JPH0246040B2 - RINSANESUTERUNOSEISEIHO - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for purifying phosphoric acid esters. [Prior Art] Phosphate esters of organic hydroxy compounds are used in a wide range of fields such as detergents, textile treatment agents, emulsifiers, rust preventives, liquid ion exchangers, and pharmaceuticals. Conventionally, phosphoric acid esters have been produced using various methods, such as a method using phosphoric anhydride, water, and an organic hydroxy compound (Japanese Patent Publication No. 57-61358), or a method using orthophosphoric acid, polyphosphoric acid, or condensed phosphoric acid and an organic hydroxy compound. Method of reacting compounds [Special Publication No. 58-38435, AKNelson et al. Inorg.Chem,
2,775, (1963) and Special Publication No. 43-26492] are known. However, as with these production methods, unreacted orthophosphoric acid cannot be avoided in the phosphoric acid ester obtained by methods that use phosphoric anhydride, orthophosphoric acid, or condensed phosphoric acid as a phosphorylating agent. . However, mixing a large amount of orthophosphoric acid into the phosphoric acid ester may have an undesirable effect depending on the intended use. For example, when a monosodium neutralized product of monoalkyl phosphoric acid is used as a paste-like cleaning agent, if a large amount of orthophosphoric acid is present, disodium phosphate will precipitate, which is undesirable for use. Therefore, efficient separation of phosphoric acid ester and orthophosphoric acid is an important problem in the production of phosphoric acid ester. On the other hand, as a conventional method for removing orthophosphoric acid from a mixture of phosphoric acid ester and orthophosphoric acid, the method of Nelson et al. [Inorg.Chem, 2 ,
775 (1963)] is known. However, ethyl ether is a low boiling point solvent and has an extremely low flash point, and since peroxide is gradually generated, there is a risk of explosion if it accumulates, and it also has an unfavorable effect on the human body, so it is not suitable for industrial use. There is a problem with that. Under these circumstances, the inventor of the present invention has intensively investigated various solvents other than ethyl ether in order to overcome these drawbacks, but it has been found that orthophosphoric acid can be removed with ether solvents such as diisopropyl ether in the same way as with ethyl ether. However, this was not the preferred method due to the risk of explosion due to the accumulation of peroxide. In addition, in other solvents, phosphoric esters, especially monoalkyl phosphoric esters themselves, are very good emulsifiers, so the entire system becomes a stable emulsifying system, and favorable results could not be obtained with a single solvent system. . [Problems to be solved by the invention] Under these circumstances, the present inventors conducted research and found that (a) linear or branched saturated hydrocarbons having 4 to 8 carbon atoms or saturated carbon water with 5 to 7 carbon atoms; If extraction and separation is performed by combining an alicyclic hydrocarbon and (b) a solvent of a lower alcohol having 1 to 4 carbon atoms and water, (a) monoalkyl phosphoric acid is added to the oil layer which is the solvent, and (b) the solvent is They discovered that orthophosphoric acid could be efficiently separated from the aqueous layer, and filed a patent application earlier. However, if the hydrocarbon layer extracted and separated in this way is recrystallized or topped as it is, problems arise due to water and lower alcohols mixed in. For example, in the case of recrystallization, the presence of water in the phosphate ester layer deteriorates its crystallinity, and therefore the crystallization temperature needs to be lower. Furthermore, the presence of a lower alcohol increases the solubility of the phosphoric ester in the saturated aliphatic hydrocarbon or saturated alicyclic hydrocarbon used, resulting in a decrease in the recovery rate of the phosphoric ester due to crystal precipitation. In addition, when topping is performed, when the solvent component is distilled off under reduced pressure from the phosphate ester layer, saturated aliphatic hydrocarbons or saturated alicyclic hydrocarbons can be easily distilled off, but water and lower alcohols in the phosphate ester are It is relatively difficult to distill off, and even if it is distilled off by heating, the phosphoric acid ester itself
This was also difficult because it decomposed at 100°C. [Means for Solving the Problems] Therefore, the inventor conducted further research and completed the present invention. That is, the present invention provides a mixture containing a phosphoric acid ester represented by the following general formula () and orthophosphoric acid, and (a) a linear or branched saturated aliphatic hydrocarbon having 4 to 8 carbon atoms and a Carbon number 5
One or more selected from the group consisting of ~7 saturated alicyclic hydrocarbons, (b) a lower alcohol having 1 to 4 carbon atoms, and water are added, and the phosphoric acid ester is extracted and separated into a hydrocarbon layer, and then the copolymer is added. After removing the lower alcohol and water mixed into the hydrocarbon layer by boiling distillation,
The present invention provides a method for purifying phosphoric acid ester, which is characterized by recrystallization or topping. (In the formula, R represents a straight-chain or branched alkyl or alkenyl group having 8 to 36 carbon atoms.) Since the compound represented by the general formula () has excellent emulsifying ability, it is not satisfactory for methods other than the present invention. I can't get the results I want. Examples of the compound represented by the general formula () include monooctyl phosphoric acid, monodecyl phosphoric acid, monooctadecyl phosphoric acid, monotetracosyl phosphoric acid, monooctacosyl phosphoric acid, monooctenyl phosphoric acid, monooctadecenyl phosphoric acid, Examples include mono-tetracosenyl phosphoric acid, mono-2-hexyldecyl phosphoric acid, mono-2-octyl undecyl phosphoric acid, and mono-2-tetradecyl octadecyl phosphoric acid. Examples of (a) linear or branched aliphatic hydrocarbons having 4 to 8 carbon atoms or saturated alicyclic hydrocarbons having 5 to 7 carbon atoms, which are one of the solvents used in the present invention, include butane, n- Pentane, n-hexane, n-
Examples include heptane, cyclopentane, and cyclohexane, with n-pentane and n-hexane being preferred. The amount of solvent (a) to be used is appropriately determined depending on the type of phosphoric ester, etc., but is usually 0.5 to 10 parts by weight per 1 part by weight of phosphoric ester. The lower alcohol used for the other solvent (b) lower alcohol with 1 to 4 carbon atoms - water includes, for example, methanol, ethanol, n-propanol, isopropanol, n-butanol, etc. Among them, ethanol, Isopropanol is particularly preferred. The ratio of lower alcohol to water is determined depending on the type of lower alcohol, etc., but is 0.1 to 5 parts by weight, preferably 0.3 to 1 part by weight, per 1 part by weight of water. The amount of lower alcohol-water solvent (b) to be used can be determined appropriately based on the above ratio, etc., but usually 1 part orthophosphoric acid is used.
It is 0.5 to 80 parts by weight. By using the solvents (a) and (b) according to the present invention, (a) phosphoric acid ester is present in the oil layer (light liquid layer) which is the solvent, and orthophosphoric acid is present in the water layer (heavy liquid layer) which is the solvent. Acids can be separated efficiently. More specifically, the present invention includes 0.5 to 10 parts by weight of an aliphatic hydrocarbon or alicyclic hydrocarbon per 1 part by weight of water in a mixture of a phosphoric acid ester and orthophosphoric acid;
Preferably 1 to 3 parts by weight and 0.1 parts by weight of lower alcohol
This is carried out by adding up to 5 parts by weight, preferably 0.3 to 1 part by weight, stirring, and then allowing the mixture to stand for a while, and then separating the oil and water layers. Furthermore, if necessary, after separating and removing the aqueous layer, there is no problem in repeating the above operation by further adding a lower alcohol-aqueous solution. Furthermore, the temperature during this operation may be increased. After separating and removing the aqueous layer containing a large amount of orthophosphoric acid in this way, the oil layer containing a large amount of phosphoric acid ester may be left as is, or this oil layer may be further supplemented with saturated aliphatic hydrocarbons or saturated alicyclic hydrocarbons used during extraction and separation. Add 10 to 30 parts by weight, preferably 10 to 15 parts by weight, of the same solvent as the hydrocarbon to the water used for extraction, batchwise or continuously, and heat to above the boiling point of the solvent to extract water and By azeotropically removing lower alcohols, water and lower alcohols in the oil layer can be efficiently removed. Next, by topping the remaining saturated aliphatic hydrocarbons or alicyclic hydrocarbons from the residue thus obtained, a phosphoric acid ester containing almost no orthophosphoric acid can be obtained. For crystalline phosphate esters, add a certain amount of (a) solvent, which is the same or different from that used during extraction and separation, to the above residue, preferably 1
A phosphoric ester of even higher purity can be obtained by adding 1 to 20 parts by weight of the phosphoric acid ester, cooling the mixture, and performing recrystallization to precipitate phosphoric ester crystals. [Effects of the Invention] As described above, according to the present invention, orthophosphoric acid can be removed from a mixture of phosphoric acid ester and orthophosphoric acid with an extremely simple operation, so if this purification method is used, long chain alcohol and polyphosphoric acid can be removed. High purity phosphoric acid ester can be obtained in high yield from acid. Moreover, the orthophosphoric acid thus recovered has the advantage that it can be reused by concentration through dehydration. [Example] Next, an example and a comparative example will be given and explained. Example 1 A mixture consisting of 250 parts by weight of monododecyl phosphoric acid, 7 parts by weight of didodecyl phosphoric acid, and 400 parts by weight of orthophosphoric acid was placed in an extraction container, and 370 parts by weight of n-hexane was added.
parts by weight, 70 parts by weight of isopropanol and 190 parts by weight of water, and stirred at 50°C for 30 minutes. After that, stirring was stopped and the mixture was allowed to stand at 50°C for 30 minutes, and then the separated lower layer was extracted and removed. Add 190 parts by weight of water and 70 parts by weight of isopropanol to the remaining upper layer and stir again for 30 minutes.
After stirring at 50° C., the mixture was allowed to stand for 30 minutes, and the separated lower layer was extracted to obtain 828 parts by weight of an upper layer (normal hexane layer) containing monododecyl phosphoric acid and from which orthophosphoric acid was removed. Analysis of this product reveals that it contains 247 parts by weight (30%) of monododecyl phosphoric acid, 6.5 parts by weight (0.8%) of didodecyl phosphoric acid, 17 parts by weight (2%) of orthophosphoric acid, and 102 parts by weight (12 parts) of isopropanol.
%) and contained 85 parts by weight (10%) of water. (Recovery rate of monododecyl phosphoric acid: 99%, removal rate of orthophosphoric acid: 96%) For the analysis of monododecyl phosphoric acid and didodecyl phosphoric acid, phosphoric acid was extracted by extracting the sample with ethyl ether and a 0.1N aqueous solution of hydrochloric acid. Add the acid ester to the ethyl ether layer and orthophosphoric acid to the ethyl ether layer.
The contents of monoalkyl phosphoric acid, dialkyl phosphoric acid, and orthophosphoric acid are determined by extracting and separating the 0.1N hydrochloric acid aqueous solution layer and titrating each layer with an alkali such as potassium hydroxide using an automatic potentiometric titrator. That is, in the ethyl ether layer, after topping with ethyl ether, the sample is titrated potentiometrically with potassium hydroxide in an ethanol aqueous solution, and the monoalkyl phosphoric acid and dialkyl phosphoric acid are determined from the first equivalence point and the second equivalence point. The content of orthophosphoric acid can be determined from the difference between the first and second equivalence points by subjecting a 0.1N hydrochloric acid aqueous solution to potentiometric titration with potassium hydroxide. Isopropanol was analyzed by gas chromatography of the sample, and water was analyzed by the Karl-Fitschier method. In addition, the analyzes in the following Examples and Comparative Examples were also analyzed using this analytical method. 3020 parts by weight of n-hexane was continuously added to the remaining upper layer, heated to azeotropically distill off water and isopropanol together with n-hexane, and finally 70 parts by weight of n-hexane was added.
Heated to ℃. At this point, isopropanol,
Analysis of water and water revealed that neither was present.
Isopropanol and water were successfully removed. 180 parts by weight of n-hexane was added to the remaining mixture (liquid content at this time was 67%), and the solution was heated at 5°C.
The precipitated crystals were collected by filtration and dried at 30°C for 5 hours at a reduced pressure of 20 mmHg. The obtained crystals were 242 parts by weight, and analysis of these crystals revealed that monododecyl phosphoric acid was 235 parts by weight and orthophosphoric acid was 7 parts by weight.
Parts by weight were included. Furthermore, it did not contain water or isopropanol, and there were no problems such as the odor of isopropanol. The analysis values at each stage are summarized as follows. 1 Recovery rate of monododecyl phosphoric acid in the separated upper layer 99% 2 Removal rate of orthophosphoric acid 96% 3 Content of monododecyl phosphoric acid in the upper layer after extraction and separation 30% 4 Content of phosphoric acid in the upper layer after extraction and separation 2% 5 Content of isopropanol in the upper layer after extractive separation 12% 6 Content of water in the upper layer after extractive separation 10% 7 Content of water after azeotropic removal 0% 8 Content of isopropanol after azeotropic removal 0% 9 Purification Content of monododecyl phosphoric acid after purification 97.1% 10 Content of didodecyl phosphoric acid after purification 0% 11 Content of orthophosphoric acid after purification 2.9% 12 Content of isopropanol after purification 0% 13 Content of water after purification 0% Examples 2. Put a mixture consisting of 990 parts by weight of monohexadecyl phosphoric acid and 620 parts by weight of orthophosphoric acid into an extraction container, add 2270 parts by weight of n-hexane, 560 parts by weight of isopropanol, and 750 parts by weight of water,
After stirring at 50°C for 30 minutes, the mixture was further allowed to stand at 50°C for 30 minutes. After confirming that the upper layer and lower layer were separated, the lower layer was extracted from the extraction container. Add isopropanol 150 to the remaining upper layer again.
Parts by weight and 750 parts by weight of water were added, stirred at 50°C for 30 minutes, left to stand for another 30 minutes, and the lower layer was taken out again to form an upper layer containing monohexadecyl phosphoric acid and from which orthophosphoric acid was removed (normal hexane layer) 3970 Parts by weight were obtained. 3,400 parts by weight of n-hexane was continuously added dropwise to this upper layer, heated, water and isopropanol remaining in the upper layer were azeotropically removed with n-hexane, and then finally heated to 80°C. At this point, isopropanol and water were analyzed and neither were found to be present. Further depressurize (20
mmHg) and dried at 50° C. for 5 hours to completely remove n-hexane, yielding 989 parts by weight of a white powder. Analysis of this powder revealed that it contained 970 parts by weight of monohexadecyl phosphoric acid and 18.6 parts by weight of orthophosphoric acid. Furthermore, it did not contain water or isopropanol, so there were no problems such as the odor of isopropanol. The analysis values at each stage are summarized as follows. 1 Recovery rate of monohexadecyl phosphoric acid in the separated upper layer 98% 2 Removal rate of orthophosphoric acid 97% 3 Content of monohexadecyl phosphoric acid in the upper layer after extraction and separation 24.4% 4 Phosphoric acid in the upper layer after extraction and separation Content of 0.5% 5 Content of isopropanol in the upper layer after extractive separation 10% 6 Content of water in the upper layer after extractive separation 8% 7 Content of water after azeotropic removal 0% 8 Content of isopropanol after azeotropic removal 0% 9 Content of monohexadecyl phosphate after purification
98% 10 Content of orthophosphoric acid after purification 1.9% 11 Content of isopropanol after purification 0% 12 Content of water after purification 0% Example 3 Mono-2-undecylhexadecyl phosphoric acid 490
A mixture consisting of 200 parts by weight of orthophosphoric acid and 30 parts by weight of di-2-undecylhexadecyl phosphoric acid was placed in an extraction container, and normal hexane was added thereto.
Add 820 parts by weight, 410 parts by weight of water, and 190 parts by weight of ethanol, stir while keeping warm at 50°C for 30 minutes, then
Leave to stand at 50℃. After confirming that the upper and lower layers were separated, the lower layer was removed. Add 190 parts by weight of ethanol and 410 parts by weight of water to the remaining upper layer once again, stir at 50°C for 30 minutes, and then leave to stand at 50°C. After confirming separation of the upper and lower layers, remove the lower layer. 1682 parts by weight of an upper layer (normal hexane layer) containing -2-undecylhexadecyl phosphoric acid and from which orthophosphoric acid was removed was obtained. Further, 3520 parts by weight of n-hexane is continuously added to the n-hexane solution containing the remaining phosphoric acid ester, heated, and the remaining water and ethanol are removed by azeotroping with the hexane, and finally was heated to 80°C. At this point, analysis of isopropanol and water revealed that neither was present. Further reduce the pressure (20mmHg) and heat to 50℃.
The mixture was dried for 5 hours to completely remove n-hexane and obtain 534 parts by weight of a white powder. Analysis of this powder revealed that it contained 475 parts by weight of mono-2-undecylhexadecyl phosphoric acid, 47 parts by weight of di-2-undecylhexadecyl phosphoric acid, and 12 parts by weight of orthophosphoric acid. Further, water and isopropanol were not included. The analysis values at each stage are summarized as follows. 1 Recovery rate of mono-2-undecylhexadecyl phosphoric acid in the separated upper layer 97% 2 Removal rate of orthophosphoric acid 94% 3 Content of mono-2-undecylhexadecyl phosphoric acid in the upper layer after extraction and separation 28.2 % 4 Content of phosphoric acid in the upper layer after extraction and separation 0.7% 5 Content of ethanol in the upper layer after extraction and separation
9.7% 6 Content of water in the upper layer after extraction separation 9.8% 7 Content of water after azeotropic removal 0% 8 Content of ethanol after azeotropic removal 0% 9 Mono-2-undecylhexadecyl phosphoric acid after purification Content of 89% 10 Content of di-2-undecylhexadecyl phosphate after purification 8.8% 11 Content of orthophosphoric acid after purification 2.2% 12 Content of ethanol after purification 0% 13 Content of water after purification 0% Comparative Example 1 Same as Example 1, 250 parts by weight of monodecyl phosphoric acid,
Example 1 A mixture consisting of 7 parts by weight of didodecyl phosphoric acid and 400 parts by weight of orthophosphoric acid was placed in an extraction container.
The same amounts of n-hexane, water, and isopropanol were added, and the same operation (extraction operation was performed twice) was performed to obtain 824 parts by weight of n-hexane layer containing monododecyl phosphoric acid. Analyzing this,
It contained 245 parts by weight of monododecyl phosphoric acid, 6 parts by weight of didodecyl phosphoric acid, 16 parts by weight of orthophosphoric acid, 100 parts by weight of isopropanol, and 87 parts by weight of water. This mixed solution was cooled to -5° C. to crystallize monododecyl phosphoric acid, and then separated. The crystal form at this time was a clear plate-like crystal form in Example 1, but it was sticky and did not exhibit a clear crystal form. In addition, this product was used in Example 1
After drying in the same manner as above, 175 parts by weight of white powder was obtained. Analysis of this powder revealed that it contained 135 parts by weight of monododecyl phosphoric acid, 4 parts by weight of didodecyl phosphoric acid, 12 parts by weight of orthophosphoric acid, 1 part by weight of isopropanol, and 5 parts by weight of water, and the odor of isopropanol could not be removed. . Furthermore, the recovery rate of mordodecyl phosphoric acid during recrystallization was 55%, whereas it was 95% in Example 1.
It was hot. Comparative Example 2 Same as Example 2, monohexadecyl phosphate 990
A mixture consisting of parts by weight and 620 parts by weight of orthophosphoric acid was placed in an extraction container, and the same operation as in Example 2 (extraction operation was performed twice) was performed to obtain 3974 parts by weight of a normal hexane layer containing monohexadecyl phosphoric acid. . When this substance was analyzed, monohexadecyl phosphate was found.
It contained 975 parts by weight, 17.5 parts by weight of orthophosphoric acid, 385 parts by weight of isopropanol, and 326 parts by weight of water. This product was heated as it was without adding n-hexane and topped, and then dried under reduced pressure in the same manner as in Example 2 to distill off the solvent component to obtain 1018 parts by weight of a white powder. Ta. Analysis of this product revealed that it contained 975 parts by weight of monohexadecyl phosphoric acid, 17.5 parts by weight of orthophosphoric acid, 5 parts by weight of isopropanol, and 20 parts by weight of water, and the odor of isopropanol could not be removed. Comparative example 3 130 parts by weight of monododecyl phosphoric acid, orthophosphoric acid
Normal hexane 180 to a mixture consisting of 190 parts by weight
parts by weight and 90 parts by weight of water were added and stirred for 30 minutes. After that, the mixture was allowed to stand still, and after confirming the separation of the layers, the mixture was separated into an upper layer and a lower layer. Analysis of this upper layer revealed that it contained 113 parts by weight of monododecyl phosphoric acid and 68.5 parts by weight of orthophosphoric acid. (Removal rate of orthophosphoric acid 64%, recovery rate of monododecyl phosphoric acid 87%).

Claims (1)

[Claims] First-order general formula () (In the formula, R represents a linear or branched alkyl or alkenyl group having 8 to 36 carbon atoms.) To a mixture containing a phosphoric acid ester represented by the formula and orthophosphoric acid, (a) having 4 to 36 carbon atoms is added as a solvent. (b) a lower alcohol having 1 to 4 carbon atoms and water; and (b) a lower alcohol having 1 to 4 carbon atoms and water. In addition, after extracting and separating the phosphoric ester into a hydrocarbon layer, the lower alcohol and water mixed in the hydrocarbon layer are removed by azeotropic distillation, and then the phosphoric ester is recrystallized or topped. Purification method.