JP2003342268A - Method for producing epoxy-terminated (meth)acrylate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an improved method for producing an epoxy-terminated (meth)acrylate to enable easy recovery of the objective compound from a reaction liquid in high yield. <P>SOLUTION: The epoxy-terminated (meth)acrylate expressed by formula (II) (Y is a bivalent hydrocarbon group which may contain oxygen in the main chain; and R is H or an alkyl) is produced by the transesterification reaction of a (meth)acrylic acid lower ester with a hydroxyglycidyl ether of formula (I) in the presence of a transesterification reaction catalyst. The transesterification reaction liquid is distilled after the reaction in the presence of a polymerization inhibitor to recover the epoxy-terminated (meth)acrylate. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing an epoxy group-terminated (meth) acrylate.

[0002]

2. Description of the Related Art As one of the general methods for producing an epoxy group-terminated (meth) acrylate, a (meth) acrylic acid lower ester and a hydroxy group represented by the following general formula (I) are used in the presence of a transesterification reaction catalyst. A method for transesterification with glycidyl ether is conceivable. in this case,
After the reaction, the most common method is to add water or acid to the transesterification reaction solution to deactivate the catalyst, extract the resulting epoxy group-terminated (meth) acrylate with an organic solvent, and then isolate by vacuum distillation. Is.

[0003]

[Chemical 2]

However, in the case of the above method, an insoluble component is produced during extraction in the presence of water, the interface in phase separation becomes unclear, and further, even if the insoluble component is not removed by filtration, it is still filtered. It takes a long time, and therefore the recovery operation of the target product is not easy and the yield is low.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and its object is to improve the recovery of the target product from the reaction solution easily and in high yield. Another object is to provide a method for producing an epoxy group-terminated (meth) acrylate.

[0006]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that if a polymerization inhibitor is added to a transesterification reaction solution, the purpose of the transesterification reaction catalyst is not deactivated by water. The present invention has been completed based on the finding that the product can be easily recovered by distillation in a high yield.

That is, the gist of the present invention is to subject a (meth) acrylic acid lower ester and a hydroxyglycidyl ether represented by the following general formula (I) to transesterification reaction in the presence of a transesterification reaction catalyst. A method for producing an epoxy group-terminated (meth) acrylate represented by (II), which comprises, after the reaction, distilling the transesterification reaction solution in the presence of a polymerization inhibitor for the epoxy group-terminated (meth) acrylate to obtain an epoxy group It exists in the manufacturing method of the epoxy group terminal (meth) acrylate characterized by collect | recovering terminal (meth) acrylate.

[0008]

[Chemical 3]

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The production method of the present invention comprises a reaction step and a step of recovering a target substance.

<Reaction Step> First, in the present invention, a (meth) acrylic acid lower ester is transesterified with a hydroxyglycidyl ether represented by the general formula (I) in the presence of a transesterification reaction catalyst. The epoxy group-terminated (meth) acrylate represented by the general formula (II) is manufactured.

As the transesterification catalyst, general transesterification catalysts such as titanium alcoholate, organic tin, weak acid salts of alkali metals or alkaline earth metals (carbonates, acetates, phosphates, etc.), alkali metal alkoxides, etc. Is used. Among these, titanium alcoholate or organotin compound is preferable.

A reaction solvent is used as needed. Examples of the reaction solvent include cyclic hydrocarbons such as toluene and chain saturated hydrocarbons such as n-hexane. From the viewpoint of operability, it is preferable to use the starting material (meth) acrylic acid lower alkyl ester in excess as a solvent.

Examples of the (meth) acrylic acid lower ester include (meth) acrylic acid methyl ester, ethyl ester and butyl ester. Particularly, methyl ester or ethyl ester is preferable.

As the hydroxyglycidyl ether represented by the general formula (I), 1,4-butanediol monoglycidyl ether, 1,3-propanediol monoglycidyl ether, 1,5-pentanediol monoglycidyl ether, 1 , 4-cyclohexanedimethanol monoglycidyl ether and the like. They are,
It can be synthesized by the method described in JP-A-8-99968.

In the present invention, a polymerization inhibitor may be used in the reaction solution in order to prevent polymerization of the acryloyl group. Examples of such polymerization inhibitors include phenothiazine, aromatic amines such as p-phenylenediamine, hydroquinone, phenol derivatives such as p-methoxyphenol, nitroso compounds, aromatic nitro compounds, copper-based or lead-based polymerization inhibitors, and the like. Can be mentioned.

Examples of the copper-based polymerization inhibitor include copper dibutyldithiocarbamate and copper acetate, and examples of the lead-based polymerization inhibitor include lead stearate.

Further, in the present invention, oxygen can be introduced into the reaction system for the same reason as above. In this case, oxygen is preferably diluted with an inert gas and introduced into the reaction system so that the reaction system does not enter the explosion range.

The reaction can be carried out continuously or batchwise. The amount of the catalyst used is usually 0.1 to 10 mol%, preferably 0.5 to 10% based on hydroxyglycidyl ether.
It is 5 mol%. The (meth) acrylic acid lower alkyl ester is used in an amount of usually 1 to 10 times mol, preferably 2 to 5 times mol, of the hydroxyglycidyl ether. The reaction temperature is usually 50 to 130 ° C., preferably 60.
The reaction time is usually 1 to 24 hours, preferably 3 to 12 hours.

When a polymerization inhibitor is used, its proportion is usually 0.0 relative to hydroxyglycidyl ether.
It is 1 to 1% by weight, preferably 0.1 to 0.3% by weight. When oxygen is introduced into the reaction system, its concentration is
Considering the explosion range, it is usually 0.1 to 6% by volume, preferably 1 to 5% by volume.

In the present invention, a distillation operation is adopted in the step of recovering the target substance described later. Therefore, in order to increase the purity of the target product, it is preferable to minimize the residual rate of hydroxyglycidyl ether, which is a raw material having a boiling point close to that of the target product. Specifically, it is preferable to add 0.5 to 4.0 times mol of (meth) acrylic acid lower alkyl ester to hydroxyglycidyl ether to improve the raw material conversion rate. The residual ratio of hydroxyglycidyl ether in the transesterification reaction liquid is preferably 1% by weight or less. Since this reaction is an equilibrium reaction, the reaction can be further progressed by distilling off the by-produced lower alcohol out of the reaction system.

<Recovery of Target> In the present invention, after the reaction, the transesterification reaction solution is distilled in the presence of a polymerization inhibitor for the epoxy group-terminated (meth) acrylate to distill the epoxy group-terminated (meth) acrylate. Collect.

The above polymerization inhibitors include copper-based, lead-based,
Cadmium-based or zinc-based polymerization inhibitors may be mentioned.
As the copper-based polymerization inhibitor and the lead-based polymerization inhibitor, the same ones as described above can be used. Examples of the cadmium-based polymerization inhibitor include cadmium stearate, and examples of the zinc-based polymerization inhibitor include zinc diethyldithiocarbamate. These may be used alone or in combination of two or more. Among the above, a copper-based polymerization inhibitor is preferable from the viewpoint of toxicity.

The proportion of the polymerization inhibitor used is usually 0.5 to 10 times by mole, preferably 1 to 5 times, the amount of the transesterification catalyst.
It is twice the mole.

The distillation method may be either a batch method (batch) or a continuous method (thin film distillation), but a thin film distillation having a short retention time is preferable for more stable isolation of the target substance. The distillation temperature is usually 14 from the viewpoint of thermal stability.
It is preferably 0 ° C. or lower, preferably 120 ° C. or lower.

The epoxy group-terminated (meth) acrylate produced as described above, typically 2-glycidyloxyethyl methacrylate, is disclosed in JP-B-48-22169.
It is useful as a raw material for paints or resin improvers as disclosed in Japanese Patent Publication No. Such a compound exhibits a property useful as a coating film by carrying out vinyl polymerization at the (meth) acryloyl group portion and then crosslinking reaction with other functional group at the epoxy group portion of the side chain.

[0026]

EXAMPLES The present invention will be described in more detail with reference to examples below, but the present invention is not limited to the following examples as long as the gist thereof is not exceeded. In the following examples, “%” means “% by weight”.

Example 1 <Production of 4-hydroxybutyl acrylate glycidyl ether> 1,4 butanediol monoglycidyl ether 19 was placed in a flask equipped with a glass tube having a length of 20 cm.
8.1 g (1.36 mol), methyl acrylate 52
5.0 g (6.11 mol), polymerization inhibitor: copper dibutyldithiocarbamate 0.40 g (0.0008 mol)
And titanium tetra-n-butoxide 4.6 g (0.01
36 mol) was charged, and the reaction was carried out for 8 hours under reflux at 85 to 105 ° C. while distilling off the produced methanol. Then, when the residual rate of 1,4 butanediol monoglycidyl ether reached 1% or less, the reaction was terminated. During this period, the distillation temperature at the top of the column was 32 to 75 ° C. After completion of the reaction, excess methyl acrylate was distilled off.

12.82 g (0.02714 mol) of copper dibutyldithiocarbamate was added to the reaction solution obtained above.
Is added, and the bath temperature is 140 in the presence of an ester exchange catalyst.
℃, liquid temperature 130 ℃, tower top temperature 125 ℃, vacuum degree 5mmH
Distillation was performed at g. 204 g of 4-hydroxybutyl acrylate glycidyl ether obtained from this fraction
(1.02 mol), and as a result of analysis by gas chromatography, 4-hydroxybutyl acrylate glycidyl ether 97.3%, 1,4 butanediol monoglycidyl ether 0.54%, 1,4 butanediol diglycidyl ether 0 It was 0.76% and butanediacrylate 0.67%. The yield based on 1,4 butanediol monoglycidyl ether as a raw material was 75%.

Comparative Example 1 624.2 g of 1,4 butanediol monoglycidyl ether was placed in a flask equipped with a glass tube having a length of 20 cm.
(4.28 mol), 919.2 g of methyl acrylate
(10.69 mol), polymerization inhibitor: dibutyldithiocarbamate copper 1.25 g (0.0026 mol) and titanium tetra-n-butoxide 14.54 g (0.043).
mol) was charged, and the reaction was carried out under reflux at 85 to 120 ° C. for 9.5 hours while distilling off the produced methanol. At this point, the content of 1,4 butanediol monoglycidyl ether was less than 1%, so 367.7 g (4.28 mol) of methyl acrylate was added, and the reaction was further continued for 2 hours. During this period, the distillation temperature at the top of the column was 60 to 8
It was 0 ° C. After completion of the reaction, methyl acrylate was distilled off.

77.4 g of water was added to the reaction solution obtained above.
(4.28 mol) was added, and the mixture was stirred at room temperature for 2 hours, and then distilled under reduced pressure. The obtained 4-hydroxybutyl acrylate glycidyl ether was 582.08 g (2.9
1 mol), the result of analysis by gas chromatography was 4-hydroxybutyl acrylate glycidyl ether 94.8%, 1,4 butanediol monoglycidyl ether 3.2%, 1,4 butanediol diglycidyl ether 0.4%, Butane diacrylate 1.04%
Met. The yield based on 1,4 butanediol monoglycidyl ether as a raw material was 68%. However, an increase in the amount of 1,4 butanediol monoglycidyl ether before and after distillation was confirmed by the gas chromatography internal standard method.

Comparative Example 2 147.7 g of 1,4 butanediol monoglycidyl ether was placed in a flask equipped with a glass tube having a length of 20 cm.
(1.01 mol), methyl acrylate 430.0 g
(5.0 mol), polymerization inhibitor: 0.29 g (0.00061 mol) of copper dibutyldithiocarbamate and 5.27 g (0.0155 m) of titanium tetra-n-butoxide.
was charged and the reaction was carried out for 8 hours under reflux at 85 to 115 ° C. while distilling off the produced methanol. After completion of the reaction, methyl acrylate was distilled off.

To the reaction solution obtained above, toluene 17
8.2 g and 102.78 g of water were added and stirred at 60 ° C. for 1 hour to hydrolyze the catalyst. At this time, a deactivated product of TBT was generated in the intermediate phase. After liquid separation, the toluene phase was filtered.
An attempt was made to recover the target substance existing in the intermediate phase by filtration, but the filterability was poor and the process was interrupted.

Next, after removing toluene in the toluene phase by distillation, distillation was performed under reduced pressure. Obtained 4-
Hydroxybutyl acrylate glycidyl ether is 7
0.7 g (0.35 mol), which was analyzed by gas chromatography and found to be 96.64% 4-hydroxybutyl acrylate glycidyl ether, 0.95% 1,4 butanediol monoglycidyl ether, and 1,4 butanediol diglycidyl. The amount of ether was 1.32% and the amount of butanediacrylate was 0.68%. The yield of the raw material 1,4 butanediol monoglycidyl ether is 35.
%Met.

[0034]

According to the present invention described above, there is provided a method for producing an epoxy group-terminated (meth) acrylate, which is improved so that the desired product can be easily recovered from the reaction solution in a high yield. As provided, the industrial value of the present invention is great.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Shoji Sakamoto             34 Takayama, Onahama, Iwaki City, Fukushima Prefecture Japan             Kasei Co., Ltd. F-term (reference) 4H039 CA66 CD90

Claims (2)

[Claims] 1. A (meth) acrylic acid lower ester and a hydroxyglycidyl ether represented by the following general formula (I) are subjected to a transesterification reaction in the presence of a transesterification reaction catalyst to obtain a compound represented by the following general formula (II). A method for producing an epoxy group-terminated (meth) acrylate, the method comprising: after the reaction, distilling the transesterification reaction solution in the presence of a polymerization inhibitor for the epoxy group-terminated (meth) acrylate to obtain the epoxy group-terminated (meth) acrylate. A method for producing an epoxy group-terminated (meth) acrylate, which comprises recovering. [Chemical 1] 2. The production method according to claim 1, wherein a copper-based polymerization inhibitor is used.