JPWO2016035573A1 - Method for producing (meth) acrylic ester mixture - Google Patents

Abstract

An object of this invention is to provide the method of manufacturing the ester body of partial (meth) acrylic acid with a simple method with sufficient yield. The following 1st process and 2nd process are included, Content of the (meth) acrylic acid ester component which has two hydroxyl groups is 15-50 mass% with respect to the total mass of an ester body, It is characterized by the (meta ) Method for producing acrylic ester mixture. 1st process: It is the process of obtaining an intermediate mixture by esterification reaction of (meth) acrylic acid and a polyhydric alcohol in the presence of an acid catalyst until the reaction rate based on hydroxyl groups reaches 45%. The amount of water contained in the reaction solution is maintained at a specific value, and the esterification reaction is stopped when the reaction rate is 45 to 65%. The esterification reaction step second step: an organic solvent is added to the intermediate mixture. Neutralization treatment step in which the water content in the organic phase added and neutralized with an aqueous alkali solution and separated from the aqueous phase after the neutralization treatment is a specific value

Description

  The present invention relates to a method for producing a (meth) acrylic ester mixture by esterifying (meth) acrylic acid and a polyhydric alcohol. Specifically, it is characterized in that the esterification reaction is carried out while controlling the amount of water contained in the reaction solution, and the amount of water in the organic phase is controlled when neutralizing the reaction solution after the esterification reaction (meta ) A method for producing an acrylic ester mixture.

  (Meth) acrylic acid ester obtained by reacting (meth) acrylic acid with polyhydric alcohol is used as a component of hard cord paints because its cured product exhibits high hardness and excellent wear resistance. ing. In particular, partial (meth) acrylic acid esters in which some hydroxyl groups of polyhydric alcohols are esterified have two types of functional groups, hydroxyl groups and unsaturated groups, in a single molecule, unlike wide ester forms. It can be used to manufacture a wide range of products using formats. For example, urethane acrylate obtained by reacting a polyvalent isocyanate compound with a partial (meth) acrylic acid ester is used as a coating agent for various substrates.

  Conventionally, partial (meth) acrylic acid esters of polyhydric alcohols are produced as a mixture of ester bodies by dehydration esterification of (meth) acrylic acid and polyhydric alcohols. Furthermore, the mixture containing the partial (meth) acrylic acid ester is recovered from the reaction solution through neutralization treatment, water washing treatment, and the like, and purified by distillation or the like as necessary.

As a conventional method for producing a partial (meth) acrylic ester of a polyhydric alcohol, methods described in Patent Documents 1 to 3 are described.
In Patent Document 1, in the production of dipentaerythritol polyacrylate obtained by esterification of dipentaerythritol, which is a polyhydric alcohol, and acrylic acid, the esterification reaction product is converted into aromatic hydrocarbon and aliphatic or alicyclic. Washing with a mixed solvent with hydrocarbons and water is described.

  In Patent Document 2, when dehydrating esterification reaction of (meth) acrylic acid and a polyhydric alcohol, the amount of water contained in the reaction solution is excluded from the organic solvent until the reaction rate reaches 80%. The manufacturing method which controls to 6 mass% or less with respect to the total mass of a liquid component is described.

  In Patent Document 3, as a method for selectively producing partial (meth) acrylate in a dehydration esterification reaction of (meth) acrylic acid and a polyhydric alcohol, the esterification reaction is stopped at a low reaction rate. Thus, a method is described in which the obtained (meth) acrylate having a low degree of esterification is recovered and reused to produce with good yield.

JP-A-2-306938 JP 2007-176881 A JP 2007-169193 A

  According to the conventional method for producing a partial (meth) acrylic acid ester of a polyhydric alcohol, it is difficult to selectively produce only a partial (meth) acrylic acid ester. Manufactured as a mixture.

However, partial (meth) acrylic acid esters are considered difficult to produce in high yield for the following reasons.
For example, since polyhydric alcohols such as pentaerythritol and dipentaerythritol are crystalline solids, if the reaction is stopped at a stage where the reaction rate before becoming fully esterified is low, the unreacted polyhydric alcohol is in a solid state It is necessary to separate these by filtration and the esterification reaction solution is washed with water to remove the remaining catalyst and neutralized to remove unreacted (meth) acrylic acid. Although separation is required, partial (meth) acrylic acid esters tend to be distributed more in the aqueous phase than in the organic phase, and thus the recovery method becomes complicated.

  Among the products that are currently commercialized as pentaerythritol tri (meth) acrylates, the one having the highest hydroxyl value has a hydroxyl value of about 160 mgKOH / g, and its main components are tri (meth) acrylate and tetra ( The content of the di (meth) acrylic acid ester which is a mixture with a (meth) acrylic acid ester and has two hydroxyl groups which are lower ester bodies is 10% by mass or less.

Moreover, it is difficult to recover a partial (meth) acrylic acid ester as a target product in an organic phase only by a combination of cleaning solvents described in Patent Document 1.
According to the method described in Patent Document 2, since the reaction rate is 80% or more, it is difficult to produce a partial (meth) acrylic acid ester with a high yield.
In the method described in Patent Document 3, there is no description of specific conditions for selectively producing a partial (meth) acrylate, and (meth) acrylate having a low degree of esterification in an aqueous phase is repeatedly reused. Therefore, the operation becomes complicated and it is not an economically advantageous method.

  In view of the above situation, an object of the present invention is to provide a method for producing an ester of partial (meth) acrylic acid, which is difficult to produce efficiently by a conventional production method, with a simple method and in a high yield. And

  As a result of intensive studies to solve the above problems, the present inventors adjusted the ratio of the amount of water contained in the reaction solution until the middle of the reaction in the esterification reaction of (meth) acrylic acid and polyhydric alcohol, And by stopping the reaction before proceeding to the complete esterification reaction, and further adjusting the amount of water in the aqueous phase separated after the neutralization treatment of the reaction solution, a partial (meth) acrylic acid ester of polyhydric alcohol It was found that a (meth) acrylic acid ester having two hydroxyl groups can be produced with high yield.

That is, the first invention of the present invention includes the following first step and second step, and the content of the (meth) acrylic acid ester component having two hydroxyl groups is 15 to 50% by mass relative to the total mass of the ester body. It is a manufacturing method of the (meth) acrylic acid ester mixture characterized by these.
First step:
In the presence of an acid catalyst, an intermediate mixture is obtained by esterification reaction of (meth) acrylic acid and a polyhydric alcohol, and the reaction solution is mixed until the reaction rate based on hydroxyl groups reaches 45%. The esterification reaction step in which the amount of water contained is maintained at 0 to 12% by mass with respect to the total mass of the reaction liquid excluding the organic solvent, and the esterification reaction is stopped at the stage where the reaction rate is 45 to 65%. Second step:
To the intermediate mixture obtained in the first step, an organic solvent is added, neutralized with an aqueous alkali solution, and the water content in the organic phase separated from the aqueous phase after the neutralization is the total mass of the organic phase. The neutralization process which is 1-10 mass% with respect to

  According to a second aspect of the present invention, in the first step, when the reaction rate reaches 45%, the amount of water contained in the reaction solution is 6 to 6 based on the total mass of the reaction solution excluding the organic solvent. It is a manufacturing method of the (meth) acrylic acid ester mixture which is 10 mass%.

  3rd invention of this invention is a manufacturing method of the (meth) acrylic acid ester mixture whose moisture content in the said organic phase is 3-7 mass% with respect to the total mass of an organic phase.

  4th invention of this invention is 30-100 mass with respect to the total mass of an organic solvent, as for the organic solvent in a 2nd process, the octanol-water partition coefficient (logPow) in 25 degreeC is -1-2. % (Meth) acrylic acid ester mixture production method.

  5th invention of this invention is a manufacturing method of the (meth) acrylic acid ester mixture whose said polyhydric alcohol is pentaerythritol, dipentaerythritol, or isocyanuric acid tris (2-hydroxyethyl).

  In a sixth aspect of the present invention, the organic solvent in the second step contains at least one selected from the group consisting of methyl ethyl ketone, ethyl acetate and propyl acetate in an amount of 30 to 100% by mass based on the total mass of the organic solvent. , (Meth) acrylic acid ester mixture manufacturing method.

  According to the production method of the present invention, a (meth) acrylic acid ester mixture containing a large amount of (meth) acrylic acid ester components having two hydroxyl groups can be obtained by a simple method with good yield.

The present invention will be described in detail below.
In the present invention, as (meth) acrylic acid, acrylic acid may be used alone, methacrylic acid may be used alone, or acrylic acid and methacrylic acid may be used in combination.
In the present invention, the description of “lower limit to upper limit” representing a numerical range represents “more than the lower limit and less than or equal to the upper limit”, and the description of “upper limit to lower limit” represents “the upper limit or less and less than the lower limit”. That is, it represents a numerical range including an upper limit and a lower limit.
In the present invention, a combination of preferred embodiments is a more preferred embodiment.

As (meth) acrylic acid used in the present invention, it is preferable to use one having a water content of 1.0% by mass or less, particularly 0.1% by mass or less, in order to allow the production method of the present invention to proceed smoothly. .
The water content of the (meth) acrylic acid can be measured using a Karl Fischer moisture meter. Hereinafter, unless specifically defined, the water content and the water content are measured by the above methods.

As the polyhydric alcohol used in the present invention, any polyhydric alcohol having 3 or more alcoholic hydroxyl groups can be used, and preferably a polyhydric alcohol having 3 to 6 alcoholic hydroxyl groups.
Specifically, pentaerythritol, dipentaerythritol, tripentaerythritol, tris (2-hydroxyethyl) isocyanurate, trimethylolpropane, ditrimethylolpropane, polyoxyethylene and / or polyoxypropylene trimethylolpropane ether, polyoxy Examples include ethylene and / or polyoxypropylene pentaerythritol ether, polyoxyethylene and / or polyoxypropylene dipentaerythritol ether, and among these, pentaerythritol, dipentaerythritol, and tris (2-hydroxyethyl) isocyanurate are included. Preferably used.

The (meth) acrylic acid ester component having two target hydroxyl groups in the production method of the present invention is an esterification reaction between a polyhydric alcohol having three or more alcoholic hydroxyl groups as raw materials and (meth) acrylic acid. Means an ester body in which only some of the plurality of hydroxyl groups are esterified to leave two hydroxyl groups. In the esterification reaction, a complete ester body in which all the hydroxyl groups are esterified is obtained at the same time, and the content of the (meth) acrylic acid ester component having two hydroxyl groups is 15 to 50 masses relative to the total mass of the ester bodies. % (Meth) acrylic acid ester mixture.
The content of the (meth) acrylic acid ester component having two hydroxyl groups relative to the total mass of the ester can be measured using HPLC (high performance liquid chromatography). HPLC measurement conditions are appropriately set depending on the type of polyhydric alcohol used.

The first step of the present invention is a step of obtaining an intermediate mixture by an esterification reaction of (meth) acrylic acid and a polyhydric alcohol in the presence of an acid catalyst, and the reaction rate based on hydroxyl groups is 45%. The amount of water contained in the reaction solution is maintained at 0 to 12% by mass with respect to the total mass of the reaction solution excluding the organic solvent until the reaction rate reaches 45 to 65%. Is an esterification reaction step.
The proportion of (meth) acrylic acid and polyhydric alcohol used is preferably 0.5 to 1.5 mol of (meth) acrylic acid, more preferably 0 with respect to 1 mol in terms of hydroxyl group of polyhydric alcohol. .75 to 1.25 mol, most preferably 0.85 to 1.15 mol. Here, in terms of hydroxyl group conversion of the polyhydric alcohol, for example, in the case of a compound having 4 hydroxyl groups in one molecule, 1 mol of the compound corresponds to 4 mol in terms of hydroxyl group.

  Examples of the acid catalyst to be used include mineral acids such as sulfuric acid, and sulfonic acids such as p-toluenesulfonic acid, methanesulfonic acid and trifluoromethanesulfonic acid. Among these, sulfuric acid and p-toluenesulfonic acid are inexpensive. The resulting product is preferably used because it is less colored.

The esterification reaction can be performed without using an organic solvent, but water (condensed water) generated in the reaction solution as the esterification reaction proceeds is smoothly removed from the reaction solution, and the reaction rate is 45. In order to maintain the water content in the reaction solution at 0 to 12% by mass until reaching%, it is preferable to use an organic solvent.
Examples of organic solvents to be used include aromatic hydrocarbons such as toluene, benzene and xylene, aliphatic hydrocarbons such as hexane and heptane, and alicyclic hydrocarbons such as cyclohexane. You can also Of these, toluene, cyclohexane and n-heptane are preferred.
As for the usage-amount of an organic solvent, 10-75 mass% is preferable with respect to the total amount of the said (meth) acrylic acid and a polyhydric alcohol, More preferably, it is 15-55 mass%.

  The reaction temperature may be set according to the raw materials used, but is preferably 65 to 140 ° C, more preferably 75 to 120 ° C from the viewpoint of shortening the reaction time and preventing polymerization. The pressure during the reaction is not particularly limited and may be normal pressure or reduced pressure.

The reaction is preferably performed in the presence of oxygen to prevent polymerization, and a polymerization inhibitor is preferably added to the reaction solution for the purpose of preventing polymerization.
Examples of the polymerization inhibitor include organic compounds and metal salts, and examples of the organic compound include benzoquinone, hydroquinone, catechol, diphenylbenzoquinone, hydroquinone monomethyl ether, and the like. Examples of the metal salt include copper compounds such as cupric chloride and copper sulfate, and iron compounds such as ferrous sulfate.
The addition amount of the polymerization inhibitor is 10 to 50,000 ppm, preferably 100 to 10,000 ppm on a mass basis with respect to the amount of (meth) acrylic acid used as a raw material.

  The feature of the esterification reaction in the present invention is that the amount of water contained in the reaction solution is 0 to 0% of the total mass of the reaction solution components excluding the organic solvent until the reaction rate based on the hydroxyl group reaches 45%. It is to adjust to 12% by mass, and to stop the esterification reaction when the reaction rate is 45 to 65%.

The reaction rate is a value based on a hydroxyl group and is obtained by the following formula.
Reaction rate (%) = [(B−A) ÷ C] × 100
(A represents the acid value (mmol / g) of the reaction solution, B represents the charged acid value (mmol / g), and C represents the number of moles of the polyhydric alcohol used (mmol / g) × the number of hydroxyl groups of the polyhydric alcohol.)
The reaction solution acid value (A) and charged acid value (B) were prepared by dissolving a sample in acetone, adding 0.1% bromthymol blue solution as an indicator, and adding 0.2 mol / L potassium hydroxide / ethanol solution. The acid value was measured by potentiometric titration method

Until the reaction rate reaches 45%, if the water content in the reaction solution continues to exceed 12% by mass, the desired (meth) acrylic ester mixture cannot be obtained smoothly. Except for the very beginning of the reaction, the amount of water contained in the reaction solution is preferably 3 to 12% by mass, and more preferably 6 to 10% by mass. The “very early reaction stage” means a stage where the reaction rate is up to 20%.
When the reaction rate reaches 45%, the amount of water contained in the reaction solution is preferably 3 to 12% by mass with respect to the total mass of the reaction solution excluding the organic solvent, More preferably, it is 10 mass%.
By setting the water content of the reaction solution to 3 to 12% by mass, the polyhydric alcohol is dissolved even in a low reaction rate state, so that a partial ester body can be obtained at a high ratio.
If the water content is 3% by mass or more, the polyhydric alcohol dissolves from the stage where the reaction rate is low, so that the proportion of the higher order ester is difficult to increase, and if it is 0 to 12% by mass, the equilibrium returns to the raw material side. It is difficult for the esterification reaction to proceed.

The water produced by the esterification reaction can be balanced by distilling it out of the system together with an organic solvent as necessary so as to be in the above-mentioned water content range.
Specifically, for example, when the reaction liquid is at a predetermined temperature (T1), the external temperature (the temperature of the heating jacket or oil bath provided on the outer periphery of the container containing the reaction liquid) (T2) By adjusting the temperature difference (ΔT = T2−T1), the amount of water in the reaction solution can be controlled. When the temperature difference is reduced (when the external temperature is not increased too much), the amount of water in the reaction solution increases, and when the temperature difference is increased and heating from the outside of the reaction solution is increased, the amount of water in the reaction solution decreases.
The appropriate temperature difference between the reaction solution and the external temperature may vary depending on the situation, but generally when the reaction is carried out at a temperature difference of 3 to 50 ° C., particularly 5 to 30 ° C., the reaction rate is 45%. The water content can be smoothly controlled to 0 to 12% by mass.

  In the first step in the present invention, it is necessary to stop the esterification reaction when the reaction rate is 45 to 65%. When the reaction is stopped at a stage where the reaction rate is lower than 45%, the amount of (meth) acrylic acid ester having two hydroxyl groups obtained is small, and the amount of polyhydric alcohol remaining without dissolving in the reaction solution is large. . On the other hand, when the reaction is stopped at a stage where the reaction rate exceeds 65%, the amount of the completely esterified product increases, so that the proportion of (meth) acrylic acid ester having two hydroxyl groups decreases.

At the time of stopping the reaction, there are methods such as lowering the reaction temperature and neutralizing the used acid catalyst.
In the neutralization treatment of the acid catalyst, an alkaline aqueous solution diluted to 1 to 25% by mass can be generally used. Examples of the alkali component include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal salts such as sodium carbonate, and alkaline earth metal hydroxides such as calcium hydroxide. Among these, alkali metals Hydroxides are preferred because of their excellent neutralizing effect.
The amount of the alkali component in the aqueous alkali solution added in the catalyst neutralization treatment is preferably 0.5 to 5 times in molar ratio to the acid catalyst used in the reaction.

  In the second step of the present invention, an organic solvent is added to the intermediate mixture obtained in the first step, neutralized with an aqueous alkaline solution, and water in the organic phase separated from the aqueous phase after the neutralization treatment. It is the neutralization process process whose quantity is 1-10 mass% with respect to the total mass of an organic phase. Depending on the case, you may perform the water washing and saponification etc. which are mentioned later.

In the second step, the water content in the organic phase after the neutralization treatment needs to be 1 to 10% by mass with respect to the total mass of the organic phase, and preferably the water content in the organic phase is 3 to 3. 7% by mass. By setting the water content within this range, distribution of the partial ester body to the aqueous phase is suppressed, so that the proportion of the partial ester body in the organic phase can be increased.
When the water content is lower than 1% by mass, a partial ester body such as (meth) acrylic acid ester having two hydroxyl groups is distributed to the aqueous phase, and when it exceeds 10% by mass, the organic phase and the aqueous phase are mixed. There is a risk that liquid-liquid separation becomes difficult.

In order to adjust the water content in the organic phase to 1 to 10% by mass, it is important to select an organic solvent to be diluted.
Although there is no limitation in particular in the organic solvent to be used, It is preferable to use the organic solvent containing 30-100 mass% of compounds whose octanol-water partition coefficient (logPow) in 25 degreeC is -1-2.
Examples of the compound in which logPow at 25 ° C. is −1 to 2 (the numbers in parentheses indicate logPow at 25 ° C.) include ethylene glycol monomethyl ether (−0.77), ethylene glycol dimethyl ether (−0.21), Propylene glycol monomethyl ether (−0.49), acetone (−0.24), isopropyl alcohol (0.05), methyl ethyl ketone (0.29), n-butyl alcohol (0.90), isobutyl alcohol (0.76) ), S-butyl alcohol (0.60), t-butyl alcohol (0.37), ethyl acetate (0.73), propyl acetate (1.24), and butyl acetate (1.82). Of these, methyl ethyl ketone, ethyl acetate and propyl acetate are preferred.
The amount of the organic solvent to be diluted is preferably 30 to 200 parts by mass with respect to 100 parts by mass of the reaction solution.

After the above organic solvent is added to the reaction solution, or at the same time, neutralization is performed with an alkaline aqueous solution. As the alkaline component of the alkaline aqueous solution, generally an alkaline aqueous solution diluted to 1 to 25% by mass can be used. Examples of the alkali component include alkali metal hydroxides such as sodium hydroxide and potassium hydroxide, alkali metal salts such as sodium carbonate, and alkaline earth metal hydroxides such as calcium hydroxide. Among these, alkali metals Hydroxides are preferred because of their excellent neutralizing effect.
The amount of the alkali component in the aqueous alkali solution added in the neutralization treatment step is preferably 1 or more, more preferably 1.0 to 1.6 times in terms of molar ratio with respect to the acid content of the reaction solution. .

Next, the neutralized reaction solution is washed with water as necessary. The water washing treatment is not limited after neutralization, and may be performed before neutralization or may be performed both before and after neutralization. As water used for the water washing treatment, it is preferable to use distilled water, purified water or the like, and the water washing treatment may be performed only once or a plurality of times.
By washing with water, neutralized acid catalyst and unreacted (meth) acrylic acid salt contained in the reaction solution, or non-salt catalyst and unreacted (meth) acrylic acid are contained in the aqueous phase. To be removed from the organic phase.

  The reaction solution after neutralization and washing with water is allowed to stand, and after separating into a lower layer composed of an aqueous phase and an upper layer composed of an organic solvent solution, the upper organic phase is separated, and the organic solvent is distilled off. And the (meth) acrylic acid ester component which has two target hydroxyl groups is 15-50 mass% of the whole ester body, and acquires the (meth) acrylic acid ester mixture. In general, the distillation treatment is preferably performed by heating under reduced pressure. When the pressure is 0.1 to 80 kPa and the temperature is about 40 to 120 ° C., the target (meth) acrylic ester mixture is obtained. It can be obtained smoothly.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to an Example. Unless otherwise specified, parts represent parts by mass, and% represents mass%.
(1) Reaction rate:
The acid value (prepared acid value) of the reaction liquid at the start of the reaction and the acid value of the reaction liquid at each reaction time were measured by titration, and the reaction rate (%) was determined from the following formula (1).
Reaction rate (%) = [(BA) ÷ C] × 100 (1)
A: Reaction solution acid value (mmol / g)
B: Charged acid value (mmol / g)
C: number of moles of polyhydric alcohol used (mmol / g) × number of hydroxyl groups of polyhydric alcohol

(2) Moisture content contained in the reaction solution The moisture content (%) contained in the reaction solution was measured with a Karl Fischer moisture meter, and the amount (%) of the organic solvent contained in the reaction solution was measured by gas chromatography. Thus, the amount of water (%) contained in the reaction solution was determined from the following formula (2).
Water content (%) = {D / (100-E)} × 100 (2)
D: amount of water in the reaction solution (%), E: amount of organic solvent contained in the reaction solution (%)

(3) Water content in organic phase after neutralization The water content (%) in the organic phase was measured with a Karl Fischer moisture meter.

(4) Ratio of acrylate component It analyzed with the HPLC apparatus.
Pentaerythritol, tris (2-hydroxyethyl) isocyanurate
Device: LC10AD manufactured by Shimadzu Corporation
Column; Sunfire C18
Column temperature: 40 ° C
Eluent: 0.015% phosphoric acid aqueous solution / methanol detector; UV 210 nm
Dipentaerythritol device; LC10AD manufactured by Shimadzu Corporation
Column; Inertsil ODS-2
Column temperature: 40 ° C
Eluent: 0.015% phosphoric acid aqueous solution / methanol detector; UV 210 nm

Example 1
(First step)
Acrylic acid (1,317 parts, 18.3 moles: number of moles calculated with parts as g, the same shall apply hereinafter), pentaerythritol (manufactured by Guangei Chemical Co., Ltd., hereinafter referred to as “PET”) (732 parts, 5 .4 mol), 78% sulfuric acid (31 parts), cupric chloride (3 parts), toluene (980 parts), and a reaction temperature of about 80 ° C., an external temperature of 87 ° C., an internal / external temperature difference ΔT of 7 ° C., and 50 kPa ( The reaction was carried out to a reaction rate of 64% while the condensed water was distilled off under the condition of (absolute pressure). The amount of water contained in the reaction solution at a reaction rate of 45% was 3.7%. The total amount of water distilled off after the reaction was stopped was 250 parts, and 2,647 parts were obtained as a synthesis solution. All the PET was dissolved at a reaction rate of 63%, and no filtration operation was required.
(Second step)
After putting the synthesis solution (2,647 parts) into a separatory funnel, adding ethyl acetate (1,853 parts) and further ion-exchanged water (hereinafter simply referred to as “water”) (1,350 parts), and mixing, Liquid-liquid separation was performed by standing, the lower layer was extracted, and the organic phase was separated. Subsequently, an equimolar amount of a 20% aqueous sodium hydroxide solution (1,820 parts) with respect to the acid content of the organic phase was added with stirring to carry out a neutralization treatment. The water content of the organic phase after the neutralization treatment was 2.2%. The organic phase was separated and washed with water. After washing with water, the organic phase was again separated and heated under reduced pressure to distill off the solvent.
The acrylate mixture obtained after distilling off the solvent was 1270 parts, and the hydroxyl value was 195 mgKOH / g. The ratio when the acrylate component in the mixture was 100% was PET monoacrylate 1%, diacrylate 19%, triacrylate 55%, and tetraacrylate 25%.

Example 2
(First step)
Acrylic acid (1,440 parts, 20 moles), PET (732 parts, 5.4 moles), p-toluenesulfonic acid (33 parts), cupric chloride (4 parts), cyclohexane (350 parts), n- Heptane (40 parts) was mixed and reacted to a reaction rate of 62% while removing condensed water under the conditions of a reaction temperature of about 80 ° C., an external temperature of 93 ° C., an internal / external temperature difference ΔT of 12 ° C., and 93 kPa (absolute pressure). After cooling, a 20% aqueous sodium hydroxide solution (36 parts) was added to neutralize the strong acid catalyst. The amount of water contained in the reaction solution at a reaction rate of 45% was 4.7%. The total amount of water distilled off after the reaction was stopped was 220 parts, and 2415 parts were obtained as a synthesis solution. All the PET was dissolved at a reaction rate of 62%, and no filtration operation was required.
(Second step)
Put the synthesis liquid (2,415 parts) in a separatory funnel, then add cyclohexane (248 parts), methyl ethyl ketone (2,400 parts), and water (1,710 parts) and mix, and then leave the liquid Separation was performed and the lower layer was extracted to separate the organic phase. Subsequently, an equimolar amount of 20% aqueous sodium hydroxide solution (1,060 parts) was added with stirring to the acid content of the organic phase to carry out neutralization treatment. The water content of the organic phase after the neutralization treatment was 4.2%. The organic phase was separated and washed with water. After washing with water, the organic phase was again separated and heated under reduced pressure to distill off the solvent.
The obtained acrylate mixture was 1,160 parts and the hydroxyl value was 208 mgKOH / g. The ratio when the acrylate component in the mixture was 100% was PET monoacrylate 1%, diacrylate 20%, triacrylate 50%, and tetraacrylate 29%.

Example 3
(First step)
Acrylic acid (1,163 parts, 16.2 moles), PET (732 parts, 5.4 moles), p-toluenesulfonic acid (29 parts), cupric chloride (4 parts) are mixed, and the reaction temperature is about The reaction was carried out to a reaction rate of 48% without removing condensed water under the conditions of 90 ° C., external temperature 102 ° C., internal / external temperature difference ΔT 12 ° C., and 101 kPa (absolute pressure). After cooling, a 20% aqueous sodium hydroxide solution (32 parts) was added to neutralize the strong acid catalyst. The amount of water contained in the reaction solution at a reaction rate of 45% was 9.8%. As a synthesis solution, 1,959 parts were obtained. All the PET was dissolved at a reaction rate of 40%, and no filtration operation was required.
(Second step)
Add the synthesis solution (1,959 parts) to the separatory funnel, then add cyclohexane (600 parts), methyl ethyl ketone (2,400 parts), and water (1,250 parts), mix, and leave the liquid to stand. Separation was performed and the lower layer was extracted to separate the organic phase. Next, an equimolar amount of 20% aqueous sodium hydroxide solution (840 parts) was added with stirring to the acid content of the organic phase, and neutralization was carried out. The water content of the organic phase after the neutralization treatment was 5.4%. The organic phase was separated and washed with water. After washing with water, the organic phase was again separated and heated under reduced pressure to distill off the solvent.
The obtained acrylate mixture was 874 parts, and the hydroxyl value was 280 mgKOH / g. The ratio when the acrylate component in the mixture was 100% was PET monoacrylate 2%, diacrylate 36%, triacrylate 48%, and tetraacrylate 14%.

Example 4
(First step)
The same operation as in Example 2 was performed.
(Second step)
Add the synthesis solution (2,415 parts) to the separatory funnel, then add cyclohexane (848 parts), methyl ethyl ketone (1,800 parts), and water (1,710 parts), mix, and leave the liquid Separation was performed and the lower layer was extracted to separate the organic phase. Subsequently, an equimolar amount of a 20% aqueous sodium hydroxide solution (910 parts) was added with stirring to the acid content of the organic phase to carry out a neutralization treatment. The water content of the organic phase after the neutralization treatment was 2.5%. The organic phase was separated and washed with water. After washing with water, the organic phase was again separated and heated under reduced pressure to distill off the solvent.
The obtained acrylate mixture was 1,010 parts and the hydroxyl value was 181 mgKOH / g. The ratio when the acrylate component in the mixture was 100% was 17% PET diacrylate, 52% triacrylate, and 31% tetraacrylate.

Example 5
(First step)
Acrylic acid (755 parts, 10.5 mol), isocyanuric acid tris (2-hydroxyethyl) [manufactured by Shikoku Kasei Kogyo Co., Ltd., hereinafter referred to as “THEIC”] (1,217 parts, 6.1 mol), p -Toluenesulfonic acid (25 parts) and cupric chloride (3 parts) are mixed, and condensed water is removed under conditions of a reaction temperature of about 90 ° C, an external temperature of 102 ° C, an internal / external temperature difference of ΔT12 ° C, and 101 kPa (absolute pressure). Without reaction, the reaction was allowed to proceed to 48%. After cooling, a 20% aqueous sodium hydroxide solution (28 parts) was added to neutralize the strong acid catalyst. The amount of water contained in the reaction solution at a reaction rate of 45% was 6.1%. As a synthesis solution, 2,028 parts were obtained. THEIC was dissolved at a reaction rate of 35%, and filtration was not necessary.
(Second step)
Put the synthesis liquid (2,028 parts) in a separatory funnel, then add cyclohexane (600 parts), methyl ethyl ketone (2,400 parts), and water (1,250 parts), mix, and leave the liquid to stand. Separation was performed and the lower layer was extracted to separate the organic phase. Next, an equimolar amount of a 20% aqueous sodium hydroxide solution (690 parts) was added with stirring to the acid content of the organic phase to carry out a neutralization treatment. The water content of the organic phase after the neutralization treatment was 3.8%. The organic phase was separated and washed with water. After washing with water, the organic phase was again separated and heated under reduced pressure to distill off the solvent.
The obtained acrylate mixture was 800 parts, and the hydroxyl value was 260 mgKOH / g. The ratio when the acrylate component in the mixture was 100% was 38% of THEIC monoacrylate, 42% diacrylate, and 20% triacrylate.

Example 6
(First step)
Acrylic acid (1,193 parts, 16.5 mol), dipentaerythritol [manufactured by Guangei Chemical Industry Co., Ltd., hereinafter referred to as “DPET”] (779 parts, 3.1 mol), p-toluenesulfonic acid (25 Part) and cupric chloride (3 parts) are mixed, and the reaction rate is obtained without removing condensed water under the conditions of reaction temperature of about 90 ° C., external temperature of 102 ° C., internal / external temperature difference ΔT 12 ° C., and 101 kPa (absolute pressure). The reaction was allowed to reach 60%. After cooling, a 20% aqueous sodium hydroxide solution (28 parts) was added to neutralize the strong acid catalyst. The amount of water contained in the reaction solution at a reaction rate of 45% was 8.3%. As a synthesis solution, 2,028 parts were obtained. DPET was completely dissolved at a reaction rate of 59%, and no filtration operation was required.
(Second step)
Put the synthesis liquid (2,028 parts) in a separatory funnel, then add cyclohexane (600 parts), methyl ethyl ketone (2,400 parts), and water (1,250 parts), mix, and leave the liquid to stand. Separation was performed and the lower layer was extracted to separate the organic phase. Next, an equimolar amount of 20% aqueous sodium hydroxide solution (994 parts) was added with stirring to the acid content of the organic phase to carry out neutralization treatment. The water content of the organic phase after the neutralization treatment was 3.2%. The organic phase was separated and washed with water. After washing with water, the organic phase was again separated and heated under reduced pressure to distill off the solvent.
The obtained acrylate mixture was 897 parts, and the hydroxyl value was 212 mgKOH / g. When the acrylate component in the mixture was 100%, the ratio of DPET triacrylate was 27%, tetraacrylate was 28%, pentaacrylate was 34%, and hexaacrylate was 12%.

Comparative Example 1
(First step)
The synthesis was carried out in the same manner as in Example 1 except that the reaction temperature was about 80 ° C., the external temperature was 100 ° C., and the internal / external temperature difference ΔT was 20 ° C. The amount of water contained in the reaction solution at a reaction rate of 45% was 0.7%. The total amount of water distilled off after the reaction was stopped was 220 parts, and PET was not dissolved when the reaction was stopped and the PET recovered by filtration was 73 parts. As a synthesis solution, 2,677 parts were obtained.
(Second step)
The same treatment as in Example 1 was performed except that the organic solvent to be diluted was diluted with toluene (1,490 parts) instead of ethyl acetate. The water content of the organic phase after the neutralization treatment was 0.7%. The organic phase was separated and washed with water. After washing with water, the organic phase was again separated and heated under reduced pressure to distill off the solvent.
The obtained acrylate mixture was 950 parts, and the hydroxyl value was 155 mgKOH / g. When the acrylate component in the mixture was 100%, the ratio was 12% PET diacrylate, 60% triacrylate, and 28% tetraacrylate.

Comparative Example 2
(First step)
The same operation as in Example 2 was performed.
(Second step)
Put the synthesis solution (2,394 parts) in the separatory funnel, then add cyclohexane (1,110 parts), methyl ethyl ketone (1,500 parts), and water (1,710 parts), and mix. Liquid-liquid separation was performed, the lower layer was extracted, and the organic phase was separated. Next, an equimolar amount of 20% aqueous sodium hydroxide solution (810 parts) was added with stirring to the acid content of the organic phase to carry out neutralization treatment. The water content of the organic phase after the neutralization treatment was 0.9%. The organic phase was separated and washed with water. After washing with water, the organic phase was again separated and heated under reduced pressure to distill off the solvent.
The obtained acrylate mixture was 982 parts and the hydroxyl value was 142 mgKOH / g. The ratio when the acrylate component in the mixture was 100% was 8% PET diacrylate, 50% triacrylate, and 42% tetraacrylate.

Comparative Example 3
(First step)
The synthesis was performed in the same manner as in Example 2 except that the reaction temperature was about 80 ° C., the external temperature was 100 ° C., and the internal / external temperature difference ΔT was 20 ° C., and the reaction was continued until all the PET was dissolved. After cooling, a 20% aqueous sodium hydroxide solution (36 parts) was added to neutralize the strong acid catalyst. The amount of water contained in the reaction solution at a reaction rate of 45% was 0.3%. The reaction rate when the reaction was stopped was 68%, and the total amount of distilled water was 241 parts, and 2,394 parts were obtained as a synthesis solution. Since PET was dissolved, no filtration operation was necessary.
(Second step)
Add the synthesis solution (2,379 parts) to the separatory funnel, then add cyclohexane (248 parts), methyl ethyl ketone (2,400 parts), and water (1,710 parts), mix, and leave the liquid Separation was performed and the lower layer was extracted to separate the organic phase. Next, an equimolar amount of a 20% aqueous sodium hydroxide solution (1,250 parts) was added with stirring to the acid content of the organic phase to carry out a neutralization treatment. The water content of the organic phase after the neutralization treatment was 4.2%. The organic phase was separated and washed with water. After washing with water, the organic phase was again separated and heated under reduced pressure to distill off the solvent.
The obtained acrylate mixture was 1,360 parts and the hydroxyl value was 162 mgKOH / g. The ratio when the acrylate component in the mixture was 100% was PET monoacrylate 1%, diacrylate 14%, triacrylate 52%, and tetraacrylate 33%.

Comparative Example 4
(First step)
The same operation as in Example 2 was performed.
(Second step)
Add the synthesis solution (2,379 parts) to the separatory funnel, then add cyclohexane (248 parts), acetone (2,400 parts), and water (1,710 parts), mix, and leave the liquid to stand. Separation was performed and the lower layer was extracted to separate the organic phase. Next, an equimolar amount of a 20% aqueous sodium hydroxide solution (1,200 parts) was added with stirring to the acid content of the organic phase to carry out neutralization treatment. The water content of the organic phase after the neutralization treatment was 13%. The organic phase was separated and washed with water, but the organic phase and the aqueous phase were mixed and the organic phase could not be taken out.

Comparative Example 5
(First step)
The same operation as in Example 2 was performed.
(Second step)
The same treatment as in Example 2 was performed except that dilute with cyclohexane (2,648 parts) instead of the mixed solvent of cyclohexane and methyl ethyl ketone. The water content of the organic phase after the neutralization treatment was 0.1%. The organic phase was separated and washed with water. After washing with water, the organic phase was again separated and heated under reduced pressure to distill off the solvent.
The resulting acrylate mixture was 512 parts and the hydroxyl value was 77 mgKOH / g. The ratio when the acrylate component in the mixture was 100% was 41% PET triacrylate and 59% tetraacrylate.

Comparative Example 6
(First step)
The reaction was carried out in the same manner as in Example 2 up to a reaction rate of 43%. After cooling, 20% aqueous sodium hydroxide solution (36 parts) was added to neutralize the catalyst. The amount of water contained in the reaction solution at a reaction rate of 43% was 4.7%. The total amount of water distilled off after the reaction was stopped was 155 parts, and PET was not dissolved when the reaction was stopped, and the amount of PET recovered by filtration was 302 parts. As a synthesis solution, 2179 parts were obtained.
(Second step)
Add the synthesis solution (2,179 parts) to the separatory funnel, then add cyclohexane (248 parts), methyl ethyl ketone (2,400 parts), and water (1,710 parts), mix, and leave the liquid Separation was performed and the lower layer was extracted to separate the organic phase. Subsequently, an equimolar amount of 20% aqueous sodium hydroxide solution (1,060 parts) was added with stirring to the acid content of the organic phase to carry out neutralization treatment. The water content of the organic phase after the neutralization treatment was 4.8%. The organic phase was separated and washed with water. After washing with water, the organic phase was again separated and heated under reduced pressure to distill off the solvent.
The obtained acrylate mixture was 684 parts and the hydroxyl value was 265 mgKOH / g. The ratio when the acrylate component in the mixture was 100% was PET monoacrylate 2%, diacrylate 35%, triacrylate 48%, and tetraacrylate 15%.

  The (meth) acrylic acid ester mixture obtained by the production method of the present invention has a high proportion of partial ester bodies having two types of functional groups of hydroxyl group and unsaturated bond in one molecule. It can be used effectively not only in the resist field, but also as a raw material for urethane acrylate.

Claims (6)

The following 1st process and 2nd process are included, Content of the (meth) acrylic acid ester component which has two hydroxyl groups is 15-50 mass% with respect to the total mass of an ester body, It is characterized by the above-mentioned.
A method for producing a (meth) acrylic acid ester mixture.
First step:
In the presence of an acid catalyst, an intermediate mixture is obtained by esterification reaction of (meth) acrylic acid and a polyhydric alcohol, and the reaction solution is mixed until the reaction rate based on hydroxyl groups reaches 45%. The amount of water contained is maintained at 12% by mass or less with respect to the total mass of the reaction liquid excluding the organic solvent, and the esterification reaction step is stopped when the reaction rate is 45 to 65%. Two steps:
To the intermediate mixture obtained in the first step, an organic solvent is added, neutralized with an aqueous alkali solution, and the water content in the organic phase separated from the aqueous phase after the neutralization is the total mass of the organic phase. The neutralization process which is 1-10 mass% with respect to   In the first step, when the reaction rate reaches 45%, the amount of water contained in the reaction solution is 6 to 10% by mass with respect to the total mass of the reaction solution excluding the organic solvent. 2. A method for producing a (meth) acrylic acid ester mixture according to 1.   The manufacturing method of the (meth) acrylic acid ester mixture of Claim 1 or Claim 2 whose water content in the said organic phase is 3-7 mass% with respect to the total mass of an organic phase.   The organic solvent in a 2nd process contains 30 mass% or more of compounds whose octanol-water partition coefficient (logPow) in 25 degreeC is -1-2 with respect to the total mass of an organic solvent. The manufacturing method of the (meth) acrylic acid ester mixture of any one of these.   The manufacturing method of the (meth) acrylic acid ester mixture of any one of Claims 1-4 whose said polyhydric alcohol is pentaerythritol, dipentaerythritol, or isocyanuric acid tris (2-hydroxyethyl).   The organic solvent in the second step contains at least one selected from the group consisting of methyl ethyl ketone, ethyl acetate and propyl acetate in an amount of 30% by mass or more based on the total mass of the organic solvent. The manufacturing method of the (meth) acrylic acid ester mixture of 1 item | term.