Freeze-dried film cloth and preparation process thereof

Abstract

The invention relates to the technical field of masks, and discloses a freeze-dried mask cloth and a preparation process thereof.The freeze-dried mask cloth comprises a mask cloth body, eye through holes used for eye observation, a nose through hole used for a nose to breathe and a mouth through hole used for a mouth to pass are formed in the surface of the mask cloth body, and the edge of the mask cloth body is provided with an extending bonding part used for being attached to the cheek side; the extension bonding part is obtained by extending from the bottom of the mask cloth to two sides; the mask cloth is composed of a base layer, a medicine storage layer, an active water permeable layer and an anti-oxidation layer, the four constituent layers are evenly stacked from inside to outside to form a mask cloth body, and the base layer is attached to the face. The substrate layer is composed of the modified alginate fiber and the silk protein compound, and a high-water-locking fiber network is formed through wet spinning; the porous structure of the active permeable layer ensures the air permeability. According to the laboratory standard test of the company, the air permeability is remarkably improved compared with that of a traditional silk mask, and the problem of skin stuffiness caused by a hydrogel mask is thoroughly solved.

Description

Technical Field

[0001] This invention relates to the field of facial mask processing, and more particularly to a freeze-dried mask fabric and its preparation process. Background Technology

[0002] Facial masks are a type of cosmetic. In recent years, freeze-dried facial masks have gradually become a research hotspot in the skincare field due to their advantages such as effectively preserving active ingredients, extending shelf life, and facilitating transportation. Traditional facial masks mostly use non-woven fabrics, silk, or gel materials, and their active ingredients are usually attached to the surface of the substrate in liquid form.

[0003] Most existing facial mask sheets are single-layered or simply double-layered, which cannot simultaneously meet the needs of water retention, breathability, and targeted release of active ingredients. For example, while silk masks are skin-friendly, they have weak water retention capabilities; while highly water-retaining materials (such as hydrogels) have poor breathability, which can easily cause stuffiness and discomfort on the skin.

[0004] To address the aforementioned issues, some improvement solutions attempt to optimize performance through multi-layer structures or surface coatings, but limitations remain. For example, patent publication number CN1216917A proposes a peel-off mask, but its coating is prone to peeling off and hinders the release of active ingredients; based on this, we propose a freeze-dried membrane fabric and its preparation process. Summary of the Invention

[0005] To address the technical problem that existing face masks cannot simultaneously achieve both water retention and targeted release of active ingredients, this invention provides a freeze-dried mask sheet and its preparation process.

[0006] The present invention is achieved by the following technical solution: a freeze-dried membrane cloth, including a mask cloth, the surface of which is provided with an eye opening for observation, a nasal opening for breathing through the nose, and a mouth opening for breathing through the mouth, and the edge of the mask cloth is provided with an extended adhesive portion for adhering to the cheeks, the extended adhesive portion being obtained by extending from the bottom of the mask cloth to both sides.

[0007] The mask sheet consists of a base layer, a drug storage layer, an active water-permeable layer, and an antioxidant layer. These four layers are stacked evenly from the inside out to form the mask sheet body, with the base layer adhering to the face.

[0008] The process for preparing freeze-dried membrane fabric includes the following steps:

[0009] S1: Base layer preparation: Modified seaweed fiber and silk protein are mixed in a weight ratio of 4:1, and a fiber web is formed by wet spinning. The base layer is then obtained by hot air drying.

[0010] S2: Drug storage layer loading: Microcapsules are prepared by mixing at least one active ingredient among collagen, hyaluronic acid or vitamin C derivative with a lyophilization protectant and then preparing them by spray drying. The resulting microcapsules have a particle size of 1-10 μm and are uniformly dispersed in the drug storage layer.

[0011] S3: Forming of active permeable layer: A cross-linked polyacrylate solution is coated onto the surface of the drug storage layer. Before coating the drug storage layer with the cross-linked polyacrylate solution, the surface of the drug storage layer needs to be plasma treated to improve the adhesion between the coating and the drug storage layer. Then, it is cured by ultraviolet light. Under nitrogen protection, an active permeable layer with a pore size of 0.1-5μm is formed by ultraviolet light curing.

[0012] S4: Antioxidant layer treatment: Spray nano-titanium dioxide or tea polyphenol solution onto the surface of the active permeable layer, spraying 3-5 times; dry at 40-60℃ for 1-2 hours to form an antioxidant layer with a thickness of 10-50nm;

[0013] S5: Freeze-drying process: The composite mask fabric undergoes gradient freeze-drying treatment, including:

[0014] Pre-freezing stage: Rapid freezing at -40℃ for 2-4 hours;

[0015] Main drying stage: vacuum degree ≤10Pa, temperature is increased to 25℃ in stages, total drying time is 18-24 hours. After each stage of temperature increase, the moisture content is monitored by mass spectrometry to ensure that the residual moisture content is ≤3%.

[0016] As a further optimization of the present invention, the substrate layer is made of a modified seaweed fiber and silk protein complex, with a fiber diameter of 10-50 μm.

[0017] As a further optimization of the present invention, the drug storage layer contains a freeze-dried active ingredient, which is at least one of collagen, hyaluronic acid or vitamin C derivative, and is uniformly distributed in the drug storage layer in the form of microcapsules.

[0018] As a further optimization of this invention, a gradient freeze-drying process (including a pre-freezing stage and a main drying stage) is used to slowly remove moisture under vacuum and low temperature conditions, preventing the active ingredients from degrading due to high temperatures or liquid residues. During the freeze-drying process, a mass spectrometer monitors the moisture content in real time (≤3%), and an infrared thermal imager ensures temperature uniformity (temperature difference ±2℃), ultimately achieving an active ingredient retention rate of ≥95%. A secondary sterilization treatment after freeze-drying (ethylene oxide sterilization) further ensures the sterility of the product and extends its shelf life.

[0019] As a further optimization of the present invention, during application, the moisture and slightly acidic environment on the skin surface trigger the pH-responsive release of the drug-storing microcapsules, allowing the active ingredients to gradually penetrate into the skin through the pore size regulation of the active permeable layer. Simultaneously, the synergistic effect of the basal layer and the active permeable layer maintains the breathability of the membrane, avoiding skin discomfort caused by excessive occlusion in traditional masks.

[0020] As a further optimization of the present invention, the base layer is composed of a modified seaweed fiber and silk protein complex, with a fiber diameter of 10-50 μm. This layer directly adheres to the face, providing a flexible and skin-friendly feel, while enhancing water retention capacity through a fiber network formed by wet spinning.

[0021] As a further optimization of the present invention, the drug storage layer contains freeze-dried active ingredients (such as collagen, hyaluronic acid or vitamin C derivatives) and is uniformly distributed in the form of microcapsules; the surface of the microcapsules is coated with a pH-responsive chitosan coating, which gradually dissolves when in contact with the weakly acidic environment of the skin surface, thereby achieving the targeted release of the active ingredients.

[0022] As a further optimization of the present invention, the active water-permeable layer is made of cross-linked polyacrylate with a pore size of 0.1-5 μm. This layer enhances its adhesion to the drug storage layer through plasma treatment, and its porous structure can both control the rate of water evaporation and allow the active ingredients to penetrate into the skin in a controlled manner.

[0023] As a further optimization of the present invention, the antioxidant layer is formed by spraying nano-titanium dioxide or tea polyphenol solution, with a thickness of 10-50 nm. This layer prevents the active ingredients from oxidizing and becoming inactive during storage or use through a dual mechanism of physical barrier and chemical antioxidation.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] 1. This invention utilizes a gradient freeze-drying process (rapid freezing at -40℃ during the pre-freezing stage and vacuum ≤10Pa during the main drying stage), combined with real-time monitoring of moisture content by mass spectrometry and control of temperature uniformity by infrared thermal imaging, to achieve a preservation rate of ≥96% for active ingredients such as collagen and hyaluronic acid. Compared with the traditional hot air drying process (preservation rate ≤77%), this effectively avoids the problem of high-temperature degradation and significantly extends the shelf life of the product.

[0026] 2. This invention uses pH-responsive chitosan-coated microcapsules in the drug storage layer, which gradually dissolve when in contact with the weakly acidic environment of the skin, thus achieving on-demand release of active ingredients; at the same time, the active permeable layer enhances adhesion through plasma treatment, precisely controlling the release rate.

[0027] 3. This invention utilizes a base layer composed of a modified seaweed fiber and silk protein complex, formed through wet spinning to create a highly water-locking fiber network; the porous structure of the active water-permeable layer ensures breathability. According to our laboratory standard tests, the breathability is significantly improved compared to traditional silk masks, completely solving the skin stuffiness problem caused by hydrogel masks. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0029] Figure 2 This is a schematic diagram of the planar structure of the present invention;

[0030] Figure 3 This is a schematic diagram of the base layer structure of the mask fabric of the present invention.

[0031] Explanation of key symbols:

[0032] 1. Mask sheet; 2. Eye openings; 3. Nose openings; 4. Mouth openings; 5. Extension adhesive layer; 6. Base layer; 7. Drug storage layer; 8. Active water-permeable layer; 9. Antioxidant layer. Detailed Implementation

[0033] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments. It should be noted that, without conflict, the various embodiments or technical features described below can be arbitrarily combined to form new embodiments.

[0034] Example 1:

[0035] Please combine Figures 1-3 This embodiment proposes a freeze-dried membrane cloth, including a mask cloth 1. The surface of the mask cloth 1 is provided with an eye opening 2 for observation, a nose opening 3 for breathing through the nose, and a mouth opening 4 for breathing through the mouth. The edge of the mask cloth 1 is provided with an extended adhesive part (5) for adhering to the cheeks. The extended adhesive part (5) extends from the bottom of the mask cloth 1 to both sides.

[0036] The mask sheet 1 is composed of a base layer 6, a drug storage layer 7, an active water-permeable layer 8, and an antioxidant layer 9. The four constituent layers are stacked evenly from the inside to the outside to form the mask sheet 1 body, and the base layer 6 is attached to the face.

[0037] It should be noted that the base layer 6 is made of a modified seaweed fiber and silk protein complex, with a fiber diameter of 10-50 μm.

[0038] Furthermore, the drug storage layer 7 contains a freeze-dried active ingredient, which is at least one of collagen, hyaluronic acid, or vitamin C derivative, and is uniformly distributed in the drug storage layer 7 in the form of microcapsules.

[0039] Example 2:

[0040] This embodiment provides a process for preparing the freeze-dried membrane fabric in Example 1. The freeze-dried membrane fabric preparation process includes the following steps:

[0041] S1: Base layer preparation: Modified seaweed fiber and silk protein were mixed in a weight ratio of 4:1, and a fiber web was formed by wet spinning. The base layer was then dried by hot air (6).

[0042] S2: Drug storage layer loading: Microcapsules are prepared by mixing at least one active ingredient from collagen, hyaluronic acid or vitamin C derivative with a lyophilization protectant and then spray drying. The resulting microcapsules have a particle size of 1-10 μm and are uniformly dispersed in the drug storage layer (7).

[0043] It should be noted that in step S2:

[0044] The surface of the microcapsules is coated with a pH-responsive chitosan coating with a thickness of 0.1-0.5 μm. During the spray drying process, the atomizer uses a dual-fluid nozzle with a gas to liquid flow ratio of 3:1.

[0045] S3: Forming of active permeable layer: The cross-linked polyacrylate solution is coated on the surface of the drug storage layer. Before coating the cross-linked polyacrylate solution, the surface of the drug storage layer (7) needs to be plasma treated to improve the adhesion between the coating and the drug storage layer. Then, it is cured by ultraviolet light. Under nitrogen protection, an active permeable layer (8) with a pore size of 0.1-5μm is formed by ultraviolet light curing.

[0046] S4: Antioxidant layer treatment: Spray nano-titanium dioxide or tea polyphenol solution onto the surface of the active permeable layer (8) 3-5 times; dry at 40-60℃ for 1-2 hours to form an antioxidant layer (9) with a thickness of 10-50nm;

[0047] More specific experimental analysis: The laboratory conducted tests on antioxidant performance, mainly focusing on the DPPH free radical scavenging rate (antioxidant rate refers to the efficiency of a substance in scavenging free radicals, usually determined experimentally; for example, a substance with a DPPH scavenging rate of 90% indicates that it can neutralize 90% of free radicals), and obtained the following data:

[0048] Antioxidant performance test (DPPH free radical scavenging rate)

[0049] Antioxidant layer type Clearance rate (%) Nano titanium dioxide 89.4±1.1 Tea polyphenol solution 92.7±0.8 No antioxidant layer 23.5±2.3

[0050] Based on the above data, it can be seen that the antioxidant layer (10-50nm) used in this patent significantly enhances the free radical scavenging ability and protects the active ingredients from oxidative deactivation.

[0051] S5: Freeze-drying process: The composite structure mask fabric (1) undergoes gradient freeze-drying treatment, including:

[0052] Pre-freezing stage: Rapid freezing at -40℃ for 2-4 hours;

[0053] Main drying stage: vacuum degree ≤10Pa, temperature is increased to 25℃ in stages, total drying time is 18-24 hours. After each stage of temperature increase, the moisture content is monitored by mass spectrometry to ensure that the residual moisture content is ≤3%.

[0054] Furthermore, in step S5:

[0055] After each stage of heating, the surface temperature uniformity of the mask cloth is detected by infrared thermal imaging, and the temperature difference is within ±2℃. After freeze-drying, the moisture content of the mask cloth (1) is ≤3%, and the retention rate of active ingredients is ≥95%.

[0056] Furthermore, in step S5:

[0057] After freeze-drying, the mask sheet needs to undergo secondary sterilization to ensure the product's sterility. The secondary sterilization process uses ethylene oxide sterilization at a temperature of 50-60℃ for 4-6 hours. After sterilization, thorough ventilation is required to remove any residual ethylene oxide.

[0058] Comparison of active ingredient retention rates (freeze-drying vs. traditional hot air drying)

[0059] Active ingredients Preservation rate of freeze-drying process (%) Traditional hot air drying preservation rate (%) Collagen 97.2±0.5 76.4±1.2 Hyaluronic acid 96.8±0.3 66.9±2.1 Vitamin C derivatives 97.5±0.7 64.3±1.8

[0060] Based on the above data analysis and comparison, it can be seen that the freeze-drying process effectively avoids the thermal degradation of active ingredients under low temperature and vacuum conditions, and the preservation rate is significantly higher than that of traditional methods.

[0061] According to laboratory test data from our company, the breathability test data of the freeze-dried membrane fabric of this invention compared with those of traditional silk masks and hydrogel masks mentioned in the background art are as follows:

[0062] Material type <![CDATA[Air permeability (cm 3 / cm 2 / s))]]> The freeze-dried membrane of the present invention 15.6±0.8 Traditional silk masks 8.2±0.5 Hydrogel mask 2.1±0.3

[0063] Based on the above data analysis, it can be seen that the synergistic effect of the active permeable layer 8 (pore size 0.1-5μm) and the base layer 6 makes the breathability better than traditional materials, thus avoiding skin stuffiness.

[0064] The freeze-dried membrane fabric of the present invention achieves efficient preservation, targeted release and synergistic enhancement of skin permeability of active ingredients through a multi-layer composite structure and optimized preparation process;

[0065] Base layer: Composed of a modified seaweed fiber and silk protein complex, with fiber diameters of 10-50 μm. This layer adheres directly to the face, providing a soft and skin-friendly feel, while the fiber network formed by wet spinning enhances water retention.

[0066] Drug reservoir: Contains lyophilized active ingredients (such as collagen, hyaluronic acid or vitamin C derivatives) uniformly distributed in the form of microcapsules; the surface of the microcapsules is coated with a pH-responsive chitosan coating, which gradually dissolves when in contact with the weakly acidic environment of the skin surface, thereby achieving the targeted release of active ingredients.

[0067] Active water-permeable layer: made of cross-linked polyacrylate with a pore size of 0.1-5 μm. This layer enhances its adhesion to the drug storage layer through plasma treatment. Its porous structure controls the rate of water evaporation while allowing active ingredients to penetrate the skin in a controlled manner.

[0068] Antioxidant layer: Formed by spraying nano-titanium dioxide or tea polyphenol solution, with a thickness of 10-50nm. This layer prevents the active ingredients from oxidizing and becoming inactive during storage or use through a dual mechanism of physical barrier and chemical antioxidation.

[0069] The active preservation mechanism of freeze-drying process

[0070] A gradient freeze-drying process (including a pre-freezing stage and a main drying stage) is used to slowly remove moisture under vacuum and low temperature conditions, preventing degradation of active ingredients due to high temperatures or liquid residues. During the freeze-drying process, mass spectrometry monitors the moisture content in real time (≤3%), and infrared thermal imaging ensures temperature uniformity (temperature difference ±2℃), ultimately achieving an active ingredient retention rate of ≥95%. A secondary sterilization treatment after freeze-drying (ethylene oxide sterilization) further ensures the product's sterility and extends its shelf life.

[0071] Dynamic release and breathability balance

[0072] During application, the moisture and slightly acidic environment on the skin surface trigger the pH-responsive release of the drug-storing microcapsules, allowing the active ingredients to gradually penetrate the skin through the pore size regulation of the active permeable layer. Simultaneously, the synergistic effect of the basal layer and the active permeable layer maintains the breathability of the membrane, avoiding skin discomfort caused by excessive occlusion in traditional masks.

[0073] In summary, this invention, through structural innovation and process optimization, solves the pain point of traditional face masks in that it is difficult to balance water retention, breathability, and preservation of active ingredients, thus achieving a balance between efficient skincare and user experience.

[0074] The above embodiments are merely preferred embodiments of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-substantial changes and substitutions made by those skilled in the art based on the present invention shall fall within the scope of protection claimed by the present invention.

Claims

1. A lyophilized film dressing, characterized in that, The application relates to a mask cloth (1) which is provided with an eye through hole (2) for eye observation, a nose through hole (3) for nose breathing and a mouth through hole (4) for mouth passing, and the edge of the mask cloth (1) is provided with an extended adhesive part (5) for adhering the cheek. The mask cloth (1) is composed of a base layer (6), a medicine storage layer (7), an active water permeable layer (8) and an antioxidant layer (9), and the four layers are uniformly stacked from inside to outside to form the mask cloth (1) body.

2. A lyophilized film dressing according to claim 1, wherein, The base layer (6) is made of a modified seaweed fiber and silk protein compound, and the fiber diameter is 10-50 mu m.

3. A lyophilized film dressing according to claim 1, wherein, The medicine storage layer (7) contains freeze-dried active ingredients, and the active ingredients are at least one of collagen, hyaluronic acid or vitamin C derivatives, and are uniformly distributed in the medicine storage layer (7) in the form of microcapsules.

4. The lyophilized film dressing of claim 1, wherein, The pore size of the active water permeable layer (8) is 0.1-5 mu m, and the material of the active water permeable layer (8) is cross-linked polyacrylate.

5. A process for the preparation of a lyophilized film fabric for use in a lyophilized film fabric according to any one of claims 1 to 4, characterized in that The preparation process of the freeze-dried mask cloth comprises the following steps: S1: base layer preparation: mixing modified seaweed fiber and silk protein at a weight ratio of 4:1, forming a fiber web through wet spinning, and then drying through hot air to obtain the base layer (6); S2: medicine storage layer loading: mixing at least one active ingredient of collagen, hyaluronic acid or vitamin C derivative with a freeze-drying protective agent, preparing microcapsules by spray drying, and uniformly dispersing the obtained microcapsules with a particle size of 1-10 mu m in the medicine storage layer (7); S3: active water permeable layer forming: coating a cross-linked polyacrylate solution on the surface of the medicine storage layer, and before coating the cross-linked polyacrylate solution, the surface of the medicine storage layer (7) needs to be subjected to plasma treatment to improve the adhesion between the coating and the medicine storage layer; then, ultraviolet light is used for curing, and the active water permeable layer (8) with a pore size of 0.1-5 mu m is formed under the protection of nitrogen by ultraviolet light curing; S4: antioxidant layer treatment: spraying a nano titanium dioxide or tea polyphenol solution on the surface of the active water permeable layer (8), and the spraying frequency is 3-5 times; drying at 40-60 DEG C for 1-2 hours to form an antioxidant layer (9) with a thickness of 10-50 nm; S5: freeze-drying process: gradient freeze-drying treatment is conducted on the mask cloth (1) with a composite structure, which comprises the following steps: Pre-freezing stage: rapid freezing at -40 DEG C for 2-4 hours; Main drying stage: the vacuum degree is less than or equal to 10 Pa, the temperature is gradually increased to 25 DEG C, the total drying time is 18-24 hours, the water content is monitored by a mass spectrometer after the temperature is increased at each stage, and the residual water content is less than or equal to 3%.

6. The process for preparing a lyophilized film dressing according to claim 5, wherein, In the step S2: The surface of the microcapsule is coated with a pH-responsive chitosan coating with a thickness of 0.1-0.5 mu m, and a double-fluid nozzle is used for atomization during the spray drying process, and the flow ratio of gas to liquid is 3:

1.

7. The process for preparing a lyophilized film dressing according to claim 5, wherein, In the step S5: After each stage of temperature rise, the surface temperature uniformity of the mask cloth is detected by an infrared thermal imager, and the temperature difference is within the range of ±2℃; after freeze-drying is completed, the water content of the mask cloth (1) is ≤3%, and the active ingredient preservation rate is ≥95%.

8. The process for preparing a lyophilized film dressing according to claim 5, wherein, In the step S5: After freeze-drying is completed, secondary sterilization treatment of the mask cloth is further needed to ensure the sterile state of the product; the secondary sterilization treatment adopts an ethylene oxide sterilization method, the sterilization temperature is 50-60℃, the sterilization time is 4-6 hours, and after sterilization, sufficient ventilation treatment is needed to remove residual ethylene oxide.

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