JPH06256276A - Production of n-long-chain acylamino acid salt - Google Patents

Abstract

PURPOSE:To simply obtain an N-long-chain acylamino acid salt capable of manifesting excellent surface-active and antimicrobial actions at a low cost. CONSTITUTION:This method for producing an N-long-chain acylamino acid salt is characterized by reacting an amino acid salt with a fatty acid halide at 40-60 deg.C maximum reactional temperature in a tubular type reactor having the mixing function in a method for producing the N-long-chain acylamino acid salt having the first step for reacting an amino acid with an alkaline substance and providing the amino acid salt and the second step for reacting the resultant amino acid salt with the fatty acid halide.

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 N-long chain acylamino acid salt, and more particularly, to a highly pure N-long chain acylamino acid salt which exhibits excellent surfactant activity and antibacterial activity. It relates to a method of manufacturing at low cost.

[0002]

BACKGROUND OF THE INVENTION Various inorganic and organic salts of N-long-chain acylamino acids have excellent surface-active effects, antibacterial effects, etc. Applied to various fields.

Conventionally, N-long-chain acylamino acids have been prepared by reacting a fatty acid halide with an alkaline aqueous solution of amino acids, which is obtained by the so-called Schotten-Baumann method, after adjusting the pH of the N-long-chain acylamino acid salt solution to 1 to 5. It was generally produced by crystallization separation.

However, in the above reaction, the viscosity of the reaction system remarkably increases with the progress of the acylation reaction, and
Crystals may precipitate depending on the type of salt. This increase in viscosity and precipitation of crystals deteriorates the stirring efficiency in the system, and the acylation ratio (N with respect to the amount of fatty acid halide used in the reaction)
-The ratio of fatty acid halides converted into long-chain acylamino acid salts) is decreased. Increasing the reaction temperature lowers the viscosity of the system and also suppresses the precipitation of salts, but in this case, the fatty acid halide reacts with water or alkali to form a fatty acid, and the acylation The rate drops. When the Schotten-Baumann reaction is carried out in an ordinary stirring tank, the reaction system does not become heterogeneous, and further, the temperature of the reaction system does not rise too much due to the heat of reaction, so that the fatty acid halide is added to the alkaline aqueous solution of the amino acid. Since it is necessary to gradually drip, the productivity deteriorates.

On the other hand, JP-B-46-8685, JP-B-51-38681 and the like improve the conventional method by reacting an amino acid in a hydrophilic organic solvent with a fatty acid halide in the presence of an alkaline substance. Is disclosed. According to this method, the solubility of the fatty acid halide in the reaction solvent is improved, so that the acylation rate can be significantly improved.

However, even by the above method, the solubility of the N-long chain acylamino acid salt in the reaction solvent is not improved, so that the reaction system is in a slurry state and cannot be sufficiently stirred. In order to avoid this, when an organic solvent is used, a step of removing the organic solvent is required, which increases the equipment cost.

Therefore, there has been a demand for the development of a method for producing a high-purity N-long-chain acylamino acid salt with a high acylation rate simply and inexpensively.

[0008]

Means for Solving the Problems As a result of intensive studies in view of such circumstances, the present inventors have conducted a reaction between an amino acid salt and a fatty acid halide in a tubular reactor having a mixing function under specific temperature conditions. Then, it was found that the acylation rate was dramatically improved, and a high-purity N-long chain acylamino acid salt could be easily obtained, and the present invention was completed.

That is, the present invention is a process for producing an N-long chain acylamino acid salt having a first step of reacting an amino acid with an alkaline substance to obtain an amino acid salt and a second step of reacting the amino acid salt with a fatty acid halide. In the method, the amino acid salt and the fatty acid halide are mixed at a maximum reaction temperature of 40 to 60 ° C. in a tubular reactor having a mixing function,
The present invention provides a method for producing an N-long chain acylamino acid salt, which comprises reacting.

The amino acids used in the present invention are naturally
Alternatively, any of those obtained by synthesis may be used,
Examples thereof include glycine, β-alanine, N-methyl-β-alanine and the like.

Examples of the alkaline substance used in the present invention include inorganic bases such as sodium hydroxide, potassium hydroxide, calcium hydroxide and barium hydroxide, and organic bases such as triethylamine and pyridine.

The fatty acid halide used in the present invention is a saturated or unsaturated one having 6 to 22 carbon atoms, and for example, a fatty acid halide having a single composition such as lauroyl halide, palmitoyl halide, stearoyl halide and oleoyl halide. And mixed fatty acid halides such as coconut oil fatty acid halides and beef tallow fatty acid halides.

The tubular reactor having a mixing function used in the present invention includes (a) a static mixer, (b) a line mixer, (c) a vibrating liquid mixing device, and (d) a loop reactor. Etc. Since any of the reactors has a large portion having a high mixing action in the reactor, it is possible to sufficiently mix even a highly viscous liquid, and a large heat transfer area can be taken for the reactor. The heat can be effectively removed. The above reactors will be described below.

(A) Static Mixer Although it does not have a mechanically movable part, it is possible to mix fluids over a wide range of Reynolds numbers by the construction of a fluid passage consisting of a large number of elements intersecting with each other. , For example, static mixer [made by Noritake Co., Ltd.]
Is mentioned.

(B) Line Mixer A liquid that flows in the pipeline can be efficiently mixed by a stirring blade provided in the pipeline. For example, a pipeline homomixer [made by Tokushu Kika Kogyo Co., Ltd.] is available. Can be mentioned.

(C) Vibratory Liquid Mixing Device This is a device which can efficiently mix the liquid passing through the inside of the pipe by vibrating the stirring plate provided inside the pipe. Co., Ltd.].

(D) Loop type reactor A liquid can be efficiently mixed by providing a circulation path in the pipe and allowing the liquid to circulate in the circulation path at a high speed.

In the first step of reacting the amino acid with an alkaline substance of the present invention to obtain an amino acid salt, the reaction molar ratio is 1.5 to 2.
It is preferably 0 equivalent. The above reaction is preferably carried out at room temperature and atmospheric pressure, and the concentration of the amino acid salt in the system after completion of the reaction is not particularly limited, but is preferably 10 to 30% by weight.

In the second step (acylation reaction step) of reacting the amino acid salt of the present invention with a fatty acid halide to obtain an N-long chain acylamino acid salt, the maximum temperature (maximum reaction temperature) during the reaction is 40 to 60 ° C, preferably 45-5
Set to 5 ° C. Here, the maximum reaction temperature refers to the maximum temperature of the reaction system in the tubular reactor. If the maximum reaction temperature is lower than 40 ° C, the acylation rate will decrease due to the remarkable increase in viscosity, while
If the temperature exceeds 0 ° C, the reaction between the fatty acid halide and water or alkali proceeds to produce a large amount of fatty acid, and thus the acylation rate similarly decreases.

The pressure during the above reaction is preferably normal pressure.

A solvent is used in order to suppress the non-uniformity of the system due to thickening during the reaction. In this case, the solvent is preferably water because it is necessary to remove the solvent after the above reaction.

The reaction molar ratio is preferably 1 to 2 equivalents of amino acid salt to 1 equivalent of fatty acid halide. When the amount of amino acid salt is less than 1 equivalent, the acylation rate is lowered (9
On the other hand, when it exceeds 2 equivalents, a large amount of unreacted amino acid salt remains in the system after completion of the reaction.

If no heat is removed in the second step, the temperature of the reaction system rises by 35 to 65 ° C. That is, since the reaction in the second step of the present invention is an exothermic reaction and the viscosity increases as the reaction progresses as described above, the tubular reactor having the mixing function is preferably used.

[0024]

Industrial Applicability According to the production method of the present invention, a high-purity N-long-chain acylamino acid salt that exhibits excellent surfactant activity, antibacterial activity, etc. can be obtained simply and inexpensively.

[0025]

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited thereto.

Example 1 A 17.3 wt% β-alanine aqueous solution was treated with β-alanine:
A 48 wt% potassium hydroxide aqueous solution was added so that the potassium hydroxide had a molar ratio of 1.1: 2.1 to obtain a β-alanine potassium aqueous solution. This β-alanine potassium aqueous solution (25 ° C.) was added dropwise at a rate of 185.7 g / min, and lauric chloride (25 ° C.) was supplied at a rate of 50 g / min.
In each case, a static mixer (manufactured by Noritake Co., Ltd., number of elements: 17, inner diameter: 0.34)
cm, length 10 cm] and allowed to react at a maximum reaction temperature of 50 ° C. and atmospheric pressure to obtain an aqueous solution containing a reaction product. The concentration of N-lauroyl-β-alanine potassium salt in the reaction product aqueous solution was 28% by weight, and the acylation rate was 94%. The composition of organic substances in the reaction product was 94% by weight of N-lauroyl-β-alanine potassium salt, 2% by weight of potassium laurate, and 4% by weight.

Example 2 An aqueous β-alanine potassium solution (25 ° C.) obtained by the same method as in Example 1 was added at a dropping rate of 3.7 kg / min, and lauric chloride (25 ° C.) was supplied at a rate of 1.0 kg / min. Vibro mixer [manufactured by Cryogenic Industry Co., Ltd., caliber 1.5cm, length 10cm, frequency 25H]
z] and reacted at a maximum reaction temperature of 53 ° C. under normal pressure to obtain an aqueous solution containing a reaction product. The concentration of N-lauroyl-β-alanine potassium salt in the aqueous reaction product solution was 2
It was 8% by weight and the acylation rate was 93.5%. The composition of the organic matter in the reaction product is N-lauroyl-
β-alanine potassium salt was 93.5% by weight, potassium lauric acid salt was 3% by weight, and other was 4.5% by weight.

Comparative Example 1 Using a 3 liter glass round bottom flask, 212.6 g of β-alanine was dissolved in 1021.5 g of water, and 4
522.3 g of 8% potassium hydroxide aqueous solution was added to obtain a β-alanine potassium aqueous solution. The temperature of this aqueous solution is 2
It was 5 ° C. Then the blade diameter is 10 cm and the blade height is 2.5 cm.
471.7 g of lauric acid chloride was added dropwise over about 1.5 hours with stirring using a flat blade at 400 rpm to obtain 2228 g of an aqueous solution containing N-lauroyl-β-alanine potassium salt. The temperature of the reaction solution at the end of dropping was 60 ° C. N-lauroyl-β-in this aqueous solution
The concentration of alanine potassium salt was 27.2% by weight, and the acylation rate was 90%. The composition of the organic substances in the reaction product is 90% by weight of N-lauroyl-β-alanine potassium salt, 5% by weight of potassium laurate and other 5
% By weight.

The reaction conditions and results of Examples 1 and 2 and Comparative Example 1 described above are summarized in Table 1 below.

[0030]

[Table 1]

As is clear from the results shown in Table 1, in both Examples 1 and 2, the acylation rate was higher than that of Comparative Example 1, and the productivity per liter and per minute was higher. It turns out that it is remarkably excellent.

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[Procedure amendment]

[Submission date] April 2, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0004

[Correction method] Change

[Correction content]

However, in the above reaction, the viscosity of the reaction system remarkably increases with the progress of the acylation reaction, and
Crystals may precipitate depending on the type of salt. This increase in viscosity and precipitation of crystals deteriorates the stirring efficiency in the system, and the acylation ratio (N with respect to the amount of fatty acid halide used in the reaction)
-The ratio of fatty acid halides converted into long-chain acylamino acid salts) is decreased. Increasing the reaction temperature lowers the viscosity of the system and also suppresses the precipitation of salts, but in this case, the fatty acid halide reacts with water or alkali to form a fatty acid, and the acylation The rate drops. When the Schotten-Baumann reaction is carried out in an ordinary stirring tank, the reaction system does not become heterogeneous, and further, the temperature of the reaction system does not rise too much due to the heat of reaction, so that the fatty acid halide is added to the alkaline aqueous solution of the amino acid. Since it is necessary to gradually drip, the productivity decreases.

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0008

[Correction method] Change

[Correction content]

[0008]

Means for Solving the Problems As a result of intensive studies in view of such circumstances, the present inventors have conducted a reaction between an amino acid salt and a fatty acid halide in a tubular reactor having a mixing function under specific temperature conditions. Then, they have found that the N-long chain acylamino acid salt having a high acylation rate and high productivity and high purity can be easily obtained, and thus completed the present invention.

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0026

[Correction method] Change

[Correction content]

Example 1 A 17.3 wt% β-alanine aqueous solution was treated with β-alanine:
A 48 wt% potassium hydroxide aqueous solution was added so that the potassium hydroxide had a molar ratio of 1.1: 2.1 to obtain a β-alanine potassium aqueous solution. This β-alanine potassium aqueous solution (25 ° C) was supplied at a rate of 185.7 g / min, and lauric chloride (25 ° C) was supplied at a rate of 50 g / m.
Each of the static mixers is a static mixer (manufactured by Noritake Co., Ltd., with 17 elements and an inner diameter of 0.34).
cm, length 10 cm], the maximum reaction temperature is 50 ° C.,
The reaction was carried out under normal pressure to obtain an aqueous solution containing the reaction product.
The concentration of N-lauroyl-β-alanine potassium salt in the reaction product aqueous solution was 28% by weight, and the acylation rate was 94.
%Met. The composition of the organic matter in the reaction product is N
Lauroyl-β-alanine potassium salt 94% by weight, potassium laurate salt 2% by weight, and other 4% by weight.

[Procedure amendment 4]

[Document name to be amended] Statement

[Name of item to be corrected] 0027

[Correction method] Change

[Correction content]

Example 2 An aqueous β-alanine potassium solution (25 ° C.) obtained by the same method as in Example 1 was supplied at a rate of 3.7 kg / min, and lauric chloride (25 ° C.) was supplied at a rate of 1.0 kg / min.
In each case, a vibro mixer [manufactured by Cryogenic Industry Co., Ltd., caliber 1.5 cm, length 10 cm,
At a frequency of 25 Hz] and reacted at a maximum reaction temperature of 53 ° C. under normal pressure to obtain an aqueous solution containing a reaction product. The concentration of N-lauroyl-β-alanine potassium salt in the reaction product aqueous solution was 28% by weight, and the acylation rate was 93.5%.
Met. The composition of the organic matter in the reaction product is N-
Lauroyl-β-alanine potassium salt 93.5% by weight,
Lauric acid potassium salt was 3% by weight and the other was 4.5% by weight.

[Procedure Amendment 5]

[Document name to be amended] Statement

[Name of item to be corrected] 0030

[Correction method] Change

[Correction content]

[0030]

[Table 1]

Claims (1)

[Claims] 1. A method for producing an N-long chain acylamino acid salt, which comprises a first step of reacting an amino acid with an alkaline substance to obtain an amino acid salt and a second step of reacting the amino acid salt with a fatty acid halide. A method for producing an N-long chain acylamino acid salt, which comprises reacting a salt and a fatty acid halide in a tubular reactor having a mixing function at a maximum reaction temperature of 40 to 60 ° C.