Preparation method of hydrogenated castor seed oil and hair care essence thereof

Abstract

The application belongs to the field of daily chemicals, and particularly relates to a preparation method of hydrogenated castor seed oil and hair-care essence containing the hydrogenated castor seed oil. The preparation method of the hydrogenated castor seed oil comprises the following steps: S1. crushing castor seeds and sieving to obtain castor seed powder; S2. treating the castor seed powder in a low-frequency pulse electric field and intermittent microwave to obtain pretreated castor seed powder; S3. mixing the pretreated castor seed powder with a composite enzyme preparation and performing subcritical extraction to obtain an extraction liquid; S4. filtering and distilling the extraction liquid to obtain a refined filtrate; S5. mixing the refined filtrate with a palladium-carbon catalyst to obtain a semi-finished product; and S6. passing the semi-finished product through a fixed bed layer of special activated carbon to obtain a first filtrate, and filtering the first filtrate to obtain the hydrogenated castor seed oil. The hydrogenated castor seed oil used in the application can achieve the effects of high active ingredient retention rate and good oxidation stability, and can lay a foundation for the efficacy and safety of the hair-care essence prepared subsequently.

Description

Technical Field

[0001] This invention belongs to the field of daily chemical products, specifically relating to a method for preparing hydrogenated castor seed oil and its hair care essence. Background Technology

[0002] Hair serum is a core product for deep repair of damaged hair. Its mechanism of action is that cationic conditioning agents are directionally adsorbed onto negatively charged damaged hair strands, while film-forming ingredients such as oils and silicone oils are deposited on the hair surface to fill the gaps between hair cuticles, reduce friction, and restore the smoothness and shine of the hair. It is a research focus in the cosmetics field.

[0003] Currently available high-end hair serums generally rely heavily on silicone oils and synthetic cationic surfactants in their conditioning systems. Silicone oils are primarily composed of high-viscosity polydimethylsiloxane and its derivatives, such as amino-terminated polydimethylsiloxane. While these ingredients provide excellent instant smoothness and dry / wet combability, significantly enhancing the user experience, their strong hydrophobicity and bioinertness lead to the formation of a difficult-to-wash buildup on the hair surface with prolonged use. This causes the hair to gradually lose its volume and become flat and greasy. Furthermore, the non-biodegradable nature of silicone oils makes them easily discharged into the environment after use, posing a potential environmental residue risk. Traditional synthetic cationic surfactants, such as behenyltrimethylammonium chloride, are mainly effective in neutralizing static electricity on the hair surface and reducing frizz. However, the repairing effect of these ingredients is mostly limited to the surface layer of the hair. They lack effective repair capabilities for deep damage caused by factors such as frequent perming and dyeing, ultraviolet radiation, and environmental irritants, such as loss of lipids and breakage of keratin structure within the hair. Therefore, they are difficult to fundamentally improve the health of the hair.

[0004] Castor seed oil, rich in ricinoleic acid, possesses excellent hair affinity and film-forming potential, making it a highly valuable active ingredient for hair care. However, directly applying natural castor seed oil to hair serums still faces several challenges. First, castor seed oil has extremely high viscosity and is difficult to emulsify, making it difficult to achieve stable compatibility with the cationic system in hair serums, easily leading to instability issues such as greasiness and layering. Second, the high content of unsaturated bonds in the molecular structure of natural castor seed oil makes it chemically unstable, prone to oxidative rancidity during storage and use, shortening the product's shelf life and potentially causing scalp irritation. Finally, the relatively large molecular size of natural castor seed oil limits its penetration ability, making it unable to effectively penetrate the hair cuticle and exert deep repair effects on the hair shaft. Summary of the Invention

[0005] The technical problem to be solved by this invention is to provide a method for preparing hydrogenated castor seed oil and its hair care essence. This invention obtains hydrogenated castor seed oil through a green catalytic hydrogenation process, which can achieve the effects of no heavy metal residue, high retention rate of active ingredients and good oxidation stability, thus laying a solid foundation for the efficacy and safety of the hair care essence subsequently prepared.

[0006] The technical solution adopted by the present invention to solve the above problems is as follows: A method for preparing hydrogenated castor seed oil includes the following steps: S1. Dehull and wash the castor seeds, dry them at 45-50℃ until the moisture content is less than 5%, then grind them and pass them through a 50-200 mesh sieve to obtain castor seed powder; S2. Adjust the field strength of the low-frequency pulsed electric field to 3-5 kV / cm, the frequency to 20-50 kHz, the pulse width to 8-15 μs, and the duration to 30-60 s; adjust the power of the intermittent microwave to 300-500 W, the frequency to 2000-3000 MHz, and the duration to 30-60 s; treat the castor seed powder first in the low-frequency pulsed electric field, and then in the intermittent microwave, alternating the treatment several times to obtain pretreated castor seed powder; S3. Mix the pretreated castor seed powder with a compound enzyme preparation, which includes cellulase, pectinase, and hemicellulase. The amount of the compound enzyme preparation added is 4-6% of the mass of the pretreated castor seed powder. After mixing, add the extraction solvent and an entrainer of 3-5% of the volume of the extraction solvent. Perform subcritical extraction at a temperature of 35-40℃ for 1.5-2 hours. First, adjust the extraction pressure to 0.8-1.2 MPa and maintain it for 5-8 minutes. Then, within 2-3 minutes, increase the extraction pressure to 1.2-1.5 MPa at a constant rate and maintain it for 3-5 minutes. Finally, within 2-3 minutes, decrease the extraction pressure to 0.5 MPa at a constant rate and maintain it for 8-10 minutes. Repeat the above extraction process three times. During the extraction, stir at a low speed of 60 r / min and adjust the flow rate of the extraction solvent to 1.0-1.5 L / min. Collect the extract. S4. The extract is vacuum filtered through a 5–20 μm microporous membrane at a vacuum level of -0.06 to -0.09 MPa to obtain crude oil. The crude oil is then subjected to primary molecular distillation at a temperature of 80–85 °C and a pressure of 0.1–0.5 mbar to obtain the primary distillate. The primary distillate is then subjected to secondary molecular distillation at a temperature of 120–125 °C and a pressure of 0.01–0.05 mbar to obtain the secondary distillate. The secondary distillate is then subjected to tertiary molecular distillation at a temperature of 160–165 °C and a pressure of 0.001–0.005 mbar to obtain the tertiary distillate. The tertiary distillate is then filtered through a 0.1–0.2 μm microporous membrane to obtain the fine filtrate. S5. Transfer the filtrate to a reactor in a hydrogen atmosphere, and then mix it with a palladium-on-carbon catalyst. The amount of palladium-on-carbon catalyst added is 0.5-1% of the mass of the filtrate. Continuously introduce hydrogen gas and maintain the hydrogen pressure at 2-3 MPa. React at a temperature of 80-100℃ for 3-4 hours, and control the iodine value to 80-85 gI2 / 100g to obtain a semi-finished product. S6. After cooling the semi-finished product to room temperature, it is passed through a fixed bed of activated carbon containing palladium on carbon catalyst. The flow rate of the semi-finished product is adjusted to 1.0-2.0 BV / h, the height-to-diameter ratio of the activated carbon bed is 3-5:1, and the mesh size of the activated carbon is 20-40 mesh to obtain a primary filtrate. The primary filtrate is then pressure filtered using a 0.2-0.5 μm filter element at a pressure of 0.1-0.3 MPa. The filtrate is collected to obtain hydrogenated castor seed oil.

[0007] Further, in step S3, the mass ratio of cellulase, pectinase, and hemicellulase is 3:1:2.

[0008] Further, in step S3, the extraction solvent is dimethyl ether, and the entrainer is anhydrous ethanol.

[0009] Furthermore, in step S6, the filter element is a polytetrafluoroethylene filter element.

[0010] Through the above technical solution, firstly, the alternating synergistic treatment of pulsed electric field and intermittent microwave achieves efficient cell wall disruption of castor seeds, creating favorable conditions for subsequent extraction; secondly, the established compound enzyme-assisted subcritical fluid extraction system achieves efficient and selective extraction of target components under low-temperature conditions. The combination of pulsed-microwave pretreatment and compound enzyme-assisted subcritical extraction achieves efficient cell wall disruption and extraction under low-temperature conditions (<50℃), maximizing the retention of natural active ingredients. Compared with traditional high-temperature and high-pressure processes (>150℃), this invention effectively retains the natural active ingredients in castor seed oil, such as heat-sensitive components like tocopherols and phytosterols. The multi-stage molecular distillation-membrane separation coupled purification process used in the preparation process enables precise separation of fatty acid components and efficient removal of impurities, improving the purity of effective substances. The use of a noble metal catalyst to complete the hydrogenation reaction under mild conditions avoids heavy metal residues and the formation of trans fatty acids. The preparation process uses green solvents such as subcritical dimethyl ether to replace traditional organic solvents such as n-hexane, achieving solvent-free residues and meeting the requirements of green chemistry and sustainable development.

[0011] This invention provides a hair care essence containing hydrogenated castor seed oil prepared by the above-mentioned method, comprising the following components calculated by weight percentage: 3.0-8.0% hydrogenated castor seed oil prepared by this invention; 1.0-3.0% cationic conditioner; 2.0-10.0% silicone oil conditioner; 4.0-8.0% fatty alcohol emulsifier; 1.0-4.0% moisturizer; 0.05-5% pH adjuster; 0.5-1.0% preservative; 0.1-0.5% fragrance; and the balance being deionized water.

[0012] Furthermore, the cationic conditioner includes at least one of behenamidopropyl dimethylamine and behenyltrimethylammonium chloride.

[0013] Through the above technical solutions, both behenamidopropyl dimethylamine and behenyltrimethylammonium chloride are long-chain alkyl quaternary ammonium salts or amines, exhibiting excellent hair affinity. Specifically, behenyltrimethylammonium chloride effectively neutralizes the negative charge on the hair surface, significantly reducing static electricity and frizz; while behenamidopropyl dimethylamine, after protonation under acidic conditions (such as the pH of the hair care essence in this application at 5.0-6.0), also possesses good adsorption properties and provides a gentler conditioning feel. The combined use of these two ingredients forms a uniform adsorption layer on the hair surface, providing not only immediate smoothness when combing wet hair, but also forming a synergistic composite film with subsequently added hydrogenated castor oil, silicone oil, and other ingredients. This ensures the conditioning effect while avoiding the accumulation problems that may arise from using a single cationic surfactant.

[0014] Furthermore, the silicone oil conditioning agent includes at least one of bis-aminopropyl polydimethylsiloxane, ammonia-terminated polydimethylsiloxane, and polydimethylsiloxane with a viscosity of 1 to 50 cSt.

[0015] Through the above technical solutions, a multi-layered conditioning system is constructed by compounding silicone oils with different structures and viscosities. Bis-aminopropyl polydimethylsiloxane and amino-terminated polydimethylsiloxane, due to the positive charge on their side chains' amino groups, can be directionally adsorbed onto the negatively charged sites of damaged hair strands, providing long-lasting repair and moisturizing effects and enhancing hair resilience. The deliberately selected polydimethylsiloxane (low-viscosity silicone oil) with a viscosity of 1-50 cSt balances the product's feel and texture. Low-viscosity silicone oil has good spreadability and volatility, quickly forming a uniform film on the hair surface during application and rinsing, resulting in a light, non-greasy smoothness and effectively avoiding the accumulation and flattening problems caused by long-term use of high-viscosity silicone oil. The combination of these three silicone oils with hydrogenated castor oil forms a moisturizing yet breathable protective film on the hair surface, achieving a balance between smoothness and volume.

[0016] Furthermore, the fatty alcohol emulsifier includes at least one of cetyl alcohol, stearyl alcohol, and cetearyl alcohol.

[0017] Through the above technical solution, the fatty alcohol emulsifiers (cetyl alcohol, stearyl alcohol, cetearyl alcohol) selected in this invention have a dual function of "emulsification stabilization" and "paste construction" in the system. First, as nonionic emulsifiers, they can synergistically work with the main emulsifier (such as cationic surfactants) to form a tight mixed film at the oil-water interface, significantly reducing interfacial tension. This allows for the uniform and stable emulsification and dispersion of oily components such as hydrogenated castor oil and silicone oil in water, preventing instability such as layering and oil separation during product storage. Second, these high-carbon-chain fatty alcohols can insert into layered liquid crystal or micelle structures, increasing the system's order and cohesion, effectively improving the consistency and texture of the hair serum, and giving the product ideal rheological properties that make it easy to apply without being too thin. At the same time, fatty alcohols themselves can also deposit on the hair surface, assisting in the film formation of oils and conditioning agents, providing additional smoothness and moisturization without causing a sticky feeling like synthetic polymers.

[0018] Furthermore, the moisturizer includes at least one of sorbitol, glycerin, and propylene glycol.

[0019] Through the above technical solutions, polyol-based moisturizers possess excellent hygroscopic and moisturizing properties. They can penetrate into the gaps between the hair cuticles, capture moisture, help maintain the internal moisture balance of the hair strands, and prevent the hair from becoming brittle and frizzy due to dryness. Simultaneously, these moisturizers can also improve the texture of the product to a certain extent, making it more moisturizing and easier to spread during application, enhancing the comfort of use, and creating a favorable medium environment for the even deposition of subsequent oils and conditioning agents.

[0020] Furthermore, the pH adjuster includes at least one of lactic acid and citric acid.

[0021] Furthermore, the preservative includes at least one of phenoxyethanol, benzyl alcohol, sodium benzoate, and their salts.

[0022] Furthermore, the fragrance agent is a flavoring.

[0023] The present invention has the following beneficial effects: 1. This invention employs a green catalytic hydrogenation process to obtain hydrogenated castor seed oil, achieving the effects of no heavy metal residue, high retention rate of active ingredients, and good oxidative stability, thus laying a solid foundation for the efficacy and safety of the subsequently prepared hair care essence.

[0024] 2. The hydrogenated castor seed oil prepared in this invention partially replaces traditional high-viscosity silicone oil. The hydrogenated castor seed oil prepared in this invention has a lipid structure similar to hair keratin, which allows it to effectively penetrate into the hair shaft and replenish lost lipids. This makes the hair shaft stronger from the inside out, fundamentally reducing hair breakage and split ends caused by combing, and improving the problem of silicone oil accumulation.

[0025] 3. This invention, through precise emulsification process and component matching, enables high-content natural oils to be compatible with cationic and silicone oil systems, preventing oil separation and stratification of the hair essence when stored at room temperature, thus improving the storage stability of the hair essence. Furthermore, the resulting hair essence is easy to apply, and after rinsing, the hair is fluffy, light, naturally shiny, and without any greasy or heavy feeling. Detailed Implementation

[0026] To make the technical problems, solutions, and advantages of this invention clearer, a detailed description will be provided below with reference to specific examples. However, the scope of protection of this invention is not limited to the following specific embodiments. The described embodiments are merely some, not all, of the embodiments of this invention, and are not intended to limit the invention. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0027] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0028] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0029] In the quantitative experiments in the following examples, three replicate experiments were set up, and the data are the average of the three replicate experiments or the average ± standard deviation.

[0030] The present invention includes Examples 1 to 3 and Comparative Examples 1 to 3, and the specific components and contents are shown in Table 1, in units of weight percentage.

[0031] Table 1

[0032] Specifically, the method for preparing hydrogenated castor seed oil according to the present invention in the above embodiments and comparative examples includes the following steps: S1. Dehull and wash the castor seeds, dry them at 45-50℃ until the moisture content is less than 5%, then grind them and pass them through a 100-mesh sieve to obtain castor seed powder; S2. Adjust the field strength of the low-frequency pulsed electric field to 4kV / cm, the frequency to 30kHz, the pulse width to 10μs, and the duration to 30s; adjust the power of the intermittent microwave to 400W, the frequency to 2450MHz, and the duration to 30s; treat the castor seed powder first in the low-frequency pulsed electric field, and then in the intermittent microwave, alternating the treatment three times to obtain pretreated castor seed powder; S3. Mix the pretreated castor seed powder with a compound enzyme preparation, which includes cellulase, pectinase, and hemicellulase, in a mass ratio of 3:1:2. The amount of the compound enzyme preparation added is 5% of the mass of the pretreated castor seed powder. After mixing, add the extraction solvent and an entrainer of 3-5% of the volume of the extraction solvent. Perform subcritical extraction using dimethyl ether as the extraction solvent, at a temperature of 38°C for 2 hours. First, adjust the extraction pressure to 0.8 MPa and maintain it for 5 minutes. Then, within 2 minutes, increase the extraction pressure to 1.2 MPa at a constant rate and maintain it for 3 minutes. Finally, within 2 minutes, decrease the extraction pressure to 0.5 MPa at a constant rate and maintain it for 8 minutes. Repeat the above extraction process three times. During the extraction, stir at a low speed of 60 r / min and adjust the flow rate of the extraction solvent to 1.0 L / min. Collect the extract. S4. The extract was vacuum filtered through a 15 μm microporous membrane at a vacuum level of -0.08 MPa to obtain crude oil. The crude oil was then subjected to first-stage molecular distillation at 82 °C and 0.3 mbar to obtain the first-stage distillate. The first-stage distillate was then subjected to second-stage molecular distillation at 123 °C and 0.03 mbar to obtain the second-stage distillate. The second-stage distillate was then subjected to third-stage molecular distillation at 162 °C and 0.003 mbar to obtain the third-stage distillate. The third-stage distillate was filtered through a 0.1 μm ceramic membrane to obtain the fine filtrate. S5. Transfer the filtrate to a reactor in a hydrogen atmosphere, and then mix it with a palladium-on-carbon catalyst. The amount of palladium-on-carbon catalyst added is 0.8% of the mass of the filtrate. Continuously introduce hydrogen gas and maintain the hydrogen pressure at 2.5 MPa. React at 90℃ for 3.5 h and control the iodine value to 80 g I2 / 100 g to obtain a semi-finished product. S6. After cooling the semi-finished product to room temperature, it is passed through a fixed bed of activated carbon containing palladium on carbon catalyst. The flow rate of the semi-finished product is adjusted to 1.5 BV / h, the height-to-diameter ratio of the activated carbon bed is 3:1, and the mesh size of the activated carbon is 40 mesh. The first-stage filtrate is obtained. The first-stage filtrate is then pressure filtered through a 0.2 μm polytetrafluoroethylene filter element at a pressure of 0.3 MPa. The filtrate is collected to obtain hydrogenated castor seed oil.

[0033] The conventional hydrogenated castor oil in the comparative example is a commercially available product. The preparation method of commercially available hydrogenated castor oil includes the following steps: D1. After removing impurities and washing the castor seeds, dry them at 108℃ until the moisture content is less than 8%, then crush and roll them into blanks with a thickness of about 0.4mm. D2. The raw material is fed into a screw press for high-temperature pressing, with the pressing temperature controlled at 125℃, to obtain crude oil and cake. D3. The crude oil is subjected to refining processes such as alkali refining and deacidification, bleaching clay decolorization, and steam distillation deodorization to obtain refined castor seed oil; D4. Transfer the refined castor oil to a high-pressure reactor, add a nickel catalyst (0.3% of the oil weight), introduce hydrogen gas, control the reaction temperature at 200℃, the hydrogen pressure at 5MPa, and the reaction time at 5 hours, and control the iodine value to drop to 88gI2 / 100g to obtain the hydrogenated crude product. D5. The crude hydrogenated product is filtered to remove the nickel catalyst, and then decolorized and deodorized to obtain commercially available hydrogenated castor seed oil.

[0034] Specifically, the preparation method of the embodiment includes the following steps: A1. Cetearyl alcohol, behenamidopropyl dimethylamine, and behenyltrimethylammonium chloride are heated together to 75-78°C and melted uniformly to obtain material 1; A2. Heat the deionized water to 75-78°C, then slowly add material 1 to the deionized water and homogenize for 5-8 minutes to obtain material 2; A3. After material 2 cools down to 45-50℃, add hydrogenated castor seed oil, bis-aminopropyl polydimethylsiloxane, polydimethylsiloxane, amino-terminated polydimethylsiloxane, and sorbitol, and stir slowly for 15-20 minutes to obtain material 3. A4. Add preservatives and flavorings, stir well, then add pH adjuster to adjust pH to 5.5, then cool to below 35℃ and discharge to obtain the finished product.

[0035] The preparation method for the comparative example can be obtained in the same way. If there are substances that are not added or replaced, they can be deleted or replaced in the corresponding preparation steps.

[0036] Experimental Test 1. The test used an in vitro hair bundle model for self-comparison before and after, and set up multiple groups for parallel comparison.

[0037] 2. Test environment: temperature 22±2℃, relative humidity 45±5%.

[0038] 3. Testing instruments: Hair combing instrument (XJ810); Precision gloss meter (CQ-60G); Static electricity meter (FMX-003); Facial image analyzer (CK VisioFace 1000D); Electric thermostatic water bath (HWS26); Constant temperature and humidity chamber; Electronic balance (TX3202L); Digital caliper (RK-3).

[0039] 4. Test materials Damaged hair section from Asian individuals (treated with K12 and hydrogen peroxide-ammonia), 28cm long, 5.5-6cm wide, weighing 5.8±0.2g. Dynamic hair bundle, approximately 20cm long, approximately 5.5cm wide, weighing 20-25g. Test combs (tooth spacing 2.0mm and 4.0mm), sodium lauryl sulfate solution (K12), hydrogen peroxide, ammonia, 10g / L citric acid solution, and hair fixing components.

[0040] 5. Testing Methods 5.1 Hair Section / Tie Treatment: Select hair sections / ties from the same batch of Asian hair, soak them in a 5g / L K12 solution, and incubate them in a 40℃ constant temperature water bath for 30 minutes, then rinse them thoroughly with clean water. Next, lay them flat in a mixture of 1% hydrogen peroxide and 2% ammonia, and treat them at 40℃ for 2 hours (turning them over halfway through). Rinse them thoroughly with clean water, neutralize them with 10g / L citric acid for 5 minutes, comb them straight, and air-dry them in a constant temperature and humidity chamber at 22±2℃ and 45±5% relative humidity (>1 hour) and equilibrate (>24 hours). Weigh and select hair ties of the specified weight for later use.

[0041] 5.2 Combing force, friction force, and softness test Using a hair comber, set the displacement to 245mm and the speed to 300mm / min, test the combing force of each section of hair, ensuring that the ends of the hair are completely through the comb. Test each section of hair 3 times.

[0042] Adjust the hair comber displacement to 140mm and the speed to 300mm / min, and test the surface friction and softness of the hair section. Test each hair section 3 times.

[0043] Record the values ​​obtained for each item, and denote them as the baseline value T0 before sample use for each test item.

[0044] Apply the sample to water evenly in a ratio of 1:3 and let it stand for 1 minute. Then rinse with water at 37°C and a flow rate of 4L / min for 1 minute. Repeat the above operation twice, let it dry and balance, and then test the combing force, friction force and softness after use using the same test method. Record the values ​​as T1.

[0045] 5.3 Antistatic Test Select the same batch of real human hair pieces, clean and comb them with K12 solution, and then equilibrate them to constant weight in an environment of 22±2℃ and 45±5%RH (the difference between two consecutive weighings is <0.01g).

[0046] Manually comb through a section of hair 10 times at a speed of 300 mm / s to generate static electricity, and immediately measure the amount of static electricity in the middle of the hair section with a static electricity meter. Repeat 3 times, take the average value as the initial value and record it as T0, and ensure at least 5 valid hair section data.

[0047] Apply the sample to the hair section evenly at a ratio of 1:3 (sample:water) and let it stand for 1 minute. Then rinse with water at 37°C and a flow rate of 4L / min for 1 minute. Repeat the above operation five times. Then comb the hair and balance it to constant weight under the same temperature and humidity environment. Then test the value of the sample using the same measurement method and record it as T1.

[0048] 5.4 Looseness Test To prepare dynamic hair bundles, select Asian hair bundles from the same batch, soak them in a 5 g / L K12 solution, and incubate them in a 40°C water bath for 30 min, then rinse them thoroughly with clean water. Next, lay them flat in a mixture of 1% hydrogen peroxide and 2% ammonia, and treat them at 40°C for 2 h (turning them over halfway through). Rinse them thoroughly with clean water, neutralize them with 10 g / L citric acid for 5 min, comb them straight, and air-dry them in a constant temperature and humidity chamber at 22±2°C and 45±5% relative humidity for >1 h and equilibrate for >24 h. Weigh and select hair bundles of the specified weight for later use.

[0049] After combing the hair strands to make them smooth, place them in a constant temperature and humidity room to air dry naturally for 4 hours. Then comb them again with a dry comb until each strand is distinct, and take a picture of the sample before use using a facial image analyzer.

[0050] The hair strands were divided into a water group and a sample group. For the sample group, the samples from the examples and comparative examples were applied evenly to the hair strands at a dosage of 1.2g, and then the hair strands were gently stroked from top to bottom with both palms for 30 rounds. The water group did not use any samples, but was treated with water, and the operation method was the same as that of the sample group.

[0051] Use a comb to smooth the hair strands and place them in a constant temperature and humidity chamber to air dry naturally for 4 hours. Then comb them again until each strand is distinct, and take a picture of the sample after use using a facial image analyzer.

[0052] Image-Pro Plus software was used to binarize the images of the hair bundle before and after sampling, accurately measuring the projected area (in pixels squared or mm²) occupied by the hair bundle in the image. The size of this projected area is positively correlated with the fluffiness of the hair bundle; that is, the larger the measured projected area, the wider the average distance between hair strands and the more expanded the overall outline of the hair bundle, thus quantitatively characterizing the higher the fluffiness of the hair bundle, and the relevant data were recorded.

[0053] 5.5 hair tensile strength test Select hair sections / strands from the same batch of Asian hair, soak them in a 5g / L K12 solution, and incubate them in a 40℃ constant temperature water bath for 30 minutes, then rinse them thoroughly with clean water. Next, lay them flat in a mixture of 1% hydrogen peroxide and 2% ammonia, and treat them at 40℃ for 2 hours (turning them over halfway through). Rinse them thoroughly with clean water, neutralize them with 10g / L citric acid for 5 minutes, comb them out, and air-dry them in a constant temperature and humidity chamber at 22±2℃ and 45±5% relative humidity (>1 hour) and equilibrate (>24 hours). Weigh and select hair strands of the specified weight for later use.

[0054] Divide a hair bundle into a control area and a sample area. Use a digital caliper to measure the diameter of a single hair strand (the diameter should be between 0.07 and 0.09 mm). Then number the strands to ensure that the hair strand diameters in the control area and the sample area are not significantly different from the tensile strength before the sample was used.

[0055] Perform single-strand tensile force tests according to the order of hair strands, calculate the tensile strength of each hair strand (tensile strength = tensile force / cross-sectional area), and record the initial value T0.

[0056] In the control area, wet the hair strands with 37°C water, apply 1.5mL of water and rub for 1 minute, then rinse with water for 1 minute. Repeat five times.

[0057] The sample was taken by wetting the hair strand with water at 37°C, applying 1.5 mL of the example or comparative sample and rubbing it for 1 minute, then rinsing with water for 1 minute, and repeating five times.

[0058] After the hair bundle is dried and balanced, the diameter of the hair strands and the tensile strength T1 are measured using the same method.

[0059] 6. Statistical Analysis Methods 6.1 The rate of change of each test item before and after the test is K = [(mean of T1 - mean of T0) / mean of T0] * 100% 6.2 Normality test: The difference is tested, and if Sig. > 0.05, it is considered to follow a normal distribution.

[0060] 6.3 Difference Analysis Before-and-after comparison: If the data are normally distributed, use a paired t-test to analyze the difference between T0 and T1; if they are not normally distributed, use a Wilcoxon signed-rank test. P < 0.05 is considered statistically significant.

[0061] Intergroup comparison (fluffiness, hair tensile strength): First, test whether there is a significant difference in baseline T0 between groups (P ≥ 0.05 is considered comparable). Then, conduct intragroup comparisons before and after. Finally, perform intergroup difference analysis on the changes in the two groups (independent samples t-test or Mann-Whitney U test). P < 0.05 is considered to indicate a significant difference in improvement between groups.

[0062] The test results are shown in Table 2.

[0063] Table 2

[0064] The test results of Examples 1-3 show that the hydrogenated castor seed oil prepared by the method of the present invention, when added to hair care essence, can significantly improve the combability, shine, softness, volume and tensile strength of hair, while reducing static electricity and friction. Through the synergistic effect of the hydrogenated castor seed oil, cationic conditioner and silicone oil conditioner of the present invention, the product can have excellent hair care effect.

[0065] A comparison of the test results of Example 2 and Comparative Example 3 shows that, compared with the hydrogenated castor seed oil prepared in this invention without the addition of the hydrogenated castor seed oil, the addition of the hydrogenated castor seed oil prepared in this invention can significantly improve the hair care essence's ability to improve hair combing power, shine, static electricity, friction, softness, volume, and tensile strength.

[0066] By comparing the test results of Example 2 and Comparative Example 1, it can be seen that using hydrogenated castor seed oil prepared in this invention to partially replace traditional high-viscosity silicone oil can reduce hair breakage and split ends caused by combing, while also reducing the possibility of excessive use of silicone oil and improving the problem of silicone oil accumulation.

[0067] A comparison of the test results of Example 2 and Comparative Example 2 shows that the hair care essence prepared with hydrogenated castor seed oil prepared according to the present invention has better hair care ability than that prepared with commercially available ordinary hydrogenated castor seed oil. This indicates that the preparation method of the present invention can improve the efficacy of the product, and also shows that the hydrogenated castor seed oil prepared by the preparation method of the present invention has the effects of high retention rate of active ingredients and good oxidative stability.

[0068] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0069] It should also be noted that the various specific technical features described in the above embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0070] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A method for preparing hydrogenated castor seed oil, characterized in that, Includes the following steps: S1. Dehull and wash the castor seeds, dry them at 45-50℃ until the moisture content is less than 5%, then grind them and pass them through a 50-200 mesh sieve to obtain castor seed powder; S2. Adjust the field strength of the low-frequency pulsed electric field to 3-5 kV / cm, the frequency to 20-50 kHz, the pulse width to 8-15 μs, and the duration to 30-60 s; adjust the power of the intermittent microwave to 300-500 W, the frequency to 2000-3000 MHz, and the duration to 30-60 s; treat the castor seed powder first in the low-frequency pulsed electric field, and then in the intermittent microwave, alternating the treatment several times to obtain pretreated castor seed powder; S3. Mix the pretreated castor seed powder with a compound enzyme preparation, which includes cellulase, pectinase, and hemicellulase. The amount of the compound enzyme preparation added is 4-6% of the mass of the pretreated castor seed powder. After mixing, add the extraction solvent and an entrainer of 3-5% of the volume of the extraction solvent. Perform subcritical extraction at a temperature of 35-40℃ for 1.5-2 hours. First, adjust the extraction pressure to 0.8-1.2 MPa and maintain it for 5-8 minutes. Then, within 2-3 minutes, increase the extraction pressure to 1.2-1.5 MPa at a constant rate and maintain it for 3-5 minutes. Finally, within 2-3 minutes, decrease the extraction pressure to 0.5 MPa at a constant rate and maintain it for 8-10 minutes. Repeat the above extraction process three times. During the extraction, stir at a low speed of 60 r / min and adjust the flow rate of the extraction solvent to 1.0-1.5 L / min. Collect the extract. S4. The extract is vacuum filtered through a 5–20 μm microporous membrane at a vacuum level of -0.06 to -0.09 MPa to obtain crude oil. The crude oil is then subjected to primary molecular distillation at a temperature of 80–85 °C and a pressure of 0.1–0.5 mbar to obtain the primary distillate. The primary distillate is then subjected to secondary molecular distillation at a temperature of 120–125 °C and a pressure of 0.01–0.05 mbar to obtain the secondary distillate. The secondary distillate is then subjected to tertiary molecular distillation at a temperature of 160–165 °C and a pressure of 0.001–0.005 mbar to obtain the tertiary distillate. The tertiary distillate is then filtered through a 0.1–0.2 μm microporous membrane to obtain the fine filtrate. S5. Transfer the filtrate to a reactor in a hydrogen atmosphere, and then mix it with a palladium-on-carbon catalyst. The amount of palladium-on-carbon catalyst added is 0.5-1% of the mass of the filtrate. Continuously introduce hydrogen gas and maintain the hydrogen pressure at 2-3 MPa. React at a temperature of 80-100℃ for 3-4 hours, and control the iodine value to 80-85 gI2 / 100g to obtain a semi-finished product. S6. After cooling the semi-finished product to room temperature, it is passed through a fixed bed of activated carbon containing palladium on carbon catalyst. The flow rate of the semi-finished product is adjusted to 1.0-2.0 BV / h, the height-to-diameter ratio of the activated carbon bed is 3-5:1, and the mesh size of the activated carbon is 20-40 mesh to obtain a primary filtrate. The primary filtrate is then pressure filtered using a 0.2-0.5 μm filter element at a pressure of 0.1-0.3 MPa. The filtrate is collected to obtain hydrogenated castor seed oil.

2. The method for preparing hydrogenated castor seed oil according to claim 1, characterized in that, In step S3, the extraction solvent is dimethyl ether, and the entrainer is anhydrous ethanol.

3. The method for preparing hydrogenated castor seed oil according to claim 1, characterized in that, In step S3, the mass ratio of cellulase, pectinase, and hemicellulase is 3:1:

2.

4. Hydrogenated castor seed oil prepared by the method of any one of claims 1 to 3.

5. A hair care essence containing hydrogenated castor seed oil, characterized in that, It comprises the following components by weight percentage: 3.0–8.0% hydrogenated castor seed oil as described in claim 4; 1.0–3.0% cationic conditioner; 2.0–10.0% silicone oil conditioner; 4.0–8.0% fatty alcohol emulsifier; 1.0–4.0% humectant; 0.05–5% pH adjuster; 0.5–1.0% preservative; 0.1–0.5% fragrance; and the balance being deionized water.

6. The hair care essence containing hydrogenated castor seed oil according to claim 5, characterized in that, The cationic conditioner includes at least one of behenamidopropyl dimethylamine and behentrimethylammonium chloride.

7. The hair care essence containing hydrogenated castor seed oil according to claim 5, characterized in that, The silicone oil conditioning agent includes at least one of bis-aminopropyl polydimethylsiloxane, ammonia-terminated polydimethylsiloxane, and polydimethylsiloxane with a viscosity of 1 to 50 cSt.

8. The hair care essence containing hydrogenated castor seed oil according to claim 5, characterized in that, The fatty alcohol emulsifier includes at least one of cetyl alcohol, stearyl alcohol, and cetearyl alcohol.

9. The hair care essence containing hydrogenated castor seed oil according to claim 5, characterized in that, The moisturizer includes at least one of sorbitol, sorbitol, glycerin, and propylene glycol.

10. The hair care essence containing hydrogenated castor seed oil according to claim 5, characterized in that, The preservative includes at least one of phenoxyethanol, benzyl alcohol, sodium benzoate, and their salts.

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