TW202026326A - Epoxy resin, epoxy resin composition and resin-cured product having excellent handling properties as a solid at room temperature, a low viscosity during molding and an excellent solvent solubility - Google Patents

Abstract

To provide a crystalline modified-epoxy resin which is excellent in handleability as a solid at room temperature, has low viscosity at the time of molding, and is excellent in solvent solubility, and an epoxy resin composition using the same, and a resin-cured product obtain from the same and having a high thermal conductivity. An epoxy resin, which is represented by the following general formula (1), and characterized in that the sum of n=0 bodies is 90 wt% or less, and a compound of n=1 body or more are from 5 wt% to 35 wt%: (In the formula, G represents a glycidyl group, wherein the glycidyl ether group bonded to a biphenyl ring is a 4,4' bond or a 2,2' bond, and n represents a number of 0 to 10).

Description

Epoxy resin, epoxy resin composition and resin cured product

The present invention relates to an insulating material for electrical/electronic parts such as semiconductor seals, laminates, and heat dissipation substrates with excellent reliability, excellent handling as a solid at room temperature, and low viscosity and solvent during molding. An epoxy resin having excellent solubility, an epoxy resin composition using the same, and a cured product having excellent high thermal conductivity obtained therefrom.

Epoxy resin has been used in a wide range of industrial applications, but in recent years, its required performance has gradually become higher. In the electrical/electronic fields and power electronics fields where the density and high frequency of electronic circuits are advancing, the heat generated from the electronic circuits increases, so the epoxy resin composition is used for the heat dissipation of the insulating part Sex becomes a problem. Regarding the heat dissipation, conventionally, the thermal conductivity of the filler has been used to deal with it. However, for further high integration, it is required to improve the thermal conductivity of the epoxy resin itself as the matrix.

As an epoxy resin composition with high thermal conductivity, it is known that an epoxy resin having a mesogen structure is used. For example, Patent Document 1 shows that a biphenol type epoxy resin and a polyphenol resin curing agent are used as essential components. The epoxy resin composition disclosed that it has excellent stability and strength at high temperatures, and can be used in a wide range of fields such as bonding, casting, sealing, molding, and lamination. Furthermore, Patent Document 2 discloses an epoxy compound having two mesogen structures connected by a curved chain in the molecule. Furthermore, Patent Document 3 discloses a resin composition containing an epoxy compound having a mesogen group.

However, the epoxy resin having such a mesogen structure has a high melting point, and in the case of a mixing process, the high melting point component is difficult to dissolve, and a dissolution residue is generated. Therefore, there is a problem of a decrease in curability or heat resistance. Moreover, high temperature is required to uniformly mix such epoxy resin and hardener. At high temperatures, the hardening reaction of the epoxy resin progresses rapidly and the gelation time becomes shorter. Therefore, there is a problem that the mixing process is severely restricted and difficult to handle. In addition, if a soluble third component is added in order to compensate for this disadvantage, the melting point of the resin decreases and uniform mixing becomes easy, but the hardened product causes a problem of decreased thermal conductivity.

As a highly thermally conductive resin that can be melt-mixed, Patent Document 4 discloses an epoxy resin obtained by epoxidizing a mixture of hydroquinone and 4,4'-dihydroxybiphenyl. Patent Document 5 An epoxy resin obtained by epoxyizing a mixture of 4,4'-dihydroxydiphenylmethane and 4,4'-dihydroxybiphenyl is disclosed. However, these resins lack solvent solubility, and their applications are limited. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 7-90052 [Patent Document 2] Japanese Patent Laid-Open No. 9-118673 [Patent Document 3] Japanese Patent Laid-Open No. 11-323162 [Patent Document 4] WO2009/110424 [Patent Document 5] Japanese Patent Laid-Open No. 2010-43245

[The problem to be solved by the invention] Therefore, the object of the present invention is to solve the above-mentioned problems and provide an insulating material for electrical/electronic parts such as semiconductor seals, laminates, and heat dissipation substrates that are excellent in reliability, and have excellent handleability as a solid at room temperature, and A crystalline modified epoxy resin having excellent low viscosity and solvent solubility during molding, an epoxy resin composition using the same, and a cured product having excellent high thermal conductivity obtained therefrom. [Technical means to solve the problem]

Through active research, the inventors of the present invention have found that by reacting a mixture of compounds having a specific phenolic hydroxyl group with epichlorohydrin, the problem can be expected to be solved, and the cured product exhibits an effect in thermal conductivity.

（式中，G表示縮水甘油基，鍵結於聯苯環的縮水甘油基醚基為4,4'鍵或2,2'鍵，n表示0～10的數）。That is, the present invention is an epoxy resin, which is represented by the following general formula (1), and is characterized in that the total amount of n=0 body is 90 wt% or less, and the compound of n=1 body or more is 5 wt% to 35 wt%; [化1]

(In the formula, G represents a glycidyl group, the glycidyl ether group bonded to the biphenyl ring is a 4,4' bond or a 2,2' bond, and n represents a number from 0 to 10).

The present invention is the epoxy resin according to technical solution 1, which is obtained by reacting epichlorohydrin with a mixture containing 4,4'-dihydroxybiphenyl and 2,2'-dihydroxybiphenyl as monomers, It is represented by the general formula (1), and the sum of all n=0 bodies derived from each monomer is 90 wt% or less, and all n=1 bodies derived from each monomer including a copolymer structure The above compound is 5 wt% to 35 wt%. The present invention relates to a modified epoxy resin, which is characterized in that it is made by mixing epichlorohydrin and 4,4'-dihydroxybiphenyl with respect to 1 part by weight of 2,2'-dihydroxybiphenyl by 0.1 weight It is obtained by reacting a mixture of 10 parts by weight to 10 parts by weight, and the epoxy equivalent is in the range of 130 to 190.

Moreover, the present invention relates to an epoxy resin composition comprising an epoxy resin and a hardener, and the epoxy resin composition is characterized in that, as part or all of the epoxy resin, the epoxy resin is included as Essential ingredients.

Furthermore, the present invention relates to a resin cured product characterized in that it is formed by curing the resin composition. [Effects of the invention]

The epoxy resin and epoxy resin composition of the present invention are excellent in solvent solubility, moldability, and reliability, and can exhibit excellent high thermal conductivity of the cured product. Moreover, the yield is improved by suppressing crystallinity, which is also advantageous in terms of manufacturing. The reason for this excellent effect is presumed to be due to the co-existence of 4,4'-dihydroxybiphenyl and 2,2'-dihydroxybiphenyl as its isomers, to carry out epoxylation, On the other hand, it is possible to balance the improvement of the solvent solubility of the resin itself due to the relaxation of crystallinity and the maintenance of orientation that contributes to the thermal conductivity.

Hereinafter, the present invention will be described in detail.

The epoxy resin of the present invention is represented by the general formula (1), and the total n=0 volume is 90 wt% or less, and the n=1 volume or more compound is 5 wt% to 35 wt%. In the formula (1), the glycidyl ether group bonded to the biphenyl ring is a 4,4' bond or a 2,2' bond, and the 4,4' bond and the 2,2' bond coexist. Compounds with n=1 or more include homopolymers derived from 4,4'-dihydroxybiphenyl, homopolymers derived from 2,2'-dihydroxybiphenyl, and as 4,4'-dihydroxybiphenyl A mixture of copolymers of co-reaction structure of biphenyl and 2,2'-dihydroxybiphenyl. n represents the number of 0-10, and the average value (number average) is 0.1-5, Preferably it is the range of 0.1-2.

The modified epoxy resin of the present invention can be produced by reacting a mixture of 4,4'-dihydroxybiphenyl and 2,2'-dihydroxybiphenyl with epichlorohydrin. The reaction can be carried out in the same manner as a usual epoxyation reaction. The epoxy resin of the present invention is not only containing 4,4'-dihydroxybiphenyl epoxide and 2,2'-dihydroxybiphenyl epoxide, but also contains 4,4 A mixture of epoxides of units of'-dihydroxybiphenyl and 2,2'-dihydroxybiphenyl. Epoxides obtained by reacting dihydroxy compounds with epichlorohydrin include epoxides with a degree of polymerization of 0 (n=0 bodies), but also n=1 (two bodies), n=2 (three bodies), etc. Multimer.

In the epoxy resin of the present invention, the total of all n=0 bodies derived from each of the 4,4'-dihydroxybiphenyl and 2,2'-dihydroxybiphenyl structures is 90 wt% or less. If it exceeds the above range, there is a possibility that the crystallinity and melting point are high due to the 4,4'-dihydroxybiphenyl structure, and thus molding cannot be performed. On the other hand, the lower limit of the total amount of n=0 bodies is preferably 50 wt% or more, and more preferably 70 wt% or more. If it is less than this, the crystallinity becomes low, and there is a possibility that the thermal conductivity may decrease. Furthermore, the compound containing a co-reaction structure with n=1 or more is 5 wt% to 35 wt%, preferably 10 wt% to 30 wt%. If it is less than the above-mentioned range, there is a possibility that the melting point or crystallinity will not decrease and molding cannot be performed. On the other hand, if it is more than this, the thermal conductivity may decrease. Here, the co-reaction structure is formed by randomly reacting 4,4'-body and 2,2'-body. For example, if n=1 body, it has 4,4'-dihydroxybiphenyl and 2,2'- Epoxy resin with one dihydroxybiphenyl structure. By containing the epoxy resin of the said co-reaction structure, it becomes a resin which differs in characteristics from the case where the epoxy resin of a single structure containing each monomer is simply mixed.

The mixing ratio of 4,4'-dihydroxybiphenyl and 2,2'-dihydroxybiphenyl is based on weight ratio, 2,2'-dihydroxybiphenyl/4,4'-dihydroxybiphenyl=0.1～10.0 The range of is preferably 0.2 to 5.0, more preferably 0.3 to 3.0. If it is less than this, the handleability will be poor due to the influence of the high melting point of the epoxy compound of 4,4'-dihydroxybiphenyl, and if it is greater than this, the properties such as heat resistance and thermal conductivity of the cured product will decrease. The structure ratio of the obtained modified epoxy resin is also almost the same as the input ratio, so the range of the epoxy resin is also the same. That is, the glycidyl ether group that is derived from 2,2'-dihydroxybiphenyl and the glycidyl ether group bonded to the biphenyl ring is a 2,2' bond is a 2,2'-position structure, which is derived from 4,4'- Dihydroxybiphenyl, and the glycidyl ether group bonded to the biphenyl ring is 4,4' bond is 4,4' structure, 2,2' structure/4,4' structure The molar ratio exists in the stated range. Although it may contain isomer structures other than 4,4'-form and 2,2'-form, it is preferably 10 mol% or less.

A mixture of 4,4'-dihydroxybiphenyl and 2,2'-dihydroxybiphenyl (hereinafter referred to as a phenol mixture) is reacted with epichlorohydrin to obtain the epoxy resin of the present invention. Examples of the reaction with epichlorohydrin include: dissolving a mixture of phenols in epichlorohydrin in molar excess with respect to these phenolic hydroxyl groups, and then oxidizing alkali metals such as sodium hydroxide and potassium hydroxide. A method of reacting in the range of 50°C to 150°C, preferably 60°C to 100°C, for 1 hour to 10 hours in the presence of the substance. At this time, the usage amount of the alkali metal hydroxide is 0.8 mol to 1.2 mol, preferably 0.9 mol to 1.1 mol, relative to 1 mol of the hydroxyl group in the phenol mixture. Epichlorohydrin is used in excess with respect to the hydroxyl group in the phenol mixture, and is usually 1.5 mol to 15 mol, preferably 3 mol to 10 mol, relative to 1 mol of the hydroxyl group in the phenol mixture. After the reaction, the excess epichlorohydrin is distilled off, the residue is dissolved in toluene, methyl isobutyl ketone and other solvents, filtered, washed with water to remove inorganic salts, and then the solvent is distilled off. Target epoxy.

When manufacturing the epoxy resin of the present invention, as long as the effect of the present invention is not hindered, a small amount of 4,4'-dihydroxybiphenyl and 2,2'-dihydroxybiphenyl other than phenolic compounds can be mixed in the phenol mixture. Of other types of phenolic compounds. However, in this case, the total amount of other types of phenolic compounds is preferably 50% by weight or less, preferably 30% by weight or less, and more preferably 10% by weight or less of all phenolic compounds.

The epoxy equivalent of the epoxy resin of this invention is the range of 130-190 normally. In order to increase the thermal conductivity of the cured product, it is effective to fill the composition with a high level of inorganic filler. From the viewpoints of high filling rate of the inorganic filler and improvement of fluidity, epoxy resins are preferably those with low viscosity. On the one hand, if the epoxide content of 4,4'-dihydroxybiphenyl is large, an effect can be expected for thermal conductivity. If it is also considered that in order to control fluidity, etc., a small amount of 4,4'-dihydroxybiphenyl and 2,2'-dihydroxybiphenyl other types of phenolic compounds other than the phenolic compound is considered, it is more preferable to The epoxy equivalent is calculated to be in the range of 140 to 170.

The epoxy resin of the present invention has crystallinity at room temperature. The appearance of crystallinity can be confirmed by differential scanning calorimetry with the endothermic peak accompanying the melting of the crystal. In addition, regarding the endothermic peak at this time, since the modified epoxy resin of the present invention is a mixture, multiple peaks are generally observed instead of one. As the melting point observed by differential scanning calorimetry, the endothermic peak at the lowest temperature is calculated as the endothermic peak of modified epoxy resin derived from 4,4'-dihydroxybiphenyl and 2,2'-dihydroxybiphenyl It is 50°C or higher, preferably 70°C or higher, and the endothermic peak of the highest temperature is 150°C or lower, preferably 130°C or lower. If it is lower than this, blocking will occur when the powder is made, and the workability as a solid at room temperature will be reduced. If it is higher than this, there will be problems such as poor solubility with hardeners, etc. . Furthermore, it is preferable that the melt viscosity at 150°C is as low as possible, and is usually 0.1 Pa·s or less, preferably 0.01 Pa·s or less.

Regarding the purity of the modified epoxy resin of the present invention, particularly the amount of hydrolyzable chlorine, from the viewpoint of improving the reliability of electronic parts to be applied, it is better to be less. Although it is not particularly limited, it is preferably 1000 ppm or less, and more preferably 500 ppm or less. In addition, the amount of hydrolyzable chlorine in the present invention refers to a value measured by the following method. That is, after dissolving 0.5 g of the sample in 30 ml of dioxane, adding 10 ml of 1N-KOH, boiling and refluxing for 30 minutes, then cooling to room temperature, and then adding 100 ml of 80% acetone water to 0.002 The value obtained by potentiometric titration of an aqueous N-AgNO ₃ solution.

The epoxy resin composition containing the epoxy resin and the hardener of the present invention is characterized in that it contains the modified epoxy resin as an essential component as part or all of the epoxy resin. 70 wt% or more, more preferably 90 wt% or more is the modified epoxy resin. If the use ratio of the modified epoxy resin is less than this, the thermal conductivity improvement effect when the cured product is made is small.

In the epoxy resin composition of the present invention, in addition to the epoxy resin used as an essential component of the present invention, other ordinary epoxy resins having two or more epoxy groups in the molecule may be used in combination. For example, there are bisphenol A, bisphenol F, 3,3',5,5'-tetramethyl-4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenyl Benzene, 4,4'-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl ketone, fluorene bisphenol, 4,4'-biphenol, 3,3',5,5'-tetra Methyl-4,4'-dihydroxybiphenyl, resorcinol, catechol, hydroquinone, tert-butylcatechol, tert-butylhydroquinone, 1,2-dihydroxy Naphthalene, 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, the Binary phenols such as allylated or polyallylated dihydroxynaphthalene, allylated bisphenol A, allylated bisphenol F, allylated phenol novolac; or, phenol novolac , Bisphenol A novolac, o-cresol novolac, m-cresol novolac, p-cresol novolac, xylenol novolak, poly-p-hydroxystyrene, tris-(4-hydroxyphenyl) methane, 1 ,1,2,2-Tetra(4-hydroxyphenyl)ethane, fluoroglycinol, pyrogallol, tert-butyl pyrogallol, allylated pyrogallol, polyene Propyl pyrogallol, 1,2,4-benzenetriol, 2,3,4-trihydroxybenzophenone, phenol aralkyl resin, naphthol aralkyl resin, dicyclopentadiene series Ternary or higher phenols such as resins; or halogenated bisphenols such as tetrabromobisphenol A as raw materials, and glycidyl ether based compounds derived from these raw phenols. These epoxy resins can be used alone or in combination of two or more.

As the hardener used in the epoxy resin composition of the present invention, generally known as hardeners for epoxy resins can be used, including dicyandiamine, acid anhydrides, polyphenols, aromatic and aliphatic amines Wait. Among these, in fields requiring high electrical insulation such as semiconductor sealing materials, it is preferable to use polyhydric phenols as a curing agent. Specific examples of the curing agent are shown below.

Examples of polyphenols include bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, 4,4'-biphenol, 2,2'-biphenol, hydroquinone, resorcinol, naphthalene Binary phenols such as glycols; or, tris-(4-hydroxyphenyl)methane, 1,1,2,2-tetra(4-hydroxyphenyl)ethane, phenol novolac, o-cresol novolac , Naphthol novolac, polyvinyl phenol and other phenols with more than ternary elements. Furthermore, there are phenols, naphthols, bisphenol A, bisphenol F, bisphenol S, fluorene bisphenol, 4,4'-biphenol, 2,2'-biphenol, hydroquinone, and isobenzene. Polyphenolic compounds synthesized with binary phenols such as diphenols and naphthalenediols and condensation agents such as formaldehyde, acetaldehyde, benzaldehyde, p-hydroxybenzaldehyde, and terephthalic alcohol.

Examples of acid anhydride hardeners include phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl Methyl himic anhydride, dodecynyl succinic anhydride, nadic anhydride, trimellitic anhydride, etc.

As amine hardeners, there are 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl sulfide, m-phenylenediamine, p-benzene Aromatic amines such as dimethylamine; or aliphatic amines such as ethylenediamine, hexamethylenediamine, diethylenetriamine, and triethylenetetramine.

In the epoxy resin composition, one of these hardeners can be used or two or more of them can be mixed and used.

Regarding the blending ratio of the epoxy resin and the curing agent, it is preferable that the epoxy group and the functional group in the curing agent be in the range of 0.8 to 1.5 in terms of equivalent ratio. If it is outside the above range, unreacted epoxy groups or functional groups in the curing agent will remain after curing, and the reliability of the sealing function will decrease, which is not preferable.

In the resin composition of the present invention, polyester, polyamide, polyimide, polyether, polyurethane, petroleum resin, indene resin, indene/benzofuran resin, phenoxy resin, etc. can also be appropriately blended Oligomers or polymer compounds are used as other modifiers. About the addition amount, it is the range of 1 weight part-30 weight part normally with respect to 100 weight part of total resin components.

Furthermore, additives such as inorganic fillers, pigments, flame retardants, thixotropy imparting agents, coupling agents, and fluidity improvers can be blended in the resin composition of the present invention. Examples of inorganic fillers include thermally conductive fillers, such as spherical or crushed fused silica, crystalline silica and other silica powders, alumina powder, glass powder, or mica, talc, calcium carbonate, and alumina , Hydrated alumina, etc., when used in a semiconductor sealing material, the preferred blending amount is 70% by weight or more, and more preferably 80% by weight or more.

As the pigment, there are organic or inorganic extender pigments, flake pigments, and the like. Examples of the thixotropy imparting agent include silicon-based, castor oil-based, aliphatic amide wax, oxidized polyethylene wax, and organic bentonite-based.

Furthermore, the epoxy resin composition of this invention may use a hardening accelerator as needed. For example, there are amines, imidazoles, organic phosphines, Lewis acids, etc., specifically: 1,8-diazabicyclo(5,4,0)undecene-7, triethylenediamine , Benzyldimethylamine, triethanolamine, dimethylaminoethanol, tris(dimethylaminomethyl)phenol and other amines; or, 2-methylimidazole, 2-phenylimidazole, 2-ethyl- 4-methylimidazole, 2-phenyl-4-methylimidazole, 2-heptadecylimidazole and other imidazoles; or, tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenyl Phosphine, phenyl phosphine and other organic phosphines; or, tetraphenyl phosphonium/tetraphenyl borate, tetraphenyl phosphonium/ethyl triphenyl borate, tetrabutyl phosphonium/tetrabutyl borate and other tetra-substituted phosphonium /Tetra-substituted borate, Lewis acid such as 2-ethyl-4-methylimidazole/tetraphenyl borate, N-methylmorpholine/tetraphenyl borate and other tetraphenyl borate salts. As an addition amount, it is the range of 0.01 weight part to 5 weight part normally with respect to 100 weight part of total resin components.

If necessary, release agents such as carnauba wax and OP wax, coupling agents such as γ-glycidoxypropyltrimethoxysilane, coloring agents such as carbon black, and three Flame retardants such as antimony oxide, stress reducing agents such as silicone oil, lubricants such as calcium stearate, etc.

The resin composition of the present invention can be made into a varnish state in which an organic solvent is dissolved, and then impregnated into fibrous materials such as glass cloth, polyaramide nonwoven fabric, and polyester nonwoven fabric such as liquid crystal polymer. The solvent is removed to make a prepreg. Moreover, it can be made into a laminate by coating it on a sheet-like article, such as a copper foil, a stainless steel foil, a polyimide film, and a polyester film, according to the situation.

If the resin composition of the present invention is heated and cured, it can be made into the cured resin of the present invention. The cured product can be obtained by molding an epoxy resin composition by methods such as casting, compression molding, transfer molding, and the like. The temperature at this time is usually in the range of 120°C to 220°C. [Example]

Hereinafter, synthesis examples, examples, and comparative examples are given to specifically explain the present invention. However, the present invention is not limited to these. Unless otherwise specified, "parts" means parts by weight, and "%" means% by weight. In addition, as for the measurement methods, the following methods were used for measurement.

1) Epoxy equivalent A potentiometric titration device was used, methyl ethyl ketone was used as a solvent, and a tetraethylammonium bromide acetic acid solution was added, and the potentiometric titration device was measured with a 0.1 mol/L perchloric acid-acetic acid solution.

2) Melting point Using a differential scanning calorimetry device (manufactured by SII NanoTechnology Co., Ltd., EXSTAR 6000 DSC/6200), the differential scanning calorimetric analysis was obtained under the condition of a heating rate of 5°C/min ( differential scanning calorimetry, DSC) peak temperature. That is, the DSC peak temperature is regarded as the melting point of the resin.

3) Melt viscosity The measurement was carried out at 150°C using a CAP2000H type rotary viscometer manufactured by Brookfield (BROOKFIELD).

4) Softening point According to Japanese Industrial Standards (JIS)-K-2207, the measurement is carried out by the ring and ball method.

5) GPC measurement The main body (manufactured by Tosoh Co., Ltd., HLC-8220GPC) uses an apparatus having columns (manufactured by Tosoh Co., Ltd., TSKgelG4000HXL, TSKgelG3000HXL, TSKgelG2000HXL) connected in series, and the column temperature is set to 40°C. Furthermore, tetrahydrofuran (THF) was used for the eluent, and a flow rate of 1 mL/min was used, and a differential refractive index detector was used as the detector. As the measurement sample, 50 μL of 0.1 g sample was dissolved in 10 mL of THF and filtered with a microfilter. For data processing, GPC-8020 model II version 6.00 manufactured by Tosoh Co., Ltd. was used.

6) Glass transition point (Tg) Using a thermomechanical measuring device (manufactured by SII NanoTechnology Co., Ltd., EXSTAR 6000 TMA/6100), the Tg was determined under the conditions of a temperature increase rate of 10°C/min.

7) 5% weight reduction temperature (Td5), residual carbon rate Using a thermogravimetric/differential thermal analysis device (manufactured by SII NanoTechnology, EXSTAR 6000 TG/DTA6200), in a nitrogen atmosphere, measuring 5% at a heating rate of 10°C/min Weight reduction temperature (Td5). Furthermore, the weight loss at 700°C was measured and calculated as the residual carbon rate.

8) Dielectric constant and dielectric loss tangent According to IPC-TM-650 2.5.5.9, using a material analyzer (manufactured by AGILENT Technologies), the capacitance method was used to obtain the dielectric constant and dielectric loss tangent at a frequency of 1 GHz, and then the evaluation was performed.

9) Thermal conductivity The LFA447 thermal conductivity meter manufactured by NETZSCH was used for the measurement by the Transient Hot Wire Method.

Example 1 Dissolve 50.0 g of 4,4'-dihydroxybiphenyl and 50.0 g of 2,2'-dihydroxybiphenyl in 500 g of epichlorohydrin and 75 g of diethylene glycol dimethyl ether, and add 48% at 60℃ 8.8 g of sodium hydroxide was stirred for 1 hour. Thereafter, under reduced pressure (about 130 Torr), 78.8 g of a 48% sodium hydroxide aqueous solution was added dropwise over 3 hours. In the meantime, the generated water is removed from the system by azeotrope with epichlorohydrin, and the distilled epichlorohydrin is returned to the system. After the dripping, the reaction was continued for 1 hour for dehydration, after which the epichlorohydrin was distilled off, 370 g of toluene was added, and the salt was removed by water washing. Then, after removing water by liquid separation, toluene was distilled off under reduced pressure to obtain 130 g of a white crystalline epoxy resin (epoxy resin A). The epoxy equivalent is 159, the hydrolyzable chlorine is 55 ppm, the melting point is 123°C, and the viscosity at 150°C is 7.0 mPa·s. The n=0 (monomer) of the epoxy resin obtained from 4,4'-dihydroxybiphenyl determined by GPC measurement was 36.4%. Moreover, the n=0 (monomer) of the epoxy resin obtained from 2,2'-dihydroxybiphenyl was 37.9%. 25.7% above n=1.

Example 2 Dissolve 70.0 g of 4,4'-dihydroxybiphenyl and 30.0 g of 2,2'-dihydroxybiphenyl in 500 g of epichlorohydrin and 75 g of diethylene glycol dimethyl ether, and add 48% at 60℃ 8.8 g of sodium hydroxide was stirred for 1 hour. Thereafter, under reduced pressure (about 130 Torr), 78.8 g of a 48% sodium hydroxide aqueous solution was added dropwise over 3 hours. In the meantime, the generated water is removed from the system by azeotrope with epichlorohydrin, and the distilled epichlorohydrin is returned to the system. After the dripping, the reaction was continued for 1 hour for dehydration, after which the epichlorohydrin was distilled off, 370 g of toluene was added, and the salt was removed by washing with water. After that, after removing water by liquid separation, toluene was distilled off under reduced pressure to obtain 125 g of a white crystalline modified epoxy resin (epoxy resin B). The epoxy equivalent is 157, the hydrolyzable chlorine is 89 ppm, the melting point is 141°C, and the viscosity at 150°C is 6.1 mPa·s. The n=0 (monomer) of the epoxy resin obtained from 4,4′-dihydroxybiphenyl determined by GPC measurement was 61.3%. Moreover, the n=0 (monomer) of the epoxy resin obtained from 2,2'-dihydroxybiphenyl was 26.3%. 12.4% above n=1.

Comparative example 1 Dissolve 50.0 g of hydroquinone and 100.0 g of 4,4'-dihydroxybiphenyl in 1000 g of epichlorohydrin and 150 g of diethylene glycol dimethyl ether, and add 16.5 g of 48% sodium hydroxide at 60°C , Stir for 1 hour. Thereafter, under reduced pressure (about 130 Torr), 148.8 g of a 48% sodium hydroxide aqueous solution was added dropwise over 3 hours. In the meantime, the generated water is removed from the system by azeotrope with epichlorohydrin, and the distilled epichlorohydrin is returned to the system. After the dropwise addition was completed, the reaction was continued for 1 hour for dehydration, after which the epichlorohydrin was distilled off, 600 g of methyl isobutyl ketone was added, and the salt was removed by washing with water. Thereafter, 13.5 g of 48% sodium hydroxide was added at 85°C, stirred for 1 hour, and washed with 200 mL of warm water. After that, after removing water by liquid separation, methyl isobutyl ketone was distilled off under reduced pressure to obtain 224 g of white crystalline modified epoxy resin (epoxy resin C). The epoxy equivalent is 139, the hydrolyzable chlorine is 320 ppm, the melting point is 125°C, and the viscosity at 150°C is 3.4 mPa·s. The n=0 (monomer) of the epoxy resin obtained from 4,4'-dihydroxybiphenyl determined by GPC measurement was 67.2%. Also, the n=0 (monomer) of the epoxy resin obtained from hydroquinone was 23.1%. 9.7% for n=1 or more.

Comparative example 2 Dissolve 100.0 g of 2,2'-dihydroxybiphenyl in 500 g of epichlorohydrin and 75 g of diethylene glycol dimethyl ether, add 8.8 g of 48% sodium hydroxide at 60°C, and stir for 1 hour. Thereafter, under reduced pressure (about 130 Torr), 78.8 g of a 48% sodium hydroxide aqueous solution was added dropwise over 3 hours. In the meantime, the generated water is removed from the system by azeotrope with epichlorohydrin, and the distilled epichlorohydrin is returned to the system. After the dripping, the reaction was continued for 1 hour for dehydration, after which the epichlorohydrin was distilled off, 370 g of toluene was added, and the salt was removed by water washing. Thereafter, after removing water by liquid separation, toluene was distilled off under reduced pressure to obtain 136 g of a liquid epoxy resin (epoxy resin D). The epoxy equivalent is 162, the hydrolyzable chlorine is 29 ppm, and the viscosity at 150°C is 6.2 mPa·s. The ratio of each component of the obtained resin determined by GPC measurement was 78.4% for n=0, and 21.6% for n=1 or more.

Comparative example 3 Dissolve 100.0 g of 4,4'-dihydroxybiphenyl in 700 g of epichlorohydrin and 105 g of diethylene glycol dimethyl ether. Then, under reduced pressure (about 130 Torr) at 60°C, it takes 3 hours Drop 87.8 g of 48% sodium hydroxide aqueous solution. In the meantime, the generated water is removed from the system by azeotrope with epichlorohydrin, and the distilled epichlorohydrin is returned to the system. After the dropwise addition was completed, the reaction was continued for 1 hour and dehydrated, then cooled to normal temperature, filtered, and the precipitate was recovered. After that, the precipitate was washed with water to remove the salt, and further dried to obtain 137 g of a crystalline powdered epoxy resin (epoxy resin E). The epoxy equivalent is 163 and the melting point is 172°C. The ratio of each component of the obtained resin determined by GPC measurement was 93.7% for n=0, and 5.9% for n=1 or more.

Confirmation of solvent solubility The solvent solubility was judged by adding 5 g of solvents (methyl ethyl ketone, toluene, cyclohexanone) so that the solid content concentration was 10% by weight, 15% by weight, and 20% by weight. Example 1 The epoxy resin A and the epoxy resin B obtained in Example 2, the epoxy resin C, and the epoxy resin E obtained in Comparative Example 1, and Comparative Example 3 were sufficiently stirred at room temperature, and the insoluble components were visually confirmed. The case where there is an insoluble component is set to ×, and the case where there is no component is set to 0. In addition, when the insoluble component was confirmed to be heated to 60°C, the insoluble component was confirmed to be dissolved as △. The results are shown in Table 1.

[Table 1] Solvent Solid content% Epoxy A Epoxy B Epoxy C Epoxy E Methyl ethyl ketone 10 〇 〇 △ × 15 〇 △ × × 20 △ △ × × Toluene 10 〇 〇 △ × 15 〇 △ × × 20 △ △ × × Cyclohexanone 10 〇 〇 〇 × 15 〇 〇 △ × 20 〇 〇 × × Melting point (℃) 123 141 125 172

Example 3, Example 4 and Comparative Example 4 to Comparative Example 7 As the epoxy resin components, epoxy resin A and epoxy resin B obtained in Example 1, Example 2, and epoxy resin C and epoxy resin D obtained in Comparative Example 1, Comparative Example 2, and Comparative Example 3 were used. , Epoxy E and biphenyl epoxy resin (Epoxy F: manufactured by Japan Epoxy Resin, YX-4000H; epoxy equivalent 195), as a hardener, use phenol novolac resin (PN ; Hydroxyl equivalent 105 g/eq., softening point 67℃). As a hardening accelerator, triphenylphosphine was used, and the epoxy resin composition was obtained by the formulation shown in Table 2. The values in the table indicate parts by weight in the blend. The epoxy resin composition was used for molding at 175°C and post-curing at 175°C for 5 hours to obtain a cured product test piece, which was then used for various physical property measurements.

[Table 2] Example 3 Example 4 Comparative example 4 Comparative example 5 Comparative example 6 Comparative example 7 Epoxy A 18.1 Epoxy B 18.1 Epoxy C 18.2 Epoxy D 17.1 9.1 Epoxy E 9.1 Epoxy F 19.2 hardener 11.9 11.9 11.8 12.9 10.8 11.8 Triphenylphosphine 0.24 0.24 0.24 0.24 0.24 0.24 Tg (℃) 117 123 122 101 124 Unable to form Td5 (℃) 393 393 393 385 369 Residual carbon rate (wt%) 16 twenty two 19 15 18 Dielectric constant 3.27 3.31 3.36 3.30 3.30 Dielectric loss tangent 0.021 0.021 0.026 0.021 0.020 Thermal conductivity (W/m·k) 0.25 0.25 0.26 0.20 0.20

As is clear from these results, the epoxy resins obtained in the examples have excellent solvent solubility, and the cured products have excellent thermal conductivity. Furthermore, it can be seen that the thermal stability is good, indicating a low dielectric loss tangent.

no.

Figure 1 is a gel permeation chromatography (GPC) diagram of modified epoxy resin A (Example 1).

Claims (5)

An epoxy resin, which is represented by the following general formula (1), and is characterized in that the sum of n=0 bodies is 90 wt% or less, and the compounds with n=1 body or more are 5 wt% to 35 wt%:

(In the formula, G represents a glycidyl group, the glycidyl ether group bonded to the biphenyl ring is a 4,4' bond or a 2,2' bond, and n represents a number from 0 to 10). The epoxy resin described in item 1 of the scope of patent application is obtained by reacting epichlorohydrin with a mixture containing 4,4'-dihydroxybiphenyl and 2,2'-dihydroxybiphenyl as monomers, It is represented by the general formula (1), and the sum of all n=0 bodies derived from each monomer is 90 wt% or less, and all n=1 bodies derived from each monomer including a copolymer structure The above compound is 5 wt% to 35 wt%. The epoxy resin described in item 1 of the scope of the patent application is made by mixing epichlorohydrin with 1 part by weight of 4,4'-dihydroxybiphenyl and 0.1 part by weight of 2,2'-dihydroxybiphenyl. It is obtained by reacting 10 parts by weight of the mixture, and the epoxy equivalent is in the range of 130 to 190. An epoxy resin composition comprising an epoxy resin and a hardener. The epoxy resin composition is characterized in that, as part or all of the epoxy resin, it contains any one of items 1 to 3 in the scope of the patent application. The epoxy resin described in the item is an essential component. A cured resin characterized in that it is formed by curing the epoxy resin composition described in item 4 of the scope of patent application.

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