JPH09227515A - Production of n-chlorosuccinimide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To economically and advantageously produce a high-purity N- chlorosuccinimide useful as a germicide or a chlorinating agent for a reactional reagent in high yield without causing pollution. SOLUTION: Chlorine gas is blown into an aqueous solution of succinimide under stirring and reacted therewith, preferably at 15-25 deg.C for 3-5hr to afford the objective N-chlorosuccinimide. The concentration of the succinimide in the aqueous solution at this time is preferably 10-15wt.% and the blowing rate of the chlorine gas blown into the aqueous solution is preferably 0.24-0.4mol/hr based on 1mol succinimide. The objective compound is obtained without forming by-products of salts such as t-butyl acetate and without producing waste liquors as an industrial wastes according to the reaction.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for producing N-chlorosuccinimide, which is used as a chlorinating agent in a reaction reagent and which has recently been promising in the field of bactericides.

[0002]

2. Description of the Related Art Conventionally, as a method for producing N-chlorosuccinimide, succinimide is used at a low temperature in acetic acid or an inorganic acid solvent by using a chlorinating agent such as an ester of hypochlorous acid or an alkali metal salt of hypochlorous acid. A method of chlorinating is known. For example, Journal of American Society (JACS) Vol 76, 3857 (195
According to 4), using t-butyl hypochlorite as a chlorinating agent and reacting with succinimide in an acetic acid solvent at 0 ° C.,
N-chlorosuccinimide is obtained with a yield of 31%.
In addition, Berich Vol 34, 4213 (1
According to 901), potassium hypochlorite is used to react with succinimide in an acetic acid solvent at 0 ° C. to obtain N-chlorosuccinimide in a yield of 85%. Further, according to JP-A-4-282,362, sodium hypochlorite or the like is used as a chlorinating agent and reacted with succinimide in an inorganic acid solvent such as hydrochloric acid at 10 ° C. or lower to give a yield of 85%. N-chlorosuccinimide is obtained.

However, in the above-mentioned method, it is necessary to use a large amount of acetic acid or an inorganic acid as a solvent, and although a large heat of reaction is generated, N-chlorosuccinimide must be used unless the reaction is carried out at a low temperature of 10 ° C. or lower. Yield is reduced. Therefore, if this production method is to be carried out on an industrial scale, a special cooling facility (chiller unit) is required to remove the reaction heat and maintain the reaction temperature, which causes a problem of excessive facility cost. Further, in N-chlorosuccinimide, t-butyl acetate, potassium acetate, NaCl, which is a by-product of the reaction and cannot be completely removed by the washing operation,
Etc. remain as impurities, which is not preferable in terms of quality, and the residual liquid from which N-chlorosuccinimide has been separated contains these impurities in addition to acetic acid or inorganic acid used as a solvent. There's a problem.

[0004]

DISCLOSURE OF THE INVENTION The present invention relates to a method for producing N-chlorosuccinimide by chlorinating succinimide, which is economically advantageous and does not cause pollution, and thus provides a high yield and high purity. It is an object of the present invention to provide a method for producing N-chlorosuccinimide.

[0005]

Means for Solving the Problems As a result of earnest studies on a method for producing N-chlorosuccinimide, the present inventors have studied the room temperature by reacting succinimide with chlorine gas in water without using acids as a solvent. The present invention has been completed by finding a production method capable of producing high-purity N-chlorosuccinimide having a good hue in a high yield even in the reaction in the vicinity and producing no waste water from the reaction system.

That is, according to the present invention, there is provided a method for producing N-chlorosuccinimide, which comprises reacting succinimide with chlorine gas in water.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The succinimide used as a reaction raw material in the present invention may be a commercially available anhydrous product, and
It may be a hydrous succinimide produced using succinic acid or succinic anhydride and aqueous ammonia.

To preferably carry out the method of the present invention, chlorine gas is blown into an aqueous solution of succinimide with stirring. The reaction temperature is 0 to 35 ° C, preferably 15 to 25 ° C. When the temperature exceeds 35 ° C, the N-chlorosuccinimide is decomposed, so that the yield is significantly reduced, and a part of chlorine gas blown into the aqueous solution is scattered without participating in the reaction. The reaction time is generally 2 hours or longer, preferably 3 to 5 hours. The concentration of succinimide in the aqueous solution is 5 to 25% by weight, preferably 10 to 15% by weight. In addition, the blowing rate of chlorine gas blown into this aqueous solution was as follows, per mol of succinimide contained in the aqueous solution:
0.1 to 0.6 mol / hour, preferably 0.24 to 0.4
Mol / hour. If the blowing rate of chlorine gas is lower than this range, the reaction takes a long time, which is not economical. On the other hand, if it exceeds the above range, chlorine gas scatters without participating in the reaction, which is not preferable.

By the above-mentioned reaction operation, succinimide reacts with chlorine in water to produce N-chlorosuccinimide, and this N-chlorosuccinimide is deposited as crystals in the reaction solution after the reaction is completed. Crystals of N-chlorosuccinimide can be separated and collected by solid-liquid separating the reaction solution.

In the present invention, since chlorine gas is used as the chlorinating agent, unlike the conventional method, there is no by-product of salts such as tert-butyl acetate, potassium acetate and sodium chloride. Therefore, the obtained crystals of N-chlorosuccinimide can be easily washed, and a high-purity product can be obtained in good yield. Further, the filtrate after separating the crystals of N-chlorosuccinimide contains hydrochloric acid that is a by-product of the reaction, and this can be effectively used as a by-product hydrochloric acid.
Therefore, in the case of the present invention, since a waste liquid as industrial waste is not generated, the present invention can be said to be an excellent technique from the viewpoint of pollution prevention.

Further, in the case of the present invention, the amount of heat generated by the reaction between succinimide and chlorine gas is small, and it is not necessary to use special cooling equipment. According to the calculation of the present inventors, for example, when 1 mol of sodium hypochlorite is reacted with 1 mol of succinimide in hydrochloric acid, an exothermic heat of 470 kJ is generated, whereas according to the present invention, 1 mol of chlorine is generated.
When moles are reacted with 1 mole of succinimide in water, it has a remarkably low heating value of 230 kilojoules.

[0012]

Next, the present invention will be described in more detail with reference to examples.

Example 1 A four-necked flask equipped with a thermometer, a stirring rod, a chlorine gas injection tube and a condenser was prepared, and a chlorine absorption tower was connected to the condenser outlet with a hose. In the flask, commercially available succinimide (purity 99.96%): 49.9 g
(0.5 mol) and ion-exchanged water: 448.9 g were charged, and the flask was set in the cooling tank. Tap water was poured into the cooling tank to stir while cooling the flask to dissolve the succinimide. While keeping the temperature in the flask at 20 ° C., chlorine gas was blown into the flask at a rate of 45 ml / min,
Succinimide was reacted with chlorine. The reaction time was 5 hours and 42.6 g (0.6 mol) of chlorine was used.
Then, while maintaining the temperature in the flask at 20 ° C, 30
The mixture was aged for a minute, and the chlorine gas remaining in the flask during this was purged with nitrogen gas. Filter the crystals in the flask,
85 g of wet crystals and 447 g of filtrate were obtained. 20 wet crystals
Wash with 250 g of ion-exchanged water at ℃,
By drying at 00 ° C., 54.5 g of N-chlorosuccinimide was obtained. The yield is 81.0% and the purity is 99.
2%, NaCl content 10 ppm, melting point 149-1
It was 51 ° C. The hydrochloric acid concentration in the separated filtrate was 5.
1%.

Example 2 The chlorine gas blowing rate was 75 ml / min, and the reaction time was 3
An experiment was conducted in the same manner as in Example 1 except that the time was set. The yield of the obtained N-chlorosuccinimide was 82.1%, the purity was 98.8%, the NaCl content was 14 ppm, and the melting point was 1.
It was 49-151 degreeC. The hydrochloric acid concentration in the separated filtrate was 5.2%.

Example 3 An experiment was carried out in the same manner as in Example 1 except that hydrous succinimide (water content 16%, 0.5 mol) synthesized from succinic acid and aqueous ammonia was used. The yield of the obtained N-chlorosuccinimide was 80.5%, and the purity was 99.2%.
The NaCl content was 10 ppm, and the melting point was 149 to 151 ° C. The hydrochloric acid concentration in the separated filtrate was 5.4%.

Example 4 An experiment was conducted in the same manner as in Example 1 except that the reaction temperature was 35 ° C. The yield of the obtained N-chlorosuccinimide was 61.1%, the purity was 99.2%, and the content of NaCl was 11.
ppm, melting point was 148 to 151 ° C. The hydrochloric acid concentration in the separated filtrate was 4.9%.

Comparative Example 1 A four-necked flask equipped with a thermometer, a stir bar, a condenser, and a sodium hypochlorite injection port was placed in a commercially available succinimide (purity 99.96%): 99.1 g (1 mol) and 20.
% Hydrochloric acid: 200.6 g (1.1 mol) was charged, the flask was set in the cooling tank and stirred to dissolve succinimide. In order to remove the generated heat of reaction, the cooling water is circulated in the cooling tank by the cooling constant temperature circulation device to increase the temperature in the flask to 2
Sodium hypochlorite (available chlorine 10.
662.7 g (1 mol) of 7%) was injected into the flask with a metering pump. The injection time was 3 hours. 3 at 20 ° C
The mixture was aged for 0 minutes and the crystals in the flask were filtered to obtain 149.5 g of wet crystals and 801.9 g of filtrate. 2 wet crystals
The crystals were washed with 500 g of ion-exchanged water at 0 ° C., and then the crystals were placed in a vacuum dryer and dried at 5 to 10 Torr and 70 ° C. The obtained N-chlorosuccinimide was 79.3 g. Yield 58.4%, purity 98.3%, NaC
The l content was 200 ppm, and the melting point was 148 to 151 ° C.

Comparative Example 2 The reaction temperature was 10 ° C. and the temperature of ion-exchange water for cleaning was 10 ° C.
The same procedure as in Comparative Example 1 was carried out except that The obtained N-
The yield of chlorosuccinimide is 79.3%, and the purity is 9
8.8%, NaCl content 210ppm, melting point 14
It was 8 to 151 ° C.

[0019]

According to the present invention, high-purity N-chlorosuccinimide containing less impurities as compared with the conventional method can be obtained in high yield. Moreover, in the case of the present invention, there is no generation of waste water that causes pollution, and the heat generation during the reaction is smaller than that in the conventional method, and the use of a special cooling device is not required.

Claims (2)

[Claims] 1. A method for producing N-chlorosuccinimide, which comprises reacting succinimide with chlorine gas in water. 2. A method for producing N-chlorosuccinimide, which comprises blowing chlorine gas into an aqueous solution of succinimide.