Cosmetic loose powder and preparation method thereof

Abstract

The invention provides cosmetic loose powder and a preparation method thereof, the cosmetic loose powder provided by the invention at least contains a filler, an emollient and a solvent, and does not contain silica silylate; the bulk density of the cosmetic loose powder is 0.250 to 0.464 g / cm < 3 >; the mass percent of the solvent in the loose powder for making up is 2-20%. In the preparation process of the loose powder for making up, the solvent is dried by adopting a vacuum freeze drying process. According to the preparation method, the traditional concept that loose powder basically does not contain water is abandoned, a method for realizing a water-in-powder system by adopting an organic silicon compound is not imitated, and the powder with certain solvent content and bulk density is prepared on the basis of a vacuum freeze-drying process; the powder has enough bulkiness, and the loose powder for make-up has good fitness after being used for make-up.

Description

Technical Field

[0001] The invention relates to the technical field of cosmetics, and in particular to a cosmetic loose powder and a preparation method thereof. Background Art

[0002] Powder cosmetics can be in the form of compact powder or loose powder. Among them, loose powder cosmetics are loose powder, also known as "setting powder" or "honey powder", which is applied by users after foundation lotion or foundation cream for post-beauty modification and makeup touch-up.

[0003] In the existing technology, in the preparation process of cosmetic powder products, solvents (such as water) are required to complete the processes of raw material mixing, shaping or transporting, and the solvents are removed at the later stage of the preparation process. The traditional view is that the residual solvent in loose powder will make the loose powder not fluffy, affecting the usability of the loose powder. Therefore, traditional loose powder is almost solvent-free, and all the solvents introduced in the early stage need to be removed as much as possible through the drying step at the end of the preparation process. However, due to the loose and fluffy characteristics of loose powder, its docility after use on the skin often does not reach the most ideal state.

[0004] In recent years, a water-based loose powder has emerged, which uses silica silylate (an organic silicon compound, which is different from the inorganic silicon dioxide silica commonly used in cosmetics) as a carrier to achieve a powder-in-water system, with the content of water and polyols usually ranging from 30% to 60%. However, this powder-in-water system is easy to dry out, the formula stability is poor, and it is easy to agglomerate during transportation and use, resulting in lumps, which affects the use and appearance. Summary of the invention

[0005] In view of the deficiencies in the prior art, the purpose of the present invention is to provide a cosmetic loose powder and a preparation method thereof, which abandons the traditional concept that loose powder is substantially free of water, and does not follow the practice of using silicone compounds to achieve a powder-in-water system. Instead, it is based on a vacuum freeze-drying process to prepare a cosmetic loose powder having a certain solvent content and bulk density, a powder having sufficient fluffiness, and good adherence after application.

[0006] The above-mentioned object of the present invention is achieved through the following technical solutions:

[0007] In a first aspect, the present application provides a cosmetic loose powder and a preparation method thereof, comprising at least a filler, an emollient and a solvent, wherein the cosmetic loose powder does not contain silica silylate; the mass percentage content of the solvent in the cosmetic loose powder is 2 to 20%, and the bulk density of the cosmetic loose powder is 0.250 to 0.464 g / cm 3 During the preparation of the cosmetic loose powder, a vacuum freeze-drying process is used to dry the solvent in the cosmetic loose powder.

[0008] Optionally, in the cosmetic loose powder provided in the present application, the mass percentage content of the solvent in the cosmetic loose powder is 5 to 16%, and the bulk density of the cosmetic loose powder is 0.263 to 0.456 g / cm 3 .

[0009] Optionally, in the cosmetic loose powder provided in the present application, the mass percentage content of the solvent in the cosmetic loose powder is 8 to 14%, and the bulk density of the cosmetic loose powder is 0.270 to 0.420 g / cm 3 .

[0010] According to the first aspect of the present application, the solvent is selected from one or more of deionized water, plant extract and plant fermentation liquid.

[0011] According to the first aspect of the present application, the cosmetic loose powder further comprises one or more of a surface modifier, a preservative, an antioxidant, a sunscreen, and an active ingredient.

[0012] According to the first aspect of the present application, the filler is selected from one or more of mica, synthetic fluorphlogopite, boron nitride, bismuth oxychloride, silica, sodium potassium aluminum silicate, lauroyl lysine, calcium aluminum borosilicate, calcium sodium borosilicate, starch and its derivatives, and plastic microbeads.

[0013] According to the first aspect of the present application, the emollient is selected from at least one of vegetable oils, silicone oils, triethylhexanoin, bis-diglycerol polyacyl adipate-2, isononyl isononanoate, lauryl laurate, hydrogenated polydecene, cetyl ethylhexanoate, diisostearyl malate, glycolipids, and octyldodecanol stearoylstearate.

[0014] According to the first aspect of the present application, the surface modifier is selected from at least one of triethoxycaprylylsilane, polydimethylsiloxane, hydrogenated polydimethylsiloxane, and isopropyl titanium triisostearate.

[0015] According to the first aspect of the present application, the preservative is selected from at least one of phenoxyethanol, parabens, chlorphenesin, potassium sorbate, sodium benzoate or a preservative synergist; the preservative synergist is selected from at least one of caprylyl glycol, parahydroxyacetophenone, ethylhexylglycerin, 1,2-hexanediol, caprylhydroxamic acid, 1,2-pentanediol, glyceryl caprylate and cymene.

[0016] According to the first aspect of the present application, the antioxidant is selected from at least one of dipalmitoyl hydroxyproline, tocopherol acetate, pentaerythritol tetrakis (di-tert-butyl hydroxyhydrocinnamate), and tocopherol.

[0017] According to the first aspect of the present application, the mass parts of the filler, emollient, surface modifier, preservative, antioxidant and active ingredient range as follows: filler 55-95 parts; emollient 1-20 parts; surface modifier 0.01-5 parts; preservative 0.1-2 parts; antioxidant 0.05-1 parts; sunscreen 0-5 parts, active ingredient 0-5 parts.

[0018] The second aspect of the present application provides a method for preparing the cosmetic loose powder described in the first aspect, comprising the following steps: mixing: providing raw materials for preparing the cosmetic loose powder, mixing, and obtaining a mixed material body; filling: filling the mixed material body into a container according to a preset amount; pre-freezing: pre-freezing the mixed material body in the container; drying: performing vacuum freeze-drying on the pre-frozen mixed material body until the mass percentage content of the solvent in the cosmetic loose powder is reduced to the range, thereby obtaining the cosmetic loose powder.

[0019] According to the second aspect of the present application, the step of filling the mixed material body into the container according to a preset amount includes: filling the mixed material body into the container under the action of gravity or air pressure at room temperature or in a heated state.

[0020] According to the second aspect of the present application, the step of pre-freezing the mixed material body in the container adopts liquid nitrogen tunnel freezing, and the temperature of the liquid nitrogen freezing is -85 to -70°C.

[0021] According to the second aspect of the present application, the step of pre-freezing the mixed material body in the container adopts high-pressure freezing, and the temperature of the high-pressure freezing is -20 to -40°C and the pressure is 50 to 100 MPa.

[0022] According to the second aspect of the present application, the vacuum negative pressure freeze drying comprises at least: using a freeze dryer to freeze dry the mixture frozen into a solid state, and allowing the solvent in the mixture to directly sublime into a gaseous state under vacuum and remove it to a preset content range.

[0023] In summary, the present invention includes at least one of the following beneficial technical effects:

[0024] Compared with the prior art, in order to solve the shortcoming of poor adherence of traditional loose powder after application, the present application abandons the traditional concept that loose powder is basically solvent-free, and provides a cosmetic loose powder with a solvent content of 2-20%, preferably 5-16%, and more preferably 8-14%. At the same time, the inventors noticed that if the loose powder is dried to the above solvent content by conventional drying methods (such as heating and drying, etc.), the prepared loose powder will not be fluffy and its usability will be greatly affected.

[0025] In this regard, the present application adopts a vacuum freeze drying process to dry the loose powder to the above solvent content, so that the cosmetic loose powder obtained after drying has a viscosity of 0.250 to 0.464 g / cm 3 , preferably 0.263 to 0.456 g / cm 3 , more preferably 0.270 to 0.420 g / cm 3 The bulk density characteristics not only have good fit, but also good fluffiness. Vacuum freeze drying is to remove the solvent frozen as ice crystals in the material body by sublimating it directly into gas without passing through the liquid state. Compared with other drying methods, vacuum freeze drying optimizes the morphology and energy transfer process during the formation and removal of ice crystals in the material body, which has a key impact on the texture of loose powder. The cosmetic loose powder provided in this application maintains sufficient fluffiness and has good fit after makeup. DETAILED DESCRIPTION

[0026] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is only to provide a better understanding of the present application by illustrating the examples of the present application.

[0027] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, the elements defined by the statement "include..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0028] In the prior art, the fluffiness and fit of loose powder are considered to be mutually exclusive: the residual solvent in the loose powder makes the loose powder not fluffier, which affects the usability of the loose powder. Therefore, traditional loose powder contains almost no solvent, and at the end of the preparation process, all the solvent introduced in the early stage should be removed as much as possible through the drying step, so that the loose powder has the characteristics of being loose and fluffy. However, due to the characteristics of the loose powder being loose and fluffy, its fit after being applied to the skin often does not reach the most ideal state.

[0029] According to the first aspect of the present application, an embodiment of the present application provides a cosmetic loose powder, comprising at least a filler, an emollient and a solvent, wherein the cosmetic loose powder does not contain silica silylate; the mass percentage content of the solvent in the cosmetic loose powder is 2 to 20%, and the bulk density of the cosmetic loose powder is 0.250 to 0.464 g / cm 3 During the preparation of the cosmetic loose powder, a vacuum freeze-drying process is used to dry the solvent in the cosmetic loose powder.

[0030] In the embodiments of the present application, the traditional concept that loose powder is basically solvent-free is abandoned, and a solvent-containing loose powder with a solvent content of 2 to 20% is provided. At the same time, the embodiments of the present application use a vacuum freeze-drying process to dry the solvent in the cosmetic loose powder to the solvent content. Vacuum freeze-drying is to freeze the solvent-containing material in a frozen state, and directly sublimate the solvent frozen into ice crystals in the material body into a gaseous state without passing through a liquid state. Compared with other drying methods, vacuum freeze-drying optimizes the morphology and energy transfer process during the formation and removal of ice crystals in the material body, which has a key impact on the texture of the loose powder, so that the prepared cosmetic loose powder can have a certain solvent residue content of 0.250 to 0.464 g / cm 3 The bulk density of the present application is 0.250-0.464 g / cm2, which is prepared by vacuum freeze drying process and has a solvent content of 2-20%. 3 The cosmetic loose powder not only has good fluffiness, but also has good adherence after application.

[0031] In some embodiments of the present application, the mass percentage content of the solvent in the cosmetic loose powder is 5 to 16%, and the bulk density of the cosmetic loose powder is 0.263 to 0.456 g / cm 3 .

[0032] In some embodiments of the present application, the mass percentage content of the solvent in the cosmetic loose powder is 8-14%, and the bulk density of the cosmetic loose powder is 0.270-0.420 g / cm 3 .

[0033] By further controlling the water content of the solvent within the preferred range, the bulk density of the cosmetic loose powder is further optimized, so that the overall performance of the loose powder in terms of fluffiness and fit after application is better.

[0034] In some embodiments of the present application, the solvent is selected from one or more of deionized water, plant extract and plant fermentation liquid.

[0035] In some embodiments of the present application, the cosmetic loose powder further comprises one or more of a surface modifier, a preservative, an antioxidant, a sunscreen, and an active ingredient.

[0036] In some embodiments of the present application, the filler is selected from one or more of mica, synthetic fluorphlogopite, boron nitride, bismuth oxychloride, silica, sodium potassium aluminum silicate, lauroyl lysine, calcium aluminum borosilicate, calcium sodium borosilicate, starch and its derivatives, and plastic microbeads.

[0037] In some embodiments of the present application, the emollient is selected from at least one of vegetable oils, silicone oils, triethylhexanoin, bis-diglycerol polyacyl adipate-2, isononanoate, lauryl laurate, hydrogenated polydecene, cetyl ethylhexanoate, diisostearyl malate, glycolipids, and octyldodecanol stearoyl stearate.

[0038] In some embodiments of the present application, the surface modifier is selected from at least one of triethoxycaprylylsilane, polydimethylsiloxane, hydrogenated polydimethylsiloxane, and isopropyl titanium triisostearate.

[0039] In some embodiments of the present application, the preservative is selected from at least one of phenoxyethanol, parabens, chlorphenesin, potassium sorbate, sodium benzoate or a preservative synergist; the preservative synergist is selected from at least one of caprylyl glycol, parahydroxyacetophenone, ethylhexylglycerin, 1,2-hexanediol, caprylhydroxamic acid, 1,2-pentanediol, glyceryl caprylate, and cymene.

[0040] In some embodiments of the present application, the antioxidant is selected from at least one of dipalmitoyl hydroxyproline, tocopherol acetate, pentaerythritol tetrakis (di-tert-butyl hydroxyhydrocinnamate), and tocopherol.

[0041] In some embodiments of the present application, the active ingredient is selected from a high temperature sensitive active ingredient or a high temperature insensitive active ingredient; the high temperature sensitive active ingredient is selected from at least one of polypeptide active ingredients, astaxanthin, vitamin A alcohol or its derivatives, vitamin C or its derivatives, and arbutin.

[0042] In some embodiments of the present application, the mass ranges of the filler, emollient, surface modifier, preservative, antioxidant and active ingredient, in parts by mass, are: filler 55-95 parts; emollient 1-20 parts; surface modifier 0.01-5 parts; preservative 0.1-2 parts; antioxidant 0.05-1 parts; sunscreen 0-5 parts, and active ingredient 0-5 parts.

[0043] According to the second aspect of the present application, an embodiment of the present application further provides a method for preparing the cosmetic loose powder described in the first aspect, comprising the following steps: mixing: providing raw materials for preparing the cosmetic loose powder, mixing, and obtaining a mixed material body; filling: filling the mixed material body into a container according to a preset amount; pre-freezing: pre-freezing the mixed material body in the container; drying: performing vacuum freeze-drying on the pre-frozen mixed material body until the mass percentage content of the solvent in the cosmetic loose powder is reduced to the range, thereby obtaining the cosmetic loose powder.

[0044] The raw materials for preparing cosmetic loose powder can be purchased commercially or homemade. It is understood that the raw materials for preparing cosmetic loose powder generally include a powder phase component, an oil phase component and an aqueous phase component. The raw materials can be mixed in various ways commonly used in the prior art to add the raw materials step by step and mix them evenly, such as mechanical stirring, etc., and homogenization, defoaming and other operations can be added during the mixing process. Different mixing methods and steps can be used according to different raw materials, and the present application is not limited thereto.

[0045] In the filling step, the preset amount can be set according to the volume of the block powder cosmetics, the container capacity or the filling needs, and the preset amount filled each time can be the same or different. The step of filling the mixed material body into the container according to the preset amount includes: filling the mixed material body into the container under the action of gravity or air pressure at room temperature or under heating.

[0046] In some embodiments of the present application, the mixed material body is heated and then filled into the container by gravity filling. For example, the heating temperature of the mixed material body can be 50-80°C.

[0047] In some embodiments of the present application, the mixed material body is filled into the container via an air pressure feeding device. For example, the mixed material body can be pressed into or sucked into the container by the action of air pressure.

[0048] The present application does not limit the specific method of filling the material into the container according to the preset amount. The material can be pressed into the container by the action of air pressure. For example, the air pressure feeding device includes a feeding pipe, an air pump and a discharging pipe. The air pump provides conveying air pressure to suck the material from the feeding pipe into the air pressure feeding device and then press it into the container through the discharging pipe. The material can also be sucked into the container by the action of air pressure. For example, the air pressure feeding device is connected to the container, and the air pressure feeding device provides conveying air pressure to suck the material into the container. Whether the material is pressed into or sucked into the container, the fluidity of the material is required to be low, and there is no need to add too much solvent, which greatly shortens the subsequent drying time and allows the use of high-temperature sensitive active substances.

[0049] In some embodiments of the present application, the pressure in the gas pressure feeding device may be: 0.01-0.08 MPa. For example, the pressure in the gas pressure feeding device may be 0.01 MPa, 0.02 MPa, 0.03 MPa, 0.04 MPa, 0.05 MPa, 0.06 MPa, 0.07 MPa, 0.08 MPa, or a range consisting of any two of the above values.

[0050] In some embodiments of the present application, the viscosity of the material may be 5000 cP to 12000 cP. For example, the viscosity of the material may be 5000 cP, 6000 cP, 7000 cP, 8000 cP, 9000 cP, 10000 cP, 11000 cP, 12000 cP or a range consisting of any two of the above values.

[0051] After the filling step, the mixed material body is pre-frozen so that the solvent of the mixed material body is frozen into ice (or ice crystals). In some embodiments of the present application, the step of pre-freezing the mixed material body in the container adopts liquid nitrogen tunnel freezing, and the temperature of the liquid nitrogen tunnel freezing is -85℃ to -70℃.

[0052] Liquid nitrogen tunnel is also called liquid nitrogen tunnel quick freezer. It is a device that uses liquid nitrogen as a cold source, adopts a continuous production method, and sends materials into the quick freezing tunnel through a conveyor belt to achieve continuous entry and exit and rapid freezing of materials. This application uses a liquid nitrogen tunnel to perform extremely low temperature solidification on the mixed material body after filling, and the raw material components in the mixed material body undergo molecular quick freezing in an extremely low temperature environment in the liquid nitrogen quick freezing device. The cosmetic material body contains components such as oils and emulsions. During its freezing and shaping process, it will experience a maximum ice crystal formation zone, and about 80% of the liquid (water, emulsion, etc.) will turn into ice. Unlike ordinary freezing, in the molecular quick freezing process completed in the liquid nitrogen tunnel in this application, the mixed material body quickly passes through the maximum ice crystal formation zone. The generated ice crystals are evenly distributed, small and dense in the powder master product. In the subsequent vacuum freeze-drying process, the small and uniform characteristics of the ice crystals play a key role in maintaining the fluffiness and fit of the loose powder, so that the loose powder after freeze-drying has better fluffiness and fit.

[0053] In some embodiments of the present application, the step of pre-freezing the mixed material in the container adopts high-pressure freezing, and the temperature of the high-pressure freezing is -20 to -40°C and the pressure is 50 to 100 MPa.

[0054] High-pressure freezing can be carried out in a commercially available high-pressure freezer, which quickly freezes the material under a predetermined high pressure. Under different pressures, the density of ice crystals formed during the freezing process of the material is different. For example, the ice formed by water under normal atmospheric pressure is type I ice crystals, which have a lower density than water; however, the density of ice crystals formed by liquid water under higher pressure is greater than that of liquid water. At this time, the ice crystals are type II to VI ice crystals, and the structure of type II to VI ice crystals is more complex than that of type I ice crystals. Some embodiments of the present application use high-pressure freezing technology to apply pressure to the mixed material body during the pre-freezing process, so that the solvent (such as water) in the mixed material body undergoes phase change behavior during the freezing process, forming more and smaller type II to VI ice crystals, and then removing type II to VI ice crystals through vacuum freeze drying, which can make the prepared loose powder have the best fluffiness and fit, while improving the cotton softness of the loose powder.

[0055] Finally, the pre-frozen mixed material body is subjected to vacuum freeze drying, and the vacuum freeze drying at least includes: using a freeze dryer to freeze-dry the mixed material body frozen into a solid state, and allowing the solvent in the mixed material body to be directly sublimated into a gaseous state under vacuum and removed, until the mass percentage content of the solvent in the cosmetic loose powder is reduced to within the range specified in the present application.

[0056] Exemplarily, vacuum freeze drying may include freezing, sublimation drying and analytical drying. The freezing may specifically include: freezing at -42°C to -45°C for 1h-1.5 hours; the sublimation drying may specifically include: heating the material to -3°C to 3°C, the heating treatment includes several first heating stages and several first insulation stages, and the first heating stage is alternately performed with the first insulation stage; the first heating stage is heated at 0.6-0.8°C / min for 15-18min, and the first insulation time is 1.6-1.8h; the analytical drying may specifically include: drying the material at 25°C to 50°C, the drying treatment includes several second heating stages and several second insulation stages, and the second heating stage is alternately performed with the second insulation stage; the second heating stage is heated at 0.6-0.8°C / min for 15-18min, and the second insulation time is 1.6-1.8h.

[0057] Example:

[0058] The following examples describe the disclosure of the present application in more detail, and these examples are for illustrative purposes only, as various modifications and variations within the scope of the disclosure of the present application are 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 treatment, and the instruments used in the examples are commercially available.

[0059] Recipe 1-2:

[0060] Illustratively, the present application provides two preparation raw material compositions, proportions and mixing methods for cosmetic loose powders.

[0061] The raw material components of the cosmetic loose powder formula 1 are shown in Table 1:

[0062] Table 1 Composition of Formula 1

[0063]

[0064] Mixing: (1) Heat phase A to 75±5°C; (2) Add phase B to phase A and homogenize and emulsify at 75±5°C; (3) Add phase C to (2) and mix evenly at 75±5°C; (4) Cool the material to 50±5°C; (5) Add D (needs to be pre-dissolved) and E to (4) and mix evenly, and vacuum degas at 50±5°C to obtain the material.

[0065] The raw material components of cosmetic loose powder formula 2 are shown in Table 2:

[0066] Table 2 Composition of Formula 2

[0067]

[0068] Mixing: (1) Mix phases B, C, and D evenly; (2) Add (1) to phase A and mix evenly at room temperature; (3) Add phase E to (2) and mix evenly at room temperature; (4) Vacuum degassing at room temperature to obtain a material body.

[0069] Embodiments 1 to 14:

[0070] The preparation of cosmetic loose powder is carried out as follows:

[0071] Mixing: providing raw materials according to the raw material components of the cosmetic loose powder formula 1, and mixing the raw materials according to the mixing steps to obtain a mixed material body;

[0072] Filling: Fill the mixed material into the container according to the preset amount;

[0073] Prefreezing: prefreezing the mixed material in the container;

[0074] Drying: vacuum freeze-drying the pre-frozen mixed material until the mass percentage content of the solvent in the cosmetic loose powder is reduced to the range, thereby obtaining the cosmetic loose powder.

[0075] Among them, vacuum freeze drying is carried out in a freeze dryer, and the vacuum freeze drying procedure includes freezing, sublimation drying and analytical drying. The freezing specifically includes: freezing at -42℃~-45℃ for 1h-1.5 hours; the sublimation drying specifically includes: heating the material to -3℃~3℃, the heating treatment includes several first heating stages and several first insulation stages, and the first heating stage is alternately carried out with the first insulation stage; the first heating stage is heated at 0.6~0.8℃ / min for 15~18min, and the first insulation time is 1.6~1.8h; the analytical drying specifically includes: drying the material at 25℃~50℃, the drying treatment includes several second heating stages and several second insulation stages, and the second heating stage is alternately carried out with the second insulation stage; the second heating stage is heated at 0.6~0.8℃ / min for 15~18min, and the second insulation time is 1.6~1.8h.

[0076] The parameters of the filling, pre-freezing and other steps used in Examples 1 to 14, the solvent content in the prepared loose powder and the bulk density of the loose powder are recorded in Table 3.

[0077] Comparative Examples 1 to 3:

[0078] The difference between Comparative Example 1 and Example 1 is that in the step of drying the solvent in the cosmetic loose powder by using a vacuum freeze-drying process, the mass percentage content of the solvent in the cosmetic loose powder is dried to 1%.

[0079] The difference between Comparative Example 2 and Example 1 is that in the step of drying the solvent in the cosmetic loose powder by using a vacuum freeze-drying process, the mass percentage content of the solvent in the cosmetic loose powder is dried to 25%.

[0080] The difference between Comparative Example 3 and Example 1 is that the solvent in the cosmetic loose powder is dried by heating and drying, and the mass percentage content of the solvent in the cosmetic loose powder is dried to 14%.

[0081] Comparative Examples 1 to 3 adopt parameters of the filling, pre-freezing and other steps, and the solvent content in the prepared loose powder and the bulk density of the loose powder are recorded in Table 3.

[0082] Table 3 Parameters of Examples 1 to 14 and Comparative Examples 1 to 3

[0083]

[0084]

[0085] Product testing:

[0086] (1) Bulk density test

[0087] The bulk density of powder refers to the weight of powder per unit volume and is an important indicator for evaluating the filling degree between powder particles. The bulk density of the loose powders prepared in Examples 1 to 14 and Comparative Examples 1 to 3 was tested using a universal bulk density tester.

[0088] (2) Skin Sensation Assessment

[0089] Volunteers scored and evaluated the fluffiness, fit and cotton-soft feel of the cosmetic loose powders prepared in Examples 1 to 14 and Comparative Examples 1 to 3.

[0090] 80 people were randomly selected, with an age distribution of 18 to 45 years old. After using Examples 1 to 14 or Comparative Examples 1 to 3 to prepare loose powder, the loose powder was scored for fluffiness, makeup fit and cotton softness. The scoring standard is: 10 points are the full score; 1 to 2 points: very bad; 3 to 4 points: bad; 5 to 6: ordinary; 7 to 8: good; 9 to 10: very good. The average value of the evaluation results of 80 people (rounded to 1 decimal place) is taken as the corresponding item score of the embodiment or comparative example. The results are shown in Table 4.

[0091] Table 4 Test results of Examples 1 to 14 and Comparative Examples 1 to 3

[0092]

[0093]

[0094] From the test results shown in Table 4, it can be seen that Examples 1 to 14 adopt the preparation method of the cosmetic loose powder provided by the present application, and use a vacuum freeze-drying process to dry the solvent in the cosmetic loose powder until the mass percentage content of the solvent in the cosmetic loose powder is 2 to 20%. At this time, the bulk density of the obtained cosmetic loose powder is 0.25 to 0.464 g / cm 3 The loose powder has good fluffiness and good fit after makeup, and has satisfactory cotton softness. Examples 1 to 14 break the traditional view that the water content in the loose powder affects its fluffiness, and the loose powder should be dried to be almost free of water, and also solve the current situation that the existing loose powder for makeup has unsatisfactory fit because it is almost free of water.

[0095] In contrast, although Comparative Examples 1 and 2 use the same method to prepare cosmetic loose powder, Comparative Examples 1 and 2 do not control the solvent content in the dried cosmetic loose powder within the range specified in the present application, and the prepared loose powder has poor fluffiness or unsatisfactory fit. Although Comparative Example 3 controls the solvent content in the dried cosmetic loose powder within the preferred range specified in the present application, Comparative Example 3 does not use a vacuum freeze-drying process to dry the loose powder, but uses conventional oven drying, resulting in poor fluffiness of the cosmetic loose powder prepared in Comparative Example 3, affecting its usability. This verifies that vacuum freeze drying can optimize the morphology and energy transfer process during the generation and removal of ice crystals in the material body, and has a key impact on the texture of the loose powder, such as fluffiness.

[0096] In Examples 1 to 14, in the preparation process of cosmetic loose powder, Examples 1 to 6 use a liquid nitrogen tunnel to pre-freeze the material body, while Examples 7 to 12 use high-pressure freezing to pre-freeze the material body. Since the ice formed by the solvent water in the material body under normal atmospheric pressure is type I ice crystals, its density is lower than that of water; but the density of ice crystals formed by water under higher pressure is greater than that of liquid water. At this time, the ice crystals are type II to VI ice crystals, and the structure of type II to VI ice crystals is more complex than that of type I ice crystals. In the embodiment of the present application, high-pressure freezing is a better pre-freezing method than liquid nitrogen freezing. Examples 7 to 12 using high-pressure freezing allow the solvent (such as water) in the mixed material body to form more and smaller type II to VI ice crystals during the freezing process, and then the type II to VI ice crystals are removed by vacuum freeze drying, so that the fluffiness, fit and cotton softness of the prepared loose powder can be optimized.

[0097] In Examples 13 to 14, the mixed material is heated before filling in the filling step. The purpose of heating is to increase the fluidity of the mixed material. However, compared with the filling method using the air pressure feeding device used in Examples 1 to 12, the heating step causes the mixed material to undergo a process of heating during filling and then pre-freezing and cooling, which destroys the original bonding and molecular arrangement between the powder components to a certain extent. The evaluation results of the prepared loose powder are all reduced. In addition, it may also cause the high-temperature sensitive active substances in the loose powder raw material components to be inactivated or partially inactivated. Therefore, in the embodiment of the present application, filling using a pneumatic feeding device is a relatively better filling method.

[0098] The cosmetic loose powder and preparation method thereof provided in the present application successfully solve the current situation that the fluffiness and fit of cosmetic loose powder cannot be achieved at the same time, and provide a better prospect for the development and application of cosmetic loose powder.

[0099] The above is only a specific implementation method of the present application. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process described above can refer to the corresponding process in the aforementioned method embodiment, and will not be repeated here. It should be understood that the protection scope of the present application is not limited to this. Any technician familiar with the technical field can easily think of various equivalent modifications or replacements within the technical scope disclosed in this application, and these modifications or replacements should be included in the protection scope of the present application.

Claims

1. A cosmetic loose powder comprising at least a filler, an emollient and a solvent, characterized in that: The cosmetic loose powder does not contain silica silylate; The mass percentage content of the solvent in the cosmetic loose powder is 2-20%, and the bulk density of the cosmetic loose powder is 0.250-0.464 g / cm 3 ; During the preparation of the cosmetic loose powder, a vacuum freeze-drying process is used to dry the solvent in the cosmetic loose powder.

2. A cosmetic loose powder according to claim 1, characterized in that: The mass percentage content of the solvent in the cosmetic loose powder is 5-16%, and the bulk density of the cosmetic loose powder is 0.263-0.456 g / cm 3 .

3. A cosmetic loose powder according to claim 2, characterized in that: The mass percentage content of the solvent in the cosmetic loose powder is 8-14%, and the bulk density of the cosmetic loose powder is 0.270-0.420 g / cm 3 .

4. A cosmetic loose powder according to claim 1, characterized in that: The solvent is selected from one or more of deionized water, plant extract and plant fermentation liquid.

5. A cosmetic loose powder according to claim 1, characterized in that: The cosmetic loose powder further comprises one or more of a surface modifier, a preservative, an antioxidant, a sunscreen, and an active substance.

6. A cosmetic loose powder according to claim 5, characterized in that: The filler is selected from one or more of mica, synthetic fluorphlogopite, boron nitride, bismuth oxychloride, silica, sodium potassium aluminum silicate, lauroyl lysine, calcium aluminum borosilicate, calcium sodium borosilicate, starch and its derivatives, and plastic microbeads; and / or: The emollient is selected from at least one of vegetable oils and fats, silicone oils, triethylhexanoin, bis-diglycerol polyacyl adipate-2, isononyl isononanoate, lauryl laurate, hydrogenated polydecene, cetyl ethylhexanoate, diisostearyl malate, glycolipids, and octyldodecyl stearoyloxy stearate; and / or: The surface modifier is selected from at least one of triethoxyoctylsilane, polydimethylsiloxane, hydrogenated polydimethylsiloxane, and isopropyl titanium triisostearate; and / or: The preservative is selected from at least one of phenoxyethanol, parabens, chlorphenesin, potassium sorbate, sodium benzoate or preservative synergist; 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; and / or: The antioxidant is selected from at least one of dipalmitoyl hydroxyproline, tocopherol acetate, pentaerythritol tetra(di-tert-butyl hydroxyhydrocinnamate), and tocopherol; and / or: The active substance is selected from high temperature sensitive active substances or high temperature insensitive active substances, wherein the high temperature sensitive active substance is selected from at least one of polypeptide active substances, astaxanthin, vitamin A alcohol or its derivatives, vitamin C or its derivatives, and arbutin.

7. A cosmetic loose powder according to claim 5, characterized in that: In terms of parts by mass, the filler, emollient, surface modifier, preservative, antioxidant and active ingredient have the following ranges of parts by mass: filler 55-95 parts; emollient 1-20 parts; surface modifier 0.01-5 parts; preservative 0.1-2 parts; antioxidant 0.05-1 parts; sunscreen 0-5 parts, and active ingredient 0-5 parts.

8. A method for preparing a cosmetic loose powder according to any one of claims 1 to 7, characterized in that: The steps include: Mixing: providing raw materials for preparing cosmetic loose powder, mixing them to obtain a mixed material body; Filling: Fill the mixed material into the container according to the preset amount; Prefreezing: prefreezing the mixed material in the container; Drying: vacuum freeze-drying the pre-frozen mixed material until the mass percentage content of the solvent in the cosmetic loose powder is reduced to the range, thereby obtaining the cosmetic loose powder.

9. The method for preparing a cosmetic loose powder according to claim 8, characterized in that: The step of filling the mixed material body into the container according to a preset amount specifically includes: filling the mixed material body into the container under the action of gravity or air pressure at room temperature or in a heated state.

10. The method for preparing a cosmetic loose powder according to claim 8, characterized in that: The step of pre-freezing the mixed material in the container adopts liquid nitrogen freezing, and the temperature of the liquid nitrogen freezing is -85~-75℃.

11. The method for preparing a cosmetic loose powder according to claim 8, characterized in that: The step of pre-freezing the mixed material in the container adopts high-pressure freezing, and the temperature of the high-pressure freezing is -20~-40°C and the pressure is 50~100MPa.

12. The method for preparing a cosmetic loose powder according to claim 8, characterized in that: The vacuum freeze drying specifically comprises the following steps: using a freeze dryer to freeze dry the mixture body frozen into a solid state, and allowing the solvent in the mixture body to directly sublime into a gaseous state under vacuum and remove it to a preset content range.

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