Preparation method of antibacterial writable invisible adhesive tape

Abstract

The invention relates to a preparation method of an antibacterial writable invisible adhesive tape, and belongs to the technical field of adhesive tape preparation. Polyvinyl chloride resin, a plasticizer and a heat stabilizer are stirred, plasticized and calendered into a transparent base material; the preparation method comprises the following steps: carrying out ultrasonic reaction on a transparent base material, absolute ethyl alcohol, 2-aminooxazole, epoxypropane and a boron trifluoride diethyl etherate complex to obtain a modified transparent base material; the preparation method comprises the following steps: ultrasonically dispersing nano-silver particles, a chitosan derivative and a dispersing agent into deionized water to obtain antibacterial dispersion liquid; coating the antibacterial dispersion liquid on a transparent substrate, and drying to form an antibacterial layer; stirring acrylate monomers, hydroxyethyl acrylate, an initiator and propylene glycol methyl ether acetate for reaction to obtain a pressure-sensitive adhesive; and coating the other side of the base material with the antibacterial layer with a pressure-sensitive adhesive, compounding the pressure-sensitive adhesive with a release film, and curing to obtain the antibacterial writable invisible adhesive tape. The prepared adhesive tape meets basic use requirements of invisible adhesive tapes, and is excellent in antibacterial effect and good in writing effect.

Description

Technical Field

[0001] This invention relates to the field of tape preparation technology, and in particular to a method for preparing an antibacterial, writable, invisible tape. Background Technology

[0002] Invisible tape, due to its excellent transparency and minimal traceability after application, is widely used in document repair, paper adhesion, and office marking. With increasing health awareness and expanding applications, particularly in medical record writing and children's stationery, higher demands are being placed on the antibacterial properties of invisible tape. However, traditional invisible tape has a smooth surface and often uses ordinary pressure-sensitive adhesive, making it difficult to write on and prone to erasing, thus failing to meet the needs of direct writing and marking.

[0003] Chinese Patent CN113150725A discloses a process for preparing a high-adhesion adhesive tape, comprising the following steps: S1. Raw material preparation: taking a substrate, coating liquid, and release film; S2. Substrate coating: uniformly coating one side of the substrate with the coating liquid, and bonding the other side of the substrate to the release film; S3. Pre-curing treatment: drying the product after S2 in a tunnel oven for pre-curing treatment; S4. Curing treatment: placing the product after S3 in a temperature-controlled oven for curing treatment; S5. Tempering treatment: placing the product after S4 in a medium-low temperature oven for tempering treatment to obtain the high-adhesion adhesive tape finished product.

[0004] Chinese Patent CN114716931A discloses a tape preparation process, which includes the following steps: S1, preparing a substrate; S2, preparing adhesive layer ingredients; S3, uniformly coating the adhesive layer ingredients onto one side of the substrate to obtain a tape; S4, winding, rewinding, cutting, sampling, and packaging the obtained tape; in step S1, a superhydrophobic PET film is used as the substrate; in step S2, an organosilicon pressure-sensitive adhesive is used as the adhesive layer ingredient.

[0005] In the existing technology, some antibacterial tapes achieve antibacterial function by adding a single antibacterial agent, but the antibacterial effect is not long-lasting and is easy to bleed out; while writable tapes mostly achieve this by roughening the surface of the adhesive layer, sacrificing the transparency and aesthetics of the tape. Summary of the Invention

[0006] To address the above problems, this invention provides a method for preparing antibacterial writable invisible tape, the steps of which are as follows: S1: Mix 70-100 parts of polyvinyl chloride resin, 30-45 parts of plasticizer, and 1-5 parts of heat stabilizer, plasticize at 150-170℃ for 10-20 minutes, and calender into a transparent substrate with a thickness of 20-30μm. S2: The transparent substrate is laid flat in an ultrasonic reactor. 84-168 parts of anhydrous ethanol, 20-30 parts of 2-aminooxazole, and 5-8 parts of propylene oxide are added to the reactor. The permeation supply device at the bottom of the reactor is turned on, and 0.2-0.5 parts of boron trifluoride diethyl ether complex are added. The ultrasonic probe is inserted into the liquid material, the ultrasonic instrument is turned on, and the material is dripped onto the surface of the substrate using the top dripping device. The ultrasonic reaction is continued for 2.5-4.5 hours. After the reaction is completed, the ultrasonic instrument is turned off, the anhydrous ethanol is removed by vacuum distillation, the substrate is cooled to room temperature, and dried to obtain the modified transparent substrate. S3: Disperse 5-10 parts of nano-silver particles, 15-25 parts of chitosan derivative, and 1-3 parts of dispersant in 200-300 parts of deionized water, and sonicate for 20-30 minutes to obtain an antibacterial dispersion; uniformly coat the antibacterial dispersion onto a modified transparent substrate, and dry to form an antibacterial layer with a thickness of 3-5 μm; S4: Mix 70-100 parts of acrylate monomer, 8-15 parts of hydroxyethyl acrylate, and 0.5-1.5 parts of initiator, and react at 60-80℃ for 2-4 hours. Add 1-5 parts of propylene glycol methyl ether acetate, stir evenly, and obtain pressure-sensitive adhesive. S5: Apply pressure-sensitive adhesive to the other side of the substrate with the antibacterial layer, with a coating thickness of 15-25μm; laminate the film coated with pressure-sensitive adhesive with a polyethylene terephthalate release film with a thickness of 25-50μm, cure at 100-120℃ for 10-15min, flatten by calendering rollers, cool to room temperature, and cut by a cutting machine to obtain antibacterial writable invisible tape.

[0007] As a preferred embodiment of the present invention, the plasticizer is a mixture of dioctyl phthalate and epoxidized soybean oil in a mass ratio of 2-3:1.

[0008] As a preferred embodiment of the present invention, the heat stabilizer is a calcium-zinc composite stabilizer JCZ-100 or JCZ-201.

[0009] As a preferred embodiment of the present invention, the chitosan derivative is carboxymethyl chitosan or hydroxypropyl chitosan.

[0010] As a preferred embodiment of the present invention, the dispersant is sodium dodecylbenzenesulfonate or Tween-80.

[0011] As a preferred embodiment of the present invention, the drying temperature of S3 is 80-100℃ and the drying time is 5-10min.

[0012] As a preferred embodiment of the present invention, the acrylate monomer is a mixture of methyl methacrylate and butyl acrylate in a mass ratio of 1-2:3.

[0013] As a preferred embodiment of the present invention, the initiator is ammonium persulfate or azobisisobutyronitrile.

[0014] As a preferred embodiment of the present invention, the S5 coating method adopts microgravure coating, the pressure of the calendering roller is 0.3-0.5MPa, and the temperature is 40-50℃.

[0015] As a preferred embodiment of the present invention, the vacuum degree of the S2 vacuum distillation is 0.06-0.08 MPa and the temperature is 40-45℃.

[0016] Reaction mechanism: Ultrasonic treatment enhances the mixing uniformity of raw materials. The fluoroboron group (Lewis acid) in the boron trifluoride diethyl ether complex effectively activates the epoxy ring of propylene oxide, causing it to open and generate oxygen anions. These oxygen anions further undergo an addition reaction with the amino group of 2-aminooxazole to form stable functional groups. Simultaneously, the vinyl chloride radicals on the surface of the polyvinyl chloride (PVC) substrate can achieve stable bonding with the hydroxyl groups generated during the reaction through covalent bonding and hydrogen bonding. This successfully fixes antibacterial functional groups on the substrate surface while avoiding damage to the original transparent structure of the substrate, thus ensuring its light transmittance. Furthermore, after the above modification, the substrate surface forms a suitable microstructure, which does not affect the overall light transmittance and provides a good foundation for the subsequent adhesion of the antibacterial layer, while also optimizing the surface's compatibility with ink. The modified substrate also improves the interfacial bonding strength with the subsequent pressure-sensitive adhesive, helping to ensure the adhesive performance of the tape.

[0017] Technical effect 1. It imparts long-lasting antibacterial properties to invisible tape, effectively inhibiting the growth of common pathogenic bacteria on the tape surface, reducing hygiene and safety hazards caused by tape use, and making it suitable for daily office, home, and other scenarios with certain hygiene requirements.

[0018] 2. It can maintain the high light transmittance of the substrate, ensuring that the tape will not obscure the text, patterns, or other information on the surface of the adhered object after it is applied, thus fully meeting the core requirement of invisible tape for the "invisible" function.

[0019] 3. Optimize the writing adaptability of the tape surface, allowing ink to adhere smoothly to the tape surface, resulting in clear and stable handwriting, significantly improving the multi-functional user experience of the tape and expanding its application scenarios. Detailed implementation methods. To enable those skilled in the art to better understand the technical solutions in this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the examples. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of this application.

[0020] 1. Light transmittance: According to GB / T2410-2008 "Determination of light transmittance and haze of transparent plastics", a light transmittance and haze meter was used for testing.

[0021] 2. Adhesion strength: Tested using an electronic tensile testing machine in accordance with GB / T2792-2014 "Test method for 180° peel strength of pressure-sensitive adhesive tape".

[0022] 3. Antibacterial rate: According to QB / T2591-2003 "Test methods and antibacterial effects of antibacterial plastics", Escherichia coli and Staphylococcus aureus were used as test strains to calculate the antibacterial rate.

[0023] 4. Writing performance: A 10-person evaluation group was invited to write on the tape using ballpoint pens and gel pens respectively. The group scored the writing on two dimensions: writing smoothness and handwriting clarity (out of 10). The average score was taken as the writing clarity score. Example

[0024] A method for preparing an antibacterial, writable invisible tape, comprising the following steps: S1: Mix 70g of polyvinyl chloride resin SG-2, 30g of plasticizer, and 1g of heat stabilizer, plasticize at 150℃ for 10min, and calender into a transparent substrate with a thickness of 20μm. S2: The transparent substrate is laid flat in the ultrasonic reactor. 84g of anhydrous ethanol, 20g of 2-aminooxazole, and 5g of propylene oxide are added to the reactor. The liquid supply device at the bottom of the reactor is turned on, and 0.2g of boron trifluoride diethyl ether complex is added. The ultrasonic probe is inserted into the liquid material, the ultrasonic instrument is turned on, and the material is dripped onto the surface of the substrate by the top dripping device. The ultrasonic reaction is continued for 2.5 hours. After the reaction is completed, the ultrasonic instrument is turned off, the anhydrous ethanol is removed by vacuum distillation, the substrate is cooled to room temperature, and dried to obtain the modified transparent substrate. S3: Disperse 5g of nano-silver particles, 15g of chitosan derivative, and 1g of dispersant in 200g of deionized water, and sonicate for 20min to obtain an antibacterial dispersion; uniformly coat the antibacterial dispersion onto a modified transparent substrate, and dry to form an antibacterial layer with a thickness of 3μm; S4: Mix 70g of acrylate monomer, 8g of hydroxyethyl acrylate and 0.5g of initiator, react at 60℃ for 2h, add 1g of propylene glycol methyl ether acetate, stir evenly to obtain pressure-sensitive adhesive; S5: Apply pressure-sensitive adhesive to the other side of the substrate with the antibacterial layer, with a coating thickness of 15μm; composite the film coated with pressure-sensitive adhesive with a polyethylene terephthalate release film with a thickness of 25μm, cure at 100℃ for 10min, flatten by calendering rollers, cool to room temperature, and cut by cutting machine to obtain antibacterial writable invisible tape.

[0025] The plasticizer is a mixture of dioctyl phthalate and epoxidized soybean oil in a mass ratio of 2:1.

[0026] The heat stabilizer mentioned is calcium-zinc composite stabilizer JCZ-100.

[0027] The chitosan derivative is carboxymethyl chitosan.

[0028] The dispersant is sodium dodecylbenzenesulfonate or...

[0029] The drying temperature of S3 is 80℃ and the drying time is 5 minutes.

[0030] The acrylate monomer is a mixture of methyl methacrylate and butyl acrylate in a mass ratio of 1:3.

[0031] The initiator is ammonium persulfate.

[0032] The S5 coating method uses microgravure coating, with a calendering roller pressure of 0.3 MPa and a temperature of 40°C.

[0033] The vacuum degree of the S2 vacuum distillation is 0.06 MPa and the temperature is 40℃. Example

[0034] A method for preparing an antibacterial, writable invisible tape, comprising the following steps: S1: Mix 80g of polyvinyl chloride resin SG-2, 35g of plasticizer, and 2g of heat stabilizer, plasticize at 155℃ for 15min, and calender into a transparent substrate with a thickness of 25μm. S2: The transparent substrate is laid flat in the ultrasonic reactor. 102g of anhydrous ethanol, 23g of 2-aminooxazole, and 6g of propylene oxide are added to the reactor. The liquid supply device at the bottom of the reactor is turned on, and 0.3g of boron trifluoride diethyl ether complex is added. The ultrasonic probe is inserted into the liquid material, the ultrasonic instrument is turned on, and the material is dripped onto the surface of the substrate by the top dripping device. The ultrasonic reaction is continued for 3 hours. After the reaction is completed, the ultrasonic instrument is turned off, the anhydrous ethanol is removed by vacuum distillation, the substrate is cooled to room temperature, and dried to obtain the modified transparent substrate. S3: Disperse 6g of silver nanoparticles, 18g of chitosan derivative, and 2g of dispersant in 240g of deionized water, and sonicate for 25min to obtain an antibacterial dispersion; coat the antibacterial dispersion evenly on a modified transparent substrate, and dry to form an antibacterial layer with a thickness of 4μm; S4: Mix 80g of acrylate monomer, 10g of hydroxyethyl acrylate and 0.8g of initiator, react at 65℃ for 3h, add 2g of propylene glycol methyl ether acetate, stir evenly to obtain pressure-sensitive adhesive. S5: Apply pressure-sensitive adhesive to the other side of the substrate with the antibacterial layer, with a coating thickness of 20μm; composite the film coated with pressure-sensitive adhesive with a polyethylene terephthalate release film with a thickness of 35μm, cure at 105℃ for 11min, flatten by calendering rollers, cool to room temperature, and cut by a cutting machine to obtain antibacterial writable invisible tape.

[0035] The plasticizer is a mixture of dioctyl phthalate and epoxidized soybean oil in a mass ratio of 2.5:1.

[0036] The heat stabilizer mentioned is calcium-zinc composite stabilizer JCZ-100.

[0037] The chitosan derivative is carboxymethyl chitosan.

[0038] The dispersant is sodium dodecylbenzenesulfonate.

[0039] The drying temperature of S3 is 85℃ and the drying time is 6 minutes.

[0040] The acrylate monomer is a mixture of methyl methacrylate and butyl acrylate in a mass ratio of 1.5:3.

[0041] The initiator is ammonium persulfate.

[0042] The S5 coating method uses microgravure coating, with a calendering roller pressure of 0.4 MPa and a temperature of 45°C.

[0043] The vacuum degree of the S2 vacuum distillation is 0.07 MPa and the temperature is 40℃. Example

[0044] A method for preparing an antibacterial, writable invisible tape, comprising the following steps: S1: Mix 90g of polyvinyl chloride resin SG-2, 40g of plasticizer and 4g of heat stabilizer, plasticize at 165℃ for 15min, and calender into a transparent substrate with a thickness of 25μm. S2: The transparent substrate is laid flat in an ultrasonic reactor. 145g of anhydrous ethanol, 28g of 2-aminooxazole, and 7g of propylene oxide are added to the reactor. The permeation supply device at the bottom of the reactor is turned on, and 0.4g of boron trifluoride diethyl ether complex is added. The ultrasonic probe is inserted into the liquid material, the ultrasonic instrument is turned on, and the material is dripped onto the surface of the substrate by the top dripping device. The ultrasonic reaction is continued for 4 hours. After the reaction is completed, the ultrasonic instrument is turned off, the anhydrous ethanol is removed by vacuum distillation, the substrate is cooled to room temperature, and dried to obtain the modified transparent substrate. S3: Disperse 8g of silver nanoparticles, 23g of chitosan derivative, and 2g of dispersant in 280g of deionized water, and sonicate for 25min to obtain an antibacterial dispersion; uniformly coat the antibacterial dispersion onto a modified transparent substrate, and dry to form an antibacterial layer with a thickness of 4μm; S4: Mix 90g of acrylate monomer, 13g of hydroxyethyl acrylate and 1.3g of initiator, react at 75℃ for 3h, add 4g of propylene glycol methyl ether acetate, stir evenly to obtain pressure-sensitive adhesive; S5: Apply pressure-sensitive adhesive to the other side of the substrate with the antibacterial layer, with a coating thickness of 20μm; composite the film coated with pressure-sensitive adhesive with a polyethylene terephthalate release film with a thickness of 45μm, cure at 115℃ for 14min, flatten by calendering rollers, cool to room temperature, and cut by a cutting machine to obtain antibacterial writable invisible tape.

[0045] The plasticizer is a mixture of dioctyl phthalate and epoxidized soybean oil in a mass ratio of 2.5:1.

[0046] The heat stabilizer mentioned is calcium-zinc composite stabilizer JCZ-201.

[0047] The chitosan derivative is hydroxypropyl chitosan.

[0048] The dispersant mentioned is Tween-80.

[0049] The drying temperature of S3 is 95℃ and the drying time is 8 minutes.

[0050] The acrylate monomer is a mixture of methyl methacrylate and butyl acrylate in a mass ratio of 1.5:3.

[0051] The initiator is azobisisobutyronitrile.

[0052] The S5 coating method uses microgravure coating, with a calendering roller pressure of 0.4 MPa and a temperature of 45°C.

[0053] The vacuum degree of the S2 vacuum distillation is 0.07 MPa, and the temperature is 45℃. Example

[0054] A method for preparing an antibacterial, writable invisible tape, comprising the following steps: S1: Mix 100g of polyvinyl chloride resin SG-2, 45g of plasticizer, and 5g of heat stabilizer, plasticize at 170℃ for 20min, and calender into a transparent substrate with a thickness of 30μm. S2: The transparent substrate is laid flat in an ultrasonic reactor. 168g of anhydrous ethanol, 30g of 2-aminooxazole, and 8g of propylene oxide are added to the reactor. The liquid supply device at the bottom of the reactor is turned on, and 0.5g of boron trifluoride diethyl ether complex is added. The ultrasonic probe is inserted into the liquid material, the ultrasonic instrument is turned on, and the material is dripped onto the surface of the substrate by the top dripping device. The ultrasonic reaction is continued for 4.5 hours. After the reaction is completed, the ultrasonic instrument is turned off, the anhydrous ethanol is removed by vacuum distillation, the substrate is cooled to room temperature, and dried to obtain the modified transparent substrate. S3: Disperse 10g of nano-silver particles, 25g of chitosan derivative, and 3g of dispersant in 300g of deionized water, and sonicate for 30min to obtain an antibacterial dispersion; coat the antibacterial dispersion evenly on a modified transparent substrate, and dry to form an antibacterial layer with a thickness of 5μm; S4: Mix 100g of acrylate monomer, 15g of hydroxyethyl acrylate and 1.5g of initiator, react at 80℃ for 4h, add 5g of propylene glycol methyl ether acetate, stir evenly to obtain pressure-sensitive adhesive. S5: Apply pressure-sensitive adhesive to the other side of the substrate with the antibacterial layer, with a coating thickness of 25μm; composite the film coated with pressure-sensitive adhesive with a polyethylene terephthalate release film with a thickness of 50μm, cure at 120℃ for 15min, flatten by calendering rollers, cool to room temperature, and cut by a cutting machine to obtain antibacterial writable invisible tape.

[0055] The plasticizer is a mixture of dioctyl phthalate and epoxidized soybean oil in a mass ratio of 3:1.

[0056] The heat stabilizer mentioned is calcium-zinc composite stabilizer JCZ-201.

[0057] The chitosan derivative is hydroxypropyl chitosan.

[0058] The dispersant mentioned is Tween-80.

[0059] The drying temperature of S3 is 100℃ and the drying time is 10 minutes.

[0060] The acrylate monomer is a mixture of methyl methacrylate and butyl acrylate in a mass ratio of 2:3.

[0061] The initiator is azobisisobutyronitrile.

[0062] The S5 coating method uses microgravure coating, with a calendering roller pressure of 0.5 MPa and a temperature of 50°C.

[0063] The vacuum degree of the S2 vacuum distillation is 0.08 MPa and the temperature is 45℃.

[0064] Comparative Example 1 A method for preparing an antibacterial, writable invisible tape, comprising the following steps: S1: Mix 70g of polyvinyl chloride resin SG-2, 30g of plasticizer, and 1g of heat stabilizer, plasticize at 150℃ for 10min, and calender into a transparent substrate with a thickness of 20μm. S2: Disperse 5g of nano-silver particles, 15g of chitosan derivative, and 1g of dispersant in 200g of deionized water, and sonicate for 20min to obtain an antibacterial dispersion; coat the antibacterial dispersion evenly on a transparent substrate, and dry to form an antibacterial layer with a thickness of 3μm; S3: Mix 70g of acrylate monomer, 8g of hydroxyethyl acrylate and 0.5g of initiator, react at 60℃ for 2h, add 1g of propylene glycol methyl ether acetate, stir evenly to obtain pressure-sensitive adhesive. S4: Apply pressure-sensitive adhesive to the other side of the substrate with the antibacterial layer, with a coating thickness of 15μm; composite the film coated with pressure-sensitive adhesive with a polyethylene terephthalate release film with a thickness of 25μm, cure at 100℃ for 10min, flatten by calendering rollers, cool to room temperature, and cut by a cutting machine to obtain antibacterial writable invisible tape.

[0065] The plasticizer is a mixture of dioctyl phthalate and epoxidized soybean oil in a mass ratio of 2:1.

[0066] The heat stabilizer mentioned is calcium-zinc composite stabilizer JCZ-100.

[0067] The chitosan derivative is carboxymethyl chitosan.

[0068] The dispersant is sodium dodecylbenzenesulfonate or...

[0069] The drying temperature of S2 is 80℃ and the drying time is 5 minutes.

[0070] The acrylate monomer is a mixture of methyl methacrylate and butyl acrylate in a mass ratio of 1:3.

[0071] The initiator is ammonium persulfate.

[0072] The S4 coating method uses microgravure coating, with a calendering roller pressure of 0.3 MPa and a temperature of 40°C.

[0073] Comparative Example 2 A method for preparing an antibacterial, writable invisible tape, comprising the following steps: S1: Mix 70g of polyvinyl chloride resin SG-2, 30g of plasticizer, and 1g of heat stabilizer, plasticize at 150℃ for 10min, and calender into a transparent substrate with a thickness of 20μm. S2: The transparent substrate is laid flat in the ultrasonic reactor. 84g of anhydrous ethanol and 5g of propylene oxide are added to the reactor. The liquid supply device at the bottom of the reactor is turned on, and 0.2g of boron trifluoride diethyl ether complex is added. The ultrasonic probe is inserted into the liquid material, the ultrasonic instrument is turned on, and the material is dripped onto the surface of the substrate by the top dripping device. The ultrasonic reaction is continued for 2.5 hours. After the reaction is completed, the ultrasonic instrument is turned off, the anhydrous ethanol is removed by vacuum distillation, the substrate is cooled to room temperature, and dried to obtain the modified transparent substrate. S3: Disperse 5g of nano-silver particles, 15g of chitosan derivative, and 1g of dispersant in 200g of deionized water, and sonicate for 20min to obtain an antibacterial dispersion; uniformly coat the antibacterial dispersion onto a modified transparent substrate, and dry to form an antibacterial layer with a thickness of 3μm; S4: Mix 70g of acrylate monomer, 8g of hydroxyethyl acrylate and 0.5g of initiator, react at 60℃ for 2h, add 1g of propylene glycol methyl ether acetate, stir evenly to obtain pressure-sensitive adhesive; S5: Apply pressure-sensitive adhesive to the other side of the substrate with the antibacterial layer, with a coating thickness of 15μm; composite the film coated with pressure-sensitive adhesive with a polyethylene terephthalate release film with a thickness of 25μm, cure at 100℃ for 10min, flatten by calendering rollers, cool to room temperature, and cut by cutting machine to obtain antibacterial writable invisible tape.

[0074] The plasticizer is a mixture of dioctyl phthalate and epoxidized soybean oil in a mass ratio of 2:1.

[0075] The heat stabilizer mentioned is calcium-zinc composite stabilizer JCZ-100.

[0076] The chitosan derivative is carboxymethyl chitosan.

[0077] The dispersant is sodium dodecylbenzenesulfonate or...

[0078] The drying temperature of S3 is 80℃ and the drying time is 5 minutes.

[0079] The acrylate monomer is a mixture of methyl methacrylate and butyl acrylate in a mass ratio of 1:3.

[0080] The initiator is ammonium persulfate.

[0081] The S5 coating method uses microgravure coating, with a calendering roller pressure of 0.3 MPa and a temperature of 40°C.

[0082] The vacuum degree of the S2 vacuum distillation is 0.06 MPa and the temperature is 40℃.

[0083] Comparative Example 3 A method for preparing an antibacterial, writable invisible tape, comprising the following steps: S1: Mix 70g of polyvinyl chloride resin SG-2, 30g of plasticizer, and 1g of heat stabilizer, plasticize at 150℃ for 10min, and calender into a transparent substrate with a thickness of 20μm. S2: The transparent substrate is laid flat in the ultrasonic reactor. 84g of anhydrous ethanol and 20g of 2-aminooxazole are added to the reactor. The liquid supply device at the bottom of the reactor is turned on, and 0.2g of boron trifluoride diethyl ether complex is added. The ultrasonic probe is inserted into the liquid material, the ultrasonic instrument is turned on, and the material is dripped onto the surface of the substrate by the top dripping device. The ultrasonic reaction is continued for 2.5 hours. After the reaction is completed, the ultrasonic instrument is turned off, the anhydrous ethanol is removed by vacuum distillation, the substrate is cooled to room temperature, and dried to obtain the modified transparent substrate. S3: Disperse 5g of nano-silver particles, 15g of chitosan derivative, and 1g of dispersant in 200g of deionized water, and sonicate for 20min to obtain an antibacterial dispersion; uniformly coat the antibacterial dispersion onto a modified transparent substrate, and dry to form an antibacterial layer with a thickness of 3μm; S4: Mix 70g of acrylate monomer, 8g of hydroxyethyl acrylate and 0.5g of initiator, react at 60℃ for 2h, add 1g of propylene glycol methyl ether acetate, stir evenly to obtain pressure-sensitive adhesive; S5: Apply pressure-sensitive adhesive to the other side of the substrate with the antibacterial layer, with a coating thickness of 15μm; composite the film coated with pressure-sensitive adhesive with a polyethylene terephthalate release film with a thickness of 25μm, cure at 100℃ for 10min, flatten by calendering rollers, cool to room temperature, and cut by cutting machine to obtain antibacterial writable invisible tape.

[0084] The plasticizer is a mixture of dioctyl phthalate and epoxidized soybean oil in a mass ratio of 2:1.

[0085] The heat stabilizer mentioned is calcium-zinc composite stabilizer JCZ-100.

[0086] The chitosan derivative is carboxymethyl chitosan.

[0087] The dispersant is sodium dodecylbenzenesulfonate or...

[0088] The drying temperature of S3 is 80℃ and the drying time is 5 minutes.

[0089] The acrylate monomer is a mixture of methyl methacrylate and butyl acrylate in a mass ratio of 1:3.

[0090] The initiator is ammonium persulfate.

[0091] The S5 coating method uses microgravure coating, with a calendering roller pressure of 0.3 MPa and a temperature of 40°C.

[0092] The vacuum degree of the S2 vacuum distillation is 0.06 MPa and the temperature is 40℃.

[0093] Light transmittance (%) Bond strength (N / 25mm) Antibacterial rate of Escherichia coli (%) Antibacterial rate against Staphylococcus aureus (%) Handwriting clarity score (points) Example 1 94.3 2.2 99.83 99.87 8.8 Example 2 94.5 2.3 99.86 99.89 9.0 Example 3 95.0 2.5 99.91 99.93 9.3 Example 4 95.2 2.6 99.93 99.96 9.5 Comparative Example 1 81.7 1.3 75.32 76.84 4.6 Comparative Example 2 89.8 1.6 94.11 94.75 7.1 Comparative Example 3 90.6 1.8 94.96 95.41 7.5 The data clearly show that the antibacterial writable invisible tapes prepared in Examples 1-4 are significantly superior to those in Comparative Examples 1-3 in terms of light transmittance, adhesive strength, antibacterial rate, and writing clarity. The core reason for this difference lies in the synergistic effect of the various auxiliary compounds and the necessity of the key modification steps, which can be analyzed from the following dimensions: Substrate modification system (2-aminooxazole, propylene oxide, boron trifluoride diethyl ether complex): 2-aminooxazole and propylene oxide undergo an addition reaction under the catalysis of boron trifluoride diethyl ether complex (Lewis acid catalyst), and the resulting functional groups can stably bind with free radicals on the PVC substrate surface—this step is fundamental to ensuring various performance characteristics. Comparative Example 1 did not undergo this modification, resulting in unstable adhesion between the antibacterial layer and the substrate (significantly reduced antibacterial rate), lack of a suitable microstructure for writing on the substrate surface (low writing score), weak adhesion between the substrate and pressure-sensitive adhesive (low bonding strength), and no optimization of the substrate structure (reduced light transmittance). Comparative Example 2 lacked 2-aminooxazole, and Comparative Example 3 lacked propylene oxide, both failing to form a complete functional binding system. Therefore, their antibacterial, adhesive, writing, and light transmittance properties were all weaker than those of the examples, confirming the crucial supporting role of the synergistic modification of the three components in performance.

[0094] Substrate processing aids (plasticizer, heat stabilizer): The plasticizer is a compound of dioctyl phthalate and propylene oxide in a ratio of 2-3:1, which ensures the flexibility of the PVC substrate during plasticization at 150-170℃ (meeting the calendering requirements of 20-30μm thin substrates) and avoids the decrease in light transmittance of the substrate caused by a single plasticizer; the heat stabilizer is a calcium-zinc composite stabilizer (JCZ-100 / JCZ-201), which can prevent PVC from degrading and yellowing during high-temperature plasticization and ensure the transparency of the substrate. This is also an important reason why the light transmittance of the example is maintained above 94%.

[0095] Antibacterial dispersion aids (chitosan derivatives, dispersants): Nano-silver particles and carboxymethyl chitosan / hydroxypropyl chitosan (chitosan derivatives) form a synergistic antibacterial system—nano-silver acts directly on pathogenic bacteria, while chitosan derivatives enhance antibacterial durability through their own structure, and simultaneously improve the dispersibility of nano-silver in water; sodium dodecylbenzenesulfonate / Tween-80 (dispersant) further prevents nano-silver agglomeration, ensuring that the antibacterial components are uniformly coated on the substrate surface, without affecting light transmittance due to agglomeration (stable light transmittance in the examples), and achieving comprehensive antibacterial effect (antibacterial rate of nearly 99.8% or more), while in Comparative Example 1, because the substrate was not modified, the antibacterial components were unevenly dispersed, so the antibacterial rate was only about 75%.

[0096] Additives to the pressure-sensitive adhesive system (acrylate monomers, hydroxyethyl acrylate): The acrylate monomers are a blend of methyl methacrylate and butyl acrylate in a ratio of 1-2:3. Combined with the introduction of hydroxyethyl acrylate, the adhesive strength of the pressure-sensitive adhesive is ensured by adjusting the ratio of rigid and flexible monomers (adhesive strength of 2.2-2.6 N / 25 mm in the example), and the hydroxyl groups of hydroxyethyl acrylate adjust the surface properties of the adhesive layer, helping to improve writing adaptability. Propylene glycol methyl ether acetate optimizes the coating flow of the pressure-sensitive adhesive, ensuring a uniform adhesive layer (avoiding the impact of uneven coating on light transmission and adhesion). This is also an important reason why the adhesive strength and writing performance of the example are better than those of the comparative example.

[0097] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A method for preparing an antibacterial, writable invisible tape, comprising the following steps, in parts by weight: S1: Mix 70-100 parts of polyvinyl chloride resin, 30-45 parts of plasticizer, and 1-5 parts of heat stabilizer, plasticize at 150-170℃ for 10-20 minutes, and calender into a transparent substrate with a thickness of 20-30μm. S2: The transparent substrate is laid flat in an ultrasonic reactor. 84-168 parts of anhydrous ethanol, 20-30 parts of 2-aminooxazole, and 5-8 parts of propylene oxide are added to the reactor. The permeation supply device at the bottom of the reactor is turned on, and 0.2-0.5 parts of boron trifluoride diethyl ether complex are added. The ultrasonic probe is inserted into the liquid material, the ultrasonic instrument is turned on, and the material is dripped onto the surface of the substrate using the top dripping device. The ultrasonic reaction is continued for 2.5-4.5 hours. After the reaction is completed, the ultrasonic instrument is turned off, the anhydrous ethanol is removed by vacuum distillation, the substrate is cooled to room temperature, and dried to obtain the modified transparent substrate. S3: Disperse 5-10 parts of nano-silver particles, 15-25 parts of chitosan derivative, and 1-3 parts of dispersant in 200-300 parts of deionized water, and sonicate for 20-30 minutes to obtain an antibacterial dispersion; uniformly coat the antibacterial dispersion onto a modified transparent substrate, and dry to form an antibacterial layer with a thickness of 3-5 μm; S4: Mix 70-100 parts of acrylate monomer, 8-15 parts of hydroxyethyl acrylate, and 0.5-1.5 parts of initiator, and react at 60-80℃ for 2-4 hours. Add 1-5 parts of propylene glycol methyl ether acetate, stir evenly, and obtain pressure-sensitive adhesive. S5: Apply pressure-sensitive adhesive to the other side of the substrate with the antibacterial layer, with a coating thickness of 15-25μm; laminate the film coated with pressure-sensitive adhesive with a polyethylene terephthalate release film with a thickness of 25-50μm, cure at 100-120℃ for 10-15min, flatten by calendering rollers, cool to room temperature, and cut by a cutting machine to obtain antibacterial writable invisible tape.

2. The method for preparing an antibacterial writable invisible tape according to claim 1, characterized in that: The plasticizer is a mixture of dioctyl phthalate and epoxidized soybean oil in a mass ratio of 2-3:

1.

3. The method for preparing an antibacterial writable invisible tape according to claim 1, characterized in that: The heat stabilizer is a calcium-zinc composite stabilizer JCZ-100 or JCZ-201.

4. The method for preparing an antibacterial writable invisible tape according to claim 1, characterized in that: The chitosan derivative is carboxymethyl chitosan or hydroxypropyl chitosan.

5. The method for preparing an antibacterial writable invisible tape according to claim 1, characterized in that: The dispersant is sodium dodecylbenzenesulfonate or Tween-80.

6. The method for preparing an antibacterial writable invisible tape according to claim 1, characterized in that: The drying temperature of S3 is 80-100℃, and the drying time is 5-10 minutes.

7. The method for preparing an antibacterial writable invisible tape according to claim 1, characterized in that: The acrylate monomer is a mixture of methyl methacrylate and butyl acrylate in a mass ratio of 1-2:

3.

8. The method for preparing an antibacterial writable invisible tape according to claim 1, characterized in that: The initiator is ammonium persulfate or azobisisobutyronitrile.

9. The method for preparing an antibacterial writable invisible tape according to claim 1, characterized in that: The S5 coating method uses microgravure coating, with a calendering roller pressure of 0.3-0.5 MPa and a temperature of 40-50℃.

10. The method for preparing an antibacterial writable invisible tape according to claim 1, characterized in that: The vacuum degree of the S2 vacuum distillation is 0.06-0.08 MPa, and the temperature is 40-45℃.