Oil-control moisturizing pressed powder with multi-layer microporous structure and preparation method of oil-control moisturizing pressed powder

Abstract

The invention relates to the technical field of cosmetics, and particularly discloses an oil-control moisturizing pressed powder with a multi-layer microporous structure and a preparation method of the oil-control moisturizing pressed powder. The oil-control moisturizing pressed powder with the multi-layer microporous structure is characterized by comprising powder, a first emulsion and a second emulsion, the first emulsion is prepared by mixing a first humectant, hydrogenated lecithin, C12-20 acid PEG-8 ester, polysorbate-80 and water; the second emulsion is formed by mixing a second humectant and water; the preparation method comprises the following steps: mixing and drying the powder and the first emulsion, and then mixing with the second emulsion to obtain slurry; and freeze-drying the slurry at-80 to-60 DEG C, then freeze-drying at-40 to-5 DEG C, and finally freeze-drying at-5 to 45 DEG C to obtain the pressed powder. A uniform three-dimensional micropore structure is formed in the oil-controlling and moisturizing pressed powder, more moisturizing components can be loaded, the contact area with the skin is increased, and therefore the oil-controlling and moisturizing pressed powder has excellent moisturizing performance and skin feeling.

Description

Technical Field

[0001] The present application relates to the technical field of cosmetics, and more specifically, to an oil-controlling moisturizing powder with a multi-layer microporous structure and a preparation method thereof. Background Art

[0002] Cosmetic pressed powder is a common solid powder cosmetic, mainly used for facial makeup, concealing blemishes, adjusting skin tone and controlling oil.

[0003] Traditional pressed powder is usually composed of a mixture of a powder matrix, colorant, adhesive and functional additives. During the production of traditional pressed powder, the powder matrix must first be crushed and mixed, and then the colorant, adhesive and functional additives are added. After high-speed mixing, a mixed powder is formed, which is then pressed into shape.

[0004] However, directly pressing the mixed powder into a compact form results in densely packed powder particles, resulting in a low-porosity structure. This low-porosity pressed powder tends to form a uniform film on the skin's surface. While this effectively reduces oil diffusion and provides excellent oil control, it also makes it difficult for surface moisture to penetrate the stratum corneum. Consequently, the pressed powder may absorb the skin's own moisture, exacerbating dryness. Summary of the Invention

[0005] In order to improve the moisturizing and oil-control effects of pressed powder, the present application provides an oil-control moisturizing pressed powder with a multi-layer microporous structure and a preparation method thereof.

[0006] In the first aspect, the present application provides an oil-controlling moisturizing powder with a multi-layer microporous structure, which adopts the following technical solution: An oil-controlling moisturizing pressed powder with a multi-layer microporous structure, comprising a powder, a first emulsion and a second emulsion; The powder is composed of the following components in percentage by weight: Adsorbent 25-35%; Filler 15-20%; Film-forming agent 1.5-3%; Colorant 45-50%; The first emulsion is composed of the following components in percentage by weight: First moisturizing agent 0.5-1.2%; First emollient 6-8%; Hydrogenated lecithin 0.3-0.5%; C12-20 acid PEG-8 ester 0.8-1.5%; Polysorbate-80 0.3-0.5%; Water is the balance; The second emulsion is composed of the following components in percentage by weight: Second moisturizer 2.3-3.2%; Thickener 0.8-1.7%; Suspension agent 0.8-1.2%; Emulsifier 3.7-4%; Second emollient 5.5-6.5%; Water is the balance.

[0007] Currently, commercially available pressed powders are produced using not only dry powder compaction but also baking and solidification methods, where the powder is mixed with a small amount of liquid and then baked into shape. While baking and solidification improves skin adhesion, the high temperature can easily destroy the active ingredients and makes it difficult to achieve a high liquid content.

[0008] By adopting the above technical solution, on the one hand, the first emulsion and the second emulsion contain moisturizing ingredients and other active ingredients. Therefore, adding the first emulsion and the second emulsion to the powder can effectively improve the moisturizing properties of the prepared pressed powder, thereby obtaining a pressed powder with both moisturizing and oil-control effects.

[0009] On the other hand, the hydrogenated lecithin and polysorbate 80 in the first emulsion can form a stable oil-in-water (O / W) emulsion. After mixing with the powder and the second emulsion, the powder can be evenly dispersed to form microspheres, which then gather together to form an interlayer lamellar structure. This can slow down the volatilization of moisturizing ingredients and other active ingredients in the powder during baking or drying, increase the content of moisturizing ingredients and other active ingredients in the powder, and thus improve the moisturizing effect of the powder.

[0010] At the same time, the combination of C12-20 acid PEG-8 ester and polysorbate 80 can reduce the interfacial tension between powder and emulsion, so that the powder particles are completely wrapped by the emulsion, effectively improving the agglomeration of powder after drying, which is beneficial to improving the moisturizing effect of the powder.

[0011] Therefore, the powder prepared in the present application has a multi-layered sheet structure and a high content of moisturizing ingredients and other active ingredients, so it has both excellent moisturizing and oil-control effects. After applying makeup, a light, skin-fitting, powder-free, and soft-focus feel can be obtained.

[0012] Preferably, the weight ratio of the powder to the first emulsion is 1:(1-1.3).

[0013] By adopting the above technical solution, a slightly excessive amount of the first emulsion is used to pre-mix the powder, which can improve the dispersibility of the powder in the first emulsion, facilitate the formation of an interlayer lamellar structure, and help further improve the moisturizing performance of the powder.

[0014] Preferably, in the powder, the adsorbent is silica.

[0015] By adopting the above technical solution, silica can effectively absorb oil, and the pressed powder made with silica can achieve long-lasting oil control (oil control rate ≥90% for 8 hours).

[0016] Preferably, in the powder, the film-forming agent is HDI / trimethylol hexyl lactone polymer.

[0017] By adopting the above technical solution, HDI / trimethylol hexyl lactone polymer forms an elastic network through cross-linking structure, which can improve the "dry feeling" of pressed powder and make it feel smoother.

[0018] Preferably, in the powder, the filler is triethoxyoctylsilane-modified mica.

[0019] By adopting the above technical solution, triethoxycaprylylsilane modification can improve the hydrophobicity of triethoxycaprylylsilane-modified mica, effectively improve powder agglomeration, and help enhance the soft-focus concealing effect of the resulting powder.

[0020] Preferably, in the powder, the colorant is a mixture of synthetic fluorphlogopite and pearlescent mica.

[0021] By employing this technical solution, synthetic fluorphlogopite possesses a high refractive index, enabling pressed powders to brighten the complexion without a metallic shimmer. Pearlescent mica, a tin oxide-modified mica, imparts a natural luster to pressed powders, effectively mitigating the metallic, white cast often associated with traditional pearlescent powders. Furthermore, by combining synthetic fluorphlogopite and pearlescent mica with varying particle sizes, a natural, three-dimensional finish is achieved, effectively mitigating the perceived flatness of a single powder.

[0022] Preferably, in the first emulsion, the first emollient comprises pentaerythritol tetraisostearate.

[0023] By adopting the above technical solution, pentaerythritol tetraisostearate (CRODAMOL PTIS), a high refractive index oil, can enhance skin gloss and improve powder adhesion.

[0024] Preferably, in the second emulsion, the thickener is composed of a mixture of xanthan gum and wrinkled carrageenan, sodium chloride and seawater.

[0025] Preferably, in the second emulsion, the suspending agent is magnesium aluminum silicate.

[0026] By adopting the above technical solution, the mixture of xanthan gum and wrinkled carrageenan has a synergistic thickening effect with magnesium aluminum silicate, which can improve powder sedimentation and enhance slurry fluidity (viscosity is controlled at 5000-8000 cP). The addition of sodium chloride and seawater further activates the thickener to form a thixotropic structure, which is conducive to the formation of a multi-layered flaky structure and improves the moisturizing performance and oil-control effect of the pressed powder.

[0027] In this application, the first emulsion contains a high content of aqueous phase, which offers excellent moisturizing properties. The thickener and suspending agent contained in the second emulsion form a thickening suspension system. Therefore, mixing the powder with the emulsion system of the first and second emulsions allows the powder to be evenly dispersed into a multilayered, flaky structure, further enhancing the moisturizing and oil-control properties of the powder. Furthermore, in this emulsion system, the triethoxycaprylylsilane-modified mica in the powder forms small pores during mixing, increasing the distance between the layers and enhancing the air permeability of the powder, which helps improve the skin feel.

[0028] Preferably, in the second emulsion, the second moisturizing agent includes glycerin.

[0029] Preferably, in the second emulsion, the second emollient is a mixture of cetearyl ethylhexanoate and squalane.

[0030] By adopting the above technical solution and compounding light oils, the moisturizing and breathability of the powder can be balanced, effectively improving acne.

[0031] Furthermore, the powder in this application uses silicone oil for oil control, while the second emulsion uses glycerin and squalane for moisturizing. Compared to traditional baking powders, the resulting pressed powder reduces skin moisture loss by at least 31% over 24 hours and increases oil absorption by at least 20% over 8 hours. Therefore, the pressed powder produced in this application achieves oil control without drying out the skin.

[0032] In a second aspect, the present application provides a method for preparing an oil-controlling moisturizing powder with a multi-layer microporous structure, using the following technical solution: A method for preparing an oil-controlling moisturizing pressed powder with a multi-layer microporous structure, comprising the following steps: S1: Preparation of powder: adsorbent, filler, film-forming agent and colorant are stirred and mixed to obtain powder; Preparation of the first emulsion: a first moisturizer, hydrogenated lecithin, and water are stirred and mixed at 60-80° C. to obtain an aqueous phase; a first emollient, a surfactant, C12-20 acid PEG-8 ester, and polysorbate 80 are stirred and mixed at 50-70° C. to obtain an oil phase; the oil phase is added to the aqueous phase, stirred and mixed, and homogenized to obtain the first emulsion; Preparation of the second emulsion: stirring and mixing the second moisturizing agent, thickener, suspending agent, emulsifier, second emollient and water, and homogenizing to obtain the second emulsion; S2: After mixing the powder and the first emulsion, drying to a moisture content of ≤1.5% to obtain a mixed powder; S3: After mixing the second emulsion and the mixed powder, stir and mix at 5-10 MPa for 2-3 times, each time for 5-10 minutes, to obtain a slurry; S4: The slurry is first freeze-dried at -80 to -60°C for 50 to 70 minutes, then freeze-dried at -40 to -5°C for 11 to 13 hours, and finally freeze-dried at -5 to 45°C for 9 to 11 hours to obtain an oil-controlling moisturizing powder with a multi-layer microporous structure.

[0033] By adopting the above technical solution, the slurry prepared according to the above steps can form a multi-layer lamellar structure. Then, the slurry is pre-frozen (-80 to -60°C), mainly dried (-40°C to -5°C) and analytically dried (-5 to 45°C) to fix the multi-layer lamellar structure of the slurry and form a uniform three-dimensional microporous structure inside each layer of the lamellar structure. On the one hand, the microporous structure can load more moisturizing ingredients (such as glycerin and squalane) and release them slowly, thereby improving the drying problem of traditional powder cakes. On the other hand, the microporous structure can enhance the contact area between the powder cake and the skin, improve the ductility and fit of the powder cake, and improve the "floating powder" problem of traditional powder cakes.

[0034] At the same time, the powder cake prepared by this application adopts ultra-low temperature phase change drying technology, and adopts low-temperature treatment (≤80°C) throughout the process, which avoids oil oxidation or inactivation of heat-sensitive ingredients (such as plant squalane and hydrogenated lecithin) caused by high-temperature baking, eliminates the risk of oil rancidity, and improves the stability of the powder cake.

[0035] Preferably, the weight ratio of the powder to the first emulsion is 1:(1-1.3); the second emulsion and the mixed powder are mixed in a weight ratio of (0.6-1):1.

[0036] In summary, this application has the following beneficial effects: 1. Since the present application uses the first emulsion and the second emulsion as an emulsion system to be mixed with the powder, the hydrogenated lecithin and polysorbate 80 in the first emulsion can form a stable oil-in-water emulsion. After mixing, a multi-layered sheet structure can be formed, which is beneficial for increasing the content of active ingredients in the pressed powder, thereby obtaining a pressed powder with both moisturizing and oil-control effects. After application, the pressed powder has a light, powder-free, and soft-focus feel. 2. In this application, C12-20 acid PEG-8 ester compounded with polysorbate 80 is used as an emulsifier, which can reduce the interfacial tension between the powder and the emulsion, causing most of the powder particles to be wrapped by the emulsion, forming a powder with a multi-layer microporous network structure, which is beneficial for the silicone oil in the powder to be combined with the active ingredients of glycerin and squalane to control oil and moisturize the skin, thereby improving the moisturizing and oil-control effects of the powder; 3. The method of the present application, by adopting ultra-low temperature phase change drying, can fix the multi-layer morphology of the slurry and form a three-dimensional microporous network structure, thereby effectively improving the moisturizing and skin-fitting properties of the powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1This is an electron micrograph of the oil-controlling moisturizing powder with a multi-layer microporous structure in Example 1 of the present application; Figure 2 This is an electron micrograph of the powder in Comparative Example 1 of the present application; Figure 3 This is an electron micrograph of the powder in Comparative Example 2 of the present application; Figure 4 This is an electron micrograph of the powder compact in Comparative Example 3 of the present application; Figure 5 This is an electron micrograph of the powder in Comparative Example 4 of the present application; Figure 6 This is an electron micrograph of the powder compact in Comparative Example 5 of the present application; Figure 7 This is a SEM electron microscope structure diagram of the oil-control moisturizing powder with a multi-layer microporous structure in Example 1 of the present application; Figure 8 This is a SEM electron microscope structure diagram of the powder in Comparative Example 1 of the present application. DETAILED DESCRIPTION

[0038] The present application is further described in detail below with reference to the accompanying drawings and examples.

[0039] The components used in the examples of this application are commercially available except for the following special instructions; Performance testing The oil-control moisturizing pressed powder with a multi-layer microporous structure prepared in the examples of the present application and the pressed powder prepared in the comparative example were used as samples to test skin feel, friction coefficient, microstructure, accelerated aging, moisturizing properties, oil control, light transmittance, haze, skin feel, and layered structure. The testing methods are as follows: Skin feel test: Friction coefficient test: Microstructure testing: Accelerated aging test: Moisturizing, oil control, light transmittance, haze and skin feel testing, the testing methods are as follows: The scoring criteria and operating procedures of the tape method for layered structures are as follows: 1. Sample preparation specifications 2. Microscope observation parameters 3.100μm scale scoring standard Equipment model used during the test: Texture analyzer: TA.XT Plus (Stable Micro Systems); Skin profiler: Keyence VR-5000 (accuracy 0.1 μm); Friction tester: TRIBOGEAR (Heidon-18 model); White light interferometer: Bruker ContourGT-K (vertical resolution 0.1 nm); Micro-CT: ZEISS Xradia 520Versa (voltage 80 kV, power 7 W).

[0040] All tests were carried out under a standard environment of 25℃±1℃ and 50%±5%RH, and each sample was tested three times in parallel to obtain the average value. Example

[0041] Example 1 An oil-controlling moisturizing pressed powder with a multi-layer microporous structure, the components and their corresponding weights (kg) are shown in the following table.

[0042] The method for preparing the oil-controlling moisturizing pressed powder with a multi-layer microporous structure comprises the following steps: S1: Preparation of powder: an adsorbent, a filler, a film-forming agent, and a colorant were stirred and mixed at 800 rpm for 25 minutes to obtain a powder; Preparation of the first emulsion: a first moisturizer, hydrogenated lecithin, and water were stirred and mixed at 70°C and 300 rpm for 15 minutes to obtain an aqueous phase; a first emollient, a surfactant, C12-20 acid PEG-8 ester, and polysorbate 80 were stirred and mixed at 60°C and 200 rpm for 10 minutes to obtain an oil phase; the 65°C oil phase was added to the 70°C aqueous phase, stirred and mixed at 500 rpm for 5 minutes, and then homogenized at 5000 rpm for 3 minutes to obtain a first emulsion; Preparation of the second emulsion: The second moisturizing agent, thickener, suspending agent, emulsifier, second emollient and water were stirred and mixed at 400 r / min for 20 minutes, and then homogenized at 6000 r / min for 5 minutes to obtain the second emulsion.

[0043] S2: The powder and the first emulsion were stirred and mixed at 600 rpm for 30 min, and dried at 70°C until the moisture content was ≤1.5% to obtain a mixed powder; In the embodiment of the present application, the weight ratio of the powder to the first emulsion is 1:1.

[0044] S3: The second emulsion and the mixed powder were stirred at 400 r / min for 20 min and at 8 MPa for 3 times, each time for 8 min, to obtain a slurry; In the embodiment of the present application, the weight ratio of the second emulsion to the mixed powder is 9:10.

[0045] S4: The slurry is first freeze-dried at -70°C for 60 minutes to obtain a pre-frozen slurry; the pre-frozen slurry is then freeze-dried at -30°C for 12 hours to obtain a main-dried slurry; finally, the main-dried slurry is freeze-dried at 20°C for 10 hours to obtain an oil-control moisturizing powder with a multi-layer microporous structure.

[0046] Examples 2-3 An oil-controlling moisturizing pressed powder with a multi-layer microporous structure is different from Example 1 in that the components and their corresponding weights (kg) are shown in the following table.

[0047] The moisturizing, oil-controlling, oil-controlling, light transmittance, haze and friction coefficient tests were performed on the oil-controlling, moisturizing pressed powder with a multi-layer microporous structure prepared in Examples 1 to 3 of the present application. The test results are shown in the following table.

[0048] By analyzing the data in the above table, it can be seen that the oil-controlling moisturizing powder with a multi-layer microporous structure prepared in Examples 1 to 3 of the present application has excellent moisturizing and oil-control properties, and has low transmittance, haze and friction coefficient. After use, it has a high skin-fitting property, a light and thin skin feel, and a soft-focus effect.

[0049] Comparative Example Comparative Example 1 A commercially available pressed powder is composed of 48.9% talc, 20% mica, 6% silica, 4% nylon-12, 11.3% color powder, and 7.8% silicone oil emollient.

[0050] The preparation method of the commercially available pressed powder comprises the following steps: A1: Place talc, mica, and silica into a mixing pot and mix at 8000 rpm for 3 seconds twice to obtain Phase A. A2: Add the color powder to phase A and stir at 8000 rpm for 3 times, each time for 3 seconds to obtain the colored phase A; A3: Stir the silicone emollient and nylon-12 until evenly combined and add to the pigmented phase A. Mix at 6000 rpm for 3 times, each time for 3 seconds, to obtain a mixture. A4: The mixture was pressed into a compact (pressure 10 MPa, holding pressure for 5 seconds) to obtain a commercially available pressed powder.

[0051] The pressed powders prepared in Example 1 and Comparative Example 1 of the present application were subjected to skin feel testing, and the test results are shown in the following table.

[0052] Analysis of the table above shows that the pressed powder prepared using the freeze-drying process in Example 1 of the present application is lighter, adheres to the skin, and spreads easily compared to the pressed powder prepared using the traditional heat treatment in Comparative Example 1. Conventional pressed powder, on the other hand, has low spreadability and is prone to clumping or powder floating.

[0053] The friction coefficient of the powder prepared in Example 1 and Comparative Example 1 of the present application was tested, and the test results are shown in the following table.

[0054] By analyzing the above table, it can be seen that the powder foundation prepared by the freeze-drying process in Example 1 of the present application has a lower friction coefficient than the powder foundation treated by traditional heat treatment in Comparative Example 1. When applying makeup, it can slide more smoothly and is not easy to get stuck or fall off, thereby providing a more natural makeup effect and a better sense of fit.

[0055] The powder cakes prepared in Example 1 and Comparative Example 1 of the present application were tested for microstructure and performance, and the test results are shown in the following table.

[0056] Through analysis of the above table, it can be seen that the powder cake prepared by freeze-drying process in Example 1 of the present application has lower surface roughness than the powder cake treated by traditional heat treatment in Comparative Example 1, and has a multi-layer structure with uniform pore distribution, and has the effect of oil control and moisturizing.

[0057] The pressed powders prepared in Example 1 and Comparative Example 1 of the present application were subjected to accelerated aging tests, and the test results are shown in the following table.

[0058] By analyzing the above table, it can be seen that the powder cake prepared by freeze-drying process in Example 1 of the present application has higher stability and is not easy to age compared with the powder cake treated by traditional heat treatment in Comparative Example 1. The reason for this may be that the multi-layer structure of the powder cake of the present application inhibits the migration of active ingredients, so it is not easy to age, while the surface oxidation of the powder cake treated by traditional heat treatment is aggravated under ultraviolet irradiation, so it is more prone to aging.

[0059] Comparative Example 2 A pressed powder, which differs from Example 1 in that an equal weight of soybean lecithin is used instead of hydrogenated lecithin, and an equal weight of sucrose stearate is used instead of polysorbate 80.

[0060] Comparative Example 3 A pressed powder, which differs from Example 1 in that an equal weight of dimethicone is used instead of pentaerythritol tetraisostearate, wherein the dimethicone is Dow Corning DC 200-100 cSt.

[0061] Comparative Example 4 A pressed powder, which differs from Example 1 in that the preparation method of the pressed powder is the same, and step S4 is: freeze-drying the slurry at -70°C for 60 minutes to obtain a pre-frozen slurry; freeze-drying the pre-frozen slurry at -30°C for 22 hours to obtain an oil-controlling and moisturizing pressed powder with a multi-layer microporous structure.

[0062] Comparative Example 5 A pressed powder, which differs from Example 1 in that the preparation method of the pressed powder is the same, and step S4 is: freeze-drying the slurry at -70°C for 60 minutes to obtain a pre-frozen slurry; freeze-drying the pre-frozen slurry at 25°C for 22 hours to obtain an oil-controlling and moisturizing pressed powder with a multi-layer microporous structure.

[0063] The pressed powders prepared in Comparative Examples 1 to 5 of the present application were tested for moisturizing properties, oil control properties, pressed powder hardness, and layered structure integrity. The test results are shown in the following table.

[0064] Depend on Figure 1 It can be seen that the structural characteristics of the powder prepared in Example 1 of the present application are: Gradient Directed Assembly: Low-temperature phase separation forms a continuous layered matrix with a single layer thickness of 8-10 μm and an interlayer spacing of 15-18 μm. Functionalized Microsphere Positioning: Surface-modified microspheres (1-5 μm in diameter) are aligned along the interlayers to form a densely packed honeycomb structure. The layered structure has excellent integrity.

[0065] Depend on Figure 2 It can be seen that the pressed powder prepared in Comparative Example 1 has the following structural characteristics: Disordered dense packing: Powder particles (particle size 5-20μm) are randomly agglomerated and have no directional layered characteristics.

[0066] Non-functionalized microsphere network: The surface-treated microspheres are randomly dispersed without honeycomb arrangement.

[0067] Depend on Figure 3 As can be seen, the pressed powder prepared in Comparative Example 2 exhibits a less layered structure than in Example 1, with the regularity of the original continuous layered matrix reduced and the layered characteristics weakened in some areas. The surface-modified microspheres (particle size 1-5 μm) are dispersed, the orderliness of the interlayer orientation decreases, and the density and regularity of the densely packed structure decrease, resulting in a more sparse and disordered distribution. The layered structure has good integrity.

[0068] Depend on Figure 4 It can be seen that the pressed powder prepared in Comparative Example 3 has the following structural characteristics: Layered structure collapse: The original layered matrix is severely deformed, the layer thickness fluctuates violently (5-20 μm), the interlayer spacing expands disorderly (10-50 μm), and the layer structure in some local areas completely disappears; the layered structure has poor integrity.

[0069] Microsphere network: The honeycomb microsphere network is destroyed to form irregular closed cells.

[0070] Depend on Figure 5 It can be seen that the pressed powder prepared in Comparative Example 4 has the following structural characteristics: Intermittent lamellar assembly: Low-temperature phase separation forms a local lamellar structure (single layer thickness 6-14 μm), with significant interlayer fluctuations (10-30 μm); Microsphere network degradation: The microsphere network is partially preserved but with irregular morphology. The lamellar structure is moderately intact.

[0071] Depend on Figure 6 It can be seen that the pressed powder prepared in Comparative Example 5 has the following structural characteristics: Layered structure collapse: The original layered matrix is severely deformed, the layer thickness fluctuates violently (5-20 μm), the interlayer spacing expands disorderly (10-50 μm), and the layer structure in some local areas completely disappears; the layered structure has poor integrity.

[0072] Microsphere network: The microsphere network is destroyed to form an irregular network.

[0073] Depend on Figure 7 It can be seen that the pressed powder prepared in Example 1 has the following structural characteristics: During the liquid nitrogen quick freezing (-70°C), the microspheres migrate along the surface energy gradient, achieving micron-level positioning accuracy and inhibiting agglomeration caused by Brownian motion.

[0074] Depend on Figure 8 It can be seen that the powder cake prepared in Comparative Example 1 has the following structural characteristics: the powder particles are randomly agglomerated and have no directional layered characteristics.

[0075] Analysis of the data in the table above shows that, compared to Example 1, Comparative Example 1 exhibited increased 24-hour transepidermal water loss, decreased 8-hour oil absorption, and reduced powder hardness. This demonstrates that the powder prepared using the freeze-drying process exhibits better moisturizing and oil-control properties, and is less brittle, compared to the powder prepared using conventional heat treatment in Comparative Example 1.

[0076] Compared to Example 1, Comparative Example 2 showed an increased 24-hour transepidermal water loss, a decreased 8-hour oil absorption rate, and reduced powder hardness. This demonstrates that, in the preparation of the oil-control moisturizing powder with a multi-layer microporous structure of this application, the first emulsion, using hydrogenated lecithin and polysorbate 80, forms a stable O / W emulsion, ensuring uniform powder dispersion, thereby improving the moisturizing, oil-control, and hardness of the powder. However, in Comparative Example 2, due to the difference in HLB value between soy lecithin and hydrogenated lecithin, the emulsion stability in this application is poor, and the sucrose ester has insufficient low-temperature solubility, affecting the emulsion uniformity, thereby weakening the moisturizing and oil-control properties of the powder.

[0077] Compared to Example 1, Comparative Example 3 showed an increased 24-hour transepidermal water loss and decreased powder hardness. This demonstrates that the use of pentaerythritol tetraisostearate as an emollient in the first emulsion of the oil-control, moisturizing powder with a multi-layer microporous structure in this application not only enhances skin radiance but also improves powder adhesion, further increasing the moisturizing properties and hardness of the powder. However, the silicone oil in Comparative Example 3 was incompatible with the freeze-dried layered structure, resulting in a fragile powder.

[0078] Compared to Example 1, the 24-hour transepidermal water loss in Comparative Examples 4 and 5 increased, and the powder hardness decreased. This demonstrates that in the present method for preparing an oil-control, moisturizing powder with a multi-layer microporous structure, step S4 involves pre-freezing the slurry and then drying it, followed by desorption drying at -5 to 45°C. This creates a uniform, three-dimensional microporous structure within the powder, enhancing moisturizing, oil-control, and skin-fitting properties. This also prevents high temperatures from damaging the active ingredients, extending stability.

[0079] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed, but as long as they are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. An oil-controlling moisturizing pressed powder with a multi-layer microporous structure, characterized in that: comprising a powder, a first emulsion and a second emulsion; The powder is composed of the following components in percentage by weight: Adsorbent 25-35%; Filler 15-20%; Film-forming agent 1.5-3%; Colorant 45-50%; The first emulsion is composed of the following components in percentage by weight: First moisturizer 0.5-1.2%; First emollient 6-8%; Hydrogenated lecithin 0.3-0.5%; C12-20 acid PEG-8 ester 0.8-1.5%; Polysorbate-80 0.3-0.5%; Water is the balance; The second emulsion is composed of the following components in percentage by weight: Second moisturizer 2.3-3.2%; Thickener 0.8~1.7%; Suspension agent 0.8-1.2%; Emulsifier 3.7-4%; Second emollient 5.5-6.5%; Water is the balance.

2. The oil-controlling moisturizing pressed powder with a multi-layer microporous structure according to claim 1, characterized in that: The weight ratio of the powder to the first emulsion is 1:(1-1.3).

3. The oil-controlling moisturizing pressed powder with a multi-layer microporous structure according to claim 1, characterized in that: In the powder, the filler is triethoxyoctylsilane-modified mica.

4. The oil-controlling moisturizing pressed powder with a multi-layer microporous structure according to claim 1, characterized in that: In the powder, the colorant is composed of a mixture of synthetic fluorphlogopite and pearlescent mica.

5. The oil-controlling moisturizing pressed powder with a multi-layer microporous structure according to claim 1, characterized in that: In the second emulsion, the thickener is composed of a mixture of xanthan gum and wrinkled carrageenan, sodium chloride and seawater.

6. The oil-controlling moisturizing pressed powder with a multi-layer microporous structure according to claim 4, characterized in that: In the second emulsion, the suspending agent is magnesium aluminum silicate.

7. The oil-controlling moisturizing pressed powder with a multi-layer microporous structure according to claim 1, characterized in that: In the second emulsion, the second emollient is composed of a mixture of cetearyl ethylhexanoate and squalane.

8. The method for preparing the oil-controlling moisturizing pressed powder with a multi-layer microporous structure according to any one of claims 1 to 7, characterized in that: The following steps are involved: S1： Preparation of powder: adsorbent, filler, film-forming agent and colorant are stirred and mixed to obtain powder; Preparation of the first emulsion: a first moisturizer, hydrogenated lecithin, and water are stirred and mixed at 60-80° C. to obtain an aqueous phase; a first emollient, a surfactant, C12-20 acid PEG-8 ester, and polysorbate 80 are stirred and mixed at 50-70° C. to obtain an oil phase; the oil phase is added to the aqueous phase, stirred and mixed, and homogenized to obtain the first emulsion; Preparation of the second emulsion: stirring and mixing the second moisturizing agent, thickener, suspending agent, emulsifier, second emollient and water, and homogenizing to obtain the second emulsion; S2: After mixing the powder and the first emulsion, drying to a moisture content of ≤1.5% to obtain a mixed powder; S3: After mixing the second emulsion and the mixed powder, stir and mix at 5-10 MPa for 2-3 times, each time for 5-10 minutes, to obtain a slurry; S4: The slurry is first freeze-dried at -80 to -60°C for 50 to 70 minutes, then freeze-dried at -40 to -5°C for 11 to 13 hours, and finally freeze-dried at -5 to 45°C for 9 to 11 hours to obtain an oil-controlling moisturizing powder with a multi-layer microporous structure.

9. The method for preparing the oil-controlling moisturizing pressed powder with a multi-layer microporous structure according to claim 8, characterized in that: The second emulsion and the mixed powder are mixed in a weight ratio of (0.6-1):1.

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