Defervescence hydrogel, preparation method and application thereof, and hydrogel defervescence patch

Abstract

The invention relates to the technical field of fever cooling patches, in particular to fever cooling hydrogel, a preparation method and application thereof and a hydrogel fever cooling patch. The cooling hydrogel is prepared from a polyvinyl alcohol solution, a gelatin solution and a sodium tetraborate solution; the mass percentage content of the polyvinyl alcohol solution is 10-20%; the mass percentage content of the gelatin solution is 20%; the mass percentage of the sodium tetraborate solution is 1-4%; the volume ratio of the polyvinyl alcohol solution to the gelatin solution to the sodium tetraborate solution is (3-5): (1-3): (1-5). The limitation of a non-woven fabric backing layer is removed, the selected gel matrix is hydrogel with enough tensile property and formability, when a patient reserves the fever cooling patch, the patient does not need to purchase an adult style or a child style, and the area of the fever cooling patch can be changed through stretching. The fever cooling patch is free of limitation of non-woven fabric, flexibility of the fever cooling patch is improved, and the fever cooling patch is suitable for all parts of the body. Therefore, the fever cooling patch is more flexible when being used by a patient.

Description

Technical Field

[0001] The invention relates to the technical field of cooling patches, and in particular to a cooling hydrogel and a preparation method and application thereof, and a cooling hydrogel patch. Background Art

[0002] For fever symptoms, external physical cooling methods can be used to assist in cooling down and reduce the discomfort caused by high body temperature. At present, external physical cooling methods generally include wet wipes, medical ice pads, medical ice bags, cooling compresses, etc. The cooling principles include heat conduction cooling and water vapor evaporation heat absorption cooling, or the chemical reaction or dissolution of substances to produce heat absorption effects. Among the various auxiliary cooling methods, the advantages of gel cooling patches are simple production methods and low costs, small size, easy to carry, easy to use, and have the characteristics of long action time and a wide range of action sites; and the cooling sensation provided is moderate and will not cause discomfort.

[0003] The principle of the cooling patch is heat conduction. After applying the cooling patch, the local body temperature can be reduced to achieve a cooling effect. The cooling patch is a common physical cooling method and can be used on the head, armpits, neck, groin, etc. As the water vapor in the cooling patch gel evaporates, the temperature of the cooling patch decreases, helping the body to dissipate heat and thus playing a cooling role. In addition, when water vapor evaporates from the body surface, it also absorbs body heat. Therefore, gel cooling patches are widely used in auxiliary cooling treatment for patients with fever.

[0004] The existing cooling patches have the following shortcomings:

[0005] 1. Due to the limitation of the backing layer of the cooling patch, most cooling patches on the market have no elasticity. When using them, patients need to buy cooling patches of different sizes according to the size of their foreheads, or trim ordinary cooling patches to the appropriate size with scissors. This is more troublesome to use and cannot be generally used by people of all ages.

[0006] 2. The hydrogel matrix of the cooling patch currently on the market has poor formability and needs to be maintained by non-woven fabrics. The gel needs to be coated on a non-woven fabric backing during preparation, which is a relatively complicated process.

[0007] 3. When in use, the cooling patch can be applied to the forehead, neck, hand and foot joints, armpits, groin and other parts that need cooling. However, the neck, armpits, hand and foot joints, groin and other parts are often active, causing the skin in these parts to move. The non-woven cooling patches on the market have no elasticity, which will cause the cooling patch to pull the skin, causing discomfort, redness and swelling, and even fall off.

[0008] Therefore, it is necessary to prepare a cooling patch without backing layer restriction, and give the cooling patch the ability to stretch and change size, so that it is universal and comfortable to use. In addition, the current gel cooling patch matrix has poor tensile properties and formability, and it is necessary to adjust the composition of the cooling patch to improve its gel properties. Summary of the invention

[0009] In order to solve the above problems, the present invention provides a cooling water gel and a preparation method and application thereof, and a hydrogel cooling patch. The hydrogel cooling patch prepared from the cooling water gel provided by the present invention has no backing, is stretchable, has excellent flexibility, can change the area size of the cooling patch, and the selected materials have high biological safety, and at the same time have good skin compatibility and the effect of moisturizing the skin.

[0010] In order to achieve the above object, the present invention provides the following technical solutions:

[0011] The present invention provides a dehydrating gel, which is prepared from a polyvinyl alcohol solution, a gelatin solution and a sodium tetraborate solution;

[0012] The mass percentage of the polyvinyl alcohol solution is 10-20%;

[0013] The mass percentage of the gelatin solution is 20%;

[0014] The mass percentage of the sodium tetraborate solution is 1 to 4%;

[0015] The volume ratio of the polyvinyl alcohol solution, the gelatin solution and the sodium tetraborate solution is 3-5:1-3:1-5.

[0016] Preferably, the dehydrating gel further comprises glycerol, and the volume ratio of the polyvinyl alcohol solution to the glycerol is 3-5:0.1.

[0017] Preferably, the dehydrating gel further comprises theobromine, menthol and ethyl methyl paraben;

[0018] The mass ratio of the volume of the polyvinyl alcohol solution to the mass of theobromine, the mass of menthol, and the mass of ethyl methyl p-hydroxybenzoate is 3-5 ml: 0.1 g: 0.1 g: 0.1 g.

[0019] The present invention also provides a method for preparing the dehydrating gel described in the above technical solution, comprising the following steps:

[0020] 1) mixing the polyvinyl alcohol solution and the gelatin solution to obtain a mixed solution;

[0021] 2) mixing the mixed solution obtained in step 1) with the sodium tetraborate solution to obtain a gel solution;

[0022] 3) forming the gel solution obtained in step 2) to obtain a dehydrating gel.

[0023] Preferably, when the dehydrating gel further comprises glycerol, the polyvinyl alcohol solution is mixed with the gelatin solution and glycerol to obtain a mixed solution.

[0024] Preferably, when the dehydrating gel further comprises theobromine, menthol and ethyl methyl paraben,

[0025] Mixing the polyvinyl alcohol solution with gelatin solution, theobromine and menthol to obtain a mixed solution;

[0026] The mixed solution is mixed with the sodium tetraborate solution and ethyl methyl p-hydroxybenzoate to obtain a gel solution.

[0027] Preferably, after the gel solution is formed, it is immersed in a sodium sulfate solution for 30 minutes to obtain a dehydrated gel;

[0028] The mass percentage of the sodium sulfate solution is 15%.

[0029] The present invention also provides a hydrogel cooling patch, which comprises, from top to bottom, an upper anti-adhesive layer, the cooling hydrogel described in the above technical solution, and a lower anti-adhesive layer.

[0030] Preferably, the components of the upper anti-adhesive layer and the lower anti-adhesive layer are both medical embossed plastic films;

[0031] The thickness of the dehydrating gel is 4 mm.

[0032] The present invention also provides the use of the cooling water gel described in the above technical solution or the hydrogel cooling patch described in the above technical solution in the preparation of cooling products.

[0033] The cooling mechanism of the present invention is the same as that of conventional cooling patches, which physically absorbs heat through the evaporation of water on the surface of the cooling gel, taking away heat, thereby achieving a cooling effect. However, the gel of the cooling patch on the market has poor formability, so a backing layer is required to shape the gel to keep it in a sheet shape, while the gel matrix of the cooling patch has good formability, does not require a backing to provide mechanical strength, removes the limitation of the backing layer, and cross-links polyvinyl alcohol and sodium tetraborate to form a dynamic borate ester bond, giving the cooling patch good tensile and forming properties.

[0034] Beneficial effects of the present invention:

[0035] 1. The limitation of the non-woven backing layer is removed, and the gel matrix is ​​selected as a hydrogel with sufficient stretchability and formability. When patients reserve the cooling patch, they do not need to buy adult or children's version, and the area of ​​the cooling patch can be changed by stretching. Therefore, this cooling patch is suitable for people of all ages.

[0036] 2. The hydrogel matrix of the cooling patch currently on the market has poor formability and needs to be maintained in sheet form with the help of non-woven fabric. The cooling gel is coated on the non-woven fabric backing, which is costly and complicated to prepare. Therefore, the cooling patch has the advantages of simple preparation and low cost.

[0037] 3. The cooling patch can be applied to the forehead, neck, joints of hands and feet, underarms, groin and other parts that need cooling. However, the neck, underarms, joints of hands and feet, groin and other parts are often active, and the non-woven cooling patch on the market has no elasticity, which will cause the cooling patch to pull the skin, causing discomfort and redness and swelling, and even fall off. This cooling patch removes the restrictions of non-woven fabrics, increases its flexibility, and is suitable for all parts of the body. Therefore, this cooling patch is more flexible when used by patients. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required to be used in the embodiments are briefly introduced below.

[0039] Figure 1 Instructions for use of the backing-free stretchable cooling patch of the present invention;

[0040] Figure 2 The present invention provides a preparation process of the backing-free stretchable cooling patch. DETAILED DESCRIPTION

[0041] The present invention provides a dehydrating gel, which is prepared from a polyvinyl alcohol solution, a gelatin solution and a sodium tetraborate solution; the mass percentage of the polyvinyl alcohol solution is 10-20%; the mass percentage of the gelatin solution is 20%; the mass percentage of the sodium tetraborate solution is 1-4%; the volume ratio of the polyvinyl alcohol solution, the gelatin solution and the sodium tetraborate solution is 3-5:1-3:1-5. In the present invention, the polyvinyl alcohol is used as a dehydrating gel matrix, and the preferred degree of polyvinyl alcohol hydrolysis is 98.0-99.0 mol%, and the viscosity is 3.2-3.8 mPas. In the present invention, the gelatin is used as a molding agent to improve the mechanical strength and moldability of the dehydrating gel matrix. In the present invention, the sodium tetraborate is used as a cross-linking agent to cross-link polyvinyl alcohol.

[0042] In the present invention, the dehydrating gel preferably further comprises glycerol, and the volume ratio of the polyvinyl alcohol solution to the glycerol is 3-5:0.1. In the present invention, the glycerol is used as a moisturizer.

[0043] In the present invention, the dehydrating gel also preferably includes theobromine, menthol and ethyl methyl parahydroxybenzoate; the volume of the polyvinyl alcohol solution and the mass of theobromine, the mass of menthol and the mass of ethyl methyl parahydroxybenzoate are in a ratio of 3 to 5 ml: 0.1 g: 0.1 g: 0.1 g. In the present invention, theobromine is added as a bittering agent to prevent children from accidentally ingesting it and improve the safety of the present invention. In the present invention, the menthol is used as a water-soluble cooling agent to reduce the temperature by chemical methods and improve the antipyretic ability. In the present invention, ethyl methyl parahydroxybenzoate is used as a preservative.

[0044] The present invention also provides a method for preparing the dehydrating gel described in the above technical solution, comprising the following steps:

[0045] 1) mixing the polyvinyl alcohol solution and the gelatin solution to obtain a mixed solution;

[0046] 2) mixing the mixed solution obtained in step 1) with the sodium tetraborate solution to obtain a gel solution;

[0047] 3) forming the gel solution obtained in step 2) to obtain a dehydrating gel.

[0048] In the present invention, when the dehydrating gel preferably further comprises glycerol, the polyvinyl alcohol solution is mixed with a gelatin solution and glycerol to obtain a mixed solution. In the present invention, when the dehydrating gel preferably further comprises theobromine, menthol and ethyl methyl paraben, the polyvinyl alcohol solution is mixed with a gelatin solution, theobromine and menthol to obtain a mixed solution; the mixed solution is mixed with the sodium tetraborate solution and ethyl methyl paraben to obtain a gel solution.

[0049] In the present invention, after the gel solution is formed, it is preferably immersed in a sodium sulfate solution for 30 minutes to obtain a dehydrated gel; the mass percentage of the sodium sulfate solution is preferably 15%. In the present invention, the role of the sodium sulfate solution immersion is to improve the mechanical strength of the gel solution.

[0050] The preferred gel solution of the present invention is injected into a mold container to form a dehydrated gel. In the present invention, the size of the mold container is 5*15 cm.

[0051] The present invention also provides a hydrogel cooling patch, which comprises, from top to bottom, an upper anti-adhesive layer, the cooling gel described in the above technical solution, and a lower anti-adhesive layer. In the present invention, the upper anti-adhesive layer and the lower anti-adhesive layer are preferably medical embossed plastic films; the thickness of the cooling gel is preferably 4 mm. In the present invention, the preparation method of the hydrogel cooling patch preferably comprises:

[0052] 1) mixing the polyvinyl alcohol solution and the gelatin solution to obtain a mixed solution;

[0053] 2) mixing the mixed solution obtained in step 1) with the sodium tetraborate solution to obtain a gel solution;

[0054] 3) forming the gel solution obtained in step 2) to obtain a dehydrating gel.

[0055] Preferably, when the dehydrating gel further comprises glycerol, the polyvinyl alcohol solution is mixed with the gelatin solution and glycerol to obtain a mixed solution.

[0056] The present invention has no particular limitation on the method of using the hydrogel and hydrogel cooling patch.

[0057] The present invention also provides the use of the cooling water gel described in the above technical solution or the hydrogel cooling patch described in the above technical solution in the preparation of cooling products.

[0058] In order to further illustrate the present invention, the present invention is described in detail below in conjunction with embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0059] Example 1

[0060] Stretchable cooling patch K1:

[0061] The invention comprises a gel layer, which is prepared by using a gel solution; the gel solution has a formula of 85.8% deionized water, 0.2% sodium tetraborate, 12% polyvinyl alcohol and 2% gelatin in terms of mass percentage.

[0062] The preparation method of the cooling patch is as follows:

[0063] Step 1: preparing raw materials, including 20% ​​by weight polyvinyl alcohol solution, 1% by weight sodium tetraborate solution, and 20% by weight gelatin solution;

[0064] Step 2: 12 ml of 20% polyvinyl alcohol and 4 ml of 20% gelatin were mixed at 50° C. to obtain a mixture 1;

[0065] Step 3: Mix the mixture 1 and 4 ml of 1% sodium tetraborate solution, and stir at 50 rpm for 1 min to obtain a gel solution;

[0066] Step 4: Inject the gel liquid into a circular mold container with a diameter of 5 cm to form a circular stretchable cooling patch K1 with a thickness of 4 cm and a diameter of 5 cm.

[0067] Example 2

[0068] Stretchable cooling patch K2:

[0069] The invention comprises a gel layer, which is prepared by using a gel solution; the gel solution is formulated by mass percentage as follows: 87% deionized water, 2% sodium tetraborate, 10% polyvinyl alcohol and 1% gelatin.

[0070] The preparation method of the stretchable cooling patch is as follows:

[0071] Step 1: prepare raw materials, including 20% ​​by weight polyvinyl alcohol solution, 4% by weight sodium tetraborate solution, and 20% by weight gelatin solution;

[0072] Step 2: heating and mixing 10 ml of 20% polyvinyl alcohol and 2 ml of 20% gelatin at 50° C. to obtain a mixture 1;

[0073] Step 3: Mix the mixture 1 and 10 ml of 4% sodium tetraborate solution, and stir at 50 rpm for 1 min to obtain a gel solution;

[0074] Step 4: Inject the gel liquid into a circular mold container with a diameter of 5 cm to form a circular stretchable cooling patch K2 with a thickness of 4 cm and a diameter of 5 cm.

[0075] Example 3

[0076] Stretchable cooling patch K3:

[0077] The invention comprises a gel layer, which is prepared by using a gel solution; the gel solution is formulated by mass percentage as follows: 88.8% deionized water, 0.2% sodium tetraborate, 5% polyvinyl alcohol, 6% gelatin and 1% glycerol.

[0078] The preparation method of the stretchable cooling patch is as follows:

[0079] Step 1: preparing raw materials, including 10% by weight polyvinyl alcohol solution, 1% by weight sodium tetraborate solution, and 20% by weight gelatin solution;

[0080] Step 2: 10 ml of 10% polyvinyl alcohol, 6 ml of 20% gelatin and 0.2 ml of glycerol were heated and mixed at 50° C. to obtain a mixture 1;

[0081] Step 3: Mix the mixture 1 and 2 ml of 2% sodium tetraborate solution, and stir at 50 rpm for 1 min to obtain a gel solution;

[0082] Step 4: Inject the gel liquid into a circular mold container with a diameter of 5 cm to form a circular stretchable cooling patch K3 with a thickness of 4 cm and a diameter of 5 cm.

[0083] Example 4

[0084] Stretchable cooling patch K4:

[0085] The invention comprises a gel layer, which is prepared by using a gel solution; the gel solution has a formula of 88.8% deionized water, 0.2% sodium tetraborate, 10% polyvinyl alcohol, 6% gelatin and 1% glycerol in terms of mass percentage.

[0086] The preparation method of the stretchable cooling patch is as follows:

[0087] Step 1: preparing raw materials, including 20% ​​by weight polyvinyl alcohol solution, 2% by weight sodium tetraborate solution, and 20% by weight gelatin solution;

[0088] Step 2: 10 ml of 20% polyvinyl alcohol, 6 ml of 20% gelatin and 0.1 ml of glycerol were heated and mixed at 50° C. to obtain a mixture 1;

[0089] Step 3: Mix the mixture 1 and 2 ml of 2% sodium tetraborate solution, and stir at 50 rpm for 1 min to obtain a gel solution;

[0090] Step 4: Inject the gel liquid into a circular mold container with a diameter of 5 cm to form a circular stretchable cooling patch K4 with a thickness of 4 cm and a diameter of 5 cm.

[0091] Example 5

[0092] Stretchable cooling patch K5:

[0093] The invention comprises a gel layer, which is prepared by using a gel solution; the gel solution is formulated in terms of mass percentage: 88.8% deionized water, 0.2% sodium tetraborate, 5% polyvinyl alcohol, and 6% gelatin.

[0094] The preparation method of the stretchable cooling patch is as follows:

[0095] Step 1: prepare raw materials, including 10% by weight polyvinyl alcohol solution, 1% by weight sodium tetraborate solution, and 20% by weight gelatin solution;

[0096] Step 2: heating and mixing 10 ml of 10% polyvinyl alcohol and 6 ml of 20% gelatin at 50° C. to obtain a mixture 1;

[0097] Step 3: Mix the mixture 1 and 2 ml of 2% sodium tetraborate solution, and stir at 50 rpm for 1 min to obtain a gel solution;

[0098] Step 4: inject the gel solution into a circular mold container with a diameter of 5 cm to form a circular gel sheet with a thickness of 4 cm and a diameter of 5 cm;

[0099] Step 5: Soak the gel patch in a sodium sulfate solution with a mass percentage of 15% for 0.5 hours and then take it out to obtain the antipyretic patch K5.

[0100] Example 6

[0101] Stretchable cooling patch K6:

[0102] The invention comprises a gel layer, which is prepared by using a gel solution; the gel solution has a formula, in terms of mass percentage, of 88.8% deionized water, 0.4% sodium tetraborate, 5% polyvinyl alcohol, 6% gelatin, 0.1% menthol, 0.1% theobromine and 0.1% ethyl methyl p-hydroxybenzoate.

[0103] The preparation method of the stretchable cooling patch is as follows:

[0104] Step 1: preparing raw materials, including 10% by weight polyvinyl alcohol solution, 2% by weight sodium tetraborate solution, and 20% by weight gelatin solution;

[0105] Step 2: 10 ml of 10% polyvinyl alcohol, 0.2 mg of theobromine, 0.2 mg of menthol and 6 ml of 20% gelatin are heated and mixed at 50° C. to obtain a mixture 1;

[0106] Step 3: 0.2 mg of ethyl methyl p-hydroxybenzoate and 4 ml of 2% sodium tetraborate solution were mixed and stirred to obtain a mixture 2;

[0107] Step 4: Mix the mixture 1 and the mixture 2, and stir them at 50 rpm for 1 min to obtain a gel solution;

[0108] Step 5: Inject the gel solution into a circular mold container with a diameter of 5 cm to form a stretchable cooling patch K6 with a thickness of 4 cm and a diameter of 5 cm.

[0109] Comparative Example 1

[0110] Stretchable cooling patch K7: (cross-linking speed is too fast, forming speed is fast, bubbles are many, and the shape is poor)

[0111] The invention comprises a gel layer, which is prepared by using a gel solution; the gel solution is formulated by weight percentage as follows: 79.1% deionized water, 4.6% sodium tetraborate solution, 8.3% polyvinyl alcohol solution, and 8% gelatin solution.

[0112] The preparation method of the stretchable cooling patch is as follows:

[0113] Step 1: prepare raw materials, a polyvinyl alcohol solution with a mass percentage of 25%, and a sodium tetraborate solution with a mass percentage of 10%;

[0114] Step 2: 10 ml of 25% polyvinyl alcohol, 0.2 mg of theobromine, 0.2 mg of menthol and 6 ml of 40% gelatin solution are heated and mixed at 50° C. to obtain a mixture 1;

[0115] Step 3: 0.2 mg of ethyl methyl p-hydroxybenzoate and 14 ml of 10% sodium tetraborate solution were mixed and stirred to obtain a mixture 2;

[0116] Step 4: Stir mixture 1 and mixture 2 at 50 rpm for 1 min to obtain a gel solution;

[0117] Step 3: Inject the gel solution into a circular mold container with a diameter of 5 cm to form a stretchable cooling patch K7 with a thickness of 4 cm and a diameter of 5 cm.

[0118] Comparative Example 2

[0119] Stretchable cooling patch K8: (low cross-linking degree and difficult to shape)

[0120] The invention comprises a gel layer, which is prepared by using a gel solution; the gel solution is formulated in terms of mass percentage: 93.1% deionized water, 0.4% sodium tetraborate solution, 1.9% polyvinyl alcohol solution, and 4.6% gelatin solution.

[0121] The preparation method of the stretchable cooling patch is as follows:

[0122] Step 1: prepare raw materials, a polyvinyl alcohol solution with a mass percentage of 5%, and a sodium tetraborate solution with a mass percentage of 1%;

[0123] Step 2: 10 ml of 5% polyvinyl alcohol, 0.2 mg of theobromine, 0.2 mg of menthol and 6 ml of 20% gelatin solution are heated and mixed at 50° C. to obtain a mixture 1;

[0124] Step 3: 0.2 mg of ethyl methyl p-hydroxybenzoate and 10 ml of 1% sodium tetraborate solution were mixed and stirred to obtain a mixture 2;

[0125] Step 4: Stir mixture 1 and mixture 2 at 50 rpm for 1 min to obtain a gel solution;

[0126] Step 3: Inject the gel liquid into a circular mold container with a diameter of 5 cm to form a stretchable cooling patch K8 with a thickness of 4 cm and a diameter of 5 cm.

[0127] Comparative Example 3

[0128] Citation: The invention patent with publication number CN116672157A discloses a backing-free, high-water-content medical color-developing cooling patch, which belongs to the technical field of cooling patches. The cooling patch designed in this patent includes a first isolation membrane, a hydrogel layer, and a second isolation membrane distributed in layers, and a skeleton support layer is provided inside the hydrogel layer. The purpose of removing the backing layer in this patent is to increase the evaporation of water in the gel matrix, because the non-woven fabric substrate will prevent heat dissipation and will have a reverse "insulation" effect. However, the gel matrix of this patent has poor formability, so it is necessary to add a mesh cloth to the inside of the gel layer to support the skeleton, and the mesh cloth inside the gel will still limit the flexibility of the cooling patch. The purpose of removing the backing layer in the present invention is to remove the restriction of the backing layer on the elasticity of the cooling patch, and the gel has good formability, so there is no need to add a mesh cloth inside the gel.

[0129] Summary: Regarding the cited patent, the inventor believes that: although the patent has no backing, its gel layer also uses a mesh cloth to limit the flexibility of the cooling patch and still has no stretchability, which is different from the present application. The problem solved by the present application is to improve the stretchability of the cooling patch.

[0130] Comparative Example 4

[0131] Citation: For the invention patent with publication number CN117679241A, the present invention relates to the field of antipyretic patch technology, and specifically to a quick-acting antipyretic patch and its preparation method. The preparation raw materials include: 80-92% water, 0.1-1% chelating agent, 0.1-0.5% polyvinyl alcohol, 0.1-1% carbomer, 0.1-1% gum arabic, 0.1-1% carrageenan, 0.1-0.8% potassium chloride, 2-5% moisturizer, 0.05-0.5% disodium tetraborate, 0.08-0.4% preservative, 3-9% polymer, 0.2-1% cross-linking agent. The antipyretic patch matrix includes polyvinyl alcohol and sodium tetraborate, but its cross-linking method is not cross-linking of the two. And the proportion used is significantly different from that of the antipyretic patch.

[0132] Summary: Although the matrix of the cooling patch includes polyvinyl alcohol and sodium tetraborate, its cross-linking method is not the cross-linking of the two, and the proportion used is significantly different from that of the cooling patch, and it cannot be used to make the cooling patch of this patent.

[0133] Comparative Example 5

[0134] Citation: The invention patent with publication number CN11 6474154B discloses a hydrogel dressing band-aid for diabetic wounds, which belongs to the field of band-aid technology. The band-aid designed in this patent includes a waterproof layer, a protective layer, a gauze layer and a hydrogel layer. The preparation method of the hydrogel layer is: adding puerarin to water and mixing to obtain a mixed solution, then adding borax to the mixed solution and mixing to obtain a clear solution, adding polyvinyl alcohol to the clear solution and mixing to obtain a hydrogel layer. The matrix material of the hydrogel in this patent also adopts the method of cross-linking polyvinyl alcohol and borax, but the application field of this patent is the field of band-aids, and the application field is obviously different. In addition, the specific preparation method of this patent is different from that of the present invention. The polyvinyl alcohol concentration range of this application is 1 to 10wt%. The concentration is too low. For the antipyretic patch of the present invention, the polyvinyl alcohol concentration that is too low cannot be formed.

[0135] Summary: Regarding the cited patent, the inventor believes that: although the patent also uses polyvinyl alcohol and borax, the application field is completely different, and the specific formula ratio of the patent is different from that of the present invention, and it is impossible to make a product similar to the present invention through the process of the patent.

[0136] Comparative Example 6

[0137] Citation: For the invention patent with publication number CN112646206B, a highly transparent polyvinyl alcohol hydrogel is disclosed, which can also be used in the field of cooling patches. The hydrogel designed in this patent uses polyvinyl alcohol and inorganic salts as raw materials and water as solvent. Although this patent also uses polyvinyl alcohol as the matrix, its cross-linking method is to freeze-thaw the polyvinyl alcohol, which requires repeated freezing and thawing. The operation is cumbersome and requires large instruments. The cross-linking method of the present invention is to mix polyvinyl alcohol and cross-linking agent sodium tetraborate, and the two form boric acid bonds to form a hydrogel. The operation only requires simple stirring, no large instruments are required, and the operation is simple and convenient.

[0138] Summary: Regarding the cited patent, the inventor believes that: although the patent also uses polyvinyl alcohol, the cross-linking method is completely different. In addition, the patent only proposes the gel matrix of the cooling patch, and does not explain the components of the cooling patch; and the key of the present invention is the cooling patch without a backing, and the problem to be solved is to improve the stretchability of the cooling patch.

[0139] Performance Evaluation

[0140] 1. Evaluation of molding performance and adhesion performance

[0141] Test object: the above-mentioned stretchable cooling patch K1-8

[0142] Scoring index: Adhesion evaluation index is divided into: good (strong adhesion, can be easily attached to the skin surface, will not fall off with movement); general (average viscosity, can be attached to the skin, but will fall off with movement); poor (weak viscosity, difficult to adhere to the skin). Forming performance is divided into: good (gel cooling patch can be completely demolded); general (gel cooling patch can be demolded, but the gel eye patch has defects after demolding); poor (gel cooling patch cannot be completely demolded from the mold).

[0143] Evaluation method: Adhesion evaluation method: stick the following eight cooling patches on the forehead, joints, neck and other skin surfaces, and observe whether they will fall off within 30 minutes. Stick it on the joints and move to observe whether it will fall off with the movement. Formability evaluation method: In the preparation process of the following eight hydrogels, inject the hydrogel into the mold and let it stand for 30 minutes to observe the difficulty of demolding the hydrogel cooling patch, and whether the shape of the hydrogel cooling patch is intact after demolding, and whether there is any deformation or damage.

[0144] Table 1 Evaluation of the formability and adhesion of the cooling patch

[0145] Formability evaluation Adhesion performance evaluation K1 good good K2 good good K3 good good K4 good good K5 good good K6 good good K7 good Difference K8 Difference good

[0146] Examples K1-6 have good formability and adhesion, but in comparative example K7, since the polyvinyl alcohol concentration is 25% and the crosslinking agent concentration is 10%, the concentrations are too high, resulting in too rapid crosslinking, and the resulting cooling patch has poor morphology and poor adhesion. In comparative example K8, since the polyvinyl alcohol concentration is 10% and the crosslinking agent concentration is 1%, the concentrations are too low, and the resulting cooling patch cannot be formed and is difficult to demold. Due to the poor morphology of the cooling patches of comparative examples K7 and K8, K7 and K8 are no longer examined in subsequent cooling effect experiments, stretching ability experiments, and sensory evaluation experiments.

[0147] 2. Cooling effect test

[0148] Test objects: the above-mentioned stretchable cooling patch K1-6 and a certain brand of commercially available cooling patch.

[0149] The cooling patch was refrigerated at 4°C for 1 hour for pretreatment and then taken out. The cooling patch was applied to the skin surface of the subject's forehead at room temperature and a thermometer was used to record the skin surface temperature at the site of the gel patch after different periods of time.

[0150] Table 2 Cooling effect test of cooling patch

[0151]

[0152]

[0153] The test contents in Table 2 above can show that after the cooling patch of the present invention is used on the skin surface, the body surface temperature drops significantly, and has a good cooling effect. In addition, compared with the cooling patches available on the market, the cooling capacity is comparable.

[0154] 3. Stretchability

[0155] Test objects: the above-mentioned stretchable cooling patch K1-6 and a certain brand of commercially available cooling patch.

[0156] Test method: First, pre-treat the commercially available cooling patches and cut them into 5cm lengths. Then, fix the two ends of the following 7 groups of cooling patches and stretch them until the cooling patches are no longer stretchable or holes appear on their surface. And record the stretched length.

[0157] Table 3 Cooling patch tensile strength test

[0158] Stretched length (cm) / name of cooling patch K1 K2 K3 K4 K5 K6 Commercially available cooling patches Original length (cm) 5 5 5 5 5 5 5 Length after stretching (cm) 15 13 14 14 15 16 5.5

[0159] The length of the embodiment and the commercially available cooling patch before stretching was 5 cm, and the length of the commercially available cooling patch after stretching did not change significantly, indicating that its stretching performance was poor. The length of the embodiment K1, K2, K3, K4, K5, and K6 increased significantly after stretching, indicating that its stretching performance was excellent.

[0160] 4. Sensory evaluation

[0161] Test objects: the above-mentioned stretchable cooling patch K1-6 and a certain brand of commercially available cooling patch.

[0162] Evaluation method: Invite 5 volunteers to score the following 7 kinds of fever-reducing patches, and take the average value of the scores.

[0163] The scoring criteria are as follows: 0 points (no cooling sensation, poor comfort, poor flexibility); 1 point (partial cooling sensation, average comfort, average flexibility); 2 points (good cooling sensation, good comfort, good flexibility); 3 points (high cooling sensation, good comfort, good flexibility); the higher the score, the better the compliance, and the higher the score, the worse the compliance. (n=5).

[0164] Table 4 Sensory evaluation score sheet for antipyretic patch

[0165]

[0166]

[0167] The test results show that the cooling degree of this cooling patch is comparable to that of commercially available cooling patches, and its overall comfort is higher than that of commercially available cooling patches. Due to its backing-free design, this cooling patch is significantly more flexible than other cooling patches, and its overall user experience is better than that of commercially available cooling patches.

[0168] Although the above embodiment describes the present invention in detail, it is only a part of the embodiments of the present invention, not all of the embodiments. People can also obtain other embodiments based on this embodiment without creativity, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A dehydrating gel, characterized in that: The dehydrating gel is prepared from a polyvinyl alcohol solution, a gelatin solution and a sodium tetraborate solution; The mass percentage of the polyvinyl alcohol solution is 10-20%; The mass percentage of the gelatin solution is 20%; The mass percentage of the sodium tetraborate solution is 1-4%; The volume ratio of the polyvinyl alcohol solution, the gelatin solution and the sodium tetraborate solution is 3-10:1-5:1-10.

2. The dehydrating gel according to claim 1, characterized in that The dehydrating gel also includes glycerol, and the volume ratio of the polyvinyl alcohol solution to the glycerol is 2-8:0.

1.

3. The dehydrating gel according to claim 1, characterized in that The dehydrating gel also includes theobromine, menthol and ethyl methyl paraben; The mass ratio of the volume of the polyvinyl alcohol solution to the mass of theobromine, the mass of menthol, and the mass of ethyl methyl p-hydroxybenzoate is 3-5 ml: 0.1 g: 0.1 g: 0.1 g.

4. A method for preparing the dehydrating gel according to any one of claims 1 to 3, characterized in that: The following steps are involved: 1) mixing the polyvinyl alcohol solution and the gelatin solution to obtain a mixed solution; 2) mixing the mixed solution obtained in step 1) with the sodium tetraborate solution to obtain a gel solution; 3) forming the gel solution obtained in step 2) to obtain a dehydrating gel.

5. The preparation method according to claim 4, characterized in that: When the dehydrating gel further includes glycerol, the polyvinyl alcohol solution is mixed with the gelatin solution and glycerol to obtain a mixed solution.

6. The preparation method according to claim 4, characterized in that: When the dehydrating gel further comprises theobromine, menthol and ethyl methyl paraben, Mixing the polyvinyl alcohol solution with gelatin solution, theobromine and menthol to obtain a mixed solution; The mixed solution is mixed with the sodium tetraborate solution and ethyl methyl p-hydroxybenzoate to obtain a gel solution.

7. The preparation method according to any one of claims 4 to 6, characterized in that: After the gel solution is formed, it is immersed in a sodium sulfate solution for 30 minutes to obtain a dehydrated gel; The mass percentage of the sodium sulfate solution is 15%.

8. A hydrogel cooling patch, characterized in that: From top to bottom, there are an upper anti-adhesive layer, the dehydrating gel according to any one of claims 1 to 3, and a lower anti-adhesive layer.

9. The hydrogel cooling patch according to claim 8, characterized in that: The components of the upper anti-adhesive layer and the lower anti-adhesive layer are both medical embossed plastic films; The thickness of the dehydrating gel is 4 mm.

10. Use of the cooling water gel according to any one of claims 1 to 3 or the cooling water gel patch according to any one of claims 8 to 9 in the preparation of cooling water products.

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