An anti-fouling self-cleaning powder coating and a method for preparing the same

Abstract

The application 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 a modified resin, a modified filler, a curing agent, an antioxidant, a leveling agent and a dispersing agent, and then sequentially performing melt extrusion, tabletting, crushing and sieving to obtain the anti-fouling self-cleaning powder coating. In the application, the silane group, the tert-butyl phenyl group and the adamantane structure provide a low surface energy to form a hydrophobic substrate, the multi-level micro-nano rough structure of the pretreated pollen itself provides a morphology basis for a super-hydrophobic surface, the hydrophobic group of 1-adamantanol and hexamethylene diisocyanate is grafted to enhance the hydrophobicity of the pretreated pollen, the materials are synergized to build a micro-nano binary structure similar to a lotus leaf, a super-hydrophobic surface is formed to reduce the adhesion of pollutants, and thus the anti-fouling self-cleaning effect is realized.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of powder coating, in particular to an anti-fouling self-cleaning powder coating and a preparation method thereof. BACKGROUND

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

[0003] With the increasing seriousness of air pollution and dust pollution, the surface coating in contact with air is suffering more and more serious erosion. The surface of such coating can only 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, the multiple cleaning process will affect the surface performance of the coating, for example, multiple cleaning will reduce the flatness, brightness, adhesion and other effects of the coating. Some super-hydrophobic coatings rely on fluorine-containing compounds to reduce surface energy, but fluorine may cause long-term pollution to the environment, and may release volatile toxic gases during high-temperature curing. In addition, when preparing self-cleaning powder coating, adding inorganic particles and other ingredients can increase the self-cleaning performance of the powder coating, but the inorganic filler has poor compatibility with the resin matrix, and it is 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, which uses polytetrafluoroethylene resin as a low-surface-energy substance and adds modified nano-silicon dioxide to 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. The fabric surface treated by the two-component super-hydrophobic coating has super-hydrophobic properties, meeting the demand of materials for hydrophobicity and self-cleaning. However, a large amount of inorganic hydrophobic filler is added during the preparation process, which may affect the impact resistance of the coating.

[0005] Therefore, it is an important problem to be solved in the field to provide an anti-fouling self-cleaning powder coating without fluorine and with good self-cleaning effect and impact resistance. SUMMARY

[0006] To solve the problems in the prior art, the present application provides an anti-fouling self-cleaning powder coating and a preparation method thereof. Specifically, the technical scheme of the present application includes the following contents:

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

[0008] The modified resin, the modified filler, the curing agent, the antioxidant, the leveling agent and the dispersant are mixed, and then the anti-fouling self-cleaning powder coating is prepared by melt extrusion, tabletting, crushing and sieving in sequence.

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

[0010] Lilial and ethylenediamine react to obtain an intermediate product A, and the intermediate product A and epichlorohydrin react 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, an 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 treated with deionized water, acetone and diethyl ether in sequence 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 and 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 3-5h.

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

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

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

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

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

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

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

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

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

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

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

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

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

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

[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 dispersing agent includes BYK-110 or BYK-P105.

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

[0034] Further, the conditions for the melt extrusion include a melt extrusion temperature of 80-100°C for a first zone, 120-140°C for a second zone, 140-160°C for a third zone and 160-180°C for a fourth zone, respectively.

[0035] Further, the screen mesh for the sieving is 300-500 mesh.

[0036] Further, 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.

[0037] Compared with the prior art, the application has the following advantages:

[0038] (1) In the application, the intermediate product A is obtained by Schiff base reaction of the lilial and the ethylenediamine, the intermediate product B is obtained by substitution reaction of the intermediate product A and the epichlorohydrin, the mixture is obtained by esterification reaction of the phthalic anhydride and the ethylene glycol, and the modified resin is prepared by epoxy ring opening reaction of the mixture, the intermediate product B and the diethoxymethyl [(3-oxiranylmethoxy) propyl] silane; the pretreated pollen is obtained by sequentially treating the sunflower pollen with deionized water, acetone and diethyl ether, and the modified filler is prepared by nucleophilic addition reaction of the pretreated pollen, the 1-adamantanol and the hexamethylene diisocyanate

[0039] (2) In the application, the silane group, the tertiary butyl phenyl and the adamantane structure provide a low surface energy to form a hydrophobic substrate, the pretreated pollen itself provides a multi-level micro-nano rough structure for the super-hydrophobic surface, and the hydrophobic group of the 1-adamantanol and the hexamethylene diisocyanate is grafted to enhance the hydrophobicity of the pretreated pollen, so that the materials are synergistically combined to form a micro-nano dual structure similar to a lotus leaf, the super-hydrophobic surface is formed to reduce the adhesion of pollutants, and the efficient anti-fouling and self-cleaning effect is realized.

[0040] (3) In the application, the flexible chain segment in the modified resin provides flexibility, and the rigidity of the aromatic ring hinders crack propagation; the polyurethane formed by the pretreated pollen, the 1-adamantanol and the hexamethylene diisocyanate in the modified filler can interact with the modified resin, the cage structure of the adamantane can not only provide rigid support but also inhibit the agglomeration of the filler to ensure uniform dispersion and avoid local stress concentration, and the various effects are synergistically combined to make the powder coating have good impact resistance.

[0041] (4) The anti-fouling and self-cleaning powder coating provided by the application does not contain fluorides, and the biological accumulation and health risks caused by traditional fluorine-containing coatings are avoided. DETAILED DESCRIPTION

[0042] The technical solutions of the application will be clearly and completely described below through the embodiments of the application. Obviously, the described embodiments are only part of the embodiments of the application, rather than all the embodiments. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor belong to the protection scope of the application.

[0043] The raw materials and reagents used in the present application below are commercially available or can be prepared by known methods unless otherwise specified.

[0044] Preparation Example 1:

[0045] The method for preparing the modified resin comprises the following steps:

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

[0047] Preparation Example 2:

[0048] The method for preparing the modified resin comprises the following steps:

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

[0050] Preparation Example 3:

[0051] A method for preparing a modified resin, comprising the steps of:

[0052] 22 parts by weight of lilial and 9 parts by weight of ethylenediamine are dispersed in 500 parts by weight of methanol, the pH is adjusted to 7.5, and then the mixture is stirred and reacted at 100°C for 4 hours under a nitrogen atmosphere. After the reaction is completed, the intermediate product A is obtained by sequentially performing suction filtration, washing, and recrystallization. 12 parts by weight of the intermediate product A and 4 parts by weight of epichlorohydrin are dispersed in 200 parts by weight of N,N-dimethylformamide, the pH is adjusted to 9, and then the mixture is stirred and reacted at 82°C for 5.7 hours under a nitrogen atmosphere. After the reaction is completed, the intermediate product B is obtained by sequentially performing 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, and the mixture is stirred and reacted at 125°C for 5 hours under a nitrogen atmosphere. Then, 15 parts by weight of the intermediate product B, 12 parts by weight of diethoxymethyl [(3-oxiranylmethoxy)propyl]silane, and 0.28 parts by weight of triphenylphosphine are added, and the mixture is stirred and reacted at 113°C for 4 hours under a nitrogen atmosphere. After the reaction is completed, the modified resin is obtained by sequentially performing vacuum distillation, drying, and pulverization.

[0053] Preparation Example 4:

[0054] A method for preparing a modified resin, comprising the steps of:

[0055] 25 parts by weight of lilial and 10 parts by weight of ethylenediamine are dispersed in 500 parts by weight of methanol, the pH is adjusted to 8, and then the mixture is stirred and reacted at 110°C for 5 hours under a nitrogen atmosphere. After the reaction is completed, the intermediate product A is obtained by sequentially performing suction filtration, washing, and recrystallization. 15 parts by weight of the intermediate product A and 5 parts by weight of epichlorohydrin are dispersed in 200 parts by weight of N,N-dimethylformamide, the pH is adjusted to 10, and then the mixture is stirred and reacted at 85°C for 6 hours under a nitrogen atmosphere. After the reaction is completed, the intermediate product B is obtained by sequentially performing 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, and the mixture is stirred and reacted at 130°C for 6 hours under a nitrogen atmosphere. Then, 16 parts by weight of the intermediate product B, 13 parts by weight of diethoxymethyl [(3-oxiranylmethoxy)propyl]silane, and 0.30 parts by weight of triphenylphosphine are added, and the mixture is stirred and reacted at 115°C for 5 hours under a nitrogen atmosphere. After the reaction is completed, the modified resin is obtained by sequentially performing vacuum distillation, drying, and pulverization.

[0056] Preparation Example 5:

[0057] A method for preparing a modified resin, comprising the steps of:

[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 the mixture is stirred at 130°C for 6 hours under nitrogen atmosphere to obtain a reaction product. Then, 13 parts by weight of diethoxymethyl [(3-oxiranylmethoxy)propyl] silane and 0.15 parts by weight of triphenylphosphine are added, and the mixture is stirred at 115°C for 5 hours under nitrogen atmosphere. After the reaction is completed, the reaction product is subjected to vacuum distillation, drying and pulverization in this order to obtain the modified resin.

[0059] Preparation Example 6:

[0060] A method for preparing the modified resin comprises the following steps:

[0061] 25 parts by weight of lilial and 10 parts by weight of ethylenediamine are dispersed in 500 parts by weight of methanol, and the pH is adjusted to 8. Then, the mixture is stirred at 110°C for 5 hours under nitrogen atmosphere to obtain an intermediate product A. 15 parts by weight of the intermediate product A and 5 parts by weight of epichlorohydrin are dispersed in 200 parts by weight of N,N-dimethylformamide, and the pH is adjusted to 10. Then, the mixture is stirred at 85°C for 6 hours under nitrogen atmosphere to obtain an intermediate product B. 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 the mixture is stirred at 130°C for 6 hours under nitrogen atmosphere to obtain a reaction product. Then, 16 parts by weight of the intermediate product B and 0.17 parts by weight of triphenylphosphine are added, and the mixture is stirred at 115°C for 5 hours under nitrogen atmosphere. After the reaction is completed, the reaction product is subjected to vacuum distillation, drying and pulverization in this order to obtain the modified resin.

[0062] Preparation Example 7:

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

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

[0065] Preparation Example 8:

[0066] The method for preparing the modified filler comprises the following steps:

[0067] 50 parts by weight of sunflower pollen was dispersed in 100 parts by weight of deionized water, and after stirring at 950 r / min for 2.2 h at 52°C, impurities were removed by filtration, and then the water was removed by suction filtration to obtain pollen particles. The obtained pollen particles were dispersed in 100 parts by weight of acetone, and after stirring at 950 r / min for 3.2 h at 25°C, solid powder was obtained by suction filtration and washing in sequence. The obtained solid powder was dispersed in 100 parts by weight of diethyl ether, and after stirring at 950 r / min for 9 h at 25°C, the pretreated pollen was obtained by suction filtration, washing and vacuum drying in sequence. 13 parts by weight of the pretreated pollen and 9 parts by weight of 1-adamantanol were dispersed in 200 parts by weight of N,N-dimethylformamide, and 10 parts by weight of hexamethylene diisocyanate and 0.3 parts by weight of dibutyltin dilaurate were added in a nitrogen protection environment. After stirring at 52°C for 14 h, the reaction was completed, and the modified filler was obtained by centrifugal washing and vacuum drying in sequence.

[0068] Preparation Example 9:

[0069] The method for preparing the modified filler comprises the following steps:

[0070] 50 parts by weight of sunflower pollen was dispersed in 100 parts by weight of deionized water, and after stirring at 950 r / min for 2.2 h at 52°C, impurities were removed by filtration, and then the water was removed by suction filtration to obtain pollen particles. The obtained pollen particles were dispersed in 100 parts by weight of acetone, and after stirring at 950 r / min for 3.2 h at 25°C, solid powder was obtained by suction filtration and washing in sequence. The obtained solid powder was dispersed in 100 parts by weight of diethyl ether, and after stirring at 950 r / min for 9 h at 25°C, the pretreated pollen was obtained by suction filtration, washing and vacuum drying in sequence. 13 parts by weight of the pretreated pollen and 9 parts by weight of 1-adamantanol were dispersed in 200 parts by weight of N,N-dimethylformamide, and 10 parts by weight of hexamethylene diisocyanate and 0.3 parts by weight of dibutyltin dilaurate were added in a nitrogen protection environment. After stirring at 52°C for 14 h, the reaction was completed, and the modified filler was obtained by centrifugal washing and vacuum drying in sequence.

[0071] Preparation Example 10:

[0072] The method for preparing the modified filler comprises the following steps:

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

[0074] Preparation Example 11:

[0075] The method for preparing the modified filler includes the following steps:

[0076] 50 parts by weight of sunflower pollen was dispersed in 100 parts by weight of deionized water, stirred at 1100 r / min for 3 h at 60°C, and then filtered to remove impurities. The pollen particles were obtained by vacuum filtration to remove water. The obtained pollen particles were dispersed in 100 parts by weight of acetone, stirred at 1100 r / min for 4 h at 26°C, and then sequentially subjected to vacuum filtration and washing to obtain a solid powder. The obtained solid powder was dispersed in 100 parts by weight of diethyl ether, stirred at 1100 r / min for 12 h at 26°C, and then sequentially subjected to vacuum filtration, washing, and vacuum drying to obtain pretreated pollen. 20 parts by weight of the pretreated pollen and 12 parts by weight of 1-adamantanol were dispersed in 200 parts by weight of N,N-dimethylformamide. Under a nitrogen atmosphere, 13 parts by weight of hexamethylene diisocyanate and 0.45 parts by weight of dibutyltin dilaurate were added, and the mixture was stirred and reacted at 60°C for 18 h. After the reaction, the mixture was sequentially subjected to centrifugal washing and vacuum drying to obtain a modified filler.

[0077] Preparation Example 12:

[0078] The method for preparing the modified filler includes the following steps:

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

[0080] Example 1:

[0081] A method for preparing an anti-fouling self-cleaning powder coating, comprising 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 were mixed at 90°C for 10 min, and then melt-extruded through a twin-screw extruder at a temperature of 80°C in the first zone, 120°C in the second zone, 140°C in the third zone, and 160°C in the fourth zone. The extruded material was sequentially subjected to tabletting and crushing, and then sieved to obtain a powder with a particle size of 300 mesh to prepare an anti-fouling self-cleaning powder coating.

[0083] Example 2:

[0084] A method for preparing an anti-fouling self-cleaning powder coating, comprising 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 were mixed at 95°C for 13 min, and then melt-extruded through a twin-screw extruder at a temperature of 85°C in the first zone, 125°C in the second zone, 145°C in the third zone, and 165°C in the fourth zone. The extruded material was sequentially subjected to tabletting and crushing, and then sieved to obtain a powder with a particle size of 400 mesh to prepare an anti-fouling self-cleaning powder coating.

[0086] Example 3:

[0087] A method for preparing an anti-fouling self-cleaning powder coating, comprising 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 are mixed at 105°C for 18 minutes, and then melt-extruded through a twin-screw extruder at a temperature of 90°C in the first zone, 130°C in the second zone, 150°C in the third zone, and 170°C in the fourth zone. The extruded material is sequentially subjected to tableting and crushing, and then sieved to obtain a powder having a particle size of 400 mesh to prepare a stain-resistant self-cleaning powder coating.

[0089] Example 4:

[0090] A method for preparing a stain-resistant self-cleaning powder coating, comprising the steps of:

[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 are mixed at 110°C for 20 minutes, and then melt-extruded through a twin-screw extruder at a temperature of 100°C in the first zone, 140°C in the second zone, and 160°C in the third zone. The extruded material is sequentially subjected to tableting and crushing, and then sieved to obtain a powder having a particle size of 500 mesh to prepare a stain-resistant self-cleaning powder coating.

[0092] Comparative Example 1:

[0093] A method for preparing a stain-resistant self-cleaning powder coating, comprising the steps of:

[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 are mixed at 110°C for 20 minutes, and then melt-extruded through a twin-screw extruder at a temperature of 100°C in the first zone, 140°C in the second zone, and 160°C in the third zone. The extruded material is sequentially subjected to tableting and crushing, and then sieved to obtain a powder having a particle size of 500 mesh to prepare a stain-resistant self-cleaning powder coating.

[0095] Comparative Example 2:

[0096] A method for preparing a stain-resistant self-cleaning powder coating, comprising the steps of:

[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 diphenyl methane 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 are mixed at 110°C for 20 minutes, and then melt-extruded through a twin-screw extruder at a temperature of 100°C in the first zone, 140°C in the second zone, and 160°C in the third zone. The extruded material is sequentially subjected to tabletting and crushing, and then sieved to obtain a powder having a particle size of 500 mesh to prepare a stain-resistant self-cleaning powder coating.

[0098] Comparative Example 3:

[0099] A method for preparing a stain-resistant self-cleaning powder coating, comprising the steps of:

[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 diphenyl methane 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 are mixed at 110°C for 20 minutes, and then melt-extruded through a twin-screw extruder at a temperature of 100°C in the first zone, 140°C in the second zone, and 160°C in the third zone. The extruded material is sequentially subjected to tabletting and crushing, and then sieved to obtain a powder having a particle size of 500 mesh to prepare a stain-resistant self-cleaning powder coating.

[0101] Comparative Example 4:

[0102] A method for preparing a stain-resistant self-cleaning powder coating, comprising the steps of:

[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 diphenyl methane 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 are mixed at 110°C for 20 minutes, and then melt-extruded through a twin-screw extruder at a temperature of 100°C in the first zone, 140°C in the second zone, and 160°C in the third zone. The extruded material is sequentially subjected to tabletting and crushing, and then sieved to obtain a powder having a particle size of 500 mesh to prepare a stain-resistant self-cleaning powder coating.

[0104] Comparative Example 5:

[0105] A method for preparing a stain-resistant self-cleaning powder coating, comprising the steps of:

[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 minutes, and then melt-extruded through a twin-screw extruder at a temperature of 100°C in a first zone, 140°C in a second zone, and 160°C in a third zone. The extruded material was sequentially subjected to tabletting and crushing, and then sieved to obtain a powder having a particle size of 500 mesh to prepare a stain-resistant self-cleaning powder coating.

[0107] Performance test:

[0108] The stain-resistant self-cleaning powder coatings prepared in Examples 1 to 4 and Comparative Examples 1 to 5 were sprayed on aluminum sheets having a size of 50 mm x 100 mm using a spray gun, and cured at 220°C for 90 minutes. The thickness of the cured coating layer was about 90 μm, and then the performance test was performed.

[0109] (1) Self-cleaning performance test

[0110] The self-cleaning performance test was performed using a lipstick mark erasing effect, a marker pen mark erasing effect, and a water contact angle. The test results are shown in Table 1.

[0111] Water contact angle test method: The test was performed according to the method described in GB / T 30693-2014.

[0112] Lipstick and marker pen mark wiping method: The marks of lipstick and marker pen were applied on the coating layer prepared above using the same force, and then the marks of lipstick and marker pen were wiped off using a dry paper towel after standing for one week. The wiping and stain removal levels were evaluated by observation. In the evaluation, grade 1 indicates that the marks were wiped off, grade 2 indicates that the marks were easily wiped off, grade 3 indicates that the marks were difficult to wipe off, and grade 4 indicates that the marks could not be wiped off. Wiped off means that more than 90% of the marks were wiped off, easily wiped off means that 50-90% of the marks were wiped off, difficult to wipe off means that 20-50% of the marks were wiped off, and could not be wiped off means that 0-20% of the marks were wiped off.

[0113] Table 1. Self-cleaning performance

[0114] Water contact angle / ° Lipstick rub rating Marker rub rating 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] As can be seen from the test results in Table 1, the powder coatings prepared in Examples 1 to 4 have excellent self-cleaning effects, and the water contact angle can reach 157.4°, the lipstick wiping level is grade 1, and the marker pen wiping level is grade 1.

[0116] The self-cleaning effect of Comparative Examples 1-3 is not as good as that of Examples 1-4, which may be due to the mutual cooperation between the silane group in diethoxymethyl [(3-oxiranylmethoxy)propyl] silane, the tert-butyl phenyl in lily aldehyde and the adamantane in 1-adamantanol, which together reduce the surface energy of the powder coating and enhance the super-hydrophobic property of the powder coating, thereby affecting the self-cleaning effect thereof; the self-cleaning effect of Comparative Examples 4-5 is poor, which may be due to the fact that the pure sunflower pollen surface contains a large amount of hydroxyl groups, and the surface is not modified but directly applied to the powder coating, which greatly increases the hydrophilicity of the powder coating and affects the self-cleaning effect thereof.

[0117] (2) Mechanical property test

[0118] The impact resistance of the coating prepared above was tested according to the method in GB / T 1732-1993, and 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] It can be seen from the test results in Table 2 that the powder coating prepared in Examples 1-4 of the present application has excellent impact resistance, and the impact resistance of Comparative Examples 1, 3 and 4 is poor, which may be due to the lack of rigid structure of aromatic ring or the cage structure of adamantane, the impact resistance of Comparative Example 2 is poor, which may be due to the lack of silane structure, which affects the interaction between the modified filler and the modified resin, and the impact resistance of Comparative Example 5 is poor, which may be due to the fact that the sunflower pollen and 1-adamantanol are not modified, and cannot fully interact with the modified resin.

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

[0123] The above examples have described the technical solutions and beneficial effects of the present application in detail, and it should be understood that the above description is only a specific embodiment of the present application and is not intended to limit the present application. Without departing from the spirit and scope of the present application, various changes and improvements can be made to the present application, and these changes and improvements all fall within the scope of the present application.

Claims

1. A method for preparing a stain resistant self-cleaning powder coating, characterized in that, The preparation method comprises the following steps: The modified resin, the modified filler, the curing agent, the antioxidant, the leveling agent and the dispersant are mixed, and then the anti-fouling self-cleaning powder coating is prepared through melt extrusion, tabletting, crushing and sieving in sequence. The preparation method of the modified resin comprises the following steps: The intermediate product A is obtained by reacting lilial and ethylenediamine, and the intermediate product B is obtained by reacting the intermediate product A and epichlorohydrin; the mixture is obtained by reacting phthalic anhydride, ethylene glycol and p-toluenesulfonic acid, and the modified resin is prepared by reacting the mixture, the intermediate product B, epoxysilane and triphenylphosphine; The preparation method of the modified filler comprises the following steps: The pretreated pollen is obtained by sequentially treating sunflower pollen with deionized water, acetone and diethyl ether, and the modified filler is prepared by reacting the pretreated pollen, 1-adamantanol, hexamethylene diisocyanate and dibutyltin dilaurate; The epoxysilane is diethoxymethyl [(3-oxiranylmethoxy) propyl] silane.

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

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

4. The method for preparing an anti-fouling self-cleaning powder coating according to claim 1, wherein: The leveling agent comprises carboxymethyl cellulose or hydroxyethyl cellulose.

5. The method for preparing an anti-fouling self-cleaning powder coating according to claim 1, wherein: The dispersant comprises BYK-110 or BYK-P105.

6. 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.

7. An anti-soiling, 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 1-6. The anti-fouling self-cleaning powder coating is prepared by the preparation method of any one of claims 1-6.