Acid-resistant high-temperature-resistant anticorrosive coating for ship desulfurization tower and preparation method thereof

Abstract

The invention discloses an acid-resistant high-temperature-resistant anticorrosive coating for a ship desulfurization tower and a preparation method thereof. The acid-resistant high-temperature-resistant anticorrosive coating is prepared by mixing a component A and a component B, the component A is prepared from 25 to 30 parts of modified silicon-fluorine-phenol polymer interwoven resin, 15 to 20 parts of polybutylene terephthalate, 3 to 5 parts of phosphonitrilic chloride trimer, 15 to 20 parts of lamellar fish scale grid anti-corrosion component, 0.1 to 0.2 part of cumyl hydroperoxide, 8 to 12 parts of ceramic metal-based oxide micro powder, 1 to 1.5 parts of nano lanthanum oxide, 1 to 2 parts of nano TiO2, 1 to 1.5 parts of nano cerium oxide, 3 to 5 parts of silicon carbide micro powder, 2 to 3 parts of nano graphite powder and 1 to 1 part of enhancement regulator; 2 parts of a chain extender, 2-3 parts of a chain extender, 6-9 parts of a mixed solvent, 0.3-0.4 part of zinc stearate, 1-2 parts of thiourea and 3-5 parts of composite hybrid fibers. Through the synergistic acid-resistant filler and the composite curing system, the performance advantages of acid resistance, high temperature resistance and erosion resistance are achieved.

Description

Technical Field

[0001] This invention belongs to the field of anti-corrosion coating technology for ship equipment, specifically relating to an acid-resistant and high-temperature-resistant anti-corrosion coating for ship desulfurization towers, as well as its preparation and construction methods. Background Technology

[0002] Ship desulfurization towers and carbon dioxide absorption towers are core equipment for ship exhaust gas treatment, operating under conditions of "high-temperature main engine exhaust (260-300℃, with local transient peaks of 300℃) + acidic desulfurization liquid (containing H2SO4, pH=1-3) + seawater Cl-". - A complex corrosive environment consisting of "concentration ≤5% + SO3 aerosol + salt-containing dust erosion (flow velocity 1.5~3m / s)".

[0003] Existing anti-corrosion coatings for ship desulfurization towers face three major technical bottlenecks: 1. Conflicting properties of base materials: Silicone resin is resistant to high temperature but has poor acid resistance (swells after soaking in H2SO4 solution with pH=1~3 for 10 days), ordinary phenolic resin is resistant to acid but has insufficient high temperature resistance (carbonizes and cracks at 280℃), and unmodified fluoropolymer resin has both acid and temperature resistance but adhesion ≤3MPa (lower than the ≥5MPa standard for marine coatings). 2. Insufficient synergy of fillers: A single filler (such as only mica powder) cannot simultaneously achieve physical shielding and mechanical reinforcement. It will wear through after 2 months of scouring with 300℃ salt dust. The coating life is only 1 to 2 years, which is much shorter than the 5-year single dock repair cycle of a ship. 3. Disjointed evaluation system: The existing standards lack specific evaluations for "high temperature-strong acid alternation" and "salt dust erosion". The coatings that pass the laboratory test fail after 6 to 12 months of ocean voyage (such as peeling off the inner wall of the desulfurization tower and perforation of the weld).

[0004] Therefore, developing an anti-corrosion coating that is "acid-resistant, high-temperature resistant, compatible with fillers, synergistically reinforced, and adaptable to ship operating conditions" has become key to solving the bottleneck of corrosion protection in ship desulfurization towers. This method uses a modified silicone-fluorine-phenol polymer interwoven special resin as a base material, adding layered fish-scale grid anti-corrosion components, ultrafine passivating metal oxides, nano-rare earth element materials, and nano-graphite powder, etc., to prepare a special coating that integrates functions such as acid and alkali resistance, corrosion prevention, prevention of acid and alkali condensation corrosion, prevention of flue gas condensation corrosion, prevention of crystallization salt corrosion, high temperature resistance, waterproofing, damp heat resistance, wear resistance, erosion resistance, non-sticking, and long service life. Summary of the Invention

[0005] To overcome the above-mentioned defects of the prior art, the present invention provides an acid-resistant and high-temperature-resistant anti-corrosion coating for ship desulfurization towers and its preparation method. By optimizing the base material system, synergistic functional fillers and additives, the coating achieves the performance of "resistant to high temperature of 260-300℃ + resistant to strong acid of pH=1-3 + resistant to smoke and dust erosion + long-term protection", which meets the operation and maintenance needs of ship desulfurization towers for more than 5 years.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows.

[0007] This invention discloses an acid-resistant and high-temperature-resistant anti-corrosion coating for ship desulfurization towers, which is prepared by mixing component A (base material-filler system) and component B (curing-anti-aging system) at a mass ratio of 100:(9-12). Component A comprises the following raw materials in parts by weight (total parts are 100): 25-30 parts modified silicone-fluorine-phenol polymer interwoven resin, 15-20 parts polybutylene terephthalate (PBT), 3-5 parts hexachlorocyclotriphosphazene, 15-20 parts layered fish-scale grid anti-corrosion components, 0.1-0.2 parts cumene hydroperoxide, 8-12 parts ceramic metal-based oxide micropowder, 1-1.5 parts nano-lanthanum oxide (La2O3), and nano-TiO2. 1-2 parts, nano-cerium oxide (CeO2) 1-1.5 parts, silicon carbide micro powder 3-5 parts, nano-graphite powder 2-3 parts, reinforcing regulator 1-2 parts, chain extender 2-3 parts, mixed solvent 6-9 parts, zinc stearate 0.3-0.4 parts, thiourea 1-2 parts, composite hybrid fiber 3-5 parts.

[0008] The preparation method of the modified silicone-fluorine-phenol polymer interwoven resin includes the following steps: mixing silicone resin, fluorine resin and phenolic resin in a mass ratio of (4.5-5.5):(2.5-3.5):2 until homogeneous, then adding 0.3%-0.7% of p-toluenesulfonic acid catalyst of the total mass of the three resins, and reacting at 75-85℃ for 2 hours to obtain the product; the silicone resin is a methylphenyl silicone resin prepared by the sol-gel method, with a molecular weight of 5000-8000 and a hydroxyl content of 3%-5%, such as Jia Nuo FJN-9802 high-temperature organosilicon resin; the fluorine resin is polyvinylidene fluoride (PVDF) with a molecular weight of 100000-300000 and a crystallinity of 60%-75%, such as Kynar 761 from Arkema; ​​the phenolic resin has a molecular weight of 1500-3000, a softening point of 90-110℃, and free phenol ≤4.5%, such as 2123 type phenolic resin. The lamellar fish-scale grid anti-corrosion component is a mixture of ≥400-mesh ultrafine glass flakes and ≥200-mesh flake mica powder in a weight ratio of (27-33):1. The ceramic metal-based oxide micro powder is an oxide micro powder composed of Al2O3 and ZrO2 with a particle size of 50-100 nm in a mass ratio of (2.5-3.5):1. The average particle size of the nano-lanthanum oxide is 20-50 nm; the nano-TiO2 is anatase TiO2 with an average particle size of 10-20 nm; the average particle size of the nano-cerium oxide is 30-50 nm; the average particle size of the silicon carbide micro powder is 1-5 μm; and the average particle size of the nano-graphite powder is 10-50 nm, serving as a reinforcing agent and a conductive agent. The enhancing agent is a mixture of aminosilane coupling agent (e.g., KH-550) and titanate coupling agent (e.g., TC-114) in a mass ratio of 1:(0.3 to 0.8); The chain extender is 1,4-butanediol diglycidyl ether, CAS No. 2425-79-8; The mixed solvent is a mixture of propylene glycol methyl ether, ethyl acetate and isopropanol in a volume ratio of (1.5-2.5):1:1; The composite hybrid fiber is a mixture of glass fiber and carbon fiber with a length of 100-200 μm in a mass ratio of 4:(5-7), which is used as a toughening agent to improve the stiffness of the coating.

[0009] Furthermore, the ceramic metal-based oxide micro powder, nano lanthanum oxide, nano TiO2, nano cerium oxide, and silicon carbide micro powder need to be dried before use. The preferred drying method is to place them in a vacuum drying oven and dry them at 105-115°C for at least 2 hours.

[0010] Furthermore, in the acid-resistant and high-temperature-resistant anti-corrosion coating for ship desulfurization towers of the present invention, component A further includes one or more of the following: 0.3-0.5 parts of dispersant, 0.1-0.5 parts of defoamer, and 0.1-0.5 parts of leveling agent; The dispersant is a high molecular weight wetting and dispersing agent for solvent-based coatings, such as DISPERBYK®-163; The defoamer is an organosilicone defoamer, such as BYK®-066 N; The leveling agent is a silicone-containing leveling aid for solvent-based systems, such as BYKETOL®-SPECIAL.

[0011] Component B comprises the following raw materials in parts by weight (total parts are 9 to 12): 3 to 4 parts of amine curing agent, 6 to 8 parts of 4,4'-diaminodiphenyl sulfone, and 1 to 1.5 parts of bis(3,5-tributyl-4-hydroxyphenyl) sulfide; the amine curing agent is a mixture of modified aliphatic amine and polyamide in a mass ratio of (6 to 8):3; Preferably, the modified fatty amine is prepared by a polyetheramine-alkyl glycidyl ether blending modification method, comprising the following steps: first, 55%–65% by mass of fatty amine and 20%–25% by mass of polyetheramine are added to a reaction vessel and stirred and mixed evenly. Then, 15%–20% by mass of alkyl glycidyl ether is slowly added dropwise at a rate of 1–3 mL / min. After the addition is complete, the reaction system is heated to 70–100°C (preferably 80–90°C) and kept at this temperature for 1–3 h (preferably 1.5–2.5 h). After the reaction is completed, the system is naturally cooled to room temperature to obtain a modified fatty amine with a molecular weight of 500–1200. The fatty amine is any one or a mixture of two of dodecyl primary amine and hexadecyl primary amine, preferably a mixture of dodecyl primary amine and hexadecyl primary amine in a mass ratio of (1-2):1; the polyether amine is a polyether amine with a molecular weight of 300-500, preferably a polyether amine with a molecular weight of 400 (D400); the alkyl glycidyl ether is C12-C14 alkyl glycidyl ether (CAS: 68609-97-2, for example, glycidyl 12-14 alkyl ether produced by Nanxing Chemical (Jiangsu) Co., Ltd.); The polyamide is a low molecular weight modified polyamide curing agent with a molecular weight of 500-9000 and a hydroxyl value of 180-220 mgKOH / g, such as Ruichi Chemical's polyamide curing agent 650 (CAS No.: 63428-84-2).

[0012] The present invention discloses a method for preparing an acid-resistant and high-temperature-resistant anti-corrosion coating for a ship desulfurization tower, comprising the following steps: (1) Preparation of component A: S1. Add the formulated amount of mixed solvent to the reactor, start stirring, slowly add the modified silicone-fluorine-phenol polymer interwoven resin, raise the temperature to 50-65°C, and continue stirring until the resin is completely dissolved and homogeneous to obtain a resin solution. S2, an inert gas is introduced into the resin solution, and the temperature is raised to 230-250°C; the polybutylene terephthalate is slowly added, and the mixture is stirred continuously to form a homogeneous mixture; then it is naturally cooled to below 80°C; S3, add the chain extender, reinforcing regulator, zinc stearate and thiourea to the mixture in sequence; stir at 70-80°C to mix thoroughly; S4, add the dispersant to the mixture, stir evenly, and then add the ceramic metal-based oxide micro powder, nano lanthanum oxide, nano TiO2, nano cerium oxide, silicon carbide micro powder, hexachlorocyclotriphosphazene, glass flakes, flake mica powder, and nano graphite powder in sequence; continue stirring evenly to form a mixture; S5, transfer the mixture from S4 to a grinding device for grinding until the material fineness is ≤25μm; return the ground material to the reactor, cool it to below 40℃, and slowly add the nano-graphite powder and composite hybrid fiber while stirring, stirring until the mixture is uniform; vacuum degassing to obtain component A; (2) Preparation of component B: Stir the raw materials at room temperature until they are completely mixed to obtain component B.

[0013] The inert gas is nitrogen or argon, with a flow rate of 50–100 mL / min.

[0014] The present invention discloses a method for constructing an acid-resistant and high-temperature-resistant anti-corrosion coating for a ship desulfurization tower, comprising the following steps: (1) Mixing and maturation: Weigh component A and component B at a mass ratio of 100:(9-12), slowly pour component B into component A; mix evenly by mechanical stirring, and then let stand and mature for 15-30 minutes to obtain acid-resistant and high-temperature resistant coating. (2) Substrate pretreatment: Grind or sandblast the surface of the substrate (carbon steel or stainless steel) of the ship desulfurization tower wall and pipe wall to remove oil stains and rust, wipe it clean with anhydrous ethanol, and let it dry. (3) Coating application: High-pressure airless spraying is used for coating, and a total of 3 layers are sprayed. After each layer is sprayed, it is placed at room temperature until the coating reaches the surface dry state before spraying the next layer. The dry film thickness of each layer is 50-200μm, and the total dry film thickness is 150-600μm. (4) Curing: After the coating is applied, place the coating in a room temperature (23±2℃) and relative humidity of 40%~60% environment for 5~7 days, or bake in an oven at 60±5℃ for 2~3 hours to complete the curing.

[0015] Preferably, in step (3), the nozzle diameter of the high-pressure airless spray gun is 0.5-0.6 mm and the pressure is 15-18 MPa; the surface dry state is when the coating surface reaches a "sticky but not sticky" state, and it takes 30-60 minutes to reach the surface dry state after spraying.

[0016] Compared with the prior art, the beneficial effects of the present invention are: This invention achieves high-temperature resistance of 260-300℃ through the synergy of modified silicone-fluoro-phenol resin and PBT (weight loss ≤1.5% after baking at 300℃ for 2 hours); the combination of ceramic micro powder, nano La2O3 / CeO2 and thiourea ensures that the coating does not swell or peel off after immersion in H2SO4 solution with pH=1-3 for 30 days; the addition of nano graphite powder and composite hybrid fibers improves the resistance to dust erosion (wear ≤50μm after 6 months of erosion by salt dust at 300℃ and 1.5-3m / s), making it fully suitable for the operating conditions of ship desulfurization towers.

[0017] The coating of this invention is applied by high-pressure airless spraying, which is convenient for construction and operation and maintenance, and is suitable for the complex internal structure of desulfurization towers; the surface drying speed is fast (30-60 minutes), which can shorten the construction cycle; after curing, the coating is smooth and non-sticky, reducing smoke and dust residue and reducing the frequency of equipment cleaning; the coating life can reach more than 5 years, matching the single docking cycle of ships, and significantly reducing operation and maintenance costs.

[0018] This invention uses a low-VOCs mixed solvent in small quantities, with a VOCs content of ≤20g / L, which meets the environmental protection requirements for ships. The addition of hexachlorocyclotriphosphazene enhances the flame retardancy of the coating, avoids the risk of fire in the oil and gas environment of ships, and has high safety in use. Detailed Implementation

[0019] The specific embodiments of the present invention will be further described below. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0020] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the experimental materials used in the following embodiments are all available through conventional commercial channels.

[0021] The modified silicone-fluorine-phenol polymer interwoven resin used in Examples 1-3 is prepared by mixing silicone resin, fluorine resin and phenolic resin in a mass ratio of 5:3:2, adding 0.5 parts of p-toluenesulfonic acid catalyst (based on a total mass of 100 parts of the three resins), and then reacting at 80°C for 2 hours. The silicone resin is Jia Nuo FJN-9802 high-temperature silicone resin, the fluorine resin is Arkema Kynar 761, and the phenolic resin is 2123 type phenolic resin.

[0022] The lamellar fish scale grid shielding component consists of ultrafine glass flakes (500 mesh) and flake mica powder (200 mesh) with a weight ratio of 30:1. The ceramic metal-based oxide micro powder is a mixture of Al2O3 and ZrO2 in a mass ratio of 3:1, with a particle size of 50-100 nm; the nano-La2O3 has a particle size of 20-50 nm. Nano-TiO2 is anatase type with a particle size of 10–20 nm; CeO2 has a particle size of 30–50 nm; silicon carbide micropowder has a particle size of 1–5 μm; and nano-graphite has an average particle size of 35 nm and a specific surface area of ​​180 m². 2 / g; dispersant is BYK-163; reinforcing regulator is KH-550:TC-114=1:0.5; mixed solvent is propylene glycol methyl ether: ethyl acetate: isopropanol=2:1:1; composite hybrid fiber is glass fiber: carbon fiber=4:6, length 100~200μm.

[0023] Example 1: Coating adapted to conventional marine desulfurization tower operating conditions 1. Raw material ratio (by weight parts) Component A: 30 parts modified silicone-fluorine-phenol polymer interwoven resin, 15 parts polybutylene terephthalate (PBT), 3 parts hexachlorocyclotriphosphazene, 17 parts layered fish scale grid anti-corrosion component, 0.1 parts cumene hydroperoxide, 8 parts ceramic metal-based oxide micro powder, 1 part nano lanthanum oxide (La2O3), 1 part nano TiO2, 1 part nano cerium oxide (CeO2), 5 parts silicon carbide micro powder, 2 parts nano graphite powder, 0.3 parts dispersant, 1 part reinforcing regulator, 2 parts chain extender, 7.3 parts mixed solvent, 0.3 parts zinc stearate, 1 part thiourea, and 5 parts composite hybrid fiber.

[0024] Component B: 3 parts amine curing agent, 6 parts 4,4'-diaminodiphenyl sulfone, and 1 part bis(3,5-tributyl-4-hydroxyphenyl) sulfide; the amine curing agent is a mixture of modified aliphatic amine and polyamide in a mass ratio of 7:3; The modified fatty amine is prepared by a polyetheramine-alkyl glycidyl ether blending modification method, which includes the following steps: fatty amine, polyetheramine and alkyl glycidyl ether are weighed at mass fractions of 55%, 20% and 15% respectively; the fatty amine and polyetheramine are first added to a reaction vessel and stirred and mixed evenly, and then the alkyl glycidyl ether is slowly added dropwise, controlling the dropping rate to 1-3 mL / min; after the addition is complete, the reaction system is heated to 80°C and kept at this temperature for 2 hours. After the reaction is completed, it is naturally cooled to room temperature to obtain a modified fatty amine with a number average molecular weight of 1000. Among them, the fatty amine is dodecyl primary amine; the polyether amine is polyether amine with a molecular weight of 400 (D400); the alkyl glycidyl ether is C12 to C14 alkyl glycidyl ether (produced by Nanxing Chemical); and the polyamide is polyamide curing agent 650 from Ruichi Chemical.

[0025] 2. A method for preparing an acid-resistant and high-temperature-resistant coating for a ship desulfurization tower, comprising the following steps: (1) Preparation of component A: S1. Add the formulated amount of mixed solvent to the reactor, start stirring, slowly add the modified silicone-fluorine-phenol polymer interwoven resin, raise the temperature to 50-65°C, and continue stirring until the resin is completely dissolved and homogeneous to obtain a resin solution. S2, an inert gas is introduced into the resin solution, and the temperature is raised to 230-250°C; the polybutylene terephthalate is slowly added, and the mixture is stirred continuously to form a homogeneous mixture; then it is naturally cooled to below 80°C; S3, add the chain extender, reinforcing regulator, zinc stearate and thiourea to the mixture in sequence; stir at 70-80°C to mix thoroughly; S4, add the dispersant to the mixture, stir evenly, and then add the ceramic metal-based oxide micro powder, nano lanthanum oxide, nano TiO2, nano cerium oxide, silicon carbide micro powder, hexachlorocyclotriphosphazene, glass flakes, flake mica powder, and nano graphite powder in sequence; continue stirring evenly to form a mixture; S5, transfer the mixture from S4 to a grinding device for grinding until the material fineness is ≤25μm; return the ground material to the reactor, cool it to below 40℃, and slowly add the nano-graphite powder and composite hybrid fiber while stirring, stirring until the mixture is uniform; vacuum degassing to obtain component A; (2) Preparation of component B: Stir the raw materials at room temperature until they are completely mixed to obtain component B.

[0026] 3. The construction method for acid-resistant and high-temperature-resistant coatings for ship desulfurization towers includes the following steps: (1) Mixing and maturation: Weigh component A and component B at a mass ratio of 100:10, slowly pour component B into component A; use a mechanical stirrer to mix at 500 rpm for 13 min, then let it stand and mature for 20 min (to avoid the generation of bubbles) to obtain acid-resistant and high-temperature resistant coating. (2) Substrate pretreatment: Grind or sandblast the surface of the substrate (Q235 carbon steel, sandblasted, Ra50~80μm) of the ship desulfurization tower wall to remove oil and rust, wipe it clean with anhydrous ethanol and let it dry. (3) Coating application: High-pressure airless spraying (spray gun nozzle diameter 0.5mm, pressure 16MPa) is used to apply a total of 3 layers; after each layer is sprayed, it is left at room temperature for 45 minutes until the coating reaches the surface dry state of "sticky but not sticky" before spraying the next layer; the dry film thickness of each layer is 100μm, and the total dry film thickness is 300μm; (4) Curing: After coating, the coating is placed in an environment with a room temperature (23±2℃) and a relative humidity of 40%~60% for 7 days to complete curing. The paint film is tested, and the results are as follows: Table 1 As can be seen from Table 1, Example 1 is a standard formulation for conventional operating conditions. High-temperature stability is achieved through "modified silicone-fluorine-phenol resin + PBT", and an acid-resistant system is constructed using "nano-TiO2 / CeO2 / thiourea". It is suitable for the conventional corrosive environment of ship desulfurization towers at 260-300℃ and pH=1-3. All performance characteristics meet the 5-year operation and maintenance requirements.

[0027] Example 2: Low VOCs environmentally friendly coating (suitable for port environmental protection requirements) 1. Raw material ratio (by weight parts) Component A: 25 parts modified silicone-fluorine-phenol polymer interwoven resin, 15 parts polybutylene terephthalate (PBT), 5 parts hexachlorocyclotriphosphazene, 20 parts layered fish scale grid anti-corrosion component, 0.1 parts cumene hydroperoxide, 9.3 parts ceramic metal-based oxide micro powder, 1 part nano lanthanum oxide (La2O3), 1 part nano TiO2, 1 part nano cerium oxide (CeO2), 5 parts silicon carbide micro powder, 2 parts nano graphite powder, 0.3 parts dispersant, 1 part reinforcing regulator, 2 parts chain extender, 6 parts mixed solvent, 0.3 parts zinc stearate, 1 part thiourea, and 5 parts composite hybrid fiber.

[0028] Component B: 3 parts of amine curing agent, 6 parts of 4,4'-diaminodiphenyl sulfone, and 1 part of bis(3,5-tertiary butyl-4-hydroxyphenyl) sulfide; the amine curing agent is the same as in Example 1.

[0029] 2. The preparation method of the acid-resistant and high-temperature-resistant coating for ship desulfurization towers is the same as in Example 1.

[0030] 3. The construction method for acid-resistant and high-temperature-resistant coatings for ship desulfurization towers includes the following steps: (1) Mixing and maturation: Weigh component A and component B at a mass ratio of 100:10, slowly pour component B into component A; use a mechanical stirrer to mix at 400 rpm for 15 min, then let it stand and mature for 20 min (to avoid the generation of bubbles) to obtain acid-resistant and high-temperature resistant coating. (2) Substrate pretreatment: Grind or sandblast the surface of the substrate (304 stainless steel, sandblasted, Ra50~80μm) of the ship desulfurization tower wall to remove oil and rust, wipe it clean with anhydrous ethanol and let it dry. (3) Coating application: High-pressure airless spraying (spray gun nozzle diameter 0.6mm, pressure 18MPa) is used to apply a total of 3 layers; after each layer is sprayed, it is left at room temperature for 50 minutes until the coating reaches the surface dry state of "sticky but not sticky" before spraying the next layer; the dry film thickness of each layer is 80μm, and the total dry film thickness is 240μm; (4) Curing: After coating, the coating is placed in an environment with a room temperature (23±2℃) and a relative humidity of 40%~60% for 7 days to complete curing. The paint film is tested, focusing on verifying the VOC content and environmental performance. The results are as follows: Table 2 As can be seen from Table 2, Example 2 reduced the amount of low-VOC solvent (from 8 parts to 6 parts) to control the VOC content at 18 g / L, meeting the strict environmental protection requirements of international ports; at the same time, the core acid-resistant and high-temperature resistant components were retained. Although the solvent was reduced, the performance was only slightly reduced due to the optimized dispersion by BYK-163, and it is still suitable for desulfurization towers of near-port ships with medium to low corrosion intensity.

[0031] Example 3: Adaptation to high Cl - Environmental coating formulations 1. Raw material ratio (by weight parts) Component A: 27 parts modified silicone-fluorine-phenol polymer interwoven resin, 18 parts polybutylene terephthalate (PBT), 5 parts hexachlorocyclotriphosphazene, 17 parts layered fish scale grid anti-corrosion component, 0.1 parts cumene hydroperoxide, 10 parts ceramic metal-based oxide micro powder, 1 part nano lanthanum oxide (La2O3), 1 part nano TiO2, 1 part nano cerium oxide (CeO2), 5 parts silicon carbide micro powder, 2 parts nano graphite powder, 0.3 parts dispersant, 1 part reinforcing regulator, 1.3 parts chain extender, 6 parts mixed solvent, 0.3 parts zinc stearate, 1 part thiourea, and 3 parts composite hybrid fiber.

[0032] Component B: 4 parts amine curing agent, 6 parts 4,4'-diaminodiphenyl sulfone, and 1 part bis(3,5-tributyl-4-hydroxyphenyl) sulfide; the amine curing agent is a mixture of modified aliphatic amine and polyamide in a mass ratio of 8:3; The modified fatty amine is prepared by a polyetheramine-alkyl glycidyl ether blending modification method, which includes the following steps: fatty amine, polyetheramine and alkyl glycidyl ether are weighed at mass fractions of 60%, 22% and 18% respectively; the fatty amine and polyetheramine are first added to a reaction vessel and stirred and mixed evenly, and then the alkyl glycidyl ether is slowly added dropwise, controlling the dropwise addition rate to 1-3 mL / min; after the dropwise addition is completed, the reaction system is heated to 85°C and kept at this temperature for 1.7 h. After the reaction is completed, it is naturally cooled to room temperature to obtain a modified fatty amine with a number average molecular weight of 1200. Among them, the fatty amine is a mixture of dodecyl primary amine and hexadecyl primary amine in a mass ratio of 1:1; the polyether amine is a polyether amine with a molecular weight of 400 (D400); the alkyl glycidyl ether is C12 to C14 alkyl glycidyl ether (produced by Nanxing Chemical); and the polyamide is polyamide 650 from Ruichi Chemical.

[0033] 2. The preparation method of the acid-resistant and high-temperature-resistant coating for ship desulfurization towers is the same as in Example 1.

[0034] 3. The construction method for acid-resistant and high-temperature-resistant coatings for ship desulfurization towers includes the following steps: (1) Mixing and maturation: Weigh component A and component B at a mass ratio of 100:11, slowly pour component B into component A; mix with a mechanical stirrer at 400 rpm for 15 min, then let stand and mature for 20 min (to avoid the generation of bubbles) to obtain acid-resistant and high-temperature resistant coating. (2) Substrate pretreatment: Grind or sandblast the surface of the substrate (316L stainless steel, sandblasted, Ra50~80μm) of the ship desulfurization tower wall to remove oil and rust, wipe it clean with anhydrous ethanol and let it dry. (3) Coating application: High-pressure airless spraying (spray gun nozzle diameter 0.6mm, pressure 18MPa) is used to apply a total of 3 layers; after each layer is sprayed, it is left at room temperature for 50 minutes until the coating reaches the surface dry state of "sticky but not sticky" before spraying the next layer; the dry film thickness of each layer is 150μm, and the total dry film thickness is 450μm; (4) Curing: After coating, place the coating in an environment with a room temperature (23±2℃) and a relative humidity of 40%~60% for 7 days to complete curing. Test the paint film to simulate high Cl... - The corrosive environment yielded the following results: Table 3 As can be seen from Table 3, Example 3 enhanced the effect of increasing the dosage of CeO2 (1.5 parts) and thiourea (2 parts) on Cl. - Its adsorption and corrosion inhibition properties make it suitable for ships with high salt spray and high Cl- concentrations. - The working conditions were further verified to ensure the adjustability and environmental adaptability of the formulation of this invention.

[0035] Comparative Example 1: Coating lacking nano-TiO2 and CeO2 (simulating existing single-filler technology) Comparative Example 1 is a comparative example of Example 1, the only difference being that nano TiO2 and CeO2 are not added to component A of Comparative Example 1, while the other components, dosages, preparation methods and application methods are the same as those of Example 1.

[0036] Table 4 Table 4 shows that the absence of nano-TiO2 (catalyzing SO3 conversion) and CeO2 (adsorbing Cl) is a significant factor. - SO4 2- After that, the coating could not resist the synergistic corrosion of acidic media and SO3 aerosol, and its performance declined significantly, revealing the "acid resistance shortcoming" of existing single filler technology.

[0037] Comparative Example 2: Coatings using a single amine curing agent (simulating defects in existing curing systems) Comparative Example 1 is a comparative example of Example 1, except that 4,4'-diaminodiphenyl sulfone is not added to component B of Comparative Example 1, and the amount of amine curing agent is increased to 9 parts (i.e., the total amount of 3 parts of amine curing agent + 6 parts of 4,4'-diaminodiphenyl sulfone in Example 1). The other components, amounts, preparation methods and construction methods are the same as those in Example 1.

[0038] Table 5 As can be seen from Table 5, single amine curing agents (alkaline) are prone to neutralization reactions in strong acid environments, leading to the failure of the crosslinking system; and lack the high-temperature resistant skeleton support of modified aromatic amine 4,4'-diaminodiphenyl sulfone, the coating becomes brittle at high temperatures and has poor aging resistance, thus reproducing the "temperature resistance-acid resistance contradiction" of existing single curing agent technologies.

[0039] The performance of Examples 1-3 was compared with that of Comparative Examples 1-2 to obtain their performance differences, as shown in Table 6.

[0040] Table 6 Performance comparison of Examples 1-3 and Comparative Examples 1-2 As shown in Table 6, this invention, through the technical combination of "synergistic acid-resistant filler (TiO2 / CeO2 / thiourea) + composite curing system (amines + modified aromatic amines)," can adapt to different ship operating conditions (conventional / low VOC / high Cl). - By adjusting the formula, the comprehensive performance advantages of "acid resistance, high temperature resistance and erosion resistance" can be achieved, effectively solving the core defects of existing coatings, and possessing patented innovation and practicality.

Claims

1. An acid-resistant and high-temperature-resistant anti-corrosion coating for ship desulfurization towers, characterized in that, It is prepared by mixing component A and component B at a mass ratio of 100:(9-12); component A includes the following raw materials in parts by weight: 25-30 parts of modified silicone-fluorine-phenol polymer interwoven resin, 15-20 parts of polybutylene terephthalate, 3-5 parts of hexachlorocyclotriphosphazene, 15-20 parts of layered fish scale grid anti-corrosion component, 0.1-0.2 parts of cumene hydroperoxide, 8-12 parts of ceramic metal-based oxide micro powder, 1-1.5 parts of nano lanthanum oxide, and nano TiO2. The composition includes: 1-2 parts of nano-cerium oxide, 1-1.5 parts of silicon carbide micro powder, 3-5 parts of nano-graphite powder, 2-3 parts of reinforcing regulator, 1-2 parts of chain extender, 6-9 parts of mixed solvent, 0.3-0.4 parts of zinc stearate, 1-2 parts of thiourea, and 3-5 parts of composite hybrid fiber; Component B includes the following raw materials in parts by weight: 3-4 parts of amine curing agent, 6-8 parts of 4,4'-diaminodiphenyl sulfone, and 1-1.5 parts of bis(3,5-tertiary butyl-4-hydroxyphenyl) sulfide.

2. The acid-resistant and high-temperature-resistant coating for ship desulfurization towers according to claim 1, characterized in that, The preparation method of the modified silicone-fluorine-phenol polymer interwoven resin includes the following steps: mixing silicone resin, fluorine resin and phenolic resin in a mass ratio of (4.5-5.5):(2.5-3.5):2 until uniform, then adding 0.3%-0.7% of p-toluenesulfonic acid catalyst of the total mass of the three resins, and then reacting at 75-85℃ for 2 hours to obtain the product.

3. The acid-resistant and high-temperature-resistant coating for ship desulfurization towers according to claim 2, characterized in that, The silicone resin is a methylphenyl silicone resin prepared by the sol-gel method, with a molecular weight of 5000-8000 and a hydroxyl content of 3%-5% by mass; the fluororesin is polyvinylidene fluoride with a molecular weight of 100000-300000 and a crystallinity of 60%-75%; the phenolic resin has a molecular weight of 1500-3000, a softening point of 90-110℃, and free phenol ≤4.5%.

4. The acid-resistant and high-temperature-resistant coating for ship desulfurization towers according to claim 1, characterized in that, The layered fish-scale grid anti-corrosion component is a mixture of ≥400-mesh ultrafine glass flakes and ≥200-mesh flake mica powder in a weight ratio of (27-33):1; the ceramic metal-based oxide micro powder is an oxide micro powder composed of Al2O3 and ZrO2 with a particle size of 50-100nm in a mass ratio of (2.5-3.5):

1.

5. The acid-resistant and high-temperature-resistant coating for ship desulfurization towers according to claim 1, characterized in that, The reinforcing agent is a mixture of aminosilane coupling agent and titanate coupling agent in a mass ratio of 1:(0.3-0.8); the chain extender is 1,4-butanediol diglycidyl ether; the mixed solvent is a mixture of propylene glycol methyl ether, ethyl acetate and isopropanol in a volume ratio of (1.5-2.5):1:1; the composite hybrid fiber is a mixture of glass fiber and carbon fiber with a length of 100-200 μm in a mass ratio of 4:(5-7).

6. The acid-resistant and high-temperature-resistant coating for ship desulfurization towers according to claim 1, characterized in that, Component A further includes one or more of the following: 0.3 to 0.5 parts of dispersant, 0.1 to 0.5 parts of defoamer, and 0.1 to 0.5 parts of leveling agent.

7. The acid-resistant and high-temperature-resistant coating for ship desulfurization towers according to claim 1, characterized in that, The amine curing agent is a mixture of modified fatty amine and polyamide in a mass ratio of (6-8):

3.

8. The acid-resistant and high-temperature-resistant coating for ship desulfurization towers according to claim 7, characterized in that, The method for preparing the modified fatty amine includes the following steps: first, 55%–65% by mass of fatty amine and 20%–25% by mass of polyether amine are added to a reaction vessel and stirred until homogeneous. Then, 15%–20% by mass of alkyl glycidyl ether is slowly added dropwise. After the addition is complete, the reaction system is heated to 70–100°C and kept at this temperature for 1–3 hours. After the reaction is completed, the system is naturally cooled to room temperature to obtain a modified fatty amine with a molecular weight of 500–1200.

9. The acid-resistant and high-temperature-resistant coating for ship desulfurization towers according to claim 8, characterized in that, The fatty amine is any one or a mixture of two of dodecyl primary amine and hexadecyl primary amine; the polyether amine is a polyether amine with a molecular weight of 300 to 500; and the alkyl glycidyl ether is a C12 to C14 alkyl glycidyl ether.

10. The acid-resistant and high-temperature-resistant coating for ship desulfurization towers according to claim 7, characterized in that, The polyamide is a low molecular weight modified polyamide curing agent with a molecular weight of 500-9000 and a hydroxyl value of 180-220 mgKOH / g.

11. The method for preparing an acid-resistant and high-temperature-resistant coating for a ship desulfurization tower according to any one of claims 1 to 10, characterized in that, Includes the following steps: (1) Preparation of component A: S1. Add the formulated amount of mixed solvent to the reactor, start stirring, slowly add the modified silicone-fluorine-phenol polymer interwoven resin, raise the temperature to 50-65°C, and continue stirring until the resin is completely dissolved and homogeneous to obtain a resin solution. S2, an inert gas is introduced into the resin solution, and the temperature is raised to 230-250°C; the polybutylene terephthalate is slowly added, and the mixture is stirred continuously to form a homogeneous mixture; then it is naturally cooled to below 80°C; S3, add the chain extender, reinforcing regulator, zinc stearate and thiourea to the mixture in sequence; stir at 70-80°C to mix thoroughly; S4, add the dispersant to the mixture, stir evenly, and then add the ceramic metal-based oxide micro powder, nano lanthanum oxide, nano TiO2, nano cerium oxide, silicon carbide micro powder, hexachlorocyclotriphosphazene, glass flakes, flake mica powder, and nano graphite powder in sequence; continue stirring evenly to form a mixture; S5, transfer the mixture from S4 to a grinding device for grinding until the material fineness is ≤25μm; return the ground material to the reactor, cool it to below 40℃, and slowly add the nano-graphite powder and composite hybrid fiber while stirring, stirring until the mixture is uniform; vacuum degassing to obtain component A; (2) Preparation of component B: Stir the raw materials at room temperature until they are completely mixed to obtain component B.

12. The construction method of the acid-resistant and high-temperature-resistant coating for ship desulfurization towers according to any one of claims 1 to 10, characterized in that, Includes the following steps: (1) Mixing and maturation: Weigh component A and component B at a mass ratio of 100:(9-12), slowly pour component B into component A; mix evenly by mechanical stirring, and then let stand and mature for 15-30 minutes to obtain acid-resistant and high-temperature resistant coating. (2) Substrate pretreatment: Grind or sandblast the surface of the desulfurization tower wall and pipe wall substrate of the ship to remove oil stains and rust, wipe it clean with anhydrous ethanol, and let it dry. (3) Coating application: High-pressure airless spraying is used for coating, and a total of 3 layers are sprayed. After each layer is sprayed, it is placed at room temperature until the coating reaches the surface dry state before spraying the next layer. The dry film thickness of each layer is 50-200μm, and the total dry film thickness is 150-600μm. (4) Curing: After the coating is applied, place the coating in an environment with room temperature and relative humidity of 40% to 60% for 5 to 7 days, or bake it in an oven at 60±5℃ for 2 to 3 hours to complete the curing.

13. The construction method of the acid-resistant and high-temperature-resistant coating for ship desulfurization towers according to claim 12, characterized in that, In step (3), the nozzle diameter of the high-pressure airless spray gun is 0.5-0.6 mm and the pressure is 15-18 MPa; the surface dry state is when the coating surface reaches the state of "sticky but not sticky", and it takes 30-60 minutes to reach the surface dry state after spraying.

Images