JP3505366B2 - Method for producing amine oxide type surfactant - 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 an amine oxide type surfactant capable of obtaining a high quality target product by a smooth reaction operation.

[0002]

2. Description of the Related Art Lauryl dimethylamine oxide is a typical amine oxide type surfactant, and it can be used as dishwashing detergent, household detergent, shampoo, whole body cleaning agent, etc. Is commonly used as. In addition to those containing an amide bond or an ether bond, there are some amine oxide-type surfactants such as stearyldimethylamine oxide, which are being studied for development into conditioning agents by extending the alkyl chain length.

Amine oxide type surfactants such as lauryl dimethylamine oxide are generally added to a mixture of a tertiary amine and water with an aqueous solution of hydrogen peroxide to give 70-
By aging at 80 ° C., a 30 to 40 wt% aqueous solution can be obtained. However, when the carbon number of the alkyl group becomes large like stearyl dimethylamine oxide, the reaction system may gel during the addition of the hydrogen peroxide aqueous solution or during the aging after the addition, and it may not be possible to sufficiently stir. Such a phenomenon is caused by USP 3432555.
Also in the example of the above, it is made clear by the expression "becomes pale". When this gelation occurs, stirring is not sufficient, so problems such as deterioration in quality due to local heating and rapid increase in reaction temperature due to insufficient removal of reaction heat between amine and hydrogen peroxide. Etc. occur.

In order to solve such a problem, heavy equipment having a strong stirring force such as a kneader is required, which is economically disadvantageous. Further, a method of preventing gelation by adding water (Japanese Patent Publication No. 41-9294, Japanese Patent Laid-Open No. 56-6134).
No. 9) and a method of adding an inorganic salt such as sodium sulfate (USP34638317). However, the method of preventing gelation by adding water is uneconomical because a large amount of water is required, and the concentration of the amine oxide type surfactant in the produced aqueous solution is also 10% by weight or less, so that it can be used afterwards. Will also cause problems.
Further, the method of adding an inorganic salt, although the state of the gel is slightly improved, has not been a fundamental solution.

The present invention provides a method for producing an amine oxide type surfactant, which can prevent gelation in the process of producing the amine oxide type surfactant and obtain a high quality target product by a smooth reaction. With the goal.

[0006]

Means for Solving the Problems As a result of repeated studies to achieve the above object, the present inventors found that the cause of gelation was "water and hydrogen peroxide" and "amine as a raw material".
It was found that the three elements of “the amine oxide as a product” coexist in a certain proportion in the reaction system (see FIG. 1. FIG. 1 is a model of the coexisting state of the three elements at 80 ° C.). The values on each axis are% by weight.
In the display, the shaded area indicates that gelation has occurred). That is, in the process of producing a 35% by weight aqueous solution of stearyldimethylamine oxide by the conventional method (method of dropping hydrogen peroxide into a mixture of amine and water) (shown by the line ABCS), A- Between B, water and amine were mixed without being dissolved, gelation started in B, gel disappeared in C, and 35% by weight of low viscosity
From the fact that the aqueous solution of stearyl dimethylamine oxide (S) was obtained, focusing on the relationship between the concentration and state change of the three elements, and by appropriately maintaining the amine concentration, gelation was prevented, and high concentration It has been found that an aqueous solution of stearyldimethylamine oxide can be obtained.
However, when water is added by applying the techniques described in JP-B-41-9294 and JP-A-56-61349 (shown by line DE), gelation is avoided. Although it was possible, it was confirmed that only a low concentration of stearyldimethylamine oxide in the resulting aqueous solution of about 10% by weight was obtained.

[0007] Therefore, as a result of further studies based on these findings, the present inventors applied an effective and simple method for controlling the amine concentration in the reaction system to a certain concentration or less. By doing so, it was found that the amine oxide type surfactant having a concentration (20% by weight or more) industrially satisfactory can be finally obtained while avoiding the gelation region shown in FIG. 1 and thus completed the present invention. .

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

[0009]

[Chemical 3]

[Wherein R ¹ represents a linear or branched alkyl or alkenyl group having 8 to 22 carbon atoms, which may contain an ester bond, an amide bond or an ether bond, and R 1
² represents a linear or branched alkylene group having 2 to 6 carbon atoms, R ³ and R ⁴ represent an alkyl group or hydroxyalkyl group having 1 to 4 carbon atoms, and A represents —O—, — C (=
O) NH- or -NHC (= O)-is shown, and n is 0 to
In the method for producing an amine oxide type surfactant represented by the formula [10], the following general formula (II):

[0011]

[Chemical 4]

When the amine represented by the formula [R ^{1 to} R ⁴ , A and n have the same meaning as described above] and hydrogen peroxide are reacted, the concentration of the amine in the reaction system is 5% by weight or less. And a method for producing an amine oxide-type surfactant.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION
By reacting the amine of I) with hydrogen peroxide in an aqueous solvent, an amine oxide type surfactant represented by the general formula (I) is obtained.

The amine of the general formula (II) used in the production method of the present invention is a straight chain or branched chain having 8 to 22 carbon atoms in which R ¹ may have an ester bond, an amide bond or an ether bond. A chain alkyl or alkenyl group, preferably a straight chain or branched chain alkyl or alkenyl group having 16 to 22 carbon atoms. When R ¹ contains an ester bond, an amide bond or an ether bond, its bonding position is not particularly limited.

Hydrogen peroxide used in the production method of the present invention is
A generally available 35-60% aqueous solution can be used, and if necessary, it can be diluted with water or an organic solvent to a desired concentration.

As the aqueous solvent used in the production method of the present invention, water can be mentioned. In addition, water and an organic solvent,
For example, mention may be made of a mixture with ethanol, isopropanol, ethylene glycol or propylene glycol. When the aqueous solvent is a mixture of water and an organic solvent, the content of water is preferably 20 to 80% by weight.

In the production method of the present invention, if necessary, for example, a chelating agent, a chelating auxiliary agent, a viscosity adjusting agent,
Other additives can be added.

The chelating agent and chelating auxiliary agent are for preventing the reduction of the reaction rate due to the decomposition of hydrogen peroxide during the reaction. For example, citric acid, ethylenediaminetetraacetate (EDTA), diethylenetriaminepentaacetate (DTPA). , Nitrile triacetonitrile (NTA), malic acid, maleic acid, succinic acid, and sodium stannate. Examples of the viscosity modifier include alcohols such as ethanol, isopropanol, ethylene glycol and 1,2-propylene glycol. Examples of other additives include ascorbic acid (low nitrosamine conversion), phenolic antioxidant (colored odor preventing agent), silicone (antifoaming agent) and the like.

In the production method of the present invention, in order to prevent gelation when the reaction is carried out using the above raw material components,
The amine represented by the general formula (II) in the reaction system (hereinafter,
The concentration of “only amine” is 5% by weight or less, preferably 4% by weight or less. Therefore, in the production method of the present invention, in order to achieve the object of the present invention by keeping the amine concentration below a predetermined concentration, (1) a production method of adding amine to hydrogen peroxide (amine addition method) or (2) ) It is preferable to apply a manufacturing method (simultaneous addition method) in which hydrogen peroxide and an amine are simultaneously added. Hereinafter, each manufacturing method will be described in detail. In the following description of the manufacturing method, the case where water is used as the aqueous medium will be described.

(1) Amine Addition Method This production method is a method of adding amine or amine and water to an aqueous hydrogen peroxide solution, and this method will be described with reference to FIG. First, water and hydrogen peroxide are charged (point F), and then the amine is added little by little by a dropping method or the like so that the concentration becomes 5% by weight or less. The addition of this amine
Considering the relationship between the added amount of amine and the consumed amount of amine due to the formation of amine oxide, the addition is performed so as to form a curve F-G-S. At this time, if the addition rate of the amine is too fast (the amount of addition of the amine is too large, that is, the amine concentration exceeds 5% by weight), for example, a curve F-H-S will be obtained, and the reaction process will be performed. Gelation will occur.

Next, the reaction conditions will be described. The molar ratio of amine to hydrogen peroxide is preferably 1: 0.95-
The ratio is 1.3, particularly preferably 1: 1.0 to 1.2, and further preferably 1: 1.05 to 1.10.
The temperature at which the amine is added (reaction temperature) accelerates the reaction and prevents the rapid decomposition of hydrogen peroxide.
In order to prevent the reaction rate from decreasing, it is preferably 40 to 100.
C., particularly preferably 50 to 90.degree. C., and further preferably 70 to 90.degree. The addition time is preferably 0.5 to 24 hours, particularly preferably 1.0 to 20 hours in order to keep the amine concentration below a predetermined concentration and prevent the reaction heat from rising excessively. The reaction is
Stirring is performed with a turbine type stirring blade or the like.

By adding carbon dioxide to the reaction system, the addition time of amine can be shortened.
As this method, for example, when hydrogen peroxide is added dropwise to a tertiary amine described in JP-B-57-47182, page 1, right column, lines 17 to 24 to produce a corresponding amine oxide, A method of terminating the reaction in a short time by applying carbon dioxide gas can be applied. The amount of carbon dioxide used is preferably 0.
It is 01 to 5%, and particularly preferably 0.03 to 2%. As a method of adding carbon dioxide, a method of circulating the carbon dioxide in the reaction system, a method of dissolving it in an aqueous hydrogen peroxide solution in advance, or the like can be applied.

(2) Simultaneous addition method This production method is a method of simultaneously adding amine and hydrogen peroxide to water by a dropping method or the like. "Simultaneous" in this method is not limited to simultaneously adding all the amounts of amine and hydrogen peroxide, but also includes simultaneously adding only a part of amine and hydrogen peroxide.
Therefore, for example, a part of hydrogen peroxide may be previously charged together with water, and the entire amount of amine and the balance of hydrogen peroxide may be simultaneously added thereto. Also in this method, as in the amine addition method, the addition is performed so as to form a curve F-G-S. This simultaneous addition method, compared to the amine addition method,
Since the initial hydrogen peroxide concentration in the reaction system can be lowered, the reaction can proceed more smoothly, which is preferable. The reaction conditions are the same as in the amine addition method, and carbon dioxide can be allowed to be present in the reaction system in the same manner as in the amine addition method.

The amine oxide type surfactant represented by the general formula (I) obtained by the production method of the present invention has a structure corresponding to the starting amine. Therefore, R ¹ in the formula is a linear or branched alkyl or alkenyl group having 8 to 22 carbon atoms which may contain an ester bond, an amide bond or an ether bond, and preferably has 1 carbon atom.
6-22 linear or branched alkyl or alkenyl groups. When R ¹ contains an ester bond, an amide bond or an ether bond, its bonding position is not particularly limited.

[0025]

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 In a reactor equipped with a turbine type stirring blade shown in FIG.
57.1% hydrogen peroxide 107.1 g, ion-exchanged water 566.6
g and 1.1 g of citric acid were charged, and the temperature was raised to 80 ° C.
At the same temperature, stearyl dimethylamine 316.2g
It dripped over time. During the dropping, gelation of the reaction mixture was not observed. After the completion of dropping, the mixture was aged at 80 ° C. for 3 hours to prepare a 35% stearyldimethylamine oxide aqueous solution 9
90 g was obtained (reaction rate 99.7%). The product contained 0.1% by weight of unreacted amine, and the hue was APHA15.

Example 2 In a reactor equipped with a turbine type stirring blade shown in FIG.
57.1% hydrogen peroxide 107.1 g, ion-exchanged water 566.6
g and 1.1 g of citric acid were charged, and the temperature was raised to 80 ° C.
At the same temperature, while blowing 4 liters of carbon dioxide over 2 hours, 316.2 g of stearyldimethylamine was added dropwise over 3 hours. During the dropping, gelation of the reaction mixture was not observed. After the completion of dropping, the mixture was aged at 80 ° C. for 3 hours to prepare a 35% stearyldimethylamine oxide aqueous solution 9
90 g was obtained (reaction rate 99.6%). The product contained 0.1% by weight of unreacted amine, and the hue was APHA5.

Example 3 566.6 g of ion-exchanged water and 1.1 g of citric acid were charged into a reactor equipped with a turbine-type stirring blade shown in FIG. 2, and the temperature was raised to 80.degree. 35% hydrogen peroxide 1 at the same temperature
07.1 g and stearyl dimethylamine 316.2 g were dripped over 14 hours. During the dropping, gelation of the reaction mixture was not observed. After completion of the dropping, the mixture was aged at 80 ° C. for 3 hours to obtain 990 g of a 35% stearyldimethylamine oxide aqueous solution (reaction rate 99.2%). The product contained 0.3% by weight of unreacted amine and had a hue of APHA20.
Met.

Example 4 566.6 g of ion-exchanged water and 1.1 g of citric acid were charged into a reactor equipped with a turbine-type stirring blade shown in FIG. 2, and the temperature was raised to 80 ° C. While blowing 4 liters of carbon dioxide at the same temperature for 2 hours, 35% hydrogen peroxide 107.1 g and stearyl dimethylamine 316.2 g
Was added dropwise over 5 hours. During the dropping, gelation of the reaction mixture was not observed. After the completion of dropping, the mixture was aged at 80 ° C. for 3 hours to obtain 990 g of a 35% stearyldimethylamine oxide aqueous solution (reaction rate 99.7%). The product contained 0.1% by weight of unreacted amine, and the hue was APHA5.

Comparative Example 1 Stearyl dimethylamine 316.2 g and deionized water 5 were placed in a reactor equipped with a turbine type stirring blade shown in FIG.
66.6 g and 1.1 g of citric acid were charged and the temperature was raised to 80 ° C. At the same temperature, 107.1 g of 35% hydrogen peroxide was added to 6
It dripped over time. The reaction liquid became pale white after 2.5 hours from the start of the dropping, and gelled after 3 hours, and the turbine-type stirring blade could hardly stir. After that, the dropping of hydrogen peroxide was continued and the dropping was finished after 6 hours, but there was no change in the gelation state. Then, when it was left at 80 ° C., the gel gradually began to dissolve from the outside of the flask after 2 hours, and became a colorless and transparent aqueous solution after 3 hours. Then 80
The mixture was aged at ℃ for 3 hours to obtain 990 g of 35% stearyl dimethylamine oxide aqueous solution (reaction rate 94.4).
%). The product contained 1.8% by weight of unreacted amine, and the hue was APHA70.

[0031]

According to the production method of the present invention, the reaction operation is simple and the reaction is smooth. Thereby, a high quality amine oxide type surfactant can be stably supplied.

[Brief description of drawings]

FIG. 1 is a diagram for explaining changes in the concentration and state of raw materials and products in the process of producing an amine oxide type surfactant.

FIG. 2 is a schematic view of a reactor equipped with a turbine-type stirring blade used for producing an amine oxide-type surfactant.

─────────────────────────────────────────────────── ─── Continuation of front page (56) References JP-A-56-61349 (JP, A) JP-B 41-9294 (JP, B1) JP-B 57-47182 (JP, B1) (58) Field (Int.Cl. ⁷ , DB name) C07C 291/04 B01F 17/16

Claims (7)

(57) [Claims] 1. The following general formula (I): [In the formula, R ¹ represents a linear or branched alkyl or alkenyl group having 8 to 22 carbon atoms, which may include an ester bond, an amide bond, or an ether bond, and R ² represents 2 to 6 carbon atoms. Is a linear or branched alkylene group, R ³ and R ⁴ are each an alkyl group having 1 to 4 carbon atoms or a hydroxyalkyl group, and A is —O—, —C (═O) NH— or -NHC (= O)-is shown and n shows the number of 0-10] in the manufacturing method of the amine oxide type surfactant represented by the following general formula (II): [Wherein R ^{1 to} R ⁴ , A and n have the same meaning as described above] and hydrogen peroxide are reacted in an aqueous solvent, the concentration of the amine in the reaction system is 5% by weight. A method for producing an amine oxide type surfactant characterized by the following: 2. R ¹ in the general formula (I) is a linear or branched alkyl or alkenyl group having 16 to 22 carbon atoms which may contain an ester bond, an amide bond or an ether bond. A method for producing the amine oxide type surfactant described. 3. The aqueous solvent is water or water and ethanol,
The method for producing an amine oxide type surfactant according to claim 2, which is a mixture with isopropanol, ethylene glycol or propylene glycol. 4. The method for producing an amine oxide type surfactant according to claim 1, wherein the amine represented by the general formula (II) is added to hydrogen peroxide. 5. The method for producing an amine oxide type surfactant according to claim 4, wherein the amine represented by the general formula (II) is added in the presence of carbon dioxide. 6. The method for producing an amine oxide type surfactant according to claim 1, wherein hydrogen peroxide and the amine represented by the general formula (II) are added at the same time. 7. The method for producing an amine oxide type surfactant according to claim 6, wherein the amine represented by the general formula (II) is added in the presence of carbon dioxide.