Anti-fouling self-cleaning powder coating and preparation method thereof

Abstract

The invention provides an anti-fouling self-cleaning powder coating and a preparation method thereof, and belongs to the technical field of powder coatings. The preparation method comprises the following steps: mixing the modified resin, the modified filler, the curing agent, the antioxidant, the flatting agent and the dispersing agent, and sequentially performing melt extrusion, tabletting, crushing and screening to obtain the anti-fouling self-cleaning powder coating. Structures such as a silane group, tert-butylphenyl and adamantane provide low surface energy to form a hydrophobic substrate, a multistage micro-nano coarse structure of the pretreated pollen provides a morphology basis for a super-hydrophobic surface, and after grafting treatment of hydrophobic groups of 1-adamantanol and hexamethylene diisocyanate, the hydrophobicity of the pretreated pollen is enhanced, so that the super-hydrophobic surface is formed. All the materials cooperate with one another to construct a'micro-nano binary structure 'similar to a lotus leaf, a super-hydrophobic surface is formed, pollutant attachment is reduced, and therefore the efficient anti-pollution self-cleaning effect is achieved.

Description

Technical Field

[0001] The invention relates to the technical field of powder coatings, and in particular to an anti-fouling self-cleaning powder coating and a preparation method thereof. Background Art

[0002] Powder coating is a solid powdered synthetic resin coating composed of solid resin, pigment, filler and additives. Its dispersion medium is not solvent and water, but air. It has the characteristics of no solvent pollution, 100% film formation and low energy consumption. Powder coating is completely different from general coatings. It exists in the state of fine powder. Because it does not use solvent, it is called powder coating.

[0003] As air pollution and dust pollution become increasingly serious, surface coatings in contact with air are suffering from increasingly serious erosion. Such coating surfaces must be cleaned to ensure the cleanliness of the coating surface, but it will consume a lot of manpower and material resources; at the same time, multiple cleaning processes will affect the surface properties of the coating. For example, multiple cleanings will reduce the coating's flatness, glossiness, adhesion and other effects. Some super-hydrophobic coatings rely on fluorine-containing compounds to reduce surface energy, but fluorine elements may cause long-term pollution to the environment, and volatile toxic gases may be released during high-temperature curing. In addition, when preparing self-cleaning powder coatings, adding ingredients such as inorganic particles can increase the self-cleaning performance of powder coatings, but inorganic fillers have poor compatibility with resin matrices, making it difficult to balance excellent self-cleaning performance and impact resistance.

[0004] Chinese patent CN 114085604B discloses a high temperature resistant self-cleaning coating and a preparation method thereof, wherein polytetrafluoroethylene resin is used as a low surface energy material and modified nano-silicon dioxide is added, which can reduce the surface tension of the coating after coating, so that the coating has super-hydrophobic and self-cleaning properties. However, the polytetrafluoroethylene resin in the coating is difficult to degrade in the natural environment, which may pose a potential threat to the ecological environment and human health; Chinese patent CN 111234642B discloses a two-component hydrophobic coating, wherein the surface of the fabric treated with the two-component super-hydrophobic coating has super-hydrophobic properties, which meets the material's requirements for hydrophobicity and self-cleaning. However, a large amount of inorganic hydrophobic fillers are added during the preparation process, which may affect the impact resistance of the coating.

[0005] Therefore, providing a fluorine-free anti-fouling self-cleaning powder coating with good self-cleaning effect and impact resistance is an important problem to be solved in the art. Summary of the invention

[0006] In order to solve the problems existing in the prior art, the present invention provides an anti-fouling self-cleaning powder coating and a preparation method thereof. Specifically, the technical solution of the present invention includes the following contents:

[0007] A preparation method of an anti-fouling and self-cleaning powder coating, the preparation method comprising the following steps:

[0008] After mixing a modified resin, a modified filler, a curing agent, an antioxidant, a leveling agent and a dispersant, the anti-fouling and self-cleaning powder coating is prepared by successively performing melt extrusion, tablet pressing, crushing and screening.

[0009] Further, the preparation method of the modified resin comprises the following steps:

[0010] Lilial reacts with ethylenediamine to obtain intermediate A, and intermediate A reacts with epichlorohydrin to obtain intermediate B; phthalic anhydride, ethylene glycol and p-toluenesulfonic acid react to obtain a mixture, and the mixture, intermediate B, epoxy silane and triphenylphosphine react to obtain the modified resin.

[0011] Further, the preparation method of the modified filler comprises the following steps:

[0012] Sunflower pollen is successively treated with deionized water, acetone and ether to obtain pretreated pollen, and the pretreated pollen, 1-adamantanol, hexamethylene diisocyanate and dibutyltin dilaurate react to obtain the modified filler.

[0013] Further, the weight ratio of the lilial to the ethylenediamine is 15-25:6-10.

[0014] Further, the reaction conditions of the lilial and the ethylenediamine include a reaction temperature of 80-110 °C and a reaction time of 3-5 h.

[0015] Further, the weight ratio of the intermediate A to the epichlorohydrin is 5-15:2-5.

[0016] Further, the reaction conditions of the intermediate A and the epichlorohydrin include a reaction temperature of 75-85 °C and a reaction time of 5-6 h.

[0017] Further, the weight ratio of the phthalic anhydride, ethylene glycol, intermediate B and epoxy silane is 50-100:10-30:13-16:11-13.

[0018] Further, the epoxy silane is diethoxymethyl[(3-epoxyethanylmethoxy)propyl]silane.

[0019] Further, the weight ratio of the p-toluenesulfonic acid to the phthalic anhydride is 0.7-1.4:50-100.

[0020] Further, the weight ratio of the triphenylphosphine to the intermediate is 0.25-0.30:13-16.

[0021] Further, the reaction conditions of phthalic anhydride, ethylene glycol and p-toluenesulfonic acid include a reaction temperature of 110 - 130 °C and a reaction time of 4 - 6 h.

[0022] Further, the reaction conditions of the mixture, intermediate B, epoxy silane and triphenylphosphine include a reaction temperature of 105 - 115 °C and a reaction time of 3 - 5 h.

[0023] Further, the conditions for deionized water treatment include a treatment temperature of 50 - 60 °C and a treatment time of 2 - 3 h.

[0024] Further, the conditions for acetone treatment include a treatment temperature of 24 - 26 °C and a treatment time of 3 - 4 h.

[0025] Further, the conditions for ether treatment include a treatment temperature of 24 - 26 °C and a treatment time of 8 - 12 h.

[0026] Further, the weight ratio of the pretreated pollen, 1-adamantanol, and hexamethylene diisocyanate is 10 - 20:8 - 12:9 - 13.

[0027] Further, the weight ratio of dibutyltin dilaurate and hexamethylene diisocyanate is 0.25 - 0.45:9 - 13.

[0028] Further, the reaction conditions of the pretreated pollen, 1-adamantanol, hexamethylene diisocyanate and dibutyltin dilaurate include a reaction temperature of 50 - 60 °C and a reaction time of 12 - 18 h.

[0029] Further, the curing agent includes isophorone diisocyanate or diphenylmethane diisocyanate.

[0030] Further, the antioxidant includes 2,6-di-tert-butyl-p-cresol or antioxidant 3010.

[0031] Further, the leveling agent includes carboxymethyl cellulose or hydroxyethyl cellulose.

[0032] Further, the dispersant includes BYK-110 or BYK-P105.

[0033] Further, the conditions for mixing include a mixing temperature of 90 - 110 °C and a mixing time of 10 - 20 min.

[0034] Further, the conditions for melt extrusion include melt extrusion temperatures of 80 - 100 °C in zone 1, 120 - 140 °C in zone 2, 140 - 160 °C in zone 3, and 160 - 180 °C in zone 4.

[0035] Further, the sieve mesh for screening is 300 - 500 meshes.

[0036] Furthermore, the weight ratio of the modified resin, modified filler, curing agent, antioxidant, leveling agent and dispersant is 50-80:15-25:5-10:2-4:1.5-2.5:1.5-2.5.

[0037] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0038] (1) In the present invention, linalool and ethylenediamine react through Schiff base reaction to obtain intermediate A, intermediate A and epichlorohydrin react through substitution reaction to obtain intermediate B, phthalic anhydride and ethylene glycol react through esterification reaction to obtain a mixture, and the mixture, intermediate B and diethoxymethyl[(3-epoxyethanylmethoxy)propyl]silane are prepared into a modified resin through epoxy ring-opening reaction; sunflower pollen is successively treated with deionized water, acetone and ether to obtain pretreated pollen, and the pretreated pollen, 1-adamantanol and hexamethylene diisocyanate are prepared into a modified filler through nucleophilic addition reaction

[0039] (2) In the present invention, structures such as silyl groups, tert-butylphenyl and adamantane provide low surface energy to form a hydrophobic substrate, and the multi-level micro-nano rough structure of the pretreated pollen itself provides a morphological basis for the superhydrophobic surface. After grafting treatment with hydrophobic groups of 1-adamantanol and hexamethylene diisocyanate, the hydrophobicity of the pretreated pollen is enhanced, and the materials cooperate with each other to construct a "micro-nano binary structure" similar to that of a lotus leaf, forming a superhydrophobic surface to reduce pollutant attachment, thereby achieving an efficient anti-fouling and self-cleaning effect.

[0040] (3) In the present invention, the flexible chain segments in the modified resin provide flexibility, and the rigidity of the aromatic ring hinders crack propagation; the polyurethane formed by the pretreated pollen, 1-adamantanol and hexamethylene diisocyanate in the modified filler can interact with the modified resin. The cage structure of adamantane can not only provide rigid support, but also inhibit filler aggregation, ensure uniform dispersion, and avoid local stress concentration. The multiple effects cooperate with each other to make the powder coating have good impact resistance.

[0041] (4) The anti-fouling and self-cleaning powder coating provided by the present invention does not contain fluorides, avoiding the potential bioaccumulation and health risks of traditional fluorinated coatings. Specific Embodiments

[0042] The technical solutions of the present invention will be clearly and completely described below through the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present invention.

[0043] Unless otherwise specified, the raw materials and reagents used in the present invention below are all commercially available products or can be prepared by known methods.

[0044] Preparation Example 1:

[0045] A method for preparing a modified resin, comprising the following steps:

[0046] 15 parts by weight of linalool and 6 parts by weight of ethylenediamine are dispersed in 500 parts by weight of methanol. After adjusting the pH to 7, the mixture is stirred and reacted at 80 °C for 3 h in a nitrogen protection environment. After the reaction is completed, the intermediate product A is obtained by filtration, washing, and recrystallization in sequence; 5 parts by weight of intermediate product A and 2 parts by weight of epichlorohydrin are dispersed in 200 parts by weight of N,N-dimethylformamide. After adjusting the pH to 8, the mixture is stirred and reacted at 75 °C for 5 h in a nitrogen protection environment. After the reaction is completed, the intermediate product B is obtained by recrystallization, filtration, washing, and drying in sequence; 50 parts by weight of phthalic anhydride, 10 parts by weight of ethylene glycol, and 0.7 part by weight of p-toluenesulfonic acid are dispersed in 800 parts by weight of toluene. The mixture is stirred and reacted at 110 °C for 4 - 6 h in a nitrogen protection environment to obtain a mixture, and then 13 parts by weight of intermediate product B, 11 parts by weight of diethoxymethyl[(3-epoxyethanylmethoxy)propyl]silane, and 0.25 part by weight of triphenylphosphine are added. The mixture is stirred and reacted at 105 °C for 3 h in a nitrogen protection environment. After the reaction is completed, the modified resin is obtained by vacuum distillation, drying, and pulverization in sequence.

[0047] Preparation Example 2:

[0048] A method for preparing a modified resin, comprising the following steps:

[0049] 18 parts by weight of linalool and 8 parts by weight of ethylenediamine are dispersed in 500 parts by weight of methanol. After adjusting the pH to 7.5, the mixture is stirred and reacted at 90 °C for 3.5 h in a nitrogen protection environment. After the reaction is completed, the intermediate product A is obtained by filtration, washing, and recrystallization in sequence; 8 parts by weight of intermediate product A and 3 parts by weight of epichlorohydrin are dispersed in 200 parts by weight of N,N-dimethylformamide. After adjusting the pH to 8.5, the mixture is stirred and reacted at 77 °C for 5.2 h in a nitrogen protection environment. After the reaction is completed, the intermediate product B is obtained by recrystallization, filtration, washing, and drying in sequence; 70 parts by weight of phthalic anhydride, 15 parts by weight of ethylene glycol, and 0.9 part by weight of p-toluenesulfonic acid are dispersed in 800 parts by weight of toluene. The mixture is stirred and reacted at 115 °C for 4.5 h in a nitrogen protection environment to obtain a mixture, and then 14 parts by weight of intermediate product B, 11.5 parts by weight of diethoxymethyl[(3-epoxyethanylmethoxy)propyl]silane, and 0.26 part by weight of triphenylphosphine are added. The mixture is stirred and reacted at 109 °C for 3.5 h in a nitrogen protection environment. After the reaction is completed, the modified resin is obtained by vacuum distillation, drying, and pulverization in sequence.

[0050] Preparation Example 3:

[0051] Preparation method of modified resin, comprising the following steps:

[0052] 22 parts by weight of linalool and 9 parts by weight of ethylenediamine are dispersed in 500 parts by weight of methanol. After adjusting the pH to 7.5, the mixture is stirred and reacted at 100 °C for 4 h in a nitrogen protection environment. After the reaction, the intermediate product A is obtained successively by suction filtration, washing and recrystallization; 12 parts by weight of intermediate product A and 4 parts by weight of epichlorohydrin are dispersed in 200 parts by weight of N,N-dimethylformamide. After adjusting the pH to 9, the mixture is stirred and reacted at 82 °C for 5.7 h in a nitrogen protection environment. After the reaction, the intermediate product B is obtained successively by recrystallization, filtration, washing and drying; 90 parts by weight of phthalic anhydride, 20 parts by weight of ethylene glycol and 1.2 parts by weight of p-toluenesulfonic acid are dispersed in 800 parts by weight of toluene. The mixture is stirred and reacted at 125 °C for 5 h in a nitrogen protection environment. Then, 15 parts by weight of intermediate product B, 12 parts by weight of diethoxymethyl[(3-epoxyethanylmethoxy)propyl]silane and 0.28 parts by weight of triphenylphosphine are added. The mixture is stirred and reacted at 113 °C for 4 h in a nitrogen protection environment. After the reaction, the modified resin is obtained successively by vacuum distillation, drying and pulverization.

[0053] Preparation Example 4:

[0054] Preparation method of modified resin, comprising the following steps:

[0055] 25 parts by weight of linalool and 10 parts by weight of ethylenediamine are dispersed in 500 parts by weight of methanol. After adjusting the pH to 8, the mixture is stirred and reacted at 110 °C for 5 h in a nitrogen protection environment. After the reaction, the intermediate product A is obtained successively by suction filtration, washing and recrystallization; 15 parts by weight of intermediate product A and 5 parts by weight of epichlorohydrin are dispersed in 200 parts by weight of N,N-dimethylformamide. After adjusting the pH to 10, the mixture is stirred and reacted at 85 °C for 6 h in a nitrogen protection environment. After the reaction, the intermediate product B is obtained successively by recrystallization, filtration, washing and drying; 100 parts by weight of phthalic anhydride, 30 parts by weight of ethylene glycol and 1.4 parts by weight of p-toluenesulfonic acid are dispersed in 800 parts by weight of toluene. The mixture is stirred and reacted at 130 °C for 6 h in a nitrogen protection environment. Then, 16 parts by weight of intermediate product B, 13 parts by weight of diethoxymethyl[(3-epoxyethanylmethoxy)propyl]silane and 0.30 parts by weight of triphenylphosphine are added. The mixture is stirred and reacted at 115 °C for 5 h in a nitrogen protection environment. After the reaction, the modified resin is obtained successively by vacuum distillation, drying and pulverization.

[0056] Preparation Example 5:

[0057] Preparation method of modified resin, comprising the following steps:

[0058] 100 parts by weight of phthalic anhydride, 30 parts by weight of ethylene glycol, and 1.4 parts by weight of p-toluenesulfonic acid are dispersed in 800 parts by weight of toluene, and stirred and reacted at 130 °C for 6 h in a nitrogen protection environment to obtain a mixture. Then, 13 parts by weight of diethoxymethyl[(3-epoxyethanylmethoxy)propyl]silane and 0.15 parts by weight of triphenylphosphine are added, and stirred and reacted at 115 °C for 5 h in a nitrogen protection environment. After the reaction, the modified resin is obtained by vacuum distillation, drying, and pulverization in sequence.

[0059] Preparation Example 6:

[0060] A method for preparing a modified resin, comprising the following steps:

[0061] 25 parts by weight of lily aldehyde and 10 parts by weight of ethylenediamine are dispersed in 500 parts by weight of methanol. After adjusting the pH to 8, it is stirred and reacted at 110 °C for 5 h in a nitrogen protection environment. After the reaction, intermediate product A is obtained by suction filtration, washing, and recrystallization in sequence; 15 parts by weight of intermediate product A and 5 parts by weight of epichlorohydrin are dispersed in 200 parts by weight of N,N-dimethylformamide. After adjusting the pH to 10, it is stirred and reacted at 85 °C for 6 h in a nitrogen protection environment. After the reaction, intermediate product B is obtained by recrystallization, filtration, washing, and drying in sequence; 100 parts by weight of phthalic anhydride, 30 parts by weight of ethylene glycol, and 1.4 parts by weight of p-toluenesulfonic acid are dispersed in 800 parts by weight of toluene, and stirred and reacted at 130 °C for 6 h in a nitrogen protection environment to obtain a mixture. Then, 16 parts by weight of intermediate product B and 0.17 parts by weight of triphenylphosphine are added, and stirred and reacted at 115 °C for 5 h in a nitrogen protection environment. After the reaction, the modified resin is obtained by vacuum distillation, drying, and pulverization in sequence.

[0062] Preparation Example 7:

[0063] A method for preparing a modified filler comprises the following steps:

[0064] 50 parts by weight of sunflower pollen are dispersed in 100 parts by weight of deionized water, stirred at 50 °C at a rotation speed of 900 r / min for 2 h, then filtered to remove impurities, and then the water is removed by suction filtration to obtain pollen grains. The obtained pollen grains are dispersed in 100 parts by weight of acetone, stirred at 24 °C at a rotation speed of 900 r / min for 3 h, and then subjected to suction filtration and washing in sequence to obtain a solid powder. The obtained solid powder is dispersed in 100 parts by weight of ether, stirred at 24 °C at a rotation speed of 900 r / min for 8 h, and then subjected to suction filtration, washing, and vacuum drying in sequence to obtain pretreated pollen; 10 parts by weight of pretreated pollen and 8 parts by weight of 1-adamantanol are dispersed in 200 parts by weight of N,N-dimethylformamide. In a nitrogen protection environment, 9 parts by weight of hexamethylene diisocyanate and 0.25 parts by weight of dibutyltin dilaurate are added, and stirred and reacted at 50 °C for 12 h. After the reaction, the modified filler is obtained by centrifugal washing and vacuum drying in sequence.

[0065] Preparation Example 8:

[0066] The preparation method of the modified filler comprises the following steps:

[0067] 50 parts by weight of sunflower pollen are dispersed in 100 parts by weight of deionized water, stirred at 52 °C at a rotation speed of 950 r / min for 2.2 h, then filtered to remove impurities, and then the water is removed by suction filtration to obtain pollen grains. The obtained pollen grains are dispersed in 100 parts by weight of acetone, stirred at 25 °C at a rotation speed of 950 r / min for 3.2 h, and then successively subjected to suction filtration and washing to obtain a solid powder. The obtained solid powder is dispersed in 100 parts by weight of ether, stirred at 25 °C at a rotation speed of 950 r / min for 9 h, and then successively subjected to suction filtration, washing and vacuum drying to obtain pretreated pollen; 13 parts by weight of pretreated pollen and 9 parts by weight of 1-adamantanol are dispersed in 200 parts by weight of N,N-dimethylformamide, 10 parts by weight of hexamethylene diisocyanate and 0.3 part by weight of dibutyltin dilaurate are added in a nitrogen protection environment, and the mixture is stirred and reacted at 52 °C for 14 h. After the reaction is completed, the product is successively subjected to centrifugal washing and vacuum drying to obtain the modified filler.

[0068] Preparation Example 9:

[0069] The preparation method of the modified filler comprises the following steps:

[0070] 50 parts by weight of sunflower pollen are dispersed in 100 parts by weight of deionized water, stirred at 56 °C at a rotation speed of 1000 r / min for 2.8 h, then filtered to remove impurities, and then the water is removed by suction filtration to obtain pollen grains. The obtained pollen grains are dispersed in 100 parts by weight of acetone, stirred at 26 °C at a rotation speed of 1000 r / min for 3.7 h, and then successively subjected to suction filtration and washing to obtain a solid powder. The obtained solid powder is dispersed in 100 parts by weight of ether, stirred at 24 °C at a rotation speed of 1000 r / min for 10 h, and then successively subjected to suction filtration, washing and vacuum drying to obtain pretreated pollen; 16 parts by weight of pretreated pollen and 10.5 parts by weight of 1-adamantanol are dispersed in 200 parts by weight of N,N-dimethylformamide, 11 parts by weight of hexamethylene diisocyanate and 0.4 part by weight of dibutyltin dilaurate are added in a nitrogen protection environment, and the mixture is stirred and reacted at 57 °C for 16 h. After the reaction is completed, the product is successively subjected to centrifugal washing and vacuum drying to obtain the modified filler.

[0071] Preparation Example 10:

[0072] The preparation method of the modified filler comprises the following steps:

[0073] 50 parts by weight of sunflower pollen are dispersed in 100 parts by weight of deionized water, stirred at a speed of 1100 r / min at 60 °C for 3 h, then filtered to remove impurities, and then the water is removed by suction filtration to obtain pollen grains. The obtained pollen grains are dispersed in 100 parts by weight of acetone, stirred at a speed of 1100 r / min at 26 °C for 4 h, and then successively subjected to suction filtration and washing to obtain a solid powder. The obtained solid powder is dispersed in 100 parts by weight of ether, stirred at a speed of 1100 r / min at 26 °C for 12 h, and then successively subjected to suction filtration, washing and vacuum drying to obtain pretreated pollen; 20 parts by weight of pretreated pollen and 12 parts by weight of 1-adamantanol are dispersed in 200 parts by weight of N,N-dimethylformamide, 13 parts by weight of hexamethylene diisocyanate and 0.45 parts by weight of dibutyltin dilaurate are added in a nitrogen protection environment, and the mixture is stirred and reacted at 60 °C for 18 h. After the reaction is completed, the product is successively subjected to centrifugal washing and vacuum drying to obtain a modified filler.

[0074] Preparation Example 11:

[0075] The preparation method of the modified filler comprises the following steps:

[0076] 50 parts by weight of sunflower pollen are dispersed in 100 parts by weight of deionized water, stirred at a speed of 1100 r / min at 60 °C for 3 h, then filtered to remove impurities, and then the water is removed by suction filtration to obtain pollen grains. The obtained pollen grains are dispersed in 100 parts by weight of acetone, stirred at a speed of 1100 r / min at 26 °C for 4 h, and then successively subjected to suction filtration and washing to obtain a solid powder. The obtained solid powder is dispersed in 100 parts by weight of ether, stirred at a speed of 1100 r / min at 26 °C for 12 h, and then successively subjected to suction filtration, washing and vacuum drying to obtain pretreated pollen; 20 parts by weight of pretreated pollen are dispersed in 200 parts by weight of N,N-dimethylformamide, 13 parts by weight of hexamethylene diisocyanate and 0.45 parts by weight of dibutyltin dilaurate are added in a nitrogen protection environment, and the mixture is stirred and reacted at 60 °C for 18 h. After the reaction is completed, the product is successively subjected to centrifugal washing and vacuum drying to obtain a modified filler.

[0077] Preparation Example 12:

[0078] The preparation method of the modified filler comprises the following steps:

[0079] 50 parts by weight of sunflower pollen is dispersed in 100 parts by weight of deionized water, stirred at a speed of 1100 r / min at 60 °C for 3 h, then filtered to remove impurities, and then the water is removed by suction filtration to obtain pollen grains. The obtained pollen grains are dispersed in 100 parts by weight of acetone, stirred at a speed of 1100 r / min at 26 °C for 4 h, and then successively subjected to suction filtration and washing to obtain a solid powder. The obtained solid powder is dispersed in 100 parts by weight of ether, stirred at a speed of 1100 r / min at 26 °C for 12 h, and then successively subjected to suction filtration, washing and vacuum drying to obtain a modified filler.

[0080] Example 1:

[0081] A preparation method of an anti-fouling and self-cleaning powder coating includes the following steps:

[0082] 50 parts by weight of the modified resin prepared in Preparation Example 1, 15 parts by weight of the modified filler prepared in Preparation Example 7, 5 parts by weight of isophorone diisocyanate, 2 parts by weight of 2,6-di-tert-butyl-p-cresol, 1.5 parts by weight of carboxymethyl cellulose and 1.5 parts by weight of BYK-110 are mixed at 90 °C for 10 min, and then melt-extruded through a twin-screw extruder at temperatures of 80 °C in zone 1, 120 °C in zone 2, 140 °C in zone 3 and 160 °C in zone 4. After the extruded material is successively subjected to tabletting and crushing, sieved to obtain a powder with a particle size of 300 mesh to prepare an anti-fouling and self-cleaning powder coating.

[0083] Example 2:

[0084] A preparation method of an anti-fouling and self-cleaning powder coating includes the following steps:

[0085] 60 parts by weight of the modified resin prepared in Preparation Example 2, 18 parts by weight of the modified filler prepared in Preparation Example 8, 7 parts by weight of diphenylmethane diisocyanate, 2.5 parts by weight of antioxidant 3010, 1.8 parts by weight of hydroxyethyl cellulose and 1.7 parts by weight of BYK-P105 are mixed at 95 °C for 13 min, and then melt-extruded through a twin-screw extruder at temperatures of 85 °C in zone 1, 125 °C in zone 2, 145 °C in zone 3 and 165 °C in zone 4. After the extruded material is successively subjected to tabletting and crushing, sieved to obtain a powder with a particle size of 400 mesh to prepare an anti-fouling and self-cleaning powder coating.

[0086] Example 3:

[0087] A preparation method of an anti-fouling and self-cleaning powder coating includes the following steps:

[0088] 70 parts by weight of the modified resin prepared in Preparation Example 3, 22 parts by weight of the modified filler prepared in Preparation Example 9, 9 parts by weight of isophorone diisocyanate, 3 parts by weight of 2,6 - di - tert - butyl - p - cresol, 2.3 parts by weight of carboxymethyl cellulose, and 2.1 parts by weight of BYK - 110 were mixed at 105 °C for 18 min, and then melt - extruded through a twin - screw extruder at temperatures of 90 °C in zone 1, 130 °C in zone 2, 150 °C in zone 3, and 170 °C in zone 4. After the extruded material was successively tableted and crushed, it was sieved to obtain a powder with a particle size of 400 mesh to prepare an anti - fouling and self - cleaning powder coating.

[0089] Example 4:

[0090] A method for preparing an anti - fouling and self - cleaning powder coating, comprising the following steps:

[0091] 80 parts by weight of the modified resin prepared in Preparation Example 4, 25 parts by weight of the modified filler prepared in Preparation Example 10, 10 parts by weight of diphenylmethane diisocyanate, 4 parts by weight of antioxidant 3010, 2.5 parts by weight of hydroxyethyl cellulose, and 2.5 parts by weight of BYK - P105 were mixed at 110 °C for 20 min, and then melt - extruded through a twin - screw extruder at temperatures of 100 °C in zone 1, 140 °C in zone 2, and 160 °C in zone 3. After the extruded material was successively tableted and crushed, it was sieved to obtain a powder with a particle size of 500 mesh to prepare an anti - fouling and self - cleaning powder coating.

[0092] Comparative Example 1:

[0093] A method for preparing an anti - fouling and self - cleaning powder coating, comprising the following steps:

[0094] 80 parts by weight of the modified resin prepared in Preparation Example 5, 25 parts by weight of the modified filler prepared in Preparation Example 10, 10 parts by weight of diphenylmethane diisocyanate, 4 parts by weight of antioxidant 3010, 2.5 parts by weight of hydroxyethyl cellulose, and 2.5 parts by weight of BYK - P105 were mixed at 110 °C for 20 min, and then melt - extruded through a twin - screw extruder at temperatures of 100 °C in zone 1, 140 °C in zone 2, and 160 °C in zone 3. After the extruded material was successively tableted and crushed, it was sieved to obtain a powder with a particle size of 500 mesh to prepare an anti - fouling and self - cleaning powder coating.

[0095] Comparative Example 2:

[0096] A method for preparing an anti - fouling and self - cleaning powder coating, comprising the following steps:

[0097] 80 parts by weight of the modified resin prepared in Preparation Example 6, 25 parts by weight of the modified filler prepared in Preparation Example 10, 10 parts by weight of diphenylmethane diisocyanate, 4 parts by weight of antioxidant 3010, 2.5 parts by weight of hydroxyethyl cellulose, and 2.5 parts by weight of BYK-P105 were mixed at 110°C for 20 min, and then melt-extruded through a twin-screw extruder at a temperature of 100°C in zone 1, 140°C in zone 2, and 160°C in zone 3. The extruded material was successively tableted and crushed, and then sieved to obtain a powder with a particle size of 500 mesh to prepare an anti-fouling and self-cleaning powder coating.

[0098] Comparative Example 3:

[0099] A method for preparing an anti-fouling and self-cleaning powder coating, comprising the following steps:

[0100] 80 parts by weight of the modified resin prepared in Preparation Example 4, 25 parts by weight of the modified filler prepared in Preparation Example 11, 10 parts by weight of diphenylmethane diisocyanate, 4 parts by weight of antioxidant 3010, 2.5 parts by weight of hydroxyethyl cellulose, and 2.5 parts by weight of BYK-P105 were mixed at 110°C for 20 min, and then melt-extruded through a twin-screw extruder at a temperature of 100°C in zone 1, 140°C in zone 2, and 160°C in zone 3. The extruded material was successively tableted and crushed, and then sieved to obtain a powder with a particle size of 500 mesh to prepare an anti-fouling and self-cleaning powder coating.

[0101] Comparative Example 4:

[0102] A method for preparing an anti-fouling and self-cleaning powder coating, comprising the following steps:

[0103] 80 parts by weight of the modified resin prepared in Preparation Example 4, 25 parts by weight of the modified filler prepared in Preparation Example 12, 10 parts by weight of diphenylmethane diisocyanate, 4 parts by weight of antioxidant 3010, 2.5 parts by weight of hydroxyethyl cellulose, and 2.5 parts by weight of BYK-P105 were mixed at 110°C for 20 min, and then melt-extruded through a twin-screw extruder at a temperature of 100°C in zone 1, 140°C in zone 2, and 160°C in zone 3. The extruded material was successively tableted and crushed, and then sieved to obtain a powder with a particle size of 500 mesh to prepare an anti-fouling and self-cleaning powder coating.

[0104] Comparative Example 5:

[0105] A method for preparing an anti-fouling and self-cleaning powder coating, comprising the following steps:

[0106] 80 parts by weight of the modified resin prepared in Preparation Example 4, 15 parts by weight of sunflower pollen, 10 parts by weight of 1-adamantanol, 10 parts by weight of diphenylmethane diisocyanate, 4 parts by weight of antioxidant 3010, 2.5 parts by weight of hydroxyethyl cellulose and 2.5 parts by weight of BYK-P105 were mixed at 110 °C for 20 min, and then melt-extruded through a twin-screw extruder at a temperature of 100 °C in zone 1, 140 °C in zone 2 and 160 °C in zone 3. The extruded material was successively subjected to tablet pressing and crushing, and then sieved to obtain a powder with a particle size of 500 mesh to prepare an anti-fouling and self-cleaning powder coating.

[0107] Performance test:

[0108] The anti-fouling and self-cleaning powder coatings prepared in Examples 1 to 4 and Comparative Examples 1 to 5 were sprayed on aluminum sheets of 50 mm × 100 mm with a spray gun, cured at 220 °C for 90 min, and the thickness of the cured coating was about 90 μm, and then performance tests were carried out respectively.

[0109] (1) Self-cleaning performance test

[0110] The self-cleaning performance was tested by the erasing effect of lipstick marks, the erasing effect of marker pen marks and the water contact angle. The test results are shown in Table 1.

[0111] Water contact angle test method: The test was carried out according to the method in GB / T 30693-2014;

[0112] The wiping method of lipstick and marker pen marks: Lipstick and marker pen marks were smeared on the above-mentioned coatings with the same force, and after standing for one week, the lipstick and marker pen marks were wiped off with a dry paper towel and observed to evaluate the wiping and decontamination grade. Among them, the wiping grade of 1 indicates being wiped off, 2 indicates easy to wipe off; 3 indicates difficult to wipe off, 4 indicates unable to wipe off; being wiped off means that more than 90% of the marks are wiped off; easy to wipe off means that 50-90% of the marks are wiped off; difficult to wipe off means that 20-50% of the marks are wiped off; unable to wipe off means that 0-20% of the marks are wiped off.

[0113] Table 1. Self-cleaning performance

[0114] Water contact angle / ° Lipstick wiping grade Marker pen wiping grade Example 1 153.7 1 1 Example 2 155.1 1 1 Example 3 156.3 1 1 Example 4 157.4 1 1 Comparative example 1 137.6 2 3 Comparative example 2 141.5 2 2 Comparative example 3 135.3 2 3 Comparative example 4 132.7 3 3 Comparative example 5 128.6 4 4

[0115] From the test results in Table 1, it can be seen that the powder coatings prepared in Examples 1 to 4 of the present invention have excellent self-cleaning effects, the water contact angle can reach 157.4°, the lipstick wiping grade is 1, and the marker pen wiping grade is 1.

[0116] The self-cleaning effects of Comparative Examples 1-3 were inferior to those of Examples 1-4. This might be because the silane groups in diethoxymethyl[(3-epoxyethanylmethoxy)propyl]silane, the tert-butylphenyl groups in linalool oxide, and the adamantane in 1-adamantanol in the present invention cooperated with each other to jointly reduce the surface energy of the powder coating and enhance the superhydrophobic performance of the powder coating, thus affecting its self-cleaning effect. The self-cleaning effects of Comparative Examples 4-5 were relatively poor. This might be because the surface of pure sunflower pollen contains abundant hydroxyl groups. If it is directly applied to the powder coating without surface modification, it will greatly increase the hydrophilicity of the powder coating and affect its self-cleaning effect.

[0117] (2) Mechanical property testing

[0118] Refer to the method in GB / T 1732-1993 to test the impact resistance of the above-prepared coatings. The test results are shown in Table 2.

[0119] Table 2. Impact resistance test

[0120] Impact resistance / (kg·cm) Example 1 57.31 Example 2 59.86 Example 3 61.48 Example 4 63.56 Comparative example 1 54.17 Comparative example 2 51.63 Comparative example 3 45.29 Comparative example 4 49.62 Comparative example 5 47.37

[0121] From the test results in Table 2, it can be known that the powder coatings prepared in Examples 1-4 of the present invention have excellent impact resistance. The poor impact resistance of Comparative Example 1, Comparative Example 3, and Comparative Example 4 might be due to the lack of the rigid structure of the aromatic ring or the cage structure of adamantane. The poor impact resistance of Comparative Example 2 might be due to the lack of the silane structure, which affected the interaction between the modified filler and the modified resin. The poor impact resistance of Comparative Example 5 might be due to the lack of modification of sunflower pollen and 1-adamantanol, making it impossible to fully interact with the modified resin.

[0122] In summary, by regulating the ratio of each component raw material and utilizing the synergistic effect between the component raw materials, the present invention provides an anti-fouling self-cleaning powder coating with good self-cleaning performance and impact resistance.

[0123] The above embodiments have described in detail the technical solutions and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A method for preparing an anti-fouling self-cleaning powder coating, characterized in that: The preparation method comprises the following steps: The modified resin, modified filler, curing agent, antioxidant, leveling agent and dispersant are mixed, and then melt-extruded, tableted, crushed and sieved in sequence to obtain the anti-fouling self-cleaning powder coating.

2. The method for preparing an anti-fouling self-cleaning powder coating according to claim 1, characterized in that: The preparation method of the modified resin comprises the following steps: Lilial and ethylenediamine react to obtain an intermediate product A, and the intermediate product A reacts with epichlorohydrin to obtain an intermediate product B; phthalic anhydride, ethylene glycol and p-toluenesulfonic acid react to obtain a mixture, and the mixture, the intermediate product B, epoxysilane and triphenylphosphine react to obtain the modified resin.

3. The method for preparing an anti-fouling self-cleaning powder coating according to claim 1, characterized in that: The preparation method of the modified filler comprises the following steps: Sunflower pollen is treated with deionized water, acetone and ether in sequence to obtain pretreated pollen, and the pretreated pollen, 1-adamantanol, hexamethylene diisocyanate and dibutyltin dilaurate are reacted to obtain the modified filler.

4. The method for preparing an anti-fouling self-cleaning powder coating according to claim 2, characterized in that: The epoxysilane is diethoxymethyl[(3-oxiranylmethoxy)propyl]silane.

5. The method for preparing an anti-fouling self-cleaning powder coating according to claim 1, characterized in that: The curing agent includes isophorone diisocyanate or diphenylmethane diisocyanate.

6. The method for preparing an anti-fouling self-cleaning powder coating according to claim 1, characterized in that: The antioxidant includes 2,6-di-tert-butyl-p-cresol or antioxidant 3010.

7. The method for preparing an anti-fouling self-cleaning powder coating according to claim 1, characterized in that ,, the leveling agent includes carboxymethyl cellulose or hydroxyethyl cellulose.

8. The method for preparing an anti-fouling self-cleaning powder coating according to claim 1, characterized in that: The dispersant includes BYK-110 or BYK-P105.

9. The method for preparing an anti-fouling self-cleaning powder coating according to claim 1, characterized in that: The weight ratio of the modified resin, the modified filler, the curing agent, the antioxidant, the leveling agent and the dispersant is 50-80:15-25:5-10:2-4:1.5-2.5:1.5-2.

5. 10.An anti-fouling self-cleaning powder coating, characterized in that: The anti-fouling self-cleaning powder coating is prepared by the preparation method of any one of claims 1 to 9.