A modified waterborne shop primer and its preparation method

Abstract

This invention relates to the field of coating technology, and particularly to a modified waterborne shop primer and its preparation method. The modified waterborne shop primer comprises component A and component B. By weight, component A comprises 15-25 parts zinc powder and 75-85 parts pigments and fillers; component B comprises a multi-component organic-inorganic hybrid resin of polyaniline-organosilicon-dopamine-alkali metal silicate. The modified waterborne shop primer provided by this invention forms a coating with low zinc powder content, low density, high adhesion, good weather resistance, and excellent anti-corrosion performance. This primer can be applied to the temporary protection of steel plates. Using this coating for temporary protection of steel plates in shipbuilding and large-scale industrial applications can reduce zinc oxide fumes generated during steel plate welding and cutting, and reduce the health hazards to welding workers.

Description

Technical Field

[0001] This invention relates to the field of coatings technology, and in particular to a modified water-based shop primer and its preparation method. Background Technology

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

[0003] Water-based shop primers typically use water-based alkali metal silicates, silica sol, and zinc powder as main raw materials. A zinc silicate network structure is formed through a curing reaction between zinc powder and silicate hydrolysates to create a film. In addition to participating in the film-forming and curing reaction, the zinc powder also provides cathodic protection for the substrate.

[0004] However, the inorganic resin network structure of water-based shop primers after curing has a significant drawback: high brittleness. Furthermore, alkali metal cations remain in the paint film after curing, leading to a rapid increase in osmotic pressure within the coating during service as corrosive media penetrate, making the coating more prone to failure. To mitigate this, a higher zinc powder content is typically added to the formulation to improve corrosion resistance. However, a higher zinc powder content not only increases coating cost and density but also generates zinc oxide fumes during cutting and welding of steel plates coated with shop primer, negatively impacting the health of welding workers.

[0005] Polyaniline possesses excellent electrical conductivity and is often used to improve the conductivity of coatings. In synergy with zinc powder, it can enhance the cathodic protection effect of zinc powder in coatings. However, due to its extremely strong interchain interactions, polyaniline is prone to agglomeration when used in coatings, thus affecting its application performance. Since both polyaniline and epoxy resins possess benzene ring structures, they exhibit similar miscibility. Therefore, limited by the compatibility of polyaniline with different substrates, current modifications and applications of polyaniline in coating systems are primarily focused on epoxy coating systems.

[0006] Chinese invention patent application with publication number CN105647378 A discloses a method for preparing a waterborne aniline emulsion composite anti-corrosion coating material. The method involves emulsion polymerization of aniline by continuously adding an initiator to synthesize a polyaniline emulsion, and then mixing the prepared polyaniline emulsion with EP-20 waterborne epoxy resin to prepare a waterborne polyaniline emulsion composite anti-corrosion coating material.

[0007] Chinese invention patent application CN106496553A discloses a carbon nanotube / polyaniline composite material with electrochemical anti-corrosion properties, its preparation method, and its application method. First, a dendritic core-shell structured carboxylated carbon nanotube / polyaniline composite material is prepared by adding ammonium persulfate initiator to a mixture of carbon nanotubes, aniline, and emulsifier. Then, this composite material is used as a filler component in the preparation of epoxy-modified acrylic coatings, thereby realizing the modification of waterborne epoxy systems by polyaniline.

[0008] In the aforementioned patent application, polyaniline and resin are not chemically bonded. Although polyaniline is dispersed in the aqueous epoxy system, this dispersion is mainly achieved through physical dispersion due to the structural similarity and compatibility between polyaniline and epoxy resin. Therefore, in inorganic resin systems with structures significantly different from polyaniline, polyaniline emulsions and modified polyaniline fillers coated with emulsifiers remain difficult to disperse. Summary of the Invention

[0009] To address the problems of the prior art mentioned in the background section, this invention provides a modified waterborne shop primer coating, specifically targeting the issues of unstable anti-corrosion performance and high zinc powder content in existing waterborne shop primers. This modified coating utilizes a multi-component organic-inorganic hybrid resin (polyaniline-organosilicon-dopamine-alkali metal silicate) as its B component, improving the dispersibility and stability of the polyaniline structure within the waterborne inorganic resin system. This enhances the overall performance of the waterborne shop primer, resulting in a modified coating characterized by high adhesion strength, low zinc content, and excellent anti-corrosion properties. The technical solution of this invention is as follows:

[0010] The modified waterborne shop primer provided in this application includes component A and component B. By weight, component A includes 15-25 parts of zinc powder and 75-85 parts of pigments and fillers; component B includes a multi-component organic-inorganic hybrid resin of polyaniline-organosilicon-dopamine-alkali metal silicate.

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

[0012] Preparation of polyaniline aqueous dispersion:

[0013] Under nitrogen protection, phosphorylated polyvinyl alcohol, aniline, and dilute hydrochloric acid were added and dispersed evenly at a reaction system temperature of -2 to 2℃. Then, ammonium persulfate-dilute hydrochloric acid solution was added, and the reaction was maintained at this temperature for (5 to 7) hours. After filtration, washing, and drying, the product was dispersed in ammonia water to obtain the final product.

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

[0015] An acrylic monomer mixture, acryloyl dopamine monomer, organosilicon monomer, and crosslinking agent are added to the polyaniline aqueous dispersion and dispersed evenly. Under nitrogen protection, the reaction system is heated to (70-80)℃, and an ammonium persulfate aqueous solution is added. The reaction is then maintained at this temperature for (4-6) hours to obtain the final product.

[0016] Preparation of multi-component organic-inorganic hybrid resins of polyaniline-organosilicon-dopamine-alkali metal silicates:

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

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

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

[0020] Where 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-organosilicon-dopamine modified acrylic emulsion, the mass ratio of polyaniline aqueous dispersion, acrylic monomer mixture, organosilicon monomer, acryloyldopamine monomer, crosslinking agent, and 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 acrylamide dopamine monomer is one or more of 3-methacrylamidodopamine, coumaroyl dopamine, N-caffeoyl dopamine, and 3-acrylamidodopamine; the organosilicon monomer is one or more of vinyltrimethylsilane, vinyltriethoxysilane, dimethylethoxyvinylsilane, diphenylvinylethoxysilane, methylvinyldiethoxysilane, γ-methacryloxypropyltrimethoxysilane, and γ-methacryloxypropyltriethoxysilane; the crosslinking agent is ethylene glycol dimethacrylate; and the mass concentration of the ammonium persulfate aqueous solution is (9-11)%.

[0024] In some embodiments, during the preparation of the polyaniline-organosilicon-dopamine-alkali metal silicate multi-component organic-inorganic hybrid resin, the mass ratio of the polyaniline-organosilicon-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, component B is a multi-component organic-inorganic hybrid resin of polyaniline-organosilicon-dopamine-alkali metal silicate; the mass ratio of component A to component B is (1.2-2):1.

[0026] In some embodiments, the zinc powder has a mesh size of 500 to 1500 mesh; the pigments and fillers are one or more combinations of ferrophosphate powder, composite iron-titanium powder, zinc phosphate, zinc oxide, titanium dioxide, talc, kaolin, and iron oxide red.

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

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

[0029] Component B is obtained by directly dispensing a multi-component organic-inorganic hybrid resin of polyaniline-organosilicon-dopamine-alkali metal silicate.

[0030] The modified water-based shop primer is obtained by mixing and stirring the components A and B in a certain weight ratio.

[0031] The modified water-based shop primer provided by this invention has the following advantages compared with existing technologies:

[0032] The modified water-based shop primer provided by this invention forms a coating with low zinc powder content, low density, high adhesion, good weather resistance, and excellent anti-corrosion performance. This primer can be used for temporary protection of steel plates. Applying this coating to temporary protection of steel plates in shipbuilding and large-scale industrial applications can reduce zinc oxide fumes generated during steel plate welding and cutting, and reduce the health hazards to welding workers. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort 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 formulations provided in the examples and comparative examples are shown in Table 1:

[0036] Table 1. Formulation of modified waterborne shop primer (unit: parts by weight)

[0037]

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

[0039] (1) Weigh out zinc powder and pigments and fillers according to the formula of component A, and mix zinc powder and pigments and fillers in a shaker for 10 minutes to obtain component A;

[0040] (2) Based on the dosage, directly dispense the polyaniline-organosilicon-dopamine-alkali metal silicate multi-component organic-inorganic hybrid resin to obtain component B;

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

[0042] The selection of raw material components for the primer in specific embodiments 1-3:

[0043] Example 1

[0044] In Example 1, the zinc powder was 500 mesh zinc powder, and the pigments and fillers were a mixture of 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-component organic-inorganic hybrid resin of polyaniline-organosilicon-dopamine-alkali metal silicate, and its preparation method is as follows:

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

[0047] Under nitrogen protection conditions of -2 to 2℃, phosphorylated polyvinyl alcohol, aniline and dilute hydrochloric acid were added to the reaction vessel and dispersed evenly. Then, a 10% ammonium persulfate-dilute hydrochloric acid solution was added dropwise and the reaction was continued at this temperature for 6 hours. After filtration, the product was washed with a mixture of ethanol and deionized water and then dried in a vacuum oven at 60℃ to remove the solvent. Finally, the product was dispersed in 1 mol / L ammonia water to obtain a polyaniline aqueous dispersion.

[0048] 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 the dilute hydrochloric acid is 0.5 mol / L.

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

[0053] A mixture of acrylic monomers, acryloyl dopamine monomer, organosilicon monomer, and crosslinking agent ethylene glycol dimethacrylate (CAS: 97-90-5) were added to a polyaniline aqueous dispersion, followed by ultrasonic dispersion. Under nitrogen protection, the mixture was heated to 75°C, and a 10% (w / w) ammonium persulfate aqueous solution was added dropwise. The mixture was then kept at this temperature for 5 hours to obtain a polyaniline-organosilicone-dopamine modified acrylic emulsion.

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

[0055] The acrylic monomer mixture is a composition of acrylic acid, methyl acrylate and ethyl acrylate mixed in a mass ratio of 1:20:20; the organosilicon monomer is a composition of vinyltrimethylsilane and vinyltriethoxysilane mixed in a mass ratio of 1:1; and the acryloyl dopamine monomer is 3-methylacrylamidodopamine.

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

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

[0058] The mass ratio of polyaniline-organosilicon-dopamine modified acrylic emulsion to potassium silicate is 1:2.

[0059] Example 2

[0060] In Example 2, the zinc powder was 800 mesh zinc powder, and the pigments and fillers were a mixture of composite iron-titanium powder and zinc phosphate in a mass ratio of 1:1.

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

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

[0063] 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 was the same as in Example 1; the concentration of the dilute hydrochloric acid was 0.5 mol / L.

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

[0066] A mixture of acrylic monomers, acryloyl dopamine monomer, organosilicon monomer, and crosslinking agent ethylene glycol dimethacrylate (CAS: 97-90-5) were added to a polyaniline aqueous dispersion, followed by ultrasonic dispersion. Under nitrogen protection, the mixture was heated to 75°C, and a 10% (w / w) ammonium persulfate aqueous solution was added dropwise. The mixture was then kept at this temperature for 5 hours to obtain a polyaniline-organosilicone-dopamine modified acrylic emulsion.

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

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

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

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

[0071] The mass ratio of polyaniline-organosilicon-dopamine modified acrylic emulsion to potassium silicate is 1:3.

[0072] Example 3

[0073] The zinc powder in Example 3 is 1500 mesh zinc powder, and the pigment and filler are a mixture of iron oxide red, talc powder and kaolin in a mass ratio of 3:2:1.

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

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

[0076] Under nitrogen protection conditions of -2 to 2℃, phosphorylated polyvinyl alcohol, aniline and dilute hydrochloric acid were added to the reaction vessel and dispersed evenly. Then, a 10% ammonium persulfate-dilute hydrochloric acid solution was added dropwise and the reaction was continued at this temperature for 6 hours. After filtration, the product was washed with a mixture of ethanol and deionized water and then dried in a vacuum oven at 60℃ to remove the solvent. Finally, the product was dispersed in 1 mol / L ammonia water to obtain a polyaniline aqueous dispersion.

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

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

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

[0080] A mixture of acrylic monomers, acryloyl dopamine monomer, organosilicon monomer, and crosslinking agent ethylene glycol dimethacrylate (CAS: 97-90-5) were added to a polyaniline aqueous dispersion, followed by ultrasonic dispersion. Under nitrogen protection, the mixture was heated to 75°C, and a 10% (w / w) ammonium persulfate aqueous solution was added dropwise. The mixture was then kept at this temperature for 5 hours to obtain a polyaniline-organosilicone-dopamine modified acrylic emulsion.

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

[0082] The acrylic monomer mixture is a composition of acrylic acid and methyl methacrylate mixed in a mass ratio of 1:2. The organosilicon monomer is a composition of γ-methacryloyloxypropyltrimethoxysilane and γ-methacryloyloxypropyltriethoxysilane mixed in a mass ratio of 1:1. The acryloyl dopamine monomer is a composition of N-caffeoyl dopamine and 3-acrylamido dopamine mixed in a mass ratio of 1:1.

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

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

[0085] The mass ratio of polyaniline-organosilicon-dopamine modified acrylic emulsion to lithium silicate is 1:4.

[0086] Comparative Example 1

[0087] The existing water-based shop primer disclosed in Chinese invention patent application CN109943109A.

[0088] Comparative Example 2

[0089] The existing water-based shop primer disclosed in Chinese invention patent application CN105860619A uses a resin system of potassium silicate and lithium silicate, and the filler is modified with mica iron oxide, with a zinc powder content of ≥40%.

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

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

[0092]

[0093] Analysis of the comparative and example data above shows that:

[0094] Comparing the embodiments and Comparative Example 1, under the premise that the film thickness and weather resistance are not much different, the adhesion of the product of this application embodiment is better than that of Comparative Example 1, and the zinc content is much lower than that of Comparative Example 1.

[0095] In traditional shop primers, higher zinc powder content generally results in better weather resistance and corrosion resistance. However, the data above also shows that the embodiments of this application, even with a relatively low zinc powder content, can achieve a service life of 6 months or more in outdoor weathering tests, indicating that the coating of this application has excellent weather resistance and corrosion resistance.

[0096] Comparing the embodiments and Comparative Example 2, under the premise that the film thickness and weather resistance are not much different, the density and zinc powder content of the product of this application embodiment are much lower than those of Comparative Example 2.

[0097] In summary, the modified water-based shop primer provided by this invention has at least the following design concept and beneficial effects:

[0098] This invention utilizes a core-shell emulsion polymerization method to prepare an aqueous emulsion with an acrylic resin modified with organosilicon and dopamine functional groups as the shell and polyaniline as the core, thereby improving the dispersibility of polyaniline in aqueous acrylate systems. Subsequently, through hydrogen bonding complexation of Si-O functional groups in the organosilicon and alkali metal silicate structures, a chemical linking of the polyaniline-organosilicon-dopamine modified acrylic emulsion with inorganic alkali metal silicates was achieved, resulting in a novel organic-inorganic hybrid resin.

[0099] The introduction of polyaniline segments significantly enhances the conductivity of the hybrid resin. In water-based workshop primers, it can form conductive channels between zinc powder particles, improving the cathodic protection effect and utilization rate of the zinc powder, thereby reducing the amount of zinc powder used. Furthermore, the inclusion of dopamine-containing structural units in the resin structure allows for complexation with iron ions, enabling self-repair of the coating after the cathodic protection of the zinc powder fails.

[0100] In summary, the modified water-based shop primer provided by this invention forms a coating with low zinc powder content, low density, high adhesion, good weather resistance, and excellent anti-corrosion performance. This primer can be used for temporary protection of steel plates. Applying this coating to temporary protection of steel plates in shipbuilding and large-scale industrial applications can reduce zinc oxide fumes generated during steel plate welding and cutting, and reduce the harm to the health of welding workers.

[0101] The main performance indicators of the modified waterborne shop primer provided in the specific embodiments of this application are shown in Table 3 below:

[0102] Table 3 Main Technical Indicators of Modified Waterborne Shop Primer

[0103]

[0104] It should be noted that:

[0105] In this article, “~” is used to represent the range of values, and the range of values ​​represented by this expression includes two endpoint values.

[0106] In addition to the specific choices shown in the above embodiments, the above-described formulation range can be used in the specific implementation of the present invention, including but not limited to the above-described embodiment schemes.

[0107] The specific parameters or some commonly used reagents or raw materials in the above embodiments are specific or preferred embodiments under the concept of the present invention, and are not intended to limit it; those skilled in the art can make adaptive adjustments within the concept and protection scope of the present invention.

[0108] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions 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 a Part A and a Part B, characterized in that: The A component includes zinc powder 15-25 parts by weight, pigment and filler 75-85 parts by weight; The B component includes a polyphenylamine-silicone-dopamine-alkali metal silicate multi-element organic-inorganic hybrid resin; The polyphenylamine-silicone-dopamine-alkali metal silicate multi-element organic-inorganic hybrid resin is prepared as follows: Preparation of the polyphenylamine water dispersion: Under the condition of nitrogen protection, the reaction system temperature is -2-2℃, and the phosphonated polyvinyl alcohol, aniline and dilute hydrochloric acid are uniformly dispersed. Then, the ammonium persulfate-dilute hydrochloric acid solution is added, and the reaction is kept for (5-7) h. After filtration, washing and drying, the product is dispersed in ammonia water to obtain the polyphenylamine water dispersion; In the preparation process of the polyphenylamine water dispersion, the mass ratio of the phosphonated polyvinyl alcohol, aniline, dilute hydrochloric acid, ammonium persulfate-dilute hydrochloric acid solution and ammonia water is 1:1:(50-60):(10-12):(230-270); The molecular structure of the phosphonated polyvinyl alcohol is as follows: , wherein n = 100-120; The concentration of the dilute hydrochloric acid is (0.4-0.6) mol / L, and the mass concentration of the ammonium persulfate-dilute hydrochloric acid solution is (8-12) %; Preparation of the polyphenylamine-silicone-dopamine modified acrylic emulsion: The polyphenylamine water dispersion, acrylic monomer mixture, silicone monomer, acryloyl dopamine monomer and crosslinking agent are uniformly dispersed. Under the condition of nitrogen protection, the reaction system is heated to (70-80) ℃, and the ammonium persulfate aqueous solution is added. Then, the reaction is kept for (4-6) h to obtain the polyphenylamine-silicone-dopamine modified acrylic emulsion. In the preparation process of the polyphenylamine-silicone-dopamine modified acrylic emulsion, the mass ratio of the polyphenylamine water dispersion, acrylic monomer mixture, silicone monomer, acryloyl dopamine monomer, crosslinking agent and ammonium persulfate aqueous solution is 100:(4-6):(0.2-0.5):(0.2-0.5):(0.17-0.22):(10-20). Preparation of the polyphenylamine-silicone-dopamine-alkali metal silicate multi-element organic-inorganic hybrid resin: In the polyphenylamine-silicone-dopamine modified acrylic emulsion, the pH of the system is adjusted to 9-10 by using N,N-dimethyl ethanolamine, and then uniformly mixed and dispersed. Then, the alkali metal silicate is added to the reaction system, and uniformly mixed and dispersed to obtain the polyphenylamine-silicone-dopamine-alkali metal silicate multi-element organic-inorganic hybrid resin. In the preparation process of the polyphenylamine-silicone-dopamine-alkali metal silicate multi-element organic-inorganic hybrid resin, the mass ratio of the polyphenylamine-silicone-dopamine modified acrylic emulsion and 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.

2. The modified water-based shop primer according to claim 1, 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 acryloyl dopamine monomer is one or a combination of 3-methacrylamidodopamine, coumaroyldopamine, N-caffeoyldopamine and 3-acrylamidodopamine. The organic silicon monomer is one or more combinations of vinyltrimethylsilane, vinyltriethoxysilane, dimethylethoxyvinylsilane, diphenylvinylethoxysilane, methylvinyl-diethoxysilane, gamma-methacryloyloxypropyltrimethoxysilane, and gamma-methacryloyloxypropyltriethoxysilane; The crosslinking agent is ethylene glycol dimethacrylate; The mass concentration of the ammonium persulfate aqueous solution is (9-11) %.

3. The modified water-based shop primer according to claim 1, characterized in that: The B component is a polybasic organic-inorganic hybrid resin of polyaniline-silicone-dopamine-alkali metal silicate; The mass ratio of the A component to the B component is (1.2-2):

1.

4. The modified water-based shop primer according to claim 1, characterized in that: The zinc powder has a mesh size of 500-1500 mesh; The color filler is one or more combinations of phosphorus iron powder, composite iron-titanium powder, zinc phosphate, zinc oxide, titanium dioxide, talc, kaolin, and red iron oxide.

5. A process for the preparation of a modified aqueous shop primer according to any one of claims 1 to 4, characterized in that The preparation steps include: Mixing the zinc powder and the color filler according to the A component formula to obtain the A component; Directly packaging the polybasic organic-inorganic hybrid resin of polyaniline-silicone-dopamine-alkali metal silicate to obtain the B component; Mixing the A component and the B component according to a certain weight ratio and stirring uniformly to obtain the modified water-based shop primer.

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