KR20240026887A - Epoxy resin, epoxy resin composition, and cured product thereof - Google Patents

Abstract

An epoxy resin composition useful for sealing electrical and electronic components, circuit board materials, etc., which provides a cured product with good melt kneading properties below 100°C and excellent solvent solubility as well as excellent heat resistance, thermal decomposition stability, thermal conductivity, and tracking resistance. provides. An epoxy resin represented by the following general formula (1), wherein the epoxy equivalent weight is 180 to 240 g/eq and the softening point is in the range of 60 to 95°C.

In the formula, G represents a glycidyl group, and A represents a single bond, an oxygen atom, a sulfur atom, -SO ₂ -, -CO-, or a divalent hydrocarbon having 1 to 6 carbon atoms. n and m each independently represent numbers from 0 to 20.

Description

Epoxy resin, epoxy resin composition, and cured product thereof

The present invention relates to epoxy resins, epoxy resin compositions, and cured epoxy resins, and specifically to epoxy resins, epoxy resin compositions, and cured epoxy resins. In detail, they are useful for insulating materials for electrical and electronic components such as semiconductor seals, laminates, and heat dissipation substrates, and are useful for handling as a solid at room temperature and low point during molding. It relates to epoxy resins with excellent coating properties and solvent solubility, epoxy resin compositions, and cured epoxy resin products obtained by curing them and with excellent heat resistance, thermal decomposition stability, thermal conductivity, and tracking resistance.

Epoxy resins are used in a wide range of industrial applications, but their required performance has become increasingly sophisticated in recent years. Meanwhile, in power devices that are being developed recently, further improvement in the power density of the devices is required. As a result, the temperature of the chip surface during operation is 200°C or higher, so it is possible to withstand that temperature. There is a need for the development of sealing materials.

Meanwhile, Patent Document 1 discloses an epoxy resin having a biphenol-biphenyl aralkyl structure, and shows that it is excellent in heat resistance, moisture resistance, and thermal conductivity. Patent Document 2 also discloses an epoxy resin composition having a biphenol-biphenyl aralkyl structure, and shows that a cured product excellent in heat resistance and thermal decomposition stability can be obtained. However, since its handleability is that it is a crystalline epoxy resin with a melting point of 100°C or higher, melt-kneading at high temperature was necessary when mixing it with a curing agent or the like. At high temperatures, the curing reaction between the epoxy resin and the curing agent proceeds rapidly and the gelation time is shortened, so mixing treatment was strictly limited. Additionally, because it exhibits strong crystallinity, there is a problem with solvent solubility, making application to laminated boards difficult.

There is a proposal in Patent Document 3 to reduce crystallinity by removing the crystal component of an epoxy resin having a biphenol-biphenyl aralkyl structure, but the solvent solubility is insufficient, which poses a problem in practicality. In addition, when mixing different epoxy resins to improve moldability and solvent solubility, the melting point of the resin decreases, making it easier to mix uniformly, while maintaining the physical properties of the cured product such as heat resistance, thermal decomposition stability, mechanical strength, and thermal conductivity. It gets difficult. Patent Document 4 proposes a composition capable of maintaining physical properties, but melt-kneading at 100°C or lower is difficult, and solvent solubility is also insufficient for practical use in laminate applications.

WO2011/074517 WO2014/065152 Japanese Patent Publication No. 2017-95524 Japanese Patent Publication No. 2015-160893

The object of the present invention is to seal electrical and electronic components and circuit boards by providing a cured product that has good melt kneading properties below 100°C and excellent solvent solubility, as well as excellent heat resistance, thermal decomposition stability, thermal conductivity, and tracking resistance. The object is to provide an epoxy resin composition useful for materials, etc., and to provide a cured product thereof. Another object is to provide an epoxy resin used in this epoxy resin composition and a polyvalent hydroxy resin suitable as an intermediate for this epoxy resin.

The present inventors conducted intensive studies and found that an epoxy resin having a specific structure is expected to solve the above problems, and that the cured product exhibits effects on heat resistance, thermal decomposition stability, thermal conductivity, and tracking resistance.

In other words, the present invention is an epoxy resin represented by the following general formula (1), characterized by an epoxy equivalent weight of 180 to 240 g/eq and a softening point in the range of 60 to 100°C.

In the formula, G represents a glycidyl group, and A represents a single bond, an oxygen atom, a sulfur atom, -SO ₂ -, -CO-, or a divalent hydrocarbon having 1 to 6 carbon atoms. n and m each independently represent numbers from 0 to 20.

In the general formula (1), it is preferable that the component with n = 0 and m = 0 is 35% or less in the area % measured by gel permeation chromatography (GPC area %).

Additionally, in the present invention, after reacting 4,4'-dihydroxybiphenyl represented by formula (2) with an aromatic crosslinking agent represented by formula (3), a bifunctional phenolic compound represented by formula (4) is added. The method for producing the above epoxy resin is characterized by further reacting to obtain a polyhydric hydroxy resin represented by the general formula (5), and reacting the polyhydric hydroxy resin with epichlorohydrin.

Here, X represents a hydroxyl group, a halogen atom, or an alkoxy group having 1 to 6 carbon atoms.

Here, A represents a single bond, an oxygen atom, a sulfur atom, -SO ₂ -, -CO-, or a divalent hydrocarbon having 1 to 6 carbon atoms.

Here, A represents a single bond, an oxygen atom, a sulfur atom, -SO ₂ -, -CO-, or a divalent hydrocarbon having 1 to 6 carbon atoms. n and m each independently represent numbers from 0 to 20.

Furthermore, the present invention is an epoxy resin composition characterized by containing the above-mentioned epoxy resin and a curing agent as essential components, and is also a cured epoxy resin product characterized by curing this epoxy resin cured product.

The epoxy resin of the present invention has good melt kneading properties at 100°C or lower and excellent solvent solubility, so it is suitable for epoxy resin compositions and cured products thereof used in applications such as lamination, molding, molding, and adhesion. Additionally, this cured product has excellent heat resistance, thermal decomposition stability, thermal conductivity, and tracking resistance, and is therefore suitable for sealing electrical and electronic components, circuit board materials, etc.

Figure 1 is a GPC chart of the epoxy resin obtained in Example 1.

Hereinafter, the present invention will be described in detail.

The epoxy resin of the present invention is represented by general formula (1), and the epoxy equivalent weight (g/eq.) is 180 to 240. Preferably it is 190 to 230.

Here, n and m are the repetition number (number average) and represent a number from 0 to 20, and G is a glycidyl group. Preferably, it is a mixture of components with different values of n and m. The ratio (molar ratio) of n/(n+m) is preferably 0.50 to 0.95, and more preferably 0.70 to 0.95. If it is less than 0.50, the effect of heat resistance and high thermal conductivity is small, and if it is greater than 0.95, crystallinity becomes strong and solvent solubility decreases.

A represents a single bond, an oxygen atom, a sulfur atom, -SO ₂ -, -CO-, or a divalent hydrocarbon having 1 to 6 carbon atoms. It is preferable that the substitution positions of the two OG groups bonded to the biphenyl structure having A include at least the 2,2' form. In General Formula (1), when A is a single bond, that is, when both ends of the epoxy resin are biphenyl rings, the substitution positions of the two bonding OG groups are preferably at the 4,4' position and the 2,2' position. And, the ratio of biphenyl at both ends is preferably 40 to 90 mol% of the total at the 2,2' position. When A is other than a single bond, that is, both ends of the epoxy resin are other than a biphenyl ring, for example, when it is a diphenylmethane structure, the substitution position of the two bonding OG groups is 30 to 100 at the 4,4' position. Mol% is preferred.

The softening point of the epoxy resin of the present invention is in the range of 60 to 95°C. If the softening point is lower than 60°C, it becomes a liquid or semi-solid epoxy resin, making handling difficult. If it is higher than 95°C, melt kneading property decreases, and if it has crystallinity, solvent solubility also decreases. More preferably, it is 90°C or lower.

The epoxy resin of the present invention can be produced by reacting the polyhydric hydroxy resin represented by formula (5) with epichlorohydrin.

Here, the n/(n+m) ratio of the polyhydric hydroxy resin is the same as that of the present epoxy resin described above.

This polyvalent hydroxy resin is expressed by formula (4) after reacting 4,4'-dihydroxybiphenyl represented by formula (2) with an aromatic crosslinking agent having a biphenyl structure represented by formula (3). It can be produced by reacting with a bifunctional phenolic compound.

Here, X represents a hydroxyl group, a halogen atom, or an alkoxy group having 1 to 6 carbon atoms.

The molar ratio at the time of injection of the 4,4'-dihydroxybiphenyl represented by formula (2) of the synthetic raw material and the bifunctional phenolic compound represented by formula (4) is 4,4'-dihydroxy ratio. The phenyl content is preferably 0.50 to 0.95, and more preferably 0.70 to 0.95. If the ratio of 4,4'-dihydroxybiphenyl is less than this range, heat resistance and high thermal conductivity are insufficient, and in many cases, solvent solubility decreases due to strong crystallinity. As the bifunctional phenol compound of formula (4), specifically, 2,2'-dihydroxybiphenyl, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl ketone, 4 , 4'-dihydroxydiphenyl sulfone, 4,4'-dihydroxydiphenyl sulfide, dihydroxydiphenylmethane, 2,2-bis(4-hydroxyphenyl)propane, especially solvent soluble In light of this, 2,2'-dihydroxybiphenyl, 4,4'-dihydroxydiphenyl ether, and dihydroxydiphenylmethane are preferable. Dihydroxydiphenylmethane may be a mixture of ortho, meta, and para, but it is preferable that the isomer ratio of 4,4'-dihydroxydiphenylmethane is 40% or less. If there is a large amount of 4,4'-dihydroxydiphenylmethane, crystallinity is strong and there is a risk that solvent solubility may decrease.

In the aromatic crosslinking agent represented by the above formula (3), X represents a hydroxyl group, a halogen atom, or an alkoxy group having 1 to 6 carbon atoms. As an aromatic condensing agent, specifically, 4,4'-bishydroxymethylbiphenyl, 4,4'-bischloromethylbiphenyl, 4,4'-bisbromomethylbiphenyl, 4,4'-bis. Examples include methoxymethyl biphenyl and 4,4'-bisethoxymethyl biphenyl. From the viewpoint of reactivity, 4,4'-bishydroxymethylbiphenyl or 4,4'-bischloromethylbiphenyl is preferable, and from the viewpoint of reducing ionic impurities, 4,4'-bishydroxymethylbiphenyl , or 4,4'-bismethoxymethylbiphenyl is preferred.

The mole ratio when reacting phenols and aromatic condensing agents is generally in the range of 0.2 to 0.7 mol of aromatic condensing agent per mole of phenols, and more preferably in the range of 0.4 to 0.7 mol. If it is less than 0.2 mol, the ratio of the n = 0 body of the polyhydroxy resin obtained increases, and there is concern that the solubility may decrease, such as showing crystallinity. On the other hand, if it is more than 0.7 mol, the number of high molecular weight components increases and it becomes difficult to produce it stably.

The reaction between phenols and aromatic condensing agents can be carried out without a catalyst or in the presence of an acid catalyst such as an inorganic acid or organic acid. When using 4,4'-bischloromethylbiphenyl, the reaction can be carried out without a catalyst, but in general, it is better to carry out the reaction in the presence of an acidic catalyst to suppress side reactions such as the formation of an ether bond when the chloromethyl group reacts with the hydroxyl group. good night. This acid catalyst can be appropriately selected from known inorganic acids and organic acids, for example, mineral acids such as hydrochloric acid, sulfuric acid, phosphoric acid, formic acid, oxalic acid, trifluoroacetic acid, p-toluenesulfonic acid, metasulfonic acid, and trifluoromethane. Examples include organic acids such as sulfonic acid, Lewis acids such as zinc chloride, aluminum chloride, iron chloride, and boron trifluoride, or solid acids.

Usually, this reaction is carried out at 100 to 250°C for 1 to 20 hours. Preferably it is carried out at 100 to 180°C, more preferably at 140 to 180°C. If the reaction temperature is low, reactivity is insufficient and time is required, and if the reaction temperature is high, there is a risk of resin decomposition.

As a solvent during the reaction, for example, alcohols such as methanol, ethanol, propanol, butanol, ethylene glycol, methyl cellosolve, ethyl cellosolve, diethylene glycol dimethyl ether, triglyme, benzene, toluene, and chlorobenzene. It is preferable to use aromatic compounds such as dichlorobenzene, and among these, ethyl cellosolve, diethylene glycol dimethyl ether, triglyme, etc. are particularly preferable. After completion of the reaction, the solvent may be removed from the obtained polyhydric hydroxy resin by methods such as distillation under reduced pressure, washing with water, or reprecipitation in a poor solvent, or it may be used as a raw material for an epoxidation reaction with the solvent remaining.

In addition to being used as a raw material for epoxy resin, the polyvalent hydroxy resin obtained in this way can also be used as an epoxy resin curing agent. Additionally, it can also be applied as a phenol resin molding material by combining it with a curing agent such as hexamine.

The method for producing the epoxy resin of the present invention by reacting the polyhydric hydroxy resin represented by the above formula (5) with epichlorohydrin will be described. This reaction can be performed similarly to the known epoxidation reaction.

For example, after dissolving the above-mentioned polyvalent hydroxy resin in an excess of epichlorohydrin, in the presence of an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, the temperature is 1 to 150°C, preferably 60 to 120°C. One method is to react for 10 hours. The amount of epichlorohydrin used at this time is 0.8 to 2 mol, preferably 0.9 to 1.2 mol, per 1 mol of hydroxyl groups in the polyhydric hydroxy resin. After completion of the reaction, excess epichlorohydrin is distilled off, the residue is dissolved in a solvent such as toluene, methyl isobutyl ketone, filtered, and washed with water to remove inorganic salts, and then the solvent is distilled off to obtain the general formula above. The desired epoxy resin represented by (1) can be obtained. When carrying out the epoxidation reaction, a catalyst such as a quaternary ammonium salt may be used.

The purity, especially the amount of hydrolyzable chlorine, of the epoxy resin of the present invention is preferably lower from the viewpoint of improving the reliability of the electronic components to which it is applied. Although it is not particularly limited, it is preferably 1000 ppm or less, and more preferably 500 ppm or less. In addition, hydrolyzable chlorine as used in the present invention refers to the value measured by the following method. In other words, 0.5 g of the sample was dissolved in 30 ml of dioxane, 10 ml of 1N-KOH was added, boiled and refluxed for 30 minutes, cooled to room temperature, and additionally 100 ml of 80% acetone water was added, and 0.002 N-AgNO ₃ This is a value obtained by performing potentiometric titration with an aqueous solution.

The epoxy resin composition of the present invention includes an epoxy resin and a curing agent, and includes an epoxy resin of the general formula (1) as an epoxy resin component.

In the epoxy resin composition of the present invention, in addition to the epoxy resin of general formula (1) used as an essential component, other common epoxy resins having two or more epoxy groups in the molecule may be used together. For example, bisphenol A, bisphenol F, 3,3',5,5'-tetramethyl-4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenylsulfone, 4,4 '-dihydroxydiphenyl sulfide, 4,4'-dihydroxydiphenyl ketone, fluorenebisphenol, 4,4'-biphenol, 3,3',5,5'-tetramethyl-4,4 '-dihydroxybiphenyl, 2,2'-biphenol, resorcin, catechol, t-butylcatechol, t-butylhydroquinone, 1,2-dihydroxynaphthalene, 1,3-dihydroxy Naphthalene, 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 , dihydric phenols such as allylated or polyallylated products of dihydroxynaphthalene, allylated bisphenol A, allylated bisphenol F, allylated phenol novolac, or phenol novolak, bisphenol A novolac, o-cresol novolac. , m-cresol novolak, p-cresol novolak, xylenol novolac, poly-p-hydroxystyrene, tris-(4-hydroxyphenyl)methane, 1,1,2,2-tetrakis (4- Hydroxyphenyl)ethane, fluoroglycinol, pyrogallol, t-butylpyrogallol, allylated pyrogallol, polyallylated pyrogallol, 1,2,4-benzenetriol, 2,3,4-trihydride There are glycidyl ethers derived from trivalent or higher phenols such as hydroxybenzophenone, phenol aralkyl resin, naphthol aralkyl resin, and dicyclopentadiene-based resin, or halogenated bisphenols such as tetrabromobisphenol A. These epoxy resins can be used one type or in a mixture of two or more types.

The epoxy resin composition of the present invention preferably contains 50 wt% or more of the epoxy resin of the general formula (1) as an epoxy resin. More preferably, it is 70 wt% or more, more preferably 80 wt% or more of the total epoxy resin. If the usage ratio is less than this, the moldability as an epoxy resin composition deteriorates, and the effect of improving heat resistance, thermal conductivity, etc. when used as a cured product is small.

As the curing agent used in the epoxy resin composition of the present invention, all those generally known as curing agents for epoxy resins can be used, and include dicyandiamide, acid anhydrides, polyhydric phenols, aromatic and aliphatic amines, etc. Among these, in fields where high electrical insulation is required, such as semiconductor encapsulation materials, it is preferable to use polyhydric phenols as a curing agent. Below, specific examples of the curing agent are shown.

Examples of polyhydric phenols include dihydric phenols such as bisphenol A, bisphenol F, bisphenol S, fluorenebisphenol, 4,4'-biphenol, 2,2'-biphenol, hydroquinone, resorcin, and naphthalenediol; or tris-(4-hydroxyphenyl)methane, 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, phenol novolak, o-cresol novolak, naphthol novolac, polyvinylphenol, etc. There are three or more phenols represented. In addition, divalent phenols such as phenols, naphthols, bisphenol A, bisphenol F, bisphenol S, fluorenebisphenol, 4,4'-biphenol, 2,2'-biphenol, hydroquinone, resorcin, naphthalenediol, etc. , polyhydric phenolic compounds synthesized using condensing agents such as formaldehyde, acetaldehyde, benzaldehyde, p-hydroxybenzaldehyde, and p-xylylene glycol.

Examples of acid anhydride curing agents include phthalic anhydride, tetrahydrophthalic anhydride, methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, methylhexahydrophthalic anhydride, methyl hymic acid anhydride, dodecinylsuccinic anhydride, nadic anhydride, and trianhydride. Mellitic acid, etc.

As amine-based curing agents, 4,4'-diaminodiphenylmethane, 4,4'-diaminodiphenylpropane, 4,4'-diaminodiphenyl sulfone, m-phenylenediamine, and p-xylylenediamine. There are aromatic amines such as ethylenediamine, hexamethylenediamine, diethylenetriamine, and triethylenetetramine.

In the above epoxy resin composition, one type or a mixture of two or more types of these curing agents can be used.

The mixing ratio of the epoxy resin and the curing agent is preferably in the range of 0.8 to 1.5 in terms of the equivalent ratio of the epoxy group to the functional group in the curing agent. Outside this range, unreacted epoxy groups or functional groups in the curing agent remain even after curing, which is undesirable because the reliability of the sealing function decreases.

In the epoxy resin composition of the present invention, oligomers or polymer compounds such as polyester, polyamide, polyimide, polyether, polyurethane, petroleum resin, indene resin, indene/coumarone resin, and phenoxy resin are appropriately mixed as other modifiers. You can do it. The addition amount is usually in the range of 1 to 30 parts by weight based on a total of 100 parts by weight of the resin component.

The epoxy resin composition of the present invention can be blended with additives such as inorganic fillers, pigments, flame retardants, thixotropy imparting agents, coupling agents, and fluidity improvers. Examples of inorganic fillers include silica powder such as spherical or crushed fused silica and crystalline silica, alumina powder, glass powder, mica, talc, calcium carbonate, alumina, hydrated alumina, etc., which are used in semiconductor sealing materials. The preferred mixing amount in this case is 70% by weight or more, and more preferably 80% by weight or more.

Pigments include organic or inorganic extenders, flaky pigments, etc. Examples of thixotropy-imparting agents include silicone-based, castor oil-based, aliphatic amide wax, polyethylene oxide wax, and organic bentonite-based.

A curing accelerator can be used in the epoxy resin composition of the present invention as needed. For example, there are amines, imidazoles, organic phosphines, Lewis acids, etc. Specifically, 1,8-diazabicyclo(5,4,0)undecene-7, triethylenediamine, benzyldimethylamine, Tertiary amines such as triethanolamine, dimethylaminoethanol, and tris(dimethylaminomethyl)phenol, 2-methylimidazole, 2-phenylimidazole, 2-ethyl-4-methylimidazole, and 2-phenyl-4 -Imidazoles such as methylimidazole and 2-heptadecylimidazole, organic phosphines such as tributylphosphine, methyldiphenylphosphine, triphenylphosphine, diphenylphosphine, and phenylphosphine, tetra Tetra-substituted phosphonium, tetra-substituted borate such as phenylphosphonium, tetraphenyl borate, tetraphenylphosphonium, ethyltriphenyl borate, tetrabutylphosphonium, tetrabutylborate, 2-ethyl-4-methylimidazole, tetraphenyl There are tetraphenyl boron salts such as borate, N-methylmorpholine, and tetraphenyl borate. The addition amount is usually in the range of 0.01 to 5 parts by weight based on a total of 100 parts by weight of the resin components.

Additionally, if necessary, the epoxy resin composition of the present invention may contain mold release agents such as carnauba wax and OP wax, coupling agents such as γ-glycidoxypropyltrimethoxysilane, colorants such as carbon black, and flame retardants such as antimony trioxide. , low-stress agents such as silicone oil, and lubricants such as calcium stearate can be used.

The epoxy resin composition of the present invention can be made into a prepreg by dissolving an organic solvent into a varnish state, impregnating it with fibrous materials such as glass cloth, aramid nonwoven fabric, and polyester nonwoven fabric such as liquid crystal polymer, and then removing the solvent. there is. Additionally, in some cases, a laminate can be formed by applying it onto a sheet-like material such as copper foil, stainless steel foil, polyimide film, or polyester film.

When the epoxy resin composition of the present invention is heat-cured, it can be made into the cured resin product of the present invention. This cured product can be obtained by molding an epoxy resin composition using methods such as casting, compression molding, and transfer molding. The temperature at this time is usually in the range of 120 to 220°C.

Example

Hereinafter, the present invention will be described in detail through examples and comparative examples. However, the present invention is not limited to these. Unless otherwise specified, “part” represents a weight part and “%” represents weight%. In addition, the measurement method was each measured by the following method.

1) Epoxy equivalent

Using a potentiometric titrator, methyl ethyl ketone was used as a solvent, tetraethylammonium bromide acetic acid solution was added, and measurement was performed using a 0.1 mol/L perchloric acid-acetic acid solution using a potentiometric titrator.

2) melting point

The DSC peak temperature was determined using a differential scanning calorimeter (EXSTAR6000 DSC/6200 manufactured by SI Nanotechnology Co., Ltd.) under the condition of a temperature increase rate of 5°C/min. In other words, this DSC peak temperature was taken as the melting point of the resin.

3) Melt viscosity

It was measured at 150°C using a CAP2000H rotational viscometer manufactured by BROOKFIELD.

4) Yeonhwa point

It was measured by the circle method according to JIS-K-2207.

5) GPC measurement

A body (HLC-8220GPC, manufactured by Tosoh Corporation) equipped with columns (TSKgelG4000HXL, TSKgelG3000HXL, TSKgelG2000HXL, manufactured by Tosoh Corporation) in series was used, and the column temperature was set to 40°C. Additionally, tetrahydrofuran (THF) was used as the eluent, the flow rate was 1 mL/min, and a differential refractive index detector was used as the detector. For the measurement sample, 50 μL of 0.1 g of the sample was dissolved in 10 mL of THF and filtered through a microfilter. For data processing, GPC-8020 Model II version 6.00 manufactured by Tosoh Corporation was used.

6) Glass transition point (Tg)

Tg was determined using a thermomechanical measurement device (EXSTAR6000TMA/6100 manufactured by SI Nano Technology Co., Ltd.) under the condition of a temperature increase rate of 10°C/min.

7) 5% weight loss temperature (Td5), residual carbon rate

Using a thermogravimetric/differential thermal analysis device (EXSTAR6000TG/DTA6200 manufactured by SI Nanotechnology), the 5% weight loss temperature (Td5) was measured under nitrogen atmosphere and a temperature increase rate of 10°C/min. Additionally, the weight loss at 700°C was measured and calculated as the residual carbon rate.

8) Thermal conductivity

Thermal conductivity was measured by the abnormal hot wire method using an LFA447 type thermal conductivity meter manufactured by NETZSCH.

9) Melt mixability

Melt kneading properties were confirmed at 100°C. ○ Can be kneaded, △ Difficult to knead, × Contains non-melting ingredients

10) Solvent solubility

After weighing 2 g of resin and 2 g of methyl ethyl ketone in a sample bottle and heating and dissolving them, the temperature was gradually lowered in a constant temperature bath, and the temperature in the bath where the resin precipitated was measured. The higher the precipitation temperature (°C), the poorer the solvent solubility.

Example 1

Into a 1000 ml four-necked flask, 55.1 g of 4,4'-dihydroxybiphenyl, 121.2 g of diethylene glycol dimethyl ether, and 42.5 g of 4,4'-bischloromethylbiphenyl were charged and stirred under a nitrogen stream. The temperature was raised to 170°C and reaction was performed for 3 hours, and 23.6 g of 2,2'-dihydroxybiphenyl was further reacted to produce a polyvalent hydroxy resin. After completion of the reaction, 50.7 g of diethylene glycol dimethyl ether was recovered, 470 g of epichlorohydrin was added, and 68.7 g of a 48% aqueous sodium hydroxide solution was added dropwise at 62°C under reduced pressure (about 130 Torr) over 4 hours. During this time, the generated water was removed from the system by azeotropy with epichlorohydrin, and the spilled epichlorohydrin was returned to the system. After the dropwise addition was completed, the reaction was continued for an additional hour. After that, epichlorohydrin was distilled off, methyl isobutyl ketone was added, the salt was removed by washing with water, then filtered and washed with water, and then methyl isobutyl ketone was distilled off under reduced pressure to obtain 132 g of epoxy resin. obtained (epoxy resin A). The epoxy equivalent of this epoxy resin A was 198, the softening point was 87°C, the melt viscosity was 0.25 Pa·s, the hydrolyzable chlorine was 55 ppm, and the n=0 and m=0 components measured by GPC were 31%. The GPC chart of the obtained resin is shown in Figure 1. The ratio of n/(n+m) is 70 mol%.

Example 2

Except that the amount of 4,4'-dihydroxybiphenyl used was 65.6g, the amount of 2,2'-dihydroxybiphenyl used was set to 7.3g, and the amount of 4,4'-bischloromethylbiphenyl was set to 49.2g. The reaction was performed in the same manner as in Example 1, and 115 g of epoxy resin was obtained (epoxy resin B). The epoxy equivalent of this epoxy resin B was 208, the softening point was 85°C, the melt viscosity was 0.56 Pa·s, the hydrolyzable chlorine was 70 ppm, and the n=0 and m=0 components measured by GPC were 34%. The ratio of n/(n+m) is 90 mol%.

Example 3

The amount of 4,4'-dihydroxybiphenyl used was 65.3g, and instead of 2,2'-dihydroxybiphenyl, dihydroxydiphenylmethane (4,4'-dihydroxydiphenylmethane: 36.2%, 2,4'-dihydroxydiphenylmethane: 46.6%, 2,2'-dihydroxydiphenylmethane: 17.2%) in a dosage of 7.8g and 4,4'-bischloromethylbiphenyl 49.0g. Otherwise, the reaction was carried out in the same manner as in Example 1, and 120 g of epoxy resin was obtained (epoxy resin C). The epoxy equivalent of this epoxy resin B was 210, the softening point was 90°C, the melt viscosity was 0.53 Pa·s, the hydrolyzable chlorine was 77 ppm, and the n=0 and m=0 components measured by GPC were 23%. The ratio of n/(n+m) is 90 mol%.

Reference example 1

In a 1000 ml four-necked flask, 55.1 g of 4,4'-dihydroxybiphenyl, 23.6 g of 2,2'-dihydroxybiphenyl, 121.2 g of diethylene glycol dimethyl ether, and 4,4'-bischloromethyl ratio. 42.5 g of phenyl was charged, the temperature was raised to 170°C with stirring under a nitrogen stream, and reaction was carried out for 10 hours to produce a polyvalent hydroxy resin. After completion of the reaction, 50.7 g of diethylene glycol dimethyl ether was recovered, 470 g of epichlorohydrin was added, and 68.7 g of 48% sodium hydroxide aqueous solution was added dropwise at 62°C under reduced pressure (about 130 Torr) over 4 hours. During this time, the generated water was removed from the system by azeotropy with epichlorohydrin, and the spilled epichlorohydrin was returned to the system. After the dropwise addition was completed, the reaction was continued for an additional hour. After that, epichlorohydrin was distilled off, methyl isobutyl ketone was added, the salt was removed by washing with water, filtered and washed with water, and then methyl isobutyl ketone was distilled off under reduced pressure to obtain 130 g of epoxy resin. obtained (epoxy resin D). The epoxy equivalent of this epoxy resin A was 196, the softening point was 97°C, the melt viscosity was 0.18 Pa·s, the hydrolyzable chlorine was 65 ppm, and the n=0 and m=0 components measured by GPC were 28%. The ratio of n/(n+m) is 70 mol%.

Reference example 2

77.5 g of 4,4'-dihydroxybiphenyl, 180.8 g of diethylene glycol dimethyl ether, and 52.3 g of 4,4'-bischloromethylbiphenyl were added, and the temperature was raised to 170°C while stirring under a nitrogen stream for 2 hours. reacted. After the reaction, 123 g of diethylene glycol dimethyl ether was recovered, 385.4 g of epichlorohydrin was added, and 69.4 g of 48% sodium hydroxide aqueous solution was added dropwise at 62°C under reduced pressure (about 130 Torr) over 4 hours. In the same manner as in 1, 129 g of epoxy resin was obtained (epoxy resin E). The epoxy equivalent of this epoxy resin C was 196, the melting point was 126°C, the melt viscosity was 0.68 Pa·s, the hydrolyzable chlorine was 390 ppm, and the n=0 and m=0 components measured by GPC were 24%. The ratio of n/(n+m) is 100 mol%.

Examples 4 to 6 and Comparative Examples 1 to 3

As the epoxy resin component, epoxy resin A obtained in Example 1, epoxy resin B obtained in Example 2, epoxy resin C obtained in Example 3, epoxy resin D obtained in Reference Example 1, epoxy resin E obtained in Reference Example 2, An epoxy resin composition was obtained using epoxy resin F and epoxy resin G, using phenol novolak resin as a curing agent, and triphenylphosphine as a curing accelerator, using the formulations shown in Table 2. The numbers in the table represent parts by weight in the formulation.

Using this epoxy resin composition, it was molded at 175°C, post-cured at 175°C for 5 hours to obtain a cured product test piece, and then used for measuring various physical properties.

The epoxy resin, curing agent, and curing accelerator used are shown below.

Epoxy Resin F; Phenol novolac type epoxy resin (epoxy equivalent weight 175, content of m = 1 component by GPC measurement is 9.0%, m = 2 components; 37.7%, m = 3 components; 17.1%, m) represented by the following formula (6) =4 components; 8.2%, and the total content of m=5 components or more is 27.9%.)

Here, m represents a number from 0 to 20, and G represents a glycidyl group.

Epoxy resin G; o-cresol novolac type epoxy resin (YDCN-700-3 manufactured by Nittetsu Chemical & Materials, epoxy equivalent 200)

hardener; Phenol novolac resin (hydroxyl equivalent weight 105, softening point 67°C)

curing accelerator; Triphenylphosphine

As is clear from these results, the epoxy resin obtained in the examples has excellent melt kneading properties and solvent solubility, the cured product has good thermal stability, and since a reduction in residual carbon rate is confirmed, improvement in tracking resistance can be expected. there is. Additionally, since it has good thermal conductivity, it is suitable for power devices and vehicle applications.

The epoxy resin of the present invention is useful for applications such as lamination, molding, molding, and adhesion, and is suitable for sealing electrical and electronic components, circuit board materials, etc.

Claims (5)

An epoxy resin represented by the following general formula (1), wherein the epoxy equivalent weight is 180 to 240 g/eq and the softening point is in the range of 60 to 95°C.

In the formula, G represents a glycidyl group, and A represents a single bond, an oxygen atom, a sulfur atom, -SO ₂ -, -CO-, or a divalent hydrocarbon having 1 to 6 carbon atoms. n and m each independently represent numbers from 0 to 20. According to claim 1,
An epoxy resin characterized in that the component with n = 0 and m = 0 is 35% or less in area % (GPC area %) measured by gel permeation chromatography. After reacting 4,4'-dihydroxybiphenyl represented by formula (2) with an aromatic crosslinking agent represented by formula (3), a difunctional phenolic compound represented by formula (4) is further reacted to obtain the general formula A production method characterized in that the epoxy resin according to claim 1 or 2 can be obtained by obtaining the polyhydric hydroxy resin represented by (5) and reacting the polyhydric hydroxy resin with epichlorohydrin.


Here, X represents a hydroxyl group, a halogen atom, or an alkoxy group having 1 to 6 carbon atoms.

Here, A represents a single bond, an oxygen atom, a sulfur atom, -SO ₂ -, -CO-, or a divalent hydrocarbon having 1 to 6 carbon atoms.

Here, A represents a single bond, an oxygen atom, a sulfur atom, -SO ₂ -, -CO-, or a divalent hydrocarbon having 1 to 6 carbon atoms, and at least one is other than a single bond. n and m each independently represent numbers from 0 to 20. An epoxy resin composition comprising the epoxy resin according to claim 1 or 2 and a curing agent as essential components. A cured epoxy resin product obtained by curing the epoxy resin composition according to claim 4.