Sunscreen scar patch and preparation method thereof

Abstract

The embodiment of the invention discloses a sunscreen scar patch and a preparation method, and relates to the technical field of medicines.The method comprises the steps that by means of the synergistic interaction effect of a triazine ultraviolet absorbent and a light stabilizer, ultraviolet rays with the wave band of 290-400 nm can be fixedly absorbed, the UPF value is larger than 50, non-woven fabric is adopted as a supporting layer, the stability and strength of the scar patch are improved, and the sunscreen scar patch is suitable for being used as a sunscreen scar patch. The wearing comfort is improved, the ultraviolet absorbent and the light stabilizer are not in direct contact with the skin, so that possible skin irritation or anaphylactic reaction is avoided, the color change caused by oxidation of the material is effectively avoided by adding the light stabilizer, and the color is still stable after long-time use or high-temperature accelerated aging; the problems that in the prior art, silica gel is prone to falling off, and the edge of a scar patch is prone to curling are solved, and therefore the problems that in the prior art, the sunscreen capacity is poor, and the comfort degree is poor can be effectively solved.

Description

Technical Field

[0001] The invention relates to the field of medical technology, and in particular to a sunscreen scar patch and a preparation method thereof. Background Art

[0002] The skin during scar repair is very delicate. Scars are different from normal skin. The skin barrier function is incomplete and more susceptible to ultraviolet damage. Long-term exposure to ultraviolet rays will cause melanin deposition, stimulate scar hyperplasia, affect the effect of scar repair treatment, and may also cause keloids. Most sunscreens contain ingredients that may irritate the repairing skin and cause allergies, increasing the risk of infection. Early exposure of scars to ultraviolet rays will significantly increase pigmentation. Some domestic and foreign scar prevention and treatment guidelines, such as the 2014 "Eur J Dermatol" guidelines, the 2014 "J Plast Reconstr Aesthet Surg" guidelines, and the 2017 "Chinese Clinical Scar Prevention Expert Consensus", also recommend sun protection as one of the early scar care methods.

[0003] However, most scar patches prepared by existing technologies do not have sun protection function, cannot effectively cover exposed scars, cannot resist ultraviolet rays and stimulate abnormal secretion of melanocytes, stimulate local capillary dilation, cause scars to darken, and cannot meet the needs of patients.

[0004] In the existing technology, some are made by attaching nano-silver particles and UV blockers titanium dioxide, zinc oxide, hydrogenated nano-level titanium dioxide and nano-silver to a silicone mesh, but the UPF is lower than 30 and the sun protection ability is poor; some are made of TPU film, anti-UV layer, elastic layer, waterproof layer and wear-resistant coating, which are made by heating and pressurizing. The thickness of the anti-UV layer is too thick, and the softness and comfort are poor.

[0005] Therefore, there is an urgent need for a sunscreen scar patch and a preparation method that can significantly improve the sunscreen effect, solve problems such as easy glue falling off and easy curling, improve wearing comfort and safety, and meet the aesthetic needs of patients. Summary of the invention

[0006] Each embodiment of the present invention provides a sunscreen scar patch and a preparation method to solve the problem that the sunscreen scar patch prepared by the prior art has poor sunscreen ability and poor comfort. The technical solution is as follows:

[0007] According to one aspect of the present invention, a sunscreen scar patch comprises a sunscreen polyurethane film, non-woven fabric, two-component silicone gel and a release film; the sunscreen polyurethane film comprises an ultraviolet absorber and a light stabilizer; the thickness of the sunscreen polyurethane film is 10-80 μm; the thickness of the release film is 0.1-5 mm.

[0008] In one embodiment, the non-woven fabric includes pure cotton non-woven fabric, polyester-viscose non-woven fabric and polyester non-woven fabric.

[0009] In one embodiment, the material of the release film includes PC, PP, PET, PE and a composite material of PET / PE.

[0010] In one embodiment, the nonwoven fabric has a grammage of 8-50 g / m 2 The nonwoven fabric has a radial strength greater than 20N / 5cm and a transverse strength greater than 10N / 5cm.

[0011] According to one aspect of the present invention, a method for preparing a sunscreen scar patch comprises: after evenly dispersing an ultraviolet absorber and a light stabilizer with a solvent, adding the dispersed ultraviolet absorber and a light stabilizer to a polyurethane base material, stirring the dispersed ultraviolet absorber and a light stabilizer to form a liquid, adding a skin color paste and mixing the dispersed ultraviolet absorber and a light stabilizer to form a mixed liquid, pouring the mixed liquid on a coating machine and adjusting the thickness to 10-80 μm, heating and drying the mixed liquid, and rolling the mixed liquid to form a sunscreen polyurethane film; using glue to compound the sunscreen polyurethane film with a non-woven fabric to form a composite material; the glue is a single-component acrylic oil glue; the non-woven fabric comprises a pure cotton non-woven fabric, a polyester-viscosity non-woven fabric, and a polyester non-woven fabric; the gram weight of the non-woven fabric is 8-50 g / m 2 , radial strength greater than 20N / 5cm, lateral strength greater than 10N / 5cm; place the composite material on a coating machine, pour in the mixed two-component silicone gel and adjust the coating weight to 50-1000g / m 2 , heat and cure at 50-150° C. for 10-60 minutes, and attach a release film to obtain a sunscreen scar sticker; the material of the release film includes PC, PP, PET, PE and a composite material of PET / PE; the thickness of the release film is 0.1-5 mm.

[0012] In one embodiment, the ultraviolet absorber is a triazine ultraviolet absorber BASF Tinuvin234.

[0013] In one embodiment, the light stabilizer is RIASORB UV-944.

[0014] In one embodiment, the solvent is dimethylformamide.

[0015] In one embodiment, the skin color paste has a color difference value of 0-1dE Full Shade, a fineness of 0m-50m, and a non-volatile matter content of 98-100%.

[0016] In one embodiment, the viscosity of the polyurethane base material is 10,000 mPa.S-20,000 mPa.S, the non-volatile matter content is 29-32%, and the chromaticity is <300.

[0017] The beneficial effects brought by the technical solution provided by the present invention are:

[0018] In the above technical scheme, the present invention adopts triazine ultraviolet absorber BASF Tinuvin 234 and light stabilizer RIASORB UV-944, and through synergistic effect, it can fix and absorb ultraviolet rays in the 290nm-400nm band, and the UPF value is greater than 50. Non-woven fabric is used as the supporting layer, which increases the stability and strength of the scar patch and improves the wearing comfort. The ultraviolet absorber and light stabilizer do not directly contact the skin, thereby avoiding possible skin irritation or allergic reactions. The color change of the material caused by oxidation is effectively avoided by adding a light stabilizer. After long-term use or high-temperature accelerated aging, the color remains stable, which meets the aesthetic needs of patients, and solves the problems of easy debonding of silicone and easy curling of scar patches in the prior art, thereby effectively solving the problems of poor sun protection ability and poor comfort in the prior art. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in describing the embodiments of the present invention. Obviously, the drawings described below are only some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without creative work.

[0020] Figure 1 is a flow chart of a method for preparing a sunscreen scar patch according to an exemplary embodiment;

[0021] Figure 2 yes Figure 1 A schematic diagram of the structure of the sunscreen scar patch in the corresponding embodiment;

[0022] Figure 3 yes Figure 1 Schematic diagram of the test results of the sunscreen scar patch in the corresponding embodiment;

[0023] Figure 4 yes Figure 1 The effect diagram of the sunscreen scar patch in the corresponding embodiment. DETAILED DESCRIPTION

[0024] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention.

[0025] The present invention provides a sunscreen scar patch and a preparation method thereof. By adopting a specific ultraviolet absorber, a light stabilizer, a non-woven fabric support layer, and a reasonable structural design, the sunscreen effect is significantly improved, the problem of easy glue falling and curling is solved, the use safety is improved, and the color is stable. The sunscreen scar patch preparation method is suitable for the preparation of the sunscreen scar patch. The sunscreen scar patch and the preparation method in the embodiment of the present invention can be applied to a variety of scenarios, such as scar repair.

[0026] See also Figure 1 , an embodiment of the present invention provides a method for preparing a sunscreen scar patch.

[0027] like Figure 1 As shown, the method may include the following steps:

[0028] Step 110, after the ultraviolet absorber and light stabilizer are dispersed evenly with a solvent, they are added to the polyurethane base material and stirred into a liquid, and then the skin color paste is added and mixed evenly to obtain a mixed liquid, and the mixed liquid is poured on a coating machine and the thickness is adjusted to 10-80 μm, and then heated and dried and rolled up to obtain a sunscreen polyurethane film.

[0029] In a possible implementation, the ultraviolet absorber is a triazine ultraviolet absorber BASF Tinuvin 234. The triazine ultraviolet absorber BASF Tinuvin 234 has good compatibility with the polyurethane base material and strong light absorption. It absorbs ultraviolet rays in the wavelength band of 290-400nm and converts the absorbed ultraviolet light energy into heat energy. Because there are ortho-hydroxyl groups on the benzene ring in its molecular structure, the heat energy is dissipated through the action of hydrogen bonds and reversible changes of molecular rearrangement. It is particularly suitable for sunscreen treatment of films and fibers, and can protect polyurethane films from ultraviolet radiation and extend the service life.

[0030] In one possible implementation, the light stabilizer is RIASORB UV-944, with a molecular weight of 2000-3000. RIASORB UV-944 is a high molecular weight hindered amine light stabilizer, which does not absorb any light greater than 260nm and cannot quench excited molecules. However, in the presence of oxygen, hindered amines can be oxidized to generate corresponding nitroxide free radicals. Such compounds are quite stable and can effectively capture active free radicals generated by photo-oxidative degradation of polymers. The ability to degrade and terminate free radicals is used to enhance the thermal oxidation resistance of the material, extend the life of the material and avoid color changes.

[0031] In a possible implementation, the solvent is dimethylformamide, referred to as DMF. DMF solvent is a commonly used reaction solvent for polymer compounds such as polyurethane, phenolic resin and polyamide, and has extremely strong dissolving ability and good stability.

[0032] In a possible implementation, the skin color paste has a color difference value of 0-1dE FullShade, a fineness of 0m-50m, and a non-volatile content of 98-100%.

[0033] In a possible implementation, the viscosity of the polyurethane base material is 10,000 mPa.S-20,000 mPa.S, the non-volatile matter content is 29-32%, and the chromaticity is less than 300.

[0034] In a possible implementation, the composition ratio of the sunscreen polyurethane film is as shown in Table 1 below.

[0035] Table 1 Component ratio of sunscreen polyurethane film

[0036] Ingredients (wt / %) Case 1 Case 2 Case 3 Case 4 Case 5 UV absorber 0 0.6 0 0.50 1.0 Light Stabilizer 0 0 0.2 0.15 0.5 Solvents 0.6 0.6 0.6 0.6 0.6 Color paste 0.5 0.5 0.5 0.5 0.5 Polyurethane base 98.9 98.3 98.7 98.25 97.4

[0037] Step 130, using glue to compound the sunscreen polyurethane film and the non-woven fabric to obtain a composite material.

[0038] Step 150: Place the composite material on a coating machine, pour the mixed two-component silicone gel into the coating machine, and adjust the coating weight to 50-1000 g / m 2 , heat and cure at 50-150℃ for 10-60 minutes, attach a release film to obtain the sunscreen scar sticker.

[0039] like Figure 2 As shown, the sunscreen scar patch has a total of five layers. The first layer is a waterproof sunscreen layer that blocks liquids and ultraviolet rays. The second layer is an adhesive layer that connects the waterproof sunscreen layer with the support layer. The third layer is a support layer that uses a non-woven fabric design to increase the strength of the scar patch, solve the problems of silicone gel easily falling off and scar patch easily curling, and increase wearing comfort. The fourth layer is a silicone gel layer that is transparent and elastic, adheres firmly, improves hydration, promotes scar maturation, and inhibits the growth of fibroblasts by releasing silicone molecules to make scars flat. The fifth layer is a release layer that protects the silicone gel from contamination and is peeled off during use.

[0040] Furthermore, the prepared sunscreen scar was placed under a UV light source for 2h, 4h, 8h, and 16h, and then the UV protection performance was tested. The sample was irradiated with UV rays with a wavelength of 290nm to 400nm, the total spectral transmission rays were collected, the total spectral transmittance was measured, and the UV protection factor UPF value of the sample was calculated.

[0041] Specifically, after taking the sample out of the constant temperature and humidity chamber, place it in an environment of (20±2)°C and (65±4)%RH for 24 hours, place the sample after humidity adjustment in a spectrophotometer test tank, and face the polyurethane film surface toward the UV light source to record the transmittance between 290nm and 400nm, at least once every 5nm.

[0042] The calculation formula is as follows:

[0043]

[0044] Among them, E(λ) is the sunlight spectral irradiance, ε(λ) is the relative spectral erythema effect, Δλ is the wavelength interval, and T(λ) is the spectral transmittance of the wavelength.

[0045] Furthermore, the test results of the effect of light on the stability of sunscreen performance are shown in Table 2 below. Among them, in case 1, no ultraviolet absorber and light stabilizer were added, and the scar patch UPF value was lower than 10, which mainly played a physical shielding role, and the sunscreen effect was not ideal; in case 2, only ultraviolet absorber was used, and the sunscreen effect was good, but the sunscreen performance was seriously attenuated over time; in case 3, only light stabilizer was used, and the sunscreen effect was not ideal. In case 4 and case 5, ultraviolet absorber Tinuvin234 and light stabilizer RIASORB UV-944 were used simultaneously, which played a synergistic role. At the same time, increasing the amount of both, the sunscreen effect was significantly enhanced. After 16 hours of UV light, the sunscreen performance maintenance rate was 78.7%-80.8%.

[0046] Table 2 Effect of UV light on the stability of sunscreen performance

[0047]

[0048] Furthermore, the test results of the effect of high temperature accelerated aging on color difference stability are shown in Table 3 below. Among them, Case 6, Case 7 and Case 8 use Pantone color card number 4775C±1 as the standard, and determine the color number of the sunscreen scar patch by changing the ratio of the color paste. In Case 6, the color paste ratio is reduced, and the color is light white; in Case 8, the color paste ratio is increased, and the color becomes darker and black-red. The color paste ratio in Case 7 is closest to the skin color and meets the Pantone color card number 4775C±1.

[0049] Table 3 Component ratio of sunscreen scar patch

[0050] Ingredients (wt / %) Case 6 Case 7 Case 8 UV absorber 0.50 0.50 0.50 Light Stabilizer 0.15 0.15 0.15 Solvents 0.6 0.6 0.6 Color paste 0.3 0.5 0.7 Polyurethane base 98.45 98.25 98.05

[0051] Further, the test results of the effect of high temperature accelerated aging on color difference stability are shown in Table 4. The chromaticity of the product of Case 7 with accelerated aging for 0 days was used as the standard sample, and the finished product of Case 4 was selected and placed in a drying oven at 55°C for 46 days, 92 days, and 138 days to simulate room temperature storage for 1 year, 2 years, and 3 years, and samples were taken at the corresponding time points to test the color difference. Test instrument: Trinity Colorimeter, model: SC-10.

[0052] Test principle: The colorimeter can measure the color difference between the sample and the standard sample. The difference between the two colors is expressed as ΔE value. The smaller the ΔE value, the closer the two colors are, which means that the UV light has less influence on the chromaticity of the sunscreen scar patch. The requirement is ΔE≤1.5.

[0053] Table 4 High temperature accelerated aging test on color difference stability

[0054]

[0055] According to the above process, it can be found that oxygen will cause the material to oxidize, and continuous high temperature will accelerate the oxidation process of the material. After the peroxide structure is formed, free radicals are easily formed, causing the material to change color. The addition of light stabilizer RIASORB UV-944 terminates the formation of free radicals and effectively avoids changes in the color of the material. The sunscreen scar patch in Case 4 was placed at 55°C for 138 days (equivalent to 3 years of storage at room temperature), and the color difference value changed by 0.89, which is in line with the Pantone color card number 4775C±1.

[0056] Furthermore, through the closed patch test, the material or its extract is applied to guinea pigs by closed patch induction and stimulation, and the skin reaction of the guinea pigs at the stimulation site is observed within a specified time to evaluate the potential of the test sample to cause skin sensitization in guinea pigs under the test conditions. The potential skin sensitization reaction of the sunscreen scar patch is tested.

[0057] Specifically, cutting case 4 sunscreen scar patch 360cm 2 , placed in 60ml of saline and soybean oil at 50±2℃ for 72±2h, each sunscreen scar patch extract was intradermally injected into 10 test group guinea pigs and sealed with bandages. Similarly, the corresponding negative control was intradermally injected into 5 control group guinea pigs and sealed with bandages. After the recovery period, the patch moistened with the sunscreen scar patch extract was applied to the back scapula area of ​​the guinea pigs for stimulation. Observe and score the application site 24 hours and 48 hours after removing the patch. The scoring rules are shown in Table 5, and the final score is shown in Table 6.

[0058] Table 5 Scoring rules for closed patch test reaction test

[0059] Patch test reaction grade No significant change 0 Scattered or macular erythema 1 Moderate confluent erythema 2 Severe erythema and edema 3

[0060] Table 6 Closed patch test reaction test results

[0061]

[0062] In the above process, it can be seen that during the experiment, the skin reaction of the test group did not exceed that of the control group. Under the conditions of this experiment, no skin allergic reaction was found in the guinea pig skin using the sunscreen scar patch in Case 4, which can prove that the sunscreen scar patch in the embodiment of the present invention is safe and non-allergenic.

[0063] like Figure 3 As shown, the UV-A transmittance, UV-B transmittance, UPF average and UPF value of the sunscreen scar patch in the untreated, dried, original and relaxed state in the embodiment of the present invention were tested at intervals of 5 nm using a SHIMADZU UV-Vis spectrophotometer UV-2600, and each test result met the standard requirements, indicating that the sunscreen scar patch in the embodiment of the present invention has good ultraviolet protection function.

[0064] like Figure 4 As shown, a comparison of a patient using the sunscreen scar patch in an embodiment of the present invention is shown. Among them, Figure (a) is before the patient used the sunscreen scar patch, and Figure (b) is after the patient used the sunscreen scar patch for 2 weeks. It can be clearly seen from the figure that the patient's affected skin was previously pigmented and dark red. After using the sunscreen scar patch for 2 weeks, the scar was significantly improved, the spots became lighter, the redness disappeared, and there was no scar hyperplasia.

[0065] Through the above process, the present invention adopts triazine ultraviolet absorber BASF Tinuvin 234 and light stabilizer RIASORB UV-944, and through synergistic effect, it can fix and absorb ultraviolet rays in the 290nm-400nm band, and the UPF value is greater than 50. Non-woven fabric is used as a supporting layer, which increases the stability and strength of the scar patch and improves the wearing comfort. The ultraviolet absorber and light stabilizer do not directly contact the skin, thereby avoiding possible skin irritation or allergic reaction. The color change of the material caused by oxidation is effectively avoided by adding a light stabilizer. After long-term use or high-temperature accelerated aging, the color remains stable, which meets the aesthetic needs of patients, and solves the problems of easy glue fall-off of silicone and easy curling of scar patches in the prior art, thereby effectively solving the problems of poor sun protection ability and poor comfort in the prior art.

[0066] In addition, the embodiments of the sunscreen scar patch and the sunscreen scar patch preparation method provided in the above embodiments belong to the same concept, and the specific manner in which each module performs the operation has been described in detail in the method embodiment and will not be repeated here.

[0067] Compared with the related art, the present invention has the following beneficial effects:

[0068] 1. The present invention adopts triazine ultraviolet absorber BASF Tinuvin 234 and light stabilizer RIASORB UV-944, and through synergistic effect, it can fix and absorb ultraviolet rays in the 290nm-400nm band, and the UPF value is greater than 50. Non-woven fabric is used as the supporting layer, which increases the stability and strength of the scar patch and improves the wearing comfort. The ultraviolet absorber and light stabilizer do not directly contact the skin, thereby avoiding possible skin irritation or allergic reaction. The color change of the material caused by oxidation is effectively avoided by adding a light stabilizer. After long-term use or high-temperature accelerated aging, the color remains stable, which meets the aesthetic needs of patients, and solves the problems of easy glue fall-off of silicone and easy curling of scar patches in the prior art, thereby effectively solving the problems of poor sun protection ability and poor comfort in the prior art.

[0069] 2. The synergistic effect of the ultraviolet absorber and the light stabilizer in the present invention makes the color of the sunscreen scar patch stable, which is particularly suitable for scars that are not blocked by clothes. It can effectively resist ultraviolet rays, prevent pigmentation and scar hyperplasia at the scar, and is safe and non-allergenic, which can reduce safety hazards and allergy risks.

[0070] 3. The sunscreen scar patch of the present invention adopts non-woven fabric as the supporting layer, which solves the problems of easy peeling of silicone and easy curling of scar patches in the prior art, and improves the wearing comfort.

[0071] It should be understood that, although the steps in the flowchart of the accompanying drawings are displayed in sequence as indicated by the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least a part of the steps in the flowchart of the accompanying drawings may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed in turn or alternately with other steps or at least a part of the sub-steps or stages of other steps.

[0072] The above descriptions are only some embodiments of the present invention. It should be pointed out that, for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A sunscreen scar patch, characterized in that: The sunscreen scar patch comprises a sunscreen polyurethane film, non-woven fabric, two-component silicone gel and a release film; the sunscreen polyurethane film comprises an ultraviolet absorber and a light stabilizer; the thickness of the sunscreen polyurethane film is 10-808 μm; the thickness of the release film is 0.1-5 mm.

2. The sunscreen scar patch according to claim 1, characterized in that: The nonwoven fabrics include pure cotton nonwoven fabrics, polyester-viscose nonwoven fabrics and polyester nonwoven fabrics.

3. The sunscreen scar patch according to claim 1, characterized in that: The material of the release film includes PC, PP, PET, PE and a composite material of PET / PE.

4. The sunscreen scar patch according to claim 1, characterized in that: The nonwoven fabric has a grammage of 8-50 g / m 2 The nonwoven fabric has a radial strength greater than 20N / 5cm and a transverse strength greater than 10N / 5cm.

5. A method for preparing a sunscreen scar patch, characterized in that: include: After the ultraviolet absorber and the light stabilizer are dispersed evenly with a solvent, the mixture is added to the polyurethane base material and stirred into a liquid, and then the skin color paste is added and mixed evenly to obtain a mixed liquid, the mixed liquid is poured on a coating machine and the thickness is adjusted to 10-808 μm, and the mixed liquid is rolled up after heating and drying to obtain a sunscreen polyurethane film; The sunscreen polyurethane film and non-woven fabric are compounded with glue to obtain a composite material; the glue is a single-component acrylic oil glue; the non-woven fabric includes cotton non-woven fabric, polyester-viscose non-woven fabric, and polyester non-woven fabric; the gram weight of the non-woven fabric is 8-50g / m 2 , radial strength greater than 20N / 5cm, lateral strength greater than 10N / 5cm; Place the composite material on a coating machine, pour in the mixed two-component silicone gel and adjust the coating weight to 50-1000 g / m 2 , heat and cure at 50-150° C. for 10-60 minutes, and attach a release film to obtain a sunscreen scar sticker; the material of the release film includes PC, PP, PET, PE and a composite material of PET / PE; the thickness of the release film is 0.1-5 mm.

6. The method for preparing the sunscreen scar patch according to claim 5, characterized in that: The ultraviolet absorber is a triazine ultraviolet absorber BASF Tinuvin 234.

7. The method for preparing the sunscreen scar patch according to claim 5, characterized in that: The light stabilizer is R IASORB8 UV-944.

8. The method for preparing the sunscreen scar patch according to claim 5, characterized in that: The solvent is dimethylformamide.

9. The method for preparing the sunscreen scar patch according to claim 5, characterized in that: The skin color paste has a color difference value of 0-1dE Full Shade, a fineness of 0 8m-50 8m, and a non-volatile matter content of 98-100%.

10. The method for preparing the sunscreen scar patch according to claim 5, characterized in that: The viscosity of the polyurethane base material is 10,000mPa.S-20,000mPa.S, the non-volatile matter content is 29-32%, and the chromaticity is less than 300.

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