High-elasticity antibacterial medical adhesive tape and preparation method thereof

Abstract

The application relates to the technical field of medical adhesive material preparation, and discloses a high-elasticity antibacterial medical adhesive tape and a preparation method thereof. The preparation method comprises the following steps: taking polydimethylsiloxane raw rubber as a base material, mixing modified white carbon black reinforcing filler, pre-dispersed silver-loaded zeolite antibacterial agent and platinum gold catalyst at low temperature, and preparing a base rubber material after closed mixing under nitrogen protection, obtaining an elastic base tape through extrusion molding, laser thickness measurement dynamic regulation and control and secondary vulcanization; a type paper coating and micro-gravure transfer coating process is matched and optimized, three-section curing and constant tension composite winding are adopted, and the high-elasticity antibacterial medical adhesive tape is prepared. Through filler modification, antibacterial agent pre-coating and whole-process precise process control, the base material elasticity and antibacterial durability are improved, the product performance is uniform and stable, the biocompatibility is good, and the product is suitable for clinical medical dressing and fixing requirements.

Description

Technical Field

[0001] This invention relates to the field of medical adhesive consumables preparation technology, specifically to a highly elastic antibacterial medical tape and its preparation method. Background Technology

[0002] Medical tape is an indispensable basic medical consumable in clinical nursing, wound management, and the fixation of various invasive catheters. Its use covers multiple scenarios including operating rooms, wards, emergency rooms, and home care, and it has stringent clinical requirements regarding material elasticity, fit, biocompatibility, and antibacterial properties. Currently, commonly used medical tapes in clinical practice are mostly based on non-woven fabrics, ordinary polyethylene film, or ordinary silicone. These conventional products have gradually revealed multiple shortcomings in adaptability during actual use, making it difficult to meet the refined needs of long-term application, fixation of mobile limbs, and care for sensitive skin. Ordinary non-woven fabric-based tapes have extremely poor elasticity and are prone to becoming tight, shifting, or even falling off when moving with limb joints. They cannot adapt to dynamic movements such as flexion, extension, and twisting of limbs, and their fixation stability is greatly reduced. Ordinary plastic film-based tapes have a certain degree of flexibility, but their elastic recovery performance is poor. After repeated stretching, they are prone to plastic deformation, losing their original tightness. In addition, the material has poor breathability, and prolonged application to the skin surface can easily cause local sweat accumulation, stuffy and red skin, and aggravate skin discomfort.

[0003] In terms of antibacterial properties, most conventional medical tapes do not undergo specific antibacterial modification treatment, relying solely on the inertness of the substrate to achieve limited antibacterial activity. Some products with added antibacterial components often use simple blending methods to directly mix the antibacterial agent into the substrate or adhesive layer without dispersion and encapsulation treatment. This results in uneven distribution of the antibacterial agent in the matrix, leading to localized agglomeration. This not only fails to achieve a uniform and long-lasting antibacterial effect but also easily causes skin sensitization risks due to localized antibacterial agent release, especially when used around broken skin or for people with sensitive skin, making it difficult to meet clinical standards for safety. Furthermore, the substrate reinforcement process of existing medical tapes has significant defects. Conventional silica reinforcing fillers have poor compatibility with the silicone matrix, resulting in insufficient interfacial bonding. During the mixing process, uneven filler dispersion and localized agglomeration are prone to occur, directly leading to uneven elastic modulus and inconsistent tensile resilience of the substrate. Over long-term use, the tape is prone to localized cracking and elastic fatigue failure, shortening the product's lifespan.

[0004] From the perspective of production processes, existing medical silicone tapes suffer from insufficient precision in the mixing, extrusion, and vulcanization processes. The mixing process lacks protective atmosphere control, making the rubber compound susceptible to oxidative deterioration due to heat. The extrusion molding stage lacks dynamic thickness monitoring and feedback control mechanisms, resulting in significant fluctuations in film thickness tolerance and low product consistency. The coating process primarily employs conventional doctor blade coating, leading to poor uniformity of the adhesive layer thickness, insufficient cross-linking and curing, unstable adhesive adhesion, and a tendency for residual adhesive and delamination. The release paper preparation process is simple, resulting in insufficient smoothness of the release layer, which easily pulls on the tape substrate during peeling, affecting the overall integrity of the tape. Furthermore, the existing production process lacks pretreatment processes for antibacterial agents and reinforcing fillers, hindering efficient compatibility between functional components and the matrix. The lax tension control during the composite winding stage makes the material prone to stress deformation, further reducing product yield and stability. To address the multiple shortcomings of existing medical tapes in terms of elasticity, antibacterial durability, manufacturing precision, and biocompatibility, the development of a highly elastic antibacterial medical tape that meets clinical needs, along with a refined and controllable manufacturing process, has become a crucial technological direction for optimization in the field of medical adhesive consumables. Summary of the Invention

[0005] The purpose of this invention is to provide a highly elastic antibacterial medical tape and its preparation method, so as to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, the present invention provides a highly elastic antibacterial medical tape and a method for preparing the same, the method comprising:

[0007] Polydimethylsiloxane raw rubber is plasticized on a two-roll mill until the Mooney viscosity reaches 50-60. Then, silica reinforcing filler, silver ion-containing antibacterial agent, and platinum catalyst are added to the mixture. The mixture is then mixed for 30 minutes at a temperature of 40-50℃ to obtain the first compound.

[0008] The first compound was transferred to a mixer and heated to 120°C under nitrogen protection. After discharge, it was cooled to room temperature to obtain the base material for high-elasticity antibacterial medical tape.

[0009] The base rubber compound is extruded and formed in a constant temperature vulcanization pipe using an extruder, and stretched to a thickness of 0.2-0.5 mm. Finally, it is subjected to secondary vulcanization at 150°C for 10 minutes in an oven to obtain the elastic base tape of the high elasticity antibacterial medical tape.

[0010] Preferably, the preparation method of the silica reinforcing filler for the high-elasticity antibacterial medical tape is as follows:

[0011] The fumed silica was heat-treated in a muffle furnace at 600°C for 2 hours to remove surface hydroxyl groups. Then it was dispersed in anhydrous ethanol, and γ-aminopropyltriethoxysilane coupling agent equivalent to 5% of the mass of fumed silica was added. The mixture was refluxed and stirred at 70°C for 4 hours. After the reaction was completed, it was filtered, washed and vacuum dried at 80°C to obtain modified fumed silica.

[0012] The modified silica and liquid polydimethylsiloxane were emulsified in a planetary mixer at a mass ratio of 1:2 at a speed of 2000 r / min for 1 hour to form a thixotropic paste, which is the silica reinforcing filler for the high-elasticity antibacterial medical tape.

[0013] The silver ion-containing antibacterial agent is silver-loaded zeolite powder, and its introduction process requires a pre-dispersion coating process, specifically:

[0014] Silver-loaded zeolite powder and polydimethylsiloxane raw rubber were mixed in an internal mixer at a mass ratio of 1:5 at 100°C for 10 minutes to coat the surface of the silver-loaded zeolite powder with the raw rubber molecular chains, forming the first coating layer. Then, 2% of dibutyltin dilaurate by mass of the silver-loaded zeolite powder was added and the mixture was continued to be mixed for 5 minutes to promote the complexation reaction between tin ions and silver ions, forming the second coating layer on the surface of the particles. After cooling, the mixture was pulverized and sieved to obtain a pre-dispersed silver ion-containing antibacterial agent masterbatch for later use.

[0015] Preferably, in the process of preparing the elastic base tape of the high-elasticity antibacterial medical tape, the extrusion molding process needs to be dynamically controlled in conjunction with a laser thickness measurement system, specifically:

[0016] An online laser thickness gauge is installed at the outlet of the constant temperature vulcanization pipeline to measure the thickness data of the film in real time during operation and transmit the data to the PLC controller. The PLC controller compares the measured thickness with the target thickness. When the deviation exceeds ±0.02mm, it automatically adjusts the screw speed of the extruder and the track speed of the traction machine to keep the thickness of the film within the set tolerance range until the entire roll of base tape is wound up.

[0017] Preferably, the release paper coating process of the high-elasticity antibacterial medical tape includes two steps: a base coating and a top coating. Specifically, glassine paper treated with silicone is selected as the base paper. First, a layer of water-based acrylic base coating agent is coated onto the surface of the base paper using a comma-shaped doctor blade, with a coating amount of 0.5 g / m². The coating is then dried in an oven at 80°C for 1 minute to form a base coating layer. Subsequently, a silicone top coating agent is coated onto the base coating layer, with a coating amount of 0.3 g / m². The coating is then cured at 120°C for 2 minutes to form an ultra-smooth release layer. After winding, the release paper of the high-elasticity antibacterial medical tape is obtained.

[0018] Preferably, the coating process of the high-elasticity antibacterial medical tape adopts a microgravure transfer coating method, specifically as follows: acrylate pressure-sensitive adhesive, isocyanate crosslinking agent, and leveling agent are mixed at a mass ratio of 100:2:0.5 and stirred at 50°C for 30 minutes to prepare an adhesive solution with a solid content of 50%; the adhesive solution is poured into the cells of the microgravure roller, controlling the cell depth to 30μm; through the counter-rotation of the microgravure roller and the back roller, the adhesive solution is quantitatively transferred to the elastic base surface of the high-elasticity antibacterial medical tape, resulting in a wet film thickness of 60μm; then, it undergoes three stages of heating in a 90°C drying tunnel: the first stage at 100°C / 30s, the second stage at 120°C / 60s, and the third stage at 130°C / 30s, to completely evaporate the solvent and complete the crosslinking reaction, forming a dry adhesive layer.

[0019] Preferably, the isocyanate crosslinking agent is a blocked isocyanate, and its deblocking reaction needs to be carried out simultaneously with the curing process after coating. Specifically, during the heating process in the drying tunnel after coating, when the temperature rises to 100°C, the blocked groups of the blocked isocyanate begin to decompose, releasing active -NCO groups. As the temperature continues to rise to 120-130°C, these active -NCO groups undergo addition reactions with the hydroxyl and amino groups in the acrylate pressure-sensitive adhesive to form a three-dimensional network crosslinking structure, thereby fixing the morphology of the dry adhesive layer. This process is completed in the drying tunnel without the need for additional post-curing equipment.

[0020] Preferably, the composite winding process of the high-elasticity antibacterial medical tape requires constant tension control. Specifically, after the elastic base of the high-elasticity antibacterial medical tape is coated with adhesive and cut, it is bonded to the release paper at the composite roller, and the bonding pressure is set to 0.3 MPa. During winding, a magnetic powder clutch is used as the tension actuator, and the winding tension is set to 5 N. As the roll diameter increases, the unwinding tension is automatically reduced through a PID algorithm, so that the elongation of the material is always controlled within 0.1% during the entire winding process, preventing irreversible stress deformation of the high-elasticity antibacterial medical tape during the winding process.

[0021] Preferably, when preparing the elastic base strip of the high-elasticity antibacterial medical tape, the rubber material discharged from the internal mixer needs to be thin-passed through a two-roll mill. Specifically, the rubber strip discharged from the internal mixer is wrapped around rollers on the two-roll mill, the roller gap is adjusted to 0.5mm, and three round trips of thin-passing operation are performed, each thin-passing time being 1 minute. The mechanical shearing force is used to break down the local agglomerates formed in the rubber material during the internal mixing process, so that the silica reinforcing filler and silver ion antibacterial agent for the high-elasticity antibacterial medical tape are more evenly distributed in the raw rubber matrix. After the thin-passing is completed, the strip is sheeted and then enters the subsequent extrusion molding process.

[0022] Preferably, the present invention also includes a highly elastic antibacterial medical tape, characterized in that it is prepared by the above-described method for preparing a highly elastic antibacterial medical tape.

[0023] Compared with the prior art, the beneficial effects of the present invention are:

[0024] This invention, through targeted optimization of substrate preparation, functional component pretreatment, and full-process process control, produces a highly elastic antibacterial medical tape that combines excellent elasticity, long-lasting antibacterial properties, and good biocompatibility. The entire preparation process achieves a synergistic improvement in uniform dispersion of functional components, precise control of production parameters, and stable product performance. Using polydimethylsiloxane as the base material, combined with a specially modified silica reinforcing filler, the hydroxyl groups on the silica surface are first removed through high-temperature heat treatment, followed by silane coupling agent modification and liquid polydimethylsiloxane emulsification treatment. This significantly improves the interfacial compatibility between the reinforcing filler and the silica matrix, eliminating interfacial gaps between the filler and the matrix. After mixing, the filler is uniformly dispersed in the adhesive without local agglomeration, giving the substrate stable high elasticity and tensile resilience. The tape can quickly return to its original shape after stretching with limb movement, without residual plastic deformation. During application, it does not cause a continuous feeling of tightness or pressure on the skin, adapting to the fixation needs of various joints and dynamic limbs, simultaneously optimizing both application comfort and fixation stability. The silver ion-containing antibacterial agent is processed using a pre-dispersion coating process. Through a double-layer coating structure, the silver-loaded zeolite powder is evenly encapsulated in the silicone matrix, preventing the antibacterial agent from being directly exposed and precipitated. This ensures the slow and stable release of silver ions, achieving a long-lasting and uniform antibacterial effect, inhibiting the growth of bacteria on the skin surface, reducing the risk of infection at the application site, and effectively avoiding skin sensitization problems caused by local accumulation of antibacterial agents. This enhances the product's biosafety and makes it suitable for application to sensitive skin and areas around broken skin.

[0025] The preparation process employs a segmented mixing technique. First, the rubber is plasticized and mixed at low temperature in a two-roll mill, then transferred to a nitrogen-protected internal mixer for heated mixing. This process isolates oxygen, preventing thermal oxidation and deterioration of the rubber compound, and preserving its original physicochemical properties. Subsequent thin-pass processing in the open mill further breaks down residual agglomerates within the rubber compound through mechanical shearing, allowing for more uniform distribution of reinforcing fillers and antibacterial agents within the matrix, thus improving the overall uniformity of the substrate performance. The extrusion molding stage utilizes a laser thickness measurement system for dynamic feedback control, monitoring the film thickness in real time and automatically adjusting the extrusion screw speed and traction speed to keep the film thickness tolerance within a minimal range. This ensures uniform thickness across the entire roll of base tape, avoiding elasticity differences and adhesion inconsistencies caused by uneven thickness, thus improving overall product consistency. The secondary vulcanization process, combined with a three-stage curing process after coating, ensures more complete vulcanization of the substrate and full cross-linking of the adhesive layer, forming a dense and stable three-dimensional network structure. This results in strong adhesion, no residual adhesive, no risk of delamination, and gentler skin removal during peeling, making dressing changes more convenient. The release paper employs a two-step coating process of primer and topcoat, forming a smooth and uniform release layer on the glassine paper surface. The release force is stable and moderate, ensuring smooth bonding and peeling without pulling on the tape substrate, thus maintaining the tape's structural integrity. The composite winding process utilizes constant tension PID automatic control, adjusting the winding tension in real time according to changes in roll diameter to keep material elongation at an extremely low level. This prevents irreversible stress deformation during winding, improving product yield and storage stability. The overall manufacturing process eliminates the need for complex post-curing equipment, ensuring smooth transitions between processes and strong process control. The resulting medical tape combines high elasticity, long-lasting antibacterial properties, good adhesion, and safety, fully adapting to various clinical dressing and fixation needs, optimizing the clinical user experience and nursing outcomes. Attached Figure Description

[0026] Figure 1 This diagram illustrates the working steps of a highly elastic antibacterial medical tape and its preparation method according to the present invention. Detailed Implementation

[0027] The present invention will be further described in detail below with reference to specific embodiments. These embodiments are only used to explain the present invention and do not constitute a limitation on the scope of protection of the present invention. Any non-creative improvements and substitutions made by those skilled in the art based on the technical solutions of the present invention after reading the content of the present invention shall fall within the scope of protection of the present invention. Unless otherwise specified, the raw materials and reagents used in the following embodiments are all commercially available medical-grade raw materials, and the equipment used are all conventional equipment for processing medical polymer materials. Performance tests are all performed in accordance with relevant national standards for medical polymer materials.

[0028] I. Raw material pretreatment process

[0029] 1. Preparation of high-elasticity antibacterial medical tape-specific silica reinforcing filler

[0030] Medical-grade fumed silica was weighed and placed in a muffle furnace for heat treatment at 600℃ for 2 hours to completely remove adsorbed free hydroxyl groups and moisture from the silica surface, preventing hydroxyl groups from causing foaming and decreased mechanical properties of the rubber compound during subsequent mixing. The heat-treated silica was then transferred to anhydrous ethanol and ultrasonically dispersed for 30 minutes to form a uniform suspension. Subsequently, 5% (by weight of silica) of γ-aminopropyltriethoxysilane coupling agent was added, and the mixture was heated to 70℃ and refluxed with stirring for 4 hours to allow the coupling agent to fully bond with the residual active sites on the silica surface, achieving hydrophobic surface modification. After the reaction, the solid product was separated by vacuum filtration and washed three times with anhydrous ethanol to remove unreacted coupling agent and impurities. The product was then dried in an 80℃ vacuum drying oven for 12 hours to obtain modified silica. Modified silica and medical-grade liquid polydimethylsiloxane were added to a planetary stirrer at a mass ratio of 1:2 and emulsified at a high speed of 2000 r / min for 1 hour. The modified silica was uniformly dispersed in the liquid polydimethylsiloxane by mechanical shearing force to form a thixotropic paste, which is the high-elasticity antibacterial silica reinforcing filler for medical tape. It was sealed for later use to prevent moisture absorption and clumping.

[0031] 2. Preparation of pre-dispersed coated silver ion-containing antibacterial agent

[0032] Medical-grade silver-loaded zeolite powder was selected as the silver ion-containing antibacterial agent, with a silver ion loading of 2.5 wt% and a particle size controlled at 200-300 mesh to ensure antibacterial efficacy and dispersibility. A double-layer pre-dispersion coating process was employed to treat the antibacterial agent. First, silver-loaded zeolite powder and polydimethylsiloxane raw rubber were added to a mixer at a mass ratio of 1:5, heated to 100℃, and mixed for 10 minutes. The strong shear force of the mixer caused the raw rubber molecular chains to fully entangle and coat the surface of the silver-loaded zeolite powder particles, forming the first organic coating layer. This prevented premature silver ion release and avoided antibacterial agent agglomeration during mixing. Subsequently, 2% (by weight) of dibutyltin dilaurate was added to the mixer, and mixing continued at a constant temperature for 5 minutes. This promoted a mild complexation reaction between tin and silver ions, forming a second stable complex coating layer on the particle surface, further slowing down the silver ion release rate and improving the compatibility of the antibacterial agent with the silicone rubber matrix. After the mixing is completed, the product is cooled to room temperature, pulverized using a high-speed pulverizer, and passed through a 200-mesh sieve to remove large particle agglomerates, thus obtaining a pre-dispersed coated silver ion antibacterial agent masterbatch. It is then stored in a light-proof and sealed container to prevent the silver ions from oxidizing and becoming inactive.

[0033] 3. Release paper pretreatment

[0034] Medical-grade glassine paper with a thickness of 80g / m² was selected as the release paper. The paper underwent prior passivation treatment with silicone, resulting in a smooth, burr-free, and pore-free surface that meets the hygiene standards for medical packaging materials. The release layer was prepared using a comma-shaped doctor blade coating process, consisting of two steps: a base coat and a top coat. First, a water-based acrylic base coat was applied to the surface of the paper, with the application amount strictly controlled at 0.5g / m². This was then dried in an 80℃ constant temperature oven for 1 minute to form a dense and smooth base coat, enhancing the adhesion between the subsequent top coat and the paper and preventing the release layer from peeling off. Next, a medical-grade silicone top coat was applied to the base coat surface, with the application amount controlled at 0.3g / m². This was then cured in a 120℃ constant temperature oven for 2 minutes to form a smooth, ultra-slippery release layer with stable peel strength. After cooling and winding, the release paper for medical tape was obtained, with the release force controlled at 3-5g / 25mm to avoid damage to the adhesive layer during peeling.

[0035] II. Implementation Examples

[0036] Example 1

[0037] See Figure 1 A method for preparing a highly elastic antibacterial medical tape, the specific steps of which are as follows:

[0038] (1) Preparation of base rubber compound: Weigh 100 parts of medical grade polydimethylsiloxane raw rubber, add it to a two-roll mill, and plasticize it at room temperature. During the process, adjust the roller gap multiple times and repeatedly pass through the mill for plasticizing until the Mooney viscosity of the raw rubber stabilizes at 50. Control the temperature during the plasticizing process to not exceed 40℃ to prevent premature cross-linking of the raw rubber. After plasticizing, add 35 parts of the above-mentioned special precipitated silica reinforcing filler, 4 parts of pre-dispersed coated silver ion antibacterial agent masterbatch, and 0.5 parts of platinum catalyst to the mill. Control the temperature of the mill to 40℃ and mix at a constant temperature for 30 minutes. During the mixing process, continuously roll and turn the rubber to ensure that each component is evenly dispersed, without white spots or agglomeration, to obtain the first compound.

[0039] (2) Internal mixing and thin-pass treatment: The first compound was transferred to a closed internal mixer, and high-purity nitrogen was introduced to replace the air in the internal mixer to create an oxygen-free protective atmosphere to prevent the rubber compound from oxidizing and degrading during the mixing process. The temperature was raised to 120°C and the mixture was kept at a constant temperature for 20 minutes to further crosslink and fuse the components and improve the density of the rubber compound. After the internal mixing was completed, the rubber compound was discharged and allowed to cool naturally to room temperature. Then it was fed back into a two-roll mill, and the roll gap was adjusted to 0.5 mm. Three round-trip thin-pass treatments were performed, each lasting 1 minute. The strong mechanical shear force was used to break down the local agglomerates inside the rubber compound and optimize the dispersion uniformity of the filler and antibacterial agent. After the thin-pass treatment was completed, the rubber compound was sheeted to obtain the base rubber compound for high-elasticity antibacterial medical tape.

[0040] (3) Elastic base tape extrusion molding and vulcanization: The base rubber compound is added to a single-screw extruder, which is equipped with a constant temperature vulcanization pipeline. The pipeline temperature is controlled in stages: 80℃ for the first stage, 110℃ for the second stage, and 140℃ for the third stage, so as to achieve gradual plasticization and preliminary vulcanization of the rubber compound. During the extrusion process, an online laser thickness measurement system is used for dynamic feedback control. A high-precision online laser thickness gauge is set up at the outlet of the constant temperature vulcanization pipeline to collect the film thickness data in real time and transmit it to the PLC controller. The PLC controller compares the measured thickness with the target thickness of 0.2mm. When the deviation exceeds ±0.02mm, the screw speed of the extruder and the speed of the traction machine track are automatically adjusted to control the film thickness in a closed loop. The extruded film is stretched to 0.2mm and sent to a 150℃ constant temperature oven for secondary vulcanization for 10 minutes to completely complete the cross-linking reaction, eliminate internal stress, and obtain a highly elastic antibacterial medical tape elastic base tape.

[0041] (4) Preparation of pressure-sensitive adhesive: Weigh 100 parts of medical grade acrylic pressure-sensitive adhesive, 2 parts of blocked isocyanate crosslinking agent, and 0.5 parts of polyether modified siloxane leveling agent. Mix them and place them in a constant temperature stirring kettle. Control the temperature at 50°C and stir at 300 r / min for 30 minutes to prepare a uniform adhesive with a solid content of 50%. Let it stand for 15 minutes to remove bubbles generated during stirring.

[0042] (5) Microgravure transfer coating: The adhesive is coated onto the surface of the elastic substrate using a microgravure transfer coating process. The depth of the microgravure roller is 30 μm. The microgravure roller and the back roller are rotated in opposite directions with a speed ratio of 1:1.2. The adhesive is transferred quantitatively, and the wet film thickness is 60 μm. The coated substrate is then sent into a three-stage constant temperature drying tunnel. The first stage is at 100℃ and cured for 30 seconds, during which the blocked isocyanate begins to unblock and release active -NCO groups. The second stage is at 120℃ and cured for 60 seconds, during which the active -NCO groups fully react with the hydroxyl and amino groups in the acrylate pressure-sensitive adhesive. The third stage is at 130℃ and cured for 30 seconds, during which the three-dimensional network cross-linked structure is completed, the solvent evaporates completely, and a stable dry adhesive layer is formed.

[0043] (6) Composite winding: The coated elastic base tape and the pretreated release paper are bonded together at the composite roller, and the composite pressure is controlled at 0.3MPa to ensure tight bonding without bubbles or wrinkles. The winding process uses a magnetic powder clutch as the tension actuator. The initial winding tension is set to 5N. The roll diameter change is monitored in real time through a PID algorithm. As the roll diameter increases, the unwinding tension is automatically and linearly reduced. The material elongation is controlled to be ≤0.1% throughout the process to avoid irreversible stress deformation. After winding, the tape is cut into standard widths and vacuum-packed to obtain the finished high-elasticity antibacterial medical tape.

[0044] Example 2

[0045] The difference between this embodiment and Example 1 is that the Mooney viscosity of the polydimethylsiloxane raw rubber after plasticizing is controlled at 55, the amount of special precipitated silica reinforcing filler added is 40 parts, the amount of pre-dispersed coated silver ion antibacterial agent masterbatch added is 5 parts, the mixing temperature of the open mill is 45℃, and the target thickness of the elastic base strip is 0.35mm. The remaining raw material ratios, process steps, and process parameters are completely consistent with those of Example 1.

[0046] Example 3

[0047] The difference between this embodiment and Example 1 is that the Mooney viscosity of the polydimethylsiloxane raw rubber after plasticizing is controlled at 60, the amount of special precipitated silica reinforcing filler added is 45 parts, the amount of pre-dispersed coated silver ion antibacterial agent masterbatch added is 6 parts, the mixing temperature of the open mill is 50℃, the target thickness of the elastic base strip is 0.5mm, and the remaining raw material ratios, process steps, and process parameters are completely consistent with Example 1.

[0048] III. Comparative Example

[0049] Comparative Example 1

[0050] This comparative example is a method for preparing medical tape without modified silica filler. The difference between this example and Example 2 is that unmodified ordinary fumed silica is directly used to replace the special modified silica reinforcing filler, and no coupling agent modification or liquid polydimethylsiloxane emulsification treatment is performed. All other raw material ratios, process steps, and process parameters are completely consistent with Example 2.

[0051] Comparative Example 2

[0052] This comparative example is a method for preparing medical tape without using pre-dispersed antibacterial agents. The difference from Example 2 is that ordinary silver-loaded zeolite powder is directly used to replace the pre-dispersed coated silver ion-containing antibacterial agent masterbatch, and no double-layer coating treatment is performed. It is directly mixed with raw rubber. The remaining raw material ratios, process steps, and process parameters are completely consistent with Example 2.

[0053] Comparative Example 3

[0054] This comparative example is a method for preparing medical tape that omits the internal mixing and thin-passing process and dynamic thickness measurement process. The difference between this example and Example 2 is that the first compound rubber is not subjected to internal mixing and thin-passing treatment, but is directly extruded and molded. During the extrusion process, laser thickness measurement and dynamic feedback control are not used. The thickness of the film is controlled only by fixing the roller gap and rotation speed. The other raw material ratios, process steps, and process parameters are completely consistent with Example 2.

[0055] IV. Performance Testing and Result Analysis

[0056] (a) Testing methods

[0057] 1. Mechanical property testing: In accordance with GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber", an electronic universal testing machine was used for testing, with a tensile speed of 500 mm / min, to detect tensile strength, elongation at break, and elastic recovery rate.

[0058] 2. Antibacterial performance test: Referring to GB / T 20944.3-2008 "Evaluation of antibacterial properties of textiles - Part 3: Shaking method", two common clinical pathogens, Escherichia coli and Staphylococcus aureus, were selected to test the antibacterial rate.

[0059] 3. Appearance and dimensional accuracy testing: A high-precision thickness gauge is used to check the thickness tolerance of the film, and the surface of the tape is visually inspected to see if it is flat and free of agglomerated particles, bubbles, and wrinkles;

[0060] 4. Adhesion performance test: Test the peel strength and tack of the tape against medical skin-simulating materials to evaluate its clinical use adhesion and anti-curling performance.

[0061] Table 1: Core Performance Test Data of Examples and Comparative Examples

[0062]

[0063] From a mechanical performance perspective, the tensile strength, elongation at break, and elastic recovery rate of Examples 1-3 are significantly better than those of Comparative Examples 1 and 3, with Example 2 exhibiting the best overall mechanical properties. Example 2 achieved a tensile strength of 10.5 MPa, an elongation at break of 520%, and an elastic recovery rate of 98.5%, far exceeding the conventional mechanical performance requirements for medical silicone rubber tapes. Comparative Example 1, due to the use of unmodified ordinary silica, had poor compatibility between the filler and the silicone rubber matrix, leading to agglomeration during mixing and the formation of stress concentration points. This resulted in a tensile strength of only 6.3 MPa, an elongation at break of 310%, and an elastic recovery rate of 82.3%, significantly reducing its mechanical properties and failing to meet the requirements for high-elasticity medical tapes. In clinical use, it was prone to problems such as tensile breakage, insufficient rebound, and loosening after application. Comparative Example 3 omitted the intensive mixing and dynamic thickness measurement processes, resulting in uneven filler dispersion within the rubber compound, localized agglomerates, and a large thickness tolerance in the film. This led to significant loss of mechanical properties; tensile strength decreased by 27.6% compared to Example 2, elongation at break decreased by 26.9%, elastic recovery rate was only 85.7%, and dimensional accuracy was poor, making it unsuitable for the delicate clinical bandaging scenarios. In Examples 1-3, with gradual adjustments to Mooney viscosity and filler addition, the mechanical properties showed a trend of first increasing and then decreasing. At a Mooney viscosity of 55 and a filler addition of 40 parts, the matrix crosslinking density and filler reinforcement effect reached an optimal balance, resulting in peak mechanical properties.

[0064] From the perspective of antibacterial performance, Examples 1-3 all showed antibacterial rates of ≥99.2% against Escherichia coli and Staphylococcus aureus, demonstrating excellent long-lasting antibacterial effects and meeting the antibacterial hygiene standards for medical consumables. Comparative Example 2, due to the lack of a pre-dispersion coating process, directly mixed ordinary silver-loaded zeolite powder with raw rubber, resulting in severe particle agglomeration, uneven silver ion distribution, and premature precipitation and inactivation of some silver ions during mixing, led to a significant decrease in the antibacterial rate. The antibacterial rate against Escherichia coli was only 86.3%, and against Staphylococcus aureus only 87.1%, failing to effectively inhibit bacterial growth around clinical wounds and posing a risk of wound infection. Comparative Examples 1 and 3 showed slightly lower antibacterial performance than Example 2, mainly due to uneven filler dispersion and insufficient density of the adhesive, resulting in irregular silver ion release channels. However, they still generally met the basic antibacterial requirements, indicating that the pre-dispersion coating process is a core technical point for ensuring antibacterial effects.

[0065] Analyzing from the perspectives of dimensional accuracy and adhesion performance, Examples 1-3 employ laser thickness measurement and dynamic feedback control, with thickness tolerances all controlled within ±0.02mm. Example 2 exhibits a thickness tolerance of only ±0.012mm, demonstrating extremely high dimensional accuracy. Adhesion holding time is ≥72h for all examples, with Example 2 achieving ≥96h. No lifting or detachment occurs after skin application, making it suitable for long-term clinical bandaging needs. Comparative Example 1 has a larger thickness tolerance, and uneven filler dispersion leads to a rough surface, resulting in adhesion holding time of only ≥24h, making it prone to detachment. Comparative Example 3 lacks dynamic thickness measurement control, resulting in a thickness tolerance of ±0.042mm. Uneven film thickness leads to uneven stress during application, resulting in adhesion holding time of only ≥36h, making it less practical.

[0066] Table 2: Analysis of Core Process Parameters and Their Functions in the Examples

[0067]

[0068] Table 2 describes the gradient changes of core process parameters in the embodiments, clarifying the regulatory role of each parameter on the performance of the tape, and providing precise parameter basis for industrial production. The Mooney viscosity of raw rubber directly affects the processing fluidity and final crosslinking density of the rubber compound. When the Mooney viscosity is 50, the rubber compound has excessive fluidity, and fillers are prone to sedimentation during mixing, resulting in a low crosslinking density and weak mechanical properties. When the Mooney viscosity is 60, the rubber compound has poor fluidity, increasing the difficulty of mixing, causing uneven dispersion of fillers, and making it prone to local agglomeration, resulting in a slight decrease in mechanical properties. When the Mooney viscosity is 55, the fluidity and plasticity of the rubber compound are balanced, the components are evenly dispersed during mixing, and the crosslinking density is moderate, ensuring both smooth processing and optimal mechanical properties.

[0069] The amount of special silica reinforcing filler added is a key factor affecting the elasticity and strength of the tape. When the amount added is 35 parts, the reinforcing effect is insufficient, and the tensile strength and elasticity of the tape are low. When the amount added is 45 parts, the filler is excessive and exceeds the bearing limit of the silicone rubber matrix, which easily forms agglomerates, destroys the continuity of the matrix, and leads to a decline in mechanical properties. When the amount added is 40 parts, the filler is evenly dispersed in the matrix and forms a complete reinforcing network, which not only greatly improves the tensile strength, but also retains the original high elasticity of silicone rubber, achieving the best balance between strength and elasticity.

[0070] The mixing temperature directly affects the component dispersion effect. At 40℃, the mixing rate is slow, and the components are not sufficiently dispersed. At 50℃, the temperature is too high, which can easily lead to premature activation of the platinum catalyst and premature cross-linking of the rubber compound, forming gel particles. At 45℃, the mixing efficiency is guaranteed, ensuring uniform dispersion of fillers, antibacterial agents, and catalysts, while avoiding premature cross-linking and ensuring stable rubber compound quality. The secondary vulcanization uses a parameter of 150℃ / 10min, which can completely complete the cross-linking reaction between the silicone rubber matrix and the pressure-sensitive adhesive layer, effectively eliminating the internal stress generated during extrusion and coating, significantly improving the elastic recovery rate, ensuring that the tape rebounds quickly after stretching, and feels comfortable against the skin without tightness.

[0071] Table 3: Performance Comparison Table of Optimized Process of the Invention and Traditional Process

[0072]

[0073] Table 3 compares the core indicators of the optimized process of this invention (average values ​​of Examples 1-3) with those of the traditional process (average values ​​of Comparative Examples 1-3), intuitively demonstrating the advanced nature and practicality of the technical solution of this invention. This invention achieves significant improvements in all performance aspects through optimization of five core processes: preparation of modified silica filler, pre-dispersion coating with antibacterial agent, intensive mixing and thin-pass refining, dynamic control by laser thickness measurement, and constant tension composite winding.

[0074] In terms of mechanical properties, the average tensile strength is increased by 27.3%, the average elongation at break by 24.2%, and the average elastic recovery rate by 11.4%, completely solving the problems of insufficient strength, poor elasticity, and slow rebound of traditional medical silicone rubber tapes. It is suitable for bandaging joints, limbs, and other active areas, is less prone to breakage after stretching, and provides a tight, secure fit, significantly improving clinical comfort. Regarding antibacterial properties, the average antibacterial rate is increased by 8.9%, reaching 99.5%, achieving long-lasting and potent antibacterial effects, effectively blocking bacterial growth, reducing the risk of clinical wound infection, and meeting the high-standard medical requirements of operating rooms, wound care, and other similar settings.

[0075] In terms of dimensional accuracy, this invention achieves a 100% thickness accuracy rate, a 60% improvement over traditional processes. The film is uniformly thick, with a smooth and even surface, good adhesive layer uniformity, and stable peel force. This significantly increases the finished product qualification rate after slitting, reducing production costs. Furthermore, the optimized process enables continuous industrial production with strong process stability and high product quality consistency. It overcomes the shortcomings of traditional processes, such as uneven distribution, large dimensional deviations, and significant performance fluctuations, possessing extremely high industrialization value.

[0076] This invention solves the technical problems of insufficient elasticity, poor antibacterial effect, low dimensional accuracy, and easy agglomeration and detachment in traditional medical tapes by specifically optimizing the entire process of raw material pretreatment, mixing, molding, coating, and lamination. Examples 1-3 can all produce high-elasticity antibacterial tapes that meet medical standards. Among them, Example 2 is the optimal example, with the most reasonable raw material ratio and process parameter combination, resulting in the best overall performance. Its tensile strength, elongation at break, elastic recovery rate, antibacterial rate, dimensional accuracy, and tackiness all reach industry-leading levels.

[0077] Comparative Examples 1-3 were set up from three dimensions: filler modification, antibacterial agent treatment, and omission of core processes, respectively, to fully verify the necessity and irreplaceability of the special modified silica reinforcing filler, pre-dispersed antibacterial agent coating, and the internal mixing and laser thickness measurement dynamic control process. The absence of any core process will lead to a significant decrease in the mechanical properties, antibacterial properties, and dimensional accuracy of the tape, making it impossible to meet the clinical requirements for high elasticity, long-lasting antibacterial effect, and precise adhesion.

[0078] The high-elasticity antibacterial medical tape prepared by this invention has excellent biocompatibility, no skin irritation, and is suitable for various clinical bandaging scenarios, especially for joint movement areas and wound care areas. It has the advantages of high elasticity, long-lasting antibacterial effect, precise size, and firm adhesion. The process can be continuously mass-produced, which meets the requirements of large-scale production of medical consumables and has broad clinical application prospects and market value.

[0079] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing a highly elastic antibacterial medical tape, characterized in that, Includes the following steps: Polydimethylsiloxane raw rubber is plasticized on a two-roll mill until the Mooney viscosity reaches 50-60. Then, silica reinforcing filler, silver ion-containing antibacterial agent, and platinum catalyst are added to the mixture. The mixture is then mixed for 30 minutes at a temperature of 40-50℃ to obtain the first compound. The first compound was transferred to a mixer and heated to 120°C under nitrogen protection. After discharge, it was cooled to room temperature to obtain the base material for high-elasticity antibacterial medical tape. The base rubber compound is extruded and formed in a constant temperature vulcanization pipe using an extruder, and stretched to a thickness of 0.2-0.5 mm. Finally, it is subjected to secondary vulcanization at 150°C for 10 minutes in an oven to obtain the elastic base tape of the high elasticity antibacterial medical tape.

2. The method for preparing a highly elastic antibacterial medical tape according to claim 1, characterized in that, The preparation method of the silica reinforcing filler for the high-elasticity antibacterial medical tape is as follows: The fumed silica was heat-treated in a muffle furnace at 600°C for 2 hours to remove surface hydroxyl groups. Then it was dispersed in anhydrous ethanol, and γ-aminopropyltriethoxysilane coupling agent equivalent to 5% of the mass of fumed silica was added. The mixture was refluxed and stirred at 70°C for 4 hours. After the reaction was completed, it was filtered, washed and vacuum dried at 80°C to obtain modified fumed silica. The modified silica and liquid polydimethylsiloxane were emulsified in a planetary mixer at a mass ratio of 1:2 at a speed of 2000 r / min for 1 hour to form a thixotropic paste, which is the silica reinforcing filler for the high-elasticity antibacterial medical tape.

3. The method for preparing a highly elastic antibacterial medical tape according to claim 1, characterized in that, The silver ion-containing antibacterial agent is silver-loaded zeolite powder, and its introduction process requires a pre-dispersion coating process, specifically: Silver-loaded zeolite powder and polydimethylsiloxane raw rubber were mixed in an internal mixer at a mass ratio of 1:5 at 100°C for 10 minutes to coat the surface of the silver-loaded zeolite powder with the raw rubber molecular chains, forming the first coating layer. Then, 2% of dibutyltin dilaurate by mass of the silver-loaded zeolite powder was added and the mixture was continued to be mixed for 5 minutes to promote the complexation reaction between tin ions and silver ions, forming the second coating layer on the surface of the particles. After cooling, the mixture was pulverized and sieved to obtain a pre-dispersed silver ion-containing antibacterial agent masterbatch for later use.

4. The method for preparing a highly elastic antibacterial medical tape according to claim 1, characterized in that, In the process of preparing the elastic base tape of the aforementioned high-elasticity antibacterial medical tape, the extrusion molding process requires dynamic feedback control in conjunction with a laser thickness measurement system, specifically: An online laser thickness gauge is installed at the outlet of the constant temperature vulcanization pipeline to measure the thickness data of the film in real time during operation and transmit the data to the PLC controller. The PLC controller compares the measured thickness with the target thickness. When the deviation exceeds ±0.02mm, it automatically adjusts the screw speed of the extruder and the track speed of the traction machine to keep the thickness of the film within the set tolerance range until the entire roll of base tape is wound up.

5. The method for preparing a highly elastic antibacterial medical tape according to claim 1, characterized in that, The release paper coating process of the high-elasticity antibacterial medical tape includes two steps: a base coating and a top coating. Specifically, glassine paper treated with silicone is selected as the base paper. First, a layer of water-based acrylic base coating agent is coated onto the surface of the base paper using a comma-shaped doctor blade, with a coating amount of 0.5 g / m². The coating is then dried in an oven at 80°C for 1 minute to form a base coating layer. Subsequently, a silicone top coating agent is coated onto the base coating layer, with a coating amount of 0.3 g / m². The coating is then cured at 120°C for 2 minutes to form an ultra-smooth release layer. After winding, the release paper of the high-elasticity antibacterial medical tape is obtained.

6. The method for preparing a highly elastic antibacterial medical tape according to claim 1, characterized in that, The coating process of the high-elasticity antibacterial medical tape adopts a microgravure transfer coating method. Specifically, acrylate pressure-sensitive adhesive, isocyanate crosslinking agent, and leveling agent are mixed at a mass ratio of 100:2:0.5 and stirred at 50°C for 30 minutes to prepare an adhesive solution with a solid content of 50%. The adhesive solution is poured into the cells of the microgravure roller, controlling the cell depth to be 30μm. Through the counter-rotation of the microgravure roller and the back roller, the adhesive solution is quantitatively transferred to the elastic base surface of the high-elasticity antibacterial medical tape, and the wet film thickness is 60μm. Then, it is heated in a 90°C oven in three stages: the first stage is 100°C / 30s, the second stage is 120°C / 60s, and the third stage is 130°C / 30s, so that the solvent is completely evaporated and the crosslinking reaction is completed to form a dry adhesive layer.

7. The method for preparing a highly elastic antibacterial medical tape according to claim 6, characterized in that, The isocyanate crosslinking agent is a blocked isocyanate, and its deblocking reaction needs to be carried out simultaneously with the curing process after coating. Specifically, during the heating process in the drying tunnel after coating, when the temperature rises to 100°C, the blocked groups of the blocked isocyanate begin to decompose, releasing active -NCO groups. As the temperature continues to rise to 120-130°C, these active -NCO groups undergo addition reactions with the hydroxyl and amino groups in the acrylate pressure-sensitive adhesive to form a three-dimensional network crosslinking structure, thereby fixing the morphology of the dry adhesive layer. This process is completed in the drying tunnel and does not require additional post-curing equipment.

8. The method for preparing a highly elastic antibacterial medical tape according to claim 1, characterized in that, The composite winding process of the high-elasticity antibacterial medical tape requires constant tension control. Specifically, after the elastic base of the high-elasticity antibacterial medical tape is coated with adhesive and cut, it is bonded to the release paper at the composite roller, and the bonding pressure is set to 0.3 MPa. During winding, a magnetic powder clutch is used as the tension actuator, and the winding tension is set to 5 N. As the roll diameter increases, the unwinding tension is automatically reduced through a PID algorithm, so that the elongation of the material is always controlled within 0.1% during the entire winding process, preventing irreversible stress deformation of the high-elasticity antibacterial medical tape during the winding process.

9. The method for preparing a highly elastic antibacterial medical tape according to claim 1, characterized in that, In preparing the elastic base strip of the high-elasticity antibacterial medical tape, the rubber material discharged from the internal mixer needs to be thin-passed through a two-roll mill. Specifically, the rubber strip discharged from the internal mixer is wrapped around rollers on the two-roll mill, the roller gap is adjusted to 0.5mm, and three round trips of thin-passing operation are performed, each thin-passing time being 1 minute. The mechanical shearing force is used to break down the local agglomerates formed in the rubber material during the internal mixing process, so that the special silica reinforcing filler and silver ion antibacterial agent for the high-elasticity antibacterial medical tape are more evenly distributed in the raw rubber matrix. After the thin-passing is completed, the strip is sheeted out and then enters the subsequent extrusion molding process.

10. A highly elastic antibacterial medical tape, characterized in that, It is prepared by the method described in any one of claims 1 to 9 for a high-elasticity antibacterial medical tape.

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