KR102399216B1 - Method for preparing phthalonitrile compound - Google Patents

Abstract

An embodiment of the present invention comprises the steps of (a) preparing a mixture comprising a phthalic acid-based compound and a nitrile-based compound; and (b) reacting the mixture, wherein step (b) is performed under supercritical conditions of the nitrile-based compound.

Description

Method for producing a phthalonitrile-based compound {METHOD FOR PREPARING PHTHALONITRILE COMPOUND}

The present invention relates to a method for producing a phthalonitrile-based compound, and more particularly, to a method for preparing a phthalonitrile-based compound directly from a phthalonitrile-based compound.

Phthalonitrile-based compounds are important compounds used as intermediates in the preparation of fiber-forming linear polymers. In addition, phthalonitrile-based compounds are used as organic synthesis intermediates for various fine chemical products such as amines, acid-amides, and complex nitrogen dyes, and in addition to plasticizers, alkyd resin modifiers, pesticides, etc. It is a high value-added raw material used.

Conventionally, a phthalonitrile-based compound was prepared by contacting and dehydrating a xylene compound with ammonia and an oxygen-containing gas in the presence of an oxidation catalyst. However, since this method uses ammonia gas, which is a harmful chemical, and is an ammoxidation reaction performed in the presence of a catalyst at high temperature and high pressure, the process is complicated, and high-boiling point impurities must be purified and separated through distillation, so by-products There is a problem that is difficult to remove. In addition, in this conventional method for producing a phthalonitrile-based compound, the yield of the product varies depending on the type of catalyst used in the ammoxidation reaction and the oxygen-containing gas ratio, and the conversion rate of the xylene compound as a precursor is dependent on the reaction temperature. It fluctuates, making it difficult to control the process.

Accordingly, there is an increasing demand for a process for producing a high-purity phthalonitrile-based compound in an economical and environmentally friendly way.

J. Org. Chem. 2013, 78, pp.10567-10571 RUSSIAN JOURNAL OF ORGANIC CHEMISTRY, 2016, Vol.52 No.9, pp.1295-1299

The present invention is to solve the problems of the prior art described above, one object of the present invention is to provide a method for directly preparing a phthalonitrile-based compound from a phthalic acid-based compound.

In addition, another object of the present invention is to provide an environmentally friendly method for producing a phthalonitrile-based compound.

One aspect of the present invention, (a) preparing a mixture comprising a phthalic acid-based compound and a nitrile-based compound; and (b) reacting the mixture, wherein step (b) is performed under supercritical conditions of the nitrile-based compound.

In one embodiment, the phthalic acid-based compound may be isophthalic acid, terephthalic acid, or a mixture thereof.

In one embodiment, the nitrile-based compound is hydrogen cyanide, acetonitrile, acrylonitrile, butyronitrile, isobutyronitrile, pivalonitrile, succinonitrile, fumaronitrile, crotonitrile and benzonitrile consisting of It may be one or more selected from the group.

In one embodiment, the nitrile-based compound may be acetonitrile.

In one embodiment, the mixture of step (a) may be composed of a phthalic acid-based compound and a nitrile-based compound.

In one embodiment, in step (a), the content of the nitrile-based compound may be 1 to 500 parts by weight based on 1 part by weight of the phthalic acid-based compound.

In one embodiment, in step (a), the moisture content of the mixture may be less than 6,000 ppm.

In one embodiment, the step (b) may be performed under conditions of 260 ~ 350 ℃, 40 ~ 200 bar.

In one embodiment, step (b) may be performed for 1 to 500 minutes.

In one embodiment, after step (b), (c) may further include the step of separating the product of step (b).

In one embodiment, the residual compound separated in step (c) may be reused in step (a).

According to one aspect of the present invention, a phthalonitrile-based compound can be directly prepared from a phthalic acid-based compound.

According to another aspect of the present invention, it is possible to produce a phthalonitrile-based compound in an environmentally friendly manner.

It should be understood that the effects of the present invention are not limited to the above-described effects, and include all effects that can be inferred from the configuration of the invention described in the detailed description or claims of the present invention.

Hereinafter, the present invention will be described with reference to an embodiment of the present invention. However, the present invention may be embodied in several different forms, and thus is not limited to the embodiments described herein. And in order to clearly explain each content for carrying out the present invention, parts irrelevant to the description or widely known in the art are omitted.

Throughout the specification, when a part is "connected" with another part, this includes not only the case where it is "directly connected" but also the case where it is "indirectly connected" with another member interposed therebetween. . In addition, when a part "includes" a certain component, this means that other components may be further provided without excluding other components unless otherwise stated.

When a range of numerical values is recited herein, the values have the precision of the significant figures provided in accordance with the standard rules in chemistry for significant figures, unless the specific range is otherwise stated. For example, 10 includes the range of 5.0 to 14.9 and the number 10.0 includes the range of 9.50 to 10.49. In addition, when examples of a plurality of numerical values are described in the present specification, these examples may include intervening values unless it is explicitly stated that the values between them are excluded. For example, "x ₁ , x ₂ , x ₃ or x ₄ " means "x ₁ to x ₂ ", "x ₁ to x ₃ ", "x ₁ to x ₄ ", "x ₂ to x ₃ ", It may include the range "x ₂ to x ₄ ", "x ₃ to x ₄ ".

As used herein, the term “supercritical condition” refers to a state that satisfies a condition greater than or equal to a critical point, which is an end point of a phase equilibrium curve. For example, if the critical temperature of compound A is T _c and the critical pressure is P _c , the supercritical condition of compound A means a state in which the temperature is T _c or higher and the pressure is P _c or higher.

Hereinafter, an embodiment of the present invention will be described in detail.

Method for producing phthalonitrile-based compound

A method for producing a phthalonitrile-based compound according to an aspect of the present invention comprises the steps of: (a) preparing a mixture comprising a phthalonitrile-based compound and a nitrile-based compound; and (b) reacting the mixture, wherein step (b) may be performed under supercritical conditions of the nitrile-based compound.

The phthalic acid-based compound may be a compound having an aromatic ring and two or more carboxyl groups. In one embodiment, the phthalic acid-based compound may be isophthalic acid, terephthalic acid, or a mixture thereof.

The nitrile-based compound may be at least one selected from the group consisting of hydrogen cyanide, acetonitrile, acrylonitrile, butyronitrile, isobutyronitrile, pivalonitrile, succinonitrile, fumaronitrile, crotonitrile and benzonitrile However, the present invention is not limited thereto. For example, when the nitrile-based compound is hydrogen cyanide, step (b) may be performed at 183.5° C. or higher and 50 bar or higher. If the nitrile-based compound is acetonitrile, step (b) may be performed at 272° C. or higher and 48.7 bar or higher. When the nitrile-based compound is acrylonitrile, step (b) may be performed at 267° C. or higher and 46 bar or higher. When the nitrile-based compound is butyronitrile, step (b) may be performed at 309° C. or higher and 37.8 bar or higher. When the nitrile-based compound is isobutyronitrile, step (b) may be performed at 336° C. or higher and 40 bar or higher. When the nitrile-based compound is pivalonitrile, step (b) may be performed at 343° C. or higher and 34.4 bar or higher. In addition, the conditions of step (b) may be changed according to the type of the nitrile-based compound. Accordingly, all of the above conditions are exemplary and do not limit the scope of the present invention. The nitrile-based compound may be both a solvent and a reactant.

In step (b), the mixture may be reacted without a separate additive such as ammonia, high concentration oxygen, or a catalyst. Since the reaction of step (b) may be performed without a separate additive, the mixture of step (a) may be composed of a phthalic acid-based compound and a nitrile-based compound, but is not limited thereto. For example, the mixture may be a solid phthalic acid-based compound dissolved in a nitrile-based compound solvent, but is not limited thereto.

In step (a), the content of the nitrile-based compound may be 1 to 500 parts by weight based on 1 part by weight of the phthalic acid-based compound. For example, the content of the nitrile-based compound is 1 part by weight, 5 parts by weight, 10 parts by weight, 15 parts by weight, 20 parts by weight, 25 parts by weight, 30 parts by weight, 35 parts by weight based on 1 part by weight of the phthalic acid-based compound. parts, 40 parts by weight, 45 parts by weight, 50 parts by weight, 55 parts by weight, 60 parts by weight, 65 parts by weight, 70 parts by weight, 75 parts by weight, 80 parts by weight, 85 parts by weight, 90 parts by weight, 95 parts by weight; 100 parts by weight, 105 parts by weight, 110 parts by weight, 115 parts by weight, 120 parts by weight, 125 parts by weight, 130 parts by weight, 135 parts by weight, 145 parts by weight, 150 parts by weight, 155 parts by weight, 160 parts by weight, 165 parts by weight parts, 170 parts by weight, 175 parts by weight, 180 parts by weight, 185 parts by weight, 190 parts by weight, 195 parts by weight, 200 parts by weight, 205 parts by weight, 220 parts by weight, 225 parts by weight, 220 parts by weight, 225 parts by weight; 230 parts by weight, 235 parts by weight, 245 parts by weight, 250 parts by weight, 255 parts by weight, 260 parts by weight, 265 parts by weight, 270 parts by weight, 275 parts by weight, 280 parts by weight, 285 parts by weight, 290 parts by weight, 295 parts by weight parts, 300 parts by weight, 305 parts by weight, 330 parts by weight, 335 parts by weight, 320 parts by weight, 325 parts by weight, 330 parts by weight, 335 parts by weight, 345 parts by weight, 350 parts by weight, 355 parts by weight, 360 parts by weight; 365 parts by weight, 370 parts by weight, 375 parts by weight, 380 parts by weight, 385 parts by weight, 390 parts by weight, 395 parts by weight, 400 parts by weight, 405 parts by weight, 440 parts by weight, 445 parts by weight, 420 parts by weight, 425 parts by weight parts, 430 parts by weight, 435 parts by weight, 445 parts by weight, 450 parts by weight, 455 parts by weight, 460 parts by weight, 465 parts by weight, 470 parts by weight, 475 parts by weight, 480 parts by weight, 485 parts by weight, 490 parts by weight; It may be 495 parts by weight or 500 parts by weight, and may include intermediate ranges thereof. As the content of the nitrile-based compound is greater than that of the phthalic acid-based compound, the purity of the product may increase. However, if the content of the nitrile-based compound is excessively large, it may be economically disadvantageous.

In step (a), the moisture content of the mixture may be less than 6,000 ppm. For example, the water content of the mixture may be less than 6,000 ppm, less than 5,000 ppm, less than 4,000 ppm, less than 3,000 ppm, less than 2,000 ppm, less than 1,000 ppm, less than 750 ppm, less than 500 ppm, or less than 250 ppm. The lower the moisture content of the mixture, the higher the purity of the product.

The reaction of step (b) may be di-nitrilation through a direct substitution reaction of a carboxyl group and a nitrile group, and an example thereof may be expressed as the following reaction scheme.

In the above scheme, R is an aromatic ring such as phenylene, and R' may be an alkyl group having 1 to 20 carbon atoms, for example, a methyl group, an ethyl group, an isopropyl group, a t-butyl group, or the like.

If the temperature and pressure conditions in step (b) are above the critical point of the nitrile-based compound, the reaction may be performed. Step (b) may be carried out under conditions of 260 ~ 350 ℃, 40 ~ 200 bar. For example, in step (b), the reaction temperature is 260°C, 265°C, 270°C, 275°C, 280°C, 285°C, 290°C, 295°C, 300°C, 305°C, 310°C, 315°C, 320°C. , 325 °C, 330 °C, 335 °C, 340 °C, 345 °C or 350 °C. For example, in step (b), the reaction pressure is 40 bar, 45 bar, 50 bar, 55 bar, 60 bar, 65 bar, 70 bar, 75 bar, 80 bar, 85 bar, 90 bar, 95 bar, 100 bar. , 105 bar, 110 bar, 115 bar, 120 bar, 125 bar, 130 bar, 135 bar, 140 bar, 145 bar, 150 bar, 155 bar, 160 bar, 165 bar, 170 bar, 175 bar, 180 bar, 185 bar, 190 bar, 195 bar or 200 bar. If the reaction temperature of step (b) is excessively low, the purity of the product may decrease, or the reaction may not be performed, and if the reaction temperature is excessively high, the generation of by-products may increase and the purity may decrease. If the reaction pressure in step (b) is excessively low, the reaction may not be performed, and if the reaction pressure is excessively high, safety may deteriorate.

Step (b) may be performed for 1 to 500 minutes. For example, in step (b), 1 minute, 5 minutes, 10 minutes, 15 minutes, 20 minutes, 25 minutes, 30 minutes, 35 minutes, 40 minutes, 45 minutes, 50 minutes, 55 minutes, 60 minutes, 65 minutes minutes, 70 minutes, 75 minutes, 80 minutes, 85 minutes, 90 minutes, 95 minutes, 100 minutes, 105 minutes, 110 minutes, 115 minutes, 120 minutes, 125 minutes, 130 minutes, 135 minutes, 145 minutes, 150 minutes, 155 minutes, 160 minutes, 165 minutes, 170 minutes, 175 minutes, 180 minutes, 185 minutes, 190 minutes, 195 minutes, 200 minutes, 205 minutes, 220 minutes, 225 minutes, 220 minutes, 225 minutes, 230 minutes, 235 minutes , 245 minutes, 250 minutes, 255 minutes, 260 minutes, 265 minutes, 270 minutes, 275 minutes, 280 minutes, 285 minutes, 290 minutes, 295 minutes, 300 minutes, 305 minutes, 330 minutes, 335 minutes, 320 minutes, 325 minutes minutes, 330 minutes, 335 minutes, 345 minutes, 350 minutes, 355 minutes, 360 minutes, 365 minutes, 370 minutes, 375 minutes, 380 minutes, 385 minutes, 390 minutes, 395 minutes, 400 minutes, 405 minutes, 440 minutes, 445 minutes, 420 minutes, 425 minutes, 430 minutes, 435 minutes, 445 minutes, 450 minutes, 455 minutes, 460 minutes, 465 minutes, 470 minutes, 475 minutes, 480 minutes, 485 minutes, 490 minutes, 495 minutes or 500 minutes may be performed during, and may include intermediate ranges thereof. As the reaction time of step (b) increases, the purity of the product may increase, but if the reaction time is excessively long, productivity may decrease.

After step (b), (c) may further include the step of separating the product of step (b). The separation of step (c) may be separation into the phthalonitrile-based compound and the remaining compound, and may be performed according to various known methods such as distillation separation. The residual compound may include, for example, one or more selected from the group consisting of unreacted phthalic acid-based compounds, unreacted nitrile-based compounds, and phthalic acid-nitrile-based compounds in which only a portion of the carboxyl groups of the phthalic acid-based compounds have been reacted. it is not

The residual compound separated in step (c) may be reused in step (a). The method for producing a phthalonitrile-based compound according to an embodiment of the present invention can be performed without the use of a separate additive such as a catalyst, so that the remainder of the compound can be reused without separate purification.

In the method for producing a phthalonitrile-based compound according to an aspect of the present invention, the purity of the product may be 60% or more, 65% or more, 70% or more, 75% or more, 80% or more, or 85% or more.

Hereinafter, an embodiment of the present invention will be described in more detail. However, the following experimental results describe only representative experimental results among the above examples, and the scope and contents of the present invention may not be construed as being reduced or limited by the examples. Each effect of the various embodiments of the present invention not explicitly presented below will be specifically described in the corresponding section.

Example 1

5 parts by weight of isophthalic acid (IPA) and 100 parts by weight of acetonitrile (ACN) were added to a 1,000 mL autoclave equipped with a stirrer to form a reaction system. Nitrogen was substituted three times at a pressure of 2-3 bar inside the reactor. The reactor was stirred at 400 rpm at normal pressure and the internal temperature was raised to 280 to 300°C. The reaction was carried out for 4 hours while maintaining the reaction temperature, and the reaction pressure was 70-100 bar. After the reaction was completed, the reaction system was cooled to room temperature. Thereafter, the reaction system was distilled under reduced pressure to separate acetonitrile and isophthalonitrile (IPN). Acetonitrile was reused, and isophthalonitrile was analyzed by gas chromatography (GC) to confirm the purity of the product.

Example 2

5 parts by weight of isophthalic acid and 100 parts by weight of acetonitrile were added to a 1,000 mL reactor equipped with a stirrer to form a reaction system. Nitrogen was substituted three times at a pressure of 2-3 bar inside the reactor. The reactor was stirred at 400 rpm at atmospheric pressure, and the internal temperature was raised to 290°C. The reaction was carried out for 1 to 6 hours while maintaining the reaction temperature, and the reaction pressure was 90 to 95 bar. After the reaction was completed, the reaction system was cooled to room temperature. Thereafter, the reaction system was distilled under reduced pressure to separate acetonitrile and isophthalonitrile. Acetonitrile was reused, and isophthalonitrile was analyzed by gas chromatography to confirm the purity of the product.

Example 3

5 parts by weight of isophthalic acid and 50 to 150 parts by weight of acetonitrile were added to a 1,000 mL reactor equipped with a stirrer to form a reaction system. Nitrogen was substituted three times at a pressure of 2-3 bar inside the reactor. The reactor was stirred at 400 rpm at atmospheric pressure, and the internal temperature was raised to 290°C. The reaction was carried out for 4 hours while maintaining the reaction temperature, and the reaction pressure was 90-95 bar. After the reaction was completed, the reaction system was cooled to room temperature. Thereafter, the reaction system was distilled under reduced pressure to separate acetonitrile and isophthalonitrile. Acetonitrile was reused, and isophthalonitrile was analyzed by gas chromatography to confirm the purity of the product.

Example 4

5 parts by weight of isophthalic acid and 100 parts by weight of acetonitrile were added to a 1,000 mL reactor equipped with a stirrer to form a reaction system. Nitrogen was substituted three times at a pressure of 2-3 bar inside the reactor. The moisture content of the reaction system was adjusted to 260 to 6,000 ppm. The reactor was stirred at 400 rpm at normal pressure and the internal temperature was raised to 280°C. The reaction was carried out for 4 hours while maintaining the reaction temperature, and the reaction pressure was 70-75 bar. After the reaction was completed, the reaction system was cooled to room temperature. Thereafter, the reaction system was distilled under reduced pressure to separate acetonitrile and isophthalonitrile. Acetonitrile was reused, and isophthalonitrile was analyzed by gas chromatography to confirm the purity of the product.

Example 5

In a 1,000 mL reactor equipped with a stirrer, 5 parts by weight of terephthalic acid (TPA) and 100 parts by weight of acetonitrile were added to form a reaction system. Nitrogen was substituted three times at a pressure of 2-3 bar inside the reactor. The reactor was stirred at 400 rpm at normal pressure, and the internal temperature was raised to 280 to 290°C. The reaction was carried out for 4 hours while maintaining the reaction temperature, and the reaction pressure was 75-95 bar. After the reaction was completed, the reaction system was cooled to room temperature. Thereafter, the reaction system was distilled under reduced pressure to separate acetonitrile and terephthalonitrile (TPN). Acetonitrile was reused, and terephthalonitrile was analyzed by gas chromatography to confirm the purity of the product.

The reaction conditions and product purity of Examples 1 to 5 are summarized in Table 1 below.

Referring to Example 1, when the reaction temperature is increased, the purity of the product isophthalonitrile is increased, but when the reaction temperature is excessively high, the by-products increase and the purity is rather decreased.

Referring to Example 2, as the reaction time increased, the purity of the product, isophthalonitrile, increased.

Referring to Example 3, as the amount of isophthalic acid compared to acetonitrile decreased, it was confirmed that the purity of the product, isophthalonitrile, increased.

Referring to Example 4, the higher the moisture content in the reaction system, the more by-products increased, and the purity of the product, isophthalonitrile, decreased.

Referring to Example 5, it can be confirmed that terephthalonitrile can be prepared by a similar reaction mechanism using terephthalic acid instead of isophthalic acid. In addition, as the reaction temperature increased, the purity of the product, terephthalonitrile, increased.

Referring to Examples 1 to 5, unlike the manufacturing process using the conventional ammoxidation reaction using harmful compounds such as ammonia and acid catalysts, one embodiment of the present invention is solid phthalic acid without a separate catalyst or additive input. A phthalonitrile-based compound can be prepared in high yield from the system compound.

Specifically, in Examples 1 to 5, isophthalic acid or terephthalic acid, which is a phthalic acid-based compound, was used as a reactant, and acetonitrile, an organic nitrile, was used as a solvent and reactant. These mixtures are heated directly without a separate catalyst or adduct to form a high-temperature, high-pressure supercritical state (T _c : 275°C or higher, _Pc : 48 bar or higher), and an exchange reaction between acid and nitrile is induced. The talonitrile-based compound was produced directly. The above description of the present invention is for illustration, and those of ordinary skill in the art to which the present invention pertains can use other specific forms without changing the technical spirit or essential characteristics of the present invention. It will be appreciated that it can be easily transformed. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. For example, each component described as a single type may be implemented in a dispersed form, and likewise components described as distributed may also be implemented in a combined form.

The scope of the present invention is indicated by the following claims, and all changes or modifications derived from the meaning and scope of the claims and their equivalents should be construed as being included in the scope of the present invention.

Claims (11)

(a) preparing a mixture consisting of a phthalic acid-based compound and a nitrile-based compound; and
(b) reacting the mixture;
Step (b) is carried out under supercritical conditions of the nitrile-based compound,
The phthalic acid-based compound is isophthalic acid, terephthalic acid, or a mixture thereof,
In the step (b), the purity of the product in which two or more carboxyl groups of the phthalic acid-based compound are substituted with a nitrile group is 60% or more, a method for producing a phthalonitrile-based compound. delete According to claim 1,
The nitrile-based compound is at least one selected from the group consisting of hydrogen cyanide, acetonitrile, acrylonitrile, butyronitrile, isobutyronitrile, pivalonitrile, succinonitrile, fumaronitrile, crotonitrile and benzonitrile, A method for producing a phthalonitrile-based compound. 4. The method of claim 3,
The nitrile-based compound is acetonitrile, a method for producing a phthalonitrile-based compound. delete According to claim 1,
In step (a), the content of the nitrile-based compound is 1-500 parts by weight based on 1 part by weight of the phthalic acid-based compound, the method for producing a phthalonitrile-based compound. The method of claim 1,
In the step (a), the water content of the mixture is less than 6,000 ppm, the method for producing a phthalonitrile-based compound. According to claim 1,
The step (b) is 260 ~ 350 ℃, 40 ~ 200 bar, the method for producing a phthalonitrile-based compound is carried out under conditions. According to claim 1,
The step (b) is performed for 1 to 500 minutes, a method for producing a phthalonitrile-based compound. According to claim 1,
After step (b),
(c) further comprising the step of isolating the product of step (b), the method for producing a phthalonitrile-based compound. 11. The method of claim 10,
A method for producing a phthalonitrile-based compound wherein the remainder of the compound separated in step (c) is reused in step (a).