Zinc powder composite anticorrosive paint and preparation method thereof

Abstract

The invention discloses a zinc powder composite anticorrosive coating and a preparation method thereof, and relates to the technical field of zinc powder composite anticorrosive coatings. The coating is composed of a component A and a component B. The component A is prepared from the following raw materials in parts by mass: 30-35 parts of epoxy resin, 8-12 parts of a toughening diluent, 0.8-1.5 parts of carbon nanotubes, 7-10 parts of glass flakes, 20-25 parts of zinc powder, 8-12 parts of pigments and fillers, 1-1.5 parts of a surface modifier, 3-4 parts of an auxiliary agent and 10-13 parts of a solvent. The component B is prepared from the following raw materials in parts by mass: 10-14 parts of a curing agent and 1-2 parts of an adhesion promoter. Compared with an epoxy zinc-rich coating, the zinc powder composite anticorrosive coating provided by the invention has better adhesive force, wear resistance, impact resistance and salt fog resistance, and is simple in preparation process and suitable for large-scale popularization and application.

Description

Technical Field

[0001] The invention relates to the technical field of zinc powder composite anti-corrosion coatings, and in particular to a zinc powder composite anti-corrosion coating and a preparation method thereof. Background Art

[0002] In the existing technology, epoxy zinc-rich primer occupies a pivotal position in my country's anti-corrosion coating market. Due to its excellent anti-corrosion performance, epoxy zinc-rich primer is widely used in anti-corrosion coating of steel facilities and equipment, especially in heavy anti-corrosion fields such as chemical industry, construction, offshore platforms, ships, bridges, etc. The anti-corrosion mechanism of epoxy zinc-rich primer mainly depends on the zinc powder therein. The zinc powder protects the steel substrate in a corrosive environment by means of sacrificial anodes, and the zinc salt protective film formed can also prevent the invasion of corrosive media;

[0003] The high content of zinc powder in epoxy zinc-rich primer also brings a series of problems. First of all, although the high content of zinc powder provides a strong cathodic protection, it also means that only about 1 / 3 of the zinc powder connected to the steel surface can participate in the cathodic protection, while about 2 / 3 of the isolated zinc powder is inactive. When corrosion occurs, the active zinc powder is gradually oxidized into an insulating zinc salt, resulting in the destruction of the conductive path and the failure of cathodic protection. In addition, the use of a large amount of zinc powder reduces the film-forming material and the freely adjustable component ratio in the formula, resulting in the brittleness and poor toughness of the paint film, which is prone to failure phenomena such as paint film cracking, stress corrosion, and weld corrosion. At the same time, the use of a large amount of zinc powder also leads to the deterioration of the density and adhesion of the paint film, making the coating film prone to blistering, shedding, rusting, etc. In addition, the reserves of zinc resources on the earth are limited, and half of the total consumption is used for metal corrosion protection. According to statistics from the United States Geological Survey, as of 2019, the world's zinc resources are about 1.9 billion tons, zinc reserves (metal content) are about 250 million tons, and zinc consumption is about 13.76 million tons. The world's zinc ore may only be enough for 16 years. In China, the zinc ore reserves in 2022 will be 46.0786 million tons, and the mineral reserves will increase slightly compared with the previous year. However, the demand for zinc continues to expand, and domestic ore is still in short supply;

[0004] In order to save resources and reduce energy consumption, in recent years, the research on technologies to reduce the amount of zinc powder and replace zinc powder by adding nanomaterials, flaky materials, etc. has become increasingly extensive. The development of these technologies is expected to break through the limitations of existing technologies, change the existing anti-corrosion market competition landscape, and bring new development directions for the application of epoxy zinc-rich primers. At the same time, this is also in line with the trend of global sustainable development, reducing dependence on limited resources, reducing environmental impact, and bringing greener and more efficient solutions to the anti-corrosion coatings industry. Summary of the invention

[0005] The purpose of the present invention is to solve the shortcomings of the prior art and to propose a zinc powder composite anti-corrosion coating and a preparation method thereof.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] A zinc powder composite anti-corrosion coating, the coating is composed of component A and component B, and the component A contains the following raw materials in parts by weight:

[0008] Epoxy resin: 30-35 parts by mass, epoxy equivalent weight 400-600 g / eq;

[0009] Toughening diluent: 8-12 parts by mass, viscosity 30-1200mPa·s (25°C);

[0010] Carbon nanotubes: 0.8-1.5 parts by weight, at least one of hydroxylated carbon nanotubes and carboxylated carbon nanotubes, with a hydroxyl or carboxyl content of 1-4 wt% and a length of 10-50 μm;

[0011] Glass flakes: 7-10 parts by mass, 300-400 mesh;

[0012] Zinc powder: 20-25 parts by mass, mesh size is 500-1000 mesh;

[0013] Pigment and filler: 8-12 parts by weight, at least one of titanium dioxide, barium sulfate and talc;

[0014] Surface modifier: 1-1.5 parts by mass, selected from at least one of 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropylmethyldimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane;

[0015] Additives: 3-4 parts by mass, at least one of a dispersant, a thickener, a defoamer, and a leveling agent;

[0016] Solvent: 10-13 parts by mass, at least one of dibutyl ether, xylene, and n-butanol;

[0017] The second component comprises the following raw materials in parts by weight:

[0018] Curing agent: 10-14 parts by weight, at least one of phenolic amide curing agent, polyamide curing agent, and phenolic amine curing agent;

[0019] Adhesion promoter: 1-2 parts by mass, at least one selected from 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane, and 3-aminopropyltriethoxysilane.

[0020] Preferably, the epoxy resin in component A contains epoxy groups, and the curing agent in component B contains active hydrogen atoms. When the two are mixed, the epoxy groups and the active hydrogen atoms in the curing agent undergo a ring-opening addition reaction to form a three-dimensional network structure to form a resin matrix of the anti-corrosion coating.

[0021] Furthermore: the surface modifier contains epoxy and siloxy groups, wherein the siloxy groups can react with hydroxyl and carboxyl groups on the surface of hydroxylated carbon nanotubes (mainly containing hydroxyl groups on the surface), carboxylated carbon nanotubes (mainly containing carboxyl groups on the surface), and glass flakes (mainly containing hydroxyl groups on the surface) to form covalent bonds.

[0022] Further: the epoxy group has affinity with the epoxy resin and reacts with the curing agent in component B to form a covalent bond.

[0023] As a preferred solution of the present invention, the solvent modifies the liquid matrix of carbon nanotubes and glass flakes.

[0024] A method for preparing a zinc powder composite anti-corrosion coating comprises the following steps:

[0025] S1: Add toughening diluent, dispersant and carbon nanotubes to the solvent in sequence, treat under ultrasonic frequency, then add glass flakes and surface modifier, and stir to obtain modified carbon nanotube / glass flake mixed solution;

[0026] S2: adding epoxy resin and pigments and fillers to the mixed solution obtained in step S1, stirring, and then sequentially adding zinc powder, thickener, leveling agent, and defoamer, and continuing to stir to obtain component A;

[0027] S3: adding the adhesion promoter to the curing agent and stirring to obtain component B;

[0028] S4: Mix the component A obtained in step S2 and the component B obtained in step S3, and stir to obtain a zinc powder composite anti-corrosion coating.

[0029] As a further solution of the present invention: in step S1, the ultrasonic frequency is 40 kHz, the treatment time is 20-45 minutes, the stirring speed is 800-1200 rpm, and the stirring time is 30-60 minutes.

[0030] On the basis of the above scheme: in step S2, the stirring speed is 1200-1500 rpm, and the stirring time is 50-100 minutes.

[0031] On the basis of the above scheme: in step S3, the stirring speed is 1500-2000 rpm, and the stirring time is 5-10 minutes.

[0032] On the basis of the above scheme: in step S4, the stirring speed is 1100-1500 rpm, and the stirring time is 3-5 minutes.

[0033] The beneficial effects of the present invention are:

[0034] 1. A zinc powder composite anti-corrosion coating and a preparation method thereof. The modified carbon nanotubes, glass flakes and zinc powder composite anti-corrosion coating has a synergistic interaction between the modified carbon nanotubes, glass flakes and zinc powder, so that the coating has excellent comprehensive properties (including wear resistance, adhesion, impact resistance, salt spray resistance, etc.), and has significant performance advantages over traditional epoxy zinc-rich anti-corrosion coatings. At the same time, the coating uses less zinc powder and has low cost, and is suitable for large-scale promotion and application.

[0035] 2. A zinc powder composite anti-corrosion coating and a preparation method thereof. The preparation process of the zinc powder composite anti-corrosion coating is simple and suitable for large-scale preparation by modifying carbon nanotubes, glass flakes and zinc powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 The present invention is a schematic flow chart of a method for preparing a zinc powder composite anti-corrosion coating. DETAILED DESCRIPTION

[0037] The technical solution of this patent is further described in detail below in conjunction with specific implementation methods.

[0038] The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0039] Example 1

[0040] A zinc powder composite anticorrosive coating, comprising a component A and a component B, wherein the component A is made of the following raw materials: 30-35 parts by mass of epoxy resin, 8-12 parts by mass of toughening diluent, 0.8-1.5 parts by mass of carbon nanotubes, 7-10 parts by mass of glass flakes, 20-25 parts by mass of zinc powder, 8-12 parts by mass of pigments and fillers, 1-1.5 parts by mass of surface modifiers, 3-4 parts by mass of additives, and 10-13 parts by mass of solvents;

[0041] Component B is made of the following raw materials: 10-14 parts by weight of curing agent and 1-2 parts by weight of adhesion promoter;

[0042] The epoxy equivalent of the epoxy resin is 400-600 g / eq;

[0043] The viscosity of the toughening diluent is 30-1200 mPa·s (25°C);

[0044] The carbon nanotube is at least one of a hydroxylated carbon nanotube and a carboxylated carbon nanotube, with a hydroxyl or carboxyl content of 1-4 wt % and a length of 10-50 μm;

[0045] The mesh size of the glass flakes is 300-400 mesh;

[0046] The mesh size of the zinc powder is 500-1000 mesh.

[0047] The pigment filler is at least one of titanium dioxide, barium sulfate and talcum powder;

[0048] The surface modifier is at least one of 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropylmethyldimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane;

[0049] The auxiliary agent is at least one of a dispersant, a thickener, a defoamer, and a leveling agent;

[0050] The solvent is at least one of dibutyl ether, xylene and n-butanol;

[0051] The curing agent is at least one of a phenolic amide curing agent, a polyamide curing agent, and a phenolic amine curing agent;

[0052] The adhesion promoter is at least one of 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane and 3-aminopropyltriethoxysilane;

[0053] The epoxy resin in component A contains epoxy groups, and the curing agent in component B contains active hydrogen atoms. When the two are mixed, the epoxy groups and the active hydrogen atoms in the curing agent undergo a ring-opening addition reaction to form a three-dimensional network structure, thereby forming the resin matrix of the anti-corrosion coating of the present invention;

[0054] The toughening diluent not only acts as a liquid matrix for the modification of carbon nanotubes and glass flakes together with the solvent, but also reduces the viscosity of the coating and improves the toughness of the coating film;

[0055] Carbon nanotubes can not only enhance the toughness of the coating, but also form a stable conductive grid in the coating due to their one-dimensional linear structure, effectively improving the utilization rate of zinc powder, enhancing the cathodic protection performance of zinc powder, and reducing the amount of zinc powder used;

[0056] Glass flakes have a two-dimensional flaky structure and high hardness. When arranged layer by layer in the coating, the labyrinth structure formed can enhance the density of the coating, reduce the pores formed by the stacking of spherical zinc powder and pigment fillers in the coating, and significantly improve the anti-penetration performance, corrosion resistance life and wear resistance of the coating;

[0057] Zinc powder has a one-dimensional spherical structure and will preferentially undergo oxidation reaction in a corrosive environment, thereby protecting the iron substrate from corrosion. Therefore, zinc powder in the coating provides cathodic protection for metals such as steel by sacrificing itself. Through the synergistic interaction with modified carbon nanotubes and glass flakes, the coating has excellent anti-corrosion properties.

[0058] Pigments and fillers can not only reduce the cost of coatings, provide the color and hiding power required by the coating, but also improve the mechanical and construction properties of the coating;

[0059] The surface modifier contains epoxy and silane groups, wherein the silane groups can react with the hydroxyl and carboxyl groups on the surfaces of hydroxylated carbon nanotubes (mainly containing hydroxyl groups on the surface), carboxylated carbon nanotubes (mainly containing carboxyl groups on the surface), and glass flakes (mainly containing hydroxyl groups on the surface) to form covalent bonds, while the epoxy groups not only have affinity with epoxy resins, thereby improving the dispersion properties of carbon nanotubes and glass flakes, but also can react with the curing agent in component B to form covalent bonds, further enhancing the bonding strength between carbon nanotubes and glass flakes and epoxy resin base materials, thereby transferring their excellent properties to the coating;

[0060] The additive in the present invention has the functions of promoting the dispersion of carbon nanotubes and pigments and fillers, adjusting the viscosity of the coating, promoting the parallel arrangement of glass flakes, and eliminating bubbles in the coating;

[0061] The solvent not only serves as a liquid matrix for the modification of carbon nanotubes and glass flakes, but also has the function of adjusting the viscosity of the coating and improving the processing and construction performance of the coating;

[0062] The adhesion promoter used in the present invention is used to improve the adhesion of the coating film on the surface of the steel substrate.

[0063] Example 2

[0064] A method for preparing a zinc powder composite anti-corrosion coating comprises the following steps:

[0065] S1: 10 parts by mass of toughening diluent (Cardolite LITE 547LV, 700 mPa·s), 1 part by mass of dispersant (Aike Chuang ECO-2900), and 1.2 parts by mass of carbon nanotubes (Xianfeng Nano, hydroxylated multi-walled carbon nanotubes, hydroxyl content 3.06wt%, length 10-30μm) were added to 11 parts by mass of solvent (xylene and n-butanol mass ratio is 4:1), and treated at 40kHz ultrasonic frequency for 30min, and then 8 parts by mass of glass flakes (Xuhan, 400 mesh) and 1.3 parts by mass of surface modifier (2-(3,4-epoxycyclohexyl)ethyltriethoxysilane) were added, and stirred at 1000rpm for 45min to obtain a modified carbon nanotube / glass flake mixture;

[0066] S2: Weigh 32 parts by mass of epoxy resin (Nan Ya NPES-901, 450-500 g / eq) and 10 parts by mass of pigments and fillers (mass ratio of titanium dioxide, barium sulfate and talc is 2:2:3) and add them to the modified carbon nanotube / glass flake mixture described in step S1, stir at 1300 rpm for 80 min, then add 23 parts by mass of zinc powder (Daxiao Chemical, 1000 mesh), 0.5 parts by mass of thickener (Yoshida Chemical J0602), 1 part by mass of leveling agent (BYK-354), and 1 part by mass of defoamer (BYK-1765) in sequence at 700 rpm, stir for 20 min to obtain component A;

[0067] S3: Add 1.5 parts by mass of adhesion promoter (3-aminopropylmethyldimethoxysilane) to 12 parts by mass of curing agent (Junjiang D8115A), and stir at 1800 rpm for 9 minutes to obtain component B;

[0068] S4: Component A obtained in step S2 and component B obtained in step S3 are mixed, and stirred at a rotation speed of 1200 rpm for 5 minutes to obtain a modified carbon nanotube / glass flake / zinc powder composite anti-corrosion coating.

[0069] Example 3

[0070] A method for preparing a zinc powder composite anti-corrosion coating comprises the following steps:

[0071] S1: 8 parts by mass of toughening diluent (Cardolite LITE 2100R, 500-1000 mPa·s), 0.8 parts by mass of dispersant (Aike Chuang ECO-2900), and 1 part by mass of carbon nanotubes (Xianfeng Nano, carboxylated multi-walled carbon nanotubes, carboxyl content 2wt%, length 10-30 μm) were added to 13 parts by mass of solvent (the mass ratio of dibutyl ester, xylene and n-butanol is 3:4:1), and treated at an ultrasonic frequency of 40 kHz for 35 minutes, and then 7 parts by mass of glass flakes (Baijiang, 325 mesh) and 1 part by mass of surface modifier (3-glycidyloxypropylmethyldiethoxysilane) were added, and stirred at a speed of 800 rpm for 50 minutes to obtain a modified carbon nanotube / glass flake mixture;

[0072] S2: Weigh 34 parts by mass of epoxy resin (Dow DER 671, 475-550 g / eq) and 8 parts by mass of pigments and fillers (mass ratio of titanium dioxide to talc is 3:2) and add them to the modified carbon nanotube / glass flake mixture described in step S1, stir at 1200 rpm for 70 min, then add 25 parts by mass of zinc powder (Daxiao Chemical, 800 mesh), 0.2 parts by mass of thickener (Yoshida Chemical J0602), 1 part by mass of leveling agent (BYK-354), and 1 part by mass of defoamer (BYK-A530) in sequence at 800 rpm, stir for 15 min to obtain component A;

[0073] S3: Add 2 parts by mass of adhesion promoter (3-aminopropylmethyldiethoxysilane) to 10 parts by mass of curing agent (Evonik Ancamide 350A), and stir at 1600 rpm for 5 min to obtain component B;

[0074] S4: Component A obtained in step S2 and component B obtained in step S3 are mixed, and stirred at a rotation speed of 1500 rpm for 3 minutes to obtain a modified carbon nanotube / glass flake / zinc powder composite anti-corrosion coating.

[0075] Example 4

[0076] A method for preparing a zinc powder composite anti-corrosion coating comprises the following steps:

[0077] S1: 12 parts by mass of toughening diluent (D-1217 from Huisheng Electronic Materials Co., Ltd., 40-70 mPa·s), 1 part by mass of dispersant (BYK-9076 from BYK Chemicals), and 1.5 parts by mass of carbon nanotubes (Suzhou Carbonfeng, hydroxylated multi-walled carbon nanotubes, hydroxyl content ~2wt%, length 30-50 μm) were added to 12 parts by mass of solvent (the mass ratio of dibutyl ester to n-butanol is 5:1), and treated at an ultrasonic frequency of 40 kHz for 45 min, and then 10 parts by mass of glass flakes (Xuhan, 400 mesh) and 1.5 parts by mass of surface modifier (3-glycidyloxypropylmethyldimethoxysilane) were added, and stirred at a speed of 500 rpm for 30 min to obtain a modified carbon nanotube / glass flake mixture;

[0078] S2: Weigh 30 parts by mass of epoxy resin (Nan Ya NPES-901, 450-500 g / eq) and 9 parts by mass of pigments and fillers (mass ratio of titanium dioxide to barium sulfate is 2:5) and add them to the modified carbon nanotube / glass flake mixture described in step S1, stir at 1500 rpm for 50 min, then add 20 parts by mass of zinc powder (Daxiao Chemical, 500 mesh), 1 part by mass of thickener (Yoshida Chemical J0602), 1 part by mass of leveling agent (BYK-354), and 1 part by mass of defoamer (BYK-A530) in sequence at 600 rpm, and stir for 30 min to obtain component A;

[0079] S3: Add 2 parts by mass of adhesion promoter (3-aminopropyltrimethoxysilane) to 14 parts by mass of curing agent (Cardolite NX-2003D), and stir at 2000 rpm for 6 minutes to obtain component B;

[0080] S4: Component A obtained in step S2 and component B obtained in step S3 are mixed, and stirred at a rotation speed of 1400 rpm for 4 minutes to obtain a modified carbon nanotube / glass flake / zinc powder composite anti-corrosion coating.

[0081] Example 5

[0082] A method for preparing a zinc powder composite anti-corrosion coating comprises the following steps:

[0083] S1: 9 parts by mass of toughening diluent (YM-004 from Huisheng Electronic Materials Co., Ltd., 55-95 mPa·s), 1 part by mass of dispersant (BYK-9076 from BYK Chemicals), and 0.8 parts by mass of carbon nanotubes (McLean, hydroxylated multi-walled carbon nanotubes, hydroxyl content ~3.7wt%, length ~50 μm) were added successively to 10 parts by mass of solvent (the mass ratio of dibutyl ester to xylene was 3:4), and the mixture was treated at an ultrasonic frequency of 40 kHz for 40 min, and then 9 parts by mass of glass flakes (Xingshuai, 325 mesh) and 1.2 parts by mass of surface modifier (3-glycidyloxypropyltriethoxysilane) were added, and the mixture was stirred at a speed of 600 rpm for 60 min to obtain a modified carbon nanotube / glass flake mixture;

[0084] S2: Weigh 35 parts by mass of epoxy resin (Baling Petrochemical CYD-011, 454-555 g / eq) and 9 parts by mass of pigments and fillers (barium sulfate and talc powder have a mass ratio of 3:7) and add them to the modified carbon nanotube / glass flake mixture described in step S1, stir at 1400 rpm for 100 min, then add 22 parts by mass of zinc powder (Daxiao Chemical, 800 mesh), 1 part by mass of thickener (Yoshida Chemical J0602), 1 part by mass of leveling agent (BYK Chemical BYK-354), and 1 part by mass of defoamer (BYK Chemical BYK-1765) in sequence at 700 rpm, and stir for 25 min to obtain component A;

[0085] S3: Add 1 part by mass of adhesion promoter (3-aminopropyltriethoxysilane) to 13 parts by mass of curing agent (Junjiang D650A), and stir at 1500 rpm for 8 min to obtain component B;

[0086] S4: Component A obtained in step S2 and component B obtained in step S3 are mixed, and stirred at a rotation speed of 1300 rpm for 3 minutes to obtain a modified carbon nanotube / glass flake / zinc powder composite anti-corrosion coating.

[0087] Example 6

[0088] A method for preparing a zinc powder composite anti-corrosion coating comprises the following steps:

[0089] S1: 10 parts by mass of toughening diluent (Cardolite LITE 513DF, 90-200 mPa·s), 1 part by mass of dispersant (BASF Efka PX 4703), and 1.3 parts by mass of carbon nanotubes (Nanjing Suzhan Intelligent Technology, carboxylated multi-walled carbon nanotubes, carboxyl content 1.28wt%, length 10-50 μm) were added to 10 parts by mass of solvent (the mass ratio of dibutyl ester, xylene and n-butanol was 1:4:1), and treated at an ultrasonic frequency of 40 kHz for 35 minutes, and then 10 parts by mass of glass flakes (Xingshuai, 325 mesh) and 1.2 parts by mass of surface modifier (3-glycidyloxypropyltrimethoxysilane) were added, and stirred at a speed of 700 rpm for 55 minutes to obtain a modified carbon nanotube / glass flake mixture;

[0090] S2: Weigh 31 parts by mass of epoxy resin (Nan Ya NPES-901, 450-500 g / eq) and 12 parts by mass of pigments and fillers (mass ratio of titanium dioxide, barium sulfate and talc is 5:2:3) and add them to the modified carbon nanotube / glass flake mixture described in step S1, stir at 1300 rpm for 90 min, then add 21 parts by mass of zinc powder (Daxiao Chemical, 1000 mesh), 0.5 parts by mass of thickener (Yoshida Chemical J0602), 1 part by mass of leveling agent (BYK-354), and 1 part by mass of defoamer (BYK-1765) in sequence at 600 rpm, stir for 20 min to obtain component A;

[0091] S3: Add 1.5 parts by mass of adhesion promoter (3-aminopropylmethyldiethoxysilane) to 11 parts by mass of curing agent (Cardolite LITE 3040), and stir at 1700 rpm for 10 min to obtain component B;

[0092] S4: Component A obtained in step S2 and component B obtained in step S3 are mixed, and stirred at a rotation speed of 1100 rpm for 5 minutes to obtain a modified carbon nanotube / glass flake / zinc powder composite anti-corrosion coating.

[0093] Comparative Example 1

[0094] In this comparative example, a modified glass flake / zinc powder composite anticorrosive coating without carbon nanotubes is prepared by the following steps:

[0095] S1: 10 parts by mass of toughening diluent (Cardolite LITE 547LV, 700 mPa·s), 1 part by mass of dispersant (Aiketron ECO-2900), 8 parts by mass of glass flakes (Xuhan, 400 mesh) and 1.3 parts by mass of surface modifier (2-(3,4-epoxycyclohexyl)ethyltriethoxysilane) were added to 11 parts by mass of solvent (the mass ratio of xylene to n-butanol was 4:1), and stirred at a speed of 1000 rpm for 45 minutes to obtain a modified glass flake mixture;

[0096] S2: Weigh 32 parts by mass of epoxy resin (Nan Ya NPES-901, 450-500 g / eq), 10 parts by mass of pigments and fillers (mass ratio of titanium dioxide, barium sulfate and talc is 2:2:3) and add them to the modified glass flake mixture described in step S1, stir at 1300 rpm for 80 min, then add 24.2 parts by mass of zinc powder (Daxiao Chemical, 1000 mesh), 0.5 parts by mass of thickener (Yoshida Chemical J0602), 1 part by mass of leveling agent (BYK-354), and 1 part by mass of defoamer (BYK-1765) in sequence at 700 rpm, stir for 20 min to obtain component A;

[0097] S3: Add 1.5 parts by mass of adhesion promoter (3-aminopropylmethyldimethoxysilane) to 12 parts by mass of curing agent (Junjiang D8115A), and stir at 1800 rpm for 9 minutes to obtain component B;

[0098] S4: Component A obtained in step S2 and component B obtained in step S3 are mixed, and stirred at a rotation speed of 1200 rpm for 5 minutes to obtain a modified glass flake / zinc powder composite anti-corrosion coating that does not contain carbon nanotubes.

[0099] Comparative Example 2

[0100] In this comparative example, a modified carbon nanotube / zinc powder composite anticorrosive coating without glass flakes is prepared by the following steps:

[0101] S1: 10 parts by mass of toughening diluent (Cardolite LITE 547LV, 700 mPa·s), 1 part by mass of dispersant (Aike Chuang ECO-2900), and 1.2 parts by mass of carbon nanotubes (Xianfeng Nano, hydroxylated multi-walled carbon nanotubes, hydroxyl content 3.06wt%, length 10-30μm) were added to 11 parts by mass of solvent (xylene and n-butanol mass ratio is 4:1), and treated at 40kHz ultrasonic frequency for 30min, and then 1.3 parts by mass of surface modifier (2-(3,4-epoxycyclohexyl)ethyltriethoxysilane) was added, and stirred at 1000rpm for 45min to obtain a modified carbon nanotube mixed solution;

[0102] S2: Weigh 32 parts by mass of epoxy resin (Nan Ya NPES-901, 450-500 g / eq) and 10 parts by mass of pigments and fillers (mass ratio of titanium dioxide, barium sulfate and talc is 2:2:3) and add them to the modified carbon nanotube mixed solution described in step S1, stir at 1300 rpm for 80 min, then add 31 parts by mass of zinc powder (Daxiao Chemical, 1000 mesh), 0.5 parts by mass of thickener (Yoshida Chemical J0602), 1 part by mass of leveling agent (BYK-354), and 1 part by mass of defoamer (BYK-1765) in sequence at 700 rpm, stir for 20 min to obtain component A;

[0103] S3: Add 1.5 parts by mass of adhesion promoter (3-aminopropylmethyldimethoxysilane) to 12 parts by mass of curing agent (Junjiang D8115A), and stir at 1800 rpm for 9 minutes to obtain component B;

[0104] S4: Component A obtained in step S2 and component B obtained in step S3 are mixed, and stirred at a rotation speed of 1200 rpm for 5 minutes to obtain a modified carbon nanotube / zinc powder composite anti-corrosion coating free of glass flakes.

[0105] Comparative Example 3

[0106] This comparative example prepares a conventional epoxy zinc-rich coating without carbon nanotubes and glass flakes by the following steps:

[0107] S1: 20 parts by mass of epoxy resin (Nan Ya NPES-901, 450-500 g / eq), 60 parts by mass of zinc powder (Daxiao Chemical, 1000 mesh), 0.5 parts by mass of thickener (Yoshida Chemical J0602), 1 part by mass of leveling agent (BYK-354), and 1 part by mass of defoamer (BYK-1765) were added to 18.5 parts by mass of solvent (the mass ratio of xylene to n-butanol was 4:1), and the mixture was stirred at 1200 rpm for 45 min to obtain component A;

[0108] S2: Add 1.5 parts by mass of adhesion promoter (3-aminopropylmethyldimethoxysilane) to 6 parts by mass of curing agent (Junjiang D8115A), and stir at 1800 rpm for 9 min to obtain component B;

[0109] S4: Component A obtained in step S2 and component B obtained in step S3 are mixed, and stirred at a rotation speed of 1200 rpm for 5 minutes to obtain a traditional epoxy zinc-rich coating free of carbon nanotubes and glass flakes.

[0110] The anticorrosive coatings prepared in Examples 2-6 and Comparative Examples 1-3 were prepared into test samples according to the standard "GB / T9271-2008 Standard Test Plate for Paints and Varnishes", and the non-volatile content, adhesion, wear resistance, impact resistance and salt spray resistance were tested accordingly. Among them, the test basis for the non-volatile content was "GB / T 1725-2007 Determination of Non-volatile Content of Paints, Varnishes and Plastics"; the adhesion test was based on "GB / T 5210-2006 Adhesion Test for Paints and Varnishes by Pull-off Method"; the wear resistance test was based on "GB / T 1768-2006 Determination of Wear Resistance of Paints and Varnishes by Rotating Rubber Grinding Wheel Method" using 1000g / 1000r, grinding wheel model CS-17; the impact resistance test was based on "GB / T The test basis for salt spray resistance is GB / T 1732-2020 Determination of impact resistance of paint film, and the weight of the hammer is 1000g; the salt spray resistance test is based on GB / T 1771-2007 Determination of neutral salt spray resistance of paints and varnishes. The test results are shown in Table 1:

[0111] Table 1 Comparison of test performance of Examples 2-6 and Comparative Examples 1-3

[0112]

[0113] As can be seen from Table 1, from the comparison of the modified carbon nanotube / glass flake / zinc powder composite anticorrosion coatings of Examples 2-6 with the modified glass flake / zinc powder composite anticorrosion coating without carbon nanotubes in Comparative Example 1 and the modified carbon nanotube / zinc powder composite anticorrosion coating without glass flakes in Comparative Example 2, it can be seen that there is a synergistic interaction between the carbon nanotubes, glass flakes and zinc powder in the modified carbon nanotube / glass flake / zinc powder composite anticorrosion coating, and the two have a promoting effect on enhancing the comprehensive properties of the coating (such as adhesion, wear resistance, impact resistance, salt spray resistance, etc.);

[0114] Compared with the traditional epoxy zinc-rich coating without carbon nanotubes and glass flakes in comparative example 3, the modified carbon nanotube / glass flake / zinc powder composite anti-corrosion coatings of embodiments 2-6 of the present invention have significant performance advantages, higher non-volatile matter content, and less organic solvent usage.

[0115] The above is a preferred specific implementation manner of the present invention, and the protection scope of the present invention is not limited thereto. Any modification, equivalent substitution and improvement made by any technician familiar with the field within the technical scope disclosed by the present invention in combination with the prior art or public common sense, within the spirit and principle of the present invention, shall be covered by the protection scope of the present invention.

Claims

1. A zinc powder composite anti-corrosion coating, characterized in that: The coating is composed of component A and component B, wherein component A comprises the following raw materials in parts by weight: Epoxy resin: 30-35 parts by mass, epoxy equivalent weight 400-600 g / eq; Toughening diluent: 8-12 parts by mass, viscosity 30-1200mPa·s (25°C); Carbon nanotubes: 0.8-1.5 parts by weight, at least one of hydroxylated carbon nanotubes and carboxylated carbon nanotubes, with a hydroxyl or carboxyl content of 1-4 wt% and a length of 10-50 μm; Glass flakes: 7-10 parts by mass, 300-400 mesh; Zinc powder: 20-25 parts by mass, mesh size is 500-1000 mesh; Pigment and filler: 8-12 parts by weight, at least one of titanium dioxide, barium sulfate and talc; Surface modifier: 1-1.5 parts by mass, selected from at least one of 3-glycidyloxypropyltrimethoxysilane, 3-glycidyloxypropyltriethoxysilane, 3-glycidyloxypropylmethyldimethoxysilane, 3-glycidyloxypropylmethyldiethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane and 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane; Additives: 3-4 parts by mass, at least one of a dispersant, a thickener, a defoamer, and a leveling agent; Solvent: 10-13 parts by mass, at least one of dibutyl ether, xylene, and n-butanol; The second component comprises the following raw materials in parts by weight: Curing agent: 10-14 parts by weight, at least one of phenolic amide curing agent, polyamide curing agent, and phenolic amine curing agent; Adhesion promoter: 1-2 parts by mass, at least one selected from 3-aminopropylmethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, 3-aminopropyltrimethoxysilane, and 3-aminopropyltriethoxysilane.

2. A zinc powder composite anti-corrosion coating according to claim 1, characterized in that: The epoxy resin in component A contains epoxy groups, and the curing agent in component B contains active hydrogen atoms. When the two are mixed, the epoxy groups and the active hydrogen atoms in the curing agent undergo a ring-opening addition reaction to form a three-dimensional network structure and then form a resin matrix for the anti-corrosion coating.

3. A zinc powder composite anti-corrosion coating according to claim 2, characterized in that: The surface modifier contains epoxy and siloxy groups, wherein the siloxy groups can react with hydroxyl and carboxyl groups on the surface of hydroxylated carbon nanotubes (mainly containing hydroxyl groups on the surface), carboxylated carbon nanotubes (mainly containing carboxyl groups on the surface), and glass flakes (mainly containing hydroxyl groups on the surface) to form covalent bonds.

4. A zinc powder composite anti-corrosion coating according to claim 3, characterized in that: The epoxy group has an affinity for the epoxy resin and reacts with the curing agent in component B to form a covalent bond.

5. A zinc powder composite anti-corrosion coating according to claim 4, characterized in that: The solvent modifies the liquid matrix of carbon nanotubes and glass flakes.

6. A method for preparing the zinc powder composite anti-corrosion coating according to any one of claims 1 to 5, characterized in that: The following steps are involved: S1: Add toughening diluent, dispersant and carbon nanotubes to the solvent in sequence, treat under ultrasonic frequency, then add glass flakes and surface modifier, and stir to obtain modified carbon nanotube / glass flake mixed solution; S2: adding epoxy resin and pigments and fillers to the mixed solution obtained in step S1, stirring, and then sequentially adding zinc powder, thickener, leveling agent, and defoamer, and continuing to stir to obtain component A; S3: adding the adhesion promoter to the curing agent and stirring to obtain component B; S4: Mix the component A obtained in step S2 and the component B obtained in step S3, and stir to obtain a zinc powder composite anti-corrosion coating.

7. A zinc powder composite anticorrosive coating and a preparation method thereof according to claim 6, characterized in that: In step S1, the ultrasonic frequency is 40 kHz, the treatment time is 20-45 minutes, the stirring speed is 800-1200 rpm, and the stirring time is 30-60 minutes.

8. A zinc powder composite anticorrosive coating and a preparation method thereof according to claim 7, characterized in that: In step S2, the stirring speed is 1200-1500 rpm, and the stirring time is 50-100 minutes.

9. A zinc powder composite anticorrosive coating and a preparation method thereof according to claim 8, characterized in that: In step S3, the stirring speed is 1500-2000 rpm, and the stirring time is 5-10 minutes.

10. A zinc powder composite anticorrosive coating and a preparation method thereof according to claim 9, characterized in that: In step S4, the stirring speed is 1100-1500 rpm, and the stirring time is 3-5 minutes.

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