Method for testing soft focus and covering power of cosmetics

Abstract

The invention relates to the technical field of cosmetics, and particularly discloses a method for testing soft focus and covering power of cosmetics. The invention discloses a method for testing soft focus and covering power of cosmetics. The method comprises the following steps: 1) placing a test sample on a transparent plate; (2) uniformly smearing the test sample to form a film with the thickness of 2-3 microns, and measuring the transmittance and the haze value; 3) printing characters on the paper, placing the transparent plate coated with the test sample on the paper, taking a picture in a light source box, recording the picture, taking the picture as a sample group, and taking the transparent plate as a blank control group; and 4) analyzing and processing the picture through ImageJ, integrating the optical density IntDen as a quantitative value for calculation, and recording a blank group IntDen as D0 and a sample group as D1, so that the covering power% is equal to (D0-D1) / D0 * 100%. According to the test method disclosed by the invention, objective quantitative data is provided, the deviation of subjective judgment is reduced, and the accuracy and repeatability of a test result are improved.

Description

Technical Field

[0001] The present application relates to the technical field of cosmetics, and more particularly, to a method for testing the soft focus and covering power of cosmetics. Background Art

[0002] Makeup is used to give skin color, modify skin color or strengthen the shadows of eyes and nose to enhance three-dimensional effect through color changes. At the same time, makeup can also be used to cover skin defects such as freckles, scars and moles to make the skin look smoother and more even.

[0003] Makeup usually includes base makeup products, eye products, lip products and setting makeup products. Base makeup products are used to even out skin tone, cover blemishes, and provide natural or high-coverage makeup effects. Testing the soft focus effect and coverage of base makeup products is an important part of makeup research and development and quality control. Existing methods for testing the soft focus and coverage of makeup usually use visual evaluation methods, in which professionals or trained assessors directly observe the skin after applying makeup to evaluate the coverage and soft focus effect.

[0004] This method can provide intuitive feedback and is flexible, but it relies too much on the subjective judgment of the assessor, which may vary between different assessors, resulting in limited repeatability and objectivity of the results. Summary of the invention

[0005] In order to improve the problem that the method of testing the soft focus and covering power of makeup by visual evaluation method relies on the subjective judgment of the evaluator, the present application provides a method for testing the soft focus and covering power of makeup.

[0006] In a first aspect, the present application provides a method for testing the soft focus and covering power of makeup, using the following technical solution: A method for testing the soft focus and covering power of makeup, characterized in that it comprises the following steps: 1) Place the transparent plate on the platform, weigh 2-4g of the test sample and place it on one end of the transparent plate for later use; 2) Apply the test sample evenly to form a film with a thickness of 2-3 μm, let it stand for 5-6 minutes, and measure the transmittance and haze value. Each test sample is measured 3-4 times in parallel and the average value is recorded; 3) Print words on paper, place the transparent plate coated with the test sample on the paper, take photos in a light box, and record the photos as the sample group, and the transparent plate as the blank control group; 4) The images were analyzed and processed by ImageJ, and the integrated optical density IntDen was calculated as the quantitative value. The blank group IntDen was recorded as D0, and the sample group was recorded as D1. Then, the covering power % = (D0-D1) / D0*100%.

[0007] By adopting the above technical solution, the test sample is evenly applied, and the image is analyzed and processed by ImageJ to test the covering power. This test method can provide objective quantitative data, reduce the deviation of subjective judgment, and improve the accuracy and repeatability of the test results. In addition, through image analysis, the covering power parameters of the skin color can be accurately measured, providing detailed quantitative indicators and improving test efficiency.

[0008] A method of evaluating the effect of makeup using image processing technology. By analyzing the images of the skin before and after applying the test sample, it can quantitatively evaluate characteristics such as hiding power and soft focus effect. The image analysis method can adapt to different testing needs. By adjusting the algorithm parameters, it can be optimized for specific test targets. Compared with some physical testing methods, the image analysis method is non-contact, will not cause physical damage to the skin, and is safer and more hygienic.

[0009] Optionally, in step 2), a wire rod applicator is used to slide evenly on the test sample at a constant speed to evenly apply the test sample.

[0010] By adopting the above technical solution, the wire rod applicator can provide a very uniform coating, which helps to accurately evaluate the hiding power, gloss and color consistency. Moreover, by adjusting the diameter and coil spacing of the wire rod, the thickness of the coating can be precisely controlled to ensure the same coating conditions each time, which is very important for the repeatability and quality control of the experiment, and can ensure the consistency of the test samples between different batches.

[0011] Optionally, in step 2), a haze meter is used to measure the transmittance and haze value of the test sample.

[0012] By adopting the above technical solution, the haze meter is an instrument specially used to measure the transmittance and haze value of transparent or translucent materials. The transmittance refers to the ratio of the intensity of light after passing through the material to the intensity of the incident light, usually expressed as a percentage; the haze value refers to the ratio of the scattered light flux passing through the material to the total transmitted light flux, which reflects the degree of scattering of the material and is also expressed as a percentage.

[0013] Optionally, the test sample includes one of cosmetic powder raw materials, liquid foundation, loose powder, and pressed powder.

[0014] By adopting the above technical solution, the test samples include various base makeup products with good covering power and naturalness.

[0015] Optionally, the cosmetic powder raw materials include W / O emulsion and powder treated with lauroyl lysine, and the powder includes pearl powder, mica, talc, silica, iron oxide and titanium dioxide.

[0016] By adopting the above technical solution, adding W / O emulsion to powders such as pearl powder can improve the dispersibility and adhesion of powders such as pearl powder, making them smoother and more natural on the transparent plate, so that they can better adhere to the transparent card.

[0017] Lauroyl lysine is a surfactant that can be used to treat pearl powder and other powders to improve their dispersibility and stability. Pearl powder and other powders treated with lauroyl lysine have better adhesion to transparent plates, which helps to better detect the covering power of cosmetic powder raw materials.

[0018] Optionally, the method for preparing the cosmetic powder raw material comprises the following steps: (1) mixing water and mineral oil, adding fatty acid ester, stirring uniformly at a temperature of 60-65° C., first stirring at a stirring rate of 5000-5500 r / min for 10-12 min, and then stirring at a stirring rate of 1000-1500 r / min for 5-8 min to obtain a W / O emulsion; (2) adding lauroyl lysine and powder to the W / O emulsion obtained in step (1), first homogenizing, and then ultrasonically treating, to obtain a cosmetic powder raw material, wherein the powder is pearl powder.

[0019] By adopting the above technical solution, water and mineral oil are immiscible. By adding fatty acid esters, water and oil are mixed together to form a stable emulsion. Fatty acid esters form a thin film on the interface of water and mineral oil, reducing surface tension, so that the water phase and the oil phase can be evenly dispersed to form an emulsified system. The formation of the emulsified system helps to improve the stability of the product and prevent water and oil separation. At the same time, the antioxidant properties of fatty acid esters and mineral oils can extend the shelf life of the product.

[0020] First, stir at high speed to promote the dispersion of the oil phase in the water phase to form fine droplets. As the emulsification process proceeds, the stirring rate can be gradually reduced to avoid destroying the emulsion structure that has been formed, and finally obtain a stable and uniform W / O emulsion.

[0021] Adding lauroyl lysine and pearl powder to the W / O emulsion, lauroyl lysine, as a surfactant, can improve the dispersibility of pearl powder in the system, ensure the uniform distribution of pearl powder, and enhance the stability of the W / O emulsion to prevent stratification. Moreover, after being treated with lauroyl lysine, pearl powder can provide a natural pearlescent effect for the product, enhance the covering power, make the skin tone look more even, and give the product a delicate luster and smooth touch.

[0022] The mixture of W / O emulsion, lauroyl lysine and pearl powder can provide moisturizing, stability, pearl effect and covering power in cosmetics, and improve skin feel, and is an important combination ingredient in cosmetic formulas. Finally, homogenization treatment is performed first, followed by ultrasonic treatment. Through the steps of homogenization treatment first and then ultrasonic treatment, the uniform dispersion of pearl powder in the emulsion can be ensured, the stability and skin feel of the emulsion can be improved, and the absorption effect of pearl powder can be enhanced, providing better nourishment and protection for the skin.

[0023] Optionally, the homogenization conditions are 7000-7500 rpm, 5-10 min; the ultrasonic conditions are 350-380 W / L, 6-8 min; and the high-pressure homogenization conditions are 100-110 MPa, 120-130 s.

[0024] By adopting the above technical solution, the homogenization and ultrasonic conditions are further limited. The homogenization process disperses the pearl powder evenly in the emulsion through high-speed shear force, ensuring the miniaturization and uniform distribution of the pearl powder particles, thereby improving the stability of the emulsion, preventing the precipitation of the pearl powder, and enhancing the gloss and skin feel of the product.

[0025] Ultrasonic treatment uses the cavitation effect of ultrasound to further refine pearl powder particles, improve its dispersion in the emulsion, and promote the combination of pearl powder with other ingredients in the emulsion, thereby enhancing the stability of the emulsion. Ultrasonic treatment can also promote the release of active ingredients, improve their bioavailability, and make the nutrients in pearl powder easier to be absorbed by the skin.

[0026] Preferably, the mass ratio of the mineral oil, lauroyl lysine and pearl powder is 1-1.5:0.5-0.7:1.

[0027] By adopting the above technical scheme, the mass ratio of mineral oil, lauroyl lysine and pearl powder is further limited within a certain range, and the obtained pretreated pearl powder has good dispersibility, hiding power and stability. Mineral oil, as an oily component, has good sealing and moisturizing properties, and can form a protective film to prevent skin moisture evaporation and keep the skin soft and smooth.

[0028] As a surfactant, lauroyl lysine can be used as an emulsifier to help mineral oil and pearl powder form a stable emulsion system in the water phase. At the same time, it can also improve the dispersibility of pearl powder in the system, ensure the uniform distribution of pearl powder, and enhance the stability of the emulsion. After being treated with lauroyl lysine, pearl powder can provide a natural pearlescent effect for the product, enhance the covering power, make the skin tone look more even, and give the product a delicate luster and smooth touch.

[0029] Preferably, the pearl powder is also pre-treated, comprising the following steps: dispersing the pearl powder in a sodium hydroxide solution, stirring at a temperature of 40-45°C for 10-15 minutes, washing with water, and then dispersing in an acetic acid solution, adding polydimethylsiloxane and chitosan, ultrasonicating for 20-25 minutes, drying, and crushing to obtain pre-treated pearl powder.

[0030] By adopting the above technical solution, the pearl powder is treated with sodium hydroxide to remove organic impurities in the pearl powder, thereby increasing the specific surface area and bioavailability of the pearl powder, facilitating subsequent mixing with other components, and making the pearl powder more easily absorbed by the skin, thereby enhancing the effect of the skin care product.

[0031] Polydimethylsiloxane has good moisturizing and nourishing properties. It can form a breathable protective film to prevent skin moisture from evaporating and keep the skin soft and smooth. Polydimethylsiloxane can be loaded on the surface of pearl powder particles to improve the dispersibility of pearl powder in the system, ensure that pearl powder is evenly distributed, avoid agglomeration, and improve product stability and consistency.

[0032] Chitosan has good biocompatibility, biodegradability, antibacterial and anti-inflammatory effects, inhibits bacterial growth on the skin surface, promotes skin repair, enhances the skin's barrier function, and helps maintain the skin's health. Mixing with polydimethylsiloxane improves the biocompatibility of polydimethylsiloxane, allowing polydimethylsiloxane to adhere to the surface of pearl powder, subsequently improving the stability of pearl powder in the system, ensuring that the pearl powder is evenly distributed, and enhancing the stability of the product.

[0033] Preferably, the mass ratio of the pearl powder, polydimethylsiloxane and chitosan is 1:0.2-0.4:0.6-0.8.

[0034] By adopting the above technical solution, the mass ratio of pearl powder, polydimethylsiloxane and chitosan is further limited within a certain range, thereby improving the dispersibility and stability of pearl powder. Polydimethylsiloxane can be loaded on the surface of pearl powder particles to improve the dispersibility of pearl powder in the system, ensure the uniform distribution of pearl powder, avoid agglomeration, and improve the stability and consistency of the product.

[0035] Chitosan is mixed with polydimethylsiloxane to improve the biocompatibility of polydimethylsiloxane, so that polydimethylsiloxane adheres to the surface of pearl powder, and subsequently improves the stability of pearl powder in the system, ensures that pearl powder is evenly distributed, and enhances the stability of the product.

[0036] In summary, this application has the following beneficial effects: 1. In this application, the test sample is evenly applied, and the image is analyzed and processed by ImageJ to test the covering power. This test method can provide objective quantitative data, reduce the deviation of subjective judgment, and improve the accuracy and repeatability of the test results. Moreover, through image analysis, the covering power parameters of the skin color can be accurately measured, providing detailed quantitative indicators and improving the test efficiency.

[0037] 2. The method of using image processing technology to evaluate the effect of makeup in this application quantitatively evaluates the characteristics such as covering power and soft focus effect by analyzing the images of the skin before and after applying the test sample. The image analysis method can adapt to different testing needs and can be optimized for specific test targets by adjusting the algorithm parameters. Compared with some physical testing methods, the image analysis method is non-contact, will not cause physical damage to the skin, and is safer and more hygienic. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 The test results of the blank control group and the test sample transparent plate group are shown in Figure 1. Figure 1 (a) is a photo of the blank control group with a transparent plate placed on A4 paper with words. Figure 1 (b) is a photo of the test sample transparent plate set placed on A4 paper with words, Figure 1 (c) is the effect of the blank control group transparent plate placed on A4 paper with words and processed into a bright band by ImageJ. Figure 1 (d) is a picture of the transparent plate group of the test sample placed on A4 paper with words and processed into a bright band by ImageJ. DETAILED DESCRIPTION

[0039] Preparation example of cosmetic powder raw materials Preparation Example 1-1 The method for preparing cosmetic powder raw materials comprises the following steps: (1) 20 g of water and 10 g of mineral oil were mixed, 2 g of fatty acid ester was added, and the mixture was stirred at 65° C., first at a stirring rate of 5500 r / min for 12 min, and then at a stirring rate of 1000 r / min for 8 min to obtain a W / O emulsion; (2) Add lauroyl lysine and pearl powder to the W / O emulsion obtained in step (1), first homogenize, then ultrasonicate, to obtain a cosmetic powder raw material.

[0040] The homogenization conditions were 7000 rpm, 10 min; the ultrasonic conditions were 380 W / L, 8 min; and the high-pressure homogenization conditions were 110 MPa, 130 s.

[0041] The mass ratio of mineral oil, lauroyl lysine and pearl powder is 1:0.5:1.

[0042] Preparation Example 1-2 The difference from Preparation Example 1-1 is that lauroyl lysine is not added.

[0043] Preparation Example 1-3 The difference from Preparation Example 1-1 is that no mineral oil was added.

[0044] Preparation Example 1-4 The difference from Preparation Example 1-1 is that the mass ratio of mineral oil, lauroyl lysine and pearl powder is 1.5:0.7:1.

[0045] Preparation Example 1-5 The difference from Preparation Example 1-1 is that the mass ratio of mineral oil, lauroyl lysine and pearl powder is 2.5:0.1:1.

[0046] Preparation Example 1-6 The difference from Preparation Example 1-1 is that the pearl powder is further pretreated, including the following steps: dispersing 30 g of pearl powder in 40 mL of a 10% sodium hydroxide solution, stirring at 45° C. for 15 min, washing with water, and then dispersing in 50 mL of a 5% acetic acid solution, adding polydimethylsiloxane and chitosan, ultrasonicating for 25 min, drying, and crushing to obtain pretreated pearl powder.

[0047] The mass ratio of pearl powder, polydimethylsiloxane and chitosan is 1:0.2:0.6.

[0048] Preparation Example 1-7 The difference from Preparation Example 1-6 is that no polydimethylsiloxane is added.

[0049] Preparation Example 1-8 The difference from Preparation Example 1-6 is that chitosan is not added.

[0050] Preparation Example 1-9 The difference from Preparation Example 1-6 is that the mass ratio of pearl powder, polydimethylsiloxane and chitosan is 1:0.4:0.8.

[0051] Preparation Example 1-10 The difference from Preparation Example 1-6 is that the mass ratio of pearl powder, polydimethylsiloxane and chitosan is 1:0.7:0.1. Example

[0052] Example 1 A method for testing the soft focus and covering power of makeup, comprising the following steps: 1) Place the transparent plate on the platform (fix the transparent plate with a vacuum machine), weigh 2g of the test sample and place it on one end of the transparent plate for later use; the test sample is our company's liquid foundation; 2) Use a wire rod coater to slide the test sample at a constant speed to form a film with a thickness of 2 μm. Let it stand for 5 minutes and measure the transmittance and haze value with a haze meter. Each test sample is measured 3 times in parallel and the average value is recorded; 3) Print the text on A4 paper, place the transparent plate coated with the test sample on the A4 paper, take photos in a light box, and record the photos as the sample group, and the transparent plate as the blank control group; 4) The images were analyzed and processed by ImageJ, and the integrated optical density IntDen was calculated as the quantitative value. The blank group IntDen was recorded as D0, and the sample group was recorded as D1. Then, the covering power % = (D0-D1) / D0*100%.

[0053] Specifically, step 4) uses ImageJ, and the specific steps are as follows: (1) First, convert the image into a grayscale image Image → Type → 8-bit, select process → subtrackbackground, and adjust the parameters and settings in the pop-up window to correct the image background and eliminate the background effect of the image.

[0054] (2) Set quantitative parameters: Analyze → Set Measurements. In the pop-up dialog box, check Area, Mean gray value, Min & max gray value, and Integrated density.

[0055] (3) Set the unit: Analyze → Set Scale. In the dialog box that pops up, fill in "pixels" after "Unit of length". Leave the rest unchanged.

[0056] (4) Convert the captured image into a bright band: Edit → Invert. (5) Click on the measurement button in the drop-down menu of Analyze to pop up the grayscale statistics of the area you selected. The integrated optical density IntDen is used as the quantitative value for calculation. The blank group IntDen is recorded as D0, and the sample group is recorded as D1. Then the hiding power % = (D0-D1) / D0*100%.

[0057] Example 2 A method for testing the soft focus and covering power of makeup, which differs from Example 1 in that it comprises the following steps: 1) Place the transparent plate on the platform (fix the transparent plate with a vacuum machine), weigh 4g of the test sample and place it at one end of the transparent plate for later use; 2) Use a wire rod coater to slide the test sample at a constant speed to form a film with a thickness of 3 μm. Let it stand for 6 minutes, and use a haze meter to measure the transmittance and haze value. Each test sample is measured 4 times in parallel and the average value is recorded; 3) Print the text on A4 paper, place the transparent plate coated with the test sample on the A4 paper, take photos in a light box, and record the photos as the sample group, and the transparent plate as the blank control group; 4) The images were analyzed and processed by ImageJ, and the integrated optical density IntDen was calculated as the quantitative value. The blank group IntDen was recorded as D0, and the sample group was recorded as D1. Then, the covering power % = (D0-D1) / D0*100%.

[0058] Example 3 A method for testing the soft focus and covering power of color makeup, which differs from Example 1 in that the test samples use cosmetic powder raw materials, namely W / O emulsion and pearl powder treated with lauroyl lysine, and the cosmetic powder raw materials replace the liquid foundation.

[0059] The cosmetic powder raw material adopts Preparation Example 1-1.

[0060] Example 4 A method for testing the soft focus and covering power of makeup, which differs from Example 3 in that the cosmetic powder raw material adopts Preparation Example 1-2.

[0061] Example 5 A method for testing the soft focus and covering power of makeup, which differs from Example 3 in that the cosmetic powder raw material adopts Preparation Example 1-3.

[0062] Example 6 A method for testing the soft focus and covering power of color makeup, which differs from Example 3 in that the cosmetic powder raw material adopts Preparation Examples 1-4.

[0063] Example 7 A method for testing the soft focus and covering power of color makeup, which differs from Example 3 in that the cosmetic powder raw material adopts Preparation Example 1-5.

[0064] Example 8 A method for testing the soft focus and covering power of color makeup, which differs from Example 3 in that the cosmetic powder raw materials are prepared as in Preparation Examples 1-6.

[0065] Example 9 A method for testing the soft focus and covering power of color makeup, which is different from Example 6 and Example 3 in that the cosmetic powder raw material adopts Preparation Examples 1-7.

[0066] Example 10 A method for testing the soft focus and covering power of color makeup, which is different from Example 6 and Example 3 in that the cosmetic powder raw material adopts Preparation Examples 1-8.

[0067] Embodiment 11 A method for testing the soft focus and covering power of color makeup, which is different from Example 6 and Example 3 in that the cosmetic powder raw material adopts Preparation Examples 1-9.

[0068] Example 12 A method for testing the soft focus and covering power of color makeup, which is different from Example 6 and Example 3 in that the cosmetic powder raw material adopts Preparation Examples 1-10.

[0069] Performance testing The transparency, haze and hiding power values ​​of Examples 1-12 were tested according to the method for testing the soft focus and hiding power of color cosmetics; the test results are shown in Table 1.

[0070] Table 1 Test data of embodiments and comparative examples Combining the examples and the data in the table, it can be seen that the foundation liquid tested by the method for testing the soft focus and hiding power of makeup in Examples 1-2 has good stability, hiding power and haze. By comparing Example 1 with the blank control group, it is found that Figure 1 As shown, Figure 1 (a) is a photo of the blank control group with a transparent plate placed on A4 paper with words. Figure 1 (b) is a photo of the effect of placing the test sample transparent plate group on A4 paper with words. It can be seen that the test sample transparent plate group has high haze, high hiding power, and low transparency. Figure 1 (c) is the effect of the blank control group transparent plate placed on A4 paper with words and processed into a bright band by ImageJ. Figure 1 (d) is the effect picture of the transparent plate group of the test sample placed on A4 paper with words and processed into a bright band by ImageJ. It can be seen that the letters on the transparent plate group of the test sample are not clear, while the letters on the blank control group are clearer, indicating that the transparent plate group of the test sample has high haze, high hiding power and low transmittance.

[0071] As can be seen from Table 1, the transmittance of Example 1 is 89%, the haze is 73.5%, and the hiding power is 66.6%, while the transmittance of the blank control group is 91.6%, the haze is 0.93%, and the hiding power is 0, indicating that the higher the transmittance, the higher the light transmittance of the sample, and the relatively weaker the hiding power; the higher the haze value, the higher the hiding power, but the lower the light transmittance, the heavier the makeup feeling, and the raw materials or products with high transmittance and high haze have a better soft focus effect, so that the light can reach the skin and illuminate the skin color, while the light has a scattered transmission, and less light reaches the blemishes, which has a weakening effect on skin blemishes. In addition, the hiding power can accurately reflect the concealing effect of the product or raw material. The three parameters of transmittance, haze, and hiding power can quantitatively reflect the makeup effect of the raw material or product in concealing blemishes.

[0072] Example 3 Test cosmetic powder raw materials, the cosmetic powder raw materials are W / O (oil in water) emulsion and pearl powder treated with lauroyl lysine. As shown in Table 1, the transparency is 75%, the haze is 89.9%, and the hiding power is 83.7%, indicating that the treated pearl powder has good hiding power, dispersibility and adhesion, making it smoother and more natural on the skin, while providing a certain hiding power and durability.

[0073] In Example 4, lauroyl lysine is not added in the preparation method of the cosmetic powder raw material. In Example 5, mineral oil is not added in the preparation method of the cosmetic powder raw material. In Examples 6-7, the mass ratio of mineral oil, lauroyl lysine and pearl powder is changed. As can be seen from Table 1, the transparency of Examples 4-5 is greater than that of Example 3, but the haze and hiding power are less than that of Example 3, indicating that the pearl powder treated with lauroyl lysine improves the dispersibility and stability of the pearl powder. The pearl powder treated with lauroyl lysine has better skin affinity and glossiness, and at the same time enhances the hiding power and skin feel of the product; and adding W / O emulsion to the pearl powder can improve the dispersibility and adhesion of the pearl powder. The W / O emulsion is mainly used to provide moisturizing and hydrating effects. In the emulsion structure, the water phase is wrapped by the oil phase to form a stable emulsified system.

[0074] The transparency of Example 7 is greater than that of Example 3 and Example 6, but less than that of Example 3-4, while the haze and hiding power are less than those of Example 3 and Example 6, but greater than that of Example 3-4, indicating that the combination of mineral oil, lauroyl lysine and pearl powder has a synergistic effect, improves the dispersibility of pearl powder in the system, ensures the uniform distribution of pearl powder, enhances the stability and hiding power of the emulsion, makes the skin color look more uniform, and gives the product a delicate luster and smooth touch.

[0075] Example 8 pre-treated the pearl powder. As shown in Table 1, the transmittance was 68%, the haze was 96.7%, and the hiding power was 91.2%, indicating that polydimethylsiloxane can be loaded on the surface of the pearl powder particles, improve the dispersibility of the pearl powder in the system, ensure the uniform distribution of the pearl powder, avoid agglomeration, and improve the stability and consistency of the product. Chitosan is mixed with polydimethylsiloxane to improve the biocompatibility of polydimethylsiloxane, so that polydimethylsiloxane adheres to the surface of the pearl powder, and subsequently improves the stability of the pearl powder in the system, ensures the uniform distribution of the pearl powder, and enhances the stability of the product.

[0076] In Example 9, polydimethylsiloxane was not added during the pretreatment of pearl powder, and in Example 10, chitosan was not added during the pretreatment of pearl powder. In Examples 11-12, the mass ratio of pearl powder, polydimethylsiloxane and chitosan was changed. As shown in Table 1, the transparency of Examples 9-10 was greater than that of Example 8 and less than that of Example 3, while the haze and hiding power were less than that of Example 8 and greater than that of Example 3, indicating that polydimethylsiloxane has good moisturizing and nourishing properties, can be loaded on the surface of pearl powder particles, improve the dispersibility of pearl powder in the system, and improve the stability and consistency of the product. Chitosan has good biocompatibility, biodegradability, antibacterial and anti-inflammatory effects, and is mixed with pearl powder to improve the stability of pearl powder in the system, ensure the uniform distribution of pearl powder, and enhance the stability of the product.

[0077] The transmittance of Example 12 is less than that of Examples 9-10, and greater than that of Example 8, while the haze and hiding power are greater than those of Examples 9-10, and less than that of Example 8, indicating that the mixing of polydimethylsiloxane, chitosan and polydimethylsiloxane improves the biocompatibility of polydimethylsiloxane, allowing polydimethylsiloxane to adhere to the surface of pearl powder, subsequently improving the stability of pearl powder in the system, ensuring uniform distribution of pearl powder, and enhancing the stability of the product.

[0078] 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 modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A method for testing the soft focus and coverage of makeup. It is characterized in that The following steps are involved: 1) Place the transparent plate on the platform, weigh 2-4g of the test sample and place it on one end of the transparent plate for later use; 2) Spread the test sample evenly to form a film with a thickness of 2-3μm, let it stand for 5-6 minutes, and measure the transmittance and haze value. Each test sample is measured 3-4 times in parallel and the average value is recorded; 3) Print words on paper, place the transparent plate coated with the test sample on the paper, take photos in a light box, and record the photos as the sample group, and the transparent plate as the blank control group; 4) Analyze and process the images using ImageJ, and calculate the integrated optical density IntDen as the quantitative value. The blank group IntDen is recorded as D 0 , the sample group is denoted as D 1 , then hiding power% = (D 0 -D 1 ) / D 0 *100%.

2. A method for testing the soft focus and covering power of makeup according to claim 1, It is characterized in that In step 2), use a wire rod applicator to slide evenly on the test sample at a constant speed to evenly apply the test sample.

3. A method for testing the soft focus and covering power of makeup according to claim 1, It is characterized in that In step 2), a haze meter is used to measure the transmittance and haze value of the test sample.

4. A method for testing the soft focus and covering power of makeup according to claim 1, It is characterized in that The test sample includes one of cosmetic powder raw materials, liquid foundation, loose powder, and pressed powder.

5. A method for testing the soft focus and covering power of makeup according to claim 4, It is characterized in that The cosmetic powder raw materials include W / O emulsion and powder treated with lauroyl lysine, and the powder includes pearl powder, mica, talc, silica, iron oxide and titanium dioxide.

6. A method for testing the soft focus and covering power of makeup according to claim 5, It is characterized in that The method for preparing the cosmetic powder raw material comprises the following steps: (1) Mix water and mineral oil, add fatty acid ester, stir evenly at a temperature of 60-65°C, first stir at a stirring rate of 5000-5500 r / min for 10-12 min, and then stir at a stirring rate of 1000-1500 r / min for 5-8 min to obtain a W / O emulsion; (2) Add lauroyl lysine and powder to the W / O emulsion obtained in step (1), first homogenize, then perform ultrasonic treatment, to obtain a cosmetic powder raw material, wherein the powder is pearl powder.

7. A method for testing the soft focus and covering power of makeup according to claim 6, It is characterized in that The homogenization conditions are 7000-7500 rpm, 5-10 min; the ultrasonic conditions are 350-380 W / L, 6-8 min; and the high-pressure homogenization conditions are 100-110 MPa, 120-130 s.

8. A method for testing the soft focus and covering power of makeup according to claim 6, It is characterized in that The mass ratio of the mineral oil, lauroyl lysine and pearl powder is 1-1.5:0.5-0.7:

1.

9. A method for testing the soft focus and covering power of makeup according to claim 6, It is characterized in that The pearl powder is also pre-treated, including the following steps: dispersing the pearl powder in a sodium hydroxide solution, stirring at a temperature of 40-45°C for 10-15 minutes, washing with water, and then dispersing in an acetic acid solution, adding polydimethylsiloxane and chitosan, ultrasonicating for 20-25 minutes, drying, and crushing to obtain pre-treated pearl powder.

10. A method for testing the soft focus and covering power of makeup according to claim 9, It is characterized in that The mass ratio of the pearl powder, polydimethylsiloxane and chitosan is 1:0.2-0.4:0.6-0.8.

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