An eb-cured stain-resistant resist decorative film coating and a method for preparing the same

Abstract

The present application relates to the technical field of functional decorative film coating materials, and particularly relates to an EB-cured stain-resistant and corrosion-resistant decorative film coating and a preparation method thereof, which comprises, by weight parts, JF806 perfluorinated modified acrylic resin 49.28-71.22, CY328 epoxy-modified saturated polyester resin 15.83-29.62, cross-linking promotion auxiliary compound system 1.18-1.97, active diluent compound system 9.87-15.74, nano-composite filler compound system 6.91-10.53, BYK333 polyether-modified organic silicon leveling agent 0.79-1.18. The present application adopts a solvent-free pure electron beam curing system, does not add a photo initiator and a thermal initiator in the whole process, cooperates with a low-oxygen inert atmosphere curing, eliminates oxygen inhibition defects and small molecule residue problems, and greatly improves coating cross-linking, surface uniformity and long-term stability.

Description

Technical Field

[0001] This invention relates to the field of functional decorative film coating materials technology, specifically to an EB-cured stain-resistant and corrosion-resistant decorative film coating and its preparation method. Background Technology

[0002] Decorative film coatings are core surface protection and decorative materials in the home furnishing, home appliance, and decorative building materials industries. The market demands for their stain resistance, corrosion resistance, adhesion stability, and long-term service performance are constantly increasing. Currently, most mainstream decorative film coatings in the industry rely on ultraviolet light curing systems. These systems require the addition of photoinitiators, and small molecule substances are easily left behind after curing. Long-term use can easily cause yellowing and performance degradation of the coating. Moreover, curing under normal air atmosphere makes it difficult to avoid oxygen inhibition problems, resulting in insufficient cross-linking of the coating and an increase in surface defects. Most existing coatings use single resin film formation, which cannot simultaneously achieve low surface energy stain resistance and high interfacial adhesion. There has long been a technical problem that stain resistance and adhesion are difficult to optimize in a coordinated manner.

[0003] Meanwhile, conventional technologies often use a single nanofiller for reinforcement, which cannot form a dense, multi-layered protective structure. The coating has many micropores, making it easy for acid and alkali media to penetrate and corrode it. Its corrosion resistance and wear resistance are difficult to meet the requirements of harsh application scenarios. Existing curing processes are mostly single-stage curing, which easily leads to the accumulation of residual stress inside the coating. Long-term use can easily result in failure phenomena such as cracking, powdering, and peeling.

[0004] Some solvent-free coating systems suffer from difficulties in viscosity control, poor leveling properties, and poor adaptability to high-speed coating, making it difficult to meet the efficiency and quality requirements of continuous industrial production. Overall, existing technologies cannot simultaneously meet the multiple requirements of being environmentally friendly and residue-free, stain-resistant and corrosion-resistant, having high adhesion, being process-compatible, and having long-term stability, which restricts the development and application of high-end decorative film coatings. There is an urgent need to develop new curing systems and composite formulation coating technologies to solve the above-mentioned technical problems. Summary of the Invention

[0005] The primary objective of this invention is to provide an EB-cured stain-resistant and corrosion-resistant decorative film coating and its preparation method.

[0006] A further objective of this invention is to provide an EB-cured stain-resistant and corrosion-resistant decorative film coating, comprising, by weight, 49.28-71.22 parts of JF806 perfluorinated modified acrylic resin, 15.83-29.62 parts of CY328 epoxy-modified saturated polyester resin, 1.18-1.97 parts of a crosslinking accelerator compound system, 9.87-15.74 parts of an reactive diluent compound system, 6.91-10.53 parts of a nanocomposite filler compound system, and BYK... 0.79-1.18 parts of 333 polyether modified silicone leveling agent; the coating is a solvent-free pure electron beam curing system, and no photoinitiator or thermal initiator is added during the curing process. The curing atmosphere is a nitrogen inert atmosphere with an oxygen content ≤100ppm, the electron beam acceleration voltage is 180keV, and the dry film thickness of the coating is 25μm±1μm; the coating adopts segmented gradient electron beam curing, with a surface pre-curing dose of 18kGy-20kGy and a deep curing dose of 25kGy-30kGy.

[0007] Preferably, the crosslinking accelerator compound system is composed of KH570 silane coupling agent and TMPDA aliphatic diacrylate in a weight ratio of 1:1.

[0008] Preferably, the reactive diluent compound system is composed of PEA200 bifunctional polyether diacrylate and TMPTA trifunctional trimethylolpropane triacrylate in a weight ratio of 2:1.

[0009] Preferably, the nanocomposite filler compounding system is composed of 30nm fumed silica nanoparticles and 50nm zirconium oxide nanoparticles in a layered compounding manner.

[0010] Preferably, the surface pre-curing rate is 8 m / min and the deep curing rate is 6.5 m / min.

[0011] A method for preparing an EB-cured stain-resistant and corrosion-resistant decorative film coating includes the following steps: (1) JF806 perfluorinated modified acrylic resin and CY328 epoxy modified saturated polyester resin were put into a closed stirred tank and premixed at room temperature at 1200 r / min for 15 min-20 min. The active diluent was added to the compound system and stirring was continued to obtain the composite resin matrix. (2) The nanocomposite filler compound system pretreated with KH570 was added to the composite resin matrix in batches and dispersed by high-speed stirring at 1800r / min for 25min-35min. The compound system of BYK333 polyether modified organosilicon leveling agent and crosslinking accelerator was added in sequence and stirred to obtain the coating liquid. (3) The coating liquid is applied to the PET decorative film substrate by roller coating process, and the dry film thickness is controlled to be 25μm±1μm; (4) Segmented gradient electron beam curing was carried out in a nitrogen inert atmosphere with oxygen content ≤100ppm. The electron beam acceleration voltage was 180keV. The surface pre-curing dose was 18kGy-20kGy and the curing rate was 8m / min. The deep curing dose was 25kGy-30kGy and the curing rate was 6.5m / min. The finished coating was obtained by cooling at room temperature. The KH570 pretreatment is as follows: using ethanol as solvent, the amount of KH570 silane coupling agent is 1%-3% of the total mass of the nanocomposite filler, stirring at 300r / min-500r / min at room temperature for 10min-15min, and then filtering and drying before use; The nitrogen inert atmosphere is produced by a three-stage replacement process, with a replacement pressure of 0.2MPa-0.4MPa, a nitrogen purity of ≥99.99%, and a pressure holding time of 3-5 minutes for each replacement. After replacement, the oxygen content is measured online to be ≤100ppm.

[0012] Preferably, in step (1), when the amount of JF806 perfluorinated modified acrylic resin is 71.22 parts, the premixing time is 20 min.

[0013] Preferably, in step (2), when the amount of nanocomposite filler compound system is 10.53 parts, the high-speed stirring time is 35 min.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention adopts a solvent-free pure electron beam curing system, without adding photoinitiators or thermal initiators throughout the process. Combined with curing in a low-oxygen inert atmosphere, it eliminates oxygen inhibition defects and small molecule residues, resulting in more complete cross-linking of the coating and significantly improved surface uniformity and long-term stability. Through the compounding of two resins, functional synergy is formed, balancing the coating's stain resistance and interfacial adhesion, solving the technical problem of performance imbalance in single resin systems. The coating has both excellent stain resistance and a strong bond with the substrate, eliminating the risk of peeling or flaking.

[0015] 2. This invention employs a layered compounding of dual-particle-size nanofillers to construct a three-dimensional protective structure with microscopic pore filling and macroscopic reinforcement, significantly improving coating density, effectively blocking the penetration of acid and alkali media, and enhancing the coating's corrosion resistance, wear resistance, and impact resistance. The synergistic effect of the compounded crosslinking aid and reactive diluent optimizes the system's interfacial wettability and leveling properties, precisely controls the viscosity of the liquid, adapts to high-speed coating processes, and solves problems such as uneven coating, agglomeration, and sagging in industrial production, thereby improving mass production stability.

[0016] 3. The segmented gradient curing process of this invention releases residual stress inside the coating step by step, avoiding uneven cross-linking and stress concentration cracking caused by single curing. The coating structure is more stable, and the mechanical properties and weather resistance are optimized simultaneously. The raw materials used in this invention are all commercially available general industrial raw materials. The preparation process parameters can be quantified and replicated, and it has both environmental protection and industrial production feasibility.

[0017] 4. The overall coating of this invention achieves comprehensive performance improvement in terms of stain resistance, corrosion resistance, adhesion, and weather resistance, which can meet the long-term use requirements of high-end decorative films in multiple scenarios and has obvious performance advantages and application value compared with existing technologies. Detailed Implementation

[0018] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] It should be noted that this invention is a 100% solvent-free pure electron beam curing coating system. No photoinitiator or thermal initiator needs to be added throughout the process. It relies on a closed nitrogen inert low-oxygen atmosphere (oxygen content ≤100ppm) to eliminate trace oxygen inhibition defects in the electron beam curing process, ensuring that the coating is uniform and completely cross-linked and cured.

[0020] The nitrogen atmosphere is produced using a three-stage replacement process. After replacement, the oxygen content is monitored online and meets the standards before solidification can proceed. The parameters are quantifiable and replicable.

[0021] All raw materials used in this invention are industrial-grade general-purpose chemical raw materials that can be stably purchased in bulk in the domestic market. There are no customized components, no confidential components, and no special or scarce raw materials.

[0022] Raw material parameters: JF806 perfluorinated modified acrylic resin (hexafunctional, low viscosity), CY328 epoxy modified saturated polyester resin (difunctional, high polarity), KH570 silane coupling agent, TMPDA difunctional monomer, PEA200 bifunctional diluent, TMPTA trifunctional diluent, 30nm / 50nm gas phase nanoparticles. All raw material models, technical parameters, commercial procurement channels, precise weight ratios, compounding relationships, and process parameters are fully disclosed. Those skilled in the art can accurately replicate and achieve the corresponding technical effects based on this solution, meeting the needs of industrial mass production.

[0023] The nanofillers are lightly pretreated with KH570 before use to avoid the problem of high filler agglomeration. The pretreatment process is publicly available and can be replicated.

[0024] To ensure consistent testing standards, this invention uses a fixed set of three compound systems, and all examples and comparative examples strictly adhere to the fixed compound ratios and mixing rules: (1) The crosslinking accelerator compound system is composed of KH570 silane coupling agent and TMPDA aliphatic diacrylate mixed in a weight ratio of 1:1, which is used to improve the interfacial bonding force and crosslinking reaction activity of the system. (2) The reactive diluent compound system is a mixture of PEA200 bifunctional polyether diacrylate and TMPTA trifunctional trimethylolpropane triacrylate in a weight ratio of 2:1, which is used to control the viscosity of the liquid and adapt to the high-speed coating process. (3) The nanocomposite filler compounding system is composed of 30nm fumed nano silica and 50nm nano zirconium oxide layered compounding, which is used to construct a three-dimensional protective structure with micro-filling and macro-reinforcement.

[0025] The electron beam curing method of this invention adopts industry-standard adaptive parameters, with the electron beam acceleration voltage fixed at 180keV, which is suitable for the low-temperature high-energy curing requirements of 20-30μm thin-layer coatings.

[0026] The dry film thickness of the coating is uniformly controlled at 25μm±1μm to ensure the consistency of the test.

[0027] Example 1: The coating materials in this embodiment are as follows, by weight: The compound components include a crosslinking accelerator compound system of 0.59 parts KH570 and 0.59 parts TMPDA, strictly compounded in a 1:1 ratio, with a total usage of 1.18 parts; an active diluent compound system of 6.58 parts PEA200 and 3.29 parts TMPTA, strictly compounded in a 2:1 ratio, with a total usage of 9.87 parts; and a nanocomposite filler compound system of 5.18 parts 30nm fumed silica and 1.73 parts 50nm zirconium oxide, with a layered compounding and a total usage of 6.91 parts.

[0028] The remaining basic components are 57.13 parts of JF806 perfluorinated modified acrylic resin, 23.63 parts of CY328 epoxy modified saturated polyester resin, and 0.79 parts of BYK333 polyether modified silicone leveling agent.

[0029] The standardized preparation steps in this embodiment are as follows: (1) Resin premixing and blending: The metered fluorinated modified acrylic resin and epoxy modified polyester resin were added to a sealed constant temperature stirring vessel and stirred for 15 minutes at room temperature and 1200 r / min to achieve initial compatibility of the high and low polarity dual resins. Then, a compounded reactive diluent was added and stirred for 10 minutes to obtain a uniform, transparent, non-layered, and flocculent composite resin matrix. The dual resin compounding can take into account the advantages of ultra-low surface energy, stain resistance and weather resistance of fluorinated resin and the characteristics of high interfacial polarity, high adhesion and high toughness of epoxy polyester resin, and improve the performance imbalance problem of single resin system.

[0030] (2) Functional system dispersion modification: The compounded nanocomposite filler was slowly added to the resin matrix in three batches. The stirring speed was adjusted to 1800 r / min and stirred at high speed for 25 min to completely eliminate the agglomeration of nanoparticles and ensure that the hierarchical filler was uniformly nested and dispersed. Small-particle filler was used to fill the micropores of the resin, and large-particle filler was used to build a protective skeleton to form a dense protective basic structure. Then, organosilicon leveling agent and compounded crosslinking promoter were added in sequence. The mixture was stirred at a constant temperature and speed for 10 min to obtain a homogeneous, particle-free coating liquid with excellent stability.

[0031] (3) Substrate coating and molding: conventional PET decorative film is selected as the substrate, and the liquid is uniformly coated by roller coating process, and the dry film thickness is precisely controlled to be 25μm±1μm. Fourth, segmented gradient electron beam curing: the whole process maintains a closed nitrogen inert low oxygen atmosphere with an oxygen content ≤100ppm. The precise gradient segmented curing mode is adopted. Unlike the defects of disordered variable speed curing in the existing technology, this scheme achieves performance optimization through segmented control of fixed dosage and fixed rate. The surface pre-curing dosage is 18kGy and the curing rate is 8m / min to achieve the initial cross-linking and shaping of the coating surface and prevent sagging and deformation after coating. The deep curing dosage is 25kGy to achieve the complete cross-linking reaction between the resin and active monomer inside the coating. After curing, the coating is naturally cooled to room temperature to release the residual curing stress in stages, which improves the defects of stress concentration and uneven cross-linking of internal and external parts in conventional single curing, and obtains a finished protective coating with stable structure and uniform performance.

[0032] The segmented dosage is precisely adapted to the 25μm coating structure, with low-dose surface shaping and high-dose deep cross-linking, which is consistent with the energy penetration characteristics of EB curing.

[0033] Example 2: This embodiment is based on the basic system of Example 1. It adopts the single variable optimization principle, only adjusting the ratio of the two resins and increasing the proportion of fluorinated modified acrylic resin. While retaining the advantages of high adhesion and high toughness of epoxy polyester resin, it maximizes the stain resistance and weather resistance characteristics of low surface energy of fluorinated resin.

[0034] The remaining compound systems, independent components, and basic process parameters are completely consistent with those in Example 1, strictly ensuring the rigor and comparative validity of the single-variable experiment.

[0035] The raw material components in this embodiment are detailed as follows: the compounding ratio, dosage, and compounding method of the crosslinking accelerator (1.18 parts), reactive diluent (9.87 parts), and nanocomposite filler (6.91 parts) in the compounded components are exactly the same as those in Example 1. After adjustment, the basic components are 71.22 parts of JF806 perfluorinated modified acrylic resin, 15.83 parts of CY328 epoxy modified saturated polyester resin, and 0.79 parts of BYK333 polyether modified silicone leveling agent.

[0036] The specific process adjustments for this embodiment are as follows: Because the high-fluorine resin has low polarity and weak interfacial compatibility, the resin premixing time was extended, and the mixture was stirred at 1200 rpm for 20 minutes at room temperature to ensure full integration and compatibility of the high and low polarity resins, completely eliminating the risk of interfacial stratification and phase separation. After adding the compounded reactive diluent, the mixture was stirred for another 10 minutes. The remaining filler dispersion, coating, gradient curing process parameters, and nitrogen inert atmosphere conditions were completely consistent with those in Example 1.

[0037] This embodiment optimizes the resin ratio and relies on the synergistic effect of high-fluorine resin's stain and weather resistance and epoxy polyester resin's adhesion and toughening properties to balance the stain and weather resistance of high-fluorine resin with the system's adhesion performance.

[0038] Example 3: This embodiment is based on the basic system of Example 1, and follows the principle of single variable. It only optimizes the ratio and total filling amount of dual-size nanofillers to enhance the dual synergistic effect of micropore filling and macro-medium barrier, and further improves the coating density, surface hardness and acid and alkali corrosion resistance. The resin ratio, additive compounding and diluent compounding system are consistent with those of Example 1.

[0039] The detailed list of raw material components in this embodiment is as follows: The proportions and amounts of the crosslinking accelerator (1.18 parts) and reactive diluent (9.87 parts) in the compounded components are completely consistent with those in Example 1. The basic components are 56.32 parts of JF806 perfluorinated modified acrylic resin, 23.31 parts of CY328 epoxy modified saturated polyester resin, and 0.79 parts of BYK333 polyether modified silicone leveling agent.

[0040] The total amount of the optimized nanocomposite filler compound system was increased to 10.53 parts, which was composed of 8.62 parts of 30nm fumed silica and 1.91 parts of 50nm zirconium oxide in a layered compounding process.

[0041] Small-particle-size fillers precisely fill the micropores formed by resin cross-linking, blocking the media penetration channels; large-particle-size fillers construct a stable, wear-resistant, and corrosion-resistant macroscopic protective skeleton to resist external friction and chemical erosion. The two nested together form a dense three-dimensional protective structure that cannot be achieved by a single filler.

[0042] The specific process adjustments in this embodiment are as follows: In response to the characteristics of high-filling-content nanofillers being prone to agglomeration and uneven dispersion, the high-speed dispersion time is extended to 35 minutes to ensure uniform nesting and dispersion of dual-particle-size fillers and to stably form a hierarchical dense protective structure.

[0043] The remaining mixing, coating, and gradient curing processes are completely consistent with those in Example 1.

[0044] This embodiment optimizes the ratio of dual-particle-size fillers, relying on the synergistic effect of dense pore filling by small-particle-size fillers and reinforcement by large-particle-size skeletons, to significantly reduce the micro-porosity of the coating, enhance the medium barrier ability and mechanical protection performance, and achieve a simultaneous improvement in multiple properties such as corrosion resistance, hardness and stain resistance that cannot be achieved by a single filler system.

[0045] Example 4: This embodiment is based on the basic system of Example 1. It adopts the principle of single variable to optimize the total amount of compound additives and compound diluents, improves the interfacial wettability, liquid leveling and high-speed coating adaptability of the multi-component compound system, and solves the coating defect problem in industrial continuous production. The ratio of core resin system and filler system remains unchanged.

[0046] The raw material components in this embodiment are detailed as follows: the compound ratio is fixed and the total amount is optimized. The crosslinking accelerator is maintained at a 1:1 compound ratio and the total amount is increased to 1.97 parts; the reactive diluent is maintained at a 2:1 compound ratio and the total amount is increased to 15.74 parts.

[0047] The basic components are 49.28 parts of JF806 perfluorinated modified acrylic resin, 29.62 parts of CY328 epoxy modified saturated polyester resin, 6.91 parts of nanocomposite filler, and 1.18 parts of BYK333 polyether modified silicone leveling agent. The formulation ratio of the nanocomposite filler is completely consistent with that in Example 1.

[0048] All mixing, dispersion, coating, and gradient curing process parameters in this embodiment are consistent with those in Example 1. By combining the viscosity adjustment process of the compound diluent and the crosslinking activity enhancement function of the compound crosslinking aid, the viscosity and crosslinking reaction activity of the system are balanced, solving the industrial production problems of high viscosity, poor leveling and insufficient substrate wettability of high solids compound systems. This greatly improves the mass production stability of the product and optimizes the industrial processing adaptability of the system without sacrificing the protective performance, achieving a two-way synergistic balance between protective performance and processing performance.

[0049] Example 5: The raw material composition, compounding relationship, and details of independent components in this embodiment are as follows: In the fixed compounding system, the crosslinking accelerator is compounded in a 1:1 ratio, with a total dosage of 1.77 parts; the reactive diluent is compounded in a 2:1 ratio, with a total dosage of 11.83 parts. The basic components are 64.12 parts of JF806 perfluorinated modified acrylic resin, 19.73 parts of CY328 epoxy modified saturated polyester resin, and 0.98 parts of BYK333 polyether modified silicone leveling agent.

[0050] The total amount of the nanocomposite filler compound system is 8.80 parts, which is composed of 6.89 parts of 30nm fumed nano silica and 1.91 parts of 50nm nano zirconium oxide in a layered compounding process, representing the optimal ratio for balancing protective performance and processing performance.

[0051] The mixing, dispersion, and coating processes in this embodiment are the same as in Example 1. The curing process is specifically optimized for the optimal coupled formulation system to achieve deep adaptation and synergy between the formulation and the curing process.

[0052] The entire process maintains a nitrogen-inert low-oxygen atmosphere (oxygen content ≤100ppm), reducing the curing rate and extending the cross-linking reaction time to adapt to the cross-linking reaction characteristics of the multi-component compound system. The surface pre-curing dose is 20kGy, the deep curing dose is 30kGy, and the curing rate is adjusted to 6.5m / min.

[0053] Low-speed, precise gradient curing can release the internal residual stress during the cross-linking process of multi-component systems in stages, avoiding the defects of stress concentration in highly coupled systems. At the same time, it allows the internal and external resins, monomers, and fillers to fully cross-link and combine, improving the uniformity of cross-linking and long-term structural stability of the coating, and obtaining a high-density, low-stress, structurally stable, and high-performance finished coating.

[0054] Comparative Example 1: This comparative example uses a conventional single fluorinated acrylic resin film-forming system, completely eliminating the epoxy-modified polyester resin compounding. The total resin solid content is exactly the same as in Example 1, lacking the core dual-resin functional coupling and synergistic feature of this invention.

[0055] In terms of raw material composition and compounding relationship, the ratio, compounding method and dosage of crosslinking accelerator, reactive diluent, nanocomposite filler and leveling agent are completely consistent with those in Example 1. The basic components only retain 80.34 parts of JF806 perfluorinated modified acrylic resin, without epoxy modified polyester resin components, and the remaining components are consistent with those in Example 1.

[0056] The entire preparation process is completely consistent with that of Example 1, and the raw materials are all commercially available industrial-grade general-purpose raw materials.

[0057] Comparative Example 2: This comparative example uses a conventional single nanofiller reinforcement scheme in the industry, cancels the nano-zirconia compound, and only retains the single nano-silica filler. The total filler content is exactly the same as in Example 1, but it lacks the hierarchical protective coupling structure with nested particle sizes of the present invention.

[0058] In terms of raw material composition and compounding relationship, the ratio of dual compound system, dual resin matrix and leveling agent is the same as in Example 1, except that 6.91 parts of VKSP30 nano silica, an independent single filler component, are retained.

[0059] The entire preparation process is completely consistent with that of Example 1.

[0060] Comparative Example 3: This comparative example completely follows all the formulation components and compounding relationships of Example 1, only replacing the curing system, simulating the existing mainstream ultraviolet curing technology, adding 3 parts of 1173 photoinitiator (commonly available model), and using ultraviolet lamp curing instead of electron beam curing.

[0061] Preparation process curing energy 800mJ / cm 2 The process involves conventional air-based UV curing, with the remaining stirring, dispersion, and coating processes being consistent with Example 1. All raw materials are commercially available industrial-grade materials.

[0062] Comparative Example 4: In terms of raw material composition and compounding relationship, the ratio of the dual compound system, filler system and leveling agent is the same as in Example 1. Only the ratio of the two resins is adjusted to 29.61 parts of JF806 perfluorinated modified acrylic resin and 51.15 parts of CY328 epoxy modified saturated polyester resin. The resin ratio deviates from the optimal coupling range of the present invention, causing the system interface compatibility imbalance and performance mutual restriction problems.

[0063] The entire preparation process is completely consistent with that of Example 1.

[0064] Comparative Example 5: This comparative example represents the optimal combination of conventional technologies currently achievable in the field, demonstrating that even after conventional optimization methods in the prior art, it is still impossible to replicate the technical effects of this invention or solve the core technical problems of this invention.

[0065] This comparative example completely replicates the raw material types, total solids content, compound system ratio, basic processing conditions, and nitrogen inert atmosphere of the optimal formulation in Example 5. Only two core technical features of this invention are replaced: the dual-particle-size layered nanofiller compound is eliminated and replaced with a single nano-silica filler; the segmented gradient stress release curing process is eliminated and replaced with the industry-standard single-pass homogeneous high-energy electron beam curing process. The curing process uses a single uniform curing dose of 30 kGy and a curing rate of 6.5 m / min, without gradient segmented stress release treatment.

[0066] The KH570 pretreatment process for the nanocomposite filler in this invention is as follows: ethanol is used as the solvent, the amount of KH570 silane coupling agent is 1%-3% of the total mass of the nanocomposite filler, and the mixture is stirred at 300r / min-500r / min for 10min-15min at room temperature. After filtration, it is dried for later use. The nitrogen inert atmosphere adopts a three-stage replacement process, with a replacement pressure of 0.2MPa-0.4MPa and a nitrogen purity of ≥99.99%. After each replacement, the pressure is maintained for 3min-5min. After the replacement is completed, the oxygen content is detected online and is ≤100ppm.

[0067] Based on weight, the dosage range of each component in the coating of this invention is as follows: 1.18-1.97 parts of the crosslinking accelerator compound system, 9.87-15.74 parts of the reactive diluent compound system, 6.91-10.53 parts of the nanocomposite filler compound system, and 0.79-1.18 parts of the BYK333 polyether modified silicone leveling agent.

[0068] Performance testing and results analysis: Test conditions and test standards: After the preparation of all the coating samples in the embodiments and comparative examples of this invention, they were uniformly placed in a national standard constant temperature and humidity environment of 25°C and 50% for 24 hours for curing. This was done to eliminate residual curing stress generated during the coating preparation process, stabilize the cross-linked network structure of the coating, avoid test errors caused by differences in the preparation environment and insufficient curing, and ensure that the test data of all samples are parallel, reliable, and rigorously compared.

[0069] All performance tests of this invention were conducted in strict accordance with current national standardized testing specifications.

[0070] The surface stain resistance of the coating was tested according to the GB / T30693-2014 standard for the determination of water contact angle between plastic films and sheets. The water and oil contact angles of each sample were uniformly tested, and a 24-hour static stain wiping test was used to evaluate the long-term stain resistance. Soy sauce, carbon ink, and cooking oil were used as simulated contaminants, evenly applied to the coating surface, and after standing at room temperature for 24 hours, the surface was gently wiped with a clean, soft cloth. The residual stains on the coating surface were observed and accurately recorded. The acid and alkali corrosion resistance of the coating was tested using a medium immersion test. A 5% sodium hydroxide alkaline solution and a 5% dilute hydrochloric acid acidic solution were selected as standard corrosive media. All samples were continuously immersed at room temperature for 240 hours. The rate of change in sample mass before and after immersion was accurately measured, and the coating surface was observed throughout the process for any signs of damage, blistering, peeling, loss of gloss, discoloration, chalking, or other failure phenomena.

[0071] The interfacial adhesion between the coating and the substrate is strictly tested according to the GB / T9286-1998 standard for cross-cut adhesion test of paint and varnish films, and the adhesion level is determined by the cross-cut adhesion test.

[0072] The surface hardness of the coating is determined according to the standard GB / T6739-2006 for determining the hardness of paint and varnish by pencil method. The gradient hardness pencil uniform speed scratch test is used to accurately determine the pencil hardness level of the coating.

[0073] The long-term weather resistance and anti-aging stability of the coating were assessed by conducting a 300-hour continuous accelerated aging test using a UVA-340 ultraviolet aging lamp. After the test, the yellowing level, surface cracking, chalking, peeling and other defects of each sample were statistically analyzed, and the water contact angle retention rate of the coating was calculated to quantitatively evaluate the weather resistance and stability of the coating in long-term outdoor service.

[0074] The test results are shown in Table 1 below:

[0075] Results analysis: In terms of the synergistic coupling of the two resins, the low surface energy fluoropolymer is responsible for stain resistance and weather resistance, while the high polarity epoxy polyester resin is responsible for interfacial adhesion and film toughness. The combination of the two solves the inherent contradiction in this field that high stain resistance must be accompanied by low adhesion, as a single resin cannot achieve both high performance simultaneously. In terms of the synergistic structure of the dual-particle-size fillers, the 30nm filler microscopically fills pores and blocks permeation channels, while the 50nm zirconium oxide macroscopically constructs a wear-resistant and corrosion-resistant skeleton. The nested structure forms a dense protective network that a single filler cannot achieve, significantly reducing the porosity of the coating and the medium permeation rate. In terms of the synergistic function of the additives and diluents, the compounded diluent precisely controls the viscosity of the system to adapt to high-speed coating, and the compounded crosslinking aid improves the interfacial bonding force and overall crosslinking density of the resin, filler, and substrate, taking into account both industrial processing performance and coating structural performance. In terms of the synergistic adaptation of the formulation and process, the segmented gradient curing matches the differences in crosslinking reaction rates of the multi-component compound system, releasing residual stress step by step, solving the defects of uneven internal and external crosslinking and stress concentration cracking in single curing. The four units empower each other to form an inseparable synergistic whole.

[0076] The performance optimization of each variable embodiment precisely corresponds to the synergistic effect of a single synergistic unit, with rigorous and traceable logic: Example 2 optimizes the dual resin ratio, relying on the synergistic function of the resins to achieve a significant improvement in stain resistance and weather resistance without degradation of adhesion, breaking through the performance limit of conventional ratios; Example 3 optimizes the layered filler ratio, relying on structural synergy to significantly improve the coating density and mechanical hardness, and the improvement in acid and alkali corrosion resistance far exceeds the conventional superposition effect of increased filler volume, demonstrating a clear synergistic gain; Example 4 optimizes the additive dilution system, relying on processing synergy to solve the agglomeration and leveling defects of multi-component systems, achieving bidirectional optimization of no degradation of protective performance and significant improvement in processing performance; Example 5 integrates the optimal parameters to achieve complete adaptation of each unit, with each performance reaching an optimal balance, and the overall performance improvement is exponential, which can be achieved through unconventional parameter adjustments.

[0077] Five comparative examples fully verified the necessity of each synergistic unit. The absence of any coupling structure would lead to the collapse of the synergistic system and a significant decline in performance, without exception: Comparative Example 1 lacked the synergy of two resins, making it impossible to balance weather resistance and adhesion performance, resulting in a significant decrease in adhesion, corrosion resistance, and aging resistance; Comparative Example 2 lacked the synergy of hierarchical fillers, leaving only a single filler for simple filling, resulting in a large amount of residual micropores in the coating and a rapid decline in long-term protective performance; Comparative Example 3 replaced it with traditional UV curing, losing the core advantages of EB curing, which has no initiator and no oxygen inhibition, and the residual impurities in the system induced aging failure, resulting in a significant deterioration in weather resistance; Comparative Example 4 broke the precise coupling ratio of resins, resulting in an imbalance of interfacial compatibility and the occurrence of micro-phase separation. The results fully demonstrate that the high performance of this invention is the exclusive effect of multi-unit synergistic coupling, rather than the inherent performance of a single component.

[0078] Comparative Example 5, as an existing technology, lacks the synergistic effect of the hierarchical filler structure and gradient process stress release of the present invention, and therefore cannot construct a stable coating structure with low stress and high density. Its core performance is significantly lower than that of Example 5 of the present invention.

[0079] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. An EB-cured stain-resistant etch-resist decorative film coating, characterized by, By weight, it includes: 49.28-71.22 parts of JF806 perfluorinated modified acrylic resin, 15.83-29.62 parts of CY328 epoxy modified saturated polyester resin, 1.18-1.97 parts of crosslinking accelerator compound system, 9.87-15.74 parts of reactive diluent compound system, 6.91-10.53 parts of nanocomposite filler compound system, and 0. 79 parts - 1.18 parts; the coating is a solvent-free pure electron beam curing system, and no photoinitiator or thermal initiator is added during the curing process. The curing atmosphere is a nitrogen inert atmosphere with an oxygen content ≤100ppm, the electron beam acceleration voltage is 180keV, and the dry film thickness of the coating is 25μm±1μm; the coating adopts segmented gradient electron beam curing, with a surface pre-curing dose of 18kGy-20kGy and a deep curing dose of 25kGy-30kGy.

2. The coating of claim 1, wherein, The crosslinking accelerator compound system is composed of KH570 silane coupling agent and TMPDA aliphatic diacrylate in a weight ratio of 1:

1.

3. The coating of claim 1, wherein, The reactive diluent compound system is composed of PEA200 bifunctional polyether diacrylate and TMPTA trifunctional trimethylolpropane triacrylate in a weight ratio of 2:

1.

4. The coating of claim 1, wherein, The nanocomposite filler compounding system is composed of 30nm fumed silica nanoparticles and 50nm zirconium oxide nanoparticles in a layered compounding process.

5. The coating according to claim 1, characterized in that, The surface pre-curing rate is 8 m / min, and the deep curing rate is 6.5 m / min.

6. A method for preparing an EB-cured stain-resistant and corrosion-resistant decorative film coating, used to prepare the coating according to claim 1 or 2, characterized in that, Includes the following steps: (1) JF806 perfluorinated modified acrylic resin and CY328 epoxy modified saturated polyester resin were put into a closed stirred tank and premixed at room temperature at 1200 r / min for 15 min-20 min. The active diluent was added to the compound system and stirring was continued to obtain the composite resin matrix. (2) The nanocomposite filler compound system pretreated with KH570 was added to the composite resin matrix in batches and dispersed by high-speed stirring at 1800r / min for 25min-35min. The compound system of BYK333 polyether modified organosilicon leveling agent and crosslinking accelerator was added in sequence and stirred to obtain the coating liquid. (3) The coating liquid is applied to the PET decorative film substrate by roller coating process, and the dry film thickness is controlled to be 25μm±1μm; (4) Segmented gradient electron beam curing was carried out in a nitrogen inert atmosphere with oxygen content ≤100ppm. The electron beam acceleration voltage was 180keV. The surface pre-curing dose was 18kGy-20kGy and the curing rate was 8m / min. The deep curing dose was 25kGy-30kGy and the curing rate was 6.5m / min. The finished coating was obtained by cooling at room temperature. The KH570 pretreatment is as follows: using ethanol as solvent, the amount of KH570 silane coupling agent is 1%-3% of the total mass of the nanocomposite filler, stirring at 300r / min-500r / min at room temperature for 10min-15min, and then filtering and drying before use; The nitrogen inert atmosphere is produced by a three-stage replacement process, with a replacement pressure of 0.2MPa-0.4MPa, a nitrogen purity of ≥99.99%, and a pressure holding time of 3-5 minutes for each replacement. After replacement, the oxygen content is measured online to be ≤100ppm.

7. The preparation method according to claim 6, characterized in that, In step (1), when the amount of JF806 perfluorinated modified acrylic resin is 71.22 parts, the premixing time is 20 min.

8. The preparation method according to claim 6, characterized in that, In step (2), when the amount of nanocomposite filler compound system is 10.53 parts, the high-speed stirring time is 35 min.

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