High-crosslinking-density solvent-free anticorrosive paint as well as preparation method and construction method thereof

Abstract

The invention discloses a high-crosslinking-density solvent-free anticorrosive coating as well as a preparation method and a construction method thereof. The coating comprises the following main components in parts by weight: 40-60 parts of bisphenol F epoxy resin, 3-6 parts of gamma-glycidyl ether oxypropyl trimethoxy silane, 2-5 parts of a catechol chelating monomer, 20-30 parts of titanium dioxide, zinc phosphate and mica powder pigments and fillers, 2 parts of silane coupling agent modified nano silicon dioxide, 2 parts of a polyurea rheological additive and 3 parts of a dispersing agent and a defoaming agent. The low-VOC environment-friendly anticorrosive paint is solvent-free (greater than or equal to 95%) and low-VOC environment-friendly anticorrosive paint, the contradiction between sagging and thick coating is solved, the binding force and long-acting corrosion resistance of a coating are improved, meanwhile, the toxicity of free amine is reduced, and the paint has excellent corrosion resistance and construction adaptability and is suitable for being applied to the field of construction. The coating is suitable for heavy-duty anticorrosion fields such as ships, ocean engineering, wind power and harbor machinery, has a wide application prospect, and is beneficial to popularization and application.

Description

Technical Field

[0001] The present invention relates to the technical field of polymer composite materials, and in particular to a solvent-free anti-corrosion coating with high cross-linking density and a preparation method and a construction method thereof. Background Art

[0002] Currently, anti-corrosion coatings can be divided into water-based, solvent-based, and solvent-free types based on the form of the dispersion medium or film-forming substance. Water-based coatings use water as the dispersion medium, are more environmentally friendly, contain fewer volatile organic solvents, and pose less harm to the environment and human health. Common ones include water-based epoxy paints, water-based acrylic paints, etc., which are suitable for scenes with high environmental protection requirements, such as indoor facilities, some outdoor steel structures, etc. Although water-based anti-corrosion paints have low VOC, their corrosion resistance is insufficient and their salt spray resistance is poor; solvent-based anti-corrosion paints use organic solvents (such as toluene, xylene, etc.) as dispersion media, have good film-forming properties, strong adhesion, and stable construction performance. Although solvent-based anti-corrosion paints have good corrosion resistance, they have high VOC, and the volatilization of organic solvents will cause environmental pollution. Most traditional anti-corrosion paints belong to this category, such as solvent-based epoxy paints, chlorinated rubber paints, fluorocarbon paints (solvent-based), etc., which are widely used, especially in the field of heavy corrosion protection; solvent-free anti-corrosion paints do not contain volatile organic solvents, and are mainly composed of liquid resins. They form films through chemical reactions, have excellent environmental protection, and can form thicker coatings in one application, with strong corrosion resistance. For example, solvent-free epoxy coatings and solvent-free polyurethane coatings, etc., but traditional solvent-free anti-corrosion coatings still have many disadvantages in their application in heavy corrosion protection fields such as ships, offshore engineering, wind power and port machinery, such as high viscosity, poor wettability, insufficient cross-linking density, etc. Solvent-free anti-corrosion coatings often sacrifice hardness or wear resistance to reduce viscosity. In terms of construction, some solvent-free anti-corrosion coatings require high-temperature curing, which makes them difficult to use in large-scale on-site construction such as ships. Therefore, there is an urgent need to develop a high-cross-linking density solvent-free anti-corrosion coating with both excellent anti-corrosion performance and construction adaptability, as well as its preparation method and construction method to solve the above technical problems.

[0003] In view of this, the present invention is proposed. Summary of the Invention

[0004] The purpose of the present invention is to provide a high cross-linking density solvent-free anti-corrosion coating and a preparation method and construction method thereof. The solvent-free (≥95%), low-VOC environmentally friendly anti-corrosion coating solves the contradiction between sagging and thick coating, improves the coating adhesion and long-term corrosion resistance, and reduces the toxicity of free amines. It has excellent corrosion resistance and construction adaptability, can be used in heavy corrosion protection fields such as ships, marine engineering, wind power and port machinery, has broad application prospects, and is conducive to promotion and application.

[0005] In order to achieve the above object, the present invention provides a high cross-linking density solvent-free anti-corrosion coating, which comprises the following main components in parts by weight: 40-60 parts of bisphenol F epoxy resin; 3-6 parts of γ-glycidyloxypropyltrimethoxysilane; 2-5 parts of catechol chelate monomer; 20-30 parts of titanium dioxide, zinc phosphate and mica powder pigments and fillers; 2 parts of silane coupling agent modified nano-silica; 2 parts of polyurea rheological additive; 3 parts of dispersant and defoamer; 20 parts of polyetheramine adduct curing agent.

[0006] Preferably, the dispersant is the polymer dispersant Solsporse 37500.

[0007] Preferably, the defoaming agent is silicone-based Tego N or Tego 900.

[0008] Preferably, the polyetheramine adduct curing agent is prepared by prepolymerizing Mannich modified amine T-31 and polyetheramine D230, and then adding epoxy resin for addition, wherein the mass ratio of Mannich modified amine T-31, polyetheramine D230 and epoxy resin is 14:4:2.

[0009] Preferably, the particle size of the silane coupling agent modified nano-silica is 20-50 nm.

[0010] Preferably, the polyurea rheological additive is a polyurethane-modified polyurea thixotropy control additive BYK-410.

[0011] The present invention also provides a method for preparing the above-mentioned high cross-linking density solvent-free anti-corrosion coating, comprising the following steps: (1) First, bisphenol F epoxy resin, γ-glycidyloxypropyltrimethoxysilane and catechol chelate monomer were reacted at 120°C for 2 hours according to the proportion; then, dispersant, silane coupling agent modified nano-silica, titanium dioxide, zinc phosphate, and mica powder were added and dispersed at high speed to a fineness of ≤70μm; finally, polyurea rheological additive and defoamer were added and stirred at low speed to obtain chelate resin; (2) Prepolymerizing Mannich modified amine T-31 and polyetheramine D230 in proportion, and then adding epoxy resin for addition to reduce the content of free amine to obtain a polyetheramine adduct curing agent; (3) Before construction, mix the chelating resin and the polyetheramine adduct curing agent in a ratio of 5:1.

[0012] The present invention also provides a construction method of the above-mentioned high cross-linking density solvent-free anti-corrosion coating, comprising the following steps: (1) Surface treatment: Clean and roughen the surface of the substrate to improve the adhesion of the coating; (2) Coating: Spray, brush or dip the coating evenly on the surface of the substrate; (3) Curing: Curing at room temperature or low temperature to form a solid coating.

[0013] Preferably, in step (3), the curing speed is adjustable by increasing the ratio of active hydrogen equivalent to epoxy equivalent, i.e. increasing the amount of curing agent, to adjust the curing speed so as to achieve surface drying time ≤ 4h and actual drying time ≤ 24h, so as to adapt to the rhythm of segmented ship construction.

[0014] The present invention provides a high cross-linking density solvent-free anti-corrosion coating and a preparation method and construction method thereof, which have the following beneficial effects.

[0015] 1. This invention innovates the resin system, employing an organic-inorganic hybrid resin containing chelating groups. The organic component, bisphenol F epoxy resin, provides flexibility and adhesion, while the inorganic component, silane coupling agent-modified nano-silica, enhances hardness and corrosion resistance. The introduction of the chelating group, catechol, into the resin molecular chain optimizes metal bonding, forming a coordinated bond with the metal substrate. This results in a high crosslink density, addresses cathodic debonding, and significantly improves interfacial bonding.

[0016] 2. This invention optimizes the curing system. The polyetheramine adduct curing agent is prepolymerized with Mannich modified amine T-31 and polyetheramine D230, then added with epoxy resin. The free amine content is less than 0.5% (compared to >2% in conventional products), resulting in a high crosslink density and reduced toxicity, improving the product's workability in low-temperature, high-humidity environments. The curing speed is adjustable by increasing the ratio of active hydrogen equivalents to epoxy equivalents, thereby increasing the curing agent dosage. The curing speed is adjusted to achieve a surface set time of ≤4 hours and a through set time of ≤24 hours, accommodating the staged construction schedule of ships.

[0017] 3. This invention adopts polyurea anti-sagging technology and adds polyurea rheological additives. The viscosity drops sharply under shear force, which is conducive to spraying. It recovers quickly when it is still to prevent sagging. The single wet film thickness can reach 300μm without sagging. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 ad are photos of the cathodic disbonding resistance test of the test samples of Examples 1-4 respectively; Figure 2 ac are respectively photos of the cathodic disbonding resistance test of the test samples of Comparative Examples 1-3; Figure 3 ad are the test photos of pull-out adhesion and salt spray corrosion resistance of the test samples of Examples 1-4 respectively; Figure 4 ac are the pull-out adhesion and salt spray corrosion resistance test photos of the test samples of Comparative Examples 1-3, respectively. DETAILED DESCRIPTION

[0019] The present invention will be further described below with reference to specific embodiments and accompanying drawings to facilitate understanding of the present invention.

[0020] The present invention provides a high cross-linking density solvent-free anti-corrosion coating, which comprises the following main components in parts by weight: 40-60 parts of bisphenol F epoxy resin; 3-6 parts of γ-glycidyloxypropyltrimethoxysilane; 2-5 parts of catechol chelate monomer; 20-30 parts of titanium dioxide, zinc phosphate and mica powder pigments and fillers; 2 parts of silane coupling agent modified nano-silica; 2 parts of polyurea rheological additive; 3 parts of dispersant and defoamer; 20 parts of polyetheramine adduct curing agent.

[0021] Preferably, the dispersant is the polymer dispersant Solsporse 37500. The defoamer is the silicone-based Tego N or Tego 900. The polyetheramine adduct curing agent is prepared by prepolymerizing Mannich-modified amine T-31 and polyetheramine D230, followed by addition of epoxy resin. The mass ratio of Mannich-modified amine T-31, polyetheramine D230, and epoxy resin is 14:4:2. The particle size of the silane coupling agent-modified nanosilica is 20-50 nm. The polyurea rheology modifier is BYK-410, a polyurethane-modified polyurea thixotropy control agent.

[0022] The present invention also provides a method for preparing the above-mentioned high cross-linking density solvent-free anti-corrosion coating, comprising the following steps: (1) First, bisphenol F epoxy resin, γ-glycidyloxypropyltrimethoxysilane and catechol chelate monomer were reacted at 120°C for 2 hours according to the proportion; then, dispersant, silane coupling agent modified nano-silica, titanium dioxide, zinc phosphate, and mica powder were added and dispersed at high speed to a fineness of ≤70μm; finally, polyurea rheological additive and defoamer were added and stirred at low speed to obtain chelate resin; (2) Prepolymerizing Mannich modified amine T-31 and polyetheramine D230 in proportion, and then adding epoxy resin for addition to reduce the content of free amine to obtain a polyetheramine adduct curing agent; (3) Before construction, mix the chelating resin and the polyetheramine adduct curing agent in a ratio of 5:1.

[0023] The present invention also provides a construction method of the above-mentioned high cross-linking density solvent-free anti-corrosion coating, comprising the following steps: (1) Surface treatment: Clean and roughen the surface of the substrate to improve the adhesion of the coating; (2) Coating: Spray, brush or dip the coating evenly on the surface of the substrate; (3) Curing: Curing at room temperature or low temperature to form a strong coating. In step (3), the curing speed is adjustable by increasing the ratio of active hydrogen equivalent to epoxy equivalent, that is, increasing the amount of curing agent, to adjust the curing speed to achieve a surface dry time of ≤4h and a full dry time of ≤24h, so as to adapt to the rhythm of ship segmented construction. Example 1

[0024] 1. Coating formula: 50 parts of bisphenol F epoxy resin; 5 parts of γ-glycidyloxypropyltrimethoxysilane; 3 parts of catechol chelate monomer; 25 parts of titanium dioxide, zinc phosphate and mica powder pigments and fillers; 2 parts of silane coupling agent modified nano-silica; 2 parts of polyurea rheological additive; 3 parts of dispersant and defoamer; 20 parts of polyetheramine adduct curing agent.

[0025] 2. Preparation method: (1) First, bisphenol F epoxy resin (50 parts), γ-glycidyloxypropyltrimethoxysilane (5 parts) and catechol chelate monomer (3 parts) were reacted at 120°C for 2 hours; then, dispersant Solsporse 37500 (2 parts), silane coupling agent modified nano-silica (2 parts), titanium dioxide (12 parts), zinc phosphate (7 parts), and mica powder (6 parts) were added and dispersed at high speed until the fineness was ≤70μm; finally, polyurea rheological agent (2 parts) and defoaming agent Tego N (1 part) were added and stirred at low speed to obtain chelate resin; (2) Prepolymerize Mannich modified amine (T-31, 14 parts) and polyetheramine D230 (4 parts), then add epoxy resin (2 parts) to obtain a polyetheramine adduct curing agent; (3) Before construction, mix the chelating resin and the polyetheramine adduct curing agent in a ratio of 5:1.

[0026] 3. Test results are shown in Table 1 and Figure 1 a. Figure 3 As shown in a: Figure 1 The dot above a is the zinc rod of the sacrificial anode during the cathodic disbonding resistance test, and the dot below is the cathodic disbonding area. The cathodic disbonding resistance diameter in the figure is 4.0 mm (see Table 1). Figure 3 The dots in a are the pull-off adhesion test results. The dots are the peeling areas of the pulling head, and the pull-off adhesion is 13.47 MPa (see Table 1). Figure 3a The entire back is the salt spray corrosion resistance test result. After the test, there is no obvious corrosion damage on the coating surface, and the salt spray corrosion resistance is level 0 (see Table 1).

[0027] Table 1 Test results of Example 1 Example 2

[0028] 1. Coating formula: 50 parts of bisphenol F epoxy resin; 3 parts of γ-glycidyloxypropyltrimethoxysilane; 5 parts of catechol chelate monomer; 25 parts of titanium dioxide, zinc phosphate, and mica powder pigments and fillers; 2 parts of silane coupling agent modified nano-silica; 2 parts of polyurea rheological additive; 3 parts of dispersant and defoamer; 20 parts of polyetheramine adduct curing agent.

[0029] 2. Preparation method: (1) First, bisphenol F epoxy resin (50 parts), γ-glycidyloxypropyltrimethoxysilane (3 parts) and catechol chelate monomer (5 parts) were reacted at 120°C for 2 hours; then, dispersant Solsporse 37500 (2 parts), silane coupling agent modified nano-silica (2 parts), titanium dioxide (12 parts), zinc phosphate (7 parts), and mica powder (6 parts) were added and dispersed at high speed until the fineness was ≤70μm; finally, polyurea rheological agent (2 parts) and defoaming agent Tego N (1 part) were added and stirred at low speed to obtain chelate resin; (2) Prepolymerize Mannich modified amine T-31 (14 parts) and polyetheramine D230 (4 parts), and then add 2 parts of epoxy resin to obtain a polyetheramine adduct curing agent; (3) Before construction, mix the chelating resin and the polyetheramine adduct curing agent in a ratio of 5:1.

[0030] 3. Test results are shown in Table 2 and Figure 1 b. Figure 3 As shown in b: Figure 1 The dot above b is the zinc rod of the sacrificial anode during the cathodic disbonding resistance test, and the dot below is the cathodic disbonding area. The cathodic disbonding resistance diameter in the figure is 4.5 mm (see Table 2). Figure 3 The dots in b are the pull-off adhesion test results. The dots are the peeling areas of the pulling head, and the pull-off adhesion is 13.21 MPa (see Table 2). Figure 3 b The entire back is the salt spray corrosion resistance test result. After the test, there is no obvious corrosion damage on the coating surface, and the salt spray corrosion resistance is level 0 (see Table 2).

[0031] Table 2 Test results of Example 2 Example 3

[0032] 1. Coating formula: 40 parts of bisphenol F epoxy resin; γ-glycidyloxypropyltrimethoxysilane 6 parts; 5 parts of catechol chelate monomer; 30 parts of titanium dioxide, zinc phosphate and masterbatch pigments and fillers; 2 parts of silane coupling agent modified nano-silica; 2 parts of polyurea rheological additive; 3 parts of dispersant and defoamer; 20 parts of polyetheramine adduct curing agent.

[0033] 2. Preparation method: (1) First, bisphenol F epoxy resin (40 parts), γ-glycidyloxypropyltrimethoxysilane (6 parts) and catechol chelate monomer (5 parts) were reacted at 120°C for 2 hours to obtain a chelate resin; then, dispersant Solsporse 37500 (2 parts), silane coupling agent modified nano-silica (2 parts), titanium dioxide (17 parts), zinc phosphate (7 parts), and mica powder (6 parts) were added and dispersed at high speed to a fineness of ≤70 μm; finally, polyurea rheological agent (2 parts) and defoaming agent Tego 900 (1 part) were added and stirred at low speed to obtain a chelate resin; (2) Prepolymerizing Mannich modified amine T-31 (14 parts) and polyetheramine D230 (4 parts), and then adding epoxy resin (2 parts) to obtain a polyetheramine adduct curing agent; (3) Before construction, mix the chelating resin and the polyetheramine adduct curing agent in a ratio of 5:1.

[0034] 3. Test results are shown in Table 3 and Figure 1 c. Figure 3 c: Figure 1 The dot above c is the zinc rod of the sacrificial anode during the cathodic disbonding resistance test, and the dot below is the cathodic disbonding area. The cathodic disbonding resistance diameter in the figure is 5.0 mm (see Table 3). Figure 3 The dots in c are the pull-off adhesion test results. The dots are the peeling areas of the pulling head, and the pull-off adhesion is 11.96 MPa (see Table 3). Figure 3 c The entire back is the salt spray corrosion resistance test result. After the test, there is no obvious corrosion damage on the coating surface, and the salt spray corrosion resistance is level 0 (see Table 3).

[0035] Table 3 Test results of Example 3 Example 4

[0036] 1. Coating formula: 60 parts of bisphenol F epoxy resin; 3 parts of γ-glycidyloxypropyltrimethoxysilane; 2 parts of catechol chelating monomer; 20 parts of titanium dioxide, zinc phosphate and mica powder pigments and fillers; 2 parts of silane coupling agent modified nano-silica; 2 parts of polyurea rheological additive; 3 parts of dispersant and defoamer; 20 parts of polyetheramine adduct curing agent.

[0037] 2. Preparation method: (1) First, bisphenol F epoxy resin (60 parts), γ-glycidyloxypropyltrimethoxysilane (3 parts) and catechol chelate monomer (2 parts) were reacted at 120°C for 2 hours; then, dispersant Solsporse 37500 (2 parts), silane coupling agent modified nano-silica (2 parts), titanium dioxide (12 parts), zinc phosphate (7 parts), and mica powder (6 parts) were added and dispersed at high speed until the fineness was ≤70 μm; finally, polyurea rheological agent (2 parts) and defoaming agent Tego 900 (1 part) were added and stirred at low speed to obtain chelate resin; (2) Prepolymerizing Mannich modified amine T-31 (14 parts) and polyetheramine D230 (4 parts), and then adding epoxy resin (2 parts) to obtain a polyetheramine adduct curing agent; (3) Before construction, mix the chelating resin and the polyetheramine adduct curing agent in a ratio of 5:1.

[0038] 3. Test results are shown in Table 4 and Figure 1 d. Figure 3 d: Figure 1 The dot above d is the zinc rod of the sacrificial anode during the cathodic disbonding resistance test, and the dot below is the cathodic disbonding area. The cathodic disbonding resistance diameter in the figure is 5.0 mm (see Table 4). Figure 3 The dots in d are the pull-off adhesion test results. The dots are the peeling areas of the pulling head, and the pull-off adhesion is 11.89 MPa (see Table 4). Figure 3 d The entire back is the salt spray corrosion resistance test result. After the test, there is no obvious corrosion damage on the coating surface, and the salt spray corrosion resistance is level 0 (see Table 4).

[0039] Table 4 Test results of Example 4

[0040] Comparative Example 1 (no chelating group): 1. Coating formula (eliminating γ-glycidyloxypropyltrimethoxysilane and catechol chelate monomer): 60 parts of bisphenol F epoxy resin; 25 parts of titanium dioxide, zinc phosphate and mica powder pigments and fillers; 2 parts of silane coupling agent modified nano-silica; 2 parts of polyurea rheological additive; 3 parts of dispersant and defoamer; 20 parts of polyetheramine adduct curing agent.

[0041] 2. Preparation method: (1) First, add bisphenol F epoxy resin (60 parts); then add dispersant Solsporse 37500 (2 parts), silane coupling agent modified nano-silica (2 parts); titanium dioxide (12 parts), zinc phosphate (7 parts), and mica powder (6 parts) and disperse at high speed until the fineness is ≤70μm; finally, add polyurea rheological agent (2 parts) and defoaming agent Tego N (1 part), and stir at low speed to obtain resin; (2) Prepolymerizing Mannich modified amine T-31 (14 parts) and polyetheramine D230 (4 parts), and then adding epoxy resin (2 parts) to obtain a polyetheramine adduct curing agent; (3) Before construction, mix the resin and polyetheramine adduct curing agent in a ratio of 5:1.

[0042] 3. Test results are shown in Table 5 and Figure 2 a. Figure 4 As shown in a: Figure 2 The dot above a is the zinc rod of the sacrificial anode during the cathodic disbonding resistance test, and the dot below is the cathodic disbonding area. The cathodic disbonding resistance diameter in the figure is 14.0 mm (see Table 5). Figure 4 The dots in a are the pull-off adhesion test results. The dots are the peeling areas of the pulling head, and the pull-off adhesion is 3.78 MPa (see Table 5). Figure 4 a The entire back is the salt spray corrosion resistance test result. After the test, the coating surface showed severe corrosion damage, including rust spots, bubbles, peeling, and discoloration. The salt spray corrosion resistance was level 4 (see Table 5).

[0043] Table 5 Test results of Comparative Example 1

[0044] Comparative Example 2 (without silane coupling agent): 1. Coating formula (cancel silane coupling agent modified nano-silica): 52 parts of bisphenol F epoxy resin; 3 parts of γ-glycidyloxypropyltrimethoxysilane; 5 parts of catechol chelate monomer; 25 parts of titanium dioxide, zinc phosphate and mica powder pigments and fillers; 2 parts of polyurea rheological additive; 3 parts of dispersant and defoamer; 20 parts of polyetheramine adduct curing agent.

[0045] 2. Preparation method: (1) First, bisphenol F epoxy resin (52 parts), γ-glycidyloxypropyltrimethoxysilane (3 parts) and catechol chelate monomer (5 parts) were reacted at 120°C for 2 hours; then, dispersant Solsporse 37500 (2 parts), titanium dioxide (12 parts), zinc phosphate (7 parts), and mica powder (6 parts) were added and dispersed at high speed until the fineness was ≤70μm; finally, polyurea rheological agent (2 parts) and defoaming agent Tego N (1 part) were added and mixed at low speed to obtain resin; (2) Prepolymerizing Mannich modified amine T-31 (14 parts) and polyetheramine D230 (4 parts), and then adding epoxy resin (2 parts) to obtain a polyetheramine adduct curing agent; (3) Before construction, mix the resin and polyetheramine adduct curing agent in a ratio of 5:1.

[0046] 3. Test results are shown in Table 6 and Figure 2 b. Figure 4 As shown in b: Figure 2 The dot above b is the zinc rod of the sacrificial anode during the cathodic disbonding resistance test, and the dot below is the cathodic disbonding area. The cathodic disbonding resistance diameter in the figure is 13.0 mm (see Table 6). Figure 4 The dots in b are the pull-off adhesion test results. The dots are the peeling areas of the pulling head, and the pull-off adhesion is 4.06 MPa (see Table 6). Figure 4 b The entire back is the salt spray corrosion resistance test result. After the test, the coating surface showed moderate to severe corrosion damage, including rust spots, bubbles, peeling, and discoloration. The salt spray corrosion resistance was level 3 (see Table 6).

[0047] Table 6 Test results of Comparative Example 2

[0048] Comparative Example 3 (without anti-flow aid): 1. Coating formula (excluding polyurea rheological additive): 52 parts of bisphenol F epoxy resin; 3 parts of γ-glycidyloxypropyltrimethoxysilane; 5 parts of catechol chelate monomer; 25 parts of titanium dioxide, zinc phosphate and mica powder pigments and fillers; 2 parts of silane coupling agent modified nano-silica; 3 parts of dispersant and defoamer; 20 parts of polyetheramine adduct curing agent.

[0049] 2. Preparation method: (1) First, bisphenol F epoxy resin (52 parts), γ-glycidyloxypropyltrimethoxysilane (3 parts) and catechol chelate monomer (5 parts) were reacted at 120°C for 2 hours; dispersant Solsporse 37500 (2 parts), silane coupling agent modified nano-silica (2 parts), titanium dioxide (12 parts), zinc phosphate (7 parts), and mica powder (6 parts) were added and dispersed at high speed until the fineness was ≤70μm; finally, defoamer Tego N (1 part) was added and stirred at low speed to obtain resin; (2) Prepolymerizing Mannich modified amine T-31 (14 parts) and polyetheramine D230 (4 parts), and then adding epoxy resin (2 parts) to obtain a polyetheramine adduct curing agent; (3) Before construction, mix the resin and polyetheramine adduct curing agent in a ratio of 5:1.

[0050] 3. Test results are shown in Table 7 and Figure 2 c. Figure 4 c: Figure 2 The dot above c is the zinc rod of the sacrificial anode during the cathodic disbonding resistance test, and the dot below is the cathodic disbonding area. The cathodic disbonding resistance diameter in the figure is 5.5 mm (see Table 7). Figure 4 The dots in c are the pull-off adhesion test results. The dots are the peeling areas of the pulling head, and the pull-off adhesion is 11.88 MPa (see Table 7). Figure 4 c The entire back is the salt spray corrosion resistance test result. After the test, there is no obvious corrosion damage on the coating surface, and the salt spray corrosion resistance is level 0 (see Table 7).

[0051] Table 7 Test results of Comparative Example 3

[0052] It can be seen from Tables 1-7 that compared with Examples 1-4, the sagging limit (wet film) of Comparative Example 3 (without anti-flow aid) is significantly reduced, and compared with Examples 1-4, the pull-off adhesion of Comparative Example 1 (without chelating group) and Comparative Example 2 (without silane coupling agent) is significantly reduced, the cathodic disbonding resistance area is significantly increased, and the salt spray corrosion resistance is significantly reduced.

[0053] Examples 1-4 of the present invention chemically chelate and anchor the metal substrate through chelating groups, resulting in enhanced adhesion, high crosslinking density, and greater than 35% improvement in cathodic disbonding resistance (according to the cathodic protection requirements of GB / T6823, "Ship Ballast Tank Paints," the disbonding at manually missed coatings is reduced from 8mm to less than 5mm). Solvent-free and low-toxicity construction: solids content ≥ 95%, reducing the number of coating passes and improving worker health. Polyurea anti-sagging technology: achieves a single-coat thick coating (320μm), improving construction efficiency by 60% (conventional coatings achieve a single-coat film thickness of 200μm, increasing to 320μm), and adapting to complex structures. Overall performance: salt spray test > 3200h (GB / T 1771). Thus, the high-crosslinking-density solvent-free anti-corrosion coating provided by the present invention is a solvent-free (≥95%), environmentally friendly anti-corrosion coating suitable for applications such as shipbuilding, marine engineering, wind power, and port machinery, combining excellent anti-corrosion performance with ease of application.

[0054] This document uses specific examples to illustrate the inventive concept in detail. The above embodiments are only intended to help understand the core concept of the present invention. It should be noted that any obvious modifications, equivalent substitutions, or other improvements made by a person skilled in the art without departing from the inventive concept should be included within the scope of protection of the present invention.

Claims

1. A high cross-linking density solvent-free anti-corrosion coating, characterized in that: The main components and their weight parts are: 40-60 parts of bisphenol F epoxy resin; 3-6 parts of γ-glycidyloxypropyltrimethoxysilane; 2-5 parts of catechol chelate monomer; 20-30 parts of titanium dioxide, zinc phosphate and mica powder pigments and fillers; 2 parts of silane coupling agent modified nano-silica; 2 parts of polyurea rheological additive; 3 parts of dispersant and defoamer; 20 parts of polyetheramine adduct curing agent.

2. A high cross-linking density solvent-free anti-corrosion coating according to claim 1, characterized in that: The dispersant is a polymer dispersant Solsporse 37500.

3. A high cross-linking density solvent-free anti-corrosion coating according to claim 2, characterized in that: The defoaming agent is silicone-based Tego N or Tego 900.

4. A solvent-free anti-corrosion coating with high cross-linking density according to claim 3, characterized in that: The polyetheramine adduct curing agent is prepared by prepolymerizing Mannich modified amine T-31 and polyetheramine D230, and then adding epoxy resin for addition, wherein the mass ratio of Mannich modified amine T-31, polyetheramine D230 and epoxy resin is 14:4:

2.

5. A high cross-linking density solvent-free anti-corrosion coating according to claim 4, characterized in that: The particle size of the silane coupling agent modified nano-silica is 20-50 nm.

6. The high cross-linking density solvent-free anti-corrosion coating according to claim 5, characterized in that: The polyurea rheological additive is a polyurethane-modified polyurea thixotropy control additive BYK-410.

7. A method for preparing the solvent-free anti-corrosion coating with high cross-linking density according to any one of claims 1 to 6, characterized in that: The steps include: (1) First, bisphenol F epoxy resin, γ-glycidyloxypropyltrimethoxysilane and catechol chelate monomer were reacted at 120°C for 2 hours according to the proportion; then, dispersant, silane coupling agent modified nano-silica, titanium dioxide, zinc phosphate, and mica powder were added and dispersed at high speed to a fineness of ≤70μm; finally, polyurea rheological additive and defoamer were added and stirred at low speed to obtain chelate resin; (2) Prepolymerizing Mannich modified amine T-31 and polyetheramine D230 in proportion, and then adding epoxy resin to obtain a polyetheramine adduct curing agent; (3) Before construction, mix the chelating resin and the polyetheramine adduct curing agent in a ratio of 5:

1.

8. A construction method for the solvent-free anti-corrosion coating with high cross-linking density according to any one of claims 1 to 6, characterized in that: The steps include: (1) Surface treatment: Clean and roughen the surface of the substrate to improve the adhesion of the coating; (2) Coating: Spray, brush or dip the coating evenly on the surface of the substrate; (3) Curing: Curing at room temperature or low temperature to form a solid coating.

9. The construction method of the high cross-linking density solvent-free anti-corrosion coating according to claim 8, characterized in that: In step (3), the curing speed is adjustable by increasing the ratio of active hydrogen equivalent to epoxy equivalent, i.e. increasing the amount of curing agent, to adjust the curing speed so as to achieve surface drying time ≤ 4h and actual drying time ≤ 24h, so as to adapt to the rhythm of segmented ship construction.

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