JP2006257445A - Method for producing tetramethylbiphenyl type epoxy resin having low organic halogen content - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an epoxy compound, by which the epoxy compound used for producing epoxy compounds useful in electric, electronic fields, and the like, and having an efficiently stably reduced unpleasant organic halogen content can be produced, while minimizing the loss of epoxy groups. <P>SOLUTION: This method for producing the tetramethylbiphenyl type epoxy resin having a reduced organic halogen content of ≤410 ppm is characterized by mixing or dissolving the tetramethylbiphenyl type epoxy resin having an organic halogen content of up to 5,000 ppm in an organic solvent, adding an alkali metal hydroxide to the mixture liquid or solution to decompose the organic halogen, and then charging the reaction mixture liquid into water to terminate the reaction. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for producing an epoxy compound, which is used for producing an epoxy compound useful in the electric and electronic fields, and which efficiently and stably removes an undesirable organic halogen while minimizing the loss of an epoxy group.

Epoxy resin compositions are used in a wide range of fields such as adhesion, casting, sealing, lamination, molding and painting because of their excellent cured properties and easy handling.
2. Description of the Related Art Conventionally, epoxy resins used for sealing and adhesion of electric and electronic parts are required to have a small amount of halogen contained therein. That is, it is known that the halogen in the epoxy resin that is ionized by hydrolysis adversely affects the electrical insulation or corrodes the lead wire or the like. In particular, when epoxy resin is used as a resin for encapsulants in semiconductor integrated circuits, a small amount of halogen is an essential condition, and as the degree of integration of semiconductor circuits increases, the allowable amount of halogen decreases. Yes.
In fields other than the electrical and electronic fields, the demand for low halogen content has become stricter in order to reduce the generation of harmful substances such as dioxins during incineration.

In general, the epoxy resin most widely used is produced from a compound having a phenolic hydroxyl group, an alcoholic hydroxyl group, a carboxyl group, a primary or secondary amine group and an epihalohydrin. This type of epoxy resin contains inorganic halogens and organic halogens present in the form of 1,2-halohydrin groups, 1,3-halohydrin groups, halomethyl groups, and the like as impurities.
Among these impurity halogens, inorganic halogens and organic halogens present in the form of 1,2-halohydrin can be reduced to a level that does not cause a problem in the prior art. It was difficult to reduce the loss of epoxy groups while keeping the loss low enough.

  In order to produce an epoxy resin with a low content of organic halogen impurities, aprotic polarity is produced during the reaction of a compound having a phenolic hydroxyl group, an alcoholic hydroxyl group, a carboxyl group, a primary or secondary amine group with an epihalohydrin. Patent Documents 1 to 4 show that the selectivity of the reaction is improved by using a solvent or the like to suppress the generation of impurities. However, these methods cannot meet the recent severe requirements.

  Many proposals have also been made for a method of reducing the halogen content by repurifying the epoxy resin once produced. A typical method is to hydrolyze the impurity organic halogen with a basic compound to form a halogen ion, and then remove it by washing or the like. Reaction occurs and the original function of the epoxy resin is likely to be impaired.

  Patent Documents 5 to 7 disclose a method in which an epoxy resin is dissolved in an aprotic polar solvent, and an alkali metal hydroxide is added in a solid or aqueous solution to hydrolyze impurity organic halogen. However, if the alkali metal hydroxide is added in the form of a solid or an aqueous solution, the dispersion in the reaction solution is insufficient and the organic halogen cannot be sufficiently hydrolyzed. If the reaction temperature is increased or the reaction time is increased in order to increase the reaction rate, many epoxy groups are lost. Increasing the amount of aprotic polar solvent used to accelerate the reaction will accelerate the loss of epoxy groups, and the use of large amounts of expensive and difficult to recover aprotic polar solvents Is disadvantageous.

  Furthermore, Patent Documents 8 to 10 show a method of adding an alkali metal hydroxide as a methanol or ethanol solution to a similar solvent system. In this method, the alkali can be sufficiently dispersed. However, since methanol and primary alcohol are highly reactive and easily react with an epoxy group in the presence of an aprotic polar solvent and an alkali, many epoxy groups are lost in this method.

  In addition, in the presence of an aprotic polar solvent and an alkali, the epoxy group is lost over time, so that the reaction can be stopped quickly when the required amount of organic halogen decomposes. It is indispensable to get a stable quality end product. In each of these existing technologies, an inert solvent is added or an alkali is neutralized with an acid to stop the reaction, but the reaction is not completely stopped by these operations. Further, in large-scale industrial production, it takes a long time to add or neutralize the solvent, and there is a drawback that the epoxy group is lost during that time.

As described above, in any of the conventional methods, the amount of the organic halogen impurity cannot be sufficiently and stably reduced while maintaining the loss of the epoxy group at a level causing no practical problem.
JP 58-189223 A JP-A-60-31516 JP-A-60-31517 JP-A-1-66224, etc. JP 63-174981 A JP-A-1-126320 Japanese Patent Laid-Open No. 5-17464 Japanese Patent Laid-Open No. 62-18778 JP-A-62-235314 JP-A-2-47129, etc.

  An object of the present invention is to provide a method for producing an epoxy compound that efficiently and stably removes an undesirable organic halogen while minimizing the loss of an epoxy group.

As a result of conducting various studies to solve the above problems, the present inventors have mixed or dissolved an epoxy compound in a solvent having a specific component and composition, and then converted the alkali metal hydroxide into a secondary alcohol solution. After the addition and reaction at a specific temperature for a specific time, water was added in a short time to completely stop the reaction, thereby achieving its purpose.
This invention includes the manufacturing method of the following epoxy compounds.

(1) Tetramethylbiphenyl type epoxy resin containing organic halogen in an amount up to 5000 ppm by weight is mixed or dissolved in an organic solvent, and then alkali metal hydroxide is added to the mixed solution or dissolved solution to make 20-100 The organic halogen content is reduced to 410 ppm by weight or less, characterized in that the organic halogen decomposition reaction is carried out at a temperature of 0.degree. C. for 0.5 to 5 hours, and the reaction is stopped after the reaction by adding water to the reaction mixture. A process for producing a tetramethylbiphenyl type epoxy resin.

(2) The decomposition reaction is performed at a resin concentration of 5 to 50% by weight using an organic solvent containing at least one selected from toluene, xylene and methyl isobutyl ketone as the organic solvent, (1) A method for producing a tetramethylbiphenyl type epoxy resin, wherein the organic halogen content is reduced to 410 ppm by weight or less.

(3) The alkali metal hydroxide is sodium hydroxide and / or potassium hydroxide, and the decomposition reaction of the organic halogen compound is carried out at a moisture concentration of 2% by weight or less. A method for producing a tetramethylbiphenyl type epoxy resin in which the organic halogen content described in the item 2) is reduced to 410 ppm by weight or less.

(4) Item (1) to (3), wherein the amount of water added to the reaction mixture after the reaction is 0.1 times or more of the total weight of the epoxy resin-containing reaction mixture. The manufacturing method of the tetramethylbiphenyl type epoxy resin by which the organic halogen content of any one of these is reduced to 410 weight ppm or less.

(5) The organic halogen content described in any one of (1) to (4), wherein the alkali metal hydroxide is added as a secondary alcohol solution of the alkali metal hydroxide. A process for producing a tetramethylbiphenyl type epoxy resin in which is reduced to 410 ppm by weight or less.

(6) The organic halogen content according to (5), wherein the secondary alcohol is at least one selected from 2-propanol, 2-butanol, cyclohexanol and methoxy-2-propanol. A process for producing a tetramethylbiphenyl type epoxy resin in which is reduced to 410 ppm by weight or less.

  According to the method of the present invention, an undesirable organic halogen can be efficiently and stably decomposed while minimizing the loss of an epoxy group. It is advantageously used for the production of mold epoxy resins.

  The raw material epoxy resin to be treated by the method for producing an epoxy compound of the present invention is an epoxy compound containing an undesired organic halogen in an amount of up to 5000 ppm by weight, particularly 100 to 5000 ppm by weight. It is an epoxy resin obtained by a method of subjecting a compound having a phenolic hydroxyl group and epihalohydrin to a condensation reaction in the presence of an alkali, particularly a tetramethylbiphenyl type epoxy resin.

  When an epoxy resin having an organic halogen content in the above range cannot be obtained or produced, preliminary purification for reducing the organic halogen content can be performed by a conventionally known method. When the organic halogen content of the raw material compound is too large, an epoxy compound having a sufficiently low organic halogen content cannot be obtained even with the excellent method of the present invention.

In the method of the present invention, the mixed solvent system used for mixing or dissolving the epoxy compound is an organic solvent system containing 3 to 20% by weight of an aprotic polar solvent.
Examples of the aprotic polar solvent include dimethyl sulfoxide, diethyl sulfoxide, dimethyl sulfone, sulfolane, dimethylformamide, dimethylacetamide, hexamethylphosphoramide and the like. Among these aprotic polar solvents, dimethyl sulfoxide is preferable because it is easily available and has excellent effects.

The solvent used with the aprotic polar solvent is an inert solvent other than the above aprotic polar solvent.
Examples include aromatic hydrocarbon solvents such as benzene, toluene and xylene, ketone solvents such as methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone, and ethers such as dioxane and ethylene glycol dimethyl ether. An aromatic hydrocarbon solvent or a ketone solvent is preferable from the viewpoint of easiness of treatment, and particularly, toluene, xylene or methyl isobutyl ketone is preferable. These solvents can be used alone or in combination of two or more.

  The proportion of the aprotic polar solvent in the mixed solvent system used in the method of the present invention is 3 to 20% by weight, preferably 5 to 15% by weight. If the proportion of the aprotic polar solvent is too small, the effect of the present invention is not sufficient, and if the proportion of the aprotic polar solvent is too large, the loss of epoxy groups increases.

  The amount of the mixed solvent system used in the present invention is such that the concentration of the epoxy compound is 3 to 70% by weight, preferably 5 to 50% by weight, and more preferably 10 to 40%. It is the amount which becomes weight%. If the amount of the mixed solvent system used is too small, the loss of the epoxy group increases, and if the amount of the mixed solvent used is too large, the effect of the present invention is not sufficient.

  Mixing or dissolution of the epoxy compound in the mixed solvent system can be performed by a general method. Each component forming the mixed solvent system may be mixed in advance and mixed or dissolved with the epoxy compound at one time, or after mixing or dissolving some components of the mixed solvent system and the epoxy compound, Additional ingredients may be mixed.

In the method of the present invention, an alkali metal hydroxide is used as the secondary alcohol solution. As the alkali metal hydroxide, NaOH or KOH is usually used.
The usage-amount of an alkali metal hydroxide is 0.5-50 mol with respect to 1 mol of organic halogens in an epoxy compound, Preferably it is 1.0-20 mol. If the amount of alkali metal hydroxide used is too small, the effect of the present invention is not sufficient, and if the amount used is too large, the loss of epoxy groups increases.

Examples of the secondary alcohol used here include 2-propanol, 2-butanol, cyclohexanol, methoxy-2-propanol, and the like.
The concentration of the alkali metal hydroxide in the secondary alcohol solution is 2 to 30% by weight, preferably 5 to 20% by weight. If the concentration of the secondary alcohol solution is too low, the loss of epoxy groups increases. If the concentration of the secondary alcohol solution is too high, the alkali metal hydroxide is not sufficiently dissolved or the stability of the solution is deteriorated.

In the method of the present invention, a secondary alcohol solution of an alkali metal hydroxide is added while stirring the organic mixed solvent solution of the epoxy compound at a predetermined temperature, and an organic halogen decomposition reaction is performed. The secondary alcohol solution of alkali metal hydroxide may be added all at once, or may be carried out little by little continuously or intermittently.
The organic halogen decomposition reaction temperature is 20 to 100 ° C, and preferably 40 to 90 ° C. If the reaction temperature is too high, the loss of epoxy groups is large, and if the reaction temperature is too low, the effect of the present invention is not sufficient.

  The organic halogen decomposition reaction time is 0.5 to 5 hours, preferably 0.5 to 3 hours after the start of the addition of the secondary alcohol solution of the alkali metal hydroxide. If the reaction time is too long, the loss of epoxy groups is large, and if the reaction time is too short, the effect of the present invention is not sufficient.

  Since the decomposition reaction in the method of the present invention is affected by moisture, the moisture in the reaction solution is preferably adjusted to a certain range. The amount of water in the reaction solution is preferably 2% by weight or less, more preferably 0.2 to 1.0% by weight. If there is too much water in the reaction solution, the effect of the present invention is not sufficient, and an extra dehydration operation is required to reduce the water in the reaction solution more than necessary, which is industrially disadvantageous.

In the method of the present invention, it is important for the stabilization of the quality of the final product that the reaction is stopped immediately after the predetermined decomposition reaction time of the organic halogen is completed.
The reaction can be stopped by a method such as suddenly lowering the temperature, diluting the solution with an inert solvent, neutralizing the alkali with an acid, or adding excess water. Then, since the reaction can be surely stopped by the simplest operation, a method of adding excess water is preferable.
The amount of water for stopping the reaction is preferably 0.1 times (weight) or more of the total amount of the reaction mixture. Further, the charging is preferably performed in as short a time as possible to quickly stop the reaction, and particularly preferably within 10 minutes.

  It is difficult to stop the reaction rapidly and completely in the operation of drastically lowering the reaction temperature or diluting the solution, so in large-scale industrial production, the epoxy group is lost before the reaction is stopped. There is a risk. In the neutralization method, if the amount of acid is too small, the reaction does not stop completely, and if it is too large, the epoxy group is lost due to the reaction between the acid and the epoxy group. It is necessary to know in advance, but it is very difficult to know its drop equivalent.

  After stopping the reaction, water-soluble impurities such as excess alkali metal hydroxide and produced alkali metal halide are removed by washing with water. This water washing operation can be performed in the same manner as a washing operation generally used for removing water-soluble impurities.

  Prior to this water washing operation, the concentration of the epoxy compound can be adjusted by adding a solvent that is not mixed with water. Any additional solvent can be used as long as it is inert and does not mix with water. However, the aprotic polar solvent used in the decomposition reaction is easy because it can be easily handled after removal and removal. It is preferable to use the same solvent as the above.

At the time of washing with water, the concentration of the epoxy compound in the solvent not mixed with water is 5 to 80% by weight, preferably 10 to 50% by weight.
The water washing operation is carried out by adding 0.1 to 10 times (by weight) of purified water to the total amount of the above-described engineered compound solution, sufficiently stirring and mixing, and then allowing to stand to separate, Remove. The temperature at this time is generally 30 to 120 ° C. The above operation is repeated 2 to 10 times so that the ionic impurities in the final product become a predetermined amount or less. At this time, in order to neutralize the excess alkali metal hydroxide, a small amount of a weak acid such as phosphoric acid, monosodium phosphate, oxalic acid, acetic acid or carbonic acid may be added to the washing water.

  Thereafter, the solvent is removed from the organic layer by evaporation to obtain a final halogenated epoxy compound, which can be removed by a general apparatus method. For example, a batch system using a stainless steel or glass container or a continuous system using a film evaporator or the like can be given as examples. Evaporation conditions can be freely set as long as the volatile content of the final product falls below a specified value, but the final temperature is 50 to 250 ° C. and the pressure is about normal pressure to 1 Torr.

  Although the manufacturing method of the epoxy compound of this invention is further explained in full detail based on an Example and a comparative example below, this invention is not limited by a following example.

The raw material epoxy compounds used in Examples 1 and 2 and Comparative Examples 1 and 2 are as follows.
Commercially available tetramethylbiphenol type epoxy resin (Oilized Shell Epoxy Co., Ltd., trade name “Epicoat YX4000”, epoxy equivalent 186, total organic halogen content 1180 ppm)
The epoxy equivalent was determined by a method according to JIS K7236. The total organic halogen (chlorine) content was determined by subtracting the inorganic chlorine content determined by the method according to ISO 11376 from the total chlorine content determined by the method according to ISO 13651.

Examples 1 and 2
Into a three-liter flask having an internal volume of 3 L equipped with a thermometer, a stirrer, and a condenser tube, the epoxy compound of the type and amount shown in Table 1 and toluene or methyl isobutyl ketone were charged and uniformly dissolved and mixed. The kind and amount of aprotic polar solvent shown in Table 1 were added and mixed, and the temperature was raised to the reaction temperature shown in Table 1. While stirring, a secondary alcohol solution of alkali metal hydroxide of the type and amount shown in Table 1 was added at once. Stirring was continued at the reaction temperature shown in Table 1, and after addition of the alkali metal hydroxide solution, after the time shown in Table 1, the amount of water shown in Table 1 was added over the time shown in Table 1. The reaction was stopped.

The types and amounts of solvents shown in Table 1 were added and mixed uniformly, followed by stirring for 10 minutes. Then, it was left still and separated, and the aqueous layer was removed. Next, 500 ml of a 0.1 wt% aqueous solution of sodium phosphate was added to the organic layer, and the mixture was stirred at 70 ° C. for 10 minutes, and washed with neutralized water. Stirring was stopped and allowed to stand to separate, and the aqueous layer was removed. Further, it was washed twice with 500 ml of warm water at 70 ° C. to remove by-product salts, excess alkali, aprotic biopolar solvent, alcohol and the like. Subsequently, the organic solvent was distilled off from the organic layer under reduced pressure. Finally, it was kept at 10 Torr and 160 ° C. for 30 minutes to remove volatile matter almost completely, thereby obtaining a purified epoxy compound.
Table 1 shows the epoxy equivalent and total organic chlorine content of these epoxy compounds.

Comparative Example 1
A three-liter flask having an internal volume of 3 L equipped with a thermometer, a stirrer, and a cooling tube was charged with the type and amount of the epoxy compound and methyl isobutyl ketone shown in Table 1 and dissolved and mixed uniformly. The aprotic polar solvent of the type and amount shown in FIG. 6 was added and mixed, and the temperature was raised to the reaction temperature shown in Table 1. While stirring, the alkali metal hydroxide solution of the type and amount shown in Table 1 was added all at once. Stirring was continued at the reaction temperature shown in Table 1, 200 g of methyl isobutyl ketone was added after the time shown in Table 1 from the addition of the alkali metal hydroxide solution, and the reaction was stopped by stirring for 10 minutes.

Thereafter, 500 ml of a 0.1% by weight aqueous solution of primary sodium phosphate was added, and the mixture was stirred at 70 ° C. for 10 minutes and washed with neutralized water. Subsequently, the product was washed twice with 500 ml of warm water at 70 ° C. to remove by-product salts, excess alkali, aprotic polar solvent, alcohol and the like. Subsequently, the organic solvent was distilled off from the organic layer under reduced pressure. Finally, it was kept at 10 Torr and 160 ° C. for 30 minutes to remove volatile matter almost completely, thereby obtaining a purified epoxy compound.
Table 1 shows the epoxy equivalent and total organic chlorine content of these epoxy compounds.

Comparative Example 2
A three-liter flask having an internal volume of 3 L equipped with a thermometer, a stirrer, and a cooling tube was charged with the type and amount of the epoxy compound and methyl isobutyl ketone shown in Table 1 and dissolved and mixed uniformly. The aprotic polar solvent of the type and amount shown in FIG. 6 was added and mixed, and the temperature was raised to the reaction temperature shown in Table 1. While stirring, the alkali metal hydroxide solution of the type and amount shown in Table 1 was added all at once. Stirring was continued at the reaction temperature shown in Table 1, and after the time shown in Table 1 from the addition of the alkali metal hydroxide solution, carbon dioxide gas was blown in for 10 minutes to neutralize and the reaction was stopped.

Thereafter, 150 g of methyl isobutyl ketone was added and mixed uniformly. Subsequently, 500 ml of warm water at 70 ° C. was added, and the mixture was stirred for 10 minutes at 70 ° C. and washed with water. Then, stirring was stopped and the mixture was allowed to stand and separated, and the aqueous layer was removed. Subsequently, the mixture was further washed twice with 500 ml of warm water at 70 ° C. to remove by-product salts, excess alkali, aprotic polar solvent, alcohol and the like. Subsequently, the organic solvent was distilled off from the organic layer under reduced pressure. Finally, it was kept at 10 Torr and 160 ° C. for 30 minutes to remove volatile matter almost completely, thereby obtaining a purified epoxy compound.
Table 1 shows the epoxy equivalent and total organic chlorine content of these epoxy compounds.

Claims (4)

  A tetramethylbiphenyl type epoxy resin containing an organic halogen in an amount of up to 5000 ppm by weight is mixed or dissolved in an organic solvent, and then an alkali metal hydroxide is added to the mixed solution or dissolved solution, and the temperature is 20 to 100 ° C. The organic halogen content is reduced to 410 ppm by weight or less, characterized in that the organic halogen decomposition reaction is performed at a temperature of 0.5 to 5 hours, and after the reaction, water is poured into the reaction mixture to stop the reaction. A method for producing a tetramethylbiphenyl type epoxy resin.   The organic halogen-containing composition according to claim 1, wherein an organic solvent containing at least one selected from toluene, xylene and methyl isobutyl ketone is used as the organic solvent, and the decomposition reaction is performed at a resin concentration of 5 to 50% by weight. A method for producing a tetramethylbiphenyl type epoxy resin, the amount of which is reduced to 410 ppm by weight or less.   3. The organic halogen according to claim 1, wherein the alkali metal hydroxide is sodium hydroxide and / or potassium hydroxide, and the organic halogen compound is decomposed at a water concentration of 2% by weight or less. A method for producing a tetramethylbiphenyl type epoxy resin having a content reduced to 410 ppm by weight or less. The amount of water added to the reaction mixture after the reaction is 0.1 times or more of the total weight of the epoxy resin-containing reaction mixture, according to any one of claims 1 to 3. A method for producing a tetramethylbiphenyl type epoxy resin having a halogen content reduced to 410 ppm by weight or less.