Water-based heavy-duty epoxy coating and preparation method thereof

Abstract

The invention discloses a waterborne epoxy coating for heavy corrosion prevention and a preparation method of the waterborne epoxy coating, and relates to the technical field of coatings. The waterborne epoxy resin, the waterborne epoxy curing agent, the titanium dioxide, the barium sulfate, the superfine talcum powder, the mica powder, the zinc phosphate, the aluminum tripolyphosphate, the superfine mica iron oxide, the glass flakes and the like are used as raw materials for preparing the epoxy coating. Meanwhile, the sheet structures of the superfine mica iron oxide and the glass flakes prolong the time for water and a corrosive medium to reach the surface of the base material, and sufficient dissociation time is given to phosphate. The anticorrosive paint disclosed by the invention has good flexibility and corrosion resistance.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and specifically to an epoxy coating for waterborne heavy corrosion protection and a preparation method thereof. Background Art

[0002] Corrosion is a phenomenon in which materials are damaged or deteriorated due to chemical, electrochemical or other reactions with the environment. According to statistics, the economic losses caused by corrosion worldwide each year account for 3% - 5% of the gross national product of each country, far greater than the total losses of natural disasters and various accidents. Improving the anti-corrosion technology level and reducing the corrosion cost have positive significance for the economic development of our country.

[0003] Among various anti-corrosion technologies, using anti-corrosion coatings for anti-corrosion is the most economical, practical and simple method. Current heavy anti-corrosion coatings are mainly oil-based organic or inorganic zinc-rich coatings. The difference between waterborne coatings and solvent-based coatings lies in safety and environmental protection. Solvent-based coatings have a high VOC content, generally exceeding 60%. Organic solvents are used as diluents and cleaning agents during construction, and there are potential safety hazards of flammability and explosion during transportation and storage. While waterborne coatings have a low VOC content, generally less than 10%, and can reduce emissions by 80% compared with solvent-based coatings. Water diluents and cleaning agents are used during construction, and there are no potential safety hazards of flammability and explosion during transportation and storage.

[0004] However, there is still a certain gap between waterborne coatings and solvent-based coatings in terms of performance. Currently, waterborne coatings cannot completely replace solvent-based coatings, and the corrosion resistance of waterborne coatings still needs to be improved. Based on this situation, the present application discloses an epoxy coating for waterborne heavy corrosion protection and a preparation method thereof to solve this technical problem. Summary of the Invention

[0005] The purpose of the present invention is to provide an epoxy coating for waterborne heavy corrosion protection and a preparation method thereof to solve the problems raised in the above background art.

[0006] To solve the above technical problems, the present invention provides the following technical solutions:

[0007] An epoxy coating for waterborne heavy corrosion protection, each component of the epoxy coating includes, by volume, 100 parts of waterborne epoxy resin, 20 - 30 parts of waterborne epoxy curing agent, 2 - 5 parts of titanium dioxide, 2 - 5 parts of barium sulfate, 1 - 2 parts of ultrafine talc powder, 3 - 7 parts of mica powder, 3 - 4 parts of zinc phosphate, 3 - 4 parts of aluminum tripolyphosphate, 3 - 4 parts of ultrafine mica iron oxide, 6 - 10 parts of glass flakes, 1 - 2 parts of dispersant, 0.3 - 1.2 parts of defoaming agent, 0.5 - 1 part of anti-flash rust additive, 3 - 8 parts of film-forming aid, 0.3 - 0.7 parts of wetting and leveling agent, 1 - 2 parts of rheological aid, and 60 - 80 parts of deionized water.

[0008] In a more optimized solution, the titanium dioxide is rutile titanium dioxide, the particle size of the barium sulfate is 1250 - 2500 mesh, and the particle size of the mica powder is 1250 - 2500 mesh; the particle size of the ultrafine talc powder is 2500 - 3000 mesh, and the particle size of the glass flake is 200 mesh.

[0009] The model of the ultrafine mica iron oxide is MIRCO30, provided by CEPHAS Company in the UK. This substance can be stacked layer by layer in the coating to form a multi-layer shielding layer, thus forming a maze effect and effectively reducing the infiltration of water and corrosive media.

[0010] In a more optimized solution, the surface of the glass flake is modified by γ-glycidoxypropyltrimethoxysilane. The specific steps are as follows: Immerse the glass flake in a sodium hydroxide solution for 30 - 40 minutes, wash, filter and dry, then transfer it to an ethanol aqueous solution of γ-glycidoxypropyltrimethoxysilane, stir and react for 4 - 6 hours, wash, filter and dry. The concentration of the sodium hydroxide solution is 3%; when preparing the ethanol aqueous solution, the volume ratio of ethanol to water is 5:1; the dosage of γ-glycidoxypropyltrimethoxysilane is 5 - 6 wt% of the mass of the glass flake.

[0011] In a more optimized solution, the volume ratio of zinc phosphate to aluminum tripolyphosphate is 1:1 or 2:1; the dispersant is a polyether-modified styrene-maleic anhydride copolymer or other polyether-modified copolymers; the leveling agent is a polyether siloxane type leveling agent BYK346; the film-forming auxiliary agent is alcohol ester twelve; the defoaming agent is any one or a compound of BYK022 and BYK024. Among them, BYK022 has slightly poor compatibility but good defoaming property, while BYK024 has slightly poor defoaming property but good compatibility. The most optimized solution is to select a compound of BYK022 and BYK024 as the defoaming agent, and the volume ratio is (1:1) - (2:1).

[0012] The model of the anti-flash rust additive is H14 (ASCOTEC Company in France), and its main component is an aqueous solution of organic acid salts and their derivatives, adding less than 5% of sodium nitrite. Because of its low nitrite content, it will not affect the overall water resistance of the coating; the waterborne epoxy curing agent is BSA-711H (Honglizhan Chemical Industry), which is a polyamine mixed modified type waterborne epoxy curing agent. The rheological additive is polyurea or a modified polyurea polymer BYK440.

[0013] In a more optimized solution, the epoxy coating further includes an epoxy monomer, and the dosage of the epoxy monomer accounts for 2 - 4 wt% of the mass of the waterborne epoxy resin; the preparation steps of the epoxy monomer are as follows:

[0014] S1: Mix protocatechuic acid and alkyl diol, dissolve them with dioxane as the solvent, then add a catalyst, which is p-toluenesulfonic acid, react at 110 - 120 °C for 6 - 7 h, wash and filter after the reaction to obtain polyphenol monomers;

[0015] S2: Mix the polyphenol monomers and epichlorohydrin, heat to 100 - 105 °C, stir until the polyphenol monomers are completely dissolved, then add tetrabutylammonium bromide, keep the temperature for reaction for 1 - 1.5 h, cool to 30 - 35 °C after the reaction, dropwise add sodium hydroxide solution to the system, continue to react for 1 - 1.5 h, remove epichlorohydrin by vacuum distillation after the reaction, purify and dry to obtain epoxy monomers.

[0016] In a more optimized scheme, in step S1, the molar ratio of protocatechuic acid to alkyl diol is 1:(2 - 2.1); the dosage of the catalyst is 1 - 1.5% of the molar amount of protocatechuic acid; in step S2, the molar ratio of the polyphenol monomers to epichlorohydrin is 1:(12 - 16); the dosage of tetrabutylammonium bromide is 0.5 - 1% of the molar amount of epichlorohydrin.

[0017] In a more optimized scheme, the epoxy coating further includes modified fluorinated graphene, and the dosage of the modified fluorinated graphene accounts for 1 - 3 wt% of the mass of the waterborne epoxy resin;

[0018] The preparation steps of the modified fluorinated graphene are as follows: Mix p-phenylenediamine and N,N-dimethylformamide, stir evenly, add epoxy monomers, react at 60 - 70 °C for 3 - 4 h, then add an ethanol solution of fluorinated graphene, ultrasonicate for 40 - 60 min, and react at 90 - 95 °C for 20 - 24 h to obtain modified fluorinated graphene.

[0019] In a more optimized scheme, the molar ratio of p-phenylenediamine to epoxy monomers is (1 - 2):1; the mass ratio of fluorinated graphene to p-phenylenediamine is 1:(10 - 15).

[0020] In a more optimized scheme, according to the preparation method of a waterborne heavy-duty anticorrosive epoxy coating described in any one of the above, the specific steps are as follows:

[0021] Step 1: Stir evenly the waterborne epoxy resin, dispersant, 1 / 2 dosage of defoamer, anti-flash rust agent and deionized water at a stirring speed of 500 - 1000 r / min for 15 - 30 min. Then add titanium dioxide, barium sulfate, ultrafine talc powder, mica powder, zinc sulfate, aluminum tripolyphosphate, ultrafine mica iron oxide and glass flakes, and disperse at a high speed for 20 - 30 min with a dispersion speed of 1500 - 2500 r / min. Transfer the well-dispersed mixed emulsion to a grinder, add a rheology aid, and grind for 0.5 - 1 h at a grinding speed of 2500 r / min - 3000 r / min. After grinding, add a film-forming aid, the remaining 1 / 2 dosage of defoamer and a wetting and leveling agent, and disperse at a speed of 500 - 1200 r / min for 20 - 30 min. After dispersion, filter to obtain Component A; the dosage of deionized water in Component A is 40 - 60 parts.

[0022] Step 2: Mix the waterborne epoxy curing agent and deionized water, and stir evenly to obtain Component B; the dosage of deionized water in Component B is 20 parts.

[0023] Step 3: Compound Component A and Component B to obtain an epoxy coating.

[0024] In a more optimized scheme, in Step 1, first mix the waterborne epoxy resin, modified fluorinated graphene and epoxy monomers, and then add other raw materials after mixing to obtain Component A.

[0025] Compared with the prior art, the beneficial effects achieved by the present invention are as follows:

[0026] The present invention discloses a waterborne heavy-duty anti-corrosion epoxy coating and its preparation method. The scheme adjusts the components and ratios of the coating. Using waterborne epoxy resin, waterborne epoxy curing agent, titanium dioxide, barium sulfate, ultrafine talc powder, mica powder, zinc phosphate, aluminum tripolyphosphate, ultrafine mica iron oxide, glass flakes and other components as raw materials to prepare an epoxy coating, the obtained epoxy coating film has good compactness. At the same time, the flaky structures of ultrafine mica iron oxide and glass flakes extend the time for water and corrosive media to reach the substrate surface, giving sufficient dissociation time for phosphates. The anti-corrosion coating of the present invention has good flexibility and corrosion resistance.

[0027] On this basis, this solution also introduces epoxy monomers and modified fluorinated graphene. The solution uses protocatechuic acid to react with alkyl diol, and hydroxyl groups are bonded to carboxyl groups to prepare polyphenol monomers containing multiple hydroxyl groups. Then, the polyphenol monomers and epichlorohydrin are epoxidized to generate epoxy monomers containing multiple epoxy groups. When this component is added to the epoxy coating, it can effectively improve the water resistance, corrosion resistance and other properties of the epoxy coating; and because the epoxy monomer contains a benzene ring, the toughness of the epoxy coating is also improved; at the same time, the solution uses p-phenylenediamine to react with the epoxy monomer, and bridges with p-phenylenediamine to graft the epoxy monomer onto the surface of fluorinated graphene. On the one hand, the dispersion performance of fluorinated graphene is improved, and it can participate in the system polymerization, and the density of the coating is increased; on the other hand, fluorinated graphene can fill the micropores generated during the curing of the epoxy coating, extend the transmission path of the corrosive medium, and greatly improve the corrosion resistance of the coating.

[0028] This solution discloses an epoxy coating for waterborne heavy corrosion protection and its preparation method. The solution adjusts the PVC (pigment volume concentration) ratio of the coating; the process design is reasonable, the proportion of each component is appropriate, and the prepared epoxy coating has excellent corrosion resistance, and the comprehensive performance is also very excellent, with high practicality. Detailed implementation mode

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0030] In the following examples, the surface of the glass flakes is modified by γ-glycidoxypropyltrimethoxysilane. The specific steps are as follows: Immerse the glass flakes in a sodium hydroxide solution for 40 minutes, wash, filter and dry, then transfer them to an ethanol aqueous solution of γ-glycidoxypropyltrimethoxysilane, stir and react for 6 hours, wash, filter and dry. The concentration of the sodium hydroxide solution is 3%; when preparing the ethanol aqueous solution, the volume ratio of ethanol to water is 5:1; the dosage of γ-glycidoxypropyltrimethoxysilane is 5wt% of the mass of the glass flakes.

[0031] In this example, the fluorinated graphene: the fluorine content is 56%, the purity is 99%, and it is provided by Shandong Chongshan Optoelectronic Materials Co., Ltd.

[0032] Example 1: A preparation method of an epoxy coating for waterborne heavy corrosion protection, the specific steps are as follows:

[0033] Step 1: Stir evenly the waterborne epoxy resin, dispersant, BYK022, anti-flash rust additive and deionized water at a stirring speed of 500 r / min for 30 min. Then add titanium dioxide, barium sulfate, ultrafine talc powder, mica powder, zinc sulfate, aluminum tripolyphosphate, ultrafine mica oxide and glass flakes, and disperse at a high speed of 2500 r / min for 20 min. Transfer the well-dispersed mixed emulsion to a grinding machine, add a rheology additive, and grind for 0.5 h at a grinding speed of 3000 r / min. After grinding, add a film-forming additive, BYK024 and a wetting and leveling agent, and disperse at a speed of 500 r / min for 30 min. After dispersion, filter to prepare Component A;

[0034] Step 2: Mix the waterborne epoxy curing agent and deionized water, and stir evenly to prepare Component B;

[0035] Step 3: Compound Component A and Component B to obtain an epoxy coating.

[0036] Example 2: A preparation method of a waterborne heavy-duty anti-corrosion epoxy coating, the specific steps are as follows:

[0037] Step 1: Stir evenly the waterborne epoxy resin, dispersant, BYK022, anti-flash rust additive and deionized water at a stirring speed of 800 r / min for 25 min. Then add titanium dioxide, barium sulfate, ultrafine talc powder, mica powder, zinc sulfate, aluminum tripolyphosphate, ultrafine mica oxide and glass flakes, and disperse at a high speed of 2000 r / min for 25 min. Transfer the well-dispersed mixed emulsion to a grinding machine, add a rheology additive, and grind for 1 h at a grinding speed of 2500 r / min. After grinding, add a film-forming additive, BYK024 and a wetting and leveling agent, and disperse at a speed of 1000 r / min for 25 min. After dispersion, filter to prepare Component A;

[0038] Step 2: Mix the waterborne epoxy curing agent and deionized water, and stir evenly to prepare Component B;

[0039] Step 3: Compound Component A and Component B to obtain an epoxy coating.

[0040] Example 3: A preparation method of a waterborne heavy-duty anti-corrosion epoxy coating, the specific steps are as follows:

[0041] Step 1: Stir the waterborne epoxy resin, dispersant, BYK022, anti-flash rust additive and deionized water evenly at a stirring speed of 1000 r / min for 15 min. Then add titanium dioxide, barium sulfate, ultrafine talc powder, mica powder, zinc sulfate, aluminum tripolyphosphate, ultrafine mica iron oxide and glass flakes, and disperse at a high speed of 1500 r / min for 30 min. Transfer the well-dispersed mixed emulsion to a grinding machine, add a rheology additive, and grind for 1 h at a grinding speed of 2500 r / min. After grinding, add a film-forming additive, BYK024 and a wetting and leveling agent, and disperse at a speed of 1200 r / min for 20 min. After dispersion, filter to prepare Component A;

[0042] Step 2: Mix the waterborne epoxy curing agent and deionized water evenly to prepare Component B;

[0043] Step 3: Compound Component A and Component B to obtain an epoxy coating.

[0044] Comparative Example 1: Comparative Example 1 is the control group of Example 3. Glass flakes and ultrafine mica iron oxide were not added in Comparative Example 1, and the dosages of other components were adjusted.

[0045] A preparation method of a waterborne heavy-duty anti-corrosion epoxy coating, the specific steps are as follows:

[0046] Step 1: Stir the waterborne epoxy resin, dispersant, BYK022, anti-flash rust additive and deionized water evenly at a stirring speed of 1000 r / min for 15 min. Then add titanium dioxide, barium sulfate, ultrafine talc powder, mica powder, zinc sulfate and aluminum tripolyphosphate, and disperse at a high speed of 1500 r / min for 30 min. Transfer the well-dispersed mixed emulsion to a grinding machine, add a rheology additive, and grind for 1 h at a grinding speed of 2500 r / min. After grinding, add a film-forming additive, BYK024 and a wetting and leveling agent, and disperse at a speed of 1200 r / min for 20 min. After dispersion, filter to prepare Component A;

[0047] Step 2: Mix the waterborne epoxy curing agent and deionized water evenly to prepare Component B;

[0048] Step 3: Compound Component A and Component B to obtain an epoxy coating.

[0049] Among them, the ingredient dosages (volume parts) of the epoxy coatings in Examples 1 to 3 are shown in Table 1 below:

[0050] Table 1

[0051]

[0052]

[0053] Example 4: Example 4 is based on Example 3, and an epoxy monomer and modified fluorinated graphene are added to the epoxy coating, wherein the dosage of the epoxy monomer accounts for 2.5 wt% of the mass of the waterborne epoxy resin; the dosage of the modified fluorinated graphene accounts for 2 wt% of the mass of the waterborne epoxy resin.

[0054] A preparation method of an epoxy coating for waterborne heavy corrosion protection, the specific steps are as follows:

[0055] Step 1: Mix the waterborne epoxy resin, epoxy monomer and modified fluorinated graphene, add a dispersant, BYK022, an anti-flash rust agent and deionized water and stir evenly. The stirring speed is 800 r / min and the stirring time is 25 min. Then add titanium dioxide, barium sulfate, ultrafine talc powder, mica powder, zinc sulfate, aluminum tripolyphosphate, ultrafine mica oxide and glass flakes, and disperse at a high speed for 25 min. The dispersion speed is 2000 r / min. Transfer the dispersed mixed emulsion to a grinding machine, add a rheology aid, and grind for 1 h. The grinding speed is 2500 r / min. After grinding, add a film-forming aid, BYK024 and a wetting and leveling agent, and disperse at a speed of 1000 r / min for 25 min. After dispersion, filter to prepare Component A;

[0056] Step 2: Mix the waterborne epoxy curing agent and deionized water, and stir evenly to prepare Component B;

[0057] Step 3: Compound Component A and Component B to obtain the epoxy coating.

[0058] The preparation steps of the epoxy monomer are as follows:

[0059] S1: Mix pyrocatechol and alkyl diol, dissolve with dioxane as a solvent, then add a catalyst, and react at 110 °C for 7 h. After the reaction, wash and filter to obtain a polyphenol monomer; the molar ratio of pyrocatechol to alkyl diol is 1:2.1; the catalyst is p-toluenesulfonic acid, and the dosage of the catalyst is 1.5% of the molar amount of pyrocatechol.

[0060] S2: Mix the polyphenol monomer and epichlorohydrin, heat to 100 °C, stir until the polyphenol monomer is completely dissolved, then add tetrabutylammonium bromide, keep the temperature and react for 1.5 h. After the reaction, cool to 30 °C, dropwise add the sodium hydroxide solution to the system, and continue to react for 1.5 h. After the reaction, distill off epichlorohydrin under reduced pressure, purify and dry to obtain the epoxy monomer. The molar ratio of the polyphenol monomer to epichlorohydrin is 1:16; the dosage of tetrabutylammonium bromide is 0.8% of the molar amount of epichlorohydrin. The concentration of sodium hydroxide is 30%.

[0061] The preparation steps of the modified fluorinated graphene are as follows: Mix p-phenylenediamine and N,N-dimethylformamide, stir evenly, add an epoxy monomer, react at 60 °C for 4 h, then add an ethanol solution of fluorinated graphene, ultrasonicate for 60 min, and react at 90 °C for 24 h to obtain the modified fluorinated graphene. The molar ratio of p-phenylenediamine to the epoxy monomer is 2:1; the mass ratio of fluorinated graphene to p-phenylenediamine is 1:14.

[0062] Example 5: Based on Example 3, an epoxy monomer and modified fluorinated graphene are added to the epoxy coating, wherein the dosage of the epoxy monomer accounts for 3.5 wt% of the mass of the waterborne epoxy resin; the dosage of the modified fluorinated graphene accounts for 2.5 wt% of the mass of the waterborne epoxy resin.

[0063] A preparation method of an epoxy coating for waterborne heavy corrosion protection, the specific steps are as follows:

[0064] Step 1: Mix the waterborne epoxy resin, epoxy monomer and modified fluorinated graphene, add a dispersant, BYK022, an anti-flash rust additive and deionized water, stir evenly, the stirring speed is 800 r / min, the stirring time is 25 min, then add titanium dioxide, barium sulfate, ultrafine talc powder, mica powder, zinc sulfate, aluminum tripolyphosphate, ultrafine mica oxide and glass flakes, disperse at a high speed for 25 min, the dispersion speed is 2000 r / min, transfer the dispersed mixed emulsion to a grinder, add a rheology additive, grind for 1 h, the grinding speed is 2500 r / min, after grinding is completed, add a film-forming additive, BYK024 and a wetting and leveling agent, the dispersion speed is 1000 r / min, the dispersion time is 25 min, and filter after dispersion is completed to prepare Component A;

[0065] Step 2: Mix the waterborne epoxy curing agent and deionized water, stir evenly to prepare Component B;

[0066] Step 3: Compound Component A and Component B to obtain the epoxy coating.

[0067] The preparation steps of the epoxy monomer are as follows:

[0068] S1: Mix pyrocatechol and alkyl diol, dissolve with dioxane as a solvent, then add a catalyst, react at 120 °C for 6 h, wash and filter after the reaction is completed to obtain a polyphenol monomer; the molar ratio of pyrocatechol to alkyl diol is 1:2.1; the catalyst is p-toluenesulfonic acid, and the dosage of the catalyst is 1.5% of the molar amount of pyrocatechol.

[0069] S2: Mix polyphenol monomers and epichlorohydrin, heat to 105 °C, stir until the polyphenol monomers are completely dissolved, then add tetrabutylammonium bromide, keep the temperature for reaction for 1 h, cool to 30 °C after the reaction, dropwise add the sodium hydroxide solution to the system, continue the reaction for 1.5 h, remove epichlorohydrin by vacuum distillation after the reaction is completed, purify and dry to obtain epoxy monomers. The molar ratio of the polyphenol monomers to epichlorohydrin is 1:16; the dosage of tetrabutylammonium bromide is 0.8% of the molar amount of epichlorohydrin. The concentration of sodium hydroxide is 30%.

[0070] The preparation steps of the modified fluorinated graphene are as follows: Mix p-phenylenediamine and N,N-dimethylformamide, stir evenly, add epoxy monomers, react at 70 °C for 3 h, then add the ethanol solution of fluorinated graphene, ultrasonicate for 60 min, and react at 95 °C for 20 h to obtain modified fluorinated graphene. The molar ratio of p-phenylenediamine to epoxy monomers is 2:1; the mass ratio of fluorinated graphene to p-phenylenediamine is 1:14.

[0071] Detection experiment:

[0072] 1. Take the epoxy coating samples prepared in Examples 1 to 3 and Comparative Example 1, and the coating thickness is 100 μm; the test standards are ISO4628-8 and GB-T1771-2007 "Determination of Resistance to Neutral Salt Spray of Paints and Varnishes", and the adhesion grade is tested by the cross-cut method. The test results are shown in Table 2 below:

[0073] Table 2

[0074]

[0075]

[0076] Conclusion: The present invention discloses a waterborne heavy-duty anticorrosive epoxy coating and its preparation method. The scheme adjusts the coating components and ratios, and uses waterborne epoxy resin, waterborne epoxy curing agent, titanium dioxide, barium sulfate, ultrafine talc powder, mica powder, zinc phosphate, aluminum tripolyphosphate, ultrafine mica iron oxide, glass flakes and other components as raw materials to prepare the epoxy coating. The obtained epoxy coating film has good compactness. At the same time, the flaky structures of ultrafine mica iron oxide and glass flakes prolong the time for water and corrosive media to reach the substrate surface, giving sufficient dissociation time for phosphates. The anticorrosive coating of the present invention has good flexibility and corrosion resistance.

[0077] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above-described exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-limiting. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, it is intended to embrace all changes that fall within the meaning and scope of the equivalent elements of the claims within the present invention.

Claims

1. A water-based heavy-duty anticorrosion epoxy coating, characterized in that: The components of the epoxy coating include, by volume, 100 parts of water-based epoxy resin, 20-30 parts of water-based epoxy curing agent, 2-5 parts of titanium dioxide, 2-5 parts of barium sulfate, 1-2 parts of ultrafine talc powder, 3-7 parts of mica powder, 3-4 parts of zinc phosphate, 3-4 parts of aluminum tripolyphosphate, 3-4 parts of ultrafine mica iron oxide, 6-10 parts of glass flakes, 1-2 parts of dispersant, 0.3-1.2 parts of defoaming agent, 0.5-1 part of anti-flash rust additive, 3-8 parts of film-forming additive, 0.3-0.7 part of wetting and leveling agent, 1-2 parts of rheological additive, and 60-80 parts of deionized water.

2. The water-based heavy-duty anticorrosion epoxy coating according to claim 1, characterized in that: The titanium dioxide is rutile titanium dioxide, the barium sulfate particle size is 1250-2500 mesh, the mica powder particle size is 1250-2500 mesh; the ultrafine talc powder particle size is 2500-3000 mesh, and the glass flake particle size is 200 mesh.

3. The water-based heavy-duty anticorrosion epoxy coating according to claim 1, characterized in that: The surface of the glass flakes is modified by γ-glycidyloxypropyltrimethoxysilane, and the specific steps are: soak the glass flakes in a sodium hydroxide solution for 30 to 40 minutes, wash, filter and dry, then transfer to an ethanol aqueous solution of γ-glycidyloxypropyltrimethoxysilane, stir and react for 4 to 6 hours, wash, filter and dry.

4. The water-based heavy-duty anticorrosion epoxy coating according to claim 1, characterized in that: The volume ratio of zinc phosphate to aluminum tripolyphosphate is 1:1 or 2:1; the dispersant is a polyether-modified styrene-maleic anhydride copolymer; the leveling agent is a polyether siloxane leveling agent; the film-forming aid is alcohol ester dodecahydrate; and the defoaming agent is any one of BYK022 and BYK024 or a combination of two thereof.

5. The water-based heavy-duty anticorrosion epoxy coating according to claim 1, characterized in that: The epoxy coating further comprises an epoxy monomer, the amount of which accounts for 2 to 4 wt% of the mass of the waterborne epoxy resin; the preparation steps of the epoxy monomer are as follows: S1: mixing protocatechuol and alkyl glycol, dissolving dioxane as a solvent, adding a catalyst, reacting at 110-120° C. for 6-7 hours, washing and filtering after the reaction, and obtaining a polyphenol monomer; S2: Mix polyphenol monomer and epichlorohydrin, heat to 100-105°C, stir until the polyphenol monomer is completely dissolved, add tetrabutylammonium bromide, keep warm and react for 1-1.5 hours, cool to 30-35°C after the reaction, add sodium hydroxide solution dropwise to the system, continue to react for 1-1.5 hours, remove epichlorohydrin by reduced pressure distillation after the reaction, purify, and dry to obtain epoxy monomer.

6. The water-based heavy-duty anticorrosion epoxy coating according to claim 5, characterized in that: In step S1, the molar ratio of protocatechuol to alkyl glycol is 1:(2-2.1); the catalyst is p-toluenesulfonic acid, and the amount of the catalyst used is 1-1.5% of the molar amount of protocatechuol; in step S2, the molar ratio of the polyphenol monomer to epichlorohydrin is 1:(12-16); the amount of tetrabutylammonium bromide used is 0.5-1% of the molar amount of epichlorohydrin.

7. The water-based heavy-duty anticorrosion epoxy coating according to claim 5, characterized in that: The epoxy coating further comprises modified fluorinated graphene, wherein the amount of the modified fluorinated graphene accounts for 1 to 3 wt% of the mass of the waterborne epoxy resin; The preparation steps of modified fluorinated graphene are as follows: p-phenylenediamine and N,N-dimethylformamide are mixed, stirred evenly, epoxy monomer is added, reacted at 60-70° C. for 3-4 hours, then an ethanol solution of fluorinated graphene is added, ultrasonicated for 40-60 minutes, and reacted at 90-95° C. for 20-24 hours to obtain modified fluorinated graphene.

8. The water-based heavy-duty anticorrosion epoxy coating according to claim 7, characterized in that: The molar ratio of the p-phenylenediamine to the epoxy monomer is (1-2):1; the mass ratio of the fluorinated graphene to p-phenylenediamine is 1:(10-15).

9. The method for preparing a water-based heavy-duty anticorrosive epoxy coating according to any one of claims 1 to 8, characterized in that: The specific steps are: Step 1: Stir the waterborne epoxy resin, dispersant, 1 / 2 amount of defoamer, anti-flash rust agent and deionized water evenly at a stirring speed of 500-1000r / min for 15-30min, then add titanium dioxide, barium sulfate, ultrafine talc, mica powder, zinc sulfate, aluminum tripolyphosphate, ultrafine mica oxide and glass flakes, disperse at high speed for 20-30min at a dispersion speed of 1500-2500r / min, transfer the dispersed mixed emulsion to a grinder, add a rheological agent, grind for 0.5-1h at a grinding speed of 2500r / min-3000r / min, add a film-forming agent, the remaining 1 / 2 amount of defoamer and a wetting and leveling agent after grinding, disperse at a speed of 500-1200r / min for 20-30min, filter after dispersion to prepare component A; Step 2: Mix the water-based epoxy curing agent and deionized water, stir evenly, and prepare component B; Step 3: Compound component A and component B to obtain epoxy coating.

10. The method for preparing a water-based heavy-duty anticorrosive epoxy coating according to claim 9, characterized in that: In step 1, water-based epoxy resin, modified fluorinated graphene and epoxy monomer are first mixed, and then other raw materials are added after mixing to prepare component A.

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