KR101745680B1 - Preparation method for para-phenylene diamine - Google Patents

Abstract

The present invention relates to a process for preparing para-phenylenediamine comprising reacting para-diiodobenzene with ammonia in the presence of a heterogeneous catalyst on which a metal is supported on a support, P-phenylenediamine of high purity can be obtained in a high yield in a short period of time and the efficiency and economical efficiency of the process can be improved.

Description

PREPARATION METHOD FOR PARA-PHENYLENE DIAMINE [0002]

The present invention relates to a process for producing phenylenediamine, and more particularly, to a process for producing phenylene diamine which can obtain high purity para-phenylenediamine in a short time and can easily separate by-products, Diamine. ≪ / RTI >

Phenylenediamine is used in various fields such as dyes, pigments, oxidative stabilizers, fuel additives and raw materials for polyurethane, and is widely used as a main raw material of aramid which is a linear polymer having excellent flame retardancy and strength.

As a general method for preparing such phenylenediamine, especially para-phenylenediamine, nitroaniline is obtained by adding benzene and nitrobenzene to the synthesized nitrobenzene chloride to obtain nitroaniline, The method is known. It is also known to produce para-phenylenediamine through an azo compound. Specifically, 1,3-diphenyl triazene can be synthesized by reacting diazo benzene formed by reacting aniline and nitrogen oxide with aniline. The 1,3- Diphenyltriazene can be converted to 4-aminoazo benzene via rearrangement and para-phenylenediamine can be obtained by reducing this 4-aminoazo benzene with hydrogen.

However, such perylene diamine production processes must undergo various reaction steps, and a large amount of by-products are generated in the reaction process, so that the reaction yield is not high, and the reduction reaction is required to be performed using an expensive hydrogen catalyst.

To solve this problem, a method of reacting a halogenated benzene compound with a nitrogen compound under a copper catalyst has been proposed. For example, a method has been proposed in which phenylenediamine is produced by reacting dichlorobenzene and a water-soluble ammonia solution at a temperature of about 200 ° C and a high pressure of about 1000 psig for 5 to 10 hours using a copper catalyst. Also, a method of synthesizing para-phenylenediamine salt by synthesizing para-phenylene bis-acetamide with para-iodide benzene and acetamide as a raw material and hydrolyzing it was proposed .

However, these methods have problems such as long-term reaction under high-temperature and high-pressure reaction conditions, alkylation of halogen ions produced in the course of the reaction, or strong acids such as hydrochloric acid during the hydrolysis. In addition, the amount of byproducts produced by these methods was not sufficiently reduced, so that the reaction yield could not be sufficiently improved, and the reaction time was too long to increase the production efficiency of the product.

Accordingly, there is a demand for development of an efficient and economical method of synthesizing phenylenediamine which can obtain a final product of high purity within a short reaction time in a single reaction step without applying high temperature and high pressure reaction conditions.

The present invention relates to a process for producing para-phenylenediamine of high purity in a short time, in particular, a process for producing para-phenylenediamine of high purity within a short period of time, Diamine in an organic solvent.

The present invention provides a process for preparing para-phenylenediamine comprising reacting para-diiodide benzene with ammonia in the presence of a heterogeneous catalyst on which a metal is supported on a support.

Hereinafter, a method for preparing para-phenylenediamine according to a specific embodiment of the present invention will be described in detail.

According to one embodiment of the invention, there is provided a process for preparing para-phenylenediamine comprising reacting para-diiodobenzene with ammonia in the presence of a heterogeneous catalyst supported on a carrier have.

The present inventors have found that when para-diiodide benzene and ammonia are reacted with a heterogeneous catalyst on which a metal is supported on a carrier, even when a very low reaction temperature and normal pressure are applied, para-phenylenediamine And it was confirmed through experiments that the invention was completed.

Particularly, since the amount of by-products generated in the production method of para-phenylenediamine is small, ammonia can be easily separated into gas, and the remaining by-products can be separated by a single step by distillation under reduced pressure. By-products can be easily separated without the need to apply steps or by-product treatment steps. In addition, the method of producing para-phenylenediamine does not require expensive equipment for applying high-temperature and high-pressure reaction conditions, and it is possible to synthesize para-phenylenediamine of high purity within a short reaction time. In addition, in the production method of para-phenylenediamine, there is little loss of catalyst, and it is not necessary to use a ligand or a base for improving the activity of the catalyst, so that the production cost can be reduced, Etc. can be minimized and an environmentally friendly manufacturing process can be constituted.

As the carrier used in the heterogeneous catalyst, zeolite, silica, alumina, charcoal, ceramics, or a mixture thereof is preferably used. As the metal used for the heterogeneous catalyst, copper (Cu), palladium (Pd), platinum (Pt), nickel (Ni), iron (Fe), cobalt (Co) or a mixture thereof may be used.

The para-diiodobenzene may react in a molten state and may be applied in a molten state using an organic solvent. The ammonia may include ammonia water, ammonium salt or ammonia gas.

In the step of reacting the para-diiodobenzene with ammonia, the molar ratio of the amine group: ammonia substituted in benzene is 1: 2 to 1: 1000, preferably 1: 4 to 1: 400, more preferably 1: 8 to 1: 100. The 'benzene-substituted amine group' means an amine group included in the amine monosubstituted benzene compound or amine disubstituted benzene compound produced in the step of reacting para-diiodobybenzene with ammonia. Accordingly, the number of moles of the 'benzene-substituted amine group' may be the sum of the number of moles of the compound represented by the formula (1) and the number of moles of the compound represented by the formula (2).

[Chemical Formula 1]

(2)

When the concentration of ammonia around the para-diiodobenzene is high and the concentration of the amine-substituted benzene compound, that is, the concentration of aniline iodide or phenylenediamine, is low in the step of reacting para-diiodo benzene with ammonia, The occurrence can be minimized. Accordingly, when the molar ratio of the amine group: ammonia substituted in benzene is less than 1: 2, the yield of the overall reaction may be lowered. When the molar ratio is more than 1: 1000, Additional costs may be incurred to remove and recover it.

The step of reacting the para-diiodobenzene with ammonia may be carried out in the presence of a base such as benzene, toluene, alkylbenzene, benzene chloride, aniline, chlorinated naphthalene, nitrobenzene, methanol, ethanol, dimethylsulfoxide (DMSO), dimethylformamide In a solvent such as methylpyrrolidone (NMP), methylene chloride, tetrahydrofuran (THF), dioxane, dimethoxyethane, ethylene glycol or mixtures thereof.

Meanwhile, the step of reacting the para-diiodobenzene with ammonia may further include adding a base. The base may serve to neutralize iodic acid which may be formed during the reaction of para-diiodobenzene and ammonia. The base may be used without any limitations as long as it is known to be able to neutralize the halogen acid. However, the base may be an inorganic base such as sodium hydroxide, potassium hydroxide, sodium hydrogencarbonate, sodium carbonate, potassium carbonate or cesium carbonate or a primary or secondary amine And the like are preferably used alone or in combination.

Meanwhile, when para-diiodide benzene and ammonia are reacted by applying a metal-supported heterogeneous catalyst on the support, the reaction temperature may be 180 to 350 ° C, preferably 200 to 250 ° C. When para-diiodide benzene and ammonia are reacted with the metal catalyst fixed on the specific carrier, a high reaction yield can be obtained as described later even when the reaction temperature is not so high. Particularly, when the reaction temperature is lower than 180 ° C., the amount of para-phenylenediamine produced may be insignificant. When the reaction temperature is higher than 350 ° C., unnecessary side reactions may occur.

Also, the step of reacting the para-diiodobenzene with ammonia can be carried out under atmospheric pressure or normal pressure. In the case of reacting para-diiodobenzene and ammonia using the metal catalyst fixed on the specific carrier, phenylenediamine can be obtained in a high yield in a short time without applying high-pressure conditions.

Meanwhile, the step of reacting the para-diiodobenzene with ammonia may be performed in a fixed-bed reactor packed with a fixed metal catalyst. If the fixed bed reactor is used, the reactor design is simplified, the catalyst is not lost, and it is economical and there is no need to separate the catalyst, so that the purification process can be simplified.

The fixed bed reactor can be used without any limitations as long as it can be commonly used for the synthesis of organic compounds, and the size, shape and kind of the reactor can be appropriately controlled in consideration of reaction conditions, amounts of reactants and amounts of products. In addition, the amount of the catalyst and the amount of the reactant to be charged in the fixed bed reactor may be appropriately controlled depending on the size, shape, and the like of the reactor.

For example, a fixed bed reactor having an inside diameter (ID) of 1/2 inch and a length of 50 cm can be filled with a metal catalyst fixed to the carrier at a height of 20 to 40 cm, and 2 to 100 g of para -Diiodobenzene and 20 to 1000 g of ammonia gas may be added to the reaction system.

According to the present invention, it is possible to provide a method for producing phenylenediamine, which can obtain high purity para-phenylenediamine in a short time and can easily separate by-products, thereby improving process efficiency and economical efficiency .

Figure 1 shows a schematic view of a fixed bed reactor that can be used for the preparation of para-phenylenediamines.

The invention will be described in more detail in the following examples. However, the following examples are illustrative of the present invention, and the present invention is not limited by the following examples.

< Example : Para- Phenylene Diamine  Manufacturing>

Example 1

30 cm of 10% palladium (10% Pd on alumina) fixed to alumina was charged into a tubular reaction tube having a 1/2 inch inner diameter and a length of 50 cm, and then the temperature was raised to 200 ° C by injecting argon gas . Ammonia gas was fed into the reactor at 200 g / hr and para-diiodide benzene at 20 g / hr to obtain para-phenylenediamine.

Example 2

Para-phenylenediamine was obtained in the same manner as in Example 1, except that the reaction temperature was changed to 250 占 폚.

Example 3

Para-phenylenediamine was obtained in the same manner as in Example 1, except that ammonia gas was introduced into the reactor at a rate of 100 g / hr and para-diiodide benzene was introduced at a rate of 10 g / hr.

Example 4

Para-phenylenediamine was obtained in the same manner as in Example 1, except that 500 g / hr of ammonia gas and 50 g / hr of para-diiodo benzene were added to the reactor.

Example 5

Para-phenylenediamine was obtained in the same manner as in Example 1 except that 10% Pd on charcoal fixed to charcoal was used as a catalyst.

Example 6

Para-phenylenediamine was obtained in the same manner as in Example 1, except that 5% palladium on zeolite (5% Pd on Zeolite) was used as a catalyst.

Example 7

Para-phenylenediamine was obtained in the same manner as in Example 1 except that 10% copper (10% Cu on Alumina) fixed on alumina was used as a catalyst.

Example 8

Para-phenylenediamine was obtained in the same manner as in Example 1, except that a 1: 1 mixture of para-diiodobenzene and para-iodide aniline was used instead of para-diiodobenzene.

Reference Example 1

The reaction was carried out in the same manner as in Example 1 except that only an alumina carrier was used in place of the 10% palladium (10% Pd on alumina) catalyst fixed on the alumina.

Reference Example 2

Para-phenylenediamine was obtained in the same manner as in Example 1, except that the reaction temperature was changed to 150 占 폚.

In Examples 1-8 and 1-2, the material from the bottom of the reactor was analyzed by gas chromatography using a DB-5 column. These results are shown in Table 1 below. The reaction yield and byproduct content were measured using Agilent HP7980 and quantified using the standard method.

PPD PIA p-DIB Other content(%) content (%) content (%) content (%) Example 1 19.5 34.1 46.4 - Example 2 24.8 36.7 34.2 4.3 Example 3 22.5 48.3 26.5 2.7 Example 4 11.2 25.1 63.7 - Example 5 18.4 37.8 43.8 Example 6 17.9 25.4 56.7 Example 7 8.5 29.1 62.4 Example 8 34.2 44.3 24.5 Reference Example 1 0 0 100 Reference Example 2 0 1.1 98.9

* PPD: para-phenylenediamine, PIA: para-iodoaniline, p-DIB: para-diiodobenzene

As shown in Table 1, in Examples 1 to 8 in which para-diiodide benzene and ammonia were reacted in the presence of a heterogeneous catalyst on which a metal was supported on the support, a reaction temperature and an atmospheric pressure were not so high The para-phenylenediamine can be obtained in a short time, and the production of the para-phenylenediamine is performed in a single reactor, so that not only the loss of the catalyst is little, but also the by-products are easily removed.

On the other hand, as shown in Reference Example 1, when the para-diiodide benzene and ammonia react with each other in a fixed-bed reactor packed with only a carrier free of a metal catalyst, it is confirmed that para-phenylenediamine is not typically produced .

Also, when para-diiodide benzene and ammonia are reacted at 150 DEG C in the presence of a heterogeneous catalyst on which a metal is supported, PIA: a small amount of aniline p-iodide is produced, and para-phenylenediamine It was confirmed that the prototype was not generated.

Claims (9)

In the presence of a heterogeneous catalyst on which a metal is supported on a carrier,
Reacting para-diiodo benzene with ammonia,
The carrier includes at least one selected from the group consisting of zeolite, silica, alumina, charcoal and ceramic,
The metal catalyst includes at least one selected from the group consisting of palladium (Pd), platinum (Pt), nickel (Ni), and cobalt (Co)
Wherein the step of reacting the para-diiodobenzene with ammonia is carried out at 180 to 300 ° C.
delete delete The method according to claim 1,
Wherein the molar ratio of amine group: ammonia substituted in benzene is 1: 2 to 1: 1000 in the step of reacting para-diiodo benzene with ammonia.
The method according to claim 1,
Wherein the ammonia comprises ammonia water, an ammonium salt or an ammonia gas.
The method according to claim 1,
The step of reacting the para-diiodobenzene with ammonia comprises:
(DMSO), dimethylformamide (DMF), N-methylpyrrolidone (NMP), methylene chloride, tetrachloride, tetrachloroethane, Wherein the solvent is in at least one solvent selected from the group consisting of hydrofluoric acid, hydrofluoric acid, hydrofluoric acid, hydrofluoric acid, hydrofluoric acid, hydrofluoric acid, hydrofluoric acid, hydrofluoric acid, hydrofluoric acid,
delete The method according to claim 1,
Wherein the step of reacting para-diiodobenzene with ammonia is carried out at atmospheric pressure.
The method according to claim 1,
Wherein the step of reacting the para-diiodobenzene with ammonia is carried out in a fixed-bed reactor packed with a metal catalyst on which the carrier is immobilized.

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