JPH08193089A - Production of phosphoric ester - Google Patents

Abstract

PURPOSE: To provide an industrial method for producing a high-quality phosphoric ester, good in foaming and excellent in stability. CONSTITUTION: A phosphorylating agent is reacted with an organic hydroxy compound and water is then added to the resultant reactional product. Thereby, pyrophosphate bonds present in the system are hydrolyzed so as to provide 0.05-5mol% content of the compounds having each pyrophosphate bond based on the total amount of the compounds containing phosphorus in this method for producing a phosphoric ester by reacting the one or more phosphorylating agents selected from the group consisting of phosphorus pentoxide, phosphoric acid and polyphosphoric acid with the organic hydroxy compound.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing a phosphoric acid ester. More specifically, the present invention relates to a method for producing a high-quality phosphoric acid ester having good foaming and excellent stability.

[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, rust preventives, liquid ion exchangers, pharmaceuticals and the like. . Conventionally, as a method for industrially producing a phosphoric acid ester, there is a method of reacting an organic hydroxy compound with phosphorus pentoxide. According to this method, the product is a monophosphoric acid represented by the following formula (A). It is an equimolar mixture of an ester and a phosphoric acid diester represented by the following formula (B) (hereinafter this mixture is referred to as sesquiphosphate).

[0003]

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(In the formula, R represents an organic hydroxy compound residue) However, phosphoric acid monoester and phosphoric acid diester have a large difference in physical properties. For example, alkali metal salts and alkanolamine salts of phosphoric acid monoesters of long-chain alkyl alcohols (for example, lauryl alcohol) are water-soluble, have good foaming power and detergency, have low toxicity and are less irritating to the skin. On the other hand, the alkali metal salt and alkanolamine salt of phosphoric acid diester are hardly dissolved in water, have almost no foaming power, and rather exhibit foam suppressing property. Therefore, the above sesquiphosphate containing a large amount of phosphoric acid diester cannot be used as a highly foaming detergent.

Therefore, there is a strong demand for industrially safe and easy production of a phosphoric acid ester having a high phosphoric acid monoester content, and several methods as described below have been reported. A method of hydrolyzing monophosphorodichloridate obtained by reacting an organic hydroxy compound with phosphorus oxychloride (K. SASSE edition; Methoden der Organischen C
hemie, Vol. 12/2, pages 163-164, and JP-A-50-642.
No. 26). A method in which 0.5 to 3 mol of water is added to an organic hydroxy compound in advance with respect to 1 mol of phosphorus pentoxide, and then phosphorus pentoxide is reacted (Japanese Patent Publication No. 41-14416). A method obtained by reacting an organic hydroxy compound with orthophosphoric acid and phosphorus pentoxide (Japanese Patent Publication No. 6730/42). Organic hydroxy compounds and condensed phosphoric acid (polyphosphoric acid)
(AKNelson et al., Inorg. Chem.,
2, 775 (1963), or FBClarke et al., J. Amer. Chem. So.
c., 88, 4401 (1966) and Japanese Examined Patent Publication No. 43-26492). Organic hydroxy compounds and condensed phosphoric acid (polyphosphoric acid)
After the reaction of the above, the excess phosphoric acid is recovered and concentrated and reused (JP-A-61-17594). The organic hydroxy compound is subjected to the phosphorylation reaction consisting of phosphorus pentoxide, phosphoric acid, and polyphosphoric acid with the phosphoric acid in the first step in an excessive phosphoric acid state, and then the organic hydroxy compound is adjusted to a stoichiometric amount. Is added to carry out the second step reaction (Japanese Examined Patent Publication No. 57-61358). A method obtained by performing a phosphorylation reaction while blowing water vapor when reacting an organic hydroxy compound with phosphorus pentoxide in the presence of water (Japanese Patent Publication No. 5-66958). Reacting polyphosphoric acid with an organic hydroxy compound,
Then, a method of adding phosphorus pentoxide so that the stoichiometric amount is obtained (Japanese Patent Application No. 6-224593). A method of reacting an organic hydroxy compound with a phosphorylating agent obtained by mixing phosphorus pentoxide with one or more selected from water, phosphoric acid and polyphosphoric acid (Japanese Patent Application No. 6-
No. 306364).

Among these methods, the methods of ,,, and have the following drawbacks. That is,
In order to obtain 1 mol of phosphoric acid monoester,
Since hydrogen chloride is generated in a molar amount, there is a problem in this treatment and working environment, and it is difficult to increase the yield of phosphoric acid monoester by producing an alkyl chloride by hydrogen chloride. In the method of and, if only looking at the ratio of the phosphoric acid monoester and the phosphoric acid diester, the proportion of the phosphoric acid monoester increases if the amount of water or orthophosphoric acid increases, but on the other hand, the reaction rate of phosphorus decreases, The production amount of orthophosphoric acid increases. The incorporation of this orthophosphoric acid into the product has an unfavorable effect depending on the intended use, which limits the field of use and reduces the product value of the product. For example, when a monosodium salt of a phosphoric acid monoester of a long-chain alkyl alcohol is used as a paste-like detergent, if a large amount of orthophosphoric acid is present, disodium phosphate precipitates, which is not preferable in use.

According to the method (1), a phosphoric acid monoester can be selectively obtained. However, the amount of orthophosphoric acid by-produced by the reaction is almost the same as the reciprocal of the average degree of condensation of polyphosphoric acid. Incorporation of acid is unavoidable, and the same problems as described above occur (in order to reduce the amount of inorganic orthophosphoric acid formed, polyphosphoric acid with a very high degree of condensation must be used, but polyphosphoric acid with a high degree of condensation is used. Is industrially difficult to manufacture due to the limitations of the material of the manufacturing pot etc.). In the method (1), the ratio of the phosphoric acid monoester and the phosphoric acid diester is increased by blowing steam, but the amount of orthophosphoric acid is increased, but the same problem as in the method (2) occurs.

Therefore, as an industrial manufacturing method,
The methods of and are preferred. However, in the phosphoric acid ester obtained by phosphorylating an organic hydroxy compound with one or more phosphorylating agents selected from the group consisting of phosphorus pentoxide, phosphoric acid and polyphosphoric acid, , For example, the following formula (C) having a pyrophosphate bond such as pyrophosphate or a pyrophosphate ester

[0009]

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When the compound represented by the formula (wherein X represents a hydrogen atom or an organic hydroxy compound residue) remains, and the obtained phosphate salt is used as a paste-like detergent However, it has a drawback that the obtained paste is hardened and its commercial value is lowered. Further, when the by-produced orthophosphoric acid is extracted and separated, if the extraction operation is carried out immediately after the reaction is completed, the layer separation speed becomes slow, and the layer separation property is deteriorated. As a solution to this problem, after the phosphorylation reaction, a method has been proposed in which water is added to the reaction product to hydrolyze it at 50 to 100 ° C. to completely decompose the pyrophosphate bond (Japanese Patent Publication No. 3-33160).
issue).

However, when a branched alcohol is used as the organic hydroxy compound and the branched alcohol is phosphorylated to produce a phosphoric acid ester, it is necessary to add water to the resultant product to completely hydrolyze it under considerably severe conditions. It must be made. Under such severe conditions, decomposition of the phosphoric acid ester itself occurs, and for example, Diadol 115L (trade name, C ₁₁ H ₂₃ OH: C ₁₃ H ₂₇ OH: C ₁₅ H manufactured by Mitsubishi Kasei Co., Ltd.) is used.
_{In the case of} a mixed alcohol of ₃₁ OH = 47:31:22 (weight ratio), a phosphoric acid ester using a branching ratio (weight% of branched alcohol in the total weight of alcohol, the same applies hereinafter) 50%, a reduction in foaming and storage. Poor stability and complete hydrolysis of the pyrophosphate bond leads to poor quality.

Therefore, the object of the present invention is to provide good foaming,
An object of the present invention is to provide an industrial process for producing a high-quality phosphate ester having excellent stability.

[0013]

Under these circumstances, the inventors of the present invention have earnestly studied the industrial production method of phosphoric acid ester, and as a result, after phosphorylating an organic hydroxy compound with a phosphorylating agent, the reaction It was found that by controlling the hydrolysis conditions so that the compound having a pyrophosphate bond remains in a constant ratio with respect to the product, a high-quality phosphate ester with good foaming and stability can be obtained. The present invention has been completed. That is, the present invention provides a method for producing a phosphoric acid ester by reacting one or more phosphorylating agents selected from the group consisting of phosphorus pentoxide, phosphoric acid and polyphosphoric acid with an organic hydroxy compound, Water was added to the reaction product obtained by reacting the phosphorylating agent with the organic hydroxy compound, and the content of the compound having a pyrophosphoric acid bond relative to the total amount of the phosphorus-containing compound was increased.
The present invention provides a method for producing a phosphoric acid ester, which comprises hydrolyzing a pyrophosphoric acid bond present in the system so as to be 0.05 to 5 mol%.

In the present invention, the compound having a pyrophosphate bond in the phosphoric acid ester can be identified by, for example, ³¹ P--N
Can be easily analyzed by MR (Oil Chemistry, Vol. 39, No. 4, 2
50-258, 1990), the ortho form and the pyro form can be discriminated from each other due to the difference in chemical shift, and can be quantitatively measured. The compounds having a pyrophosphate bond are the above-mentioned ~,
It is also present in the phosphoric acid ester obtained by the method of and and is also present in the phosphoric acid ester obtained by the method of depending on the production conditions, and these phosphoric acid ester is used as a paste-like detergent. If so, this hydrolysis operation becomes necessary. Further, when the reaction mixture obtained by the above method is subjected to solvent extraction to remove orthophosphoric acid, the presence of pyrophosphoric acid also deteriorates the partitioning property thereof, and this hydrolysis operation is Will be needed.

Conventionally, it has been considered that a conventional means is to select conditions under which the pyrophosphate bond is completely hydrolyzed by this hydrolysis operation. However, upon detailed examination, depending on the type of organic hydroxy compound. , Especially when a branched alcohol is used as the organic hydroxy compound,
Phosphorylation by the method of the above ~, when water is added to the reaction product to hydrolyze, if the conditions for completely decomposing the pyrophosphate bond are selected, the phosphoric acid ester itself is also decomposed,
It was found that the quality such as performance and stability deteriorates. That is, when a phosphoric acid ester is produced using a specific organic hydroxy compound, the hydrolysis condition is such that the content of the compound having a pyrophosphate bond is 0.05 to 5 mol% with respect to the total amount of the phosphorus-containing compound. It turns out that choosing the conditions is important. When the content of the compound having a pyrophosphate bond is less than 0.05 mol%, the foaming is deteriorated and the storage stability is deteriorated, and the quality of the phosphoric acid ester is deteriorated. When it exceeds 5 mol%, when the obtained phosphate ester salt is used as a paste-like cleaning agent, the paste obtained is hardened to reduce its commercial value or to remove orthophosphoric acid. Operability of solvent extraction deteriorates.

In the present invention, the hydrolysis operation is carried out by phosphorylating the organic hydroxy compound with the above-mentioned phosphorylating agent, and then adding water in an equimolar amount or more to the compound having a pyrophosphoric acid bond present in the system. It may be decomposed, but it is preferable to add an excess of water in order to rapidly perform the hydrolysis. For example, when phosphorylating an organic hydroxy compound using phosphorus pentoxide as the main phosphorylating agent (for example, the above method ,,,), 1 is added to the reaction product.
Hydrolysis is carried out by adding -15% by weight, preferably 3-10% by weight of water. When polyphosphoric acid is used as a phosphorylating agent to phosphorylate an organic hydroxy compound (for example, the method described above), when the unreacted excess phosphoric acid is made into an aqueous solution, the concentration of orthophosphoric acid is 80 to 95. It is preferable to add water so that the weight% thereof is obtained. The hydrolysis temperature in the present invention is preferably 60 to 100 ° C, and preferably 70 to 90 ° C in order to carry out the hydrolysis reaction quickly and avoid decomposition of the phosphate ester.

The phosphoric acid ester obtained by hydrolysis as described above may be used as it is, but it is preferable to add the following post-treatment depending on the intended use. That is, the phosphoric acid ester used for cosmetics is required to have a relatively good odor, but it is preferable to further deodorize the phosphoric acid ester performance product depending on the alkyl chain length. The deodorizing method may be any method such as steam distillation, extraction and crystallization. For example, the phosphoric acid ester obtained by the above method is hydrolyzed by adding water to the deodorant and further deodorized by steam distillation using a thin film. In that case, excess water added by hydrolysis is also removed together with the odor component. Also,
After adding water to the phosphoric acid ester obtained by the above method to hydrolyze, in order to remove excess phosphoric acid, lower alcohol and water are added and extraction is carried out. However, it is possible to remove phosphoric acid.

In the present invention, the organic hydroxy compound is a linear or branched saturated or unsaturated aliphatic alcohol having 6 to 30 carbon atoms, preferably 8 to 24 carbon atoms, or the aliphatic alcohol or alkylphenol (of an alkyl group). Examples thereof include alkylene oxides having 6 to 20 carbon atoms (2 to 4 carbon atoms) adducts (addition mole numbers 1 to 100), and the like. When a branched alcohol having a branching ratio of 10% by weight or more is used. Especially effective for.

Specific organic hydroxy compounds include:
For example, octanol, nonyl alcohol, decyl alcohol, undecyl alcohol, lauryl alcohol,
Examples include alcohols such as myristyl alcohol, pentadecyl alcohol, cetyl alcohol, stearyl alcohol, 2-ethylhexanol, isooctanol, isononanol, isodecanol, and isotridecanol. Further, as synthetic alcohol, oxochol (manufactured by Nissan Chemical Industries, Ltd.) Trade name), Dia Doll (trade name of Mitsubishi Kasei Co., Ltd.), Dobanol (trade name of Mitsubishi Yuka Co., Ltd.), Lineball (trade name of Showa Shell Chemical Co., Ltd.), Neodol (trade name of Shell) ), Rial (En
trade name) manufactured by i Chem., etc., and these organic hydroxy compounds may be used alone or in a mixture.

[0020]

Industrial Applicability According to the method of the present invention, it is possible to reduce the amount of compounds having a pyrophosphate bond, which exerts an undesired effect depending on the purpose of use, without deteriorating the quality of the phosphoric acid ester, resulting in good foaming and stability. Excellent and high quality phosphate ester can be produced.

[0021]

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

Example 1 23.5 g of 85% phosphoric acid [P ₂ O ₅ = 14.5 g in a 1000 ml reaction vessel]
(0.102 mol), water = 9.0 g (0.5 mol)] and phosphorus pentoxide (effective content 98.5 wt%) 33.3 g (0.234 mol) were added, and the temperature was 50 ° C.
It was stirred for 0.5 hour. Next is Neodol 1 (Shell product name, undecanol with a branching ratio of 16% by weight, Mw = 172.9) 1
After adding 72.9 g (1.00 mol), the mixture was reacted at 50 ° C. for 3 hours. 24.0 g of phosphorus pentoxide (effective content 98.5 wt%) was added to this reaction solution.
(0.167 mol) was gradually added at 50 ° C over 2 hours, and the mixture was further reacted at 90 ° C for 8 hours. In the reaction mixture at this time, the compound having a pyrophosphate bond was present in an amount of 13.0 mol% based on the total amount of the phosphorus-containing compound. Then, 5.0 g of ion-exchanged water was added to 100 g of this reaction mixture, and hydrolysis was carried out at 90 ° C. for 3 hours. The composition of the reaction product thus obtained, excluding water, was 75% by weight of monoundecylphosphate, 13.6% by weight of diundecylphosphate, 6.6% by weight of orthophosphoric acid, and 3.9% by weight of unreacted alcohol. It was Further, in this reaction mixture, the compound having a pyrophosphate bond is based on the total amount of the phosphorus-containing compound.
It was present at 0.10 mol%. Further, this reaction product was deodorized using a steam distillation apparatus with a forced thin film. The composition of the obtained residue excluding water was 78.8% by weight of monoundecylphosphoric acid, 14.1% by weight of diundecylphosphoric acid, and orthophosphoric acid.
It was 6.9% by weight and unreacted alcohol was 0.20% by weight. The compound having a pyrophosphate bond was present in an amount of 0.08 mol% based on the total amount of the phosphorus-containing compound.

The compositional analysis of the products was carried out. For phosphoric acid monoester, phosphoric acid diester and orthophosphoric acid, orthophosphoric acid was added to the aqueous layer by extraction with diethyl ether.
Phosphoric acid monoester and diester were separated in the ether layer, and each layer was determined by potentiometric titration. Also,
Unreacted alcohol was extracted by petroleum ether. Analysis of compounds with pyrophosphate bonds
^It was measured by ³¹ P-NMR.

Example 2 19.7 g of 75% phosphoric acid [P ₂ O ₅ = 10.7 g in a 1000 ml reaction vessel]
(0.075 mol), water = 9.0 g (0.5 mol)] and phosphorus pentoxide (effective content 98.5 wt%) 37.2 g (0.258 mol) were added, and the temperature was 60 ° C.
It was stirred for 0.5 hour. Next is Dia Doll 115L (trade name, manufactured by Mitsubishi Kasei Co., Ltd., C ₁₁ H ₂₃ OH: C ₁₃ H ₂₇ OH: C ₁₅ H ₃₁ OH
= Mixed alcohol of 47:31:22 (weight ratio), branching rate 50
%, Mw = 190.7) After adding 190.7 g (1.00 mol), 60 ° C
And reacted for 2 hours. Add phosphorus pentoxide (effective
98.5 wt%) 24.0 g (0.167 mol) was gradually added at 60 ° C. in 2 hours, and further reacted at 80 ° C. for 10 hours. In the reaction mixture at this time, the compound having a pyrophosphate bond was present in an amount of 14.0 mol% based on the total amount of the phosphorus-containing compound. Thereafter, 10.0 g of ion-exchanged water was added to 100 g of this reaction mixture, and hydrolysis was carried out at 90 ° C. for 3 hours. The composition of the reaction product thus obtained, calculated by removing water, was 76.0% by weight of monoalkylphosphoric acid, 13.8% by weight of dialkylphosphoric acid, 6.1% by weight of orthophosphoric acid and 4.1% by weight of unreacted alcohol. Further, in this reaction mixture, the compound having a pyrophosphate bond was present in an amount of 0.12 mol% based on the total amount of the phosphorus-containing compound. Further, this reaction product was deodorized using a steam distillation apparatus with a forced thin film. The composition of the obtained residue excluding water was 79.1% by weight of monoalkylphosphoric acid, 14.4% by weight of dialkylphosphoric acid, 6.3% by weight of orthophosphoric acid, and 0.25% by weight of unreacted alcohol. The compound having a pyrophosphate bond was present in an amount of 0.10 mol% based on the total amount of the phosphorus-containing compound.

Comparative Example 1 20 g per 100 g of the phosphorylated product obtained in Example 2 (containing 14.0 mol% of a compound having a pyrophosphoric acid bond with respect to the total amount of phosphorus-containing compounds) in a pressure vessel at a ratio of 20 g. Ion-exchanged water was added, and hydrolysis was performed at 105 ° C for 3 hours. The composition of the reaction product thus obtained, excluding water, was 72.2% by weight of monoalkylphosphoric acid, 13.1% by weight of dialkylphosphoric acid, 7.9% by weight of orthophosphoric acid and 6.8% by weight of unreacted alcohol. Further, in this reaction mixture, the compound having a pyrophosphate bond was significantly reduced to 0.02 mol% based on the total amount of the phosphorus-containing compound, but the yield of phosphoric acid ester was 95% compared to Example 2. Fell to%.

EXAMPLE 3 Diadol 115L (same as in Example 2) 190.7 g (1.00 mol) and 116% polyphosphoric acid 5 in a 1000 ml reaction vessel.
After adding 6.3 g [P ₂ O ₅ = 47.3 g (0.333 mol) and water = 9.0 g (0.5 mol)], the reaction was carried out at 60 ° C. for 2 hours. 24.0 g (0.167 mol) of phosphorus pentoxide (effective content 98.5 wt%) was gradually added to this reaction solution, and the reaction was further carried out at 80 ° C. for 10 hours. In the reaction mixture at this time, the compound having a pyrophosphate bond was present at 15.1 mol% with respect to the total amount of the phosphorus-containing compound. Then 10.0 g per 100 g of this reaction mixture
Ion-exchanged water was added at a ratio of, and hydrolysis was carried out at 90 ° C. for 3 hours. The composition of the reaction product thus obtained, excluding water, was 75.8% by weight of monoalkylphosphoric acid, 14.0% by weight of dialkylphosphoric acid, 6.0% by weight of orthophosphoric acid and 4.2% by weight of unreacted alcohol. Further, in this reaction mixture, the compound having a pyrophosphate bond was present in an amount of 0.15 mol% based on the total amount of the phosphorus-containing compound. Further, this reaction product was deodorized using a steam distillation apparatus with a forced thin film. The composition of the obtained residue excluding water was 79.1% by weight of monoalkylphosphoric acid, 14.4% by weight of dialkylphosphoric acid, 6.3% by weight of orthophosphoric acid, and 0.25% by weight of unreacted alcohol. The compound having a pyrophosphate bond was present in an amount of 0.12 mol% based on the total amount of the phosphorus-containing compound.

Example 4 Stearyl alcohol (Mw = 272.5) was added to a 1000 ml reaction vessel.
272.5 g (1.0 mol) and 85% phosphoric acid 23.5 g [P ₂ O ₅ = 1
4.5 g (0.102 mol) and water = 9.0 g (0.5 mol)] were added, and the mixture was stirred at 80 ° C for 0.5 hr. Next, gradually add 57.3 g (0.398 mol) of phosphorus pentoxide (effective content 98.5 wt%) to 90 ° C.
And reacted for 10 hours. In the reaction mixture at this time, the compound having a pyrophosphate bond was present at 12.1 mol% with respect to the total amount of the phosphorus-containing compound. After that, 5.0 g of ion-exchanged water was added to 100 g of this reaction mixture,
Hydrolysis was performed at 90 ° C. for 3 hours. The composition calculated by removing the water content of the reaction product thus obtained was 73.0% by weight of monostearyl phosphate, 18.2% by weight of distearyl phosphate,
Orthophosphoric acid 4.6% by weight, unreacted alcohol 4.2% by weight
Met. In addition, in this reaction mixture, the compound having a pyrophosphate bond was 0.06 with respect to the total amount of the phosphorus-containing compound.
It was present in mol%.

Example 5 Diadol 115L (same as in Example 2) 190.7 g (1.00 mol) and normal hexane 190.7 in a 2000 ml reaction vessel.
g and 106% polyphosphoric acid 554.7 g [P ₂ O ₅ = 425.8 g (3.00
Mol), water = 128.9 g (7.16 mol)], and then at 70 ° C
The reaction was performed for 12 hours. In the reaction mixture at this time, the compound having a pyrophosphate bond was present at 16.2 mol% with respect to the total amount of the phosphorus-containing compound. Then this reaction mixture
Ion-exchanged water was added at a ratio of 15.0 g to 100 g, and 70
Hydrolysis was carried out at ℃ for 3 hours. In the reaction mixture thus obtained, the compound having a pyrophosphate bond was present in an amount of 0.72 mol% based on the total amount of the phosphorus-containing compound. 100 g of this reaction mixture was added to normal hexane.
35 g, 15 g of ethanol and 30 g of water were added, and the mixture was heated to 50 ° C. and sufficiently stirred and mixed. After mixing for 30 minutes, the mixture was allowed to stand while being kept at 50 ° C., and immediately separated into a transparent normal hexane layer (upper layer) and a transparent water layer (lower layer). At this time, the composition calculated by removing water and normal hexane in the upper layer was 90.7% by weight of monoalkylphosphoric acid, 4.8% by weight of dialkylphosphoric acid, 2.5% by weight of orthophosphoric acid, and 2.0% by weight of unreacted alcohol. Further, in this reaction mixture, the compound having a pyrophosphate bond was present in an amount of 0.65 mol% based on the total amount of the phosphorus-containing compound.

Comparative Example 2 The phosphorylation reaction completed product obtained in Example 5 (containing 16.2 mol% of a compound having a pyrophosphate bond with respect to the total amount of the phosphorus-containing compound) was added to normal hexane and ethanol in the same manner as in Example 5. After adding water and water and stirring at 50 ° C. for 30 minutes, the mixture was allowed to stand. Even after 30 minutes, both the upper layer and the lower layer became cloudy and the intermediate layer was present. The compound having a pyrophosphate bond is present in this upper layer in an amount of 12.0 mol% based on the total amount of the phosphorus-containing compound. Since composition analysis cannot be performed in this state, 15.0 g of water was added to 100 g of the upper layer.
The pyrophosphate bond was hydrolyzed at 70 ° C. for 3 hours. At this time, the composition calculated by removing water and normal hexane in the upper layer was 86.2% by weight of monoalkylphosphoric acid, 4.5% by weight of dialkylphosphoric acid, 7.9% by weight of orthophosphoric acid, and 1.4% by weight of unreacted alcohol. Further, in this reaction mixture, the compound having a pyrophosphate bond was present in an amount of 0.11 mol% based on the total amount of the phosphorus-containing compound.

Comparative Example 3 Ion-exchanged water at a ratio of 30.0 g to 100 g of the phosphorylated product obtained in Example 5 (containing 16.2 mol% of a compound having a pyrophosphate bond with respect to the total amount of phosphorus-containing compounds). Was added and hydrolysis was carried out at 90 ° C. for 4 hours in a pressure vessel. In the reaction mixture thus obtained, the compound having a pyrophosphate bond was 0.02 with respect to the total amount of the phosphorus-containing compound.
It was a very low mol%. To 100 g of this reaction mixture, 35 g of normal hexane, 15 g of ethanol and 30 g of water were added, and the mixture was heated to 50 ° C. and sufficiently mixed with stirring. After mixing for 30 minutes, the mixture was allowed to stand while being kept at 50 ° C., and immediately separated into a transparent normal hexane layer (upper layer) and a transparent water layer (lower layer). At this time, the composition calculated excluding water and normal hexane in the upper layer was 90.7% by weight of monoalkylphosphoric acid, 4.8% by weight of dialkylphosphoric acid,
2.5 wt% orthophosphoric acid, 5.5 wt% unreacted alcohol
Met. Further, in this reaction mixture, the compound having a pyrophosphate bond was 0.02 with respect to the total amount of the phosphorus-containing compound.
It was present in mol%.

The results of Examples 1 to 5 and Comparative Examples 1 to 3 are summarized in Table 1.

[0032]

[Table 1]

Note) * 1: Phosphoric acid monoester purity of the reaction product after hydrolysis,
It is a value represented by the following formula.

[0034]

[Equation 1]

* 2: The amount of orthophosphoric acid in the reaction product after hydrolysis, which is a value represented by the following formula.

[0036]

[Equation 2]

Claims (3)

[Claims] 1. A method for producing a phosphoric acid ester by reacting one or more phosphorylating agents selected from the group consisting of phosphorus pentoxide, phosphoric acid and polyphosphoric acid with an organic hydroxy compound, wherein Water is added to the reaction product obtained by reacting the phosphorylating agent and the organic hydroxy compound, and the content of the compound having a pyrophosphate bond is 0.05 to 5 mol% relative to the total amount of the phosphorus-containing compound, and is present in the system. A method for producing a phosphoric acid ester, which comprises hydrolyzing a pyrophosphate bond. 2. The process for producing a phosphoric acid ester according to claim 1, wherein the hydrolysis is carried out at a temperature of 60 to 100 ° C. 3. The method for producing a phosphoric acid ester according to claim 1, wherein the organic hydroxy compound is a branched alcohol.