High-viscosity anti-drag film based on microstructure and preparation method of high-viscosity anti-drag film

Abstract

The invention discloses a high-viscosity anti-drag film based on a microstructure and a preparation method of the high-viscosity anti-drag film, and relates to the technical field of anti-drag films. The high-viscosity anti-drag film comprises a release protective layer, a high-viscosity adhesive layer, a TPU substrate layer, an anti-drag functional layer and a self-cleaning coating which are sequentially stacked from bottom to top, the TPU substrate layer is a TPU film; the high-viscosity adhesive layer is obtained by coating one surface of the TPU substrate layer with a high-viscosity adhesive coating, drying and thermally curing; the resistance reducing functional layer is obtained by coating the other surface of the TPU substrate layer with polyurethane acrylate type UV curing resin and forming a small rib microstructure through thermal-optical dual curing; the self-cleaning coating is obtained by spraying a self-cleaning coating on the surface of the drag reduction functional layer and drying the self-cleaning coating.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of drag reduction film, and particularly relates to a high-adhesion drag reduction film based on microstructure and a preparation method thereof. BACKGROUND

[0002] The aviation drag reduction film is a technology for reducing air resistance by changing the microstructure of the surface of an airplane, which can significantly improve the fuel efficiency of the aircraft and reduce the operating cost. In recent years, bionics research shows that the micro-rib structure of biological surfaces such as shark skin can effectively suppress turbulent flow, thereby significantly reducing fluid friction resistance. Inspired by this, the drag reduction film technology based on surface microstructure has been widely studied and applied. Such a film usually realizes the drag reduction function by constructing a regular micro-morphology on the surface of a flexible substrate (such as a thermoplastic polyurethane elastomer, TPU). However, in order to ensure that the drag reduction film can function for a long time and stably, it must form a firm and durable bond with the surface of the device. This puts high requirements on the adhesive layer of the bottom layer of the drag reduction film: not only does it need to have very high initial adhesion and peel strength to resist the shear force and peeling force brought by high-speed fluid, but it also needs to have excellent weather resistance to cope with harsh environmental challenges such as high and low temperature alternation, humidity and heat, and ultraviolet aging.

[0003] At present, the common drag reduction film on the market mostly uses traditional acrylate pressure-sensitive adhesive as the adhesive layer. Although such an adhesive has the advantages of good initial adhesion and transparency, it often has deficiencies in low-temperature resistance, plastic resistance and long-term bonding with the TPU substrate. In a low-temperature environment, the traditional acrylate adhesive layer is prone to hardening and embrittlement, resulting in a decrease in bonding strength or even falling off; and under the action of long-term stress, the molecular chains may slip, causing cohesive failure in the adhesive layer or peeling off from the substrate.

[0004] Therefore, the present application provides a high-adhesion drag reduction film based on microstructure and a preparation method thereof, which has important significance. SUMMARY

[0005] The present application aims to provide a high-adhesion drag reduction film based on microstructure and a preparation method thereof to solve the problems in the background art.

[0006] In order to solve the above technical problems, the present application provides the following technical solutions: A high-adhesion drag reduction film based on microstructure, which is stacked from bottom to top and includes a release protective layer, a high-adhesion adhesive layer, a TPU substrate layer, a drag reduction functional layer and a self-cleaning coating layer; The TPU substrate layer is a TPU film; The high-adhesion adhesive layer is obtained by coating one side of the TPU substrate layer with high-adhesion adhesive coating, drying and heat curing; The drag-reducing functional layer is coated on the other side of the TPU base layer by polyurethane acrylate UV curing resin, and a small rib microstructure is formed by heat-light double curing to obtain; The self-cleaning coating is sprayed on the surface of the drag-reducing functional layer by a self-cleaning paint, and dried to obtain; The high-adhesion adhesive coating is obtained by mixing the following components by weight: polyurethane-modified acrylate 50 parts, terpene phenolic resin 8-12 parts, vinyl silane coupling agent 1-2 parts, multifunctional crosslinking agent 0.5-1 parts, azobisisobutyronitrile 0.4-0.6 parts, antioxidant 0.1-0.3 parts. The solid content of the high-adhesion adhesive coating is adjusted to 55-65wt% by adjusting the amount of ethyl acetate.

[0007] Further, the thickness of the high-adhesion adhesive layer is 30-50μm.

[0008] Further, the thickness of the TPU base layer is 50-100μm.

[0009] Further, the height of the small rib microstructure is 20-50μm.

[0010] Further, the thickness of the self-cleaning coating is 10-20μm.

[0011] Further, the preparation method of the high-adhesion drag-reducing film based on microstructure comprises the following steps: S1: uniformly mix polyurethane-modified acrylate, terpene phenolic resin, vinyl silane coupling agent, multifunctional crosslinking agent, azobisisobutyronitrile, and antioxidant, and adjust the amount of ethyl acetate to obtain a high-adhesion adhesive coating with a solid content of 55-65wt%; S2: coat the high-adhesion adhesive coating on one side of the TPU base layer, dry and heat cure to obtain a high-adhesion adhesive layer; and attach a release protection film on the high-adhesion adhesive layer to obtain a release protection layer; S3: coat polyurethane acrylate UV curing resin on the other side of the TPU base layer, heat cure, and mold roll light cure to form a small rib microstructure to obtain a drag-reducing functional layer; S4: spray a self-cleaning paint on the surface of the drag-reducing functional layer, dry to obtain a self-cleaning coating, and then perform laser perforation and laser cutting to obtain a high-adhesion drag-reducing film.

[0012] Further, the preparation method of the polyurethane modified acrylate is as follows: (1) Add acrylate monomer, acrylic monomer, and modifier to ethyl acetate, stir and mix evenly to obtain monomer mixed solution; add azobisisobutyronitrile to ethyl acetate, stir and mix evenly to obtain initiator solution; (2) Take 1 / 5 of the monomer mixed solution and 1 / 5 of the initiator solution and add them to the reaction vessel, stir and react at 75~95℃ for 1~2h under nitrogen protection, then slowly add the remaining monomer mixed solution and initiator solution to the reaction vessel, continue stirring and reacting, after the addition is completed, keep the reaction at the temperature for 2~6h, cool down to 38~42℃ to obtain polyurethane modified acrylate for later use.

[0013] Furthermore, the preparation of the polyurethane-modified acrylate includes the following raw material components in parts by weight: 40-50 parts of acrylate monomer, 3-6 parts of acrylic monomer, 8-12 parts of modifier, 0.8-1.2 parts of azobisisobutyronitrile, and 100 parts of ethyl acetate.

[0014] Furthermore, the acrylate monomers include, but are not limited to, one or more combinations of methyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, butyl methacrylate, and isooctyl acrylate.

[0015] Furthermore, the acrylic monomer is one or a combination of two of acrylic acid and methacrylic acid.

[0016] Further, the preparation method of the modifier is as follows: (1) Under nitrogen protection, diepoxy substances and adipate dihydrazide are added to N,N-dimethylformamide, and the reaction is carried out at room temperature for 1-6 hours. The reaction is then stopped and the product is set aside. (2) Acrylic acid, triphenylphosphine and p-methoxyphenol are added to the prepared solution in (1), and the temperature is raised to 90-100℃. The reaction is carried out for 1-3 hours. The reaction is then stopped and the intermediate product is obtained by vacuum distillation. (3) Under nitrogen protection, the intermediate product, isophorone diisocyanate and dibutyltin dilaurate are added to N,N-dimethylformamide, and the reaction is carried out at 60-70℃ for 2-4 hours. The modifier is obtained by vacuum distillation.

[0017] Furthermore, the molar ratio of the diepoxy substance and adipic acid dihydrazide is 2:1, 3:2, or 4:3.

[0018] Furthermore, the diepoxy substances include, but are not limited to, one or more combinations of diglycidyl ether, 2,2-bis(3,3'-epoxycyclohexyl)propane, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, resorcinol diglycidyl ether, and 1,4-bis(oxyglycidyl)benzene.

[0019] Furthermore, in (1), the amount of N,N-dimethylformamide used is twice the sum of the amounts of the diepoxy substance and adipic acid dihydrazide.

[0020] Furthermore, the mass ratio of the diepoxy substance, acrylic acid, triphenylphosphine, and p-methoxyphenol is 1:3:(0.12~0.16):(0.012~0.016).

[0021] Further, in (3), the mass ratio of the intermediate product, isophorone diisocyanate, dibutyltin dilaurate, and N,N-dimethylformamide is 2:1:(0.005~0.01):6.

[0022] Furthermore, the vinylsilane coupling agent is either vinyltriethoxysilane or vinyltrimethoxysilane.

[0023] Furthermore, the multifunctional crosslinking agent includes, but is not limited to, one or more combinations of ethylenediamine, diethylenetriamine, and triethylenetetramine.

[0024] Furthermore, in S2, the drying parameters are: drying temperature of 50~60℃ and drying time of 10~20min.

[0025] Furthermore, in S2 and S3, the parameters for thermosetting are: thermosetting temperature of 70~80℃ and thermosetting time of 5~10min.

[0026] Furthermore, in S3, the parameters for photocuring are: photocuring with 365nm ultraviolet light, and the ultraviolet light intensity is 40~50mW / cm². 2 The photocuring time is 30~40s.

[0027] Furthermore, in S4, the drying parameters are: drying temperature of 50~60℃ and drying time of 30~40min.

[0028] Furthermore, the spraying parameters of the self-cleaning coating are as follows: spraying with an air spray gun, spraying air pressure of 0.4~0.7MPa, spraying angle perpendicular to the surface to be sprayed, spraying distance of 15~20cm, and spray width of 10~15cm.

[0029] Furthermore, the relevant parameters for the laser perforation are: aperture diameter of 0.5mm ± 0.01mm and aperture spacing of 7mm.

[0030] Compared with the prior art, the beneficial effects achieved by the present invention are: (1) In this invention, the epoxy group of the diepoxy substance and the amino group of the adipate dihydrazide first undergo a ring-opening addition reaction to obtain a chain end containing a large number of imino groups. The ratio of the amounts used in the reaction is strictly controlled so that the chain segment obtained in (1) is end-capped with epoxy groups. In the scheme, the molar ratio of the diepoxy substance and the adipate dihydrazide is controlled to be 2:1, 3:2 or 4:3. If the molar ratio of the two is further increased, the polarity of the obtained chain segment will be too high, which will make the cohesive force of the high-viscosity adhesive layer too strong, which will reduce the adhesion performance with the TPU base layer. Then, a slightly excessive amount of acrylic acid is added to make the carboxyl group and the epoxy group undergo an esterification reaction to obtain two intermediate products containing double bonds and two hydroxyl groups. Finally, it is used as a diol to undergo a nucleophilic addition reaction with isophorone diisocyanate to obtain a polyurethane modifier. Similarly, isophorone diisocyanate is also slightly excessive to obtain a modifier containing double bonds and isocyanate groups. The modifier can participate in the polymerization reaction of acrylate monomers to prepare the polyurethane-modified acrylate. This polyurethane-modified acrylate has good compatibility with the TPU substrate and contains a large number of polar groups, which greatly ensures the adhesion between the high-tack adhesive layer and the TPU substrate, as well as the subsequent bonding strength with the adhesive surface. Furthermore, the polyurethane-modified acrylate has good flexibility, and the high-tack adhesive layer it forms has better low-temperature resistance than traditional acrylate adhesive layers, meaning the high-tack adhesive layer also has better weather resistance.

[0031] (2) The present invention adds terpene phenolic resin as a tackifying resin, which has good compatibility with polyurethane modified acrylate and can be uniformly dispersed to form a continuous phase; it can significantly improve the initial tack and peel strength of the high tack adhesive layer.

[0032] (3) The present invention further adds a vinyl silane coupling agent, which has the function of resisting external moisture erosion. As time goes by, external moisture will gradually penetrate into the high-viscosity adhesive layer. At that time, it will be hydrolyzed to form silanol groups, which ensures the bonding force between the high-viscosity adhesive layer and the TPU base layer and the subsequent bonding surface, and plays the role of enhancing the weather resistance of the high-viscosity adhesive layer. (4) In this invention, a multifunctional crosslinking agent is further added, which can crosslink with the isocyanate group on the polyurethane modified acrylate, so as to avoid the high-viscosity adhesive layer from decreasing due to molecular chain slippage during the thermosetting process.

[0033] In summary, this invention ensures the basic performance of the high-tack adhesive layer by using polyurethane-modified acrylate, and further uses terpene phenolic resin, vinyl silane coupling agent, and multifunctional crosslinking agent as auxiliary agents to comprehensively improve the adhesion performance of the high-tack adhesive layer, TPU base layer, and subsequent bonding surface. At the same time, the high-tack adhesive layer also has good weather resistance. Detailed Implementation

[0034] The technical solutions in the embodiments of the present invention will be clearly and completely described below. 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 skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] It should be noted that the following quantities are by weight, and there are no special restrictions on the suppliers of all raw materials involved in this invention. Exemplary examples include: In the following examples, acrylic acid, methyl methacrylate, methyl acrylate, ethyl acrylate, isooctyl acrylate, ethyl acetate, vinyltriethoxysilane, diethylenetriamine, antioxidant 1076, diglycidyl ether, adipic acid dihydrazide, triphenylphosphine, and p-methoxyphenol were all 99% pure and purchased from Merck Reagents Ltd. Terpene phenolic resin, model 1115, item number 8888, purchased from Dongguan Bailing New Materials Co., Ltd. The polyurethane acrylate UV-curable resin, model U-CURE 9501, with a viscosity of 10000~20000mPa·s / 60℃, was purchased from Kunshan Castel Polymer Materials Co., Ltd. Self-cleaning paint, model Ultradry SC500, purchased from Baylor Chemical Company; The TPU film, with a thickness of 100μm, is obtained by extrusion molding of TPU1460A thermoplastic polyurethane elastomer; TPU1460A thermoplastic polyurethane elastomer was purchased from Dongguan Zhangmutou Hengrun Plastic Raw Materials Co., Ltd.; each part by weight is 10g; other raw materials are all commercially available.

[0036] Preliminary preparations: 1. Methyl methacrylate, methyl acrylate, ethyl acrylate, and isooctyl acrylate are mixed in a mass ratio of 1:1:1:1 to obtain acrylate monomers; Example 1: A method for preparing a high-viscosity drag-reducing membrane based on microstructure: S1: Preparation of high-viscosity adhesive coatings: S11: Preparation of the modifier: (1) Under nitrogen protection, diglycidyl ether and adipate dihydrazide were added to N,N-dimethylformamide (the amount of N,N-dimethylformamide was twice the mass of diglycidyl ether and adipate dihydrazide) at a molar ratio of 3:2. The mixture was stirred at room temperature for 4 hours, and the reaction was stopped and the product was set aside. (2) Acrylic acid, triphenylphosphine and p-methoxyphenol were added to the prepared solution in (1). The mixture was stirred and heated to 95°C. The mixture was stirred and the reaction was stopped for 2 hours. The intermediate product was obtained by vacuum distillation. The mass ratio of diglycidyl ether, acrylic acid, triphenylphosphine, and p-methoxyphenol is 1:3:0.14:0.014; (3) Under nitrogen protection, the intermediate product, isophorone diisocyanate, and dibutyltin dilaurate are added to N,N-dimethylformamide and reacted at 65°C for 3 hours. The modifier is obtained by vacuum distillation; the mass ratio of the intermediate product, isophorone diisocyanate, dibutyltin dilaurate, and N,N-dimethylformamide is 2:1:0.0075:6; S12: Preparation of polyurethane modified acrylate: (1) Add 50 parts of acrylate monomer, 5 parts of acrylic acid, and 10 parts of modifier to 90 parts of ethyl acetate, stir and mix evenly to obtain a monomer mixed solution; add 1 part of azobisisobutyronitrile to 10 parts of ethyl acetate, stir and mix evenly to obtain an initiator solution; (2) Take 1 / 5 of the monomer mixed solution and 1 / 5 of the initiator solution and add them to the reaction vessel. Under nitrogen protection, stir and react at 85°C for 2 hours. Then slowly add the remaining monomer mixed solution and initiator solution to the reaction vessel, continue stirring and reacting. After the addition is completed, keep the reaction at the temperature for 4 hours, cool down to 40°C, and obtain polyurethane modified acrylate for later use; S13: Mix 50 parts of polyurethane modified acrylate, 10 parts of terpene phenolic resin, 1.5 parts of vinyltriethoxysilane, 0.75 parts of diglycidyl ether, 0.5 parts of azobisisobutyronitrile, and 0.2 parts of antioxidant 1076 evenly, and adjust the amount of ethyl acetate to obtain a high-viscosity adhesive coating with a solid content of 60wt%. S2: Apply a high-tack adhesive coating to one side of the TPU film, dry it at 55°C for 15 minutes, and then heat-cur it at 75°C for 8 minutes to obtain a 50μm thick high-tack adhesive layer; and attach a PET release protective film to the high-tack adhesive layer to obtain a release protective layer. S3: Coat the other side of the TPU film with polyurethane acrylate UV-curable resin, heat-cure at 75℃ for 8 minutes, then perform UV curing treatment with 365nm UV light for 35 seconds using a mold roller, with a UV light intensity of 45mW / cm². 2 This forms a small rib microstructure with a height of 50μm, resulting in a drag-reducing functional layer. S4: Using an air spray gun, with a spraying air pressure of 0.6MPa, a spraying distance of 20cm, and a spray width of 15cm, the self-cleaning coating is sprayed onto the surface of the drag-reducing functional layer. After drying at 55℃ for 30min, a 20μm thick self-cleaning coating is obtained. Then, laser perforation is performed with a hole diameter of 0.5mm±0.01mm and a hole spacing of 7mm. The hole is then laser-cut into the required shape and size to obtain a high-viscosity drag-reducing film.

[0037] Example 2: A method for preparing a high-viscosity drag-reducing membrane based on microstructure: Example 2 is based on Example 1, but the molar ratio of diglycidyl ether and adipic dihydrazide is adjusted to 2:1; S1: Preparation of high-viscosity adhesive coatings: S11: Preparation of the modifier: (1) Under nitrogen protection, diglycidyl ether and adipate dihydrazide were added to N,N-dimethylformamide (the amount of N,N-dimethylformamide was twice the mass of diglycidyl ether and adipate dihydrazide) at a molar ratio of 2:1. The mixture was stirred at room temperature for 4 hours, and the reaction was stopped and the product was set aside. (2) Acrylic acid, triphenylphosphine and p-methoxyphenol were added to the prepared solution in (1). The mixture was stirred and heated to 95°C. The mixture was stirred and the reaction was stopped for 2 hours. The intermediate product was obtained by vacuum distillation. The mass ratio of diglycidyl ether, acrylic acid, triphenylphosphine, and p-methoxyphenol is 1:3:0.14:0.014; (3) Under nitrogen protection, the intermediate product, isophorone diisocyanate, and dibutyltin dilaurate are added to N,N-dimethylformamide and reacted at 65°C for 3 hours. The modifier is obtained by vacuum distillation; the mass ratio of the intermediate product, isophorone diisocyanate, dibutyltin dilaurate, and N,N-dimethylformamide is 2:1:0.0075:6; S12: Preparation of polyurethane modified acrylate: (1) Add 50 parts of acrylate monomer, 5 parts of acrylic acid, and 10 parts of modifier to 90 parts of ethyl acetate, stir and mix evenly to obtain a monomer mixed solution; add 1 part of azobisisobutyronitrile to 10 parts of ethyl acetate, stir and mix evenly to obtain an initiator solution; (2) Take 1 / 5 of the monomer mixed solution and 1 / 5 of the initiator solution and add them to the reaction vessel. Under nitrogen protection, stir and react at 85°C for 2 hours. Then slowly add the remaining monomer mixed solution and initiator solution to the reaction vessel, continue stirring and reacting. After the addition is completed, keep the reaction at the temperature for 4 hours, cool down to 40°C, and obtain polyurethane modified acrylate for later use; S13: Mix 50 parts of polyurethane modified acrylate, 10 parts of terpene phenolic resin, 1.5 parts of vinyltriethoxysilane, 0.75 parts of diglycidyl ether, 0.5 parts of azobisisobutyronitrile, and 0.2 parts of antioxidant 1076 evenly, and adjust the amount of ethyl acetate to obtain a high-viscosity adhesive coating with a solid content of 60wt%. S2: Apply a high-tack adhesive coating to one side of the TPU film, dry it at 55°C for 15 minutes, and then heat-cur it at 75°C for 8 minutes to obtain a 50μm thick high-tack adhesive layer; and attach a PET release protective film to the high-tack adhesive layer to obtain a release protective layer. S3: Coat the other side of the TPU film with polyurethane acrylate UV-curable resin, heat-cure at 75℃ for 8 minutes, then perform UV curing treatment with 365nm UV light for 35 seconds using a mold roller, with a UV light intensity of 45mW / cm². 2 This forms a small rib microstructure with a height of 50μm, resulting in a drag-reducing functional layer. S4: Using an air spray gun, with a spraying air pressure of 0.6MPa, a spraying distance of 20cm, and a spray width of 15cm, the self-cleaning coating is sprayed onto the surface of the drag-reducing functional layer. After drying at 55℃ for 30min, a 20μm thick self-cleaning coating is obtained. Then, laser perforation is performed with a hole diameter of 0.5mm±0.01mm and a hole spacing of 7mm. The hole is then laser-cut into the required shape and size to obtain a high-viscosity drag-reducing film.

[0038] Example 3: A method for preparing a high-viscosity drag-reducing membrane based on microstructure: Example 3 is based on Example 1, but the molar ratio of diglycidyl ether and adipic dihydrazide is adjusted to 4:3; S1: Preparation of high-viscosity adhesive coatings: S11: Preparation of the modifier: (1) Under nitrogen protection, diglycidyl ether and adipate dihydrazide were added to N,N-dimethylformamide (the amount of N,N-dimethylformamide was twice the mass of diglycidyl ether and adipate dihydrazide) at a molar ratio of 4:3. The mixture was stirred at room temperature for 4 hours, and the reaction was stopped and the product was set aside. (2) Acrylic acid, triphenylphosphine and p-methoxyphenol were added to the prepared solution in (1). The mixture was stirred and heated to 95°C. The mixture was stirred and the reaction was stopped for 2 hours. The intermediate product was obtained by vacuum distillation. The mass ratio of diglycidyl ether, acrylic acid, triphenylphosphine, and p-methoxyphenol is 1:3:0.14:0.014; (3) Under nitrogen protection, the intermediate product, isophorone diisocyanate, and dibutyltin dilaurate are added to N,N-dimethylformamide and reacted at 65°C for 3 hours. The modifier is obtained by vacuum distillation; the mass ratio of the intermediate product, isophorone diisocyanate, dibutyltin dilaurate, and N,N-dimethylformamide is 2:1:0.0075:6; S12: Preparation of polyurethane modified acrylate: (1) Add 50 parts of acrylate monomer, 5 parts of acrylic acid, and 10 parts of modifier to 90 parts of ethyl acetate, stir and mix evenly to obtain a monomer mixed solution; add 1 part of azobisisobutyronitrile to 10 parts of ethyl acetate, stir and mix evenly to obtain an initiator solution; (2) Take 1 / 5 of the monomer mixed solution and 1 / 5 of the initiator solution and add them to the reaction vessel. Under nitrogen protection, stir and react at 85°C for 2 hours. Then slowly add the remaining monomer mixed solution and initiator solution to the reaction vessel, continue stirring and reacting. After the addition is completed, keep the reaction at the temperature for 4 hours, cool down to 40°C, and obtain polyurethane modified acrylate for later use; S13: Mix 50 parts of polyurethane modified acrylate, 10 parts of terpene phenolic resin, 1.5 parts of vinyltriethoxysilane, 0.75 parts of diglycidyl ether, 0.5 parts of azobisisobutyronitrile, and 0.2 parts of antioxidant 1076 evenly, and adjust the amount of ethyl acetate to obtain a high-viscosity adhesive coating with a solid content of 60wt%. S2: Apply a high-tack adhesive coating to one side of the TPU film, dry it at 55°C for 15 minutes, and then heat-cur it at 75°C for 8 minutes to obtain a 50μm thick high-tack adhesive layer; and attach a PET release protective film to the high-tack adhesive layer to obtain a release protective layer. S3: Coat the other side of the TPU film with polyurethane acrylate UV-curable resin, heat-cure at 75℃ for 8 minutes, then perform UV curing treatment with 365nm UV light for 35 seconds using a mold roller, with a UV light intensity of 45mW / cm². 2 This forms a small rib microstructure with a height of 50μm, resulting in a drag-reducing functional layer. S4: Using an air spray gun, with a spraying air pressure of 0.6MPa, a spraying distance of 20cm, and a spray width of 15cm, the self-cleaning coating is sprayed onto the surface of the drag-reducing functional layer. After drying at 55℃ for 30min, a 20μm thick self-cleaning coating is obtained. Then, laser perforation is performed with a hole diameter of 0.5mm±0.01mm and a hole spacing of 7mm. The hole is then laser-cut into the required shape and size to obtain a high-viscosity drag-reducing film.

[0039] Example 4: A method for preparing a high-viscosity drag-reducing membrane based on microstructure: Example 4 is based on Example 1, but the amount of modifier used in the preparation of polyurethane-modified acrylate is adjusted to 8 parts; S1: Preparation of high-viscosity adhesive coatings: S11: Preparation of the modifier: (1) Under nitrogen protection, diglycidyl ether and adipate dihydrazide were added to N,N-dimethylformamide (the amount of N,N-dimethylformamide was twice the mass of diglycidyl ether and adipate dihydrazide) at a molar ratio of 2:1. The mixture was stirred at room temperature for 4 hours, and the reaction was stopped and the product was set aside. (2) Acrylic acid, triphenylphosphine and p-methoxyphenol were added to the prepared solution in (1). The mixture was stirred and heated to 95°C. The mixture was stirred and the reaction was stopped for 2 hours. The intermediate product was obtained by vacuum distillation. The mass ratio of diglycidyl ether, acrylic acid, triphenylphosphine, and p-methoxyphenol is 1:3:0.14:0.014; (3) Under nitrogen protection, the intermediate product, isophorone diisocyanate, and dibutyltin dilaurate are added to N,N-dimethylformamide and reacted at 65°C for 3 hours. The modifier is obtained by vacuum distillation; the mass ratio of the intermediate product, isophorone diisocyanate, dibutyltin dilaurate, and N,N-dimethylformamide is 2:1:0.0075:6; S12: Preparation of polyurethane modified acrylate: (1) Add 50 parts of acrylate monomer, 5 parts of acrylic acid, and 8 parts of modifier to 90 parts of ethyl acetate, stir and mix evenly to obtain a monomer mixed solution; add 1 part of azobisisobutyronitrile to 10 parts of ethyl acetate, stir and mix evenly to obtain an initiator solution; (2) Take 1 / 5 of the monomer mixed solution and 1 / 5 of the initiator solution and add them to the reaction vessel. Under nitrogen protection, stir and react at 85°C for 2 hours. Then slowly add the remaining monomer mixed solution and initiator solution to the reaction vessel, continue stirring and reacting. After the addition is complete, keep the reaction at the temperature for 4 hours, cool down to 40°C, and obtain polyurethane modified acrylate for later use; S13: Mix 50 parts of polyurethane modified acrylate, 10 parts of terpene phenolic resin, 1.5 parts of vinyltriethoxysilane, 0.75 parts of diglycidyl ether, 0.5 parts of azobisisobutyronitrile, and 0.2 parts of antioxidant 1076 evenly, and adjust the amount of ethyl acetate to obtain a high-viscosity adhesive coating with a solid content of 60wt%. S2: Apply a high-tack adhesive coating to one side of the TPU film, dry it at 55°C for 15 minutes, and then heat-cur it at 75°C for 8 minutes to obtain a 50μm thick high-tack adhesive layer; and attach a PET release protective film to the high-tack adhesive layer to obtain a release protective layer. S3: Coat the other side of the TPU film with polyurethane acrylate UV-curable resin, heat-cure at 75℃ for 8 minutes, then perform UV curing treatment with 365nm UV light for 35 seconds using a mold roller, with a UV light intensity of 45mW / cm². 2 This forms a small rib microstructure with a height of 50μm, resulting in a drag-reducing functional layer. S4: Using an air spray gun, with a spraying air pressure of 0.6MPa, a spraying distance of 20cm, and a spray width of 15cm, the self-cleaning coating is sprayed onto the surface of the drag-reducing functional layer. After drying at 55℃ for 30min, a 20μm thick self-cleaning coating is obtained. Then, laser perforation is performed with a hole diameter of 0.5mm±0.01mm and a hole spacing of 7mm. The hole is then laser-cut into the required shape and size to obtain a high-viscosity drag-reducing film.

[0040] Example 5: A method for preparing a high-viscosity drag-reducing membrane based on microstructure: Example 5 is based on Example 1, but the amount of modifier used in the preparation of polyurethane-modified acrylate is adjusted to 12 parts; S1: Preparation of high-viscosity adhesive coatings: S11: Preparation of the modifier: (1) Under nitrogen protection, diglycidyl ether and adipate dihydrazide were added to N,N-dimethylformamide (the amount of N,N-dimethylformamide was twice the mass of diglycidyl ether and adipate dihydrazide) at a molar ratio of 2:1. The mixture was stirred at room temperature for 4 hours, and the reaction was stopped and the product was set aside. (2) Acrylic acid, triphenylphosphine and p-methoxyphenol were added to the prepared solution in (1). The mixture was stirred and heated to 95°C. The mixture was stirred and the reaction was stopped for 2 hours. The intermediate product was obtained by vacuum distillation. The mass ratio of diglycidyl ether, acrylic acid, triphenylphosphine, and p-methoxyphenol is 1:3:0.14:0.014; (3) Under nitrogen protection, the intermediate product, isophorone diisocyanate, and dibutyltin dilaurate are added to N,N-dimethylformamide and reacted at 65°C for 3 hours. The modifier is obtained by vacuum distillation; the mass ratio of the intermediate product, isophorone diisocyanate, dibutyltin dilaurate, and N,N-dimethylformamide is 2:1:0.0075:6; S12: Preparation of polyurethane modified acrylate: (1) Add 50 parts of acrylate monomer, 5 parts of acrylic acid, and 12 parts of modifier to 90 parts of ethyl acetate, stir and mix evenly to obtain a monomer mixed solution; add 1 part of azobisisobutyronitrile to 10 parts of ethyl acetate, stir and mix evenly to obtain an initiator solution; (2) Take 1 / 5 of the monomer mixed solution and 1 / 5 of the initiator solution and add them to the reaction vessel. Under nitrogen protection, stir and react at 85°C for 2 hours. Then slowly add the remaining monomer mixed solution and initiator solution to the reaction vessel, continue stirring and reacting. After the addition is completed, keep the temperature for 4 hours and cool down to 40°C to obtain polyurethane modified acrylate for later use. S13: Mix 50 parts of polyurethane modified acrylate, 10 parts of terpene phenolic resin, 1.5 parts of vinyltriethoxysilane, 0.75 parts of diglycidyl ether, 0.5 parts of azobisisobutyronitrile, and 0.2 parts of antioxidant 1076 evenly, and adjust the amount of ethyl acetate to obtain a high-viscosity adhesive coating with a solid content of 60wt%. S2: Apply a high-tack adhesive coating to one side of the TPU film, dry it at 55°C for 15 minutes, and then heat-cur it at 75°C for 8 minutes to obtain a 50μm thick high-tack adhesive layer; and attach a PET release protective film to the high-tack adhesive layer to obtain a release protective layer. S3: Coat the other side of the TPU film with polyurethane acrylate UV-curable resin, heat-cure at 75℃ for 8 minutes, then perform UV curing treatment with 365nm UV light for 35 seconds using a mold roller, with a UV light intensity of 45mW / cm². 2 This forms a small rib microstructure with a height of 50μm, resulting in a drag-reducing functional layer. S4: Using an air spray gun, with a spraying air pressure of 0.6MPa, a spraying distance of 20cm, and a spray width of 15cm, the self-cleaning coating is sprayed onto the surface of the drag-reducing functional layer. After drying at 55℃ for 30min, a 20μm thick self-cleaning coating is obtained. Then, laser perforation is performed with a hole diameter of 0.5mm±0.01mm and a hole spacing of 7mm. The hole is then laser-cut into the required shape and size to obtain a high-viscosity drag-reducing film.

[0041] The following are control experiments based on Example 1, specifically: Comparative Examples 1-4: Comparative Example 1: Comparative Example 1 is based on Example 1, with the following adjustments: no modifier is added in S12, and acrylic monomer is used instead, while other processes remain unchanged. Specifically: A method for preparing a high-viscosity drag-reducing membrane based on microstructure: S1: Preparation of high-viscosity adhesive coatings: S12: Preparation of polyurethane modified acrylate: (1) Add 60 parts of acrylate monomer and 5 parts of acrylic acid to 90 parts of ethyl acetate, stir and mix evenly to obtain a monomer mixed solution; add 1 part of azobisisobutyronitrile to 10 parts of ethyl acetate, stir and mix evenly to obtain an initiator solution; (2) Take 1 / 5 of the monomer mixed solution and 1 / 5 of the initiator solution and add them to the reaction vessel. Under nitrogen protection, stir and react at 85°C for 2 hours. Then slowly add the remaining monomer mixed solution and initiator solution to the reaction vessel, continue stirring and reacting. After the addition is completed, keep the temperature for 4 hours and cool down to 40°C to obtain polyurethane modified acrylate for later use. S13: Mix 50 parts of polyurethane modified acrylate, 10 parts of terpene phenolic resin, 1.5 parts of vinyltriethoxysilane, 0.75 parts of diglycidyl ether, 0.5 parts of azobisisobutyronitrile, and 0.2 parts of antioxidant 1076 evenly, and adjust the amount of ethyl acetate to obtain a high-viscosity adhesive coating with a solid content of 60wt%. S2: Apply a high-tack adhesive coating to one side of the TPU film, dry it at 55°C for 15 minutes, and then heat-cur it at 75°C for 8 minutes to obtain a 50μm thick high-tack adhesive layer; and attach a PET release protective film to the high-tack adhesive layer to obtain a release protective layer. S3: Coat the other side of the TPU film with polyurethane acrylate UV-curable resin, heat-cure at 75℃ for 8 minutes, then perform UV curing treatment with 365nm UV light for 35 seconds using a mold roller, with a UV light intensity of 45mW / cm². 2 This forms a small rib microstructure with a height of 50μm, resulting in a drag-reducing functional layer. S4: Using an air spray gun, with a spraying air pressure of 0.6MPa, a spraying distance of 20cm, and a spray width of 15cm, the self-cleaning coating is sprayed onto the surface of the drag-reducing functional layer. After drying at 55℃ for 30min, a 20μm thick self-cleaning coating is obtained. Then, laser perforation is performed with a hole diameter of 0.5mm±0.01mm and a hole spacing of 7mm. The hole is then laser-cut into the required shape and size to obtain a high-viscosity drag-reducing film.

[0042] Comparative Example 2: Comparative Example 2 is based on Example 1, with the following adjustments: terpene phenolic resin is not added to the high-viscosity adhesive coating; this portion is replaced with polyurethane-modified acrylate. Other processes remain unchanged. Specifically: A method for preparing a high-viscosity drag-reducing membrane based on microstructure: S1: Preparation of high-viscosity adhesive coatings: S11: Preparation of the modifier: (1) Under nitrogen protection, diglycidyl ether and adipate dihydrazide were added to N,N-dimethylformamide (the amount of N,N-dimethylformamide was twice the mass of diglycidyl ether and adipate dihydrazide) at a molar ratio of 3:2. The mixture was stirred at room temperature for 4 hours, and the reaction was stopped and the product was set aside. (2) Acrylic acid, triphenylphosphine and p-methoxyphenol were added to the prepared solution in (1). The mixture was stirred and heated to 95°C. The mixture was stirred and the reaction was stopped for 2 hours. The intermediate product was obtained by vacuum distillation. The mass ratio of diglycidyl ether, acrylic acid, triphenylphosphine, and p-methoxyphenol is 1:3:0.14:0.014; (3) Under nitrogen protection, the intermediate product, isophorone diisocyanate, and dibutyltin dilaurate are added to N,N-dimethylformamide and reacted at 65°C for 3 hours. The modifier is obtained by vacuum distillation; the mass ratio of the intermediate product, isophorone diisocyanate, dibutyltin dilaurate, and N,N-dimethylformamide is 2:1:0.0075:6; S12: Preparation of polyurethane modified acrylate: (1) Add 50 parts of acrylate monomer, 5 parts of acrylic acid, and 10 parts of modifier to 90 parts of ethyl acetate, stir and mix evenly to obtain a monomer mixed solution; add 1 part of azobisisobutyronitrile to 10 parts of ethyl acetate, stir and mix evenly to obtain an initiator solution; (2) Take 1 / 5 of the monomer mixed solution and 1 / 5 of the initiator solution and add them to the reaction vessel. Under nitrogen protection, stir and react at 85°C for 2 hours. Then slowly add the remaining monomer mixed solution and initiator solution to the reaction vessel, continue stirring and reacting. After the addition is completed, keep the reaction at the temperature for 4 hours, cool down to 40°C, and obtain polyurethane modified acrylate for later use; S13: Mix 60 parts of polyurethane modified acrylate, 1.5 parts of vinyltriethoxysilane, 0.75 parts of diglycidyl ether, 0.5 parts of azobisisobutyronitrile, and 0.2 parts of antioxidant 1076 evenly, and adjust the amount of ethyl acetate to obtain a high-viscosity adhesive coating with a solid content of 60wt%. S2: Apply a high-tack adhesive coating to one side of the TPU film, dry it at 55°C for 15 minutes, and then heat-cur it at 75°C for 8 minutes to obtain a 50μm thick high-tack adhesive layer; and attach a PET release protective film to the high-tack adhesive layer to obtain a release protective layer. S3: Coat the other side of the TPU film with polyurethane acrylate UV-curable resin, heat-cure at 75℃ for 8 minutes, then perform UV curing treatment with 365nm UV light for 35 seconds using a mold roller, with a UV light intensity of 45mW / cm². 2 This forms a small rib microstructure with a height of 50μm, resulting in a drag-reducing functional layer. S4: Using an air spray gun, with a spraying air pressure of 0.6MPa, a spraying distance of 20cm, and a spray width of 15cm, the self-cleaning coating is sprayed onto the surface of the drag-reducing functional layer. After drying at 55℃ for 30min, a 20μm thick self-cleaning coating is obtained. Then, laser perforation is performed with a hole diameter of 0.5mm±0.01mm and a hole spacing of 7mm. The hole is then laser-cut into the required shape and size to obtain a high-viscosity drag-reducing film.

[0043] Comparative Example 3: Comparative Example 3 is based on Example 1, with the following adjustments: vinyltriethoxysilane is not added, and this portion is replaced with polyurethane-modified acrylate; other processes remain unchanged. Specifically: A method for preparing a high-viscosity drag-reducing membrane based on microstructure: S1: Preparation of high-viscosity adhesive coatings: S11: Preparation of the modifier: (1) Under nitrogen protection, diglycidyl ether and adipate dihydrazide were added to N,N-dimethylformamide (the amount of N,N-dimethylformamide was twice the mass of diglycidyl ether and adipate dihydrazide) at a molar ratio of 3:2. The mixture was stirred at room temperature for 4 hours, and the reaction was stopped and the product was set aside. (2) Acrylic acid, triphenylphosphine and p-methoxyphenol were added to the prepared solution in (1). The mixture was stirred and heated to 95°C. The mixture was stirred and the reaction was stopped for 2 hours. The intermediate product was obtained by vacuum distillation. The mass ratio of diglycidyl ether, acrylic acid, triphenylphosphine, and p-methoxyphenol is 1:3:0.14:0.014; (3) Under nitrogen protection, the intermediate product, isophorone diisocyanate, and dibutyltin dilaurate are added to N,N-dimethylformamide and reacted at 65°C for 3 hours. The modifier is obtained by vacuum distillation; the mass ratio of the intermediate product, isophorone diisocyanate, dibutyltin dilaurate, and N,N-dimethylformamide is 2:1:0.0075:6; S12: Preparation of polyurethane modified acrylate: (1) Add 50 parts of acrylate monomer, 5 parts of acrylic acid, and 10 parts of modifier to 90 parts of ethyl acetate, stir and mix evenly to obtain a monomer mixed solution; add 1 part of azobisisobutyronitrile to 10 parts of ethyl acetate, stir and mix evenly to obtain an initiator solution; (2) Take 1 / 5 of the monomer mixed solution and 1 / 5 of the initiator solution and add them to the reaction vessel. Under nitrogen protection, stir and react at 85°C for 2 hours. Then slowly add the remaining monomer mixed solution and initiator solution to the reaction vessel, continue stirring and reacting. After the addition is completed, keep the reaction at the temperature for 4 hours, cool down to 40°C, and obtain polyurethane modified acrylate for later use; S13: Mix 51.5 parts of polyurethane modified acrylate, 10 parts of terpene phenolic resin, 0.75 parts of diglycidyl ether, 0.5 parts of azobisisobutyronitrile, and 0.2 parts of antioxidant 1076 evenly, and adjust the amount of ethyl acetate to obtain a high-viscosity adhesive coating with a solid content of 60wt%. S2: Apply a high-tack adhesive coating to one side of the TPU film, dry it at 55°C for 15 minutes, and then heat-cur it at 75°C for 8 minutes to obtain a 50μm thick high-tack adhesive layer; and attach a PET release protective film to the high-tack adhesive layer to obtain a release protective layer. S3: Coat the other side of the TPU film with polyurethane acrylate UV-curable resin, heat-cure at 75℃ for 8 minutes, then perform UV curing treatment with 365nm UV light for 35 seconds using a mold roller, with a UV light intensity of 45mW / cm². 2 This forms a small rib microstructure with a height of 50μm, resulting in a drag-reducing functional layer. S4: Using an air spray gun, with a spraying air pressure of 0.6MPa, a spraying distance of 20cm, and a spray width of 15cm, the self-cleaning coating is sprayed onto the surface of the drag-reducing functional layer. After drying at 55℃ for 30min, a 20μm thick self-cleaning coating is obtained. Then, laser perforation is performed with a hole diameter of 0.5mm±0.01mm and a hole spacing of 7mm. The hole is then laser-cut into the required shape and size to obtain a high-viscosity drag-reducing film.

[0044] Comparative Example 4: Comparative Example 4 is based on Example 1, with the following adjustments: diglycidyl ether (a multifunctional crosslinking agent) is not added, and its amount is replaced with polyurethane-modified acrylate; other processes remain unchanged. Specifically: A method for preparing a high-viscosity drag-reducing membrane based on microstructure: S1: Preparation of high-viscosity adhesive coatings: S11: Preparation of the modifier: (1) Under nitrogen protection, diglycidyl ether and adipate dihydrazide were added to N,N-dimethylformamide (the amount of N,N-dimethylformamide was twice the mass of diglycidyl ether and adipate dihydrazide) at a molar ratio of 3:2. The mixture was stirred at room temperature for 4 hours, and the reaction was stopped and the product was set aside. (2) Acrylic acid, triphenylphosphine and p-methoxyphenol were added to the prepared solution in (1). The mixture was stirred and heated to 95°C. The mixture was stirred and the reaction was stopped for 2 hours. The intermediate product was obtained by vacuum distillation. The mass ratio of diglycidyl ether, acrylic acid, triphenylphosphine, and p-methoxyphenol is 1:3:0.14:0.014; (3) Under nitrogen protection, the intermediate product, isophorone diisocyanate, and dibutyltin dilaurate are added to N,N-dimethylformamide and reacted at 65°C for 3 hours. The modifier is obtained by vacuum distillation; the mass ratio of the intermediate product, isophorone diisocyanate, dibutyltin dilaurate, and N,N-dimethylformamide is 2:1:0.0075:6; S12: Preparation of polyurethane modified acrylate: (1) Add 50 parts of acrylate monomer, 5 parts of acrylic acid, and 10 parts of modifier to 90 parts of ethyl acetate, stir and mix evenly to obtain a monomer mixed solution; add 1 part of azobisisobutyronitrile to 10 parts of ethyl acetate, stir and mix evenly to obtain an initiator solution; (2) Take 1 / 5 of the monomer mixed solution and 1 / 5 of the initiator solution and add them to the reaction vessel. Under nitrogen protection, stir and react at 85°C for 2 hours. Then slowly add the remaining monomer mixed solution and initiator solution to the reaction vessel, continue stirring and reacting. After the addition is completed, keep the reaction at the temperature for 4 hours, cool down to 40°C, and obtain polyurethane modified acrylate for later use; S13: Mix 50.75 parts of polyurethane modified acrylate, 10 parts of terpene phenolic resin, 1.5 parts of vinyltriethoxysilane, 0.5 parts of azobisisobutyronitrile, and 0.2 parts of antioxidant 1076 evenly, and adjust the amount of ethyl acetate to obtain a high-viscosity adhesive coating with a solid content of 60wt%. S2: Apply a high-tack adhesive coating to one side of the TPU film, dry it at 55°C for 15 minutes, and then heat-cur it at 75°C for 8 minutes to obtain a 50μm thick high-tack adhesive layer; and attach a PET release protective film to the high-tack adhesive layer to obtain a release protective layer. S3: Coat the other side of the TPU film with polyurethane acrylate UV-curable resin, heat-cure at 75℃ for 8 minutes, then perform UV curing treatment with 365nm UV light for 35 seconds using a mold roller, with a UV light intensity of 45mW / cm². 2 This forms a small rib microstructure with a height of 50μm, resulting in a drag-reducing functional layer. S4: Using an air spray gun, with a spraying air pressure of 0.6MPa, a spraying distance of 20cm, and a spray width of 15cm, the self-cleaning coating is sprayed onto the surface of the drag-reducing functional layer. After drying at 55℃ for 30min, a 20μm thick self-cleaning coating is obtained. Then, laser perforation is performed with a hole diameter of 0.5mm±0.01mm and a hole spacing of 7mm. The hole is then laser-cut into the required shape and size to obtain a high-viscosity drag-reducing film.

[0045] Performance testing: The high-viscosity drag-reducing films prepared in Examples 1-5 and Comparative Examples 1-4 were laser-cut into samples 300 mm long and 24 mm wide. Peel strength and low-temperature resistance tests were conducted. The specific test methods are as follows: (1) Peel strength test: According to the standard GB / T 2792-2014, the release liner of the sample corresponding to each example was peeled off, and the high-tack adhesive layer was flatly attached to the surface of the 06Cr19N110 stainless steel plate (125mm long, 50mm wide, 1.1mm thick, and 50nm roughness). A pressure roller with a diameter of 85mm, a width of 45mm, a surface covered with about 6mm thick rubber, a hardness of 80A, and a mass of 2000g was used to press the roller back and forth twice at a speed of 10mm / s. Then, at 23℃ and 50% relative humidity, a tensile testing machine was used to conduct a 180° peel strength test at a speed of 5mm / s. (2) Low temperature resistance test: According to the standard GB / T 2792-2014, the samples corresponding to each example and the stainless steel plates with the same as above were placed in a -25℃ environment for 2 hours and then removed; the above-mentioned attachment and pressure roller operation was repeated; then the stainless steel plates after pressure roller were placed in a -25℃ environment for 24 hours and removed; a tensile testing machine was used to perform a 180° peel strength test at a speed of 5 mm / s.

[0046] The data results for the above test items are shown in Table 1 below: Table 1

[0047] Results Analysis: As can be seen from the data in Table 1 above, in this invention, the basic performance of the high-tack adhesive layer is ensured by polyurethane-modified acrylate, and further assisted by terpene phenolic resin, vinyl silane coupling agent and multifunctional crosslinking agent, which together make the high-tack adhesive layer, TPU base layer and subsequent bonding surface have excellent adhesion performance. At the same time, the high-tack adhesive layer also has good low-temperature resistance.

[0048] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-viscosity drag-reducing membrane based on a microstructure, characterized in that: The layers stacked from bottom to top include: a release protective layer, a high-adhesion adhesive layer, a TPU base layer, a drag-reducing functional layer, and a self-cleaning coating. The TPU base layer is a TPU film; The high-tack adhesive layer is obtained by coating one side of a TPU base layer with a high-tack adhesive coating, followed by drying and heat curing. The drag-reducing functional layer is obtained by coating a polyurethane acrylate UV-curable resin onto the other side of a TPU base layer and then curing it with heat and light to form a small rib microstructure. The self-cleaning coating is obtained by spraying self-cleaning paint onto the surface of the drag-reducing functional layer and then drying it. The high-viscosity adhesive coating is obtained by mixing the following raw material components in parts by weight: 50 parts of polyurethane modified acrylate, 8-12 parts of terpene phenolic resin, 1-2 parts of vinyl silane coupling agent, 0.5-1 part of multifunctional crosslinking agent, 0.4-0.6 parts of azobisisobutyronitrile, and 0.1-0.3 parts of antioxidant. The solid content of the high-viscosity adhesive coating is adjusted to 55-65 wt% by adjusting the amount of ethyl acetate.

2. The high-viscosity drag-reducing membrane based on microstructure according to claim 1, characterized in that: The preparation method of the polyurethane-modified acrylate is as follows: (1) Add acrylate monomer, acrylic monomer, and modifier to ethyl acetate, stir and mix evenly to obtain monomer mixed solution; add azobisisobutyronitrile to ethyl acetate, stir and mix evenly to obtain initiator solution; (2) Take 1 / 5 of the monomer mixture solution and 1 / 5 of the initiator solution and add them to the reaction vessel. Under nitrogen protection, stir the reaction at 75~95℃ for 1~2h. Then slowly add the remaining monomer mixture solution and initiator solution to the reaction vessel and continue stirring the reaction. After the addition is complete, keep the reaction at the temperature for 2~6h and cool it down to 38~42℃ to obtain polyurethane modified acrylate for later use. The preparation of polyurethane modified acrylate includes the following raw material components in parts by weight: 40-50 parts of acrylate monomer, 3-6 parts of acrylic monomer, 8-12 parts of modifier, 0.8-1.2 parts of azobisisobutyronitrile, and 100 parts of ethyl acetate.

3. The high-viscosity drag-reducing membrane based on microstructure according to claim 2, characterized in that: The acrylate monomers include one or more combinations of methyl methacrylate, methyl acrylate, ethyl acrylate, butyl acrylate, butyl methacrylate, and isooctyl acrylate; The acrylic monomer is one or a combination of two of acrylic acid and methacrylic acid.

4. The high-viscosity drag-reducing membrane based on microstructure according to claim 2, characterized in that: The method for preparing the modifier is as follows: (1) Under nitrogen protection, add the diepoxy substance and adipic acid dihydrazide to N,N-dimethylformamide, stir the reaction at room temperature for 1-6 h, and then stop the reaction for later use; (2) Add acrylic acid, triphenylphosphine and p-methoxyphenol to the prepared solution in (1), stir and heat to 90~100℃, stir and react for 1~3h, stop the reaction, and obtain the intermediate product by vacuum distillation; (3) Under nitrogen protection, the intermediate product, isophorone diisocyanate and dibutyltin dilaurate were added to N,N-dimethylformamide and reacted at 60~70℃ for 2~4h. The modifier was obtained by vacuum distillation. The molar ratio of the diepoxy substance and adipic acid dihydrazide is 2:1, 3:2, or 4:

3. Diepoxy compounds include one or more combinations of diglycidyl ether, 2,2-bis(3,3'-epoxycyclohexyl)propane, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether, resorcinol diglycidyl ether, and 1,4-bis(oxyglycidyl)benzene. In (1), the amount of N,N-dimethylformamide is twice the sum of the amounts of the diepoxy substance and the adipic acid dihydrazide. The mass ratio of the diepoxygenated substance, acrylic acid, triphenylphosphine, and p-methoxyphenol is 1:3:(0.12~0.16):(0.012~0.016); In (3), the mass ratio of the intermediate product, isophorone diisocyanate, dibutyltin dilaurate, and N,N-dimethylformamide is 2:1:(0.005~0.01):

6.

5. The high-viscosity drag-reducing membrane based on microstructure according to claim 1, characterized in that: The vinyl silane coupling agent is either vinyltriethoxysilane or vinyltrimethoxysilane; The multifunctional crosslinking agent includes one or more combinations of ethylenediamine, diethylenetriamine, and triethylenetetramine.

6. The high-viscosity drag-reducing membrane based on microstructure according to claim 1, characterized in that: The thickness of the high-viscosity adhesive layer is 30~50μm; The thickness of the TPU base layer is 50~100μm; The height of the rib microstructure is 20~50μm; The thickness of the self-cleaning coating is 10~20μm.

7. A method for preparing a high-viscosity drag-reducing membrane based on a microstructure according to any one of claims 1 to 6, characterized in that: Includes the following steps: S1: Polyurethane modified acrylate, terpene phenolic resin, vinyl silane coupling agent, multifunctional crosslinking agent, azobisisobutyronitrile, and antioxidant are stirred and mixed evenly, and the amount of ethyl acetate is adjusted to obtain a high-viscosity adhesive coating. S2: Apply a high-tack adhesive coating to one side of the TPU base layer, dry and heat-cur it to obtain a high-tack adhesive layer; and attach a release protective film to the high-tack adhesive layer to obtain a release protective layer. S3: Apply polyurethane acrylate UV-curable resin to the other side of the TPU base layer, and then heat-cur and mold roller light-cur to form a small rib microstructure to obtain a drag-reducing functional layer. S4: Spray the self-cleaning coating onto the surface of the drag-reducing functional layer, and after drying, obtain the self-cleaning coating; then perform laser perforation and laser cutting to obtain a high-viscosity drag-reducing film.

8. The method for preparing a high-viscosity drag-reducing membrane based on a microstructure according to claim 7, characterized in that: In S2, the drying parameters are: drying temperature of 50~60℃ and drying time of 10~20min; In S2 and S3, the parameters for heat curing are: heat curing temperature of 70~80℃ and heat curing time of 5~10min; In S3, the photocuring parameters are: photocuring with 365nm ultraviolet light, and the ultraviolet light intensity is 40~50mW / cm². 2 The photocuring time is 30~40s; In S4, the drying parameters are: drying temperature of 50~60℃ and drying time of 30~40min.

9. The method for preparing a high-viscosity drag-reducing membrane based on a microstructure according to claim 7, characterized in that: The spraying parameters for the self-cleaning coating are as follows: spraying with an air spray gun, spraying air pressure of 0.4~0.7MPa, spraying angle perpendicular to the surface to be sprayed, spraying distance of 15~20cm, and spray width of 10~15cm.

10. The method for preparing a high-viscosity drag-reducing membrane based on a microstructure according to claim 7, characterized in that: The relevant parameters for laser perforation are: aperture diameter of 0.5mm ± 0.01mm and aperture spacing of 7mm.

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