JPH06256271A - Production of alkylaminoalkyl acrylate or methacrylate - Google Patents

Abstract

PURPOSE:To suppress the formation of a by-product and selectively obtain a compound by recovering the by-product, formed and remaining in the transesterification of an acrylic or a methacfylic ester with an alkylamino- alcohol and reutilizing the resultant by-product. CONSTITUTION:(A) An acrylic or a methacrylic acid ester expressed by the formula CH2=CR1COOR2 (R1 is H or CH3; R2 is 1-4C alkyl) (e.g. methyl methacrylate) and (B) an alkylamino-alcohol expressed by the formula R3OH (R3 is alkylaminoalkyl) (e.g. dimethylamino-ethanol) are subjected to the transesterification in the presence of potassium carbonate, rubidium carbonate, etc., as a catalyst to afford the objective compound expressed by the formula CH2=CR1COOR3 (e.g. dimethylaminoethyl methacrylate). In the process, a by- product, formed and/or remaining therein, e.g. a compound expressed by the formula R3OCH2CHR1COOR2 is distilled, recovered and then readed to the same reactional system. Thereby, the amount of the new by-product can be suppressed to <=3%.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an alkylaminoalkyl ester of acrylic acid or methacrylic acid (hereinafter referred to as "(meth) acrylic acid"). The present invention relates to a method of suppressing and improving the selectivity of raw materials to products. The alkylaminoalkyl ester of (meth) acrylic acid is
Since it has an amino group in the molecule, it is used as a dyeability modifier for fibers, as an antistatic agent for plastics, and as a polymer obtained by polymerizing / copolymerizing these monomers, it is used as a paper strength enhancer, toner binder. It is useful as a material for UV-curable printing, a resin for paints, a polymer flocculant, and an ion exchange resin.

[0002]

2. Description of the Related Art A method for synthesizing an alkylaminoalkyl ester of (meth) acrylic acid by a transesterification reaction of a (meth) acrylic acid ester is already known, and many methods using various catalysts have been proposed. Has been done. For example, one using an alkali metal carbonate (JP-A-57-70845), one using an alkali metal hydrogen carbonate (JP-A-62-242652), one using an alkali metal phosphate. (JP-A-62-230755), using organic tin halide (JP-A-55-9)
4342 publication) and the like.

[0003]

However, when an alkylaminoalkyl ester of (meth) acrylic acid is synthesized using the above catalysts, a considerable amount of by-products are produced. As the by-product, an alkylamino alcohol is added to the double bond portion of the (meth) acrylic acid ester as a raw material, or an alcohol by-produced in the system is added to the following general formula (4). ~ (7), (Chemical formula 5)

R ₃ OCH ₂ CHR ₁ COOR ₂ (4) R ₂ OCH ₂ CHR ₁ COOR ₃ (5) R ₃ OCH ₂ CHR ₁ COOR ₃ (6) R ₂ OCH ₂ CHR ₁ COOR ₂ (7) (Formula) In the formula, R ₁ is hydrogen or a methyl group, R ₂ has 1 to 4 carbon atoms
R ₃ is an alkylaminoalkyl group. Hereinafter, these are the same. ) Is mentioned. For example, when an alkylaminoalkyl ester of (meth) acrylic acid is synthesized using potassium carbonate, potassium hydrogen carbonate, trirubidium phosphate, etc. as a catalyst, the production rate of the above-mentioned by-products is about 10%, and these are In addition to lowering the yield, it becomes an industrial waste, which requires many steps and costs in its treatment.

In the present invention, there is provided a method of suppressing the production of by-products, which is the above-mentioned drawback, and improving the selectivity of raw materials to products when producing alkylaminoalkyl esters of (meth) acrylic acid. The purpose is to provide.

[0005]

Means for Solving the Problems As a result of intensive studies conducted by the present inventors in order to achieve the above object, the by-product produced during the synthesis of an alkylaminoalkyl ester of (meth) acrylic acid is a raw material. The following formulas (8) to (11), and (meth) acrylic acid ester or alkylamino alcohol, alkylaminoalkyl ester of (meth) acrylic acid as a product, or alcohol produced by transesterification 6)

[Chemical 6] It was clarified that there is an equilibrium relationship represented by.

As a result of further study, the equations (8) to (11),
The content of the by-product in the equilibrium state of (Chemical Formula 6) is about 10 to 50% by weight based on the product content, although it varies depending on the synthesis conditions such as the type of raw material and the molar ratio. I got the knowledge. Furthermore, if the present invention is in an equilibrium state with a content ratio within this range, the present inventors will be able to synthesize the alkylaminoalkyl ester of (meth) acrylic acid with the above-mentioned general formula (4).
It was found that the production of these new by-products can be greatly suppressed by adding the by-products represented by (7) and (Chemical Formula 5) at the time of charging the raw materials or during the reaction, and finally completed the present invention. did.

That is, the present invention is based on the general formula (1)

Embedded image CH ₂ ═CR ₁ COOR ₂ Acrylic acid or methacrylic acid ester represented by the formula (1) and the general formula (2)

[Image Omitted] By transesterification with an alkylamino alcohol represented by R ₃ OH (2), a compound of the general formula (3)

## STR00009 ## CH ₂ ═CR ₁ COOR ₃ Byproducts produced and / or remaining during the production of the alkylaminoalkyl ester of (meth) acrylic acid represented by (3) are recovered by distillation, The method for producing an alkylaminoalkyl ester of (meth) acrylic acid is characterized in that it is added to the reaction system shown above.

The present invention will be described in detail below. The method for producing an alkylaminoalkyl ester of (meth) acrylic acid that enables the present invention is carried out by a transesterification reaction between a (meth) acrylic acid ester and an alkylamino alcohol using a catalyst. JP-A-57-70845, JP-A-62-242652,
The production methods described in JP-A-62-230755 and JP-A-55-94342 can be mentioned.

Generally, the method for synthesizing an alkylaminoalkyl ester of (meth) acrylic acid according to the above is generally carried out by using the following general formula (1)

[Chemical Formula 10] CH ₂ ═CR ₁ COOR ₂ (meth) acrylic acid ester represented by the following general formula (2) (Chemical Formula 11)

Embedded image This is carried out by transesterification with an alkylamino alcohol represented by R ₃ OH (2).

Specific examples of the (meth) acrylic acid ester represented by the above general formula (1) (Chemical Formula 10) include methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, and isopropyl methacrylate. And the other raw material, the general formula (2)
Examples of the alkylamino alcohol represented by Chemical formula 11 include dimethylaminoethanol, diethylaminoethanol, dimethylaminopropanol, t-butylaminoethanol, dibutylaminomethanol and the like.

The (meth) acrylic acid ester and the alkylamino alcohol can be charged in any range as long as the reaction practically proceeds, but usually (meth) is added to 1 mol of the alkylamino alcohol. Acrylic ester is in the range of 1.2 to 10 moles, preferably 1.5 to 5 moles.

The catalyst used here is generally:
Any substance having catalytic activity may be used, and examples thereof include potassium carbonate, rubidium carbonate, cesium carbonate, potassium hydrogen carbonate, rubidium hydrogen carbonate, cesium hydrogen carbonate, tripotassium phosphate, trisodium phosphate, and trirubidium phosphate.
Dibutyltin dichloride or the like is used, and the amount used is usually 0.01 to 2.0% by weight, preferably 0.02 to 1.0% by weight, based on the total amount of the (meth) acrylic acid ester and the alkylamino alcohol.

When the transesterification reaction is carried out as described above,
Usually, the reaction liquid is the target product, alkylaminoalkyl ester of (meth) acrylic acid, unreacted raw materials, and by-products represented by the following general formulas (4) to (7) and (Chemical Formula 12)

Embedded image R ₃ OCH ₂ CHR ₁ COOR ₂ (4) R ₂ OCH ₂ CHR ₁ COOR ₃ (5) R ₃ OCH ₂ CHR ₁ COOR ₃ (6) R ₂ OCH ₂ CHR ₁ COOR ₂ (7) mixture Obtained as. The amount of the by-product varies depending on the synthesis conditions such as the catalyst and the molar ratio of the raw materials, but usually about 3 to 10% by weight is produced with respect to the target alkylaminoalkyl ester of (meth) acrylic acid. .

In the present invention, the alkylaminoalkyl ester of (meth) acrylic acid is separated and obtained from the reaction solution after completion of the reaction, these by-products are recovered, and these are added in the next synthesis reaction. Is the way.

The method of recovering the by-product and the method of adding it to the next reaction system in the present invention will be described in detail below. First,
The method of treating the reaction liquid after the reaction in the present invention is carried out by distilling the reaction liquid after the end of the transesterification reaction to obtain (meth) acrylic acid ester, alkylamino alcohol, and Formula (7) (Formula 13)

Embedded image By-products represented by R ₂ OCH ₂ CHR ₁ COOR ₂ (7) are recovered.

The distillation operation conditions here vary depending on the kind of the starting material alkylamino alcohol, but usually,
A pressure of 1 to 500 Torr, a temperature of 50 to 200 ° C, and a distillation time of 0.5 to 10 hours are possible. In the present invention, after carrying out the above-mentioned distillation operation, further distillation is carried out to obtain a product, an alkylaminoalkyl ester of (meth) acrylic acid, as a distillate. The distillation operation conditions in this case are usually a pressure of 1 to 100 Torr, a temperature of 50 to 200 ° C., and a distillation time of 0.5 to 10 hours.

A residue remains at the end by these distillation operations. In the present invention, by further distilling this residue, the following general formulas (4) to (6),

Embedded image By-products represented by R ₃ OCH ₂ CHR ₁ COOR ₂ (4) R ₂ OCH ₂ CHR ₁ COOR ₃ (5) R ₃ OCH ₂ CHR ₁ COOR ₃ (6) can be obtained.

The by-products represented by the general formulas (4) to (7) recovered by the above two distillation operations are added in the next synthesis of the alkylaminoalkyl ester of (meth) acrylic acid, React. The addition of these by-products may be carried out by mixing the obtained total amount at the time of charging the raw materials, or by a method of adding them during the reaction. In addition, when the by-product is added, the volume charged to the kettle increases by that amount, and there is a concern that the efficiency of the kettle will decrease. This can be prevented by adding a part. In the present invention, the new production amount of the by-product may be set to 1/2 or less as compared with the conventional one, although it varies depending on the synthesis reaction conditions or the conditions such as the amount of the by-product added. It is possible.

[0019]

The present invention will be described in detail below with reference to examples. In the following, "%" is on a molar basis unless otherwise specified, and the components in the reaction mixture were analyzed by gas chromatography.

Synthesis Example 1 500 g of methyl methacrylate and 178 g of dimethylaminoethanol as raw materials were placed in a 1 Lit glass container equipped with a stirrer equipped with a packed distillation column, and 1.2 g of phenothiazine as a polymerization inhibitor was added thereto. It was Next, the pressure in the system was set to 400 Torr and the temperature was set to 90 ° C. to bring the mixture to a state of total reflux. In this state, 23 g of a 5 wt% potassium carbonate methanol solution was added as a catalyst over 5 hours. The methanol produced in the system was distilled as a methanol / methyl methacrylate azeotrope at a reflux ratio of 2 to 4 so that the distillation column overhead temperature was maintained at 58 to 60 ° C. After 5 hours from the start of the reaction, the conversion rate of dimethylaminoethanol became 99%,
The product produced 91% of dimethylaminoethyl methacrylate, and 7% of the remaining 8% was a by-product. next,
The pressure in the system was changed from 400 Torr to 35 Torr over 1 hour, and excess raw material methyl methacrylate was distilled at a distillation temperature of 60 ° C. Furthermore, the pressure in the system is 10 Torr from 35 Torr over 1 hour.
Pre-distillation was performed at a distillation temperature of 60 to 70 ° C. as Torr, and unreacted dimethylaminoethanol was extracted. Then, the pressure was set to 10 Torr, the distillation temperature was set to 68 to 70 ° C., and distillation was performed for 2 hours to obtain a product component. The obtained dimethylaminoethyl methacrylate was 289 g, and the yield was 90% based on the charged dimethylaminoethanol. The amount of residue was 25 g. The results are shown in Table 1.

Synthesis Example 2 The same operation as in Synthesis Example 1 was carried out except that in Synthesis Example 1, diethylaminoethanol was used as the alkylamino alcohol, and the type and amount of the catalyst shown in Table 1 were used. The results are shown in Table 1.

Synthesis Example 3 The same operation as in Synthesis Example 1 was carried out except that in Synthesis Example 1, the alkylamino alcohol was dibutylaminomethanol and the type and amount of the catalyst shown in Table 1 were used. The results are shown in Table 1.

Synthetic Example 4 The same operation as in Synthetic Example 1 was carried out except that t-butylaminoethanol was used as the alkylamino alcohol and the type and amount of the catalyst shown in Table 1 were used. did. The results are shown in Table 1.

Synthesis Example 5 The same operation as in Synthesis Example 1 was carried out except that in Synthesis Example 1, dimethylaminoethanol was used as the alkylamino alcohol and the type and amount of the catalyst shown in Table 1 were used. The results are shown in Table 1.

[0025]

[Table 1] Note 1) The product yield is based on the charged alkylamino alcohol. Note 2) The production rate of by-products is based on the charged alkylamino alcohol. Note 3) Selectivity to products is the ratio of products based on the converted raw material alkylamino alcohol.

Example 1 25 g of the residue obtained in Synthesis Example 1 was distilled with an evaporator at a pressure of 1 Torr and an oil bath temperature of 150 ° C. for 1 hour to obtain 21 g of a by-product. Next, the same operation as in Synthesis Example 1 was carried out except that all the by-products obtained above were charged together with the raw materials. As a result, the conversion rate of dimethylaminoethanol was 94%, the yield of dimethylaminoethyl methacrylate was 91%, and the new production rate of by-products was 2.9%.
%Met. The results are shown in Table 2.

Example 2 The residue obtained in Synthesis Example 2 was treated in the same manner as in Example 1 to obtain a by-product in advance. Next, the same raw material and the same kind and amount of catalyst as in Synthesis Example 2 were used, and the same operation as in Synthesis Example 1 was carried out except that all the by-products obtained above were charged. The results are shown in Table 2.

Example 3 The residue obtained in Synthesis Example 3 was treated in the same manner as in Example 1 to obtain a by-product in advance. Next, the same raw material and the same kind and amount of catalyst as those in Synthesis Example 3 were used, and the same operation as in Synthesis Example 1 was carried out except that all of the by-products obtained above were charged. The results are shown in Table 2.

Example 4 The residue obtained in Synthesis Example 4 was treated in the same manner as in Example 1 to obtain a by-product in advance. Next, the same raw material and the same kind and amount of catalyst as in Synthesis Example 4 were used, and the same operation as in Synthesis Example 1 was carried out except that all the amount of the by-product obtained above was charged. The results are shown in Table 2.

Example 5 The residue obtained in Synthesis Example 5 was treated in the same manner as in Example 1 to obtain a by-product in advance. Next, the same raw material and the same kind and amount of catalyst as in Synthesis Example 5 were used, and the same operation as in Synthesis Example 1 was carried out except that all the by-products obtained above were charged. The results are shown in Table 2.

[0031]

[Table 2] Note 1) The product yield is based on the charged alkylamino alcohol. Note 2) The production rate of new by-products is calculated by excluding the amount of by-products that had already been added when the raw materials were charged.
It is based on the charged alkylamino alcohol. Note 3) Selectivity to products is the ratio of products based on the converted raw material alkylamino alcohol.

[0032]

INDUSTRIAL APPLICABILITY In the method for producing an alkylaminoalkyl ester of (meth) acrylic acid according to the present invention, the by-product produced in the synthetic process is used in the next synthesis, so that the production of a new by-product is increased. It is possible to reduce. That is, Synthesis Examples 1 to 5 which are conventional methods
The production of by-products is 7-9%, whereas in Examples 1-5 within the scope of the present invention, the new production is 3%.
% Or less. Therefore, in the method for producing an alkylaminoalkyl ester of (meth) acrylic acid according to the present invention, it is possible to greatly suppress the production of by-products that have been industrial wastes in the past, and to select raw materials for products. The rate can be improved.

 ─────────────────────────────────────────────────── (72) Inventor Eiichi Sagawa 1900 Togo, Mobara-shi, Chiba Prefecture Mitsui Toatsu Chemical Co., Ltd. (72) Inventor Yoshihiro Nodate 1900, Togo, Mobara-shi Chiba Prefecture Mitsui Toatsu Chemical Co., Ltd.

Claims (2)

[Claims] 1. General formula (1) (Chemical formula 1) ## STR1 ## CH ₂ ═CR ₁ COOR ₂ (1) (wherein R ₁ is hydrogen or a methyl group, and R ₂ has 1 to 4 carbon atoms.
Is an alkyl group. ) And an acrylic acid or methacrylic acid ester represented by the general formula (2) (Chemical Formula 2) and R ₃ OH (2) (in the formula, R ₃ represents an alkylaminoalkyl group). By a transesterification reaction with an alkylamino alcohol, a compound represented by the general formula (3) (Chemical formula 3): CH ₂ ═CR ₁ COOR ₃ (3) (in the formula, R ₁ and R ₃ are the same as above) Characterized in that the by-product produced and / or remaining during the production of the alkylaminoalkyl ester of acrylic acid or methacrylic acid is recovered by distillation, and is added to the next reaction system shown above. Process for producing alkylaminoalkyl ester of acid or methacrylic acid. 2. The by-products are represented by the general formulas (4) to (7) and (Chemical Formula 4): R ₃ OCH ₂ CHR ₁ COOR ₂ (4) R ₂ OCH ₂ CHR ₁ COOR ₃ (5) R ₃ OCH ₂ CHR ₁ COOR ₃ (6) R ₂ OCH ₂ CHR ₁ COOR ₂ (7) (In the formula, R ₁ , R ₂ and R ₃ are the same as the above.) One or more kinds. The method according to 1.