Medical organic silicon pressure-sensitive adhesive with antibacterial property and preparation method of medical organic silicon pressure-sensitive adhesive

Abstract

The invention relates to a medical organic silicon pressure-sensitive adhesive with antibacterial performance and a preparation method thereof, and the preparation method comprises the following steps: firstly mixing 2-5 parts of a surfactant and 0.5-1.5 parts of an antibacterial group, and then uniformly stirring at 2000-2500rpm; and adding a mixture of 10-20 parts of methyl vinyl silicone rubber, 0.5-2 parts of hydrogen-containing silicone oil, 40-50 parts of a solvent, 5-20 parts of vinyl MQ silicon resin, 20-35 parts of methyl MQ silicon resin, 0.04-0.4 part of a platinum catalyst and 0.03-0.3 part of an inhibitor into the reactor, and stirring for 4-6 hours to prepare the medical organic silicon pressure-sensitive adhesive with the antibacterial property. The medical organic silicon pressure-sensitive adhesive with the antibacterial property, prepared by the method, has good antibacterial property and cohesiveness, and is simple in process, high in production efficiency, low in cost and convenient to popularize and apply.

Description

Technical Field

[0001] This invention relates to the field of silicone rubber technology, and in particular to a medical silicone pressure-sensitive adhesive with antibacterial properties and its preparation method. Background Technology

[0002] In daily life, silicone pressure-sensitive adhesives are commonly used in products that come into direct contact with human skin due to their excellent adhesion, resistance to high and low temperatures, chemical inertness, and biocompatibility. Examples include massage patches and diapers. Massage patches require adhesives to adhere to the areas of the body that need massage. However, some adhesives on the market, and massage patches applied with them, often generate harmful microorganisms due to their close contact with the skin and prolonged use. When using massage patches, the skin directly contacts the medications carried on the patches through the adhesive, which can harm human health. Furthermore, conventional adhesives suffer from insufficient cohesive strength, poor durability, and poor sweat resistance. Therefore, developing a novel silicone pressure-sensitive adhesive to address the problems of harmful microorganism generation in existing technologies, while also possessing good shear strength, weather resistance, and adhesion, has become a key research focus and challenge. In addition, to meet the requirements of the pharmaceutical industry for silicone pressure-sensitive adhesives, such as safety, environmental friendliness, ease of application, and adhesion to common substrates, developing a new type of medical silicone pressure-sensitive adhesive has significant research and application value.

[0003] Quaternary ammonium salts can adsorb negatively charged bacteria, exhibiting excellent bactericidal effects and are widely used internationally. However, ordinary quaternary ammonium salts have low chemical activity, exist primarily in a free state during application, and are relatively toxic and irritating. When used as antibacterial agents on textiles, they are easily dissolved and washed away, and tend to accumulate gradually on the human body surface, posing health risks with long-term use. By incorporating the quaternary ammonium salt structure into organosilicon polymers to prepare organosilicon quaternary ammonium salts, polymer-structured organosilicon quaternary ammonium salts can be created. If the density of the quaternary ammonium salt structure within the organosilicon polymer is appropriate, its properties can undergo a significant transformation, resulting in superior antibacterial performance.

[0004] Several invention patents have been granted regarding solutions to the problem of antibacterial medical silicone pressure-sensitive adhesives. For example: CN 114316853 A discloses an antibacterial acrylic pressure-sensitive adhesive and its preparation method. The antibacterial acrylic pressure-sensitive adhesive of this invention is prepared by copolymerizing methacryloyloxyethyl hexadecyl dimethyl ammonium bromide with soft acrylic monomers, hard acrylic monomers, and hydroxyacrylic monomers under the action of an initiator, thus obtaining an MHDB-modified antibacterial acrylic pressure-sensitive adhesive. It not only possesses good antibacterial properties but also excellent adhesion; however, it is not a silicone pressure-sensitive adhesive.

[0005] Patents with publication numbers CN 101560220A, CN 107445983A, and CN 107372579A have optimized and synthesized several organosilicon quaternary ammonium salts with twin structures, but they still retain the methoxy or ethoxy structure on the silicon atom. Therefore, these organosilicon quaternary ammonium salts still have the problem of easy hydrolysis. Summary of the Invention

[0006] Therefore, in order to solve the above problems, the present invention provides a medical silicone pressure-sensitive adhesive with antibacterial properties.

[0007] Compared with the prior art, the core innovation of this invention lies in the introduction of organosilicon quaternary ammonium salt and a specific surfactant, which enables the antibacterial agent to exist stably in the organosilicon pressure-sensitive adhesive system, thereby achieving long-lasting and efficient antibacterial performance.

[0008] Organosilicon quaternary ammonium salts are compounds that possess both an organosilicon framework and quaternary ammonium salt groups. The organosilicon framework imparts good heat resistance, weather resistance, and flexibility, while the quaternary ammonium salt groups exhibit excellent antibacterial properties. By introducing organosilicon quaternary ammonium salts into organosilicon pressure-sensitive adhesive systems, the good compatibility between the organosilicon framework and the matrix resin can be utilized to ensure the uniform dispersion of the antibacterial agent in the colloid, thereby improving the antibacterial effect and the transparency of the pressure-sensitive adhesive.

[0009] The addition of surfactants further improves the dispersibility and stability of organosilicon quaternary ammonium salts in organosilicon pressure-sensitive adhesive systems. The selected surfactants not only improve the interfacial compatibility between the organosilicon quaternary ammonium salt and the matrix resin, but also form a protective layer, reducing the degradation or migration of the organosilicon quaternary ammonium salt during synthesis or use, thereby enhancing the durability of antibacterial properties.

[0010] The purpose of this invention is to overcome the shortcomings of the prior art and provide a medical silicone pressure-sensitive adhesive with antibacterial properties, which has the following technical features: By weight, it includes the following components: 10-20 parts of methyl vinyl silicone rubber, 0.5-2 parts of hydrogen-containing silicone oil, 40-50 parts of solvent, 5-20 parts of vinyl MQ silicone resin, 20-35 parts of methyl MQ silicone resin, 0.03-0.3 parts of inhibitor, 0.04-0.4 parts of catalyst, 2-5 parts of surfactant, and 0.5-1.5 parts of antibacterial group.

[0011] The hydrogen-containing silicone oil is an end-group or side-chain type hydrogen-containing silicone oil with a viscosity of 100-1000 mPa·s and a hydrogen content of 0.15-1.0%.

[0012] The solvent is one or more of toluene, xylene, ethyl acetate, No. 120 solvent gasoline, and acetone.

[0013] The vinyl MQ silicone resin has an M / Q value of 0.6-0.9, a relative molecular mass of 2500-4500 g / mol, and a vinyl content of 1%-5%.

[0014] The methyl MQ silicone resin has an M / Q value of 0.6-0.9 and a relative molecular mass of 3500-6000 g / mol.

[0015] The inhibitor is selected from one or more of ethynylcyclohexanol, diallyl maleate, 2-methyl-3-butyn-2-ol, tetramethyldivinyldisiloxane, tetramethyltetravinylcyclotetrasiloxane, and 3-methyl-1-dodecyn-3-ol, and the amount of inhibitor added is 0.03-0.3 parts.

[0016] The Si-H addition catalyst is a platinum catalyst with a platinum content of 0.25-0.6%.

[0017] The surfactant is selected from octadecylamine polyoxyethylene ether AC-1815 and / or AC-1820.

[0018] The antibacterial group is one or more of the following: octadecyl dimethylamine methacrylate, heptadecanyl dimethylamine methacrylate, hexadecyl dimethylamine methacrylate, pentadecyl dimethylamine methacrylate, tetradecyl dimethylamine methacrylate, tridecyl dimethylamine methacrylate, dodecyl dimethylamine methacrylate, undecyl dimethylamine methacrylate, decadecyl dimethylamine methacrylate, nonadecyl dimethylamine methacrylate, octadecyl dimethylamine methacrylate, heptadecyl dimethylamine methacrylate, hexadecyl dimethylamine methacrylate, pentadecyl dimethylamine methacrylate, tetradecyl dimethylamine methacrylate, and tridecyl dimethylamine methacrylate.

[0019] The antibacterial group is first mixed with a surfactant and stirred evenly at 2000-2500 rpm, and then mixed with other raw materials to prepare the product. The surfactant in this application ensures sufficient contact between the antibacterial agent and the silicone resin material, achieving a stable antibacterial effect.

[0020] Octadecylamine polyoxyethylene ether and organosilicon quaternary ammonium salt can be physically dispersed in the matrix of organosilicon PSA, interacting with the matrix through physical interactions such as van der Waals forces and hydrogen bonds. The organosilicon quaternary ammonium salt can react with active groups such as hydroxyl and epoxy groups in the organosilicon PSA to form covalent bonds, achieving chemical crosslinking. Active groups (such as hydroxyl and amino groups) in octadecylamine polyoxyethylene ether can react with crosslinking agents in the organosilicon PSA, participating in the formation of the crosslinking network. The cations in the organosilicon quaternary ammonium salt can form ionic bonds with anionic groups (if present) in octadecylamine polyoxyethylene ether, or with anionic groups in the organosilicon PSA, further improving compatibility and stability.

[0021] Octadecylamine polyoxyethylene ether and organosilicon quaternary ammonium salt can produce synergistic effects in organosilicon pressure-sensitive adhesives through physical mixing and chemical bonding, thereby improving the adhesion, cohesive destructive properties, antistatic properties and antibacterial properties of PSA.

[0022] The preparation method of octadecyl dimethylamine methacrylate is as follows: The quaternary ammonium salt is synthesized via the Menschutkin process, which involves the addition reaction of a tertiary amine with an organohalide. 2-(dimethylamino)ethyl methacrylate is a methacrylate containing a tertiary amine, and 1-bromohexadecane is an organohalide. Octadecyl dimethylamine methacrylate with a chain length of 18 is synthesized. 10 mmol of 2-(dimethylamino)ethyl methacrylate, 10 mmol of 1-bromohexadecane, and 3 g of anhydrous ethanol are placed in a brown wide-mouth glass reagent bottle. A clean, straight-tube magnetic rotor is gently placed into the bottle, and the cap is gently screwed onto the bottle opening and tightened. Plastic wrap is used to seal the bottle opening to ensure a tight seal. The reagent bottle is placed in a thermostatic magnetic stirrer and stirred at 70°C and 800 rpm for 24 hours. After the reaction is complete, the liquid is poured into a clean porcelain evaporating dish, which is then placed in a thermostatic water bath, taking care not to splash water into the evaporating dish. The anhydrous ethanol is evaporated by constantly stirring with a glass rod. The entire evaporation process is carried out in a well-ventilated place without open flame, and finally a colorless, transparent, viscous liquid is obtained. It should be stored away from light.

[0023] For other alkyl dimethyl methacrylate synthesis methods with chain lengths of 3-17, simply change the organic halide to the corresponding chain length while keeping other conditions unchanged.

[0024] A method for preparing a medical-grade silicone pressure-sensitive adhesive with antibacterial properties includes the following steps: First, mix 2-5 parts of surfactant and 0.5-1.5 parts of antibacterial group, and stir evenly at 2000-2500 rpm. Then, add a mixture of 10-20 parts of methyl vinyl silicone rubber, 0.5-2 parts of hydrogen-containing silicone oil, 40-50 parts of solvent, 5-20 parts of vinyl MQ silicone resin, 20-35 parts of methyl MQ silicone resin, and 0.03-0.3 parts of inhibitor into the reactor. Turn on the electric stirrer and stir slowly to mix the materials evenly until completely mixed to obtain the addition-type organosilicon pressure-sensitive adhesive main agent. Then, add 0.04-0.4 parts of catalyst and stir thoroughly. Use a film preparation device to evenly coat the adhesive onto a 50μm PET film. Then bake at 130-140℃ for 1-3 minutes, remove, attach to a 50μm PET film, and peel off the PET substrate protective film to test the peel strength performance.

[0025] The aforementioned antibacterial medical silicone pressure-sensitive adhesive is colorless and transparent in appearance, with a viscosity of 1000~50000 cP. Detailed Implementation

[0026] The present invention will be further explained below with reference to the embodiments, but the embodiments do not limit the present invention in any way.

[0027] Example 1 0.65g of octadecyl dimethylamine methacrylate was first mixed with 1.5g of octadecylamine polyoxyethylene ether AC-1815 surfactant, and then stirred at 2500rpm to obtain a mixed formulation. 22g of vinyl-terminated methyl vinyl silicone rubber, 35g of methyl MQ silicone resin, 15g of vinyl MQ silicone resin, 0.75g of hydrogen-containing silicone oil, 0.04g of ethynylcyclohexanol, and 56g of ethyl acetate were added to a reactor. The electric stirrer was turned on, and the mixture was slowly stirred until it was completely homogeneous, yielding the addition-type silicone pressure-sensitive adhesive main agent. Then, 0.06g of platinum catalyst was added, and the mixture was stirred thoroughly. A film preparation device was used to evenly coat the adhesive onto a 50μm PET film, which was then baked at 140℃ for 3 minutes. The coating was then removed, attached to a 50μm PET film, and the peel strength was tested by peeling off the protective film from the PET substrate.

[0028] Example 2 0.65g of heptadecanyl dimethyl methacrylate was first mixed with 1.5g of octadecylamine polyoxyethylene ether AC-1820 surfactant, and then stirred at 2500rpm to obtain a mixed formulation. Then, 22g of vinyl-terminated methyl vinyl silicone rubber, 35g of methyl MQ silicone resin, 15g of vinyl MQ silicone resin, 0.75g of hydrogen-containing silicone oil, 0.04g of ethynylcyclohexanol, and 56g of ethyl acetate were added to the reactor. The electric stirrer was turned on, and the mixture was slowly stirred until it was completely mixed to obtain the addition-type silicone pressure-sensitive adhesive main agent. Then, 0.06g of platinum catalyst was added, and after thorough mixing, the adhesive was evenly coated onto a 50μm PET film using a coating tool. The film was then baked at 140℃ for 3 minutes, removed, and attached to a 50μm PET film. The peel strength performance was tested by peeling off the PET substrate protective film.

[0029] Example 3 0.65g of hexadecyl dimethyl methacrylate was first mixed with 1.5g of octadecylamine polyoxyethylene ether AC-1820 surfactant, and then stirred at 2500rpm to obtain a mixed formulation. Then, 22g of vinyl-terminated methyl vinyl silicone rubber, 35g of methyl MQ silicone resin, 15g of vinyl MQ silicone resin, 0.75g of hydrogen-containing silicone oil, 0.04g of ethynylcyclohexanol, and 56g of ethyl acetate were added to the reactor. The electric stirrer was turned on, and the mixture was slowly stirred until it was completely mixed to obtain the addition-type silicone pressure-sensitive adhesive main agent. Then, 0.06g of platinum catalyst was added, and after thorough mixing, the adhesive was evenly coated onto a 50μm PET film using a coating tool. The film was then baked at 140℃ for 3 minutes, removed, and attached to a 50μm PET film. The peel strength performance was tested by peeling off the PET substrate protective film.

[0030] Examples 4-16 are identical to Example 2 except that the antibacterial groups are replaced with pentadecyl dimethylamine methacrylate, tetradecyl dimethylamine methacrylate, tridecyl dimethylamine methacrylate, dodecyl dimethylamine methacrylate, undecyl dimethylamine methacrylate, decadecyl dimethylamine methacrylate, nonadecyl dimethylamine methacrylate, octadecyl dimethylamine methacrylate, heptadecyl dimethylamine methacrylate, hexadecyl dimethylamine methacrylate, pentadecyl dimethylamine methacrylate, tetradecyl dimethylamine methacrylate, and tridecyl dimethylamine methacrylate.

[0031] Comparative Example 1 22g of vinyl-terminated methyl vinyl silicone rubber, 35g of methyl MQ silicone resin, 15g of vinyl MQ silicone resin, 0.75g of hydrogen-containing silicone oil, 0.04g of ethynylcyclohexanol, 56g of ethyl acetate, and 0.65g of hexadecyl dimethylamine methacrylate were added to a reactor. The electric stirrer was turned on and the mixture was slowly stirred until it was completely mixed to obtain the addition-type silicone pressure-sensitive adhesive main agent. Then, 0.06g of platinum catalyst was added and stirred thoroughly. The adhesive was then evenly coated onto a 50μm PET film using a coating tool. The film was then baked at 140℃ for 3 minutes, removed, and attached to a 50μm PET film. The peel strength performance was tested by peeling off the protective film of the PET substrate.

[0032] Comparative Example 2 22g of vinyl-terminated methyl vinyl silicone rubber, 35g of methyl MQ silicone resin, 15g of vinyl MQ silicone resin, 0.75g of hydrogen-containing silicone oil, 0.04g of ethynylcyclohexanol, 56g of ethyl acetate, and 0.65g of decaalkyldimethylamine methacrylate were added to a reactor. The electric stirrer was turned on and the mixture was slowly stirred until it was completely mixed to obtain the addition-type silicone pressure-sensitive adhesive main agent. Then, 0.06g of platinum catalyst was added and stirred thoroughly. The adhesive was then evenly coated onto a 50μm PET film using a coating tool. The film was then baked at 140℃ for 3 minutes, removed, and attached to a 50μm PET film. The peel strength performance was tested by peeling off the protective film of the PET substrate.

[0033] Comparative Example 3 22g of vinyl-terminated methyl vinyl silicone rubber, 35g of methyl MQ silicone resin, 15g of vinyl MQ silicone resin, 0.75g of hydrogen-containing silicone oil, 0.04g of ethynylcyclohexanol, 56g of ethyl acetate, and 0.65g of pentaalkyldimethylamine methacrylate were added to a reactor. The electric stirrer was turned on and the mixture was slowly stirred until it was completely mixed to obtain the addition-type silicone pressure-sensitive adhesive main agent. Then, 0.06g of platinum catalyst was added and stirred thoroughly. The adhesive was then evenly coated onto a 50μm PET film using a film preparation tool. The film was then baked at 140℃ for 3 minutes, removed, and attached to a 50μm PET film. The peel strength performance was tested by peeling off the protective film of the PET substrate.

[0034] The test items and conditions are as follows: 1. Antibacterial performance test: conducted according to GB / T 21510-2008.

[0035] 2. Mechanical property testing: The pressure-sensitive adhesives of Examples 1-16 and Comparative Example 1 were coated onto 50μm PET films using a four-sided coater, with the dry adhesive thickness controlled at 25μm. Release films were then applied to protect the adhesive surfaces. The films were cured in a 140℃ oven for 3 minutes. They were then cut into 25mm wide tapes, and their 180° peel force, initial tack (rolling ball method), and holding time (with a 1kg weight) were tested. The results are as follows: The performance parameters of the prepared antibacterial medical silicone pressure-sensitive adhesive are shown in Table 1 below.

[0036] Table 1

[0037] The antibacterial pressure-sensitive adhesives prepared in Examples 1-16 above were subjected to initial tack test (conducted according to the method disclosed in GB / T 4852-CN 119614108 A2002 "Test Method for Initial Tack of Pressure-Sensitive Adhesive Tape"), holding power test (conducted according to the method disclosed in GB / T 4851-2014 "Test Method for Holding Power of Adhesive Tape"), and peel strength test (conducted according to the method disclosed in GB / T 2792-2014 "Test Method for Peel Strength of Adhesive Tape").

[0038] The test results from Examples 1-16 and Comparative Examples 1-3 show that the present invention, by adding organosilicon quaternary ammonium salt compounds and surfactants with different chain lengths to the addition-type organosilicon pressure-sensitive adhesive, can participate in the cross-linking of the reaction system to achieve a long-lasting and stable antibacterial effect. Furthermore, it improves the corresponding mechanical properties of the composite resin. Specifically, the antibacterial effect is better for organosilicon quaternary ammonium salts with chain lengths of C8-C14 than C15-C18, and C15-C18 is better than C3-C7. The absence of octadecylamine polyoxyethylene ether would affect the antibacterial stability of the organosilicon quaternary ammonium salts in the system.

[0039] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements can be made without departing from the principle of the present invention, and these improvements should also be considered within the scope of protection of the present invention.

Claims

1. A medical silicone pressure-sensitive adhesive having antibacterial properties, characterized in that, The organic silicone pressure-sensitive adhesive comprises 10-20 parts of methyl vinyl silicone rubber, 0.5-2 parts of hydrogen-containing silicone oil, 40-50 parts of solvent, 5-20 parts of vinyl MQ silicone resin, 20-35 parts of methyl MQ silicone resin, 0.03-0.3 parts of inhibitor, 0.04-0.4 parts of platinum catalyst, 2-5 parts of surfactant and 0.5-1.5 parts of antibacterial group.

2. The medical organic silicone pressure-sensitive adhesive having an antibacterial property according to claim 1, characterized by: The methyl vinyl silicone rubber has a vinyl mass percentage of 0.04-5.0% and a molecular weight of 450000-950000.

3. The medical organic silicone pressure-sensitive adhesive having an antibacterial property according to claim 1, characterized by: The hydrogen-containing silicone oil is one or more of side hydrogen-containing silicone oil, end hydrogen-containing silicone oil and end-side hydrogen-containing silicone oil, and has a hydrogen mass percentage of 0.05-1%.

4. The medical silicone pressure-sensitive adhesive having an antibacterial property according to claim 1, characterized by: The solvent is one or more of toluene, xylene, ethyl acetate, 120# solvent gasoline and acetone.

5. The medical organic silicone pressure-sensitive adhesive having an antibacterial property according to claim 1, characterized by: The vinyl MQ silicone resin has an M / Q value of 0.6-0.9, a relative molecular mass of 2500-4500 g / mol and a vinyl content of 1-5%, and the methyl MQ silicone resin has an M / Q value of 0.6-0.9 and a relative molecular mass of 3500-6000 g / mol.

6. The medical organic silicone pressure-sensitive adhesive having an antibacterial property according to claim 1, characterized by: The inhibitor is one or more of ethynylcyclohexanol, maleic acid diallyl ester, 2-methyl-3-butyn-2-ol, tetramethyldivinyl disiloxane, tetramethyltetraethenyl cyclosiloxane and 3-methyl-1-dodecyne-3-ol, and the addition amount of the inhibitor is 0.03-0.3 parts. The platinum catalyst is tetramethyldivinyl disiloxane chloroplatinic acid complex, and the mass content of platinum is 1000-5000 ppm.

7. The medical silicone pressure sensitive adhesive with antibacterial properties according to claim 1, characterized in that: The surfactant is octadecylamine polyoxyethylene ether AC-1815 and / or AC-1820.

8. The medical silicone pressure sensitive adhesive with antibacterial properties according to claim 1, characterized in that: The antibacterial group is one or more of methyl methacrylate octadecyl dimethylamine, methyl methacrylate heptadecyl dimethylamine, methyl methacrylate hexadecyl dimethylamine, methyl methacrylate pentadecyl dimethylamine, methyl methacrylate tetradecyl dimethylamine, methyl methacrylate tridecyl dimethylamine, methyl methacrylate dodecyl dimethylamine, methyl methacrylate undecyl dimethylamine, methyl methacrylate decyl dimethylamine, methyl methacrylate nonyl dimethylamine, methyl methacrylate octyl dimethylamine, methyl methacrylate heptyl dimethylamine, methyl methacrylate hexyl dimethylamine, methyl methacrylate pentyl dimethylamine, methyl methacrylate tetradecyl dimethylamine and methyl methacrylate trialkyl dimethylamine.

9. The method of producing a medical silicone pressure-sensitive adhesive having an antibacterial property according to any one of claims 1 to 8, characterized by, The method comprises the following steps: The surfactant 2-5 parts, antibacterial groups 0.5-1.5 parts are mixed first, then stirred uniformly under 2000-2500 rpm; then the methyl vinyl silicone rubber 10-20 parts, hydrogen-containing silicone oil 0.5-2 parts, solvent 40-50 parts, vinyl MQ silicone resin 5-20 parts, methyl MQ silicone resin 20-35 parts, inhibitor 0.03-0.3 parts are added into the reactor, the electric stirrer switch is opened, and the materials are mixed uniformly by slow stirring, until the mixture is completely mixed and uniform, to obtain the addition type silicone pressure-sensitive adhesive main agent, then the catalyst 0.04-0.4 parts is added, and after fully stirring, the prepared device is used to scrape the film, the adhesive is uniformly coated on the 50 μm PET film, then baked at 140℃ for 3 minutes, taken out, attached to the 50 μm PET film, and the PET substrate protective film is peeled off to test the peeling force performance.

10. The method of claim 9, wherein, The medical silicone pressure-sensitive adhesive with antibacterial performance is colorless and transparent in appearance, and has a viscosity of 1000-50000 cP.

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