Weather-resistant coating and preparation method thereof

Abstract

The invention discloses a weather-resistant coating and a preparation method thereof, comprising the following raw materials in parts by weight: 45-55 parts of hydroxyl-terminated polyester resin, 25-35 parts of modified acrylic resin, 1-2 parts of antioxidant, 8-10 parts of filler, 3-5 parts of curing agent, 0.5-0.8 parts of leveling agent, and 0.2-0.4 parts of stabilizer. The synthesized modified acrylic resin introduces functional monomers containing pyridine ring, ester group, and phosphate group to improve the antibacterial and anticorrosive properties of the coating. The synthesized antioxidant contains triazine ring, thioether group, hindered phenol structure, alcoholic hydroxyl group and fluorinated alkyl long chain in its molecule to improve the aging resistance and water resistance of the coating. The present invention obtains a coating with excellent weather resistance by improving the antibacterial, anticorrosive, aging resistance and water resistance of the coating.

Description

Technical Field

[0001] The invention relates to the field of coatings, and in particular to a weather-resistant coating and a preparation method thereof. Background Art

[0002] Bacterial contamination in paint affects the quality and service life of the paint. Bacteria can form a film layer on the surface of the paint, which affects the adhesion and waterproof performance of the paint. At the same time, they will degrade and acidify the organic matter in the paint, thereby accelerating the aging of the paint and causing the coating to become brittle and crack. When the coating surface is corroded by water, acids, alkalis and other harmful substances, the surface that should have been anti-corrosive will also become prone to rust, and the coating will also be prone to falling off and cracking. The polymers used in the paint will undergo irreversible reactions such as degradation under the action of light, heat, oxygen, etc., causing the coating to discolor, yellow, and powder. In severe cases, it will lead to reduced coating strength, cracking, blistering, cracking and falling off, reducing the protective performance of the paint and shortening its service life.

[0003] In summary, a suitable modification method is needed to improve the comprehensive properties of the coating, such as antibacterial, anticorrosive, waterproof and aging resistance, in order to obtain a coating with excellent weather resistance. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a weather-resistant coating and a preparation method thereof.

[0005] The purpose of the present invention can be achieved by the following technical solutions:

[0006] A weather-resistant coating, comprising the following raw materials in parts by weight: 45-55 parts of hydroxyl-terminated polyester resin, 25-35 parts of modified acrylic resin, 1-2 parts of antioxidant, 8-10 parts of filler, 3-5 parts of curing agent, 0.5-0.8 parts of leveling agent, and 0.2-0.4 parts of stabilizer;

[0007] The filler is carbon black and titanium dioxide in a mass ratio of 1:1; the curing agent is triglycidyl cyanurate; the leveling agent is acrylate; and the stabilizer is benzoin;

[0008] The modified acrylic resin is prepared by the following steps:

[0009] Step A1: Add ethyl 2-acetyl-4-pentanoate to dichloromethane, start stirring, then add 3-chloroperbenzoic acid, and stir at room temperature for 5-6 hours to obtain reaction product 1;

[0010] Further, the usage ratio of 2-acetyl-4-pentanoic acid ethyl ester, dichloromethane and 3-chloroperoxybenzoic acid is 0.1 mol: 90-110 mL: 0.1 mol;

[0011] During the reaction of step A1, 3-chloroperoxybenzoic acid oxidizes the carbon-carbon double bond in ethyl 2-acetyl-4-pentanoate into an epoxy group to obtain a reaction product 1;

[0012] Step A2: In a nitrogen atmosphere, add 2-pyridinecarboxylic acid and methanol into a round-bottom flask, start stirring, raise the temperature to 40-50° C., add pyridine and reaction product 1, and react with constant temperature stirring for 8-10 hours to obtain reaction product 2;

[0013] Further, the usage ratio of 2-pyridinecarboxylic acid, methanol, pyridine and reaction product 1 is 0.1 mol: 100-120 mL: 0.001-0.0012 mol: 0.1 mol;

[0014] During the reaction of step A2, the carboxyl group of 2-picolinic acid reacts with the epoxy group of the reaction product 1 to generate a reaction product 2 containing an alcoholic hydroxyl group;

[0015] Step A3: Add the reaction product 2 and diethyl chlorophosphate to chloroform, start reflux stirring, raise the temperature to 60°C, reflux stirring for reaction for 6-7h, and distill under reduced pressure to obtain the reaction product 3; in a nitrogen atmosphere, add the reaction product 3 and methylenetriphenylphosphine to anhydrous tetrahydrofuran, reflux stirring for reaction at 40-50°C for 3-4h to obtain the alkenyl-containing functional monomer;

[0016] Further, the amount ratio of the reaction product 2, diethyl chlorophosphate and chloroform is 0.1 mol: 0.1 mol: 100-110 mL; the amount ratio of the reaction product 3, methylenetriphenylphosphine and anhydrous tetrahydrofuran is 0.1 mol: 0.1 mol: 130-150 mL;

[0017] During the reaction of step A3, the alcoholic hydroxyl group of the reaction product 2 reacts with the phosphoryl chloride of diethyl chlorophosphate to generate a reaction product 3 containing a phosphate ester structure; the keto carbonyl group in the reaction product 3 reacts with methylene triphenylphosphine to generate a functional monomer containing an olefin group;

[0018] Step A4: mixing butyl acrylate, acrylic acid, styrene, methacrylic acid, hydroxyethyl acrylate and functional monomer at room temperature for 15-20 minutes to obtain a mixture; then mixing water, disodium lauryl polyoxyethylene ether sulfosuccinate and sodium 3-allyloxy-2-hydroxypropanesulfonate for 10-15 minutes to obtain a mixed solution; adding the mixed solution to the mixture and stirring for 30-40 minutes to obtain a pre-emulsified monomer; then adding water, disodium lauryl polyoxyethylene ether sulfosuccinate, sodium 3-allyloxy-2-hydroxypropanesulfonate and ammonium persulfate to a reaction bottle, heating to 70-80° C., adding 1 / 3 of the weight of the pre-emulsified monomer to the reaction bottle, and then reacting at a constant temperature for 20 minutes, and then slowly adding dropwise the remaining 2 / 3 of the weight of the pre-emulsified monomer and the initiator solution at 80-85° C., the addition is completed within 2 hours, and then reacting at a constant temperature for 1.5 hours, cooling to room temperature, and filtering with a 200-mesh sieve to obtain a modified acrylic resin;

[0019] Further, the amount ratio of butyl acrylate, acrylic acid, styrene, methacrylic acid, hydroxyethyl acrylate and functional monomer is 145g: 4g: 22g: 4g: 6g: 9g; the amount ratio of water, disodium lauryl polyoxyethylene ether sulfosuccinate, and sodium 3-allyloxy-2-hydroxypropanesulfonate is 70g: 1.8g: 0.8g; the amount ratio of water, disodium lauryl polyoxyethylene ether sulfosuccinate, sodium 3-allyloxy-2-hydroxypropanesulfonate, ammonium persulfate, pre-emulsified monomer and initiator solution is 100-110g: 0.35g: 1.2g: 0.4g: 72.6g: 6g; the initiator solution is obtained by adding 0.5-0.6g of ammonium persulfate to 5-6g of water and stirring and mixing, and the amount of pre-emulsified monomer is the total weight of the pre-emulsified monomer used;

[0020] In the reaction process of step A4, butyl acrylate, acrylic acid, styrene, methacrylic acid, hydroxyethyl acrylate and functional monomers are polymerized under the action of an initiator to obtain a modified acrylic resin;

[0021] The preparation of the antioxidant comprises the following steps:

[0022] Step B1: ethyl 2-[(4-amino-1,3,5-triazine-2-yl)thio]acetate, potassium carbonate and dimethyl sulfoxide are added into a flask to obtain a mixed solution 1, and then 3,5-bis(tert-butyl)-4-hydroxyphenylpropionyl chloride is added into dimethyl sulfoxide to obtain a mixed solution 2. The mixed solution 2 is slowly added dropwise into the mixed solution 1 in an ice-water bath at 0°C. After the addition is completed, the temperature is raised to 40°C, the reaction is carried out at a constant temperature for 8-10 hours, and distillation is performed under reduced pressure to obtain a reaction product a;

[0023] Further, the usage ratio of ethyl 2-[(4-amino-1,3,5-triazine-2-yl)thio]acetate, potassium carbonate and dimethyl sulfoxide is 0.1 mol: 0.010-0.015 mol: 80-90 mL; the usage ratio of 3,5-bis(tert-butyl)-4-hydroxyphenylpropionyl chloride and dimethyl sulfoxide is 0.1 mol: 55-65 mL;

[0024] During the reaction of step B1, the amino group of ethyl 2-[(4-amino-1,3,5-triazine-2-yl)thio]acetate reacts with 3,5-bis(tert-butyl)-4-hydroxyphenylpropionyl chloride to generate a reaction product a;

[0025] Step B2: Add the reaction product a and toluene to a tetrahydrofuran solution of lithium aluminum hydride, start stirring, and react at room temperature for 2-3 hours to obtain a reaction product b;

[0026] Further, the amount ratio of the reaction product a, toluene and the tetrahydrofuran solution of lithium aluminum hydride is 0.1 mol: 85-95 mL: 100-110 mL, and the concentration of the tetrahydrofuran solution of lithium aluminum hydride is 1 mol / L;

[0027] During the reaction of step B2, the carbon-oxygen double bond of the amide group and the ester group in the reaction product a are reduced to a methylene group and a primary alcohol, respectively, to obtain a reaction product b;

[0028] Step B3: Add perfluorohexylethylene to dichloromethane, start stirring, then add 3-chloroperoxybenzoic acid, and stir at room temperature for 4-5 hours to obtain reaction product c;

[0029] Further, the usage ratio of perfluorohexylethylene, dichloromethane and 3-chloroperoxybenzoic acid is 0.1 mol: 100-120 mL: 0.1 mol;

[0030] During the reaction of step B3, the carbon-carbon double bond in perfluorohexylethylene is oxidized to an epoxy group to obtain a reaction product c;

[0031] Step B4: Add the reaction product c and the reaction product b to isobutanol, start reflux stirring, raise the temperature to 90-100° C., reflux stirring at a constant temperature for 4-5 hours, distill under reduced pressure and dry to obtain an antioxidant;

[0032] Further, the usage ratio of reaction product c, reaction product b and isobutanol is 0.1 mol: 0.1 mol: 250-300 mL;

[0033] During the reaction of step B4, the epoxy group of the reaction product c reacts with the reaction product b to form an antioxidant;

[0034] The preparation of the weather-resistant coating comprises the following steps:

[0035] Add terminal hydroxy polyester resin, modified acrylic resin, antioxidant, filler, curing agent, leveling agent and stabilizer into a reaction kettle, stir at 150-160° C. for 30-40 minutes, and then extrude, tablet, crush and sieve through an extruder to obtain a weather-resistant coating.

[0036] Beneficial effects of the invention: The invention discloses a weather-resistant coating and a preparation method thereof, comprising the following raw materials: a hydroxyl-terminated polyester resin, a modified acrylic resin, an antioxidant, a filler, a curing agent, a leveling agent and a stabilizer. The synthesized modified acrylic resin is obtained by polymerization of butyl acrylate, acrylic acid, styrene, methacrylic acid, hydroxyethyl acrylate and a functional monomer, and the prepared functional monomer contains a pyridine ring, an ester group and a phosphate group in the molecular structure; the pyridine ring is a nitrogen-containing heterocyclic structure with 6 atoms, which has a high electron density and anti-nucleophilicity, and therefore has lipophilicity and electrophilicity, and can interact with biological molecules such as cell membranes and enzymes, thereby affecting the normal metabolic process of bacteria, causing bacterial death, and making the coating antibacterial; the phosphate group has a surface active function, so that after the coating contacts the metal surface, a stable, hard and dense coating will be formed, which enhances the adhesion of the coating and improves the anti-corrosion performance of the coating; the ester group structure is similar to the structure of the hydroxyl-terminated polyester resin, which increases the compatibility of the modified acrylic resin with the hydroxyl-terminated polyester resin matrix, making the coating more uniform.

[0037] The synthesized antioxidant contains a triazine ring, a thioether group, a hindered phenol structure, an alcoholic hydroxyl group and a fluorinated alkyl long chain in its molecule. After the triazine ring absorbs ultraviolet rays, the hydrogen bonds in the molecule are destroyed due to the chelate ring formed by the hydrogen bonds in the molecule, forming an unstable high-energy ionic compound, and then releasing excess energy to recover to the original low-energy stable state, thereby absorbing ultraviolet rays and making the coating have anti-ultraviolet properties. The hindered phenol structure reacts with peroxyl radicals in the oxidation reaction to generate hydroperoxides, so that the oxidation reaction is terminated, and the thioether group can reduce and decompose the hydroperoxides. The triazine ring, the hindered phenol structure and the thioether group work synergistically, so that the coating has excellent aging resistance. The alcoholic hydroxyl group can form a cross-linked network with active groups such as hydroxyl and carboxyl groups in terminal hydroxyl polyester resins and modified acrylic resins, thereby improving the dispersion and compatibility of the antioxidant in the matrix and avoiding the migration and failure of the antioxidant. The fluorinated alkyl long chain has strong hydrophobicity and low surface energy, so that the waterproof performance of the coating is improved. In summary, the present invention obtains a coating with excellent weather resistance by improving the antibacterial property, anticorrosion property, aging resistance and water resistance of the coating. DETAILED DESCRIPTION

[0038] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] Example 1

[0040] A modified acrylic resin, the preparation of which comprises the following steps:

[0041] Step A1: Add ethyl 2-acetyl-4-pentanoate to dichloromethane, start stirring, then add 3-chloroperbenzoic acid, and stir at room temperature for 5 hours to obtain reaction product 1; the amount ratio of ethyl 2-acetyl-4-pentanoate, dichloromethane and 3-chloroperbenzoic acid is 0.1 mol: 90 mL: 0.1 mol;

[0042] Step A2: In a nitrogen atmosphere, 2-pyridinecarboxylic acid and methanol were added to a round-bottom flask, stirring was started, the temperature was raised to 40° C., pyridine and reaction product 1 were added, and the reaction was stirred at a constant temperature for 8 h to obtain reaction product 2; the amount ratio of 2-pyridinecarboxylic acid, methanol, pyridine and reaction product 1 was 0.1 mol: 100 mL: 0.001 mol: 0.1 mol;

[0043] Step A3: Add the reaction product 2 and diethyl chlorophosphate to chloroform, start reflux stirring, heat to 60°C, reflux stirring for 6 hours, and distill under reduced pressure to obtain the reaction product 3; in a nitrogen atmosphere, add the reaction product 3 and methylene triphenyl phosphine to anhydrous tetrahydrofuran, reflux stirring for 3 hours at 40°C to obtain an olefin-containing functional monomer; the amount ratio of the reaction product 2, diethyl chlorophosphate and chloroform is 0.1 mol: 0.1 mol: 100 mL; the amount ratio of the reaction product 3, methylene triphenyl phosphine and anhydrous tetrahydrofuran is 0.1 mol: 0.1 mol: 130 mL;

[0044] Step A4: Mix butyl acrylate, acrylic acid, styrene, methacrylic acid, hydroxyethyl acrylate and functional monomer at room temperature for 15 minutes to obtain a mixture; then mix water, disodium lauryl polyoxyethylene ether sulfosuccinate and sodium 3-allyloxy-2-hydroxypropanesulfonate for 10 minutes to obtain a mixed solution; add the mixed solution to the mixture and stir for 30 minutes to obtain a pre-emulsified monomer; then add water, disodium lauryl polyoxyethylene ether sulfosuccinate, sodium 3-allyloxy-2-hydroxypropanesulfonate and ammonium persulfate to a reaction bottle, heat to 70°C, add 1 / 3 of the weight of the pre-emulsified monomer to the reaction bottle, and then react at a constant temperature for 20 minutes, and then slowly add the remaining 2 / 3 of the weight of the pre-emulsified monomer and the initiator solution at 80°C, and complete the addition within 2 hours, and then react at a constant temperature for 1.5 hours. The mixture was cooled to room temperature and filtered with a 200-mesh sieve to obtain a modified acrylic resin; the amount ratio of butyl acrylate, acrylic acid, styrene, methacrylic acid, hydroxyethyl acrylate and functional monomer was 145 g: 4 g: 22 g: 4 g: 6 g: 9 g; the amount ratio of water, disodium lauryl polyoxyethylene ether sulfosuccinate and sodium 3-allyloxy-2-hydroxypropanesulfonate was 70 g: 1.8 g: 0.8 g; the amount ratio of water, disodium lauryl polyoxyethylene ether sulfosuccinate, sodium 3-allyloxy-2-hydroxypropanesulfonate, ammonium persulfate, pre-emulsified monomer and initiator solution was 100 g: 0.35 g: 1.2 g: 0.4 g: 72.6 g: 6 g; the initiator solution was obtained by adding 0.5 g of ammonium persulfate to 5 g of water and stirring and mixing, and the amount of pre-emulsified monomer was the total weight of the pre-emulsified monomer used.

[0045] Example 2

[0046] A modified acrylic resin, the preparation of which comprises the following steps:

[0047] Step A1: Add ethyl 2-acetyl-4-pentanoate to dichloromethane, start stirring, then add 3-chloroperbenzoic acid, and stir at room temperature for 5.5 hours to obtain reaction product 1; the amount ratio of ethyl 2-acetyl-4-pentanoate, dichloromethane and 3-chloroperbenzoic acid is 0.1 mol: 100 mL: 0.1 mol;

[0048] Step A2: In a nitrogen atmosphere, 2-pyridinecarboxylic acid and methanol were added to a round-bottom flask, stirring was started, the temperature was raised to 45°C, pyridine and reaction product 1 were added, and the reaction was stirred at a constant temperature for 9 hours to obtain reaction product 2; the amount ratio of 2-pyridinecarboxylic acid, methanol, pyridine and reaction product 1 was 0.1 mol: 110 mL: 0.0011 mol: 0.1 mol;

[0049] Step A3: Add the reaction product 2 and diethyl chlorophosphate to chloroform, start reflux stirring, heat to 60°C, reflux stirring for 6.5 hours, and distill under reduced pressure to obtain the reaction product 3; in a nitrogen atmosphere, add the reaction product 3 and methylenetriphenylphosphine to anhydrous tetrahydrofuran, reflux stirring for 3.5 hours at 45°C to obtain an olefin-containing functional monomer; the amount ratio of the reaction product 2, diethyl chlorophosphate and chloroform is 0.1 mol: 0.1 mol: 105 mL; the amount ratio of the reaction product 3, methylenetriphenylphosphine and anhydrous tetrahydrofuran is 0.1 mol: 0.1 mol: 140 mL;

[0050] Step A4: Mix butyl acrylate, acrylic acid, styrene, methacrylic acid, hydroxyethyl acrylate and functional monomer at room temperature for 17 minutes to obtain a mixture; then mix water, disodium lauryl polyoxyethylene ether sulfosuccinate and sodium 3-allyloxy-2-hydroxypropanesulfonate for 12 minutes to obtain a mixed solution; add the mixed solution to the mixture and stir for 35 minutes to obtain a pre-emulsified monomer; then add water, disodium lauryl polyoxyethylene ether sulfosuccinate, sodium 3-allyloxy-2-hydroxypropanesulfonate and ammonium persulfate to a reaction bottle, heat to 75°C, add 1 / 3 of the weight of the pre-emulsified monomer to the reaction bottle, and then react at a constant temperature for 20 minutes, and then slowly add the remaining 2 / 3 of the weight of the pre-emulsified monomer and the initiator solution at 82°C, and complete the addition within 2 hours, and then react at a constant temperature for 1.5 hours, and then cool. The mixture was cooled to room temperature and filtered through a 200-mesh sieve to obtain a modified acrylic resin; the amount ratio of butyl acrylate, acrylic acid, styrene, methacrylic acid, hydroxyethyl acrylate and functional monomer was 145 g: 4 g: 22 g: 4 g: 6 g: 9 g; the amount ratio of water, disodium lauryl polyoxyethylene ether sulfosuccinate and sodium 3-allyloxy-2-hydroxypropanesulfonate was 70 g: 1.8 g: 0.8 g; the amount ratio of water, disodium lauryl polyoxyethylene ether sulfosuccinate, sodium 3-allyloxy-2-hydroxypropanesulfonate, ammonium persulfate, pre-emulsified monomer and initiator solution was 105 g: 0.35 g: 1.2 g: 0.4 g: 72.6 g: 6 g; the initiator solution was obtained by adding 0.55 g of ammonium persulfate to 5.5 g of water and stirring and mixing, and the amount of pre-emulsified monomer was the total weight of the pre-emulsified monomer used.

[0051] Example 3

[0052] A modified acrylic resin, the preparation of which comprises the following steps:

[0053] Step A1: Add ethyl 2-acetyl-4-pentanoate to dichloromethane, start stirring, then add 3-chloroperbenzoic acid, and stir at room temperature for 6 hours to obtain reaction product 1; the amount ratio of ethyl 2-acetyl-4-pentanoate, dichloromethane and 3-chloroperbenzoic acid is 0.1 mol: 110 mL: 0.1 mol;

[0054] Step A2: In a nitrogen atmosphere, 2-pyridinecarboxylic acid and methanol were added to a round-bottom flask, stirring was started, the temperature was raised to 50° C., pyridine and reaction product 1 were added, and the reaction was stirred at a constant temperature for 10 h to obtain reaction product 2; the amount ratio of 2-pyridinecarboxylic acid, methanol, pyridine and reaction product 1 was 0.1 mol: 120 mL: 0.0012 mol: 0.1 mol;

[0055] Step A3: Add the reaction product 2 and diethyl chlorophosphate to chloroform, start reflux stirring, heat to 60°C, reflux stirring for reaction for 7 hours, and distill under reduced pressure to obtain the reaction product 3; in a nitrogen atmosphere, add the reaction product 3 and methylene triphenyl phosphine to anhydrous tetrahydrofuran, reflux stirring for reaction at 50°C for 4 hours to obtain an olefin-containing functional monomer; the amount ratio of the reaction product 2, diethyl chlorophosphate and chloroform is 0.1 mol: 0.1 mol: 110 mL; the amount ratio of the reaction product 3, methylene triphenyl phosphine and anhydrous tetrahydrofuran is 0.1 mol: 0.1 mol: 150 mL;

[0056] Step A4: Mix butyl acrylate, acrylic acid, styrene, methacrylic acid, hydroxyethyl acrylate and functional monomer at room temperature for 20 minutes to obtain a mixture; then mix water, disodium lauryl polyoxyethylene ether sulfosuccinate and sodium 3-allyloxy-2-hydroxypropanesulfonate for 15 minutes to obtain a mixed solution; add the mixed solution to the mixture and stir for 40 minutes to obtain a pre-emulsified monomer; then add water, disodium lauryl polyoxyethylene ether sulfosuccinate, sodium 3-allyloxy-2-hydroxypropanesulfonate and ammonium persulfate to a reaction bottle, heat to 80°C, add 1 / 3 of the weight of the pre-emulsified monomer to the reaction bottle, and then react at a constant temperature for 20 minutes, and then slowly add the remaining 2 / 3 of the weight of the pre-emulsified monomer and the initiator solution at 85°C, and complete the addition within 2 hours, and then react at a constant temperature for 1.5 hours. The mixture was cooled to room temperature and filtered with a 200-mesh sieve to obtain a modified acrylic resin; the amount ratio of butyl acrylate, acrylic acid, styrene, methacrylic acid, hydroxyethyl acrylate and functional monomer was 145 g: 4 g: 22 g: 4 g: 6 g: 9 g; the amount ratio of water, disodium lauryl polyoxyethylene ether sulfosuccinate and sodium 3-allyloxy-2-hydroxypropanesulfonate was 70 g: 1.8 g: 0.8 g; the amount ratio of water, disodium lauryl polyoxyethylene ether sulfosuccinate, sodium 3-allyloxy-2-hydroxypropanesulfonate, ammonium persulfate, pre-emulsified monomer and initiator solution was 110 g: 0.35 g: 1.2 g: 0.4 g: 72.6 g: 6 g; the initiator solution was obtained by adding 0.6 g of ammonium persulfate to 6 g of water and stirring and mixing, and the amount of pre-emulsified monomer was the total weight of the pre-emulsified monomer used.

[0057] Example 4

[0058] An antioxidant, the preparation of which comprises the following steps:

[0059] Step B1: ethyl 2-[(4-amino-1,3,5-triazine-2-yl)thio]acetate, potassium carbonate and dimethyl sulfoxide are added into a flask to obtain a mixed solution 1, and then 3,5-bis(tert-butyl)-4-hydroxyphenylpropionyl chloride is added into dimethyl sulfoxide to obtain a mixed solution 2, and the mixed solution 2 is slowly added dropwise into the mixed solution 1 in an ice-water bath at 0°C. After the addition is complete, the mixture is heated to 40°C, reacted at this temperature for 8 hours, and distilled under reduced pressure to obtain a reaction product a; the amount ratio of ethyl 2-[(4-amino-1,3,5-triazine-2-yl)thio]acetate, potassium carbonate and dimethyl sulfoxide is 0.1 mol: 0.010 mol: 80 mL; the amount ratio of 3,5-bis(tert-butyl)-4-hydroxyphenylpropionyl chloride and dimethyl sulfoxide is 0.1 mol: 55 mL;

[0060] Step B2: adding the reaction product a and toluene to a tetrahydrofuran solution of lithium aluminum hydride, starting stirring, and stirring the mixture at room temperature for 2 hours to obtain a reaction product b; the amount ratio of the reaction product a, toluene and the tetrahydrofuran solution of lithium aluminum hydride is 0.1 mol: 85 mL: 100 mL, and the concentration of the tetrahydrofuran solution of lithium aluminum hydride is 1 mol / L;

[0061] Step B3: adding perfluorohexylethylene to dichloromethane, stirring, and then adding 3-chloroperoxybenzoic acid, stirring and reacting at room temperature for 4 hours to obtain reaction product c; the amount ratio of perfluorohexylethylene, dichloromethane and 3-chloroperoxybenzoic acid is 0.1 mol: 100 mL: 0.1 mol;

[0062] Step B4: Add reaction product c and reaction product b to isobutanol, start reflux stirring, raise the temperature to 90°C, reflux stirring and react at constant temperature for 4 hours, distill under reduced pressure and dry to obtain an antioxidant; the amount ratio of reaction product c, reaction product b and isobutanol is 0.1 mol: 0.1 mol: 250 mL.

[0063] Example 5

[0064] An antioxidant, the preparation of which comprises the following steps:

[0065] Step B1: ethyl 2-[(4-amino-1,3,5-triazine-2-yl)thio]acetate, potassium carbonate and dimethyl sulfoxide are added into a flask to obtain a mixed solution 1, and then 3,5-bis(tert-butyl)-4-hydroxyphenylpropionyl chloride is added into dimethyl sulfoxide to obtain a mixed solution 2, and the mixed solution 2 is slowly added dropwise into the mixed solution 1 in an ice-water bath at 0°C. After the addition is completed, the mixture is heated to 40°C, and the reaction is carried out at a constant temperature for 9 hours, and the mixture is distilled under reduced pressure to obtain a reaction product a; the amount ratio of ethyl 2-[(4-amino-1,3,5-triazine-2-yl)thio]acetate, potassium carbonate and dimethyl sulfoxide is 0.1 mol: 0.012 mol: 85 mL; the amount ratio of 3,5-bis(tert-butyl)-4-hydroxyphenylpropionyl chloride and dimethyl sulfoxide is 0.1 mol: 60 mL;

[0066] Step B2: adding the reaction product a and toluene to a tetrahydrofuran solution of lithium aluminum hydride, starting stirring, and reacting at room temperature for 2.5 hours to obtain a reaction product b; the amount ratio of the reaction product a, toluene and the tetrahydrofuran solution of lithium aluminum hydride is 0.1 mol: 90 mL: 105 mL, and the concentration of the tetrahydrofuran solution of lithium aluminum hydride is 1 mol / L;

[0067] Step B3: adding perfluorohexylethylene to dichloromethane, stirring, and then adding 3-chloroperoxybenzoic acid, stirring and reacting at room temperature for 4.5 hours to obtain reaction product c; the amount ratio of perfluorohexylethylene, dichloromethane and 3-chloroperoxybenzoic acid is 0.1 mol: 110 mL: 0.1 mol;

[0068] Step B4: Add reaction product c and reaction product b to isobutanol, start reflux stirring, raise the temperature to 95°C, reflux stirring and react at constant temperature for 4.5 hours, distill under reduced pressure and dry to obtain an antioxidant; the amount ratio of reaction product c, reaction product b and isobutanol is 0.1 mol: 0.1 mol: 270 mL.

[0069] Example 6

[0070] An antioxidant, the preparation of which comprises the following steps:

[0071] Step B1: ethyl 2-[(4-amino-1,3,5-triazine-2-yl)thio]acetate, potassium carbonate and dimethyl sulfoxide are added into a flask to obtain a mixed solution 1, and then 3,5-bis(tert-butyl)-4-hydroxyphenylpropionyl chloride is added into dimethyl sulfoxide to obtain a mixed solution 2, and the mixed solution 2 is slowly added dropwise into the mixed solution 1 in an ice-water bath at 0°C. After the addition is complete, the mixture is heated to 40°C, reacted at this temperature for 10 hours, and distilled under reduced pressure to obtain a reaction product a; the amount ratio of ethyl 2-[(4-amino-1,3,5-triazine-2-yl)thio]acetate, potassium carbonate and dimethyl sulfoxide is 0.1 mol: 0.015 mol: 90 mL; the amount ratio of 3,5-bis(tert-butyl)-4-hydroxyphenylpropionyl chloride and dimethyl sulfoxide is 0.1 mol: 65 mL;

[0072] Step B2: adding the reaction product a and toluene to a tetrahydrofuran solution of lithium aluminum hydride, starting stirring, and reacting at room temperature for 3 hours to obtain a reaction product b; the amount ratio of the reaction product a, toluene and the tetrahydrofuran solution of lithium aluminum hydride is 0.1 mol: 95 mL: 110 mL, and the concentration of the tetrahydrofuran solution of lithium aluminum hydride is 1 mol / L;

[0073] Step B3: adding perfluorohexylethylene to dichloromethane, stirring, and then adding 3-chloroperoxybenzoic acid, stirring and reacting at room temperature for 5 hours to obtain reaction product c; the amount ratio of perfluorohexylethylene, dichloromethane and 3-chloroperoxybenzoic acid is 0.1 mol: 120 mL: 0.1 mol;

[0074] Step B4: Add reaction product c and reaction product b to isobutanol, start reflux stirring, raise the temperature to 100°C, reflux stirring and react at constant temperature for 5 hours, distill under reduced pressure and dry to obtain an antioxidant; the dosage ratio of reaction product c, reaction product b and isobutanol is 0.1 mol: 0.1 mol: 300 mL.

[0075] Example 7

[0076] A weather-resistant coating, comprising the following raw materials in parts by weight: 45 parts of hydroxyl-terminated polyester resin, 25 parts of modified acrylic resin, 1 part of antioxidant, 8 parts of filler, 3 parts of curing agent, 0.5 parts of leveling agent, and 0.2 parts of stabilizer; the filler is carbon black and titanium dioxide prepared in a mass ratio of 1:1; the curing agent is triglycidyl cyanurate; the leveling agent is acrylic acid ester; and the stabilizer is benzoin;

[0077] The preparation of the weather-resistant coating comprises the following steps: adding the terminal hydroxy polyester resin, the modified acrylic resin obtained in Example 1, the antioxidant obtained in Example 4, the filler, the curing agent, the leveling agent and the stabilizer into a reaction kettle, stirring at 150° C. for 30 minutes, and then extruding, tableting, crushing and screening through an extruder to obtain the weather-resistant coating.

[0078] Example 8

[0079] A weather-resistant coating, comprising the following raw materials in parts by weight: 50 parts of hydroxyl-terminated polyester resin, 30 parts of modified acrylic resin, 1.5 parts of antioxidant, 9 parts of filler, 4 parts of curing agent, 0.7 parts of leveling agent, and 0.3 parts of stabilizer; the filler is carbon black and titanium dioxide prepared in a mass ratio of 1:1; the curing agent is triglycidyl cyanurate; the leveling agent is acrylic acid ester; and the stabilizer is benzoin;

[0080] The preparation of the weather-resistant coating comprises the following steps: adding the terminal hydroxy polyester resin, the modified acrylic resin obtained in Example 2, the antioxidant obtained in Example 5, the filler, the curing agent, the leveling agent and the stabilizer into a reaction kettle, stirring at 155° C. for 35 minutes, and then extruding through an extruder, tableting, crushing and screening to obtain the weather-resistant coating.

[0081] Example 9

[0082] A weather-resistant coating, comprising the following raw materials in parts by weight: 55 parts of hydroxyl-terminated polyester resin, 35 parts of modified acrylic resin, 2 parts of antioxidant, 10 parts of filler, 5 parts of curing agent, 0.8 parts of leveling agent, and 0.4 parts of stabilizer; the filler is carbon black and titanium dioxide prepared in a mass ratio of 1:1; the curing agent is triglycidyl cyanurate; the leveling agent is acrylate; and the stabilizer is benzoin;

[0083] The preparation of the weather-resistant coating comprises the following steps: adding the terminal hydroxy polyester resin, the modified acrylic resin obtained in Example 3, the antioxidant obtained in Example 6, the filler, the curing agent, the leveling agent and the stabilizer into a reaction kettle, stirring at 160° C. for 40 minutes, and then extruding through an extruder, tableting, crushing and screening to obtain the weather-resistant coating.

[0084] Comparative Example 1

[0085] This comparative example is a commercially available coating.

[0086] Comparative Example 2

[0087] Compared with Example 9, the modified acrylic resin is replaced with ordinary acrylic resin, and the rest is exactly the same as Example 9 to prepare a weather-resistant coating.

[0088] Comparative Example 3

[0089] Compared with Example 9, the antioxidant is replaced with ethyl 2-[(4-amino-1,3,5-triazine-2-yl)thio]acetate, which is reduced with lithium aluminum hydride and then reacted with the reaction product c by ring-opening reaction, i.e., no hindered phenol structure is introduced. The rest is exactly the same as Example 9 to obtain a weather-resistant coating.

[0090] Comparative Example 4

[0091] Compared with Example 9, the antioxidant is replaced with the reaction product b, that is, no fluorinated alkyl long chain is introduced, and the rest is exactly the same as Example 9 to prepare a weather-resistant coating.

[0092] The weather-resistant coating disclosed in the present invention is further tested for its effect, and the test results are as follows.

[0093] The coatings obtained in Examples 7-9 and Comparative Examples 1-3 were sprayed on standard test panels pretreated according to "GB / T 9271-2008 Standard Test Panels for Paints and Varnishes" to prepare test samples;

[0094] The waterproofness of the coating was determined according to GB / T1733-1993 "Determination of water resistance of paint film"; the antibacterial property was determined according to GB 21551.2-2010 standard; the salt spray resistance test method was to place the test sample in a salt spray test chamber, place the test sample at an angle of 25°, and then spray it at a spray volume of 10%, observe the surface of the sample after 168 hours and record the surface phenomenon; according to GB / T1865-2009 "Artificial weathering and artificial radiation exposure of paints and varnishes to filtered xenon arc radiation", the artificial aging test was carried out, the phenomenon was recorded, and the results were recorded in Table 1;

[0095] Table 1:

[0096]

[0097]

[0098] According to the data in Table 1, compared with Comparative Example 1, Examples 7, 8 and 9 show that the weather-resistant coating disclosed in the present invention has excellent water resistance, antibacterial property, corrosion resistance and aging resistance compared with commercially available coatings. Comparison between Example 9 and Comparative Example 2 shows that the pyridine ring and phosphate group are introduced into the modified acrylic resin, which improves the antibacterial and corrosion resistance of the coating. Comparison between Example 9 and Comparative Example 3 shows that the introduction of the hindered phenol structure, synergistically with the triazine ring and the thioether group, improves the aging resistance of the coating. Comparison between Example 9 and Comparative Example 3 shows that the introduction of a fluorinated alkyl long chain with strong hydrophobicity and low surface energy improves the water resistance of the coating. In summary, the weather-resistant coating disclosed in the present invention has excellent weather resistance.

[0099] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the concept of the invention or exceed the scope defined by the claims, they should all fall within the protection scope of the present invention.

Claims

1. A weather-resistant coating, characterized in that: The invention comprises the following raw materials in parts by weight: 45-55 parts of hydroxyl-terminated polyester resin, 25-35 parts of modified acrylic resin, 1-2 parts of antioxidant, 8-10 parts of filler, 3-5 parts of curing agent, 0.5-0.8 parts of leveling agent and 0.2-0.4 parts of stabilizer; The modified acrylic resin is prepared by the following steps: Step A1: Add ethyl 2-acetyl-4-pentanoate to dichloromethane, start stirring, then add 3-chloroperbenzoic acid, and stir at room temperature for 5-6 hours to obtain reaction product 1; Step A2: In a nitrogen atmosphere, add 2-pyridinecarboxylic acid and methanol into a round-bottom flask, start stirring, raise the temperature to 40-50° C., add pyridine and reaction product 1, and react with constant temperature stirring for 8-10 hours to obtain reaction product 2; Step A3: Add the reaction product 2 and diethyl chlorophosphate to chloroform, start reflux stirring, raise the temperature to 60°C, reflux stirring for reaction for 6-7h, and distill under reduced pressure to obtain the reaction product 3; in a nitrogen atmosphere, add the reaction product 3 and methylenetriphenylphosphine to anhydrous tetrahydrofuran, reflux stirring for reaction at 40-50°C for 3-4h to obtain the alkenyl-containing functional monomer; Step A4: mixing butyl acrylate, acrylic acid, styrene, methacrylic acid, hydroxyethyl acrylate and functional monomer at room temperature for 15-20 minutes to obtain a mixture; then mixing water, disodium lauryl polyoxyethylene ether sulfosuccinate and sodium 3-allyloxy-2-hydroxypropanesulfonate for 10-15 minutes to obtain a mixed solution; adding the mixed solution to the mixture and stirring for 30-40 minutes to obtain a pre-emulsified monomer; then adding water, disodium lauryl polyoxyethylene ether sulfosuccinate, sodium 3-allyloxy-2-hydroxypropanesulfonate and ammonium persulfate to a reaction bottle, heating to 70-80° C., adding 1 / 3 of the weight of the pre-emulsified monomer to the reaction bottle, and then reacting at a constant temperature for 20 minutes, and then slowly adding dropwise the remaining 2 / 3 of the weight of the pre-emulsified monomer and the initiator solution at 80-85° C., the addition is completed within 2 hours, and then reacting at a constant temperature for 1.5 hours, cooling to room temperature, and filtering with a 200-mesh sieve to obtain a modified acrylic resin; The preparation of the antioxidant comprises the following steps: Step B1: ethyl 2-[(4-amino-1,3,5-triazine-2-yl)thio]acetate, potassium carbonate and dimethyl sulfoxide are added into a flask to obtain a mixed solution 1, and then 3,5-bis(tert-butyl)-4-hydroxyphenylpropionyl chloride is added into dimethyl sulfoxide to obtain a mixed solution 2. The mixed solution 2 is slowly added dropwise into the mixed solution 1 in an ice-water bath at 0°C. After the addition is completed, the temperature is raised to 40°C, the reaction is carried out at a constant temperature for 8-10 hours, and the reaction is distilled under reduced pressure to obtain a reaction product a; Step B2: Add the reaction product a and toluene to a tetrahydrofuran solution of lithium aluminum hydride, start stirring, and react at room temperature for 2-3 hours to obtain a reaction product b; Step B3: Add perfluorohexylethylene to dichloromethane, start stirring, then add 3-chloroperoxybenzoic acid, and stir at room temperature for 4-5 hours to obtain reaction product c; Step B4: Add the reaction product c and the reaction product b to isobutanol, start reflux stirring, raise the temperature to 90-100° C., reflux stirring at a constant temperature for 4-5 hours, distill under reduced pressure and dry to obtain an antioxidant.

2. A weather-resistant coating according to claim 1, characterized in that: The filler is carbon black and titanium dioxide in a mass ratio of 1:1, the curing agent is triglycidyl cyanurate, the leveling agent is acrylate, and the stabilizer is benzoin.

3. A weather-resistant coating according to claim 1, characterized in that: In step A1, the usage ratio of 2-acetyl-4-pentanoic acid ethyl ester, dichloromethane and 3-chloroperbenzoic acid is 0.1 mol:90-110 mL:0.1 mol.

4. A weather-resistant coating according to claim 1, characterized in that: In step A2, the usage ratio of 2-picolinic acid, methanol, pyridine and reaction product 1 is 0.1 mol: 100-120 mL: 0.001-0.0012 mol: 0.1 mol.

5. A weather-resistant coating according to claim 1, characterized in that: In step A3, the amount ratio of reaction product 2, diethyl chlorophosphate and chloroform is 0.1 mol: 0.1 mol: 100-110 mL; the amount ratio of reaction product 3, methylenetriphenylphosphine and anhydrous tetrahydrofuran is 0.1 mol: 0.1 mol: 130-150 mL.

6. A weather-resistant coating according to claim 1, characterized in that: In step A4, the usage ratio of butyl acrylate, acrylic acid, styrene, methacrylic acid, hydroxyethyl acrylate and functional monomer is 145g:4g:22g:4g:6g:9g; The amount ratio of water, disodium lauryl polyoxyethylene ether sulfosuccinate and sodium 3-allyloxy-2-hydroxypropane sulfonate is 70g:1.8g:0.8g; the amount ratio of water, disodium lauryl polyoxyethylene ether sulfosuccinate, sodium 3-allyloxy-2-hydroxypropane sulfonate, ammonium persulfate, pre-emulsified monomer and initiator solution is 100-110g:0.35g:1.2g:0.4g:72.6g:6g; the initiator solution is obtained by adding 0.5-0.6g of ammonium persulfate into 5-6g of water and stirring and mixing; the amount of pre-emulsified monomer is the total weight of the pre-emulsified monomer used.

7. A weather-resistant coating according to claim 1, characterized in that: In step B1, the usage ratio of ethyl 2-[(4-amino-1,3,5-triazine-2-yl)thio]acetate, potassium carbonate and dimethyl sulfoxide is 0.1 mol: 0.010-0.015 mol: 80-90 mL; the usage ratio of 3,5-bis(tert-butyl)-4-hydroxyphenylpropionyl chloride and dimethyl sulfoxide is 0.1 mol: 55-65 mL; in step B2, the usage ratio of reaction product a, toluene and tetrahydrofuran solution of lithium aluminum hydride is 0.1 mol: 85-95 mL: 100-110 mL, and the concentration of the tetrahydrofuran solution of lithium aluminum hydride is 1 mol / L.

8. The weather-resistant coating according to claim 1, characterized in that: In step B3, the usage ratio of perfluorohexylethylene, dichloromethane and 3-chloroperbenzoic acid is 0.1 mol: 100-120 mL: 0.1 mol; in step B4, the usage ratio of reaction product c, reaction product b and isobutanol is 0.1 mol: 0.1 mol: 250-300 mL.

9. The method for preparing a weather-resistant coating according to claim 1, characterized in that: The steps include: Add terminal hydroxy polyester resin, modified acrylic resin, antioxidant, filler, curing agent, leveling agent and stabilizer into a reaction kettle, stir at 150-160° C. for 30-40 minutes, and then extrude, tablet, crush and sieve through an extruder to obtain a weather-resistant coating.

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