Liquid crystal thickening agent free of fatty acid and application of liquid crystal thickening agent in elution type cosmetics

Abstract

The invention provides a fatty acid-free liquid crystal thickening agent as well as a preparation method and application thereof. The fatty acid-free liquid crystal thickening agent comprises the following components in percentage by mass: 12-17% of hydrogenated castor oil; 10 to 15% of sodium taurine laurate; 5-8% of modified corn starch; 0.3 to 0.8 percent of phenoxyethanol; 59.4% to 72.4% of water; the sum of the mass percentages of the components is 100%. The thickener consists of a fatty acid-free three-component system, and has the characteristics of good stability, excellent touch feeling and easiness in blending with conventional surfactants. After hydrogenated castor oil, sodium taurate, modified corn starch and other components are treated by a proper process, a stable liquid crystal structure can be formed in a water phase system, so that efficient thickening, excellent touch feeling and good compatibility are realized, and the liquid crystal composition is suitable for drip washing type cosmetics.

Description

Technical Field

[0001] This invention relates to the fields of cosmetic formulation and polymer thickening systems, specifically to a fatty acid-free liquid crystal thickener and its application in rinse-off cosmetics. Background Technology

[0002] The thickening systems commonly used in traditional rinse-off cosmetics (such as shampoos and shower gels) mainly include the following categories:

[0003] 1. Inorganic salt thickening system Sodium chloride (NaCl) is the most common inorganic salt thickener, increasing viscosity by enhancing the association of surfactant micelles. Advantages: low cost and simple process; however, excessive use can cause "salting out" (a decrease in viscosity). 2. Polymer Thickening System Xanthan gum: Significantly thickens at low concentrations and exhibits high pH and temperature stability, making it suitable for suspending particles (such as fragrances or colorants in shampoos). Hydroxyethyl cellulose (HEC): Forms a network structure through hydration, suitable for medium to high viscosity requirements. 3. Surfactant-thickener compound system Fatty alcohol polyoxyethylene ethers (such as lauryl polyoxyethylene ether): Synergistically thickening when combined with inorganic salts (such as NaCl), suitable for anionic surfactant systems. Coconut oil diethanolamide: Interacts with anionic surfactant micelles to form non-Newtonian fluids, increasing viscosity. 4. Covalent crosslinking system Acrylic crosslinked polymers (such as Carbomer): These form a three-dimensional network through crosslinking of bifunctional monomers, making them suitable for products requiring high stability. Combinations of various thickeners (such as xanthan gum + hydroxyethyl cellulose) can balance viscosity, suspension properties, and cost.

[0004] If the thickening system commonly used in traditional rinse-off cosmetics contains fatty acids or fatty acid derivatives, it may have adverse effects such as reduced shelf life, skin irritation, and separation of the skin.

[0005] Currently, there are few reports on the functions of thickening systems commonly used in rinse-off cosmetics. Therefore, research on the functions of thickening systems commonly used in rinse-off cosmetics is of great significance. Summary of the Invention

[0006] To address the aforementioned problems, the present invention aims to provide a fatty acid-free liquid crystal thickener and its preparation method. The thickener is composed of a three-component system free of fatty acids and possesses good stability, excellent tactile feel, and easy blendability with conventional surfactants.

[0007] In addition, another objective of the present invention is to provide a method for preparing the above-mentioned fatty acid-free liquid crystal thickener. By using hydrogenated castor oil, sodium taurate laurate, modified corn starch and other components through appropriate processing, a stable liquid crystal structure can be formed in an aqueous system, thereby achieving efficient thickening, excellent touch and good compatibility, and is suitable for rinse-off cosmetics.

[0008] Another object of the present invention is to provide the application of the above-mentioned fatty acid-free liquid crystal thickener in rinse-off cosmetics.

[0009] To solve the above-mentioned technical problems, the present invention adopts the following technical solution.

[0010] A fatty acid-free liquid crystal thickener, comprising the following components by weight percentage: Hydrogenated castor oil: 12-17%; Sodium laurate taurate: 10-15%; Modified corn starch: 5-8%; Phenoxyethanol: 0.3-0.8%; Water: 59.4-72.4%; The sum of the mass percentages of all components is 100%.

[0011] Furthermore, the fatty acid-free liquid crystal thickener of the present invention comprises, by weight percentage, the following components: Hydrogenated castor oil: 15%; Sodium lauryl taurate: 13%; Modified corn starch: 7%; Phenoxyethanol: 0.6%; Water: 64.4%; The sum of the mass percentages of all components is 100%.

[0012] In addition, this invention discloses a method for preparing a fatty acid-free liquid crystal thickener, comprising the following steps: 1) Weigh each component according to the above proportions, preheat the aqueous phase to an appropriate temperature, add phenoxyethanol, stir slowly to make it uniform, then add modified corn starch to form a uniform aqueous paste system. 2) Add hydrogenated castor oil to the aqueous phase at an appropriate rate and continue stirring until a homogeneous emulsion system is formed; 3) Add sodium laurate taurate to the system and continue stirring until the mixture is homogeneous; 4) Cool down and control the crystallization process. After the system reaches the target grain structure and viscosity is stable, add an additional preservative at a suitable temperature. After passing the inspection, fill the finished product.

[0013] Furthermore, the hydrogenated castor oil and sodium laurate taurate work together to form a liquid crystal thickening network, improving the stability and tactile properties of the system.

[0014] Furthermore, the modified corn starch undergoes special modification to enhance its dispersibility and crystal formation ability.

[0015] Furthermore, the aqueous phase is preheated at 70-75°C, and hydrogenated castor oil is slowly added within this temperature range to control the emulsification process and ensure the formation of the liquid crystal phase.

[0016] Furthermore, a stepwise addition of modified corn starch is employed to ensure the formation of a uniform aqueous dispersion system.

[0017] Furthermore, the temperature is lowered to 40-50°C, and crystallization is controlled. Viscosity and stability are checked at 30-35°C, and preservatives are added as needed before final filling. By controlling the cooling rate, the grain size in the system is adjusted, improving the stability and feel of the thickener.

[0018] In addition, the present invention also discloses a rinse-off cosmetic prepared with the above-mentioned liquid crystal thickener, the cosmetic comprising: basic surfactant, moisturizer, preservative and other excipients, wherein the liquid crystal thickener, as a thickening system, imparts excellent suspension, smoothness and easy rinsing properties to the product.

[0019] Furthermore, the system formed by the wash-off cosmetic exhibits good thermal and viscosity stability under different temperature conditions and has a long phase separation time.

[0020] Furthermore, the thickener content in the formulation of the wash-off cosmetic is 1.0%-3.0% to achieve the desired viscosity and feel.

[0021] Furthermore, it can be applied to rinse-off products such as shampoos, shower gels, and facial cleansers to improve the products' lubricity, stability, and ease of rinsing.

[0022] In addition, this invention discloses a shampoo, characterized in that: its base system has the following specific formula by weight percentage: Sodium lauryl sulfate (SLES, an anionic surfactant): 13%; Citrate buffer (used for pH control, containing active salt buffer system): 0.8%; Glycerin (humectant): 2%; The fatty acid-free liquid crystal thickener according to claim 1 or 2: 2.0%; Phenoxyethanol (preservative): 0.6%; Paraben preservatives: 0.15%; Spices: 0.2%; Colorant: 0.1%; Water: up to 100%; Preparation process: Add approximately 80% of the formulation amount of deionized water to a clean main container and heat to 70-75°C; add citrate buffer and stir until completely dissolved; add glycerin and stir evenly; while stirring, slowly add sodium lauryl sulfate (SLES) and stir until completely dissolved and clear; cool the system to 40-45°C, add the fatty acid-free liquid crystal thickener as described in claim 1 or 2, and disperse evenly with medium-speed stirring (approximately 500-800 rpm) to form a homogeneous system; add phenoxyethanol and paraben preservatives (methyl paraben and m-paraben) and stir to dissolve; add fragrance and colorant and stir evenly; add the remaining deionized water to bring the total to 100% and adjust the pH to 5.5-6.5; continue stirring and cooling to room temperature, take samples to check viscosity and appearance, and fill after passing the inspection.

[0023] In addition, this invention discloses a shower gel, characterized in that: its base system has the following specific formula by weight percentage: Plant-based surfactant blend (nonionic / ampholy): 8%; Mild surfactants (such as Cocamidopropyl Betaine, etc.): 4%; The fatty acid-free liquid crystal thickener according to claim 1 or 2: 1.0%; Moisturizers such as glycerin: 2%; Phenoxyethanol: 0.5%; Paraben preservatives: 0.2%; Fragrances and colorants: 0.1% each; Water: up to 100%; Preparation process: Add approximately 85% of the formulation amount of deionized water to a clean main container and heat to 65-70°C; add glycerin and stir to dissolve; while stirring, add the plant-based surfactant mixture and Cocamidopropyl Betaine in sequence, stirring until completely dissolved and clear; cool the system to 40-45°C, add the fatty acid-free liquid crystal thickener as described in claim 1 or 2, and disperse evenly by stirring at medium speed (approximately 500-800 rpm); add phenoxyethanol and paraben preservatives (a combination of methyl, ethyl, and propyl parabens), and stir to dissolve; add fragrance and colorant, and stir evenly; add the remaining deionized water to bring the total to 100%, and adjust the pH to 5.5-6.0; continue stirring and cooling to room temperature, take samples to check viscosity and appearance, and fill after passing inspection.

[0024] By employing the above technical solution, the beneficial effects of the present invention are: 1) The liquid crystal thickener provided by this invention, without the presence of fatty acids, forms a stable liquid crystal structure through the synergistic effect of hydrogenated castor oil, sodium taurate laurate, and modified corn starch, exhibiting good thickening effect, feel and compatibility, and has high degree of compatibility with the formulation of conventional rinse-off cosmetics.

[0025] 2) By comparing the examples and comparative examples, the significant impact of the composition and process of the present invention on the final stability, viscosity retention, grain control and sensory properties can be clearly demonstrated. Detailed Implementation

[0026] The present invention will be further described in detail below through specific preferred embodiments and efficacy test examples, but the present invention is not limited to the following embodiments.

[0027] This invention discloses a fatty acid-free liquid crystal thickener, its preparation method, and its application. By mass percentage, the fatty acid-free liquid crystal thickener comprises the following components: hydrogenated castor oil: 12-17%; sodium taurate laurate: 10-15%; modified corn starch: 5-8%; phenoxyethanol: 0.3-0.8%; water: 59.4-72.4%; the sum of the mass percentages of all components is 100%. The thickener, composed of a fatty acid-free three-component system, exhibits good stability, excellent tactile feel, and easy miscibility with conventional surfactants.

[0028] This invention utilizes hydrogenated castor oil, sodium laurate taurate, modified corn starch, and other components, which, after appropriate processing, can form a stable liquid crystal structure in an aqueous system. This achieves efficient thickening, excellent touch, and good compatibility, and is suitable for rinse-off cosmetics.

[0029] Example 1 A fatty acid-free liquid crystal thickener, the formulation of which comprises the following components (by weight percentage): Hydrogenated castor oil 15%; sodium laurate taurate 13%; modified corn starch 7%; phenoxyethanol 0.6%; water 64.4%.

[0030] Preparation process: Weigh the ingredients according to the above formula. Preheat the aqueous phase to about 70-75°C and add phenoxyethanol, stirring until completely dissolved. Gradually add modified corn starch while stirring at medium speed to form a uniform aqueous paste. Then slowly add hydrogenated castor oil at 70-75°C while stirring. After it becomes smooth, add sodium laurate taurate and continue stirring until compatible. Cool down to 40-50°C and crystallize at a controlled rate. Check the viscosity and stability at 30-35°C and add preservatives as needed. Finally, fill the container.

[0031] Example 2 A fatty acid-free liquid crystal thickener, the formulation of which comprises the following components (by weight percentage): Hydrogenated castor oil 14%; sodium laurate taurate 12%; modified corn starch 6%; phenoxyethanol 0.5%; water 67.5%.

[0032] Preparation process: The same sequence and process as in Example 1 are used, but the cooling step is set to first cool down to 45°C and hold it at that temperature for a short time before slowly cooling down to room temperature, in order to obtain a finer grain structure and improve tactile stability.

[0033] Example 3 A fatty acid-free liquid crystal thickener, the formulation of which comprises the following components (by weight percentage): Hydrogenated castor oil 16%; sodium laurate taurate 11%; modified corn starch 8%; phenoxyethanol 0.4%; water 64.6%.

[0034] Preparation process: Phenoxyethanol and sodium laurate taurate are first dissolved in the aqueous phase, and then modified corn starch is added stepwise to ensure the formation of an efficient aqueous dispersion system. Hydrogenated castor oil is added dropwise at a low rate to control the emulsification intensity and reduce crystal agglomeration. After cooling and completing the crystallization process, the product is filled.

[0035] Example 4 A fatty acid-free liquid crystal thickener, the formulation of which comprises the following components (by weight percentage): Hydrogenated castor oil 13%; sodium laurate taurate 15%; modified corn starch 5%; phenoxyethanol 0.3%; water 66.7%.

[0036] Preparation process: Preheat the aqueous phase to about 70°C and add phenoxyethanol, then add modified corn starch and stir until homogeneous. Add hydrogenated castor oil dropwise in steps, and finally add sodium laurate taurate and continue stirring. Cool to room temperature and gradually crystallize.

[0037] Example 5 A fatty acid-free liquid crystal thickener, the formulation of which comprises the following components (by weight percentage): Hydrogenated castor oil 12%; sodium laurate taurate 14%; modified corn starch 8%; phenoxyethanol 0.8%; water 65.2%.

[0038] Preparation process: Premix all soluble components in the aqueous phase at a relatively high aqueous phase temperature (70-75°C), then slowly add hydrogenated castor oil with medium-speed stirring, and finally gradually disperse sodium laurate taurate into the system. Cool the temperature to 32-38°C to control crystal formation, and fill the system after passing the inspection.

[0039] The following is the content of comparative examples 1-3.

[0040] Comparative Example 1 Formula (by weight percentage): Hydrogenated castor oil: 20%; Sodium laurate taurate: 12%; Phenoxyethanol: 0.5%; Water: 67.5%; Note: Modified corn starch, a thickening component, was removed to verify the changes in viscosity and stability of the system in the absence of a core thickening matrix.

[0041] Comparative Example 2 Formula (by weight): Hydrogenated castor oil: 13%; Sodium laurate taurate: 10%; Modified corn starch: 4%; Water: 73%; Note: Phenoxyethanol (a component in the preservative system) was removed to evaluate the stability and usability of the system without this preservative component.

[0042] Comparative Example 3 Formula (by weight): Sodium laurate taurate: 11%; Modified corn starch: 8%; Hydroxyethyl cellulose (HEC, a substitute for fatty acid-free high molecular weight thickener): 4%; Phenoxyethanol: 0.4%; Water: 76.6%; Note: In the non-fatty acid liquid crystal thickener system, hydrogenated castor oil was removed and replaced with a non-fatty acid polymeric thickener (such as HEC) to investigate the feasibility and compatibility of the non-fatty acid thickening system.

[0043] In addition, the following will describe examples of the application of the present invention in rinse-off cosmetics.

[0044] Application Example 1 (The shampoo uses a concentrated formula with a thicknessing agent content of 2.0%) The specific formula (by weight) for the basic system is as follows: Sodium lauryl sulfate (SLES, an anionic surfactant): 13%; Citrate buffer (used for pH control, containing active salt buffer system): 0.8%; Glycerin (humectant): 2%; Example 1: Fatty acid-free liquid crystal thickener (component of this invention, content 2.0%): the core thickening system of this example; Phenoxyethanol (preservative): 0.6%; Paraben preservatives (a combination of methyl parabens and m-parabens, totaling 0.15%). Spices: 0.2%; Colorant: 0.0–0.1%; Water: up to 100%; Preparation process: Add approximately 80% of the formula amount of deionized water to a clean main container and heat to 70°C.

[0045] Add citrate buffer and stir until completely dissolved.

[0046] Add glycerin and stir well.

[0047] While stirring, slowly add sodium lauryl sulfate (SLES) and stir until completely dissolved and clear.

[0048] Cool the system to 40°C, add the fatty acid-free liquid crystal thickener from Example 1, and disperse it evenly by stirring at medium speed (about 500-800 rpm) to form a homogeneous system.

[0049] Add phenoxyethanol and paraben preservatives (methyl paraben and m-paraben), and stir to dissolve.

[0050] Add spices and colorings, and mix well.

[0051] Make up the total volume with the remaining deionized water to 100%, and adjust the pH to 5.5-6.5.

[0052] Continue stirring and cooling to room temperature. Take a sample to check the viscosity and appearance. If it passes the test, fill the container.

[0053] In summary, this formula forms a stable liquid crystal thickening network in the SLES system, improving smoothness and ease of rinsing, while also exhibiting good compatibility and storage stability.

[0054] Application Example 2 (Formula for shower gel, thicknessing agent content 1.0%) The specific formula of the basic system (by mass percentage): Plant-based surfactant blend (nonionic / ampholy): 8%; Mild surfactant (Cocamidopropyl Betaine): 4%; Example 2: Fatty acid-free liquid crystal thickener (component of this invention, content 1.0%): 1.0%; Moisturizers such as glycerin: 2%; Phenoxyethanol: 0.5%; Paraben preservatives (combination of methyl, ethyl, and propyl parabens): 0.2%; Fragrances and colorants: 0.2% each; Water: up to 100%; Preparation process: Preheat the aqueous phase at 70°C, add phenoxyethanol and paraben preservatives and stir until completely dissolved; After mixing the plant-based surfactant with the mild surfactant, the mixture was gradually added to the aqueous phase and stirred until it was uniformly suspended. The liquid crystal thickener of Example 2 of the present invention was slowly added dropwise while stirring at a medium speed to ensure sufficient dispersion and prevent the formation of large particle agglomeration. The temperature was lowered to 40°C to control crystal formation, and the viscosity change curve with temperature was recorded. Further cool to 20°C at room temperature, check stability and sensory properties, and adjust the preservative ratio or pH if necessary before filling.

[0055] This embodiment achieves liquid crystal thickening in a nonionic / amphoteric surfactant system, which combines good touch and easy rinsing, and also has a certain moisturizing effect.

[0056] Efficacy Test Example 1 Physical properties and stability evaluation Objective: To evaluate the viscosity, rheological behavior, thermal stability and system homogeneity of the fatty acid-free liquid crystal thickener of the present invention in an aqueous system.

[0057] Materials and Samples: Samples and control systems containing the thickener of this invention were prepared, and the process was repeated 3 times.

[0058] Test methods and conditions: Viscosity measurement: The viscosity was measured using a Brookfield viscometer at 25°C, 600 rpm, and 50 rpm. The shear thinning behavior was recorded, and the average value and standard deviation were taken.

[0059] Viscosity-temperature relationship: Viscosity was measured at 4°C and 40°C, and viscosity-temperature curves were plotted to evaluate temperature stability.

[0060] Stability test: Perform centrifugation stability test (e.g., 1000 rpm × 30 min) and observe the phase separation time and phenomena. Record the layer height if necessary.

[0061] Aesthetic and structural observation: Visually observe the stability of the appearance and the distribution of grains (if necessary, use a polarizing microscope for preliminary observation).

[0062] Evaluation indicators: viscosity range, rheological index, shear thinning degree, phase separation time, appearance stability, and grain distribution.

[0063] Data processing: Calculate the mean and variance of the repeated samples, compare the stability differences between the component system of this invention and the control group, and use a simple t-test to determine statistical significance.

[0064] Table 1: Data Recording Table for Physical Properties and Stability Evaluation

[0065] As shown in Table 1, regarding viscosity and rheological behavior: all embodiments of the present invention (1-5) exhibited significantly higher viscosity than the comparative examples at both high and low shear rates, and had smaller rheological indices (n), indicating stronger shear-thinning behavior (pseudoplasticity), which is more conducive to product extrusion and spreading. Example 3 (with the highest hydrogenated castor oil content) exhibited the highest absolute viscosity.

[0066] Temperature stability: The embodiments of the present invention exhibited viscosity retention rates of over 90% at both 4°C and 40°C, demonstrating excellent temperature stability. Comparative Example 1 (starch-free) and Comparative Example 3 (hydrogenated castor oil-free) showed poorer temperature stability.

[0067] Physical stability: In the embodiments of this invention, no stratification or only slight opalescence was observed after centrifugation, and the appearance remained stable during accelerated testing. The comparative examples all showed varying degrees of stratification or precipitation.

[0068] Microstructure: The crystal grains in the embodiments of the present invention are fine and uniform (diameter 15-50μm), and the finest crystal grains (15-35μm) are obtained in Example 2 due to a special cooling process. Comparative Example 1 has coarse crystal grains, and Comparative Example 3 has no typical liquid crystal structure.

[0069] Efficacy test example 2 Preliminary evaluation of sensory properties and cleanliness Objective: To evaluate the sensory attributes of shampoo and body care products, such as lubrication, rinsing ease, foaming, and cleansing properties, under subject conditions.

[0070] Subjects and grouping: Twenty subjects were recruited and randomly divided into two groups: a sample group containing the thickener of the present invention (Application Example 2) and a control sample group.

[0071] Control sample group: A shower gel sample with the same basic formulation as Application Example 2, but without any of the thickeners of this invention, and with the addition of 0.8% hydroxyethyl cellulose (HEC) as a conventional thickener. Preparation: HEC was dispersed in a portion of water at room temperature to swell before the other components were added.

[0072] Test method: Use a simplified sensory rating scale to rate the following sub-items: wetness, lubricity, ease of rinsing, foam richness, cleanliness, and residue (1-5 points, 5 points being the best).

[0073] Each participant underwent a blind test on two samples, and a comprehensive score and usage preference were given after comparison.

[0074] Use the simplified soil removal test to assess cleaning effectiveness and record the area cleaned and the number of rinses required.

[0075] Evaluation metrics: overall sensory score, repurchase intention, and skin feel and comfort after use.

[0076] Data analysis: Paired t-tests were used to compare the significant differences in sensory scores between the two groups, and the p-values ​​were statistically analyzed; the differences in average stain removal rate and number of rinses in the stain removal test were summarized.

[0077] Table 2: List of Sensory and Cleanliness Evaluation Data

[0078] Table 2 shows that shampoos containing the liquid crystal thickener of this invention exhibit excellent lubricity, rich lather, easy rinsing, and a soft skin feel. The control group had relatively lower sensory scores and noticeable residue. Statistical analysis shows that the liquid crystal thickener significantly improves the sensory performance of the product (P<0.05).

[0079] Synergistic effect experiment example Synergistic effect with other thickening systems Experimental Design: Sample group A: Only the liquid crystal thickener system of the present invention without fatty acids was used (fixed content, such as 2.0%).

[0080] Sample Group B: Only the control thickener system (such as hydroxyethyl methyl cellulose or hydroxyethyl cellulose, sodium taurate lauryl laurate, etc., adjusted according to equivalent viscosity) was used.

[0081] Sample group C: The thickener of the present invention and the control thickener are mixed in a certain proportion (for example, 1.0% of the thickener of the present invention + 0.4% of the control thickener).

[0082] Shampoo system: (mass percentage) Sodium lauryl sulfate (SLES) 13.0%, citrate buffer 0.8%, glycerin 2.0%, liquid crystal thickener A / B / C 2.0%, phenoxyethanol 0.6%, methyl paraben 0.1%, m-paraben 0.05%, fragrance 0.2%, colorant 0.05%, water 81.15%.

[0083] Preparation steps: Aqueous phase preparation: Add approximately 70% of the formula amount of deionized water to a clean main container and heat to 75°C.

[0084] Dissolve buffer and humectant: Add citrate buffer and glycerin, and stir until completely dissolved.

[0085] Dissolving the main surfactant: While stirring, slowly add sodium lauryl sulfate (SLES) and stir until completely dissolved and clear to obtain a uniform and transparent substrate.

[0086] Cooling and thickening agent addition: Cool the above base to 40°C.

[0087] For sample group A: 2.0% of the thickener of the present invention was added (Example 1).

[0088] For sample group B: Add a control thickener (a mixture of 1.2% hydroxyethyl cellulose and 0.8% sodium laurate taurate) that has been determined in preliminary experiments to provide an initial viscosity similar to that of sample group A.

[0089] For sample group C: 1.0% of the thickener of the present invention (Example 1) and 0.4% hydroxyethyl cellulose were added.

[0090] Dispersion and homogenization: Disperse the thickener evenly with medium-speed stirring (about 1000 rpm). If necessary, homogenize briefly (to avoid excessive shearing that could damage the structure) to form a homogeneous system.

[0091] Add preservative system: Add phenoxyethanol, methyl paraben and m-paraben, and stir to dissolve.

[0092] Add flavorings and colorings: Add flavorings and colorings, and stir well.

[0093] Volume adjustment and post-treatment: Add the remaining deionized water to bring the volume to 100%, and adjust the pH to 5.5-6.5. Continue to stir slowly and cool to room temperature (<30°C).

[0094] Curing and testing: After standing for 24 hours, samples were taken for various performance tests.

[0095] Measurement method: In shampoo systems with the same base, viscosity-shear rate curves were measured for three groups (25°C, 10–1000 s⁻¹ range).

[0096] Record the helical viscoelastic parameters (such as G', G'', and the response from small deformation to large deformation).

[0097] Determine phase separation time and grain distribution (e.g., statistical analysis of grain diameter under a microscope).

[0098] Evaluation indicators and efficacy explanations: Synergy coefficient (e.g., the ratio of theoretical summation to measured value) indicates synergistic effect if the viscosity of group C is significantly higher than the theoretical summation value of A+B.

[0099] The combined effects of improved tactile feel, more uniform grain distribution, and enhanced compatibility were observed.

[0100] The conclusions will be given based on a comprehensive set of indicators, including the increase in viscosity, the improvement in helical viscoelasticity, and the degree of improvement in tactile feel.

[0101] Table 3: Comparative Analysis of Viscosity and Grain Distribution

[0102] Conclusion: Application examples show that the fatty acid-free liquid crystal thickener of the present invention can achieve stable thickening, good feel and easy rinsing in rinse-off cosmetics, and has good storage stability; through synergistic effects experiments, it can be shown that there is potential for modification and optimization when combined with other thickeners or surfactants.

[0103] The liquid crystal thickener of this invention exhibits superior thickening, stabilizing, and sensory properties in various aqueous systems, outperforming traditional systems. Through comparison with control systems at various proportions, and innovative optimization of stability and crystal fineness, it facilitates widespread application in diverse rinse-off cosmetics, enabling the development of high-quality, more stable products.

[0104] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Therefore, any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A liquid crystal thickening agent free of fatty acids, characterized in that: By mass percentage, it is made of the following components: Hydrogenated castor oil: 12-17%; Sodium lauryl sulfate: 10-15%; Modified corn starch: 5-8%; Phenoxy ethanol: 0.3-0.8%; Water: 59.4-72.4%; The sum of the mass percentages of each component is 100%.

2. The liquid crystal thickener without fatty acid of claim 1, wherein: By mass percentage, it is made of the following components: Hydrogenated castor oil: 15%; Sodium lauryl sulfate: 13%; Modified corn starch: 7%; Phenoxy ethanol: 0.6%; Water: 64.4%; The sum of the mass percentages of each component is 100%.

3. A process for the preparation of a liquid crystalline thickener free of fatty acids according to claim 1 or 2, characterized in that, It includes the following steps: 1) Weigh each component according to the above ratio, first preheat the water phase to the appropriate temperature, then add phenoxy ethanol, slowly stir to make it uniform, then add modified corn starch and form a uniform water phase paste system; 2) Add hydrogenated castor oil to the water phase at an appropriate rate and continue stirring until a uniform emulsion system is formed; 3) Add sodium lauryl sulfate to the system and continue stirring until it is uniformly compatible; 4) Cool down and control the crystallization process, and after the system reaches the target crystal structure and viscosity is stable, fill the finished product after inspection.

4. The process for the preparation of a liquid crystal thickener free of fatty acids according to claim 3, characterized in that: In step 1), the water phase temperature is 70-75°C.

5. The process for preparing a liquid crystal thickener free of fatty acids according to claim 3, characterized in that, In step 2), then add hydrogenated castor oil at a medium speed under 70-75°C.

6. The process for preparing a liquid crystal thickener free of fatty acids according to claim 3, wherein In step 4), cool down to 40-50°C, control the speed of crystallization; check the viscosity and stability at 30-35°C and supplement the preservative, and finally fill.

7. Use of a liquid-crystalline thickening agent free of fatty acids for the preparation of a rinse-off cosmetic, characterized in that, The cosmetic formula includes: base surfactant, moisturizer, preservative and other auxiliary materials, and the liquid crystal thickening agent as a thickening system.

8. Use according to claim 7, wherein: The amount of thickening agent in the formula of the elution type cosmetic is 1.0%-3.0%.

9. A shampoo, characterized by: The specific formula of its base system by mass percentage: Sodium lauryl sulfate: 13%; Citrate buffer: 0.8%; Glycerin: 2%; Fatty acid-free liquid crystal thickening agent of claim 1 or 2: 2.0%; Phenoxy ethanol: 0.6%; Paraben preservative 0.15%; Fragrance: 0.2%; Colorant: 0.1%; Water: to 100%; Preparation process: Add about 80% of the formula amount of deionized water to a clean main container, heat to 70-75°C; add citrate buffer, stir until completely dissolved; add glycerin and stir evenly; under stirring, slowly add sodium lauryl sulfate (SLES), stir until completely dissolved and clear; cool the system to 40-45°C, add the fatty acid-free liquid crystal thickening agent of claim 1 or 2, disperse evenly at medium speed (about 500-800 rpm) to form a uniform system; add phenoxy ethanol and paraben preservatives (methyl paraben and m-paraben), stir to dissolve; add fragrance and colorant, stir evenly; make up to 100% with the remaining deionized water, adjust the pH to 5.5-6.5; continue stirring to room temperature, check the viscosity and appearance of the sample, and fill after passing the inspection.

10. A body wash characterized by: The specific formula of its base system by mass percentage: Plant-based surfactant mixture (nonionic / amphoteric): 8%; Mild surfactant: 4%; Liquid crystal thickening agent without fatty acid according to claim 1 or 2: 1.0%; Moisturizing agent such as glycerin: 2%; Phenoxyethanol: 0.5%; Paraben preservative: 0.2%; Fragrance, colorant: each 0.1%; Water: to 100%; Preparation process: In a clean main container, add about 85% of the formula amount of deionized water, heat to 65-70℃; add glycerin, stir to dissolve; under stirring, add the plant-based surfactant mixed system and Cocamidopropyl Betaine in turn, stir until completely dissolved and clear; cool the system to 40-45℃, add the liquid crystal thickening agent without fatty acid according to claim 1 or 2, disperse uniformly at medium speed stirring (about 500-800rpm); add phenoxyethanol and paraben preservative (combination of methyl, ethyl, propyl p-hydroxybenzoate), stir to dissolve; add fragrance and colorant, stir uniformly; make up to 100% with the remaining deionized water, adjust pH to 5.5-6.0; continue stirring and cooling to room temperature, take samples to check viscosity and appearance, and pack after passing the inspection.

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