JPH0254400B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to liquid detergents containing water-soluble N-acyl neutral amino acid salts. In recent years, N-acyl neutral amino acid water-soluble salts have been increasingly used in shampoos and skin cleansers because they are hypoallergenic, foam well, and leave a pleasant feeling on the skin after use. Ta. However, an aqueous solution of N-acyl neutral amino acid water-soluble salt has a low viscosity, and when added to a liquid product, it tends to reduce the viscosity of the product, so it is difficult to thicken a liquid product containing this solution. It was hot. In the case of liquid products such as shampoos and skin cleansers, at least
A viscosity of about 50 cp is required, and although liquid detergents containing N-acyl neutral amino acid water-soluble salts are hypoallergenic and have excellent foaming properties, their commercial value is low. Conventionally, methods for thickening aqueous solutions of N-acyl neutral amino acid water-soluble salts include (1) blending water-soluble polymers such as methylcellulose, hydroxymethylcellulose, and polyacrylic acid, and (2) blending fatty acid alkanolamides. (3) Adding inorganic salts such as common salt or potassium chloride; (4) Adding fatty acid esters of higher alcohols and glycols. However, each of these methods has drawbacks, and none of them can be said to be a sufficient method. In other words, method (1) has the disadvantage that it feels slimy and stringy when used, and methods (2), (3), and (4) have poor cold resistance when blended to a suitable viscosity. Furthermore, method (4) has drawbacks such as poor foaming. The present inventors investigated a method for thickening an aqueous solution of a water-soluble N-acyl neutral amino acid salt without reducing cold resistance or foaming, and found that fatty acid diethanolamide and a specific water-soluble inorganic salt The inventors have discovered that the object can be achieved by using these in combination in a specific ratio, and have completed the present invention. That is, the present invention provides a N-acyl neutral amino acid water-soluble salt: 35-
80wt% b Fatty acid diethanolamide: 5-60wt% c Water-soluble inorganic salt: 5-60wt% as essential components (however, the total of a, b and c is
The present invention relates to a liquid detergent composition with improved thickening properties and cold resistance, characterized in that the composition has a concentration of 100 wt%). The acyl group of the N-acyl neutral amino acid water-soluble salt used in the composition of the present invention consists of a saturated or unsaturated fatty acid residue having 10 to 18 carbon atoms, such as coconut oil fatty acid, lauric acid, myristic acid, and oleic acid. Examples include residues of fatty acids such as acids. The neutral amino acid of the N-acyl neutral amino acid water-soluble salt is selected from sarcosine, N-methyl-β-alanine, and the cation forming the water-soluble salt is alkali metals such as sodium and potassium, monoethanolamine, diethanolamine, Alkanolamines such as triethanolamine, basic amino acids such as lysine and arginine, and ammonia are used. The acyl group of fatty acid diethanolamide, which is the second essential component of the composition of the present invention, has 10 to 10 carbon atoms.
18 can be used. Preferred acyl groups include, for example, residues of fatty acids such as coconut oil fatty acid, lauric acid, and myristic acid. Although fatty acid monoethanolamide has a thickening effect, it has poor cold resistance and is not preferred. The water-soluble inorganic salt used as the third essential component of the composition of the present invention contains cations consisting of Na ⁺ , K ⁺ , NH ⁺ ₄ , and Cl ^- , SO ^2- ₄ , PO ^3- ₄ , CO ^{2 -} at least one type of inorganic salt including an acid salt formed from an anion consisting of ₃ . Examples of these water-soluble inorganic salts include NaCl, Na ₂ CO ₄ , NaHSO ₄ ,
Na ₃ PO ₄ , Na ₂ HPO ₄ , KCl, K ₂ SO ₄ , KHSO ₄ ,
_{K3PO4 , K2HPO4 , KH2PO4 , NH4Cl} ,
(NH ₄ ) ₂ SO ₄ , (NH ₄ ) ₃ PO ₄ , (NH ₄ ) ₂ HPO ₄ ,
Examples include NH ₄ H ₂ PO ₄ . These water-soluble inorganic salts may be used alone or in combination of two or more. The blending ratio of each of these essential components is 35 to 80 wt% N-acyl neutral amino acid water-soluble salt, 5 to 60 wt% fatty acid diethanolamide, and 5 to 5 wt% water-soluble inorganic salt.
60wt%, and the total of each component is 100wt%. Outside this range, the viscosity of the obtained liquid detergent may become low or the cold resistance may deteriorate, which is not preferable. In the composition of the present invention, the total proportion of the above three components contained in the liquid detergent varies depending on the purpose of use and the types of essential components, but is preferably 10 to 35 wt%. If it is less than 10 wt%, foaming and detergency will be insufficient, and if it is more than 35 wt%, cold resistance will be poor, which is not preferable. In order to investigate the cold resistance and viscosity of the composition of the present invention, the following experiments A to C were conducted. Experiment A N-lauroyl-N-methyl-β-alanine sodium salt, coconut oil fatty acid diethanolamide, and sodium chloride were blended in the proportions shown in Figure 1, and the total amount of the three components was adjusted to 25 wt%. The pH was adjusted to 7.0 with citric acid. The viscosity at 25°C and cold resistance of the sample thus obtained were measured. However, the viscosity was measured using a B-type viscometer manufactured by Tokyo Keiki Co., Ltd. For the cold resistance test, the sample was heated to -5°C.
The condition was observed after standing for 7 days and evaluated according to the following judgment. - Criteria for judging cold resistance - 〇... Uniformly transparent △... Slightly cloudy ×... Cloudy or separated The measurement results are shown in Table 1. In addition, in Table 1
No. corresponds to the number in the triangular diagram in FIG. The numbers circled in Table 1 are formulations within the scope of the present invention.

【table】

Claims (1)

[Scope of Claims] 1 A liquid detergent composition containing a N-acyl neutral amino acid water-soluble salt, wherein a N-acyl neutral amino acid water-soluble salt: 35 to
80wt% b Fatty acid diethanolamide: 5-60wt% c Water-soluble inorganic salt: 5-60wt% as essential components (however, the total of a, b, and c is
100wt%). 2. The composition according to claim 1, wherein the neutral amino acid of the water-soluble salt of N-acyl neutral amino acid is selected from sarcosine and N-methyl-β-alanine. 3. The composition according to claim 1, wherein the acyl group of the water-soluble salt of N-acyl neutral amino acid is a saturated or unsaturated fatty acid residue having 10 to 18 carbon atoms. 4. The composition according to claim 1, wherein the cation forming the water-soluble salt of the N-acyl neutral amino acid water-soluble salt is selected from alkali metals, alkanolamines, ammonia, and basic amino acids. 5. The composition according to claim 1, wherein the acyl group of the fatty acid diethanolamide is a fatty acid residue having 10 to 18 carbon atoms. 6 Water-soluble inorganic salts are acidic salts formed from cations consisting of Na ⁺ , K ⁺ , and NH ₄ ⁺ and anions consisting of Cl ^- , SO ^2- ₄ , PO ^3- ₄ , and CO ^2- ₃ . The composition according to claim 1, which contains at least one inorganic salt.