Low-temperature fast-curing powder coating as well as preparation method and application thereof

Abstract

The invention relates to the technical field of coatings, and discloses a low-temperature fast-curing powder coating as well as a preparation method and application thereof. The low-temperature fast-curing powder coating is prepared from the following raw materials in parts by mass: 160 to 300 parts of carboxyl-terminated polyester resin, 20 to 100 parts of epoxy acrylic matting resin, 1 to 20 parts of curing agent, 1 to 10 parts of accelerant and 50 to 150 parts of filler. The low-temperature fast curing powder coating provided by the invention can be cured under the condition of 200 DEG C / 60s to form a coating with the thickness of 60-100mu m, and the coating has low gloss less than 15GU, has excellent flexibility, impact resistance and chemical resistance, and can meet the application requirements of coiled material coating on the powder coating.

Description

Technical Field

[0001] This invention relates to the field of coating technology, and in particular to a low-temperature rapid-curing powder coating, its preparation method, and its application. Background Technology

[0002] Stricter environmental regulations have driven the transformation of industrial production towards green and low-carbon practices. The coatings industry, traditionally a high-energy-consuming and high-polluting sector, faces an urgent need to develop new low-pollution, high-efficiency, and sustainable coating materials. Coil and powder coatings, due to their environmentally friendly characteristics (such as solvent-free, low VOC emissions, and recyclability) and excellent coating performance (including good mechanical properties, chemical resistance, and decorative properties), have gained widespread attention in areas such as building curtain walls, metal roofing tiles, home appliances, and furniture. Matte coatings, in particular, have won consumer favor with their understated and elegant texture.

[0003] However, the curing temperature of conventional coil powder coatings is typically as high as 250-300℃, which not only leads to huge energy consumption but also limits their application on heat-sensitive substrates (such as certain plastics or pre-treated metals). High-temperature curing processes not only increase production costs but also exacerbate carbon emissions, contradicting the goals of environmental sustainability. Therefore, developing low-temperature, rapid-curing powder coatings has become an important research direction in the industry. Low-temperature, rapid-curing technology can significantly reduce energy consumption, shorten coating cycles, improve production efficiency, reduce carbon emissions, and expand the application range of coatings, showing broad market prospects.

[0004] Despite the significant advantages of low-temperature rapid-curing powder coatings, their development faces substantial technical challenges. The core issue lies in the prominent contradiction between the low-temperature rapid-curing process and achieving stable matting effects while ensuring the overall performance of the coating. On one hand, the lower the curing temperature, the shorter the time window for powder melting, leveling, and cross-linking reactions (typically only 30-60 seconds). This makes it difficult for the coating surface to form a uniform structure with sufficient micro-roughness to achieve effective light scattering, drastically increasing the difficulty of achieving matting. On the other hand, lower gloss (i.e., better matting effect, such as less than 15 GU) usually indicates a more complex microstructure or more micro-defects on the coating surface. This often leads to a simultaneous decline in the coating's flexibility, impact resistance, flexural strength, and corrosion resistance. This negative correlation between properties makes technological breakthroughs extremely challenging. For example, under low-temperature conditions, resin compatibility and reaction kinetics become particularly critical: insufficient reactivity may lead to incomplete curing, affecting coating performance; while an inadequate matting mechanism makes it difficult to achieve the required low gloss.

[0005] Therefore, how to achieve a uniform and stable low-gloss effect in a very short time during low-temperature curing, while ensuring that the coating maintains or even exceeds the core performance indicators such as excellent flexibility, impact resistance, and adhesion under conventional curing conditions, has become a major challenge and core technology in the current field of coil powder coatings.

[0006] Currently, there are no powder coating products on the market that can simultaneously achieve low-temperature rapid curing (curing within 30-60 seconds), low gloss (less than 15 GU), and meet the conventional performance requirements for coil applications. Existing coil powder coatings with good matting effects generally require baking at 230-280℃ for 1-8 minutes, which obviously cannot meet the energy-saving and high-efficiency requirements of low-temperature rapid curing. CN 112552495 A discloses a low-temperature rapid curing powder coating and its preparation method, which can achieve curing at 160℃ for 2 minutes, but its coating gloss is in the semi-gloss range (50-70 GU), failing to meet the ultra-low gloss requirements. Other existing technologies often achieve low gloss by adding external matting agents or complex processes, but this may introduce other problems, such as poor coating uniformity, decreased mechanical properties, or increased costs. Therefore, further precise optimization of the match between reactivity and matting efficiency has become the key to breaking through the technical bottleneck. Summary of the Invention

[0007] The present invention aims to at least solve one of the aforementioned technical problems existing in the prior art. Therefore, one objective of the present invention is to provide a low-temperature, rapid-curing powder coating.

[0008] The second objective of this invention is to provide a method for preparing such a low-temperature, rapid-curing powder coating.

[0009] The third objective of this invention is to provide a matte coating.

[0010] The fourth objective of this invention is to provide applications for low-temperature, rapid-curing powder coatings.

[0011] To achieve the above objectives, the technical solution adopted by the present invention is as follows: The first aspect of the present invention provides a low-temperature rapid curing powder coating, comprising, by weight, the following raw materials: 160-300 parts of carboxyl-terminated polyester resin, 20-100 parts of epoxy acrylic matte resin, 1-20 parts of curing agent, 1-10 parts of accelerator, and 50-150 parts of filler.

[0012] In some embodiments of the present invention, the low-temperature rapid curing powder coating comprises, by weight, the following raw materials: 180-250 parts of carboxyl-terminated polyester resin, 30-70 parts of epoxy acrylic matte resin, 3-10 parts of curing agent, 2-6 parts of accelerator, and 80-110 parts of filler.

[0013] In some embodiments of the present invention, the carboxyl-terminated polyester resin is selected from at least one of resin NH-3363 and resin NH-3343 from Qingtian Materials Technology Co., Ltd.

[0014] In some embodiments of the present invention, the epoxy equivalent of the epoxy acrylate matte resin is 200-400 g / eq; the softening point is 100-160℃.

[0015] In some preferred embodiments of the present invention, the epoxy acrylate matte resin has an epoxy equivalent of 250-350 g / eq and a softening point of 120-140°C.

[0016] In some embodiments of the present invention, the epoxy acrylate matte resin comprises, by weight, the following raw materials: 30-70 parts glycidyl methacrylate, 10-40 parts butyl acrylate, 10-40 parts caprolactone acrylate, 10-30 parts ethyl acrylate, 5-25 parts styrene, 1-15 parts methyl methacrylate, and 10-40 parts initiator.

[0017] In some preferred embodiments of the present invention, the epoxy acrylate matte resin comprises, by weight, the following raw materials: 40-60 parts glycidyl methacrylate, 15-30 parts butyl acrylate, 15-30 parts caprolactone acrylate, 15-20 parts ethyl acrylate, 5-20 parts styrene, 1-10 parts methyl methacrylate, and 15-30 parts initiator.

[0018] In some embodiments of the present invention, the initiator is selected from at least one of tert-butyl peroxide, tert-butyl peroxide-2-ethylhexanoate, azobisisobutyronitrile, and benzoyl peroxide.

[0019] In some preferred embodiments of the present invention, the initiator is selected from at least one of tert-butyl peroxide and tert-butyl peroxide-2-ethylhexanoate.

[0020] In some embodiments of the present invention, the epoxy acrylate matte resin is prepared by a method comprising the following steps: All raw materials except the initiator are mixed to obtain a mixture; First, the mixture is added dropwise to a polymerization solvent at a temperature of 100-130℃, then an initiator is added dropwise, and the reaction is maintained at this temperature. The polymerization solvent is removed to obtain the epoxy acrylate matte resin.

[0021] In some embodiments of the present invention, the reaction is carried out in a reaction vessel.

[0022] In some embodiments of the present invention, the temperature of the polymerization solvent is 120-130°C.

[0023] In some embodiments of the present invention, the polymerization solvent is selected from xylene, toluene, dioxane, tetrahydrofuran, methyl ethyl ketone, ethyl acetate, cyclohexanone, and tetrachloromethane.

[0024] In some embodiments of the present invention, the dripping duration of the mixture is 1-2 hours.

[0025] In some embodiments of the present invention, the initiator is added for a duration of 1-3 hours.

[0026] In some embodiments of the present invention, the heat preservation reaction time is 4-5 hours.

[0027] In some embodiments of the present invention, the preparation of the epoxy acrylate matte resin, after solvent removal, further includes cooling and crushing operations.

[0028] In some embodiments of the present invention, the curing agent is selected from at least one of triglycidyl isocyanurate and hydroxyalkylamide.

[0029] In some preferred embodiments of the present invention, the curing agent is triglycidyl isocyanurate.

[0030] In some embodiments of the present invention, the promoter is selected from at least one of 2-methylimidazole and 2-phenylimidazole.

[0031] In some preferred embodiments of the present invention, the promoter is 2-methylimidazole.

[0032] In some embodiments of the present invention, the filler is selected from at least one of precipitated barium sulfate, calcium carbonate, and matting barium sulfate.

[0033] In some preferred embodiments of the present invention, the filler is barium sulfate that has been used to remove light.

[0034] In some embodiments of the present invention, the low-temperature rapid curing powder coating further includes the following raw materials by weight: 1-5 parts pigment, 2-8 parts leveling agent, 2-8 parts toughening agent, and 1-5 parts degassing agent.

[0035] In some preferred embodiments of the present invention, the low-temperature rapid curing powder coating further includes the following raw materials by weight: 1-3 parts pigment, 2-5 parts leveling agent, 2-5 parts toughening agent, and 1-3 parts degassing agent.

[0036] In some embodiments of the present invention, the pigment is selected from outdoor weather-resistant general-purpose pigments.

[0037] In some preferred embodiments of the present invention, the pigment is selected from at least one of rutile titanium dioxide, iron oxide red, and iron oxide yellow.

[0038] In some embodiments of the present invention, the leveling agent is selected from acrylate polymers.

[0039] In some preferred embodiments of the present invention, the leveling agent is GLP588.

[0040] In some embodiments of the present invention, the toughening agent is selected from at least one of nitrile rubber, polyamide, chlorinated polyethylene, and polybutadiene.

[0041] In some preferred embodiments of the present invention, the toughening agent is polyamide.

[0042] In some embodiments of the present invention, the degassing agent is selected from at least one of benzoin, polypropylene wax, and stearic acid.

[0043] In some preferred embodiments of the present invention, the degassing agent is benzoin.

[0044] In some embodiments of the present invention, the D50 particle size of the low-temperature rapid curing powder coating is 20-45 μm.

[0045] In some preferred embodiments of the present invention, the D50 particle size of the low-temperature rapid curing powder coating is 35-45 μm.

[0046] The second aspect of the present invention provides a method for preparing the low-temperature rapid-curing powder coating described in the first aspect of the present invention, comprising the following steps: The raw materials are mixed, extruded, and crushed to obtain the low-temperature rapid-curing powder coating.

[0047] In some embodiments of the present invention, the extrusion includes using a twin-screw extruder; the temperature of zone I of the extruder is 90-110°C, and the temperature of zone II is 90-110°C.

[0048] In some preferred embodiments of the present invention, the temperature of zone I of the extruder is 90-100°C, and the temperature of zone II is 90-100°C.

[0049] A third aspect of the present invention provides a matte coating formed from a low-temperature rapid-curing powder coating as described in the first aspect of the present invention.

[0050] In some embodiments of the present invention, the thickness of the matte coating is 60-100 μm and the gloss is less than 15 GU; during the formation of the matte coating, the curing temperature of the low-temperature rapid curing powder coating is 180-220℃ and the curing time is 40-60s.

[0051] In some preferred embodiments of the present invention, the gloss of the matte coating is 5-10 GU.

[0052] In some preferred embodiments of the present invention, during the formation of the matte coating, the curing temperature of the low-temperature rapid curing powder coating is 180-200°C, and the curing time is 50-60 seconds.

[0053] The fourth aspect of the present invention provides the application of the low-temperature rapid-curing powder coating described in the first aspect of the present invention in coil coating.

[0054] The basic principles of this invention are explained as follows: The low-temperature rapid-curing powder coating provided by this invention achieves low-temperature rapid curing and stable ultra-low gloss through the synergistic effect of various raw materials, as detailed below: 1) This invention utilizes carboxyl-terminated polyester resin to provide the main reactive functional group, carboxyl groups, and epoxy acrylate matte resin to provide highly reactive functional groups, epoxy groups, and a curing agent to provide additional epoxy groups, thereby increasing the crosslinking density and accelerating the chemical reaction through an accelerator. Ordinary low-temperature curing systems may only rely on the reaction between polyester resin and curing agent. This invention introduces epoxy acrylate matte resin with a low epoxy equivalent (200-400 g / eq) (by increasing the proportion of glycidyl methacrylate to reduce the epoxy equivalent and increase the number of epoxy groups), thereby increasing the concentration and activity of reactive groups. Under the action of the accelerator, the activation energy of the ring-opening reaction between carboxyl groups and epoxy groups is reduced, so that the entire coating system can undergo a vigorous and sufficient crosslinking reaction within a very short low-temperature time window, forming a dense three-dimensional network structure, which meets the process requirements of low-temperature rapid curing. 2) This invention uses carboxyl-terminated polyester resin as the main continuous phase and epoxy acrylate matte resin as the incompatible dispersed phase, and adds fillers to assist in increasing surface roughness. Although both epoxy acrylate resin and polyester resin participate in the curing reaction, due to significant differences in their chemical main chain structure, polarity, and solubility parameters, they are thermodynamically incompatible during melt blending. In the extremely short time of coating melting, leveling, and curing, the two resins undergo phase separation. The polyester resin forms a continuous and relatively flat substrate, while the epoxy acrylate resin precipitates and forms tiny, discontinuous islands that are dispersed throughout the coating. These tiny, unevenly distributed epoxy acrylate resin regions disrupt the macroscopic continuity of the coating surface. The cured coating surface is no longer an ideal smooth mirror, but rather forms microscopic unevenness. When light shines on this surface, diffuse reflection occurs, resulting in a low-gloss or even matte effect. The filler particles themselves can further increase the microscopic unevenness of the surface, producing a synergistic matte effect with the phase separation effect of the resin.

[0055] Compared with the prior art, the beneficial effects of the present invention are: The low-temperature rapid-curing powder coating provided by this invention constructs a highly efficient reaction system by compounding carboxyl-terminated polyester resin and low epoxy equivalent epoxy acrylic matte resin, along with a curing agent and an accelerator. This system can achieve complete curing under extreme conditions of 200℃ and 60s, with significantly lower energy consumption than traditional processes. The resulting coating has a low gloss of less than 15 GU, and this matte characteristic does not depend on physical additives but rather originates from the phase separation of the incompatibility of the two resins during curing, naturally forming a uniform micro-rough surface with stable gloss and a smooth appearance. At the same time, the coating also possesses excellent flexibility, impact resistance, and superior chemical resistance, meeting market demands for coil powder coatings and expanding the application range of coatings. Detailed Implementation

[0056] The present invention will be further described in detail below through specific embodiments. Unless otherwise specified, the raw materials, reagents, or apparatus used in the embodiments and comparative examples are all available from conventional commercial sources or can be obtained by existing technical methods. Unless otherwise specified, the test or experimental methods are conventional methods in the art.

[0057] Note: Unless otherwise specified, "parts" in the following examples and comparative examples refer to "parts by weight"; the carboxyl-terminated polyester resins NH-3363 and NH-3343 used are products of Qingtian Materials Technology Co., Ltd.

[0058] Example 1 This embodiment prepares a low-temperature rapid-curing powder coating. The raw materials and their amounts are shown in Table 1. Table 1. Raw materials and dosages for the preparation of low-temperature rapid-curing powder coating in Example 1

[0059] The preparation steps of epoxy acrylate matte resin A are as follows: In a reactor, xylene was heated to 130°C. 50 parts glycidyl methacrylate, 20 parts butyl acrylate, 20 parts caprolactone acrylate, 15 parts ethyl acrylate, 10 parts styrene, and 5 parts methyl methacrylate were mixed and added dropwise to xylene for 1.5 hours. Then, 20 parts tert-butyl benzoate were added dropwise for 2 hours, and the reaction was maintained at this temperature for 4.5 hours. After being discharged in a molten state and cooled, the product was crushed to obtain epoxy acrylate matte resin A (epoxy equivalent of 260 g / eq, softening point of 127°C).

[0060] The preparation steps for low-temperature rapid curing powder coatings are as follows: Weigh each raw material according to the formula in Table 1, mix them thoroughly in a mixing cylinder and crush them to obtain a mixture. The mixture is then melt-mixed, uniformly dispersed and extruded in a twin-screw extruder. The temperature of zone I and zone II of the extruder is 95℃. After pressing, cooling and crushing, the mixture is then pulverized and sieved by a special pulverizer to obtain a low-temperature fast-curing powder coating with a D50 particle size of 35-45μm.

[0061] Example 2 This embodiment prepares a low-temperature rapid-curing powder coating. The raw materials and their amounts are shown in Table 2. Table 2. Raw materials and dosages for the preparation of low-temperature rapid-curing powder coating in Example 2

[0062] In this example, epoxy acrylate matte resin A is the same as in Example 1; The preparation steps for low-temperature rapid curing powder coatings are as follows: Weigh each raw material according to the formula in Table 2, mix them thoroughly in a mixing cylinder and crush them to obtain a mixture. The mixture is then melt-mixed, uniformly dispersed and extruded in a twin-screw extruder. The temperature of Zone I and Zone II of the extruder is 95℃. After pressing, cooling and crushing, the mixture is then pulverized and sieved by a special pulverizer to obtain a low-temperature fast-curing powder coating with a D50 particle size of 35-45μm.

[0063] Example 3 This embodiment prepares a low-temperature rapid-curing powder coating. The raw materials and their amounts are shown in Table 3. Table 3. Raw materials and dosages for the preparation of low-temperature rapid-curing powder coating in Example 3

[0064] In this example, epoxy acrylate matte resin A is the same as in Example 1; The preparation steps for low-temperature rapid curing powder coatings are as follows: Weigh each raw material according to the formula in Table 3, mix them thoroughly in a mixing cylinder and crush them to obtain a mixture. The mixture is then melt-mixed, uniformly dispersed and extruded in a twin-screw extruder. The temperature of zone I and zone II of the extruder is 95℃. After pressing, cooling and crushing, the mixture is then pulverized and sieved by a special pulverizer to obtain a low-temperature fast-curing powder coating with a D50 particle size of 35-45μm.

[0065] Comparative Example 1 This comparative example prepares a low-temperature rapid-curing powder coating. The raw materials and their amounts are shown in Table 4. Table 4. Raw materials and dosages used in the preparation of low-temperature rapid-curing powder coating in Comparative Example 1

[0066] The preparation steps of epoxy acrylate matte resin B are as follows: In a reactor, xylene was heated to 130°C. 20 parts glycidyl methacrylate, 20 parts butyl acrylate, 20 parts caprolactone acrylate, 15 parts ethyl acrylate, 10 parts styrene, and 5 parts methyl methacrylate were mixed and added dropwise to xylene for 1.5 hours. Then, 20 parts tert-butyl benzoate were added dropwise for 2 hours, and the reaction was maintained at this temperature for 4.5 hours. After being discharged in a molten state, the mixture was cooled and crushed to obtain epoxy acrylate matte resin B (epoxy equivalent of 450 g / eq, softening point of 131°C).

[0067] The preparation steps for low-temperature rapid curing powder coatings are as follows: Weigh each raw material according to the formula in Table 4, mix them thoroughly in a mixing cylinder and crush them to obtain a mixture. The mixture is then melt-mixed, uniformly dispersed and extruded in a twin-screw extruder. The temperature of zone I and zone II of the extruder is 95℃. After being pressed into tablets, cooled and crushed by a tablet press, the mixture is then pulverized by a special pulverizer and sieved to obtain a low-temperature fast-curing powder coating with a D50 particle size of 35-45μm.

[0068] Comparative Example 2 This comparative example prepares a low-temperature rapid-curing powder coating. The raw materials and their amounts are shown in Table 5. Table 5. Raw materials and dosages used in the preparation of low-temperature rapid-curing powder coating in Comparative Example 2

[0069] The preparation steps of epoxy acrylate matte resin C are as follows: In a reactor, xylene was heated to 130°C. 50 parts glycidyl methacrylate, 10 parts butyl acrylate, 5 parts caprolactone acrylate, 8 parts ethyl acrylate, 10 parts styrene, and 5 parts methyl methacrylate were mixed and added dropwise to xylene for 1.5 hours. Then, 20 parts tert-butyl benzoate were added dropwise for 2 hours, and the reaction was maintained at this temperature for 4.5 hours. After being discharged in a molten state, the mixture was cooled and crushed to obtain epoxy acrylate matte resin C (epoxy equivalent of 260 g / eq, softening point of 129°C).

[0070] The preparation steps for low-temperature rapid curing powder coatings are as follows: Weigh each raw material according to the formula in Table 5, mix them thoroughly in a mixing cylinder and crush them to obtain a mixture. The mixture is then melt-mixed, uniformly dispersed and extruded in a twin-screw extruder. The temperature of zone I and zone II of the extruder is 95℃. After being pressed into tablets, cooled and crushed by a tablet press, the mixture is then pulverized by a special pulverizer and sieved to obtain a low-temperature fast-curing powder coating with a D50 particle size of 35-45μm.

[0071] Performance testing The low-temperature rapid-curing powder coatings prepared in Examples 1-3 and Comparative Examples 1 and 2 were electrostatically sprayed onto aluminum plates and cured at 200°C for 60 seconds to form a coating with a thickness of 60-100 μm. The gloss, impact resistance, flexibility, pencil hardness and MEK resistance (resistance of the coating to methyl ethyl ketone (MEK) solvent) were tested. All tests were conducted in accordance with GB / T 23443-2009 "Aluminum Single Panels for Building Decoration".

[0072] Table 6 Coating performance test results

[0073] Table 6 shows the coating performance test results. As can be seen from Table 6, the powder coatings prepared in Examples 1-3 and Comparative Examples 1 and 2 can all be cured rapidly at low temperature under the condition of 200℃ / 60s and have a low gloss of less than 15GU. This indicates that the incompatibility phase separation mechanism of the matting resin used in this invention is effective. As long as a sufficient amount of matting resin is added, it can separate from the main polyester resin to form a micro-rough surface and achieve matting.

[0074] Based on this, after the low-temperature rapid curing powder coatings prepared in Examples 1-3 form a coating, the coating has a smooth appearance, and all impact resistance and flexibility tests are qualified. While matting, it maintains good mechanical properties, and the MEK resistance is higher than 80 times, indicating that the system is completely cured and the network is dense.

[0075] In Comparative Examples 1 and 2, the coatings failed to withstand impact and exhibited flexibility cracking. This was because the proportion of glycidyl methacrylate in the epoxy acrylate matte resin B used in Comparative Example 1 was reduced, directly leading to a decrease in the number of epoxy groups and an increase in epoxy equivalent. Under low-temperature, rapid curing conditions, the insufficient number of epoxy groups resulted in incomplete crosslinking between the epoxy acrylate matte resin B and the carboxyl-terminated polyester resin, leading to defects in the cured network, making it insufficiently dense and strong. In Comparative Example 2, the proportion of flexible monomers in the epoxy acrylate matte resin C was reduced, increasing the rigidity of the epoxy acrylate matte resin C segments and decreasing its flexibility. Although it had sufficient epoxy groups and the curing reaction was complete, the cured matte resin phase itself was very brittle and hard, making it prone to cracking when the coating was bent under stress. Furthermore, the MEK resistance of the coatings in Comparative Examples 1 and 2 decreased, especially in Comparative Example 1, where the insufficient number of epoxy groups in the epoxy acrylate matte resin B resulted in the lowest crosslinking density and the worst MEK resistance.

Claims

1. A low-temperature, rapid-curing powder coating, characterized in that, The preparation materials, by weight, include the following: 160-300 parts of carboxyl-terminated polyester resin, 20-100 parts of epoxy acrylic matte resin, 1-20 parts of curing agent, 1-10 parts of accelerator, and 50-150 parts of filler.

2. The low-temperature rapid-curing powder coating according to claim 1, characterized in that, The epoxy acrylate matte resin has an epoxy equivalent of 200-400 g / eq and a softening point of 100-160℃.

3. The low-temperature rapid-curing powder coating according to claim 2, characterized in that, The epoxy acrylate matte resin comprises, by weight, the following raw materials: 30-70 parts glycidyl methacrylate, 10-40 parts butyl acrylate, 10-40 parts caprolactone acrylate, 10-30 parts ethyl acrylate, 5-25 parts styrene, 1-15 parts methyl methacrylate, and 10-40 parts initiator.

4. The low-temperature rapid-curing powder coating according to claim 3, characterized in that, The epoxy acrylic matte resin is prepared by a method comprising the following steps: All raw materials except the initiator are mixed to obtain a mixture; First, the mixture is added dropwise to a polymerization solvent at a temperature of 105-155℃, then an initiator is added dropwise, and the reaction is maintained at this temperature. The polymerization solvent is removed to obtain the epoxy acrylate matte resin.

5. The low-temperature rapid-curing powder coating according to claim 4, characterized in that, The epoxy acrylic matte resin is prepared such that the dripping time of the mixture is 1-2 hours. And / or, the initiator is added for 1-3 hours; And / or, the heat preservation reaction time is 4-5 hours.

6. The low-temperature rapid-curing powder coating according to claim 1, characterized in that, The curing agent is selected from at least one of triglycidyl isocyanurate and hydroxyalkylamide; And / or, the promoter is selected from at least one of 2-methylimidazole and 2-phenylimidazole.

7. The method for preparing the low-temperature rapid-curing powder coating according to any one of claims 1-6, characterized in that, Includes the following steps: The raw materials are mixed, extruded, and crushed to obtain the low-temperature rapid-curing powder coating.

8. A matte coating, characterized in that, It is formed from the low-temperature rapid curing powder coating as described in any one of claims 1-6.

9. The coating according to claim 8, characterized in that, The thickness of the matte coating is 60-100μm, and the gloss is less than 15GU; during the formation of the matte coating, the curing temperature of the low-temperature rapid curing powder coating is 180-220℃, and the curing time is 40-60s.

10. The application of the low-temperature rapid-curing powder coating according to any one of claims 1-6 in coil coating.

Images