JPH1149741A - Production of alkanoylamidoalkylamine oxide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing the subject compound, by which the conversion of a tertiary amine is improved and the subject compound useful as a surfactant for a detergent, etc., is produced in high concentration by reacting the tertiary amine with an aqueous solution of hydrogen peroxide in a specific solvent in the presence of a polybasic acid, etc. SOLUTION: (A) A tertiary amine of the formula [R<1> is a 7-21C alkyl, etc.; R<2> and R<3> are each a 1-3C alkyl, etc.; (n) is 2-3], e.g. dodecylaminopropyldimethylamine is reacted with (B) an aqueous solution of hydrogen peroxide having 40-90 wt.% concentration in (C) a solvent selected from polyoxyalkylene ethers, organic esters, alcohols, etc., in the presence of (D) a polybasic acid having one or more hydroxy groups, such as citrie acid, or a salt thereof by using 10-60 wt.% component C and 0.1-5 wt.% component D based on the amount of the component A at 50-100 deg.C to provide the objective compound such as dodecylaminopropyldimethylamine oxide in >=45 wt.% concentration in the method for producing the alkanoylamidoalkylamine oxide.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a method for producing an alkanoylamide alkylamine oxide useful as a surfactant such as a detergent.

[0002]

2. Description of the Related Art Alkylamine oxides are known to exhibit an excellent foam-increasing effect and a detergency-enhancing effect, and are used, for example, as an auxiliary activator for various detergents. In addition, alkanoylamidoalkylamine oxide is characterized by being excellent in biodegradability and safety, and being less irritating to skin.

Amine oxide is synthesized by oxidizing a tertiary amine, and is generally produced by reacting it with an aqueous solution of hydrogen peroxide. However, when the concentration of the amine oxide exceeds about 30% by weight, the reaction solution becomes gel-like, and the production becomes difficult. Therefore, several methods for producing an amine oxide while controlling or avoiding gelation have been proposed.

In Japanese Patent Application Laid-Open No. 56-61349, Ueda et al. Preliminarily dissolve water in an amount corresponding to 10 to 40% by weight of an amine, and heat and agitate the mixture to give a concentration of 6 to 15% by weight. It discloses that an amine oxide is obtained by drop-wise reacting an aqueous solution of hydrogen peroxide at 10%. However, the resulting amine oxide aqueous solution has an amine oxide concentration of only 30 to 40.
% By weight.

In JP-A-3-120248, Smith et al. Reacted non-hygroscopic trialkylamine oxides by reacting trialkylamines with concentrated hydrogen peroxide (eg, 70% by weight) in an inert organic solvent. It discloses making dihydrate. However, in this method, the conversion of amine may decrease due to decomposition of hydrogen peroxide, and no application example to alkanoylamide alkylamine oxide is disclosed.

Further, Japanese Patent Publication No. 55060/1985 discloses reacting an aliphatic tertiary amine with an aqueous hydrogen peroxide solution in the presence of a polybasic acid or a salt thereof. But,
In this case, too, no application to alkanoylamidoalkylamine oxides is given and the product concentration is low.

[0007]

An object of the present invention is to provide a method for obtaining a reactant having a high concentration of alkanoylamidoalkylamine oxide in a product, specifically, a concentration of 45% by weight or more. And By doing so, it is intended to improve productivity, reduce transportation costs, increase the degree of freedom in compounding, and the like. Another object of the present invention is to suppress the decomposition of hydrogen peroxide and improve the conversion of tertiary amines.

[0008]

Means for Solving the Problems In order to solve the above-mentioned problems, the present inventors have made various studies, and when producing an alkanoylamide alkylamine oxide by reacting a tertiary amine with an aqueous hydrogen peroxide solution, Was carried out in a specific solvent and under heating in the presence of a polybasic acid or a salt thereof, whereby the concentration of alkanoylamide amine oxide in the reaction product itself could be increased, and the present invention was reached.

That is, the present invention provides the following general formula (I)

[0010]

Embedded image

Wherein R ¹ represents a linear or branched alkyl or alkenyl group having 7 to 21 carbon atoms, and R ² and R ³
Represents an alkyl group or a hydroxyalkyl group having 1 to 3 carbon atoms, and n represents a number of 2 to 3. ) Is reacted with an aqueous solution of hydrogen peroxide to produce a reaction product containing at least 45% by weight of an alkanoylamide alkylamine oxide, wherein saturated aliphatic hydrocarbons,
At least one solvent selected from the group consisting of saturated cyclic hydrocarbons, aromatic hydrocarbons, organic esters, alcohols, and polyoxyethylene alkyl ethers in an amount of 10 to 60% by weight based on the tertiary amine; Alkanoylamidoalkylamine oxide, characterized in that a polybasic acid having at least one hydroxyl group or a salt thereof is present in an amount of 0.1 to 5% by weight based on a tertiary amine, and the reaction is carried out at a temperature of 50 to 100 ° C. It provides a manufacturing method.

According to the production method of the present invention, as described above, the concentration of alkanoylamide alkylamine oxide in the reaction product can be increased, and the solvent can be easily removed. As a result, it is possible to obtain a product having a higher concentration of alkanoylamidoalkylamine oxide with less energy consumption than in a case where water is removed from a low-concentration aqueous solution.

Further, when polyoxyethylene alkyl ethers are used as the solvent, there is an advantage that the solvent need not be removed and the reaction product can be directly blended into a detergent or the like.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The amine oxide produced according to the present invention is an alkanoylamide alkylamine oxide represented by the following formula (II) corresponding to the above formula (I).

[0015]

Embedded image

(In the formula (II), R ^{1 to} R ³ and n have the same meanings as described above.) Examples of the tertiary amine of the raw material represented by the formula (I) include octylaminopropyldimethylamine, Decylaminopropyldimethylamine, dodecylaminopropyldimethylamine, tridecylaminopropyldimethylamine, tetradecylaminopropyldimethylamine, hexadecylaminopropyldimethylamine, decylaminopropyldihydroxyethylamine, dodecylaminopropyldihydroxyethylamine, decylaminoethylmethylamine , Dodecylaminoethyldimethylamine and the like. Of these, decylaminopropyldimethylamine, dodecylaminopropyldimethylamine, tridecylaminopropyldimethylamine, tetradecylaminopropyldimethylamine, and the like are more preferable because amine oxides having excellent detergency and foaming properties can be obtained. .

The aqueous hydrogen peroxide solution to be reacted with the tertiary amine as described above preferably has a hydrogen peroxide concentration in the aqueous solution.
It is 40-90% by weight, more preferably 60-80% by weight, even more preferably 65-70% by weight. If the concentration of hydrogen peroxide in the aqueous solution is too high, the stirring state is deteriorated and the decomposition of the amine oxide is promoted. On the other hand, if the concentration is too low, the concentration of the product is reduced and productivity is deteriorated. The preferred range described above is determined based on such a viewpoint.

The aqueous hydrogen peroxide solution is preferably charged in such an amount that the molar ratio of the tertiary amine to hydrogen peroxide is 1: 0.9 to 1.4. The amount is more preferably 1: 1.0 to 1.3, and still more preferably 1: 1.05 to 1.25.
If the molar ratio of hydrogen peroxide is small, the reaction time tends to be long and the residual tertiary amine tends to increase. Conversely, if the molar ratio of hydrogen peroxide is large, the amount of residual hydrogen peroxide after the reaction increases, and a side reaction tends to occur. The amount of water in the product can be controlled to a desired value depending on the concentration and amount of the aqueous hydrogen peroxide solution used.

In the present invention, as the solvent, saturated aliphatic hydrocarbons, saturated cyclic hydrocarbons, aromatic hydrocarbons,
One or more solvents selected from the group consisting of organic esters, alcohols, and polyoxyethylene alkyl ethers are used. Among these, preferred examples from the viewpoint of improving the conversion of the tertiary amine and removing the solvent after the reaction include saturated aliphatic hydrocarbons having 5 to 10 carbon atoms,
C 5-10 saturated cyclic hydrocarbons, C 5-10 aromatic hydrocarbons, C 2-6 fatty acids and C 1-6
And organic alcohols having 3 to 8 carbon atoms, and polyoxyethylene alkyl ethers having 10 to 16 carbon atoms in the alkyl group. Specific examples of these compounds include saturated aliphatic hydrocarbons such as n-hexane, n-heptane, and n-octane; saturated cyclic hydrocarbons such as cyclohexane and cycloheptane; and aromatic hydrocarbons such as toluene. , Xylene and the like organic esters such as methyl acetate, ethyl acetate,
Examples of alcohols include isopropyl alcohol, and polyoxyethylene alkyl ethers include polyoxyethylene lauryl ether.

The above solvent is used in an amount sufficient to stir and mix the reactants. Specifically, the amount is 10 to 60% by weight based on the tertiary amine. If the amount is too small, the mixed state of the reactants deteriorates, and the decomposition of hydrogen peroxide tends to be promoted. If the amount is too large, the concentration of the alkanoylamidoalkylamine oxide in the reaction product will decrease, and the productivity will decrease, and the cost efficiency of solvent removal will tend to decrease. From this viewpoint, more preferably, the amount of the solvent is 20 to 50% by weight based on the tertiary amine.
It is.

In the process of the present invention, the solvent is reacted after the reaction.
It can be removed by methods such as distillation and crystallization filtration. In this case, the energy consumption can be reduced as compared with the case where water is removed from the aqueous solution.
Also, when using polyoxyethylene alkyl ethers as a solvent, since it is an activator itself,
It can be directly incorporated into a cleaning agent or the like without removal.

According to the present invention, a polybasic acid having one or more hydroxyl groups or a salt thereof is added for the purpose of suppressing the decomposition of hydrogen peroxide and improving the conversion of amine.
Preferred as such compounds are citric acid, isocitric acid, tartaric acid, malic acid, or alkali metal salts thereof. The amount of the tertiary amine is 0.1 to 5% by weight, preferably 0.2 to 2% by weight. If the amount is too small, the desired effect is difficult to achieve, and if the amount is too large, a large amount remains in the product, so that the concentration of the alkanoylamidoalkylamine oxide in the product is relatively small.

The production method of the present invention may be a method in which a tertiary amine is first charged and hydrogen peroxide is added thereto, or a method in which the tertiary amine and hydrogen peroxide are simultaneously charged. For example, when the tertiary amine is charged first and the aqueous hydrogen peroxide solution is added thereto to perform the charging, the addition time of the aqueous hydrogen peroxide solution depends on the temperature and the scale. Preferably 5 minutes to 24 hours. More preferably, it is about 10 minutes to 2 hours. If the addition time is too short, a large amount of unreacted hydrogen peroxide stays, so that decomposition of hydrogen peroxide and side reactions tend to occur, and the temperature tends to rise due to reaction heat.
On the other hand, if the addition time is too long, the productivity will deteriorate.

After adding the hydrogen peroxide, it is preferable to keep the stirring state in order to increase the conversion. The time for that depends on the temperature, but is preferably about 30 minutes to 24 hours, and more preferably about 1 to 8 hours. Here, according to the present invention, the temperature at the time of adding hydrogen peroxide and maintaining the stirring state is not lower than the temperature at which the reactants can be stirred and mixed and not higher than the decomposition temperature of the generated amine oxide, specifically 50. -100 ° C, preferably 80-90 ° C. The conversion rate (Y) of the tertiary amine is as follows: Y = [C _AO / (C _A + C _AO )] × 100 where Y [%]: Conversion rate of the tertiary amine C _A [mol / m ³ ]: Concentration of tertiary amine C _AO [mol / m ³ ]: Concentration of amine oxide, for example, reacting the reaction product with a nuclear magnetic resonance analyzer (NMR)
It can be obtained by performing analysis using the above.

According to the production method of the present invention, the alkanoylamidoalkylamine oxide is obtained at a concentration of 45% by weight or more. It is preferably obtained at a concentration of 50% by weight or more, more preferably at a concentration of 60% by weight or more. Therefore, the productivity of amine oxide can be improved, and concomitant reduction in transportation cost can be achieved.

The reaction product contains a solvent, which can be easily removed by a method such as distillation, crystallization filtration or the like as described above. As a result, a high-concentration alkanoylamide alkylamine oxide product containing no solvent can be obtained. When polyoxyethylene alkyl ethers are used as the solvent, removal is unnecessary because the polyoxyethylene alkyl ether itself is an activator as described above.

When unreacted hydrogen peroxide is present in the reaction product, decomposition can be carried out, if necessary, by a known method (for example, addition of an aqueous solution of sodium hydroxide) before removing the solvent. In this case, the presence of the solvent of the present invention has an effect of suppressing foaming.

The form of the product obtained by the production method of the present invention can be any desired one depending on the application. For example, the solvent can be distilled off from the reaction product to form a paste, which can be formed into a flake shape, a noodle shape, or the like using a flaker or an extruder. Further, the solvent can be removed from the reaction product by crystallization filtration to obtain a crystalline product.

[0029]

Embodiments of the present invention will be described below, but it goes without saying that the present invention is not limited to these embodiments.

Example 1 500 m capacity equipped with thermometer, cooling pipe, dropping funnel, stirring blade
In a 1 l reaction vessel, 200 g of dodecylaminopropyldimethylamine as a raw material, 40 g of isopropyl alcohol (20% by weight of tertiary amine), and 1 g of citric acid (0.5% by weight of tertiary amine) were charged, and the temperature was raised to 80 ° C. . Thereafter, while stirring, 42.2 g of a 68% by weight aqueous hydrogen peroxide solution (molar ratio of tertiary amine: 1.2) was added dropwise over 15 minutes, and the mixture was aged at 80 ° C. for 6 hours to complete the reaction. The conversion of the tertiary amine was determined by NMR to be 99.5%. The concentration of dodecylaminopropyldimethylamine oxide was 75% by weight.

Example 2 500 m capacity equipped with thermometer, cooling pipe, dropping funnel and stirring blade
In a 1 l reaction vessel, 200 g of tetradecylaminopropyldimethylamine as a raw material and 40 g of ethyl acetate (based on tertiary amine 20
% By weight) and 1 g of citric acid (based on 0.5% by weight of tertiary amine), and the temperature was raised to 80 ° C. Thereafter, while stirring, 40.2 g of a 68% by weight aqueous hydrogen peroxide solution (molar ratio of tertiary amine: 1.2) was added dropwise over 15 minutes, and the mixture was aged at 80 ° C. for 6 hours to complete the reaction. The conversion of the tertiary amine determined by NMR was 99.2%. The concentration of tetradecylaminopropyldimethylamine oxide was 75% by weight.

Example 3 500 m capacity equipped with a thermometer, cooling pipe, dropping funnel and stirring blade
In a 1 l reaction vessel, 200 g of raw material dodecylaminopropyldimethylamine, 50 g of n-hexane (25% by weight of tertiary amine), 1 g of disodium citrate (0.1 g of tertiary amine).
5% by weight) and heated to 80 ° C. Thereafter, while stirring, 42.2 g of 68% by weight aqueous hydrogen peroxide solution (to 3
Grade amine molar ratio 1.2) was added dropwise over 15 minutes, and the mixture was aged at 80 ° C. for 6 hours to complete the reaction. The conversion of the tertiary amine determined by NMR was 99.4%. The concentration of dodecylaminopropyldimethylamine oxide was 70% by weight.

Example 4 500 m capacity equipped with a thermometer, cooling pipe, dropping funnel and stirring blade
l, 200 g of dodecylaminopropyldimethylamine as a raw material and polyoxyethylene lauryl ether 1
20 g (60% by weight of tertiary amine) and 1 g of citric acid (0.5% by weight of tertiary amine) were charged, and the temperature was raised to 80 ° C. Thereafter, while stirring, 42.2% aqueous solution of 68% by weight hydrogen peroxide was used.
g (to a tertiary amine molar ratio of 1.2) was added dropwise over 15 minutes.
The reaction was completed by aging for 8 hours at ℃. The conversion of the tertiary amine determined by NMR was 98.5%. The concentration of dodecylaminopropyldimethylamine oxide was 55% by weight.

Comparative Example 1 A reaction was carried out in the same manner as in Example 1 except that isopropyl alcohol as a solvent was not added. During the course of the dropping reaction, the viscosity of the reaction product increased, stirring became impossible, and a non-uniform state in which a white paste and a liquid were partially mixed was obtained. After aging for 6 hours, the conversion was determined by NMR to be 50%.

Comparative Example 2 A reaction was carried out in the same manner as in Example 1 except that the additive citric acid was not added. The reaction state was almost the same as in Example 1. The conversion of the tertiary amine by NMR was 85%. The concentration of dodecylaminopropyldimethylamine oxide was 75% by weight.

The above results are summarized in Table 1.

[0037]

[Table 1]

[0038]

As described above, according to the present invention, the conversion of tertiary amine can be improved and the concentration of alkanoylamidoalkylamine oxide in the product can be reduced to 45%.
It is possible to obtain a reaction product as high as not less than% by weight. Therefore, the productivity can be improved and the transportation cost can be reduced, and the solvent can be easily removed.

Claims (3)

[Claims] 1. A compound of the general formula (I) (Wherein, R ¹ represents a linear or branched alkyl or alkenyl group having 7 to 21 carbon atoms, R ² and R ³ each represent an alkyl group or a hydroxyalkyl group having 1 to 3 carbon atoms, and n Represents a number of 2 to 3.) When a tertiary amine represented by the formula (1) is reacted with an aqueous hydrogen peroxide solution to produce a reaction product containing at least 45% by weight of an alkanoylamide alkylamine oxide, a saturated aliphatic hydrocarbon is used. , A saturated cyclic hydrocarbon, an aromatic hydrocarbon, an organic ester, an alcohol, a polyoxyethylene alkyl ether, and at least one solvent selected from the group consisting of
6060 wt% and a polybasic acid having one or more hydroxyl groups or a salt thereof is present in an amount of 0.1-5 wt% based on the tertiary amine, and the reaction is carried out at a temperature of 50-100 ° C.
A method for producing an alkanoylamide alkylamine oxide. 2. The method according to claim 1, wherein the concentration of hydrogen peroxide in the aqueous hydrogen peroxide solution is 40 to 90% by weight. 3. The method according to claim 1, wherein the solvent is a polyoxyethylene alkyl ether.