JP2010095467A - Method for continuously producing (meth)acrylate - Google Patents

Abstract

[PROBLEMS] In particular, when a high boiling point (meth) acrylate is continuously produced, it is easy to separate an organic layer and an aqueous layer after a neutralization / water washing step by a simple method, and a large amount of processing liquid can be obtained with a small apparatus. Providing a production method that can be saponified and has excellent final product quality.
(Meth) acrylic acid and alcohol are heated and stirred in the presence of an acid catalyst to produce (meth) acrylate, and the resulting organic solution and aqueous alkali solution containing (meth) acrylate are continuously added. A method for producing (meth) acrylate, which is supplied to an emulsifying disperser and subjected to saponification treatment.
[Selection] Figure 2

Description

The present invention relates to a method for producing (meth) acrylate, and more particularly to a method for producing (meth) acrylate suitable for a continuous production method, and belongs to the technical field of producing and using (meth) acrylate.
In the present specification, acrylate or methacrylate is represented as (meth) acrylate, acrylic acid or methacrylic acid is represented as (meth) acrylic acid, and acryloyl group or methacryloyl group is represented as (meth) acryloyl group.

  In general, (meth) acrylate includes a method of producing from (meth) acrylic acid and alcohol by esterification with an acid catalyst, and a method of producing from (meth) acrylate and alcohol by transesterification.

In the manufacturing method of (meth) acrylate, the continuous manufacturing method is examined for the purpose of improving productivity and reducing manufacturing cost.
Low-boiling point (meth) acrylates such as (meth) acrylate having one (meth) acryloyl group (hereinafter referred to as “monofunctional (meth) acrylate”) can be purified by distillation. -Easy to purify.
In contrast, high boiling point (meth) acrylates such as (meth) acrylate having two or more (meth) acryloyl groups (hereinafter referred to as “polyfunctional (meth) acrylate”) are difficult to purify by distillation operation. , It is difficult to continuously produce.

In addition, in the production of polyfunctional (meth) acrylate, in order to increase the ratio of (meth) acryloyl groups per molecule, the reaction is performed for a long time compared to the production of monofunctional (meth) acrylate, The reaction takes place at high temperatures. For this reason, the ratio of the side reaction product (hereinafter simply referred to as “byproduct”) is often higher than that of the monofunctional (meth) acrylate.
Among by-products, particularly emulsifying compounds have a bad influence on poor separation and quality in the purification process unless they are sufficiently removed by saponification (for example, Patent Document 1).
Therefore, even in the case of continuously producing a high boiling point (meth) acrylate, it is necessary to sufficiently remove the emulsifying compound in the by-product by saponification treatment, but the continuous treatment is difficult and continuous. There is no known technique for specifying the purification method.

Patent Document 2 discloses a method for producing (meth) acrylate using a continuous treatment facility using an extraction tower and a stationary tank in combination, and neutralization existing in the vicinity of the interface between the organic phase and the aqueous phase in both devices. There has been proposed a production method in which a by-product that promotes emulsification of a part of salt, polymer, sludge, etc. and promotes poor separation is separated and removed to prevent trouble in the next step.
However, although this production method can be applied to a system with relatively few by-products that promote emulsification, such as monofunctional (meth) acrylate, it has a high boiling point (meth) such as polyfunctional (meth) acrylate. Application to acrylate is difficult.
Further, in Patent Document 3, in the invention described in Patent Document 2, a 1 to 10 μm filter is further installed to remove a part of neutralized salt, polymer, and sludge which are insoluble components on the organic phase side. However, in this method, the management of the filter is complicated, and in a system with many by-products such as a method for producing a high-boiling point (meth) acrylate, It is not a practical method.

Further, Patent Document 4 proposes the separation of the organic phase and the aqueous phase in the neutralization / water washing step of the esterification reaction solution using a centrifuge instead of the stationary tank, but this method also includes a by-product. When a large amount of an emulsifying compound is contained, separation and purification are difficult, and the equipment cost is also expensive.
In Patent Document 4, as pointed out in the problem, in static separation using a stationary tank, the specific gravity difference between the organic phase and the aqueous phase, separation temperature, composition change, ease of emulsion formation, and mixing The time required for separation varies greatly depending on the stability (emulsification) of the droplets that can be made, and the actual apparatus requires a large stationary tank to absorb these variations.

JP 2007-1958 (Claims) JP 2003-226672 A (Claims) JP2003-231665A (Claims) Japanese Patent Laid-Open No. 10-045669 (Claims)

  In the case of continuously producing high-boiling point (meth) acrylates, the present inventors can easily separate the organic layer and the aqueous layer after the neutralization / water washing step by a simple method, In order to find a manufacturing method that can saponify the treatment liquid and excel in the quality of the final product, it has been intensively studied.

  In order to solve the above problems, the present inventors have found that a production method in which a reaction solution obtained by an esterification reaction is supplied to an emulsifying disperser and subjected to saponification is effective, and the present invention has been completed. did.

  According to the production method of the present inventor, it is easy to separate the organic layer and the aqueous layer after the neutralization / water washing step by a simple method of supplying the reaction liquid and the aqueous alkali solution to the emulsifying disperser, and a large amount with a small apparatus. This makes it possible to saponify the treatment liquid, and it is possible to produce a (meth) acrylate having excellent final product quality.

The present invention relates to a method for producing (meth) acrylate, in which an organic phase containing a reaction liquid obtained by an esterification reaction and an aqueous alkali solution are continuously supplied to an emulsifying disperser and subjected to saponification treatment.
Hereinafter, the present invention will be described in detail.

According to the production method of the present invention, various (meth) acrylates can be produced, but this is particularly effective for (meth) acrylates that are difficult to purify by distillation. In particular, it can be preferably applied to (meth) acrylates having a boiling point of 220 ° C. or higher.
Specific examples thereof include (meth) acrylates of alkylalkylene oxide adducts such as (meth) acrylate of alkylene oxide adducts of 2-ethylhexyl alcohol; (meth) acrylates and phenols of p-cumylphenol alkylene oxide adducts. (Meth) acrylates such as (meth) acrylates of alkylene oxide adducts and (meth) acrylates such as (meth) acrylates of nonylphenol alkylene oxide adducts; polycyclic alkyldi (such as tricyclodecanedimethylol di (meth) acrylate) (Meth) acrylate; ethylene glycol mono- or di (meth) acrylate, propylene glycol mono- or di (meth) acrylate, pentanediol mono- or di (meth) acrylate Mono- or di (meth) acrylates of dihydric alcohols such as mono- or di (meth) acrylates of benzoate and hexanediol; mono- or di (meth) acrylates of diethylene glycol, mono- or di (meth) acrylates of triethylene glycol, tetra Mono- or di (meth) acrylate of ethylene glycol, mono- or di (meth) acrylate of polyethylene glycol, mono- or di (meth) acrylate of dipropylene glycol, mono- or di (meth) acrylate of tripropylene glycol and mono-polypropylene glycol Or polyalkylene glycol mono- or di (meth) acrylate such as di (meth) acrylate; glycerin di- or tri (meth) acrylate and diglycerin di- or tri (meth) acrylate Di- or tri (meth) acrylates of phosphorus; di- or tri (meth) acrylates of alkylene oxide adducts of glycerins; mono- or di (meth) acrylates of bisphenol A alkylene oxide adducts and mono-of di (meth) acrylates and bisphenol F alkylene oxide adducts Or a mono or di (meth) acrylate of a bisphenol alkylene oxide adduct such as di (meth) acrylate; trimethylolpropane tri (meth) acrylate, ditrimethylolpropane tri (meth) acrylate, ditrimethylolpropane tetra (meth) acrylate, penta Erythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate and dipentaerythritol hex Poly (meth) acrylates such as sa (meth) acrylates; poly (meth) acrylates of alkylene oxide adducts of these polyols; di- or tri (meth) acrylates of isocyanuric acid alkylene oxide adducts; and polyester (meth) acrylates Is mentioned.

1. Esterification Reaction In the production method of the present invention, (meth) acrylate is first produced by heating and stirring (meth) acrylic acid and alcohol in the presence of an acid catalyst to carry out an esterification reaction.
Hereinafter, the esterification reaction will be described.

What is necessary is just to use what corresponds to above-mentioned (meth) acrylate as alcohol.
Specifically, an alkylene oxide adduct, an alkyl alkylene oxide adduct of 2-ethylhexyl alcohol; a phenol alkylene oxide adduct such as p-cumylphenol alkylene oxide adduct, phenol alkylene oxide adduct and nonylphenol alkylene oxide adduct; Polycyclic alkyl di (meth) acrylates such as tricyclodecane dimethylol; dihydric alcohols of ethylene glycol, propylene glycol, pentanediol and hexanediol; diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, tri Polyalkylene glycols such as propylene glycol and polypropylene glycol; glycerin and jigs Glycerins such as serine; alkylene oxide adducts of glycerol; bisphenol A alkylene oxide adducts and bisphenol F alkylene oxide adducts such as bisphenol alkylene oxide adducts; trimethylolpropane, ditrimethylolpropane, pentaerythritol, dipentaerythritol, etc. These polyols include alkylene oxide adducts of these polyols; isocyanuric acid alkylene oxide adducts; and polyester diols.
Examples of the alkylene oxide in the alkylene oxide adduct include ethylene oxide and propylene oxide. Further, the addition number of alkylene oxide is preferably 1 to 20.

(Meth) acrylic acid is acrylic acid or methacrylic acid, and is selected depending on whether the target ester is an acrylate or a methacrylate.
The amount of (meth) acrylic acid used is adjusted with respect to 1 mol of all hydroxyl groups of the alcohol so as to be the intended (meth) acrylate.

  Examples of the acid catalyst include mineral acids such as sulfuric acid, and sulfonic acids such as p-toluenesulfonic acid, methanesulfonic acid, and trifluoromethanesulfonic acid.

The esterification reaction may be carried out according to a conventional method.
The reaction temperature may be appropriately set according to the raw material to be used and the purpose, but is preferably 65 to 140 ° C, more preferably 75 to 120 ° C from the viewpoint of shortening the reaction time and preventing polymerization. By making reaction temperature 65 degreeC or more, esterification reaction can be performed rapidly and the fall of a yield can be prevented, On the other hand, (meth) acrylic acid or produced | generated by setting reaction temperature to 140 degrees C or less ( Thermal polymerization of (meth) acrylate can be prevented.
The pressure in the reaction may be normal pressure or reduced pressure. As described later, it is preferable to carry out the reaction under reduced pressure for the purpose of preventing thermal polymerization of (meth) acrylic acid or the generated (meth) acrylate.

In the esterification reaction, it is preferable to promote dehydration while azeotroping water produced in the esterification reaction with an organic solvent.
Examples of preferable organic solvents include aromatic hydrocarbons such as toluene, benzene and xylene, aliphatic hydrocarbons such as hexane and heptane, and ketones such as methyl ethyl ketone.
The amount of the organic solvent used is preferably 10 to 75% by weight, more preferably 15 to 55% by weight, based on the total amount of the alcohol and (meth) acrylic acid.

The esterification reaction is preferably performed at a low temperature (preferably 75 to 120 ° C.) under reduced pressure for the purpose of preventing thermal polymerization of (meth) acrylic acid or the generated (meth) acrylate. Moreover, it is preferable to perform esterification reaction in presence of oxygen.
For the same purpose, it is preferable to add a polymerization inhibitor to the reaction solution. Examples of the polymerization inhibitor include organic compounds and metal salts.
Examples of the organic compound include benzoquinone, hydroquinone, catechol, diphenylbenzoquinone, hydroquinone monomethyl ether, naphthoquinone, t-butylcatechol, t-butylphenol, dimethyl-t-butylphenol, t-butylcresol, dibutylhydroxytoluene and phenothiazine. It is done.
Examples of the metal salt include metal copper compounds such as cupric chloride and copper sulfate, and metal iron compounds such as ferrous sulfate.
The addition amount of the polymerization inhibitor is preferably 10 to 50000 ppm by weight, more preferably 100 to 10000 ppm, based on the amount of (meth) acrylic acid used as a raw material. By making it 100 ppm or more, the polymerization preventing effect can be made sufficient, and by making it 10000 ppm or less, coloring can be prevented or the curability of the product can be prevented from being lowered.
The degree of progress of the esterification reaction is monitored by monitoring the amount of water produced by the esterification reaction, that is, the amount of dehydration, analyzing the acid content concentration in the reaction solution, analyzing the composition of the product (meth) acrylate, Judgment is made by confirming whether the target composition is obtained.

2. Neutralization treatment step In the present invention, the reaction solution obtained by the esterification reaction is neutralized with an aqueous alkaline solution.
A neutralization process is a process performed in order to remove acid content, such as unreacted (meth) acrylic acid and an acid catalyst, in the said esterification reaction liquid.

  In the alkaline aqueous solution used in this step, examples of the alkaline component include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal salts such as sodium carbonate, and alkaline earth metals such as calcium hydroxide. It is done. Among these, alkali metal hydroxides are preferable because of high neutralization effect.

In the aqueous alkali solution used in the neutralization treatment, the amount of the alkali component is usually 1 time or more, preferably 1.0 to 1.6 times in molar ratio with respect to the acid content of the reaction solution. If this addition amount is less than 1 time in molar ratio with respect to the acid content of the reaction solution, neutralization of the acid content becomes insufficient, such being undesirable.
Moreover, it is preferable that the density | concentration of aqueous alkali solution is 1 to 25 weight%, More preferably, it is 3 to 25 weight%. By setting this concentration to 1% by weight or more, it is possible to prevent the amount of waste water after neutralization from increasing, and by setting it to 25% by weight or less, it is possible to prevent polymerization of (meth) acrylate.

The neutralization treatment is performed by supplying the reaction solution and the aqueous alkali solution to a tank-type apparatus or using a static mixer. As the reaction solution, a solution to which an organic solvent has been added in advance can be used for the purpose of adjusting specific gravity and the like.
In the case of continuous production, it is preferable to use a static mixer because the apparatus is compact.
What is necessary is just to set suitably stirring / mixing time in the case of processing with a tank type | mold apparatus according to the target (meth) acrylate, a production amount, etc., but 1 to 60 minutes are preferable.
Even when a static mixer is used, the supply conditions for the reaction solution and the aqueous alkaline solution may be appropriately set according to the target (meth) acrylate and the production amount, etc. The elements inside the static mixer as shown in FIG. There in the case of using a composed Kenics type in that arranged right element, a left element alternately in Reynolds number 100-10000, preferably the division number N = 2 ⁶ ~2 ^18.
The residence time is preferably 1 to 10 seconds, and the linear velocity is preferably 0.1 to 2 m / s.
As the shape of the static mixer, there are Hi-Mixer type (Toray) and SMV type (Sulzer) in addition to the Kenics type.

3. (Meth) acrylate production method In the present invention, an organic liquid and an aqueous alkali solution containing (meth) acrylate obtained by the esterification reaction are continuously supplied to an emulsifier-dispersing machine to perform a saponification treatment. It is a manufacturing method.
By using an emulsifier / disperser, for example, it is possible to saponify a large amount of processing liquid with a small apparatus as compared with a method using a conventional stirring tank or a method using an extractor.

The saponification treatment is a step performed for the purpose of removing the emulsifiable compound and facilitating the subsequent separation step, which cannot be removed in the neutralization step.
Here, the “organic liquid containing (meth) acrylate” includes the following embodiments.
1) Reaction liquid obtained by esterification reaction 2) Organic liquid obtained by further adding organic solvent to reaction liquid 3) 1) or 2) Washed with water and then separated to obtain organic phase 4) 1), The organic phase obtained by neutralizing the liquid 2) or 3) with an aqueous alkali solution and then separating it. In the following description, it is simply referred to as “organic liquid”.

  In the aqueous alkali solution used in this step, examples of the alkali component include the same as described above, and an alkali metal hydroxide is preferable because it has a high saponification effect.

In the alkaline aqueous solution used in the saponification treatment, the concentration of the alkali component is preferably 1 to 25% by weight, more preferably 10 to 25% by weight.
The amount of the alkaline aqueous solution used is preferably 0.2 to 4 times in molar ratio with respect to the amount of alkali used during the neutralization treatment, and 0.5 to 2 times in consideration of the size of the treatment tank and the amount of drainage. Is more preferable.
In this case, both treatments can be efficiently performed by using the same treatment agent as the neutralization treatment agent as the saponification treatment agent.

A preferred facility used in the present invention will be described based on the schematic diagram of FIG.
The emulsifier / disperser 1 includes a supply pipe 2 for supplying an organic liquid and a supply pipe 3 for supplying an alkaline aqueous solution. Pumps 2-2 and 3-2 are attached to the supply pipe 2 and 3 respectively.

Any emulsifying and dispersing machine may be used as long as it has a mixer portion for mixing and dispersing the organic liquid and the aqueous alkali solution.
Specific examples include a high-speed rotary centrifugal radiation type stirrer (disper mixer), a high-speed rotary shear type stirrer (homomixer), a colloid mill, a media type disperser, a high-pressure jet type emulsifying disperser, and an ultrasonic emulsifying disperser. .
As the emulsifying disperser, both a continuous emulsifying disperser and a batch emulsifying disperser can be used, but a continuous emulsifying disperser is preferable.
Emulsifying and dispersing machines are commercially available, and as a continuous type emulsifying and dispersing machine, trade name T.P. K. Pipeline homomixer, T.W. K. Homomic line flow, T.W. K. Examples include homomic line mills and the trade name Cavitron manufactured by Eurotex.
When using a batch type emulsifying disperser, it can be used in the present invention by continuously extracting the mixed solution after the dispersion treatment. The emulsifying disperser is separated as a settler part for the purpose of separating the mixed solution. Those having a device are preferred.
FIG. 2 is an example in which a stationary tank 5 is used as a separation device. The mixed liquid of the emulsifying disperser is supplied to the stationary tank 5 through the supply pipe 4, the aqueous phase is extracted from the supply pipe 6, and the organic separated by the supply pipe 7 is extracted and supplied to the next step. The
As a separation apparatus, a stationary tank, a centrifuge, and a coalescer (oil-water separator) are preferable.

  As the emulsifier / disperser, those in which the external heat exchangers 2-1 and 3-1 are attached to the supply pipes 2 and 3, respectively, are preferable. By controlling the organic liquid and alkaline aqueous solution supplied to the emulsifier / disperser to a certain temperature with an external heat exchanger, it becomes easy to adjust the degree of saponification, and further saponification is promoted by heating. be able to.

  As temperature of the organic liquid supplied to an emulsification disperser, and aqueous alkali solution, 25-60 degreeC is preferable.

The treatment in the emulsification disperser is operated until the emulsified component in the reaction product is almost removed.
As a specific standard, it is preferable to treat with an emulsifying disperser until the interfacial tension between the organic liquid and the aqueous phase at the outlet of the emulsifying disperser becomes 3 mN / m or more.
Examples of the method for measuring the interfacial tension include a method of sampling the treatment liquid from the outlet of the emulsifying disperser and measuring the interfacial tension using a surface tension meter.

In order to proceed with the saponification treatment and achieve such an interfacial tension, the organic liquid / alkaline water flow rate and liquid temperature, and the impeller cycle of the emulsifier / disperser are arbitrarily controlled.
These conditions in this case may be appropriately set according to the intended (meth) acrylate and reaction conditions.
The residence time of the organic liquid and the aqueous alkali solution is preferably 2 to 60 seconds, more preferably 5 to 30 seconds.
As a liquid temperature in an emulsification disperser, 10-70 degreeC is preferable, More preferably, it is 25-60 degreeC.
As an impeller period of an emulsification disperser, 2-30 m / s is preferable, More preferably, it is 10-25 m / s.

In the present invention, the neutralization step described above can be carried out using an emulsifier / disperser, that is, neutralization and saponification can be carried out simultaneously.
In this case, the concentration of the alkali component of the aqueous alkali solution may be the same as described above.
The amount of the alkaline aqueous solution used is preferably 1.2 to 5 times in molar ratio with respect to the acid content of the reaction solution.

4). Other treatments In the present invention, the above-described reaction solution, neutralization treatment solution or saponification treatment solution is preferably washed with water.
The water washing treatment can be performed on the reaction solution obtained by the esterification reaction, the organic layer after neutralization treatment or the organic layer after saponification treatment. The point at which the water washing treatment is performed may be appropriately selected according to the components to be used and the purpose. This washing treatment may be performed according to a conventional method. Specifically, a method of adding water to the reaction solution obtained by the esterification reaction, the organic layer after neutralization treatment or the organic layer after saponification treatment, stirring and mixing, and the like can be mentioned.

The water washing treatment may be carried out by a batch method or a continuous method.
In this case, the reaction liquid and water are supplied to a tank-type apparatus for processing, or processed using a static mixer. In the case of continuous production, it is preferable to use a static mixer because the apparatus is compact.

After the saponification treatment or, if necessary, the water washing treatment, the organic layer after separating the aqueous layer is removed from the organic solvent in a solvent removal tank.
The solvent removal treatment may be carried out in accordance with a conventional method, for example, a method in which the solvent removal tank is decompressed and the organic solvent is removed. What is necessary is just to set suitably as a vacuum degree of a solvent removal tank according to the raw material to be used and the objective, Preferably it is 0.5-50 kPa, and the method of increasing a pressure reduction degree gradually by the removal degree of a solvent is preferable.

In order to suppress thermal polymerization of (meth) acrylate, this solvent removal treatment is performed under reduced pressure by supplying oxygen or adding a polymerization inhibitor and maintaining the temperature at 80 ° C. or lower, for example. Is preferred.
If necessary, the organic solvent is removed from the organic phase in the solvent removal process in the solvent removal tank, a filter aid is supplied to the solvent removal tank, and the vertical horizontal filter type filter connected to the solvent removal tank is used. The reaction product can also be filtered by depositing a filter aid.

5. Preferred Embodiment The production method of the present invention is a method in which an organic liquid and an aqueous alkali solution are continuously supplied to an emulsifier / disperser for saponification, and the other steps are optional, specifically as described above. Street.
The production method of the present invention is particularly suitable for a continuous production method of (meth) acrylate. Specific embodiments thereof are shown in the following 1) to 5).
1) Reaction (continuous) → Neutralization (continuous) → Saponification (continuous) [Emulsification Disperser] →
2) Reaction (continuous) → Neutralization / Saponification (continuous) [Emulsification Disperser] →
3) Reaction (batch) → Neutralization (continuous) → Saponification (continuous) [Emulsification Disperser] →
4) Reaction (batch) → Neutralization / Saponification (continuous) [Emulsifier / Disperser] →
5) Reaction (batch) → Neutralization (batch) → Saponification (continuous) [Emulsification Disperser] →

In the embodiment of 1), the reaction liquid is continuously withdrawn from the reactor while performing the esterification reaction, the neutralization treatment is continuously carried out, and then the saponification treatment is carried out continuously using an emulsifying disperser. It is.
FIG. 3 schematically shows an example of the manufacturing equipment used in this embodiment.
FIG. 3 is an example in which the neutralization process is continuously performed using a static mixer.
After the esterification reaction is completed in the reactor 8, the reaction solution is continuously extracted and the reaction solution is supplied to the static mixer 11 through the supply pipe 9. At the same time, an alkaline aqueous solution is supplied from the supply pipe 10 to the static mixer 11.
After the neutralization treatment, the organic phase separated and supplied to the stationary tank 13 through the supply pipe 12 is supplied to the emulsification disperser 1. At the same time, the aqueous phase after neutralization is separated from the supply pipe 14.
In this case, it is preferable to provide a storage tank between the stationary tank 13 and the emulsification disperser 1 (before the pump 2-1) in order to easily cope with a change in the flow rate of the organic phase. By storing the separated organic phase in a storage tank once and supplying it to the emulsifying disperser 1, a preferable supply amount to the emulsifying disperser 1 can be maintained.

In the embodiment of 2), the reaction liquid is continuously withdrawn from the reactor while carrying out the esterification reaction, and the neutralization treatment and the saponification treatment are carried out continuously using an emulsifying disperser.
FIG. 4 shows a schematic diagram of an example of the manufacturing equipment used in this embodiment.
In FIG. 4, after the esterification reaction is completed in the reactor 8, it is continuously extracted, and the reaction liquid is supplied to the emulsification disperser 1 through the supply pipe 2. At the same time, the aqueous alkaline solution is supplied from the supply pipe 3 to the emulsification disperser 1.

In the embodiment of 3), after the esterification reaction is carried out in a batch system, the reaction solution is withdrawn and the neutralization treatment is continuously carried out, and then the saponification treatment is carried out continuously using an emulsifying disperser. .
Examples of manufacturing equipment that can be used in this embodiment include the equipment shown in FIG.

In the embodiment of 4), after the esterification reaction is carried out in a batch system, the reaction solution is withdrawn, and the neutralization treatment and the saponification treatment are carried out continuously using an emulsifying disperser.
As an example of manufacturing equipment that can be used in this embodiment, the equipment shown in FIG. 4 can be cited.

In the embodiment of 5), after the esterification reaction is carried out in a batch system, the reaction solution is taken out, the neutralization process is carried out in a batch system, and then the saponification process is carried out continuously using an emulsifying disperser. is there.
As an example of the manufacturing equipment that can be used in this embodiment, there can be mentioned the equipment shown in FIG. 3 in which a static mixer is replaced with a tank-type device.

  Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. In the following, “part” means part by weight.

○ Examples 1 to 3
A reactor was charged with 1000 parts of acrylic acid, 480 parts of dipentaerythritol (manufactured by Guangei Chemical Co., Ltd.), 24 parts of sulfuric acid, 2.5 parts of hydroquinone monomethyl ether (hereinafter referred to as MEHQ) and 900 parts of toluene, and a pressure of 400 Torr (absolute Pressure) and a reaction temperature of 90 ° C., and the reaction was conducted while removing condensed water. The reaction was continued until the conversion was 90 mol% or more based on the alcohol.
After completion of the reaction, 900 parts of toluene was added to the reaction solution, and a 20 wt% aqueous sodium hydroxide solution (hereinafter referred to as “20% caustic”) corresponding to an equimolar amount with respect to the diluted acid content was added with stirring. Then, neutralization treatment was carried out to remove excess acrylic acid and sulfuric acid catalyst, and then the organic phase separated was used as the treatment liquid.

The manufacturing apparatus shown in FIG. 2 was used. A stationary tank with an effective volume of 2 L is set at the outlet of the emulsifier disperser. A PL-SL type (maximum rotation speed 9,000 rpm, maximum peripheral speed about 21 m / s) manufactured by PRIMIX Co., Ltd. was used as the emulsifying disperser.
The organic phase and 20% caustic in proportions of 86.0% by weight and 14.0% by weight (0.64 times the amount of alkali used in the neutralization treatment), respectively, the residence time, impeller cycle and The test was performed at the feed temperature.

In any case, as a result of operating continuously for 3 hours, it was confirmed that a stable continuous treatment was possible without a separation interface rising due to poor separation in a stationary tank.
In addition, components such as polymer and sludge are not confirmed at the separation interface, and the separation interface is good.

○ Comparative Example 1
A treatment liquid was obtained in the same manner as in Example 1.
The obtained processing liquid was processed using the manufacturing apparatus shown in FIG. In the comparative example 1, it replaced with the emulsification disperser of Example 1, and implemented using the curl column [Sumitomo Plant Engineering Co., Ltd. curl column (10ft * Φ1inch)] which is a countercurrent extraction tower. Usually, the organic phase and the aqueous phase are separated at the upper and lower parts of the curl column, but for the purpose of further separation of the aqueous phase from the organic phase, the auxiliary tank 2L is additionally installed at the upper part of the curl column to conduct the test. did.
For the purpose of promoting saponification, the test was carried out by setting the number of rotations of the perforated plate installed in the curl column to an arbitrary number of rotations in which the aqueous phase was not accompanied by the organic phase.

In Comparative Example 1, since the organic phase and 20% caustic could not be separated at the same residence time in seconds as in the Examples, the residence time was changed to minutes, but separation was still poor (Comparative Example 1- 1-1-3).
In order to improve the separation, in the examples, the residence time is set to a residence time (73.5 minutes, 90.8 minutes) that is about 100 times or more the minimum processing conditions (residence time: 39.1 seconds). For the first time, the separation was good (Comparative Examples 1-4 to 1-5).

Example 4
Using the reaction apparatus shown in FIG. 3, acrylate was continuously produced.
To the reactor, a mixture of 1000 parts acrylic acid, 450 parts dipentaerythritol (manufactured by Guangei Chemical Co., Ltd.), 90 parts methanesulfonic acid, 2.2 parts MEHQ, and 660 parts toluene was continuously fed. The mixture was heated and stirred at a pressure of 340 Torr (absolute pressure) and a reaction temperature of 90 ° C., and continuously reacted while removing condensed water. The residence time in each reactor was adjusted so that the conversion rate was 90 mol% based on the alcohol, and a reaction solution was continuously obtained.
To the reaction solution, 820 parts of toluene was added, 20% caustic equivalent to an equimolar amount with respect to the diluted acid content was added to a static mixer (Reynolds number 500, number of divisions N = 2 ¹² ), and a stationary tank. After mixing and separating, excess acrylic acid and sulfuric acid catalyst were removed, and then the organic phase was separated and used as the treatment liquid.
In FIG. 3, a PL-SL type manufactured by Primix Co., Ltd. was used as an emulsifying disperser as in Example 1, and a centrifuge was installed at the outlet of the emulsifying disperser. As the centrifuge, a continuous centrifuge V-2 type (centrifugal force 2300G) manufactured by CINC JAPAN was used.
The organic phase and 20% caustic were 85.0% by weight and 15.0% by weight (0.63 times the amount of alkali used in the neutralization treatment), respectively, and the residence time, impeller cycle and The test was performed at the feed temperature.

In any case, as a result of operating continuously for 3 hours, it was confirmed that a stable continuous treatment was possible without a separation interface rising due to poor separation in a stationary tank.
In addition, components such as polymer and sludge are not confirmed at the separation interface, and the separation interface is good.

  The production method of the present invention can be used for the production of (meth) acrylates.

FIG. 1 is a conceptual diagram showing an example of a static mixer used in the present invention. FIG. 2 is a conceptual diagram showing an example of an emulsifying disperser used in the present invention. FIG. 3 is a conceptual diagram showing an example of a continuous esterification reaction apparatus. FIG. 4 is a conceptual diagram showing an example of a continuous esterification reaction apparatus. FIG. 5 shows a conceptual diagram of the purification apparatus used in Comparative Example 1.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Emulsification disperser 2 Organic liquid supply pipe 3 Alkaline aqueous solution supply pipe 5 Stationary tank 8 Reactor 11 Static mixer 14 Carl column

Claims (8)

(Meth) acrylic acid and alcohol are heated and stirred in the presence of an acid catalyst to produce (meth) acrylate, and the resulting (meth) acrylate-containing organic liquid and alkaline aqueous solution are continuously added to an emulsifying disperser. A method for producing (meth) acrylate which is supplied and subjected to saponification treatment. (Meth) acrylic acid and alcohol are heated and stirred in the presence of an acid catalyst to produce (meth) acrylate, and the resulting (meth) acrylate-containing organic liquid and alkaline aqueous solution are continuously added to an emulsifying disperser. The method for producing a (meth) acrylate according to claim 1, wherein the neutralization treatment and the saponification treatment are carried out. The method for producing a (meth) acrylate according to claim 1 or 2, wherein an impeller period of the emulsification disperser is 10 to 25 m / s. The method for producing a (meth) acrylate according to any one of claims 1 to 3, wherein the saponification treatment is performed so that the organic-water phase interfacial tension at the outlet of the emulsifying disperser is 3 mN / m or more. The method for producing a (meth) acrylate according to any one of claims 1 to 4, wherein the emulsification disperser is provided with a separation device for separating the organic phase and the aqueous phase. The method for producing (meth) acrylate according to claim 5, wherein the separation device is a stationary tank, a centrifuge, or a coalescer. The (meth) acrylate obtained by continuously producing (meth) acrylate by heating and stirring (meth) acrylic acid and alcohol in the presence of an acid catalyst is used. The manufacturing method of the (meth) acrylate as described in 2. The (meth) acrylate obtained is a compound having a boiling point of 220 ° C or higher. The method for producing (meth) acrylate according to any one of claims 1 to 7.

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