JP5905709B2 - Epoxy resin production method and epoxy resin obtained using the production method - Google Patents

Description

  The present invention relates to a method for producing an epoxy resin, an epoxy resin obtained by using the production method, and an epoxy resin composition containing the epoxy resin.

  A cured product of the epoxy resin composition is excellent in heat resistance, adhesiveness, water resistance, mechanical strength, electrical characteristics, and the like, and thus is used for various applications. In recent years, epoxy resins containing less halogen-containing impurities are desired as epoxy resins used in the electric / electronic field due to problems of corrosion and electrical reliability. Therefore, development of a technique for further reducing impurities containing halogen atoms is desired.

  Patent Document 1 describes a technique for reducing hydrolyzable chlorine in a resin using an alcohol solution of a metal alkoxide.

  Patent Document 2 discloses a resin in which total chlorine is reduced using a powdered alkali metal hydroxide, and Patent Document 3 discloses a total chlorine in a resin using a sulfoxide compound as a solvent during dechlorination reaction. An example in which is reduced is described.

Japanese Patent Publication No. 4-50923 Japanese Examined Patent Publication No. 6-62596 Japanese Patent Publication No. 3-12088

  However, in the method disclosed in Patent Document 1, hydrolyzable chlorine in the resin can be reduced, but the effect of reducing organic bond chlorine in the resin is small. Further, Patent Documents 2 and 3 describe methods for reducing organic bond chlorine in the resin, but in these methods, a large amount of gel impurities may be generated. Furthermore, when the sulfoxide compound described in Patent Document 3 is used, the sulfur element cannot be sufficiently removed, and if the epoxy resin obtained by purification is modified with another resin, it will gel at the time of modification. There is.

  The present invention has been made in view of the above points, and a method for producing an epoxy resin capable of efficiently removing all chlorine containing organic bond chlorine while suppressing the formation of a gel component, and an epoxy resin obtained from the method. And an epoxy resin composition containing the epoxy resin.

  As a result of intensive studies, the present inventors have found that the above problems can be solved by a specific method, and have completed the present invention.

  That is, the present invention is as follows.

[1]
(1) a step of dissolving a crude epoxy resin containing a chlorine content in a solvent containing a solvent having a keto group to obtain a solution; and (2) the solution obtained in the step (1) is replaced with a metal alkoxide compound. A process of obtaining an epoxy resin having a reduced chlorine content by treatment,
A method for producing an epoxy resin, comprising:

[2]
The method for producing an epoxy resin according to [1], wherein the treatment temperature in the step (2) is 40 ° C. or lower.

[3]
The method for producing an epoxy resin according to [1] or [2], wherein the treatment time in the step (2) is 290 minutes or less.

[4]
The method for producing an epoxy resin according to any one of [1] to [3], wherein the metal alkoxide compound is solid.

[5]
The metal alkoxide compound includes one or more compounds selected from the group consisting of sodium methoxide, sodium ethoxide, sodium propoxide, sodium butoxide, potassium methoxide, potassium ethoxide, potassium propoxide and potassium butoxide. The manufacturing method of the epoxy resin in any one of [1]-[4].

[6]
The epoxy resin according to any one of [1] to [5], wherein the solvent having a keto group includes one or more solvents selected from the group consisting of acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, and cyclohexanone. Production method.

[7]
An epoxy resin obtained by the method for producing an epoxy resin according to any one of [1] to [6].

[8]
A modified epoxy resin obtained by reacting the epoxy resin according to [7] with a bifunctional or higher phenol compound and / or an isocyanate compound.

[9]
An epoxy resin composition comprising the epoxy resin according to [7] or the modified epoxy resin according to [8].

  According to the method for producing an epoxy resin of the present invention, an epoxy resin from which all chlorine has been efficiently removed and an epoxy resin composition containing the epoxy resin can be obtained while suppressing the generation of gel components.

  Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as “the present embodiment”) will be described in detail. The following embodiments are examples for explaining the present invention, and are not intended to limit the present invention to the following contents. The present invention can be implemented with appropriate modifications within the scope of the gist.

<Method for producing epoxy resin>
The method for producing an epoxy resin of the present embodiment includes (1) a step of dissolving a crude epoxy resin containing a chlorine content in a solvent containing a solvent having a keto group, and (2) in the step (1). The step of treating the obtained solution with a metal alkoxide compound to obtain an epoxy resin with reduced chlorine content is included. By performing a purification step (purification method) including these steps (1) and (2), an epoxy resin having a sufficiently reduced chlorine content can be obtained from the crude epoxy resin while suppressing the formation of gel components.

<Rough epoxy resin>
The crude epoxy resin used in the present embodiment can be obtained by a known method. For example, a compound having an average of two or more active hydrogens per molecule and an epichlorohydrin compound are mixed with an alkali metal hydroxide. It can be obtained by a condensation reaction in the presence. Examples of the compound having active hydrogen as a raw material include various compounds such as bisphenol A, bisphenol F, bisphenol AD, biphenol, tetramethylbiphenol, hydroquinone, methylhydroquinone, dibutylhydroquinone, resorcin, methylresorcin, dihydroxydiphenyl ether, and dihydroxynaphthalene. Phenols such as: phenol novolac resin, cresol phenol novolac resin, bisphenol A novolac resin, phenol aralkyl resin, terpene phenol resin, dicyclopentadiene phenol resin, biphenyl phenol resin, etc .; various phenols and hydroxy Various aldehydes such as benzaldehyde, crotonaldehyde, and glyoxal And various phenolic compounds such as polyhydric phenol resins obtained by the condensation reaction of; various amino compounds such as diaminodiphenylmethane, aminophenol and xylenediamine; and various carboxylic acids such as methylhexahydroxyphthalic acid and dimer acid. It is done.

  The crude epoxy resin obtained by such a production method contains chlorine as an impurity. Examples of the chlorine content include inorganic chlorine and organic bond chlorine. Furthermore, organic bondable chlorine includes hydrolyzable chlorine that can be easily dechlorinated with alkali metal hydroxides, and hardly hydrolyzable chlorine that is difficult to dechlorinate with alkali metal hydroxides. In the present embodiment, these inorganic chlorine and organic bond chlorine are combined and referred to as “total chlorine”.

  In the production method of the present embodiment, the solvent having a keto group used in step (1) is not particularly limited as long as it has a keto group in the structure. For example, acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl Examples include chain ketones such as ketones; and cyclic ketones such as cyclopentanone, cyclohexanone, and cycloheptanone. Of these, one or more types may be contained, and a combination with other solvents such as toluene is also possible. Among them, the solvent having a keto group preferably contains one or more solvents selected from the group consisting of acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone and cyclohexanone. By using these solvents, not only can the chlorine content in the crude epoxy resin be efficiently removed, but also an increase in the viscosity of the solution in which the crude epoxy resin is dissolved in the above solvent can be suppressed, and gel components can be generated. Can be suppressed. In particular, when chain ketones are used, the solubility of the metal alkoxide compound to be used in the solution is improved, so that the chlorine-containing impurities in the crude epoxy resin can be efficiently reacted with the metal alkoxide compound. . Among these, acetone and methyl ethyl ketone are preferable and acetone is more preferable from the viewpoint of high solubility of the metal alkoxide compound. When these solvents are used, the affinity between the solvent and the epoxy resin is low, and the residual solvent after the distillation can be eliminated. Therefore, the modification using the phenol compound or the like described below is not affected by the solvent used. The reaction can be performed.

  The method for producing an epoxy resin of the present embodiment can provide an epoxy resin having a reduced chlorine content (hereinafter also referred to as “low chlorination”) by including the purification step.

  The reason why the chlorination can be reduced by including the purification step is not clear, but the present inventors presume as follows.

  As described above, the crude epoxy resin contains, for example, both inorganic chlorine and organic bond chlorine as chlorine. Hydrolyzable chlorine in organic bond chlorine is separated as inorganic chlorine by metal ions in metal alkoxide, and hardly hydrolyzable chlorine is separated as inorganic chlorine by bimolecular elimination reaction with alkoxy ions. It is estimated that the chlorine content in the crude epoxy resin can be reduced by washing and removing with purified water. If a solvent having a keto group is used as the solvent at this time, the polarized oxygen of the keto group acts on the carbon atom to which the hardly hydrolyzable chlorine is bonded, so that the chlorine atom in the crude epoxy resin is more likely to come off. Estimated.

  In the method for producing an epoxy resin of the present embodiment, the concentration of the crude epoxy resin used in the step (1) is 10 when the total of the crude epoxy resin used in the step (1) and the solvent having a keto group is 100% by mass. It is preferably within the range of less than -100% by mass, and more preferably within the range of less than 15-100% by mass from the viewpoint of ease of production.

  As processing temperature in a process (2), it is preferable that it is 40 degrees C or less, It is more preferable that it is 35 degrees C or less, It is further more preferable that it is 30 degrees C or less. As a minimum of processing temperature in a process (2), it is preferred that it is 0 ° C or more. The reaction between the chlorine-containing impurities in the crude epoxy resin and the metal alkoxide compound can be suppressed at 40 ° C. or lower, thereby suppressing the high molecular weight reaction and increasing the epoxy equivalent and viscosity of the resulting epoxy resin. Can be suppressed.

  As processing time in a process (2), it is preferable that it is 290 minutes or less. As a minimum of processing time in a process (2), it is preferred that it is 5 minutes or more. Since the high molecular weight reaction is a sequential reaction, an increase in the high molecular weight component can be prevented when the treatment time in step (2) is 290 minutes or less. The treatment time in step (2) is more preferably 90 minutes or less.

  Examples of the metal alkoxide compound used in the step (2) include lithium methoxide, sodium methoxide, potassium methoxide, lithium ethoxide, sodium ethoxide, potassium ethoxide, lithium propoxide, sodium propoxide, potassium propoxide. , Lithium butoxide, sodium butoxide, potassium butoxide and isomers thereof, and one or more of these can be used at the time of use. Since these metal alkoxide compounds can react with impurities containing chlorine in the crude epoxy resin at a low temperature, the reaction between epoxy resins can be suppressed by using these metal alkoxide compounds. Therefore, a high molecular weight reaction is unlikely to occur, and generation of a gelling component can be suppressed. The metal alkoxide compound includes at least one compound selected from the group consisting of sodium methoxide, sodium ethoxide, sodium propoxide, sodium butoxide, potassium methoxide, potassium ethoxide, potassium propoxide and potassium butoxide. preferable. Among these, sodium methoxide, sodium butoxide, and potassium butoxide are preferable, and potassium butoxide is more preferable because it easily generates an alkoxy ion necessary for eliminating hardly hydrolyzable chlorine in the reaction solution.

  The addition amount of the metal alkoxide compound used in the present embodiment is not limited as long as the total chlorine amount in the crude epoxy resin is sufficiently reduced and the epoxy resin does not gel, but the total chlorine contained in the epoxy resin is not limited. It is preferably 1 to 20 molar equivalents relative to the amount, more preferably 2.5 to 20 molar equivalents from the point of reaction rate, and the point of facilitating oil-water separation when washing impurity ions To 2.5 to 15 molar equivalents.

  The metal alkoxide compound is preferably a solid. When the metal alkoxide compound is liquid, dechlorination reaction occurs even if it is dissolved in ketones, but the reaction time is long because the metal alkoxide concentration decreases at a stretch. When the metal alkoxide compound is added as a solid, the metal alkoxide compound dissolves in the solvent little by little, so that a high-concentration metal alkoxide solution is locally formed, so that the dechlorination reaction easily proceeds. In view of uniformly dispersing the metal alkoxide compound in the reaction system, the metal alkoxide compound is more preferably granular or powdery.

  In addition, the manufacturing method of the present embodiment may further include (3) a step of separating the separated chlorine content and the epoxy resin.

  The method for separating the chlorine component and the epoxy resin in the step (3) is not particularly limited as long as the epoxy resin does not gel and the chlorine component separated from the epoxy resin in the step (2) is removed. Examples include a method in which purified water is added and chlorine ions are dissolved in an aqueous solution and separated, a method using an ion exchange resin, a method of separating by molecular distillation of an epoxy resin, and the like. In the case of a method in which purified water is added and chlorine ions are dissolved in an aqueous solution and separated, neutralization is performed in advance by adding an acid such as phosphoric acid, carbonic acid, or nitric acid, and then the organic layer is washed with purified water. Separation between the water layer and the aqueous layer is good, and when the solvent containing a keto group is removed by distillation, a high molecular weight reaction is not caused.

<Epoxy resin>
The epoxy resin of this embodiment is obtained by the manufacturing method of the above-mentioned epoxy resin.

  Since the epoxy resin of the present embodiment obtained by the above-described production method is an epoxy resin obtained through a reaction in which a high molecular weight reaction is suppressed, an increase in epoxy equivalent is suppressed compared to before the reaction. Yes. Moreover, the epoxy resin of this embodiment can suppress the production of α-glycol because hydrolysis caused when an alkali metal hydroxide is used hardly occurs. As a result, the physical properties of the cured product obtained by the reaction rate and curing of the epoxy resin of this embodiment do not change.

<Modified epoxy resin>
The modified epoxy resin of this embodiment can be obtained by reacting (also referred to as “modified”) the above-described epoxy resin with a bifunctional or higher functional phenol compound and / or an isocyanate compound. Since the epoxy resin obtained by the above-mentioned production method usually does not contain a sulfur component, no high molecular weight reaction occurs during modification.

  The bifunctional or higher phenol compound is not particularly limited as long as it has two or more phenolic hydroxyl groups. For example, bisphenol A, bisphenol F, bisphenol AD, bisphenol S, tetramethylbisphenol A, tetramethylbisphenol F, tetramethylbisphenol AD, tetramethylbisphenol S, tetrabromobisphenol A, biphenol, dihydroxybenzene, dihydroxybenzene substituent adduct, 1,1,1-tris (4-hydroxyphenyl) methane, 1,1,1- (4-hydroxy Phenyl) ethane, 4,4- [1- [4- [1- (4-hydroxyphenyl) -1-methylethyl] phenyl] ethylidene] bisphenol, phenol novolak, cresol novolak, bisphenol A Novolac, naphthol novolac, phenol aralkyl, and the like. These may be used in combination of one or two or more kinds.

An isocyanate compound is a compound having two or more isocyanate groups in the molecule. For example, methane diisocyanate, butane-1,1-diisocyanate, ethane-1,2-diisocyanate, butane-1,2-diisocyanate, trans Vinylene diisocyanate, propane-1,3-diisocyanate, butane-1,4-diisocyanate, 2-butene-1,4-diisocyanate, 2-methylbutene-1,4-diisocyanate, 2-methylbutane-1,4-diisocyanate, pentane -1,5-diisocyanate, 2,2-dimethylpentane-1,5-diisocyanate, hexane-1,6-diisocyanate, heptane-1,7-diisocyanate, octane-1,8-diisocyanate, nonane-1,9- Diiso Decane-1,10-diisocyanate, dimethylsilane diisocyanate, diphenylsilane diisocyanate, ω, ω′-1,3-dimethylbenzene diisocyanate, ω, ω′-1,4-dimethylbenzene diisocyanate, ω, ω′-1 , 3-dimethylcyclohexane diisocyanate, ω, ω′-1,4-dimethylcyclohexane diisocyanate, ω, ω′-1,4-dimethylnaphthalene diisocyanate, ω, ω′-1,5-dimethylnaphthalene diisocyanate, cyclohexane-1, 3-diisocyanate, cyclohexane-1,4-diisocyanate, dicyclohexylmethane-4,4′-diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 1-methylbenzene-2,4-diisocyanate 1-methylbenzene-2,5-diisocyanate, 1-methylbenzene-2,6-diisocyanate, 1-methylbenzene-3,5-diisocyanate, diphenyl ether-4,4′-diisocyanate, diphenyl ether-2,4 ′ -Diisocyanate, naphthalene-1,4-diisocyanate, naphthalene-1,5-diisocyanate, biphenyl-4,4'-diisocyanate, 3,3'-dimethylbiphenyl-4,4'-diisocyanate, 2,3'-dimethoxybis Phenyl-4,4′-diisocyanate, diphenylmethane-4,4′-diisocyanate, 3,3′-dimethoxydiphenylmethane-4,4′-diisocyanate, 4,4′-dimethoxydiphenylmethane-3,3′-diisocyanate, diphenylsal Huite , 4'-diisocyanate, bifunctional isocyanate compounds such as diphenyl sulfone-4,4'-diisocyanate;
Polyfunctional isocyanate compounds such as polymethylene polyphenyl isocyanate, triphenylmethane triisocyanate, tris (4-phenylisocyanate thiophosphate) -3,3 ′, 4,4′-diphenylmethane tetraisocyanate;
Examples include, but are not limited to, multimers such as dimers and trimers of the isocyanate compounds, blocked isocyanates masked with alcohol and phenol, and bisurethane compounds. These isocyanate compounds may be used alone or in combination of two or more.

  Among the above isocyanate compounds, a bifunctional or trifunctional isocyanate compound is preferable, and a bifunctional isocyanate compound is more preferable. More preferred are bifunctional isocyanate compounds having isophorone type, benzene type, toluene type, diphenylmethane type, naphthalene type, polymethylene polyphenylene polyphenyl type and hexamethylene type.

<Epoxy resin composition>
The epoxy resin composition of this embodiment contains the above-mentioned epoxy resin or modified epoxy resin.

  The epoxy resin composition of the present embodiment can be obtained by mixing the above-described epoxy resin or modified epoxy resin with another epoxy resin or a curing agent depending on applications. Since the epoxy resin composition of the present embodiment has a small amount of chlorine in the contained epoxy resin or modified epoxy resin, the amount of chlorine in the entire epoxy resin composition can be kept low. As a result, when the epoxy resin composition of the present embodiment is used for an electric circuit board, the corrosiveness of the metal part, particularly copper or silver, is improved.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples.

  In this example, the measurement method of each physical property was as follows.

(1) Epoxy equivalent Determined according to JIS K7236. That is, the epoxy resin was dissolved in a solution of propyl alcohol and benzyl alcohol, potassium iodide was added, and titration was performed with 1N hydrochloric acid.

(2) Total chlorine content Determined according to JIS K7246. That is, an epoxy resin was dissolved in diethylene glycol monobutyl ether, a 1N potassium hydroxide-propylene glycol solution was added, and the mixture was boiled for 20 minutes, and then potentiometric titration was performed with silver nitrate.

(3) Hydrolyzable chlorine content It calculated | required according to JISK7243-2. That is, the epoxy resin was dissolved in a toluene solution, 0.1 N potassium hydroxide-methanol aqueous solution was added and the mixture was boiled for 15 minutes, and potentiometric titration was performed with silver nitrate.

(4) α-glycol amount Determined according to JIS K7146. That is, an epoxy resin was dissolved in chloroform, reacted with a periodic acid solution, sulfuric acid and potassium iodide were added, and titration was performed with sodium thiosulfate.

(5) Number average molecular weight Gel permeation chromatography (GPC) analysis using shodex A-804, A-803, A-802, A802 manufactured by Showa Denko KK as a column and elution time of polystyrene with known molecular weight The number average molecular weight was determined by comparison. A component having a number average molecular weight of 3000 or more was defined as a region having a high molecular weight component.

[Example 1]
Bisphenol A type epoxy (AER260 manufactured by Asahi Kasei Epoxy Co., Ltd., epoxy equivalent 188 (g / eq), total chlorine amount 1566 ppm, hydrolyzable chlorine amount 517 ppm, α-glycol amount 18 (meq / kg), hereinafter “BisA- Also referred to as “Ep”.) 50 parts by mass was dissolved in 100 parts by mass of dehydrated acetone at room temperature of 25 ° C. to obtain a solution. Thereafter, 0.10 parts by mass of sodium methoxide in powder form was added to the resulting solution and reacted at 40 ° C. for 90 minutes. Thereafter, 20 parts by mass of water was added to the solution to stop the reaction, and then neutralized by adding an alkali equivalent of phosphoric acid, and acetone was recovered under reduced pressure. Thereafter, 100 parts by mass of toluene was added to the solution, and further washed with water three times to separate the oil layer and the aqueous layer. After the completion of washing with water three times, toluene was recovered from the oil layer under reduced pressure to obtain epoxy resin A. The obtained epoxy resin A had an epoxy equivalent of 194 (g / eq), a total chlorine amount of 145 ppm, a hydrolyzable chlorine amount of 77 ppm, and an α-glycol amount of 25 (meq / kg). Analysis of the chart obtained from GPC revealed that no high molecular weight component was produced in epoxy resin A.

[Example 2]
Epoxy resin B was obtained in the same manner as in Example 1 except that dehydrated acetone was changed to dehydrated methyl ethyl ketone (MEK). The obtained epoxy resin B had an epoxy equivalent of 196 (g / eq), a total chlorine content of 172 ppm, a hydrolyzable chlorine content of 100 ppm, and an α-glycol content of 18 (meq / kg). Analysis of the chart obtained from GPC revealed that no high molecular weight component was produced in epoxy resin B.

[Example 3]
Epoxy resin C was obtained in the same manner as in Example 1 except that dehydrated acetone was changed to cyclohexanone. The obtained epoxy resin C had an epoxy equivalent of 194 (g / eq), a total chlorine amount of 185 ppm, a hydrolyzable chlorine amount of 92 ppm, and an α-glycol amount of 21 (meq / kg). Analysis of the chart obtained from GPC revealed that no high molecular weight component was produced in epoxy resin C.

[Example 4]
Epoxy resin D was obtained in the same manner as in Example 1 except that 0.10 parts by mass of sodium methoxide was changed to 0.36 parts by mass of potassium t-butoxide. The obtained epoxy resin D had an epoxy equivalent of 187 (g / eq), a total chlorine amount of 80 ppm, a hydrolyzable chlorine amount of 40 ppm, and an α-glycol amount of 19 (meq / kg). When the chart calculated | required from GPC was analyzed, in the epoxy resin D, the high molecular weight component was not producing | generating.

[Example 5]
In Example 4, potassium t-butoxide was added once as a 5 mass% solution using dehydrated acetone, and the others were carried out in the same manner as in Example 4 to obtain an epoxy resin E. The obtained epoxy resin E has an epoxy equivalent of 187 (g / eq), a total chlorine amount of 85 ppm, a hydrolyzable chlorine amount of 40 ppm, an α-glycol amount of 20 (meq / kg), and a chart obtained from GPC analysis. In Epoxy Resin E, no high molecular weight component was produced, and a resin almost equivalent to Example 4 was obtained.

[Example 6]
Epoxy resin F was obtained in the same manner as in Example 4 except that the reaction conditions were changed to 50 ° C. for 30 minutes. The obtained epoxy resin F had an epoxy equivalent of 197 (g / eq), a total chlorine amount of 55 ppm, a hydrolyzable chlorine amount of 8 ppm, and an α-glycol amount of 28 (meq / kg). When the chart calculated | required from GPC was analyzed, in the epoxy resin F, 2 mass% of high molecular weight components were produced | generated.

[Example 7]
Epoxy resin G was obtained in the same manner as in Example 1 except that the reaction conditions were changed to 300 ° C. for 300 minutes. The obtained epoxy resin G had an epoxy equivalent of 199 (g / eq), a total chlorine amount of 45 ppm, a hydrolyzable chlorine amount of 1 ppm, and an α-glycol amount of 40 (meq / kg). When the chart calculated | required from GPC was analyzed, in the epoxy resin G, the high molecular weight component was producing | generating 5 mass%.

[Example 8]
The reaction was carried out in the same manner as in Example 1 except that the reaction conditions were changed to 50 ° C. for 300 minutes. As a result, the resin became high molecular weight during the reaction, and the oil-water separation was not successful and could not be recovered. Therefore, 50 parts by mass of ethyl acetate was added, the separated organic layer was fractionated, and the organic solvent was removed from the obtained organic layer under reduced pressure to obtain an epoxy resin H. The obtained epoxy resin H had an epoxy equivalent of 526 (g / eq), a total chlorine content of 23 (ppm), a hydrolyzable chlorine content of 10 (ppm), and an α-glycol content of 31 (meq / kg). When the chart obtained from GPC was analyzed, in the epoxy resin H, 42 mass% of high molecular weight components were produced.

[Example 9]
Bisphenol A type epoxy resin is bisphenol F type epoxy resin (manufactured by DIC Corporation, Epiclone 830, epoxy equivalent 172 (g / eq), total chlorine amount 3015 ppm, hydrolyzable chlorine amount 1416 ppm, α-glycol amount 25 (meq / kg) ) Hereinafter, it is also referred to as “BisF-Ep”.) Except for changing the amount of acetone to 200 parts by mass, the same procedure as in Example 1 was performed to obtain an epoxy resin I. The obtained epoxy resin I had an epoxy equivalent of 175 (g / eq), a total chlorine amount of 187 ppm, hydrolyzable chlorine of 82 ppm, and an α-glycol amount of 25 (meq / kg). Analysis of the chart obtained from GPC revealed that no high molecular weight component was produced in epoxy resin I.

[Example 10]
Bisphenol A type epoxy resin is converted to tetraglycidyl diaminodiphenylmethane resin (JER Corporation, Epicoat 604, epoxy equivalent 110 (g / eq), total chlorine amount 6008 (ppm), hydrolyzable chlorine amount 287 (ppm), α-glycol The amount was changed to 35 (meq / kg), hereinafter also referred to as “TGDDM”), the amount of sodium methoxide to be added was changed to 0.60 parts by mass, and the amount of acetone was changed to 200 parts by mass. In the same manner as in Example 1, an epoxy resin J was obtained. The obtained epoxy resin J had an epoxy equivalent of 120 (g / eq), a total chlorine content of 226 (ppm), a hydrolyzable chlorine of 46 (ppm), and an α-glycol content of 45 (meq / kg). Analysis of the chart obtained from GPC revealed that no high molecular weight component was produced in epoxy resin J.

[Example 11]
Bisphenol A type epoxy resin is triglycidyl aminophenol resin (JER Corporation, Epicoat 630, epoxy equivalent 98 (g / eq), total chlorine content 6502 (ppm), hydrolyzable chlorine content 906 (ppm), α-glycol Amount 35 (meq / kg), hereinafter also referred to as “TGAP”), except that the amount of potassium t-butoxide to be added is changed to 0.60 parts by mass and the amount of acetone is changed to 200 parts by mass. Epoxy resin K was obtained in the same manner as in Example 4. The obtained epoxy resin K had an epoxy equivalent of 115 (g / eq), a total chlorine amount of 154 (ppm), hydrolyzable chlorine 66 (ppm), and an α-glycol amount of 42 (meq / kg). When the chart obtained from GPC was analyzed, no high molecular weight component was produced in epoxy resin K.

[Comparative Example 1]
50 parts by mass of bisphenol A type epoxy (AER260 manufactured by Asahi Kasei Epoxy Co., Ltd., epoxy equivalent 193 (g / eq), total chlorine content 1566 ppm, hydrolyzable chlorine content 517 ppm, α-glycol content 18 (meq / kg)) The reaction was carried out according to Example 1 described in JP-B-4-50923. That is, a solution was obtained by dissolving 50 parts by mass of bisphenol A type epoxy in 75 parts by mass of toluene so that the concentration of bisphenol A type epoxy was 40% by mass. The solution was refluxed at 110 ° C. so that the water content in the solution was less than 0.05% by mass. Next, the solution was cooled to 105 ° C., and 2.6 parts by mass of a 14% by mass t-butanol solution of potassium t-butoxide was added and stirred for 30 minutes. Thereafter, the solution was cooled to 45 ° C., 0.63 parts by mass of water was added, and 1.8 parts by mass of dry ice was added over 15 minutes while maintaining the temperature at 45 ° C. Then, it wash | cleaned 3 times with purified water, and isolate | separated the oil layer and the water layer. After completion of washing with purified water three times, toluene was recovered from the oil layer under reduced pressure to obtain an epoxy resin L. The obtained epoxy resin L had an epoxy equivalent of 242 (g / eq), a total chlorine amount of 825 (ppm), a hydrolyzable chlorine amount of 34 (ppm), and an α-glycol amount of 68 (meq / kg). When the chart calculated | required from GPC was analyzed, in the epoxy resin L, 12 mass% of high molecular weight components were produced | generated.

[Comparative Example 2]
An epoxy resin M was obtained in the same manner as in Example 1 except that granular potassium hydroxide was used instead of sodium methoxide. The obtained epoxy resin M has an epoxy equivalent of 190 (g / eq), a total chlorine content of 1134 (ppm), a hydrolyzable chlorine content of 310 (ppm), and an α-glycol content of 40 (meq / kg). The progress of the reaction was small. Analysis of the chart obtained from GPC revealed that no high molecular weight component was produced in the epoxy resin M.

[Comparative Example 3]
Except that the solvent was changed from acetone to toluene, the same procedure as in Example 1 was carried out. As a result, the oil / water separation at the time of washing with water was poor, and it took a long time to obtain an epoxy resin N. The obtained epoxy resin N had an epoxy equivalent of 189 (g / eq), a total chlorine content of 972 (ppm), a hydrolyzable chlorine content of 181 (ppm), and an α-glycol content of 30 (meq / kg). When the chart obtained from GPC was analyzed, the epoxy resin N did not contain a component having a molecular weight of 3000 or more.

[Comparative Example 4]
Commercially available bisphenol A type epoxy (AER260 manufactured by Asahi Kasei Epoxy Corporation, epoxy equivalent 188 (g / eq), total chlorine content 1566 ppm, hydrolyzable chlorine 517 ppm content, α-glycol content 18 (meq / kg)) The reaction was carried out in the same manner as in Example 15 described in JP-B-3-12088. That is, a solution was obtained by dissolving bisphenol A type epoxy in 100 parts by mass and 200 parts by mass of dimethyl sulfoxide. After heating the obtained solution to 50 degreeC, 0.76 mass part of potassium t-butoxide was thrown in and it was made to react for 30 minutes, and the epoxy resin O was obtained. The obtained epoxy resin O had an epoxy equivalent of 201 (g / eq), a total chlorine amount of 351 (ppm), a hydrolyzable chlorine amount of 65 (ppm), and an α-glycol amount of 61 (meq / kg). When the chart obtained from GPC was analyzed, in the epoxy resin O, a high molecular weight component was produced at 8% by mass.

Claims (12)

(1) a step of dissolving a crude epoxy resin containing a chlorine content in a solvent containing a solvent having a keto group to obtain a solution; and (2) the solution obtained in the step (1) in a solid state, or A step of obtaining an epoxy resin having a reduced chlorine content by introducing a metal alkoxide compound in a state dissolved in a solvent having a keto group ;
A method for producing an epoxy resin, comprising:   The manufacturing method of the epoxy resin of Claim 1 whose process temperature in the said process (2) is 40 degrees C or less.   The manufacturing method of the epoxy resin of Claim 1 or 2 whose processing time in the said process (2) is 290 minutes or less.   The manufacturing method of the epoxy resin of any one of Claims 1-3 whose said metal alkoxide compound is solid.   The metal alkoxide compound comprises one or more compounds selected from the group consisting of sodium methoxide, sodium ethoxide, sodium propoxide, sodium butoxide, potassium methoxide, potassium ethoxide, potassium propoxide and potassium butoxide. Item 5. The method for producing an epoxy resin according to any one of Items 1 to 4.   The epoxy resin according to any one of claims 1 to 5, wherein the solvent having a keto group contains one or more solvents selected from the group consisting of acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone and cyclohexanone. Production method. (1) a step of obtaining a solution by dissolving a crude epoxy resin containing a chlorine content in a solvent containing a solvent having a keto group; and
(2) An epoxy resin in which the chlorine content is reduced by treating the solution obtained in the step (1) by adding a metal alkoxide compound in a solid state or in a state dissolved in a solvent having a keto group. Obtaining steps; and
A method for producing a modified epoxy resin , comprising a step of reacting the epoxy resin obtained in the step (2) with a bifunctional or higher functional phenol compound and / or an isocyanate compound.   The manufacturing method of the modified | denatured epoxy resin of Claim 7 whose process temperature in the said process (2) is 40 degrees C or less.   The method for producing a modified epoxy resin according to claim 7 or 8, wherein the treatment time in the step (2) is 290 minutes or less.   The method for producing a modified epoxy resin according to any one of claims 7 to 9, wherein the metal alkoxide compound is solid.   The metal alkoxide compound comprises one or more compounds selected from the group consisting of sodium methoxide, sodium ethoxide, sodium propoxide, sodium butoxide, potassium methoxide, potassium ethoxide, potassium propoxide and potassium butoxide. Item 11. A method for producing a modified epoxy resin according to any one of Items 7 to 10.   The modified epoxy resin according to any one of claims 7 to 11, wherein the solvent having a keto group includes one or more solvents selected from the group consisting of acetone, methyl ethyl ketone, diethyl ketone, methyl isobutyl ketone, and cyclohexanone. Manufacturing method.