JPH10168052A - Production of amine oxide - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject compound with excellent long-term storage stability, useful as a surfactant, in the form of e.g. a detergent, by oxidizing a tertiary amine with H2 O2 and adjusting to a specific pH range. SOLUTION: This amine oxide represented by formula II is produced by reacting a tertiary amine (e.g. dimethyloctylamine), represented by formula I (R<1> is a 8-26C alkyl, etc.; R<2> is a 1-26C alkyl, etc.; R<3> is 1-3C alkyl, etc.) with normally 35wt.% aqueous H2 O2 , in a molar ratio of 1:(1.0-1.05) at 50-80 deg.C, followed by adjusting the system of pH9-13, preferably, pH10-12 by addition of an alkali, such as NaOH. To further suppress decomposition of the reaction product, the compound of formula II, it is preferable to add a metal blocking agent in an amount corresponding to 0.005-3wt.% of the compound of formula II.

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 Alkylamine oxide is used as an auxiliary activator in various detergents, and its application range is wide-ranging, such as dishwashing detergents, shampoos and clothing detergents. . When this alkylamine oxide is added to an anionic activator such as alkyl sulfate (AS) or alkyl ethoxy sulfate (ES) or a nonionic activator such as alkyl ethoxylate or alkyl glucoside (AG),
Shows excellent foaming and cleaning effects.

[0003] Such amine oxides are available in the range of 30 to 35
It is stored in the form of a weight% aqueous solution or freeze-dried into a powder form, added to a product such as a detergent, and stored in a product system. However, during storage in the form of an aqueous solution or a powder, the decomposition and transfer reaction of the amine oxide occur, causing the odor to deteriorate.

Accordingly, an object of the present invention is to provide an amine oxide which suppresses the decomposition of the amine oxide during storage of the amine oxide or during storage in a product system to which the amine oxide is added, and has a good odor and good long-term storage stability. It is to provide a method of manufacturing the.

[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, the tertiary amine is oxidized with hydrogen peroxide and then adjusted to a specific pH range to thereby provide a long-term storage stability. The present inventors have found that an amine oxide having a good quality can be obtained, and have completed the present invention. That is, the present invention provides a compound represented by the general formula (I):

[0006]

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Wherein R ¹ represents a linear or branched alkyl or alkenyl group having 8 to 26 carbon atoms, and R ² represents
Represents a straight-chain or branched-chain alkyl group or alkenyl group having up to 26 carbon atoms or a hydroxyalkyl group having 1 to ³ carbon atoms, and R ³ represents an alkyl group or hydroxyalkyl group having 1 to ³ carbon atoms. In producing the amine oxide represented by the general formula (II)

[0008]

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(Wherein R ¹ , R ² and R ³ have the same meanings as described above) and hydrogen peroxide, and then 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 tertiary amine represented by the general formula (II) used as a raw material of the present invention includes dimethyloctylamine, dimethyl (2-ethylhexyl) amine, dimethyldecylamine, dimethyldodecylamine, dimethyltridecylamine , Dimethyltetradecylamine, dimethylhexadecylamine, dimethyloctadecylamine, dimethyl (2-octyldodecyl) amine, dimethylbehenylamine, dihydroxyethyloctylamine, dihydroxyethyldecylamine, dihydroxyethyldodecylamine, dihydroxyethyltetradecylamine, dihydroxy Ethyl octadecylamine, dihydroxyethyl behenylamine, methyldioctylamine, methyldi (2-ethylhexyl) amine, methyloctyldecylamine Methyl didecyl amine, methyl didodecylamine, methyl dihexadecylamine, methyl hexadecyl octadecyl amine, methyl dioctadecyl amine, methyl-di-behenyl amine and the like.

Among them, R ¹ is a linear or branched alkyl or alkenyl group having 8 to 18 carbon atoms, R ² is an alkyl or hydroxyalkyl group having 1 to ³ carbon atoms, and R ³ is a carbon or alkyl group. Those having 1 to 3 alkyl groups or hydroxyalkyl groups are preferred.

In the present invention, as the hydrogen peroxide to be reacted with the tertiary amine represented by the above general formula (II), an aqueous solution of 20 to 90% by weight is industrially available. Can also be used in the present invention, but generally 35% by weight is preferred. The amount of the aqueous hydrogen peroxide used is 1.0 to 1.1 mol per mol of the tertiary amine represented by the general formula (II).
It is preferable to use 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 the tertiary amine represented by the general formula (II) is reacted with hydrogen peroxide as described above, the pH is adjusted to 9 to 13, preferably 10 to 13, by adding an alkali.
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 deteriorate during long-term storage, which is not preferable.

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

Examples of the polybasic acid having at least one hydroxyl group and having 4 to 10 carbon atoms or a salt 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 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 tertiary amine 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. Especially,
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, but the decomposition of the amine oxide is suppressed by the treatment of the present invention. Can be very favorable.

[0020]

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

Examples 1 and 2 and Comparative Examples 1 and 2 2460 g of lauryl dimethylamine (Mw246) and deionized water
4060 g was equipped with a thermometer, stirrer, cooling tube and dropping funnel
The mixture was charged into a 20-liter 5-neck flask and heated to 80 ° C. Thereafter, 971 g of a 35% aqueous hydrogen peroxide solution was added dropwise over 3 hours, followed by aging for 5 hours to terminate the reaction. The product was an aqueous solution (pH 7) containing 35% lauryl dimethylamine oxide, and the aqueous solution had a lauryl dimethylamine content of 200 ppm.

About 600 g of the obtained aqueous solution of lauryl dimethylamine oxide was added to four 200 ml beakers each for about 1 part.
50 g each was added, and the pH was adjusted to 4, 7, 10, 12 using 10% sodium hydroxide or 10% aqueous hydrochloric acid. afterwards,
The amine osakiide aqueous solution adjusted to each pH was divided into three parts with respect to the pH-adjusted solution, placed in a 100 ml glass bottle with a lid, and stored for one month in a thermostat at 30 ° C, 40 ° C and 50 ° C, respectively. About the amine oxide aqueous solution after storage, ¹
The content of lauryl dimethylamine formed by elimination of oxygen was measured by H-NMR. Table 1 shows the results.

[0023]

[Table 1]

Examples 3 to 8 and Comparative Examples 3 to 8 An aqueous solution of pH 7 containing 35% lauryl dimethylamine oxide was obtained in the same manner as in Example 1. 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 lyophilization and after storage for 24 hours, the content of lauryl dimethylamine produced 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: Lauryl dimethylamine oxide aqueous solution
0.1 g of citric acid was added to and dissolved in 100 g. pH 6.6
(Comparative Example 4). Sample 3: Lauryl dimethylamine oxide aqueous solution
After adding 0.1 g of citric acid to 100 g, the pH was adjusted to 12 with a 10% aqueous sodium hydroxide solution (Example 3). Sample 4: Lauryl dimethylamine oxide aqueous solution
100 g was adjusted to pH 12 with a 10% aqueous sodium hydroxide solution (Example 4). Sample 5: Lauryl dimethylamine oxide aqueous solution
After 0.1 g of citric acid was added to 100 g, the pH was adjusted to 9 with a 10% aqueous sodium hydroxide solution (Example 5).

Sample 6: 100 g of an aqueous solution of lauryl dimethylamine oxide was added to ethylenediaminetetraacetic acid (ED
TA) was added in an amount of 0.1 g. The pH was 6.6 (Comparative Example 5). Sample 7: aqueous solution of lauryl dimethylamine oxide
0.1 g of ethylenediaminetetraacetic acid (EDTA) to 100 g
After the addition, the pH was adjusted to 12 with a 10% aqueous sodium hydroxide solution (Example 6).

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

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

[0029]

[Table 2]

 ──────────────────────────────────────────────────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) (Wherein, R ¹ represents a linear or branched alkyl or alkenyl group having 8 to 26 carbon atoms, and R ² represents a linear or branched alkyl or alkenyl group having 1 to 26 carbon atoms, or Number 1
Represents 3 to 3 hydroxyalkyl groups, and R ³ has 1 to ³ carbon atoms.
Represents an alkyl group or a hydroxyalkyl group. In producing the amine oxide represented by the general formula (I)
I) (Wherein, R ¹ , R ² and R ³ have the same meanings as above), and after reacting the tertiary amine 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 from 8 to 8 carbon atoms.
18 linear or branched alkyl or alkenyl groups, R ²
Is an alkyl group or hydroxyalkyl group having 1 to ³ carbon atoms, and R ³ is an alkyl group or hydroxyalkyl group having 1 to ³ carbon atoms. 3. A polybasic acid having at least one hydroxyl group and having 4 to 10 carbon atoms or a salt thereof, or a reaction product of the tertiary amine represented by the general formula (II) and hydrogen peroxide, or One selected from aminopolycarboxylic acids or salts thereof 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) bonded to a nitrogen atom 3. The method according to claim 1, wherein two or more sequestering agents are 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.