A manufacturing method for anticorrosion paint with excellent adhesion to rusty, low-treatment surfaces

Abstract

This application discloses a method for producing an anticorrosion coating having excellent adhesion to rusted, low-treatment surfaces, which relates to the field of paint chemical industry. The anticorrosion coating comprises Component A and Component B, where Component A comprises an epoxy resin, double-coated hollow glass microbeads, a thixotropic agent, a wetting and dispersing agent, a pigment, barium sulfate, talc, Solvent A, an antifoaming agent, a first silane coupling agent, and an aluminum powder paste, and Component B comprises a curing agent, an accelerator, and Solvent B.

Description

[Technical Field]

[0001] This application relates to the field of paint chemistry industry, and more particularly to an anticorrosion paint having excellent adhesion to rusty, under-treated surfaces and a method for preparing the same. [Background technology]

[0002] Steel structures are widely used as metallic materials in a wide range of fields, including construction, manufacturing, and transportation. They are also a core material in modern shipbuilding, primarily used in the manufacture of ship hull structures, equipment, and components. Steel structures are typically coated with a shop primer or temporary oil before shipping. However, while the corrosion protection period of shop primer or temporary oil is approximately 3 to 6 months, steel structures have a long construction cycle, making the development of internal rust a serious problem. Therefore, rust removal is required for steel structures.

[0003] Among the many rust removal methods, high-pressure water sandblasting generates no dust and is low-cost. Its economical, efficient, and environmentally friendly characteristics have made it a mainstream choice in the rust removal field, and it is widely used, especially on large cruise ships and cargo ships. After rust removal using high-pressure water sandblasting, the surface of a steel structure is exposed to the atmosphere. Humidity and corrosive substances can cause flash rust to develop to varying degrees. Flash rust can be classified into mild flash rust (Class L), moderate flash rust (Class M), and severe flash rust (Class H), with Class H being the most severe. Severe flash rust in Class H indicates severe rust. The appearance of the original steel surface is characterized by a dark reddish-yellow or brown rust layer, which is thick, loosely adhered, uniformly distributed, and continuous. After lightly wiping with a cloth, a clear trace of rust remains on the cloth. H-grade flash rust significantly impairs the adhesion of the paint film, causing it to peel off and blister. Furthermore, rust corrosion weakens the corrosion resistance of metals, shortening their service life and affecting the aesthetics of the surface, thereby reducing the value of the product.

[0004] Chinese Patent CN109370380A discloses a high-solids rust-converting anticorrosive paint and its manufacturing method, focusing primarily on environmentally friendly paints that do not cause environmental pollution. Chinese Patent CN103788829A discloses a low-grade substrate-treated heavy-duty anticorrosion epoxy primer that can be applied to rusty, damp, low-grade substrate-treated steel. Chinese Patent CN103725159A discloses a highly adaptable anticorrosion paint that has good adhesion to hot-dip galvanized steel, rusty hot-dip galvanized steel, rusty steel, and conventional epoxy, acrylic, and fluorocarbon resin coatings, and also has excellent corrosion prevention, weather resistance, and solvent resistance properties. Chinese Patent CN113321987A discloses a highly tolerant epoxy primer for surfaces after water jet rust removal, and its manufacturing method and use, which is suitable for moderate to light flash rust surfaces of steel structures where corrosion inhibitors remain on the surface after water jet rust removal. Although the coatings disclosed in the above patents each have their own advantages, none of them are suitable for H-class flash rust surfaces.

[0005] In the prior art, there have been no reports of flash rust occurring on surfaces that have been high-pressure water sandblasted, and flash rust grading of Class H. The salt fog resistance of conventional low-surface-treatment epoxy primers is only 1,000 to 1,400 hours, which is still far from the high salt fog resistance required for heavy-duty corrosion protection applications in ships and marine construction, which requires more than 5,000 hours. Summary of the Invention [Problem to be solved by the invention]

[0006] To solve the problems of the prior art, the present application provides a method for preparing an anticorrosion coating that has excellent adhesion to rusted, low-treatment surfaces. The anticorrosion coating of the present application that has excellent adhesion to rusted, low-treatment surfaces has excellent adhesion to metal substrate surfaces after treatment methods such as manual rust removal, mechanical rust removal, and rust removal by water sandblasting, has extremely good corrosion prevention properties, and has high tolerance to flash rust on surfaces after rust removal treatment by water sandblasting, making it suitable for H-class flash rust surfaces. [Means for solving the problem]

[0007] One of the objects of the present invention is to provide an anticorrosion coating that has excellent adhesion to rusty, under-treated surfaces.

[0008] According to the anticorrosion coating material having excellent adhesion to rusted, low-treatment surfaces of the present invention, the anticorrosion coating material has the following features: It is prepared from raw materials containing components A and B, Component A includes an epoxy resin, double-coated hollow glass microbeads, a thixotropic agent, a wetting and dispersing agent, a pigment, barium sulfate, talc, solvent A, an antifoaming agent, a first silane coupling agent, and an aluminum powder paste; Component B includes a curing agent, an accelerator, and a solvent B; In the component A, the epoxy resin is used as 100 parts by weight, Epoxy resin 100 parts by weight, Double-coated hollow glass microbeads 100 to 300 parts by weight, 5 to 15 parts by weight of a thixotropic agent, Wetting and dispersing agent 0.5 to 5 parts by weight, 1 to 10 parts by weight of pigment, Barium sulfate 60 to 200 parts by weight, Talc 60 to 200 parts by weight, Solvent A: 60 to 150 parts by weight; 1 to 5 parts by weight of antifoaming agent, 1 to 10 parts by weight of a first silane coupling agent, 40 to 100 parts by weight of aluminum powder paste; In the component B, the curing agent is used as 100 parts by weight, Hardener 100 parts by weight, Accelerator 0.5 to 5 parts by weight, Solvent B: 10 to 50 parts by weight.

[0009] In one preferred embodiment of the present application, In the component A, the epoxy resin is used as 100 parts by weight, Epoxy resin 100 parts by weight, Double-coated hollow glass microbeads 150 to 250 parts by weight, 5 to 13 parts by weight of a thixotropic agent, Wetting and dispersing agent 1.8 to 3 parts by weight, Pigment 3 to 10 parts by weight, Barium sulfate 90 to 120 parts by weight, Talc 120 to 150 parts by weight, Solvent A 100 to 150 parts by weight, 2 to 4 parts by weight of antifoaming agent, 3 to 6 parts by weight of a first silane coupling agent, 40 to 80 parts by weight of aluminum powder paste; In the component B, the curing agent is used as 100 parts by weight, Hardener 100 parts by weight, Accelerator 0.5 to 2 parts by weight, Solvent B: 10 to 30 parts by weight; The weight ratio of the component A to the component B is 100:(10 to 50), and preferably 100:(12 to 45).

[0010] In one preferred embodiment of the present application, The double-coated hollow glass microbeads are obtained by mixing and reacting raw materials including the epoxy resin to be modified, the iron rust capturing filler, the isocyanate prepolymer, the catalyst, and the reaction solvent in a protective gas atmosphere.

[0011] In one preferred embodiment of the present application, The weight ratio of the epoxy resin to be modified, the iron rust capturing filler, and the isocyanate prepolymer is (5-15):(1-5):1, preferably (8-12):(1.5-3.8):1, and / or The amount of the catalyst used is 0.01 wt to 5 wt %, preferably 0.1 wt to 1 wt %, based on the isocyanate prepolymer, and / or The amount of the reaction solvent used is 20 to 40 wt %, preferably 25 to 30 wt %, based on the epoxy resin to be modified, and / or The reaction temperature of the mixing reaction is 80° C. to 100° C., preferably 80° C. to 90° C., and / or the reaction time is 1 to 5 hours, preferably 2 to 3 hours.

[0012] In one preferred embodiment of the present application, The iron rust capturing filler is obtained by immersing hollow glass microbeads in a solution containing tannic acid, a second silane coupling agent, and an immersion solvent, followed by low-temperature freeze-drying; and / or The isocyanate prepolymer is obtained by vacuum dehydrating and cooling a dimer acid polyester polyol, and then prepolymerizing the resulting mixture with an isocyanate in a protective gas atmosphere, and / or The epoxy resin to be modified is at least one of bisphenol A type epoxy resins, preferably at least one of bisphenol A epoxy resin 618, bisphenol A epoxy resin 6101, bisphenol A epoxy resin 601, and bisphenol A epoxy resin 604, and preferably the epoxy equivalent of the epoxy resin to be modified is 150 to 1000, and / or the catalyst is at least one of sulfuric acid, perchloric acid, sodium methoxide, lithium methoxide, potassium eicosylsulfonate, alkali metal hydroxide, triarylphosphine, triphenylphosphine, tin(II) octoate, dibutyltin dilaurate, and iron(III) bromide; and / or The reaction solvent is a mixture of xylene and at least one of butyl acetate, propylene glycol methyl ether acetate, and dipropylene glycol dimethyl ether, and preferably, the mixing weight ratio of the xylene to at least one of butyl acetate, propylene glycol methyl ether acetate, and dipropylene glycol dimethyl ether is (1.5 to 1:1).

[0013] In one preferred embodiment of the present application, the weight ratio of the immersion solvent, tannic acid, second silane coupling agent, and hollow glass microbeads is (0.4-2):(0.1-0.5):(0.1-0.5):1, preferably (0.8-1.6):(0.2-0.4):(0.25-0.4):1; and / or The weight ratio of the isocyanate to the dimer acid polyester polyol is 1:(0.5 to 10), and preferably 1:(0.9 to 6).

[0014] In one preferred embodiment of the present application, The standard median particle size of the hollow glass microbeads is 18 to 60 μm, preferably 30 to 50 μm, and / or The tannic acid is a tannic acid commonly used in the art, which may be chemically pure or an analytical reagent, and / or the second silane coupling agent is at least one of vinyltrimethoxysilane, 3-glycidyloxypropyltrimethoxysilane (e.g., silane coupling agent KH560, silane coupling agent A187), and 3-aminopropyltriethoxysilane (e.g., silane coupling agent KH550); and / or The immersion solvent is a mixture of water and ethanol, and preferably, the weight ratio of water to ethanol is (0.5 to 2):1, more preferably (0.6 to 1.5):1; and / or the isocyanate is at least one of 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, carbodiimide-uretonimine modified 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and polymethylene polyphenyl polyisocyanate; and / or The molecular weight of the dimer acid polyester polyol is 1,000 to 10,000.

[0015] In one preferred embodiment of the present application, The immersion temperature is 10 to 50°C, preferably 20 to 40°C, and / or the immersion time is 1 to 4 hours, preferably 2 to 3 hours, and / or The temperature of the low-temperature freeze-drying is −30° C. to −90° C., preferably −40° C. to −80° C., and / or the time is 1 to 5 hours, preferably 2 to 4 hours, and / or The temperature of the vacuum dehydration is 110 to 150°C, and / or the degree of vacuum is -0.08 Pa to -0.10 Pa, and / or the time is 0.5 hours to 2 hours, and / or The temperature after cooling is 60°C or less, and / or The reaction temperature of the prepolymerization reaction is 80° C. to 100° C., preferably 80° C. to 90° C., and / or the reaction time is 1 to 4 hours, preferably 2 to 3 hours.

[0016] In one preferred embodiment of the present application, The epoxy resin is at least one liquid bisphenol A epoxy resin, preferably at least one of Bisphenol A Epoxy Resin 618, Bisphenol A Epoxy Resin 6101, Bisphenol A Epoxy Resin 601, and Bisphenol A Epoxy Resin 604; and / or The thixotropic agent is at least one of organic bentonite, modified hydrogenated castor oil, polyamide wax powder (e.g., polyamide wax powder ultra, polyamide wax powder 8056, polyamide wax powder OPTIMA), and silica fume, and preferably, the polyamide wax powder is hydrogenated castor oil modified polyamide wax powder (e.g., castor oil modified polyamide wax powder ST), and / or the wetting and dispersing agent is at least one of a polyacrylate solution (e.g., wetting and dispersing agent BYK-S706), a block copolymer containing a basic pigment affinity group (e.g., wetting and dispersing agent BYK-2155), an alkylammonium salt type wetting and dispersing agent of a high molecular weight copolymer (e.g., wetting and dispersing agent BYK-9076), an acrylic dispersing agent (e.g., wetting and dispersing agent BYK-359), an organosilicon surfactant, an acid group-containing copolymer solution (e.g., wetting and dispersing agent Disponer 9250), an alkylammonium salt solution of a polycarboxylic acid (e.g., wetting and dispersing agent BYK-203), and / or the pigment is at least one of carbon black, red iron oxide, yellow iron oxide, titanium white, and phthalocyanine blue; and / or said solvent A being 1-butanol and optionally xylene; and / or The defoaming agent is a defoaming agent commonly used in the art, such as at least one of defoaming agent BYK-530, defoaming agent BYK-085, and defoaming agent BYK-066; and / or the first silane coupling agent is at least one of vinyltrimethoxysilane, 3-glycidyloxypropyltrimethoxysilane (e.g., silane coupling agent KH560, silane coupling agent A187), and 3-aminopropyltriethoxysilane (e.g., silane coupling agent KH550); and / or The aluminum powder paste is a non-leafing aluminum powder paste (e.g., non-leafing aluminum powder paste 2501), and / or The curing agent is at least one of phenolic amide curing agents (e.g., phenolic amide curing agent LITE3040, phenolic amide curing agent LITE3025, phenolic amide curing agent LITE3060), and is preferably a cardanol-modified phenolic amide curing agent. The cardanol in the cardanol-modified phenolic amide curing agent has a long fatty side chain and excellent hydrophobicity, allowing the coating to exhibit excellent water resistance and surface durability, while combining the advantages of polyamide and phenolamine, and having high tolerance to the substrate surface; and / or The accelerator is an epoxy curing accelerator, preferably at least one of triethylenediamine, 2,4,6-tris(dimethylaminomethyl)phenol (accelerator DMP-30), and benzyldimethylamine, more preferably 2,4,6-tris(dimethylaminomethyl)phenol, and / or The solvent B is 1-butanol and optionally xylene, and is preferably a mixture of 1-butanol and xylene, and more preferably, the weight ratio of the 1-butanol to the xylene is (0.3 to 1.5):1.

[0017] A second object of the present invention is to provide a method for producing an anticorrosion coating having excellent adhesion to rusted, poorly treated surfaces according to the first object of the present invention.

[0018] According to the method for producing an anticorrosion coating having excellent adhesion to a rusted, low-treatment surface of the present invention, the method comprises the steps of: The method includes the steps of: mixing component A in the amount used to obtain component A; mixing component B in the amount used to obtain component B; and mixing component A and component B to obtain the anticorrosion coating.

[0019] Of these, the following solutions can be specifically adopted as a method for preparing component A.

[0020] (1) Preparation of double-coated hollow glass microbeads Step 1: Synthesis of iron rust capture filler (surface modification of hollow glass microbeads): The surface of hollow glass microbeads is chemically modified using a second silane coupling agent and tannic acid, and the hollow glass microbeads are immersed in a solution containing the second silane coupling agent, tannic acid, and an immersion solvent at 10 to 50°C for 1 to 4 hours, and then freeze-dried to remove water and ethanol. Step 2: Synthesis of isocyanate prepolymer: Dimer acid polyester polyol is vacuum dehydrated at 110-150°C, and the dehydrated dimer acid polyester polyol and isocyanate are added to a reactor in a protective gas atmosphere (nitrogen gas). The reaction temperature is maintained at 80-100°C and the reaction is carried out for 1-4 hours. The isocyanate content is measured, and the material is discharged. Step 3: Take another reactor, vacuum dehydrate the epoxy resin to be modified, add a catalyst while stirring, gradually add the above synthesized isocyanate prepolymer, gradually increase the temperature to 80-100°C to react, then add the above synthesized iron rust capture filler, add a reaction solvent and stir evenly, increase the temperature to 80-100°C to react, measure the epoxy value, cool to room temperature, and discharge the material.

[0021] (2) Add the epoxy resin, double-coated hollow glass microbeads, and thixotropic agent to the paint mixing tank and disperse at high speed for 5 to 10 minutes to thoroughly and uniformly disperse the thixotropic agent. Add the wetting and dispersing agent while dispersing at low speed and stir evenly.

[0022] (3) While dispersing at a low speed, add 80% of solvent A, pigment, talc, and barium sulfate in that order, and stir at high speed for 30 to 50 minutes at 50 to 70°C until the fineness is 80 μm or less. Add the remaining solvent A, antifoaming agent, first silane coupling agent, and aluminum powder paste, and stir uniformly, then discharge the material.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] First, the double-coated hollow glass microbeads employed in this application incorporate an isocyanate prepolymer and a rust-trapping filler (modified hollow glass microbeads) into the epoxy resin molecules to be modified (modified hollow glass microbeads), improving the compatibility between the hollow glass microbeads and the epoxy resin to be modified and allowing the rust-trapping filler (modified hollow glass microbeads) to be uniformly dispersed in the coating solution. As shown in Figures 1-3, 1. In the initial stage of coating, i.e., before curing, when the coating comes into contact with an untreated surface, the tannic acid on the surface of the hollow glass microbeads can adsorb and react with rust on the substrate surface. 2. During curing, the hollow glass microbeads, due to their low specific gravity, adsorb the reactants and gradually detach from the substrate surface, floating to the middle or upper layer of the coating solution. 3. After curing, the rust adsorbed by the hollow glass microbeads can be incorporated into the epoxy resin coating as a filler without affecting the adhesion of the coating to the substrate, ensuring high adhesion. The anticorrosion coating of the present invention not only improves adhesion to the H-class flash-last surface, but also utilizes the low specific gravity of the hollow glass microbeads themselves to achieve the requirement for a lightweight coating film.

[0025] Second, the isocyanate prepolymer used in this application, which is obtained by prepolymerizing isocyanate and dimer acid polyester polyol, enhances the degree of cross-linking and toughness of the system's molecules, improves the reactivity, impact resistance, adhesive strength and peel strength of the epoxy resin, and improves adhesion to the substrate surface.

[0026] Third, the anticorrosion coating provided by the present application, which has excellent adhesion to rusted, low-treatment surfaces, solves the technical problem of the prior art, which is that mechanical rust removal, manual rust removal, and rust removal by water sandblasting cannot be simultaneously used. For surfaces treated by water sandblasting with different flash rust grades, especially for high-grade flash rust surfaces, the anticorrosion coating has high adhesion and excellent salt fog resistance. It is suitable for anticorrosion coating in fields such as ships, bridges, and steel structures, and is particularly suitable for direct application to flash rusted surfaces, simplifying the surface treatment process and improving application efficiency and cost-effectiveness. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a schematic diagram of the curing process for the anticorrosion coating of the present application, which has excellent adhesion to rusted, under-treated surfaces. [Figure 2] 1 is a microscopic schematic diagram of the curing process for the anticorrosion coating material according to the present application, which has excellent adhesion to rusted, low-treatment surfaces, before curing. FIG. [Figure 3] 1 is a microscopic schematic diagram showing the curing process of the anticorrosion coating having excellent adhesion to a rusted, low-treatment surface according to the present invention. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0028] The present application will be specifically described below with reference to specific figures and examples. It should be noted that the following examples are for further explanation of the present application and should not be understood as limiting the scope of protection of the present application, and any non-essential improvements and adjustments made to the present application by those skilled in the art based on the contents of the present application will still fall within the scope of protection of the present application.

[0029] The raw materials used in the examples and comparative examples of this application are all common commercially available raw materials.

[0030] The test methods employed in the examples and comparative examples of the present application are as follows.

[0031] Density: Tested according to Chinese standard GB / T 6750 Salt fog resistance (5000h): Tested according to Chinese standard GB / T1771 Resistance to cathodic ablation (6 months, distance from artificial hole to ablation area): Tested according to Chinese standard GB / T7790 Adhesion: Tested according to Chinese standard GB / T 5210.

[0032] Example 1 Preparation of Component A: (1) Preparation of double-coated hollow glass microbeads Step 1: Preparation of iron rust capture filler (surface modification of hollow glass microbeads): 20 parts by weight of tannic acid and 25 parts by weight of silane coupling agent KH560 were added to 80 parts by weight of a mixed solution of water and ethanol in a weight ratio of 1:1, and stirred uniformly. 100 parts by weight of hollow glass microbeads with a standard median particle size of 30 μm and the above mixed liquid were added to a powder mixer, mixed thoroughly and uniformly, immersed at 20°C for 3 hours, and then freeze-dried to remove the water and ethanol, thereby obtaining iron rust capture filler (modified hollow glass microbeads).

[0033] Step 2: Synthesis of isocyanate prepolymer: 288 parts by weight of dimer acid polyester polyol (functionality 2, molecular weight 1000) is vacuum dehydrated at 120°C for 2 hours, cooled to 60°C, and 100 parts by weight of 2,6-toluene diisocyanate is added while stirring. The mixture is stirred thoroughly and uniformly, gradually heated to 80°C, and kept at this temperature for 2 hours. The isocyanate content is measured, and the resulting product is an isocyanate prepolymer.

[0034] Step 3: Take out another reactor and add 8 parts by weight of bisphenol A epoxy resin 601, 1 part by weight of xylene, and 1 part by weight of dipropylene glycol dimethyl ether. Heat to 60°C and stir for 30 minutes until fully dissolved. Add 1 part by weight of isocyanate prepolymer and stir for 15 minutes until thoroughly mixed. While stirring, add 1 wt% stannous octoate relative to the isocyanate prepolymer. Gradually increase the temperature to 90°C and maintain for 2.5 hours. While stirring, add 1.5 parts by weight of iron rust capture filler (modified hollow glass microbeads). Maintain the temperature at 90°C for 1 hour. Measure the epoxy value. The resulting product is double-coated hollow glass microbeads.

[0035] (2) Component A was obtained by high-speed dispersion of bisphenol A epoxy resin 618, double-coated hollow glass microbeads, barium sulfate, talc, carbon black, titanium white, polyamide wax powder ultra, wetting and dispersing agent BYK-359, antifoaming agent BYK-530, silane coupling agent KH560, xylene, 1-butanol, and non-leafing aluminum powder paste 2501 in the blending ratios shown in Table 1 below.

[0036] Preparation of Component B: Phenolic amide curing agent LITE3040, accelerator DMP-30, xylene, and 1-butanol were added to a paint manufacturing tank in the blending ratios shown in Table 1 below, and the mixture was stirred at high speed for 30 minutes using a high-speed shear disperser to obtain component B.

[0037] The weight ratio of component A to component B was 100:14. [Table 1]

[0038] Example 2 Preparation of Component A: (1) Preparation of double-coated hollow glass microbeads Step 1: Preparation of iron rust capture filler (surface modification of hollow glass microbeads): 20 parts by weight of tannic acid and 40 parts by weight of silane coupling agent KH560 were added to 100 parts by weight of a mixed solution of water and ethanol in a weight ratio of 1:1, and stirred uniformly. 100 parts by weight of hollow glass microbeads with a standard median particle size of 50 μm and the above mixed liquid were added to a powder mixer, mixed thoroughly and uniformly, immersed at 40°C for 3 hours, and then freeze-dried to remove the water and ethanol, thereby obtaining iron rust capture filler (modified hollow glass microbeads).

[0039] Step 2: Synthesis of isocyanate prepolymer: 600 parts by weight of dimer acid polyester polyol (functionality 2, molecular weight 2000) is vacuum dehydrated at 120°C for 2 hours, cooled to 60°C, and 100 parts by weight of 2,6-toluene diisocyanate is added while stirring. The mixture is stirred thoroughly and uniformly, gradually heated to 80°C, and kept at this temperature for 2 hours. The isocyanate content is measured, and the resulting product is an isocyanate prepolymer.

[0040] Step 3: Take out another reactor and take out 8 parts by weight of bisphenol A epoxy resin 6101, 1 part by weight of xylene, and 1 part by weight of dipropylene glycol dimethyl ether. Add 1 part by weight of isocyanate prepolymer and stir for 15 minutes until uniform. While stirring, add 0.1 wt% dibutyltin dilaurate relative to the isocyanate prepolymer. Gradually increase the temperature to 90°C and maintain for 2.5 hours. While stirring, add 1.5 parts by weight of iron rust capture filler (modified hollow glass microbeads). Maintain the temperature at 90°C for 1 hour. Measure the epoxy value. The resulting product is double-coated hollow glass microbeads.

[0041] (2) Component A was obtained by high-speed dispersion of bisphenol A epoxy resin 618, double-coated hollow glass microbeads, barium sulfate, talc, red iron oxide, polyamide wax powder ultra, wetting and dispersing agent BYK-2155, antifoaming agent BYK-530, silane coupling agent KH560, xylene, 1-butanol, and non-leafing aluminum powder paste 2501 in the blending ratios shown in Table 2 below.

[0042] Preparation of Component B: Phenolic amide curing agent LITE3040, accelerator DMP-30, xylene, and 1-butanol were added to a paint manufacturing tank in the blending ratios shown in Table 2 below, and the mixture was stirred at high speed for 30 minutes using a high-speed shear disperser to obtain component B.

[0043] The weight ratio of component A to component B was 100:16. [Table 2]

[0044] Example 3 Preparation of Component A: (1) Preparation of double-coated hollow glass microbeads Step 1: Preparation of iron rust capture filler (surface modification of hollow glass microbeads): 40 parts by weight of tannic acid and 25 parts by weight of silane coupling agent KH560 were added to 160 parts by weight of a mixed solution of water and ethanol in a 1:1 weight ratio, and stirred uniformly. 100 parts by weight of hollow glass microbeads with a standard median particle size of 40 μm and the mixed liquid were added to a powder mixer, mixed thoroughly and uniformly, immersed at 40°C for 2 hours, and then freeze-dried to remove the water and ethanol, thereby obtaining iron rust capture filler (modified hollow glass microbeads).

[0045] Step 2: Synthesis of isocyanate prepolymer: 90 parts by weight of dimer acid polyester polyol (functionality 2, molecular weight 2000) is vacuum dehydrated at 120°C for 2 hours, cooled to 60°C, and 100 parts by weight of 2,4'-diphenylmethane diisocyanate is added while stirring. The mixture is stirred thoroughly and uniformly, gradually heated to 80°C, and kept at this temperature for 2 hours. The isocyanate content is measured, and the resulting product is an isocyanate prepolymer.

[0046] Step 3: Take out another reactor and add 12 parts by weight of bisphenol A epoxy resin 6101, 1.8 parts by weight of xylene, and 1.2 parts by weight of dipropylene glycol dimethyl ether. Heat to 60°C and stir for 30 minutes until fully dissolved. Add 1 part by weight of isocyanate prepolymer and stir thoroughly until uniform. While stirring, add 0.1 wt% dibutyltin dilaurate relative to the isocyanate prepolymer. Gradually increase the temperature to 90°C and maintain for 2.5 hours. While stirring, add 3.8 parts by weight of iron rust capture filler (modified hollow glass microbeads). Maintain the temperature at 90°C for 1 hour. Measure the epoxy value. The resulting product is double-coated hollow glass microbeads.

[0047] (2) Component A was obtained by high-speed dispersion of bisphenol A epoxy resin 6101, double-coated hollow glass microbeads, talc, barium sulfate, red iron oxide, polyamide wax powder 8056, wetting and dispersing agent BYK-203, antifoaming agent BYK-066, silane coupling agent KH560, xylene, 1-butanol, and non-leafing aluminum powder paste 2501 in the blending ratios shown in Table 3 below.

[0048] Preparation of Component B: Phenolic amide curing agent LITE3025, accelerator DMP-30, xylene, and 1-butanol were added to a paint manufacturing tank in the blending ratios shown in Table 3 below, and the mixture was stirred at high speed for 30 minutes using a high-speed shear disperser to obtain component B.

[0049] The weight ratio of component A to component B was 100:19. [Table 3]

[0050] Example 4 Preparation of Component A: (1) The double-coated hollow glass microbeads were prepared in the same manner as in Example 1.

[0051] (2) Component A was obtained by high-speed dispersion of bisphenol A epoxy resin 6101, double-coated hollow glass microbeads, talc, barium sulfate, titanium white, carbon black, castor oil-modified polyamide wax powder ST, wetting and dispersing agent BYK-203, antifoaming agent BYK-066, silane coupling agent KH560, xylene, 1-butanol, and non-leafing aluminum powder paste 2501 in the blending ratios shown in Table 4 below.

[0052] Preparation of Component B: Phenolic amide curing agent LITE3060, phenolic amide curing agent LITE3040, accelerator DMP-30, xylene, and 1-butanol were added to a paint manufacturing tank in the blending ratios shown in Table 4 below, and the mixture was stirred at high speed for 30 minutes using a high-speed shear disperser to obtain component B.

[0053] The weight ratio of component A to component B was 100:12. [Table 4]

[0054] Example 5 Preparation of Component A: (1) The double-coated hollow glass microbeads were prepared in the same manner as in Example 3.

[0055] (2) Component A was obtained by high-speed dispersion of bisphenol A epoxy resin 618, double-coated hollow glass microbeads, barium sulfate, talc, red iron oxide, polyamide wax powder OPTIMA, wetting and dispersing agent BYK-9076, antifoaming agent BYK-085, silane coupling agent A187, xylene, 1-butanol, and non-leafing aluminum powder paste 2501 in the blending ratios shown in Table 5 below.

[0056] Preparation of Component B: Phenolic amide curing agent LITE3005, accelerator DMP-30, xylene, and 1-butanol were added to a paint manufacturing tank in the blending ratios shown in Table 5 below, and the mixture was stirred at high speed for 30 minutes using a high-speed shear disperser to obtain component B.

[0057] The weight ratio of component A to component B was 100:44. [Table 5]

[0058] Comparative Example 1 Compared with Example 1, Comparative Example 1 uses the same amount of epoxy resin 601 instead of the double-coated hollow glass microbeads, and the specific preparation method is as follows:

[0059] Preparation of Component A: Component A was obtained by high-speed dispersion of bisphenol A epoxy resin 618, bisphenol A epoxy resin 601, barium sulfate, talc, carbon black, titanium white, polyamide wax powder ultra, wetting and dispersing agent BYK-359, antifoaming agent BYK-530, silane coupling agent KH560, xylene, 1-butanol, and non-leafing aluminum powder paste 2501 in the blending ratios shown in Table 6 below.

[0060] Preparation of Component B: Phenolic amide curing agent LITE3040, accelerator DMP-30, xylene, and 1-butanol were added to a paint manufacturing tank in the blending ratios shown in Table 6 below, and the mixture was stirred at high speed for 30 minutes using a high-speed shear disperser to obtain component B.

[0061] The weight ratio of component A to component B was 100:17.3. [Table 6]

[0062] Specimen preparation: 1. Substrate treatment: Thoroughly remove grease and oil with a suitable detergent, and wash (high-pressure) with fresh water to remove salt and other contaminants. Sandblast to a surface roughness of Sa2.5 (ISO 8501-1:2007), equivalent to Rugotest No. 3 N9a to N10, Keane-Tator Comparison Plate 2.0 (sandblasted / shot-peened), or ISO Comparison Plate fine and medium roughness (sandblasted). Or waterjet to Wa2 to Wa2.5 (exposed) / minimum Wa2.5 (immersed) (ISO 8501-1:2007). Prior to application, grade to flash-last according to standard ISO 8501-4:2006.

[0063] After water jetting, the steel surface will have a visible flash rust appearance. Refer to Chinese standard GB / T8923.4-2013 (same as ISO 8501-4:2006). Depending on the degree of flash rust, flash rust is divided into three grades: L, M, and H.

[0064] 2. Preparation of coating film Examples 1 to 5 and Comparative Example 1 were mixed in the weight ratio of component A and component B as described above, and thoroughly stirred. The density of the paint was tested in a constant temperature and humidity paint spray booth. A high-pressure airless spray machine was used to spray the coating. The coating film preparation requirements (including thickness) were in accordance with the provisions of the corresponding test standards, and the related performance of the coating film was tested.

[0065] (1) The density test data are shown in Table 7 below. [Table 7]

[0066] (2) The data of the salt fog resistance (5000h) test is shown in Table 8 below. [Table 8]

[0067] (3) The data for the cathodic disbondment resistance (6 months) test are shown in Table 9 below. [Table 9]

[0068] (4) The adhesion test data are shown in Table 10 below. [Table 10]

[0069] As can be seen from the test data of Examples 1-5 and Comparative Example 1, the addition of double-coated hollow glass microbeads significantly reduced the density of the coating. The density of the anticorrosion coating prepared according to the present invention was 84.5% to 86.5% of that of Comparative Example 1. By incorporating an isocyanate prepolymer with a dimer acid structure and modified glass microbeads into the epoxy resin molecules of the double-coated hollow glass microbeads in the present examples, the solvent resistance of the coating film, particularly the salt fog resistance and cathodic peeling resistance of M- and H-grade steel structure surfaces after water sandblasting, was significantly improved. Salt fog resistance was maintained for over 5,000 hours, with no blistering, peeling, or rusting of the coating film. The distance from the artificial hole to the peeled area after 6 months of cathodic peeling was significantly reduced, from 19 mm in Comparative Example 1 to less than 8 mm. Adhesion strength was significantly improved, from 3.5 MPa in Comparative Example 1 to more than 6 MPa.

[0070] The anticorrosion coatings according to Examples 1 to 5 of the present application have low density, effectively reducing the weight of the coating film, and have excellent adhesion to surfaces after treatment methods such as manual rust removal, mechanical rust removal, and rust removal by water sandblasting. They also have excellent salt fog resistance and cathodic peeling resistance, and are highly tolerant to flash rust on surfaces after rust removal treatment by water sandblasting, making them suitable for H-class flash rust surfaces.

Claims

1. A method for producing an anticorrosion coating having excellent adhesion to a rusted, low-treatment surface, comprising: The anticorrosion coating material is obtained by mixing raw materials consisting of component A and component B, Component A includes an epoxy resin, double-coated hollow glass microbeads, a thixotropic agent, a wetting and dispersing agent, a pigment, barium sulfate, talc, solvent A, an antifoaming agent, a first silane coupling agent, and an aluminum powder paste; Component B includes a curing agent, an accelerator, and a solvent B; In the component A, the epoxy resin is 100 parts by weight of epoxy resin, Double-coated hollow glass microbeads 100 to 300 parts by weight, Thixotropic agent: 5 to 15 parts by weight, Wetting and dispersing agent 0.5 to 5 parts by weight, Pigment 1 to 10 parts by weight, Barium sulfate 60 to 200 parts by weight, Talc 60 to 200 parts by weight, Solvent A: 60 to 150 parts by weight, Antifoaming agent 1 to 5 parts by weight, 1 to 10 parts by weight of a first silane coupling agent, 40 to 100 parts by weight of aluminum powder paste; In the component B, the curing agent is used as 100 parts by weight, Curing agent 100 parts by weight, Accelerator 0.5 to 5 parts by weight, Solvent B: 10 to 50 parts by weight; A method for producing an anticorrosion paint, comprising:

2. In the component A, the epoxy resin is 100 parts by weight of epoxy resin, Double-coated hollow glass microbeads 150 to 250 parts by weight, Thixotropic agent: 5 to 13 parts by weight, Wetting and dispersing agent 1.8 to 3 parts by weight, Pigment 3 to 10 parts by weight, Barium sulfate 90 to 120 parts by weight, Talc 120 to 150 parts by weight, Solvent A 100 to 150 parts by weight, Antifoaming agent 2 to 4 parts by weight, 3 to 6 parts by weight of a first silane coupling agent, 40 to 80 parts by weight of aluminum powder paste; In the component B, the curing agent is used as 100 parts by weight, Curing agent 100 parts by weight, Accelerator 0.5 to 2 parts by weight, Solvent B: 10 to 30 parts by weight; The weight ratio of the component A to the component B is 100:(10 to 50).

2. The method for producing the anticorrosion coating material according to claim 1.

3. The double-coated hollow glass microbeads are obtained by mixing and reacting raw materials including a target epoxy resin, an iron rust capture filler, an isocyanate prepolymer, a catalyst, and a reaction solvent in a protective gas atmosphere.

2. The method for producing the anticorrosion coating material according to claim 1.

4. the weight ratio of the epoxy resin to be modified, the iron rust capturing filler, and the isocyanate prepolymer is (5-15):(1-5):1; The amount of the catalyst used is 0.01 wt% to 5 wt% based on the isocyanate prepolymer, The amount of the reaction solvent used is 20 to 40 wt % based on the epoxy resin to be modified, The reaction temperature of the mixing reaction is 80°C to 100°C, and the reaction time is 1 to 5 hours. The method for producing the anticorrosion coating material according to claim 3 .

5. The iron rust capturing filler is obtained by immersing hollow glass microbeads in a solution containing tannic acid, a second silane coupling agent, and an immersion solvent, and then freeze-drying the beads at a low temperature; The isocyanate prepolymer is obtained by vacuum dehydrating a dimer acid polyester polyol, cooling the dehydrated dimer acid polyester polyol, and then subjecting the dehydrated dimer acid polyester polyol to a prepolymerization reaction with an isocyanate in a protective gas atmosphere. The epoxy resin to be modified is at least one kind of bisphenol A type epoxy resin, and the epoxy equivalent of the epoxy resin to be modified is 150 to 1000; the catalyst is at least one of sulfuric acid, perchloric acid, sodium methoxide, lithium methoxide, potassium eicosylsulfonate, alkali metal hydroxide, triarylphosphine, triphenylphosphine, tin(II) octoate, dibutyltin dilaurate, and iron(III) bromide; the reaction solvent is a mixture of xylene and at least one of butyl acetate, propylene glycol methyl ether acetate, and dipropylene glycol dimethyl ether, and the mixing weight ratio of the xylene to the at least one of butyl acetate, propylene glycol methyl ether acetate, and dipropylene glycol dimethyl ether is (1.5 to 1):1; The method for producing the anticorrosion coating material according to claim 3 .

6. the weight ratio of the tannic acid, the second silane coupling agent, and the hollow glass microbeads is (0.1-0.5):(0.1-0.5):1; the weight ratio of the immersion solvent, tannic acid, second silane coupling agent, and hollow glass microbeads is (0.4-2):(0.1-0.5):(0.1-0.5):1; The weight ratio of the isocyanate to the dimer acid polyester polyol is 1:(0.5 to 10). The method for producing the anticorrosion coating material according to claim 5 .

7. The standard median particle size of the hollow glass microbeads is 18 to 60 μm; the second silane coupling agent is at least one of vinyltrimethoxysilane, 3-glycidyloxypropyltrimethoxysilane, and 3-aminopropyltriethoxysilane; the immersion solvent is a mixture of water and ethanol, and the weight ratio of the water to the ethanol is (0.5 to 2):1; the isocyanate is at least one of 2,6-toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, carbodiimide-uretonimine modified 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, and polymethylene polyphenyl polyisocyanate; The molecular weight of the dimer acid polyester polyol is 1,000 to 10,000. The method for producing the anticorrosion coating material according to claim 5 .

8. The immersion temperature is 10 to 50°C, and the immersion time is 1 to 4 hours. The low-temperature freeze-drying temperature is −30° C. to −90° C., and the time is 1 to 5 hours. The vacuum dehydration temperature is 110 to 150°C, the vacuum degree is -0.08 Pa to -0.10 Pa, and the time is 0.5 hours to 2 hours. The temperature after cooling is 60°C or less, The reaction temperature of the prepolymerization reaction is 80°C to 100°C, and the reaction time is 1 to 4 hours. The method for producing the anticorrosion coating material according to claim 5 .

9. The epoxy resin is at least one liquid bisphenol A epoxy resin, the thixotropic agent is at least one of organic bentonite, modified hydrogenated castor oil, polyamide wax powder, and silica fume; The moistening and dispersing agent is at least one of a polyacrylate solution, a block copolymer containing a base pigment affinity group, an alkylammonium salt type moistening and dispersing agent of a high molecular weight copolymer, an acrylic dispersant, an organosilicon surfactant, an acid group-containing copolymer solution, and an alkylammonium salt solution of a polycarboxylic acid, the pigment is at least one of carbon black, red iron oxide, yellow iron oxide, titanium white, and phthalocyanine blue; the solvent A is a mixture of 1-butanol and xylene, and the weight ratio of the 1-butanol to the xylene is (0.1 to 1):1; the first silane coupling agent is at least one of vinyltrimethoxysilane, 3-glycidyloxypropyltrimethoxysilane, and 3-aminopropyltriethoxysilane; the aluminum powder paste is a non-leafing aluminum powder paste, the curing agent is a cardanol-modified phenolic amide curing agent; the accelerator is at least one of triethylenediamine, 2,4,6-tris(dimethylaminomethyl)phenol, and benzyldimethylamine; The solvent B is a mixture of 1-butanol and xylene, and the weight ratio of the 1-butanol to the xylene is (0.3 to 1.5):

1.

2. The method for producing the anticorrosion coating material according to claim 1.

10. The component A is obtained by the following steps (1) to (3): (1) Preparation of double-coated hollow glass microbeads Synthesis of iron rust capture filler (surface modification of hollow glass microbeads): Step 1: chemically modifying the surface of hollow glass microbeads with a second silane coupling agent and tannic acid, immersing the hollow glass microbeads in a solution containing the second silane coupling agent, tannic acid, and an immersion solvent at 10 to 50°C for 1 to 4 hours, and then freeze-drying to remove water and ethanol; Step 2: synthesizing isocyanate prepolymer: dehydrating dimer acid polyester polyol under vacuum at 110-150°C, adding the dehydrated dimer acid polyester polyol and isocyanate to a reactor in a protective gas atmosphere (nitrogen gas), maintaining the reaction temperature at 80-100°C, reacting for 1-4 hours, measuring the isocyanate content, and discharging the material; and step 3, in which another reaction vessel is used, the epoxy resin to be modified is vacuum dehydrated, a catalyst is added while stirring, the synthesized isocyanate prepolymer is gradually added, the temperature is gradually raised to 80-100°C to react, the synthesized iron rust capture filler is added, a reaction solvent is added and stirred uniformly, the temperature is raised to 80-100°C to react, the epoxy value is measured, the material is cooled to room temperature, and the material is discharged. (2) Add the epoxy resin, double-coated hollow glass microbeads, and thixotropic agent to the paint mixing tank, disperse at high speed for 5 to 10 minutes, thoroughly and uniformly disperse the thixotropic agent, add the wetting and dispersing agent while dispersing at low speed, and stir uniformly; (3) While dispersing at a low speed, add 80% of the solvent A, pigment, talc, and barium sulfate in order, and stir at high speed for 30 to 50 minutes at 50 to 70°C until the fineness becomes 80 μm or less. Then, add the remaining solvent A, antifoaming agent, first silane coupling agent, and aluminum powder paste and stir uniformly, and discharge the material.

2. The method for producing the anticorrosion coating material according to claim 1.

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