Modified water-based workshop primer and preparation method thereof

Abstract

The invention relates to the technical field of coatings, in particular to a modified water-based workshop primer and a preparation method thereof. The modified water-based workshop primer comprises a component A and a component B. The component A comprises the following components in parts by weight: 15-25 parts of zinc powder and 75-85 parts of pigment filler; and the component B is prepared from multi-element organic and inorganic hybrid resin of polyaniline-organic silicon-dopamine-alkali metal silicate. A coating formed by the modified water-based workshop primer provided by the invention has the characteristics of low zinc powder content, low density, high adhesive force, good weather resistance and excellent corrosion resistance. The primer can be applied to temporary protection of steel plates, the coating is applied to temporary protection of steel plates in ships and large industries, zinc oxide smoke generated in the steel plate welding and cutting process can be reduced, and harm to the body health of welding constructors is reduced.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, and in particular to a modified waterborne shop primer and a preparation method thereof. Background Art

[0002] Shop primers are widely used in the construction of ships and large industrial steel structures. Their main purpose is to provide temporary corrosion protection for steel substrates during the construction of the project.

[0003] Waterborne shop primers usually use waterborne alkali metal silicates, silica sol and zinc powder as the main raw materials. The zinc powder forms a film by forming a zinc silicate network structure through the curing reaction of zinc powder and silicate hydrolyzate. In addition to participating in the film-forming curing reaction, the zinc powder will also protect the substrate through cathodic protection.

[0004] However, the inorganic resin network structure of the waterborne shop primer after curing has the disadvantage of being brittle. In addition, the alkali metal cations will remain in the paint film after the waterborne shop primer is cured, which will cause the osmotic pressure inside the waterborne shop primer coating to increase rapidly with the penetration of the corrosive medium during the service of the coating, and make the coating more likely to fail. In order to improve the above situation, it is usually necessary to provide more zinc powder in the formula to improve the anti-corrosion performance of the coating. However, a higher zinc powder content will not only increase the coating cost and density, but also cause the steel plate coated with the shop primer to produce zinc oxide fumes during cutting and welding, which will affect the health of welding construction workers.

[0005] Polyaniline has excellent electrical conductivity and is often used to improve the electrical conductivity of coatings. It can work with zinc powder to improve the cathodic protection effect of zinc powder in coatings. However, due to the strong interaction between its chains, polyaniline is prone to agglomeration when used in coatings, thus affecting its application effect. Since both polyaniline and epoxy resin have benzene ring structures, the two are similarly miscible. Therefore, due to the compatibility of polyaniline in different base coatings, the modification and application of polyaniline in coating systems are currently mainly concentrated in epoxy coating systems.

[0006] The Chinese invention patent application with publication number CN105647378 A discloses a method for preparing a water-based aniline emulsion composite anti-corrosion coating material, wherein emulsion polymerization of aniline is carried out by continuously dropping an initiator to synthesize a polyaniline emulsion, and then the prepared polyaniline emulsion is mixed with EP-20 water-based epoxy resin to prepare a water-based polyaniline emulsion composite anti-corrosion coating material.

[0007] The Chinese invention patent application with publication number CN106496553A discloses a carbon nanotube / polyaniline composite material with electrochemical anti-corrosion effect, a preparation method and an application method. First, a carboxylated carbon nanotube / polyaniline composite material with a dendrite core-shell structure is prepared by dropping an ammonium persulfate initiator into a mixed solution of carbon nanotubes, aniline and an emulsifier. Then, the composite material is used as a filler component in the preparation of an epoxy-modified acrylate coating, thereby realizing the modification of the water-based epoxy system by polyaniline.

[0008] In the above patent application, polyaniline and resin are not connected by chemical bonds. Although polyaniline is dispersed in the water-based epoxy system, it is mainly physically dispersed by the similar compatibility of polyaniline and epoxy resin structures. Therefore, in the inorganic resin system with a large structural difference from polyaniline, polyaniline emulsion and modified polyaniline filler coated with emulsifier are still difficult to disperse. Summary of the invention

[0009] In order to solve the problems of the prior art mentioned in the above background technology, the present invention aims at the problems of unstable anti-corrosion performance and high zinc powder usage of the existing water-based shop primer, and provides a modified water-based shop primer coating, which improves the dispersibility and stability of the polyaniline structure in the water-based inorganic resin system by designing a multi-organic-inorganic hybrid resin of polyaniline-organic silicon-dopamine-alkali metal silicate as the second component, thereby improving the comprehensive performance of the water-based shop primer, and the modified coating has the characteristics of high adhesion strength, low zinc content and excellent anti-corrosion performance. The technical scheme of the present invention is as follows:

[0010] The modified water-based shop primer provided in the present application comprises a component A and a component B. In parts by weight, the component A comprises 15 to 25 parts of zinc powder and 75 to 85 parts of pigments and fillers; the component B comprises a multi-organic-inorganic hybrid resin of polyaniline-organosilicon-dopamine-alkali metal silicate.

[0011] In some embodiments, the preparation process of the polyaniline-organic silicon-dopamine-alkali metal silicate multi-organic-inorganic hybrid resin is as follows:

[0012] Preparation of polyaniline aqueous dispersion:

[0013] Under nitrogen protection, add phosphorylated polyvinyl alcohol, aniline and dilute hydrochloric acid at a reaction system temperature of -2 to 2°C and disperse them evenly; then add ammonium persulfate-dilute hydrochloric acid solution, keep warm for (5 to 7) hours, filter, wash and dry, and then disperse the product in ammonia water to obtain;

[0014] Preparation of polyaniline-organic silicon-dopamine modified acrylic emulsion:

[0015] Adding acrylic acid monomer mixture, acryl dopamine monomer, silicone monomer and crosslinking agent to the polyaniline aqueous dispersion and dispersing them uniformly; heating the reaction system to (70-80)°C under nitrogen protection, adding ammonium persulfate aqueous solution, and then keeping the temperature for reaction for (4-6) hours to obtain;

[0016] Preparation of polyaniline-organic silicon-dopamine-alkali metal silicate multi-organic inorganic hybrid resin:

[0017] In the polyaniline-organic silicon-dopamine modified acrylic emulsion, the pH value of the system is adjusted to 9-10 with N,N-dimethylethanolamine, and then mixed and dispersed uniformly; then, alkali metal silicate is added to the reaction system, and then mixed and dispersed uniformly to obtain the product.

[0018] In some embodiments, during the preparation of the polyaniline aqueous dispersion, the mass ratio of the phosphorylated polyvinyl alcohol, aniline, dilute hydrochloric acid, ammonium persulfate-dilute hydrochloric acid solution and ammonia water is 1:1:(50-60):(10-12):(230-270).

[0019] In some embodiments, the molecular structure of the phosphorylated polyvinyl alcohol is:

[0020] Wherein, n = 100 to 120;

[0021] The concentration of the dilute hydrochloric acid is (0.4-0.6) mol / L; the mass concentration of the ammonium persulfate-dilute hydrochloric acid solution is (8-12)%.

[0022] In some embodiments, during the preparation of the polyaniline-organic silicone-dopamine modified acrylic emulsion, the mass ratio of the polyaniline aqueous dispersion, the acrylic monomer mixture, the silicone monomer, the acryl dopamine monomer, the crosslinking agent, and the ammonium persulfate aqueous solution is 100:(4-6):(0.2-0.5):(0.2-0.5):(0.17-0.22):(10-20).

[0023] In some embodiments, the acrylic monomer mixture is a mixture of two or more of acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, and methyl methacrylate; the acryl dopamine monomer is one or more of 3-methacrylamide dopamine, coumaroyl dopamine, N-caffeoyl dopamine, and 3-acrylamide dopamine; the silicone monomer is one or more of vinyl trimethyl silane, vinyl triethoxy silane, dimethylethoxy vinyl silane, diphenyl vinyl ethoxy silane, methyl vinyl diethoxy silane, γ-methacryloxypropyl trimethoxy silane, and γ-methacryloxypropyl triethoxy silane; the crosslinking agent is ethylene glycol dimethacrylate; and the mass concentration of the ammonium persulfate aqueous solution is (9 to 11)%.

[0024] In some embodiments, during the preparation of the polyaniline-silicone-dopamine-alkali metal silicate multi-organic-inorganic hybrid resin, the mass ratio of the polyaniline-silicone-dopamine modified acrylic emulsion to the alkali metal silicate is 1:(2-4); wherein the alkali metal silicate is one or a combination of potassium silicate and lithium silicate, and the modulus of the alkali metal silicate is 4.0-5.0.

[0025] In some embodiments, the component B is a multi-organic-inorganic hybrid resin of polyaniline-organosilicon-dopamine-alkali metal silicate; the mass ratio of the component A to the component B is (1.2-2):1.

[0026] In some embodiments, the mesh size of the zinc powder is 500-1500 mesh; the pigment filler is one or more combinations of ferrophosphorus powder, composite iron-titanium powder, zinc phosphate, zinc oxide, titanium dioxide, talcum powder, kaolin, and red iron oxide.

[0027] The present application also provides a method for preparing the modified waterborne shop primer as described above, comprising the following preparation steps:

[0028] According to the formula of component A, zinc powder and pigments and fillers are mixed evenly to obtain the component A;

[0029] Directly pack the multi-organic-inorganic hybrid resin of polyaniline-organic silicon-dopamine-alkali metal silicate to obtain component B;

[0030] The component A and the component B are mixed in a certain weight ratio and stirred evenly to obtain the modified waterborne shop primer.

[0031] Compared with the prior art, the modified water-based shop primer provided by the present invention has the following beneficial effects:

[0032] The modified water-based shop primer provided by the present invention has a coating having low zinc powder content, low density, high adhesion, good weather resistance and excellent anti-corrosion performance. The primer can be applied to temporary protection of steel plates. The coating is used for temporary protection of steel plates in ships and large industries, which can reduce the generation of zinc oxide smoke during steel plate welding and cutting, and reduce the harm to the health of welding construction workers. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] The present invention also provides the following embodiments and comparative examples:

[0035] The modified waterborne shop primer formulas provided in the examples and comparative examples are shown in Table 1:

[0036] Table 1 Modified waterborne shop primer formula (unit: weight parts)

[0037]

[0038] The primer preparation process of specific embodiments 1-3 comprises the following steps:

[0039] (1) Weigh zinc powder and pigment filler according to the formula of component A, and mix the zinc powder and pigment filler on a shaker for 10 minutes to obtain component A;

[0040] (2) directly dispensing the polyaniline-organic silicon-dopamine-alkali metal silicate multi-organic-inorganic hybrid resin according to the amount used to obtain component B;

[0041] (3) When in use, component A and component B are mixed evenly in a specific ratio to obtain a primer, which can then be applied to the surface of the substrate.

[0042] The raw material components of the primer in specific embodiments 1-3 are selected as follows:

[0043] Example 1

[0044] The zinc powder in Example 1 is 500 mesh zinc powder, and the pigment filler is a composition prepared by mixing ferrophosphorus powder, zinc oxide and titanium dioxide in a mass ratio of 8:1:1.

[0045] The resin used in component B is a multi-organic-inorganic hybrid resin of polyaniline-organic silicon-dopamine-alkali metal silicate, and its preparation method is as follows:

[0046] (1) Preparation of polyaniline aqueous dispersion:

[0047] At -2 to 2°C and nitrogen protection conditions, add phosphated polyvinyl alcohol, aniline and dilute hydrochloric acid into a reaction container, and after uniform dispersion, drop a 10% mass concentration of ammonium persulfate-dilute hydrochloric acid solution thereinto, continue to keep warm and react for 6 hours, filter, wash with a mixture of ethanol and deionized water, and then dry in a vacuum oven at 60°C to remove the solvent, and then disperse the product in 1 mol / L ammonia water to obtain a polyaniline aqueous dispersion.

[0048] Wherein, the mass ratio of phosphorylated polyvinyl alcohol, aniline, dilute hydrochloric acid, ammonium persulfate-dilute hydrochloric acid solution and ammonia water is 1:1:50:10:270.

[0049] The molecular structural formula of the phosphorylated polyvinyl alcohol is:

[0050] Where n = 100;

[0051] The concentration of dilute hydrochloric acid is 0.5 mol / L.

[0052] (2) Preparation of polyaniline-organic silicon-dopamine modified acrylic emulsion:

[0053] Add acrylic monomer mixture, acryl dopamine monomer, silicone monomer, and crosslinking agent ethylene glycol dimethacrylate (CAS: 97-90-5) to the polyaniline aqueous dispersion and then disperse uniformly by ultrasonication. Under nitrogen protection, heat to 75°C, and drip 10% ammonium persulfate aqueous solution, then keep warm for 5 hours to obtain polyaniline-silicone-dopamine modified acrylic emulsion.

[0054] The mass ratio of polyaniline aqueous dispersion, acrylic monomer mixture, silicone monomer, acryl dopamine monomer, crosslinking agent ethylene glycol dimethacrylate, and 10% ammonium persulfate aqueous solution is 100:4:0.2:0.2:0.17:10.

[0055] Among them, the acrylic monomer mixture is a composition formed by mixing acrylic acid, methyl acrylate and ethyl acrylate in a mass ratio of 1:20:20; the silicone monomer is a composition formed by mixing vinyltrimethylsilane and vinyltriethoxysilane in a mass ratio of 1:1; and the acryl dopamine monomer is 3-methacrylamide dopamine.

[0056] (3) Preparation of polyaniline-organic silicon-dopamine-alkali metal silicate multi-organic inorganic hybrid resin:

[0057] Add polyaniline-organic silicon-dopamine modified acrylic emulsion into the reaction container, adjust the pH value of the system to 9-10 with N,N-dimethylethanolamine, and then disperse evenly at a speed of 800 r / min. Then add potassium silicate with a modulus of 4.0 into the system, and disperse for another 10 minutes to obtain a multi-organic-inorganic hybrid resin of polyaniline-organic silicon-dopamine-alkali metal silicate.

[0058] Wherein, the mass ratio of polyaniline-organic silicon-dopamine modified acrylic emulsion to potassium silicate is 1:2.

[0059] Example 2

[0060] The zinc powder in Example 2 is 800 mesh zinc powder, and the pigment filler is a composition prepared by mixing composite iron-titanium powder and zinc phosphate in a mass ratio of 1:1.

[0061] The resin used in component B is a multi-organic-inorganic hybrid resin of polyaniline-organic silicon-dopamine-alkali metal silicate, and its preparation method is as follows:

[0062] (1) Preparation of polyaniline aqueous dispersion: Phosphorylated polyvinyl alcohol, aniline and dilute hydrochloric acid were added to a reaction vessel at -2 to 2°C under nitrogen protection. After uniform dispersion, a 10% ammonium persulfate-dilute hydrochloric acid solution was added dropwise thereto. The mixture was kept warm for 6 hours. After filtration, the mixture was washed with a mixture of ethanol and deionized water, and then dried in a vacuum oven at 60°C to remove the solvent. The product was then dispersed in 1 mol / L ammonia water to obtain a polyaniline aqueous dispersion.

[0063] Among them, the mass ratio of phosphorylated polyvinyl alcohol, aniline, dilute hydrochloric acid, ammonium persulfate-dilute hydrochloric acid solution and ammonia water is 1:1:55:11:230.

[0064] The phosphorylated polyvinyl alcohol used is the same as that in Example 1; the concentration of the dilute hydrochloric acid is 0.5 mol / L.

[0065] (2) Preparation of polyaniline-organic silicon-dopamine modified acrylic emulsion:

[0066] Add acrylic monomer mixture, acryl dopamine monomer, silicone monomer, and crosslinking agent ethylene glycol dimethacrylate (CAS: 97-90-5) to the polyaniline aqueous dispersion and then disperse uniformly by ultrasonication. Under nitrogen protection, heat to 75°C, and drip 10% ammonium persulfate aqueous solution, then keep warm for 5 hours to obtain polyaniline-silicone-dopamine modified acrylic emulsion.

[0067] The mass ratio of the polyaniline aqueous dispersion, the acrylic monomer mixture, the silicone monomer, the acryl dopamine monomer, the crosslinking agent ethylene glycol dimethacrylate, and the 10% ammonium persulfate aqueous solution is 100:6:0.5:0.5:0.22:20.

[0068] The acrylic monomer mixture is a composition in which acrylic acid, butyl acrylate and methyl methacrylate are mixed in a mass ratio of 1:15:25. The silicone monomer is a composition in which dimethylethoxyvinylsilane and diphenylvinylethoxysilane are mixed in a mass ratio of 1:1. The acryl dopamine monomer is coumaroyl dopamine.

[0069] (3) Preparation of polyaniline-organic silicon-dopamine-alkali metal silicate multi-organic inorganic hybrid resin:

[0070] Add polyaniline-organic silicon-dopamine modified acrylic emulsion into the reaction container, adjust the pH value of the system to 9-10 with N,N-dimethylethanolamine, and then disperse evenly at a speed of 800r / min. Then add potassium silicate with a modulus of 4.8 into the system, and disperse for another 20 minutes to obtain a multi-organic-inorganic hybrid resin of polyaniline-organic silicon-dopamine-alkali metal silicate.

[0071] Wherein, the mass ratio of polyaniline-organic silicon-dopamine modified acrylic emulsion to potassium silicate is 1:3.

[0072] Example 3

[0073] The zinc powder in Example 3 is not 1500 mesh zinc powder, and the pigment filler is a composition prepared by mixing red iron oxide, talcum powder and kaolin in a mass ratio of 3:2:1.

[0074] The resin used in component B is a multi-organic-inorganic hybrid resin of polyaniline-organic silicon-dopamine-alkali metal silicate, and its preparation method is as follows:

[0075] (1) Preparation of polyaniline aqueous dispersion:

[0076] At -2 to 2°C and nitrogen protection conditions, add phosphated polyvinyl alcohol, aniline and dilute hydrochloric acid into a reaction container, and after uniform dispersion, drop a 10% mass concentration of ammonium persulfate-dilute hydrochloric acid solution thereinto, continue to keep warm and react for 6 hours, filter, wash with a mixture of ethanol and deionized water, and then dry in a vacuum oven at 60°C to remove the solvent, and then disperse the product in 1 mol / L ammonia water to obtain a polyaniline aqueous dispersion.

[0077] Wherein, the mass ratio of phosphorylated polyvinyl alcohol, aniline, dilute hydrochloric acid, ammonium persulfate-dilute hydrochloric acid solution and ammonia water is 1:1:60:12:250.

[0078] The phosphorylated polyvinyl alcohol used was the same as that in Example 1; the concentration of dilute hydrochloric acid was 0.5 mol / L.

[0079] (2) Preparation of polyaniline-organic silicon-dopamine modified acrylic emulsion:

[0080] Add acrylic monomer mixture, acryl dopamine monomer, silicone monomer, and crosslinking agent ethylene glycol dimethacrylate (CAS: 97-90-5) to the polyaniline aqueous dispersion and then disperse uniformly by ultrasonication. Under nitrogen protection, heat to 75°C, and drip 10% ammonium persulfate aqueous solution, then keep warm for 5 hours to obtain polyaniline-silicone-dopamine modified acrylic emulsion.

[0081] The mass ratio of the polyaniline aqueous dispersion, the acrylic monomer mixture, the silicone monomer, the acryl dopamine monomer, the crosslinking agent ethylene glycol dimethacrylate, and the 10% ammonium persulfate aqueous solution is 100:5:0.3:0.3:0.2:15.

[0082] The acrylic monomer mixture is a composition in which acrylic acid and methyl methacrylate are mixed in a mass ratio of 1:2. The silicone monomer is a composition in which γ-methacryloxypropyltrimethoxysilane and γ-methacryloxypropyltriethoxysilane are mixed in a mass ratio of 1:1. The acryl dopamine monomer is a composition in which N-caffeoyl dopamine and 3-acrylamide dopamine are mixed in a mass ratio of 1:1.

[0083] (3) Preparation of polyaniline-organic silicon-dopamine-alkali metal silicate multi-organic inorganic hybrid resin:

[0084] Add polyaniline-organic silicon-dopamine modified acrylic emulsion into the reaction container, adjust the pH value of the system to 9-10 with N,N-dimethylethanolamine, and then disperse evenly at a speed of 800 r / min. Then add lithium silicate with a modulus of 5.0 into the system, and disperse for 15 minutes to obtain a multi-organic-inorganic hybrid resin of polyaniline-organic silicon-dopamine-alkali metal silicate.

[0085] Wherein, the mass ratio of polyaniline-organic silicon-dopamine modified acrylic emulsion to lithium silicate is 1:4.

[0086] Comparative Example 1

[0087] The existing waterborne shop primer is disclosed in the Chinese invention patent application with publication number CN109943109A.

[0088] Comparative Example 2

[0089] The existing water-based shop primer disclosed in the Chinese invention patent application with publication number CN105860619A adopts a resin system of potassium silicate and lithium silicate, and the selected filler is modified with micaceous iron oxide, and the zinc powder content is greater than or equal to 40%.

[0090] The primers prepared in the above examples and comparative examples were subjected to the following performance tests, and the test results were obtained, as shown in Table 2 below:

[0091] Table 2 Performance data of examples and comparative examples

[0092]

[0093]

[0094] Analysis of the above comparative examples and embodiment data shows that:

[0095] Comparing the embodiment and comparative example 1, under the premise that the paint film thickness and weather resistance are not much different, the adhesion of the product of the embodiment of the present application is better than that of comparative example 1, and the metal zinc content is much lower than that of comparative example 1.

[0096] In conventional existing workshop primers, the higher the zinc powder content, the better the weather resistance and anti-corrosion performance. However, it can also be seen from the above data that the embodiments of the present application can achieve a service life of 6 months or more in outdoor weather resistance tests at a lower zinc powder content, indicating that the coating of the present application has excellent weather resistance and anti-corrosion performance.

[0097] Comparing the embodiment and comparative example 2, under the premise that the paint film thickness and weather resistance are not much different, the density and zinc powder content of the product of the embodiment of the present application are much lower than those of comparative example 2.

[0098] In summary, the modified waterborne shop primer provided by the present invention has at least the following design concepts and beneficial effects:

[0099] The present invention prepares an aqueous emulsion with an acrylic resin modified with silicone and dopamine functional groups as a shell layer and polyaniline as a core layer by core-shell emulsion polymerization, thereby improving the dispersibility of polyaniline in an aqueous acrylic ester system. Subsequently, through the hydrogen bond complexation of Si-O functional groups in the silicone structure and the alkali metal silicate structure, the chemical linking of the polyaniline-silicone-dopamine modified acrylic emulsion and the inorganic alkali metal silicate is achieved, thereby obtaining a novel organic-inorganic hybrid resin.

[0100] Among them, due to the introduction of polyaniline segments, the conductivity of the hybrid resin is greatly improved. In the water-based workshop primer, a conductive channel can be formed between zinc powders, which improves the cathodic protection effect of zinc powders and the utilization rate of zinc powders, thereby reducing the amount of zinc powders used. In addition, since structural units containing dopamine are also introduced into the resin structure, it can complex with iron ions and realize self-repair of the coating after the cathodic protection of zinc powders fails.

[0101] In summary, the modified water-based shop primer provided by the present invention has a coating having low zinc powder content, low density, high adhesion, good weather resistance and excellent anti-corrosion performance. The primer can be applied to temporary protection of steel plates. The coating is used for temporary protection of steel plates in ships and large industries, which can reduce the generation of zinc oxide smoke during steel plate welding and cutting, and reduce the harm to the health of welding construction workers.

[0102] The main performance indicators of the modified water-based shop primer provided in the embodiments of the present application are shown in Table 3 below:

[0103] Table 3 Main technical indicators of modified waterborne shop primer

[0104] project Technical indicators Detection Methods Film thickness, μm 20～25 GB / T 6747 Density, kg / L ≤2.0 GB / T 6750 Surface drying time, min ≤5 GB / T 1728 Adhesion, Grade ≤1 GB / T 9286 Weather resistance, months ≥6 GB / T 9276 Metal zinc content, % ≤20 GB / T 6890

[0105] It should be noted that:

[0106] In this article, “~” is used to indicate a numerical range, and the range indicated by this expression includes two endpoint values.

[0107] In addition to the actual selections embodied in the above specific embodiments, the above formulation ranges may be used in the specific implementation of the present invention, including but not limited to the above embodiment schemes.

[0108] The specific parameters or some commonly used reagents or raw materials in the above embodiments are specific embodiments or preferred embodiments of the present invention, but are not intended to limit the present invention. Those skilled in the art may make adaptive adjustments within the scope of the present invention.

[0109] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A modified waterborne shop primer comprising component A and component B, characterized in that: In parts by weight, the component A comprises 15 to 25 parts of zinc powder and 75 to 85 parts of pigments and fillers; The second component comprises a multi-organic and inorganic hybrid resin of polyaniline-organosilicon-dopamine-alkali metal silicate.

2. The modified waterborne shop primer according to claim 1, characterized in that: The preparation process of the polyaniline-organic silicon-dopamine-alkali metal silicate multi-organic inorganic hybrid resin is as follows: Preparation of polyaniline aqueous dispersion: Under nitrogen protection, add phosphorylated polyvinyl alcohol, aniline and dilute hydrochloric acid at a reaction system temperature of -2 to 2°C and disperse them evenly; then add ammonium persulfate-dilute hydrochloric acid solution, keep warm for (5 to 7) hours, filter, wash and dry, and then disperse the product in ammonia water to obtain; Preparation of polyaniline-organic silicon-dopamine modified acrylic emulsion: Adding acrylic acid monomer mixture, acryl dopamine monomer, silicone monomer and crosslinking agent to the polyaniline aqueous dispersion and dispersing them uniformly; heating the reaction system to (70-80)°C under nitrogen protection, adding ammonium persulfate aqueous solution, and then keeping the temperature for reaction for (4-6) hours to obtain; Preparation of polyaniline-organic silicon-dopamine-alkali metal silicate multi-organic inorganic hybrid resin: In the polyaniline-organic silicon-dopamine modified acrylic emulsion, the pH value of the system is adjusted to 9-10 with N,N-dimethylethanolamine, and then mixed and dispersed uniformly; then, alkali metal silicate is added to the reaction system, and then mixed and dispersed uniformly to obtain the product.

3. The modified waterborne shop primer according to claim 2, characterized in that: During the preparation of the polyaniline aqueous dispersion, the mass ratio of the phosphorylated polyvinyl alcohol, aniline, dilute hydrochloric acid, ammonium persulfate-dilute hydrochloric acid solution and ammonia water is 1:1:(50-60):(10-12):(230-270).

4. The modified waterborne shop primer according to claim 2 or 3, characterized in that: The molecular structural formula of the phosphorylated polyvinyl alcohol is: Wherein, n = 100 to 120; The concentration of the dilute hydrochloric acid is (0.4-0.6) mol / L; the mass concentration of the ammonium persulfate-dilute hydrochloric acid solution is (8-12)%.

5. The modified waterborne shop primer according to claim 2, characterized in that: In the preparation process of the polyaniline-organic silicon-dopamine modified acrylic emulsion, the mass ratio of the polyaniline aqueous dispersion, the acrylic monomer mixture, the organic silicon monomer, the acryl dopamine monomer, the crosslinking agent, and the ammonium persulfate aqueous solution is 100:(4-6):(0.2-0.5):(0.2-0.5):(0.17-0.22):(10-20).

6. The modified waterborne shop primer according to claim 2 or 5, characterized in that: The acrylic monomer mixture is a mixture of two or more of acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, and methyl methacrylate; The acryl dopamine monomer is one or more of 3-methacrylamide dopamine, coumaroyl dopamine, N-caffeoyl dopamine, and 3-acrylamide dopamine; The organosilicon monomer is one or more of vinyl trimethyl silane, vinyl triethoxy silane, dimethyl ethoxy vinyl silane, diphenyl vinyl ethoxy silane, methyl vinyl diethoxy silane, γ-methacryloxypropyl trimethoxy silane, and γ-methacryloxypropyl triethoxy silane; The cross-linking agent is ethylene glycol dimethacrylate; The mass concentration of the ammonium persulfate aqueous solution is (9-11)%.

7. The modified waterborne shop primer according to claim 2, characterized in that: In the preparation process of the polyaniline-organic silicon-dopamine-alkali metal silicate multi-organic-inorganic hybrid resin, the mass ratio of the polyaniline-organic silicon-dopamine modified acrylic emulsion to the alkali metal silicate is 1:(2-4); The alkali metal silicate is one or a combination of potassium silicate and lithium silicate, and the modulus of the alkali metal silicate is 4.0-5.

0.

8. The modified waterborne shop primer according to claim 1, characterized in that: The second component is a multi-organic and inorganic hybrid resin of polyaniline-organic silicon-dopamine-alkali metal silicate; The mass ratio of the component A to the component B is (1.2-2):

1.

9. The modified waterborne shop primer according to claim 1, characterized in that: The mesh size of the zinc powder is 500-1500 mesh; The pigment filler is one or more combinations of ferrophosphorus powder, composite iron-titanium powder, zinc phosphate, zinc oxide, titanium dioxide, talcum powder, kaolin, and red iron oxide.

10. A method for preparing a modified waterborne shop primer as claimed in any one of claims 1 to 9, characterized in that: The method comprises the following preparation steps: According to the formula of component A, zinc powder and pigments and fillers are mixed evenly to obtain the component A; Directly pack the multi-organic-inorganic hybrid resin of polyaniline-organic silicon-dopamine-alkali metal silicate to obtain component B; The component A and the component B are mixed in a certain weight ratio and stirred evenly to obtain the modified waterborne shop primer.

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