminodiphenyl ether, 3,4'-diaminodiphenyl ether, 4,4'-diaminodiphenyl ether, o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 3,3'-diaminodiphenyl sulfone, 4,4'-diaminodiphenyl sulfone, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, 1,4-bis(4-aminophenoxy)benzene, bis(4-(4-aminophenoxy)phenyl)methane, 2,2-bis(4-aminophenoxy)phenylmethane, etc. 1,3-(4-aminophenoxy)phenyl)propane, 1,4-bis(2-(4-aminophenyl)-2-propyl)benzene, 1,4-bis(2-(4-aminophenyl)-2-propyl)benzene, 3,3'-diamino-4,4'-dihydroxyphenylmethane, 4,4'-diamino-3,3'-dihydroxyphenylmethane, 3,3'-diamino-4,4'-dihydroxyphenyl ether, bisaminophenylfluorene, bitoluidine fluorene, 4,4'-bis(4-aminophenoxy)biphenyl, 4,4'-diamino-3,3'-dihydroxyphenyl ether, 3,3'-diamino-4,4'-dihydroxybiphenyl, 4,4'-diamino-2,2'-dihydroxybiphenyl, etc. From the perspective of excellent availability, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenyl ether, 1,3-bis(2-(4-aminophenyl)-2-propyl)benzene, 1,4-bis(2-(4-aminophenyl)-2-propyl)benzene, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, and 1,4-bis(4-aminophenoxy)benzene are preferred. Furthermore, from the perspective of excellent solubility and heat resistance, 1,3-bis(2-(4-aminophenyl)-2-propyl)benzene, 1,4-bis(2-(4-aminophenyl)-2-propyl)benzene, 1,3-bis(3-aminophenoxy)benzene, 1,3-bis(4-aminophenoxy)benzene, and 1,4-bis(4-aminophenoxy)benzene are more preferred.

[0114] Examples of acid anhydrides represented by the above formula (11) include: phthalic anhydride, 3-methyl phthalic anhydride, 4-methyl phthalic anhydride, 1,2-naphthalenedicarboxylic anhydride, 2,3-naphthalenedicarboxylic anhydride, 1,8-naphthalenedicarboxylic anhydride, 2,3-anthracitenic anhydride, 4-tert-butyl phthalic anhydride, 4-ethynyl phthalic anhydride, 4-phenylethynyl phthalic anhydride, 4-fluorophthalic anhydride, 4-chlorophthalic anhydride, 4-bromophthalic anhydride, 3,4-dichlorophthalic anhydride, etc.

[0115] Examples of monoamines represented by the above formula (12) include: aniline, o-toluidine, m-toluidine, p-toluidine, 2,4-dimethylaniline, 3,4-dimethylaniline, 3,5-dimethylaniline, 2-tert-butylaniline, 3-tert-butylaniline, 4-tert-butylaniline, 1-naphthylamine, 2-naphthylamine, 1-aminoanthracene, 2-aminoanthracene, 9-aminoanthracene, 1-aminopyrene, 3-chloroaniline, o-anisinylamine, m-anisinylamine, p-anisinylamine, 1-amino-2-methylnaphthalene, 2,3-dimethylaniline, 2,4-dimethylaniline, 2,5-dimethylaniline, 3,4-dimethylaniline, 4-ethylaniline, 4-ethynylaniline, 4-isopropylaniline, 4-(methylthio)aniline, N,N-dimethyl-1,4-phenylenediamine, etc.

[0116] Examples of phenolic hydroxyl monoamines represented by formula (13) include: 3-aminophenol, 4-aminophenol, 4-amino-o-cresol, 5-amino-o-cresol, 4-amino-2,3-xylenol, 4-amino-2,5-xylenol, 4-amino-2,6-xylenol, 4-amino-1-naphthol, 5-amino-2-naphthol, 6-amino-1-naphthol, and 4-amino-2,6-diphenylphenol. Among these, 4-amino-o-cresol and 5-amino-o-cresol are preferred from the perspectives of excellent availability and storage stability, and the ability to obtain a high glass transition temperature after curing.

[0117] When the above-described manufacturing method is used to manufacture the imide oligomer, the imide oligomer is obtained in the form of a mixture (imide oligomer composition) comprising a variety of imide oligomers having the structure represented by formula (1-1) or a variety of imide oligomers having the structure represented by formula (1-2) and each raw material. When an aliphatic triamine or aromatic triamine is used instead of the diamine represented by formula (10), the imide oligomer is obtained in the form of a mixture (imide oligomer composition) comprising a variety of imide oligomers having the structure represented by formula (2-1) or a variety of imide oligomers having the structure represented by formula (2-2) and each raw material. For this imide oligomer composition, by achieving an imidization rate of 70% or more, a cured product with superior mechanical strength at high temperatures and long-term heat resistance can be obtained when used as a curing agent.

[0118] The preferred lower limit for the imidization rate of the above-mentioned imide oligomer composition is 75%, and a more preferred lower limit is 80%. Furthermore, there is no particular limitation on the preferred upper limit for the imidization rate of the above-mentioned imide oligomer composition, but a substantial upper limit is 98%.

[0119] It should be noted that the above "imidization rate" can be derived as follows: It is measured using a Fourier transform infrared spectrophotometer (FT-IR) via total reflectance measurement (ATR method), based on the 1660 cm⁻¹ value from the carbonyl group of the amide acid. -1 The peak absorbance area is derived using the following formula. Examples of Fourier transform infrared spectrophotometers include the UMA600 (manufactured by Agilent Technologies). It should be noted that the "peak absorbance area of ​​the amyl acid oligomer" in the following formula is the absorbance area of ​​the amyl acid oligomer obtained by reacting an acid dianhydride with a diamine or a phenolic hydroxyl monoamine, without imidization, by removing the solvent through evaporation or the like.

[0120] Imidization rate (%) = 100 × (1 - (peak absorbance area after imidization) / (peak absorbance area of ​​the amyl acid oligomer))

[0121] From the viewpoint of solubility in the curable resin composition, the above-mentioned imide oligomer composition is preferably soluble at 3g or more relative to 10g of tetrahydrofuran at 25°C.

[0122] The preferred lower limit for the content of the imide oligomer in 100 parts by weight of the total amount of the curable resin and the curing agent (including a curing accelerator if it contains a curing accelerator described later) is 20 parts by weight, and the preferred upper limit is 80 parts by weight. By setting the content of the imide oligomer within this range, the resulting curable resin composition exhibits superior flexibility and processability before curing, as well as improved heat resistance after curing. A more preferred lower limit for the content of the imide oligomer is 25 parts by weight, and a more preferred upper limit is 75 parts by weight.

[0123] It should be noted that when the imide oligomer of the present invention is included in the above-mentioned imide oligomer composition, the content of the imide oligomer refers to the content of the imide oligomer composition (or the total content of the imide oligomer composition and other imide oligomers when other imide oligomers are also used in combination).

[0124] The aforementioned curable resin and curing agent preferably do not contain compounds having a siloxane backbone. By ensuring that the aforementioned curable resin and curing agent do not contain compounds having a siloxane backbone, it is possible to prevent poor contact and other issues caused by low molecular weight siloxane compounds from the curable resin composition.

[0125] The curable resin composition of the present invention contains a thermally conductive filler. By containing the aforementioned thermally conductive filler, the thermal conductivity of the curable resin composition of the present invention becomes excellent.

[0126] It should be noted that, in this specification, the term "thermally conductive filler" refers to filler with a thermal conductivity of 10 W / m·K or higher.

[0127] From the viewpoint of thermal conductivity, the aforementioned thermally conductive filler preferably includes at least one selected from alumina, aluminum nitride, silicon carbide, boron nitride, magnesium oxide, zinc oxide, boron carbide, titanium carbide, zirconium oxide, aluminum, and diamond.

[0128] Examples of the shapes of the aforementioned thermally conductive fillers include: plate-shaped, spherical, irregular, fragmented, and polygonal shapes. Furthermore, the aforementioned thermally conductive fillers can be aggregated particles formed by the aggregation of primary particles, such as plate-shaped fillers.

[0129] The preferred lower limit for the average particle size of the aforementioned thermally conductive filler is 0.1 μm, and the preferred upper limit is 300 μm. By setting the average particle size of the aforementioned thermally conductive filler within this range, the coatability and thermal conductivity of the resulting curable resin composition become more excellent. A more preferred lower limit for the average particle size of the aforementioned thermally conductive filler is 0.2 μm, and a more preferred upper limit is 200 μm.

[0130] It should be noted that the average particle size of the above-mentioned thermally conductive filler can be measured by dispersing the thermally conductive filler in a solvent (water, organic solvent, etc.) using a particle size distribution measuring device such as NICOMP 380ZLS (manufactured by PARTICLESIZING SYSTEMS).

[0131] The preferred lower limit for the content of the thermally conductive filler (excluding the solvent) in the curable resin composition of the present invention is 50% by volume. By making the content of the thermally conductive filler 50% by volume or more, the thermal conductivity of the obtained curable resin composition becomes more excellent. The more preferred lower limit for the content of the thermally conductive filler is 60% by volume.

[0132] Furthermore, from the viewpoint of coatability and adhesion, the preferred upper limit of the content ratio of the above-mentioned thermally conductive filler is 95% by volume, and the more preferred upper limit is 90% by volume.

[0133] To the extent that it does not impede the purpose of the present invention, in addition to the thermally conductive fillers described above, the curable resin composition of the present invention may also contain other fillers with a thermal conductivity of less than 10 W / m·K.

[0134] Inorganic or organic fillers can be used as other fillers mentioned above.

[0135] Examples of inorganic fillers include silica, barium sulfate, glass powder, glass frit, glass fiber, and inorganic ion exchangers. Among these, silica and barium sulfate are preferred.

[0136] Examples of organic fillers include silicone rubber particles, acrylic rubber particles, urethane rubber particles, polyamide particles, polyamide-imide particles, polyimide particles, benzoguanidine particles, and their core-shell particles. Among these, polyamide particles, polyamide-imide particles, and polyimide particles are preferred.

[0137] The other fillers mentioned above can be used individually or in combination of two or more.

[0138] The curable resin composition of the present invention preferably contains a dispersant.

[0139] By including the above-mentioned dispersant, the curable resin composition of the present invention can easily achieve a uniform dispersion of the above-mentioned thermally conductive filler.

[0140] Examples of dispersants mentioned above include: modified polyester compounds, modified polyether compounds, phosphate esters of modified polyether compounds, fatty acid derivatives, fatty acid polycarboxylic acid amine salts, cationic acrylic polymers, and polyurethane compounds. These dispersants can be used alone or in combination of two or more.

[0141] The preferred lower limit of the content of the dispersant in 100 parts by weight of the curable resin composition of the present invention is 0.05 parts by weight, and the preferred upper limit is 4 parts by weight. By setting the content of the dispersant within this range, it is easier to achieve a uniform dispersion of the thermally conductive filler. A more preferred lower limit of the content of the dispersant is 0.1 parts by weight, and a more preferred upper limit is 3 parts by weight.

[0142] The curable resin composition of the present invention preferably contains a curing accelerator. By containing the above-mentioned curing accelerator, the curing time can be shortened and the productivity improved.

[0143] Examples of curing accelerators include imidazole-based, tertiary amine-based, phosphine-based, phosphorus-based, photoalkali-generating agents, and sulfonium salt-based curing accelerators. Among these, imidazole-based curing accelerators are preferred from the perspective of excellent storage stability. These curing accelerators can be used alone or in combination of two or more.

[0144] Relative to a total of 100 parts by weight of the aforementioned curing resin, curing agent, and curing accelerator, the preferred lower limit for the content of the curing accelerator is 0.01 parts by weight, and the preferred upper limit is 10 parts by weight. By setting the content of the curing accelerator within this range, the effect of shortening the curing time while maintaining excellent adhesion becomes even better. A more preferred lower limit for the content of the curing accelerator is 0.05 parts by weight, and a more preferred upper limit is 5 parts by weight.

[0145] To the extent that it does not impede the objectives of the present invention, the curable resin composition of the present invention may contain a polymer component. This polymer component functions as a film-forming component, and by using this polymer component, the processability of the obtained curable resin composition during film formation can be improved.

[0146] The preferred lower limit for the number-average molecular weight of the aforementioned polymer components is 5,000, and the preferred upper limit is 100,000. By setting the number-average molecular weight of the aforementioned polymer components within this range, the resulting curable resin composition exhibits superior flexibility and processability before curing, as well as improved heat resistance after curing. A more preferred lower limit for the number-average molecular weight of the aforementioned polymer components is 8,000, and a more preferred upper limit is 80,000.

[0147] Examples of the aforementioned polymer components include: polyimide, phenoxy resin, polyamide, polyamide-imide, polymaleimide, cyanate ester resin, benzoxazine resin, acrylic resin, urethane resin, polyester, etc. Among these, phenoxy resin and polyimide are preferred from the viewpoint of heat resistance and processability, and polyimide is more preferred. The aforementioned polymer components can be used alone or in combination of two or more.

[0148] Relative to a total of 100 parts by weight of the aforementioned curable resin, curing agent (including the curing accelerator if present), and polymer component, the preferred lower limit of the content of the polymer component is 0.5 parts by weight, and the preferred upper limit is 50 parts by weight. By setting the content of the polymer component within this range, the heat resistance of the cured product of the obtained curable resin composition becomes more excellent. A more preferred lower limit of the content of the polymer component is 1 part by weight, and a more preferred upper limit is 40 parts by weight.

[0149] From the viewpoints of coatability and processability, the above-mentioned curable resin composition may contain solvents or reactive diluents.

[0150] From the perspectives of coating properties and storage stability, solvents with a boiling point of less than 200°C are preferred as the aforementioned solvents.

[0151] Examples of solvents with boiling points below 200°C include: alcohol solvents, ketone solvents, ester solvents, hydrocarbon solvents, halogen solvents, ether solvents, and nitrogen-containing solvents.

[0152] Examples of alcohol solvents mentioned above include methanol, ethanol, isopropanol, n-propanol, isobutanol, n-butanol, tert-butanol, and 2-ethylhexanol.

[0153] Examples of ketone solvents mentioned above include acetone, methyl ethyl ketone, methyl isobutyl ketone, methyl propyl ketone, diisobutyl ketone, cyclohexanone, methyl cyclohexanone, and diacetone alcohol.

[0154] Examples of ester solvents mentioned above include: methyl acetate, ethyl acetate, butyl acetate, isobutyl acetate, methoxybutyl acetate, amyl acetate, n-propyl acetate, isopropyl acetate, methyl lactate, ethyl lactate, butyl lactate, etc.

[0155] Examples of hydrocarbon solvents mentioned above include: benzene, toluene, xylene, n-hexane, isohexane, cyclohexane, methylcyclohexane, ethylcyclohexane, isooctane, n-decane, n-heptane, etc.

[0156] Examples of halogen solvents mentioned above include dichloromethane, chloroform, and trichloroethane.

[0157] Examples of ether solvents mentioned above include: diethyl ether, tetrahydrofuran, 1,4-dioxane, 1,3-dioxolane, diisopropyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, propylene glycol monomethyl ether acetate, propylene glycol monomethyl ether, 3-methoxy-3-methyl-1-butanol, ethylene glycol monotert-butyl ether, propylene glycol monomethyl ether propionate, 3-methoxybutanol, diethylene glycol dimethyl ether, anisole, 4-methylanisole, etc.

[0158] Examples of nitrogen-containing solvents mentioned above include acetonitrile, N,N-dimethylformamide, N,N-dimethylacetamide, and N-methylpyrrolidone.

[0159] From the viewpoints of processability and solubility of imide oligomers, at least one solvent selected from ketone solvents with a boiling point of 60°C or higher and less than 200°C, ester solvents with a boiling point of 60°C or higher and less than 200°C, and ether solvents with a boiling point of 60°C or higher and less than 200°C is preferred. Examples of such solvents include methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, isobutyl acetate, 1,4-dioxane, 1,3-dioxolane, tetrahydrofuran, cyclohexanone, methylcyclohexanone, diethylene glycol dimethyl ether, and anisole.

[0160] It should be noted that the "boiling point" mentioned above refers to the value measured under conditions of 101 kPa, or the value converted to 101 kPa using a boiling point conversion chart or similar method.

[0161] As the above-mentioned reactive diluent, a reactive diluent having one or more reactive functional groups in one molecule is preferred.

[0162] Examples of reactive diluents having one or more reactive functional groups in one molecule include monofunctional epoxy resins.

[0163] Examples of monofunctional epoxy resins include monoglycidyl compounds and monoalicyclic epoxy compounds.

[0164] Examples of the aforementioned monoglycidyl compounds include: tert-butylphenyl glycidyl ether, 2-ethylhexyl glycidyl ether, allyl glycidyl ether, phenyl glycidyl ether, 3-epoxypropoxypropyltrimethoxysilane, 3-epoxypropoxypropylmethyldimethoxysilane, 1-(3-epoxypropoxypropyl)1,1,3,3,3-pentamethyldisiloxane, N-glycidyl-N,N-bis[3-(trimethoxysilyl)propyl]amine, etc.

[0165] Examples of the aforementioned monoalicyclic epoxy compounds include 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane. These reactive diluents can be used alone or in combination of two or more.

[0166] The preferred lower limit for the content of the solvent or reactive diluent in 100 parts by weight of the curable resin composition of the present invention is 0.5 parts by weight, and the preferred upper limit is 30 parts by weight. By setting the content of the solvent within this range, the coating properties and other properties of the resulting curable resin composition become more excellent. The more preferred lower limit for the content of the solvent or reactive diluent is 1 part by weight, and the more preferred upper limit is 20 parts by weight.

[0167] Without hindering the purpose of the present invention, the curable resin composition of the present invention may further contain additives such as coupling agents, storage stabilizers, anti-exudants, fluxes, and leveling agents.

[0168] The curable resin composition of the present invention preferably does not contain compounds having an amide backbone. When compounds having an amide backbone are included, the viscosity of the curable resin composition sometimes increases due to the hydrogen bonding of the amide groups, making it difficult to achieve high filling of thermally conductive fillers and resulting in lower thermal conductivity. Additionally, the water absorption sometimes increases, leading to reduced adhesive strength after moisture absorption.

[0169] As a method for manufacturing the curable resin composition of the present invention, examples include: using a mixer to mix the curable resin, curing agent, and polymer components, and then further mixing the thermally conductive filler and dispersant. Examples of such mixers include: homogenizers, universal mixers, Banbury mixers, kneaders, etc.

[0170] The preferred lower limit of the viscosity of the curable resin composition of the present invention at 25°C is 10 mPa·s, and the preferred upper limit is 600 mPa·s. By achieving a viscosity within this range at 25°C, the coatability of the curable resin composition of the present invention becomes excellent. A more preferred lower limit of the viscosity at 25°C is 20 mPa·s, and a more preferred upper limit is 500 mPa·s.

[0171] It should be noted that in this instruction manual, the term "viscosity" refers to the value measured using an E-type viscometer at 10 rpm. Examples of such E-type viscometers include the TPE-100 (manufactured by Toki Sangyo Co., Ltd.).

[0172] Regarding the curable resin composition of the present invention, the preferred lower limit of the shear adhesion strength of the cured product relative to aluminum is 4 MPa. By achieving a shear adhesion strength of 4 MPa or more relative to aluminum, the curable resin composition of the present invention can be suitable for use as a thermally conductive adhesive. A more preferred lower limit of the shear adhesion strength of the cured product relative to aluminum is 5 MPa.

[0173] In addition, there is no particular upper limit to the preferred upper limit of the shear adhesion strength of the cured material relative to aluminum, but the practical upper limit is 20 MPa.

[0174] It should be noted that the shear adhesion strength of the cured material relative to aluminum can be measured as follows: For the test piece, according to JIS K 6850, a Tensilon universal testing machine (A&D Corporation, "RTC-1350A") is used at 25°C and a tensile speed of 1 mm / min, and the stress at peel is calculated and measured. As the test piece, a test piece obtained as follows is used: a curable resin composition is coated with a dried thickness of approximately 100 μm and dried to remove the solvent. Then, an aluminum substrate with a thickness of 25 mm is bonded to both sides of the curable resin composition so that the width of the bonded portion is 12.5 mm. The mixture is heated at 190°C for 1 hour to obtain the test piece. For example, an A-1050P aluminum substrate can be used as the aluminum substrate.

[0175] The preferred lower limit of the temperature at which the curable resin composition of the present invention exhibits a 1% weight reduction after curing is 350°C.

[0176] By reducing the temperature by 1% of the weight after curing to 350°C or higher, the curable resin composition of the present invention is suitable for use in thermally conductive adhesives (heat-dissipating adhesives) that require particularly high heat resistance.

[0177] It should be noted that the aforementioned 1% weight loss temperature can be derived by performing thermogravimetric analysis using a thermogravimetric measuring device under heating conditions of 10°C / min from 30°C to 500°C. Examples of such thermogravimetric measuring devices include the TG / DTA6200 (manufactured by Hitachi High-Tech Science). Furthermore, the cured product used for measuring the aforementioned 1% weight loss temperature is a cured product obtained by applying a curable resin composition to a substrate PET film with a dried thickness of 100 μm, allowing it to dry, and then heating it at 190°C for 1 hour.

[0178] In addition, the cured product of the curable resin composition of the present invention is also one aspect of the present invention.

[0179] In addition, adhesives made using the curable resin composition of the present invention are also part of the present invention.

[0180] An adhesive film can be obtained by applying the adhesive of the present invention to a substrate film and then allowing it to dry. Furthermore, an adhesive film made using the adhesive of the present invention is also part of the present invention.

[0181] The adhesive of the present invention can be used as a thermally conductive adhesive (heat dissipation adhesive), and the adhesive film of the present invention can be used as a thermally conductive adhesive film (heat dissipation adhesive film).

[0182] Invention Effects

[0183] According to the present invention, a curable resin composition with excellent heat resistance, thermal conductivity, and adhesive properties can be provided. Furthermore, according to the present invention, a cured product of the curable resin composition, as well as adhesives and adhesive films made using the cured resin composition, can be provided. Detailed Implementation

[0184] The present invention will be described in more detail below with reference to specific embodiments, but the present invention is not limited to these embodiments.

[0185] (Synthesis Example 1 (Preparation of Imidine Oligomer Composition A))

[0186] 17.2 parts by weight of 1,4-bis(2-(4-aminophenyl)-2-propyl)benzene (manufactured by Mitsui Fine Chemicals, "Bisaniline P") was dissolved in 200 parts by weight of N-methylpyrrolidone (manufactured by Tokyo Chemical Industry Co., Ltd.). 52.0 parts by weight of 4,4'-(4,4'-isopropylidenediphenoxy)phthalic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to the resulting solution, and the mixture was stirred at 25°C for 2 hours to obtain an amide acid oligomer solution. After removing N-methylpyrrolidone from the obtained amide acid oligomer solution under reduced pressure, the mixture was heated at 300°C for 2 hours to obtain imide oligomer composition A (imidization rate 97%).

[0187] The obtained imide oligomer composition A was subjected to... 1 ¹H-NMR, GPC, and FT-IR analyses confirmed that the imide oligomer composition A contains an imide oligomer having the structure represented by formula (5-1) or (5-3) above (A is a 4,4'-(4,4'-isopropylidenediphenoxy)phthalic anhydride residue, and B is a 1,4-bis(2-(4-aminophenyl)-2-propyl)benzene residue). Furthermore, the number-average molecular weight of the imide oligomer composition A is 1500.

[0188] (Synthesis Example 2 (Preparation of Iimide Oligomer Composition B))

[0189] 104 parts by weight of 4,4'-(4,4'-isopropylidene diphenoxy)phthalic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) were dissolved in 300 parts by weight of N-methylpyrrolidone (manufactured by Fujifilm and Wako Pure Chemical Industries Co., Ltd., "NMP"). A solution obtained by diluting 28 parts by weight of Priamine 1074 (manufactured by Croda) as a dimeric diamine with 100 parts by weight of N-methylpyrrolidone was added to the resulting solution. The mixture was stirred at 25°C for 2 hours to obtain an amide acid oligomer solution. After removing N-methylpyrrolidone from the obtained amide acid oligomer solution under reduced pressure, the mixture was heated at 300°C for 2 hours to obtain imide oligomer composition B (imidization rate 93%).

[0190] The obtained imide oligomer composition B was subjected to... 1 ¹H-NMR, GPC, and FT-IR analyses confirmed that the imide oligomer composition B contains an imide oligomer having the structure represented by formula (5-1) or (5-3) above (A is a 4,4'-(4,4'-isopropylidenediphenoxy)phthalic anhydride residue, and B is a dimericane residue). Furthermore, the number-average molecular weight of this imide oligomer composition B is 2200.

[0191] (Synthesis Example 3 (Preparation of Iimide Oligomer Composition C))

[0192] 21.8 parts by weight of 3-aminophenol (manufactured by Tokyo Chemical Industry Co., Ltd.) were dissolved in 200 parts by weight of N-methylpyrrolidone (manufactured by Tokyo Chemical Industry Co., Ltd.). 17.2 parts by weight of 4,4'-(4,4'-isopropylidene diphenoxy)phthalic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) were added to the resulting solution, and the mixture was stirred at 25°C for 2 hours to obtain an amide acid oligomer solution. After removing N-methylpyrrolidone from the obtained amide acid oligomer solution under reduced pressure, the mixture was heated at 300°C for 2 hours to obtain an imide oligomer composition C (imidization rate 96%).

[0193] The obtained imide oligomer composition C was subjected to... 1 ¹H-NMR, GPC, and FT-IR analyses confirmed that the imide oligomer composition C contains an imide oligomer having the structure represented by formula (6-1) above (A is a 4,4'-(4,4'-isopropylidenediphenoxy)phthalic anhydride residue, and R is a hydrogen atom). Furthermore, the number-average molecular weight of the imide oligomer composition C is 700.

[0194] (Synthesis Example 4 (Preparation of Cyclohexanone Solution of Polyimide Resin))

[0195] In a reaction vessel equipped with a stirrer, a water separator, and a nitrogen inlet pipe, 54.6 parts by weight of 4,4'-(4,4'-isopropylidene diphenoxy)phthalic anhydride (manufactured by Tokyo Chemical Industry Co., Ltd.) and 150 parts by weight of cyclohexanone were added and dissolved. A mixed solution of 56.1 parts by weight of Priamine 1074 (manufactured by Croda) and 55.0 parts by weight of cyclohexanone (as a dimeric diamine) was added dropwise to the resulting solution, and an imidization reaction was carried out at 150°C for 8 hours to obtain a polyimide resin solution. It should be noted that the solid content concentration of the obtained polyimide resin solution was 45% by weight, and the number average molecular weight of the polyimide resin was 27,000.

[0196] (Examples 1-10, Comparative Examples 1-3)

[0197] According to the mixing ratios recorded in Table 1, the materials were stirred and mixed to prepare complexes 1 to 7. Next, according to the mixing ratios recorded in Table 2, the complexes and materials were stirred and mixed to prepare the curable resin compositions of Examples 1 to 10 and Comparative Examples 1 to 3.

[0198] The obtained curable resin compositions were coated onto a PET film substrate, resulting in a thickness of 100 μm after drying. The film was then dried at 100°C for 10 minutes to obtain the curable resin composition film.

[0199] (Thermal conductivity after curing)

[0200] Cured products were obtained by heating the curable resin composition films obtained in the Examples and Comparative Examples at 190°C for 1 hour. The thermal conductivity of the resulting cured products was measured at 23°C using a T3Ster DynTIM Tester (Mentor, a Siemens Business). The results are shown in Table 2.

[0201] <Evaluation>

[0202] The curable resin compositions obtained in the Examples and Comparative Examples were evaluated as follows. The results are shown in Table 2.

[0203] (Pre-curing properties of the film)

[0204] A test was conducted in which the curable resin composition film (after drying and before heat curing) obtained in the examples and comparative examples was wound around a cylinder with a diameter of 5 mm at 25°C to confirm the cracking and defects of the heat-curable adhesive film.

[0205] The condition without cracks or defects is marked as "○", the condition with partial cracks or defects is marked as "△", and the condition with cracks or defects on the entire surface of the membrane is marked as "×", for treatment evaluation.

[0206] (Shear adhesion of the cured material relative to aluminum)

[0207] Test pieces were prepared by bonding a 25mm thick aluminum substrate "A-1050P" to both sides of the curable resin composition film obtained in the Examples and Comparative Examples with the bonded portion width being 12.5mm, and heating it at 190°C for 1 hour. For the obtained test pieces, the shear bond strength of the cured material relative to aluminum (immediately after curing) was measured using a Tensilon universal testing machine (A&D Corporation, "RTC-1350A") at 25°C and a tensile speed of 1mm / min, according to JIS K6850.

[0208] In addition, after the obtained test pieces were stored at 120°C and 85%RH for 192 hours, the shear adhesion of the cured material to aluminum was measured under the same conditions as above (after storage at 120°C and 85%RH for 192 hours).

[0209] (Heat resistance: Temperature decreases by 1% by weight)

[0210] The curable resin compositions obtained in the examples and comparative examples were applied to a PET film substrate and dried to a thickness of 100 μm. The resulting cured products were then cured by heating at 190°C for 1 hour. The cured products were then measured using a thermogravimetric analyzer (Hitachi High-Tech Science, “TG / DTA6200”) at a temperature range of 30°C to 500°C and a heating rate of 10°C / min. The 1% weight loss temperature was measured.

[0211]

[0212]

[0213] Industrial availability

[0214] According to the present invention, a curable resin composition with excellent heat resistance, thermal conductivity, and adhesive properties can be provided. Furthermore, according to the present invention, a cured product of the curable resin composition, as well as adhesives and adhesive films made using the cured resin composition, can be provided.

Claims

1. A curable resin composition, characterized in that, It contains curable resin, curing agent, thermally conductive filler, polymer components, and dispersant. The curing agent contains imide oligomers. The thermally conductive filler comprises at least one selected from alumina, aluminum nitride, silicon carbide, boron nitride, magnesium oxide, zinc oxide, boron carbide, titanium carbide, zirconium oxide, aluminum, and diamond. The cured thermal conductivity of the curable resin composition is above 1 W / m·K. The molecular weight of the imide oligomer is below 4000. The polymer component is polyimide or phenoxy resin, and the number average molecular weight is 5000 or higher. The content of the imide oligomer in 100 parts by weight of the total curable resin and the curing agent is 20 parts by weight or more and 80 parts by weight or less, wherein, when the curable resin composition contains a curing accelerator, the total refers to the sum of the curable resin, the curing agent, and the curing accelerator. The content of the polymer component in 100 parts by weight of the total curable resin, the curing agent, and the polymer component is 0.5 parts by weight or more and 50 parts by weight or less. Wherein, if the curable resin composition contains a curing accelerator, the total refers to the sum of the curable resin, the curing agent, the curing accelerator, and the polymer component. In the curable resin composition excluding solvents, the thermally conductive filler is present in an amount of 50% by volume or more. The content of the dispersant in 100 parts by weight of the curable resin composition is 0.05 parts by weight or more and 4 parts by weight or less.

2. The curable resin composition according to claim 1, wherein, The curable resin and the curing agent do not contain compounds with a siloxane backbone.

3. The curable resin composition according to claim 1 or 2, wherein, The curable resin comprises at least one selected from epoxy resin, cyanate ester resin, maleimide resin and benzoxazine resin.

4. The curable resin composition according to claim 1 or 2, wherein, The imide oligomer has reactive functional groups that can react with the curable resin.

5. The curable resin composition according to claim 4, wherein, The reactive functional group is selected from at least one of acid anhydride groups, phenolic hydroxyl groups, and amino groups.

6. The curable resin composition according to claim 1 or 2, wherein it does not contain compounds having an amide backbone.

7. The curable resin composition according to claim 1 or 2, wherein, The shear bond strength of the cured material relative to aluminum is above 4 MPa.

8. The curable resin composition according to claim 1 or 2, wherein the 1% weight reduction temperature after curing is above 350°C.

9. A cured product, which is a cured product of the curable resin composition according to claim 1, 2, 3, 4, 5, 6, 7 or 8.

10. An adhesive made using the curable resin composition of claim 1, 2, 3, 4, 5, 6, 7 or 8.

11. An adhesive film formed using the cured material of claim 9 or the adhesive of claim 10.

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