JPH115775A - Amine oxide production method - Google Patents

Abstract

(57) [Problem] To provide a method for producing an amine oxide having a good odor and a good long-term storage stability. SOLUTION: In producing the amine oxide represented by the general formula (I), after the amidoamine is reacted with hydrogen peroxide, the pH is adjusted to 9 to 13 by adding an alkali. Embedded image (In the formula, R ¹ represents an alkyl group having 7 to 25 carbon atoms, R ² and R ³ represent an alkyl group having 1 to ³ carbon atoms, and n represents a number of 2 to ^3. )

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 an amine oxide useful as a surfactant such as a detergent, and more particularly to a method for suppressing the decomposition of an amine oxide during storage.
The present invention relates to a method for producing an amine oxide having a good odor and a good long-term storage stability.

[0002]

2. Description of the Related Art Long-chain amidoalkylamine oxide is used as an auxiliary activator in various detergents, and its application range is dishwashing detergents, shampoos and clothing detergents. And so on. This long-chain amide alkylamine oxide can be used as an alkyl sulfate (AS) or an alkyl ethoxy sulfate (E
When added to an anionic activator such as S) or a nonionic activator such as alkyl ethoxylate or alkyl glucoside (AG), it exhibits an excellent foam increasing effect and a cleaning effect.

[0003] Such a long-chain amidoalkylamine oxide is stored in the form of a 30 to 35% by weight aqueous solution, or is lyophilized into a powder form, and then added to a product such as a detergent to produce a product system. Is stored in. However, during storage in such an aqueous solution or powder form, the decomposition and transfer reaction of the long-chain amide alkylamine oxide occur, causing deterioration of the odor.

Accordingly, an object of the present invention is to suppress the decomposition of long-chain amide alkylamine oxide during storage of long-chain amide alkylamine oxide or during storage in a product system to which long-chain amide alkylamine oxide is added, An object of the present invention is to provide a method for producing a long-chain amide alkylamine oxide having a good odor and a good long-term storage stability.

[0005]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems. As a result, after oxidizing amidoamine with hydrogen peroxide, the pH is adjusted to a specific pH range to improve the long-term storage stability. The present inventors have found that a long-chain amide alkylamine oxide can be obtained, and have completed the present invention. That is, the present invention provides a compound represented by the general formula (I):

[0006]

Embedded image

Wherein R ¹ represents a linear or branched alkyl, alkenyl or hydroxyalkyl group having 7 to 25 carbon atoms, and R ² and R ³ are the same or different and have 1 to 3 carbon atoms.
Represents an alkyl group or a hydroxyalkyl group, wherein n is 2
The numbers of ~ 3 are shown. In producing the amine oxide represented by the general formula (II)

[0008]

Embedded image

(Wherein R ¹ , R ² , R ³ and n have the same meanings as described above) and hydrogen peroxide, and then an alkali is added to adjust the pH to 9 to 9. The present invention provides a method for producing an amine oxide, which is adjusted to 13.

[0010]

Embodiments of the present invention will be described below in detail.

The amidoamine represented by the general formula (II) used as a raw material of the present invention has the general formula (III)

[0012]

Embedded image

(Wherein, R ¹ has the above-mentioned meaning, and R ⁴ represents H or a residue obtained by removing one acyloxy group from an alkyl group having 1 to 3 carbon atoms or glyceride.) A fatty acid or an ester thereof, and a compound represented by the general formula (IV)

[0014]

Embedded image

(Wherein R ² , R ³ and n have the same meanings as described above).

The higher fatty acid represented by the general formula (III) or its ester includes caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, behenic acid, erucic acid, 12-hydroxy Vegetable or animal oil fatty acids such as stearic acid, coconut oil fatty acid, cottonseed oil fatty acid, corn oil fatty acid, tallow fatty acid, babas oil fatty acid, palm kernel oil fatty acid, soybean oil fatty acid, linseed oil fatty acid, castor oil fatty acid, olive oil fatty acid, whale oil fatty acid Or a methyl ester, an ethyl ester, a glyceride thereof, or a mixture thereof is exemplified. Among these, R ⁴ is H or a higher fatty acid or a lower alkyl ester thereof, which is an alkyl group having 1 to 3 carbon atoms, and particularly preferable are those wherein R ¹ is a linear alkyl group having 9 to 17 carbon atoms. Wherein R ⁴ is H or CH ₃ , or a fatty acid derived from coconut oil or an ester thereof.

The diamine represented by the general formula (IV) includes dimethylaminopropylamine, dimethylaminoethylamine, diethylaminopropylamine, diethylaminoethylamine and the like. Of these, dimethylaminopropylamine is particularly preferred.

The molar ratio of the higher fatty acid or its ester represented by the general formula (III) and the diamine represented by the general formula (IV) in the reaction is higher fatty acid or its ester: diamine = 1: 1 to 1 : 2 is preferred, and 1: 1 to 1: 1.5
Is more preferred. The reaction represented by the general formula (II)
An amidoamine represented by the following formula is obtained. Particularly preferred amidoamines are those in which R ¹ is a straight-chain alkyl group having 9 to 17 carbon atoms, R ² and R ³ are methyl groups, and n is 3. .

In the present invention, as the hydrogen peroxide to be reacted with the amidoamine represented by the above general formula (II), an aqueous solution of 20 to 90% by weight is industrially available. Can be used in the invention, but generally 35% by weight
Are preferred. The amount of the aqueous hydrogen peroxide used is 1.0 to 1.0 mol of the amidoamine represented by the general formula (II).
It is preferably used in an amount of up to 1.05 mole times.

Water is generally used as the solvent for this reaction, but a water-soluble solvent such as methanol, ethanol, or isopropanol may be used in combination to adjust the viscosity of the amine oxide aqueous solution. Reaction temperature is 50 ~ 80 ℃
Is suitable, but may be carried out at a higher temperature to accelerate the reaction.

In the present invention, after reacting the amidoamine represented by the general formula (II) with hydrogen peroxide as described above, an alkali is added to adjust the pH to 9 to 13, preferably 10 to 10.
Adjust to ~ 12. Examples of the alkali used include an alkali metal hydroxide and an alkali metal carbonate, and an alkali metal hydroxide, particularly sodium hydroxide, is preferred. If the pH is out of the range of 9 to 13, the decomposition of the amine oxide cannot be suppressed, and the odor and the like are undesirably deteriorated during long-term storage.

In the present invention, the compound represented by the general formula (I)
The reaction product of the amidoamine represented by I) and hydrogen peroxide is bonded to a polybasic acid having at least one hydroxyl group and having 4 to 10 carbon atoms or a salt thereof, or a nitrogen atom. -CH ₂ COOM
Groups (M is hydrogen, alkali metal, alkaline earth metal,
Addition of one or more sequestering agents selected from aminopolycarboxylic acids having at least two ammonium or basic amino acid groups) or salts thereof is preferable because the decomposition of amine oxides can be further suppressed. .

Examples of the polybasic acid having at least one hydroxyl group and having 4 to 10 carbon atoms or salts thereof include citric acid, malic acid, tartaric acid, and alkali metal salts such as sodium salt and potassium salt thereof. -CH ₂ COOM which binds to a nitrogen atom
Examples of the aminopolycarboxylic acid having at least two groups or a salt thereof include ethylenediaminetetraacetic acid, nitrilotriacetic acid, diethylenetriaminepentaacetate, and alkali metal salts such as sodium salt and potassium salt thereof. Among these sequestering agents, citric acid, malic acid, tartaric acid, ethylenediaminetetraacetic acid or salts thereof are particularly preferred.

The amount of the sequestering agent to be added is preferably 0.005 to 3% by weight based on the amine oxide, and is preferably 0.01 to 3% by weight.
0.5% by weight is more preferred.

In the present invention, the decomposition and transfer reaction of the amine oxide can be suppressed by performing the above-mentioned treatment after reacting the amidoamine with hydrogen peroxide. According to the present invention, not only when the amine oxide is stored in the form of an aqueous solution, but also when the amine oxide aqueous solution is dried into a powder form by freeze-drying or the like, and then added to a product such as a detergent and stored in a product system. In addition, the decomposition and transfer reaction of the amine oxide can be suppressed. In particular, when the amine oxide is dried to a water content of 12% by weight or less, preferably 8% by weight or less to form a powder, the decomposition of the amine oxide becomes extremely large. It can be suppressed and is very preferable.

[0026]

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Production Examples and Examples, but the present invention is not limited to these Examples. The percentages in the examples are on a weight basis unless otherwise specified.

Production Example 1 200 g of lauric acid (Mw200) was placed in a 5-liter 1-liter flask equipped with a stirrer, thermometer, reflux condenser and pressure gauge.
, And the temperature was raised to 180 ° C. while blowing nitrogen gas at 100 cc / Hr from a capillary tube. Thereafter, 102 g (Mw102) of dimethylaminopropylamine was added dropwise over 3 hours, kept under these conditions for 2 hours, and the acid value (AV) was measured.
After confirming that it was 10 or less, it was cooled to 50 ° C. to obtain lauroylaminopropyldimethylamine.

Production Example 2 In a 5-liter 1-liter flask equipped with a stirrer, a thermometer, a reflux condenser and a pressure gauge, 207 g of coconut oil fatty acid (Mw 20
7), and supply nitrogen gas from the capillary tube at 100cc / Hr
The temperature was raised to 180 ° C while blowing. Thereafter, 102 g (Mw102) of dimethylaminopropylamine was added dropwise over 3 hours, kept under these conditions for 2 hours, and the acid value (AV) was measured to be 10 or less, and then cooled to 50 ° C. And cocoylaminopropyldimethylamine.

Examples 1-2 and Comparative Examples 1-2 Lauroylaminopropyldimethylamine (Mw284) 2840
g and 4,820 g of ion-exchanged water are charged into a 20-liter 5-neck flask equipped with a thermometer, a stirrer, a cooling tube, and a dropping funnel.
The temperature was raised to 80 ° C. After that, 35% hydrogen peroxide aqueous solution 971
g was added dropwise over 3 hours, followed by aging for 5 hours to complete the reaction. The product was an aqueous solution (pH 7) containing about 35% lauroylaminopropyldimethylamine oxide, and the content of lauroylaminopropyldimethylamine in the aqueous solution was 200 ppm.

A 600 ml aqueous solution of the obtained lauroylaminopropyldimethylamine oxide was added to a 200 ml beaker 4
Approximately 150 g of each was added, and the pH was adjusted to 4, 7, 10, and 12 using a 10% sodium hydroxide or 10% hydrochloric acid aqueous solution. Thereafter, the amine osakiide aqueous solution adjusted to each pH was divided into three portions with respect to the pH adjusted solution, placed in a 100 ml glass bottle with a lid, and stored in a thermostat at 30 ° C., 40 ° C. and 50 ° C. for one month, respectively. With respect to the amine oxide aqueous solution after storage, the content of lauroylaminopropyldimethylamine generated by elimination of oxygen was measured by ¹ H-NMR. Table 1 shows the results.

[0031]

[Table 1]

Examples 3 to 8 and Comparative Examples 3 to 8 By the same method as in Example 1, an aqueous solution of pH 7 containing about 35% lauroylaminopropyldimethylamine oxide was obtained. This aqueous solution was adjusted as shown below to obtain the following samples 1 to 12, and then lyophilized for 24 hours to obtain samples having the water contents shown in Table 2. 25 g of the lyophilized sample was added to a 50 ml bottle with a lid, sealed, stored at 80 ° C. for 24 hours, and subjected to a thermal stability test. Immediately after freeze-drying and after storage for 24 hours, the content of lauroylaminopropyldimethylamine formed by elimination of oxygen was measured in the same manner as in Example 1. Table 2 shows the results.

Sample 1: Unadjusted product, pH 7.0 (Comparative Example 3) Sample 2: 0.1 g of citric acid was added to and dissolved in 100 g of an aqueous solution of lauroylaminopropyldimethylamine oxide. pH was 6.6 (Comparative Example 4). Sample 3: 0.1 g of citric acid was added to 100 g of an aqueous solution of lauroylaminopropyldimethylamine oxide, and the pH was adjusted to 12 with a 10% aqueous solution of sodium hydroxide (Example 3). Sample 4: 100 g of an aqueous solution of lauroylaminopropyldimethylamine oxide was adjusted to pH 12 with a 10% aqueous solution of sodium hydroxide (Example 4). Sample 5: 0.1 g of citric acid was added to 100 g of an aqueous solution of lauroylaminopropyldimethylamine oxide, and the pH was adjusted to 9 with a 10% aqueous solution of sodium hydroxide (Example 5).

Sample 6: 0.1 g of ethylenediaminetetraacetic acid (EDTA) was added to 100 g of an aqueous solution of lauroylaminopropyldimethylamine oxide. pH was 6.6 (Comparative Example 5). Sample 7: 0.1 g of ethylenediaminetetraacetic acid (EDTA) was added to 100 g of an aqueous solution of lauroylaminopropyldimethylamine oxide, and the pH was adjusted to 12 with a 10% aqueous solution of sodium hydroxide (Example 6).

Sample 8: 0.1 g of malic acid was added to 100 g of an aqueous solution of lauroylaminopropyldimethylamine oxide.
g was added. pH was 6.7 (Comparative Example 6). Sample 9: 0.1 g of malic acid was added to 100 g of an aqueous solution of lauroylaminopropyldimethylamine oxide, and the pH was adjusted to 12 with a 10% aqueous solution of sodium hydroxide (Example 7).

Sample 10: 0.1 g of tartaric acid in 100 g of aqueous solution of lauroylaminopropyldimethylamine oxide
Was added. pH was 6.6 (Comparative Example 7). Sample 11: After adding 0.1 g of tartaric acid to 100 g of aqueous solution of lauroylaminopropyldimethylamine oxide,
The pH was adjusted to 12 with a 10% aqueous sodium hydroxide solution (Example 8). Sample 12: 0.1 g of lactic acid was added to 100 g of an aqueous solution of lauroylaminopropyldimethylamine oxide. pH is
6.6 (Comparative Example 8).

[0037]

[Table 2]

Examples 9-11 and Comparative Examples 9-11 2910 g of cocoylaminopropyldimethylamine (Mw291)
And 4890 g of ion-exchanged water were charged into a 20-liter 5-neck flask equipped with a thermometer, a stirrer, a condenser, and a dropping funnel.
The temperature was raised to ° C. Then, 971g of 35% aqueous hydrogen peroxide solution
Was added dropwise over 3 hours, followed by aging for 5 hours to complete the reaction. The product is an aqueous solution (pH 7) containing about 35% cocoylaminopropyldimethylamine oxide;
Cocoylaminopropyldimethylamine content in this aqueous solution was 200 ppm.

About 900 g of the obtained aqueous solution of cocoylaminopropyldimethylamine oxide was placed in a 200 ml beaker in an amount of about 150 g each, and the pH was adjusted to 4, 7, 10, 12 using a 10% sodium hydroxide or 10% hydrochloric acid aqueous solution. It was adjusted. At this time, pH 7 and 10 were each adjusted to two, and 0.15 g of citric acid was added to each of pH 7 and 10. Thereafter, each of the amine osakiide aqueous solutions prepared as described above was divided into three portions with respect to the prepared solution, placed in a 100 ml glass bottle with a lid, and stored in a thermostat at 40 ° C, 50 ° C, and 70 ° C for one month, respectively. For the aqueous amine oxide solution after storage, the content of cocoylaminopropyldimethylamine formed by elimination of oxygen was measured by ¹ H-NMR. Table 3 shows the results.

[0040]

[Table 3]

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Akira Fujio 1334 Minato, Wakayama City, Wakayama Pref.

Claims (5)

[Claims] 1. A compound of the general formula (I) (In the formula, R ¹ represents a linear or branched alkyl group, alkenyl group or hydroxyalkyl group having 7 to 25 carbon atoms, R ²
And R ³ are the same or different and represent an alkyl group having 1 to 3 carbon atoms or a hydroxyalkyl group, and n represents a number of 2 to 3. In producing the amine oxide represented by
General formula (II) (Wherein, R ¹ , R ² , R ³ and n have the same meanings as above), and after reacting with hydrogen peroxide, the pH is adjusted to 9 to 13 by adding an alkali. A method for producing an amine oxide. 2. In the general formula (I), R ¹ has 9 to 9 carbon atoms.
The method according to claim 1, wherein 17 linear alkyl groups, R ² and R ³ are methyl groups, and n is 3. 3. A reaction product of the amidoamine represented by the general formula (II) and hydrogen peroxide, a polybasic acid having at least one hydroxyl group and having 4 to 10 carbon atoms or a salt thereof, or a nitrogen atom One or two selected from aminopolycarboxylic acids having at least two -CH ₂ COOM groups (M represents a hydrogen atom, an alkali metal, an alkaline earth metal, ammonium or a basic amino acid group) or a salt thereof 3. The method according to claim 1, wherein at least one kind of sequestering agent is added. 4. The method according to claim 3, wherein the sequestering agent is citric acid, malic acid, tartaric acid, ethylenediaminetetraacetic acid or a salt thereof. 5. The process according to claim 3, wherein the amount of the sequestering agent is 0.005 to 3% by weight based on the amine oxide.