An amino acid surfactant self-thickening composition, its preparation method and use

Abstract

This invention relates to the field of surfactant composition technology, specifically to an amino acid surfactant self-thickening composition, its preparation method, and its application. The composition comprises an amino acid surfactant, cocamidopropyl betaine, sodium lauryl glucoside crosspolymer, PEG-120 methyl glucodioleate, and cocamide MEA, among other components. Through a specific ratio and synergistic effect, it maintains transparency and stability, controllable viscosity, and does not reduce cleaning ability even under low pH and high salt conditions. This invention is applicable to detergent products and features simple preparation, controllable cost, and superior performance.

Description

Technical Field

[0001] This invention relates to the field of surfactant composition technology, specifically to an amino acid surfactant self-thickening composition, its preparation method, and its application. Background Technology

[0002] Amino acid surfactants are typically prepared by neutralizing fatty acids with carbon chains of C8-18 linked to amino acids via amide bonds. Due to their unique molecular structure, these surfactants possess excellent safety and are widely used in various high-end detergent products. However, it is precisely this rigid amide bond structure and stout shape that leads to significant steric hindrance and charge repulsion in their molecules, making it difficult to form effective rod-shaped micelles for thickening. This has become a common technical challenge in detergent product formulation development.

[0003] Currently, thickening solutions for amino acid surfactant systems mainly fall into the following two categories: (1) Adding polymer thickeners (such as PEG-120 methyl glucoside ester, acrylic (ester) copolymers, hydroxyethyl cellulose, etc.): This method requires a significant amount of addition to be effective, which not only greatly increases the cost of raw materials, but also has an adverse effect on the foam height and stability of the product.

[0004] (2) Compounding with a high proportion of zwitterionic surfactants (such as cocamidopropyl betaine): Thickening is achieved by forming mixed micelles through charge shielding, but this will lead to a significant decrease in the product's cleaning ability and user experience. More importantly, if efficient thickening is to be achieved, the core surfactant needs to be replaced, causing the product to change from an "amino acid type" to a "zwitterionic type", which obviously deviates from the original intention of product development.

[0005] Therefore, achieving self-thickening of amino acid surfactants while significantly reducing the amount of polymer thickeners and fully preserving the cleaning efficacy and essential properties of amino acid surfactants is currently a technological bottleneck for amino acid surfactants. Summary of the Invention

[0006] To address the technical bottlenecks of existing technologies, this invention provides an amino acid surfactant self-thickening composition, its preparation method, and its application.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: In a first aspect, the present invention provides an amino acid surfactant self-thickening composition, comprising the following components by weight: Amino acid surfactant, 5-15 parts; Cocamidopropyl betaine, 2.5-8 parts; Sodium lauryl glucoside crosspolymer sulfonate, 0.01-3 parts; PEG-120 methyl glucoside, 0.01-1 part; Cocamide MEA, 0.01-1 part; Citric acid, in appropriate amount; Sodium chloride, appropriate amount; Citric acid and water, balance; citric acid is used to adjust the pH of the composition to 4-7.

[0008] The present invention provides an amino acid surfactant self-thickening composition that, through the synergistic effect of specific components and ratios, maintains transparency and stability, controllable viscosity, and does not reduce cleaning ability under low pH and high salt conditions.

[0009] Furthermore, the amino acid surfactant is selected from one or more of sodium lauroyl sarcosinate, sodium cocoyl alanine, sodium methyl cocoyl taurate, and sodium cocoyl methyl taurate.

[0010] Furthermore, the mass ratio of the amino acid surfactant to cocamidopropyl betaine is 5:1 to 6:5.

[0011] Furthermore, the mass ratio of PEG-120 methyl glucoside ester to cocoamide MEA is 3:1 to 1:3.

[0012] Furthermore, the viscosity of the composition at 25°C is 2000-110000 mPa·s.

[0013] Furthermore, the composition showed no precipitation at 5°C.

[0014] Secondly, the present invention provides a method for preparing the aforementioned amino acid surfactant self-thickening composition, comprising the following steps: Weigh out water, amino acid surfactant, cocamidopropyl betaine, sodium lauryl glucoside crosspolymer, PEG-120 methyl glucodioleate, and cocamidopropyl MEA according to the specified ratio, and stir and heat until completely dissolved. Add citric acid to adjust the pH to the target value; Add sodium chloride and stir until homogeneous to obtain the composition.

[0015] Thirdly, the present invention provides the use of the composition in the preparation of detergent products.

[0016] The present invention has the following beneficial effects: Thickening effect: By shielding part of the electrostatic repulsion through a small amount of zwitterionic ions (such as cocamidopropyl betaine), it forms mixed micelles with amino acid surfactants; by embedding cocamidopropyl betaine into the micelles, the ratio of hydrophobic chain volume to hydrophilic head group area and hydrophobic chain length is increased, compensating for steric hindrance and improving the tightness of micelle binding; by connecting spherical and / or mixed micelles in series with PEG-120 methyl glucoside dioleate and sodium lauryl glucoside sulfonate crosspolymer, a "pearl chain" is formed, thereby achieving self-thickening.

[0017] No precipitation under low pH / high salt: After the above "pearl chain" is formed, due to the more compact and numerous micelle structure, the surfactant that should have precipitated due to high salt / low pH is incorporated into the micelle and dissolved, which further increases the micelle volume and compactness and thus increases the viscosity of the system.

[0018] This invention achieves self-thickening of amino acid surfactants with low addition amounts of polymer and appropriate amounts of zwitterionic surfactants through the synergistic effect of specific components and ratios, maintaining the "amino acid type" nature of the product and possessing good cleaning ability, low irritation and high and low temperature stability. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the samples in Example H, Example E, Example J, Example L, and Example M at 5°C.

[0020] Figure 2 The above are schematic diagrams of the samples at 5℃ for Comparative Examples 2, 4, 6, 7, 9, 10, 11, and 12.

[0021] Figure 3 This is a standard curve for the solubility-absorbance of zein. Detailed Implementation

[0022] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments, but this should not be construed as limiting the invention. Unless otherwise specified, the technical means used in the following embodiments are conventional means well known to those skilled in the art, and the materials, reagents, etc. used in the following embodiments are commercially available unless otherwise specified.

[0023] Examples 1-13 Weigh each component according to the formulation shown in Table 1 to prepare composition AM. The specific steps are as follows:

[0024] 1. Add water, amino acid surfactant, cocamidopropyl betaine, sodium lauryl glucoside crosspolymer, PEG-120 methyl glucoside dioleate, and cocamidopropyl betaine to a reaction vessel, stir and heat until completely dissolved; 2. Add citric acid to adjust the pH to the target value; 3. Add sodium chloride and continue stirring until homogeneous to obtain a transparent gel-like composition.

[0025] Table 1 AM Group Formulation in Examples Comparative Examples 1-12 Control compositions 1-12 were prepared according to the formulations shown in Table 2, following the same steps as in the examples.

[0026] Table 2 Formulations of Comparative Examples 1-12 Performance testing: Viscosity determination: Measured using a rotational viscometer at 25°C; Low temperature stability: Place at 5℃ for 24 hours and observe whether precipitation occurs; Protein solubility: (1) To construct a standard curve, prepare 0.08g, 0.16g, 0.24g, 0.4g, and 0.8g of zein protein, dissolve them in ethanol, and bring the volume to 50ml. Measure the absorbance at 470nm. (2) Take a 1% solution, add 0.3g of zein protein, sonicate for 30min, and measure the absorbance. Calculate the absorbance according to the standard curve. Figure 3 Calculate the solubility.

[0027] Test results: As shown in Table 3, Table 4 and Figure 1 , Figure 2 The results show that the viscosity of AM in Example 1 ranged from 2133 to 107900 mPa·s at 25°C, with no precipitation at 5°C, and the protein solubility was between 26.45% and 63.06%, indicating good mildness and low-temperature stability. The viscosities of Comparative Examples 1-12 were generally below 620 mPa·s, and most showed precipitation at low temperatures, indicating that their overall mildness was inferior to that of Example 1.

[0028] Table 3 Test Results of the Formulations in the Examples Table 4. Test results of the comparative formulation It should be noted that when numerical ranges are mentioned in the claims of this invention, it should be understood that the two endpoints of each numerical range and any value between the two endpoints can be selected. To avoid redundancy, the present invention describes preferred embodiments.

[0029] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

Claims

1. A self-thickening composition using an amino acid surfactant, characterized in that, By weight, each 100 parts of the composition comprises the following components: Amino acid surfactant, 5-15 parts; Cocamidopropyl betaine, 2.5-8 parts; Sodium lauryl glucoside crosspolymer sulfonate, 0.01-3 parts; PEG-120 methyl glucoside, 0.01-1 part; Cocamide MEA, 0.01-1 part; Sodium chloride, 0-3 parts; Citric acid and water, balance; citric acid is used to adjust the pH of the composition to 4-7.

2. The composition according to claim 1, characterized in that, The amino acid surfactant is selected from one or more of sodium lauroyl sarcosinate, sodium cocoyl alanine, sodium methyl cocoyl taurate, and sodium cocoyl methyl taurate.

3. The composition according to claim 1, characterized in that, The mass ratio of the amino acid surfactant to cocamidopropyl betaine is 5:1 to 6:

5.

4. The composition according to claim 1, characterized in that, The mass ratio of PEG-120 methyl glucoside ester to cocoamide MEA is 3:1 to 1:

3.

5. The composition according to claim 1, characterized in that, The viscosity of the composition at 25°C is 2000-110000 mPa·s.

6. The composition according to claim 1, characterized in that, The composition showed no precipitation at 5°C.

7. A method for preparing a self-thickening composition of an amino acid surfactant according to any one of claims 1-6, characterized in that, Includes the following steps: Weigh out water, amino acid surfactant, cocamidopropyl betaine, sodium lauryl glucoside crosspolymer, PEG-120 methyl glucodioleate, and cocamidopropyl MEA according to the specified ratio, and stir and heat until completely dissolved. Add citric acid to adjust the pH to the target value; Add sodium chloride and stir until homogeneous to obtain the composition.

8. The use of the composition according to any one of claims 1-6 in the preparation of detergent products.

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