Environment-friendly fluoride-free super-hydrophobic coating material and preparation method thereof

Abstract

The invention discloses an environment-friendly fluoride-free super-hydrophobic coating material and a preparation method thereof, and belongs to the technical field of super-hydrophobic coating materials. The preparation method comprises the following steps: mixing hyperbranched polyurethane, ethyl acetate and propylene glycol methyl ether acetate for 10-20 minutes, adding polydimethylsiloxane and octadecyl isocyanate, mixing and reacting for 60-80 minutes, adding multi-stage microspheres, carrying out ultrasonic treatment for 15-30 minutes, adding an initiator, and carrying out ultrasonic treatment for 20-30 minutes, thereby obtaining the hyperbranched polyurethane adhesive. Adding Isopar G, isophorone diisocyanate, a silane coupling agent KH-560, dibutyltin dilaurate and triethylene diamine, and stirring and dispersing for 30 to 50 minutes, so as to obtain the environment-friendly fluorine-free super-hydrophobic coating material. The environment-friendly fluoride-free super-hydrophobic coating material prepared by the invention has good super-hydrophobicity, self-repairing function and wear resistance.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of super-hydrophobic coating materials, and particularly relates to an environmentally-friendly fluorine-free super-hydrophobic coating material and a preparation method thereof. BACKGROUND

[0002] In the field of material protection, super-hydrophobic coatings have become a key protection scheme in high-end fields such as aerospace, deep-sea equipment and energy facilities due to their unique self-cleaning, anti-icing, anti-corrosion and anti-rust core characteristics. Such coatings can achieve a super-hydrophobic state with a liquid contact angle of > 150° by constructing a special surface structure, which can effectively resist liquid erosion, reduce surface contamination and significantly prolong the service life of equipment. However, the current mainstream super-hydrophobic coating technology still faces three major industry bottlenecks that need to be broken through in practical applications, which seriously restricts its large-scale promotion.

[0003] Existing technologies generally rely on perfluorinated compounds (such as perfluorooctane sulfonate PFOS and perfluorooctanoic acid PFOA) to construct low-surface-energy surfaces. Such substances have strong bioaccumulation and environmental persistence, and can still be enriched through the food chain even at trace concentrations, posing a potential threat to ecosystems and human health, and have been listed in the control list of persistent organic pollutants by many countries. This development model of “function realization at the expense of the environment” is in sharp contradiction with the development concept of global green manufacturing. The core of super-hydrophobic performance relies on the synergistic effect of micro-nano rough structure and low-surface-energy substances, but mechanical wear can easily damage this delicate structure, leading to irreversible decay of hydrophobicity. Traditional self-healing coatings mostly use a single repair mechanism (such as hydrogen bond recombination and dynamic coordination bond reconstruction), which can only deal with molecular-level micro-damage and completely fails in the face of deep scratches or large-area wear, greatly shortening the actual service period of the coating. To improve wear resistance, existing solutions often introduce rigid reinforcing phases such as SiO2 and TiO2, but there is a serious interface compatibility problem between these inorganic microparticles and the organic polymer matrix, which can easily form stress concentration points under cyclic stress, leading to microsphere detachment or coating cracking.

[0004] CN 103409028A prepared a photocatalytic self-healing super-hydrophobic coating and a preparation method thereof. The coating prepared by using hydrophobically modified nanoparticles, photocatalytic nanoparticles and low-surface-energy substances containing active groups can realize self-repairing of the surface structure under UV irradiation after wear. However, due to the uncontrollability of UV irradiation crosslinking, self-repairing may be only one-time, and the durability of the super-hydrophobic coating is still difficult to solve.

[0005] Therefore, it is an important problem to be solved in the field to provide a fluorine-free super-hydrophobic coating material with good self-repairing performance. SUMMARY

[0006] To solve the problems in the prior art, the application provides an environment-friendly fluorine-free super-hydrophobic coating material and a preparation method thereof, and specifically, the technical scheme of the application comprises the following contents.

[0007] A preparation method of an environment-friendly fluorine-free super-hydrophobic coating material, comprising the following steps:

[0008] The hyperbranched polyurethane, ethyl acetate and propylene glycol methyl ether acetate are mixed for 10-20 min, then the polydimethylsiloxane and octadecyl isocyanate are added and mixed for 60-80 min, then the multi-stage microspheres are ultrasonically treated for 15-30 min, then the Isopar G, isophorone diisocyanate, silane coupling agent KH-560, dibutyl tin dilaurate and triethylenediamine are added and stirred and dispersed for 30-50 min to obtain the environment-friendly fluorine-free super-hydrophobic coating material.

[0009] Further, the preparation method of the hyperbranched polyurethane comprises the following steps:

[0010] 3,4-dihydroxybenzoic acid and allyl boronic pinacol ester are mixed to obtain a first intermediate;

[0011] The first intermediate, hydroxyethyl methacrylate, EDC and DMAP are mixed to obtain a second intermediate;

[0012] The second intermediate, beta-mercaptoethanol and 2,2-dimethoxy-phenyl acetophenone are mixed and treated by irradiation of a 395 nm LED light source to obtain a modified borate ester;

[0013] Trimethylolpropane, dimethylolpropionic acid and isophorone diisocyanate are mixed for 30-50 min, then dibutyl tin diacetate is added and mixed to obtain a first intermediate system;

[0014] The first intermediate system and the modified borate ester are mixed to obtain a second intermediate system;

[0015] The second intermediate system and the hydroxyl-terminated polydimethylsiloxane are mixed for 3-5 h, then triethylamine is added and mixed for 30-60 min, and then deionized water is added and mixed for 40-60 min to obtain the hyperbranched polyurethane.

[0016] Further, the weight ratio of the 3,4-dihydroxybenzoic acid and the allyl boronic pinacol ester is 4.1-4.5:5.7-6.1.

[0017] Further, the mixing reaction conditions of the 3,4-dihydroxybenzoic acid and the allyl boronic pinacol ester comprise a reaction temperature of 60-70 DEG C and a reaction time of 4-6 h.

[0018] Further, the weight ratio of the first intermediate, hydroxyethyl methacrylate, EDC and DMAP is 7-9:5-7:8-10:4-6.

[0019] Further, the reaction conditions of the mixture of the first intermediate, hydroxyethyl methacrylate, EDC and DMAP include a reaction temperature of 23-25°C and a reaction time of 24-48h.

[0020] Further, the weight ratio of the second intermediate, β-mercaptoethanol and 2,2-dimethoxy-phenyl phenylacetophenone is 5-7:2.5-3.5:0.05-0.1.

[0021] Further, the treatment conditions of the 395nm LED light source include a treatment power of 50-80mW / cm 2 and a treatment time of 30-50min.

[0022] Further, the weight ratio of the trimethylolpropane, dimethylolpropanoic acid, isophorone diisocyanate, dibutyl tin diacetate, modified borate ester, hydroxyl-terminated polydimethylsiloxane, triethylamine and deionized water is 5.5-7.5:3-5:20-25:0.015-0.03:6-8:6.5-8.5:2-4:140-160.

[0023] Further, the reaction conditions of the mixture of the trimethylolpropane, isophorone diisocyanate and dibutyl tin diacetate include a reaction temperature of 60-70°C and a reaction time of 3-5h.

[0024] Further, the reaction conditions of the mixture of the first intermediate and the modified borate ester include a reaction temperature of 50-60°C and a reaction time of 2-4h.

[0025] Further, the preparation method of the multi-stage microspheres includes the following steps:

[0026] After mixing and stirring the diatomite and 10wt% hydrochloric acid solution, the activated diatomite is obtained by high-temperature calcination;

[0027] The mixture solution is obtained by mixing zinc nitrate dihydrate and triethylamine;

[0028] The growth solution is obtained by mixing hexamethylenetetramine and zinc nitrate hexahydrate;

[0029] The diatomite intermediate is obtained by dispersing the activated diatomite in the mixture solution and soaking for 5-15min;

[0030] The zinc oxide diatomite composite is obtained by mixing and reacting the diatomite intermediate and the growth solution;

[0031] The zinc sulfide diatomite composite is obtained by mixing and reacting the zinc oxide diatomite composite and sodium sulfide;

[0032] The multistage microspheres are prepared by mixing and reacting the zinc sulfide diatomite compound and n-octadecyl phosphate.

[0033] Further, the stirring reaction conditions of the diatomite and 10wt% hydrochloric acid solution include a reaction temperature of 70-80℃ and a reaction time of 2-4h.

[0034] Further, the high-temperature calcination conditions include a calcination temperature of 800-850℃ and a calcination time of 2-3h.

[0035] Further, the weight ratio of the activated diatomite, zinc nitrate dihydrate, triethylamine, hexamethylenetetramine and zinc nitrate hexahydrate is 50:1.8-2.2:1.2-1.4:1.4-1.6:2.9-3.3.

[0036] Further, the mixing reaction conditions of the diatomite intermediate and the growth solution include incubation at 90-100℃ for 3h, and then cooling to 25℃ for 10-12h.

[0037] Further, the weight ratio of the zinc oxide diatomite compound and sodium sulfide is 1.8-2.2:5.9-6.3.

[0038] Further, the mixing reaction conditions of the zinc oxide diatomite compound and sodium sulfide include a reaction temperature of 75-85℃ and a reaction time of 2-3h.

[0039] Further, the weight ratio of the zinc sulfide diatomite compound and n-octadecyl phosphate is 50:0.25-0.45.

[0040] Further, the mixing reaction conditions of the zinc sulfide diatomite compound and n-octadecyl phosphate include ultrasonic treatment at a power of 400W for 60min, and then heat treatment at 100-120℃ for 30-60min.

[0041] Further, the weight ratio of the hyperbranched polyurethane, ethyl acetate, propylene glycol methyl ether acetate, dimethicone, octadecyl isocyanate, multistage microspheres, Isopar G, isophorone diisocyanate, silane coupling agent KH-560, dibutyltin dilaurate and triethylenediamine is 65-75:20-30:14-16:2-4:0.7-0.9:4-6:9-11:2.6-3.0:0.6-0.8:0.03-0.05:0.07-0.09.

[0042] Compared with the prior art, the present application has the following beneficial effects:

[0043] (1) In the present application, the activated diatomite is obtained by acid treatment and high-temperature calcination treatment of diatomite, the activated diatomite is sequentially immersed in a mixed solution and a growth solution and subjected to hydrothermal reaction to load columnar zinc oxide on the surface of the activated diatomite to obtain a zinc oxide diatomite composite, after treatment with sodium sulfide, the zinc oxide is converted into zinc sulfide to obtain a zinc sulfide diatomite composite, the phosphoric acid group of n-octadecyl phosphate is combined with the zinc ion on the surface of the zinc sulfide diatomite composite by coordination to obtain a multi-level microsphere; a first intermediate is obtained by borate ester exchange reaction of 3,4-dihydroxybenzoic acid and allyl borate pinacol ester, a second intermediate is obtained by esterification reaction of the first intermediate and hydroxyethyl methacrylate, and a modified borate ester is obtained by thiol-olefin click reaction of the second intermediate and β-mercaptoethanol; a first intermediate system is obtained by reaction of trimethylolpropane and isophorone diisocyanate, a second intermediate system is obtained by reaction of the hydroxyl group of the modified borate ester and the isocyanate group of the first intermediate system, and a hyperbranched polyurethane is obtained by reaction of the hydroxyl-terminated polydimethylsiloxane and the residual isocyanate group in the second intermediate system.

[0044] (2) The environmentally friendly fluorine-free superhydrophobic coating material prepared in the present application has good superhydrophobic performance, which is due to the synergistic effect of the multi-level microspheres and the hyperbranched polyurethane: the dandelion-shaped multi-level microspheres are composed of zinc sulfide diatomite composite and n-octadecyl phosphate, and the unique layered rough structure on the surface provides a physical basis for superhydrophobic performance, the stable skeleton of the zinc sulfide diatomite composite ensures the persistence of the rough structure, and the n-octadecyl phosphate endows the material with low surface energy characteristics; the high-elasticity and flexible network structure formed by the hyperbranched polyurethane further enhances the mechanical stability of the coating as a whole, so that the coating can still maintain stable superhydrophobic state after long-term use, effectively resisting the damage of the external environment to the hydrophobic performance.

[0045] (3) The environmentally friendly fluorine-free superhydrophobic coating material prepared in the present application has good self-repairing function, prolonging the service life, the modified borate ester introduced in the hyperbranched polyurethane contains a dynamic borate ester bond, which can undergo exchange reaction under external stimulus: heat treatment can cause the reversible dissociation of the borate ester bond, and the dissociated o-diphenol structure can automatically oxidize and polymerize at the wear interface to form a repair layer, this mechanism enables the coating to restore its original superhydrophobic performance and complete structure after multiple damages, greatly reducing the performance failure problem caused by damage, and significantly prolonging the service life of the coating.

[0046] (4) The environmentally friendly fluorine-free superhydrophobic coating material prepared in the present application has good wear resistance, the high elasticity and flexibility of the hyperbranched polyurethane network, combined with the skeleton supporting effect of the dandelion-shaped multi-level microspheres, effectively improve the anti-wear ability of the coating, ensure that it is not easy to fail due to mechanical action in actual use, and further ensure the long-term performance. DETAILED DESCRIPTION

[0047] The technical solution of the present invention will be clearly and completely described below through embodiments. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] Unless otherwise stated, all raw materials and reagents used in this invention are commercially available or can be prepared by known methods.

[0049] Preparation Example 1:

[0050] The preparation method of hyperbranched polyurethane includes the following steps:

[0051] 4.1 parts by weight of 3,4-dihydroxybenzoic acid and 5.7 parts by weight of allyl borate pinacol ester were dispersed in 50 parts by weight of THF. The mixture was stirred and reacted at 60°C for 4 hours under argon protection. After the reaction was completed, THF was removed by rotary evaporation and the mixture was dried under vacuum at 50°C for 8 hours to obtain the first intermediate.

[0052] 7 parts by weight of the first intermediate, 5 parts by weight of hydroxyethyl methacrylate, 8 parts by weight of EDC and 4 parts by weight of DMAP were dispersed in 100 parts by weight of DMSO and stirred at 23°C for 24 hours. After the reaction was completed, the DMSO was removed by rotary evaporation, and the second intermediate was obtained by lyophilization after dialysis with deionized water for 2 days.

[0053] 5 parts by weight of the second intermediate, 2.5 parts by weight of β-mercaptoethanol, and 0.05 parts by weight of 2,2-dimethoxy-phenylacetophenone were dispersed in 20 parts by weight of anhydrous ethanol, and the mixture was subjected to nitrogen protection at 50 mW / cm⁻¹. 2 The mixture was irradiated with a 395nm LED light source for 30 min. After the reaction was completed, the ethanol was removed by rotary evaporation. The mixture was washed with deionized water until neutral and then distilled under reduced pressure to obtain the modified borate ester.

[0054] 5.5 parts by weight of trimethylolpropane, 3 parts by weight of dimethylolpropionic acid and 20 parts by weight of isophorone diisocyanate were dispersed in 100 parts by weight of acetone and stirred at 300 r / min at 60 °C for 30 min under nitrogen protection. Then 0.015 parts by weight of dibutyltin diacetate were added and the reaction was continued for 3 h to obtain the first intermediate system.

[0055] The first intermediate system was cooled to 50°C, and 6 parts by weight of modified borate ester were added and stirred for 2 hours to obtain the second intermediate system.

[0056] 6.5 parts by weight of hydroxyl-terminated polydimethylsiloxane were added to the second intermediate system above. After stirring and reacting for 3 hours, the temperature was lowered to 40°C, 2 parts by weight of triethylamine were added and stirred for 30 minutes. Then, 140 parts by weight of deionized water were added and emulsified at 12000 r / min for 40 minutes. After the reaction was completed, acetone was removed by rotary evaporation to obtain hyperbranched polyurethane.

[0057] Preparation Example 2:

[0058] The preparation method of hyperbranched polyurethane includes the following steps:

[0059] 4.2 parts by weight of 3,4-dihydroxybenzoic acid and 5.8 parts by weight of allyl borate pinacol ester were dispersed in 50 parts by weight of THF and reacted at 62°C for 4.5 h under argon protection. After the reaction was completed, THF was removed by rotary evaporation and the product was dried under vacuum at 50°C for 8 h to obtain the first intermediate.

[0060] 7.5 parts by weight of the first intermediate, 5.5 parts by weight of hydroxyethyl methacrylate, 8.5 parts by weight of EDC and 4.5 parts by weight of DMAP were dispersed in 100 parts by weight of DMSO and stirred at 23.5°C for 30 h. After the reaction was completed, the DMSO was removed by rotary evaporation, and the second intermediate was obtained by lyophilization after dialysis with deionized water for 2 days.

[0061] 5.5 parts by weight of the second intermediate, 2.7 parts by weight of β-mercaptoethanol, and 0.06 parts by weight of 2,2-dimethoxy-phenylacetophenone were dispersed in 20 parts by weight of anhydrous ethanol and subjected to nitrogen protection at 55 mW / cm⁻¹. 2 The mixture was irradiated with a 395nm LED light source for 35 minutes. After the reaction was completed, the ethanol was removed by rotary evaporation. The mixture was washed with deionized water until neutral and then distilled under reduced pressure to obtain the modified borate ester.

[0062] 6 parts by weight of trimethylolpropane, 3.5 parts by weight of dimethylolpropionic acid and 21 parts by weight of isophorone diisocyanate were dispersed in 100 parts by weight of acetone and stirred at 300 r / min at 62 °C for 30 min under nitrogen protection. Then 0.018 parts by weight of dibutyltin diacetate were added and the reaction was continued for 3.5 h to obtain the first intermediate system.

[0063] The first intermediate system was cooled to 53°C, and 6.5 parts by weight of modified borate ester were added and stirred for 2.5 hours to obtain the second intermediate system.

[0064] Seven parts by weight of hydroxyl-terminated polydimethylsiloxane were added to the second intermediate system above. After stirring and reacting for 3.5 h, the temperature was lowered to 40 °C, and 2.5 parts by weight of triethylamine were added and stirred for 35 min. Then, 145 parts by weight of deionized water were added, and the mixture was emulsified at 12000 r / min for 45 min. After the reaction was completed, acetone was removed by rotary evaporation to obtain hyperbranched polyurethane.

[0065] Preparation Example 3:

[0066] The preparation method of hyperbranched polyurethane includes the following steps:

[0067] 4.3 parts by weight of 3,4-dihydroxybenzoic acid and 5.9 parts by weight of allyl borate pinacol ester were dispersed in 50 parts by weight of THF. The mixture was stirred and reacted at 65°C for 5 hours under argon protection. After the reaction was completed, THF was removed by rotary evaporation and the mixture was dried under vacuum at 50°C for 8 hours to obtain the first intermediate.

[0068] 8 parts by weight of the first intermediate, 6 parts by weight of hydroxyethyl methacrylate, 9 parts by weight of EDC and 5 parts by weight of DMAP were dispersed in 100 parts by weight of DMSO and stirred at 24.5℃ for 36 h. After the reaction was completed, the DMSO was removed by rotary evaporation, and the second intermediate was obtained by lyophilization after dialysis with deionized water for 2 days.

[0069] Six parts by weight of the second intermediate, three parts by weight of β-mercaptoethanol, and 0.07 parts by weight of 2,2-dimethoxy-phenylacetophenone were dispersed in 20 parts by weight of anhydrous ethanol and, under nitrogen protection, were reacted with 60 mW / cm³. 2 The mixture was irradiated with a 395nm LED light source for 40 min. After the reaction was completed, the ethanol was removed by rotary evaporation. The mixture was washed with deionized water until neutral and then distilled under reduced pressure to obtain the modified borate ester.

[0070] 6.5 parts by weight of trimethylolpropane, 4 parts by weight of dimethylolpropionic acid and 22 parts by weight of isophorone diisocyanate were dispersed in 100 parts by weight of acetone and stirred at 300 r / min at 65 °C for 30 min under nitrogen protection. Then 0.02 parts by weight of dibutyltin diacetate was added and the reaction was continued for 4 h to obtain the first intermediate system.

[0071] The first intermediate system was cooled to 55°C, and 7 parts by weight of modified borate ester were added and stirred for 3 hours to obtain the second intermediate system.

[0072] 7.5 parts by weight of hydroxyl-terminated polydimethylsiloxane were added to the second intermediate system above. After stirring and reacting for 4 hours, the temperature was lowered to 40°C, 3 parts by weight of triethylamine were added and stirred for 40 minutes. Then, 150 parts by weight of deionized water were added and emulsified at 12000 r / min for 50 minutes. After the reaction was completed, acetone was removed by rotary evaporation to obtain hyperbranched polyurethane.

[0073] Preparation Example 4:

[0074] The preparation method of hyperbranched polyurethane includes the following steps:

[0075] 4.4 parts by weight of 3,4-dihydroxybenzoic acid and 6.0 parts by weight of allyl borate pinacol ester were dispersed in 50 parts by weight of THF and stirred at 67°C for 5.5 h under argon protection. After the reaction was completed, THF was removed by rotary evaporation and the product was dried under vacuum at 50°C for 8 h to obtain the first intermediate.

[0076] 8.5 parts by weight of the first intermediate, 6.5 parts by weight of hydroxyethyl methacrylate, 9.5 parts by weight of EDC and 5.5 parts by weight of DMAP were dispersed in 100 parts by weight of DMSO and stirred at 24°C for 42 h. After the reaction was completed, the DMSO was removed by rotary evaporation, and the second intermediate was obtained by lyophilization after dialysis with deionized water for 2 days.

[0077] 6.5 parts by weight of the second intermediate, 3.2 parts by weight of β-mercaptoethanol, and 0.08 parts by weight of 2,2-dimethoxy-phenylacetophenone were dispersed in 20 parts by weight of anhydrous ethanol and subjected to nitrogen protection at 70 mW / cm⁻¹. 2 The mixture was irradiated with a 395nm LED light source for 45 minutes. After the reaction was completed, the ethanol was removed by rotary evaporation. The mixture was washed with deionized water until neutral and then distilled under reduced pressure to obtain the modified borate ester.

[0078] 7 parts by weight of trimethylolpropane, 4.5 parts by weight of dimethylolpropionic acid and 24 parts by weight of isophorone diisocyanate were dispersed in 100 parts by weight of acetone and stirred at 300 r / min at 68 °C for 30 min under nitrogen protection. Then 0.025 parts by weight of dibutyltin diacetate was added and the reaction was continued for 4.5 h to obtain the first intermediate system.

[0079] The first intermediate system was cooled to 58°C, and 7.5 parts by weight of modified borate ester were added and stirred for 3.5 hours to obtain the second intermediate system.

[0080] Eight parts by weight of hydroxyl-terminated polydimethylsiloxane were added to the second intermediate system above. After stirring and reacting for 4.5 h, the temperature was lowered to 40 °C, and 3.5 parts by weight of triethylamine were added and stirred for 50 min. Then, 155 parts by weight of deionized water were added, and the mixture was emulsified at 12000 r / min for 55 min. After the reaction was completed, acetone was removed by rotary evaporation to obtain hyperbranched polyurethane.

[0081] Preparation Example 5:

[0082] The preparation method of hyperbranched polyurethane includes the following steps:

[0083] 4.5 parts by weight of 3,4-dihydroxybenzoic acid and 6.1 parts by weight of pinacol ester of allyl borate were dispersed in 50 parts by weight of THF. The mixture was stirred and reacted at 70°C for 6 hours under argon protection. After the reaction was completed, THF was removed by rotary evaporation and the mixture was dried under vacuum at 50°C for 8 hours to obtain the first intermediate.

[0084] Nine parts by weight of the first intermediate, seven parts by weight of hydroxyethyl methacrylate, ten parts by weight of EDC and six parts by weight of DMAP were dispersed in 100 parts by weight of DMSO and stirred at 25°C for 48 hours. After the reaction was completed, the DMSO was removed by rotary evaporation, and the second intermediate was obtained by lyophilization after dialysis with deionized water for two days.

[0085] 7 parts by weight of the second intermediate, 3.5 parts by weight of β-mercaptoethanol, and 0.1 parts by weight of 2,2-dimethoxy-phenylacetophenone were dispersed in 20 parts by weight of anhydrous ethanol and, under nitrogen protection, were subjected to an oxidation reaction at 80 mW / cm³. 2 The mixture was irradiated with a 395nm LED light source for 50 min. After the reaction was completed, the ethanol was removed by rotary evaporation. The mixture was washed with deionized water until neutral and then distilled under reduced pressure to obtain the modified borate ester.

[0086] 7.5 parts by weight of trimethylolpropane, 5 parts by weight of dimethylolpropionic acid and 25 parts by weight of isophorone diisocyanate were dispersed in 100 parts by weight of acetone and stirred at 70°C at 300 r / min for 30 min under nitrogen protection. Then, 0.03 parts by weight of dibutyltin diacetate was added and the reaction was continued for 5 h to obtain the first intermediate system.

[0087] The first intermediate system was cooled to 60°C, and 8 parts by weight of modified borate ester were added and stirred for 4 hours to obtain the second intermediate system.

[0088] 8.5 parts by weight of hydroxyl-terminated polydimethylsiloxane were added to the second intermediate system above. After stirring and reacting for 5 hours, the temperature was lowered to 40°C, 4 parts by weight of triethylamine were added and stirred for 60 minutes. Then, 160 parts by weight of deionized water were added and emulsified at 12000 r / min for 60 minutes. After the reaction was completed, acetone was removed by rotary evaporation to obtain hyperbranched polyurethane.

[0089] Preparation Example 6:

[0090] The preparation method of hyperbranched polyurethane includes the following steps:

[0091] The modified borate ester in Preparation Example 5 was removed, and all other operations were the same as in Preparation Example 5.

[0092] Preparation Example 7:

[0093] The preparation method of modified polyurethane includes the following steps:

[0094] 4.5 parts by weight of 3,4-dihydroxybenzoic acid and 6.1 parts by weight of pinacol phenylboronic acid were dispersed in 50 parts by weight of THF. The mixture was stirred and reacted at 70°C for 6 hours under argon protection. After the reaction was completed, THF was removed by rotary evaporation and the mixture was dried under vacuum at 50°C for 8 hours to obtain the first intermediate.

[0095] Nine parts by weight of the first intermediate, seven parts by weight of hydroxyethyl methacrylate, ten parts by weight of EDC and six parts by weight of DMAP were dispersed in 100 parts by weight of DMSO and stirred at 25°C for 48 hours. After the reaction was completed, the DMSO was removed by rotary evaporation, and the second intermediate was obtained by lyophilization after dialysis with deionized water for two days.

[0096] 7 parts by weight of the second intermediate, 3.5 parts by weight of β-mercaptoethanol and 0.1 parts by weight of 2,2-dimethoxy-phenylacetophenone were dispersed in 20 parts by weight of anhydrous ethanol. The mixture was treated with a 395nm LED light source at 80mW / cm2 for 50min under nitrogen protection. After the reaction was completed, the ethanol was removed by rotary evaporation. The mixture was washed with deionized water until neutral and then distilled under reduced pressure to obtain the modified borate ester.

[0097] 7.5 parts by weight of trimethylolpropane, 5 parts by weight of dimethylolpropionic acid and 25 parts by weight of isophorone diisocyanate were dispersed in 100 parts by weight of acetone and stirred at 70°C at 300 r / min for 30 min under nitrogen protection. Then, 0.03 parts by weight of dibutyltin diacetate was added and the reaction was continued for 5 h to obtain the first intermediate system.

[0098] The first intermediate system was cooled to 60°C, and 8 parts by weight of modified borate ester were added and stirred for 4 hours to obtain the second intermediate system. 4 parts by weight of triethylamine were added and stirred for 60 minutes. 160 parts by weight of deionized water were added and emulsified at 12000 r / min for 60 minutes. After the reaction was completed, acetone was removed by rotary evaporation to obtain the modified polyurethane.

[0099] Preparation Example 8:

[0100] The preparation method of multi-level microspheres includes the following steps:

[0101] 20 parts by weight of diatomaceous earth were dispersed in 200 parts by weight of 10 wt% hydrochloric acid solution and stirred at 70°C for 2 hours. After the reaction was completed, the mixture was filtered, washed with deionized water until neutral, and then placed in a muffle furnace and heated to 800°C at a heating rate of 5°C / min for 2 hours to obtain activated diatomaceous earth.

[0102] 1.8 parts by weight of zinc nitrate dihydrate were dispersed in 100 parts by weight of isopropanol. After stirring and dispersing at 85°C for 15 min, 1.2 parts by weight of triethylamine were added. After stirring for another 15 min, the mixture was cooled to 23°C and allowed to stand for 3 h to obtain a mixed solution.

[0103] 1.4 parts by weight of hexamethylenetetramine and 2.9 parts by weight of zinc nitrate hexahydrate were dispersed in 100 parts by weight of deionized water and stirred at 25°C for 20 min to obtain the growth solution;

[0104] 50 parts by weight of activated diatomaceous earth were dispersed in the above mixture, soaked for 5 minutes, washed several times with ethanol, dried in an oven at 120°C for 1 hour, and then allowed to stand at 25°C for 24 hours to obtain the diatomaceous earth intermediate.

[0105] The above-mentioned diatomaceous earth intermediate and growth solution were mixed and transferred to a high-temperature reactor lined with polytetrafluoroethylene. After being kept at 90°C for 3 hours, the mixture was cooled to 25°C and allowed to stand for 10 hours. After being washed alternately with deionized water and anhydrous ethanol, the mixture was dried under vacuum at 75°C for 8 hours to obtain the zinc oxide diatomaceous earth composite.

[0106] 1.8 parts by weight of zinc oxide diatomite composite and 5.9 parts by weight of sodium sulfide were dispersed in 50 parts by weight of deionized water. After ultrasonic dispersion for 10 min, the mixture was stirred and reacted at 75 °C for 2 h under nitrogen protection. After the reaction was completed, the mixture was filtered, washed and vacuum dried to obtain zinc sulfide diatomite composite.

[0107] 50 parts by weight of zinc sulfide diatomaceous earth composite and 0.25 parts by weight of n-octadecyl phosphate were dispersed in 500 parts by weight of ethanol and ultrasonically treated with 400W power for 60 min. The solid was collected by centrifugation, washed several times with ethanol, and then heat-treated at 100℃ for 30 min to prepare multi-level microspheres.

[0108] Preparation Example 9:

[0109] The preparation method of multi-level microspheres includes the following steps:

[0110] 20 parts by weight of diatomaceous earth were dispersed in 200 parts by weight of 10 wt% hydrochloric acid solution and stirred at 72°C for 2.5 h. After the reaction was completed, the mixture was filtered, washed with deionized water until neutral, and then placed in a muffle furnace and heated to 810°C at a heating rate of 5°C / min for 2.2 h to obtain activated diatomaceous earth.

[0111] 1.9 parts by weight of zinc nitrate dihydrate were dispersed in 100 parts by weight of isopropanol. After stirring and dispersing at 85°C for 15 min, 1.25 parts by weight of triethylamine were added. After stirring for another 15 min, the mixture was cooled to 24°C and allowed to stand for 3 h to obtain a mixed solution.

[0112] 1.45 parts by weight of hexamethylenetetramine and 3.0 parts by weight of zinc nitrate hexahydrate were dispersed in 100 parts by weight of deionized water and stirred at 25°C for 20 min to obtain the growth solution;

[0113] 50 parts by weight of activated diatomaceous earth were dispersed in the above mixture, soaked for 7 min, washed several times with ethanol, dried in an oven at 120℃ for 1 h, and then allowed to stand at 25℃ for 24 h to obtain the diatomaceous earth intermediate.

[0114] The above-mentioned diatomaceous earth intermediate and growth solution were mixed and transferred to a high-temperature reactor lined with polytetrafluoroethylene. After being kept at 92°C for 3 hours, the mixture was cooled to 25°C and allowed to stand for 10 hours. After being washed alternately with deionized water and anhydrous ethanol, the mixture was dried under vacuum at 75°C for 8 hours to obtain the zinc oxide diatomaceous earth composite.

[0115] 1.9 parts by weight of zinc oxide diatomite composite and 6.0 parts by weight of sodium sulfide were dispersed in 50 parts by weight of deionized water. After ultrasonic dispersion for 12 min, the mixture was stirred and reacted at 77 °C for 2.2 h under nitrogen protection. After the reaction was completed, the mixture was filtered, washed and vacuum dried to obtain zinc sulfide diatomite composite.

[0116] 50 parts by weight of zinc sulfide diatomaceous earth composite and 0.3 parts by weight of n-octadecyl phosphate were dispersed in 500 parts by weight of ethanol and ultrasonically treated with 400W power for 60 min. The solid was collected by centrifugation, washed several times with ethanol, and then heat-treated at 105℃ for 35 min to prepare multi-level microspheres.

[0117] Preparation Example 10:

[0118] The preparation method of multi-level microspheres includes the following steps:

[0119] 20 parts by weight of diatomaceous earth were dispersed in 200 parts by weight of 10 wt% hydrochloric acid solution and stirred at 75°C for 3 hours. After the reaction was completed, the mixture was filtered, washed with deionized water until neutral, and then placed in a muffle furnace and heated to 820°C at a heating rate of 5°C / min for 2.5 hours to obtain activated diatomaceous earth.

[0120] 2.0 parts by weight of zinc nitrate dihydrate were dispersed in 100 parts by weight of isopropanol. After stirring and dispersing at 85°C for 15 min, 1.3 parts by weight of triethylamine were added, and stirring was continued for 15 min. The mixture was then cooled to 23°C and allowed to stand for 3 h to obtain the mixture.

[0121] 1.5 parts by weight of hexamethylenetetramine and 3.1 parts by weight of zinc nitrate hexahydrate were dispersed in 100 parts by weight of deionized water and stirred at 25°C for 20 min to obtain the growth solution;

[0122] 50 parts by weight of activated diatomaceous earth were dispersed in the above mixture, soaked for 10 min, washed several times with ethanol, dried in an oven at 120℃ for 1 h, and then allowed to stand at 25℃ for 24 h to obtain the diatomaceous earth intermediate.

[0123] The above-mentioned diatomaceous earth intermediate and growth solution were mixed and transferred to a high-temperature reactor lined with polytetrafluoroethylene. After being kept at 95°C for 3 hours, the mixture was cooled to 25°C and allowed to stand for 10 hours. After being washed alternately with deionized water and anhydrous ethanol, the mixture was dried under vacuum at 75°C for 8 hours to obtain the zinc oxide diatomaceous earth composite.

[0124] 2.0 parts by weight of zinc oxide diatomite composite and 6.1 parts by weight of sodium sulfide were dispersed in 50 parts by weight of deionized water. After ultrasonic dispersion for 15 min, the mixture was stirred and reacted at 80 °C for 2.5 h under nitrogen protection. After the reaction was completed, the mixture was filtered, washed and vacuum dried to obtain zinc sulfide diatomite composite.

[0125] 50 parts by weight of zinc sulfide diatomaceous earth composite and 0.35 parts by weight of n-octadecyl phosphate were dispersed in 500 parts by weight of ethanol and ultrasonically treated with 400W power for 60 min. The solid was collected by centrifugation, washed several times with ethanol, and then heat-treated at 110℃ for 40 min to prepare multi-level microspheres.

[0126] Preparation Example 11:

[0127] The preparation method of multi-level microspheres includes the following steps:

[0128] 20 parts by weight of diatomaceous earth were dispersed in 200 parts by weight of 10 wt% hydrochloric acid solution and stirred at 77°C for 3.5 h. After the reaction was completed, the mixture was filtered, washed with deionized water until neutral, and then placed in a muffle furnace and heated to 830°C at a heating rate of 5°C / min for 2.7 h to obtain activated diatomaceous earth.

[0129] 2.1 parts by weight of zinc nitrate dihydrate were dispersed in 100 parts by weight of isopropanol. After stirring and dispersing at 85°C for 15 min, 1.35 parts by weight of triethylamine were added. After stirring for another 15 min, the mixture was cooled to 24°C and allowed to stand for 3 h to obtain a mixed solution.

[0130] 1.55 parts by weight of hexamethylenetetramine and 3.2 parts by weight of zinc nitrate hexahydrate were dispersed in 100 parts by weight of deionized water and stirred at 25°C for 20 min to obtain the growth solution;

[0131] 50 parts by weight of activated diatomaceous earth were dispersed in the above mixture, soaked for 12 min, washed several times with ethanol, dried in an oven at 120℃ for 1 h, and then allowed to stand at 25℃ for 24 h to obtain diatomaceous earth intermediate.

[0132] The above-mentioned diatomaceous earth intermediate and growth solution were mixed and transferred to a high-temperature reactor lined with polytetrafluoroethylene. After being kept at 98°C for 3 hours, the mixture was cooled to 25°C and allowed to stand for 10 hours. After being washed alternately with deionized water and anhydrous ethanol, the mixture was dried under vacuum at 75°C for 8 hours to obtain the zinc oxide diatomaceous earth composite.

[0133] 2.1 parts by weight of zinc oxide diatomite composite and 6.2 parts by weight of sodium sulfide were dispersed in 50 parts by weight of deionized water. After ultrasonic dispersion for 18 min, the mixture was stirred and reacted at 82 °C for 2.7 h under nitrogen protection. After the reaction was completed, the mixture was filtered, washed and vacuum dried to obtain zinc sulfide diatomite composite.

[0134] 50 parts by weight of zinc sulfide diatomaceous earth composite and 0.40 parts by weight of n-octadecyl phosphate were dispersed in 500 parts by weight of ethanol and ultrasonically treated with 400W power for 60 min. The solid was collected by centrifugation, washed several times with ethanol, and then heat-treated at 115℃ for 50 min to prepare multi-level microspheres.

[0135] Preparation Example 12:

[0136] The preparation method of multi-level microspheres includes the following steps:

[0137] 20 parts by weight of diatomaceous earth were dispersed in 200 parts by weight of 10 wt% hydrochloric acid solution and stirred at 80°C for 4 hours. After the reaction was completed, the mixture was filtered, washed with deionized water until neutral, and then placed in a muffle furnace and heated to 850°C at a heating rate of 5°C / min for 3 hours to obtain activated diatomaceous earth.

[0138] 2.2 parts by weight of zinc nitrate dihydrate were dispersed in 100 parts by weight of isopropanol. After stirring and dispersing at 85°C for 15 min, 1.4 parts by weight of triethylamine were added, and stirring was continued for 15 min. The mixture was then cooled to 25°C and allowed to stand for 3 h to obtain the mixture.

[0139] 1.6 parts by weight of hexamethylenetetramine and 3.3 parts by weight of zinc nitrate hexahydrate were dispersed in 100 parts by weight of deionized water and stirred at 25°C for 20 min to obtain the growth solution;

[0140] 50 parts by weight of activated diatomaceous earth were dispersed in the above mixture, soaked for 15 min, washed several times with ethanol, dried in an oven at 120℃ for 1 h, and then allowed to stand at 25℃ for 24 h to obtain the diatomaceous earth intermediate.

[0141] The above-mentioned diatomaceous earth intermediate and growth solution were mixed and transferred to a high-temperature reactor lined with polytetrafluoroethylene. After being kept at 100°C for 3 hours, the mixture was cooled to 25°C and allowed to stand for 10 hours. After being washed alternately with deionized water and anhydrous ethanol, the mixture was dried under vacuum at 75°C for 8 hours to obtain the zinc oxide diatomaceous earth composite.

[0142] 2.2 parts by weight of zinc oxide diatomite composite and 6.3 parts by weight of sodium sulfide were dispersed in 50 parts by weight of deionized water. After ultrasonic dispersion for 20 min, the mixture was stirred and reacted at 85 °C for 3 h under nitrogen protection. After the reaction was completed, the mixture was filtered, washed and vacuum dried to obtain zinc sulfide diatomite composite.

[0143] 50 parts by weight of zinc sulfide diatomaceous earth composite and 0.45 parts by weight of n-octadecyl phosphate were dispersed in 500 parts by weight of ethanol and ultrasonically treated with 400W power for 60 min. The solid was collected by centrifugation, washed several times with ethanol, and then heat-treated at 120℃ for 60 min to prepare multi-level microspheres.

[0144] Preparation Example 13:

[0145] The preparation method of multi-level microspheres includes the following steps:

[0146] 20 parts by weight of diatomaceous earth were dispersed in 200 parts by weight of 10 wt% hydrochloric acid solution and stirred at 80°C for 4 hours. After the reaction was completed, the mixture was filtered, washed with deionized water until neutral, and then placed in a muffle furnace and heated to 850°C at a heating rate of 5°C / min for 3 hours to obtain activated diatomaceous earth.

[0147] 2.2 parts by weight of zinc nitrate dihydrate were dispersed in 100 parts by weight of isopropanol. After stirring and dispersing at 85°C for 15 min, 1.4 parts by weight of triethylamine were added, and stirring was continued for 15 min. The mixture was then cooled to 25°C and allowed to stand for 3 h to obtain the mixture.

[0148] 1.6 parts by weight of hexamethylenetetramine and 3.3 parts by weight of zinc nitrate hexahydrate were dispersed in 100 parts by weight of deionized water and stirred at 25°C for 20 min to obtain the growth solution;

[0149] 50 parts by weight of activated diatomaceous earth were dispersed in the above mixture, soaked for 15 min, washed several times with ethanol, dried in an oven at 120℃ for 1 h, and then allowed to stand at 25℃ for 24 h to obtain the diatomaceous earth intermediate.

[0150] The above-mentioned diatomaceous earth intermediate and growth solution were mixed and transferred to a high-temperature reactor lined with polytetrafluoroethylene. After being kept at 100°C for 3 hours, the mixture was cooled to 25°C and allowed to stand for 10 hours. After being washed alternately with deionized water and anhydrous ethanol, the mixture was dried under vacuum at 75°C for 8 hours to obtain the zinc oxide diatomaceous earth composite.

[0151] 2.2 parts by weight of zinc oxide diatomaceous earth composite and 6.3 parts by weight of sodium sulfide were dispersed in 50 parts by weight of deionized water. After ultrasonic dispersion for 20 min, the mixture was stirred and reacted at 85 °C for 3 h under nitrogen protection. After the reaction was completed, the mixture was filtered, washed and vacuum dried to obtain multi-level microspheres.

[0152] Preparation Example 14:

[0153] The preparation method of multi-level microspheres includes the following steps:

[0154] 20 parts by weight of diatomaceous earth were dispersed in 200 parts by weight of 10 wt% hydrochloric acid solution and stirred at 80°C for 4 hours. After the reaction was completed, the mixture was filtered, washed with deionized water until neutral, and then placed in a muffle furnace and heated to 850°C at a heating rate of 5°C / min for 3 hours to obtain activated diatomaceous earth.

[0155] 2.2 parts by weight of zinc nitrate dihydrate were dispersed in 100 parts by weight of isopropanol. After stirring and dispersing at 85°C for 15 min, 1.4 parts by weight of triethylamine were added, and stirring was continued for 15 min. The mixture was then cooled to 25°C and allowed to stand for 3 h to obtain the mixture.

[0156] 1.6 parts by weight of hexamethylenetetramine and 3.3 parts by weight of zinc nitrate hexahydrate were dispersed in 100 parts by weight of deionized water and stirred at 25°C for 20 min to obtain the growth solution;

[0157] 50 parts by weight of activated diatomaceous earth were dispersed in the above mixture, soaked for 15 min, washed several times with ethanol, dried in an oven at 120℃ for 1 h, and then allowed to stand at 25℃ for 24 h to obtain the diatomaceous earth intermediate.

[0158] The above-mentioned diatomaceous earth intermediate and growth solution were mixed and transferred to a high-temperature reactor lined with polytetrafluoroethylene. After being kept at 100°C for 3 hours, the mixture was cooled to 25°C and allowed to stand for 10 hours. After being washed alternately with deionized water and anhydrous ethanol, the mixture was dried under vacuum at 75°C for 8 hours to obtain the zinc oxide diatomaceous earth composite.

[0159] 50 parts by weight of zinc oxide diatomaceous earth composite and 0.45 parts by weight of n-octadecyl phosphate were dispersed in 500 parts by weight of ethanol and ultrasonically treated with 400W power for 60 min. The solid was collected by centrifugation, washed several times with ethanol, and then heat-treated at 120℃ for 60 min to prepare multi-level microspheres.

[0160] Preparation Example 15:

[0161] The preparation method of activated diatomaceous earth includes the following steps:

[0162] 20 parts by weight of diatomaceous earth were dispersed in 200 parts by weight of 10 wt% hydrochloric acid solution and stirred at 80°C for 4 hours. After the reaction was completed, the mixture was filtered, washed with deionized water until neutral, and then placed in a muffle furnace and heated to 850°C at a heating rate of 5°C / min for 3 hours to obtain activated diatomaceous earth.

[0163] Example 1:

[0164] A method for preparing an environmentally friendly, fluorine-free, superhydrophobic coating material includes the following steps:

[0165] 65 parts by weight of the hyperbranched polyurethane prepared in Preparation Example 1, 20 parts by weight of ethyl acetate, and 14 parts by weight of propylene glycol methyl ether acetate were added to a reaction vessel and stirred at 500 r / min for 10 min at 25 °C. Then, 2 parts by weight of polydimethylsiloxane and 0.7 parts by weight of octadecyl isocyanate were added and stirred at 40 °C for 60 min. Then, 4 parts by weight of the hierarchical microspheres prepared in Preparation Example 8 were added and ultrasonically treated at 400 W for 15 min. Then, 9 parts by weight of Isopar G, 2.6 parts by weight of isophorone diisocyanate, 0.6 parts by weight of silane coupling agent KH-560, 0.03 parts by weight of dibutyltin dilaurate, and 0.07 parts by weight of triethylenediamine were added and stirred and dispersed at 2000 r / min for 30 min. Finally, the mixture was passed through a 400-mesh sieve to obtain an environmentally friendly fluorine-free superhydrophobic coating material.

[0166] Example 2:

[0167] A method for preparing an environmentally friendly, fluorine-free, superhydrophobic coating material includes the following steps:

[0168] 67 parts by weight of the hyperbranched polyurethane prepared in Preparation Example 2, 22 parts by weight of ethyl acetate, and 14.5 parts by weight of propylene glycol methyl ether acetate were added to a reaction vessel and stirred at 500 r / min for 12 min at 25 °C. Then, 2.5 parts by weight of polydimethylsiloxane and 0.75 parts by weight of octadecyl isocyanate were added and stirred at 40 °C for 65 min. Then, 4.5 parts by weight of the hierarchical microspheres prepared in Preparation Example 9 were added and ultrasonically treated at 400 W for 17 min. Then, 9.5 parts by weight of Isopar G, 2.7 parts by weight of isophorone diisocyanate, 0.65 parts by weight of silane coupling agent KH-560, 0.035 parts by weight of dibutyltin dilaurate, and 0.075 parts by weight of triethylenediamine were added and stirred and dispersed at 2000 r / min for 35 min. Finally, the mixture was passed through a 400-mesh sieve to obtain an environmentally friendly fluorine-free superhydrophobic coating material.

[0169] Example 3:

[0170] A method for preparing an environmentally friendly, fluorine-free, superhydrophobic coating material includes the following steps:

[0171] 70 parts by weight of the hyperbranched polyurethane prepared in Preparation Example 3, 25 parts by weight of ethyl acetate, and 15 parts by weight of propylene glycol methyl ether acetate were added to a reaction vessel and stirred at 500 r / min for 15 min at 25 °C. Then, 3 parts by weight of polydimethylsiloxane and 0.8 parts by weight of octadecyl isocyanate were added and stirred at 40 °C for 70 min. Finally, 5 parts by weight of the hierarchical microspheres prepared in Preparation Example 10 were added and ultrasonically treated at 400 W for 20 min. Then, 10 parts by weight of Isopar G, 2.8 parts by weight of isophorone diisocyanate, 0.7 parts by weight of silane coupling agent KH-560, 0.04 parts by weight of dibutyltin dilaurate, and 0.08 parts by weight of triethylenediamine were added and stirred and dispersed at 2000 r / min for 40 min. The mixture was then passed through a 400-mesh sieve to obtain an environmentally friendly fluorine-free superhydrophobic coating material.

[0172] Example 4:

[0173] A method for preparing an environmentally friendly, fluorine-free, superhydrophobic coating material includes the following steps:

[0174] 72 parts by weight of the hyperbranched polyurethane prepared in Preparation Example 4, 27 parts by weight of ethyl acetate, and 15.5 parts by weight of propylene glycol methyl ether acetate were added to a reaction vessel and stirred at 500 r / min for 17 min at 25 °C. Then, 3.5 parts by weight of polydimethylsiloxane and 0.85 parts by weight of octadecyl isocyanate were added and stirred at 40 °C for 75 min. Then, 5.5 parts by weight of the hierarchical microspheres prepared in Preparation Example 11 were added and ultrasonically treated at 400 W for 25 min. Then, 10.5 parts by weight of Isopar G, 2.9 parts by weight of isophorone diisocyanate, 0.75 parts by weight of silane coupling agent KH-560, 0.045 parts by weight of dibutyltin dilaurate, and 0.085 parts by weight of triethylenediamine were added and stirred and dispersed at 2000 r / min for 45 min. Finally, the mixture was passed through a 400-mesh sieve to obtain an environmentally friendly fluorine-free superhydrophobic coating material.

[0175] Example 5:

[0176] A method for preparing an environmentally friendly, fluorine-free, superhydrophobic coating material includes the following steps:

[0177] 75 parts by weight of the hyperbranched polyurethane prepared in Preparation Example 5, 30 parts by weight of ethyl acetate, and 16 parts by weight of propylene glycol methyl ether acetate were added to a reaction vessel and stirred at 500 r / min for 20 min at 25 °C. Then, 4 parts by weight of polydimethylsiloxane and 0.9 parts by weight of octadecyl isocyanate were added and stirred at 40 °C for 80 min. Next, 6 parts by weight of the multi-level microspheres prepared in Preparation Example 12 were added and ultrasonically treated at 400 W for 30 min. Then, 11 parts by weight of Isopar G, 3.0 parts by weight of isophorone diisocyanate, 0.8 parts by weight of silane coupling agent KH-560, 0.05 parts by weight of dibutyltin dilaurate, and 0.09 parts by weight of triethylenediamine were added and stirred and dispersed at 2000 r / min for 50 min. Finally, the mixture was passed through a 400-mesh sieve to obtain an environmentally friendly fluorine-free superhydrophobic coating material.

[0178] Comparative Example 1:

[0179] A method for preparing an environmentally friendly, fluorine-free, superhydrophobic coating material includes the following steps:

[0180] The hyperbranched polyurethane prepared in Example 5 was replaced with the hyperbranched polyurethane prepared in Example 6, and all other operations were the same as in Example 5.

[0181] Comparative Example 2:

[0182] A method for preparing an environmentally friendly, fluorine-free, superhydrophobic coating material includes the following steps:

[0183] The hyperbranched polyurethane prepared in Example 5 was replaced with the modified polyurethane prepared in Example 7, and all other operations were the same as in Example 5.

[0184] Comparative Example 3:

[0185] A method for preparing an environmentally friendly, fluorine-free, superhydrophobic coating material includes the following steps:

[0186] Replace the multi-level microspheres prepared in Example 12 of Example 5 with the multi-level microspheres prepared in Example 13, and keep all other operations the same as in Example 5.

[0187] Comparative Example 4:

[0188] A method for preparing an environmentally friendly, fluorine-free, superhydrophobic coating material includes the following steps:

[0189] Replace the multi-level microspheres prepared in Example 12 of Example 5 with the multi-level microspheres prepared in Example 14, and keep all other operations the same as in Example 5.

[0190] Comparative Example 5:

[0191] A method for preparing an environmentally friendly, fluorine-free, superhydrophobic coating material includes the following steps:

[0192] The multi-level microspheres prepared in Example 12 of Example 5 were replaced with the activated diatomaceous earth prepared in Example 15, and other operations were kept the same as in Example 5.

[0193] Comparative Example 6:

[0194] A method for preparing an environmentally friendly, fluorine-free, superhydrophobic coating material includes the following steps:

[0195] The multi-level microspheres prepared in Example 12 with 6 parts by weight in Example 5 were replaced with the multi-level microspheres prepared in Example 12 with 2 parts by weight, and other operations were kept the same as in Example 5.

[0196] Comparative Example 7:

[0197] A method for preparing an environmentally friendly, fluorine-free, superhydrophobic coating material includes the following steps:

[0198] The 6 parts by weight of the multi-level microspheres prepared in Example 12 in Example 5 were replaced with 15 parts by weight of the multi-level microspheres prepared in Example 12, and other operations were kept the same as in Example 5.

[0199] Performance testing:

[0200] The superhydrophobic coating materials prepared in Examples 1-5 and Comparative Examples 1-7 were sprayed onto the surface of a stainless steel substrate and cured naturally at room temperature for 24 hours to obtain a superhydrophobic coating with a thickness of 100 μm. The water contact angle was measured using a contact angle measuring instrument.

[0201] Abrasion resistance test: A 500g weight was used to press the superhydrophobic coatings prepared in Examples 1-5 and Comparative Examples 1-7 onto 600-grit sandpaper. The friction distance was fixed at 20cm each time, which was recorded as one cycle. After 100 cycles, the water contact angle was tested.

[0202] Self-healing test: Scratches of the same length were made on the superhydrophobic coatings prepared in Examples 1-5 and Comparative Examples 1-7, respectively, and they were placed in an environment of 70°C for treatment. The self-healing time was recorded. The test results are shown in Table 1.

[0203] Table 1. Performance Tests of Environmentally Friendly Fluorine-Free Superhydrophobic Coatings

[0204]

[0205]

[0206] According to the test results in Table 1, it can be observed that Examples 1 to 5 of the present invention have good superhydrophobicity, self-healing properties and wear resistance, while the coatings prepared in Comparative Examples 1 to 7 have reduced performance.

[0207] The performance degradation in Comparative Example 1 may be due to the absence of dynamic borate ester bonds and catechol structures, preventing self-healing; the absence of dynamic borate ester bonds may affect its stress dissipation capacity, thus impacting the coating's wear resistance. The performance degradation in Comparative Example 2 may be due to the modified polyurethane lacking a hyperbranched structure, affecting the coating's elasticity and flexibility, leading to decreased wear resistance; reduced molecular chain mobility may prolong the self-healing time. The performance degradation in Comparative Example 3 may be due to the multi-level microspheres not being treated with octadecyl phosphate. Octadecyl phosphate provides low surface energy, and its absence leads to a sharp drop in the water contact angle; high surface energy makes it easier for water to penetrate microcracks, accelerating coating failure and affecting its wear resistance. The performance degradation in Comparative Example 4 may be due to the failure to convert zinc oxide to zinc sulfide. Zinc oxide is prone to hydrolysis in humid environments, damaging the surface. The rough structure and decreased water contact angle are the main reasons for the performance degradation in Comparative Example 5. The lack of zinc oxide or zinc sulfide loading on the diatomaceous earth surface, resulting in the absence of a layered rough structure in the multi-level microspheres, relying solely on the polyurethane matrix, leads to a complete loss of superhydrophobicity. The absence of multi-level microsphere reinforcement reduces wear resistance. While dynamic bonds can repair matrix scratches, they cannot establish a hydrophobic surface. The performance degradation in Comparative Example 6 may be due to insufficient multi-level microsphere usage; an insufficient amount makes it difficult to form a continuous air cushion structure, resulting in inadequate protection of the matrix and thus affecting wear resistance. The performance degradation in Comparative Example 7 may be due to excessive multi-level microsphere usage; excessive microspheres hinder polyurethane cross-linking, reducing coating density and significantly decreasing the contact angle after friction. The aggregation of multi-level microspheres becomes stress concentration points, accelerating coating peeling and reducing wear resistance. Cracks propagate at microsphere aggregation points, reducing self-healing efficiency.

[0208] The embodiments described above provide a detailed explanation of the technical solutions and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Various changes and modifications can be made to the present invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed.

Claims

1. A method for preparing an environmentally friendly fluorine-free superhydrophobic coating material, characterized in that, The preparation method comprises the following steps: The hyperbranched polyurethane, ethyl acetate and propylene glycol methyl ether acetate are mixed for 10-20 min, then polydimethylsiloxane and octadecyl isocyanate are added and mixed for 60-80 min, then the multi-stage microspheres are ultrasonically treated for 15-30 min, then Isopar G, isophorone diisocyanate, silane coupling agent KH-560, dibutyl tin dilaurate and triethylenediamine are added and stirred and dispersed for 30-50 min to obtain the environment-friendly fluorine-free super-hydrophobic coating material. 2.The method of claim 1, wherein the method is characterized by, The preparation method of the hyperbranched polyurethane comprises the following steps: 3,4-dihydroxybenzoic acid and allyl boronic acid pinacol ester are mixed to obtain a first intermediate; The first intermediate, hydroxyethyl methacrylate, EDC and DMAP are mixed to obtain a second intermediate; The second intermediate, beta-mercaptoethanol and 2,2-dimethoxy-phenyl acetophenone are mixed and treated by irradiation of a 395 nm LED light source to obtain a modified borate ester; Trimethylolpropane, dimethylolpropionic acid and isophorone diisocyanate are mixed for 30-50 min, then dibutyl tin diacetate is added and mixed to obtain a first intermediate system; The first intermediate system and the modified borate ester are mixed to obtain a second intermediate system; The second intermediate system and hydroxyl-terminated polydimethylsiloxane are mixed for 3-5 h, then triethylamine is added and mixed for 30-60 min, and then deionized water is added and mixed for 40-60 min to obtain the hyperbranched polyurethane. 3.The method of claim 2, wherein the method further comprises the step of: adding a surfactant to the mixture. The weight ratio of the second intermediate, beta-mercaptoethanol and 2,2-dimethoxy-phenyl acetophenone is 5-7: 2.5～3.5：0.05～0.1。 4.The method of claim 2, wherein the method further comprises the step of: adding a surfactant to the mixture of the step (a). The weight ratio of the trimethylolpropane, dimethylolpropionic acid, isophorone diisocyanate, dibutyl tin diacetate, modified borate ester, hydroxyl-terminated polydimethylsiloxane, triethylamine and deionized water is 5.5-7.5:3-5:20-25:0.015-0.03:6-8:6.5-8.5:2-4:140-160.

5. The preparation method of the environmentally friendly fluorine-free superhydrophobic coating material as described in claim 1, characterized in that, The preparation method of the multi-stage microspheres comprises the following steps: The diatomite and 10wt% hydrochloric acid solution are mixed and stirred and reacted, and then high-temperature calcination is performed to obtain activated diatomite; Zinc nitrate dihydrate and triethylamine are mixed to obtain a mixed solution; Hexamethylenetetramine and zinc nitrate hexahydrate are mixed to obtain a growth solution; The activated diatomite is dispersed in the mixed solution and soaked for 5-15 min to obtain a diatomite intermediate; The diatomite intermediate and the growth solution are mixed and reacted to obtain a zinc oxide diatomite composite; The zinc oxide diatomite composite and sodium sulfide are mixed and reacted to obtain a zinc sulfide diatomite composite; The zinc sulfide diatomite composite and n-octadecyl phosphate are mixed and reacted to obtain the multi-stage microspheres.

6. The method of claim 5, wherein the method is characterized by: The high-temperature calcination conditions include a calcination temperature of 800-850 DEG C and a calcination time of 2-3 h. 7.The method of claim 5, wherein the method further comprises the step of: adding a surfactant to the mixture. The weight ratio of the activated diatomite, zinc nitrate dihydrate, triethylamine, hexamethylenetetramine and zinc nitrate hexahydrate is 50: 1.8～2.2：1.2～1.4：1.4～1.6：2.9～3.3。 8. The method for preparing an environmentally friendly, fluorine-free, superhydrophobic coating material as described in claim 5, characterized in that, The weight ratio of the zinc oxide diatomite composite and sodium sulfide is 1.8-2.2:5.9-6.

3. 9.The method of claim 1, wherein the method is characterized by, The weight ratio of the hyperbranched polyurethane, ethyl acetate, propylene glycol methyl ether acetate, dimethicone, octadecyl isocyanate, multi-stage microspheres, Isopar G, isophorone diisocyanate, silane coupling agent KH-560, dibutyl tin dilaurate and triethylenediamine is 65-75:20-30:14-16:2-4:0.7-0.9:4-6:9-11:2.6-3.0:0.6-0.8:0.03-0.05:0.07-0.

09.

10. An environmentally friendly fluorine-free superhydrophobic coating material, characterized in that, The environmentally-friendly fluorine-free super-hydrophobic coating material is prepared by the method of any one of claims 1-9.

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