JPS595592B2 - Method for producing poly(hydroxyalkyl)isocyanurate - Google Patents

Description

Detailed Description of the Invention The present invention relates to poly(hydroxyalkyl) used as a raw material for polyester resins with excellent heat resistance and chemical resistance.
This invention relates to a new method for producing isocyanurate.

Conventionally, when producing tris(2-hydroxyethyl) isocyanurate among poly(hydroxyalkyl) isocyanurates, for example, ethylene oxide is added to cyanuric acid and the resulting mixture is heated and reacted, or cyanuric acid and methyl iodide are produced. A method has been developed in which trimethyl isocyanurate is synthesized by reacting with trimethyl isocyanurate, and then reacted with ethylene glycol.

However, in the case of the former method, since ethylene oxide is a gas at room temperature and is easily explosive, the manufacturing process is dangerous, and special manufacturing equipment is required to prevent leakage to the outside, making it difficult to invest in equipment. It costs a huge amount of money. In the case of the latter method, after converting isocyanuric acid to trimethyl isocyanurate,
Furthermore, the production cost was high due to the two-stage method in which ethylene glycol was reacted. The present invention has focused on this point, and as a result of intensive research into a method for producing poly(hydroxyalkyl) isocyanurate by a safe and simple method that does not require special production equipment, it has been found that carbon alkylene is always added to isocyanuric acid. It has been discovered that by carrying out a heating reaction under pressure, a decarboxylation reaction occurs and poly(hydroxyalkyl)isocyanurate can be obtained very easily.

In the present invention, as the alkylene carbonate, for example, ethylene carbonate and propylene carbonate are used, and these may be used alone or in combination.

In addition, in the present invention, regarding the blending ratio of cyanuric acid and alkylene carbonate, 2 moles or more of alkylene carbonate is used per 1 mole of cyanuric acid, but it is usually good to use up to about 5 moles of alkylene carbonate, and more than that is suitable. In this case, the reaction rate becomes faster, but unreacted alkylene carbonate also increases, which is economically disadvantageous unless recovery is taken into account. As a typical example of the method of the present invention, the chemical formula for producing tris(2-hydroxyethyl)isocyanurate by heating and reacting 1 mole of cyanuric acid with 3 moles of ethylene carbonate as alkylene carbonate is as follows: It is. In the present invention, when cyanuric acid and alkylene carbonate are heated, it is possible to produce poly(hydroxyalkyl)isocyanurate without using a particular reaction solvent. The reaction proceeds uniformly by using a solvent that is inert to cyanuric acid and alkylene carbonate, such as pyrrolidone, and reacting the cyanuric acid dispersed and dissolved in the solvent with alkylene carbonate. .

In this case, even a solvent active against alkylene carbonate such as ethylene glycol can be used as long as it has a lower activity than cyanuric acid. It is also possible to carry out the reaction by using alkylene carbonate in an amount greater than the reaction equivalent and using the excess amount as a solvent. Further, in order to smoothly proceed with the reaction of the present invention, potassium carbonate, sodium carbonate, sodium hydroxide, etc. may be used as a catalyst.

Next, examples of the present invention will be described.

Example 1 Cyanuric acid 129t1 Ethylene carbonate 264t1 Dimethylformamide 4007 as a solvent and 0.4r of potassium carbonate as a catalyst were put into a flask equipped with a stirrer and a condenser, and the reaction temperature was gradually raised while stirring for 1 hour. When the reaction was continued at this temperature, the reaction occurred while releasing carbon dioxide gas, and the dispersed cyanuric acid was completely dissolved.
It became a clear solution.

After further continuing the reaction at the same temperature for 3 hours, the solution was poured into toluene to precipitate the reaction product, and this was
After filtration, drying at 120°C gives white powder 244
I got r. Note that the reaction yield was 94%. The melting point of this powder was measured to be 136°C, and the measurement results of the infrared absorption spectrum showed that the absorption was the same as that of tris(2-hydroxyethyl)isocyanurate.
It was confirmed that it was 2-hydroxyethyl) isocyanurate.

Further, as a result of measuring the hydroxyl group content, it was 19.4% compared to the calculated value of 19.5%, so the purity was estimated to be 99% or more. Example 2 After putting 10f7 of cyanuric acid and 50y of ethylene carbonate into a test tube, it was heated with occasional shaking, and 3
The reaction temperature was allowed to reach 170° C. over time, and the reaction was carried out at this temperature for 3 hours to obtain a transparent solution.

Next, the solution was poured into toluene to precipitate the reaction product 6y. After applying the resulting precipitate to a salt plate, 1
Tris (2-hydroxy Almost the same absorption as that of ethyl isocyanurate was obtained. Therefore, it was confirmed that this product was a mixture of tris(2-hydroxyethyl)isocyanurate and bis(2-hydroxyethyl)isocyanurate. Further, as a result of measuring the hydroxyl group content and acid value, the hydroxyl group content was 19.4% and the acid value was 4.3, respectively.

The calculated values for tris(2-hydroxyethyl) isocyanurate are hydroxyl group content 19.5% and acid value 0, and the calculated values for bis(2-hydroxyethyl) isocyanurate are hydroxyl group content 15.7% and acid value 258. About 98% of tris(2-hydroxyethyl) isocyanurate and bis(
2-hydroxyethyl) isocyanurate is estimated to be about 2%, and therefore the reaction yield for cyanuric acid is 93% for tris(2-hydroxyethyl)isocyanurate and 1% for bis(2-hydroxyethyl)isocyanurate. Ta. Since these two substances are similar substances, they cannot be separated industrially, but since they have a hydroxyl group with a valence of two or more, they can be fully used as a raw material for polyester resin. As is clear from the above Examples, poly(hydroxyalkyl)isocyanurate can be obtained safely and extremely easily according to the method of the present invention, and its practical value is extremely large.

Claims (1)

[Claims] 1. A method for producing poly(hydroxyalkyl)isocyanurate, which comprises subjecting cyanuric acid to a heating reaction with alkylene carbonate.