JPH11193262A - Production of hydroxyalkyl mono (meth) acrylate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce the subject compound in high yield by making a hydrocar bon solvent exist in a reactional system when carrying out an esterifying reac tion of an alkanediol with (meth)acrylic acid and using an acidic ion exchange resin as a catalyst. SOLUTION: The esterifying reaction of an alkanediol with (meth)acrylic acid is carried out in the presence of a hydrocarbon solvent (preferably toluene or cyclohexane) using an acidic ion exchange resin (hereinafter referred to as a resin) as a catalyst. At the time of starting the reaction, moisture is preferably made to exist in an amount of 1-80 pts.wt. based on 100 pts.wt. dried weight of the resin in the reactional system. Furthermore, moisture in an amount of 1-60 pts.wt. based on 100 pts.wt. dried weight of the resin is preferably made to exist even in a reactional process. The (meth)acrylic acid is preferably used in an amount of 0.7-1.3 mol based on 1 mol alkanediol and the resin is preferably used in an amount of 0.1-1 on the basis of the dry weight thereof based on the weight of the alkanediol. The hydrocarbon solvent is preferably used in an amount of 1-5 times based on the weight of the alkanediol.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing hydroxyalkyl mono (meth) acrylate by an esterification reaction of alkanediol and (meth) acrylic acid.

[0002]

2. Description of the Related Art The simplest method for synthesizing hydroxyalkyl mono (meth) acrylate is a conventional esterification reaction of alkanediol with (meth) acrylic acid or a reaction between alkanediol and alkyl (meth) acrylate. Transesterification reactions are known.

[0003] However, when hydroxyalkyl mono (meth) acrylate is produced by these synthetic methods, hydroxyalkyl mono (meth) acrylate is contained in the reaction solution.
Since a large amount of by-product alkanediol di (meth) acrylate other than acrylate is contained, it is necessary to isolate the target hydroxyalkyl mono (meth) acrylate.

[0004] For this reason, many attempts have been made to selectively synthesize only hydroxyalkyl mono (meth) acrylate. For example, Tetrahedron Letters, 2
In 2,1971 (1979), a method of esterifying with a two-layer system of water and an organic solvent using sulfuric acid as a catalyst, and selectively extracting hydroxyalkyl monoacrylate generated in the organic layer,
A method for obtaining a monoester with a selectivity of 96% has been proposed. However, although this method has a high selectivity, it is not an efficient method because the reaction rate is low due to the esterification reaction in water and the concentrations of the substrate and the product are low.

[0005] Accounts of Chemical Research, 11,327 (1
978) proposes a method of selectively synthesizing a hydroxyalkyl monoacrylate by reacting trityl chloride bound to a polymer with a diol, selectively synthesizing a monotritylated product, then acylating, and then liberating from the polymer with an acid. Have been. However, such a method is not practical because the preparation of the reagent is difficult and the conversion of the diol is low.

In Tetrahedron, 49, 3065 (1993),
There has been proposed a method for synthesizing a monoester from a diester with high selectivity by an alcoholysis reaction using a dibutyltin oxide derivative as a catalyst, utilizing the stability of the resulting monoacrylate. This method shows high selectivity in the case of a specific alkanediol having 2 to 3 carbon atoms, but has a selectivity of 60% or less for alkanediols having 4 or more carbon atoms, which is not practical.

[0007] DE-A-1518572 proposes a method in which a diester by-produced in an esterification reaction is separated and then transesterified with a diol.
However, this method is not practical because it is complicated and difficult to separate diesters.

More recently, Journal of Synthetic Organic Chemistry, 308 (199
3) and J. Org.Chem., 59, 1191 (1994), utilizing the phenomenon that diols are easily adsorbed on silica gel and acidic ion exchange resin, using these as catalysts to form esters of diols and carboxylic acid esters. A method for selectively synthesizing a monoester by an exchange reaction has been proposed. This method has a high selectivity, but has a low reaction rate and a low substrate concentration. Therefore, it is hardly practical for industrial production.

[0009]

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a practical method for obtaining hydroxyalkyl mono (meth) acrylate in high yield.

[0010]

The first object of the present invention is to provide a method for producing a hydroxyalkyl mono (meth) acrylate by an esterification reaction between an alkanediol and (meth) acrylic acid. A method for producing hydroxyalkyl mono (meth) acrylate, characterized by using an acidic ion exchange resin as a catalyst in the presence of a solvent.

A second aspect of the present invention is the hydroxyalkyl according to the first aspect, wherein at least one part by weight of water is present in the reaction system based on 100 parts by weight of the dry weight of the acidic ion exchange resin at the start of the reaction. A method for producing a mono (meth) acrylate.

The third aspect of the present invention is characterized in that the reaction is carried out in a state where at least 1 part by weight of water is present in the reaction system with respect to 100 parts by weight of the dry weight of the acidic ion exchange resin in the reaction process. A method for producing a hydroxyalkyl mono (meth) acrylate according to the invention or the second invention.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, the alkane diol used as a raw material is not particularly limited. May be. As a linear alkanediol, for example, 1,2-
Ethanediol, 1,3-propanediol, 1,2-
Propanediol, 1,2-butanediol, 1,3-
Butanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,7-octanediol, 1,8-octanediol, 1,9-nonane Diol, 1,10-
Decanediol, 1,11-undecanediol, 1,
Examples thereof include 12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,15-pentadecanediol, and 1,16-hexadecanediol. Examples of the alkanediol having a substituent include 3-methyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, neopentyl glycol, and 3-chloro-1,2-propanediol. , 3-bromo-1,2-propanediol and the like. Particularly, in terms of selectivity of the produced hydroxyalkyl mono (meth) acrylate, the number of carbon atoms is 4 to 1;
The use of zero alkanediol is preferred.

The other raw material (meth) acrylic acid is acrylic acid or methacrylic acid, which is usually used in an amount of 0.1 to 10 mol per 1 mol of alkanediol, while maintaining selectivity. In order to produce a hydroxyalkyl mono (meth) acrylate with good productivity, it is preferable to use 0.5 to 5 mol. Particularly, considering productivity, 0.7 to 1.3 mol is preferable.

The type of the acidic ion exchange resin used as the catalyst is not particularly limited. For example, Amberlyst (registered trademark) and Amberlite (registered trademark) manufactured by Rohm and Haas Co., Ltd., and Diaion (registered trademark) manufactured by Mitsubishi Chemical Corporation are used. (Registered trademark) can be used. When the reaction is of a batch type, the amount of the acidic ion exchange resin used on a dry weight basis is usually 0.01 to 10 times, preferably 0.1 to 1 times the weight of the alkanediol. When the reaction is of a continuous type, the catalyst is used in a fixed bed, and the amount used is appropriately adjusted depending on the reaction conditions, the desired conversion, and the like.

The hydrocarbon solvent to be present in the reaction system is not particularly limited. Although a solvent can be used, toluene or cyclohexane is particularly preferred from the viewpoint that the conversion is improved and the production of diester is suppressed. The amount of the hydrocarbon solvent used is usually 0.1 to 10 times the weight of the alkanediol, and 1 to 5 times in order to produce hydroxyalkyl mono (meth) acrylate with high productivity while maintaining selectivity. Double is preferred.

In the reaction, only alkanediol, (meth) acrylic acid, a hydrocarbon solvent and an acidic ion exchange resin are sufficient in the reaction system, but the formation of diester is suppressed, and the desired product, hydroxyalkyl In order to increase the selectivity of the mono (meth) acrylate, it is preferable that moisture is present. This reaction is esterification, and water is generated as the reaction proceeds.Therefore, it is not necessary to have water in the system at the beginning of the reaction. By keeping
The selectivity of hydroxyalkyl mono (meth) acrylate in the initial stage of the reaction can be increased. The amount of water at the start of the reaction is preferably at least 1 part by weight based on 100 parts by weight of the dry weight of the acidic ion exchange resin. There is no particular upper limit on the amount of water at the start of the reaction, but it is preferably 80 parts by weight or less based on 100 parts by weight of the dry weight of the acidic ion exchange resin. The method for adding water is not particularly limited, but it is convenient to use an acidic ion exchange resin having a controlled water content.

It is preferable that moisture is present in the reaction process. In particular, when water is removed in the course of the reaction, the conditions are preferably adjusted so that the water in the reaction system does not become less than 1 part by weight based on 100 parts by weight of the dry weight of the acidic ion exchange resin. The upper limit of the amount of water in the reaction process is not particularly limited, but in order to maintain the reaction rate at a practical level, it is preferably 120 parts by weight or less, more preferably 60 parts by weight, based on 100 parts by weight of the dry weight of the acidic ion exchange resin. The following is preferred.

The pressure in the reaction system is usually 10 kPa to 500 kPa.
kPa, preferably 30 kPa to 110 kPa. The reaction temperature is usually from 0 to 120 ° C., preferably not lower than the azeotropic temperature of the hydrocarbon solvent and the generated water, specifically 40 ° C.
１００100 ° C. In order to suppress the generation of impurities having a high boiling point, 70 to 90 ° C is particularly preferable.

In the practice of the present invention, prevention of polymerization is extremely important for stable production of products. In order to prevent the polymerization, a known polymerization prevention method can be applied. It is effective to use a polymerization inhibitor. These polymerization inhibitors can be used in all steps from reaction to purification. The amount of the polymerization inhibitor to be used varies depending on the type of the polymerization inhibitor and other conditions, and cannot be specified unconditionally. However, when the reaction is started, it is usually 5 to the charged amount of the raw material (meth) acrylic acid. ~ 200
0 ppm is appropriate. Further, in order to enhance the polymerization preventing effect, it is preferable to introduce air into the liquid to be prevented from polymerization.

Next, an example of a purification process for obtaining a hydroxyalkyl mono (meth) acrylate as a product from the obtained reaction solution will be described.

First, the cation exchange resin is removed from the reaction solution by filtration, and the reaction solution adhering to the cation exchange resin is washed with a solvent such as acetone if necessary.
Concentrate and add to the filtrate of the reaction solution. Alkanediol di (meth) acrylate contained in the filtrate of the reaction solution is extracted and removed with an aliphatic hydrocarbon. This extraction operation may be performed repeatedly. Here, the aliphatic hydrocarbon used as the extractant is not particularly limited as long as it can easily dissolve the diester and hardly dissolve the monoester.Examples of such an extractant include pentane, cyclopentane, hexane, and the like. Cyclohexane, methylcyclohexane, heptane, cycloheptane, octane, isooctane and the like can be mentioned.

Next, to the liquid from which the alkanediol di (meth) acrylate has been extracted and removed, an aromatic hydrocarbon such as benzene, toluene and xylene or a halogenated hydrocarbon such as methylene chloride and chloroform is added and diluted. Is washed with an aqueous caustic solution to remove impurities having an acidic functional group and unreacted alkanediol, followed by washing with water to return the pH to neutral, so that the alkanediol content can be further reduced. As the diluting solvent used here, an aromatic hydrocarbon is preferable in consideration of toxicity and operability, and toluene is particularly preferable.

From the alkanediol di (meth) acrylate or alkanediol-reduced hydroxyalkyl mono (meth) acrylate solution thus obtained, the solvent is distilled off under reduced pressure to obtain the hydroxyalkyl mono (meth) acrylate. obtain. At this time, it is preferable to carry out the reaction while introducing air into the liquid in order to prevent polymerization. When the target product is a hydroxyalkyl mono (meth) acrylate having a relatively low boiling point, the purity can be further increased by subsequent purification by distillation.

In the above-mentioned purification step, the alkali washing and water washing operations and the alkanediol di (meth) acrylate extraction operation with an aliphatic hydrocarbon can be performed in reverse order.

Most of the hydroxyalkyl mono (meth) acrylates obtained according to the present invention have a very high boiling point and are liable to be polymerized, so that purification by distillation is difficult.
It is usually commercialized in the form of a residue from which the solvent has been removed. For this reason, coloring-causing substances may remain in the product, and preventing coloration of the product is extremely important for obtaining a high-quality product.

As a method of preventing coloring of the product, for example, a method of adding sodium phosphinate or the like as a coloring inhibitor in the reaction step can be mentioned. The amount of sodium phosphinate to be added is 0.01 to 10.0 mol%, particularly preferably 0.2 to 1.0 mol%, based on the charged (meth) acrylic acid. The coloring of the product can also be prevented by performing the solvent removing operation in the purification step at as low pressure and low temperature as possible. Specifically, the solvent removal is started at a pressure of 101 kPa or less,
As the low boiling point decreases, the degree of vacuum is increased.
6 kPa or less, preferably 1.3 kPa
It is preferable to set the following. Further, the temperature in the pot is preferably 80 ° C. or lower, particularly preferably 70 ° C. or lower.

As described above, the feature of the present invention is that in the esterification reaction between alkanediol and (meth) acrylic acid, a hydrocarbon solvent is present in the reaction system, and an acidic ion exchange resin is used as a catalyst. It is in. Less than,
The features of the present invention will be described in more detail.

According to the aforementioned Synthetic Society of Synthetic Organic Chemistry, 308 (1993) or J. Org. Chem., 59, 1191 (1994), the adsorbed water existing around the acidic ion-exchange resin as a catalyst is a diol. Plays an important role in the selective adsorption of
It is considered to be a factor for improving the selectivity of the monoester in the transesterification reaction. Actually, in these documents, a method is employed in which a large excess of an ester is used in order to improve the conversion, and a method of performing the reaction while excluding the generally used product alcohol is not employed. It is presumed that the purpose is to avoid the decrease in the selectivity of the monoester by removing the produced alcohol and simultaneously removing the water by azeotropic distillation.

From this fact, it is known that an acidic ion exchange resin, which is generally known as a catalyst for the esterification reaction, is used as a catalyst, and the carboxylic acid and the diol are removed while removing water in order to improve the conversion according to a conventional method. The method of carrying out the monoesterification reaction of the formula (1) would easily reduce the amount of adsorbed water existing around the acidic ion exchange resin as a catalyst, and it was easily expected by those skilled in the art that the method was not suitable.

However, contrary to expectation, the present inventors have found that in an esterification reaction, a monoester can be obtained with a high selectivity by using an acidic ion exchange resin as a catalyst. This finding indicates that stoichiometric reactions can be carried out at extremely high concentrations without the need for a large excess of ester as in the conventional case, which is a breakthrough in industrial sense.

In a general esterification reaction between a carboxylic acid and an alcohol, it is obvious that the reaction rate is reduced when water is positively present.
It is easily expected by those skilled in the art that the disproportionation of the produced monoester is promoted and the selectivity is reduced.

However, contrary to expectation, in the monoesterification reaction of a carboxylic acid and a diol using an acidic ion exchange resin as a catalyst, the active presence of water in the reaction system is effective for improving the selectivity of the monoester. It turned out to be.

[0034]

EXAMPLES The method of the present invention will be described in more detail with reference to examples. In the description, the conversion rate of the diol (hereinafter, simply referred to as conversion rate) and the selectivity of the generated hydroxyalkyl mono (meth) acrylate (hereinafter, simply referred to as selectivity) are defined as follows. Conversion (%) = B / A × 100 Selectivity (%) = C / B × 100 where A is the number of moles of the supplied diol, B is the number of moles of the reacted diol, and C is the hydroxyalkyl mono produced. It is the number of moles of (meth) acrylate.

The water content of the acidic ion exchange resin is defined as follows. Moisture content (%) = moisture weight / (dry weight of acidic ion exchange resin + moisture weight) x 100

Example 1 1,6-hexanediol 3
54 g (3 mol), acrylic acid 328 g (4.5 mol)
And a mixture of 648 g of hexane and 117 g of Amberlyst 15 wet (manufactured by Rohm and Haas Co.) adjusted to a water content of 33% (49 parts by weight based on 100 parts by weight of dry weight).
(Containing water by weight) and 0.65 g of hydroquinone monomethyl ether as a polymerization inhibitor were charged into a reaction flask. A 20-stage Aldershaw was installed above the reaction flask and a cooling tube was installed above the aldershaw.
The esterification reaction was carried out for 8 hours under total reflux while blowing air at.

After completion of the reaction, the acidic ion-exchange resin was removed by filtration, and the liquid adhering to the acidic ion-exchange resin was thoroughly washed with acetone to recover the reacted liquid. As a result of quantitative analysis of the recovered reaction solution by gas chromatography, the conversion of 1,6-hexanediol was 74.8%, and the selectivity of generated 6-hydroxyhexyl acrylate was 89.2%. The generation ratio of hexanediol diacrylate was 7.5 mol% based on 6-hydroxyhexyl acrylate.

Example 2 1,6-hexanediol 3
54 g (3 mol), acrylic acid 260 g (3.6 mol)
And a mixture of 648 g of toluene and 117 g of Amberlyst 15 wet (manufactured by Rohm and Haas Co.) adjusted to a water content of 33% (49 parts by weight based on 100 parts by weight of dry weight).
0.52 g of hydroquinone monomethyl ether as a polymerization inhibitor was added to the reaction flask. A 20-stage Aldershaw was installed above the reaction flask and a cooling tube was installed above it, the pressure was reduced so as to maintain the kettle temperature at 80 ° C, and the esterification reaction was carried out for 7.5 hours under total reflux while blowing air.

After completion of the reaction, the acidic ion-exchange resin was removed by filtration, and the liquid adhering to the acidic ion-exchange resin was thoroughly washed with acetone to recover the reacted liquid. As a result of quantitative analysis of the recovered reaction solution by gas chromatography, the conversion of 1,6-hexanediol was 77.3%, the selectivity of the produced 6-hydroxyhexyl acrylate was 90.1%, The production ratio of hexanediol diacrylate was 7.2 mol% based on 6-hydroxyhexyl acrylate.

Example 3 1,6-hexanediol 3
54 g (3 mol), acrylic acid 260 g (3.6 mol)
And a mixture of 648 g of toluene and 117 g of Amberlyst 15 wet (manufactured by Rohm and Haas Co.) adjusted to a water content of 33% (49 parts by weight based on 100 parts by weight of dry weight).
0.52 g of hydroquinone monomethyl ether as a polymerization inhibitor was added to the reaction flask. A 20-stage Aldershaw was installed above the reaction flask and a cooling tube was installed above the flask. The pressure was reduced so as to maintain the kettle temperature at 80 ° C., and the esterification reaction was performed for 6 hours under total reflux while blowing air, and then it took 2 hours. Then, 20 ml of water was distilled out of the system.

After the completion of the reaction, the acidic ion exchange resin was removed by filtration, and the liquid adhering to the acidic ion exchange resin was thoroughly washed with acetone to recover the liquid after the reaction. As a result of quantitative analysis of the recovered reaction solution by gas chromatography, the conversion of 1,6-hexanediol was 83.2%, the selectivity of the generated 6-hydroxyhexyl acrylate was 86.6%, The production ratio of hexanediol diacrylate was 9.6 mol% based on 6-hydroxyhexyl acrylate.

Example 4 1,6-hexanediol 5
A mixed solution of 90 g (5 mol), 432 g (6 mol) of acrylic acid and 648 g of cyclohexane was added with a water content of 35%.
Amberlyst 15wet (manufactured by Rohm and Haas Company) 231 g (5 parts per 100 parts by weight of dry weight)
(Containing 4 parts by weight of water), and 0.62 g of hydroquinone monomethyl ether as a polymerization inhibitor was added and charged into the reaction flask. A 20-stage Aldershaw and a condenser tube were attached above the reaction flask, and the esterification reaction was carried out at 90 ° C. while maintaining the kettle temperature at full reflux while blowing air for 7.5 hours.

After completion of the reaction, the acidic ion-exchange resin was removed by filtration, and the liquid adhering to the acidic ion-exchange resin was thoroughly washed with acetone to recover the reacted liquid. As a result of quantitative analysis of the recovered reaction solution by gas chromatography, the conversion of 1,6-hexanediol was 81.2%, and the selectivity of the produced 6-hydroxyhexyl acrylate was 87.8%. The production ratio of 1,6-hexanediol diacrylate was 8.4 mol% based on 6-hydroxyhexyl acrylate.

Example 5 1,6-hexanediol 3
54 g (3 mol), acrylic acid 260 g (3.6 mol)
And a mixed solution of 648 g of cyclohexane and a water content of 2
139 g of Amberlyst 15wet (manufactured by Rohm and Haas Co.) adjusted to 7% (containing 37 parts by weight of water with respect to 100 parts by weight of dry weight), and 0.52 g of hydroquinone monomethyl ether as a polymerization inhibitor were added. The reaction flask was charged. The temperature of the kettle was set at 87 ° C., and the reaction was carried out while draining water from above the flask and blowing air. The reaction was carried out for 6 hours, and the reaction was stopped when 56 ml of water had flowed out.

After completion of the reaction, the acidic ion-exchange resin was removed by filtration, and the liquid adhering to the acidic ion-exchange resin was thoroughly washed with acetone to recover the reacted liquid. As a result of quantitative analysis of the recovered reaction solution by gas chromatography, the conversion of 1,6-hexanediol was 77.8% and the selectivity of 6-hydroxyhexyl acrylate produced was 92.0%. The production ratio of 1,6-hexanediol diacrylate was 6.3 mol% based on 6-hydroxyhexyl acrylate. The water content in the reaction solution was 13 parts by weight based on 100 parts by weight of the dry weight of the acidic ion exchange resin. Also,
When the reaction was analyzed in detail, the conversion after 1 hour of the reaction was 39%, the water outflow was 12 ml, the conversion after 2 hours was 49%, the water outflow was 23 ml, and the conversion after 3 hours was 58
%, The outflow of water was 33 ml, the conversion after 4 hours was 67%, the outflow of water was 39 ml, the conversion after 5 hours was 73%, and the outflow of water was 49 ml. Water was always present in an amount of at least 10 parts by weight based on 100 parts by weight of the dry weight of the acidic ion exchange resin.

Example 6 1,6-hexanediol 3
54 g (3 mol), acrylic acid 260 g (3.6 mol)
And a mixed solution of 648 g of cyclohexane and a water content of 2
139 g of Amberlyst 15wet (manufactured by Rohm and Haas Co.) adjusted to 7% (containing 37 parts by weight of water with respect to 100 parts by weight of dry weight), and 0.52 g of hydroquinone monomethyl ether as a polymerization inhibitor were added. The reaction flask was charged. The temperature of the kettle was set at 87 ° C., and the reaction was carried out while draining water from above the flask and blowing air. The reaction was performed for 10 hours, and the reaction was stopped when 75 ml of water had flowed out.

After completion of the reaction, the acidic ion-exchange resin was removed by filtration, and the liquid adhering to the acidic ion-exchange resin was thoroughly washed with acetone to recover the reacted liquid. As a result of quantitative analysis of the recovered reaction solution by gas chromatography, the conversion of 1,6-hexanediol was 91.7%, and the selectivity of the produced 6-hydroxyhexyl acrylate was 84.4%. The generation ratio of hexanediol diacrylate was 12.1 mol% based on 6-hydroxyhexyl acrylate. The water in the reaction solution is the dry weight of the acidic ion exchange resin.
5 parts by weight to 00 parts by weight.

Example 7 1,6-hexanediol 3
54 g (3 mol), acrylic acid 260 g (3.6 mol)
Amberlyst 15Edry (manufactured by Rohm and Haas) 102 g in a mixed solution of hexane and 648 g of cyclohexane
(Containing 0 parts by weight of water with respect to 100 parts by weight of dry weight) and 0.52 g of hydroquinone monomethyl ether as a polymerization inhibitor were added and charged into a reaction flask. The temperature of the kettle was set at 87 ° C., and the reaction was carried out while draining water from above the flask and blowing air. The reaction was carried out for 6 hours, and the reaction was stopped when 36 ml of water had flowed out.

After completion of the reaction, the acidic ion-exchange resin was removed by filtration, and the liquid adhering to the acidic ion-exchange resin was thoroughly washed with acetone to recover the reacted liquid. As a result of quantitative analysis of the recovered reaction solution by gas chromatography, the conversion of 1,6-hexanediol was 92.5%, the selectivity of the generated 6-hydroxyhexyl acrylate was 80.1%, The production ratio of hexanediol diacrylate was 15.4 mol% based on 6-hydroxyhexyl acrylate. Also,
The moisture in the liquid after the reaction was 11 parts by weight based on 100 parts by weight of the dry weight of the acidic ion exchange resin.

[Reference] In the above Examples 1 to 7, the obtained reaction solution was concentrated under reduced pressure and washed with hexane having the same mass as the residue 6 to 10 times to reduce the content of diester to the monoester. To 1 mol% or less.

Comparative Example 1 1,6-hexanediol 3
54 g (3 mol), acrylic acid 260 g (3.6 mol)
28 g of p-toluenesulfonic acid monohydrate and 0.52 g of hydroquinone monomethyl ether as a polymerization inhibitor were added to a mixed solution of 648 g of cyclohexane, and the mixture was charged into a reaction flask. The temperature of the kettle was set at 87 ° C., and the reaction was carried out while draining water from above the flask and blowing air. The reaction was carried out for 2 hours, and the reaction was stopped when 20 ml of water had flowed out.

As a result of quantitative analysis of the obtained reaction solution by gas chromatography, the conversion of 1,6-hexanediol was 75.5%, the selectivity of the produced 6-hydroxyhexyl acrylate was 70.7%, The production ratio of 1,6-hexanediol diacrylate was 23.4 mol% based on 6-hydroxyhexyl acrylate.

Comparative Example 2 1,6-hexanediol 3
54 g (3 mol), acrylic acid 260 g (3.6 mol)
28 g of p-toluenesulfonic acid monohydrate and 0.52 g of hydroquinone monomethyl ether as a polymerization inhibitor were added to a mixed solution of 648 g of cyclohexane, and the mixture was charged into a reaction flask. The temperature of the kettle was set at 87 ° C., and the reaction was carried out while draining water from above the flask and blowing air. The reaction was allowed to proceed for 4 hours, and the reaction was stopped when 36 ml of water had flowed out.

As a result of quantitative analysis of the obtained reaction solution by gas chromatography, the conversion of 1,6-hexanediol was 89.8%, the selectivity of 6-hydroxyhexyl acrylate was 62.9%, The generation ratio of 1,6-hexanediol diacrylate was 30.1 mol% based on 6-hydroxyhexyl acrylate.

Example 8 1,6-hexanediol 5
A mixed solution of 90 g (5 mol), 432 g (6 mol) of acrylic acid and 1181 g of cyclohexane was added with a water content of 27%.
Amber list adjusted to 15% (ROHM &
179 g (having a water content of 37 parts by weight with respect to 100 parts by weight of dry weight), 0.43 g of hydroquinone and 4-hydroxy-2,2,6 as polymerization inhibitors
6-tetramethylpiperidine-N-oxyl 0.022
g, sodium phosphinate 3.18 as a coloring inhibitor
g was added and charged to the reaction flask. Pot temperature 80-85
At ℃, the reaction was carried out while draining water from above the flask.
The reaction was carried out for 6 hours, and the reaction was stopped when 103 ml of water was extracted.

After completion of the reaction, the acidic ion-exchange resin was removed by filtration, and the liquid adhering to the acidic ion-exchange resin was thoroughly washed with acetone to recover the reacted liquid. As a result of quantitative analysis of the recovered reaction solution by gas chromatography, the conversion of 1,6-hexanediol was 84.4%, and the selectivity of the produced 6-hydroxyhexyl acrylate was 85.4%. The generation ratio of hexanediol diacrylate was 9.0 mol% based on 6-hydroxyhexyl acrylate. The water content of the reaction solution is 10% by dry weight of the acidic ion exchange resin.
It was 17 parts by weight with respect to 0 parts by weight.

Next, cyclohexane was added to the recovered reaction solution to extract and remove 1,6-hexanediol diacrylate. Subsequently, the residue diluted with toluene was washed with an aqueous sodium hydroxide solution, and further washed with water to remove acidic substances and unreacted 1,6-
Hexanediol was removed from the aqueous layer. To this residue, 0.10 g of hydroquinone monomethyl ether was added, and toluene was removed under reduced pressure while introducing air into the solution so that the temperature in the kettle did not exceed 70 ° C., leaving 450 g of 6-hydroxyhexyl acrylate as the kettle residue. I got At this time, polymerization did not occur at all from the reaction to the purification process, and the APHA of the obtained 6-hydroxyhexyl acrylate was 40%.
And there was almost no coloring.

Example 9 Amberlyst 15wet (manufactured by Rohm and Haas) 17 adjusted to a water content of 27%
Amberlite 200C (H type) (manufactured by Rohm and Haas) 17 adjusted to a water content of 24% instead of 9 g
The reaction was carried out in the same manner as in Example 8, except that 9 g (containing 32 parts by weight of water with respect to 100 parts by weight of dry weight) was used. At this time, the amount of water extracted was 74 ml.

After completion of the reaction, the acidic ion-exchange resin was removed by filtration, and the liquid adhering to the acidic ion-exchange resin was washed well with acetone. −
The conversion of hexanediol was 89.5%,
The selectivity of hydroxyhexyl acrylate is 79.8
%, The production ratio of 1,6-hexanediol diacrylate was 11.
9 mol%. The water content in the reaction solution was 35 parts by weight based on 100 parts by weight of the dry weight of the acidic ion exchange resin.

Next, n-hexane was added to the recovered reaction solution to extract and remove 1,6-hexanediol diacrylate. Subsequently, the residue was diluted with toluene and washed with an aqueous sodium hydroxide solution, and further washed with water to remove acidic substances and unreacted 1,6-hexanediol from the aqueous layer. To this residue was added 0.08 g of hydroquinone monomethyl ether, and while introducing air into the solution, toluene was removed under reduced pressure so that the temperature in the kettle did not exceed 70 ° C., and 6-hydroxyhexyl acrylate was added as the kettle residue. 376 g were obtained. At this time, no polymerization occurred from the reaction through the purification step, and the obtained 6
APHA of -hydroxyhexyl acrylate was 30 and there was almost no coloring.

Example 10 Neopentyl glycol 5
Amberlist 15wet (manufactured by Rohm and Haas Co.) 183 adjusted to a water content of 26% after washing with a mixed solution of 20 g (5 mol), 432 g (6 mol) of acrylic acid and 1041 g of cyclohexane, followed by washing with water, acetone, and air drying.
g (containing 35 parts by weight of water with respect to 100 parts by weight of dry weight), 0.43 g of hydroquinone and 0.022 g of 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl as a polymerization inhibitor Then, 3.18 g of sodium phosphinate was added as a coloring inhibitor, and the mixture was charged into a reaction flask. The reaction was carried out at a pot temperature of 80 to 85 ° C. while draining water from above the flask. The reaction was carried out for 6.5 hours, and the reaction was stopped when 94 ml of water was extracted.

After completion of the reaction, the acidic ion-exchange resin was removed by filtration, and the liquid adhering to the acidic ion-exchange resin was washed well with acetone. Is 92.8%, and the selectivity of the formed neopentyl glycol monoacrylate is 87.0.
% Of neopentyl glycol diacrylate is 1 to neopentyl glycol monoacrylate.
It was 4.9 mol%. In addition, the water in the reaction solution is 4 parts by weight based on 100 parts by weight of the dry weight of the acidic ion exchange resin.
8 parts by weight.

Next, the recovered reaction solution was washed with an aqueous sodium hydroxide solution, and further washed with water to remove acidic substances and unreacted neopentyl glycol from the aqueous layer. Subsequently, n-hexane was added to the diluted solution obtained by adding methanol and water to the residual solution, and the diester was extracted and removed. 0.11 g of hydroquinone monomethyl ether was added to the remaining liquid, and methanol was removed under reduced pressure while introducing air into the liquid so that the temperature in the kettle did not exceed 55 ° C. Toluene was added to the remaining liquid to extract the desired neopentyl glycol monoacrylate, and toluene was removed under reduced pressure while introducing air into the toluene layer so that the temperature in the kettle did not exceed 70 ° C. 382 g of neopentyl glycol monoacrylate was obtained.
At this time, polymerization did not occur at all from the reaction to the purification step, and the APHA of the obtained neopentyl glycol monoacrylate was 48, and there was almost no coloring.

Example 11 553 g (5 mol) of 3-chloro-1,2-propanediol, 516 methacrylic acid
g (6 mol) and 1181 g of cyclohexane was added to Amberlyst 15wet adjusted to a water content of 27%.
186 g (manufactured by Rohm and Haas) (dry weight 1)
37 parts by weight of water per 100 parts by weight), 0.51 g of hydroquinone as a polymerization inhibitor and 4-hydroxy-2,2,6,6-tetramethylpiperidine-N-
0.026 g of oxyl and 3.18 g of sodium phosphinate as a coloring inhibitor were added to the reaction flask. The reaction was carried out at a temperature in the kettle of 80 to 85 ° C. while draining water from above the flask with a decanter. The reaction was carried out for 16 hours, and the reaction was stopped when 61 ml of water was extracted.

After completion of the reaction, the acidic ion-exchange resin was removed by filtration, and the liquid adhering to the acidic ion-exchange resin was washed well with acetone. The conversion of -1,2-propanediol is 91.2%,
The selectivity of the produced 3-chloro-1,2-propanediol monomethacrylate is 87.8%,
The production ratio of 2-propanediol dimethacrylate is 3
12.5 mol% based on -chloro-1,2-propanediol monomethacrylate. The water content of the reaction solution was 58 parts by weight based on 100 parts by weight of the dry weight of the acidic ion exchange resin.

Next, n-hexane was added to the recovered reaction solution to extract and remove 3-chloro-1,2-propanediol dimethacrylate. The residue was diluted with toluene and washed with an aqueous sodium hydroxide solution.
Further, by washing with water, acidic substances and unreacted 3-chloro-1,2-propanediol were removed from the aqueous layer. To this residue, 0.08 g of hydroquinone monomethyl ether was added, and toluene was removed under reduced pressure while introducing air into the solution so that the temperature in the kettle did not exceed 70 ° C. 398 g of 2,2-propanediol monomethacrylate was obtained. At this time, no polymerization occurred from the reaction through the purification step, and the obtained 3
APHA of -chloro-1,2-propanediol monomethacrylate was 50, and there was almost no coloring.

[0067]

According to the present invention, hydroxyalkyl mono (meth) acrylate can be obtained in high yield.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Sonobe 20-1, Miyukicho, Otake City, Hiroshima Prefecture Mitsubishi Rayon Co., Ltd. Central Research Laboratory

Claims (3)

[Claims] 1. A method for producing a hydroxyalkyl mono (meth) acrylate by an esterification reaction between an alkanediol and (meth) acrylic acid, wherein a hydrocarbon solvent is present in the reaction system, and an acidic ion exchange resin is used as a catalyst. A method for producing a hydroxyalkyl mono (meth) acrylate, which is used. 2. The hydroxyalkyl mono (meth) acrylate according to claim 1, wherein at least one part by weight of water is present in the reaction system based on 100 parts by weight of the dry weight of the acidic ion exchange resin at the start of the reaction. Manufacturing method. 3. The reaction according to claim 1, wherein the reaction is carried out in a state where at least 1 part by weight of water is present in the reaction system with respect to 100 parts by weight of dry weight of the acidic ion exchange resin in the reaction process. A method for producing hydroxyalkyl mono (meth) acrylate.