INS high-temperature-resistant and scratch-resistant automobile decorative film and preparation method thereof

Abstract

The invention discloses an INS high-temperature-resistant and scratch-resistant automobile decorative film and a preparation method thereof, and belongs to the technical field of automobile decorative films, the INS high-temperature-resistant and scratch-resistant automobile decorative film sequentially comprises a substrate, a bonding layer, a gradient functional layer and a transparent layer; wherein the substrate adopts a polycarbonate base material, the bonding layer adopts a siloxane polymer layer, the gradient functional layer adopts a silane coupling agent layer and comprises a first functional layer, a second functional layer and a third functional layer, and the transparent layer adopts a high-crosslinking density hardness layer. The INS high-temperature-resistant and scratch-resistant automobile decorative film is prepared by adopting a multi-layer gradient structure design and combining an electric field induction preparation process, so that the high temperature resistance, the scratch resistance and the light transmission performance of the automobile decorative film are comprehensively improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of automobile decorative films, and in particular relates to an INS high-temperature-resistant and scratch-resistant automobile decorative film and a preparation method thereof. Background Art

[0002] As a key material for protecting and beautifying vehicle interiors, automotive decorative films have become a crucial component of the automotive aftermarket, driven by the rapid development of the automotive industry and rising consumer expectations for in-car environments. Traditional automotive decorative films primarily include polyurethane films, polyvinyl chloride films, and thermoplastic polyurethane (TPU) films, which have played a role in basic decoration and light protection. However, with the increasing prevalence of automotive electronic devices, the increasing complexity of in-car temperature environments, and increasing customer demands for product durability, traditional decorative film materials are no longer able to meet the stringent requirements of modern automotive applications.

[0003] Current automotive decorative film technology on the market faces numerous limitations, severely hindering its adoption in high-end automotive applications. First, regarding heat resistance, the glass transition temperature of traditional PU and PVC films typically ranges from 80-100°C. These films are prone to softening, deformation, blistering, and peeling in the summer heat. This is particularly true in areas directly exposed to sunlight, such as dashboards and door panels, where temperatures can reach over 70°C, making them difficult for traditional materials to withstand. Second, regarding scratch resistance, due to a lack of effective surface hardening technology, the surface hardness of existing decorative films is generally below 3H, making them susceptible to scratches and wear during daily use, impacting both aesthetics and service life. Summary of the Invention

[0004] The present invention discloses an INS high-temperature-resistant and scratch-resistant automobile decorative film and a preparation method thereof. The INS high-temperature-resistant and scratch-resistant automobile decorative film is prepared by adopting a multi-layer gradient structure design and combining it with an electric field induced preparation process. This achieves a comprehensive improvement in the high-temperature resistance, scratch resistance and light transmittance of the automobile decorative film, and solves the technical problem of insufficient high-temperature resistance and scratch resistance of automobile decorative films in the prior art.

[0005] The present invention protects an INS high-temperature-resistant and scratch-resistant automobile decorative film, which comprises a substrate, an adhesive layer, a gradient functional layer and a transparent layer in sequence; The substrate is a polycarbonate substrate; The adhesive layer is a silicone polymer layer; The gradient functional layer adopts a silane coupling agent layer, including a first functional layer, a second functional layer and a third functional layer; The transparent layer adopts a high cross-linking density hardness layer; The INS high-temperature-resistant and scratch-resistant automobile decorative film is prepared under nitrogen protection and electric field induction.

[0006] Furthermore, the specific parameters of the electric field induction are: the electric field strength is 2kV / cm when preparing the adhesive layer, the electric field strength is 3kV / cm when preparing the gradient functional layer, and the electric field strength is 5kV / cm when preparing the transparent layer. The electric field frequency is fixed at 5kHz, the waveform is a sine wave, indium tin oxide transparent electrodes are used, the electrode spacing is 500μm, and the electric field uniformity is ±2%.

[0007] Furthermore, the thickness of the adhesive layer is 15-20 μm, the thickness of the transparent layer is 8-10 μm, the thickness of the gradient functional layer is 15 μm, and the thickness ratio of the first functional layer, the second functional layer and the third functional layer is 1:1:1.

[0008] Furthermore, the adhesive layer comprises the following raw materials in parts by weight: 35-45 parts by weight of polydimethylsiloxane; 4-5 parts by weight of vinyltriethoxysilane; 0.1 parts by weight of DBTDL catalyst; 5 parts by weight of 4-cyano-4'-pentylbiphenyl; 3 parts by weight of N,N-dimethyl-4-aminoazobenzene.

[0009] Furthermore, the adhesive layer is prepared by the following method: polydimethylsiloxane, vinyltriethoxysilane, DBTDL catalyst, 4-cyano-4'-pentylbiphenyl and N,N-dimethyl-4-aminoazobenzene are mixed evenly, spin-coated on the substrate surface at 1500 rpm for 30 seconds, and cured at 50°C for 30 minutes to obtain an adhesive layer with a thickness of 15-20 μm.

[0010] Furthermore, the substrate is prepared by the following method: a polycarbonate substrate is cleaned with anhydrous ethanol, treated at room temperature for 10 minutes, treated with ultraviolet ozone for 5 minutes, and treated with oxygen plasma at a power of 100 W for 30 seconds to obtain the substrate.

[0011] Furthermore, the first functional layer comprises the following raw materials in parts by weight: 20 parts by weight of KH560, 5 parts by weight of TEOS, 5 parts by weight of 4-cyano-4'-pentylbiphenyl and 3 parts by weight of N,N-dimethyl-4-aminoazobenzene; The second functional layer comprises the following raw materials in parts by weight: 25 parts by weight of KH560, 10 parts by weight of TEOS, 5 parts by weight of 4-cyano-4'-pentylbiphenyl and 3 parts by weight of N,N-dimethyl-4-aminoazobenzene; The third functional layer includes the following raw materials in parts by weight: 30 parts by weight of KH560, 15 parts by weight of TEOS, 5 parts by weight of 4-cyano-4'-pentylbiphenyl and 3 parts by weight of N,N-dimethyl-4-aminoazobenzene.

[0012] Furthermore, the gradient functional layer is prepared by the following method: KH560, TEOS, 4-cyano-4'-pentylbiphenyl and N,N-dimethyl-4-aminoazobenzene were mixed evenly and cured at 60°C for 15 minutes on the surface of the adhesive layer to obtain a first functional layer; KH560, TEOS, 4-cyano-4'-pentylbiphenyl and N,N-dimethyl-4-aminoazobenzene were mixed evenly and cured at 80°C for 15 minutes on the surface of the first functional layer to obtain a second functional layer; KH560, TEOS, 4-cyano-4'-pentylbiphenyl and N,N-dimethyl-4-aminoazobenzene were mixed evenly and cured at 100°C for 15 minutes on the surface of the second functional layer to obtain a third functional layer, thereby completing the preparation of the gradient functional layer.

[0013] Furthermore, the transparent layer is prepared by the following method: 15 to 25 parts by weight of cage-type octaphenylsilsesquioxane, 8 to 12 parts by weight of triazine-based epoxy resin, 8 parts by weight of PETA curing agent, 5 parts by weight of 4-cyano-4'-pentylbiphenyl and 3 parts by weight of N,N-dimethyl-4-aminoazobenzene are mixed evenly, and then cured at 130° C. for 8 minutes on the surface of the gradient functional layer to obtain a transparent layer.

[0014] The present invention further protects a method for preparing the above-mentioned INS high-temperature-resistant and scratch-resistant automobile decorative film, which specifically includes the following steps: under nitrogen protection and electric field induction, preparing an adhesive layer on the surface of a substrate, preparing a gradient functional layer on the surface of the adhesive layer, and preparing a transparent layer on the surface of the gradient functional layer, thereby obtaining the INS high-temperature-resistant and scratch-resistant automobile decorative film.

[0015] The present invention has the following beneficial effects: (1) The present invention adopts a multi-layer gradient structure and, through an electric field induced preparation process, sequentially constructs an adhesive layer, a gradient functional layer and a transparent layer on the surface of a polycarbonate substrate. The gradient functional layer comprises three functional layers, forming a gradient distribution with progressive performance, effectively avoiding sudden stress changes between layers, and significantly improving the overall performance and service life of the film material.

[0016] (2) The present invention adds cage-type octaphenylsilsesquioxane to the transparent layer. Its unique cage-type molecular structure has excellent thermal stability and optical transparency, a thermal decomposition temperature of over 600°C, and a transparency of over 95%. At the same time, the addition of triazine-based epoxy resin further enhances the crosslinking density, greatly improves the surface hardness, and achieves significant high temperature resistance and scratch resistance.

[0017] (3) The gradient functional layer of the present invention forms a continuous change in cross-linking density and inorganic network strength through the gradient distribution of KH560 and TEOS content, which effectively alleviates the modulus difference between different layers, avoids interface brittle fracture, and improves the flexibility and impact resistance of the membrane material.

[0018] (4) The adhesive layer of the present invention adopts a polydimethylsiloxane system, which has excellent flexibility and low surface energy characteristics. The introduction of 4-cyano-4'-pentylbiphenyl liquid crystal molecules improves molecular orientation and interface compatibility. N,N-dimethyl-4-aminoazobenzene as a light stabilizer effectively prevents ultraviolet aging, ensuring the firm bonding and long-term stability of the film material and the substrate. (5) The present invention adopts electric field induced preparation technology to control the electric field intensity so that the molecules are arranged in an orderly manner under the action of the electric field, thereby improving the interaction between molecules and interface bonding, and enhancing the overall performance of the film material.

[0019] (6) The preparation process of the present invention is simple and efficient. It adopts spin coating technology combined with gradient temperature curing, which has a short curing time and high production efficiency. It is prepared under nitrogen protection, avoiding the influence of oxidation reaction and ensuring the stability and consistency of product quality.

[0020] (7) The INS high-temperature-resistant and scratch-resistant automotive decorative film of the present invention has excellent optical properties, high transparency, and does not affect the original decorative effect. It also has excellent weather resistance. According to experimental testing, the operating temperature range is -40°C to 150°C, the UV aging life is more than 10 years, the thermal expansion coefficient is less than 50ppm / °C, and the dimensional stability is good, which can meet the harsh use environment of automotive interior and exterior decoration.

[0021] (8) The automobile decorative film prepared by the present invention has high cost-effectiveness, stable raw material sources, mature and controllable preparation technology, is easy to mass-produce, has stable and reliable product performance, long service life, and low maintenance cost. It can effectively protect the surface of automobile interior from damage by high temperature and scratches, and improve the service life and aesthetics of automobile interior, and is worthy of promotion. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 This is a schematic structural diagram of the INS high-temperature-resistant and scratch-resistant automotive decorative film of the present invention.

[0023] Figure 2 The figure is a schematic diagram of the operation process in the preparation process of the INS high-temperature-resistant and scratch-resistant automobile decorative film of the present invention. DETAILED DESCRIPTION

[0024] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0025] like Figure 1 As shown, an INS high-temperature-resistant and scratch-resistant automotive decorative film comprises a substrate, an adhesive layer, a gradient functional layer and a transparent layer in sequence; The substrate is a polycarbonate substrate; The adhesive layer is a silicone polymer layer; The gradient functional layer adopts a silane coupling agent layer, including a first functional layer, a second functional layer and a third functional layer; The transparent layer adopts a high cross-linking density hardness layer; Furthermore, the thickness of the adhesive layer is 15-20 μm, the thickness of the transparent layer is 8-10 μm, the thickness of the gradient functional layer is 15 μm, and the thickness ratio of the first functional layer, the second functional layer and the third functional layer is 1:1:1.

[0026] The INS high-temperature-resistant and scratch-resistant automobile decorative film is prepared under nitrogen protection and electric field induction.

[0027] Furthermore, the specific parameters of the electric field induction are: the electric field strength is 2kV / cm when preparing the adhesive layer, the electric field strength is 3kV / cm when preparing the gradient functional layer, and the electric field strength is 5kV / cm when preparing the transparent layer. The electric field frequency is fixed at 5kHz, the waveform is a sine wave, indium tin oxide transparent electrodes are used, the electrode spacing is 500μm, and the electric field uniformity is ±2%.

[0028] like Figure 2 As shown, the specific operation of the INS high-temperature and scratch-resistant automotive decorative film is as follows: placing a substrate on the lower indium tin oxide transparent electrode, spin-coating an adhesive layer component on the substrate surface, covering the indium tin oxide soft film electrode as the upper electrode, and curing while applying an electric field. After curing is completed, the upper electrode is removed, and the first functional layer component, the second functional layer component, the third functional layer component and the transparent layer component are sequentially coated. After each layer of component is coated, a corresponding curing operation is performed and an electric field is applied simultaneously to obtain the INS high-temperature and scratch-resistant automotive decorative film.

[0029] Furthermore, the adhesive layer comprises the following raw materials in parts by weight: 35-45 parts by weight of polydimethylsiloxane; 4-5 parts by weight of vinyltriethoxysilane; 0.1 parts by weight of DBTDL catalyst; 5 parts by weight of 4-cyano-4'-pentylbiphenyl; 3 parts by weight of N,N-dimethyl-4-aminoazobenzene.

[0030] Furthermore, the adhesive layer is prepared by the following method: polydimethylsiloxane, vinyltriethoxysilane, DBTDL catalyst, 4-cyano-4'-pentylbiphenyl and N,N-dimethyl-4-aminoazobenzene are mixed evenly, spin-coated on the substrate surface at 1500 rpm for 30 seconds, and cured at 50°C for 30 minutes to obtain an adhesive layer with a thickness of 15-20 μm.

[0031] Furthermore, the substrate is prepared by the following method: a polycarbonate substrate is cleaned with anhydrous ethanol, treated at room temperature for 10 minutes, treated with ultraviolet ozone for 5 minutes, and treated with oxygen plasma at a power of 100 W for 30 seconds to obtain the substrate.

[0032] Furthermore, the first functional layer comprises the following raw materials in parts by weight: 20 parts by weight of KH560, 5 parts by weight of TEOS, 5 parts by weight of 4-cyano-4'-pentylbiphenyl and 3 parts by weight of N,N-dimethyl-4-aminoazobenzene; The second functional layer comprises the following raw materials in parts by weight: 25 parts by weight of KH560, 10 parts by weight of TEOS, 5 parts by weight of 4-cyano-4'-pentylbiphenyl and 3 parts by weight of N,N-dimethyl-4-aminoazobenzene; The third functional layer includes the following raw materials in parts by weight: 30 parts by weight of KH560, 15 parts by weight of TEOS, 5 parts by weight of 4-cyano-4'-pentylbiphenyl and 3 parts by weight of N,N-dimethyl-4-aminoazobenzene.

[0033] Furthermore, the gradient functional layer is prepared by the following method: KH560, TEOS, 4-cyano-4'-pentylbiphenyl and N,N-dimethyl-4-aminoazobenzene were mixed evenly and cured at 60°C for 15 minutes on the surface of the adhesive layer to obtain a first functional layer; KH560, TEOS, 4-cyano-4'-pentylbiphenyl and N,N-dimethyl-4-aminoazobenzene were mixed evenly and cured at 80°C for 15 minutes on the surface of the first functional layer to obtain a second functional layer; KH560, TEOS, 4-cyano-4'-pentylbiphenyl and N,N-dimethyl-4-aminoazobenzene were mixed evenly and cured at 100°C for 15 minutes on the surface of the second functional layer to obtain a third functional layer, thereby completing the preparation of the gradient functional layer.

[0034] Furthermore, the transparent layer is prepared by the following method: 15 to 25 parts by weight of cage-type octaphenylsilsesquioxane, 8 to 12 parts by weight of triazine-based epoxy resin, 8 parts by weight of PETA curing agent, 5 parts by weight of 4-cyano-4'-pentylbiphenyl and 3 parts by weight of N,N-dimethyl-4-aminoazobenzene are mixed evenly, and then cured at 130° C. for 8 minutes on the surface of the gradient functional layer to obtain a transparent layer.

[0035] Furthermore, a method for preparing the above-mentioned INS high-temperature-resistant and scratch-resistant automobile decorative film specifically includes the following steps: under nitrogen protection and electric field induction, preparing an adhesive layer on the surface of the substrate, preparing a gradient functional layer on the surface of the adhesive layer, and preparing a transparent layer on the surface of the gradient functional layer, thereby obtaining the INS high-temperature-resistant and scratch-resistant automobile decorative film.

[0036] Example 1 An INS high-temperature-resistant and scratch-resistant automotive decorative film is prepared by the above method and comprises a substrate, an adhesive layer, a gradient functional layer and a transparent layer in sequence; The adhesive layer comprises the following raw materials in parts by weight: 40 parts by weight of polydimethylsiloxane; 5 parts by weight of vinyltriethoxysilane; 0.1 parts by weight of DBTDL catalyst; 5 parts by weight of 4-cyano-4'-pentylbiphenyl; 3 parts by weight of N,N-dimethyl-4-aminoazobenzene.

[0037] The transparent layer is prepared by the following method: 20 parts by weight of cage-type octaphenylsilsesquioxane, 10 parts by weight of triazine-based epoxy resin, 8 parts by weight of PETA curing agent, 5 parts by weight of 4-cyano-4'-pentylbiphenyl and 3 parts by weight of N,N-dimethyl-4-aminoazobenzene are mixed evenly, and then cured on the surface of the gradient functional layer at 130° C. for 8 minutes to obtain a transparent layer.

[0038] Example 2 An INS high-temperature-resistant and scratch-resistant automotive decorative film is prepared by the above method and comprises a substrate, an adhesive layer, a gradient functional layer and a transparent layer in sequence; The adhesive layer comprises the following raw materials in parts by weight: 35 parts by weight of polydimethylsiloxane; 5 parts by weight of vinyltriethoxysilane; 0.1 parts by weight of DBTDL catalyst; 5 parts by weight of 4-cyano-4'-pentylbiphenyl; 3 parts by weight of N,N-dimethyl-4-aminoazobenzene.

[0039] The transparent layer is prepared by the following method: 15 parts by weight of cage-type octaphenylsilsesquioxane, 12 parts by weight of triazine-based epoxy resin, 8 parts by weight of PETA curing agent, 5 parts by weight of 4-cyano-4'-pentylbiphenyl and 3 parts by weight of N,N-dimethyl-4-aminoazobenzene are mixed evenly, and then cured on the surface of the gradient functional layer at 130° C. for 8 minutes to obtain a transparent layer.

[0040] Example 3 An INS high-temperature-resistant and scratch-resistant automotive decorative film is prepared by the above method and comprises a substrate, an adhesive layer, a gradient functional layer and a transparent layer in sequence; The adhesive layer comprises the following raw materials in parts by weight: 45 parts by weight of polydimethylsiloxane; 4 parts by weight of vinyltriethoxysilane; 0.1 parts by weight of DBTDL catalyst; 5 parts by weight of 4-cyano-4'-pentylbiphenyl; 3 parts by weight of N,N-dimethyl-4-aminoazobenzene.

[0041] The transparent layer is prepared by the following method: 25 parts by weight of cage-type octaphenylsilsesquioxane, 8 parts by weight of triazine-based epoxy resin, 8 parts by weight of PETA curing agent, 5 parts by weight of 4-cyano-4'-pentylbiphenyl and 3 parts by weight of N,N-dimethyl-4-aminoazobenzene are mixed evenly, and then cured at 130° C. for 8 minutes on the surface of the gradient functional layer to obtain a transparent layer.

[0042] Comparative Example 1 An INS high-temperature-resistant and scratch-resistant automobile decorative film differs from Example 1 in that it does not include an adhesive layer.

[0043] Comparative Example 2 An INS high-temperature-resistant and scratch-resistant automobile decorative film differs from Example 1 in that it does not include a gradient functional layer.

[0044] Comparative Example 3 An INS high-temperature-resistant and scratch-resistant automobile decorative film differs from Example 1 in that it does not include a transparent layer.

[0045] Comparative Example 4 An INS high-temperature-resistant and scratch-resistant automobile decorative film is different from Example 1 in that no electric field is applied during the preparation process of the automobile decorative film.

[0046] The performance of the INS high temperature resistant and scratch resistant automotive decorative films of Examples 1 to 3 and Comparative Examples 1 to 4 was tested, and the results are shown in the following table: Table 1

[0047] Table 2

[0048] Table 3

[0049] Table 4

[0050] Transmittance analysis As can be seen from Table 1, the light transmittance of Examples 1-3 exceeds 93%, with excellent light transmittance, haze less than 1.0%, color difference less than 0.5, and good optical performance. Comparative Example 1 lacks an adhesive layer, and the substrate is in direct contact with the gradient functional layer. The sudden change in refractive index leads to an increase in interface reflection loss. At the same time, there is no transition effect of the adhesive layer, which increases the roughness of the interface between the substrate and the gradient functional layer, causing scattering loss, thereby reducing optical uniformity, causing the light transmittance to drop to 88.3%, the haze to increase to 2.1%, and the color difference to reach 1.2; Comparative Example 2 lacks a gradient functional layer, resulting in a direct combination of the adhesive layer and the transparent layer, causing stress concentration, thereby affecting optical uniformity. There is no gradient transition effect of the gradient functional layer, and the refractive index difference between the adhesive layer and the transparent layer is large, resulting in enhanced Fresnel reflection, which leads to a decrease in light transmittance. To 89.7%, haze 1.8%, color difference 0.9; Comparative Example 3 lacks a transparent layer, resulting in the INS high-temperature resistant and scratch-resistant automotive decorative film losing the refractive index adjustment function of the outermost layer. At the same time, the high cross-linking density component of the outermost transparent layer is missing, resulting in a decrease in the flatness of the decorative film surface and increased surface scattering, thereby affecting the optical performance, with a transmittance of 91.2%, a haze of 1.4%, and a color difference of 0.7; Comparative Example 4 lacks electric field treatment, and the liquid crystal molecules 4-cyano-4'-pentylbiphenyl fail to achieve orderly arrangement. The chaotic molecular arrangement leads to increased light scattering, thereby affecting the light transmittance, resulting in a transmittance of 92.1%, a haze of 1.2%, and a color difference of 0.6. The technical solution of the present invention achieves a transparency of over 95% by providing a high cross-linking density transparent layer of cage-type octaphenylsilsesquioxane and triazine-based epoxy resin, significantly reducing surface scattering, while the transparent material plays a refractive index adjustment function; by controlling the components and providing a gradient functional layer, a continuous transition of the refractive index from the transparent layer to the adhesive layer is achieved, thereby increasing optical uniformity and reducing Fresnel reflection; and by inducing the orderly arrangement of 4-cyano-4'-pentylbiphenyl liquid crystal molecules through an electric field, scattering is reduced, intermolecular interactions and interface bonding are improved, thereby achieving excellent optical transparency with a transmittance exceeding 93%, a haze less than 1.0%, and a color difference less than 0.5.

[0051] Scratch resistance analysis As can be seen from Table 1, the pencil hardness of Examples 1-3 all reached 5H to 7H, the number of anti-scratch times exceeded 11,800 times, the adhesion was 4B, and the scratch resistance was excellent. Comparative Example 1 lacks an adhesive layer, resulting in direct contact between the substrate and the gradient functional layer, lacks flexibility buffering, and insufficient interface bonding strength. Under the action of external force, stress concentration and interface peeling are easily generated, thereby reducing the surface hardness and scratch resistance, resulting in a pencil hardness of only 3H, an anti-scratch number of only 4,200 times, and an adhesion of 1B; Comparative Example 2 lacks a gradient functional layer, the modulus difference between the adhesive layer and the transparent layer is too large, and there is a lack of gradient transition to relieve stress. During the scratching process, brittle fracture of the interface is easily generated, thereby affecting the overall anti-scratch performance, resulting in a pencil hardness of 4H, an anti-scratch number of 6,800 times, and an adhesion of 3. B; Comparative Example 3 lacks a transparent layer and loses the outermost layer of high-crosslink density cage-type octaphenylsilsesquioxane and triazine-based epoxy resin components, resulting in a significant decrease in surface hardness and a lack of effective anti-scratch protection, which leads to the most obvious decrease in scratch resistance, resulting in a minimum pencil hardness of only 2H and a scratch resistance of only 3500 times; Comparative Example 4 lacks electric field treatment, and the liquid crystal molecules 4-cyano-4'-pentylbiphenyl fail to achieve orderly arrangement, resulting in weak intermolecular forces and insufficient interfacial bonding, thereby affecting the overall mechanical strength and scratch resistance, resulting in a pencil hardness of 4H, a scratch resistance of 7200 times, and an adhesion of 3B. The technical solution of the present invention greatly improves the surface hardness and cross-linking density by adding the unique cage molecular structure of cage-type octaphenylsilsesquioxane and triazine-based epoxy resin to the transparent layer, thereby achieving excellent anti-scratch protection; the gradient distribution of KH560 and TEOS content in the gradient functional layer forms a continuous change in cross-linking density and inorganic network strength, effectively alleviating the modulus difference between different layers and avoiding interface brittle fracture; the polydimethylsiloxane system of the adhesive layer provides excellent flexibility and low surface energy properties, ensuring a firm bond between the film material and the substrate; the electric field induces the orderly arrangement of 4-cyano-4'-pentylbiphenyl liquid crystal molecules to improve molecular orientation and interface compatibility, thereby achieving excellent scratch resistance with a pencil hardness of 5H to 7H, a scratch resistance of more than 11,800 times, and an adhesion of 4B.

[0052] High temperature resistance analysis As can be seen from Table 1, the operating temperature range of Examples 1-3 all reaches -40°C to above 190°C, the glass transition temperature exceeds 175°C, the thermal expansion coefficient is lower than 50ppm / °C, and the high temperature resistance is excellent. Comparative Example 1 lacks an adhesive layer, resulting in direct contact between the substrate and the gradient functional layer. There is a lack of a flexible buffer layer to relieve thermal stress. Thermal cracking and delamination are prone to occur at high temperatures, thereby affecting the overall thermal stability, resulting in a glass transition temperature of only 145°C, an operating temperature range of -35°C to 165°C, and a thermal expansion coefficient of up to 78ppm / °C; Comparative Example 2 lacks a gradient functional layer, and the adhesive layer is directly combined with the transparent layer, resulting in poor thermal expansion matching. The thermal stress between the layers cannot be effectively released at high temperatures, resulting in interface stress concentration, thereby affecting thermal stability, resulting in a glass transition temperature of 158°C, an operating temperature range of -30°C to 172°C, and a thermal expansion coefficient of 68ppm / °C; Comparative Example 2 lacks a gradient functional layer, and the adhesive layer is directly combined with the transparent layer, resulting in poor thermal expansion matching. The thermal stress between the layers cannot be effectively released at high temperatures, resulting in interface stress concentration, thereby affecting thermal stability, resulting in a glass transition temperature of 158°C, an operating temperature range of -30°C to 172°C, and a thermal expansion coefficient of 68ppm / °C; 3 lacks a transparent layer, and the ultra-high thermal stability protection of the cage-type octaphenylsilsesquioxane is lost, resulting in a significant decrease in surface heat resistance. At the same time, the lack of the high cross-linking density triazine-based epoxy resin component leads to the most obvious decline in overall thermal performance, with the lowest glass transition temperature of only 135°C, an operating temperature range of -25°C to 155°C, and a thermal expansion coefficient of 85ppm / °C; Comparative Example 4 lacks electric field treatment, and the liquid crystal molecules 4-cyano-4'-pentylbiphenyl fail to achieve orderly arrangement, resulting in poor intermolecular force and thermal stability, thereby affecting the overall heat resistance, resulting in a glass transition temperature of 162°C, an operating temperature range of -35°C to 175°C, and a thermal expansion coefficient of 62ppm / °C. The technical solution of the present invention adds cage-type octaphenylsilsesquioxane with a thermal decomposition temperature of over 600°C to the transparent layer. Its unique cage-type molecular structure provides excellent high-temperature stability, and the triazine-based epoxy resin enhances the crosslinking density to further improve the heat resistance. The gradient distribution of KH560 and TEOS in the gradient functional layer forms a continuous change in crosslinking density and inorganic network strength, effectively alleviating thermal expansion differences and avoiding interfacial stress cracking at high temperatures. The polydimethylsiloxane system of the bonding layer provides excellent low-temperature flexibility and high-temperature stability. The electric field induces the orderly arrangement of 4-cyano-4'-pentylbiphenyl liquid crystal molecules to improve the intermolecular force and thermal stability, thereby achieving a wide temperature range of -40°C to 198°C and excellent thermal stability.

[0053] In summary, the present invention adopts a multi-layer gradient structure design and combines it with an electric field induced preparation process to prepare INS high-temperature resistant and scratch-resistant automobile decorative film, thereby achieving a comprehensive improvement in the high-temperature resistance, scratch resistance and light transmittance of the automobile decorative film.

[0054] Although the embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and variations may be made to these embodiments without departing from the principles and spirit of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. An INS high temperature resistant and scratch resistant automotive decorative film, characterized in that: The method comprises a substrate, an adhesive layer, a gradient functional layer and a transparent layer in sequence; The substrate is a polycarbonate substrate; The adhesive layer is a silicone polymer layer; The gradient functional layer adopts a silane coupling agent layer, including a first functional layer, a second functional layer and a third functional layer; The transparent layer adopts a high cross-linking density hardness layer; The INS high-temperature-resistant and scratch-resistant automobile decorative film is prepared under nitrogen protection and electric field induction.

2. The INS high temperature resistant and scratch resistant automobile decorative film according to claim 1, characterized in that: The specific parameters of the electric field induction are: the electric field strength is 2kV / cm when preparing the adhesive layer, the electric field strength is 3kV / cm when preparing the gradient functional layer, and the electric field strength is 5kV / cm when preparing the transparent layer. The electric field frequency is fixed at 5kHz, the waveform is a sine wave, indium tin oxide transparent electrodes are used, the electrode spacing is 500μm, and the electric field uniformity is ±2%.

3. The INS high temperature resistant and scratch resistant automobile decorative film according to claim 1, characterized in that: The thickness of the adhesive layer is 15-20 μm, the thickness of the transparent layer is 8-10 μm, the thickness of the gradient functional layer is 15 μm, and the thickness ratio of the first functional layer, the second functional layer and the third functional layer is 1:1:

1.

4. The INS high temperature resistant and scratch resistant automobile decorative film according to claim 1, characterized in that: The adhesive layer comprises the following raw materials in parts by weight: 35-45 parts by weight of polydimethylsiloxane; 4-5 parts by weight of vinyltriethoxysilane; 0.1 parts by weight of DBTDL catalyst; 5 parts by weight of 4-cyano-4'-pentylbiphenyl; 3 parts by weight of N,N-dimethyl-4-aminoazobenzene.

5. The INS high temperature resistant and scratch resistant automobile decorative film according to claim 1, characterized in that: The adhesive layer is prepared by the following method: polydimethylsiloxane, vinyltriethoxysilane, DBTDL catalyst, 4-cyano-4'-pentylbiphenyl and N,N-dimethyl-4-aminoazobenzene are mixed evenly, spin-coated on the substrate surface at 1500 rpm for 30 seconds, and cured at 50°C for 30 minutes to obtain an adhesive layer with a thickness of 15-20 μm.

6. The INS high temperature resistant and scratch resistant automobile decorative film according to claim 1, characterized in that: The substrate is prepared by the following method: a polycarbonate substrate is cleaned with anhydrous ethanol, treated at room temperature for 10 minutes, treated with ultraviolet ozone for 5 minutes, and treated with oxygen plasma at a power of 100 W for 30 seconds to obtain the substrate.

7. The INS high temperature resistant and scratch resistant automobile decorative film according to claim 1, characterized in that: The first functional layer comprises the following raw materials in parts by weight: 20 parts by weight of KH560, 5 parts by weight of TEOS, 5 parts by weight of 4-cyano-4'-pentylbiphenyl and 3 parts by weight of N,N-dimethyl-4-aminoazobenzene; The second functional layer comprises the following raw materials in parts by weight: 25 parts by weight of KH560, 10 parts by weight of TEOS, 5 parts by weight of 4-cyano-4'-pentylbiphenyl and 3 parts by weight of N,N-dimethyl-4-aminoazobenzene; The third functional layer includes the following raw materials in parts by weight: 30 parts by weight of KH560, 15 parts by weight of TEOS, 5 parts by weight of 4-cyano-4'-pentylbiphenyl and 3 parts by weight of N,N-dimethyl-4-aminoazobenzene.

8. The INS high temperature resistant and scratch resistant automobile decorative film according to claim 1, characterized in that: The gradient functional layer is prepared by the following method: KH560, TEOS, 4-cyano-4'-pentylbiphenyl and N,N-dimethyl-4-aminoazobenzene were mixed evenly and cured at 60°C for 15 minutes on the surface of the adhesive layer to obtain a first functional layer; KH560, TEOS, 4-cyano-4'-pentylbiphenyl and N,N-dimethyl-4-aminoazobenzene were mixed evenly and cured at 80°C for 15 minutes on the surface of the first functional layer to obtain a second functional layer; KH560, TEOS, 4-cyano-4'-pentylbiphenyl and N,N-dimethyl-4-aminoazobenzene were mixed evenly and cured at 100°C for 15 minutes on the surface of the second functional layer to obtain a third functional layer, thereby completing the preparation of the gradient functional layer.

9. The INS high temperature resistant and scratch resistant automobile decorative film according to claim 1, characterized in that: The transparent layer is prepared by the following method: 15 to 25 parts by weight of cage-type octaphenylsilsesquioxane, 8 to 12 parts by weight of triazine-based epoxy resin, 8 parts by weight of PETA curing agent, 5 parts by weight of 4-cyano-4'-pentylbiphenyl and 3 parts by weight of N,N-dimethyl-4-aminoazobenzene are mixed evenly, and the mixture is cured on the surface of the gradient functional layer at 130° C. for 8 minutes to obtain a transparent layer.

10. A method for preparing the INS high-temperature-resistant and scratch-resistant automobile decorative film according to any one of claims 1 to 9, characterized in that: The specific steps include: Under nitrogen protection and electric field induction, an adhesive layer is prepared on the surface of the substrate, a gradient functional layer is prepared on the surface of the adhesive layer, and a transparent layer is prepared on the surface of the gradient functional layer to obtain the INS high-temperature and scratch-resistant automobile decorative film.

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