KR0156259B1 - Preparation of triglycidyl isocyanurate - Google Patents

Abstract

The present invention relates to a method for preparing triglycidyl isocyanurate (hereinafter referred to as TGI) from isocyanuric acid (hereinafter referred to as ICA) and epichlorohydrin (hereinafter referred to as EpCH).

Description

Method for preparing triglycidyl isocyanurate

The present invention relates to a method for preparing triglycidyl isocyanurate (hereinafter referred to as TGI) from isocyanuric acid (hereinafter referred to as ICA) and epichlorohydrin (hereinafter referred to as EpCH).

TGI is a useful material for curing and modifying polyester powder coatings.

Methods for producing TGI from ICA and EpCH are described in US Pat. Nos. 2,809,942 and 3,547,918, Japanese Patent Publication No. 42-1989, and the like. It is divided into stages of dehydrochlorination.

[Additional reaction]

ICA + EpCH →

Mono (3-chloro-2-hydroxypropyl) isocyanurate (1)

(1) + EpCH →

Bis (3-chloro-2-hydroxypropyl) isocyanurate (2)

(2) + EpCH →

Tris (3-chloro-2-hydroxypropyl) isocyanurate (3)

(3) + EpCH →

Bis (3-chloro-2-hydroxypropyl) -mono- (2,3-epoxypropyl)

Isocyanurate (4) + dichloropropanol (6)

(4) + EpCH →

Mono (3-chloro-2-hydroxypropyl) -bis- (2,3-epoxypropyl)

Isocyanurate (5) + (6)

(5) + EpCH → TGI + (6)

[Dehydrogen chloride reaction (when the basic substance is NaOH)]

(3) + NaOH → (4) + NaOH + H ₂ O

(4) + NaOH → (5) + NaOH + H ₂ O

(5) + NaOH → TGI + NaOH + H ₂ O

(6) + NaOH → EpCH + NaOH + H ₂ O

In the addition reaction, ICA and EpCH are sequentially reacted in the presence of a catalyst to mainly produce (3). In this reaction, however, mainly part of (3) reacts again with excess EpCH to produce epoxypropyl isocyanurates. Thus, a mixture of isocyanurates in which mainly (3) and some or all of its 3-chloro-2-hydroxypropyl groups are substituted with 2,3-epoxypropyl groups is produced.

By dehydrochlorination, the 3-chloro-2-hydroxypropyl group becomes a 2,3-epoxypropyl group to produce TGI. In this reaction, (6) is also reacted to regenerate EpCH.

The conventionally proposed method for producing TGI has a problem that, when carried out on an industrial scale, the yield is low, the reaction time is long, or high purity TGI is not obtained. Japanese Patent Publication Nos. 53-28,916 and 53-28,917 describe 6-24 moles of EpCH, 0.001-0.2 moles of catalyst and 0.2-12 for ICA and ICA to solve the above problems. A method of carrying out addition reaction while raising the temperature of an addition reaction liquid is proposed by coexisting and heating water of a double mole, and azeotropically removing water with EpCH.

Based on the above-mentioned Japanese Patent Publication Nos. 53-28,916 and 53-28,917, the inventors examined the production on the industrial scale of TGI and confirmed the following problems.

(1) The above-described patent describes that the time for dissolving and reacting ICA is shortened by adding water to the reaction system, and the pure TGI yield is increased. However, in this embodiment, since the catalyst is added all at once and the reaction heat of the addition reaction is increased, a dolby phenomenon tends to occur when a sudden reaction occurs. For this reason, since temperature control of a reaction liquid is difficult and it is necessary to raise reaction temperature gradually and to perform an addition reaction, it requires a lot of time. Although a method of releasing heat while circulating the reaction liquid is also considered, in this case, energy consumption increases.

(2) When a large amount of water is used, it takes a lot of time to drain the water. In addition, as a result of the time required for (1), since the amount of side reactions is increased, the purity of crude TGI is low, and the yield of pure TGI is not necessarily industrially satisfactory.

An object of the present invention is to develop an industrial manufacturing method for efficiently obtaining TGI from ICA and EpCH in high yield.

As a result of earnestly examining the industrial scale production of TGI having the above-mentioned problems, the inventors have found that when the catalyst solution is added dropwise to the ICA and the EpCH solution as raw materials, the temperature of the reaction solution can be easily controlled. The present invention has been found that the TGI yield is remarkably improved when methanol is coexisted with water together.

That is, the present invention performs the addition reaction of ICA and EpCH in the presence of a catalyst selected from the group consisting of quaternary ammonium hydroxides and quaternary ammonium halides, and then dehydrohydrogenates this reaction product to produce TGI. In the addition reaction step, a catalyst solution is added dropwise to a solution of ICA and EpCH to react in the presence of methanol and water, and after completion of the dropwise addition, the reaction temperature is increased by distilling off methanol and water, thereby producing a TGI.

Examples of catalysts used in the present invention include quaternary ammonium hydroxides such as trimethyl benzyl ammonium hydroxide, quaternary ammonium halides such as tetramethyl ammonium chloride, tetraethyl ammonium bromide, but especially tetramethyl ammonium chloride Quaternary ammonium halides such as these are very suitable.

The amount of the catalyst used is 0.001-0.2 times mole relative to the ICA of the raw material.

When the amount of the catalyst is too small, the reaction is slowed, and when too much, the amount of side reactions such as polymerization of EpCH increases.

The amount of EpCH used is 6-30 times mole, preferably 12-24 times mole relative to ICA. When the amount of EpCH is too small, the TGI yield is lowered. When the amount of EpCH is too large, it is not preferable because the volume of the reactor needs to be increased.

The amount of water added is 0.01-12 times mole, preferably 0.01-2 times mole, relative to ICA, and the amount of methanol is 1-10 times mole, preferably 2-5 times mole, relative to ICA. When the addition amount of water and methanol is too small, the TGI yield falls, and when too much, it takes a lot of time for the outflow and removal of water and methanol.

In the present invention, the addition reaction is carried out while the catalyst liquid is added dropwise. In addition, this reaction needs to carry out ICA and EpCH in the presence of water and methanol. Therefore, a method using a solvent selected from the group consisting of water, methanol, and EpCH is used as the catalyst solution, and a method in which the catalyst solution is added dropwise to a slurry solution selected from the group consisting of ICA, EpCH, water, and methanol heated to a predetermined temperature. . By this method, reaction temperature can be easily controlled and addition reaction can be performed in a short time.

The addition reaction is usually performed under normal pressure, but can also be performed under pressure. The temperature of the addition reaction carried out dropwisely with the catalyst liquid depends on the amount of water and methanol added, but is usually about 85 ° C. under normal pressure.

The dropwise addition of the catalyst liquid needs to be carried out gradually so that the reaction liquid does not rush under reflux. After completion of the dropwise addition of the catalyst liquid, the entire reflux is stopped to discharge the effluent out of the system to distill water and methanol. Since the effluent is accompanied with EpCH together with water and methanol, it is preferable to sequentially replenish EpCH corresponding to the amount of EpCH selected to promote the addition reaction. This replenishment of EpCH is effective for maintaining a high EpCH / ICA molar ratio at the time of addition reaction without lowering the volumetric efficiency of the reactor, thereby obtaining a high TGI yield. The reaction temperature rises with the distillation of water and methanol, but once it reaches 110-120 ° C, it is aged at full reflux and the addition reaction process is completed. The reaction time of the addition reaction process also depends on the outflow rate of methanol and water, but usually 30-120 minutes is sufficient.

The product obtained by the addition reaction is mainly tris (3-chloro-2-hydroxypropyl) isocyanurate of (3) in the above reaction scheme, which is dehydrogenated with a basic compound to give crude TGI.

In the dehydrogen chloride process, for example, after completion of the addition reaction, the reaction solution is maintained at 10-50 ° C, and the alkali metal compound is slowly added to the raw material ICA at 3-4 times molar and reacted, and then the water layer is separated and the organic layer is separated. EpCH was distilled off, or the addition reaction termination solution was maintained at 10-50 ° C., and the alkali metal compound was slowly added to the raw material ICA at 3-4 times the molar amount under reduced pressure of 10-80 mmHg, and the water produced in the reaction was removed. Is reacted while removing azeotropically with EpCH, followed by desalting by adding water, and distilling EpCH from the organic layer obtained.

As an alkali metal compound used for this reaction, powdered, granular, flake shaped sodium hydroxide, or about 40 wt% of sodium hydroxide aqueous solution is usually used. When the alkali metal compound is added under reduced pressure, the reaction is performed while blowing gas such as meat or nitrogen at about 1 Nm ³ / min per ICA mole, which shortens the time required for the dehydrogenation reaction and improves the TGI yield.

In addition, when the EpCH is removed from the organic layer by the dehydrochlorination process, the temperature of the liquid is lower than 90 ° C, preferably lower than 70 ° C. If the temperature of the liquid is higher than 90 ° C, the produced TGI is deteriorated and the yield decreases.

The crude TGI obtained after the EpCH distillation adds a suitable solvent, such as methanol, and is cooled, crystallized, and filtered after heating and stirring to obtain high purity EpCH.

According to the method of the present invention, addition reaction of ICA and EpCH can be easily performed in a short time, and high TGI yield can be obtained. As a result, an efficient TGI manufacturing process is established, so the industrial significance of the present invention is great.

The present invention will be described in more detail with reference to the following examples.

However, the invention is not limited by these examples.

Example 1

In a 1 L flask attached with a stirrer, thermometer, cooler and dropping rod, EpCH 786g (8.5 mol), ICA64.7g (0.5 mol) and 45 g (1.4 mol) methanol were heated in an oil bath until reflux started. The temperature of the liquid at this time was about 85 degreeC.

Separately, a catalyst solution in which 3.7 g (0.034 mole) of tetramethyl ammonium chloride was dissolved in 1.4 g (0.08 mole) of water, 11 g (0.34 mole) of methanol, and 116 g (1.25 mole) of EpCH was prepared. The reaction solution was slowly added to avoid dolby.

After completion of the addition, the whole reflux was stopped to discharge the effluent out of the system, and EpCH was added to the amount of the effluent, and the temperature of the liquid was increased.

When the temperature of the liquid reached 116 ° C. over about 20 minutes, the mixture was further refluxed and aged for 15 minutes, and then cooled to dehydrogenate. When the obtained reaction liquid was analyzed by liquid chromatography, the addition reaction achievement rate was 84.0%.

In addition, the addition reaction achievement rate is represented by following Formula.

Where (1) is mono (3-chloro-2-hydroxypropyl) isocyanurate of the above-described scheme, (2) bis (3-chloro-2-hydroxypropyl) isocyanurate, (7) Is the unreacted ICA.

Next, a flask containing 65.4 g of 95% pure sodium hydroxide with a purity of 95% granularity was attached to the flask used in the above addition reaction, maintaining the system pressure at 30 mmHg and the temperature of the liquid at 30-35 ° C, and stirring well. Sodium hydroxide was partitioned into 6 portions and slowly added over 1 hour. The water produced in the reaction was discharged out of the system by azeotroping with EpCH.

After the addition of sodium hydroxide, aging was carried out again for 50 minutes.

260 g of water was added to the reaction product to dissolve the salt and separated into two layers. The organic layer was transferred to a separating rod and washed twice with 120 g of water, and then 133.7 g of crude TGI was obtained by distilling EpCH so that the temperature of the liquid did not exceed 60 ° C under reduced pressure.

Analysis of this crude TGI revealed a TGI of 127.4 g and a yield of 85.8% for the added ICA.

Example 2

The same procedure as in Example 1 was conducted except that 13.5 g (0.75 mol) of water in the catalyst solution was used. As a result, the time until the temperature of the liquid reached 116 ° C was 30 minutes, and the addition reaction achievement rate was 83.8 mol% in the analysis of the reaction liquid. 135.6 g of crude TGI after dehydrogen chloride was obtained, of which 126.8 g of TGI was contained, and the yield for the added ICA was 85.4%.

Comparative Example 1

In a 1 liter flask equipped with a stirrer, thermometer and cooler, 902 g (9.75 mol) of EpCH, 64.7 g (0.5 mol) of ICA, 1.4 g (0.08 mol) of water, and 3.7 g (0.034 mol) of tetramethyl ammonium chloride were added to the tank. Heated. At about 30 minutes the temperature of the liquid was brought to 90 ° C. and the outflow started. While removing the effluent, the temperature of the liquid was raised to 120 ° C. over 15 minutes while adding EpCH appropriate to the amount of effluent. Aged at this temperature for 20 minutes and then cooled. As a result of analyzing this reaction liquid, the addition reaction achievement rate was 76.2%. In the same manner as in Example 1, crude TGI 126.4 g was obtained. Among them, 106.3g of TGI was contained, and the yield for the added ICA was 71.6%.

Comparative Example 2

It carried out similarly to the comparative example 1 by making water into 13.5 g, (0.75 mol). As a result, the time until the temperature of the liquid reached 120 ° C. was 25 minutes, and the addition reaction achievement rate was 78.9%. 125.9 g of crude TGI after dehydrogen chloride was obtained, of which 109.9 g of TGI was contained, and the yield for the added ICA was 74.0%.

Example 3

In Example 1, it carried out similarly except having blown in 0.2NL of air every minute at the time of dehydrogenation reaction. As a result, the aging time in the dehydrochlorination reaction was 20 minutes, 140.2 g of crude TGI was obtained, 132.0 g of TGI was contained therein, and the yield for the added ICA was 88.8%.

Comparative Example 3

In Example 1, the temperature of the liquid at the time of distilling EpCH from the organic layer obtained by adding water to the reaction product of a dehydrogen chloride process and desalting was made into 90 degreeC. As a result, 133.0 g of crude TGI was obtained, of which 121.8 g of TGI was contained, and the yield for the added ICA was 82.0%.

Example 4

In Example 1, during the dehydrogen chloride reaction, the internal pressure of the system was maintained at 30 mmHg, the temperature of the liquid was maintained at 25-30 ° C, and the azeotropic solution of the outflowed water and EpCH was separated by a decanter, and then the EpCH was measured. Returning to, 125 g of 48 wt% aqueous sodium hydroxide solution was added for 1.5 hours, then aged for 30 minutes, and then 12.5 g of 48 wt% aqueous sodium hydroxide solution was added for 10 minutes, and then aged for 1 hour. .

As a result, 132.0 g of crude TGI was obtained, including 126.0 g of TGI, and the yield of the added ICA was 84.8%.

Claims (7)

The reaction of isocyanuric acid with epichlorohydrin in the presence of methanol and water is carried out using the presence of a catalyst selected from the group consisting of quaternary ammonium hydroxide and quaternary ammonium halide, and the reaction product is dehydrogenated. Method for producing triglycidyl isocyanurate, characterized in that. The method according to claim 1, wherein 6-30 mol of epichlorohydrin, 1-10 mol of methanol, and 0.01-12 mol of water are used for 1 mol of isocyanuric acid. The method according to claim 1, wherein the catalyst solution is added dropwise to a solution of isocyanuric acid, epichlorohydrin and methanol, and methanol and water are distilled off after the dropping is completed. 4. The process according to claim 3, wherein epichlorohydrin is added sequentially to the reaction system to supplement epichlorohydrin accompanied by methanol and water removed by distillation. The method according to claim 3, wherein dehydrochlorination is carried out by sequentially adding an alkali metal compound aqueous solution or a solid alkali metal compound while blowing gas into the reaction solution from which methanol and water are removed under reduced pressure. The method according to claim 1, further comprising the step of depositing epichlorohydrin from the reaction solution after the reaction product is dehydrogenated. The method of claim 6, wherein the solution is maintained at less than 90 ° C. when epichlorohydrin is distilled off.