Cooling gel layer, preparation method thereof and bacterial cellulose composite cooling material
By surface modification of bacterial cellulose and polymer bonding to form an interpenetrating network structure, the problems of low evaporation efficiency and insufficient water retention of existing heat-reducing patch materials are solved, achieving rapid cooling and long-term cooling effects, while also improving adhesion.
Patent Information
- Application Number
- CN202511420421.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-30
- Publication Date
- 2026-01-23
AI Technical Summary
Existing fever-reducing patch materials suffer from low evaporation efficiency and unsatisfactory cooling effects. While bacterial cellulose materials have good water absorption and cooling potential, their water retention is insufficient, resulting in short action time and poor skin adhesion.
By immersing bacterial cellulose in a polyphenolic adhesive solution for surface adhesion treatment, and then immersing it in a polymer solution to form a composite material, a triple interpenetrating network is formed through esterification/amidation reaction and hydrogen bonding, which improves adhesion and water retention, thus preparing a cooling gel layer.
It achieves rapid heat absorption and cooling, maintains cooling effect for a long time, and has good skin adhesion properties, improving user experience and usage stability.
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Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the field of medical materials and cooling materials, in particular to a cooling gel layer, a preparation method thereof and a bacterial cellulose composite cooling material. BACKGROUND
[0002] Cooling materials such as fever-reducing patches are a commonly used physical cooling product, and are widely used in emergency care and auxiliary treatment of pediatric fever and the like. The currently marketed fever-reducing patches mostly use a water gel with sodium polyacrylate as the main component as a water retention matrix, and are usually composed of a embossed film, a water gel layer and a non-woven fabric layer. The cooling principle relies on the physical process of absorbing heat when water evaporates from the gel layer, and the evaporation rate directly affects the cooling effect. However, there are still obvious deficiencies in the actual use of such products: on the one hand, the water retention of sodium polyacrylate material is strong, but the water evaporation is slow, resulting in no obvious change in water content before and after use, limited evaporation amount, and it is difficult to achieve rapid or significant cooling, and the fever-reducing effect is generally poor.
[0003] On the other hand, bacterial cellulose is a natural polymer material, and bacterial cellulose is a natural polymer produced by fermentation of certain types of bacteria (most commonly Komagataeibacter xylinus). It has the same chemical structure as cellulose from plants (both are glucose chains connected by β-1, 4-glucoside bonds), but its physical structure, purity and performance are very different. Under a microscope, BC presents a three-dimensional porous network structure formed by interweaving extremely fine cellulose nanofibers (3-8 nanometers in diameter). This structure makes it have many extraordinary properties.
[0004] Because bacterial cellulose has excellent water absorption, biocompatibility and cooling properties, it has also been explored for use in cooling patches. Bacterial cellulose has a high initial water content and evaporation rate, and has a good cooling effect in a short time. However, the single bacterial cellulose material has poor water retention performance, and the water evaporates too quickly, resulting in a short cooling duration and failing to meet the demand for continuous fever reduction. In addition, due to its high surface water content, a water film is easily formed at the interface between the skin and the material, significantly reducing the adhesion of the patch, affecting the stability and comfort of use.
[0005] Therefore, the existing fever-reducing patch materials face the following problems: first, the conventional sodium polyacrylate-based fever-reducing patch has low evaporation efficiency and unsatisfactory cooling effect; second, although bacterial cellulose material has good water absorption and cooling potential, its water retention is insufficient, resulting in a short duration of action and poor skin adhesion. These factors limit its performance and user experience in practice, and it is urgent to improve it through material modification and structure design. SUMMARY
[0006] The application provides a cooling gel layer, a preparation method thereof and a bacterial cellulose composite cooling material. The obtained composite cooling material can simultaneously realize rapid heat absorption and cooling, long-time cooling effect maintenance, and has good skin adhesion performance.
[0007] Technical scheme
[0008] In a first aspect, the application provides a preparation method of a cooling gel layer. Bacterial cellulose is soaked in an adhesive solution containing a polyphenol adhesive for surface adhesion treatment, and then soaked in a polymer solution. After mixing and stirring, a composite material is formed. After washing and water pressing, excess water is removed to obtain a gel layer.
[0009] The polymer solution comprises a polymer, and the polymer comprises any one or a combination of multiple of carboxymethyl cellulose sodium, polyacrylic acid sodium, polyvinyl alcohol, polyvinylpyrrolidone, chitosan, sodium alginate, agar, and sodium hyaluronate.
[0010] Preferably, the bacterial cellulose is a water-containing film or a freeze-dried film.
[0011] In the application, the adhesive in the adhesive solution reacts with the bacterial cellulose (BC) through esterification / amidation reaction and is fixed on the surface of the bacterial cellulose. Meanwhile, the abundant hydrophilic groups thereof are combined with the bacterial cellulose (BC) through strong hydrogen bond effect, and the hydrophobic end thereof faces outward, reducing the water film on the surface of the BC and significantly improving the initial adhesion to the skin. The abundant hydrophilic groups of the adhesive provide more reaction anchor points for deep combination with the polymer in the polymer solution.
[0012] Through soaking, the polymer is immersed in the bacterial cellulose with the attached adhesive, and is combined with the BC and the grafted adhesive through physical winding and / or hydrogen bond effect, forming a triple interpenetrating network. The network has good toughness, and gives the gel high wet mechanical strength. The hydrophilic groups in the interpenetrating network effectively 'bind' water molecules, thereby slowing down the evaporation rate of water.
[0013] The adhesive, the polymer and the bacterial cellulose have mutual synergy in performance. The adhesive provides a more stable combination platform for the polymer, so that the polymer network can be more stably and uniformly fixed on the BC skeleton. The polymer network consolidates and stabilizes the crosslinking effect of the adhesive, so that the whole structure is more compact and firm. Through the combined action of the three, a good balance between the super water absorption of the BC and the water locking property and good adhesion of the PVA is achieved.
[0014] Further, the concentration of the polyphenol adhesive in the adhesive solution is 0.5-2 wt%, and the mass ratio of the bacterial cellulose to the adhesive solution is 1:5-100.
[0015] Further, the polyphenol adhesive comprises gallic acid and / or dopamine.
[0016] Further, the adhesive solution further comprises a concentration of 0.001-0.01 wt% EDS reaction aids and a concentration of 0.001-0.01 wt% NHS reaction aids.
[0017] Further, the pH of the adhesive solution is 8-9.
[0018] Further, the concentration of the polymer in the polymer solution is 0.1-10.0 wt%, and the mass ratio of the bacterial cellulose to the polymer solution is 1:5-100.
[0019] Further, the polymer solution further comprises a concentration of 1-10 wt% humectants, the humectants comprising glycerol and / or honey.
[0020] Further, the polymer solution further comprises a concentration of 0.05-0.5 wt% antibacterial agents, the antibacterial agents comprising any one or a combination of several of p-hydroxyacetophenone, potassium sorbate, phenoxyethanol, methylparaben, PHMB.
[0021] In a second aspect, the present application provides a cooling gel layer, characterized in that the gel layer is obtained by the preparation method described in the present application, and the water content of the gel layer is 80-99 wt%.
[0022] In a third aspect, the present application provides a bacterial cellulose composite cooling material, which comprises, in sequence, the gel layer described in the present application, an embossed film, and a non-woven fabric layer.
[0023] Beneficial effects: 1. The preparation method of the cooling gel layer provided by the present application controls the water content through water pressing process, reduces the formation of water film, and increases the adhesion; then the bacterial cellulose film is soaked in the polymer solution, so that the polymer enters the three-dimensional skeleton network of the bacterial cellulose, and the gel layer is obtained after water pressing; wherein the bacterial cellulose and the polymer solution are fully combined to play a synergistic effect, and the interpenetrating network structure improves the water retention effect, the cooling time, and the fever-reducing effect of the composite cooling material. At the same time, the composite material has good mechanical properties, making the cooling material more soft and comfortable. In addition, the preparation process of the technical solution of the present application is simple, the cost is low, and it is conducive to industrialized production. DETAILED DESCRIPTION
[0024] In order to make the technical solution of the present application clearer, the present application will be further described in detail below in combination with specific embodiments.
[0025] In the examples and comparative examples of the present application, the bacterial cellulose is a freeze-dried film, and in other examples, the bacterial cellulose can also be a water-containing film.
[0026] Embodiment 1, a preparation method of a bacterial cellulose composite cooling material, comprising the following preparation steps:
[0027] The bacterial cellulose is soaked in an adhesive solution containing a polyphenol adhesive for surface adhesion treatment, and then soaked in a polymer solution, heated and stirred to combine the polymer molecular chain with the bacterial cellulose network to form a bacterial cellulose / polymer composite material; secondly, the obtained composite material is washed and pressed to remove excess water to obtain a gel layer; finally, the gel layer is combined with an embossed film and a non-woven fabric layer to prepare a bacterial cellulose composite cooling material; the obtained composite cooling material can simultaneously achieve rapid heat absorption and cooling, long-time cooling effect maintenance, and good skin adhesion performance.
[0028] Optionally, the bacterial cellulose is a water-containing film or a freeze-dried film.
[0029] The adhesive in the adhesive solution can be a solution of gallic acid, dopamine and other polyphenol substances, with a concentration of 0.5-2 wt%, containing EDS and NHS and other reaction aids, with a solution pH of 8-9 and a concentration of 0.001-0.01 wt%, and sodium hydroxide can be used to adjust the pH to 8-9, which can increase the stirring speed to accelerate the reaction, and the stirring speed is 50-300 rpm.
[0030] The weight ratio of bacterial cellulose to adhesive solution and the weight ratio of bacterial cellulose to polymer solution are both in the range of 1:5 to 1:100.
[0031] The polymer can be one or more of sodium carboxymethyl cellulose, polyacrylic acid sodium, polyvinyl alcohol, polyvinylpyrrolidone, chitosan, sodium alginate, agar, and sodium hyaluronate, and the bacterial cellulose is soaked in the polymer solution to fully combine the bacterial cellulose with the polymer, and the content of the polymer in the composite cooling material is 0.1-10.0 wt%.
[0032] The composite material after pressing is used as a gel layer with a water content of 80.0-99.0 wt%, and the gel layer is combined with an embossed film and a non-woven fabric layer to cut and prepare a bacterial cellulose composite cooling material.
[0033] The thickness of the gel layer in the bacterial cellulose composite cooling material is in the range of 1-15 mm; preferably, the thickness of the gel layer is in the range of 1-10 mm.
[0034] In addition, in order to further improve the water retention performance of the composite material, 1-10 wt% of a humectant such as glycerol and honey can be added to the polymer solution; in order to enhance the antibacterial performance of the composite material, a certain amount of an antibacterial agent such as p-hydroxyacetophenone, potassium sorbate, phenoxyethanol, methylparaben, PHMB, etc. can be added to the polymer solution, and the concentration of the antibacterial agent is 0.05-0.5 wt%.
[0035] Example 2, a method for preparing a bacterial cellulose composite cooling material, comprising the following preparation steps:
[0036] 1) Soak bacterial cellulose (lyophilized membrane) in a solution containing 0.5 wt% gallic acid, 0.001 wt% EDC (1-ethyl-(3-dimethylaminopropyl) carbonyldiimide), 0.001 wt% NHS (N-hydroxysuccinimide), adjust the pH of the solution to 8, stir at a speed of 50 rpm, and filter after sufficient reaction.
[0037] 2) After filtering the bacterial cellulose treated in step 1), soak it in a 1 wt% sodium carboxymethyl cellulose solution, and stir at elevated temperature to combine the polymer molecular chain with the bacterial cellulose network to form a bacterial cellulose / polymer composite material.
[0038] 3) Wash the obtained composite material and press water to a water content of 99 wt% (bacterial cellulose weight ratio 1 wt%, water content 99 wt%), remove excess water, and obtain a gel layer.
[0039] 4) Combine the gel layer with a embossed film and a non-woven fabric layer to make a bacterial cellulose composite cooling material, wherein the thickness of the gel layer is 5 millimeters.
[0040] Example 3, a method for preparing a bacterial cellulose composite cooling material, comprising the following preparation steps:
[0041] 1) Soak bacterial cellulose in a solution containing 1.0 wt% gallic acid, 0.005 wt% EDS, and 0.005 wt% NHS, adjust the pH of the solution to 8.5, stir at a speed of 200 rpm, and filter after sufficient surface adhesion treatment.
[0042] 2) Soak in a 5 wt% sodium alginate solution, and stir at elevated temperature to combine the polymer molecular chain with the bacterial cellulose network to form a bacterial cellulose / polymer composite material.
[0043] 3) Wash the obtained composite material and press water to a water content of 95 wt%, remove excess water, and obtain a gel layer.
[0044] 4) Combine the gel layer with a embossed film and a non-woven fabric layer to make a bacterial cellulose composite cooling material.
[0045] Example 4, a method for preparing a bacterial cellulose composite cooling material, comprising the following preparation steps:
[0046] 1) The bacterial cellulose is soaked in a solution containing 2.0 wt% dopamine, 0.01 wt% EDS, 0.01 wt% NHS, the solution is adjusted to pH 9, the stirring speed is 300 rpm, and the surface adhesion treatment is performed after sufficient reaction, and then filtered.
[0047] 2) The bacterial cellulose is soaked in a 10 wt% polyvinyl alcohol solution, heated and stirred to combine the polymer molecular chains with the bacterial cellulose network to form a bacterial cellulose / polymer composite material.
[0048] 3) The obtained composite material is washed and pressed to a water content of 80 wt% to remove excess water to obtain a gel layer.
[0049] 4) The gel layer is combined with an embossed film and a non-woven fabric layer to make a bacterial cellulose composite cooling material.
[0050] In addition to the above examples, a humectant can be further added to the polymer solution.
[0051] Example 5, a preparation method of a bacterial cellulose composite cooling material, comprising the following preparation steps:
[0052] 1) The bacterial cellulose is soaked in a solution containing 1.0 wt% dopamine, 0.01 wt% EDS, 0.01 wt% NHS, the solution is adjusted to pH 8.5, the stirring speed is 200 rpm, and the surface adhesion treatment is performed after sufficient reaction, and then filtered.
[0053] 2) The bacterial cellulose is soaked in a 2 wt% chitosan, 3 wt% sodium alginate, 1 wt% honey solution, heated and stirred to combine the polymer molecular chains with the bacterial cellulose network to form a bacterial cellulose / polymer composite material.
[0054] 3) The obtained composite material is washed and pressed to a water content of 92 wt% to remove excess water to obtain a gel layer.
[0055] 4) The gel layer is combined with an embossed film and a non-woven fabric layer to make a bacterial cellulose composite cooling material.
[0056] Example 6, a preparation method of a bacterial cellulose composite cooling material, comprising the following preparation steps:
[0057] 1) The bacterial cellulose is soaked in a solution containing 1.0 wt% gallic acid, 0.01 wt% EDS, 0.01 wt% NHS, the solution is adjusted to pH 8.5, the stirring speed is 200 rpm, and the surface adhesion treatment is performed after sufficient reaction, and then filtered.
[0058] 2) Soak in 10 wt% polyvinyl alcohol, 10 wt% glycerol solution, heat and stir to make the polymer molecular chain combine with the bacterial cellulose network, forming a bacterial cellulose / polymer composite material.
[0059] 3) After washing the obtained composite material, press water to a water content of 80 wt%, remove excess water, and obtain a gel layer.
[0060] 4) Combine the gel layer with the embossed film and non-woven fabric layer to make a bacterial cellulose composite cooling material.
[0061] Further, an antibacterial agent can be added to the polymer solution.
[0062] Example 7, a preparation method of a bacterial cellulose composite cooling material, comprising the following preparation steps:
[0063] 1) Soak the bacterial cellulose in a solution containing 1.0 wt% dopamine, 0.005 wt% EDS, and 0.005 wt% NHS, adjust the solution to a pH of 8.5, and stir at a speed of 100 rpm for surface adhesion treatment, and then filter.
[0064] 2) Soak in a 2 wt% sodium polyacrylate, 5 wt% glycerol, and 0.1 wt% phenoxyethanol solution, heat and stir to make the polymer molecular chain combine with the bacterial cellulose network, forming a bacterial cellulose / polymer composite material.
[0065] 3) After washing the obtained composite material, press water to a water content of 90 wt%, remove excess water, and obtain a gel layer.
[0066] 4) Combine the gel layer with the embossed film and non-woven fabric layer to make a bacterial cellulose composite cooling material.
[0067] Example 8, a preparation method of a bacterial cellulose composite cooling material, comprising the following preparation steps:
[0068] 1) Soak the bacterial cellulose in a solution containing 1.0 wt% gallic acid, 0.005 wt% EDS, and 0.005 wt% NHS, adjust the solution to a pH of 8.5, and stir at a speed of 100 rpm for surface adhesion treatment, and then filter.
[0069] 2) Soak in a 2 wt% agar, 0.1 wt% sodium hyaluronate, 5 wt% glycerol, and 0.1 wt% phenoxyethanol solution, heat and stir to make the polymer molecular chain combine with the bacterial cellulose network, forming a bacterial cellulose / polymer composite material.
[0070] 3) The obtained composite material is washed and pressed to a water content of 90 wt% to remove excess water, obtaining a gel layer; 4) The gel layer is combined with the embossed film and non-woven fabric layer to make the bacterial cellulose composite cooling material.
[0071] Table 1, raw material list used in Examples 2 to 8
[0072]
[0073] Comparative Example 1, a method for preparing a bacterial cellulose composite cooling material, comprising the following preparation steps:
[0074] 1) The pure bacterial cellulose is fully rehydrated and pressed to a water content of 80% to remove excess water, obtaining a gel layer.
[0075] 2) The gel layer is combined with the embossed film and non-woven fabric layer to make the bacterial cellulose cooling material.
[0076] Comparative Example 2, a method for preparing a bacterial cellulose composite cooling material, comprising the following preparation steps:
[0077] 1) The pure bacterial cellulose is fully rehydrated and pressed to a water content of 90 wt% to remove excess water, obtaining a gel layer.
[0078] 2) The gel layer is combined with the embossed film and non-woven fabric layer to make the bacterial cellulose cooling material.
[0079] Comparative Example 3, a method for preparing a bacterial cellulose composite cooling material, comprising the following preparation steps:
[0080] 1) The pure bacterial cellulose is fully rehydrated and pressed to a water content of 92 wt% to remove excess water, obtaining a gel layer.
[0081] 2) The gel layer is combined with the embossed film and non-woven fabric layer to make the bacterial cellulose cooling material.
[0082] Comparative Example 4, a method for preparing a bacterial cellulose composite cooling material, comprising the following preparation steps:
[0083] 1) The pure bacterial cellulose is fully rehydrated and pressed to a water content of 95 wt% to remove excess water, obtaining a gel layer.
[0084] 2) The gel layer is combined with the embossed film and non-woven fabric layer to make the bacterial cellulose cooling material.
[0085] Comparative Example 5, a method for preparing a bacterial cellulose composite cooling material, comprising the following preparation steps:
[0086] 1) The pure bacterial cellulose is fully rehydrated and pressed to a water content of 99 wt% to remove excess water, obtaining a gel layer.
[0087] 2) The gel layer is combined with embossed film and non-woven fabric layer to make bacterial cellulose cooling material.
[0088] Performance test
[0089] The comparative examples and examples are subjected to adhesion time test and cooling effect test, and the results are shown in Table 2:
[0090] Skin contact time (good adhesion is indicated by √, weakened adhesion is indicated by o, and adhesion failure is indicated by x)
[0091] Table 2: List of adhesion time of bacterial cellulose cooling material obtained from examples and comparative examples
[0092]
[0093] Table 3: List of skin surface temperature difference before and after use of bacterial cellulose cooling material obtained from examples and comparative examples
[0094]
[0095] As can be seen from Tables 2 and 3, the cooling time of single bacterial cellulose material is 3-4 h, the cooling time of bacterial cellulose composite material is 6-8 h, the skin surface temperature of the contact part can be reduced by 0.5-0.8℃ during use, the adhesion effect is increased after surface treatment, and the material is not easy to fall off within 6-8 h of skin contact time. Moreover, the preparation process of the present application is simple, the cost is low, and it is conducive to industrialized production.
[0096] In Example 4, the material may become brittle, the water holding capacity may decrease, the water evaporation channel may be blocked, and the cooling effect may be poor due to too high dopamine content and excessive crosslinking.
[0097] The cooling effect and adhesion time of Examples 3, 4 and 5 are all better, preferably, the concentration of polyphenol adhesion agent in the adhesion agent solution is 0.5-1.5 wt%, the concentration of polymer in the polymer solution is 5-10.0 wt%, and the type of polymer is preferably polyvinyl alcohol, chitosan and sodium alginate. It may be because the adhesion agent, polymer and bacterial cellulose in Examples 3, 4 and 5 have a synergistic effect on performance, a perfect balance between the super water absorption of BC, the water retention of polymer and the adhesion performance of adhesion agent is achieved, and a good balance between water absorption, moisture retention and adhesion effect is achieved.
[0098] The water content in the bacterial cellulose affects the formation of the water film on the surface of the bacterial cellulose, and the adhesion of the thick water film layer decreases, so the skin adhesion is better under the condition of lower water content. Meanwhile, the reduction of water content will affect the cooling effect brought by the large specific heat of water, so a certain water content is required to ensure the cooling effect.
[0099] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it cannot be understood as limiting the scope of the patent of the present application. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, several modifications and improvements can be made, which belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.
Claims
1. A method for preparing a cooling gel layer, characterized by, The bacterial cellulose is soaked in an adhesive solution containing a polyphenol adhesive for surface adhesion treatment, then soaked in a polymer solution, mixed and stirred to form a composite material, washed and pressed to remove excess water to obtain a gel layer; The polymer solution comprises a polymer, and the polymer comprises any one or a combination of more than one of sodium carboxymethyl cellulose, sodium polyacrylate, polyvinyl alcohol, polyvinylpyrrolidone, chitosan, sodium alginate, agar, and sodium hyaluronate.
2. The method of claim 1, wherein the cooling gel layer is prepared by mixing the gel base and the cooling agent in a ratio of 1:0.1 to 1:0.
5. The concentration of the polyphenol adhesive in the adhesive solution is 0.5-2 wt%, and the mass ratio of the bacterial cellulose to the adhesive solution is 1:5-100.
3. The method of claim 1 or 2, wherein the cooling gel layer is prepared by mixing the gel base and the cooling agent in a ratio of 1 : 1 to 1 :
3. The polyphenol adhesive comprises gallic acid and / or dopamine.
4. The method of claim 3, wherein the cooling gel layer is prepared by mixing the gel base and the cooling agent in a ratio of 1 : 1 to 1 :
3. The adhesive solution further comprises 1-ethyl-(3-dimethylaminopropyl) carbonyl diimide with a concentration of 0.001-0.01 wt% and N-hydroxysuccinimide with a concentration of 0.001-0.01 wt%.
5. The method of claim 1, 2, 4, wherein the cooling gel layer is prepared by mixing the gel base and the cooling agent in a ratio of 1: 1 to 1:
3. The pH of the adhesive solution is 8-9.
6. The method of claim 5, wherein the cooling gel layer is prepared by mixing the gel base and the cooling agent in a ratio of 1:0.1 to 1:0.
5. The concentration of the polymer in the polymer solution is 0.1-10.0 wt%, and the mass ratio of the bacterial cellulose to the polymer solution is 1:5-100.
7. The method of claim 1, 2, 4, or 6, wherein the cooling gel layer is prepared by the steps of: The polymer solution further comprises a humectant with a concentration of 1-10 wt%, and the humectant comprises glycerol and / or honey.
8. The method of claim 7, wherein the temperature-reducing gel layer is prepared by mixing the temperature-reducing gel composition and the solvent in a ratio of 1: 1 to 1:
10. The polymer solution further comprises an antibacterial agent with a concentration of 0.05-0.5 wt%, and the antibacterial agent comprises any one or a combination of more than one of p-hydroxyacetophenone, potassium sorbate, phenoxyethanol, methylparaben, and PHMB.
9. A cooling gel layer obtained by the production method according to any one of claims 1 to 8, characterized by, The water content of the gel layer is 80-99 wt%.
10. A bacterial cellulose composite cooling material, characterized by, The gel layer, the embossed film, and the non-woven fabric layer are sequentially arranged. The gel layer, the embossed film, and the non-woven fabric layer are sequentially arranged.