Natural grease-containing Pickering emulsion and preparation thereof
By introducing phase change materials, especially PEG/PVA composite phase change materials, the problem of oxidation of the active ingredients of rose hip oil at room temperature is solved, the effect of temperature stability and structural stability is achieved, and the product's shelf life is extended.
Patent Information
- Application Number
- CN202510466866.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-15
- Publication Date
- 2025-07-08
AI Technical Summary
Active ingredients such as vitamin C and linolenic acid in rose hip oil are easily oxidized at room temperature, especially at a faster rate at above 26°C, resulting in a reduced product efficacy and shortened shelf life.
Phase change materials, especially PEG/PVA composite phase change materials, are introduced to absorb heat through the phase change process to maintain temperature stability and reduce the oxidation of active ingredients.
Effectively inhibit the oxidation of active ingredients of rose hip oil, extend the product shelf life, and maintain the structural stability of the emulsion.
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Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of skin care products, and relates to a Pickering emulsion containing natural oil and its preparation. Background Art
[0002] In the fields of cosmetics and skin care products, Pickering emulsions have great application potential due to their high stability brought by solid particle stabilization, which can effectively reduce the irritation to the skin. Natural oils such as rosehip oil are widely added to skin care products because they are rich in active ingredients such as vitamin C and linolenic acid.
[0003] However, at room temperature, the active ingredients such as vitamin C and linolenic acid in rosehip oil will be oxidized and inactivated. Especially when the environmental temperature exceeds 26°C, the oxidation rate will increase. This will not only reduce the product efficacy but also shorten the shelf life. Summary of the Invention
[0004] The purpose of the present invention is to provide a Pickering emulsion containing natural oil and its preparation. By introducing a phase change material, the present invention maintains the temperature stability of the Pickering emulsion, reduces the oxidation of the active ingredients in rosehip oil, and prolongs the shelf life of the product.
[0005] The purpose of the present invention can be achieved by the following technical solutions:
[0006] In the first aspect, the present invention provides a Pickering emulsion containing natural oil and its preparation, adopting the following technical solutions:
[0007] A Pickering emulsion containing natural oil is formed by a plurality of latex particles in a stable dispersion state. The latex particles are formed by an oil phase material, an aqueous phase material wrapping the oil phase material, and a Pickering stabilizer providing a stabilizing effect at the interface between the oil phase material and the aqueous phase material.
[0008] Among them, the aqueous phase material is formed by dispersing a phase change material in an aqueous medium. The phase change material is defined as a material with a phase change temperature of 23-32°C, and the oil phase material contains at least rosehip oil.
[0009] Preferably, the phase change material is a PEG / PVA composite phase change material.
[0010] Preferably, the weight portion of the PEG / PVA composite phase change material is 3-5 portions. The raw materials of the PEG / PVA composite phase change material include PEG-800 and PVA, and the mass ratio of PEG-800 to PVA is (2-3):10.
[0011] Preferably, the preparation process of the PEG / PVA composite phase change material includes the following steps:
[0012] Dispersing PVA in water to form a PVA solution, adding PEG-800 to the PVA solution;
[0013] The PEG-800 and the PVA solution are subjected to at least one freeze-thaw operation to obtain a PEG / PVA composite phase change material, wherein the freeze-thaw operation includes first freezing and then thawing.
[0014] Preferably, the freezing temperature in the freeze-thaw operation is -25-15°C.
[0015] Preferably, the concentration of the PVA solution is 6-8wt%.
[0016] Preferably, the particle size of the PEG / PVA composite phase change material is 100-200 mesh.
[0017] Preferably, the oil phase material comprises the following components in parts by weight: 15-25 parts of rosehip oil, 9-10 parts of jojoba oil and 0.5-1.5 parts of vitamin E acetate.
[0018] Preferably, it is characterized in that the water phase material comprises the following components in parts by weight: 135-145 parts of water, 10-15 parts of glycerol and 1-2 parts of yeast / Aspergillus / rice / Opuntia cactus stem fermentation product filtrate.
[0019] In a second aspect, the present invention provides a method for preparing a Pickering emulsion containing natural oils and fats, using the following technical scheme:
[0020] A preparation method of a Pickering emulsion containing natural oils and fats comprises the following steps:
[0021] A. mixing a phase change material with an aqueous phase material to obtain an aqueous phase dispersion medium;
[0022] B. Mix the oil phase material with the aqueous dispersion medium, then add the Pickering stabilizer, fully disperse and emulsify to obtain the Pickering emulsion.
[0023] Beneficial effects of the present invention:
[0024] (1) By introducing a phase change material with a phase change temperature of 23-32°C, when the ambient temperature fluctuates, the phase change material can absorb heat in time through the phase change process, especially above 26°C, the key temperature range where the oxidation rate of the active ingredients of rosehip oil accelerates. This material can maintain the temperature of the system stable, thereby effectively inhibiting the oxidation process of active ingredients such as vitamin C and linolenic acid in rosehip oil, thereby retaining the product efficacy to the greatest extent.
[0025] (2) The phase change material of the present invention adopts a PEG / PVA composite phase change material, which remains solid during the phase change process, can maintain the structural stability of the Pickering emulsion structure, and avoid the demulsification and stratification of the Pickering emulsion caused by the volume change of the phase change material during the phase change. Detailed implementation manners
[0026] To further elaborate on the technical means and effects adopted by the present invention to achieve the predetermined invention purpose, the following, in combination with preferred embodiments, details the specific implementation manners, structures, features and their effects according to the present invention as follows.
[0027] In the fields of cosmetics and skin care products, Pickering emulsions are stable due to solid particles, have little irritation to the skin, and have broad application prospects. Rosehip oil in natural oils is rich in active ingredients such as vitamin C and linolenic acid, and has significant effects in antioxidant and skin barrier repair, and is often added to skin care products. However, the inventor found that at room temperature, the active ingredients of rosehip oil will oxidize and become inactivated. Especially when the environmental temperature exceeds 26 °C, the oxidation rate will accelerate. This not only greatly reduces the efficacy of skin care products, shortens the product shelf life, increases production costs, but also seriously affects the user experience of consumers.
[0028] When those skilled in the art attempt to solve the problem of "how to reduce the oxidation and inactivation of the active ingredients of rosehip oil at room temperature", they usually add antioxidants (such as vitamin E). Although to a certain extent, adding antioxidants can delay the oxidation process, the addition amount of vitamin E is strictly limited. Excessive addition will not only change the physical and chemical properties of the emulsion, resulting in changes in the texture and color of the product and affecting the user experience, but may also cause adverse reactions such as skin allergies. Moreover, even when added within the specified range, over time, the antioxidant will be gradually consumed. Once it is exhausted, in a room temperature environment above 26 °C, the oxidation rate of rosehip oil will accelerate, and the product shelf life is still difficult to be effectively guaranteed.
[0029] The inventor accidentally found that if the temperature stability of the Pickering emulsion can be maintained, the oxidation of the active ingredients of rosehip oil can be reduced. Based on this, the inventor proposed a solution of introducing a phase change material. The phase change material undergoes a phase change within a specific temperature range and absorbs heat, thereby maintaining the temperature stability of the system. By applying the phase change material to the Pickering emulsion containing rosehip oil, the influence of environmental temperature changes on the emulsion can be effectively buffered, the oxidation of the active ingredients of rosehip oil can be reduced, and the product shelf life can be extended.
[0030] The rosehip oil in all embodiments and comparative examples of the present invention was purchased from Jining Tangyi Chemical Co., Ltd., jojoba oil was purchased from Hubei Xingdongcheng Chemical Co., Ltd., PEG-800 was purchased from Hai'an Petrochemical Plant in Jiangsu Province, PVA was purchased from Yingchuang Technology (Guangdong) Co., Ltd., vitamin E acetate was purchased from Guangzhou Huayu Biotechnology Co., Ltd., nanosilica was purchased from Hangzhou Jikang New Materials Co., Ltd., montmorillonite was purchased from Tuoyi New Materials (Guangzhou) Co., Ltd., and the yeast / Aspergillus / rice / pear fruit cactus stem fermentation product filtrate was derived from Guangzhou Hanfang Medical Biotechnology Co., Ltd., and the registration number of the yeast / Aspergillus / rice / pear fruit cactus stem fermentation product filtrate is Guozhuangyuanbeizi 20240085.
[0031] Example 1
[0032] A Pickering emulsion containing natural oil and fat and preparation thereof, wherein the amounts of raw materials required for the preparation of the Pickering emulsion are shown in Table 1 below:
[0033] Table 1:
[0034]
[0035]
[0036] The particle size of nano-silicon dioxide is 120nm.
[0037] The preparation of PEG / PVA composite phase change material is as follows:
[0038] S1. Preparation of PVA solution: Weigh 8 g of PVA powder, add it to 92 g of deionized water, and stir it in a constant temperature water bath at 40° C. at a speed of 200 r / min for 4 h until the PVA is completely dissolved to obtain a PVA solution with a concentration of 8%.
[0039] S2. Mixing and degassing: Add 1.6 g of PEG-800 to the above PVA solution, maintain a 40°C water bath environment, stir at 300 r / min for 3 h, and fully mix the PEG-800 and PVA solution. Then transfer the mixed solution to a vacuum degassing machine and degas at a vacuum degree of -0.1 MPa for 30 min to remove bubbles in the solution.
[0040] S3, freeze-thaw treatment: Pour the degassed solution into a mold and freeze it in a -15°C freezer for 12 hours. Take out the mold and thaw it naturally at room temperature (25°C) for 8 hours. Repeat the above freeze-thaw process 4 times.
[0041] S4, Drying and grinding: The sample after freeze-thaw treatment was quickly placed in a freeze dryer pre-cooled to -50 °C, and freeze-dried for 24 h under a pressure of 10 Pa. The dried sample was ground with a grinder and passed through a 125-mesh sieve to obtain the PEG / PVA composite phase change material.
[0042] Preparation of a Pickering emulsion containing natural oils, comprising the following steps:
[0043] A. Add deionized water, glycerol, and the PEG / PVA composite phase change material to a stirring container, and stir at a speed of 150 r / min for 30 min in a constant temperature water bath environment at 25 °C to obtain an aqueous dispersion medium; then pour rosehip oil, jojoba oil, and vitamin E acetate into another stirring container, and stir at a speed of 200 r / min for 1 h in a constant temperature water bath environment at 25 °C to obtain a mixed oil phase.
[0044] B. Slowly pour the mixed oil phase into the aqueous dispersion medium, then add nano-silica, and stir and emulsify at a speed of 800 r / min for 2 h in a constant temperature water bath environment at 50 °C. After emulsification, naturally cool the emulsion to room temperature (25 °C) to obtain the Pickering emulsion containing natural oils.
[0045] Example 2
[0046] A Pickering emulsion containing natural oils and its preparation, wherein the amounts of raw materials required for preparing the Pickering emulsion are shown in Table 2 below:
[0047] Table 2:
[0048]
[0049] The particle size of the nano-silica is 100 nm.
[0050] The preparation of the PEG / PVA composite phase change material is as follows:
[0051] S1, Preparation of PVA solution: Weigh 6 g of PVA powder, add it to 94 g of deionized water, and stir at a speed of 200 r / min for 4 h in a constant temperature water bath at 40 °C until the PVA is completely dissolved to obtain a 6% PVA solution.
[0052] S2, Mixing and defoaming: Add 1.5 g of PEG-800 to the above PVA solution, maintain a 40 °C water bath environment, and stir at a speed of 300 r / min for 3 h. The PEG-800 and the PVA solution are fully mixed, and then the mixed solution is transferred to a vacuum defoamer and defoamed for 30 min under a vacuum degree of -0.1 MPa to remove the bubbles in the solution.
[0053] S3. Freezing and thawing treatment: Pour the defoamed solution into a mold, place it in a freezer at -20 °C and freeze for 12 h. Take out the mold and thaw it naturally at room temperature (25 °C) for 8 h. Repeat the above freezing and thawing process 4 times.
[0054] S4. Drying and pulverizing: Quickly put the sample after freezing and thawing treatment into a freeze dryer pre-cooled to -50 °C, and carry out freeze drying for 24 h under the condition of a pressure of 10 Pa. Pulverize the dried sample with a pulverizer and pass it through a 150-mesh sieve to obtain the PEG / PVA composite phase change material.
[0055] Preparation of a Pickering emulsion containing natural oils, comprising the following steps:
[0056] A. Add deionized water, glycerol and PEG / PVA composite phase change material to a stirring container, and stir at a speed of 150 r / min for 30 min in a constant temperature water bath environment at 25 °C to obtain an aqueous phase dispersion medium; then pour rosehip oil, jojoba oil and vitamin E acetate into another stirring container, and stir at a speed of 200 r / min for 1 h in a constant temperature water bath environment at 25 °C to obtain a mixed oil phase.
[0057] B. Slowly pour the mixed oil phase into the aqueous phase dispersion medium, then add nano-silica, and stir and emulsify at a speed of 800 r / min for 2 h in a constant temperature water bath environment at 50 °C. After the emulsification is completed, naturally cool the emulsion to room temperature (25 °C) to obtain a Pickering emulsion containing natural oils.
[0058] Example 3
[0059] A Pickering emulsion containing natural oils and its preparation, wherein the amounts of raw materials required for the preparation of the Pickering emulsion are shown in Table 3 below:
[0060] Table 3:
[0061]
[0062]
[0063] The particle size of nano-silica is 80 nm.
[0064] The preparation of the PEG / PVA composite phase change material is specifically as follows:
[0065] S1. Preparation of PVA solution: Weigh 7 g of PVA powder, add it to 93 g of deionized water, and stir at a speed of 200 r / min for 4 h in a constant temperature water bath at 40 °C until the PVA is completely dissolved to obtain a 7% PVA solution.
[0066] S2, Mixing and degassing: Add 2.1 g of PEG-800 to the above PVA solution, maintain a water bath environment at 40 °C, stir at a speed of 300 r / min for 3 h, so that PEG-800 is fully mixed with the PVA solution. Then transfer the mixed solution to a vacuum degassing machine and degas for 30 min under a vacuum degree of -0.1 MPa to remove the bubbles in the solution.
[0067] S3, Freezing and thawing treatment: Pour the degassed solution into a mold, place it in a freezer at -25 °C and freeze for 12 h. Take out the mold and thaw naturally at room temperature (25 °C) for 8 h. Repeat the above freezing and thawing process 4 times.
[0068] S4, Drying and pulverizing: Quickly put the sample after freezing and thawing treatment into a freeze dryer pre-cooled to -50 °C, carry out freeze drying for 24 h under a pressure of 10 Pa. Pulverize the dried sample with a pulverizer and pass through a 200-mesh sieve to obtain the PEG / PVA composite phase change material.
[0069] Preparation of a Pickering emulsion containing natural oils, comprising the following steps:
[0070] A. Add deionized water, glycerol and the PEG / PVA composite phase change material to a stirring container, and stir at a speed of 150 r / min for 30 min in a constant temperature water bath environment at 25 °C to obtain an aqueous dispersion medium; then pour rosehip oil, jojoba oil and vitamin E acetate into another stirring container, and stir at a speed of 200 r / min for 1 h in a constant temperature water bath environment at 25 °C to obtain a mixed oil phase.
[0071] B. Slowly pour the mixed oil phase into the aqueous dispersion medium, then add nano-silica, and stir and emulsify at a speed of 800 r / min for 2 h in a constant temperature water bath environment at 50 °C. After emulsification is completed, naturally cool the emulsion to room temperature (25 °C) to obtain a Pickering emulsion containing natural oils.
[0072] Example 4
[0073] Based on Example 1, omit jojoba oil and change the mass of rosehip oil to 35 g.
[0074] Example 5
[0075] Based on Example 1, change silica to montmorillonite with an equal amount, and the particle size of montmorillonite is 150 nm.
[0076] Comparative Example 1
[0077] The difference from Example 1 is that: do not add the PEG / PVA composite phase change material.
[0078] Test Example 1
[0079] The PEG / PVA composite phase change materials prepared in Examples 1-3 were subjected to DSC tests, and the results are shown in Table 4.
[0080] Table 4:
[0081] Group Phase change start temperature (°C) Phase change peak temperature (°C) Phase change enthalpy (J / g) Example 1 23.5 25.9 68.3 Example 2 24.8 27.1 89.7 Example 3 26.2 28.5 112.4
[0082] It can be seen from the data in Table 4 that the phase change start temperature and phase change peak temperature of the PEG / PVA composite phase change materials prepared in Examples 1, 2, and 3 are all within the target phase change temperature range of 23-32 °C, and the phase change enthalpy values reach 68.3 J / g, 89.7 J / g, and 112.4 J / g respectively, indicating that the composite phase change material has stable phase change temperature control ability.
[0083] Test Example 2
[0084] 20 g of the Pickering emulsion samples prepared in Examples 1-5 and Comparative Example 1 were respectively filled into brown glass bottles, sealed, and placed in a constant temperature oven for temperature cycle tests. The temperature cycle was set as follows: after maintaining at 25 °C for 12 hours, the temperature was increased to 35 °C at a gradient of 10 °C / h and maintained for 12 h, and then the temperature was decreased to 25 °C at a gradient of 10 °C / h to complete a full cycle. After every 10 cycles, 1 g of the emulsion was taken from each sample, and the linolenic acid content was determined by high performance liquid chromatography, and the retention rate relative to the initial value was calculated, and 30 cycles were continuously monitored.
[0085] The results are shown in Table 5
[0086] Table 5
[0087]
[0088]
[0089] The data in Table 5 show that after 30 temperature cycles, the linolenic acid retention rates of Examples 1-5 are 78.6%, 82.5%, 86.9%, 71.8%, and 76.5% respectively, which are significantly higher than 48.3% of Comparative Example 1. This indicates that the PEG / PVA composite phase change material can effectively inhibit the oxidative degradation of linolenic acid at room temperature through phase change heat absorption.
[0090] Test Example 3
[0091] The PEG / PVA composite phase change materials prepared in Examples 1-3 were taken and placed in a constant temperature oven. After being kept at 50 °C for 12 hours, the sample state was observed, and then the state was observed again after gently pressing with a steel spoon. The results are shown in Table 6.
[0092] Table 6:
[0093] Group Sample state Example 1 Solid state, no oil oozes out under light pressure Example 2 Solid state, no oil oozes out under light pressure Example 3 Solid state, no oil oozes out under light pressure
[0094] The results in Table 6 show that the PEG / PVA composite phase change materials prepared in all examples remained solid after being kept at a constant temperature of 50 °C for 12 hours, and no oil oozed out under light pressure, indicating that the PEG / PVA composite phase change materials remained solid during the phase change process, avoiding the demulsification of the emulsion caused by the oozing out of the liquid oil phase.
[0095] As described above, it is only the preferred embodiments of the present invention, and there is no any form of limitation to the present invention. Although the present invention has been disclosed as above with the preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments by using the disclosed technical content within the scope of the technical solution of the present invention. However, as long as it does not depart from the content of the technical solution of the present invention, any brief modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention still fall within the scope of the technical solution of the present invention.
Claims
1. A Pickering emulsion containing natural oils, characterized in that, The latex particles are formed by a plurality of latex particles in a stable dispersed state, wherein the latex particles are formed by an oil phase material, a water phase material encapsulating the oil phase material, and a Pickering stabilizer providing a stabilizing effect between the interfaces of the oil phase material and the water phase material; The water phase material is formed by dispersing a phase change material in a water phase medium, the phase change material is defined as a material with a phase change temperature of 23-32° C., and the oil phase material contains at least rosehip oil.
2. The Pickering emulsion containing natural oil according to claim 1, characterized in that, The phase change material is a PEG / PVA composite phase change material.
3. A Pickering emulsion containing natural oils according to claim 2, characterized in that, The weight portion of the PEG / PVA composite phase change material is 3-5 parts. The raw materials of the PEG / PVA composite phase change material include PEG-800 and PVA. The mass ratio of the PEG-800 to PVA is (2-3):
10.
4. A Pickering emulsion containing natural oils according to claim 3, characterized in that, The preparation process of the PEG / PVA composite phase change material comprises the following steps: Dispersing PVA in water to form a PVA solution, adding PEG-800 to the PVA solution; The PEG-800 and the PVA solution are subjected to at least one freeze-thaw operation to obtain a PEG / PVA composite phase change material, wherein the freeze-thaw operation includes first freezing and then thawing.
5. A Pickering emulsion containing natural oils according to claim 4, characterized in that, The freezing temperature in the freeze-thaw operation is -25-15°C.
6. The Pickering emulsion containing natural oil according to claim 4, wherein The concentration of the PVA solution is 6-8 wt %.
7. A Pickering emulsion containing natural oil according to claim 3, wherein, The particle size of the PEG / PVA composite phase change material is 100-200 meshes.
8. A Pickering emulsion containing natural oil according to claim 1, characterized in that, The oil phase material comprises the following components in parts by weight: 15-25 parts of rosehip oil, 9-10 parts of jojoba oil and 0.5-1.5 parts of vitamin E acetate.
9. A Pickering emulsion containing natural oils according to claim 1, characterized in that The water phase material comprises the following components in parts by weight: 135-145 parts of water, 10-15 parts of glycerin and 1-2 parts of yeast / Aspergillus / rice / Opuntia cactus stem fermentation product filtrate.
10. Preparation of a Pickering emulsion containing natural oil according to any one of claims 1-9, characterized in that, The following steps are involved: A. mixing a phase change material with an aqueous phase material to obtain an aqueous phase dispersion medium; B. Mix the oil phase material with the aqueous dispersion medium, then add the Pickering stabilizer, fully disperse and emulsify to obtain the Pickering emulsion.