JPH09249657A - Purification of glycidyl (meth)acrilate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To purify a highly purified glycidyl (meth)acrylate slightly containing epichlorohydrin and a by-produced chlorine compound, therefore having low chlorine concentration at a high yield, from a crude glycidyl (meth)acrylate obtained by using epichlorohydrin as a reactive raw material. SOLUTION: To obtain the objective purified glycidyl (meth)acrylate, a (meth) acrylic acid or its alkali metal salt is reacted with epichlorohydrin in the presence of a quaternary onium salt and the resultant crude glycidyl (meth)acrylate is added with a basic compound of an alkaline metal or an alkaline earth metal in an amount of 0.1-20wt.% and a quaternary onium salt in an amount of 0.01-5wt.%, respectively based on the crude glycidyl (meth)acrylate, then the epichlorohydrin is distilled out. Thus, a sulfonic acid or a sulfonate in an amount of 0.5-10 times mol based on the quaternary onium salt is added, filtrated or washed, and further distilled.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for purifying crude glycidyl (meth) acrylate obtained by using epichlorohydrin as a reaction raw material.

[0002]

2. Description of the Related Art Glycidyl (meth) acrylate having a polymerizable acryloyl group or methacryloyl group and an epoxy group in one molecule is widely used as a reactive monomer due to its structural characteristics. For example, it is widely used in paints, adhesives, pressure sensitive adhesives, fiber modifiers, dispersants, resist materials, and the like.

The first method for producing glycidyl (meth) acrylate is to use (meth) acrylic acid and epichlorohydrin as reaction raw materials (Japanese Patent Publication No. 37-74).
54), the second method is to use an alkali metal salt of (meth) acrylic acid and epichlorohydrin as reaction raw materials (Japanese Patent Publication No. 45-28762), and the third method is methyl (meth) acrylate. And glycidyl as reaction raw materials (JP-B-47-38421)
It has been known.

Of these, the first and second methods using epichlorohydrin as a reaction raw material are known as the most general-purpose methods. According to these methods, unreacted epichlorohydrin and chlorine compounds by-produced in the reaction are used. Even if distillation is carried out for removal, several thousand ppm of epichlorohydrin and several% of chlorine compounds by-produced in the reaction are mixed in the obtained product. These contaminations cause problems such as health hazards for workers, catalyst poisons for group transfer polymerization, and corrosion of metals when used in the electronic and electrical fields, limiting the industrial use of products. .

In order to overcome this problem, Japanese Patent Laid-Open No. 48-3
6117, in the presence of a quaternary ammonium salt,
Epichlorohydrin is added to saturated or unsaturated carboxylic acid to react, and epichlorohydrin or alkylene oxide is further added to carry out the epoxy exchange reaction in the first step. In the second step, the reaction solution is treated with alkali hydroxide or alkaline earth metal hydroxide. By mixing with a substance, the by-produced epichlorohydrin is ring-closed and removed, and the mixture is heated and reacted again in the presence of a quaternary ammonium salt to carry out a second epoxy exchange reaction, and by further repeating the second step,
A method for obtaining high-purity glycidyl carboxylate in high yield is disclosed.

However, in this method, since the quaternary ammonium salt remains, a polymerized product is generated during distillation and workability is deteriorated, and moreover, glycerin dimethacrylate,
Glycerin trimethacrylate and the like are generated, and there is a problem that distillation pitch increases. In addition, JP-A-48-7
Japanese Patent No. 2115 discloses a method in which a sulfonate is added to crude glycidyl (meth) acrylate after the reaction to prevent polymerization, but removal of chlorine compounds by-produced in the reaction is not sufficient.

Japanese Unexamined Patent Publication No. 4-187682 discloses a fourth method.
A method of stripping with an oxygen-containing gas in the presence of a primary ammonium salt and then performing distillation is disclosed. However, in this method, since the quaternary ammonium salt is present during the distillation, it is not possible to suppress the generation of epichlorohydrin, which is a by-product during the distillation, and when the distillation is performed in the presence of the quaternary ammonium salt, There is a problem that the workability is deteriorated due to the generation of a polymer, and more glycerin dimethacrylate, glycerin trimethacrylate and the like are produced, and the distillation pitch increases.

[0008]

DISCLOSURE OF THE INVENTION In view of the above problems of the prior art, the present invention provides epichlorohydrin and a chlorine compound by-produced in the reaction from crude glycidyl (meth) acrylate obtained using epichlorohydrin as a reaction raw material. It contains almost no chlorine and therefore has a low chlorine concentration,
It is an object of the present invention to provide a novel purification method by which highly purified glycidyl (meth) acrylate can be obtained in good yield.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in order to achieve the above object, and as a result, as a result of using crude glycidyl (meth) acrylate obtained using epichlorohydrin as a reaction raw material, alkali metal or alkali After adding a basic compound of an earth metal and a quaternary onium salt and distilling off epichlorohydrin, further adding a sulfonic acid or a sulfonate and filtering or washing with water, followed by distillation, a crude (meta) is obtained. ) It was found that epichlorohydrin in glycidyl acrylate and chlorine compounds by-produced in the reaction were almost removed, and high-purity glycidyl (meth) acrylate having a low chlorine concentration was obtained in high yield.
The present invention has been completed.

The present invention relates to a crude glycidyl (meth) acrylate obtained by reacting (meth) acrylic acid or an alkali metal salt thereof with epichlorohydrin in the presence of a quaternary onium salt. 0.1 to 20% by weight of a basic compound of an alkali metal or alkaline earth metal with respect to glycidyl and 0.01 to 5% by weight of a quaternary onium salt with respect to crude glycidyl (meth) acrylate are added to form epichlorohydrin. Is distilled off, and then 0.5 to 10 times mol of sulfonic acid or sulfonate is added to the quaternary onium salt, followed by filtration or washing with water, and further performing distillation (meth) acrylic acid. The present invention relates to a method for purifying glycidyl.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION As crude glycidyl acrylate to be purified in the present invention, (1) (meth) acrylic acid and epichlorohydrin are reacted in the presence of a quaternary onium salt, A reaction mixture obtained by reacting with a basic compound of an alkali metal or an alkaline earth metal, from which a by-product salt is removed by filtration, washing with water, etc. (2) An alkali metal salt of (meth) acrylic acid A reaction mixture obtained by reacting epichlorohydrin in the presence of a quaternary onium salt, and removing a salt produced as a by-product by filtration, washing with water, or the like, (3) The crude (1) or (2) above. Examples thereof include those obtained by removing epichlorohydrin from glycidyl (meth) acrylate and (4) those obtained by distilling crude glycidyl (meth) acrylate of (3) above.

The alkali metal or alkaline earth metal basic compound used in the purification method of the present invention includes alkali metal or alkaline earth metal hydroxides, oxides, carbonates or phosphates. , Sodium hydroxide, potassium hydroxide, lithium hydroxide, magnesium hydroxide, calcium hydroxide, barium hydroxide, magnesium oxide, calcium oxide, sodium carbonate, calcium carbonate, sodium phosphate, potassium phosphate and the like. These basic compounds can be used as solids, powders or aqueous solutions.

These basic compounds may be used alone or in combination of two or more. The amount of use is 0. 1 with respect to the crude glycidyl (meth) acrylate.
It is 1 to 20% by weight, preferably 0.5 to 10% by weight. If it is less than 0.1% by weight, the effect of lowering the chlorine concentration is small, and if it exceeds 20% by weight, not only the yield is lowered due to a side reaction, but it is also not economically preferable.

Examples of the quaternary onium salt used in the purification method of the present invention include tetramethylammonium chloride, tetraethylammonium chloride, tetrabutylammonium chloride, trimethylethylammonium chloride, trimethylbenzylammonium chloride, triethylmethylammonium chloride and triethylbenzyl. Ammonium chloride, tetramethylammonium bromide, tetraethylammonium bromide, tetramethylammonium iodide, tetraethylammonium iodide, tetramethylphosphonium chloride, tetraethylphosphonium chloride, tetrabutylphosphonium chloride, trimethylethylphosphonium chloride, trimethylbenzylphosphonium chloride De, triethyl methyl phosphonium chloride, triethylbenzylammonium phosphonium chloride, tetramethyl phosphonium bromide, tetraethyl phosphonium bromide, tetramethyl phosphonium Yo - iodide, tetraethyl phosphonium Yo - iodide and the like.

These quaternary onium salts may be used alone or in combination of two or more. The amount used is 0.01 to 5% by weight, preferably 0.05 to 1% by weight, based on the crude glycidyl (meth) acrylate. If it is less than 0.01% by weight, the effect of lowering the chlorine concentration is small, and if it exceeds 5% by weight, not only the yield is lowered due to a side reaction, but it is also not economically preferable.

In the purification method of the present invention, first, the above-mentioned basic compound and quaternary onium salt are added to the above-mentioned crude glycidyl (meth) acrylate in the above-mentioned proportions to prepare the crude glycidyl (meth) acrylate. The epichlorohydrin contained in is distilled off. At that time, azeotropic distillation with water is effective, and it is desirable to carry out while introducing air for the purpose of inhibiting polymerization. The treatment time is appropriately set according to the treatment conditions such as the treatment temperature, the degree of pressure reduction, and the amount of air blown in consideration of which of the above (1) to (4) the crude (meth) acrylate glycidyl is. can do.

In the present invention, after the above-mentioned epichlorohydrin is distilled off, sulfonic acid or sulfonate is further added, and the mixture is usually stirred at 20 to 70 ° C. for 20 to 60 minutes and then filtered or washed with water. The filtration removes the salt produced by the reaction and the unreacted basic compound of alkali metal or alkaline earth metal by atmospheric filtration, reduced pressure filtration, pressure filtration or the like. Also, washing with water
The salt produced by the reaction and the unreacted basic compound of alkali metal or alkaline earth metal are dissolved in water to remove the separated aqueous layer.

Examples of the sulfonic acid or sulfonate used here include methanesulfonic acid, laurylsulfonic acid, paratoluenesulfonic acid, dodecylbenzenesulfonic acid, benzenesulfonic acid, polyoxyethylene stearyl sulfate, and the like. And sulfonates such as sodium methanesulfonate, sodium laurylsulfonate, sodium paratoluenesulfonate, sodium benzenesulfonate, and polyoxystearyl sulphate soda.

These sulfonic acids or sulfonates may be used alone or in combination of two or more. The amount used is based on the quaternary onium salt,
The amount is 0.5 to 10 times mol, preferably 1 to 5 times mol.
If it is less than 0.5 times by mole, a polymer is likely to be generated and the yield tends to be lowered. Even if it is used in excess of 10 times by mole, the yield does not change, which is not preferable from the economical aspect.

According to the present invention, high purity glycidyl (meth) acrylate having a low chlorine concentration can be obtained in a high yield by adding sulfonic acid or sulfonic acid salt, filtering or washing with water and then distilling. You can Depending on the type of crude (meth) acrylic acid glycidyl,
Generally, the amount of epichlorohydrin is 0.002% by weight or less and the chlorine content is 1,000 ppm or less, preferably 50%.
It can be suppressed to 0 ppm or less, and glycidyl (meth) acrylate having a purity of 99% by weight or more can be obtained in a high yield of 75% by weight or more, preferably around 80% by weight.

[0021]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples. The crude glycidyl (meth) acrylates A to E used in Examples and Comparative Examples were obtained by the following preparation methods 1 to 5.

<Preparation Method 1> Methacrylic acid and epichlorohydrin (6 times mol of methacrylic acid) were placed in a flask equipped with a stirrer, a thermometer, and a reflux condenser. Then
Tetramethylammonium chloride (based on methacrylic acid 3 mol%) and phenothiazine (0.02 wt% of the total amount charged) were added, and the mixture was kept at 90 ° C for 5 hours. Next, 90 ℃,
While blowing air at 200 mmHg, a 50 wt% sodium hydroxide aqueous solution (to 1-fold mol of methacrylic acid) was added dropwise over 6 hours. After the dropping, water (50% of the total amount charged)
It was washed with water to obtain crude glycidyl methacrylate A.

<Preparation Method 2> The crude glycidyl methacrylate A obtained in Preparation Method 1 was blown with air and water (vs. crude glycidyl methacrylate A 5% by weight / hour) at 60 ° C. and 50 mmHg for 6 hours. Unreacted epichlorohydrin was distilled off under reduced pressure to obtain crude glycidyl methacrylate B.

<Preparation Method 3> The crude glycidyl methacrylate A (1,062 g) obtained in Preparation Method 1 was treated at 60 ° C.
While blowing air and 50 ml / hour of water at 50 mmHg,
Unreacted epichlorohydrin was distilled off under reduced pressure for 12 hours, and then distilled to obtain crude glycidyl methacrylate C.

<Preparation Method 4> Methacrylic acid 430.5 g
(5 mol) and 200 g (5 mol) of sodium hydroxide were neutralized to synthesize sodium methacrylate, which was dehydrated to give 540.5 g of sodium methacrylate and epichlorohydrin 2,775.9 g (30 mol). Was charged into a flask equipped with a stirrer, a thermometer, and a reflux condenser. Then, 24.0 g of triethylbenzylammonium chloride (based on sodium methacrylate 2 mol%),
Add 0.55g of phenothiazine, 90 ℃, 200mm
The mixture was reacted for 5 hours while blowing air with Hg. After completion of the reaction, wash with 1,500 g of water and then 60 ℃, 50 mm
Crude glycidyl methacrylate D was obtained by distilling off unreacted epichlorohydrin under reduced pressure for 6 hours while blowing air and 50 ml / hour of water with Hg.

<Preparation Method 5> By the same method as in Preparation Method 1, 360.2 g (5 mol) of acrylic acid, 2,775.9 g (30 mol) of epichlorohydrin, and 65.6 g (0.20 mol of tributylbenzylphosphonium chloride). , Methacrylic acid (4 mol%), phenothiazine 0.55 g, 50% by weight sodium hydroxide 480 g (6
Mol) was used to obtain crude glycidyl acrylate E.

Example 1 2,933 g of crude glycidyl methacrylate A was added to 29.3 g of sodium hydroxide (vs. crude glycidyl methacrylate A).
1.0% by weight) and 1.5 g of tetramethylammonium chloride (0.05% by weight of crude glycidyl methacrylate A) were added, and the mixture was blown with air and 50 ml / hour of water at 60 ° C. and 50 mmHg for 12 hours. Then, unreacted epichlorohydrin was distilled off under reduced pressure. Then, 4.7 g of paratoluenesulfonic acid (2 times mol of tetramethylammonium chloride) was added, and the mixture was stirred at 60 ° C. for 20 minutes, washed with 150 g of water, dehydrated under reduced pressure, and then filtered. Finally, distillation was performed to obtain purified glycidyl methacrylate.

Example 2 To 766 g of crude glycidyl methacrylate B was added 38.3 g of sodium hydroxide (5% by weight of crude glycidyl methacrylate B) and 3.8 g of tetramethylammonium chloride.
(0.5% by weight of crude glycidyl methacrylate B) was added, and unreacted epichlorohydrin was distilled off under reduced pressure over 6 hours while blowing air and 50 ml / hour of water at 60 ° C. and 50 mmHg. Then, 7.6 g of paratoluenesulfonic acid (2 times mol of tetramethylammonium chloride) was added, and the mixture was stirred at 40 ° C. for 30 minutes, dehydrated under reduced pressure, and then filtered. Finally, distillation was performed to obtain purified glycidyl methacrylate.

Examples 3 to 7 Using a basic compound of an alkali metal or an alkaline earth metal, a quaternary onium salt, and a sulfonic acid or a sulfonate as shown in Table 1 below, with respect to the crude glycidyl methacrylate B. Purification treatment was performed in the same manner as in Example 2 to obtain purified glycidyl methacrylate. In addition to the present Examples 3 to 7, Table 1 also shows the types and amounts of the above-mentioned compounds used in Examples 1 and 2 and Examples 8 to 10 and Comparative Examples 1 to 5 described later. Was also written.

The symbols in Table 1 are as follows. 50% NaOH: 50% by weight aqueous sodium hydroxide solution TMAC: Tetramethylammonium chloride TEBzAC: Triethylbenzylammonium chloride TBuBzPC: Tributylbenzylphosphonium chloride PTS: Paratoluenesulfonic acid PTSNa: Sodium paratoluenesulfonate

Example 8 To 530.3 g of crude glycidyl methacrylate C, sodium hydroxide and triethylbenzene ammonium chloride shown in Table 1 were added, and the mixture was mixed with air at 60 ° C. and 50 mmHg and 50%.
Unreacted epichlorohydrin was distilled off under reduced pressure over 3 hours while blowing water at a rate of ml / hour. Then add sodium paratoluene sulfonate and add 60 at 20 ° C.
After stirring for a minute, the mixture was washed with 220 g of water, dehydrated under reduced pressure, and filtered. Finally, distillation was performed to obtain purified glycidyl methacrylate.

Example 9 Sodium hydroxide and tetramethylammonium chloride described in Table 1 were added to 748 g of crude glycidyl methacrylate D, and epichlorohydrin was distilled off under reduced pressure in the same manner as in Example 2. Then, paratoluenesulfonic acid was added, and the mixture was stirred at 70 ° C. for 20 minutes, dehydrated under reduced pressure, and then filtered. Finally, distillation was performed to obtain purified glycidyl methacrylate.

Example 10 To 2,864 g of crude glycidyl acrylate E was added 50% by weight aqueous sodium hydroxide solution and tetramethylammonium chloride shown in Table 1, and epichlorohydrin was distilled off under reduced pressure in the same manner as in Example 1. . Then add sodium paratoluenesulfonate and add 6 at 40 ° C.
After stirring for 0 minutes, the mixture was dehydrated under reduced pressure and then filtered. Finally, distillation was performed to obtain purified glycidyl methacrylate.

Comparative Example 1 766 g of crude glycidyl methacrylate B was added at 60 ° C. to 5
While blowing air and 50 ml / hour of water at 0 mmHg, 6
Unreacted epichlorohydrin was distilled off under reduced pressure over time. Then, it was dehydrated under reduced pressure and then filtered. Finally, distillation was performed to obtain purified glycidyl methacrylate.

Comparative Example 2 To 766 g of crude glycidyl methacrylate B was added the sodium hydroxide shown in Table 1, and air and 50 ml / hour of water were blown at 60 ° C. and 50 mmHg for 6 hours while unreacted epichlorohydrin was added. Was distilled off under reduced pressure. After dehydration under reduced pressure, it was filtered. Finally, distillation was performed to obtain purified glycidyl methacrylate.

Comparative Example 3 To 766 g of crude glycidyl methacrylate B was added tributylbenzylphosphonium chloride shown in Table 1,
Unreacted epichlorohydrin was distilled off under reduced pressure for 6 hours while blowing air and 50 ml / hour of water at 60 ° C. and 50 mmHg. Then, it was dehydrated under reduced pressure and then filtered. Finally, distillation was performed to obtain purified glycidyl methacrylate.

Comparative Example 4 766 g of crude glycidyl methacrylate B was added at 60 ° C. and 50
While blowing air and 50 ml / hour of water with mmHg,
Paratoluenesulfonic acid described in 1) was added, and unreacted epichlorohydrin was distilled off under reduced pressure for 6 hours. Finally, distillation was performed to obtain purified glycidyl methacrylate.

Comparative Example 5 Sodium hydroxide and tributylbenzylphosphonium chloride shown in Table 1 were added to 766 g of crude glycidyl methacrylate B, and 50 ml / air of air was added at 60 ° C. and 50 mmHg.
The unreacted epichlorohydrin was distilled off under reduced pressure over 6 hours while blowing water for a period of time. Then, it was dehydrated under reduced pressure and then filtered. Finally, distillation was performed to obtain purified glycidyl methacrylate.

The above Examples 1 to 10 and Comparative Examples 1 to 5
The yields of the purified (meth) acrylic acid glycidyl obtained in 1. and the yields of the initial cut fraction and the pitch (distillation residue) at the time of distillation are shown in Table 2 below. Further, the purity of purified glycidyl (meth) acrylate, the concentration of epichlorohydrin and the concentration of chlorine were examined, and shown in Table 2. The purity and the concentration of epichlorohydrin were measured by the following gas chromatography analysis, and the chlorine concentration was measured by a method of treating with an alkaline aqueous solution and then titrating with silver nitrate. In Table 2, "ND" in the column of the concentration of epichlorohydrin could not be detected by the above analysis (it was 0.002% by weight or less).
It is shown that.

<Gas Chromatography-Analysis> Model: “GC14-A” manufactured by Shimadzu Corporation Measurement conditions: column; PEG-HT 5%, inner diameter 3 mm, length 2 m Injection temperature; 280 ° C. Column temperature; 80- 260 ° C, temperature rising rate of 7.5 ° C / min

[0041] (Note) * 1: To crude glycidyl acrylate (unit: wt%) * 2: To crude glycidyl acrylate (unit: wt%) * 3: To quaternary onium salt (unit: double) Mol)

[0042] (Note) * 4, 5: Yield is the percentage obtained by dividing the weight by the weight before distillation. * 6: Yield is the percentage obtained by dividing the weight by the weight before distillation. The ECH concentration is the percentage of epichlorohydrin in the product. Concentration, chlorine concentration is the concentration of chlorine in the product

As is clear from the results of Table 2 above, in the purification methods of Examples 1 to 10 of the present invention, the initial cut content during distillation was about 6% by weight or less, and the pitch (distillation residue) was about 17%.
A high yield of about 77% by weight or less was obtained at a weight% or less, and moreover, this product glycidyl (meth) acrylate contained almost no epichlorohydrin, and the chlorine concentration was a low value of about 350 ppm or less. Shows 9
It can be seen that 9% by weight or more of high-purity glycidyl (meth) acrylate was obtained. On the other hand, Comparative Example 1
It is apparent that the purification methods of ~ 5 are much inferior to the methods of Examples 1 to 10 of the present invention in yield and purity.

[0044]

As described above, according to the purification method of the present invention, from crude glycidyl (meth) acrylate obtained using epichlorohydrin as a reaction raw material, epichlorohydrin and chlorine compounds by-produced in the reaction are scarcely contained. Therefore, highly pure glycidyl (meth) acrylate having a low chlorine concentration can be obtained in a high yield.

Claims (1)

[Claims] 1. A crude glycidyl (meth) acrylate obtained by reacting (meth) acrylic acid or an alkali metal salt thereof with epichlorohydrin in the presence of a quaternary onium salt to give a crude glycidyl (meth) acrylate. To 0.1
0.01 to 5% by weight of a quaternary onium salt is added to 20% by weight of a basic compound of an alkali metal or an alkaline earth metal and crude glycidyl (meth) acrylate, and epichlorohydrin is distilled off. A method for purifying glycidyl (meth) acrylate, which comprises adding 0.5 to 10 moles of a sulfonic acid or a sulfonate to a quaternary onium salt, filtering or washing with water, and further performing distillation.