KR0171932B1 - Preparation process of novolac epoxy resin - Google Patents

Abstract

The present invention relates to a method for producing a high-purity novolak-type epoxy resin from a novolak-type phenolic resin, more specifically, mainly used in the electric and battery industry, and contains almost no impurities such as unreacted raw materials and catalysts. The present invention relates to a method for producing a high-purity novolak-type epoxy resin from a high purity novolak-type phenolic resin which is not present.

That is, phenols and aldehydes are reacted under an acid catalyst to produce a novolak-type phenolic resin, wherein the phenols and aldehydes are present in water or 1 to 30 carbon atoms or ketones based on 100 parts by weight based on 100 parts by weight. After the addition of parts by weight, the reaction was carried out under an acid catalyst, and when the reaction was completed, 200 to 300 parts by weight of the hydrophobic organic solvent was added to 100 parts by weight of the resin to completely dissolve the novolak-type phenolic resin. After separating the lower layer of water to remove the lower layer of water and 30 to 100 parts by weight of ionized water or distilled water with respect to 100 parts by weight of the resin, the content of unreacted phenols is 20ppm or less, the amount of remaining catalyst is 0.2ppm or less, Water was washed so that the content of other unreacted substances was 1 ppm or less and the electrical conductivity was 5.0 ㎲ / cm or less, and after filtering the resin containing the solvent, the hydrophobic organic solvent was recovered. It is written producing a novolak type phenolic resin.

Description

[Name of invention]

Manufacturing method of high purity novolac type epoxy resin

Detailed description of the invention

The present invention relates to a method for producing a high-purity novolak-type epoxy resin from a novolak-type phenolic resin, and more specifically, mainly used in the electric and electronic industries, and contains almost no impurities such as unreacted raw materials and catalysts. The present invention relates to a method for producing a high purity novolak type epoxy resin from a high purity novolak type phenolic resin which is not present.

Novolak-type epoxy resins made from novolac-type phenolic resins can be obtained in the form of cured products having excellent crosslinking density, curing properties such as chemical resistance, moisture resistance, and heat resistance when cured. It is widely used as a raw material for ash.

However, when using an epoxy resin with a high content of hydrolyzable chlorine as an encapsulant for the electrical and electronics industry, chlorine is hydrolyzed due to moisture absorption and liberated with chlorine ions, thereby lowering the electrical insulation of electrical and electronic materials, There is a problem of causing various problems such as corroding the lead wire and cracking of the sealing material.

In particular, it is essential to minimize the hydrolyzable chlorine content of the novolak-type epoxy resin used as the encapsulant material of an integrated circuit used as a semiconductor.

In addition, novolak-type epoxy resins prepared from novolak-type phenolic resins containing impurities such as unreacted raw materials or catalysts may cause a large amount of impurities due to side reactions, resulting in lowered yields and dechlorination in the epoxy resins. The content of hydrolyzable chlorine increases due to the formation of difficult side reactions.

For these reasons, it is necessary to prepare an epoxy resin from a high-purity novolak-type phenolic resin from which impurities such as unreacted raw materials and a catalyst are removed, thereby producing a high-purity novolak-type epoxy resin having a low content of hydrolyzable chlorine. It has emerged.

Various preparation methods for reducing hydrolyzable chlorine in the production of epoxy resins have been proposed. US Pat. No. 4,137,220 discloses a continuous process by azeotropically combining water and epiglohydrohydron at a temperature of 60 to 80 ° C. under reduced pressure. A method of preparing a novolac epoxy resin by continuously dropping an aqueous alkali metal hydroxide solution at 40 to 50 ° C. while removing water was proposed. However, the epoxy resin obtained in this method is usually 1000 ppm due to the formation of a side reaction product which is relatively difficult to dechlorinate. It has a high hydrolyzable chlorine content as described above, the removal of the side reactions after the end of the reaction a lot of emulsification occurs, it is difficult to remove the by-products, there is a problem that the yield is lowered.

Japanese Unexamined Patent Publication No. 60-31517 discloses a non-protic polar solvent, and Japanese Unexamined Patent Publication No. 60-31516 discloses a cyclic or linear ether compound and an aprotic polar solvent, and Japanese Unexamined Patent Publication No. 60-31516. Patent Publication No. 63-208583 discloses a method for producing a high purity epoxy resin by continuously dropping alkali metal hydroxides while continuously removing water in the presence of an aromatic hydrocarbon solvent and an aprotic polar solvent. Due to the large amount of side reactions which are relatively difficult to dechlorinate, hydrolyzable chlorine cannot be sufficiently reduced, and the formation of gelling leads to the formation of a large amount of emulsified layers, making it difficult to remove the side reactions. It requires a lot of energy in order to increase the price. Mothada.

Japanese Patent Application Laid-Open No. 5-17463 uses a linear ether compound and an aprotic polar solvent in combination to provide a solid alkali metal hydroxide while controlling the water content in the system to 0.1 to 4.0 wt% at a temperature of 80 ° C. or lower and atmospheric pressure. After the reaction, a method of preparing a high-purity epoxy resin was proposed by carrying out a purification reaction after the reaction.However, in this preparation method, epichlorohydrin is decomposed during the reaction when the aprotic polar solvent and the ether compound are used together. Due to the occurrence of gelation, the yield of the product is lowered and the solid alkali metal hydroxide is collectively added, so that the heat generation is severe during the reaction, and the reaction temperature is difficult to control. There is a problem falling.

In addition, in order to improve the yield in the production of epoxy resin and to reduce the hydrolyzable chlorine content, various changes to the process were examined. In Japanese Patent Laid-Open Nos. Hei 2-150412 and Hei 2-150413 after filtration and washing, Although the method of removing and purifying the produced salt by centrifugation has been proposed, this method is somewhat effective in improving the yield. However, the energy consumption during centrifugation and the process time are long, resulting in a cost increase and hydrolyzability. It does not affect the reduction of chlorine content and is not good for industrial use. In Japanese Laid-Open Patent Publication No. 60-186522, a method of fusion reaction of a free amine anion exchange resin at 10 to 50 ° C. for 5 to 100 hours has been proposed. In Japanese Laid-Open Patent Publication No. 60-199019, an OH-type infectious group anion exchange is proposed. A method of fusion with a resin has been proposed. These methods require a long fusion time, a problem of cost increase resulting from the exchange of anion exchange resin, and a reduction effect of chlorine.

When unreacted phenols or catalysts remain in the novolak-type phenolic resin in the above-mentioned epoxy resin production method, the yield decreases due to the progress of the side reactions by the unreacted raw materials and the promotion of the side reactions by the remaining catalysts, and desalination. Due to the indigestion of the side reactions that are difficult to digest, the epoxy resin contains a lot of hydrolyzable chlorine, which results in worse results.

Accordingly, it is necessary to examine the production of high-purity novolak-type phenolic resins, and in particular, the conventional method for producing a novolak-type phenolic resin has an unreacted raw material and It is difficult to remove the catalyst, and it is difficult to reduce the impurities to a minimum because dehydration reaction at a high temperature of 200 ° C. or higher in order to reduce the content of impurities increases the foreign substances due to the oxidation reaction of the resin itself.

Various methods have been proposed for producing a novolak-type phenolic resin in which impurities are removed from phenols. In Japanese Laid-Open Patent Publication No. 60-262815, phenols and aldehydes are reacted under an acidic catalyst to remove dehydration and unreacted substances. Japanese Laid-Open Patent Publication No. 61-34009 discloses a method for blowing an inert gas while heating it to 150 ° C. or lower, and dehydrating by reacting phenols and aldehydes under an acidic catalyst, followed by distillation by blowing water or water and an inert gas. Although a manufacturing method is disclosed, it is difficult to completely remove an unreacted raw material and a residual catalyst by this manufacturing method. When the epoxy resin is prepared from such a novolak-type phenolic resin, the yield of the novolak-type epoxy resin is due to the ring opening of the epoxy ring by the acidic catalyst, the progress of the side reaction by the unreacted raw material, and the generation of the side reaction which is difficult to dechlorination. Not only is this lowered, but also the content of hydrolyzable chlorine in the epoxy resin is increased.

The present invention produces a high-purity novolak-type phenolic resin containing almost no unreacted phenols and catalysts that can solve the above problems, and yields a high-purity novolak-type epoxy resin having a low content of hydrolyzable chlorine therefrom. The purpose is to provide a good manufacturing method.

That is, the phenols of the present invention and the aldehydes are reacted under an acid catalyst, and then a hydrophobic organic solvent is added to dissolve the novolak-type phenolic resin, and the content of unreacted phenols is 20 ppm or less, and the amount of the remaining catalyst is 0.2 ppm. Hereinafter, water and filtration were prepared to produce a high-purity novolak-type phenolic resin in an amount of 1 ppm or less of other unreacted materials and an electric conductivity of 5.0 kV / cm or less, and then reacted with epichlorohydrin in the presence of an alkali metal hydroxide. After aging, a novolak-type epoxy resin was prepared, and excess epichlorohydrin was recovered. The novolak-type epoxy resin was dissolved in a hydrophobic organic solvent, and then secondaryly purified with an aqueous solution of an alkali metal hydroxide to obtain a high-purity novolak-type epoxy resin. Prepare a resin.

Hereinafter, the present invention will be described in more detail.

The present invention produces a novolak-type phenolic resin by reacting phenols and aldehydes under an acid catalyst, wherein the phenols and aldehydes are present in the presence of water or 1 to 5 carbon atoms or ketones based on 100 parts by weight of phenols. 30 parts by weight is added to react under an acid catalyst, and when the reaction is completed, 200 to 300 parts by weight of a hydrophobic organic solvent is added to 100 parts by weight of the resin to completely dissolve the novolak-type phenolic resin, which is then left to stand for water vapor (lower layer). ) And the resin layer (upper part) to remove the lower layer of water, and then 30-100 parts by weight of deionized water or distilled water is added to 100 parts by weight of the resin, and the content of unreacted phenols is 20 ppm or less, and the amount of remaining catalyst is 0.2 ppm or less. Water and other unreacted substances to 1 ppm or less, and an electric conductivity of 5.0 kW / cm or less, and after filtering the resin containing the solvent, By collecting the thereby producing a novolak type phenolic resin.

The novolak-type phenolic resin thus prepared is reacted with epichlorohydrin in the presence of alkali metal hydroxide at 40 to 110 ° C. under atmospheric pressure or reduced pressure for 30 to 120 minutes, and then aged for 30 to 120 minutes. An epoxy resin was prepared, and excess epichlorohydrin was recovered, and then a novolak-type epoxy resin was dissolved in a hydrophobic organic solvent, and 10 to 10 equivalents of alkali metal hydroxide was added to 1 equivalent to 1 equivalent of the hydrolyzable chlorine component of the epoxy resin. The secondary purification reaction is carried out for 30 to 180 minutes while maintaining the 50 to 90 ℃ in 50 parts by weight aqueous solution to produce a high purity novolak-type epoxy resin.

The phenols used in the present invention are one kind or a mixture of two or more kinds having a phenol group hydroxyl group such as phenol, o-cresol, p-cresol, m-cresol, resorcinol, bisphenol A and xylenol.

The aldehydes use one selected from formalin, paraformaldehyde and acetaldehyde.

As the acid catalyst, organic or indefinite such as sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, oxalic acid, acetic acid, maleic acid, benzenesulfonic acid, paratoluenesulfonic acid, sulfaic acid and the like are used.

Hydrophobic organic solvents used for easy removal of remaining salts and separation of water from resins are aromatic hydrocarbons such as xylene, toluene and benzene, ketones such as methyl ethyl ketone and methyl isobutyl ketone, or a mixture of two or more thereof. The usage-amount is 200-300 weight part with respect to 100 weight part of resin. When the amount of the solvent exceeds 300 parts by weight, it takes a long time for the recovery of the solvent. When the amount of the solvent is 200 parts by weight or less, the separation of the resin and the water layer takes a very long time and the productivity is lowered.

In addition, water uses water with few impurities, such as pure water purified by distilled water and ion-exchange resin, and the water temperature is preferably about 60 to 100 ° C, particularly preferably 80 to 100 ° C.

Below this temperature, there is a possibility that dissolved oxygen of water remains, so discoloration of phenol occurs and resin entanglement occurs.

The epichlorohydrin is used in the amount of 1 to 15 equivalents to 1 equivalent of the phenolic hydroxyl group of the novolac phenolic resin.

In the epoxidation reaction of a novolak-type phenolic resin, one or two or more mixed solvents of alcohols, ketones, linear or cyclic ether compounds, and aprotic polar solvents may be added to promote the reaction as necessary. Alternatively, the compatibility between water and the epichlorohydrin layer may be increased, and the amount of use thereof may vary depending on the type of solvent, but may be 0.5 to 100 parts by weight based on the epichlorohydrin used.

Alkali metal hydroxides are composed of 0.95 to 1.05 equivalents of granules, granules, plates or powders of solid or 30 to 50% by weight of sodium hydroxide or potassium hydroxide, or the like, based on 1 equivalent of phenolic hydroxyl groups of the novolac phenolic resin. The reaction can be carried out at a reduced pressure or normal pressure, and the epichlorohydrin recovered by azeotroping with water is condensed and separated to reflux to the reactor.

Also in the secondary purification reaction, one or two or more mixed solvents of alcohols, aprotic polar solvents and linear or cyclic ether compounds can be added as necessary to enhance the purification effect. In this case, the amount of the solvent is preferably about 1 to 15 parts by weight based on the novolac phenolic resin.

Hereinafter, the manufacturing method of the present invention will be described in more detail with reference to the following examples, but the following examples do not limit the scope of the present invention.

[Example, Comparative Example]

* Production of novolac type phenolic resin

Example 1

1,000 g of o-cresol and 10 g of p-toluene sulfonic acid are added to a vessel equipped with a reflux condenser, a thermometer, and a stirrer, and the temperature is raised to 100 ° C. while stirring. When the temperature increase is completed, formaldehyde 600g, a 37% aqueous solution, is added at a uniform rate for 150 minutes and a holding reaction is carried out for 30 minutes to synthesize o-cresol novolak-type phenolic resin (1).

2,000 g of methyl isobutyl ketone (MIBK) is added here to dissolve a novolak-type phenolic resin. It is left to stand for 30 minutes, and it separates into a water layer (lower layer) and a resin layer (upper layer), and removes water of a lower layer. Again, 600 g of water at 85 ° C. was added, followed by washing with water. After washing with water, the MIBK is recovered at the first atmospheric pressure, and the solution temperature is secondarily recovered at 160 ° C. for 30 minutes at a reduced pressure of about 5 Torr to prepare a high-purity o-cresol novolak-type phenolic resin (2).

The analysis results of impurities contained in the novolak-type phenol-based resin (o-cresol novolak phenol resin) thus prepared are as follows.

Unreacted Phenols: 0.0%

Unreacted aldehydes: 1.0 ppm

Remaining catalyst: 0.1 ppm

* Measuring method

1. Unreacted Phenols: Gas Chromatography

2. Unreacted aldehydes: Acetyl Acetone Method

3. Extraction Water Analysis: After distilled water 90g is added to 100g of resin and extracted at 100 ℃ for 2 hours, the extract water is analyzed.

(1) Na ⁺ : atomic absorption spectrometry

(2) Cl ^-: potentiometric titration method

(3) Residual Catalyst: Ion Chromatography

Comparative Example 1

After synthesizing o-cresol novolac phenolic resin (1) in the same manner as in Example 1, the solution temperature was maintained at 170 ° C. and the reduced pressure was 50 Torr at normal pressure, followed by dehydration until the extract was removed. Cresol novolac phenol resin (2 ') is prepared.

The analysis results of impurities contained in the novolak-type phenol resin (o-cresol novolak phenol resin) thus prepared are as follows.

Unreacted Phenols: 2.0%

Unreacted aldehydes: 300.0 ppm

Remaining Catalyst: 80.0ppm

* Production of novolac type epoxy resin

Example 2

120 g of -cresol novolac phenol resin (2) prepared in Example 1 was dissolved in 648 g of epichlorohydrin and the temperature of the solution was raised to 60 ° C. in a vessel equipped with a reflux cooler, a thermometer and a stirrer. While maintaining the temperature of the solution at 60 ℃, the reaction proceeds while continuously dropping 80.34g of 49.8% by weight aqueous sodium hydroxide solution at a constant rate over 2 hours at 150 Torr under reduced pressure. At this time, epichlorohydrin recovered by azeotropy with water is condensed and refluxed to a reactor and the water layer is separated and removed. When the dropwise addition of the aqueous sodium hydroxide solution is completed, aging is performed for 1 hour under the same conditions. After aging is completed, epichlorohydrin is recovered at a reduced pressure of 5 Torr or less in a temperature not exceeding 150 ° C. When the recovery is completed, 348 g of methyl isobutyl ketone is added to completely dissolve the epoxy resin, 200 g of distilled water is added thereto, stirred, and left to stand for 30 minutes to remove the water layer in a conventional manner. 8.7 g of methanol and 5.0 g of 30% sodium hydroxide were added to the resin solution, followed by purification for 100 minutes at atmospheric pressure while maintaining the temperature at 65 ° C., followed by washing with water to remove reaction by-products and salts, and then filtration and solvent recovery to recover o-cresol. Obtain a novolac epoxy resin.

Example 3

120 g of o-cresol novolac phenol resin (2) prepared in Example 1 was dissolved in 648 g of epichlorohydrin in a vessel equipped with a reflux cooler, a thermometer and a stirrer, and the temperature of the solution was raised to 50 ° C. When the temperature of the solution reaches 50 ° C., 32.4 g of methanol is added, and then, while maintaining the temperature of the solution at 50 ° C., 80.34 g of a 49.8 wt% sodium hydroxide aqueous solution is continuously added dropwise at a constant rate over 2 hours at a reduced pressure of 170 Torr. Proceed. At this time, epichlorohydrin recovered by azeotropy with water is condensed and refluxed to the reactor, and the water layer is separated and removed. When the dropwise addition of the aqueous sodium hydroxide solution is completed, aging is performed for 1 hour under the same conditions. After aging is completed, epichlorohydrin is recovered at a reduced pressure of 5 Torr or less in a temperature not exceeding 150 ° C. When the recovery is completed, 348 g of methyl isobutyl ketone is added to completely dissolve the epoxy resin, 200 g of distilled water is added thereto, stirred, and left to stand for 30 minutes to remove the water layer in a conventional manner. 8.7 g of methanol and 5.3 g of 30% sodium hydroxide were added to the resin solution, followed by purification for 100 minutes at atmospheric pressure while maintaining the temperature at 65 ° C. to remove reaction by-products and salts, followed by filtration and recovery of the solvent to recover o-cresol. Obtain a novolac epoxy resin.

Example 4

120 g of o-cresol novolac phenol resin (2) prepared in Example 1 was dissolved in 648 g of epichlorohydrin and the temperature of the solution was raised to 60 ° C. in a vessel equipped with a reflux cooler, a thermometer and a stirrer. When the temperature of the solution reaches 60 ° C., 32.4 g of methanol is added, and then, while maintaining the temperature of the solution at 60 ° C., 40.8 g of 98% by weight sodium hydroxide is added dropwise at a constant rate or continuously at a constant rate for 2 hours under normal pressure. Proceed. When the dropwise addition of the aqueous sodium hydroxide solution is completed, aging is performed for 1 hour under the same conditions. After completion of aging, 40g of distilled water is added and stirred at the same temperature, and left standing for 30 minutes to remove the reaction product salt by separating and removing the water layer, and recovering epichlorohydrin under a reduced pressure of 5 Torr or less in a temperature not exceeding 150 ° C. . When the recovery was completed, 348 g of methyl isobutyl ketone was added to completely dissolve the epoxy resin. Then, 8.7 g of methanol and 5.3 g of 30% sodium hydroxide were added to the resin solution, followed by purification for 100 minutes at atmospheric pressure while maintaining the temperature at 65 ° C. After removal of by-products and salts, filtration and solvent recovery to obtain o-cresol novolac epoxy resin.

Example 5

120 g of o-cresol novolac resin (2) prepared in Example 1 was dissolved in 648 g of epichlorohydrin in a vessel equipped with a reflux cooler, a thermometer and a stirrer, and the temperature of the solution was raised to 60 ° C. When the temperature of the solution reaches 60 ° C., 0.12 g of tetrabutylammonium bromide is added, followed by reaction under normal pressure for 1 hour while maintaining the temperature of the solution at 60 ° C. to form chloroglycidyl ether of the novolak type phenol resin. Here, 40.8 g of 98% by weight sodium hydroxide is added dropwise continuously at a constant rate or divided portions over 2 hours to enhance the ring closure reaction. When the dropwise addition of the aqueous sodium hydroxide solution is completed, aging is performed for 1 hour under the same conditions. After completion of aging, 40g of distilled water was added and stirred at the same temperature, and then left to stand for 30 minutes to separate and remove the water layer to remove the reaction product salt, and to recover epichlorohydrin under a reduced pressure of 5 Torr or less within a temperature not exceeding 150 ° C. do. When the recovery was completed, 348 g of methyl isobutyl ketone was added to completely dissolve the epoxy resin, and 8.7 g of methanol and 5.3 g of 30% sodium hydroxide were added to the resin solution, followed by purification for 100 minutes at atmospheric pressure while maintaining the temperature at 65 ° C., followed by washing with water. After the reaction by-products and salts are removed, the mixture is filtered and the solvent is recovered to obtain an o-cresol novolac epoxy resin.

Comparative Example 2

A novolak-type epoxy resin was prepared under the same conditions as in Example 2, except that the novolak-type phenol-based resin (2 ') prepared in Comparative Example 1 was used.

Comparative Example 3

A novolak-type epoxy resin was prepared under the same conditions as in Example 3, except that the novolak-type phenol-based resin (2 ') prepared in Comparative Example 1 was used.

[Comparative Example 4]

A novolak-type epoxy resin was prepared under the same conditions as in Example 4 except for using the novolak-type phenolic resin (2 ') prepared in Comparative Example 1.

[Comparative Example 5]

A novolak-type epoxy resin was prepared under the same conditions as in Example 5 except for using the novolak-type phenol-based resin (2 ') prepared in Comparative Example 1.

The results of the Examples and Comparative Examples are shown in Table 1 below.

As can be seen from Table 1, according to the present invention, a highly pure novolak-type phenol resin containing little unreacted phenols and catalysts can be prepared, and from this, a high-purity novolak-type epoxy resin having a small content of hydrolyzable chlorine is obtained. It is possible to produce a good yield.

Claims (11)

In the method for producing a novolak type epoxy resin, phenols and aldehydes are reacted under an acid catalyst, and then 200 to 300 parts by weight of a hydrophobic organic solvent is added to dissolve 100 parts by weight of the novolak type phenolic resin, and then the content of unreacted phenols. 30 to 100 parts by weight of ionic resin or distilled water at 60 to 100 ° C., so that the amount of the remaining catalyst is 0.2 ppm or less, the amount of remaining catalyst is 1 ppm or less, and the electrical conductivity is 5.0 ppm / cm. After the addition of 100 parts by weight and washing with water, the resin layer was filtered to remove the unremoved gelling and side reactions, and the hydrophobic organic solvent was recovered to prepare a high purity novolak-type phenolic resin, and then the novolak-type phenolic resin 1 to 15 equivalents of epichlorohydrin relative to 1 equivalent of phenolic hydroxyl group in is maintained at 40 to 110 ° C in the presence of 0.95 to 1.05 equivalents of alkali metal hydroxide for 30 to 240 minutes. After reacting under reduced pressure or reduced pressure, the mixture was aged for 30 to 120 minutes to produce a novolak-type epoxy resin, and after recovering excess epichlorohydrin, the novolak-type epoxy resin was dissolved in a hydrophobic organic solvent to give an alkali metal hydroxide aqueous solution. Method for producing a novolak-type epoxy resin, characterized in that the secondary purification for 30 to 180 minutes at 50 ~ 90 ℃. The said phenols are 1 type, or 2 or more types of mixtures which have a phenol group hydroxyl group, such as phenol, o-cresol, p-cresol, m-cresol, resorcinol, bisphenol A, and xylenol. The manufacturing method of the novolak-type epoxy resin made into. The method for producing a novolac epoxy resin according to claim 1, wherein the aldehyde is one selected from formalin, paraformaldehyde, and acetaldehyde. According to claim 1, wherein the acid catalyst is an organic or inorganic acid, such as sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid oxalic acid, acetic acid, maleic acid, benzenesulfonic acid, paratoluenesulfone, sulfaic acid, etc. Manufacturing method. The novolak type according to claim 1, wherein the hydrophobic organic solvent is one or two or more mixed solvents selected from aromatic hydrocarbons such as toluene, xylene and benzene, and ketones such as methyl ethyl ketone and methyl isobutyl ketone. Method for producing an epoxy resin. The reaction according to claim 1, wherein the reaction of the phenols and aldehydes under an acid catalyst is carried out in the presence of water or in a state in which 1 to 5 parts by weight of C1-5 alcohols or ketones are added to 100 parts by weight of phenols. Method for producing a novolac type epoxy resin. The method according to claim 1, wherein one or two or more mixed solvents of alcohols, ketones, linear or cyclic ether compounds and aprotic polar solvents are disposed in the reaction of producing an epoxy resin from the novolac phenolic resin. Method for producing a novolac-type epoxy resin, characterized in that. 8. The method for producing a novolac epoxy resin according to claim 7, wherein the amount of the solvent is 0.5 to 100 parts by weight based on epichlorohydrin. The method of claim 1, wherein the alkali metal hydroxide is granule, granule, plate or powder solid or sodium hydroxide or potassium hydroxide in the form of an aqueous solution of 30 to 50% by weight. The mixed solvent according to claim 1, wherein 1 to 15% by weight of alcohols, aprotic polar solvents, linear or cyclic ether compounds with respect to the novolak-type epoxy resin in the second purification is used. A method for producing a novolak type epoxy resin, wherein the reaction is carried out by adding a resin. The furnace according to claim 1, wherein 10 to 50% by weight of the aqueous solution of the alkali metal hydroxide is added in an amount of 1 to 10 equivalents to 1 equivalent of the hydrolyzable chlorine content contained in the epoxy resin. Method for producing a ballolac epoxy resin.