Waterborne anticorrosive coating, method for preparing the same, and use thereof

Abstract

This invention relates to the field of corrosion protection, specifically to a water-based anti-corrosion coating, its preparation method, and its application. The water-based anti-corrosion coating of this invention, by weight, comprises: 0.5-3 parts graphene, 5-40 parts matrix resin, 0.01-0.1 parts cobalt-free drying agent, 0.2-0.8 parts polyurethane thickener, 0.1-0.8 parts alkanolamine, 0.1-2 parts organosilicon dispersant, 30-65 parts inorganic filler, and 20-50 parts water. The water-based anti-corrosion coating of this invention has the advantages of rapid drying (<30 min), excellent water resistance, good salt spray corrosion resistance, and high adhesion.

Description

Technical Field

[0001] This invention relates to the field of corrosion protection, specifically to a water-based anti-corrosion coating, its preparation method, and its application. Background Technology

[0002] Driven by energy conservation, emission reduction, and low-carbon environmental protection concepts and policies, water-based coatings have been widely used in municipal steel structures, construction machinery, and other fields due to their advantages such as low VOC content, good substrate wettability, and excellent decorative effect. However, commercially available products suffer from problems such as slow drying, poor water resistance, and poor salt spray corrosion resistance.

[0003] CN113755036B discloses the application of modified graphene oxide in water-based coatings. Through modification with polydopamine and zinc nitrate, the agglomeration of graphene oxide is significantly improved, its dispersibility is enhanced, and thus the anti-corrosion performance of water-based anti-corrosion coatings is significantly improved. However, the above system is a water-based epoxy system, and its curing effect and speed are greatly affected by the curing agent, which is not suitable for extensive field construction.

[0004] CN113913113A discloses a method for preparing water-based ultra-fast drying anti-corrosion coatings. This method involves reacting amino-terminated dimethyl silicone oil with graphene oxide to obtain modified graphene / organosilicon oil, which is then used to prepare a water-based ultra-fast drying anti-corrosion coating for oil pipelines. However, due to the inherent properties of the graphene oxide used, the overall effect did not meet expectations.

[0005] Currently, there is limited research in this field on graphene-based waterborne anti-corrosion coatings that combine the technical characteristics of rapid drying, excellent water resistance, good salt spray corrosion resistance, and high adhesion. Developing anti-corrosion coatings that can dry quickly (<30min), have excellent water resistance, good salt spray corrosion resistance, and high adhesion is a technical challenge in this field. Summary of the Invention

[0006] To overcome the problems of poor water resistance, poor salt spray corrosion resistance, slow drying speed, and poor adhesion of existing water-based anti-corrosion coatings, this invention provides a water-based anti-corrosion coating, its preparation method, and its application. The water-based anti-corrosion coating of this invention has the advantages of rapid drying (<30min), excellent water resistance, good salt spray corrosion resistance, and high adhesion.

[0007] To achieve the above objectives, a first aspect of the present invention provides a water-based anti-corrosion coating, comprising, by weight: Graphene 0.5-3 parts, matrix resin 5-40 parts, cobalt-free drying agent 0.01-0.1 parts, polyurethane thickener 0.2-0.8 parts, alkanolamine 0.1-0.8 parts, organosilicon dispersant 0.1-2 parts, inorganic filler 30-65 parts, water 20-50 parts.

[0008] A second aspect of the present invention provides a method for preparing the water-based anti-corrosion coating of the present invention, the method comprising: mixing the components of the coating.

[0009] A third aspect of the present invention provides an aqueous anti-corrosion coating comprising: 0.5-3 parts graphene, 5-40 parts matrix resin, 0.01-0.1 parts cobalt-free drier, 0.2-0.8 parts polyurethane thickener, 0.1-0.8 parts alkanolamine, 0.1-2 parts organosilicon dispersant, and 30-65 parts inorganic filler.

[0010] A fourth aspect of the present invention provides a water-based anti-corrosion coating, wherein the water-based anti-corrosion coating is obtained by spraying, rolling, brushing or dipping after mixing the components of the water-based anti-corrosion coating of the present invention.

[0011] The fifth aspect of this invention provides an application of the water-based anti-corrosion coating or water-based anti-corrosion coating of this invention in metal corrosion protection.

[0012] Through the above technical solution, the water-based anti-corrosion coating of the present invention has the advantages of rapid drying (<30min), excellent water resistance, good salt spray corrosion resistance, and high adhesion. It solves the technical problems of cracking, blistering, adhesion degradation, and poor corrosion resistance of traditional water-based coatings after long-term immersion in water, and significantly improves the durability of the coating under long-term immersion in liquid.

[0013] Meanwhile, the anti-corrosion coating of the present invention can achieve zero addition of traditional anti-corrosion fillers such as zinc and aluminum while ensuring rapid drying and guaranteeing the coating's water resistance, salt spray corrosion resistance, and high adhesion.

[0014] The anti-corrosion coating of this invention, in combination with a cobalt-free drier, significantly improves the rapid drying and curing speed of the coating, reducing the surface drying time of the coating from the traditional 1-2 hours to less than 30 minutes, thus improving the ease of application. Detailed Implementation

[0015] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0016] The first aspect of this invention provides a water-based anti-corrosion coating, comprising, by weight: The composition includes 0.5-3 parts graphene, 5-40 parts matrix resin, 0.01-0.1 parts cobalt-free drier, 0.2-0.8 parts polyurethane thickener, 0.1-0.8 parts alkanolamine, 0.1-2 parts organosilicon dispersant, 30-65 parts inorganic filler, and 20-50 parts water. The water-based anti-corrosion coating of this invention has the advantages of rapid drying (<30 min), excellent water resistance, good salt spray corrosion resistance, and high adhesion.

[0017] According to a preferred embodiment of the present invention, the graphene content in the water-based anti-corrosion coating is 0.5-2 parts by weight.

[0018] According to a preferred embodiment of the present invention, the matrix resin in the water-based anticorrosive coating is 15-35 parts by weight.

[0019] According to a preferred embodiment of the present invention, the cobalt-free drier in the water-based anticorrosive coating is 0.03-0.05 parts by weight.

[0020] According to a preferred embodiment of the present invention, the polyurethane thickener in the water-based anticorrosive coating is 0.4-0.6 parts by weight.

[0021] According to a preferred embodiment of the present invention, the water-based anticorrosive coating contains 0.2-0.5 parts by weight of alkanolamine.

[0022] According to a preferred embodiment of the present invention, the organosilicon dispersant in the water-based anticorrosive coating is 0.2-1 parts by weight.

[0023] According to a preferred embodiment of the present invention, the inorganic filler in the water-based anticorrosive coating is 20-45 parts by weight.

[0024] According to a preferred embodiment of the present invention, the water content in the water-based anti-corrosion coating is 30-45 parts by weight.

[0025] The anti-corrosion coating of the present invention can achieve zero addition of traditional anti-corrosion fillers such as zinc and aluminum while ensuring the coating's water resistance, salt spray corrosion resistance, and high adhesion. According to a preferred embodiment of the present invention, the coating does not contain zinc or cobalt.

[0026] In this invention, the range of solid content in the coating is relatively wide, which is illustrative but does not limit the scope of the invention. According to a preferred embodiment of the invention, the solid mass fraction of the coating is 45wt%-65wt%.

[0027] According to a preferred embodiment of the present invention, the cobalt-free drying agent contains vanadium, which can improve the rapid drying and curing speed of the coating. The use of vanadium isooctanoate as a cobalt-free drying agent in this embodiment exemplifies the advantages of the present invention, but does not limit the scope of the invention.

[0028] In this invention, the vanadium content in the cobalt-free drying agent can be selected from a wide range. This is an illustrative example, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the vanadium content in the cobalt-free drying agent is not less than 2.5 wt%, preferably 5-7 wt%.

[0029] In this invention, an alcoholamine refers to an organic compound that contains both amino (-NH2) and hydroxyl (-OH) functional groups in its molecule. For example, it can be one or more of ethanolamine (monoethanolamine, diethanolamine, triethanolamine, etc.), diisopropanolamine, methyldiethanolamine, 2-amino-2-methyl-1-propanol, and butanolamine. According to a preferred embodiment of this invention, the alcoholamine is selected from one or more of 2-amino-2-methyl-1-propanol, ethanolamine, and butanolamine.

[0030] In this invention, the viscosity of the polyurethane thickener can be selected over a wide range. According to a preferred embodiment of this invention, the viscosity of the polyurethane thickener at 25°C is 5000-40000 mPa•s, for example, 10000 mPa•s, 15000 mPa•s, 20000 mPa•s, 25000 mPa•s, 30000 mPa•s, 32000 mPa•s, 34000 mPa•s, 35000 mPa•s, 36000 mPa•s, 38000 mPa•s, 39000 mPa•s, preferably 25000-40000 mPa•s. The synergistic effect of polyurethane thickeners with viscosities in the aforementioned range (mPa•s) and alkanolamines and organosilicon dispersants enhances the dispersibility and stability of graphene and inorganic fillers in the coating. This results in high viscosity and good wetting effect while maintaining good fluidity and wettability, avoiding problems such as demulsification and sedimentation during long-term storage of traditional water-based coatings. Consequently, the coating exhibits excellent salt spray corrosion resistance.

[0031] In this invention, the viscosity range of the organosilicon dispersant is relatively wide. According to a preferred embodiment of the invention, the viscosity of the organosilicon dispersant at 25°C is 50-100 mPa•s, for example, 60 mPa•s, 70 mPa•s, 80 mPa•s, or 90 mPa•s. The synergistic effect of the organosilicon dispersant with viscosity in the aforementioned range, along with the alkanolamine and polyurethane thickener, improves the dispersion stability of graphene and inorganic fillers in the coating and the stability of the coating. This allows the coating to maintain good fluidity and wettability while having high viscosity and good wetting effect, avoiding problems such as demulsification and sedimentation during long-term storage of traditional water-based coatings. As a result, the coating exhibits excellent salt spray corrosion resistance.

[0032] In this invention, the range of types of organosilicon dispersants is relatively wide. This is an illustrative example, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the organosilicon dispersant is selected from one or more of Tego-270, Tego-260, Tego-280, Tego-500 and Tego-4000.

[0033] In this invention, the carbon content in graphene can be selected from a wide range, which is illustrative but does not limit the scope of the invention. According to a preferred embodiment of the invention, the carbon content of graphene is 85wt%-99.5wt% by mass.

[0034] In this invention, the particle size of graphene can be selected from a wide range. According to a preferred embodiment of this invention, the D90 particle size of graphene is 10-35μm, for example, 12μm, 14μm, 16μm, 18μm, 20μm, 22μm, 25μm, 27μm, 29μm, preferably 15μm-30μm. This invention improves the shielding properties of the coating by introducing large-diameter graphene, extends the diffusion path of corrosive agents, and can improve the durability of the coating under long-term immersion in liquid.

[0035] In this invention, the range of types of matrix resins that can be selected is relatively wide. According to a preferred embodiment of this invention, the matrix resin is selected from one or more of acrylic resins, alkyd resins and polyurethane resins, preferably alkyd resins. The selection of the aforementioned matrix resin can achieve zero addition of traditional anti-corrosion fillers such as zinc and aluminum, while improving the dispersion stability of graphene in the coating and the stability of the coating.

[0036] In this invention, the range of inorganic fillers that can be selected is relatively wide. This is an illustrative example, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the inorganic filler is selected from one or more of aluminum tripolyphosphate, barium sulfate, titanium dioxide, carbon black, calcium carbonate, flake glass, bentonite, talc, zinc oxide, mica powder, and mica iron oxide.

[0037] In this invention, the inorganic filler is selected from filler 1 and filler 2. According to a preferred embodiment of this invention, filler 1 is selected from one or more of aluminum tripolyphosphate, titanium dioxide, mica powder and calcium carbonate; filler 2 is selected from one or more of bentonite, talc, zinc oxide, barium sulfate and carbon black.

[0038] In this invention, the content of filler 1 and filler 2 in the total weight of inorganic filler can be selected within a wide range. According to a preferred embodiment of this invention, filler 1 accounts for 60-80 wt% of the total weight of inorganic filler, and filler 2 accounts for 20-40 wt% of the total weight of inorganic filler.

[0039] A second aspect of this invention provides a method for preparing the water-based anti-corrosion coating of this invention, the method comprising: mixing the components of the coating. The water-based anti-corrosion coating prepared by the method of this invention has the advantages of rapid drying (<30 min), excellent water resistance, good salt spray corrosion resistance, and high adhesion.

[0040] According to a preferred embodiment of the present invention, the method for preparing the water-based anti-corrosion coating includes: (1) Mix graphene, matrix resin, alkanolamine, polyurethane thickener, filler 1 and deionized water, perform first shear dispersion and first grinding; (2) The product of step (1) is mixed with filler 2, cobalt-free drying agent, organosilicon dispersant, and deionized water, followed by second shear dispersion and second grinding.

[0041] In this invention, the amount of deionized water used in step (1) can be selected from a wide range. This is an illustrative example, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the amount of deionized water used in step (1) accounts for 50wt%-70wt% of the total amount of deionized water.

[0042] In this invention, the amount of deionized water used in step (2) has a wide range of options. This is an illustrative example, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the amount of deionized water used in step (2) accounts for 30wt%-50wt% of the total amount of deionized water.

[0043] In this invention, the first grinding conditions are not particularly limited; conventional grinding conditions in the art are sufficient. This is an illustrative example, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the first grinding conditions include: grinding to a fineness ≤25μm, for example, a sand mill can be used for the grinding. Preferably, the grinding media of the sand mill is 0.8mm-1.mm zirconium beads; the rotation speed is 400-600rpm; and the time can be determined according to the actual situation, generally 30-60min.

[0044] In this invention, the second grinding conditions are not particularly limited; conventional grinding conditions in the art are sufficient. This is an illustrative example, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the second grinding conditions include: grinding to a fineness ≤30μm, for example, a sand mill can be used for the grinding. Preferably, the grinding media of the sand mill is 0.8mm-1.5mm zirconium beads; the rotation speed is 400-600rpm; and the time can be determined according to the actual situation, generally 15-30min.

[0045] In this invention, the first shearing condition is not particularly limited; conventional shearing conditions in the art are sufficient. This is an illustrative example, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the first shearing condition includes: a rotation speed of 1200 rpm to 1500 rpm; a temperature of 30 to 50°C; and a time that can be determined according to the actual situation, generally 10 to 60 minutes.

[0046] In this invention, the second shearing condition is not particularly limited; conventional shearing conditions in the art are sufficient. This is an illustrative example, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the second shearing condition includes: a rotational speed of 800 rpm to 1500 rpm; and a time that can be determined according to the actual situation, generally 10 to 30 minutes.

[0047] A third aspect of the present invention provides an aqueous anti-corrosion coating comprising: 0.5-3 parts graphene, 5-40 parts matrix resin, 0.01-0.1 parts cobalt-free drier, 0.2-0.8 parts polyurethane thickener, 0.1-0.8 parts alkanolamine, 0.1-2 parts organosilicon dispersant, and 30-65 parts inorganic filler.

[0048] According to a preferred embodiment of the present invention, the cobalt-free drying agent contains vanadium.

[0049] In this invention, the vanadium content in the cobalt-free drying agent can be selected from a wide range. This is an illustrative example, but it does not limit the scope of the invention. According to a preferred embodiment of the invention, the vanadium content in the cobalt-free drying agent is not less than 2.5 wt%, preferably 5-7 wt%.

[0050] In this invention, an alcoholamine refers to an organic compound that contains both amino (-NH2) and hydroxyl (-OH) functional groups in its molecule. For example, it can be one or more of ethanolamine (monoethanolamine, diethanolamine, triethanolamine, etc.), diisopropanolamine, methyldiethanolamine, 2-amino-2-methyl-1-propanol, and butanolamine. According to a preferred embodiment of this invention, the alcoholamine is selected from one or more of 2-amino-2-methyl-1-propanol, ethanolamine, and butanolamine.

[0051] In this invention, the viscosity of the polyurethane thickener can be selected over a wide range. According to a preferred embodiment of this invention, the viscosity of the polyurethane thickener at 25°C is 5000-40000 mPa•s, for example, 10000 mPa•s, 15000 mPa•s, 20000 mPa•s, 25000 mPa•s, 30000 mPa•s, 32000 mPa•s, 34000 mPa•s, 35000 mPa•s, 36000 mPa•s, 38000 mPa•s, 39000 mPa•s, preferably 25000-40000 mPa•s. The synergistic effect of polyurethane thickeners with viscosities in the aforementioned range (mPa•s) and alkanolamines and organosilicon dispersants enhances the dispersibility and stability of graphene and inorganic fillers in the coating. This results in high viscosity and good wetting effect while maintaining good fluidity and wettability, avoiding problems such as demulsification and sedimentation during long-term storage of traditional water-based coatings. Consequently, the coating exhibits excellent salt spray corrosion resistance.

[0052] In this invention, the viscosity range of the organosilicon dispersant is relatively wide. According to a preferred embodiment of the invention, the viscosity of the organosilicon dispersant at 25°C is 50-100 mPa•s, for example, 60 mPa•s, 70 mPa•s, 80 mPa•s, or 90 mPa•s. The synergistic effect of the organosilicon dispersant with viscosity in the aforementioned range, along with the alkanolamine and polyurethane thickener, improves the dispersion stability of graphene and inorganic fillers in the coating and the stability of the coating. This allows the coating to maintain good fluidity and wettability while having high viscosity and good wetting effect, avoiding problems such as demulsification and sedimentation during long-term storage of traditional water-based coatings. As a result, the coating exhibits excellent salt spray corrosion resistance.

[0053] In this invention, the range of types of matrix resins that can be selected is relatively wide. According to a preferred embodiment of this invention, the matrix resin is selected from one or more of acrylic resins, alkyd resins and polyurethane resins, preferably alkyd resins. The selection of the aforementioned matrix resin can achieve zero addition of traditional anti-corrosion fillers such as zinc and aluminum, while improving the dispersion stability of graphene in the coating and the stability of the coating.

[0054] In this invention, the range of inorganic fillers that can be selected is relatively wide. This is an illustrative example, but it does not limit the scope of this invention. According to a preferred embodiment of this invention, the inorganic filler is selected from one or more of aluminum tripolyphosphate, barium sulfate, titanium dioxide, carbon black, calcium carbonate, flake glass, bentonite, talc, zinc oxide, mica powder, and mica iron oxide.

[0055] A fourth aspect of this invention provides a water-based anti-corrosion coating, which is obtained by spraying, roller coating, brushing, or dipping the water-based anti-corrosion coating of this invention. The anti-corrosion coating of this invention has the advantages of fast drying and curing speed and good stability.

[0056] In this invention, the thickness of the water-based anti-corrosion coating can be selected from a wide range, which is illustrative but does not limit the scope of the invention. According to a preferred embodiment of the invention, the thickness is 30-300 μm.

[0057] In this invention, the adhesion of the water-based anti-corrosion coating has a wide range of selectable values. According to a preferred embodiment of this invention, the adhesion of the coating is ≥3MPa, preferably 4-6 MPa.

[0058] According to one embodiment of the present invention, the water-based anti-corrosion coating comprises: 0.5-3 parts graphene, 5-40 parts matrix resin, 0.01-0.1 parts cobalt-free drier, 0.2-0.8 parts polyurethane thickener, 0.1-0.8 parts alkanolamine, 0.1-2 parts organosilicon dispersant, and 30-65 parts inorganic filler.

[0059] The fifth aspect of this invention provides an application of the water-based anti-corrosion coating or water-based anti-corrosion coating of this invention in metal corrosion protection.

[0060] The preferred application of the water-based anti-corrosion coating or water-based anti-corrosion coating of the present invention in metal corrosion protection in the petroleum, chemical, power and electronics industries, such as petrochemical pipelines.

[0061] In the context and embodiments of this invention, the basic performance of the water-based anti-corrosion coating is tested according to HG / T4847-2015, the water resistance test is conducted according to GB / T 1733-1993, the salt spray resistance test is conducted according to GB / T1771-2007, the film adhesion test is conducted according to GB / T 5210-1985, and the film is cleaned before coating according to GB / T8923.1-2011.

[0062] To further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention, and not for limiting the scope of the claims of the present invention.

[0063] In the following embodiments, the coatings are applied using a two-coat spraying process, with a 3-hour interval between the two sprays, and the coating thickness is 60 μm.

[0064] In the following examples, the viscosity of the polyurethane thickener (Vesmody U605) is 28000 mPa•s, the viscosity of the polyurethane thickener (Enze Chemical, PU-40) is 5000-8000 mPa•s, the viscosity of the acrylic thickener (TT-936) is 100 mPa•s, the viscosity of the silicone dispersant (TEGO-260) is 90 mPa•s, the viscosity of the silicone dispersant (TEGO-270) is 50 mPa•s, and the viscosity of the silicone dispersant (TEGO-280) is 70 mPa•s.

[0065] Example 1 (1) Take 2 parts of graphene powder with a D90 particle size of 18μm, wherein the carbon content in the graphene is 99.5 wt%, 35 parts of alkyd resin (Wanswell 575-1, Changzhou Sisai New Materials), 0.2 parts of 2-amino-2-methyl-1-propanol, 0.6 parts of polyurethane thickener (Vesmody U605), 5 parts of titanium dioxide, 2 parts of aluminum tripolyphosphate, 8 parts of mica powder, and 25 parts of deionized water, add them to a high-speed shear mixer, adjust the speed to 1200 rpm, shear and disperse for 60 min, control the shear temperature to 40℃, until all solids are evenly dispersed and no stratification occurs; transfer the sheared product into a sand mill, grind at 500 rpm for 60 min, and grind to a fineness ≤25μm.

[0066] (2) After grinding the product in step (1), add 0.2 parts of organosilicon dispersant (TEGO-260), 0.03 parts of vanadium isooctanoate with a vanadium content of 5wt%, 5 parts of bentonite, 2 parts of zinc oxide, and 15 parts of deionized water to a high-speed shear mixer. Shear and disperse at 1000 rpm for 10 min, then transfer to a sand mill at 500 rpm and grind for 30 min until the fineness is ≤30μm to obtain a water-based anti-corrosion coating containing graphene.

[0067] (3) Apply the graphene-containing water-based anti-corrosion coating to the pre-treated carbon steel substrate by spraying (spraying pressure 0.6MPa).

[0068] The coating was tested using the aforementioned test standards: the solid content of the obtained coating was 56%±1%, the adhesion of the water-based anti-corrosion coating was 5MPa; the surface drying time of the coating obtained by spraying was 15min, and the skinning test within 48h was qualified; it passed the water resistance test for 150h; and it passed the neutral salt spray resistance test for 300h.

[0069] Example 2 (1) Take 0.5 parts of graphene powder with a D90 particle size of 24 μm, wherein the carbon content in the graphene is 99.5 wt%, 15 parts of alkyd resin (Wanswell 575-1, Changzhou Sisai New Materials), 0.5 parts of 2-amino-2-methyl-1-propanol, 0.4 parts of polyurethane thickener (Vesmody U605), 15 parts of titanium dioxide, 5 parts of aluminum tripolyphosphate, 10 parts of mica powder, and 20 parts of deionized water, add them to a high-speed shear mixer, adjust the speed to 1200 rpm, shear and disperse for 60 min, control the shear temperature to 40℃, until all solids are evenly dispersed and no stratification occurs; transfer the sheared product into a sand mill, grind at 500 rpm for 60 min, grind until the fineness is ≤25 μm.

[0070] (2) After grinding, add 1 part of organosilicon dispersant (TEGO-270), 0.05 parts of vanadium isooctanoate with a vanadium content of 5 wt%, 5 parts of bentonite, 10 parts of zinc oxide, and 17.6 parts of deionized water to a high-speed shear mixer. Shear and disperse at 1000 rpm for 10 min, then transfer to a sand mill at 500 rpm and grind for 30 min until the fineness is ≤30 μm to obtain a water-based anti-corrosion coating containing graphene.

[0071] (3) Apply the graphene-containing water-based anti-corrosion coating to the pre-treated carbon steel substrate by spraying (spraying pressure 0.6MPa).

[0072] The coating was tested using the aforementioned test standards: the solid content of the obtained coating was 63%±1%, the adhesion of the water-based anti-corrosion coating was 5MPa; the surface drying time of the coating obtained by spraying was 10min, and the skinning test within 48h was qualified; it passed the water resistance test for 140h; and it passed the neutral salt spray resistance test for 275h.

[0073] Example 3 (1) Take 2 parts of graphene powder with a D90 particle size of 30μm, wherein the carbon content in the graphene is 99.5 wt%, 15 parts of alkyd matrix resin (Wanswell 575-1, Changzhou Sisai New Materials), 0.5 parts of 2-amino-2-methyl-1-propanol, 0.5 parts of polyurethane thickener (Vesmody® U605), 10 parts of titanium dioxide, 10 parts of aluminum tripolyphosphate, 5 parts of mica powder, and 30 parts of deionized water, add them to a high-speed shear mixer, adjust the speed to 1200 rpm, shear and disperse for 60 min, control the shear temperature to 40℃, until all solids are evenly dispersed and no stratification occurs; transfer the sheared product into a sand mill, grind at 500 rpm for 60 min, and grind to a fineness ≤25μm.

[0074] (2) After grinding, add 1 part of organosilicon dispersant (TEGO-280), 0.05 parts of vanadium isooctanoate with a vanadium content of 5 wt%, 5 parts of bentonite, 5 parts of zinc oxide, and 16 parts of deionized water to a high-speed shear mixer. Shear and disperse at 1000 rpm for 10 min, then transfer to a sand mill at 500 rpm and grind for 30 min until the fineness is ≤30 μm to obtain a water-based anti-corrosion coating containing graphene.

[0075] (3) Apply the graphene-containing water-based anti-corrosion coating to the pre-treated carbon steel substrate by spraying (spraying pressure 0.6MPa).

[0076] The coating was tested using the aforementioned test standards: the solid content of the obtained coating was 54%±1%, the adhesion of the water-based anti-corrosion coating was 6MPa; the surface drying time of the coating obtained by spraying was 15min, and the skinning test within 48h was qualified; it passed the water resistance test for 140h; and it passed the neutral salt spray resistance test for 300h.

[0077] Example 4 The method of Example 1 is the same, except that the vanadium content is 2.5%, and the other conditions are the same as in Example 1.

[0078] The coating was tested using the aforementioned test standards: the solid content of the obtained coating was 56%±1%, the adhesion of the water-based anti-corrosion coating was 5MPa; the surface drying time of the coating obtained by spraying the coating was 25 min, and the skinning test within 48 h was qualified; it passed the water resistance test for 145 h; and it passed the neutral salt spray resistance test for 300 h.

[0079] Example 5 The method of Example 1 is the same, except that the viscosity of the polyurethane thickener is 5000~8000 mPa·s (Enze Chemical, PU-40), and the other conditions are the same as in Example 1.

[0080] The coating was tested using the aforementioned test standards: the solid content of the obtained coating was 56%±1%, the adhesion of the water-based anti-corrosion coating was 4 MPa; the surface drying time of the coating obtained by spraying was 25 min, and the skinning test within 48 h was qualified; it passed the water resistance test for 130 h; and it passed the neutral salt spray resistance test for 240 h.

[0081] Example 6 The method of Example 1 is the same, except that the graphene D90 is 5 μm, and the other conditions are the same as in Example 1.

[0082] The coating was tested using the aforementioned test standards: the solid content of the obtained coating was 56%±1%, the adhesion of the water-based anti-corrosion coating was 5MPa; the surface drying time of the coating obtained by spraying was 15 min, and the skinning test within 48 hours was qualified; it passed the water resistance test for 100 hours; and it passed the neutral salt spray resistance test for 200 hours.

[0083] Example 7 The method of Example 1 is the same as in Example 1, except that in step (1) the filler is 15 parts mica powder and in step (2) the filler is 7 parts mica powder, and the other conditions are the same as in Example 1.

[0084] The coating was tested using the aforementioned test standards: the solid content of the obtained coating was 56%±1%, the adhesion of the water-based anti-corrosion coating was 4MPa; the surface drying time of the coating obtained by spraying was 15 min, and the skinning test within 48h was qualified; it passed the water resistance test for 120 h; and it passed the neutral salt spray resistance test for 220 h.

[0085] Comparative Example 1 The implementation method is the same as in Example 1, except that graphene is replaced with an equal amount of carbon black, and the other conditions are the same as in Example 1.

[0086] The surface drying time is 35 minutes, and the skinning test is passed within 48 hours; it passes the 30-hour water resistance test; it passes the 24-hour neutral salt spray test; the adhesion of the carbon black-containing water-based anti-corrosion coating is 3 MPa. Comparative Example 2 The method of Example 1 is the same as in Example 1, except that vanadium isooctanoate is not added in step (2).

[0087] The coating was tested using the aforementioned test standards: the solid content of the obtained coating was 56%±1%, the adhesion of the water-based anti-corrosion coating was 5MPa; the surface drying time of the coating obtained by spraying the coating was 3 h, and the skinning test within 48 h was qualified; it passed the water resistance test for 150 h; and it passed the neutral salt spray resistance test for 300 h.

[0088] Comparative Example 3 The method of Example 1 was followed, except that an equal number of acrylic thickeners (TT-936) were used instead of polyurethane thickeners (Vesmody U605), and all other conditions were the same as in Example 1.

[0089] The coating was tested using the aforementioned test standards: the solid content of the obtained coating was 56%±1%, the adhesion of the water-based anti-corrosion coating was 2 MPa; the surface drying time of the coating obtained by spraying was 50 min, and the skinning test within 12 h was qualified; it passed the 50-h water resistance test; and it passed the 24-h neutral salt spray test.

[0090] Comparative Example 4 The method of Example 1 was followed, except that 2-amino-2-methyl-1-propanol was replaced with an equal number of 1-propanols, and the other conditions were the same as in Example 1.

[0091] The coating was tested using the aforementioned test standards: the solid content of the obtained coating was 56%±1%, the adhesion of the water-based anti-corrosion coating was 3 MPa; the surface drying time of the coating obtained by spraying was 15 min, and the skinning test within 12 h was qualified; it passed the water resistance test for 10 h; and it passed the neutral salt spray resistance test for 12 h.

[0092] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A water-based anti-corrosion coating, characterized in that, The coating comprises, by weight, the following components: Graphene 0.5-3 parts, matrix resin 5-40 parts, cobalt-free drying agent 0.01-0.1 parts, polyurethane thickener 0.2-0.8 parts, alkanolamine 0.1-0.8 parts, organosilicon dispersant 0.1-2 parts, inorganic filler 30-65 parts, water 20-50 parts.

2. The water-based anti-corrosion coating according to claim 1, wherein, 0.5-2 parts of graphene; and / or 15-35 parts of matrix resin; and / or 0.03-0.05 parts of cobalt-free drying agent; and / or 0.4-0.6 parts of polyurethane thickener; and / or 0.2-0.5 parts of alcoholamine; and / or 0.2-1 part of organosilicon dispersant; and / or 20-45 parts of inorganic filler; and / or 30-45 parts water.

3. The water-based anti-corrosion coating according to claim 1 or 2, wherein, The coating does not contain zinc or cobalt; and / or The solids content of the coating is 45wt%-65wt%.

4. The water-based anti-corrosion coating according to any one of claims 1-3, wherein, The cobalt-free drying agent contains vanadium; preferably, the vanadium content in the cobalt-free drying agent is not less than 2.5 wt%, and more preferably 5-7 wt%; and / or The alkanolamine is selected from one or more of 2-amino-2-methyl-1-propanol, ethanolamine, and butanolamine; and / or The polyurethane thickener has a viscosity of 5000-40000 mPa•s at 25°C, preferably 25000-40000 mPa•s; and / or The organosilicon dispersant has a viscosity of 50-100 mPa•s at 25°C. Preferably, the organosilicon dispersant is selected from one or more of Tego-270, Tego-260, Tego-280, Tego-500 and Tego-4000.

5. The water-based anti-corrosion coating according to any one of claims 1-4, wherein, The graphene has a carbon content of 85wt%-99.5wt%; and / or The D90 particle size of the graphene is 10-35 μm, preferably 15 μm-30 μm; and / or The matrix resin is selected from one or more of acrylic resins, alkyd resins and polyurethane resins, preferably alkyd resins.

6. The water-based anti-corrosion coating according to any one of claims 1-5, wherein, The inorganic filler is selected from one or more of the following: aluminum tripolyphosphate, barium sulfate, titanium dioxide, carbon black, calcium carbonate, flake glass, bentonite, talc, zinc oxide, mica powder, and mica iron oxide. The preferred inorganic packing material is selected from packing material 1 and packing material 2, wherein, Filler 1 is selected from one or more of aluminum tripolyphosphate, titanium dioxide, mica powder, and calcium carbonate; Filler 2 is selected from one or more of bentonite, talc, zinc oxide, barium sulfate, and carbon black; Preferably, packing 1 accounts for 60-80 wt% of the total weight of the inorganic packing, and packing 2 accounts for 20-40 wt% of the total weight of the inorganic packing.

7. The method for preparing the water-based anti-corrosion coating according to any one of claims 1-6, characterized in that, The method includes: mixing the components of the coating; Preferably, the preparation method includes: (1) Mix graphene, matrix resin, alkanolamine, polyurethane thickener, filler 1 and deionized water, perform first shear dispersion and first grinding; (2) The product of step (1) is mixed with filler 2, cobalt-free drying agent, organosilicon dispersant and deionized water, and then subjected to second shear dispersion and second grinding. Preferably, the first grinding conditions include: grinding to a fineness ≤25μm; a rotation speed of 400-600 rpm; a time of 30-60 min; and / or The second grinding conditions include: grinding to a fineness ≤30μm; rotation speed of 400-600 rpm; time of 15-30 min; and / or The first shearing conditions include: a rotation speed of 1200 rpm-1500 rpm; a time of 10-60 min; and / or The second shearing conditions include: a rotation speed of 800 rpm to 1500 rpm and a time of 10 to 30 minutes.

8. A water-based anti-corrosion coating, characterized in that, include: Graphene 0.5-3 parts, matrix resin 5-40 parts, cobalt-free drying agent 0.01-0.1 parts, polyurethane thickener 0.2-0.8 parts, alkanolamine 0.1-0.8 parts, organosilicon dispersant 0.1-2 parts, inorganic filler 30-65 parts; Preferably, The cobalt-free drying agent contains vanadium; preferably, the vanadium content in the cobalt-free drying agent is not less than 2.5 wt%; and / or The alkanolamine is selected from one or more of 2-amino-2-methyl-1-propanol, ethanolamine, and butanolamine; and / or The polyurethane thickener has a viscosity of 5000-40000 mPa•s at 25°C; and / or The viscosity of the organosilicon dispersant at 25°C is 50-100 mPa•s; and / or The matrix resin is selected from one or more of acrylic resins, alkyd resins, and polyurethane resins; and / or The inorganic filler is selected from one or more of the following: aluminum tripolyphosphate, barium sulfate, titanium dioxide, carbon black, calcium carbonate, flake glass, bentonite, talc, zinc oxide, mica powder, and mica iron oxide.

9. A water-based anti-corrosion coating, characterized in that, The water-based anti-corrosion coating is obtained by spraying, roller coating, brushing or dipping after mixing the components of the water-based anti-corrosion coating according to any one of claims 1-5. Preferably, the thickness of the water-based anti-corrosion coating is 30-300 μm; and / or The adhesion of the coating is ≥3MPa, preferably 4-6 MPa.

10. The application of the water-based anti-corrosion coating according to any one of claims 1-6 or the water-based anti-corrosion coating according to claim 8 or 9 in metal corrosion protection, preferably in the application of metal corrosion protection in the petroleum, chemical, power and electronics industries.