High adhesion corrosion resistant epoxy coating and method of making and using same

Abstract

The application discloses a high-adhesion anticorrosive epoxy coating and a preparation method and use method thereof. The high-adhesion anticorrosive epoxy coating comprises the following components in parts by weight: component A 50-80 parts, component B 10 parts; the component A comprises the following components in parts by weight: first resin base material 16-28 parts, second resin base material 3-7 parts, modified filler 50-70 parts, dispersing agent 0.5-0.9 parts, defoaming agent 0.5-0.9 parts, adhesion promoter 0.5-0.9 parts, solvent 5-9 parts; and the component B comprises the following components in parts by weight: curing agent monomer 60-70 parts, low surface tolerance agent 4-6 parts, plasticizing cosolvent 20-30 parts, curing accelerator 4-8 parts. The high-adhesion anticorrosive epoxy coating has good anticorrosive performance and large adhesion, thereby ensuring long-term safe service of steel structure and facilities in a splashing area.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of paint, in particular to a high adhesion anticorrosive epoxy paint and a preparation method and use method thereof. BACKGROUND

[0002] The splash zone of the ocean is the most serious area of corrosion of steel structure facilities. Generally, the average corrosion rate of steel in the marine atmosphere is about 0.03-0.08 mm / a, and the splash zone of the ocean is 0.3-0.5 mm / a. The corrosion protection measures for the splash zone of the ocean steel structure mainly include: ① the method of increasing the corrosion allowance, which has many disadvantages such as waste of steel, local pitting corrosion, safety hazards, etc., and has gradually been abandoned; ② low alloy steel resistant to seawater corrosion, which has good corrosion resistance than general carbon steel, but still needs to take appropriate protective measures, and is only suitable for new structures; ③ inorganic and organic coating protection, which is an economic and effective method, but the coating protection requires high surface treatment, and the commonly used coating is difficult to meet the long-term impact resistance requirement, and the coating is easy to bubble and peel under the impact of seawater, thereby causing serious local corrosion, and it is difficult to achieve the coating requirements for the surface treatment of the steel structure in service; ④ metal spraying has good corrosion protection effect, but the on-site construction is difficult, especially for the construction of complex structures, which also needs to be used in combination with other protective measures; ⑤ the method of covering Monel alloy, titanium alloy and seawater-resistant stainless steel sheath, which has good corrosion resistance, but the material is expensive, so its comprehensive application is still limited.

[0003] Therefore, in view of the harsh corrosion environment of the splash zone steel facility coating, the coating is often impacted by waves, and with the rise and fall of the tide, the maintenance coating may be immersed in seawater or impacted by waves before it is solidified, plus mechanical damage and other problems, it is urgent to develop a corrosion-resistant coating with good corrosion resistance and adhesion. SUMMARY

[0004] The present application provides a high adhesion anticorrosive epoxy paint and a preparation method and use method thereof to solve the above technical problems.

[0005] In the first aspect, the present application provides a high adhesion anticorrosive epoxy paint, which is realized by the following technical scheme.

[0006] A high adhesion anticorrosive epoxy paint, comprising the following components by weight: component A 50-80 parts, component B 10 parts;

[0007] The component A comprises the following components by weight: first resin base material 16-28 parts, second resin base material 3-7 parts, modified filler 50-70 parts, dispersing agent 0.5-0.9 parts, defoaming agent 0.5-0.9 parts, adhesion promoter 0.5-0.9 parts, and solvent 5-9 parts.

[0008] The component B includes the following components by weight: 60-70 parts of curing agent monomer, 4-6 parts of low surface tolerance agent, 20-30 parts of plasticization cosolvent, 4-8 parts of curing accelerator.

[0009] Further, the first resin base is an epoxy resin with an epoxy value not less than 0.40.

[0010] By adopting the technical scheme, the first resin base is a mixture of a small molecular weight epoxy resin and one or several modified resins. The composition of the resin has a significant influence on the low surface permeability and viscosity reduction effect of the high solid content epoxy coating for maintenance. The surface energy of St2 / St3 surface and wet surface is low. In order to make the coating penetrate the low surface layer during the flowing and curing process, combine with the base material more deeply, greatly improve the adhesion, and improve the corrosion resistance, the base resin should be able to easily penetrate the base material, better wet the wet and low surface base material, and provide excellent adhesion. These characteristics require the resin to be flexible and have low crosslinking density. The epoxy resin can be modified to reduce the surface tension of the coating and increase the adaptability to the low surface. A long carbon chain is introduced into the small molecular epoxy resin to reduce the polarity and surface tension of the modified epoxy resin and improve the hydrophobicity. Special small molecule modified resin is used to reduce the viscosity and surface tension of the resin system, thereby improving the permeability, the ability of the coating to penetrate the low surface layer, the adhesion of the coating, and the corrosion resistance.

[0011] Further, the second resin base is selected from any one or several of unsaturated polyester resin, alkyl glycidyl ether, cashew shell oil phenol aldehyde resin polyol, and cashew phenol glycidyl ether.

[0012] By adopting the technical scheme, the second resin base has the following special effects in the high-adhesion anticorrosion epoxy coating for maintenance: (1) the modified resin contains a long carbon chain and has much lower polarity than the small molecule epoxy resin, so that the resin system's polarity and the coating's surface tension can be reduced after use, which is beneficial to wetting and spreading on the surface of a low surface treatment substrate with low surface energy, and the introduction of the non-polar long carbon chain can improve the hydrophobicity of the coating, and improve the water resistance and corrosion resistance of the coating; (2) the modified resin has small viscosity, which helps to reduce the viscosity of the coating, improve the permeability of the coating, increase the solid content and reduce VOC; (3) the modified resin can adjust the crosslinking density of the coating system and endow the coating with special properties according to the special functional groups contained; the non-active long carbon chain modified resin does not participate in the reaction of epoxy and amine, so that the crosslinking density of the system can be reduced and the flexibility of the coating can be further improved; the single functionality active modified resin will react with amine radicals to reduce the concentration of free radicals in the mixed coating, play a role in polymerization inhibition, reduce the curing speed of the coating and prolong the service life of the high solid content coating; the multi-functionality active modified resin can increase the crosslinking density, increase the hardness and wear resistance of the coating.

[0013] Further, the modified filler is obtained by mixing and reacting aniline, hydroxylated boron nitride powder and 3-aminopropyl triethoxysilane.

[0014] Still further, the preparation method of the modified filler comprises the following steps:

[0015] a. 3-aminopropyl triethoxysilane with a mass of 0.08-0.12 times that of the hydroxylated boron nitride powder is added to an ethanol solution with a mass of 0.24-0.36 times that of the hydroxylated boron nitride powder, and after stirring, the hydroxylated boron nitride powder is added, and stirred in a water bath at 58-62℃ for 1.8-2.2h, and after the reaction is completed, the product is washed, dried, ground and sieved to obtain a pre-modified boron nitride powder;

[0016] b. 10 parts by weight of the pre-modified boron nitride powder prepared in step a is added to 70-80 parts by weight of a hydrochloric acid solution, and after dispersion, a pre-modified boron nitride powder dispersion solution is obtained;

[0017] 9-11 parts by weight of aniline is added to 36-44 parts by weight of a hydrochloric acid solution, and after dissolution, an aniline solution is obtained;

[0018] 1.1-1.3 parts by weight of ammonium persulfate, 1.4-1.8 parts by weight of potassium dichromate and 10-12.4 parts by weight of a hydrochloric acid solution are mixed to obtain a catalyst solution;

[0019] The aniline solution is added to the pre-modified boron nitride powder dispersion solution, and after stirring, the catalyst solution is added dropwise within 25-35min to initiate polymerization, and the reaction is continued for 23-25h, and after the reaction is completed, the product is washed, dried, ground and sieved to obtain a modified filler.

[0020] Further, in step a, the ethanol solution is a 95% ethanol aqueous solution.

[0021] Further, in step a, after the 3-aminopropyl triethoxysilane is added to the ethanol solution, the magnetic stirring is performed for 28-32 min.

[0022] Further, in step b, the concentration of the hydrochloric acid solution is 10%.

[0023] Further, in step b, after the pre-modified boron nitride powder is added to the hydrochloric acid solution, the ultrasonic dispersion is performed for 2.5-3.5 h.

[0024] Further, in step b, the aniline solution is added to the pre-modified boron nitride powder dispersion, and the magnetic stirring is performed for 50-70 min.

[0025] Further, the method for preparing the hydroxylated boron nitride powder comprises the following steps:

[0026] The boron nitride powder is heated to 900-1100℃ at a heating rate of 8-12℃ / min, and is kept at the temperature for 1.5-2.5 h. After natural cooling, the boron nitride powder is ultrasonically dispersed in water in an amount of 6-8 times the mass of the boron nitride powder for 4-6 h. The supernatant is obtained by centrifugation, and is dried and ground to obtain the hydroxylated boron nitride powder.

[0027] More specifically, the method for preparing the hydroxylated boron nitride powder comprises the following steps: the boron nitride powder is placed in a ceramic crucible, and is placed in the center of a tube furnace. A crucible filled with deionized water is placed on one side of the tube furnace. The tube furnace is set to a heating rate of 8-12℃ / min, and is heated to 900-1100℃ and kept at the temperature for 1.5-2.5 h. Then, the temperature is naturally cooled to room temperature, and the boron nitride powder is ultrasonically dispersed in deionized water in an amount of 6-8 times the mass of the boron nitride powder for 4-6 h. The supernatant is obtained by centrifugation at a speed of 8000 r / min, and is vacuum dried at 60℃. After complete drying, the supernatant is ground in an agate mortar and sieved to obtain the hydroxylated boron nitride powder.

[0028] Further, the solvent is selected from any one or several of methyl ethyl ketone, dimethylbenzene, butanol, and methyl isobutyl ketone.

[0029] By using the above technical solution, in the early stage of coating construction, the solvent can reduce the viscosity of the coating system, improve the low surface permeability of the coating, and improve the workability of the coating. The addition of the ketone solvent can improve the compatibility of the epoxy resin and the modified resin. Meanwhile, the ketone carbonyl group can reduce the reaction speed of the epoxy functional group and the active amine, and prolong the service life of the high solid content coating. With the volatilization of the solvent, the viscosity of the system increases, the post-curing speed of the coating increases, and the rapid drainage performance is significantly improved.

[0030] Further, the curing agent monomer is 3,3'-diamino-2,2'-bipyridine.

[0031] Further, the preparation method of the 3,3'-diamino-2,2'-bipyridine comprises the following steps:

[0032] 50-80 parts by weight of stannous chloride, 200-300 parts by weight of concentrated hydrochloric acid, 10 parts by weight of 3,3'-dinitro-2,2'-bipyridine are mixed and reacted at 90-100 DEG C for 1-2 hours, the pH is adjusted to 8-9, and after extraction with dichloromethane, the residue is recrystallized in water to obtain 3,3'-diamino-2,2'-bipyridine.

[0033] Further, the pH is neutralized to 8-9 using sodium hydroxide.

[0034] Further, the low surface tolerance agent is selected from any one or several of N-aminopropyl morpholine, KH-550, KH-792, Hymenstecen 1121, and Akzonobel Duomeen TDO.

[0035] By using the above technical solution, the low surface tolerance agent can further improve the adhesion of the coating to the wet surface, the rusted surface, and the St2 / St3 surface. The addition of the low surface tolerance agent can accelerate the migration of water molecules on the wet surface and reduce the reactivity of water molecules and iron. The low surface tolerance agent also has the effect of complexing with a small amount of rust or polycondensing with the hydroxyl groups on the surface of the substrate to form a stable and firm compound, further improving the adhesion to the rusted and St2 / St3 surfaces, improving the adhesion of the maintenance coating, and improving the low surface treatment tolerance.

[0036] Further, the plasticizing cosolvent is benzyl alcohol.

[0037] By using the above technical solution, benzyl alcohol can reduce the viscosity of the coating system, improve the low surface penetration efficiency, adjust the polarity of the B component, improve the compatibility of the resin-curing agent system, and further improve the problem of excessive cross-linking density and brittle film of the curing agent monomer 3,3'-diamino-2,2'-bipyridine and the curing accelerator after use.

[0038] Further, the curing accelerator is selected from any one or several of phenol, salicylic acid, and tris-(dimethylaminomethyl) phenol.

[0039] By using the above technical solution, the B component curing agent not only further improves the hydrophobicity of the coating resin-curing agent after curing with the A component, prevents the migration of water molecules to the surface of the substrate during the post-curing process under water, and has the effect of "water molecules cannot enter", but also endows the coating with excellent physical and mechanical properties, moisture environment and low surface tolerance performance, fast curing performance, fast water-continuing-curing performance, and long-term corrosion protection performance.

[0040] Further, the dispersant is selected from any one or several of BYK-110, BYK-ATU, BYK-2009, and BYK-2155.

[0041] Further, the defoaming agent is selected from any one or several of BYK-066, EFKA-2722, DEHEN 6800, and BYK-A530.

[0042] Further, the adhesion promoter is selected from KH-560.

[0043] In a second aspect, the present application provides a preparation method of the high-adhesion anticorrosive epoxy coating, which is achieved by the following technical scheme.

[0044] The preparation method of the high-adhesion anticorrosive epoxy coating comprises the following steps.

[0045] S1. mixing a prescribed amount of a first resin base material, a second resin base material, a modified filler, a dispersant, a defoaming agent, an adhesion promoter, and a solvent uniformly to obtain component A;

[0046] S2. mixing a prescribed amount of a curing agent monomer, a low-surface-tolerance agent, a plasticizing cosolvent, and a curing promoter to obtain component B;

[0047] S3. packaging the prescribed amount of component A and component B separately for standby to obtain the high-adhesion anticorrosive epoxy coating.

[0048] In a third aspect, the present application provides a use method of the high-adhesion anticorrosive epoxy coating, which is achieved by the following technical scheme.

[0049] The use method of the high-adhesion anticorrosive epoxy coating comprises the following steps: mixing a prescribed amount of component A and component B uniformly, and then spraying the high-adhesion anticorrosive epoxy coating with a thickness of 300-1000 μm on a steel facility in a splashing area, and curing at 60-80 ℃ for 15-30 h.

[0050] The present application has the following beneficial effects.

[0051] Firstly, the introduction of boron nitride nanosheets in the paint can produce a water barrier effect, that is, a "labyrinth effect", which blocks the diffusion of corrosive media to the metal substrate, thereby protecting the metal from corrosion. The hydroxylated boron nitride powder is first pre-modified with 3-aminopropyl triethoxysilane, and then the in-situ polymerization method is used to polymerize aniline to form polyaniline and graft it in the pre-modified boron nitride powder. This improves the dispersibility of the boron nitride powder and introduces conductive polymer polyaniline molecular chains into the paint. Polyaniline can act as an anode and undergoes an oxidation-reduction reaction, causing the metal substrate to be passivated as a cathode. A passivation film formed by metal oxides is generated, preventing the corrosion of corrosive media on the metal substrate, and further enhancing the corrosion resistance of the high-adhesion corrosion-resistant epoxy coating for maintenance.

[0052] Secondly, 3,3'-diamino-2,2'-dipyridyl is used as a curing agent monomer in component B. On the one hand, when in use, 3,3'-diamino-2,2'-dipyridyl complexes with free metal ions on the surface of the splash zone steel facility to obtain 3,3'-diamino-2,2'-dipyridyl iron complex, which stably adheres the high-adhesion corrosion-resistant epoxy coating for maintenance to the surface of the splash zone steel facility. On the other hand, under the action of 3,3'-diamino-2,2'-dipyridyl iron complex, 3,3'-diamino-2,2'-dipyridyl is grafted with aniline in component A to increase the crosslinking density of the high-adhesion corrosion-resistant epoxy coating for maintenance, thereby enhancing the hardness and wear resistance of the coating. DETAILED DESCRIPTION

[0053] The present patent application is further illustrated below in conjunction with the examples.

[0054] The experimental methods used in the following examples are conventional methods unless otherwise specified. The materials, reagents, etc. used in the following preparation examples and examples can be obtained from commercial channels unless otherwise specified.

[0055] Example 1

[0056] A preparation method of a high-adhesion corrosion-resistant epoxy coating, comprising the following steps:

[0057] (1) 16 g of a first resin base material, 3 g of a second resin base material, 50 g of a modified filler, 0.5 g of a dispersing agent, 0.5 g of a defoaming agent, 0.5 g of an adhesion promoter, and 5 g of a solvent are mixed uniformly to obtain component A;

[0058] (2) 60 g of a curing agent monomer 3,3'-diamino-2,2'-dipyridyl, 4 g of a low surface tolerance agent, 20 g of a plasticizing cosolvent, and 4 g of a curing promoter are obtained to obtain component B;

[0059] (3) 50 g of component A and 10 g of component B are packaged separately for standby use to obtain a high-adhesion corrosion-resistant epoxy coating for maintenance.

[0060] The first resin base is E-44 epoxy resin with an epoxy value not less than 0.40;

[0061] The second resin base is Novares LA700 liquid petroleum resin from Germany;

[0062] The preparation steps of the modified filler include:

[0063] S1. Put the boron nitride powder in a ceramic crucible, place it in the center of the tube furnace, and place a crucible filled with deionized water on one side of the tube furnace. Set the tube furnace to an 8℃ / min heating rate, heat to 900℃ for 1.5h, then naturally cool to room temperature, then ultrasonic dispersion in deionized water 6 times the mass of the boron nitride powder for 4h, then centrifuge at 8000r / min, take the supernatant and vacuum dry at 60℃. After complete drying, grind in an agate mortar and sieve, then obtain the hydroxylated boron nitride powder;

[0064] S2. Take 0.08 times the mass of the hydroxylated boron nitride powder 3-aminopropyl triethoxysilane, add it to 0.24 times the mass of the hydroxylated boron nitride powder 95% ethanol aqueous solution, magnetically stir for 28min, then add the hydroxylated boron nitride powder, stir in a water bath at 60℃ for 2h. After the reaction is completed, use anhydrous ethanol to wash three times by centrifugation to remove unreacted 3-aminopropyl triethoxysilane, and finally vacuum dry at 60℃. After grinding and sieving, the pre-modified boron nitride powder is obtained;

[0065] S3. Weigh 10g of pre-modified boron nitride powder and add it to 70g of 10% mass fraction hydrochloric acid solution, ultrasonic dispersion for 2.5h to obtain a pre-modified boron nitride powder dispersion; Weigh 9g of aniline and add it to 36g of 10% mass fraction hydrochloric acid solution, magnetically stir until completely dissolved to obtain an aniline solution; Weigh 1.1g of ammonium persulfate, 1.4g of potassium dichromate, and 10g of 10% mass fraction hydrochloric acid solution to obtain a catalyst solution; Add the aniline solution to the pre-modified boron nitride powder dispersion, magnetically stir for 50min, then add the catalyst solution dropwise within 30min to initiate polymerization, and continue the reaction for 23h. After the reaction is completed, wash with water and ethanol three times by centrifugation, then dry in a 60℃ vacuum drying oven, and finally grind and sieve to obtain the modified filler.

[0066] The defoaming agent is BYK-066; the adhesion promoter is KH-560; the solvent is xylene; and the dispersant is BYK-110;

[0067] The curing agent monomer is 3,3'-diamino-2,2'-dipyridine, and the specific preparation steps of 3,3'-diamino-2,2'-dipyridine are as follows:

[0068] Into a container, 50 g of stannous chloride, 200 g of concentrated hydrochloric acid, 10 g of 3,3'-dinitro-2,2'-dipyridyl were sequentially added, and reacted at 90°C for 1 h, neutralized to pH 8 using sodium hydroxide, and after extraction with dichloromethane, the residue was recrystallized in deionized water to obtain 3,3'-diamino-2,2'-dipyridyl.

[0069] The low surface tolerance agent is N-aminopropyl morpholine;

[0070] The plasticizing cosolvent is benzyl alcohol;

[0071] The curing accelerator is salicylic acid.

[0072] A 500 mm x 500 mm x 3 mm cold-rolled steel plate with rust on the surface was selected, manually polished to a surface cleanliness of St2, St3 grade, 50 g of component A and 10 g of component B were mixed uniformly, and then a 300 μm thick high-adhesion anticorrosive epoxy coating for maintenance was sprayed on the St2, St3 grade cold-rolled steel plate, and cured at 60°C for 15 h to obtain an anticorrosion treated steel plate.

[0073] Example 2

[0074] A preparation method of a high-adhesion anticorrosive epoxy coating, comprising the following steps:

[0075] (1) 22 g of a first resin base material, 5 g of a second resin base material, 60 g of a modified filler, 0.7 g of a dispersing agent, 0.7 g of a defoaming agent, 0.7 g of an adhesion promoter, and 7 g of a solvent were mixed uniformly to obtain component A;

[0076] (2) 65 g of a curing agent monomer 3,3'-diamino-2,2'-dipyridyl, 5 g of a low surface tolerance agent, 25 g of a plasticizing cosolvent, and 6 g of a curing accelerator were mixed to obtain component B;

[0077] (3) 65 g of component A and 10 g of component B were packaged separately and ready for use to obtain a high-adhesion anticorrosive epoxy coating for maintenance.

[0078] The first resin base material is E-44 epoxy resin with an epoxy value not less than 0.40;

[0079] The second resin base material is German Lutg liquid petroleum resin Novares LA700;

[0080] The preparation steps of the modified filler include:

[0081] S1. Boron nitride powder was placed in a ceramic crucible, placed in the center of the tube furnace, and a crucible filled with deionized water was placed on one side of the tube furnace. The tube furnace was set to an heating rate of 10℃ / min, heated to 1000℃ for 2h, and then naturally cooled to room temperature. Then the boron nitride powder was ultrasonically dispersed in 7 times the mass of deionized water for 5h, and then centrifuged at a speed of 8000r / min. The supernatant was vacuum dried at 60℃, and then ground in a agate mortar and sieved to obtain the hydroxylated boron nitride powder.

[0082] S2. 3-Aminopropyltriethoxysilane was added to the hydroxylated boron nitride powder, and the mixture was stirred for 30min under magnetic stirring. Then, the hydroxylated boron nitride powder was added and stirred in a water bath at 60℃ for 2h. After the reaction was completed, the unreacted 3-aminopropyltriethoxysilane was removed by centrifugation with anhydrous ethanol three times. Finally, the pre-modified boron nitride powder was obtained by vacuum drying at 60℃ and sieving.

[0083] S3. 10g of pre-modified boron nitride powder was added to 75g of 10% mass fraction hydrochloric acid solution and ultrasonically dispersed for 3h to obtain a pre-modified boron nitride powder dispersion. 10g of aniline was added to 40g of 10% mass fraction hydrochloric acid solution and stirred until completely dissolved to obtain an aniline solution. 1.2g of ammonium persulfate, 1.6g of potassium dichromate, and 11.2g of 10% mass fraction hydrochloric acid solution were mixed to obtain a catalyst solution. The aniline solution was added to the pre-modified boron nitride powder dispersion and stirred for 60min under magnetic stirring. Then, the catalyst solution was added dropwise within 30min to initiate polymerization. The reaction was continued for 24h. After the reaction was completed, the product was washed with water and ethanol three times by centrifugation. Then, the product was dried in a vacuum drying oven at 60℃. Finally, the modified filler was obtained by sieving.

[0084] The defoaming agent was BYK-066; the adhesion promoter was KH-560; the solvent was xylene; and the dispersant was BYK-110.

[0085] The curing agent monomer was 3,3'-diamino-2,2'-bipyridine. The specific preparation steps of 3,3'-diamino-2,2'-bipyridine were as follows:

[0086] 65g of stannous chloride, 250g of concentrated hydrochloric acid, and 10g of 3,3'-dinitro-2,2'-bipyridine were sequentially added to a container. The mixture was reacted at 95℃ for 1.5h. The reaction mixture was neutralized to pH 8.5 using sodium hydroxide. The residue was extracted with dichloromethane and recrystallized in deionized water to obtain 3,3'-diamino-2,2'-bipyridine.

[0087] The low surface tension agent was N-aminopropylmorpholine.

[0088] The plasticizing cosolvent is benzyl alcohol;

[0089] The curing accelerator is salicylic acid.

[0090] A 500mm x 500mm x 3mm cold-rolled steel plate with rust on the surface is selected, and is manually polished to a surface cleanliness of St2, St3 grade. The 65g of component A and 10g of component B prepared in the examples and comparative examples are mixed uniformly, and then a 300μm thick high-adhesion anticorrosive epoxy coating for maintenance is sprayed on the cold-rolled steel plate of St2, St3 grade, and is cured at 70℃ for 22h to obtain an anticorrosion treated steel plate.

[0091] Example 3

[0092] A preparation method of a high-adhesion anticorrosive epoxy coating, comprising the following steps:

[0093] (1) 28g of the first resin base material, 7g of the second resin base material, 70g of the modified filler, 0.9g of the dispersing agent, 0.9g of the defoaming agent, 0.9g of the adhesion promoter, and 9g of the solvent are mixed uniformly to obtain component A;

[0094] (2) 70g of the curing agent monomer 3,3'-diamino-2,2'-dipyridyl, 6g of the low surface tolerance agent, 30g of the plasticizing cosolvent, and 8g of the curing accelerator are mixed to obtain component B;

[0095] (3) 80g of component A and 10g of component B are packaged separately and ready for use to obtain a high-adhesion anticorrosive epoxy coating for maintenance.

[0096] The first resin base material is E-44 epoxy resin with an epoxy value not less than 0.40;

[0097] The second resin base material is German Lutg liquid petroleum resin Novares LA700;

[0098] The preparation steps of the modified filler include:

[0099] S1. The boron nitride powder is placed in a ceramic crucible and placed in the center of a tube furnace. A crucible filled with deionized water is placed on one side of the tube furnace. The tube furnace is set to an heating rate of 12℃ / min, heated to 1100℃ for 2.5h, and then naturally cooled to room temperature. Then the boron nitride powder is ultrasonically dispersed in deionized water with a mass of 8 times the boron nitride powder for 6h, and then centrifuged at a speed of 8000r / min. The supernatant is vacuum dried at 60℃. After complete drying, it is ground in an agate mortar and sieved to obtain hydroxylated boron nitride powder;

[0100] S2. Take 0.12 times the mass of the hydroxylated boron nitride powder of 3-aminopropyl triethoxysilane, add it to 0.36 times the mass of the hydroxylated boron nitride powder of 95% ethanol aqueous solution, magnetically stir for 32 min, then add the hydroxylated boron nitride powder, stir in a water bath at 60°C for 2h, after the reaction is completed, use anhydrous ethanol to centrifuge and wash three times to remove unreacted 3-aminopropyl triethoxysilane, and finally vacuum dry at 60°C, grind and sieve to obtain a pre-modified boron nitride powder;

[0101] S3. Weigh 10g of pre-modified boron nitride powder into 80g of 10% hydrochloric acid solution, ultrasonic dispersion for 3.5h, to obtain a pre-modified boron nitride powder dispersion; weigh 11g of aniline, add it to 44g of 10% hydrochloric acid solution, magnetically stir until completely dissolved, to obtain an aniline solution; weigh 1.3g of ammonium persulfate, 1.8g of potassium dichromate, and 12.4g of 10% hydrochloric acid solution, to obtain a catalyst solution; add the aniline solution to the pre-modified boron nitride powder dispersion, magnetically stir for 70min, then add the catalyst solution dropwise within 35min to initiate polymerization, and continue the reaction for 25h, after the reaction is completed, use water and ethanol to centrifuge and wash three times, then put it into a vacuum drying oven at 60°C, grind and sieve to obtain a modified filler.

[0102] The defoaming agent is BYK-066; the adhesion promoter is KH-560; the solvent is xylene; and the dispersant is BYK-110;

[0103] The curing agent monomer is 3,3'-diamino-2,2'-dipyridine, and the specific preparation steps of 3,3'-diamino-2,2'-dipyridine are as follows:

[0104] Into a container, add 80g of stannous chloride, 300g of concentrated hydrochloric acid, and 10g of 3,3'-dinitro-2,2'-dipyridine in sequence, react at 100°C for 2h, neutralize to pH 9 using sodium hydroxide, extract with dichloromethane, and then recrystallize the residue in deionized water to obtain 3,3'-diamino-2,2'-dipyridine.

[0105] The low surface tolerance agent is N-aminopropyl morpholine;

[0106] The plasticizing cosolvent is benzyl alcohol;

[0107] The curing accelerator is salicylic acid.

[0108] A 500 mm x 500 mm x 3 mm cold-rolled steel plate with rust on the surface was selected, and was manually polished to a surface cleanliness of St2, St3 grade. 80 g of component A and 10 g of component B prepared in the examples and comparative examples were mixed uniformly, and then a 300 pm thick high-adhesion anticorrosive epoxy coating for maintenance was sprayed on the cold-rolled steel plate of St2, St3 grade, and was cured at 80°C for 30 h to obtain an anticorrosion treated steel plate.

[0109] Comparative Example 1

[0110] The difference from Example 2 is that component A of Comparative Example 1 is compounded from a first resin base, a second resin base, boron nitride nano powder, a dispersing agent, an antifoaming agent, an adhesion promoter, and a solvent; the remaining components and steps are the same as those of Example 2.

[0111] Comparative Example 2

[0112] The difference from Example 2 is that component A of Comparative Example 2 is compounded from a first resin base, a second resin base, 3-aminopropyl triethoxysilane pre-modified hydroxylated boron nitride powder, a dispersing agent, an antifoaming agent, an adhesion promoter, and a solvent; the remaining components and steps are the same as those of Example 2.

[0113] Comparative Example 3

[0114] The difference from Example 2 is that component B of Comparative Example 3 is compounded from modified polyamide Henschel Aradur 450BD, a low surface tolerance agent, a cosolvent plasticizer, and a curing accelerator; the remaining components and steps are the same as those of Example 2.

[0115] Comparative Example 4

[0116] The difference from Example 2 is that the high-adhesion anticorrosive epoxy coating for maintenance of Comparative Example 4 is cured at room temperature, i.e., at 25°C; the remaining components and steps are the same as those of Example 2.

[0117] Comparative Example 5

[0118] The difference from Example 2 is that the high-adhesion anticorrosive epoxy coating for maintenance of Comparative Example 5 is cured at 59°C; the remaining components and steps are the same as those of Example 2.

[0119] Comparative Example 6

[0120] The difference from Example 2 is that the high-adhesion anticorrosive epoxy coating for maintenance of Comparative Example 6 is cured at 81°C; the remaining components and steps are the same as those of Example 2.

[0121] Performance detection

[0122] The epoxy coatings prepared in Examples 1-3 and Comparative Examples 1-6 of the present application were subjected to index testing, and the index testing methods were as follows:

[0123] A 500 mm x 500 mm x 3 mm cold-rolled steel plate with rust on the surface was manually polished to a surface cleanliness of St2, St3 grade, and the components A and B prepared in the examples and comparative examples were mixed uniformly, and then a 300 ± 30 μm thick high-adhesion anticorrosive epoxy coating for maintenance was sprayed on the cold-rolled steel plate of St2, St3 grade, and after curing, an anticorrosion treated steel plate was obtained.

[0124] Corrosion resistance: The anticorrosion treated steel plate was tested according to GB / T9274-1988 Method A, and the test medium was 5% sodium chloride solution, and the final evaluation allowed discoloration and loss of luster. After 4200 h, the final evaluation allowed discoloration and loss of luster, and the paint film was free of phenomena such as blistering, cracking, and peeling. Then it was evaluated as "complying with requirements".

[0125] Adhesion: The anticorrosion treated steel plate was tested according to GB / T5210-2006.

[0126] Table 1 shows the analysis results of the anticorrosion performance and adhesion of the epoxy coatings prepared in Examples 1-3 and Comparative Examples 1-6 of the present application.

[0127] Table 1

[0128]

[0129] It can be found from Table 1 that the high-adhesion anticorrosive epoxy coatings for maintenance prepared in Examples 1, 2, and 3 have good anticorrosion performance and large adhesion. It can be found from the experimental data of Examples 1, 2, and 3 and Comparative Examples 1 and 2 that the high-adhesion anticorrosive epoxy coatings for maintenance prepared using the modified filler obtained by mixing reaction of aniline, hydroxylated boron nitride powder, and 3-aminopropyl triethoxysilane have good anticorrosion performance and large adhesion. It can be found from the experimental data of Examples 1, 2, and 3 and Comparative Example 3 that the high-adhesion anticorrosive epoxy coatings for maintenance prepared using 3,3'-diamino-2,2'-bipyridine as the curing agent monomer to prepare component B have good anticorrosion performance and large adhesion. It can be found from the experimental data of Examples 1, 2, and 3 and Comparative Examples 4, 5, and 6 that the high-adhesion anticorrosive epoxy coatings for maintenance prepared using curing at 60-80°C have large adhesion.

[0130] The examples of the specific embodiments are preferred embodiments of the present application, and do not limit the protection scope of the present application, and therefore: any equivalent changes made according to the structure, shape, principle of the present application should be covered within the protection scope of the present application.

Claims

1. A high adhesion corrosion control epoxy coating, characterized by: The component A comprises the following components by weight: 50-80 parts of a first resin base, 10 parts of a second resin base, 50-70 parts of a modified filler, 0.5-0.9 parts of a dispersing agent, 0.5-0.9 parts of an antifoaming agent, 0.5-0.9 parts of an adhesion promoter, and 5-9 parts of a solvent; The component A comprises the following components by weight: 16-28 parts of a first resin base, 3-7 parts of a second resin base, 50-70 parts of a modified filler, 0.5-0.9 parts of a dispersing agent, 0.5-0.9 parts of an antifoaming agent, 0.5-0.9 parts of an adhesion promoter, and 5-9 parts of a solvent; The component B comprises the following components by weight: 60-70 parts of a curing agent monomer, 4-6 parts of a low surface tolerance agent, 20-30 parts of a plasticization cosolvent, and 4-8 parts of a curing accelerator; The modified filler is obtained by mixing and reacting aniline, hydroxylated boron nitride powder, and 3-aminopropyl triethoxysilane; and the curing agent monomer is 3,3'-diamino-2,2'-dipyridyl. The first resin base is an epoxy resin with an epoxy value not less than 0.

40. The second resin base is any one or several of unsaturated polyester resin, alkyl glycidyl ether, cashew shell oil phenol aldehyde resin polyol, cashew phenol glycidyl ether, and German Lutgol liquid petroleum resin Novares LA700. The preparation method of the modified filler comprises the following steps: a. 0.08-0.12 times the mass of the hydroxylated boron nitride powder of 3-aminopropyl triethoxysilane is added to an ethanol solution with 0.24-0.36 times the mass of the hydroxylated boron nitride powder, stirred, and then the hydroxylated boron nitride powder is added, stirred in a water bath at 58-62℃ for 1.8-2.2h, washed and dried after the reaction is completed, ground and sieved to obtain a pre-modified boron nitride powder; b. 10 parts by weight of the pre-modified boron nitride powder prepared in step a is added to 70-80 parts by weight of a hydrochloric acid solution, and a pre-modified boron nitride powder dispersion is obtained after dispersion; 9-11 parts by weight of aniline is added to 36-44 parts by weight of a hydrochloric acid solution, and an aniline solution is obtained after dissolution; 1.1-1.3 parts by weight of ammonium persulfate, 1.4-1.8 parts by weight of potassium dichromate, and 10-12.4 parts by weight of a hydrochloric acid solution are mixed to obtain a catalyst solution; The aniline solution is added to the pre-modified boron nitride powder dispersion, stirred, and the catalyst solution is added dropwise within 25-35min to initiate polymerization, the reaction is continued for 23-25h, and the reaction is washed and dried after completion, ground and sieved to obtain the modified filler; The low surface tolerance agent is any one or several of N-aminopropyl morpholine, KH-550, KH-792, Hymenstecen 1121, and AkzoNobel Duomeen TDO.

2. A high adhesion anticorrosive epoxy coating as claimed in claim 1, wherein: The preparation method of the hydroxylated boron nitride powder comprises the following steps: The boron nitride powder is heated at a heating rate of 8-12℃ / min to 900-1100℃, kept for 1.5-2.5h, ultrasonically dispersed in water with 6-8 times the mass of the boron nitride powder for 4-6h, centrifuged to obtain the supernatant, dried and ground to obtain the hydroxylated boron nitride powder.

3. A high adhesion anticorrosive epoxy coating as claimed in claim 1, wherein: The preparation method of the 3,3'-diamino-2,2'-dipyridyl comprises the following steps: Mix 50-80 parts by weight of stannous chloride, 200-300 parts by weight of concentrated hydrochloric acid and 10 parts by weight of 3,3'-dinitro-2,2'-dipyridyl, and react at 90-100°C for 1-2 hours, adjust the pH to 8-9, extract with dichloromethane, and recrystallize the residue in water to obtain 3,3'-diamino-2,2'-dipyridyl.

4. A method for preparing a high-adhesion anti-corrosion epoxy coating according to any one of claims 1-3, characterized in that: The method comprises the following steps: S1. Mix a prescribed amount of a first resin base, a second resin base, a modified filler, a dispersing agent, an antifoaming agent, an adhesion promoter and a solvent to obtain component A; S2. Mix a prescribed amount of a curing agent monomer, a low surface tolerance agent, a plasticizing cosolvent and a curing promoter to obtain component B; S3. Package the prescribed amount of component A and component B separately for standby use to obtain high-adhesion corrosion-resistant epoxy paint.

5. A method of using the high adhesion corrosion protective epoxy coating as claimed in any one of claims 1 to 3, characterized in that: The method comprises the following steps: Mix a prescribed amount of component A and component B, and then spray a high-adhesion corrosion-resistant epoxy paint with a thickness of 300-1000 microns on a steel facility in a splashing area, and cure at 60-80°C for 15-30 hours.

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