An inorganic zinc-rich coating, its preparation method and application

Abstract

The present invention relates to an inorganic zinc-rich coating, its preparation method and application, and belongs to the technical field of coatings. The inorganic zinc-rich coating includes component A and component B. By weight, component A includes the following raw materials: 75-85 parts of a silicate solution and 0.5-2 parts of an auxiliary agent. By weight, component B includes the following raw materials: 10-20 parts of modified zinc powder and 25-35 parts of zinc powder. The modified zinc powder is obtained by compound modification of zinc powder with a pyridine crown ether ring compound and an amino silane coupling agent. The silicate solution is obtained by compounding a lithium silicate solution and a potassium silicate solution. The modulus of the lithium silicate is 3-5, and the modulus of the potassium silicate is 5-6.5. By using a silicate solution with a suitable modulus as the base material and introducing specific modified zinc powder at the same time, the present invention significantly improves the anti-slip performance and adhesion performance of the inorganic zinc-rich coating, and can meet the use requirements of steel structures such as high-strength bolts.

Description

Technical Field

[0001] The present invention relates to the technical field of coatings, and in particular to an inorganic zinc-rich coating, a preparation method thereof, and an application thereof. Background Art

[0002] As one of the main connection forms of welded steel structures, high-strength bolt connections have the advantages of good mechanical properties, fatigue resistance, good seismic performance, high connection stiffness, and simple construction. Therefore, they are widely used in the on-site connections of building steel structures and bridge steel structures. For high-strength bolt connections, the anti-slip coefficient of the contact friction surface of the connecting plate is an important factor affecting the connection bearing capacity. When the specifications and quantities of the connecting bolts are determined, the treatment method of the friction surface and the anti-slip coefficient value become the main parameters for determining the bearing capacity of the friction surface connection. Therefore, in the construction of high-strength bolt connections, the treatment of the friction surface of the connecting plate is crucial.

[0003] However, the anti-corrosion coatings currently used for steel structures and high-strength bolts have many disadvantages. First, the anti-slip coefficient is relatively low. The anti-slip coefficients of market products are mostly in the range of 0.35 to 0.50, which cannot meet the requirement of the industry standard that the initial anti-slip coefficient of the coating ≥ 0.55. Second, due to the strong shrinkage stress during the film-forming process of traditional inorganic zinc-rich coatings, the film-forming property is poor, and the attenuation rate of the anti-slip coefficient is relatively fast (the industry standard requires that the anti-slip coefficient of the coating ≥ 0.45 after 6 months of outdoor use), and the adhesion after film-forming is low and it is easy to fall off, which cannot provide lasting and stable protection for high-strength bolts. Summary of the Invention

[0004] To solve the above problems, the present invention provides an inorganic zinc-rich coating, a preparation method thereof, and an application thereof.

[0005] In a first aspect, the present invention provides an inorganic zinc-rich coating, and the inorganic zinc-rich coating includes component A and component B;

[0006] By weight, component A includes the following raw materials: 75 - 85 parts of a silicate solution and 0.5 - 2 parts of an auxiliary agent;

[0007] By weight, component B includes the following raw materials: 10 - 20 parts of modified zinc powder and 25 - 35 parts of zinc powder;

[0008] The modified zinc powder is obtained by compound-modifying zinc powder with a pyridine crown ether ring compound and an amino silane coupling agent;

[0009] The silicate solution is obtained by compounding a lithium silicate solution and a potassium silicate solution, the modulus of the lithium silicate is 3 - 5, and the modulus of the potassium silicate is 5 - 6.5.

[0010] Further, the weight ratio of the component A to the component B is 1:(1.8 - 2.3).

[0011] Further, by weight parts, the component A comprises the following raw materials: 80 parts of silicate solution and 1.5 parts of auxiliary agent; by weight parts, the component B comprises the following raw materials: 15 parts of modified zinc powder and 30 parts of zinc powder.

[0012] Further, the weight ratio of the lithium silicate solution to the potassium silicate solution is (1 - 2):(5 - 8); by weight percentage, the solid content of the lithium silicate solution is 19 - 24%; by weight percentage, the solid content of the potassium silicate solution is 24 - 26%.

[0013] Further, the preparation method of the modified zinc powder comprises the following process:

[0014] Perform the first stirring on 2,2'-bipyridine-5,5'-dicarboxaldehyde and trifluoromethanesulfonic acid, then filter and recrystallize to obtain 2H + -BPDA;

[0015] Perform the second stirring on the 2H + -BPDA and dibenzo-24-crown-8, then remove the solvent to obtain the pyridine crown ether ring compound;

[0016] Add the amino silane coupling agent and zinc powder into absolute ethanol for the third stirring, then add the pyridine crown ether ring compound for the fourth stirring, filtration, washing and drying to obtain the modified zinc powder;

[0017] Wherein, the molar ratio of the 2,2'-bipyridine-5,5'-dicarboxaldehyde to the trifluoromethanesulfonic acid is (0.45 - 0.50):(1.1 - 1.3); the molar ratio of the 2H + -BPDA to the dibenzo-24-crown-8 is 1:1; the weight ratio of the pyridine crown ether ring compound, the amino silane coupling agent, the zinc powder and the absolute ethanol is (1 - 1.5):(0.5 - 1):(2.2 - 3):(10 - 20).

[0018] Further, the working condition parameters of the first stirring include: the temperature is 0 - 5°C and the stirring time is 3.5 - 5 hours; the working condition parameters of the second stirring include: the temperature is room temperature and the stirring time is 20 - 30 hours; the working condition parameters of the third stirring include: the temperature is 50 - 60°C and the stirring time is 1 - 2 hours; the working condition parameters of the fourth stirring include: the temperature is 50 - 60°C and the stirring time is 1 - 2 hours; the amino silane coupling agent includes at least one of N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane and 3-aminopropyltrimethoxysilane.

[0019] Further, the auxiliary agent is composed of a thickener and an antifoaming agent with a weight ratio of (3-5):1; the particle size of the zinc powder is 500-800 mesh.

[0020] In a second aspect, the present invention provides a method for preparing the inorganic zinc-rich coating according to any one of the first aspect, and the preparation method includes the following steps:

[0021] Stir and mix the raw materials in component A to obtain component A;

[0022] Add the raw materials in component B to component A and stir and mix to obtain the inorganic zinc-rich coating.

[0023] In a third aspect, the present invention provides an application of the inorganic zinc-rich coating according to any one of the first aspect and the second aspect in treating the bolt connection surface.

[0024] The above technical solutions provided by the embodiments of the present invention have at least the following advantages compared with the prior art:

[0025] The embodiments of the present invention provide an inorganic zinc-rich coating, its preparation method and application. By using a silicate solution with a suitable modulus as the base material and introducing specific modified zinc powder, the present invention significantly improves the anti-slip performance and adhesion of the inorganic zinc-rich coating, and can meet the use requirements of steel structures such as high-strength bolts. Specifically:

[0026] 1. Function of the silicate solution

[0027] Film-forming performance: The silicate solution is the main film-forming substance of the inorganic zinc-rich coating, and has good compatibility with the raw materials in component B, forming a network polymer film, obtaining a solid protective film to protect the substrate from corrosion.

[0028] Adhesion improvement: The silicate solution has good adhesion to the metal surface, which benefits from the chemical bonding formed between the silicate and the metal surface. At the same time, the silicate solution can also chemically react with the modified zinc powder and the zinc powder to further enhance the adhesion of the coating.

[0029] Anti-slip performance: Lithium silicate and potassium silicate in the silicate solution have a suitable modulus, which can form a coating surface with a certain roughness and friction, thereby improving the anti-slip performance of the coating.

[0030] 2. Function of the modified zinc powder

[0031] Rust and corrosion prevention: The modified zinc powder is compound-modified with a pyridine crown ether ring compound and an amino silane coupling agent, so that a dense protective film is formed on the surface of the zinc powder, effectively blocking the intrusion of water molecules and corrosion media, thereby playing a role in rust and corrosion prevention.

[0032] Enhanced adhesion: There is good compatibility and reactivity between the modified zinc powder and the silicate solution, which can form a strong chemical bonding effect, further enhancing the adhesion of the coating.

[0033] Improved anti-slip performance: The addition of the modified zinc powder can also improve the anti-slip performance of the coating. This is because the introduction of a special pyridine crown ether ring structure has a certain steric hindrance, causing the modified zinc powder to form micro bulges and undulations in the coating, increasing the roughness and friction of the coating surface, and further enhancing the anti-slip performance.

[0034] 3. Functions of zinc powder

[0035] Electrochemical protection: As the main anti-corrosion component of inorganic zinc-rich coatings, zinc powder can provide electrochemical protection. Since zinc is more active than iron and has a more negative potential than iron, in an electrolyte solution, zinc atoms are easily oxidized to lose electrons, thus protecting steel from corrosion.

[0036] Enhanced adhesion: Chemical reactions can occur between zinc powder, silicate solution and modified zinc powder to form a strong chemical bonding effect, which helps to improve the adhesion of the coating.

[0037] 4. Functions of additives

[0038] Improve construction performance: Additives can improve the viscosity of the coating, enhance the defoaming, wetting and leveling properties of the coating, thereby improving the construction performance of the coating.

[0039] Enhance film-forming performance: Additives can also promote the hydrolysis and polycondensation reactions of the silicate solution, accelerate the film formation and curing processes of the coating, and improve the film-forming performance of the coating.

[0040] In summary, the present invention uses a silicate solution with an appropriate modulus as the base material, introduces specific modified zinc powder and zinc powder as anti-corrosion components, and supplements with additives to improve the construction performance and film-forming performance, achieving a significant improvement in the comprehensive performance such as anti-slip performance and adhesion of inorganic zinc-rich coatings. It is particularly suitable for the treatment of high-strength bolt connection surfaces of steel components such as bridges and prefabricated buildings. Its excellent performance can effectively protect the connection surface from corrosion and wear, provide durable and stable protection for high-strength bolts, and thus improve the service life and safety of the connection surface. Specific embodiments

[0041] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Apparently, the described embodiments are some, but not all, of the embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the scope of protection of the present invention.

[0042] Unless otherwise specifically stated, all kinds of raw materials, reagents, instruments, and equipment used in the present invention can be obtained through market purchases or can be prepared by existing methods.

[0043] In a first aspect, the present invention provides an inorganic zinc-rich coating, and the inorganic zinc-rich coating includes component A and component B;

[0044] By weight, component A includes the following raw materials: 75 - 85 parts of a silicate solution and 0.5 - 2 parts of an auxiliary agent;

[0045] By weight, component B includes the following raw materials: 10 - 20 parts of modified zinc powder and 25 - 35 parts of zinc powder;

[0046] The modified zinc powder is obtained by compound-modifying zinc powder with a pyridine crown ether ring compound and an amino silane coupling agent;

[0047] The silicate solution is obtained by compounding a lithium silicate solution and a potassium silicate solution. The modulus of the lithium silicate is 3 - 5, and the modulus of the potassium silicate is 5 - 6.5.

[0048] The embodiments of the present invention provide an inorganic zinc-rich coating. By using a silicate solution with a suitable modulus as the base material and introducing a specific modified zinc powder at the same time, the anti-slip performance and adhesion performance of the inorganic zinc-rich coating are significantly improved, which can meet the usage requirements of steel structures such as high-strength bolts.

[0049] In some specific embodiments, the silicate solution can be directly compounded using commercially available products such as those from Zhejiang Yuda Chemical Co., Ltd., Hubei Xinyuhong Biomedical Technology Co., Ltd., and Wuhan Jiyesheng Chemical Co., Ltd.; or it can be self-made according to the existing silicate preparation process and then compounded with water. Preferably, the modulus of the lithium silicate is 4.8, and the modulus of the potassium silicate is 5.6.

[0050] In some specific embodiments, the weight ratio of component A to component B is 1:(1.8 - 2.3), and preferably 1:2.

[0051] In some specific embodiments, based on parts by weight, the A component comprises the following raw materials: 80 parts of a silicate solution and 1.5 parts of an auxiliary agent; based on parts by weight, the B component comprises the following raw materials: 15 parts of modified zinc powder and 30 parts of zinc powder.

[0052] In some specific embodiments, the weight ratio of the lithium silicate solution to the potassium silicate solution is (1 - 2):(5 - 8), preferably 1.5:7; based on weight percentage, the solid content of the lithium silicate solution is 19 - 24%, preferably 22%; based on weight percentage, the solid content of the potassium silicate solution is 24 - 26%, preferably 25%.

[0053] In some specific embodiments, the preparation method of the modified zinc powder comprises the following process:

[0054] Perform a first stirring on 2,2'-bipyridine-5,5'-dicarboxaldehyde and trifluoromethanesulfonic acid, then filter and recrystallize to obtain 2H + -BPDA;

[0055] Perform a second stirring on the 2H + -BPDA and dibenzo-24-crown-8, then remove the solvent to obtain the pyridine crown ether ring compound;

[0056] Add an amino silane coupling agent and zinc powder into absolute ethanol for a third stirring, then add the pyridine crown ether ring compound for a fourth stirring, filtration, washing and drying to obtain the modified zinc powder;

[0057] Wherein, the molar ratio of the 2,2'-bipyridine-5,5'-dicarboxaldehyde to the trifluoromethanesulfonic acid is (0.45 - 0.50):(1.1 - 1.3), preferably 0.47:1.2; the molar ratio of the 2H + -BPDA to the dibenzo-24-crown-8 is 1:1; the weight ratio of the pyridine crown ether ring compound, the amino silane coupling agent, the zinc powder and the absolute ethanol is (1 - 1.5):(0.5 - 1):(2.2 - 3):(10 - 20).

[0058] In some specific embodiments, the working condition parameters of the first stirring include: the temperature is 0 - 5°C, and it can be operated in an ice-water bath environment; the stirring time is 3.5 - 5 hours; the working condition parameters of the second stirring include: the temperature is room temperature, and the stirring time is 20 - 30 hours; the working condition parameters of the third stirring include: the temperature is 50 - 60°C, and the stirring time is 1 - 2 hours; the working condition parameters of the fourth stirring include: the temperature is 50 - 60°C, and the stirring time is 1 - 2 hours; the amino silane coupling agent includes at least one of N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane and 3-aminopropyltrimethoxysilane.

[0059] In some specific embodiments, the auxiliary agent is composed of a thickener and an antifoaming agent with a weight ratio of (3 - 5):1. The thickener can be directly a commercially available polyurethane thickener such as PU-40, etc., and the antifoaming agent can be directly a commercially available silicone antifoaming agent such as BYK-1789; the particle size of the zinc powder is 500 - 800 mesh.

[0060] In a second aspect, based on the same inventive concept, the present invention provides a preparation method of the inorganic zinc-rich coating according to any one of the first aspect, and the preparation method includes the following steps:

[0061] Stir and mix the raw materials in component A to obtain component A;

[0062] Add the raw materials in component B to component A and stir and mix to obtain the inorganic zinc-rich coating.

[0063] The preparation method of the inorganic zinc-rich coating of the present invention is simple to operate, does not require additional specific equipment, and is suitable for batch industrial production. At the same time, this preparation method is realized based on the inorganic zinc-rich coating according to any one of the first aspect, so it has at least the beneficial effects according to any one of the first aspect, which will not be elaborated here one by one.

[0064] In a third aspect, based on the same inventive concept, the present invention provides an application of the inorganic zinc-rich coating according to any one of the first aspect and the second aspect in treating the bolt connection surface.

[0065] The inorganic zinc-rich coating provided by the present invention has excellent anti-slip performance, adhesion and other properties, and is particularly suitable for treating the high-strength bolt connection surfaces of steel components such as bridges and prefabricated buildings. Its excellent properties can effectively protect the connection surface from corrosion and wear, provide lasting and stable protection for high-strength bolts, thereby improving the service life and safety of the connection surface.

[0066] It should be noted that for the component raw materials involved in the inorganic zinc-rich coating, its preparation method and application provided in the embodiments of the present invention, without special limitation or specific description, can be directly commercially available products or prepared by existing publicly disclosed preparation methods; at the same time, for the steps and parameters involved, without special limitation or specific description, they can be carried out according to the existing inorganic zinc-rich coating processing technology or directly using existing equipment, and the present invention document will not elaborate one by one.

[0067] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. The experimental methods without specific conditions noted in the following embodiments are generally determined according to national standards. If there is no corresponding national standard, they are carried out according to general international standards, conventional conditions, or conditions recommended by the manufacturer.

[0068] Example 1

[0069] This example provides an inorganic zinc-rich coating, and the inorganic zinc-rich coating includes component A and component B with a weight ratio of 1:2;

[0070] By weight, component A includes the following raw materials: 80 parts of silicate solution and 1.5 parts of auxiliary agent;

[0071] By weight, component B includes the following raw materials: 15 parts of modified zinc powder and 30 parts of zinc powder;

[0072] The modified zinc powder is obtained by compound modification of zinc powder with pyridine crown ether ring compounds and amino silane coupling agents;

[0073] The silicate solution is obtained by compounding lithium silicate solution and potassium silicate solution with a weight ratio of 1.5:7; the modulus of the lithium silicate is 4.8, and the modulus of the potassium silicate is 5.6; by weight percentage, the solid content of the lithium silicate solution is 22%; by weight percentage, the solid content of the potassium silicate solution is 25%;

[0074] The auxiliary agent is composed of a thickener and an antifoaming agent with a weight ratio of 4:1;

[0075] The particle size of the zinc powder is 700 mesh;

[0076] The preparation method of the modified zinc powder includes the following process:

[0077] Dissolve 2,2'-bipyridine-5,5'-dicarboxaldehyde in dichloromethane solvent, and then stir in an ice-water bath for 15 minutes; then drop trifluoromethanesulfonic acid dissolved in dichloromethane into the reaction system and stir for 4 hours. The molar ratio of 2,2'-bipyridine-5,5'-dicarboxaldehyde to trifluoromethanesulfonic acid is 0.47:1.2; after the reaction is completed, filter to obtain a pale yellow solid, and recrystallize in acetonitrile and diethyl ether to obtain 2H + -BPDA (white solid);

[0078] Mix the 2H + -BPDA and dibenzo-24-crown-8 with a molar ratio of 1:1 and add them to ethanol for stirring at room temperature for 24 hours, and then carry out rotary evaporation to remove the solvent and drying to obtain the pyridine crown ether ring compound (yellow solid);

[0079] An amino-silane coupling agent (specifically N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane) and zinc powder are added to absolute ethanol, and stirred at 55 °C for 1.5 hours. Then the pyridine crown ether ring compound is added and stirring is continued at 55 °C for 1.5 hours, followed by filtration, washing and drying to obtain the modified zinc powder; wherein, the weight ratio of the pyridine crown ether ring compound, the amino-silane coupling agent, the zinc powder and the absolute ethanol is 1.2:0.8:2.5:15.

[0080] The preparation method of the above inorganic zinc-rich coating comprises the following steps:

[0081] Stir and mix the raw materials in component A to obtain component A;

[0082] Add the raw materials in component B to component A and stir and mix to obtain the inorganic zinc-rich coating.

[0083] Example 2

[0084] This example provides an inorganic zinc-rich coating, which comprises component A and component B with a weight ratio of 1:1.8;

[0085] By weight, component A comprises the following raw materials: 75 parts of a silicate solution and 0.5 part of an auxiliary agent;

[0086] By weight, component B comprises the following raw materials: 10 parts of modified zinc powder and 35 parts of zinc powder;

[0087] The modified zinc powder is obtained by compound modification of zinc powder with a pyridine crown ether ring compound and an amino-silane coupling agent;

[0088] The silicate solution is obtained by compounding a lithium silicate solution and a potassium silicate solution with a weight ratio of 1:8; the modulus of the lithium silicate is 4.8, and the modulus of the potassium silicate is 6.5; by weight percentage, the solid content of the lithium silicate solution is 19%; by weight percentage, the solid content of the potassium silicate solution is 25%;

[0089] The auxiliary agent is composed of a thickening agent and an antifoaming agent with a weight ratio of 3:1;

[0090] The particle size of the zinc powder is 500 mesh;

[0091] The preparation method of the modified zinc powder comprises the following process:

[0092] Dissolve 2,2'-bipyridine-5,5'-dicarboxaldehyde in dichloromethane solvent, and then stir it in an ice-water bath for 15 minutes; then add trifluoromethanesulfonic acid dissolved in dichloromethane to the reaction system and stir for 4 hours. The molar ratio of 2,2'-bipyridine-5,5'-dicarboxaldehyde to trifluoromethanesulfonic acid is 0.47:1.2; after the reaction, filter to obtain a pale yellow solid, and recrystallize it in acetonitrile and diethyl ether to obtain 2H + -BPDA (white solid);

[0093] Add the 2H + -BPDA and dibenzo-24-crown-8 with a molar ratio of 1:1 to ethanol and stir at room temperature for 24 hours, then perform rotary evaporation to remove the solvent and dry to obtain the pyridine crown ether ring compound (yellow solid);

[0094] Add an amino silane coupling agent (specifically N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane) and zinc powder to absolute ethanol, stir at 55 °C for 1.5 hours, then add the pyridine crown ether ring compound and continue to stir at 55 °C for 1.5 hours, filter, wash and dry to obtain the modified zinc powder; wherein, the weight ratio of the pyridine crown ether ring compound, the amino silane coupling agent, the zinc powder and the absolute ethanol is 1:0.5:2.2:10.

[0095] The preparation method of the above inorganic zinc-rich coating is the same as that in Example 1.

[0096] Example 3

[0097] This example provides an inorganic zinc-rich coating, which includes component A and component B with a weight ratio of 1:2.3;

[0098] Calculated by weight, component A includes the following raw materials: 85 parts of silicate solution and 2 parts of auxiliary agent;

[0099] Calculated by weight, component B includes the following raw materials: 20 parts of modified zinc powder and 25 parts of zinc powder;

[0100] The modified zinc powder is obtained by compound modification of zinc powder with a pyridine crown ether ring compound and an amino silane coupling agent;

[0101] The silicate solution is obtained by compounding a lithium silicate solution and a potassium silicate solution with a weight ratio of 1:8; the modulus of the lithium silicate is 4.8, and the modulus of the potassium silicate is 6.5; calculated by weight percentage, the solid content of the lithium silicate solution is 24%; calculated by weight percentage, the solid content of the potassium silicate solution is 25%;

[0102] The auxiliary agent is composed of a thickener and an antifoaming agent with a weight ratio of 5:1;

[0103] The particle size of the zinc powder is 800 mesh;

[0104] The preparation method of the modified zinc powder includes the following process:

[0105] Dissolve 2,2'-bipyridine-5,5'-dicarboxaldehyde in dichloromethane solvent, and then stir in an ice-water bath for 15 minutes; then drop trifluoromethanesulfonic acid dissolved in dichloromethane into the reaction system and stir for 4 hours. The molar ratio of 2,2'-bipyridine-5,5'-dicarboxaldehyde to trifluoromethanesulfonic acid is 0.47:1.2; after the reaction, filter to obtain a pale yellow solid, and recrystallize in acetonitrile and ether to obtain 2H + -BPDA (white solid);

[0106] Mix the 2H + -BPDA and dibenzo-24-crown-8 with a molar ratio of 1:1 and add them to ethanol for stirring at room temperature for 24 hours, and then perform rotary evaporation to remove the solvent and drying to obtain the pyridine crown ether ring compound (yellow solid);

[0107] Add an amino silane coupling agent (specifically N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane) and zinc powder to absolute ethanol, stir at 55 °C for 1.5 hours, then add the pyridine crown ether ring compound and continue to stir at 55 °C for 1.5 hours, filter, wash and dry to obtain the modified zinc powder; wherein, the weight ratio of the pyridine crown ether ring compound, the amino silane coupling agent, the zinc powder and the absolute ethanol is 1.5:1:3:20.

[0108] The preparation method of the above inorganic zinc-rich coating is the same as that in Example 1.

[0109] Comparative Example 1

[0110] This example provides an inorganic zinc-rich coating and its preparation method. The difference from Example 1 is only that: the modulus of the lithium silicate is 8.0, and the modulus of the potassium silicate is 2.8; the remaining steps and parameters are the same.

[0111] Comparative Example 2

[0112] This example provides an inorganic zinc-rich coating and its preparation method. The difference from Example 1 is only that the modified zinc powder is obtained by compound-modifying zinc powder with a crown ether ring compound and an amino-silane coupling agent, and specifically includes the following process: Add the amino-silane coupling agent (specifically N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane) and zinc powder into absolute ethanol, stir at 55 °C for 1.5 hours, then add the dibenzo-24-crown-8 and continue to stir at 55 °C for 1.5 hours, filter, wash and dry to obtain the modified zinc powder; wherein, the weight ratio of the dibenzo-24-crown-8, the amino-silane coupling agent, the zinc powder and the absolute ethanol is 1.2:0.8:2.5:15; the remaining steps and parameters are the same.

[0113] Test example

[0114] According to the existing test methods and standards, this example conducts performance tests on the inorganic zinc-rich coatings obtained in the above Examples 1 to 3 and Comparative Examples 1 to 2, and the test results are shown in Table 1.

[0115] Table 1

[0116]

[0117] As can be seen from Table 1, compared with the comparative examples, the inorganic zinc-rich coating provided by the embodiments of the present invention has better anti-slip performance and higher adhesion, and the effect of Example 1 is the best. In addition, the inorganic zinc-rich coating obtained in the embodiments of the present invention is subjected to a salt spray resistance test, and the test results show that they are all ≥1000 h, meeting the anti-corrosion index requirements.

[0118] In summary, the embodiments of the present invention provide an inorganic zinc-rich coating, its preparation method and application. By using a silicate solution with an appropriate modulus as the base material, introducing specific modified zinc powder and zinc powder as anti-corrosion components at the same time, and assisting with additives to improve the construction performance and film-forming performance, the comprehensive performance such as the anti-slip performance and adhesion of the inorganic zinc-rich coating is significantly improved, and it is particularly suitable for the treatment of high-strength bolt connection surfaces of steel components such as bridges and prefabricated buildings. Its excellent performance can effectively protect the connection surface from corrosion and wear, provide lasting and stable protection for high-strength bolts, and thus improve the service life and safety of the connection surface.

[0119] The various embodiments of the present invention may exist in the form of a range; it should be understood that the description in the form of a range is only for convenience and brevity and should not be construed as a rigid limitation on the scope of the present invention; therefore, it should be considered that the description of the range has specifically disclosed all possible sub-ranges and the individual values within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and the individual numbers within the range, such as 1, 2, 3, 4, 5, and 6, and this applies regardless of the range. Additionally, whenever a numerical range is indicated herein, it means including any cited number (fraction or integer) within the indicated range.

[0120] The above are only specific embodiments of the present invention, enabling those skilled in the art to understand or implement the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the broadest scope consistent with the principles and novel features claimed herein.

Claims

1. An inorganic zinc-rich coating, characterized in that: The inorganic zinc-rich coating comprises component A and component B; the weight ratio of component A to component B is 1:(1.8-2.3); In parts by weight, the component A comprises the following raw materials: 80 parts of silicate solution and 1.5 parts of auxiliary agent; In parts by weight, the B component includes the following raw materials: 15 parts of modified zinc powder and 30 parts of zinc powder; The modified zinc powder is obtained by composite-modifying zinc powder with a pyridine crown ether ring compound and an aminosilane coupling agent; The silicate solution is obtained by compounding a lithium silicate solution and a potassium silicate solution, wherein the modulus of the lithium silicate is 3 to 5, and the modulus of the potassium silicate is 5 to 6.5; The preparation method of the modified zinc powder comprises the following process: 2,2'-Bipyridine-5,5'-dicarboxaldehyde was first stirred with trifluoromethanesulfonic acid, then filtered and recrystallized to obtain 2H + -BPDA; The 2H + -BPDA and dibenzo-24-crown-8 are stirred for a second time, and then the solvent is removed to obtain the pyridine crown ether ring compound; The aminosilane coupling agent and zinc powder are added to anhydrous ethanol for a third stirring, and then the pyridine crown ether ring compound is added for a fourth stirring, filtered, washed and dried to obtain the modified zinc powder.

2. The inorganic zinc-rich coating according to claim 1, characterized in that: The weight ratio of the lithium silicate solution to the potassium silicate solution is (1-2):(5-8); in terms of weight percentage, the solid content of the lithium silicate solution is 19-24%; in terms of weight percentage, the solid content of the potassium silicate solution is 24-26%.

3. The inorganic zinc-rich coating according to claim 1, characterized in that: The molar ratio of the 2,2'-bipyridine-5,5'-dicarboxaldehyde to the trifluoromethanesulfonic acid is (0.45-0.50): (1.1-1.3); the 2H + The molar ratio of -BPDA to the dibenzo-24-crown ether-8 is 1:1; the weight ratio of the pyridine crown ether ring compound, the aminosilane coupling agent, the zinc powder and the anhydrous ethanol is (1~1.5):(0.5~1):(2.2~3):(10~20).

4. The inorganic zinc-rich coating according to claim 3, characterized in that: The working condition parameters of the first stirring include: temperature of 0~5°C, stirring time of 3.5~5 hours; the working condition parameters of the second stirring include: temperature of room temperature, stirring time of 20~30 hours; the working condition parameters of the third stirring include: temperature of 50~60°C, stirring time of 1~2 hours; the working condition parameters of the fourth stirring include: temperature of 50~60°C, stirring time of 1~2 hours; the aminosilane coupling agent includes at least one of N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane and 3-aminopropyltrimethoxysilane.

5. The inorganic zinc-rich coating according to claim 1, characterized in that: The auxiliary agent is composed of a thickener and a defoamer in a weight ratio of (3-5):1; the particle size of the zinc powder is 500-800 meshes.

6. A method for preparing the inorganic zinc-rich coating according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: Stirring and mixing the raw materials in component A to obtain component A; The raw materials in component B are added to component A and stirred to obtain the inorganic zinc-rich coating.

7. Use of the inorganic zinc-rich coating according to any one of claims 1 to 6 in treating bolt connection surfaces.

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