Preparation method of release film for adhesive tape

Abstract

The invention discloses a preparation method of a release film for an adhesive tape. Comprising the following steps: step 1, uniformly mixing vinyl silicone resin, a modified acrylic copolymer, vinyl silicone oil, a photoinitiator, a defoaming agent, a flatting agent, an antioxidant and a solvent, and standing for defoaming to obtain a release agent; and 2, carrying out corona treatment on one side of the polyethylene glycol terephthalate base film, then coating the surface subjected to corona treatment with a release agent, and carrying out curing and cooling processes to obtain the release film. The preparation method of the release film for the adhesive tape, provided by the invention, has the beneficial effects that the performance of the release film is remarkably improved by optimizing the formula and the preparation process of the release agent.

Description

Technical Field

[0001] This invention belongs to the field of release film technology, specifically, it relates to a method for preparing a release film for adhesive tape. Background Technology

[0002] In the field of preparing release film for adhesive tapes, traditional techniques typically use vinyl silicone resin as the main component of the release agent, which is coated onto the surface of a polyester base film to form a release layer.

[0003] However, existing technologies have several significant drawbacks: First, the compatibility between the vinyl silicone resin in traditional release films and the base film is poor, leading to insufficient coating uniformity and affecting the stability of the release force, especially prone to fluctuations or failure at high temperatures. Second, conventional release films typically rely on small-molecule flame-retardant additives to achieve flame-retardant properties, but these additives are prone to migration and precipitation, causing the flame-retardant effect to decay over time and contaminating the adhesive layer, resulting in decreased tape adhesion. Furthermore, the migration problem of small-molecule additives such as vinyl silicone oil in existing technologies has not been effectively solved, further exacerbating the instability of release film performance. Although some studies have attempted to improve performance by adding compatibilizers or modifying resins, it is often difficult to balance release force, flame retardancy, and long-term stability. For example, simply increasing acrylic resin can improve adhesion to the base film, but may reduce compatibility with vinyl silicone resin; and when flame-retardant components are introduced, migration problems cannot be avoided if they are not fixed by chemical bonding.

[0004] Therefore, in order to solve the above problems, the present invention provides a method for preparing a release film for adhesive tape. Summary of the Invention

[0005] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for preparing release film for adhesive tape.

[0006] The objective of this invention can be achieved through the following technical solutions: A method for preparing a release film for adhesive tape includes the following steps: Step 1: Mix vinyl silicone resin, modified acrylic copolymer, vinyl silicone oil, photoinitiator, defoamer, leveling agent, antioxidant, and solvent evenly, let stand to defoam, and obtain release agent; Step 2: Corona treatment is performed on one side of the polyethylene terephthalate-based film. Then, release agent is coated on the corona-treated surface. After curing and cooling, release film is obtained.

[0007] More preferably, the release agent comprises the following components: by weight, 30-40 parts vinyl silicone resin, 10-20 parts modified acrylic copolymer, 4-5 parts vinyl silicone oil, 1-2 parts photoinitiator, 0.5-0.8 parts defoamer, 0.5-0.8 parts leveling agent, 0.5-1 part antioxidant, and 70-80 parts solvent.

[0008] More optimally, the modified acrylic copolymer is characterized by the following preparation process: A1: Mix hydroxyl silicone resin, tetraisopropoxide titanium, stannous octoate and toluene, raise the temperature to 80-90℃, add hydroxyethyl methacrylate, continue to raise the temperature to 110-120℃, stir and react for 1-2 hours, dry and grind to obtain acrylate siloxane monomer. A2: (1) Mix acrylate siloxane monomer, ethyl acrylate, acrylamide and functional monomer evenly to obtain monomer mixture; (2) Under a protective atmosphere, mix 10wt% of monomer mixture with xylene-n-butanol mixed solvent and dodecyl mercaptan evenly, add part of azobisisobutyronitrile, raise the temperature to 80-90℃, react for 10-15min, then add the remaining monomer mixture and azobisisobutyronitrile to the reaction system in 9 portions, with an interval of 15min each time. After the addition is completed, keep the reaction at the temperature for 2-3h, cool down and discharge to obtain modified acrylic copolymer.

[0009] In a more optimized manner, the raw materials for preparing the acrylate siloxane monomer include the following components: by weight, 10-12 parts hydroxyl silicone resin, 0.1-0.2 parts tetraisopropoxide titanium, 0.05-0.08 parts stannous octoate, 40-50 parts toluene, and 0.7-1 parts hydroxyethyl methacrylate.

[0010] In a more optimized manner, the raw materials for preparing the modified acrylic copolymer include the following components: by weight, 15-20 parts acrylate siloxane monomer, 40-50 parts ethyl acrylate, 15-20 parts acrylamide, 10-12 parts functional monomer, 200-300 parts xylene-n-butanol mixed solvent, 0.5-1 part dodecyl mercaptan, and 1-2 parts azobisisobutyronitrile.

[0011] In a more optimized manner, the preparation process of the functional monomer is as follows: S1: Mix bromopentafluorobenzene, magnesium shavings, and diethyl ether, raise the temperature to 35-40℃, reflux for 1-2 hours, cool to room temperature, slowly add diphenyl chlorophosphate, stir for 20-30 minutes, then raise the temperature to 70-80℃, reflux for 4-5 hours, cool to room temperature, stir overnight, and then perform post-processing to obtain intermediate A. S2: Mix intermediate A with acetone, add sodium azide, react at 40-50℃ for 1-2 hours, remove acetone by rotary evaporation, dissolve the residue in chloroform, wash with water, dry and concentrate, and after purification, obtain intermediate B. S3: Propylene alcohol acrylate was added to N,N-dimethylformamide, and under a protective atmosphere, intermediate B, pentamethyldiethylenetriamine and cuprous bromide were added sequentially. The mixture was stirred overnight at room temperature and then post-treated to obtain the functional monomer.

[0012] In the process, bromopentafluorobenzene reacts with magnesium to form a Grignard reagent, which then undergoes a nucleophilic substitution reaction with diphenyl chlorophosphate to generate intermediate A.

[0013] In a more optimized manner, the raw materials for preparing intermediate A include the following components: by weight, 23-25 ​​parts of bromopentafluorobenzene, 2-3 parts of magnesium shavings, 80-100 parts of diethyl ether, and 25-28 parts of diphenyl chlorophosphate.

[0014] In the process, intermediate A is subjected to sodium azide, and the azide anion replaces its leaving group, resulting in intermediate B containing an azide group.

[0015] In a more optimized manner, the raw materials for preparing intermediate B include the following components: by weight, 15-18 parts intermediate A, 60-80 parts acetone, and 2-3 parts sodium azide.

[0016] In the scheme, under the catalysis of copper and the action of ligands, the azide group of intermediate B undergoes a cycloaddition reaction with the alkynyl group of propynyl alcohol acrylate to generate a functional monomer.

[0017] In a more optimized manner, the raw materials for preparing the functional monomer include the following components: by weight, 12-13 parts propynyl acrylate, 80-100 parts N,N-dimethylformamide, 53-54 parts intermediate B, 3-4 parts pentamethyldiethylenetriamine, and 1-2 parts cuprous bromide.

[0018] The specific synthesis process of the functional monomers in the scheme is as follows: The beneficial effects of this invention are: Firstly, the modified acrylic copolymer synthesized in this scheme contains ethyl acrylate and acrylamide monomers, which can provide strong anchoring force with the strongly polar groups generated on the surface of the corona-treated base film. The acrylate siloxane monomers are highly similar to the vinyl silicone resin in the release agent, ensuring good compatibility with the silicone resin. Therefore, the modified acrylic copolymer acts as a highly efficient molecular bridge, significantly reducing the interfacial tension between the vinyl silicone resin phase and the acrylic components / base film, promoting uniform dispersion of each component in the coating solution and cured film, and ensuring excellent smoothness, transparency, and uniformity of the coating.

[0019] Secondly, in this scheme, the synthesized functional monomers permanently fix flame-retardant elements such as P, F, and N onto the polymer chain through chemical bonding, overcoming the shortcomings of small-molecule flame retardants such as easy migration, precipitation, and failure, and providing long-lasting, stable, and environmentally friendly halogen-free flame-retardant properties. The non-migration characteristic also avoids contamination of the adhesive tape by the flame-retardant components, reducing adhesive attenuation caused by the intrusion of foreign substances. Furthermore, the introduced rigid heterocyclic structure (triazole ring) further improves the high-temperature dimensional stability and mechanical strength retention of the release film. Detailed Implementation

[0020] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] It should be noted that in the following examples and comparative examples, the brand of hydroxyl silicone resin is Dow RSN-6018, purchased from Shenzhen Longdi Chemical Co., Ltd.

[0022] Example 1: A method for preparing a release film for adhesive tape, comprising the following steps: Step 1: Mix 30 parts vinyl silicone resin, 10 parts modified acrylic copolymer, 4 parts vinyl silicone oil, 1 part photoinitiator (benzophenone), 0.5 parts defoamer (BYK-066N), 0.5 parts leveling agent (BYK-306), 0.5 parts antioxidant (antioxidant 264), and 70 parts solvent (xylene / n-butanol = 7:3) evenly, let stand to defoam, and obtain the release agent; Step 2: Corona treatment is performed on one side of the polyethylene terephthalate-based film, and then a release agent is coated on the corona-treated surface. After curing and cooling, a release film is obtained. The preparation process of the modified acrylic copolymer is as follows: A1: Mix 10 parts of hydroxyl silicone resin, 0.1 parts of tetraisopropoxide titanium, 0.05 parts of stannous octoate and 40 parts of toluene, raise the temperature to 80°C, add 0.7 parts of hydroxyethyl methacrylate, continue to raise the temperature to 110°C, stir and react for 1 hour, dry and grind to obtain acrylate siloxane monomer. A2: (1) Mix 15 parts of acrylate siloxane monomer, 40 parts of ethyl acrylate, 15 parts of acrylamide, and 10 parts of functional monomer evenly to obtain a monomer mixture; (2) Under a protective atmosphere, mix 10 wt% of the monomer mixture with 200 parts of xylene-n-butanol mixed solvent (7:3) and 0.5 parts of dodecyl mercaptan evenly, add a portion of azobisisobutyronitrile, raise the temperature to 80°C, react for 10 min, then add the remaining monomer mixture and azobisisobutyronitrile to the reaction system in 9 portions, with an interval of 15 min between each addition. After the addition is complete, keep the reaction at the temperature for 2 h, cool down and discharge to obtain the modified acrylic copolymer (a total of 1 part of azobisisobutyronitrile was added). The preparation process of the functional monomer is as follows: S1: Mix 23 parts of bromopentafluorobenzene, 2 parts of magnesium shavings and 80 parts of diethyl ether, raise the temperature to 35°C, reflux for 1 hour, cool to room temperature, slowly add 25 parts of diphenyl chlorophosphate, stir for 20 minutes, then raise the temperature to 70°C, reflux for 4 hours, cool to room temperature and stir overnight, and then perform post-processing to obtain intermediate A. S2: Mix 15 parts of intermediate A with 60 parts of acetone, add 2 parts of sodium azide, react at 40°C for 1 hour, remove acetone by rotary evaporation, dissolve the residue in chloroform, wash with water, dry and concentrate, and after purification, obtain intermediate B. S3: Add 12 parts of propynyl alcohol acrylate to 80 parts of N,N-dimethylformamide. Under a protective atmosphere, add 53 parts of intermediate B, 3 parts of pentamethyldiethylenetriamine and 1 part of cuprous bromide in sequence. Stir overnight at room temperature and then perform post-treatment to obtain the functional monomer.

[0023] Example 2: A method for preparing a release film for adhesive tape, comprising the following steps: Step 1: Mix 40 parts vinyl silicone resin, 20 parts modified acrylic copolymer, 5 parts vinyl silicone oil, 2 parts photoinitiator (benzophenone), 0.8 parts defoamer (BYK-066N), 0.8 parts leveling agent (BYK-306), 1 part antioxidant (antioxidant 264), and 80 parts solvent (xylene / n-butanol = 7:3) evenly, let stand to defoam, and obtain the release agent; Step 2: Corona treatment is performed on one side of the polyethylene terephthalate-based film, and then a release agent is coated on the corona-treated surface. After curing and cooling, a release film is obtained. The preparation process of the modified acrylic copolymer is as follows: A1: Mix 12 parts of hydroxyl silicone resin, 0.2 parts of tetraisopropoxide titanium, 0.08 parts of stannous octoate and 50 parts of toluene, raise the temperature to 90°C, add 1 part of hydroxyethyl methacrylate, continue to raise the temperature to 120°C, stir and react for 2 hours, dry and grind to obtain acrylate siloxane monomer. A2: (1) Mix 20 parts of acrylate siloxane monomer, 50 parts of ethyl acrylate, 20 parts of acrylamide, and 12 parts of functional monomer evenly to obtain a monomer mixture; (2) Under a protective atmosphere, mix 10 wt% of the monomer mixture with 300 parts of xylene-n-butanol mixed solvent (7:3) and 1 part of dodecyl mercaptan evenly, add some azobisisobutyronitrile, raise the temperature to 90°C, react for 15 min, then add the remaining monomer mixture and azobisisobutyronitrile to the reaction system in 9 portions, with an interval of 15 min each time. After the addition is completed, keep the reaction at the temperature for 3 h, cool down and discharge the material to obtain the modified acrylic copolymer (a total of 2 parts of azobisisobutyronitrile were added). The preparation process of the functional monomer is as follows: S1: Mix 25 parts of bromopentafluorobenzene, 3 parts of magnesium shavings and 100 parts of diethyl ether, raise the temperature to 40°C, reflux for 2 hours, cool to room temperature, slowly add 28 parts of diphenyl chlorophosphate, stir for 30 minutes, then raise the temperature to 80°C, reflux for 5 hours, cool to room temperature and stir overnight, and then perform post-processing to obtain intermediate A. S2: Mix 18 parts of intermediate A with 80 parts of acetone, add 3 parts of sodium azide, react at 50°C for 2 hours, remove acetone by rotary evaporation, dissolve the residue in chloroform, wash with water, dry and concentrate, and after purification, obtain intermediate B. S3: Add 13 parts of propynyl alcohol acrylate to 100 parts of N,N-dimethylformamide. Under a protective atmosphere, add 54 parts of intermediate B, 4 parts of pentamethyldiethylenetriamine and 2 parts of cuprous bromide in sequence. Stir overnight at room temperature and then perform post-treatment to obtain the functional monomer.

[0024] Example 3: A method for preparing a release film for adhesive tape, comprising the following steps: Step 1: Mix 35 parts vinyl silicone resin, 15 parts modified acrylic copolymer, 4.5 parts vinyl silicone oil, 1.5 parts photoinitiator (benzophenone), 0.65 parts defoamer (BYK-066N), 0.65 parts leveling agent (BYK-306), 0.75 parts antioxidant (antioxidant 264), and 75 parts solvent (xylene / n-butanol = 7:3) evenly, let stand to defoam, and obtain the release agent; Step 2: Corona treatment is performed on one side of the polyethylene terephthalate-based film, and then a release agent is coated on the corona-treated surface. After curing and cooling, a release film is obtained. The preparation process of the modified acrylic copolymer is as follows: A1: Mix 11 parts of hydroxyl silicone resin, 0.15 parts of tetraisopropoxide titanium, 0.065 parts of stannous octoate and 45 parts of toluene, raise the temperature to 85°C, add 0.85 parts of hydroxyethyl methacrylate, continue to raise the temperature to 115°C, stir and react for 1.5 h, dry and grind to obtain acrylate siloxane monomer. A2: (1) Mix 17.5 parts of acrylate siloxane monomer, 45 parts of ethyl acrylate, 17.5 parts of acrylamide, and 11 parts of functional monomer evenly to obtain a monomer mixture; (2) Under a protective atmosphere, mix 10 wt% of the monomer mixture with 250 parts of xylene-n-butanol mixed solvent (7:3) and 0.75 parts of dodecyl mercaptan evenly, add a portion of azobisisobutyronitrile, raise the temperature to 85°C, react for 12.5 min, then add the remaining monomer mixture and azobisisobutyronitrile to the reaction system in 9 portions, with an interval of 15 min each time. After the addition is complete, keep the reaction at the temperature for 2.5 h, cool down and discharge to obtain the modified acrylic copolymer (a total of 1.5 parts of azobisisobutyronitrile were added). The preparation process of the functional monomer is as follows: S1: Mix 24 parts of bromopentafluorobenzene, 2.5 parts of magnesium shavings, and 90 parts of diethyl ether. Raise the temperature to 38°C and reflux for 1.5 h. After cooling to room temperature, slowly add 26.5 parts of diphenyl chlorophosphate and stir for 25 min. Then raise the temperature to 75°C and reflux for 4.5 h. After cooling to room temperature, stir overnight and then perform post-processing to obtain intermediate A. S2: Mix 16.5 parts of intermediate A with 70 parts of acetone, add 2.5 parts of sodium azide, react at 45°C for 1.5 h, remove acetone by rotary evaporation, dissolve the residue in chloroform, wash with water, dry and concentrate, and purify to obtain intermediate B. S3: 12.5 parts of propynyl acrylate were added to 90 parts of N,N-dimethylformamide. Under a protective atmosphere, 53.5 parts of intermediate B, 3.5 parts of pentamethyldiethylenetriamine and 1.5 parts of cuprous bromide were added sequentially. The mixture was stirred overnight at room temperature and then post-treated to obtain the functional monomer.

[0025] Comparative Example 1: In the preparation process of the modified acrylic copolymer, no functional monomers were introduced, as follows: Step 1: Mix 35 parts vinyl silicone resin, 15 parts modified acrylic copolymer, 4.5 parts vinyl silicone oil, 1.5 parts photoinitiator (benzophenone), 0.65 parts defoamer (BYK-066N), 0.65 parts leveling agent (BYK-306), 0.75 parts antioxidant (antioxidant 264), and 75 parts solvent (xylene / n-butanol = 7:3) evenly, let stand to defoam, and obtain the release agent; Step 2: Corona treatment is performed on one side of the polyethylene terephthalate-based film, and then a release agent is coated on the corona-treated surface. After curing and cooling, a release film is obtained. The preparation process of the modified acrylic copolymer is as follows: A1: Mix 11 parts of hydroxyl silicone resin, 0.15 parts of tetraisopropoxide titanium, 0.065 parts of stannous octoate and 45 parts of toluene, raise the temperature to 85°C, add 0.85 parts of hydroxyethyl methacrylate, continue to raise the temperature to 115°C, stir and react for 1.5 h, dry and grind to obtain acrylate siloxane monomer. A2: (1) Mix 17.5 parts of acrylate siloxane monomer, 45 parts of ethyl acrylate and 17.5 parts of acrylamide evenly to obtain a monomer mixture; (2) Under a protective atmosphere, mix 10 wt% of the monomer mixture with 250 parts of xylene-n-butanol mixed solvent (7:3) and 0.75 parts of dodecyl mercaptan evenly, add some azobisisobutyronitrile, raise the temperature to 85°C, react for 12.5 min, then add the remaining monomer mixture and azobisisobutyronitrile to the reaction system in 9 portions, with an interval of 15 min each time. After the addition is completed, keep the reaction at the temperature for 2.5 h, cool down and discharge to obtain the modified acrylic copolymer (a total of 1.5 parts of azobisisobutyronitrile were added).

[0026] Comparative Example 2: In the preparation of the modified acrylic copolymer, no acrylate siloxane monomers were introduced, as follows: Step 1: Mix 35 parts vinyl silicone resin, 15 parts modified acrylic copolymer, 4.5 parts vinyl silicone oil, 1.5 parts photoinitiator (benzophenone), 0.65 parts defoamer (BYK-066N), 0.65 parts leveling agent (BYK-306), 0.75 parts antioxidant (antioxidant 264), and 75 parts solvent (xylene / n-butanol = 7:3) evenly, let stand to defoam, and obtain the release agent; Step 2: Corona treatment is performed on one side of the polyethylene terephthalate-based film, and then a release agent is coated on the corona-treated surface. After curing and cooling, a release film is obtained. The preparation process of the modified acrylic copolymer is as follows: A1: (1) Mix 45 parts of ethyl acrylate, 17.5 parts of acrylamide, and 11 parts of functional monomers evenly to obtain a monomer mixture; (2) Under a protective atmosphere, mix 10 wt% of the monomer mixture with 250 parts of xylene-n-butanol mixed solvent (7:3) and 0.75 parts of dodecyl mercaptan evenly, add some azobisisobutyronitrile, raise the temperature to 85°C, react for 12.5 min, then add the remaining monomer mixture and azobisisobutyronitrile to the reaction system in 9 portions, with an interval of 15 min each time. After the addition is complete, keep the reaction at the temperature for 2.5 h, cool down and discharge to obtain the modified acrylic copolymer (a total of 1.5 parts of azobisisobutyronitrile were added). The preparation process of the functional monomer is as follows: S1: Mix 24 parts of bromopentafluorobenzene, 2.5 parts of magnesium shavings, and 90 parts of diethyl ether. Raise the temperature to 38°C and reflux for 1.5 h. After cooling to room temperature, slowly add 26.5 parts of diphenyl chlorophosphate and stir for 25 min. Then raise the temperature to 75°C and reflux for 4.5 h. After cooling to room temperature, stir overnight and then perform post-processing to obtain intermediate A. S2: Mix 16.5 parts of intermediate A with 70 parts of acetone, add 2.5 parts of sodium azide, react at 45°C for 1.5 h, remove acetone by rotary evaporation, dissolve the residue in chloroform, wash with water, dry and concentrate, and purify to obtain intermediate B. S3: 12.5 parts of propynyl acrylate were added to 90 parts of N,N-dimethylformamide. Under a protective atmosphere, 53.5 parts of intermediate B, 3.5 parts of pentamethyldiethylenetriamine and 1.5 parts of cuprous bromide were added sequentially. The mixture was stirred overnight at room temperature and then post-treated to obtain the functional monomer.

[0027] Testing experiment: (1) The release force was tested according to the FTM10 standard formulated by the World Association for Self-Adhesive Labels (FINAT): the standard tape was attached to the release film obtained in the examples and comparative examples, and cut into standard strips of 25mm×130mm. The release force was tested after pressing with a standard stainless steel strip at 25°C for 20h; the release force was tested after pressing with a standard stainless steel strip at 70°C for 20h. (2) First, apply the tape to the release film obtained in the examples and comparative examples according to the standard method. Press it in a 70°C oven for 10 hours with a standard stainless steel strip. After taking it out, place it at room temperature for 1 hour. Then, peel the tape off the release film and stick it on the steel plate. After 1.5 hours, use a release force tester to test its peel force at a tensile speed of 300 mm / min and a tensile angle of 180°. Record it as N1. At the same time, stick the tape directly on the steel plate and test its peel force under the same conditions. Record it as the tensile force N2 of the blank standard sample. The formula for calculating the residual rate is: Residual rate = N1 / N2 × 100%; (3) The flame retardant properties of the release films obtained in the examples and comparative examples were tested by limiting oxygen index, and the data obtained are shown in the table below: Conclusion: This invention provides a method for preparing release film for adhesive tapes. By optimizing the release agent formulation and preparation process, the performance of the release film is significantly improved. Experimental data show that the release films of Examples 1 to 3 have release forces of 13-16 g / inch and 14-17 g / inch at 25°C and 70°C, respectively, with a residual rate as high as 96.6%-97.1% and an oxygen index of 29.8%-31.2%, exhibiting excellent release stability, adhesion retention, and flame retardant properties.

[0028] In contrast, Comparative Example 1, lacking the introduction of functional monomers, resulted in a decrease in the oxygen index to 22.3% and a residual rate to 93.4%, indicating that the absence of functional monomers weakened the flame retardant properties and the tape's adhesive retention. Comparative Example 2, lacking the introduction of acrylate siloxane monomers, saw an increase in release force to 19-20 g / inch and a significant decrease in residual rate to 86.9%, demonstrating that the absence of acrylate siloxane monomers disrupted the compatibility between the release agent and the base film, affecting the coating's uniformity and anchoring force. Furthermore, the oxygen index of Comparative Example 2 was 27.8%, higher than Comparative Example 1 but still lower than the example, further demonstrating the crucial role of the synergistic effect of functional monomers and acrylate siloxane monomers in improving the overall performance of the release film.

[0029] In summary, the preparation method of the present invention effectively solves problems such as flame retardancy, interfacial compatibility and high temperature stability by introducing functional monomers and acrylate siloxane monomers, providing an efficient and environmentally friendly solution for release films for adhesive tapes.

[0030] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0031] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing a release film for adhesive tape, characterized in that, Includes the following steps: Step 1: Mix vinyl silicone resin, modified acrylic copolymer, vinyl silicone oil, photoinitiator, defoamer, leveling agent, antioxidant, and solvent evenly, let stand to defoam, and obtain release agent; Step 2: Corona treatment is performed on one side of the polyethylene terephthalate-based film. Then, release agent is coated on the corona-treated surface. After curing and cooling, release film is obtained.

2. The method for preparing a release film for adhesive tape according to claim 1, characterized in that, The release agent comprises the following components by weight: 30-40 parts vinyl silicone resin, 10-20 parts modified acrylic copolymer, 4-5 parts vinyl silicone oil, 1-2 parts photoinitiator, 0.5-0.8 parts defoamer, 0.5-0.8 parts leveling agent, 0.5-1 part antioxidant, and 70-80 parts solvent.

3. The method for preparing a release film for adhesive tape according to claim 1, characterized in that, The preparation process of the modified acrylic copolymer is as follows: A1: Mix hydroxyl silicone resin, tetraisopropoxide titanium, stannous octoate and toluene, raise the temperature to 80-90℃, add hydroxyethyl methacrylate, continue to raise the temperature to 110-120℃, stir and react for 1-2 hours, dry and grind to obtain acrylate siloxane monomer. A2: (1) Mix acrylate siloxane monomer, ethyl acrylate, acrylamide and functional monomer evenly to obtain monomer mixture; (2) Under a protective atmosphere, mix 10wt% of monomer mixture with xylene-n-butanol mixed solvent and dodecyl mercaptan evenly, add part of azobisisobutyronitrile, raise the temperature to 80-90℃, react for 10-15min, then add the remaining monomer mixture and azobisisobutyronitrile to the reaction system in 9 portions, with an interval of 15min each time. After the addition is completed, keep the reaction at the temperature for 2-3h, cool down and discharge to obtain modified acrylic copolymer.

4. The method for preparing a release film for adhesive tape according to claim 3, characterized in that, The raw materials for preparing the acrylate siloxane monomer include the following components: by weight, 10-12 parts hydroxyl silicone resin, 0.1-0.2 parts tetraisopropoxide titanium, 0.05-0.08 parts stannous octoate, 40-50 parts toluene, and 0.7-1 parts hydroxyethyl methacrylate.

5. The method for preparing a release film for adhesive tape according to claim 3, characterized in that, The raw materials for preparing the modified acrylic copolymer include the following components: by weight, 15-20 parts acrylate siloxane monomer, 40-50 parts ethyl acrylate, 15-20 parts acrylamide, 10-12 parts functional monomer, 200-300 parts xylene-n-butanol mixed solvent, 0.5-1 part dodecyl mercaptan, and 1-2 parts azobisisobutyronitrile.

6. The method for preparing a release film for adhesive tape according to claim 3, characterized in that, The preparation process of the functional monomer is as follows: S1: Mix bromopentafluorobenzene, magnesium shavings, and diethyl ether, raise the temperature to 35-40℃, reflux for 1-2 hours, cool to room temperature, slowly add diphenyl chlorophosphate, stir for 20-30 minutes, then raise the temperature to 70-80℃, reflux for 4-5 hours, cool to room temperature, stir overnight, and then perform post-processing to obtain intermediate A. S2: Mix intermediate A with acetone, add sodium azide, react at 40-50℃ for 1-2 hours, remove acetone by rotary evaporation, dissolve the residue in chloroform, wash with water, dry and concentrate, and after purification, obtain intermediate B. S3: Propylene alcohol acrylate was added to N,N-dimethylformamide, and under a protective atmosphere, intermediate B, pentamethyldiethylenetriamine and cuprous bromide were added sequentially. The mixture was stirred overnight at room temperature and then post-treated to obtain the functional monomer.

7. The method for preparing a release film for adhesive tape according to claim 6, characterized in that, The raw materials for preparing intermediate A include the following components: by weight, 23-25 ​​parts of bromopentafluorobenzene, 2-3 parts of magnesium shavings, 80-100 parts of diethyl ether, and 25-28 parts of diphenyl chlorophosphate.

8. The method for preparing a release film for adhesive tape according to claim 6, characterized in that, The raw materials for preparing intermediate B include the following components: by weight, 15-18 parts intermediate A, 60-80 parts acetone, and 2-3 parts sodium azide.

9. The method for preparing a release film for adhesive tape according to claim 6, characterized in that, The raw materials for preparing the functional monomer include the following components: by weight, 12-13 parts propynyl acrylate, 80-100 parts N,N-dimethylformamide, 53-54 parts intermediate B, 3-4 parts pentamethyldiethylenetriamine, and 1-2 parts cuprous bromide.

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