JP2007001915A - Acrylate or methacrylate production apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an acrylate or methacrylate production apparatus which can accurately detect an acrylate or methacrylate reaction conversion without causing composition irregularity and overreaction, and to provide an acrylate or methacrylate production method. <P>SOLUTION: This acrylate or methacrylate production apparatus has a reactor 3 equipped with a heater 5 and a fractionating tower 9, a condenser 11 connected to the overhead of the fractionating tower 9, a separator 13 for layer-separating a distillate concentrated with the condenser 11 into an azeotropic solvent layer and a reaction by-product layer, a piping 24 for returning the azeotropic solvent layer-separated with the separator 13 to the overhead side of the fractionating tower 9, and a recovery tank 15 which receives the whole amount of the reaction by-products separated from the separator 13 and has a load cell 17 for measuring the whole mass thereof. When the acrylate or methacrylate is produced, the whole mass of the reaction by-products in the recovery tank 15 is measured with the load cell 17 to determine a reaction conversion or a reaction finish time. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention uses an apparatus for producing acrylic acid or methacrylic acid (hereinafter abbreviated as (meth) acrylic acid), a method for determining a reaction conversion rate in a process for producing (meth) acrylic acid ester, and the method for determining the same. It relates to a method for producing a (meth) acrylic acid ester for determining the reaction end time.

  In general, industrial production methods of (meth) acrylic acid esters include (1) a method of dehydrating acrylic acid or methacrylic acid and alcohol by a condensation reaction using a strong acid as a catalyst, (2) methyl (meth) acrylate, etc. There are two production methods of transesterifying the alkoxy group of the ester with the alkoxy group of another alcohol in the presence of a catalyst (see Patent Document 1). Examples of the catalyst used in the production method (2) include a titanate catalyst, a tin catalyst, and LiOH.

  When manufacturing (meth) acrylic acid ester by these methods, in order to determine the completion | finish time of reaction, reaction conversion rate is detected and the manufacturing process is managed. As a method for detecting the reaction conversion rate, a change in the distillate component is detected by measuring the temperature at the top of the rectifying column attached to the reactor, or the reaction liquid is sampled from the reactor and its composition is determined. Conventionally, a measuring method or the like is used.

  In the production of (meth) acrylic acid ester, when (meth) acrylic acid ester is produced, water is used as a by-product in the case of (1) dehydration reaction, and in the case of (2) transesterification reaction. Alcohol such as methanol is produced. Since the reactions (1) and (2) are both equilibrium reactions, it is necessary to remove these by-products from the reaction system in order to advance the reaction. Usually, the by-product is azeotroped with the azeotropic solvent and removed from the reaction system.

  The reaction conversion rate of (meth) acrylic acid ester can also be detected by measuring the amount of by-products removed outside the reaction system. Therefore, after separating condensed water and alcohol removed outside the system from the azeotropic solvent with a separator, etc., these flow rates that flow out from the separator through the outflow pipe are attached to the rotameter or integrated flow rate. The reaction conversion rate is also estimated by indirectly measuring with a flow meter such as a meter.

However, in the case of using the method for estimating the total distillate amount by such an indirect flow rate measurement method, since the total distillate amount is not actually measured, a measurement error is included.
JP 2001-48831 A (paragraph number (0002))

  As described above, all the conventional methods for detecting the reaction conversion rate have the following problems.

  The method of measuring the column top temperature of the rectifying column has a large fluctuation in the composition control range, and further has a problem that the column top temperature cannot quickly follow the change in the composition of the reaction solution. In the method of directly measuring the composition of the reaction solution, it takes time to analyze the composition, and there is a risk that the reaction proceeds during that time and exceeds the target conversion rate, resulting in an overreaction. In addition, after condensing condensed water and by-product alcohol together with the azeotropic solvent, separating them with a separator, and measuring the separated condensed water and by-product alcohol with an integrating flow meter, a flow meter is arranged. The measurement error due to the pipe diameter of the installed outflow pipe and the flow rate of water or alcohol is large, and it is difficult to accurately detect the reaction conversion rate.

  In the production of the (meth) acrylic acid ester described above, the present inventor used an azeotropic solvent that is incompatible with the reaction by-product water or alcohol and azeotropes with these to coexist outside the reaction system together with the solvent. After separating the reaction by-product removed by boiling from the azeotropic solvent, it was learned that the reaction conversion rate could be accurately detected by directly measuring the total mass or volume of the reaction by-product, and the present invention was completed. It was.

  The present invention for solving the above problems is described below.

  [1] A reactor equipped with a means for heating the reaction solution and a rectifying column, a condenser connected to the top of the rectifying column and condensing the distilled components of the rectifying column, and condensed by the condenser The separated components are separated into an azeotropic solvent and a reaction by-product, a pipe for refluxing the azeotropic solvent separated by the separator to the top of the rectifying column, and the separated layer. An acrylate ester or methacrylic acid ester production apparatus having a recovery tank having means for receiving the total amount of reaction by-products and directly measuring the total mass or total volume thereof.

  [2] A method for determining the reaction conversion rate in the step of producing an acrylic ester or methacrylic ester by condensing acrylic acid or methacrylic acid with an alcohol, which is insoluble or hardly soluble in water and coexists with water. Acrylic acid or methacrylic acid and alcohol are condensed in the presence of a boiling azeotropic solvent, and water produced as a by-product of the condensation is azeotropically distilled together with the azeotropic solvent to azeotrope with the azeotropically distilled water. A method for determining a reaction conversion rate by detecting a reaction conversion rate by separating a layer after condensing a solvent and measuring a total mass or a total volume of condensed water.

  [3] The method for determining the reaction conversion rate according to [2], wherein the azeotropic solvent is toluene.

  [4] A method for producing an acrylic ester or methacrylic ester, which produces an acrylic ester or methacrylic ester by condensing acrylic acid or methacrylic acid with an alcohol, which is insoluble or hardly soluble in water. In the presence of an azeotropic solvent that azeotropes with water, acrylic acid or methacrylic acid and alcohol are condensed and water by-produced by condensation is distilled off azeotropically with the azeotropic solvent. A method for producing an acrylate ester or a methacrylic ester, wherein the layer is separated after condensing with an azeotropic solvent, and the reaction completion time is determined by measuring the total mass or total volume of the condensed and separated water.

  [5] The method for producing an acrylic ester or methacrylic ester according to [4], wherein the azeotropic solvent is toluene.

  [6] A method for determining a reaction conversion rate in a process of producing another type of acrylic acid ester or methacrylic acid ester by transesterifying a raw material acrylic acid ester or methacrylic acid ester with a raw material alcohol, the raw material acrylic acid ester or Raw material acrylic acid ester or methacrylic acid ester and raw material in the presence of an azeotropic solvent which is insoluble or hardly soluble in by-product alcohol by-produced by transesterification of methacrylic acid ester and raw material alcohol and azeotropes with by-product alcohol Transesterify with alcohol and distill off the by-product alcohol by azeotropic distillation with the azeotropic solvent. Condensation of the by-produced alcohol and the azeotropic solvent distilled off by azeotropic distillation separates the layers, and the total mass of the by-product alcohol or A method for determining the reaction conversion rate by detecting the reaction conversion rate by measuring the total volume.

  [7] The method for determining a reaction conversion rate according to [6], wherein the acrylic ester or methacrylic ester is methyl acrylate or methyl methacrylate, and the azeotropic solvent is n-hexane.

  [8] A method for producing an acrylic ester or methacrylic ester, which produces another type of acrylic ester or methacrylic ester by transesterifying a raw material acrylic ester or methacrylic ester with a raw material alcohol, the raw material acrylic acid Raw material acrylic acid ester or methacrylic acid ester in the presence of an azeotropic solvent that is insoluble or hardly soluble in by-product alcohol by-produced by transesterification of ester or methacrylic acid ester with raw material alcohol and azeotropes with by-product alcohol And the raw material alcohol are transesterified, and the by-product alcohol is azeotropically distilled together with the azeotropic solvent, and the by-product alcohol and the azeotropic solvent distilled off by azeotropic distillation are condensed and separated into layers. An acrylic that determines the reaction end time by measuring mass or total volume. Method for producing esters or methacrylic acid esters.

  [9] The method for producing an acrylic ester or methacrylic ester according to [8], wherein the acrylic ester or methacrylic ester is methyl acrylate or methyl methacrylate, and the azeotropic solvent is n-hexane.

  According to the present invention, by directly measuring the total mass or total volume of water or alcohol produced as a by-product with the formation of (meth) acrylic acid ester, overreaction occurs or the composition varies from production lot to production lot. The reaction conversion rate can be detected accurately without determining the reaction end time.

  The present invention will be described below with reference to FIG.

  In FIG. 1, 1 is a manufacturing apparatus and 3 is a reactor. The reactor 3 is formed in a substantially cylindrical shape with both ends closed. A heater 5 is attached to the lower side of the peripheral wall 3a of the reactor 3 and the outer surface of the lower wall 3b. Furthermore, a cylindrical rectifying column 9 is attached to the reactor 3 through the upper wall 3c.

  The raw material (meth) acrylic acid, alcohol, catalyst, and azeotropic solvent toluene are injected into the reactor 3. The reaction liquid 6 composed of these components is heated by the heater 5 while being stirred by a stirrer 7 attached to the reactor 3.

  (Meth) acrylic acid and alcohol are dehydrated and condensed by being heated in the presence of a catalyst in the reactor 3 to produce a (meth) acrylic acid ester. Water produced as a by-product of the condensation reaction of (meth) acrylic acid and alcohol is azeotroped with toluene, which is an azeotropic solvent, and rises while being rectified in the rectifying column 9, and is distilled from the top of the rectifying column 9. The

  An azeotropic gas (water and toluene) distilled from the top of the rectifying column 9 is sent to the condenser 11 through the pipe 20 and condensed in the condenser 11 to become a liquid. The mixed liquid of water and toluene is sent from the condenser 11 to the separator 13 through the pipe 22. Since water and toluene are hardly soluble to each other, they are separated into two layers in the separator 13.

  Toluene separated into the upper layer 30 by the separator 13 is taken out from the separator 13 through a pipe 26 provided with a flow meter 24, returned to the top of the rectifying column 9, and refluxed in the rectifying column 9. .

  On the other hand, the lower layer 32 (water) separated in the separator 13 is taken out from the bottom surface of the separator 13 through the pipe 28 and collected in the collection tank 15. The recovery tank 15 includes a load cell 17 and can directly measure the total mass of the condensed water 19 recovered in the recovery tank 15. By directly measuring the total mass of the condensed water 19, the reaction conversion rate of the condensation reaction or the reaction end time can be determined.

  In addition, in FIG. 1, although the case where toluene was used as an azeotropic solvent of by-product water was shown, the solvent which is insoluble or hardly soluble in water and forms an azeotrope with water, for example, benzene, xylene , Cyclohexane, n-hexane, n-heptane, trichloroethane, tetrachloroethylene, methyl chloroform, diisopropyl ether, and the like can be used instead of toluene.

  1 shows a case where the recovery tank 15 includes a load cell 17, but the recovery tank 15 is provided with a liquid level gauge such as a differential pressure type liquid level gauge instead of the load cell 17 or together with the load cell 17. The total volume of the water recovered in the recovery tank 15 may be measured.

  Furthermore, although FIG. 1 demonstrated the case where (meth) acrylic acid ester was manufactured by condensation reaction of (meth) acrylic acid and alcohol, (meth) acrylic acid ester can also be manufactured by transesterification.

  For example, when transesterification is performed using methyl (meth) acrylate and alcohol, n-hexane can be used as an azeotropic solvent. In this case, the distilled methanol and n-hexane are slightly soluble in each other, but if the mixture of methanol and n-hexane is cooled to 10 ° C. or lower, they are separated from each other. The present invention can also be applied to.

  Examples of azeotropic solvents that can be used when (meth) acrylic acid esters are produced by transesterification include hydrocarbon compounds such as n-pentane, n-hexane, isohexane, neohexane, n-heptane, isoheptane, and n-octane. Is exemplified. N-Hexane is preferable from the viewpoint of the boiling point close to methanol and the viewpoint of separability during cooling.

  The esterification reaction to which the present invention is applied is applied to the production of (meth) acrylic acid ester having a molecular weight of about 140 to 50000, but is not limited thereto.

  Examples of the (meth) acrylic acid ester that can be produced using the present invention include (meth) acrylic acid ester of alkylene oxide-modified phenol, (meth) acrylic acid ester of alkylene oxide-modified nonylphenol, (poly) alkylene glycol ( (Meth) acrylic acid ethyl ester, alkylene oxide modified bisphenol A (meth) acrylic acid ester, alkylene oxide modified p-cumylphenol (meth) acrylic acid ester, alkylene oxide 2-ethylhexyl (meth) acrylic acid ester, alkylene oxide (Meth) acrylic acid ester of modified bisphenol F, acrylic acid ester of tricyclodecane dimethylol, alkylene oxide modified (di) glycerin acrylic acid ester, (di) penta (Meth) acrylic acid ester of (meth) acrylic acid ester of lithitol, (meth) acrylic acid ester of (di) trimethylolpropane, (meth) acrylic acid ester of alkylene oxide modified (di) trimethylolpropane, (meth) acrylic of alkylene oxide modified pentaerythritol Examples include acid esters, polyester acrylates, and epoxy acrylates.

Example 1
Using the production apparatus 1 shown in FIG. 1, dipentaerythritol penta / hexaacrylate (penta / hexa = 25/75) was produced by a condensation reaction of acrylic acid and dipentaerythritol. Toluene was used as the azeotropic solvent, and sulfuric acid was added as a catalyst.

  The total mass of the condensed water distilled out by the load cell 17 attached to the recovery tank 15 was constantly measured, and the reaction was stopped when the mass of the condensed water reached a predetermined value. As a result, the reaction conversion rate (oxidation standard) was 91.7-92.7% (11 batches, average value 92.2%), and the fluctuation width of the conversion rate was 1.0%.

Comparative Example 1
In the same manner as in Example 1, dipentaerythritol penta / hexaacrylate (penta / hexa = 25/75) was produced.

  The reaction solution in the reactor 3 was collected and the acid value was measured, and the reaction was stopped when the acid value reached a predetermined value. As a result, the reaction conversion rate (oxidation standard) was 90.7 to 93.4% (25 batches, average value 91.4%), and the fluctuation width of the conversion rate was 2.7%.

Example 2
Using the production apparatus 1 shown in FIG. 1, dipentaerythritol penta / hexaacrylate (penta / hexa = 40/60) was produced by a condensation reaction of acrylic acid and dipentaerythritol. Toluene was used as the azeotropic solvent, and paratoluenesulfonic acid was added as a catalyst.

  The total mass of the condensed water distilled out by the load cell 17 attached to the recovery tank 15 was constantly measured, and the reaction was stopped when the mass of the condensed water reached a predetermined value. As a result, the reaction conversion rate (oxidation standard) was 87.5 to 88.3% (10 batches, average value 87.9%), and the fluctuation width of the conversion rate was 0.8%.

Comparative Example 2
In the same manner as in Example 2, dipentaerythritol penta / hexaacrylate (penta / hexa = 40/60) was produced.

  The tower top temperature of the rectifying column 9 attached to the reactor 3 was constantly measured, and the reaction was stopped when the tower top temperature reached a predetermined value. As a result, the reaction conversion rate (oxidation standard) was 85.1 to 89.0% (20 batches, average value 86.6%), and the fluctuation width of the conversion rate was 3.9%.

Comparative Example 3
In the same manner as in Example 2, dipentaerythritol penta / hexaacrylate (penta / hexa = 40/60) was produced.

  The reaction solution in the reactor 3 was collected and the acid value was measured, and the reaction was stopped when the acid value reached a predetermined value. As a result, the reaction conversion rate (oxidation standard) was 85.4 to 88.7% (24 batches, average value 86.9%), and the fluctuation width of the conversion rate was 3.3%.

It is the schematic which shows an example of the manufacturing apparatus of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Manufacturing apparatus 3 Reactor 3a Perimeter wall 3b Lower wall 3c Upper wall 5 Heater 6 Reaction liquid 7 Stirrer 9 Rectifying tower 11 Condenser 13 Separator 15 Recovery tank 17 Load cell 19 Condensed water 20, 22, 26, 28 Piping 24 Flow meter 30 Upper layer 32 Lower layer

Claims (9)

A reactor equipped with means for heating the reaction solution and a rectifying column; a condenser connected to the top of the rectifying column to condense the distillation components of the rectifying column; and a distillate condensed by the condenser A separator for separating the components into an azeotropic solvent and a reaction by-product, a pipe for refluxing the azeotropic solvent separated by the separator to the top of the rectifying column, and a reaction by-layer separated by the separator An acrylic ester or methacrylic ester production apparatus having a recovery tank that has means for receiving the total amount of living organisms and directly measuring the total mass or total volume thereof. A method for determining a reaction conversion rate in a process of producing an acrylic ester or methacrylic ester by condensing acrylic acid or methacrylic acid and an alcohol, wherein the reaction conversion rate is insoluble or hardly soluble in water and azeotropes with water. In the presence of a boiling solvent, acrylic acid or methacrylic acid and alcohol are condensed and water by-produced by condensation is distilled off azeotropically with the azeotropic solvent, and azeotropically distilled water and azeotropic solvent are removed. A method for determining the reaction conversion rate by detecting the reaction conversion rate by measuring the total mass or the total volume of the condensed and separated water after condensing. The method for determining the reaction conversion rate according to claim 2, wherein the azeotropic solvent is toluene. An acrylic ester or methacrylic ester production method for producing an acrylic ester or methacrylic ester by condensing acrylic acid or methacrylic acid and an alcohol, which is insoluble or hardly soluble in water and azeotropes with water In the presence of an azeotropic solvent, acrylic acid or methacrylic acid and an alcohol are condensed, and water by-produced by the condensation is azeotropically distilled together with the azeotropic solvent. And then separating the layers, and measuring the total mass or total volume of the condensed and separated water to determine the reaction end time, and a method for producing an acrylic ester or methacrylic ester. The method for producing an acrylic ester or methacrylic ester according to claim 4, wherein the azeotropic solvent is toluene. A method for determining a reaction conversion rate in a process of producing another type of acrylic acid ester or methacrylic acid ester by transesterifying a raw material acrylic acid ester or methacrylic acid ester with a raw material alcohol, the raw material acrylic acid ester or methacrylic acid ester In the presence of an azeotropic solvent that is insoluble or hardly soluble in by-product alcohol by-produced by transesterification with raw material alcohol and azeotropes with by-product alcohol, raw acrylic ester or methacrylic ester and raw alcohol Transesterify and distill off the by-product alcohol azeotropically with the azeotropic solvent. Condensation of the azeotropic solvent by-produced by distillation and the azeotropic solvent, and then separate the layers. A method for determining the reaction conversion rate by detecting the reaction conversion rate by measuring. The method for determining the reaction conversion rate according to claim 6, wherein the acrylate or methacrylate is methyl acrylate or methyl methacrylate, and the azeotropic solvent is n-hexane. A method for producing an acrylic ester or methacrylic ester, wherein a raw material acrylic ester or methacrylic ester and a raw material alcohol are transesterified to produce another type of acrylic ester or methacrylic ester. Raw material acrylic acid ester or methacrylic acid ester and raw material alcohol in the presence of an azeotropic solvent that is insoluble or hardly soluble in by-product alcohol by-produced by transesterification between acid ester and raw material alcohol and azeotropes with by-product alcohol And the by-product alcohol together with the azeotropic solvent and distilled off, and the azeotropically distilled by-product alcohol and the azeotropic solvent are condensed and separated into layers. Acrylic acid which determines the reaction end time by measuring the volume Le or method for producing methacrylic acid esters. The method for producing an acrylic ester or methacrylic ester according to claim 8, wherein the acrylic ester or methacrylic ester is methyl acrylate or methyl methacrylate, and the azeotropic solvent is n-hexane.

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