Anticorrosion and cleaning protection nano coating and construction method thereof

Abstract

The present application relates to the technical field of railway equipment maintenance, and discloses a kind of anticorrosive and clean nano coating and its construction method, anticorrosive and clean nano coating includes sequentially arranged bottom layer, intermediate layer and surface layer from bottom to top, the raw material of bottom layer includes A component and B component;A component includes epoxy resin, toughening agent, pigment, chelating agent, thixotropic agent and first diluent;B component includes phenolic amine resin, bottom layer catalyst drier, functionality regulator and second diluent, the raw material of intermediate layer includes C component and D component;C component includes hydroxyl acrylic acid resin, anti-aging agent, pigment, auxiliary agent, thixotropic agent and third diluent;D component includes hexamethylene diisocyanate, intermediate layer catalyst drier and fourth diluent.Through the above technical scheme, the problem of low hardness, coating easy to fall off and poor corrosion resistance of anticorrosive coating in related art is solved.

Description

Technical Field

[0001] This invention relates to the field of railway equipment maintenance technology, specifically to an anti-corrosion and cleaning nano-coating and its construction method. Background Technology

[0002] Currently, the commonly used anti-corrosion material in anti-corrosion construction projects is various colors of alkyd enamel paint, generally using a primer-topcoat combination. Its main components are 30%~60% alkyd resin, 10%~25% pigment, 0%~25% filler, 1%~8% additives, and 30%~55% solvent. Preparation method: Under high-speed mixing, the raw materials (excluding the drier and anti-skinning agent in the additives) are added to containers according to the specified proportions. After stirring evenly, the mixture is ground to the standard fineness using a grinder. Once qualified, the paint viscosity is adjusted to the standard, and then the drier and anti-skinning agent are added. After inspection and approval, it is packaged. During coating application, a primer-topcoat combination method is generally used on-site, employing a brush application with a cross-hatching technique. There are no requirements for coating thickness, but the appearance quality is specified, and the anti-corrosion life is ≥1 year.

[0003] The railway transportation industry is characterized by the continuity of train operations, the wide geographical distribution of track lines, and the complex climatic environments of the areas traversed. Corrosion protection, maintenance, and repair of related equipment and facilities along the lines can only be carried out through emergency repairs during train intervals (also known as maintenance windows).

[0004] Existing anti-corrosion coatings have the following problems when used for railway equipment maintenance:

[0005] (1) The coating has low hardness (≤HB) and poor stain resistance. It is not good for outdoor use and will lose its gloss and powder after one year and rust after two years, requiring rework. The equipment is made of cast iron, non-ferrous metals and non-metals, so there is a phenomenon of coating peeling.

[0006] (2) The coating dries slowly. On the one hand, it cannot meet the characteristics of the "maintenance window" of railway equipment. On the other hand, the speeding trains cause sand and dust to fly along the line, which will cause sand and dust particles to adhere to the coating surface, reducing the appearance quality and protective performance of the coating.

[0007] In addition, the electrical equipment distributed along the railway line is designed to have a service life of 20 years. If the average anti-corrosion cycle is two years, the anti-corrosion frequency during the equipment's service life needs to be 8 times, which is time-consuming and labor-intensive. Summary of the Invention

[0008] This invention proposes an anti-corrosion and cleaning nano-coating and its construction method, which solves the problems of low hardness, easy peeling and poor anti-corrosion performance of anti-corrosion coatings in related technologies.

[0009] The technical solution of the present invention is as follows:

[0010] This invention proposes an anti-corrosion and cleaning-protecting nano-coating, comprising a bottom layer, an intermediate layer, and a top layer arranged sequentially from bottom to top.

[0011] The raw materials of the bottom layer include component A and component B;

[0012] Component A comprises epoxy resin, toughening agent, pigment, chelating agent, thixotropic agent, and a first diluent, wherein the mass of the first diluent is ≤ 18% of the mass of component A; Component B comprises phenolic amine resin, underlayer drying agent, functionality modifier, and a second diluent, wherein the mass of the second diluent accounts for 30% to 45% of the mass of component B.

[0013] The raw materials for the intermediate layer include component C and component D;

[0014] Component C comprises hydroxyl acrylic resin, anti-aging agent, pigment, additives, thixotropic agent, and a third diluent, wherein the mass of the third diluent is ≤25% of the mass of component C; Component D comprises hexamethylene diisocyanate, intermediate layer drier, and a fourth diluent, wherein the mass of the fourth diluent accounts for 30%~45% of the mass of component D.

[0015] The raw materials for the surface layer include component E and component F;

[0016] The E component includes hydroxyl acrylic resin, anti-aging agent, pigment, additive, surfactant, microcrystalline wax and fifth diluent, wherein the mass of the fifth diluent accounts for 20% to 30% of the mass of the E component; the F component includes hexamethylene diisocyanate, surface drying agent and sixth diluent, wherein the mass of the sixth diluent accounts for 35% to 45% of the mass of the F component.

[0017] In this invention, thixotropic agents are added to the raw materials of the base layer, which greatly increases the thickness of a single spray application. This prevents sagging when the base layer thickness is ≤200μm, thus solving the problem that in the prior art, when anti-corrosion coatings are applied in a single layer with a thickness ≥50μm to adapt to the characteristics of railway equipment maintenance "maintenance windows," sagging easily leads to increased coating defects and reduced coating anti-corrosion life.

[0018] In this invention, a chelating agent is added to the bottom layer of raw materials. The chelating agent can chelate with metal ions on the surface of the equipment, thereby improving the adhesion to the equipment surface. The chelating agent can be any chelating agent known in the art, such as zinc salt chelating agents (including zinc ethylenediaminetetraacetate, zinc phosphate, tetrabasic zinc chromate, etc.), organic acid chelating agents (including citric acid, oxalic acid, tartaric acid, malic acid, etc.), amine chelating agents (including triethanolamine, triethylenetetramine, etc.), and guanidine chelating agents (e.g., diphenylguanidine chromate). Preferably, it is a composite chelating agent composed of tetrabasic zinc chromate and diphenylguanidine chromate in a mass ratio of 1~9:9~1.

[0019] When a composite chelating agent consisting of zinc salt chelating agent and guanidine chelating agent is selected as the chelating agent, the adhesion to the equipment surface can be further improved.

[0020] As a further technical solution, the mass ratio of component A to component B is 8:1, the mass ratio of component C to component D is 8:1, and the mass ratio of component E to component F is 3:1.

[0021] In this invention, the toughening agent has good toughness and can play a toughening role on epoxy resin. The toughening agent can be any toughening agent known in the art, such as HK-10, AS-800, ZG-8013, ZG-8020, etc., with ZG-8020 being preferred.

[0022] When ZG-8020 is selected as the toughening agent, the toughness of the coating can be further improved.

[0023] As a further technical solution, component A includes the following raw materials in parts by weight: 30-42 parts epoxy resin, 5-12 parts toughening agent, 25-35 parts pigment, 8-15 parts chelating agent, 4-8 parts thixotropic agent, and 1-18 parts first diluent.

[0024] The B component comprises the following raw materials in parts by weight: 45-60 parts of phenolic amine resin, 2-5 parts of bottom drying agent, 0-8 parts of functionality regulator, and 30-45 parts of second diluent.

[0025] The C component comprises the following raw materials in parts by weight: 45-55 parts of hydroxy acrylic resin, 5-8 parts of anti-aging agent, 15-25 parts of pigment, 2-6 parts of additives, 2-3 parts of thixotropic agent, and 1-25 parts of third diluent.

[0026] The D component comprises the following raw materials in parts by weight: 45-60 parts of hexamethylene diisocyanate, 2-10 parts of intermediate layer drying agent, and 30-45 parts of fourth diluent;

[0027] The E component comprises the following raw materials in parts by weight: 45-60 parts of hydroxy acrylic resin, 5-8 parts of anti-aging agent, 0-5 parts of pigment, 2-3 parts of additives, 6-10 parts of surfactant, 2-5 parts of microcrystalline wax, and 20-30 parts of fifth diluent.

[0028] The F component comprises the following raw materials in parts by weight: 50-60 parts of hexamethylene diisocyanate, 2-5 parts of surface drying agent, and 35-45 parts of sixth diluent.

[0029] In this invention, the addition of a surfactant to the surface layer improves the surface tension of the coating, allowing dust on the coating surface to be washed away by rain, thus giving the coating good self-cleaning properties. The surfactant can be any surfactant known in the art, such as alkyl glycosides, polyether-modified silicone oils, or organosilicon surfactants (e.g., BYK-346).

[0030] In this invention, the addition of a functionality modifier to the surface layer can optimize the crosslinking density, curing speed, and hardness of the epoxy resin. The functionality modifier can be any known functionality modifier in the art, such as methyl methacrylate, dimethylamine, diethylenetriamine, dimethyldiethanolamine, triethylenetetramine, etc., with triethylenetetramine being preferred.

[0031] As a further technical solution, the microcrystalline wax is a microcapsule-encapsulated modified microcrystalline wax, wherein the wall material of the microcapsule-encapsulated modified microcrystalline wax is polyacrylonitrile, and the mass ratio of the raw material polyacrylonitrile to the microcrystalline wax is 1:10~20.

[0032] In this invention, modified microcrystalline wax is encapsulated in microcapsules, which slowly releases the wax to the coating surface, thereby achieving long-lasting self-cleaning of the coating and further improving the service life of the anti-corrosion coating. Using polyacrylonitrile as the wall material, it also works synergistically with the hydroxyl acrylic resin in the surface layer to further improve the aging resistance and acid and alkali resistance of the anti-corrosion coating.

[0033] As a further technical solution, the preparation method of the microcapsule-encapsulated modified microcrystalline wax is as follows: dispersing microcrystalline wax in vegetable oil containing glyceryl stearate to obtain a core material solution, dissolving polyacrylonitrile in DMF to obtain a wall material solution, adding the core material solution to the wall material solution, ultrasonically dispersing, and drying to allow DMF to evaporate, thereby obtaining microcapsule-encapsulated modified microcrystalline wax.

[0034] As a further technical solution, the first diluent and the second diluent are each independently composed of the following components by weight percentage:

[0035] Toluene 50%~70%, butanol 15%~30%, ethylene glycol butyl ether 10%~20%;

[0036] The third, fourth, fifth, and sixth diluents each independently consist of the following components by weight percentage: xylene 40%~60%, anhydrous butyl acetate 30%~40%, and cyclohexanone 0~30%.

[0037] In this invention, by changing the diluent in different coatings and utilizing the different evaporation rates of the diluent in different coatings, a "wet-on-wet" coating process is achieved during construction. This significantly improves construction efficiency while ensuring quality standards are met, and also further enhances aging resistance.

[0038] In this invention, epoxy resin is used as the base material, which has good adhesion to the equipment surface and high impact strength. The epoxy resin selected is a bisphenol A type epoxy resin, such as epoxy resin E44 and epoxy resin E51.

[0039] As a further technical solution, the epoxy resin includes epoxy resin E44 and epoxy resin E51 in a mass ratio of 1:1 to 5.

[0040] In this invention, epoxy resin E44 and epoxy resin E51 are compounded in a mass ratio of 1:1 to 5, which further improves the adhesion between the substrate and the equipment surface and the impact strength of the coating.

[0041] As a further technical solution, the preparation method of component A includes the following steps:

[0042] A1. Mix the thixotropic agent with 25%~35% by mass of the first diluent, stir well and activate to obtain the thixotropic agent prepolymer;

[0043] A2. After mixing epoxy resin and toughening agent, add pigment, chelating agent, additives and the remaining mass of first diluent, mix evenly to obtain a mixture.

[0044] A3. Add the thixotropic agent prepolymer to the mixture and mix thoroughly to obtain component A.

[0045] As a further technical solution, the preparation method of component A includes the following steps:

[0046] A1. Mix the thixotropic agent with 25%~35% by mass of the first diluent and stir at 800~1000 rpm and 70~90℃ for 0.5~1 h to activate it and obtain the thixotropic agent prepolymer;

[0047] A2. After mixing epoxy resin and toughening agent, add pigment, chelating agent, additives and the remaining mass of first diluent, mix at 1500~2500 rpm for 0.5~1h until uniformly mixed to obtain a mixture, and grind to a fineness ≤50μm;

[0048] A3. Add the thixotropic agent prepolymer to the mixture at 1500 rpm, increase the speed to 2500 rpm and mix for 0.5~1h until the mixture is uniform to obtain component A.

[0049] As a further technical solution, the preparation method of component C includes the following steps:

[0050] C1. Add pigments, additives, anti-aging agents, thixotropic agents and 25%~35% by mass of a third diluent to hydroxyl acrylic resin and mix evenly to obtain a preliminary mixture;

[0051] C2. Add the remaining mass of the third diluent to the initial mixture, mix well, and obtain component C.

[0052] As a further technical solution, the preparation method of component C includes the following steps:

[0053] C1. Add pigments, additives, anti-aging agents, thixotropic agents and 25%~35% by mass of a third diluent to hydroxyl acrylic resin and mix them evenly at 1500~2500 rpm for 0.5~1h to obtain a preliminary mixture, and grind it to a fineness ≤20μm.

[0054] C2. At 1500 rpm, add the remaining mass of the third diluent to the initial mixture, increase the speed to 2500 rpm and mix for 0.5~1h until the mixture is uniform to obtain component C.

[0055] As a further technical solution, the preparation method of component E includes the following steps:

[0056] E1. Mix the surfactant and the fifth diluent at a mass ratio of 1:1 to obtain the first mixture;

[0057] E2. Add pigments, additives, anti-aging agents, thixotropic agents and 25%~35% by mass of the fifth diluent to the hydroxyl acrylic resin and mix evenly to obtain the second mixture;

[0058] E3. Add the first mixture and microcrystalline wax to the second mixture, mix evenly, and obtain the third mixture;

[0059] E4. Add the remaining mass of the fifth diluent to the third mixture, mix well, and obtain component E.

[0060] As a further technical solution, the preparation method of component E includes the following steps:

[0061] E1. Mix the surfactant and the fifth diluent at a mass ratio of 1:1 to obtain the first mixture;

[0062] E2. Add pigments, additives, anti-aging agents, thixotropic agents and 25%~35% by mass of the fifth diluent to the hydroxyl acrylic resin, and mix at 1000 rpm for 0.5~1 h until the mixture is uniform to obtain the second mixture;

[0063] E3. Add the first mixture and microcrystalline wax to the second mixture, and disperse and mix at 1500~2000 rpm for 0.5~1h until the fineness is ≤20μm to obtain the third mixture;

[0064] E4. Add the remaining mass of the fifth diluent to the third mixture, mix well, and obtain component E.

[0065] This invention also proposes a method for applying the aforementioned anti-corrosion and cleaning-protecting nano-coating, comprising the following steps:

[0066] S1. Mix and stir components A and B to obtain the base coat. Apply one coat of the base coat to the surface of the equipment using a cross-spraying method.

[0067] S2. Mix and stir components C and D to obtain an intermediate layer coating. Apply the intermediate layer coating to the surface of the base layer coating using a cross-spraying method.

[0068] S3. After mixing and stirring components E and F, a topcoat is obtained. The topcoat is then sprayed onto the surface of the intermediate coating using a cross-spraying method to obtain an anti-corrosion and cleaning nano-coating.

[0069] In this invention, the base coat, intermediate coat, and top coat are all applied using wet-on-wet spraying, which is suitable for the "maintenance windows" of railway equipment and ensures that the construction quality meets the standards. The cross-hatching method refers to applying the coatings sequentially in one direction first, and then applying a wet-on-wet coat in an approximately perpendicular direction. The use of the cross-hatching method for the base coat, intermediate coat, and top coat achieves uniform coating thickness and minimizes surface defects.

[0070] As a further technical solution, based on wet film thickness, the coating thickness of the bottom layer is 120~180μm, the coating thickness of the intermediate layer is 80~100μm, and the coating thickness of the top layer is 30~50μm.

[0071] The working principle and beneficial effects of this invention are as follows:

[0072] In this invention, the anti-corrosion and cleaning nano-coating adopts a composite coating form, including a base layer, an intermediate layer, and a top layer. The base layer uses epoxy resin as a base material, which improves the impact strength of the coating. The intermediate layer and the top layer both use hydroxyl acrylic resin as a base material, which not only improves the weather resistance of the coating, but also, in combination with the epoxy resin of the base layer, further improves the impact strength and anti-corrosion performance of the coating. This makes the resulting coating less prone to peeling and has an anti-corrosion life of 5-8 years. By limiting the content of diluent in the base layer, intermediate layer, and top layer, the density and hardness of the coating are improved, thereby solving the problems of low hardness, easy peeling, and poor anti-corrosion performance of existing anti-corrosion coatings. Detailed Implementation

[0073] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0074] The type and composition information of each raw material in the following examples and comparative examples are as follows:

[0075] The toughening agent, model ZG8020, was purchased from Shanghai Zhongyan Biotechnology Co., Ltd.

[0076] Hydroxy acrylic resin, model GS-359;

[0077] The anti-aging agent is a mixture of antioxidant 1010 and ultraviolet absorber UV329 in a 1:1 mass ratio, both purchased from Changzhou Youfeng Chemical Co., Ltd.

[0078] The bottom drying agent is K54 accelerator, purchased from Suzhou Hengsite Industrial Co., Ltd.

[0079] Both the intermediate layer drying agent and the surface layer drying agent are T-12 drying agents;

[0080] Phenolic amine resins use phenolic amine T31 curing agent;

[0081] The surfactant model is BYK-346;

[0082] The functionality modifier is triethylenetetramine.

[0083] The microcapsule-encapsulated modified microcrystalline wax was prepared by the following method: 15g of microcrystalline wax was dispersed in 100mL of vegetable oil containing 2g of glyceryl monostearate to obtain a core material solution; 1g of polyacrylonitrile was dissolved in 500mL of DMF to obtain a wall material solution; the core material solution was added to the wall material solution; after ultrasonic dispersion, the mixture was dried to allow the DMF to evaporate, resulting in the microcapsule-encapsulated modified microcrystalline wax. The weight-average molecular weight of the polyacrylonitrile was 100,000.

[0084] Diluent X1 consists of the following components by weight percentage: 50% toluene, 30% butanol, and 20% ethylene glycol butyl ether;

[0085] Diluent X2 consists of the following components by weight percentage: 70% toluene, 15% butanol, and 15% ethylene glycol butyl ether;

[0086] Diluent X3 consists of the following components by weight percentage: 70% toluene, 15% anhydrous butyl acetate, and 15% ethylene glycol butyl ether;

[0087] Diluent Y1 consists of the following components by weight percentage: xylene 40%, anhydrous butyl acetate 30%, and cyclohexanone 30%;

[0088] Diluent Y2 consists of the following components by weight percentage: xylene 60%, anhydrous butyl acetate 30%, and cyclohexanone 10%;

[0089] Diluent Y3 consists of the following components by weight percentage: xylene 60%, anhydrous butyl acetate 30%, and ethylene glycol butyl ether 10%;

[0090] In the following examples and comparative examples, the preparation methods of each component in the raw materials of the bottom layer, intermediate layer, and top layer of the anti-corrosion and cleaning nano-coating are as follows:

[0091] The preparation of component A includes the following steps:

[0092] A1. Mix the thixotropic agent with 30% by mass of the first diluent and stir at 1000 rpm and 80°C for 0.5 h to obtain the thixotropic agent prepolymer;

[0093] A2. After mixing epoxy resin and toughening agent, add pigment, chelating agent, additives and the remaining mass of first diluent, mix at 2000 rpm for 1 hour until uniformly mixed to obtain a mixture, and grind to a fineness ≤50μm;

[0094] A3. Add the thixotropic agent prepolymer to the mixture at 1500 rpm, increase the speed to 2500 rpm and mix for 1 hour until the mixture is uniform to obtain component A.

[0095] The preparation of component B includes the following steps: mixing phenolic amine resin, bottom drying agent, functionality regulator and second diluent evenly to obtain component B.

[0096] The preparation of component C includes the following steps:

[0097] C1. Add pigment, additives, anti-aging agent, thixotropic agent and 25%~35% by mass of third diluent to hydroxy acrylic resin and mix evenly at 2000 rpm for 0.5 h to obtain a preliminary mixture, and grind it to a fineness ≤20μm;

[0098] C2. At 1500 rpm, add the remaining mass of the third diluent to the initial mixture, increase the speed to 2500 rpm and mix for 1 hour until the mixture is uniform to obtain component C.

[0099] The preparation of component D includes the following steps: mixing hexamethylene diisocyanate, intermediate layer drying agent and fourth diluent evenly to obtain component D.

[0100] The preparation of component E includes the following steps:

[0101] E1. Mix the surfactant and the fifth diluent at a mass ratio of 1:1 to obtain the first mixture;

[0102] E2. Add pigment, additives, anti-aging agent, thixotropic agent and 30% by mass of fifth diluent to hydroxy acrylic resin, and mix at 1000 rpm for 1 hour until uniformly mixed to obtain the second mixture;

[0103] E3. Add the first mixture and microcrystalline wax to the second mixture, and disperse and mix at 2000 rpm for 1 hour until the fineness is ≤20μm to obtain the third mixture;

[0104] E4. Add the remaining mass of the fifth diluent to the third mixture, mix well, and obtain component E.

[0105] The preparation of component F includes the following steps: mixing hexamethylene diisocyanate, surface drying agent and sixth diluent evenly to obtain component F.

[0106] The application method for the anti-corrosion and cleaning nano-coating includes the following steps:

[0107] S1. Mix component A and component B at a mass ratio of 8:1 to obtain the base coat. Apply the base coat to the surface of the equipment using a cross-spraying method.

[0108] S2. Mix and stir components C and D at a mass ratio of 8:1 to obtain an intermediate layer coating. Apply the intermediate layer coating to the surface of the base layer coating using a cross-spraying method.

[0109] S3. Mix and stir components E and F at a mass ratio of 3:1 to obtain a topcoat. Apply the topcoat to the surface of the intermediate coating using a cross-spraying method to obtain an anti-corrosion and cleaning nano-coating.

[0110] Based on wet film thickness, the coating thickness of the bottom layer is 150 μm, the coating thickness of the intermediate layer is 80 μm, and the coating thickness of the top layer is 50 μm.

[0111] The test standards used for each performance data in the following embodiments and comparative examples are as follows:

[0112] (1) Adhesion: GB / T9286 Paints and Varnishes Cross-cut Test Method

[0113] (2) Impact strength: GB / T 1732 Test method for impact resistance of coating film

[0114] (3) Hardness: GB / T 6739 Coating Hardness Test by Pencil Test

[0115] (4) Aging resistance: GB / T 1865 Paints and varnishes, artificial climate aging method

[0116] (5) Acid and alkali resistance: GB / T 9274 Determination of resistance to liquid media of paints and varnishes

[0117] The raw material compositions of the bottom layer, intermediate layer, and top layer in the anti-corrosion and cleaning nano-coatings of Examples 1-3 are shown in Tables 1-3 below:

[0118] Table 1. Raw material composition (by mass percentage) of the anti-corrosion and cleaning nano-coating substrate in Examples 1-3.

[0119]

[0120] Table 2. Raw material composition of the intermediate layer of the anti-corrosion and cleaning nano-coating in Examples 1-3 (by mass percentage, %)

[0121]

[0122] Table 3. Raw material composition (by mass percentage) of the anti-corrosion and cleaning nano-coating surface layer in Examples 1-3.

[0123]

[0124] The performance test results of the bottom layer, intermediate layer and top layer of the anti-corrosion and cleaning nano-coatings in Examples 1-3 are shown in Table 4:

[0125] Table 4 Performance test results of the bottom layer, intermediate layer and top layer of the anti-corrosion and cleaning nano-coatings in Examples 1-3

[0126]

[0127] The results of the annual aging and acid and alkali resistance tests of the anti-corrosion and cleaning nano-coatings of Examples 1-3 are shown in Table 5:

[0128] Table 5 Performance test results of the anti-corrosion and cleaning-protecting nano-coatings in Examples 1-3

[0129]

[0130] Comparative Example 1

[0131] In Example 1, the hydroxyl acrylic resin in layer C was replaced with an equal amount of epoxy resin E44, and all other raw materials were the same as in Example 1.

[0132] The aging resistance test results of the anti-corrosion and cleaning nano-coating were as follows: bubbling and powdering occurred after aging (800h).

[0133] The weather resistance test results of the anti-corrosion and cleaning nano-coating were as follows: both acid resistance (5% H2SO4, 72h) and alkali resistance (5% NaOH, 72h) showed abnormalities.

[0134] Comparative Example 2

[0135] In Example 1, the hydroxyl acrylic resin in layer E was replaced with an equal amount of epoxy resin E44, and all other raw materials were the same as in Example 1.

[0136] The aging resistance test results of the anti-corrosion and cleaning nano-coating were as follows: blistering, cracking and peeling occurred after aging (800h).

[0137] The weather resistance test results of the anti-corrosion and cleaning nano-coating were as follows: both acid resistance (5% H2SO4, 72h) and alkali resistance (5% NaOH, 72h) showed abnormalities.

[0138] Comparative Example 3

[0139] The amount of the first diluent in component A of Example 1 was increased to 20%, the amount of pigment was reduced to 25%, and the remaining raw materials were the same as in Example 1.

[0140] The hardness test result of the bottom layer is 2H.

[0141] Comparative Example 4

[0142] The amount of the third diluent in layer C of Example 1 was increased to 30%, the amount of pigment was reduced to 8%, and the remaining raw materials were the same as in Example 1.

[0143] The hardness test result of the intermediate layer is 1H.

[0144] Comparative Example 5

[0145] In Example 1, the amount of the fifth diluent in layer E was reduced to 18%, the amount of pigment was increased to 3%, and the remaining raw materials were the same as in Example 1.

[0146] The surface layer hardness test result is: 1H.

[0147] Example 4

[0148] The only difference between this embodiment and Embodiment 1 is that the epoxy resin is epoxy resin E51.

[0149] The adhesion and impact strength test results of the bottom layer are as follows: adhesion is level 2, and impact strength is 50 kg·cm.

[0150] Example 5

[0151] The only difference between this embodiment and Embodiment 1 is that the epoxy resin is a mixture of epoxy resins E44 and E51 in a mass ratio of 3:1.

[0152] The adhesion and impact strength test results of the bottom layer are as follows: adhesion is grade 1, and impact strength is 50 kg·cm.

[0153] Example 6

[0154] The only difference between this embodiment and Embodiment 1 is that the epoxy resin is a mixture of epoxy resins E44 and E51 in a mass ratio of 1:3.

[0155] The adhesion and impact strength test results of the bottom layer are as follows: adhesion is grade 1, and impact strength is 50 kg·cm.

[0156] Example 7

[0157] The only difference between this embodiment and Embodiment 1 is that the epoxy resin is a mixture of epoxy resins E44 and E51 in a mass ratio of 1:1.

[0158] The adhesion and impact strength test results of the substrate are as follows: the coating adhesion is grade 0 and the impact strength is 50 kg·cm.

[0159] Example 8

[0160] The only difference between this embodiment and Example 1 is that the chelating agent is diphenylguanidine chromate.

[0161] The adhesion test result for the bottom layer is: adhesion level 1.

[0162] Example 9

[0163] The only difference between this embodiment and Example 1 is that the chelating agent is a composite chelating agent with a mass ratio of tetrabasic zinc chrome yellow and diphenylguanidine chromate of 1:1.

[0164] The adhesion test result for the bottom layer is: adhesion level 0.

[0165] Example 10

[0166] The only difference between this embodiment and Example 1 is that the chelating agent is a composite chelating agent with a mass ratio of zinc phosphate and diphenylguanidine chromate of 1:1.

[0167] The adhesion test result for the bottom layer is: adhesion level 1.

[0168] Example 11

[0169] The only difference between this embodiment and Example 1 is that the chelating agent is a composite chelating agent with a mass ratio of 1:1 of zinc ethylenediaminetetraacetate and diphenylguanidine chromate.

[0170] The adhesion test result for the bottom layer is: adhesion level 1.

[0171] Example 12

[0172] The only difference between this embodiment and Embodiment 1 is that the microcrystalline wax is a microcapsule-encapsulated modified microcrystalline wax.

[0173] The aging resistance test results of the anti-corrosion and cleaning nano-coating are as follows: it does not bubble, crack, peel, or powder after aging (1200h).

[0174] The weather resistance test results of the anti-corrosion and cleaning nano-coating are as follows: there are no abnormalities in acid resistance (5% H2SO4, 156h) and alkali resistance (5% NaOH, 156h).

[0175] Example 13

[0176] The only difference between this embodiment and Embodiment 1 is that the first to sixth diluents are all diluent Y1.

[0177] The aging resistance test results of the anti-corrosion and cleaning nano-coating are as follows: it does not bubble, crack, peel, or powder after aging (800h).

[0178] Example 14

[0179] The only difference between this embodiment and Embodiment 1 is that the first to sixth diluents are all diluent Y2.

[0180] The aging resistance test results of the anti-corrosion and cleaning nano-coating are as follows: it does not bubble, crack, peel, or powder after aging (960h).

[0181] Example 15

[0182] The only difference between this embodiment and Embodiment 1 is that the first to sixth diluents are all diluent Y3.

[0183] The aging resistance test results of the anti-corrosion and cleaning nano-coating are as follows: it does not bubble, crack, peel, or powder after aging (800h).

[0184] Example 16

[0185] The only difference between this embodiment and Embodiment 1 is that the first and second diluents are diluent X1, and the third to sixth diluents are all diluent Y1.

[0186] The aging resistance test results of the anti-corrosion and cleaning nano-coating are as follows: it does not bubble, crack, peel, or powder after aging (1440h).

[0187] Example 17

[0188] The only difference between this embodiment and Embodiment 1 is that the first and second diluents are diluent X3, and the third to sixth diluents are all diluent Y1.

[0189] The aging resistance test results of the anti-corrosion and cleaning nano-coating are as follows: it does not bubble, crack, peel, or powder after aging (1080h).

[0190] Example 18

[0191] The only difference between this embodiment and Embodiment 1 is that the first and second diluents are diluent X1, and the third to sixth diluents are all diluent Y3.

[0192] The aging resistance test results of the anti-corrosion and cleaning nano-coating are as follows: it does not bubble, crack, peel, or powder after aging (960h).

[0193] Example 19

[0194] The only difference between this embodiment and Embodiment 1 is that the first and second diluents are diluent X2, and the third to sixth diluents are all diluent Y2.

[0195] The aging resistance test results of the anti-corrosion and cleaning nano-coating are as follows: it does not bubble, crack, peel, or powder after aging (1500h).

[0196] Example 20

[0197] The only difference between this embodiment and Embodiment 1 is that the first and second diluents are diluent X2, and the third to sixth diluents are all diluent Y3.

[0198] The aging resistance test results of the anti-corrosion and cleaning nano-coating are as follows: it does not bubble, crack, peel, or powder after aging (1200h).

[0199] Example 21

[0200] The only difference between this embodiment and Embodiment 1 is that the first and second diluents are diluent X3, and the third to sixth diluents are all diluent Y2.

[0201] The aging resistance test results of the anti-corrosion and cleaning nano-coating are as follows: it does not bubble, crack, peel, or powder after aging (1080h).

[0202] Application Example 1

[0203] The anti-corrosion and cleaning nano-coating of Embodiment 1 of this invention has been used continuously for 8 years in the electrical engineering department of China State Railway Group, and the product quality has been fully verified. The anti-corrosion lifespan of the anti-corrosion and cleaning nano-coating has been verified to be 5-8 years, therefore, only 3 anti-corrosion applications are needed during the equipment's lifespan. The verified ratio of material cost to labor cost for construction is approximately 1:3, with the labor cost far exceeding the cost of the coating itself. Compared with existing anti-corrosion coatings and construction processes, in the field of railway equipment maintenance, the application of the anti-corrosion and cleaning nano-coating of this invention significantly reduces railway equipment maintenance costs and substantially reduces the safety risks associated with on-track construction.

[0204] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An anticorrosive and clean-keeping nano-coating, characterized in that, The coating comprises a bottom layer, an intermediate layer and a surface layer arranged from bottom to top in sequence, The raw materials of the bottom layer comprise A component and B component; the mass ratio of the A component and the B component is 8:1; The A component comprises the following raw materials in parts by weight: epoxy resin 30-42 parts, toughening agent 5-12 parts, pigment 25-35 parts, chelating agent 8-15 parts, thixotropic agent 4-8 parts, and first diluent 1-18 parts; the mass of the first diluent is ≤18% of the mass of the A component; The B component comprises the following raw materials in parts by weight: phenolic amine resin 45-60 parts, bottom layer catalyst 2-5 parts, functionality regulator 5-8 parts, and second diluent 30-45 parts; the mass of the second diluent accounts for 30%-45% of the mass of the B component; The raw materials of the intermediate layer comprise C component and D component; the mass ratio of the C component and the D component is 8:1; The C component comprises the following raw materials in parts by weight: hydroxy acrylic acid resin 45-55 parts, anti-aging agent 5-8 parts, pigment 15-25 parts, auxiliary agent 2-6 parts, thixotropic agent 2-3 parts, and third diluent 1-25 parts; the mass of the third diluent is ≤25% of the mass of the C component; The D component comprises the following raw materials in parts by weight: hexamethylene diisocyanate 45-60 parts, intermediate layer catalyst 2-10 parts, and fourth diluent 30-45 parts; the mass of the fourth diluent accounts for 30%-45% of the mass of the D component; The raw materials of the surface layer comprise E component and F component; the mass ratio of the E component and the F component is 3:1; The E component comprises the following raw materials in parts by weight: hydroxy acrylic acid resin 45-60 parts, anti-aging agent 5-8 parts, pigment 0-5 parts, auxiliary agent 2-3 parts, surfactant 6-10 parts, microcrystalline wax 2-5 parts, and fifth diluent 20-30 parts; the mass of the fifth diluent accounts for 20%-30% of the mass of the E component; The F component comprises the following raw materials in parts by weight: hexamethylene diisocyanate 50-60 parts, surface layer catalyst 2-5 parts, and sixth diluent 35-45 parts; the mass of the sixth diluent accounts for 35%-45% of the mass of the F component.

2. A corrosion and cleaning protection nano-coating according to claim 1, characterized in that, The first diluent and the second diluent each independently consist of the following components in percentage by weight: Toluene 50%-70%, butanol 15%-30%, ethylene glycol butyl ether 10%-20%; The third diluent, the fourth diluent, the fifth diluent and the sixth diluent each independently consist of the following components in percentage by weight: dimethylbenzene 40%-60%, anhydrous butyl acetate 30%-40%, cyclohexanone 0-30%.

3. The anticorrosive and clean-keeping nano-coating according to claim 1, characterized in that, The epoxy resin comprises epoxy resin E44 and epoxy resin E51 in a mass ratio of 1:1-5.

4. The anticorrosive and clean-keeping nano-coating according to any one of claims 1-3, characterized in that, The preparation method of the A component comprises the following steps: A1, mix the thixotropic agent with 25%-35% of the mass of the first diluent, stir uniformly and activate to obtain a thixotropic agent prepolymer; A2, mix the epoxy resin and the toughening agent, add the pigment, the chelating agent, the auxiliary agent and the remaining mass of the first diluent, and mix uniformly to obtain a mixture; A3, add the thixotropic agent prepolymer into the mixture, mix uniformly, and obtain the A component.

5. A corrosion and cleaning protection nano-coating according to claim 4, characterized in that, The preparation method of the C component comprises the following steps: C1, add the pigments, additives, anti-aging agents, thixotropic agents, and 25-35% of the third diluent into the hydroxyl acrylic resin, mix uniformly, and obtain the preliminary mixture; C2, add the remaining third diluent into the preliminary mixture, mix uniformly, and obtain the C component.

6. A corrosion and cleaning protection nano-coating according to claim 5, characterized in that, The preparation method of the E component comprises the following steps: E1, mix the surfactant and the fifth diluent according to the mass ratio of 1:1, and obtain the first mixture; E2, add the pigments, additives, anti-aging agents, thixotropic agents, and 25-35% of the fifth diluent into the hydroxyl acrylic resin, mix uniformly, and obtain the second mixture; E3, add the first mixture and the microcrystalline wax into the second mixture, mix uniformly, and obtain the third mixture; E4, add the remaining fifth diluent into the third mixture, mix uniformly, and obtain the E component.

7. The method according to any one of claims 1 to 6, wherein the method is characterized by, The preparation method comprises the following steps: S1, mix and stir the A component and the B component, obtain the bottom layer coating, and spray one layer of the bottom layer coating on the surface of the equipment by using the cross intersection method; S2, mix and stir the C component and the D component, obtain the intermediate layer coating, and spray one layer of the intermediate layer coating on the surface of the bottom layer coating by using the cross intersection method; S3, mix and stir the E component and the F component, obtain the surface layer coating, and spray one layer of the surface layer coating on the surface of the intermediate layer coating by using the cross intersection method, and obtain the anti-corrosion and clean-keeping nano coating.

8. The construction method according to claim 7, characterized in that, The coating film thickness of the bottom layer is 120-180 μm, the coating film thickness of the intermediate layer is 80-100 μm, and the coating film thickness of the surface layer is 30-50 μm.

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