JPH0314310B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for producing a polyamine by carrying out a catalytic reduction reaction of cyanoethylated N-(2-aminoethyl)piperazine. Generally, a polyamine corresponding to the cyanoethylated amine is produced by subjecting a cyanoethylated amine, which is an amine compound having a primary or/and secondary amino group to which acrylonitrile is added, to a catalytic reduction reaction in the presence of a hydrogenation catalyst. The method is widely known. Furthermore, in order to further improve the yield of polyamines corresponding to the cyanoethylated amines, a method is already known in which reaction system hair ammonia is added to carry out a catalytic reduction reaction. Based on these known methods, the present inventors
N-(2-aminoethyl)piperazine (hereinafter referred to as N
-Abbreviated as AEP. ), we investigated a method for producing polyamines from the cyanoethylated product, and found that in a reaction system without the addition of ammonia, a large amount of propylamine was produced as a by-product. In other words, a large amount of polyamine with a lower molecular weight and heavy amine with a molecular weight of 350 or more are produced as by-products,
It was found that the desired polyamine yield was not fully satisfactory. Not only is there an economic loss due to a decrease in the yield of polyamine, but an increase in the amount of by-products of low-boiling amines, mainly propylamine (boiling point 48°C), is caused by the removal of low-boiling amines from the reaction solution, the operations associated with recovery, and This increases the load on the equipment and causes disadvantages in the process. Furthermore, when the catalyst is separated and recovered from the reaction liquid obtained by carrying out the above reaction method, a phenomenon of decrease in transient properties due to deterioration of the catalyst is observed, which increases the burden of catalyst separation operation. In addition, attempts were made to reduce the cost of using the catalyst by repeatedly using the recovered catalyst, but the catalyst was poisoned and almost deactivated after being used for one reaction. resulting in increased economic losses. In the reaction method of adding ammonia, liquid ammonia (boiling point -33°C) is usually added, which adds complexity to the equipment involved in handling, recovering, and abatement of ammonia. Further, addition of a small amount of ammonia does not have a small effect on improving the target polyamine yield, and it is necessary to add a large amount of ammonia to obtain a sufficiently satisfactory yield. In this case, since the ammonia gas partial pressure at a given reaction temperature becomes extremely large, taking into consideration the hydrogen gas partial pressure required for the reaction, the reaction must be carried out under relatively high pressure, and equipment with high pressure resistance is required. Moreover, the burden of increasing the amount of ammonia gas processed after the reaction becomes large, and the production process is not necessarily advantageous from an industrial perspective. As mentioned above, when cyanoethylated N-AEP is catalytically reduced by a conventional method, a large amount of low-boiling point amines, which are undesirable from the reaction point of view, are produced as by-products, which not only leads to a decrease in the desired polyamine yield, but also leads to a decrease in catalyst efficiency. It also causes poisoning. Further, in a method in which it is possible to improve the yield by using ammonia, the addition of a large amount of ammonia gas inevitably causes negative effects in terms of operation and equipment. An improved method for hydrogenating cyanoethylated products, which produces useful polyamines in high yields under relatively low reaction pressures, allows the use of general-purpose equipment, and facilitates reaction and post-treatment of reaction liquids. is strongly desired. In view of these circumstances, the present inventors have conducted intensive research and found that by adding an aliphatic amine having a primary amino group to cyanoethylated N-AEP and performing a catalytic reduction reaction, propylamine by-product was produced. The present inventors have discovered new facts such as the fact that polyamines corresponding to the cyanoethylated product can be produced in high yields while significantly suppressing the amount of polyamines and under relatively low reaction pressures, leading to the completion of the present invention. That is, the present invention provides N-(2-aminoethyl)
A cyanoethylated compound of piperazine with acrylonitrile added to it, represented by the chemical structural formula below, was prepared in a hydrogen gas atmosphere and in the presence of a hydrogenation catalyst.

[Formula] (Y= -CH ₂ -CH ₂ CN or -H) Provides a method for producing a polyamine, characterized in that an aliphatic amine having a primary amino group is added during the catalytic reduction reaction. It is. The raw material used in the present invention is a cyanoethylated product represented by the chemical structural formula below, which is obtained by adding acrylonitrile to N-(2-aminoethyl)piperazine (N-AEP).

[Formula] (Y= -CH ₂ CH ₂ CN or -H) In other words, N-(2-aminoethyl)-N'- which is obtained by adding an equimolar amount of acrylonitrile to N-AEP
(2-cyanoethyl)piperazine or N-
[N″-(2-cyanoethyl)aminoethyl] monocyanoethylated piperazine, N-[N″- with double mole of acrylonitrile added to N-AEP
(2-cyanoethyl)aminoethyl]-N'-(2-
Cyanoethyl)piperazine or dicyanoethylated N-[N″-bis(2-cyanoethyl)aminoethyl]piperazine, N-[N″-{bis(2-cyanoethyl) prepared by adding 3 times the mole of acrylonitrile to N-AEP )}aminoethyl]-N′-(2
-cyanoethyl)piperazine tricyanoethylated product, etc. are exemplified as raw materials. The monocyanoethylated product, dicyanoethylated product, or tricyanoethylated product shown above may be used as a raw material alone, or depending on the use of the polyamine product, the monocyanoethylated product, the dicyanoethylated product, or the tricyanoethylated product may be used as a raw material. , tricyanoethylated products, and the like may be mixed and used in any desired composition. As the hydrogenation catalyst used in the present invention, metal catalysts widely used in general catalytic reduction reactions can be used, including nickel, copper, platinum, ruthenium,
Palladium, rhodium, iridium, etc. are useful. These metals can also be used in the form of supported metal catalysts supported on carriers such as diatomaceous earth, alumina, activated clay, and activated carbon. Among them, nickel-based catalysts are most suitable as catalysts for the reaction of the present invention in terms of catalyst activity and economy. As the nickel-based catalyst, used are Raney nickel, stabilized nickel supported on diatomaceous earth, and nickel supported on diatomaceous earth whose main component is nickel to which other metals such as copper, chromium, iron, and zinc are added. As exemplified above, products whose main component is nickel as a metal component and to which a different metal other than nickel is added; Metals supported on various carriers together with nickel can be used as catalysts, and the types of different metals to be added are not particularly limited. The amount of the catalyst to be used is not particularly limited, and is selected in consideration of the productivity related to the reaction rate, the influence on the polyamine yield, etc., and is not particularly limited. Generally, it is added in an amount of 1 to 20% by weight based on the cyanoethylated raw material. If the amount of catalyst added is less than 1% by weight, the reaction rate becomes slow, which is not preferable in terms of productivity. If the amount added is 20% by weight or more, it will not have a favorable effect on the reaction rate or the desired polyamine yield, and will simply increase the burden of separation operations due to an increase in the amount of catalyst, and will not be particularly advantageous. The catalyst used in the reaction method of the present invention still maintains high activity even after being used in the reaction, so it is usually separated and recovered from the reaction solution by filtration or decantation, and is repeated from the second time onwards. It can be used in reactions such as this, greatly contributing to reducing the cost of catalyst use, and bringing great economic benefits. The aliphatic amine having a primary amino group used in the present invention is R-NH ₂ (R is 1 to 1 carbon atoms).
8 alkyl group), _NH2 -R'(-NH-R'')- _nNH2 (n=0,1,
2; R′ and R″ are diamines or polyalkylene polyamines represented by alkylene groups having 2 to 6 carbon atoms; polyalkylene polyamines also include compounds containing a cyclic piperazine ring in the molecule. To give specific examples of representative compounds, examples of alkylamines include methylamine, ethylamine,
Examples include propylamine, butylamine, cyclohexylamine, 2-ethylhexylamine, and the like. Examples of diamines include ethylenediamine, propanediamine, butanediamine, hexamethylenediamine, and cyclohexyldiamine. Examples of polyalkylene polyamines include diethylenetriamine, N-(2-aminoethyl)piperazine, triethylenetetramine, dipropylenetriamine, tripropylenetetramine, N-
(3-aminopropyl)ethylenediamine and the like. Alkylamines have the effect of suppressing the elimination reaction of cyanoethyl groups or aminopropyl groups from raw materials or products, as well as suppressing catalyst poisoning, but when low-boiling point amines such as methylamine or ethylamine are used, , it is preferable to use a primary alkylamine having a boiling point of 60° C. or higher, since this involves a slight increase in the operational burden of recovery from the reaction solution. Furthermore, propylamine and molecular weight
Ethylenediamine is an additive amine with excellent practicality that suppresses the formation of undesirable by-products such as heavy amines of 400 or more, and can produce the desired useful polyamine in high yield under relatively low reaction pressure. Propanediamine, diethylenetriamine,
Examples include diamines or polyalkylene polyamines such as dipropylene triamine, N-(2-aminoethyl)piperazine, and N-aminoethylpropanediamine. These relatively low molecular weight diamines or polyalkylene polyamines not only significantly suppress poisoning of the catalyst and provide a reaction solution consisting of high quality polyamine with extremely little coloring, but also
It is most preferably used because it is extremely easy to separate and recover aliphatic amines from the reaction solution by distillation and has excellent industrial operability. The reaction is carried out by adding usually 1 to 50% by weight of the raw material of these aliphatic amines to the cyanoethylated product. If the amount added is less than 1% by weight, the effect of suppressing the amount of by-products of low-boiling amines will be small, and the catalyst activity will be lowered due to poisoning. Adding more than 50% by weight does not provide any further excellent effects in terms of reaction, and only increases the burden of recovering the large excess of fatty amine added to the reaction system from the reaction solution, which is not particularly advantageous. . If it is an aliphatic amine having a primary amino group, it will bring many excellent effects in terms of reaction and operation, and there are no particular limitations on the type of aliphatic amine to be added or the amount added. It is preferable to select the type and amount of the aliphatic amine as appropriate depending on the intended use of the produced polyaminone since it has some influence on the quality and molecular weight distribution of the aliphatic amine. For example, when alkylene diamine is added and the reaction is carried out, in addition to the polyamine corresponding to the cyanoethylated product,
A polyamine having one more amino group in the molecule is produced. Polyalkylene polyamines with relatively high molecular weight, such as tetraethylene pentamine and pentaethylene hexamine, which are generally produced industrially, are a mixture of polyamines with different chemical structures, and are extremely useful amine materials in many industrial fields. It is often used as. Taking these practical aspects into consideration, the reaction method of the present invention provides an extremely industrially superior method for producing polyamines that can flexibly produce polyamine mixtures with various functionalities by selecting and adding the type of aliphatic amine. It has advantages that can be provided. The reaction of the present invention is carried out under hydrogen gas pressure,
Although the pressure range is not particularly limited, it can usually be carried out under a pressure of 1 to 300 kg/cm ² .
More preferably, it is carried out under a pressure of 5 to 50 kg/cm ² . Generally, in the hydrogenation reaction of nitrile groups,
It is known that hydrogen pressure has a large effect on the desired amine yield, and a relatively high hydrogen pressure of 70 Kg/cm ² or more is often applied. However, when an aliphatic amine having a primary amino group is added to the reaction system as in the present invention, the desired polyamine can be obtained in high yield even when the reaction is carried out under relatively low hydrogen pressure of 5 to 50 kg/ ^cm2 . It was found that it could be manufactured at a high rate. That is, the addition of the aliphatic amine enables the reaction under low hydrogen pressure, which is extremely advantageous in terms of equipment such as reactors and compressors. The decrease in hydrogen pressure can be compensated for by extending the reaction time, but considering productivity from a practical standpoint, hydrogen pressure of 5
Usually carried out at Kg/cm ² or more. The upper limit of the hydrogen pressure is also not particularly limited. Since the selection of hydrogen pressure has an important influence on the reaction rate, it is preferable to set it appropriately taking into consideration the heat removal accompanying the exothermic reaction. Reaction temperature also has an important effect on reaction rate and polyamine yield. The reaction of the present invention is usually carried out at 80 to 190°C.
Preferably it is carried out at 100-170°C. Below 80°C, the reaction rate is slow and impractical. At temperatures above 190°C, the polyamine produced will decompose, and the amount of by-products of low-boiling amines will rapidly increase, and the amount of heavy amines with a molecular weight of 350 or more will increase, leading to a decrease in the desired polyamine yield. During the hydrogenation reaction, an inactive organic solvent or diluent may be added to the nitrile or amine to carry out the reaction, but this is not particularly advantageous as it reduces the efficiency of reactor usage due to an increase in the amount of reaction liquid. . The method of supplying raw materials to the reactor is not particularly limited. After first charging the raw material cyanoethylated product, catalyst and primary amine into the reactor, hydrogen gas may be introduced and the reaction may be carried out at a predetermined temperature, or the catalyst, primary amine and necessary It is also possible to carry out the reaction by adding a reaction-inert solvent depending on the reaction conditions and supplying the raw material cyanoethylated product with a metering pump at a predetermined temperature and under a predetermined hydrogen pressure. The reaction method of the present invention is usually carried out using a so-called suspended catalyst system in which the reaction is carried out under a hydrogen gas atmosphere using a pressurized reactor while stirring, but even if it is carried out in a fixed bed reaction method, the reaction is first class. The addition of the amino group-containing aliphatic amine has a similar favorable effect on the reaction, and the reaction method is not particularly limited. After the catalyst is separated and removed from the reaction solution obtained by the method of the present invention, a small amount of by-produced low-boiling amines and the added aliphatic amine are removed by distillation. Depending on the use of the produced polyamine, it may be commercialized as a polyamine mixture as it is, or
In addition, tetramine corresponding to the hydrogenation product of the monocyanoethylated product, pentamine corresponding to the hydrogenation product of the dicyanoethylated product, hexamine corresponding to the hydrogenation product of the tricyanoethylated product, and furthermore, by a side reaction, The resulting heptamine and other fractions may be rectified into products. Even when the former is commercialized as a polyamine mixture, the reaction liquid obtained by the method of the present invention is a very clean product liquid with a slight yellow color, so its commercial value can be said to be high. As mentioned above, N-(2-aminoethyl)
3 in a molecule such as a cyanoethylated form of piperazine.
By applying the reaction method of the present invention to a method for producing a polyalkylene polyamine having a relatively large molecular weight by hydrogenating a cyanoethylated raw material having 2 amino groups, it is possible to eliminate the severe catalyst poisoning and heavy deterioration seen in known techniques. It has now been possible to significantly improve the drawbacks such as a significant increase in the amount of modified amines and propylamine by-products. In addition, the reaction method of the present invention opens the way to cost reduction by reusing the catalyst, and also makes it possible to improve the yield of the desired useful polyamine.
Furthermore, we have achieved milder reaction conditions such as hydrogen pressure, and achieved the establishment of an industrial process that is extremely advantageous in terms of equipment and operation. The present invention will be further explained below with reference to Examples.
The present invention is not particularly limited thereby. Examples 1 to 3 150 g of cyanoethylated N-(2-aminoethyl)piperazine (N-AEP) shown in Table 1 was placed in a 300 ml stainless steel electromagnetic stirring autoclave.
and ethylenediamine 30g, Raney nickel 7.5g
(dry base) was charged, and the gas phase was replaced with hydrogen gas. The reaction was carried out by heating to a predetermined reaction temperature and pressurizing hydrogen gas at a reaction pressure of 30 kg/cm ² . The hydrogenation reaction was carried out at the reaction temperature shown in Table 1 depending on the type of cyanated product of N-AEP as a raw material. After the absorption of hydrogen gas stopped, the reaction was continued for an additional 20 minutes at the same temperature. After the reaction solution was cooled, the catalyst was removed, and the resulting slightly yellow colored solution was quantitatively analyzed by gas chromatography.
In addition, heavy amines with a molecular weight of 400 or more were quantitatively analyzed using high performance liquid chromatography. The results are shown in Table 1.

[Table] Example 4 Into the same reactor as in Example 1, 150 g of dicyanoethylated N-AEP, 20 g of 1,3-propanediamine, and 6 g of Raney nickel (dry base) were charged, and the gas phase was replaced with hydrogen gas. Then, further pressure was applied. The reaction temperature was controlled within the range of 135 to 140°C, and the hydrogenation reaction was carried out at a reaction pressure of 25 kg/cm ² . Hydrogen absorption was completed within 1 hour after the start of the reaction, so 140
It was continued for an additional 20 minutes at °C. After cooling the reaction solution, the catalyst was separated, and the yellow colored reaction solution was quantitatively analyzed using a gas chromatograph. Quantitative analysis of heavy amines was performed using high performance liquid chromatography. The Raney nickel separated and recovered from the above reaction solution was used in the reaction repeatedly three times under the same reaction conditions. Table 2 shows the reaction results of the first and third reactions.

[Table] Example 5 In the same reactor as in Example 1, 50 g of dioxane, 7.5 g of Raney nickel (dry base) and 7.5 g of ethylenediamine were charged, the gas phase was replaced with hydrogen gas, and the pressure was further increased. Reaction temperature 135℃, reaction pressure 35
Under conditions of Kg/cm ² , 150 g of dicyanoethylated N-AEP as a raw material was supplied using a metering pump over 2 hours. After the supply, the reaction was further carried out under the same conditions for 1 hour, then cooled and the catalyst was separated. The composition of the slightly yellow colored reaction solution was analyzed using the same analytical method as in Example 1. As a result, propylamine
1.0g, triamine 0.3g, tetramine 9.4g, pentamine 122.1g, hexamine 11.2g, heavy amine
10.0g was obtained. Example 6 In the same reactor as in Example 1, 150 g of dicyanoethylated N-AEP, 15 g of ethylenediamine, and 6 g of 65% nickel supported on diatomaceous earth (reduction stable nickel) were charged, and the gas phase was replaced with hydrogen gas. Further pressure was applied. The hydrogenation reaction was carried out at a reaction temperature of 135°C and a reaction pressure of 31 kg/cm ² . Hydrogen absorption was completed 1.3 hours after the start of the reaction, and continued for an additional 10 minutes under the same conditions.
After cooling the reaction solution, the catalyst was separated. The composition of the slightly yellow colored reaction solution was analyzed using the same analytical method as in Example 1. As a result, propylamine 0.8
g, triamine 0g, tetramine 7.9g, pentamine 119.3g, hexamine 16.3g, heavy amine 10.6
g was obtained. Examples 7 and 8 In the same reactor as in Example 1, 150 g of dicyanoethylated N-AEP was added, and a sulfur-resistant nickel catalyst (Ni45-47%, Cr2-3%, Cu3-4%, diatomaceous earth 27-29 %, graphite 4-5%, Ni form Ni+NiO)
7.5 g, in Example 7 15 g of diethylenetriamine,
In Example 8, 15 g of N-(2-aminoethyl)piperazine was charged in each case, and the gas phase was replaced with hydrogen gas and further pressurized. Reaction temperature 140℃, reaction pressure 28Kg/cm ²
A hydrogenation reaction was carried out. After hydrogen absorption was completed 1.2 hours after the start of the reaction, the same conditions were maintained for an additional 15 minutes. After cooling the reaction solution, the catalyst was separated, and the composition of the slightly yellow colored solution was analyzed using the same analysis method as in Example 1. As a result, in Example 7, 0.7 g of propylamine, 8.5 g of tetramine, 121.3 g of pentamine
g, hexamine 0.2 g, heptamine 6.8 g, and heavy amine 17.2 g were obtained. In addition, in Example 8, 0.7 g of propylamine, 8.3 g of tetramine, and pentamine
119.8 g, hexamine 0.3 g, heptamine 7.2 g, and heavy amino 18.2 g were obtained. Example 9 In the same reactor as in Example 1, 150 g of dicyanoethylated N-AEP, 15 g of monoethylamine, and 6 g of Raney nickel were charged, the gas phase was replaced with hydrogen gas, and hydrogen was further pressurized. The hydrogenation reaction was carried out at a reaction temperature of 135° C. and a reaction pressure of 35 Kg/cm ² . After starting the reaction
Hydrogen absorption was completed in 1.4 hours, and further 10 hours under the same conditions.
Lasted for minutes. After cooling the reaction solution, separate the catalyst,
The composition of the obtained reaction solution was analyzed using the same analytical method as in Example 1. As a result, propylamine 1.2
g, triamine 0g, tetramine 14.8g, pentamine 123.3g, hexamine 0.4g, weight amine 12.0
g was obtained. Comparative Example 1 In the same reactor as in Example 1, 150 g of dicyanoethylated N-AEP and 7.5 g of Raney nickel (dry base) were charged, the gas phase was replaced with hydrogen gas, and the hydrogen gas was further pressurized. Reaction temperature 140℃, reaction pressure 30
The hydrogenation reaction was carried out at Kg/cm ² . Hydrogen absorption was completed 7 hours after the start of the reaction. Then further at the same temperature for 30
The reaction lasted for minutes. The reaction solution was cooled, the catalyst was separated, and the brown colored reaction solution was quantitatively analyzed using the same analysis method as in Example 1. As a result, propylamine 17.9g, triamine 3.1g, tetramine 22.7
g, pentamine 84.3 g, and heavy amine 21.0 g were obtained. The catalyst separated and recovered in the above reaction was repeatedly used in a second reaction under the same reaction conditions, but no hydrogen absorption was observed. Comparative Example 2 In the same reactor as in Example 1, 150 g of dicyanoethylated N-AEP and 7.5 g of Raney nickel (dry base) were charged, and the gas phase was replaced with hydrogen gas.
15.0 g of liquid ammonia was collected into a sample introduction tube, pressurized with hydrogen gas, and introduced into the reactor. reaction temperature
The hydrogenation reaction was carried out at 140°C and a reaction pressure of 35 kg/cm ² .
Hydrogen gas absorption was completed 3 hours and 40 minutes after the start of the reaction. Thereafter, the reaction was continued for an additional 30 minutes at the same temperature.
The reaction solution was cooled, the internal pressure was released, and ammonia was purged. The product was quantified using the same analytical method as in Example 1 for the yellowish brown colored reaction solution. As a result, 6.4 g of propylamine, 1.0 g of triamine, 22.0 g of tetramine, 107.3 g of pentamine, 1.5 g of hexamine, and 16.3 g of heavy amine were obtained. Comparative Example 3 In the same reactor as in Example 1, 150 g of dicyanoethylated N-AEP and 7.5 g of Raney nickel (dry base) were charged, and the gas phase was replaced with hydrogen gas.
5.0 g of liquid ammonia was collected in a sample introduction tube, pressurized with hydrogen gas, and introduced into the reactor. reaction temperature
When the hydrogenation reaction was carried out at 140°C and a reaction pressure of 35 kg/cm ² , the reaction stopped when 60% of the theoretical amount of hydrogen was absorbed.

Claims (1)

[Claims] A cyanoethylated product represented by the chemical structural formula below, which is obtained by adding acrylonitrile to 1 N-(2-aminoethyl)piperazine, is treated with hydrogen gas [Formula] (Y= -CH ₂ CH ₂ CN or - H) A method for producing a polyamine, which comprises adding an aliphatic amine having a primary amino group during the catalytic reduction reaction in an atmosphere and in the presence of a hydrogenation catalyst. 2. The manufacturing method according to claim 1, wherein the hydrogenation catalyst is Raney nickel or diatomaceous earth supported nickel.