JP2022102229A - Process for producing epoxy compound - Google Patents

Abstract

To provide a process in which: during the production of an epoxy compound, it is possible to inhibit an excessive addition reaction between halohydrin ether which is an intermediate, and epihalohydrin.SOLUTION: A process for producing an epoxy compound includes the step of performing an addition reaction between a compound having an alcoholic hydroxy group and epihalohydrin with butyl tin-trichloride used as a catalyst.SELECTED DRAWING: None

Description

The present invention relates to a method for producing an epoxy compound.

The epoxy compound can be cured with various curing agents to form a cured product having excellent mechanical properties, water resistance, chemical resistance, heat resistance, electrical properties and the like. Therefore, it is used in a wide range of fields such as adhesives, paints, laminated boards, molding materials, and casting materials.

The aliphatic glycidyl ethers, which are one of the epoxy compounds, are added with epihalohydrin and a compound having an alcoholic hydroxyl group (also referred to as an alcohol compound in the present specification) in the presence of a Lewis acid catalyst such as a boron trifluoride ether complex. It can be synthesized through a step of synthesizing halohydrin ether which is an intermediate by the reaction (step 1) and a step of allowing an alkali to act on the halohydrin ether to carry out a ring-closing reaction in the molecule (step 2). Here, the halohydrin ether, which is the product of the addition reaction in step 1, is an alcohol compound having an alcoholic hydroxyl group, similar to the raw material alcohol compound. When a boron trifluoride ether complex generally used in the production of aliphatic glycidyl ether is used as a Lewis acid catalyst, the hydroxyl group of the alcohol compound as a raw material and the hydroxyl group of the halohydrin ether as a product are distinguished. In the addition reaction step, the halohydrin ether and epihalohydrin react with each other, and an excess adduct is also produced, so that the purity is lowered. When the excess adduct is brought into the ring closure reaction in step 2, an epoxy compound containing a high concentration of halogen is produced, and the obtained epoxy compound may be corroded by halogen, and high reliability is required. It is difficult to use for electronic material applications.

In order to prevent the above-mentioned excess addition, conventionally, a method is known in which a large excess amount of alcohol is used in the addition reaction and the residual alcohol is distilled off under reduced pressure after the addition reaction. However, this method reduces yields and requires more cost to remove large amounts of residual alcohol. There has been a need for a new method that can prevent excessive addition even under conditions where the excess amount of alcohol is reduced.

Patent Document 1 discloses a method for producing a high molecular weight linear epoxy resin by preventing an excessive addition reaction by using tin chloride as a Lewis acid catalyst in the addition reaction between diglycidyl ether and a polyol. ..

Japanese Unexamined Patent Publication No. 7-90050

An object of the present invention is to suppress an excessive addition reaction between an intermediate halohydrin ether and epihalohydrin during the production of an epoxy compound.

As a result of searching for a Lewis acid catalyst capable of preferentially catalyzing the reaction between the alcohol compound as a raw material and epihalohydrin, the present inventors have found that the excessive addition reaction can be suppressed when butyltin trichloride is used, and the present invention has been made. Was completed.

That is, the present invention relates to a method for producing an epoxy compound, which comprises a step of carrying out an addition reaction between a compound having an alcoholic hydroxyl group and epihalohydrin using butyl tin trichloride as a catalyst.

It is preferable to carry out the addition reaction in the absence of a solvent.

It is preferable that the alcoholic hydroxyl group is a primary hydroxyl group.

The epoxy equivalent of the epoxy compound is preferably 300 or less.

The number average molecular weight of the epoxy compound is preferably 1000 or less.

Further, it is preferable to include a step of ring-closing the halohydrin ether compound obtained in the addition reaction step with an alkali.

The present invention also relates to a method for producing a halohydrin ether compound, which comprises a step of carrying out an addition reaction between a compound having an alcoholic hydroxyl group and epihalohydrin using butyl tin trichloride as a catalyst.

In the method for producing an epoxy compound of the present invention, the excessive addition reaction between the intermediate halohydrin ether and epihalohydrin can be suppressed.

The schematic diagram of the flow reaction using a single mixer is shown. The schematic diagram of the flow reaction using a plurality of mixers is shown. The schematic diagram of the flow reaction of Example 3 is shown. The schematic diagram of the flow reaction of Example 5 is shown.

<< Manufacturing method of epoxy compound >>
The method for producing an epoxy compound of the present invention is characterized by comprising a step of performing an addition reaction between a compound having an alcoholic hydroxyl group and epihalohydrin using butyl tin trichloride as a catalyst.

<Addition reaction process>
The compound having an alcoholic hydroxyl group is not particularly limited as long as it is a compound that reacts with the epoxy group in epihalohydrin, and among these, the difference in reactivity of the intermediate halohydrin ether with the hydroxyl group becomes large. A compound having a class hydroxyl group is preferable.

Examples of the compound having an alcoholic hydroxyl group include primary monoalcohols such as methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol, 2-ethylhexanol, lauryl alcohol and benzyl alcohol, ethylene glycol and 1,4. -Primary diols such as butanediol and 1,6-hexanediol, primary polyols such as trimethylolpropane, trimethylolethane and pentaerythritol, glycerin, erythritol, xylitol, sorbitol, 3-methyl-1,3- Polycarbonates having both primary and secondary hydroxyl groups and / or tertiary hydroxyl groups such as butanediol and phytantriol, 2-butanol, 2-pentanol, 3-pentanol, cyclohexanol, hydrogenated bisphenol and the like. Examples thereof include tertiary alcohols such as secondary alcohols, 2-methyl-2-propanol and t-butyl alcohol, and alkylene oxide adducts such as ethylene oxide and propylene oxide. Among these, primary alcohols are preferable, and monohydric or divalent primary alcohols are more preferable because excess adducts are less likely to be generated. The alcohol has preferably 1 to 20 carbon atoms. Particularly preferred alcohols include 2-ethylhexanol, lauryl alcohol, 1,4-butanediol, 1,6-hexanediol and trimethylolpropane. Further, examples thereof include compounds having functional groups other than alcoholic hydroxyl groups and alcoholic hydroxyl groups, such as hydroxy acids having both alcoholic hydroxyl groups and carboxyl groups such as citric acid, malic acid, tartaric acid and glycolic acid.

Examples of epihalohydrin include epichlorohydrin, epibromohydrin, epiiodohydrin and the like. Of these, epichlorohydrin is preferred because it is easy to handle and inexpensive. These epihalohydrins may be used alone or in combination of two or more.

これに対し、本発明ではブチル錫トリクロライドが原料アルコール化合物とエピハロヒドリンとの反応を優先的に触媒するため、過剰付加反応を抑制できる。 In the conventional method of synthesizing halohydrin ether by an addition reaction between epihalohydrin and alcohol in the presence of a Lewis acid catalyst such as a boron trifluoride ether complex, an excess consisting of epihalohydrin and the product halohydrin ether is used. Additives will also occur. The product of the overaddition reaction includes a compound of the following formula (I) in which two molecules of epichlorohydrin are reacted with 2-ethylhexanol, and a compound of the following formula (II) in which three molecules of epichlorohydrin are added to 1,6-hexanediol. Can be mentioned.

On the other hand, in the present invention, butyltin trichloride preferentially catalyzes the reaction between the raw material alcohol compound and epihalohydrin, so that the excessive addition reaction can be suppressed.

The molar ratio of the compound having an alcoholic hydroxyl group to epihalohydrin (alcoholic hydroxyl group / epihalohydrin of the compound having an alcoholic hydroxyl group) is preferably 0.9 to 3.0 in the case of a monoalcoholic compound having one alcoholic hydroxyl group. , 0.9 to 2.0 is more preferable, and 0.95 to 1.5 is even more preferable. Below 0.9, epihalohydrin tends to remain, and above 3.0, it tends to take a long time to remove excess alcohol. In the case of polyols having 2 or more alcoholic hydroxyl groups, the molar ratio of alcoholic hydroxyl group / epihalohydrin of the compound having alcoholic hydroxyl group is preferably 0.7 to 2.0, more preferably 0.7 to 1.5. 0.7 to 1.3 is more preferable. If it is less than 0.7, epihalohydrin tends to remain, and if it exceeds 2.0, unreacted hydroxyl groups remain and monoadducts tend to increase.

The amount of butyl tin trichloride used is preferably 0.01 to 10 mol%, more preferably 0.1 to 5 mol%, still more preferably 0.3 to 3 mol% with respect to epihalohydrin. If it is less than 0.01 mol%, the reaction tends to be slow, and if it exceeds 10 mol%, the side reaction tends to increase.

The addition reaction may be carried out in the presence of a solvent such as toluene, xylene, n-hexane, cyclohexane, diisopropyl ether and ethylene glycol dimethyl ether in order to suppress the side reaction, but the side reaction may be carried out by using butyl tin trichloride. Since it can be sufficiently suppressed, it can also be carried out in a solvent-free system.

The addition reaction between the compound having an alcoholic hydroxyl group and epihalohydrin can be suitably carried out by either a flow treatment or a batch treatment.

When the addition reaction is carried out by flow processing, as the flow reaction apparatus, an apparatus including a plurality of liquid feed pumps, a mixer, a residence time unit, and a constant temperature bath as shown in FIG. 1 can be used. When the reaction is carried out at a temperature exceeding the boiling point of the reaction solution, the reaction can be carried out without vaporization by further adding a back pressure regulator. Butyl tin trichloride, a compound having an alcoholic hydroxyl group, and epihalohydrin are pumped and passed through a dwell time unit installed in a constant temperature bath through a mixer. At this time, the reaction proceeds in the process of passing through the residence time unit. The three-way liquid feeding method is not particularly limited, and a multi-stage flow reactor as shown in FIG. 2 is assembled, and a compound having an alcoholic hydroxyl group and epihalohydrin are fed by two pumps, respectively, and one is used. After mixing with an eye mixer, butyl tin trichloride is sent by a third pump and mixed with a mixture of a compound having an alcoholic hydroxyl group and epihalohydrin with a second mixer, or butyl tin trichloride in advance. And a compound having an alcoholic hydroxyl group are mixed, and the mixture and epihalohydrin are each pumped and mixed with a mixer. When the compound having an alcoholic hydroxyl group is solid at room temperature, a method of heating to the melting point of the compound and sending the liquid, or a method of dissolving the compound in a soluble solvent and sending the liquid as a solution can be mentioned. ..

As the mixer used for the flow device, an α-type micromixer (manufactured by MiChS Co., Ltd.), a T-shaped mixer such as Unionty, a turbulent flow type mixer such as a β-type mixer (manufactured by MiChS Co., Ltd.), or the like can be used. The inner diameter (flow path width) of the mixer is appropriately selected according to the reaction scale, and a mixer of 70 μm to 1/8 inch (3,175 μm) can be used.

The residence time of the flow treatment is preferably 0.1 to 60 minutes, more preferably 1 to 30 minutes. At 0.1 minutes, the reaction conversion rate tends to be low, and after 60 minutes, productivity tends to decrease.

The inner diameter of the residence time unit for the flow treatment is preferably 0.1 to 10 mm, more preferably 0.5 to 5.0 mm. If it is less than 0.1 mm, it tends to be impossible to send the liquid due to the pressure loss in the residence time unit, and if it exceeds 10 mm, the solution flowing in the residence time unit is not sufficiently heated and the conversion rate tends to decrease. be. The length of the residence time unit is preferably 1 to 50 m. The flow rate of the flow treatment can be arbitrarily set according to the charging ratio (molar ratio) of the chemical liquid to be sent, the residence time, the length of the residence time unit, and the inner diameter.

When the addition reaction is carried out by batch treatment, the mixing order of butyltin trichloride, the compound having an alcoholic hydroxyl group, and epihalohydrin is such that when excess epihalohydrin and butyltin trichloride are mixed, the reaction such as polymerization of epihalohydrin proceeds. Therefore, it is preferable to mix butyltin trichloride and a compound having an alcoholic hydroxyl group in advance, then add epihalohydrin to the dropping, and allow the reaction to proceed even after the dropping is completed. Since this reaction is an exothermic reaction, the dropping time of epihalohydrin may be adjusted according to the cooling capacity of the reaction apparatus so as to maintain a predetermined reaction temperature, but 0.5 to 10 hours is preferable and 1 to 5 is preferable. Time is more preferable. If it is less than 0.5 hours, it tends to be difficult to control heat generation, and if it exceeds 10 hours, there is a risk that the purity may decrease due to a side reaction.

The reaction time of the batch treatment is usually the time until the epihalohydrin is completely consumed, preferably 0.1 to 5 hours, more preferably 0.5 to 3 hours. Epihalohydrin tends to remain after less than 0.1 hours, and the purity tends to decrease after 5 hours. The reaction time means the time for advancing the reaction after the completion of dropping of epihalohydrin.

In both the flow treatment and the batch treatment, the reaction temperature is preferably 10 to 140 ° C, more preferably 30 to 100 ° C. Below 10 ° C, the reaction time tends to be long and productivity tends to decrease, and above 140 ° C, the purity tends to decrease due to side reactions.

<Ring closure process>
An epoxy compound is obtained through a step of ring-closing the halohydrin ether compound obtained in the addition reaction step with an alkali.

Examples of the alkali used in the ring closing step include sodium carbonate, potassium carbonate, sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide and the like, but sodium hydroxide is preferable. The ring closure step may be performed after removing the catalyst from the addition reaction step, but it may also be performed without removing the catalyst. Alkali may be added as it is or may be added as an aqueous solution. Alkali is preferably charged separately or dropped. The alkali addition time is preferably 0.5 to 5 hours.

The amount of the alkali added in the ring closing step is preferably 0.9 to 2.0 equivalents, more preferably 0.95 to 1.5 equivalents, based on the number of halohydrin groups present in the addition reaction step. Alkali is preferably added as, for example, a 5-60% aqueous solution. The temperature of the ring closure reaction is preferably 10 to 90 ° C. Below 10 ° C, the reaction tends not to proceed, and above 90 ° C, the generated epoxy groups tend to polymerize and the purity tends to decrease. The reaction time is preferably 0.5 to 5 hours. Here, the reaction time means the time for the reaction to proceed after the addition of the alkali.

The ring closure reaction time with alkali is preferably 0.1 to 3 hours. The ring closure reaction can be suitably performed by either a flow treatment or a batch treatment. When the ring closure reaction is carried out by the flow treatment, the flow rate of the flow treatment is appropriately set according to the capacity and the residence time of the residence time unit.

The halohydrin ether compound obtained in the addition step and the epoxy compound obtained in the ring closing step can be measured by gas chromatography. At the end of the addition reaction step, the product of the overaddition reaction is preferably 23% or less, more preferably 20% or less, still more preferably 10% or less of the total area of the peaks obtained by gas chromatography.

The production method of the present invention can be particularly preferably used when the epoxy equivalent of the target epoxy compound is 300 or less, or the number average molecular weight of the epoxy compound is 1000 or less. Since such a low molecular weight epoxy compound has a low molecular weight of the compound having an alcoholic hydroxyl group as a raw material, the amount of excess adduct produced as a by-product is smaller than that in the case of using a compound having a high molecular weight alcoholic hydroxyl group. Even so, the influence on the purity and halogen content of the epoxy compound tends to be large. Therefore, conventionally, when a compound having a low molecular weight alcoholic hydroxyl group is used, it is necessary to strictly control the amount of excess adduct formed. However, by using the production method of the present invention, a low molecular weight alcohol is used. Even when a compound is used, an epoxy compound having high purity and a low halogen content can be easily produced.

The epoxy compound obtained by the production method of the present invention can be applied to applications such as adhesives, paints, laminates, and sealants for electronic circuit boards.

<< Method for producing halohydrin ether compound >>
The method for producing a halohydrin ether compound of the present invention is characterized by comprising a step of carrying out an addition reaction between a compound having an alcoholic hydroxyl group and epihalohydrin using butyl tin trichloride as a catalyst. The addition reaction step can be carried out under the conditions described above for the method for producing an epoxy compound.

Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to the following examples. Hereinafter, "part" or "%" means "part by weight" or "% by weight", respectively, unless otherwise specified.

(Material used)
(1) Catalyst Butyl tin trichloride (manufactured by Tokyo Chemical Industry Co., Ltd.)
Boron trifluoride ether complex (manufactured by Tokyo Chemical Industry Co., Ltd.)
(2) Compound 2-ethylhexanol having an alcoholic hydroxyl group (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)
1,6-Hexanediol (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)
(3) Epichlorohydrin Epichlorohydrin (manufactured by Tokyo Chemical Industry Co., Ltd.)
(4) Solvent xylene (manufactured by Kishida Chemical Co., Ltd.)

(Example 1)
In a 300 ml separable flask equipped with a Dimroth condenser, a thermometer and a dropping funnel, 120.0 g (0.92 mol) of 2-ethylhexanol (2-EH) and 8.7 g (MBTC) of butyl tin trichloride (MBTC) were placed. 03 mol) was added, and the mixture was stirred and mixed so that the internal temperature was 30 to 40 ° C. 56.8 g (0.61 mol) of epichlorohydrin (ECH) was placed in the dropping funnel, and the dropping funnel was charged over 3 hours while appropriately heating and cooling so that the internal temperature could be maintained at 30 to 40 ° C. After the completion of the dropping of epichlorohydrin, the reaction was carried out at 30-40 ° C. for another 2 hours. After completion of the reaction, the reaction solution was analyzed by gas chromatography (GC). As a result, the conversion rate of ECH was 100%, and the selectivity of the target product was 94.6%.

(Example 2)
Experiments were carried out in the same manner as in Example 1 except that the butyl tin trichloride was changed to 3.47 g (0.01 mol), and GC analysis was performed. As a result, the conversion rate of ECH was 100%, and the selectivity of the target product was 94.9%.

Subsequently, the internal temperature was adjusted to 50 to 60 ° C., 54.2 g (0.65 mol) of a 48% caustic soda aqueous solution charged in the dropping funnel was added over 2 hours, and the reaction was carried out for another 2 hours after the addition was completed. After completion of the reaction, 200 g of tap water was added to the reaction solution, and the mixture was stirred for 10 minutes and then transferred to a separating funnel. After allowing the separating funnel to stand for 30 minutes, the organic layer in the upper layer was recovered. By the reaction of 2-ethylhexanol with ECH and caustic soda, the desired epoxy compound could be obtained as shown in the following reaction formula. When the recovered organic layer was analyzed by GC, the purity of the corresponding epoxy compound (2-ethylhexyl glycidyl ether) was 94.1%.

(Example 3)
As shown in FIG. 3, two diaphragm pumps (Pump A and Pump B), a 1/8 inch union tea type mixer, and a residence time unit (stainless steel tube, inner diameter 4.35 mm, length 16.5 m, volume). A flow reactor consisting of 245.2 ml) was prepared, and the residence time unit was immersed in an oil bath set at 120 ° C. In advance, prepare a mixture of 100 parts by weight of 2-ethylhexanol and 2.9 parts by weight of MBTC, and use the diaphragm pump Pump A to prepare a mixture of 2-ethylhexanol and MBTC from the diaphragm pump Pump B. Epichlorohydrin was pumped so that the residence time in the residence time unit was 30 minutes. At this time, the flow rate of Pump A was 6.15 ml / min, and the flow rate of Pump B was 2.03 ml / min. The flow (reaction liquid) of Pump A and Pump B for 1 hour from the start of pumping is discarded as the initial flow, and the flow of 1 hour to 1 hour and 30 minutes after the start of pumping is collected as the main flow for GC analysis. gone. As a result, the conversion rate of ECH was 100% and the target selectivity was 93.3%.

(Example 4)
600 mg (5.08 mmol) of 1,6-hexanediol and 176 mg (0.63 mmol) of MBTC were added to a φ24 screw cap test tube, and the mixture was heated with a dryer to dissolve it. Then, 1.16 g (12.5 mmol) of ECH was added dropwise (2.4 mg / s) into the system, and 30 minutes after the completion of the addition, GC analysis was performed. As a result, the conversion of 1,6-hexanediol was 100% and the target selectivity was 61.7%.

(Example 5)
As shown in FIG. 4, two plunger pumps (Pump A and Pump B), a Micromixer manufactured by MiChS Co., Ltd., a MiChS α type mixer (inner diameter 600 μm), and a residence time unit (stainless steel tube, inner diameter 1.0 mm). , 2,500 mm in length and 1.96 ml in volume) was prepared. The micromixer and residence time unit were immersed in a water bath set at 60 ° C. and heated. In advance, 29.8 parts by weight of MBTC was heated and mixed with 100 parts by weight of 1,6-hexanediol to prepare a mixed solution, and a mixed solution of 1,6-hexanediol and MBTC was prepared from a plunger pump Pump A. , Epichlorohydrin was sent from the plunger pump Pump B so that the residence time in the residence time unit was 30 minutes. At this time, the flow rate of Pump A was 27 μl / min, and the flow rate of Pump B was 38 μl / min. The flow (reaction liquid) of Pump A and Pump B for 1 hour from the start of pumping is discarded as the initial flow, and the flow of 1 hour to 1 hour and 30 minutes after the start of pumping is collected as the main flow for GC analysis. gone. As a result, the conversion rate of 1,6-hexanediol was 100% and the target selectivity was 72.7%.

(Comparative Example 1)
Except that 8.7 g (0.03 mol) of butyl tin trichloride (MBTC) was changed to 0.26 g (1.8 mmol) of boron trifluoride ether complex (BF3 ether complex) and reacted under the conditions shown in Table 2. As a result of performing the same operation as in Example 1 and performing GC analysis, the conversion rate of ECH was 100% and the selectivity of the target product was 87.6%.

(Comparative Example 2)
A residence time unit of a mixture of 100 parts by weight of 2-ethylhexanol and 2.9 parts by weight of MBTC as 0.73 parts by weight of the boron trifluoride ether complex with respect to 100 parts by weight of 2-ethylhexanol. The reaction was carried out in the same manner as in Example 3 except that the liquid was sent so that the residence time was 2 minutes and the reaction was carried out under the conditions shown in Table 2. At this time, the flow velocity of Pump A was 92.0 ml / min and the flow velocity of Pump B was 30.6 ml / min. As a result of mainstream GC analysis, the conversion rate of ECH was 100% and the selectivity of the target product was 86.5%.

(Comparative Example 3)
The reaction was carried out in the same manner as in Example 4 except that 176 mg (0.63 mmol) of MBTC was changed to 4.2 mg (0.03 mmol) of boron trifluoride ether complex and the reaction was carried out under the conditions shown in Table 2. As a result of GC analysis, the conversion rate of 1,6-hexanediol was 100% and the target selectivity was 47.9%.

The results of the examples are shown in Table 1, and the results of the comparative examples are shown in Table 2.

Compared with Comparative Examples 1 and 2, in Examples 1 to 3, the productivity of the target compound (2-ethylhexylchlorohydrin ether) was improved, and a 2-ethylhexanol molecule represented by the following formula (I) was obtained. By-products with two molecules of epichlorohydrin added were reduced.

Similarly, the productivity of the target compound was improved in Examples 4 to 5 as compared with Comparative Example 3, and three molecules of epichlorohydrin were added to one molecule of 1,6-hexanediol represented by the following formula (II). By-products have been reduced.

1 Liquid transfer pump 2 Mixer 3 Dwelling time unit 4 Back pressure regulator 5 Constant temperature bath (water bath, oven, etc.)

Claims (7)

A method for producing an epoxy compound, which comprises a step of performing an addition reaction between a compound having an alcoholic hydroxyl group and epihalohydrin using butyl tin trichloride as a catalyst. The method for producing an epoxy compound according to claim 1, wherein the addition reaction is carried out in the absence of a solvent. The method for producing an epoxy compound according to claim 1 or 2, wherein the alcoholic hydroxyl group is a primary hydroxyl group. The method for producing an epoxy compound according to any one of claims 1 to 3, wherein the epoxy equivalent of the epoxy compound is 300 or less. The method for producing an epoxy compound according to any one of claims 1 to 4, wherein the number average molecular weight of the epoxy compound is 1000 or less. Further, the present invention comprises a step of ring-closing the halohydrin ether compound obtained in the addition reaction step with an alkali.
The method for producing an epoxy compound according to any one of claims 1 to 5. A step of carrying out an addition reaction between a compound having an alcoholic hydroxyl group and epihalohydrin using butyl tin trichloride as a catalyst is included.
A method for producing a halohydrin ether compound.

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