Protective coating for wind power aluminum frame and preparation method of protective coating

Abstract

The invention discloses a protective coating for a wind power aluminum frame and a preparation method of the protective coating, and belongs to the technical field of coating preparation. The water-based fluorocarbon resin emulsion is used as a base material, the nano cerium dioxide and the anti-ultraviolet absorbent are supplemented to form a protection system, and the modified graphene is combined, so that the quality of the coating is ensured, the corrosion resistance is obviously improved, the environmental tolerance of the coating can be obviously improved, and the coating has longer service life in a high-salt-mist environment. Besides, methyl methacrylate is adopted in the preparation raw materials of the microcapsule repairing agent, so that a rigid framework can be improved, the mechanical strength of the microcapsule repairing agent is improved, ethyl methacrylate is supplemented, a flexible chain segment is improved, the wall material toughness of the microcapsule repairing agent is improved, acrylic acid provides carboxyl, and the effect with a catalytic response agent is facilitated; the self-repairing paint has excellent compatibility, can be uniformly distributed in the paint system on the whole, has a certain self-repairing effect, and is beneficial to prolonging the service life of the wind power aluminum frame.

Description

Technical Field

[0001] The present invention relates to the technical field of coating preparation, and in particular, to a protective coating for wind power aluminum frames and a preparation method thereof. Background Art

[0002] Wind power aluminum frames are exposed to harsh environments such as high salinity, high humidity, and strong ultraviolet rays for a long time, and have extremely high requirements for the weather resistance, corrosion resistance, and environmental friendliness of the coating. Traditional solvent-based coatings have problems such as high VOC emissions and serious environmental pollution, while the weather resistance and mechanical properties of existing water-based coatings are often insufficient. Therefore, it is of great significance to develop a protective coating with both environmental friendliness and high performance.

[0003] During the use of wind power aluminum frames, coatings with specific functions are generally applied to protect the wind power aluminum frames. For example, the patent with Chinese patent number CN202510081186.6 discloses a water-based anti-corrosion coating based on an aluminum alloy substrate and its preparation process. The preparation raw materials of this patent include the following components: 55 - 70 parts of water-based acrylic modified epoxy alkyd resin, 4 - 10 parts of dioctyl phosphoric acid acyloxy titanate, 15 - 24 parts of inorganic nanomaterials, 1 - 3 parts of polydimethylsiloxane, 2 - 6 parts of ethoxy-modified polysiloxane, 2 - 5 parts of passivator, and 70 - 120 parts of water. The water-based anti-corrosion coating prepared by this patent has the advantages of corrosion resistance, strong adhesion, and good mechanical properties. Another example is the patent with Chinese patent number CN202510014478.8, which discloses an anti-corrosion coating for environmentally friendly aluminum alloy parts. Compared with traditional vapor-phase corrosion inhibitors, the arginine-modified sulfonated carbon nanotubes added in this patent can anchor and adsorb arginine due to the high specific surface area of the nanomaterials, and can slowly release amine small molecules into the atmosphere, thereby improving the anti-corrosion performance and extending the corrosion resistance time. At the same time, the introduction of two-dimensional nanozirconium phosphate sheets in the coating system can further increase the anti-corrosion effect of the coating through the covering effect. The two-dimensional nanozirconium phosphate and one-dimensional carbon nanotubes cooperate to build an anti-corrosion covering network, further improving the anti-corrosion performance of the coating. Another example is the patent with Chinese patent number CN202411850748.0, which discloses an anti-corrosion and rust-proof coating for aluminum alloy and its preparation method. This patent uses modified epoxy resin and acrylic resin as the base, and is compounded with raw materials such as nano-silica sol, rust inhibitor, and organic bentonite, and optimizes the raw materials and process conditions. The prepared coating has excellent adhesion, heat resistance, flame retardancy, mechanical properties, and anti-corrosion and rust-proof properties. However, in the prior art, there are still problems such as poor environmental tolerance, easy occurrence of microcracks in high salt fog environments, and difficulty in timely repair by artificial means after coating damage, resulting in protection aging, and thus affecting the application performance of wind power aluminum frames. Summary of the Invention

[0004] Based on this, in the existing technology, the protective coating for wind power aluminum frames has poor environmental tolerance, is prone to microcracks in a high salt spray environment, and it is difficult for manual workers to repair in time after the coating is damaged, resulting in a protection time limit and further affecting the application performance of wind power aluminum frames. Therefore, the present invention provides a protective coating for wind power aluminum frames and its preparation method. The specific technical solutions are as follows:

[0005] A protective coating for wind power aluminum frames, and the protective coating comprises the following raw materials for preparation in parts by weight:

[0006] 50 to 70 parts of a waterborne fluorocarbon resin emulsion, 3 to 7 parts of modified graphene, 10 to 20 parts of a microcapsule repair agent, 3 to 7 parts of a catalytic responder, 1 to 5 parts of an ultraviolet absorber, 3 to 9 parts of a film-forming agent, 3 to 7 parts of nano-ceria, 1 to 3 parts of a dispersant, 2 to 5 parts of a curing agent, 0.1 to 0.5 parts of an antifoaming agent, 0 to 20 parts of a pigment and filler, and 5 to 10 parts of deionized water.

[0007] Furthermore, the preparation method of the microcapsule repair agent is as follows:

[0008] Under the protection of nitrogen, isophorone diisocyanate is added to polyetheramine, and under the conditions of 60°C to 65°C, it is treated at a stirring speed of 100 r / min to 200 r / min for 1 h to 3 h, then 4,4'-dithiobenzoic acid, a catalyst, and an emulsifier are added, the temperature is raised to 80°C to 90°C, and stirring treatment is continued for 1 h to 2 h. The temperature is lowered to 40°C to 50°C, triethanolamine and an appropriate amount of water are added, and stirring is carried out for 10 min to 20 min to obtain a polymer emulsion;

[0009] Methyl methacrylate, ethyl methacrylate, acrylic acid, and benzoyl peroxide are added to the polymer emulsion, and under the conditions of 55°C to 70°C, stirring treatment is carried out at a rotation speed of 150 r / min to 300 r / min for 1 to 2 h, and then it is left to stand and cure for 3 h to 5 h. After drying, a microcapsule repair agent is obtained.

[0010] Furthermore, the weight part ratio of the isophorone diisocyanate, polyetheramine, 4,4'-dithiobenzoic acid, catalyst, emulsifier, and triethanolamine is (10 to 15):(3 to 5):(5 to 9):(0.1 to 0.8):(3 to 7):(1 to 2).

[0011] Furthermore, the weight part ratio of the methyl methacrylate, ethyl methacrylate, acrylic acid, benzoyl peroxide, and polymer emulsion is (40 to 50):(20 to 30):(5 to 9):(3 to 7):(12 to 20).

[0012] Furthermore, the preparation method of the catalytic responder is as follows:

[0013] An atactic copolymer of acrylic acid and acrylamide is mixed with 2-ethyl-4-methylimidazole and N,N'-methylenebisacrylamide, stirred at a speed of 100 r / min to 200 r / min for 10 min to 20 min, then silane-modified nano zinc oxide is added, and stirring is continued at 60 °C to 70 °C for 1 h to 3 h to obtain a catalytic responsive agent.

[0014] Further, the weight ratio of the atactic copolymer of acrylic acid and acrylamide, 2-ethyl-4-methylimidazole, N,N'-methylenebisacrylamide, and silane-modified nano zinc oxide is (10-20):(10-15):(0.5-3):(1-5).

[0015] Further, the ultraviolet absorber is at least one of 2-(2H-benzotriazol-2-yl)-4-methylphenol and 2-hydroxy-4-methoxybenzophenone.

[0016] Further, the film-forming agent is at least one of ethylene glycol monobutyl ether, propylene glycol monobutyl ether, and dipropylene glycol monobutyl ether.

[0017] Further, the dispersant is at least one of polyvinyl alcohol and carboxymethyl cellulose.

[0018] In addition, the present invention also provides a preparation method of a protective coating for a wind power aluminum frame, and the preparation method includes the following steps:

[0019] An aqueous fluorocarbon resin emulsion, modified graphene, an ultraviolet absorber, nano cerium dioxide, a dispersant, a curing agent, an antifoaming agent, and deionized water are added to a stirring kettle, stirred at a speed of 500 r / min to 1000 r / min for 30 min to 60 min, then a catalytic responsive agent, a film-forming agent, and a pigment filler are added, stirring is continued for 10 min to 15 min, and then a microcapsule repair agent is added, and stirring is carried out at a speed of 100 r / min to 150 r / min for 10 min to 30 min to obtain a protective coating for a wind power aluminum frame.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. The present invention uses an aqueous fluorocarbon resin emulsion as a base material, supplemented with nano cerium dioxide and an ultraviolet absorption agent to form a protection system, and combined with modified graphene. While ensuring the coating quality, the corrosion resistance is significantly improved, the environmental tolerance of the coating can be significantly improved, and it has a longer service life in a high salt fog environment.

[0022] 2. In the preparation raw materials of the microcapsule repair agent prepared by the present invention, methyl methacrylate is used to improve the rigid skeleton, increase the mechanical strength of the microcapsule repair agent, and ethyl methacrylate is supplemented to increase the flexible chain segment and the toughness of the wall material of the microcapsule repair agent. Acrylic acid provides carboxyl groups, which helps to interact with the catalytic responder. Overall, it can be evenly distributed in the coating system of the present application.

[0023] 3. The microcapsule repair agent added in the present invention has excellent compatibility and contains dynamic disulfide bonds. When the coating is damaged or the environmental pH changes, it can interact with the catalytic responder in time, trigger the disulfide bond exchange, and achieve a certain self-repair effect, thereby reducing the maintenance cost and helping to improve the service life of the wind power aluminum frame. Description of the Drawings

[0024] Figure 1 Schematic diagram of the protective coating sample for the wind power aluminum frame prepared in Example 3 of the present invention;

[0025] Figure 2 Schematic diagram of the application of the protective coating in Example 3 of the present invention.

[0026] Description of the reference numerals:

[0027] 1. Aluminum substrate; 2. Primer layer; 3. Topcoat layer. Detailed Embodiments

[0028] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below in conjunction with its embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not limit the protection scope of the present invention.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which the present invention belongs. The terms used in the description of the present invention in this specification are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0030] A protective coating for a wind power aluminum frame in an embodiment of the present invention, the protective coating comprising the following parts by weight of preparation raw materials:

[0031] 50 parts to 70 parts of waterborne fluorocarbon resin emulsion, 3 parts to 7 parts of modified graphene, 10 parts to 20 parts of microcapsule repair agent, 3 parts to 7 parts of catalytic responder, 1 part to 5 parts of ultraviolet absorber, 3 parts to 9 parts of film-forming agent, 3 parts to 7 parts of nano-cerium dioxide, 1 part to 3 parts of dispersant, 2 parts to 5 parts of curing agent, 0.1 part to 0.5 part of defoamer, 0 part to 20 parts of pigment and filler, 5 parts to 10 parts of deionized water.

[0032] In one embodiment, the preparation method of the modified graphene is as follows: The graphene is treated by plasma, then mixed with (3-aminopropyl)triethoxysilane, and stirred at a rotation speed of 200 r / min to 500 r / min for 15 min to 30 min.

[0033] In one embodiment, the conditions of the plasma treatment are: the power is 50 W to 100 W, and the time is 1 min to 5 min.

[0034] In one embodiment, the weight part ratio of the graphene to (3-aminopropyl)triethoxysilane is (9 to 15):(5 to 12).

[0035] In one embodiment, the graphene is in sheet form, with a thickness of 1 nm to 3 nm and a specific surface area ≥ 500 m 2 / g.

[0036] In one embodiment, the preparation method of the microcapsule repair agent is as follows:

[0037] Under the protection of nitrogen, isophorone diisocyanate is added to polyetheramine, and at 60°C to 65°C, it is treated at a stirring speed of 100 r / min to 200 r / min for 1 h to 3 h. Then, 4,4'-dithiobis(benzoic acid), a catalyst, and an emulsifier are added, the temperature is raised to 80°C to 90°C, and stirring is continued for 1 h to 2 h. The temperature is lowered to 40°C to 50°C, triethanolamine and an appropriate amount of water are added, and stirring is carried out for 10 min to 20 min to obtain a polymer emulsion;

[0038] Methyl methacrylate, ethyl methacrylate, acrylic acid, and benzoyl peroxide are added to the polymer emulsion, and at 55°C to 70°C, it is stirred at a rotation speed of 150 r / min to 300 r / min for 1 to 2 h, and then left to stand and cure for 3 h to 5 h. After drying, a microcapsule repair agent is obtained.

[0039] In one embodiment, the weight part ratio of the isophorone diisocyanate, polyetheramine, 4,4'-dithiobis(benzoic acid), catalyst, emulsifier, and triethanolamine is (10 to 15):(3 to 5):(5 to 9):(0.1 to 0.8):(3 to 7):(1 to 2).

[0040] In one embodiment, the catalyst is dibutyltin dilaurate.

[0041] In one embodiment, the emulsifier is at least one of polysorbate TW-85 and sodium dodecylbenzenesulfonate.

[0042] In one embodiment, the weight ratio of methyl methacrylate, ethyl methacrylate, acrylic acid, benzoyl peroxide, and polymer emulsion is (40-50):(20-30):(5-9):(3-7):(12-20).

[0043] In one embodiment, the preparation method of the catalytic responsive agent is as follows:

[0044] Mix the random copolymer of acrylic acid and acrylamide with 2-ethyl-4-methylimidazole and N,N'-methylenebisacrylamide, stir at a speed of 100 r / min to 200 r / min for 10 min to 20 min, then add silane-modified nano zinc oxide, and continue to stir at 60°C to 70°C for 1 h to 3 h to obtain the catalytic responsive agent.

[0045] In one embodiment, the weight ratio of the random copolymer of acrylic acid and acrylamide, 2-ethyl-4-methylimidazole, N,N'-methylenebisacrylamide, and silane-modified nano zinc oxide is (10-20):(10-15):(0.5-3):(1-5).

[0046] In one embodiment, the ultraviolet absorber is at least one of 2-(2H-benzotriazol-2-yl)-4-methylphenol and 2-hydroxy-4-methoxybenzophenone.

[0047] In one embodiment, the film-forming agent is at least one of ethylene glycol monobutyl ether, propylene glycol monobutyl ether, and dipropylene glycol monobutyl ether.

[0048] In one embodiment, the dispersant is at least one of polyvinyl alcohol and carboxymethyl cellulose.

[0049] In one embodiment, the curing agent is an aliphatic polyisocyanate.

[0050] In one embodiment, the defoaming agent is a polyether-modified silicone.

[0051] In addition, the present invention also provides a preparation method of a protective coating for a wind power aluminum frame, and the preparation method includes the following steps:

[0052] Add an aqueous fluorocarbon resin emulsion, modified graphene, an ultraviolet absorber, nano-ceria, a dispersant, a curing agent, an antifoaming agent, and deionized water to a stirring kettle, stir at a speed of 500 r / min to 1000 r / min for 30 min to 60 min, then add a catalytic responsive agent, a film-forming agent, and a pigment filler, continue stirring for 10 min to 15 min, and then add a microcapsule repair agent, stir at a speed of 100 r / min to 150 r / min for 10 min to 30 min to obtain a protective coating for a wind power aluminum frame.

[0053] In one embodiment, the protective coating for the wind power aluminum frame is used as a primer and can also be used in combination with a functional topcoat.

[0054] In one embodiment, the preparation method of the topcoat is as follows: Add 20 parts of hydroxymethylacrylamide, 10 parts of aliphatic glycidyl ether epoxy resin, 5 parts of acrylic resin, 6 parts of styrene, 5 parts of isocyanate, 1 part of polydimethylsiloxane, and 5 parts of barium sulfate to a mixing kettle, stir at a speed of 500 r / min for 3 h to obtain the topcoat.

[0055] The embodiments of the present invention will be described in detail below in conjunction with specific examples.

[0056] Example 1:

[0057] A preparation method of a protective coating for a wind power aluminum frame, the preparation method comprising the following steps:

[0058] By weight, subject 10 parts of graphene to plasma treatment for 5 min under the condition of a power of 50 W, then mix it with 8 parts of (3-aminopropyl)triethoxysilane, and stir at a speed of 200 r / min for 20 min to obtain modified graphene;

[0059] By weight ratio, under the protection of nitrogen, add 12 parts of isophorone diisocyanate to 4 parts of polyetheramine, at 60 °C, stir at a speed of 100 r / min for 2 h, then add 5 parts of 4,4'-dithiobisbenzoic acid, 0.5 part of dibutyltin dilaurate, and 5 parts of sodium dodecylbenzenesulfonate, raise the temperature to 80 °C, continue stirring for 2 h, cool down to 40 °C, add 1 part of triethanolamine and an appropriate amount of water, stir for 10 min to obtain a polymer emulsion; then add 40 parts of methyl methacrylate, 25 parts of ethyl methacrylate, 5 parts of acrylic acid, and 4 parts of benzoyl peroxide to 18 parts of the polymer emulsion, at 60 °C, stir at a speed of 150 r / min for 1 h, then stand for curing for 3 h, and after drying, obtain a microcapsule repair agent;

[0060] By weight ratio, 15 parts of a random copolymer of acrylic acid and acrylamide, 12 parts of 2-ethyl-4-methylimidazole, and 1 part of N,N'-methylenebisacrylamide are mixed, stirred at a speed of 150 r / min for 10 min, then 3 parts of silane-modified nano-zinc oxide are added, and at 65 °C, stirring is continued for 2 h to obtain a catalytic responder;

[0061] By weight ratio, 55 parts of a waterborne fluorocarbon resin emulsion, 5 parts of modified graphene, 3 parts of 2-hydroxy-4-methoxybenzophenone, 4 parts of nano-cerium dioxide, 2 parts of polyvinyl alcohol, 3 parts of aliphatic polyisocyanate, 0.3 part of polyether-modified silicone, and 8 parts of deionized water are added to a stirring kettle, stirred at a speed of 500 r / min for 40 min, then 5 parts of the catalytic responder, 7 parts of ethylene glycol monobutyl ether, and 10 parts of pigments and fillers are added, stirring is continued for 10 min, then 15 parts of the microcapsule repair agent are added, and stirred at a speed of 100 r / min for 10 min to obtain a protective coating for a wind power aluminum frame.

[0062] Example 2:

[0063] A preparation method of a protective coating for a wind power aluminum frame, the preparation method comprising the following steps:

[0064] By weight, 10 parts of graphene are treated by plasma at a power of 60 W for 4 min, then mixed with 10 parts of (3-aminopropyl)triethoxysilane, and stirred at a speed of 200 r / min for 20 min to obtain modified graphene;

[0065] By weight ratio, under the protection of nitrogen, 15 parts of isophorone diisocyanate are added to 5 parts of polyetheramine, at 65 °C, stirred at a speed of 150 r / min for 2 h, then 7 parts of 4,4'-dithiobisbenzoic acid, 0.7 part of dibutyltin dilaurate, and 6 parts of sodium dodecylbenzenesulfonate are added, heated to 80 °C, stirring is continued for 2 h, cooled to 40 °C, 2 parts of triethanolamine and an appropriate amount of water are added, and stirred for 15 min to obtain a polymer emulsion; then 45 parts of methyl methacrylate, 20 parts of ethyl methacrylate, 6 parts of acrylic acid, and 5 parts of benzoyl peroxide are added to 20 parts of the polymer emulsion, at 60 °C, stirred at a speed of 150 r / min for 1 h, then left to age for 3 h, and after drying, a microcapsule repair agent is obtained;

[0066] By weight ratio, 16 parts of a random copolymer of acrylic acid and acrylamide, 14 parts of 2-ethyl-4-methylimidazole, and 1 part of N,N'-methylenebisacrylamide are mixed, stirred at a speed of 150 r / min for 10 min, then 3 parts of silane-modified nano-zinc oxide are added, and at 65 °C, stirring is continued for 2 h to obtain a catalytic responder;

[0067] By weight ratio, add 55 parts of aqueous fluorocarbon resin emulsion, 6 parts of modified graphene, 5 parts of 2-(2H-benzotriazol-2-yl)-4-methylphenol, 3 parts of nano-ceria, 3 parts of polyvinyl alcohol, 2 parts of aliphatic polyisocyanate, 0.4 part of polyether-modified silicone and 7 parts of deionized water into a stirring kettle, stir at a speed of 500 r / min for 40 min, then add 6 parts of catalytic response agent, 7 parts of ethylene glycol monobutyl ether and 12 parts of pigment and filler, continue to stir for 10 min, and then add 15 parts of microcapsule repair agent, stir at a speed of 100 r / min for 10 min to obtain the protective coating for wind power aluminum frames.

[0068] Example 3:

[0069] A preparation method of a protective coating for wind power aluminum frames, the preparation method comprising the following steps:

[0070] By weight, subject 10 parts of graphene to plasma treatment for 3 min under the condition of a power of 70 W, then mix it with 11 parts of (3-aminopropyl)triethoxysilane, and stir at a speed of 200 r / min for 20 min to obtain modified graphene;

[0071] Under the protection of nitrogen by weight ratio, add 15 parts of isophorone diisocyanate to 5 parts of polyetheramine, at 65 °C, treat it at a stirring speed of 200 r / min for 2 h, then add 8 parts of 4,4'-dithiobisbenzoic acid, 0.8 part of dibutyltin dilaurate and 7 parts of sodium dodecylbenzenesulfonate, raise the temperature to 85 °C, continue to stir for 2 h, cool down to 45 °C, add 2 parts of triethanolamine and an appropriate amount of water, stir for 15 min to obtain a polymer emulsion; then add 45 parts of methyl methacrylate, 20 parts of ethyl methacrylate, 9 parts of acrylic acid and 5 parts of benzoyl peroxide to 20 parts of the polymer emulsion, at 70 °C, stir at a speed of 150 r / min for 1 h, and then stand for curing for 3 h, and after drying, obtain a microcapsule repair agent;

[0072] By weight ratio, mix 18 parts of random copolymer of acrylic acid and acrylamide with 15 parts of 2-ethyl-4-methylimidazole and 1 part of N,N'-methylenebisacrylamide, stir at a speed of 150 r / min for 10 min, then add 3 parts of silane-modified nano-zinc oxide, and continue to stir at 65 °C for 2 h to obtain a catalytic response agent;

[0073] By weight ratio, 60 parts of aqueous fluorocarbon resin emulsion, 7 parts of modified graphene, 4 parts of 2-(2H-benzotriazol-2-yl)-4-methylphenol, 5 parts of nano-cerium dioxide, 3 parts of polyvinyl alcohol, 3 parts of aliphatic polyisocyanate, 0.5 part of polyether-modified silicone and 7 parts of deionized water are added to a stirring kettle, stirred at a speed of 500 r / min for 40 min, then 7 parts of catalytic responsive agent, 8 parts of propylene glycol monobutyl ether and 10 parts of pigment filler are added, and stirring is continued for 12 min. Then 15 parts of microcapsule repair agent are added, and stirred at a speed of 100 r / min for 15 min to obtain a protective coating for wind power aluminum frames.

[0074] Comparative Example 1:

[0075] Compared with Example 3, modified graphene was not added in Comparative Example 1, and the others were the same as in Example 3.

[0076] Comparative Example 2:

[0077] Compared with Example 3, the ultraviolet absorber was not added in Comparative Example 2, and the others were the same as in Example 3.

[0078] Comparative Example 3:

[0079] Compared with Example 3, nano-cerium dioxide was not added in Comparative Example 3, and the others were the same as in Example 3.

[0080] Comparative Example 4:

[0081] Compared with Example 3, the preparation method of the microcapsule repair in Comparative Example 5 was different. The preparation method of the microcapsule repair agent in Comparative Example 4 was as follows:

[0082] By weight ratio, under the protection of nitrogen, 15 parts of isophorone diisocyanate are added to 5 parts of polyetheramine, and treated at a stirring speed of 150 r / min at 65 °C for 2 h. Then 7 parts of 4,4'-dithiobisbenzoic acid, 0.7 part of dibutyltin dilaurate and 6 parts of sodium dodecylbenzenesulfonate are added, the temperature is raised to 80 °C, and stirring is continued for 2 h. The temperature is lowered to 40 °C, 2 parts of triethanolamine and an appropriate amount of water are added, and stirred for 15 min to obtain a polymer emulsion; then 65 parts of methyl methacrylate, 6 parts of acrylic acid and 5 parts of benzoyl peroxide are added to 20 parts of the polymer emulsion, and stirred at a speed of 150 r / min at 60 °C for 1 h, and then left to stand and cure for 3 h. After drying, a microcapsule repair agent is obtained.

[0083] Comparative Example 5:

[0084] Compared with Example 3, the preparation method of the microcapsule repair in Comparative Example 5 was different. The preparation method of the microcapsule repair agent in Comparative Example 5 was as follows:

[0085] By weight, under the protection of nitrogen, isophorone diisocyanate was added to polyetheramine, and under the conditions of 60 °C to 65 °C, it was treated at a stirring speed of 100 r / min to 200 r / min for 1 h to 3 h. Then, 4,4'-dithiobibenzoic acid, a catalyst, and an emulsifier were added, the temperature was raised to 80 °C to 90 °C, and stirring treatment was continued for 1 h to 2 h. The temperature was lowered to 40 °C to 50 °C, triethanolamine and an appropriate amount of water were added, and stirring was carried out for 10 min to 20 min to obtain a polymer emulsion; then 30 parts of sodium alginate solution was added to the polymer emulsion, and spray drying treatment was carried out to obtain a microcapsule repair agent.

[0086] Comparative Example 6:

[0087] Compared with Example 3, the microcapsule repair agent was not added in Comparative Example 6, and the others were the same as in Example 3.

[0088] Comparative Example 7:

[0089] Compared with Example 3, 2-ethyl-4-methylimidazole was not added to the catalytic responsive agent in Comparative Example 7, and the others were the same as in Example 3.

[0090] Comparative Example 8:

[0091] Compared with Example 3, silane-modified nano zinc oxide was not added to the catalytic responsive agent in Comparative Example 8, and the others were the same as in Example 3.

[0092] Comparative Example 9:

[0093] Compared with Example 3, the catalytic responsive agent was not added in Comparative Example 9, and the others were the same as in Example 3.

[0094] The protective coating samples for wind power aluminum frames prepared in Examples 1 to 3 and the comparative samples of protective coatings for wind power aluminum frames prepared in Comparative Examples 1 to 9 were subjected to a salt spray test. The thickness of all coatings was kept consistent, the temperature was set at 35 °C, continuous spraying was carried out, and the salt spray settlement was 2 mL / h; the salt spray test solution was a 4 wt% aqueous sodium chloride solution. The coating samples and the comparative samples were observed on time to observe whether there were abnormal phenomena such as rusting, cracking, blistering, bulging, and peeling of the coatings. The results are shown in Table 1.

[0095] It should be noted that the protective coating samples of the present application and the comparative samples of the protective coatings of the comparative examples were used as primers. The preparation method of the topcoat paint was as follows: 20 parts of hydroxymethylacrylamide, 10 parts of aliphatic glycidyl ether epoxy resin, 5 parts of acrylic resin, 6 parts of styrene, 5 parts of isocyanate, 1 part of polydimethylsiloxane, and 5 parts of barium sulfate were added to a mixing kettle and stirred at a speed of 500 r / min for 3 h to obtain the topcoat paint. When coating, the thickness of the coatings formed by the samples of the protective coatings in Examples 1 to 3 was 50 μm, and the thickness of the topcoat paint formed was 10 μm.

[0096] Table 1: Salt spray resistance test results

[0097]

[0098]

[0099] From the data analysis in Table 1, the coating formed by the paint of the present invention has excellent salt spray resistance. The combined use of components helps to provide the corrosion resistance of the coating, and further helps to improve the environmental tolerance of the coating, and has a longer service life in a high salt spray environment.

[0100] In addition, the following self-healing performance tests were also carried out to detect the coating scratch repair time at different temperatures. The specific method is as follows: the coating thickness of all coating samples and the comparison samples is kept the same. Use the same tool to draw a "one"-shaped scratch on the coating sample board, with a length of 2 cm. Then place the coating samples and the comparison samples in different temperature environments to detect the scratch repair time of the coating samples and the comparison samples. The scratch disappears completely visible to the naked eye. The results are shown in Table 2.

[0101] Table 2: Self-healing performance test results

[0102]

[0103]

[0104] From the data analysis in Table 2, it can be seen that the paint of the present invention has an obvious repair effect. The added microcapsule repair agent has excellent compatibility and contains dynamic disulfide bonds. When the coating is damaged or the environmental pH changes, it can interact with the catalytic responder in time, trigger the disulfide bond exchange, play a certain self-healing effect, and thus reduce the maintenance cost and help to improve the service life of the wind power aluminum frame.

[0105] To further illustrate the present application, it is also combined with Figure 1 and Figure 2 to analyze the present application. Figure 1 is a schematic diagram of the protective paint sample for the wind power aluminum frame prepared in Example 3 of the present invention. From Figure 1 it can be seen that the microcapsule repair agent of the present invention is evenly distributed in the paint system in a spherical shape. The average particle size of the microcapsule repair agent is 40 μm, the average wall thickness is 1.2 μm, and the rupture pressure ≥ 5 MPa, which has relatively excellent strength and dispersion, and excellent stability in the system. Figure 2 is an application schematic diagram of the protective paint in Example 3 of the present invention. From Figure 2It can be seen that when the protective coating of the present application is used as a primer, a primer layer 2 is formed on the surface of the aluminum substrate 1, and microcapsule repair agents are evenly distributed in the primer layer. Then, a topcoat layer 3 is formed on the surface of the primer layer 2. It has strong operability, can effectively extend the service life of the aluminum substrate, and can achieve a self-repairing effect.

[0106] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered to be within the scope described in this specification.

[0107] The above-described embodiments merely represent several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A protective coating for a wind power aluminum frame, characterized in that, The protective coating comprises the following raw materials for preparation in parts by weight: 50 to 70 parts of aqueous fluorocarbon resin emulsion, 3 to 7 parts of modified graphene, 10 to 20 parts of microcapsule repair agent, 3 to 7 parts of catalytic responder, 1 to 5 parts of ultraviolet absorber, 3 to 9 parts of film-forming agent, 3 to 7 parts of nano cerium dioxide, 1 to 3 parts of dispersant, 2 to 5 parts of curing agent, 0.1 to 0.5 part of defoaming agent, 0 to 20 parts of pigment extender, and 5 to 10 parts of deionized water.

2. The protective coating according to claim 1, characterized in that, The preparation method of the microcapsule repair agent is as follows: Under the protection of nitrogen, isophorone diisocyanate is added to polyetheramine, and under the conditions of 60°C to 65°C, it is treated at a stirring speed of 100 r / min to 200 r / min for 1 h to 3 h, then 4,4'-dithiobenzoic acid, a catalyst, and an emulsifier are added, the temperature is raised to 80°C to 90°C, and stirring treatment is continued for 1 h to 2 h. The temperature is lowered to 40°C to 50°C, triethanolamine and an appropriate amount of water are added, and stirring is carried out for 10 min to 20 min to obtain a polymer emulsion; Methyl methacrylate, ethyl methacrylate, acrylic acid, and benzoyl peroxide are added to the polymer emulsion, and under the conditions of 55°C to 70°C, stirring treatment is carried out at a rotation speed of 150 r / min to 300 r / min for 1 to 2 h, and then it is allowed to stand and cure for 3 h to 5 h. After drying, a microcapsule repair agent is obtained.

3. The protective coating according to claim 2, wherein, The weight part ratio of the isophorone diisocyanate, polyetheramine, 4,4'-dithiobenzoic acid, catalyst, emulsifier, and triethanolamine is (10 to 15):(3 to 5):(5 to 9):(0.1 to 0.8):(3 to 7):(1 to 2).

4. The protective coating according to claim 3, wherein The weight part ratio of the methyl methacrylate, ethyl methacrylate, acrylic acid, benzoyl peroxide, and polymer emulsion is (40 to 50):(20 to 30):(5 to 9):(3 to 7):(12 to 20).

5. The protective coating according to claim 1, characterized in that, The preparation method of the catalytic responder is as follows: An amorphous copolymer of acrylic acid and acrylamide is mixed with 2-ethyl-4-methylimidazole and N,N'-methylenebisacrylamide, and stirring treatment is carried out at a rotation speed of 100 r / min to 200 r / min for 10 min to 20 min, then silane-modified nano zinc oxide is added, and at 60°C to 70°C, stirring treatment is continued for 1 h to 3 h to obtain a catalytic responder.

6. The protective coating according to claim 5, characterized in that, The weight part ratio of the amorphous copolymer of acrylic acid and acrylamide, 2-ethyl-4-methylimidazole, N,N'-methylenebisacrylamide, and silane-modified nano zinc oxide is (10 to 20):(10 to 15):(0.5 to 3):(1 to 5).

7. The protective coating according to claim 1, characterized in that, The ultraviolet absorber is at least one of 2-(2H-benzotriazol-2-yl)-4-methylphenol and 2-hydroxy-4-methoxybenzophenone.

8. The protective coating according to claim 1, characterized in that, The film-forming agent is at least one of ethylene glycol monobutyl ether, propylene glycol monobutyl ether, and dipropylene glycol monobutyl ether.

9. The protective coating according to claim 1, characterized in that, The dispersant is at least one of polyvinyl alcohol and carboxymethyl cellulose.

10. A preparation method of a protective coating for a wind power aluminum frame, characterized in that, The preparation method is used to prepare the protective coating as described in any one of claims 1 to 9, and the preparation method comprises the following steps: Add the aqueous fluorocarbon resin emulsion, modified graphene, ultraviolet absorber, nano-ceria, dispersant, curing agent, defoamer and deionized water to a stirring kettle, stir at a speed of 500 r / min to 1000 r / min for 30 min to 60 min, then add the catalytic responder, film-forming agent and pigment filler, continue stirring for 10 min to 15 min, and then add the microcapsule repair agent, stir at a speed of 100 r / min to 150 r / min for 10 min to 30 min to obtain the protective coating for the wind power aluminum frame.

Images