Waterborne epoxy anticorrosive paint and preparation method thereof

Abstract

The invention discloses a waterborne epoxy anticorrosive coating and a preparation method thereof, and belongs to the technical field of coating production. The waterborne epoxy anticorrosive paint is prepared from the following components in parts by weight: 38.5 to 42.0 parts of waterborne epoxy resin emulsion, 3.0 to 4.5 parts of modified preservative, 1.0 to 1.2 parts of dispersing agent, 0.5 to 1.2 parts of flatting agent, 0.5 to 1.0 part of thickening agent, 0.3 to 0.8 part of defoaming agent, 0.2 to 0.8 part of wetting agent, 5 to 12 parts of talcum powder, 4.5 to 10.0 parts of titanium dioxide, 5.5 to 10.0 parts of antirust pigment, 1.0 to 1.5 parts of cosolvent, 10.0 to 15.0 parts of deionized water, 50.0 to 55.0 parts of waterborne amine curing agent, 3.0 to 5.0 parts of flash rust inhibitor and 40.0 to 45.0 parts of deionized water. The self-made modified preservative is added, and through detection, the corrosion resistance of the finally prepared coating is remarkably improved on the basis that the coating has excellent comprehensive performance.

Description

Technical Field

[0001] The invention belongs to the technical field of coating production, and specifically relates to a water-based epoxy anticorrosive coating and a preparation method thereof. Background Art

[0002] Waterborne epoxy coating is a kind of epoxy coating that uses water as solvent or dispersion medium.

[0003] Waterborne epoxy coatings are generally composed of epoxy resins, curing agents, additives, pigments and fillers. Waterborne epoxy coatings have excellent environmental protection, safety and good adhesion, and are often used in industrial flooring, building decoration, chemical equipment and automotive parts coating.

[0004] Among them, chemical equipment and automobile parts coating require water-based epoxy coatings with excellent corrosion resistance. Specifically, in chemical production, if chemical equipment (such as tanks, etc.) that stores acidic raw materials does not have a good anti-corrosion coating, the acid can easily react chemically with the tank material, causing the tank to be corroded and perforated, causing raw materials to leak, and water-based epoxy coatings with high acid and alkali corrosion resistance can effectively isolate acid and alkali substances from the surface of the coated object, extending the service life of chemical equipment; at the same time, when water-based epoxy coatings are used for the coating of automotive parts (such as automobile chassis, wheels, etc.), the muddy water containing acid and alkali components splashed during the driving of the car, the chemical cleaners used during car maintenance, etc., all put forward higher requirements for the acid and alkali corrosion resistance of water-based epoxy coatings.

[0005] Therefore, it is necessary to develop waterborne epoxy coatings with excellent anti-corrosion properties. Summary of the invention

[0006] The present invention provides a waterborne epoxy anticorrosion coating and a preparation method thereof. The present invention improves the formula of the waterborne epoxy coating to ultimately achieve the purpose of improving the acid and alkali corrosion resistance of the waterborne epoxy coating.

[0007] The purpose of the present invention can be achieved through the following technical solutions:

[0008] A water-based epoxy anticorrosive coating, which is prepared by mixing component A and component B;

[0009] The component A comprises the following raw materials in parts by weight: 38.5 to 42.0 parts of waterborne epoxy resin emulsion, 3.0 to 4.5 parts of modified preservative, 1.0 to 1.2 parts of dispersant, 0.5 to 1.2 parts of leveling agent, 0.5 to 1.0 parts of thickener, 0.3 to 0.8 parts of defoamer, 0.2 to 0.8 parts of wetting agent, 5 to 12 parts of talc, 4.5 to 10.0 parts of titanium dioxide, 5.5 to 10.0 parts of anti-rust pigment, 1.0 to 1.5 parts of cosolvent and 10.0 to 15.0 parts of deionized water; the component B comprises the following raw materials in parts by weight: 50.0 to 55.0 parts of waterborne amine curing agent, 3.0 to 5.0 parts of anti-flash rust agent and 40.0 to 45.0 parts of deionized water.

[0010] Furthermore, the viscosity of the waterborne epoxy resin emulsion at 25° C. is 8000 to 19000 mPa·s, and the solid content is 52 to 55%.

[0011] Furthermore, the modified preservative is prepared by the following steps:

[0012] S1. Mix 2-carboxyphenyl phosphate and diethylenetriamine, evacuate, and then heat to 145-150° C., stir and react at constant temperature for 3-4 hours, and continue to evacuate during the reaction. After completion, heat to 225-230° C., stir and react at constant temperature for 5-6 hours, and continue to evacuate during the reaction. After completion, cool to room temperature, collect the product, wash the product three times with anhydrous ethanol, and then dry to constant weight at a constant temperature of 45-50° C. to obtain an intermediate. The intermediate is prepared by a cyclization reaction between the terminal carboxyl group of 2-carboxyphenyl phosphate and the amino group in diethylenetriamine. The preparation process of the intermediate is as follows: .

[0013] S2. Nitrogen is charged into anhydrous ethanol, and then the intermediate and 1-[6-(trifluoromethyl)-3-pyridine]ethanone are added thereto. After the addition is completed, the system is heated to produce reflux, and the reflux reaction is constantly heated for 5 to 6 hours. After completion, it is cooled to room temperature, and the anhydrous ethanol is removed by rotary evaporation. The product is collected to obtain a modified preservative. The modified preservative is prepared by the Schiff base reaction of the terminal amino group of the intermediate and the carbonyl group of 1-[6-(trifluoromethyl)-3-pyridine]ethanone. The preparation process of the modified preservative is as follows: .

[0014] Furthermore, the usage ratio of 2-carboxyphenyl phosphate and diethylenetriamine in S1 is 1 mol:1.0-1.2 mol.

[0015] Furthermore, the usage ratio of anhydrous ethanol, intermediate and 2-chloro-3-trifluoromethyl-5-acetylpyridine in S2 is 400mL:28.6-29.0g:0.1mol.

[0016] Furthermore, the particle size of the talcum powder is 800 mesh.

[0017] Furthermore, the co-solvent is prepared by mixing dipropylene glycol butyl ether, propylene glycol butyl ether and ethylene glycol monobutyl ether in a volume ratio of 2:1:1.

[0018] Furthermore, the viscosity of the water-based amine curing agent at 25° C. is 6300 to 14800 mpa·s.

[0019] Furthermore, a method for preparing a waterborne epoxy anticorrosive coating comprises the following steps:

[0020] Component A: Weigh the raw materials according to weight parts, add water-based epoxy resin emulsion, modified preservative, dispersant, leveling agent, thickener, defoamer and wetting agent into deionized water in sequence at a stirring speed of 500 r / min, stir for 20 to 30 minutes, then add talcum powder, titanium dioxide, anti-rust pigment and cosolvent, stir for 20 to 30 minutes to obtain component A;

[0021] Component B: Weigh the raw materials according to weight, add water-based amine curing agent and anti-flash rust agent to deionized water in sequence at a stirring speed of 500 r / min, and stir for 30 minutes to obtain component B;

[0022] Waterborne epoxy anticorrosion coating: Stir and mix component A and component B for 3 to 5 minutes to obtain a waterborne epoxy anticorrosion coating.

[0023] Furthermore, the waterborne epoxy anti-corrosion coating is prepared by mixing component A and component B in a mass ratio of 5:1.

[0024] Beneficial effects of the present invention:

[0025] The present invention provides a water-based epoxy anti-corrosion coating and a preparation method thereof. The present invention adds a self-made modified anti-corrosion agent of the present invention to the coating. After testing, the coating finally prepared has excellent comprehensive performance and its anti-corrosion performance is significantly improved.

[0026] Specifically, the modified preservative of the present invention is prepared by a Schiff base reaction of an intermediate having an amino terminal and 1-[6-(trifluoromethyl)-3-pyridine]ethanone having a carbonyl group, wherein the intermediate is prepared by a cyclization reaction of 2-carboxyphenyl phosphate having a carboxyl terminal and diethylenetriamine having an amino group, and finally, the modified preservative prepared by the present invention contains a pyridine ring, an amide bond, a phosphoric acid group and a fluorocarbon group.

[0027] Among them, the pyridine ring can improve the barrier performance. Specifically, the pyridine ring has a larger conjugated system and stronger polarity, which can increase the density of the coating formed by drying the paint, making it difficult for corrosive substances to penetrate the coating, thereby improving the barrier performance of the coating and achieving an improvement in the anti-corrosion performance of the coating.

[0028] Among them, amide bonds can strengthen hydrogen bonding. Specifically, hydrogen bonds can be formed between the carbonyl group and the amino group in the amide bond. This hydrogen bonding can increase the intermolecular force of the coating formed by the drying of the coating, improve the cohesion and stability of the coating, and make the coating more resistant to external factors, such as erosion by acidic and alkaline chemicals, thereby enhancing the anti-corrosion properties of the coating.

[0029] Among them, the phosphate group can form a dense phosphate protective film between the metal substrate and form a physical shielding layer on the metal surface, thereby improving the acid and alkali corrosion resistance of the coating formed by drying the paint and the metal substrate.

[0030] Among them, the fluorocarbon group can significantly improve the acid and alkali corrosion resistance of the coating formed by drying the paint. Specifically, the CF bond in the fluorocarbon group is very stable and not easily corroded by active molecules, so it has excellent corrosion resistance. Then, the fluorine atoms will gradually migrate to the surface of the coating during the process of drying the paint to form a coating, and then form an acid and alkali corrosion-resistant interface on the coating surface, ultimately achieving the purpose of improving the acid and alkali corrosion resistance of the coating. DETAILED DESCRIPTION

[0031] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0032] Example 1

[0033] Preparation of modified preservatives:

[0034] S1, stirring and adding 2-carboxyphenyl phosphate (97%; purchased from Shanghai Yuanye Biotechnology Co., Ltd.) and diethylenetriamine (97%; purchased from Shanghai Yuanye Biotechnology Co., Ltd.) into reactor A, wherein the amount ratio of 2-carboxyphenyl phosphate and diethylenetriamine is 1 mol:1.0 mol, after the addition is completed, the reactor A is evacuated, and then the temperature is raised to 145 ° C, and the reaction is stirred at a constant temperature for 3 hours, and vacuumization is continuously carried out during the reaction. After completion, the reactor A is heated to 225 ° C, and the reaction is stirred at a constant temperature for 5 hours, and vacuumization is continuously carried out during the reaction. After completion, it is cooled to room temperature, and the product is collected. The product is then washed three times with anhydrous ethanol, and then placed at 45 ° C. and dried to constant weight to obtain an intermediate;

[0035] S2. Add anhydrous ethanol to reactor B, then fill reactor B with nitrogen, and then add the intermediate and 1-[6-(trifluoromethyl)-3-pyridine]ethanone (97%; purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.) to reactor B, wherein the amount ratio of anhydrous ethanol, intermediate and 2-chloro-3-trifluoromethyl-5-acetylpyridine is 400mL:28.6g:0.1mol. After the addition is completed, reactor B is opened and heated to produce reflux, and the reflux reaction is kept heated for 5h. After completion, reactor B is cooled to room temperature, anhydrous ethanol is removed by rotary evaporation, and the product is collected to obtain a modified preservative.

[0036] Example 2

[0037] Preparation of modified preservatives:

[0038] S1, stirring and adding 2-carboxyphenyl phosphate (97%; purchased from Shanghai Yuanye Biotechnology Co., Ltd.) and diethylenetriamine (97%; purchased from Shanghai Yuanye Biotechnology Co., Ltd.) into reactor A, wherein the amount ratio of 2-carboxyphenyl phosphate and diethylenetriamine is 1 mol:1.2 mol, after the addition is completed, the reactor A is evacuated, and then the temperature is raised to 148 ° C, and the reaction is stirred at a constant temperature for 4 hours, and vacuumization is continuously carried out during the reaction. After completion, the reactor A is heated to 225 ° C, and the reaction is stirred at a constant temperature for 6 hours, and vacuumization is continuously carried out during the reaction. After completion, it is cooled to room temperature, and the product is collected. The product is then washed three times with anhydrous ethanol, and then placed at 45 ° C. and dried to constant weight to obtain an intermediate;

[0039] S2. Add anhydrous ethanol to reactor B, then fill reactor B with nitrogen, and then add the intermediate and 1-[6-(trifluoromethyl)-3-pyridine]ethanone (97%; purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.) to reactor B, wherein the amount ratio of anhydrous ethanol, intermediate and 2-chloro-3-trifluoromethyl-5-acetylpyridine is 400mL:28.8g:0.1mol. After the addition is completed, reactor B is opened and heated to produce reflux, and the reflux reaction is kept heated for 6h. After completion, reactor B is cooled to room temperature, anhydrous ethanol is removed by rotary evaporation, and the product is collected to obtain a modified preservative.

[0040] Example 3

[0041] Preparation of modified preservatives:

[0042] S1, stirring and adding 2-carboxyphenyl phosphate (97%; purchased from Shanghai Yuanye Biotechnology Co., Ltd.) and diethylenetriamine (97%; purchased from Shanghai Yuanye Biotechnology Co., Ltd.) into reactor A, wherein the amount ratio of 2-carboxyphenyl phosphate and diethylenetriamine is 1 mol:1.2 mol. After the addition is completed, reactor A is evacuated, and then the temperature is raised to 150° C., and the reaction is stirred at a constant temperature for 4 hours. During the reaction, vacuumization is continuously carried out. After completion, reactor A is heated to 230° C. and stirred at a constant temperature for 6 hours. During the reaction, vacuumization is continuously carried out. After completion, it is cooled to room temperature, and the product is collected. The product is then washed three times with anhydrous ethanol, and then placed at 50° C. and dried to constant weight to obtain an intermediate;

[0043] S2. Add anhydrous ethanol to reactor B, then fill reactor B with nitrogen, and then add the intermediate and 1-[6-(trifluoromethyl)-3-pyridine]ethanone (97%; purchased from Shanghai Aladdin Biochemical Technology Co., Ltd.) to reactor B, wherein the amount ratio of anhydrous ethanol, intermediate and 2-chloro-3-trifluoromethyl-5-acetylpyridine is 400mL:29.0g:0.1mol. After the addition is completed, reactor B is opened and heated to reflux, and the reflux reaction is kept at a constant temperature for 6h. After completion, reactor B is cooled to room temperature, anhydrous ethanol is removed by rotary evaporation, and the product is collected to obtain a modified preservative.

[0044] Example 4

[0045] A method for preparing a waterborne epoxy anticorrosive coating:

[0046] First, a waterborne epoxy anticorrosive coating is prepared by mixing component A and component B in a mass ratio of 5:1, wherein component A comprises the following raw materials in parts by mass: 38.5 parts of waterborne epoxy resin emulsion, 3.0 parts of modified preservative prepared in Example 1, 1.0 parts of dispersant, 0.5 parts of leveling agent, 0.5 parts of thickener, 0.3 parts of defoamer, 0.2 parts of wetting agent, 5 parts of talcum powder, 4.5 parts of titanium dioxide, 5.5 parts of rust-proof pigment, 1.0 parts of cosolvent and 10.0 parts of deionized water; wherein component B comprises the following raw materials in parts by mass: 50.0 parts of waterborne amine curing agent, 3.0 parts of anti-flash rust agent and 40.0 parts of deionized water;

[0047] Among them, water-based epoxy resin emulsion (Epikote5522-WY-55A; 25°C viscosity 8000-19000 mPa·s; epoxy equivalent 550-700 g / ep; solid content 52-55%) was purchased from Hanson Chemical Company, USA;

[0048] Among them, the dispersant (BYK-2152) was purchased from BYK;

[0049] Among them, the leveling agent (BYK-306) was purchased from BYK;

[0050] Among them, the thickener (SN-612NC) was purchased from San Nopco, Japan;

[0051] Among them, the defoamer (BYK-A535) was purchased from BYK;

[0052] Among them, the wetting agent (BYK-104S) was purchased from BYK;

[0053] Among them, talc powder (800 mesh) was purchased from Omiya Company;

[0054] Among them, titanium dioxide (HR-969) was purchased from Omya Company;

[0055] Among them, the anti-rust pigment (SZP-391 environmentally friendly type) was purchased from Halox Company, USA;

[0056] The cosolvent is a mixture of dipropylene glycol butyl ether, propylene glycol butyl ether and ethylene glycol monobutyl ether in a volume ratio of 2:1:1, all of which are industrial pure grades and purchased from Dow Chemical Pacific Co., Ltd.;

[0057] Among them, deionized water was homemade;

[0058] Among them, the water-based amine curing agent (Epikote8535-W-50; 25°C viscosity 6300-14800 mPa·s; amine value 373-453; equivalent weight 204) was purchased from Hanson Chemical Company, USA;

[0059] Among them, the flash rust inhibitor (Halox350) was purchased from Halox Company, USA;

[0060] Then, the preparation method of the water-based epoxy anticorrosive coating comprises the following steps:

[0061] Component A: Weigh the raw materials according to weight parts, add the aqueous epoxy resin emulsion, the modified preservative prepared in Example 1, the dispersant, the leveling agent, the thickener, the defoamer and the wetting agent into deionized water in sequence at a stirring speed of 500 r / min, stir for 20 minutes, then add talcum powder, titanium dioxide, anti-rust pigment and cosolvent thereto, stir for 20 minutes, and obtain component A;

[0062] Component B: Weigh the raw materials according to weight, add water-based amine curing agent and anti-flash rust agent to deionized water in sequence at a stirring speed of 500 r / min, and stir for 30 minutes to obtain component B;

[0063] Waterborne epoxy anticorrosion coating: Component A and component B were mixed at a mass ratio of 5:1 for 3 minutes to obtain a waterborne epoxy anticorrosion coating.

[0064] Example 5

[0065] A method for preparing a waterborne epoxy anticorrosive coating:

[0066] First, a waterborne epoxy anticorrosive coating is prepared by mixing component A and component B in a mass ratio of 5:1, wherein component A comprises the following raw materials in parts by mass: 40.0 parts of waterborne epoxy resin emulsion, 4.0 parts of modified anticorrosive prepared in Example 2, 1.0 parts of dispersant, 1.0 parts of leveling agent, 0.6 parts of thickener, 0.5 parts of defoamer, 0.4 parts of wetting agent, 7 parts of talcum powder, 6.5 parts of titanium dioxide, 6.0 parts of rust-proof pigment, 1.0 parts of cosolvent and 12.0 parts of deionized water; wherein component B comprises the following raw materials in parts by mass: 52.0 parts of waterborne amine curing agent, 5.0 parts of anti-flash rust agent and 45.0 parts of deionized water;

[0067] Among them, water-based epoxy resin emulsion (Epikote5522-WY-55A; 25°C viscosity 8000-19000 mPa·s; epoxy equivalent 550-700 g / ep; solid content 52-55%) was purchased from Hanson Chemical Company, USA;

[0068] Among them, the dispersant (BYK-2152) was purchased from BYK;

[0069] Among them, the leveling agent (BYK-306) was purchased from BYK;

[0070] Among them, the thickener (SN-612NC) was purchased from San Nopco, Japan;

[0071] Among them, the defoamer (BYK-A535) was purchased from BYK;

[0072] Among them, the wetting agent (BYK-104S) was purchased from BYK;

[0073] Among them, talc powder (800 mesh) was purchased from Omiya Company;

[0074] Among them, titanium dioxide (HR-969) was purchased from Omya Company;

[0075] Among them, the anti-rust pigment (SZP-391 environmentally friendly type) was purchased from Halox Company, USA;

[0076] The cosolvent is a mixture of dipropylene glycol butyl ether, propylene glycol butyl ether and ethylene glycol monobutyl ether in a volume ratio of 2:1:1, all of which are industrial pure grades and purchased from Dow Chemical Pacific Co., Ltd.;

[0077] Among them, deionized water was homemade;

[0078] Among them, the water-based amine curing agent (Epikote8535-W-50; 25°C viscosity 6300-14800 mPa·s; amine value 373-453; equivalent weight 204) was purchased from Hanson Chemical Company, USA;

[0079] Among them, the flash rust inhibitor (Halox350) was purchased from Halox Company, USA;

[0080] Then, the preparation method of the water-based epoxy anticorrosive coating comprises the following steps:

[0081] Component A: Weigh the raw materials according to weight parts, add the aqueous epoxy resin emulsion, the modified preservative prepared in Example 2, the dispersant, the leveling agent, the thickener, the defoamer and the wetting agent into deionized water in sequence at a stirring speed of 500 r / min, stir for 30 minutes, then add talcum powder, titanium dioxide, antirust pigment and cosolvent thereto, stir for 30 minutes, and obtain component A;

[0082] Component B: Weigh the raw materials according to weight, add water-based amine curing agent and anti-flash rust agent to deionized water in sequence at a stirring speed of 500 r / min, and stir for 30 minutes to obtain component B;

[0083] Waterborne epoxy anticorrosion coating: Component A and component B were mixed at a mass ratio of 5:1 for 5 minutes to obtain a waterborne epoxy anticorrosion coating.

[0084] Example 6

[0085] A method for preparing a waterborne epoxy anticorrosive coating:

[0086] First, a waterborne epoxy anticorrosive coating is prepared by mixing component A and component B in a mass ratio of 5:1, wherein component A comprises the following raw materials in parts by mass: 42.0 parts of waterborne epoxy resin emulsion, 4.5 parts of modified preservative prepared in Example 3, 1.2 parts of dispersant, 1.2 parts of leveling agent, 1.0 parts of thickener, 0.8 parts of defoamer, 0.8 parts of wetting agent, 12 parts of talcum powder, 10.0 parts of titanium dioxide, 10.0 parts of rust-proof pigment, 1.5 parts of cosolvent and 15.0 parts of deionized water; wherein component B comprises the following raw materials in parts by mass: 55.0 parts of waterborne amine curing agent, 5.0 parts of anti-flash rust agent and 45.0 parts of deionized water;

[0087] Among them, water-based epoxy resin emulsion (Epikote5522-WY-55A; 25°C viscosity 8000-19000 mPa·s; epoxy equivalent 550-700 g / ep; solid content 52-55%) was purchased from Hanson Chemical Company, USA;

[0088] Among them, the dispersant (BYK-2152) was purchased from BYK;

[0089] Among them, the leveling agent (BYK-306) was purchased from BYK;

[0090] Among them, the thickener (SN-612NC) was purchased from San Nopco, Japan;

[0091] Among them, the defoamer (BYK-A535) was purchased from BYK;

[0092] Among them, the wetting agent (BYK-104S) was purchased from BYK;

[0093] Among them, talc powder (800 mesh) was purchased from Omiya Company;

[0094] Among them, titanium dioxide (HR-969) was purchased from Omya Company;

[0095] Among them, the anti-rust pigment (SZP-391 environmentally friendly type) was purchased from Halox Company, USA;

[0096] The cosolvent is a mixture of dipropylene glycol butyl ether, propylene glycol butyl ether and ethylene glycol monobutyl ether in a volume ratio of 2:1:1, all of which are industrial pure grades and purchased from Dow Chemical Pacific Co., Ltd.;

[0097] Among them, deionized water was homemade;

[0098] Among them, the water-based amine curing agent (Epikote8535-W-50; 25°C viscosity 6300-14800 mPa·s; amine value 373-453; equivalent weight 204) was purchased from Hanson Chemical Company, USA;

[0099] Among them, the flash rust inhibitor (Halox350) was purchased from Halox Company, USA;

[0100] Then, the preparation method of the water-based epoxy anticorrosive coating comprises the following steps:

[0101] Component A: Weigh the raw materials according to their weight parts, add the aqueous epoxy resin emulsion, the modified preservative prepared in Example 3, the dispersant, the leveling agent, the thickener, the defoamer and the wetting agent into deionized water in sequence at a stirring speed of 500 r / min, stir for 30 minutes, then add talcum powder, titanium dioxide, anti-rust pigment and cosolvent thereto, stir for 30 minutes, and obtain component A;

[0102] Component B: Weigh the raw materials according to weight, add water-based amine curing agent and anti-flash rust agent to deionized water in sequence at a stirring speed of 500 r / min, and stir for 30 minutes to obtain component B;

[0103] Waterborne epoxy anticorrosion coating: Component A and component B were mixed at a mass ratio of 5:1 for 5 minutes to obtain a waterborne epoxy anticorrosion coating.

[0104] Comparative Example 1

[0105] Comparative Example 1 is the control group of Example 5, in which 4.0 parts of the modified preservative prepared by Raw Material Example 2 in Component A of Example 5 are removed, and the remaining raw materials, raw material amounts, and preparation methods remain unchanged, and finally a water-based epoxy anticorrosive coating is obtained.

[0106] Test Example 1

[0107] The performance test of the waterborne epoxy anticorrosive coating prepared in Examples 4 to 6 and Comparative Example 1 was carried out. The performance test process is as follows, and the test results are shown in Table 1:

[0108] The drying time is carried out in accordance with GB / T 1728-2020 "Determination of drying time of paint film and putty film":

[0109] Adhesion test is carried out according to GB / T 5210-2006 "Pull-off adhesion test for paints and varnishes":

[0110] The cross-cut test shall be carried out in accordance with GB / T 9286-1998 "Cross-cut test for paint and varnish coatings";

[0111] Pencil hardness is in accordance with GB / T 6739-2006 “Determination of film hardness of paints and varnishes by pencil method”;

[0112] Flexibility shall be in accordance with GB / T 1731-2020 "Determination of flexibility of paint film and putty film";

[0113] The impact strength test is carried out in accordance with GB / T 1732-2020 "Determination of impact resistance of paint films";

[0114] The acid resistance test and alkali resistance test shall be carried out in accordance with GB / T 9274-1988 "Determination of resistance of paints and varnishes to liquid media".

[0115] Table 1 Test results project Example 4 Example 5 Example 6 Comparative Example 1 Drying time (surface drying) / min 60 50 50 50 Drying time (actual drying) / h 8 7 7 7 Adhesion (pull-off method) / MPa 8.2 8.6 8.5 7.5 Adhesion (cross-cut method) / grade 0 0 0 1 Pencil hardness (scratch) 4H 4H 4H 4H Flexibility (bending test) / mm 1 1 1 1 Impact strength / cm 50 50 50 50 <![CDATA[Acid resistance (50 g / L; H2SO4)]]> Blistering and shedding occurred at 216h Blistering and shedding occurred after 240 hours Blistering and shedding occurred after 240 hours Blistering and shedding occurred after 48 hours Alkali resistance (50g / L; NaOH) Blistering and shedding occurred at 216h Blistering and shedding occurred after 240 hours Blistering and shedding occurred after 240 hours Blistering and shedding occurred after 48 hours

[0116] It can be seen from Table 1 that the waterborne epoxy anti-corrosion coatings prepared in Examples 4 to 6 have excellent comprehensive performance. By comparing the data of Example 5 and Comparative Example 1, it can be seen that the acid and alkali resistance of the waterborne epoxy anti-corrosion coating prepared in Example 5 is significantly improved.

[0117] It should be noted that, in this article, terms such as "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or equipment that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment.

[0118] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A water-based epoxy anticorrosive coating, characterized in that: It is made by mixing component A and component B; The component A comprises the following raw materials in parts by weight: 38.5 to 42.0 parts of waterborne epoxy resin emulsion, 3.0 to 4.5 parts of modified preservative, 1.0 to 1.2 parts of dispersant, 0.5 to 1.2 parts of leveling agent, 0.5 to 1.0 parts of thickener, 0.3 to 0.8 parts of defoamer, 0.2 to 0.8 parts of wetting agent, 5 to 12 parts of talc, 4.5 to 10.0 parts of titanium dioxide, 5.5 to 10.0 parts of anti-rust pigment, 1.0 to 1.5 parts of cosolvent and 10.0 to 15.0 parts of deionized water; the component B comprises the following raw materials in parts by weight: 50.0 to 55.0 parts of waterborne amine curing agent, 3.0 to 5.0 parts of anti-flash rust agent and 40.0 to 45.0 parts of deionized water.

2. A waterborne epoxy anticorrosive coating according to claim 1, characterized in that: The viscosity of the waterborne epoxy resin emulsion at 25° C. is 8000-19000 mpa·s, and the solid content is 52-55%.

3. A waterborne epoxy anticorrosive coating according to claim 1, characterized in that: The modified preservative is prepared by the following steps: S1. Mix 2-carboxyphenyl phosphate and diethylenetriamine, evacuate, and then heat to 145-150° C., stir and react at constant temperature for 3-4 hours, and continue to evacuate during the reaction. After completion, heat to 225-230° C., stir and react at constant temperature for 5-6 hours, and continue to evacuate during the reaction. After completion, cool to room temperature, collect the product, wash the product three times with anhydrous ethanol, and then dry it at a constant temperature of 45-50° C. to constant weight to obtain an intermediate; S2. Fill anhydrous ethanol with nitrogen, and then add the intermediate and 1-[6-(trifluoromethyl)-3-pyridine]ethanone. After the addition is completed, the system is heated to reflux, and the reflux reaction is kept constant for 5 to 6 hours. After completion, it is cooled to room temperature, the anhydrous ethanol is removed by rotary evaporation, and the product is collected to obtain a modified preservative.

4. A waterborne epoxy anticorrosive coating according to claim 3, characterized in that: The usage ratio of 2-carboxyphenyl phosphate and diethylenetriamine in S1 is 1 mol:1.0-1.2 mol.

5. A waterborne epoxy anticorrosive coating according to claim 3, characterized in that: The usage ratio of anhydrous ethanol, intermediate and 2-chloro-3-trifluoromethyl-5-acetylpyridine in S2 is 400mL:28.6-29.0g:0.1mol.

6. A waterborne epoxy anticorrosive coating according to claim 1, characterized in that: The particle size of the talcum powder is 800 meshes.

7. The waterborne epoxy anticorrosive coating according to claim 1, characterized in that: The cosolvent is prepared by mixing dipropylene glycol butyl ether, propylene glycol butyl ether and ethylene glycol monobutyl ether in a volume ratio of 2:1:

1.

8. The waterborne epoxy anticorrosive coating according to claim 1, characterized in that: The viscosity of the water-based amine curing agent at 25° C. is 6300 to 14800 mpa·s.

9. A method for preparing a waterborne epoxy anticorrosive coating according to any one of claims 1 to 8, characterized in that: The following steps are involved: Component A: Weigh the raw materials according to weight parts, add water-based epoxy resin emulsion, modified preservative, dispersant, leveling agent, thickener, defoamer and wetting agent into deionized water in sequence at a stirring speed of 500 r / min, stir for 20 to 30 minutes, then add talcum powder, titanium dioxide, anti-rust pigment and cosolvent, stir for 20 to 30 minutes to obtain component A; Component B: Weigh the raw materials according to weight, add water-based amine curing agent and anti-flash rust agent to deionized water in sequence at a stirring speed of 500 r / min, and stir for 30 minutes to obtain component B; Waterborne epoxy anticorrosion coating: Stir and mix component A and component B for 3 to 5 minutes to obtain a waterborne epoxy anticorrosion coating.

10. The method for preparing a waterborne epoxy anticorrosive coating according to claim 9, characterized in that: The waterborne epoxy anticorrosive coating is prepared by mixing component A and component B in a mass ratio of 5:1.