CN115353777A - Preparation method of high-permeability conversion rust-free anticorrosive primer - Google Patents

Abstract

The invention discloses a preparation method of a high-permeability conversion rust-free anticorrosive primer, which belongs to the technical field of static conductive coatings, and is characterized in that a novel aqueous polymer synthetic latex formed by compounding vinylidene chloride-butadiene copolymer latex serving as a main raw material with natural flake graphite and lepidolite is non-toxic, odorless, non-combustible, strong in permeability, oxygen-moisture resistant, chloride ion resistant and the like, excellent in film forming performance, low in film forming temperature, compact in film forming, strong in adhesive force, and much lower in air permeability after film forming than that of oil paint and common latex paint, has good acid-base resistance and salt corrosion resistance, can be prepared into various anticorrosive coatings, forms a compact film layer on the surface of steel, concrete and other substrates, and plays a good role in protecting the substrates.

Description

Preparation method of high-permeability conversion rust-free anticorrosive primer

Technical Field

The invention belongs to the technical field of anticorrosive coatings, and particularly relates to a preparation method of a high-permeability conversion rust-free anticorrosive primer.

Background

The rust removing paint has the advantages of various environments, easy corrosion and large surface treatment workload, so that the paint varieties which can adapt to simplified rust removing procedures and can be applied only by removing loose rust layers, the paint varieties which can be applied under severe weather conditions, the paint varieties which can be maintained on site in rainy days or wet and cold days, the paint varieties which can be applied underwater, and the like are urgently needed. The existing rust-bearing coating or rust-removing anticorrosive coating is practically used on a common steel structure on the premise of removing a loose floating rust layer, and is not frequently used on large projects. Technically, it is feasible to use the rust-free coating variety on the water engineering steel structure. In fact, there is a process of examination and recognition in mass application, which is yet to be explored. The rust-free paint is an anticorrosive paint product of an anticorrosive paint composition directly coated on a rusty base material, can be widely applied to chemical equipment and pipe frames, offshore oil production platforms, bridges, electric towers, shipbuilding and protection and direct coating for corrosion prevention of various steel and iron components for buildings, can be directly constructed on the surfaces of moist, accumulated water and slightly rusted steel or concrete, has excellent anticorrosive performance, avoids a sand blasting pretreatment process on the basis of the constructed steel structure, and greatly reduces the construction difficulty and the engineering maintenance cost. Metal and concrete are corroded by oxygen, moisture and other impurities in the atmosphere, so that the appearance, color, mechanical properties and the like of the metal and concrete are damaged, and more importantly, the precision, sensitivity and the like of the metal and concrete are lost and even scrapped, so that the research on the corrosion prevention technology is of great significance. In the past, the solvent type rusty antirust coating developed in China has single variety, contains a large amount of organic solvent, lead, chromium and other antirust pigments, has high toxicity and seriously pollutes the environment. Overcomes the defects of solvent type rusty anticorrosive coatings, and is a hotspot for researching the rusty anticorrosive coatings at present. The development of a method for preparing a rust-free anti-corrosion primer with high penetration conversion is urgently needed by the technical personnel in the field so as to meet the existing use requirement and performance requirement.

Disclosure of Invention

In view of the above problems, the present invention aims to provide a method for preparing a high penetration conversion rust-free anticorrosion primer.

The invention is realized by the following technical scheme:

a preparation method of a high-permeability conversion rust-free anticorrosive primer specifically comprises the following steps: sequentially adding butadiene, vinylidene chloride, methyl olefine acid monomer and stabilizer into a high-pressure reaction kettle, stirring and mixing uniformly, sealing a kettle cover, introducing nitrogen with the pressure of 0.4 to 0.7Mpa, introducing the nitrogen for a period of time to exhaust air in the kettle, pressurizing to 0.25MPa after a sealing device, heating to 60 ℃, taking an aqueous solution in which an emulsifier with the mass fraction of 0.4 to 0.5 percent and an initiator with the mass fraction of 0.5 to 0.6 percent as an emulsification initiating solution, adding an emulsification initiating solution with the total weight of 15 percent as seed latex, after a reaction system turns blue, dropwise adding the rest emulsification initiating solution, controlling the dropwise adding at a constant speed within 3 hours, then adding 45 to 48 parts of an aqueous solution of a reducing agent with the mass fraction of 4 percent, keeping the temperature at 60 ℃, stopping heating after 20min of heat preservation, reducing the pressure, filtering and discharging to obtain vinylidene chloride-butadiene copolymer latex with the solid content of 48 to 52 percent;

lepidolite, also called lepidolite, is a common lithium mineral that is insoluble in acid solutions. The natural flake graphite is similar to shrimp phosphorus, has a layered structure and is acid and alkali resistant. Step two: dispersing a mixture of natural flake graphite and lepidolite in a mixed solution of 150 parts of Tris-HCl buffer solution and 45-50 parts of absolute ethyl alcohol at a bath ratio of 1: 5~6 for 20min by ultrasonic treatment to obtain a flake dispersion liquid, dispersing 5~6 parts of dopamine hydrochloride in the flake dispersion liquid for 20min by ultrasonic treatment, adjusting the pH value to 8.5 by using a sodium hydroxide solution with the mass fraction of 8-10%, magnetically stirring for 2h at 500-550r/min, centrifuging by using a high-speed centrifuge of 8000r/min, rinsing the centrifuged product for 3 times by using deionized water, and finally drying in an oven at 60 ℃ to constant weight to obtain flake materials; and step three, adding the vinylidene chloride-butadiene copolymer latex, the flake material and the auxiliary agent into a high-speed dispersion machine, shearing and stirring at a high speed, then putting into a hopper of a conical mill, and stopping grinding when the fineness is less than 40 mu m after grinding by using a scraper fineness gauge.

And further, in the third step, 25 to 30 parts of a flake material, 76 to 90 parts of vinylidene chloride-butadiene copolymer latex and 12 to 14 parts of other auxiliary agents are calculated according to the weight parts.

Further, the step-methacrylic acid monomer is one or more of methyl crotonic acid and methacrylic acid.

Further, the first emulsifier is selected from hydrogenated soybean lecithin, carbomer 1312 and beta-cyclodextrin.

Further, the stabilizer in the first step is N-isopropylidene aniline, wherein the weight ratio of butadiene, vinylidene chloride, a methyl olefine acid monomer, the stabilizer and the emulsification initiation solution is 30 to 33: 130 to 135: 1~2: 0.05.

Further, the first initiator is ammonium persulfate or azobisisobutylamidine hydrochloride, and the reducing agent is one of sodium metabisulfite and vitamin C.

Further, the other auxiliary agents comprise 5-8 wt% of a film forming auxiliary agent, 10-12wt% of a defoaming agent, 8-10 wt% of a leveling agent, 12-15% of a dispersing agent and the balance of a rust conversion agent in a weight percentage, wherein the total is 100%, the film forming auxiliary agent is one or more of 3-ethoxyethyl propionate EEP, 2,2,4-trimethyl-1,2-pentanediol-isobutyl monoester Nexcoat 795, the defoaming agent is one or more of Corning A10, BYK028 and air chemistry 104E, the leveling agent is one or two of DC 5211 and EFKA 3777, the dispersing agent is one or more of BYK 190, dow 731A and Cyanut 6208, and the rust conversion agent is 3,4,5-hydroxy-2-oxime benzoic acid.

The beneficial effects of the invention are:

the invention utilizes the copolymerization of butadiene and vinylidene chloride, and the high-strength hydrogen bond of the coating can be regarded as electrostatic attraction due to the generation of hydrogen intermolecular bonds, and the electrostatic attraction is generated when dipole moments interact. The butadiene vinylidene chloride latex containing carboxyl has high strength and can generate an effective network of intermolecular bonds. Lepidolite, also called lepidolite, is a common lithium mineral that is insoluble in acid solutions. The flaky material is added into the vinylidene chloride-butadiene copolymer latex to divide the latex into a plurality of small spaces, so that the phenomenon of stress concentration in the latex is effectively improved, and the staggered arrangement is formed among the flaky materials, so that the medium infiltration becomes roundabout and tortuous, the path of the corrosive medium diffusing to the matrix resin is increased, the time of infiltrating into the matrix is prolonged, and the corrosion resistance of the coating is improved. The rust conversion agent can react with the iron rust to generate stable chelate with the iron rust, and the stable chelate is effectively passivated and sealed to achieve the shielding and corrosion prevention effects.

Compared with the prior art, the invention has the following advantages:

lepidolite, also called lepidolite, is a common lithium mineral that is insoluble in acid solutions. The natural flake graphite is similar to shrimp phosphorus, has a layered structure and is acid and alkali resistant. The two materials are rich in resources, good in quality and low in price, the environment-friendly effect is superior to that of the traditional glass flake and basalt flake, and the anti-corrosive paint filled with lepidolite and natural flake graphite is ideal high-anti-corrosive paint.

Detailed Description

The invention is illustrated by the following specific examples, which are not intended to be limiting.

Example 1

The preparation method of the high-permeability conversion rust-free anticorrosive primer comprises the following steps:

sequentially adding butadiene, vinylidene chloride, methyl olefine acid monomer and stabilizer into a high-pressure reaction kettle, wherein the stabilizer is N-isopropylidene aniline, the weight ratio of butadiene to vinylidene chloride to methyl olefine acid monomer to stabilizer to an emulsion initiating solution is 33: 135: 2: 0.05, the methyl olefine acid monomer is methyl butenoic acid and methacrylic acid, uniformly stirring and mixing, sealing a kettle cover, introducing 0.7Mpa of nitrogen, introducing the nitrogen for a period of time to exhaust air in the kettle, pressurizing to 0.25MPa after a sealing device, heating to 60 ℃, taking an aqueous solution in which an emulsifier with the mass fraction of 0.5 percent and a 0.6 percent of initiator are dissolved as the emulsion initiating solution, the initiator is ammonium persulfate or azodiisobutyl amidine hydrochloride, the emulsifier selects carbomer 1312, adding the emulsion initiating solution with the total weight of 15 percent as seed latex, after a reaction system emits blue light, dropwise adding the rest emulsion initiating solution, controlling the dropwise addition of the emulsion initiating solution to be completely added within 3 hours, then adding 48 parts of an aqueous solution of a reducer with the mass fraction of 4 percent, releasing the reducer, sodium sulfite, vitamin C, keeping the temperature of the emulsion initiating solution for 60 min, filtering, keeping the temperature for 20-52 ℃, and filtering to obtain a copolymer latex; step two: dispersing south Jiang Sitong mining XLG10-99 natural crystalline flake graphite and lepidolite in a mixed solution of 150 parts of Tris-HCl buffer solution and 50 parts of absolute ethyl alcohol according to a bath ratio of 1: 6, performing ultrasonic treatment for 20min to obtain crystalline flake dispersion liquid, dispersing 6 parts of dopamine hydrochloride in the crystalline flake dispersion liquid, performing ultrasonic treatment for 20min, adjusting the pH value to 8.5 by using a sodium hydroxide solution with the mass fraction of 10%, performing magnetic stirring for 2h at 550r/min, performing centrifugal treatment by using a high-speed centrifuge with the speed of 8000r/min, rinsing the centrifuged product for 3 times by using deionized water, and finally drying in an oven with the temperature of 60 ℃ to constant weight to obtain the crystalline flake; and step three, adding the vinylidene chloride-butadiene copolymer latex, the flake materials and the auxiliary agents into a high-speed dispersion machine, shearing and stirring at a high speed, then putting the flake materials 30, the vinylidene chloride-butadiene copolymer latex 90 and the other auxiliary agents 14 in parts by weight into a hopper of a conical mill, and stopping grinding when the fineness is smaller than 40 mu m detected by a scraper fineness gauge after grinding. The other auxiliary agents comprise 8 percent of film forming auxiliary agent, 12 percent of defoaming agent, 10 percent of flatting agent, 15 percent of dispersing agent and the balance of rust converting agent by weight percentage, the total is 100 percent, the film forming auxiliary agent is 2,2,4-trimethyl-1,2-pentanediol-isobutyl monoester Nexcoat 795, the defoaming agent is air chemistry 104E, the flatting agent is EFKA 3777, the dispersing agent is cyanogen 6208, the rust converting agent is 3,4,5-hydroxy-2-oxime benzoic acid, yinchun tantalum niobium company first grade 800 mesh lepidolite.

The performance of the product coating is as follows: the bonding strength, the steel plate base material is 5.9MPa, the acid resistance is 10 percent of the H2SO4 solution, and the paint film is free from foaming, peeling and rusty spot after 72 hours; alkali resistance, 10 percent of NaOH solution, 72 hours, no bubbling, no peeling and no rust stain of a paint film; saline resistance, 3 percent of NaCl solution, 240 hours, and no bubbling, peeling and rust spots of a paint film; salt spray resistance, 1000 hours, no bubbling, peeling and rust stain on a paint film, 1000 mu m of penetration depth of a No. 45 steel plate and 2.8MPa of a concrete substrate.

Example 2

A preparation method of a high-permeability conversion rust-free anticorrosive primer specifically comprises the following steps:

sequentially adding butadiene, vinylidene chloride, methyl olefine acid monomer and stabilizer into a high-pressure reaction kettle, wherein the stabilizer is N-isopropylidene aniline, the weight ratio of butadiene, vinylidene chloride, methyl olefine acid monomer, stabilizer and emulsion initiating solution is 30: 130: 1: 0.05, the methyl olefine acid monomer is methyl butenoic acid and methacrylic acid, uniformly stirring and mixing, sealing a kettle cover, introducing 0.4Mpa of nitrogen, introducing the nitrogen for a period of time to exhaust air in the kettle, pressurizing to 0.25MPa after a sealing device, heating to 60 ℃, taking an aqueous solution in which an emulsifier with the mass fraction of 0.4wt% and an initiator with the mass fraction of 0.5wt% are dissolved as the emulsion initiating solution, the initiator is ammonium persulfate or azodiisobutyl amidine hydrochloride, selecting hydrogenated soybean lecithin as the emulsifier, adding the emulsion initiating solution with the total weight of 15% as seed latex, discharging blue light after a reaction system is developed, dropwise adding the rest emulsion initiating solution, controlling the dropwise addition within 3h, adding 45 parts of an aqueous solution with the mass fraction of a reducing agent, using sodium pyrosulfite, vitamin C as a pressure relief reducing agent, keeping the temperature for 60 min, and filtering to obtain a copolymer latex with the temperature of 48-48 ℃, and filtering the copolymer latex after the temperature is kept and the emulsion is kept at a constant; step two: dispersing south Jiang Sitong mining XLG5-99 natural crystalline flake graphite and lepidolite in a mixed solution of 150 parts of Tris-HCl buffer solution and 45 parts of absolute ethyl alcohol at a bath ratio of 1: 5, performing ultrasonic treatment for 20min to obtain crystalline flake dispersion liquid, dispersing 5 parts of dopamine hydrochloride in the crystalline flake dispersion liquid, performing ultrasonic treatment for 20min, adjusting the pH value to 8.5 by using a sodium hydroxide solution with the mass fraction of 8%, performing magnetic stirring for 2h at 500r/min, performing high-speed centrifugal treatment by using a 8000r/min centrifugal machine, rinsing the centrifuged product for 3 times by using deionized water, and finally putting the rinsed product in a 60 ℃ oven to dry to constant weight to obtain crystalline flake; and step three, adding the vinylidene chloride-butadiene copolymer latex, the flaky material and the auxiliary agent into a high-speed dispersion machine, shearing and stirring at a high speed, then putting 25 parts of the flaky material, 76 parts of the vinylidene chloride-butadiene copolymer latex and 12 parts of other auxiliary agents in parts by weight into a hopper of a conical mill, and stopping grinding when the fineness is smaller than 40 mu m detected by a scraper fineness gauge after grinding. The other auxiliary agents comprise 8 percent of film forming auxiliary agent, 12 percent of defoaming agent, 10 percent of flatting agent, 15 percent of dispersing agent and the balance of rust converting agent by weight percentage, the total is 100 percent, the film forming auxiliary agent is 3-ethoxy ethyl propionate EEP, the defoaming agent is Corning A10, the flatting agent is DC 5211, the dispersing agent is Dow 731A, and the rust converting agent is 3,4,5-hydroxy-2-oxime benzoic acid.

The performance of the product coating is as follows: the bonding strength, the steel plate base material is 6.0MPa, the acid resistance is 10 percent, the content of the H2SO4 solution is 72 hours, and a paint film does not blister, peel or rust stain; alkali resistance, 10 percent of NaOH solution, 72 hours, no bubbling, no peeling and no rust stain of a paint film; saline resistance, 3 percent of NaCl solution, 240 hours, and no bubbling, peeling and rust spots of a paint film; salt spray resistance, 1000h, no bubbling, no stripping, no rust spot, steel plate penetration depth of more than 1000 mu m, and concrete base material of more than or equal to 2.0MPa; .

The coating performances of the coating of the embodiment 1 and the coating of the embodiment 2 are tested, and the test results are shown in tables 1 and 2

Table 1 test results of coating concrete coating performance of examples 1 and 2

Table 2 concrete coating performance test results of examples 1 and 2

Note: concrete: the standard laboratory experimental conditions were: the temperature is 23 ℃, the relative humidity is 50%, the standard test conditions of the laboratory accord with GB/T9278-2008, and the sample and all the appliances are placed for at least 24 hours under the standard conditions before the test preparation and the test; dry time is determined by 16.2.1 in GB/T16777-2008, and dry time is determined by 16.2.2 in GB/T16777-2008. The solid content is measured according to the regulation of GB/T16777-2008 chapter 5, and the drying temperature is 105 ℃; the water content was measured according to JC475-2004 appendix A. The fineness is measured according to GB/T8077-2000 chapter 6 by screening of 0.63 mm; the content of chloride ions is measured according to GB/T176; wet base surface bonding strength, experimental apparatus prepared according to 7.1.1 in GB/T16777-2008; preparation of test specimensThe mortar block, tools and paint prepared before the test should be placed for more than 24 hours under the standard test conditions. The priming requirement is as follows: taking five concrete test blocks which accord with GB/T50081-2002, removing surface laitance by using No. 2 abrasive paper, brushing primer on a forming surface (70 multiplied by 70) mm of a mortar block according to the requirement of a production factory, stirring a sample for 20min according to the requirement of the production factory after drying, coating the sample on the forming surface, wherein the thickness of a coating film is more than or equal to 1.5mm, coating for 10 times, performing horizontal and vertical crossing, each coating is 0.3mm in thickness, performing subsequent coating after a previous coating is dried, standing for 6h at an interval time, standing for 168h under standard conditions, then placing the mortar block with oxygen protection in a 0 ℃ drying box for 48h, taking out, and placing in a dryer to cool to room temperature. Five test pieces were prepared. Test methods were determined as 7.2.7 in GB 18445-2012. The workability was determined in accordance with JG/T26-2002. Pouring the powder into the liquid material, stirring for a certain time, stirring according to the GB/T17671 standard stirring procedure, and then brushing the standard concrete plate or the asbestos cement plate with a brush. If the coating is smooth, the blade coating is free from obstacles; covering the rest materials with wet cloth, stirring at high speed for 30s in the stirrer after 20min, and brushing with brush again. If the coating is smooth, the blade coating is free from obstacles; tensile property test apparatus is identical to 4.1 and 9.1 in GB/T16777-2008, sample and sample preparation 6 intercoat requirements: weighing appropriate amount of liquid and solid components respectively according to the proportion specified by the manufacturer, mixing, mechanically stirring for 5min, standing for 3min to reduce bubbles, and pouring into a mold specified by 6.6.1 for coating. To facilitate demolding, the mold surface may be treated with a mold release agent. The preparation of the sample is carried out 8 times or 12 times of coating, the transverse and vertical cross coating is carried out, the subsequent coating is carried out after the previous coating is dried, the interval time between the two coating is 24 hours, and the thickness of the sample reaches 1.5mm. And scraping the surface of the last coated sample, standing for 96 hours under standard conditions, and then demolding. And (3) treating the reverse side of the demolded sample upwards in a drying box at 40 ℃ for 48 hours, taking out the sample, and then placing the sample in a dryer to cool the sample to room temperature. The test piece is punched into a test piece by a slicer, the tensile strength and the elongation at break of the tensile test are not processed into a dumbbell-shaped test piece of the type I specified in GB/T528-2009, and the rupture strength and the compression strength are carried out according to the specification of GB/T17671. The trial model adopts 40 x 40 pattern160mm tricompart, one set. And moving the test piece into a standard curing chamber for curing after the test piece is molded, demolding after 1d, and continuously curing under standard conditions but not soaking in water. The test age is 28d, and the test steps and the result calculation are carried out according to the GB/T17671; chemical reagent resistance topcoat requirements: mechanically stirring the sample placed under the standard test condition for 20min according to the requirements of a manufacturer, standing for 3min to reduce bubbles, coating the sample on an iron rod, coating the sample for 6 times during preparation, wherein the thickness of the sample is equal to 1.5mm, the thickness of each coating is about 0.3mm, and the subsequent coating is carried out after the previous coating is dried completely, and the interval time between the two coatings is 6h. Standing for 96h under standard conditions until the thickness reaches the standard thickness, treating in a drying oven at 40 ℃ for 48h, taking out, and cooling in a dryer to room temperature. Measured according to GB/T9274-1988; the concrete impermeability is measured in accordance with 7.2.9 in GB 18445-2012. The water should comply with the regulations in JGJ 63. Concrete raw materials: the cement is 42.5-grade portland cement meeting the GB175-2007 regulation; the sand and the stone meet the JGJ52 regulation; the water meets the JGJ63 regulation, wherein the water-cement ratio is 0.6, and the cement consumption is 360kg/m ³ The sand rate is 38 percent, the manufacturing and the maintenance of the concrete test piece meet the requirements of GB/T50081, the concrete test piece is a cube with the size of 100mm multiplied by 100mm, and the test piece is subjected to standard maintenance for 28d. After the curing, the test piece was left for 14 days at a temperature of 20 ℃ and a relative humidity of 60%. The number and the size of the concrete samples meet the specification of the table 3

TABLE 3 number and size of concrete test pieces

The stabilization was carried out as 5.5 in JC/T902-2002. And (3) coating the sample after the chloride reduction rate is subjected to penetration depth according to the specification of JTJ275 and the alkali-resistant concrete sample is cured according to the specification of JTJ 275. And (3) saturating and overflowing the coated surface, and brushing twice, wherein the dosage of each brushing is 300 g/square meter, and the brushing interval time of the two brushing times is 7 hours. After the last 14dh pass was painted, the test was performed. Saturated Ca (OH) as specified in GB/TT16777 ₂ And 15d, taking out the test piece, and observing whether the test piece cracks or peels. Water absorptionThe rate is as given in appendix E of JTJ 275. And after the frost resistance concrete test piece is cured, coating the test piece. And (3) saturating and overflowing the coated surface, and brushing twice, wherein the dosage of each brushing is 300 g/square meter, and the brushing interval time of the two brushing times is 7 hours. After the last 14dh is brushed, the sampling can be carried out according to 6.14 in JC/984, wherein the sampling is carried out according to GB/T3186, and the standard test plate is specified according to GB/T9271; the preparation of the paint film is carried out according to GB/T1727, and the thickness of the paint film is as follows: measured according to GB/T13452.2, the paint thickness is divided by 45 μm, and the sample state regulation and the temperature and humidity of the test are specified according to GB/T9278.

Claims (6)

1. The preparation method of the high-permeability conversion rust-free anticorrosive primer is characterized by comprising the following steps of: sequentially adding butadiene, vinylidene chloride, methyl olefine acid monomer and stabilizer into a high-pressure reaction kettle, stirring and mixing uniformly, sealing a kettle cover, introducing nitrogen of 0.4 to 0.7Mpa, introducing the nitrogen for a period of time to exhaust air in the kettle, pressurizing to 0.25MPa after a sealing device, heating to 60 ℃, taking an aqueous solution in which an emulsifier with the mass fraction of 0.4 to 0.5 percent and an initiator with the mass fraction of 0.5 to 0.6 percent as an emulsion initiating solution, adding an emulsion initiating solution with the total weight of 15 percent as seed latex, after a reaction system is blue-emitting, dropwise adding the rest of the emulsion initiating solution, controlling the dropwise adding to be in 3 hours at a constant speed, then adding 45 to 48 parts of an aqueous solution of a reducing agent with the mass fraction of 4 percent, keeping the temperature at 60 ℃, stopping heating after 20 minutes of heat preservation, releasing pressure, cooling, filtering and discharging to obtain vinylidene chloride-butadiene copolymer latex with the solid content of 48 to 52 percent; step two: dispersing a mixture of natural flake graphite and lepidolite in a mixed solution of 150 parts of Tris-HCl buffer solution and 45-50 parts of absolute ethyl alcohol at a bath ratio of 1: 5~6 of 0.01mol/L, wherein the natural flake graphite and the lepidolite have the same mass, performing ultrasonic treatment for 20min to obtain a flake dispersion liquid, dispersing 5~6 parts of dopamine hydrochloride in the flake dispersion liquid, performing ultrasonic treatment for 20min, adjusting the pH value to 8.5 by using a sodium hydroxide solution with the mass fraction of 8-10%, performing magnetic stirring for 2h at 500-550r/min, performing centrifugal treatment by using a high-speed centrifuge of 8000r/min, rinsing the centrifuged product for 3 times by using deionized water, and finally placing the rinsed product in an oven at 60 ℃ and drying to constant weight to obtain flakes; and step three, adding the vinylidene chloride-butadiene copolymer latex, the flake material and the auxiliary agent into a high-speed dispersion machine, shearing and stirring at a high speed, then putting into a hopper of a conical mill, and stopping grinding when the fineness is less than 40 mu m after grinding by using a scraper fineness gauge.

2. The preparation method of the high-permeability conversion rust-free anticorrosive primer according to claim 1, wherein the third step comprises 25 to 30 parts by weight of a flake material, 76 to 90 parts by weight of vinylidene chloride-butadiene copolymer latex, and 12 to 14 parts by weight of other additives.

3. The method of claim 1, wherein the step of preparing the monomethacrylate monomer is one or more of methacryloate and methacrylate.

4. The method for preparing the high-penetration conversion rust-free anticorrosion primer as recited in claim 1, wherein the first-step emulsifier is one of hydrogenated soybean lecithin, carbomer 1312 and beta-cyclodextrin.

5. The method for preparing the high-permeability conversion rust-removing and corrosion-preventing primer as claimed in claim 1, wherein the stabilizer in the first step is N-isopropylaniline, and the weight ratio of the butadiene, the vinylidene chloride, the methacrylic acid monomer, the stabilizer and the emulsion initiation solution is 30-33: 130-135: 1~2: 0.05.

6. The method for preparing the high penetration conversion rust-free anti-corrosion primer as claimed in claim 1, wherein the first step initiator is ammonium persulfate or azobisisobutylamidine hydrochloride, and the reducing agent is one of sodium metabisulfite and vitamin C.