JP5999342B2 - Method for producing glycidyl methacrylate - Google Patents

Description

  The present invention relates to a method for synthesizing glycidyl methacrylate (hereinafter referred to as GMA) from methacrylic acid (hereinafter referred to as MAA) and an alkali metal salt of MAA obtained from an alkali metal compound and epichlorohydrin (hereinafter referred to as EpCH). . GMA is useful as a raw material for weather-resistant paints and various resins.

Methacrylic acid esters such as GMA are frequently polymerized due to factors such as heat during the manufacturing process, storage and transportation, and may cause clogging troubles in piping and strainers. Therefore, in producing GMA, phenols such as p-methoxyphenol, bisphenols such as 2,2′-methylene-bis (4-methyl-6-tert-butylphenol), 4-hydroxy-2,2 In general, N-oxyl compounds such as 1,6,6-tetramethylpiperidine-1-oxyl, phenothiazine and the like are added to prevent polymerization.

For example, JP-A-55-17307 describes the use of p-methoxyphenol as a polymerization inhibitor when producing GMA, and JP-A 2011-46626 describes a polymerization inhibitor when producing glycidyl acrylate. Examples thereof include alkylphenols and N-oxyl compounds. Japanese Patent Application Laid-Open No. 2-193944 discloses a method for inhibiting polymerization of (meth) acrylic acid ester using a phenothiazine compound and a quinone compound. Japanese Patent Application Laid-Open No. 2002-338611 describes a method for producing a low-coloring curable composition using a phenol compound.

Among these, N-oxyl compounds such as 4-hydroxy-2,2,6,6, -tetramethylpiperidine-1-oxyl and phenothiazine are known to exhibit a higher polymerization inhibiting ability than phenols and bisphenols. However, it may cause coloring when mixed into a product, or depending on the use of GMA, it is necessary to avoid mixing nitrogen atoms derived from a polymerization inhibitor, and the usage method and usage amount may be limited.
On the other hand, bisphenol-based polymerization inhibitors have favorable characteristics as polymerization inhibitors used from the synthesis stage because they have a low vapor pressure and are hardly mixed into products and have no coloring property.
However, even when these bisphenol-based polymerization inhibitors are added, depending on the reaction conditions, a GMA polymer may be generated during the synthesis, which hinders stable operation production. From such a background, the appearance of a GMA production method that does not generate a polymer during synthesis is strongly desired.

JP-A-55-17307 JP 2011-46626 A Japanese Patent Laid-Open No. 2-193944 JP 2002-338611 A

An object of the present invention is to provide a method for producing GMA that solves the above-described problems in the prior art and suppresses the formation of a polymer.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that a polymerization inhibitor having a bisphenolic hydroxyl group in the molecule such as 2,2′-methylenebis- (6-tert-butyl-4-methylphenol). Discovered that during the reaction of synthesizing GMA from the alkali metal salt of MAA and EpCH, it deteriorated in the presence of a quaternary ammonium salt catalyst and lost its ability to inhibit polymerization.
Accordingly, the present inventors can suppress the generation of a polymer during synthesis by continuously adding a bisphenol polymerization inhibitor during the synthesis reaction and keeping the polymerization inhibitor concentration in the system at a certain level or higher. As a result of intensive studies, the inventors have found a method for adding a polymerization inhibitor suitable for the purpose and have completed the present invention.

That is, the present invention includes the following steps (1) and (2):
Step (1): A step of reacting MAA with an alkali metal compound in the presence of EpCH to synthesize an alkali metal salt of MAA.
Step (2): A quaternary ammonium salt catalyst is mixed with the reaction product solution obtained in Step (1), and a bisphenol polymerization inhibitor is mixed continuously or intermittently to obtain an alkali metal salt of MAA. A step of synthesizing GMA by esterification of EpCH with EpCH,
Wherein the concentration of the bisphenol polymerization inhibitor in the reaction solution is 100 ppm or more during the period from the start of the esterification reaction to the end of the esterification reaction in step (2), It is a manufacturing method of GMA.

According to the production method of the present invention, the production of a polymer during GMA synthesis is suppressed, and stable and economical production activities are possible.

Details of the method for producing GMA of the present invention will be described below. The method for producing the GMA of the present invention includes:
Step (1) A step of reacting MAA and an alkali metal compound in a composition comprising EpCH, MAA and an alkali metal compound to synthesize an alkali metal salt of MAA,
Step (2) A step of synthesizing GMA by esterifying an alkali metal salt of MAA and EpCH, with respect to the reaction product solution containing the alkali metal salt of MAA and EpCH obtained in the step (1). A step of mixing a quaternary ammonium salt catalyst and continuously or intermittently mixing a bisphenol polymerization inhibitor;
It is characterized by comprising.

In the step (1), a method for preparing a composition containing EpCH, MAA and an alkali metal compound is not particularly limited. The alkali metal compound may be added in the presence of EpCH and MAA, and conversely, MAA may be added in the presence of EpCH and the alkali metal compound. EpCH acts as a reaction solvent in step (1).

  In the step (1), the reaction temperature and pressure at the time of synthesizing an alkali metal salt of MAA by reacting MAA with an alkali metal compound are not particularly limited, and can be carried out by a known method.

  The amount of EpCH to be reacted with the alkali metal salt of MAA is 1 to 10 times mol of the alkali metal salt of MAA, preferably 3 to 8 times mol exceeding the amount of reaction with the alkali metal salt of MAA. When there is little EpCH, a by-product will increase and GMA yield will fall, and when too much, pot efficiency will fall and it is uneconomical.

The alkali metal compound is not particularly limited, and examples thereof include sodium compounds such as sodium hydroxide, sodium carbonate, sodium hydrogen carbonate and sodium phosphate, and potassium compounds such as potassium hydroxide, potassium carbonate and potassium hydrogen carbonate. The alkali metal compound is used in excess of MAA, and the amount used is 1 to 10 times equivalent, preferably 1 to 2 times equivalent to MAA. This step of converting MAA into an alkali metal salt may be performed in the absence of a solvent, but a solvent or a dispersion medium (hereinafter referred to as a medium) may be used, and considering the next step, it is preferably performed in the presence of EpCH.

  In the step (1), a polymerization inhibitor may be contained in the composition containing EpCH, MAA and an alkali metal compound. By containing the polymerization inhibitor, there is an effect of mainly suppressing the polymerization reaction of MAA. As the polymerization inhibitor, a bisphenol polymerization inhibitor (A1) can be used because it has no colorability and has a low vapor pressure and a low possibility of being mixed into a product.

The bisphenol-based polymerization inhibitor (A1) may be mixed at any time in a solid state such as powder or pellets. However, since the operation becomes complicated, it is preferable to continuously mix in the system as a solution. The solvent used in that case is not particularly limited, except for those that inhibit the reaction. The solvent is preferably EpCH or GMA in view of subsequent operations.

When the bisphenol polymerization inhibitor (A1) is dissolved in the solvent and mixed, the concentration of the bisphenol polymerization inhibitor in the solution is preferably 1 to 50 wt%, more preferably about 5 to 30 wt%. When the concentration is less than 1 wt%, the amount of the solvent increases, which leads to a decrease in reaction temperature and a decrease in production efficiency. If the concentration exceeds 50 wt%, it may not be sufficiently dissolved in the solvent from the viewpoint of solubility, which is not preferable.

As the bisphenol polymerization inhibitor (A1), specifically, 2,2′-methylene-bis (4-methyl-6-tert-butylphenol) (for example, “ANTAGE W-400”, manufactured by Kawaguchi Chemical Industry Co., Ltd.) 2,2′-methylene-bis (4-ethyl-6-tert-butylphenol) (for example, “ANTAGE W-500”, manufactured by Kawaguchi Chemical Co., Ltd.), 4,4-butylidene-bis- (3-methyl- 6-tert-butylphenol) (for example, “Adekastab AO40”, manufactured by ADEKA), tri-ethylene glycol-bis-3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate (for example, “Adekastab AO70 ", manufactured by ADEKA), 3,9-bis [1,1-di-methyl-2- {β- (3-tert-butyl-4-hydroxy) Roxy-5-methylphenyl) propionyloxy} ethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane (for example, “Adeka Stab AO80”, manufactured by ADEKA), N, N′-bis- 3- (3 ′, 5′-di-tert-butyl-4-hydroxyphenyl) propionylhexamethylenediamine (for example, “IRGANOX 1098”, manufactured by BASF Japan Ltd.) can be mentioned. As the bisphenol-based polymerization inhibitor (A1), at least one selected from the above compounds may be used, or a single or a combination of two or more may be used.
Among these, 2,2′-methylene-bis (4-methyl-6-tert-butylphenol) (Antage W-400) and 2,2′-methylene-bis (4-ethyl-6-tert-butylphenol) ( Antage W-500) is particularly preferred.

In the step (1), there is no particular limitation on the timing of mixing the bisphenol polymerization inhibitor (A1) with the composition containing EpCH, MAA and an alkali metal compound. For example, as described in paragraph 0014, the raw materials (EpCH and alkali metal compound, or EpCH and MAA) in step (1) may be mixed at the same time as charging. The MAA or alkali metal compound may be mixed with the raw material at the same time or before or after the MAA or alkali metal compound is mixed. It may be immediately before the operation of mixing the quaternary ammonium salt catalyst in the subsequent step (2). Moreover, there is no restriction | limiting in the method of mixing, The whole quantity may be mixed at once, and you may mix continuously or intermittently. As a method of mixing continuously or intermittently, the method may not be a method of mixing the whole amount at once. For example, publicly known methods such as a method of dropping over a certain period of time and a method of charging in a plurality of times may be mentioned, and these may be combined. Of these, the method of mixing the whole amount simultaneously with the charging of the raw materials is preferable.

In step (2), first, a quaternary ammonium salt catalyst is mixed with the reaction product solution containing the alkali metal salt of MAA and EpCH obtained in step (1).

  Known compounds can be used for the quaternary ammonium salt, such as tetramethylammonium chloride, trimethylethylammonium chloride, dimethyldiethylammonium chloride, methyltriethylammonium chloride, tetramethylammonium bromide, trimethylethylammonium bromide, dimethyldiethylammonium bromide, Examples thereof include methyltriethylammonium bromide, tetramethylammonium iodide, trimethylethylammonium iodide, dimethyldiethylammonium iodide, and methyltriethylammonium iodide. The amount of quaternary ammonium salt used is not particularly limited.

In the step (2), the concentration of the bisphenol polymerization inhibitor in the reaction solution comprising the reaction product solution, the quaternary ammonium salt and the bisphenol polymerization inhibitor is preferably maintained at 100 ppm or more. When the concentration of the bisphenol-based polymerization inhibitor is less than 100 ppm, the effect of suppressing the polymerization of double bonds possessed by GMA, MMA alkali metal salt, etc. is reduced, and a polymer may be formed.

However, the bisphenol polymerization inhibitor is denatured in the presence of a quaternary ammonium salt and loses its function as a polymerization inhibitor. In step (2), in order to maintain the concentration of the bisphenol polymerization inhibitor in the reaction solution at 100 ppm or more, the bisphenol polymerization inhibitor (A2) is continuously or intermittently added to the reaction solution.

As the bisphenol polymerization inhibitor (A2), specifically, 2,2′-methylene-bis (4-methyl-6-tert-butylphenol) (for example, “ANTAGE W-400”, manufactured by Kawaguchi Chemical Industry Co., Ltd.) 2,2′-methylene-bis (4-ethyl-6-tert-butylphenol) (for example, “ANTAGE W-500”, manufactured by Kawaguchi Chemical Co., Ltd.), 4,4-butylidene-bis- (3-methyl- 6-tert-butylphenol) (for example, “Adekastab AO40”, manufactured by ADEKA), tri-ethylene glycol-bis-3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate (for example, “Adekastab AO70 ", manufactured by ADEKA), 3,9-bis [1,1-di-methyl-2- {β- (3-tert-butyl-4-hydroxy) Roxy-5-methylphenyl) propionyloxy} ethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane (for example, “Adeka Stab AO80”, manufactured by ADEKA), N, N′-bis- 3- (3 ′, 5′-di-tert-butyl-4-hydroxyphenyl) propionylhexamethylenediamine (for example, “IRGANOX 1098”, manufactured by BASF Japan Ltd.) can be mentioned. As the bisphenol polymerization inhibitor (A2), at least one selected from the above compounds may be used, or a single or a combination of two or more may be used.
Among these, 2,2′-methylene-bis (4-methyl-6-tert-butylphenol) (Antage W-400) and 2,2′-methylene-bis (4-ethyl-6-tert-butylphenol) ( Antage W-500) is particularly preferred.

The time when the bisphenol polymerization inhibitor (A2) is continuously or intermittently mixed is a period from the start of the esterification reaction to the end of the esterification reaction. Specifically, it is a period from the mixing of the quaternary ammonium salt to the completion of the esterification reaction during the esterification reaction, simultaneously with the mixing of the quaternary ammonium salt. The end of the esterification reaction is when the alkali metal salt of MAA is almost consumed, as will be described later.

As a method of mixing continuously or intermittently, the method may not be a method of mixing the whole amount at once. Although the method of mixing continuously or intermittently is not specifically limited, For example, well-known methods, such as the method of dripping over fixed time and the method of throwing in in multiple times, are mentioned, The method which combined these may be used.

  In the step (2), the temperature and pressure when the alkali metal salt of MAA and EpCH are reacted are not particularly limited. Usually, the reaction is carried out at about 116 ° C. which is the boiling point of EpCH at normal pressure, and the reaction is completed when the alkali metal salt of MAA is almost consumed.

  In the present invention, the MAA of the total weight of the bisphenol polymerization inhibitor used in the steps (1) and (2) (that is, the total weight of the bisphenol polymerization inhibitor (A1) and the bisphenol polymerization inhibitor (A2)). The ratio with respect to the weight is preferably 1 wt% to 10 wt%, more preferably 1 wt% to 3 wt%. If it is less than 1 wt%, the effect of inhibiting the polymerization of MAA cannot be sufficiently obtained, and if it exceeds 10 wt%, it is uneconomical.

In the present invention, air may be blown into the system for the purpose of preventing polymerization in step (1) and step (2).

  When the esterification reaction is completed in step (2), a GMA-containing reaction product liquid (B) is obtained. The GMA-containing reaction product liquid (B) contains, in addition to the main product GMA, a by-product such as glycidol and unreacted EpCH, and an alkali metal chloride equivalent to the produced GMA is slurried. Included as Examples of the method for removing the slurry from the GMA-containing reaction product liquid (B) include known methods such as a method of removing by filtration, a method of removing by centrifugation, and a method of removing by water washing. Among them, the method of removing by washing with water is preferable.

  When removing the slurry by washing with water, it is preferable to cool the GMA-containing reaction product liquid (B), add water after the liquid temperature has dropped, and then perform a liquid separation operation. In the above, it is preferable to add water when the temperature of the GMA-containing reaction product liquid (B) is 80 ° C. or lower, more preferably 65 ° C. or lower. If water is added at a liquid temperature exceeding 80 ° C., by-products accompanying side reactions may increase, which is not preferable.

In the present invention, as described above, the concentration of the bisphenol polymerization inhibitor in the reaction solution is preferably 100 ppm or more in the period from the start of the esterification reaction to the end of the esterification reaction in step (2). In the period from the start of the esterification reaction in step (2) to the start of cooling after the completion of the esterification reaction, the concentration of the bisphenol polymerization inhibitor in the reaction solution and the GMA-containing reaction product solution (B) is 100 ppm or more. Is more preferable.

In the present invention, the cooling end point of the GMA-containing reaction product liquid (B) is a point just before the addition of water. In the period from the start of the esterification reaction in step (2) to the end of cooling of the GMA-containing reaction product liquid (B), the concentration of the bisphenol polymerization inhibitor in the reaction liquid and the GMA-containing reaction product liquid (B) is 100 ppm or more. More preferably,

In order to maintain the concentration of the bisphenol-based polymerization inhibitor at 100 ppm or more during the cooling period of the GMA-containing reaction product liquid (B), the bisphenol-based polymerization inhibitor (A3) is added to the GMA-containing reaction product liquid (B). You may mix. As the bisphenol-based polymerization inhibitor (A3), 2,2′-methylene-bis (4-methyl-6-tert-butylphenol) (for example, “ANTAGE W-400”, manufactured by Kawaguchi Chemical Industry Co., Ltd.), 2,2 '-Methylene-bis (4-ethyl-6-tert-butylphenol) (for example, “ANTAGE W-500”, manufactured by Kawaguchi Chemical Industry Co., Ltd.), 4,4-butylidene-bis- (3-methyl-6-tert- Butylphenol) (for example, “Adekastab AO40”, manufactured by ADEKA), tri-ethylene glycol-bis-3- (3-tert-butyl-5-methyl-4-hydroxyphenyl) propionate (for example, “Adekastab AO70”, ADEKA) 3,9-bis [1,1-di-methyl-2- {β- (3-tert-butyl-4-hydroxy-5) Methylphenyl) propionyloxy} ethyl] -2,4,8,10-tetraoxaspiro [5,5] undecane (for example, “Adekastab AO80”, manufactured by ADEKA), N, N′-bis-3- (3 ', 5'-di-tert-butyl-4-hydroxyphenyl) propionyl hexamethylenediamine (for example, “IRGANOX 1098”, manufactured by BASF Japan Ltd.). As the bisphenol polymerization inhibitor (A3), at least one selected from the above compounds may be used, or a single or a combination of two or more may be used.
Among these, 2,2′-methylene-bis (4-methyl-6-tert-butylphenol) (Antage W-400) and 2,2′-methylene-bis (4-ethyl-6-tert-butylphenol) ( Antage W-500) is particularly preferred.

As with the bisphenol polymerization inhibitor (A1), the bisphenol polymerization inhibitor (A3) may be mixed at any time in a solid state such as powder or pellets. It is preferable to do this. Although the solvent used in that case is not specifically limited, EpCH or GMA is preferable.

When the bisphenol polymerization inhibitor (A3) is dissolved in the solvent and mixed, the concentration of the bisphenol polymerization inhibitor in the solution is preferably 1 to 50 wt%, more preferably about 5 to 30 wt%. When the concentration is less than 1 wt%, the amount of the solvent increases, which leads to a decrease in reaction temperature and a decrease in production efficiency. If the concentration exceeds 50 wt%, it may not be sufficiently dissolved in the solvent from the viewpoint of solubility, which is not preferable.

The presence or absence of a polymer in the reaction solution obtained after the removal of the slurry can be determined by adding 0.5 cc of the reaction solution to 10 cc of methanol and whether or not white turbidity occurs in the methanol. When it becomes cloudy, a polymer is generated. When it is not cloudy, it is determined that no polymer is formed.

EXAMPLES Hereinafter, although this invention is demonstrated in more detail with an Example and a comparative example, this invention is not limited by these examples. The manufacturing conditions and manufacturing methods of GMA described in the examples are examples and can be changed as appropriate, and various devices used are also examples and can be changed as appropriate. A gas chromatograph (GC-1700, manufactured by Shimadzu Corporation) was used for analysis of 2,2'-methylene-bis (4-methyl-6-tert-butylphenol) in the reaction solution.

Example 1
EpCH648g, sodium carbonate 58g, 2,2'-methylene-bis (4-methyl-6-tert-butylphenol) 0.5g was weighed into a 1 L round bottom flask equipped with a stirrer, reflux condenser and decanter. In order to prevent polymerization, air was blown into the system and heated with stirring. After confirming the reflux of EpCH, 86 g of MAA was added dropwise over 1 hour, and then 0.25 g of tetramethylammonium chloride as a catalyst was added to carry out an esterification reaction for 60 minutes. At that time, simultaneously with the start of the esterification reaction, 5.0 g of 10 wt% of 2,2′-methylene-bis (4-methyl-6-tert-butylphenol) EpCH solution was added during the esterification reaction and after the reaction cooling step. During this time, dripping was continued in the system. After cooling, 240 g of ion exchange water was added, and after washing with water, a liquid separation operation was performed. The obtained oil phase was sampled in 0.5 cc and added to 10 cc of methanol, but it was confirmed that the oil phase did not become cloudy and no polymer was formed. Table 1 shows the concentration of the polymerization inhibitor in the extract during the esterification reaction and after washing with water.

Example 2
The amount of 2,2′-methylene-bis (4-methyl-6-tert-butylphenol) charged before the start of the reaction was 0.25 g, and 10 wt% of 2,2′- during the esterification reaction and during the post-reaction cooling step. The same operation as in Example 1 was performed except that 7.5 g of EpCH solution of methylene-bis (4-methyl-6-tert-butylphenol) was added dropwise. When 0.5 cc of the obtained oil phase was sampled and added to 10 cc of methanol, it was confirmed that the oil phase did not become cloudy and no polymer was formed. Table 1 shows the concentration of the polymerization inhibitor in the extract during the esterification reaction and after washing with water.

Example 3
The amount of 2,2′-methylene-bis (4-ethyl-6-tert-butylphenol) charged before the start of the reaction was 0.5 g, and 5 wt% of 2,2′- during the esterification reaction and during the post-reaction cooling step. The same operation as in Example 1 was performed except that 15 g of EpCH solution of methylene-bis (4-ethyl-6-tert-butylphenol) was added dropwise. When 0.5 cc of the obtained oil phase was sampled and added to 10 cc of methanol, it was confirmed that the oil phase did not become cloudy and no polymer was formed. Table 1 shows the concentration of the polymerization inhibitor in the extract during the esterification reaction and after washing with water.

Comparative Example 1
The amount of 2,2′-methylene-bis (4-methyl-6-tert-butylphenol) charged before the start of the reaction was 1.5 g, and 2,2′-methylene-bis was added during the esterification reaction and during the post-reaction cooling step. The same operation as in Example 1 was performed except that the EpCH solution of (4-methyl-6-tert-butylphenol) was not added dropwise. When 0.5 cc of the obtained oil phase was sampled and added to 10 cc of methanol, white turbidity was generated in the methanol, and formation of a polymer was confirmed. Table 1 shows the concentration of the polymerization inhibitor in the extract during the esterification reaction and after washing with water.

Comparative Example 2
The amount of 2,2′-methylene-bis (4-methyl-6-tert-butylphenol) charged before the start of the reaction was 0.5 g, and 5 wt% of 2,2′- during the esterification reaction and during the post-reaction cooling step. The same operation as in Example 1 was performed except that 5.0 g of EpCH solution of methylene-bis (4-methyl-6-tert-butylphenol) was added dropwise. When 0.5 cc of the obtained oil phase was sampled and added to 10 cc of methanol, white turbidity was generated in the methanol, and formation of a polymer was confirmed. Table 1 shows the concentration of the polymerization inhibitor in the extract during the esterification reaction and after washing with water.

Claims (1)

The following step (1) and step (2);
Step (1): A step of reacting methacrylic acid with an alkali metal compound in the presence of epichlorohydrin to synthesize an alkali metal salt of methacrylic acid,
Step (2): A quaternary ammonium salt catalyst is mixed with the reaction product liquid obtained in Step (1), and a bisphenol polymerization inhibitor is mixed continuously or intermittently to obtain an alkali metal of methacrylic acid. A step of synthesizing glycidyl methacrylate by esterifying a salt and epichlorohydrin,
A process for producing glycidyl methacrylate comprising
The concentration of the bisphenol polymerization inhibitor in the reaction solution is 110 ppm or more from the start of the esterification reaction to the end of the esterification reaction in step (2) ,
The bisphenol polymerization inhibitor is selected from 2,2′-methylene-bis (4-methyl-6-tert-butylphenol) and 2,2′-methylene-bis (4-ethyl-6-tert-butylphenol). The manufacturing method of the glycidyl methacrylate which is at least 1 or more .