A surface high wear-resistant high-low temperature film and a preparation method thereof

Abstract

The application relates to the technical field of high polymer materials, in particular to a surface high-wear-resistance high-low-temperature film and a preparation method thereof, which comprises the following steps: wear-resistance layer preparation: sequentially coating and drying a PU surface wear-resistance layer, a second PU intermediate wear-resistance layer, a first PU intermediate wear-resistance layer and a PU contact layer on a release paper to obtain a wear-resistance layer; high-low-temperature layer film preparation: preparing a TPU high-temperature layer film and a TPU hot melt adhesive layer film through a flow casting method; laminating and compounding: heating the TPU high-temperature layer film to 155-175 DEG C, then pasting the TPU high-temperature layer film to the PU contact layer of the wear-resistance layer within 0.5-3 s, meanwhile, stacking the TPU hot melt adhesive layer film on the other side of the TPU high-temperature layer film, 5-15 MPa hot pressing, forced cooling and peeling off the release paper, and the finished product is obtained. Through optimization of components and processes, the application solves the contradiction that different layers of films have different temperature requirements, a high-wear-resistance layer with good heat resistance is prepared, and the high-wear-resistance layer is not prone to discoloration.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, specifically to a high-wear-resistant high- and low-temperature film and its preparation method. Background Technology

[0002] Thermoplastic polyurethane elastomer (TPU) high and low temperature films are widely used in textiles, bags, and other fields due to their unique structure (one side with a high melting point and the other with a low melting point). In recent years, the industry has attempted to apply them to footwear materials, especially as functional layer soles. For example, in composite sole structures, it is desirable to laminate an extremely thin but highly wear-resistant and slip-resistant functional layer onto the outside of a foamed midsole (such as EVA or MD), thereby giving the sole superior contact performance without significantly increasing weight and thickness. However, existing TPU high and low temperature films and composite technologies are difficult to meet the stringent requirements of this specific application scenario. For example, the high-filling modification method commonly used to improve wear resistance, while increasing the wear life of the material to some extent, leads to excessively high film hardness and loss of flexibility. When this rigid film is composited with a soft foamed midsole as a functional layer, the modulus mismatch between the two during continuous bending while walking can easily cause the functional layer to crack brittlely or detach from the base, and the hard feel also sacrifices the slip resistance and comfort that the sole should have. Another technical solution involves coating an ultra-thin abrasion-resistant textured layer, where the adhesion between the coating and the substrate relies primarily on physical adhesion. When this film is used as a functional layer in shoe soles, continuously subjected to ground impacts, friction, and complex environmental temperature and humidity changes, this interface becomes a mechanical weak point. The coating risks peeling off from the base film, leading to unsustainable abrasion resistance and significantly shortened product lifespan. Furthermore, in the preparation of multi-layer composite functional films, the materials and thermophysical properties (such as melting point and heat resistance) of each functional layer (e.g., abrasion-resistant layer, support layer, adhesive layer) differ significantly. This makes it difficult to find a unified and optimized process temperature window during hot-pressing: excessively high temperatures may damage the abrasion-resistant layer with poor heat resistance or cause deformation and discoloration; excessively low temperatures may prevent the hot melt adhesive layer from fully melting or achieving strong bonding between layers. This contradiction in the inconsistent temperature requirements of each layer results in a narrow composite process window, making the production process difficult to control and severely impacting product yield and performance stability.

[0003] CN 118325497 A relates to a wear-resistant TPU high and low temperature film, its preparation method, and its application. The film comprises a release paper layer, a TPU substrate layer, and a hot melt adhesive film layer arranged sequentially. The surface of the release paper layer is printed with a lychee pattern or calfskin pattern. The TPU substrate layer is coated with a wear-resistant TPU composite material. The wear-resistant TPU composite material comprises the following raw materials in parts by weight: 60-80 parts of fluorinated TPU particles, 10-20 parts of EVA, 4-8 parts of polyoxypropylene ether polyol, 1-5 parts of triethylvinylsilane, 1-3 parts of defoamer, 5-10 parts of modifier, 3-6 parts of leveling agent, 1-5 parts of chain extender, 10-15 parts of filler, and 40-60 parts of solvent. CN116769414 B relates to the field of TPU technology, specifically to a textured TPU high and low temperature film and a TPU film preparation method thereof. The textured TPU high and low temperature film comprises, from top to bottom, a textured layer, a TPU carrier layer, and a hot melt adhesive layer. The textured TPU film itself comprises, from top to bottom, a textured layer and a TPU carrier layer. Both the textured TPU high and low temperature film and the TPU film can be in roll or sheet form, offering a wide range of applications. The textured layer is made of polyurethane UV adhesive coating, and the TPU carrier layer is made of modified TPU high and low temperature film. However, the aforementioned existing technologies have failed to resolve the contradiction of inconsistent temperature requirements among the various film layers. Summary of the Invention

[0004] To address the aforementioned issues, this invention provides a high-wear-resistant high- and low-temperature film and its preparation method. By optimizing the composition and process, the contradiction of inconsistent temperature requirements among different film layers is resolved, resulting in a high-wear-resistant layer with good heat resistance and minimal discoloration.

[0005] A method for preparing a high-wear-resistant high- and low-temperature film includes the following steps:

[0006] Abrasion-resistant layer preparation: Abrasion-resistant PU surface layer, abrasion-resistant PU intermediate layer, abrasion-resistant PU intermediate layer, and PU contact layer are sequentially coated and dried on release paper to obtain abrasion-resistant layer;

[0007] High and low temperature film preparation: TPU high temperature film and TPU hot melt adhesive film were prepared by casting method;

[0008] Lamination: The TPU high-temperature film is heated to 155-175℃, and then applied to the PU contact layer of the wear-resistant layer within 0.5-3 seconds. At the same time, the TPU hot melt adhesive film is stacked on the other side of the TPU high-temperature film, and hot-pressed at a pressure of 5-15 MPa. After pressing, forced cooling is performed immediately, and finally the release paper is peeled off to obtain the finished product.

[0009] The core of the preparation method of this invention lies in solving the interfacial bonding problem caused by the differences in the thermophysical properties of materials in multilayer composite structures by precisely coordinating the characteristics of multilayer materials and hot-pressing process parameters. In the preparation of the wear-resistant layer, the coating thickness and drying temperature of each PU layer must be strictly controlled. Excessively thick coatings or excessively high drying temperatures can easily cause internal stress concentration and curling, while excessively thin coatings may lead to insufficient wear resistance. The addition of graphene aims to improve the coating's hardness and wear resistance by utilizing its two-dimensional sheet structure, but its content must be precisely balanced; excessive addition will cause agglomeration, which will weaken the interlayer bonding force and lead to a decrease in flexibility. The key to the preparation of the high- and low-temperature layer films is that the TPU high-temperature layer film must have a sufficiently high melting point to maintain morphological stability during subsequent hot pressing, while the TPU hot melt adhesive layer film needs to have a relatively low and defined melting point to achieve efficient bonding. The lamination process is the crucial step in the entire method. After heating the TPU high-temperature film to 155-175℃, it is applied to the PU surface wear-resistant layer in an extremely short time of 0.5-3 seconds. This operation utilizes the heat of the TPU high-temperature film to instantly soften the PU surface it contacts, promoting molecular chain diffusion and entanglement. Simultaneously, the superimposed pressure ensures tight interfacial contact. At this time, the TPU hot melt adhesive film layered on the other side can activate itself through heat conduction, raising its interface temperature above its melting point, thus achieving adhesion with the TPU high-temperature film in a single pressure step. In other words, a sequential stacked structure is formed: PU surface wear-resistant layer - second PU intermediate wear-resistant layer - first PU intermediate wear-resistant layer - PU contact layer - TPU high-temperature film - TPU hot melt adhesive film. The high-temperature instantaneous pressing strategy of the TPU high-temperature film prevents excessive heat diffusion into the heat-sensitive PU wear-resistant layer, preventing thermal oxidation or embrittlement. The subsequent forced cooling is used to quickly solidify the newly formed interfacial structure and lock in the bonding strength. The success of the entire process depends on the precise realization of the functions of each component and the strict matching of process parameters. Any deviation of parameters in any step, such as excessive hot pressing time, temperature exceeding the window, or untimely cooling, may cause poor interlayer adhesion, thermal damage to materials, or product deformation.

[0010] Preferably, the PU contact layer is prepared by mixing 70-90 parts by weight of polyurethane resin, 5-15 parts by weight of organic solvent and 1-5 parts by weight of crosslinking agent to form a slurry, controlling the wet film thickness to be 50-150 μm, and drying at 60-100℃ for 3-10 min to form the slurry.

[0011] Preferably, the organic solvent is one or a mixture of N,N-dimethylformamide, butanone, and toluene; the crosslinking agent is at least one of isocyanate trimer, hydrogenated phenyl dimethyl diisocyanate, or aziridine compound.

[0012] The composition ratio and process parameters of the PU contact layer together determine its key performance as an interfacial transition layer. Polyurethane resin, as the film-forming matrix, requires 70-90 parts by weight to ensure coating continuity and basic adhesion. Below this range, the film may be incomplete; above this range, excessive resin may reduce flexibility. Organic solvents are used to adjust the slurry viscosity for uniform coating. Their dosage must ensure good slurry leveling; excessive solvents will prolong drying time and increase the risk of residual bubbles, while insufficient solvents will lead to coating difficulties. Selected solvents such as N,N-dimethylformamide, butanone, and toluene have good solubility for polyurethane and can form stable solution systems. The addition of crosslinking agents is crucial to this layer design. Through chemical crosslinking reactions, they enhance the coating's cohesive strength and its bonding ability with subsequent TPU layers. Crosslinking agents such as isocyanate trimers can react with the active groups of polyurethane resin to form a three-dimensional network structure. Insufficient dosage will result in insufficient crosslinking density, reducing solvent resistance and interlayer adhesion; excessive dosage may lead to coating embrittlement. Maintaining the wet film thickness within the range of 50-150μm is crucial for balancing coating uniformity and production efficiency. Too thin a film can lead to missed areas, while too thick a film can result in surface drying but incomplete drying or cracking. A drying temperature of 60-100℃ paired with a drying time of 3-10 minutes ensures sufficient solvent evaporation while preventing premature reaction of the crosslinking agent or resin degradation due to excessively high temperatures. Too low a temperature or too short a time can leave solvent residue, affecting subsequent lamination.

[0013] Preferably, the first PU intermediate wear-resistant layer is prepared by mixing 60-80 parts by weight of polyurethane resin, 15-30 parts by weight of organic solvent and 5-15 parts by weight of graphene wear-resistant material to form a slurry, which is then coated onto the second PU intermediate wear-resistant layer, with the wet film thickness controlled at 80-200 μm, and dried at 70-110℃ for 5-15 min to form the slurry.

[0014] Polyurethane resin, as the continuous phase, at a concentration of 60-80 parts by mass, ensures coating formability while providing an effective stress transfer matrix for graphene. The organic solvent, at a concentration of 15-30 parts by mass, requires precise control of the slurry's rheological properties. Excessive amounts will lead to excessive volume shrinkage during drying, causing internal stress; insufficient amounts will result in poor graphene dispersion and agglomeration. 5-15 parts by mass of graphene, as the key reinforcing phase, forms physical cross-linking points in the polymer matrix through its two-dimensional sheet structure. When the content is below a threshold, the wear-resistant reinforcement effect is not significant; exceeding the critical value will not only cause re-agglomeration due to van der Waals forces but also hinder polymer chain movement, leading to material embrittlement. The wet film thickness is set at 80-200 μm based on a balance between functionality and processability. Too thin a film makes it difficult to fully construct the graphene reinforcing network; too thick a film easily leads to a skin effect during drying, causing internal defects. A gradient heating and drying strategy of 70-110℃ combined with a drying time of 5-15 minutes ensures that the solvent escapes in a stepwise manner to avoid pinholes, and also utilizes the temperature field to promote the orientation of graphene along the film thickness direction. It is particularly important to note that the matching of the thermal expansion coefficients of this layer, which serves as the wear-resistant host layer, with the underlying contact layer is crucial. Excessively rapid heating rates or excessively high drying temperatures can induce interlayer stress, manifesting as interfacial delamination in subsequent hot-pressing processes.

[0015] Preferably, the second PU intermediate wear-resistant layer and the PU surface wear-resistant layer are prepared by the following method: using a slurry containing 60-80 parts by weight of polyurethane resin, 10-25 parts by weight of organic solvent, 5-15 parts by weight of graphene wear-resistant material and 1-5 parts by weight of color paste or color powder, and coating and drying them sequentially: first coating the PU surface wear-resistant layer on the release paper, and then coating the second PU intermediate wear-resistant layer on the PU surface wear-resistant layer.

[0016] The wet film thickness of the second PU intermediate wear-resistant layer is 80-200 μm, and the wet film thickness of the PU surface wear-resistant layer is 50-150 μm. The drying temperature for both is 70-110℃, and the drying time for both is 5-15 min.

[0017] The second PU intermediate wear-resistant layer and the PU top layer adopt a strategy of using a unified slurry system but with differentiated thickness design, achieving a synergistic effect of functional gradient distribution and interfacial stress buffering. 60-80 parts by mass of polyurethane resin, forming a continuous phase, provide the basic mechanical properties of the system, balancing film-forming properties and flexibility requirements. 10-25 parts by mass of organic solvent, while ensuring slurry leveling, influence the suspension stability of graphene through viscosity control; excessive amounts lead to excessive volume shrinkage during drying, causing microcracks, while insufficient amounts result in uneven coating. 5-15 parts by mass of graphene form a gradient reinforcement network in both layers. When distributed closer to the surface in the top layer, it fully utilizes its ultra-hard properties to resist wear, while in the intermediate layer, it mainly serves to disperse stress. The differential thickness architecture (80-200 μm for the second PU intermediate layer and 50-150 μm for the PU top layer) ensures the overall wear-resistant layer thickness while reducing interfacial shear stress through the thinning design of the top layer, thus guaranteeing drying performance. The thinner PU top layer allows for a denser distribution of the graphene reinforcement phase at the friction interface, while avoiding flexibility degradation due to excessive thickness. The appropriately thickened second PU intermediate layer provides a supporting substrate for the top layer and accommodates the three-dimensional graphene network structure with ample thickness. A uniform drying temperature of 70-110℃ and a drying time of 5-15 minutes ensure that both layers form a compatible thermal history during drying, preventing interlayer delamination caused by differences in thermal shrinkage. Specifically, the thinner PU top layer design allows it to reach thermal equilibrium more quickly during the subsequent 155-175℃ hot pressing process, reducing high-temperature exposure time, while the thicker second PU intermediate layer buffers the transfer of hot-pressing stress to the contact layer. This gradient structure, combining consistent material composition with varying thickness, achieves a balance between surface wear resistance and reliable interlayer bonding while maintaining overall integrity.

[0018] Preferably, the graphene wear-resistant material is graphene powder modified with a silane coupling agent, with a sheet diameter of 1-20 μm and a specific surface area of ​​100-300 m². 2 / g; the pigment or colorant is at least one of phthalocyanine blue, carbon black, titanium dioxide or iron oxide red.

[0019] Preferably, the TPU high-temperature layer film is prepared by casting thermoplastic polyurethane particles with a melt index of 10-50 g / 10min and a hardness of 80A-95A into a film with a thickness of 0.1-0.2 mm at a processing temperature of 160-200℃.

[0020] The TPU high-temperature layer film, serving as the rigid support in the multilayer composite structure, has its material parameters and process settings directly determining the structural stability and hot-pressing adaptability of the composite film. TPU particles with a melt index of 10-50 g / 10min exhibit suitable melt strength during casting, ensuring film layer forming stability while avoiding thickness control failure due to excessive fluidity. A hardness range of 80A-95A provides this layer with necessary resistance to compressive deformation, and its modulus falls between that of a flexible wear-resistant layer and a rigid substrate, effectively buffering stress concentration during use. A processing temperature window of 160-200℃ ensures full plasticization of the TPU while preventing thermal degradation. This temperature range forms a gradient with the subsequent hot-pressing temperature of 155-175℃ in the lamination process, ensuring the high-temperature layer film maintains dimensional stability during the lamination process.

[0021] The 0.1-0.2 mm film thickness produced by casting is crucial for achieving a balance of multiple functions: too thin (<0.1 mm) will result in insufficient support, leading to localized collapse under hot pressing pressure; too thick (>0.2 mm) will significantly reduce overall flexibility and prolong heat conduction time during hot pressing, increasing the risk of thermal damage to the wear-resistant layer. This thickness design also considers thermal management requirements; the thinner geometry allows the film to quickly reach thermal equilibrium during hot pressing and achieves efficient heat dissipation in the subsequent forced cooling stage. Particularly noteworthy is the instantaneous heat buffering role of this TPU high-temperature layer film in the composite structure—when the 155-175℃ film contacts the PU surface layer, its moderate heat capacity and thermal conductivity allow the PU surface to reach its activation temperature while preventing heat diffusion into deeper layers. This thermal regulation function is the core physical basis for achieving instantaneous hot pressing in 0.5-3 seconds.

[0022] Preferably, the TPU hot melt adhesive film is prepared by casting thermoplastic polyurethane hot melt adhesive particles with a melting point of 110-130℃ into a film with a thickness of 0.02-0.1 mm at a processing temperature of 120-150℃.

[0023] As the bonding medium between the composite film and the substrate, the thermodynamic parameters and geometric characteristics of the TPU hot melt adhesive layer film jointly determine the reliability of the interfacial bonding. Thermoplastic polyurethane hot melt adhesive particles with a melting point of 110-130℃ have distinct thermal response characteristics. Their upper melting temperature is lower than the lower processing temperature of the TPU high-temperature layer film. This temperature difference design ensures that the heat from the high-temperature layer film can be effectively conducted to the hot melt adhesive layer during lamination, achieving interfacial fusion. The casting processing temperature setting of 120-150℃ follows the principle of minimum processing temperature, ensuring film forming quality while avoiding molecular chain degradation due to excessive heating. This temperature range is only 10-20℃ higher than the melting point, effectively controlling the rate of melt viscosity increase and providing the necessary processing window for the casting process. The film thickness design of 0.02-0.1 mm reflects a balance between adhesive function and process requirements. When the thickness is less than 0.02 mm, the adhesive layer cannot completely cover the microscopic unevenness of the substrate surface, resulting in insufficient adhesive strength; exceeding 0.1 mm will cause adhesive overflow and increase thermal resistance, slowing down the interfacial fusion speed. During the lamination process, this thickness, combined with a hot-pressing temperature of 155-175℃, allows the hot melt adhesive layer to complete the entire process of melting, wetting, and bonding within 0.5-3 seconds. Its thin structure ensures that heat can quickly penetrate the entire thickness of the adhesive layer for uniform activation. It is particularly noteworthy that the hot melt adhesive layer and the high-temperature film form a temperature gradient system during lamination. The high-temperature film acts as a heat source, using heat conduction to bring the hot melt adhesive layer to its activation temperature. This instantaneous thermal effect does not cause the hot melt adhesive to overheat and oxidize.

[0024] Preferably, during the preparation of the wear-resistant layer, the release paper undergoes corona treatment before coating, with a treatment power of 1-5 kW and a treatment speed of 5-20 m / min; and when coating the first PU intermediate wear-resistant layer, the second PU intermediate wear-resistant layer, and the PU surface wear-resistant layer, 0.1-1 parts by weight of polyether-modified polysiloxane leveling agent and 0.1-1 parts by weight of polyether-modified silicone defoamer are added to the slurry used.

[0025] Preferably, in the lamination and composite step, the forced cooling is achieved by a cooling roller, and the surface temperature of the cooling roller is controlled at 10-25℃.

[0026] Compared with the prior art, the present invention has the following advantages:

[0027] 1. By using the heat from the high-temperature TPU film as the heat source for hot pressing, the contradiction of inconsistent temperature requirements of each film layer is resolved, thus improving the overall performance.

[0028] 2. By stacking the PU surface wear-resistant layer, the second PU intermediate wear-resistant layer, the first PU intermediate wear-resistant layer, the PU contact layer, the TPU high-temperature film, and the TPU hot melt adhesive film in sequence, the functions of each layer are coordinated, and the overall performance is improved. Detailed Implementation

[0029] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. 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.

[0030] General Implementation Examples

[0031] A method for preparing a high-wear-resistant high- and low-temperature film includes the following steps:

[0032] Preparation of wear-resistant layer: The corresponding slurry containing 0.1-1 parts by weight of polyether modified polysiloxane leveling agent and 0.1-1 parts by weight of polyether modified silicone defoamer is sequentially coated on the release paper. The PU surface wear-resistant layer, the second PU intermediate wear-resistant layer, the first PU intermediate wear-resistant layer and the PU contact layer are dried to obtain the wear-resistant layer.

[0033] In some preferred embodiments, the release paper is subjected to corona treatment before coating, with a treatment power of 1-5 kW and a treatment speed of 5-20 m / min.

[0034] High and low temperature film preparation: TPU high temperature film and TPU hot melt adhesive film were prepared by casting method.

[0035] Lamination: The TPU high-temperature film is heated to 155-175℃, and then applied to the PU contact layer of the wear-resistant layer within 0.5-3 seconds. At the same time, the TPU hot melt adhesive film is stacked on the other side of the TPU high-temperature film, and hot-pressed at a pressure of 5-15 MPa. After pressing, forced cooling is performed immediately, and finally the release paper is peeled off to obtain the finished product.

[0036] In some preferred embodiments, the PU contact layer is prepared by mixing 70-90 parts by weight of polyurethane resin, 5-15 parts by weight of organic solvent and 1-5 parts by weight of crosslinking agent to form a slurry, controlling the wet film thickness to be 50-150 μm, and drying at 60-100°C for 3-10 min to form the slurry.

[0037] The organic solvent is one or a mixture of N,N-dimethylformamide, butanone, and toluene; the crosslinking agent is at least one of isocyanate trimer, hydrogenated phenyl dimethyl diisocyanate, or aziridine compound.

[0038] In some preferred embodiments, the first PU intermediate wear-resistant layer is prepared by mixing 60-80 parts by weight of polyurethane resin, 15-30 parts by weight of organic solvent and 5-15 parts by weight of graphene wear-resistant material to form a slurry, coating it on the second PU intermediate wear-resistant layer, controlling the wet film thickness to be 80-200 μm, and drying it at 70-110°C for 5-15 min to form the layer.

[0039] In some preferred embodiments, the second PU intermediate wear-resistant layer and the PU surface wear-resistant layer are prepared by sequentially coating and drying a slurry containing 60-80 parts by weight of polyurethane resin, 10-25 parts by weight of organic solvent, 5-15 parts by weight of graphene wear-resistant material, and 1-5 parts by weight of color paste or color powder.

[0040] The wet film thickness of the second PU intermediate wear-resistant layer is 80-200 μm, and the wet film thickness of the PU surface wear-resistant layer is 50-150 μm. The drying temperature for both is 70-110℃, and the drying time for both is 5-15 min.

[0041] The preparation process of graphene wear-resistant material is as follows: Graphene sheets with a diameter of 12 μm and a specific surface area of ​​200 m² are prepared. 2 / g of raw graphene powder was placed in a vacuum drying oven and pretreated at 80℃ for 2 hours to remove adsorbed moisture. Then, 10 parts by mass of the pretreated graphene powder were slowly added to a mixed solvent of 80 parts by mass of anhydrous ethanol and 20 parts by mass of deionized water, and dispersed in an 800W ultrasonic cell disruptor for 30 minutes to form a uniform suspension. After adjusting the pH of the suspension to 4.5 with acetic acid, 5 parts by mass of silane coupling agent KH-550 were pre-hydrolyzed in 15 parts by mass of ethanol aqueous solution and slowly added to the graphene suspension at a rate of 1 drop per second under mechanical stirring. The reaction system temperature was maintained at 60℃ and stirred continuously at 400 rpm for 4 hours to complete the grafting modification. After the reaction, the solid product was collected by a vacuum filtration device, and washed three times each with anhydrous ethanol and deionized water to remove unreacted coupling agent. Finally, the filter cake was dried in a vacuum drying oven at 80℃ for 12 hours.

[0042] The color paste or color powder is at least one of phthalocyanine blue, carbon black, titanium dioxide, or iron oxide red.

[0043] In some preferred embodiments, the TPU high-temperature layer film is prepared by casting thermoplastic polyurethane particles with a melt index of 10-50 g / 10min and a hardness of 80A-95A into a film with a thickness of 0.1-0.2 mm at a processing temperature of 160-200℃.

[0044] In some preferred embodiments, the TPU hot melt adhesive film is prepared by casting thermoplastic polyurethane hot melt adhesive particles with a melting point of 110-130℃ into a film with a thickness of 0.02-0.1 mm at a processing temperature of 120-150℃.

[0045] In some preferred embodiments, in the lamination process, the forced cooling is achieved by a cooling roller, and the surface temperature of the cooling roller is controlled at 10-25°C. Example 1

[0046] A method for preparing a high-wear-resistant high- and low-temperature film includes the following steps:

[0047] Preparation of the wear-resistant layer: The corresponding slurries for each layer are sequentially coated onto the release paper. The PU surface wear-resistant layer, the second PU intermediate wear-resistant layer, the first PU intermediate wear-resistant layer, and the PU contact layer are then dried to obtain the wear-resistant layer. The release paper undergoes corona treatment before coating; the treatment power is 3 kW, and the treatment speed is 12 m / min. The second PU intermediate wear-resistant layer and the PU surface wear-resistant layer are prepared as follows: A slurry containing 70 parts by weight of polyurethane resin, 18 parts by weight of toluene, 10 parts by weight of graphene wear-resistant material, 3 parts by weight of carbon black, 0.5 parts by weight of polyether-modified polysiloxane leveling agent, and 0.5 parts by weight of polyether-modified silicone defoamer is sequentially coated and dried. The wet film thickness of the second PU intermediate wear-resistant layer is 140 μm, and the wet film thickness of the PU surface wear-resistant layer is 100 μm. The drying temperature for both is 90℃, and the drying time for both is 10 minutes. The first PU intermediate wear-resistant layer is prepared by mixing 70 parts by weight of polyurethane resin, 22 parts by weight of methyl ethyl ketone (MEK), 10 parts by weight of graphene wear-resistant material, 0.5 parts by weight of polyether-modified polysiloxane leveling agent, and 0.5 parts by weight of polyether-modified silicone defoamer to form a slurry, which is then coated onto the second PU intermediate wear-resistant layer. The wet film thickness is controlled at 140 μm, and the mixture is dried at 90°C for 10 min to form the PU layer. The PU contact layer is prepared by mixing 80 parts by weight of polyurethane resin, 10 parts by weight of N,N-dimethylformamide, and 3 parts by weight of isocyanate trimer to form a slurry. The wet film thickness is controlled at 100 μm, and the mixture is dried at 80°C for 6 min to form the PU layer.

[0048] High and low temperature film preparation: TPU high-temperature film and TPU hot melt adhesive film were prepared by casting method. The TPU high-temperature film was prepared by casting thermoplastic polyurethane particles with a melt index of 30 g / 10min and a hardness of 88A at a processing temperature of 180℃ to form a film with a thickness of 0.15 mm. The TPU hot melt adhesive film was prepared by casting thermoplastic polyurethane hot melt adhesive particles with a melting point of 120℃ at a processing temperature of 135℃ to form a film with a thickness of 0.06 mm.

[0049] Lamination: The TPU high-temperature film is heated to 165℃ and then applied to the PU contact layer of the wear-resistant layer within 1.5 seconds. At the same time, the TPU hot melt adhesive film is superimposed on the other side of the TPU high-temperature film. Hot pressing is performed at a pressure of 10 MPa. After pressing, the film is forcibly cooled by a cooling roller with the surface temperature of the cooling roller controlled at 18℃. Finally, the release paper is peeled off to obtain the finished product. Example 2

[0050] A method for preparing a high-wear-resistant high- and low-temperature film includes the following steps:

[0051] Preparation of the wear-resistant layer: The corresponding slurries for each layer are sequentially coated onto the release paper. The PU surface wear-resistant layer, PU contact layer, second PU intermediate wear-resistant layer, first PU intermediate wear-resistant layer, and PU contact layer are then dried to obtain the wear-resistant layer. The release paper undergoes corona treatment before coating; the treatment power is 1 kW, and the treatment speed is 5 m / min. The second PU intermediate wear-resistant layer and the PU surface wear-resistant layer are prepared as follows: A slurry containing 60 parts by weight of polyurethane resin, 10 parts by weight of toluene, 5 parts by weight of graphene wear-resistant material, 1 part by weight of titanium dioxide, 0.1 parts by weight of polyether-modified polysiloxane leveling agent, and 0.1 parts by weight of polyether-modified silicone defoamer is sequentially coated and dried. The wet film thickness of the second PU intermediate wear-resistant layer is 80 μm, and the wet film thickness of the PU surface wear-resistant layer is 50 μm. The drying temperature for both is 70℃, and the drying time for both is 15 minutes. The first PU intermediate wear-resistant layer is prepared by mixing 60 parts by weight of polyurethane resin, 15 parts by weight of N,N-dimethylformamide, 5 parts by weight of graphene wear-resistant material, 0.1 parts by weight of polyether-modified polysiloxane leveling agent, and 0.1 parts by weight of polyether-modified silicone defoamer to form a slurry, which is then coated onto the second PU intermediate wear-resistant layer. The wet film thickness is controlled at 80 μm, and the mixture is dried at 70°C for 15 min to form the PU layer. The PU contact layer is prepared by mixing 70 parts by weight of polyurethane resin, 5 parts by weight of methyl ethyl ketone (MEK), and 1 part by weight of hydrogenated dimethyl phthalate (HMD) to form a slurry. The wet film thickness is controlled at 50 μm, and the mixture is dried at 60°C for 10 min to form the PU layer.

[0052] High and low temperature film preparation: TPU high temperature film and TPU hot melt adhesive film were prepared by casting method. The TPU high temperature film was prepared by casting thermoplastic polyurethane particles with a melt index of 10 g / 10 min and a hardness of 80A at a processing temperature of 160℃ to form a film with a thickness of 0.10 mm. The TPU hot melt adhesive film was prepared by casting thermoplastic polyurethane hot melt adhesive particles with a melting point of 110℃ at a processing temperature of 120℃ to form a film with a thickness of 0.02 mm.

[0053] Lamination: The TPU high-temperature film is heated to 155℃ and then applied to the PU contact layer of the wear-resistant layer within 0.5 s. At the same time, the TPU hot melt adhesive film is superimposed on the other side of the TPU high-temperature film. Hot pressing is performed at a pressure of 5 MPa. After pressing, the film is forcibly cooled by a cooling roller, with the surface temperature of the cooling roller controlled at 10℃. Finally, the release paper is peeled off to obtain the finished product. Example 3

[0054] A method for preparing a high-wear-resistant high- and low-temperature film includes the following steps:

[0055] Preparation of the wear-resistant layer: The corresponding slurries for each layer are sequentially coated onto the release paper. The PU surface wear-resistant layer, the second PU intermediate wear-resistant layer, the first PU intermediate wear-resistant layer, and the PU contact layer are then dried to obtain the wear-resistant layer. The release paper undergoes corona treatment before coating; the treatment power is 5 kW, and the treatment speed is 20 m / min. The second PU intermediate wear-resistant layer and the PU surface wear-resistant layer are prepared as follows: A slurry containing 80 parts by weight of polyurethane resin, 25 parts by weight of N,N-dimethylformamide, 15 parts by weight of graphene wear-resistant material, 5 parts by weight of phthalocyanine blue, 1 part by weight of polyether-modified polysiloxane leveling agent, and 1 part by weight of polyether-modified silicone defoamer is sequentially coated and dried. The wet film thickness of the second PU intermediate wear-resistant layer is 200 μm, and the wet film thickness of the PU surface wear-resistant layer is 150 μm. The drying temperature for both is 110℃, and the drying time for both is 5 minutes. The first PU intermediate wear-resistant layer is prepared by mixing 80 parts by weight of polyurethane resin, 30 parts by weight of methyl ethyl ketone (MEK), 15 parts by weight of graphene wear-resistant material, 1 part by weight of polyether-modified polysiloxane leveling agent, and 1 part by weight of polyether-modified silicone defoamer to form a slurry, which is then coated onto the second PU intermediate wear-resistant layer. The wet film thickness is controlled at 200 μm, and the mixture is dried at 110°C for 5 min to form the PU layer. The PU contact layer is prepared by mixing 90 parts by weight of polyurethane resin, 15 parts by weight of toluene, and 5 parts by weight of aziridine compound to form a slurry. The wet film thickness is controlled at 150 μm, and the mixture is dried at 100°C for 3 min to form the PU layer.

[0056] High and low temperature film preparation: TPU high-temperature film and TPU hot melt adhesive film were prepared by casting method. The TPU high-temperature film was prepared by casting thermoplastic polyurethane particles with a melt index of 50 g / 10min and a hardness of 95A at a processing temperature of 200℃ to form a film with a thickness of 0.2 mm. The TPU hot melt adhesive film was prepared by casting thermoplastic polyurethane hot melt adhesive particles with a melting point of 130℃ at a processing temperature of 150℃ to form a film with a thickness of 0.1 mm.

[0057] Lamination: The TPU high-temperature film is heated to 175°C and then applied to the PU contact layer of the wear-resistant layer within 3 seconds. At the same time, the TPU hot melt adhesive film is superimposed on the other side of the TPU high-temperature film. Hot pressing is performed at a pressure of 15 MPa. After pressing, the film is forcibly cooled by a cooling roller, with the surface temperature of the cooling roller controlled at 25°C. Finally, the release paper is peeled off to obtain the finished product. Example 4

[0058] A method for preparing a high-wear-resistant high- and low-temperature film includes the following steps:

[0059] Preparation of the wear-resistant layer: The corresponding slurries for each layer are sequentially coated onto the release paper. The PU surface wear-resistant layer, the second PU intermediate wear-resistant layer, the first PU intermediate wear-resistant layer, and the PU contact layer are then dried to obtain the wear-resistant layer. The release paper undergoes corona treatment before coating; the treatment power is 2 kW, and the treatment speed is 8 m / min. The second PU intermediate wear-resistant layer and the PU surface wear-resistant layer are prepared as follows: A slurry containing 65 parts by mass of polyurethane resin, 15 parts by mass of toluene, 8 parts by mass of graphene wear-resistant material, 2 parts by mass of iron oxide red, 0.3 parts by mass of polyether-modified polysiloxane leveling agent, and 0.7 parts by mass of polyether-modified silicone defoamer is sequentially coated and dried. The wet film thickness of the second PU intermediate wear-resistant layer is 120 μm, and the wet film thickness of the PU surface wear-resistant layer is 80 μm. The drying temperature for both is 80℃, and the drying time for both is 12 minutes. The first PU intermediate wear-resistant layer is prepared by mixing 65 parts by weight of polyurethane resin, 20 parts by weight of methyl ethyl ketone (MEK), 8 parts by weight of graphene wear-resistant material, 0.3 parts by weight of polyether-modified polysiloxane leveling agent, and 0.7 parts by weight of polyether-modified silicone defoamer to form a slurry, which is then coated onto the second PU intermediate wear-resistant layer. The wet film thickness is controlled at 120 μm, and the mixture is dried at 80°C for 12 min to form the PU layer. The PU contact layer is prepared by mixing 75 parts by weight of polyurethane resin, 8 parts by weight of N,N-dimethylformamide mixed with toluene solvent, and 2 parts by weight of isocyanate trimer to form a slurry. The wet film thickness is controlled at 80 μm, and the mixture is dried at 70°C for 8 min to form the PU layer.

[0060] High and low temperature film preparation: TPU high-temperature film and TPU hot melt adhesive film were prepared by casting method. The TPU high-temperature film was prepared by casting thermoplastic polyurethane particles with a melt index of 20 g / 10min and a hardness of 85A at a processing temperature of 170℃ to form a film with a thickness of 0.12 mm. The TPU hot melt adhesive film was prepared by casting thermoplastic polyurethane hot melt adhesive particles with a melting point of 115℃ at a processing temperature of 130℃ to form a film with a thickness of 0.04 mm.

[0061] Lamination: The TPU high-temperature film is heated to 160°C and then applied to the PU contact layer of the wear-resistant layer within 1 second. At the same time, the TPU hot melt adhesive film is superimposed on the other side of the TPU high-temperature film. Hot pressing is performed at a pressure of 8 MPa. After pressing, the film is forcibly cooled by a cooling roller with the surface temperature of the cooling roller controlled at 15°C. Finally, the release paper is peeled off to obtain the finished product. Example 5

[0062] A method for preparing a high-wear-resistant high- and low-temperature film includes the following steps:

[0063] Preparation of the wear-resistant layer: The corresponding slurries for each layer are sequentially coated onto the release paper. The PU surface wear-resistant layer, the second PU intermediate wear-resistant layer, the first PU intermediate wear-resistant layer, and the PU contact layer are then dried to obtain the wear-resistant layer. The release paper undergoes corona treatment before coating; the treatment power is 4 kW, and the treatment speed is 18 m / min. The second PU intermediate wear-resistant layer and the PU surface wear-resistant layer are prepared as follows: A slurry containing 75 parts by weight of polyurethane resin, 20 parts by weight of N,N-dimethylformamide, 12 parts by weight of graphene wear-resistant material, 4 parts by weight of carbon black, 0.8 parts by weight of polyether-modified polysiloxane leveling agent, and 0.2 parts by weight of polyether-modified silicone defoamer is sequentially coated and dried. The wet film thickness of the second PU intermediate wear-resistant layer is 180 μm, and the wet film thickness of the PU surface wear-resistant layer is 120 μm. The drying temperature for both is 100℃, and the drying time for both is 8 hours. The first PU intermediate wear-resistant layer is prepared by mixing 75 parts by weight of polyurethane resin, 25 parts by weight of N,N-dimethylformamide, 12 parts by weight of graphene wear-resistant material, 0.8 parts by weight of polyether-modified polysiloxane leveling agent, and 0.2 parts by weight of polyether-modified silicone defoamer to form a slurry, which is then coated onto the second PU intermediate wear-resistant layer. The wet film thickness is controlled at 180 μm, and the mixture is dried at 100°C for 8 min to form the PU contact layer. The PU contact layer is prepared by mixing 85 parts by weight of polyurethane resin, 12 parts by weight of a mixed solvent of butanone and toluene, and 4 parts by weight of hydrogenated dimethyl phthalate to form a slurry. The wet film thickness is controlled at 120 μm, and the mixture is dried at 90°C for 4 min to form the PU contact layer.

[0064] High and low temperature film preparation: TPU high temperature film and TPU hot melt adhesive film were prepared by casting method. The TPU high temperature film was prepared by casting thermoplastic polyurethane particles with a melt index of 40 g / 10min and a hardness of 92A at a processing temperature of 190℃ to form a film with a thickness of 0.18 mm. The TPU hot melt adhesive film was prepared by casting thermoplastic polyurethane hot melt adhesive particles with a melting point of 125℃ at a processing temperature of 140℃ to form a film with a thickness of 0.08 mm.

[0065] Lamination: The TPU high-temperature film is heated to 170°C and then applied to the PU contact layer of the wear-resistant layer within 2 seconds. At the same time, the TPU hot melt adhesive film is superimposed on the other side of the TPU high-temperature film. Hot pressing is performed at a pressure of 12 MPa. After pressing, the film is forcibly cooled by a cooling roller, with the surface temperature of the cooling roller controlled at 22°C. Finally, the release paper is peeled off to obtain the finished product.

[0066] Comparative Example 1

[0067] The only difference from Example 1 is that it only has a TPU high-temperature layer film and a TPU hot melt adhesive layer film.

[0068] Comparative Example 2

[0069] The only difference from Example 1 is that the wear-resistant layer, the TPU high-temperature layer film, and the TPU hot melt adhesive layer film are composited by hot pressing at a temperature of 160°C.

[0070] Comparative Example 3

[0071] The only difference from Example 1 is that no graphene wear-resistant material is added to the wear-resistant layer.

[0072] Comparative Example 4

[0073] The only difference from Example 1 is that graphene wear-resistant material is added only to the first PU intermediate wear-resistant layer.

[0074] Comparative Example 5

[0075] The only difference from Example 1 is that graphene wear-resistant material is added only to the second PU intermediate wear-resistant layer.

[0076] Comparative Example 6

[0077] The only difference from Example 1 is that the TPU high-temperature layer film thickness is 0.25 mm.

[0078] Comparative Example 7

[0079] The only difference from Example 1 is that the TPU high-temperature layer film thickness is 0.08 mm.

[0080] Comparative Example 8

[0081] The only difference from Example 1 is that the TPU high-temperature layer film is heated to 165°C and then applied to the PU contact layer of the abrasion-resistant layer within 3.5 seconds.

[0082] Comparative Example 9

[0083] The only difference from Example 1 is that the lamination is cooled in air.

[0084] Comparative Example 10

[0085] The only difference from Example 1 is that there is no second PU intermediate wear-resistant layer, only a PU surface wear-resistant layer with a thickness of 240μm, which is the same as the total thickness of the second PU intermediate wear-resistant layer and the PU surface wear-resistant layer in Example 1.

[0086] Performance testing:

[0087] Abrasion resistance: Abrasion resistance was tested according to GB / T 1768-2006 "Test of Abrasion Resistance of Paints and Varnishes - Rotary Rubber Grinding Wheel Method";

[0088] Tensile strength test: Measured according to GB / T 528-2009 standard;

[0089] Peel strength: Tested according to GB / T 2791-1995 "Adhesives T - Peel strength test method - Flexible materials to flexible materials";

[0090] Heat resistance: Tested according to GB / T 7141-2008 "Plastics Heat Aging Test Method", which refers to the retention rate of properties (such as tensile strength) after high temperature aging;

[0091] Dynamic flexural endurance: Tested according to GB / T 3903.41-2008 "Test methods for flexural endurance of footwear uppers, linings and insoles";

[0092] Slip resistance coefficient: Tested in accordance with GB / T 3903.6—2024 "Test Methods for Slip Resistance of Whole Footwear".

[0093] The performance test results are shown in Table 1.

[0094] Table 1 Test Results of Examples and Comparative Examples

[0095]

[0096] Existing TPU high and low temperature films face multiple bottlenecks in the application of functional layers in footwear materials: the high-filler modification used to improve abrasion resistance leads to a hard and brittle film, which is prone to cracking and detachment after being laminated with a soft foamed midsole due to modulus mismatch, while sacrificing anti-slip performance and comfort; the ultra-thin abrasion-resistant layer coated on the surface relies on physical adhesion, and is prone to peeling off from the base film under continuous impact, friction and temperature and humidity changes, resulting in unsustainable abrasion resistance; when multi-layered composites are used, the thermophysical properties of each functional layer are very different, and excessively high hot pressing temperature will damage the abrasion-resistant layer, while too low a temperature will result in weak interlayer bonding. The process window is narrow and difficult to control, and existing related patented technologies have not solved this temperature contradiction.

[0097] The embodiments demonstrate significant performance advantages through the construction of a complete multi-layered functional structure and precise process control. The core of this approach lies in the design of a gradient system of four PU wear-resistant layers (PU contact layer, first PU intermediate wear-resistant layer, second PU intermediate wear-resistant layer, and PU surface wear-resistant layer), coupled with graphene wear-resistant material modified with a silane coupling agent, uniformly dispersed within each PU wear-resistant layer. The two-dimensional sheet structure of graphene effectively enhances the material's hardness and wear resistance. Furthermore, by differentiating the amount of PU resin used, the coating thickness, and the drying process for each PU wear-resistant layer, both the compatibility of the interlayer structure and the functional division of transition, support, reinforcement, and surface protection are ensured, balancing the material's wear resistance and flexibility. Simultaneously, the embodiments also prepared a TPU high-temperature layer film and a TPU hot melt adhesive layer film with specific properties; the former serves as a support and thermal buffer layer. The latter, as a highly efficient adhesive layer, combined with an instantaneous hot-pressing process at 155-175℃ and a forced cooling process using cooling rollers at 10-25℃, ensures that the heat from the TPU high-temperature film only momentarily softens the surface of the PU wear-resistant layer to promote molecular chain diffusion and entanglement. This prevents heat from diffusing into the deeper layers of the PU wear-resistant layer, which could cause thermal oxidation or brittleness. Simultaneously, the TPU hot melt adhesive film reaches the melting temperature synchronously through heat conduction, achieving strong interlayer bonding. This solves the temperature contradiction caused by the differences in the thermophysical properties of each functional layer in existing multilayer composites. The performance exhibits a reasonable gradient change among the embodiments, which is essentially due to subtle differences in parameters such as the amount of graphene added, hot-pressing pressure and temperature, and drying temperature and time. Embodiments with a higher amount of graphene added and process parameters that better meet the needs of the functional layers of footwear materials exhibit superior wear resistance, tensile strength, and interlayer bonding.

[0098] Compared to the examples, Comparative Example 1, which only retains the TPU high-temperature layer and TPU hot melt adhesive layer, lacks the gradient structure of the four-layer PU abrasion-resistant layer and the graphene reinforcement system. It lacks both an effective structure to resist ground friction and ensure abrasion resistance, and a flexible transition layer to alleviate the modulus difference with the foamed midsole. Furthermore, it lacks the chemical cross-linking effect of the PU contact layer to strengthen interlayer bonding, resulting in comprehensive performance degradation. Comparative Example 2, although possessing a complete structure, still suffers from temperature mismatch issues due to the use of traditional hot-pressing composite technology. Comparative Example 3, lacking graphene abrasion-resistant material in its PU abrasion-resistant layer, loses the resistance to frictional wear and the enhancement of mechanical properties from its two-dimensional sheet structure. The material struggles to withstand continuous friction and bending stress, leading to poor abrasion resistance and tensile strength. The wear resistance and dynamic flexural strength decreased significantly. In Comparative Examples 4 and 5, graphene wear-resistant material was added only to a single layer of the first or second PU intermediate wear-resistant layer. The graphene was unevenly distributed in the PU wear-resistant layer. Either the surface layer lacked sufficient reinforcing phase to resist surface friction, or the intermediate layer lacked sufficient support to disperse bending stress. Ultimately, the wear resistance and dynamic flexural strength were inferior to those of the examples. In Comparative Example 6, the thickness of the TPU high-temperature layer exceeded the optimization range of the examples. The excessively thick layer not only reduced the overall structural flexibility, affecting the dynamic flexural strength, but also prolonged the heat conduction time, causing heat to diffuse into the deeper layers of the PU wear-resistant layer, resulting in thermal oxidation damage to the PU material and further weakening the flexural strength and heat resistance stability. In Comparative Example 7, the TPU high-temperature layer was too thick. The thinness and insufficient support of the TPU layer make it prone to local collapse during hot pressing. This results in poor interfacial contact between the TPU high-temperature layer, the PU surface wear-resistant layer, and the TPU hot melt adhesive layer, preventing sufficient molecular chain entanglement and fusion bonding. This leads to reduced interlayer peel strength, and the thin film's thermal buffering effect is weakened, affecting heat resistance. In Comparative Example 8, the hot pressing time exceeded the instantaneous range of the embodiment. The excessive heat caused heat to penetrate the buffering effect of the TPU high-temperature layer and diffuse into the deeper layers of the PU wear-resistant layer, triggering excessive thermal oxidation and cross-linking of the PU molecular chains. This resulted in material hardening and embrittlement, a decrease in tensile strength and dynamic flexural strength, and thermal damage also reduced the material's heat resistance stability. In Comparative Example 9, air cooling was used instead of the forced cooling roller of the embodiment, which could not achieve the desired effect. The rapid locking of the newly formed molecular chain entanglement structure between layers makes it easy for stress relaxation to occur between the layers. The difference in thermal shrinkage rate between the layers causes internal stress, resulting in a decrease in interlayer peel strength and a deterioration in dynamic flexural performance due to the presence of internal stress. Comparative Example 10 only retains the PU surface wear-resistant layer and lacks the second PU intermediate wear-resistant layer. This may have caused the stress buffering and reinforcement function originally undertaken by the second polyurethane intermediate wear-resistant layer to disappear. The modulus transition between the first polyurethane intermediate wear-resistant layer and the polyurethane surface wear-resistant layer is not continuous. It may also be due to the excessive thickness of the PU surface wear-resistant layer leading to incomplete drying. Ultimately, stress concentration is likely to occur, which cannot fully disperse bending stress and resist frictional loss. As a result, its tensile strength, wear resistance and dynamic flexural performance are significantly worse than those of the Example.

[0099] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A method for preparing a high-wear-resistant high- and low-temperature film, characterized in that, Includes the following steps: Abrasion-resistant layer preparation: Abrasion-resistant PU surface layer, abrasion-resistant PU intermediate layer, abrasion-resistant PU intermediate layer, and PU contact layer are sequentially coated and dried on release paper to obtain abrasion-resistant layer; High and low temperature single-layer prefabrication: TPU high-temperature layer film and TPU hot melt adhesive layer film are prepared by casting method; Lamination: The TPU high-temperature film is heated to 155-175℃, and then applied to the PU contact layer of the wear-resistant layer within 0.5-3 seconds. At the same time, the TPU hot melt adhesive film is stacked on the other side of the TPU high-temperature film, and hot-pressed at a pressure of 5-15 MPa. After pressing, forced cooling is performed immediately, and finally the release paper is peeled off to obtain the finished product. The second PU intermediate wear-resistant layer and the PU surface wear-resistant layer are prepared by the following method: using a slurry containing 60-80 parts by weight of polyurethane resin, 10-25 parts by weight of organic solvent, 5-15 parts by weight of graphene wear-resistant material and 1-5 parts by weight of color paste or color powder, which are sequentially coated and dried. The first PU intermediate wear-resistant layer is prepared by mixing 60-80 parts by weight of polyurethane resin, 15-30 parts by weight of organic solvent and 5-15 parts by weight of graphene wear-resistant material to form a slurry, which is then coated onto the second PU intermediate wear-resistant layer. The wet film thickness is controlled to be 80-200 μm, and the film is dried at 70-110℃ for 5-15 min to form the layer. The PU contact layer is prepared by mixing 70-90 parts by weight of polyurethane resin, 5-15 parts by weight of organic solvent and 1-5 parts by weight of crosslinking agent to form a slurry, controlling the wet film thickness to be 50-150 μm, and drying at 60-100℃ for 3-10 min to form the slurry. The forced cooling is achieved through a cooling roller, and the surface temperature of the cooling roller is controlled at 10-25℃.

2. The preparation method according to claim 1, characterized in that, The organic solvent is one or a mixture of N,N-dimethylformamide, butanone, and toluene; the crosslinking agent is at least one of isocyanate trimer, hydrogenated phenyl dimethyl diisocyanate, or aziridine compound.

3. The preparation method according to claim 1, characterized in that, The color paste or color powder is at least one of phthalocyanine blue, carbon black, titanium dioxide, or iron oxide red.

4. The preparation method according to claim 1, characterized in that, The wet film thickness of the second PU intermediate wear-resistant layer is 80-200 μm, and the wet film thickness of the PU surface wear-resistant layer is 50-150 μm. The drying temperature for both is 70-110℃, and the drying time for both is 5-15 min.

5. The preparation method according to claim 1, characterized in that, The graphene wear-resistant material is graphene powder modified with a silane coupling agent, with a sheet diameter of 1-20 μm and a specific surface area of ​​100-300 m². 2 / g.

6. The preparation method according to claim 1, characterized in that, The TPU high-temperature layer film is prepared by casting thermoplastic polyurethane particles with a melt index of 10-50 g / 10min and a hardness of 80A-95A at a processing temperature of 160-200℃ to form a film with a thickness of 0.1-0.2 mm.

7. The preparation method according to claim 1, characterized in that, The TPU hot melt adhesive film is prepared by casting thermoplastic polyurethane hot melt adhesive particles with a melting point of 110-130℃ into a film with a thickness of 0.02-0.1 mm at a processing temperature of 120-150℃.

8. The preparation method according to claim 1, characterized in that, During the preparation of the wear-resistant layer, the release paper undergoes corona treatment before coating, with a treatment power of 1-5 kW and a treatment speed of 5-20 m / min; and when coating the first PU intermediate wear-resistant layer, the second PU intermediate wear-resistant layer, and the PU surface wear-resistant layer, 0.1-1 parts by weight of polyether-modified polysiloxane leveling agent and 0.1-1 parts by weight of polyether-modified silicone defoamer are added to the slurry used.

9. A high-wear-resistant high- and low-temperature film, characterized in that, The material is prepared by the preparation method described in any one of claims 1-8, comprising a structure in which PU surface wear-resistant layer, second PU intermediate wear-resistant layer, first PU intermediate wear-resistant layer, PU contact layer, TPU high-temperature film, and TPU hot melt adhesive film are stacked sequentially.

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