JPH02262574A - Production of epoxidized (meth)acrylate - Google Patents

Abstract

PURPOSE:To industrially and advantageously obtain the subject compound to be used as an intermediate raw material for coating resins by epoxidizing a cyclohexenyl (meth)acrylate compound with an oxidizing agent (molecular oxygen-contg. gas) in the presence of a specific polymerization inhibitor. CONSTITUTION:The objective compound of formula II can be obtained by epoxidizing a cyclohexenyl (meth)acrylate compounds of formula I (R is H or methyl) with an oxidizing agent (molecular oxygen-contg. gas) under normal pressure in the presence of polymerization inhibitors consisting of at least each one compound selected from A-group (hydroquinone, p-benzoquinone, cresols, etc.) and B-group (phosphoric acid, pyrophosphoric acid, tripolyphosphoric acid, etc.). The amount to be used as said inhibitor is as follows: for the A-group compound, 0.005 to 5wt.% and, for the B-group compound, 0.001 to 1wt.%, each based on the amount of raw material, cyclohexenyl (meth)acrylate.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for producing an epoxidized (meth)acrylate compound.

(Meth)acrylate compounds can be easily homopolymerized or copolymerized with other unsaturated group-containing compounds in the presence of heat, ultraviolet rays, ionizing radiation, and radical polymerization initiators, and can also be used as intermediate raw materials for paint resins. is also useful.

(Prior Art) Various acrylic acid ester monomers have been known.

For example, monofunctional monomers such as methyl acrylate, ethyl acrylate, and 2-ethylhexyl acrylate, and polyfunctional monomers such as trimethylolpropane triacrylate, pentaerythritone, and lutriacrylate are generally known.

However, when monofunctional monomers are used in printing inks and paints, the odor of unreacted monomers after curing becomes a serious problem.

Furthermore, when polyfunctional monomers are used as diluents for paints and printing inks, they have to be used in large amounts relative to resins, which has the disadvantage that the properties of the resins are lost.

In this respect, the compound obtained by epoxidizing the cyclohexenylmethyl (meth)acrylate compound represented by the formula (R represents a hydrogen atom or a methyl group) with an oxidizing agent (in the formula, R represents a hydrogen atom or a methyl group) has a low It has high viscosity, low odor, and solubility in a wide range of resins, and is useful as a raw material or modifier for inks, paints, adhesives, coatings, and molding resins.

However, this epoxidized (meth)acrylic ester represented by formula (II) (hereinafter abbreviated as AETHB when R is a hydrogen atom, and METHB when R is a methyl group) is extremely easy to polymerize. Heat during the manufacturing process, storage and transportation,
It is known that it often polymerizes due to light and other factors.

In order to prevent this, in Japanese Patent Application No. 10083/1983, it was proposed that the (meth)acrylic acid ester, that is, AETHB (ME
It is disclosed that amines, especially piperidine, are preferred, although the ability to inhibit polymerization against THB) is not sufficient. Furthermore, although there is a description of a polymerization inhibitor in Japanese Patent Application No. 62-252217, there is no mention of its effect at all.
This is essentially the only prior art related to the polymerization prevention method B).

(Problems to be Solved by the Invention) In response to this, the present inventors have
It was confirmed that the effect of inhibiting the polymerization of AETHB (METHB) using piperidine alone or in combination with piperidine and a so-called conventional inhibitor such as hydroquinone as described in the No. 83 application was not yet sufficient.

One of the reasons for this is that at the time when Japanese Patent Application No. 10083/1983 was filed, AETHB (METHB) had not yet been produced on an industrial scale, so the quality that the product should have could not be fully predicted. be.

In other words, even if the product has a certain degree of polymerization prevention effect, in order to produce it on an industrial scale, it is important whether the obtained product meets the desired quality.

Developments in this regard have progressed since then, and it has become clear that there is a problem if trace amounts of polymers are included in the product.

For example, when synthesizing intermediate raw materials for paint resins, if AETHB (METHB) containing a polymer is used, the polymer will precipitate as a sticky insoluble substance, causing various problems in the process and reducing the commercial value of the paint. This will cause it to drop significantly.

The trace amounts of polymers contained in the product AETHB (METHB) are thought to be mainly composed of low molecular weight polymers of AETHB (METHB) itself, but the content of these polymers is higher than that of n-hexane or n-hebutane. This can be clearly confirmed by whether the product becomes cloudy when dissolved in a small amount (such a solubility test using n-hebutane is referred to below as H).
).

It is known that for AETHB (METHB) to be usable as a product, HT must be transparent or slightly cloudy.

On the other hand, when we examine the HT of AETHB (METHB) obtained by applying the method of Japanese Patent Application No. 10083/1983, we find that it is cloudy or cloudy enough to cause precipitation, so the quality is not sufficient. It is determined that there is no.

In other words, in order to industrially produce AETHB (METHB), it is necessary to establish a more effective method for inhibiting polymerization, and at the time the present inventors filed the application,
The technology that made this possible did not exist.

The inventors of the present invention conducted extensive research to address these issues, and found that the use of a specific polymerization inhibitor in combination with a molecular oxygen-containing gas perfectly meets the above objectives, and has finally achieved satisfaction in terms of quality. Obtain AETHB (MET
The present invention has been completed by manufacturing HB) on an industrial scale and establishing a method for maintaining quality in accordance with actual circumstances.

(Structure of the Invention) That is, the present invention provides a compound of the general formula (I) in which a cyclohexenyl methyl (meth)acrylate compound represented by the formula (I) (in which R represents a hydrogen atom or a methyl group) is epoxidized with an oxidizing agent. II) In the reaction step and low boiling point removal and/or product production step in the process of manufacturing the compound represented by (R represents a hydrogen atom or a methyl group), as a polymerization inhibitor together with a molecular oxygen-containing gas, A method for producing an epoxidized (meth)acrylate compound characterized by coexisting at least one compound selected from the following Groups A and B: [Group A] Hydroquinone, hydroquinone monomethyl ether,
P-benzoquinone, cresol, t-butylcatechol, 2,4-dimethyl-6-t-butylphenol, 2-
t-butyl-4-methoxyphenol, 3-t-butyl-4-methoxyphenol, 2,6-di-t-butyl-
P-cresol, 2,5-dihydroxy-P-quinone,
Piperidine, ethanolamine, α-nitroso-β-naphthol, diphenylamine, phenothiazine, N-nitrosophenylhydroxylamine, N,N-diethylhydroxylamine, [Group B] Ammonium hydrogen phosphate, potassium pyrophosphate, 2-pyrophosphate Ethylhexyl ester, potassium pyrophosphate-2-ethylhexyl ester, sodium birophosphate-2-ethylhexyl ester tripolyphosphate, potassium tripolyphosphate, sodium tripolyphosphate, tripolyphosphate-2-ethylhexyl ester, potassium tripolyphosphate-2-ethylhexyl ester, tetrapolyline Acid, potassium tetrapolyphosphate, sodium tetrapolyphosphate, 2-ethylhexyl tetrapolyphosphate, potassium tetrapolyphosphate? 2-ethylhexyl ester, sodium tetrapolyphosphate-2-ethylhexyl ester, potassium hexametaphosphate, and sodium hexametaphosphate.

The method for producing AETHB (METHB) will be described in detail below.

First, the epoxidation reaction step will be explained.

That is, a (meth)acrylate compound represented by formula CI) is epoxidized with an oxidizing agent.

The oxidizing agent used for this removal may be any oxidizing agent that can epoxidize unsaturated bonds, such as performic acid, peracetic acid, perpropionic acid, m
- Various hydroperoxides such as chloroperbenzoic acid, trifluoroperacetic acid, perbenzoic acid, tert-butyl hydroperoxide, cumyl hydroperoxide, tetralyl hydroperoxide, diisopropylbenzene hydroperoxide, hydrogen peroxide For example,

The oxidizing agent may be used in combination with a catalyst. For example, when an organic peracid is used, an alkali such as soda carbonate or an acid such as sulfuric acid may be used in combination as a catalyst.

Similarly, when using the above-mentioned various hydroperoxides, those having a known catalytic ability such as molybdenum hexacarbonyl can be used, and when using hydrogen peroxide, a mixture of tungstic acid and caustic soda can be used in combination.

When carrying out the reaction in batches, first, a predetermined amount of cyclohexenyl methyl (meth)acrylate is charged into the reactor.
A catalyst and a stabilizer are dissolved in this as required, and the oxidizing agent is added dropwise into the solution. The reaction molar ratio between the oxidizing agent and cyclohexenyl methyl (meth)acrylate is theoretically 1/1, but in the method of the present invention, it is 0.1 to 1.
It is preferably in the range of 0, preferably in the range of 0.5 to 10, more preferably in the range of 0.8 to 1.5.

If the molar ratio between the oxidizing agent and cyclohexenylmethyl (meth)acrylate exceeds 10, the conversion rate and reaction time of cyclohexenylmethyl (meth)acrylate will be reduced;
Although it is advantageous in terms of reducing loss due to polymerization of (meth)acrylate, it has disadvantages such as side reactions caused by excess oxidizing agent, oxidizing agent selectivity, and high cost when recovering unreacted oxidizing agent. be.

On the other hand, when the molar ratio of the reaction between the oxidizing agent and cyclohexenyl methyl (meth)acrylate is 0.1 or less, it is preferable in terms of the selectivity of the oxidizing agent, the conversion rate, and suppressing side reactions caused by the oxidizing agent. Disadvantages include loss due to polymerization of meth)acrylate, and large costs required to recover unreacted cyclohexenylmethyl (meth)acrylate.

The reaction temperature is carried out below the upper limit so that the epoxidation reaction has priority over the decomposition reaction of the oxidizing agent. For example, when using peracetic acid, it is 70°C or less, and when using tert-butyl hydroperoxide, it is 150°C or less. preferable.

If the reaction temperature is low, it will take a long time to complete the reaction, so it is preferable to carry out the reaction at a temperature higher than the lower limit of 0° C. when using peracetic acid and 20° C. when using tert-butyl hydroperoxide.

In addition, during the epoxidation reaction, a side reaction occurs in which the epoxy group is ring-opened with organic acids, alcohols, and water due to by-products from the oxidizing agent, so the temperature that reduces the amount of side reactions is set as described above. Select and implement from a temperature range.

The reaction pressure is generally operated at normal pressure, but it can also be carried out under elevated or low pressure.

Moreover, the reaction can also be carried out in the presence of a solvent.

Reaction in the presence of a solvent reduces the viscosity of the crude reaction solution and dilutes the oxidizing agent. This is preferable because it has effects such as stabilization.

Solvents used include aromatic compounds such as benzene, toluene, and xylene; halides such as chloroform/dimethyl chloride, carbon tetrachloride, and chlorobenzene;
Esterified products such as ethyl acetate and butyl acetate, ketone compounds such as acetone and methyl ethyl ketone, 1.2-
Ether compounds such as dimethoxyethane can be used.

The amount of solvent used is preferably 0.5 to 5 times the amount of cyclohexenylmethyl (meth)acrylate.

If the amount is less than 0.5 times, there will be little stabilization effect by diluting the oxidizing agent, and conversely, if the amount is more than 5 times, the stabilizing effect will not improve much and it will cost a lot to recover the solvent. It is a waste because it requires .

The key point of the present invention is to use a specific polymerization inhibitor together with a molecular oxygen-containing gas when carrying out the epoxidation reaction as described above.

However, if only the inhibitor described in Japanese Patent Application No. 10083/1983 is added during the epoxidation reaction, HT will result in cloudiness.

This is thought to be due to polymerization occurring during the reaction, albeit slightly.

However, since such a phenomenon is so slight that it cannot be clearly detected even with analytical equipment such as liquid chromatography, it is overlooked.

While the crude reaction solution, which becomes cloudy due to HT, undergoes a subsequent purification process and is turned into a product, polymerization proceeds further, and the IT of the product becomes cloudy to the extent that it is accompanied by a precipitate.

In response to this phenomenon, the present inventors injected molecular oxygen into the reaction crude liquid and made it coexist with at least one compound selected from Groups A and B. It was found that liquid can be obtained.

In particular, when three or more compounds defined by the present invention are used in combination, the effects are far superior to those obtained when each group of compounds is used alone or when only two compounds from each group are used in combination.
It is noteworthy that the synergistic effect is extremely large.

Next, the method of the present invention will be specifically explained.

In the present invention, air is usually used as molecular oxygen and is blown into the reactor.

The desired effect can be obtained by blowing directly into the liquid or into the gas phase.

The amount of blowing can be selected arbitrarily, but if it is too large, it is not preferable because it will result in solvent loss.

Additionally, in order to avoid the formation of an explosive mixture within the system, nitrogen is usually blown into the system along with air, but in that case it is preferable that the oxygen concentration in the blown gas is 0.01% (by volume) or more. is 3% (capacity) or more. The higher the oxygen concentration, the more effective it is, but the upper limit is the lower explosive limit oxygen concentration in the system, and that value varies depending on the solvent used.

Although it is not necessarily necessary to blow nitrogen into the same position as the air, it is important for safety to take measures to prevent the formation of locally explosive mixtures within the system.

It is known that some of the [group A] compounds used in the method of the present invention, such as hydroquinone, a combination of hydroquinone monomethyl ether and molecular oxygen, are effective in preventing the polymerization of so-called acrylic acid and acrylic esters. , the example of Japanese Patent Application No. 10083/1983 also compares the inhibition effect in an air atmosphere.

The reason why the method of the present invention adds at least one compound of [Group B] as an essential component is that the oxidizing agent used is effective in suppressing the decomposition and generation of radical sources, even if the amount is small. This is because it is thought that.

Next, the amount of polymerization inhibitor used can be arbitrarily changed depending on the type of target compound and manufacturing process conditions, but [Group A]
As a compound, it is 0.005 to 5% by weight based on cyclohexenylmethyl (meth)acrylate, which is a reaction raw material.
, more preferably 0°001 to 0.1% by weight, [Group B]
The compound is preferably added in an amount of 0.001 to 1% by weight, more preferably 0.01 to 0.2% by weight.

The addition method may be as a powder, or it may be added after being dissolved in a solvent.

The reaction is carried out continuously or batchwise, and in the case of continuous reaction, a piston flow type is preferred.

At this time, the polymerization inhibitors used in the method of the present invention may be added alone, but if they are in powder form, it is preferable to dissolve them in a solvent before adding them.

Alternatively, it may be dissolved in the raw material ester and charged.

Further, although the same applies to the case of a batch method, a semi-batch method in which the oxidizing agent is added sequentially is preferable.

The point of the present invention is to minimize polymerization or prevent polymerization in the reaction process in order to obtain a product, but the present invention can also be effectively applied to purification processes as is.

After the reaction is completed, the epoxidation reaction crude liquid contains a solvent, a low boiling point substance,
It can be purified by removing unreacted raw materials, catalysts, etc., neutralizing it, and treating it with an adsorbent or ion exchange resin.

Particularly when an organic peracid is used as the oxidizing agent, it is preferable to neutralize and wash the reaction crude solution with water. This is because if low-boiling components such as solvents are removed without neutralization, they are extremely likely to polymerize.

Examples of alkaline aqueous solutions used for neutralization include Na
OHSK OHSK COSN a 2 COa, N
a Aqueous solutions of alkaline substances such as HCOSK HCOSN Hs etc. can be used.

The concentration used can be freely selected from a wide range.

From the viewpoint of liquid separation, NaOH1Na2CO3 aqueous solution, Na
Preferably, an aqueous HCOa solution is used.

Neutralization and water washing at 10-90°C, preferably 410-50°C
It is best to perform this in the temperature range of ℃.

In order to remove low-boiling components from the reaction crude liquid that has been neutralized or washed with water, it is preferable to use a thin film evaporator or the like after adding a polymerization inhibitor.

In particular, there are cases where compounds selected from the [ASB group] contained in the crude reaction solution are extracted into the lower layer water and the content in the neutralized upper layer decreases. It is preferable to replenish an appropriate amount of. It is also desirable to blow molecular oxygen into the system during neutralization washing.

In the neutralization water washing step, it is important to neutralize and remove the organic acid as well as remove the residual organic peracid. In order to operate the next low-boiling point component removal step stably, neutralization should be repeatedly washed with water until the residual organic peracid content in the neutralized upper layer becomes 0.1% or less1, preferably 0.01% or less. There is a need.

Therefore, the continuous neutralization washing process requires a multi-stage process, but usually 3 to 5 stages can reduce the organic peracid concentration to below the specified value.

In the case of a multi-stage method, it is preferable to completely wash with water or use an alkaline aqueous solution of about 1% at most in the final stage.

This is because if the bottom liquid after removing low-boiling components is used as a product as it is, alkali metals will be mixed into the product and affect its quality.

This also applies to repeated batch neutralizations. In addition, when the neutralization water washing is carried out in a continuous manner, there is no problem in using the lower layer water in a countercurrent manner for pre-neutralization, and it is more economical.

The amount of alkali used for neutralization washing with water is 0.5 to 3 times, preferably 1.1 to 1.5 times, in equivalent ratio to the total amount of organic peracid and organic acid in the crude reaction solution. However, it is not economical to increase the amount more than necessary. Further, if the equivalent ratio is lowered more than necessary, it is not a good idea because a large amount of water is required to remove the organic peracid or organic acid, and furthermore, the loss of dissolution of the solvent and the like into the lower water increases.

Following the neutralization water wash step, the solvent is removed.

(Low-boiling removal process) A thin film evaporator is usually used for low-boiling removal, and the heating temperature is 50 to 180°C, preferably 60 to 180°C in order to prevent polymerization.
It is best to carry out the test at 00°C.

Although the pressure can be arbitrarily selected depending on the physical properties of the low boiling point component, it is common to operate under reduced pressure in relation to the heating temperature.

The location where molecular oxygen is introduced into the evaporator can be selected arbitrarily, but it is usually blown into the evaporator from the line where the bottom liquid is distilled.

The amount of injection can be selected arbitrarily, but the upper limit is determined by the capacity of the vacuum system, whether the bottom liquid flows down stably, and the recovery loss when collecting the distilled low-boiling components with a condenser. limited. Although the bottom liquid obtained in the low-boiling removal step has a purity of only 94 to 96%, as a result of the present invention, the quality is such that the HT is transparent or slightly cloudy.

Therefore, it can be used as a product for normal purposes.

In order to obtain a product with even higher purity, a commercialization step is next performed. The product production step completely removes residual low-boiling components and is carried out in the same manner as the low-boiling removal step, but it is generally carried out under high vacuum with an increased degree of reduced pressure.

Examples will be described in more detail below.

Example-1 Cyclohexenyl methyl methacrylate 7 was placed in a 5 g glass reactor equipped with a stirrer and a cooling jacket.
20g, ethyl acetate 2640g.

Hydroquinone monomethyl ether 0.3gr.

Add 0.3g of pyrophosphoric acid, and add 1Nff of oxygen/nitrogen (I0/90% by volume) mixed gas to the reactor from the insertion tube.
/Hr.

Next, the reaction temperature was maintained at 40°C, and a 30% peracetic acid solution
40 was charged over 3 hours using a metering pump. After the preparation was completed, the reaction was further aged for 5 hours and then terminated. 1g of crude reaction liquid
When the sample was collected and dissolved in 10 g of n-hebutane, it was completely transparent [the above is the synthesis process].

After cooling the reaction crude liquid to room temperature, 10% Na 2 C03
Add 2.5 kg and stir for 30 minutes, then leave to stand for 30 minutes to separate the liquids.

After removing the lower layer water, further 10% Na 2 C032-5k
Add g and perform the same operation.

At this time, the residual peracetic acid concentration in the upper layer liquid was 0.02%, and acetic acid had completely disappeared.

Next, when 5 kg of 1% Na CO was added and the same operation was performed, the peracetic acid concentration was 0.01% or less [the above is the neutralization step].

Next, add 0.6 kg of hydroquinone to 3.52 kg of the neutralized upper layer liquid.
g, 2-ethylhexyl sodium tripolyphosphate 0.
6 g was added, and low boiling temperature removal treatment was performed using a glass Smith type thin film evaporator.

The operating conditions were a heating temperature of 80° C., a pressure of 150 mmHg, and a mixed gas of oxygen/nitrogen (Io/90% by volume) was blown in at 5 NI/Hr from the bottom liquid distillation line. The amount of bottom liquid obtained was 735 g.

In addition, the composition was investigated by gas chromatography analysis and found that METH was 894.7%, ethyl acetate was 1.8%, cyclohexenyl methyl methacrylate was 1.0%, and others were 2.5%.
% [The above is the low-boiling removal process].

When 1g of the bottom liquid was dissolved in 10g of n-heptane, no precipitate was observed.

Example 2 The same conditions as Example 1 were used, except that 0.3 g of potassium pyrophosphate was added instead of pyrophosphoric acid in Example 1. No precipitate was observed in the n-hebutane test. Ta.

Example 3 The procedure was carried out under the same conditions as in Example 1, except that potassium 2-ethylhexyl pyrophosphate was added instead of pyrophosphoric acid in Example 1, and no precipitate was observed in the n-hebutane test. I couldn't.

Example-4 Except for adding 0.15 g of potassium pyrophosphate and 0.15 g of potassium 2-ethylhexyltripolyphosphate in place of pyrophosphoric acid in Example-1 (Example-1)
No precipitate was observed in the n-hebutane test under the same conditions as in 1.

Example-5 400g of the reaction crude solution obtained by the method of Example-1 was
% Na2CO3 was added for neutralization, and the neutralized supernatant liquid was passed through a glass thin film evaporator to drive off ethyl acetate.

This solvent expulsion step is carried out at a heating temperature of 80°C and a pressure of 150m.
At mHg, the evaporator was blown with a trace mixture of oxygen/nitrogen (I0/90% by volume).

The purity of METHB in the obtained concentrate was 95.5% as a result of gas chromatography analysis.

When 1 g of this concentrated solution was dissolved in 10 g of n-hebutane, it was transparent and passed as a product.

Comparative Example-1 (a) Oxygen/nitrogen (I0
The synthesis process was carried out under the same conditions as in Example 1, except that only nitrogen gas was blown in instead of the mixed gas (/90% by volume), and as a result of the n-hebutane test, white turbidity occurred.

(b) Example 1, except that birophosphoric acid was not added. The synthesis process was carried out under the same conditions as in Example 1, and an n-hebutane test was conducted. As a result, white turbidity also occurred in this case.

(C) Hydroquinone monomethyl ether pyrophosphoric acid in Example-1 was not added, but the rest was fixed <Example-
When the synthesis process was carried out under the same conditions as in 1 and an n-hebutane test was conducted, white turbidity also occurred in this case.

Comparative Example-2 (a> 1 g of the concentrated solution obtained by treating the crude reaction liquid obtained by the method of Comparative Example-1 (a) in the same manner as in Example-5 was dissolved in 10 g of n-hebutane. The mixture became cloudy and a precipitate was formed.

(b) Comparative Example-1 When the crude reaction liquid obtained by the method of (b) was treated in the same manner as in Example-5, the viscosity of the concentrated liquid increased halfway, so the operation was stopped and the evaporator was dismantled. However, a resinous polymer was found attached to it.

Further, when 1 g of the obtained concentrate was dissolved in 10 g of n-hebutane, it became cloudy and a precipitate was formed.

(C) Comparative Example-1 When the crude reaction liquid obtained by the method of (C) was treated in the same manner as in Example-5, the viscosity of the concentrated liquid increased halfway, so the operation was stopped and the evaporator was dismantled. However, a resinous polymer was found attached to it.

Further, when 1 g of the obtained concentrate was dissolved in 10 g of n-hebutane, it became cloudy and a precipitate was formed.

(d) When 0.3 g of hydroquinone monomethyl ether was added to the reaction crude liquid obtained by the method of Comparative Example 1 (C) and treated in the same manner as in Example 5, the viscosity of the concentrated liquid increased midway through. When operation was stopped and the evaporator was disassembled, resin-like polymers were found attached to it.

Further, when 1 g of the obtained concentrate was dissolved in 10 g of n-hebutane, it became cloudy and a precipitate was formed.

From the results of the above Examples and Comparative Examples, it is clear that the molecular oxygen-containing gas and at least one of each of Group A and Group B are
It is clear that no effect can be obtained unless the species compounds coexist.

Claims (1)

[Claims] General formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼(I) Oxidation of a cyclohexenylmethyl (meth)acrylate compound represented by (in the formula, R represents a hydrogen atom or a methyl group) Reaction steps and reduction steps in the process of producing a compound represented by the general formula (II) ▲Mathematical formula, chemical formula, table, etc.▼(II) (wherein R represents a hydrogen atom or a methyl group) by epoxidizing with a An epoxidized product characterized in that at least one compound selected from Group A and Group B below is allowed to coexist with a molecular oxygen-containing gas as a polymerization inhibitor in the boiling and/or product manufacturing process. Manufacturing method of (meth)acrylate compound: [Group A] Hydroquinone, hydroquinone monomethyl ether,
P-benzoquinone, cresol, t-butylcatechol, 2,4-dimethyl-6-t-butylphenol, 2-
t-butyl-4-methoxyphenol, 3-t-butyl-4-methoxyphenol, 2,6-di-t-butyl-
P-cresol, 2,5-dihydroxy-P-quinone,
Piperidine, ethanolamine, α-nitroso-β-naphthol, diphenylaminephenothiazine, N-nitrosophenylhydroxylamine, N,N-diethylhydroxylamine, [Group B] Phosphoric acid, potassium phosphate, sodium phosphate, ammonium hydrogen phosphate Sodium, pyrophosphoric acid, potassium pyrophosphate, sodium pyrophosphate, 2-ethylhexyl pyrophosphate, -2-ethylhexyl ester,
Sodium pyrophosphate-2-ethylhexyl ester,
Tripolyphosphoric acid, potassium tripolyphosphate, sodium tripolyphosphate, tripolyphosphate-2-ethylhexyl ester, tripolyphosphate potassium-2-ethylhexyl ester, tetrapolyphosphoric acid, potassium tetrapolyphosphate, sodium tetrapolyphosphate, tetrapolyphosphate-2-ethylhexyl ester , potassium tetrapolyphosphate-2-ethylhexyl ester, sodium tetrapolyphosphate-2-ethylhexyl ester, potassium hexametaphosphate, sodium hexametaphosphate.