Rust-containing antirust coating and preparation method thereof

Abstract

The invention relates to the technical field of alkyd resin-based rusty anti-rust coatings, and particularly discloses a rusty anti-rust coating and a preparation method thereof. The on-rust anti-rust coating comprises the following raw materials: composite modified resin, an emulsifier, a filler, an anti-rust pigment and a rust conversion agent, the composite modified resin is prepared by modifying alkyd resin, coumarone resin and polyether polyurethane resin through maleic anhydride; the alkyd resin comprises the following raw materials: polyol, phthalic anhydride, terephthalic acid, soybean oil fatty acid and a high-flash-point aromatic solvent. A composite system of alkyd resin, coumarone resin and polyether polyurethane resin realizes comprehensive improvement of adhesive force, corrosion resistance, constructability and environmental adaptability through advantage complementation, and is matched with an emulsifier, a filler, an anti-rust pigment and a rust conversion agent, so that the adhesive force to a rusty substrate and the corrosion resistance of the coating are remarkably improved, and the service life of the coating is prolonged. And the method has remarkable technical economy and market application potential.

Description

Technical Field

[0001] The invention relates to the technical field of alkyd resin-based rust-proof coatings, in particular to a rust-proof coating and a preparation method thereof. Background Art

[0002] In the field of metal protection, the application of anti-rust coatings is crucial. Anti-rust coatings can effectively delay metal corrosion and extend the service life of metal products. They are widely used in many industries such as construction, machinery, and transportation. At present, during the application of traditional anti-rust coatings, strict rust removal and oil removal and other pretreatments are usually required on the metal surface, such as brushing and polishing. These pretreatment processes are complicated and require a lot of manpower, material resources and time costs. The cost of rust removal is almost twice the cost of the coating itself. In addition, these pretreatments are prone to cause a lot of dust and noise pollution, which is harmful to human health and pollutes the environment. In addition, in some special scenarios, such as high altitude, underwater, and large structural parts, it is difficult to perform thorough rust removal operations.

[0003] Alkyd resin is often used as a base material for anti-rust coatings due to its good film-forming properties, flexibility and adhesion to substrates. Rust-proof paint is a type of paint that can be directly applied to rusty steel surfaces and has certain adhesion and anti-corrosion properties. However, existing alkyd resin-based anti-rust coatings have obvious deficiencies in terms of rust-proof performance: (1) The paint is difficult to effectively penetrate and cover the rust layer, resulting in continued corrosion of the metal under the rust layer and poor anti-rust effect; (2) The active ingredients in some rust-proof paints have poor compatibility with the alkyd resin system, affecting the stability and anti-rust effect of the paint, and cannot meet the demand for long-term rust prevention of metals in complex environments; (3) Alkyd resins also have defects such as high solvent content, poor adhesion to rusty substrates, flammability, and inconvenience in transportation and storage. Therefore, the development of an alkyd resin-based anti-rust coating that can be directly applied to rusty metal surfaces, has excellent anti-rust performance, is safe to store and transport, and has a low solvent content has important practical significance and broad market prospects. Summary of the Invention

[0004] In response to the problems of poor anti-rust effect and poor adhesion to rusted substrates of existing alkyd resin-based rust-proof coatings, the present invention provides a rust-proof coating and a preparation method thereof. The coating adopts alkyd resin, coumarone resin and polyether polyurethane resin as main matrix resins, and is combined with emulsifier, filler, anti-rust pigment and rust-removing agent, thereby significantly improving the adhesion to rusted substrates and the corrosion resistance of the coating.

[0005] In order to solve the above technical problems, the technical solution provided by the present invention is: In a first aspect, the present invention provides a rust-proof coating, comprising the following raw materials in parts by weight: 50 to 60 parts of a composite modified resin, 2 to 6 parts of an emulsifier, 30 to 35 parts of a filler, 20 to 25 parts of an anti-rust pigment, and 3 to 5 parts of a rust-removing agent; The composite modified resin is prepared by modifying alkyd resin, coumarone resin and polyether polyurethane resin with maleic anhydride; the alkyd resin comprises the following raw materials: polyol, phthalic anhydride, terephthalic acid, soybean oil fatty acid and high flash point aromatic hydrocarbon solvent.

[0006] Compared with the prior art, the rust-proof paint provided by the present invention adopts alkyd resin, coumarone resin and polyether polyurethane resin as the main matrix resins. Alkyd resin has excellent adhesion and moldability, can form hydrogen bonds or chemical bonds with the surface of rusty metal substrates, and has good wettability and dispersibility for rust-proof pigments and rust-removing agents, so that the functional components are evenly distributed in the coating, giving full play to the rust-proof effect; coumarone resin is a thermoplastic synthetic resin, which can be used in combination with alkyd resin to increase the cross-linking density of the paint film, reduce the porosity of the paint film, reduce the penetration of corrosive media such as water, oxygen, and salt spray, and significantly improve the hardness of the coating, Wear resistance, rust resistance, and chemical corrosion resistance; polyether-based polyurethane resins incorporate polyurethane segments, giving the coating increased flexibility, crack resistance, weather resistance, and wet surface adaptability. The flexibility of the polyether segments offsets stress on the metal substrate caused by thermal expansion and contraction or rust expansion. The resulting film is tough, flexible, and impact-resistant, adapting to slight deformations of the metal substrate. The urethane groups protect against aging factors such as UV rays and ozone, preventing the coating from powdering and yellowing and extending the anti-rust cycle. The hydrophilicity of the polyether segments ensures good adhesion in humid environments, allowing direct application on rusty and damp metal surfaces. Alkyd resins have insufficient adhesion to loose rust layers and poor salt spray resistance. Single resins are difficult to form films on damp metal surfaces, resulting in a shorter coating life. After being modified with maleic anhydride, the three resins form an interpenetrating network structure through cross-linking and intermolecular forces (such as hydrogen bonds and van der Waals forces). The coumarone resin enhances the interfacial adsorption capacity, and the polyurethane resin fills the pores of the rust layer, forming a dual effect of "mechanical anchoring + chemical bonding". The porosity of the composite paint film is greatly reduced, and the rust is wrapped and passivated, and the adhesion and salt spray resistance are significantly improved; the moisture-curing properties of polyether polyurethane allow construction in an environment with a humidity of ≤85%, which greatly improves the protective life of the composite system and greatly reduces the maintenance frequency and cost.

[0007] The present invention uses terephthalic acid to replace a portion of phthalic anhydride. Terephthalic acid has a small steric hindrance and is easy to react, thereby forming an alkyd resin with a high average molecular weight and a high solid content. On the main chain of the alkyd resin, a certain amount of terephthalic acid replaces the position of phthalic acid, thereby reducing the reactivity of adjacent free hydroxyl groups, increasing rigid benzene rings, and accelerating the self-drying speed of the system in the air. In addition, due to the high solid content of the alkyd resin, a large amount of organic solvent is not required, and the VOC content and the volatilization of organic matter in the entire system can be effectively reduced, thereby saving resources and reducing environmental pollution.

[0008] Preferably, the alkyd resin comprises the following raw materials in percentage by weight: 11% to 15% polyol, 16% to 19% phthalic anhydride, 2% to 4% terephthalic acid, 45% to 55% soybean oil fatty acid, 0.1% to 0.2% catalyst and 14% to 20% high flash point aromatic hydrocarbon solvent.

[0009] In the alkyd resin, polyols provide hydroxyl groups, and phthalic anhydride provides carboxyl groups. The hydroxyl and carboxyl groups condense to form a resin skeleton with a network structure. The soybean oil fatty acid has long-chain alkyl groups, which are used to adjust the properties of the alkyd resin. The catalyst accelerates the polycondensation reaction, and the high-flash-point aromatic solvent can adjust the solid content and viscosity of the alkyd resin. The present invention controls the amount of each raw material in the alkyd resin to exert the synergistic effect of each raw material, thereby producing an alkyd resin with a high solid content and low viscosity. This eliminates the need to add too much solvent during paint production, produces a large amount of film-forming material during brushing or spraying, and the paint film has good color and gloss retention. It also improves the permeability, wettability, and rust resistance of the composite modified resin.

[0010] Further preferably, the molar ratio of hydroxyl groups to carboxyl groups in the raw materials of the alkyd resin is (1.1-1.2):1.

[0011] In the present invention, excessive hydroxyl groups can avoid excessive cross-linking reaction, thereby ensuring the viscosity of the alkyd resin.

[0012] Preferably, the polyol includes glycerol, trimethylolpropane, sorbitol and castor oil.

[0013] Further preferably, the mass ratio of glycerol, trimethylolpropane, sorbitol and castor oil is (4-5):(3-4):(1-2):1.

[0014] Glycerol has a symmetrical hydroxyl distribution, high reactivity, and a tendency to form a network structure. Trimethylolpropane contains methyl side chains, which provide significant steric hindrance and improve the resin's weather resistance, water resistance, and drying properties. Sorbitol, a sugar alcohol with six hydroxyl groups and a high molecular weight, enhances the resin's flexibility and solids content, improving its copolymerization compatibility with fatty acids. Castor oil, containing hydroxy fatty acids, can directly participate in the polycondensation reaction, imparting excellent flexibility and drying properties to the resin. These four ingredients, when combined in specific ratios, maximize their respective benefits and enhance the overall performance of alkyd resins.

[0015] Further preferably, the catalyst comprises p-toluenesulfonic acid.

[0016] Illustratively, soybean oil fatty acids are obtained from refined soybean oil.

[0017] Preferably, the high flash point aromatic hydrocarbon solvent includes 1000# solvent oil or 1500# solvent oil.

[0018] Preferably, the preparation method of the alkyd resin comprises the following steps: Add polyol, phthalic anhydride, terephthalic acid and soybean oil fatty acid into a reactor, stir and melt, add a catalyst, and carry out low-temperature polymerization reaction at 180°C~200°C. When the acid value of the reaction system drops to 20mgKOH / g~30mgKOH / g, raise the temperature to 220°C~230°C for high-temperature polymerization reaction. When the acid value of the reaction system drops to below 15mgKOH / g, cool to 100°C~120°C, add a high-flash point aromatic hydrocarbon solvent for swelling, and obtain alkyd resin.

[0019] More preferably, the stirring and melting temperature is 120° C. to 140° C., and the stirring and melting time is 0.5 h to 1 h.

[0020] More preferably, the temperature is raised to 180° C. to 200° C. at a rate of 5° C. / min to 10° C. / min, and the holding time of the low-temperature polymerization reaction is 3 h to 4 h.

[0021] For example, the acid value can be measured by titration. The acid value of the reaction system is measured once every hour, and when it approaches the target value, it is measured every 30 minutes.

[0022] More preferably, the swelling time is 30 min to 40 min.

[0023] Preferably, the alkyd resin has a solid content of 68% to 72%, a format viscosity of 20s to 30s, an acid value of ≤15 mgKOH / g, and a closed cup flash point of >60°C.

[0024] For example, after the swelling is completed, the following steps may be performed: cooling the temperature to 80° C. to 90° C., controlling the viscosity of the liquid system to be 20s to 30s (at 25° C.); filtering the liquid while hot using a 100-mesh filter to remove impurities; cooling the liquid to room temperature, and measuring the solid content.

[0025] Measure viscosity using a rotational viscometer (e.g., NDJ-4, 25°C, rotor 6). Determine solids content using the oven method (weigh 1 g of sample and dry at 120°C for 2 hours; solids content = residue weight / sample weight × 100%). If the solids content is less than 68%, remove some of the high-flash-point aromatic solvent by vacuum distillation. If the solids content is greater than 72%, dilute with additional high-flash-point aromatic solvent. Multiple calibrations are required for both viscosity and solids content.

[0026] Preferably, the composite modified resin comprises the following raw materials in parts by mass: 28 to 32 parts of alkyd resin, 16 to 20 parts of coumarone resin, 5 to 8 parts of polyether polyurethane resin, and 0.4 to 0.8 parts of maleic anhydride.

[0027] Preferably, the softening point of the coumarone resin is 70°C to 80°C.

[0028] Preferably, the softening point of the polyether polyurethane resin is 80°C to 100°C.

[0029] The present invention uses coumarone resin and polyether-type polyurethane resin with specific softening points to enhance their polymerization ability with alkyd resin, thereby effectively improving the permeability of the resin substrate. The present invention does not limit the specific types of coumarone resin and polyether-type polyurethane resin, as long as they meet the softening point requirements.

[0030] Preferably, the preparation method of the composite modified resin comprises the following steps: The alkyd resin is melted, and coumarone resin, polyether polyurethane resin and maleic anhydride are added thereto, and the reaction is carried out at 200°C to 220°C to obtain a composite modified resin.

[0031] More preferably, the melting temperature is 100°C to 120°C.

[0032] More preferably, the reaction time is 1 h to 2 h.

[0033] Preferably, the emulsifier includes isopropyl alcohol and sodium C12~C18 alkylbenzene sulfonate.

[0034] Further preferably, the emulsifier comprises: 2 to 5 parts of isopropyl alcohol and 0.1 to 1 part of sodium C12 to C18 alkylbenzene sulfonate.

[0035] Further preferably, the C12~C18 sodium alkylbenzene sulfonate includes sodium dodecylbenzene sulfonate (SDBS).

[0036] For example, the preparation method of the emulsifier comprises the following steps: Isopropyl alcohol and sodium C12-C18 alkylbenzene sulfonate are dispersed and dissolved at high speed to obtain an emulsifier.

[0037] Isopropyl alcohol, with its low surface tension, low viscosity, and high permeability, diffuses rapidly into the oil-water interface, reducing interfacial diffusion resistance and allowing the composite modified resin and anti-rust particles to contact and adhere to the metal substrate. Sodium C12-C18 alkylbenzene sulfonate, an anionic surfactant, contains hydrophilic sulfonic acid groups and hydrophobic C12-C18 alkylbenzene chains in its molecular structure. These molecules can align at the oil-water interface, reducing interfacial tension and dispersing oil droplets into fine droplets. The hydroxyl groups of isopropyl alcohol hydrogen bond with the hydrophilic groups (sulfonate groups) of sodium C12-C18 alkylbenzene sulfonate, enhancing its solubility in water. Furthermore, the hydrophobic alkyl chains insert into the hydrophobic layer of the emulsifier, reducing electrostatic repulsion between surfactant molecules and creating a tighter interfacial film. This further reduces surface tension, enhances emulsification efficiency, and improves the wettability of the composite modified resin emulsion for pigments and fillers and its penetration into rusted substrates.

[0038] Preferably, the filler includes organic bentonite and nano-ultrafine barium sulfate.

[0039] Further preferably, the filler comprises: 1 to 2 parts of organic bentonite and 28 to 33 parts of nano-ultrafine barium sulfate.

[0040] In the present invention, the specific filler not only has a filling effect on the pores of the rusty metal substrate, making the paint film more dense, but also has anti-settling and anti-sagging functions, which can further improve the rust resistance and water resistance of the coating.

[0041] Preferably, the anti-rust pigment comprises an inorganic pigment and a high-efficiency corrosion inhibitor.

[0042] Further preferably, the anti-rust pigment comprises: 13 parts to 17 parts of inorganic pigment and 5 parts to 10 parts of high-efficiency corrosion inhibitor.

[0043] More preferably, the inorganic pigment includes at least one of red iron oxide or iron titanium powder.

[0044] Further preferably, the high-efficiency corrosion inhibitor includes molybdate, zinc salt and silicate.

[0045] More preferably, the mass ratio of the molybdate, the zinc salt and the silicate is (5-8):(2-3):(1-2).

[0046] More preferably, the molybdate includes at least one of sodium molybdate or ammonium molybdate.

[0047] More preferably, the zinc salt comprises zinc oleate.

[0048] More preferably, the silicate includes at least one of sodium metasilicate or potassium water glass.

[0049] In the present invention, the components of the high-efficiency corrosion inhibitor can react with substances such as rust or water on the surface of the metal substrate to generate molybdate compounds, zinc hydroxide precipitates, and silicate hydrate protective films with corrosion inhibition properties, forming a mixed passivation film, which covers and protects the surface of the rusted substrate, thereby slowing down corrosion and preventing impurities in the water from being precipitated on the surface of the metal substrate. Even in the case of an ultra-thin coating, it has excellent rust prevention and salt spray resistance, meeting the secondary protection requirements after the paint film is applied. At the same time, the specific high-efficiency corrosion inhibitor also has good stability, further passivates the metal substrate, prevents metal corrosion, and is highly efficient, non-toxic, and environmentally friendly.

[0050] Further preferably, the preparation method of the high-efficiency corrosion inhibitor comprises the following steps: Dissolving molybdate and silicate in water to form an inorganic salt aqueous solution; adding zinc salt to a high flash point aromatic hydrocarbon solvent to form a zinc salt solution; The inorganic salt aqueous solution is added to the zinc salt solution to obtain a high-efficiency corrosion inhibitor.

[0051] More preferably, the mass concentration of the inorganic salt aqueous solution is 15% to 30%.

[0052] More preferably, the mass concentration of the zinc salt solution is 20% to 40%.

[0053] Preferably, the rust-reducing agent includes aminocarboxylic acid chelating agents, hydroxycarboxylic acid chelating agents, sulfur-containing organic chelating agents and polycarboxylic acid chelating agents.

[0054] Further preferably, the mass ratio of the aminocarboxylic acid chelating agent, the hydroxycarboxylic acid chelating agent, the sulfur-containing organic chelating agent and the polycarboxylic acid chelating agent is (3-5):(2-3.5):(1-2):1.

[0055] Aminocarboxylic acid chelating agents mainly chelate Fe 3+ Too high a ratio may cause the viscosity of the system to increase, affecting construction, while too low a ratio will slow down the rust conversion rate; hydroxycarboxylic acid chelating agents are used to adjust the acidity and provide film-forming hydroxyl groups, and work synergistically with aminocarboxylic acid chelating agents. Too high a ratio can easily lead to brittleness of the film layer in the later stage; sulfur-containing organic chelating agents enhance the adhesion of the film layer through thiol groups. Too high a ratio may introduce odor and increase costs, while too low a ratio will result in insufficient bonding strength of the protective layer; polycarboxylic acid chelating agents form films through large molecules. Too high a ratio will reduce the permeability of the system, while too low a ratio will fail to form a complete protective layer.

[0056] More preferably, the aminocarboxylic acid chelating agent includes at least one of ethylenediaminetetraacetic acid (EDTA) or hydroxyethylethylenediaminetriacetic acid (HEDTA).

[0057] More preferably, the hydroxycarboxylic acid chelating agent includes at least one of gluconic acid or citric acid.

[0058] Further preferably, the sulfur-containing organic chelating agent includes thioglycolic acid.

[0059] More preferably, the polycarboxylic acid chelating agent includes polymaleic anhydride.

[0060] Specific rust removers are organic macromolecular chelating agents that can react chemically with rust. They contain strong coordination groups such as hydroxyl, carboxyl, amino, and thiol. They can complex and dissolve the iron ions in rust through chelation. 3+ Coordinate to form a stable five-membered or six-membered ring chelate; polymaleic anhydride (PMA) contains conjugated double bonds and anhydride groups, which generate polymaleic acid after hydrolysis. The carboxyl group chelates with iron ions and is adsorbed on the surface of the metal substrate to inhibit corrosion.

[0061] Further preferably, the preparation method of the rust-removing agent comprises the following steps: Dissolve the aminocarboxylic acid chelating agent and the hydroxycarboxylic acid chelating agent in water, adjust the pH value of the liquid system to 2-2.5, add the sulfur-containing organic chelating agent, the polycarboxylic acid chelating agent and the film-forming aid in sequence at 30-40°C, adjust the pH value of the liquid system to 2.5-3, and obtain the rust-removing agent.

[0062] The present invention first dissolves the aminocarboxylic acid chelating agent and the hydroxycarboxylic acid chelating agent in water (if the dissolution is difficult, it can be heated to 40°C~50°C), adjusts the pH of the liquid system to 2~2.5, forms a transparent acidic solution, and the chelating agent fully dissociates the coordination group; after adding the sulfur-containing organic chelating agent, the thiol and Fe 3+ Initial coordination; after adding the polycarboxylic acid chelating agent, the small molecular chelate is cross-linked into a network structure by utilizing the adsorption effect of the macromolecular chain; the pH of the liquid system is adjusted to 2.5~3, which can take into account both acidic rust removal and film stability to form a stable rust removal agent.

[0063] Extensive testing has revealed that the pH of the liquid system needs to be controlled between 1.5 and 3.0. A pH too low may corrode the metal substrate, while a pH too high may result in insufficient rust dissolution. The temperature should not exceed 50°C when adding thioglycolic acid (a sulfur-containing organic chelating agent) to prevent oxidation and inactivation of the thiol groups. The temperature of polymaleic anhydride (a polycarboxylic acid chelating agent) can be appropriately raised to 40°C during dissolution to promote macromolecular chain stretching. Phosphoric acid or acetic acid can be used to adjust the pH of the liquid system.

[0064] More preferably, the film-forming aid includes triethanolamine.

[0065] More preferably, the amount of the film-forming aid is 5% to 10% of the mass of the rust-removing agent.

[0066] A specific amount of film-forming aid can improve the adhesion of the chelating film.

[0067] Preferably, the density of the rust-removing agent is 1.05 g / cm 3 ~1.15g / cm 3 , format viscosity is 10s~20s.

[0068] For example, the amount of water used is about 60%~75% of the mass of the rust remover. The specific amount is based on the density and viscosity of the rust remover.

[0069] Preferably, the rust-proof paint further comprises the following raw materials: a high-flash-point aromatic hydrocarbon solvent, a metal drier and an additive.

[0070] Further preferably, the high flash point aromatic hydrocarbon solvent includes 1000# solvent oil or 1500# solvent oil.

[0071] The composite modified resin in the present invention can be used in conjunction with a low-VOC solvent to provide slow drying for the coating, allowing the paint liquid sufficient penetration time. At the same time, the high-flash-point aromatic solvent has a high flash point (>60°C) and is non-flammable, thereby improving the safety of storage and transportation.

[0072] Further preferably, the metal drier includes composite drier TY-CQ 160 (purchased from Shanghai Taoyuan Cobalt Industry Co., Ltd.).

[0073] More preferably, the auxiliary agent includes an adhesion promoter, a dispersant and a defoaming agent.

[0074] More preferably, the adhesion promoter includes 3-glycidoxypropyltrimethoxysilane.

[0075] The preferred adhesion promoter is epoxy silane oligomer, which has a cross-linking effect and can significantly improve the adhesion between the composite modified resin and the rust layer and the metal substrate.

[0076] For example, the adhesion promoter may be Brilliance New Material HC-H560.

[0077] The present invention has no special requirements for dispersants and defoamers; conventional types in the art can be selected, such as two to three brands in combination. Dispersants include at least one of Shanghai Yuanhe Chemical's Verapon B110, Rogers PORON's NC, Shanghai Zhongyi Chemical's DP-610, Evonik's GA-100, and Arkema's Coadis 790. Defoamers include at least one of Tego 843, BYK 011, Shanghai Zhongyi Chemical's DF-208, and Evonik's Foamex 812.

[0078] Further preferably, the rust-proof coating comprises the following raw materials in parts by mass: 28 to 32 parts of alkyd resin, 16 to 20 parts of coumarone resin, 5 to 8 parts of polyether polyurethane resin, 0.4 to 0.8 parts of maleic anhydride, 2 to 5 parts of isopropyl alcohol, 0.1 to 1 part of sodium C12 to C18 alkylbenzene sulfonate, 5 to 10 parts of high flash point aromatic hydrocarbon solvent, 1 to 2 parts of organic bentonite, 28 to 33 parts of nano-ultrafine barium sulfate, 1 to 2 parts of adhesion promoter, 0.3 to 1 part of dispersant, 0.1 to 0.5 parts of defoaming agent, 5 to 10 parts of high-efficiency corrosion inhibitor, 13 to 17 parts of inorganic pigment, 0.1 to 1 part of metal drying agent and 3 to 5 parts of rust removal agent.

[0079] The present invention limits the amount of each raw material of the rust-proof paint, which can achieve a synergistic effect, thereby maximizing the effect of each raw material. It can be directly constructed on the rusty metal surface, eliminating the need for sandblasting and grinding to remove rust, saving labor time and costs. With a thin coat of paint, it still has excellent anti-rust and anti-corrosion properties, a plump paint film, a low solvent content, and is safe to store and transport.

[0080] In a second aspect, the present invention provides a method for preparing the rust-proof coating, comprising the following steps: S1. Mix the composite modified resin and emulsifier, add a high flash point aromatic solvent, filler, anti-rust pigment and additives, and grind to obtain a paint slurry; S2. Add a metal drier and a rust-removing agent to the paint slurry, mix them evenly, and obtain a rust-proof paint.

[0081] Preferably, in S1, the number of grinding times is 1 to 2 times.

[0082] Preferably, in S1, the particle size of the paint slurry is ≤20 μm.

[0083] For example, in S2, after uniform mixing, the method further includes: adjusting the viscosity with a high-flash-point aromatic solvent, and filtering with a 120-mesh filter to obtain the rust-proof coating.

[0084] Preferably, the viscosity of the rust-proof paint is 70KU~80KU.

[0085] The rust-proofing paint provided by the present invention can be used for the anti-corrosion decoration of metal components that need maintenance and renovation, such as steel structures, equipment, pipelines, bridges, etc.

[0086] Compared with the prior art, the present invention has the following beneficial effects: (1) The composite system of alkyd resin, coumarone resin and polyether polyurethane resin has achieved comprehensive improvement in adhesion, corrosion resistance, workability and environmental adaptability through complementary advantages, and has significant technical and economic benefits and market application potential.

[0087] (2) The present invention obtains a high-solid-content, low-viscosity alkyd resin by limiting the polyol in the alkyd resin and combining it with other raw materials. The alkyd resin has excellent permeability after being compounded with other resins, which significantly improves the anti-rust effect of the coating.

[0088] (3) The various components in a specific high-efficiency corrosion inhibitor are used in combination to exert the synergistic effect of each component. For example, zinc ions have a cathodic polarization effect, and molybdate has an anodic passivation effect. The two can form a "cathode and cathode dual protection" film, further improving the corrosion inhibition effect.

[0089] (4) Aminocarboxylic acid chelating agents have strong chelating ability and high affinity for iron ions; hydroxycarboxylic acid chelating agents can adjust the acidity, promote the dissolution of rust, and provide hydroxyl groups for film formation; the S group in the sulfur-containing organic chelating agent forms a covalent bond with the iron ion, enhancing the adhesion of the film layer; the macromolecular chain in the polycarboxylic acid chelating agent can be firmly adsorbed on the surface of the metal substrate to form a long-lasting protective layer.

[0090] (5) The rust-proof paint provided by the present invention has a super strong permeability of the composite modified resin through the design of the resin substrate, which can make the rust-proof paint penetrate into the loose rust layer, tightly wrap the rust, and effectively separate the substrate from the rust, the substrate from the external medium, and the rust from the external medium, thereby achieving an anti-corrosion effect; the emulsifier can reduce the surface tension of the paint film, allowing the paint film to quickly penetrate the rust coating and improve the adhesion of the paint film; the rust-proof pigment can form difficult-to-dissolve complex polyacid coordination compounds with the reactive groups of the composite modified resin and the rust components. These complex polyacid coordination compounds are very difficult to dissolve, thereby preventing the further diffusion of rust and achieving the purpose of stabilizing rust. At the same time, these complex polyacid coordination compounds can become one of the filler components of the coating, so that the paint film has better physical and mechanical properties and anti-rust and anti-corrosion properties; the rust-transforming agent can chemically react with the rust components to convert the rust into chelates or complexes. These chelates and complexes can protect the metal substrate. DETAILED DESCRIPTION

[0091] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0092] In this invention, deionized water was used, the metal drier was composite drier TY-CQ 160, the adhesion promoter was HC-H560 from Huachen New Materials, the dispersant was a blend of equal quality Verapon B110 from Shanghai Yuanhe Chemical and DP-610 from Shanghai Zhongyi Chemical, and the defoamer was a blend of equal quality Tego 843 and BYK 011 from BYK Chemical. All materials unless otherwise specified were commercially available.

[0093] Example 1 This embodiment provides a rust-proof coating, comprising the following raw materials in parts by mass: 30 parts of alkyd resin, 18 parts of coumarone resin, 7 parts of polyether polyurethane resin, 0.6 parts of maleic anhydride, 4 parts of isopropyl alcohol, 0.5 parts of sodium dodecylbenzene sulfonate, 8 parts of 1000# solvent oil, 1.5 parts of organic bentonite, 30 parts of nano-ultrafine barium sulfate, 1.5 parts of adhesion promoter, 0.6 parts of dispersant, 0.3 parts of defoaming agent, 8 parts of high-efficiency corrosion inhibitor, 15 parts of inorganic pigment (red iron oxide), 0.5 parts of metal drying agent, and 4 parts of rust removal agent.

[0094] The alkyd resin includes the following raw materials in percentage by weight: 13% of polyol, 18% of phthalic anhydride, 3% of terephthalic acid, 50% of soybean oil fatty acid, 0.1% of p-toluenesulfonic acid and 15.9% of 1000# solvent oil.

[0095] The molar ratio of hydroxyl groups to carboxyl groups in the raw materials of the alkyd resin is 1.15:1, and the polyol is composed of glycerol, trimethylolpropane, sorbitol and castor oil in a mass ratio of 4:3:1.5:1.

[0096] The softening point of coumarone resin is 75°C, and the softening point of polyether polyurethane resin is 90°C.

[0097] The high-efficiency corrosion inhibitor includes molybdate (sodium molybdate), zinc salt (zinc oleate) and silicate (sodium metasilicate) in a mass ratio of 6:2.5:1.5.

[0098] The rust-removing agent includes an aminocarboxylic acid chelating agent (EDTA), a hydroxycarboxylic acid chelating agent (gluconic acid), a sulfur-containing organic chelating agent (thioglycolic acid) and a polycarboxylic acid chelating agent (polymaleic anhydride) in a mass ratio of 4:3:1.5:1.

[0099] The preparation method of the above-mentioned rust-proof coating comprises the following steps: S100, preparation of alkyd resin: Weigh all raw materials according to the designed ratio, add polyol, phthalic anhydride, terephthalic acid and soybean oil fatty acid into the reactor, stir and melt at 130℃; Then, p-toluenesulfonic acid was added, and the temperature was raised to 190°C at a rate of 8°C / min to carry out low-temperature polymerization reaction, and the temperature was kept for 3.5 hours, during which the acid value of the reaction system was monitored in real time; When the acid value of the reaction system drops to 25 mgKOH / g, the temperature is raised to 225°C for high-temperature polymerization. When the acid value of the reaction system drops below 15 mgKOH / g, the temperature is lowered to 110°C, 1000# solvent oil is added for swelling, and the stirring time is 35 minutes. The temperature was continued to drop to 85°C, and after the viscosity of the liquid system was controlled to be 25s (25°C), the mixture was filtered while hot, cooled to room temperature, and the solid content was tested and fine-tuned to obtain the alkyd resin.

[0100] After testing, the solid content of the alkyd resin is 70%, the format viscosity is 25s, the acid value is ≤15mgKOH / g, and the closed cup flash point is >60℃.

[0101] S200, preparation of composite modified resin: The alkyd resin was melted at 110°C, coumarone resin, polyether polyurethane resin and maleic anhydride were added, and the reaction was carried out at 210°C. After keeping the temperature for 1.5 hours, a composite modified resin was obtained.

[0102] S300, preparation of emulsifier: Disperse and dissolve isopropyl alcohol and sodium dodecylbenzenesulfonate at high speed to obtain an emulsifier.

[0103] S400, a method for preparing a high-efficiency corrosion inhibitor comprises the following steps: Dissolve molybdate and silicate in water to form a 22wt% inorganic salt aqueous solution; add zinc salt to 1000# solvent oil to form a 30wt% zinc salt solution; Adding an inorganic salt solution into a zinc salt solution can produce a highly effective corrosion inhibitor.

[0104] S500, preparation of rust removal agent: Dissolve the aminocarboxylic acid chelating agent and the hydroxycarboxylic acid chelating agent in water at 45°C (the amount of water is about 65% of the mass of the rust remover), adjust the pH of the liquid system to 2, add the sulfur-containing organic chelating agent, the polycarboxylic acid chelating agent and triethanolamine in sequence at 35°C (the amount of triethanolamine is 8% of the mass of the rust remover), adjust the pH of the liquid system to 2.5, and obtain a density of 1.1 g / cm 3 , rust remover with a viscosity of 15s.

[0105] It should be noted that this embodiment does not limit the order of S200 to S500.

[0106] S600, Preparation of rust-proof coating: Weigh all raw materials according to the designed ratio, mix the composite modified resin and emulsifier, add 1000# solvent oil, organic bentonite, adhesion promoter, dispersant, defoamer, high-efficiency corrosion inhibitor, nano-ultrafine barium sulfate and inorganic pigment, grind to obtain a paint slurry with a particle size of ≤20μm; Add metal drying agent and rust-removing agent to the paint slurry, mix well, use 1000# solvent oil to adjust the viscosity, filter, and obtain rust-proof paint with a viscosity of 75KU.

[0107] Example 2 This embodiment provides a rust-proof coating, comprising the following raw materials in parts by mass: 28 parts of alkyd resin, 20 parts of coumarone resin, 6 parts of polyether polyurethane resin, 0.5 parts of maleic anhydride, 3 parts of isopropyl alcohol, 0.7 parts of sodium dodecylbenzene sulfonate, 7 parts of 1000# solvent oil, 1 part of organic bentonite, 32 parts of nano-ultrafine barium sulfate, 1.6 parts of adhesion promoter, 0.8 parts of dispersant, 0.4 parts of defoaming agent, 5 parts of high-efficiency corrosion inhibitor, 17 parts of inorganic pigment (equal weight of red iron oxide and iron titanium powder), 0.1 parts of metal drying agent, and 3 parts of rust removal agent.

[0108] The alkyd resin includes the following raw materials in percentage by weight: 12% of polyol, 17% of phthalic anhydride, 3.2% of terephthalic acid, 51% of soybean oil fatty acid, 0.1% of p-toluenesulfonic acid and 16.7% of 1000# solvent oil.

[0109] The molar ratio of hydroxyl groups to carboxyl groups in the raw materials of the alkyd resin is 1.12:1, and the polyol is composed of glycerol, trimethylolpropane, sorbitol and castor oil in a mass ratio of 4.5:3.5:1.5:1.

[0110] The softening point of coumarone resin is 70°C, and the softening point of polyether polyurethane resin is 85°C.

[0111] The high-efficiency corrosion inhibitor includes molybdate (ammonium molybdate), zinc salt (zinc oleate) and silicate (potassium water glass) in a mass ratio of 5:3:1.

[0112] The rust-removing agent includes an aminocarboxylic acid chelating agent (HEDTA), a hydroxycarboxylic acid chelating agent (citric acid), a sulfur-containing organic chelating agent (thioglycolic acid) and a polycarboxylic acid chelating agent (polymaleic anhydride) in a mass ratio of 3:2.5:2:1.

[0113] The preparation method of the above-mentioned rust-proof coating comprises the following steps: S100, preparation of alkyd resin: Weigh all raw materials according to the designed ratio, add polyol, phthalic anhydride, terephthalic acid and soybean oil fatty acid into the reactor, stir and melt at 140℃; Then, p-toluenesulfonic acid was added, and the temperature was raised to 180°C at a rate of 5°C / min to carry out low-temperature polymerization reaction, and the temperature was kept for 4 hours, during which the acid value of the reaction system was monitored in real time; When the acid value of the reaction system drops to 20 mgKOH / g, the temperature is raised to 220°C for high-temperature polymerization. When the acid value of the reaction system drops below 15 mgKOH / g, the temperature is lowered to 100°C, 1000# solvent oil is added for swelling, and the stirring time is 40 minutes. The temperature was continued to drop to 80°C, and after the viscosity of the liquid system was controlled to be 20s (25°C), the mixture was filtered while hot, cooled to room temperature, and the solid content was tested and fine-tuned to obtain the alkyd resin.

[0114] After testing, the solid content of the alkyd resin is 68%, the format viscosity is 20s, the acid value is ≤15mgKOH / g, and the closed cup flash point is >60℃.

[0115] S200, preparation of composite modified resin: The alkyd resin was melted at 120°C, coumarone resin, polyether polyurethane resin and maleic anhydride were added, and the reaction was carried out at 220°C. After keeping the temperature for 1 hour, a composite modified resin was obtained.

[0116] S300, preparation of emulsifier: Disperse and dissolve isopropyl alcohol and sodium dodecylbenzenesulfonate at high speed to obtain an emulsifier.

[0117] S400, a method for preparing a high-efficiency corrosion inhibitor comprises the following steps: Dissolve molybdate and silicate in water to form a 30wt% inorganic salt aqueous solution; add zinc salt to 1000# solvent oil to form a 20% zinc salt solution; Adding an inorganic salt solution into a zinc salt solution can produce a highly effective corrosion inhibitor.

[0118] S500, preparation of rust removal agent: Dissolve the aminocarboxylic acid chelating agent and the hydroxycarboxylic acid chelating agent in water at 40°C (the amount of water is about 75% of the mass of the rust remover), adjust the pH of the liquid system to 2.5, add the sulfur-containing organic chelating agent, the polycarboxylic acid chelating agent and triethanolamine in sequence at 40°C (the amount of triethanolamine is 5% of the mass of the rust remover), adjust the pH of the liquid system to 3, and obtain a density of 1.05g / cm 3 , rust remover with a viscosity of 20s.

[0119] It should be noted that this embodiment does not limit the order of S200 to S500.

[0120] S600, Preparation of rust-proof coating: Weigh all raw materials according to the designed ratio, mix the composite modified resin and emulsifier, add 1000# solvent oil, organic bentonite, adhesion promoter, dispersant, defoamer, high-efficiency corrosion inhibitor, nano-ultrafine barium sulfate and inorganic pigment, grind to obtain a paint slurry with a particle size of ≤20μm; Add metal drying agent and rust-removing agent to the paint slurry, mix well, use 1000# solvent oil to adjust the viscosity, filter, and obtain rust-proof paint with a viscosity of 70KU.

[0121] Example 3 This embodiment provides a rust-proof coating, comprising the following raw materials in parts by mass: 32 parts of alkyd resin, 19.2 parts of coumarone resin, 8 parts of polyether polyurethane resin, 0.8 parts of maleic anhydride, 5 parts of isopropyl alcohol, 1 part of sodium dodecylbenzene sulfonate, 10 parts of 1000# solvent oil, 2 parts of organic bentonite, 28 parts of nano-ultrafine barium sulfate, 1 part of adhesion promoter, 0.3 parts of dispersant, 0.1 parts of defoaming agent, 7 parts of high-efficiency corrosion inhibitor, 13 parts of inorganic pigment (red iron oxide), 1 part of metal drying agent, and 5 parts of rust removal agent.

[0122] The alkyd resin includes the following raw materials in percentage by weight: 15% of polyol, 16% of phthalic anhydride, 4% of terephthalic acid, 45.8% of soybean oil fatty acid, 0.2% of p-toluenesulfonic acid and 19% of 1000# solvent oil.

[0123] The molar ratio of hydroxyl groups to carboxyl groups in the raw materials of the alkyd resin is 1.2:1, and the polyol is composed of glycerol, trimethylolpropane, sorbitol and castor oil in a mass ratio of 5:4:1:1.

[0124] The softening point of coumarone resin is 80°C, and the softening point of polyether polyurethane resin is 100°C.

[0125] The high-efficiency corrosion inhibitor includes molybdate (sodium molybdate), zinc salt (zinc oleate) and silicate (equal weights of sodium metasilicate and potassium water glass) in a mass ratio of 7:2:2.

[0126] The rust-removing agent includes an aminocarboxylic acid chelating agent (EDTA), a hydroxycarboxylic acid chelating agent (citric acid), a sulfur-containing organic chelating agent (thioglycolic acid) and a polycarboxylic acid chelating agent (polymaleic anhydride) in a mass ratio of 4:2:1:1.

[0127] The preparation method of the above-mentioned rust-proof coating comprises the following steps: S100, preparation of alkyd resin: Weigh all raw materials according to the designed ratio, add polyol, phthalic anhydride, terephthalic acid and soybean oil fatty acid into the reactor, stir and melt at 120℃; Then, p-toluenesulfonic acid was added, and the temperature was raised to 200°C at a rate of 10°C / min to carry out low-temperature polymerization reaction, and the temperature was kept for 3 hours, during which the acid value of the reaction system was monitored in real time; When the acid value of the reaction system drops to 30 mgKOH / g, the temperature is raised to 230°C for high-temperature polymerization. When the acid value of the reaction system drops below 15 mgKOH / g, the temperature is lowered to 120°C, 1000# solvent oil is added for swelling, and the stirring time is 30 minutes. The temperature was continued to drop to 90°C, and after the viscosity of the liquid system was controlled to be 30s (25°C), the mixture was filtered while hot, cooled to room temperature, and the solid content was tested and fine-tuned to obtain the alkyd resin.

[0128] After testing, the solid content of the alkyd resin is 72%, the format viscosity is 30s, the acid value is ≤15mgKOH / g, and the closed cup flash point is >60℃.

[0129] S200, preparation of composite modified resin: The alkyd resin was melted at 100°C, coumarone resin, polyether polyurethane resin and maleic anhydride were added, and the reaction was carried out at 200°C. After keeping the temperature for 2 hours, a composite modified resin was obtained.

[0130] S300, preparation of emulsifier: Disperse and dissolve isopropyl alcohol and sodium dodecylbenzenesulfonate at high speed to obtain an emulsifier.

[0131] S400, a method for preparing a high-efficiency corrosion inhibitor comprises the following steps: Dissolve molybdate and silicate in water to form a 15% inorganic salt aqueous solution; add zinc salt to 1000# solvent oil to form a 20% zinc salt solution; Adding an inorganic salt solution into a zinc salt solution can produce a highly effective corrosion inhibitor.

[0132] S500, preparation of rust removal agent: Dissolve the aminocarboxylic acid chelating agent and the hydroxycarboxylic acid chelating agent in water at 50°C (the amount of water is about 60% of the mass of the rust remover), adjust the pH of the liquid system to 2, add the sulfur-containing organic chelating agent, the polycarboxylic acid chelating agent and triethanolamine in sequence at 30°C (the amount of triethanolamine is 10% of the mass of the rust remover), adjust the pH of the liquid system to 2.5, and obtain a density of 1.15 g / cm 3 , rust remover with a viscosity of 10s.

[0133] It should be noted that this embodiment does not limit the order of S200 to S500.

[0134] S600, Preparation of rust-proof coating: Weigh all raw materials according to the designed ratio, mix the composite modified resin and emulsifier, add 1000# solvent oil, organic bentonite, adhesion promoter, dispersant, defoamer, high-efficiency corrosion inhibitor, nano-ultrafine barium sulfate and inorganic pigment, grind to obtain a paint slurry with a particle size of ≤20μm; Add metal drying agent and rust-removing agent to the paint slurry, mix well, use 1000# solvent oil to adjust the viscosity, filter, and obtain rust-proof paint with a viscosity of 80KU.

[0135] Example 4 This embodiment provides a rust-proof coating, comprising the following raw materials in parts by mass: 28.6 parts of alkyd resin, 16 parts of coumarone resin, 5 parts of polyether polyurethane resin, 0.4 parts of maleic anhydride, 2 parts of isopropyl alcohol, 0.1 parts of sodium dodecylbenzene sulfonate, 5 parts of 1000# solvent oil, 2 parts of organic bentonite, 33 parts of nano-ultrafine barium sulfate, 2 parts of adhesion promoter, 1 part of dispersant, 0.5 parts of defoaming agent, 10 parts of high-efficiency corrosion inhibitor, 15 parts of inorganic pigment (iron titanium powder), 1 part of metal drying agent, and 5 parts of rust removal agent.

[0136] The alkyd resin includes the following raw materials in percentage by weight: 11% of polyol, 19% of phthalic anhydride, 2% of terephthalic acid, 53.9% of soybean oil fatty acid, 0.1% of p-toluenesulfonic acid and 14% of 1000# solvent oil.

[0137] The molar ratio of hydroxyl groups to carboxyl groups in the raw materials of the alkyd resin is 1.1:1, and the polyol is composed of glycerol, trimethylolpropane, sorbitol and castor oil in a mass ratio of 4:3:2:1.

[0138] The softening point of coumarone resin is 75°C, and the softening point of polyether polyurethane resin is 80°C.

[0139] The high-efficiency corrosion inhibitor includes molybdate (equal weights of sodium molybdate and ammonium molybdate), zinc salt (zinc oleate) and silicate (sodium metasilicate) in a mass ratio of 8:3:1.

[0140] The rust-removing agent includes an aminocarboxylic acid chelating agent (HEDTA), a hydroxycarboxylic acid chelating agent (gluconic acid), a sulfur-containing organic chelating agent (thioglycolic acid) and a polycarboxylic acid chelating agent (polymaleic anhydride) in a mass ratio of 4:3.5:2:1.

[0141] The preparation method of the above-mentioned rust-proof coating is the same as that in Example 1 and will not be repeated here.

[0142] Example 5 This embodiment provides a rust-proof coating, which is similar to Example 1, except that the raw material polyol of the alkyd resin is composed of equal weights of pentaerythritol and diethylene glycol. The remaining components and contents are the same as in Example 1 and are not repeated here.

[0143] The preparation method of the above-mentioned rust-proof coating comprises the following steps: S100, preparation of alkyd resin: Weigh all raw materials according to the designed ratio, add polyol, phthalic anhydride, terephthalic acid and soybean oil fatty acid into the reactor, stir and melt at 130℃; Then, p-toluenesulfonic acid was added, and the temperature was raised to 190°C at a rate of 8°C / min to carry out low-temperature polymerization reaction, and the temperature was kept for 3.5 hours, during which the acid value of the reaction system was monitored in real time; When the acid value of the reaction system drops to 25 mgKOH / g, the temperature is raised to 225°C for high-temperature polymerization. When the acid value of the reaction system drops below 15 mgKOH / g, the temperature is lowered to 110°C, 1000# solvent oil is added for swelling, and the stirring time is 35 minutes. The temperature was continued to drop to 85°C, and after the viscosity of the liquid system was controlled to be 45s (25°C), the mixture was filtered while hot, cooled to room temperature, and the solid content was tested and fine-tuned to obtain the alkyd resin.

[0144] S200 to S600 are the same as S200 to S600 in Example 1 and will not be described in detail.

[0145] Example 6 This embodiment provides a rust-proof coating, which is similar to Example 1, except that the raw material polyol of the alkyd resin is composed of equal weights of glycerol and trimethylolpropane. The remaining components and contents are the same as in Example 1 and are not repeated here.

[0146] The preparation method of the above-mentioned rust-proof coating comprises the following steps: S100, preparation of alkyd resin: Weigh all raw materials according to the designed ratio, add polyol, phthalic anhydride, terephthalic acid and soybean oil fatty acid into the reactor, stir and melt at 130℃; Then, p-toluenesulfonic acid was added, and the temperature was raised to 190°C at a rate of 8°C / min to carry out low-temperature polymerization reaction, and the temperature was kept for 3.5 hours, during which the acid value of the reaction system was monitored in real time; When the acid value of the reaction system drops to 25 mgKOH / g, the temperature is raised to 225°C for high-temperature polymerization. When the acid value of the reaction system drops below 15 mgKOH / g, the temperature is lowered to 110°C, 1000# solvent oil is added for swelling, and the stirring time is 35 minutes. The temperature was continued to drop to 85°C, and after the viscosity of the liquid system was controlled to be 38s (25°C), the mixture was filtered while hot, cooled to room temperature, and the solid content was tested and fine-tuned to obtain the alkyd resin.

[0147] S200 to S600 are the same as S200 to S600 in Example 1 and will not be described in detail.

[0148] Example 7 This embodiment provides a rust-resistant anti-rust coating, which is similar to Example 1, except that sodium dodecylbenzenesulfonate in the emulsifier is replaced with an equal mass of isopropyl alcohol, i.e., the amount of isopropyl alcohol is 4.5 parts. The remaining components and amounts are the same as in Example 1 and are not further described.

[0149] The preparation method of the rust-proof coating is similar to that of Example 1, except that step S300 is omitted and the addition of sodium dodecylbenzenesulfonate is omitted in S600. The remaining conditions are the same as those of Example 1 and will not be repeated here.

[0150] Example 8 This example provides a rust-resistant coating similar to Example 1, differing only in that the rust-removing agent comprises equal amounts of an aminocarboxylic acid chelating agent (EDTA), a hydroxycarboxylic acid chelating agent (gluconic acid), and a polycarboxylic acid chelating agent (polymaleic anhydride). The remaining components and their amounts are the same as those in Example 1 and are not further described.

[0151] The preparation method of the rust-proof coating is similar to that of Example 1, except that the addition of the sulfur-containing organic chelating agent is omitted in S500. The remaining conditions are the same as those of Example 1 and will not be repeated here.

[0152] Example 9 This example provides a rust-resistant coating similar to Example 1, differing only in that the rust-removing agent comprises equal amounts of an aminocarboxylic acid chelating agent (EDTA), a hydroxycarboxylic acid chelating agent (gluconic acid), and a sulfur-containing organic chelating agent (thioglycolic acid). The remaining components and their amounts are the same as those in Example 1 and are not further described.

[0153] The preparation method of the rust-proof coating is similar to that of Example 1, except that the addition of the polycarboxylic acid chelating agent is omitted in S500. The remaining conditions are the same as those of Example 1 and are not described in detail.

[0154] Example 10 This example provides a rust-resistant coating similar to Example 1, differing only in that the silicate (sodium metasilicate) in the high-efficiency corrosion inhibitor is replaced with an equivalent mass of zinc salt (zinc oleate). Specifically, the high-efficiency corrosion inhibitor comprises molybdate (sodium molybdate) and zinc salt (zinc oleate) in a mass ratio of 6:4. The remaining components and their contents are the same as in Example 1 and are not further described.

[0155] The preparation method of the rust-proof coating is similar to that of Example 1, except that the addition of silicate is omitted in S400. The remaining conditions are the same as those of Example 1 and are not described in detail.

[0156] Example 11 This embodiment provides a rust-resistant coating similar to that of Example 1, except that the zinc salt (zinc oleate) in the high-efficiency corrosion inhibitor is replaced with an equivalent mass of chromate (sodium chromate). The remaining components and contents are the same as those of Example 1 and are not further described.

[0157] The preparation method of the rust-resistant coating is similar to that of Example 1, except that in S400, molybdate, silicate, and chromate are dissolved in water to form a 22 wt% high-efficiency corrosion inhibitor. The remaining conditions are the same as those of Example 1 and are not further described.

[0158] Comparative Example 1 This comparative example provides a rust-proof coating similar to Example 1, except that the soybean oil fatty acid used as the raw material for the alkyd resin is replaced with an equal mass of dimer acid. The remaining components and contents are the same as those in Example 1 and are not described in detail.

[0159] The preparation method of the above-mentioned rust-proof coating comprises the following steps: S100, preparation of alkyd resin: Weigh all raw materials according to the designed ratio, add polyol, phthalic anhydride, terephthalic acid and dimer acid into the reactor, stir and melt at 130℃; Then, p-toluenesulfonic acid was added, and the temperature was raised to 190°C at a rate of 8°C / min to carry out low-temperature polymerization reaction, and the temperature was kept for 3.5 hours, during which the acid value of the reaction system was monitored in real time; When the acid value of the reaction system dropped to 25 mgKOH / g, the temperature was raised to 225°C for high-temperature polymerization. When the acid value of the reaction system dropped to 10 mgKOH / g, the temperature was lowered to 110°C, 1000# solvent oil was added for swelling, and the stirring time was 35 minutes. The temperature was continued to drop to 85°C, and after the viscosity of the liquid system was controlled to be 40s (25°C), the mixture was filtered while hot, cooled to room temperature, and the solid content was tested and fine-tuned to obtain the alkyd resin.

[0160] S200 to S600 are the same as S200 to S600 in Example 1 and will not be described in detail.

[0161] Comparative Example 2 This comparative example provides a rust-resistant anti-rust coating similar to Example 1, differing only in that terephthalic acid, the raw material for the alkyd resin, is replaced with an equivalent mass of isophthalic acid, and 1000# solvent naphtha (the raw material for the alkyd resin) is replaced with xylene. The remaining components and their contents are the same as those in Example 1 and are not further described.

[0162] The preparation method of the above-mentioned rust-proof coating comprises the following steps: S100, preparation of alkyd resin: Weigh all raw materials according to the designed ratio, add polyol, phthalic anhydride, isophthalic acid and soybean oil fatty acid into the reactor, stir and melt at 130℃; Then, p-toluenesulfonic acid was added, and the temperature was raised to 190°C at a rate of 8°C / min to carry out low-temperature polymerization reaction, and the temperature was kept for 3.5 hours, during which the acid value of the reaction system was monitored in real time; When the acid value of the reaction system dropped to 25 mgKOH / g, the temperature was raised to 225°C for high-temperature polymerization. When the acid value of the reaction system dropped below 15 mgKOH / g, the temperature was lowered to 110°C, and xylene was added for swelling. The stirring time was 35 minutes. The temperature was continued to drop to 85°C, and after the viscosity of the liquid system was controlled to be 42s (25°C), the mixture was filtered while hot, cooled to room temperature, and the solid content was tested and fine-tuned to obtain the alkyd resin.

[0163] S200 to S600 are the same as S200 to S600 in Example 1 and will not be described in detail.

[0164] Comparative Example 3 This comparative example provides a rust-resistant coating, which is similar to Example 1, except that the coumarone resin is replaced with an alkyd resin of equal mass, i.e., the amount of alkyd resin is 48 parts. The remaining components and contents are the same as those in Example 1 and are not further described.

[0165] The preparation method of the rust-proof coating is similar to that of Example 1, except that the addition of coumarone resin is omitted in S200. The remaining conditions are the same as those of Example 1 and are not described in detail.

[0166] Comparative Example 4 This comparative example provides a rust-resistant coating similar to Example 1, except that the polyether polyurethane resin is replaced with an alkyd resin of equal mass, i.e., the amount of alkyd resin is 37 parts. The remaining components and amounts are the same as those in Example 1 and are not further described.

[0167] The preparation method of the rust-proof coating is similar to that of Example 1, except that the addition of the polyether polyurethane resin is omitted in S200. The remaining conditions are the same as those of Example 1 and are not described in detail.

[0168] Comparative Example 5 This comparative example provides a rust-resistant anti-rust coating similar to Example 1, except that the coumarone resin and polyether polyurethane resin are replaced with an alkyd resin of equal mass, i.e., the amount of alkyd resin is 55 parts. The remaining components and amounts are the same as those in Example 1 and are not further described.

[0169] The preparation method of the rust-proof coating is similar to that of Example 1, except that the addition of coumarone resin and polyether polyurethane resin is omitted in S200. The remaining conditions are the same as those of Example 1 and are not described in detail.

[0170] Comparative Example 6 This comparative example provides a rust-resistant anti-rust coating similar to Example 1, except that the composite modified resin is replaced with a mixture of equal masses of alkyd resin, coumarone resin, and polyether polyurethane resin. Specifically, the resin matrix is ​​a mixture of 30 parts alkyd resin, 18 parts coumarone resin, and 7 parts polyether polyurethane resin. The remaining components and their amounts are the same as those in Example 1 and are not further described.

[0171] The preparation method of the above-mentioned rust-resistant anti-rust coating is similar to that of Example 1, except that in S200, alkyd resin, coumarone resin, and polyether polyurethane resin are melted at 110° C. and used as the resin matrix instead of the composite modified resin. The remaining conditions are the same as those of Example 1 and are not further described.

[0172] Comparative Example 7 This comparative example provides a rust-resistant anti-rust coating similar to Example 1, except that the alkyd resin is replaced with an equivalent mass of alkyd resin HC 389-8, i.e., the alkyd resin has a solids content of 55%, a tack viscosity of 25s, an acid value of ≤15 mgKOH / g, and 200# solvent naphtha is used as the solvent. The remaining components and their contents are the same as those in Example 1 and are not further described.

[0173] The method for preparing the rust-proof coating is similar to that of Example 1, except that step S100 is omitted. The remaining conditions are the same as those of Example 1 and are not described in detail.

[0174] Verification test The performance test of the rust-proof coatings provided in Examples 1 to 11 and Comparative Examples 1 to 7 is shown in Tables 1 and 2. The metal substrate is a rusty tinplate, and the coating amount is 150 g / m 2 , a single coat is sufficient; no excessive surface preparation is required on the test specimens, just remove the loose rust.

[0175] Table 1 Performance test results of rust-proof coatings 1

[0176] Table 2 Performance test results of rust-proof coatings

[0177] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions or improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A rust-proof paint, characterized in that: The invention comprises the following raw materials in parts by weight: 50 to 60 parts of composite modified resin, 2 to 6 parts of emulsifier, 30 to 35 parts of filler, 20 to 25 parts of anti-rust pigment and 3 to 5 parts of rust-removing agent; The composite modified resin is prepared by modifying alkyd resin, coumarone resin and polyether polyurethane resin with maleic anhydride; the alkyd resin comprises the following raw materials: polyol, phthalic anhydride, terephthalic acid, soybean oil fatty acid and high flash point aromatic hydrocarbon solvent.

2. The rust-proof paint according to claim 1, characterized in that: The alkyd resin comprises the following raw materials in percentage by weight: 11% to 15% of polyol, 16% to 19% of phthalic anhydride, 2% to 4% of terephthalic acid, 45% to 55% of soybean oil fatty acid, 0.1% to 0.2% of catalyst and 14% to 20% of high flash point aromatic hydrocarbon solvent; The composite modified resin comprises the following raw materials in parts by mass: 28 to 32 parts of alkyd resin, 16 to 20 parts of coumarone resin, 5 to 8 parts of polyether polyurethane resin and 0.4 to 0.8 parts of maleic anhydride.

3. The rust-proofing paint according to claim 1 or 2, characterized in that: The molar ratio of hydroxyl group to carboxyl group in the raw material of the alkyd resin is (1.1-1.2):1; The polyol comprises glycerol, trimethylolpropane, sorbitol and castor oil in a mass ratio of (4-5):(3-4):(1-2):

1.

4. The rust-proofing paint according to claim 1 or 2, characterized in that: The alkyd resin has a solid content of 68% to 72%, a format viscosity of 20s to 30s, an acid value of ≤15mgKOH / g, and a closed cup flash point of >60°C; The softening point of the coumarone resin is 70°C to 80°C; The softening point of the polyether polyurethane resin is 80°C to 100°C; The density of the rust-removing agent is 1.05 g / cm 3 ~1.15g / cm 3 , format viscosity is 10s~20s.

5. The rust-proofing paint according to claim 1 or 2, characterized in that: The emulsifier includes isopropyl alcohol and sodium C12~C18 alkylbenzene sulfonate; The filler includes organic bentonite and nano-ultrafine barium sulfate; The anti-rust pigment includes an inorganic pigment and a high-efficiency corrosion inhibitor; The rust-reducing agent includes aminocarboxylic acid chelating agent, hydroxycarboxylic acid chelating agent, sulfur-containing organic chelating agent and polycarboxylic acid chelating agent.

6. The rust-proofing paint according to claim 5, characterized in that: The inorganic pigment includes at least one of red iron oxide or iron titanium powder; The high-efficiency corrosion inhibitor comprises molybdate, zinc salt and silicate in a mass ratio of (5-8):(2-3):(1-2); The mass ratio of the aminocarboxylic acid chelating agent, the hydroxycarboxylic acid chelating agent, the sulfur-containing organic chelating agent and the polycarboxylic acid chelating agent is (3-5):(2-3.5):(1-2):

1.

7. The rust-proof paint according to claim 6, characterized in that: The molybdate includes at least one of sodium molybdate or ammonium molybdate; The zinc salt includes zinc oleate; The silicate comprises at least one of sodium metasilicate or potassium water glass; The aminocarboxylic acid chelating agent includes at least one of ethylenediaminetetraacetic acid or hydroxyethylethylenediaminetriacetic acid; The hydroxycarboxylic acid chelating agent includes at least one of gluconic acid or citric acid; The sulfur-containing organic chelating agent includes thioglycolic acid; The polycarboxylic acid chelating agent includes polymaleic anhydride.

8. The rust-proof paint according to claim 5, characterized in that: The preparation method of the alkyd resin comprises the following steps: Add polyol, phthalic anhydride, terephthalic acid and soybean oil fatty acid into a reactor, stir and melt, add a catalyst, and carry out a low-temperature polymerization reaction at 180°C to 200°C. When the acid value of the reaction system drops to 20mgKOH / g to 30mgKOH / g, raise the temperature to 220°C to 230°C for a high-temperature polymerization reaction. When the acid value of the reaction system drops below 15mgKOH / g, cool it to 100°C to 120°C, add a high-flash-point aromatic hydrocarbon solvent for swelling, and obtain an alkyd resin. The preparation method of the high-efficiency corrosion inhibitor comprises the following steps: Dissolving molybdate and silicate in water to form an inorganic salt aqueous solution; adding zinc salt to a high flash point aromatic hydrocarbon solvent to form a zinc salt solution; adding the inorganic salt aqueous solution to the zinc salt solution to obtain a high-efficiency corrosion inhibitor; The preparation method of the rust-removing agent comprises the following steps: Dissolve the aminocarboxylic acid chelating agent and the hydroxycarboxylic acid chelating agent in water, adjust the pH value of the liquid system to 2-2.5, add the sulfur-containing organic chelating agent, the polycarboxylic acid chelating agent and the film-forming aid in sequence at 30-40°C, adjust the pH value of the liquid system to 2.5-3, and obtain the rust-removing agent.

9. The rust-proofing paint according to claim 5, characterized in that: The rust-proof paint comprises the following raw materials in parts by mass: 28 to 32 parts of alkyd resin, 16 to 20 parts of coumarone resin, 5 to 8 parts of polyether polyurethane resin, 0.4 to 0.8 parts of maleic anhydride, 2 to 5 parts of isopropyl alcohol, 0.1 to 1 part of C12 to C18 sodium alkylbenzene sulfonate, 5 to 10 parts of high flash point aromatic hydrocarbon solvent, 1 to 2 parts of organic bentonite, 28 to 33 parts of nano-ultrafine barium sulfate, 1 to 2 parts of adhesion promoter, 0.3 to 1 part of dispersant, 0.1 to 0.5 parts of defoaming agent, 5 to 10 parts of high-efficiency corrosion inhibitor, 13 to 17 parts of inorganic pigment, 0.1 to 1 part of metal drying agent and 3 to 5 parts of rust removal agent.

10. The method for preparing the rust-proof and anti-rust coating according to any one of claims 1 to 9, characterized in that: The steps include: The composite modified resin and the emulsifier are mixed, and a high flash point aromatic hydrocarbon solvent, a filler, an anti-rust pigment and an additive are added, and the mixture is ground to obtain a paint slurry; Add a metal drying agent and a rust-removing agent into the paint slurry, mix them evenly, and obtain a rust-proof and anti-rust paint.

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