Curable resin composition

Abstract

To provide a curable resin composition having excellent thermal conductivity.SOLUTION: Disclosed is a curable resin composition which contains a curable resin and a phenolic compound. The phenolic compound has a structure represented by formula (1). (In the formula, X represents a direct bond, -CH2-, -CH=CH-, -C≡C-, -C(=O)-, -C(=O)-O-, -C(=O)-NH-, -CH=N-, -CH=N-N=CH-, -N=N-, -N+(-O-)=N-, -CH=C(CH3)-, -CH=C(CN)-, -CH=CH-C(=O)-, -Ph-C(=O)-, -Ph-CH2-, -Ph-, -Ph-Ph-, -S(=O)2-, -C(=O)O-R-O-C(=O)-, -O-C(=O)-R-C(=O)-O-, -C(=O)O-Ph-O-C(=O)-, or -O-C(=O)-Ph-C(=O)-O-, Ph represents an unsubstituted or substituted aromatic ring, Y represents a linear or branched alkylene chain having 1 to 20 carbon atoms, n represents an integer of 1 to 5, and R represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms).SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a curable resin composition. [Background technology]

[0002] The amount of heat generated by electronic devices is increasing due to miniaturization and high performance, and the demand for high heat dissipation of heat dissipation resin sheets used for electronic devices is increasing. The heat dissipation resin sheet can improve its thermal conductivity by increasing the inorganic filler filling rate, but there is a problem that the flexibility decreases when the inorganic filler filling rate is increased, for example, in the B stage state before curing. If the flexibility of the heat dissipation resin sheet decreases, it is likely to have problems such as cracks occurring when the sheet is rolled up during storage or cracks occurring during the process of mounting the sheet on a substrate. Due to the above problems, there is a limit to the improvement of the thermal conductivity of the heat dissipation resin sheet by simply increasing the inorganic filler filling rate.

[0003] On the other hand, conventionally, it has been considered to increase thermal conductivity by using a matrix resin alone or by combining a matrix resin with a filler. For example, Patent Document 1 discloses an epoxy resin obtained by condensing a polyformylphenyl derivative with a phenolic compound having a specific structure, and having a weight average molecular weight of 500 to 3,000. Patent Document 2 discloses a resin composition containing an epoxy resin monomer, a novolac resin containing a compound having a specific structural unit, and a filler having a particle size within a specific range. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] International Publication No. 2015 / 060307 [Patent Document 2] JP 2013-18991 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, in conventional heat dissipation resin sheets, the effect of improving the thermal conductivity by the matrix resin alone is not sufficient, and there is a demand for further improvement in the thermal conductivity of the matrix resin.

[0006] Therefore, an object of the present invention is to provide a curable resin composition that has excellent thermal conductivity after curing. [Means for solving the problem]

[0007] As a result of extensive investigations, the present inventors have found that the above problems can be solved by using a phenol compound having a specific structure as a curing agent for a curable resin. That is, the present invention provides the following [1] to [4].

[0008] [1] A curable resin composition comprising a curable resin and a phenol compound, The curable resin composition, wherein the phenol compound has a structure represented by the following formula (1): [ka] (X is a direct bond, -CH=CH-, -C≡C-, -C(=O)-, -C(=O)-O-, -C(=O)-NH-, -CH=N-, -CH=NN=CH-, -N=N-, -N + (-O - )=N-, -CH=C(CH3)-, -CH=C(CN)-, -CH=CH-C(=O)-, -Ph-C(=O)-, -Ph-, -Ph-Ph-, -S(=O)2-, -C(=O)OR A -OC(=O)-, -OC(=O)-R A represents -C(=O)-O-, -C(=O)O-Ph-OC(=O)-, or -OC(=O)-Ph-C(=O)-O-, where Ph represents an unsubstituted or substituted aromatic ring, Y represents a linear or branched alkylene chain having 1 to 20 carbon atoms, n represents an integer of 2 to 5, and R A represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms. [2] The curable resin composition according to [1], further comprising a thermally conductive filler and an epoxy resin as a curable resin. [3] The curable resin composition according to [1] or [2], wherein the curable resin is an epoxy resin having a mesogenic skeleton. [4] A cured product of the curable resin composition according to any one of [1] to [3]. Effect of the Invention

[0009] According to the present invention, it is possible to provide a curable resin composition that has excellent thermal conductivity after curing. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, the present invention will be described with reference to embodiments. The curable resin composition of the present invention contains a curable resin and a phenol compound having a specific structure described below.

[0011] <Phenol compounds> The curable resin composition of the present invention contains a phenol compound (hereinafter, also simply referred to as "phenol compound") having a structure represented by the following formula (1). In the curable resin composition, the phenol compound serves as a curing agent that cures the curable resin described below. [ka] (X is a direct bond, -CH=CH-, -C≡C-, -C(=O)-, -C(=O)-O-, -C(=O)-NH-, -CH=N-, -CH=NN=CH-, -N=N-, -N + (-O - )=N-, -CH=C(CH3)-, -CH=C(CN)-, -CH=CH-C(=O)-, -Ph-C(=O)-, -Ph-, -Ph-Ph-, -S(=O)2-, -C(=O)OR A -OC(=O)-, -OC(=O)-R Arepresents -C(=O)-O-, -C(=O)O-Ph-OC(=O)-, or -OC(=O)-Ph-C(=O)-O-, where Ph represents an unsubstituted or substituted aromatic ring, Y represents a linear or branched alkylene chain having 1 to 20 carbon atoms, n represents an integer of 2 to 5, and R A represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms.

[0012] In the phenol compound, n may be the same or different in the aromatic rings on both sides, but from the viewpoint of improving the thermal conductivity by making the phenol compound a symmetrical structure, n in the aromatic rings on both sides is preferably the same, where n is the number of hydroxyl groups per aromatic ring. When n is 2 or more, all of the hydroxyl groups may be bonded to positions adjacent to each other, as shown in formulas (1-a) and (1-c) described later, or hydroxyl groups bonded to distant positions and hydroxyl groups bonded to adjacent positions may be mixed, as shown in formula (1-d), for example, or all of the hydroxyl groups may be bonded to positions distant from each other, as shown in formulas (1-b) and (1-e), for example, but it is preferable that at least one pair of hydroxyl groups is bonded to positions adjacent to each other.

[0013] The phenol compound preferably has a structure in which n is 2 to 3, more preferably has a structure in which n is 2, and further preferably has a structure in which n is 2 in all aromatic rings. In formula (1), examples of the substituent in Ph include a halogen atom, an alkyl group having about 1 to 8 carbon atoms, a nitrile group, and a phenyl group. In formula (1), specific examples of Ph include a substituted or unsubstituted phenylene group and a substituted or unsubstituted naphthalene group. Ph is preferably a substituted or unsubstituted phenylene group, and more preferably an unsubstituted phenylene group. In addition, the bonding position of the phenylene group is not particularly limited, but is preferably the para position.

[0014] When there are two hydroxyl groups, specifically, structures represented by the following formulae (1-a) to (1-b) are preferred. [ka] When there are three hydroxyl groups, it is preferable that the compound has a structure represented by the following formulas (1-c) to (1-e). [ka]

[0015] Furthermore, among the above-mentioned phenol compounds, those having a structure in which two hydroxyl groups are bonded to the meta and para positions, respectively, with respect to the bonding position of X, and are bonded adjacent to each other, as represented by the above formula (1-a), are preferred.

[0016] In the curable resin composition, when the phenol compound reacts with the curable resin, the hydroxyl group in the phenol compound becomes the reaction point with the curable resin, but as described above, since the hydroxyl groups are bonded so as to be adjacent to each other, the molecules of the curable resin after the reaction become close to each other, so-called stacking occurs. This improves the molecular alignment of the curable resin, and makes it easier to impart excellent thermal conductivity to the cured product of the curable resin composition.

[0017] In the formulae (1) and (1-a) to (1-e), X can improve the planarity of the phenol compound. By improving the planarity of the phenol compound, when the curable resin reacts with the phenol compound, the molecular alignment of the curable resin is improved, and the thermal conductivity of the cured product of the curable resin composition can be improved. X is a direct bond, -C(=O)-, -C(=O)-O-, -C(=O)-NH-, -Ph-C(=O)-, -Ph-, -Ph-Ph-, -C(=O)OR A -OC(=O)-, -OC(=O)-R A At least one selected from -C(=O)-O-, -C(=O)O-Ph-OC(=O)-, and -OC(=O)-Ph-C(=O)-O- is preferred, at least one selected from a direct bond, -C(=O)-, and -Ph-C(=O) is more preferred, and a direct bond or -C(=O)- is even more preferred. Each of the two bonds of each X may be bonded to either Y or an aromatic ring having a hydroxyl group. When X has Ph, it is preferable that Ph of X is bonded to an aromatic ring having a hydroxyl group from the viewpoint of improving planarity.

[0018] In addition, in formulas (1), (1-a) to (1-e), the two Xs may be the same group or different groups, but are preferably the same group. When the two Xs are the same group, it is more preferable that the phenol compound is symmetrical with respect to Y, from the viewpoint of easily improving the thermal conductivity of the cured product of the curable resin composition. Here, being symmetrical means that the structures consisting of a pair of Xs and an aromatic ring having a hydroxyl group with Y at the center are all the same.

[0019] In the formulae (1) and (1-a) to (1-e), Y can improve the mobility and flexibility of the phenol compound. By improving the mobility and flexibility of the phenol compound, the reaction proceeds while the curable resin and the phenol compound are aligned, so that the molecular alignment in the cured product after the reaction is good, and excellent thermal conductivity can be imparted to the cured product of the curable resin composition. Specific examples of Y, in the case of a straight chain, include a methylene group, an ethylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group, a nonamethylene group, a decamethylene group, an undecamethylene group, a dodecamethylene group, a tridecamethylene group, a tetradecamethylene group, a pentadecamethylene group, etc. In the case of a branched alkylene chain, a propylene group, a sec-butylene group, a tert-butylene group, an iso-butylene group, an iso-pentylene group, a tert-pentylene group, a 2-hexylene group, a 3-hexylene group, a 2-heptylene group, a 3-heptylene group, an iso-heptylene group, a tert-heptylene group, an iso-octylene group, a tert-octylene group, a 2-ethylhexylene group, etc. Y is preferably a linear or branched alkylene chain having 2 to 15 carbon atoms, more preferably a linear or branched alkylene chain having 3 to 10 carbon atoms, and even more preferably a linear or branched alkylene chain having 4 to 9 carbon atoms. Moreover, Y is even more preferably a linear chain, from the viewpoint of ensuring the rotatability of Y and thus easily improving the mobility and flexibility of the phenol compound.

[0020] The phenol compound is preferably one represented by the following formulae (1-f) to (1-j), more preferably one represented by the following formulae (1-f) to (1-i). Also, one represented by (1-g) or (1-h) is even more preferable. (1-g) or (1-h) has a straight-chain aliphatic skeleton between two aromatic rings, and has a lower melting point and better solvent solubility than compounds such as (1-f), (1-i), and (1-j) that have a carbonyl group, and is therefore easier to handle. [ka] In the above formulas (1-f) to (1-j), p is an integer of 1 to 20, preferably an integer of 2 to 15, more preferably an integer of 3 to 12, and even more preferably an integer of 4 to 10. Also, q is an integer of 0 to 18, preferably an integer of 0 to 13, more preferably an integer of 1 to 10, and even more preferably an integer of 2 to 8.

[0021] (Method of producing phenolic compounds) The phenol compound can be obtained by coupling a compound having a basic skeleton of XYX (X and Y are as described above) like the compound shown in the following formula (2), or a compound having a structure that is a precursor of the basic skeleton of XYX, with a compound shown in the following formula (3) or a derivative thereof by a Friedel-Crafts reaction, a cross-coupling reaction, or the like. When the phenol compound is obtained through a Friedel-Crafts reaction, a cross-coupling reaction, or the like, it may be obtained through another reaction in addition to the Friedel-Crafts reaction or the cross-coupling reaction.

[0022] [ka] In formula (2), M represents a halogen atom, and X and Y are as described above, but in order to perform the Friedel-Crafts reaction appropriately, it is preferable that X has a structure in which it is bonded to an acyl group or a saturated hydrocarbon group, such as a direct bond, -C(=O)-, -C(=O)-NH-, -CH=CH-C(=O)-, -Ph-C(=O)-, etc., and from the viewpoint of reactivity, it is more preferable that X is -C(=O)- among the above. Furthermore, M is preferably a chlorine atom or a bromine atom, and more preferably a chlorine atom.

[0023] [ka] In the formula (3), n is as described above. B is a protective group for a hydroxyl group, preferably an alkyl group having 1 to 4 carbon atoms, and more preferably a methyl group.

[0024] Specific examples of the compound represented by formula (2) include adipoyl chloride, azelayl chloride, dodecandioyl dichloride, suberyl dichloride, sebacoyl chloride, etc. Among these, adipoyl chloride or sebacoyl chloride is preferred, and adipoyl chloride is more preferred.

[0025] Specific examples of the compound represented by formula (3) include anisole, 1,2-dimethoxybenzene, 1,3-dimethoxybenzene, 1,4-dimethoxybenzene, 1,2,3-trimethoxybenzene, 1,2,4-trimethoxybenzene, 1,3,5-trimethoxybenzene, tetramethoxybenzene, pentamethoxybenzene, etc. Among these, 1,2-dimethoxybenzene is preferred.

[0026] In the method using the Friedel-Crafts reaction, when X has an acyl group and M is bonded to the acyl group, a reduction reaction to convert the acyl group to a methylene group may be performed after the Friedel-Crafts reaction. Examples of the reduction reaction include the Wolff-Kischner reduction reaction using hydrazine and the reduction reaction using a palladium carbon catalyst. By performing the reduction reaction, a phenol compound can be easily obtained even when X is a direct bond. In addition, when a Friedel-Crafts reaction is performed, the protecting group R B In the case where the Friedel-Crafts reaction or the reduction reaction described above is carried out, the deprotection reaction is preferably carried out after the reduction reaction.

[0027] The melting point of the phenol compound is preferably 0°C or higher and 300°C or lower, more preferably 10°C or higher and 250°C or lower, and even more preferably 20°C or higher and 200°C or lower. When the melting point of the phenol compound is higher than the lower limit, the phenol compound is easily oriented during the heat curing process, and a cured product with excellent thermal conductivity is obtained. When the melting point of the phenol compound is lower than the upper limit, the phenol compound is excellent in solvent solubility and easy to handle. The melting point of the phenol compound may be measured as the endothermic peak temperature when the temperature is increased at 5° C. / min using a differential scanning calorimeter. The detailed measurement method is as described in the Examples.

[0028] The curable resin composition of the present invention may contain a curing agent other than the above-mentioned phenolic compound, so long as the effect of the present invention is not significantly impaired. The curing agent other than the above-mentioned phenolic compound is a compound capable of reacting with the curable resin described below to cure the curable resin. The content of the curing agent other than the phenol compound in the curable resin composition is, for example, less than 50 equivalent %, preferably 30 equivalent % or less, more preferably 10 equivalent % or less, assuming that the total amount of the phenol compounds contained in the curable resin composition is 100 equivalent %. The curable resin composition of the present invention may not contain a curing agent other than the phenol compound.

[0029] <Curing resin> The curable resin composition of the present invention contains a curable resin. The curable resin is preferably a thermosetting resin. As the curable resin, it is preferable to use a resin capable of reacting with the above-mentioned phenol compound. Examples of the thermosetting resin that can react with a phenol compound include a thermosetting urethane resin, an epoxy resin, a benzoxazine resin, and a bismaleimide resin. Among these, at least one selected from the group consisting of an epoxy resin, a benzoxazine resin, and a bismaleimide resin is preferred, and an epoxy resin is more preferred.

[0030] The epoxy resin may be, for example, a compound containing two or more epoxy groups in the molecule, and may have a weight average molecular weight of, for example, less than 10,000, preferably 5,000 or less. Specific examples of the epoxy resin include styrene skeleton-containing epoxy resins, resorcinol type epoxy resins, bisphenol A type epoxy resins, bisphenol F type epoxy resins, bisphenol E type epoxy resins, bisphenol S type epoxy resins, 2,2'-diallyl bisphenol A type epoxy resins, hydrogenated bisphenol type epoxy resins, propylene oxide-added bisphenol A type epoxy resins, phenol novolac type epoxy resins, cresol novolac type epoxy resins, biphenol type epoxy resins, phenoxy type epoxy resins, naphthalene type epoxy resins, biphenyl type epoxy resins, phenylene ether type epoxy resins, fluorene type epoxy resins, phenol aralkyl type epoxy resins, naphthol aralkyl type epoxy resins, naphthylene ether type epoxy resins, dicyclopentadiene type epoxy resins, anthracene type epoxy resins, epoxy resins having a mesogen skeleton, epoxy resins having an adamantane skeleton, epoxy resins having a tricyclodecane skeleton, and epoxy resins having a triazine nucleus in the skeleton, glycidylamine type epoxy resins, and glycidyl ester type epoxy resins.

[0031] When an epoxy resin is used as the curable resin, the epoxy resin may be contained in the curable resin composition so that the equivalent ratio of the hydroxyl group contained in the phenol compound to the epoxy group contained in the epoxy resin (hydroxyl group / epoxy group) is, for example, 0.5 or more and 2 or less. The above equivalent ratio is preferably 0.6 or more / 1.8 or less, more preferably 0.7 or more and 1.6 or less, and even more preferably 0.8 or more / 1.4 or less. By setting the equivalent ratio to a value close to 1, the curable resin and the phenol compound can be appropriately reacted to obtain a good cured product.

[0032] The epoxy resin used in the present invention is preferably an epoxy resin having a mesogenic skeleton. The mesogenic skeleton is a molecular structure capable of expressing liquid crystallinity, and improves the alignment after curing, which makes it easier to impart excellent thermal conductivity to the cured product of the curable resin composition. The epoxy resin having a mesogenic skeleton preferably has two or more epoxy groups in one molecule, and the number of epoxy groups in one molecule is more preferably 2 to 4, and further preferably 2. The number of epoxy groups being 2 makes it easier to improve the alignment after curing, which makes it easier to improve thermal conductivity.

[0033] An example of a structure having a mesogenic skeleton is the structure of the following formula (4). [ka] In the formula (4), each * is independently a bond to a group containing an epoxy group or a bond to a linking group bonded to another mesogenic skeleton. Each k is an integer of 0 to 4, and each β is independently -R, -OR, a halogen atom, -CN, -NO2, or -COCH3. Each R is an aliphatic hydrocarbon group having 1 to 8 carbon atoms. Each α is at least one selected from the group represented by the formula (A) shown below.

[0034] [ka] In group (A), n is an integer from 0 to 4, s is an integer from 0 to 7, m is an integer from 0 to 8, l is an integer from 0 to 12, and r is an integer from 0 to 8. β is as described above.

[0035] In formula (4), the bonding position indicated by * is preferably the para position relative to the α position, that is, the structure shown in formula (4) is preferably the following formula (4-1). [ka] In formula (4-1), *, α, β, and k are as defined above.

[0036] In formulas (4) and (4-1), β is preferably a halogen atom or an alkyl group, more preferably an alkyl group. The halogen atom is any one of a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. The alkyl group may be linear or may have a branched or cyclic structure, but is preferably linear. Specific examples of the alkyl group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, an n-pentyl group, an n-hexyl group, and an n-octyl group, and of these, a methyl group is preferred. k is preferably an integer of 0 to 2. n is preferably an integer of 0 to 2. s is preferably an integer of 0 to 5, and more preferably an integer of 0 to 2. m is preferably an integer of 0 to 4, and more preferably an integer of 0 to 2. l is preferably an integer of 0 to 6, and more preferably an integer of 0 to 3. r is preferably an integer of 0 to 4, and more preferably an integer of 0 to 2, and most preferably an integer of 0.

[0037] In the formula (4) or formula (4-1), the mesogenic skeleton is preferably one in which α is a single bond or a group containing -COO-. Among these, a biphenyl skeleton in which α is a single bond, a phenylbenzoate skeleton in which α is a group containing -COO-, or a skeleton represented by the following formula (X) is more preferable. [ka] In the formula (X), β, k, n, and * are as defined above, but each * is preferably a bond to a group containing an epoxy group.

[0038] In formulae (4), (4-1) and (X), the group containing an epoxy group bonded to * is preferably an organic group containing an epoxy group having about 2 to 20 carbon atoms, more preferably an organic group containing an epoxy group having 3 to 12 carbon atoms, and among these, a group represented by the following formula (5) is even more preferable. When the group containing an epoxy group is a group represented by the following formula (5), synthesis of an epoxy resin having a mesogenic skeleton becomes easy.

[0039] [ka] In formula (5), * is a bond bonded to the aromatic ring of the mesogenic skeleton. 1 represents a straight or branched alkylene group having 1 to 10 carbon atoms. Examples of the straight or branched alkylene group include a methylene group, a methylmethylene group, a dimethylmethylene group, an ethylene group, a propylene group, a trimethylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group, a nonamethylene group, a decamethylene group, etc. Among these, a methylene group, an ethylene group, a trimethylene group, or a tetramethylene group is preferable.

[0040] In addition, it is preferable that in the above formulas (4) and (4-1), each of the *'s in the epoxy resin having a mesogenic skeleton is bonded to a group represented by formula (5). Therefore, the epoxy resin having a mesogenic skeleton preferably has a structure represented by the following formula (4-2). [ka] In addition, in formula (4-2), R 1 , α, β, and k are as described above.

[0041] In the above formulas (4) and (4-1), the linking group bonded to * may be an organic group having about 1 to 24 carbon atoms, preferably an organic group having 3 to 16 carbon atoms, and more preferably an organic group having 4 to 12 carbon atoms. In the above formulas (4) and (4-1), when at least one of the *'s is bonded to a linking group that is linked to another mesogenic skeleton, the epoxy resin having a mesogenic skeleton will have multiple mesogenic skeletons in one molecule, and in this case, it is preferable that there are two mesogenic skeletons in one molecule. In the above formulas (4) and (4-1), the "another mesogenic skeleton" may be any of the skeletons represented by formulas (4) and (4-1), respectively. The two or more mesogenic skeletons in one molecule may be the same or different from each other, but are preferably the same from the viewpoint of ease of production.

[0042] In the above formulas (4) and (4-1), it is also preferred that one of the *'s is bonded to a group containing an epoxy group, and the other * is bonded to a linking group that is linked to another mesogenic skeleton. In this case, the group containing an epoxy group is as described above, and is preferably a group represented by formula (5). Therefore, it is also preferred that the epoxy resin having a mesogenic skeleton has a structure represented by the following formula (4-3). The structure represented by the following formula (4-3) is a structure represented by R 2 By having a linking group represented by the following formula, the thermal conductivity is likely to be improved.

[0043] [ka] In formula (4-3), α, β, k, and R 1 is as stated above. R 2 is a divalent organic group, R 2 The number of carbon atoms is, for example, 1 to 24, preferably 2 to 16, and more preferably 3 to 12. R 2 More specifically, is a hydrocarbon group which may have a heteroatom such as an oxygen atom, a nitrogen atom, a sulfur atom, etc. As the heteroatom, an oxygen atom is preferred, and among these, an oxygen atom constituting an ether bond is preferred. In addition, in formula (4-3), R 2 From the viewpoint of ease of synthesis, *-OR 4 It is preferable that the group is represented by -O-*, where * is a bond to the phenyl ring, and R 4 R is an aliphatic hydrocarbon group having 1 to 24 carbon atoms, and is preferably a saturated aliphatic hydrocarbon group. 4 R may be linear, branched or cyclic, but is preferably linear. 4 has, for example, 1 to 24 carbon atoms, preferably 2 to 16 carbon atoms, more preferably 3 to 12 carbon atoms, and further preferably 6 to 12 carbon atoms. R 4 R is preferably a linear or branched alkylene group. 4 Specific examples of the alkyl group include an ethylene group, a propylene group, a tetramethylene group, a pentamethylene group, a hexamethylene group, a heptamethylene group, an octamethylene group, a nonamethylene group, a decamethylene group, an undecamethylene group, a dodecamethylene group, a tridecamethylene group, a tetradecamethylene group, a pentadecamethylene group, a hexadecamethylene group, and a heptadecamethylene group. Of these, an octamethylene group is particularly preferred.

[0044] The epoxy resin having a mesogenic skeleton is also preferably a compound represented by the following formula (5-1), (5-2), or (5-3). Among these, the compound represented by formula (5-1) is preferred from the viewpoint of ease of production of the epoxy resin, and the compound represented by formula (5-3) is preferred from the viewpoint of improving thermal conductivity. [ka] In addition, in formula (5-1), R 6 are each independently an alkyl group or a hydrogen atom. The alkyl group is as defined above, and is preferably a methyl group. In addition, in formula (5-1), R 3 is an alkylene group having 1 to 10 carbon atoms, preferably an alkylene group having 1 to 5 carbon atoms, and more preferably at least one selected from a methylene group and an ethylene group.

[0045] [ka] In addition, in formula (5-2), R 3 and R 4 is as stated above.

[0046] [ka] In addition, in formula (5-3), R 5 is preferably an alkylene group having 1 to 15 carbon atoms, more preferably an alkylene group having 2 to 10 carbon atoms, and even more preferably an alkylene group having 3 to 5 carbon atoms.

[0047] In addition, as the epoxy resin having a mesogenic skeleton, for example, compounds described in the non-patent document Macromol. Chem. Phys. 1998, 199, 853. and the patent documents Japanese Patent No. 4118691, Japanese Patent No. 5397476, Japanese Patent No. 547195, and Japanese Patent No. 7024777 are also preferred.

[0048] The epoxy resin having a mesogenic skeleton may be in a prepolymer state obtained by reacting a part of it with a curing agent, etc. The curing agent may be the above-mentioned phenol compound, but is not limited to the phenol compound, and may be any of an amine-based curing agent, an acid anhydride-based curing agent, a mercaptan-based curing agent, an imidazole-based curing agent, etc.

[0049] The weight average molecular weight of the epoxy resin having a mesogenic skeleton is preferably less than 10,000, more preferably not more than 5,000, and even more preferably not more than 3,000. The weight average molecular weight of the epoxy resin having a mesogenic skeleton is not particularly limited, but may be, for example, 200 or more, and preferably 250 or more. The weight average molecular weight is a weight average molecular weight measured by gel permeation chromatography (GPC) in terms of polystyrene. In the gel permeation chromatography (GPC) measurement, tetrahydrofuran is preferably used as an eluent. However, when the molecular weight is a low molecular weight of 1000 or less, the weight average molecular weight may be calculated from the structural formula. In the curable resin composition, the epoxy resin may react by curing, but the weight average molecular weight means the weight average molecular weight of the epoxy resin in the state before curing.

[0050] The epoxy equivalent of the epoxy resin having a mesogenic skeleton is not particularly limited, but is, for example, 100 g / eq or more and 1000 g / eq or less. The epoxy equivalent of the epoxy resin is preferably 120 g / eq or more, more preferably 140 g / eq or more, and is preferably 500 g / eq or less, more preferably 400 g / eq or less. The epoxy equivalent can be measured, for example, according to the method specified in JIS K 7236.

[0051] In the curable resin composition, the content of the epoxy resin having a mesogenic skeleton is preferably 30 mass % or more, more preferably 40 mass % or more, and even more preferably 50 mass % or more, based on the total amount of the resin components constituting the curable resin composition. The mesogenic skeleton-containing epoxy resin may be used alone or in combination of two or more kinds.

[0052] When the curable resin composition contains an epoxy resin having a mesogenic skeleton, it may further contain an epoxy resin not having a mesogenic skeleton and a curable resin other than the epoxy resin (hereinafter, collectively referred to as "other resins"). The epoxy resin not having a mesogenic skeleton may have one or more epoxy groups, preferably two or more. From the viewpoint of thermal conductivity, the content of the other resin in the curable resin composition is preferably smaller, and is, for example, less than 100 parts by mass, preferably 50 parts by mass or less, more preferably 30 parts by mass or less, and further preferably 15 parts by mass or less, relative to 100 parts by mass of the epoxy resin having a mesogenic skeleton. The smaller the content of the other resin, the better.

[0053] <Filler> The curable resin composition of the present invention may contain a filler. The filler is preferably an inorganic filler having thermal conductivity. By containing the filler, the curable resin composition is more likely to have high thermal conductivity of the cured product of the curable resin composition. The filler may be dispersed in a matrix component formed by the reaction of the curable resin with a phenolic compound.

[0054] From the viewpoint of increasing the thermal conductivity of the curable resin composition, the thermal conductivity of the filler is, for example, 10 W / (m·K) or more, preferably 15 W / (m·K) or more, and more preferably 20 W / (m·K) or more. The thermal conductivity of the filler is not particularly limited, but may be, for example, 2000 W / (m·K) or less, or 1000 W / (m·K) or less. The thermal conductivity of the filler can be measured, for example, by a periodic heating thermoreflectance method using a thermal microscope manufactured by Bethel Corporation on a cross section of the filler cut with a cross section polisher.

[0055] The filler may also have electrical insulation properties, and the electrical resistivity may be, for example, 10 8 It is preferable that the filler has a dielectric constant of 0.1 to 1.0 [Ω·m] or more. If the filler has high electrical insulation, it can be suitably used for electronic devices such as substrates. Therefore, it is preferable that the filler is a thermally conductive filler having electrical insulation properties.

[0056] Examples of the filler include metals, metal oxides, metal nitrides, metal hydroxides, carbon materials, oxides other than metals, nitrides, and carbides. The shape of the filler may be any shape such as scale-like, spherical, crushed, irregular, polyhedral, or fibrous, or may be an aggregated particle formed by aggregation of primary particles. For example, boron nitride, which will be described later, is preferably used as an aggregated particle. In the filler, examples of metals include aluminum, copper, nickel, etc., examples of metal oxides include aluminum oxide, magnesium oxide, zinc oxide, etc., such as alumina, and examples of metal nitrides include aluminum nitride. Examples of metal hydroxides include aluminum hydroxide. Further, examples of carbon materials include spherical graphite, scaly graphite, and carbon fibers. Examples of oxides, nitrides, and carbides other than metals include quartz, boron nitride, and silicon carbide. Among these, from the viewpoint of ensuring electrical insulation, at least one selected from metal oxides, metal nitrides, metal hydroxides, oxides other than metals, nitrides, and carbides is preferred, and at least one selected from metal oxides, metal hydroxides, and nitrides is more preferred. Specifically, at least one selected from aluminum oxide, aluminum hydroxide, and boron nitride is even more preferred. The fillers may be used alone or in combination of two or more of the above.

[0057] The average particle size of the filler is preferably 0.1 μm or more and 200 μm or less, more preferably 0.5 μm or more and 150 μm or less, and even more preferably 1 μm or more and 110 μm or less. It is also preferable to use, for example, a small particle size filler having an average particle size of 0.1 μm or more and 5 μm or less in combination with a large particle size filler having an average particle size of more than 5 μm and 200 μm or less in combination with the filler. By using fillers with different average particle sizes, the filling rate of the filler in the curable resin composition can be increased. The average particle size of the filler can be measured by observation using an electron microscope, etc. More specifically, for example, the particle sizes of 50 random thermally conductive fillers can be measured using an electron microscope or an optical microscope, and the average value (arithmetic mean value) can be regarded as the average particle size. When the filler is, for example, an agglomerated particle as described above, the average particle size of the agglomerated particles may be within the above range.

[0058] The filler content is not particularly limited, but from the viewpoint of improving heat dissipation properties, it is, for example, 30 mass % or more, preferably 50 mass % or more, more preferably 70 mass % or more, and even more preferably 80 mass % or more in the curable resin composition. The filler content is not particularly limited, but in order to contain a certain amount or more of curable resin or phenol compound, it is sufficient that the filler content is 98% by mass or less, preferably 96% by mass or less, more preferably 95% by mass or less, and even more preferably 93% by mass or less.

[0059] (Cure accelerator) The curable resin composition of the present invention may contain a curing accelerator. By containing a curing accelerator, the curability of the curable resin composition can be increased. The curing accelerator is not particularly limited, and examples thereof include imidazole-based curing accelerators and tertiary amine-based curing accelerators. Among them, it is preferable to use an imidazole-based curing accelerator. Examples of the imidazole-based curing accelerator include 1-cyanoethyl-2-phenylimidazole in which the 1-position of imidazole is protected with a cyanoethyl group, and an imidazole-based curing accelerator in which basicity is protected with isocyanuric acid. Examples of commercially available products include 2MA-OK, 2MZ, 2MZ-P, 2PZ, 2PZ-PW, 2P4MZ, C11Z-CNS, 2PZ-CN, 2PZ-CNS, 2PZCNS-PW, 2MZ-A, 2MZA-PW, C11Z-A, 2E4MZ-A, 2MAOK-PW, 2PZ-OK, 2MZ-OK, 2PHZ, 2PHZ-PW, 2P4MHZ, 2P4MHZ-PW, 2E4MZ·BIS, VT, VT-OK, MAVT, and MAVT-OK (all manufactured by Shikoku Chemical Industry Co., Ltd.). Examples of the organic phosphine compound include triphenylphosphine, tetraphenylphosphonium tetra-p-tolylborate, tetraphenylphosphonium tetraphenylborate, tri-tert-butylphosphonium tetraphenylborate, (4-methylphenyl)triphenylphosphonium thiocyanate, tetraphenylphosphonium thiocyanate, butyltriphenylphosphonium thiocyanate, triphenylphosphine triphenylborane, etc. Specific examples of the organic phosphine compound include TPP, TPP-MK, TPP-K, TTBuP-K, TPP-SCN, TPP-S (all manufactured by Hokko Chemical Industry Co., Ltd.), etc. These curing accelerators may be used alone or in combination of two or more. The content of the curing accelerator is, for example, 0.1 parts by mass or more and 10 parts by mass or less, preferably 0.2 parts by mass or more and 5 parts by mass or less, and more preferably 0.5 parts by mass or more and 3 parts by mass or less, relative to 100 parts by mass of the total amount of the curable resin and the phenol compound.

[0060] (Coupling Agent) The curable resin composition of the present invention may contain a coupling agent. Examples of the coupling agent include a silane coupling agent and a titanium coupling agent, and the silane coupling agent is preferred. As the silane coupling agent, known ones can be used without any particular limitation, and examples thereof include dimethyldimethoxysilane, 3-acryloxypropyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, vinyltrimethoxysilane, n-decyltrimethoxysilane, 3-isocyanatopropyltriethoxysilane, 3-(2-aminoethyl)aminopropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane, glycidoxypropyltrimethoxysilane, and N-phenyl-3-aminopropyltrimethoxysilane. The silane coupling agent may be used alone or in combination of two or more kinds. When the curable resin composition contains a filler, the curable resin composition contains a silane coupling agent, which makes it easier to disperse the filler. As a result, the filler can be highly loaded, and the thermal conductivity is increased. The content of the coupling agent in the curable resin composition is, for example, 0.1 mass % or more and 10 mass % or less, preferably 0.3 mass % or more and 5 mass % or less, and more preferably 0.5 mass % or more and 3 mass % or less, based on the total amount of the curable resin composition.

[0061] [Other ingredients] In addition to the above components, the curable resin composition of the present invention may contain other additives such as a flame retardant, an antioxidant, a tackifier, a plasticizer, a thixotropy imparting agent, and a colorant. A solvent may be added to the curable resin composition in its production method, and it is preferable that the added solvent partly remains in the curable resin composition.

[0062] As described in the production method described later, the curable resin composition of the present invention contains a curable resin and a phenolic compound, and may be uncured or semi-cured and in a B-stage state. When the curable resin composition is in an uncured or B-stage state, it has high adhesion to another member and can be adhered to another member with high adhesive strength.

[0063] [Thermal Conductivity] The thermal conductivity of the matrix component when the mixture of the curable resin and the phenolic compound contained in the thermally conductive composition is cured is preferably 0.17 W / (m·K) or more. When the thermal conductivity of the cured product is 0.17 W / (m·K) or more, the heat dissipation is good. From the viewpoint of heat dissipation, the thermal conductivity is more preferably 0.22 W / (m·K) or more, and even more preferably 0.30 W / (m·K) or more. The upper limit of the thermal conductivity of the matrix component is not particularly limited, but in practice it is, for example, about 1 W / (m·K). The thermal conductivity can be determined by measuring the thermal conductivity of a cured product obtained by mixing a curable resin and a phenolic compound in the ratio contained in the thermal conductive composition, and curing the mixture as described in the examples described below.

[0064] (Method for producing curable resin composition) The curable resin composition can be obtained by mixing a curable resin and a phenolic compound, and optionally a curing agent other than the phenolic compound, a filler, a curing accelerator, a coupling agent, and other additives other than these. The curable resin composition may be diluted with a dilution solvent such as an organic solvent by adding the dilution solvent.

[0065] (Method of using the curable resin composition) The curable resin composition may be cured and used as a cured product. The curable resin composition may be used for various purposes, for example, for heat dissipation members. The heat dissipation members may be used, for example, in electronic devices. The curable resin composition of the present invention has a high thermal conductivity of the matrix component after curing, so that high heat dissipation can be ensured when used inside an electronic device. More specifically, the heat dissipation member is disposed on an electronic component and used to dissipate heat generated by the electronic component. In addition, the heat dissipation member of the present invention is preferably disposed so as to fill the gap between two opposing members and used. The two opposing members may be, for example, an electronic component on one side and a heat conductor such as a heat sink for dissipating heat from the electronic component on the other side, a housing for an electronic device, a substrate, or the like.

[0066] The electronic component in which the curable resin composition is used is not particularly limited, but is preferably a semiconductor device, and more preferably a power module that requires high heat dissipation. The power module is used, for example, in an inverter. The power module is used, for example, in industrial equipment such as elevators and uninterruptible power supplies (UPS), but its use is not particularly limited. The curable resin composition may also be used as a part of a circuit board, or as a sealant for electronic components for embedding electronic components such as semiconductor chips inside.

[0067] The curable resin composition may be used in any form. It may be formed into a predetermined shape such as a thin film, a sheet, or a block by coating, casting, potting, extrusion molding, or the like, and then cured, or it may be formed into an indefinite shape and then cured. The curable resin composition may be applied or laminated on a support such as a release sheet, metal foil, or substrate, and dried by heating or the like as necessary to form a sheet, which may then be placed on an electronic component formed into a sheet. In this case, the curable resin composition may be cured after being placed on the electronic component, or may be cured before being placed on the electronic component. The curable resin composition may be applied onto an electronic component or a thermal conductor by coating, casting, potting or the like, and then cured to be used as a heat dissipation member.

[0068] The heating temperature when curing the curable resin composition is not particularly limited, and may be, for example, in the range of 70° C. to 240° C., preferably 120° C. to 220° C., and more preferably 160° C. to 210° C., and the heating time may be, for example, 0.5 hours to 24 hours, preferably 1 hour to 18 hours, and more preferably 2 hours to 12 hours. When heating for curing, appropriate pressure may be applied, and for example, the composition may be heated and cured under a pressurized or negative pressure, which makes it easier to adhere to other members with high adhesive strength when cured. EXAMPLES

[0069] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples in any way.

[0070] The methods for measuring and evaluating each physical property are as follows.

[0071] [Thermal Conductivity] For the cured resin products obtained in each of the Examples and Comparative Examples, the thermal conductivity in the thickness direction was measured using a thermal diffusivity measuring device ("ai-Phase Mobile M3" manufactured by Ai-Phase Corporation).

[0072] [Melting point] The melting points of the curing agents obtained in the following Synthesis Examples 2 to 5 were measured using a DSC (differential scanning calorimeter) as the endothermic peak temperature when the temperature was raised at 5° C. / min. The differential scanning calorimeter used was an EXSTAR DSC7020 (manufactured by SSI NanoTechnology Inc.).

[0073] The components used in the examples and comparative examples are as follows. (Epoxy) Mesogen: Epoxy resin with a mesogen skeleton of the following structure, molecular weight 622 [ka] Biphenyl: "YL6121HA", manufactured by Mitsubishi Chemical Corporation, an epoxy resin having a mesogen skeleton with the following structure, molecular weight 326 [ka] Bisphenol A: Epoxy resin represented by the following structure, "YD-127", manufactured by Nippon Steel Chemical Co., Ltd., bisphenol A type epoxy resin [ka]

[0074] Among the above epoxies, the mesogen was obtained according to Synthesis Example 1 below. [Synthesis Example 1] (Step 1) 10.0g (100mmol) of 5-hexen-1-ol and 24.5g (240mmol) of triethylamine were added to a 200mL eggplant flask, stirred in an ice bath, and cooled to 0°C to obtain solution A. A solution in which 24.8g (130mmol) of p-toluenesulfonyl chloride was dissolved in 81mL of dichloromethane was dropped into solution A and stirred for 18 hours to obtain reaction solution B. Reaction solution B was filtered by suction, 100mL of water was added to the filtrate, and the mixture was stirred, and then the organic layer was extracted with diethyl ether. The organic layer was washed with 1mol / L hydrochloric acid, saturated saline, saturated sodium bicarbonate water, and saturated saline in that order, and dried with magnesium sulfate. Thereafter, the solvent was distilled off from the solution under reduced pressure to obtain 22.3g of Hex-5-en-1-yl4-methylbenzenesulfonate. The yield at this time was 88%. In addition, the obtained compound was 1 H-NMR (400MHz, CDCl3), 13 The structure was confirmed by C-NMR (400 MHz, CDCl3) and IR (KBr, ν). The reaction scheme for step 1 is as follows: [ka]

[0075] The peaks detected during structure confirmation are as follows: 1 H-NMR(400MHz,CDCl3,δ,ppm):1.41(quin,J=7.3Hz,2H,-CHCH2CH2-),1.66(quin,J=6.4Hz,2H,-CH2CH2O-),2.00(q,J=7.3Hz,2H,CH2CHCH2-),2.4 5(s,3H,CH3),4.03(t,J=6.4Hz,3H,-CH2O-),4.93-4.99(m,2H,CH2CH-),5.67-5.77(m,1H,CH),7.35(d,J=8.2Hz,2H,Ar),7.79(d,J=8.2Hz,2H,Ar) 13C-NMR(400MHz,CDCl3,δ,ppm):21.45,24.4,28.0,32.8,70.3,114.9,127.7,132.9,137.8,144.6 IR(KBr,ν):1188,1359,1456,1496,1599,2936

[0076] (Step 2) In a 200 mL eggplant flask, 12.7 g (50.0 mmol) of hex-5-en-1-yl 4-methylbenzenesulfonate obtained in step 1, 9.13 g (60.0 mmol) of methyl 4-hydroxybenzoate, 9.68 g (70.0 mmol) of potassium carbonate, a catalytic amount of potassium iodide, and 125 mL of acetone were added to obtain solution C. The solution C was stirred at 70° C. for 48 hours. The stirred solution C was filtered and the solvent was distilled off under reduced pressure. 100 mL of water was added to the obtained solution and stirred, and then the organic layer was extracted with dichloromethane. The organic layer was washed with 1 mol / L aqueous sodium hydroxide solution and saturated saline in that order, dried over magnesium sulfate, and then the solvent was distilled off under reduced pressure to obtain 11.0 g of methyl 4-(hex-5-en-1-yloxy)benzoate. The yield at this time was 94%. In addition, the obtained compound was 1 H-NMR (400MHz, CDCl3), 13 The structure was confirmed by C-NMR (400 MHz, CDCl3) and IR (KBr, ν). The reaction scheme for step 2 is as follows: [ka]

[0077] The peaks detected during structure confirmation are as follows: 1H-NMR(400MHz,CDCl3,δ,ppm):1.54-1.62(m,2H,-CHCH2CH2-),1.82(quin,J=6.4Hz,2H,-CH2CH2O-),2.14(q,J=7.3Hz,2H,CH2CHCH2-),3.88(s ,3H,CH3),4.01(t,J=6.4Hz,2H,-CH2O-),4.97-5.07(m,2H,CH2CH-),5.78-5.88(m,1H,CH),6.90(d,J=9.2Hz,2H,Ar),7.98(d,J=8.7Hz,2H,Ar) 13 C-NMR(400MHz,CDCl3,δ,ppm):25.2,28.5,33.3,51.8,67.9,114.0,114.8,122.3,127.0,131.5,138.3,162.8,166.7 IR(KBr,ν):912,1105,1168,1254,1392,1471,1501,1606,1640,1718,2948

[0078] (Step 3) In a 300 mL recovery flask, 9.37 g (40.0 mmol) of methyl 4-(hex-5-en-1-yloxy)benzoate obtained in step 2, 5.2 g (92.7 mmol) of potassium hydroxide, 200 mL of ethanol, and 32 mL of water were added to obtain solution D. The solution D was stirred at 90° C. for 7 hours. After the stirring, solution D was cooled to room temperature (25° C.) and then added to 300 mL of 2 mol / L hydrochloric acid, and the precipitate was filtered off. By recrystallization with ethanol, 6.85 g of 4-(hex-5-en-1-yloxy)benzoic acid was obtained. The yield at this time was 78%. In addition, the following was reported about the obtained compound: 1 H-NMR (400MHz, CDCl3), 13 The structure was confirmed by C-NMR (400 MHz, CDCl3) and IR (KBr, ν). The reaction scheme for step 3 is as follows: [ka]

[0079] The peaks detected during structure confirmation are as follows: 1 H-NMR(400MHz,CDCl3,δ,ppm):1.56-1.63(m,2H,-CHCH2CH2-),1.84(quin,J=6.4Hz,2H,-CH2CH2O-),2.15(q,J=7.3Hz,2H,CH2CHCH2-) ,4.04(t,J=6.4Hz,2H,-CH2O-),4.98-5.08(m,2H,CH2CH-),5.79-5.89(m,1H,CH),6.94(d,J=8.7Hz,2H,Ar),8.07(d,J=9.16Hz,2H,Ar) 13 C-NMR(400MHz,CDCl3,δ,ppm):25.2,28.5,33.3,68.0,114.1,114.9,121.4,132.3,138.3,163.6,172.3 IR(KBr,ν):915,1457,1514,1607,1642,1686,2665,2941

[0080] (Step 4) In a 200 mL eggplant flask, 6.61 g (30.0 mmol) of 4-(hex-5-en-1-yloxy)benzoic acid obtained in step 3, 1.86 g (10.0 mmol) of 4,4'-dihydroxybiphenyl, 3.79 g (30.0 mmol) of N,N'-Diisopropylcarbodiimide (DIC), a catalytic amount of 4-dimethylaminopyridine, and 100 mL of tetrahydrofuran were added and stirred for 72 hours to obtain a reaction solution E. The reaction solution E was reprecipitated in methanol, and the precipitate was filtered to obtain 5.76 g of [1,1'-biphenyl]-4,4'-diyl bis(4-(hex-5-en-1-yloxy)benzoate). The yield at this time was 97%. In addition, the obtained compound was as follows: 1 H-NMR (400 MHz, CDCl3), and 13 The structure was confirmed by C-NMR (400 MHz, CDCl3). The reaction scheme for step 4 is as follows: [ka]

[0081] The peaks detected during structure confirmation are as follows: 1 H-NMR(400MHz,CDCl3,δ,ppm):1.57-1.64(m,4H,-CHCH2CH2-),1.85(quin,J=6.4Hz,4 H,-CH2CH2O-),2.15(q,J=6.9Hz,4H,CH2CHCH2-),4.06(t,J=6.4Hz,4H,-CH2O-),4.99- 5.08(m,4H,CH2CH-),5.79-5.89(m,2H,CH2CH-),6.98(d,J=8.2Hz,4H,-OArCO-),7.28( d,J=7.8Hz,4H,-ArAr-),7.62(d,J=7.8Hz,4H,-ArAr-),8.17(d,J=8.7Hz,4H,-OArCO-) 13 C-NMR(400MHz,CDCl3,δ,ppm):25.2,28.5,33.4,68.1,114.3,114.9,121.5,122.1,128.2,132.3,138.1,138.4,150.5,163.5,165.0

[0082] (Step 5) In a 100 mL eggplant flask, 3.54 g (6.00 mmol) of [1,1'-biphenyl]-4,4'-diyl bis(4-(hex-5-en-1-yloxy)benzoate) obtained in step 4, 5.18 g (30.0 mmol) of 3-chlorobenzoic acid, and 20 mL of dichloromethane were added and stirred at 0°C for 3 hours, and then 3.11 g (18.0 mmol) of 3-chlorobenzoic acid was added and stirred at 0°C for another 3 hours to obtain reaction solution F. The reaction solution F was filtered, and the filtrate was washed with sodium thiosulfate. After drying with magnesium sulfate, the solvent was distilled off under reduced pressure. Column chromatography was performed on silica gel with dichloromethane, and recrystallization was performed with toluene to obtain 2.55 g of [1,1'-biphenyl]-4,4'-diyl bis(4-(4-(oxiran-2-yl)butoxy)benzoate). The yield was 68%. 1 The structure was confirmed by H-NMR (400 MHz, CDCl3). The reaction scheme for step 5 is as follows: [ka]

[0083] The peaks detected during structure confirmation are as follows: 1 H-NMR(400MHz,CDCl3,δ,ppm):1.56-1.71(m,8H,epoxy CH2CH2-),1.89(quin,J=6.4Hz,4H,-CH2CH2CO-),2.49-2.51(m,2H,epoxy CH),2.77(t,J=4.6Hz,2H,epoxy CH2),2.93-2.96(m,2H,epoxy CH2),4.06(t,J=6.41Hz,4H,-CH2CO-),6.97(d,J=8.7Hz,4H,-OArCO-),7.27(d,J= 8.7Hz,4H,-ArAr-),7.62(d,J=8.7Hz,4H,-ArAr-),8.16(d,J=9.2Hz,4H,-OArCO-)

[0084] (hardening agent) TPK4: A phenolic compound represented by the following structure: [ka] TPK8: A phenolic compound represented by the following structure: [ka] Novolak type: Phenol compound represented by the following structure, "TD-2106" manufactured by DIC Corporation [ka] TP4: A phenolic compound represented by the following structure: [ka] TP8: A phenolic compound represented by the following structure: [ka]

[0085] Among the above curing agents, TPK4 was obtained by the following Synthesis Example 2, TPK8 by the following Synthesis Example 3, TP4 by the following Synthesis Example 4, and TP8 by the following Synthesis Example 5, respectively. [Synthesis Example 2] (Step 1) 9.6 g (72 mmol) of aluminum chloride was added to a 200 mL two-necked eggplant flask and dissolved in 73 mL of dichloromethane under an argon atmosphere to obtain reaction solution G. Reaction solution G was cooled to -10°C, and 9.1 g (66 mmol) of 1,2-dimethoxybenzene was added and stirred for 10 minutes. After that, 5.5 g (30 mmol) of adipoyl chloride was added dropwise, and after stirring for 30 minutes, the mixture was heated to 0°C and stirred for 20 hours to obtain reaction solution H. Reaction solution H was quenched with 2 mol / L hydrochloric acid, and the organic layer was extracted with dichloromethane. The organic layer was washed with a 10 wt% potassium carbonate solution and saturated saline, in that order, and dried with magnesium sulfate. The dried organic layer was reprecipitated in hexane to obtain 10.8 g of 1,6-bis(3,4-dimethoxyphenyl)hexane-1,6-dione. The yield at this time was 93%. In addition, the compound obtained was as follows: 1 The structure was confirmed by H-NMR (400 MHz, CDCl3). The reaction scheme for step 1 is as follows: [ka]

[0086] The peaks detected during structure confirmation are as follows: 1 H-NMR(400MHz,CDCl3,δ,ppm):1.84(quin,J=2.0Hz,4H,-CH2-),3.01(t,J=6.8Hz,4H,-COCH2-),3.94(s ,6H,-OCH3-),3.96(s,6H,-OCH3-),6.89(d,J=8.4Hz,2H,Ar),7.53(s,2H,Ar),7.60(d,J=8.4Hz,2H,Ar)

[0087] (Step 2) In a 100mL two-necked flask, 0.07g (0.5mmol) of potassium carbonate and 1.9g (5mmol) of 1,6-bis(3,4-dimethoxyphenyl)hexane-1,6-dione obtained in step 1 were added. Under a nitrogen atmosphere, 25mL of N-methylpyrrolidinone (NMP) and 4.4g (40mmol) of benzenethiol were added, and the mixture was stirred at 210°C for 3 hours. After cooling to room temperature (25°C), the reaction solution was reprecipitated in 1mol / L hydrochloric acid. The precipitate was then dissolved in DMF, reprecipitated in diethyl ether, and purified by acid precipitation to obtain 1,6-bis(3,4-dihydroxyphenyl)hexane-1,6-dionene (TPK4). The yield at this time was 57%. In addition, the compound obtained was 1 The structure was confirmed by H-NMR (400 MHz, CDCl3). The reaction scheme for step 2 is as follows: [ka]

[0088] The peaks detected during structure confirmation are as follows: 1 H-NMR(400MHz,DMSO-d6,δ,ppm):1.61(quin,J=3.2Hz,4H,-CH2-),2.89(t,J=6.0Hz ,4H,-COCH2-),6.80(d,J=7.9Hz,2H,Ar),7.34(s,2H,Ar),7.36(d,J=7.6Hz,2H,Ar) The melting point obtained by DSC measurement was 261°C.

[0089] [Synthesis Example 3] (Step 1) 4.8 g (36 mmol) of aluminum chloride was added to a 100 mL two-necked eggplant flask and dissolved in 39 mL of dichloromethane under an argon atmosphere to obtain reaction solution I. Reaction solution I was cooled to -10°C, and 4.6 g (33 mmol) of 1,2-dimethoxybenzene was added and stirred for 10 minutes. Then, 3.6 g (15 mmol) of sebacoyl chloride was added dropwise, and the mixture was stirred for 30 minutes, then heated to 0° C. and stirred for 20 hours to obtain reaction solution J. Reaction solution J was quenched with 2 mol / L hydrochloric acid, and the organic layer was extracted with dichloromethane. The organic layer was washed with a 10 wt % potassium carbonate solution and saturated saline, in that order, and dried with magnesium sulfate. The dried organic layer was reprecipitated in hexane to obtain 4.9 g of 1,10-bis(3,4-dimethoxyphenyl)decane-1,10-dione. The yield at this time was 74%. In addition, the following was reported about the obtained compound: 1 The structure was confirmed by H-NMR (400 MHz, CDCl3). The reaction scheme for step 1 is as follows: [ka]

[0090] The peaks detected during structure confirmation are as follows: 1 H-NMR(400MHz,CDCl3,δ,ppm):1.36(m,8H,-CH2-),1.73(quin,J=7.6Hz,4H,-COCH2CH2-),2.92(t,J=7.3Hz,4H,-COC H2-),3.94(s,6H,-OCH3-),3.95(s,6H,-OCH3-),6.89(d,J=7.9Hz,2H,Ar),7.53(s,2H,Ar),7.59(d,J=8.4Hz,2H,Ar)

[0091] (Step 2) In a 100 mL two-necked eggplant flask, 0.14 g (1.0 mmol) of potassium carbonate and 2.2 g (5 mmol) of 1,10-bis(3,4-dimethoxyphenyl)decane-1,10-dione obtained in step 1 were added. Under a nitrogen atmosphere, 25 mL of N-methylpyrrolidinone (NMP) and 4.4 g (40 mmol) of benzenethiol were added, and the mixture was stirred at 210°C for 3 hours. After cooling to room temperature (25°C), the reaction solution was reprecipitated in 1 mol / L hydrochloric acid. The precipitate was further dissolved in THF and reprecipitated in hexane, and the precipitate was purified by acid precipitation to obtain 1.7 g of 1,10-bis(3,4-dihydroxyphenyl)decane-1,10-dione (TPK8). The yield at this time was 89%. In addition, the compound obtained was 1 The structure was confirmed by H-NMR (400 MHz, CDCl3). The reaction scheme for step 2 is as follows: [ka]

[0092] The peaks detected during structure confirmation are as follows: 1 H-NMR(400MHz,CDCl3,δ,ppm):1.27(m,8H,-CH2-),1.55(quin,J=6.7Hz,4H,-COCH2CH2-),2.82 (t,J=7.3Hz,4H,-COCH2-),6.76(d,J=7.9Hz,2H,Ar),7.31(s,2H,Ar),7.33(d,J=8.4Hz,2H,Ar) The melting point obtained by DSC measurement was 245°C.

[0093] [Synthesis Example 4] (Step 1) 1.9 g (5 mmol) of 1,6-bis(3,4-dimethoxyphenyl)hexane-1,6-dione obtained in step 1 of Synthesis Example 2 was added to a 50 mL recovery flask and dissolved in 25 mL of dichloromethane. Then, 0.20 g of 10% Pd / C catalyst was added and stirred at room temperature under a hydrogen atmosphere for 18 hours. After filtering the reaction solution through Celite, the solvent of the obtained filtrate was distilled off under reduced pressure to obtain 1.5 g of the target compound, 1,6-bis(3,4-dimethoxyphenyl)hexane. The yield at this time was 77%. Furthermore, regarding the obtained compound, 1 The structure was confirmed by H-NMR (400 MHz, CDCl3). The reaction scheme for step 1 is as follows: [ka] The peaks detected during structure confirmation are as follows: 1 H-NMR(400MHz,CDCl3,δ,ppm):1.36(quin,J =3.7Hz,4H,-CH2-),1.60(quin,J=6.8Hz,4H, -ArCH2CH2-),2.55(t,J=7.6Hz,4H,-ArCH2-),3.86(s,6H,-OCH3-),3.87(s,6H,-OCH3-), 6.70(s,2H,Ar),6.71(d,J=8.4Hz,2H,Ar),6.78(d,J=8.4Hz,2H,Ar).

[0094] (Step 2) 0.14g (1.0mmol) of potassium carbonate and 0.72g (2mmol) of 1,6-bis(3,4-dimethoxyphenyl)hexane were added to a 30mL two-necked eggplant flask. 10mL of N-methylpyrrolidinone (NMP) and 1.8g (16mmol) of benzenethiol were added under a nitrogen atmosphere, and the mixture was stirred at 210°C for 8 hours. After cooling to room temperature, the reaction solution was added to saturated saline and extracted with THF. The organic layer was dried over magnesium sulfate and reprecipitated in hexane to obtain 0.38g of the target compound, 4,4'-(hexane-1,6-diyl)bis(benzene-1,2-diol). The yield was 54%. The compound obtained was also 1 The structure was confirmed by H-NMR (400 MHz, CDCl3). The reaction scheme for step 2 is as follows: [ka] The peaks detected during structure confirmation are as follows: 1 H-NMR(400MHz,CDCl3,δ,ppm):1.26(quin,J =3.7Hz,4H,-CH2-),1.46(quin,J=6.8Hz,4H, -ArCH2CH2-),2.36(t,J=7.6Hz,4H,-ArCH2-),6.39(d,J=7.6Hz,2H,Ar),6.53(s,2H,Ar),6.60(d,J=8.0Hz,2H,Ar). The melting point obtained by DSC measurement was 135°C.

[0095] [Synthesis Example 5] (Step 1) 2.2 g (5 mmol) of 1,10-bis(3,4-dimethoxyphenyl)decane-1,10-dione obtained in step 1 of Synthesis Example 3 was added to a 50 mL recovery flask and dissolved in 20 mL of dichloromethane. Then, 0.40 g of 10% Pd / C catalyst was added and stirred at room temperature under a hydrogen atmosphere for 36 hours. The reaction solution was filtered through Celite, and the solvent of the obtained filtrate was distilled off under reduced pressure to obtain 1.8 g of the target compound, 1,10-bis(3,4-dimethoxyphenyl)decane. The yield at this time was 81%. In addition, the obtained compound was 1 The structure was confirmed by H-NMR (400 MHz, CDCl3). The reaction scheme for step 1 is as follows: [ka] The peaks detected during structure confirmation are as follows: 1 H-NMR(400MHz,CDCl3,δ,ppm):1.30(m,12H, -CH2-),1.58(quin,J=3.6Hz,4H,-ArCH2CH2-),2.54(t,J=7.6Hz,4H,-ArCH2-),3.86(s,6H,-OCH3-),3.87(s,6H,-OCH3-),6.70(s,2H, Ar),6.72(d,J=5.6Hz,2H,Ar),6.79(d,J=9.2 Hz,2H,Ar).

[0096] (Step 2) 0.14g (1.0mmol) of potassium carbonate and 0.83g (2mmol) of 1,10-bis(3,4-dimethoxyphenyl)decane were added to a 30mL two-necked eggplant flask. 10mL of N-methylpyrrolidinone (NMP) and 1.8g (16mmol) of benzenethiol were added under a nitrogen atmosphere, and the mixture was stirred at 210°C for 8 hours. After cooling to room temperature, the reaction solution was added to saturated saline and extracted with THF. The organic layer was dried over magnesium sulfate and reprecipitated in hexane to obtain 0.52g of the target compound, 4,4'-(decane-1,10-diyl)bis(benzene-1,2-diol). The yield was 73%. The compound obtained was also 1 The structure was confirmed by H-NMR (400 MHz, CDCl3). The reaction scheme for step 2 is as follows: [ka] The peaks detected during structure confirmation are as follows: 1 H-NMR (400MHz, CDCl3, δ, ppm): 1 H-NMR(400MHz,DMSO-d6,δ,ppm): 1.23(m,12H,-CH2-),1.46(quin,J=6.0Hz,4H,-ArCH2CH2-),2.36(t,J=7.2Hz,4H ,-ArCH2-),6.39(d,J=8.0Hz,2H,Ar),6.53(s,2H,Ar),6.60(d,J=8.0Hz,2H,Ar). The melting point obtained by DSC measurement was 133°C.

[0097] (Cure accelerator) Organic phosphine compound: "TPP" manufactured by Hokko Chemical Industry Co., Ltd. (Thermal conductive filler) Alumina: Sumitomo Chemical Co., Ltd., "AA-03", average particle size 3.5 μm

[0098] [Example 1] Each component shown in Table 1 was placed in an aluminum container placed on a hot plate kept at 170°C, and mixed with stirring to prepare a homogeneous epoxy resin composition. This epoxy resin composition was heated in an oven at 200°C for 12 hours to be cured, yielding a homogeneous cured epoxy resin material.

[0099] [Examples 2 to 10, Comparative Examples 1 to 4] The same procedure as in Example 1 was carried out except that the composition of each component was changed as shown in Tables 1 to 4.

[0100] [Table 1]

[0101] As is apparent from Table 1 above, when comparing the curable resin compositions prepared in Examples 1 and 2 and Comparative Example 1, which used an epoxy resin having a mesogenic skeleton, the curable resin compositions prepared in Examples 1 and 2 had relatively high thermal conductivity due to the use of a phenol compound having a predetermined structure as a curing agent. In contrast, the curable resin composition prepared in Comparative Example 1 had a relatively low thermal conductivity because a curing agent not having a specific structure was used.

[0102] [Table 2]

[0103] As is apparent from Table 2 above, when comparing the curable resin compositions prepared in Examples 3 and 4 and Comparative Example 2, which used an epoxy resin having a biphenyl skeleton, the curable resin compositions prepared in Examples 3 and 4 had relatively high thermal conductivity due to the use of a phenol compound having a specified structure as a curing agent. In contrast, the curable resin composition prepared in Comparative Example 2 had a relatively low thermal conductivity because a curing agent not having a specific structure was used.

[0104] [Table 3]

[0105] As is apparent from Table 3 above, when comparing the curable resin compositions prepared in Examples 5 and 6 and Comparative Example 3 using bisphenol A as the epoxy resin, the curable resin compositions prepared in Examples 5 and 6 had relatively high thermal conductivity due to the use of a phenol compound having a predetermined structure as a curing agent. In contrast, the curable resin composition prepared in Comparative Example 3 had a relatively low thermal conductivity because a curing agent not having a specific structure was used. [Table 4] As is clear from Table 4 above, the curable resin compositions prepared in Examples 9 and 10, which contained a thermally conductive filler, had higher thermal conductivity than those prepared in Examples 1 and 2, which did not contain a thermally conductive filler. In contrast, the curable resin composition prepared in Comparative Example 4 had a lower thermal conductivity than those of Examples 9 and 10.

Claims

1. A curable resin composition comprising a curable resin and a phenol compound, The curable resin composition, wherein the phenol compound has a structure represented by the following formula (1): 【Chemistry 1】 (X is a direct bond, -CH=CH-, -C≡C-, -C(=O)-, -C(=O)-O-, -C(=O)-NH-, -CH=N-, -CH=N-N=CH-, -N=N-, -N ＋ (-O － )=N-, -CH=C(CH ３ )-, -CH=C(CN)-, -CH=CH-C(=O)-, -Ph-C(=O)-, -Ph-, -Ph-Ph-, -S(=O) ２ -, -C(=O)OR Ａ -OC(=O)-, -OC(=O)-R Ａ -C(=O)-O-, -C(=O)O-Ph-O-C(=O)-, or -O-C(=O)-Ph-C(=O)-O-, where Ph represents an unsubstituted or substituted aromatic ring, Y represents a linear or branched alkylene chain having 1 to 20 carbon atoms, n represents an integer of 2 to 5, and R Ａ represents an aliphatic hydrocarbon group having 1 to 8 carbon atoms.

2. The curable resin composition according to claim 1 , further comprising a thermally conductive filler and an epoxy resin as the curable resin.

3. The curable resin composition according to claim 1 , wherein the curable resin is an epoxy resin having a mesogenic skeleton.

4. A cured product of the curable resin composition according to claim 1 or 2.

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