Long-acting anticorrosive zinc-rich coating based on three-dimensional network barrier and preparation method of long-acting anticorrosive zinc-rich coating

Abstract

The invention discloses a long-acting anti-corrosion zinc-rich coating based on a three-dimensional network barrier and a preparation method of the long-acting anti-corrosion zinc-rich coating, and belongs to the technical field of metal anti-corrosion coatings. The coating is formed by mixing a component A and a component B, the component A is prepared from the following raw materials: an epoxy resin compound, coated calcium carbonate, conductive graphite powder, a zinc powder compound, modified graphene slurry, hollow glass beads, a dispersing agent, an anti-settling agent, a defoaming agent, butanol, C12-14 alkyl glycidyl ether and xylene; and the component B comprises the following raw materials: xylene, a curing agent, an epoxy resin compound and an accelerant. The coating disclosed by the invention is applied to the surface of a base material in a brush coating, roller coating or spray coating manner, and after the coating is cured, all the components cooperate to construct a three-dimensional network barrier. The coating disclosed by the invention has the characteristics of long-acting corrosion resistance, storage stability, good constructability and good comprehensive performance of the coating.

Description

Technical Field

[0001] This invention relates to the field of metal anti-corrosion coating technology, and in particular to an epoxy zinc-rich coating with high solids content and long-lasting anti-corrosion properties for heavy-duty anti-corrosion applications such as steel structures, wind turbine towers, ships, and bridges, and its preparation method. Background Technology

[0002] According to international standard ISO 12944, in coatings used in harsh atmospheric corrosion environments (C4, C5, CX), zinc-rich coatings, as key primers in heavy-duty anti-corrosion systems, primarily achieve corrosion protection through the cathodic protection of the steel substrate by metallic zinc powder. However, traditional zinc-rich coatings have the following inherent drawbacks: (1) Insufficient cathodic protection continuity: During the corrosion process, zinc powder reacts with oxygen, water, chlorides and other substances in the environment to form zinc salts. These zinc salts accumulate in the coating, causing the coating to expand in volume and increase in resistance, blocking the electrical path and thus causing the cathodic protection to fail prematurely.

[0003] (2) Limited physical shielding effect: Traditional spherical zinc powder forms a porous point contact structure in the coating, and corrosive media can easily penetrate directly into the substrate through the pores.

[0004] (3) Storage and workability issues: High-density zinc powder is prone to settling and clumping in the coating system, affecting storage stability and workability, resulting in uneven coating film.

[0005] While existing technologies attempt to extend the path of corrosive media by adding physical barrier materials such as flaky zinc powder and glass flakes, they often struggle to simultaneously achieve both cathodic protection efficiency and durability. Therefore, developing a zinc-rich coating that synergistically enhances cathodic protection capabilities and physical barrier performance while providing long-lasting corrosion protection has become a pressing technical challenge in this field. Summary of the Invention

[0006] The purpose of this invention is to address the aforementioned shortcomings of existing zinc-rich coatings by providing a long-lasting anti-corrosion zinc-rich coating based on a three-dimensional network barrier and its preparation method.

[0007] To achieve the above objectives, the present invention adopts the following technical solution: A long-lasting anti-corrosion zinc-rich coating based on a three-dimensional network barrier is composed of component A and component B mixed in a mass ratio of (5:1) to (8:1). Component A consists of the following raw materials in parts by weight: 80-120 parts epoxy resin compound, 80-120 parts coated calcium carbonate, 20-30 parts conductive graphite powder, 550-750 parts zinc powder compound, 20-50 parts modified graphene slurry, 10-50 parts hollow glass microspheres, 1-5 parts dispersant, 30-60 parts anti-settling agent, 1-5 parts defoamer, 10-30 parts butanol, 20-40 parts C12-14 alkyl glycidyl ether, and 10-30 parts xylene. Component B consists of xylene, curing agent, epoxy resin compound, and accelerator in a mass ratio of 4:4:1:1.

[0008] Furthermore, the epoxy resin compound is composed of E20 epoxy resin, xylene, butanol, and E54 epoxy resin in a mass ratio of 7:2:1:20.

[0009] Furthermore, the zinc powder compound is prepared by compounding spherical zinc powder and flake zinc powder in a mass ratio of (7:3) to (3:7).

[0010] Furthermore, the modified graphene is prepared from graphene powder, non-floating aluminum powder, epoxy resin compound, dispersant, silane coupling agent, and xylene in a mass ratio of 1:0.6:4:0.1:1:3.3.

[0011] Furthermore, the anti-settling agent is a compound of a biomass anti-settling agent derived from sulfonated castor oil and a polyamide anti-settling agent at a mass ratio of 1:1 to 2.

[0012] The present invention also provides a method for preparing the above-mentioned long-lasting anti-corrosion zinc-rich coating based on a three-dimensional network barrier, comprising the following steps: (1) Preparation of epoxy resin compound: Add E20 epoxy resin, xylene and butanol to a clean reaction vessel, and slowly heat to 80°C at a speed of 300-500 r / min to completely dissolve the material; after the material cools to 10-50°C, add E54 epoxy resin and stir evenly at a speed of 300-500 r / min to obtain the compound. (2) Preparation of modified graphene slurry: Graphene powder, epoxy resin compound, dispersant, silane coupling agent and xylene are added to a dispersion container in sequence. The mixture is fully dispersed to a fineness of ≤40μm using a high-speed disperser at a speed of 800-1200r / min. Then, non-floating aluminum powder is added and stirred until uniform. (3) Preparation of component A: Epoxy resin compound, butanol, C12-14 alkyl glycidyl ether, defoamer and dispersant are put into a dispersion tank and stirred at 300-500 r / min until uniform; under stirring, zinc powder compound, coated calcium carbonate and conductive graphite powder are added in sequence, the speed is increased to 1000-1500 r / min and dispersed for 40-60 minutes until the system is uniform; under stirring at 400-600 r / min, modified graphene slurry, hollow glass microspheres and anti-settling agent are added in sequence and dispersed for 15-25 minutes. The slurry is passed through a 40 mesh sieve and discharged to obtain component A.

[0013] (4) Preparation of component B: Add xylene, curing agent and epoxy resin compound to a container in sequence, stir at low speed of 400-600 r / min and disperse for 40-60 minutes until the system is uniform; seal and let stand overnight, take a sample the next day to test the specific gravity and amine equivalent, and add accelerator after passing the test, stir at 400-600 r / min for 20-40 minutes until uniform; test the amine equivalent and specific gravity, filter after passing the test, and measure and package.

[0014] (5) Coating preparation: Mix component A and component B evenly and let it mature for 15 to 30 minutes to obtain the coating.

[0015] The long-lasting anti-corrosion zinc-rich coating based on a three-dimensional network barrier described above is applied to the substrate surface by brushing, roller coating, or spraying. After the coating cures, the components synergistically construct a three-dimensional network barrier. Specifically, flake zinc powder, non-floating aluminum powder, and flake-structured graphite are arranged in parallel orientation within the coating, forming a layered physical barrier that significantly extends the penetration path of corrosive media. Spherical zinc powder ensures sufficient electrical contact points with the steel substrate, providing an initial and continuous cathodic protection current. Hollow glass microspheres are uniformly dispersed in the coating; their hollow structure not only reduces coating density and improves settling but, more importantly, provides "reserved space" for the accumulation of zinc powder corrosion products, preventing increased internal stress and cracking / peeling due to volume expansion. Graphene, with its huge specific surface area and two-dimensional sheet structure, fills the microscopic gaps between zinc and aluminum powders, further enhancing the coating's density, while its excellent conductivity... It promotes electron transport in the coating and optimizes the cathodic protection circuit. E54 and E20 form a compound epoxy resin system, utilizing the low viscosity of E54 to improve wetting and dispersion, and the excellent mechanical properties of E20 to ensure film strength. The synergy of the two ensures that the resin forms a complete and tough coating on high-content, multi-type functional fillers. Component B forms an addition curing agent that does not produce any small molecule byproducts during the curing process. This characteristic fundamentally guarantees the high density and integrity of the film, laying a solid foundation for achieving long-term corrosion protection exceeding 3000 hours. At the same time, it also provides the coating with excellent adhesion and flexibility, effectively resisting the stress caused by substrate deformation and ensuring the long-term stability of the "three-dimensional barrier network". In addition, its high application tolerance and long service life perfectly match the application requirements of complex functional filler systems, making it a key technology choice for achieving a balance between high performance and high workability.

[0016] Compared with the prior art, the beneficial effects of the present invention are: 1. Long-lasting corrosion protection: By constructing a "three-dimensional network barrier," a synergistic effect of cathodic protection and physical barrier is achieved. The hollow glass microspheres have a perfectly spherical shape, resulting in minimal oil absorption under the same volume conditions. This helps to increase the volume solids content and critical pigment / filler volume content of the coating. Furthermore, due to their spherical structure, similar to a ball bearing, they prevent other fillers with irregular microstructures from rubbing against each other and affecting the fluidity of the coating. Simultaneously, they effectively fill the voids formed by zinc powder in zinc-rich primers, effectively preventing zinc powder sedimentation, resulting in a denser paint film and superior corrosion resistance. The volume effect of the hollow glass microspheres helps improve the dispersion of zinc powder. The "reserved space" design accommodates the expansion of zinc salts, fundamentally solving the coating failure problem caused by zinc salt accumulation. This allows the coating's salt spray resistance to exceed 3000 hours, far exceeding the national standard (600h) and traditional products.

[0017] 2. Balanced and excellent performance: The introduction of aluminum powder into the high-zinc coating creates a mixed phase between the coating and the substrate, resulting in better adhesion, a denser coating, lower corrosion current, and more stable corrosion products that can fill the pores of the coating film, providing excellent shielding and enhancing shielding performance. The spherical zinc powder and graphene ensure excellent conductivity and cathodic protection capabilities. The combination of coated calcium carbonate and conductive graphite powder further improves the overall performance of the coating.

[0018] 3. Stable Storage: By combining sulfonated castor oil derivative biomass anti-settling agent with polyamide anti-settling agent, a strong network structure is formed, which improves the compatibility of coating resin system with zinc powder and aluminum powder, prevents the aggregation of various particles in the system, and is beneficial to the directional arrangement of zinc powder and aluminum powder. It significantly improves the suspension of high specific gravity zinc powder and low specific gravity hollow material, solves the sedimentation problem, and extends the product shelf life.

[0019] 4. Excellent workability: The optimized formula and preparation process give the coating suitable viscosity and thixotropy, effectively preventing sagging during construction. The use of non-floating aluminum powder avoids paint film blooming, ensuring smooth product construction, no spray gun clogging, and guaranteeing the uniformity and density of the coating film.

[0020] 5. Excellent overall coating performance: The E54 / E20 resin system, combined with the addition curing agent, results in strong film adhesion (≥8MPa), moderate drying rate, and balanced mechanical properties. Attached Figure Description

[0021] Figure 1 The results are the pull-out adhesion test results of the samples from Examples 1-3 and Comparative Examples 1-3.

[0022] Figure 2 This is a diagram showing the paint film condition of the sample from Example 1.

[0023] Figure 3 This is a diagram showing the paint film condition of the sample in Example 2.

[0024] Figure 4 This is a diagram showing the paint film condition of the sample in Example 3.

[0025] Figure 5 The image shows the paint film condition of the sample in Comparative Example 1.

[0026] Figure 6 The image shows the paint film condition of the sample in Comparative Example 2.

[0027] Figure 7 The image shows the paint film condition of the sample in Comparative Example 3. Detailed Implementation

[0028] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0029] Example 1 A method for preparing a long-lasting anti-corrosion zinc-rich coating based on a three-dimensional network barrier includes the following steps: (1) Preparation of epoxy resin compound: Add E20 epoxy resin, xylene and butanol to a clean reaction vessel, and slowly heat to 80°C at a speed of 300-500 r / min to completely dissolve the material; after the material cools to 10-50°C, add E54 epoxy resin and stir evenly at a speed of 300-500 r / min to obtain the compound. (2) Preparation of modified graphene slurry: Graphene powder, epoxy resin compound, dispersant, silane coupling agent and xylene are added to a dispersion container in sequence. The mixture is fully dispersed to a fineness of ≤40μm using a high-speed disperser at a speed of 800-1200r / min. Then, non-floating aluminum powder is added and stirred until uniform. (3) Preparation of component A: 120g of epoxy resin compound, 10g of butanol, 30g of C12-14 alkyl glycidyl ether, 3g of defoamer and 3g of dispersant were added to a dispersion tank and stirred at 300r / min until homogeneous. Under stirring, 600g of zinc powder compound, 100g of coated calcium carbonate and 20g of conductive graphite powder were added in sequence, and the speed was increased to 1000r / min and dispersed for 40 minutes until the system was homogeneous. Under stirring at 400r / min, 30g of modified graphene slurry, 30g of hollow glass microspheres, 30g of anti-settling agent and 24g of xylene were added in sequence and dispersed for 15 minutes. The slurry was passed through a 40-mesh sieve and discharged to obtain component A.

[0030] (4) Preparation of component B: Add xylene, curing agent and epoxy resin compound to the container in sequence, stir at low speed of 400 r / min and disperse for 40 minutes until the system is uniform; seal and place overnight, take a sample the next day to test the specific gravity and amine equivalent (amine equivalent controlled at 380-430), after passing the test, add accelerator and stir at 400 r / min for 20 minutes until uniform; test the amine equivalent and specific gravity (amine equivalent controlled at 350-400), filter after passing the test, and measure and package.

[0031] (5) Coating preparation: Mix component A and component B in a ratio of 6:1 until homogeneous, and allow to mature for 15 minutes to obtain the coating.

[0032] In this embodiment, the mass ratio of E20 epoxy resin, xylene, butanol, and E54 epoxy resin used in the preparation of the epoxy resin compound is 7:2:1:20.

[0033] In this embodiment, the modified graphene slurry is prepared with graphene powder, non-floating aluminum powder, epoxy resin compound, dispersant, silane coupling agent, and xylene in a mass ratio of 1:0.6:4:0.1:1:3.3. The dispersant is BYK-110 and the silane coupling agent is KH-560.

[0034] In this embodiment, the zinc powder compound is composed of spherical zinc powder and flake zinc powder in a mass ratio of 7:3.

[0035] In this embodiment, during the preparation of component A, the defoamer is BYK-054, the dispersant is BYK-110, and the anti-settling agent is a mixture of a sulfonated castor oil derivative biomass anti-settling agent and a polyamide anti-settling agent in a mass ratio of 1:1. The sulfonated castor oil derivative biomass anti-settling agent is CRAYVALLAC® MT micronized polyamide modified castor oil derivative rheology modifier, and the polyamide anti-settling agent is Crayvallac ULTRA micronized polyamide wax rheology modifier.

[0036] In this embodiment, when preparing component B, the mass ratio of xylene, curing agent, epoxy resin compound, and accelerator is 4:4:1:1. The curing agent is Huntsman 140 polyamide curing agent, and the accelerator is 2,4,6-tris(dimethylaminomethyl)phenol.

[0037] Example 2 In this embodiment, the preparation steps of the epoxy resin compound are the same as in Example 1.

[0038] In this embodiment, the preparation steps of the modified graphene slurry are the same as in Example 1.

[0039] In this embodiment, the preparation steps of component A are as follows: 100g of epoxy resin compound, 10g of butanol, 20g of C12-14 alkyl glycidyl ether, 3g of defoamer, and 3g of dispersant are added to a dispersion tank and stirred at 500r / min until homogeneous; while stirring, 650g of zinc powder compound, 90g of coated calcium carbonate, and 20g of conductive graphite powder are added sequentially, and the speed is increased to 1500r / min, and the mixture is dispersed for 60 minutes until the system is homogeneous; while stirring at 600r / min, 30g of modified graphene slurry, 20g of hollow glass microspheres, 40g of anti-settling agent, and 14g of xylene are added sequentially, and the mixture is dispersed for 25 minutes. The slurry is then passed through a 40-mesh sieve and discharged to obtain component A.

[0040] In this embodiment, the preparation steps for component B are the same as in Example 1.

[0041] In this embodiment, component A and component B are mixed evenly in a 7:1 ratio and allowed to mature for 15 minutes to obtain a long-lasting anti-corrosion zinc-rich coating based on a three-dimensional network barrier.

[0042] Example 3 In this embodiment, the preparation steps of the epoxy resin compound are the same as in Example 1.

[0043] In this embodiment, the preparation steps of the modified graphene slurry are the same as in Example 1.

[0044] In this embodiment, the preparation steps of component A are as follows: 80g of epoxy resin compound, 10g of butanol, 20g of C12-14 alkyl glycidyl ether, 3g of defoamer, and 3g of dispersant are added to a dispersion tank and stirred at 500r / min until homogeneous; while stirring, 700g of zinc powder compound, 80g of coated calcium carbonate, and 10g of conductive graphite powder are added sequentially, and the speed is increased to 1500r / min, and the mixture is dispersed for 60 minutes until the system is homogeneous; while stirring at 600r / min, 20g of modified graphene slurry, 20g of hollow glass microspheres, 40g of anti-settling agent, and 14g of xylene are added sequentially, and the mixture is dispersed for 25 minutes. The slurry is then passed through a 40-mesh sieve and discharged to obtain component A.

[0045] In this embodiment, the preparation steps for component B are the same as in Example 1.

[0046] In this embodiment, component A and component B are mixed evenly in a ratio of 8:1 and allowed to mature for 15 minutes to obtain a long-lasting anti-corrosion zinc-rich coating based on a three-dimensional network barrier.

[0047] Comparative Example 1 A two-component epoxy zinc-rich anti-corrosion coating differs from Example 1 in that the epoxy resin system uses E54 epoxy resin, and 800-mesh spherical zinc powder is used instead of zinc powder compound.

[0048] Comparative Example 2 A two-component epoxy zinc-rich anti-corrosion coating differs from Example 2 in that the epoxy resin system uses E54 epoxy resin, 800-mesh spherical zinc powder is used instead of zinc powder compound, modified graphene is replaced with conductive graphite powder, and fumed silica is used as the anti-settling agent.

[0049] Comparative Example 3 A two-component epoxy zinc-rich anti-corrosion coating differs from Example 3 in that the epoxy resin system uses E54 epoxy resin, 800-mesh spherical zinc powder is used instead of zinc powder compound, and modified graphene slurry, conductive graphite powder, and hollow glass microspheres are not added. Component B uses an amine curing agent (Hunsmann 140 polyamide curing agent).

[0050] Test Example 1 1. Sample preparation The zinc-rich anti-corrosion coatings from Examples 1-3 and Comparative Examples 1-3 were used for spraying.

[0051] (1) Construction method and parameters: Air spraying is selected, with a nozzle diameter of 1.8 mm and a pressure of 0.3 MPa; (2) Curing conditions and time: ambient temperature 25±2℃, relative humidity 55%±5, performance test after 7 days of standard environmental curing; (3) Coating thickness: For routine physical performance testing, tinplate is used as the substrate with a dry film thickness of 23±3μm; for salt spray resistance, low carbon steel plate is used with a dry film thickness of 90±10μm; for pull-out adhesion, sandblasted steel plate (6mm, medium grade) is used as the substrate with a dry film thickness of 90±10μm.

[0052] 2. Performance test results

[0053] Figure 1 The figures shown are pull-out adhesion test diagrams for Examples 1-3 and Comparative Examples 1-3. Figure 1 a to c are the pull-out adhesion test results of samples from Examples 1 to 3. The breakage location of the pull-out column head is Y:100% (adhesive cohesive failure), and the paint film is not damaged. Figure 1 d to f are the pull-out adhesion test results of comparative examples 1 to 3, and the results are as follows: Comparative Example 1—A / B: 10%, B: 90%, the cohesiveness of the paint film was damaged; Comparative Example 2—A / B: 60%, B: 40%, adhesion between substrate and primer was damaged, and the cohesion of the paint film was destroyed; Comparative Example 3-B: 100%, the cohesion of the paint film was damaged.

[0054] Test Example 2 Samples from Examples 1-3 and Comparative Examples 1-3 were respectively coated onto tinplate substrates. After curing for 24 hours, the coating film condition was observed under a microscope to compare the coating density. The results are as follows: Figures 2-7 As shown.

[0055] Figure 2 The test results showed that the paint film surface of the sample in Example 1 was smooth, the pigments and fillers of various types were evenly distributed, and there was no accumulation or pinholes. Figure 3 The test results showed that the paint film surface of the sample in Example 2 was smooth, the pigments and fillers of various types were evenly distributed, and there was no accumulation or pinholes. Figure 4 The test results showed that the paint film surface of the sample in Example 3 was smooth, the pigments and fillers of various types were evenly distributed, and there was no accumulation or pinholes. Figure 5 The test results showed that the paint film surface of the sample in Comparative Example 1 was uneven, the pigments and fillers were unevenly distributed, and there was accumulation. Figure 6The test results showed that the paint film surface of the sample in Comparative Example 2 was uneven, the pigments and fillers were unevenly distributed and accumulated on the surface, and there were pinholes. Figure 7 The test results showed that the paint film surface of the sample in Comparative Example 3 was relatively smooth, but there was an accumulation problem.

Claims

1. A long-lasting anti-corrosion zinc-rich coating based on a three-dimensional network barrier, characterized in that: It is made by mixing component A and component B in a mass ratio of (5:1) to (8:1); Component A consists of the following raw materials in parts by weight: 80-120 parts epoxy resin compound, 80-120 parts coated calcium carbonate, 20-30 parts conductive graphite powder, 550-750 parts zinc powder compound, 20-50 parts modified graphene slurry, 10-50 parts hollow glass microspheres, 1-5 parts dispersant, 30-60 parts anti-settling agent, 1-5 parts defoamer, 10-30 parts butanol, 20-40 parts C12-14 alkyl glycidyl ether, and 10-30 parts xylene. Component B consists of xylene, curing agent, epoxy resin compound, and accelerator in a mass ratio of 4:4:1:

1.

2. The rare earth-modified high-density thermally conductive and heat-insulating anti-corrosion coating as described in claim 1, characterized in that: The epoxy resin compound is composed of E20 epoxy resin, xylene, butanol, and E54 epoxy resin in a mass ratio of 7:2:1:

20.

3. The rare earth-modified high-density thermally conductive and heat-insulating anti-corrosion coating as described in claim 1, characterized in that: The zinc powder compound is made by compounding spherical zinc powder and flake zinc powder in a mass ratio of (7:3) to (3:7).

4. The rare earth-modified high-density thermally conductive and heat-insulating anti-corrosion coating as described in claim 1, characterized in that: The modified graphene is made from graphene powder, non-floating aluminum powder, epoxy resin compound, dispersant, silane coupling agent, and xylene in a mass ratio of 1:0.6:4:0.1:1:3.

3.

5. The rare earth-modified high-density thermally conductive and heat-insulating anti-corrosion coating as described in claim 1, characterized in that: The anti-settling agent is a compound of a sulfonated castor oil derivative biomass anti-settling agent and a polyamide anti-settling agent in a mass ratio of 1:1 to 2.

6. A method for preparing a long-lasting anti-corrosion zinc-rich coating based on a three-dimensional network barrier as described in any one of claims 1 to 5, characterized in that, Includes the following steps: (1) Preparation of epoxy resin compound: Add E20 epoxy resin, xylene and butanol to a clean reaction vessel, and slowly heat to 80°C at a speed of 300-500 r / min to completely dissolve the material; after the material cools to 10-50°C, add E54 epoxy resin and stir evenly at a speed of 300-500 r / min to obtain the compound. (2) Preparation of modified graphene slurry: Graphene powder, epoxy resin compound, dispersant, silane coupling agent and xylene are added to a dispersion container in sequence. The mixture is fully dispersed to a fineness of ≤40μm using a high-speed disperser at a speed of 800-1200r / min. Then, non-floating aluminum powder is added and stirred until uniform. (3) Preparation of component A: Epoxy resin compound, butanol, C12-14 alkyl glycidyl ether, defoamer and dispersant are put into a dispersion tank and stirred at 300-500 r / min until uniform; under stirring, zinc powder compound, coated calcium carbonate and conductive graphite powder are added in sequence, the speed is increased to 1000-1500 r / min and dispersed for 40-60 minutes until the system is uniform; under stirring at 400-600 r / min, modified graphene slurry, hollow glass microspheres and anti-settling agent are added in sequence and dispersed for 15-25 minutes. The slurry is passed through a 40 mesh sieve and discharged to obtain component A. (4) Preparation of component B: Add xylene, curing agent and epoxy resin compound to a container in sequence, stir at low speed of 400-600 r / min and disperse for 40-60 minutes until the system is uniform; seal and let stand overnight, take a sample the next day to test the specific gravity and amine equivalent, and add accelerator after passing the test, stir at 400-600 r / min for 20-40 minutes until uniform; test the amine equivalent and specific gravity, filter after passing the test, and package by metering. (5) Coating preparation: Mix component A and component B evenly and let it mature for 15 to 30 minutes to obtain the coating.

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