JP6834376B2 - Surfactant composition - Google Patents

Description

The present invention relates to a surfactant composition, for example, a liquid surfactant composition such as an aqueous solution.

Acylamino acid-based surfactants have an excellent feeling of use that they are less irritating to the skin and hair and have high foaming properties. Therefore, they are the main components of body cleansers such as scalp, hair and body cleansers, or It is widely used as an auxiliary ingredient. Among these acylamino acid-based surfactants, the taurine salt of N-acylmethyltaurine has excellent foam durability, and when used in a hair shampoo, it gives the hair after washing a cohesiveness and has a high moisturizing effect. , Is known to be particularly useful.
Formulations such as body cleansers containing the taurine salt of N-acylmethyl taurine are generally blended in combination with a plurality of surfactants in consideration of foam quality and usability, and then, if necessary, It is manufactured by further blending a viscosity modifier, a hydrotrope, a chelating agent, a preservative, and a fragrance according to the taste, which contribute to stability.

At the stage of blending the taurine salt of N-acylmethyl taurine with multiple surfactants, the active ingredient of the taurine salt of N-acylmethyl taurine is used for reasons such as handleability, production efficiency, and transportation cost when preparing the preparation. It is desirable to obtain a surfactant composition having a concentration as high as possible.
However, in a surfactant composition containing a taurine salt of N-acylmethyl taurine, usually, when the concentration of the active ingredient exceeds 15% by mass, the taurine salt of N-acylmethyl taurine is precipitated even at room temperature of about 20 ° C. , Solidification or separation of the aqueous solution may occur, and the transparency of the aqueous solution may be lost. Further, when solidified at a low temperature such as in winter, the transparency of the aqueous solution may be lost due to the solidification or separation of the aqueous solution even when the temperature is returned to room temperature. In such a case, there is a problem that operations such as heating and shaking are required at the time of handling such as blending in a preparation such as a body cleanser, which hinders workability and handleability.

It is presumed that such a problem is derived from a subcomponent generated during the reaction of the taurine salt of N-acylmethyltaurine. That is, the taurine salt of N-acylmethyl taurine is generally produced by exchanging a sodium salt or the like of N-acylmethyl taurine with a taurine salt, as shown in Patent Documents 1 and 2. At this time, it is presumed that the above-mentioned problems occur due to salting out due to the coexistence of sodium chloride produced as a by-product.
The reason why sodium chloride coexists in this way is that, as described in Examples of Patent Document 1, the N-acylmethyl taurine salt-containing product as a raw material is derived from the fatty acid chloride used as an acylating agent. It is conceivable that sodium chloride is contained in the above, or sodium chloride is produced as a by-product when hydrochloric acid is used during the reaction step as described in Examples of Patent Document 2.
However, regarding the surfactant composition containing the taurine salt of N-acylmethyltaurine, no proposal has been made to prevent the solidification or separation of the aqueous solution at room temperature, and the above-mentioned problems have not yet been solved.

On the other hand, with respect to surfactant compositions other than the taurine salt of N-acylmethyl taurine used in liquid clothing cleaning agents and liquid tableware cleaning agents, the purpose is to suppress solidification and separation of the aqueous solution at room temperature. Various technologies have been developed.
For example, Patent Document 3 proposes a composition containing an anionic surfactant, a Quillaia extract, and a polyol such as 1,3-butylene glycol. Further, Patent Document 4 proposes a composition containing an amine oxide and polyethylene glycol. Further, Patent Document 5 proposes a composition containing a polyoxyalkylene alkyl ether sulfate ester salt and ethanol. Further, Patent Document 6 proposes a composition containing an α-sulfofatty acid alkyl ester salt and a branched chain alcohol such as 2-ethylhexanol.

However, in the prior art shown in Patent Documents 3 to 6, the taurine salt-containing surfactant composition of N-acylmethyl taurine at room temperature has not yet been sufficient for the purpose of preventing solidification and separation. Specifically, by using a polyol such as 1,3-butylene glycol compounded in Patent Document 3, it is possible to prevent the aqueous solution from solidifying or separating at room temperature of about 20 ° C. depending on the type of polyol. However, when solidified at a low temperature such as in winter, the taurine salt-containing surfactant composition of N-acylmethyl taurine remains in a separated state even when the temperature is returned to room temperature, which leads to improvement in workability and handleability. There wasn't. Further, even if polyethylene glycol, ethanol and branched chain alcohol blended in Patent Documents 4, 5 and 6 were used, solidification and separation of the aqueous solution at room temperature could not be prevented.

Japanese Patent No. 2003-286499 JP-A-2002-1086 Japanese Unexamined Patent Publication No. 2014-136701 Japanese Patent No. 2011-137056 JP-A-2009-114239 Japanese Unexamined Patent Publication No. 2008-9942

An object of the present invention is that in a surfactant composition containing a taurine salt of N-acylmethyl taurine, the taurine salt of N-acylmethyl taurine is difficult to precipitate at room temperature of about 20 ° C. and is transparent and solidifies at a low temperature. However, it is an object of the present invention to provide a surfactant composition having a restoring property which becomes transparent again when the temperature is returned to room temperature.

As a result of diligent studies to solve the above problems, the present inventors have achieved the above object by combining a taurine salt of N-acylmethyl taurine with a specific organic acid.

That is, the present invention, (A) 15 to 35 wt% taurine salt of N--acylmethyltaurine represented by the following general formula (1), 0.5 to 5 mass (B) having 6 or less of dicarboxylic acid carbon The surfactant composition is characterized by having a% content and a sodium chloride content of 2% by mass or less.
R ¹ CON (CH ₃ ) CH ₂ CH ₂ SO ₃ ^- X ⁺ ... (1)
(R ¹ CO is an acyl group having 8 to 24 carbon atoms, X ⁺ is H ₃ N ⁺ CH ₂ CH ₂ SO ₃ ^- M ⁺ , and M ⁺ is an alkali metal ion or organic ammonium.)

The surfactant composition of the present invention is a surfactant composition containing a taurine salt of N-acylmethyl taurine, and is transparent so that the taurine salt of N-acylmethyl taurine does not easily precipitate at room temperature of about 20 ° C. It has the resilience that even if it solidifies at low temperature, it becomes transparent again when it is returned to room temperature. Therefore, according to the present invention, it is not necessary to perform operations such as heating and shaking during handling, and it is possible to obtain an effect that workability and handleability are good.

Hereinafter, embodiments of the present invention will be described.
The surfactant composition of the present invention contains the components (A) and (B) described below.

[(A) component]
The component (A) used in the present invention is a taurine salt of N-acylmethyl taurine represented by the following general formula (1).
R ¹ CON (CH ₃ ) CH ₂ CH ₂ SO ₃ ^- X ⁺ ... (1)

In the formula, R ¹ CO is an acyl group having 8 to 24 carbon atoms, preferably an acyl group having 8 to 18 carbon atoms. Specifically, it is a capriloyl group, a caproyl group, a lauroyl group, a myristoylation group, a palmitoyl group, a stearoyl group, an oleoil group, a behenoyl group, and a mixed acyl group containing two or more of these acyl groups can also be used. .. Examples of the mixed acyl group include a coconut group and a palm kernel oil fatty acid acyl group. The typical content ratio of each acyl group contained in the cocoyl group is C8: C10: C12: C14: C16: C18 = 5: 6: 55: 17: 10: 7 (mass ratio). The typical content ratio of each acyl group contained in the palm kernel oil fatty acid acyl group is C8: C10: C12: C14: C16: C18 = 3: 7: 47: 14: 9: 20 (mass ratio). ..
The acyl group in the component (A) is preferably a capryloyl group, a caproyl group, a lauroyl group, a myristoylation group, an oleoil group, or a cocoyl group, and more preferably a cocoyl group, because it is difficult to precipitate at room temperature.

In the formula, X ⁺ is represented by H ₃ N ⁺ CH ₂ CH ₂ SO ₃ ⁻ M ⁺ . M ⁺ is an alkali metal ion or organic ammonium. Specifically, examples of the alkali metal include sodium, potassium and the like, and examples of the organic ammonium include triethanolamine, arginine, lysine, histidine and the like. M ^{+ in} X ⁺ may be any of the above alkali metal ions or organic ammonium because it is difficult to precipitate at room temperature.

As the component (A), one kind or two or more kinds can be used in the surfactant composition of this invention. The content of the component (A) is 15 to 35% by mass, preferably 18 to 30% by mass, and particularly preferably 20 to 25% by mass in the surfactant composition. If the content is too low, it may be disadvantageous in terms of handleability, production efficiency, transportation cost, etc. when used in a formulation. If the content is too high, solidification or separation of the composition may occur easily at room temperature.

[Component (B)]
The component (B) used in the present invention is a hydroxy acid having 6 or less carbon atoms or a dicarboxylic acid having 6 or less carbon atoms, and a hydroxy acid having 6 or less carbon atoms and a dicarboxylic acid having 6 or less carbon atoms are used in combination. May be good.
Examples of the hydroxy acid having 6 or less carbon atoms include glycolic acid, lactic acid, tartronic acid, glyceric acid, malic acid, tartaric acid, citric acid, isocitric acid, pantoic acid, mevalonic acid, leucic acid and the like. Two or more types can be used.
Examples of the dicarboxylic acid having 6 or less carbon atoms include oxalic acid, malonic acid, succinic acid, glutaric acid and the like, and one or more of them can be used.
If the hydroxy and dicarboxylic acids have too many carbon atoms, they may have low solubility in the composition and may not be suitable for use.
The component (B) may be any hydroxy acid having 6 or less carbon atoms or a dicarboxylic acid having 6 or less carbon atoms because of the difficulty of precipitation at room temperature and the recoverability, but when used in a body cleaning agent. Considering the above, those commonly used in cosmetics, for example, glycolic acid, lactic acid, malic acid, tartaric acid, citric acid, oxalic acid, malonic acid and succinic acid are preferable, and compatibility with surfactants is also preferable. Therefore, lactic acid, citric acid, and malic acid are particularly preferable, and citric acid is most preferable.

The content of the component (B) is 0.1 to 5% by mass, preferably 0.3 to 3% by mass, and particularly preferably 0.5 to 1.5% by mass in the surfactant composition. .. If the content is too low, solidification or separation of the surfactant composition may occur easily at room temperature. If the content is too high, it may be difficult to obtain resilience even when stored at room temperature after solidifying at a low temperature, and it may be difficult for the composition to become transparent.

The surfactant composition of the present invention may contain sodium chloride derived from a by-product generated in the preparation of the taurine salt of N-acylmethyltaurine as the component (A).
In the present invention, the content of sodium chloride is 2% by mass or less, preferably 1.5% by mass or less, and particularly preferably 1% by mass or less. If the content of sodium chloride is too high, solidification or separation of the composition may occur at room temperature. The lower limit of the sodium chloride content is preferably as close to 0% by mass as possible, and particularly preferably 0% by mass.
As a method for adjusting the content of sodium chloride contained in the surfactant composition of the present invention to 2% by mass or less, for example, a reverse osmosis membrane method is used for a product containing a taurine salt of N-acylmethyltaurine. , Electrodialysis method, solvent method, and the like.

The content of sodium chloride contained in the surfactant composition can be measured by, for example, an alcohol insoluble content, and specifically, it can be measured by the following method.
First, the surfactant composition is weighed in an Erlenmeyer flask, isopropyl alcohol is added thereto, and then a reflux cooling device is attached to boil the surfactant composition for 1 hour with occasional shaking on a water bath. At warm time, this is filtered using a glass filter of known weight (1G3), the residue is washed with warm isopropyl alcohol and then dried at 105 ° C. for 2 hours to weigh the glass filter. The alcohol insoluble content is determined by the following formula, and this is used as the sodium chloride content.
Alcohol insoluble content (%) = [(Glass filter weight after measurement-Glass filter weight before measurement) / Sample weight] x 100

The surfactant composition of the present invention can be produced according to a usual method. For example, the N-acylmethyl taurine salt and the taurine salt are reacted in the presence of hydrochloric acid to prepare the taurine salt of N-acylmethyl taurine as the component (A), and the composition is formed by desalting treatment such as a back-penetration membrane method. The content of sodium chloride contained in the product is adjusted to 2% by mass or less. If necessary, in order to adjust the content of the active ingredient (A), it is diluted with purified water or concentrated by a reverse osmosis membrane method or the like. The surfactant composition of the present invention is produced by blending a predetermined amount of the component (B) with the aqueous solution containing the component (A) thus obtained.

The surfactant composition of the present invention contains purified water such as distilled water and ion-exchanged water, and is usually provided in the form of an aqueous solution. Further, the surfactant composition of the present invention may contain an arbitrary component as the case may be.

[Examples 1 and 2, Reference Examples 1 to 8 and Comparative Examples 1 to 11]
Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples.
Surfactant compositions were prepared based on the formulations shown in Tables 1 and 2. The preparation method of each composition is as follows.

(1) Preparation of N-acylmethyltaurine salt-containing aqueous solution Prepared according to the examples of Patent Document 2. That is, 308.7 g (1.05 mol) of a 50 mass% aqueous solution of taurine sodium salt (molecular weight 147) was charged into a 2-liter volume four-necked flask, and 106.5 g (1.05 mol) of 36 mass% hydrochloric acid was charged therein. Was added, and the mixture was stirred at 50 ° C. for 10 minutes. Next, 1329.9 g (1 mol) of a 27 mass% aqueous solution of N-cocoyl methyl taurine sodium salt (molecular weight 358.8) was added, and the mixture was stirred at 50 ° C. for 30 minutes to form a taurine sodium salt of N-cocoyl methyl taurine (general formula (general formula (general formula (general formula)). 1) R ¹ CO is a cocoyl group and M in X is sodium. Active ingredient concentration: 28% by mass) An aqueous solution was obtained. The sodium chloride contained in this aqueous solution was 3.6% by mass.

(2) Adjustment of Active Ingredient (Component (A)) Content and Sodium Chloride Content in N-Acylmethyl Taurine Salt-Containing Aqueous Solution Each surface activity of Examples 1 and 2, Reference Examples 1 to 8 and Comparative Examples 1 to 11 The N-acylmethyl taurine salt-containing aqueous solution (hereinafter, also referred to as component (A) aqueous solution) used in the agent composition is a polyamided sulfone with respect to the taurine sodium salt aqueous solution of N-cocoyl methyl taurine prepared in (1) above. It was obtained by adjusting the contents of sodium taurine and sodium chloride of N-cocoyl methyl taurine by performing desalting treatment by a reverse osmotic membrane method using a membrane. The adjustment method of each example is shown below.

Aqueous solution of component (A) of Reference Examples 1 and 8 500 g of purified water was added to 500 g of a sodium chloride aqueous solution of N-cocoyl methyl taurine having an active component concentration of 28% by mass, and this mixed solution was treated with a reverse osmosis membrane to prepare 500 g of water. When 500 g of purified water was drained and 500 g of purified water was drained again, 500 g of water was drained by reverse osmosis membrane treatment, 500 g of purified water was further added, and 500 g of water was drained by reverse osmosis membrane treatment, the content of sodium chloride was 0.6% by mass. , The content of sodium salt of taurine in N-cocoyl methyl taurine was 27.8% by mass. 38.2 g of water was removed from 500 g of this aqueous solution by back-penetration membrane treatment, and 1.4 g of sodium chloride was added to increase the content of sodium taurine salt of N-cocoyl methyl taurine to 30.0% by mass and the content of sodium chloride. A 0.8% by mass aqueous solution was prepared and used as the component (A) aqueous solution of Reference Examples 1 and 8.

As for the content of the active ingredient, the remaining amount of dryness was measured, the difference between the remaining amount of dryness and the content of sodium chloride was obtained, and this was taken as the content of the active ingredient. Specifically, the method for measuring the remaining amount of dryness is as follows. That is, about 2 g of the sample was weighed in a weighing bottle of known weight, and then allowed to stand in a blower dryer set at 105 ° C. for 2 hours. After allowing to cool in a desiccator containing silica gel for 30 minutes, the mixture was weighed and the remaining amount of drying was determined by the following formula.
Remaining dryness (%) = [(Weighing bottle weight after drying-Weighing bottle weight) / Sample weight] x 100

Aqueous solution of component (A) of Reference Example 2 500 g of purified water was added to 500 g of a sodium chloride aqueous solution of N-cocoyl methyl taurine having an active ingredient concentration of 28% by mass, and this mixed solution was treated with a reverse osmosis membrane to remove 500 g of water. When 500 g of purified water was added again and 500 g of water was removed by reverse osmosis membrane treatment, the content of sodium chloride was 1.1% by mass, and the content of sodium taurine salt of N-cocoyl methyl taurine was 27.9% by mass. there were. Take 100 g of this aqueous solution, add 26.3 g of purified water and 0.6 g of sodium chloride to it, and the content of sodium taurine salt of N-cocoyl methyl taurine is 22.0% by mass, and the content of sodium chloride is 1. A 3% by mass aqueous solution was prepared and used as the component (A) aqueous solution of Reference Example 2.

Aqueous solution of component (A) of Reference Example 3 and Example 1 500 g of purified water was added to 500 g of an aqueous solution of sodium chloride of N-cocoyl methyl taurine having an active ingredient concentration of 28% by mass, and this mixed solution was treated with a reverse osmosis membrane. 500 g of purified water was removed, 500 g of purified water was added again, 500 g of water was removed by reverse osmosis membrane treatment, 500 g of purified water was added again, and 500 g of water was removed by reverse osmosis membrane treatment. The sodium chloride content was 0.6. The content of sodium salt of taurine in N-cocoyl methyl taurine was 27.8% by mass. 37.4 g of water was removed from 500 g of this aqueous solution by back-penetration membrane treatment, 0.5 g of sodium chloride was added, and the content of sodium taurine salt of N-cocoyl methyl taurine was 30.0% by mass and the content of sodium chloride was 0. A 6% by mass aqueous solution was prepared and used as the component (A) aqueous solution of Reference Example 3 and Example 1.

Aqueous solution of component (A) of Reference Examples 4 and 5 500 g of purified water was added to 500 g of a sodium chloride aqueous solution of N-cocoyl methyl taurine having an active component concentration of 28% by mass, and this mixed solution was treated with a back-penetration membrane to prepare 500 g of water. When 500 g of purified water was removed and 500 g of water was removed by back-penetration membrane treatment, the content of sodium chloride was 1.1% by mass, and the content of sodium taurine salt of N-cocoyl methyl taurine was 27.9% by mass. %Met. Take 100 g of this aqueous solution, add 26.7 g of purified water and 0.2 g of sodium chloride to it, and the content of sodium taurine salt of N-cocoyl methyl taurine is 22.0% by mass, and the content of sodium chloride is 1. A 0% by mass aqueous solution was prepared and used as the component (A) aqueous solution of Reference Examples 4 and 5.

Aqueous solution of component (A) of Reference Example 6 500 g of purified water was added to 500 g of a taurine sodium salt aqueous solution of N-cocoyl methyl taurine having an active ingredient concentration of 28% by mass, and this mixed solution was treated with a reverse osmosis membrane to remove 500 g of water. Add 500 g of purified water again, remove 500 g of water by reverse osmosis membrane treatment, add 500 g of purified water again, remove 500 g of water by reverse osmosis membrane treatment, add 500 g of purified water again, and add water by reverse osmosis membrane treatment. When 500 g was removed, the content of sodium chloride was 0.3% by mass, and the content of sodium taurine salt of N-cocoyl methyl taurine was 27.8% by mass. 38.2 g of water was removed from 500 g of this aqueous solution by back-penetration membrane treatment, and 0.9 g of sodium chloride was added to increase the content of sodium taurine salt of N-cocoyl methyl taurine to 30.0% by mass and the content of sodium chloride. A 0.4% by mass aqueous solution was prepared and used as the component (A) aqueous solution of Reference Example 6.

Aqueous solution of component (A) of Example 2 500 g of purified water was added to 500 g of a sodium chloride aqueous solution of N-cocoyl methyl taurine having an active ingredient concentration of 28% by mass, this mixed solution was treated with a reverse osmosis membrane, and 500 g of water was removed. When 500 g of purified water was added again, 500 g of water was removed by reverse osmosis membrane treatment, 500 g of purified water was added again, and 500 g of water was removed by reverse osmosis membrane treatment, the sodium chloride content was 0.6% by mass, N. -The content of sodium taurine salt of cocoyl methyl taurine was 27.8% by mass. Taking 100 g of this aqueous solution, 25.9 g of purified water and 0.4 g of sodium chloride were added thereto, and the content of sodium taurine salt of N-cocoyl methyl taurine was 22.0% by mass, and the content of sodium chloride was 0. An 8% by mass aqueous solution was prepared and used as the component (A) aqueous solution of Example 2.

Aqueous solution of component (A) of Reference Example 7 500 g of purified water was added to 500 g of a sodium chloride aqueous solution of N-cocoyl methyl taurine having an active ingredient concentration of 28% by mass, and this mixed solution was treated with a back-penetration membrane to remove 500 g of water. However, the content of sodium chloride was 2.0% by mass, and the content of sodium taurine salt of N-cocoyl methyl taurine was 27.9% by mass. Take 100 g of this aqueous solution and add 54.6 g of purified water to prepare an aqueous solution containing 18.0% by mass of sodium taurine salt of N-cocoyl methyl taurine and 1.3% by mass of sodium chloride. Then, the component (A) aqueous solution of Reference Example 7 was used.

Aqueous solution of component (A) of Comparative Example 1 500 g of purified water was added to 500 g of a sodium chloride aqueous solution of N-cocoyl methyl taurine having an active ingredient concentration of 28% by mass, and this mixed solution was treated with a reverse osmosis membrane to remove 500 g of water. When 500 g of purified water was added again, 500 g of water was removed by reverse osmosis membrane treatment, 500 g of purified water was added again, and 500 g of water was removed by reverse osmosis membrane treatment, the sodium chloride content was 0.6% by mass, N. -The content of sodium taurine salt of cocoyl methyl taurine was 27.8% by mass. 38.2 g of water was removed from 500 g of this aqueous solution by back-penetration membrane treatment, and 1.4 g of sodium chloride was added to increase the content of sodium taurine salt of N-cocoyl methyl taurine to 30.0% by mass and the content of sodium chloride. A 0.8 mass% aqueous solution was prepared and used as the component (A) aqueous solution of Comparative Example 1.

Aqueous solution of component (A) of Comparative Example 2 500 g of purified water was added to 500 g of an aqueous solution of sodium chloride of N-cocoyl methyl taurine having an active ingredient concentration of 28% by mass, and this mixed solution was treated with a reverse osmosis membrane to remove 500 g of water. When 500 g of purified water was added again and 500 g of water was removed by reverse osmosis membrane treatment, the content of sodium chloride was 1.1% by mass, and the content of sodium taurine salt of N-cocoyl methyl taurine was 27.9% by mass. there were. Take 100 g of this aqueous solution, add 26.3 g of purified water and 0.6 g of sodium chloride to it, and the content of sodium taurine salt of N-cocoyl methyl taurine is 22.0% by mass, and the content of sodium chloride is 1. A 3% by mass aqueous solution was prepared and used as the component (A) aqueous solution of Comparative Example 2.

Aqueous solution of component (A) of Comparative Example 3 500 g of purified water was added to 500 g of an aqueous solution of sodium chloride of N-cocoyl methyl taurine having an active ingredient concentration of 28% by mass, and this mixed solution was treated with a reverse osmosis membrane to remove 500 g of water. When 500 g of purified water was added again, 500 g of water was removed by reverse osmosis membrane treatment, 500 g of purified water was added again, and 500 g of water was removed by reverse osmosis membrane treatment, the sodium chloride content was 0.6% by mass, N. -The content of sodium taurine salt of cocoyl methyl taurine was 27.8% by mass. 152.5 g of water was removed from 500 g of this aqueous solution by back-penetration membrane treatment, and 0.4 g of sodium chloride was added to increase the content of sodium taurine salt of N-cocoyl methyl taurine to 40.0% by mass and the content of sodium chloride. An aqueous solution of 0.5% by mass was prepared and used as an aqueous solution of component (A) of Comparative Example 3.

Aqueous solution of component (A) of Comparative Examples 4 and 7 to 11 500 g of purified water was added to 500 g of a sodium chloride aqueous solution of N-cocoyl methyl taurine having an active ingredient concentration of 28% by mass, and this mixed solution was treated with a reverse osmosis membrane. , 500 g of water was drained, 500 g of purified water was added again, 500 g of water was drained by reverse osmosis membrane treatment, 500 g of purified water was further added, and 500 g of water was drained by reverse osmosis membrane treatment. The sodium chloride content was 0. The content of sodium taurine salt of N-cocoyl methyl taurine was .6% by mass and was 27.8% by mass. Taking 100 g of this aqueous solution, 25.9 g of purified water and 0.4 g of sodium chloride were added thereto, and the content of sodium taurine salt of N-cocoyl methyl taurine was 22.0% by mass, and the content of sodium chloride was 0. An 8% by mass aqueous solution was prepared and used as an aqueous solution of component (A) of Comparative Examples 4 and 7-11.

Aqueous solution of component (A) of Comparative Example 5 500 g of purified water was added to 500 g of a sodium chloride aqueous solution of N-cocoyl methyl taurine having an active component concentration of 28% by mass, and this mixed solution was treated with a back-penetration membrane to remove 500 g of water. However, the content of sodium chloride was 2.0% by mass, and the content of sodium taurine salt of N-cocoyl methyl taurine was 27.9% by mass. Take 100 g of this aqueous solution, add 25.6 g of purified water and 1.2 g of sodium chloride to it, and the content of sodium taurine salt of N-cocoyl methyl taurine is 22.0% by mass, and the content of sodium chloride is 2. A 5% by mass aqueous solution was prepared and used as the component (A) aqueous solution of Comparative Example 5.

Aqueous solution of component (A) of Comparative Example 6 500 g of purified water was added to 500 g of a sodium chloride aqueous solution of N-cocoyl methyl taurine having an active component concentration of 28% by mass, and this mixed solution was treated with a back-penetration membrane to remove 500 g of water. However, the content of sodium chloride was 2.0% by mass, and the content of sodium taurine salt of N-cocoyl methyl taurine was 27.9% by mass. 38.1 g of water was removed from 500 g of this aqueous solution by back-penetration membrane treatment, and 2.8 g of sodium chloride was added to increase the content of sodium chloride in N-cocoyl methyl taurine to 30.0% by mass and the content of sodium chloride. A 2.5% by mass aqueous solution was prepared and used as the component (A) aqueous solution of Comparative Example 6.

(3) Formulation of component (B) Each organic acid of component (B) is blended with the aqueous solution obtained in (2) above so as to have a required content in each composition, and Examples 1 and 2 and The surfactant compositions of Reference Examples 1 to 8 and Comparative Examples 1 to 11 were prepared.

Next, the appearance of each composition at room temperature and the resilience from low temperature were evaluated by the following methods. The results are shown in Tables 1 and 2. The numerical values in the table indicate the mass% of the pure content.

A. Appearance at Room Temperature 100 g of each composition was transparently and uniformly dissolved at 60 ° C., then placed in a glass bottle having a capacity of 200 ml, and stored in a constant temperature bath at 20 ° C. for 24 hours with the lid closed. The appearance of each composition after 24 hours was visually evaluated according to the following two-step criteria.

(Appearance at room temperature)
(Score): (Evaluation)
◯: The composition is transparent.
X: Separation or solidification is observed in the composition.

B. Restorability from low-temperature solidification 100 g of each composition was transparently and uniformly dissolved at 60 ° C., then placed in a glass bottle having a capacity of 200 ml and stored in a constant temperature bath at −5 ° C. for 24 hours for solidification. Then, it was stored in a constant temperature bath at 20 ° C. for 24 hours. The appearance of each composition in a constant temperature bath at 20 ° C. after 24 hours was visually evaluated according to the following two-step criteria.

(Restorability from low temperature solidification)
(Score): (Evaluation)
◯: The composition is transparent.
X: Separation or solidification is observed in the composition.

From Examples 1 and 2 , the surfactant composition of the present invention had a transparent appearance at room temperature and good resilience from low-temperature solidification in any of the compositions.

On the other hand, in Comparative Examples 1 to 11, sufficient effects were not obtained.
In Comparative Examples 1 and 2, since the hydroxy acid or dicarboxylic acid of the component (B) is not contained, the substance (B) is not transparent at room temperature and is not recoverable from low temperature solidification.
In Comparative Example 3, since the content of the taurine salt of N-acylmethyltaurine of the component (A) exceeds 35% by mass, it does not become transparent at room temperature, and restoration from low temperature solidification is not observed.
In Comparative Example 4, since the content of the hydroxy acid or dicarboxylic acid of the component (B) exceeds 5% by mass, it is transparent at room temperature, but no resilience from low temperature solidification is observed.
In Comparative Examples 5 and 6, since the content of sodium chloride exceeds 2% by mass, it does not become transparent at room temperature, and recovery from low temperature solidification is not observed.
In Comparative Example 7, since 1,3-butylene glycol is used instead of the hydroxy acid or dicarboxylic acid of the component (B), it is transparent at room temperature, but no resilience from low temperature solidification is observed.
In Comparative Example 8, since glycerin is used instead of the hydroxy acid or dicarboxylic acid of the component (B), it does not become transparent at room temperature, and recovery from low temperature solidification is not observed.
In Comparative Example 9, since polyethylene glycol is used instead of the hydroxy acid or dicarboxylic acid of the component (B), it does not become transparent at room temperature, and recovery from low temperature solidification is not observed.
In Comparative Example 10, since ethanol is used instead of the hydroxy acid or dicarboxylic acid of the component (B), it does not become transparent at room temperature, and recovery from low temperature solidification is not observed.
In Comparative Example 11, since 2-ethylhexanol is used in place of the hydroxy acid or dicarboxylic acid of the component (B), it does not become transparent at room temperature, and recovery from low temperature solidification is not observed.

The surfactant composition of the present invention can be suitably used as a raw material for preparations such as cosmetics and pharmaceuticals, and can be used as a main component or an auxiliary component of a body cleanser such as a scalp, hair or body cleanser, for example. It can be used.

Claims (1)

(A) 15 to 35 wt% taurine salt of N--acylmethyltaurine represented by the following general formula (1) contains 0.5 to 5 wt% of (B) having 6 or less of dicarboxylic acid carbon, chloride A surfactant composition having a sodium content of 2% by mass or less.
R ¹ CON (CH ₃ ) CH ₂ CH ₂ SO ₃ ^- X ⁺ ... (1)
(R ¹ CO is an acyl group having 8 to 24 carbon atoms, X ⁺ is H ₃ N ⁺ CH ₂ CH ₂ SO ₃ ^- M ⁺ , and M ⁺ is an alkali metal ion or organic ammonium.)