JPS624380B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method for purifying and concentrating quaternary ammonium compounds. More specifically, the present invention involves adding an alkali metal or alkaline earth metal hydroxide to a low concentration aqueous solution of a quaternary ammonium compound, which may contain salts as impurities, to form a concentrated aqueous solution of a quaternary ammonium compound. This is a method for purifying and concentrating a quaternary ammonium compound, which is characterized by forming two layers: a layer consisting of an aqueous solution of an alkali metal or an alkaline earth metal hydroxide, and then separating the layers. Quaternary ammonium compounds are used in a wide range of applications in the chemical industry, including disinfectants, emulsifiers, rust preventives, and mineral flotation agents. In addition, in recent years, in the organic synthetic chemical industry, the amount used has been increasing as a reaction catalyst, solubilizing agent, or solvent for purposes such as improving reaction yield, controlling selectivity, or improving product purity. By the way, quaternary ammonium compounds are not only industrially expensive, but also have a fear of environmental pollution because some of them are highly toxic to living organisms if discharged outside the reaction system. A fourth like this
Regarding the recovery method of grade ammonium compounds, extraction method with organic solvent (for example, Japanese Patent Application Laid-Open No.
144485) is known, but it is not an industrially advantageous method because it involves the complexity of handling organic solvents and it is difficult to obtain a highly concentrated quaternary ammonium compound solution. The present inventors conducted intensive studies to find a method for selectively concentrating and recovering quaternary ammonium compounds from the waste liquid containing them. As a result, when a certain amount of alkali was added, only quaternary ammonium compounds were selected. They discovered that it can be separated from waste liquid as a highly concentrated aqueous solution, and completed the present invention. According to the method of the present invention, the separated high-concentration aqueous solution of the quaternary ammonium compound contains almost no added alkali or inorganic salts contained as impurities, and can be recovered at a high yield. Figure 1 shows the mutual solubility of the benzyltriethylammonium chloride-sodium hydroxide-water system measured at 25°C. In Figure 1, the equilibrium curve is indicated by 〓〓〓〓,
At compositions above this, the system is homogeneous, but at compositions below this, the system separates into two liquid phases. For example, the composition at point P (20% benzyltriethylammonium chloride, 15% sodium hydroxide, 65% water) is the same as the composition at point Q (1.6% benzyltriethylammonium chloride, 20.7% sodium hydroxide, 65% water).
77.7%) and an oil layer having the composition of point R (56.4% benzyltriethylammonium chloride, 3.6% sodium hydroxide, 40.0% water). The present inventors have arrived at the present invention based on such knowledge. The low concentration aqueous solution (hereinafter referred to as stock solution) containing a quaternary ammonium compound, which is the target of the present invention, mainly refers to a solution obtained after various chemical reactions are carried out in the presence of a quaternary ammonium compound and the target substance has been separated. It is waste liquid. Any type of reaction and any conditions may be used. This also includes cases where the object of the reaction is the quaternary ammonium compound itself. In that case, the target is the liquid containing the target substance. Moreover, the stock solution can be applied even before separating the target product of the reaction. When the reaction system contains water, the stock solution is used as the waste liquid after the reaction is completed, after separation by solid-liquid separation if the target product of the reaction is a solid, or as an organic It can be obtained as an aqueous layer by adding a solvent and extracting and separating the target product. In addition, when the reaction system contains an organic solvent, the stock solution is extracted and separated by adding water to the organic solvent layer after solid-liquid separation if the reaction target is a solid after the reaction is completed. or, if the target substance is dissolved in an organic solvent, add water to it and extract and separate the layers, or after removing the organic solvent by distillation etc. In addition, the rest can be obtained as a waste liquid (aqueous layer) obtained in the same manner as in the treatment of systems containing water. In addition, when the target product of the reaction is the quaternary ammonium compound itself, the stock solution is generally prepared using an organic solvent, so after the reaction is completed, water is added to the reaction solution for extraction and separation. Alternatively, it can be obtained as an aqueous solution by distilling the organic solvent in the reaction solution and then adding water. Salts that may be contained in the stock solution include, for example, alkali metal, alkaline earth metal, or ammonia sulfates, carbonates, phosphates, sulfites, bicarbonates, nitrates, monohydrogen phosphates, and phosphorus. Acid dihydrogen salts, hydrogen sulfates, cyanates, thiocyanates or fluorides, chlorides, bromides, iodides,
Examples include inorganic salts such as cyanide, and organic acid salts such as acetate, succinate, and benzoate. It may also be a mixture of these. There is no problem even if the stock solution contains salts such as those mentioned above. Although some organic substances other than quaternary ammonium compounds may be included, it is better to remove those that can be removed by extraction, acid precipitation, activated carbon treatment, etc. in order to obtain a highly pure quaternary ammonium compound. It's convenient. Reacting in an organic solvent When using an alkali, it is partially neutralized during water extraction to reduce the alkali concentration to 5%.
Hereinafter, it is desirable to keep it preferably 1% or less. In the present invention, the quaternary ammonium compound has the general formula () or () (In the formula, R ₁ and R ₂ are an alkyl group having 1 to 24 carbon atoms or an optionally substituted benzyl group,
R ₃ and R ₄ are alkyl groups having 1 to 10 carbon atoms, and X represents an anion residue. ) (In the formula, R ₅ is an alkyl group having 1 to 24 carbon atoms, R ₆ is a hydrogen atom or a methyl group, and X has the meaning described above.) In addition to chlorine, bromine, and iodine, the anion residues in the general formula include sulfate, phosphate, acetate, methyl sulfate, ethyl sulfate, perchlorate, and hydrogen sulfate residues. . Specific examples of quaternary ammonium compounds include the following compounds. Tetra-n-butylammonium chloride Tetra-n-propylammonium chloride Tetraethylammonium chloride Tetramethylammonium chloride Stearyltrimethylammonium chloride Trimethyloctadecyl ammonium chloride Trimethylhexadecyl ammonium chloride Distearyl dimethyl ammonium chloride Dicetyl dimethyl ammonium chloride Tricapryl methyl ammonium chloride o・m or p-methoxybenzyltriethylammonium chloride o・m or p-phenoxybenzyltriethylammonium chloride N-butylpyridium chloride laurylpyridium chloride laurylpicolinium chloride triethylpropylammonium chloride diethylpropylbenzylammonium chloride trimethylbenzylammonium chloride Triethylbenzylammonium chloride o/m or p-chlorobenzyltriethylammonium chloride Methylethylpropylbenzylammonium chloride Diethylbutylbenzylammonium chloride Methyldiethylbenzylammonium chloride Dimethylethylbenzylammonium chloride Tripropylbenzylammonium chloride Ethyldipropylbenzylammonium chloride Diethyl dibenzyl Ammonium chloride Dimethyllaurylbenzylammonium chloride Stearylbenzylmethylammonium chloride Octylbenzyldimethylammonium chloride and their corresponding bromides, iodides, sulfates, perchlorates, phosphates sulfates, acetates, methyl sulfates, ethyl sulfates, or mixtures thereof. The hydroxides of alkali metals or alkaline earth metals used in the present invention include sodium hydroxide, potassium hydroxide, lithium hydroxide, calcium hydroxide, magnesium hydroxide, barium hydroxide, etc., and are particularly preferably used. Sodium hydroxide and potassium hydroxide are used. The larger the amount of alkali added, the higher the distribution ratio of the quaternary ammonium compound to the oil layer, but if it is too large, it is not economically advantageous. Therefore, although it varies depending on the type of quaternary ammonium compound to be purified, the alkali concentration of the entire system is usually adjusted to 5 to 25 percent by weight, preferably 10 to 20 percent by weight. Specifically, the method of the present invention can be carried out as follows. The alkali of the present invention is added to the stock solution obtained as described above and stirred. The lower the temperature, the higher the distribution rate of the quaternary ammonium compound into the oil layer, so it is preferably as low as possible within the range allowed by the solubility of the alkali, usually -20 to 80°C, preferably is in the range of -20 to 30°C. After stirring, when the mixture is allowed to stand still, it separates into an oil layer that mainly contains quaternary ammonium compounds and almost no salts or alkalis, and an aqueous layer that mainly contains salts or salts and alkalis. In this way, most of the quaternary ammonium compounds can be recovered as an oil layer. At this time, the amount of quaternary ammonium compounds remaining in the water layer is generally small, but
If necessary, use the method disclosed in Japanese Patent Application Laid-Open No. 53-144485,
A water-immiscible organic solvent can be added to the aqueous layer to extract the quaternary ammonium compound into the organic solvent layer. Furthermore, if necessary, the quaternary ammonium compound can be back-extracted from the organic solvent layer using acidic water. Examples of water-immiscible organic solvents used to recover small amounts of quaternary ammonium compounds include chloroform, carbon tetrachloride, halogenated hydrocarbons such as monochlorobenzene, dichlorobenzene, and benzyl chloride, and acetic acid. Carboxylic acid esters such as isoamyl and isobutyl acetate,
Examples of quaternary ammonium compounds include ketones such as methyl isopropyl ketone and methyl isobutyl ketone, nitriles such as isobutyl nitrile and isopentyl nitrile, and alcohols such as n-octyl and 2-ethyl-1-hexanol. It may be selected as appropriate. Alternatively, one of the raw materials for the quaternary ammonium compound may be used as the extraction solvent. Further, it may be a mixture of the above-mentioned solvents. The quaternary ammonium compound obtained in the present invention is usually obtained as a 30-80% concentrated aqueous solution. Further, according to the method of the present invention, the quaternary ammonium compound can be almost completely recovered, which is economically advantageous, and the problem of environmental pollution is also solved, so the present invention has great industrial value. The present invention will be explained in more detail with reference to Reference Examples and Examples below. In the text, parts represent parts by weight. Reference example 1 [Preparation of stock solution] Benzyltriethylammonium chloride 360
90.9% pure 1.
4-diamino-anthraquinone-2-sulfonic acid
110.0 parts were added under stirring, and the pH was then adjusted to 7.0 with a 28% aqueous sodium hydroxide solution, followed by stirring at room temperature until everything was dissolved. Next, 30 parts of nitrobenzene was charged, and then 382.1 parts of a 25% aqueous sodium cyanide solution was added dropwise. The mixture was heated to 85-90° C. with thorough stirring and allowed to react until most of the starting material disappeared by chromatography. During this time, the pH in the system was maintained at 9.0 to 9.5 using a 30% sulfuric acid aqueous solution. Excess sodium cyanide was then decomposed with 159 parts of 35% hydrogen peroxide solution, filtered, and the cake was washed with 500 parts of warm water and dried. Dark blue 1/4-
86.7 parts of crystalline powder of diamino-2,3-dicyanoanthraquinone was obtained. Mix the total amount of liquid and washing liquid, adjust the pH to 2.0 with 50% sulfuric acid aqueous solution, and add 30 parts of activated carbon.
Stir for 1 hour at <RTIgt;C,</RTI> and filter. 2300 parts of liquid was obtained. The composition of this solution (undiluted solution) was as shown in the table below.

[Table] Reference example 2 Lauryltrimethylammonium chloride 600
80.0% pure 1.
156.5 parts of 4-diamino-anthraquinone-2,3-disulfonic acid were charged with stirring and stirred at room temperature until all was dissolved. Then, after adjusting the pH to 7.0 using sodium carbonate, 305.6 parts of a 25% aqueous sodium cyanide solution was added dropwise. While stirring thoroughly, stir the mixture to 65-70 ml.
C. and allowed to react until most of the starting material disappeared by chromatography. During this time, the pH in the system was maintained at 9.0 to 9.5 using a 30% phosphoric acid aqueous solution. After the reaction is complete, excess sodium cyanide is decomposed with 152 parts of 35% hydrogen peroxide solution, filtered, and the cake is washed with 700 parts of warm water and dried to give a dark blue 1.
89.9 parts of crystalline powder of 4-diamino-2,3-dicyanoanthraquinone was obtained. Mix the total amount of liquid and washing liquid and adjust the pH with 50% sulfuric acid.
After adjusting to 1.5 and adding 30 parts of activated carbon, it was heated to 1 at 40℃.
The mixture was stirred for an hour and filtered to obtain 2220 parts of a stock solution. The composition of this liquid was as follows.

[Table] Reference example 3 45% by weight aqueous sodium hydroxide solution 177.7
part, tetra-n-butylammonium bromide
12.5 parts were charged into a reaction vessel and heated to 40-42°C. A solution of 75.6 parts of p-chlorobenzyl nitrile and 156.5 parts of isopropyl chloride was added dropwise thereto over 3 hours. After the dropwise addition, the reaction temperature was further stirred at 42°C and refluxed for 3 hours. After the reaction, 115.7 parts of water was added, stirred at 20°C for 20 minutes, left to stand for 20 minutes, and then separated into an oil layer and a water layer. The caustic soda concentration of the aqueous layer obtained here is
It was 20.07% and did not contain tetra-n-butylammonium bromide as a catalyst. Next, 62.5 parts of water was added to the oil layer, which was further neutralized to pH 6.5 to 7.5 using 48% sulfuric acid, stirred at 15° C. for 30 minutes, and left to stand for 30 minutes. The mixture was separated into an oil layer and an aqueous layer to obtain 87.5 parts of an aqueous layer (undiluted solution). The stock solution consists of 12.4 parts of tetra-n-butylammonium bromide and sodium sulfate.
Contained part 7.2. In addition, when the oil layer was concentrated, 97 parts of p-chloro-α-isopropylbenzyl nitrile was obtained as an oily substance. Reference Example 4 23.0 parts of benzyltriethylammonium chloride was added to 3000 parts of sodium hydroxide at a concentration of 50% by weight, heated from 40°C to 45°C, and a mixed solution of 750 parts of p-isobutylbenzyl cyanide and 680 parts of isopropyl bromide was It dripped in time. After the dropwise addition, the reaction mixture was further heated to 50 to 55°C for 6 hours. After cooling to below 50℃, add 6,500 parts of water, stir for 30 minutes, let stand for 30 minutes,
It was separated into an oil layer and an aqueous layer. The caustic soda solution in this aqueous layer was 20.0% and did not contain benzyltriethylammonium chloride as a catalyst. Next, 150 parts of water was added to the oil layer, and the pH was further neutralized to 6.5 to 7.5 using 48% sulfuric acid. After standing at 15°C for 30 minutes, the liquid was separated into an oil layer and a water layer, and 200 parts of water was added to the oil layer. An aqueous layer (undiluted solution) was obtained. The stock solution contained 22.9 parts of benzyltriethylammonium chloride and 10.5 parts of sodium sulfate. In addition, the oil layer was concentrated to give p-isobutyl-α-
910 parts of isopropylbenzylnitrile were obtained. Reference Example 5 250 parts of dichloromethane and 250 parts of a 2.4% aqueous sodium hydroxide solution were charged into a reaction vessel, and then 9.4 parts of phenol, 43 parts of benzyl-tri-n-butylammonium bromide, and 28.4 parts of methyl iodide were added under stirring at room temperature. was added and stirred at 25-30°C for 6 hours. After confirming the disappearance of phenol, let it stand for 30 minutes, separate the oil layer and the water layer, add 60 parts of water to the oil layer, stir and let it stand, then separate the aqueous layer, combine it with the first aqueous layer, and separate the oil layer and the water layer. 370 parts of an aqueous solution (stock solution) containing sodium iodide and 42.5 parts of benzyltri-n-butylammonium bromide were obtained. Note that 10.0 parts of phenyl methyl ether was obtained by concentrating the oil layer. Reference Example 6 250 parts of dichloromethane and 70 parts of 8.6% aqueous sodium hydroxide solution were charged into a reaction vessel, and then 12.4 parts of p-methoxyphenol, 5.8 parts of benzyltri-n-butylammonium bromide and 1.5 parts of dimethyl sulfate were added while stirring at room temperature. and incubate at 25-30℃ for 10
Stir for hours. After confirming the disappearance of p-methoxyphenol, let it stand for 30 minutes and separate into an oil layer and a water layer, and add 30% water to the oil layer.
After stirring and standing, the aqueous layer was separated and combined with the first aqueous layer to obtain 120 parts of an aqueous solution containing 5.6 parts of benzyltri-n-butylammonium bromide. In addition, when the oil layer was concentrated, 12.8 parts of p-methoxyphenyl methyl ether was obtained. Reference example 7 Distearylamine 52.1 parts, methyl chloride 10.1 parts
1 part and 4.0 parts of sodium hydroxide were charged into 400 parts of isopropyl alcohol, and the mixture was reacted at 80°C for 3 hours. Then, the isopropyl alcohol is removed by distillation,
Pour 325 parts of water to produce 15.0% distearyldimethylammonium chloride and by-product common salt.
390 parts of an aqueous solution (undiluted solution) containing 1.5% was obtained. Example 1 1500 parts of a 45% sodium hydroxide aqueous solution was gradually added to 2300 parts of the stock solution obtained in Reference Example 1 while stirring at 30°C, cooled to 5°C, and left to stand for 1 hour to separate into two layers. The oil layer and water layer were separated. The results shown in the table below were obtained.

【table】

[Table] Example 2 580 parts of 96% sodium hydroxide flakes were added little by little to 2220 parts of the stock solution obtained in Reference Example 2 at 30 to 40°C with good stirring, and the mixture was further stirred for 2 hours. After cooling to 5° C., the mixture was allowed to stand for 1 hour, and the liquid was separated to obtain the results shown in the table below.

[Table] Example 3 To 87.5 parts of the stock solution obtained in Reference Example 3, 65.6 parts of a 40% aqueous potassium hydroxide solution was added at 30°C, stirred at 10°C for 30 minutes, left to stand for 1 hour, and then separated. The results shown in the table below were obtained.

[Table] Example 4 200 parts of a 45% aqueous sodium hydroxide solution was added to 200 parts of the stock solution obtained in Reference Example 4, and the mixture was stirred at 10°C for 30 minutes.
After standing for a period of time, the liquid was separated. The results shown in the table below were obtained.

[Table] Example 5 To 370 parts of the stock solution obtained in Reference Example 5, 60 parts of sodium hydroxide was added at 15°C, stirred at 10°C for 30 minutes, left to stand for 1 hour, and then separated to form the solution shown in the table below. Got the results.

[Table] Example 6 To 120 parts of the stock solution obtained in Reference Example 6, 18 parts of sodium hydroxide was added at 15°C, stirred for 1 hour, allowed to stand for 1 hour, and then separated. The results shown in the table below were obtained.

[Table] Example 7 51 parts of sodium hydroxide was added to 390 parts of the stock solution obtained in Reference Example 7 with stirring at 30°C, and after cooling to 5°C, the mixture was allowed to stand for 1 hour and then separated. The following results were obtained.

[Table] Similar results can be obtained by performing the same treatment on a stock solution containing dicetylamine instead of distearylamine. Example 8 Benzyltriethylammonium chloride 347
parts, sodium sulfate 96.7 parts, ammonium sulfate 22 parts
45 parts to 2300 parts of stock solution containing 26.1 parts of sodium carbonate
% sodium hydroxide aqueous solution was gradually added at 30°C while stirring, cooled to 5°C and left to stand for 1 hour to separate into two layers, and the oil layer and water layer were separated to obtain the results shown in the table below. Ta.

[Table] A stock solution containing the corresponding bromide or iodide instead of benzyltriethylammonium chloride was treated in the same manner, and similar results were obtained. Example 9 1250 parts of a 45% sodium hydroxide aqueous solution was gradually added to 2300 parts of a stock solution having the same composition as in Example 8 while stirring at 35°C, and the mixture was allowed to stand at 20°C for 1 hour to separate into two layers, forming an oil layer. The mixture was separated into an aqueous layer and the results shown in the table below were obtained.

[Table] Next, 3000 parts of n-octanol was added to 3050 parts of the aqueous layer, and after stirring at 25°C for 1 hour, the mixture was allowed to stand still for liquid separation to obtain the results shown in the table below.

[Table] Next, add 500 parts of water and 35% hydrochloric acid to 3210 parts of the organic solvent layer.
After adding 46 parts and stirring at 25°C for 1 hour, the liquid was separated by standing to obtain the results shown in the table below.

[Table] The total amount of this water layer and the first oil layer was 1156 parts, the content of benzyltriethylammonium chloride was 29.8%, and the purification yield was 99.3%. When a stock solution containing bromide or iodide corresponding to benzyltriethylammonium chloride was treated in the same manner, similar results were obtained. Example 10 Benzyltrimethylammonium chloride 386
parts, sodium sulfate 90 parts, sodium carbonate 16.5 parts
parts, sodium phosphate 45 parts, ammonium sulfate
To 2000 parts of the stock solution containing 13.2 parts, 1500 parts of a 45% potassium hydroxide aqueous solution was gradually added at 30°C with stirring, cooled to 5°C, and left to stand for 1 hour to separate the liquids to obtain the results shown in the table below.

[Table] Next, 2700 parts of n-octanol was added to the layer, and 25
After stirring at °C for 1 hour, the mixture was allowed to stand still for liquid separation, and the results shown in the table below were obtained.

[Table] Next, 500 parts of water and 51 parts of 35% hydrochloric acid were added to 2775 parts of the organic solvent layer, and back extraction was performed to obtain 1407 parts in total with the oil layer. The content of benzyltrimethyl-ammonium chloride is 27.3%, and the purification yield is
It was 99.5%. Similar results were obtained when a stock solution containing bromide or iodide instead of benzyltrimethylammonium chloride was subjected to the same treatment. Example 11 Lauryltrimethylammonium chloride 586
parts, sodium sulfate 95.5 parts, sodium carbonate 20.0 parts
parts, to 2220 parts of stock solution containing 18.8 parts of ammonium sulfate.
35 5800 parts milk of lime containing 28% calcium hydroxide
The mixture was gradually added at 5° C., cooled to 5° C., allowed to stand for 1 hour, and the liquid was separated to obtain the results shown in the table below.

[Table] 2-ethyl-1-hexanol was added to 6765 parts of the aqueous layer.
Add 6,700 parts of lauryltrimethylammonium compound to the organic solvent layer, then add 500 parts of water.
77 parts of 35% hydrochloric acid was added and back extracted to the aqueous layer. Lauryltrimethylammonium chloride 14.1
762 parts of an aqueous layer containing %. When combined with the previous oil layer, the purification yield was 98.6%. Example 12 Tetra-n-butylammonium bromide
580 parts, sodium sulfate 90 parts, potassium carbonate 20 parts
parts, sodium phosphate 10 parts, ammonium bromide 18 parts
2000 parts of stock solution containing 40% potassium hydroxide aqueous solution
1500 parts were added little by little at 30°C with stirring, cooled to 5°C, and allowed to stand for 1 hour to obtain the results shown in the table below.

[Table] A stock solution containing the corresponding hydrogen sulfate or perchlorate in place of tetra-n-butylammonium bromide was treated in the same manner. Obtained similar results. Example 13 To 1,500 parts of a stock solution containing 60 parts of N-butylpyridinium iodide, 96 parts of potassium sulfate, 22 parts of potassium carbonate, and 12.2 parts of ammonium sulfate, 2,000 parts of a 40% aqueous potassium hydroxide solution was added at 30°C, and after stirring well, The mixture was cooled to 5° C., allowed to stand for 1 hour, and separated into layers to obtain the following results.

[Table] Example 14 Stearyltrimethylammonium chloride
Add 469 parts of 96% sodium hydroxide flakes little by little to 2,000 parts of the stock solution containing 400 at 30°C while stirring well. After stirring for an additional 2 hours, cool to 10°C, leave to stand for 1 hour, and separate the liquids. Got the results.

[Table] Example 15 Distearyldimethylammonium chloride
To 2,200 parts of the stock solution containing 210 parts, 960 parts of a 45% aqueous sodium hydroxide solution was added at 30°C, stirred thoroughly, and then allowed to stand at 5°C for 1 hour to separate the liquids to obtain the results shown in the table below.

[Table] Example 16 Add 2000 parts of a 45% aqueous sodium hydroxide solution at 30°C to 1500 parts of a stock solution containing 60 parts of N-lauryl vicolinium chloride, stir well, and heat at 5°C.
The mixture was cooled to 100 mL, allowed to stand for 1 hour, and separated into liquids to obtain the results shown in the table below.

[Table] Example 17 Tetra-n-propylammonium bromide
To 1,980 parts of the stock solution containing 480 parts, 1,600 parts of a 45% aqueous sodium hydroxide solution was added at 30°C, stirred thoroughly, cooled to 5°C, and left to stand for 1 hour to obtain the results shown in the table below.

[Table] Example 18 Diethyldibenzylammonium chloride 358
1,500 parts of a 45% aqueous sodium hydroxide solution was added at 30° C. to 2,300 parts of the stock solution containing 1,500 parts, and after stirring well, the mixture was cooled to 5° C., left to stand for 1 hour, and the liquids were separated to obtain the results shown in the table below.

[Table] Example 19 Addition of 2250 parts of a stock solution containing 360 parts of P-methoxybenzyltriethylammonium chloride at 30°C.
After adding 1,550 parts of a 45% aqueous sodium hydroxide solution and stirring well, the mixture was cooled to 5°C, left to stand for 1 hour, and then separated to obtain the following results.

[Table] Example 20 Add 600 parts of potassium hydroxide to 2000 parts of a stock solution containing 550 parts of tetramethylammonium methyl sulfate at 60°C.
Add it little by little while stirring at 30°C.
The mixture was cooled to 100 mL, allowed to stand for 1 hour, and separated into layers to obtain the following results.

[Table] A stock solution containing tetraethylammonium ethyl sulfate instead of tetramethylammonium methyl sulfate was treated in the same manner. Similar results were obtained.

[Brief explanation of the drawing]

Figure 1 shows the mutual solubility of the benzyltriethylammonium chloride-sodium hydroxide-water system at 25°C. A: Water, B: Benzyltriethylammonium chloride, C: Sodium hydroxide.

Claims (1)

[Claims] 1. A layer consisting of a concentrated aqueous solution of a quaternary ammonium compound and an alkali are created by adding an alkali metal or alkaline earth metal hydroxide to a low concentration aqueous solution of a quaternary ammonium compound which may contain salts as impurities. Two layers and one layer consisting of an aqueous solution of metal or alkaline earth metal hydroxide;
A method for purifying and concentrating a quaternary ammonium compound, the method comprising: subsequent separation.