Preparation process of soothing bidirectional milk body mask

Abstract

The present application relates to the technical field of face mask, in particular to a soothing bidirectional cream mask preparation process, which comprises the following steps: weighing caprylic acid / capric acid triglyceride, hydrogenated polyisobutylene, glycerol, carbomer, esterified ceramide precursor, lignin-cellulose nanocrystal, gynura extract, beta-glucan, dipotassium glycyrrhizinate and sorbitan olivate; adding the oil phase into the water phase, homogenizing to obtain a primary emulsion, then adding the lignin-cellulose nanocrystal dispersion solution, cooling to 60 DEG C, adding the esterified ceramide precursor, continuing to cool to 40-45 DEG C, adding the arginine solution and carbomer, further cooling to 35-38 DEG C, adding the gynura extract, beta-glucan and dipotassium glycyrrhizinate, stirring to obtain a paste, finally defoaming in a vacuum defoaming machine, filling and aging to obtain the soothing bidirectional cream mask. The present application can solve the problem that the conventional active substance adding method is prone to interface competition with the stable system, thereby affecting the stability of the emulsion.

Description

Technical Field

[0001] This invention relates to the field of facial mask technology, and more specifically, to a process for preparing a soothing two-way emulsion facial mask. Background Technology

[0002] As an important step in daily skincare, the formulation and texture of face masks directly affect the user experience and efficacy. In recent years, two-way emulsion technology has provided a new direction for face mask innovation. This technology aims to prepare a new type of formulation that appears as a solid or semi-solid paste but can instantly transform into a liquid emulsion after application and massage, thus combining the high carrying capacity of a paste with the light texture of an emulsion.

[0003] However, existing two-way emulsion technology still has significant limitations; in order to achieve soothing and repairing effects, the formula needs to add high concentrations of active ingredients, but conventional methods of adding active ingredients are prone to interfacial competition with the stable system, affecting the stability of the emulsion. In view of this, we propose a soothing two-way emulsion mask preparation process. Summary of the Invention

[0004] The purpose of this invention is to provide a soothing two-way emulsion mask preparation process to solve the problem mentioned in the background art that, in order to achieve soothing and repairing effects, the formula needs to add a high concentration of active ingredients, but conventional methods of adding active ingredients are prone to interfacial competition with the stable system, affecting the stability of the emulsion.

[0005] This invention provides a process for preparing a soothing two-way emulsion facial mask, comprising the following steps:

[0006] S1.1 Weigh the following raw materials: caprylic / capric triglyceride, hydrogenated polyisobutylene, glycerol, carbomer, esterified ceramide precursor, lignin-cellulose nanocrystals, Centella asiatica extract, β-glucan, dipotassium glycyrrhizate, sorbitan oleate.

[0007] S1.2 Add the oil phase to the aqueous phase through a filter screen, maintain the temperature at 75℃, and homogenize with a high-speed homogenizer at a speed of 5000-8000 rpm for 3-5 minutes to obtain the primary emulsion.

[0008] S1.3 Add the lignin-cellulose nanocrystal dispersion to the primary emulsion, stir at 200-400 rpm, and begin cooling. When the temperature drops to 60℃, add the esterified ceramide precursor and continue stirring and cooling. When the temperature drops to 40-45℃, neutralize the carbomer with 0.01 mol / L arginine solution to a pH of 6.0-7.0. When the temperature drops to 35-38℃, add Centella asiatica extract, β-glucan, and dipotassium glycyrrhizate, and stir at 200 rpm for 10-15 min to obtain the paste.

[0009] S1.4 Remove air bubbles from the prepared cream in a vacuum degassing machine, fill it, and then age it at room temperature for 24 hours to obtain a soothing two-way emulsion mask.

[0010] Preferably, in step S1.1, the following raw materials are weighed in parts by weight: 3-8 parts by weight of caprylic / capric triglyceride, 1-3 parts by weight of hydrogenated polyisobutylene, 15-20 parts by weight of glycerol, 0.1-0.3 parts by weight of carbomer, 1-5 parts by weight of esterified ceramide precursor, 5-10 parts by weight of lignin-cellulose nanocrystals, 3-5 parts by weight of Centella asiatica extract, 0.5-1.0 parts by weight of β-glucan, 0.1-0.3 parts by weight of dipotassium glycyrrhizate, and 0.5-1.5 parts by weight of sorbitan oleate.

[0011] Preferably, in step S1.2, the oil phase is obtained by adding caprylic / capric triglyceride, hydrogenated polyisobutylene and sorbitan olive oil ester to an oil phase pot, heating to 70-75°C, and stirring at 300-400 rpm until completely dissolved;

[0012] The aqueous phase is prepared by adding deionized water, glycerol, and carbomer to an aqueous phase pot, heating to 75-80℃, and stirring at 400-500 rpm for 20 minutes until the carbomer is completely swollen.

[0013] Preferably, in step S1.3, the lignin-cellulose nanocrystal dispersion is obtained by dispersing lignin-cellulose nanocrystals in deionized water at a mass ratio of 1:100 and pre-dispersing them in a high-speed homogenizer at a speed of 10,000 rpm for 3-5 minutes.

[0014] Preferably, the preparation method of the lignin-cellulose nanocrystals is as follows:

[0015] Dry lignin was dispersed in anhydrous toluene at a mass ratio of 1:15 and stirred at 300-400 rpm. Stearic acid and 4-dimethylaminopyridine were added sequentially to obtain a mixture.

[0016] Under nitrogen protection and cooling in an ice-water bath at 0-5℃, N,N'-dicyclohexylcarbodiimide was added dropwise to the mixture; after the addition was complete, the ice bath was removed, the reaction system was heated to 50-60℃, and the reaction was stirred continuously for 24-48 hours.

[0017] After the reaction is complete, the reaction solution is cooled to room temperature, filtered, and evaporated to concentrate to 1 / 3 of the original volume to obtain a concentrated solution.

[0018] The concentrate was added dropwise to 10 times its volume of n-hexane to precipitate lignin; the precipitate was collected by centrifugation at 8000 rpm, washed 2-3 times with n-hexane, and freeze-dried to obtain partially hydrophobic lignin.

[0019] A portion of the hydrophobic lignin powder was dispersed in isopropyl octanoate at a mass ratio of 1:20. The mixture was then ultrasonically destroyed for 2-3 minutes at 200W in a 40°C water bath to form a hydrophobic lignin-oil solution.

[0020] A hydrophobic lignin-oil solution was added to a 0.5-1.0 wt% cellulose nanocrystal dispersion, homogenized at 10,000-15,000 rpm for 3-5 min using a high-speed homogenizer, and emulsified at room temperature to form an emulsion.

[0021] The emulsion was transferred to a reaction flask, and (3-glycidoxypropyl)trimethoxysilane was added. The mixture was stirred at 200 rpm at 50-60 °C for 6-12 h. After the reaction, 3 times the volume of acetone was added to the emulsion to break the emulsion. The solid particles were collected by high-speed centrifugation at 10000-15000 rpm for 20-30 min.

[0022] The precipitate was washed repeatedly 3-4 times with a 1:1 acetone / ethanol mixed solvent, and finally washed once with pure water by centrifugation. Then, it was freeze-dried at -50℃ for 24 hours to obtain lignin-cellulose nanocrystals.

[0023] Preferably, the amount of stearic acid added is 10-20% of the lignin content;

[0024] The amount of 4-dimethylaminopyridine added is 5% of the lignin content.

[0025] Preferably, the amount of N,N'-dicyclohexylcarbodiimide added is 75-100% of the lignin quality;

[0026] The amount of (3-glycidoxypropyl)trimethoxysilane added is 5-10% of the lignin content.

[0027] Preferably, in step S1.3, the preparation method of the esterified ceramide precursor is as follows:

[0028] In a dry reaction flask, add ceramide and dry isopropanol, heat to 40-50℃ under nitrogen protection, and stir at 200-300 rpm to obtain a ceramide solution of 0.05-0.1 mol / L.

[0029] Add dried vinyl lauryl ester, activated molecular sieve and immobilized enzyme sequentially to the ceramide solution, seal, maintain the temperature at 40-50℃, and stir at 100-200 rpm for 24-48 h.

[0030] After the reaction is complete, cool the reaction solution to room temperature; first, use a Buchner funnel for coarse filtration, and then filter it through a neutral alumina column with a particle size of 100-200 mesh, and collect filtrate A;

[0031] Filtrate A was subjected to vacuum distillation at 40°C to obtain crude product; the crude product was dissolved in anhydrous ethanol at 4°C, crystallized at -20°C for 4 hours and then filtered under vacuum to collect filtrate B.

[0032] The filtrate B was distilled again under reduced pressure and dried at -40 to -60°C for 18-24 hours to obtain the esterified ceramide precursor.

[0033] Preferably, the amount of vinyl lauryl ester added is 2.5-3.5 times the molar equivalent of ceramide;

[0034] The amount of immobilized enzyme added accounts for 20-25% of the mass of ceramide;

[0035] The amount of activated molecular sieve added is 50-80% of the mass of ceramide, and the molecular sieve needs to be activated at 200℃ for 4 hours before use.

[0036] Preferably, in step S1.4, the vacuum degree of the degassing machine is -0.09 to -0.10 MPa, and the degassing time is 10-15 min.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0038] In the soothing two-way emulsion mask preparation process of this invention, the esterified ceramide precursor remains stable during storage. After application, it can be specifically hydrolyzed by esterases on the skin surface, continuously releasing active ceramides, thereby precisely and gradually repairing the skin barrier. This avoids the instantaneous saturation and waste that may result from the direct addition of conventional ceramides, significantly improving the utilization rate of the ingredients and the long-lasting repair effect. As a natural two-sided emulsifier, lignin-cellulose nanocrystals, with their hydrophilic and lipophilic properties, can be firmly adsorbed at the oil-water interface to form an extremely stable solid particle film. This allows for the construction of a stable two-way texture without relying on traditional synthetic surfactants, helping to reduce the risk of formulation irritation. Detailed Implementation

[0039] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0040] Caprylic / capric triglyceride CAS: 65381-09-1, Ceramide CAS: 100403-19-8, Molecular sieve (4A) CAS: 63231-69-6, Lignin CAS: 8068-05-1, Stearic acid CAS: 57-11-4, 4-Dimethylaminopyridine CAS: 1122-58-3, N,N'-Dicyclohexylcarbodiimide CAS: 538-75-0, (3-glycidoxypropyl)trimethoxysilane CAS: 2530-83-8, β-glucan CAS: 9012-72-0, Dipotassium glycyrrhizate CAS: 68797-35-3, purchased from Shanghai Yuanye Biotechnology Co., Ltd.

[0041] Hydrogenated polyisobutylene CAS: 68937-10-0, purchased from Hubei Jusheng Technology Co., Ltd.

[0042] Vinyl lauryl ester, CAS: 2146-71-6, purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.

[0043] The immobilized enzyme was purchased from Henan Shengxing Biotechnology Co., Ltd.

[0044] Centella asiatica extract CAS: 84696-21-9, purchased from Wuhan Pushida Biotechnology Co., Ltd.

[0045] The main components of Centella asiatica extract include asiaticoside, hydroxyasiaticoside, asiatic acid, hydroxyasiatic acid, ursolic acid, β-sitosterol, etc.

[0046] Sorbitan oleate CAS: 223706-40-9, purchased from Jinjinle Chemical Co., Ltd.

[0047] The lignin was vacuum dried overnight at 60°C to completely remove moisture, resulting in dried lignin.

[0048] The lignin-cellulose nanocrystal dispersion is obtained by dispersing lignin-cellulose nanocrystals in deionized water at a mass ratio of 1:100 and pre-dispersing them at 10,000 rpm for 5 minutes using a high-speed homogenizer.

[0049] Example 1: A process for preparing a soothing two-way emulsion facial mask, comprising the following steps:

[0050] S1.1 Weigh the following raw materials: 3 parts by weight of caprylic / capric triglyceride, 1 part by weight of hydrogenated polyisobutylene, 15 parts by weight of glycerol, 0.1 part by weight of carbomer, 1 part by weight of esterified ceramide precursor, 5 parts by weight of lignin-cellulose nanocrystals, 3 parts by weight of Centella asiatica extract, 0.5 parts by weight of β-glucan, 0.1 parts by weight of dipotassium glycyrrhizate, and 0.5 parts by weight of sorbitan oleate.

[0051] S1.2 Add caprylic / capric triglyceride, hydrogenated polyisobutylene and sorbitan olive oil ester to the oil phase pot, heat to 70°C, and stir at 300 rpm until completely dissolved to obtain the oil phase;

[0052] Add deionized water, glycerol and carbomer to an aqueous phase pot, heat to 75°C, and stir at 400 rpm for 20 min until the carbomer is completely swollen to obtain the aqueous phase.

[0053] The oil phase was added to the aqueous phase through a filter screen, and the temperature was maintained at 75°C. The mixture was homogenized at 5000 rpm for 5 minutes using a high-speed homogenizer to obtain the primary emulsion.

[0054] S1.3. Add the lignin-cellulose nanocrystal dispersion to the primary emulsion, stir at 200 rpm, and begin cooling. When the temperature drops to 60°C, add the esterified ceramide precursor and continue stirring and cooling. When the temperature drops to 45°C, neutralize the carbomer with 0.01 mol / L arginine solution to pH 6.5. When the temperature drops to 35°C, add Centella asiatica extract, β-glucan, and dipotassium glycyrrhizate, and stir at 200 rpm for 15 min to obtain the paste.

[0055] S1.4. The prepared cream is degassed in a vacuum degassing machine with a vacuum degree of -0.09MPa for 15 minutes, and after filling, it is aged at room temperature for 24 hours to obtain a soothing two-way emulsion mask.

[0056] The preparation method of lignin-cellulose nanocrystals is as follows:

[0057] Dry lignin was dispersed in anhydrous toluene at a mass ratio of 1:15 and stirred at 300 rpm. Stearic acid (10% of the mass of lignin) and 4-dimethylaminopyridine (5% of the mass of lignin) were added sequentially to obtain a mixture.

[0058] Under nitrogen protection and cooling in an ice-water bath at 4°C, N,N'-dicyclohexylcarbodiimide, accounting for 75% of the lignin mass, was added dropwise to the mixture. After the addition was complete, the ice bath was removed, the reaction system was heated to 60°C, and the reaction was stirred continuously for 24 hours.

[0059] After the reaction is complete, the reaction solution is cooled to room temperature, filtered, and evaporated to concentrate to 1 / 3 of the original volume to obtain a concentrated solution.

[0060] The concentrate was added dropwise to 10 times its volume of n-hexane to precipitate lignin; the precipitate was collected by centrifugation at 8000 rpm, washed three times with n-hexane, and freeze-dried to obtain partially hydrophobic lignin.

[0061] A portion of hydrophobic lignin powder was dispersed in isopropyl octanoate at a mass ratio of 1:20. The mixture was then ultrasonically destroyed for 3 minutes at 200W in a 40°C water bath to form a hydrophobic lignin-oil solution.

[0062] A hydrophobic lignin-oil solution was added to a 0.5 wt% cellulose nanocrystal dispersion, homogenized at 10,000 rpm for 5 min using a high-speed homogenizer, and emulsified at room temperature to form an emulsion.

[0063] The emulsion was transferred to a reaction flask, and 5% (3-glycidoxypropyl)trimethoxysilane (by weight of lignin) was added. The mixture was stirred at 200 rpm at 50 °C for 12 h. After the reaction, 3 times the volume of acetone was added to the emulsion to break the emulsion. The solid particles were collected by centrifugation at 10,000 rpm for 30 min.

[0064] The precipitate was washed four times with a 1:1 acetone / ethanol mixture, and then washed once with pure water by centrifugation. Finally, it was freeze-dried at -50℃ for 24 hours to obtain lignin-cellulose nanocrystals.

[0065] The preparation method of esterified ceramide precursor is as follows:

[0066] In a dry reaction flask, ceramide and dry isopropanol were added, and the mixture was heated to 40°C under nitrogen protection and stirred at 200 rpm to obtain a 0.05 mol / L ceramide solution.

[0067] Add 2.5 times the molar equivalent of dried vinyl lauryl ester, 50% of the mass of ceramide, activated molecular sieve, and 20% of the mass of ceramide immobilized enzyme to the ceramide solution in sequence. Seal the solution, maintain the temperature at 40°C, and stir at 200 rpm for 24 h.

[0068] After the reaction is complete, cool the reaction solution to room temperature; first, use a Buchner funnel for coarse filtration, then filter through a neutral alumina column with a particle size of 100 mesh, and collect filtrate A;

[0069] Filtrate A was subjected to vacuum distillation at 40°C to obtain crude product; the crude product was dissolved in anhydrous ethanol at 4°C, crystallized at -20°C for 4 hours and then filtered under vacuum to collect filtrate B.

[0070] The filtrate B was distilled again under reduced pressure and dried at -50°C for 20 hours to obtain the esterified ceramide precursor.

[0071] Example 2: The difference between this example and Example 1 is that the amount of stearic acid added is 15% of the lignin quality.

[0072] Example 3: The difference between this example and Example 1 is that the amount of stearic acid added is 20% of the lignin quality.

[0073] Example 4: The difference between this example and Example 1 is that the amount of (3-glycidoxypropyl)trimethoxysilane added is 7% of the lignin content.

[0074] Example 5: The difference between this example and Example 1 is that the amount of (3-glycidoxypropyl)trimethoxysilane added is 10% of the lignin content.

[0075] Contact angle determination: The lignin-cellulose nanocrystal powder is pressed into a flat and dense sheet on a tablet press under a certain pressure (e.g., 5-10 MPa); using a contact angle measuring instrument, water (polar) and diiodomethane (non-polar) are used as test liquids, and 1-2 μL of liquid is added to the sample surface; the instrument automatically captures the droplet morphology and calculates the static contact angle value through software, and the average value is taken at least 5 times at different positions.

[0076] Weigh a certain mass (e.g., 10.0 mg) of dried lignin-cellulose nanocrystal sample and disperse it in 10.0 mL of deionized water to prepare a dispersion of 1.0 mg / mL. Take 6.0 mL of the above sample dispersion and 2.0 mL of model oil phase (e.g., isopropyl octanoate) into a 20 mL glass bottle. Use a high-speed homogenizer to emulsify under fixed homogenization conditions (12,000 rpm, homogenize for 2 minutes). After emulsification, immediately take 50 μL of emulsion from the bottom of the emulsion (referred to as the sample at t=0 min).

[0077] Emulsification Activity Index (EAI) determination: Take 50 μL of emulsion and quickly add it to 5.0 mL of 1% SDS solution, vortex to mix thoroughly (100-fold dilution); pipette a portion of the diluted solution into a cuvette (1 cm path length) of a UV-Vis spectrophotometer; measure its absorbance (OD0) at a wavelength of 500 nm or 600 nm, using the 1% SDS solution as a reference; calculate EAI = 2 × 2.303 × OD0 × Dilution Factor / c × ϕ × 10 4 Where OD0 is the absorbance value measured at t=0 min; Dilution Factor is the dilution factor (100 here); c is the initial concentration of the sample in the aqueous phase (unit: g / mL, here 1.0 mg / mL = 0.001 g / mL); φ is the oil phase volume fraction (here 2 mL / (6 mL + 2 mL) = 0.25); 10 4 Unit conversion factor.

[0078] Emulsion Stability Index (ESI) determination: The prepared residual emulsion was allowed to stand at room temperature, or, for accelerated testing, centrifuged in a low-speed centrifuge (3000 rpm). At the set time points (t=10, 30, 60, 120 min), 50 μL of emulsion was aspirated again from the same position in the middle of the emulsion. The ESI determination method was exactly the same as described above, but each sample was diluted with 5.0 mL of 1% SDS solution, and its absorbance (OD) value at the same wavelength was measured. t ); Calculate ESI = (OD0 / ΔOD) × Δt; where OD0 is the initial absorbance; ΔOD is the change in absorbance over time Δt (i.e., OD0 - OD). t ); Δt is the measurement time interval (unit: min).

[0079] Table 1 Performance data of lignin-cellulose nanocrystals

[0080]

[0081] Comparing Examples 1, 2, and 3, the contact angle increased from 92° (Example 1) to 118° (Example 3), indicating that the hydrophobicity of the lignin-cellulose nanocrystal surface continued to increase with the increase of stearic acid grafting amount.

[0082] Example 2 has a higher EAI value (105m). 2 / g); This is because moderate hydrophobicity gives lignin ideal amphiphilicity, enabling it to be most effectively adsorbed at the oil-water interface, reducing interfacial tension and forming fine and numerous emulsion droplets.

[0083] Example 1 was not hydrophobic enough, while Example 3 was too hydrophobic and could not be effectively anchored in the aqueous phase, resulting in a decrease in its emulsification efficiency.

[0084] Similarly, the stability of Example 2 was better (155 min); the moderate amphiphilicity allowed the lignin-cellulose nanocrystals to form the most tightly packed and stable solid interface film on the surface of the emulsion droplets; the lignin-cellulose nanocrystals of Example 3 were too hydrophobic, making them prone to aggregation or desorption from the interface, resulting in decreased stability.

[0085] Compared with Examples 1, 4, and 5, the contact angle remained basically unchanged because the cross-linking reaction occurred near the interface and did not significantly change the chemical composition of the particle surface, thus having little impact on hydrophobicity.

[0086] The emulsifying activity (EAI) remained essentially unchanged or decreased slightly; the cross-linking process mainly reinforced the existing structure rather than creating new interfacial activity, so it had little impact on the initial emulsifying ability; the slight decrease may be due to a slight reduction in the number of effective particles caused by minor cross-linking agglomeration.

[0087] Emulsion stability (ESI) increased significantly with increasing crosslinking agent dosage (from 120 min to >240 min); this is because covalent crosslinking firmly locks lignin and CNC in the lignin-cellulose nanocrystal structure, enabling it to resist changes in external conditions such as thermodynamic disturbances and centrifugal force, thus greatly enhancing the long-term stability of the emulsion system.

[0088] Example 6: A process for preparing a soothing two-way emulsion facial mask, comprising the following steps:

[0089] S1.1 Weigh the following raw materials: 8 parts by weight of caprylic / capric triglyceride, 3 parts by weight of hydrogenated polyisobutylene, 20 parts by weight of glycerol, 0.3 parts by weight of carbomer, 5 parts by weight of esterified ceramide precursor, 10 parts by weight of lignin-cellulose nanocrystals, 5 parts by weight of Centella asiatica extract, 1.0 part by weight of β-glucan, 0.3 parts by weight of dipotassium glycyrrhizate, and 1.5 parts by weight of sorbitan oleate.

[0090] S1.2 Add caprylic / capric triglyceride, hydrogenated polyisobutylene and sorbitan olive oil ester to the oil phase pot, heat to 70°C, and stir at 300 rpm until completely dissolved to obtain the oil phase;

[0091] Add deionized water, glycerol and carbomer to an aqueous phase pot, heat to 75°C, and stir at 400 rpm for 20 min until the carbomer is completely swollen to obtain the aqueous phase.

[0092] The oil phase was added to the aqueous phase through a filter screen, and the temperature was maintained at 75°C. The mixture was homogenized at 5000 rpm for 5 minutes using a high-speed homogenizer to obtain the primary emulsion.

[0093] S1.3. Add the lignin-cellulose nanocrystal dispersion to the primary emulsion, stir at 200 rpm, and begin cooling. When the temperature drops to 60°C, add the esterified ceramide precursor and continue stirring and cooling. When the temperature drops to 45°C, neutralize the carbomer with 0.01 mol / L arginine solution to pH 6.5. When the temperature drops to 35°C, add Centella asiatica extract, β-glucan, and dipotassium glycyrrhizate, and stir at 200 rpm for 15 min to obtain the paste.

[0094] S1.4. The prepared cream is degassed in a vacuum degassing machine with a vacuum degree of -0.09MPa for 15 minutes, and after filling, it is aged at room temperature for 24 hours to obtain a soothing two-way emulsion mask.

[0095] The preparation method of lignin-cellulose nanocrystals is as follows:

[0096] Dry lignin was dispersed in anhydrous toluene at a mass ratio of 1:15 and stirred at 300 rpm. Stearic acid (15% by mass of lignin) and 4-dimethylaminopyridine (5% by mass of lignin) were added sequentially to obtain a mixture.

[0097] Under nitrogen protection and cooling in an ice-water bath at 4°C, N,N'-dicyclohexylcarbodiimide, accounting for 100% of the lignin mass, was added dropwise to the mixture. After the addition was complete, the ice bath was removed, the reaction system was heated to 60°C, and the reaction was stirred continuously for 24 hours.

[0098] After the reaction is complete, the reaction solution is cooled to room temperature, filtered, and evaporated to concentrate to 1 / 3 of the original volume to obtain a concentrated solution.

[0099] The concentrate was added dropwise to 10 times its volume of n-hexane to precipitate lignin; the precipitate was collected by centrifugation at 8000 rpm, washed three times with n-hexane, and freeze-dried to obtain partially hydrophobic lignin.

[0100] A portion of hydrophobic lignin powder was dispersed in isopropyl octanoate at a mass ratio of 1:20. The mixture was then ultrasonically destroyed for 3 minutes at 200W in a 40°C water bath to form a hydrophobic lignin-oil solution.

[0101] A hydrophobic lignin-oil solution was added to a 1.0 wt% cellulose nanocrystal dispersion, homogenized at 10,000 rpm for 5 min using a high-speed homogenizer, and emulsified at room temperature to form an emulsion.

[0102] The emulsion was transferred to a reaction flask, and 5% (3-glycidoxypropyl)trimethoxysilane (by weight of lignin) was added. The mixture was stirred at 200 rpm at 50 °C for 12 h. After the reaction, 3 times the volume of acetone was added to the emulsion to break the emulsion. The solid particles were collected by centrifugation at 10,000 rpm for 30 min.

[0103] The precipitate was washed four times with a 1:1 acetone / ethanol mixture, and then washed once with pure water by centrifugation. Finally, it was freeze-dried at -50℃ for 24 hours to obtain lignin-cellulose nanocrystals.

[0104] The preparation method of esterified ceramide precursor is as follows:

[0105] In a dry reaction flask, ceramide and dry isopropanol were added, and the mixture was heated to 50°C under nitrogen protection and stirred at 300 rpm to obtain a 0.1 mol / L ceramide solution.

[0106] Add 2.5 times the molar equivalent of dried vinyl lauryl ester, 80% of the mass of ceramide, activated molecular sieve, and 20% of the mass of ceramide to the ceramide solution in sequence. Seal the solution, maintain the temperature at 40°C, and stir at 200 rpm for 24 h.

[0107] After the reaction is complete, cool the reaction solution to room temperature; first, use a Buchner funnel for coarse filtration, then filter through a neutral alumina column with a particle size of 100 mesh, and collect filtrate A;

[0108] Filtrate A was subjected to vacuum distillation at 40°C to obtain crude product; the crude product was dissolved in anhydrous ethanol at 4°C, crystallized at -20°C for 4 hours and then filtered under vacuum to collect filtrate B.

[0109] The filtrate B was distilled again under reduced pressure and dried at -50°C for 20 hours to obtain the esterified ceramide precursor.

[0110] Example 7: The difference between this example and Example 6 is that the amount of vinyl lauryl ester added is 3.0 times the molar equivalent of ceramide.

[0111] Example 8: The difference between this example and Example 6 is that the amount of vinyl lauryl ester added is 3.5 times the molar equivalent of ceramide.

[0112] Esterification rate determination: Accurately weigh a small amount of product (about 10 mg), dissolve it in an appropriate amount of chromatographic grade acetonitrile / isopropanol solution, vortex and sonicate to completely dissolve it, and set aside; inject ceramide standard and product sample into the high performance liquid chromatograph respectively; calculate the conversion rate by comparing the reduction in the area of ​​the characteristic peak of ceramide before and after the reaction; esterification rate (%) = (1 - area of ​​ceramide peak in product / initial area of ​​ceramide peak) × 100%.

[0113] Determination of critical crystallization temperature: Accurately weigh 5-10 mg of sample and place it in a DSC-specific aluminum crucible, then seal it with a pressure cap; use an empty crucible as a reference; cool the sample from 25 °C to -20 °C at a rate of 5 °C / min and hold for 5 minutes to allow the sample to crystallize fully; heat to 100 °C at a rate of 5 °C / min and record the melting peak; cool again to -20 °C at a rate of 5 °C / min and record the crystallization behavior.

[0114] Table 2 Performance data of esterified ceramide precursors

[0115]

[0116] Comparing Examples 6, 7, and 8, the esterification rate significantly increased with the increase of vinyl lauryl ester content, from 88% (2.5 eq) to 98% (3.5 eq); this is because increasing the concentration of the acyl donor effectively drove the reversible reaction equilibrium to shift towards the forward reaction direction.

[0117] Example 7 (3.0 eq) achieved a high conversion rate of 96%, and the improvement (98%) brought by increasing it to 3.5 eq (Example 8) was not significant, indicating a marginal effect.

[0118] In Example 6, due to the low conversion rate, about 12% of unreacted ceramide remained in the product. These highly crystalline raw materials acted as seed crystals, inducing crystallization throughout the system. Therefore, a relatively high crystallization temperature (15°C) could still be detected.

[0119] Examples 7 and 8, due to their high conversion rates (>96%), produced products with extremely high purity, almost entirely amorphous esterified derivatives. Their molecular structures effectively disrupted the regular hydrogen bond network of ceramides, exhibiting excellent supercooling and low crystallinity.

[0120] Example 9: A process for preparing a soothing two-way emulsion facial mask, comprising the following steps:

[0121] S1.1 Weigh the following raw materials: 5 parts by weight of caprylic / capric triglyceride, 2 parts by weight of hydrogenated polyisobutylene, 17 parts by weight of glycerol, 0.2 parts by weight of carbomer, 1 part by weight of esterified ceramide precursor, 5 parts by weight of lignin-cellulose nanocrystals, 4 parts by weight of Centella asiatica extract, 0.8 parts by weight of β-glucan, 0.2 parts by weight of dipotassium glycyrrhizate, and 1.0 part by weight of sorbitan oleate.

[0122] S1.2 Add caprylic / capric triglyceride, hydrogenated polyisobutylene and sorbitan olive oil ester to the oil phase pot, heat to 70°C, and stir at 300 rpm until completely dissolved to obtain the oil phase;

[0123] Add deionized water, glycerol and carbomer to an aqueous phase pot, heat to 75°C, and stir at 400 rpm for 20 min until the carbomer is completely swollen to obtain the aqueous phase.

[0124] The oil phase was added to the aqueous phase through a filter screen, and the temperature was maintained at 75°C. The mixture was homogenized at 5000 rpm for 5 minutes using a high-speed homogenizer to obtain the primary emulsion.

[0125] S1.3. Add the lignin-cellulose nanocrystal dispersion to the primary emulsion, stir at 200 rpm, and begin cooling. When the temperature drops to 60°C, add the esterified ceramide precursor and continue stirring and cooling. When the temperature drops to 45°C, neutralize the carbomer with 0.01 mol / L arginine solution to pH 6.5. When the temperature drops to 35°C, add Centella asiatica extract, β-glucan, and dipotassium glycyrrhizate, and stir at 200 rpm for 15 min to obtain the paste.

[0126] S1.4. The prepared cream is degassed in a vacuum degassing machine with a vacuum degree of -0.09MPa for 15 minutes, and after filling, it is aged at room temperature for 24 hours to obtain a soothing two-way emulsion mask.

[0127] The preparation method of lignin-cellulose nanocrystals is as follows:

[0128] Dry lignin was dispersed in anhydrous toluene at a mass ratio of 1:15 and stirred at 400 rpm. Stearic acid (15% by mass of lignin) and 4-dimethylaminopyridine (5% by mass of lignin) were added sequentially to obtain a mixture.

[0129] Under nitrogen protection and cooling in an ice-water bath at 4°C, N,N'-dicyclohexylcarbodiimide, accounting for 85% of the lignin mass, was added dropwise to the mixture. After the addition was complete, the ice bath was removed, the reaction system was heated to 60°C, and the reaction was stirred continuously for 24 hours.

[0130] After the reaction is complete, the reaction solution is cooled to room temperature, filtered, and evaporated to concentrate to 1 / 3 of the original volume to obtain a concentrated solution.

[0131] The concentrate was added dropwise to 10 times its volume of n-hexane to precipitate lignin; the precipitate was collected by centrifugation at 8000 rpm, washed three times with n-hexane, and freeze-dried to obtain partially hydrophobic lignin.

[0132] A portion of hydrophobic lignin powder was dispersed in isopropyl octanoate at a mass ratio of 1:20. The mixture was then ultrasonically destroyed for 3 minutes at 200W in a 40°C water bath to form a hydrophobic lignin-oil solution.

[0133] A hydrophobic lignin-oil solution was added to a 0.7 wt% cellulose nanocrystal dispersion, homogenized at 12,000 rpm for 5 min using a high-speed homogenizer, and emulsified at room temperature to form an emulsion.

[0134] The emulsion was transferred to a reaction flask, and 5% (3-glycidoxypropyl)trimethoxysilane (by weight of lignin) was added. The mixture was stirred at 200 rpm at 50 °C for 12 h. After the reaction, 3 times the volume of acetone was added to the emulsion to break the emulsion. The solid particles were collected by centrifugation at 10,000 rpm for 30 min.

[0135] The precipitate was washed four times with a 1:1 acetone / ethanol mixture, and then washed once with pure water by centrifugation. Finally, it was freeze-dried at -50℃ for 24 hours to obtain lignin-cellulose nanocrystals.

[0136] The preparation method of esterified ceramide precursor is as follows:

[0137] In a dry reaction flask, ceramide and dry isopropanol were added, and the mixture was heated to 40°C under nitrogen protection and stirred at 200 rpm to obtain a 0.08 mol / L ceramide solution.

[0138] Add 3.0 times the molar equivalent of dried vinyl lauryl ester, 65% of the mass of ceramide, activated molecular sieve, and 20% of the mass of ceramide to the ceramide solution in sequence. Seal the solution, maintain the temperature at 40°C, and stir at 200 rpm for 24 h.

[0139] After the reaction is complete, cool the reaction solution to room temperature; first, use a Buchner funnel for coarse filtration, then filter through a neutral alumina column with a particle size of 100 mesh, and collect filtrate A;

[0140] Filtrate A was subjected to vacuum distillation at 40°C to obtain crude product; the crude product was dissolved in anhydrous ethanol at 4°C, crystallized at -20°C for 4 hours and then filtered under vacuum to collect filtrate B.

[0141] The filtrate B was distilled again under reduced pressure and dried at -50°C for 20 hours to obtain the esterified ceramide precursor.

[0142] Example 10: The difference between this example and Example 9 is that 3 parts by weight of esterified ceramide precursor are used.

[0143] Example 11: The difference between this example and Example 9 is that 5 parts by weight of esterified ceramide precursor are used.

[0144] Example 12: The difference between this example and Example 9 is that 8 parts by weight of lignin-cellulose nanocrystals are used.

[0145] Example 13: The difference between this example and Example 9 is that 10 parts by weight of lignin-cellulose nanocrystals are used.

[0146] Determination of textural properties (shear thinning and recovery): The sample was kept at 25°C for at least 4 hours using a rheometer with parallel plate clamps; Step 1: A very small shear rate (e.g., 0.1 s⁻¹) was applied. -1The process continues for 60 seconds, during which the viscosity (η1) is measured; this viscosity represents the viscosity of the product when it is stationary in the can; the second step: an instantaneous high shear rate simulating application (e.g., 100s) is applied. -1 (Continue for 30 seconds, and measure the viscosity after a rapid decrease (η2); this viscosity represents the viscosity of the product at the time of application.) Step 3: Immediately restore the shear rate to 0.1s. -1 The viscosity was continuously monitored over time (e.g., 180 seconds) to recover, and the final recovered viscosity (η3) was recorded. The shear thinning index was calculated as η1 / η2, and the recovery rate (%) was calculated as (η3 / η1)×100%.

[0147] Determination of centrifugal stability (precipitation rate): Take about 5g of product and fill it into a centrifuge tube of known weight, and weigh it accurately (W1); place the centrifuge tube in a centrifuge and centrifuge under the set conditions (e.g., 4000rpm, 30 minutes); after centrifugation, carefully observe whether there is oil phase precipitation (upper layer), water phase precipitation (lower layer), or particle precipitation; if there is precipitation, carefully pour out the precipitated liquid and weigh the remaining paste (W2); calculate: precipitation rate (%) = [(W1-W2) / W1] × 100%.

[0148] Determination of moisturizing performance: Prepare several 3cm×3cm medical dialysis membranes or inert synthetic membranes as simulated skin; accurately weigh one membrane (M0); for stable samples, directly take 100mg of the unhomogenized sample and evenly coat it onto the membrane for testing; for samples that have undergone phase separation, take the separated oil phase and water phase separately for testing and record their average (or minimum) value (M1); then the net weight of the sample is M1-M0; place the membrane coated with the sample in a constant temperature and humidity chamber (e.g., temperature 32℃, humidity 40% RH); remove it at the set time point (4h) and weigh it quickly (M t ); Calculate the residual moisture content = (M t -M0) / (M1-M0)×100%.

[0149] Table 3 Performance data of the Soothing Two-Way Body Mask

[0150]

[0151] Comparing Examples 9, 10, and 11, this component mainly acts as a liquid oil-like active ingredient, having little impact on the basic gel network structure of the product; therefore, increasing its dosage hardly changes the product's shear thinning and structural resilience, with the three data remaining essentially the same.

[0152] This component has good compatibility, and its appropriate addition will not damage the stability of the system. In fact, its oil solubility slightly improves the stability, so the precipitation rate has a slight downward trend (from 4.5% to 4.0%).

[0153] When the dosage was increased from 1 part to 5 parts, the residual moisture content after 4 hours increased significantly from 58% to 85%; more esterified ceramide precursors were enzymatically hydrolyzed on the skin surface, continuously releasing ceramides, strengthening the skin barrier, and thus greatly enhancing the skin's water-locking ability.

[0154] Compared with Examples 9, 12, and 13, this component, as a solid particle emulsifier and stabilizer, significantly enhances the three-dimensional network structure of the product when its dosage is increased; therefore, the static viscosity increases significantly, leading to a sharp rise in the shear thinning index.

[0155] Increasing the dosage from 5 parts to 8 parts (Example 12) resulted in a denser network of particles, improving structural resilience (from 92% to 96%). However, excessive addition (10 parts, Example 13) could lead to excessive particle aggregation, which would damage the uniformity and elasticity of the network structure, causing the recovery rate to drop to 88%.

[0156] With increased dosage, more particles are adsorbed at the oil-water interface, forming a more robust interfacial film that effectively prevents droplet aggregation; therefore, the precipitation rate drops sharply (from 4.5% to 0.8%).

[0157] The main function of this ingredient is physical stabilization, not moisturizing; therefore, changes in its dosage have no direct impact on moisturizing performance, and the data remain essentially unchanged.

[0158] Based on the above measurements, Example 11 is selected as the optimal example.

[0159] Comparative Example 1: This comparative example differs from Example 11 in that lignin-cellulose nanocrystals were not added.

[0160] Comparative Example 2: This comparative example differs from Example 11 in that no esterified ceramide precursor was added.

[0161] Table 4 Performance data of the Soothing Two-Way Body Mask

[0162]

[0163] Comparative Example 1 (without lignin-cellulose nanocrystals): the shear thinning index plummeted (from 57 to 12): lacking the robust solid interface film constructed by lignin-cellulose nanocrystals, the system relied only on carbomer gel and a small amount of emulsifier; its structural strength was greatly weakened and its static viscosity was significantly reduced.

[0164] With an extremely low recovery rate (from 90% to 45%), the carbomer gel network recovers slowly and incompletely after being sheared and damaged; while lignin-cellulose nanocrystals can act as nucleation sites, greatly promoting rapid and complete structural recovery.

[0165] The centrifugal stability precipitation rate is >30%. Without the stabilizing mechanism of lignin-cellulose nanocrystals, the emulsion system relying solely on traditional emulsifiers cannot withstand the stress of high-speed centrifugation. The oil phase and water phase separate rapidly, and the product is completely unstable.

[0166] Comparative Example 2, without the addition of esterified ceramide precursor, had texture parameters (shear thinning index and recovery rate) that were comparable to or even slightly better than those of Example 11. This is because the main components maintaining the product structure are carbomer and lignin-cellulose nanocrystals, while the esterified ceramide precursor, as an oil-soluble active ingredient, has little impact on the basic structure.

[0167] The stability remained good, comparable to that of Example 11; this further confirms that the physical stability is mainly determined by the lignin-cellulose nanocrystals and gel network.

[0168] The moisturizing effect is completely lost (from 85% to 38%), and the moisturizing effect plummets to or even below the level of basic moisturizers (such as glycerin); the product's moisturizing and repairing effects come entirely from esterified ceramide precursors.

[0169] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely preferred examples and are not intended to limit the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of the present invention is defined by the appended claims and their equivalents.

Claims

1. A process for preparing a soothing two-way emulsion facial mask, characterized in that, Includes the following steps: S1.1 Weigh the following raw materials in parts by weight: 3-8 parts by weight of caprylic / capric triglyceride, 1-3 parts by weight of hydrogenated polyisobutylene, 15-20 parts by weight of glycerol, 0.1-0.3 parts by weight of carbomer, 1-5 parts by weight of esterified ceramide precursor, 5-10 parts by weight of lignin-cellulose nanocrystals, 3-5 parts by weight of Centella asiatica extract, 0.5-1.0 parts by weight of β-glucan, 0.1-0.3 parts by weight of dipotassium glycyrrhizate, and 0.5-1.5 parts by weight of sorbitan oleate. S1.2 Add caprylic / capric triglyceride, hydrogenated polyisobutylene and sorbitan olive oil ester to the oil phase pot, heat to 70-75℃, and stir at 300-400 rpm until completely dissolved to obtain the oil phase; Add deionized water, glycerol and carbomer to an aqueous phase pot, heat to 75-80℃, and stir at 400-500 rpm for 20 minutes until the carbomer is completely swollen to obtain the aqueous phase. The oil phase is added to the aqueous phase through a filter screen, the temperature is maintained at 75℃, and the mixture is homogenized for 3-5 minutes at 5000-8000 rpm using a high-speed homogenizer to obtain the primary emulsion. S1.3 Add the lignin-cellulose nanocrystal dispersion to the primary emulsion, stir at 200-400 rpm, and begin cooling. When the temperature drops to 60℃, add the esterified ceramide precursor and continue stirring and cooling. When the temperature drops to 40-45℃, neutralize the carbomer with 0.01 mol / L arginine solution to a pH of 6.0-7.

0. When the temperature drops to 35-38℃, add Centella asiatica extract, β-glucan, and dipotassium glycyrrhizate, and stir at 200 rpm for 10-15 min to obtain the paste. In S1.3, the lignin-cellulose nanocrystal dispersion is obtained by dispersing lignin-cellulose nanocrystals in deionized water at a mass ratio of 1:100 and pre-dispersing them in a high-speed homogenizer at a speed of 10,000 rpm for 3-5 minutes. S1.4 Remove air bubbles from the prepared cream in a vacuum degassing machine, fill it, and then age it at room temperature for 24 hours to obtain a soothing two-way emulsion mask. The preparation method of the lignin-cellulose nanocrystals is as follows: Dry lignin was dispersed in anhydrous toluene at a mass ratio of 1:15 and stirred at 300-400 rpm. Stearic acid and 4-dimethylaminopyridine were added sequentially to obtain a mixture. The amount of stearic acid added was 10-20% of the lignin mass, and the amount of 4-dimethylaminopyridine added was 5% of the lignin mass. Under nitrogen protection and cooling in an ice-water bath at 0-5°C, N,N'-dicyclohexylcarbodiimide was added dropwise to the mixture; the amount of N,N'-dicyclohexylcarbodiimide added was 75-100% of the lignin content; after the addition was complete, the ice bath was removed, the reaction system was heated to 50-60°C, and the reaction was stirred continuously for 24-48 hours. After the reaction is complete, the reaction solution is cooled to room temperature, filtered, and evaporated to concentrate to 1 / 3 of the original volume to obtain a concentrated solution. The concentrate was added dropwise to 10 times its volume of n-hexane to precipitate lignin; the precipitate was collected by centrifugation at 8000 rpm, washed 2-3 times with n-hexane, and freeze-dried to obtain partially hydrophobic lignin. A portion of the hydrophobic lignin powder was dispersed in isopropyl octanoate at a mass ratio of 1:

20. The mixture was then ultrasonically destroyed for 2-3 minutes at 200W in a 40°C water bath to form a hydrophobic lignin-oil solution. A hydrophobic lignin-oil solution was added to a 0.5-1.0 wt% cellulose nanocrystal dispersion, homogenized at 10,000-15,000 rpm for 3-5 min using a high-speed homogenizer, and emulsified at room temperature to form an emulsion. The emulsion was transferred to a reaction flask, and (3-glycidoxypropyl)trimethoxysilane was added. The mixture was stirred at 200 rpm at 50-60°C for 6-12 hours. The amount of (3-glycidoxypropyl)trimethoxysilane added was 5-10% of the lignin content. After the reaction, acetone was added to the emulsion to break the emulsion, and the solid particles were collected by high-speed centrifugation at 10000-15000 rpm for 20-30 minutes. The precipitate was washed repeatedly 3-4 times with a 1:1 acetone / ethanol mixed solvent, and finally washed once with pure water by centrifugation. Then it was freeze-dried at -50℃ for 24h to obtain lignin-cellulose nanocrystals. The preparation method of the esterified ceramide precursor is as follows: In a dry reaction flask, add ceramide and dry isopropanol, heat to 40-50℃ under nitrogen protection, and stir at 200-300 rpm to obtain a ceramide solution of 0.05-0.1 mol / L. Dry vinyl lauryl ester, activated molecular sieve, and immobilized enzyme were added sequentially to the ceramide solution. The solution was sealed and the temperature was maintained at 40-50℃. The mixture was stirred at 100-200 rpm for 24-48 hours. The amount of vinyl lauryl ester added was 2.5-3.5 times the molar equivalent of ceramide. The amount of immobilized enzyme added was 20-25% of the mass of ceramide. The amount of activated molecular sieve added was 50-80% of the mass of ceramide, and the molecular sieve needed to be activated at 200℃ for 4 hours before use. After the reaction is complete, cool the reaction solution to room temperature; first, use a Buchner funnel for coarse filtration, and then filter it through a neutral alumina column with a particle size of 100-200 mesh, and collect filtrate A; Filtrate A was subjected to vacuum distillation at 40°C to obtain crude product; the crude product was dissolved in anhydrous ethanol at 4°C, crystallized at -20°C for 4 hours and then filtered under vacuum to collect filtrate B. The filtrate B was distilled again under reduced pressure and dried at -40 to -60°C for 18-24 hours to obtain the esterified ceramide precursor.

2. The preparation process of the soothing two-way emulsion mask according to claim 1, characterized in that, In step S1.4, the vacuum degree of the degassing machine is -0.09 to -0.10 MPa, and the degassing time is 10-15 min.

Images