A high-flash-point phenolic anticorrosive coating and its preparation method and application

Abstract

The present invention belongs to the field of coating technology, and specifically relates to a high-flash-point phenolic anti-corrosion coating, a preparation method thereof, and an application thereof. The high-flash-point phenolic anti-corrosion coating comprises, by weight, 40-70 parts of xylene phenolic resin, 30-60 parts of hyperbranched polyester-modified phenolic resin, 10-15 parts of silicone-acrylic emulsion, 5-10 parts of modified glass fiber, 5-10 parts of pigment, 3-8 parts of solvent, 3-8 parts of a light stabilizer, a β-cyclodextrin inclusion complex, and 1-3 parts of a drying agent. The coating obtained from the phenolic anti-corrosion coating provided by the present invention has good adhesion, flexibility, long-term salt spray resistance, weather resistance, and resistance to moisture and heat.

Description

Technical Field

[0001] The invention belongs to the technical field of coatings, and in particular relates to a phenolic anti-corrosion coating with a high flash point, a preparation method thereof, and an application thereof. Background Art

[0002] Phenolic resin coatings are widely used in wood, furniture, construction, machinery, motors, ships and chemical anti-corrosion coatings due to the advantages of their coating films such as high hardness, chemical corrosion resistance and insulation.

[0003] Traditional phenolic resin coatings use phenolic resin as the main film-forming substance, and are composed of 200# solvent oil, pigments, fillers, and drying agents. They have the following problems: (1) The presence of solvent oil causes the phenolic resin coating to have a low flash point and low safety; (2) During construction, a large amount of organic solvents are required for dilution, resulting in a high VOC content; (3) The weather resistance is poor.

[0004] To address these issues, Chinese patent publication CN113861795A discloses an environmentally friendly high-flash-point phenolic anticorrosive coating and its preparation process, comprising the following steps: S1: preparing a modified phenolic resin, a modified alkyd resin, and a composite drier; S2: uniformly mixing the modified phenolic resin, modified alkyd resin, a high-flash-point solvent, a composite drier, melamine pyrophosphate, a pigment, and an additive, reacting for 30-45 minutes, grinding for 30-45 minutes, filtering, adding a silicone acrylic emulsion, and uniformly mixing to obtain the anticorrosive coating. The coating prepared by this process exhibits low VOC content, excellent UV resistance, mechanical properties, corrosion resistance, water resistance, and flame retardancy, and is environmentally friendly and non-toxic. However, long-term testing of this technical solution has shown poor salt spray and weathering resistance.

[0005] Chinese patent publication number CN112980230A discloses an anti-corrosion coating containing a modified phenolic resin. The coating comprises a modified phenolic resin and an anti-corrosion coating. The modified phenolic resin is made from para-tert-butylphenol, paraformaldehyde, pentaerythritol, glycerol, rosin, catalyst A, catalyst B, an antioxidant, and high-purity nitrogen. The rosin, glycerol, pentaerythritol, and catalyst are used in a mass ratio of 100:5.5:7:0.1, and the para-tert-butylphenol, paraformaldehyde, and catalyst are used in a mass ratio of 100:30:0.1. This technical solution introduces a rosin ester into a phenolic resin system to form a copolymer. This copolymer is then added to an anti-corrosion coating system based on an epoxy ester, improving the coating's drying speed, water resistance, and adhesion. However, this solution has a curing time of up to five days, which may lead to the risk of bottom biting during construction. Summary of the Invention

[0006] In response to the above problems, the present invention provides a phenolic anti-corrosion coating with a high flash point, a preparation method thereof, and an application thereof. The coating obtained by the phenolic anti-corrosion coating provided by the present invention has good adhesion, flexibility, long-term salt spray resistance, weather resistance, and moisture and heat resistance.

[0007] To achieve the above object, the technical solution adopted by the present invention is as follows:

[0008] The first aspect of the present invention provides a high-flash-point phenolic anti-corrosion coating. The raw materials include, by mass, 40-70 parts of xylene phenolic resin, 30-60 parts of hyperbranched polyester modified phenolic resin, 10-15 parts of silicone acrylic emulsion, 5-10 parts of modified glass fiber, 5-10 parts of pigment, 3-8 parts of solvent, 3-8 parts of light stabilizer-β-cyclodextrin inclusion complex, and 1-3 parts of drying agent.

[0009] Preferably, the xylene phenolic resin is prepared from raw materials consisting of 20 parts of first formaldehyde, 10 parts of sulfuric acid, 25 parts of xylene, 10 parts of phenol, 0.1 parts of hydrochloric acid, 1 part of sodium hydroxide, 12 parts of second formaldehyde, and 20 parts of ethanol, in parts by mass.

[0010] Preferably, the preparation method of the xylene phenolic resin is as follows: first, formaldehyde and sulfuric acid are uniformly mixed;

[0011] Add xylene, react at 70℃ for 8h, let stand for 15min, remove the lower layer solution, wash with water until neutral, vacuum the product until no more precipitates are present, cool to 25℃, add phenol, and when the temperature reaches 40℃,

[0012] Add hydrochloric acid, heat to 93°C, react for 15 minutes, react at 95°C for another 20 minutes, quickly cool to 40°C, add sodium hydroxide, react for 10 minutes, add the second formaldehyde, heat to 90°C, react for 35 minutes, dehydrate at 75°C, cool to 60°C, add ethanol to adjust the solid content to 80%, and obtain xylene phenol-formaldehyde resin.

[0013] The preparation method of the hyperbranched polyester modified phenolic resin comprises the following steps: uniformly mixing formaldehyde, phenol, hydroxyl-terminated hyperbranched polyester and water, adding sodium hydroxide for a first reaction to obtain an intermediate; adding nano-titanium dioxide to the intermediate for a second reaction, dehydrating after the reaction, adding ethanol and mixing uniformly to obtain the hyperbranched polyester modified phenolic resin.

[0014] The inventors' previous research used a compound of xylene phenolic resin and modified alkyd resin. However, after long-term testing, it was found that the salt spray resistance and weather resistance of this technical solution were poor, and it was not suitable for the protection of outdoor equipment / facilities at the seaside. In order to solve this technical problem, the inventors creatively prepared a hyperbranched polyester modified phenolic resin, and compounded the hyperbranched polyester modified phenolic resin with xylene phenolic resin. This not only improved the adhesion and flexibility of the coating, but also improved its salt spray resistance and weather resistance. It is speculated that this is because the phenolic resin is first modified with a terminal hydroxyl hyperbranched polyester. The terminal hydroxyl hyperbranched polyester contains a large number of terminal hydroxyl groups, which can participate in the reaction of formaldehyde and phenol. The invention relates to a novel nanostructured polymer modified with nano-titanium dioxide, which is a kind of nanostructured polymer with a high molecular weight, high molecular weight and high molecular weight. The invention also relates to a nanostructured polymer modified with nano-titanium dioxide, which is a kind of nanostructured polymer with a high molecular weight, high molecular weight and high molecular weight. The invention ...

[0015] Preferably, the hydroxyl-terminated hyperbranched polyester is an aliphatic hyperbranched polyester, specifically sourced from Wuhan Hyperbranched Resin Technology Co., Ltd., model: H102.

[0016] Preferably, the mass ratio of the formaldehyde, phenol, terminal hydroxyl hyperbranched polyester and water is (0.4-0.5):1:(0.05-0.15):(2-4), preferably 0.45:1:0.1:3.1.

[0017] Preferably, the mass ratio of the sodium hydroxide to the phenol is (2-4):100.

[0018] Preferably, the temperature of the first reaction is 80-90° C., and the time of the first reaction is 2-4 h.

[0019] Preferably, the mass ratio of the intermediate to nano-titanium dioxide is 1:(0.1-0.3).

[0020] Preferably, the nano titanium dioxide is anatase nano titanium dioxide with a particle size of 10-30 nm, preferably 20 nm.

[0021] Preferably, the temperature of the second reaction is 60-80° C., and the time of the second reaction is 4-8 hours.

[0022] Preferably, the amount of ethanol added is such that the solid content of the hyperbranched polyester modified phenolic resin is 70-80%.

[0023] Preferably, the solid content of the silicone acrylic emulsion is 48±1 wt %, specifically sourced from Jiangsu Shengda New Material Technology Co., Ltd., model: SD-5281 nano silicone acrylic emulsion.

[0024] Preferably, the preparation method of the modified glass fiber comprises the following steps: uniformly mixing carboxylated glass fiber, amino-treated hexagonal boron nitride, epichlorohydrin and water, conducting a hydrothermal reaction, and filtering, washing and drying the reaction product in sequence after the hydrothermal reaction to obtain an intermediate product; dispersing the intermediate product in an ethanol aqueous solution, adding ethyl orthosilicate and ammonia water to carry out a stirring reaction, and filtering, washing and drying the reaction product in sequence after the stirring reaction to obtain a modified glass fiber.

[0025] Outdoor equipment / facilities at the seaside are subject to high temperature and high humidity, and the air contains high salt content, which can cause serious corrosion and damage to the equipment / facilities. Therefore, it is crucial to evaluate the moisture and heat resistance of phenolic anti-corrosion coatings. The inventors have found that phenolic anti-corrosion coatings prepared solely by compounding xylene phenolic resin and hyperbranched polyester-modified phenolic resin have poor moisture and heat resistance. To address the above technical problems, the inventors have creatively prepared modified glass fibers. First, the carboxyl groups in the carboxylated glass fibers react with the amino groups in the amino hexagonal boron nitride to graft the amino hexagonal boron nitride onto the surface of the glass fibers. Silica is then loaded onto the surface of the glass fibers. Through the above technical solution, the combined action of the glass fibers, hexagonal boron nitride, and silica is utilized to further improve the continuity and density of the coating. In addition, the modified glass fibers can form hydrogen bonds with the phenolic resin modified with the hydroxyl-terminated hyperbranched polyester, which not only improves the dispersibility of the modified glass fibers but also facilitates the formation of a staggered structure, thereby improving the moisture and heat resistance of the coating, while also improving salt spray resistance and flexibility.

[0026] However, during the experiment, the inventors found that the moisture and heat resistance, flexibility and salt spray resistance of the glass fiber modified by carboxylation with a mixed acid were poor, while the moisture and heat resistance, salt spray resistance and flexibility of the coating were excellent when the glass fiber was carboxylated with 3-[3-carboxyallylamide]propyltriethoxysilane. It is speculated that this is because 3-[3-carboxyallylamide]propyltriethoxysilane can simultaneously introduce carboxyl groups and organic chains on the surface of the glass fiber, and the organic chain can improve the dispersibility of the glass fiber in the system and is conducive to the formation of a staggered structure, thereby improving the flexibility, salt spray resistance and moisture and heat resistance of the coating.

[0027] Further preferably, the preparation method of the modified glass fiber comprises the following steps: uniformly mixing carboxylated glass fiber, amino hexagonal boron nitride, epichlorohydrin and water, conducting a hydrothermal reaction at 100-110°C for 2-4 hours, and filtering, washing and drying the reaction product in sequence after the hydrothermal reaction to obtain an intermediate product; dispersing the intermediate product in an ethanol aqueous solution, adding ethyl orthosilicate and ammonia water, and stirring the reaction at 25-30°C for 2-3 hours. After the stirring reaction, filtering, washing and drying the reaction product in sequence to obtain a modified glass fiber.

[0028] Preferably, the mass ratio of the carboxylated glass fiber, aminoated hexagonal boron nitride, epichlorohydrin and water is 1:(0.5-0.8):(0.3-0.5):(40-60), preferably 1:0.7:0.4:50.

[0029] Preferably, the mass ratio of the intermediate product, ethanol aqueous solution, tetraethyl orthosilicate and ammonia water is 1:(30-40):(0.7-0.9):(0.9-1.1), preferably 1:25:0.8:1.

[0030] Preferably, the concentration of the ethanol aqueous solution is 60-80 wt%.

[0031] Preferably, the preparation method of the carboxylated glass fiber is: glass fiber, 3-[3-carboxyallylamide]propyltriethoxysilane and ethanol are mixed, and stirred to react. After the stirring reaction is completed, the product is filtered, washed and dried to obtain the carboxylated glass fiber.

[0032] Further preferably, the preparation method of the carboxylated glass fiber is: mixing glass fiber, 3-[3-carboxyallylamide]propyltriethoxysilane and ethanol, stirring and reacting at 25-30°C for 4-6 hours, and after the stirring reaction is completed, filtering, washing and drying the product to obtain the carboxylated glass fiber.

[0033] The glass fiber described in the present invention is glass fiber powder, which is obtained by grinding glass fiber.

[0034] Preferably, the mass ratio of the glass fiber, 3-[3-carboxyallylamide]propyltriethoxysilane and ethanol is 1:(0.4-0.6):(10-15), preferably 1:0.5:12.

[0035] Preferably, the preparation method of the amino-modified hexagonal boron nitride is: dispersing hexagonal boron nitride in water, adding polyethyleneimine and epichlorohydrin, and stirring to react. After the stirring reaction is completed, filtering, washing, and drying the reaction product to obtain amino-modified hexagonal boron nitride.

[0036] The hexagonal boron nitride in the present invention is in powder form.

[0037] Further preferably, the preparation method of the amino-modified hexagonal boron nitride is: dispersing hexagonal boron nitride in water, adding polyethyleneimine and epichlorohydrin, stirring and reacting at 70-80°C for 2-4 hours, and filtering, washing, and drying the reaction product after the stirring reaction to obtain amino-modified hexagonal boron nitride.

[0038] Preferably, the mass ratio of hexagonal boron nitride, water, polyethyleneimine and epichlorohydrin is (1-2): (25-50): (0.5-1): (0.5-0.9), preferably 1.5:40:1:0.8.

[0039] Preferably, the pigment is selected from at least one of titanium dioxide, red iron oxide, chrome yellow, phthalocyanine green, phthalocyanine blue and carbon black.

[0040] Preferably, the solvent is selected from at least one of dipropylene glycol methyl ether, ethylene glycol diacetate, cyclohexanone and carbon tetrachloride.

[0041] Preferably, the preparation method of the light stabilizer-β-cyclodextrin inclusion complex comprises the following steps:

[0042] S1, mixing carboxymethyl-β-cyclodextrin aqueous solution, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide salt, and N-hydroxysuccinimide uniformly, and letting it stand to obtain an activated carboxymethyl-β-cyclodextrin aqueous solution;

[0043] S2, mixing the activated carboxymethyl-β-cyclodextrin aqueous solution and the aminated hollow glass microspheres, and performing an amidation reaction. After the amidation reaction, the product is centrifuged, filtered, and dried to obtain β-cyclodextrin loaded with hollow glass microspheres;

[0044] S3, mixing the light stabilizer and methanol to obtain a light stabilizer solution;

[0045] S4. Mixing the β-cyclodextrin loaded with hollow glass microspheres, the light stabilizer solution and water, and stirring the mixture for reaction. After the stirring reaction is completed, centrifuging the product, filtering and drying the product to obtain a light stabilizer-β-cyclodextrin inclusion complex.

[0046] In addition to direct sunlight, the refractive index of the sea surface to ultraviolet rays makes the ultraviolet rays at the seaside much higher than those in other places. Therefore, in order to further improve the weather resistance of phenolic anti-corrosion coatings, the inventors creatively prepared a light stabilizer-β-cyclodextrin inclusion complex. It was unexpectedly discovered that by first modifying carboxymethyl-β-cyclodextrin with amino hollow glass microspheres and then incorporating the light stabilizer, not only the weather resistance of the coating was improved, but also the moisture and heat resistance and salt spray resistance of the coating were further improved. When the amino hollow glass microspheres were replaced with amino hexagonal nitrogen When boron is added, the above effect cannot be achieved. It is speculated that this is because the hollow glass microspheres have a hollow structure inside and have a low thermal conductivity, which can isolate the external heat from being transferred to the coating to a certain extent, thereby improving the coating's resistance to moisture and heat. At the same time, the hollow structure inside the hollow glass microspheres and the space barrier effect formed are conducive to improving the inclusion effect of carboxymethyl-β-cyclodextrin on the light stabilizer, thereby improving the weather resistance of the coating; in addition, the hollow glass microspheres further form a staggered structure in the system, thereby improving the coating's salt spray resistance and moisture and heat resistance.

[0047] Preferably, the concentration of carboxymethyl-β-cyclodextrin in the carboxymethyl-β-cyclodextrin aqueous solution is 2-5 wt %.

[0048] Preferably, the mass ratio of the carboxymethyl-β-cyclodextrin, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide salt and N-hydroxysuccinimide is 1:(0.8-1):(0.5-0.7), preferably 1:0.9:0.6.

[0049] Preferably, the standing time in step S1 is 2-3 hours.

[0050] Preferably, the mass ratio of the amino hollow glass microspheres to carboxymethyl-β-cyclodextrin is 1:(3-5).

[0051] Preferably, the temperature of the amidation reaction in step S2 is 25-30° C., and the duration of the amidation reaction is 8-12 h.

[0052] Preferably, the preparation method of the aminated hollow glass microspheres is: dispersing the hollow glass microspheres in water, adding polyethyleneimine and epichlorohydrin, and stirring to react, and after the stirring reaction is completed, filtering, washing, and drying the reaction product to obtain the aminated hollow glass microspheres.

[0053] Preferably, the particle size of the hollow glass microspheres is 50-70 μm, preferably 65 μm.

[0054] Further preferably, the preparation method of the aminated hollow glass microspheres is: dispersing the hollow glass microspheres in water, adding polyethyleneimine and epichlorohydrin, stirring and reacting at 70-80° C. for 2-4 hours, and filtering, washing, and drying the reaction product after the stirring reaction to obtain the aminated hollow glass microspheres.

[0055] Preferably, the mass ratio of the hollow glass microspheres, water, polyethyleneimine and epichlorohydrin is 1:(20-30):(0.5-0.8):(0.3-0.5), preferably 1:28:0.6:0.4.

[0056] Preferably, the light stabilizer is a liquid hindered amine light stabilizer containing an amino ether group.

[0057] Preferably, the mass ratio of the light stabilizer to methanol is (2-5):100.

[0058] Preferably, the mass ratio of the β-cyclodextrin, light stabilizer and water in the loaded hollow glass microspheres is 1:(1.1-1.4):(20-30), preferably 1:1.2:25.

[0059] Preferably, the stirring reaction temperature in step S4 is 25-30° C., and the stirring reaction time is 8-12 h.

[0060] Preferably, the drying agent is a mixture of cerium 2-ethylhexanoate and zirconium 2-ethylhexanoate, and the mass ratio of cerium 2-ethylhexanoate to zirconium 2-ethylhexanoate is (1-3):(1-3), preferably 1:1.

[0061] A second aspect of the present invention provides a method for preparing the above-mentioned high-flash-point phenolic anti-corrosion coating, comprising the following steps: mixing a xylene phenolic resin, a hyperbranched polyester-modified phenolic resin, a modified glass fiber, a pigment, a light stabilizer-β-cyclodextrin inclusion complex and a solvent, stirring, adding a silicone acrylic emulsion, mixing uniformly, and continuing to stir to obtain the high-flash-point phenolic anti-corrosion coating.

[0062] Preferably, the preparation method of the high-flash-point phenolic anti-corrosion coating comprises the following steps: mixing xylene phenolic resin, hyperbranched polyester modified phenolic resin, modified glass fiber, pigment, light stabilizer-β-cyclodextrin inclusion complex and solvent, stirring at 3000-4000 r / min for 30-40 minutes, adding silicone acrylic emulsion, mixing evenly, and continuing to stir at 3000-4000 r / min for 30-40 minutes to obtain the high-flash-point phenolic anti-corrosion coating.

[0063] The third aspect of the present invention provides the use of the above-mentioned high-flash-point phenolic anti-corrosion coating in the field of outdoor metal substrate protection.

[0064] Compared with the prior art, the present invention has the following beneficial effects:

[0065] 1. The present invention creatively prepares a hyperbranched polyester modified phenolic resin, and compounding the hyperbranched polyester modified phenolic resin with a xylene phenolic resin not only improves the adhesion and flexibility of the coating, but also improves the salt spray resistance and weather resistance.

[0066] 2. The present invention creatively prepares modified glass fiber, which not only improves the moisture and heat resistance of the coating, but also improves the salt spray resistance and flexibility.

[0067] 3. The present invention uses 3-[3-carboxyallylamide]propyltriethoxysilane to carboxylate the glass fiber, and the coating has excellent moisture and heat resistance, salt spray resistance and flexibility.

[0068] 4. The present invention creatively prepares a light stabilizer-β-cyclodextrin inclusion complex, which not only improves the weather resistance of the coating, but also further improves its moisture resistance and salt spray resistance. DETAILED DESCRIPTION

[0069] In order to have a clearer understanding of the technical features, purposes and effects of the present invention, a specific implementation scheme is now described in detail.

[0070] The present invention is further described below with reference to the following examples, but the present invention is not limited to the following examples. The implementation conditions used in the examples can be further adjusted according to the specific requirements of the application. The implementation conditions not specified are conventional conditions in the industry. The technical features involved in the various embodiments of the present invention may be combined with each other as long as they do not conflict with each other.

[0071] In the following examples and comparative examples, unless otherwise specified, all raw materials used were commercially available or prepared by conventional methods in the art.

[0072] Example 1

[0073] A high-flash-point phenolic anti-corrosion coating comprises, by weight, 40 parts of xylene phenolic resin, 30 parts of hyperbranched polyester-modified phenolic resin, 10 parts of silicone-acrylic emulsion, 5 parts of modified glass fiber, 5 parts of pigment, 3 parts of solvent, 3 parts of light stabilizer-β-cyclodextrin inclusion complex, and 1 part of drying agent.

[0074] The xylene phenolic resin is composed of raw materials, calculated by mass, consisting of 20 parts of first formaldehyde, 10 parts of sulfuric acid, 25 parts of xylene, 10 parts of phenol, 0.1 parts of hydrochloric acid, 1 part of sodium hydroxide, 12 parts of second formaldehyde, and 20 parts of ethanol.

[0075] The preparation method of the xylene phenolic resin comprises the following steps: first, uniformly mixing formaldehyde and sulfuric acid, adding xylene, reacting at 70°C for 8 hours, standing for 15 minutes, removing the lower layer solution, washing with water until neutral, vacuumizing the product until no effluent is present, cooling to 25°C, adding phenol, adding hydrochloric acid when the temperature reaches 40°C, heating to 93°C, reacting for 15 minutes, reacting at 95°C for another 20 minutes, rapidly cooling to 40°C, adding sodium hydroxide, reacting for 10 minutes, adding a second formaldehyde, heating to 90°C, reacting for 35 minutes, dehydrating at 75°C, cooling to 60°C, and adding ethanol to adjust the solid content to 80%, thereby obtaining the xylene phenolic resin.

[0076] The preparation method of the hyperbranched polyester modified phenolic resin comprises the following steps: uniformly mixing formaldehyde, phenol, a hydroxyl-terminated hyperbranched polyester and water, adding sodium hydroxide and carrying out a first reaction at 85° C. for 3 hours to obtain an intermediate; adding nano-titanium dioxide to the intermediate and carrying out a second reaction at 70° C. for 6 hours; dehydrating after the reaction, adding ethanol so that the solid content of the hyperbranched polyester modified phenolic resin is 70%, and uniformly mixing to obtain the hyperbranched polyester modified phenolic resin.

[0077] The hydroxyl-terminated hyperbranched polyester is an aliphatic hyperbranched polyester purchased from Wuhan Hyperbranched Resin Technology Co., Ltd., model: H102.

[0078] The mass ratio of the formaldehyde, phenol, terminal hydroxyl hyperbranched polyester and water is 0.45:1:0.1:3.1.

[0079] The mass ratio of the sodium hydroxide to the phenol is 3:100.

[0080] The mass ratio of the intermediate to nano-titanium dioxide is 1:0.2.

[0081] The nano titanium dioxide is anatase nano titanium dioxide with a particle size of 20 nm, purchased from Xuancheng Jingrui New Materials Co., Ltd., model: VK-TA18.

[0082] The solid content of the silicone acrylic emulsion is 48±1 wt %, and it is purchased from Jiangsu Shengda New Material Technology Co., Ltd., model: SD-5281 nano silicone acrylic emulsion.

[0083] The modified glass fiber preparation method comprises: uniformly mixing carboxylated glass fiber, amino hexagonal boron nitride, epichlorohydrin (CAS No.: 106-89-8) and water, performing a hydrothermal reaction at 100° C. for 3 hours, filtering, washing and drying the reaction product in sequence after the hydrothermal reaction to obtain an intermediate product; dispersing the intermediate product in an ethanol aqueous solution, adding tetraethyl orthosilicate (CAS No.: 78-10-4) and ammonia water, performing a stirring reaction at 25° C. for 2.5 hours, and filtering, washing and drying the reaction product in sequence after the stirring reaction to obtain the modified glass fiber.

[0084] The mass ratio of the carboxylated glass fiber, aminoated hexagonal boron nitride, epichlorohydrin and water is 1:0.7:0.4:50.

[0085] The mass ratio of the intermediate product, ethanol aqueous solution, ethyl orthosilicate and ammonia water is 1:25:0.8:1.

[0086] The concentration of the ethanol aqueous solution is 70 wt %.

[0087] The preparation method of the carboxylated glass fiber comprises: mixing glass fiber, 3-[3-carboxyallylamide]propyltriethoxysilane (CAS No.: 50488-14-7) and ethanol, stirring and reacting at 25° C. for 5 hours, and filtering, washing and drying the product after the stirring reaction to obtain the carboxylated glass fiber.

[0088] The mass ratio of the glass fiber, 3-[3-carboxyallylamide]propyltriethoxysilane and ethanol is 1:0.5:12.

[0089] The glass fiber is glass fiber powder purchased from Tai'an Zhongshuo Glass Fiber Products Co., Ltd., model: EMG-35.

[0090] The preparation method of the amino-modified hexagonal boron nitride comprises: dispersing hexagonal boron nitride in water, adding polyethyleneimine (CAS No.: 9002-98-6) and epichlorohydrin, stirring and reacting at 75°C for 3 hours, and filtering, washing, and drying the reaction product after the stirring reaction to obtain the amino-modified hexagonal boron nitride.

[0091] The hexagonal boron nitride was purchased from Henan Boron Nitride New Material Technology Co., Ltd., model: PBN100.

[0092] The mass ratio of the hexagonal boron nitride, water, polyethyleneimine and epichlorohydrin is 1.5:40:1:0.8.

[0093] The pigment is titanium dioxide, purchased from China National Nuclear Huayuan Titanium Dioxide Co., Ltd., model: R-2219.

[0094] The solvent is carbon tetrachloride (CAS No.: 56-23-5).

[0095] The preparation method of the light stabilizer-β-cyclodextrin inclusion complex is as follows:

[0096] S1. Mix carboxymethyl-β-cyclodextrin aqueous solution, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide salt (CAS No.: 1892-57-5), and N-hydroxysuccinimide (CAS No.: 6066-82-6) evenly, and let it stand for 3 hours to obtain an activated carboxymethyl-β-cyclodextrin aqueous solution;

[0097] S2, mixing the activated carboxymethyl-β-cyclodextrin aqueous solution and the aminated hollow glass microspheres, and performing an amidation reaction at 25° C. for 10 h. After the amidation reaction, the product is centrifuged, filtered, and dried to obtain β-cyclodextrin loaded with hollow glass microspheres;

[0098] S3, mixing the light stabilizer and methanol to obtain a light stabilizer solution;

[0099] S4. Mix the β-cyclodextrin loaded with hollow glass microspheres, the light stabilizer solution and water, and stir the mixture at 25° C. for 10 hours. After the stirring reaction, centrifuge the product, filter and dry it to obtain a light stabilizer-β-cyclodextrin inclusion complex.

[0100] The concentration of carboxymethyl-β-cyclodextrin in the carboxymethyl-β-cyclodextrin aqueous solution is 3 wt %.

[0101] The carboxymethyl-β-cyclodextrin was purchased from Hubei Xinhongli Chemical Co., Ltd., item number: LI3330.

[0102] The mass ratio of the carboxymethyl-β-cyclodextrin, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide salt and N-hydroxysuccinimide is 1:0.9:0.6.

[0103] The mass ratio of the amino hollow glass microspheres to carboxymethyl-β-cyclodextrin is 1:4.

[0104] The preparation method of the aminated hollow glass microspheres comprises the following steps: dispersing the hollow glass microspheres in water, adding polyethyleneimine and epichlorohydrin, stirring and reacting at 75° C. for 3 hours, and filtering, washing, and drying the reaction product after the stirring reaction to obtain the aminated hollow glass microspheres.

[0105] The hollow glass microspheres have a particle size of 65 μm and are purchased from Wenzhou Weizhen New Materials Co., Ltd., model number: 7015.

[0106] The mass ratio of the hollow glass microspheres, water, polyethyleneimine and epichlorohydrin is 1:28:0.6:0.4.

[0107] The light stabilizer is a liquid hindered amine light stabilizer containing an amino ether group, and its trade name is TINUVIN 123 BASF UV light stabilizer.

[0108] The mass ratio of the light stabilizer to methanol is 4:100.

[0109] The mass ratio of the β-cyclodextrin, light stabilizer and water in the loaded hollow glass microspheres is 1:1.2:25.

[0110] The drying agent is a mixture of cerium 2-ethylhexanoate (CAS No.: 56797-01-4) and zirconium 2-ethylhexanoate (CAS No.: 2233-42-3), and the mass ratio of the cerium 2-ethylhexanoate to the zirconium 2-ethylhexanoate is 1:1.

[0111] The preparation method of the above-mentioned high-flash point phenolic anti-corrosion coating is as follows: xylene phenolic resin, hyperbranched polyester modified phenolic resin, modified glass fiber, pigment, light stabilizer-β-cyclodextrin inclusion complex and solvent are mixed, stirred at 4000 r / min for 40 minutes, silicone acrylic emulsion is added, mixed evenly, and continued to stir at 4000 r / min for 30 minutes to obtain the high-flash point phenolic anti-corrosion coating.

[0112] Example 2

[0113] The difference from Example 1 is that the high flash point phenolic anti-corrosion coating, calculated by mass, consists of 70 parts of xylene phenolic resin, 60 parts of hyperbranched polyester modified phenolic resin, 15 parts of silicone acrylic emulsion, 10 parts of modified glass fiber, 10 parts of pigment, 8 parts of solvent, 8 parts of light stabilizer-β-cyclodextrin inclusion complex, and 3 parts of drying agent; the rest are the same.

[0114] The preparation method of the above-mentioned high flash point phenolic anti-corrosion coating is the same as that in Example 1.

[0115] Example 3

[0116] The difference from Example 1 is that the high flash point phenolic anti-corrosion coating, calculated by mass, consists of 60 parts of xylene phenolic resin, 45 parts of hyperbranched polyester modified phenolic resin, 12 parts of silicone acrylic emulsion, 8 parts of modified glass fiber, 8 parts of pigment, 6 parts of solvent, 6 parts of light stabilizer-β-cyclodextrin inclusion complex, and 2 parts of drying agent; the rest are the same.

[0117] The preparation method of the above-mentioned high flash point phenolic anti-corrosion coating is the same as that in Example 1.

[0118] Comparative Example 1

[0119] The difference from Example 3 is that the hyperbranched polyester-modified phenolic resin is replaced by an equal-mass hyperbranched polysilane-modified phenolic resin, and the hyperbranched polysilane-modified phenolic resin is prepared by the preparation method of Example 2 disclosed in Chinese Patent Publication No. CN 116948120A; the rest are the same.

[0120] Comparative Example 2

[0121] The difference from Example 3 is that the preparation method of the hyperbranched polyester modified phenolic resin is: formaldehyde, phenol, terminal hydroxyl hyperbranched polyester and water are uniformly mixed, and sodium hydroxide is added to carry out a first reaction to obtain the hyperbranched polyester modified phenolic resin; the rest are the same.

[0122] Comparative Example 3

[0123] The difference from Example 3 is that the amino-treated hexagonal boron nitride is replaced with amino-treated glass microspheres of the same mass; the rest are the same.

[0124] Comparative Example 4

[0125] The difference from Example 3 is that the preparation method of the carboxylated glass fiber is: adding the glass fiber to a mixed acid of concentrated sulfuric acid and nitric acid, stirring and reacting at 110°C for 3 hours, and after the reaction is completed, centrifuging, washing, and drying to obtain the carboxylated glass fiber; the ratio of the glass fiber, concentrated sulfuric acid, and nitric acid is 1g:12mL:4mL; the rest are the same.

[0126] Comparative Example 5

[0127] The difference from Example 3 is that the amino-treated hollow glass microspheres are replaced with amino-treated hexagonal boron nitride of the same mass; the rest are the same.

[0128] Comparative Example 6

[0129] The difference from Example 3 is that the preparation method of the light stabilizer-β-cyclodextrin inclusion complex is:

[0130] S1, mixing carboxymethyl-β-cyclodextrin aqueous solution, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide salt, and N-hydroxysuccinimide uniformly, and letting it stand to obtain an activated carboxymethyl-β-cyclodextrin aqueous solution;

[0131] S2, mixing the light stabilizer and methanol to obtain a light stabilizer solution;

[0132] S3. Mix the activated carboxymethyl-β-cyclodextrin aqueous solution and the light stabilizer solution, and stir to react. After the stirring reaction, centrifuge the product, filter, and dry to obtain a light stabilizer-β-cyclodextrin inclusion complex; the mass ratio of the carboxymethyl-β-cyclodextrin to the light stabilizer is 1:1.2; and the rest are the same.

[0133] Comparative Example 7

[0134] The anti-corrosion coating prepared in Example 3 disclosed in Chinese patent publication number CN 113861795 A.

[0135] Test Example 1

[0136] The flash points of the anti-corrosion coatings of Examples 1-3 and Comparative Examples 1-7 were tested using the GB / T 5208-2008 standard, and the results were all greater than 61°C.

[0137] Test Example 2

[0138] The anti-corrosion coatings of Examples 1-3 and Comparative Examples 1-7 were applied to the surface of tinplate, respectively, with a coating thickness of 300 μm, and the following performance tests were performed:

[0139] ① Adhesion: refer to GB / T5210-2006 standard;

[0140] ② Drying time: refer to GB / T1728-1979 standard;

[0141] ③Flexibility: Refer to GB / T 1731-2020 standard;

[0142] ④ Salt spray resistance: Refer to GB / T 10125-2021 standard, neutral salt spray test, time: if there is no cracking, blistering or peeling within 2 months (1440h), it is considered qualified, otherwise it is considered unqualified;

[0143] ⑤ Weather resistance: Refer to GB / T 23987-2009 standard, use type II lamp, and use method B for exposure. If there is no cracking, shedding, powdering or blistering within 1 month (720h), it is considered qualified; otherwise, it is considered unqualified.

[0144] ⑥ Resistance to moisture and heat: Refer to GB / T1740-2007 standard. If there is no blistering, cracking or falling off within 1 month (720h), it is considered qualified, otherwise it is considered unqualified.

[0145] The test results are shown in Table 1.

[0146] Table 1 Test results of anticorrosive coatings of Examples 1-3 and Comparative Examples 1-7

[0147]

[0148] As can be seen from Table 1, the coatings obtained from the anticorrosive coatings of Examples 1-3 have good adhesion, flexibility, long-term salt spray resistance, weather resistance, and resistance to moisture and heat;

[0149] In Comparative Example 1, since the hyperbranched polyester-modified phenolic resin was replaced with a hyperbranched polysilane-modified phenolic resin of equal mass, the adhesion and flexibility of the resulting coating decreased, and the long-term salt spray resistance and weather resistance tests failed.

[0150] In Comparative Example 2, since titanium dioxide was not grafted into the hyperbranched polyester-modified phenolic resin, the resulting coating showed reduced flexibility and failed the long-term salt spray resistance and weather resistance tests.

[0151] In Comparative Example 3, since the amino-treated hexagonal boron nitride was replaced with amino-treated glass microbeads of equal mass, the resulting coating had reduced flexibility and failed the long-term salt spray resistance and humidity and heat resistance tests.

[0152] In Comparative Example 4, due to the change in the preparation method of the carboxylated glass fiber, the flexibility of the coating obtained decreased, and the long-term tests of salt spray resistance and heat and humidity resistance failed;

[0153] In Comparative Example 5, since the amination hollow glass microspheres were replaced with amination hexagonal boron nitride of equal mass, the flexibility of the obtained coating decreased and the long-term tests of salt spray resistance, weather resistance and heat and humidity resistance failed;

[0154] In Comparative Example 6, since carboxymethyl-β-cyclodextrin was not modified with aminated hollow glass microspheres, the obtained coating failed the long-term tests of salt spray resistance, weather resistance, and heat and humidity resistance, and its flexibility was also reduced.

[0155] The anti-corrosion coating of the technical solution disclosed in Comparative Example 7 failed the long-term test of salt spray resistance, weather resistance and heat and humidity resistance.

[0156] Finally, it should be noted that the above content is only used to illustrate the technical solution of the present invention, rather than to limit the scope of protection of the present invention. Simple modifications or equivalent substitutions of the technical solution of the present invention by ordinary technicians in this field do not deviate from the essence and scope of the technical solution of the present invention.

Claims

1. A high flash point phenolic anti-corrosion coating, characterized in that: The raw materials include, by mass: 40-70 parts of xylene phenolic resin, 30-60 parts of hyperbranched polyester modified phenolic resin, 10-15 parts of silicone acrylic emulsion, 5-10 parts of modified glass fiber, 5-10 parts of pigment, 3-8 parts of solvent, 3-8 parts of light stabilizer-β-cyclodextrin inclusion compound, and 1-3 parts of drying agent; The preparation method of the hyperbranched polyester modified phenolic resin comprises the following steps: uniformly mixing formaldehyde, phenol, a hydroxyl-terminated hyperbranched polyester and water, adding sodium hydroxide to carry out a first reaction to obtain an intermediate; adding nano-titanium dioxide to the intermediate to carry out a second reaction, dehydrating after the reaction, adding ethanol and mixing uniformly to obtain a hyperbranched polyester modified phenolic resin; The modified glass fiber preparation method comprises the following steps: uniformly mixing carboxylated glass fiber, amino-treated hexagonal boron nitride, epichlorohydrin, and water, performing a hydrothermal reaction, filtering, washing, and drying the reaction product in sequence after the hydrothermal reaction to obtain an intermediate product; dispersing the intermediate product in an ethanol aqueous solution, adding ethyl orthosilicate and ammonia water to carry out a stirring reaction, and filtering, washing, and drying the reaction product in sequence after the stirring reaction to obtain the modified glass fiber; The preparation method of the carboxylated glass fiber comprises the following steps: mixing glass fiber, 3-[3-carboxyallylamide]propyltriethoxysilane and ethanol, stirring and reacting the mixture, filtering, washing and drying the product after the stirring reaction, and obtaining the carboxylated glass fiber; Preparation method of the light stabilizer-β-cyclodextrin inclusion complex: S1, mixing carboxymethyl-β-cyclodextrin aqueous solution, 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide salt, and N-hydroxysuccinimide uniformly, and letting it stand to obtain an activated carboxymethyl-β-cyclodextrin aqueous solution; S2, mixing the activated carboxymethyl-β-cyclodextrin aqueous solution and the aminated hollow glass microspheres, and performing an amidation reaction. After the amidation reaction, the product is centrifuged, filtered, and dried to obtain β-cyclodextrin loaded with hollow glass microspheres; S3, mixing the light stabilizer and methanol to obtain a light stabilizer solution; S4. Mixing the β-cyclodextrin loaded with hollow glass microspheres, the light stabilizer solution and water, and stirring the mixture for reaction. After the stirring reaction is completed, centrifuging the product, filtering and drying the product to obtain a light stabilizer-β-cyclodextrin inclusion complex.

2. The high flash point phenolic anticorrosive coating according to claim 1, characterized in that: The mass ratio of the carboxylated glass fiber, aminoated hexagonal boron nitride, epichlorohydrin and water is 1: (0.5-0.8): (0.3-0.5): (40-60); the mass ratio of the intermediate product, ethanol aqueous solution, tetraethyl orthosilicate and ammonia water is 1: (30-40): (0.7-0.9): (0.9-1.1).

3. The high flash point phenolic anticorrosive coating according to claim 1, characterized in that: The preparation method of the amino-modified hexagonal boron nitride comprises the following steps: dispersing hexagonal boron nitride in water, adding polyethyleneimine and epichlorohydrin, and carrying out stirring reaction; after the stirring reaction is completed, filtering, washing, and drying the reaction product to obtain the amino-modified hexagonal boron nitride.

4. The high flash point phenolic anticorrosive coating according to claim 1, characterized in that: The preparation method of the aminated hollow glass microspheres comprises the following steps: dispersing the hollow glass microspheres in water, adding polyethyleneimine and epichlorohydrin, and carrying out stirring reaction; and filtering, washing, and drying the reaction product after the stirring reaction is completed to obtain the aminated hollow glass microspheres.

5. The high flash point phenolic anticorrosive coating according to claim 1, characterized in that: The light stabilizer is a liquid hindered amine light stabilizer containing an amino ether group.

6. The method for preparing the high flash point phenolic anticorrosive coating according to any one of claims 1 to 5, characterized in that: The following steps are involved: Mix xylene phenolic resin, hyperbranched polyester modified phenolic resin, modified glass fiber, pigment, light stabilizer-β-cyclodextrin inclusion compound and solvent, stir, add silicone acrylic emulsion, mix evenly, continue stirring to obtain high flash point phenolic anti-corrosion coating.

7. Use of the high flash point phenolic anti-corrosion coating according to any one of claims 1 to 5 in the field of outdoor metal substrate protection.

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