Modified epoxy resin, epoxy resin composition, cured product, and laminate for electric / electronic circuit

Abstract

A modified epoxy resin obtained by reacting an epoxy resin (A) having an average of two or more epoxy groups per molecule with an ester compound (B) represented by the following formula (1) having one ester structure per molecule. 1 is an alkyl group which may be substituted or an aryl group which may be substituted. 2 is an aryl group which may or may not have a substituent. The substituent is a group selected from the group consisting of a halogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and an aryl group having 6 to 12 carbon atoms.

Description

Technical Field

[0001] The present invention relates to a modified epoxy resin having excellent heat resistance and low dielectric properties, an epoxy resin composition containing the modified epoxy resin and a curing agent, a cured product thereof, and a laminate for electric / electronic circuits composed of the epoxy resin composition. Background Art

[0002] Epoxy resins have excellent adhesion, water resistance, mechanical strength and electrical properties, so they are used in various fields such as adhesives, coatings, civil engineering materials, and insulating materials for electrical / electronic components. In particular, they are widely used in insulating castings, laminated materials, and sealing materials in the electrical / electronic field. In recent years, due to the development of miniaturization, lightness and multifunctionality of equipment, multilayer circuit substrates used in electrical / electronic equipment are required to be further multilayered, high-density, thin, light, and reliable, as well as to improve molding processability.

[0003] An important property required of an epoxy resin used as a material for electric / electronic components such as an electric / electronic circuit laminate is a low dielectric property.

[0004] In recent years, in order to increase the amount and speed of information transmission, the frequency of communication has been developing at higher frequencies, among which the increase in transmission loss (α) has become a major problem. The lower the value of the transmission loss (α), the less the attenuation of the information signal, which can ensure high reliability of communication. Since α is proportional to the frequency (f), α becomes larger in communications in the high-frequency region, resulting in reduced reliability. As a method for suppressing the transmission loss (α), a method of reducing the dielectric loss tangent (tanδ) which is proportional to α in the same way as the frequency (f) can be cited. In order to transmit communication signals at high speed, materials with low dielectric loss tangent (tanδ), that is, materials with low dielectric properties, are required.

[0005] In addition, electrical / electronic components such as electrical / electronic circuit laminates are required to have high reliability, and in addition to low dielectric properties, they are also required to have a balance of various properties such as heat resistance. In particular, with the increase in the amount of information transmission in the high-frequency region in recent years, the load applied to electronic / electronic circuit laminates has also increased, generating internal heat, so heat resistance in a wider temperature range than before is an essential property.

[0006] The problem to be solved in Patent Document 1 is to provide a cured epoxy resin having low viscosity and low water absorption and excellent heat resistance, and discloses a modified epoxy resin obtained by reacting an acylated polyphenol compound with an epoxy resin.

[0007] The modified epoxy resin disclosed in Patent Document 1 is specifically an epoxy resin obtained by reacting a diacylated phenol compound with a bisphenol-type epoxy resin. Patent Document 1 describes low viscosity, low water absorption, and excellent heat resistance. However, the heat resistance of the modified epoxy resin in Patent Document 1 is not sufficient.

[0008] Furthermore, the present inventors have found that the modified epoxy resin of Patent Document 1 does not have sufficient low dielectric properties (low dielectric loss tangent (low tan δ)) as a material used in a high frequency region, considering the properties required for electrical and electronic components in recent years.

[0009] Patent Document 1: Japanese Patent Laid-Open No. 8-333437 Summary of the invention

[0010] The problem to be solved by the present invention is to provide a modified epoxy resin having an excellent balance between heat resistance and low dielectric properties, an epoxy resin composition containing the modified epoxy resin and a curing agent and its cured product, and a laminate for electric / electronic circuits composed of the epoxy resin composition.

[0011] The present inventors have found that the above-mentioned problems can be solved by an epoxy resin obtained by modifying an epoxy resin with a specific monofunctional ester compound.

[0012] The gist of the present invention is the following [1] to

[11] :

[0013] [1] A modified epoxy resin obtained by reacting an epoxy resin (A) having an average of two or more epoxy groups per molecule with an ester compound (B) represented by the following formula (1) having one ester structure per molecule.

[0014] [Chemistry 1]

[0015]

[0016] In formula (1), R 1 is an alkyl group which may be substituted or an aryl group which may be substituted. 2 is an aryl group which may or may not have a substituent. The substituent is a group selected from the group consisting of a halogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and an aryl group having 6 to 12 carbon atoms.

[0017] [2] The modified epoxy resin according to [1], wherein the reaction equivalent ratio of the epoxy resin (A) to the ester compound (B) is 1.6 to 6.0 in terms of the ratio of the number of moles of epoxy groups of the epoxy resin (A) to the number of moles of ester groups of the ester compound (B).

[0018] [3] The modified epoxy resin according to [1] or [2], wherein R in the formula (1) 1 , R 2 Each is independently a phenyl group which may have a substituent or a naphthyl group which may have a substituent.

[0019] [4] An epoxy resin composition comprising the modified epoxy resin according to any one of [1] to [3] and a curing agent.

[0020] [5] The epoxy resin composition according to [4], wherein the epoxy resin composition contains 0.1 to 100 parts by weight of the curing agent based on 100 parts by weight of the solid content of the modified epoxy resin.

[0021] [6] The epoxy resin composition according to [4] or [5], comprising the modified epoxy resin and another epoxy resin, wherein the weight ratio of the solid content of the modified epoxy resin to the other epoxy resin is 99 / 1 to 1 / 99.

[0022] [7] The epoxy resin composition according to [6], wherein the epoxy resin composition contains 0.1 to 100 parts by weight of the curing agent in terms of solid content, based on 100 parts by weight of the total solid content of the modified epoxy resin and other epoxy resins.

[0023] [8] The epoxy resin composition according to any one of [4] to [7], wherein the curing agent is at least one selected from the group consisting of phenolic curing agents, amide curing agents, imidazoles, and active ester curing agents.

[0024] [9] A cured product obtained by curing the epoxy resin composition according to any one of [4] to [8].

[0025]

[10] A laminate for an electric or electronic circuit, comprising the epoxy resin composition according to any one of [4] to [8].

[0026]

[11] A modified epoxy resin comprising a structure represented by the following formula (4).

[0027] [Chemistry 2]

[0028]

[0029] In formula (4), R 1 is an alkyl group which may be substituted or an aryl group which may be substituted. 2is an aryl group which may or may not have a substituent. The substituent is a group selected from the group consisting of a halogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and an aryl group having 6 to 12 carbon atoms.

[0030] Effects of the Invention

[0031] According to the present invention, a modified epoxy resin, epoxy resin composition and cured product thereof having excellent balance between heat resistance and low dielectric properties can be provided. Therefore, the modified epoxy resin of the present invention and the epoxy resin composition containing the same can be applied to various fields such as adhesives, coatings, civil engineering building materials, and insulating materials for electrical / electronic components. The modified epoxy resin of the present invention and the epoxy resin composition containing the same are particularly useful as insulating castings, laminated materials, sealing materials, etc. in the electrical / electronic field.

[0032] The modified epoxy resin of the present invention and the epoxy resin composition containing the same can be suitably used in multilayer printed wiring boards, laminated boards for electric / electronic circuits such as capacitors, adhesives such as film adhesives and liquid adhesives, semiconductor sealing materials, underfill materials, inter-chip fillers for 3D-LSI (Large Scale Integration), insulating sheets, prepregs, heat dissipation substrates, etc. DETAILED DESCRIPTION

[0033] Hereinafter, embodiments of the present invention will be described in detail.

[0034] The following description is merely an example of an embodiment of the present invention, and the present invention is not limited to the contents described below unless it exceeds the gist of the present invention.

[0035] In the present specification, when the expression "to" is used, it is used as an expression including the numerical values ​​or physical property values ​​before and after it.

[0036] [Modified epoxy resin]

[0037] The modified epoxy resin of the present invention is obtained by reacting an epoxy resin (A) having an average of two or more epoxy groups per molecule with an ester compound (B) represented by the following formula (1) having one ester structure per molecule.

[0038] [Chemistry 3]

[0039]

[0040] In formula (1), R 1 is an alkyl group which may be substituted or an aryl group which may be substituted. 2is an aryl group which may or may not have a substituent. The substituent is a group selected from the group consisting of a halogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and an aryl group having 6 to 12 carbon atoms.

[0041] Furthermore, the modified epoxy resin of the present invention contains a structure represented by the following formula (4).

[0042] [Chemistry 4]

[0043]

[0044] In formula (4), R 1 and R 2 The meaning of is the same as in the above formula (1).

[0045] [mechanism]

[0046] As shown in the above formula (4), the modified epoxy resin of the present invention has a structure in which the ester group of the ester compound (B) is bonded together with the epoxy group of the epoxy resin (A), and this structure improves the low dielectric properties.

[0047] The reasons are speculated as follows:

[0048] As the structure in the ester compound (B), there is one ester group in each molecule and the structure contains an alkyl group or an aryl group with low polarity. Therefore, the structure of formula (4) formed in the reaction with the epoxy group of the epoxy resin (A) is also low polarity and exhibits low dielectric properties. In addition, by appropriately allowing the epoxy group from the epoxy resin (A) to remain in the modified epoxy resin together with the structure of formula (4), the glass transition temperature (Tg) during curing can also be increased.

[0049] Therefore, it is considered that an epoxy resin and a cured product thereof having an excellent balance between low dielectric properties and heat resistance can be obtained.

[0050] [Epoxy resin (A)]

[0051] The epoxy resin (A) used in the present invention is an epoxy resin having an average of two or more epoxy groups per molecule.

[0052] The epoxy resin (A) preferably has an epoxy equivalent of 400 g / equivalent or less, more preferably 350 g / equivalent or less, and even more preferably 300 g / equivalent or less, in order to sufficiently exhibit heat resistance after reaction with the ester compound (B). From the perspective of sufficiently ensuring reactivity with the ester compound (B), the epoxy equivalent of the epoxy resin (A) is preferably 100 g / equivalent or more, more preferably 120 g / equivalent or more, and even more preferably 150 g / equivalent or more.

[0053] In the present invention, “epoxy equivalent” is defined as “the mass of an epoxy resin containing 1 equivalent of epoxy groups” and can be measured in accordance with JIS K 7236.

[0054] As epoxy resin (A), in order to fully demonstrate heat resistance, an epoxy resin having an average of 2 or more epoxy groups per molecule is used. From the perspective of heat resistance, epoxy resin (A) preferably has 2.1 or more epoxy groups, more preferably 2.5 or more epoxy groups, and further preferably 3 or more epoxy groups. On the other hand, from the perspective of operability, epoxy resin (A) preferably has an average of 12 or less epoxy groups per molecule, more preferably 10 or less epoxy groups, and further preferably 8 or less epoxy groups.

[0055] The number of epoxy groups per molecule can be calculated by dividing the number average molecular weight (Mn) measured by gel permeation chromatography (GPC) by the epoxy equivalent. A specific example of the measurement method by GPC will be described in the Examples described below.

[0056] The epoxy resin (A) is not particularly limited as long as it has an average of two or more epoxy groups per molecule, and examples thereof include the following epoxy resins.

[0057] Bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, glycidyl ester type epoxy resin, glycidyl amine type epoxy resin, alicyclic epoxy resin with ester skeleton, bisphenol Z type epoxy resin, anthracene type epoxy resin, naphthalene type epoxy resin, naphthalene tetrafunctional epoxy resin, naphthol type epoxy resin, phenol novolac type epoxy resin, bisphenol A type novolac epoxy resin, cresol novolac type epoxy resin, phenol aralkyl type epoxy resin, biphenyl type epoxy resin, dixylenol type epoxy resin, triphenylmethane type epoxy resin, tetraphenylethane type epoxy resin, dicyclopentadiene type epoxy resin.

[0058] These epoxy resins (A) may be used alone or as a mixture of two or more.

[0059] Among these epoxy resins, preferred are naphthalene tetrafunctional epoxy resins, naphthol-type epoxy resins, phenol novolac-type epoxy resins, bisphenol A-type novolac epoxy resins, cresol novolac-type epoxy resins, phenol aralkyl-type epoxy resins, biphenyl-type epoxy resins, dixylenol-type epoxy resins, triphenylmethane-type epoxy resins, tetraphenylethane-type epoxy resins, and dicyclopentadiene-type epoxy resins; more preferred are phenol novolac-type epoxy resins, bisphenol A-type novolac epoxy resins, cresol novolac-type epoxy resins, phenol aralkyl-type epoxy resins, biphenyl-type epoxy resins, dixylenol-type epoxy resins, triphenylmethane-type epoxy resins, tetraphenylethane-type epoxy resins, and dicyclopentadiene-type epoxy resins.

[0060] [Ester compound (B)]

[0061] The ester compound (B) used in the present invention has one ester structure per molecule and is an ester compound represented by the following formula (1).

[0062] [Chemistry 5]

[0063]

[0064] In formula (1), R 1 is an alkyl group which may be substituted or an aryl group which may be substituted. 2 is an aryl group which may or may not have a substituent. The substituent is a group selected from the group consisting of a halogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and an aryl group having 6 to 12 carbon atoms.

[0065] In formula (1), R 1 and R 2 The substituents do not contain a self-polymerizing substituent.

[0066] The ester structure in the ester compound (B) is a substituent that reacts with an epoxy group. The number of ester structures in each molecule of the ester compound (B) is 1. An ester compound containing two or more ester structures has a risk of excessively reacting with the epoxy group of the epoxy resin (A), increasing the molecular weight of the modified epoxy resin and causing gelation, and thus it is difficult to obtain the desired properties of the modified epoxy resin of the present invention.

[0067] The ester compound having a self-polymerizable substituent deteriorates the stability of the compound itself or the modified epoxy resin, and there is a risk that sufficient curing properties may be difficult to obtain when reacting with a curing agent.

[0068] Here, the "self-polymerizable substituent" refers to a substituent that polymerizes at room temperature or higher, and examples thereof include a vinyl group, an acryloyl group, and a methacrylic group.

[0069] As R in the above formula (1) 1 , preferably an alkyl group having 1 to 12 carbon atoms or an aryl group having 5 to 14 carbon atoms. 2 , preferably an aryl group having 5 to 14 carbon atoms.

[0070] Examples of the alkyl group having 1 to 12 carbon atoms include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, cyclohexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, dodecyl, and cyclododecyl. These groups may have a substituent described below.

[0071] Examples of the aryl group having 5 to 14 carbon atoms include phenyl, biphenyl, naphthyl, anthracenyl, etc. These groups may have a substituent as described below.

[0072] As R in the above formula (1) 1 , R 2 , from the perspective of maintaining good reactivity with epoxy groups, heat resistance, and low dielectric loss tangent, an aryl group having 5 to 14 carbon atoms is more preferred. Examples of the aryl group having 5 to 14 carbon atoms include phenyl, biphenyl, naphthyl, anthracenyl, etc. These groups may have a substituent described below.

[0073] R 1 The alkyl or aryl group and R 2 The substituents optionally possessed by the aryl group are selected from the group consisting of halogen atoms, alkyl groups having 1 to 12 carbon atoms, alkoxy groups having 1 to 12 carbon atoms, and aryl groups having 6 to 12 carbon atoms. 1 , R 2 Provides self-polymerization.

[0074] Examples of the alkyl group having 1 to 12 carbon atoms as the substituent include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neopentyl, tert-pentyl, cyclopentyl, n-hexyl, isohexyl, cyclohexyl, n-heptyl, cycloheptyl, methylcyclohexyl, n-octyl, cyclooctyl, n-nonyl, 3,3,5-trimethylcyclohexyl, n-decyl, cyclodecyl, n-undecyl, n-dodecyl, cyclododecyl, benzyl, methylbenzyl, dimethylbenzyl, trimethylbenzyl, naphthylmethyl, phenethyl, and 2-phenylisopropyl.

[0075] Examples of the alkoxy group having 1 to 12 carbon atoms as the substituent include a methoxy group, an ethoxy group, an n-propoxy group, an isopropoxy group, an n-butoxy group, a sec-butoxy group, a tert-butoxy group, an n-pentyloxy group, an isopentyloxy group, a neopentyloxy group, a tert-pentyloxy group, a cyclopentyloxy group, an n-hexyloxy group, an isohexyloxy group, a cyclohexyloxy group, an n-heptyloxy group, a cycloheptyloxy group, a methylcyclohexyloxy group, an n-octyloxy group, a cyclooctyloxy group, an n-nonyloxy group, a 3,3,5-trimethylcyclohexyloxy group, an n-decyloxy group, a cyclodecyloxy group, an n-undecyloxy group, an n-dodecyloxy group, a cyclododecyloxy group, a benzyloxy group, a methylbenzyloxy group, a dimethylbenzyloxy group, a trimethylbenzyloxy group, a naphthylmethoxy group, a phenethoxy group, and a 2-phenylisopropoxy group.

[0076] Examples of the aryl group having 6 to 12 carbon atoms as the substituent include phenyl, o-tolyl, m-tolyl, p-tolyl, ethylphenyl, styryl, xylyl, n-propylphenyl, isopropylphenyl, mesityl, ethynylphenyl, naphthyl, and vinylnaphthyl.

[0077] Among the substituents listed above, R1 With R 2 The substituent optionally present in is preferably an alkyl group having 1 to 4 carbon atoms, a halogen atom, etc., and more preferably a methyl group. 1 , R 2 It has no substituent or has a methyl group as a substituent. The reason is that when the substituent is too bulky, it hinders the aggregation of molecules and may reduce heat resistance.

[0078] The ester compound (B) represented by the above formula (1) is particularly preferably a compound represented by the following formula (2) or (3).

[0079] [Chemistry 6]

[0080]

[0081] In formulas (2) and (3), R 3 , R 4 , R 5 Each is independently a group arbitrarily selected from a halogen atom, an alkyl group having 1 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and an aryl group having 6 to 12 carbon atoms. n represents an integer of 0 to 5, and m represents an integer of 0 to 7.

[0082] R 3 , R 4 , R 5 Specific examples and preferred substituents are the same as those mentioned above as R 1 The alkyl or aryl group and R 2 The substituents optionally possessed by the aryl group of are the same.

[0083] The naphthalene ring in the formula (3) is preferably bonded to the oxygen atom of the ester group at the 1-position or the 2-position, and more preferably at the 2-position.

[0084] n is an integer of 0 to 5, preferably 0 to 2, more preferably 0 to 1, and particularly preferably 0.

[0085] m is an integer of 0 to 7, preferably 0 to 3, more preferably 0 to 1, and particularly preferably 0.

[0086] These ester compounds (B) may be used alone or as a mixture of two or more.

[0087] [Chemical structure of modified epoxy resin]

[0088] The modified epoxy resin of the present invention contains a structure represented by the following formula (4), which can be obtained by reacting the epoxy group of the epoxy resin (A) with the ester group of the ester compound (B). As described above, due to the structure represented by the following formula (4), the effect of improving heat resistance and low dielectric properties can be obtained.

[0089] [Chemistry 7]

[0090]

[0091] In formula (4), R 1 , R 2 The meaning of is the same as that in the above formula (1).

[0092] [Weight average molecular weight (Mw)]

[0093] The weight average molecular weight (Mw) of the modified epoxy resin of the present invention is preferably in the range of 500 to 10,000. As long as the Mw is 500 or more, there is no risk of deterioration in dielectric properties or water absorption. From the perspective of better maintaining these properties, the Mw of the modified epoxy resin of the present invention is more preferably 600 or more, further preferably 700 or more, and particularly preferably 1,000 or more. From the perspective of properly maintaining the viscosity and softening point of the resin and making the operability good, the Mw of the modified epoxy resin of the present invention is preferably 10,000 or less, more preferably 8,000 or less, further preferably 7,000 or less, and particularly preferably 6,000 or less.

[0094] Mw can be measured by gel permeation chromatography (GPC method). About the measurement method by GPC, a specific example is demonstrated in the Example mentioned later.

[0095] [Epoxy equivalent]

[0096] The epoxy equivalent of the modified epoxy resin of the present invention is preferably in the range of 300 to 1,000 g / equivalent. From the perspective of maintaining good heat resistance, the epoxy equivalent of the modified epoxy resin of the present invention is preferably 1,000 g / equivalent or less, more preferably 900 g / equivalent or less, and further preferably 800 g / equivalent or less. From the perspective of maintaining good dielectric properties and water absorption, the epoxy equivalent of the modified epoxy resin of the present invention is preferably 300 g / equivalent or more, more preferably 330 g / equivalent or more, and particularly preferably 360 g / equivalent or more.

[0097] [Softening point]

[0098] The softening point of the modified epoxy resin of the present invention in a solid state is preferably in the range of 60 to 130° C. From the viewpoint of suppressing resin agglomeration, the softening point of the modified epoxy resin of the present invention is more preferably 65° C. or higher, further preferably 70° C. or higher, and particularly preferably 75° C. or higher. In order to fully ensure solvent solubility, the softening point of the modified epoxy resin of the present invention is more preferably 125° C. or lower, further preferably 120° C. or lower, and particularly preferably 115° C. or lower.

[0099] Here, the softening point can be measured in accordance with JIS K7234.

[0100] Agglomeration refers to the phenomenon that the resin flakes of powder partially melt during storage and form lumps, which impairs the workability.

[0101] [Method for producing modified epoxy resin]

[0102] The modified epoxy resin of the present invention is obtained by reacting the epoxy resin (A) having an average of two or more epoxy groups per molecule with the ester compound (B) represented by the above formula (1) having one ester structure per molecule.

[0103] As the preparation method of epoxy resin (A), for example, a method of condensing a bisphenol compound or various novolac compounds with an epihalohydrin using a known method can be cited. As the preparation method of other epoxy resins, a method of introducing an allyl group into a phenol or novolac compound by an allylation reaction to form an allyl compound, and further oxidizing the allyl group can be cited. Commercially available epoxy resins can also be used as epoxy resin (A).

[0104] The ester compound (B) can be produced by, for example, subjecting an alcohol compound or a phenol compound to a condensation reaction with an acid chloride or a carboxylic acid to esterification.

[0105] In the manufacture of the modified epoxy resin of the present invention, the reaction equivalent ratio of the epoxy resin (A) and the ester compound (B) is preferably 1.6 to 6.0 in terms of the ratio of the number of moles of epoxy groups of the epoxy resin (A) to the number of moles of ester groups of the ester compound (B) (hereinafter, sometimes referred to as "molar ratio (epoxy group / ester group)"). When the molar ratio (epoxy group / ester group) is within the above range, the amount of epoxy groups after the modification reaction can be kept optimal, and the properties of good balance of heat resistance and dielectric properties can be exhibited. From the perspective of further maintaining a good balance between heat resistance and dielectric properties, the molar ratio (epoxy group / ester group) is more preferably 1.62 or more, more preferably 1.63 or more, and particularly preferably 1.65 or more. From the same perspective, the molar ratio (epoxy group / ester group) is more preferably 5.5 or less, more preferably 5.0 or less, and particularly preferably 4.5 or less.

[0106] A catalyst may also be used in the manufacture of the modified epoxy resin of the present invention. As the catalyst, any compound may be used as long as it has a catalytic ability to promote the reaction between the epoxy group and the ester group. Examples of the catalyst include tertiary amines, cyclic amines, imidazoles, organic phosphorus compounds, quaternary ammonium salts, and the like.

[0107] Specific examples of the tertiary amine include triethylamine, tri-n-propylamine, tri-n-butylamine, triethanolamine, benzyldimethylamine, pyridine, and 4-(dimethylamino)pyridine.

[0108] Specific examples of the cyclic amines include 1,4-diazabicyclo[2,2,2]octane, 1,8-diazabicyclo[5,4,0]undecene-7, and 1,5-diazabicyclo[4,3,0]nonene-5-ene.

[0109] Specific examples of imidazoles include 2-methylimidazole, 2-ethyl-4-methylimidazole, and 2-phenylimidazole.

[0110] Specific examples of the organophosphorus compound include tri-n-propylphosphine, tri-n-butylphosphine, triphenylphosphine, tri(p-tolyl)phosphine, tricyclohexylphosphine, tri(tert-butyl)phosphine, tri(p-methoxyphenyl)phosphine, tetramethylphosphonium bromide, tetramethylphosphonium iodide, tetramethylphosphonium hydroxide, tetrabutylphosphonium hydroxide, trimethylcyclohexylphosphonium chloride, trimethylcyclohexylphosphonium bromide, trimethylbenzylphosphonium chloride, trimethylbenzylphosphonium bromide, tetraphenylphosphonium bromide, triphenylmethylphosphonium bromide, triphenylmethylphosphonium iodide, triphenylethylphosphonium chloride, triphenylethylphosphonium bromide, triphenylethylphosphonium iodide, triphenylbenzylphosphonium chloride, and triphenylbenzylphosphonium bromide.

[0111] Among the catalysts listed above, preferred are 4-(dimethylamino)pyridine, 1,4-diazabicyclo[2,2,2]octane, 1,8-diazabicyclo[5,4,0]undecene-7, 1,5-diazabicyclo[4,3,0]nonene-5, 2-ethyl-4-methylimidazole, tri(p-tolyl)phosphine, tricyclohexylphosphine, tri(tert-butyl)phosphine, and tri(p-methoxyphenyl)phosphine, and particularly preferred are 4-(dimethylamino)pyridine, 1,8-diazabicyclo[5,4,0]undecene-7, 1,5-diazabicyclo[4,3,0]nonene-5, and 2-ethyl-4-methylimidazole.

[0112] These catalysts may be used alone or in combination of two or more.

[0113] The amount of the catalyst used is usually 0.001 to 1% by weight of the reaction solid content. When a catalyst is used, the catalyst compound remains as catalyst residue in the resulting modified epoxy resin, which may deteriorate the insulation properties or shorten the effective life of the composition when used in a printed wiring board.

[0114] Therefore, the content of nitrogen from the catalyst in the obtained modified epoxy resin is preferably 2000 ppm or less, and the content of phosphorus is preferably 2000 ppm or less. More preferably, the content of nitrogen in the modified epoxy resin is 1000 ppm or less, and the content of phosphorus is 1000 ppm or less. Further preferably, the content of nitrogen in the modified epoxy resin is 500 ppm or less, and the content of phosphorus is 500 ppm or less. Particularly preferably, the content of nitrogen in the modified epoxy resin is 200 ppm or less, and the content of phosphorus is 200 ppm or less. The lower limit of the content of nitrogen and phosphorus from the catalyst is not particularly limited, but it is about 1 ppm from the lower limit of the detection limit of the measuring equipment.

[0115] The modified epoxy resin of the present invention may also use a solvent for the reaction in the step of the synthesis reaction when it is manufactured. As the solvent, any solvent may be used as long as it dissolves the epoxy resin. As the solvent, for example, aromatic solvents, ketone solvents, amide solvents, glycol ether solvents, etc. may be mentioned. These solvents may be used alone or in combination of two or more.

[0116] Specific examples of the aromatic solvent include benzene, toluene, and xylene.

[0117] Specific examples of the ketone solvent include acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, 2-heptanone, 4-heptanone, 2-octanone, cyclohexanone, acetylacetone, and dioxane.

[0118] Specific examples of the amide solvent include formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, 2-pyrrolidone, and N-methylpyrrolidone.

[0119] Specific examples of the glycol ether-based solvent include ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol dimethyl ether, ethylene glycol monoethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-butyl ether, diethylene glycol dimethyl ether, diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether, propylene glycol mono-n-butyl ether, and propylene glycol monomethyl ether acetate.

[0120] When a solvent is used in the production of the modified epoxy resin, it is preferably used so that the solid content concentration of the reaction system is 35 to 95% by weight.

[0121] When a highly viscous product is generated during the reaction, additional solvent may be added to continue the reaction.

[0122] After the reaction is completed, the solvent may be removed or further added as necessary.

[0123] In the production of the modified epoxy resin of the present invention, the reaction of the epoxy resin (A) and the ester compound (B) is carried out at a reaction temperature at which the catalyst used does not decompose. When the reaction temperature is too high, there is a risk that the catalyst decomposes to stop the reaction or the generated modified epoxy resin deteriorates. On the contrary, when the temperature is too low, there is a situation where the reaction cannot be fully carried out.

[0124] For these reasons, the reaction temperature is preferably 50 to 200°C, more preferably 100 to 180°C, and further preferably 120 to 160°C.

[0125] The reaction time is usually 1 to 12 hours, preferably 3 to 10 hours.

[0126] When a low boiling point solvent such as acetone or methyl ethyl ketone is used, the reaction temperature can be ensured by conducting the reaction under high pressure using an autoclave.

[0127] [Epoxy resin composition]

[0128] The epoxy resin composition of the present invention is an epoxy resin composition containing at least the modified epoxy resin of the present invention and a curing agent. The epoxy resin composition of the present invention is preferably an epoxy resin composition containing the structure of the above formula (4).

[0129] In addition, the epoxy resin composition of the present invention can be appropriately formulated with various additives such as other epoxy resins, inorganic fillers, coupling agents, antioxidants, etc. in addition to the modified epoxy resin of the present invention as needed. The epoxy resin composition of the present invention can provide a cured product having excellent heat resistance and low dielectric properties and fully satisfying various physical properties required for various uses.

[0130] [Curing agent]

[0131] In the present invention, the curing agent refers to a substance that contributes to the cross-linking reaction and / or chain extension reaction between epoxy groups of the epoxy resin.

[0132] In the present invention, even if it is generally called a "curing accelerator", as long as it contributes to the cross-linking reaction and / or chain extension reaction between epoxy groups of the epoxy resin, it is regarded as a curing agent.

[0133] The content of the curing agent in the epoxy resin composition of the present invention is preferably 0.1 to 100 parts by weight, more preferably 90 parts by weight or less, and even more preferably 80 parts by weight or less, based on 100 parts by weight of the solid content of the modified epoxy resin of the present invention.

[0134] When the epoxy resin composition of the present invention contains other epoxy resins described below, the weight ratio of the solid content of the modified epoxy resin of the present invention to the other epoxy resins is preferably 99 / 1 to 1 / 99.

[0135] In this case, the content of the curing agent in the epoxy resin composition of the present invention is preferably 0.1 to 100 parts by weight, more preferably 90 parts by weight or less, and further preferably 80 parts by weight or less, based on the solid content, relative to 100 parts by weight of the total solid content of the modified epoxy resin of the present invention and other epoxy resins.

[0136] In the present invention, "solid content" refers to components other than the solvent, and includes not only solid epoxy resin but also semi-solid or viscous liquid components.

[0137] The “total epoxy resin component” refers to the total of the modified epoxy resin of the present invention and other epoxy resins described below.

[0138] The curing agent used in the epoxy resin composition of the present invention is not particularly limited, and any curing agent generally known as an epoxy resin curing agent can be used. From the perspective of improving heat resistance, preferred curing agents include phenolic curing agents, amide curing agents, imidazoles, and active ester curing agents. The following lists examples of phenolic curing agents, amide curing agents, imidazoles, active ester curing agents, and other curing agents that can be used.

[0139] [Phenolic curing agent]

[0140] From the viewpoint of improving the handleability of the epoxy resin composition obtained and the heat resistance after curing, it is preferred to use a phenolic curing agent as the curing agent.

[0141] Specific examples of the phenolic curing agent include bisphenol A, bisphenol F, 4,4′-dihydroxydiphenylmethane, 4,4′-dihydroxydiphenyl ether, 1,4-bis(4-hydroxyphenoxy)benzene, 1,3-bis(4-hydroxyphenoxy)benzene, 4,4′-dihydroxydiphenyl sulfide, 4,4′-dihydroxybenzophenone, 4,4′-dihydroxydiphenyl sulfone, 4,4′-dihydroxybiphenyl, 2,2′-dihydroxybiphenyl, 10-(2,5-dihydroxyphenyl)-10H-9-oxa-10-phosphaphenanthrene-10-oxide, phenol novolac, bisphenol A novolac, o-cresol novolac, m-cresol novolac, p-cresol novolac, xylenol novolac, polyparahydroxystyrene, hydroquinone, resorcinol, catechol, Tert-butylcatechol, tert-butylhydroquinone, phloroglucinol, pyrogallol, tert-butylpyrogallol, allylated pyrogallol, polyallylated pyrogallol, 1,2,4-benzenetriol, 2,3,4-trihydroxybenzophenone, 1,2-dihydroxynaphthalene, 1,3-dihydroxynaphthalene, 1,4-dihydroxynaphthalene, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 1,7-dihydroxynaphthalene, 1,8-dihydroxynaphthalene, 2,3-dihydroxynaphthalene, 2,4-dihydroxynaphthalene, 2,5-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, 2,7-dihydroxynaphthalene, 2,8-dihydroxynaphthalene, allylated or polyallylated products of the above dihydroxynaphthalenes, allylated bisphenol A, allylated bisphenol F, allylated phenol novolac, allylated pyrogallol, and the like.

[0142] The phenolic curing agents listed above may be used alone or in combination of two or more in any ratio.

[0143] When the curing agent is a phenolic curing agent, it is preferably used so that the equivalent ratio of the functional groups in the curing agent to the epoxy groups in the total epoxy resin in the epoxy resin composition is in the range of 0.8 to 1.5. Within this range, unreacted epoxy groups or functional groups of the curing agent are less likely to remain, which is preferred.

[0144] [Amide curing agent]

[0145] From the viewpoint of improving the heat resistance of the obtained epoxy resin composition, it is preferred to use an amide-based curing agent as the curing agent.

[0146] Examples of the amide curing agent include dicyandiamide and its derivatives, and polyamide resins.

[0147] The amide curing agents listed above may be used alone or in combination of two or more in any ratio.

[0148] The amide curing agent is preferably used in an amount within a range of 0.1 to 20% by weight relative to the total amount of the total epoxy resin component and the amide curing agent as the solid content in the epoxy resin composition.

[0149] [Imidazoles]

[0150] From the viewpoint of sufficiently advancing the curing reaction and improving the heat resistance, it is preferred to use imidazoles as the curing agent.

[0151] Examples of imidazoles include 2-phenylimidazole, 2-ethyl-4(5)-methylimidazole, 2-phenyl-4-methylimidazole, 1-benzyl-2-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole, 1-cyano-2-phenylimidazole, 1-cyanoethyl-2-undecylimidazole trimellitate, 1-cyanoethyl-2-phenylimidazolium trimellitate, 2,4-diamino-6-[2′-methylimidazolyl-(1′)]-ethyl-symmetric tris(2,4-diamino) ... 2,4-Diamino-6-[2′-ethyl-4′-methylimidazolyl-(1′)]-ethyl-s-triazine 2,4-Diamino-6-[2′-methylimidazolyl-(1′)]-ethyl-s-triazine Isocyanuric acid adducts, 2-phenylimidazole isocyanuric acid adducts, 2-phenyl-4,5-dihydroxymethylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, and adducts of epoxy resins and the above imidazoles.

[0152] Since imidazoles have catalytic ability, they can generally be classified as curing accelerators described below, but they are classified as curing agents in the present invention.

[0153] The above-mentioned imidazoles may be used alone or in combination of two or more in any ratio.

[0154] The imidazole is preferably used in an amount within a range of 0.1 to 20% by weight relative to the total amount of the total epoxy resin component and the imidazole as the solid content in the epoxy resin composition.

[0155] [Active ester curing agent]

[0156] From the viewpoint that the obtained cured product exhibits low water absorption and low dielectric properties, it is preferred to use an active ester-based curing agent as the curing agent.

[0157] As active ester curing agent, preferably phenolic esters, thiophenolic esters, N-hydroxylamine esters, esters of heterocyclic hydroxy compounds, etc., have ester groups with more than 2 reactive activities in each molecule, wherein more preferably phenolic esters obtained by reacting carboxylic acid compounds with aromatic compounds having phenolic hydroxyl groups. As carboxylic acid compounds, specifically, benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, pyromellitic acid, etc. can be listed. As aromatic compounds with phenolic hydroxyl groups, catechol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucinol, benzenetriol, dicyclopentadienyl diphenol, phenol novolac, etc. can be listed. As similar curing agent, polyarylate can also be used.

[0158] Examples of commercially available active ester curing agents include HPC-8000-65T (an active ester curing agent containing a dicyclopentadiene structure) and HPC-8150-60T (an active ester curing agent containing a naphthalene structure in the main skeleton) (each manufactured by DIC Corporation).

[0159] The active ester curing agents listed above may be used alone or in combination of two or more in any ratio.

[0160] The active ester-based curing agent is preferably used so that the equivalent ratio of the active ester group in the curing agent to the epoxy group in the total epoxy resin in the epoxy resin composition is in the range of 0.2 to 2.0.

[0161] [Other curing agents]

[0162] As other curing agents other than those mentioned above that can be used in the epoxy resin composition of the present invention, for example, amine curing agents (but excluding tertiary amines), acid anhydride curing agents, tertiary amines, organic phosphines, phosphonium salts, tetraphenylborate salts, organic acid dihydrazides, halide boron amine complexes, polythiol curing agents, isocyanate curing agents, blocked isocyanate curing agents, etc.

[0163] The other curing agents listed above may be used alone or in combination of two or more in any ratio.

[0164] [Other epoxy resins]

[0165] In addition to the modified epoxy resin of the present invention, the epoxy resin composition of the present invention may further contain other epoxy resins. By using other epoxy resins, insufficient physical properties can be compensated or various physical properties can be improved.

[0166] As other epoxy resins, epoxy resins having two or more epoxy groups in the molecule are preferred. As other epoxy resins, various epoxy resins such as bisphenol A type epoxy resin, bisphenol F type epoxy resin, bisphenol S type epoxy resin, bisphenol AF type epoxy resin, bisphenol Z type epoxy resin, naphthalene type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, phenol aralkyl type epoxy resin, biphenyl type epoxy resin, triphenylmethane type epoxy resin, dicyclopentadiene type epoxy resin can be used.

[0167] These may be used alone or in combination of two or more.

[0168] In the epoxy resin composition of the present invention, when the modified epoxy resin of the present invention and other epoxy resins are used, the amount of other epoxy resins added in 100% by weight of the total epoxy resin component as the solid component is preferably 1% by weight or more, more preferably 5% by weight or more, further preferably 10% by weight or more, preferably 99% by weight or less, more preferably 95% by weight or less, and further preferably 90% by weight or less. By having the ratio of other epoxy resins being above the lower limit, the effect of improving the physical properties by adding other epoxy resins can be fully obtained. By having the ratio of other epoxy resins being below the upper limit, the effect of the modified epoxy resin of the present invention is fully exerted, and it is preferably preferred from the perspective of obtaining the effect of improving the physical properties such as low hygroscopicity.

[0169] [Solvent]

[0170] In order to appropriately adjust the viscosity of the epoxy resin composition during the operation of forming a coating film, a solvent may be added to the epoxy resin composition containing the modified epoxy resin of the present invention for dilution.

[0171] In the epoxy resin composition of the present invention, the solvent is used to ensure the operability and processability of the epoxy resin composition during molding, and the amount of the solvent used is not particularly limited.

[0172] In the present invention, the term "solvent" and the term "medium" mentioned above are used differently depending on the manner of use, but the same substance or different substances may be used independently of each other.

[0173] Examples of solvents that may be contained in the epoxy resin composition containing the modified epoxy resin of the present invention include ketones such as acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, and cyclohexanone; esters such as ethyl acetate; ethers such as ethylene glycol monomethyl ether, amides such as N,N-dimethylformamide and N,N-dimethylacetamide; alcohols such as methanol and ethanol; alkanes such as hexane and cyclohexane; aromatics such as toluene and xylene, and the like.

[0174] The above-mentioned solvents may be used alone or in combination of two or more in any ratio.

[0175] [Other ingredients]

[0176] The epoxy resin composition containing the modified epoxy resin of the present invention may also contain ingredients other than those listed above (sometimes referred to as "other ingredients" in the present invention) in order to further improve its functionality. Such other ingredients include: thermosetting resins or photocurable resins other than epoxy resins, curing accelerators (but not including those contained in "curing agents"), ultraviolet inhibitors, antioxidants, coupling agents, plasticizers, flux, flame retardants, colorants, dispersants, emulsifiers, low elasticity agents, diluents, defoamers, ion scavengers, inorganic fillers, organic fillers, etc.

[0177] [cured material]

[0178] The cured product obtained by curing the modified epoxy resin of the present invention with a curing agent has an excellent balance between heat resistance and low dielectric properties and exhibits good cured physical properties. The cured product of the present invention is preferably a cured product containing the structure of the above formula (4).

[0179] The term "curing" as used herein refers to intentionally curing the epoxy resin composition by heat and / or light, and the degree of curing can be controlled according to the desired physical properties and application. The degree of curing can be fully cured or semi-cured, and there is no particular limitation. Generally, the reaction rate of the curing reaction between the epoxy group and the curing agent is 5 to 95%.

[0180] The curing method of the epoxy resin composition of the present invention when curing to form a cured product also varies depending on the ingredients or amounts added in the epoxy resin composition, but generally, the conditions of heating at 80 to 280°C for 60 to 360 minutes can be cited. The heating is preferably carried out in two steps, and the two-step treatment is divided into a primary heating at 80 to 160°C for 10 to 90 minutes and a secondary heating at 120 to 200°C for 60 to 150 minutes. Preferably, a third heating is further carried out at 150 to 280°C for 60 to 120 minutes in a mixed system where the glass transition temperature (Tg) exceeds the temperature of the secondary heating. From the perspective of reducing poor curing or solvent residue, it is preferred to perform secondary heating and tertiary heating in this way.

[0181] When preparing a semi-cured resin, it is preferred to perform a curing reaction of the epoxy resin composition by heating or the like to a degree that the shape can be maintained. When the epoxy resin composition contains a solvent, most of the solvent is usually removed by heating, reducing pressure, air drying, etc. Less than 5% by weight of the solvent may remain in the semi-cured resin.

[0182] [use]

[0183] The modified epoxy resin of the present invention has excellent film-forming properties. The epoxy resin composition containing the modified epoxy resin of the present invention can provide a cured product having excellent heat resistance and low dielectric properties. Therefore, the modified epoxy resin of the present invention and the epoxy resin composition containing the same can be applied to various fields such as adhesives, coatings, civil engineering and construction materials, and insulating materials for electrical / electronic components, and are particularly useful as insulating castings, laminated materials, sealing materials, etc. in the electrical / electronic field.

[0184] As an example of the use of the modified epoxy resin of the present invention and the epoxy resin composition containing the same, there can be listed: multilayer printed wiring boards, laminated boards for electric / electronic circuits such as capacitors, adhesives such as film adhesives and liquid adhesives, semiconductor sealing materials, bottom filling materials, inter-chip fillers for 3D-LSI, insulating sheets, prepregs, heat dissipation substrates, etc. The use of the modified epoxy resin of the present invention and the epoxy resin composition containing the same is not limited to these.

[0185] [Laminated boards for electrical / electronic circuits]

[0186] As described above, the epoxy resin composition of the present invention can be suitably used for the purpose of a laminated board for electric / electronic circuits. In the present invention, "laminated board for electric / electronic circuits" means a laminated board comprising a layer containing the epoxy resin composition of the present invention and a conductive metal layer. If a laminated board comprising a layer containing the epoxy resin composition of the present invention and a conductive metal layer is formed, even if it is not an electric / electronic circuit, it can be used as a concept including, for example, a capacitor.

[0187] The electric / electronic circuit laminate may include layers composed of two or more epoxy resin compositions, and the epoxy resin composition of the present invention may be used in at least one layer. The electric / electronic circuit laminate may include two or more conductive metal layers.

[0188] In the laminate for electric / electronic circuits, the thickness of the layer composed of the epoxy resin composition is usually about 10 to 200 μm, and the thickness of the conductive metal layer is usually about 0.2 to 70 μm.

[0189] [Conductive metal]

[0190] The conductive metal in the laminate for electric / electronic circuits includes metals such as copper and aluminum or alloys containing these metals. The conductive metal layer of the laminate for electric / electronic circuits may be a metal foil of these metals or a metal layer formed by plating or sputtering.

[0191] [Method for producing laminated board for electric / electronic circuit]

[0192] As a method for producing the electric / electronic circuit laminate in the present invention, for example, the following method can be mentioned.

[0193] (1) A nonwoven fabric or fabric using inorganic and / or organic fiber materials such as glass fiber, polyester fiber, aromatic polyamide fiber, cellulose, nanocellulose, etc. is impregnated with the epoxy resin composition of the present invention to form a prepreg, and a conductive metal foil is provided and / or a conductive metal layer is provided by plating, and then a circuit is formed using a photoresist, and a required number of layers are stacked to form a laminate.

[0194] (2) The prepreg of (1) above is used as a core material, and a layer composed of an epoxy resin composition and a conductive metal layer are laminated thereon (on one side or both sides) (lamination method). The layer composed of the epoxy resin composition may contain an organic and / or inorganic filler.

[0195] (3) A laminate for an electric / electronic circuit is formed by alternately laminating layers composed of an epoxy resin composition and conductive metal layers without using a core material.

[0196] Example

[0197] Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to the following examples at all.

[0198] The values ​​of various manufacturing conditions or evaluation results in the following examples have the meaning of preferred values ​​as the upper or lower limits of the embodiments of the present invention, and the preferred range can be the range specified by the combination of the value of the upper or lower limit and the value of the following examples or the values ​​of the examples themselves.

[0199] [Evaluation methods of physical properties / characteristics]

[0200] In the following Examples and Comparative Examples, evaluations of physical properties / characteristics were performed by the methods described in the following 1) to 6).

[0201] 1) Weight average molecular weight (Mw) and number average molecular weight (Mn)

[0202] The HLC-8320GPC device manufactured by Tosoh Corporation was used to plot the TSK Standard Polystyrene (standard polystyrene): F-128 (Mw: 1,090,000, Mn: 1,030,000), F-10 (Mw: 106,000, Mn: 103,000), F-4 (Mw: 43,000, Mn: 42,700), F-2 (Mw: 17,200, Mn: 16,900), A-5000 (Mw: 6,400, Mn: 6,100), A-2500 (Mw: 2,800, Mn: 2,700), A-300 (Mw: 453, Mn: 387) were used as a calibration curve of standard polystyrene, and the weight average molecular weight (Mw) and number average molecular weight (Mn) were measured as polystyrene conversion values.

[0203] Chromatographic column: "TSKGEL SuperHM-H+H5000+H4000+H3000+H2000" manufactured by Tosoh Corporation

[0204] Eluent: Tetrahydrofuran

[0205] Flow rate: 0.5ml / min

[0206] Detection: UV (wavelength 254nm)

[0207] Temperature: 40℃

[0208] Sample concentration: 0.1 wt%

[0209] Injection volume: 10μl

[0210] 2) The average number of epoxy groups per molecule of the raw epoxy resin

[0211] The value calculated was obtained by dividing the number average molecular weight obtained by GPC measurement by the epoxy equivalent.

[0212] 3) Epoxy equivalent

[0213] The measurement was performed in accordance with JIS K7236, and in the case of a solution, the value was expressed as a solid content conversion value.

[0214] 4) Softening point

[0215] The softening point of the solid epoxy resin was measured in accordance with JIS K7234.

[0216] 5) Heat resistance of cured product: glass transition temperature (Tg, DSC)

[0217] The epoxy resin cured film having a thickness of about 50 μm obtained by drying and curing the epoxy resin composition solution was heated to 30 to 250° C. at 10° C. / min using “DSC7020” manufactured by SII NanoTechnology Co., Ltd. to measure the glass transition temperature.

[0218] The glass transition temperature referred to herein is measured based on the “midpoint glass transition temperature: Tmg” described in JIS K7121 “Determination of transition temperature of plastics”.

[0219] The criteria for determining the glass transition temperature are as follows:

[0220] Tg 120℃ or above: Judgment ◎

[0221] Tg 100℃ or higher and less than 120℃: Judged as ○

[0222] Tg is less than 100℃: judgment ×

[0223] 6) Dielectric properties

[0224] The epoxy resin cured film or the produced prepreg was cut into a test piece of 2 mm in width and 80 mm in length. The dielectric loss tangent (tan δ) of the test piece was measured at a measurement frequency of 10 GHz and a measurement temperature of 23° C. using a network analyzer and a cavity resonance perturbation method.

[0225] The criteria for determining dielectric properties are as follows:

[0226] tanδ≤0.0075: Judgement A

[0227] 0.0075<tanδ≤0.0085:Judgment B

[0228] 0.0085<tanδ<0.010:C

[0229] 0.010≤tanδjudgment×

[0230] As described above, the smaller the tan δ, the better the characteristics. The values ​​of 0.010 or more are unacceptable (×). Based on the values, A is good, B is next, and C is the last.

[0231] [Raw materials, etc.]

[0232] The raw materials, catalysts, solvents and solvents used in the following examples and comparative examples are as follows.

[0233] [Epoxy resin (A)]

[0234] (A-1): o-cresol novolac type epoxy resin (epoxy equivalent: 197 g / equivalent, Mn: 416, average number of epoxy groups per molecule: 2.1)

[0235] (A-2): o-cresol novolac type epoxy resin (epoxy equivalent: 220 g / equivalent, Mn: 1018, average number of epoxy groups per molecule: 4.7)

[0236] (A-3): o-cresol novolac type epoxy resin (epoxy equivalent: 219 g / equivalent, Mn: 831, average number of epoxy groups per molecule: 3.8)

[0237] (A-4): Mitsubishi Chemical Corporation, trade name "jER 157S70" (bisphenol A novolac type epoxy resin, epoxy equivalent: 209 g / equivalent, Mn: 500, average number of epoxy groups per molecule: 2.4)

[0238] (A-5): Mitsubishi Chemical Corporation, trade name "jER 1031S" (tetraphenylethane type epoxy resin, epoxy equivalent: 196 g / equivalent, Mn: 666, average number of epoxy groups per molecule: 3.4)

[0239] (A-6): Mitsubishi Chemical Corporation, trade name "jER 154" (phenol novolac type epoxy resin, epoxy equivalent: 178 g / equivalent, Mn: 480, average number of epoxy groups per molecule: 2.7)

[0240] (A-7): Mitsubishi Chemical Corporation, trade name "jER YX7700" (a novolac-type epoxy resin containing a xylenol skeleton, epoxy equivalent: 271 g / equivalent, Mn: 660, average number of epoxy groups per molecule: 2.4)

[0241] (A-8): Mitsubishi Chemical Corporation, trade name "jER 828US" (bisphenol A type epoxy resin, epoxy equivalent: 185 g / equivalent, Mn: 330, average number of epoxy groups per molecule: 1.8)

[0242] [Ester compound (B)]

[0243] (B-1): 2-Naphthyl benzoate (active equivalent: 248 g / equivalent)

[0244] (B-2): Phenyl benzoate (active equivalent: 198 g / equivalent)

[0245] [Diester compound]

[0246] (P-1): Bisphenol A diacetate (active equivalent: 156 g / equivalent)

[0247] [Other ester compounds]

[0248] (P-2): Monomethyl terephthalate

[0249] [catalyst]

[0250] (C-1): 4-(dimethylamino)pyridine

[0251] [solvent, solvent]

[0252] (S-1): Cyclohexanone

[0253] (S-2): Methyl ethyl ketone (MEK)

[0254] [Manufacturing and evaluation of modified epoxy resin]

[0255] <Examples 1-1 to 1-16, Comparative Examples 1-1 to 1-3>

[0256] The epoxy resin, ester compound or diester compound, catalyst and reaction solvent are added to a reaction vessel with a stirrer according to the ratio shown in Table 1 and Table 2, and the reaction is carried out in a nitrogen atmosphere according to the reaction time and reaction temperature recorded in Table 1 and Table 2. Then, a dilution solvent is added to adjust the solid content concentration.

[0257] In Examples 1-14 to 16 and Comparative Example 1-1, no solvent was used for the reaction and no dilution with a solvent was performed, and a solid epoxy resin was finally obtained.

[0258] In Comparative Example 1-3, gelation occurred during the reaction, and no evaluation sample was obtained.

[0259] The analysis results of the obtained modified epoxy resin are shown in Table 1 and Table 2.

[0260]

[0261]

[0262] [Production and evaluation of epoxy resin composition / cured product]

[0263] <Examples 2-1 to 2-13, Comparative Examples 2-1 to 2-2>

[0264] The modified epoxy resins obtained in Examples 1-1 to 1-13 and Comparative Examples 1-1 to 1-2, a 60 wt % cyclohexanone solution of a commercially available polyarylate resin (polyarylate having a bisphenol skeleton) as a curing agent, a 5 wt % toluene solution of 4-(dimethylamino)pyridine (abbreviated as "DMAP") as a curing accelerator, and a high molecular weight epoxy resin (manufactured by Mitsubishi Chemical, trade name "YL7891T30", Mn: 10,000, Mw: 30,000, epoxy equivalent: 6,000 g / equivalent) as other epoxy resins serving as film-forming agents are mixed in the weight ratio shown in Tables 3A and 3B (epoxy equivalent of total epoxy resin: active equivalent of curing agent = 1:1) to obtain an epoxy resin composition. The obtained epoxy resin composition solution was applied onto a separator (silicone-treated polyethylene terephthalate film) using an applicator, dried at 160° C. for 1.5 hours, and then dried at 200° C. for 1.5 hours to obtain a film of a cured epoxy resin.

[0265] The films were evaluated for heat resistance according to the above method. The results are shown in Tables 3A and 3B.

[0266] The dielectric properties were further evaluated in Examples 2-1 to 8 and 11 and Comparative Examples 1-1 and 2. The results are shown in Tables 4A and 4B.

[0267] [Table 3A]

[0268] Table-3A. Raw material ratio and evaluation results of epoxy resin composition

[0269] ※1: The numbers in parentheses in the table indicate the weight parts of solid content.

[0270] [Table 3B]

[0271] Table-3B. Raw material ratio and evaluation results of epoxy resin composition

[0272]

[0273] ※1: The numbers in parentheses in the table indicate the weight parts of solid content.

[0274] [Table 4A]

[0275] Table-4A. Dielectric property evaluation results of epoxy resin cured films

[0276]

[0277] [Table 4B]

[0278] Table-4B. Dielectric property evaluation results of epoxy resin cured films

[0279]

[0280] The results of Tables 3A and 3B show that the epoxy resin cured product film composed of the epoxy resin composition using the modified epoxy resin of the present invention has excellent heat resistance.

[0281] The results of Tables 4A and 4B show that the epoxy resin cured product film composed of the epoxy resin composition using the modified epoxy resin of the present invention is excellent in low dielectric properties.

[0282] These results show that the epoxy resin cured product film composed of the epoxy resin composition using the epoxy resin of the present invention has an excellent balance between heat resistance and low dielectric properties.

[0283] In contrast, the epoxy resin cured product film using the modified epoxy resin of Comparative Example 1-1 was inferior in heat resistance and low dielectric properties. In addition, the epoxy resin cured product film using the modified epoxy resin of Comparative Example 1-2 was inferior in low dielectric properties.

[0284] [Preparation and evaluation of prepreg and laminate]

[0285] The modified epoxy resin synthesized in Example 1-14 was dissolved in methyl ethyl ketone and the resin content was 70% by weight. The prepared epoxy resin solution (solution volume 120g, solid content 84g), a 50% by weight methyl ethyl ketone solution (solution volume 75g, solid content 38g) of a commercially available polyarylate resin (polyarylate with a bisphenol skeleton) as a curing agent, and a 5% by weight toluene solution of 4-(dimethylamino)pyridine as a curing accelerator (solution volume 2.4g, solid part 0.12g) were mixed to prepare an epoxy resin composition (varnish solution). The following substrate was immersed in the obtained varnish solution, and then dried at 160°C for 5 minutes to obtain a prepreg. The obtained prepreg was stacked 6 sheets and cured under the following conditions using a hot press to obtain a laminate.

[0286] Base material: Glass cloth ("#2116" manufactured by Nitto Bosho Co., Ltd.)

[0287] Number of layers: 6

[0288] Pre-preg conditions: 160°C

[0289] Curing conditions: 1.5 hours at 200°C, 2MPa

[0290] Thickness of the plate after forming: 0.8m

[0291] The thermophysical properties of the obtained laminate were measured using DMS (manufactured by Hitachi High-Technologies Corporation) at 1 GHz and 30 to 280°C (heating rate 5°C / min). As a result, tanδ (E" / E') of the elastic modulus was not measured, but the glass transition temperature was measured to be 162°C.

[0292] The dielectric loss tangent (tan δ) of the obtained laminate was measured by a network analyzer using a cavity resonance perturbation method at a measurement frequency of 10 GHz and a measurement temperature of 23° C. The result showed a value of 0.0074.

[0293] From the measurement results, it can be seen that the use of the modified epoxy resin of the present invention can produce a laminated board with excellent heat resistance and low dielectric properties.

[0294] Although the present invention has been described in detail using specific forms, it will be apparent to one skilled in the art that various modifications can be made without departing from the spirit and scope of the invention.

[0295] This application is based on Japanese Patent Application No. 2019-002733 filed on January 10, 2019, the entirety of which is incorporated herein by reference.

[0296] Industrial Applicability

[0297] According to the present invention, a modified epoxy resin having excellent balance between heat resistance and low dielectric properties, an epoxy resin composition containing the modified epoxy resin and a curing agent, and a cured product thereof can be provided. Therefore, the epoxy resin composition and the cured product thereof of the present invention can be applied to various fields such as adhesives, coatings, civil engineering and construction materials, and insulating materials for electrical / electronic components, and are particularly useful as insulating castings, laminating materials, sealing materials, etc. in the electrical / electronic field.

[0298] As an example of the use of the modified epoxy resin of the present invention and the epoxy resin composition containing the same, there can be listed: multilayer printed wiring boards, laminated boards for electric / electronic circuits such as capacitors, adhesives such as film adhesives and liquid adhesives, semiconductor sealing materials, bottom filling materials, inter-chip fillers for 3D-LSI, insulating sheets, prepregs, heat dissipation substrates, etc. However, it is not limited to these.

Claims

1. A modified epoxy resin obtained by reacting an epoxy resin (A) having an average of 2 or more epoxy groups per molecule with an ester compound (B) represented by the following formula (2) or (3), wherein the number of ester structures per molecule of the ester compound (B) is 1, In formulas (2) and (3), R 3 , R 4 , R 5 are each independently a group arbitrarily selected from an alkyl group having 1 to 12 carbon atoms and an aryl group having 6 to 12 carbon atoms, n represents an integer of 0 to 5, and m represents an integer of 0 to 7, The reaction equivalent ratio of the epoxy resin (A) to the ester compound (B) is 1.6 to 6.0, calculated as the ratio of the number of moles of epoxy groups of the epoxy resin (A) to the number of moles of ester groups of the ester compound (B). The modified epoxy resin has a weight average molecular weight Mw in the range of 500 to 10,000, and an epoxy equivalent in the range of 300 to 1,000 g / equivalent.

2. The modified epoxy resin according to claim 1, wherein The ester compound (B) is 2-naphthyl benzoate or phenyl benzoate.

3. The modified epoxy resin according to claim 1, comprising a structure represented by the following formula (4): In formula (4), R 1 is an aryl group which may be substituted; R 2 is an aryl group which may have a substituent; the substituent is a group selected from the group consisting of an alkyl group having 1 to 12 carbon atoms and an aryl group having 6 to 12 carbon atoms. 4 . An epoxy resin composition comprising the modified epoxy resin according to claim 1 and a curing agent.

5. The epoxy resin composition according to claim 4, wherein The epoxy resin composition contains 0.1 to 100 parts by weight of the curing agent in terms of solid content, based on 100 parts by weight of the solid content of the modified epoxy resin. 6 . The epoxy resin composition according to claim 4 , comprising the modified epoxy resin and another epoxy resin, wherein the weight ratio of the solid content of the modified epoxy resin to the other epoxy resin is 99 / 1 to 1 / 99.

7. The epoxy resin composition according to claim 6, wherein The epoxy resin composition contains 0.1 to 100 parts by weight of the curing agent in terms of solid content, based on 100 parts by weight of the total solid content of the modified epoxy resin and other epoxy resins.

8. The epoxy resin composition according to any one of claims 4 to 7, wherein The curing agent is at least one selected from the group consisting of phenolic curing agents, amide curing agents, imidazoles, and active ester curing agents. 9 . A cured product obtained by curing the epoxy resin composition according to claim 4 . 10 . A laminate for electric or electronic circuits, comprising the epoxy resin composition according to claim 4 .

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