Medical gel cold compress and preparation process thereof

Abstract

The present invention relates to the field of medical cold compress, specifically a medical gel cold compress and a preparation process thereof. The present invention uses trimethylolpropane as a raw material, controls the amount of reactants, first reacts with acryloyl chloride to obtain trimethylolpropane monoacrylate, then reacts the product with catechin acid, introduces double bonds and catechol structures, and retains a hydroxyl group; the hydroxyl group reacts with an isocyanate-terminated polyurethane prepolymer to obtain a double-bond-terminated polyurethane. The double-bond-terminated polyurethane is polymerized with acrylamide to obtain a polyurethane-modified acrylamide gel; the gel is soaked in a mixture of hydroxypropyl cellulose, glycerol, menthol, deionized water, tartaric acid, and sodium silicate, and coated on a non-woven fabric as a dressing, pressed with a polyethylene film, cut, solidified, and packaged to obtain a medical gel cold compress. The medical gel cold compress prepared by the present invention has high strength, high water absorption, and good adhesion performance, and can cool the affected tissue, assist in analgesia, and provide a comfortable feeling.

Description

Technical Field

[0001] The invention relates to the technical field of medical cold compress patches, in particular to a medical gel cold compress patch and a preparation process thereof. Background Art

[0002] Medical cold compress patch is a product used for local skin cooling and analgesia, cold compress therapy, and wound healing. By applying it to the skin surface, the intended purpose of treatment or auxiliary treatment is achieved. Compared with ice cold compress therapy, cold compress patch fits the human body better, especially the joints or body curves; in addition, ice needs to be frozen and stored, the temperature is too low, the comfort is not good, and the large weight and volume make it inconvenient to carry; while cold compress patch is light, does not take up space, can be carried with you, and is easy to use. The material of cold compress patch is usually polyacrylamide hydrogel. As a linear high molecular polymer with stable performance, polyacrylamide has problems such as low strength and poor adhesion to human skin tissue, which limits its application in the field of medical cold compress patch. Summary of the invention

[0003] The purpose of the present invention is to provide a medical gel cold compress and a preparation process thereof to solve the problems raised in the above background technology.

[0004] In order to solve the above technical problems, the present invention provides the following technical solutions: a medical gel cold compress and a preparation process thereof, comprising the following steps:

[0005] Step 1:

[0006] S11: Disperse trimethylolpropane in anhydrous tetrahydrofuran, add triethylamine and mix, cool to 0-5°C in an ice-water bath, stir for 0.5-1h, then drop acryloyl chloride within 30-45min, react for 12-15h, filter and wash to neutral after the reaction, extract and distill under reduced pressure to obtain trimethylolpropane monoacrylate;

[0007] S12: trimethylolpropane monoacrylate and catechin are mixed, a catalyst is added, and the temperature is raised to 70-85° C. under vacuum. The generated water is distilled off during the reaction. After reacting for 3-5 hours, the mixture is cooled and dry sodium carbonate is added to neutralize p-toluenesulfonic acid. The mixture is extracted and distilled under reduced pressure to obtain catechol-modified hydroxymethylpropane monoacrylate;

[0008] S13: dehydrating the raw materials, heating the polyethylene glycol to 70-80° C. under a nitrogen environment, dropping isophorone diisocyanate, keeping the temperature for reaction for 30-60 min, adding dibutyltin dilaurate, reacting for 1-2 h, adding dimethylolbutyric acid to the reaction system, continuing the reaction for 1-2 h, cooling the temperature to 50-60° C., adding 1,4-butanediol to the reaction system, adding acetone to adjust the viscosity of the reaction system, heating the temperature to 80-85° C. for reaction for 1-2 h, and obtaining an isocyanate-terminated polyurethane prepolymer;

[0009] S14: adding catechol-modified hydroxymethylpropane monoacrylate to the isocyanate-terminated polyurethane prepolymer, reacting at 70-80° C. for 30-40 minutes, then starting to cool down, and when the temperature drops to 40-45° C., adding salt-forming agent triethylamine for neutralization reaction, stirring for 10-15 minutes, and then adding deionized water for emulsification to obtain a double-bond-terminated polyurethane emulsion;

[0010] Step 2:

[0011] S21: mixing a double-bond terminated polyurethane emulsion and acrylamide, using potassium persulfate as an initiator, controlling the reaction temperature at 75-85° C. for 4-5 hours, cooling, dialyzing with deionized water, and drying to obtain polyurethane modified polyacrylamide;

[0012] S22: Take polyurethane modified polyacrylamide, hydroxypropyl cellulose, glycerin, menthol, deionized water, tartaric acid, and sodium silicate, mix and stir to obtain a hydrogel matrix; apply the hydrogel matrix to the coating surface of the non-woven fabric backing layer, press a polyethylene film on it, cut, solidify, and package to obtain a medical gel cold compress.

[0013] Furthermore, in S11, the molar ratio of trimethylolpropane, acryloyl chloride and triethylamine is (1.5-1.6):1:(2-2.5).

[0014] Furthermore, in S12, the molar ratio of trimethylolpropane monoacrylate to catechin is (1.2-1.3):1.

[0015] Furthermore, in S12, the catalyst is p-toluenesulfonic acid, and its usage is 1 to 1.5% of the total mass of the reactants.

[0016] Furthermore, in S13, the amount of each component in the isocyanate-terminated polyurethane prepolymer, by weight, is 18 to 22 parts of polyethylene glycol, 14 to 16 parts of isophorone diisocyanate, 0.8 to 1 part of dibutyltin dilaurate, 1.6 to 2.2 parts of dihydroxymethylbutyric acid, 1.5 to 2 parts of 1,4-butanediol, and 5 to 8 parts of acetone.

[0017] Furthermore, in S14, catechol-modified hydroxymethylpropane monoacrylate is added to the isocyanate-terminated polyurethane prepolymer at a molar ratio of hydroxymethyl to isocyanate (1.05-1.1):1.

[0018] Furthermore, in S14, the solid content of the double-bond terminated polyurethane emulsion is 60-70%.

[0019] Furthermore, in S21, 10-20% of double bond terminated polyurethane emulsion and 80-90% of acrylamide are mixed and reacted by weight to obtain polyurethane modified polyacrylamide.

[0020] Furthermore, in S22, the amounts of the components in the hydrogel matrix are, by weight, 15 to 20 parts of polyurethane modified polyacrylamide, 3 to 5 parts of hydroxypropyl cellulose, 5 to 7 parts of glycerol, 2 to 3 parts of menthol, 50 to 60 parts of deionized water, 0.5 to 1 part of tartaric acid, and 1 to 2 parts of sodium silicate.

[0021] Compared with the prior art, the beneficial effects achieved by the present invention are as follows: the present invention provides a medical gel cold compress with high strength and good adhesion. In order to improve the auxiliary therapeutic effect of the cold compress, the present invention adds glycerin, menthol, tartaric acid and other substances to the hydrogel matrix, wherein glycerin can have a moisturizing effect, menthol can be used to cool the surrounding damage of the affected tissue and assist in analgesia, and tartaric acid can adjust the pH value of the surface of the cold compress to make it weakly acidic and more skin-friendly, thereby improving the comfort of patients.

[0022] The present invention uses polyacrylamide as the main gel, and realizes the modification of polyacrylamide gel by polymerizing double-bond terminated polyurethane and acrylamide monomer. When preparing the double-bond terminated polyurethane, trimethylolpropane, a substance containing three hydroxyl groups, is used as a raw material, and first reacts with acryloyl chloride to obtain trimethylolpropane monoacrylate, and then the product is reacted with catechin to introduce double bonds and catechol structures. In the actual preparation process, since trimethylolpropane contains multiple hydroxyl groups, if it is reacted with acryloyl chloride in a molar ratio of 1:1, multiple double bonds may be grafted on a single trimethylolpropane molecule. Therefore, it is considered to make the reactant trimethylolpropane excessive, and let trimethylolpropane and acryloyl chloride react in a molar ratio of (1.5-1.6):1, so that acryloyl chloride is completely reacted, thereby improving the collection rate of the target product. Similarly, in the subsequent reaction, trimethylolpropane monoacrylate and catechin are reacted in a molar ratio of (1.2-1.3):1, and the target product obtained contains hydroxyl, double bond and catechol structure at the same time; the unreacted hydroxyl is reacted with isocyanate-terminated polyurethane prepolymer to obtain double-bond-terminated polyurethane. Since both ends of the polyurethane molecular chain contain double bonds, after the introduction of polyurethane, the double bond content in the system increases, the cross-linking sites become more, and the polyacrylamide changes from the original linear polymer to a mesh cross-linked polymer, the cross-linking degree of the gel is improved, and the water absorption and water retention rate of the gel increases. However, it should be noted that with the increase in the amount of double-bond polyurethane, the cross-linking degree of the hydrogel will further increase, the cross-linking network will be more dense, and it will be difficult for water molecules to enter the cross-linking network structure, resulting in a decrease in water absorption. In addition, when the amount of double-bond-terminated polyurethane is too high, the concentration of catechol therein also increases, and high concentrations of catechol are more easily oxidized, which reduces the adhesion of the hydrogel. Therefore, by weight percentage, the amount of the two is controlled to be 10-20% double-bond terminated polyurethane emulsion and 80-90% acrylamide, and the hydrogel obtained by polymerization has better performance. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0024] Materials and sources used in the present invention: polyethylene glycol with an average molecular weight of 1000 comes from Jiangsu Dena Chemical Co., Ltd.; polyethylene film comes from Foshan Xinjinfeng Technology Co., Ltd., item number 001, thickness 0.05 mm; non-woven fabric comes from Foshan Shangbaili New Materials Co., Ltd., item number KAM-02-A.

[0025] Embodiment 1: A preparation process of a medical gel cold compress comprises the following steps:

[0026] Step 1:

[0027] S11: Disperse trimethylolpropane in anhydrous tetrahydrofuran, add triethylamine and mix, cool to 0°C in an ice-water bath, stir for 0.5h, then dropwise add acryloyl chloride within 30min, react for 12h, filter and wash to neutrality after the reaction, extract and distill under reduced pressure to obtain trimethylolpropane monoacrylate; wherein the molar ratio of trimethylolpropane, acryloyl chloride and triethylamine is 1.5:1:2.1;

[0028] S12: trimethylolpropane monoacrylate and catechin are mixed in a molar ratio of 1.2:1, p-toluenesulfonic acid is added as a catalyst in an amount of 1% by weight of the total reactants, and the temperature is raised to 70° C. under vacuum. Water generated during the reaction is removed by distillation. After reacting for 3 hours, the mixture is cooled and dried sodium carbonate is added to neutralize the p-toluenesulfonic acid. The mixture is extracted and distilled under reduced pressure to obtain catechol-modified hydroxymethylpropane monoacrylate;

[0029] S13: Dehydrate the raw materials, raise the temperature of 20 g polyethylene glycol to 70° C. under a nitrogen environment, drop 14 g isophorone diisocyanate, keep the temperature for reaction for 30 min, add 1 g dibutyltin dilaurate, react for 1 h, then add 1.8 g dihydroxymethylbutyric acid to the reaction system, continue to react for 1 h, cool to 50° C., add 1.8 g 1,4-butanediol to the reaction system, add 6 g acetone to adjust the viscosity of the reaction system, raise the temperature to 80° C. and react for 1 h to obtain an isocyanate-terminated polyurethane prepolymer;

[0030] S14: adding catechol-modified hydroxymethylpropane monoacrylate to the isocyanate-terminated polyurethane prepolymer at a molar ratio of isocyanate group to hydroxymethyl group of 1:1.05, reacting at 70° C. for 30 min, then starting to cool down, and when the temperature drops to 40° C., adding salt-forming agent triethylamine for neutralization reaction, stirring for 10 min, and then adding deionized water for emulsification to obtain a double-bond-terminated polyurethane emulsion with a solid content of 65%;

[0031] Step 2:

[0032] S21: 10% double-bond terminated polyurethane and 90% acrylamide were mixed by weight percentage, potassium persulfate was used as an initiator, the reaction temperature was controlled at 75° C., the reaction was carried out under a nitrogen environment for 4 hours, and the mixture was cooled and dialyzed with deionized water to obtain polyurethane-modified polyacrylamide;

[0033] S22: Take 20g of polyurethane modified polyacrylamide, 4g of hydroxypropyl cellulose, 6g of glycerol, 3g of menthol, 60g of deionized water, 1g of tartaric acid, and 1.5g of sodium silicate, mix and stir to obtain a hydrogel matrix; apply the hydrogel matrix to the coating surface of the non-woven fabric backing layer, press a polyethylene film on it, cut, cure, and package to obtain a medical gel cold compress.

[0034] Embodiment 2: A preparation process of a medical gel cold compress patch, comprising the following steps:

[0035] Step 1:

[0036] S11: Disperse trimethylolpropane in anhydrous tetrahydrofuran, add triethylamine and mix, cool to 2°C in an ice-water bath, stir for 1 hour, then dropwise add acryloyl chloride within 40 minutes, react for 14 hours, filter and wash to neutrality after the reaction, extract and distill under reduced pressure to obtain trimethylolpropane monoacrylate; wherein the molar ratio of trimethylolpropane, acryloyl chloride and triethylamine is 1.5:1:2.1;

[0037] S12: trimethylolpropane monoacrylate and catechin are mixed in a molar ratio of 1.2:1, p-toluenesulfonic acid is added as a catalyst in an amount of 1% by weight of the total reactants, the temperature is raised to 75° C. under vacuum, water generated is removed by distillation during the reaction, the reaction is continued for 4 hours, the mixture is cooled, dry sodium carbonate is added to neutralize the p-toluenesulfonic acid, extraction is performed, and reduced pressure distillation is performed to obtain catechol-modified hydroxymethylpropane monoacrylate;

[0038] S13: Dehydrate the raw materials, raise the temperature of 20 g polyethylene glycol to 75° C. under a nitrogen environment, drop 14 g isophorone diisocyanate, keep the temperature for reaction for 45 min, add 1 g dibutyltin dilaurate, react for 1.5 h, add 1.8 g dihydroxymethylbutyric acid to the reaction system, continue to react for 1.5 h, cool to 55° C., add 1.8 g 1,4-butanediol to the reaction system, add 6 g acetone to adjust the viscosity of the reaction system, raise the temperature to 85° C. and react for 1.5 h to obtain an isocyanate-terminated polyurethane prepolymer;

[0039] S14: adding catechol-modified hydroxymethylpropane monoacrylate to the isocyanate-terminated polyurethane prepolymer at a molar ratio of isocyanate group to hydroxymethyl group of 1:1.05, reacting at 75° C. for 35 minutes, then starting to cool down, and when the temperature drops to 45° C., adding salt-forming agent triethylamine for neutralization reaction, stirring for 15 minutes, and then adding deionized water for emulsification to obtain a double-bond-terminated polyurethane emulsion with a solid content of 65%;

[0040] Step 2:

[0041] S21: 10% double-bond terminated polyurethane and 90% acrylamide were mixed by weight percentage, potassium persulfate was used as an initiator, the reaction temperature was controlled to 80° C., the reaction was carried out under a nitrogen environment for 4.5 hours, and the mixture was cooled and dialyzed with deionized water to obtain polyurethane-modified polyacrylamide;

[0042] S22: Take 20g of polyurethane modified polyacrylamide, 4g of hydroxypropyl cellulose, 6g of glycerol, 3g of menthol, 60g of deionized water, 1g of tartaric acid, and 1.5g of sodium silicate, mix and stir to obtain a hydrogel matrix; apply the hydrogel matrix to the coating surface of the non-woven fabric backing layer, press a polyethylene film on it, cut, cure, and package to obtain a medical gel cold compress.

[0043] Embodiment 3: A preparation process of a medical gel cold compress patch, comprising the following steps:

[0044] Step 1:

[0045] S11: Disperse trimethylolpropane in anhydrous tetrahydrofuran, add triethylamine and mix, cool to 5°C in an ice-water bath, stir for 1 hour, then dropwise add acryloyl chloride within 45 minutes, react for 15 hours, filter and wash to neutrality after the reaction, extract and distill under reduced pressure to obtain trimethylolpropane monoacrylate; wherein the molar ratio of trimethylolpropane, acryloyl chloride and triethylamine is 1.5:1:2.1;

[0046] S12: trimethylolpropane monoacrylate and catechin are mixed at a molar ratio of 1.2:1, p-toluenesulfonic acid is added as a catalyst in an amount of 1% by weight of the total reactants, and the mixture is heated to 85° C. under vacuum. Water generated during the reaction is removed by distillation. After reacting for 5 hours, the mixture is cooled and dried sodium carbonate is added to neutralize the p-toluenesulfonic acid. The mixture is extracted and distilled under reduced pressure to obtain catechol-modified hydroxymethylpropane monoacrylate;

[0047] S13: dehydrating the raw materials, heating 20 g of polyethylene glycol to 80° C. in a nitrogen environment, dropping 14 g of isophorone diisocyanate, keeping the temperature for reaction for 60 min, adding 1 g of dibutyltin dilaurate, reacting for 2 h, adding 1.8 g of dihydroxymethylbutyric acid to the reaction system, continuing the reaction for 2 h, cooling to 60° C., adding 1.8 g of 1,4-butanediol to the reaction system, adding 6 g of acetone to adjust the viscosity of the reaction system, heating to 85° C. for reaction for 2 h, and obtaining an isocyanate-terminated polyurethane prepolymer;

[0048] S14: adding catechol-modified hydroxymethylpropane monoacrylate to the isocyanate-terminated polyurethane prepolymer at a molar ratio of isocyanate group to hydroxymethyl group of 1:1.05, reacting at 80° C. for 40 minutes, then starting to cool down, and when the temperature drops to 45° C., adding salt-forming agent triethylamine for neutralization reaction, stirring for 15 minutes, and then adding deionized water for emulsification to obtain a double-bond-terminated polyurethane emulsion with a solid content of 65%;

[0049] Step 2:

[0050] S21: By weight percentage, 10% double-bond terminated polyurethane and 90% acrylamide were mixed, potassium persulfate was used as an initiator, the reaction temperature was controlled to 85° C., the reaction was carried out under a nitrogen environment for 5 hours, and the mixture was cooled and dialyzed with deionized water to obtain polyurethane-modified polyacrylamide;

[0051] S22: Take 20g of polyurethane modified polyacrylamide, 4g of hydroxypropyl cellulose, 6g of glycerol, 3g of menthol, 60g of deionized water, 1g of tartaric acid, and 1.5g of sodium silicate, mix and stir to obtain a hydrogel matrix; apply the hydrogel matrix to the coating surface of the non-woven fabric backing layer, press a polyethylene film on it, cut, cure, and package to obtain a medical gel cold compress.

[0052] Embodiment 4: A preparation process of a medical gel cold compress patch, comprising the following steps:

[0053] Step 1:

[0054] S11: Disperse trimethylolpropane in anhydrous tetrahydrofuran, add triethylamine and mix, cool to 0°C in an ice-water bath, stir for 1 hour, then drop acryloyl chloride within 35 minutes, react for 12 hours, filter and wash to neutrality after the reaction, extract and distill under reduced pressure to obtain trimethylolpropane monoacrylate; wherein the molar ratio of trimethylolpropane, acryloyl chloride and triethylamine is 1.5:1:2.1;

[0055] S12: trimethylolpropane monoacrylate and catechin are mixed in a molar ratio of 1.2:1, p-toluenesulfonic acid is added as a catalyst in an amount of 1% by weight of the total reactants, and the temperature is raised to 85° C. under vacuum. Water generated during the reaction is distilled off. After reacting for 3 hours, the mixture is cooled and dried sodium carbonate is added to neutralize the p-toluenesulfonic acid. The mixture is extracted and distilled under reduced pressure to obtain catechol-modified hydroxymethylpropane monoacrylate;

[0056] S13: Dehydrate the raw materials, raise the temperature of 20 g polyethylene glycol to 70° C. under a nitrogen environment, drop 14 g isophorone diisocyanate, keep the temperature for reaction for 35 min, add 1 g dibutyltin dilaurate, react for 2 h, then add 1.8 g dihydroxymethylbutyric acid to the reaction system, continue to react for 1 h, cool to 55° C., add 1.8 g 1,4-butanediol to the reaction system, add 6 g acetone to adjust the viscosity of the reaction system, raise the temperature to 85° C. and react for 1 h to obtain an isocyanate-terminated polyurethane prepolymer;

[0057] S14: adding catechol-modified hydroxymethylpropane monoacrylate to the isocyanate-terminated polyurethane prepolymer at a molar ratio of isocyanate group to hydroxymethyl group of 1:1.05, reacting at 75° C. for 40 minutes, then starting to cool down, and when the temperature drops to 45° C., adding salt-forming agent triethylamine for neutralization reaction, stirring for 10 minutes, and then adding deionized water for emulsification to obtain a double-bond-terminated polyurethane emulsion with a solid content of 65%;

[0058] Step 2:

[0059] S21: 13% double-bond terminated polyurethane and 87% acrylamide were mixed by weight percentage, potassium persulfate was used as an initiator, the reaction temperature was controlled at 85° C., the reaction was carried out under a nitrogen environment for 4 hours, and the mixture was cooled and dialyzed with deionized water to obtain polyurethane modified polyacrylamide;

[0060] S22: Take 20g of polyurethane modified polyacrylamide, 4g of hydroxypropyl cellulose, 6g of glycerol, 3g of menthol, 60g of deionized water, 1g of tartaric acid, and 1.5g of sodium silicate, mix and stir to obtain a hydrogel matrix; apply the hydrogel matrix to the coating surface of the non-woven fabric backing layer, press a polyethylene film on it, cut, cure, and package to obtain a medical gel cold compress.

[0061] Embodiment 5: A preparation process of a medical gel cold compress comprises the following steps:

[0062] Step 1:

[0063] S11: Disperse trimethylolpropane in anhydrous tetrahydrofuran, add triethylamine and mix, cool to 0°C in an ice-water bath, stir for 1 hour, then drop acryloyl chloride within 45 minutes, react for 12 hours, filter and wash to neutrality after the reaction, extract and distill under reduced pressure to obtain trimethylolpropane monoacrylate; wherein the molar ratio of trimethylolpropane, acryloyl chloride and triethylamine is 1.5:1:2.1;

[0064] S12: trimethylolpropane monoacrylate and catechin are mixed at a molar ratio of 1.2:1, p-toluenesulfonic acid is added as a catalyst in an amount of 1% by weight of the total reactants, and the mixture is heated to 85° C. under vacuum. Water generated during the reaction is removed by distillation. After reacting for 5 hours, the mixture is cooled and dried sodium carbonate is added to neutralize the p-toluenesulfonic acid. The mixture is extracted and distilled under reduced pressure to obtain catechol-modified hydroxymethylpropane monoacrylate;

[0065] S13: Dehydrate the raw materials, raise the temperature of 20 g polyethylene glycol to 75° C. under a nitrogen environment, drop 14 g isophorone diisocyanate, keep the temperature for reaction for 35 min, add 1 g dibutyltin dilaurate, react for 2 h, then add 1.8 g dihydroxymethylbutyric acid to the reaction system, continue to react for 1 h, cool to 60° C., add 1.8 g 1,4-butanediol to the reaction system, add 6 g acetone to adjust the viscosity of the reaction system, raise the temperature to 85° C. and react for 1 h to obtain an isocyanate-terminated polyurethane prepolymer;

[0066] S14: adding catechol-modified hydroxymethylpropane monoacrylate to the isocyanate-terminated polyurethane prepolymer at a molar ratio of isocyanate group to hydroxymethyl group of 1:1.05, reacting at 80° C. for 35 minutes, then starting to cool down, and when the temperature drops to 40° C., adding salt-forming agent triethylamine for neutralization reaction, stirring for 15 minutes, and then adding deionized water for emulsification to obtain a double-bond-terminated polyurethane emulsion with a solid content of 65%;

[0067] Step 2:

[0068] S21: 15% double-bond terminated polyurethane and 85% acrylamide were mixed by weight percentage, potassium persulfate was used as an initiator, the reaction temperature was controlled at 75° C., the reaction was carried out under a nitrogen environment for 5 hours, and the mixture was cooled and dialyzed with deionized water to obtain polyurethane-modified polyacrylamide;

[0069] S22: Take 20g of polyurethane modified polyacrylamide, 4g of hydroxypropyl cellulose, 6g of glycerol, 3g of menthol, 60g of deionized water, 1g of tartaric acid, and 1.5g of sodium silicate, mix and stir to obtain a hydrogel matrix; apply the hydrogel matrix to the coating surface of the non-woven fabric backing layer, press a polyethylene film on it, cut, cure, and package to obtain a medical gel cold compress.

[0070] Example 6: A preparation process of a medical gel cold compress, comprising the following steps:

[0071] Step 1:

[0072] S11: Disperse trimethylolpropane in anhydrous tetrahydrofuran, add triethylamine and mix, cool to 5°C in an ice-water bath, stir for 0.5h, then dropwise add acryloyl chloride within 45min, react for 13h, filter and wash to neutrality after the reaction, extract and distill under reduced pressure to obtain trimethylolpropane monoacrylate; wherein the molar ratio of trimethylolpropane, acryloyl chloride and triethylamine is 1.5:1:2.1;

[0073] S12: trimethylolpropane monoacrylate and catechin are mixed at a molar ratio of 1.2:1, p-toluenesulfonic acid is added as a catalyst in an amount of 1% by weight of the total reactants, and the mixture is heated to 85° C. under vacuum. Water generated during the reaction is removed by distillation. After reacting for 5 hours, the mixture is cooled and dried sodium carbonate is added to neutralize the p-toluenesulfonic acid. The mixture is extracted and distilled under reduced pressure to obtain catechol-modified hydroxymethylpropane monoacrylate;

[0074] S13: Dehydrate the raw materials, raise the temperature of 20 g polyethylene glycol to 70° C. under a nitrogen environment, drop 14 g isophorone diisocyanate, keep the temperature for reaction for 45 min, add 1 g dibutyltin dilaurate, react for 1.5 h, then add 1.8 g dihydroxymethylbutyric acid to the reaction system, continue to react for 1.5 h, cool to 60° C., add 1.8 g 1,4-butanediol to the reaction system, add 6 g acetone to adjust the viscosity of the reaction system, raise the temperature to 80° C. and react for 2 h to obtain an isocyanate-terminated polyurethane prepolymer;

[0075] S14: adding catechol-modified hydroxymethylpropane monoacrylate to the isocyanate-terminated polyurethane prepolymer at a molar ratio of isocyanate group to hydroxymethyl group of 1:1.05, reacting at 80° C. for 30 min, then starting to cool down, and when the temperature drops to 40° C., adding salt-forming agent triethylamine for neutralization reaction, stirring for 10 min, and then adding deionized water for emulsification to obtain a double-bond-terminated polyurethane emulsion with a solid content of 65%;

[0076] Step 2:

[0077] S21: By weight percentage, 20% double-bond terminated polyurethane and 80% acrylamide were mixed, potassium persulfate was used as an initiator, the reaction temperature was controlled to 85° C., the reaction was carried out under a nitrogen environment for 5 hours, and the mixture was cooled and dialyzed with deionized water to obtain polyurethane-modified polyacrylamide;

[0078] S22: Take 20g of polyurethane modified polyacrylamide, 4g of hydroxypropyl cellulose, 6g of glycerol, 3g of menthol, 60g of deionized water, 1g of tartaric acid, and 1.5g of sodium silicate, mix and stir to obtain a hydrogel matrix; apply the hydrogel matrix to the coating surface of the non-woven fabric backing layer, press a polyethylene film on it, cut, cure, and package to obtain a medical gel cold compress.

[0079] Comparative Example 1: Polyacrylamide was used instead of polyurethane-modified polyacrylamide, and the other parameters were the same as those in Example 1.

[0080] Step 1:

[0081] Add potassium persulfate initiator to acrylamide, control the reaction temperature to 75°C under nitrogen environment, react for 4 hours under nitrogen environment, cool and dialyze with deionized water to obtain polyurethane modified polyacrylamide;

[0082] Step 2:

[0083] Take 20g polyacrylamide, 4g hydroxypropyl cellulose, 6g glycerol, 3g menthol, 60g deionized water, 1g tartaric acid and 1.5g sodium silicate, mix and stir to obtain a hydrogel matrix; apply the hydrogel matrix to the coating surface of the non-woven fabric backing layer, press a polyethylene film on it, cut, solidify and package to obtain a medical gel cold compress.

[0084] Comparative Example 2: The amount of double-bond terminated polyurethane in S21 was increased, and the other parameters were the same as those in Example 2.

[0085] Step 1:

[0086] S11: Disperse trimethylolpropane in anhydrous tetrahydrofuran, add triethylamine and mix, cool to 2°C in an ice-water bath, stir for 1 hour, then dropwise add acryloyl chloride within 40 minutes, react for 14 hours, filter and wash to neutrality after the reaction, extract and distill under reduced pressure to obtain trimethylolpropane monoacrylate; wherein the molar ratio of trimethylolpropane, acryloyl chloride and triethylamine is 1.5:1:2.1;

[0087] S12: trimethylolpropane monoacrylate and catechin are mixed in a molar ratio of 1.2:1, p-toluenesulfonic acid is added as a catalyst in an amount of 1% by weight of the total reactants, the temperature is raised to 75° C. under vacuum, water generated is removed by distillation during the reaction, the reaction is continued for 4 hours, the mixture is cooled, dry sodium carbonate is added to neutralize the p-toluenesulfonic acid, extraction is performed, and reduced pressure distillation is performed to obtain catechol-modified hydroxymethylpropane monoacrylate;

[0088] S13: Dehydrate the raw materials, raise the temperature of 20 g polyethylene glycol to 75° C. under a nitrogen environment, drop 14 g isophorone diisocyanate, keep the temperature for reaction for 45 min, add 1 g dibutyltin dilaurate, react for 1.5 h, add 1.8 g dihydroxymethylbutyric acid to the reaction system, continue to react for 1.5 h, cool to 55° C., add 1.8 g 1,4-butanediol to the reaction system, add 6 g acetone to adjust the viscosity of the reaction system, raise the temperature to 85° C. and react for 1.5 h to obtain an isocyanate-terminated polyurethane prepolymer;

[0089] S14: adding catechol-modified hydroxymethylpropane monoacrylate to the isocyanate-terminated polyurethane prepolymer at a molar ratio of isocyanate group to hydroxymethyl group of 1:1.05, reacting at 75° C. for 35 minutes, then starting to cool down, and when the temperature drops to 45° C., adding salt-forming agent triethylamine for neutralization reaction, stirring for 15 minutes, and then adding deionized water for emulsification to obtain a double-bond-terminated polyurethane emulsion with a solid content of 65%;

[0090] Step 2:

[0091] S21: By weight percentage, 30% double-bond terminated polyurethane and 70% acrylamide were mixed, potassium persulfate was used as an initiator, the reaction temperature was controlled to 80° C., the reaction was carried out under a nitrogen environment for 4.5 hours, and the mixture was cooled and dialyzed with deionized water to obtain polyurethane-modified polyacrylamide;

[0092] S22: Take 20g of polyurethane modified polyacrylamide, 4g of hydroxypropyl cellulose, 6g of glycerol, 3g of menthol, 60g of deionized water, 1g of tartaric acid, and 1.5g of sodium silicate, mix and stir to obtain a hydrogel matrix; apply the hydrogel matrix to the coating surface of the non-woven fabric backing layer, press a polyethylene film on it, cut, cure, and package to obtain a medical gel cold compress.

[0093] Experiment: The hydrogel matrix and the medical gel cold compress prepared in Examples 1 to 6 and Comparative Examples 1 to 2 were subjected to performance tests, wherein:

[0094] Skin adhesion effect: Cut the pig skin into 1.5cm×6cm samples, wash them with ethanol and water, and dry them in a forced air drying oven at 30℃ for 15min. After taking them out, stick a 1.5cm×1.5cm medical gel cold compress on the surface of the pig skin, press them with a 200g weight for 5min, and measure the 180° peel strength with a universal tensile testing machine, setting the tensile speed to 20mm / min.

[0095] Water absorption rate: Dry the hydrogel matrix to constant weight, recorded as m0, and soak it in deionized water at 25°C for 2 hours. After taking it out, use filter paper to absorb excess water on the surface of the film and weigh it as m1. Water absorption rate = (m1-m0) / m0×100%.

[0096] Water absorption integrity: Cut a 10cm×10cm sample of the medical gel cold compress, soak it in deionized water at 25°C for 48 hours, draw a 10×10 square grid, calculate the area of ​​retained gel on the surface of the cold compress, and calculate the retention rate of the retained gel in the cold compress, which is the water absorption integrity of the cold compress.

[0097] project Adhesion strength / kPa Water absorption / % Water absorption integrity / % Example 1 3.4 322 98 Example 2 3.4 322 98 Example 3 3.5 323 98 Example 4 3.6 328 98 Example 5 3.8 332 99 Example 6 4.1 334 99 Comparative Example 1 1.6 289 87 Comparative Example 2 3.1 317 99

[0098] Conclusion: The data of Examples 1 to 6 show that the medical gel cold compress prepared by the present invention has good adhesion effect, high water absorption rate, high strength, and can maintain good integrity after long-term water absorption. As the amount of double-bond terminated polyurethane increases, various performances are also improved. Combining the data of Examples 1 to 6 and Comparative Examples 1 to 2, it can be seen that compared with Comparative Example 1, after the double-bond terminated polyurethane is introduced into the polyacrylamide in Examples 1 to 6, the performance of the gel cold compress is improved; compared with Comparative Example 2, as the amount of double-bond terminated polyurethane prepolymer continues to increase, the bonding strength and water absorption of the cold compress first increase, and then decrease.

[0099] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein by equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A preparation process of a medical gel cold compress, characterized in that: The following steps are involved: S11: Disperse trimethylolpropane in anhydrous tetrahydrofuran, add triethylamine and mix, cool to 0-5°C in an ice-water bath, stir for 0.5-1h, then drop acryloyl chloride within 30-45min, react for 12-15h, filter and wash to neutral after the reaction, extract and distill under reduced pressure to obtain trimethylolpropane monoacrylate; S12: trimethylolpropane monoacrylate and catechin are mixed, a catalyst is added, and the temperature is raised to 70-85° C. under vacuum. The generated water is distilled off during the reaction. After reacting for 3-5 hours, the mixture is cooled and dry sodium carbonate is added to neutralize p-toluenesulfonic acid. The mixture is extracted and distilled under reduced pressure to obtain catechol-modified hydroxymethylpropane monoacrylate; S13: dehydrating the raw materials, heating the polyethylene glycol to 70-80° C. under a nitrogen environment, dropping isophorone diisocyanate, keeping the temperature for reaction for 30-60 min, adding dibutyltin dilaurate, reacting for 1-2 h, adding dimethylolbutyric acid to the reaction system, continuing the reaction for 1-2 h, cooling the temperature to 50-60° C., adding 1,4-butanediol to the reaction system, adding acetone to adjust the viscosity of the reaction system, heating the temperature to 80-85° C. for reaction for 1-2 h, and obtaining an isocyanate-terminated polyurethane prepolymer; S14: adding catechol-modified hydroxymethylpropane monoacrylate to the isocyanate-terminated polyurethane prepolymer, reacting at 70-80° C. for 30-40 minutes, then starting to cool down, and when the temperature drops to 40-45° C., adding salt-forming agent triethylamine for neutralization reaction, stirring for 10-15 minutes, and then adding deionized water for emulsification to obtain a double-bond-terminated polyurethane emulsion; Step 2: S21: mixing a double-bond terminated polyurethane emulsion and acrylamide, using potassium persulfate as an initiator, controlling the reaction temperature at 75-85° C. for 4-5 hours, cooling, dialyzing with deionized water, and drying to obtain polyurethane modified polyacrylamide; S22: Take polyurethane modified polyacrylamide, hydroxypropyl cellulose, glycerin, menthol, deionized water, tartaric acid, and sodium silicate, mix and stir to obtain a hydrogel matrix; apply the hydrogel matrix to the coating surface of the non-woven fabric backing layer, press a polyethylene film on it, cut, solidify, and package to obtain a medical gel cold compress.

2. The preparation process of the medical gel cold compress according to claim 1, characterized in that: In S11, the molar ratio of trimethylolpropane, acryloyl chloride and triethylamine is (1.5 to 1.6):1:(2 to 2.5).

3. The preparation process of the medical gel cold compress according to claim 1, characterized in that: In S12, the molar ratio of trimethylolpropane monoacrylate to catechin is (1.2-1.3):

1.

4. The preparation process of the medical gel cold compress according to claim 1, characterized in that: In S12, the catalyst is p-toluenesulfonic acid, and its usage is 1 to 1.5% of the total mass of the reactants.

5. The preparation process of the medical gel cold compress according to claim 1, characterized in that: In S13, the amount of each component in the isocyanate-terminated polyurethane prepolymer, by weight, is 18 to 22 parts of polyethylene glycol, 14 to 16 parts of isophorone diisocyanate, 0.8 to 1 part of dibutyltin dilaurate, 1.6 to 2.2 parts of dihydroxymethylbutyric acid, 1.5 to 2 parts of 1,4-butanediol, and 5 to 8 parts of acetone.

6. The preparation process of the medical gel cold compress according to claim 1, characterized in that: In S14, catechol-modified hydroxymethylpropane monoacrylate is added to the isocyanate-terminated polyurethane prepolymer at a molar ratio of hydroxymethyl group to isocyanate group (1.05-1.1):

1.

7. The preparation process of the medical gel cold compress according to claim 1, characterized in that: In S14, the solid content of the double-bond terminated polyurethane emulsion is 60-70%.

8. The preparation process of the medical gel cold compress according to claim 1, characterized in that: In S21, 10-20% of double bond terminated polyurethane emulsion and 80-90% of acrylamide are mixed and reacted to obtain polyurethane modified polyacrylamide, based on weight percentage.

9. The preparation process of the medical gel cold compress according to claim 1, characterized in that: In S22, the amounts of the components in the hydrogel matrix are, by weight, 15 to 20 parts of polyurethane-modified polyacrylamide, 3 to 5 parts of hydroxypropyl cellulose, 5 to 7 parts of glycerol, 2 to 3 parts of menthol, 50 to 60 parts of deionized water, 0.5 to 1 part of tartaric acid, and 1 to 2 parts of sodium silicate.

10. A medical cold compress patch prepared by the preparation process of a medical gel cold compress patch according to any one of claims 1 to 9.