CN114933836A

CN114933836A - Environment-friendly long-acting anticorrosion water-based paint and preparation method thereof

Info

Publication number: CN114933836A
Application number: CN202210578807.8A
Authority: CN
Inventors: 梁的; 梁新方; 汪海涛; 伍小军
Original assignee: Baishikunyu Energy Technology Chengdu Co ltd
Current assignee: Baishikunyu Energy Technology Chengdu Co ltd
Priority date: 2022-05-25
Filing date: 2022-05-25
Publication date: 2022-08-23

Abstract

The invention discloses an environment-friendly long-acting anticorrosion water-based paint and a preparation method thereof, wherein the anticorrosion water-based paint mainly comprises the following raw materials: 36-45 parts of water dispersible epoxy resin, 2.4-2.7 parts of epoxy diluent, 7.5-8.2 parts of n-butyl alcohol, 26-29 parts of dimethylbenzene, 0.2-0.3 part of defoamer, 4-5 parts of bentonite, 24-30 parts of curing agent, 8-10 parts of filler, 3-12 parts of wetting agent, 12-15 parts of dispersant, 80-90 parts of zinc powder, 4-14 parts of antibacterial agent and 10-20 parts of water. Compared with the prior art, the long-acting anticorrosion water-based paint prepared by the formula has good hardness and ductility, and meanwhile, the storage stability and the anticorrosion effect are good.

Description

Environment-friendly long-acting anticorrosion water-based paint and preparation method thereof

Technical Field

The invention relates to the technical field of paint preparation, in particular to an environment-friendly long-acting anticorrosion water-based paint and a preparation method thereof.

Background

Metals play an important role in human life, but most of common metals are relatively active metals and are easy to generate chemical reaction or electrochemical reaction with surrounding media, so that the original properties of the metals are changed; this is referred to as metal corrosion. These corrosions can present a number of hazards. In some places with severe environments, metal corrosion is more likely to occur, for example, in marine engineering (offshore oil platforms, coastal facilities, etc.), transportation (ships, containers, etc.), urban facilities (natural gas pipelines, garbage disposal facilities, etc.), energy construction (oil storage facilities, hydraulic facilities, etc.), and the like. A large amount of money is invested each year in the maintenance of these devices. In order to reduce the economic loss caused by metal corrosion, people invent a plurality of anti-corrosion measures, such as electroplating, organic coating protection, current protection and the like, which can better protect the metal from being corroded. Experience has been accumulated by man over decades to find that applying a coating is the most economical and efficient method among these anti-corrosion measures.

However, during the construction and curing process, the coating material may volatilize organic solvent, which may cause environmental pollution and harm to the constructors and the body of the surrounding public. In order to solve the problem of environmental pollution caused by volatilization of organic solvents, the most mainstream measure at present is water-based coating, and the coating takes water as a solvent and almost has no pollution to the environment. The epoxy resin has the characteristics of excellent adhesive force, good corrosion resistance, small shrinkage after curing, low price and the like, and can be mixed with other resins, additives and pigments and fillers for use, so that the epoxy resin is widely applied to the field of coatings. Most of the commonly developed epoxy coatings are solvent-based, but due to the increasing awareness of the environmental protection and the implementation of government policies, the release of volatile organic compounds must be reduced in the coating industry, which results in the continuous shift of epoxy coatings from solvent-based coatings to waterborne coatings, and waterborne epoxy coatings are now used in many fields.

Although waterborne epoxy coatings have been developed rapidly and are widely used in many fields, they are still lacking in the field of metal corrosion protection, which is associated with the formation of a paint film of a waterborne coating: the formation of an aqueous film is a complex process consisting of three stages: particle packing, particle deformation and compaction, particle agglomeration. In the particle coalescence stage, molecular rearrangement occurs and polymer particles having similar polar groups tend to aggregate (which inevitably contain polar groups or hydrophilic groups in the aqueous epoxy coating), resulting in polar channels for water penetration by the polar groups in the particles, accelerating water absorption in the aqueous coating and reducing corrosion resistance. But the development of the waterborne epoxy anticorrosive paint is promoted due to the continuous development of the nano particles,

chinese patent CN 110607105A discloses a water-based nano silicon-acrylic metal anticorrosive paint and a preparation method thereof, and the paint raw material formula comprises the following components: 45-60% of a mixture compounded by epoxy groups and amino stoichiometric ratio of modified silicon dioxide nano particles and modified acrylic emulsion, 4-6% of a film-forming additive, 0.8-1.4% of a dispersing agent, 0.1-1.0% of a defoaming agent, 0.1-0.2% of a wetting agent, 0.05-0.10% of a mildew inhibitor, 1.5-2% of a flash rust inhibitor, 2-5% of a pigment, 15-30% of an antirust filler, 2-5% of a thickening agent, 1-2.5% of a salt fog resistant agent and the balance of water, and the coating has excellent corrosion resistance, better effects in the aspects of hardness and solvent resistance, better adhesive force and excellent mechanical and physical properties, unique wear resistance, and good salt fog resistance, water resistance and dry-wet alternation properties; chinese patent CN 112111200A discloses a preparation method of a high-temperature-resistant water-based heat-conducting anticorrosive coating, which comprises the following steps: weighing the following raw materials in parts by weight: 15-35 parts of modified carbon nano particles, 5-10 parts of anticorrosive filler, 75-90 parts of waterborne fluorocarbon resin, 3-8 parts of defoaming agent, 3-5 parts of curing agent and 150 parts of deionized water; adding the modified carbon nano particles into deionized water, ultrasonically oscillating and stirring for 15min to prepare a suspension, sequentially adding the suspension, the aqueous fluorocarbon resin, the defoaming agent and the curing agent into a ball mill, and performing ball milling for 2h to prepare the high-temperature-resistant aqueous heat-conducting anticorrosive coating; the prepared modified carbon nano particles can be stacked and connected with the macromolecular chain segment of the matrix, so that the density is increased, and the heat conductivity of the prepared coating is improved. In the prior art, a paint film added with nano-particle has excellent corrosion resistance, and a passivation film layer capable of blocking corrosive ion permeation is promoted to be formed on the surface of metal due to the existence of conductive polyaniline, but with the enhancement of environmental protection consciousness of people, the water-based paint is gradually developed towards the direction of being green and nontoxic to the environment, so that the water-based paint with good corrosion resistance, environmental protection and no toxicity needs to be prepared.

Disclosure of Invention

Aiming at the defects in the prior art, the invention aims to provide an environment-friendly long-acting anticorrosion water-based paint and a preparation method thereof.

An environment-friendly long-acting anticorrosion water-based paint comprises the following raw materials:

36-45 parts of water-dispersible epoxy resin, 2.4-2.7 parts of epoxy diluent, 7.5-8.2 parts of n-butyl alcohol, 26-29 parts of dimethylbenzene, 0.2-0.3 part of defoaming agent, 4-5 parts of bentonite, 24-30 parts of curing agent, 8-10 parts of filler, 3-12 parts of wetting agent, 12-15 parts of dispersing agent, 80-90 parts of zinc powder, 4-14 parts of antibacterial agent and 10-20 parts of water.

Further, the epoxy diluent is any one of propylene oxide propylene ether, butyl glycidyl ether or glycerol epoxy resin.

Further, the defoaming agent is a polysiloxane defoaming agent.

Further, the bentonite is tetraalkylammonium bentonite.

Further, the curing agent is a water-based isocyanate curing agent.

Further, the filler is one, two or more of mica powder, talcum powder and wollastonite.

Further, the wetting agent is any one of polyoxyethylene alkyl ether, polyether siloxane polymer or acetylene glycol polymer.

Further, the dispersing agent is at least one of modified siloxane, high-molecular carboxylic acid, polycarboxylate, sodium tripolyphosphate, sodium tetrapolyphosphate, sodium hexametaphosphate, sodium polyacrylate salt, acrylic acid, sodium sulfite and ethyl acetate.

Further, the antibacterial agent is polyhexamethylene biguanide.

With the continuous development of nano particles, the development of the water-based epoxy anticorrosive paint is gradually promoted. Research shows that the hexagonal boron nitride nanosheet with good dispersibility is introduced into a water-based epoxy resin system, so that the corrosion resistance of the matrix can be remarkably improved. This enhanced corrosion resistance is primarily due to the improved water resistance of the epoxy coating by the addition of the uniformly dispersed hexagonal boron nitride nanoplates. The nano iron oxide can also be used in the dispersed water-based epoxy acrylic paint, and a paint film of the prepared composite paint has excellent corrosion resistance, because the nano iron oxide is added, gaps can be filled, and corrosive media can be blocked; can effectively replace some harmful solvent-based coatings. In addition, the aqueous epoxy/polyaniline coating prepared by adding the conductive polyaniline nanoparticles into the aqueous epoxy coating has excellent corrosion resistance of a paint film, and a passivation film layer which can hinder the penetration of corrosive ions and is formed on the surface of metal is promoted due to the existence of the conductive polyaniline. The introduction of nano materials into waterborne epoxy coatings has become a main method for improving the corrosion resistance of waterborne epoxy coatings at present, so that the waterborne epoxy coatings not only have excellent corrosion resistance, but also have the performance of the added nano materials.

Further, the environment-friendly long-acting anticorrosion water-based paint comprises the following raw materials:

36-45 parts of water dispersible epoxy resin, 2.4-2.7 parts of epoxy diluent, 7.5-8.2 parts of n-butyl alcohol, 26-29 parts of dimethylbenzene, 0.2-0.3 part of defoaming agent, 4-5 parts of bentonite, 24-30 parts of curing agent, 8-10 parts of filler, 3-12 parts of wetting agent, 12-15 parts of dispersing agent, 80-90 parts of biochar composite zinc powder, 4-14 parts of antibacterial agent and 10-20 parts of water.

Currently, zinc-rich epoxy coatings have been used to protect steel structures from corrosion. It is generally recognized that zinc-rich epoxy coatings can provide current and barrier protection. In the initial stage of exposure, the sacrificial pigment is tightly connected, allowing the anodic current to flow down the steel substrate. The addition of zinc powder also requires carbon nanomaterials as carriers to prolong its corrosion protection, such as carbon nanotubes, carbon fibers, graphite, graphene and reduced graphene oxide, which provide excellent corrosion protection due to the additional conductive paths established with the zinc particles. However, the processing cost is expensive and the environment is easily affected to some extent, so that the carbon nano material which is more environment-friendly needs to be searched. In the prior art, graphene has obvious toxicity to human cells and organisms, and the life cycle energy consumption of the carbon nano tube is even higher than that of the traditional material such as aluminum. Biochar, a pyrolytic carbonaceous material, is obtained from the thermochemical processing of various bio-based feedstocks, such as wood and agricultural wastes. The carbon structure of biochar is electronically conductive, particularly when the biochar is produced under high temperature pyrolysis conditions. In consideration of the characteristics of high carbon content, large specific surface area, different functional group contents and the like, the biochar has the characteristics of environmental protection and more stable combination with zinc particles.

Biochar (biochar) is a charring product of organic matter. Various raw materials for preparing the biochar, such as agricultural wastes, such as rice straws, wheat straws, cotton straws, walnut shells, grass and the like; forestry wastes such as pine, palm wastes, etc.; livestock and poultry waste such as pig manure, cow manure and the like; municipal sewage sludge, and the like. If the solid waste generated in the industrial and agricultural production process cannot be effectively treated, not only can the waste of resources be caused, but also the environmental pollution and even the harm to human health can be caused. On the contrary, the organic solid residues with low water content are pyrolyzed to prepare the biochar, so that the pollution can be reduced, the resources can be comprehensively utilized, and the method has important significance.

The biochar composite zinc powder is prepared by the following method: cleaning spruce wood chips for 2-3 times by using tap water, naturally airing for 2-3 days, drying for 10-12 hours at 75-80 ℃, grinding until the particle size is 1-2 mm, placing the ground spruce wood powder in a crucible for compaction, wrapping two layers by using aluminum foil paper to isolate air, placing the spruce wood powder in a muffle furnace, and carbonizing for 3-4 hours at 500-600 ℃; after the temperature of the muffle furnace is reduced to room temperature, taking out the sample, continuously grinding, sieving with a 200-300-mesh sieve to obtain biochar, and then, according to the formula (2-4): 1, weighing the biochar and the zinc powder according to the proportion, and uniformly mixing to obtain the biochar composite zinc powder.

The invention also provides a preparation method of the environment-friendly long-acting anticorrosion water-based paint, which comprises the following steps:

s1, weighing water-dispersible epoxy resin, an epoxy diluent, n-butyl alcohol, xylene, a defoaming agent, a wetting agent, a dispersing agent and water according to the formula, mixing, and stirring at the rotating speed of 600-800 rpm for 15-20 min;

s2, adding bentonite, a curing agent, an antibacterial agent, a filler and a biochar composite zinc powder into the mixed slurry prepared in the step S1, and stirring for 75-80 min at the rotating speed of 2800-3200 rpm;

s3, filtering the paint prepared in the step S2 by 200-300 meshes of gauze to obtain the environment-friendly long-acting anticorrosion water-based paint.

According to the invention, the biochar composite zinc powder is added on the basis of the water-based epoxy coating, and compared with the traditional water-based epoxy coating, the connection of the zinc powder added independently is poor, and chloride ions and water molecules can easily bypass zinc particles and migrate to a steel matrix. The addition of irregularly shaped biochar creates multiple contact points between adjacent zinc, creating additional electron transfer paths for sacrificial protection. In addition, in the presence of the electrolyte, a galvanic cell is established with the remaining zinc as the anode and the adjacent carbon as the cathode, whereby the zinc is further oxidized and acts as a suppressor. Meanwhile, the ash content and functional groups provided by the alkaline environment promote the dissolution of zinc and the formation of corrosion products on the biochar, so that the corrosion resistance of the water-based epoxy coating is enhanced, and the technical effect of long-acting corrosion resistance is achieved.

Detailed Description

Partial raw material introduction in the examples:

waterborne epoxy resin EV-3075, available from Mobil chemical (Shanghai) Inc.;

butyl glycidyl ether, the content of epoxy resin reactive diluent 501 is 99 percent, and the butyl glycidyl ether is purchased from new material of Jinnan spring star, Co.Ltd;

a silicone aqueous defoaming agent SH-Y105 available from Larman reagents, Inc. of Shanghai family;

polyoxyethylene alkyl ether, CAS: 68439-51-0, available from alatin.

Tetraalkylammonium bentonite 827 with 250 meshes is purchased from Qinghong New Material Co., Ltd.

Waterborne isocyanate curing agent, WD-8100, available from Asahi Chemicals, east.

Polyhexamethylene biguanide, CAS: 32289-58-0, available from Nantong Runfeng petrochemical Co.

Mica powder, 1250 mesh, was purchased from Tenqiao sericite, Inc., Chuzhou.

Example 1

The preparation method of the environment-friendly long-acting anticorrosion water-based paint comprises the following steps:

s1, weighing and mixing water-based epoxy resin EV-307540 parts by weight, butyl glycidyl ether 2.6 parts by weight, n-butanol 8 parts by weight, xylene 27 parts by weight, polysiloxane defoamer 0.2 part by weight, polyoxyethylene alkyl ether 5.5 parts by weight, sodium hexametaphosphate 13 parts by weight and deionized water 13 parts by weight, and stirring for 15min at the rotating speed of 800 rpm;

s2, adding 4 parts by weight of tetraalkylammonium bentonite, 25 parts by weight of water-based isocyanate curing agent, 5 parts by weight of polyhexamethylene biguanide, 10 parts by weight of mica powder and 80 parts by weight of zinc powder into the mixed slurry prepared in the step S1, and stirring for 80min at the rotating speed of 3000 rpm;

s3, filtering the paint prepared in the step S2 by 300-mesh gauze to obtain the environment-friendly long-acting anticorrosion water-based paint.

Example 2

The preparation of the environment-friendly long-acting anticorrosive water-based paint comprises the following steps:

s2, adding 4 parts by weight of tetraalkylammonium bentonite, 25 parts by weight of water-based isocyanate curing agent, 5 parts by weight of polyhexamethylene biguanide, 10 parts by weight of mica powder and 80 parts by weight of biochar composite zinc powder into the mixed slurry prepared in the step S1, and stirring for 80min at the rotating speed of 3000 rpm;

The biochar composite zinc powder is prepared by the following method: the method comprises the following steps of cleaning spruce wood chips for 2 times by using tap water, naturally airing for 2 days, drying for 12 hours at 80 ℃, grinding until the particle size is 2mm, placing the ground wood chips in a crucible, compacting, wrapping two layers by using aluminum foil paper to isolate air, placing the wood chips in a muffle furnace, carbonizing for 3 hours at 550 ℃, taking out a sample after the temperature of the muffle furnace is reduced to room temperature, continuously grinding, sieving by using a 300-mesh sieve to obtain charcoal, and then, according to the formula 3: 1, weighing the biochar and the zinc powder according to the proportion, and uniformly mixing to obtain the biochar composite zinc powder.

Example 3

s1, weighing and mixing waterborne epoxy resin EV-307540 parts by weight, butyl glycidyl ether 2.6 parts by weight, n-butyl alcohol 8 parts by weight, xylene 27 parts by weight, polysiloxane defoamer 0.2 parts by weight, polyoxyethylene alkyl ether 5.5 parts by weight, sodium hexametaphosphate 13 parts by weight and deionized water 13 parts by weight, and stirring at the rotating speed of 800rpm for 15 min;

s2, adding 4 parts by weight of tetraalkylammonium bentonite, 25 parts by weight of water-based isocyanate curing agent, 5 parts by weight of polyhexamethylene biguanide, 10 parts by weight of mica powder and 80 parts by weight of modified charcoal composite zinc powder into the mixed slurry prepared in the step S1, and stirring for 80min at the rotating speed of 3000 rpm;

The modified biochar composite zinc powder is prepared by the following method: the method comprises the steps of firstly cleaning spruce wood chips with tap water for 2 times, naturally airing for 2 days, drying for 12 hours at 80 ℃, grinding until the particle size is 2mm, placing the ground wood chips in a crucible for compaction, wrapping two layers with aluminum foil paper to isolate air, placing the wood chips in a muffle furnace for carbonization for 3 hours at 550 ℃, taking out a sample after the temperature of the muffle furnace is reduced to room temperature, continuously grinding the sample, sieving the sample with a 300-mesh sieve to obtain biochar, assembling a three-neck flask and a spherical condenser tube from bottom to top, connecting a stirring device, connecting a rubber tube to a water tap, opening the water tap to enable water to slowly flow through the condenser tube, setting the temperature of an oil bath to be 120 ℃ for preheating, dissolving the biochar in 5mol/L NaOH solution, pouring the biochar into the flask together, and stirring for 48 hours at 400 r/min. And then washing the biomass by methanol for 3 times at 3500rpm by using a centrifugal machine, then drying the biomass in an oven at 75 ℃ for 6 hours to obtain modified charcoal, and then performing reaction according to the mass ratio of 3: 1, weighing the modified biological carbon and the zinc powder according to the proportion, and uniformly mixing to obtain the modified biological carbon composite zinc powder.

Comparative example 1

s2 adding 4 parts by weight of tetraalkylammonium bentonite, 25 parts by weight of aqueous isocyanate curing agent, 5 parts by weight of polyhexamethylene biguanide and 10 parts by weight of mica powder into the mixed slurry prepared in the step S1, and stirring for 80min at the rotating speed of 3000 rpm;

Test example 1

The environment-friendly long-acting anticorrosion water-based paint prepared in examples 1-3 and comparative example 1 is cured at normal temperature and subjected to hardness test after being dried for 7 days, the paint film hardness test is tested according to national standard GB/T6739-2006, and the hardness of the paint film is determined by using a pencil method. The test procedure was as follows:

(1) preparing 6B, 5B, 4B, 3B, 2B, B, HB, H, 2H, 3H, 4H, 5H and 6H pencils, cutting off 5-6 mm of each pencil by a knife, and grinding a ground pencil lead by No. 400 abrasive paper to ensure that the end surface is relatively flat but the edge is sharp;

(2) mounting the pencil on a hardness tester, and lightly placing the pencil on the surface of the coating to be tested;

(3) the two sides of the pulley are grasped by hands, and the pulley is pushed forwards at a certain slow speed, generally about 8mm, and can be pushed once, and cannot be pulled back and forth;

note that: starting with the pencil having the highest hardness, and then gradually decreasing the hardness of the replacement pencil, each pencil was scratched 3 times about 8mm long until the coating film was undamaged, and the hardness of the pencil, i.e., the hardness of the coating film, was measured, and the results are shown in table 1.

TABLE 1 hardness test result table for long-term corrosion-resistant water-based paint film

Examples	hardness/H
		Example 1	3
Example 2	4
		Example 3	5
Comparative example 1	2

As can be seen from Table 1, the addition of the biochar composite zinc powder increases the thickness of the long-acting anticorrosive water-based paint, the zinc powder coating has high hardness, the biochar addition provides a carrier for the zinc powder, and the processed biochar particles are mixed with the zinc powder to form a compact network structure, so that the hardness of the coating is further enhanced, and the service life of the paint is prolonged.

Test example 2

The environment-friendly long-acting anticorrosion water-based paint prepared in examples 1-3 and comparative example 1 is subjected to an anticorrosion test. Carrying out medium resistance test on the coating according to GB 9274-88; the method comprises the following specific steps: a paint film is prepared according to GB1727, after drying for 7d at normal temperature, the sample plates are edge-sealed by a mixture of paraffin and rosin in a ratio of 1:1, the edge-sealed width is about 2.5mm, and the three sample plates are put into a beaker filled with media (distilled water, 5 wt% sulfuric acid solution, 5 wt% sodium chloride solution and 5 wt% sodium hydroxide solution) and 2/3 is soaked in water. The panels were observed at intervals and the changes occurred were recorded.

TABLE 2 test result of dielectric resistance

As can be seen from table 2, the corrosion resistance of the coating becomes better after the zinc powder is added, and the zinc-rich epoxy coating can provide current and barrier protection. The addition of the zinc powder also needs a carbon nano material as a carrier to further prolong the anticorrosion effect of the coating, and for the traditional water-based epoxy coating, the connection of the singly added zinc powder is poor, and chloride ions and water molecules easily bypass zinc particles and migrate to a steel matrix. While the addition of irregularly shaped biochar creates multiple contact points between adjacent zinc, creating additional electron transfer paths for sacrificial protection. In addition, in the presence of the electrolyte, a galvanic cell is established with the remaining zinc as the anode and the adjacent carbon as the cathode, whereby the zinc is further oxidized and acts as a suppressor. Meanwhile, the ash component and the functional group provided by the alkaline environment promote the dissolution of zinc and the formation of corrosion products on the biochar, thereby enhancing the corrosion resistance of the water-based epoxy coating and achieving the technical effect of long-acting corrosion resistance. As can be seen from the comparison between the embodiment 2 and the embodiment 3, the biological carbon is subjected to modification treatment and then is hydroxylated, so that the connection between the biological carbon and the zinc powder is enhanced, and the anti-corrosion effect of the biological carbon composite zinc powder is further improved.

Test example 3

The storage stability test was performed on the environment-friendly long-acting anticorrosive water-based coating prepared in examples 1 to 3 and comparative example 1. According to the test according to GB 6753.3-1986, the steps are as follows:

(1) taking three glass bottles and respectively filling the component A until the sample is 1.5cm away from the bottle mouth;

(2) one sample is left, and the state of the component A in the detection bottle (dispersion condition of the pigment and filler) can be used for later comparison;

(3) sealing the two remaining bottles, weighing the mass of the two bottles by using an electronic balance, recording the mass, and putting the bottles into a constant-temperature drying oven at the set temperature of 50 +/-2 ℃ for 30 days;

(4) and (3) after placing for 30 days, taking out the sample from the constant-temperature drying oven, placing for 1d at normal temperature, weighing the sample by using an electronic balance, comparing the sample with the sample before storage, wherein if the error exceeds 1%, the measured result is possibly inaccurate and cannot be used as a final result, and the measured result is shown in table 3.

TABLE 3 storage stability test results table

Group of	Heat storage stability (30d)
		Example 1	8 (Settlement touch)
Example 2	8 (Settlement touch)
		Example 3	10 (complete suspension)
Comparative example 1	6 (knife face pushing with certain resistance)

As can be seen from Table 3, the thermal storage stability of the coating is not very good when zinc powder is added alone, but after the biochar is added, the zinc powder can be dispersed in the coating more uniformly and is not easy to agglomerate, so that the anti-settling purpose is achieved, and the thermal storage stability of the coating is improved.

Claims

1. The environment-friendly long-acting anticorrosion water-based paint is characterized by comprising the following raw materials in parts by weight: 36-45 parts of water-dispersible epoxy resin, 2.4-2.7 parts of epoxy diluent, 7.5-8.2 parts of n-butyl alcohol, 26-29 parts of dimethylbenzene, 0.2-0.3 part of defoamer, 4-5 parts of bentonite, 24-30 parts of curing agent, 8-10 parts of filler, 3-12 parts of wetting agent, 12-15 parts of dispersing agent, 80-90 parts of zinc powder, 4-14 parts of antibacterial agent and 10-20 parts of water.

2. The environment-friendly long-acting anticorrosion water-based paint is characterized by comprising the following raw materials in parts by weight: 36-45 parts of water dispersible epoxy resin, 2.4-2.7 parts of epoxy diluent, 7.5-8.2 parts of n-butyl alcohol, 26-29 parts of dimethylbenzene, 0.2-0.3 part of defoaming agent, 4-5 parts of bentonite, 24-30 parts of curing agent, 8-10 parts of filler, 3-12 parts of wetting agent, 12-15 parts of dispersing agent, 80-90 parts of biochar composite zinc powder, 4-14 parts of antibacterial agent and 10-20 parts of water.

3. The environment-friendly long-acting anticorrosive water-based coating as claimed in claim 1 or 2, characterized in that: the epoxy diluent is any one of propylene oxide propylene ether, butyl glycidyl ether or glycerol epoxy resin.

4. The environment-friendly long-acting anticorrosive water-based paint as claimed in claim 1 or 2, characterized in that: the defoaming agent is polysiloxane defoaming agent.

5. The environment-friendly long-acting anticorrosive water-based coating as claimed in claim 1 or 2, characterized in that: the bentonite is tetraalkylammonium bentonite; the curing agent is a water-based isocyanate curing agent.

6. The environment-friendly long-acting anticorrosive water-based coating as claimed in claim 1 or 2, characterized in that: the filler is one or a mixture of two or more of mica powder, talcum powder and wollastonite.

7. The environment-friendly long-acting anticorrosive water-based coating as claimed in claim 1 or 2, characterized in that: the wetting agent is any one of polyoxyethylene alkyl ether, polyether siloxane polymer or alkynediol polymer.

8. The environment-friendly long-acting anticorrosive water-based paint as claimed in claim 1 or 2, characterized in that: the dispersing agent is at least one of modified siloxane, high-molecular carboxylic acid, polycarboxylate, sodium tripolyphosphate, sodium tetrapolyphosphate, sodium hexametaphosphate, sodium polyacrylate, acrylic acid, sodium sulfite and ethyl acetate.

9. The environment-friendly long-acting anticorrosion water-based paint as claimed in claim 2, wherein the biochar composite zinc powder is prepared by the following method: cleaning spruce wood chips with tap water for 2-3 times, naturally airing for 2-3 days, drying for 10-12 hours at 75-80 ℃, grinding until the particle size is 1-2 mm, wrapping the ground wood chips with aluminum foil paper for two layers, putting the wrapped wood chips into a muffle furnace, carbonizing for 3-4 hours at 500-600 ℃, cooling, continuously grinding, sieving with a 200-300-mesh sieve to obtain charcoal, and then sieving according to the formula (2-4): 1, weighing the biochar and the zinc powder according to the proportion, and uniformly mixing to obtain the biochar composite zinc powder.

10. The preparation method of the environment-friendly long-acting anticorrosive water-based paint according to any one of claims 1 to 9, characterized by comprising the following steps:

s2, adding bentonite, a curing agent, an antibacterial agent, a filler and biochar composite zinc powder into the mixed slurry prepared in the step S1, and stirring for 75-80 min at the rotating speed of 2800-3200 rpm;

s3, filtering the paint prepared in the step S2 by gauze of 200-300 meshes to obtain the environment-friendly long-acting anticorrosion water-based paint.