An ultra-long weather-resistant anticorrosive precoating paint for steel, a preparation method and application thereof

Abstract

This invention relates to the field of metal material corrosion protection technology, specifically to an ultra-long-lasting weather-resistant anti-corrosion pre-coating for steel, its preparation method, and its application. It solves the problems of poor environmental performance and poor corrosion resistance of existing coatings. This coating uses epoxy resin and silicone-modified epoxy resin as main raw materials, giving it excellent adhesion. The introduction of silicone imparts excellent heat resistance, weather resistance, and hydrophobicity. Adding modified mixed fillers and polyfluorinated reinforcing agents further enhances its chemical stability, heat resistance, weather resistance, and hydrophobicity, resulting in a coating with excellent corrosion resistance, effectively protecting steel. It also exhibits good stability, maintaining good performance even in harsh environments, giving the coating excellent weather resistance. Furthermore, the solvent of this coating is ethanol, which is environmentally friendly and will not pollute the atmosphere.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of metal material corrosion prevention, in particular to a super-long weather-resistant anticorrosive precoating paint for steel materials, a preparation method and application. BACKGROUND

[0002] Steel materials are widely used in the fields of building, bridge, ship, ocean engineering and the like due to excellent mechanical properties and cost-effectiveness. However, the steel materials are prone to electrochemical corrosion in the natural environment, especially in harsh environments such as high temperature, high humidity and high corrosion, and the corrosion problem is particularly serious, which greatly shortens the service life of structural parts and brings huge maintenance costs and safety hazards. At present, the corrosion prevention of steel materials mainly relies on the coating protection in the subsequent process, that is, steel material products (such as steel plates, steel sections and the like) are first produced, and then a plurality of processes such as sand blasting, primer coating, curing and topcoat coating are carried out.

[0003] The traditional solvent-based paint contains a large amount of volatile organic compounds (VOCs), which are emitted into the atmosphere during the curing process, causing pollution, but the corrosion resistance of the coating is poor, and there may be peeling risk in harsh environments, and the coating is prone to aging in long-term use, and the corrosion resistance decays quickly.

[0004] Therefore, it is of great practical significance to develop a super-long weather-resistant anticorrosive precoating paint for steel materials, a preparation method and application.

[0005] In view of the above technical defects, a solution is proposed. SUMMARY

[0006] In order to overcome the above technical problems, the purpose of the present application is to provide a super-long weather-resistant anticorrosive precoating paint for steel materials, a preparation method and application, which solves the problems of poor environmental performance of the existing paint, poor corrosion resistance of the formed coating, peeling risk in harsh environments, and quick decay of the corrosion resistance in long-term use.

[0007] The purpose of the present application can be achieved by the following technical solutions:

[0008] In a first aspect, the present application provides a super-long weather-resistant anticorrosive precoating paint for steel materials, comprising the following components by weight:

[0009] epoxy resin 15-17 parts, organosilicon modified epoxy resin 35-45 parts, modified mixed filler 28-36 parts, multi-fluorine reinforcing agent 1.1-4.7 parts, leveling agent 1-2 parts, defoaming agent 1-2 parts, curing agent 33-36 parts and anhydrous ethanol 20-26 parts;

[0010] The organosilicon modified epoxy resin is prepared by the following steps:

[0011] 3-(2,3-epoxypropoxy) propyl trimethoxysilane, dimethyl diethoxysilane and anhydrous toluene are added into a three-necked flask equipped with a stirrer, a thermometer and a gas inlet pipe, and stirred at a temperature of 20-25℃ and a stirring rate of 200-300r / min for 20-30min under nitrogen protection, then adjusted to pH 4-5 with hydrochloric acid solution, and then continued to stir at a temperature of 60-65℃ for 4-6h, after the reaction is completed, the reaction product is cooled to room temperature, then separated by standing, the organic phase is washed with distilled water for 3-5 times, then dried with anhydrous magnesium sulfate, then vacuum filtered, the filtrate is rotary evaporated to remove the solvent, and the silicone modified epoxy resin is obtained.

[0012] As a preferred embodiment of the present application, the amount ratio of 3-(2,3-epoxypropoxy) propyl trimethoxysilane, dimethyl diethoxysilane and anhydrous toluene is 0.5-2.5g:10g:70-80mL.

[0013] As a preferred embodiment of the present application, the mass fraction of the hydrochloric acid solution is 10-12%.

[0014] As a preferred embodiment of the present application, the modified mixed filler is prepared by the following steps:

[0015] The mixed filler, anhydrous ethanol and deionized water are added into a three-necked flask equipped with a stirrer and a thermometer, and ultrasonic treated at an ultrasonic frequency of 30-40kHz for 1-2h, then 3-glycidyloxypropyl triethoxysilane is added and stirred at a temperature of 20-25℃ and a stirring rate of 200-300r / min for 20-30min, then continued to stir at a temperature of 70-75℃ for 3-5h, after the reaction is completed, the reaction product is cooled to room temperature, then centrifuged, then the precipitate is washed with distilled water for 3-5 times, then placed in a vacuum drying oven and dried at a temperature of 50-55℃ for 5-6h, and the modified mixed filler is obtained.

[0016] As a preferred embodiment of the present application, the amount ratio of the mixed filler, anhydrous ethanol, deionized water and 3-glycidyloxypropyl triethoxysilane is 5g:50-60mL:20-30mL:0.7-2.3g.

[0017] As a preferred embodiment of the present application, the mixed filler is a mixture of glass powder, hexagonal boron nitride and nano silicon dioxide in a mass ratio of 20-35:5-15:3-10.

[0018] As a preferred embodiment of the present application, the glass powder is Amie micro-nano boron glass powder GT35; the hexagonal boron nitride is Dongchaomaterial DCB-10F micro hexagonal boron nitride; and the nano silicon dioxide is nano silicon dioxide HL-200.

[0019] As a preferred embodiment of the present application, the polyfluoro enhancer is prepared by the following steps:

[0020] 3,5-bistrifluoromethyl benzaldehyde, propionic acid and dimethyl sulfoxide are added into a three-necked flask equipped with a stirrer, a thermometer and a gas inlet pipe, and then nitrogen is introduced for protection. The reaction is stirred at a temperature of 20-25°C and a stirring speed of 200-300 r / min for 20-30 min, and then pyrrole is added and the reaction is continued to be stirred at a temperature of 110-120°C for 1-3 h. After the reaction is completed, the reaction product is cooled to room temperature, and then vacuum filtration is performed. The filter cake is washed with distilled water and anhydrous methanol for 3-5 times, and then placed in a vacuum drying oven for drying at a temperature of 60-65°C for 2-3 h to obtain the polyfluoro enhancer.

[0021] As a preferred embodiment of the present application, the amount ratio of 3,5-bistrifluoromethyl benzaldehyde, propionic acid, dimethyl sulfoxide and pyrrole is 1.8-2.2 mL: 35-40 mL: 4-5 mL: 0.8-0.9 mL.

[0022] In a second aspect, the present application provides a preparation method of the super-long weather-resistant anticorrosive pre-coating paint for steel materials according to the first aspect, which comprises the following steps:

[0023] Step one: epoxy resin 15-17 parts, silicone modified epoxy resin 35-45 parts, modified mixed filler 28-36 parts, polyfluoro enhancer 1.1-4.7 parts, leveling agent 1-2 parts, defoaming agent 1-2 parts, curing agent 33-36 parts and anhydrous ethanol 20-26 parts are weighed according to the weight parts, and are prepared for use;

[0024] Step two: the epoxy resin, the silicone modified epoxy resin, the modified mixed filler, the polyfluoro enhancer, the leveling agent, the defoaming agent, the curing agent and the anhydrous ethanol are added into a mixer, and are stirred and mixed at a temperature of 20-25°C and a stirring speed of 1000-2000 r / min for 20-30 min. After that, the mixture is left to stand for 10-15 min to obtain the super-long weather-resistant anticorrosive pre-coating paint for steel materials.

[0025] As a preferred embodiment of the present application, the epoxy resin is epoxy resin E-51.

[0026] As a preferred embodiment of the present application, the leveling agent is TEGO 100 water-based leveling agent.

[0027] As a preferred embodiment of the present application, the defoaming agent is BYK 024 silicone defoaming agent.

[0028] As a preferred embodiment of the present application, the curing agent is isophorone diamine.

[0029] In a third aspect, the application provides a use of the steel ultra-long weather-resistant anticorrosion pre-coating paint prepared by the preparation method of the steel ultra-long weather-resistant anticorrosion pre-coating paint according to the second aspect in metal material corrosion prevention.

[0030] Compared with the prior art, the present application has the following beneficial effects:

[0031] The steel ultra-long weather-resistant anticorrosion pre-coating paint, the preparation method and the application of the present application, by stirring and mixing epoxy resin, silicone modified epoxy resin, modified mixed filler, multi-fluorine reinforcing agent, leveling agent, defoaming agent, curing agent and anhydrous ethanol, and then standing, the steel ultra-long weather-resistant anticorrosion pre-coating paint is obtained; the paint takes epoxy resin and silicone modified epoxy resin as main raw materials, which gives it excellent adhesion, at the same time, the introduction of silicone gives it excellent heat resistance, weather resistance and hydrophobicity, the addition of modified mixed filler can play a remarkable chemical inertness and physical barrier effect, which can effectively prolong the penetration path of corrosion medium, and also improve the hardness, wear resistance and compactness of the coating, the addition of multi-fluorine reinforcing agent can further improve its chemical stability, heat resistance, weather resistance and hydrophobicity, so that the prepared coating has excellent corrosion resistance and can effectively protect the steel, at the same time, it has good stability, so it can still maintain good performance in harsh environments, so that the coating has excellent weather resistance, and the solvent of the paint is ethanol, which has good environmental friendliness and will not pollute the atmosphere.

[0032] In the process of preparing the coating, firstly, a silicone-modified epoxy resin, modified mixed filler and polyfluorinated reinforcing agent are prepared. The silicone-modified epoxy resin is prepared by dehydration condensation of 3-(2,3-epoxypropoxy) propyl trimethoxysilane and dimethyl diethoxysilane to form the silicone-modified epoxy resin containing both silicone groups and epoxy groups. The silicone-modified epoxy resin imparts good heat resistance, weather resistance and hydrophobicity to the coating, and the epoxy groups impart good adhesion to the coating. The mixed filler is modified by 3-glycidyloxypropyl triethoxysilane. The silanol on the 3-glycidyloxypropyl triethoxysilane is hydrolyzed to form silanol grafted to the surface of the mixed filler, and the epoxy groups are introduced at the same time to obtain the modified mixed filler. The glass powder in the mixed filler can act as an inorganic filler and a high-temperature resistant skeleton, and can be slightly softened at high temperature to form a dense ceramic protective layer with the matrix, providing excellent chemical inertness and physical barrier effect. Hexagonal boron nitride is a two-dimensional sheet filler, which can effectively prolong the penetration path of the corrosion medium and impart excellent thermal stability and thermal conductivity to the coating, which is beneficial to the uniform distribution of residual heat. Nano-silicon dioxide fills the micro-pores to improve the density of the coating and enhance the wear resistance and impact resistance of the coating through the "nano effect". The modified nano-silicon dioxide can be uniformly dispersed in the coating to form a dense physical barrier layer. The polyfluorinated reinforcing agent is obtained by reacting 3,5-bistrifluoromethyl benzaldehyde and pyrrole to form a porphyrin structure containing multiple trifluoromethyl groups. The polyfluorinated reinforcing agent can impart excellent stability to the coating by using a large number of fluorine atoms, so that the coating can maintain excellent performance in harsh environments and effectively protect the steel. DETAILED DESCRIPTION

[0033] In order to enable persons skilled in the art to better understand the technical scheme of the present application, the technical scheme in the embodiments of the present application will be described clearly and completely below. Obviously, the described embodiments are only some of the embodiments of the present application, not all. Based on the embodiments in the present application, all other embodiments obtained by persons skilled in the art without creative labor are within the scope of protection of the present application.

[0034] Embodiment 1:

[0035] The present embodiment is a preparation method of an ultra-long weather-resistant anticorrosive precoating for steel, comprising the following steps:

[0036] Step S1: 0.5 g of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 10 g of dimethyldiethoxysilane, and 70 mL of anhydrous toluene were added to a three-neck flask equipped with a stirrer, a thermometer, and a gas inlet tube, protected by nitrogen, stirred at a temperature of 20 DEG C and a stirring rate of 200 r / min for 20 min, then adjusted to pH 4 with a 10% hydrochloric acid solution, and then continued to stir at a temperature of 60 DEG C for 4 h. After the reaction was completed, the reaction product was cooled to room temperature, then allowed to stand and separate into layers, the organic phase was washed with distilled water three times, then dried over anhydrous magnesium sulfate, then vacuum filtered, the filtrate was rotary evaporated to remove the solvent, and an organosilicon modified epoxy resin was obtained;

[0037] Step S2: 5 g of mixed fillers, 50 mL of anhydrous ethanol, and 20 mL of deionized water were added to a three-neck flask equipped with a stirrer and a thermometer, ultrasonically treated at an ultrasonic frequency of 30 kHz for 1 h, then 0.7 g of 3-glycidyloxypropyltriethoxysilane was added and stirred at a temperature of 20 DEG C and a stirring rate of 200 r / min for 20 min, then continued to stir at a temperature of 70 DEG C for 3 h. After the reaction was completed, the reaction product was cooled to room temperature, then centrifuged, then the precipitate was washed with distilled water three times, then placed in a vacuum drying oven and dried at a temperature of 50 DEG C for 5 h to obtain a modified mixed filler. The mixed filler is a mixture of glass powder, hexagonal boron nitride, and nano-silicon dioxide in a mass ratio of 20:5:3. The glass powder is Anmi micro-nano boron glass powder GT35. The hexagonal boron nitride is Dongchao Material DCB-10F micron hexagonal boron nitride. The nano-silicon dioxide is nano-silicon dioxide HL-200;

[0038] Step S3: 1.8 mL of 3,5-bistrifluoromethylbenzaldehyde, 35 mL of propionic acid, and 4 mL of dimethyl sulfoxide were added to a three-neck flask equipped with a stirrer, a thermometer, and a gas inlet tube, protected by nitrogen, stirred at a temperature of 20 DEG C and a stirring rate of 200 r / min for 20 min, then 0.8 mL of pyrrole was added and continued to stir at a temperature of 110 DEG C for 1 h. After the reaction was completed, the reaction product was cooled to room temperature, then vacuum filtered, the filter cake was washed with distilled water and anhydrous methanol three times, then placed in a vacuum drying oven and dried at a temperature of 60 DEG C for 2 h to obtain a multi-fluorine reinforcing agent;

[0039] Step S4: 15 parts by weight of epoxy resin, 35 parts by weight of silicone-modified epoxy resin, 28 parts by weight of modified mixed filler, 1.1 parts by weight of polyfluoro reinforcing agent, 1 part by weight of leveling agent, 1 part by weight of defoaming agent, 33 parts by weight of curing agent and 20 parts by weight of anhydrous ethanol were weighed and prepared for use; the epoxy resin was epoxy resin E-51; the leveling agent was TEGO 100 water-based leveling agent; the defoaming agent was BYK 024 silicone defoaming agent; and the curing agent was isophorone diamine;

[0040] Step S5: The epoxy resin, silicone-modified epoxy resin, modified mixed filler, polyfluoro reinforcing agent, leveling agent, defoaming agent, curing agent and anhydrous ethanol were added to a mixer and stirred and mixed at a temperature of 20°C and a stirring rate of 1000 r / min for 20 min, and then left to stand for 10 min to obtain an ultra-long weather-resistant anticorrosive pre-coating paint for steel.

[0041] Example 2:

[0042] The present embodiment is a preparation method of an ultra-long weather-resistant anticorrosive pre-coating paint for steel, comprising the following steps:

[0043] Step S1: 1.5 g of 3-(2,3-epoxypropoxy)propyl trimethoxysilane, 10 g of dimethyldiethoxysilane and 75 mL of anhydrous toluene were added to a three-necked flask equipped with a stirrer, a thermometer and a gas inlet tube, and protected by nitrogen, and stirred at a temperature of 22°C and a stirring rate of 250 r / min for 25 min, then adjusted to a pH of 4.5 with a 11% by mass hydrochloric acid solution, and then continued to stir at a temperature of 62°C for 5 h. After the reaction was completed, the reaction product was cooled to room temperature, and then left to stand and separate into layers. The organic phase was washed with distilled water 4 times, and then dried with anhydrous magnesium sulfate, and then vacuum filtered. The filtrate was rotary evaporated to remove the solvent, to obtain a silicone-modified epoxy resin;

[0044] Step S2: 5 g of mixed filler, 55 mL of anhydrous ethanol and 25 mL of deionized water were added to a three-necked flask equipped with a stirrer, a thermometer, and an ultrasonic bath, and ultrasonic treatment was carried out at an ultrasonic frequency of 35 kHz for 1.5 h, then 1.5 g of 3-glycidyloxypropyl triethoxysilane was added and stirred at a temperature of 22°C and a stirring rate of 250 r / min for 25 min, then the temperature was raised to 72°C and the stirring was continued for 4 h, after the reaction was completed, the reaction product was cooled to room temperature, then centrifuged, then the precipitate was washed with distilled water for 4 times, then placed in a vacuum drying oven and dried at a temperature of 52°C for 5.5 h to obtain a modified mixed filler; the mixed filler is a mixture of glass powder, hexagonal boron nitride and nano silicon dioxide in a mass ratio of 27:10:7; the glass powder is Anmi micro-nano boron glass powder GT35; the hexagonal boron nitride is Dongchao Material DCB-10F micron hexagonal boron nitride; the nano silicon dioxide is nano silicon dioxide HL-200;

[0045] Step S3: 2.0 mL of 3,5-bistrifluoromethylbenzaldehyde, 38 mL of propionic acid and 4.5 mL of dimethyl sulfoxide were added to a three-necked flask equipped with a stirrer, a thermometer and a gas inlet tube, and protected by nitrogen, stirred at a temperature of 22°C and a stirring rate of 250 r / min for 25 min, then 0.85 mL of pyrrole was added and the temperature was raised to 115°C and the stirring was continued for 2 h, after the reaction was completed, the reaction product was cooled to room temperature, then vacuum filtered, the filter cake was washed with distilled water and anhydrous methanol for 4 times, then placed in a vacuum drying oven and dried at a temperature of 62°C for 2.5 h to obtain a multi-fluorine reinforcing agent;

[0046] Step S4: the epoxy resin 16 parts, the silicone modified epoxy resin 40 parts, the modified mixed filler 32 parts, the multi-fluorine reinforcing agent 2.9 parts, the leveling agent 1.5 parts, the defoaming agent 1.5 parts, the curing agent 35 parts and the anhydrous ethanol 23 parts were weighed according to the weight parts, and were ready for use; the epoxy resin is epoxy resin E-51; the leveling agent is TEGO 100 water-based leveling agent; the defoaming agent is BYK 024 silicone defoaming agent; the curing agent is isophorone diamine;

[0047] Step S5: the epoxy resin, the silicone modified epoxy resin, the modified mixed filler, the multi-fluorine reinforcing agent, the leveling agent, the defoaming agent, the curing agent and the anhydrous ethanol were added to a mixer, stirred and mixed at a temperature of 22°C and a stirring rate of 1500 r / min for 25 min, then stood for 12 min to obtain an ultra-long weather-resistant anticorrosive pre-coating paint for steel.

[0048] Example 3:

[0049] The embodiment is a preparation method of an ultra-long weather-resistant anticorrosive precoating paint for steel materials, including the following steps.

[0050] Step S1: 2.5g 3-(2,3-epoxypropoxy) propyl trimethoxysilane, 10g dimethyl diethoxysilane and 80mL anhydrous toluene are added into a three-necked flask equipped with a stirrer, a thermometer and a gas inlet pipe, nitrogen is introduced for protection, stirring is carried out at a temperature of 25℃ and a stirring rate of 300r / min for 30min, then a hydrochloric acid solution with a mass fraction of 12% is used to adjust the pH to 5, then the reaction is continuously stirred at a temperature of 65℃ for 6h, after the reaction is completed, the reaction product is cooled to room temperature, then it is left to stand and separate, the organic phase is washed with distilled water for 5 times, then it is dried with anhydrous magnesium sulfate, then vacuum filtration is carried out, the filtrate is rotary evaporated to remove the solvent, and a silicone modified epoxy resin is obtained.

[0051] Step S2: 5g mixed fillers, 60mL anhydrous ethanol and 30mL deionized water are added into a three-necked flask equipped with a stirrer and a thermometer, ultrasonic treatment is carried out at an ultrasonic frequency of 40kHz for 2h, then 2.3g 3-glycidyloxypropyl triethoxysilane is added and stirring is carried out at a temperature of 25℃ and a stirring rate of 300r / min for 30min, then the reaction is continuously stirred at a temperature of 75℃ for 5h, after the reaction is completed, the reaction product is cooled to room temperature, then it is centrifuged, then the precipitate is washed with distilled water for 5 times, then it is placed in a vacuum drying oven and dried at a temperature of 55℃ for 6h, and a modified mixed filler is obtained; the mixed filler is a mixture of glass powder, hexagonal boron nitride and nanometer silicon dioxide in a mass ratio of 35:15:10; the glass powder is Anmi micro-nano boron glass powder GT35; the hexagonal boron nitride is Dongchao Material DCB-10F micron hexagonal boron nitride; and the nanometer silicon dioxide is nanometer silicon dioxide HL-200;

[0052] Step S3: 2.2mL 3,5-bistrifluoromethylbenzaldehyde, 40mL propionic acid and 5mL dimethyl sulfoxide are added into a three-necked flask equipped with a stirrer, a thermometer and a gas inlet pipe, nitrogen is introduced for protection, stirring is carried out at a temperature of 25℃ and a stirring rate of 300r / min for 30min, then 0.9mL pyrrole is added and the reaction is continuously stirred at a temperature of 120℃ for 3h, after the reaction is completed, the reaction product is cooled to room temperature, then vacuum filtration is carried out, the filter cake is washed with distilled water and anhydrous methanol for 5 times, then it is placed in a vacuum drying oven and dried at a temperature of 65℃ for 3h, and a polyfluoro reinforcing agent is obtained.

[0053] Step S4: epoxy resin 17 parts, silicone modified epoxy resin 45 parts, modified mixed filler 36 parts, multi-fluorine reinforcing agent 4.7 parts, leveling agent 2 parts, defoaming agent 2 parts, curing agent 36 parts and anhydrous ethanol 26 parts were weighed according to the weight parts, ready for use; the epoxy resin is epoxy resin E-51; the leveling agent is TEGO 100 water-based leveling agent; the defoaming agent is BYK 024 silicone defoaming agent; the curing agent is isophorone diamine;

[0054] Step S5: the epoxy resin, silicone modified epoxy resin, modified mixed filler, multi-fluorine reinforcing agent, leveling agent, defoaming agent, curing agent and anhydrous ethanol were added into the mixer, stirred and mixed under the condition of temperature 25℃ and stirring rate 2000r / min for 30min, and then rested for 15min, to obtain the super-long weather-resistant anticorrosive pre-coating paint for steel.

[0055] Comparative Example 1:

[0056] The present comparative example is a preparation method of a super-long weather-resistant anticorrosive pre-coating paint for steel, comprising the following steps:

[0057] Step S1: epoxy resin 17 parts, leveling agent 2 parts, defoaming agent 2 parts, curing agent 36 parts and anhydrous ethanol 26 parts were weighed according to the weight parts, ready for use; the epoxy resin is epoxy resin E-51; the leveling agent is TEGO 100 water-based leveling agent; the defoaming agent is BYK 024 silicone defoaming agent; the curing agent is isophorone diamine;

[0058] Step S2: the epoxy resin, leveling agent, defoaming agent, curing agent and anhydrous ethanol were added into the mixer, stirred and mixed under the condition of temperature 25℃ and stirring rate 2000r / min for 30min, and then rested for 15min, to obtain the super-long weather-resistant anticorrosive pre-coating paint for steel.

[0059] Comparative Example 2:

[0060] The present comparative example is a preparation method of a super-long weather-resistant anticorrosive pre-coating paint for steel, comprising the following steps:

[0061] Step S1: 5 g of mixed filler, 60 mL of anhydrous ethanol and 30 mL of deionized water were added to a three-necked flask equipped with a stirrer, a thermometer, and an ultrasonic bath, and ultrasonic treatment was carried out for 2 h at an ultrasonic frequency of 40 kHz. Then, 2.3 g of 3-glycidyloxypropyl triethoxysilane was added and stirred for 30 min at a temperature of 25°C and a stirring rate of 300 r / min. Then, the reaction was continued at a temperature of 75°C for 5 h. After the reaction was completed, the reaction product was cooled to room temperature, and then centrifuged. The precipitate was washed with distilled water for 5 times, and then placed in a vacuum drying oven and dried at a temperature of 55°C for 6 h to obtain a modified mixed filler. The mixed filler was a mixture of glass powder, hexagonal boron nitride and nano-silica in a mass ratio of 35:15:10. The glass powder was Anmi micro-nano boron glass powder GT35. The hexagonal boron nitride was Dongchao Material DCB-10F micron hexagonal boron nitride. The nano-silica was nano-silica HL-200;

[0062] Step S2: 2.2 mL of 3,5-bistrifluoromethylbenzaldehyde, 40 mL of propionic acid and 5 mL of dimethyl sulfoxide were added to a three-necked flask equipped with a stirrer, a thermometer and a gas inlet tube, and protected by nitrogen. The mixture was stirred for 30 min at a temperature of 25°C and a stirring rate of 300 r / min. Then, 0.9 mL of pyrrole was added and the reaction was continued at a temperature of 120°C for 3 h. After the reaction was completed, the reaction product was cooled to room temperature, and then vacuum filtered. The filter cake was washed with distilled water and anhydrous methanol for 5 times, and then placed in a vacuum drying oven and dried at a temperature of 65°C for 3 h to obtain a multi-fluorine reinforcing agent.

[0063] Step S3: The following ingredients were weighed in parts by weight: 17 parts of epoxy resin, 36 parts of modified mixed filler, 4.7 parts of multi-fluorine reinforcing agent, 2 parts of leveling agent, 2 parts of defoaming agent, 36 parts of curing agent and 26 parts of anhydrous ethanol, and were ready for use. The epoxy resin was epoxy resin E-51. The leveling agent was TEGO 100 water-based leveling agent. The defoaming agent was BYK 024 silicone defoaming agent. The curing agent was isophorone diamine.

[0064] Step S4: The epoxy resin, modified mixed filler, multi-fluorine reinforcing agent, leveling agent, defoaming agent, curing agent and anhydrous ethanol were added to a mixer and stirred and mixed for 30 min at a temperature of 25°C and a stirring rate of 2000 r / min. Then, it was left to stand for 15 min to obtain a super-long weather-resistant anticorrosive pre-coating paint for steel.

[0065] Comparative Example 3

[0066] This comparative example is a preparation method of a super-long weather-resistant anticorrosive pre-coating paint for steel, which comprises the following steps:

[0067] Step S1: 2.5 g of 3-(2,3-epoxypropoxy)propyl trimethoxysilane, 10 g of dimethyl diethoxysilane and 80 mL of anhydrous toluene were added to a three-necked flask equipped with a stirrer, a thermometer and a gas inlet tube, protected by nitrogen, stirred at a temperature of 25°C and a stirring rate of 300 r / min for 30 min, then adjusted to pH 5 with a 12% hydrochloric acid solution, and then continued to stir at a temperature of 65°C for 6 h. After the reaction was completed, the reaction product was cooled to room temperature, then allowed to stand and separate into layers, the organic phase was washed with distilled water 5 times, then dried with anhydrous magnesium sulfate, then vacuum filtered, the filtrate was rotary evaporated to remove the solvent, and a silicone-modified epoxy resin was obtained;

[0068] Step S2: 2.2 mL of 3,5-bistrifluoromethylbenzaldehyde, 40 mL of propionic acid and 5 mL of dimethyl sulfoxide were added to a three-necked flask equipped with a stirrer, a thermometer and a gas inlet tube, protected by nitrogen, stirred at a temperature of 25°C and a stirring rate of 300 r / min for 30 min, then 0.9 mL of pyrrole was added and the temperature was raised to 120°C, and then continued to stir for 3 h. After the reaction was completed, the reaction product was cooled to room temperature, then vacuum filtered, the filter cake was washed with distilled water and anhydrous methanol 5 times, then placed in a vacuum drying oven and dried at a temperature of 65°C for 3 h, and a polyfluoro enhancer was obtained.

[0069] Step S3: epoxy resin 17 parts, silicone-modified epoxy resin 45 parts, polyfluoro enhancer 4.7 parts, leveling agent 2 parts, defoaming agent 2 parts, curing agent 36 parts and anhydrous ethanol 26 parts were weighed according to weight parts, and used as prepared. The epoxy resin is epoxy resin E-51; the leveling agent is TEGO 100 water-based leveling agent; the defoaming agent is BYK 024 silicone defoaming agent; and the curing agent is isophorone diamine.

[0070] Step S4: the epoxy resin, silicone-modified epoxy resin, polyfluoro enhancer, leveling agent, defoaming agent, curing agent and anhydrous ethanol were added to a mixer, stirred and mixed at a temperature of 25°C and a stirring rate of 2000 r / min for 30 min, then allowed to stand for 15 min, and an ultra-long weather-resistant anticorrosive pre-coating paint for steel was obtained.

[0071] Comparative Example 4

[0072] The present comparative example is a preparation method of an ultra-long weather-resistant anticorrosive pre-coating paint for steel, comprising the following steps:

[0073] Step S1: 2.5 g of 3-(2,3-epoxypropoxy)propyl trimethoxysilane, 10 g of dimethyl diethoxysilane and 80 mL of anhydrous toluene were added to a three-necked flask equipped with a stirrer, a thermometer and a gas inlet tube, protected by nitrogen, stirred at a temperature of 25°C and a stirring rate of 300 r / min for 30 min, then adjusted to pH 5 with a 12% hydrochloric acid solution, and then continued to stir at a temperature of 65°C for 6 h. After the reaction was completed, the reaction product was cooled to room temperature, then separated by standing, the organic phase was washed with distilled water for 5 times, then dried with anhydrous magnesium sulfate, then vacuum filtered, the filtrate was rotary evaporated to remove the solvent, and a silicone-modified epoxy resin was obtained;

[0074] Step S2: 5 g of mixed fillers, 60 mL of anhydrous ethanol and 30 mL of deionized water were added to a three-necked flask equipped with a stirrer and a thermometer, ultrasonically treated at an ultrasonic frequency of 40 kHz for 2 h, then 2.3 g of 3-glycidyloxypropyl triethoxysilane was added and stirred at a temperature of 25°C and a stirring rate of 300 r / min for 30 min, then continued to stir at a temperature of 75°C for 5 h. After the reaction was completed, the reaction product was cooled to room temperature, then centrifuged, then the precipitate was washed with distilled water for 5 times, then placed in a vacuum drying oven and dried at a temperature of 55°C for 6 h to obtain a modified mixed filler. The mixed filler was a mixture of glass powder, hexagonal boron nitride and nano-silica in a mass ratio of 35:15:10. The glass powder was Anmi micro-nano boron glass powder GT35. The hexagonal boron nitride was Dongchao Material DCB-10F micron hexagonal boron nitride. The nano-silica was nano-silica HL-200;

[0075] Step S3: The epoxy resin 17 parts, the silicone-modified epoxy resin 45 parts, the modified mixed filler 36 parts, the leveling agent 2 parts, the defoaming agent 2 parts, the curing agent 36 parts and the anhydrous ethanol 26 parts were weighed according to the weight parts, and were ready for use. The epoxy resin was epoxy resin E-51. The leveling agent was TEGO 100 water-based leveling agent. The defoaming agent was BYK 024 silicone defoaming agent. The curing agent was isophorone diamine;

[0076] Step S4: The epoxy resin, the silicone-modified epoxy resin, the modified mixed filler, the leveling agent, the defoaming agent, the curing agent and the anhydrous ethanol were added to a mixer, stirred and mixed at a temperature of 25°C and a stirring rate of 2000 r / min for 30 min, then stood for 15 min to obtain a super-long weather-resistant anticorrosive pre-coating paint for steel.

[0077] Performance test

[0078] The steel materials of Examples 1-3 and Comparative Examples 1-4 were sprayed with the super-long weather-resistant anticorrosive pre-coating paint, and the wet film thickness was 100 μm. The samples were dried at room temperature for 10 days to obtain test samples.

[0079] The test samples were immersed in distilled water at 40°C for 240 h, and the film phenomenon was observed to evaluate the water resistance. The test samples were immersed in a 10% by mass sulfuric acid solution for 24 h, and the film phenomenon was observed to evaluate the acid resistance. The test samples were immersed in a 5% by mass sodium hydroxide solution for 96 h, and the film phenomenon was observed to evaluate the alkali resistance. The test results are shown in the following table:

[0080]

[0081] According to the comparison between Examples 1-3 and Comparative Examples 1-4, it can be seen from the data in the above table that the super-long weather-resistant anticorrosive pre-coating paint for steel materials has excellent corrosion resistance.

[0082] In the description of the present specification, the description of the terms "one embodiment", "an example", "a specific example" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0083] The above is only an example and description of the present application, and those skilled in the art can make various modifications or supplements or use similar ways to replace the described specific embodiments, as long as they do not deviate from the invention or exceed the scope defined in the present application, which shall belong to the protection scope of the present application.

Claims

1. A pre-coated coating for steel with ultra-long weather resistance and corrosion protection, characterized in that, Includes the following components by weight: 15-17 parts epoxy resin, 35-45 parts silicone-modified epoxy resin, 28-36 parts modified mixed filler, 1.1-4.7 parts polyfluorine reinforcing agent, 1-2 parts leveling agent, 1-2 parts defoamer, 33-36 parts curing agent, and 20-26 parts anhydrous ethanol. The organosilicon-modified epoxy resin is prepared by the following steps: 3-(2,3-epoxypropoxy)propyltrimethoxysilane, dimethyldiethoxysilane and anhydrous toluene were stirred and reacted. The pH was then adjusted with hydrochloric acid solution and the reaction was continued. After the reaction was completed, the reaction product was cooled and allowed to stand to separate into layers. The organic phase was washed and dried, then vacuum filtered and the filtrate was evaporated by rotary evaporation to obtain organosilicon modified epoxy resin. The modified mixed filler is prepared by the following steps: The mixed filler, anhydrous ethanol, and deionized water were ultrasonically treated, followed by the addition of 3-glycidyl etheroxypropyltriethoxysilane and stirring. After the reaction was completed, the reaction product was cooled, centrifuged, and the precipitate was washed and dried to obtain the modified mixed filler. The mixed filler was a mixture of glass powder, hexagonal boron nitride, and nano-silica in a mass ratio of 20-35:5-15:3-10. The glass powder was Anmi Micro-Nano Boron Glass Powder GT35; the hexagonal boron nitride was Dongchao Materials DCB-10F micron-sized hexagonal boron nitride; and the nano-silica was nano-silica HL-200. The polyfluorinated reinforcing agent is prepared by the following steps: 3,5-bis(trifluorotoluene)benzaldehyde, propionic acid, and dimethyl sulfoxide were stirred and reacted. Then, pyrrole was added and the reaction was continued with stirring. After the reaction was completed, the reaction product was cooled and then filtered under vacuum. The filter cake was washed and dried to obtain the polyfluorinated reinforcing agent.

2. The ultra-long-lasting weather-resistant and anti-corrosion pre-coating for steel according to claim 1, characterized in that, The ratio of 3-(2,3-epoxypropoxy)propyltrimethoxysilane, dimethyldiethoxysilane, and anhydrous toluene is 0.5-2.5 g: 10 g: 70-80 mL; the mass fraction of the hydrochloric acid solution is 10-12%.

3. The ultra-long-lasting weather-resistant and anti-corrosion pre-coating for steel according to claim 1, characterized in that, The ratio of the mixed filler, anhydrous ethanol, deionized water, and 3-glycidyl etheroxypropyltriethoxysilane is 5g:50-60mL:20-30mL:0.7-2.3g.

4. The ultra-long-lasting weather-resistant and anti-corrosion pre-coating for steel according to claim 1, characterized in that, The ratio of 3,5-bis(trifluorotoluene)benzaldehyde, propionic acid, dimethyl sulfoxide, and pyrrole is 1.8-2.2 mL: 35-40 mL: 4-5 mL: 0.8-0.9 mL.

5. A method for preparing an ultra-long-lasting weather-resistant and anti-corrosion pre-coated coating for steel as described in any one of claims 1-4, characterized in that, Includes the following steps: Step 1: Weigh out 15-17 parts of epoxy resin, 35-45 parts of silicone-modified epoxy resin, 28-36 parts of modified mixed filler, 1.1-4.7 parts of polyfluorine reinforcing agent, 1-2 parts of leveling agent, 1-2 parts of defoamer, 33-36 parts of curing agent, and 20-26 parts of anhydrous ethanol according to the following weight proportions, and set aside for later use; Step 2: Add epoxy resin, silicone-modified epoxy resin, modified mixed filler, polyfluorine reinforcing agent, leveling agent, defoamer, curing agent, and anhydrous ethanol to a mixer. Mix for 20-30 minutes at a temperature of 20-25℃ and a stirring speed of 1000-2000 r / min. Then let it stand for 10-15 minutes to obtain an ultra-long weather-resistant and anti-corrosion pre-coating for steel.

6. The method for preparing an ultra-long-lasting weather-resistant and anti-corrosion pre-coating for steel according to claim 5, characterized in that, The epoxy resin is epoxy resin E-51; The leveling agent is TEGO 100 water-based leveling agent; The defoamer is BYK 024 silicone defoamer; The curing agent is isophorone diamine.

7. The application of the ultra-long weather-resistant and anti-corrosion pre-coating for steel prepared by the preparation method of the ultra-long weather-resistant and anti-corrosion pre-coating for steel as described in claim 6 in the corrosion protection of metal materials.

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