Body massage oil

Abstract

The invention relates to body massage oil, which relates to the technical field of cosmetics, and is prepared from the following raw materials: glycerol, dipropylene glycol, an inverse emulsion thickener PC305A, xanthan gum, urea, sodium citrate, deionized water and the like. The preparation method comprises the following steps: preparing a xanthan gum hot solution containing sodium citrate and polyhydric alcohol low-temperature suspension slurry of PC305A; adding the low-temperature slurry into a high-temperature hot solution, and inhibiting rapid swelling of a polymer by utilizing ionic strength and temperature difference; continuous stirring is maintained in the cooling process, a dispersed phase is locked through conformation transformation of xanthan gum, and a compact physical interpenetrating network is constructed. According to the invention, the sticky feeling of a high-glycerol system is reduced by compounding the polyhydric alcohols and the urea, and the product is endowed with thick feeling and buffering property close to grease by utilizing a special network structure. The obtained product has the characteristics of lasting lubrication of an oily medium and refreshing and easy washing of an aqueous medium, is excellent in thixotropy, and keeps uniform and stable in long-term storage.

Description

Technical Field

[0001] This application relates to the field of cosmetic technology, and in particular to body massage oils. Background Technology

[0002] Massage media are used to reduce friction between the hands and skin, and to assist in massage techniques. Common massage media mainly include oil-based and water-based media.

[0003] Oil-based massage mediums are typically composed of mineral oil, plant oil, or synthetic grease. Grease has lubricating and film-forming properties, is not easily volatile, and provides long-lasting lubrication. However, oil-based bases feel greasy, have poor penetration, leave a heavy residue on the skin after use, are difficult to wash off, and easily stain clothing. Furthermore, the strong occlusive properties of oils can reduce skin breathability.

[0004] Water-based massage mediums are typically composed of water, water-soluble polymers, and moisturizers, offering a refreshing feel and easy washing. However, due to the rapid evaporation of water, the lubrication of water-based mediums decreases significantly during massage, easily leading to increased resistance and even the formation of mud-like debris due to polymer precipitation, thus affecting the massage experience. Furthermore, conventional water-based gels have relatively simple rheological properties and lack the richness and cushioning properties characteristic of oils.

[0005] To address the insufficient lubrication durability of water-based media, existing technologies often reduce water activity and delay evaporation by increasing the polyol content in the system. However, high glycerin content can lead to a sticky feel and significant drag resistance during later massage phases. Furthermore, controlling the dissolution and swelling of water-soluble polymers in high-concentration polyol systems is challenging. With conventional cold-mixing processes, polymer chains struggle to fully extend, resulting in a weak gel network structure with poor shear resistance, leading to product stratification or thinning. With conventional hot-mixing processes, polymer powders readily form gel clumps upon contact with the solvent due to rapid localized swelling, hindering uniform dispersion and affecting product appearance and feel. Therefore, achieving a similar level of long-lasting lubrication, a substantial feel, and good system stability as oil-based products while maintaining the refreshing and easy-to-wash properties of water-based bases remains a key technical challenge. Summary of the Invention

[0006] The purpose of this application is to provide a body massage oil that solves the problems of existing high-glycerin-content water-based massage media, such as stickiness and poor spreadability. Furthermore, simple water-based gels lack the thickness and cushioning properties unique to oils. In contrast, systems prepared using traditional cold-mixing processes have polymer chains in a disordered and loose state with poor shear recovery, making it difficult to achieve both long-lasting moisturizing and a refreshing and smooth oil-like feel.

[0007] To address the above problems, the present invention provides the following technical solution:

[0008] In a first aspect, the present invention provides a body massage oil, which adopts the following technical solution:

[0009] A body massage oil is made from the following ingredients in the indicated weight percentages: glycerin 24.0%–36.0%; dipropylene glycol 7.0%–16.0%; reverse emulsion thickener PC305A 1.8%–3.2%; xanthan gum 0.25%–0.65%; urea 0.08%–0.60%; sodium citrate 0.04%–0.25%; disodium EDTA 0.01%–0.15%; preservative RP-11 0.20%–0.60%; fragrance 0.05%–0.40%; and the balance being deionized water.

[0010] By employing the above technical solutions, a complex system of high-concentration glycerin and dipropylene glycol is used. While ensuring high osmotic pressure moisturizing capabilities, the structural characteristics of dipropylene glycol interfere with the hydrogen bond network formed between glycerin molecules, thereby reducing the surface tension of the formula and improving stickiness. Simultaneously, urea, as a hydrogen bond modifier, reduces the adhesion between polyols and skin keratin, improving the skin feel after massage. The dual polymer system composed of xanthan gum and the inverse emulsion thickener PC305A, under the specific ionic strength provided by sodium citrate, forms a high-entanglement-density physical gel framework, endowing the product with rheological properties close to oils, namely, the wall-hanging and thickening properties resulting from high zero-shear viscosity, and the excellent spreadability resulting from shear thinning.

[0011] Preferably, the chemical composition of the reverse emulsion thickener PC305A includes polyacrylamide, C13-14 isoparaffins and lauryl ether-7; the chemical composition of the preservative RP-11 includes phenoxyethanol, methylparaben and ethylhexylglycerin.

[0012] By adopting the above technical solution, a reverse emulsion thickener containing C13-14 isoparaffin carrier is selected, a trace amount of oil phase component is introduced, and the flexibility of polyacrylamide segments is combined to further improve the lubricity of the system; the composite preservative system ensures the microbial stability in a high water activity matrix.

[0013] Preferably, the mass ratio of glycerol to dipropylene glycol is (2.3-3.2):1; and the mass ratio of sodium citrate to reverse emulsion thickener PC305A is 1:(15-40).

[0014] By adopting the above technical solutions, controlling the proportion of polyols can balance hygroscopicity and evaporation rate, ensuring the lasting lubrication during massage; controlling the proportion of sodium citrate and thickener aims to establish a suitable ionic strength environment, which is sufficient to inhibit the rapid hydration of polyacrylamide in the high-temperature preparation stage, and also prevents polymer salting out at room temperature, thus maintaining the long-term stability of the system.

[0015] In a second aspect, the present invention provides a method for preparing body massage oil, which adopts the following technical solution:

[0016] A method for preparing a body massage oil includes the following steps:

[0017] S1. Dissolve disodium ethylenediaminetetraacetate, sodium citrate and urea in deionized water, heat to 65-75°C, add xanthan gum under shear conditions, and stir at a constant temperature until a transparent hot solution is formed.

[0018] S2. Mix glycerol and dipropylene glycol, control the temperature at 20-25℃, add reverse emulsion thickener PC305A, and stir to disperse to obtain a low-temperature suspension slurry.

[0019] S3. Keep the temperature of the hot solution obtained in step S1 at 65-75°C, and slowly add the low-temperature suspension slurry obtained in step S2. After the addition is completed, maintain the temperature and stir to mix.

[0020] S4. Turn on the cooling and keep stirring continuously during the cooling process until the temperature drops below 45°C;

[0021] S5. Add fragrance and preservative RP-11, stir evenly, cool and discharge to obtain the body massage oil.

[0022] By employing the above technical solution, the dissolution behavior of polymer chain segments is controlled through temperature difference and ionic strength, thus solving the problems of uneven polymer dispersion and loose structure in conventional processes. The specific physicochemical process is as follows:

[0023] Dispersion and inhibition stages:

[0024] A temperature-differential mixing strategy was employed to introduce a low-temperature inverse emulsion thickener (PC305A) oleyl alcohol slurry into a high-temperature (65–75°C) aqueous phase. Under this high-temperature environment, the sodium citrate electrolyte dissolved in the aqueous phase increased the ionic strength of the solution, compressing the electrical double layer of the polyacrylamide segments in the PC305A inverse emulsion thickener, causing polymer segment contraction and thus reducing its hydration rate. This delayed swelling mechanism ensures that the PC305A inverse emulsion thickener particles can be uniformly dispersed and inserted into the fully expanded xanthan gum solution before the viscosity increases, avoiding gel clumps formed due to rapid localized water absorption.

[0025] Conformational transformation and structural construction stages:

[0026] During the continuous stirring and cooling process, the system undergoes a physical state transition. When the temperature decreases beyond the conformational transition temperature range of xanthan gum (typically around 55°C), the xanthan gum molecular chains transform from a random coil structure at high temperatures to a rigid double helix structure at low temperatures. Simultaneously, as the temperature decreases, the inhibitory effect of high temperatures on the reverse emulsion thickener (PC305A) weakens, and the PC305A chain segments begin to unwind and bind with water molecules.

[0027] At this point, the rigid xanthan gum helical structure forms a physical network framework, effectively encapsulating and confining the flexible polyacrylamide segments that are swelling in situ. This interpenetrating network structure, formed during dynamic cooling, exhibits higher structural density and cohesion compared to the simple physical entanglement formed by direct mixing at room temperature.

[0028] Preferably, in step S1, the shearing conditions are a homogenizer speed of 1500-2500 rpm and a constant temperature stirring time of 20-30 minutes.

[0029] By adopting the above technical solution, high shear and high temperature ensure that the xanthan gum molecular chains are completely unwound and fully hydrated, eliminating incompletely dissolved particles and providing a basis for the subsequent formation of a uniform interpenetrating network.

[0030] Preferably, in step S2, the stirring conditions are a stirring paddle speed of 300-500 rpm and a stirring and dispersion time of 5-10 minutes.

[0031] By adopting the above technical solution, the inverse emulsion thickener (PC305A) can be uniformly suspended in anhydrous polyol medium using low shear force, preventing material splashing or the introduction of too many air bubbles due to excessive stirring.

[0032] Preferably, in step S3, the mixing method is a frame-type scraper mixer with a rotation speed of 40-60 rpm; the feeding time is controlled at 3-5 minutes, and the stirring time after feeding is maintained at 10-15 minutes.

[0033] By adopting the above technical solutions, the frame stirring provides a macroscopic mixing flow field, and with the temperature control strategy, ensures the uniformity of heat exchange in the high viscosity system; controlling the feeding and holding time ensures that the polymer particles are uniformly distributed in the matrix before swelling occurs.

[0034] Preferably, in step S4, the continuous stirring is maintained while the temperature drops through the range of 55°C to 50°C; the cooling process controls the cooling rate to be 1.0 to 2.0°C / min.

[0035] By employing the above technical solution, controlled cooling rate and continuous stirring are crucial for structure formation. In the critical temperature range of 55℃ to 50℃, xanthan gum undergoes a phase transition from a sol state to a gel state. At this time, continuous stirring can prevent excessive local gelation and promote the formation of a uniform microstructure, thereby endowing the finished product with excellent thixotropic properties, that is, it flows smoothly under massage shear and can quickly recover its structural elasticity when at rest.

[0036] In summary, this application includes at least one of the following beneficial technical effects:

[0037] 1. This application utilizes a compound system of glycerin, dipropylene glycol, and urea to improve the skin feel defects of high glycerin content formulations. Dipropylene glycol reduces the surface tension of the system by interfering with the hydrogen bonding between glycerin molecules, and urea reduces the adhesion between polyols and skin proteins, thereby reducing the stickiness during use. At the same time, the composite rheological system constructed by xanthan gum and inverse emulsion thickener endows the aqueous matrix with high zero-shear viscosity and structural support, so that it exhibits a thick feel and cushioning properties close to massage oil without the addition of oil.

[0038] 2. The preparation process of this application improves the structural stability of the product through the synergistic effect of temperature difference control and ionic strength. In the high-temperature mixing stage, sodium citrate inhibits the rapid swelling of the reverse emulsion thickener, ensuring its uniform dispersion in the matrix. In the cooling stage, the physical process of xanthan gum transforming from a sol state to a gel state restricts the polymer chain segments of the dispersed phase, forming a uniform physical interpenetrating network. This endows the product with good thixotropic properties, i.e., it flows smoothly under massage shear, quickly recovers viscosity when stationary, and remains uniform and stable during long-term storage without stratification or water separation.

[0039] 3. The formula of this application provides long-lasting moisturization while maintaining long-lasting lubrication performance. The high concentration of polyol combination has strong hygroscopicity, which can increase the water content of the stratum corneum. The gel network formed by physical cross-linking forms a breathable film on the skin surface, increasing the resistance to water evaporation. This structural characteristic allows the product to maintain a stable rheological state during long-term massage, avoiding dryness and increased friction caused by water evaporation in water-based media, and ensuring the smoothness of the massage process. Detailed Implementation

[0040] Examples 1-3:

[0041] Example 1:

[0042] This embodiment provides a body massage oil, the composition of which is as follows:

[0043] Water (balance, make up to 100%), disodium EDTA-2Na 0.02%, sodium citrate 0.05%, urea 0.10%, xanthan gum 0.30%, glycerin 25.0%, dipropylene glycol (DPG) 8.0%, reverse emulsion thickener (PC305A) 2.0%, fragrance 0.10%, preservative (RP-11) 0.30%.

[0044] The preparation method of this embodiment includes the following steps:

[0045] S1. Add the prescribed amount of deionized water to the main emulsifying pot, start stirring, and then add disodium ethylenediaminetetraacetate (EDTA-2Na), sodium citrate, and urea in sequence, stirring until dissolved. Turn on the heating to raise the temperature of the aqueous phase and control it at 65℃. Adjust the homogenizer speed to 1500 rpm, slowly sprinkle in the xanthan gum powder, and stir for 20 minutes while maintaining a constant temperature until a clear and particle-free hot xanthan gum solution is obtained;

[0046] S2. Add the prescribed amounts of glycerol and dipropylene glycol to the secondary pot, and control the temperature at 25°C (room temperature). Add the reverse emulsion thickener (PC305A) while stirring at a low speed of 300 rpm, and stir for 5 minutes to obtain a uniform white suspension slurry;

[0047] S3. Maintain the main pot temperature at 65℃ and adjust the stirring to a frame-type scraper stirring at 40 rpm. Slowly inject the 25℃ low-temperature second-phase slurry obtained in step S2 into the high-temperature first phase over 3 minutes. After the addition is complete, maintain the temperature at 65℃ and continue stirring for 10 minutes to initially inhibit and disperse the swelling of the reverse emulsion thickener (PC305A) using a low concentration of sodium citrate (0.05%).

[0048] S4. Start the cooling cycle and control the cooling rate at 1.0℃ / min. During the cooling process, keep stirring to allow the system to smoothly pass through the phase transition region of 55℃-50℃. Utilize the xanthan gum conformational recovery process to capture dispersed polymer particles and initially form a gel matrix with an oily feel.

[0049] S5. When the temperature drops to 45℃, add the fragrance and preservative (RP-11) and continue stirring until well mixed. Cool to below 38℃ and filter through a 100-mesh filter to obtain a massage oil with good flowability.

[0050] Example 2:

[0051] This embodiment provides a body massage oil, the composition of which is as follows:

[0052] Water (balance, make up to 100%), disodium EDTA-2Na 0.05%, sodium citrate 0.10%, urea 0.20%, xanthan gum 0.45%, glycerin 32.0%, dipropylene glycol (DPG) 10.0%, reverse emulsion thickener (PC305A) 2.4%, fragrance 0.20%, preservative (RP-11) 0.40%.

[0053] The preparation method of this embodiment includes the following steps:

[0054] S1. Add the prescribed amount of deionized water to the main emulsifying pot, start stirring, and then add disodium ethylenediaminetetraacetate (EDTA-2Na), sodium citrate, and urea in sequence, stirring until dissolved. Turn on the heating to raise the temperature of the aqueous phase and control it at 70℃. Adjust the homogenizer speed to 2000 rpm, slowly sprinkle in the xanthan gum powder, and maintain a constant temperature while stirring for 25 minutes until the xanthan gum is completely hydrated and decycloeded to form a homogeneous hot solution;

[0055] S2. Add the prescribed amounts of glycerol and dipropylene glycol to the auxiliary pot, and control the temperature at 22°C. Add the reverse emulsion thickener (PC305A) while stirring at 400 rpm, and stir for 8 minutes to obtain a uniform suspension slurry. At this point, the reverse emulsion thickener (PC305A) particles did not show significant swelling.

[0056] S3. Maintain the main pot temperature at 70℃ and adjust the stirring to a frame-type scraper stirrer at 50 rpm. Inject the low-temperature second-phase slurry (22℃) obtained in step S2 into the high-temperature first phase within 4 minutes. After the addition is complete, maintain the temperature at 70℃ and continue stirring for 12 minutes. During this stage, the 0.10% sodium citrate concentration provides moderate ionic strength, effectively delaying the explosive hydration of PC305A and ensuring its deep penetration into the gel network.

[0057] S4. Start the cooling cycle and control the cooling rate at 1.5℃ / min. When the system temperature exceeds 55℃ to 50℃, the xanthan gum helical structure rearranges and locks the dispersed and swollen inverse emulsion thickener (PC305A) segments, forming a dense interpenetrating network that combines a gel skeleton with an oily feel;

[0058] S5. When the temperature drops to 42°C, add the premixed fragrance and preservative (RP-11) and stir for 15 minutes until homogeneous. Cool to below 38°C and filter through a 150-mesh filter to obtain a rich-textured massage oil.

[0059] Example 3:

[0060] This embodiment provides a body massage oil, the composition of which is as follows:

[0061] Water (balance, make up to 100%), disodium EDTA-2Na 0.10%, sodium citrate 0.20%, urea 0.50%, xanthan gum 0.60%, glycerin 35.0%, dipropylene glycol (DPG) 15.0%, reverse emulsion thickener (PC305A) 3.0%, fragrance 0.30%, preservative (RP-11) 0.50%.

[0062] The preparation method of this embodiment includes the following steps:

[0063] S1. Add the prescribed amount of deionized water to the main emulsifying pot, start stirring, and then add disodium ethylenediaminetetraacetate (EDTA-2Na), sodium citrate, and urea in sequence, stirring until dissolved. Turn on the heating to raise the temperature of the aqueous phase and control it at 75°C. Adjust the homogenizer speed to 2500 rpm, slowly sprinkle in the xanthan gum powder, and stir for 30 minutes while maintaining a constant temperature. The higher temperature and shear force ensure that the high-concentration xanthan gum is fully extended, and the higher concentration of sodium citrate (0.20%) builds a sufficient ionic barrier for the subsequent addition of high-content PC305A.

[0064] S2. Add the prescribed amounts of glycerol and dipropylene glycol to the secondary pot, and control the temperature at 20°C. Add the reverse emulsion thickener (PC305A) while stirring at 500 rpm, and stir for 10 minutes to obtain a homogeneous suspension slurry with high solids content;

[0065] S3. Maintain the main pot temperature at 75℃ and adjust the stirring to a frame-type scraper stirrer at 60 rpm. Slowly inject the low-temperature second-phase slurry (20℃) obtained in step S2 into the high-temperature first phase. After the addition is complete, maintain the temperature at 75℃ and continue stirring for 15 minutes. The high concentration of salt at high temperature inhibits the swelling rate of the reverse emulsion thickener (PC305A), preventing the formation of localized colloids in the high-viscosity matrix;

[0066] S4. Start the cooling cycle and control the cooling rate at 2.0℃ / min. Quickly pass through the high-temperature zone and complete the rapid locking of the structure near 55℃ to form a gel skeleton with high elastic modulus and high oiliness;

[0067] S5. When the temperature drops to 40℃, add the fragrance and preservative (RP-11) and stir well. When the temperature drops to below 35℃, filter through a 200-mesh filter to obtain a massage oil with an extremely thick texture and an oily feel.

[0068] Comparative Examples 1-5:

[0069] Comparative Example 1

[0070] The difference compared to Example 2 is as follows:

[0071] Different formulation: It does not contain dipropylene glycol (DPG), sodium citrate and urea; the glycerin content is 42.0%, the reverse emulsion thickener (PC305A) is 2.4%, the xanthan gum is 0.45%, and the remainder is water.

[0072] The process differs: it employs the traditional pre-dispersion method. That is, xanthan gum is first dispersed in glycerol at room temperature, then added to water and homogenized, and finally mixed with a reverse emulsion thickener (PC305A).

[0073] Comparative Example 2:

[0074] The difference compared to Example 2 is as follows:

[0075] The process is different: a one-step cold mixing method is used. All raw materials of phase A (water, salt, urea) and phase B (glycerol, DPG, PC305A) are directly mixed and stirred evenly at room temperature (25°C), without the involvement of heating, phase separation preparation and temperature difference mixing steps.

[0076] Comparative Example 3:

[0077] The difference compared to Example 2 is as follows:

[0078] The formulation is different: it does not contain dipropylene glycol (DPG) and urea; the glycerol content is adjusted to 42.0% (keeping the total polyol content consistent), and the remaining components are the same as in Example 2.

[0079] The process is the same: the same thermally induced rheological hysteresis process as in Example 2 is used.

[0080] Comparative Example 4:

[0081] The difference compared to Example 2 is as follows:

[0082] Different formula: No sodium citrate added; this content is made up by water.

[0083] Difference in process phenomena: When the second phase is added to the first phase in step S3, due to the lack of ion inhibition, the reverse emulsion thickener (PC305A) undergoes explosive swelling upon contact with hot water at 65-70℃.

[0084] Comparative Example 5:

[0085] The difference compared to Example 2 is as follows:

[0086] The process differs: temperature difference mixing is eliminated. In step S3, the second phase (glycerol / DPG / PC305A) is also preheated to 70°C, then mixed with the first phase under constant temperature of 70°C, and then cooled uniformly.

[0087] Test Examples 1-4:

[0088] Test Example 1: Basic Physicochemical Properties and Stability Test

[0089] This section examines the massage oil samples prepared in Examples 1, 2, and 3 using routine physicochemical tests and stability studies under extreme conditions. The aim is to verify the process feasibility and structural stability of the system under different parameter gradients.

[0090] Experimental steps:

[0091] Observe the appearance, transparency, and bubble formation of the sample in a transparent glass bottle. Prepare a 10% sample aqueous solution and measure the pH value at 25℃. Measure the viscosity using a rotational viscometer (No. 4 rotor, 6 rpm) in a 25℃ constant temperature water bath. Centrifuge the sample at 3000 rpm for 30 minutes. Perform heat resistance (48℃ / 24h), cold resistance (-15℃ / 24h), and three high-low temperature cycle tests (48℃ to -15℃, 12h each), observing layering, precipitation, and changes in state.

[0092] Experimental results:

[0093] The test data of the three sample examples were summarized, and the results are shown in Table 1.

[0094] Table 1 Summary of Basic Physicochemical and Stability Test Data for Examples 1-3

[0095] Testing items Example 1 Example 2 Example 3 Appearance A translucent, uniform, oily fluid without bubbles. A translucent, high-gloss oily fluid Slightly milky white, with a thick, creamy texture pH value (25℃) 6.12 5.95 5.88 Viscosity (mPa·s, 25℃) 34,250 48,550 68,900 Centrifugation stability (3000 rpm) No stratification, no precipitation No stratification, no precipitation No stratification, no precipitation Heat resistance stability (48℃ / 24h) Stable, viscosity slightly decreased but recoverable. Stable, no water separation Stable, with no significant changes. Cold resistance stability (-15℃ / 24h) Stable, becomes transparent after returning to room temperature Stable, structure remains intact Stable, with occasional very slight turbidity. Cycle stability (3 cycles) pass pass pass

[0096] in conclusion:

[0097] In Examples 1 to 3, the viscosity increased gradually with increasing solid content, from 34,250 mPa·s to 68,900 mPa·s, while the pH value remained stable between 5.8 and 6.2. No stratification, water separation, or demulsification occurred in any of the samples under centrifugation, heat resistance, cold resistance, and cyclic temperature variations. Data shows that even under high PC305A concentrations (3.0%) and electrolyte conditions, the process of first inhibiting dispersion and then controlling swelling can construct a stable homogeneous system. The physical cross-linking network formed by the xanthan gum helical structure and polyols has sufficient cohesive force to bind high concentrations of glycerol and dipropylene glycol, resulting in a stable oil-like physical form for the product.

[0098] Test Example 2: Sensory Evaluation Comparison Test

[0099] This section evaluates the human skin sensory properties of the samples prepared in Example 2 and Comparative Examples 1 to 5, aiming to clarify the specific effects of different formulation components and process conditions on the skin feel performance of the final massage oil product.

[0100] Experimental steps:

[0101] Twenty volunteers were selected for a blind test in a constant temperature and humidity environment (22℃, 50%RH). Volunteers washed their forearms and equilibrated them for 15 minutes. 0.5 mL of sample was applied to a 5cm × 5cm area on the inner forearm. Spreadability (1-10, 10 being extremely easy to spread), cushioning (1-10, 10 being a noticeable oil film support), and stickiness after 3 minutes of massage (1-10, 10 being extremely sticky) were assessed.

[0102] Experimental results:

[0103] The scores from the 20 volunteers were statistically processed, and the results are shown in Table 2.

[0104] Table 2 Summary of sensory evaluation data for Example 2 and Comparative Examples 1-5

[0105] Sample number Spreadability score Buffering feel rating Post-massage stickiness rating Example 2 8.7 8.9 2.3 Comparative Example 1 6.8 6.2 8.8 Comparative Example 2 8.1 5.4 4.1 Comparative Example 3 6.5 7.8 7.9 Comparative Example 4 4.3 4.8 3.5 Comparative Example 5 8.2 6.1 3.2

[0106] in conclusion:

[0107] Example 2's viscosity score (2.3) was lower than Comparative Example 1 (8.8) and Comparative Example 3 (7.9), indicating that the combination of dipropylene glycol and urea reduced the surface tension of the system after drying. Regarding cushioning, Example 2 (8.9) was superior to Comparative Example 2 (5.4) and Comparative Example 5 (6.1). Completely cold mixing (Comparative Example 2) and constant-temperature mixing (Comparative Example 5) failed to form a tight interpenetrating network, resulting in a thin feel. In terms of spreadability, Comparative Example 4 had the lowest score (4.3) due to localized gel aggregation caused by the lack of sodium citrate. The data indicate that the combination of chemical additives and physical field processes solved the viscosity and rheological defects of the high-glycerol formulation, improving the product's oil-like feel.

[0108] Test Example 3: Rheological Thixotropy Test

[0109] This section uses rheological methods to characterize the shear sensitivity and structural recovery ability of the microstructure of massage oil samples, in order to verify the differences in the strength of the imitation oil gel network formed under different process conditions.

[0110] Experimental steps:

[0111] A three-stage thixotropic scan was performed using a rotational rheometer (40 mm cone plate, 0.052 mm gap, 25°C): First stage 0.1 s -1 Shearing for 60 seconds (measuring initial viscosity); second stage: 1000 seconds. -1 Shearing for 60 seconds (measuring the destructive viscosity); third stage recovery to 0.1s. -1 Scan for 180 seconds (measure recoverable viscosity). Calculate the structural recovery rate.

[0112] Experimental results:

[0113] Example 2 and Comparative Examples 1, 2, 4 and 5 were selected for testing, and the results are summarized in Table 3.

[0114] Table 3 Viscosity data and recovery rate of each sample in the three-stage thixotropic test

[0115] Sample number Initial viscosity (mPa·s) High shear viscosity (mPa·s) Recovery viscosity (mPa·s) Structural recovery rate (%) Example 2 46,215 856 41,362 89.5 Comparative Example 1 38,440 612 24,985 65 Comparative Example 2 18,320 430 9,892 54 Comparative Example 4 32,105 588 18,620 58 Comparative Example 5 36,550 720 26,680 73

[0116] in conclusion:

[0117] Example 2 showed a structural recovery rate of 89.5%, higher than Comparative Example 5 (73.0%) and Comparative Example 2 (54.0%). The rapid viscosity recovery after high shear stress in Example 2 indicates that xanthan gum and PC305A formed a physically interpenetrating network. The thermostatic mixing process utilizes the conformational change during cooling to lock PC305A within the network, resulting in a structure with higher resistance to shear disturbances compared to isothermal mixing (Comparative Example 5) and cold mixing (Comparative Example 2). The high recovery rate enables the product to rapidly rebuild its oil film structure after massage ceases, preventing flow and stringing.

[0118] Test Example 4: Long-lasting moisturizing performance test

[0119] This section aims to quantitatively evaluate the stratum corneum hydration maintenance capacity of the technical solution in Example 2 over a long period, verify whether the moisturizing efficacy of the formulation system is affected after reducing the glycerin concentration and introducing dipropylene glycol and urea, and the barrier effect of the interpenetrating network structure on moisture loss.

[0120] Experimental steps:

[0121] Twelve volunteers washed their forearms and equilibrated them for 30 minutes in a temperature and humidity controlled chamber (21℃, 45%RH). Baseline hydration levels were measured. A 2.0 mg / cm³ solution was applied to different areas. 2 Example 2, Comparative Example 1, Comparative Example 3, and a blank control were included. The stratum corneum moisture content was measured using a skin moisture meter at 4 and 8 hours after application.

[0122] Experimental results:

[0123] Measurement data from 12 volunteers were compiled, and the average stratum corneum moisture content at each time point was calculated. The results are shown in Table 4.

[0124] Table 4. Results of skin stratum corneum moisture content test for each group of samples (unit: AU)

[0125] Group base value 4-hour measurement 8-hour measurement 8-hour water content increase Example 2 36.4 68.2 54.7 18.3 Comparative Example 1 35.8 65.1 50.9 15.1 Comparative Example 3 36.1 66.8 51.5 15.4 Blank control 35.5 36.2 34.8 -0.7

[0126] in conclusion:

[0127] Example 2 showed a higher water content increment at T8h (18.3%) than Comparative Example 1 (15.1%) and Comparative Example 3 (15.4%). Although the glycerol content in Example 2 was reduced to 32%, the addition of dipropylene glycol and urea compensated for the reduced hygroscopic capacity. Compared to Comparative Example 3, the interpenetrating network structure formed in Example 2 was denser, creating a semi-permeable oil-like film on the skin surface and increasing resistance to transdermal water diffusion. The formulation, through polyol blending and structural closure mechanisms, improved skin feel while maintaining long-lasting moisturizing performance.

Claims

1. A body massage oil, characterized in that, Made from raw materials comprising the following percentages by weight: Glycerin 24.0%–36.0%; Dipropylene glycol 7.0%–16.0%; Inverse emulsion thickener PC305A 1.8%~3.2%; Xanthan gum 0.25%–0.65%; Urea 0.08%~0.60%; Sodium citrate 0.04%–0.25%; Disodium ethylenediaminetetraacetate 0.01%–0.15%; Preservative RP-11: 0.20%–0.60%; Fragrance content: 0.05%–0.40%; The remainder is deionized water.

2. The body massage oil according to claim 1, characterized in that, This body massage oil is made from ingredients comprising the following percentages by weight: Glycerin 32.0%; Dipropylene glycol 10.0%; Inverse emulsion thickener PC305A 2.4%; Xanthan gum 0.45%; Urea 0.20%; Sodium citrate 0.10%; Disodium ethylenediaminetetraacetate 0.05%; Preservative RP-110.40%; Fragrance 0.20%; The remainder is deionized water.

3. The body massage oil according to claim 1, characterized in that, The body massage oil is prepared by a method comprising the following steps: S1. Dissolve disodium ethylenediaminetetraacetate, sodium citrate and urea in deionized water, heat to 65-75°C, add xanthan gum under shear conditions, and stir at a constant temperature until a transparent hot solution is formed. S2. Mix glycerol and dipropylene glycol, control the temperature at 20-25℃, add reverse emulsion thickener PC305A, and stir to disperse to obtain a low-temperature suspension slurry. S3. Keep the temperature of the hot solution obtained in step S1 at 65-75°C, and slowly add the low-temperature suspension slurry obtained in step S2. After the addition is completed, maintain the temperature and stir to mix. S4. Turn on the cooling and keep stirring continuously during the cooling process until the temperature drops below 45°C; S5. Add fragrance and preservative RP-11, stir evenly, cool and discharge to obtain the body massage oil.

4. The body massage oil according to claim 1, characterized in that, The chemical composition of the reverse emulsion thickener PC305A includes polyacrylamide, C13-14 isoparaffins, and lauryl ether-7; the chemical composition of the preservative RP-11 includes phenoxyethanol, methylparaben, and ethylhexylglycerin.

5. The body massage oil according to claim 1, characterized in that, The mass ratio of glycerol to dipropylene glycol is (2.3-3.2):1; the mass ratio of sodium citrate to reverse emulsion thickener PC305A is 1:(15-40).

6. The body massage oil according to claim 3, characterized in that, In step S1, the shearing conditions are a homogenizer speed of 1500-2500 rpm and a constant temperature stirring time of 20-30 minutes.

7. The body massage oil according to claim 3, characterized in that, In step S2, the stirring conditions are: stirring paddle speed of 300-500 rpm and stirring and dispersion time of 5-10 minutes.

8. The body massage oil according to claim 3, characterized in that, In step S3, the mixing method during mixing is frame-type scraping wall stirring, with a rotation speed of 40-60 rpm; the feeding time is controlled at 3-5 minutes, and the stirring time after the feeding is completed is 10-15 minutes.

9. The body massage oil according to claim 3, characterized in that, In step S4, continuous stirring is maintained while the temperature drops from 55°C to 50°C.

10. The body massage oil according to claim 3, characterized in that, In step S4, the cooling process controls the cooling rate to be 1.0 to 2.0 °C / min.