JP2005247810A - Epoxy group-terminated (meth)acrylate - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an epoxy group-terminated (meth)acrylate capable of preventing such troubles that target physical properties of a final product are not obtained and weather resistance thereof is lowered when used as a raw material. <P>SOLUTION: This epoxy group-terminated (meth)acrylate expressed by general formula (1) contains a compound expressed by general formula (2) or general formula (3) in an amount of ≤0.5 wt%. It is preferable that the (meth)acrylate is obtained by reacting a compound having an acryloyl group with a compound having an epoxy group, wherein the compounds are reacted after the compound having the acryloyl group and/or the compound having the epoxy group are purified through an extraction process. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to an epoxy group-terminated (meth) acrylate, and particularly relates to a high-purity epoxy group-terminated (meth) acrylate useful as a raw material for paints and the like.

Epoxy group terminal (meth) acrylate can be manufactured as follows, for example. First, a monoglycidyl ether of a diol compound, which is a compound having an epoxy group, is synthesized by a direct dehalogenation addition reaction between a diol compound and an epihalohydrin using an alkali compound. Subsequently, it is transesterified by reacting with a compound having an acryloyl group, for example, (meth) acrylic acid ester (Patent Document 1).
JP-A-8-99968

  In the above addition reaction, an unreacted diol compound remains depending on the reaction conditions. In addition, a bis (glycidyloxy) alkane having epihalohydrin added to both ends of the diol compound is by-produced.

  By the way, when a transesterification reaction with (meth) acrylic acid ester is carried out using a hydroxyalkanglycidyl ether containing a compound as described above, the diol compound is transesterified at both ends to di (meth) acrylate. It converts and mixes in the target epoxy group-containing (meth) acrylate. Similarly, bis (glycidyloxy) alkane remains as it is in the epoxy group-terminated (meth) acrylate and is mixed.

  For example, glycidyloxybutyl acrylate is obtained by an ester exchange reaction between hydroxybutyl monoglycidyl ether (hereinafter abbreviated as 14BDMGE) synthesized by addition reaction of 1,4-butanediol (hereinafter abbreviated as 14BD) and epihalohydrin and an acrylic ester. (Hereinafter referred to as 4HBAGE due to the name of the raw material) can be produced, but in the 4HBAGE product, the unreacted diol compound as described above, 1,4-butanediacrylate (hereinafter abbreviated as BDA). In addition to bis (glycidyloxy) butane (hereinafter abbreviated as 14BDDDGE), it is considered that 14BDDDGE dimer and compounds derived from epihalohydrin are also mixed.

  By the way, in the above-mentioned prior art, no mention is made regarding the purification of the epoxy group-terminated (meth) acrylate and the influence of the contaminants. However, when a coating material or the like is produced using an epoxy group-terminated (meth) acrylate produced by a prior art method, there is a problem that the coating material has low weather resistance and remarkably deteriorated resin physical properties. Specifically, when the carboxylic acid or acid anhydride as a crosslinking agent is added to the target main component epoxy group-terminated (meth) acrylate and reacted, the above-described impurities reduce the crosslinking efficiency or molecular weight. (Change in polymerizability) occurred, and desired physical properties could not be obtained.

  The present invention has been made in view of the above circumstances, and its purpose is that when it is used as a raw material, crosslinking efficiency and molecular weight, which are target physical properties of the final target product, cannot be obtained, and problems such as deterioration in weather resistance are caused. The object of the present invention is to provide a novel epoxy-terminated (meth) acrylate without any problems.

  As a result of intensive studies, the present inventors have achieved high purity by limiting the content of a specific compound to a certain amount or less among compounds mixed in a large amount in the epoxy group terminal (meth) acrylate. In addition, the inventors have obtained knowledge that physical properties such as the weather resistance of the final object are improved, and have completed the present invention.

  That is, the gist of the present invention is that the content of the compound represented by the following general formula (2) or the compound represented by the following general formula (3) is 0.5% by weight or less. It exists in the epoxy group terminal (meth) acrylate shown by 1).

  According to the present invention, when used as a raw material, there is provided a novel epoxy-terminated (meth) acrylate that does not give the target physical properties of the final target product and does not cause problems such as deterioration in weather resistance. .

  Hereinafter, the present invention will be described in detail using 4HBAGE as an example. The characteristic of 4HBAGE of the present invention is that the content of BDA (compound represented by Y = 4 in the general formula (2)) or 14BDDDGE (compound represented by Y = 4 in the general formula (3)) is constant. It is in the point which is restricted to the range below. The content of BDA is 0.5% by weight or less, preferably 0.3% by weight or less, and the content of 14BDDDGE is 0.5% by weight or less, preferably 0.3% by weight or less. When the content exceeds the above, the object of the present invention cannot be achieved.

  The reason why the final object cannot achieve the target physical properties when the content of BDA is larger than the range specified in the present invention is estimated as follows. That is, if the amount of BDA is large, the acrylates at both ends react with the polymer main chain to prevent cross-linking at that portion, thereby reducing the cross-linking density, and as a result, adversely affecting the resin physical properties.

  The reason why the final object cannot achieve the target physical properties when the content of 14BDDDGE is larger than the range specified in the present invention is estimated as follows. That is, since there is no acrylate group, it does not react with the polymer main chain, prevents polymerization, lowers the degree of polymerization, and decreases the molecular weight. As a result, it is considered that the physical properties of the resin are similarly adversely affected.

  In particular, in recent years, 4HBAGE is frequently used as a raw material for surface coating, and in this case, stricter physical properties are required.

  The 4HBAGE production method employed in the present invention mainly comprises a 14BDMGE synthesis reaction, a separation process of the same compound, a 4HBAGE synthesis reaction, and a separation process of the same compound. Below, the manufacturing method of 4HBAGE is demonstrated for every said process.

(Synthesis reaction of 14BDMGE)
14BDMGE can be synthesized by a known method, for example, a method described in JP-A-8-99968. In general, an alkali compound is used and the diol compound (14BD) and epihalohydrin are directly dehalogenated and added.

  Here, the ratio (molar ratio) between 14BD and epihalohydrin subjected to the reaction is usually in the range of 1: 1.5 to 2: 1. When the molar ratio of epihalohydrin to 14BD is larger than the above range, the formation of 14BDDDGE increases. Conversely, when the molar ratio is smaller than the above range, a large amount of unreacted 14BD is present, and in any case, the target 14BDDMGE The yield decreases, which is not preferable.

(14BDMGE separation step)
For the separation of 14BDMGE, extraction with a water-insoluble organic solvent in the presence of water is suitable from the solution after the synthesis reaction in order to stably and efficiently remove impurities. Extraction in the present invention can be performed either batchwise or continuously, but considering the industrial superiority, for example, continuous extraction by a curl column type (Sumitomo Heavy Industries, Ltd.) is preferable.

  A continuous extraction method using a curl column will be described below, but the extraction rate of the target component 14BDDMGE is kept high, and two impurities, 14BD (which changes to BDA during the synthesis of the next step) and 14BDDDGE are efficiently used. In order to remove it, the extraction is carried out in two stages.

  (1) In the first stage extraction, 14BDDMGE and 14BD are extracted into the aqueous phase, and 14BDDDGE is extracted and removed into the organic solvent phase. Then, in the second stage extraction, only 14BDDMGE is extracted from the first stage aqueous phase to the organic solvent phase and separated from 14BD. Here, the purpose of the first stage and the second stage can be reversed. That is, (2): 14BDDMGE is extracted together with 14BDDDGE in the first stage organic phase and separated from 14BD, and 14BDDMGE is extracted in the second stage aqueous phase and separated from 14BDDDGE. Specific examples of the water-insoluble organic solvent at this time include aromatic hydrocarbons such as benzene, toluene and xylene, and chain saturated hydrocarbons such as N-hexane and N-heptane. Among these, toluene is preferable in both the first stage and the second stage.

The extraction method (1) will be described in detail. In the first stage, extraction is performed by adding water and toluene to the above-mentioned 14BDMGE synthesis reaction solution. That is, in the curl column type continuous extraction, water and a 14 BDMGE-containing reaction crude liquid are continuously added from the upper part of the column tower, and toluene is continuously added from the lower part of the column tower. Then, 14BDDDGE is extracted and removed in the upper phase (toluene phase), and 14BDDMGE and 14BD are extracted in the lower phase (aqueous phase). Here, a small amount of 14BDMGE is also extracted into the toluene phase. For the purpose of suppressing the amount, a method of adding methanol to the water to be added is also effective.

  The appropriate temperature in the column is usually about 10 to 60 ° C., although there are restrictions due to the extraction efficiency, the boiling point of the solvent used and the freezing point of water. The amounts of water, methanol and toluene used are as follows. That is, the amount of water / methanol mixture used is 0.5 to 20 times the mass ratio of 14BDMGE. The methanol concentration is 0 to 60% by weight with respect to water. If there is more methanol than this, the separability deteriorates. Moreover, the usage-amount of toluene is 1-20 times amount by mass ratio with respect to 14BDMGE. If the amount of toluene is less than this, 14BDDDGE is mixed in the water (and methanol) phase while being dragged by 14BDDMGE, and the extraction efficiency decreases. Moreover, when there is more toluene than the said range, it will become a cause of deterioration of manufacturing cost.

  In the second stage, extraction is performed by adding toluene to the aqueous phase of the first stage. That is, the first-stage aqueous phase is continuously added from the top of the column tower, and toluene is continuously added from the bottom of the column tower. Then, 14BDMGE is extracted in the upper phase (toluene phase), and 14BD is extracted and removed in the lower phase (aqueous phase). The amount of toluene used is 1 to 30 times the mass ratio of 14BDMGE in the first stage aqueous phase. If the amount of toluene used is less than this, 14BDDMGE is mixed in the water (and methanol) phase in a form dragged by 14BD, and the extraction efficiency is lowered. Moreover, when there is more usage-amount of toluene than the said range, it will become a cause of deterioration of manufacturing cost.

  Acquisition of 14BDMGE from the toluene phase is performed by removing toluene by a method such as distillation under reduced pressure. Thereby, 14BDDMGE and 14BDDMGE with reduced 14BD content can be obtained. The recovered toluene can again be used for extraction removal.

  As a method for reducing the content of 14BDDDGE, 14BD, BDA and other impurities, a distillation method is generally considered, but the boiling point of these compounds is close to that of 14BDDMGE or 4HBAGE, which is the target product. Separation alone, so-called rectification, is difficult. Moreover, the target product is thermally unstable and difficult to rectify.

(4HBAGE synthesis reaction)
A transesterification reaction between an acrylate ester and 14BDMGE is preferably used. The transesterification reaction is performed while distilling off the produced alcohol out of the system by azeotropy with a hydrocarbon organic solvent or the like. At this time, it is preferable to allow a polymerization inhibitor to coexist from the viewpoint of preventing polymerization of the acrylate ester. The organic solvent is introduced into the reaction system by a method such as batch preparation from the beginning of the reaction or sequential addition. It is also possible to use a large excess of acrylate and remove the alcohol out of the reaction system by azeotropy with the acrylate.

(4HBAGE separation process)
After obtaining an organic solvent phase containing 4HBAGE by simple extraction with an organic solvent, this is distilled and the organic solvent is distilled to obtain 4HBAGE with a reduced content of BDA and 14BDDDGE as a product. I can do it. Further, the extraction described in the “14BDMGE separation step” can also be performed in the “4HBAGE separation step”.

  The 4HBAGE of the present invention obtained by the above method is used for automobile paints, home appliances, information technology-related substrates, etc., especially when used in these top coats, compared to the case of using normal products. The physical properties of the final product obtained are greatly improved.

  EXAMPLES Hereinafter, although this invention is demonstrated in more detail than an Example, this invention is not limited to a following example, unless the summary is exceeded.

Example 1:
The production of 4HBAGE is described for each of the above steps. In addition, the measurement of the content of the main component and each impurity was performed by gas chromatography under the following description conditions.

(14BDMGE synthesis reaction)
14BD: 370 g (4.11 mol) and epichlorohydrin: 1500 g (16.21 mol) were charged into a 3 L four-necked flask equipped with a distillation apparatus, a thermometer, and a stirring apparatus. While stirring and heating and depressurization, dropwise addition of a 48 wt% NaOH aqueous solution: 360 g (4.32 mol) was started. At a reaction solution temperature of 65 ° C. and a reaction pressure of 150 mmHg, azeotropy of water produced by the reaction and epichlorohydrin started. Azeotropic water and epichlorohydrin were cooled and separated into two phases. Epichlorohydrin in the lower phase was distilled off only water while returning to the system. After 5 hours, the dropwise addition of the NaOH aqueous solution was completed, and further, heating and decompression were continued for 30 minutes, and then the reaction was completed. In order to remove NaCl produced as a by-product, 810 g of water was added, stirred for 30 minutes, allowed to stand for 30 minutes, and then the aqueous phase was taken out. Next, epichlorohydrin remaining in the reaction solution was recovered by a vacuum removal method. At this time, the crude 14BDMGE weight is 540 g, and the composition is 1,4BDMGE content of the main component: 64.3% by weight, 14BD of the raw material: 2.2% by weight, 14BDDDGE of the by-product: 14.1% by weight %Met. Moreover, the yield of 14BDMGE with respect to preparation 14BD was 58%, and the weight of purity 100% conversion was 347 g.

(14BDMGE separation process)
The above synthesis reaction was repeated two batches, and water: 1000 g and toluene: 3000 g were used for a portion of the obtained crude 14BDMGE: 1000 g (containing 643 g of 14BDMGE). ), 14BDDDGE and by-product derived from epichlorohydrin were recovered in the toluene phase, and 14BDDMGE and 14BD were recovered in the aqueous phase.

  Next, using 9300 g of toluene and the aqueous phase, liquid-liquid extraction (extraction second stage) was performed in a continuous extraction tower, 14BD was recovered in the aqueous phase, and 14BDMGE was recovered in the toluene phase. And toluene was collect | recovered by the reduced pressure removal method from the toluene phase, and 14BDMGE liquid: 612g was obtained. The composition was 1,4BDMGE content of the main component: 98.5% by weight, 14BD of impurities: 0.1% by weight or less, 14BDDDGE: 0.1% by weight or less. In addition, 14BDDMGE recovery by extraction purification was 95.2% (93.8% in terms of purity).

(4HBAGE synthesis reaction)
In a 3 L four-necked flask equipped with a distillation apparatus, a thermometer, and a stirring apparatus, the 1,4BDMGE liquid: 600 g (4.0 mol), acrylic acid methyl ester: 516 g (6.0 mol), titanium tetra-n- Butoxide: 28 g, p-methoxyphenol: 0.24 g, toluene: 400 g, n-hexane: 400 g were charged. Heating was started under stirring, and azeotropic distillation of methanol / n-hexane was performed at a reaction solution temperature of 73 to 90 ° C and a distillation temperature of 50 to 64 ° C. In the meantime, 400 g of n-hexane was continuously added. Then, reaction was performed for 8 hours and reaction was complete | finished.

(4HBAGE separation process)
Unreacted acrylic acid methyl ester was recovered from the reaction solution by a vacuum removal method. And the water: 500g and toluene: 1000g were added to the remaining liquid, and it stirred for 30 minutes, and liquid-separated, after leaving still for 60 minutes. 4HBAGE was recovered in the toluene layer, and unreacted 1,4BDMGE was recovered in the aqueous phase.

  Next, after removing a trace amount of solids in the toluene phase by suction filtration using filter paper, toluene was recovered by a reduced pressure removal method to obtain 4HBAGE as a target product. As a result, 695 g of 4HBAGE having a purity of 99.5% by weight was recovered. BDA as an impurity was 0.1% by weight or less, and 14BDDDGE was 0.1% by weight or less.

Comparative Example 1:
After 14BDMGE synthesis reaction in the same manner as in Example 1, NaCl / epichlorohydrin was removed to obtain a crude 14BDMGE solution. Subsequently, 200 g of crude 14BDMGE liquid (containing 128.6 g of 14BDMGE) was distilled using a distillation apparatus equipped with a Witmer rectification tube. Under conditions of a pressure of 2 mmHg, a tower top temperature of 105 ° C., and a bottom temperature of 155 ° C., 101 g of 14BDMGE liquid was obtained. The composition was such that the main component 1,4BDMGE content was 94.8% by weight, the impurity 14BD was 2.0% by weight, and 14BDDDGE was 2.2% by weight. In addition, 14BDDMGE recovery by distillation was 78.5% (74.5% in terms of purity).

  Next, 100 g of 14BDMGE obtained by distillation was used, 4HBAGE synthesis reaction and methyl acrylate removal were carried out in the same manner as in Example 1, water: 83 g, toluene: 166 g were added, and the mixture was stirred for 30 minutes and stirred for 60 minutes. After standing, liquid separation was performed, and 4HBAGE was collected in the toluene layer. After removing a trace amount of solids in the toluene phase by suction filtration using filter paper, toluene was recovered by vacuum removal to obtain 4HBAGE as the target product. As a result, 116 g of 4HBAGE having a purity of 94.9% was recovered. BDA as an impurity was 2.4% by weight, and 14BDDDGE was 1.9% by weight.

Claims (8)

The epoxy group terminal represented by the following general formula (1), wherein the content of the compound represented by the following general formula (2) or the compound represented by the following general formula (3) is 0.5% by weight or less. (Meth) acrylate.
  2. The epoxy group-terminated (meth) acrylate according to claim 1, wherein the content of the compound represented by the general formula (2) and the compound represented by the general formula (3) is 0.5% by weight or less, respectively.   The epoxy group terminal (meth) acrylate of Claim 1 or 2 obtained by refine | purifying by an extraction process.   An epoxy group-terminated (meth) acrylate represented by the general formula (1) obtained by reacting a compound having an acryloyl group with a compound having an epoxy group, and / or a compound having the acryloyl group by an extraction step and / or The epoxy group terminal (meth) acrylate in any one of Claims 1-3 obtained by making it react after refine | purifying the compound which has the said epoxy group.   The epoxy group terminal (meth) according to claim 4, wherein the content of the compound represented by the general formula (2) after purification of the compound having an acryloyl group and / or the compound having an epoxy group is 0.5% by weight or less. Acrylate.   The epoxy group terminal (meth) according to claim 4, wherein the content of the compound represented by the general formula (3) after purification of the compound having an acryloyl group and / or the compound having an epoxy group is 0.5% by weight or less. Acrylate.   The epoxy group terminal (meth) acrylate according to any one of claims 1 to 6, which is used as a raw material for surface coating.   The epoxy group terminal (meth) acrylate according to any one of claims 1 to 7, wherein Y in the general formula (1) is an alkylene group having 4 carbon atoms.