JPH05148276A - Continuos production of high-purity phosphoric acid ester salt - Google Patents

Abstract

PURPOSE:To obtain the subject compound in good efficiency by adding a small amount of lower alcohol to a specified liquid mixture and a solvent in an extractor for continuous extraction by counter-current contact with the solvent so as to demulsify the emulsion state. CONSTITUTION:When a mixed solution of a phosphoric acid ester salt [e.g. a salt containing a monoalkyl phosphoric acid ester of the formula (R is 8-36C alkyl or alkenyl) as a main component] and a nonionic compound (e.g. organic hydroxyl compound) is continuously brought into counter-current contact with 4-8C aliphatic hydrocarbon or 5-7C saturated alicyclic hydrocarbon (preferably n-pentane) using an extractor to extract the nonionic compound into the solvent and separate the nonionic compound, a 1-4C alcohol (preferably ethanol is added so that the lower alcohol concentration in the mixed solution may become an amount of 0.5-2 pts.wt. based on 1 pts.wt. water and 1-5wt.% based on 1 pts.wt. solvent) is fed from one or more places to carry out the extraction.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a high-purity phosphate ester salt.

[0002]

BACKGROUND OF THE INVENTION Phosphoric acid ester salts of organic hydroxy compounds are used in a wide range of fields such as detergents, rust preventives, emulsifiers, fiber treating agents, liquid ion exchangers and pharmaceuticals. Conventionally, as a method for producing a phosphoric acid ester, various methods, for example, a method using phosphorus oxychloride and an organic hydroxy compound, a method using phosphoric anhydride and water and an organic hydroxy compound (JP-B-57-61358),
Alternatively, a method using orthophosphoric acid or polyphosphoric acid and an organic hydroxy compound [JP-B-58-38435, d. K. Nelson (AKNelson) et al., In Organic Chemistry (Inorg.Chem.) 2 · 775 ( 1963) and JP-B-43
-26492 gazette] etc.

However, the phosphoric acid ester thus produced contains unreacted organic hydroxy compounds, impurities in the organic hydroxy compounds, coloring components, and non-ions such as by-products produced during phosphorylation. Compounds are present as impurities. For example, in the method (1), alkyl chloride is present as a by-product, and in the method (2), unreacted organic hydroxy compounds and phosphoric acid ester decomposition products are present. In addition to these nonionic compounds, a large number of orthophosphoric acids are present in the phosphoric acid ester as a by-product in the method of 1. Although a method for extracting a ionic compound with a solvent has been proposed (Japanese Patent Laid-Open No. 61-17594), the nonionic compound cannot be removed even by this method.

By the way, such nonionic impurities in the phosphoric acid ester cause the phosphoric acid ester salt to have an offensive odor, to deteriorate the color tone, or to cause irritation.
Depending on the application of the phosphate salt, such problems significantly reduce the value of the product. In particular, when a phosphate ester salt is used as a raw material for cosmetics such as creams and hair styling agents, shampoos, facial cleansers, bath agents, and toothpaste that are used or contacted directly with the human body, such impurities are It becomes a serious defect of the product. Therefore, when the phosphate ester salt is used for the above-mentioned use, it is very important to remove impurities in the phosphate ester.

As a method for removing the nonionic impurities in the phosphoric acid ester, a method of recrystallization or extraction using a solvent can be considered. However, since a large amount of solvent is required for the phosphoric acid ester in the recrystallization, it is possible to remove the nonionic portion, but loss of the phosphoric acid ester in the solvent cannot be avoided. When the phosphate ester is a mixture of monoester and diester,
Alternatively, in the case of a phosphoric acid ester obtained by phosphorylation using an oxoalcohol having an alkyl chain length distribution as the organic hydroxy compound, the composition before and after purification changes. Furthermore, there is a problem that it cannot be applied to non-crystalline phosphates. Further, in the extraction, it is very difficult to separate and remove only the nonionic component when the phosphoric acid ester is in the acid form, and the phosphoric acid ester is converted into the salt form in the aqueous layer to remove the nonionic component from the organic matter. The method of extracting into layers has the property that the system is easily emulsified. On the other hand, there is a method of adding a lower alcohol to the system to demulsify it (JP-A-62-135481), but there is a problem that a large amount of lower alcohol is required for demulsifying and industrialization is difficult.
As a method for deodorizing organic phosphoric acid ester, there is a method of forming a thin liquid film of phosphoric acid ester and bringing it into contact with an inert gas (JP-A-57-35595). This method is liquid at 60 to 90 ° C. It applies only to certain phosphate esters and can remove only low boiling nonionic components.

[0006]

Therefore, the unreacted organic hydroxy compound contained in the unreacted organic ester contained in the phosphoric acid ester, impurities in the organic hydroxy compound, the coloring component, and further phosphorylation It has been desired to develop a method capable of industrially easily and economically removing a nonionic compound such as a produced by-product.

[0007]

Under the circumstances, as a result of intensive investigations by the present inventors, as a result of non-ionic use of a solvent composed of a specific hydrocarbon from a mixed solution containing a phosphate ester salt and a nonionic compound. The present invention has been completed by finding that the above problems can be solved by supplying a lower alcohol to the mixed solution and solvent when extracting and separating the organic compound. That is, the present invention relates to a mixed solution containing a phosphate ester salt and a nonionic compound, and a carbon number of 4
1 selected from the group consisting of linear or branched aliphatic hydrocarbons having 8 to 8 and saturated alicyclic hydrocarbons having 5 to 7 carbons.
When the nonionic compound is extracted and separated into the solvent (a) by continuously countercurrently contacting with the solvent (a) of one or more kinds using an extractor, a lower alcohol (b) having 1 to 4 carbon atoms To a mixed solution and the solvent (a) to be supplied to the extractor, and to a continuous process for producing a high-purity phosphate ester salt.

The production method of the present invention is particularly applicable to the general formula (I)

[0009]

[Chemical 1]

(Wherein R represents a linear or branched alkyl or alkenyl group having 8 to 36 carbon atoms), when used as a phosphate ester containing a monoalkyl phosphate ester as a main component, The effect is remarkable, but the general formula (I)
And a mixture of dialkyl phosphates. Since the compound represented by the general formula (I) has an excellent emulsifying ability, no satisfactory effect can be obtained except for the method of the present invention. Examples of the compound represented by the general formula (I) include monooctyl phosphoric acid, monodecyl phosphoric acid,
Monododecyl phosphoric acid, monooctadecyl phosphoric acid, monotetracosyl phosphoric acid, monooctacosyl phosphoric acid, monooctenyl phosphoric acid, monooctadecenyl phosphoric acid, monotetracocenyl phosphoric acid, mono-2-hexyldecyl phosphoric acid , Mono-2-octylundecylphosphoric acid, mono-2-tetradecyloctadecylphosphoric acid and the like. Examples of the basic compound that forms a salt with a phosphate ester include sodium hydroxide, potassium hydroxide, ammonia, monoethanolamine, diethanolamine, triethanolamine, monoisopropanolamine, diisopropanolamine, triisopropanolamine and the like. Of these, triethanolamine and potassium hydroxide are preferred. The amount of the basic compound used is 0.8 to 2.5 parts by mole, preferably 1 to 2 parts by weight, per 1 part by mole of the phosphoric acid ester.
The molar part.

Examples of the solvent (a) used in the present invention include a straight chain or branched chain aliphatic hydrocarbon having 4 to 8 carbon atoms or a saturated alicyclic hydrocarbon having 5 to 7 carbon atoms, such as butane and n. -Pentane, n-hexane, n-heptane, cyclopentane, cyclohexane and the like.
-Pentane, n-hexane are preferred. The amount of the solvent (a) used is 0.1 to 20 parts by weight with respect to 1 part by weight of the phosphoric acid ester. Examples of the nonionic compound in the present invention include organic hydroxy compounds, impurities (such as methyl esters) in organic hydroxy compounds, decomposition products of phosphoric acid esters (such as hydrocarbons), and coloring components. The mixed solution in the present invention is an aqueous solution containing a phosphoric acid ester salt and a nonionic compound, and the solvent (a) or the like may be present.

Examples of the lower alcohol (b) having 1 to 4 carbon atoms include methanol, ethanol, n-propanol, isopropanol, n-butanol and the like.
Of these, ethanol and isopropanol are preferable. The amount of the lower alcohol (b) used is 0.1 to 3 parts by weight, preferably 0.5 to 2 parts by weight, relative to 1 part by weight of water in the mixed solution, and the solvent (a) has a concentration of the lower alcohol (b). 0.5-10
%, Preferably 1 to 5% by weight. The reason for adding the lower alcohol (b) in the present invention is to promote the demulsification of the emulsion which is difficult to be separated between the mixture and the solvent (a) and to perform a stable extraction operation. If the lower alcohol (b) added to the mixed solution is 0.1 part by weight or less with respect to 1 part by weight of water and 0.5% by weight or less with respect to the solvent (a), the demulsifying effect is small. In addition, lower alcohol added to the mixture
The effect of demulsification does not change when (b) is 3 parts by weight or more with respect to 1 part by weight of water and 10% by weight or more with respect to the solvent (a),
It is not preferable because the extraction efficiency decreases and the load of the step of recovering the lower alcohol (b) increases. The concentration of water in the mixture is 0.2 per 1 part by weight of phosphate ester salt.
-10 parts by weight, preferably 0.4-3 parts by weight.

As the continuous countercurrent type extractor used in the present invention, a known device may be used. For example, a countercurrent mixer-settler extractor, a countercurrent differential type extraction tower, a non-stirring stage type extraction tower. , A stirring type stage extraction tower, a centrifugal type extractor and the like, and among them, a non-stirring type stage type extraction tower and a centrifugal type extractor are preferable. More specifically, the present invention provides a mixed solution of a phosphate ester salt and a nonionic compound to which a lower alcohol (b) is added, and a solvent (a) to which a lower alcohol (b) is added. It is carried out by bringing them into contact with each other in an extractor and separating the nonionic compound into an oil layer (light liquid layer) which is the solvent (a). When extracting, even if the aqueous layer (heavy liquid layer) containing the phosphate ester salt is a droplet (dispersed phase) and the oil layer (light liquid layer) of the solvent (a) is a continuous phase, the solvent (a) Oil layer (light liquid layer)
May be the dispersed phase, and the aqueous layer (heavy liquid layer) containing the phosphate ester salt may be the continuous phase. When lower alcohol (b) is supplied to the liquid in the extractor, even if it is the oil layer (light liquid layer) of solvent (a), it is not the water layer (heavy liquid layer) containing the phosphate ester salt. Is also good. It is preferable to add the solvent (a) to the oil layer (light liquid layer). The temperature during the above extraction operation may be warmed. The 12-stage non-stirring stage extraction column used in the present invention is shown in FIG. As an example, a mixed solution containing a phosphoric acid ester salt and a nonionic compound and ethanol are supplied from the tower top 1, a mixed solvent of n-hexane containing ethanol is supplied from the tower bottom 2, and ethanol is further supplied from the tower wall 5. To supply. Extraction separation is performed by contacting the mixed liquid with n-hexane, the oil layer (n-hexane layer) is removed from the uppermost part 3 of the extraction column, and the extract liquid (aqueous layer) is obtained from the lowermost part 4. still,
The height 6 from the bottom 2 to the top 1 of the extraction tower is 4800 mm, and the diameter 7 of the extraction tower is 850 mm.

[0014]

According to the present invention, a large amount of lower alcohol was required in the conventional demulsification, but it becomes possible to demulsify with a small amount of lower alcohol, and the demulsification is fast, so that the apparatus can be made compact. Further, the amount of solvent used as an extractant can be significantly reduced, and the extraction efficiency can be improved. The present invention is effective especially when the mixed liquid is in an emulsified state containing the solvent (a), and the extraction efficiency can be improved.

[0015]

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited to these examples.
In the examples and comparative examples, all% of the composition is% by weight. Example 1 12-stage non-stirring stage extraction tower (perforated plate extraction tower) shown in FIG.
1741 Kg / hr (monododecyl phosphate 460 K / hr)
g, 25 kg of didodecyl phosphate / hour, 687 kg of water / hour, 6 kg / hour of unreacted dodecyl alcohol as a nonionic compound
Triethanolamine (563 kg / h) and ethanol 6 h / h
A continuous mixture of 55 kg was supplied from the top of the tower, and n-hexane with an ethanol concentration of 5% by weight was fed from the bottom of the tower at an hourly rate of 2500
It was supplied at Kg, and the mixture was subjected to extraction at 45 ° C with the dispersed phase and n-hexane as the continuous phase. As a result, an aqueous layer containing monoethanolamine tridodecylphosphate and free of dodecyl alcohol was obtained at 2600 kg per hour. Analyzing this, monododecyl phosphate 17.7%, didodecyl phosphate 0.96%, ethanol 28.1%, water 26.4%, dodecyl alcohol 0.04%, triethanolamine 21.6%,
The amount of n-hexane was 5.2%. The recovery rate of monododecyl phosphate is 99.8%, and the removal rate of dodecyl alcohol is
It was 83.3%.

Monododecyl phosphate, didodecyl phosphate,
For the analysis of triethanolamine, the sample was extracted with ethyl ether and a 0.1 N hydrochloric acid aqueous solution to extract and separate the phosphoric acid ester into an ethyl ether layer and triethanolamine into a 0.1 N hydrochloric acid aqueous solution layer, The content of monoalkylphosphoric acid, dialkylphosphoric acid and triethanolamine can be determined by titrating each with an alkali such as potassium hydroxide using an automatic potentiometric titrator. That is, in the ethyl ether layer, after the ethyl ether was topped (evaporated), the sample was subjected to potentiometric titration with potassium hydroxide in an aqueous ethanol solution to obtain a monoalkylphosphoric acid from the first equivalent point and the second equivalent point. And the content of dialkyl phosphoric acid are obtained, and the triethanolamine content is obtained from the difference between the first and second equivalent points by potentiometrically titrating 0.1N hydrochloric acid aqueous solution with potassium hydroxide. is there. The analysis of n-hexane and isopropanol was carried out by gas chromatography analysis of the sample, and the analysis of water was carried out by the Karl Fischer method. For analysis of non-ionic compounds,
The nonionic compound was extracted and separated into a petroleum ether layer by extracting the sample with petroleum ether and water, and the content was determined by topping the petroleum ether. The analysis in the following examples is also performed by this analysis method. 20 parts by weight of water was added to 100 parts by weight of the obtained aqueous layer and heated to azeotropically distill off ethanol and n-hexane together with water to obtain an aqueous triethanolamine monododecylphosphate solution.

Example 2 12-stage non-stirring stage type extraction column (perforated plate extraction column) shown in FIG.
Mixed solution (emulsified state) 3602 Kg / hr (monododecyl phosphate 611 Kg / h, didodecyl phosphate 38 Kg / h, water 848 K / h
g, n-hexane 1371 kg / hr, unreacted dodecyl alcohol as nonionic compound 20 kg / hr, triethanolamine 714 kg / hr), and ethanol continuously mixed at 886 kg / hr were fed from the top of the column and the ethanol concentration from the bottom of the column was adjusted. 2 wt% of n-hexane was supplied at 2530 kg per hour, and ethanol was added to the continuous phase at 80 kg per hour at the fourth stage from the top of the extraction column. In this case, extraction was carried out at 45 ° C. using the mixed liquid as a dispersed phase and n-hexane as a continuous phase. As a result, 3311 Kg / h of an aqueous layer containing monoethanolamine tridodecylphosphate and free of dodecyl alcohol was obtained. Analysis of this product shows that monododecyl phosphate is 18.4%, didodecyl phosphate is 1.2%, ethanol is 27.5%, water is 25.5%, dodecyl alcohol is 0.1%, and triethanolamine is 21.4%.
%, N-hexane was 5.9%. The recovery rate of monododecyl phosphate was 99.5% and the removal rate of dodecyl alcohol was 85.0%. 20 parts by weight of water was added to 100 parts by weight of the obtained aqueous layer and heated to azeotropically distill off ethanol and n-hexane together with water to obtain an aqueous triethanolamine monododecylphosphate solution.

Comparative Example 1 12-stage non-stirring stage extraction column (perforated plate extraction column) shown in FIG.
3615Kg / hour (631Kg / monododecylphosphoric acid / 37Kg / didodecylphosphoric acid / 850K / h water)
g, n-hexane 1357 kg / hr, unreacted dodecyl alcohol as nonionic compound 20 kg / hr, triethanolamine 720 kg / hr), and continuous mixture of 1109 kg ethanol / hour were fed from the top of the column, and n− from the bottom of the column. Hexane was supplied at 2500 kg / h, and the mixture was subjected to extraction at 45 ° C with the dispersed phase and n-hexane as the continuous phase. As a result, 3349.5 kg / h of an aqueous layer containing monododecylphosphoric acid triethanolamine salt and extracted with dodecyl alcohol was obtained. Analysis of this product shows that monododecyl phosphate is 18.7%, didodecyl phosphate is 1.1%, ethanol is 27.4%, and water is 25.3%.
%, Dodecyl alcohol was 0.3%, triethanolamine was 21.5%, and n-hexane was 5.7%. The recovery rate of monododecyl phosphate was 99.5% and the removal rate of dodecyl alcohol was 57.5%. 20 parts by weight of water was added to 100 parts by weight of the obtained aqueous layer and heated to azeotropically distill off ethanol and n-hexane together with water to obtain an aqueous triethanolamine monododecylphosphate solution.

Example 3 A phosphoric acid monoester was obtained using a synthetic oxoalcohol having 11 to 15 carbon atoms (manufactured by Mitsubishi Kasei Co., Ltd., trade name: Dayadol 115L). Centrifugal extractor with rotor diameter 90 cm [Hitachi, Ltd., device name Ultrex] mixed solution containing the above monoester phosphate (emulsified state) every hour
2325Kg (520Kg / h of phosphoric acid monoester, 1048K / h of water)
g, n-hexane 607 kg / hr, synthetic oxo alcohol 16 kg / hr, potassium hydroxide 134 kg / hr) and ethanol 728 kg / hr were continuously mixed and fed to the heavy liquid inlet of the centrifugal extractor, and the concentration of ethanol was 2 from the light liquid inlet. Extraction was performed by supplying 1973 kg of n-hexane at a weight percentage of 1973 kg / h. as a result,
2553 Kg / h of an aqueous layer containing the potassium salt of phosphoric acid monoester and free of synthetic oxo alcohol was obtained. Analysis of this product shows that phosphoric acid monoester is 20.3%, ethanol is 29.0%, water is 40.7%, and synthetic oxo alcohol is
0.1%, potassium hydroxide 5.1%, n-hexane 4.8
%Met. The recovery rate of phosphoric acid monoester was 99.8%, and the removal rate of synthetic oxo alcohol was 87.5%.
20 parts by weight of water was added to 100 parts by weight of the obtained aqueous layer, and the mixture was heated to azeotropically distill off ethanol and n-hexane together with water to obtain an aqueous potassium salt solution of phosphoric acid monoester.

Test Example 1 Table 1 shows the quality evaluation results of the phosphoric acid monoesters obtained in Examples 1 to 3 and Comparative Example 1. The color tone was measured by measuring the light transmittance of a 10% ethanol solution at a wavelength of 420 nm.
It is expressed as log T) × 1000, and the smaller the value, the better. The odor was evaluated by a sensory test.

[0021]

[Table 1]

From Table 1, it can be seen that according to the present invention, a high-purity phosphate ester salt having an improved removal rate of nonionic compounds and a good color tone and odor can be obtained.

[Brief description of drawings]

FIG. 1 is a schematic view of a non-stirring stage extraction column.

[Explanation of symbols] 1 tower top 2 tower bottom 3 uppermost 4 lowermost 5 wall

Claims (3)

[Claims] 1. A mixed solution containing a phosphate ester salt and a nonionic compound, a straight-chain or branched-chain aliphatic hydrocarbon having 4 to 8 carbon atoms and a saturated alicyclic hydrocarbon having 5 to 7 carbon atoms. When one or more solvents (a) selected from the group are continuously countercurrently contacted with each other using an extractor to extract and separate the nonionic compound into the solvent (a), the number of carbon atoms is 1 to 4 The lower alcohol (b) of the above, and the mixed solution and the solvent (a) which are supplied to the extractor.
The method for continuously producing a high-purity phosphoric acid ester salt, comprising: 2. The continuous process for producing a high-purity phosphate ester salt according to claim 1, wherein the lower alcohol (b) is further supplied to the liquid in the extractor from at least one location. 3. The continuous process for producing a high-purity phosphate ester salt according to claim 1 or 2, wherein the lower alcohol (b) is ethanol.