JP6940328B2 - Liquid cleaning composition - Google Patents

Description

The present invention relates to a liquid cleaning composition.

Various forms of products are offered as skin cleansers. For example, liquid cleaning agents, cream-like cleaning agents, solid-type cleaning agents, powder or granular cleaning agents, and the like are typical. In recent years, the amount of liquid skin cleansers used has been increasing due to their ease of use.
On the other hand, there are various types of surfactants used in liquid skin cleansers. Among them, acylglutamic acid is attracting attention as a surfactant to be blended. Acylglutamate is a highly safe surfactant with excellent detergency, and has been used in liquid and powder type facial cleansers for sensitive skin, body cleansers, shampoos, etc. (Patent Document 1, Patent). Document 2, Patent Document 3). The liquid cleaning agent is often given an appropriate viscosity by adding a thickener in order to make it easy to handle when it is picked up from the container and to prevent it from dripping during use. However, as compared with general anionic surfactants such as sodium laureth sulfate, acylglutamic acid salt is less likely to thicken the liquid cleaning agent when blended in a large amount or when combined with other surfactants. Are known. The hydrophilic group present in the chemical structure of the acyl glutamate is glutamic acid, and under weakly acidic conditions with good foaming, one to two of the two carboxyl groups are present in an acidic state and the critical filling parameter is low. It is presumed that this affects the difficulty of thickening. A technique for thickening by using a polymer-based thickener and a nonionic surfactant such as fatty acid alkanolamide and polyethylene glycol fatty acid ester in combination is disclosed (for example, Patent Document 4), but the cleaning agent is increased. Even if it becomes sticky, the thickener formulated for that purpose tends to give a slimy feeling of use, and the refreshing and good feeling of use peculiar to acylglutamate is often impaired.
In addition, in the formulation design, in order to improve foaming, fineness of foam, and feel of the skin after rinsing, not only medium-chain acylglutamic acid but also long-chain acylglutamic acid having an acyl group such as stearic acid or palmitic acid is used. It is known that it needs to be blended. However, when the acyl group has a long chain, the solubility is lowered and precipitation is caused, so that there is a problem that the transparency of the liquid cleaning agent is also lowered. At this time, it is known that if an alkanolamine salt such as triethanolamine is used as the salt, the solubility in water is improved, but in terms of foam fineness and safety, alkali metal salts such as sodium and potassium are used. It is desirable to use, and designing a formulation using only alkanolamine salts has a problem when foam quality and safety are emphasized.
Furthermore, acyl glutamate has a lower solubility in water in a weakly acidic region of less than pH 7, which is usually preferable as a cosmetic used for skin, as compared with a higher pH region, and depending on the composition of the acyl group. It is known that the aqueous solution becomes cloudy or precipitates. Therefore, it has been difficult to prepare a highly transparent preparation having a preferable viscosity under weak acidity with a liquid cleaning agent containing acylglutamic acid salt. In Patent Document 1, although a transparent liquid cleaning agent is partially obtained under weakly acidic conditions, there are problems in terms of usability and safety such as foam quality. Therefore, when acylglutamic acid salt is blended in a relatively large amount, it is generally a powder or granular preparation disclosed in Patent Documents 2 and 3. A cream-like cleaning agent containing acylglutamic acid as a main component is known, which is obtained by precipitating and thickening acylglutamic acid, and in the present invention in which acylglutamic acid is dissolved and thickened. It is different from the liquid cleaning agent.

As a technique for clear liquid skin cleansing agents, as a cleansing ingredient, only the higher fatty acid L-arginine salt is contained in an amount of 10 to 30% by weight, polyhydric alcohol is contained in an amount of 20 to 60% by weight, and ascorbic acid or a salt thereof is used. The technology of the transparent liquid cleaning agent contained (Patent Document 5) is open to the public.

Japanese Unexamined Patent Publication No. 2002-212599 Japanese Patent No. 5959232 Japanese Unexamined Patent Publication No. 2009-051945 Japanese Unexamined Patent Publication No. 06-158089 Japanese Unexamined Patent Publication No. 2007-07296

The present inventor is conducting research and development for providing a liquid cleansing composition containing N-acylglutamate, which is mainly intended for skin cleansing. Then, many combinations of liquid cleaning agents containing N-acylglutamate and other surfactants have been examined. As a result, by adding an acidic substance to the composition containing N-acylglutamate, an amine oxide amphoteric surfactant and water to lower the pH, the viscosity of the composition can be increased without adding a thickener. I found that it can be enhanced. Furthermore, it has been found that the thickening composition obtained by the above step has a preferable viscosity as a liquid composition for washing skin, scalp and hair. Further, it was found that it has transparency, and the present invention was completed.
That is, the present invention provides a liquid cleaning composition containing N-acylglutamate, an amine oxide amphoteric surfactant and water, and having a preferable viscosity as a skin, scalp and hair cleaning composition under weak acidity. It is an object of the present invention to provide, and further to provide a transparent liquid cleaning composition.

The present invention has the following configuration.
(1) A liquid cleaning composition containing N-acylglutamic acid salt, an amine oxide-based amphoteric surfactant, and water, and thickened by a step of adding an acidic substance to lower the pH.
(2) An acidic substance is added to a composition containing N-acylglutamate, an amine oxide-based amphoteric surfactant, and water to lower the pH to 5 to 6.7, and the viscosity of the composition at 25 ° C. By performing a thickening step of increasing the viscosity by 10 to 5000 times, the viscosity in a B-type viscometer (rotor: No. 2 to 4, 12 rpm or 30 rpm, 30 seconds, 25 ° C.) was increased to 100 to 50,000 mPa · s. The liquid cleaning composition according to (1).
(3) The liquid cleaning composition according to (1) or (2), wherein the amine oxide-based amphoteric surfactant is lauric acid amide propyl dimethylamine oxide and / or lauryl dimethyl amine oxide.
(4) The acyl group of N-acylglutamate is a fatty acid acyl group, a cocoyl group, a palm oil fatty acid acyl group, a lauroyl group, a palmitoyl group, a stearoyl group and a myristoyl group of a mixed fat of palm oil, palm oil and sunflower oil. The liquid cleaning composition according to any one of (1) to (3), which is one or more selected from oleyl groups.
(5) The liquid cleaning composition according to any one of (1) to (4), wherein the N-acylglutamate contains 14% by mass or more of N-palmitoyl glutamate and N-stearoyl glutamate in total.
(6) The method according to any one of (1) to (5), wherein the N-acylglutamic acid salt and the amine oxide amphoteric surfactant are contained in the liquid cleaning composition at a mass ratio of 2: 8 to 6: 4. Composition for liquid cleaning.
(7) The acyl group of N-acylglutamate is the acyl group of the fatty acid of the mixed fat of palm oil, palm oil and sunflower oil, and the amine oxide-based amphoteric surfactant is amidopropyldimethylamine laurate oxide (1). ) Or (2).
(8) The acyl group of N-acylglutamate is the acyl group of the fatty acid of the mixed oil of palm oil, palm oil and sunflower oil, and the amine oxide-based amphoteric surfactant is amidopropyldimethylamine laurate, which is a liquid. The liquid cleaning composition according to (7), which is contained in the cleaning composition at a mass ratio of 2: 8 to 6: 4 and thickened by a step of adding an acidic substance to lower the pH to 5 to 6.15. thing.
(9) The acyl group of N-acylglutamate is a lauroyl group and / or a cocoyl group, and the amine oxide-based amphoteric surfactant is amidopropyldimethylamine laurate, and the mass ratio is 2 in the liquid cleaning composition. The liquid cleaning composition according to (1) or (2), which is contained in a ratio of 8 to 6: 4 and thickened by a step of adding an acidic substance to lower the pH to 5.4 to 6.15.
(10) The acyl group of N-acylglutamate is the acyl group of the fatty acid of the mixed oil of palm oil, palm oil and sunflower oil, and the amine oxide-based amphoteric surfactant is lauramine oxide, which is a composition for liquid cleaning. The liquid washing according to (1) or (2), which is contained in a mass ratio of 4: 6 to 6: 4 and thickened by a step of adding an acidic substance to lower the pH to 5.85 to 6.7. Composition for.
(11) The liquid cleaning according to any one of (1) to (10), wherein the acidic substance is one or more selected from hydrochloric acid, sulfuric acid, nitric acid, phosphoric acid, lactic acid, succinic acid, citric acid, and acylaspartate. Composition.
(12) The liquid cleaning composition according to any one of (1) to (11), which is transparent.
(13) The liquid cleaning composition according to any one of (1) to (12), wherein the N-acylglutamate and the amine oxide amphoteric surfactant have a string-like micelle structure.
(14) An acidic substance was added to a composition containing N-acylglutamate, an amine oxide-based amphoteric surfactant, and water to lower the pH to 5 to 6.7, and the viscosity of the composition at 25 ° C. By performing a thickening step of increasing the viscosity by 10 to 5000 times, the viscosity in a B-type viscometer (rotor: No. 2 to 4, 12 rpm or 30 rpm, 30 seconds, 25 ° C.) was increased to 100 to 50,000 mPa · s. The method for producing a liquid cleaning composition according to (1) or (2).

By adopting the structure of the present specification, it is possible to prepare a liquid cleaning composition in which a cleaning solution having an initial value of less than 10 mPa · s and showing no viscosity is thickened 10 to 5000 times. By adopting the configuration of the present invention, it is possible to provide a liquid cleansing composition for washing skin, scalp and hair, which foams faster and has excellent foam quality. The liquid cleaning composition of the present invention has a viscosity suitable for use. By adopting the configuration of the present invention, it is possible to thicken the viscosity to a high viscosity of 100 to 50,000 mPa · s without adding a thickener, so that it can be quickly dispersed in water and quickly foamed at the time of use. Further, the liquid cleaning composition of the present invention can be made transparent. Also, there is no null after rinsing.

It is an image which observed the relationship between the pH and transparency of the aqueous solution of N-acylglutamate. It is a graph which measured the dynamic viscoelasticity of Test Example 1 and confirmed the behavior peculiar to the string-shaped micelle.

The present invention relates to a liquid cleaning composition containing N-acylglutamate, an amine oxide-based amphoteric surfactant, and water, which comprises a step of lowering the pH and thickening by lowering the pH. It is an invention.
The N-acylglutamate used in the present invention may be produced by the method described in Japanese Patent No. 4257442 or Japanese Patent No. 4770286 and used, or is commercially available as an anionic surfactant for cosmetics. You may use the thing. For example, those sold by Ajinomoto Healthy Supply Co., Ltd. under the trade name of "Amisoft" and those sold by Asahi Kasei Finechem Co., Ltd. under the trade name of "Amino Surfact" may be used. As the N-acylglutamate used in the present invention, those having cocoyl, palm fatty acid, palm fatty acid / palm fatty acid / sunflower fatty acid mixture, stearoyl, lauroyl, palmitoyl, oleyl, and myristoylation groups introduced as acyl groups can be used. One or more of these compounds and compositions containing the compounds can be appropriately selected and used.
In the present invention, in consideration of usability, it is particularly preferable to introduce coconut fatty acid / palm fatty acid / sunflower fatty acid as an acyl group, or to contain N-palmitoyl glutamic acid salt and N-stearoyl glutamic acid salt in a total amount of 14% by mass or more. ..
In the liquid cleaning composition of the present invention, N-acylglutamic acid salt is blended in an amount of 1 to 15% by mass, preferably 1 to 10% by mass.

The N-acylglutamate used in the present invention can be produced by the method described in Japanese Patent No. 4257442 or Japanese Patent No. 4770286. For example, it can be produced by condensing fatty acid halide and glutamic acid in the presence of an alkali, and adding an organic acid or an inorganic acid to the obtained reaction solution to precipitate N-long-chain acylglutamic acid. The obtained N-long-chain acylglutamic acid can be reacted with a basic substance under alkaline conditions to form a salt. The obtained reaction solution containing N-long-chain acylglutamic acid and / or a salt thereof in a high concentration is spray-dried and then made into powders or granules that are easy to handle by a fluid granulation method. For example, the production of N-acylglutamate using the above-mentioned coconut fatty acid / palm fatty acid / sunflower fatty acid can be produced by the reaction of the mixed fatty acid chloride with glutamic acid to obtain a powder.
As the type of salt of N-acylglutamate, an alkali metal salt such as sodium and potassium, an alkaline earth metal salt, an alkanolamine salt such as triethanolamine, and a basic amino acid salt such as lysine and arginine are used. be able to. Alkali metal salts are preferable, and sodium salts and potassium salts are particularly preferable, in consideration of foam quality and skin safety when used as a liquid cleaning agent.

As the amine oxide-based amphoteric surfactant used in the present invention, commercially available amphoteric surfactants for cosmetics can be used. For example, the display name is lauramidopropylamine oxide (compound name: lauric acid amidepropyldimethylamine oxide: trade name: "softazoline LAO-C" manufactured by Kawaken Fine Chemicals Co., Ltd.), and the display name is myristamidepropylamine oxide (compound name: myristin). Acid amide propyl dimethylamine oxide), a mixture of lauramide propylamine oxide and myristamide propylamine oxide (trade name: "AMMONYX LMDO" manufactured by Stepan), display name cocamidopropylamine oxide (compound name: coconut oil fatty acid amide propyldimethyl) Amine oxide: Trade name: "AMMONYX CDO SPECIAL" manufactured by Stepan) Display name Lauramine oxide (Compound name: Lauryldimethylamine oxide: Trade name: "Wandamine OX-300" manufactured by Shin Nihon Rika Co., Ltd.) can be mentioned. Of these, lauramidopropylamine oxide and lauramine oxide are particularly preferable.
The blending amount of the amine oxide-based amphoteric surfactant used in the present invention is 1 to 20% by mass, more preferably 3 to 15% by mass, and more preferably 3 to 12% by mass per the liquid cleaning composition of the present invention. Is preferable.

In the liquid cleaning composition of the present invention, the blending ratio of N-acylglutamate, which is a cleaning component, and an amine oxide amphoteric surfactant is 2: 8 to 6: 4 in terms of the mass ratio of the blended amount in the composition. It is preferable to do so. When an acidic substance is added to the composition having this blending ratio to lower the pH, the composition is transparently and uniformly dissolved and thickened. The thickened liquid cleaning composition is easy to take out from the container, and when it is whipped by picking it up, it can be whipped quickly and the feeling of use is good.

In order to obtain a preferable viscosity of the liquid cleaning composition of the present invention without adding a thickener, it is necessary to appropriately adjust the pH of the composition. That is, the step of adding an acidic substance to the composition obtained by mixing N-acylglutamate and an amine oxide amphoteric surfactant to lower the pH is always performed. N-acylglutamate causes a decrease in the viscosity of the composition when the pH is adjusted improperly, causing precipitation and a decrease in transparency. However, the composition of the present invention makes the composition transparent and viscous. Is obtained. In the present invention, when the blending ratio of N-acylglutamate and amine oxide amphoteric surfactant is 2: 8 to 6: 4 by mass ratio, a step of lowering the pH is taken to adjust the pH of the composition to 5 to 6. It is essential to keep it in 7.
Therefore, in the production of the composition of the present invention, all the ingredients are mixed and the final pH is lowered to be within pH 5 to 6.7 by adding an acidic substance. At this time, it is permissible to add a base to make fine adjustments. In order to lower the pH, a general acidic substance usually used in cosmetics may be used, and the same thickening effect can be obtained if the aqueous solution can be adjusted to a desired pH regardless of which substance is used. Be done. Examples of acidic substances include inorganic acids such as hydrochloric acid, sulfuric acid, nitrate and phosphoric acid, and organic acids such as citric acid, succinic acid and lactic acid. Further, as an acidic substance, an acidic amino acid-based surfactant other than acylglutamic acid such as acylaspartate may be used.
When the liquid composition of the present invention is used as a cosmetic, it is preferable to use citric acid as an acidic substance, and when 0.5 to 2% by mass of citric acid is added, the pH becomes 5 to 6.7 and the composition thickens. .. Sodium hydroxide and potassium hydroxide may be used for fine adjustment. When the pH of the composition containing N-acylglutamate and an amine oxide amphoteric surfactant can be lowered to be within pH 5 to 6.7, the liquid cleaning composition thickens. Then, there is no precipitation of N-acylglutamate or amine oxide amphoteric surfactant, and a highly transparent, weakly acidic composition is obtained. The viscosity of this liquid cleaning composition is 100 mPa · s or more, which is the minimum required viscosity for the liquid cleaning composition when measured with a B-type viscometer at room temperature, and 1000 to 40,000 mPa · s under the optimum conditions. It exhibits s, and further 50,000 mPa · s. It can also be filled in a tube container, in which case the viscosity is preferably 6000 mPa · s or more.

The mechanism of thickening of the present invention is that the surface tension of the amine oxide-based amphoteric surfactant solution increases in a pH-dependent manner, and N-acylglutamate is in the range of pH 5 to 6.7 through the step of lowering the pH. It is considered that the viscosity of the solution increases by forming a molecular aggregate such as a string-like micelle between the molecule and the amine oxide-based surfactant molecule. Further, it is considered that the solubility is improved by the interaction between the N-acylglutamate molecule and the amine oxide-based surfactant molecule, the precipitation of N-acylglutamate is suppressed, and the transparency is maintained. .. In order to form a molecular aggregate and thicken it, the sense of size (critical filling type or critical filling parameter) including the charged state of the hydrophilic part and the hydrophobic part of the surfactant molecule (N-acylglutamate) is "cut". It is known that it needs to be "head-conical"(references;"intermolecular force and surface force 2nd edition" by JN Israel Ativiri, published by Asakura Shoten), but it is actually cylindrical. It is hard to become a cone and has a conical shape. In this form, by blending amine oxide, the amine oxide molecule is incorporated between the N-acylglutamate molecules in the solution, and the critical filling parameter that combines the two types of molecules becomes a truncated cone shape. It is expected that string-like micelles will be formed as they approach.
String-shaped micelles have a polymer-like string-like structure when viewed macroscopically, unlike spherical micelles formed by general surfactants. Therefore, in water, they are entangled with each other and form a network structure, so that they exhibit a peculiar viscoelastic behavior having not only viscosity but also elasticity like rubber. The difference between string micelles and polymers is that in string micelles, multiple molecules associate to maintain a string structure, whereas in polymers, one molecule forms a single string, so the former is entangled. At the point of, the slip-through occurs, whereas the latter does not. Therefore, the composition of the present invention is different from the conventional polymer-blended cleaning agent in its viscoelastic behavior and usability. In the case of a cleaning agent with string-shaped micelles formed, the string-shaped micelle structure is destroyed when water is added and rubbed on the skin, so it is easier to blend with water and foam than a liquid cleaning agent thickened with polymer. It can be easily used.
The fact that the surfactant forms string-like micelles can be confirmed by transmission electron micrographs as disclosed in Japanese Patent No. 5296571, and can also be confirmed by measuring dynamic viscoelasticity. ..

The liquid composition of the present invention does not contain a so-called cream-like detergent that is thickened by precipitation of crystals. The appearance of the creamy detergent is opaque.

In the liquid cleaning composition of the present invention, an anionic surfactant, an amphoteric surfactant, as an optional component other than the N-acylglutamate and an amine oxide-based amphoteric surfactant, as long as the effect of the present invention is not adversely affected. A cationic surfactant and a nonionic surfactant can be appropriately blended.

The liquid cleaning composition of the present invention may contain polyhydric alcohols, sugars, sugar alcohols, preservatives, sequestrants, fragrances and the like. In addition, other medicinal ingredients and physiologically active ingredients can be contained. A thickener is basically unnecessary, but it is possible to add a small amount of a water-soluble polymer for the purpose of improving the feel. For example, a total amount of a cationic polymer such as [2-hydroxy-3- (trimethylammonio) propyl] dextran chloride, sodium hyaluronate, pullulan, etc. is 0.2% by mass or less, more preferably 0.15% by mass. If it is% or less, it may be blended.

Examples of polyhydric alcohols, sugars, and sugar alcohols to be added include glycerin, diglycerin, 1,3-butylene glycol, propylene glycol, dipropylene glycol, 1,2-pentanediol, glucose, sorbitol, mannose, mannitol, and galactose. Examples thereof include galactitol, maltose, martitol, trehalose, erythrose, erythritol, xylitol, xylitol, sucrose, lactose, lactitol, and difractose anhydrate.

Moreover, as a preservative, methylparaben, ethylparaben and the like can be mentioned.

Examples of the metal ion sequestering agent include edetates such as disodium ethylenediaminetetraacetate, edetic acid, and sodium edetate. As medicinal ingredients, vitamin Cs such as L-ascorbic acid, L-ascorbic acid phosphate ester, L-ascorbic acid monopalmitic acid ester, L-ascorbic acid dipalmitic acid ester, L-ascorbic acid-2-glucoside, etc. , Whitening agents such as glutathione and yukinoshita extract, skin activators such as royal jelly and beech tree extract, blood circulation promoters such as capsaicin, zingeron, cantalistinki, caffeine, tannic acid, γ-orizanol, glycyrrhizic acid derivatives, Examples thereof include anti-inflammatory agents such as azulene and lysoteam chloride.

The liquid cleaning composition of the present invention is used by taking a required amount in hand, adding water or hot water, and whipping. It is suitable for facial cleansers and body cleansers because it easily foams and does not get slimy. It can also be used for shampoo, whole body shampoo for pets, and the like.

The present invention will be further described below with reference to test examples.
First, a preliminary test was conducted to confirm the characteristics of the N-acylglutamate used in the present invention. A solubility confirmation test was performed as a preliminary test 1, and a usability confirmation was performed as a preliminary test 2.
<Preliminary test 1: Solubility confirmation test of N-acylglutamate>
The following tests 1 to 3 were performed to confirm the solubility of N-acylglutamate.
1. (Palm fatty acid / palm fatty acid / sunflower fatty acid) Solubility confirmation test of sodium glutamate Using sodium glutamate (palm fatty acid / palm fatty acid / sunflower fatty acid) as N-acylglutamate, prepare an aqueous solution with a concentration of 10% by mass. bottom. In the preparation, the aqueous solution was heated to about 50 ° C. to completely dissolve it. The pH of the aqueous solution was 5.85.
Take this aqueous solution in a glass bottle with a screw cap, adjust the pH to 4.2, 5.0 with a 10 mass% citric acid aqueous solution, and adjust the pH to 7.0, 8.0 with a 10 mass% potassium hydroxide aqueous solution. It was adjusted. Finally, water was added so that the total surfactant concentrations contained in each aqueous solution were equal (the final surfactant concentration was 8% by mass). After leaving this glass bottle at 25 ° C. overnight, the appearance was visually observed. The observation image is shown in FIG.
As shown in FIG. 1, the aqueous solution of N-acylglutamate exhibited a clear liquid (not thickened) at pH 8.0 when observed in appearance after storage at 25 ° C. overnight, but other pH. The pH is 4.2 (white turbid cream), pH 5.0 (precipitation), pH 5.85 (precipitation), pH 7.0 (precipitation), and all the samples cause white turbidity, separation or precipitation under weakly acidic conditions. , It was confirmed that a liquid cleaning agent could not be obtained.
The acyl group of monosodium glutamate (palm fatty acid / palm fatty acid / sunflower fatty acid) had the fatty acid composition shown in Table 1 below when analyzed.

2. Potassium cocoyl glutamate solubility confirmation test Using potassium cocoyl glutamate (“Amisoft CK-11 (F)”) as N-acylglutamate, an aqueous solution having a concentration of 10% by mass was prepared. The pH of the aqueous solution was 5.84. The pH was adjusted using a 10 mass% citric acid aqueous solution or a 10 mass% potassium hydroxide aqueous solution in the same manner as described above, and 13 aqueous solutions were prepared from pH 4.0 to pH 10.0 at 0.5 intervals. After allowing each aqueous solution to stand at 25 ° C. overnight, the appearance was visually observed.
The aqueous solution of potassium cocoyl glutamate produced a white solid at pH 4.0, pH 4.5, and pH 5.0, and was a transparent liquid (not thickened) at pH 5.5 to pH 10.0. It was confirmed that under acidic conditions, all the samples were cloudy, separated or precipitated, and no liquid cleaning agent could be obtained. It was confirmed that it was transparently dissolved in the weakly acidic region, but none was thickened.
The constituent fatty acids of potassium coconut glutamate showed the constituent ratio of coconut oil fatty acid, and when analyzed, lauric acid was 58%, myristic acid was 18%, palmitic acid was 9%, stearic acid was 4%, and others were 11%. .. The summary is shown in Table 2.

3. 3. Sodium lauroyl glutamate, sodium myristoyl glutamate, sodium stearoyl glutamate, solubility confirmation test for each N-acylglutamic acid sodium lauroyl glutamate (Amisoft LS-11), sodium myristoyl glutamate (Amisoft MS-11), sodium stearoyl glutamate (Amisoft) HS-11P) was used to prepare aqueous solutions having a concentration of 10% by mass, respectively. The pH of the aqueous solution was pH 5.81 for sodium lauroyl glutamate, pH 6.10 for sodium myristyl glutamate, and pH 6.79 for sodium stearoyl glutamate. The pH was adjusted using a 10 mass% citric acid aqueous solution or a 10 mass% potassium hydroxide aqueous solution in the same manner as described above, and seven aqueous solutions were prepared from pH 5.0 to pH 8.0 at 0.5 intervals.
After allowing each aqueous solution to stand at 25 ° C. overnight, the appearance was visually observed.
The aqueous solution of sodium lauroyl glutamate produces a white precipitate at pH 5.0, pH 5.5, pH 6.0, and pH 6.5, and pH 7.0 to pH 8.0 are all transparent liquids (not thickened). there were.
The aqueous solution of sodium myristyl glutamate causes white precipitation or white dispersion at pH 5.0, pH 5.5, pH 6.0, pH 6.5, and pH 7.0, and pH 7.5 and pH 8.0 are transparent liquids (thickening). I didn't do it).
The aqueous solution of sodium stearoyl glutamate produced a white precipitate or white dispersion at pH 5.0, pH 5.5, pH 6.0, pH 6.5, pH 7.0, pH 7.5, and pH 8.0.
It was confirmed that under weakly acidic conditions, all the samples were cloudy, separated or precipitated, and no liquid cleaning agent could be obtained. In particular, the longer the acyl group was, the more remarkable it was.
From the above results, it was confirmed that N-acylglutamate tends to cause cloudiness, separation or precipitation under weakly acidic conditions, and it is difficult to obtain a liquid cleaning agent.

<Preliminary test 2: Confirmation of usability of N-acylglutamate (sensory evaluation test)>
Confirmed usability of monosodium glutamate ("Amisoft CK-11 (F)") and sodium lauroyl glutamate ("Amisoft LS-11") having the compositions shown in Table 1. A sensory evaluation test was performed in order to do so.
0.5 g was taken out into the palm, water of about 10 times the weight of N-acylglutamic acid powder was added to whisk, and the face was washed by a usual face washing method, and the foaming, slippery feeling, and moist feeling were evaluated on a 5-point scale. The subjects were 10 specialized panelists. A standard product was set for the evaluation. As a standard product, sodium N-acylglutamic acid for bar soap (fatty acid composition: lauric acid 8%, myristic acid 5%, palmitic acid 25%, stearic acid 41%, oleic acid 13%, and others 8%) was used for this evaluation. Was 3 out of 5 grades.
The test product was evaluated according to the following evaluation criteria.
(1) Foaming: Evaluated by the amount of foamed foam (more 5 → less 1), and the standard product is slightly inferior to foaming. Provided.
4.5 points or more and 5 points or less ◎: Very excellent in foaming.
3.5 points or more and less than 4.5 points ◯: Excellent foaming.
2.5 points or more and less than 3.5 points Δ: Poor foaming.
Less than 2.5 points ×: Very poor in foaming.
(2) Smooth feeling: Evaluated by the slippery feeling between the skin and fingers after rinsing (smooth 5 → non-smooth 1), and the standard product has excellent smooth feeling, so the standard "3 points" is ○: smooth feeling The following criteria were set as "excellent".
3.5 points or more and less than 5 points ◎: Very excellent in smoothness.
2.5 points or more and less than 3.5 points ◯: Excellent smoothness.
1.5 points or more and less than 2.5 points Δ: Inferior in smoothness.
Less than 1.5 points ×: Very inferior in smoothness.
(3) Moist feeling: Evaluated by the feeling of close contact between the skin and the palm after wiping off the moisture (moist 5 → refreshing 1), and the standard product has an excellent moist feeling, so the standard "3 points" is changed to "○: moist". The following criteria have been set as "excellent in feeling".
3.5 points or more and less than 5 points ◎: Very good moist feeling.
2.5 points or more and less than 3.5 points ○: Excellent moist feeling.
1.5 points or more and less than 2.5 points Δ: Poor moist feeling.
Less than 1.5 points ×: Very inferior in moist feeling.

(result)
When the evaluation of the standard product is "foaming △ evaluation, slippery feeling ○ evaluation, moist feeling ○ evaluation", the sodium glutamate (palm fatty acid / palm fatty acid / sunflower fatty acid) having the composition shown in Table 1 is "foaming ◎ evaluation, smooth feeling". Feeling ○ Evaluation, Moist feeling ○ Evaluation ”, Potassium cocoyl glutamate is“ Foaming ◎ Evaluation, Smooth feeling × Evaluation, Moist feeling × Evaluation ”, Sodium lauroyl glutamate is“ Foaming ◎ Evaluation, Smooth feeling × Evaluation, Moist feeling × Evaluation ”.

<Summary and consideration of preliminary tests 1 and 2>
From Preliminary Test 1, it was confirmed that N-acylglutamate tends to cause cloudiness, separation or precipitation under weakly acidic conditions, and it is difficult to obtain a liquid cleaning agent. However, it was confirmed that only cocoyl glutamate was partially dissolved in the weakly acidic region, and it was found that it was relatively more soluble in water than the other acylglutamic acid-based surfactants used in this test.
N-acylglutamic acid, which received high evaluations in all three items in the sensory evaluation test of the feeling of use (foaming, slippery feeling, moist feeling) from the preliminary test 2, has the composition shown in Table 1 (palm fatty acid / palm fatty acid / sunflower). Fatty acid) It was monosodium glutamate. Sodium lauroyl glutamate and potassium cocoyl glutamate were evaluated as components that had good foaming but lacked smoothness and moistness. This is because sodium lauroyl glutamate and potassium cocoyl glutamate are low in N-acylglutamate having a long-chain acyl group, that is, palmitoyl group and stearoyl group, and sodium lauroyl glutamate is 0% by mass and potassium cocoyl glutamate is 13% by mass in total. It was thought that it was due to the small amount. The results of this test were in agreement with the description in Japanese Patent No. 4257442. Based on these, in order to realize the best usability even when used as a liquid cleaning agent, 36 to 40% by mass of lauroyl glutamate is contained as N-acylglutamate, and palmitoyl glutamate and stearoyl glutamate are contained. 40 to 46% by mass is required as the total amount of. Considering that a good feeling of use is realized in the liquid cleaning composition of the present invention, the total amount of palmitoyl glutamate and stearoyl glutamate is required to be 14% by mass or more, more preferably 14 to 46% by mass, still more preferable. Is required in an amount of 36 to 46% by mass.

<Test Example 1: Appearance observation and viscosity change test of a liquid cleaning composition containing sodium glutamate and lauramidopropylamine oxide (palm fatty acid / palm fatty acid / sunflower fatty acid)>
Sodium glutamate (fatty acid composition in Table 1) as N-acylglutamate (palm fatty acid / palm fatty acid / sunflower fatty acid), lauramide propylamine oxide as amine oxide amphoteric surfactant (softazoline LAO-C manufactured by Kawaken Fine Chemicals Co., Ltd.) ) Was used to prepare a cleaning composition containing both components by a conventional method, and the appearance was observed and the change in fatty acid was tested.

1. 1. Test method First, (palm fatty acid / palm fatty acid / sunflower fatty acid) 10% aqueous solution of monosodium glutamate and 10% aqueous solution of lauramidopropylamine oxide are prepared. Next, using this, as shown in Table 3, (palm fatty acid / palm fatty acid / sunflower fatty acid) sodium glutamate: lauramidopropylamine oxide is 0:10, 2: 8, 4: 6, 5: 5, 6: An aqueous solution of a mixed surfactant having a concentration of 10% by mass having a blending ratio of 4, 8: 2, and 10: 0 was prepared. This aqueous solution was transparently dissolved and did not thicken when the compounding ratio was 0:10, 2: 8, 4: 6, 5: 5, and 6: 4, and precipitation occurred at 8: 2, 10: 0.
At this stage, none was visually judged to have viscosity, but as an initial value of viscosity, an attempt was made to measure the viscosity of these mixed solutions. B-type viscometer: Measurement was performed on a VISCO METER TV-25 (Toki Sangyo Co., Ltd.) with a No. 1 rotor, 60 rpm, 30 sec (measurement compatible range 10 to 90 mPa · s), which is a measurement condition for a low viscosity sample. Except for the compounding ratio of 10: 0, it was below the lower limit of the measurement suitability range. Although the value is outside the measurement applicable range, the viscosity measurement result is shown with <<>> in the upper part of Table 3 for reference (unit is mPa · s). Mixing ratio 0:10 is 3.5 mPa · s, 2: 8 is 4.3 mPa · s, 4: 6 is 4.5 mPa · s, 5: 5 is 4.0 mPa · s, 6: 4 is 4.0 mPa · s. s, 8: 2 was 3.9 mPa · s. At 10: 0, the solid precipitate was dispersed and exhibited a cream state (crystal precipitation). This composition having a blending ratio of 10: 0 was not in the category of the liquid composition of the present invention as described above, but was 1029 mPa · s as measured using the No. 2 rotor. For reference, the viscosity of pure water at 25 ° C. is 0.890 mPa · s (according to JIS Z 8803).
Regarding the pH, the pH of the composition obtained by simply mixing the two components was 6.31, 6.75, 6.72, 6.63, 6.5, 6.21 and 5.85.
Next, this solution was prepared to have the pH shown in Table 2 while adding 10% by mass potassium hydroxide aqueous solution or 10% by mass hydrochloric acid, and pH 5, pH 5.4, pH 5.6, pH 5.7, pH 5. An aqueous mixed surfactant solution adjusted to 85, pH6, pH6.15, pH6.3, and pH8 was obtained. Here, water was finally added so that the total concentration of the surfactant contained in each aqueous solution was equal (the total concentration of the final surfactant was 8% by mass).
After allowing this to stand at 25 ° C. for 24 hours, the appearance of the solution was visually observed. The appearance was evaluated according to the following criteria.
◎: Transparent uniform ○: Almost transparent uniform Δ: Semi-transparent uniform ×: White turbidity uniform × ×: Separation (including crystal precipitation)
In addition, the viscosity of the solution in which an increase in viscosity was visually observed was measured. The viscosity was measured using a B-type viscometer: VISCO METER TV-25 (Toki Sangyo Co., Ltd.) (measurement conditions: rotors 2 to 4, 12 rpm or 30 rpm, 30 sec). When the viscosity is not shown (it is shapashapa like water) or the viscosity is less than 100 mPa · s (10 to 99 mPa · s), it is indicated by "-" in the table.

2. Results Table 3 shows the results of appearance observation and viscosity measurement.

(Palm fatty acid / palm fatty acid / sunflower fatty acid) None of the aqueous solutions containing monosodium glutamate and lauramidopropylamine oxide alone thickened even after the step of lowering the pH. In addition, no aqueous solution containing a combination of sodium glutamate and lauramidopropylamine oxide (palm fatty acid / palm fatty acid / sunflower fatty acid) was thickened by the aqueous solution before the step of lowering the pH at any ratio. .. Here, it is stated that there is no thickened material from the result that the viscosity is not shown even when measured (it was shapashapa like water).
On the other hand, when an acidic substance is added to an aqueous solution containing a combination of sodium glutamate and lauramidopropylamine oxide (palm fatty acid / palm fatty acid / sunflower fatty acid) to lower the pH, the composition thickens and the composition becomes 146 to 13510 mPa · s. A viscous liquid cleaning composition was obtained. As for the degree of thickening, the viscosity of the composition before adding the acidic substance was shapashapa like water, so if the viscosity is 10 mPa · s, it means that the viscosity is increased 14 to 1351 times.
(Palm fatty acid / palm fatty acid / sunflower fatty acid) When the mixing ratio of monosodium glutamate and lauramidopropylamine oxide was 2: 8 to 6: 4, the pH-lowered substance thickened. Specifically, the mixing ratio of sodium glutamate and lauramidopropylamine oxide (palm fatty acid / palm fatty acid / sunflower fatty acid) is set to 2: 8 to 6: 4, and a step of adding an acidic substance to lower the pH is taken to raise the pH to 5 to 5. When adjusted to 6.15, a transparent and viscous liquid cleaning composition was obtained. More specifically, the mixing ratio of sodium glutamate and lauramidopropylamine oxide (palm fatty acid / palm fatty acid / sunflower fatty acid) is set to 2: 8, and an acidic substance is added to adjust the pH to 5 to 5.85 (palm fatty acid). / Palm fatty acid / Sunflower fatty acid) The mixing ratio of sodium glutamate and lauramidopropylamine oxide is 4: 6, and an acidic substance is added to adjust the pH to 5.6 to 6.15. (Palm fatty acid / Palm fatty acid / Sunflower fatty acid) ) The mixing ratio of sodium glutamate and lauramidopropylamine oxide is 5: 5, and an acidic substance is added to adjust the pH to 5.6 to 6.15. (Palm fatty acid / palm fatty acid / sunflower fatty acid) Sodium glutamate and lauramide It was found that a transparent and viscous liquid cleaning composition was obtained by adjusting the mixing ratio of propylamine oxide to 6: 4 and adding an acidic substance to adjust the pH to 5.6 to 5.85. As shown in Table 3, "pH, compounding ratio of (palm fatty acid / palm fatty acid / sunflower fatty acid) sodium glutamate and lauramidopropylamine oxide" was (pH 5 to 5.85, compounding ratio 2: 8), (pH 5. Add acid to 6 to 6.15, blending ratio 4: 6), (pH 5.6 to 6.15, blending ratio 5: 5), (pH 5.6 to 5.85, blending ratio 6: 4). It was confirmed that a transparent and viscous liquid cleaning composition could be obtained by lowering the pH using the drug.
Since it was difficult to specify the structural change of the composition obtained by the step of lowering the pH by general physicochemical measurement, in the present invention, the composition is specified by specifying the manufacturing process. Was decided to be specified.

<Test Example 2: Transparency and viscosity change test of a liquid cleaning composition containing sodium lauroyl glutamate and lauramidopropylamine oxide>
"Sodium lauroyl glutamate (Ajinomoto Healthy Supply Co., Ltd. Amisoft LS-11)" as N-acylglutamate, "Lauramide propylamine oxide (Softazoline LAO-C, manufactured by Kawaken Fine Chemicals Co., Ltd.)" as an amine oxide amphoteric surfactant The transparency and viscosity change of the liquid composition containing both components were tested using Amisoft LS-11. The constituent fatty acid of Amisoft LS-11 is lauric acid.

1. 1. Test Method An aqueous solution having a concentration of 10% by mass containing sodium lauroyl glutamate or lauramidopropylamine oxide was prepared, and these were mixed at a ratio of 0:10 to 10: 0 as shown in Table 4. This solution was transparent except at a ratio of 10: 0, but was not thickened.
And when the mixing ratio of sodium lauroyl glutamate: lauramidopropylamine oxide is 0:10, 2: 8, 4: 6, 5: 5, 6: 4, 8: 2, 10: 0, the pH of the composition is , 6.31, 6.81, 6.71, 6.59, 6.44, 6.10, 5.76.
This solution was then added with 10% by weight potassium hydroxide aqueous solution or 10% by weight hydrochloric acid to obtain a solution having the pH shown in Table 4. Finally, water was added so that the total concentration of surfactant contained in each solution was equal (the total concentration of final surfactant was 8% by mass).
After allowing this to stand at 25 ° C. for 24 hours, the appearance of the solution was visually observed. The appearance was evaluated and the viscosity was measured in the same manner as in Test Example 1.

2. Results Table 4 shows the results of appearance observation and viscosity measurement.

None of the aqueous solutions containing sodium lauroyl glutamate and lauramidopropylamine oxide alone thickened even after the step of lowering the pH. In addition, the aqueous solution containing a combination of sodium lauroyl glutamate and lauramidopropylamine oxide was not thickened by the aqueous solution before the step of lowering the pH at any ratio. Here, it is stated that there is no thickened material from the result that the viscosity is not shown even when measured (it was shapashapa like water).
On the other hand, when an acidic substance is added to an aqueous solution containing a combination of sodium lauroyl glutamate and lauramidopropylamine oxide to lower the pH, the composition becomes thicker, and a liquid cleaning composition having a viscosity of 343 to 9140 mPa · s becomes available. Obtained. As for the degree of thickening, the viscosity of the composition before adding the acid was shapashapa like water, so if the viscosity is 10 mPa · s, it means that the viscosity is increased 34 to 914 times.
When the mixing ratio of sodium lauroyl glutamate and lauramidopropylamine oxide was 2: 8 to 6: 4, a thickening cleaning composition was obtained by lowering the pH. Specifically, a cleaning composition thickened when an acidic substance was added to adjust the pH to 5.4 to 6 was obtained. More specifically, the mixing ratio of sodium lauroyl glutamate and lauramidopropylamine oxide is set to 2: 8, and the pH is adjusted to 5.4 to 5.9. The mixing ratio of sodium lauroyl glutamate and lauramidopropylamine oxide is set to 4: 6 and adjust the pH to 5.81 to 6, adjust the mixing ratio of sodium lauroyl glutamate and lauramidopropylamine oxide to 5: 5 and adjust the pH to 5.6 to 5.9, adjust the pH to 5.6 to 5.9, sodium lauroyl glutamate and lauramidopropyl. It was found that a clear and viscous liquid cleaning composition was obtained by adjusting the mixing ratio of amine oxides to 6: 4 and adjusting the pH to 5.6. As shown in Table 4, the "pH, compounding ratio of sodium lauroyl glutamate and lauramide propylamine oxide" was (pH 5.4 to 5.9, compounding ratio 2: 8), (pH 5.81 to 6, compounding ratio 4). Transparency and viscosity by adding an acidic substance to lower the pH so as to have: 6), (pH 5.6 to 5.9, compounding ratio 5: 5), (pH 5.6, compounding ratio 6: 4). It was confirmed that a liquid cleaning composition having the above was obtained.

<Test Example 3: Transparency and viscosity change test of a liquid cleaning composition containing potassium cocoyl glutamate and lauramidopropylamine oxide>
"Potassium cocoyl glutamate (Ajinomoto Healthy Supply Co., Ltd. Amisoft CK-11 (F))" as N-acylglutamate, and "Lauramide propylamine oxide (Sofazoline LAO manufactured by Kawaken Fine Chemicals Co., Ltd.) as an amine oxide amphoteric surfactant Using -C), tests were conducted on the transparency and viscosity change of the liquid composition containing both components.

1. 1. Test Method A 10% by mass aqueous solution containing potassium cocoyl glutamate and lauramidopropylamine oxide was prepared and mixed at a ratio of 0:10 to 10: 0 as shown in Table 5. This solution was clear. At this time, the viscosity was not increased. And when potassium cocoyl glutamate: lauramidopropylamine oxide has a blending ratio of 0:10, 2: 8, 4: 6, 5: 5, 6: 4, 8: 2, 10: 0, the pH of the composition is , 6.31, 6.82, 6.74, 6.64, 6.49, 6.15, 5.84.
This solution was then added with 10% by weight potassium hydroxide aqueous solution or 10% by weight hydrochloric acid to obtain a solution having the pH shown in Table 5. Finally, water was added so that the total concentration of surfactant contained in each solution was equal (the total concentration of final surfactant was 8% by mass).
After allowing this to stand at 25 ° C. for 24 hours, the appearance of the solution was visually observed. The appearance was evaluated and the viscosity was measured in the same manner as in Test Example 1.

2. Results Table 5 shows the results of transparency observation and viscosity measurement.

None of the aqueous solutions containing potassium cocoyl glutamate and lauramidopropylamine oxide alone thickened even after the step of lowering the pH. In addition, the aqueous solution containing a combination of potassium cocoyl glutamate and lauramidopropylamine oxide was not thickened by the aqueous solution before the step of lowering the pH at any ratio. Here, it is stated that there is no thickened material from the result that the viscosity is not shown even when measured (it was shapashapa like water).
On the other hand, when an acidic substance is added to an aqueous solution containing a combination of potassium cocoyl glutamate and lauramidopropylamine oxide to lower the pH, the composition becomes thicker, and a liquid cleaning composition having a viscosity of 171 to 9350 mPa · s is obtained. Obtained. As for the degree of thickening, the viscosity of the composition before adding the acid was shapashapa like water, so if the viscosity is 10 mPa · s, it means that the viscosity is increased 17 to 935 times.
When the mixing ratio of potassium cocoyl glutamate and lauramidopropylamine oxide was 2: 8 to 6: 4, the pH was lowered to obtain a thickened cleaning composition. Specifically, when an acidic substance was added to adjust the pH to 5.4 to 6.15, a thickened cleaning composition was obtained. In other words, if the mixing ratio of potassium cocoyl glutamate and lauramidopropylamine oxide is set to 2: 8 to 6: 4, and the pH is lowered by adding an acidic substance, the pH is adjusted to 5.4 to 6.15 to achieve transparency and viscosity. A liquid cleaning composition having the above was obtained. More specifically, the mixing ratio of potassium cocoyl glutamate and lauramide propylamine oxide is set to 2: 8 and the pH is adjusted to 5.4 to 6, and the mixing ratio of potassium cocoyl glutamate and lauramide propylamine oxide is set to 4: 6. Adjust the pH to 5.85 to 6.15, adjust the mixing ratio of potassium cocoyl glutamate and lauramide propylamine oxide to 5: 5, and adjust the pH to 5.85 to 6, potassium cocoyl glutamate and lauramide propylamine oxide. It was found that a liquid cleaning composition having transparency and viscosity can be obtained by adjusting the mixing ratio of 6: 4 and adjusting the pH to 5.6 to 5.85. As shown in Table 6, "pH, mixing ratio of potassium cocoyl glutamate and lauramide propylamine oxide" is (pH 5.4 to 6, mixing ratio 2: 8), (pH 5.8 to 6.15, mixing ratio 4). : 6), (pH 5.85-6, compounding ratio 5: 5), (pH 5.6 to 5.85, compounding ratio 6: 4), a transparent and viscous liquid cleaning composition can be obtained. It was confirmed that it could be obtained.

<Test Example 4: Transparency and viscosity change test of liquid cleaning composition containing N-acylglutamic acid and lauramine oxide>
As N-acylglutamate, sodium glutamate (palm fatty acid / palm fatty acid / sunflower fatty acid) having the composition shown in Table 1 and "lauramine oxide (Wandamine OX-300) manufactured by Shin Nihon Rika Co., Ltd.) as an amine oxide amphoteric surfactant. Using, tests were conducted on the transparency and change in viscosity of the liquid composition containing both components.
1. 1. Test Method Similar to Test Example 1, an aqueous solution having a concentration of 10% by mass containing monosodium glutamate and lauramine oxide (palm fatty acid / palm fatty acid / sunflower fatty acid) was prepared, and this was shown in Table 6 at 0:10 to 10 :. It was mixed at a ratio of 0. Nothing was thickened at this stage. And (palm fatty acid / palm fatty acid / sunflower fatty acid) monosodium glutamate: lauramine oxide has a blending ratio of 0:10, 2: 8, 4: 6, 5: 5, 6: 4, 8: 2, 10: 0. At that time, the pH of the composition was 7.85, 7.44, 7.28, 7.12, 6.89, 6.26, 5.85. This solution precipitated except at a ratio of 0:10 and 2: 8.
This solution was then added with 10% by weight potassium hydroxide aqueous solution or 10% by weight hydrochloric acid to obtain a solution having the pH shown in Table 7. Finally, water was added so that the total concentration of surfactant contained in each solution was equal (the total concentration of final surfactant was 8% by mass).
After allowing this to stand at 25 ° C. for 24 hours, the appearance of the solution was visually observed. The appearance was evaluated and the viscosity was measured in the same manner as in Test Example 1.

2. Results Table 6 shows the results of transparency observation and viscosity measurement.

(Palm fatty acid / palm fatty acid / sunflower fatty acid) None of the aqueous solutions containing monosodium glutamate and lauramine oxide alone thickened even after the step of lowering the pH. In addition, no aqueous solution containing a combination of monosodium glutamate and lauramine oxide (palm fatty acid / palm fatty acid / sunflower fatty acid) was thickened by the aqueous solution before the step of lowering the pH at any ratio. Here, it is stated that there is no thickened material from the result that the viscosity is not shown even when measured (it was shapashapa like water).
On the other hand, when an acidic substance is added to an aqueous solution containing a combination of sodium glutamate (palm fatty acid / palm fatty acid / sunflower fatty acid) and lauramine oxide to lower the pH, the composition becomes thicker and has a viscosity of 168 to 9900 mPa · s. A liquid cleaning composition having was obtained.
As for the degree of thickening, since the viscosity of the composition before adding the acid was shapashapa like water, if the viscosity is 10 mPa · s, it means that the viscosity is increased 16 to 990 times.
(Palm fatty acid / palm fatty acid / sunflower fatty acid) When the mixing ratio of monosodium glutamate and lauramine oxide was 4: 6 to 6: 4, the pH was lowered to obtain a thickened cleaning composition. Specifically, a thickening composition was obtained in the range of pH 5.85 to 6.7. (Palm fatty acid / palm fatty acid / sunflower fatty acid) When the mixing ratio of monosodium glutamate and lauramine oxide is set to 4: 6 to 6: 4 and the pH is adjusted to the range of 5.85 to 6.7, a clear and viscous solution is obtained. Obtained. More specifically, the mixing ratio of sodium glutamate and lauramine oxide (palm fatty acid / palm fatty acid / sunflower fatty acid) is set to 4: 6, and the pH is adjusted to the range of 6.0 to 6.7 (palm fatty acid / palm fatty acid). / Sunflower fatty acid) Adjust the mixing ratio of sodium glutamate and lauramine oxide to 5: 5 and adjust the pH to the range of 6.0 to 6.7. (Palm fatty acid / palm fatty acid / sunflower fatty acid) of sodium glutamate and lauramine oxide It was clarified that when the mixing ratio was 6: 4 and the pH was adjusted in the range of 5.85 to 6.3, a clear and viscous solution was obtained. As shown in Table 6, "pH, compounding ratio of (palm fatty acid / palm fatty acid / sunflower fatty acid) monosodium glutamate and lauramidopropylamine oxide" is (pH 6 to 6.7, compounding ratio 4: 6), (pH 6 to It was confirmed that a transparent and viscous liquid cleaning composition can be obtained by setting 6.7, blending ratio 5: 5) and (pH 5.85-6.3, blending ratio 6: 4). ..

Similar to the above test, for sodium myristyl glutamate and sodium stearoyl glutamate, an aqueous solution was prepared in combination with lauramidopropylamine oxide, and an acidic substance was added to lower the pH to obtain a thickened liquid cleaning composition. Was done. As a concrete confirmation, a transparent substance having a viscosity of 912 mPa · s when a combination of sodium myristyl glutamate and lauramidopropylamine oxide was combined to make a blending ratio of 2: 8 and an acidic substance was added to lower the pH to pH 5.85. A liquid cleaning composition was obtained. The degree of thickening is 91 times higher if the viscosity is 10 mPa · s because the appearance of the composition before adding the acid was shapashapa like water. As for sodium stearoyl glutamate, a transparent liquid cleaning composition having a viscosity of 5730 mPa · s when the compounding ratio is 4: 6 in combination with lauramidopropylamine oxide and the pH is lowered to 5.85 by adding an acidic substance. was gotten. As for the degree of thickening, since the appearance of the viscosity of the composition before adding the acid was shapashapa like water, if the viscosity is 10 mPa · s, it is increased 573 times.

<Reference Test Example 1: Combination test of amphoteric surfactants other than N-acylglutamate and amine oxide amphoteric surfactants>
Using sodium glutamate (palm fatty acid / palm fatty acid / sunflower fatty acid) sodium glutamate having the composition shown in Table 1 as N-acylglutamate, and sodium cocoamphoacetate, sodium lauroamphoacetate, and lauramidopropyl betaine as other amphoteric surfactants, A similar test was conducted for the transparency and change in viscosity of the liquid composition.
1. 1. Test method (palm fatty acid / palm fatty acid / sunflower fatty acid) An aqueous solution having a concentration of 10% by mass containing sodium glutamate, sodium cocoamphoacetate, sodium lauroamphoacetate, and lauramidopropyl betaine was prepared. As shown in Table 8, sodium glutamate (palm fatty acid / palm fatty acid / sunflower fatty acid) and each amphoteric surfactant were mixed at a ratio of 0:10 to 10: 0. Precipitation occurred in this aqueous solution at 2: 8, 4: 6, 5: 5, 6: 4, 8: 2, 10: 0 other than 0:10. At this time, nothing was thickened. This solution was then added with 10% by weight potassium hydroxide aqueous solution or 10% by weight hydrochloric acid to obtain a solution having the pH shown in Table 7. Finally, water was added so that the total concentration of surfactant contained in each solution was equal (the total concentration of final surfactant was 8% by mass).
After allowing this to stand at 25 ° C. for 24 hours, the appearance of the solution was visually observed. The appearance was evaluated and the viscosity was measured in the same manner as in Test Example 1.

2. Results Table 7 shows the results of transparency observation and viscosity measurement.

Amphoteric surfactants sodium cocoamphoacetate, sodium lauroamphoacetate, and lauramidpropylbetaine are combined with N-acylglutamic acid: ((palm fatty acid / palm fatty acid / sunflower fatty acid) sodium glutamate) to lower the pH by adding an acidic substance. Even after taking the steps, the viscosity remained less than 10 mPa · s, and none showed an increase in viscosity.

From the results of Test Examples 1 to 3 and Reference Test Example 1 above, N-acylglutamate and an amine oxide amphoteric surfactant were used in combination, and an acidic substance was added to lower the pH, and the pH was adjusted to 5-6. It was found that when the pH was adjusted to the range of 7, the viscosity was increased, and a transparent and appropriate viscosity liquid cleaning composition was obtained. N-acylglutamate and amine oxide amphoteric surfactant are combined to make the compounding ratio 2: 8 to 6: 4, and an acidic substance is added to lower the pH, and the pH is in the range of 5 to 6.7. It was found that when adjusted, the viscosity was increased and a transparent liquid cleaning composition having a viscosity of 146 to 13510 mPa · s was obtained. As for the degree of thickening, since the viscosity of the composition before adding the acid was as shapashapa as water, if the viscosity is 10 mPa · s, it means that the viscosity is increased 14 to 1351 times. .. As described above, it is an unprecedented remarkable effect that the solution containing acylgutamate, which is difficult to thicken by the prior art, is thickened up to 1351 times by adopting the configuration of the present invention without adding a thickener. Is.
Further, from the result of Reference Test Example 1, (palm fatty acid / palm fatty acid / sunflower fatty acid) sodium glutamate) can be combined with sodium cocoamphoacetate, sodium lauroamphoacetate, and lauramidopropyl betaine, and an acidic substance is further added to the composition. It was found that even if the pH was lowered, the viscosity did not increase. That is, it was found that (palm fatty acid / palm fatty acid / sunflower fatty acid) sodium glutamate) is specifically thickened by lowering the pH by adding an acidic substance in combination with an amine oxide amphoteric surfactant.
As described above, in Test Examples 1 to 3, the present invention has been described by showing a test example in which the total amount of the surfactant is fixed at 8%.
Next, a test example in which the total amount of the surfactant is increased and a test example in which a polyhydric alcohol or the like is blended are shown. This is a confirmation test that the present invention holds at various surfactant concentrations and that the present invention can be applied as it is in the formulation design of cosmetics. The test products (cleaning compositions) of Test Examples 1 to 3 above may be used as a washing pigment or shampoo without adding anything as they are.

<Examination and evaluation of formulation examples of liquid cleaning compositions>
1. 1. Evaluation when the concentration of the surfactant is 16% by mass N-acylglutamate is 9.6% by mass, the amine oxide amphoteric tenside is 6.42% by mass, and the total concentration of the surfactant is the total amount. A formulation example set to about 16% by mass is shown in Table 8 below. Citric acid was used as the acid for lowering the pH. The evaluation of transparency and viscosity is the same as in Test Example 1. In addition, in the prescription example shown below, the prescription No. The number in is the number of the prescription example as it is.

As shown in Table 8, even when the total amount of the surfactant is 16% by mass by combining N-acylglutamate and amine oxide amphoteric surfactant, the step of adding an acidic substance to lower the pH is taken. A liquid cleaning composition having preferable viscosity and transparency was obtained. In this test, citric acid was used as an acidic substance, and citric acid was added in an amount of 1% by mass, 0.8% by mass, and 0.6% by mass to lower the pH of the composition. By this step, the pH of the composition is 5.58 (Prescription No. 1), 5.89 (Prescription No. 2), 5.88 (Prescription No. 2) from pH 6.38 (Prescription No. 4) before adding the acidic substance. It decreased to Formula No. 3), and the viscosity decreased from the state of Shapa Shapa (Prescription No. 4) like water before adding an acidic substance to 2335 mPa · s (Prescription No. 1) and 25850 mPa · s (Prescription No. 2). ), 4425 mPa · s (Formulation No. 3) to obtain a transparent liquid cleaning composition having a preferable viscosity. The liquid cleaning compositions of Formulation Examples 1 to 3 had quick foaming and were easy to foam. And there was no slimy feeling of use, and it was refreshing after washing.

2. Evaluation of Formulation Examples to Add Polyhydric Alcohol and Other Surfactants A composition containing glycerin and sorbitol, which are typical components of polyhydric alcohols that are often blended in skin cleansers, was formulated. Further, a composition containing cocoylglycine K and lauramidopropyl hydroxysultaine, which are general-purpose raw materials, as other optional components was formulated and evaluated. Table 9 shows an example of the formulation used in the test. The transparency and viscosity were evaluated in the same manner as in Test Example 1.

As shown in Table 9, even when polyhydric alcohol (glycerin and / or sorbitol) is added as an optional component and cocoylglycine K or lauramidopropyl hydroxysultaine is added as another surfactant, the composition is increased by lowering the pH. Sticky. That is, for liquid cleaning having preferable viscosity and transparency even if any component is blended by taking a step of combining N-acylglutamate and an amine oxide amphoteric surfactant and adding an acidic substance to lower the pH. It was confirmed that the composition was obtained.
Looking at the composition in Table 9 in detail, the total amount of the surfactant (N-acylglutamate and amine oxide amphoteric surfactant) used in the present invention is 16% by mass. Of these, Formulation Examples 10 and 11 contain about 4% by mass of the optional components cocoylglycine potassium and lauramidopropyl hydroxysultaine, so that the total amount of the surfactant is about 20% by mass (20.04 and 19. 91). In addition, 5% by mass of glycerin is blended in all compositions, and sorbitol is further blended in Formulation Example 9.
In this test, citric acid was used as the acid, and citric acid was 1% by mass (formulation No. 5), 0.95% by mass (formulation No. 6), 0.9% by mass (formulation No. 7), 0.8. Mass% (formulation No. 8), 0.8 mass% (formulation No. 9), 0.9 mass% (formulation No. 10), 0.8 mass% (formulation No. 11), 0.7 mass% (Formulation No. 12), 0.6% by mass (Formulation No. 13), and 0.5% by mass (Formulation No. 14) were added to lower the pH of each composition. By this step, the pH of the composition was changed from pH 6.4 (formulation No. 15) before the addition of the acidic substance to 5.58 (formulation No. 5), 5.59 (formulation No. 6), and 5.7 (formulation No. 6). Prescription No. 7), 5.82 (Prescription No. 8), 5.78 (Prescription No. 9), 5.87 (Prescription No. 10), 5.56 (Prescription No. 11), 5.86 ( It decreased to Formulation No. 12), 5.97 (Prescription No. 13), and 6 (Prescription No. 14), and the viscosity was 2360 mPa from the state of Shapa Shapa (Prescription No. 15) like water before adding acid. S (Prescription No. 5), 4507 mPa · s (Prescription No. 6), 12170 mPa · s (Prescription No. 7), 25380 mPa · s (Prescription No. 8), 24480 mPa · s (Prescription No. 9), 7810 mPa -S (Prescription No. 10), 39750 mPa · s (Prescription No. 11), 17500 mPa · s (Prescription No. 12), 3860 mPa · s (Prescription No. 13), 149 mPa · s (Prescription No. 14) Thus, a transparent liquid cleaning composition having a preferable viscosity was obtained.
As shown in Formulation Examples 5 to 14, in any of the compositions, the viscosity of the composition could be increased without adding a thickener by taking a step of adding an acidic substance to lower the pH. In the step of adding the acid, the step of adding citric acid in the range of 0.5 to 1% by mass was taken, and the pH of the composition was kept in the range of pH 5 to 6.7 obtained from the above test results. Then, a transparent liquid cleaning composition having a pH range of 5.56 to 6 and 149 to 39750 mPa · s was obtained. The liquid cleaning compositions of Formulation Examples 5 to 14 were all quick to foam and easy to use. And there was no feeling of use with a null. After washing, a moist feeling was obtained due to the effect of the polyhydric alcohol blended at the same time.

3. 3. Evaluation when the total concentration of the surfactant was 15% by mass N-acylglutamate was 3% by mass, the amine oxide amphoteric surfactant was 12% by mass, and the total concentration of the surfactant was 15% by mass. A prescription example is shown in Table 10. The evaluation of transparency and viscosity is the same as in Test Example 1.

As shown in Table 10, even when the total concentration of the surfactant is 15% by mass (3% by mass of N-acylglutamate and 12% by mass of the amine oxide amphoteric surfactant), an acidic substance is added to compose the composition. By taking the step of lowering the pH of the substance, a liquid cleaning composition having preferable viscosity and transparency was obtained.
Looking at the compositions in Table 10 in detail, as shown in Formulation Examples 16 to 20, in any of the compositions, by taking a step of adding an acidic substance to lower the pH, the composition without adding a thickener is taken. I was able to increase the viscosity of the object. In the step of adding the acid, the step of adding citric acid in the range of 0.5 to 1.5% by mass was taken, and the pH of the composition was kept in the range of pH 5 to 6.7 obtained from the above test results. In this example, a transparent liquid cleaning composition having a viscosity in the range of pH 5.12 to 5.89 and a viscosity of 1236 to 5700 mPa · s was obtained. The liquid cleaning compositions of Formulation Examples 16 to 20 were quick to foam and easy to use. And there was no feeling of use with a null.
Next, sodium hyaluronate (trade name: FCH-SU hyaluronate, manufactured by Kikkoman Biochemifa Co., Ltd.), dipotassium glycyrrhizinate, chloride [2-hydroxy-3- (2) Trimethylammonio) Propyl] Dextran (manufactured by Meito Sangyo Co., Ltd., trade name: CDC) is blended in the formulation No. Twenty-two liquid facial cleansers were prepared. The transparency and viscosity were evaluated in the same manner as in Test Example 1.

Prescription No. 22 (Liquid face wash) Mass%
1. 1. (Palm fatty acid / palm fatty acid / sunflower fatty acid) Sodium glutamate 9.6
2. Lauramide propylamine oxide (30% aqueous solution) 21.4
3. 3. Citric acid 0.9
4. Cocoyl glycine potassium (30% aqueous solution) 13.4
5. Sodium hyaluronate 0.01
6. Maltitol (75% aqueous solution) 1
7. Dipotassium glycyrrhizinate 0.1
8. (Chloride [2-hydroxy-3- (trimethylammonio) propyl] dextran)
0.1
9. Diglycerin 2
10. Residual of purified water

Composition A was prepared by mixing 1, 2, 4 to 10 components by a conventional method. Next, an aqueous citric acid solution in which 3 was added to a part of 10 was added to the composition A to thicken the composition A to obtain a liquid facial cleanser of Formulation Example 22. When the viscosity of the liquid facial cleanser of Formulation Example 22 was measured in the same manner as in Test Example 1, the pH was 5.82 and the viscosity was 6900 mPa · s. This viscosity was suitable for use as a liquid facial cleanser, which was easy to take out from the container to the palm of the hand. Also, the appearance was transparent and beautiful. This face wash was able to quickly disperse in water and foam quickly when used, and had a fine-textured foam quality. In addition, the foam was cut off well, there was no sliminess after rinsing, the feel after rinsing was excellent (there was a slippery feeling), and the moist feeling after towel drying was also good. There was no skin irritation.

<Prescription No. Another method of preparing 22 liquid facial cleansers>
The above-mentioned prescription No. In the composition of No. 22, a thickened liquid facial cleanser was obtained even when citric acid was added to the composition A as a grain.
In addition, a thickened liquid facial cleanser was also obtained when components 1, 2, 4 to 9 were added and mixed in a mixture of component 10: purified water and component 3: citric acid.

As mentioned above, Preliminary Tests 1 and 2, Test Examples 1 to 3, Prescription No. From the results of 1 to 22, the liquid cleaning composition having the constitution of the present invention contains N-acylglutamate, which has been difficult to dissolve and blend as a liquid preparation and thicken by the conventional technique. It was confirmed that the composition was a transparent liquid cleaning composition with a thickened thickness.
In a preliminary test, etc., as the fatty acid composition of the acylglutamic acid salt that gives a good feeling of use, an acylglutamic acid salt containing 14% by mass or more of palmitoyl glutamate and stearoyl glutamate in total was selected, and an amine oxide-based amphoteric acid salt was selected. By taking the process of lowering the pH by adding an acidic substance in combination with a surfactant, it is a safe, transparent, thickened liquid that has not only viscosity but also excellent usability (foaming, slippery feeling, moist feeling). It was confirmed that the composition was for cleaning.

<Confirmation that string-shaped micelles are formed (measurement of dynamic viscoelasticity)>
In order to confirm that the string-shaped micelles were formed, the dynamic viscoelasticity of the test product of Test Example 1 was measured. Specifically, the dynamic viscoelasticity of the sample prepared with a mixture ratio of sodium glutamate (palm fatty acid / palm fatty acid / sunflower fatty acid) and lauramidopropylamine oxide of 5: 5 and an acidic substance added to adjust the pH to 5.85. Measurements were made. The measuring device used was a stress-controlled rheometer AR-G2 (manufactured by TA Instruments), and a cone-and-plate system with a diameter of 4 cm (cone angle 1 °) was used. Frequency sweep measurement was performed in vibration measurement mode. The angular frequency was 0.01 to 100 rad / sec. The measurement temperature was 25 ° C.
A graph of the angular frequency dependence of the elastic modulus G'and the viscous modulus loss elastic modulus G'is shown in FIG. 2. The G'curve and the G'curve have intersections and are liquid-in the low frequency region. It was suggested that it behaves like (G'<G') and solid-like behavior (G'>G') in the high frequency region. This is a typical viscoelastic behavior found in string micelles.
The dotted line in the graph is the fitting curve to the Maxwell model.
The viscoelastic behavior of string micelles can be described by the Maxwell model, which has a single relaxation time for well-developed string micelles, depending on the degree of entanglement. This is shown in a model in which one spring showing Hooke's elastic component and one dashpot showing Newton's viscous component are connected in series.
τ _R is the relaxation time. ω _C is the frequency of the intersection of G'and G', and the value of the plateau region on the high frequency side of _{G 0.}

Equation 1

The measured values roughly matched the model calculated values, suggesting the formation of string-like micelles.

Claims (4)

N-acylglutamate, in which the acyl group of N-acylglutamate is the acyl group of the fatty acid of the mixed fat of palm oil, palm oil, and sunflower oil,
And lauramine oxide is an amine oxide-based amphoteric surface active agent,
Contains water,
A step of containing the N-acylglutamate and lauramine oxide in a liquid cleaning composition at a mass ratio of 4: 6 to 6: 4 and adding an acidic substance to lower the pH to 5.85 to 6.7. Liquid cleaning composition thickened by. N-acylglutamate containing 14% by mass or more of N-palmitoyl glutamate and N-stearoyl glutamate in total, and
Amine oxide-based amphoteric surfactant, amidopropyl laurate dimethylamine oxide,
Contains water,
The N-acylglutamate and amidopropyldimethylamine laurate oxide are contained in the liquid cleaning composition at a mass ratio of 2: 8 to 6: 4, and an acidic substance is added to adjust the pH to 5 to 6.15. Liquid cleaning composition thickened by the lowering step (excluding those containing 1.0 to 10% by mass of alkanolamide) . N-acylglutamate, in which the acyl group of N-acylglutamate is the acyl group of the fatty acid of the mixed oil of palm oil, palm oil, and sunflower oil,
Amine oxide-based amphoteric surfactant, amidopropyl laurate dimethylamine oxide,
Contains water,
The N-acylglutamate and amidopropyldimethylamine laurate oxide are contained in the liquid cleaning composition at a mass ratio of 2: 8 to 6: 4, and an acidic substance is added to adjust the pH to 5 to 6.15. Liquid cleaning composition thickened by the lowering step (excluding those containing 1.0 to 10% by mass of alkanolamide) . The liquid cleaning composition according to any one of claims 1 to 3, wherein the viscosity of a B-type viscometer (rotor: No. 2 to 4, 12 rpm or 30 rpm, 30 seconds, 25 ° C.) is increased to 100 to 50,000 mPa · s. ..

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