JPH0788353B2 - Method for producing aziridine compound - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention is generally obtained by subjecting an alkanolamine represented by the general formula (I) to a gas phase intramolecular dehydration reaction in the presence of a catalyst according to the following formula. The present invention relates to a production method including a step of collecting the aziridine compound represented by the formula (II) from a reaction product containing the aziridine compound.

(R is hydrogen, a methyl group or an ethyl group, X is OH or NH ₂ , Y is NH ₂ when X is OH, and O when X is NH ₂ .
The aziridine compound is a cyclic compound having a three-membered ring with large strain, has both ring-opening reactivity and reactivity as an amine, and is useful as various intermediate raw materials. Above all, ethyleneimine is used as a raw material for agricultural chemicals, pharmaceuticals, etc.
In addition, it has already been widely used in industry as a raw material for amine-based polymers that are fiber treatment agents.

[Prior Art] As a typical method for producing an aziridine compound, a method of producing ethyleneimine by treating a sulfuric acid ester of monoethanolamine with a concentrated alkaline solution in a liquid phase is generally well known, It has already been industrialized. However, this method has a large number of drawbacks industrially because it uses a large amount of sulfuric acid and an alkali as an auxiliary material, so that the productivity is low and an inorganic salt having a low utility value is by-produced.

In recent years, in order to solve the drawbacks of the aziridine production by the liquid phase method, a method for directly producing an aziridine compound by a gas phase intramolecular dehydration reaction of an alkanolamine in the presence of a catalyst without using any auxiliary materials has been reported. There is
No. 50-10593, U.S. Pat.No. 4,301,036, No. 4,2
89,656, 4,337,175 and 4,477,591, European Patent Publication 227,461, 228,8
98, and 230,776). However, all of these are mainly related to the catalyst for the gas phase intramolecular dehydration reaction, and no studies have been made on the industrial production process for obtaining the aziridine compound from the reaction product gas.

Further, in the production of an aziridine compound from an alkanolamine by a gas phase method, a general formula corresponding to a raw material alkanolamine is contained in a reaction product gas. (R is the same as that in the formula (I) of the raw material) By-products such as carbonyl compounds and various amines are included. Raw material alkanolamine is monoethanolamine, monoisopropanolamine, 2-amino-1
-If it is butanol, it corresponds to each (III)
The carbonyl compound of the formula is acetaldehyde, acetone,
It is methyl ethyl ketone. For example, U.S. Pat.
No. 175 and No. 4,477,591 disclose that acetaldehyde is a main by-product in the production of ethyleneimine from monoethanolamine, and that monoethylamine and pyrazines are by-produced, and European Published Patent No. 227,461. No. 228,898, No. 230,77
The publication 6 also describes that the main by-products are carbonyl compounds of the formula (III) and various amines.

[Problems to be Solved by the Invention] Generally, in industrial production of organic compounds by a gas phase method, a method of collecting a target product from a gas phase reaction product and purifying it to obtain a product is performed. However, the industrialization of the aziridine compound production from alkanolamine by the gas phase method has the following problems. That is, first (I
The aziridine compound of the formula (I) generally has a low boiling point, an extremely high vapor pressure, and is itself extremely reactive and has the property of easily undergoing polymerization and other reactions. Next, as described above, a carbonyl compound and various amines are by-produced by the gas phase method. Of these by-products, the carbonyl compound is particularly likely to react with the target aziridine compound to form an adduct, which causes a decrease in the yield of the aziridine compound. In the production of the aziridine compound by the gas phase method, consideration of these problems is essential.

An object of the present invention is to provide a method for efficiently collecting an aziridine compound from a gas phase reaction product in facilitating the subsequent purification of the aziridine compound in manufacturing the aziridine compound from an alkanolamine by a gas phase method. It is in.

[Means for Solving the Problems] The present inventors have conducted extensive studies to achieve this object, and as a result, found that it is extremely effective to carry out the collection step in the presence of an amine compound, and the present invention Is completed. That is, in the present invention, the alkanenoramine of the above formula (I) is subjected to a gas phase intramolecular dehydration reaction in the presence of a catalyst to produce the aziridine compound of the above formula (II), and then the aziridine compound of the above formula (II) is collected in the presence of the amine compound. The method for collecting an aziridine compound represented by the formula (II) is characterized in that: Hereinafter, the present invention will be described in detail.

The method for producing the aziridine compound of the formula (II) by subjecting the alkanolamine of the formula (I) to a gas phase intramolecular dehydration reaction in the presence of a catalyst is shown in the above-mentioned publications, etc. Can be used,
For example, it is performed as follows. First, alkanolamine is passed through the catalyst layer. In some cases, it may be diluted with an inert gas such as nitrogen to an appropriate concentration, or ammonia may be added for the purpose of suppressing side reactions.
Water vapor, hydrogen, etc. may be added to the raw material gas, or all the inert gas may be replaced with ammonia. The operating pressure may be normal pressure, reduced pressure or increased pressure. Reaction temperature is normal
The temperature is in the range of 300 to 500 ° C, and the space velocity of the raw material gas varies depending on the type, concentration, catalyst, etc. of the raw material gas, but is generally 50 to
The range of 5000hr ^-1 is taken. As the catalyst, the catalysts described in the above publications and the like can be used, and in particular, European Published Patent No. 22
The silicon-based and phosphorus-based catalysts disclosed in 7,461, 228,898 and 230,776 can be preferably used.

The feature of the present invention resides in that the aziridine compound is collected in the presence of the amine compound from the reaction product obtained by the above reaction. The amine compound suppresses the polymerization of the aziridine compound and makes it stably exist. Further, as described above, the by-product carbonyl compound is present in the reaction product, and there is a problem that this reacts with the aziridine compound to produce an adduct, but due to the presence of the amine compound, the by-product carbonyl compound is Before reacting with the aziridine compound, it reacts with the amine compound first to form a stable adduct. As a result, the yield of the aziridine compound can be prevented from decreasing, the quality of the aziridine compound can be prevented from decreasing due to the incorporation of the carbonyl compound, and the stability of the aziridine compound can be prevented from decreasing. Furthermore, since the amine compound dissolves the aziridine compound of the formula (II) well, it is possible to collect the aziridine compound having a high vapor pressure with an efficiency of almost 100%.

As the amine compound used in the present invention, various amine compounds can be used. Particularly, the primary amine compound is effective because it reacts immediately with the by-product carbonyl compound in the reaction product to form a stable Schiff base. is there. Further, the secondary amine compound is also effective because it reacts with the carbonyl compound to form a stable adduct. Specific examples of the amine compound include a primary alkanolamine having 2 to 6 carbon atoms such as monoethanolamine and monoisopropanolamine, and a primary aliphatic amine having 2 to 8 carbon atoms such as butylamine and ethylenediamine. Examples thereof include primary aromatic amines having 8 or less carbon atoms such as aniline and secondary alkanolamines having 8 or less carbon atoms such as diethanolamine and diisopropanolamine. It is preferable to use an alkanolamine as a reaction raw material as the amine compound. This is because the unreacted raw material and the unreacted raw material can then be recovered and reused, and the process becomes relatively simple. When using other amine compounds, recovery and reuse of unreacted raw materials and amine compounds must be carried out independently, which complicates the process, and there is a concern that amine compounds will be added as an impurity item in the product. is there.

The amount of the amine compound present when the aziridine compound is collected from the reaction product varies depending on various factors such as the composition of the reaction product, the kind of the amine compound, the temperature, and the structure of the collector, but the unit time Therefore, it is preferably 0.1 mol or more with respect to the number of moles of the aziridine compound in the reaction product and equal to or more moles with respect to the number of moles of the carbonyl compound.
If the amount is too small, the stability of the aziridine compound is poor, or the carbonyl compound is not sufficiently converted to an adduct and the yield of the aziridine compound decreases.

The method of collecting the aziridine compound of the formula (II) from the gas phase intramolecular dehydration reaction product of the present invention in the presence of an amine compound is conducted by introducing the reaction product gas which has undergone the reaction step into an absorption tower and In the method of collecting an aziridine compound in the reaction product gas by dissolving the aziridine compound in the reaction product gas by supplying an absorption liquid consisting of an amine compound or a solution thereof from above the reaction product gas supply position and contacting the reaction product gas. is there. When water is used as the absorption liquid, polymerization of the aziridine compound occurs, and when absorption is performed using a caustic soda aqueous solution as the absorption liquid to prevent polymerization, the by-product carbonyl compound is aziridine compound. It reacts to form an adduct and causes a decrease in yield. You may use the aqueous solution of an amine compound as an absorption liquid. In the case of an amine compound having a relatively high viscosity, the efficiency of contact with the reaction product can be improved by using an amine compound which is dissolved in water and has a reduced viscosity as an absorbing liquid. Further, in the case of an amine compound having a relatively low boiling point, the volatilization of the amine compound can be suppressed by using it by dissolving it in water. However, if the absorption liquid contains a large amount of water, the adduct of the carbonyl compound and the amine compound causes a reverse reaction, and the carbonyl compound cannot be removed smoothly. Therefore, when the amine compound is supplied as an aqueous solution, the concentration of the amine compound in the absorption liquid to be supplied is preferably 30 mol% or more, and more preferably 80 mol% or more, though it depends on the water content in the reaction product. The absorption temperature is appropriately in the range of 0 to 80 ° C., though it depends on the kind of absorption liquid. The operating pressure may be normal pressure, reduced pressure or increased pressure. The absorption tower may be of any type such as a packed type, a tray type, a multi-tube type, a spray type, a wet wall type or a combination of these.

Furthermore, FIG. 1 shows a series of flow sheets showing one embodiment of the method of the present invention, and the method of collecting the aziridine compound of the present invention will be specifically described with reference to this figure.

The raw material alkanolamine is supplied to the evaporator 101 through the line 1 and heated to be vaporized. If necessary, an inert gas such as nitrogen, helium, or argon is supplied to the evaporator 101 from the line 2 together with ammonia, water vapor, hydrogen, etc. for the purpose of suppressing side reactions, to adjust the alkanolamine concentration. . Line 3 of this source gas mixture
To the gas-phase dehydration reactor 102 filled with the catalyst.
The type of the reactor 102 may be a general fixed bed type, fluidized bed type or moving bed type. The composition of the reaction product discharged from the reactor 102 is an aziridine compound, an unreacted alkanolamine, water, a carbonyl compound, and various amine compounds, except for an inert gas that is a raw material gas diluent. The reaction product is sent to cooler 103 via line 4,
Here, after cooling to an appropriate temperature, it is introduced into the lower part of the absorption tower 104 through the line 5. The absorption tower is packed with an appropriate packing inside, and an absorption liquid composed of a liquid amine compound or its aqueous solution is supplied from the upper part through a line 6 to contact the introduced reaction product on the packing. It is designed to absorb reaction products. The unabsorbed gas composition is in the absorption tower
While being discharged from the top of the tower 104 via line 7, the bottom liquid having absorbed the aziridine compound is discharged via line 8. In this way, the aziridine compound is collected from the gas phase intramolecular dehydration reaction product of the alkanolamine.

After this, the liquid in which the aziridine compound is collected can be distilled for purification. In the case of FIG. 1, the collected liquid is sent to the distillation column 105 and distilled. In this apparatus, if necessary, an amine compound can be added to the collection liquid from the line 9 and an amine compound can be added to the distillation column from the line 10 provided above the collection liquid supply stage. A high-purity aziridine compound is obtained from the top of the column through line 11, while high-boiling substances such as water, amine-carbonyl adduct, unreacted alkanolamine and added amine compound are withdrawn through line 12 from the bottom of the column.
If necessary, alkanolamine and amine compound are separately collected.

[Effect of the present invention] According to the present invention, by the effect of the amine compound, the by-product carbonyl compound is made into a stable adduct with the amine compound while suppressing the polymerization of the aziridine compound, thereby reducing the yield of the aziridine compound. It can be prevented and collected. Further, when the aziridine compound is purified by further distillation, it is possible to easily obtain a high-purity aziridine compound containing no carbonyl compound in a high yield.

Further, since the absorption liquid in which the aziridine compound is dissolved can be continuously taken out from the bottom of the absorption tower, continuous operation can be performed.

[Examples] Hereinafter, the present invention will be described in more detail with reference to Examples. The apparatus shown in FIG. 1 was used in each example. The composition analysis was carried out using a gas chromatograph for amine compounds, aziridine compounds, carbonyl compounds and amine-carbonyl adducts, and with a Karl Fischer moisture meter for water. In addition, the collection rate of the aziridine compound in the collection step complies with the following definition.

Example 1 (1) Preparation of catalyst A catalyst was prepared according to Example 13 described in European Patent Publication No. 227,461.

Silicon oxide 300g, barium hydroxide (octahydrate) 788.7g,
10.0 g of sodium hydroxide and 6.2 g of zirconium oxide were suspended in 3 l of water, and heated and concentrated with sufficient stirring to obtain a white clay-like substance. This was molded into a cylindrical pellet having an outer diameter of about 5 mm and a length of about 5 mm, dried and calcined at 600 ° C. for 2 hours to obtain a catalyst having a composition of Si _1.0 Ba _0.5 Na _0.05 Zr _{0.01 in} terms of atomic ratio excluding oxygen. .

(2) Dehydration reaction step 200 ml of this catalyst was filled in a stainless steel reaction tube having an inner diameter of 25 mm installed in the reactor 102 and heated to 390 ° C. with a heating medium.
A raw material mixed gas with a volume ratio of monoethanolamine: nitrogen = 10: 90 was passed from the evaporator 101 into the tube at a space velocity of 1500 hr ⁻¹ to carry out a reaction. From the analysis results, the reaction product is monoethanolamine 3.6% by volume, ethyleneimine 4.9% by volume,
It contained 5.0% by volume of water, 0.3% by volume of acetaldehyde, 85.5% by volume of nitrogen, and a small amount of ammonia, monoethanolamine double compound, and the like.

(3) Collection process The reaction product discharged from the vapor phase dehydration reaction process is cooled by a cooler 10
It was cooled to 110 ° C. through 3 and introduced into the lower part of the absorption tower 104 made of a stainless steel tube having an inner diameter of 25 mm and a length of 1000 mm. Inside the absorber, 3 mmφ packing (Dickson packing) is packed with a bed height of 700 mm. The monoethanolamine heated from the top of the absorption tower through line 6 to 40 ° C
The liquid was supplied into the tower at a flow rate of 980 g / hour, brought into contact with the reaction product, and the liquid after absorption (hereinafter referred to as the collected liquid) was extracted from the bottom of the absorption tower. The collection rate of ethyleneimine was calculated from the analysis results of the collected liquid, and the amount of ethyleneimine produced in the reaction step was
It was confirmed that 9.6% was absorbed by monoethanolamine. In addition, acetaldehyde produced as a by-product in the reaction step does not exist in the collection liquid, and an amount of N-ethylidene-1-hydroxyethylamine (a reaction product of acetaldehyde and monoethanolamine of the absorption liquid) corresponding to this does not exist. confirmed.

Examples 2 to 6 The absorption liquid was changed, and further, in Example 4, the temperature of the absorption liquid, Example 5
For Nos. 6 to 6, the supply amount of the absorption liquid was changed, and the other steps were the same as in Example 1 except that the reaction step and the collection step of ethyleneimine were performed. The respective collection conditions and the results are shown in Table 1.

Example 7 A catalyst was prepared according to Example 3 described in US Pat. No. 4,477,591.

(1) Preparation of catalyst 20 g of niobium pentoxide was added to 200 ml of warm water with stirring to dissolve it, and then aqueous ammonia was added to adjust the pH of the solution to 7.0. Excess precipitate formed, washed with water, 10% by weight oxalic acid aqueous solution 32
After dissolving in 0 ml, 0.8 g of barium hydroxide (octahydrate) was added. Silicon carbide 240cc with a diameter of 5 mm in this solution
Was dipped, evaporated to dryness, and calcined in an air stream at 500 ° C. for 3 hours to obtain a supported catalyst (atomic ratio of Nb _1.0 Ba _0.1 O _2.6 ) containing 3.7% by weight of niobium pentoxide and 0.5% by weight of barium oxide.

(2) Dehydration reaction step Using this catalyst, a dehydration reaction step was carried out in the same manner as in Example 1 except that the reaction temperature was changed to 420 ° C. From the analysis results, the reaction product contains 6.5% by volume of monoethanolamine, 2.1% by volume of ethyleneimine, 2.5% by volume of water, 0.7% by volume of acetaldehyde, 87.3% by volume of nitrogen and a small amount of ammonia, dimer of monoethanolamine, etc. It was a thing.

(3) Collection step Subsequently, the ethyleneimine collection step was performed in the same manner as in Example 1. The collection conditions and the results are shown in Table 1.

Example 8 A catalyst was prepared according to Example 25 described in European Patent Publication No. 230,776.

(1) Preparation of catalyst 900 g of aluminum nitrate (9-hydrate) was dissolved in 2.4 l of water, and a solution of 357.6 g of triammonium phosphate in 2.4 l of water was added with stirring. After the obtained precipitate is washed with water,
73.6 g of barium oxide and 100 ml of water were used and kneaded well. The obtained clay-like substance is molded into a cylindrical pellet having an outer diameter of about 5 mm and a length of about 5 mm, dried and calcined at 1000 ° C. for 2 hours to obtain a catalyst having a composition of Al ₁ P ₁ Ba _0.2 at an atomic ratio excluding oxygen. Obtained.

(2) Dehydration reaction step Using this catalyst, the reaction temperature was changed to 420 ° C., and the raw material mixed gas was mixed in a volume ratio of monoisopropanolamine: nitrogen = 20: 8.
The dehydration reaction step was performed in the same manner as in Example 1 except that the value was 0. According to the analysis results, the reaction product was 8.0% by volume of monoisopropanolamine, 7.9% by volume of 2-methylethyleneimine, 8.0% by volume of water, 1.2% by volume of acetone, 72.6% by volume of nitrogen and a small amount of ammonia and a dimerization product of monoisopropanolamine. Etc. were included.

(3) Collection step A 2-methylethyleneimine collection step was carried out in the same manner as in Example 1 except that monoisopropanolamine at 20 ° C. was used as the absorbing liquid and the supply rate was 2200 g / hour. The collection conditions and the results are shown in Table 1.

Example 9 (1) Preparation of catalyst Cesium carbonate 114.0 g, diammonium phosphate 92.4 g,
Magnesium hydroxide 17.4 g, thallium nitrate 26.6 g and aluminum oxide 255.0 g were added to water 2 l and the mixture was heated and concentrated to obtain a white clay-like substance. This is molded into a cylindrical pellet with an outer diameter of about 5 mm and a length of about 5 mm, dried, and then calcined in an air stream at 600 ° C for 2 hours, and the atomic ratio excluding oxygen is Mg _0.3 Cs _0.7 P _0.7 Tl _0.1
A catalyst having a composition of Al _5.0 was obtained.

(2) Dehydration reaction step Using this catalyst, the reaction temperature was changed to 400 ° C., and the raw material mixed gas was mixed in a volume ratio of 2-amino-1-butanol: nitrogen = 20: 8.
The dehydration reaction step was performed in the same manner as in Example 1 except that the value was 0. From the analysis results, the reaction product is 2-amino-1-
Butanol 9.1% by volume, 2-ethylethyleneimine 7.3% by volume, water 7.5% by volume, methyl ethyl ketone 1.4% by volume, nitrogen 73.0% by volume and a small amount of ammonia, 2-amino-1.
-Butanol dimer and the like were included.

(3) Collection step Subsequently, the 2-ethylethyleneimine collection step was performed in the same manner as in Example 1. The collection conditions and the results are shown in Table 1.

Example 10 (1) Preparation of catalyst A catalyst was prepared in the same manner as in Example 8.

(2) Dehydration reaction step This catalyst 1 was filled in a stainless steel reaction tube having an inner diameter of 25 mm installed in the reactor 102, and heated to 420 ° C. with a heating medium.
The monoethanolamine was supplied to the evaporator 101, and the vaporized monoethanolamine was fed into the reaction tube and the reaction tube outlet pressure 10
The reaction was carried out at ⁰ mmHg and a space velocity of 400 hr ^-1 . From the analysis results, the reaction product is monoethanolamine 42.4% by volume,
It contained 24.7% by volume of ethyleneimine, 27.1% by volume of water, 1.8% by volume of acetaldehyde and a small amount of ammonia, a dimerized product of monoethanolamine and the like.

(3) Collection step The reaction product discharged from the dehydration reaction step is first cooled to normal temperature with cooling water, and then cooled to −10 ° C. using a refrigerant to be condensed and collected to obtain a solution containing ethyleneimine. Obtained. From the analysis result of the collected liquid, it was confirmed that 99.6% of the ethyleneimine produced in the reaction step was collected. In addition, acetaldehyde produced as a by-product in the reaction step was not present in the collected liquid, and an amount of N-ethylidene-1-hydroxyethylamine corresponding to this was confirmed.

In the dehydration reaction step of Example 10, the reaction product gas does not contain an inert gas because the starting material monoethanolamine is reacted without being diluted with an inert gas such as nitrogen. Therefore, the target product, ethyleneimine, in the reaction product gas can be collected more easily than in the case where an inert gas is contained, and it is also possible to collect the aggregated product as described above. However, the present invention is not a flocculation and collection method, but a method using an absorption tower in which a reaction product gas in a gaseous state is introduced into the absorption tower and brought into contact with an absorption liquid. The reaction product gas of this Example 10 is also introduced into the absorption tower in the same manner as in Examples 1 to 9 and is contacted with the same absorption liquid as those of these Examples to efficiently collect the target product ethyleneimine. I was able to.

Here, when the molar ratio of the amine to the carbonyl compound in the absorption tower is calculated from the data of the example, it becomes as shown in Table 2. The numerical value of each item in Table 2 was calculated as follows. The first embodiment will be described as an example.

Reaction supply amount: Total amount of supply gas = 200 ml x 1500 hr ^-1 = 300,000 ml / hr = 300 l / hr When this is converted to the number of moles, 1 mol = 22.4 l, so 300 l / hr / 22.4 l / mol = 13.39 mol / hr Since the raw material concentration is 10% by volume (= 10 mol%), the feedstock is 13.39 mol / hr × 10/100 = 1.339 mol / hr Amount of carbonyl compound produced: The carbonyl compound (acetaldehyde) in the produced gas is
Since it is 0.3% by volume, 13.39 mol / hr x 0.3 / 100 = 0.04 mol / hr amine amount: the unreacted amine amount is the same as the above carbonyl compound amount calculated. Since the amine concentration in the produced gas is 3.6% by volume, 13.39 mol / hr x 3.6 / 100 = 0.482 mol / hr The amount of amine supplied to the absorption tower is 980 g / hr, so if this is divided by the molecular weight of 61.07, , 980g / hr / 61.07g / mol = 16.05mol / hr When both are added, 16.05 + 0.482 = 16.5mol / hr Ratio of amine and carbonyl compound Amine amount calculated above The amount of carbonyl compound generated above It is divided by.

16.5 / 0.04 = 411 Reference Example 1 This reference example shows an example in which an aziridine compound was distilled and purified from a solution in which the aziridine compound was collected by the collection method of the present invention.

The solution obtained by collecting the ethyleneimine obtained in the collecting step of Example 10 was filled with 6.35 mm (McMahon packing).
A distillation column consisting of a stainless steel tube with an inner diameter of 50 mm and a height of 2000 mm filled with 400 mm in the concentration part and 1200 mm in the recovery part.
It was introduced at about 1/3 from the top of 105 and distilled at a reflux ratio of 4. The yield of ethyleneimine produced by the reaction from the top of the distillation column was 99.0%, and the purity of ethyleneimine was 98.3% by weight.
267 g was obtained per hour.

Comparative Example The following experiment was conducted to show the collection efficiency in the cooling trap.

50 g of the same catalyst used in Example 1 was ground to 3-5 mesh. 20 ml of it was filled in a stainless steel reaction tube having an inner diameter of 16 mm and then immersed in a molten salt bath heated to 390 ° C. Monoethanolamine: Nitrogen = 10:90 in this reaction tube
The raw material mixed gas of was passed through at a space velocity of 1500 hr ⁻¹ to carry out the reaction. The gas flow rate was 500 ml / min under standard conditions. From the analysis results, the reaction product gas component is monoethanolamine 3.
The content was 5% by volume, 4.9% by volume of ethyleneimine, 5.1% by volume of water, 0.3% by volume of acetaldehyde, 85.4% by volume of nitrogen, and a small amount of a dimer of ammonia or monoethanolamine.

The outlet gas of this reaction tube was introduced to and collected by connecting three cooling traps having an internal volume of 200 ml. The temperature of the cooling medium for cooling the trap was changed to 40 ° C., 0 ° C., −10 ° C. and −77 ° C., and each trap was collected for 2 hours. Table 3 shows the results of the collection efficiency of each ethyleneimine. From this result, when the trap temperature is set to -77 ° C. in the dry ice / methanol bath, the collection efficiency of ethyleneimine is considerably improved, but this is not sufficient compared with the collection efficiency of 99% or more in the examples. . Further, at such a low temperature, the liquid in the trap may solidify and the trap may be clogged, and the cost of the refrigerant increases, which makes it difficult to carry out the process industrially.

The liquid in the trap can be handled in a liquid state-10
Above 0 ° C, ethyleneimine is considerably lost along with nitrogen gas, and the collection efficiency is considerably reduced.

[Brief description of drawings]

FIG. 1 is a flow sheet showing a process for collecting an aziridine compound according to the present invention. 1 ... Raw material alkanolamine supply line 2 ... Diluting gas supply line 6 ... Absorption liquid supply line 7 ... Exhaust gas line 8 ... Collection liquid extraction line after absorption 9 ... Amine compound addition line 10 ... Amine Compound addition line 11 …… Aziridine compound distillate extraction line 101 …… Evaporator 102 …… Reactor 103 …… Cooler 104 …… Absorption tower 105 …… Distillation tower

 ─────────────────────────────────────────────────── ─── Continuation of the front page (31) Priority claim number Japanese Patent Application No. Sho 62-156617 (32) Priority date Sho 62 (1987) June 25 (33) Country of priority claim Japan (JP) (31) Priority Claim Number Japanese Patent Application No. Sho 62-265443 (32) Priority Date Sho 62 (1987) October 22 (33) Country of priority claim Japan (JP) Judgment No. Hei 5-20983 (72) Inventor Hideaki Tsuneki Suita Osaka Prefecture 5-8 Nishimitabicho, Nishimibata-shi, Japan (72) Inventor Yutaka Morimoto 14-1 Chidori-cho, Kawasaki-ku, Kawasaki-shi, Kanagawa Nihon Catalysis & Chemical Industry Co., Ltd. (72) Invention Researcher Rikuo Ueshima 5-8 Nishiomitabicho, Suita City, Osaka Prefecture Central Research Laboratory of Nippon Shokubai Kagaku Kogyo Co., Ltd. (56) References Japanese Patent Publication Sho 50-10593 (JP, B1)

Claims (3)

[Claims] 1. A general formula (R is hydrogen, a methyl group or an ethyl group. X is OH or NH ₂ , Y is NH ₂ when X is OH, and O when X is NH ₂ .
H. ) Is subjected to a gas phase intramolecular dehydration reaction in the presence of a catalyst to give a general formula (R is the same as the formula (I)), a reaction step for producing an aziridine compound represented by the formula, and the reaction product gas that has passed through the reaction step is introduced into an absorption tower, and the reaction product gas supply position in the absorption tower. An absorption liquid of an amine compound or a solution thereof at 0 to 80 ° C. is supplied from above to bring it into contact with the reaction product gas, and the aziridine compound in the reaction product gas is dissolved in the absorption liquid and collected. And a method for producing an aziridine compound, comprising: 2. The production of an aziridine compound according to claim 1, wherein the amount of the amine compound for absorbing liquid supplied per unit time is equal to or more than the equimolar amount of the amount of carbonyl compound produced per unit time in the reaction product gas. Method. 3. The method for producing an aziridine compound according to claim 1, wherein an alkanolamine as a reaction raw material is used as the amine compound for the absorbing liquid.