A uv-led cured repair paint, its preparation method and application

Abstract

The application discloses a kind of UV-LED cured repair paint and its preparation method and application, belong to coating technical field.The preparation raw material of repair paint provided by the application includes: resin 35~60% by mass fraction;Filler 5~30%;Photoinitiator 3~10%;Resin includes alicyclic acrylic resin, polyurethane acrylate resin and amine modified polyester acrylate resin;The filler includes rust-proof filler;The rust-proof filler includes at least one of zinc phosphate, modified zinc phosphate and modified aluminum tripolyphosphate.The repair paint provided by the application has the advantages of fast curing speed, excellent adhesion on bare steel, rusted steel and old paint film, good salt spray resistance, good weather resistance, good mechanical properties, environmental protection and solvent-free.The application also provides the preparation method and application of the above-mentioned repair paint.

Description

Technical Field

[0001] This invention relates to the field of coating technology, and in particular to a UV-LED cured repair paint, its preparation method, and its application. Background Technology

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

[0003] Traditionally, solvent-based paints are commonly used for repairing steel structures, and their curing methods mainly include thermosetting and UV curing. These paints have certain limitations. Specifically, solvent-based paints contain high levels of VOCs, making them environmentally unfriendly; they cure slowly (relying on solvent evaporation and oxidative polymerization), requiring long waiting times and affecting construction efficiency; and their curing is greatly affected by temperature and humidity. Thermosetting paints are energy-intensive, difficult to heat large or complex components, and uneven in heating; they are not suitable for rapid on-site repairs. Ordinary UV-curing paints typically require mercury lamps, which are energy-intensive, generate a lot of heat, have a short lifespan, contain mercury, and are environmentally unfriendly; their light intensity distribution is uneven; and their curing effect is poor on complex shapes (shaded areas).

[0004] To address these issues, the industry has developed UV-LED coatings to facilitate the repair of steel structure surfaces; however, these coatings still have significant limitations. Specifically, existing UV-LED coatings are mostly used on 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 obtain excellent initial adhesion and long-term durability (salt spray resistance, damp heat resistance) on steel substrates (especially surfaces with some rust or old paint films); Poor pigment dispersion and hiding power: Pigments (especially dark pigments) have strong UV light absorption, affecting deep curing efficiency and making it difficult to achieve complete curing and good hiding power under low-intensity UV-LED light; Large volume shrinkage and internal stress: Rapid curing may lead to large volume shrinkage, generating internal stress, affecting the coating's adhesion and flexibility to complex substrates; Poor workability: The viscosity needs to be suitable for scraping, brushing, or small-area spraying, and it needs to be able to effectively wet rough surfaces 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 resistance, chemical resistance), and mechanical properties (hardness, abrasion resistance, impact resistance).

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

[0006] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a UV-LED curable repair paint, which has the advantages of fast curing speed (seconds to minutes), excellent adhesion to bare steel, rusted steel and old paint films, good salt spray resistance, good weather resistance, good mechanical properties, and being environmentally friendly and solvent-free, making it suitable for rapid on-site repair of steel structures.

[0007] The present invention also provides a method for preparing the above-mentioned repair paint.

[0008] The present invention also provides a method for repairing steel structures using the above-mentioned repair paint.

[0009] According to an embodiment of the first aspect of the present invention, a UV-LED curable repair paint is provided, wherein the raw materials for preparing the repair paint, by weight percentage, comprise:

[0010] Resin 35-60%;

[0011] Filler content: 5-30%;

[0012] Photoinitiator 3-10%;

[0013] The resins include alicyclic acrylic resins, polyurethane acrylate resins, and amine-modified polyester acrylic resins;

[0014] The filler includes rust-preventive filler;

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

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

[0017] (1) The repair paint provided by this invention is optimized for UV-LED light source (365~405nm), and can complete surface drying and hard drying in a few seconds to a few minutes (depending on light intensity and film thickness), which greatly improves repair efficiency and is suitable for rapid on-site construction;

[0018] The UV-LED light source is used for curing, which has low energy consumption (more than 70% lower than mercury lamps), no mercury pollution, and low heat generation; moreover, the light source used in this invention has a long service life (>20,000 hours) and can be used immediately after being turned on.

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

[0020] (2) In the repair paint provided by this invention, alicyclic acrylic resin provides excellent adhesion (especially to metals), hardness, and chemical resistance; polyurethane acrylate resin provides excellent flexibility, abrasion resistance, impact resistance, and weather resistance; and amine-modified polyester acrylate resin provides excellent surface drying properties. When the above three resins are combined with a photoinitiator, excellent initial adhesion and long-term durable adhesion can be obtained on bare steel, slightly rusted steel, and various old paint films (epoxy, polyurethane, etc.) (verified by cross-cut test and pull-off test).

[0021] (3) The repair paint provided by the present invention is made of carefully selected high-efficiency anti-rust filler and combined with a dense paint film (the role of resin and photoinitiator), which gives the resulting coating excellent salt spray resistance (>500 hours), damp heat resistance, chemical resistance and good weather resistance.

[0022] (4) The repair paint provided by the present invention can obtain a moderate viscosity by combining the raw materials, making it suitable for scraping and brushing; and has good wetting and leveling properties, which can effectively cover rough surfaces and minor defects; the pigments and fillers are dispersed stably, have strong hiding power, and the paint film is smooth and flat.

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

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

[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 acrylate resin is 20-30:10-25:5-15. Specifically, the mass ratio of the alicyclic acrylic resin to the polyurethane acrylate resin is 1-2:1; for example, it can be about 1.5:1 or about 1.8:1; the mass ratio of the polyurethane acrylate resin to the amine-modified polyester acrylate resin is 1:0.5-1; for example, it can be 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 alicyclic acrylic resin has a functionality of 2 or 3. This functionality selection can improve crosslinking density and curing speed, while also balancing flexibility.

[0027] According to some embodiments of the present invention, the viscosity of the alicyclic acrylic resin is 800–2000 mPa·s (25°C). Therefore, the resulting repair paint has excellent workability.

[0028] According to some embodiments of the present invention, the alicyclic structure of the alicyclic acrylic resin comprises a cyclohexane backbone. Therefore, the resulting repair paint exhibits excellent weather resistance.

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

[0030] According to some embodiments of the present invention, the resin accounts for 45-55% of the mass percentage of the raw materials for preparing the repair paint. Specifically, it may be about 48%, 50%, or about 52%.

[0031] According to some embodiments of the present invention, the raw materials for preparing the repair paint further include an active diluent. During the preparation and use stages of the repair paint, the active diluent functions to adjust viscosity and improve workability; however, during the curing process, the active diluent participates in the curing reaction, thus preventing significant VOC residue.

[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 at least one of tripropylene glycol diacrylate and 1,6-hexanediol diacrylate, mixed with 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 dipropylene glycol diacrylate (CAS: 42978-66-5) and isobornyl acrylate (CAS: 5888-33-5). The former has low viscosity and a significant effect on viscosity regulation, while the latter enhances adhesion and also 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. Specifically, it can be 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 used in the preparation of the repair paint. Specifically, it may be about 15%, 20%, or about 25%.

[0037] According to some embodiments of the present invention, the photoinitiator includes an acylphosphine oxide type initiator and an α-aminoketone type initiator. When combined, they can be efficiently matched with UV-LED light sources (dominant wavelengths 365nm, 385nm, 395nm, 405nm). This provides excellent deep curing effects for colored (especially dark) paint films and complex substrates. Specifically, the former is sensitive to long-wave UV light, can be matched with LEDs, and has excellent deep and surface curing capabilities; furthermore, the former has high compatibility with amine-modified polyester acrylic resin, which can significantly reduce oxygen inhibition effects and increase the crosslinking density and surface curing speed of the paint film surface; the latter can enhance surface curing; the synergistic combination of the two ensures that the system has UV-LED curing capability, and both surface and deep curing performance are 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-morpholino-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. Specifically, it can be 2–3:1; more specifically, it can be about 2.5:1 or about 2.7:1.

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

[0042] In the rust-preventive filler, the modified zinc phosphate and modified aluminum tripolyphosphate are respectively surface-modified zinc phosphate and aluminum tripolyphosphate, making them suitable for use in water-based coatings.

[0043] According to some embodiments of the present invention, the rust-inhibiting filler includes zinc phosphate and modified aluminum tripolyphosphate. The former has excellent environmental performance and is a commonly used rust-inhibiting filler; when combined with the latter, it provides excellent salt spray resistance. In the repair paint system provided by the present invention, the use of the above-mentioned combination of rust-inhibiting fillers can also improve the uniformity of the dispersion of the rust-inhibiting filler in 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, it can be approximately 1:1.

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

[0046] According to some embodiments of the present invention, the filler includes a color filler; the color filler includes at least one selected from rutile titanium dioxide, iron oxide-based color fillers, phthalocyanine blue, and phthalocyanine green. The present invention does not strictly limit 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 according to color requirements. Furthermore, in actual production, the color filler is usually used in the form of a corresponding color paste, and subsequent weighing is based on the weight of the color paste.

[0047] According to some embodiments of the present invention, the filler comprises a thixotropic filler; the thixotropic filler comprises fumed silica. This improves the thixotropic properties, thereby enhancing 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 rust-inhibiting filler, and the thixotropic filler is 1–1.5:1:0.05–0.1. Specifically, the mass ratio of the color filler to the rust-inhibiting filler is 1.2:1 or about 1.3:1; and the mass ratio of the rust-inhibiting filler to the thixotropic filler is 1:0.06, 1:0.07, or about 1:0.08.

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

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

[0051] According to some embodiments of the present invention, the additives include at least one of dispersants, leveling agents, defoamers, adhesion promoters, and light stabilizers.

[0052] According to some embodiments of the present invention, the additive includes a dispersant, which is a polymeric dispersant, such as BYK-163. This ensures stable dispersion of the filler and prevents sedimentation and flocculation.

[0053] According to some embodiments of the present invention, the additive includes a leveling agent, which includes an organosilicon leveling agent, specifically BYK-306. This improves the wetting properties of the substrate (especially rusty or old paint films) and the leveling properties of the coating.

[0054] According to some embodiments of the present invention, the additive includes a defoamer, which includes a non-silicone defoamer; specifically, it may be BYK-055. This prevents the generation of bubbles during production and construction.

[0055] According to some embodiments of the present invention, the additive includes an adhesion promoter, which includes a silane coupling agent; specifically, it may be KH570. This, in synergy 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 additives include light stabilizers, which include UV absorbers; specifically, Tinuvin 400. This, 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, defoamer, 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, defoamer, 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 additive accounts for 1 to 5% of the mass percentage of the raw materials used in preparing the repair paint. Specifically, it may be about 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, or about 4.5%.

[0059] As can be seen from the above description, the repair paint provided by the present invention does not require the addition of additional solvents, and can minimize the VOC content of the repair paint.

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

[0061] Since the preparation method employs all the technical solutions of the repair paint described in the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments. Furthermore,

[0062] The preparation method provided by this invention has clear steps and can be achieved using conventional coating production equipment (dispersion kettle, sand mill, paint mixing kettle), making it easy to industrialize and ensuring stable quality.

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

[0064] S1. Stir and disperse a portion of the reactive diluent, dispersant, defoamer, and adhesion promoter;

[0065] S2. Under stirring, the mixture obtained in step S1 is mixed with the rust-inhibiting filler and thixotropic filler and stirring is continued, followed by sand milling;

[0066] S3. While stirring, mix the mixture obtained in step S2 with the resin and the remaining reactive diluent, and continue stirring;

[0067] S4. While stirring, mix the mixture obtained in step S3 with other additives;

[0068] S5. While stirring, mix the mixture obtained in step S4 with the photoinitiator and continue stirring;

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

[0070] According to some embodiments of the present invention, in step S1, a portion of the reactive diluent accounts for 70-90% of the total mass of the reactive diluent. Specifically, it may be 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 approximately 350 rpm, 400 rpm, 450 rpm, 500 rpm, or approximately 550 rpm. The stirring and dispersing time is not strictly limited, as long as the mixture is stirred evenly.

[0072] According to some embodiments of the present invention, in step S2, the stirring speed is 300 to 600 rpm. For example, it can be approximately 350 rpm, 400 rpm, 450 rpm, 500 rpm, or approximately 550 rpm.

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

[0074] According to some embodiments of the present invention, in step S2, the duration of continued stirring is 10–20 minutes. Specifically, it can be approximately 12 minutes, 14 minutes, 16 minutes, or approximately 18 minutes. This allows the raw materials to be initially moistened in each part of the preparation process.

[0075] According to some embodiments of the present invention, in step S2, the grinding time is 20 to 40 minutes. For example, it can be about 25 minutes, 30 minutes, or about 35 minutes.

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

[0077] According to some embodiments of the present invention, in step S2, the temperature of the sand mill is ≤50°C. If the temperature rises during the sand milling process, cooling measures can be adopted.

[0078] According to some embodiments of the present invention, in step S3, the stirring speed is 500 to 800 rpm. For example, it can be about 600 rpm or about 700 rpm.

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

[0080] According to some embodiments of the present invention, in step S4, the stirring speed is 500 to 800 rpm. For example, it can be about 600 rpm or about 700 rpm.

[0081] In step S4, after adding each of the additives, stirring is required for 5-10 minutes (for example, approximately 6 minutes or 8 minutes) before adding another additive. This improves the uniformity of the mixing of the materials.

[0082] According to some embodiments of the present invention, in step S5, the stirring speed is 500-800 rpm. For example, it can be approximately 600 rpm or approximately 700 rpm.

[0083] According to some embodiments of the present invention, in step S5, the duration of continuous stirring is 30–45 minutes. Specifically, it can be approximately 32 minutes, 34 minutes, 36 minutes, 38 minutes, 40 minutes, or approximately 42 minutes. During this process, the rotation speed is maintained at 500–800 rpm. Specifically, it can be approximately 600 rpm or approximately 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 conditions of light shielding or weak yellow light.

[0086] According to some embodiments of the present invention, in step S6, the duration of continuous stirring is 15 to 20 minutes. Specifically, it can be about 16 minutes or about 18 minutes. During this process, the rotation speed is maintained at 500 to 800 rpm. Specifically, it can be 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 filtration after step S6. The defoaming method includes at least one of static defoaming and vacuum defoaming. The filtration uses a filter with a mesh size of 100-200 mesh, specifically approximately 150 mesh.

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

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

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

[0092] According to some embodiments of the present invention, the substrate includes at least one of bare steel, rusted steel, and old paint film. The old paint film is made of materials such as epoxy and polyurethane. The paint films formed on the surface of the above-mentioned substrates all 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. Specifically, it can be approximately 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 this invention actually means that the error is allowed to be within ±2%, for example, about 100 is actually 100 ± 2% × 100.

[0096] Other features and advantages of the invention will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. Detailed Implementation

[0097] The following will describe the concept and technical effects of the present invention clearly and completely with reference to embodiments, so as to fully understand the purpose, features and effects of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are all within the scope of protection of the present invention.

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

[0099] Example 1

[0100] This example demonstrates the preparation of a UV-LED curable repair paint. The specific raw materials are shown in Table 1, and the preparation steps are as follows:

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

[0102] S2. While stirring at 600 rpm, slowly add the prescribed amount of rust-preventive pigment and thixotropic filler; after the addition is complete, increase the speed to 1200 rpm and stir for 15 minutes to initially wet the powder; then switch to a sand mill and grind for 30 minutes until the fineness meets the requirements (≤30μm); during the grinding process, pay attention to controlling the temperature (≤50℃);

[0103] S3. Transfer the mixture obtained in step S2 to a paint mixing tank; under low-speed stirring at 600 rpm, slowly add the formulated amount of resin and the remaining reactive diluent, and continue stirring for 25 minutes to ensure uniform mixing.

[0104] S4. Under low-speed stirring at 600 rpm, add the leveling agent and light stabilizer (UV absorber) in the formula amount in sequence; stir for 8 minutes after each additive is added to ensure full dispersion;

[0105] S5. Under light-proof or weak yellow light, slowly add the prescribed amount of photoinitiator while stirring at a low speed of 600 rpm; after adding, continue stirring for 40 minutes to ensure that the photoinitiator is completely dissolved and evenly dispersed. Control the temperature below 35℃.

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

[0107] S7. Let the mixture obtained in step S6 stand to defoam; then filter it through a 200-mesh sieve to obtain UV-LED cured repair paint; finally, put the product into an opaque container and seal it for storage.

[0108] Example 2 and Comparative Examples 1-3 each prepared a UV-LED-curable repair paint, the specific difference from Example 1 being:

[0109] The raw materials used in some preparations are different, and the specific differences are shown in Table 1.

[0110] Table 1. Raw materials (parts by mass) for preparing UV-LED cured repair paints in the examples and comparative examples.

[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 shows the performance of the repair paints obtained in the examples and comparative examples.

[0115]

[0116]

[0117] In Table 2, the method for obtaining the paint film for the performance test is the same as that for obtaining the paint film in "Curing Condition". The substrate used is rusted steel. Before use, the substrate is simply polished to make its surface smooth.

[0118] Comparing the results of Example 1 and Example 2, it can be seen that, within the scope provided by the present invention, the overall performance of the paint film obtained by the repair paint is good. However, the overall effect is even better after using two photoinitiators; this indicates that there is a significant synergistic effect between the photoinitiator and other components such as resin.

[0119] Comparing the results of Example 1 and Comparative Examples 1-2, 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 obtained paint film will be severely degraded. This shows that in the repair paint provided by the present invention, the three resins have a significant synergistic effect, and the synergistic effect 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 is evident that if no rust-inhibiting filler is added to the raw materials for preparing the repair paint, not only will the adhesion of the paint film to the steel structure surface deteriorate, but its hardness, corrosion resistance, and aging performance will also be significantly reduced; that is, effects beyond those of the rust-inhibiting filler are produced. Therefore, it can be seen that in the repair paint system provided by this invention, a significant synergistic effect occurs between the rust-inhibiting filler and other types of raw materials.

[0121] In summary, this invention addresses the shortcomings of existing steel surface repair paints by providing a UV-LED curable coating specifically designed for steel structure repair. Through the synergistic effects of resins, resins and photoinitiators, and rust-inhibiting fillers and other raw materials, this repair paint exhibits extremely fast curing speed (under UV-LED light), excellent substrate adhesion (especially to rusted or old-painted steel structures), good workability (e.g., scraping, brushing), sufficient hiding power, and excellent corrosion resistance, weather resistance, and mechanical properties, while also meeting environmental requirements (solvent-free). Due to these advantages, the repair paint provided by this invention is expected to be widely used in steel surface repair.

[0122] The embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of the present invention. Furthermore, the embodiments of the present invention and the features thereof can be combined with each other unless otherwise specified.

Claims

1. A UV-LED cured repair paint, characterized in that, The raw materials for preparing the repair paint, by weight percentage, include: Resin content: 35-60%; Filler content: 5-30%; Photoinitiator 3~10%; The resin is composed of alicyclic acrylic resin, polyurethane acrylate resin and modified polyester acrylic resin; The mass ratio of the alicyclic acrylic resin, polyurethane acrylate resin, and modified polyester acrylic resin is 20~30:10~25:5~15; The alicyclic acrylic resin is DR3214 from Yantai Donghua New Materials Co., Ltd. The polyurethane acrylate resin is Sartoma's PRO33555; The modified polyester acrylic resin is QT-64 from Guangdong Qiante Polymer Materials Co., Ltd. The filler includes rust-preventive filler; The rust-inhibiting filler includes zinc phosphate and modified aluminum tripolyphosphate; The mass ratio of zinc phosphate to modified aluminum tripolyphosphate is 0.8~1.2:1; The photoinitiator is composed of acylphosphine oxide type initiators and α-amino ketone type initiators; The mass ratio of the acylphosphine oxide initiator to the α-aminoketone initiator is 2~6:0.5~3.

2. The repair paint according to claim 1, characterized in that, The raw materials for preparing the repair paint also include an active diluent.

3. The repair paint according to claim 2, characterized in that, The reactive diluent includes at least one of tripropylene glycol diacrylate, 1,6-hexanediol diacrylate, hydroxyethyl methacrylate, and isobornyl acrylate.

4. The repair paint according to claim 2, characterized in that, The reactive diluent accounts for 10-30% of the mass percentage of the raw materials used in the preparation of the repair paint.

5. The repair paint according to claim 1, characterized in that, The raw materials for preparing the repair paint also include additives.

6. The repair paint according to claim 5, characterized in that, The additives include at least one of dispersants, leveling agents, defoamers, adhesion promoters, and light stabilizers.

7. The repair paint according to claim 5, characterized in that, The additive accounts for 1-5% of the mass of the raw materials used in the preparation of the repair paint.

8. The repair paint according to claim 1, characterized in that, The filler also includes at least one of color fillers and thixotropic fillers.

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

10. A method for preparing a paint film, characterized in that, This includes applying the repair paint according to any one of claims 1 to 8 to the surface of a substrate and then curing it with UV-LED.

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