阅读说明：本技术 一种超支化环氧富锌涂料及其制备方法 (Hyperbranched epoxy zinc-rich coating and preparation method thereof ) 是由 谢海 唐帆 于 2021-09-07 设计创作，主要内容包括：本发明属于涂料技术领域。本发明提供了一种超支化环氧富锌涂料,包含质量比为1～2:1的A组分和B组分；A组分包含如下质量份的组分：锌粉45～60份,固化剂8～15份,消泡剂0.1～0.3份,分散剂0.1～0.4份,填料0.5～2份,溶剂12～20份；B组分包含如下质量份的组分：有机硅改性环氧树脂乳液50～65份,聚苯胺接枝氧化石墨烯3～6份。本发明还提供了一种超支化环氧富锌涂料的制备方法。本发明的超支化环氧富锌涂料具有良好的柔韧性、附着力、耐盐雾性能、耐水性和耐冲击性,贮存稳定性和耐腐蚀性能显著提高,力学性能优异,使用寿命延长。(The invention belongs to the technical field of coatings. The invention provides a hyperbranched epoxy zinc-rich coating, which comprises a component A and a component B in a mass ratio of 1-2: 1; the component A comprises the following components in parts by mass: 45-60 parts of zinc powder, 8-15 parts of a curing agent, 0.1-0.3 part of a defoaming agent, 0.1-0.4 part of a dispersing agent, 0.5-2 parts of a filler and 12-20 parts of a solvent; the component B comprises the following components in parts by mass: 50-65 parts of organic silicon modified epoxy resin emulsion and 3-6 parts of polyaniline grafted graphene oxide. The invention also provides a preparation method of the hyperbranched epoxy zinc-rich coating. The hyperbranched epoxy zinc-rich coating has the advantages of good flexibility, adhesive force, salt spray resistance, water resistance and impact resistance, obviously improved storage stability and corrosion resistance, excellent mechanical property and prolonged service life.)

1. The hyperbranched epoxy zinc-rich coating is characterized by comprising a component A and a component B in a mass ratio of 1-2: 1;

the component A comprises the following components in parts by mass: 45-60 parts of zinc powder, 8-15 parts of a curing agent, 0.1-0.3 part of a defoaming agent, 0.1-0.4 part of a dispersing agent, 0.5-2 parts of a filler and 12-20 parts of a solvent;

the component B comprises the following components in parts by mass: 50-65 parts of organic silicon modified epoxy resin emulsion and 3-6 parts of polyaniline grafted graphene oxide.

2. The hyperbranched epoxy zinc-rich coating of claim 1, wherein the zinc powder is flake zinc powder and spherical zinc powder; the mass ratio of the flaky zinc powder to the spherical zinc powder is 2-3: 7-9; the particle size of the flaky zinc powder and that of the spherical zinc powder are independent and are 10-20 mu m.

3. The hyperbranched epoxy zinc-rich coating of claim 1 or 2, wherein the curing agent comprises one or more of diethylenetriamine, p-phenylenediamine, and triethylenetetramine; the defoaming agent is methyl silicone oil and/or polyether modified methyl siloxane.

4. The hyperbranched epoxy zinc-rich coating of claim 3, wherein the dispersant comprises one or more of sodium carboxylate, sodium polyacrylate, and ethylene bis stearamide; the filler comprises one or more of white corundum powder, aluminum titanate and diatomite powder, and the particle size of the filler is 0.5-3 mu m.

5. The hyperbranched epoxy zinc-rich coating of claim 4, wherein the solvent comprises N-methyl pyrrolidone and dipropylene glycol methyl ether in a volume ratio of 40-50: 10-15.

6. The hyperbranched epoxy zinc-rich coating as claimed in claim 4 or 5, wherein the preparation method of polyaniline grafted graphene oxide comprises the following steps:

1) performing grafting reaction on m-phenylenediamine and graphene oxide in an ethanol solution, and sequentially refining, washing and drying a grafting product to obtain the m-phenylenediamine grafted graphene oxide;

2) mixing m-phenylenediamine grafted graphene oxide, aniline, an ammonium persulfate solution and an ethanol solution for reaction, and sequentially refining, washing and drying reaction products to obtain the polyaniline grafted graphene oxide.

7. The hyperbranched epoxy zinc-rich paint of claim 6, wherein the mass-to-volume ratio of the m-phenylenediamine, the graphene oxide and the ethanol solution in the step 1) is 2-4 g: 0.1-0.5 g: 5-8 mL; the temperature of the grafting reaction is 75-90 ℃, and the time is 1-3 h; the mass fraction of the ethanol solution is 50-75%.

8. The hyperbranched epoxy zinc-rich paint of claim 7, wherein the mass-to-volume ratio of the aniline of step 2), the ammonium persulfate solution, the ethanol solution and the m-phenylenediamine of step 1) is 2-4 g: 2-4 mL: 5-8 mL: 2-4 g, wherein the reaction temperature is 1-10 ℃, and the reaction time is 6-9 h; the mass fraction of the ethanol solution is 50-75%, and the mass fraction of ammonium persulfate in the ammonium persulfate solution is 5-10%.

9. The preparation method of the hyperbranched epoxy zinc-rich paint as claimed in any one of claims 1 to 8, which comprises the following steps:

(1) mixing zinc powder, a curing agent, a defoaming agent, a dispersing agent, a filler and a solvent to obtain a component A;

(2) mixing the organic silicon modified epoxy resin emulsion and polyaniline grafted graphene oxide to obtain a component B;

(3) and mixing the component A and the component B to obtain the hyperbranched epoxy zinc-rich coating.

10. The method according to claim 9, wherein the mixing in step (1) is carried out at a rotation speed of 1500-2000 r/min for 15-20 min; the mixing time in the step (2) is 10-18 min, and the mixing is carried out at the rotating speed of 1500-2500 r/min; and (4) mixing for 5-10 min in the step (3), wherein the mixing is carried out at the rotating speed of 1800-2500 r/min.

Technical Field

The invention relates to the technical field of coatings, in particular to a hyperbranched epoxy zinc-rich coating and a preparation method thereof.

Background

The epoxy zinc-rich paint is a heavy-duty anticorrosive paint with excellent corrosion resistance, and is applied to various fields of industrial corrosion prevention. The corrosion prevention mechanism of the zinc-rich coating is mainly that zinc plays a role in cathodic protection, namely zinc powder is sacrificed in a corrosive environment to protect steel. In order to make the zinc-rich coating fully exert the cathode protection effect, a large amount of zinc powder is often added into the coating. However, the excessive content of zinc causes the increase of pores and poor flatness of the coating, and causes the reduction of the adhesive force, impact resistance and mechanical property of the coating, so that the coating falls off due to collision in the coating and using processes, and the protective effect on the base material is reduced.

The graphene has a lamellar structure and a large specific surface area, and a compact protective film can be formed between laminas due to the existence of conjugated chemical bonds, so that the graphene has a good physical shielding effect on diffusion of water, oxygen, ions and the like, and the corrosion resistance of a metal material can be enhanced. The graphene also has good flexibility, and can improve the impact resistance and mechanical properties of the coating. However, graphene as an inert material has limited compatibility with organic resin, which limits the application of graphene in epoxy zinc-rich paint; the density difference between the zinc powder and the graphene oxide is large, so that the graphene oxide is easily distributed in a gradient manner in a coating structure, the adhesive force of the coating is reduced, and the water-resistant permeability and the corrosion resistance of the coating are affected.

Therefore, the research and development of the epoxy zinc-rich coating which has good dispersion uniformity and can simultaneously improve the corrosion resistance, the water penetration resistance, the mechanical property and the adhesive force has important value and significance.

Disclosure of Invention

The invention aims to provide a hyperbranched epoxy zinc-rich coating and a preparation method thereof aiming at the defects of the prior art. The hyperbranched epoxy zinc-rich coating has no bubbling, no wrinkling, no falling and no rustiness for 1450h in water, the salt spray resistance time is more than or equal to 2500h, the flexibility is less than or equal to 1mm, and the impact resistance is more than or equal to 70 cm.

In order to achieve the above object, the present invention provides the following technical solutions:

the invention provides a hyperbranched epoxy zinc-rich coating, which comprises a component A and a component B in a mass ratio of 1-2: 1;

the component A comprises the following components in parts by mass: 45-60 parts of zinc powder, 8-15 parts of a curing agent, 0.1-0.3 part of a defoaming agent, 0.1-0.4 part of a dispersing agent, 0.5-2 parts of a filler and 12-20 parts of a solvent;

the component B comprises the following components in parts by mass: 50-65 parts of organic silicon modified epoxy resin emulsion and 3-6 parts of polyaniline grafted graphene oxide.

Preferably, the zinc powder is flake zinc powder and spherical zinc powder; the mass ratio of the flaky zinc powder to the spherical zinc powder is 2-3: 7-9; the particle size of the flaky zinc powder and that of the spherical zinc powder are independent and are 10-20 mu m.

Preferably, the curing agent comprises one or more of diethylenetriamine, p-phenylenediamine and triethylene tetramine; the defoaming agent is methyl silicone oil and/or polyether modified methyl siloxane.

Preferably, the dispersing agent comprises one or more of sodium carboxylate, sodium polyacrylate and ethylene bis stearamide; the filler comprises one or more of white corundum powder, aluminum titanate and diatomite powder, and the particle size of the filler is 0.5-3 mu m.

Preferably, the solvent comprises N-methyl pyrrolidone and dipropylene glycol methyl ether in a volume ratio of 40-50: 10-15.

Preferably, the preparation method of the polyaniline grafted graphene oxide comprises the following steps:

1) performing grafting reaction on m-phenylenediamine and graphene oxide in an ethanol solution, and sequentially refining, washing and drying a grafting product to obtain the m-phenylenediamine grafted graphene oxide;

2) mixing m-phenylenediamine grafted graphene oxide, aniline, an ammonium persulfate solution and an ethanol solution for reaction, and sequentially refining, washing and drying reaction products to obtain the polyaniline grafted graphene oxide.

Preferably, the mass volume ratio of the m-phenylenediamine, the graphene oxide and the ethanol solution in the step 1) is 2-4 g: 0.1-0.5 g: 5-8 mL; the temperature of the grafting reaction is 75-90 ℃, and the time is 1-3 h; the mass fraction of the ethanol solution is 50-75%.

Preferably, the mass volume ratio of the aniline in the step 2), the ammonium persulfate solution, the ethanol solution and the m-phenylenediamine in the step 1) is 2-4 g: 2-4 mL: 5-8 mL: 2-4 g, wherein the reaction temperature is 1-10 ℃, and the reaction time is 6-9 h; the mass fraction of the ethanol solution is 50-75%, and the mass fraction of ammonium persulfate in the ammonium persulfate solution is 5-10%.

The invention also provides a preparation method of the hyperbranched epoxy zinc-rich coating, which comprises the following steps:

(1) mixing zinc powder, a curing agent, a defoaming agent, a dispersing agent, a filler and a solvent to obtain a component A;

(2) mixing the organic silicon modified epoxy resin emulsion and polyaniline grafted graphene oxide to obtain a component B;

(3) and mixing the component A and the component B to obtain the hyperbranched epoxy zinc-rich coating.

Preferably, the mixing time in the step (1) is 15-20 min, and the mixing is carried out at the rotating speed of 1500-2000 r/min; the mixing time in the step (2) is 10-18 min, and the mixing is carried out at the rotating speed of 1500-2500 r/min; and (4) mixing for 5-10 min in the step (3), wherein the mixing is carried out at the rotating speed of 1800-2500 r/min.

The beneficial effects of the invention include the following:

1) the hyperbranched epoxy zinc-rich paint disclosed by the invention has the advantages that the using amount of zinc powder is reduced, the VOC content is low, the paint is green and environment-friendly, no pollution is caused, and the production cost is reduced.

2) The hyperbranched epoxy zinc-rich coating has the advantages of good flexibility, adhesive force, salt spray resistance, water resistance and impact resistance, obviously improved storage stability and corrosion resistance, excellent mechanical property and prolonged service life.

Detailed Description

The invention provides a hyperbranched epoxy zinc-rich coating, which comprises a component A and a component B in a mass ratio of 1-2: 1;

the component A comprises the following components in parts by mass: 45-60 parts of zinc powder, 8-15 parts of a curing agent, 0.1-0.3 part of a defoaming agent, 0.1-0.4 part of a dispersing agent, 0.5-2 parts of a filler and 12-20 parts of a solvent;

the component B comprises the following components in parts by mass: 50-65 parts of organic silicon modified epoxy resin emulsion and 3-6 parts of polyaniline grafted graphene oxide.

In the hyperbranched epoxy zinc-rich coating, the mass ratio of the component A to the component B is preferably 1.2-1.7: 1, and more preferably 1.5: 1.

The component A comprises 45-60 parts of zinc powder, preferably 50-56 parts, and more preferably 52-54 parts.

The zinc powder of the present invention is preferably a flaky zinc powder and a spherical zinc powder; the mass ratio of the flaky zinc powder to the spherical zinc powder is preferably 2-3: 7-9, and more preferably 2.5: 8; the particle size of the flaky zinc powder and the particle size of the spherical zinc powder are independent, preferably 10-20 mu m, more preferably 12-18 mu m, and even more preferably 14-16 mu m.

The component A comprises 8-15 parts of a curing agent, preferably 10-13 parts, and more preferably 11-12 parts; the curing agent preferably comprises one or more of diethylenetriamine, p-phenylenediamine and triethylene tetramine; when the curing agent contains several components at the same time, the components are preferably mixed in an equal mass ratio.

The curing agent disclosed by the invention is good in heat resistance, and small in mass loss rate and hardness change at high temperature.

The component A comprises 0.1-0.3 part of defoaming agent, preferably 0.2 part; the defoaming agent is preferably methyl silicone oil and/or polyether-modified methyl siloxane, and when the defoaming agent contains both methyl silicone oil and polyether-modified methyl siloxane, the two are preferably mixed in an equal mass ratio.

The component A comprises 0.1-0.4 part of dispersant, preferably 0.2-0.3 part; the dispersing agent preferably comprises one or more of sodium carboxylate, sodium polyacrylate and ethylene bis stearamide; when the dispersant contains several components at the same time, the components are preferably mixed in an equal mass ratio.

The component A comprises 0.5-2 parts of filler, preferably 0.8-1.6 parts, and further preferably 1-1.3 parts; the filler preferably comprises one or more of white corundum powder, aluminum titanate and diatomite powder, and when the filler simultaneously comprises a plurality of components, the components are preferably mixed in equal mass ratio; the particle size of the filler is preferably 0.5-3 μm, more preferably 1-2.5 μm, and even more preferably 1.5-2 μm.

The filler of the invention can improve the compactness of the epoxy zinc-rich coating, so that the coating has higher hardness and mechanical property, and the filling property and the fluidity of the coating are enhanced.

The component A comprises 12-20 parts of solvent, preferably 14-18 parts, and more preferably 15-16 parts; the solvent preferably comprises N-methyl pyrrolidone and dipropylene glycol methyl ether, and the volume ratio of the N-methyl pyrrolidone to the dipropylene glycol methyl ether is preferably 40-50: 10-15, more preferably 42-48: 11-14, and even more preferably 44-46: 12-13.

The solvent provided by the invention can fully dissolve zinc powder, curing agent, filler and polyaniline grafted graphene oxide, effectively improves the dispersion uniformity of the epoxy zinc-rich coating, and is beneficial to improving the anti-corrosion performance and mechanical property of the coating.

The component B comprises 50-65 parts of organic silicon modified epoxy resin emulsion, preferably 54-62 parts, and more preferably 58-60 parts.

The organic silicon modified epoxy resin emulsion and the polyaniline grafted graphene oxide form stronger acting force, have good dispersibility in the coating, and obviously improve the water permeability resistance, the salt spray resistance and the adhesive force of the coating.

The component B comprises 3-6 parts of polyaniline grafted graphene oxide, preferably 4-5 parts, and more preferably 4.5 parts.

The polyaniline grafted graphene oxide has the advantages of high specific surface area, good gas isolation performance and adsorption performance and high mechanical strength, the polyaniline can improve the dispersibility of the graphene in the coating and reduce the agglomeration phenomenon, and the corrosion resistance, flexibility and impact strength of the coating can be improved under the combined action of the polyaniline grafted graphene oxide, the organic silicon modified epoxy resin emulsion and zinc powder; the using amount of zinc powder can be reduced, and the cost is saved.

The preparation method of the polyaniline grafted graphene oxide preferably comprises the following steps:

1) performing grafting reaction on m-phenylenediamine and graphene oxide in an ethanol solution, and sequentially refining, washing and drying a grafting product to obtain the m-phenylenediamine grafted graphene oxide;

2) mixing m-phenylenediamine grafted graphene oxide, aniline, an ammonium persulfate solution and an ethanol solution for reaction, and sequentially refining, washing and drying reaction products to obtain the polyaniline grafted graphene oxide.

The mass-volume ratio of the m-phenylenediamine, the graphene oxide and the ethanol solution in the step 1) is preferably 2-4 g: 0.1-0.5 g: 5-8 mL, more preferably 3 g: 0.2-0.4 g: 6-7 mL, more preferably 3 g: 0.3 g: 6.5 mL.

The m-phenylenediamine has large steric hindrance, and can effectively improve the agglomeration problem of the graphene oxide; two amido groups on the m-phenylenediamine molecule are respectively bonded with epoxy groups of the graphene oxide and the organic silicon modified epoxy resin, so that the compatibility between the graphene oxide and the epoxy resin is improved.

Before the grafting reaction in the step 1), m-phenylenediamine and an ethanol solution are preferably uniformly mixed and then mixed with graphene oxide; the temperature of the grafting reaction is preferably 75-90 ℃, more preferably 78-86 ℃, and even more preferably 80-82 ℃; the time of the grafting reaction is preferably 1-3 h, and further preferably 2 h; the mass fraction of the ethanol solution is preferably 50-75%, more preferably 55-70%, and even more preferably 60-65%.

The grain diameter after thinning in the step 1) is preferably 0.3-0.5 mu m; the washing reagent is preferably absolute ethyl alcohol, and the washing times are preferably 2-3 times; the temperature of the drying treatment is preferably 70-80 ℃, and further preferably 75 ℃; the time is preferably 4 to 6 hours, and more preferably 5 hours.

The mass-volume ratio of the aniline in the step 2) to the ammonium persulfate solution to the ethanol solution in the step 1) is preferably 2-4 g: 2-4 mL: 5-8 mL: 2-4 g, more preferably 2.5-3.5 g: 2.5-3.5 mL: 6-7 mL: 2.5-3.5 g, more preferably 3 g: 3mL of: 6.5 mL: 3g of the total weight of the mixture;

in the mixing in the step 2), m-phenylenediamine grafted graphene oxide and an ethanol solution are preferably uniformly mixed, then mixed with aniline, and finally mixed with an ammonium persulfate solution; the reaction temperature is preferably 1-10 ℃, more preferably 3-8 ℃, and more preferably 5-6 ℃; the reaction time is preferably 6-9 h, and more preferably 7-8 h; the mass fraction of the ethanol solution is preferably 50-75%, more preferably 55-70%, and even more preferably 60-65%; in the ammonium persulfate solution, the mass fraction of ammonium persulfate is preferably 5-10%, and more preferably 6-8%.

The grain diameter after thinning in the step 2) of the invention is preferably 0.3-0.5 μm; the washing reagent is preferably absolute ethyl alcohol, and the washing times are preferably 2-3 times; the temperature of the drying treatment is preferably 70-80 ℃, and further preferably 75 ℃; the time is preferably 4 to 6 hours, and more preferably 5 hours.

The invention also provides a preparation method of the hyperbranched epoxy zinc-rich coating, which comprises the following steps:

(1) mixing zinc powder, a curing agent, a defoaming agent, a dispersing agent, a filler and a solvent to obtain a component A;

(2) mixing the organic silicon modified epoxy resin emulsion and polyaniline grafted graphene oxide to obtain a component B;

(3) and mixing the component A and the component B to obtain the hyperbranched epoxy zinc-rich coating.

The mixing time in the step (1) of the invention is preferably 15-20 min, more preferably 16-19 min, and even more preferably 17-18 min; the mixing is preferably carried out at a rotating speed of 1500-2000 r/min, and more preferably 1600-1800 r/min; the mixing time in the step (2) is preferably 10-18 min, more preferably 12-16 min, and even more preferably 14-15 min; the mixing is preferably carried out at a rotating speed of 1500-2500 r/min, more preferably 1700-2200 r/min, and even more preferably 2000 r/min; the mixing time in the step (3) is preferably 5-10 min, and more preferably 6-8 min; the mixing is preferably carried out at a rotational speed of 1800 to 2500r/min, more preferably 2000 to 2200 r/min.

The technical solutions provided by the present invention are described in detail below with reference to examples, but they should not be construed as limiting the scope of the present invention.

Example 1

2kg of m-phenylenediamine is uniformly mixed in 5L of ethanol solution (the mass fraction is 55 percent), 0.1kg of graphene oxide is added, and grafting reaction is carried out for 3h at 78 ℃ after full mixing. And screening the obtained grafting product to obtain powder with the particle size of 0.48 mu m, washing the powder for 2 times by using absolute ethyl alcohol, and drying the powder at 72 ℃ for 6 hours to obtain the m-phenylenediamine grafted graphene oxide. Uniformly mixing m-phenylenediamine grafted graphene oxide in 6L of ethanol solution (the mass fraction is 55%), adding 2kg of aniline, finally adding 2L of ammonium persulfate solution (the mass fraction of ammonium persulfate is 6%), reacting for 8h at 6 ℃, screening the product after the reaction is finished to obtain powder with the particle size of 0.46 mu m, washing for 2 times by using absolute ethyl alcohol, and drying at 72 ℃ for 6h to obtain the polyaniline grafted graphene oxide.

1kg of a flaky zinc powder (particle size of 10 μm), 3kg of a spherical zinc powder (particle size of 10 μm), 0.9kg of diethylenetriamine, 0.01kg of methyl silicone oil, 0.01kg of sodium carboxylate, 0.06kg of diatomaceous earth powder (particle size of 0.8 μm), and 1.2kg of a solvent (a mixed solution of N-methylpyrrolidone and dipropylene glycol methyl ether in a volume ratio of 42: 12) were mixed at a rotation speed of 1600r/min for 20min to obtain component A. 5.2kg of organic silicon modified epoxy resin emulsion and 0.35kg of polyaniline grafted graphene oxide are mixed for 18min at the rotating speed of 1600r/min to obtain a component B. And mixing the component A and the component B at the rotating speed of 1800r/min for 10min to obtain the hyperbranched epoxy zinc-rich coating.

Example 2

3.8kg of m-phenylenediamine is uniformly mixed in 7.8L of ethanol solution (the mass fraction is 70 percent), 0.45kg of graphene oxide is added, and grafting reaction is carried out for 1h at 88 ℃ after full mixing. And screening the obtained grafting product to obtain powder with the particle size of 0.32 mu m, washing the powder for 3 times by using absolute ethyl alcohol, and drying the powder at 78 ℃ for 4 hours to obtain the m-phenylenediamine grafted graphene oxide. Uniformly mixing m-phenylenediamine grafted graphene oxide in 8L of ethanol solution (the mass fraction is 70%), adding 4kg of aniline, finally adding 4L of ammonium persulfate solution (the mass fraction of ammonium persulfate is 9%), reacting at 1 ℃ for 6h, screening the product after the reaction is finished to obtain powder with the particle size of 0.32 mu m, washing for 3 times by using absolute ethyl alcohol, and drying at 78 ℃ for 4h to obtain the polyaniline grafted graphene oxide.

1.2kg of a flaky zinc powder (particle size: 18 μm), 4.8kg of a spherical zinc powder (particle size: 18 μm), 0.7kg of p-phenylenediamine, 0.7kg of triethylenetetramine, 0.03kg of polyether-modified methylsiloxane, 0.04kg of ethylene bis-stearamide, 0.2kg of aluminum titanate (particle size: 2.8 μm), and 2kg of a solvent (a mixed solution of N-methylpyrrolidone and dipropylene glycol methyl ether at a volume ratio of 48: 14) were mixed at a rotation speed of 2000r/min for 15min to obtain component A. And mixing 6.3kg of organic silicon modified epoxy resin emulsion and 0.55kg of polyaniline grafted graphene oxide for 10min at the rotating speed of 2300r/min to obtain the component B. And mixing the component A and the component B for 5min at the rotating speed of 2500r/min to obtain the hyperbranched epoxy zinc-rich coating.

Example 3

3kg of m-phenylenediamine is uniformly mixed in 6L of ethanol solution (the mass fraction is 60 percent), 0.35kg of graphene oxide is added, and grafting reaction is carried out for 2h at 82 ℃ after full mixing. And screening the obtained grafting product to obtain powder with the particle size of 0.4 mu m, washing the powder for 3 times by using absolute ethyl alcohol, and drying the powder at the temperature of 75 ℃ for 5 hours to obtain the m-phenylenediamine grafted graphene oxide. Uniformly mixing m-phenylenediamine grafted graphene oxide in 6L of ethanol solution (the mass fraction is 60%), adding 3kg of aniline, finally adding 6L of ammonium persulfate solution (the mass fraction of ammonium persulfate is 8%), reacting at 3 ℃ for 8h, screening the product after the reaction is finished to obtain powder with the particle size of 0.4 mu m, washing for 3 times by using absolute ethyl alcohol, and drying at 75 ℃ for 5h to obtain the polyaniline grafted graphene oxide.

1.3kg of a flaky zinc powder (particle size 15 μm), 3.9kg of a spherical zinc powder (particle size 15 μm), 1.2kg of triethylene tetramine, 0.02kg of polyether modified methyl siloxane, 0.03kg of sodium polyacrylate, 0.12kg of white corundum powder (particle size 1.5 μm) and 1.5kg of a solvent (a mixed solution of N-methyl pyrrolidone and dipropylene glycol methyl ether in a volume ratio of 45: 12) were mixed at a rotation speed of 1800r/min for 16min to obtain a component A.

5.8kg of organic silicon modified epoxy resin emulsion and 0.45kg of polyaniline grafted graphene oxide are mixed for 15min at the rotating speed of 2000r/min to obtain a component B. And mixing the component A and the component B for 7min at the rotating speed of 2200r/min to obtain the hyperbranched epoxy zinc-rich coating.

Comparative example 1

The m-phenylenediamine-grafted graphene oxide in example 3 was replaced with polyethyleneimine-grafted modified graphene oxide of the same mass, and the other conditions were the same as in example 3.

Comparative example 2

The white corundum powder and triethylene tetramine of example 3 were replaced with kaolin and polyamide curing agents of the same mass, respectively, and the other conditions were the same as in example 3.

Comparative example 3

The solvent used was a mixture of xylene and butanol at a volume ratio of 4:1 without adding polyether-modified methylsiloxane, and the other conditions were the same as in example 3.

The epoxy zinc-rich coatings of examples 1 to 3 and comparative examples 1 to 3 were tested for adhesion, salt spray resistance, water resistance, flexibility, impact resistance, and Volatile Organic Compound (VOC) content, and the results are shown in Table 1.

TABLE 1 test results of epoxy zinc-rich coatings of different examples and comparative examples

As shown in Table 1, the hyperbranched epoxy zinc-rich paint provided by the invention has good flexibility, adhesion, salt spray resistance, water resistance and impact resistance, and is low in VOC content. The hyperbranched epoxy zinc-rich coating has the advantages of obviously improved storage stability and corrosion resistance, excellent mechanical property and prolonged service life; the hyperbranched epoxy zinc-rich coating has no bubbling, no wrinkling, no shedding and no rustiness for 1450h in water, the salt spray resistance time is more than or equal to 2500h, the flexibility is less than or equal to 1mm, and the impact resistance is more than or equal to 70 cm.

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.