JPH0841165A - Production of epoxy resin - Google Patents

Abstract

PURPOSE:To obtain an epoxy resin in a high yield at a high productivity by mixing a phenol compd.-epihalohydrin reaction product with a water-sol. polyvalent metal compd. and a water-base medium and separating the medium from the resulting mixture. CONSTITUTION:An epoxy resin is obtd. by reacting a phenol compd. (e.g. phenol novolak resin) with an epihalohydrin (e.g. epichlorohydrin), mixing the reaction product with a water-sol. polyvalent metal compd. (e.g. calcium chloride) and a water-base medium sufficiently under stirring, and separating the medium from the resulting mixture. A process for producing the resin by reacting the phenol compd. with the epihalohydrin, dissolving the reaction product in an org. solvent. mixing the resulting soln. with an aq. alkali soln. to cause dehydrochlorination, separating the alkali soln. from the reaction system, and mixing the system with the water-sol. polyvalent metal compd. and the water- base medium under stirring is pref. from the viewpoint of the hydrolyzable chlorine content and purity of the finally resulting product.

Description

Detailed Description of the Invention

[0001]

The present invention relates to a crude epoxy resin obtained by the reaction of phenols and epihalohydrin with an aqueous alkaline solution to suppress the emulsion formation when the ring-closing reaction is carried out, and further to the next step of washing with water. 2. A method for producing an epoxy resin, which efficiently separates a resin solution layer from an aqueous solution containing residual alkali and a by-product alkali salt.

[0002]

BACKGROUND OF THE INVENTION Epoxy resins are usually obtained by reacting phenols such as cresol novolac resin or bisphenol A novolac resin with epichlorohydrin in the presence of alkali, and then removing unreacted epihalohydrin by distillation to obtain a crude resin. The crude epoxy resin is dissolved in an organic solvent and reacted by stirring and mixing in the presence of an alkaline aqueous solution, or by washing with water without performing the alkaline aqueous solution, hydrolyzable chlorine is reduced or unreacted. It is obtained through a purification step of removing alkali and by-produced alkali salt generated by the reaction.

However, in this purification step, a part of the aqueous layer containing the resin solution and the aqueous solution such as an alkali is emulsified by stirring and mixing, and when it is allowed to stand and separate, the interface between the resin solution and the aqueous layer is formed. Since an emulsion layer was formed, it was extremely difficult to perform liquid separation. If the emulsion layer is separated and discharged together with an aqueous solution such as an alkali in this state, the resin solution contained in the emulsion layer is also discharged at the same time, which causes problems such as a decrease in the yield of the epoxy resin and an increase in industrial waste. In addition, if the emulsion layer is left in the treatment tank together with the resin solution and is not discharged, a part of the aqueous solution such as alkali containing unreacted alkali and by-produced alkali salt remains in the treatment tank, resulting in insufficient purification. was there.

As a method for solving this problem, there has been known a method in which an emulsion layer is not formed by adding alcohols or ketones.

[0005]

However, in the above-mentioned conventional method of adding alcohols or ketones, the effect of destroying the emulsion layer is not sufficient, so that a large amount of addition is required, and the load amount of wastewater COD / BOD, etc. is required. In addition to the environmental problem of increased production efficiency, the effect of breaking the emulsion layer is low, so that the resin flows out together with the emulsion, resulting in a large loss of the desired resin, resulting in poor production efficiency.

The problem to be solved by the present invention is to provide a method for producing an epoxy resin which has no environmental problems and which is excellent in productivity without causing a loss of a target substance in the epoxy resin production process. It is in.

[0007]

Means for Solving the Problems As a result of intensive studies by the present inventors, they found that the above problems can be solved by using a water-soluble polyvalent metal compound together with an aqueous medium in washing the reaction product. Has been completed.

That is, the present invention is characterized in that a reaction product obtained by reacting phenols with epihalohydrin is mixed with a water-soluble polyvalent metal compound and an aqueous medium, and then the aqueous medium is separated from the system. And a method for producing an epoxy resin.

In the present invention, the reaction between the phenols and epihalohydrin is the same as in the production of known and commonly used epoxy resins, and the conditions are not particularly limited. That is, the desired epoxy resin can be obtained by subjecting phenols and epihalohydrin to an addition reaction in the presence of a reaction catalyst.

The phenols used here are not particularly limited, but examples thereof include phenol novolac resin, cresol novolac resin, naphthol novolac resin, bisphenol A novolac resin, bisphenol F novolac resin, bisphenol S novolac resin and biphenol. E novolac resin, biphenol novolac resin, tetramethyl biphenol novolac resin, resorcin novolac resin, alkylphenol novolac resin, novolac resin obtained by polyaddition reaction of unsaturated cyclic hydrocarbon compound with phenol, cresol, naphthol, or bisphenol A, bisphenol Bis such as F, bisphenol S, biphenol E, tetrabromobisphenol, biphenol, and tetramethylbiphenol Phenols, or dihydroxy naphthalene. Of these, novolak resins are particularly preferable because the effects of the present invention are remarkable.

On the other hand, the epihalohydrin to be reacted with the above-mentioned phenols is not particularly limited, but for example, epichlorohydrin, epibromohydrin,
β-Methylepichlorohydrin and the like can be mentioned, with epichlorohydrin being preferred.

The reaction catalyst used in the reaction of the above-mentioned phenols with epihalohydrin is not particularly limited, but is preferably a basic substance such as sodium hydroxide, potassium hydroxide or lithium hydroxide. Can be mentioned. The form of use thereof may be solid, saturated aqueous solution or dilute aqueous solution, and is not particularly limited.
It is preferable to use a 49% by weight aqueous solution from the viewpoint of productivity or suppressing the mixture of salts into the epoxy resin produced. The amount of the basic substance used is usually 0.9 to 1.3 times the equivalent of the hydroxyl group equivalent of the raw material phenols,
It is preferably 1.0 to 1.2 times equivalent.

The reaction product thus obtained contains an epoxy resin as a main component as a main component, and a part of the halohydrin ether compound in which the ring-closing reaction to the epoxy ring has not proceeded remains as it is. Has become. Although the content of the halohydrin ether compound in the reaction product varies depending on the reaction conditions, it is usually 0.1 to 5% by weight in the reaction product.
Is.

In the present invention, the reaction product may be mixed with a water-soluble polyvalent metal compound and an aqueous medium and stirred, and then the aqueous medium may be separated from the system, but as described in detail below. From the viewpoint of the amount of hydrolyzable chlorine and the purity of the finally obtained target product, the method including the above reaction as step 1 and steps 1 to 5 is particularly preferable.

That is, the reaction of the phenols and epihalohydrin described in detail is step 1, and then, in step 2, the obtained reaction product is dissolved in an organic solvent, an alkaline aqueous solution is mixed to carry out a dehydrochlorination reaction, and then step As 3), after separating the alkaline aqueous solution out of the system, in step 4, the water-soluble polyvalent metal compound and the aqueous medium are mixed and stirred, and in step 5, the aqueous medium is separated out of the system, The content of the halohydrin ether compound can be reduced and the purity can be remarkably improved.

Step 2 is a step of ring-closing the residual halohydrin ether compound by a dehydrochlorination reaction to form an epoxy ring. The organic solvent used here is phenols, which are raw materials for epoxy resin production, and A halohydrin etherified product which is a reaction product of phenols and epihalohydrin, and an organic solvent which dissolves a target epoxy resin but is insoluble or hardly soluble in water, for example, a ketone such as methyl ethyl ketone or methyl isobutyl ketone. Examples of the solvent include aromatic solvents such as toluene, xylene and benzene. Of these, methyl ethyl ketone, toluene, and a mixture thereof are preferable because of their excellent solubility in an epoxy resin.

The amount of the organic solvent used is not particularly limited and varies depending on the kind of the raw material phenols used, but normally, the nonvolatile content is in the range of 20 to 60% by weight, especially 30 to 50% by weight. Used.

As the alkaline aqueous solution used in step 2, any of the basic substances used in step 1 which is the main reaction can be preferably used. The concentration of the aqueous solution is not particularly limited, but is usually 0.1 to 49% by weight, especially 0.1 to 20% by weight.
It is preferably in the weight%. Further, the amount of the alkaline aqueous solution used is usually 0.5 to 10 times equivalent, and preferably 1 to 5 times equivalent to the hydroxyl group in the halohydrin ether compound.

In the reaction of the step 2, specifically, the reaction product obtained through the step 1 is diluted with an organic solvent, and then an alkaline aqueous solution is mixed, and then 50 to 100 in the reactor.
A method of carrying out the reaction under a temperature condition of ° C can be mentioned.

After the reaction in step 2 is completed, step 3
As the alkaline aqueous solution, it is removed from the system. The method for removing the alkaline aqueous solution to the outside of the system is not particularly limited, and it may be separated and removed by static separation.

In the present invention, the water-soluble polyvalent metal compound used in the next step during the dehydrochlorination reaction in step 2 or after the completion of the dehydrochlorination reaction and before the removal of the alkaline aqueous solution in step 3 It is preferable to mix and stir the mixture in order to suppress the generation of emulsion in the step 3, facilitate the separation of the aqueous alkali solution, and further reduce the loss of the target substance.

Specific examples of the water-soluble polyvalent metal compound include:
Any of those described in the following step 4 can be used, and the amount used is not particularly limited, but 10 ppm to 50,0 relative to the total volume in the system immediately before the separation in step 3.
It is preferably in the range of 00 ppm from the viewpoint of the emulsion generation suppressing effect, and particularly preferably from 50 to 10,000 ppm from the viewpoint that this effect becomes remarkable.

By step 3, the alkaline aqueous solution is removed
After that, in step 4, the water-soluble polyvalent metal compound and
And the aqueous medium are mixed and stirred. In this step 4
Examples of the water-soluble polyvalent metal compound used include:
Lucari earth metal compounds, aluminum compounds and ferrous metals
Compound, specifically, calcium chloride,
Halogen such as gnesium, aluminum chloride, ferric chloride
Compounds, aluminum sulfate, sodium aluminate [N
aAlO₂], Sulfuric acid such as sulfates such as ferrous sulfate and ferric sulfate
Salt, potassium aluminum sulfate hydrate [AlK (SO _Four)₂ 12H₂
O], chlorinated coppers [Fe₂(SO_Four)₃ FeCl₃] Such as double salt
Can be mentioned.

Of these, halogen compounds such as calcium chloride and magnesium chloride are particularly preferable from the viewpoint of the effect of suppressing emulsion generation.

The amount of the water-soluble polyvalent metal compound used is not particularly limited, but it is in the range of 10 ppm to 50,000 ppm with respect to the total volume in the system at the time of mixing and stirring in step 4, and the emulsion generation suppressing effect. From the point that this effect becomes remarkable, 50 to 10,000 ppm is preferable.
It is preferred that

The aqueous medium is not particularly limited,
Usually, water is used, but a polar organic solvent compatible with water may be used together. The amount of the aqueous medium used is not particularly limited as long as it can sufficiently wash the resin, but is usually 0.1 to 5 times the weight ratio of the resin, among which washing efficiency and productivity are The amount is preferably 0.2 to 2 times in terms of excellent balance.

The washing in step 4 may be carried out by mixing a resin with a predetermined amount of an aqueous medium and mixing and stirring in a stirrer. At this time, the water-soluble polyvalent metal compound is It may be added at the same time as the aqueous medium, or may be continuously or intermittently mixed in the system during mixing and stirring.

The temperature at the time of adding the water-soluble polyvalent metal compound added in step 4 and the temperature up to step 5 after addition are not particularly limited, and the separation between the resin layer and the aqueous medium is taken into consideration. However, it may be lower than the azeotropic temperature of the reaction system. Specifically, it is preferably in the range of 50 to 100 ° C.

After mixing and stirring in this manner, in step 5, the aqueous medium in which impurities are dissolved is removed to the outside of the system,
The desired epoxy resin can be obtained. The method for removing the aqueous medium outside the system is not particularly limited,
The resin layer can be isolated by static separation.

Hereinafter, the present invention will be described in detail with reference to Examples, but the present invention is not limited to these Examples.

[0031]

【Example】

Example 1 In a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a cooling tube, 100 parts of o-cresol novolac resin was dissolved in 385 parts of epichlorohydrin, and then stirred at 80 ° C. to prepare a 20% sodium hydroxide aqueous solution. After dropping 183 parts over 5 hours, the reaction was continued for 1 hour and then left standing for 5 minutes to discard the aqueous layer.

Next, excess epichlorohydrin present in the organic layer was recovered by distillation to obtain a crude epoxy resin containing chlorohydrin ether. Next, as a chlorohydrin ether ring-closing step, 250 parts of methyl isobutyl ketone was added to the above crude epoxy resin to uniformly dissolve the contents, and then 70 parts of a 1% sodium hydroxide aqueous solution and 0.06 part of calcium chloride were added. Then, the mixture was stirred at 80 ° C. for 1 hour to reduce the amount of hydrolyzable chlorine, and then allowed to stand for 5 minutes to discard the aqueous alkaline solution layer.

Next, as a washing step, 100 parts of water and 0.06 part of calcium chloride were added, and the mixture was stirred at 80 ° C. for 30 minutes to wash the sodium hydroxide and the by-produced alkali salt remaining in the resin solution. Then, the mixture was allowed to stand for 5 minutes and the aqueous layer was discarded.

Further, water was removed from the resin solution by azeotropic distillation, insoluble matter precipitated was removed by filtration, and then methyl isobutyl ketone was distilled off to obtain an epoxy resin.
No emulsion was generated in the two liquid separation steps in this purification step, the loss amount of the epoxy resin in the liquid separation operation was less than 0.5%, and the residual amount of the by-product salt in the resin was 1 p.
It was less than pm.

Example 2 An epoxy resin was obtained in the same manner as in Example 1 except that 0.08 part of magnesium chloride was used in place of calcium chloride in the chlorohydrin ring-closing step and washing step.

No emulsion was generated in the two liquid separation steps in this purification step, the loss amount of the epoxy resin in the liquid separation operation was less than 0.5%, and the residual amount of the by-product salt in the resin was 1 ppm. Was less than.

Example 3 An epoxy resin was obtained in the same manner as in Example 1 except that 0.07 part of aluminum chloride was used in place of calcium chloride in the chlorohydrin ring-closing step and washing step.

No emulsion was generated in the two liquid separation steps in this purification step, the loss amount of the epoxy resin in the liquid separation operation was less than 0.5%, and the residual amount of the by-product salt in the resin was 1 ppm. Was less than.

Example 4 An epoxy resin was obtained in the same manner as in Example 1 except that 0.20 part of aluminum sulfate was used in place of calcium chloride in the chlorohydrin ring-closing step and washing step.

No emulsion was generated in the two liquid separation steps in this purification step, the loss amount of the epoxy resin in the liquid separation operation was less than 0.5%, and the residual amount of the by-product salt in the resin was 1 ppm. Was less than.

Example 5 Sodium aluminate was added in an amount of 0.04 in place of calcium chloride in the chlorohydrin ring-closing and washing steps.
An epoxy resin was obtained in the same manner as in Example 1 except that some parts were used.

No emulsion was generated in the two liquid separation steps in this purification step, the loss amount of the epoxy resin in the liquid separation operation was less than 0.5%, and the residual amount of the by-product salt in the resin was 1 ppm. Was less than.

Example 6 Chlorinated copper oxide [Fe ₂ (SO ₄ ) ₃ Fe was used in place of calcium chloride in the chlorohydrin ring-closing and washing steps.
An epoxy resin was obtained in the same manner as in Example 1 except that 0.10 part of Cl ₃ ] was used.

No emulsion was generated in the two liquid separation steps in this purification step, the loss amount of the epoxy resin in the liquid separation operation was less than 0.5%, and the residual amount of the by-product salt in the resin was 1 ppm. Was less than.

Comparative Example 1 An epoxy resin was obtained in the same manner as in Example 1 except that calcium chloride was not used at all in the chlorohydrin ring-closing step and washing step.

The amount of emulsion generated in the liquid separation step in this purification step was 15% with respect to the amount of the resin solution for the first time, and 2
The second time was 2%, and the loss amount of the epoxy resin in the two liquid separation operations was 6%. The residual amount of the by-product salt in the resin was 2 ppm.

Example 7 In a reaction vessel equipped with a stirrer, a thermometer, a dropping funnel, and a cooling tube, 100 parts of phenol novolac resin was dissolved in 388 parts of epichlorohydrin, and then 80 with stirring.
After 185 parts of a 20% aqueous sodium hydroxide solution was added dropwise at 5 ° C. over 5 hours, the reaction was continued for 1 hour and then allowed to stand for 5 minutes to discard the aqueous layer.

Next, excess epichlorohydrin present in the organic layer was recovered by distillation to obtain a crude epoxy resin containing chlorohydrin ether. Then, as a chlorohydrin ether ring-closing step, 250 parts of methyl isobutyl ketone was added to the obtained crude epoxy resin to uniformly dissolve the contents, and then 65 parts of a 1% sodium hydroxide aqueous solution and 0.06 part of calcium chloride were added. Was added, and the mixture was stirred at 80 ° C. for 1 hour to reduce the amount of hydrolyzable chlorine, and then allowed to stand for 5 minutes to discard the aqueous alkaline solution layer.

Next, as a washing step, 100 parts of water and 0.06 part of calcium chloride were added, and the mixture was stirred at 80 ° C. for 30 minutes to wash sodium hydroxide and by-produced alkali salts remaining in the resin solution. Then, the mixture was allowed to stand for 5 minutes and the aqueous layer was discarded.

Further, water was removed from the resin solution by azeotropic distillation, insoluble matter precipitated was removed by filtration, and then methyl isobutyl ketone was distilled off to obtain an epoxy resin.
No emulsion was generated in the two liquid separation steps in this purification step, the loss amount of the epoxy resin in the liquid separation operation was less than 1%, and the residual amount of the by-product salt in the resin was 1 ppm.
Was less than.

Comparative Example 2 An epoxy resin was obtained in the same manner as in Example 7 except that calcium chloride was not used at all in the chlorohydrin ring-closing step and the washing step.

The amount of emulsion generated in the liquid separation step in this purification step was 10% with respect to the amount of resin solution in the first time, and 2
The third time was 3%, and the loss amount of the epoxy resin in the two liquid separation operations was 5%. The residual amount of the by-product salt in the resin was 3 ppm.

Comparative Example 3 Calcium chloride was not used in the ring-closing step and methanol 5 was used instead of calcium chloride in the washing step.
An epoxy resin was obtained in the same manner as in Example 7 except that 0 part was used.

The amount of emulsion generated in the liquid separation step in this purification step was 5% with respect to the amount of the resin solution in the first time and 2% in the second time, and the loss amount of the epoxy resin in the second liquid separation operation was 3%. Met. The residual amount of the by-product salt in the resin was 2 ppm.

The above results are summarized in Table 1.

[0056]

[Table 1] In Table 1, the amount of emulsion generated is a value relative to the amount of resin solution.

[0057]

EFFECT OF THE INVENTION According to the present invention, in the production of epoxy resin, there is no increase in industrial waste, environmental problems such as the load amount of wastewater COD / BOD, etc., and no economical burden, and a resin solution is obtained in a short time. It is possible to separate an aqueous solution such as alkali and the like, and it is possible to remarkably improve the productivity without causing a loss of a target substance in the epoxy resin manufacturing process.

Claims (10)

[Claims] 1. A reaction product obtained by reacting phenols with epihalohydrin, a water-soluble polyvalent metal compound and an aqueous medium are mixed, and then the aqueous medium is separated from the system. Production method. 2. A phenol is reacted with epihalohydrin (step 1), the obtained reaction product is dissolved in an organic solvent, and then an aqueous alkali solution is mixed to carry out a dehydrochlorination reaction (step 2). The method according to claim 1, wherein after the aqueous solution is separated from the system (step 3), the water-soluble polyvalent metal compound and the aqueous medium are mixed and stirred (step 4), and then the aqueous medium is separated from the system (step 5).
The manufacturing method described. 3. The production method according to claim 2, wherein the water-soluble polyvalent metal compound is mixed during the dehydrochlorination reaction of step 2 or after the completion of the dehydrochlorination reaction, and then the alkaline aqueous solution is separated out of the system. . 4. The amount of the water-soluble polyvalent metal compound and the aqueous medium used in step 4 is such that the former is 10 ppm to 50,000 ppm with respect to the total volume in the system, and the latter is a weight ratio to the resin. The method according to claim 2 or 3, wherein the amount is 0.1 to 5 times. 5. The method according to claim 1, 2, 3 or 4, wherein the water-soluble polyvalent metal compound is an alkaline earth metal compound, an aluminum compound or an iron compound. 6. The alkaline earth metal compound, the aluminum compound and the iron compound are halogen compounds.
The manufacturing method described. 7. The method according to claim 5, wherein the alkaline earth metal compound, the aluminum compound and the iron compound are sulfates. 8. The production method according to claim 5, wherein the aluminum compound and the iron compound metal compound are double salts. 9. The production method according to claim 1, wherein the organic solvent used in step 2 is an aromatic solvent or a ketone solvent. 10. The production method according to claim 1, wherein the phenol is a novolac resin.