UV-LED cured refinishing paint as well as preparation method and application thereof

Abstract

The invention discloses UV-LED cured refinishing paint as well as a preparation method and application thereof, and belongs to the technical field of paint. The refinishing paint provided by the invention is prepared from the following raw materials in percentage by mass: 35-60% of resin; 5-30% of a filler; 3-10% of a photoinitiator; the resin comprises alicyclic acrylic resin, urethane acrylate resin and amine modified polyester acrylic resin; the filler comprises an anti-rust filler; the antirust filler comprises at least one of zinc phosphate, modified zinc phosphate and modified aluminum triphosphate. The refinishing paint provided by the invention has the advantages of being high in curing speed, excellent in adhesive force on bare steel, rusted steel and old paint films, good in salt mist resistance and weather resistance, good in mechanical property, environment-friendly, solvent-free and the like. The invention also provides a preparation method and application of the refinishing paint.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and in particular to a UV-LED cured repair paint and a preparation method and application thereof. Background Art

[0002] Steel structures are prone to local damage such as scratches, bumps, and rust during transportation, installation, and use, requiring quick and efficient repairs to restore their protective performance and appearance.

[0003] In traditional technology, the repair paint commonly used for steel structures is mainly solvent-based, and its curing methods mainly include thermal curing and UV curing. These repair paints have certain limitations. Specifically, solvent-based repair paints contain a large amount of VOC, are not environmentally friendly, and cure slowly (depending on solvent volatilization and oxidative polymerization), requiring a long wait time, affecting construction efficiency; and curing is greatly affected by temperature and humidity. Thermally curing repair paints have high energy consumption, and it is difficult and uneven to heat large or complex components; they are not suitable for rapid on-site repairs. Ordinary UV-curing repair paints usually require the use of mercury lamps. Traditional mercury lamp light sources have high energy consumption, high heat generation, short lifespan, contain mercury and are not environmentally friendly; the light intensity distribution is uneven; and the curing effect on complex shapes (shadow areas) is poor.

[0004] In order to solve the above problems, the industry has developed UV-LED coatings to facilitate the surface repair of steel structures, but the above coatings still have obvious limitations. Specifically, existing UV-LED coatings are mostly used for flat substrates (such as wood, plastic, and paper). When applied to rough, porous, complex-shaped steel structures that often have rust or old paint films, the following key problems exist: Insufficient adhesion: It is difficult to achieve excellent initial adhesion and long-term durability (salt spray, humidity and heat resistance) on steel substrates (especially surfaces with a certain amount of rust or old paint films); Poor pigment dispersion and hiding power: Pigments (especially dark pigments) strongly absorb UV light, affecting deep-layer curing efficiency, making it difficult to achieve complete curing and obtain good hiding power under low-intensity UV-LED; Large volume shrinkage and internal stress: Rapid curing may lead to large volume shrinkage and generate internal stress, which affects the adhesion and flexibility of the coating to complex substrates; Poor workability: The viscosity needs to be suitable for scraping, brushing, or small-area spraying, and it must be able to wet rough surfaces well and fill minor defects; Poor weather resistance and protection: As a repair paint, it needs to have good weather resistance (UV aging resistance), corrosion resistance (salt spray and chemical resistance), and mechanical properties (hardness, wear resistance, and impact resistance).

[0005] Therefore, a new type of repair paint for steel structures is provided to improve the performance of traditional technologies in terms of environmental protection, energy consumption, curing speed, suitability for steel structure repair, adhesion, hiding power, flexibility and long-term protection. Summary of the Invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention provides a UV-LED-cured repair paint with advantages such as fast curing speed (seconds to minutes), excellent adhesion to bare steel, rusted steel, and old paint films, good salt spray and weather resistance, excellent mechanical properties, and environmentally friendly solvent-free properties. It is suitable for rapid on-site repair of steel structures.

[0007] The invention also provides a preparation method of the repair paint.

[0008] The present invention also provides a method for repairing a steel structure using the repair paint.

[0009] According to an embodiment of the first aspect of the present invention, a UV-LED-cured repair paint is provided. The raw materials for preparing the repair paint include, by mass percentage:

[0010] Resin 35-60%;

[0011] Filler 5-30%;

[0012] Photoinitiator 3-10%;

[0013] The resin includes alicyclic acrylic resin, polyurethane acrylate resin and amine-modified polyester acrylic resin;

[0014] The filler includes an anti-rust filler;

[0015] The anti-rust filler includes at least one of zinc phosphate, modified zinc phosphate, aluminum phosphate and modified aluminum tripolyphosphate.

[0016] The repair paint according to the embodiment of the present invention has at least the following beneficial effects:

[0017] (1) The repair paint provided by the present invention is specially optimized for UV-LED light sources (365-405nm), and can be completed within seconds to minutes. Drying and drying (depending on light intensity and film thickness) greatly improves the repair efficiency and is suitable for rapid on-site construction.

[0018] UV-LED light source curing has low energy consumption (more than 70% lower than mercury lamp), no mercury pollution, and low heat generation; the light source used in the present invention has a long service life (>20,000 hours) and is ready for use immediately after opening;

[0019] Due to the above-mentioned curing speed, the repair paint provided by the present invention has a wide range of applications and is specially designed for local repair of steel structures (bridges, buildings, ships, pipelines, storage tanks, equipment, etc.). It is particularly suitable for on-site repair of large components that require rapid restoration and protection and are difficult to move or heat.

[0020] (2) In the repair paint provided by the present invention, the alicyclic acrylic resin provides excellent adhesion (especially to metal), hardness, and chemical resistance; the polyurethane acrylate resin provides excellent flexibility, wear resistance, impact resistance, and weather resistance; and the amine-modified polyester acrylic resin provides excellent surface dryness. Combining these three resins with a photoinitiator can achieve excellent initial adhesion and long-term durable adhesion (verified by cross-hatch and pull-off tests) on bare steel, slightly rusted steel, and various old paint films (epoxy, polyurethane, etc.).

[0021] (3) The repair paint provided by the present invention uses selected high-efficiency anti-rust fillers and combines them with a dense paint film (the effect of resin and photoinitiator), giving the resulting coating excellent salt spray resistance (>500 hours), moisture and heat resistance, chemical resistance and good weather resistance.

[0022] (4) The repair paint provided by the present invention can obtain a moderate viscosity by preparing a combination of raw materials, making it suitable for scraping and brushing; it has good wetting and leveling properties and can effectively cover rough surfaces and minor defects; the pigment filler is stably dispersed, has strong covering power, and the paint film is flat and smooth.

[0023] (5) The repair paint provided by the present invention can provide good hardness (pencil hardness ≥ HB), flexibility (axial bending ≤ 2 mm), wear resistance and impact resistance through a balanced resin system.

[0024] (6) The repair paint provided by the present invention does not require the addition of additional solvents and is excellent in environmental protection.

[0025] According to some embodiments of the present invention, the mass ratio of the alicyclic acrylic resin, the polyurethane acrylate resin, and the amine-modified polyester acrylic resin is 20-30:10-25:5-15. The mass ratio of the alicyclic acrylic resin to the polyurethane acrylate resin is 1-2:1, for example, about 1.5:1 or about 1.8:1; and the mass ratio of the polyurethane acrylate resin to the amine-modified polyester acrylic resin is 1:0.5-1, for example, about 1:0.6, 1:0.7, 1:0.8, or about 1:0.9.

[0026] According to some embodiments of the present invention, the functionality of the alicyclic acrylic resin is 2 or 3. The above functionality selection can increase the crosslinking density and curing speed, and can balance the flexibility.

[0027] According to some embodiments of the present invention, the viscosity of the alicyclic acrylic resin is 800 to 2000 mPa·s (25° C.), thereby providing a repair paint with good workability.

[0028] According to some embodiments of the present invention, the alicyclic ring of the alicyclic acrylic resin includes a cyclohexane skeleton. Thus, the obtained repair paint has excellent weather resistance.

[0029] According to some embodiments of the present invention, the polyurethane acrylate resin includes an aliphatic polyurethane acrylate resin, which, when combined with the alicyclic acrylic resin, can significantly balance the hardness, flexibility, and adhesion of the paint film formed by the resulting repair paint.

[0030] According to some embodiments of the present invention, the mass percentage of the resin in the raw materials for preparing the repair paint is 45-55%, for example, about 48%, 50% or about 52%.

[0031] According to some embodiments of the present invention, the raw materials used to prepare the repair paint also include a reactive diluent. During the preparation and use of the repair paint, the reactive diluent has the function of adjusting viscosity and improving workability. However, during the curing process, the reactive diluent participates in the curing reaction, thus preventing the production of significant amounts of VOC residues.

[0032] According to some embodiments of the present invention, the reactive diluent includes at least one of tripropylene glycol diacrylate (TPGDA), 1,6-hexanediol diacrylate (HDDA), hydroxyethyl methacrylate (HEMA) and isobornyl acrylate (IBOA).

[0033] According to some embodiments of the present invention, the reactive diluent is a mixture of at least one of tripropylene glycol diacrylate and 1,6-hexanediol diacrylate and at least one of hydroxyethyl methacrylate and isobornyl acrylate.

[0034] According to some embodiments of the present invention, the reactive diluent is a mixture of propylene glycol diacrylate (CAS: 42978-66-5) and isobornyl acrylate (CAS: 5888-33-5). The former has low viscosity and significantly adjusts viscosity, while the latter enhances adhesion and has a low shrinkage effect.

[0035] According to some embodiments of the present invention, the mass ratio of tripropylene glycol diacrylate to isobornyl acrylate is 1 to 1.5:1, for example, about 1.2:1, 1.3:1, or about 1.4:1.

[0036] According to some embodiments of the present invention, the reactive diluent accounts for 10-30% by mass of the raw materials for preparing the repair paint, for example, about 15%, 20% or about 25%.

[0037] According to some embodiments of the present invention, the photoinitiator includes an acylphosphine oxide initiator and an α-aminoketone initiator. When the two are matched, they can efficiently match UV-LED light sources (main wavelengths of 365nm, 385nm, 395nm, 405nm). It has a good effect on deep curing of colored (especially dark) paint films and complex substrates. Specifically, the former is sensitive to long-wave UV, can match LED, and has excellent deep and surface curing capabilities; in addition, the former has a high compatibility with amine-modified polyester acrylic resin, can significantly reduce the oxygen inhibition effect, and improve the surface crosslinking density and surface curing speed of the paint film; the latter can enhance surface curing; after the two are combined synergistically, it can ensure that the system has UV-LED curing ability, and the surface and deep curing performance are very excellent.

[0038] According to some embodiments of the present invention, the acylphosphine oxide initiator includes at least one of TPO (2,4,6-trimethylbenzoyl-diphenylphosphine oxide) or BAPO (bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide).

[0039] According to some embodiments of the present invention, the α-aminoketone initiator includes 907 (2-methyl-1-(4-methylthiophenyl)-2-morpholinyl-1-propanone).

[0040] According to some embodiments of the present invention, the mass ratio of the acylphosphine oxide initiator to the α-aminoketone initiator is 2-6:0.5-3. For example, it can be 2-3:1, and more specifically, it can be about 2.5:1 or about 2.7:1.

[0041] According to some embodiments of the present invention, the mass percentage of the photoinitiator in the raw materials for preparing the repair paint is 4-7%, for example, about 4.5%, 5%, 5.5%, 6% or about 6.5%.

[0042] In the rust-proof filler, the modified zinc phosphate and modified aluminum tripolyphosphate are obtained by surface-modifying zinc phosphate and aluminum tripolyphosphate, respectively, so as to make them applicable to water-based coatings.

[0043] According to some embodiments of the present invention, the rust-proof filler includes zinc phosphate and modified aluminum tripolyphosphate. The former is environmentally friendly and a commonly used rust-proof filler; when combined with the latter, it provides excellent salt spray resistance. In the refinish paint system provided by the present invention, the use of this combination of rust-proof fillers can also improve the uniformity of the rust-proof filler dispersion within the system.

[0044] According to some embodiments of the present invention, the mass ratio of zinc phosphate to modified aluminum tripolyphosphate is 0.8 to 1.2:1, for example, about 1:1.

[0045] According to some embodiments of the present invention, the filler further includes at least one of a color filler and a thixotropic filler.

[0046] According to some embodiments of the present invention, the filler includes a color filler; the color filler includes at least one of rutile titanium dioxide, an iron oxide-based color filler, phthalocyanine blue, and phthalocyanine green. The present invention does not impose strict restrictions on the type of color filler. In actual production, a color filler with high hiding power, low oil absorption, and good dispersion stability can be selected based on color requirements. Furthermore, in actual production, the color filler is typically used in the form of a corresponding color paste, and subsequent weight measurements are based on the weight of the color paste.

[0047] According to some embodiments of the present invention, the filler includes a thixotropic filler, and the thixotropic filler includes fumed silica, thereby improving the thixotropic properties and thus improving the anti-sagging and anti-settling properties of the resulting repair paint.

[0048] According to some embodiments of the present invention, the mass ratio of the color filler, the anti-rust filler, and the thixotropic filler is 1-1.5:1:0.05-0.1. The mass ratio of the color filler to the anti-rust filler is 1.2:1 or approximately 1.3:1; and the mass ratio of the anti-rust filler to the thixotropic filler is 1:0.06, 1:0.07, or approximately 1:0.08.

[0049] According to some embodiments of the present invention, the filler accounts for 20-30% by mass of the raw materials for preparing the repair paint, for example, about 22%, 24%, 26% or about 28%.

[0050] According to some embodiments of the present invention, the raw materials for preparing the repair paint further include an additive.

[0051] According to some embodiments of the present invention, the auxiliary agent includes at least one of a dispersant, a leveling agent, a defoaming agent, an adhesion promoter, and a light stabilizer.

[0052] According to some embodiments of the present invention, the auxiliary agent includes a dispersant, which is a polymer dispersant, such as BYK-163. This ensures that the filler is stably dispersed and prevents sedimentation and flocculation.

[0053] According to some embodiments of the present invention, the auxiliary agent includes a leveling agent, and the leveling agent includes a silicone leveling agent, such as BYK-306. This can improve the wettability of the substrate (especially rusty or old paint films) and the leveling of the coating.

[0054] According to some embodiments of the present invention, the auxiliary agent includes a defoamer, and the defoamer includes a non-silicon defoamer, such as BYK-055, thereby preventing bubbles from being generated during production and construction.

[0055] According to some embodiments of the present invention, the auxiliary agent includes an adhesion promoter, and the adhesion promoter includes a silane coupling agent, such as KH570. This, in conjunction with the resin, can improve the wet adhesion of the repair paint to the metal substrate.

[0056] According to some embodiments of the present invention, the additive includes a light stabilizer, which includes a UV absorber; for example, Tinuvin 400. This light stabilizer, in synergy with the polyurethane acrylate resin, can significantly improve weather resistance and prevent yellowing and chalking of the paint film formed by the repair paint.

[0057] According to some embodiments of the present invention, the ratio of the dispersant, leveling agent, defoaming agent, adhesion promoter, and light stabilizer is 0.5-2: 0.1-0.8: 0.1-0.5: 0.5-2: 0.3-1. Specifically, the ratio of the dispersant, leveling agent, defoaming agent, adhesion promoter, and light stabilizer is 4-6: 1: 0.8-1.2: 3.5-4.5: 1-2.

[0058] According to some embodiments of the present invention, the mass percentage of the additive in the raw materials for preparing the repair paint is 1-5%, for example, about 1.5%, 2%, 2.5%, 3%, 3.5%, 4% or about 4.5%.

[0059] According to the above description, no additional solvent needs to be added to the repair paint provided by the present invention, and the VOC content of the repair paint can be reduced as much as possible.

[0060] According to an embodiment of the second aspect of the present invention, a method for preparing a repair paint is provided. The method comprises mixing raw materials for preparing the repair paint.

[0061] Since the preparation method adopts all the technical solutions of the repair paint of the above embodiment, it at least has all the beneficial effects brought by the technical solutions of the above embodiment.

[0062] The preparation method provided by the present invention has clear steps and can be implemented by using conventional coating production equipment (dispersion kettle, sand mill, paint mixing kettle), is easy to industrialize and has stable quality.

[0063] According to some embodiments of the present invention, the preparation method comprises the following steps:

[0064] S1. A portion of the active diluent, a dispersant, a defoamer and an adhesion promoter is stirred and dispersed;

[0065] S2. Under stirring, the mixture obtained in step S1 and the rust-proof filler, thixotropic filler are mixed and stirred, and then sanded;

[0066] S3. Under stirring, the mixture obtained in step S2 and the resin and the remaining reactive diluent are mixed and stirred continuously;

[0067] S4. Under stirring, the mixture obtained in step S3 and other additives are mixed;

[0068] S5. Under stirring, the mixture obtained in step S4 and the photoinitiator are mixed and stirred continuously;

[0069] S6. Mix the mixture obtained in step S5 and the color filler, and continue stirring.

[0070] According to some embodiments of the present invention, in step S1, the mass percentage of the portion of the reactive diluent to the total reactive diluent is 70-90%, for example, about 75%, 80% or about 85%.

[0071] According to some embodiments of the present invention, in step S1, the stirring and dispersing speed is 300-600 rpm. For example, it can be about 350 rpm, 400 rpm, 450 rpm, 500 rpm, or about 550 rpm. The stirring and dispersing time is not strictly limited, as long as the stirring is uniform.

[0072] According to some embodiments of the present invention, in step S2, the rotation speed of the stirring state is 300-600 rpm, for example, about 350 rpm, 400 rpm, 450 rpm, 500 rpm or about 550 rpm.

[0073] According to some embodiments of the present invention, in step S2, the rotation speed of the continued stirring is 1000-1500 rpm, for example, about 1100 rpm, 1200 rpm, 1300 rpm or about 1400 rpm.

[0074] According to some embodiments of the present invention, in step S2, the stirring is continued for 10 to 20 minutes, for example, about 12 minutes, 14 minutes, 16 minutes, or about 18 minutes, so that each portion of the raw materials can be initially moistened.

[0075] According to some embodiments of the present invention, in step S2, the sanding time is 20 to 40 minutes, for example, about 25 minutes, 30 minutes, or about 35 minutes.

[0076] According to some embodiments of the present invention, in step S2, after the sand grinding, the particle size of the obtained mixture is ≤30 μm. In actual production, the particle size of the mixture is taken as the standard, and the sand grinding time can be adjusted to achieve this particle size.

[0077] According to some embodiments of the present invention, in step S2, the sanding temperature is ≤50° C. If the temperature rises during the sanding process, cooling measures may be used.

[0078] According to some embodiments of the present invention, in step S3, the rotation speed of the stirring state is 500-800 rpm, for example, about 600 rpm or about 700 rpm.

[0079] According to some embodiments of the present invention, in step S3, the duration of the continuous stirring is 20 to 30 minutes, for example, about 22 minutes, 24 minutes, 26 minutes, or about 28 minutes. During this process, the rotation speed is maintained at 500 to 800 rpm, for example, about 600 rpm or about 700 rpm.

[0080] According to some embodiments of the present invention, in step S4, the rotation speed of the stirring state is 500-800 rpm, for example, about 600 rpm or about 700 rpm.

[0081] In step S4, after adding the auxiliary agents, each one is stirred for 5 to 10 minutes (for example, about 6 minutes or about 8 minutes) before adding another auxiliary agent. This can improve the mixing uniformity of the materials.

[0082] According to some embodiments of the present invention, in step S5, the rotation speed of the stirring state is 500-800 rpm, for example, about 600 rpm or about 700 rpm.

[0083] According to some embodiments of the present invention, in step S5, the duration of the continuous stirring is 30 to 45 minutes. For example, it can be about 32 minutes, 34 minutes, 36 minutes, 38 minutes, 40 minutes, or about 42 minutes. During this process, the rotation speed is maintained at 500 to 800 rpm. For example, it can be about 600 rpm or about 700 rpm.

[0084] According to some embodiments of the present invention, in step S5, the operating temperature is ≤ 35°C.

[0085] According to some embodiments of the present invention, step S5 is performed under light shielding or weak yellow light conditions.

[0086] According to some embodiments of the present invention, in step S6, the duration of the continuous stirring is 15 to 20 minutes, for example, about 16 minutes or about 18 minutes. During this process, the rotation speed is maintained at 500 to 800 rpm, for example, about 600 rpm or about 700 rpm.

[0087] According to some embodiments of the present invention, in step S6, the operating temperature is ≤ 35°C.

[0088] According to some embodiments of the present invention, the preparation method further includes defoaming and filtering after step S6. The defoaming method includes at least one of static defoaming and vacuum degassing. The filtration is performed using a filter with a mesh size of 100 to 200, for example, about 150 mesh.

[0089] According to some embodiments of the present invention, the preparation method further comprises packaging and sealing.

[0090] According to an embodiment of the third aspect of the present invention, a method for preparing a paint film is provided, comprising applying the repair paint on a substrate surface and performing UV-LED curing.

[0091] Since the method for preparing the paint film adopts all the technical solutions of the repair paint of the above embodiment, it at least has all the beneficial effects brought by the technical solutions of the above embodiment.

[0092] According to some embodiments of the present invention, the substrate comprises at least one of bare steel, corroded steel, and an old paint film. The old paint film may be made of epoxy, polyurethane, or the like. The paint films formed on the surfaces of these substrates exhibit excellent initial adhesion and long-term durable adhesion.

[0093] According to some embodiments of the present invention, the UV-LED curing time is 80 to 100 seconds. For example, it can be about 90 seconds. This fast curing speed facilitates outdoor and emergency repairs of steel structures.

[0094] According to some embodiments of the present invention, the wavelength range of the light source used for UV-LED curing is 365-405 nm.

[0095] Unless otherwise specified, the term “about” in the present invention actually means that the error is allowed to be within the range of ±2%, for example, about 100 actually means 100±2%×100.

[0096] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the present invention. DETAILED DESCRIPTION

[0097] The following will clearly and completely describe the concept and technical effects of the present invention in conjunction with the embodiments to fully understand the purpose, features and effects of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, other embodiments obtained by those skilled in the art without creative work are all within the scope of protection of the present invention.

[0098] In the description of the present invention, reference to terms such as "one embodiment," "some embodiments," "illustrative embodiments," "examples," "specific examples," or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the exemplary expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0099] Example 1

[0100] In this example, a UV-LED-cured repair paint was prepared. The specific raw materials are shown in Table 1. The preparation steps are as follows:

[0101] S1. Add part of the active diluent (monomer, accounting for 80% of the total amount), dispersant, defoamer, and adhesion promoter to the dispersion kettle and stir at a low speed of 600 rpm to mix evenly.

[0102] S2. While stirring at 600 rpm, slowly add the formulated amount of anti-rust pigment and thixotropic filler. After adding, increase the speed to 1200 rpm and stir for 15 minutes to initially wet the powder. Then, switch to the sand mill and grind for 30 minutes until the required fineness (≤30 μm) is achieved. During the grinding process, pay attention to controlling the temperature (≤50°C).

[0103] S3. The mixture obtained in step S2 was transferred to a paint mixing kettle; under low-speed stirring at 600 rpm, the formulated amount of resin and the remaining reactive diluent were slowly added and stirred for 25 min to ensure uniform mixing.

[0104] S4. Under low-speed stirring at 600 rpm, the formulated amount of leveling agent and light stabilizer (UV absorber) was added sequentially; each additive was stirred for 8 minutes to fully disperse;

[0105] S5. In the dark or under weak yellow light, slowly add the formulated amount of photoinitiator while stirring at 600 rpm. Continue stirring for 40 minutes after addition to ensure that the photoinitiator is completely dissolved and evenly dispersed. Keep the temperature below 35°C.

[0106] S6. Add the color paste to the mixture obtained in step S5 and continue stirring for 18 minutes to ensure that the color is fully and evenly dispersed. Control the temperature below 35°C.

[0107] S7. The mixture obtained in step S6 is allowed to stand for defoaming; then filtered through a 200-mesh sieve to obtain a UV-LED-cured repair paint; finally, the product is placed in a light-proof container and sealed for storage.

[0108] Example 2 and Comparative Examples 1 to 3 respectively prepared a UV-LED cured repair paint, which differed from Example 1 in that:

[0109] Some of the preparation raw materials are different, and the specific differences are shown in Table 1.

[0110] Table 1 Preparation materials of UV-LED cured repair paint in Examples and Comparative Examples (parts by mass)

[0111]

[0112] Test Case

[0113] This example tests the performance of the repair paints obtained in the examples and comparative examples. The specific test items, methods and results are shown in Table 2.

[0114] Table 2 Properties of the repair paints obtained in Examples and Comparative Examples

[0115]

[0116]

[0117] In Table 2, regarding the performance test of the paint film, the paint film acquisition method used is the same as the paint film acquisition method in the "Curing Condition", wherein the substrate used is rusted steel; before use, the substrate is simply polished to make its surface smooth.

[0118] Comparing the results of Examples 1 and 2, we can see that within the range provided by the present invention, the overall performance of the paint film produced by the resulting repair paint is good. However, the use of two photoinitiators achieves even better overall performance, demonstrating a significant synergistic effect between the photoinitiator and other ingredients, such as the resin.

[0119] By comparing the results of Example 1 and Comparative Examples 1 to 2, it can be seen that if the resin combination used is not within the scope provided by the present invention, the overall performance of the resulting paint film will be seriously deteriorated; this shows that in the repair paint provided by the present invention, the three resins have a significant synergistic effect, which has a significant improvement on the curing condition, salt spray resistance and aging resistance of the paint film.

[0120] Comparing the results of Example 1 and Comparative Example 3, it can be seen that if the repair paint does not contain an antirust filler in its raw materials, not only will the paint film's adhesion to the steel surface deteriorate, but its hardness, corrosion resistance, and aging performance will also be significantly degraded; in other words, effects beyond those of the antirust filler are produced. This demonstrates that in the repair paint system provided by the present invention, a significant synergistic effect occurs between the antirust filler and the other raw materials used in its preparation.

[0121] In summary, the present invention addresses the technical deficiencies of existing steel surface repair paints and provides a UV-LED curing coating designed specifically for steel structure repair. Through the synergistic effects between resins, between resins and photoinitiators, and between rust-proof fillers and other preparation raw materials, the repair paint has an extremely fast curing speed (under a UV-LED light source), excellent substrate adhesion (especially for rusted or old paint-filmed steel structures), good workability (such as scraping or brushing), sufficient hiding power, excellent corrosion resistance, weather resistance, and mechanical properties, while meeting environmental protection requirements (solvent-free). Due to the above advantages, the repair paint provided by the present invention is expected to be widely used in steel surface repair.

[0122] While the embodiments of the present invention have been described in detail above, the present invention is not limited to the embodiments described above. Various modifications may be made within the scope of knowledge possessed by a person skilled in the art without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof may be combined with one another unless there is a conflict.

Claims

1. A UV-LED cured repair paint, characterized in that The raw materials for preparing the repair paint include, by mass percentage: Resin 35-60%; Filler 5-30%; Photoinitiator 3-10%; The resin includes alicyclic acrylic resin, polyurethane acrylate resin and amine-modified polyester acrylic resin; The filler includes an anti-rust filler; The anti-rust filler includes at least one of zinc phosphate, modified zinc phosphate, aluminum tripolyphosphate and modified aluminum tripolyphosphate.

2. The repair paint according to claim 1, characterized in that The mass ratio of the alicyclic acrylic resin, the polyurethane acrylate resin and the amine-modified polyester acrylic resin is 20-30:10-25:5-15.

3. The repair paint according to claim 1, characterized in that The anti-rust filler includes zinc phosphate and modified aluminum tripolyphosphate; Preferably, the mass ratio of the zinc phosphate to the modified aluminum tripolyphosphate is 0.8 to 1.2:

1.

4. The repair paint according to claim 1, characterized in that The photoinitiator includes an acylphosphine oxide type initiator and an α-aminoketone type initiator.

5. The repair paint according to claim 4, characterized in that The mass ratio of the acylphosphine oxide initiator to the α-aminoketone initiator is 2-6:0.5-3.

6. The repair paint according to any one of claims 1 to 5, characterized in that The raw materials for preparing the repair paint also include a reactive diluent; Preferably, the reactive diluent comprises at least one of tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, hydroxyethyl methacrylate and isobornyl acrylate; Preferably, the mass percentage of the reactive diluent in the raw materials for preparing the repair paint is 10-30%.

7. The repair paint according to any one of claims 1 to 5, characterized in that The raw materials for preparing the repair paint also include additives; Preferably, the auxiliary agent includes at least one of a dispersant, a leveling agent, a defoamer, an adhesion promoter and a light stabilizer; Preferably, the mass percentage of the auxiliary agent in the raw materials for preparing the repair paint is 1 to 5%.

8. The repair paint according to any one of claims 1 to 5, characterized in that The filler further comprises at least one of a color filler and a thixotropic filler.

9. A method for preparing a repair paint according to any one of claims 1 to 8, characterized in that: The preparation method comprises mixing raw materials for preparing the repair paint.

10. A method for preparing a paint film, characterized in that: The method comprises coating the repair paint according to any one of claims 1 to 8 on the surface of a substrate and performing UV-LED curing.

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