Low-temperature curing high-efficiency electrophoretic paint and preparation method thereof

Abstract

The invention relates to the technical field of electrophoretic paint, and particularly discloses low-temperature curing high-efficiency electrophoretic paint and a preparation method thereof. The low-temperature curing high-performance electrophoretic paint comprises the following components in parts by weight: 45-55 parts of epoxy resin; 35 to 45 parts of acrylic resin; 5-10 parts of a curing agent; 1-2 parts of a leveling agent; 1-2 parts of an anti-settling agent; 5-10 parts of a pigment filler; the curing agent is a modified imidazole compound; the preparation method comprises the following steps: stirring and mixing the epoxy resin and the acrylic resin, adding the flatting agent, the anti-settling agent and the pigment filler in the stirring process, stirring and mixing, and grinding to obtain a resin mixture; and stirring and mixing the resin mixture and the curing agent. In the application process of the low-temperature curing high-efficiency electrophoretic paint, the curing temperature can be greatly reduced, energy consumption is reduced, environmental pollution is reduced, and it is ensured that the electrophoretic paint has good film-forming property, adhesive force and corrosion resistance.

Description

Technical Field

[0001] The present application relates to the technical field of electrophoretic paints, and more specifically, to a low-temperature curing high-performance electrophoretic paint and a preparation method thereof. Background Art

[0002] Electrophoretic paint, also known as electrophoretic coating, is a coating material that uses an external electric field to direct the migration of pigments, resins and other particles suspended in the electrophoretic liquid and deposit them on the surface of the substrate of one of the electrodes. Due to its environmentally friendly characteristics, it is widely used in industry, especially in the automotive, building materials, hardware, home appliances and other industries.

[0003] Among them, epoxy acrylic electrophoretic paint is a type of solvent-free or low-solvent paint. It combines the characteristics of epoxy resin and acrylic resin, and has good chemical stability, light stability, weather resistance, adhesion and wear resistance. It has excellent performance and application range as a whole. The main components of epoxy acrylic electrophoretic paint include resin, pigment, filler and additives. Resin is the base material of electrophoretic paint. Acrylic resin provides good adhesion and flexibility, while epoxy resin increases the corrosion resistance of the paint film; pigments are used to give the coating color and opacity; fillers are used to adjust the coating volume, increase the thickness and hardness of the paint film; additives play a role in improving the performance of electrophoretic paint, such as leveling agents, defoamers and wetting agents. Epoxy acrylic electrophoretic paint is widely used in the surface protection and beautification of various materials, such as automobiles, furniture, electrical appliances and construction. Its advantages include tight coating, high gloss, strong corrosion resistance and environmental protection.

[0004] Regarding the above-mentioned related technologies, the inventors believe that electrophoretic paint generally needs to be fully cured at above 160°C during the application process, which not only consumes a lot of energy, but may also lead to increased energy consumption and carbon emissions. In addition, high-temperature curing can easily cause deformation of the workpiece, especially in the coating process of thin plate parts. The problem of thermal deformation is particularly prominent, which limits the widespread application of electrophoretic paint in environmentally friendly production systems. Although existing studies have attempted to reduce the curing temperature by adding specific catalysts, it often makes it difficult for the electrophoretic paint to maintain good film-forming properties, adhesion and corrosion resistance.

[0005] Therefore, it is urgent to propose a solution to solve the above technical problems. Summary of the invention

[0006] In order to significantly reduce the curing temperature, reduce energy consumption and reduce environmental pollution while ensuring good film-forming properties, adhesion and corrosion resistance of the electrophoretic paint, the present application provides a low-temperature curing high-performance electrophoretic paint and a preparation method thereof.

[0007] In the first aspect, the present application provides a low temperature curing high performance electrophoretic paint, which adopts the following technical solution: A low-temperature curing high-performance electrophoretic paint comprises the following components in parts by weight: Epoxy resin 45-55 parts; 35-45 parts of acrylic resin; 5-10 parts of curing agent; 1-2 parts of leveling agent; 1-2 parts of anti-settling agent; Pigment filler 5-10 parts; The curing agent is a modified imidazole compound.

[0008] By adopting the above technical scheme, epoxy resin plays a role in enhancing adhesion and corrosion resistance in electrophoretic paint, as well as improving the mechanical properties of the coating. The epoxy groups in the epoxy resin molecules can react with the double bonds in the acrylic molecules to form copolymers. This copolymer has excellent heat resistance and chemical resistance, and can significantly improve the adhesion, corrosion resistance and mechanical properties of the coating. The polar groups in the molecular structure of acrylic resin can form chemical bonds with the surfaces of various substrates, thereby enhancing the adhesion between the coating and the substrate, and the added acrylic resin can be dispersed in the epoxy resin to make up for the defects of the epoxy resin caused by curing shrinkage, making the coating more compact and showing a relatively stable and excellent coating quality. The modified imidazole compound further optimizes its curing performance by introducing other groups or changing its chemical structure, so that it shows better compatibility with the resin molecules in the mixed system of low-temperature curing high-efficiency electrophoretic paint, and can reduce the curing temperature of low-temperature curing high-efficiency electrophoretic paint, and on this basis, ensure the excellent performance of the cross-linking effect, and then obtain a coating with better quality. In the low-temperature curing high-performance electrophoretic paint, the present application mixes epoxy resin and acrylic resin in a specific ratio range and uses modified imidazole compounds as a curing agent to significantly reduce the curing temperature, reduce energy consumption, reduce environmental pollution, and ensure good film-forming properties, adhesion and corrosion resistance of the electrophoretic paint.

[0009] Preferably, the molecular weight of the epoxy resin is 400-800 Daltons.

[0010] By adopting the above technical scheme, low molecular weight epoxy resin has high hardness, large brittleness and low impact strength; although high molecular weight epoxy resin has better performance in heat resistance, strength and chemical resistance, it will cause uneven paint film; and the epoxy resin with the above molecular weight has better coordination with other component raw materials after application. When the low-temperature curing high-performance electrophoretic paint is cured at a lower temperature, it can show better film-forming properties, and the adhesion and corrosion resistance of the paint film are also better.

[0011] Preferably, the functional group content of the acrylic resin is 20-30 mgKOH / g.

[0012] By adopting the above technical scheme, if the functional group content of acrylic resin is low, it will lead to low hardness of the paint film and poor weather resistance, which is easily affected by environmental factors and aged; if the functional group content of acrylic resin is high, although it can improve the weather resistance and hardness of the coating, the curing speed is relatively slow, and it is difficult to ensure the uniformity of the paint film at a relatively low curing temperature; and after application, the acrylic resin with the above functional group content has better compatibility with other component raw materials, and when the low-temperature curing high-performance electrophoretic paint is cured at a lower temperature, a paint film of better quality can be obtained.

[0013] Preferably, 0.2-1 parts by weight of ultraviolet curing aid is also added to the components of the low-temperature curing high-performance electrophoretic paint.

[0014] By adopting the above technical solution and introducing UV curing aids, the electrophoretic paint can be quickly cured under UV light, further broadening the scope of application and being particularly suitable for quick drying requirements under on-site construction and outdoor working conditions; at the same time, the low-temperature curing and high-efficiency electrophoretic paint obtained by applying UV curing aids can be cured in just 2 minutes under UV light source, greatly shortening the curing cycle and being suitable for fast assembly line operations of large equipment.

[0015] Preferably, the leveling agent is a composite of polyether-modified silicone and fluorosilicone blend, and the fluorosilicone blend is a mixture of fluorine-modified siloxane and silicone-based leveling agent.

[0016] By adopting the above technical scheme, polyether-modified silicone as a leveling agent can significantly improve the leveling speed of electrophoretic paint, and bring about a good wetting effect on the substrate, so that the electrophoretic paint can be spread quickly and evenly during the construction process; the fluorosilicone blend formed by mixing fluorine-modified siloxane and silicone-type leveling agent not only has strong surface activity and foaming inhibition performance, but also has excellent scratch resistance and chemical stability, which can significantly improve the quality of the paint film; and the composite use of polyether-modified silicone and fluorosilicone blend as a leveling agent can show strong applicability to the application and curing of low-temperature curing and high-performance electrophoretic paint, thereby exerting a better leveling effect.

[0017] Preferably, the anti-settling agent is bentonite, fumed silica, or a combination of both.

[0018] By adopting the above technical scheme, the effect of the anti-settling agent on the electrophoretic paint is mainly reflected in preventing precipitation and stratification, so that the electrophoretic paint particles are evenly dispersed, bringing about improved dispersibility and stability; and the above-mentioned types of anti-settling agents are suitable for the mixing system of low-temperature curing high-performance electrophoretic paint, and can exert excellent and stable corresponding effects.

[0019] Preferably, the pigment filler is one or a combination of nano titanium dioxide and nano zinc oxide.

[0020] By adopting the above technical scheme, the pigment filler is the colorant of the electrophoretic paint, which gives the paint film rich color and gloss; and the pigment filler mentioned above can not only play the role of coloring and enhancing the gloss of the paint film, but also improve the construction performance and stability of the coating, thereby making the low-temperature curing high-performance electrophoretic paint have better application quality as a whole.

[0021] Preferably, the components of the low-temperature curing high-efficiency electrophoretic paint further include 1-2 parts by weight of a functional additive, wherein the functional additive is composed of organic silicon active particles and dimyrsine trioxide, and the weight ratio of the organic silicon active particles to dimyrsine trioxide is (2-5):1; The organosilicon active particles are prepared by the following steps: After mixing ethyl orthosilicate and hydroxypropyl methacrylate in a molar ratio of 1:(3.5-4.5), react in the presence of an acid catalyst, and perform a condensation reaction at 75-80° C. for 2-3 hours. During the reaction, the by-product ethanol is continuously removed, and finally, silicone active particles are obtained.

[0022] By adopting the above technical solution, bismuth trioxide has a high melting point and good chemical stability, which can improve the corrosion resistance and stability of electrophoretic paint, and bismuth trioxide can also ensure the structural stability of the paint film at a relatively low curing temperature. The use of organic silicon active particles, due to the introduction of Si-O bonds in electrophoretic paint, can utilize the cross-linking and networking characteristics of Si-O bonds, which can not only increase the cross-linking density between polymer molecular chains, but also enhance the reaction activity of polymers during electrophoresis. Therefore, at a relatively low curing temperature, it can also ensure that the electrophoretic paint has good film-forming properties, adhesion and corrosion resistance. At the same time, when organic silicon active particles and bismuth trioxide are used as functional additives, the two can play an excellent compounding and synergistic role with each other. At a relatively low curing temperature, the film-forming properties, adhesion and corrosion resistance of the electrophoretic paint can be significantly improved, thereby significantly improving the overall application of low-temperature curing and high-performance electrophoretic paint.

[0023] Preferably, the weight ratio of the organic silicon active particles to dioxygen oxide is 3:1.

[0024] By adopting the above technical scheme, when the silicone active particles and dioxygen oxide in the above weight ratio are used in combination, the two have a better coordination effect in the mixing system of low-temperature curing high-efficiency electrophoretic paint, and the overall quality of the low-temperature curing high-efficiency electrophoretic paint is also better.

[0025] In a second aspect, the present application provides a method for preparing a low-temperature curing high-performance electrophoretic paint, which adopts the following technical solution: A method for preparing a low-temperature curing high-performance electrophoretic paint comprises the following steps: (1) preparing raw materials including epoxy resin, acrylic resin, curing agent, leveling agent, anti-settling agent and pigment filler according to a proportion; (2) stirring and mixing the epoxy resin and acrylic resin in step (1), then adding a leveling agent, an anti-settling agent and a pigment filler during the stirring process, and then grinding after stirring and mixing to obtain a resin mixture; (3) The resin mixture and the curing agent in step (2) are stirred and mixed to obtain a low-temperature curing high-performance electrophoretic paint.

[0026] By adopting the above technical scheme, the above preparation method is simple to operate, and the raw materials are added and mixed in an orderly manner, which is beneficial for the raw materials to fully cooperate with each other and play excellent corresponding roles, thereby obtaining a low-temperature curing high-performance electrophoretic paint with excellent and stable quality; at the same time, the entire preparation method is more in line with industrial production, so that the low-temperature curing high-performance electrophoretic paint also meets the needs of large-scale industrial production.

[0027] In summary, this application has the following beneficial effects: 1. In the low-temperature curing high-performance electrophoretic paint, the present application mixes epoxy resin and acrylic resin in a specific ratio range, and uses modified imidazole compounds as a curing agent to significantly reduce the curing temperature, reduce energy consumption, reduce environmental pollution, and ensure good film-forming properties, adhesion and corrosion resistance of the electrophoretic paint; 2. The present application uses specially prepared organic silicon active particles and dioxygen oxide to form functional additives. Through the excellent compounding and synergistic effect between the two, the film-forming property, adhesion and corrosion resistance of the electrophoretic paint can be significantly improved at a relatively low curing temperature, thereby significantly improving the overall application of low-temperature curing and high-performance electrophoretic paint. DETAILED DESCRIPTION

[0028] The present application is further described in detail below in combination with preparation examples, embodiments and comparative examples.

[0029] Unless otherwise specified, the raw materials used in the preparation examples, embodiments and comparative examples of the present application are commercially available: The UV curing agent is TEGO 432 UV light curing anti-cratering agent; The polyether-modified silicone was purchased from Qingdao Baisenmao New Materials Co., Ltd. as anti-crater polyether-modified silicone BSM1270TEGO270; Fluorine-modified siloxane was purchased from Merck Chemicals, Germany, and is a fluorine-modified polysiloxane leveling agent MOK-2027; The silicone leveling agent purchased from BYK is BYK-333 silicone leveling agent.

[0030] Preparation examples of raw materials and / or intermediates Preparation Example 1 An organosilicon active particle is prepared by the following steps: Ethyl orthosilicate and hydroxypropyl methacrylate were mixed in a molar ratio of 1:4, reacted in the presence of an acid catalyst, and condensed at 77.5° C. for 2.5 hours. During the reaction, the byproduct ethanol was continuously removed, and finally silicone active particles were obtained.

[0031] Note: The acid catalyst used in the above preparation is sulfuric acid.

[0032] Preparation Example 2 An organosilicon active particle, which is different from Preparation Example 1 in that it is prepared by the following steps: Ethyl orthosilicate and hydroxypropyl methacrylate were mixed in a molar ratio of 1:3.5, reacted in the presence of an acid catalyst, and condensed at 75° C. for 3 hours. During the reaction, the by-product ethanol was continuously removed, and finally silicone active particles were obtained.

[0033] Preparation Example 3 An organosilicon active particle, which is different from Preparation Example 1 in that it is prepared by the following steps: Ethyl orthosilicate and hydroxypropyl methacrylate were mixed in a molar ratio of 1:4.5, reacted in the presence of an acid catalyst, and condensed at 80° C. for 2 hours. During the reaction, the by-product ethanol was continuously removed, and finally silicone active particles were obtained. Example

[0034] Example 1 A low temperature curing high performance electrophoretic paint, the preparation components and their corresponding weights are shown in Table 1, and is prepared by the following steps: (1) preparing raw materials including epoxy resin, acrylic resin, curing agent, leveling agent, anti-settling agent and pigment filler according to a proportion; (2) The epoxy resin and acrylic resin in step (1) were stirred and mixed at 500 r / min for 10 min, and then a leveling agent, an anti-settling agent and a pigment filler were added during the stirring process. After stirring and mixing at 1200 r / min for 20 min, the mixture was ground to 40 μm to obtain a resin mixture; (3) The resin mixture and the curing agent in step (2) are stirred and mixed to obtain a low-temperature curing high-performance electrophoretic paint.

[0035] Note: In the above steps, the curing agent is a modified imidazole compound purchased from EH-3293S of Aidico; the leveling agent is a polyether-modified silicone and a fluorosilicone blend in a weight ratio of 3:5, wherein the fluorosilicone blend is a mixture of fluorine-modified siloxane and a silicone leveling agent in a weight ratio of 1:2; the anti-settling agent is bentonite; the pigment filler is nano zinc oxide; the molecular weight of the epoxy resin is 600 Daltons; the functional group content of the acrylic resin is 25 mgKOH / g.

[0036] Example 2-3 A low temperature curing high performance electrophoretic paint, which is different from Example 1 in that the preparation components and their corresponding weights are shown in Table 1.

[0037] Table 1 Preparation components and their weight parts in Examples 1-3 (kg / part) raw material Example 1 Example 2 Example 3 Epoxy resin 50 45 55 Acrylic resin 40 35 45 Curing agent 7.5 5 10 Leveling agent 1.5 1 2 Anti-settling agent 1.5 1 2 Pigment fillers 7.5 5 10 Example 4 A low-temperature curing high-performance electrophoretic paint, which is different from Example 1 in that the molecular weight of the epoxy resin is 400 Daltons.

[0038] Example 5 A low-temperature curing high-performance electrophoretic paint, which is different from Example 1 in that the molecular weight of the epoxy resin is 800 Daltons.

[0039] Example 6 A low-temperature curing high-performance electrophoretic paint, which is different from Example 1 in that the molecular weight of the epoxy resin is 350 Daltons.

[0040] Example 7 A low-temperature curing high-performance electrophoretic paint, which is different from Example 1 in that the molecular weight of the epoxy resin is 850 Daltons.

[0041] Example 8 A low-temperature curing high-performance electrophoretic paint, which is different from Example 1 in that the functional group content of the acrylic resin is 20 mgKOH / g.

[0042] Example 9 A low-temperature curing high-performance electrophoretic paint, which is different from Example 1 in that the functional group content of the acrylic resin is 30 mgKOH / g.

[0043] Example 10 A low-temperature curing high-performance electrophoretic paint, which is different from Example 1 in that the functional group content of the acrylic resin is 18 mgKOH / g.

[0044] Embodiment 11 A low-temperature curing high-performance electrophoretic paint, which is different from Example 1 in that the functional group content of the acrylic resin is 32 mgKOH / g.

[0045] Example 12 A low-temperature curing high-performance electrophoretic paint, which is different from Example 1 in that 0.6 parts by weight of an ultraviolet curing aid is also added to the component, and is added and used together with the curing agent.

[0046] Example 13 A low-temperature curing high-performance electrophoretic paint, which is different from Example 12 in that 0.2 parts by weight of an ultraviolet curing aid is also added to the component.

[0047] Embodiment 14 A low-temperature curing high-performance electrophoretic paint, which is different from Example 12 in that 1 part by weight of an ultraviolet curing auxiliary agent is also added to the component.

[0048] Embodiment 15 A low-temperature curing high-performance electrophoretic paint, which is different from Example 1 in that 1.5 parts by weight of a functional additive are also added to the components of the low-temperature curing high-performance electrophoretic paint, and the functional additive is composed of silicone active particles and dioxymethylene oxide in a weight ratio of 3:1, and the silicone active particles are obtained in Preparation Example 1, and the functional additive is added together with a leveling agent, an anti-settling agent and a pigment filler.

[0049] Example 16 A low-temperature curing high-performance electrophoretic paint, which is different from Example 15 in that the weight portion of the functional additive added is 1 part.

[0050] Embodiment 17 A low-temperature curing high-performance electrophoretic paint, which is different from Example 15 in that the weight portion of the functional additive added is 2 parts.

[0051] Embodiment 18 A low-temperature curing high-performance electrophoretic paint, which is different from Example 15 in that the functional additive is composed of silicone active particles and dioxygen oxide in a weight ratio of 3.5:1.

[0052] Embodiment 19 A low-temperature curing high-performance electrophoretic paint, which is different from Example 15 in that the functional additive is composed of silicone active particles and dioxygen oxide in a weight ratio of 2:1.

[0053] Embodiment 20 A low-temperature curing high-performance electrophoretic paint, which is different from Example 15 in that the functional additive is composed of silicone active particles and dioxygen oxide in a weight ratio of 5:1.

[0054] Embodiment 21 A low-temperature curing high-performance electrophoretic paint, which is different from Example 15 in that the silicone active particles are obtained from Preparation Example 2.

[0055] Embodiment 22 A low-temperature curing high-performance electrophoretic paint, which is different from Example 15 in that the silicone active particles are obtained from Preparation Example 3.

[0056] Embodiment 23 A low-temperature curing high-performance electrophoretic paint, which is different from Example 15 in that no silicone active particles are used in the preparation components.

[0057] Embodiment 24 A low-temperature curing high-performance electrophoretic paint, which is different from Example 15 in that no myristic acid trioxide is used in the preparation components.

[0058] Comparative Example Comparative Example 1 A low-temperature curing high-performance electrophoretic paint is different from Example 1 in that, in the preparation components, 43 parts of epoxy resin and 47 parts of acrylic resin are taken.

[0059] Comparative Example 2 A low-temperature curing high-performance electrophoretic paint is different from Example 1 in that, in the preparation components, 57 parts of epoxy resin and 33 parts of acrylic resin are taken.

[0060] Comparative Example 3 A low-temperature curing high-performance electrophoretic paint, which is different from Example 1 in that the curing agent is an imidazole compound curing agent, specifically 2-phenylimidazole.

[0061] Performance test samples: The low-temperature curing high-efficiency electrophoretic paint obtained in Examples 1-24 was used as test sample 1-24, and the low-temperature curing high-efficiency electrophoretic paint obtained in Comparative Examples 1-3 was used as control sample 1-3.

[0062] Test method: Electrophoresis is carried out in accordance with the requirements of GB1727-1992 "General preparation method of paint film". The treated tinplate is connected to the electrode and immersed in the paint. The electrophoresis parameters are: electrophoresis voltage 80V, electrophoresis time 30S, inter-electrode distance 10cm, electrophoresis temperature 25℃.

[0063] (1) Curing temperature test of paint film: put the tinplate after electrophoresis in an oven and test the minimum temperature required to form a stable paint film within a baking time of 0.5h.

[0064] (2) Corrosion resistance test: The prepared paint film is immersed in a 5% sodium chloride solution at 80°C for rapid corrosion. The time when corrosion spots appear on the surface of the coating film is observed and recorded, and the corrosion resistance is evaluated.

[0065] (3) Adhesion test: Use a scratching tool to make grids on the sample surface. Usually, a cross-grid method is used, that is, a set of perpendicular straight lines are drawn in the vertical and horizontal directions. The tape is attached to the grids and then torn off with force. The adhesion of the paint film is evaluated by measuring the percentage of paint area remaining on the tape. The smaller the percentage of paint area remaining on the tape, the better the adhesion of the paint film.

[0066] (3) Film-forming performance test: bubbles are one of the common defects of electrophoretic coatings, which will affect the flatness and aesthetics of the electrophoretic coating; sag refers to the vertical lines formed by the electrophoretic coating during the coating process; pinholes refer to the small holes formed in the electrophoretic coating; visual inspection is used for detection, and pinhole detection can be assisted by a magnifying glass.

[0067] After completing the above tests on test samples 1-24 and control samples 1-3 in sequence, the corresponding results are recorded in Table 2.

[0068] Table 2 Test results of test samples 1-24 and control samples 1-3 It can be seen from Examples 1-3 and Comparative Examples 1-3 and Table 2 that in the preparation of low-temperature curing and high-performance electrophoretic paint, by mixing epoxy resin and acrylic resin in a specific ratio range and supplementing with a curing agent of a modified imidazole compound, the curing temperature can be greatly reduced, energy consumption can be reduced, environmental pollution can be reduced, and good film-forming properties, adhesion and corrosion resistance of the electrophoretic paint can be ensured; and when the combination of epoxy resin and acrylic resin exceeds the dosage range specified in the present application, or when an ordinary imidazole compound curing agent is used instead of a modified imidazole compound curing agent, it is found that the minimum curing temperature of the electrophoretic paint cannot reach 125°C, but is the conventional 160°C, and the corrosion resistance, adhesion and film-forming performance tests are poor, which will lead to a significant loss in the overall quality of the electrophoretic paint.

[0069] From Example 1 and Examples 4-7 and Table 2, it can be seen that when the molecular weight of the epoxy resin is 400-800 Daltons, the obtained low-temperature curing high-performance electrophoretic paint can exhibit better film-forming properties, adhesion and corrosion resistance during application. When the molecular weight of the epoxy resin is lower or higher than the above range, it will cause the low-temperature curing high-performance electrophoretic paint to lose performance in corrosion resistance, adhesion and film-forming performance tests. It can be seen that the epoxy resin with the above molecular weight can ensure the excellent stability of the low-temperature curing high-performance electrophoretic paint after application.

[0070] From Example 1 and Examples 8-9 and Table 2, it can be seen that the functional group content of the acrylic resin is 20-30 mgKOH / g, which can enable the obtained low-temperature curing high-performance electrophoretic paint to exhibit better film-forming properties, adhesion and corrosion resistance during application. When the functional group content of the acrylic resin is lower or higher than the above range, it will cause the low-temperature curing high-performance electrophoretic paint to lose performance in corrosion resistance, adhesion and film-forming performance tests. It can be seen that the acrylic resin with the above functional group content has better compatibility with other component raw materials after application, and can obtain a low-temperature curing high-performance electrophoretic paint with excellent and stable application quality.

[0071] It can be seen from Example 1 and Examples 12-14 and Table 2 that the introduction of UV curing aids does not affect the overall performance of low-temperature curing high-performance electrophoretic paint. Instead, it can increase the UV light conditions for rapid curing, which can greatly shorten the curing cycle.

[0072] It can be seen from Example 1 and Example 15-22 and Table 2 that the present application can significantly improve the film-forming property, adhesion and corrosion resistance of the electrophoretic paint at a relatively low curing temperature by using specially prepared organic silicon active particles and dioxymethylene oxide as functional additives, wherein when the weight ratio of organic silicon active particles to dioxymethylene oxide is 3:1, the two have a better coordination effect in the mixed system of low-temperature curing high-efficiency electrophoretic paint, and the overall quality of the low-temperature curing high-efficiency electrophoretic paint is also better. It can be seen from Example 23-24 and Table 2 that if only organic silicon active particles or dioxymethylene oxide are used, it can bring about the improvement of film-forming property, adhesion and corrosion resistance under the condition of low-temperature curing, but the improvement effect is limited, and the sum of the improvement effects brought by the use of each of the two alone is far less than the excellent improvement effect brought by the compounding of the two. It can be seen that the coordination between organic silicon active particles and dioxymethylene oxide can bring about a significant improvement effect of 1+1>2, which is conducive to obtaining a low-temperature curing high-efficiency electrophoretic paint with better application quality.

[0073] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A low temperature curing high performance electrophoretic paint, characterized in that: Contains the following components in parts by weight: Epoxy resin 45-55 parts; 35-45 parts of acrylic resin; 5-10 parts of curing agent; 1-2 parts of leveling agent; 1-2 parts of anti-settling agent; Pigment filler 5-10 parts; The curing agent is a modified imidazole compound.

2. The low temperature curing high performance electrophoretic paint according to claim 1, characterized in that: The molecular weight of the epoxy resin is 400-800 Daltons.

3. The low temperature curing high performance electrophoretic paint according to claim 1, characterized in that: The functional group content of the acrylic resin is 20-30 mgKOH / g.

4. The low temperature curing high performance electrophoretic paint according to claim 1, characterized in that: The components of the low-temperature curing high-performance electrophoretic paint also contain 0.2-1 parts by weight of an ultraviolet curing auxiliary agent.

5. The low temperature curing high performance electrophoretic paint according to claim 1, characterized in that: The leveling agent is a composite of polyether-modified organic silicon and fluorine-silicon blend, and the fluorine-silicon blend is formed by mixing fluorine-modified siloxane and organic silicon-based leveling agent.

6. The low temperature curing high performance electrophoretic paint according to claim 5, characterized in that: The anti-settling agent is one of bentonite and fumed silica or a combination of the two.

7. The low temperature curing high performance electrophoretic paint according to claim 1, characterized in that: The pigment filler is one of nano titanium dioxide and nano zinc oxide or a combination of the two.

8. The low temperature curing high performance electrophoretic paint according to claim 1, characterized in that: The components of the low-temperature curing high-performance electrophoretic paint further include 1-2 parts by weight of a functional additive, wherein the functional additive is composed of organic silicon active particles and dimyrsine trioxide, and the weight ratio of the organic silicon active particles to dimyrsine trioxide is (2-5):1; The organosilicon active particles are prepared by the following steps: Take ethyl orthosilicate and hydroxypropyl methacrylate in a molar ratio of 1: (3.5-4.5) and mix them. Then react them in the presence of an acid catalyst and carry out a condensation reaction at 75-80°C for 2-3 hours. During the reaction, the by-product ethanol is continuously removed to obtain silicone active particles.

9. The low temperature curing high performance electrophoretic paint according to claim 8, characterized in that: The weight ratio of the organic silicon active particles to dioxygen is 3:

1.

10. The method for preparing the low temperature curing high performance electrophoretic paint according to claim 1, characterized in that: The following steps are involved: (1) Prepare raw materials including epoxy resin, acrylic resin, curing agent, leveling agent, anti-settling agent and pigment filler according to the proportion; (2) stirring and mixing the epoxy resin and acrylic resin in step (1), then adding a leveling agent, an anti-settling agent and a pigment filler during the stirring process, and then grinding after stirring and mixing to obtain a resin mixture; (3) The resin mixture and the curing agent in step (2) are stirred and mixed to obtain a low-temperature curing high-performance electrophoretic paint.

Images