TWI853879B - Modified epoxy resin, epoxy resin composition, cured product, and laminate for electrical and electronic circuits - Google Patents

Abstract

A modified epoxy resin is obtained by reacting an epoxy resin (A) having an average of 2 or more epoxy groups in one molecule with an ester compound (B) represented by the following formula (1) having one ester structure in one molecule. ^R1 is an alkyl group which may have a substituent or an aryl group which may have a substituent. ^R2 is an aryl group which may 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

Modified epoxy resin, epoxy resin composition, cured product, and laminate for electrical and electronic circuits

The present invention relates to a modified epoxy resin having excellent heat resistance and low dielectric properties, an epoxy resin composition comprising the modified epoxy resin and a hardener, and a hardened product thereof, and a laminate for electrical and electronic circuits comprising the epoxy resin composition.

Epoxy resin has excellent adhesion, water resistance, mechanical strength and electrical properties, so it is used in various fields such as adhesives, coatings, civil engineering materials, and insulation materials for electrical and electronic parts. Especially in the electrical and electronic fields, it is widely used in insulation casting, laminated materials, sealing materials, etc. In recent years, the development of multi-layer circuit substrates used in electrical and electronic equipment, the miniaturization, lightweight and high-functionality of equipment has required further multi-layering, high density, thinness, lightweight, and improvement of reliability and forming processability.

As an important property required of epoxy resins used as materials for electrical and electronic components such as laminates for electrical and electronic circuits, low dielectric properties can be listed.

In recent years, due to the increase in information transmission volume and speed, the communication frequency has further developed. Among them, the increase in transmission loss (α) has become a major issue. This means that the lower the value of transmission loss (α), the less the attenuation of the information signal, and the higher the reliability of communication can be ensured. α is proportional to the frequency (f), so when α increases in communication in the high-frequency area, the reliability decreases. As a method of suppressing transmission loss (α), a method of reducing the dielectric loss tangent (tanδ) that is proportional to α as well as the frequency (f) can be cited. In order to transmit communication signals at high speed, materials with lower dielectric loss tangent (tanδ) are required, that is, materials with low dielectric properties.

Furthermore, electrical and electronic components such as multilayer boards for electrical and electronic circuits require higher reliability, and in addition to low dielectric properties, they require a balance of various properties such as heat resistance. In particular, with the increase in information transmission in high-frequency areas in recent years, the load imposed on electronics and electronic circuit multilayer boards has also increased, generating internal heat. Therefore, heat resistance in a wider temperature range than before is a necessary characteristic.

Patent document 1 discloses a modified epoxy resin formed by reacting an acetylated polyphenol compound with an epoxy resin, with the aim of providing a cured epoxy resin having low viscosity and low water absorption but excellent heat resistance.

The modified epoxy resin disclosed in Patent Document 1 is specifically an epoxy resin obtained by the reaction of a diacylated phenol compound and a bisphenol-type epoxy resin. Patent Document 1 describes the subject matter of 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.

Furthermore, the results of the inventors' research show that, based on the properties required for electrical and electronic components in recent years, the modified epoxy resin in Patent Document 1 is not sufficient in terms of low dielectric properties (low dielectric loss tangent (low tanδ)) as a material used in high frequency regions.

Patent document 1: Japanese Patent Publication No. 8-333437

The subject of the present invention is to provide a modified epoxy resin with excellent balance of heat resistance and low dielectric properties, an epoxy resin composition comprising the modified epoxy resin and a hardener and its hardened product, and a laminate for electrical and electronic circuits comprising the epoxy resin composition.

The inventors of the present invention have discovered that the above-mentioned problem can be solved by using a specific monofunctional ester compound to modify the epoxy resin to obtain the epoxy resin.

The gist of this invention is as follows [1]~[11].

[1] A modified epoxy resin obtained by reacting an epoxy resin (A) having an average of 2 or more epoxy groups in one molecule with an ester compound (B) represented by the following formula (1) having one ester structure in one molecule.

In formula (1), ^R1 is an alkyl group which may have a substituent or an aryl group which may have a substituent. ^R2 is an aryl group which may 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.

[2] The modified epoxy resin as described in [1], wherein 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 molar number of epoxy groups in the epoxy resin (A) to the molar number of ester groups in the ester compound (B).

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

[4] An epoxy resin composition comprising a modified epoxy resin as described in any one of [1] to [3] and a hardener.

[5] The epoxy resin composition as described in [4], wherein the epoxy resin composition contains 0.1 to 100 parts by weight of the hardener based on solid content relative to 100 parts by weight of the solid content of the modified epoxy resin.

[6] The epoxy resin composition described in [4] or [5], comprising the modified epoxy resin and other epoxy resins, 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 as described in [6], wherein the epoxy resin composition contains 0.1 to 100 parts by weight of the above-mentioned hardener in terms of solid content relative to 100 parts by weight of the total solid content of the above-mentioned modified epoxy resin and other epoxy resins.

[8] The epoxy resin composition as described in any one of [4] to [7], wherein the hardener is at least one selected from the group consisting of phenolic hardeners, amide hardeners, imidazoles and active ester hardeners.

[9] A hardened material obtained by hardening the epoxy resin composition as described in any one of [4] to [8].

[10] A laminate for electrical or electronic circuits, formed using an epoxy resin composition as described in any one of [4] to [8].

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

In formula (4), ^R1 is an alkyl group which may have a substituent or an aryl group which may have a substituent. ^R2 is an aryl group which may 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.

According to the present invention, a modified epoxy resin, epoxy resin composition and cured product thereof with excellent balance of 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 and electronic parts. The modified epoxy resin of the present invention and the epoxy resin composition containing the same are particularly useful as insulating castings, lamination materials, sealing materials, etc. in the electrical and electronic fields.

The modified epoxy resin and the epoxy resin composition containing the same of the present invention can be suitably used in multi-layer printed wiring boards, capacitors and other electrical and electronic circuit laminates, film adhesives, liquid adhesives and other adhesives, semiconductor sealing materials, bottom filling materials, 3D-LSI (Large Scale Integration) chip inter-chip filling, insulating sheets, prepregs, heat dissipation substrates, etc.

The following is a detailed description of the implementation of the present invention.

The following description is an example of the implementation form of the present invention. The present invention is not limited to the following description as long as it does not exceed its gist.

In this manual, when "~" is used in an expression, it is used to express the numerical value or physical property value before and after it.

[Modified epoxy resin]

The modified epoxy resin of the present invention is obtained by reacting an epoxy resin (A) having an average of 2 or more epoxy groups in one molecule with an ester compound (B) represented by the following formula (1) having one ester structure in one molecule.

In formula (1), ^R1 is an alkyl group which may have a substituent or an aryl group which may have a substituent. ^R2 is an aryl group which may 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.

Furthermore, the modified epoxy resin of the present invention comprises a structure represented by the following formula (4).

[Chemistry 4]

In formula (4), ^R1 and ^R2 have the same meanings as in formula (1).

[Mechanism]

The modified epoxy resin of the present invention has a structure in which the ester group of the ester compound (B) and the epoxy group of the epoxy resin (A) are bonded together as represented by the above formula (4), and the low dielectric properties are improved due to this structure.

As the reason, the following is speculated.

As the structure of the ester compound (B), there is one ester group in one molecule, and the structure contains an alkyl group or an aryl group with low polarity. Therefore, the structure of formula (4) formed by the reaction with the epoxy group of the epoxy resin (A) is also low in polarity and exhibits low dielectric properties. In addition, the epoxy group derived from the epoxy resin (A) is appropriately retained in the modified epoxy resin together with the structure of formula (4), thereby also increasing the glass transition temperature (Tg) during curing.

Therefore, it is believed that an epoxy resin and its cured product having an excellent balance between low dielectric properties and heat resistance can be obtained.

[Epoxy resin (A)]

The epoxy resin (A) used in the present invention has an average of 2 or more epoxy groups in one molecule.

As the epoxy resin (A), in order to fully exhibit heat resistance after reacting with the ester compound (B), the epoxy equivalent is preferably 400 g/equivalent or less, more preferably 350 g/equivalent or less, and further preferably 300 g/equivalent or less. From the perspective of fully ensuring the 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 further preferably 150 g/equivalent or more.

In the present invention, "epoxy equivalent" is defined as "the mass of epoxy resin containing 1 equivalent of epoxy groups", which can be measured according to JIS K 7236.

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

The number of epoxy groups in one molecule can be calculated by dividing the number average molecular weight (Mn) measured by gel permeation chromatography (GPC) by the epoxy equivalent. The specific example of the measurement method using GPC is described in the following examples.

The epoxy resin (A) is not particularly limited as long as it has an average of 2 or more epoxy groups in one molecule. As examples thereof, the following epoxy resins can be cited.

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, naphthalene Phenol 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.

The epoxy resins (A) may be used alone or as a mixture of two or more.

Among them, preferred are 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, The dicyclopentadiene type epoxy resin is preferably a phenol novolac type epoxy resin, a bisphenol A type novolac epoxy resin, a cresol novolac type epoxy resin, a phenol aralkyl type epoxy resin, a biphenyl type epoxy resin, a dixylenol type epoxy resin, a triphenylmethane type epoxy resin, a tetraphenylethane type epoxy resin, or a dicyclopentadiene type epoxy resin.

[Ester compound (B)]

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

In formula (1), ^R1 is an alkyl group which may have a substituent or an aryl group which may have a substituent. ^R2 is an aryl group which may 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.

In formula (1), the substituents of R ¹ and R ² do not include self-polymerizing substituents.

The ester structure in the ester compound (B) is a substituent that reacts with the epoxy group. The number of ester structures in one molecule of the ester compound (B) is 1. The ester compound containing two or more ester structures may over-react with the epoxy group of the epoxy resin (A), and the molecular weight of the modified epoxy resin may increase and gelation may occur, so it is difficult to obtain the properties of the modified epoxy resin of the present invention as the target.

Ester compounds with self-polymerizing substituents deteriorate the stability of the compound itself or the modified epoxy resin, and there is also the concern that sufficient curing properties may be difficult to obtain when reacting with a hardener.

Here, "self-polymerizing substituent" refers to those that polymerize at temperatures above room temperature, for example, vinyl or acryl, methacrylic, etc.

R ¹ in the above formula (1) is preferably an alkyl group having 1 to 12 carbon atoms or an aryl group having 5 to 14 carbon atoms. R ² is preferably an aryl group having 5 to 14 carbon atoms.

As the alkyl group with 1 to 12 carbon atoms, there can be listed: methyl, ethyl, propyl, isopropyl, butyl, isobutyl, sec-butyl, tert-butyl, pentyl, cyclohexyl, cyclohexyl, heptyl, octyl, nonyl, decyl, dodecyl, cyclododecyl, etc. These may have the following substituents.

As the aromatic group having 5 to 14 carbon atoms, there can be listed: phenyl, biphenyl, naphthyl, amine benzyl, etc. These may have the following substituents.

As R ¹ and R ² in the above formula (1), an aryl group having 5 to 14 carbon atoms is more preferred from the viewpoint of maintaining good reactivity with an epoxide group, heat resistance, and low dielectric loss tangent. Examples of the aryl group having 5 to 14 carbon atoms include phenyl, biphenyl, naphthyl, oxadiazine, and the like. These may have the following substituents.

The alkyl or aryl group of ^R1 and the aryl group of ^R2 may have a substituent 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. The substituent does not impart self-polymerization to ^R1 and ^R2 .

Examples of alkyl groups with 1 to 12 carbon atoms as substituents include methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, t-butyl, n-pentyl, isopentyl, neopentyl, t-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, 2-phenylisopropyl, etc.

Examples of alkoxy groups having 1 to 12 carbon atoms as substituents include methoxy, ethoxy, n-propoxy, isopropoxy, n-butoxy, sec-butoxy, t-butoxy, n-pentoxy, isopentoxy, neopentoxy, t-pentoxy, cyclopentoxy, n-hexoxy, isohexoxy, cyclohexoxy, n-heptyloxy, cycloheptyloxy, methylcyclohexyloxy, n-octyloxy, cyclooctyloxy, n-nonyloxy, 3,3,5-trimethylcyclohexyloxy, n-decyloxy, cyclodecyloxy, n-undecyloxy, n-dodecyloxy, cyclododecyloxy, benzyloxy, methylbenzyloxy, dimethylbenzyloxy, trimethylbenzyloxy, naphthylmethoxy, phenethyloxy, and 2-phenylisopropoxy.

Examples of aromatic groups with 6 to 12 carbon atoms as substituents include phenyl, o-tolyl, m-tolyl, p-tolyl, ethylphenyl, styryl, xylyl, n-propylphenyl, isopropylphenyl, 2,4,6-trimethylphenyl, ethynylphenyl, naphthyl, and vinylnaphthyl.

Among the above, the substituents that may be present in ^R1 and ^R2 are preferably alkyl groups having 1 to 4 carbon atoms, halogen atoms, etc., and more preferably methyl groups. It is particularly preferred that ^R1 and ^R2 have no substituents or have methyl groups as substituents. The reason for this is that if the substituents are too large in terms of stereochemistry, there is a possibility that the aggregation between molecules is hindered, and the heat resistance is reduced.

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

In formulae (2) and (3), R ³ , R ⁴ and R ⁵ are independently any group 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.

Specific examples and preferred substituents of R ³ , R ⁴ and R ⁵ are the same as those described above as substituents that may be possessed by the alkyl or aryl group of R ¹ and the aryl group of R ² .

The naphthyl ring of 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.

n is an integer between 0 and 5, preferably between 0 and 2, more preferably between 0 and 1, and most preferably 0.

m is an integer between 0 and 7, preferably between 0 and 3, more preferably between 0 and 1, and most preferably 0.

The ester compounds (B) may be used alone or in the form of a mixture of two or more.

[Chemical structure of modified epoxy resin]

The modified epoxy resin of the present invention includes a structure represented by the following formula (4), which can be obtained by reacting the epoxy group of the above-mentioned epoxy resin (A) with the ester group of the above-mentioned 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.

In formula (4), ^R1 and ^R2 have the same meanings as in formula (1).

[Weight average molecular weight (Mw)]

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. If the Mw is 500 or more, there is no risk of deterioration of 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 preferably 600 or more, further preferably 700 or more, and particularly preferably 1,000 or more. From the perspective of properly maintaining the resin viscosity and softening point to improve operability, 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.

Mw can be measured by gel permeation chromatography (GPC). The specific example of the measurement method using GPC is described in the following examples.

[Epoxide equivalent]

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

[Softening point]

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 perspective of inhibiting the agglomeration of the resin, the softening point of the modified epoxy resin of the present invention is preferably above 65°C, further preferably above 70°C, and particularly preferably above 75°C. In order to fully ensure the solubility of the solvent, the softening point of the modified epoxy resin of the present invention is preferably below 125°C, further preferably below 120°C, and particularly preferably below 115°C.

Here, the softening point can be measured according to JIS K7234.

Agglomeration refers to the phenomenon that the resin flakes of the powder partially melt and form lumps during storage, which damages the operability.

[Manufacturing method of modified epoxy resin]

The modified epoxy resin of the present invention is obtained by reacting the epoxy resin (A) having an average of 2 or more epoxy groups in one molecule with the ester compound (B) represented by the above formula (1) having one ester structure in one molecule.

As a method for preparing epoxy resin (A), for example, a method of condensing a bisphenol compound or various novolac compounds with epihalogen alcohol by a known method can be cited. As a method for preparing 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 then subjecting the allyl group to an oxidation reaction can be cited. Commercially available epoxy resins (A) can be used.

The ester compound (B) can be produced, for example, by esterifying an alcohol compound or a phenol compound through a condensation reaction with an acyl chloride or a carboxylic acid.

In the production of the modified epoxy resin of the present invention, the reaction equivalent ratio of the epoxy resin (A) to the ester compound (B) is preferably 1.6 to 6.0, as measured by the ratio of the molar number of epoxy groups of the epoxy resin (A) to the molar number of ester groups of the ester compound (B) (hereinafter, sometimes referred to as "molar ratio (epoxy groups/ester groups)"). If the molar ratio (epoxy groups/ester groups) is within the above range, the amount of epoxy groups after the modification reaction can be kept at an optimal level, and balanced characteristics 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 groups/ester groups) is more preferably 1.62 or more, further preferably 1.63 or more, and particularly preferably 1.65 or more. From the same point of view, the molar ratio (epoxy group/ester group) is preferably 5.5 or less, further preferably 5.0 or less, and particularly preferably 4.5 or less.

The modified epoxy resin of the present invention can be produced using a catalyst. As a catalyst, any compound can be used as long as it has a catalytic ability to promote the reaction between epoxy groups and ester groups. Examples of catalysts include tertiary amines, cyclic amines, imidazoles, organic phosphorus compounds, quaternary ammonium salts, etc.

Specific examples of tertiary amines include: triethylamine, tri-n-propylamine, tri-n-butylamine, triethanolamine, benzyldimethylamine, pyridine, 4-(dimethylamino)pyridine, etc.

Specific examples of cyclic amines include: 1,4-diazabicyclo[2,2,2]octane, 1,8-diazabicyclo[5,4,0]undecene-7,1,5-diazabicyclo[4,3,0]nonene-5, etc.

Specific examples of imidazoles include: 2-methylimidazole, 2-ethyl-4-methylimidazole, 2-phenylimidazole, etc.

Specific examples of organophosphorus compounds 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, triphenylbenzylphosphonium bromide, etc.

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

Such catalysts may be used alone or in combination of two or more.

The amount of catalyst used is usually 0.001~1% by weight in the reaction solid component. When a catalyst is used, the catalyst compound in the obtained modified epoxy resin acts as a catalyst Residues remain, and when used in printed wiring boards, there is a risk of deteriorating the insulation properties or shortening the applicable period of the composition.

Therefore, the nitrogen content of the catalyst in the obtained modified epoxy resin is preferably less than 2000ppm, and the phosphorus content is preferably less than 2000ppm. It is more preferred that the nitrogen content in the modified epoxy resin is less than 1000ppm, and the phosphorus content is less than 1000ppm. It is further preferred that the nitrogen content in the modified epoxy resin is less than 500ppm, and the phosphorus content is less than 500ppm. It is particularly preferred that the nitrogen content in the modified epoxy resin is less than 200ppm, and the phosphorus content is less than 200ppm. There is no special limit on the lower limit of the nitrogen and phosphorus content derived from the catalyst, and the lower limit of the detection limit of the distance measurement equipment is about 1ppm.

The modified epoxy resin of the present invention can also use a reaction solvent in the synthesis reaction step during its production. As a solvent, any solvent can be used as long as it can dissolve the epoxy resin. Examples of solvents include aromatic solvents, ketone solvents, amide solvents, glycol ether solvents, etc. Such solvents can be used alone or in combination of two or more.

Specific examples of aromatic solvents include benzene, toluene, xylene, etc.

烷等。 Specific examples of ketone solvents include acetone, methyl ethyl ketone (MEK), methyl isobutyl ketone, 2-heptanone, 4-heptanone, 2-octanone, cyclohexanone, acetylacetone, dimethicone,

Alkane, etc.

Specific examples of amide solvents include: formamide, N-methylformamide, N,N-dimethylformamide, acetamide, N-methylacetamide, N,N-dimethylacetamide, 2-pyrrolidone, N-methylpyrrolidone, etc.

Specific examples of glycol ether solvents 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, propylene glycol monomethyl ether acetate, etc.

When using a solvent in the production of modified epoxy resin, it is preferred to use it in a manner such that the solid content concentration of the reaction system is 35-95% by weight.

When a highly viscous product is produced during the reaction, additional solvent can be added to continue the reaction.

After the reaction is over, the solvent can be removed or added as needed.

In the production of the modified epoxy resin of the present invention, the reaction between the epoxy resin (A) and the ester compound (B) is carried out at a reaction temperature at which the catalyst used does not decompose. If the reaction temperature is too high, there is a risk that the catalyst decomposes and stops the reaction, or the generated modified epoxy resin deteriorates. On the contrary, if the temperature is too low, there is a risk that the reaction does not proceed fully.

For these reasons, the reaction temperature is preferably 50~200℃, more preferably 100~180℃, and further preferably 120℃~160℃.

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

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

[Epoxy resin composition]

The epoxy resin composition of the present invention is an epoxy resin composition comprising at least the modified epoxy resin of the present invention and a hardener. The epoxy resin composition of the present invention is preferably an epoxy resin composition comprising the structure of the above formula (4).

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 with excellent heat resistance and low dielectric properties and fully meet the various physical properties required for various uses.

[Hardener]

In the present invention, the hardener refers to a substance that facilitates the cross-linking reaction and/or chain extension reaction between epoxy groups of the epoxy resin.

In the present invention, even if it is generally called a "hardening accelerator", as long as it is a substance that helps the cross-linking reaction and/or chain extension reaction between epoxy groups of epoxy resin, it is regarded as a hardener.

The content of the hardener 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, relative to 100 parts by weight of the solid content of the modified epoxy resin of the present invention.

When the epoxy resin composition of the present invention contains the following other epoxy resins, the weight ratio of the solid content of the modified epoxy resin of the present invention and other epoxy resins is preferably 99/1~1/99.

In this case, the content of the hardener 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, relative to 100 parts by weight of the total solid content of the modified epoxy resin of the present invention and other epoxy resins.

In the present invention, "solid components" refer to components other than solvents, including not only solid epoxy resins but also semi-solid or viscous liquids.

"Total epoxy resin component" means the total of the modified epoxy resin of the present invention and the other epoxy resins described below.

There is no particular limitation on the hardener used in the epoxy resin composition of the present invention, and all hardeners commonly known as epoxy resin hardeners can be used. From the perspective of improving heat resistance, the preferred hardeners include phenolic hardeners, amide hardeners, imidazoles, and active ester hardeners. The following lists examples of phenolic hardeners, amide hardeners, imidazoles, active ester hardeners, and other hardeners that can be used.

[Phenolic hardener]

From the perspective of improving the workability 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.

Specific examples of phenolic curing agents 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'-dihydroxydiphenyl ketone, 4,4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl ether ... Hydroxybiphenyl, 2,2'-dihydroxybiphenyl, 10-(2,5-dihydroxyphenyl)-10H-9-oxo-10-phosphophenanthrene-10-oxide, phenol novolac, bisphenol A novolac, o-cresol novolac, m-cresol novolac, p-cresol novolac, xylenol novolac, poly(p-hydroxystyrene), hydroquinone, resorcinol, o-catechol, Tributylcatechol, tert-butylhydroquinone, phloroglucinol, ophthalmol, tert-butyl ophthalmol, allylated ophthalmol, polyallylated ophthalmol, 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, allyl or polyallyl compounds of the above dihydroxynaphthalenes, allylated bisphenol A, allylated bisphenol F, allylated phenol novolac, allylated o-pyrogallol, etc.

The phenolic hardeners listed above may be used alone or in any combination and ratio.

When the hardener is a phenolic hardener, it is preferred to use the hardener in a range of 0.8 to 1.5 in terms of the equivalent ratio of the functional group in the hardener to the epoxy group in the epoxy resin composition. If it is within this range, it is difficult to leave unreacted epoxy groups or functional groups of the hardener, so it is preferred.

[Amide hardener]

From the viewpoint of improving the heat resistance of the obtained epoxy resin composition, it is preferable to use an amide hardener as the hardener.

As amide-based hardeners, there are: cyanamide and its derivatives, polyamide resins, etc.

The amide hardeners listed above may be used alone or in any combination and ratio.

The amide hardener is preferably used in an amount of 0.1 to 20% by weight relative to the total amount of the epoxy resin component and the amide hardener as the solid components in the epoxy resin composition.

[Imidazoles]

From the perspective of fully carrying out the curing reaction and improving heat resistance, it is better to use imidazoles as a curing agent.

、2,4-二胺基-6-[2'-乙基-4'-甲基咪唑基-(1')]-乙基-均三

、2,4-二胺基-6-[2'-甲基咪唑基-(1')]-乙基-均三

異三聚氰酸加成體、2-苯基咪唑異三聚氰酸加成體、2-苯基-4,5-二羥基甲基咪唑、2-苯基-4-甲基-5-羥基甲基咪唑、及環氧樹脂與上述咪唑類之加成體等。 Examples of the 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)-6-[2'-methylimidazolyl-(1')]-ethyl-tri ...

, 2,4-diamino-6-[2'-ethyl-4'-methylimidazolyl-(1')]-ethyl-s-triazine

, 2,4-diamino-6-[2'-methylimidazolyl-(1')]-ethyl-s-trimethoxy-

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, etc.

Imidazoles have catalytic properties and can therefore usually be classified as the following hardening accelerators, but are classified as hardeners in the present invention.

The above-listed imidazoles may be used alone or in any combination and ratio of two or more.

Imidazoles are preferably used in an amount of 0.1 to 20% by weight relative to the total amount of the total epoxy resin component and imidazoles as the solid components in the epoxy resin composition.

[Active ester hardener]

From the perspective of low water absorption and low dielectric properties of the obtained cured product, it is better to use an active ester hardener as the hardener.

As active ester curing agents, preferred are compounds having two or more highly reactive ester groups in one molecule, such as phenol esters, thiophenol esters, N-hydroxylamine esters, and esters of heterocyclic hydroxyl compounds. More preferred are phenol esters obtained by reacting a carboxylic acid compound with an aromatic compound having a phenolic hydroxyl group. Specific examples of carboxylic acid compounds include benzoic acid, acetic acid, succinic acid, maleic acid, itaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and pyromellitic acid. As aromatic compounds having phenolic hydroxyl groups, there are: o-catechol, 1,5-dihydroxynaphthalene, 1,6-dihydroxynaphthalene, 2,6-dihydroxynaphthalene, dihydroxybenzophenone, trihydroxybenzophenone, tetrahydroxybenzophenone, phloroglucinol, benzenetriol, dicyclopentadienyl diphenol, phenolic novolac, etc. Polyarylates can also be used as similar hardeners.

As commercially available active ester hardeners, there are: HPC-8000-65T (active ester hardener containing a dicyclopentadiene structure), HPC-8150-60T (active ester hardener containing a naphthalene structure as the main skeleton) (each manufactured by DIC Co., Ltd.).

The above-listed active ester hardeners may be used alone or in any combination and ratio of two or more.

The active ester hardener is preferably used in a range of 0.2 to 2.0 in terms of the equivalent ratio of the active ester group in the hardener to the epoxy group in the all-epoxy resin in the epoxy resin composition.

[Other hardeners]

As other hardeners other than the above that can be used in the epoxy resin composition of the present invention, for example, there can be listed: amine hardeners (except tertiary amines), acid anhydride hardeners, tertiary amines, organic phosphines, phosphonium salts, tetraphenyl boron salts, organic acid dihydrazides, boron halide amine complexes, polythiol hardeners, isocyanate hardeners, blocked isocyanate hardeners, etc.

The other hardeners listed above may be used alone or in any combination and ratio of two or more.

[Other epoxy resins]

The epoxy resin composition of the present invention may contain other epoxy resins in addition to the modified epoxy resin of the present invention. By using other epoxy resins, insufficient physical properties can be compensated or various physical properties can be improved.

As other epoxy resins, those 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, etc. can be used.

Only one of these may be used, or a mixture of two or more may be used.

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 blended in 100% by weight of the total epoxy resin component as a 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, further preferably 90% by weight or less. By making the ratio of other epoxy resins above the lower limit, the effect of improving physical properties by blending other epoxy resins can be fully obtained. By keeping the ratio of other epoxy resins below the above upper limit, the effect of the modified epoxy resin of the present invention can be fully exerted, which is better from the perspective of obtaining the effect of improving physical properties such as low hygroscopicity.

[Solvent]

In order to properly 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 to dilute it.

In the epoxy resin composition of the present invention, the solvent is used to ensure the operability and workability of the epoxy resin composition during molding, and there is no special restriction on its usage amount.

In the present invention, the term "solvent" is used differently from the term "solvent" mentioned above according to their usage forms, but they can be used independently of each other as the same type or as different types.

Examples of solvents that can be included 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, etc.

The above-listed solvents may be used alone or in any combination and ratio of two or more.

[Other ingredients]

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 (except those included in "curing agents"), ultraviolet inhibitors, antioxidants, coupling agents, plasticizers, fluxes, flame retardants, colorants, dispersants, emulsifiers, low-elasticity agents, diluents, defoaming agents, ion scavengers, inorganic fillers, organic fillers, etc.

[Hardened material]

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 having the structure of the above formula (4).

The "hardening" mentioned here means to intentionally harden the epoxy resin composition by heat and/or light, and the degree of hardening can be controlled according to the required physical properties and application. The degree of hardening can be complete hardening or semi-hardening, and there is no special restriction. Usually, the reaction rate of the hardening reaction between epoxy group and hardener is 5~95%.

The curing method of the epoxy resin composition of the present invention when curing the epoxy resin composition to form a cured product also varies depending on the ingredients or amounts in the epoxy resin composition, but generally, the conditions of heating at 80-280°C for 60-360 minutes can be listed. The heating is preferably performed in two stages, and the two stages are divided into a primary heating at 80-160°C for 10-90 minutes and a secondary heating at 120-200°C for 60-150 minutes. It is preferred to further perform a third heating at 150-280°C for 60-120 minutes in a system where the glass transition temperature (Tg) exceeds the temperature of the secondary heating. From the perspective of reducing poor hardening or solvent residue, it is better to perform secondary or tertiary heating.

When making a semi-cured resin, it is preferred to heat the epoxy resin composition to cure until the shape can be maintained. When the epoxy resin composition contains a solvent, most of the solvent is usually removed by heating, decompression, air drying, etc. Less than 5% by weight of the solvent may remain in the semi-cured resin.

[Purpose]

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 exerts the effect of providing a cured product with excellent heat resistance and low dielectric properties. Therefore, the modified epoxy resin of the present invention and the epoxy resin composition containing it can be used in various fields such as adhesives, coatings, civil engineering materials, and insulating materials for electrical and electronic parts, and is particularly useful as insulating castings, lamination materials, and sealing materials in the electrical and electronic fields.

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: multi-layer printed wiring substrates, capacitors and other electrical, electronic circuit laminates, film adhesives, liquid adhesives and other adhesives, semiconductor sealing materials, bottom filling materials, 3D-LSI chip filling, 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 any of the above.

[Multilayer boards for electrical and electronic circuits]

As described above, the epoxy resin composition of the present invention can be suitably used for laminated boards for electrical and electronic circuits. In the present invention, "laminated boards for electrical and electronic circuits" refers to laminated boards comprising layers of the epoxy resin composition of the present invention and conductive metal layers. If the laminated boards are laminated boards comprising layers of the epoxy resin composition of the present invention and conductive metal layers, the concept of using them as capacitors is included even if they are not electrical and electronic circuits.

A layer containing two or more epoxy resin compositions can be formed in a laminate for electrical or electronic circuits, and the epoxy resin composition of the present invention can be used in at least one layer. Two or more conductive metal layers can also be formed in a laminate for electrical or electronic circuits.

The thickness of the layer containing epoxy resin composition in the laminate for electrical and electronic circuits is usually about 10~200μm. The thickness of the conductive metal layer is usually about 0.2~70μm.

[Conductive metals]

Conductive metals used in laminates for electrical and electronic circuits include copper, aluminum and other metals or alloys containing these metals. In the conductive metal layer of laminates for electrical and electronic circuits, metal foils of these metals or metal layers formed by plating or sputtering can be used.

[Manufacturing method of laminated board for electrical and electronic circuits]

As a method for manufacturing a multilayer board for electrical and electronic circuits in the present invention, for example, the following method can be cited.

(1) Non-woven fabrics or fabrics made of inorganic and/or organic fiber materials such as glass fiber, polyester fiber, aromatic polyamide fiber, cellulose, nanofiber fiber, etc. are impregnated with the epoxy resin composition of the present invention to form a prepreg, and then a conductive metal foil and/or a conductive metal layer are provided by plating, and a circuit is formed using a photoresist, etc., and the necessary number of layers are stacked to form a laminate.

(2) The prepreg of (1) above is used as the core material, and a layer containing an epoxy resin composition and a conductive metal layer are stacked thereon (on one side or both sides) (stacking method). The layer containing the epoxy resin composition may also contain organic and/or inorganic fillers.

(3) Without using core material, layers containing epoxy resin compositions and conductive metal layers are alternately laminated to form laminated boards for electrical and electronic circuits.

Implementation example

The present invention is described in more detail below based on the embodiments, but the present invention is not limited to the following embodiments.

The values of various manufacturing conditions or evaluation results in the following embodiments have the meaning of the preferred values of the upper or lower limits of the embodiments of the present invention. The preferred range may be the range specified by the combination of the above-mentioned upper or lower limit values and the values of the following embodiments or the values of the embodiments themselves.

[Evaluation methods of physical properties and characteristics]

In the following embodiments and comparative examples, the evaluation of physical properties and characteristics is carried out by the methods described in 1) to 6) below.

1) Weight average molecular weight (Mw) and number average molecular weight (Mn)

The TSK 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) are used as the calibration curve of standard polystyrene, and the weight average molecular weight (Mw) and number average molecular weight (Mn) are measured as polystyrene conversion values.

Column: "TSKGEL SuperHM-H+H5000+H4000+H3000+H2000" manufactured by Tosoh Corporation

Solvent: Tetrahydrofuran

Flow rate: 0.5ml/min

Detection: UV (Ultraviolet) (wavelength 254nm)

Temperature: 40℃

Sample concentration: 0.1 wt%

Injection volume: 10μl

2) The average number of epoxy groups in one molecule of the raw material epoxy resin

Calculated as the value obtained by dividing the number average molecular weight obtained by GPC measurement by the epoxy equivalent.

3) Epoxy equivalent

Measured in accordance with JIS K7236, in the case of solution, indicated as solid content conversion value.

4) Softening point

Determine the softening point of solid epoxy resin according to JIS K7234.

5) Heat resistance of hardened material: glass transition temperature (Tg, DSC (Differential scanning calorimetry))

For the epoxy resin cured film with a thickness of about 50μm obtained by drying and curing the epoxy resin composition solution, the glass transition temperature was measured by using "DSC7020" manufactured by SII NanoTechnology Co., Ltd., heating to 30~250℃ at 10℃/min.

The glass transition temperature described here is based on the "Midpoint glass transition temperature: Tmg" measurement stated in JIS K7121 "Determination of transition temperature of plastics".

The criteria for determining the glass transition temperature are as follows.

Tg 120℃ or above: judged as ◎

Tg 100℃ or higher and less than 120℃: judged as ○

Tg less than 100℃: judged as ×

6) Dielectric properties

Cut the epoxy resin cured film or the prepared prepreg into a test piece with a width of 2mm and a length of 80mm. Use a network analyzer to measure the dielectric loss tangent (tanδ) of the test piece using the cavity resonance perturbation method at a measurement frequency of 10GHz and a measurement temperature of 23℃.

The criteria for determining dielectric properties are as follows.

tanδ≦0.0075: Judgement A

0.0075<tanδ≦0.0085: Judgement B

0.0085<tanδ<0.010: Judgement C

0.010≦tanδ: judgment ×

As mentioned above, the smaller the tanδ, the better the characteristics. 0.010 or more is considered unqualified (×). Based on the values, the good one is A, followed by B, and finally C.

[Raw materials, etc.]

The raw materials, catalysts, solvents and solvents used in the following embodiments and comparative examples are described below.

[Epoxy resin (A)]

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

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

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

(A-4): Manufactured by Mitsubishi Chemical Co., Ltd., trade name "jER 157S70" (bisphenol A novolac type epoxy resin, epoxy equivalent: 209 g/equivalent, Mn: 500, average number of epoxy groups in one molecule: 2.4)

(A-5): Manufactured by Mitsubishi Chemical Co., Ltd., trade name "jER 1031S" (tetraphenylethane type epoxy resin, epoxy equivalent: 196g/equivalent, Mn: 666, average number of epoxy groups in one molecule: 3.4)

(A-6): Manufactured by Mitsubishi Chemical Co., Ltd., trade name "jER 154" (phenolic novolac type epoxy resin, epoxy equivalent: 178g/equivalent, Mn: 480, average number of epoxy groups in one molecule: 2.7)

(A-7): Manufactured by Mitsubishi Chemical Co., Ltd., trade name "jER YX7700" (phenolic varnish type epoxy resin containing a xylenol skeleton, epoxy equivalent: 271g/equivalent, Mn: 660, average number of epoxy groups in one molecule: 2.4)

(A-8): Manufactured by Mitsubishi Chemical Co., Ltd., trade name "jER 828US" (bisphenol A type epoxy resin, epoxy equivalent: 185g/equivalent, Mn: 330, average number of epoxy groups in one molecule: 1.8)

[Ester compound (B)]

(B-1): 2-naphthyl benzoate (active equivalent: 248 g/equivalent)

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

[Diester compounds]

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

[Other ester compounds]

(P-2): Monomethyl terephthalate

[Tactile Media]

(C-1): 4-(dimethylamino)pyridine

[Solvent, solvent]

(S-1): Cyclohexanone

(S-2): Methyl ethyl ketone (MEK)

[Manufacturing and evaluation of modified epoxy resin]

<Implementation Examples 1-1~1-16, Comparative Examples 1-1~1-3>

Add epoxy resin, ester compound or diester compound, catalyst and reaction solvent in the mixture shown in Table-1 and Table-2 to a reaction container with a stirrer, and react under nitrogen atmosphere at the reaction time and reaction temperature shown in Table-1 and Table-2. Then, add dilution solvent to adjust the solid content concentration.

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

Comparative Example 1-3 gelled during the reaction and no evaluation sample could be obtained.

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

[Manufacturing and evaluation of epoxy resin compositions/cured products]

<Implementation Examples 2-1~2-13, Comparative Examples 2-1~2-2>

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 (Mitsubishi Chemical, trade name "YL7891T30", Mn: 10,000, Mw: 30,000, epoxy equivalent: 6,000 g/equivalent) were mixed to obtain an epoxy resin composition. The obtained epoxy resin composition solution was applied to a separator (polyethylene terephthalate film treated with polysilicone) by 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 epoxy resin cured product.

Regarding them, the heat resistance was evaluated according to the above method. The results are shown in Tables 3A and 3B.

In Examples 2-1 to 8, 11 and Comparative Examples 1-1 and 2, the dielectric properties are further evaluated. The results are shown in Tables 4A and 4B.

[Table 4A]

According to the results of Tables 3A and 3B, the epoxy resin cured product film containing the epoxy resin composition using the modified epoxy resin of the present invention has excellent heat resistance.

According to the results of Tables 4A and 4B, the epoxy resin cured product film containing the epoxy resin composition using the modified epoxy resin of the present invention has excellent low dielectric properties.

According to these results, it can be seen that the epoxy resin cured product film including the epoxy resin composition using the epoxy resin of the present invention has an excellent balance between heat resistance and low dielectric properties.

In contrast, the heat resistance and low dielectric properties of the epoxy resin cured product using the modified epoxy resin of Comparative Example 1-1 are poor. In addition, the low dielectric properties of the epoxy resin cured product using the modified epoxy resin of Comparative Example 1-2 are poor.

[Manufacturing and evaluation of prepreg and laminates]

The modified epoxy resin synthesized in Example 1-14 was dissolved in methyl ethyl ketone so that the resin content was 70 wt%. The prepared epoxy resin solution (solution volume 120 g, solid content 84 g), a 50 wt% methyl ethyl ketone solution (solution volume 75 g, solid content 38 g) of a commercially available polyarylate resin (polyarylate having a bisphenol skeleton) as a curing agent, and a 5 wt% toluene solution (solution volume 2.4 g, solid content 0.12 g) of 4-(dimethylamino)pyridine as a curing accelerator were mixed to form an epoxy resin composition (varnish solution). The obtained varnish solution was impregnated into the following substrate and dried at 160°C for 5 minutes to obtain a prepreg. The prepreg obtained by laminating 6 sheets was hardened using a hot press under the following conditions to obtain a laminated board.

Base material: Glass cloth ("#2116" manufactured by Nitto Textile Co., Ltd.)

Required number of sheets: 6

Prepreg conditions: 160℃

Hardening conditions: 200℃, 2MPa for 1.5 hours

Plate thickness after forming: 0.8m

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

For the obtained laminate, the dielectric loss tangent (tanδ) was measured using a network analyzer and the 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.

According to the test results, by using the modified epoxy resin of the present invention, even when making a laminate, it also exhibits excellent heat resistance and low dielectric properties.

The present invention is described in detail using specific aspects, but it is clear to the industry that various changes can be made without departing from the intent and scope of the present invention.

This application is based on Japanese Patent Application No. 2019-002733 filed on January 10, 2019, the entirety of which is cited by reference.

[Industrial availability]

According to the present invention, a modified epoxy resin having excellent balance between heat resistance and low dielectric properties, an epoxy resin composition comprising the modified epoxy resin and a hardener, and a hardened product thereof can be provided. Therefore, the epoxy resin composition and hardened product thereof of the present invention can be applied to various fields such as adhesives, coatings, civil engineering materials, and insulating materials for electrical and electronic parts, and are particularly useful as insulating castings, laminating materials, and sealing materials in the electrical and electronic fields.

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: multi-layer printed wiring boards, electrical and electronic circuit laminates such as capacitors, film adhesives, liquid adhesives and other adhesives, semiconductor sealing materials, bottom filling materials, 3D-LSI chip filling, insulating sheets, prepregs, heat dissipation substrates, etc. However, it is not limited to any of the above.

Claims (11)

A modified epoxy resin obtained by reacting an epoxy resin (A) having an average of 2 or more epoxy groups in one molecule with an ester compound (B) represented by the following formula (1) having one ester structure in one molecule;

In formula (1), ^R1 is an alkyl group which may have a substituent or an aryl group which may have a substituent; ^R2 is an aryl group which may have a substituent; and 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. The modified epoxy resin of claim 1, wherein 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 molar number of the epoxy group of the epoxy resin (A) to the molar number of the ester group of the ester compound (B). The modified epoxy resin of claim 1 or 2, wherein R ¹ and R ² in the above formula (1) are independently phenyl which may have a substituent or naphthyl which may have a substituent. An epoxy resin composition comprising a modified epoxy resin as claimed in any one of claims 1 to 3 and a hardener. The epoxy resin composition of claim 4, wherein the epoxy resin composition contains 0.1 to 100 parts by weight of the hardener in terms of solid content relative to 100 parts by weight of the solid content of the modified epoxy resin. The epoxy resin composition of claim 4 or 5 comprises the modified epoxy resin and other epoxy resins, and the weight ratio of the solid content of the modified epoxy resin to the other epoxy resin is 99/1~1/99. The epoxy resin composition of claim 6, wherein the epoxy resin composition contains 0.1 to 100 parts by weight of the above-mentioned hardener in terms of solid content relative to 100 parts by weight of the total solid content of the above-mentioned modified epoxy resin and other epoxy resins. The epoxy resin composition of any one of claims 4 to 7, wherein the hardener is at least one selected from the group consisting of phenolic hardeners, amide hardeners, imidazoles and active ester hardeners. A hardener obtained by hardening the epoxy resin composition as described in any one of claims 4 to 8. A laminate for electrical and electronic circuits, formed using an epoxy resin composition as described in any one of claims 4 to 8. A modified epoxy resin comprising a structure represented by the following formula (4):

In formula (4), ^R1 is an alkyl group which may have a substituent or an aryl group which may have a substituent, and ^R2 is an aryl group which may have a substituent, wherein 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.