JP3885249B2 - Purification method of glycidyl (meth) acrylate - Google Patents

Description

【００４１】

【００４２】

【００４３】
上記の表２の結果から明らかなように、本発明の実施例１〜１０の精製方法では、蒸留時の初留カツト分が約６重量％以下、ピツチ（蒸留残渣）が約１７重量％以下で、約７７重量％以上の高い収率が得られており、しかも、この製品（メタ）アクリル酸グリシジルにはエピクロルヒドリンがほとんど含まれておらず、塩素濃度は約３５０ｐｐｍ以下の低い値を示しており、９９重量％以上の高純度の（メタ）アクリル酸グリシジルが得られていることがわかる。これに対して、比較例１〜５の精製方法では、収率および純度ともに、本発明の実施例１〜１０の方法に比べて、大分劣つていることが明らかである。
【００４４】
【発明の効果】
以上のように、本発明の精製方法によれば、エピクロルヒドリンを反応原料として得られた粗（メタ）アクリル酸グリシジルから、エピクロルヒドリンおよび反応で副生した塩素化合物をほとんど含まない、したがつて、塩素濃度が低い、高純度の（メタ）アクリル酸グリシジルを高収率で得ることができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for purifying crude glycidyl (meth) acrylate obtained using epichlorohydrin as a reaction raw material.
[0002]
[Prior 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 because of its structural characteristics. For example, there are a wide variety of paints, adhesives, pressure-sensitive adhesives, fiber modifiers, dispersants, resist materials, and the like.
[0003]
In order to produce glycidyl (meth) acrylate, the first method is a method using (meth) acrylic acid and epichlorohydrin as reaction raw materials (Japanese Patent Publication No. 37-7454), and the second method is (meth) A method using an alkali metal salt of acrylic acid and epichlorohydrin as reaction raw materials (Japanese Patent Publication No. 45-28762), and a third method using methyl (meth) acrylate and glycidyl as reaction raw materials (Japanese Patent Publication No. 47) No. -38421) is known.
[0004]
Of these, the first and second methods using epichlorohydrin as a reaction raw material are known as the most versatile methods, but according to these methods, unreacted epichlorohydrin and chlorine compounds by-produced in the reaction are removed. Even if distillation is performed, several thousand ppm of epichlorohydrin and a chlorine compound produced as a by-product in the reaction are mixed in the obtained product. These contaminations cause problems such as health problems 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. .
[0005]
In order to overcome this problem, Japanese Patent Application Laid-Open No. 48-36117 discloses that a reaction is performed by adding epichlorohydrin to a saturated or unsaturated carboxylic acid in the presence of a quaternary ammonium salt, and then adding epichlorohydrin or alkylene oxide. In the second step, the epoxy exchange reaction is performed, and in the second step, the reaction solution is mixed with an alkali hydroxide or an alkaline earth metal hydroxide to remove the by-product epichlorohydrin, and again in the presence of a quaternary ammonium salt. A method of obtaining a high-purity glycidyl carboxylate in a high yield by performing a second epoxy exchange reaction by heating and then repeating the second step is disclosed.
[0006]
However, in this method, since a quaternary ammonium salt remains, a polymer is generated during distillation, resulting in poor workability. In addition, glycerin dimethacrylate, glycerin trimethacrylate and the like are produced. There is a problem that the distillation pitch increases. JP-A-48-72115 discloses a method for preventing polymerization by adding a sulfonate to crude glycidyl (meth) acrylate after the reaction. The removal of is not enough.
[0007]
Japanese Patent Application Laid-Open No. 4-187682 discloses a method of performing distillation after stripping with an oxygen-containing gas in the presence of a quaternary ammonium salt. However, in this method, since a quaternary ammonium salt is present during distillation, the generation of epichlorohydrin as a by-product during distillation cannot be suppressed, and when distillation is performed in the presence of a quaternary ammonium salt, There is a problem that the polymer is generated and the workability is deteriorated, and further, glycerin dimethacrylate, glycerin trimethacrylate and the like are produced in a large amount and distillation pitch is increased.
[0008]
[Problems to be solved by the invention]
In view of such problems of the prior art, the present invention contains almost no epichlorohydrin and a chlorine compound produced as a by-product in the reaction from crude glycidyl (meth) acrylate obtained using epichlorohydrin as a reaction raw material. It is an object of the present invention to provide a novel purification method capable of obtaining high-purity glycidyl (meth) acrylate with a low chlorine concentration and high yield.
[0009]
[Means for Solving the Problems]
As a result of intensive investigations to achieve the above object, the inventors of the present invention obtained a basic compound of an alkali metal or an alkaline earth metal with a crude compound of glycidyl (meth) acrylate obtained using epichlorohydrin as a reaction raw material. After adding quaternary onium salt and distilling off epichlorohydrin, adding sulfonic acid or sulfonate and filtering or washing with water, followed by distillation, epichlorohydrin and reaction in crude glycidyl (meth) acrylate As a result, it was found that the chlorine compound produced as a by-product was almost removed and high purity glycidyl (meth) acrylate having a low chlorine concentration was obtained in a high yield, and the present invention was completed.
[0010]
The present invention relates to crude glycidyl (meth) acrylate obtained by reacting (meth) acrylic acid or an alkali metal salt thereof and epichlorohydrin in the presence of a quaternary onium salt, with respect to the crude glycidyl (meth) acrylate. Add 0.1 to 20% by weight of an alkali metal or alkaline earth metal basic compound and 0.01 to 5% by weight of a quaternary onium salt to the crude glycidyl (meth) acrylate, and distill off epichlorohydrin. Next, 0.5 to 10-fold mol of sulfonic acid or sulfonate is added to the quaternary onium salt, followed by filtration or washing with water, followed by distillation. Purification of glycidyl (meth) acrylate It concerns the method.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
As crude glycidyl (meth) acrylate to be purified in the present invention, (1) (meth) acrylic acid and epichlorohydrin are reacted in the presence of a quaternary onium salt, and then alkali metal or alkaline earth metal. From the reaction mixture obtained by reacting with the basic compound, by-product salts are removed by filtration, washing with water, etc. (2) Alkali metal salt of (meth) acrylic acid and epichlorohydrin are quaternary onium salts A salt obtained as a by-product from the reaction mixture obtained by the reaction in the presence of water by filtration, washing with water, etc., and (3) epichlorohydrin from the crude glycidyl (meth) acrylate of (1) and (2) above. And (4) those obtained by distilling the crude (meth) acrylate glycidyl of (3) above.
[0012]
Examples of the alkali metal or alkaline earth metal basic compound used in the purification method of the present invention include alkali metal or alkaline earth metal hydroxides, oxides, carbonates, and phosphates. Examples thereof include sodium, potassium hydroxide, lithium hydroxide, magnesium hydroxide, calcium hydroxide, barium hydroxide, magnesium oxide, calcium oxide, sodium carbonate, calcium carbonate, sodium phosphate, and potassium phosphate. These basic compounds can be used as solids, powders or aqueous solutions.
[0013]
These basic compounds may be used alone or in combination of two or more. As a usage-amount, it is 0.1-20 weight% with respect to crude (meth) acrylic-acid acrylate, Preferably it is 0.5-10 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 decreases due to side reactions, but also from the economical viewpoint.
[0014]
As the quaternary onium salt used in the purification method of the present invention, tetramethylammonium chloride, tetraethylammonium chloride, tetrabutylammonium chloride, trimethylethylammonium chloride, trimethylbenzylammonium chloride, triethylmethylammonium chloride, triethylbenzylammonium chloride, Tetramethylammonium bromide, tetraethylammonium bromide, tetramethylammonium iodide, tetraethylammonium iodide, tetramethylphosphonium chloride, tetraethylphosphonium chloride, tetrabutylphosphonium chloride, trimethylethylphosphonium chloride, trimethylbenzylphosphonium chloride, trie Methyl phosphonium chloride, triethylbenzylammonium phosphonium chloride, tetramethyl phosphonium bromide, tetraethyl phosphonium bromide, tetramethyl phosphonium Yo - iodide, tetraethyl phosphonium Yo - iodide and the like.
[0015]
These quaternary onium salts may be used singly 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 is the yield reduced due to a side reaction, but it is not preferable from the viewpoint of economy.
[0016]
In the purification method of the present invention, first, the basic compound and the quaternary onium salt are added to the crude glycidyl (meth) acrylate in the above ratio, and the crude methidyl acrylate is contained in the crude (meth) acrylate. Epichlorohydrin is distilled off. At that time, azeotropic distillation with water is effective, and it is desirable to carry out the process 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 reduced pressure, and the amount of air blowing after considering whether the crude (meth) acrylate is (1) to (4). can do.
[0017]
In the present invention, after the above epichlorohydrin has been distilled off, sulfonic acid or sulfonate is further added, followed by stirring at 20 to 70 ° C. for 20 to 60 minutes, followed by filtration or washing with water. Filtration removes the salt produced | generated by reaction and the basic compound of an unreacted alkali metal or alkaline-earth metal by atmospheric pressure filtration, pressure reduction filtration, pressure filtration, etc. In the water washing, a salt generated by the reaction and an unreacted alkali metal or alkaline earth metal basic compound are dissolved in water, and the separated aqueous layer is removed.
[0018]
Examples of the sulfonic acid or sulfonate used herein include sulfonic acids such as methanesulfonic acid, laurylsulfonic acid, paratoluenesulfonic acid, dodecylbenzenesulfonic acid, benzenesulfonic acid, polyoxyethylene stearyl sulfate, and methane. Examples thereof include sulfonates such as sodium sulfonate, sodium lauryl sulfonate, sodium paratoluenesulfonate, sodium benzenesulfonate, and polyoxystearyl sulfate soda.
[0019]
These sulfonic acids or sulfonates may be used alone or in combination of two or more. As a usage-amount, it is 0.5-10 times mole with respect to a quaternary onium salt, Preferably it is 1-5 times mole. If the amount is less than 0.5 times mol, a polymer is formed and the yield tends to decrease. Even if it is used in excess of 10 times mol, the yield does not change, which is not preferable from the viewpoint of economy.
[0020]
In the present invention, by adding sulfonic acid or sulfonate in this way, filtering or washing with water and then distilling, high purity glycidyl (meth) acrylate with a low chlorine concentration can be obtained in high yield. Generally, the amount of epichlorohydrin is 0.002% by weight or less, the chlorine content is 1,000 ppm or less, preferably 500 ppm or less, and the purity is 99% by weight or more, although it varies depending on the type of crude (meth) acrylate glycidyl. It is possible to obtain glycidyl (meth) acrylate in a high yield of 75% by weight or more, preferably around 80% by weight.
[0021]
【Example】
The present invention will be specifically described below with reference to examples and comparative examples. In addition, the crude glycidyl acrylates A to E used in Examples and Comparative Examples are obtained by the following preparation methods 1 to 5.
[0022]
<Preparation method 1>
Methacrylic acid and epichlorohydrin (6 moles of methacrylic acid) were charged into a flask equipped with a stirrer, thermometer and reflux condenser. Subsequently, tetramethylammonium chloride (based on 3 mol% of methacrylic acid) and phenothiazine (0.02 wt% of the total charged amount) were added and kept at 90 ° C. for 5 hours. Next, a 50 wt% aqueous sodium hydroxide solution (1 mole of methacrylic acid) was added dropwise over 6 hours while blowing air at 90 ° C. and 200 mmHg. After completion of the dropwise addition, the mixture was washed with water (50% by weight of the total amount charged) to obtain crude glycidyl methacrylate A.
[0023]
<Preparation method 2>
Unreacted epichlorohydrin was reduced in pressure over 6 hours while blowing air and water (relative to crude glycidyl methacrylate A 5% by weight / hour) at 60 ° C. and 50 mmHg to the crude glycidyl methacrylate A obtained in Preparation Method 1. By distillation, crude glycidyl methacrylate B was obtained.
[0024]
<Preparation method 3>
Unreacted epichlorohydrin was distilled off under reduced pressure for 12 hours while blowing air and 50 ml / hour of water at 60 ° C. and 50 mmHg into the crude glycidyl methacrylate A (1,062 g) obtained in Preparation Method 1. Then, crude glycidyl methacrylate C was obtained by performing distillation.
[0025]
<Preparation method 4>
Sodium methacrylate was synthesized by a neutralization reaction of 430.5 g (5 mol) of methacrylic acid and 200 g (5 mol) of sodium hydroxide, and this was dehydrated. 540.5 g of sodium methacrylate and epichlorohydrin 2,775. 9 g (30 mol) was charged into a flask equipped with a stirrer, thermometer and reflux condenser. Next, 24.0 g of triethylbenzylammonium chloride (2 mol% of sodium methacrylate) and 0.55 g of phenothiazine were added, and the reaction was carried out for 5 hours while blowing air at 90 ° C. and 200 mmHg. After the completion of the reaction, after washing with 1,500 g of water, 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 to obtain crude methacrylic acid. Glycidyl D was obtained.
[0026]
<Preparation method 5>
By the same method as Preparation Method 1, 360.2 g (5 mol) of acrylic acid, 2,775.9 g (30 mol) of epichlorohydrin, 65.6 g (0.20 mol, 4 mol to methacrylic acid) of tributylbenzylphosphonium chloride %), 0.55 g of phenothiazine, and 480 g (6 mol) of 50% by weight sodium hydroxide gave crude glycidyl acrylate E.
[0027]
Example 1
To 2,933 g of crude glycidyl methacrylate A, 29.3 g of sodium hydroxide (vs. crude glycidyl methacrylate A 1.0% by weight) and 1.5 g of tetramethylammonium chloride (vs. crude glycidyl methacrylate A 0.05% by weight) were added. Unreacted epichlorohydrin was distilled off under reduced pressure for 12 hours while blowing air and 50 ml / hour of water at 60 ° C. and 50 mmHg. Next, 4.7 g of paratoluenesulfonic acid (2 moles of tetramethylammonium chloride) was added, stirred at 60 ° C. for 20 minutes, washed with 150 g of water, dehydrated under reduced pressure, and filtered. Finally, distillation was performed to obtain purified glycidyl methacrylate.
[0028]
Example 2
To 766 g of crude glycidyl methacrylate B, 38.3 g of sodium hydroxide (vs. 5% by weight of crude glycidyl methacrylate B) and 3.8 g of tetramethylammonium chloride (vs. 0.5% by weight of crude glycidyl methacrylate B) were added. Unreacted epichlorohydrin was distilled off under reduced pressure for 6 hours while blowing air and 50 ml / hour of water at 50 mmHg. Next, 7.6 g of para-toluenesulfonic acid (2 mol of tetramethylammonium chloride) was added, stirred for 30 minutes at 40 ° C., dehydrated under reduced pressure, and then filtered. Finally, distillation was performed to obtain purified glycidyl methacrylate.
[0029]
Examples 3-7
The same method as in Example 2 using the alkali metal or alkaline earth metal basic compound, quaternary onium salt and sulfonic acid or sulfonate salt shown in Table 1 below for the crude glycidyl methacrylate B To obtain purified glycidyl methacrylate. In addition to Examples 3-7, 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.
[0030]
Each code | symbol in Table 1 is as follows.
50% NaOH: 50% by weight sodium hydroxide aqueous solution TMAC: tetramethylammonium chloride TEBzAC: triethylbenzylammonium chloride TBuBzPC: tributylbenzylphosphonium chloride PTS: paratoluenesulfonic acid PTSNa: paratoluenesulfonic acid sodium
Example 8
To 530.3 g of crude glycidyl methacrylate C, sodium hydroxide and triethylbenzeneammonium chloride listed in Table 1 were added, and air and 50 ml / hour of water were blown at 60 ° C. and 50 mmHg, and unreacted over 3 hours. Epichlorohydrin was distilled off under reduced pressure. Next, sodium paratoluenesulfonate was added, and the mixture was stirred at 20 ° C. for 60 minutes, washed with 220 g of water, dehydrated under reduced pressure, and filtered. Finally, distillation was performed to obtain purified glycidyl methacrylate.
[0032]
Example 9
Sodium hydroxide and tetramethylammonium chloride listed 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. Next, p-toluenesulfonic acid was added, stirred at 70 ° C. for 20 minutes, dehydrated under reduced pressure, and then filtered. Finally, distillation was performed to obtain purified glycidyl methacrylate.
[0033]
Example 10
Epichlorohydrin was distilled off under reduced pressure in the same manner as in Example 1 by adding 50 wt% aqueous sodium hydroxide solution and tetramethylammonium chloride shown in Table 1 to 2,864 g of crude glycidyl acrylate E. Subsequently, sodium paratoluenesulfonate was added, stirred at 40 ° C. for 60 minutes, dehydrated under reduced pressure, and then filtered. Finally, distillation was performed to obtain purified glycidyl methacrylate.
[0034]
Comparative Example 1
Unreacted epichlorohydrin was distilled off under reduced pressure for 6 hours while blowing air and 50 ml / hour of water at 60 ° C. to 766 g of crude glycidyl methacrylate B. Subsequently, after dehydrating under reduced pressure, it filtered. Finally, distillation was performed to obtain purified glycidyl methacrylate.
[0035]
Comparative Example 2
Sodium hydroxide described in Table 1 was added to 766 g of crude glycidyl methacrylate B, and 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. After dehydration under reduced pressure, the mixture was filtered. Finally, distillation was performed to obtain purified glycidyl methacrylate.
[0036]
Comparative Example 3
The tributylbenzylphosphonium chloride described in Table 1 was added to 766 g of crude glycidyl methacrylate B, and 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. Subsequently, after dehydrating under reduced pressure, it filtered. Finally, purified glycidyl methacrylate was obtained by distillation.
[0037]
Comparative Example 4
While blowing air and 50 ml / hour of water at 60 ° C. and 50 mmHg into crude glycidyl methacrylate B 766 g, paratoluenesulfonic acid shown in Table 1 was added, and unreacted epichlorohydrin was distilled off under reduced pressure for 6 hours. Finally, distillation was performed to obtain purified glycidyl methacrylate.
[0038]
Comparative Example 5
To 766 g of crude glycidyl methacrylate, sodium hydroxide and tributylbenzylphosphonium chloride shown in Table 1 were added, and unreacted epichlorohydrin was added over 6 hours while blowing air and 50 ml / hour of water at 60 ° C. and 50 mmHg. Distilled under reduced pressure. Subsequently, after dehydrating under reduced pressure, it filtered. Finally, distillation was performed to obtain purified glycidyl methacrylate.
[0039]
About the refined glycidyl (meth) acrylate obtained in the above Examples 1 to 10 and Comparative Examples 1 to 5, the yield, the amount of the first cut at the time of distillation and the yield of the pit (distillation residue) are described below. It is shown in Table 2. Further, the purity of purified glycidyl (meth) acrylate, the concentration of epichlorohydrin and the chlorine concentration were examined and are shown in Table 2. Purity and epichlorohydrin concentration were measured by the following gas chromatographic analysis, and chlorine concentration was measured by a method of titration with silver nitrate after treatment with an alkaline aqueous solution. In Table 2, “ND” in the column of epichlorohydrin concentration indicates that it could not be detected by the above analysis (it was 0.002% by weight or less).
[0040]

[0041]

[0042]

[0043]
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 is about 6% by weight or less, and the pitch (distillation residue) is about 17% by weight or less. In addition, a high yield of about 77% by weight or more was obtained, and this product (meth) acrylate glycidyl contained almost no epichlorohydrin, and the chlorine concentration showed a low value of about 350 ppm or less. It can be seen that 99% by weight or more of high purity glycidyl (meth) acrylate was obtained. On the other hand, it is clear that the purification methods of Comparative Examples 1 to 5 are far inferior in both yield and purity as compared with the methods of Examples 1 to 10 of the present invention.
[0044]
【The invention's effect】
As described above, according to the purification method of the present invention, the crude (meth) acrylate glycidyl obtained using epichlorohydrin as a reaction raw material contains almost no epichlorohydrin and a chlorine compound produced as a by-product in the reaction. High purity glycidyl (meth) acrylate with low concentration can be obtained in high yield.

Claims (1)

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