WO2015052925A1

WO2015052925A1 - Method for producing epoxy resin, epoxy resin, curable resin composition, and cured product

Info

Publication number: WO2015052925A1
Application number: PCT/JP2014/005115
Authority: WO
Inventors: 政隆中西; 知樹藤田; 喜裕今; 佐藤　一彦
Original assignee: 日本化薬株式会社; 独立行政法人産業技術総合研究所
Priority date: 2013-10-09
Filing date: 2014-10-07
Publication date: 2015-04-16
Also published as: JPWO2015052925A1; TWI621636B; JP6440207B2; TW201520239A

Abstract

The objective of the present invention is to provide a method for producing an epoxy resin, the method being capable of efficiently converting a carbon-carbon double bond of an allyl group of a specific allyl ether compound to an epoxy group, in other words, the method having a high yield of epoxy groups. This method for producing an epoxy resin comprises a step of reacting a compound represented by formula (I) (In the formula, n is an average value of the number of repetitions of 1 to 20) and a hydrogen peroxide in the presence of a tungstic acid compound, a quarternary ammonium salt, a cation exchange resin and a phosphate compound.

Description

Epoxy resin production method, epoxy resin, curable resin composition, and cured product

The present invention relates to an epoxy resin production method, an epoxy resin, a curable resin composition, and a cured product.

Epoxy resins are used in various fields such as electrical / electronic parts, structural materials, adhesives, paints, etc. Especially, epoxy resins having a repeating unit of the following formula (II) have recently been excellent in their difficulty. Widely used due to its flame resistance, adhesion, water resistance, etc.

As a method for producing an epoxy resin containing such a repeating unit, for example, as described in Patent Document 1, epichlorohydrin is reacted with a compound containing a repeating unit having a biphenyl skeleton and a phenolic hydroxyl group, to form a hydroxyl group. Conventionally, a method for producing a glycidyl ether group is used.

On the other hand, in recent years, in the field of electrical and electronic parts, gold wires used for wire bonding that connects IC chips to lead frames and printed circuit boards are rapidly changing from the viewpoint of cost reduction. It is out. Here, when an epoxy resin manufactured by a technique using a chlorine-containing compound (epichlorohydrin) as described above is used as a semiconductor sealing material using a copper wire, copper remaining due to chlorine remaining in the epoxy resin. There was a problem that the wire was corroded. In order to prevent such corrosion due to chlorine, it is effective to use an epoxy resin obtained by a technique not using a chlorine-containing compound. As a technique for producing an epoxy resin without using a chlorine-containing compound, for example, Patent Document 2 reports a method of producing a bifunctional epoxy resin by reacting hydrogen peroxide with a compound having a carbon-carbon double bond. Has been.

JP-A-8-208802 JP 2011-225711 A

Therefore, the present inventors independently have the following formula (I):

An attempt was made to produce an epoxy resin having a repeating unit of the above formula (II) by epoxidation of the conventional carbon-carbon double bond described in Patent Document 2 with hydrogen peroxide using the compound represented by However, it was found that the generation rate of epoxy groups is not sufficiently satisfactory.

The present invention has been made in view of the above situation, and can efficiently convert the carbon-carbon double bond of the allyl group of a specific allyl ether compound into an epoxy group, that is, an epoxy group. An object of the present invention is to provide a method for producing an epoxy resin having a high production rate.
Another object of the present invention is to provide a novel epoxy resin.
Furthermore, an object of this invention is to provide the curable resin composition using the said epoxy resin, and the hardened | cured material formed by hardening | curing the said curable resin composition.

The gist configuration of the present invention for achieving the above object is as follows.

[1] In the presence of a tungstic acid compound, a quaternary ammonium salt, a cation exchange resin, and a phosphoric acid compound, the following formula (I):

(In the formula, n represents an average value of the number of repetitions of 1 to 20)
A process for producing an epoxy resin, comprising a step of reacting a compound represented by formula (II) with hydrogen peroxide.

[2] The production of the epoxy resin according to [1], wherein the amount of the cation exchange resin used is 1 to 10 parts by mass per 100 parts by mass of the compound represented by the formula (I). Method.

[3] The step [1] or [3], wherein the step of reacting the compound represented by the formula (I) with hydrogen peroxide is performed in a three-phase system of an organic phase, an aqueous phase, and a solid phase. 2] The manufacturing method of the epoxy resin of description.

[4] Formula (II) below:

And the following formula (III):

Containing repeating units of
An epoxy resin in which the average value L of the number of allyl groups in one molecule and the average value M of the number of epoxy groups in one molecule satisfy a relationship of 0 <L / M ≦ 0.1.

[5] A curable resin composition comprising the epoxy resin according to the above [4] and a curing agent.

[6] A cured product obtained by curing the curable resin composition according to [5].

ADVANTAGE OF THE INVENTION According to this invention, the carbon-carbon double bond of the allyl group of a specific allyl ether compound can be efficiently converted into an epoxy group, that is, a method for producing an epoxy resin with a high epoxy group production rate is provided. can do.
Moreover, according to this invention, a novel epoxy resin can be provided.
Furthermore, according to this invention, the hardened | cured material formed by hardening | curing the curable resin composition using the said epoxy resin and the said curable resin composition can be provided.

It is an example of the measurement result of the high performance liquid chromatography of AEP (allyl ether resin). It is another example of the measurement result of the high performance liquid chromatography of AEP (allyl ether resin).

Hereinafter, the present invention will be specifically described with reference to embodiments thereof.
In the present invention, the conversion rate means the ratio (%) of the allyl group lost from the compound represented by the formula (I) by the epoxidation reaction, and the selectivity means the formula (I ) Is the ratio (%) of the allyl group carbon-carbon double bond that has disappeared from the compound represented by the formula (I), which is selectively converted to an epoxy group. The ratio (%) of the allyl group carbon-carbon double bond converted to an epoxy group in the compound represented by

<Method for producing epoxy resin>
The method for producing an epoxy resin of the present invention comprises the following formula (I): in the presence of a tungstic acid compound, a quaternary ammonium salt, a cation exchange resin, and a phosphoric acid compound.

(In the formula, n represents an average value of the number of repetitions of 1 to 20)
And a step of reacting hydrogen peroxide with a compound represented by the formula: Here, n is preferably 1 to 10, more preferably 2 to 8, and particularly preferably 2 to 4.

(Compound represented by formula (I))
The compound represented by formula (I) (allyl ether resin, hereinafter referred to as AEP as appropriate) used as a raw material in the method for producing an epoxy resin of the present invention is a corresponding phenol resin (phenol-biphenylene novolak). Resin) and allyl halide are reacted in a solvent in the presence of a base.

((Method of manufacturing AEP))
[Phenolic resin]
Examples of the phenol resin used in the production of AEP include a reaction product of phenol and 4,4′-bis (chloromethyl) -1,1′-biphenyl, phenol and 4,4′-bis (methoxymethyl) -1, A reaction product with 1′-biphenyl is preferred.

[Allyl halide]
The allyl halide used for the production of AEP is preferably allyl chloride from the viewpoint of reactivity with the phenol resin.
Here, although allyl chloride tends to polymerize and form a polymer (polyallyl chloride), allyl chloride used for the production of AEP is preferably one having a low polyallyl chloride content. .
When the content ratio of polyallyl chloride in the allyl chloride used is large, not only becomes a factor to increase the total chlorine content of the obtained AEP, and also the epoxy resin obtained by the production method of the present invention using the AEP, AEP, And it contributes to the increase in the molecular weight of the epoxy resin obtained, and there is a possibility that a very small amount of gel is left at the time of commercialization. Further, in order to reduce the amount of chlorine, it is necessary to add a considerable amount of a basic substance, which is not preferable industrially, and there is a possibility that highly toxic allyl alcohol is produced in the system.

The content ratio of these polyallyl chlorides can be easily confirmed by gas chromatography or the like. The specific content ratio of polyallyl chloride is the area ratio when measured by gas chromatography. On the other hand, it is preferably 1 area% or less, more preferably 0.5 area% or less, and particularly preferably 0.2 area% or less.

In the production of AEP, the amount of allyl halide such as allyl chloride used is usually 1.0 to 1.15 molar equivalents, preferably 1.0 to 1.10 molar equivalents, based on 1 molar equivalent of the hydroxyl group of the phenol resin. More preferably, it is 1.0 to 1.05 molar equivalent.

[base]
The base used for the production of AEP is preferably an alkali metal hydroxide, and specific examples thereof include sodium hydroxide and potassium hydroxide. Such an alkali metal hydroxide may be used in the form of a solid or in the form of an aqueous solution thereof. In particular, the alkali metal hydroxide was formed into a flake shape from the viewpoint of solubility in a solvent and handling. It is preferable to use it in a solid state.

In the production of AEP, the use amount of a base such as an alkali metal hydroxide is usually 1.0 to 1.15 mole equivalent, preferably 1.0 to 1.10, relative to 1 mole equivalent of the hydroxyl group of the phenol resin. The molar equivalent, more preferably 1.0 to 1.05 molar equivalent.

[solvent]
The solvent used for the production of AEP preferably contains an aprotic polar solvent, and more preferably contains water and an aprotic polar solvent. When the solvent used for the production of AEP contains an aprotic polar solvent, the solubility of the phenol resin in the solvent can be improved. Examples of such aprotic polar solvents include dimethyl sulfoxide, N-methylpyrrolidone, dimethylacetamide, dioxane and the like, and dimethyl sulfoxide is particularly preferable.
In the production of AEP, the amount of an aprotic polar solvent such as dimethyl sulfoxide used is preferably 20 to 300% by mass, more preferably 25 to 250% by mass, particularly preferably 25 to 200%, based on the total mass of the phenol resin. % By mass. Aprotic polar solvents such as dimethyl sulfoxide are not useful for purification such as washing with water, and have a high boiling point and are difficult to remove. Therefore, the amount used is more than 300% by mass with respect to the total mass of the phenol resin. It is not preferable.

The solvent used for the production of AEP may contain an alcohol having 1 to 5 carbon atoms in addition to the water and the aprotic polar solvent described above.
The solvent used for the production of AEP may contain an organic solvent other than the above-mentioned aprotic polar solvent and an alcohol having 1 to 5 carbon atoms (other organic solvents) such as methyl ethyl ketone, methyl isobutyl ketone and toluene. The amount of other organic solvent used is preferably 100% by mass or less, more preferably 0.5 to 50% by mass, based on the amount of aprotic polar solvent used. Excessive use of methyl ethyl ketone, methyl isobutyl ketone, toluene, etc. causes a Claisen transition during the reaction, resulting in an increase in residual phenolic hydroxyl groups resulting in a shortage of allyl chloride in the system, and other than the intended structure May occur, and the phenolic hydroxyl groups may not be allyl etherified.

[Reaction conditions, etc.]
In the production of AEP, the reaction temperature of the allyl etherification reaction of the phenol resin is usually 30 to 90 ° C., preferably 35 to 80 ° C. In order to obtain AEP with higher purity, it is preferable to increase the reaction temperature in two or more stages. For example, the first stage is 35 to 50 ° C., and the second stage is 45 to 70 ° C. It is particularly preferred.
The reaction time for the allyl etherification reaction of the phenol resin is usually 0.5 to 10 hours, preferably 1 to 8 hours, particularly preferably 1 to 5 hours. When the reaction time is 0.5 hours or longer, the reaction proceeds sufficiently, and when it is 10 hours or shorter, the amount of by-products generated can be kept low.
After completion of the reaction, the solvent is distilled off under reduced pressure by heating to obtain the product. The recovered product is dissolved in a ketone compound having 4 to 7 carbon atoms (for example, methyl isobutyl ketone, methyl ethyl ketone, cyclopentanone, cyclohexanone, etc.) and 40 ° C to 90 ° C, more preferably 50 to 80 ° C. Wash with water until the water layer has a pH of 5-8. By washing with water until the pH of the aqueous layer is less than 8, it is possible to prevent the balance of the catalyst system from being lost and the progress of the reaction from being suppressed during the subsequent epoxidation reaction.
The allyl etherification reaction of the phenol resin is usually carried out while blowing an inert gas such as nitrogen into the system (in the air or in the liquid). By carrying out the reaction while blowing an inert gas into the system, the resulting product can be prevented from being colored.
The amount of inert gas blown per unit time depends on the volume of the kettle used for the reaction. For example, the amount of inert gas blown per unit time so that the volume of the kettle can be replaced in 0.5 to 20 hours. Is preferably adjusted.

[Properties of AEP]
When the product containing AEP obtained from the above reaction was measured by high performance liquid chromatography (HPLC), the spectrum showed an AEP peak where n = 1 in the formula (I), and n = 2. In some cases, an impurity peak is observed between the AEP peak and the AEP peak.
From the viewpoint of reactivity when epoxidizing AEP, the peak amount of this impurity is less than 1.5 area%, particularly less than 1.0 area%, in terms of area ratio, with respect to the entire product containing AEP. It is preferable that When this area ratio exceeds 2.0 area%, there is a possibility of greatly affecting the progress of the epoxidation reaction.
For more specific explanation, FIGS. 1 and 2 show the HPLC data of the product containing AEP. The three large peaks confirmed at about 31 minutes correspond to the AEP with n = 1 in the formula (I), and the three large peaks confirmed at around 35 minutes (shoulder peaks are visible but one Corresponds to an AEP in which n = 2. In FIG. 1, an impurity peak is observed in the vicinity of 32 to 34 minutes therebetween. The presence of this peak is undesirable because it adversely affects the subsequent epoxidation of AEP. On the other hand, in FIG. 2, a large peak is not observed in this range, which is preferable.

The AEP used in the method for producing an epoxy resin of the present invention preferably has a softening point of 120 ° C. or lower. If the softening point of AEP exceeds 120 ° C, it will be very difficult to dissolve in a solvent, and it will be difficult to remove the salt contained in AEP by washing, etc., especially in fields where electrical reliability is required. Not preferred due to concerns.

(Tungstic acid compound)
The method for producing an epoxy resin of the present invention is performed in the presence of a tungstic acid compound. In the present invention, the tungstic acid compound is not particularly limited as long as it is a compound that generates tungstate ion (WO ₄ ²⁻ ) in water. For example, tungstic acid, tungsten trioxide, phosphotungstic acid, ammonium tungstate, tungstic acid Examples include potassium dihydrate and sodium tungstate dihydrate. Among these, tungstic acid, tungsten trioxide, phosphotungstic acid, and sodium tungstate dihydrate are preferable from the viewpoint of improving the production rate of epoxy groups. These tungstic acid compounds may be used alone or in combination of two or more. The amount of the tungstic acid compound used is preferably 1 × 10 ⁻⁶ to 0.2 mol per mol of the compound represented by the formula (I) from the viewpoint of improving the production rate of the epoxy group, and is 0.0001 to 0 More preferred is 2 moles.

(Quaternary ammonium salt)
The method for producing the epoxy resin of the present invention is carried out in the presence of a quaternary ammonium salt. In the present invention, the quaternary ammonium salt is not particularly limited as long as it functions as a phase transfer catalyst. The quaternary ammonium salt is composed of a quaternary ammonium cation and an anion.

The quaternary ammonium cation constituting the quaternary ammonium salt is not particularly limited, but is tridecanylmethylammonium cation, dilauryldimethylammonium cation, trioctylmethylammonium cation, dioctyldecanylmethylammonium cation, didecanyloctylmethyl. Ammonium cation, trihexadecylmethylammonium cation, trimethylstearylammonium cation, tetrapentylammonium cation, cetyltrimethylammonium cation, benzyltributylammonium cation, dicetyldimethylammonium cation, tricetylmethylammonium cation, di-cured tallow alkyldimethylammonium cation, etc. Is mentioned.

Among these, in order to improve the balance between hydrophobicity and hydrophilicity, those having 16 to 100 carbon atoms in the quaternary ammonium cation are preferable, and those having 25 to 100 are more preferable. And it is preferable that the carbon chain couple | bonded with the nitrogen atom of this cation is an aliphatic chain. Examples of the quaternary ammonium cation having 25 to 100 carbon atoms in the quaternary ammonium cation and the carbon chain bonded to the nitrogen atom being an aliphatic chain include tridecanylmethylammonium cation, dilauryldimethylammonium cation, Examples include trioctylmethylammonium cation, dioctyldecanylmethylammonium cation, didecanyloctylmethylammonium cation, trihexadecylmethylammonium cation, dicetyldimethylammonium cation, and tricetylmethylammonium cation. The carbon chain bonded to the nitrogen atom is preferably a straight aliphatic chain.

The anion constituting the quaternary ammonium salt is not particularly limited, but halide ion (chloride ion, bromide ion, iodide ion, etc.), nitrate ion, sulfate ion, methyl sulfate ion, hydrogen sulfate ion, acetate ion, Examples include anions such as formate ion and carbonate ion, and among these, sulfate ion, methyl sulfate ion, hydrogen sulfate ion, acetate ion, formate ion and carbonate ion are preferable from the viewpoint of improving the production rate of epoxy group. Particularly preferred are acetate ion, formate ion, carbonate ion, methyl sulfate ion, and hydrogen sulfate ion.

That is, the quaternary ammonium salt used in the present invention is preferably, for example, trioctylmethylammonium acetate (TOMAA), trioctylmethylammonium hydrogensulfate, or trioctylmethylammonium sulfate methyl salt from the above-mentioned viewpoint.

The amount of the quaternary ammonium salt used is preferably from 0.01 to 0.5 mol, preferably from 0.05 to 0.001 mol per mol of the compound represented by the formula (I), from the viewpoint of improving the production rate of the epoxy group. 3 moles is more preferred.

(Cation exchange resin)
The method for producing an epoxy resin of the present invention is performed in the presence of a cation exchange resin. When the production method of the present invention is carried out in the presence of a cation exchange resin, the production rate of epoxy groups can be greatly improved. This is presumably because the pH is locally lowered around the cation exchange resin, and the reactivity of the reaction from a carbon-carbon double bond to an epoxy group, which exhibits high efficiency in strong acidity, is particularly increased. The Moreover, if the pH of the entire aqueous phase of the reaction system is too low, there is a demerit that the epoxy group is decomposed by hydrolysis and the production rate of the epoxy group is lowered, but the production method of the present invention using a cation exchange resin Can locally create a low pH environment around the resin, reducing the high molecular weight due to decomposition of the generated epoxy groups by water addition and polymerization of the epoxy groups due to too low pH as described above It is inferred that it is advantageous in that it can be done.

In the present invention, the cation exchange resin may be a strong acid cation exchange resin or a weak acid cation exchange resin. From the viewpoint of improving the production rate of epoxy groups, a strong acid cation exchange resin may be used. Resins are preferred. As a strongly acidic cation exchange resin, a small amount of divinylbenzene is copolymerized with a polymerized styrene to form a three-dimensional network structure, and a strongly acidic group such as a sulfonic acid group (—SO ₃ H) is introduced into this. A porous type (MR type) cation exchange resin may be mentioned.
Examples of commercially available cation exchange resins that can be used in the present invention include strongly acidic ion exchanges such as Amberlyst (registered trademark) 15DRY, 15JWET, 16WET, 31WET, 35WET, and A21 sold by Organo in Japan. Resin, DUOLITE (registered trademark) C20J, C20LF, C255LFH, C26A, C26TRH and other strongly acidic ion exchange resins sold by Sumika Chemtex in Japan, weakly acidic ion exchange resins such as DUOLITE C433LF and C476, Mitsubishi Diaion (registered trademark) SK series (gel type), UBK series (gel type uniform particle size), PK series (porous type), HPK25 / RCP series (high porous type), and UBK500 series for chromatographic separation , Etc. In the production method of the present invention, since a cation exchange resin is contained in the reaction system, the step of reacting the compound represented by the formula (I) with hydrogen peroxide includes an organic phase, an aqueous phase, It is performed in a three-phase system of a solid phase (cation exchange resin).

The amount of the cation exchange resin used is preferably 1 to 10 parts by mass and preferably 2 to 5 parts by mass per 100 parts by mass of the compound represented by the formula (I) from the viewpoint of improving the production rate of the epoxy group.

(Phosphate compound)
The manufacturing method of the epoxy resin of this invention is performed in presence of a phosphoric acid compound. The phosphate compound is not particularly limited as long as it is a compound that generates phosphate ions (PO ₄ ³⁻ ) in water. For example, phosphoric acid, alkali metal dihydrogen phosphate, alkaline earth metal dihydrogen phosphate Salt, hydrogen phosphate di-alkaline metal salt, hydrogen phosphate di-alkaline earth metal salt, alkali phosphate metal phosphate, alkaline earth metal phosphate, polyphosphoric acid, alkali metal polyphosphate, alkaline earth metal polyphosphate , Tripolyphosphoric acid, alkali metal tripolyphosphate, alkaline earth metal tripolyphosphate, etc. Among these, salts such as phosphoric acid, disodium hydrogen phosphate, sodium dihydrogen phosphate, sodium phosphate are included. The product to be obtained is preferable because it is easy to obtain.

The amount of the phosphoric acid compound used is preferably 0.01 to 1.0 mol per mol of the compound represented by the formula (I) from the viewpoint of improving the production rate of the epoxy group, preferably 0.05 to 0.5 Mole is more preferred.

(hydrogen peroxide)
In the production method of the present invention, the hydrogen peroxide to be reacted with the compound represented by the formula (I) is not particularly limited, but it is usually dissolved in water and added as a hydrogen peroxide solution. The concentration of hydrogen peroxide in the hydrogen peroxide water is not particularly limited, but the hydrogen peroxide concentration is preferably 10 to 40% by mass for ease of handling. The amount of aqueous hydrogen peroxide used is not particularly limited, but the amount of hydrogen peroxide is preferably 0.3 to 10 molar equivalents relative to 1 molar equivalent of the allyl group of the compound represented by formula (I). More preferred is 1 to 5 molar equivalents. The amount of hydrogen peroxide solution is 0.3 molar equivalent or more with respect to 1 molar equivalent of the allyl group of the compound represented by the formula (I), so that epoxidation can be advanced efficiently and 10 molar equivalent. By being below, the hydrolysis of the epoxy group to produce | generate can be suppressed.

The production method of the epoxy resin of the present invention is not particularly limited, but toluene, xylene, mesitylene, 1,2-dichlorobenzene, trichloromethane, ethyl acetate, dichloroethane and the like in which the compound represented by the formula (I) can be dissolved. After adding a compound represented by the above formula (I), a tungstic acid compound, a quaternary ammonium ion salt, a cation exchange resin, and a phosphoric acid compound to an organic solvent, an aqueous hydrogen peroxide solution is added, followed by epoxy. It is preferable to initiate the reaction. However, the production method of the present invention is not limited to this addition order, and in the presence of a tungstic acid compound, a quaternary ammonium salt, a cation exchange resin, and a phosphoric acid compound, the formula ( Conversion of the carbon-carbon double bond in the allyl group of the compound represented by I) to an epoxy group can be performed efficiently.

In the method for producing an epoxy resin of the present invention, the reaction temperature during epoxidation is not particularly limited, but is preferably 10 to 120 ° C, and more preferably 25 to 100 ° C. By being 10 degreeC or more, reaction rate can be made suitable, and the hydrolysis reaction of the produced | generated epoxy group can be suppressed by being 120 degreeC or less.

In the method for producing an epoxy resin of the present invention, the reaction time depends on the amount of the reaction temperature catalyst and the like, but in order to ensure a sufficient time for epoxidation to proceed and to produce industrially efficiently, After adding a fixed amount of hydrogen peroxide solution, it is preferably 1 to 48 hours, more preferably 3 to 36 hours, and particularly preferably 4 to 24 hours.

After the reaction, quench the excess hydrogen peroxide. Examples of the method for quenching hydrogen peroxide include a method using a reducing agent and a method using a basic compound. In the present invention, it is preferable to perform both of them. Specifically, it is preferable to quench the hydrogen peroxide by adding a reducing agent after adjusting the pH of the aqueous phase to 6 to 11 with a basic compound. By setting the pH to 6 or more, it is possible to prevent the generated epoxy group from being hydrolyzed by suppressing heat generation during the reduction, and even to set the pH to 11 or less can prevent hydrolysis of the generated epoxy group. it can. About the kind and quantity of a reducing agent and a basic compound, the thing similar to what is described in Unexamined-Japanese-Patent No. 2011-225711 can be used in the same range, respectively.

Next, after quenching with hydrogen peroxide, the organic phase is separated from the aqueous phase and solid phase (cation exchange resin). At this time, if the organic phase and the aqueous phase do not separate well, the organic solvent used for the reaction is further added, and the reaction product is extracted from the aqueous phase. Moreover, solid content is isolate | separated by methods, such as filtration, a decantation, and centrifugation. The separated organic phase is purified by washing with water as necessary. The separation operation may be performed before the hydrogen peroxide quenching process.

From the obtained organic phase, impurities (for example, residual quaternary ammonium salt) are removed by a known treating agent such as composite metal salt, activated carbon, clay mineral, phenol-formaldehyde resin, metal oxide, and the like. After further washing with water, filtration and the like, the target epoxy resin is obtained by distilling off the solvent. As the composite metal salt, activated carbon, clay mineral, and phenol-formaldehyde resin, for example, those described in JP-A-2011-225711 can be used. By performing purification with these treatment agents, the purification step by distillation or the like can be reduced, and the target epoxy resin can be taken out with high yield.

By using the method for producing an epoxy resin of the present invention, the carbon-carbon double bond of the allyl group of the compound represented by the formula (I) can be efficiently converted into an epoxy group. In other words, according to the method for producing an epoxy resin of the present invention, the carbon-carbon double bond of the allyl group in the compound represented by the formula (I) can be reacted at a high conversion rate. The selectivity is high, that is, an epoxy group can be obtained with a high production rate.

<Epoxy resin>
The epoxy resin of the present invention can be obtained by the method for producing the epoxy resin of the present invention, and has the following formula (II):

A repeating unit of the following formula (III):

Containing repeating units of
It is an epoxy resin in which the average value L of the number of allyl groups in one molecule and the average value M of the number of epoxy groups in one molecule satisfy the relationship of 0 <L / M ≦ 0.1.

The average value L of the number of allyl groups in one molecule and the average value M of the number of epoxy groups in one molecule can be determined by ¹ H-NMR measurement. L, M, and L / M have the following relationship with the conversion rate (%) and the generation rate (%) used in the evaluation of the above-described method for producing the epoxy resin of the present invention.

L = (100−conversion / 100) × (n + 1)
M = (Production rate / 100) × (n + 1)
L / M = (100-conversion rate) / production rate)
In the above formula, n is an average value of the number of repetitions of the compound represented by formula (I) used as a raw material in the above-described method for producing an epoxy resin of the present invention.

Since the epoxy resin of the present invention is obtained by the above-described method for producing the epoxy resin of the present invention, the average value (n) of the number of all repeating units in one molecule is 1 to 20, It is preferably 10, more preferably 2 to 8, and particularly preferably 2 to 4. The value obtained by adding the average value (o) of the number of repeating units of formula (II) in one molecule and the average value (p) of the number of repeating units of formula (III) in one molecule is n. Is preferred. In such a case, the repeating unit of the epoxy resin of the present invention is composed only of the repeating unit of the above formula (II) and the repeating unit of the above formula (III). Moreover, the average value (o) of the number of repeating units of the formula (II) in one molecule is 80% or more and less than 100% with respect to the average value (n) of the number of all repeating units in one molecule. The average value (p) of the number of repeating units of formula (III) in one molecule is more than 0% and less than 20% with respect to the average value (n) of all repeating units in one molecule. It is preferable.

The terminal of the epoxy resin of the present invention preferably has a hydrogen atom, the structure of the following formula (IV) or formula (V), and the epoxy resin is adjacent to the repeating unit of formula (II) or formula (III). Is present, the benzene ring side terminal is preferably a hydrogen atom, and the methylene group (—CH ₂ —) side terminal has a structure of the following formula (IV) or formula (V): It is preferable.

Since the epoxy resin of the present invention is excellent in flame retardancy, it can produce a composition that can exhibit flame retardancy without adding halogen as a flame retardant, and has little addition to the environment. In addition, due to its high hydrophobicity, even if ions such as chlorine are contained, their movement can be suppressed, and it has high electrical reliability and is useful as an electrical / electronic component material.

<Curable resin composition>
The curable resin composition of the present invention contains the epoxy resin and a curing agent. As the curing agent used in the curable resin composition of the present invention, for example, known curing agents such as amine compounds, acid anhydride compounds, amide compounds, and phenol compounds can be used. Examples thereof include those described in International Publication No. 2006/090662.

In the curable resin composition of the present invention, the amount of the curing agent used is preferably 0.5 to 1.5 molar equivalents relative to 1 molar equivalent of the epoxy group of the epoxy resin of the present invention, and preferably 0.6 to 1.2. A molar equivalent is particularly preferred. Good hardened | cured material properties can be obtained because the usage-amount of a hardening | curing agent is said range.

The curable resin composition of the present invention includes, for example, various blends of known curing accelerators, inorganic fillers, silane coupling agents, release agents, pigments and the like described in International Publication No. 2006/090662. An agent, various thermosetting resins, and other additives may be appropriately contained. The curable resin composition of the present invention can be obtained by uniformly mixing the above components. The curable resin composition of this invention can be used for various uses, such as an adhesive agent, a coating material, and a coating agent, for example.

<Hardened product>
The cured product of the present invention is obtained by curing the curable resin composition of the present invention. As a curing method, a known method can be used, and the cured product of the present invention obtained by curing can be used for various applications such as an insulating material for printed circuit boards and a semiconductor sealant. it can.

Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. In Examples and Comparative Examples, the conversion rate, selectivity, production rate, and L / M were determined by the following methods.

<Conversion rate, selectivity, production rate>
The conversion rate, selectivity and production rate were calculated by ¹ H-NMR measurement (solvent: CDCl ₃ , internal standard substance: naphthalene) according to the following formula based on the obtained data. The first decimal place of each calculated value was rounded off to obtain the conversion rate, selectivity, and production rate, respectively.

Conversion (%) = (1−average number of allyl groups remaining in one molecule of the obtained epoxy resin / average number of allyl groups in one AEP molecule before reaction) × 100
Selectivity (%) = {average value of the number of epoxy groups present in one molecule of the obtained epoxy resin / (average value of the number of allyl groups in one molecule of the AEP before the reaction−one molecule of the obtained epoxy resin) Average value of the number of allyl groups remaining therein}} × 100
Production rate (%) = conversion rate × selectivity / 100

<L / M>
The “average value of the number of allyl groups remaining in one molecule of the obtained epoxy resin” (that is, L) obtained by the above ¹ H-NMR measurement is expressed as “the epoxy group present in one molecule of the obtained epoxy resin”. It was obtained by dividing by the “average value of the numbers” (ie, M).

[Synthesis of AEP]
A flask equipped with a stirrer, a reflux condenser, and a stirrer was charged with 40 parts by mass of water, 400 parts by mass of dimethyl sulfoxide, phenol resin (phenol-biphenylene type hydroxyl equivalent 210 g / eq. Softening point 74 ° C.) 210 while purging with nitrogen. Mass parts were added, and the mixture was heated to 45 ° C. and dissolved. Next, the mixture was cooled to 38 to 40 ° C., and 44.4 parts by mass of flake caustic soda (purity: 99%, manufactured by Tosoh Corp.) (1.1 molar equivalents relative to 1 molar equivalent of the hydroxyl group of the phenol resin) was added over 60 minutes. Thereafter, further allyl chloride (purity 98.7% commercially available allyl chloride was separated by distillation. Gas chromatography confirmed that the allyl chloride polymer was less than 0.2 area%) 101.5 parts by mass (of phenol resin) 1.3 mole equivalents per 1 mole equivalent of hydroxyl group) was added dropwise over 60 minutes, and the reaction was carried out at 38 to 40 ° C. for 5 hours and then at 60 to 65 ° C. for 1 hour.
After completion of the reaction, water, dimethyl sulfoxide and the like were distilled off under reduced pressure by heating at 135 ° C. or lower using a rotary evaporator. And 740 mass parts of methyl isobutyl ketone was added, and water washing was repeated, and it confirmed that the water layer became neutral. Thereafter, the solvent was distilled off from the oil layer using a rotary evaporator under nitrogen bubbling under reduced pressure to obtain 240 parts by mass of AEP having the formula (I) where n = 2.4. The measurement result of the obtained AEP by high performance liquid chromatography (HPLC) corresponds to FIG. 2 described above.

[Example 1]
To a flask equipped with a stirrer, a reflux condenser, and a stirrer, while purging with nitrogen, the toluene solution containing the synthesized AEP (concentration of AEP: 15% by mass) was charged, and tungstic acid per mol of AEP. 0.16 mol part of sodium tungstate dihydrate as a compound, 0.08 mol part of trioctylmethylammonium acetate (TOMAA) as a quaternary ammonium salt, 0.1 mol of phosphoric acid as a phosphate compound 2.7 parts by mass (85% phosphoric acid aqueous solution) and Amberlyst 35 WET (purchased from Organo) as a cation exchange resin per 100 parts by mass of AEP were added, and the mixture was heated to 90 ° C. After the temperature rise, with stirring, a 30% aqueous hydrogen peroxide solution was added over 20 minutes so that hydrogen peroxide was 3 molar equivalents relative to 1 molar equivalent of allyl groups in AEP. After completion of the addition, the mixture was stirred at 90 ° C. for 2 hours.
Subsequently, it was quenched with an aqueous sodium thiosulfate solution, and the aqueous phase was separated to obtain a solution containing an epoxy resin. ^As confirmed by ¹ H-NMR, the conversion was 94%, the selectivity was 98%, and the production rate was 92%.

[Example 2]
An epoxy resin was obtained in the same manner as in Example 1 except that the reaction time after the addition of hydrogen peroxide solution was 2.5 hours. The conversion was 96%, the selectivity was 96%, and the production rate was 92%.

[Example 3]
An epoxy resin was obtained in the same manner as in Example 1 except that the amount of Amberlyst 35 WET as the cation exchange resin was changed to 3.0 parts by mass per 100 parts by mass of AEP. The conversion was 97%, the selectivity was 86%, and the production rate was 83%.

[Example 4]
An epoxy resin was obtained in the same manner as in Example 1 except that the amount of Amberlyst 35 WET as the cation exchange resin was 3.5 parts by mass per 100 parts by mass of AEP. The conversion was 100%, the selectivity was 71%, and the production rate was 71%.

[Comparative Example 1]
To a flask equipped with a stirrer, a reflux condenser, and a stirrer, while purging with nitrogen, the toluene solution containing the synthesized AEP (AEP concentration: 10% by mass) was charged, and tungstic acid per mole of AEP. 0.02 mol part of sodium tungstate dihydrate as a compound, 0.01 mol part of trioctylmethylammonium chloride (TOMACl) as a quaternary ammonium salt, and 0.02 mol of phosphoric acid as a phosphate compound. 26 mol part (85% phosphoric acid aqueous solution) was added, and the temperature of the mixture was increased to 90 ° C. Cation exchange resin was not used. After the temperature rise, with stirring, a 30% aqueous hydrogen peroxide solution was added over 30 minutes in such an amount that hydrogen peroxide was 1 molar equivalent to 1 molar equivalent of allyl group in AEP. After completion of the addition, the mixture was stirred at 90 ° C. for 3 hours.
Subsequently, it was quenched with an aqueous sodium thiosulfate solution, and the aqueous phase was separated to obtain a solution containing an epoxy resin. ^When confirmed by ¹ H-NMR, the conversion was 40%, the selectivity was 72%, and the production rate was 29%.

[Comparative Example 2]
An epoxy resin was obtained in the same manner as in Comparative Example 1 except that the concentration of the AEP toluene solution was changed to 5% by mass (the amount of AEP itself charged was the same as in Comparative Example 1). The conversion was 29%, the selectivity was 66%, and the production rate was 19%.

[Comparative Example 3]
An epoxy resin was obtained in the same manner as in Comparative Example 1, except that the concentration of the toluene solution of AEP was 15% by mass (the amount of AEP itself input was the same as in Comparative Example 1). The conversion was 55%, the selectivity was 60%, and the production rate was 32%.

[Comparative Example 4]
An epoxy resin was obtained in the same manner as in Comparative Example 1, except that the concentration of the toluene solution of AEP was 20% by mass (the amount of AEP itself input was the same as in Comparative Example 1). The conversion was 50%, the selectivity was 54%, and the production rate was 27%.

[Comparative Example 5]
An epoxy resin was obtained in the same manner as in Comparative Example 1 except that the AEP was changed to a 1,2-dichlorobenzene solution (AEP concentration: 10% by mass, the amount of AEP itself charged was the same as in Comparative Example 1). The conversion was 45%, the selectivity was 32%, and the production rate was 15%.

[Comparative Example 6]
An epoxy resin was obtained in the same manner as in Comparative Example 1 except that the AEP was changed to a trichloromethane solution (AEP concentration: 10% by mass, and the input amount of AEP itself was the same as in Comparative Example 1), and the reaction temperature was 60 ° C. It was. The conversion was 24%, the selectivity was 75%, and the production rate was 18%.

[Comparative Example 7]
An epoxy resin was obtained in the same manner as in Comparative Example 1 except that the AEP was changed to a dichloroethane solution (AEP concentration: 10% by mass, the input amount of AEP itself was the same as in Comparative Example 1), and the reaction temperature was 60 ° C. . The conversion was 13%, the selectivity was 72%, and the production rate was 9%.

[Comparative Example 8]
An epoxy resin was obtained in the same manner as in Comparative Example 1 except that the AEP was changed to a dichloroethane solution (AEP concentration: 10% by mass, the amount of AEP itself charged was the same as in Comparative Example 1). The conversion was 25%, the selectivity was 69%, and the production rate was 17%.

[Comparative Example 9]
AEP was changed to a dichloroethane solution (AEP concentration: 10% by mass, the input amount of AEP itself was the same as in Comparative Example 1), the reaction temperature was set to 80 ° C., and the reaction time after the addition of hydrogen peroxide solution was set to 24 hours. Obtained an epoxy resin in the same manner as in Comparative Example 1. The conversion was 38%, the selectivity was 46%, and the production rate was 17%.

[Comparative Example 10]
An epoxy resin was obtained in the same manner as in Comparative Example 1 except that the AEP was changed to an ethyl acetate solution (AEP concentration: 10% by mass, the amount of AEP itself charged was the same as in Comparative Example 1), and the reaction temperature was 60 ° C. It was. The conversion was 14%, the selectivity was 27%, and the production rate was 4%.

The results are summarized in Tables 1 and 2 below.

As can be seen from the results in Table 1, Examples 1 to 4 had an epoxy group production rate of 70% or more, which was higher than that of Comparative Examples 1 to 10. In Examples 1 to 3, the production rate was 80% or more, which was a particularly high value. Comparative Examples 1 to 10 did not use a cation exchange resin, and the conversion and production rate were particularly low.
In addition, the epoxy resins obtained in Examples 1 to 3 have an L / M value exceeding 0 and 0.1 or less, containing both an epoxy group and an allyl group, and the epoxy group is compared to the allyl group. As a result, it is found that it is more than 10 times more useful as an epoxy resin. On the other hand, the epoxy resins obtained in Comparative Examples 1 to 10 have an L / M value significantly exceeding 0.1 and contain both an epoxy group and an allyl group, but the ratio of the epoxy group is not sufficient. I understand that.

Claims

In the presence of a tungstic acid compound, a quaternary ammonium salt, a cation exchange resin, and a phosphoric acid compound, the following formula (I):

(In the formula, n represents an average value of the number of repetitions of 1 to 20)
A process for producing an epoxy resin, comprising a step of reacting a compound represented by formula (II) with hydrogen peroxide.
The method for producing an epoxy resin according to claim 1, wherein the amount of the cation exchange resin used is 1 to 10 parts by mass per 100 parts by mass of the compound represented by the formula (I).
The epoxy according to claim 1 or 2, wherein the step of reacting the compound represented by the formula (I) with hydrogen peroxide is performed in a three-phase system of an organic phase, an aqueous phase, and a solid phase. Manufacturing method of resin.
Formula (II) below:

And the following formula (III):

Containing repeating units of
An epoxy resin in which the average value L of the number of allyl groups in one molecule and the average value M of the number of epoxy groups in one molecule satisfy a relationship of 0 <L / M ≦ 0.1.
A curable resin composition comprising the epoxy resin according to claim 4 and a curing agent.
A cured product obtained by curing the curable resin composition according to claim 5.