Preparation method of powder cosmetics with gradient color effect and powder cosmetics

Abstract

The present application provides a preparation method and powder cosmetics with a gradient color effect. The preparation method includes: mixing materials; coloring: providing a mold, the mold having at least one upwardly open cavity; taking at least one water-soluble pigment, diluting it separately to obtain at least one pigment solution, and applying the at least one pigment solution to at least one preset position at the bottom of the cavity; filling; freezing: freezing the material body in the mold at a low temperature to obtain a powder master product; demolding: separating the powder master product from the mold; drying: drying the demolded powder master product to obtain a powder cosmetic with a gradient color effect; the mass percentage concentration of the pigment solution is 0.1% to 10%; the viscosity of the mixed material at 25°C is 1000 to 15000 cP. The powder cosmetics prepared by the preparation method of the present application can achieve natural blending and gradient color effects.

Description

Technical Field

[0001] The present application belongs to the technical field of daily cosmetics, and specifically relates to a preparation method of powder cosmetics with a gradient color effect and the powder cosmetics. Background Art

[0002] Powder cosmetics can modify facial features and increase the luster of makeup. For example, highlighter powder can brighten local areas, enhance facial contours, make the base makeup more radiant, say goodbye to dullness, and create a visual contrast between light and shadow, thereby increasing the three-dimensional sense of facial features.

[0003] The mixed color powder cosmetics currently on the market are mostly pressed powders, which have complex production processes, low production efficiency, and irregular surface colors or obvious splicing effects. Summary of the Invention

[0004] In view of this, the present application provides a method for preparing a powder cosmetic with a gradient color effect and a powder cosmetic with a natural gradient blending effect.

[0005] In a first aspect, an embodiment of the present application provides a method for preparing a powder cosmetic with a gradient color effect, comprising the following steps: mixing: providing raw materials for preparing powder cosmetics, mixing to obtain a mixed material body; coloring: providing a mold, the mold having at least one upwardly open cavity; taking at least one water-soluble pigment, diluting them separately to obtain at least one pigment solution, and applying the at least one pigment solution to at least one preset position at the bottom of the cavity; filling: filling the mixed material body into the mold after coloring according to a preset amount, and the water-soluble pigment diffuses directionally in the mixed material body under the action of the concentration gradient; freezing: freezing the material body in the mold at low temperature to obtain a powder master product; demolding: separating the powder master product from the mold; drying: drying the demolded powder master product to obtain a powder cosmetic with a gradient color effect; the mass percentage concentration of the pigment solution is 0.1% to 10%, preferably 0.5 to 5%; the viscosity of the mixed material body at 25°C is 1000 to 15000 cP, preferably 2000 to 5000 cP.

[0006] According to an embodiment of the first aspect of the present application, the mold is made of TPR, TPE, silicone, silicone rubber, rubber or metal; the bottom of the cavity of the mold has or does not have a three-dimensional pattern.

[0007] According to an embodiment of the first aspect of the present application, the gradient color effect is formed on the contact surface between the powder cosmetics and the bottom of the chamber, and extends toward the interior of the powder cosmetics.

[0008] According to an embodiment of the first aspect of the present application, in the filling step, the mixed material body is filled into the mold from different directions to achieve control of the diffusion direction of the water-soluble pigment.

[0009] According to an embodiment of the first aspect of the present application, after the filling step, an assisted diffusion step is also included, and the assisted diffusion step includes: baking or microwave heating the mixed material body in the mold.

[0010] According to an embodiment of the first aspect of the present application, the baking temperature is 30 to 70°C, and the baking time is 5 minutes to 1 hour; preferably, during the baking, the baking temperature increases gradually from the edge area to the center area of the mixture body; more preferably, the baking temperature of the edge area of the mixture body is 30 to 40°C, and the baking temperature of the center area of the mixture body is 60 to 70°C.

[0011] According to an embodiment of the first aspect of the present application, the power of the microwave heating is 0.2 to 1 GHz, preferably 0.3 to 0.5 GHz; the microwave heating time is 20 s to 5 min, preferably 2 to 3 min.

[0012] According to an embodiment of the first aspect of the present application, the step of freezing the material in the mold at low temperature is carried out in a liquid nitrogen quick-freezing device; preferably, the temperature inside the liquid nitrogen quick-freezing device is -120 to -70°C, preferably -95 to -80°C.

[0013] According to an embodiment of the first aspect of the present application, the liquid nitrogen quick-freezing device is a liquid nitrogen tunnel, and the material body passes through the liquid nitrogen tunnel on a conveyor belt in the liquid nitrogen tunnel at a speed of 0.6 to 1 meter per minute, and the powdered mother product passes through the liquid nitrogen tunnel for 6 to 10 minutes.

[0014] According to an embodiment of the first aspect of the present application, drying includes any combination of one or more of vacuum drying, freeze drying, microwave drying and supercritical fluid drying; preferably, drying is vacuum freeze drying.

[0015] According to an embodiment of the first aspect of the present application, the raw materials for preparing powder cosmetics include a powder phase component, an oil phase component, and a water phase component, and the raw materials form an oil-in-water emulsion system, wherein:

[0016] The powder phase components include: one or more of fillers and colorants;

[0017] The oil phase components include: one or more of: emollients, antioxidants, and sunscreens;

[0018] The aqueous phase components include: one or more of solvents, thickeners, film formers, moisturizers, emulsifiers, preservatives, and active ingredients.

[0019] In a second aspect, an embodiment of the present application provides a powder cosmetic with a gradient color effect, characterized in that it is prepared by any of the above methods; optionally, the powder cosmetic is selected from pressed powder, blush, eye shadow or highlighter powder.

[0020] Compared with the prior art, this application has at least the following beneficial effects:

[0021] In the method provided in the present application, water is used as a solvent, and water-soluble pigments are dissolved into it to form a pigment solution with good fluidity. The pigment solution is first applied to the bottom of the mold cavity, and then the material is filled. Under the action of the concentration gradient, the pigment naturally diffuses from the high-concentration area to the low-concentration area, forming a soft transition gradient color effect; when two or more water-soluble pigments are used, pigments of different colors naturally fuse during the diffusion process, forming multi-color blending and gradient. By adjusting the initial concentration of the pigment solution and the viscosity of the mixed material, the prepared powder cosmetics have a natural gradient blending effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Other features, objects and advantages of the present application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings, in which the same or similar reference numerals represent the same or similar features.

[0023] Figure 1 This is a product schematic diagram of Example 15 provided in the Examples of this application;

[0024] Figure 2 This is a product schematic diagram of Example 16 provided in the examples of this application. DETAILED DESCRIPTION

[0025] In order to make the application purpose, technical solution and beneficial technical effects of this application clearer, the application is further described in detail below with reference to the embodiments. It should be understood that the embodiments described in this specification are only for explaining this application and are not intended to limit this application.

[0026] For simplicity, this application only explicitly discloses certain numerical ranges. However, any lower limit may be combined with any upper limit to form an unspecified range; and any lower limit may be combined with other lower limits to form an unspecified range, and similarly, any upper limit may be combined with any other upper limit to form an unspecified range. In addition, although not explicitly stated, each point or individual value between the endpoints of a range is included in the range. Thus, each point or individual value may serve as its own lower limit or upper limit and be combined with any other point or individual value, or with other lower limits or upper limits, to form an unspecified range.

[0027] In the description of this application, it should be noted that, unless otherwise specified, “above” and “below” are inclusive of the number, and “a variety” in “one or more” means two or more.

[0028] The above disclosure of the present application is not intended to describe every disclosed embodiment or every implementation in the present application. The following description more specifically illustrates exemplary embodiments. In many places throughout the application, guidance is provided through a series of examples, which can be used in various combinations. In each example, the enumeration is intended only as a representative group and should not be construed as exhaustive.

[0029] Currently, most mixed-color and gradient powder cosmetics on the market are pressed powders, which have complex production processes, low production efficiency, and cannot form a natural gradient effect on the surface.

[0030] In view of the above problems, the present application provides a method for preparing powder cosmetics with a gradient color effect and powder cosmetics with a gradient color effect, which have a natural gradient blending effect, can be mass-produced, and improve production efficiency.

[0031] Preparation of powder cosmetics with gradient color effect

[0032] In a first aspect, an embodiment of the present application provides a method for preparing a powder cosmetic with a gradient color effect, comprising the following steps: mixing: providing raw materials for preparing powder cosmetics, mixing to obtain a mixed material body; coloring: providing a mold, the mold having at least one upwardly open cavity; taking at least one water-soluble pigment, diluting them separately to obtain at least one pigment solution, and applying the at least one pigment solution to at least one preset position at the bottom of the cavity; filling: filling the mixed material body into the mold after coloring according to a preset amount, and the water-soluble pigment diffuses directionally in the mixed material body under the action of the concentration gradient; freezing: freezing the material body in the mold at low temperature to obtain a powder master product; demolding: separating the powder master product from the mold; drying: drying the demolded powder master product to obtain a powder cosmetic with a gradient color effect; the mass percentage concentration of the pigment solution is 0.1% to 10%, preferably 0.5 to 5%; the viscosity of the mixed material body at 25°C is 1000 to 15000 cP, preferably 2000 to 5000 cP.

[0033] In the mixing step, the raw materials for preparing the powder cosmetics with a gradient color effect can be purchased commercially or homemade. It is understood that the raw materials for preparing the powder cosmetics with a gradient color effect generally include a powder phase component, an oil phase component, and an aqueous phase component. The raw materials can be mixed in steps using various methods commonly used in the prior art, such as mechanical stirring, and homogenization and defoaming operations can be added during the mixing process. Different mixing methods and steps can be used depending on the raw materials, and the present application is not limited thereto.

[0034] The preparation method provided in the embodiments of the present application involves pre-dotting a pigment on a mold. This method requires providing a mold and preparing a water-soluble pigment solution. The mold must have at least one upwardly open chamber for accommodating the pigment to be dotted and the mixed material. When preparing the water-soluble pigment solution, one or more water-soluble pigments are dissolved and diluted to obtain one or more pigment solutions, which are then dotted onto at least one predetermined location at the bottom of the chamber.

[0035] In the embodiment of the present application, when preparing the pigment solution, the same pigment can be selected and diluted into solutions of multiple concentrations to form a concentration gradient; two or more pigments can be selected and diluted into solutions of different concentrations or multiple concentrations to form a concentration gradient; two or more pigments can also be mixed to obtain a pigment of a new color, which is then diluted and applied. There is no limitation on the use of various soluble pigments in the prior art, and they can be selected according to the requirements of the gradient color effect.

[0036] The embodiments of the present application do not limit the specific color of the water-soluble pigment. For example, the water-soluble pigment can be a commercially available water-soluble pigment product with the following brands: Red 4 (CI 14700), Red 22 (CI 45380), Red 28 (CI 45410), Red 33 (CI17200), Red 40 (CI 16035), Carmine (CI 75470), Blue 1 (CI 42090), Yellow 5 (CI 19140), Yellow 6 (CI15985), Yellow 7 (CI 10316), Yellow 8 (CI 45350), Yellow 10 (CI 47005), Violet 2 (CI 60730), Orange 4 (CI15510), Green 3 (CI 42053), Green 5 (CI 61570), Green 8 (CI 59040) and the like, or a combination of several thereof.

[0037] In the embodiment of the present application, the specific location and number of the preset positions are not limited and can be selected according to the design. For example, the preset positions are evenly distributed in an outer ring around the bottom of the chamber, or evenly distributed on a certain side of the bottom of the chamber, or at a fixed point at the bottom of the chamber.

[0038] During the filling step, the preset amount can be set based on the volume of the powdered cosmetic, the mold capacity, or the filling requirements. The preset amount can be the same or different for each filling. After the mixture is filled into the color-coated mold according to the preset amount, the water-soluble pigment will diffuse directionally within the mixture due to the concentration gradient.

[0039] In the embodiments of the present application, the filling can be performed using a conventional filling machine or with the aid of a pneumatic feeding device. The pneumatic feeding device refers to a device that fills the material into the mold by pneumatic conveying. For example, the pneumatic feeding device may include an air pump and a pipe connected to the air pump, the air pump is used to provide the air pressure required for conveying, and the pipe is used to fill the material into the mold, but the present application is not limited thereto. When using a conventional filling machine, the material is filled under the action of gravity. When the fluidity of the material meets the requirements, the filling can be carried out at room temperature. When it is desired to improve the fluidity of the material, the material can be appropriately heated.

[0040] For powder cosmetics with gradient color effects that create fine relief, a pneumatic feeder is a more optimal method. The pneumatic feeder fills the mold with a preset amount of material. The pressure helps the material reach the sharp corners of the fine relief. Even with high viscosity, the material can still be effectively filled into these sharp corners and achieve a high density, eliminating the problems of porosity and looseness in the finished product.

[0041] Specifically, the mixed material can be pressed into the mold by air pressure. For example, a pneumatic feeding device includes a feed pipe, an air pump, and a discharge pipe. The air pump provides conveying air pressure to draw the material from the feed pipe into the pneumatic feeding device and then press it into the mold through the discharge pipe. The material can also be drawn into the mold by air pressure. For example, a pneumatic feeding device is connected to the mold, and the pneumatic feeding device provides conveying air pressure to draw the material into the mold. In some embodiments, the pressure in the pneumatic feeding device is 0.01 to 0.06 MPa, or 0.02 to 0.04 MPa.

[0042] After the filling step, a solvent removal step is also required. Through freeze-drying and other process steps, the solvent is removed from the powder cosmetics. The solvent content in the final powder cosmetics generally needs to be controlled below 5%.

[0043] In the method provided in the present application, water is used as a solvent, and water-soluble pigments are dissolved into it to form a pigment solution with good fluidity. The pigment solution is first applied to the bottom of the mold cavity, and then the material is filled. Under the action of the concentration gradient, the pigment naturally diffuses from the high-concentration area to the low-concentration area, forming a soft transition gradient color effect; when two or more water-soluble pigments are used, pigments of different colors naturally merge during the diffusion process, forming multi-color shading and gradient.

[0044] The present application utilizes the diffusion of water-soluble pigments in the material body to achieve natural blending and gradient color effects, and the initial concentration of the pigment solution and the viscosity of the mixed material body are key parameters. On the one hand, the mixed material body needs to have an appropriate viscosity suitable for the diffusion of water-soluble pigments. If the viscosity is too large, the diffusion of the pigment is hindered, and the gradient rendering effect is not obvious; if the viscosity is too small, the pigment diffuses transitionally in the material body, and a natural gradient blending effect cannot be formed. On the other hand, the pigment solution needs to have an initial concentration suitable for diffusion in the mixed material body. If the initial concentration of the pigment solution is too low, the diffusion effect is not obvious and the blending effect cannot be achieved; if the initial concentration of the pigment solution is too high, pigment accumulation occurs locally in the material body, and the surface is uneven after drying.

[0045] In the embodiment of the present application, by controlling the initial concentration of the pigment solution and the viscosity of the mixture within a certain range, the prepared powder cosmetics have a natural gradient blooming effect. The embodiment of the present application is suitable for preparing water-in-oil system powder cosmetics.

[0046] Illustratively, the viscosity of the mixture at 25° C. is 1000 cP, 2000 cP, 3000 cP, 4000 cP, 5000 cP, 6000 cP, 7000 cP, 8000 cP, 9000 cP, 10000 cP, 11000 cP, 12000 cP, 13000 cP, 14000 cP, 15000 cP or an interval range consisting of any two of the above values.

[0047] Exemplarily, the mass percentage concentration of the pigment solution is 0.1%, 0.2%, 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 7%, 8%, 9%, 10% or an interval range consisting of any two of the above values.

[0048] The preparation method provided in the embodiment of the present application has a simple manufacturing process, gets rid of the complexity of the traditional color mixing and powder pressing process, can realize batch production, and improve production efficiency.

[0049] In some embodiments, the mold is made of TPR, TPE, silicone, silicone rubber, rubber or metal; the bottom of the cavity of the mold has or does not have a three-dimensional pattern.

[0050] The preparation method in the embodiment of the present application can use the mold made of the above-mentioned TPR, TPE, silicone, silicone rubber, rubber or metal, and can prepare powder cosmetics with a natural gradient color effect.

[0051] The bottom of the cavity of the selected mold can be flat and not have a three-dimensional pattern; or the bottom of the cavity of the mold can have a three-dimensional pattern, where the three-dimensional pattern can be diverse. For example, the three-dimensional pattern is a deer shape or a wavy shape. The embodiments of the present application are not limited to this.

[0052] In some embodiments, the gradient color effect is formed on the contact surface between the powder cosmetics and the bottom of the chamber, and extends toward the interior of the powder cosmetics.

[0053] The pigment solution is dotted on the bottom of the chamber, and a gradient color effect is formed at the contact surface between the powder cosmetics and the bottom of the chamber. Under the action of the concentration gradient, the pigment solution diffuses in the thickness direction of the powder cosmetics, and the gradient color effect extends from the contact surface with the bottom of the chamber to the direction away from the contact surface, that is, extending into the interior of the powder cosmetics.

[0054] In some embodiments, during the filling step, the mixed material body is filled into the mold from different directions to achieve control of the diffusion direction of the water-soluble pigment.

[0055] The mixture has an impact when filling, which will drive the diffusion of the water-soluble pigment, thereby controlling the diffusion direction of the water-soluble pigment. When the mixture is filled into the mold from different directions, the water-soluble pigment will diffuse in different directions, which is conducive to forming a natural gradient effect.

[0056] In the embodiment of the present application, when filling the mixture body, the mixture body is filled into the mold from different directions. For example, the mixture body is filled along different directions at preset angles to the plane where the bottom of the mold is located. Preferably, the preset angle is 30° to 90°. Exemplarily, the preset angle is 30°, 40°, 45°, 50°, 60°, 70°, 80°, 90° or an interval range consisting of any two of the above values.

[0057] For example, when the preset angle is 90°, the mixture body is filled in a direction perpendicular to the plane where the bottom of the mold is located; when the preset angle is 60°, the mixture body is filled in a direction inclined to the plane where the bottom of the mold is located.

[0058] In some embodiments, after the filling step, an assisted diffusion step is further included, and the assisted diffusion step may include baking the mixed material body in the mold or heating the mixed material body in the mold with microwaves.

[0059] The embodiment of the present application adds an auxiliary diffusion step including baking or microwave heating after the filling step. On the one hand, baking or microwave heating can remove part of the moisture in the mixture body. On the other hand, baking or microwave heating can also promote the formation of a gradient color effect. After the filling is completed, the mixture body is in a steady state. During the baking or microwave heating process, the temperature of the mixture body rises, which helps the water-soluble pigment to continue to diffuse in the steady-state mixture body, making the gradient effect more natural; at the same time, the water-soluble pigment is also better adsorbed on the surface of the powder in the mixture body, making the gradient color effect more stable. By adding an auxiliary diffusion step after the filling step, the embodiment of the present application can promote a more natural gradient effect.

[0060] The baking temperature and baking time are not limited in the present embodiment and can be set as needed. Preferably, the baking temperature is 30-70° C. and the baking time is 5 min-1 h.

[0061] The baking temperature is in the range of 30 to 70°C, which makes the baking process milder, allows water to evaporate slowly, helps to improve the uniformity of powder cosmetics, and also allows water-soluble pigments to diffuse evenly in the steady-state mixture. Exemplarily, the baking temperature is 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C or an interval consisting of any two of the above values.

[0062] The baking time is within the range of 5 minutes to 1 hour. This can prevent excessive evaporation of some of the moisture in the mixed material and improve baking efficiency, saving production time. For example, the baking time is 5 minutes, 10 minutes, 15 minutes, 20 minutes, 30 minutes, 40 minutes, 50 minutes, 1 hour, or a range consisting of any two of the above values.

[0063] Furthermore, in the present application, during the directional diffusion of water-soluble pigments in the mixed material under the action of concentration gradient, the diffusion rate of pigment molecules in the edge area of the material may be faster than that in the central area. The reason for this may be that the probability of pigment molecules in the edge area of the material colliding with each other is small, and the diffusion rate is fast, while the probability of pigment molecules in the central area of the material colliding with each other is large, and the diffusion rate is slow.

[0064] In some embodiments, baking is used to assist diffusion, with the baking temperature increasing gradually from the edge to the center of the mixture. For example, the baking temperature at the edge of the mixture is 30-40°C, while the baking temperature at the center is 60-70°C. This ensures that the assisted diffusion effect on the center is greater than that on the pigment molecules at the edge, thereby reducing the difference in diffusion speed between the edge and center regions when the pigment molecules diffuse within the mixture.

[0065] In other embodiments, microwave heating is used to assist diffusion. For example, the power of microwave heating is 0.2 to 1 GHz, preferably 0.3 to 0.5 GHz, and the microwave heating time is 20 s to 5 min, preferably 2 to 3 minutes. For example, the power of microwave heating can be 0.2 GHz, 0.3 GHz, 0.4 GHz, 0.5 GHz, 0.6 GHz, 0.7 GHz, 0.8 GHz, 0.9 GHz, 1.0 GHz, or an interval range consisting of any two of the above values. For example, the time of microwave heating can be 20 s, 30 s, 40 s, 50 s, 1 min, 1.2 min, 1.4 min, 1.5 min, 1.6 min, 1.8 min, 2 min, 2.5 min, 3 min, 3.5 min, 4 min, 4.5 min, 5 min, or an interval range consisting of any two of the above values.

[0066] Microwave heating has a central effect, that is, microwaves are reflected in the furnace cavity, and the center position is in the overlapping area of the microwave field. The microwave energy density is high, and the microwave energy decreases towards the edge area. Therefore, the present application uses relatively small power microwave heating to make the central area of the mixed material body first receive microwave radiation without drying immediately, causing the molecular motion to accelerate, and the auxiliary effect on diffusion is higher than that of the edge area. Due to the above-mentioned characteristics of microwave heating, not only can assisted diffusion be achieved in a relatively short time, but also the situation in which the diffusion speed of the edge area is greater than the diffusion speed of the central area when the pigment molecules diffuse in the material body is solved, the interference factors of the gradient color effect are minimized, and the gradient is more natural and soft.

[0067] In some embodiments, the step of freezing the material in the mold at low temperature is performed in a liquid nitrogen quick-freezing device; preferably, the temperature inside the liquid nitrogen quick-freezing device is -120 to -70°C, preferably -95 to -80°C.

[0068] Illustratively, the liquid nitrogen quick-freezing device may be a liquid nitrogen tunnel, a liquid nitrogen freezer, an ultra-low temperature refrigerator, etc. These devices are commercially available, and the present application is not limited thereto.

[0069] The raw material components in the mixture body undergo molecular quick freezing in an extremely low temperature environment in a liquid nitrogen quick freezing device. The mixture body contains components such as oils and emulsions. During its freezing and shaping process, it will experience a maximum ice crystal formation zone, which is approximately in the temperature range of -10 to 0°C. About 80% of the liquid (water, emulsion, etc.) will turn into ice. Unlike the ordinary freezing performed before demolding in the prior art, the powdered mother product quickly passes through the maximum ice crystal formation zone during the molecular quick freezing process completed in the liquid nitrogen tunnel in this application. The distribution of ice crystals in the powdered mother product is smaller, more uniform and dense. In the subsequent drying process, the removal of small and uniform ice crystals will not affect the gradient color effect that has been formed, ensuring a natural, soft and continuous gradient, and making the skin feel of the freeze-dried product softer, the product size variable is smaller and easier to control, the product structure is more stable, and the drop resistance is better.

[0070] In some embodiments, the liquid nitrogen quick-freezing device is a liquid nitrogen tunnel, and the material body passes through the liquid nitrogen tunnel on a conveyor belt in the liquid nitrogen tunnel at a speed of 0.6 to 1 m / min, and the powdered mother product passes through the liquid nitrogen tunnel for 6 to 10 minutes.

[0071] Liquid nitrogen tunnel, also known as liquid nitrogen tunnel quick freezer, is a device that uses liquid nitrogen as a cold source and adopts a continuous production method. It sends materials into the quick freezing tunnel through a conveyor belt to achieve continuous entry and exit of materials and rapid freezing.

[0072] This application also proposes optimal liquid nitrogen quick-freezing parameters for the preparation of powder cosmetics suitable for this application, based on research into the freezing curve of powder cosmetic mixtures and the energy transfer characteristics within a liquid nitrogen quick-freezing device. Under these parameters, liquid nitrogen quick-freezing of the powdered product ensures that the resulting powdered cosmetic has a uniform, dense texture, optimal skin feel, and optimal product structural stability and drop resistance. The powdered product is conveyed through the liquid nitrogen tunnel on a conveyor belt at a speed of 0.6 to 1 meter per minute, with the powdered product remaining in the tunnel for 6 to 10 minutes.

[0073] In some embodiments, drying comprises one or any combination of vacuum drying, freeze drying, microwave drying, and supercritical fluid drying; preferably, drying is vacuum freeze drying.

[0074] In the embodiment of the present application, the powdered masterbatch after demolding is dried by vacuum freeze-drying technology. Freeze-drying is to freeze the water-containing material below the freezing point to convert the water into ice. In a vacuum environment or under higher vacuum conditions, the small and evenly distributed ice crystals in the powdered masterbatch are sublimated into water vapor and removed, thereby retaining the composition, color and aroma of the raw materials to the greatest extent. The pigment is naturally adsorbed on the surface of the powder and will not be transferred with the liquid water, thereby ensuring that the rendering effect is stable throughout the drying process.

[0075] The embodiments of the present application may also be dried by vacuum drying, freeze drying, microwave drying, supercritical fluid drying, or by a combination of the above drying methods.

[0076] In some embodiments, the raw materials for preparing powder cosmetics include a powder phase component, an oil phase component, and a water phase component, and the raw materials form an oil-in-water emulsion system, wherein:

[0077] The powder phase components include: one or more of fillers and colorants;

[0078] The oil phase components include: one or more of: emollients, antioxidants, and sunscreens;

[0079] The aqueous phase components include: one or more of solvents, thickeners, film formers, moisturizers, emulsifiers, preservatives, and active ingredients.

[0080] In the embodiment of the present application, the raw materials form an oil-in-water emulsion system, and the oil-in-water emulsion system uses water as the continuous phase, which can make the water-soluble pigment flow better and the gradient effect more natural.

[0081] In some embodiments, the thickener and film-forming agent are selected from natural water-soluble polymers or their derivatives, synthetic water-based polymers, or water-based inorganic thickeners;

[0082] The natural water-soluble polymer or its derivative is selected from at least one of alginic acid, agar, carrageenan, xanthan gum, gellan gum, crisp chondrus crispus, xanthan gum, guar gum, tamarind gum, tara gum, gum arabic, tragacanth gum, tara gum, pectin, arabogalactan, wheat protein, soy protein, gelatin, casein, chitosan, curdlan, cyclodextrin, hyaluronic acid, konjac gum, tremella polysaccharide, codyl gum, microcrystalline cellulose, methylcellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, starch phosphate, starch, sodium hydroxymethyl starch, sodium polyacrylate grafted starch, and hydroxypropyl guar gum;

[0083] The synthetic water-based polymer is selected from at least one of acrylates / C10-30 alkyl acrylate crosspolymer, carbomer, acrylates / octylacrylamide copolymer, acrylates / ethylhexyl acrylate copolymer, sodium acrylate / sodium acryloyldimethyl taurate copolymer, acrylates / octylacrylamide copolymer, styrene / acrylates copolymer, acrylates copolymer, hydroxyethyl acrylate / sodium acryloyldimethyl taurate copolymer, polyacrylate crosspolymer-6, acrylates / stearyl ether-20 methacrylate copolymer, ammonium acryloyldimethyl taurate / beheneth-25 methacrylate crosspolymer, ammonium acrylates copolymer, sodium polyacrylate, sodium polyacryloyldimethyl taurate, polyacrylamide, polyvinyl pyrrolidone, polyvinyl alcohol, VP / VA copolymer, polyurethane-1, and polyurethane-35;

[0084] The aqueous inorganic thickener is selected from at least one of magnesium aluminum silicate, sodium magnesium lithium silicate, lithium magnesium silicate, sodium magnesium silicate, montmorillonite or their derivatives;

[0085] In some embodiments, the emollient is selected from at least one of alcohols, silicone oils, mineral oils, synthetic oils, animal and plant oils, or derivatives thereof;

[0086] The animal or plant oil or its derivative is selected from at least one of glycerin, propylene glycol, dipropylene glycol, pentylene glycol, butylene glycol, ethylene glycol, hexylene glycol, sorbitol, xylitol, polyethylene glycol, dimethicone, caprylyl methicone, phenyl trimethicone, cetyl dimethicone, C30-45 alkyldimethylsilyl polypropyl silsesquioxane, bis-PEG-18 methyl ether dimethyl silane, white mineral oil, petrolatum, hydrogenated polyisobutene, lanolin and its derivatives, octyldodecanol, caprylic / capric triglyceride, ethylhexyl palmitate, bis-diglyceryl polyacyl adipate-2, isononyl isononanoate, jojoba seed oil, coconut oil, hydrogenated coconut glycerides, meadowfoam seed oil, olive oil, squalane, C9-12 alkane, coconut alcohol-caprylate / caprate, tocopheryl acetate, and methyl gluceth-10;

[0087] In some embodiments, the filler is selected from at least one of mica, talc, synthetic fluorphlogopite, kaolin, bentonite, boron nitride, bismuth oxychloride, silica, sodium potassium aluminum silicate, lauroyl lysine, magnesium stearate, magnesium myristate, calcium aluminum borosilicate, tin oxide, calcium sodium borosilicate, aluminum hydroxide, zinc stearate starch and its derivatives, and plastic microbeads.

[0088] In some embodiments, the preservative is selected from at least one of phenoxyethanol, parabens, chlorphenesin, potassium sorbate, sodium benzoate, or preservative enhancers.

[0089] The preservative synergist is selected from at least one of caprylyl glycol, p-hydroxyacetophenone, ethylhexylglycerin, 1,2-hexanediol, caprylhydroxamic acid, 1,2-pentanediol, glyceryl caprylate, and cymene;

[0090] In a second aspect, an embodiment of the present application provides a powder cosmetic with a gradient color effect, characterized in that it is prepared by any of the above methods; optionally, the powder cosmetic is selected from pressed powder, blush or eye shadow.

[0091] The powder cosmetics prepared in the examples of the present application have a natural gradient blooming effect.

[0092] In some embodiments, the powder cosmetics with gradient color effects are selected from pressed powder, blush, eye shadow or highlighter powder. The powder cosmetics with gradient color effects may also include products with other functions.

[0093] Example

[0094] The following examples describe the present disclosure in more detail. These examples are intended for illustrative purposes only, as various modifications and variations within the scope of the present disclosure will be apparent to those skilled in the art. Unless otherwise stated, all parts, percentages, and ratios reported in the following examples are by mass, and all reagents used in the examples are commercially available or synthesized according to conventional methods and can be used directly without further processing. The instruments used in the examples are commercially available.

[0095] Example 1

[0096] (1) Mixing: Provide the following raw materials: Phase A: water, binder, potassium chloride solution, emulsifier, oil, VE; Phase B: synthetic fluorphlogopite, silica; Phase C: pearlescent agent; Phase D: preservative. The temperature of the mixing process is controlled within the range of 60-65°C. Heat Phase A, add Phases B, C, and D, and emulsify and homogenize. After emulsification and homogenization, vacuum degassing is performed to obtain a mixed material. The viscosity of the mixed material at 25°C is 5000 cP and is ready for filling.

[0097] (2) Coloring: Provide a silicone mold having an upwardly open cavity with an embossed three-dimensional pattern at the bottom of the cavity; dilute the water-soluble pigment CI 42090 with water to form a pigment solution with a mass percentage concentration of 3%, and apply the pigment solution to the preset positions at the bottom of the cavity of the silicone mold.

[0098] (3) Filling: Fill the mixture into the mold from the center of the mold according to the preset amount;

[0099] (4) Freezing: Place the mold filled with the mixed material in a freezer at -15°C to freeze the mixture to obtain a powdered masterbatch;

[0100] (5) Demolding: Separate the powdered product from the mold;

[0101] (6) Drying: The powdered product after demoulding is baked to obtain powdered cosmetics.

[0102] Examples 2-5

[0103] The difference between Examples 2-5 and Example 1 is that the mass percentage concentration of the pigment solution or the viscosity of the mixed material body is different.

[0104] Examples 6-9

[0105] The difference between Examples 6-9 and Example 1 is that, after the filling step, an auxiliary diffusion step is performed on the material body in the mold.

[0106] The assisted diffusion step of Example 6 is baking, and the mixed material body is evenly baked at 50°C.

[0107] The assisted diffusion step of Example 7 is baking, and the baking temperature increases gradually from the edge area to the center area of the mixture body; the baking temperature of the edge area of the mixture body is 30°C, and the baking temperature of the center area of the mixture body is 70°C.

[0108] The assisted diffusion step in Examples 8 and 9 is microwave heating, the microwave frequencies in the microwave cavity are 0.3 GHz and 0.5 GHz, and the microwave heating time is 3 min and 2 min.

[0109] Examples 10-12

[0110] The difference between Examples 10-12 and Example 1 is that the step of freezing the material body in the mold is performed in a liquid nitrogen tunnel.

[0111] Example 13

[0112] The difference between Example 13 and Example 1 is that the drying step adopts vacuum freeze drying. Specifically, vacuum freeze drying includes pre-freezing, sublimation drying and desorption drying. Pre-freezing specifically includes: freezing at -40℃~-50℃ for 0.5h-2h. Sublimation drying includes: first heating treatment to -3℃~3℃, the heating treatment includes several first heating stages and several first insulation stages, and the first heating stages and the first insulation stages are alternated; the first heating stage is heated at 0.5~1℃ / min for 10~20min, and the first insulation time is 1.5~2h. Desorption drying includes: drying treatment at 20℃~60℃, the drying treatment includes several second heating stages and several second insulation stages, and the second heating stage is alternated with the second insulation stage; the second heating stage is heated at 0.5~1℃ / min for 10~20min, and the second insulation time is 1.5h~2h.

[0113] Example 14

[0114] The difference between Example 14 and Example 1 is that after the filling step, the material in the mold is subjected to microwave-assisted diffusion; the step of freezing the material in the mold is carried out in a liquid nitrogen tunnel; the drying step adopts vacuum freeze drying, and the specific steps of freeze drying are the same as the freeze drying steps in Example 13.

[0115] Example 15

[0116] The difference between Example 15 and Example 1 is that after the filling step, the material body in the mold is baked; the step of freezing the material body in the mold is carried out in a liquid nitrogen tunnel; the drying step adopts vacuum freeze drying, and the specific steps of freeze drying are the same as the freeze drying steps in Example 13; step (2) is the coloring step, in which water-soluble pigments CI19140 and CI 42090 are premixed to obtain a combination pigment of the desired color, which is then diluted with water in different proportions to obtain several pigment solutions of different concentrations, and the pigment solutions are respectively applied to preset positions on the bottom periphery of the mold cavity.

[0117] Example 16

[0118] The difference between Example 16 and Example 15 lies in the coloring step (2), in which the water-soluble pigment Cl42090 is diluted with water in a certain ratio (blue); the water-soluble pigment CI17200 is diluted with water in a certain ratio (red); the water-soluble pigments CI42090 and CI17200 are mixed in a certain ratio and then diluted with water (purple); the blue and red pigment solutions are respectively applied to the diagonal positions of the bottom of the mold, and the purple pigment solution is applied to the other two diagonal positions.

[0119] Comparative Examples 1 to 6

[0120] The difference between Comparative Example 1 and Example 1 is that, before filling, a pigment solution is injected into the mixed material body using a syringe, and then the material body is filled.

[0121] The difference between Comparative Example 2 and Example 1 is that after filling, the pigment solution is immediately injected into the bottom of the mold cavity using a syringe.

[0122] The difference between Comparative Examples 3-6 and Example 1 lies in the difference in the concentration of the pigment solution and the viscosity of the mixture.

[0123] The parameters of mixing, coloring, filling and baking, freeze demoulding and drying of Examples 1-16 and Comparative Examples 1-6 are shown in Table 1.

[0124] Table 1 Process parameters of Examples 1 to 16 and Comparative Examples 1 to 6

[0125]

[0126] Test section

[0127] Pressed compacts were prepared according to the methods of Examples 1 to 16 and Comparative Examples 1 to 6. 100 pressed compacts were prepared for each Example or Comparative Example, and appearance observation and drop test were performed.

[0128] 1) Appearance observation

[0129] Observe the appearance of the pressed powder with the naked eye or under a microscope, including the appearance of the gradient color effect, focusing on whether the gradient color effect of the pressed powder is natural and uniform, and the smoothness of the gradient color surface.

[0130] The appearance is recorded based on the observation of more than 90% of the 100 pressed powders.

[0131] 2) Drop detection

[0132] Adjust the rotating screws on the drop test platform to adjust the flat plate to the 30cm scale; place the powder block with the front side facing up in the center of the test height.

[0133] Perform the first drop test: Press the test bench button to drop the powder block onto a hard surface. Pick up the fallen powder block and inspect its surface for cracks or breaks. If any are found, discontinue the drop test. If no abnormalities are detected, proceed to the second drop test. The procedure for this second drop test is the same as for the first. If any are found, discontinue the drop test. If no abnormalities are detected, proceed to the third drop test. The procedure for this third drop test is the same as for the first.

[0134] The ratio of the number of powder compacts that broke in each drop test to the total number of powder compacts tested in that drop test is the breakage rate for each drop test. The first breakage rate, second breakage rate, and third breakage rate for Examples 1 to 16 and Comparative Examples 1 to 6 are recorded separately. The drop resistance scoring criteria are shown in Table 2:

[0135] Table 2 Drop resistance rating standards

[0136] The sum of three rupture rates Less than 5% 5％～10％ 10％～15％ 15％～20％ 20％～25％ 25％～30％ Drop resistance rating 5 points 4 points 3 points 2 points 1 point 0 points

[0137] The above test results of Examples 1 to 16 and Comparative Examples 1 to 6 are recorded in Table 3.

[0138] Table 3 Test results of Examples 1 to 16 and Comparative Examples 1 to 6

[0139]

[0140]

[0141] The test results shown in Table 3 indicate that Examples 1-16 employ the present invention's method for preparing powder cosmetics with a gradient color effect, producing block-shaped powder cosmetics through coloring, filling the material into a mold, and then freezing, drying, and demolding. Compared to Comparative Examples 1-6, which did not employ the present invention's method, which failed to produce a gradient color effect or exhibited less pronounced color and gradient effects, Examples 1-16 significantly improved filling efficiency, the natural and uniform gradient color effect, and the smoothness of the gradient surface. They also significantly reduced the powder puff breakage rate during drop testing.

[0142] In the method for preparing powder cosmetics with a gradient color effect provided in this application, parameters such as the initial concentration of the pigment solution, the viscosity of the mixture, and the temperature and time control for curing the powder product at low temperatures also affect the technical effects achieved in this application. This application also provides optimal ranges for these process parameters to further enhance the various properties of the powder cosmetics with a gradient color effect produced according to the method provided in this application. For example, in Examples 6 to 9, assisted diffusion is performed after filling, and the gradient color range that can be formed is larger than that of Examples 1-5. In particular, the assisted diffusion through gradient baking and microwave heating can avoid the phenomenon that the pigment molecules in the edge area of the material body diffuse faster than those in the central area during the preparation process, the interference with the gradient effect is reduced, and the gradient is softer and more natural; in Examples 10 to 12, ultra-low temperature pre-freezing is performed in a liquid nitrogen tunnel, which not only forms a gradient color effect, but also makes the gradient color more obvious than that of Examples 1-5, and no color loss occurs after drying; Example 13 adopts vacuum freeze drying including pre-freezing, sublimation drying and analytical drying, which not only forms a gradient color effect, but also makes the gradient color more obvious than that of Examples 1-5, and no color loss occurs after drying; Examples 14-16 form better gradient color effects by adjusting the process parameters, the interference with the gradient effect is reduced, the gradient is soft and natural, the color is obvious, and no color loss occurs after drying. For the product effect of Example 15, please refer to the attached Figure 1 The product effect of Example 16 is shown in the attached Figure 2 .

[0143] In Comparative Examples 1 to 6, which do not implement the preparation steps using the method provided in this application, powder cosmetics with a gradient color effect cannot be obtained.

[0144] In Comparative Example 1, the pigment solution was injected into the mixed material using a syringe before filling. This resulted in a shading effect on the surface, but it failed to create a directional, natural gradient. In Comparative Example 2, the pigment solution was injected into the bottom of the mold cavity immediately after filling. This resulted in only localized pigment diffusion and the introduction of air into the material, disrupting its internal compactness. This resulted in holes, cracks, and pigment spots in the finished powder, and poor drop resistance. In Comparative Example 3, the material viscosity was too low, causing excessive pigment diffusion within the material. If multiple colors were mixed, they might all blend together, resulting in a single color. Furthermore, the low viscosity made the powder soft after forming, resulting in poor drop resistance. In Comparative Example 4, the material viscosity was too high, hindering pigment diffusion and resulting in a less pronounced rendering effect. In Comparative Example 5, the pigment solution concentration was too low, resulting in a less pronounced shading effect. In Comparative Example 6, the pigment solution concentration was too high: pigment accumulation occurred locally within the material, and the surface was uneven after drying.

[0145] The above examples 1 to 16 and comparative examples 1 to 6 fully demonstrate that the preparation method provided in the present application has outstanding beneficial effects and can prepare powder cosmetics with natural blooming and gradient color effects.

[0146] The above description is merely a specific embodiment of the present application, but the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in the present application, and such modifications or substitutions should be included in the scope of protection of the present application. Therefore, the scope of protection of the present application should be based on the scope of protection of the claims.

Claims

1. A method for preparing powder cosmetics with a gradient color effect, characterized in that: The steps include: Mixing: providing raw materials for preparing powder cosmetics, mixing them to obtain a mixed material; Cloth color: providing a mold, wherein the mold has at least one cavity opening upward; Taking at least one water-soluble pigment, diluting it separately to obtain at least one pigment solution, and applying the at least one pigment solution to at least one preset position on the bottom of the chamber; Filling: Filling the mixture into the mold after coloring according to a preset amount, and the water-soluble pigment diffuses directionally in the mixture under the action of the concentration gradient; Assisted diffusion: The mixed material body in the mold is baked or microwave-heated, the baking temperature is 30-70° C., and the baking time is 5 minutes to 1 hour; during the baking, the baking temperature increases gradually from the edge area to the center area of the mixed material body; the microwave heating frequency is 0.2-1 GHz, and the microwave heating time is 20 seconds to 5 minutes; Freezing: Freeze the material in the mold at low temperature to obtain a powdered masterbatch; Demoulding: Separate the powdered product from the mould; Drying: Dry the powdered masterbatch after demoulding to obtain powder cosmetics with gradient color effect; The mass percentage concentration of the pigment solution is 0.1% to 10%; The viscosity of the mixture at 25° C. is 1000 to 15000 cP.

2. The method for preparing powder cosmetics with gradient color effect according to claim 1, characterized in that: The mold is made of TPR, TPE, silicone, silicone rubber, rubber or metal; the bottom of the cavity of the mold has or does not have a three-dimensional pattern.

3. The method for preparing powder cosmetics with gradient color effect according to claim 1, characterized in that: The gradient color effect is formed on the contact surface between the powder cosmetics and the bottom of the cavity and extends toward the interior of the powder cosmetics.

4. The method for preparing powder cosmetics with gradient color effect according to claim 1, characterized in that: In the filling step, the mixed material body is filled into the mold from different directions to achieve control of the diffusion direction of the water-soluble pigment.

5. The method for preparing powder cosmetics with gradient color effect according to claim 1, characterized in that: The mass percentage concentration of the pigment solution is 0.5% to 5%; the viscosity of the mixture at 25° C. is 2000 to 5000 cP.

6. The method for preparing powder cosmetics with gradient color effect according to claim 1, characterized in that: The baking temperature of the edge area of the mixed material body is 30-40°C, and the baking temperature of the central area of the mixed material body is 60-70°C.

7. The method for preparing powder cosmetics with gradient color effect according to claim 1, characterized in that: The microwave heating frequency is 0.3-0.5 GHz, and the microwave heating time is 2-3 minutes.

8. The method for preparing powder cosmetics with gradient color effect according to claim 1, characterized in that: The step of freezing the material in the mold at low temperature is carried out in a liquid nitrogen quick-freezing device; the temperature inside the liquid nitrogen quick-freezing device is -120°C to -70°C.

9. The method for preparing powder cosmetics with gradient color effect according to claim 8, characterized in that: The liquid nitrogen quick-freezing device is a liquid nitrogen tunnel. The material body passes through the liquid nitrogen tunnel on a conveyor belt in the liquid nitrogen tunnel at a speed of 0.6 to 1 meter per minute. The powdered mother product passes through the liquid nitrogen tunnel for 6 to 10 minutes.

10. The method for preparing powder cosmetics with gradient color effect according to claim 8, characterized in that: The temperature inside the liquid nitrogen quick-freezing device is -95°C to -80°C.

11. The method for preparing powder cosmetics with gradient color effect according to claim 1, characterized in that: The drying includes one or any combination of vacuum drying, freeze drying, microwave drying and supercritical fluid drying.

12. The method for preparing powder cosmetics with gradient color effect according to claim 11, characterized in that: The drying is vacuum freeze drying.

13. The method for preparing powder cosmetics with gradient color effect according to claim 1, characterized in that: The raw materials for preparing powder cosmetics include a powder phase component, an oil phase component and a water phase component, and the raw materials form an oil-in-water emulsion system, wherein: The powder phase components include: one or more of fillers and colorants; The oil phase components include: one or more of: moisturizing agents, antioxidants, and sunscreens; The aqueous phase components include: one or more of a solvent, a thickener, a film former, a moisturizer, an emulsifier, a preservative, and an active ingredient.

14. A powder cosmetic with a gradient color effect, characterized in that: Prepared by the method according to any one of claims 1 to 13.

15. The powder cosmetic with gradient color effect according to claim 14, characterized in that: The powder cosmetics are selected from pressed powder, blush, eye shadow or highlighter.

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