JP3500288B2 - Method for producing phosphoric acid monoester - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a phosphoric acid monoester, which has a small content of phosphoric acid diester and phosphoric acid as impurities and is excellent in hue and odor.

[0002]

BACKGROUND OF THE INVENTION Phosphoric acid esters of organic hydroxy compounds are used in a wide range of fields as detergents, fiber treating agents, emulsifiers, preservatives, liquid ion exchangers, and raw materials for pharmaceuticals. However, there is a large difference in the physical properties between phosphoric acid monoester and phosphoric acid diester. For example, in the case of alkali metal salts and alkanol salts of long-chain alkyl phosphates, phosphoric acid monoesters are water-soluble, have good foaming power and detergency, and have low skin irritation, and are therefore excellent as a detergent component. On the other hand, phosphoric acid diester is sparingly soluble in water, has almost no foaming power, and rather exhibits foam suppressing property, and therefore cannot be applied as a component of a highly foaming detergent. Moreover, when phosphoric acid is contained in the phosphoric acid monoester as an impurity, it may have an unfavorable effect depending on the application.

As a method for producing phosphoric acid monoester,
A method is known in which an organic hydroxy compound and phosphoric acid are reacted to obtain a mixture of phosphoric acid monoester, phosphoric acid diester and phosphoric acid, and then phosphoric acid monoester is separated.

In Japanese Patent Laid-Open No. 60-258191, a mixture of phosphoric acid monoester and the like is extracted and separated in the presence of an alkali or an amine with a mixed liquid of liquid hydrocarbon and water (in some cases, alcohol). A method is disclosed. However, this technique has a problem in that the amount of waste liquid increases due to the necessity of repeating the extraction operation. JP-A-2-286690 discloses a method in which a mixture of a phosphoric acid monoester or the like is crystallized using a solvent, the phosphoric acid monoester is left in a mother liquor, and a phosphoric acid diester is generated as a precipitate, thereby separating the phosphoric acid monoester. It is disclosed. However, this technique
Phosphoric acid, unreacted alcohol and a coloring substance are obtained as a mother liquor, and in order to separate phosphoric acid monoester and the other, a separation operation such as re-dissolving in a solvent and recrystallizing is necessary. And the manufacturing cost also rises.

In order to solve the problems of the prior art, a mixture of phosphoric acid monoester and the like is neutralized with a basic compound to form a phosphoric acid ester salt, and then the phosphoric acid monoester salt is precipitated in an aqueous system. Has been proposed, and the phosphoric acid diester salt is allowed to remain in the mother liquor for separation (JP-A-6-128277).
According to this method, a high-purity phosphoric acid monoester having a good hue and odor can be obtained, but the filterability is poor due to the poor cake properties of the precipitate, and the separation operation is complicated. There is room for

[0006] Therefore, an object of the present invention is to provide a method for producing a phosphoric acid monoester capable of obtaining a highly pure target product having a good hue and odor by a simple method.

[0007]

Means for Solving the Problems As a result of repeated studies by the present inventors, it is possible to obtain the above-mentioned object by obtaining monoester phosphate as a precipitate and further treating it with a non-aqueous solvent to improve filterability. And completed the present invention.

That is, according to the present invention, a mixture containing phosphoric acid monoester, phosphoric acid diester and phosphoric acid is subjected to crystallization treatment using a hydrocarbon solvent to form phosphoric acid monoester as a precipitate, and other components are added. A method for producing a phosphoric acid monoester, which comprises separating the phosphoric acid monoester by allowing it to remain in the mother liquor.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION A mixture containing a phosphoric acid monoester, a phosphoric acid diester and phosphoric acid (hereinafter referred to as a “phosphoric acid ester mixture”), which is a raw material in the production method of the present invention, includes a conventional organic hydroxy compound What was obtained by reaction with phosphoric acid can be used. Further, the phosphoric acid ester mixture may contain other compounds mixed in the usual production method such as an unreacted organic hydroxy compound and pyrophosphoric acid ester.

Examples of the phosphoric acid monoester or phosphoric acid diester contained in the phosphoric acid ester mixture include straight chain or branched chain saturated or unsaturated alcohols having 8 to 30 carbon atoms, and straight chain or 6 to 30 carbon atoms. Addition of 1 or more alkylene oxide having 2 to 4 carbon atoms to a saturated or unsaturated alcohol having a branched chain (additional mole number of 1 to 100), 1 to alkylenephenol (having 6 to 20 carbon atoms of alkylene moiety)
The above-mentioned alkylene oxide adduct having 2 to 4 carbon atoms (addition mole number 1 to 100), phosphorus pentoxide (phosphoric anhydride),
Examples thereof include esters with phosphoric acid such as polyphosphoric acid (condensed phosphoric acid) or orthophosphoric acid. Among them, a linear saturated or unsaturated alcohol having 8 to 30 carbon atoms or an adduct of one or more alkylene oxide having 2 to 4 carbon atoms with a linear saturated or unsaturated alcohol having 6 to 30 carbon atoms and phosphorus. An ester with an acid is preferable, and an ester of a saturated straight chain alcohol having 8 to 22 carbon atoms with phosphoric acid is particularly preferable.

In order to obtain a higher-purity phosphoric acid monoester, the phosphoric acid ester mixture has a phosphoric acid diester content of not more than 30% by weight of the total amount of the phosphoric acid monoester and the phosphoric acid diester, and Acid content is about 2
It is preferably 0% by weight or less. Further, in order to enhance the removal property of phosphoric acid, the water content in the phosphoric acid ester mixture is preferably 3% by weight or less, and particularly preferably 1% by weight or less.

As the hydrocarbon solvent used in the present invention,
Aliphatic hydrocarbons such as n-pentane, n-hexane, n-heptane, cyclohexane, benzene, toluene and xylene, cyclic saturated hydrocarbons or aromatic hydrocarbon solvents can be mentioned, and these are one kind or two kinds. The above can be used in combination. From the viewpoint of efficiently recovering the solvent, an aliphatic hydrocarbon solvent having 5 to 8 carbon atoms is preferable, and n-hexane is particularly preferable. The water content in the hydrocarbon solvent is preferably 0.5% by weight or less in order to enhance the ability to remove phosphoric acid in the phosphoric acid ester mixture. From the viewpoint of improving the purity of the obtained phosphoric acid monoester and the yield of the phosphoric acid monoester, the amount of the hydrocarbon solvent used is preferably 0.3 to 20 times by weight the amount of the phosphoric acid ester mixture. Yes, particularly preferably 1 to 1
It is 0 weight times.

Next, the production method of the present invention will be described with reference to an example of crystallization treatment using a phosphoric acid ester mixture and a hydrocarbon solvent.

First, the phosphoric acid ester mixture is heated and dissolved in a hydrocarbon solvent. The melting temperature at this time depends on the composition of the phosphoric acid ester mixture, the type and amount of the hydrocarbon solvent, but is 100 ° C. or lower in order to prevent the phosphoric acid ester from decomposing or coloring. Is preferred.

Next, the solution of the phosphoric acid ester mixture is cooled to form phosphoric acid monoester as a precipitate, and phosphoric acid diester, phosphoric acid and other impurities are left in the mother liquor. By this operation, the unreacted organic hydroxy compound and the coloring substance are contained in the mother liquor. The temperature during crystallization varies depending on the composition of the phosphoric acid ester mixture, the type and amount of the hydrocarbon solvent, but in order to increase the purity and yield of the phosphoric acid monoester, the precipitation temperature is increased from the supersaturation temperature 5 ° C higher than the precipitation temperature. It is preferable to carry out the heating at a temperature lower than the temperature by 15 ° C. The cooling rate until reaching the temperature range is not particularly limited. This crystallization treatment can be repeated twice or more using the same or different hydrocarbon solvent.

The solid-liquid separation method of the precipitate obtained by such crystallization and the mother liquor is not particularly limited, but since the precipitate obtained by the production method of the present invention has good filterability,
Solid-liquid separation can be easily performed by a centrifugal separation method, a pressure filtration method, a vacuum filtration method, or the like.

According to the production method of the present invention, the content of the phosphoric acid diester is preferably 10% by weight or less, particularly preferably 7% by weight or less, and particularly preferably 7% by weight or less of the total amount of the phosphoric acid monoester and the phosphoric acid diester. It is possible to obtain a high quality phosphoric acid monoester having a content of 5% by weight or less, particularly preferably 2% by weight or less, based on the total amount of the phosphoric acid monoester and the phosphoric acid diester.

The phosphoric acid monoester obtained by the production method of the present invention can be converted into a phosphoric acid monoester salt by neutralizing the residual hydroxyl group with an alkali or an amine.

The phosphoric acid monoester obtained by the production method of the present invention is more colorless and has a hue of preferably 15 or less, and particularly preferably 10 or less, in order to broaden its application in various fields.

[0020]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited thereto.

Example 1 2424.5 g of cetyl alcohol (molecular weight 242.45) was charged into a 5 liter reaction vessel and heated to 70 ° C. under a nitrogen atmosphere to dissolve it. Next, 1 in terms of phosphoric acid
After adding 786.5 g of 17% polyphosphoric acid over 30 minutes, the temperature was raised to 90 ° C. and the reaction was carried out for 1 hour. Then, phosphorus pentoxide (phosphoric anhydride, effective content 98.5% by weight)
124.0 g was charged over 0.5 hour and reacted at 90 ° C. for 8 hours. The composition of the reaction product thus obtained was 79.0% by weight of monocetyl phosphate ester, 10.1% by weight of dicetyl phosphate ester, and 7.0% by weight of phosphoric acid.
And the unreacted alcohol was 3.9% by weight. As a result of measurement by NMR, pyrophosphate and water were not detected. The hue was 35 as a cullet, and the odor had an unreacted alcohol odor.

Next, 145.2 g of the reaction product was transferred to a 1-liter container for crystallization, 368.6 g of n-hexane was added, and the temperature was raised with stirring. As a result, it was completely melted at 56 ° C, and further heated to 60 ° C. After that, 0.5 ℃
When cooling was performed at a rate of / min, precipitation (precipitation) of phosphoric acid monoester was observed at 47.5 ° C, and the temperature was maintained at the same temperature for 30 minutes. The mixture was further cooled and maintained at 44 ° C. for 30 minutes, and then pressure filtered at the same temperature for about 15 minutes to separate the cake (precipitation) and the mother liquor. As a result, 156.8 g of cake was obtained. Then, this cake at 50 ℃, 2
It was dried at 0 mmHg for 12 hours to remove n-hexane.
5.9 g of phosphoric acid monoester was obtained. The composition of the phosphoric acid monoester thus obtained was measured by the following method to evaluate the hue and odor. The results are shown in Table 1.

(Measurement of Phosphoric Acid Content) About 5 g (a) of the phosphoric acid monoester obtained above was placed in a 500 ml separating funnel.
Gram), 100 ml of 0.1N hydrochloric acid and 100 ml of diethyl ether. Next, the separatory funnel was vigorously shaken and then left still to separate the contents into two phases. The lower layer (aqueous phase) was separated and potentiometrically titrated with a 0.5N aqueous potassium hydroxide solution, and the amount of alkali (b mol) consumed until the reaction reached the first equivalent point and the second equivalent of the reaction. The amount of alkali (cmol) consumed until the point was reached was determined. Using these numerical values, the phosphoric acid content (% by weight) in the dried cake was calculated from the following formula.

[0024]

[Equation 1]

(Measurement of Phosphoric Acid Monoester and Phosphoric Acid Diester Content) The organic phase of the above separating funnel was distilled,
Diethyl ether was distilled off. Tetrahydrofuran was added to the residue to make the total amount 100 ml. From there, 10 ml was taken with a whole pipette and added to and dissolved in a mixture of 55 ml of tetrahydrofuran and 35 ml of ion-exchanged water. The resulting solution was potentiometrically titrated with a 0.5N aqueous potassium hydroxide solution, and the amount of alkali (d mol) consumed until the reaction reached the first equivalent point and the amount of alkali consumed until the reaction reached the second equivalent point. The amount of alkali consumed (emol) was determined. Using these respective numerical values, the contents (% by weight) of phosphoric acid monoester and phosphoric acid diester in the dried cake were calculated from the following formula.

[0026]

[Equation 2]

(Measurement of Content of Unreacted Organic Hydroxy Compound) 5 to 10 g of the phosphoric acid monoester obtained above was dissolved in a mixture of 100 ml of isopropanol and 100 ml of a 15% by weight triethanolamine aqueous solution. The obtained solution was transferred to a 500 ml separating funnel and extracted three times with 100 ml of petroleum ether each time. The petroleum ether phases were combined and washed twice with 100 ml of 50% by volume aqueous ethanol and once with 100 ml of deionized water. Then, the petroleum ether phase was dried over anhydrous sodium sulfate, and then the petroleum ether was removed by evaporation. The residue was dried at room temperature under reduced pressure (about 200 mmHg) until a constant weight was reached, and the amount (% by weight) of petroleum ether extract (unreacted organic hydroxy compound) was determined.

(Evaluation of hue) Phosphoric acid monoester was diluted and dissolved in ethanol to 10 w / v%. The absorbance of the solution at 420 nm was measured and multiplied by 1000 to obtain a klet. The higher the kret number,
It shows that it is colored yellow, and the lower the value of Klett, the closer it is to colorless.

(Evaluation of Odor) Sensory evaluation was performed. It should be noted that "good" means that there is no irritating odor or unpleasant odor due to the heating history during the raw material or reaction and drying.

Example 2 The reaction product obtained in Example 1 (79.0% by weight of monocetyl phosphate ester, 10.1% by weight of dicetyl phosphate ester, 7.0% by weight of phosphoric acid and 3.9% by weight of unreacted alcohol). 102.0 g) was transferred to a 1 liter container for crystallization, 351.3 g of n-heptane was added, and the temperature was raised with stirring. As a result, it was completely melted at 58 ° C. and further heated to 63 ° C. Then, when cooling was performed at a rate of 0.5 ° C./minute, precipitation of phosphoric acid monoester was observed at 53.5 ° C., and the temperature was maintained at the same temperature for 30 minutes. The mixture was further cooled and maintained at 49 ° C. for 30 minutes, and then filtered at the same temperature as in Example 1. As a result, 107.4 g of cake was obtained. Then, this cake is heated at 60 ° C. for 5
Dried at mmHg for 12 hours to remove n-heptane, 68.
8 g of phosphoric acid monoester was obtained. The composition of the phosphoric acid monoester thus obtained was measured by the following method to evaluate the hue and odor. The results are shown in Table 1.

Example 3 121.5 g of the reaction product obtained in Example 1 was transferred to a 1-liter container for crystallization, 415.0 g of toluene was added, and the temperature was raised with stirring. As a result, it was completely melted at 52 ° C. and further heated to 58 ° C. After that, 0.5 ° C /
When cooling was performed at a rate of minutes, precipitation of phosphoric acid monoester was observed at 41 ° C., and the temperature was maintained at the same temperature for 30 minutes. The mixture was further cooled and maintained at 35 ° C for 30 minutes, and then filtered at the same temperature as in Example 1. As a result, 115.8 g of cake was obtained. Then this cake 70
Toluene is removed by drying at ℃, 5mmHg for 12 hours.
6.6 g of phosphoric acid monoester was obtained. The composition of the phosphoric acid monoester thus obtained was measured by the following method to evaluate the hue and odor. The results are shown in Table 1.

Example 4 In a 1-liter reaction vessel, myristyl alcohol (M
428.5 g of W214.41) was charged, and the temperature was raised to 62 ° C. under a nitrogen atmosphere to dissolve. Next, 85% phosphoric acid 6
After adding 7.0 g, the temperature was raised to 90 ° C., 122.7 g of phosphorus pentoxide (phosphoric anhydride, effective content 98.5% by weight) was charged over 0.6 hours, and the mixture was reacted at 90 ° C. for 8 hours. It was
Then, 30.7 g of ion-exchanged water was added to hydrolyze the pyrophosphate ester, and a hydrolysis reaction was carried out at 90 ° C. for 1 hour, followed by dehydration for 3 hours at 90 ° C. and 50 mmHg. The composition of the reaction product thus obtained is
It was 75.5% by weight of monomyristyl phosphate ester, 11.3% by weight of dimyristyl phosphate ester, 8.4% by weight of phosphoric acid and 3.7% by weight of unreacted alcohol. NM
As a result of measurement by R, pyrophosphate was not detected, and the water content was 1.1% by weight. Hue is Klett 2
It was 8, and the smell had an unreacted alcohol odor.

Next, 85.6 g of the reaction product was transferred to a 1 liter container for crystallization, and 430.1 g of n-hexane was added,
The temperature was raised with stirring. As a result, it was completely melted at 50 ° C, and further heated to 62 ° C. Then, when cooling was performed at a rate of 1 ° C./min, precipitation (precipitation) of phosphoric acid monoester was observed at 33 ° C., and the temperature was maintained for 30 minutes. Then, the temperature was raised to 35 ° C. and maintained for 30 minutes, followed by filtration at the same temperature as in Example 1. As a result, 77.0 g of cake was obtained. Then, this cake is heated at 50 ° C. for 20 minutes.
Dry for 12 hours at mmHg to remove n-hexane, 57.
9 g of phosphoric acid monoester was obtained. The composition of the phosphoric acid monoester thus obtained was measured by the following method to evaluate the hue and odor. The results are shown in Table 1.

Example 5 In a 1 liter reaction vessel, lauryl alcohol (MW
186.3) 254.1 g was charged, and 6
The temperature was raised to 5 ° C. and dissolved. Next, 75% phosphoric acid 21.
After adding 5 g, phosphorus pentoxide (phosphoric anhydride, effective ingredient 9
(8.5% by weight) 115.2 g was charged over 1 hour to obtain 9
After the temperature was raised to 0 ° C., the reaction was performed for 1 hour. Then, 118.5 g of lauryl alcohol was charged and reacted at 90 ° C. for 8 hours. The composition of the reaction product thus obtained was 70.1% by weight of monolauryl phosphate, 22.7% by weight of dilauryl phosphate, 3.5% by weight of phosphoric acid and 3.7% by weight of unreacted alcohol. there were. As a result of measurement by NMR, pyrophosphate and water were not detected.
The hue was 20 for Klett, and the odor had an unreacted alcohol odor.

Next, 152.4 g of the reaction product was transferred to a 1 liter container for crystallization, 451.2 g of n-hexane was added, and the temperature was raised with stirring. As a result, it was completely melted at 50 ° C. and further heated to 55 ° C. Then, when cooling was performed at a rate of 1 ° C./minute, precipitation (precipitation) of phosphoric acid monoester was observed at 20 ° C., and the temperature was maintained at the same temperature for 30 minutes. The mixture was further cooled, maintained at 16 ° C. for 30 minutes, and filtered at the same temperature as in Example 1. As a result, 123.5 g of cake was obtained. Then, this cake 45
N-Hexane was removed by drying at 20 ° C. and 20 mmHg for 12 hours to obtain 89.0 g of phosphoric acid monoester. The composition of the phosphoric acid monoester thus obtained was measured by the following method to evaluate the hue and odor. The results are shown in Table 1.

[0036]

[Table 1]

[0037]

[Equation 3]

[0038]

EFFECTS OF THE INVENTION According to the production method of the present invention, it is possible to easily obtain a high-quality phosphoric acid monoester having a high content of phosphoric acid monoester and a small content of phosphoric acid diester and phosphoric acid as impurities. You can Moreover, it is possible to provide a product of stable quality without deterioration of hue and odor. The phosphoric acid monoester obtained by the production method of the present invention is also suitable as a blending component of a highly foaming detergent.

Front page continuation (58) Fields surveyed (Int.Cl. ⁷ , DB name) C07F 9/09

Claims (5)

(57) [Claims] 1. A mixture containing phosphoric acid monoester, phosphoric acid diester and phosphoric acid is subjected to crystallization treatment using a hydrocarbon solvent to form phosphoric acid monoester as a precipitate, and other components remain in the mother liquor. A method for producing a phosphoric acid monoester, characterized in that the phosphoric acid monoester is separated. 2. The method for producing a phosphoric acid monoester according to claim 1, wherein the water content of the mixture containing phosphoric acid monoester, phosphoric acid diester and phosphoric acid is 3% by weight or less. 3. The method for producing a phosphoric acid monoester according to claim 1, wherein the hydrocarbon solvent is an aliphatic hydrocarbon solvent having 5 to 8 carbon atoms. 4. The amount of the hydrocarbon solvent used is 0.3 to 20 times by weight the amount of the mixture containing phosphoric acid monoester, phosphoric acid diester and phosphoric acid. 1. The method for producing a phosphoric acid monoester according to 1. 5. In the obtained phosphoric acid monoester, the content of phosphoric acid diester is 10% by weight or less of the total amount of phosphoric acid monoester and phosphoric acid diester,
The method for producing a phosphoric acid monoester according to any one of claims 1 to 4, wherein the content of phosphoric acid is 5% by weight or less based on the total amount of the phosphoric acid monoester and the phosphoric acid diester.