Waterborne epoxy zinc-rich primer and preparation method thereof

Abstract

The invention discloses waterborne epoxy zinc-rich primer and a preparation method, and belongs to the technical field of primer, the waterborne epoxy zinc-rich primer comprises a component A and a component B, and the weight ratio of the component A to the component B is (15-20): 1; the component A is prepared from 10 to 15 parts of resin, 0.5 to 1 part of coupling agent, 0.5 to 1 part of defoaming agent, 0.1 to 1 part of wetting agent, 0.1 to 1 part of thickening agent, 1 to 2 parts of pigment, 65 to 85 parts of zinc powder and 8 to 10 parts of first water-based solvent; the component B comprises 30-60 parts of a modified amine curing agent, 10-20 parts of a second aqueous solvent, 20-30 parts of deionized water and 3-5 parts of a flash rust inhibitor; the preparation method comprises the following steps: sequentially adding the first water-based solvent and the resin into a dispersion kettle, adding the defoaming agent, the pigment, the compound of titanium ditelluride and the nano material and the zinc powder, sequentially adding the defoaming agent, the wetting agent, the coupling agent, the thickening agent and the first water-based solvent, adjusting the viscosity, and filtering to obtain the component A; sequentially adding a modified amine curing agent, a second aqueous solvent, deionized water and an anti-flash-rust agent into a dispersion kettle, and dispersing to obtain a component B; and finally, uniformly mixing the component A and the component B to obtain the primer.

Description

Technical Field

[0001] The invention belongs to the field of epoxy primers, and in particular relates to a water-based epoxy zinc-rich primer and a preparation method thereof. Background Art

[0002] Waterborne epoxy zinc-rich primers are usually used as basecoats in conjunction with topcoats and tiecoats to provide comprehensive protection for metal substrates. However, in the marine sector, existing waterborne epoxy zinc-rich primers still have some defects: the interfacial bonding between the coating and the substrate is weak, making it prone to peeling or delamination in high-humidity or high-salt environments; zinc powder easily agglomerates and is unevenly distributed, affecting the cathodic protection effect and reducing the overall protective effectiveness of the coating; topcoats and tiecoats are easily damaged by mechanical damage, ultraviolet radiation, chemical erosion, etc., and the attachment of microorganisms after damage will accelerate the destruction of the primer by seawater and the corrosive ions therein. Without effective antifouling measures, metal structures will quickly suffer from corrosion and biofouling, greatly shortening the service life of the facilities and increasing maintenance costs and safety risks. Therefore, the development of a waterborne epoxy zinc-rich primer with strong coating adhesion, good zinc powder dispersion stability, excellent corrosion resistance, and the ability to achieve antifouling and long-term anticorrosion has become an urgent need in the industry. Summary of the Invention

[0003] Based on the above problems, the present invention provides a water-based epoxy zinc-rich primer and a preparation method thereof. The water-based epoxy zinc-rich primer has a long application period, good zinc powder dispersion stability, good coating flexibility, high impact resistance, excellent water resistance and corrosion resistance, certain anti-fouling properties, strong adhesion in high humidity and high heat environments, and is suitable for the shipbuilding field.

[0004] In order to achieve the above object, the present invention provides a water-based epoxy zinc-rich primer, comprising a component A and a component B, wherein the weight ratio of the component A to the component B is 15-20:1, and the component A comprises, calculated in parts by weight, 10-15 parts of a resin, 0.5-1 part of a coupling agent, 0.5-1 part of a defoamer, 0.1-1 part of a wetting agent, 0.1-1 part of a thickener, 1-2 parts of a pigment, 65-85 parts of zinc powder, and 8-10 parts of a first aqueous solvent; Calculated by weight, the B component includes 30-60 parts of a modified amine curing agent, 10-20 parts of a second aqueous solvent, 20-30 parts of deionized water, and 3-5 parts of an anti-flash rust agent; The resin is a compound of bisphenol A liquid epoxy resin and styrene-maleic anhydride resin, and the epoxy equivalent of the bisphenol A liquid epoxy resin is 185-215 g / eq; The modified amine curing agent is a compound of a modified alicyclic amine curing agent and a modified polyether amine curing agent.

[0005] As a preferred embodiment, the weight ratio of the bisphenol A liquid epoxy resin to the styrene-maleic anhydride resin is 8:1-2; the bisphenol A liquid epoxy resin is selected from at least one of EPIKOTE 3510-W-60A, Epikote WD-510A, or Epikote WD-512A; and the styrene-maleic anhydride resin is selected from at least one of SMA 2025, Polyscope XIRAN 6000, or Polyscope XIRAN 9000.

[0006] As a preferred embodiment, the coupling agent is a compound of a triaminosilane coupling agent and succinic acid mono-2-(2-acryloyloxy) hydroxyethanol, the weight ratio of the triaminosilane coupling agent to succinic acid mono-2-(2-acryloyloxy) hydroxyethanol is 1:0.5~1.5, and the triaminosilane coupling agent is selected from at least one of Dynasylan® TRIAMO and QX-618.

[0007] As a preferred embodiment, the weight ratio of the modified alicyclic amine curing agent to the modified polyetheramine curing agent is 3 to 4:1, the modified alicyclic amine curing agent is selected from at least one of MH-6618 and ZY-S078, and the modified polyetheramine curing agent is selected from at least one of R-2257K, R-2257D, and JEFFAMINE D-2010.

[0008] As a preferred embodiment, the defoaming agent is a silicone defoaming agent, and the silicone defoaming agent is selected from at least one of Dow Corning® AFE-1510 and TEGO® Foamex 810.

[0009] As a preferred embodiment, the wetting agent is an organosilicon twin structure surfactant, and the organosilicon twin structure surfactant is selected from at least one of TEGO Twin 4100, TEGO Twin 4000, and BSM-14100.

[0010] As a preferred embodiment, the thickener is selected from at least one of RHEOVIS® PE 1331, RHEOLATE® 350, TEGO® ViscoPlus 3030 or HOSTACERIN® WO 30; the flash rust inhibitor is selected from at least one of ANTICOARCH100S, NALZIN® FA 180, and Coadd™ FR-6018; the pigment is selected from at least one of mica iron oxide, zinc phosphate, zinc molybdate, calcium molybdate, red iron oxide, and yellow iron oxide; and the first aqueous solvent and the second aqueous solvent are respectively selected from at least one of isopropyl alcohol, ethylene glycol butyl ether, and propylene glycol methyl ether.

[0011] As a preferred embodiment, the component A further comprises 1 to 3 parts of a compound of titanium ditelluride and a nanomaterial, wherein the weight ratio of the nanomaterial to titanium ditelluride in the compound is 7 to 9:1, and the nanomaterial is selected from at least one of nanographene, carbon nanotubes, nanosilicon dioxide, and nanocalcium carbonate.

[0012] The present invention also provides a method for preparing a water-based epoxy zinc-rich primer, comprising the following specific steps: S1: Add the first aqueous solvent and the resin into a dispersion kettle in sequence and disperse for 15 to 30 minutes; S2: Add the defoamer into the dispersion kettle and disperse for 5 to 10 minutes; S3: Add pigment, titanium ditelluride and nanomaterial compound under stirring and disperse for 15 to 30 minutes; S4: Add zinc powder while stirring and disperse for 30-50 minutes; S5: Add defoamer, wetting agent, and coupling agent and disperse for 20-30 minutes; S6: Using a thickener and the first aqueous solvent, adjusting the viscosity to 90-100 KU, and filtering through a 150-mesh filter to obtain component A; S7: Add the modified amine curing agent, the second aqueous solvent, deionized water, and the flash rust preventer into a dispersion kettle in sequence, and disperse for 15 to 30 minutes to obtain component B; S8: Evenly mix the component A and the component B to obtain the waterborne epoxy zinc-rich primer.

[0013] As a preferred embodiment, in step S1, the resin is a bisphenol A liquid epoxy resin and a styrene-maleic anhydride resin in a weight ratio of 8:1-2, and the two are sequentially put into a dispersion kettle for dispersion; in step S3, the nanomaterial and titanium ditelluride are placed in a ball mill at a weight ratio of 7-9:1 and mixed and ball-milled for 0.5-1 hour to obtain a composite; in step S5, the coupling agent is a mixed solution obtained by uniformly dispersing a triaminosilane coupling agent and succinic acid mono-2-(2-acryloyloxy)hydroxyethanol in a weight ratio of 1:0.5-1.5; in step S7, the modified amine curing agent is a mixture obtained by uniformly dispersing a modified alicyclic amine curing agent and a modified polyetheramine curing agent in a weight ratio of 3-4:1; the ratio of the defoaming agent in step S2 to the defoaming agent in step S5 is 2-3:3.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. The present invention improves the paint film hardness of the waterborne epoxy zinc-rich primer by adding a composite resin of styrene-maleic anhydride resin and bisphenol A liquid epoxy resin. The introduction of the composite resin allows it to cross-link with the modified amine curing agent, increasing additional cross-linking points, reducing the exposure of the active groups of the composite resin and the modified amine curing agent, and enhancing the water resistance of the paint film. The high reactivity of the styrene-maleic anhydride resin in the composite resin can chemically react with the epoxy groups in the bisphenol A liquid epoxy resin to form chemical bonds or interact with the pigment surface. The styrene-maleic anhydride resin not only improves the cross-linking density of the coating by participating in the curing process of bisphenol A liquid epoxy resin, but also forms a dense three-dimensional network structure with a high cross-linking density, which can effectively block the penetration of chemical media. At the same time, this dense three-dimensional network structure can better fix the zinc particles, promote the uniform dispersion of zinc powder in the coating, improve the compatibility of the resin and the curing agent, and enhance the corrosion resistance of the coating.

[0015] 2. The present invention uses a compound of succinic acid mono-2-(2-acryloyloxy)hydroxyethanol and triaminosilane coupling agent as a coupling agent, forms a stronger chemical bond at the organic-inorganic interface, promotes the uniform mixing of the components, gives full play to its dispersing effect, improves the gloss and color uniformity of the coating, enhances the corrosion resistance and water resistance of the coating, and prolongs the application period; in addition, the compounded coupling agent can react with the inorganic material and the organic polymer to form a chemical bond and a cross-linked structure respectively. Due to the different molecular sizes of the compound, a network structure is formed between the resin and the substrate, which effectively reduces the surface tension of the resin. force, significantly improving the wettability of the resin to the metal substrate and zinc powder, enhancing the bonding force between the coating and the substrate, and significantly improving the adhesion between the coating and the substrate; the compound coupling agent can also form a dense adsorption layer on the surface of the pigment and zinc powder through synergistic action, and effectively prevent the pigment from agglomerating and the zinc powder from depositing through steric effect and electrostatic repulsion, thereby ensuring the uniformity and stability of the coating system; at the same time, the compound coupling agent balances the cross-linking density and the flexibility of the cross-linking network, effectively alleviating the coating rigidity problem caused by excessive cross-linking of the amino group of the silane coupling agent, giving the coating good flexibility and significantly improving the impact resistance of the coating.

[0016] 3. The present invention utilizes a combination of titanium ditelluride and nanomaterials, utilizing the property of nanomaterials filling the spaces within titanium ditelluride to form an interlaced stacked structure. This improves micropores and defects in the coating, enhances the coating's density, and improves the coating's hardness and corrosion resistance. The conductivity of titanium ditelluride and the passivation effect of the nanomaterials synergistically distribute the corrosion products of zinc powder, forming a dense and stable protective film and enhancing the film's water resistance. Furthermore, the combination of titanium ditelluride and nanomaterials synergistically interacts with 2-(2-acryloyloxy)hydroxyethanol succinate to significantly improve the dispersibility of zinc powder in the coating, enhance the stability of the coating's performance, and extend the coating's corrosion life. If the antifouling topcoat or tiecoat layer on top of the primer is damaged by external forces, the titanium ditelluride in the primer and 2-(2-acryloyloxy)hydroxyethanol succinate synergistically impart antifouling properties to the paint film, preventing rapid corrosion caused by microbial attachment and proliferation in the primer exposed at the damaged site. DETAILED DESCRIPTION

[0017] The present invention provides a waterborne epoxy zinc-rich primer, comprising a component A and a component B, wherein the weight ratio of the component A to the component B is 15-20:1. Calculated by weight, the component A comprises 10-15 parts of a resin, 0.5-1 part of a coupling agent, 0.5-1 part of a defoamer, 0.1-1 part of a wetting agent, 0.1-1 part of a thickener, 1-2 parts of a pigment, 65-85 parts of zinc powder, and 8-10 parts of a first aqueous solvent. The component B comprises, calculated by weight, 30-60 parts of a modified amine curing agent, 10-20 parts of a second aqueous solvent, 20-30 parts of deionized water, and 3-5 parts of a flash rust preventer. The resin is a compound of a bisphenol A liquid epoxy resin and a styrene-maleic anhydride resin, and the epoxy equivalent of the bisphenol A liquid epoxy resin is 185-215 g / eq. The modified amine curing agent is a compound of a modified alicyclic amine curing agent and a modified polyetheramine curing agent.

[0018] In the composite resin of bisphenol A liquid epoxy resin and styrene-maleic anhydride resin, the epoxy groups of the bisphenol A liquid epoxy resin molecules undergo a ring-opening polymerization reaction under the action of a curing agent, forming a three-dimensional network polymer structure to wrap the zinc powder. In the present invention, a modified amine curing agent composite system of a modified alicyclic amine curing agent and a modified polyetheramine curing agent is used to achieve emulsification of the composite resin, promote phase inversion of the system, and thus prepare a water-based epoxy zinc-rich primer. During the coating film-forming process, the active hydrogen of the modified amine curing agent undergoes a cross-linking reaction with the epoxy groups of the bisphenol A liquid epoxy resin. The epoxy groups are ring-opened to generate hydroxyl groups. Since the hydroxyl groups are in a naked state, they are easy to absorb water, thereby reducing the water resistance of the paint film and causing blistering of the coating. The introduction of styrene-maleic anhydride resin forms additional cross-linking points. Research has found that the formation of these additional cross-linking points can not only enhance the overall chemical bonding strength of the coating and reduce the exposure of active groups, thereby enhancing the hardness and water resistance of the paint film, but also improve the degree of interweaving of molecular chains within the system, constructing a denser and more three-dimensional network structure, providing more space for zinc powder to accommodate sites, effectively inhibiting the agglomeration of zinc powder particles, and achieving uniform dispersion of zinc powder in the coating. At the same time, this highly interwoven three-dimensional network structure helps to enhance the physical entanglement and chemical bonding between the resin and curing agent molecules, reduce the phase separation trend between the two, thereby improving the compatibility of the resin and curing agent and enhancing the corrosion resistance of the coating.

[0019] A lower epoxy equivalent will result in a higher cross-linking density of the coating and better salt spray resistance, but the coating will be more brittle and have poor impact resistance and adhesion; a higher epoxy equivalent will reduce the hardness of the paint film. Although the adhesion is improved, the water resistance will deteriorate. In order to ensure that the coating has good hardness, impact resistance, water resistance and salt spray resistance after curing, the epoxy equivalent of the bisphenol A liquid epoxy resin is preferably between 185 and 215 g / eq.

[0020] Research has found that although both bisphenol A liquid epoxy resin and styrene-maleic anhydride resin can participate in the curing reaction, the amount of the two after compounding affects the hardness, corrosion resistance, impact resistance and other properties of the coating. As the weight ratio of bisphenol A liquid epoxy resin to styrene-maleic anhydride resin increases, the hardness of the paint film tends to increase, but the corrosion resistance and impact resistance of the paint film decrease. Preferably, the weight ratio of bisphenol A liquid epoxy resin to styrene-maleic anhydride resin is 8:1 to 2. The bisphenol A liquid epoxy resin is selected from at least one of EPIKOTE 3510-W-60A, Epikote WD-510A or Epikote WD-512A, and the styrene-maleic anhydride resin is selected from at least one of SMA 2025, Polyscope XIRAN 6000 or Polyscope XIRAN 9000.

[0021] The modified amine curing agent of the present invention adopts modified alicyclic amine curing agent and modified polyetheramine curing agent composite system, wherein, modified alicyclic amine curing agent gives paint film excellent hardness due to the formation of higher cross-linking density, and modified polyetheramine curing agent provides good flexibility for paint film through the flexible segment in its molecular structure. The two composites can effectively balance the hardness and flexibility of the paint film, and for the paint film, both can resist external friction and collision, and can keep good ultraviolet resistance, gloss, strength, impact resistance and other physical properties in different environments. The present invention has found through research that modified alicyclic amine curing agent and modified polyetheramine curing agent composite are added to the paint film, except for the above-mentioned advantages, modified alicyclic amine curing agent curing speed is relatively slow, and modified polyetheramine curing agent curing speed is fast, and the speed of curing reaction can be adjusted by regulating and controlling the two ratios, so that coating has a relatively long pot life in construction process, is convenient for operating personnel to carry out construction operation, reduces waste and construction inconvenience caused by excessively fast curing of coating. The weight ratio of the modified alicyclic amine curing agent to the modified polyetheramine curing agent is 3 to 4:1, the modified alicyclic amine curing agent is selected from at least one of MH-6618 and ZY-S078, and the modified polyetheramine curing agent is selected from at least one of R-2257K, R-2257D, and JEFFAMINE D-2010.

[0022] In existing technologies, triaminosilane coupling agents can directly react with the active groups in bisphenol A liquid epoxy resins to promote the construction of a crosslinked network. However, due to the high reactivity of triaminosilane coupling agents, they accelerate the crosslinking of the resin and curing agent, thereby reducing the pot life of the coating and even causing the network structure to become rigid, significantly increasing the rigidity of the paint film and decreasing its toughness. Furthermore, excessively fast crosslinking can inhibit the resin from fully wetting the zinc powder and substrate surface, leaving microscopic gaps at the interface and exposing unreacted hydrophilic groups, thereby reducing the coating's acid and alkali resistance and water resistance. The present invention has been found to introduce succinic acid mono-2-(2-acryloyloxy) hydroxyethanol and triaminosilane coupling agent compounding as coupling agent use, the compounded coupling agent and the hydroxyl group on the pigment surface undergo condensation reaction to form a chemical bond, the organic functional group on the coupling agent reacts chemically with the molecules in the organic polymer to form a cross-linked structure, closing the distance between the inorganic and organic matter, thereby extending the induction period of the curing reaction, extending the work life of the coating, and by forming a stronger chemical bond at the organic-inorganic interface, promoting the mixing between the pigment and the polymer, giving full play to its dispersing effect, improving the gloss and color uniformity of the coating, and enhancing the acid and alkali resistance and water resistance of the coating. In addition, the compounded coupling agent can construct a chemical bond network between the resin and the substrate, effectively reducing the surface tension of the resin, significantly improving the wettability of the resin to the substrate and zinc powder, enhancing the physical adsorption and chemical bonding between the coating and the substrate, thereby significantly improving the coating adhesion, and still maintaining a high adhesion in a hot and humid environment. The acryloyl chloride groups in the compounded coupling agent, 2-(2-acryloyloxy)hydroxyethanol succinate, react with the amino groups in the triaminosilane coupling agent to form a cross-linked network. This cross-linked network can evenly cover the surface of the pigment and zinc powder, forming an adsorption layer. Utilizing steric hindrance and electrostatic repulsion, it effectively prevents pigment agglomeration and zinc powder deposition, ensuring the uniformity and stability of the coating system. Furthermore, the triaminosilane coupling agent has a small molecule, high reactivity, and fast curing speed, resulting in a high film hardness. The compounded 2-(2-acryloyloxy)hydroxyethanol succinate has a large molecule and a slow curing speed. The two balance cross-linking density and network flexibility, effectively alleviating the coating rigidity problem caused by excessive cross-linking of the amino groups in the silane coupling agent, imparting good flexibility to the coating and significantly improving its impact resistance.

[0023] In the present invention, a higher weight ratio of triaminosilane coupling agent to succinic acid mono-2-(2-acryloyloxy) hydroxyethanol reduces the flexibility of the coating and shortens the pot life of the coating; conversely, a lower weight ratio of triaminosilane coupling agent to succinic acid mono-2-(2-acryloyloxy) hydroxyethanol reduces the hardness of the coating and slows the curing speed of the coating, thereby reducing construction efficiency. Preferably, the weight ratio of the triaminosilane coupling agent to succinic acid mono-2-(2-acryloyloxy) hydroxyethanol is 1:0.5-1.5, and the triaminosilane coupling agent is selected from at least one of Dynasylan® TRIAMO and QX-618.

[0024] The present invention has found that after titanium ditelluride is compounded with nanomaterials, the nanomaterials fill the spatial gaps of titanium ditelluride with a two-dimensional layered structure and high specific surface area, forming an interlaced stacking structure. This improves the micropores and defects in the coating, enhances the density of the coating, and helps to prevent external corrosive media from eroding the interior of the coating and the protected substrate, thereby improving the hardness and corrosion resistance of the coating and extending the service life of the protected object. The compounding of titanium ditelluride and nanomaterials forms a synergistic filling effect, which can accurately embed the tiny gaps between zinc powder particles, reducing the area of zinc powder exposed to the corrosive environment and reducing the consumption rate of zinc powder. At the same time, mono-2-(2-acryloyloxy)hydroxyethanol succinate reacts chemically with the hydroxyl groups and organic polymer molecules on the surface of the nanomaterial to form a cross-linked structure, allowing the zinc powder particles to be embedded therein, significantly improving the dispersibility of zinc powder in the coating, improving the stability of the coating performance, and extending the anti-corrosion life of the coating. The conductivity of titanium ditelluride and the passivation effect of nanomaterials work together to evenly distribute the corrosion products of zinc powder, forming a dense and stable protective film and enhancing the water resistance of the paint film. When the antifouling topcoat and tie paint are damaged by external factors, the titanium ditelluride in the primer generates Te 4+ ,Te 4+ Together with the carboxylate ions generated by the dissociation of succinic acid mono-2-(2-acryloyloxy)hydroxyethanol, they form a charge environment that is not conducive to the attachment of microorganisms, and by improving the hydrophobicity of the paint film, effectively inhibit the attachment of microorganisms. In addition, by interacting with the enzymes in the microorganisms, the growth and reproduction of microorganisms are hindered, thereby giving the paint film anti-fouling properties and avoiding the rapid corrosion caused by the attachment and reproduction of microorganisms on the primer exposed at the damaged part. The higher the weight ratio of nanomaterials to titanium ditelluride, the more difficult it is to disperse the filler, and thus the hardness and corrosion resistance of the paint film become unstable; the lower the weight ratio of nanomaterials to titanium ditelluride, the lower the hardness and corrosion resistance of the paint film. Preferably, the weight ratio of nanomaterials to titanium ditelluride is 7 to 9:1, and the nanomaterial is selected from at least one of nanographene, carbon nanotubes, nanosilicon dioxide, and nanocalcium carbonate.

[0025] The defoaming agent used in the present invention is an organosilicon defoaming agent. The organosilicon defoaming agent effectively exerts a defoaming effect in the waterborne epoxy zinc-rich primer by reducing surface tension, destroying foam structure, and inhibiting foam regeneration, while improving the construction performance of the coating. The organosilicon defoaming agent is selected from at least one of Dow Corning® AFE-1510 and TEGO® Foamex 810.

[0026] The wetting agent used in the present invention is an organosilicon twin structure surfactant. The organosilicon twin structure surfactant has a lower surface tension, which makes it easier for the coating to wet the substrate and can be more evenly coated on the substrate surface. At the same time, it works synergistically with the defoamer to reduce the shrinkage holes and bubble problems of the coating. The organosilicon twin structure surfactant is selected from at least one of TEGO Twin 4100, TEGO Twin 4000, and BSM-14100.

[0027] The thickener used in the present invention is selected from at least one of RHEOVIS® PE 1331, RHEOLATE® 350, TEGO® ViscoPlus 3030, or HOSTACERIN® WO 30; the pigment is selected from at least one of mica iron oxide, zinc phosphate, zinc molybdate, calcium molybdate, red iron oxide, and yellow iron oxide; the first aqueous solvent and the second aqueous solvent are respectively selected from at least one of isopropyl alcohol, ethylene glycol butyl ether, and propylene glycol methyl ether; and the flash rust inhibitor is selected from at least one of ANTICO ARCH100S, NALZIN® FA180, and Coadd™ FR-6018.

[0028] The present invention also provides a method for preparing a waterborne epoxy zinc-rich primer, comprising the following steps: S1: Add the first aqueous solvent and the resin into a dispersion kettle in sequence and disperse for 15 to 30 minutes; S2: Add the defoamer into the dispersion kettle and disperse for 5 to 10 minutes; S3: Add the pigment, titanium ditelluride and nanomaterial mixture under stirring and disperse for 15 to 30 minutes; S4: Add zinc powder while stirring and disperse for 30-50 minutes; S5: Add defoamer, wetting agent, and coupling agent and disperse for 20-30 minutes; S6: Using a thickener and the first aqueous solvent, adjust the viscosity to 90-100 KU, and filter through a 150-mesh filter to obtain component A; S7: Add the modified amine curing agent, the second aqueous solvent, deionized water, and the flash rust preventer into a dispersion kettle in sequence, and disperse for 15 to 30 minutes to obtain component B; S8: Evenly mix component A and component B to obtain a waterborne epoxy zinc-rich primer; In step S1, bisphenol A liquid epoxy resin and styrene-maleic anhydride resin are sequentially added to a dispersion kettle in a weight ratio of 8:1-2 for dispersion; in step S3, nanomaterials and titanium ditelluride are placed in a drum ball mill in a weight ratio of 7-9:1 and mixed and ball-milled for 0.5-1 hour to obtain a composite; in step S5, triaminosilane coupling agent and succinic acid mono-2-(2-acryloyloxy)hydroxyethanol are uniformly dispersed in a weight ratio of 1:0.5-1.5 to obtain a mixed solution; in step S7, the modified amine curing agent is a mixture of a modified alicyclic amine curing agent and a modified polyetheramine curing agent uniformly dispersed in a weight ratio of 3-4:1; the ratio of the defoaming agent in step S2 to the defoaming agent in step S5 is 2-3:3. Example 1

[0029] A waterborne epoxy zinc-rich primer has a weight ratio of component A to component B of 15:1. Component A comprises, calculated in parts by weight, 10 parts of a resin, 0.6 parts of a coupling agent, 0.5 parts of a defoaming agent, 0.1 parts of a wetting agent, 0.1 parts of a thickener, 1 part of a pigment, 65 parts of zinc powder, 8 parts of a first aqueous solvent, and 1.2 parts of a compound. Component B comprises, calculated in parts by weight, 30 parts of a modified amine curing agent, 10 parts of a second aqueous solvent, 20 parts of deionized water, 3 parts of an anti-flash rust agent, 1 part of a nanomaterial, and 0.2 parts of titanium ditelluride.

[0030] This embodiment provides a method for preparing a water-based epoxy zinc-rich primer, comprising the following steps: S1: 7 parts of isopropyl alcohol (first aqueous solvent), 8.9 parts of EPIKOTE 3510-W-60A (bisphenol A liquid epoxy resin), and 1.1 parts of SMA 2025 (styrene-maleic anhydride resin) were added to a dispersion kettle in sequence and dispersed for 15 minutes; S2: Add 0.2 parts of Dow Corning® AFE-1510 (silicone defoamer) into the dispersion kettle and disperse for 5 minutes; S3: Under stirring, add 1 part of mica iron oxide (pigment), a compound obtained by pre-mixing 1 part of nanographene (nanomaterial) and 0.2 parts of titanium ditelluride in a drum ball mill, and disperse for 15 minutes; S4: Add 65 parts of zinc powder while stirring and disperse for 30 minutes; S5: Add 0.3 parts of Dow Corning® AFE-1510 (silicone defoamer), 0.1 parts of TEGO Twin 4100 (silicone twin structure surfactant), and a coupling agent prepared by pre-dispersing 0.3 parts of Dynasylan® TRIAMO (triaminosilane coupling agent) and 0.3 parts of succinic acid mono-2-(2-acryloyloxy)hydroxyethanol, and disperse for 20 minutes. S6: Add 0.1 part RHEOVIS® PE 1331 (thickener) and 1 part isopropyl alcohol (first aqueous solvent) to a viscosity of 90-100 KU. Filter through a 150-mesh filter to obtain component A. S7: 24 parts of MH-6618 (modified alicyclic amine curing agent) and 6 parts of R-2257K (modified polyetheramine curing agent) pre-dispersed to obtain a modified amine curing agent, 10 parts of isopropyl alcohol (second aqueous solvent), 20 parts of deionized water, and 3 parts of ANTICOARCH100S (flash rust inhibitor) were added to a dispersion kettle in sequence and dispersed for 15 minutes to obtain component B; S8: Mixing the component A and the component B in a mass ratio of 15:1 to obtain the waterborne epoxy zinc-rich primer. Example 2

[0031] A waterborne epoxy zinc-rich primer, comprising component A and component B in a weight ratio of 18:1. Component A comprises, calculated in parts by weight, 12 parts of a resin, 0.5 parts of a coupling agent, 0.6 parts of a defoaming agent, 0.2 parts of a wetting agent, 1 part of a thickener, 1 part of a pigment, 83 parts of zinc powder, 9 parts of a first aqueous solvent, and 3 parts of a compound; and component B comprises, calculated in parts by weight, 40 parts of a modified amine curing agent, 15 parts of a second aqueous solvent, 25 parts of deionized water, and 4 parts of an anti-flash rust agent.

[0032] This embodiment provides a method for preparing a water-based epoxy zinc-rich primer, comprising the following steps: S1: 8 parts of ethylene glycol butyl ether (first aqueous solvent), 10 parts of Epikote WD-510A (bisphenol A liquid epoxy resin), and 2 parts of Polyscope XIRAN 6000 (styrene-maleic anhydride resin) were added to a dispersion kettle in sequence and dispersed for 30 minutes; S2: Add 0.3 parts of TEGO® Foamex 810 (silicone defoamer) into the dispersion kettle and disperse for 10 minutes; S3: Under stirring, add 1 part of red iron oxide (pigment), 2.7 parts of nano-silicon dioxide (nanomaterial) and 0.3 parts of titanium ditelluride pre-mixed in a drum ball mill, and disperse for 30 minutes; S4: Add 83 parts of zinc powder while stirring and disperse for 50 minutes; S5: Add 0.3 parts of TEGO® Foamex 810 (silicone defoamer), 0.2 parts of BSM-14100 (silicone gemini surfactant), and a coupling agent pre-dispersed with 0.2 parts of QX-618 (triaminosilane coupling agent) and 0.3 parts of succinic acid mono-2-(2-acryloyloxy)hydroxyethanol, and disperse for 30 minutes. S6: Add 1 part RHEOLATE® 350 (thickener) and 1 part ethylene glycol butyl ether (first aqueous solvent) to a viscosity of 90-100 KU and filter through a 150-mesh filter to obtain component A. S7: Add 31 parts of ZY-S078 (modified alicyclic amine curing agent) and 9 parts of R-2257D (modified polyetheramine curing agent) pre-dispersed curing agent, 15 parts of propylene glycol methyl ether (second aqueous solvent), 25 parts of deionized water, and 4 parts of NALZIN® FA180 (flash rust inhibitor) into a dispersion kettle in sequence and disperse for 30 minutes to obtain component B. S8: Mixing the component A and the component B in a mass ratio of 18:1 to obtain the waterborne epoxy zinc-rich primer. Example 3

[0033] A waterborne epoxy zinc-rich primer, wherein the weight ratio of component A to component B is 20:1. Component A comprises, calculated in parts by weight, 15 parts of resin, 1 part of coupling agent, 1 part of defoamer, 1 part of wetting agent, 0.2 part of thickener, 2 parts of pigment, 85 parts of zinc powder, 10 parts of a first aqueous solvent, and 1 part of a compound; and component B comprises, calculated in parts by weight, 60 parts of a modified amine curing agent, 20 parts of a second aqueous solvent, 30 parts of deionized water, and 3 parts of an anti-flash rust agent.

[0034] This embodiment provides a method for preparing a water-based epoxy zinc-rich primer, comprising the following steps: S1: 8 parts of ethylene glycol butyl ether (first aqueous solvent), 12 parts of Epikote WD-512A (bisphenol A liquid epoxy resin), and 3 parts of Polyscope XIRAN 9000 (styrene-maleic anhydride resin) were added to a dispersion kettle in sequence and dispersed for 20 minutes; S2: Add 0.45 parts of Dow Corning® AFE-1510 (silicone defoamer) into the dispersion kettle and disperse for 8 minutes; S3: Under stirring, add 1 part of mica iron oxide (pigment), 1 part of zinc phosphate (pigment), 0.9 parts of nano calcium carbonate (nanomaterial) and 0.1 parts of titanium ditelluride pre-mixed in a drum ball mill, and disperse for 25 minutes; S4: Add 85 parts of zinc powder while stirring and disperse for 40 minutes; S5: Add 0.55 parts of TEGO® Foamex 810 (silicone defoamer), 0.5 parts of TEGO Twin 4000 (silicone twin structure surfactant), 0.5 parts of BSM-14100 (silicone twin structure surfactant), 0.3 parts of Dynasylan® TRIAMO (triaminosilane coupling agent), 0.4 parts of QX-618 (triaminosilane coupling agent), and 0.3 parts of succinic acid mono-2-(2-acryloyloxy)hydroxyethanol, and disperse for 25 minutes; S6: Add 0.1 parts of TEGO® ViscoPlus 3030 (thickener), 0.1 parts of HOSTACERIN® WO 30 (thickener), and 2 parts of propylene glycol methyl ether (first aqueous solvent), adjust the viscosity to 90-100 KU, and filter through a 150-mesh filter to obtain component A. S7: Add 20 parts of MH-6618 (modified alicyclic amine curing agent), 25 parts of ZY-S078 (modified alicyclic amine curing agent), 10 parts of R-2257K (modified polyetheramine curing agent), 5 parts of JEFFAMINE D-2010 (modified polyetheramine curing agent) pre-dispersed curing agent, 20 parts of ethylene glycol butyl ether (second aqueous solvent), 30 parts of deionized water, 2 parts of NALZIN® FA 180 (flash rust inhibitor), and 3 parts of Coadd™ FR-6018 (flash rust inhibitor) into a dispersion kettle in sequence and disperse for 20 minutes to obtain component B; S8: mixing the component A and the component B in a mass ratio of 20:1 to obtain the waterborne epoxy zinc-rich primer; Comparative Example 1 The preparation method of this comparative example is the same as that of Example 2. The only difference from Example 2 is that this comparative example does not use the styrene-maleic anhydride resin Polyscope XIRAN 6000, but uses an equal amount of bisphenol A liquid epoxy resin Epikote WD-510A instead.

[0035] Comparative Example 2 The preparation method of this comparative example is the same as that of Example 2. The only difference from Example 2 is that this comparative example does not use succinic acid mono-2-(2-acryloyloxy)hydroxyethanol, but uses an equal amount of triaminosilane coupling agent QX-618 instead.

[0036] Comparative Example 3 The preparation method of this comparative example is the same as that of Example 2. The only difference from Example 2 is that this comparative example does not use titanium ditelluride, but uses an equal amount of nano-silicon dioxide instead.

[0037] Comparative Example 4 The preparation method of this comparative example is the same as that of Example 2. The only difference from Example 2 is that this comparative example does not use the modified polyetheramine curing agent R-2257D, but replaces it with an equal amount of modified alicyclic amine curing agent ZY-S078.

[0038] Comparative Example 5 The preparation method of this comparative example is the same as that of Example 2. The only difference from Example 2 is that the resin in this comparative example is 12 parts of bisphenol A liquid epoxy resin CYD-134 with an epoxy equivalent weight of 230-270 g / eq; the coupling agent is triaminosilane coupling agent QX-618; titanium ditelluride is replaced by an equal amount of nano-silica; and the modified amine curing agent is modified alicyclic amine curing agent MH-6618.

[0039] The performance test of the waterborne epoxy zinc-rich primer prepared in Examples 1 to 3 and Comparative Examples 1 to 5 was carried out (product implementation standard: HG / T 3668-2020 zinc-rich primer). The test results are shown in Table 1 below: Table 1 Performance test results of waterborne epoxy zinc-rich primer

[0040] The test results in Table 1 show that, compared with Comparative Example 1, Example 2 shows that compounding bisphenol A liquid epoxy resin with an epoxy equivalent of 185 to 215 g / eq with styrene-maleic anhydride resin can improve the hardness of the paint film, enhance the adhesion between the coating and the substrate, and significantly improve the water resistance, salt spray resistance, acid resistance, and alkali resistance of the coating.

[0041] Comparing Example 2 with Comparative Example 2, the results show that after the specific ratio of triaminosilane coupling agent is compounded with mono-2-(2-acryloyloxy)hydroxyethanol succinate, the adhesion between the coating and the substrate is improved, the corrosion resistance and water resistance of the coating are enhanced, the applicability period of the coating is extended, and at the same time, good flexibility is given to the coating, which significantly improves the impact resistance of the coating.

[0042] Comparing Example 2 with Comparative Example 3, the results show that the use of titanium ditelluride and nanomaterials in a specific ratio in the water-based epoxy zinc-rich primer provided by the present invention can improve the hardness, corrosion resistance and water resistance of the coating, extend the anti-corrosion life of the coating, and give the coating good anti-fouling properties.

[0043] Comparing Example 2 with Comparative Examples 2 and 3, the results show that under the action of oxidation, titanium ditelluride and mono-2-(2-acryloyloxy)hydroxyethanol succinate can synergistically impart antifouling properties to the paint film.

[0044] Comparing Example 2 with Comparative Example 4, the results show that after the modified alicyclic amine curing agent and the modified polyetheramine curing agent are compounded in a specific ratio, their advantages complement each other, effectively balance the hardness and flexibility of the paint film, and extend the application life of the coating.

[0045] Comparing Example 2 with Comparative Example 5, the results show that the water-based epoxy zinc-rich primer prepared by compounding bisphenol A liquid epoxy resin with an epoxy equivalent of 185 to 215 g / eq with styrene-maleic anhydride resin, triaminosilane coupling agent and succinic acid mono-2-(2-acryloyloxy)hydroxyethanol, titanium ditelluride and nanomaterials, modified alicyclic amine curing agent and modified polyetheramine curing agent in a specific ratio has a long pot life, good zinc powder dispersion stability, good coating flexibility, high impact resistance, excellent water resistance and corrosion resistance, the coating hardness and flexibility meet the standards, the coating has certain anti-fouling properties, strong adhesion in high humidity and high heat environments, and is suitable for the shipbuilding field.

[0046] The foregoing description is intended only to provide specific embodiments of the present disclosure, intended to enable those skilled in the art to understand and implement the present disclosure. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present disclosure. Therefore, the present disclosure is not intended to be limited to the embodiments described herein, but rather to be construed in the broadest manner consistent with the principles and novel features disclosed herein.

Claims

1. A waterborne epoxy zinc-rich primer, characterized in that, The invention comprises component A and component B, wherein the weight ratio of component A to component B is 15-20:

1. Calculated by weight, component A comprises 10-15 parts of resin, 0.5-1 part of coupling agent, 0.5-1 part of defoaming agent, 0.1-1 part of wetting agent, 0.1-1 part of thickener, 1-2 parts of pigment, 65-85 parts of zinc powder, and 8-10 parts of a first aqueous solvent. Calculated by weight, the B component includes 30-60 parts of a modified amine curing agent, 10-20 parts of a second aqueous solvent, 20-30 parts of deionized water, and 3-5 parts of an anti-flash rust agent; The resin is a compound of bisphenol A liquid epoxy resin and styrene-maleic anhydride resin, and the epoxy equivalent of the bisphenol A liquid epoxy resin is 185-215 g / eq; The modified amine curing agent is a compound of a modified alicyclic amine curing agent and a modified polyether amine curing agent.

2. A waterborne epoxy zinc-rich primer according to claim 1, characterized in that, The weight ratio of the bisphenol A liquid epoxy resin to the styrene-maleic anhydride resin is 8:1-2; the bisphenol A liquid epoxy resin is selected from at least one of EPIKOTE 3510-W-60A, Epikote WD-510A, and Epikote WD-512A; and the styrene-maleic anhydride resin is selected from at least one of SMA 2025, Polyscope XIRAN 6000, and Polyscope XIRAN 9000.

3. A waterborne epoxy zinc-rich primer according to claim 1, characterized in that, The coupling agent is a compound of triaminosilane coupling agent and succinic acid mono-2-(2-acryloyloxy)hydroxyethanol, the weight ratio of the triaminosilane coupling agent to succinic acid mono-2-(2-acryloyloxy)hydroxyethanol is 1:0.5~1.5, and the triaminosilane coupling agent is selected from at least one of Dynasylan® TRIAMO and QX-618.

4. A waterborne epoxy zinc-rich primer according to claim 1, characterized in that, The weight ratio of the modified alicyclic amine curing agent to the modified polyetheramine curing agent is 3 to 4:1, the modified alicyclic amine curing agent is selected from at least one of MH-6618 and ZY-S078, and the modified polyetheramine curing agent is selected from at least one of R-2257K, R-2257D, and JEFFAMINE D-2010.

5. A waterborne epoxy zinc-rich primer according to claim 1, characterized in that, The defoaming agent is a silicone defoaming agent, and the silicone defoaming agent is selected from at least one of Dow Corning® AFE-1510 and TEGO® Foamex 810.

6. A waterborne epoxy zinc-rich primer according to claim 1, characterized in that, The wetting agent is an organosilicon twin structure surfactant, and the organosilicon twin structure surfactant is selected from at least one of TEGO Twin 4100, TEGO Twin 4000, and BSM-14100.

7. A waterborne epoxy zinc-rich primer according to claim 1, characterized in that, The thickener is selected from at least one of RHEOVIS® PE 1331, RHEOLATE® 350, TEGO® ViscoPlus 3030, and HOSTACERIN® WO 30; the flash rust inhibitor is selected from at least one of ANTICO ARCH100S, NALZIN® FA 180, and Coadd™ FR-6018; the pigment is selected from at least one of mica iron oxide, zinc phosphate, zinc molybdate, calcium molybdate, red iron oxide, and yellow iron oxide; and the first aqueous solvent and the second aqueous solvent are respectively selected from at least one of isopropyl alcohol, ethylene glycol butyl ether, and propylene glycol methyl ether.

8. A waterborne epoxy zinc-rich primer according to claim 1, characterized in that, The component A further comprises 1 to 3 parts of a compound of titanium ditelluride and nanomaterials, wherein the weight ratio of the nanomaterial to titanium ditelluride in the compound is 7 to 9:1, and the nanomaterial is selected from at least one of nanographene, carbon nanotubes, nanosilicon dioxide, and nanocalcium carbonate.

9. A method for preparing a waterborne epoxy zinc-rich primer as claimed in any one of claims 1 to 8, characterized in that: The specific steps include: S1: First, add the first aqueous solvent and resin into the dispersion kettle in sequence and disperse for 15 to 30 minutes; S2: Add the defoamer into the dispersion kettle and disperse for 5 to 10 minutes; S3: Add pigment, titanium ditelluride and nanomaterial compound under stirring and disperse for 15 to 30 minutes; S4: Add zinc powder while stirring and disperse for 30-50 minutes; S5: Add defoamer, wetting agent, and coupling agent in sequence and disperse for 20-30 minutes; S6: Using the thickener and the first aqueous solvent, adjust the viscosity to 90-100 KU, and then filter through a 150-mesh filter to obtain component A; S7: Then, the modified amine curing agent, the second aqueous solvent, deionized water, and the flash rust preventer are sequentially added into a dispersion kettle and dispersed for 15 to 30 minutes to obtain component B; S8: Finally, component A and component B are mixed evenly to obtain a water-based epoxy zinc-rich primer.

10. The method for preparing a waterborne epoxy zinc-rich primer according to claim 9, wherein: In step S1, the resin is a bisphenol A liquid epoxy resin and a styrene-maleic anhydride resin in a weight ratio of 8:1-2, and the two are sequentially placed in a dispersion kettle for dispersion; in step S3, the nanomaterial and titanium ditelluride are placed in a ball mill at a weight ratio of 7-9:1 and mixed and ball-milled for 0.5-1 hour to obtain a composite; in step S5, the coupling agent is a mixed solution obtained by uniformly dispersing a triaminosilane coupling agent and succinic acid mono-2-(2-acryloyloxy)hydroxyethanol in a weight ratio of 1:0.5-1.5; in step S7, the modified amine curing agent is a mixture obtained by uniformly dispersing a modified alicyclic amine curing agent and a modified polyetheramine curing agent in a weight ratio of 3-4:1; the ratio of the defoaming agent in step S2 to the defoaming agent in step S5 is 2-3:3.

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