A rust-resistant coating, its preparation method and application

Abstract

This invention relates to a rust-resistant coating, its preparation method, and its application, belonging to the field of rust-resistant coating and anti-corrosion technology. The rust-resistant coating consists of agent A and agent B in a mass ratio of (4-6):1. Agent A includes the following components by mass: 5-12 parts rust conversion agent, 5-10 parts glass flakes, 10-15 parts modified zinc phosphate, 5-15 parts ultrafine high-hardness wear-resistant filler, 50-70 parts phenolic epoxy resin, and 2-6 parts additives. Agent B includes a polyamide curing agent. The rust conversion agent generates an insoluble, dense organic-metal complex protective film; the glass flakes improve the coating's impermeability and barrier effect; and the modified zinc phosphate and other composite anti-rust pigments continuously provide corrosion-inhibiting ions within the coating. The ultrafine high-hardness wear-resistant filler withstands mechanical friction and impact, and the intrinsically tough phenolic epoxy resin matrix absorbs some of the impact energy through deformation.

Description

Technical Field

[0001] This invention belongs to the field of anti-corrosion technology of rust-resistant coatings, specifically relating to a rust-resistant coating, its preparation method, and its application. Background Technology

[0002] The information disclosed in this background section is intended only to enhance understanding of the overall background of the invention and is not necessarily to be construed as an admission or in any way implying that such information constitutes prior art known to those skilled in the art.

[0003] In heavy-duty corrosion protection applications, such as marine engineering, chemical plants, logistics and warehousing floors, and mining machinery, coating systems face dual or even multiple forms of damage from chemical corrosion, mechanical wear, and impact. Traditional solutions often require multi-layer coating systems (such as primer-intermediate coat-topcoat) combined with stringent surface treatment (sandblasting to Sa2.5 grade), resulting in complex processes, high costs, and long construction periods. Existing single-layer or simplified coatings often have shortcomings in wear resistance or corrosion resistance, failing to meet long-term protection requirements. Meanwhile, the market increasingly demands aesthetic appeal and color recognition capabilities for coatings, but high performance and aesthetics are often mutually exclusive.

[0004] Existing rust-resistant coatings often fail to meet the requirements of friction or impact conditions in terms of abrasion resistance. If high cross-linking density resins and hard fillers are used to improve abrasion resistance, the coating will have high internal stress and be extremely sensitive to the cleanliness and roughness of the substrate. If rust or oil residue remains on the substrate surface, the coating cannot form effective chemical bonds and mechanical anchoring, and adhesion failure is very likely to occur at the interface. Therefore, it is necessary to sandblast to Sa2.5 or higher to provide sufficient surface roughness and cleanliness to prevent it from failing to adhere effectively to rust-resistant surfaces. On the other hand, due to the complex interfacial competitive adsorption between coloring pigments and rust conversion agents and rust-inhibiting pigments in the system, and the fact that conventional pigments cannot withstand the curing shrinkage stress of highly cross-linked systems, the addition of color often affects key performance. Summary of the Invention

[0005] Based on the current technical problems, the purpose of this invention is to provide a rust-resistant coating, its preparation method and application, which simplifies the heavy-duty anti-corrosion coating process by optimizing the component ratio, and improves the overall performance and service life of the coating.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows: In the first aspect, a rust-resistant coating is composed of agent A and agent B in a mass ratio of (4~6):1; agent A includes the following parts by mass: 5~12 parts of raw material rust conversion agent, 5~10 parts of glass flakes, 10~15 parts of modified zinc phosphate, 5~15 parts of ultrafine high-hardness wear-resistant filler, 50~70 parts of phenolic epoxy resin and 2~6 parts of additives; agent B includes polyamide curing agent.

[0007] Secondly, the preparation method of the aforementioned rust-resistant coating includes the following steps: A rust-converting agent, glass flakes, modified zinc phosphate, ultrafine high-hardness wear-resistant filler, phenolic epoxy resin, and additives are mixed to obtain Agent A; a polyamide curing agent is used as Agent B to obtain the rust-resistant coating.

[0008] Thirdly, the application of the above-mentioned rust-resistant coating includes the following steps: mixing agent A and agent B, applying the mixture to a rust-resistant steel substrate or concrete substrate, and drying it to form a film.

[0009] The beneficial effects of this invention are as follows: 1. The rust conversion agent in this invention can chelate with active iron ions in the rust layer to generate an insoluble, dense organic-metal complex protective film. This not only stabilizes the rust layer but also forms a strong chemical bond at the rust layer / coating interface, which is the basis for achieving "strong adhesion with rust." Glass flakes can be arranged in parallel in the coating, effectively extending the penetration path of corrosive media (water, oxygen, ions) and significantly improving the coating's impermeability and barrier effect. Modified zinc phosphate and other composite rust-inhibiting pigments can continuously provide corrosion-inhibiting ions in the coating, providing active electrochemical protection for exposed metal substrates or scratched areas. The above components together constitute a multi-layered protective structure from the coating interface to the substrate. The ultrafine, high-hardness, wear-resistant filler acts as a rigid skeleton, serving as a rigid support point to withstand mechanical friction and impact. At the same time, the selected high-crosslinking density and intrinsically tough phenolic epoxy resin matrix, combined with a high-toughness curing agent, absorbs some of the impact energy through deformation, preventing brittle cracking of the coating. The system utilizes ultrafine, high-hardness, wear-resistant fillers to form a rigid framework. Combined with a highly cross-linked, intrinsically tough phenolic epoxy resin matrix and a high-toughness curing agent, this synergistic mechanism of "rigid support + toughness absorption" effectively overcomes the poor wear resistance issues of traditional rust-resistant coatings caused by low resin cross-linking density and a high proportion of soft fillers. Simultaneously, the rust conversion agent forms a strong chemical bond at the rust / coating interface, imparting excellent adhesion to St2-grade low-surface-treatment substrates, thus reducing the demanding Sa2.5-grade sandblasting surface treatment typically required for high-wear-resistant coatings. Furthermore, the coloring pigments achieve compatibility matching with the rust conversion agent and rust-inhibiting pigments in the system through interfacial regulation of additives, avoiding interference with key anti-corrosion and adhesion performance caused by color additions in traditional formulations, achieving a balance between aesthetics and functionality. This multi-layer coating system, eliminating the need for primer-intermediate-topcoat layers, achieves ≥1500 hours of salt spray protection and an extremely low abrasion rate of ≤40mg with a single coating. Performance indicators meet or exceed those of traditional multi-layer systems, providing reliable assurance for long-term protection.

[0010] 2. This invention uses special additives to surface treat the wear-resistant filler and flake pigment, which greatly enhances their interfacial bonding with the resin matrix, prevents the filler from falling off during wear, and ensures the durability of wear resistance.

[0011] 3. This invention eliminates the need for sandblasting and high-standard rust removal. Only the loose rust products need to be removed according to St2 standards, retaining a firmly adhered, dense rust layer. The surface treatment process is economical and simple. After the firmly adhered rust layer is penetrated and chelated by a rust conversion agent, it is transformed into a stable organic-metal complex film, becoming an organic component of the coating system. Thanks to the system's excellent cohesiveness and rheological properties, a single coat can achieve a dry film thickness of 100-300 μm, forming a film in one application, resulting in high construction efficiency. This coating can be used in traditional anti-corrosion applications and is also suitable for protecting high-wear areas such as floors, chutes, and machinery housings, achieving multiple uses with a single material.

[0012] 4. This invention achieves color customization capabilities without sacrificing core performance, unifying aesthetics and functionality to meet the visual management requirements of modern chemical enterprises. Existing technologies often suffer from reduced adhesion, corrosion resistance, and wear resistance due to problems such as interfacial competitive adsorption, poor compatibility, interference with corrosion inhibition mechanisms, and increased internal stress when adding coloring pigments. This invention uses coupling agents and wetting and dispersing agents to regulate the interface of the coloring pigments, optimizing their compatibility with rust conversion agents and rust-inhibiting pigments; it utilizes the particle size distribution of glass flakes and ultrafine wear-resistant fillers to construct a dense packing structure, ensuring that the anti-corrosion and wear-resistant framework is not interfered with; and it selects chemically inert coloring pigments (such as titanium dioxide, phthalocyanine blue, and iron oxide red) and combines them with a high-toughness resin matrix, ensuring that color addition does not affect the core performance of the coating, thus achieving a unity of protective function and visual identification. Detailed Implementation

[0013] It should be noted that the following detailed descriptions are exemplary and intended to provide further illustration of the invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains.

[0014] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of exemplary embodiments according to the invention. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0015] One or more embodiments of the present invention provide a rust-resistant coating, which is composed of agent A and agent B in a mass ratio of (4~6):1. Agent A includes the following raw materials in parts by mass: 5~12 parts of rust conversion agent, 5~10 parts of glass flakes, 10~15 parts of modified zinc phosphate, 5~15 parts of ultrafine high-hardness wear-resistant filler, 50~70 parts of phenolic epoxy resin and 2~6 parts of additives; agent B includes polyamide curing agent.

[0016] Among the above components, the rust conversion agent is used to chelate with the active iron ions in the rust layer to form an organometallic complex protective film, so that the coating is stably bonded to the rust layer in a chemical bond manner; glass flakes have impermeability and barrier effect, extending the penetration path of corrosive media; modified zinc phosphate can release corrosion-inhibiting ions to provide electrochemical protection; ultrafine high-hardness wear-resistant filler and phenolic epoxy resin and high-toughness curing agent are used to improve the mechanical properties of the coating, while achieving a high level of smoke protection effect and extremely low wear rate.

[0017] Optionally, the rust conversion agent includes one or more of tannic acid and PBTCA; wherein, tannic acid is also known as tannic acid, CAS number 1401-55-4; and PBTCA is 2-phosphonobutane-1,2,4-tricarboxylic acid, CAS number 37971-36-1.

[0018] Optionally, the ultrafine high-hardness wear-resistant filler includes one or more of alumina and silicon carbide, with a Mohs hardness ≥7; the particle size of the ultrafine high-hardness wear-resistant filler is 750~850 mesh, approximately 15~20μm.

[0019] Optionally, the additives include one or more of coupling agents, wetting and dispersing agents, defoamers, and rheology modifiers; wherein, the coupling agent includes silane coupling agents, used to enhance the interfacial bonding between pigments / fillers and the resin matrix; the wetting and dispersing agents are used to reduce the interfacial tension between pigments and resins, promote the uniform dispersion of coloring pigments, anti-rust pigments, and fillers, prevent flocculation and sedimentation, and ensure uniform coating performance; the defoamers are used to suppress and eliminate bubbles generated during mixing and construction, avoid defects such as pinholes and shrinkage cavities in the coating, and ensure the density and shielding effect of the coating; the rheology modifiers include fumed silica, used to adjust the thixotropy and anti-sagging properties of the coating to meet the requirements of single-coat thick film construction (100~300μm), while preventing fillers from settling during storage.

[0020] Optionally, Agent A includes 0 to 20 parts of coloring pigment, including one or more of titanium dioxide, iron oxide red, and phthalocyanine green; the coloring pigment is surface modified by coupling agent and wetting and dispersing agent to achieve interfacial compatibility with rust conversion agent and rust-preventing pigment, ensuring that the addition of color does not affect the core anti-corrosion and wear-resistant properties of the coating.

[0021] Optionally, the polyamide curing agent has an amine value of 240-280. When a curing agent with this amine value range is combined with phenolic epoxy resin, it can form a moderate crosslinking density, which not only ensures the coating's excellent chemical resistance, corrosion resistance, and cohesive strength, but also gives the coating sufficient toughness to absorb impact energy and avoid brittle cracking. At the same time, this amine value range can achieve an application time of 0.5-2 hours, meeting the requirements of on-site coating processes.

[0022] Optionally, the glass flakes are 350-450 mesh, and the ultrafine high-hardness wear-resistant filler is 750-850 mesh; the two form a particle size distribution, with the glass flakes acting as a shielding skeleton to extend the penetration path of the corrosive medium, and the ultrafine filler filling the gaps between the flakes to form a rigid support, thus synergistically improving the impermeability and wear resistance of the coating.

[0023] One or more embodiments of the present invention provide a method for preparing the above-mentioned rust-resistant coating, comprising the steps of: A rust-converting agent, glass flakes, modified zinc phosphate, ultrafine high-hardness wear-resistant filler, phenolic epoxy resin, and additives are mixed to obtain Agent A; a polyamide curing agent is used as Agent B to obtain the rust-resistant coating.

[0024] Optionally, silane coupling agents are used to modify the surfaces of ultrafine high-hardness wear-resistant fillers and glass flakes respectively. The amount of silane coupling agent is 0.5% to 2.0% of the total mass of ultrafine high-hardness wear-resistant fillers and glass flakes. Dry or wet processing is used, and the modification is carried out by stirring in a high-speed mixing device at 80 to 100°C for 15 to 20 minutes to achieve uniform coating and activation of the filler surface. This enhances the interfacial bonding force between the filler and the resin matrix, prevents the filler from falling off during wear, and ensures the durability of wear resistance.

[0025] One or more embodiments of the present invention provide the application of the above-mentioned rust-resistant coating, including the steps of: mixing and stirring agent A and agent B, applying the mixture to a rust-resistant steel substrate or concrete substrate, and drying it to form a film.

[0026] After Agent A and Agent B are mixed in the set ratio, ensure that the triple protection reaction and the resin curing reaction proceed simultaneously and fully. During the process, the ratio can be finely adjusted within this range according to the ambient temperature and the construction area to obtain the optimal construction operation time of 0.5 to 2 hours.

[0027] Optionally, in the preparation and application method of the rust-resistant coating, the parallel arrangement of glass flakes in the coating is achieved by controlling the wetting and dispersion state of glass flakes in agent A and the application process, specifically as follows: Phenolic epoxy resin and additives (including wetting and dispersing agents, defoamers and rheology modifiers) are added to a container. Under high-speed stirring, ultrafine high-hardness wear-resistant filler, modified zinc phosphate, rust conversion agent and coloring pigment are added in sequence. The mixture is continuously dispersed until the fineness of the material is ≤30μm to ensure that the rigid filler and rust-preventive pigment are fully depolymerized and uniformly dispersed in the resin matrix. Add glass flakes while stirring at low speed and continue stirring for 10-15 minutes to ensure that the glass flakes are mixed evenly and not damaged, thus ensuring the integrity of their flake structure and obtaining Agent A. Airless spraying (nozzle pressure 15~20MPa) or scraping process is used to utilize the shear force generated when the coating flows on the substrate surface to cause the glass flakes to be oriented along the substrate direction; after coating, let it stand for 5~10 minutes to level, so that the flakes are further aligned in parallel inside the coating, thus forming an effective "maze-like" shielding layer.

[0028] Optionally, the mixture may be used within 12 months of the completion of the preparation of Agent A and Agent B respectively.

[0029] Optionally, the rust-resistant steel substrate is of grade St2; conforming to grade St2 in GB / T 8923.1, it is a rust removal effect that can be obtained by manual and power tools.

[0030] Optionally, the coating process uses a high-speed dispersion device to ensure that the abrasion-resistant filler is fully dispersed.

[0031] Optionally, when the construction environment is below 5°C, agent A should be preheated and a low-temperature curing variant of agent B should be selected.

[0032] Optionally, the film is cured under standard conditions for more than 7 days after formation; the standard conditions are temperature (23±2)℃ and relative humidity (50±5)%, which are performed in accordance with GB / T 9278 "Temperature and humidity for conditioning and testing of coating samples" to ensure that the coating is fully cross-linked and cured to achieve the best anti-corrosion and wear resistance performance.

[0033] The present invention will be further described below with reference to specific embodiments.

[0034] Example 1 A rust-resistant coating is composed of Agent A and Agent B in a mass ratio of 5:1. Agent A consists of the following raw materials in parts by mass: 8 parts tannic acid (rust conversion agent), 8 parts glass flakes, 12 parts modified zinc phosphate, 10 parts alumina micro powder (ultra-fine high-hardness wear-resistant filler), 60 parts F-51 (phenolic epoxy resin), 15 parts titanium dioxide (coloring pigment), and 5 parts additives. The additives include 1 part silane coupling agent KH-560, 1 part wetting and dispersing agent, 0.5 parts defoamer, and 1.5 parts fumed silica (rheology modifier).

[0035] Agent B is a polyamide curing agent with an amine value of 240. Specifically, you can choose ARADUR® 115 (or an equivalent product that meets the amine value requirements) from Huntsman Corporation.

[0036] The glass flakes are 400 mesh, and the ultrafine, high-hardness, wear-resistant filler is 800 mesh.

[0037] The modified zinc phosphate used in this embodiment is modified zinc phosphate (model: HJ-Z25) produced by Taihe Huijin Company. This product is a white microcrystalline powder with a particle size of 600 mesh, a P2O5 content of ≥40%, and an oil absorption of <35%. After being treated with additives, it has good wetting and dispersibility in epoxy resin, strong affinity with substrates and polymers, and can effectively improve the shielding performance and adhesion of the coating.

[0038] The method for preparing the rust-resistant coating in this embodiment uses a silane coupling agent to perform dry surface modification on ultrafine high-hardness wear-resistant fillers and glass flakes, respectively. The specific operations are as follows: The ultrafine high-hardness wear-resistant filler was put into a high-speed mixer. Silane coupling agent accounting for 0.6% of the mass of the ultrafine high-hardness wear-resistant filler was added under stirring. The speed was controlled at 900 rpm and the mixing temperature was 90℃. The mixture was stirred and modified for 18 minutes. After the material was discharged and cooled, the modified ultrafine high-hardness wear-resistant filler was obtained. Using the same method, glass flakes were used as the modification target. 0.6% of the glass flake mass of silane coupling agent was added, the rotation speed was controlled at 400 rpm (to avoid flake breakage), the mixing temperature was 70℃, and the modification was carried out by stirring for 13 minutes. After cooling, the modified glass flakes were obtained.

[0039] The preparation and application method of rust-resistant coatings includes the following steps: (1) Add phenolic epoxy resin to a dispersion vessel, start stirring, and control the speed at 400 rpm. Add the additives (including wetting and dispersing agent, defoamer, and rheology modifier) ​​in sequence and stir for 7 minutes until uniform. Increase the speed of the dispersion vessel to 900 rpm and add the modified ultrafine high-hardness wear-resistant filler, modified zinc phosphate, rust conversion agent, and coloring pigment in sequence while stirring at high speed. After the addition is completed, maintain the speed and continue high-speed dispersion for 25 minutes. Take a sample to test the fineness until the fineness of the material is ≤30μm. Reduce the speed of the dispersion vessel to 400 rpm and slowly add the modified glass flakes while stirring at low speed. After the addition is completed, maintain the low-speed stirring for 13 minutes to ensure that the glass flakes are uniformly mixed and not damaged. According to the viscosity, add an appropriate amount of rheology modifier to adjust to the working viscosity. Stir for 8 minutes until uniform, filter through an 80-mesh sieve, discharge and package to obtain Agent A.

[0040] (2) Use polyamide curing agent (polyamide adduct type epoxy curing agent) as agent B, with an amine value of 240, and package it according to specifications.

[0041] (3) Mix agent A and agent B at a mass ratio of 5:1, stir thoroughly for 4 minutes with an electric mixer until uniform, and let stand for 8 minutes before use.

[0042] During construction, airless spraying (nozzle pressure 18MPa) is used to coat the St2 grade stainless steel substrate. The coating is left to stand and level for 8 minutes, then dried to form a film. After film formation, it is cured for more than 7 days under standard conditions (temperature 23±2℃, relative humidity 50±5%). The film thickness is approximately 200μm.

[0043] The properties of the coating obtained in this embodiment include: Rust adhesion (pull-off test): approximately 8 MPa; Resistance to neutral salt spray: After 2000 hours, the erosion size on one side of the scratched sample is approximately 1.5 mm; Abrasion resistance (Taber CS-17, 1000 rpm / 1kg): abrasion loss 28mg; Impact resistance: 50cm, 1kg drop hammer impact, no cracking or detachment.

[0044] Example 2 A rust-resistant coating is composed of agent A and agent B in a mass ratio of 4:1. Agent A consists of the following raw materials in parts by mass: 5 parts PBTCA (rust conversion agent), 5 parts glass flakes, 10 parts modified zinc phosphate, 5 parts silicon carbide micro powder (ultrafine high-hardness wear-resistant filler), 50 parts F-51 (phenolic epoxy resin), 15 parts titanium dioxide (coloring pigment), 5 parts phthalocyanine blue, and 4 parts additives. The additives include 1 part wetting and dispersing agent, 0.5 parts defoamer, and 1.5 parts fumed silica (rheology modifier).

[0045] Agent B is a polyamide curing agent with an amine value of 240. Specifically, you can choose ARADUR® 115 (or an equivalent product that meets the amine value requirements) from Huntsman Corporation.

[0046] The glass flakes are 400 mesh, and the ultrafine, high-hardness, wear-resistant filler is 800 mesh.

[0047] The modified zinc phosphate used in this embodiment is ZPG-Y type modified zinc phosphate produced by Zhuzhou Jinqiao Zinc Industry Co., Ltd. This product is an ultrafine zinc phosphate that has undergone polymer surface grafting treatment, specifically designed for oil-based coating systems. By improving the activity, dispersibility, salt spray resistance, and adhesion of zinc phosphate, it achieves excellent rust prevention effects and is suitable for heavy-duty anti-corrosion coatings.

[0048] The preparation method differs from that in Example 1 in that: no silane coupling agent is used for modification; agent A is obtained by direct mixing, and agent B is obtained by mixing.

[0049] The properties of the coating include: Rust adhesion (pull-off test): approximately 5 MPa; Resistance to neutral salt spray: After 1000 hours, the erosion size on one side of the scratched sample is approximately 2.0 mm; Abrasion resistance (Taber CS-17, 1000 rpm / 1kg): abrasion loss 45 mg; Impact resistance: 50 cm·1 kg drop hammer impact, no cracking or peeling of the coating; Appearance: Uniform color, with no obvious color floating or discoloration.

[0050] Example 3 A rust-resistant coating is composed of agent A and agent B in a mass ratio of 6:1. Agent A includes the following raw materials in parts by mass: 12 parts tannic acid, 10 parts glass flakes, 15 parts modified zinc phosphate, 15 parts silicon carbide micro powder, 70 parts phenolic epoxy resin, and 6 parts additives. The additives include 2 parts wetting and dispersing agent, 0.5 parts defoamer, and 3.5 parts fumed silica (rheology modifier).

[0051] Agent B is a polyamide curing agent with an amine value of 240, the same as in Example 1.

[0052] The glass flakes are 400 mesh, and the ultrafine, high-hardness, wear-resistant filler is 800 mesh.

[0053] The modified zinc phosphate in this embodiment is micro / nano-sheet zinc phosphate modified with silane coupling agent KH560 (KH560-SZP). Its preparation method is as follows: following the dry surface modification method for ultrafine, high-hardness, wear-resistant fillers described in Example 1, the surface of the micro / nano-sheet zinc phosphate is organically modified using silane coupling agent KH560, resulting in a layer of cured, cross-linked silane polymer covering the zinc phosphate surface. This polymer can be efficiently dispersed in epoxy resin, thereby improving the shielding performance and adhesion of the coating, and ultimately enhancing the overall corrosion resistance of the coating.

[0054] The preparation method is the same as in Example 2 (i.e., without using silane coupling agent modification, directly mix to obtain agent A).

[0055] The properties of the coating include: Rust adhesion (pull-off test): approximately 6.5 MPa; Resistance to neutral salt spray: After 1500 hours, the erosion size on one side of the scratched sample is approximately 1.8 mm; Abrasion resistance (Taber CS-17, 1000 rpm / 1kg): abrasion loss 35 mg; Impact resistance: 50 cm·1 kg drop hammer impact, no cracking or peeling of the coating; Single-layer construction thickness: 150~300 μm; Appearance: Dark gray, smooth surface, low gloss.

[0056] Example 4 A composite coating structure, comprising a base coat and a top coat, wherein: The primer uses the same rust-resistant coating formulation as in Example 1, consisting of Agent A and Agent B in a mass ratio of 5:1. Agent A includes the following raw materials in parts by mass: 8 parts tannic acid, 8 parts glass flakes, 12 parts modified zinc phosphate, 10 parts alumina micro powder, 60 parts F-51 phenolic epoxy resin, 15 parts titanium dioxide, and 5 parts additives (1 part silane coupling agent KH-560, 1 part wetting and dispersing agent, 0.5 parts defoamer, and 1.5 parts fumed silica). Agent B is a polyamide curing agent with an amine value of 240, specifically ARADUR® 115 (or an equivalent product that meets the amine value requirement) from Huntsman Corporation.

[0057] The topcoat formulation increases the proportion of ultrafine, high-hardness, wear-resistant filler based on the primer formulation. It consists of Agent A and Agent B in a mass ratio of 5:1. Agent A includes the following raw materials in parts by mass: 8 parts tannic acid, 8 parts glass flakes, 12 parts modified zinc phosphate, 20 parts alumina micro powder, 60 parts F-51 phenolic epoxy resin, 15 parts titanium dioxide, and 6 parts additives (1.5 parts silane coupling agent KH-560, 1.5 parts wetting and dispersing agent, 0.5 parts defoamer, and 2.5 parts fumed silica). Agent B is a polyamide curing agent with an amine value of 240. The amount of wear-resistant filler in the topcoat formulation is adjusted to 20 parts to further improve wear resistance. However, this amount exceeds the preferred range of Agent A formulation in this application and belongs to a variant application in a specific scenario.

[0058] The glass flakes are 400 mesh, and the ultrafine, high-hardness, wear-resistant filler (alumina micro powder) is 800 mesh.

[0059] The modified zinc phosphate used in this embodiment is produced by Henan Taihe Huijin Powder Technology Co., Ltd. (the model can be customized according to needs). This product is a white or light yellow microcrystalline powder with a particle size of 600 mesh (customizable), a P2O5 content of ≥40%, and an oil absorption of <35g / 100g. After being treated with imported additives, it has good wetting and dispersibility in epoxy resin, strong affinity with substrates and polymers, and can effectively improve the shielding performance and adhesion of the coating. Its salt spray resistance can reach more than 600 hours.

[0060] Preparation method: The primer and topcoat are prepared separately according to their respective formulations, with agent A and agent B packaged separately. During construction, mix agent A and agent B of the primer at a ratio of 5:1, apply to the St2 grade stainless steel substrate, and dry to form a film with a dry film thickness of approximately 150μm. After the primer is surface dry (about 2 hours), mix the A and B components of the topcoat at a ratio of 5:1, apply the mixture to the primer, and let it dry to form a film with a dry film thickness of about 150 μm. The total thickness of the composite coating is approximately 300 μm, and it is cured for more than 7 days under standard conditions.

[0061] The properties of the coating include: Rust adhesion (pull-off test): approximately 9 MPa; Interlayer adhesion: approximately 7 MPa; Resistance to neutral salt spray: After 2500 hours, the unilateral erosion size of the scratched sample is approximately 1.5 mm. Abrasion resistance (Taber CS-17, 1000 rpm / 1kg): abrasion loss 22 mg; Impact resistance: 50 cm·1 kg drop hammer impact, no cracking or peeling of the coating; Appearance: Uniform color, smooth surface, gloss slightly lower than in Example 1.

[0062] Example 5 Application of the coating in Example 1 on the floor and equipment base of a chemical plant's concentration workshop.

[0063] The floor and equipment base are subject to acid mist corrosion and frequent wear from forklifts. The traditional repair solution is to sandblast and then apply epoxy mortar, which is time-consuming, costly, and results in significant production downtime losses.

[0064] The coating prepared in Example 1 was used for construction. First, the old rusted steel base and the locally damaged concrete floor were cleaned by St2 level grinding. Then, the mixture of agent A and agent B in Example 1 was sprayed using heavy airless spraying equipment. The dry film thickness of a single coat reached 250 μm.

[0065] The coating can withstand light loads after surface drying and is fully usable after 7 days. A follow-up visit after 18 months of use showed that the coating color remained good, with no corrosion spots, and only slight wear in key areas, with no exposed substrate. Compared to traditional repair methods, this reduces construction time by 60% and direct construction costs by approximately 55%.

[0066] Example 6 The application of the coating in Example 2 on the uniform protection and marking of steel structure columns and ground in a large logistics and warehousing center.

[0067] The A and B agents prepared in Example 2 were used for construction. First, the vertical surfaces of the steel structure columns and the concrete floor were ground to a surface condition equivalent to St2 grade. Then, the construction was carried out in sections: the vertical surfaces of the steel structure columns used A and B agents in a mass ratio of 5.5:1 to extend the construction time, and the concrete floor used A and B agents in a mass ratio of 4.5:1 to accelerate curing.

[0068] It achieved a unified and aesthetically pleasing color scheme for the overall environment, while providing excellent protection and wear resistance on both vertical and horizontal surfaces to match its usage conditions. A follow-up visit after 12 months of use showed that the coating color remained good, with no rust spots, and only slight wear on the main passageway area with no exposed substrate.

[0069] Comparative Example 1 The difference between this comparative example and Example 1 is that no modified zinc phosphate is added to Agent A, while the other preparation methods are the same as in Example 1.

[0070] The measured performance includes: Rust adhesion (pull-off test): approximately 4.5 MPa; Resistance to neutral salt spray: After 800 hours, the erosion size on one side of the scratched sample is approximately 2.5 mm; Abrasion resistance (Taber CS-17, 1000 rpm / 1kg): abrasion loss 42 mg; Impact resistance: 50 cm·1 kg drop hammer impact, the coating shows no cracking or peeling.

[0071] Comparative Example 2 The difference between this comparative example and Example 1 is that: no silane coupling agent is used in Agent A to modify the ultrafine high-hardness wear-resistant filler and glass flakes; the other preparation methods are the same as in Example 1.

[0072] The measured performance includes: Rust adhesion (pull-off test): approximately 4.0 MPa; Resistance to neutral salt spray: After 600 hours, the erosion size on one side of the scratched sample is approximately 2.8 mm; Abrasion resistance (Taber CS-17, 1000 rpm / 1kg): abrasion loss 55 mg; Impact resistance: 40 cm·1 kg drop hammer impact, no cracking or peeling of the coating (micro-cracks appeared during the 50 cm test).

[0073] Comparative Example 3 The difference between this comparative example and Example 1 is that: no modified zinc phosphate is added to Agent A, and no silane coupling agent is used to modify the ultrafine high-hardness wear-resistant filler and glass flakes; the other preparation methods are the same as in Example 1.

[0074] The measured performance includes: Rust adhesion (pull-off test): approximately 2.5 MPa; Resistance to neutral salt spray: After 400 hours, the erosion size on one side of the scratched sample is approximately 3.5 mm. Abrasion resistance (Taber CS-17, 1000 rpm / 1kg): abrasion loss 85 mg; Impact resistance: The coating cracked and peeled off after a 30 cm·1 kg drop hammer impact.

[0075] Comparative Example 4 The difference between this comparative example and Example 1 is that the preparation method does not use the "combination of high-speed dispersion and low-speed stirring" method. Instead, all raw materials (including glass flakes) are added to the dispersion vessel at one time and continuously dispersed at high speed for 30 minutes at a speed of 800~1200 rpm. The other preparation methods are the same as those in Example 1.

[0076] The measured performance includes: Rust adhesion (pull-off test): approximately 5.5 MPa; Resistance to neutral salt spray: After 900 hours, the erosion size on one side of the scratched sample is approximately 2.2 mm; Abrasion resistance (Taber CS-17, 1000 rpm / 1kg): abrasion loss 60 mg; Impact resistance: After a 50 cm·1 kg drop hammer impact, localized micro-cracks appeared in the coating.

[0077] The performance comparison of Comparative Examples 1-3 shows that: Comparative Example 3 (lacking both technical features) has an adhesion of only 2.5 MPa and a salt spray resistance of only 400 hours; Comparative Example 2 (with only modified zinc phosphate added) has an adhesion improved to 4.0 MPa, and Comparative Example 1 (with only silane coupling agent modified filler) has an adhesion improved to 4.5 MPa; while Example 1 (possessing both technical features) has an adhesion of 8.5 MPa. Calculations show that the sum of the improvement effects of the two technical features acting alone is 3.5 MPa (2.0 + 1.5), while the actual improvement effect when both are present is 6.0 MPa (8.5 - 2.5), far exceeding the simple summation, fully demonstrating the synergistic effect.

[0078] The comparison between Comparative Example 4 and Example 1 shows that high-speed dispersion of glass flakes together with other rigid fillers will severely damage the glass flake structure, significantly reduce the shielding effect of the coating, decrease the wear resistance from 28 mg (Example 1) to 60 mg (Comparative Example 4), and significantly reduce the salt spray resistance. This verifies the key role of the stepwise dispersion process of the present invention in maintaining the integrity of the glass flake structure and ensuring the overall performance of the coating.

[0079] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A rust-resistant coating, characterized in that... It consists of agent A and agent B in a mass ratio of (4~6):1; Agent A comprises the following raw materials in parts by weight: 5-12 parts of rust conversion agent, 5-10 parts of glass flakes, 10-15 parts of modified zinc phosphate, 5-15 parts of ultrafine high-hardness wear-resistant filler, 50-70 parts of phenolic epoxy resin, and 2-6 parts of additives. The agent B includes a polyamide curing agent with an amine value of 240-280; The glass flakes are 350-450 mesh, and the ultrafine high-hardness wear-resistant filler is 750-850 mesh.

2. The rust-resistant coating as described in claim 1, characterized in that, The rust conversion agent includes one or more of tannic acid and PBTCA; Alternatively, the ultrafine high-hardness wear-resistant filler may include one or more of alumina and silicon carbide, with a Mohs hardness ≥7.

3. The rust-resistant coating as described in claim 1, characterized in that, The modified zinc phosphate is zinc phosphate with a silane coupling agent surface modified or zinc phosphate with a polymer graft modified.

4. The rust-resistant coating as described in claim 1, characterized in that, The additives include one or more of coupling agents, wetting and dispersing agents, defoamers, and rheology modifiers; Alternatively, Agent A may also contain 0 to 20 parts of coloring pigment, including one or more of titanium dioxide, phthalocyanine blue, iron oxide red, phthalocyanine green, and carbon black.

5. A method for preparing a rust-resistant coating as described in any one of claims 1-4, characterized in that, Including the following steps: A rust-converting agent, glass flakes, modified zinc phosphate, ultrafine high-hardness wear-resistant filler, phenolic epoxy resin, and additives are mixed to obtain Agent A; a polyamide curing agent is used as Agent B to obtain the rust-resistant coating.

6. The preparation method according to claim 5, characterized in that, Add phenolic epoxy resin and additives to a container, and then add ultrafine high-hardness wear-resistant filler, modified zinc phosphate, rust conversion agent and coloring pigment in sequence under high speed stirring, and continue to disperse until the material fineness is ≤30μm; add glass flakes under low speed stirring, and continue stirring for 10~15 minutes; after coating with airless spraying or scraping process, let it stand and level for 5~10 minutes. Alternatively, silane coupling agents can be used to modify the surface of ultrafine high-hardness wear-resistant fillers and glass flakes, respectively. Alternatively, add the coloring pigment to Agent A and mix.

7. The preparation method according to claim 5, characterized in that, The glass flakes are added under low-speed stirring, with a stirring speed of 400-600 rpm and a stirring time of 10-15 minutes.

8. An application of a rust-resistant coating as described in any one of claims 1-4, characterized in that, The process includes the following steps: mixing agent A and agent B, applying the mixture to a stainless steel or concrete substrate, and drying it to form a film.

9. The application as described in claim 8, characterized in that, The rust-resistant steel substrate is of grade St2.

10. The application as described in claim 8, characterized in that, After film formation, it should be cured under standard conditions for more than 7 days.