CN112876927A

CN112876927A - Corrosion-resistant water-based amino baking paint and preparation method thereof

Info

Publication number: CN112876927A
Application number: CN202110201638.1A
Authority: CN
Inventors: 郑玉婴; 杨文杰
Original assignee: Fuzhou University
Current assignee: Fuzhou University
Priority date: 2021-02-23
Filing date: 2021-02-23
Publication date: 2021-06-01
Anticipated expiration: 2041-02-23
Also published as: CN112876927B

Abstract

The invention belongs to the technical field of water-based paint, and particularly relates to corrosion-resistant water-based amino baking paint and a preparation method thereof. Firstly, preparing graphene oxide GO by adopting an improved Hummers method, then obtaining redox graphene rGO by using glucose as a reducing agent, sulfonating the rGO by using a diazonium salt solution with a sulfonic acid group to obtain sulfonated graphene sGr, and wrapping polyaniline PANI in V₂O₅The surface to increase its conductivity to promote rapid formation of a passivation film. At the same time, PANI-wrapped vanadium Pentoxide (PV) is self-assembled with sGr through pi-pi interaction to obtain sGr @ PV powder. Finally, the acrylic emulsion is mixed with amino resin, and sGr @ PV powder is used as reinforcement in a physical blending mode in the mixing processThe agent is introduced to obtain the water-based high-hardness and anti-corrosion amino baking paint which has excellent mechanical property and corrosion resistance.

Description

Corrosion-resistant water-based amino baking paint and preparation method thereof

Technical Field

The invention belongs to the technical field of water-based paint, and particularly relates to corrosion-resistant water-based amino baking paint and a preparation method thereof.

Background

Nowadays, aqueous coatings are attracting much attention due to restrictions on Volatile Organic Compound (VOC) emission and use. Meanwhile, water-based coatings have a series of potential advantages, such as environmental protection, non-toxicity, non-flammability, low energy curing, etc., while solvent-based coatings do not provide these functions. Aqueous acrylic resins have been widely used in various industries such as automobile, leather industry and construction field due to their excellent properties including gloss retention, color retention, heat resistance and corrosion resistance. However, aqueous acrylic resins have problems of durability and inherent chemical stability, which may be attributed to two reasons, namely poor adhesion to substrates and poor water resistance. Since the mechanical properties of waterborne coatings are mainly determined by the intrinsic properties of the reinforcement and the interaction with the matrix resin, researchers have primarily looked from both aspects.

Graphene is a two-dimensional carbon layer with a single atomic thickness, is considered to be the strongest material from history, and has aroused great interest in developing various novel composite materials. Compared with carbon nanotubes, Graphene Nanoplatelets (GNs) have fewer entanglements, larger specific surface area, lower production cost and are therefore ideal candidates for mechanical reinforcement of polymers. At the same time, because of their strong tendency to aggregate and highly inert surfaces, in order to fully exploit the potential of graphene, molecular-level dispersion and efficient stress transfer must be achieved at the interface. For graphene oxide, hydroxyl and carboxyl groups may be used to alter their surface properties. However, graphene oxide is thermally unstable and starts to decompose even at temperatures below 100 ℃, in contrast to thermally or chemically reduced surface-active substances with higher thermal stability, but the reduction of functional groups seriously impairs the ability of the surface-active substances to disperse in organic media.

Disclosure of Invention

The invention aims to provide a water-based acrylic amino baking varnish and a preparation method thereof. The invention utilizes the excellent mechanical property of graphene and the barrier property of graphene on moisture, oxygen and other gases and liquids to improve the amino group of the waterborne acrylic acidWeather resistance of baking varnish. Because the graphene has poor dispersibility in water, the diazo solution is adopted to sulfonate the graphene, and the hydrophilicity of sulfonic acid groups is utilized to improve the dispersibility of the graphene in the emulsion. In addition, Polyaniline (PANI) is wrapped in vanadium pentoxide (V)₂O₅) The surface is coated to increase the conductivity of the surface, so that the rapid formation of a passivation film is promoted, and meanwhile, PANI-coated vanadium Pentoxide (PV) is self-assembled with sGr through pi-pi interaction. And finally, sGr @ PV powder is introduced to be used as a reinforcing agent, so that the anti-corrosion performance of the amino baking paint is improved.

The invention adopts the following solution:

the corrosion-resistant water-based amino baking paint comprises the following components in percentage by mass:

50-60% of self-made water-based acrylic emulsion

6 to 10 percent of amino resin

30 to 40 percent of deionized water

sGr @ PV 0.1-0.5%

0.1 to 0.5 percent of defoaming agent

0.1 to 0.5 percent of flatting agent

0.5 to 1 percent of N, N-dimethylethanolamine

The sum of the total mass fractions is 100%.

Wherein the amino resin is high methylated amino resin, and is purchased from Suzhou Qingtian New Material Co., Ltd, model number AA-9077.

The preparation method of the corrosion-resistant water-based amino baking paint comprises the following steps:

(1) preparation of rGO:

preparing graphene oxide (GO for short) by improving a Hummers method; 0.2gGO was sonicated for 30min and stirred at room temperature for 1 hour. And then adding 0.1g of glucose as a reducing agent, pouring the mixture into a hydrothermal kettle, standing for 4 hours in an oven at the temperature of 50 ℃, and then heating the oven to 120 ℃ to react for 8 hours to obtain reduced graphene oxide (short for rGO). Finally, the mixed product was centrifuged and washed with absolute ethanol to remove residual glucose, then washed with deionized water to achieve neutrality, and freeze-dried to give a black powder, called rGO.

(2) sGr preparation:

weighing 0.72g of sulfanilic acid and 0.18g of NaOH, dissolving in 11ml of deionized water, heating to fully dissolve, placing a beaker in an ice bath to 0-5 ℃, and weighing 0.288g of NaNO₂And added under constant stirring by a magnetic stirrer. Then 3.8ml of hydrochloric acid is added into the mixed solution dropwise within 10min, and the temperature is controlled below 5 ℃ to continue stirring for 30min, so as to obtain a light yellow diazonium salt solution (ready to use).

0.1g rGO was dispersed in 50ml deionized water by sonication, the resulting rGO dispersion was poured into a diazonium salt solution, stirred in an ice bath overnight, and finally the solution was centrifuged to neutrality and lyophilized to give sulfonated graphene, designated sGr. 0.05g of sGr was dispersed by sonication in 20g of deionized water to give sGr as a suspension dispersion.

(3) sGr @ PV preparation

1 gV is mixed₂O₅The nanoparticles were added to 100mL of deionized water and shaken ultrasonically until a homogeneous suspension was obtained. Using hydrochloric acid solution to separate V₂O₅The pH of the suspension was adjusted to 1. Then, 1g of aniline monomer was added to the above acidic solution under ice bath conditions (0-5 ℃). Next, a dispersion of ammonium persulfate (2.3 g of APS and 7.7g of deionized water) was added dropwise to the mixture over 10min and stirring was continued at 0-5 ℃ for 4 h.

The washed reaction product was then separated by centrifugation at 8000r/min for 10 minutes to obtain V₂O₅The @ PANI (PV) hybrid, 0.05gPV hybrid was redispersed in 20g deionized water by sonication to give a PV suspension. The sGr dispersion prepared in step (2) was then added to the PV suspension and the resulting sGr @ PV was washed 3 times with deionized water to remove unreacted material after ultrasonic vibration at 300w for 1 h.

(4) Preparation of aqueous acrylic emulsion:

the preparation method adopts a semi-continuous dropwise addition seed emulsion polymerization method, and comprises the steps of firstly, preparing a seed emulsion by using a four-component reactor equipped with a condenser pipe, a stirrer and a nitrogen protection deviceDeionized water, 0.12gOP-10 (polyoxyethylene octylphenol ether-10), 0.12g emulsifier compounded with SDS (sodium dodecyl sulfate), and 0.2g NaHCO were added into the flask₃As a buffer, a mixture of 14g of methyl methacrylate (MMA for short) and 2g of Butyl Acrylate (BA) was slowly dropped into a four-necked flask while stirring and mixing at 250 r/min, and the mixture was allowed to stand at 30 ℃ for 1 hour after dropping within 30 minutes to obtain a seed emulsion of a core layer.

4g of MMA and 8g of BA as main monomers, AA2g as a functional monomer, 2g of hydroxyethyl methacrylate (HEMA for short), 0.18gOP-10 g of emulsifier and 0.18g of SDS are added into a conical flask filled with deionized water, and stirred for 1 hour at 30 ℃ under the same condition to prepare a shell layer pre-emulsion.

0.2g of ammonium persulfate APS was weighed and dissolved in 10g of deionized water to obtain an initiator solution, and 1/3 of the initiator solution was added to the four-neck flask after the temperature was raised to 65 ℃. Reacting for 30min to obtain blue-emitting seed emulsion, reacting for 0.5 h at 65 ℃, starting to dropwise add the pre-emulsion of the shell layer and the rest initiator for 1-2 h, and heating to 80 ℃ to react for 4 h. And after the reaction is completed, cooling to room temperature, adjusting the pH value to 7-7.5, and discharging to obtain the acrylic emulsion.

(4) sGr @ PV/waterborne acrylic amino stoving varnish preparation:

adding amino resin into the hydroxyl water-based acrylic emulsion obtained in the step (3), adjusting the pH to about 8 by using N-N dimethylethanolamine, stirring at the speed of 400-1000 r/min for 20 min, introducing the prepared sGr @ PV powder, a defoaming agent and a leveling agent, and stirring at the speed of 800-1000 r/min for 30min to obtain sGr @ PV water-based acrylic amino baking paint.

The invention has the following remarkable advantages:

1. compared with the water-soluble acrylic amino baking paint on the market, the emulsion acrylic amino baking paint has extremely low VOC emission, and the water-soluble acrylic amino baking paint needs an organic auxiliary agent to assist the dissolution and dispersion in water, so that the VOC emission is still not low in the film forming process.

2. The invention wraps Polyaniline (PANI) in vanadium pentoxide (V)₂O₅) Surface ofTo increase its conductivity (as shown in fig. 4), thereby promoting rapid formation of a passivation film.

3. PV is combined with the modified graphene in a self-assembly mode through pi-pi interaction between polyaniline and graphene. And pi-pi interactions allow PV to disperse well in water as well. From (c) in FIG. 5, it can be seen that sGr @ PV/acrylic amino stoving varnish 24h was also uniformly dispersed, whereas PV had sunk in the PV-added amino stoving varnish.

4. According to the invention, a hydrothermal method is adopted, and the reduction of the graphene oxide is completed in a closed hydrothermal kettle at one time. Wherein, water is used as a solvent glucose as a reducing agent, so the method has the advantages of simplicity, easy amplification, environmental protection and the like, and has high industrialization possibility.

5. According to the method, the graphene is sulfonated by using diazonium salt with sulfonic acid groups, and the graphene prepared by a hydrothermal method is insoluble in water, so that the sulfonic acid groups are directly grafted to the surface of the graphene by using active free radicals in the diazonium salt solution, and the hydrophilic graphene is obtained.

Drawings

FIG. 1 is a scanning electron micrograph of rGO;

FIG. 2 is a scanning electron micrograph of sGr;

FIG. 3 is an energy spectrum of sGr;

FIG. 4 is the conductivity of each feedstock;

in fig. 5 (a) is rGO aqueous solution and sGr aqueous solution after ultrasonic dispersion; (b) placing the rGO aqueous solution and the sGr aqueous solution after ultrasonic dispersion for 24 hours; (c) after 24h of standing example 3 and comparative example 3.

Detailed Description

The present invention will be further described with reference to specific examples, but the present invention is not limited to these examples.

Example 1:

(1) preparation of rGO:

(2) sGr preparation:

0.1g of rGO was dispersed in 50ml of deionized water by ultrasound, the rGO dispersion was poured into the diazonium salt solution prepared above, stirred overnight in an ice bath, and finally the solution was centrifuged to neutrality and lyophilized to give sulfonated graphene, designated sGr, and 0.05g of sGr was weighed and dispersed in 20g of deionized water by ultrasound to give sGr dispersion.

(3) sGr @ PV preparation

1 gV is mixed₂O₅The nanoparticles were added to 100mL of deionized water and shaken ultrasonically until a homogeneous suspension was obtained. Using hydrochloric acid solution to separate V₂O₅The pH of the suspension was adjusted to 1. Then, 1g of aniline monomer was added to the above acidic solution under ice bath conditions (0-5 ℃). Next, an ammonium persulfate dispersion (2.3 g APS and 7.7g deionized water) was added to the mixture over 10min and stirring was continued at 0-5 ℃ for 4 h.

The washed reaction product was separated by centrifugation at 8000r/min for 10 minutes to obtain V₂O₅@ PANI (PV) hybrid, 0.05gPV hybrid ultrasonically dispersed in 20g deionized water to give a PV suspension, then prepared sGr dispersion was added to the PV suspension, followed by ultrasonic vibration at 300w for 1h, and the obtained sGr @ PV was removedThe ionized water was washed 3 times to remove unreacted materials.

(4) Preparation of aqueous acrylic emulsion:

the preparation method adopts a semi-continuous dropwise addition seed emulsion polymerization method, and comprises the steps of firstly, sequentially adding 40g of ionized water, 0.12g of emulsifier compounded by OP-10 and 0.12g of SDS and 0.2g of NaHCO into a four-neck flask provided with a condenser, a stirrer and a nitrogen protection device₃As a buffer, 14g of MMA and 2g of BA as seed monomers were added dropwise slowly over 30min to a four-necked flask while stirring and mixing at 250 r/min, and the mixture was incubated at 30 ℃ for 1 hour to obtain a seed emulsion for a core layer.

4g of MMA, 8g of BA, 2g of AA, 2g of HEMA as the main monomer, 0.18g of OP-10 as the emulsifier and 0.18g of SDS as the functional monomer were put into a conical flask containing 10g of deionized water, and stirred at 30 ℃ for 1 hour under the same conditions to prepare a shell pre-emulsion.

0.2g of APS was weighed out and dissolved in 10g of deionized water to give an initiator solution, and 1/3 of the initiator solution was added to the four-neck flask after the temperature had risen to 65 ℃. Reacting for 30min to obtain blue-emitting seed emulsion, reacting at 65 deg.C for 0.5 h while maintaining the temperature, adding the pre-emulsion of shell layer and the rest initiator dropwise for 1-2 h, and heating to 80 deg.C for 4 h. And after the reaction is completed, cooling to room temperature, adjusting the pH value to 7-7.5, and discharging to obtain the water-based acrylic emulsion.

(5) Preparation of water emulsion type acrylic amino baking varnish:

adding amino resin into acrylic emulsion, adjusting the pH value to 8 by using N-N dimethylethanolamine, stirring at the speed of 600 r/min for about 30min, then introducing prepared sGr @ PV powder, a defoaming agent and other auxiliaries, increasing the rotating speed to 1000 r/min, and stirring for 30min to obtain the corrosion-resistant water-based amino baking paint. The self-made water-based acrylic amino baking paint comprises the following components in percentage by mass:

58 percent of self-made acrylic emulsion

32.7 percent of deionized water

0.1 percent of defoaming agent

0.1 percent of flatting agent

8 percent of high methylated amino resin

sGr @ PV 0.1%

1% of N, N-dimethylethanolamine.

Example 2:

steps (1) to (4) referring to example 1

(5) Preparation of water emulsion type acrylic amino baking varnish:

58 percent of self-made acrylic emulsion

32.6 percent of deionized water

0.1 percent of defoaming agent

0.1 percent of flatting agent

8 percent of high methylated amino resin

sGr @ PV 0.2%

1% of N, N-dimethylethanolamine.

Example 3:

steps (1) to (4) referring to example 1

(5) Preparation of water emulsion type acrylic amino baking varnish:

58 percent of self-made acrylic emulsion

32.5 percent of deionized water

0.1 percent of defoaming agent

0.1 percent of flatting agent

8 percent of high methylated amino resin

sGr @ PV 0.3%

1% of N, N-dimethylethanolamine.

Example 4:

steps (1) to (4) referring to example 1

(5) Preparation of water emulsion type acrylic amino baking varnish:

58 percent of self-made acrylic emulsion

32.4 percent of deionized water

0.1 percent of defoaming agent

0.1 percent of flatting agent

8 percent of high methylated amino resin

sGr @ PV 0.4%

1% of N, N-dimethylethanolamine.

Example 5

Steps (1) to (4) referring to example 1

(5) Preparation of water emulsion type acrylic amino baking varnish:

adding amino resin into acrylic emulsion, adjusting the pH value to about 8 by using N-N dimethylethanolamine, stirring at the speed of 600 r/min for about 30min, introducing prepared sGr @ PV powder, a defoaming agent and other auxiliaries, increasing the rotating speed to 1000 r/min, and stirring for 30min to obtain the corrosion-resistant water-based amino baking paint. The self-made water-based acrylic amino baking paint comprises the following components in percentage by mass:

58 percent of self-made acrylic emulsion

32.3 percent of deionized water

0.1 percent of defoaming agent

0.1 percent of flatting agent

8 percent of high methylated amino resin

sGr @ PV 0.5%

1% of N, N-dimethylethanolamine.

Comparative example 1

(1) Preparation of acrylic emulsion:

the preparation method adopts a semi-continuous dropwise addition seed emulsion polymerization method, and comprises the steps of firstly, sequentially adding 40g of ionized water, 0.12g of emulsifier compounded by OP-10 and 0.12g of SDS and 0.2g of NaHCO into a four-neck flask provided with a condenser, a stirrer and a nitrogen protection device₃As a buffer, 14g of MMA and 2g of BA as seed monomers were gradually added dropwise to a four-necked flask while stirring and mixing at 250 r/min, and the mixture was incubated at 30 ℃ for 1 hour to obtain a seed emulsion of a core layer.

0.2g of APS was weighed out and dissolved in 10g of deionized water to give an initiator solution, and 1/3 of the initiator solution was added to the four-neck flask after the temperature had risen to 65 ℃. Reacting for about 30min to obtain blue-emitting seed emulsion, reacting at 65 deg.C for 0.5 h, adding the pre-emulsion of shell layer and the rest initiator dropwise for 1-2 h, and heating to 80 deg.C for 4 h. And after the reaction is completed, cooling to room temperature, adjusting the pH value to 7-7.5, and discharging to obtain the water-based acrylic emulsion.

(2) Preparation of water emulsion type amino baking varnish:

adding amino resin into the acrylic emulsion obtained in the step (1), adjusting the pH value to 8 by using N-dimethylethanolamine, stirring at the speed of 600 r/min for about 30min, adding a leveling agent and a defoaming agent, and increasing the rotating speed to 1000 r/min for stirring for 30min to obtain the corrosion-resistant amino baking paint. The self-made water-based amino baking paint comprises the following components in percentage by mass:

58 percent of self-made acrylic emulsion

32 percent of deionized water

0.1 percent of defoaming agent

0.1 percent of flatting agent

8 percent of high methylated amino resin

1% of N, N-dimethylethanolamine.

Comparative example 2

(1) Preparation of acrylic emulsion: preparation of aqueous acrylic emulsion reference is made to the emulsion preparation in example 1, (2) preparation of water-emulsion acrylic amino stoving varnish:

adding amino resin into acrylic emulsion, adjusting pH to about 8 with N-dimethylethanolamine, stirring at 600 r/min for about 30min, and introducing V₂O₅The powder and the same auxiliary agent as in example 1 are stirred for 30min at the rotating speed of 1000 r/min to obtain the corrosion-resistant water-based amino baking paint. The self-made water-based acrylic amino baking paint comprises the following components in percentage by mass:

58 percent of self-made acrylic emulsion

32.5 percent of deionized water

0.1 percent of defoaming agent

0.1 percent of flatting agent

8 percent of high methylated amino resin

V₂O₅ 0.3%

1% of N, N-dimethylethanolamine.

Comparative example 3

(1) Preparation of aqueous acrylic emulsion: emulsion preparation in reference example 1;

(2) preparation of PV powder reference example 1 step (3);

(3) preparation of water emulsion type acrylic amino baking varnish:

adding amino resin into acrylic emulsion, adjusting the pH value to about 8 by using N-N dimethylethanolamine, stirring at the speed of 600 r/min for about 30min, then introducing the prepared PV powder and the auxiliary agent which is the same as that in the example 1, and increasing the rotating speed to 1000 r/min for stirring for 30min to obtain the corrosion-resistant water-based amino baking paint. The self-made water-based acrylic amino baking paint comprises the following components in percentage by mass:

58 percent of self-made acrylic emulsion

32.5 percent of deionized water

0.1 percent of defoaming agent

0.1 percent of flatting agent

8 percent of high methylated amino resin

PV 0.3%

1% of N, N-dimethylethanolamine.

Performance testing

The emulsion acrylic amino baking varnish prepared in the embodiment and the comparative example is compared and detected to obtain tables 1 and 2, the determination methods of the technical indexes of the invention are all standard methods used in the field, the paint film and the acid and alkali resistance are determined according to national standard GB/T1763-79 (89) determination method for chemical reagent resistance of the paint film, the chemical reagent resistance of the paint film is represented by the surface change phenomenon of the paint film after the specified test time is reached, and the neutral salt spray resistance test is carried out on the paint film according to national standard GB/T1771 and 2007. The pencil hardness of the paint film is tested according to GB/T6739-1998, and the paint film adhesion is tested according to GB 9286-1998. The flexibility test of the paint film is tested according to GB/T6742-2007 standard.

TABLE 1 mechanical Properties of the aqueous amino baking varnish films of the examples

TABLE 2 Corrosion resistance test of amino baking varnish films of the examples

It can be seen from tables 1 and 2 that the optimum mechanical properties in each case for a pencil hardness of 5H and at the same time the optimum corrosion resistance are achieved at a powder content of sGr @ PV of 0.3 wt.%. However, when the sGr @ PV level exceeds 0.3wt%, the performance begins to decline. The reason is that when the content of the sulfonated graphene is not high, the sulfonated graphene can be uniformly dispersed in a paint film, so that the excellent performance of the graphene can be fully exerted, however, with the increase of the sGr @ PV content, the graphene and the filler are agglomerated, and a stress concentration point exists in the paint film, so that the performance of the paint film is reduced.

TABLE 3 Corrosion resistance test of amino baking varnish films of the examples

The results show that V is produced by incorporation of PV₂O₅And sGr @ PV hybrid, improve the corrosion resistance of acrylic amino stoving varnish. However, due to V₂O₅Is poor in water dispersibility and conductivity, and thus, addition thereof only to the emulsion does not exhibit remarkable corrosion preventing properties. In addition, PV/acrylic amino stoving lacquers and V₂O₅The acrylic amino stoving lacquers have better protective properties than acrylic amino stoving lacquers, which are attributed to the improved dispersibility of the PV in the resin system. Another reason is that the conductivity of the PV nanoparticles is improved by the introduction of PANI, thereby facilitating the formation of the passivation film. In contrast, sGr @ PV/acrylic amino stoving varnish exhibited the highest corrosion protection capability due to the excellent barrier properties of Gr.

Claims

1. The corrosion-resistant water-based amino baking paint is characterized by comprising the following raw materials in percentage by weight: 25-45% of self-made acrylic emulsion, 4-8% of amino resin, 0.1-0.5% of reinforcing agent, 0.1-0.5% of defoaming agent, 0.1-0.5% of flatting agent, 22.4-35.9% of deionized water, 0.5-1% of N-dimethylethanolamine, and the sum of the total mass fraction is 100%.

2. The preparation method of the corrosion-resistant water-based amino baking paint according to claim 1, characterized in that: the reinforcing agent is prepared by the following method:

step 1, preparing graphene oxide GO by improving a Hummers method;

step 2, obtaining reduced graphene oxide rGO by glucose through a hydrothermal reaction;

step 3, sulfonating the rGO in the step 2 by using a self-made diazonium salt solution, and performing centrifugal freeze-drying to obtain black powder, sGr for short; 0.05g of sGr is taken and dispersed in 20g of deionized water by ultrasonic to obtain sGr suspension dispersion;

step 4, at V₂O₅Polymerizing the polyaniline layer on the nano particles in situ, and centrifuging to obtain a reaction product V₂O₅The @ PANI hybrid, abbreviated PV; dispersing 0.05gPV in deionized water by ultrasonic to obtain PV suspension;

step 5, the prepared sGr dispersion was then added to the PV suspension, followed by sonication to obtain sGr @ PV.

3. The preparation method of the corrosion-resistant water-based amino baking paint according to claim 2, characterized in that: the step 3 specifically comprises the following steps: weighing 0.72g of sulfanilic acid and 0.18g of NaOH, dissolving in deionized water, heating to fully dissolve, placing a beaker in an ice bath to 0-5 ℃, and then, adding 0.288g of NaNO₂Adding into a magnetic stirrer under continuous stirring, adding 3.8ml hydrochloric acid dropwise into the mixed solution within 10min, and stirring at below 5 deg.C for 30min to obtain light yellow diazonium salt solution; dispersing 0.1grGO in 50ml of deionized water by ultrasonic, pouring the rGO dispersion into the prepared diazonium salt solution, stirring overnight in an ice bath, finally centrifuging the solution to neutrality and freeze-drying to obtain sulfonated graphene, named sGr, weighing 0.05g of sGr, and dispersing in 20g of deionized water by ultrasonic to obtain sGr dispersion.

4. The preparation method of the corrosion-resistant water-based amino baking paint according to claim 2, characterized in that: the step 4 specifically comprises the following steps: will V₂O₅The nanoparticles are added to 100ml of deionized water and shaken ultrasonically until a homogeneous suspension is obtained, V is added with a hydrochloric acid solution₂O₅The pH of the suspension was adjusted to 1, then aniline monomer was added to the above acidic solution under ice bath conditions 0-5 ℃, followed by the addition of ammonium persulfate dispersion, 2.3g aps and 7.7g deionized water, slowly dropwise to the above mixture, and stirring continued at 0-5 ℃ for 4 h; separating the reaction product by centrifugation to obtain V₂O₅@ PANI hybrid, PV was dispersed in 20ml deionized water by sonication to give a PV suspension.

5. The preparation method of the corrosion-resistant water-based amino baking paint according to claim 2, characterized in that: step 5 was specifically to add the prepared sGr dispersion to the PV suspension followed by ultrasonic vibration at 300w for 1h and the resulting sGr @ PV was washed with deionized water by suction filtration to remove unreacted material.

6. The preparation method of the corrosion-resistant water-based amino baking paint according to claim 2, characterized in that: step 4V₂O₅The mass ratio of the aniline monomer to the aniline monomer is 1: 1.

7. The preparation method of the corrosion-resistant water-based amino baking paint according to claim 1, characterized in that: the mass ratio of PV to sGr in step 5 was 1: 1.

8. The preparation method of the corrosion-resistant water-based amino baking paint according to claim 1, characterized in that:

the self-made acrylic emulsion is prepared by the following method:

step S1 is prepared by semi-continuous dropwise addition of seed emulsion polymerization method, and comprises sequentially adding deionized water, emulsifier composed of 0.12g sodium dodecyl sulfate SDS and 0.12g nonionic emulsifier OP-10, and 0.2g NaHCO into a four-neck flask equipped with condenser, stirrer and nitrogen protection device₃As a buffering agent, stirring and mixing at 250 r/min, slowly dripping seed monomers of Methyl Methacrylate (MMA) and Butyl Acrylate (BA) into a four-neck flask, finishing dripping within 30min, and preserving heat at 30 ℃ for 1h to obtain seed emulsion of a nuclear layer;

step S2, adding shell monomers MMA and BA, functional monomers AA and hydroxyethyl methacrylate HEMA, and emulsifiers of 0.18g OP-10 and 0.18g SDS into a conical flask filled with 10g deionized water, and stirring for 1h under the same condition to prepare a shell pre-emulsion;

step S3, weighing 0.2g of ammonium persulfate APS, dissolving in deionized water to obtain an initiator solution, heating to 65 ℃, adding 1/3 of the initiator solution into the four-neck flask in the step S1, reacting for 30min to obtain a blue-emitting seed emulsion, keeping the temperature at 65 ℃ for reaction for 0.5 h, beginning to dropwise add the pre-emulsion with the shell layer prepared in the step S2 and the rest of the initiator, dropwise adding for about 1-2 h, heating to 80 ℃, and reacting for 4 h; and after the reaction is completed, cooling to room temperature, adjusting the pH value to 7-7.5, and discharging to obtain the acrylic emulsion.

9. The preparation method of the corrosion-resistant water-based amino baking paint according to claim 8, characterized in that: the mass ratio of the core layer to the shell layer monomer of the water-based acrylic emulsion is 3: 2.

10. The preparation method of the corrosion-resistant water-based amino baking paint according to claim 1, characterized in that: the amino resin is 40wt% of high solid content and methylated amino resin, and is purchased from Suzhou Qingtian New Material Co., Ltd, model AA-9077.