JP2851517B2 - Method for producing diaryl aromatic dicarboxylic acid ester - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an aromatic dicarboxylic acid diaryl ester sulfonate. More specifically, the present invention relates to a method for producing an aromatic dicarboxylic acid diaryl ester sulfonate which is useful as an intermediate for producing dyes, high molecular polymers, ultraviolet absorbers, pharmaceuticals and the like or as a high molecular polymer modifier.

[0002]

2. Description of the Related Art Such an aromatic dicarboxylic acid diaryl ester sulfonate is described in Japanese Patent Application Laid-Open No. 48-12083 for use in polyamide fibers. It is used as a coalescing modifier. Further, JP-A-1-111
No. 035 discloses the use of a polyester as a modifier for producing a water-absorbing composite yarn. However, in any case, there is no description about the method for producing the aromatic dicarboxylic acid diaryl ester sulfonate in the present invention, and although the present agent exhibits an excellent modifying effect on a high molecular weight polymer, Suggest that there was no suitable manufacturing method. This can be inferred from the following.

In general, the following method can be considered as a method for producing an aromatic dicarboxylic acid aryl ester.
That is, 1) a method of directly esterifying an aromatic dicarboxylic acid and a phenol, 2) a method of reacting an aromatic dicarboxylic acid chloride with a phenol in the presence of a basic compound and a solvent, 3) an aromatic dicarboxylic acid and a diaryl There is a method of heating and melting carbonate in the presence of a catalyst.

[0004] Among the above methods, the method 1) may be capable of producing an aromatic dicarboxylic acid diaryl ester sulfonate with inexpensive raw materials. However, in the reaction using a usual transesterification catalyst, the reaction temperature is low. Since the temperature is usually 280 ° C. or higher, the boiling point of phenols under normal pressure is exceeded, and a reaction vessel that can withstand high pressure is required. Moreover, in the case of the aromatic dicarboxylic acid diaryl ester sulfonate, since the dicarboxylic acid sulfonate as a raw material has lower solubility and reactivity than dicarboxylic acid, it is necessary to further raise the reaction temperature, such as a decomposition reaction. Easily cause side reactions.

In the production of alkyl esters,
A method of reacting a carboxylic acid in the presence of a non-volatile acid such as sulfuric acid in an alcohol is used, but in the reaction between the carboxylic acid and the phenol, the phenol undergoes a nucleophilic reaction. I can't get it.

In the method 2), when a raw material containing a sulfonate is used, it is difficult to produce an acid chloride as a raw material. Even if the acid chloride is obtained, it is disadvantageous in terms of cost since a reaction solvent is used in the subsequent reaction.

The method 3) is a method which can easily produce a diaryl ester, but when producing an aromatic dicarboxylic acid diaryl ester sulfonate,
The production is difficult because of the very low solubility of the corresponding dicarboxylic acids.

As another method, 4) a method of sulfonating an aromatic dicarboxylic acid diester can be considered. However, when producing an aromatic dicarboxylic acid diaryl ester sulfonate, a phenoxy group is more easily sulfonated than an aromatic group having a carboxylic acid group, and a desired product cannot be obtained.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing the above-mentioned aromatic dicarboxylic acid diaryl ester sulfonate, which has not been effectively produced until now.

[0010]

According to the present invention, there is provided an aromatic dicarboxylic acid dialkyl ester sulfonate represented by the following formula (A) in the presence of a transesterification catalyst: A diaryl carbonate represented by the following formula (B) in a ratio of 2 to 3 mol per mol and heat-melting at 250 to 320 ° C, wherein the diaryl aromatic dicarboxylate represented by the following formula (C) is melted. This is a method for producing an ester sulfonate.

[0011]

Embedded image

Wherein R ¹ and R ² are each independently an alkyl group having 1 to 6 carbon atoms, R ³ is a hydrogen atom, and 1 to 6 carbon atoms.
And M ⁺ represents an alkali metal ion. The substituents R ¹ and R ² of the aromatic dicarboxylic acid dialkyl ester sulfonate represented by the formula (A) used in the present invention are alkyl groups having 1 to 6 carbon atoms, and specifically, methyl ester, ethyl It is preferable to form an ester. In the production of these aromatic dicarboxylic acid dialkyl ester sulfonates, a conventionally known production method of heating the corresponding aromatic dicarboxylic acid sulfonate in an alcohol in the presence of a nonvolatile acidic catalyst such as sulfuric acid is used. Available.

M ⁺ is an alkali metal, and is preferably a sodium salt or a potassium salt. Specific examples include dimethyl 5-sodium sulfo-isophthalate,
-Diethyl sodium sulfo-isophthalate, dimethyl 5-potassium sulfo-isophthalate, diethyl 5-potassium sulfo-isophthalate, dimethyl 2-sodium sulfo-terephthalate, diethyl 2-sodium sulfo-terephthalate, 2-potassium sulfo-terephthalate And dimethyl 2,2-potassium sulfo-terephthalate.

The substituent R ³ as the diaryl carbonate represented by the formula (B) is preferably a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, an alkoxy group or an aryl group. Specifically, diphenyl carbonate, bis (2-
Examples thereof include (methylphenyl) carbonate, bis (4-methylphenyl) carbonate, bis (2-methoxyphenyl) carbonate and bis (4-methoxydiphenyl) carbonate. Of these, diphenyl carbonate is particularly preferred.

In the present invention, the diaryl carbonate represented by the above formula (B) is used in a ratio of 2 to 3 mol, preferably 1 mol of the dialkyl aromatic dicarboxylic acid sulfonate represented by the above formula (A), more preferably. , 2
Use from 2.5 to 2.5 moles. If the amount is less than 2 mol, the transesterification reaction is incomplete, the peripheral ratio of the desired product is not sufficient, and purification tends to be difficult. There is no particular problem if the amount is more than 3 mol, but many unreacted substances will remain after the reaction.

The transesterification catalyst used in the present invention is not particularly limited as long as it can be used for ordinary transesterification. Such transesterification catalysts include antimony compounds such as antimony trioxide, stannous acetate, dibutyltin oxide, tin compounds such as dibutyltin diacetate, zinc compounds such as zinc acetate, calcium compounds such as calcium acetate, sodium carbonate, Examples thereof include alkali metal salts such as potassium carbonate.

The amount of the catalyst used is 1 mole of the dialkyl aromatic dicarboxylic acid sulfonate,
A ratio of 0.0003 mol to 0.02 mol is preferable,
0.003 mol to 0.015 mol is more preferred.
Although this amount is larger than the amount used in a normal transesterification reaction, the reaction in the present invention is an exchange reaction between esters, so the reaction rate is slow, and it is necessary to use more catalyst than in a normal transesterification reaction. Is preferred.

In the present invention, the aromatic dicarboxylic acid dialkyl ester sulfonate represented by the formula (A) and the diaryl carbonate represented by the formula (B) are heated and melted in the presence of the transesterification catalyst. It is preferable that the aromatic dicarboxylic acid dialkyl ester sulfonate be dried before the reaction. This is because the sulfonate salt easily absorbs moisture, so that a part of the diaryl carbonate is prevented from being decomposed by the absorbed moisture. It is also preferable to use various additives such as an antioxidant at the time of the reaction.

The temperature at which these compounds are heated and melted is preferably from 250 ° C. to 320 ° C., and preferably from 270 ° C. to 3 ° C.
00 ° C. is more preferred. If the temperature is lower than 250 ° C., the reaction does not proceed, and if the temperature is higher than 320 ° C., side reactions such as decomposition tend to occur. The reaction time depends on the reaction temperature and the amount of catalyst, but is usually about 1 hour to several tens of hours.

A low boiling distillate is formed with the reaction. The distillate is taken out of the reaction system. This is because the reaction does not proceed unless the distillate is taken out of the reaction system because the reaction is an equilibrium reaction. This low-boiling distillate is mainly composed of an alkylaryl carbonate or a dialkyl carbonate, which can be used for producing a diaryl carbonate after recovery.

The reaction can be carried out under elevated pressure to reduced pressure, but is usually carried out under normal pressure to reduced pressure. Preferably, the reaction is carried out under normal pressure, and when the reaction is almost completed, the pressure is reduced to remove unreacted diaryl carbonate.

Although the obtained product can be used as it is, it is more preferable to purify it. As a purification method,
Recrystallization is preferred. Purification by distillation is difficult due to the inclusion of the sulfonate. As the recrystallization solvent, general solvents such as alcohol solvents such as methanol and ethanol and hydrocarbon solvents such as xylene can be used.

[0023]

According to the present invention, an aromatic dicarboxylic acid diaryl ester sulfonate, which has been difficult to produce, although its effectiveness has been known, can be converted into a normal transesterification reaction by using an inexpensive raw material. Since it can be easily manufactured with the device, its industrial significance is extremely large.

[0024]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited only to the examples. In the examples, “parts” means “parts by weight”.

[0025]

Example 1 177.6 parts of dimethyl 5-sodium sulfoisophthalate, 321 parts of diphenyl carbonate and 1.2 parts of dibutyltin diacetate were charged into a reactor having a stirrer and a distilling system, and the inside of the vessel was purged with nitrogen. Thereafter, the mixture was heated to 280 ° C. under normal pressure and reacted for 6 hours. Then 4
The pressure was reduced to 00 mmHg, and unreacted diphenyl carbonate was distilled off. The obtained product was recrystallized from methanol. The melting point of the obtained product is from 303 ° C. to 308 ° C., and the ¹ H-NMR spectrum and the IR spectrum are shown in FIGS. 1 and 2, respectively.

[0026]

Comparative Example 1 The same reaction as in Example 1 was carried out except that 160.8 parts of 5-sodium sulfoisophthalic acid was used instead of 177.6 parts of dimethyl 5-sodium sulfoisophthalate. Even if the above reaction,
5-Sodium sulfoisophthalic acid did not dissolve and no reaction product was obtained.

From the above, it can be seen that the present invention is an effective method for producing an aromatic dicarboxylic acid diaryl ester sulfonate.

[Brief description of the drawings]

FIG. 1 is a ¹ H-NMR spectrum of the product of Example 1.

FIG. 2 is an IR spectrum of the product of Example 1.

Claims (1)

(57) [Claims] In the presence of a transesterification catalyst, an aromatic dicarboxylic acid dialkyl ester sulfonate represented by the following formula (A) and 2 to 3 moles per mole of the aromatic dicarboxylic acid dialkyl ester sulfonate are used. A diaryl carbonate represented by the following formula (B)
A method for producing an aromatic dicarboxylic acid diaryl ester sulfonate represented by the following formula (C), characterized by heating and melting at 50 ° C. to 320 ° C. Embedded image Wherein R ¹ and R ² each independently represent an alkyl group having 1 to 6 carbon atoms, R ³ represents a hydrogen atom, an alkyl group or an aryl group having 1 to 6 carbon atoms, and M ⁺ represents an alkali metal ion. ]