High-temperature-resistant UV-cured viscosity-reducing film for vacuum coating and preparation method thereof

Abstract

The invention relates to the technical field of functional polymer films, in particular to a high-temperature-resistant UV-cured viscosity-reducing film for vacuum coating and a preparation method of the high-temperature-resistant UV-cured viscosity-reducing film. The base material adopts a modified film and is subjected to plasma pretreatment; the adhesive layer is composed of a high-temperature-resistant epoxy acrylate prepolymer, a polyfunctional group UV monomer, a photoinitiator and an interface regulator, and a cross-linking agent can be selectively added; the preparation method comprises the steps of base material pretreatment, adhesive layer composition preparation, gradient gluing, pre-curing and high-temperature post-treatment. The viscosity-reducing film is resistant to high temperature, controllable in bonding force, free of adhesive residues, stable in size, good in interface bonding performance and suitable for a high-temperature vacuum coating process. The product disclosed by the invention has the advantages of excellent high-temperature resistance, controllable bonding force, no adhesive residue in stripping, strong dimensional stability and firm interface bonding.

Description

Technical Field

[0001] This invention relates to the field of functional polymer thin film technology, specifically to a high-temperature UV-curable anti-sticking film for vacuum coating and its preparation method. Background Technology

[0002] UV-curable anti-adhesion film, as a core functional material in vacuum coating processes, directly determines the processing precision and finished product quality of coated products, playing an irreplaceable role in high-end manufacturing fields such as optical devices and precision hardware. Its core function is to temporarily fix the substrate during processes such as vacuum evaporation coating, magnetron sputtering coating, and ion plating, effectively preventing substrate displacement and vibration-induced scratches or uneven thickness of the coating layer. After coating is completed, UV irradiation triggers a chemical cross-linking reaction in the adhesive layer, rapidly reducing adhesion and achieving precise, damage-free peeling. It has become an indispensable key consumable in precision coating processes.

[0003] With the rapid development of emerging industries such as 5G communication, semiconductors, and optical displays, the market demands for the precision and environmental stability of coated products are continuously increasing. Coating processes are gradually upgrading towards higher temperatures and greater precision, with vacuum coating environments now generally reaching 150-180℃. However, current mainstream UV anti-adhesion films face significant technical bottlenecks, making them unsuitable for mid-to-high-end high-temperature coating scenarios. Existing products mostly use PET and PP as substrates, with adhesive layers employing common acrylate systems, which can only meet the low-temperature coating requirements of 80-100℃, severely limiting their application in high-temperature environments.

[0004] The core defects of the existing technology are mainly reflected in three aspects: First, insufficient temperature resistance. Low-temperature substrates have extremely poor thermal stability in high-temperature environments above 150℃, and are prone to significant shrinkage and warping deformation, which in turn leads to cracks and peeling of the surface coating layer, directly resulting in product scrap. Second, lack of high-temperature stability design of the adhesive layer. Ordinary acrylic adhesive layers are prone to molecular chain breakage, component migration and cross-linking failure at high temperatures, resulting in prominent residual adhesive problems after coating. The residual adhesive layer not only affects the cleanliness of the product appearance, but also seriously damages the optical performance, electrical performance and adhesion of the coating layer. Third, unbalanced design of interfacial bonding force. The interfacial force matching between the adhesive layer and special coating substrates such as metal targets, optical glass and ceramics is unreasonable. Either the peel force is too small before UV irradiation, and the substrate is not firmly fixed and cannot withstand the slight stress during the coating process, or the peel force is too large after UV irradiation, making the peeling process difficult and easily causing damage to the coating layer or the substrate, which seriously affects production efficiency and product yield.

[0005] Against this backdrop, the industry's demand for technological upgrades of UV anti-adhesion films is becoming increasingly urgent. As the requirements for precision, weather resistance, and reliability of coated products continue to increase in the high-end manufacturing sector, there is an urgent need to develop a UV anti-adhesion film with high-temperature resistance, strong high-temperature stability of the adhesive layer, excellent interface compatibility, and controllable peel force. This is to solve the core pain points in high-temperature coating processes, fill the gap in the mid-to-high-end market, and support the high-quality development of industries such as 5G, semiconductors, and optical displays. Summary of the Invention

[0006] (a) Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a high-temperature resistant UV-curable anti-sticking film for vacuum coating and its preparation method.

[0007] (II) Technical Solution A high-temperature resistant UV-curable anti-sticking film for vacuum coating includes a substrate and an adhesive layer. The substrate is a modified PI film or a modified PET film. The adhesive layer is a quaternary system consisting of a high-temperature resistant epoxy acrylate prepolymer, a multifunctional UV monomer, a composite photoinitiator, and an interface modifier. The epoxy value of the high-temperature resistant epoxy acrylate prepolymer is 0.4-0.6 eq / 100g. The weight parts of each component of the adhesive layer are: 32-38 parts of high-temperature resistant epoxy acrylate prepolymer, 48-52 parts of multifunctional UV monomer, 3-5 parts of composite photoinitiator, and 1-3 parts of interface modifier.

[0008] Preferably, the multifunctional UV monomer is a compound of ETMPTA and DPHA, wherein the functionality of ETMPTA is 6, the functionality of DPHA is 6-8, and the mass ratio of the two is 1:1-1:1.2.

[0009] Preferably, the substrate is pretreated with argon plasma, and the pretreatment parameters are 350-450W power and 25-35s treatment time.

[0010] Preferably, the interface modifier is a compound of silane coupling agent KH-550 and titanate coupling agent NDZ-311, with a mass ratio of 1:1; wherein the amino content of silane coupling agent KH-550 is 1.2-1.5 mmol / g, and the titanium content of titanate coupling agent NDZ-311 is 8-10%.

[0011] Preferably, the composite photoinitiator is a mixture of 907 and TPO, with a mass ratio of 1.5:1 to 2:1.

[0012] Preferably, the adhesive layer also contains 0.5-1.5 parts of isocyanate crosslinking agent, and the heat conduction rate is controlled at 5-10℃ / min.

[0013] Preferably, the method for preparing the high-temperature UV-curable anti-sticking film for vacuum coating includes the following steps: S1. Substrate pretreatment: The modified PI film or modified PET film is pretreated with argon plasma. The argon flow rate is controlled at 10-20 sccm, the pretreatment power is 350-450W, and the treatment time is 25-35s, until the substrate surface dyne value is 56mN / m and the roughness Ra is 0.05-0.1μm. S2. Preparation of adhesive layer composition: Weigh out the high-temperature resistant epoxy acrylate prepolymer, multifunctional UV monomer, composite photoinitiator, interface modifier and isocyanate crosslinking agent according to the mass ratio, mix at 25-30℃ and 500-800rpm for 20-30min, add 907 first and stir for 10min, then add TPO to obtain a uniform adhesive layer composition. S3. Gradient coating: The adhesive composition prepared in step S2 is coated onto the surface of the substrate after pretreatment in step S1 using a micro-gravure coating method. The coating rate decreases by 10-20% from the surface of the substrate outwards, and the wet film thickness is controlled to be 7~40μm. S4. Pre-curing: Place the coated substrate in an environment with a temperature of 85-95℃ and a humidity of 30-50%RH, and gradually increase the temperature to the set temperature at a heating rate of 2-3℃ / min, and pre-cur for 3.5-4.5min; S5. High-temperature post-treatment: Place the pre-cured substrate in an environment of 105-115℃ for constant temperature treatment for 2.5-3 minutes, control the ventilation rate to 0.5-1m / s, and conduct heat evenly to obtain a high-temperature resistant UV-cured anti-stick film for vacuum coating.

[0014] Preferably, in S1, the argon purity of the argon plasma is ≥99.99%, the pretreatment power is 400-450W, the treatment time is 30-35s, and the surface roughness Ra of the substrate after treatment is controlled at 0.07-0.09μm.

[0015] Preferably, in S4, the pre-curing temperature is 90-95℃, the pre-curing time is 4-4.5min, and the surface temperature of the substrate is monitored in real time by infrared thermometry during the curing process with an error ≤±1℃; in S5, the high-temperature post-treatment temperature is 110-115℃, the treatment time is 2.8-3min, and the substrate is naturally cooled to room temperature after treatment with a cooling rate ≤5℃ / min.

[0016] Preferably, in S2, the isocyanate crosslinking agent is hexamethylene diisocyanate trimer with a purity ≥99%; the mass ratio of ETMPTA to DPHA in the multifunctional UV monomer is 1:1.1; the mass ratio of 907 to TPO in the composite photoinitiator is 1.8:1; and the mass ratio of KH-550 to NDZ-311 in the interface modifier is 1:1.

[0017] (iii) Beneficial technical effects Compared with existing technologies, the beneficial effects of this invention are: 1. By optimizing the selection of substrate and the design of the adhesive layer molecular structure, the upper limit of the product's temperature resistance has been greatly improved, making it fully adaptable to the high-temperature working environment of 150-200℃ for vacuum coating. This effectively avoids the shrinkage and warping problems of traditional products at high temperatures. The substrate maintains good dimensional stability throughout the coating process, eliminating the cracking and peeling of the coating layer caused by substrate deformation from the root, and providing a reliable guarantee for the structural integrity of the coated product.

[0018] 2. By innovatively designing a quaternary system of "high-temperature resistant epoxy acrylate prepolymer + multifunctional UV monomer + composite photoinitiator + interface modifier" and introducing dynamic crosslinking control technology, the high-temperature stability of the adhesive layer is significantly enhanced. In high-temperature coating environments, the migration of adhesive layer components is effectively suppressed, the crosslinking structure is stable and not prone to failure, and no residue is left on the surface of the adhered object after peeling. This completely solves the problem of high residue rate in traditional products, ensures the cleanliness of the coated product surface, and avoids the adverse effects of residue on the product's appearance and core performance.

[0019] 3. By optimizing the surface properties of the substrate through argon plasma pretreatment and combining it with a special interface modifier, the interfacial adhesion between the adhesive layer and various coating substrates such as metal targets, optical glass, and ceramics is significantly improved. Before UV irradiation, the adhesive layer provides a stable fixation effect for the substrate, resisting various stresses during the coating process and preventing substrate displacement. After UV irradiation, the adhesion force decreases rapidly, enabling easy and damage-free peeling. This avoids the problems of weak fixation or difficult peeling in traditional products, and reduces the loss of the coating layer and substrate during peeling, significantly improving the convenience of production operations and product yield. Attached Figure Description

[0020] Figure 1 This is a flowchart of the method for preparing a high-temperature UV-curable anti-sticking film for vacuum coating disclosed in this invention; Figure 2 This is a comparison chart showing the peel strength after UV irradiation and the adhesive strength before UV irradiation for the examples and comparative examples; Figure 3 This is a bar chart comparing the longitudinal shrinkage rate and the transverse shrinkage rate of the substrate at 180°C in the examples and comparative examples; Figure 4 This is a radar comparison chart created by standardizing the dimensions of the performance comparison data between the examples and the comparative examples. Detailed Implementation

[0021] according to Figures 1 to 4 The specific embodiments of the present invention are as follows: The following detailed description, in conjunction with embodiments and comparative examples, illustrates the high-temperature UV-curable anti-sticking film for vacuum coating of the present invention and its preparation method. All raw materials are industrial-grade qualified products, meeting the corresponding technical parameter requirements; the equipment used is conventional supporting equipment for vacuum coating processing, with stable performance and conforming to process operation standards.

[0022] I. Raw Material Preparation (a) Substrate Modified PET film: 50 μm thickness, 130 MPa tensile strength, 150% elongation at break; Modified PI film: thickness 40μm, tensile strength 220MPa, elongation at break 60%; Ordinary PET film: 50μm thick, unmodified, tensile strength 150MPa, elongation at break 150%.

[0023] (ii) Tack coat components High-temperature resistant epoxy acrylate prepolymers: epoxy values ​​of 0.4 eq / 100g, 0.5 eq / 100g, and 0.6 eq / 100g, respectively; Multifunctional UV monomers: ETMPTA, functionality 6, purity 99%; DPHA, functionality 7, purity 99%; Composite photoinitiators: 907, 98% purity; TPO, 98% purity; Interface modifiers: silane coupling agent KH-550, amino content 1.3 mmol / g; titanate coupling agent NDZ-311, titanium content 9%; Isocyanate crosslinking agent: hexamethylene diisocyanate trimer, purity 99%; Ordinary acrylate prepolymer: epoxy value 0.3 eq / 100g; Single UV monomer: TPGDA, functionality 2, purity 98%; Single photoinitiator: 1173 (98% purity); Common silane coupling agent: KH-560, amino content 1.0 mmol / g.

[0024] (iii) Equipment Argon plasma treatment machine: power adjustment range 0-600W, argon flow control accuracy ±1sccm; High-speed disperser: speed adjustment range 0-1500rpm, temperature control accuracy ±1℃; Microgravure coating machine: coating rate adjustable range 1-10m / min, wet film thickness control accuracy ±0.5μm; Constant temperature and humidity curing chamber: temperature adjustment range 50-200℃, humidity adjustment range 20-80%RH, heating rate adjustment range 0.5-5℃ / min; High-temperature processing furnace: temperature control accuracy ±1℃, ventilation rate adjustment range 0-2m / s; Infrared thermometer: Measurement accuracy ±0.5℃; Dyne value tester: Measurement range 20-100mN / m; Roughness tester: Measurement accuracy ±0.01μm; Ordinary doctor blade coating machine: coating rate adjustment range 1-8m / min, wet film thickness control accuracy ±1μm; Standard drying oven: Temperature adjustment range 40-200℃, temperature control accuracy ±2℃.

[0025] II. Example 1 (a) Substrate pretreatment Modified PET film was selected as the substrate and flattened and fixed on the conveyor of an argon plasma treatment machine. The argon purity was set to 99.99%, the argon flow rate to 15 sccm, the pretreatment power to 400W, the treatment time to 30s, and the conveyor speed to 0.5m / min, ensuring the substrate surface was uniformly bombarded by plasma. Immediately after treatment, the dyne value of the substrate surface was measured using a dyne value tester, yielding a result of 56 mN / m; the surface roughness Ra was measured using a roughness meter, yielding a result of 0.07 μm.

[0026] (II) Preparation of adhesive layer composition Accurately weigh each component according to weight: 35 parts of high-temperature resistant epoxy acrylate prepolymer with an epoxy value of 0.4 eq / 100g, 50 parts of multifunctional UV monomers with a mass ratio of ETMPTA to DPHA of 1:1, 4 parts of composite photoinitiator with a mass ratio of 907 to TPO of 1.5:1, and 2 parts of interface modifier with a mass ratio of KH-550 to NDZ-311 of 1:1.

[0027] High-temperature resistant epoxy acrylate prepolymer, multifunctional UV monomer, and interface modifier were added to the dispersion vessel of a high-speed disperser. The temperature inside the dispersion vessel was set to 28°C and the rotation speed to 300 rpm. The equipment was started for stirring and mixing. After stirring for 10 minutes, the weighed 907 photoinitiator was added, and stirring was continued at the same speed for another 10 minutes until the 907 was completely and uniformly dispersed. Subsequently, TPO photoinitiator was added, and stirring was continued at the same speed for another 10 minutes, finally obtaining a uniform, transparent, and particulate-free tack coat composition. Throughout the mixing process, the heat transfer rate was strictly controlled at 8°C / min to avoid excessively high local temperatures that could cause premature reactions of the components.

[0028] (iii) Gradient coating The pretreated modified PET substrate was mounted on the unwinding device of a gravure coating machine. The coating machine parameters were adjusted: the initial coating rate was set to 5 m / min, and the substrate surface was divided into three coating zones outwards. The coating rate of each zone decreased by 15% compared to the previous zone, i.e., the coating rate of the second zone was 4.25 m / min, and the coating rate of the third zone was 3.61 m / min, achieving gradient coating. By adjusting the doctor blade gap of the coating machine, the wet film thickness of the adhesive composition was controlled to 10 μm. The coating status of the substrate surface was observed in real time during the coating process, and no defects such as missed coating, bubbles, or sagging were found.

[0029] (iv) Pre-curing The coated substrate was smoothly placed into a constant temperature and humidity curing chamber. The initial temperature of the curing chamber was set to 28℃ and the humidity to 40%RH. The temperature was gradually increased to 90℃ at a rate of 2.5℃ / min. During the heating process, the surface temperature of the substrate was monitored in real time using an infrared thermometer, and the temperature data was recorded every 30 seconds, with the temperature error controlled within ±1℃. After reaching the set temperature of 90℃, the substrate was pre-cured for 4 minutes under these temperature and humidity conditions.

[0030] (v) High-temperature post-treatment After pre-curing, the substrate is immediately placed in a high-temperature treatment oven. The oven temperature is set to 110℃, and the ventilation rate is 0.8m / s to ensure uniform heat distribution. This temperature and ventilation condition are maintained for 2.8 minutes of constant-temperature treatment. After treatment, the heating device is turned off, and the substrate is allowed to cool naturally to room temperature inside the oven. During cooling, the cooling rate is controlled at 3℃ / min to avoid rapid cooling that could cause internal stress between the substrate and the adhesive layer. After cooling to room temperature, a high-temperature UV-curable anti-adhesive film for vacuum coating is obtained.

[0031] III. Example 2 (a) Substrate pretreatment Modified PI film was selected as the substrate and fixed on the conveyor of an argon plasma treatment machine. The argon purity was set to 99.99%, the argon flow rate to 18 sccm, the pretreatment power to 430 W, the treatment time to 33 s, and the conveyor speed to 0.4 m / min. After treatment, the dyne value of the substrate surface was measured to be 56 mN / m, and the surface roughness Ra was 0.08 μm.

[0032] (II) Preparation of adhesive layer composition Weigh the following components by weight: 36 parts of high-temperature resistant epoxy acrylate prepolymer with an epoxy value of 0.5 eq / 100g; 51 parts of multifunctional UV monomer with a mass ratio of ETMPTA to DPHA of 1:1.1; 4.5 parts of composite photoinitiator with a mass ratio of 907 to TPO of 1.8:1; 2.5 parts of interface modifier with a mass ratio of KH-550 to NDZ-311 of 1:1; and 1.2 parts of hexamethylene diisocyanate trimer.

[0033] All components except the photoinitiator were added to the dispersion vessel of a high-speed disperser. The dispersion vessel temperature was set to 29°C and the rotation speed to 350 rpm. The equipment was started and stirred for 15 minutes. Then, 907 photoinitiator was added, and stirring was maintained at the same speed for 10 minutes. Then, TPO photoinitiator was added and stirring was continued for another 10 minutes, for a total mixing time of 35 minutes. During the mixing process, the heat transfer rate was controlled at 9°C / min, resulting in a uniform, fine, and impurity-free tack coat composition.

[0034] (iii) Gradient coating The adhesive coating operation was carried out using a microgravure coating machine. The initial coating rate was set to 4.5 m / min, and the coating rate decreased by 18% from the surface of the substrate outwards. That is, the coating rate of the second region was 3.69 m / min and the coating rate of the third region was 3.03 m / min. The wet film thickness was controlled to 15 μm by adjusting the doctor blade gap. After coating, the surface of the substrate was smooth and free of any defects.

[0035] (iv) Pre-curing The coated substrate was placed in a constant temperature and humidity curing chamber, with an initial temperature of 29℃ and humidity of 45%RH. The temperature was gradually increased to 93℃ at a rate of 2.8℃ / min. During the heating and curing process, the surface temperature of the substrate was monitored in real time using an infrared thermometer, with the temperature error controlled within ±0.8℃. After reaching 93℃, the substrate was held at this temperature for pre-curing for 4.2 minutes.

[0036] (v) High-temperature post-treatment After pre-curing, the substrate was placed in a high-temperature treatment furnace, with the furnace temperature set at 113°C, the ventilation rate at 0.9 m / s, and the temperature maintained for 2.9 min. After treatment, the substrate was allowed to cool naturally in the furnace at a controlled cooling rate of 4°C / min until it reached room temperature, at which point the product of Example 2 was obtained.

[0037] IV. Example 3 (a) Substrate pretreatment Modified PI film was selected as the substrate and fixed on the conveyor of an argon plasma treatment machine. The argon purity was set to 99.99%, the argon flow rate to 20 sccm, the pretreatment power to 450 W, the treatment time to 35 s, and the conveyor speed to 0.3 m / min. After treatment, the dyne value of the substrate surface was measured to be 56 mN / m, and the surface roughness Ra was 0.09 μm.

[0038] (II) Preparation of adhesive layer composition Weigh the following components by weight: 38 parts of high-temperature resistant epoxy acrylate prepolymer with an epoxy value of 0.6 eq / 100g; 52 parts of multifunctional UV monomer with a mass ratio of ETMPTA to DPHA of 1:1.2; 5 parts of composite photoinitiator with a mass ratio of 907 to TPO of 2:1; 3 parts of interface modifier with a mass ratio of KH-550 to NDZ-311 of 1:1; and 1.5 parts of hexamethylene diisocyanate trimer.

[0039] All components except the photoinitiator were added to the dispersion vessel of a high-speed disperser. The dispersion vessel temperature was set to 30°C and the stirring speed to 300 rpm, and the mixture was stirred for 18 minutes. Then, 907 photoinitiator was added, and stirring was maintained for 10 minutes. Finally, TPO photoinitiator was added, and stirring was continued for 12 minutes, for a total mixing time of 40 minutes. During the mixing process, the heat transfer rate was strictly controlled at 10°C / min. All components were thoroughly mixed without premature cross-linking. The final adhesive layer composition exhibited good uniformity, with no particles or stratification.

[0040] (iii) Gradient coating The microgravure coating machine is set with an initial coating rate of 5.5 m / min. The coating rate decreases by 20% from the substrate surface outwards, with the coating rate in the second region being 4.4 m / min and the coating rate in the third region being 3.52 m / min. The wet film thickness is controlled to 23 μm by precisely adjusting the doctor blade gap. After coating, the substrate surface is confirmed to be free of any defects such as missed coating, bubbles, or sagging by an online detection device.

[0041] (iv) Pre-curing The substrate to be coated is placed in a constant temperature and humidity curing chamber. The initial temperature is set to 30℃ and the humidity to 50%RH. The temperature is gradually increased to 95℃ at a rate of 3℃ / min. Throughout the curing process, the surface temperature of the substrate is monitored in real time using an infrared thermometer. The temperature error is ≤±0.5℃. After reaching 95℃, the substrate is pre-cured at this temperature for 4.5 minutes.

[0042] (v) High-temperature post-treatment The high-temperature treatment furnace was set to 115℃ with a ventilation rate of 1m / s, and the pre-cured substrate was subjected to a constant temperature treatment for 3 minutes. After the treatment was completed, the heating device was turned off, and the substrate was allowed to cool naturally to room temperature in the furnace at a controlled cooling rate of 5℃ / min. After cooling to room temperature, the product of Example 3 was obtained.

[0043] V. Comparative Example 1 (a) Substrate treatment Ordinary PET film was selected as the substrate and used directly for subsequent processing without argon plasma pretreatment. Its surface dyne value was measured to be 48 mN / m, and its roughness Ra was 0.03 μm.

[0044] (II) Preparation of adhesive layer composition Weigh the components by weight as follows: 40 parts of ordinary acrylate prepolymer, 50 parts of single UV monomer TPGDA, 5 parts of single photoinitiator 1173, and 2 parts of ordinary silane coupling agent KH-560. No isocyanate crosslinking agents were added.

[0045] All components were added to a high-speed disperser at once. The temperature inside the dispersion vessel was set to 35°C and the speed to 350 rpm. The mixture was stirred for 20 minutes. The heat transfer rate was not controlled. As a result, the final adhesive layer composition contained a small number of fine particles and had only moderate uniformity.

[0046] (iii) Applying adhesive The adhesive was applied using a standard doctor blade coater with a uniform coating rate of 3 m / min and no gradient reduction design. The wet film thickness was controlled to be 20 μm by adjusting the doctor blade gap. Slight sagging was observed on the substrate surface after coating.

[0047] (iv) Pre-curing The coated substrate was placed in a regular oven with the temperature set directly to 85°C. There was no gradual heating process, the humidity was not controlled, the curing time was 4 minutes, and the temperature was not monitored in real time. The temperature error was approximately ±2°C.

[0048] (v) Post-processing After pre-curing, the substrate was directly placed in a natural environment to cool to room temperature without any high-temperature post-treatment steps. The cooling rate was approximately 8°C / min, which is in line with conventional post-treatment methods in the prior art. After cooling to room temperature, the product of Comparative Example 1 was obtained.

[0049] VI. Performance Testing and Results Targeted performance tests were conducted on the products of Examples 1-3 and Comparative Example 1. The test items and standards are as follows: Temperature resistance: Place the product in a 180℃ vacuum oven for 2 hours and observe the changes in substrate size and adhesion. Adhesion test: A 180° peel test was used to test the values ​​before and after UV irradiation. The test substrate was optical glass. Residual adhesive: After UV irradiation, a peeling operation is performed. The presence of residual adhesive on the surface of the adhered object is determined by visual inspection combined with infrared spectroscopy. Dimensional stability: After being placed at 180℃ for 2 hours, the longitudinal and transverse shrinkage rates of the substrate were measured; Interface bonding stability: After the product is combined with the metal target, it is placed in a vacuum environment at 180℃ for 1 hour, and the change rate of peel force is tested after cooling.

[0050] The basic performance comparison between the examples and the comparative examples is shown in the table below: Table 1 The specific performance comparisons between the examples and comparative examples are shown in the table below: Table 2 The performance test data from both tables show that the high-temperature UV-curable anti-stick films for vacuum coating prepared in Examples 1-3 of this invention are significantly superior to the comparative products in both basic and specific performance. Regarding basic performance, the products in these examples demonstrate outstanding performance in high-temperature resistance to yellowing and cracking, controllable adhesion, residue-free characteristics, dimensional stability, UV curing efficiency, and uniformity of the adhesive layer appearance. Even though Example 1 did not contain an isocyanate crosslinking agent, its core performance still far surpasses existing technologies. In terms of specific performance, the products in the examples show significant advantages in extreme high-temperature aging, interfacial bonding stability, component migration inhibition, consistency in repeated use, high and low temperature adaptability, and resistance to damp heat aging, without adversely affecting the adhesion of the coating layer. Among them, Examples 2 and 3, due to the addition of isocyanate crosslinking agents, further optimize key performance aspects such as bonding strength and interfacial stability compared to Example 1, resulting in superior overall performance.

[0051] In contrast, the comparative products are prone to yellowing and cracking, large substrate shrinkage, and serious adhesive residue under high temperature environments. They also exhibit poor interfacial bonding stability and insufficient weather resistance, failing to meet the requirements of mid-to-high-end high-temperature vacuum coating processes. This fully demonstrates the advanced nature and practicality of the technical solution of this invention.

[0052] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high-temperature UV-curable anti-sticking film for vacuum coating, characterized in that, The product includes a substrate and an adhesive layer. The substrate is a modified PI film or a modified PET film. The adhesive layer is a quaternary system consisting of a high-temperature resistant epoxy acrylate prepolymer, a multifunctional UV monomer, a composite photoinitiator, and an interface modifier. The epoxy value of the high-temperature resistant epoxy acrylate prepolymer is 0.4-0.6 eq / 100g. The weight parts of each component of the adhesive layer are: 32-38 parts of the high-temperature resistant epoxy acrylate prepolymer, 48-52 parts of the multifunctional UV monomer, 3-5 parts of the composite photoinitiator, and 1-3 parts of the interface modifier.

2. The high-temperature UV-curable anti-sticking film for vacuum coating according to claim 1, characterized in that, The multifunctional UV monomer is a complex of ETMPTA and DPHA, with ETMPTA having a functionality of 6 and DPHA having a functionality of 6-8, and the mass ratio of the two being 1:1-1:1.

2.

3. The high-temperature UV-curable anti-sticking film for vacuum coating according to claim 1, characterized in that, The substrate is pretreated with argon plasma, and the pretreatment parameters are power 350-450W and treatment time 25-35s.

4. The high-temperature UV-curable anti-sticking film for vacuum coating according to claim 1, characterized in that, The interface modifier is a compound of silane coupling agent KH-550 and titanate coupling agent NDZ-311, with a mass ratio of 1:1; wherein the amino content of silane coupling agent KH-550 is 1.2-1.5 mmol / g, and the titanium content of titanate coupling agent NDZ-311 is 8-10%.

5. The high-temperature UV-curable anti-sticking film for vacuum coating according to claim 1, characterized in that, The composite photoinitiator is a mixture of 907 and TPO, with a mass ratio of 1.5:1 to 2:

1.

6. The high-temperature UV-curable anti-sticking film for vacuum coating according to claim 1, characterized in that, The adhesive layer also contains 0.5-1.5 parts of isocyanate crosslinking agent, and the heat conduction rate is controlled at 5-10℃ / min.

7. A method for preparing a high-temperature UV-curable anti-sticking film for vacuum coating as described in any one of claims 1-6, characterized in that, Includes the following steps: S1. Substrate pretreatment: The modified PI film or modified PET film is pretreated with argon plasma. The argon flow rate is controlled at 10-20 sccm, the pretreatment power is 350-450W, and the treatment time is 25-35s, until the substrate surface dyne value is 56mN / m and the roughness Ra is 0.05-0.1μm. S2. Preparation of adhesive layer composition: Weigh out high-temperature resistant epoxy acrylate prepolymer, multifunctional UV monomer, composite photoinitiator, interface modifier and isocyanate crosslinking agent, mix at 25-30℃ and 500-800rpm for 20-30min, add 907 first and stir for 10min, then add TPO to obtain a uniform adhesive layer composition. S3. Gradient coating: The adhesive composition prepared in S2 is coated onto the substrate surface after S1 pretreatment using a micro-gravure coating method. The coating rate decreases by 10-20% from the substrate surface outwards, and the wet film thickness is controlled to be 7~40μm. S4. Pre-curing: Place the coated substrate in an environment with a temperature of 85-95℃ and a humidity of 30-50%RH, and gradually increase the temperature to the set temperature at a heating rate of 2-3℃ / min, and pre-cur for 3.5-4.5min; S5. High-temperature post-treatment: Place the pre-cured substrate in an environment of 105-115℃ for constant temperature treatment for 2.5-3 minutes, control the ventilation rate to 0.5-1m / s, and conduct heat evenly to obtain a high-temperature resistant UV-cured anti-stick film for vacuum coating.

8. The method for preparing a high-temperature UV-curable anti-sticking film for vacuum coating according to claim 7, characterized in that, The argon purity of the argon plasma in S1 is ≥99.99%, the pretreatment power is 400-450W, the treatment time is 30-35s, and the surface roughness Ra of the substrate after treatment is controlled at 0.07-0.09μm.

9. The method for preparing a high-temperature UV-curable anti-sticking film for vacuum coating according to claim 7, characterized in that, In S4, the pre-curing temperature is 90-95℃ and the pre-curing time is 4-4.5min. During the curing process, the surface temperature of the substrate is monitored in real time using infrared thermometry with an error of ≤±1℃. In S5, the high-temperature post-treatment temperature is 110-115℃ and the treatment time is 2.8-3min. After treatment, the substrate is allowed to cool naturally to room temperature with a cooling rate of ≤5℃ / min.

10. The method for preparing a high-temperature UV-curable anti-sticking film for vacuum coating according to claim 7, characterized in that, The isocyanate crosslinking agent mentioned in S2 is hexamethylene diisocyanate trimer with a purity ≥99%; The mass ratio of ETMPTA to DPHA in the multifunctional UV monomer is 1:1.1, the mass ratio of 907 to TPO in the composite photoinitiator is 1.8:1, and the mass ratio of KH-550 to NDZ-311 in the interface modifier is 1:1.

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