A UV light-cured anticorrosive coating and a preparation method thereof

Abstract

The application discloses a kind of UV light curing anticorrosive paint and preparation method thereof, belong to functional coating technical field.The present application aims at solving the problems of existing UV anticorrosive paint coating brittleness, easy cracking, thick film construction exists oxygen block polymerization, surface curing incomplete.The coating comprises epoxy acrylate resin, polyurethane acrylate resin, active diluent, double curing silane coupling agent, amino modified graphene, photoinitiator and auxiliary agent by weight parts.Through the synergy of two key components, organic-inorganic interpenetrating network is constructed, and specific ratio of raw materials and step-by-step preparation process is used.The present application effectively overcomes the defect of oxygen block polymerization, makes the coating hard and tough balanced, and has excellent adhesion, and the corrosion propagation width is extremely low after 1500 hours of salt spray test, with the advantages of efficient curing and long-term corrosion protection.

Description

Technical Field

[0001] This invention belongs to the field of functional coatings technology, specifically relating to a UV-curable anti-corrosion coating and its preparation method. Background Technology

[0002] With its zero / low VOC emissions, ultra-high application efficiency, and excellent physicochemical properties, UV-curable coatings are gradually becoming a green alternative to traditional solvent-based anti-corrosion coatings in fields such as large steel structures, wind power equipment, and marine engineering. These applications require anti-corrosion coatings to not only cure quickly to adapt to the pace of factory and modular production, but also to have a reliable anti-corrosion life of several years or even decades.

[0003] However, traditional UV-cured anti-corrosion coatings have a fundamental technical flaw in achieving long-term heavy-duty corrosion protection. Their curing and film formation rely on the rapid free radical polymerization of acrylate functional groups, forming a polymer network with a high cross-linking density. While this network structure imparts high hardness and chemical resistance to the coating, it also results in high internal stress and a rigid yet brittle texture. When applied to large metal substrates, thermal expansion and contraction due to temperature changes, mechanical vibrations during transportation and installation, or external impacts can easily cause microcracks invisible to the naked eye to form in the brittle coating. These microcracks become rapid channels for the intrusion of corrosive media (water, oxygen, salt), bypassing the physical barriers of the anti-corrosion fillers in the coating and reaching the interface between the coating and the substrate. This leads to loss of coating adhesion and early corrosion of the substrate, shortening the coating's long-term protective mission.

[0004] Furthermore, a prevalent but often overlooked technical challenge exists in this field. UV coatings used for corrosion protection typically require thick layers (e.g., 80-150 μm) to ensure physical barrier effects. However, during UV curing, oxygen in the air has a strong quenching effect on free radicals, known as the oxygen inhibition effect. This makes it difficult for thick coatings to cure completely, often resulting in problems such as stickiness, low gloss, and insufficient hardness. This not only affects the appearance but also makes the coating surface susceptible to damage, becoming a weak link in the corrosion protection system. Therefore, how to solve the coating brittleness problem while overcoming the surface oxygen inhibition effect during thick film application, achieving a "comprehensive" coating solution, is key to promoting the breakthrough application of UV curing technology in the field of heavy-duty corrosion protection. This has urgent technical needs and significant market value. Summary of the Invention

[0005] The purpose of this invention is to overcome the aforementioned deficiencies of the prior art and provide a UV-curable anti-corrosion coating and its preparation method. This coating aims to solve the coating brittleness problem and elevate its anti-corrosion performance to a new level through the synergistic effect of two key raw materials, while simultaneously overcoming the technical challenge of surface oxygen inhibition.

[0006] The objective of this invention can be achieved through the following technical solutions: A UV-curable anti-corrosion coating, comprising the following components by weight: 25-40 parts of epoxy acrylate resin; 10-20 parts of polyurethane acrylate resin; 18-35 parts of reactive diluent; 2-9 parts of dual-curing silane coupling agent; 1-8 parts of amino-modified graphene; 4-8 parts of photoinitiator; 1.5-2.0 parts of auxiliary agent; The dual-curing silane coupling agent is a silane coupling agent with a photocurable unsaturated group at one end and a hydrolyzable silane group at the other end; the amino-modified graphene surface contains amino functional groups, which can chemically react with the silanol groups generated by the hydrolysis of the dual-curing silane coupling agent or form hydrogen bonds.

[0007] Furthermore, the UV-curable anti-corrosion coating comprises, by weight, the following components: 40 parts of epoxy acrylate resin; 15 parts of polyurethane acrylate resin; 30 parts reactive diluent; 5 parts of dual-curing silane coupling agent; Four parts of amino-modified graphene; 5 parts of photoinitiator; 1.5 parts of auxiliary agent.

[0008] Furthermore, the reactive diluent is a mixture of isoborneol acrylate and hexanediol diacrylate in a weight ratio of (10-25):(8-10).

[0009] Furthermore, the dual-curing silane coupling agent is 3-(methacryloyloxy)propyltrimethoxysilane, i.e., KH-570; the amino-modified graphene is prepared by surface amination of graphene with KH-550.

[0010] Furthermore, the photoinitiator is a mixture of photoinitiator 184 and photoinitiator TPO, with a weight ratio of (2-5):(2-3); the additives include leveling agents and defoamers.

[0011] Furthermore, the preparation method of the amino-modified graphene is as follows: dispersing graphene powder in anhydrous ethanol, adding aminopropyltriethoxysilane, refluxing at 50-90℃ for 4-8 hours, and obtaining the product after washing and drying.

[0012] As a further aspect of the present invention, a method for preparing a UV-curable anti-corrosion coating includes the following steps: (S1) Mix epoxy acrylate resin, polyurethane acrylate resin, reactive diluent and dual-curing silane coupling agent evenly to form mixed resin liquid A; (S2) Add amino-modified graphene and additives to the mixed resin liquid A, disperse and grind to a fineness of less than 15μm to obtain anti-corrosion color paste B; (S3) Add a photoinitiator to the anti-corrosion color paste B under light-protected conditions, stir evenly, filter and degas to obtain the UV-curable anti-corrosion coating.

[0013] Furthermore, in step (S1), the stirring speed is 200-400 rpm and the stirring time is 15-25 minutes; in step (S2), the dispersion speed is 1200-1800 rpm and the dispersion time is 30-60 minutes, and the slurry temperature is controlled below 40°C during the grinding process.

[0014] Furthermore, in step (S3), the photoinitiator is added in batches and mixed for 15-25 minutes under stirring conditions of 200-400 rpm; filtration is carried out using a 100-mesh filter, and the degassing time is 5-15 minutes; the resulting coating has a touch dry time of ≤10 seconds after UV curing, an adhesion grade of 0, a pencil hardness of 4H-5H, a flexibility of 3-5mm, and a scratch corrosion spread width of ≤0.5-1.5mm after 1500 hours of neutral salt spray testing.

[0015] The beneficial effects of this invention are: This invention discloses a UV-curable anti-corrosion coating and its preparation method, aiming to solve two major technical problems faced by existing UV-curable anti-corrosion coatings when applied in heavy-duty anti-corrosion fields: first, the high cross-linking density network leads to high coating brittleness and easy cracking, thus affecting the long-term anti-corrosion effect; second, in thick film construction, the surface is not fully cured due to oxygen inhibition effect, resulting in surface stickiness and performance degradation. This invention overcomes the above defects by introducing amino-modified graphene and a dual-curing silane coupling agent (KH-570), and enabling the two to produce a synergistic effect in a specific resin system, thus obtaining a UV-curable anti-corrosion coating with both physical and mechanical properties and corrosion resistance. The specific beneficial effects are mainly reflected in the following aspects: (1) Solve the problem of oxygen inhibition on thick film surfaces and achieve surface curing: Existing technology indicates that surface curing of thick UV coatings is an industry challenge. The effectiveness of this invention is demonstrated by comparing Example 2 with Comparative Example 1. In Example 2, after UV curing, the touch-dry time is less than or equal to 10 seconds, and the coating surface is dry and firm. In contrast, Comparative Example 1, which simply replaced 4 parts of "amino-modified graphene" in Example 2 with an equal amount of traditional anti-corrosion filler "zinc phosphate," had a surface drying time exceeding 60 seconds and the surface remained sticky.

[0016] Principle Analysis: This data demonstrates that amino-modified graphene plays a crucial role in inhibiting oxidation and polymerization in this system. During UV curing, oxygen in the air quenches photoradicals generated by the initiator, hindering the polymerization of the surface resin. In this invention, the amino groups (-NH2) on the graphene surface possess strong reducing and free radical scavenging capabilities, preferentially reacting with oxygen or peroxide radicals that penetrate the coating surface. This effectively consumes surface oxygen, providing a favorable polymerization environment for the carbon-center radicals generated by the photoinitiator, ensuring that the acrylate functional groups can also effectively and rapidly crosslink and cure on the coating surface. This fundamentally solves the problem of incomplete surface curing in traditional UV thick coatings, guaranteeing uniform high performance from the inside out.

[0017] (2) An "organic-inorganic interpenetrating network" coating with high adhesion, high hardness and excellent flexibility was constructed, overcoming the brittleness of traditional coatings: Traditional UV coatings are hard and brittle. This invention introduces a dual-curing silane coupling agent, KH-570, and combines it with flexible resins such as polyurethane acrylate (PUA) to construct a coating system that is both hard and tough.

[0018] A. Dual-curing silane coupling agent (KH-570) is the foundation for building high-performance networks: Comparative Example 3 was based on Example 2 except that KH-570 was removed. As a result, the coating adhesion dropped sharply from level 0 to level 2, the pencil hardness dropped from 4H to 2H, and although the flexibility was the same at 3mm, it failed in the salt spray test (corrosion spread > 5.0mm, severe blistering and rusting), indicating that its overall protective structure had collapsed.

[0019] Principle Analysis: KH-570 is a "dual-curing" molecular bridge. One end is a methacryloyloxy group, which can undergo free radical copolymerization with resins such as epoxy acrylate (EA) and polyurethane acrylate (PUA) under UV light, becoming part of an organic cross-linking network. The other end is a trimethoxysilyl group, which hydrolyzes into active silanol groups (-Si-OH) under ambient moisture. These silanol groups undergo dehydration condensation reactions to form a rigid inorganic "Si-O-Si" network; simultaneously, the silanol groups can also form strong chemical bonds (MO-Si) with hydroxyl groups on the surface of the metal substrate. This explains why the adhesion in Example 2 reaches grade 0, while the adhesion in Comparative Example 3, which lacks KH-570, is only grade 2. Therefore, KH-570, through both UV curing and moisture curing, forms an "organic-inorganic interpenetrating network (IPN)" structure in the coating, where organic and inorganic networks interpenetrate and chemical bonds are formed at the coating-substrate interface. This structure endows the coating with high hardness, high adhesion and excellent density.

[0020] B. A balance between hardness and flexibility is achieved: Examples 1, 2, and 3 demonstrate the performance changes under different formulation ratios. Example 2 (hardness 4H, flexibility 3mm) exhibits higher hardness than Example 1 (hardness 3H, flexibility 4mm) and better flexibility than Example 3 (hardness 5H, flexibility 5mm), achieving a balance between hardness and toughness. This is attributed to the proportions of rigid epoxy acrylate, flexible polyurethane acrylate, and the formed inorganic Si-O-Si network in the formulation, which improves the brittleness problem of traditional UV coatings.

[0021] (3) Chemical bonding between the anti-corrosion filler and the resin network was achieved, constructing a synergistic composite anti-corrosion barrier, which significantly improved the corrosion resistance: The biggest improvement of this invention lies in the synergistic effect of amino-modified graphene and KH-570, which "welds" the physical shielding filler into the coating network, achieving excellent anti-corrosion effect.

[0022] A. Surface modification is key to achieving chemical bonding: The comparison between Example 2 and Comparative Example 2 highlights the necessity of "amino modification" of graphene. Comparative Example 2 used unmodified graphene, which reduced its adhesion to level 1 and increased the salt spray scratch corrosion width to 2.0-3.0 mm, far worse than Example 2 (adhesion level 0, corrosion width ≤0.5 mm).

[0023] Principle Analysis: Unmodified graphene and resin matrix are merely physically blended, resulting in poor interfacial compatibility and a tendency to form defects. However, the amino-modified graphene in this invention has amino groups on its surface that can react with or form strong hydrogen bonds with the silanol groups generated after the hydrolysis of KH-570. This allows the graphene sheets to be firmly anchored within the organic-inorganic interpenetrating network via the KH-570 "bridge." This chemical bonding eliminates the weak interface between the filler and the matrix, resulting in a dense and integral coating.

[0024] B. Synergistic effects construct a corrosion-resistant barrier: Compared with all comparative examples, especially with the conventional anti-corrosion system Comparative Example 1 (corrosion width 3.5-4.5 mm) and Comparative Example 3 (corrosion width > 5.0 mm) which lacks key components, Example 2 shows better anti-corrosion performance in terms of salt spray resistance (corrosion width ≤ 0.5 mm after 1500 h, no abnormalities on the plate surface).

[0025] In summary, this invention constructs a three-in-one synergistic anti-corrosion system. First, KH-570 forms a highly adhesive and dense organic-inorganic interpenetrating network framework through dual curing. Second, amino-modified graphene not only solves the surface oxygen inhibition problem, but more importantly, it is chemically bonded to KH-570 through its surface amino groups, firmly "welded" into the network framework. Its excellent layered structure creates a "maze effect" in the coating, extending the penetration path of corrosive media. Finally, the entire dense composite coating, with filler and matrix chemically bonded, is firmly attached to the substrate surface through the chemical bonds formed between KH-570 and the metal substrate. The synergistic effect of these three components constructs an anti-corrosion coating that combines rapid curing, balanced hardness and toughness, good adhesion, and physical shielding properties. Detailed Implementation

[0026] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. 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 of ordinary skill in the art without creative effort are within the scope of protection of the present invention. Meanwhile, the specifications of the raw materials, reagents, or devices used in the following embodiments are as follows: (1) Epoxy acrylate resin (EA): Industrial grade, bisphenol A type, viscosity 100,000 mPa·s (60℃), double bond equivalent approximately 250 g / eq, supplier: Zhanxin Resin.

[0027] (2) Polyurethane acrylate resin (PUA): Hexafunctional aliphatic, industrial grade, viscosity 20,000 mPa·s (60℃), supplier: Sartoma Chemical.

[0028] (3) IBOOA: reactive diluent, industrial grade, purity ≥98%.

[0029] (4) Hexanediol diacrylate (HDDA): reactive diluent, industrial grade, purity ≥98%.

[0030] (5) Dual-curing silane coupling agent (KH-570): Chemical name 3-(methacryloyloxy)propyltrimethoxysilane, industrial grade, purity ≥97%.

[0031] (6) A-Modified Graphene (A-Graphene): Commercially available, or prepared by the following method: Disperse 10 parts by weight of graphene powder (sheet diameter <10 μm) in 200 parts by weight of anhydrous ethanol, and disperse in an ultrasonic cleaner for 30 minutes to form a uniform suspension. Transfer the suspension to a three-necked flask equipped with a reflux condenser, add 5 parts by weight of aminopropyltriethoxysilane (KH-550), and reflux at 78°C (boiling point of ethanol) for 6 hours with mechanical stirring. After the reaction is complete, allow it to cool naturally to room temperature, collect the product by filtration, and wash the filter cake three times with anhydrous ethanol to remove unreacted silane. Finally, place the filter cake in a vacuum oven at 80°C for 6 hours to dry, and then grind it into powder for later use.

[0032] (7) Photoinitiator 184: Chemical name 1-hydroxycyclohexylphenyl ketone, industrial grade.

[0033] (8) Photoinitiator TPO: Chemical name: trimethylbenzoyl-diphenylphosphine oxide, industrial grade.

[0034] (9) Leveling agent BYK-333: polyether modified polydimethylsiloxane, commercially available from BYK Chemical Company, Germany.

[0035] (10) Defoamer BYK-052: a solution of defoaming polymer, commercially available from BYK Chemical Company, Germany. Example 1

[0036] This embodiment provides a UV-curable anti-corrosion coating, the raw material components of which, by weight, include: 25 parts epoxy acrylate resin, 10 parts polyurethane acrylate resin, 25 parts isoborneol acrylate, 10 parts hexanediol diacrylate, 2 parts dual-curing silane coupling agent KH-570, 1 part amino-modified graphene, 5 parts photoinitiator 184, 3 parts photoinitiator TPO, 1 part leveling agent BYK-333, and 0.5 parts defoamer BYK-052.

[0037] The detailed preparation method is as follows: (S1) In a 1L reactor equipped with a stirrer, heater, and condenser, at room temperature (25°C), add 25 parts by weight of epoxy acrylate resin (EA), 10 parts by weight of polyurethane acrylate resin (PUA), 25 parts by weight of isobornyl acrylate (IBOA), 10 parts by weight of hexanediol diacrylate (HDDA), and 2 parts by weight of dual-curing silane coupling agent KH-570 sequentially. Start stirring at 300 rpm and continue stirring for 15 minutes to ensure that all resins and diluents are mixed evenly to form a transparent mixed resin liquid A.

[0038] (S2) Maintain the stirring state of the material in the mixing tank, increase the rotation speed to 1500 rpm, and slowly add 1 part by weight of amino-modified graphene (A-Graphene), 1 part by weight of leveling agent BYK-333, and 0.5 parts by weight of defoamer BYK-052. After the addition is complete, continue to disperse for 30 minutes to allow the filler and additives to be initially and evenly dispersed in the resin solution.

[0039] (S3) Pump the slurry obtained in step (S2) into a horizontal sand mill for grinding. The filling rate is 60%. Use zirconia beads with a diameter of 0.8-1.0 mm. Control the cooling water temperature of the grinding cylinder jacket so that the outlet slurry temperature is below 40℃. Circulate and grind until the fineness is less than 15μm when detected by a scraper fineness gauge to obtain anti-corrosion color paste B.

[0040] (S4) Transfer the anti-corrosion pigment B to a clean paint mixing tank. Under light-protected conditions, start the stirring at low speed (200 rpm) and add 5 parts by weight of photoinitiator 184 and 3 parts by weight of photoinitiator TPO in batches. Continue stirring for 15 minutes until the photoinitiator powder is completely dissolved and the system is a uniform black viscous liquid.

[0041] (S5) The final mixture is filtered through a 100-mesh filter to remove any impurities or undispersed particles. The filtrate is then subjected to vacuum degassing for 10 minutes to remove air bubbles introduced during the preparation process. Finally, the finished product is packaged into opaque polyethylene containers and sealed for storage, thus obtaining the UV-curable anti-corrosion coating of Example 1. Example 2

[0042] This embodiment provides a UV-curable anti-corrosion coating, the raw material components of which, by weight, include: 40 parts epoxy acrylate resin, 15 parts polyurethane acrylate resin, 20 parts isoborneol acrylate, 10 parts hexanediol diacrylate, 5 parts dual-curing silane coupling agent KH-570, 4 parts amino-modified graphene, 3 parts photoinitiator 184, 2 parts photoinitiator TPO, 1 part leveling agent BYK-333, and 0.5 parts defoamer BYK-052.

[0043] The detailed preparation method is as follows: (S1) In a 1L reactor equipped with a stirrer, heater, and condenser, at room temperature (25°C), sequentially add 40 parts by weight of epoxy acrylate resin (EA), 15 parts by weight of polyurethane acrylate resin (PUA), 20 parts by weight of isobornyl acrylate (IBOA), 10 parts by weight of hexanediol diacrylate (HDDA), and 5 parts by weight of dual-curing silane coupling agent KH-570. Start stirring at 300 rpm and continue stirring for 20 minutes to ensure that all resins and diluents are mixed evenly to form a transparent mixed resin liquid A.

[0044] (S2) Maintain the stirring state of the material in the mixing tank, increase the rotation speed to 1500 rpm, and slowly add 4 parts by weight of amino-modified graphene (A-Graphene), 1 part by weight of leveling agent BYK-333, and 0.5 parts by weight of defoamer BYK-052. After the addition is complete, continue to disperse for 45 minutes to allow the filler and additives to be initially and uniformly dispersed in the resin solution.

[0045] (S3) Pump the slurry obtained in step (S2) into a horizontal sand mill for grinding. The filling rate is 60%. Use zirconia beads with a diameter of 0.8-1.0 mm. Control the cooling water temperature of the grinding cylinder jacket so that the outlet slurry temperature is below 40℃. Circulate and grind until the fineness is less than 15μm when detected by a scraper fineness gauge to obtain anti-corrosion color paste B.

[0046] (S4) Transfer the anti-corrosion pigment B to a clean paint mixing tank. Under light-protected conditions, start the stirring at low speed (200 rpm) and add 3 parts by weight of photoinitiator 184 and 2 parts by weight of photoinitiator TPO in batches. Continue stirring for 20 minutes until the photoinitiator powder is completely dissolved and the system is a uniform black viscous liquid.

[0047] (S5) The final mixture is filtered through a 100-mesh filter to remove any impurities or undispersed particles. The filtrate is then subjected to vacuum degassing for 10 minutes to remove air bubbles introduced during the preparation process. Finally, the finished product is packaged into opaque polyethylene containers and sealed for storage, thus obtaining the UV-curable anti-corrosion coating of Example 2. Example 3

[0048] This embodiment provides a UV-curable anti-corrosion coating, the raw material components of which, by weight, include: 40 parts epoxy acrylate resin, 20 parts polyurethane acrylate resin, 10 parts isoborneol acrylate, 8 parts hexanediol diacrylate, 9 parts dual-curing silane coupling agent KH-570, 8 parts amino-modified graphene, 2 parts photoinitiator 184, 2 parts photoinitiator TPO, 1.2 parts leveling agent BYK-333, and 0.8 parts defoamer BYK-052.

[0049] The detailed preparation method is as follows: (S1) In a 1L reactor equipped with a stirrer, heater, and condenser, at room temperature (25°C), add 40 parts by weight of epoxy acrylate resin (EA), 20 parts by weight of polyurethane acrylate resin (PUA), 10 parts by weight of isobornyl acrylate (IBOA), 8 parts by weight of hexanediol diacrylate (HDDA), and 9 parts by weight of dual-curing silane coupling agent KH-570 sequentially. Start stirring at 300 rpm and continue stirring for 25 minutes to ensure that all resins and diluents are mixed evenly to form a transparent mixed resin liquid A.

[0050] (S2) Maintain the stirring state of the material in the mixing tank, increase the rotation speed to 1500 rpm, and slowly add 8 parts by weight of amino-modified graphene (A-Graphene), 1.2 parts by weight of leveling agent BYK-333, and 0.8 parts by weight of defoamer BYK-052. After the addition is complete, continue to disperse for 60 minutes to allow the filler and additives to be initially and uniformly dispersed in the resin solution.

[0051] (S3) Pump the slurry obtained in step (S2) into a horizontal sand mill for grinding. The filling rate is 60%. Use zirconia beads with a diameter of 0.8-1.0 mm. Control the cooling water temperature of the grinding cylinder jacket so that the outlet slurry temperature is below 40℃. Circulate and grind until the fineness is less than 15μm when detected by a scraper fineness gauge to obtain anti-corrosion color paste B.

[0052] (S4) Transfer the anti-corrosion pigment B to a clean paint mixing tank. Under light-protected conditions, start the stirring at low speed (200 rpm) and add 2 parts by weight of photoinitiator 184 and 2 parts by weight of photoinitiator TPO in batches. Continue stirring for 25 minutes until the photoinitiator powder is completely dissolved and the system is a uniform black viscous liquid.

[0053] (S5) The final mixture is filtered through a 100-mesh filter to remove any impurities or undispersed particles. The filtrate is then subjected to vacuum degassing for 10 minutes to remove air bubbles introduced during the preparation process. Finally, the finished product is packaged into opaque polyethylene containers and sealed for storage, thus obtaining the UV-curable anti-corrosion coating of Example 3.

[0054] Comparative Example 1 Setup method: The formulation and preparation method of Comparative Example 1 and Example 2 are exactly the same, except that 4 parts of "amino-modified graphene" are replaced with 4 parts of conventional "zinc phosphate" anti-corrosion filler.

[0055] Raw material composition (parts by weight): 40 parts epoxy acrylate resin, 15 parts polyurethane acrylate resin, 20 parts isoborneol acrylate, 10 parts hexanediol diacrylate, 5 parts dual-curing silane coupling agent KH-570, 4 parts zinc phosphate, 3 parts photoinitiator 184, 2 parts photoinitiator TPO, 1 part leveling agent BYK-333, and 0.5 parts defoamer BYK-052.

[0056] Preparation method: It is exactly the same as in Example 2, except that in step (S2), the addition of "amino-modified graphene" is replaced with the addition of "zinc phosphate", and finally a UV-curable anti-corrosion coating is obtained.

[0057] Comparative Example 2 Setup: The formulation and preparation method of Comparative Example 2 are exactly the same as those of Example 2, except that 4 parts of "amino-modified graphene" are replaced with an equal amount of 4 parts of "unmodified graphene".

[0058] Raw material composition (parts by weight): 40 parts epoxy acrylate resin, 15 parts polyurethane acrylate resin, 20 parts isoborneol acrylate, 10 parts hexanediol diacrylate, 5 parts dual-curing silane coupling agent KH-570, 4 parts unmodified graphene, 3 parts photoinitiator 184, 2 parts photoinitiator TPO, 1 part leveling agent BYK-333, and 0.5 parts defoamer BYK-052.

[0059] Preparation method: It is exactly the same as in Example 2, except that in step (S2), the addition of "amino-modified graphene" is replaced with the addition of "unmodified graphene", and finally a UV-curable anti-corrosion coating is obtained.

[0060] Comparative Example 3 Setup method: Comparative Example 3 and Example 2 have the same formulation and preparation method, except that 5 parts of "dual-curing silane coupling agent KH-570" are removed and its weight is replaced by reactive diluent "isobornyl acrylate (IBOA)".

[0061] Raw material composition (parts by weight): 40 parts epoxy acrylate resin, 15 parts polyurethane acrylate resin, 25 parts isoborneol acrylate, 10 parts hexanediol diacrylate, 4 parts amino-modified graphene, 3 parts photoinitiator 184, 2 parts photoinitiator TPO, 1 part leveling agent BYK-333, and 0.5 parts defoamer BYK-052.

[0062] Preparation method: It is exactly the same as in Example 2, except that "dual-curing silane coupling agent KH-570" is not added in step (S1), and the amount of IBOA added is 25 parts, and finally a UV-curable anti-corrosion coating is obtained.

[0063] Test Example 1 Performance tests were conducted on Examples 1-3 and Comparative Examples 1-3. The test process is as follows, and the test results are shown in Table 1: (I) Sample preparation and curing: The six coatings prepared in Examples 1-3 and Comparative Examples 1-3 were uniformly coated onto Q235 carbon steel plates (150mm × 75mm × 3mm) that had been sandblasted to Sa2.5 grade. A wire bar coater was used to control the dry film thickness to 100±5μm. The coated samples were placed on a conveyor belt and UV cured using a single high-pressure mercury lamp with a power of 120W / cm at a conveyor belt speed of 5m / min. Each sample was irradiated twice under the lamp. After curing, the samples were placed in a standard laboratory environment (temperature 25±2℃, relative humidity 50±5%) for 7 days to ensure sufficient moisture curing reaction before performance testing.

[0064] (II) Performance Testing Methods: 1. Surface curing performance test (verifying the antioxidant and polymerization inhibition effect): Test Method: Finger-touch surface drying time test. Immediately after the sample passes through the UV lamp for the second time, a stopwatch is started. The tester lightly touches the edge of the coating (non-test area) with their finger, applying 1N of pressure to the coating surface with a clean index fingertip every 5 seconds and immediately removing it. The shortest time required from complete curing to the point where no stickiness is felt on the finger is recorded. The shorter the time, the better the antioxidant and polymerization inhibition effect, and the more thorough the surface curing.

[0065] 2. Physical and mechanical property testing of the coating (verifying the balance between hardness and toughness): (1) Adhesion Test: According to GB / T 9286-1998 standard, use a cross-cut adhesion tester to make 10×10 1mm×1mm squares on the coating. The scratches must penetrate the coating to the substrate. After cleaning up the debris with a brush, firmly stick the specified 3M tape to the marked area, and then quickly peel off the tape at a 60° angle. Observe the area of ​​coating peeling off in the marked area and rate it from 0 to 5 (0 is the best, no peeling).

[0066] (2) Pencil Hardness Test: According to GB / T 6739-2006 standard, a set of Zhonghua brand high-grade drawing pencils (from 6B to 6H) were used. The pencils were sharpened into cylindrical leads and smoothed on sandpaper. The pencil was held at a 45° angle to the coated surface and pushed forward about 7.5N with a force of about 7mm. The hardest pencil grade that did not cause scratches on the coating was recorded.

[0067] (3) Flexibility Test: According to GB / T 1731-1993 standard, a shaft bending tester is used. A 0.3mm thick tinplate sample coated with paint (prepared in the same way as the steel plate), with the coated side facing outwards, is bent 180° along shafts with diameters decreasing from large to small (e.g., 10mm, 8mm...2mm, 1mm). The bent portion is observed with a magnifying glass, and the smallest shaft diameter (mm) at which the coating does not crack or peel off is recorded. The smaller the diameter, the better the flexibility.

[0068] 3. Coating corrosion resistance test (verifying the synergistic anti-corrosion effect): Neutral salt spray test: According to GB / T 1771-2007 standard. Use a sharp blade to make a scratch approximately 5cm long and deep to the substrate in the center of the sample. After sealing the edges with tape, place the sample at a 20° angle to the vertical in the salt spray test chamber. Continuously spray with a 5% NaCl solution at 35℃. Continue testing for 1500 hours. After the test, remove the sample and rinse with clean water. Gently scrape away the loose corrosion products at the scratch with a blade. Measure the total width of corrosion spread on both sides of the scratch and take the average value as the corrosion spread width (mm). Simultaneously observe and record the blistering and rusting conditions on the surface of the sample.

[0069] Table 1 Test Results Touch drying time (s) 10-15 ≤ 10 ≤ 10 >60 (Sticky surface) 10-15 ≤ 10 Adhesion (Grade) 0-1 0 0 0-1 1 2 Pencil hardness 3H 4H 5H 3H 3H 2H Flexibility (mm) 4 3 5 3 4 3 Salt spray test (1500h) Scratch corrosion spread (mm) 1.0-1.5 ≤ 0.5 0.8-1.2 3.5-4.5 2.0-3.0 > 5.0 Board surface condition No foaming No bubbling, no rust No foaming Small amount of foam Slight bubbling Severe blistering and extensive rust Analysis of the data in Table 1: (1) Determination of the optimal embodiment: Comparing Embodiments 1, 2, and 3, Embodiment 2 exhibits the best overall performance. It achieves rapid surface drying, top-level adhesion (Grade 0), and high hardness (4H) while maintaining excellent flexibility (3mm), and demonstrates superior protection with almost no corrosion expansion during a 1500-hour salt spray test. Embodiment 1 has acceptable performance but slightly weaker corrosion resistance; Embodiment 3, although having higher hardness, exhibits reduced flexibility and slightly inferior corrosion resistance compared to Embodiment 2, indicating that excessive functional filler may lead to defects in the network structure. This proves that the formulation of Embodiment 2 represents the optimal balance point for achieving the technical effects of this invention.

[0070] (2) Comparative Example 1 vs. Example 2 (verifying the overall effect of amino-modified graphene): The surface of Comparative Example 1 was severely sticky (>60s), which directly demonstrated that traditional zinc phosphate filler does not have the ability to resist oxidation and polymerization, highlighting the technical effect brought by amino-modified graphene in this invention. At the same time, its salt spray corrosion expansion width (3.5-4.5mm) is much larger than that of Example 2 (≤0.5mm), proving that the "chemically bonded composite barrier" constructed in this invention is far superior to the physical barrier of traditional fillers in terms of corrosion resistance.

[0071] (3) Comparative Example 2 vs. Example 2 (verifying the necessity of "surface modification"): The adhesion (level 1) and salt spray performance (corrosion spread 2.0-3.0 mm) of Comparative Example 2 (using unmodified graphene) were significantly inferior to those of Example 2. This is because unmodified graphene cannot chemically bond with the inorganic network formed by KH-570 and can only exist as a physical filler. Its weak interfacial bonding makes it a weak point for corrosive media penetration. This comparison proves that "surface modification" and subsequent "chemical bonding" are key to achieving the superior anti-corrosion performance of this invention and are one of the core improvements of this invention.

[0072] (4) Comparative Example 3 vs. Example 2 (verifying the necessity of "dual-curing silane coupling agent"): Although Comparative Example 3 (without KH-570) dries quickly due to the presence of amino-modified graphene, its adhesion is significantly reduced (level 2), its hardness is low (2H), and it fails rapidly, especially in salt spray testing (corrosion spread > 5.0 mm). This indicates that without KH-570, the system cannot form a robust organic-inorganic interpenetrating network, nor can graphene be "welded" into the network. The coating is merely a simple physical blend, brittle and porous, unable to provide effective long-term protection. This comparison demonstrates that dual-curing silane coupling agents are fundamental for constructing high-performance coatings and a prerequisite for achieving synergistic effects.

[0073] It should be noted that, in this document, terms such as “comprising,” “including,” or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus.

[0074] 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 variations 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 UV-curable anti-corrosion coating, characterized in that, By weight, it includes the following components: 25-40 parts of epoxy acrylate resin; 10-20 parts of polyurethane acrylate resin; 18-35 parts of reactive diluent; 2-9 parts of dual-curing silane coupling agent; 1-8 parts of amino-modified graphene; 4-8 parts of photoinitiator; 1.5-2.0 parts of auxiliary agent; The dual-curing silane coupling agent is a silane coupling agent with a photocurable unsaturated group at one end and a hydrolyzable silane group at the other end; the amino-modified graphene surface contains amino functional groups, which can chemically react with the silanol groups generated by the hydrolysis of the dual-curing silane coupling agent or form hydrogen bonds.

2. The UV-curable anti-corrosion coating according to claim 1, characterized in that, By weight, it includes the following components: 40 parts of epoxy acrylate resin; 15 parts of polyurethane acrylate resin; 30 parts reactive diluent; 5 parts of dual-curing silane coupling agent; Four parts of amino-modified graphene; 5 parts of photoinitiator; 1.5 parts of auxiliary agent.

3. The UV-curable anti-corrosion coating according to claim 1, characterized in that, The reactive diluent is a mixture of isoborneol acrylate and hexanediol diacrylate in a weight ratio of (10-25):(8-10).

4. The UV-curable anti-corrosion coating according to claim 1, characterized in that, The dual-curing silane coupling agent is 3-(methacryloyloxy)propyltrimethoxysilane, i.e., KH-570; the amino-modified graphene is prepared by surface amino modification of graphene with KH-550.

5. The UV-curable anti-corrosion coating according to claim 1, characterized in that, The photoinitiator is a mixture of photoinitiator 184 and photoinitiator TPO, with a weight ratio of (2-5):(2-3); the additives include leveling agents and defoamers.

6. The UV-curable anti-corrosion coating according to claim 1, characterized in that, The preparation method of the amino-modified graphene is as follows: graphene powder is dispersed in anhydrous ethanol, aminopropyltriethoxysilane is added, and the mixture is refluxed at 50-90℃ for 4-8 hours. After washing and drying, the graphene is obtained.

7. A method for preparing a UV-curable anti-corrosion coating as described in any one of claims 1-6, characterized in that, Includes the following steps: (S1) Mix epoxy acrylate resin, polyurethane acrylate resin, reactive diluent and dual-curing silane coupling agent evenly to form mixed resin liquid A; (S2) Add amino-modified graphene and additives to the mixed resin liquid A, disperse and grind to a fineness of less than 15μm to obtain anti-corrosion color paste B; (S3) Add a photoinitiator to the anti-corrosion color paste B under light-protected conditions, stir evenly, filter and degas to obtain the UV-curable anti-corrosion coating.

8. The preparation method according to claim 7, characterized in that, In step (S1), the stirring speed is 200-400 rpm and the stirring time is 15-25 minutes; in step (S2), the dispersion speed is 1200-1800 rpm and the dispersion time is 30-60 minutes, and the slurry temperature is controlled below 40℃ during the grinding process.

9. The preparation method according to claim 7, characterized in that, In step (S3), the photoinitiator is added in batches and mixed for 15-25 minutes under stirring conditions of 200-400 rpm; filtration is carried out using a 100-mesh filter, and the degassing time is 5-15 minutes; the resulting coating has a touch dry time of ≤10 seconds after UV curing, an adhesion grade of 0, a pencil hardness of 4H-5H, a flexibility of 3-5mm, and a scratch corrosion spread width of ≤0.5-1.5mm after 1500 hours of neutral salt spray testing.