JPS6312463B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing diacrylate or dimethacrylate, and more specifically, 2,2-bis(4
-Hydroxypolyoxyalkylene phenyl)propane and acrylic acid or methacrylic acid are subjected to an esterification reaction, and the resulting diacrylate or dimethacrylate is easily recovered in good yield. Conventionally, the synthesis of diacrylates or dimethacrylates of 2,2-bis(4-hydroxypolyoxyalkylenephenyl)propanes has generally been carried out for 2,2-bis(4-hydroxypolyoxyalkylenephenyl)propanes. Excess acrylic acid or methacrylic acid is subjected to an esterification reaction in an organic solvent in the presence of a sulfonic acid having an aromatic ring. Therefore, since the diacrylate or diacrylate (hereinafter also simply referred to as diacrylate or dimethacrylate) of 2,2-bis(4-hydroxypolyoxyalkylene phenyl)propanes has polymerizability, the above ester It is also necessary to suppress the polymerization of diacrylate or dimethacrylate produced in the chemical reaction.
For this reason, a polymerization inhibitor such as cuprous chloride is generally added to the reaction system, but by using an excess of a sulfonic acid catalyst having an aromatic ring, the heating reaction time can be shortened and the formation of Polymerization of diacrylate or dimethacrylate is suppressed. Therefore, it is necessary to wash the reaction solution after the esterification reaction with an alkaline aqueous solution or the like in order to neutralize and remove the terminally reacted acrylic acid or methacrylic acid and the excess aromatic ring-containing sulfonic acid. However, since such a reaction solution exhibits an emulsion state during the alkaline washing treatment, it is extremely difficult to separate the organic solvent and the alkaline aqueous solution after the treatment. That is, not only does it take a long time for the phase separation between the organic solvent and the alkaline aqueous solution after the reaction, but also the yield decreases because the produced diacrylate or dimethacrylate is hydrolyzed by prolonged contact with the alkali. This results in In addition, water is mixed into the organic solvent after separation due to the emulsion state during alkali washing, so
Not only does the dehydration process require a large amount of dehydrating agent, but also hydrolysis occurs when heated during solvent removal. The reason why the reaction solution as described above exhibits an emulsion state due to alkali neutralization is not clear, but the resulting reaction solution has a high viscosity and is particularly useful for neutralized sulfonic acids having aromatic rings used as catalysts (e.g.

The present inventors speculated that this may be due to the formation of [Formula], etc.), which acts as a surfactant. Therefore, as a result of further intensive research based on this assumption, the present inventors have found that diacrylate or dimethacrylate can be successfully recovered by removing the sulfonic acid having an aromatic ring from the reaction solution in advance. They discovered this and completed the present invention. The present invention involves carrying out an esterification reaction between 2,2-bis(4-hydroxypolyoxyalkylenephenyl)propanes and acrylic acid or methacrylic acid in an organic solvent in the presence of a sulfonic acid catalyst having an aromatic ring. This is a method for producing diacrylate or dimethacrylate, which comprises cooling and separating a solid catalyst, followed by neutralization treatment. According to the method of the present invention, after the reaction solution is washed with an alkali, the phase separation between the organic solvent and the alkaline aqueous solution is extremely smooth, and the produced diacrylate or dimethacrylate can be recovered in good yield, and the separation Since there is little water in the organic solvent, drying is easy. The 2,2-bis(4-hydroxypolyoxyalkylenephenyl)propanes used in the present invention refer to 2,2-bis(4-hydroxypolyoxyalkylenephenyl)propane and its derivatives including halogen-substituted products. collectively referred to as In particular, in the present invention, the general formula (In the formula, R=H, CH ₃ , :X=Cl, Br; m, n
=1,2,3;a=0,1,2,3,4) are preferably used. in particular,
For example, 2,2-bis(4-hydroxyethoxyphenyl)propane, 2,2-bis(4-hydroxydiethoxyphenyl)propane, 2,2-bis(4-hydroxydiethoxyphenyl)propane,
2,2-bis(4-hydroxyethoxy-3,5
-dichlorophenyl)propane, 2,2-bis(4-hydroxyethoxy-3,5-dibromphenyl)propane, and the like are used. In the present invention, in order to improve the esterification reaction rate and obtain the target diacrylate or dimethacrylate, acrylic acid or methacrylic acid is added to 2,2-bis(4-hydroxypolyoxyalkylenephenyl)propanes. Use excessively. Generally, acrylic acid or metharylic acid is used in an amount of 2 moles or more, particularly 2.5 to 3.5 moles, per mole of 2,2-bis(4-hydroxyalkylenephenyl)propanes. In addition, examples of the sulfonic acid catalyst having an aromatic ring used in the present invention include benzenesulfonic acid,
(o, m, p-) toluenesulfonic acid, naphthalenesulfonic acid, etc. As described above, in the esterification reaction of the present invention, a sulfonic acid having an aromatic ring as a catalyst is used in excess in order to improve the reaction rate and suppress the polymerization of the diacrylate or dimethacrylate produced. Generally, 10 to 100 g of sulfonic acid having an aromatic ring is used per mole of 2,2-bis(4-hydroxypolyoxyalkylenephenyl)propane. The esterification reaction of the present invention is generally carried out in an organic solvent such as benzene or toluene under reflux using a conventional esterification apparatus. In this way, a reaction solution of an organic solvent containing unreacted acrylic acid or methacrylic acid and para-toluenesulfonic acid is obtained. Therefore, the reaction solution requires neutralization treatment. Therefore, the present invention requires that the aromatic ring-containing sulfonic acid be removed from the reaction solution in advance prior to the neutralization treatment. The method for removing the sulfonic acid having an aromatic ring from the reaction solution is not particularly limited, but for example, a method of cooling the reaction solution to precipitate the sulfonic acid having an aromatic ring and over-separating it is simple and effective. The cooling temperature of the reaction solution may be a temperature at which the sulfonic acid having an aromatic ring is precipitated, and is generally 20° C. or lower. However, if the cooling temperature of the reaction solution is too low, the target diacrylate or dimethacrylate will precipitate simultaneously with the sulfonic acid having an aromatic ring, which is not preferable. Therefore, the cooling temperature of the reaction solution is generally 20
It is selected in the range of 15 to 0°C, preferably 15 to 0°C. In the present invention, it is preferable to remove the aromatic ring-containing sulfonic acid from the reaction solution as much as possible, but it is not necessary to completely remove it. Next, in the present invention, the reaction solution from which the sulfonic acid having an aromatic ring has been removed is generally neutralized using an aqueous alkaline solution. As the alkali, water-soluble ones such as hydroxides and carbonates of alkali metals or alkaline metals are used, and for example, sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, etc. are preferably used. In the neutralization treatment of the present invention, the organic solvent and the alkaline aqueous solution of the reaction solution are hardly suspended and phase-separate easily in a short period of time. Therefore, the organic solvent of the reaction solution can be easily separated by ordinary decantation.
The desired diacrylate or dimethacrylate can be recovered in good yield from the organic solvent. Furthermore, since the organic solvent phase to be separated contains less water, drying required for post-treatment is simple. Examples and Comparative Examples are shown below to specifically explain the present invention, but the present invention is not particularly limited by these. Example 1 600 ml of benzene and 2,2-bis(4-
Hydroxyethoxy-3,5-dibromphenyl)propane (hereinafter abbreviated as Br ₄ -BAHE) 756
g (1.2 mol), 309 g (3.6 mol) of methacrylic acid, and 9 g of cuprous chloride were added and sufficiently dissolved, and then 60 g (0.35 mol) of para-toluenesulfonic acid monohydrate was added as a catalyst. The mixture was heated and reacted under reflux (84-88°C) for 4 hours, and 48 ml of water was produced and separated to stop the reaction. A highly viscous reaction solution was obtained. The reaction solution was then cooled to 10° C. and filtered to separate 42 g of a solid (identified as para-toluenesulfonic acid by infrared spectrum). On the other hand, 0.9N caustic soda aqueous solution 2 was added to the separated liquid and stirred. After standing still, benzene and the aqueous solution underwent phase separation in 5 minutes. After separating the benzene phase and dehydrating it by a conventional method, the reaction solvent, benzene, is expelled and crystallized.
783 g of Br ₄ BAHE dimethacrylate was obtained. Example 2 In Example 1, the reaction solution was cooled to 5° C. and filtered to separate 55 g of a solid (para-toluenesulfonic acid). Add 0.9N caustic soda aqueous solution 2 to the separated liquid.
was added and stirred. After standing still, benzene and the aqueous solution phase-separated in 2 minutes. By separating the benzene phase, dehydrating it by a conventional method, expelling the benzene, and crystallizing it, 802 g of Br ₄ BAHE diacrylate was obtained.
I got it. Comparative Example 1 To the reaction solution obtained in Example 1 (without cooling and separating para-toluenesulfonic acid)
0.9N caustic soda aqueous solution 2 was added and stirred. Thereafter, the solution was allowed to stand for 3 hours, but no phase separation between benzene and the aqueous solution occurred. Example 3 In Example 1, instead of Br ₄ -BAHE,
The esterification reaction was carried out in the same manner as in Example 1, except that 379 g (1.2 mol) of 2,2-bis(4-hydroxyethoxyphenyl)propane (hereinafter abbreviated as BAHE) was used. As a result, the reaction solution was cooled to 10° C. and filtered to separate 38 g of a solid (para-toluenesulfonic acid). 1N caustic soda aqueous solution 2 was added to the separated liquid and stirred. After 5 minutes of standing, benzene and the aqueous solution phase separated. The benzene phase was separated and worked up as in Example 1 to obtain 376 g of BAHE dimethacrylate. Comparative Example 2 In Example 2, the obtained reaction solution (without cooling and separating para-toluenesulfonic acid)
1N caustic soda aqueous solution 2 was added and stirred.
Thereafter, the solution was allowed to stand for 10 hours, but no phase separation between benzene and the aqueous solution occurred. Example 4 In Example 1, instead of methacrylic acid,
Except for using 259 g (3.6 mol) of acrylic acid.
The esterification reaction was carried out in the same manner as in Example 1. After the reaction was completed, the reaction solution was cooled to 5° C. and filtered to separate 53 g of a solid (para-toluenesulfonic acid). 1N caustic soda aqueous solution 2 was added to the separated liquid and stirred. Two minutes after standing, the benzene and aqueous solution phase-separated. By separating the benzene phase and post-treating as in Example 1, Br ₄ -BAHE
789 g of diacrylate was obtained. Comparative Example 3 In Example 3, the obtained reaction solution (without cooling and separating para-toluenesulfonic acid)
1N caustic soda aqueous solution 2 was added and stirred.
Thereafter, the solution was allowed to stand for 3 hours, but phase separation between benzene and the aqueous solution did not occur.

Claims (1)

[Claims] 1 Perform an esterification reaction between 2,2-bis(4-hydroxypolyoxyalkylenephenyl)propanes and acrylic acid or methacrylic acid in an organic solvent in the presence of a sulfonic acid catalyst having an aromatic ring, and convert the reaction solution into A method for producing diacrylate or dimethacrylate, which comprises cooling and separating a solid catalyst, followed by neutralization treatment.