Deicing high-weather-resistant coating for color-coated sheet and preparation method of deicing high-weather-resistant coating

Abstract

The invention discloses a deicing high-weather-resistant coating for a color-coated sheet and a preparation method of the deicing high-weather-resistant coating, and belongs to the technical field of coatings, the coating comprises the following raw material components in parts by weight: 30-50 parts of organic silicon resin, 26-40 parts of high-weather-resistant inorganic pigment filler, 1-4 parts of magnetic and photo-thermal nanoparticles, 2-8 parts of an auxiliary agent, 10-20 parts of a solvent and 3-16 parts of a curing agent. Wherein the organic silicon resin is prepared by carrying out esterification polycondensation reaction on polyhydric alcohol, polybasic acid and an organic silicon monomer in the presence of a catalyst and an antioxidant. According to the coating system, the low surface energy of the organic silicon resin and the photothermal conversion effect of the magnetism and the photothermal type nanoparticles are utilized to achieve the synergistic effect, and the adhesive force of an ice layer can be remarkably reduced. Laboratory tests show that the deicing area ratio of a coating formed by the paint can reach 95% or above, the paint has excellent weather resistance, mechanical strength and adhesive force, long-acting protection can be provided for a color-coated sheet in a severe environment, and the service life of the color-coated sheet is remarkably prolonged.

Description

Technical Field

[0001] This invention relates to the field of coating technology, specifically to a de-icing and high weather-resistant coating for color-coated steel sheets and its preparation method. Background Technology

[0002] Color-coated steel sheets, widely used in construction, home appliances, and decoration, boast advantages such as lightweight, high strength, and vibrant colors. However, in cold regions or low-temperature winter environments, the surface of color-coated steel sheets is prone to icing, causing a series of problems. In terms of performance, ice buildup affects both the aesthetics and the insulation and waterproofing properties. Regarding safety, for example, icing on color-coated steel sheets used in building roofs increases the load and may lead to structural safety issues; icing on the surface of color-coated steel sheets in industrial plants may affect temperature control and increase energy consumption. In terms of maintenance, traditional de-icing methods (such as manual removal) are inefficient and easily damage the surface coating, while the use of chemical de-icing agents may corrode the sheets, accelerating their aging, and the residue of these chemicals can also pollute the environment.

[0003] Currently, coating technologies for de-icing precast steel sheets have the following limitations: Poor de-icing effect; some coatings cannot effectively reduce the adhesion between ice and the precast steel sheet surface, making efficient de-icing difficult. Insufficient weather resistance; most coatings degrade rapidly in performance (such as de-icing properties and adhesion) after long-term exposure to complex climatic conditions such as ultraviolet radiation, drastic temperature changes, and rain and snow erosion, failing to provide sustained good de-icing and protective functions for precast steel sheets. Poor adhesion between existing coatings and the precast steel sheet substrate or coating layer, potentially affecting long-term stability and ease of application.

[0004] Therefore, developing a high-efficiency de-icing and highly weather-resistant coating specifically for color-coated steel sheets is of great practical significance. Summary of the Invention

[0005] Therefore, this invention provides a de-icing, high-weather-resistant coating for color-coated steel sheets and its preparation method, to overcome the shortcomings of existing technologies. This coating can significantly reduce the adhesion of ice to the surface of color-coated steel sheets, achieving efficient de-icing, while also possessing excellent weather resistance, providing long-term stable protection for color-coated steel sheets in complex and harsh environments, thus extending their service life.

[0006] To achieve the above objectives, the present invention provides the following technical solution: According to a first aspect of the present invention, a de-icing and high weather-resistant coating for color-coated steel sheets is provided, comprising the following raw material components in parts by weight: Organosilicon resin: 30-50 parts; High weather-resistant inorganic pigments and fillers: 26-40 parts; Magnetic and photothermal nanoparticles: 1-4 parts; Additives: 2-8 parts; Solvent: 10-20 parts; Hardener: 3-16 parts.

[0007] Furthermore, the silicone resin comprises the following raw material components in parts by weight: Polyols: 20-30 parts; Polybasic acids: 20-30 parts; Organosilicon monomer: 10-20 parts; Catalyst: 0.1-0.2 parts; Antioxidant: 0.1-0.2 parts.

[0008] Furthermore, the high weather-resistant inorganic pigments and fillers are selected from at least one of coated titanium dioxide, ceramic pigments, and precipitated barium sulfate; the magnetic and photothermal nanoparticles are selected from at least one of iron(III) oxide (Fe3O4) nanoparticles, semiconductor nanoparticles doped with magnetic elements (such as Fe, Co, Ni, etc.) (such as TiO2, ZnO), and γ-Fe2O3@carbon-based materials, wherein the carbon-based materials include, but are not limited to, graphene and carbon nanotubes; the additives are selected from at least one of dispersants, polyester leveling agents, defoamers, catalysts, anti-settling agents, antioxidants, and ultraviolet light absorbers; the solvent is selected from at least one of solvent oil 100#, ethylene glycol butyl ether, propylene glycol methyl ether acetate, and DBE; the curing agent is selected from at least one of all-methyl ether amino resins, partially methyl etherified amino resins (such as hemimethyl etherified amino resins), and blocked HDI curing agents (such as HDI blocked polyurethane resins).

[0009] Further, the polyol is selected from at least one of neopentyl glycol, methyl propylene glycol, trimethylolpropane, and 1,6-hexanediol; the polyacid is selected from at least one of terephthalic acid, phthalic anhydride, isophthalic acid, adipic acid, and trimellitic anhydride; the organosilicon monomer is selected from at least one of methyltrimethoxysilane, diphenyldimethoxysilane, and hydroxyl-terminated polydimethylsiloxane; the antioxidant is at least one of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010) and tris(2,4-di-tert-butylphenyl) phosphite (antioxidant 168); the catalyst is selected from at least one of dibutyltin oxide, monobutyltin oxide, and tetraisopropyl titanate. According to a second aspect of the present invention, a method for preparing a de-icing and high weather-resistant coating for color-coated steel sheets is provided, comprising the following steps: S1. Preparation of organosilicon resin; S2. Preparation of organosilicon color paste; S3. Preparation of organosilicon coatings; S4, pre-dispersed magnetic and photothermal nanoparticles; S5. Mix the organosilicon coating with pre-dispersed magnetic and photothermal nanoparticles to prepare a de-icing and high weather-resistant coating for color-coated steel sheets.

[0010] Furthermore, in step S5, the mass ratio of the organosilicon coating to the pre-dispersed magnetic and photothermal nanoparticles is 30:1.

[0011] Furthermore, the pre-dispersion of magnetic and photothermal nanoparticles in step S4 is carried out in the following specific steps: Solvent and magnetic and photothermal nanoparticles were mixed at a mass ratio of 2:1. The magnetic and photothermal nanoparticles were dispersed using ultrasound and reacted for 30 minutes to obtain a pre-dispersed nanoslurry. The obtained pre-dispersed nanoslurry was then mixed with organosilicon resin at a mass ratio of 1:10 and added to a disperser. The system was dispersed uniformly at a dispersion speed of 700 r / min to ensure a fineness ≤15 μm, thus obtaining pre-dispersed magnetic and photothermal nanoparticles.

[0012] Furthermore, the preparation process of the organosilicon resin in step S1 is as follows: Polyols, polyacids, organosilicon monomers, and antioxidants are added to a reactor in a specific ratio, and nitrogen is introduced to replace the reaction system. When the temperature rises to 230℃, a catalyst is added, and the system is kept at atmospheric pressure for 2-4 hours to carry out a dehydration reaction until the acid value drops to 50-100 mg KOH / g. The system pressure is then reduced to 100-500 Pa, and the temperature is kept constant for 3-6 hours to continue the reaction until the acid value is <10 mg KOH / g and the viscosity reaches 35-45 s (25℃, Giethoorn tube), thus obtaining the organosilicon resin.

[0013] Furthermore, the preparation process of the organosilicon color paste in step S2 is as follows: Add the silicone resin and solvent to the mixing tank in proportion, stir at 700 r / min and slowly add the additives, stir for 8-12 min until completely dissolved; add the high weather-resistant inorganic pigments and fillers in 2-3 batches, stirring at 700 r / min until initially wetted; after the materials are mixed evenly and there are no abnormal lumps on the tank wall, adjust the speed to 1500 r / min and continue to disperse for 30 min until evenly dispersed to obtain a pre-dispersed slurry; transfer the obtained pre-dispersed slurry to a sand mill and grind to a fineness ≤10μm to obtain silicone pigment paste.

[0014] Furthermore, the preparation process of the organosilicon coating in step S3 is as follows: Premixing stage: Add part of the silicone resin and part of the solvent to the mixing tank in sequence, and stir at 500-800 r / min for 5-10 min until the mixture is uniform; keep the speed constant and continue stirring, and add dispersant, anti-settling agent and high weather-resistant inorganic pigments and fillers in sequence, and stir at 1000 r / min for 60 min to obtain pre-dispersed slurry; Grinding stage: The pre-dispersed slurry obtained above is transferred to a sand mill for grinding until the fineness is <10μm to obtain a grinding slurry; Mixing and preparing the paint: Add the silicone color paste and the remaining silicone resin to a mixing tank containing the grinding slurry, and stir at 500-800 r / min for 5-10 min until the mixture is uniform; add the curing agent, polyester leveling agent, defoamer, catalyst, antioxidant, ultraviolet light absorber and the remaining solvent in sequence, and continue stirring at the same speed for 30 min until the mixture is uniform to obtain the silicone coating.

[0015] The present invention has the following advantages: The de-icing and high weather-resistant coating for color-coated steel sheets provided by this invention, based on the synergistic effect of organosilicon resin and magnetic and photothermal nanoparticles, has the following characteristics: (1) Low-temperature self-de-icing performance; The coating system combines the low surface energy of silicone resin with the photothermal conversion effect of magnetic and photothermal nanoparticles, significantly reducing the adhesion strength of ice crystals and achieving efficient de-icing. Laboratory simulation tests show that under natural temperature fluctuations or slight external forces, ice can detach from the coating surface over a large area, with a de-icing area ratio exceeding 95%. This effectively solves the problem of strong ice adhesion and difficulty in removal from the surface of color-coated steel sheets.

[0016] (2) Long-term protection system; The synergistic effect of silicone resin and magnetic and photothermal nanoparticles endows the coating with excellent weather resistance. The silicone resin forms a dense cross-linked network structure, providing the coating system with fundamental weather resistance and mechanical strength, effectively resisting ultraviolet radiation and chemical corrosion, and improving the coating's impact resistance, abrasion resistance, and scratch resistance. Simultaneously, the introduced magnetic and photothermal nanoparticles further enhance functionality: on the one hand, they can efficiently scatter and absorb ultraviolet radiation, compensating for the resin's protective shortcomings; on the other hand, they generate micro-heat under light through photothermal conversion, inhibiting surface moisture condensation and microbial adhesion, achieving active protection. This synergistic effect allows the coating to maintain stable performance under harsh environments, thereby significantly extending the service life of the color-coated steel sheet. After 3000h QUV accelerated aging and 2000h neutral salt spray testing, the coatings formed by the de-icing high-weather-resistant coatings for color-coated steel sheets of this invention (Examples 1-3) showed no cracking or peeling. Their impact strength (9J) was significantly increased by approximately 28.6% compared to traditional coatings (7J), demonstrating superior weather resistance and mechanical properties. Detailed Implementation

[0017] The following specific embodiments illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] According to a first aspect of the present invention, a de-icing and high weather-resistant coating for color-coated steel sheets is provided, comprising the following raw material components in parts by weight: Organosilicon resin: 30-50 parts; High weather-resistant inorganic pigments and fillers: 26-40 parts; Magnetic and photothermal nanoparticles: 1-4 parts; Additives: 2-8 parts; Solvent: 10-20 parts; Hardener: 3-16 parts.

[0019] Furthermore, the silicone resin comprises the following raw material components in parts by weight: Polyols: 20-30 parts; Polybasic acids: 20-30 parts; Organosilicon monomer: 10-20 parts; Catalyst: 0.1-0.2 parts; Antioxidant: 0.1-0.2 parts.

[0020] Furthermore, the high weather-resistant inorganic pigments and fillers are selected from at least one of coated titanium dioxide, ceramic pigments, and precipitated barium sulfate; the magnetic and photothermal nanoparticles are selected from at least one of iron(III) oxide (Fe3O4) nanoparticles, semiconductor nanoparticles doped with magnetic elements (such as Fe, Co, Ni, etc.) (such as TiO2, ZnO) nanoparticles, and γ-Fe2O3@carbon-based materials, the carbon-based materials including but not limited to graphene and carbon nanotubes; the additives are selected from at least one of dispersants, polyester leveling agents, defoamers, catalysts, anti-settling agents, antioxidants, and ultraviolet light absorbers; the solvents are selected from at least one of solvent oil 100#, ethylene glycol butyl ether, propylene glycol methyl ether acetate, and DBE; the curing agent is selected from at least one of all-methyl ether amino resins, partially methyl etherified amino resins (such as hemimethyl etherified amino resins, etc.), and blocked HDI curing agents (such as HDI blocked polyurethane resins, etc.).

[0021] Furthermore, the polyol is selected from at least one of neopentyl glycol, methyl propylene glycol, trimethylolpropane, and 1,6-hexanediol; the polyacid is selected from at least one of terephthalic acid, phthalic anhydride, isophthalic acid, adipic acid, and trimellitic anhydride; the organosilicon monomer is selected from at least one of methyltrimethoxysilane, diphenyldimethoxysilane, and hydroxyl-terminated polydimethylsiloxane; the antioxidant is at least one of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] (antioxidant 1010) and tris(2,4-di-tert-butylphenyl) phosphite (antioxidant 168); and the catalyst is selected from at least one of dibutyltin oxide, monobutyltin oxide, and tetraisopropyl titanate.

[0022] According to a second aspect of the present invention, a method for preparing a de-icing and high weather-resistant coating for color-coated steel sheets is provided, comprising the following steps: S1. Preparation of organosilicon resin; S2. Preparation of organosilicon color paste; S3. Preparation of organosilicon coatings; S4, pre-dispersed magnetic and photothermal nanoparticles; S5. Mix the organosilicon coating with pre-dispersed magnetic and photothermal nanoparticles to prepare a de-icing and high weather-resistant coating for color-coated steel sheets.

[0023] Furthermore, in step S5, the mass ratio of the organosilicon coating to the pre-dispersed magnetic and photothermal nanoparticles is 30:1.

[0024] Furthermore, the pre-dispersion of magnetic and photothermal nanoparticles in step S4 is carried out in the following specific steps: Solvent and magnetic and photothermal nanoparticles were mixed at a mass ratio of 2:1. The magnetic and photothermal nanoparticles were dispersed using ultrasound and reacted for 30 minutes to obtain a pre-dispersed nanoslurry. The obtained pre-dispersed nanoslurry was then mixed with organosilicon resin at a mass ratio of 1:10 and added to a disperser. The system was dispersed uniformly at a dispersion speed of 700 r / min to ensure a fineness ≤15 μm, thus obtaining pre-dispersed magnetic and photothermal nanoparticles.

[0025] Furthermore, the preparation process of the organosilicon resin in step S1 is as follows: Polyols, polyacids, organosilicon monomers, and antioxidants are added to a reactor in a specific ratio, and nitrogen is introduced to replace the reaction system. When the temperature rises to 230℃, a catalyst is added, and the system is kept at atmospheric pressure for 2-4 hours to carry out a dehydration reaction until the acid value drops to 50-100 mg KOH / g. The system pressure is then reduced to 100-500 Pa, and the temperature is kept constant for 3-6 hours to continue the reaction until the acid value is <10 mg KOH / g and the viscosity reaches 35-45 s (25℃, Giethoorn tube), thus obtaining the organosilicon resin.

[0026] Furthermore, the preparation process of the organosilicon color paste in step S2 is as follows: Add the silicone resin and solvent to the mixing tank in proportion, stir at 700 r / min and slowly add the additives, stir for 8-12 min until completely dissolved; add the high weather-resistant inorganic pigments and fillers in 2-3 batches, stirring at 700 r / min until initially wetted; after the materials are mixed evenly and there are no abnormal lumps on the tank wall, adjust the speed to 1500 r / min and continue to disperse for 30 min until evenly dispersed to obtain a pre-dispersed slurry; transfer the obtained pre-dispersed slurry to a sand mill and grind to a fineness ≤10μm to obtain silicone pigment paste.

[0027] Furthermore, the preparation process of the organosilicon coating in step S3 is as follows: Premixing stage: Add part of the silicone resin and part of the solvent to the mixing tank in sequence, and stir at 500-800 r / min for 5-10 min until the mixture is uniform; keep the speed constant and continue stirring, and add dispersant, anti-settling agent and high weather-resistant inorganic pigments and fillers in sequence, and stir at 1000 r / min for 60 min to obtain pre-dispersed slurry; Grinding stage: The pre-dispersed slurry obtained above is transferred to a sand mill for grinding until the fineness is <10μm to obtain a grinding slurry; Mixing and preparing the paint: Add the silicone color paste and the remaining silicone resin to a mixing tank containing the grinding slurry, and stir at 500-800 r / min for 5-10 min until the mixture is uniform; add the curing agent, polyester leveling agent, defoamer, catalyst, antioxidant, ultraviolet light absorber and the remaining solvent in sequence, and continue stirring at the same speed for 30 min until the mixture is uniform to obtain the silicone coating.

[0028] Preparation Example 1: Preparation of organosilicon resin: 25g of methylpropylene glycol, 25g of terephthalic acid, 15g of methyltrimethoxysilane, and 0.1g of antioxidant 1010 were added to a reactor, and nitrogen gas was introduced to replace the reaction system. When the temperature reached 230℃, 0.1g of catalyst was added, and the system was kept at atmospheric pressure for 4 hours to carry out the dehydration reaction until the acid value dropped to 80mg KOH / g. The system pressure was reduced to 300Pa, the temperature was kept constant, and the reaction was continued for 5 hours until the acid value reached 8mg KOH / g and the viscosity reached 40s (25℃, Giethoornis tube), thus obtaining the organosilicon resin. Example 1

[0029] A method for preparing a de-icing and high weather-resistant coating for color-coated steel sheets: (1) Preparation of organosilicon pigments: 12g of the silicone resin from Preparation Example 1 and 2g of solvent (prepared by mixing 1g solvent oil 100#, 0.2g ethylene glycol butyl ether, 0.6g propylene glycol methyl ether acetate, and 0.2g DBE) were added to a stirred tank and stirred at 700r / min. Then, 1.5g of additives (composed of 0.25g dispersant KMT-J3003, 0.5g polyester leveling agent Anjeka 7380, 0.1g polyether-modified silicone defoamer B-0518, 0.25g dodecylbenzene sulfonic acid, and 0.2g fumed silica Aerosil) were slowly added. The mixture was prepared by mixing 200g of antioxidant 1010 and 0.1g of UV absorber UV928 and stirring for 10 minutes until completely dissolved. 24g of precipitated barium sulfate was added in three portions, maintaining a speed of 700r / min until initially wetted. After the material was evenly mixed and there were no abnormal lumps on the cylinder wall, the speed was adjusted to 1500r / min and dispersion was continued for 30 minutes until evenly dispersed to obtain a pre-dispersed slurry. The obtained pre-dispersed slurry was transferred to a sand mill and ground to a fineness of <10μm to obtain an organosilicon color paste.

[0030] (2) Preparation of organosilicon coatings: 10g of the silicone resin from Preparation Example 1 and 5g of solvent (prepared by mixing 2.5g of solvent oil 100#, 0.5g of ethylene glycol butyl ether, 1.5g of propylene glycol methyl ether acetate and 0.5g of DBE) were added to a mixing vessel and stirred at 800r / min for 8min until homogeneous. The stirring speed was kept constant and 0.25g of dispersant KMT-J3003, 0.2g of fumed silica Aerosil 200 and 8g of precipitated barium sulfate were added sequentially. The mixture was stirred at 1000r / min for 60min to obtain a pre-dispersed slurry. The pre-dispersed slurry was transferred to a sand mill for grinding until the fineness was <10μm to obtain a ground slurry. All the silicone pigment obtained in step (1) and 5g of the silicone resin from Preparation Example 1 were added to the mixing vessel containing the ground slurry and stirred at 500-800r / min for 5-10min until homogeneous. 6g of the solvent was added sequentially. The following ingredients were added: a curing agent (prepared by mixing 4g of all-methyl ether amino resin and 2g of hemimethyl ether amino resin), 0.5g of polyester leveling agent Anjeka7380, 0.1g of polyether modified silicone defoamer B-0518, 0.25g of dodecylbenzene sulfonic acid, 0.1g of antioxidant 1010, 0.1g of ultraviolet absorber UV928, and 1g of solvent (prepared by mixing 0.5g of solvent oil 100#, 0.1g of ethylene glycol butyl ether, 0.3g of propylene glycol methyl ether acetate, and 0.1g of DBE). The mixture was stirred for 30 minutes at a constant speed until it was uniformly mixed to obtain the silicone coating.

[0031] (3) Preparation of pre-dispersed magnetic and photothermal nanoparticles: 8g of solvent (prepared by mixing 4g of solvent oil 100#, 0.8g of ethylene glycol butyl ether, 2.4g of propylene glycol methyl ether acetate and 0.8g of DBE) and 4g of γ-Fe2O3@graphene were mixed to obtain a mixture. The mixture was ultrasonically dispersed for 30min to obtain a pre-dispersed mixture. 2g of the obtained pre-dispersed mixture and 20g of the organosilicon resin from Preparation Example 1 were added to a disperser and dispersed at a speed of 700r / min to ensure uniform dispersion of the system and a fineness ≤15μm to obtain pre-dispersed γ-Fe2O3@graphene.

[0032] (4) Preparation of de-icing and high weather-resistant coating for color-coated steel sheets: Mix 30g of organosilicon coating from step (2) with 1g of pre-dispersed γ-Fe2O3@graphene from step (3) to obtain a de-icing and high weather-resistant coating for color-coated steel sheets. Example 2

[0033] A method for preparing a de-icing and high weather-resistant coating for color-coated steel sheets: (1) Preparation of organosilicon pigments: 10g of the silicone resin from Preparation Example 1 and 2g of solvent (prepared by mixing 1g solvent oil 100#, 0.2g ethylene glycol butyl ether, 0.6g propylene glycol methyl ether acetate, and 0.2g DBE) were added to a stirred tank and stirred at 700r / min. Then, 1.5g of additives (composed of 0.25g dispersant KMT-J3003, 0.5g polyester leveling agent Anjeka 7380, 0.1g polyether-modified silicone defoamer B-0518, 0.25g dodecylbenzene sulfonic acid, and 0.2g fumed silica Aerosil) were slowly added. The mixture was prepared by mixing 200g of antioxidant 1010 and 0.1g of UV absorber UV928 and stirring for 10 minutes until completely dissolved. 18g of precipitated barium sulfate was added in three portions, maintaining a speed of 700r / min until initially wetted. After the material was evenly mixed and there were no abnormal lumps on the cylinder wall, the speed was adjusted to 1500r / min and the mixture was continuously dispersed for 30 minutes until evenly dispersed to obtain a pre-dispersed slurry. The pre-dispersed slurry was transferred to a sand mill and ground to a fineness of <10μm to obtain an organosilicon color paste.

[0034] (2) Preparation of organosilicon coatings: Add 8g of the silicone resin from Preparation Example 1 and 5g of solvent (prepared by mixing 2.5g of solvent oil 100#, 0.5g of ethylene glycol butyl ether, 1.5g of propylene glycol methyl ether acetate, and 0.5g of DBE) sequentially to a mixing vessel and stir at 800 rpm for 8 minutes until homogeneous. Continue stirring while maintaining the same speed, and then add 0.25g of dispersant KMT-J3003 and 0.2g of fumed silica Aerosil sequentially. 200g and 2g of precipitated barium sulfate were stirred at 1000r / min for 60min to obtain a pre-dispersed slurry; the pre-dispersed slurry was transferred to a sand mill for grinding until the fineness was <10μm to obtain a ground slurry; all the organosilicon pigment obtained in step (1) and 2g of organosilicon resin from Preparation Example 1 were added to a mixing tank containing the ground slurry and stirred at 500-800r / min for 5-10min until the mixture was uniform; 5g of curing agent (composed of 3.75g of all-methyl ether amino resin and 1.25g of...) were added sequentially. The mixture consists of HDI-type blocked polyurethane resin, 0.5g polyester leveling agent Anjeka 7380, 0.1g polyether-modified silicone defoamer B-0518, 0.25g dodecylbenzene sulfonic acid, 0.1g antioxidant 1010, 0.1g UV absorber UV928, and 1g solvent (made from a mixture of 0.5g solvent oil 100#, 0.1g ethylene glycol butyl ether, 0.3g propylene glycol methyl ether acetate, and 0.1g DBE). Stirring is continued for 30 minutes at a constant speed until the mixture is homogeneous, yielding the silicone coating.

[0035] (3) Preparation of pre-dispersed magnetic and photothermal nanoparticles: 8g of solvent (prepared by mixing 4g of solvent oil 100#, 0.8g of ethylene glycol butyl ether, 2.4g of propylene glycol methyl ether acetate and 0.8g of DBE) and 4g of Fe-doped ZnO nanoparticles were mixed to obtain a mixture. The mixture was ultrasonically dispersed for 30min to obtain a pre-dispersed mixture. 2g of the obtained pre-dispersed mixture and 20g of the silicone resin from Preparation Example 1 were added to a disperser and dispersed at a speed of 700r / min to ensure uniform dispersion of the system and a fineness ≤15μm to obtain pre-dispersed Fe-doped ZnO nanoparticles.

[0036] (4) Preparation of de-icing and high weather-resistant coating for color-coated steel sheets: Mix 30g of organosilicon coating from step (2) with 1g of pre-dispersed Fe-doped ZnO nanoparticles from step (3) to obtain a de-icing and high weather-resistant coating for color-coated steel sheets. Example 3

[0037] A method for preparing a de-icing and high weather-resistant coating for color-coated steel sheets: (1) Preparation of organosilicon pigments: 7g of the silicone resin from Preparation Example 1 and 2g of solvent (prepared by mixing 1g solvent oil 100#, 0.2g ethylene glycol butyl ether, 0.6g propylene glycol methyl ether acetate, and 0.2g DBE) were added to a stirred tank and stirred at 700r / min. Then, 1.5g of additives (composed of 0.25g dispersant KMT-J3003, 0.5g polyester leveling agent Anjeka 7380, 0.1g polyether-modified silicone defoamer B-0518, 0.25g dodecylbenzene sulfonic acid, and 0.2g fumed silica Aerosil) were slowly added. The mixture of 200 g of barium sulfate, 0.1 g of antioxidant 1010, and 0.1 g of UV absorber UV928 was stirred for 10 min until completely dissolved. 25 g of precipitated barium sulfate was added in three portions, maintaining a speed of 700 r / min until initially wetted. After the material was evenly mixed and there were no abnormal lumps on the cylinder wall, the speed was adjusted to 1500 r / min and the mixture was continuously dispersed for 30 min until evenly dispersed to obtain a pre-dispersed slurry. The pre-dispersed slurry was transferred to a sand mill and ground to a fineness of <10 μm to obtain an organosilicon color paste.

[0038] (2) Preparation of organosilicon coatings: 7g of the silicone resin from Preparation Example 1 and 5g of solvent (prepared by mixing 2.5g of solvent oil 100#, 0.5g of ethylene glycol butyl ether, 1.5g of propylene glycol methyl ether acetate and 0.5g of DBE) were added to a mixing vessel in sequence and stirred at 800r / min for 8min until uniformly mixed. The stirring speed was kept constant and 0.25g of dispersant KMT-J3003, 0.2g of fumed silica Aerosil 200 and 2g of precipitated barium sulfate were added in sequence and stirred at 1000r / min for 60min to obtain a pre-dispersed slurry. The pre-dispersed slurry was transferred to a sand mill for grinding until the fineness was <10μm to obtain a ground slurry. All the silicone pigment obtained in step (1) and 1g of silicone resin from Preparation Example 1 were added to the mixing vessel containing the ground slurry and stirred at 500-800r / min for 5-10min until uniformly mixed. 6g of curing agent (prepared by mixing 4g of all-methyl ether amino resin and 2g of DBE) was added in sequence. The mixture consists of HDI-type blocked polyurethane resin, 0.5g polyester leveling agent Anjeka 7380, 0.1g polyether-modified silicone defoamer B-0518, 0.25g dodecylbenzene sulfonic acid, 0.1g antioxidant 1010, 0.1g UV absorber UV928, and 1g solvent (made from a mixture of 0.5g solvent oil 100#, 0.1g ethylene glycol butyl ether, 0.3g propylene glycol methyl ether acetate, and 0.1g DBE). Stirring is continued for 30 minutes at a constant speed until the mixture is homogeneous, yielding the silicone coating.

[0039] (3) Preparation of pre-dispersed magnetic and photothermal nanoparticles: 8g of solvent (prepared by mixing 4g of solvent oil 100#, 0.8g of ethylene glycol butyl ether, 2.4g of propylene glycol methyl ether acetate and 0.8g of DBE) and 4g of Fe3O4 nanoparticles were mixed to obtain a mixture. The mixture was ultrasonically dispersed for 30min to obtain a pre-dispersed mixture. 2g of the pre-dispersed mixture and 20g of the silicone resin from Preparation Example 1 were added to a disperser and dispersed at a speed of 700r / min to ensure uniform dispersion of the system and a fineness ≤15μm to obtain pre-dispersed Fe3O4 nanoparticles.

[0040] (4) Preparation of de-icing and high weather-resistant coating for color-coated steel sheets: Mix 30g of silicone coating from step (2) with 1g of pre-dispersed Fe3O4 nanoparticles from step (3) to obtain a de-icing and high weather-resistant coating for color-coated steel sheets.

[0041] Comparative example: A method for preparing traditional coatings for color-coated steel sheets: (1) Preparation of polyester pigment: Add 35g of SK9068 polyester resin and 15g of solvent oil 100# to a mixing tank and stir at 700r / min. Slowly add 0.25g of dispersant KMT-J3003, 0.5g of polyester leveling agent Anjeka7380, 0.1g of polyether modified silicone defoamer B-0518, 0.25g of dodecylbenzene sulfonic acid, and 0.2g of fumed silica Aerosil. 200 g of antioxidant 1010 and 0.1 g of UV absorber UV928 were stirred for 10 min until completely dissolved. 24 g of precipitated barium sulfate was added in 3 portions, maintaining a speed of 700 r / min until initially wetted. After the materials were mixed evenly and there were no abnormal lumps on the cylinder wall, the speed was adjusted to 1500 r / min and the mixture was continuously dispersed for 30 min until evenly dispersed to obtain a pre-dispersed slurry. The obtained pre-dispersed slurry was transferred to a sand mill and ground to a fineness of <10 μm to obtain polyester color paste.

[0042] (2) Preparation of predispersed graphene: 8g of solvent (prepared by mixing 4g of solvent oil 100#, 0.8g of ethylene glycol butyl ether, 2.4g of propylene glycol methyl ether acetate and 0.8g of DBE) and 4g of graphene were mixed to obtain a mixture. The mixture was ultrasonically dispersed for 30min to obtain a pre-dispersed mixture. 2g of the above pre-dispersed mixture and 20g of saturated polyester resin were added to a disperser and dispersed at a speed of 700r / min to ensure uniform dispersion of the system and a fineness ≤15μm to obtain pre-dispersed graphene.

[0043] (3) Preparation of traditional coatings for color-coated steel sheets: Mix 30g of polyester pigment from step (1), 1g of pre-dispersed graphene from step (2), and 8g of all-methyl ether amino resin evenly to obtain a traditional coating for color-coated steel sheets.

[0044] Test example: A systematic comparative test was conducted on the de-icing and high weather-resistant coatings for color-coated steel sheets prepared in Examples 1-3 and the conventional coatings for color-coated steel sheets prepared in the comparative examples. The specific methods are as follows: Sample preparation: The coatings in Examples 1-3 and the comparative examples were mixed with polyurethane white primer at a ratio of 1:1 to prepare the coatings to be tested.

[0045] Coating and Curing: The coating to be tested was uniformly applied to the surface of the galvanized steel substrate using a spraying process, and then cured under standard conditions. The following performance tests were performed on the fully cured coating samples: Bending performance: Tested in accordance with GB / T 6742-2007 "Bending test of paints and varnishes (cylindrical shaft)"; Pencil hardness: Tested according to GB / T 6739-2006 "Determination of Hardness of Coatings by Pencil Method for Paints and Varnishes"; Impact strength: Tested according to GB / T 1732-2020 "Determination of impact resistance of paints and varnishes"; Solvent resistance: The solvent resistance was tested by wiping with methyl ethyl ketone (MEK) in accordance with GB / T 23989-2009 "Determination of solvent resistance to wiping of paint and varnish coatings"; Artificial weathering resistance (QUV): The test duration is 3000h, and the test is carried out in accordance with GB / T 23987-2009 "Artificial weathering of paints and varnishes exposed to fluorescent ultraviolet lamps"; Resistance to neutral salt spray: The test duration is 2000h, and the test is conducted in accordance with GB / T 1771-2007 "Determination of resistance to neutral salt spray of paints and varnishes"; De-icing performance: The de-icing effect of the coating was evaluated using laboratory tests simulating outdoor icing conditions. The specific steps are as follows: Sample preparation: The fully cured coating sample (galvanized steel plate substrate) was cut into a standard template of 120mm × 60mm (length × width).

[0046] Artificial icing: Each set of samples was placed in a low-temperature environment of -10±2℃ for 3 hours. Then, deionized water was sprayed evenly on its surface to form a uniform ice layer with a thickness of about 2 mm, and it was frozen and fixed at -10℃ for 10 hours.

[0047] De-icing conditions: After being covered with ice, the standard sample was transferred to a programmable temperature-controlled environmental chamber and heated as follows: the temperature was increased from -6℃ to 4℃ at a rate of 0.5℃ / min to simulate the natural warming process during the day.

[0048] Effect evaluation: (1) De-icing area: Record the ratio of the de-icing area that naturally falls off during the heating process. The calculation formula is as follows: If the de-icing area ratio is ≥95%, it is considered to have excellent performance.

[0049] (2) Coating condition: Observe whether there are rust, blistering, cracking or paint peeling on the coating surface after de-icing, and observe whether there is a thin ice film attached to the surface.

[0050] The table below shows the performance test results of the polyurethane white primer used in Examples 1-3 and the comparative examples: Note: All the above tests were conducted under the same coating and curing process conditions (including board temperature, curing time, and coating thickness) to ensure the fairness and comparability of the test results.

[0051] As shown in the table above, the de-icing and high weather-resistant coatings for color-coated steel sheets based on the organosilicon resin system of this invention (Examples 1-3), when used with a polyurethane white primer, exhibit significantly better overall performance than traditional coatings based on the polyester resin system (comparative examples), as specifically demonstrated below: (1) Good mechanical properties: The coating combines excellent flexibility and impact resistance: it achieves the highest level (1T) in bending tests and an impact strength of 9J, which is 28.6% higher than the coating formed by traditional paints and polyurethane white primers for color-coated steel sheets (7J).

[0052] (2) High weather resistance: The coating demonstrated long-term durability in stringent accelerated aging tests: After 3000 hours of QUV accelerated aging, the coating showed discoloration and gloss loss levels of ≤2, chalking level of ≤1, and no rusting, blistering, cracking or peeling. After 2000 hours of neutral salt spray testing, the coating showed no discoloration or blistering levels of ≤2 (S3), and no abnormal phenomena such as rusting, cracking, or peeling.

[0053] (3) Excellent de-icing performance: In tests simulating outdoor icing conditions, the coating remained intact after de-icing. The de-icing area ratio reached over 95%, which is 10.5% higher than the coating formed by traditional paints with polyurethane white primer (86%) on color-coated steel sheets. Moreover, the surface was clean after the ice layer was removed, with no residual ice film, demonstrating highly efficient active de-icing capabilities.

[0054] (4) High overall stability: The coating exhibits excellent performance in key indicators such as solvent resistance (MEK wiping ≥100 times), pencil hardness (3H), and board surface flatness, and the performance of different batches of products is consistent, demonstrating high overall stability.

[0055] These properties are due to the synergistic effect of silicone resin and magnetic and photothermal nanoparticles. On the one hand, the magnetic and photothermal nanoparticles, as functional fillers, work with the silicone resin to increase the crosslinking density of the coating, enhancing its mechanical strength and adhesion. On the other hand, their efficient UV shielding capability, combined with the inherent chemical stability of the silicone resin, significantly delays the photo-oxidative aging of the coating, thereby effectively improving its weather resistance. Furthermore, this synergistic effect also helps optimize the surface energy, thermal conductivity, and mechanical properties of the coating, thus improving its de-icing function. Therefore, this system not only enhances the coating's impact resistance, abrasion resistance, and scratch resistance, but also addresses the mechanistic issue of early failure that traditional coatings are prone to in harsh environments.

[0056] In summary, the de-icing and high-weather-resistant coating for color-coated steel sheets developed in this invention achieves a balance between high surface hardness and good processing performance while possessing excellent de-icing performance and long-term weather resistance. This coating system exhibits significantly better overall performance than traditional coatings and demonstrates greater economic competitiveness.

[0057] Although the present invention has been described in detail above with general descriptions and specific embodiments, modifications or improvements can be made to it, which will be obvious to those skilled in the art. Therefore, all such modifications or improvements made without departing from the spirit of the present invention fall within the scope of protection claimed by the present invention.

Claims

1. A de-icing and high weather-resistant coating for color-coated steel sheets, characterized in that, The raw material components include the following parts by weight: Organosilicon resin: 30-50 parts; High weather-resistant inorganic pigments and fillers: 26-40 parts; Magnetic and photothermal nanoparticles: 1-4 parts; Additives: 2-8 parts; Solvent: 10-20 parts; Hardener: 3-16 parts.

2. The de-icing and high weather-resistant coating for color-coated steel sheets as described in claim 1, characterized in that, The silicone resin comprises the following raw material components in parts by weight: Polyols: 20-30 parts; Polybasic acids: 20-30 parts; Organosilicon monomer: 10-20 parts; Catalyst: 0.1-0.2 parts; Antioxidant: 0.1-0.2 parts.

3. The de-icing and high weather-resistant coating for color-coated steel sheets as described in claim 1, characterized in that, The high weather-resistant inorganic pigments and fillers are selected from at least one of coated titanium dioxide, ceramic pigments, and precipitated barium sulfate; the magnetic and photothermal nanoparticles are selected from at least one of iron oxide nanoparticles, semiconductor nanoparticles doped with magnetic elements, and γ-Fe2O3@carbon-based materials; the additives are selected from at least one of dispersants, polyester leveling agents, defoamers, catalysts, anti-settling agents, antioxidants, and ultraviolet light absorbers; the solvent is selected from at least one of solvent oil 100#, ethylene glycol butyl ether, propylene glycol methyl ether acetate, and DBE; and the curing agent is selected from at least one of all-methyl ether amino resins, partially methyl etherified amino resins, and blocked HDI curing agents.

4. The de-icing and high weather-resistant coating for color-coated steel sheets as described in claim 2, characterized in that, The polyol is selected from at least one of neopentyl glycol, methyl propylene glycol, trimethylolpropane, and 1,6-hexanediol; the polyacid is selected from at least one of terephthalic acid, phthalic anhydride, isophthalic acid, adipic acid, and trimellitic anhydride; the organosilicon monomer is selected from at least one of methyltrimethoxysilane, diphenyldimethoxysilane, and hydroxyl-terminated polydimethylsiloxane; the antioxidant is at least one of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and tris(2,4-di-tert-butylphenyl)phosphite; and the catalyst is selected from at least one of dibutyltin oxide, monobutyltin oxide, and tetraisopropyl titanate.

5. A method for preparing a de-icing and high weather-resistant coating for color-coated steel sheets, characterized in that, Includes the following steps: S1. Preparation of organosilicon resin; S2. Preparation of organosilicon color paste; S3. Preparation of organosilicon coatings; S4, pre-dispersed magnetic and photothermal nanoparticles; S5. Mix the organosilicon coating with pre-dispersed magnetic and photothermal nanoparticles to prepare a de-icing and high weather-resistant coating for color-coated steel sheets.

6. The preparation method of the de-icing and high weather-resistant coating for color-coated steel sheets as described in claim 5, characterized in that, The mass ratio of the organosilicon coating to the pre-dispersed magnetic and photothermal nanoparticles in step S5 is 30:

1.

7. The preparation method of the de-icing and high weather-resistant coating for color-coated steel sheets as described in claim 5, characterized in that, The specific steps for pre-dispersing magnetic and photothermal nanoparticles in step S4 are as follows: Solvent and magnetic and photothermal nanoparticles were mixed at a mass ratio of 2:

1. The magnetic and photothermal nanoparticles were dispersed using ultrasound and reacted for 30 minutes to obtain a pre-dispersed nanoslurry. The obtained pre-dispersed nanoslurry was then mixed with organosilicon resin at a mass ratio of 1:10 and added to a disperser. The system was dispersed uniformly at a dispersion speed of 700 r / min to ensure a fineness ≤15 μm, thus obtaining pre-dispersed magnetic and photothermal nanoparticles.

8. The preparation method of the de-icing and high weather-resistant coating for color-coated steel sheets as described in claim 5, characterized in that, The preparation process of the organosilicon resin in step S1 is as follows: Polyols, polyacids, organosilicon monomers, and antioxidants are added to a reactor in proportion, and nitrogen is introduced to replace the reaction system. When the temperature rises to 230℃, a catalyst is added, and the system is kept at atmospheric pressure for 2-4 hours to carry out a dehydration reaction until the acid value drops to 50-100 mg KOH / g. The system pressure is reduced to 100-500 Pa, the temperature is kept constant, and the reaction continues for 3-6 hours until the acid value is <10 mg KOH / g and the viscosity reaches 35-45 s, thus obtaining organosilicon resin.

9. The preparation method of the de-icing and high weather-resistant coating for color-coated steel sheets as described in claim 5, characterized in that, The preparation process of the organosilicon color paste in step S2 is as follows: Add the silicone resin and solvent to the mixing tank in proportion, stir at 700 r / min and slowly add the additives, stir for 8-12 minutes until completely dissolved; add the high weather-resistant inorganic pigments and fillers in 2-3 portions, stirring at 700 r / min until initially wetted; after the materials are mixed evenly and there are no abnormal lumps on the tank wall, adjust the speed to 1500 r / min and continue to disperse for 30 minutes until evenly dispersed to obtain the pre-dispersed slurry; The obtained pre-dispersed slurry was transferred to a sand mill and ground to a fineness of ≤10μm to obtain organosilicon color paste.

10. The preparation method of the de-icing and high weather-resistant coating for color-coated steel sheets as described in claim 5, characterized in that, The preparation process of the organosilicon coating in step S3 is as follows: Premixing stage: Add part of the silicone resin and part of the solvent to the mixing tank in sequence, and stir at 500-800 r / min for 5-10 min until the mixture is uniform; keep the speed constant and continue stirring, and add dispersant, anti-settling agent and high weather-resistant inorganic pigments and fillers in sequence, and stir at 1000 r / min for 60 min to obtain pre-dispersed slurry; Grinding stage: The pre-dispersed slurry obtained above is transferred to a sand mill for grinding until the fineness is <10μm to obtain a grinding slurry; Mixing and preparing the paint: Add the silicone color paste and the remaining silicone resin to a mixing tank containing the grinding slurry, and stir at 500-800 r / min for 5-10 min until the mixture is uniform; add the curing agent, polyester leveling agent, defoamer, catalyst, antioxidant, ultraviolet light absorber and the remaining solvent in sequence, and continue stirring at the same speed for 30 min until the mixture is uniform to obtain the silicone coating.

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