A versatile and breathable water-based coating for medical tape and its preparation method.

Abstract

This invention discloses a versatile and breathable water-based coating for medical tape, comprising acrylate monomers, an emulsifier, an initiator, and a silicone resin. The emulsifier is 0.1-1% anionic or a combination of anionic and no more than 0.5% nonionic emulsifiers. The initiator is 0.05-0.8% a water-soluble oxidant, or a combination of a water-soluble oxidant and 0.01-0.5% a reducing agent. The acrylate monomer comprises 30-65% soft monomers, 30-65% hard monomers, and 1-5% functional monomers. The coating of this invention combines release properties, writeability, breathability, and skin comfort, thus eliminating the need for an additional silicone release layer. In the synthesis process, a water-based acrylate emulsion is first prepared, then a solvent-free silicone release agent is added, causing the acrylate layer to encapsulate the liquid silicone release agent. The reaction is then heated to form an interpenetrating network structure with the acrylate layer. After the reaction, the temperature is lowered to form the finished product.

Description

Technical Field

[0001] This invention relates to the field of medical tape technology, and more specifically, to a versatile and breathable water-based coating for medical tape and its preparation method. Background Technology

[0002] The release layer design of commercially available medical cloth or non-woven fabric adhesive tapes often neglects the needs for writeability and breathability. Specifically, PE lamination and pure silicone release layers, due to their excellent barrier properties, result in poor breathability. Acrylic or polyurethane resin coatings, if made too soft, tend to be sticky; if made too hard, they feel stiff and lack skin comfort.

[0003] In existing technologies, textile adhesive tapes typically employ two methods: one is to coat the textile material with a PE film, followed by a layer of silicone release agent; the other is to coat the textile material with an acrylic or polyurethane coating as a primer and release layer, followed by a layer of silicone release agent. While both methods can meet the release requirements of the tape, they have the following drawbacks: Non-writable surface: The surface tension of a pure silicone release layer is too low, making it impossible to write with a ballpoint pen or ink pen, which is inconvenient for recording information. In medical, office and other scenarios, tapes often need to have information recording functions, such as patient information, usage dates, etc., so writability is crucial.

[0004] Poor breathability: The use of PE film or barrier coating with release agent severely hinders gas permeation, reducing the comfort of the tape, especially when worn for a long time, which can easily cause skin discomfort.

[0005] Hard to the touch: Ordinary acrylic or polyurethane barrier coatings have a hard feel and lack skin comfort, which affects the overall user experience of the tape. Summary of the Invention

[0006] This invention aims to develop a water-based acrylic silicone emulsion coating for use as a release coating on textile tapes, enabling it to combine release properties, writability, breathability, and skin comfort, thus eliminating the need for an additional silicone release layer. Based on this, a versatile and breathable water-based coating for medical tapes is provided.

[0007] Another object of the present invention is to provide a method for preparing the above-mentioned coating.

[0008] To achieve the above objectives, the specific technical solution adopted by the present invention is as follows: The present invention This invention synthesizes an aqueous acrylate emulsion with good dispersibility, capable of encapsulating silicone oil to form an emulsion. After film formation and drying, the emulsion exhibits high surface tension while maintaining a certain degree of air permeability. The specific components include anionic or nonionic emulsifiers, common acrylate film-forming monomers, acrylate functional monomers, initiators, neutralizing agents, defoamers, and preservatives.

[0009] In the synthesis process, an aqueous acrylate emulsion is first prepared, and then a portion of the emulsion is neutralized. Under high-speed stirring and dispersion, a well-mixed three-component solvent-free silicone release agent is slowly added to the neutralized acrylate emulsion, allowing the acrylate layer to encapsulate the liquid silicone release agent. The mixture is then heated to allow the silicone release resin encapsulated within the acrylate resin to react and form an interpenetrating network structure with the acrylate layer. After the reaction is complete, the temperature is lowered to form the desired aqueous acrylate-silicone release resin.

[0010] The specific plan is as follows: A versatile and breathable water-based coating for medical tape includes acrylate monomers, emulsifiers, initiators, and silicone resins; The emulsifier is anionic or a combination of anionic and nonionic emulsifiers, wherein the amount used, calculated by solids content, is: 0.1-1% for anionic emulsifier and no more than 0.5% for nonionic emulsifier; The initiator is a water-soluble oxidant, or a combination of a water-soluble oxidant and a reducing agent, wherein the amount used, calculated by solids, is: 0.05-0.8% water-soluble oxidant and 0.01-0.5% reducing agent; The balance of the acrylic monomer, emulsifier, and initiator is the amount of silicone resin used; The acrylic monomers include soft monomers, hard monomers, and functional monomers for improving air permeability. The soft monomers include butyl acrylate, ethyl acrylate, or isooctyl acrylate. The hard monomers include methyl acrylate, methyl methacrylate, vinyl acetate, or styrene. The functional monomers include acidic monomers, hydrophilic acrylate monomers, organosilicon crosslinking monomers, or crosslinking monomers. The dosage based on solids is: soft monomers 30-65%, hard monomers 30-65%, and functional monomers 1-5%.

[0011] Preferably, the emulsifier comprises one or more of dodecylbenzene sulfonate, dodecyl / hexadecyl ether sulfate, allyl alkyl alcohol sulfate, fatty alcohol polyoxyethylene ether sulfate / phosphate, fatty alcohol polyoxyethylene ether sulfosuccinate, or fatty alcohol polyoxyethylene ether.

[0012] Preferably, the acidic monomer is one or more of acrylic acid, methacrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, itaconic acid, β-carboxyethylacrylic acid, fumarate monoester, maleic acid and its monoester derivatives, or sodium vinyl sulfonate.

[0013] Preferably, the hydrophilic monomer is one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, polyethylene glycol acrylate, or methoxy polyethylene glycol acrylate; and its amount, calculated by solids, is 2-5%.

[0014] Preferably, the organosilicon crosslinking monomer is one or more of vinyltrimethoxysilane and its derivatives, methacryloyloxypropyltrimethoxysilane and its derivatives, diacetone acrylamide, AAEM (acetyl acetoxyethyl methacrylate) and ADH (adipic hydrazide), diallyl phthalate, diallyl maleate, dipropylene glycol diacrylate, or hydroxymethylacrylamide.

[0015] Preferably, the water-soluble oxidant is one or more of sodium persulfate, ammonium persulfate, or potassium persulfate; the reducing agent is one or more of sodium sulfite, sodium formaldehyde sulfoxylate, vitamin C, or ferrous sulfate.

[0016] Preferably, the versatile and breathable water-based coating of the medical tape further includes tert-butyl hydroperoxide as an oxidant for removing residues and reducing odor, or sodium formaldehyde sulfoxylate or vitamin C as a reducing agent.

[0017] Preferably, the versatile and breathable water-based coating of the medical tape further includes an alkali for neutralization, including: ammonia, organic amine sodium hydroxide or potassium hydroxide, wherein the organic amine is generally one or more of AMP95 (2-amino-2-methyl-1-propanol), dimethylethanolamine, diethanolamine, triethanolamine, polyetheramine, polyethylene polyamine, or amino acids containing an amino group.

[0018] A method for preparing a versatile and breathable water-based coating for medical adhesive tape: The acrylic monomer, emulsifier, and initiator using only a water-soluble oxidant are reacted by adding the monomer pre-emulsion and initiator dropwise at a temperature of 78-88°C; or the initiator is used in combination with both a reducing agent and an oxidizing agent, and the dropwise reaction temperature is reduced to 65-78°C. Take the above-synthesized acrylic emulsion and add it into a high-speed dispersion device. Under high-speed stirring, slowly add organosilicon resin over a period of 10 to 60 minutes. Control the temperature at 20-40°C. While adding the resin, slowly add water according to the viscosity to control the viscosity to be no lower than 5000 cps and no higher than 1,000,000 cps. After the silicone resin is added, continue to disperse at a high speed of over 1500 rpm (1500-3000 rpm can be used) for 10-30 minutes, then reduce the stirring speed to below 1000 rpm (400-800 rpm can be used), dilute with water to a viscosity of 100-1000 cps, and then slowly raise the temperature to 60-80℃ after 1-2 hours. Slowly maintain the temperature for 3 hours while stirring at 400-800 rpm until the reaction is complete. Cool down and discharge the material. Any silicone resin that has not fully reacted can be reacted at room temperature after cooling.

[0019] Preferably, after the dropwise addition reaction is completed, tert-butyl hydroperoxide is used as an oxidant, or sodium formaldehyde sulfoxylate or vitamin C is used as a reducing agent to remove residual odor.

[0020] Preferably, after the emulsion synthesis is completed, the resulting semi-finished product is a milky white water-based acrylate emulsion; neutralization is performed using ammonia, organic amine sodium hydroxide, or potassium hydroxide alkali.

[0021] Preferably, after the synthesis is completed, the temperature is cooled to below 40°C, and an antifoaming agent and a preservative are added.

[0022] The relatively high content of acidic acrylic monomers in the composition of this invention improves the dispersibility and high viscosity of the neutralized high-viscosity silicone resin. Hydrophilic functional monomers provide water vapor permeability. In addition to grafting onto the acrylate polymer chains, the silicone crosslinking monomers can further crosslink with the solvent-free silicone resin to form an interpenetrating network structure, improving the compatibility between acrylates and silicone. Furthermore, the crosslinked silicone monomers can form a small number of pores, improving air permeability. Other crosslinking agents can improve cohesive strength, chemical resistance, scratch resistance, and adhesion to the substrate. Neutralizing agents can increase the viscosity of the emulsion and improve dispersion performance. The silicone resin is a high-viscosity, solvent-free, reactive release agent resin, which can be classified as either condensation-type or addition-type liquid silicone resin. After mixing, it must be a liquid silicone resin that can react at a low temperature below 80°C.

[0023] Based on this, the addition of solvent-free organosilicon resin in the preparation method of the present invention allows the process to form an acrylate-organosilicon copolymer emulsion simply by crosslinking through interpenetrating blending networks, without the need for complex emulsion synthesis. This method is simple, efficient, and highly adaptable to different formulations. Detailed Implementation

[0024] The present invention will be further explained and described below through specific embodiments. It should be understood that the purpose of the following embodiments is to make the technical solution of the present invention clearer and easier to understand, and does not limit the scope of protection of the claims.

[0025] The present invention will be further described below through specific embodiments.

[0026] The technical framework of this invention is as follows: 1) The emulsifier used in the emulsion of this invention is anionic or nonionic emulsifier, such as dodecylbenzene sulfonate, dodecyl / hexadecyl ether sulfate, allyl alkyl alcohol sulfate, fatty alcohol polyoxyethylene ether sulfate / phosphate, fatty alcohol polyoxyethylene ether sulfosuccinate, fatty alcohol polyoxyethylene ether (nonionic emulsifier with a number of 4 to 40 E0), etc., wherein at least one anionic emulsifier is used in an amount of 0.1 to 1% (calculated based on solids), and the nonionic emulsifier is used in an amount of 0 to 0.5% (calculated based on solids).

[0027] 2) The acrylate monomers used in this invention are butyl acrylate, ethyl acrylate, and isooctyl acrylate as soft monomers, and are used in combination with methyl acrylate, methyl methacrylate, vinyl acetate, and styrene as hard monomers. In addition, a small amount of functional monomers are also required. Among them, butyl acrylate, ethyl acrylate, and isooctyl acrylate together account for 30-65% of the total monomer content, and the other hard monomers account for 30-65%.

[0028] 3) The functional monomers used in this invention are classified into acidic monomers, hydrophilic acrylate monomers, organosilicon crosslinking monomers, and other crosslinking monomers. Acidic monomers are generally acrylic acid, methacrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, itaconic acid, β-carboxyethyl acrylic acid, fumaric acid monoester, maleic acid and its monoester derivatives (such as monobutyl maleate), sodium vinyl sulfonate, etc. Acidic monomers can be used in combination, generally accounting for 1-5% of the total monomers. Hydrophilic monomers are generally hydroxyethyl acrylate, hydroxyethyl methacrylate, polyethylene glycol acrylate or methoxy polyethylene glycol acrylate, etc., and their usage generally accounts for 2-5% of the total monomers. Organosilicon crosslinking monomers are generally vinyltrimethoxysilane and its derivatives, methacryloyloxypropyltrimethoxysilane and its derivatives, other acrylic crosslinking monomers such as diacetone acrylamide or AAEM (these two only need to be used with ADH, etc.), diallyl phthalate, diallyl maleate, dipropylene glycol diacrylate, hydroxymethylacrylamide, etc., and their usage is generally 1-5% of the monomers.

[0029] 4) The initiator used in emulsion synthesis is generally a water-soluble oxidant, mainly a persulfate, such as sodium persulfate, ammonium persulfate, or potassium persulfate; the amount used is generally 0.05-0.8% of the monomer amount; the monomer pre-emulsion and initiator are added dropwise, and the dropwise reaction temperature is 78-88℃; the initiator can also be used in combination with a reducing agent and an oxidant, such as sodium sulfite, sodium formaldehyde sulfoxylate, vitamin C, ferrous sulfate, etc., with a amount of 0.01-0.5%. When a reducing agent is used together, the dropwise reaction temperature is reduced to 65-78℃.

[0030] 5) After the dropwise reaction is complete, tert-butyl hydrogen peroxide can be used as an oxidant, and sodium formaldehyde sulfoxylate or vitamin C can be used as a reducing agent to remove residues and reduce odor.

[0031] 6) After emulsion synthesis, the resulting semi-finished product is a milky white water-based acrylate emulsion. Neutralization can be achieved using alkalis such as ammonia, organic amine sodium hydroxide, or potassium hydroxide. The organic amine is generally AMP95, dimethylethanolamine, diethanolamine, triethanolamine, polyetheramine, polyethylenepolyamine, amino acids containing amino groups, or other organic amine compounds.

[0032] 7) After the synthesis is complete, cool the temperature to below 40°C and add defoamer and preservative. The defoamer is a commercially available mineral oil or silicone defoamer for conventional water-based emulsions. The preservative can be a commercially available model for conventional water-based emulsions.

[0033] 8) Take a portion of the synthesized acrylic emulsion and add it to a high-speed dispersion device. While stirring at high speed, slowly add solvent-free multi-component liquid silicone resin over approximately 10-60 minutes, maintaining a temperature of 20-40°C. Simultaneously, add a small amount of water dropwise according to the viscosity, ensuring the viscosity does not fall below 5000 cps or exceed 1,000,000 cps. The amount of acrylic resin is typically 20-80% (solids content), with the remaining component being silicone resin. After the silicone resin is added, continue high-speed dispersion for another 10-30 minutes, then reduce the stirring speed and dilute with water to a viscosity of 100-1000 cps. Slowly raise the temperature to 60-80°C and maintain this temperature for 3 hours with slow stirring until the reaction is complete. Cool down and discharge the material. Any unreacted silicone resin can be allowed to react slowly at room temperature after cooling. The silicone resin mentioned is generally a commercially available three-component solvent-free silicone release resin, such as SZ401 silicone resin / SJ201 crosslinking agent / SC51 catalyst or SZ296 silicone resin / SJ29 crosslinking agent / SC51 catalyst from Guangzhou Chemical Co., Ltd., Chinese Academy of Sciences, with a ratio generally around 100 / 3 / 1.0~1.5. The three-component silicone release resin is mixed before use, and should generally be used within 8 hours of mixing.

[0034] It should be noted that: The writeability in this invention is primarily achieved through a unique structure where acrylic resin forms the shell, encapsulating an internally cross-linked silicone resin core. When the water in the emulsion evaporates, the latex particles form a film with the acrylic shell facing outwards and most of the silicone resin in the middle. Acrylic resin is a highly polar resin with a high dyne value, which meets the requirements for writing. Pure silicone resin, on the other hand, has a low dyne value and is not writeable.

[0035] In this invention, the breathability mainly comes from the silicone resin. The silicone resin has a Si-O-Si structure with a large free volume, allowing gas molecules to pass through. At the same time, due to its good hydrophobicity, water molecules cannot pass through, thus achieving the effect of being breathable yet waterproof.

[0036] Organosilicon resin is a two-component or three-component organosilicon resin that can react at room temperature. In this way, the organosilicon resin can undergo internal cross-linking after being encapsulated in acrylate latex particles.

[0037] Organosilicon resins with similar functions as described above typically include condensation-type and addition-type organosilicon resins.

[0038] Condensation-type silicone resins mainly consist of hydroxyl silicone oil, and the matching crosslinking agents are generally silane coupling agents, such as 3-propyltriethoxysilane, epoxytriethoxysilane, tetraethyl orthosilicate or methylethoxysilane, etc., and the matching catalysts are such as dibutyltin dilaurate, etc.

[0039] Addition-type silicone resins include vinyl silicone oil as the main component, hydrogen-containing silicone oil as the crosslinking agent, and platinum catalysts as the catalysts. Example

[0040] Take 0.6 g of sodium dodecylbenzenesulfonate (23% content) as the emulsifier, dissolve it in 2 g of pure water, and then add it to the pre-emulsification vessel. Start stirring, and slowly add 25 g of butyl acrylate, 25 g of methyl methacrylate, 1 g of acrylic acid, 2 g of hydroxyethyl acrylate, 0.5 g of vinyltrimethoxysilane, and 0.5 g of diallyl maleate to the pre-emulsification vessel while stirring rapidly. Emulsify for at least half an hour to pre-emulsify the acrylate monomers into a milky white pre-emulsion and set it aside. Then add 35 g of pure water and 0.1 g of sodium bicarbonate buffer to the reaction vessel, start stirring, and heat to about 80°C. Then add 0.08 g of ammonium persulfate initiator to the reaction vessel. After 5 minutes, start adding the prepared pre-emulsion to the reaction vessel at a uniform rate over 4 hours. Weigh out 0.1 g of ammonium persulfate and dissolve it in 2 g of water. Then, while the pre-emulsion is being added dropwise, slowly and uniformly add the ammonium persulfate solution into the reactor over a period of 4.15 hours. Maintain a constant reaction temperature of 80-84℃ in the reactor. After the addition is complete, maintain the temperature at 80-86℃ for 1 hour. Then, cool the reactor to about 65℃. Weigh 0.05 g of tert-butyl hydrogen peroxide (70%), dilute it with 0.1 g of water, and slowly add it to the reactor over about 15 minutes. At the same time, weigh 0.05 g of sodium formaldehyde sulfoxylate and dilute it with 0.1 g of pure water. Add it to the reactor over 15 minutes immediately after the tert-butyl hydrogen peroxide solution is added. After the sodium formaldehyde sulfoxylate solution is added, maintain the temperature for half an hour. Then, cool the reactor to about 40℃ and add 0.8 g of ammonia (25%), 0.1 g of mineral oil defoamer (BASF Foamaster MO 2190), 0.1 g of preservative (20% BIT), and 4.82 g of water. After stirring, test the pH to be about 7.5 and the viscosity to be about 8000 cps. Filter and discharge the material. Take 100g of the cooled acrylic emulsion and put it into a high-speed disperser. Start stirring at 1500rpm. Then, mix 104g of SZ401 silicone resin, SJ201 crosslinking agent, and SC51 catalyst in a ratio of 100 / 3 / 1 from Guangzhou Chemical Co., Ltd., Chinese Academy of Sciences. Slowly add the mixture to the neutralized acrylic emulsion over 20 minutes. At the same time, take 20g of water and slowly add it dropwise to the high-speed dispersion vessel while adding the silicone resin. Maintain the viscosity of the emulsion in the vessel within the range of 5000-1000000cps. After adding the water, continue to increase the high-speed dispersion to 2000rpm for 10 minutes. Then, add 100g of water to dilute to a viscosity of about 200cps. Reduce the stirring speed and slowly heat the reaction vessel to about 60℃. Maintain the temperature for 3 hours before cooling and discharging. When this emulsion is coated and made into textile tape, its surface can be written on with ballpoint pens or ink pens without shrinkage, has a release force of 3N / 25mm, a comfortable feel against the skin, and a water vapor permeability of ≥ 500 g / m²·24h. Example

[0041] Take 0.6 g of sodium allyl isoalkyl alkyl sulfate (23% content) as the emulsifier, dilute and dissolve it with 2 g of pure water, and then add it to the pre-emulsification vessel. Start stirring, and slowly add 35 g of butyl acrylate, 5 g of vinyl acetate, 10 g of methyl methacrylate, 1.5 g of methacrylic acid, 2 g of polyethylene glycol monoacrylate (400 molecular weight specification), 0.5 g of methacryloxypropyltrimethoxysilane, and 1 g of 48% N-hydroxymethylacrylamide to the pre-emulsification vessel while stirring rapidly. Emulsify for more than half an hour to pre-emulsify the acrylate monomers into a milky white pre-emulsion and set it aside. Then add 35 g of pure water and 0.1 g of sodium bicarbonate buffer to the reaction vessel, start stirring, and heat to about 80°C. Then add 0.08 g of ammonium persulfate initiator to the reaction vessel, and simultaneously add 3% of the above pre-emulsion to the bottom of the vessel. After 15 minutes, the remaining pre-emulsion was added dropwise to the reactor at a uniform rate over 3.5 hours. Then, 0.1 g of ammonium persulfate was weighed and dissolved in 2 g of water. Simultaneously with the addition of the pre-emulsion, the ammonium persulfate solution was slowly and uniformly added dropwise to the reactor over 3.7 hours. The reaction temperature in the reactor was kept constant at 80-84℃. After the addition is complete, maintain the temperature at 80-86℃ for 1 hour. Then, cool the reactor to about 65℃. Weigh 0.06 g of tert-butyl hydrogen peroxide (70%), dilute it with 0.1 g of water, and slowly add it to the reactor over about 15 minutes. At the same time, weigh 0.06 g of sodium formaldehyde sulfoxylate and dilute it with 0.1 g of pure water. Add this solution to the reactor over 15 minutes immediately after the tert-butyl hydrogen peroxide solution has been added. After the sodium formaldehyde sulfoxylate solution has been added, maintain the temperature for half an hour. Then, cool the reactor to about 40℃ and add 1.2 g of AMPS organic amine, 0.2 g of mineral oil defoamer (BASF Foamaster MO 2190), 0.1 g of preservative (20% BIT), and 3.3 g of water. After stirring, test the pH to be 7.7 and the viscosity to be 10000 cps. Filter the mixture and discharge. Take 75g of the cooled acrylic emulsion and put it into a high-speed disperser. Start stirring at 1500rpm. Then, mix 104.5g of SZ401 silicone resin, SJ201 crosslinking agent, and SC51 catalyst from Guangzhou Chemical Co., Ltd., Chinese Academy of Sciences, in a ratio of 100 / 3 / 1.5. Slowly add the mixture to the neutralized acrylic emulsion over 25 minutes. At the same time, take 30g of water and slowly add it dropwise to the high-speed dispersion vessel while adding the silicone resin. Maintain the viscosity of the emulsion in the vessel within the range of 5000-1000000cps. After adding the water, continue to increase the high-speed dispersion to 2000rpm for 15 minutes. Then, add 80g of water to dilute to a viscosity of about 300cps. Reduce the stirring speed and slowly heat the reaction vessel to about 70℃. Maintain the temperature for 2.5 hours before cooling and discharging.When this emulsion is coated and made into textile tape, its surface can be written on with ballpoint pens or ink pens without shrinkage, the release force is about 2N / 25mm, it has a comfortable skin feel, and the water vapor permeability is ≥ 600 g / m²·24h. Example

[0042] Take 0.2 g of sodium isomeric alcohol polyoxyethylene ether sulfate (70% content) and about 0.05 g of isomeric alcohol polyoxyethylene ether (10EO). First, dilute and dissolve them with 2 g of pure water, then add them to the pre-emulsification tank and start stirring. While stirring, slowly add 15 g of isooctyl acrylate, 5 g of styrene, 30 g of methyl methacrylate, 1 g of methacrylic acid, 0.5 g of itaconic acid, 1.5 g of polyethylene glycol monoacrylate (200 molecular weight specification), 1 g of methacryloyloxypropyl diethoxysilane, and 0.5 g of diacetone acrylamide to the pre-emulsification tank and stir rapidly for more than half an hour to pre-emulsify the acrylate monomers into a milky white pre-emulsion for later use. Then, add 36g of pure water and 0.1g of sodium phosphate buffer to the reactor, and start stirring. Heat to approximately 70°C, then add 0.08g of ammonium persulfate initiator and 0.05g of sodium metabisulfite, along with 3% of the pre-emulsion mentioned above to the bottom of the reactor. After 15 minutes, begin uniformly adding the remaining pre-emulsion to the reactor over 3.5 hours. Next, weigh out 0.1g of ammonium persulfate and dissolve it in 2g of water, and dilute 0.1g of sodium metabisulfite with 2g of water. Simultaneously, while the pre-emulsion is being added, slowly and uniformly add the ammonium persulfate solution and the reducing agent sodium metabisulfite to the reactor over 4 hours. Maintain a constant reaction temperature of 70-74°C. After the addition is complete, maintain the temperature at 70-76℃ for 1 hour. Then, cool the reactor to about 60℃. Weigh 0.05 g of tert-butyl hydrogen peroxide (70%), dilute it with 0.1 g of water, and slowly add it to the reactor over about 15 minutes. At the same time, weigh 0.05 g of sodium formaldehyde sulfoxylate and dilute it with 0.1 g of pure water. Add this solution to the reactor over 15 minutes immediately after the tert-butyl hydrogen peroxide solution has been added. After the sodium formaldehyde sulfoxylate solution has been added, maintain the temperature for half an hour. Then, cool the reactor to about 40℃ and add 1.2 g of 25% sodium hydroxide solution, 0.2 g of mineral oil defoamer (BASF Foamaster MO 2190), 0.2 g of preservative (2.5% Kathon solution), about 0.4 g of adipamide (ADH), and 0.52 g of water. After stirring, test the pH to be 7.3 and the viscosity to be 12000 cps. Filter the solution and discharge.Take 50g of the cooled acrylic emulsion and put it into a high-speed disperser. Start stirring at 1500rpm. Then, mix 104g of SZ296 silicone resin, SJ29 crosslinking agent, and SC51 catalyst in a ratio of 100 / 3 / 1 from Guangzhou Chemical Co., Ltd., Chinese Academy of Sciences. Slowly add the mixture to the neutralized acrylic emulsion over 30 minutes. At the same time, take 25g of water and slowly add it dropwise to the high-speed dispersion vessel while adding the silicone resin. Maintain the viscosity of the emulsion in the vessel within the range of 5000-1000000cps. After adding the water, continue to increase the high-speed dispersion to 2000rpm for 10 minutes. Then, add 100g of water to dilute to a viscosity of about 100cps. Reduce the stirring speed and slowly heat the reaction vessel to about 50℃. Maintain the temperature for 4 hours before cooling and discharging. When this emulsion is coated and made into textile tape, its surface can be written on with ballpoint pens or ink pens without shrinkage, the release force is about 1N / 25mm, it has a comfortable skin feel, and the water vapor permeability is ≥ 500 g / m²·24h. Example

[0043] Take 0.6 g of sodium allyl isoalkyl alkyl sulfate (23% content) as the emulsifier, dilute and dissolve it with 2 g of pure water, and then add it to the pre-emulsification vessel. Start stirring, and slowly add 10 g of isooctyl acrylate, 5 g of butyl acrylate, 10 g of ethyl acrylate, 25 g of methyl methacrylate, 1 g of methacrylic acid, 1 g of β-carboxyethyl acrylate, 2 g of polyethylene glycol monoacrylate (600 molecular weight specification), 1 g of methacryloxypropyltriethoxysilane, and 1.2 g of 48% N-hydroxymethylacrylamide to the pre-emulsification vessel while stirring rapidly. Emulsify for more than half an hour to pre-emulsify the acrylate monomers into a milky white pre-emulsion and set it aside. Then add 35 g of pure water and 0.1 g of sodium bicarbonate buffer to the reaction vessel, start stirring, and heat to about 80°C. Then add 0.08 g of ammonium persulfate initiator to the reaction vessel, and simultaneously add 5% of the above pre-emulsion to the bottom of the vessel. After 15 minutes, the remaining pre-emulsion was added dropwise to the reactor at a uniform rate over 3.5 hours. Then, 0.1 g of ammonium persulfate was weighed and dissolved in 2 g of water. Simultaneously with the addition of the pre-emulsion, the ammonium persulfate solution was slowly and uniformly added dropwise to the reactor over 3.7 hours. The reaction temperature in the reactor was kept constant at 80-84℃. After the addition is complete, maintain the temperature at 80-86℃ for 1 hour. Then, cool the reactor to about 65℃. Weigh 0.06 g of tert-butyl hydrogen peroxide (70%), dilute it with 0.1 g of water, and slowly add it to the reactor over about 15 minutes. At the same time, weigh 0.06 g of sodium formaldehyde sulfoxylate and dilute it with 0.1 g of pure water. Add this solution to the reactor over 15 minutes immediately after the tert-butyl hydrogen peroxide solution has been added. After the sodium formaldehyde sulfoxylate solution has been added, maintain the temperature for half an hour. Then, cool the reactor to about 40℃ and add 1.2 g of ammonia, 0.2 g of mineral oil defoamer (BASF Foamaster MO 2190), 0.1 g of preservative (30% bromonitrophenol), and 3.3 g of water. After stirring, test the pH to be 8.0 and the viscosity to be 13000 cps. Filter the mixture and discharge. Take another 200g of the cooled acrylic emulsion into a high-speed disperser and start stirring at 1500rpm. Then, mix 104.5g of SZ401 silicone resin, SJ201 crosslinking agent, and SC51 catalyst from Guangzhou Chemical Co., Ltd., Chinese Academy of Sciences, in a ratio of 100 / 3 / 1.5. Slowly add the mixture to the neutralized acrylic emulsion over 25 minutes. At the same time, add 10g of water dropwise to the high-speed dispersion vessel while adding the silicone resin, maintaining the viscosity of the emulsion in the vessel within the range of 5000-1000000cps. After adding the water, continue to increase the high-speed dispersion to 2000rpm for 15 minutes. Then, add 100g of water to dilute to a viscosity of about 200cps, reduce the stirring speed, and slowly heat the reaction vessel to about 60℃ and maintain the temperature for 2 hours before cooling and discharging.When this emulsion is coated and made into textile tape, its surface can be written on with ballpoint pens or ink pens without shrinkage, the release force is about 5N / 25mm, it has a comfortable skin feel, and the water vapor permeability is ≥ 500 g / m²·24h.

[0044] Take 0.6 g of sodium isoalkylol sulfate (23% content) emulsifier into a high-speed disperser. Then, mix 104.5 g of SZ401 silicone resin, SJ201 crosslinking agent, and SC51 catalyst (from Guangzhou Chemical Co., Ltd., Chinese Academy of Sciences) in a ratio of 100 / 3 / 1.5. After mixing, add the emulsifier and continue stirring for 5 minutes until homogeneous. Then, slowly add 120 g of water to the high-speed dispersed silicone resin over 2 hours to prepare a milky white, homogeneous emulsion. Because this emulsion lacks the coating of acrylic resin, it will gel after being left at room temperature for 8 hours or during stirring and heating to 60°C. If this dispersed silicone resin emulsion is coated into a film within one hour, the surface will be unwriteable with a ballpoint pen and will show severe shrinkage. If approximately 225 g of this pre-dispersed silicone resin emulsion is mixed with 100 g of conventional polyacrylic acid emulsion (BASF's Arconall V206AP), the emulsion will also gel and fail after being left at room temperature for 8 hours or heated to 60-80°C. If coated onto a textile tape before gelation, the surface will shrink when written on with a ballpoint pen or ink pen because free silicone resin will migrate to the coating surface. Release force is approximately 3N / 25mm, with a comfortable, skin-like feel, and water vapor permeability ≥500 g / m²·24h.

[0045] Comparative Example 2 Take 0.6 g of sodium allyl isoalkyl alkyl sulfate (23% content) as the emulsifier, dilute and dissolve it with 2 g of pure water, and then add it to the pre-emulsification vessel. Start stirring, and slowly add 5 g of isooctyl acrylate, 5 g of butyl acrylate, 10 g of ethyl acrylate, 30 g of methyl methacrylate, 1 g of methacrylic acid, 1 g of β-carboxyethyl acrylic acid, 2 g of polyethylene glycol monoacrylate (600 molecular weight specification), 1 g of methacryloxypropyltriethoxysilane, and 1.2 g of 48% N-hydroxymethylacrylamide to the pre-emulsification vessel. Emulsify rapidly for more than half an hour to pre-emulsify the acrylate monomers into a milky white pre-emulsion and set it aside. Then add 35 g of pure water and 0.1 g of sodium bicarbonate buffer to the reaction vessel, start stirring, and heat to about 80°C. Then add 0.08 g of ammonium persulfate initiator to the reaction vessel, and simultaneously add 5% of the above pre-emulsion to the bottom of the vessel. After 15 minutes, the remaining pre-emulsion was added dropwise to the reactor at a uniform rate over 3.5 hours. Then, 0.1 g of ammonium persulfate was weighed and dissolved in 2 g of water. Simultaneously with the addition of the pre-emulsion, the ammonium persulfate solution was slowly and uniformly added dropwise to the reactor over 3.7 hours. The reaction temperature in the reactor was kept constant at 80-84℃. After the addition is complete, maintain the temperature at 80-86℃ for 1 hour. Then, cool the reactor to about 65℃. Weigh 0.06 g of tert-butyl hydrogen peroxide (70%), dilute it with 0.1 g of water, and slowly add it to the reactor over about 15 minutes. At the same time, weigh 0.06 g of sodium formaldehyde sulfoxylate and dilute it with 0.1 g of pure water. Add this solution to the reactor over 15 minutes immediately after the tert-butyl hydrogen peroxide solution has been added. After the sodium formaldehyde sulfoxylate solution has been added, maintain the temperature for half an hour. Then, cool the reactor to about 40℃ and add 1.2 g of ammonia, 0.2 g of mineral oil defoamer (BASF Foamaster MO 2190), 0.1 g of preservative (30% bromonitrophenol), and 3.3 g of water. After stirring, test the pH to be 8.0 and the viscosity to be 13000 cps. Filter the mixture and discharge. When the cooled acrylic emulsion is directly coated to make textile tape, because it does not contain any silicone, the release force is greater than 15N / 25mm, and there is basically no release effect, making the tape difficult to tear and unwinding failure.

[0046] This invention has been described by way of embodiments, but does not constitute a limitation thereof. Other variations of the disclosed embodiments, which are readily apparent to those skilled in the art, should fall within the scope of the claims of this invention, with reference to the description of this invention.

Claims

1. A versatile and breathable water-based coating for medical tape, characterized in that: Includes acrylate monomers, emulsifiers, initiators, and silicone resins; The emulsifier is anionic or a combination of anionic and nonionic emulsifiers, wherein the amount used, calculated by solids content, is: 0.1-1% for anionic emulsifier and no more than 0.5% for nonionic emulsifier; The initiator is a water-soluble oxidant, or a combination of a water-soluble oxidant and a reducing agent, wherein the amount used, calculated by solids, is: 0.05-0.8% water-soluble oxidant and 0.01-0.5% reducing agent; The balance of the acrylic monomer, emulsifier, and initiator is the amount of silicone resin used; The acrylic monomers include soft monomers, hard monomers, and functional monomers for improving air permeability. The soft monomers include butyl acrylate, ethyl acrylate, or isooctyl acrylate. The hard monomers include methyl acrylate, methyl methacrylate, vinyl acetate, or styrene. The functional monomers include acidic monomers, hydrophilic acrylate monomers, organosilicon crosslinking monomers, or crosslinking monomers. The dosage based on solids is: soft monomers 30-65%, hard monomers 30-65%, and functional monomers 1-5%.

2. The versatile and breathable water-based coating for medical tape according to claim 1, characterized in that: The silicone resin is a two-component or three-component silicone resin that can react at room temperature.

3. The versatile and breathable water-based coating for medical tape according to claim 1 or 2, characterized in that: The silicone resin includes condensation silicone resin and addition silicone resin.

4. The versatile and breathable water-based coating for medical tape according to claim 1, characterized in that: The emulsifier includes one or more of dodecylbenzene sulfonate, dodecyl / hexadecyl ether sulfate, allyl alkyl alcohol sulfate, fatty alcohol polyoxyethylene ether sulfate / phosphate, fatty alcohol polyoxyethylene ether sulfosuccinate, or fatty alcohol polyoxyethylene ether.

5. The versatile and breathable water-based coating for medical tape according to claim 1, characterized in that: The acidic monomer is one or more of the following: acrylic acid, methacrylic acid, 2-acrylamido-2-methylpropanesulfonic acid, itaconic acid, β-carboxyethylacrylic acid, fumarate monoester, maleic acid and its monoester derivatives, or sodium vinyl sulfonate.

6. The versatile and breathable water-based coating for medical tape according to claim 1, characterized in that: The hydrophilic monomer is generally one or more of hydroxyethyl acrylate, hydroxyethyl methacrylate, polyethylene glycol acrylate, or methoxy polyethylene glycol acrylate; its amount, calculated by solids, is 2-5%.

7. The versatile and breathable water-based coating for medical tape according to claim 1, characterized in that: The organosilicon crosslinking monomer is one or more of vinyltrimethoxysilane and its derivatives, methacryloyloxypropyltrimethoxysilane and its derivatives, diacetone acrylamide, AAEM-ADH, diallyl phthalate, diallyl maleate, dipropylene glycol diacrylate, or hydroxymethylacrylamide.

8. The versatile and breathable water-based coating for medical tape according to claim 1, characterized in that: The water-soluble oxidant is one or more of sodium persulfate, ammonium persulfate, or potassium persulfate; the reducing agent is one or more of sodium sulfite, sodium formaldehyde sulfoxylate, vitamin C, or ferrous sulfate.

9. The versatile and breathable water-based coating for medical tape according to claim 1, characterized in that: The versatile and breathable water-based coating of the medical tape also includes tert-butyl hydroperoxide as an oxidizing agent for removing residues and reducing odor, or sodium formaldehyde sulfoxylate or vitamin C as a reducing agent. The versatile and breathable water-based coating of the medical tape also includes an alkali for neutralization, including: ammonia, organic amine sodium hydroxide or potassium hydroxide, wherein the organic amine is one or more of AMP95, dimethylethanolamine, diethanolamine, triethanolamine, polyetheramine, polyethylene polyamine, or amino acids containing an amino group.

10. A method for preparing a water-based coating for a widely applicable and breathable medical tape according to claims 1-9, characterized in that: The acrylic monomer, emulsifier, and initiator using only a water-soluble oxidant are reacted by adding the monomer pre-emulsion and initiator dropwise at a temperature of 78-88°C; or the initiator is used in combination with both a reducing agent and an oxidizing agent, and the dropwise reaction temperature is reduced to 65-78°C. Take the above-synthesized acrylic emulsion and add it into a high-speed dispersion device. Under high-speed stirring, slowly add organosilicon resin over a period of 10 to 60 minutes. Control the temperature at 20-40°C. While adding the resin, slowly add water according to the viscosity to control the viscosity to be no lower than 5000 cps and no higher than 1,000,000 cps. After the silicone resin is added, continue to disperse at a high speed of 1500 rpm or higher for 10-30 minutes, then reduce the stirring speed to below 1000 rpm, add water to dilute to a viscosity of 100-1000 cps, and after 1-2 hours, raise the temperature to 60-80℃ and maintain a low stirring speed of 400-800 rpm for 3 hours to complete the reaction. Cool down and discharge the material. The silicone resin that has not been completely reacted can be reacted at room temperature after cooling.