Modified basalt flake, corrosion-resistant coating and preparation method thereof

Abstract

The invention discloses a modified basalt scale, a corrosion-resistant coating and a preparation method of the modified basalt scale, and the preparation method of the modified basalt scale comprises the following steps: pre-activation: cleaning the basalt scale to obtain the pre-activated basalt scale; primary modification: grafting the high-reaction-activity groups to the surfaces of the basalt flakes to obtain primary modified basalt flakes; and secondary modification: grafting a corrosion inhibitor on the surface of the primary modified basalt flake to obtain a secondary modified basalt flake. According to the preparation method, secondary modified basalt flakes are obtained through grafting of high-reaction-activity groups and secondary modification of the corrosion inhibitor, the secondary modified basalt flakes are applied to an organic coating, the durability, mechanical strength and chemical stability of the organic coating can be better improved, then a metal base material is effectively protected, the corrosion resistance is improved, and the service life of the metal base material is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of corrosion-resistant materials, and particularly relates to a modified basalt flake, a corrosion-resistant coating and a preparation method thereof. Background Art

[0002] Water heaters can provide a stable hot water supply, making life more comfortable and convenient; among them, the inner tank is the core component of the water heater, and its main function is to store and heat water. However, due to long-term contact with various chemical substances in water, the inner tank is prone to corrosion, and the corrosion of the inner tank will bring the following problems.

[0003] 1) Leakage risk: When the inner tank is severely corroded, water leakage may occur, resulting in water damage and electrical failures, and even triggering safety accidents; 2) Water quality pollution: Rust and other harmful substances generated by corrosion will mix into the water, affecting water quality safety and posing a threat to people's health; 3) Energy efficiency decline: Corrosion of the inner tank will reduce the thermal efficiency, increase energy consumption, and lead to an increase in operating costs; 4) Maintenance costs: Corrosion of the inner tank requires regular maintenance or replacement, increasing the economic burden on users.

[0004] To solve the problem of inner tank corrosion, common anti-corrosion measures include: using a stainless steel inner tank, installing a magnesium rod (anode rod), water quality treatment, coating with an organic coating, etc. Among them, coating with an organic coating is a widely used inner tank anti-corrosion method. A single organic coating is difficult to meet the anti-corrosion requirements in some highly corrosive environments. By adding anti-corrosion fillers (such as basalt flakes) to the organic coating, the durability, mechanical strength and chemical stability of the coating can be significantly improved, thereby effectively protecting the metal substrate, improving the anti-corrosion performance and extending its service life.

[0005] However, after adding basalt flakes, the improvement of the durability, mechanical strength and chemical stability of the organic coating is limited. How to further improve the anti-corrosion performance of the coating is the key point and difficulty in subsequent research and development. Summary of the Invention

[0006] Therefore, the technical problem to be solved by the present invention is to overcome the defect that the improvement of the anti-corrosion performance of the organic coating by basalt flakes in the prior art is limited, so as to provide a modified basalt flake, a corrosion-resistant coating and a preparation method thereof that can significantly improve the anti-corrosion performance of the organic coating.

[0007] A preparation method of a modified basalt flake includes:

[0008] Pre-activation: Cleaning the basalt flake to obtain pre-activated basalt flake;

[0009] Primary modification: Grafting high-reactivity groups onto the surface of the basalt flake to obtain primary-modified basalt flake;

[0010] Secondary modification: A corrosion inhibitor is grafted onto the surface of the once-modified basalt flakes to obtain the twice-modified basalt flakes.

[0011] The highly reactive groups include isocyanates, preferably methyl-2,4-diisocyanate or hexamethylene diisocyanate;

[0012] And / or, the corrosion inhibitor includes benzotriazole or triethanolamine phosphate.

[0013] The process of pre-activation includes: stirring the basalt flakes with ethanol, separating and drying them, and then stirring them with a hydrogen peroxide solution;

[0014] Preferably, the stirring time is 0.5 h to 1 h, and / or the concentration of the hydrogen peroxide solution is 10-20%.

[0015] The process of the first modification includes: mixing and dispersing basalt flakes with a solvent and a catalyst to obtain a first dispersion; dispersing a substance with highly reactive groups in a solvent to obtain a second dispersion, dropping the second dispersion into the first dispersion, and adjusting to the reaction temperature for reaction after dropping; after the reaction is completed, washing and drying to obtain the once-modified basalt flakes;

[0016] Preferably, the solvent is anhydrous xylene, and / or the catalyst is selected from DY-5350, DY-5508, DY-5115 or dibutyltin dilaurate, and / or the dropping rate of the second dispersion is 40-60 drops / min, and / or the reaction temperature is 60-80 °C, and / or the reaction time is 3-4 h, and / or the washing method is to wash 3-5 times with anhydrous xylene;

[0017] Preferably, the addition amount of the catalyst is 0.5%-1.5% of the substance with highly reactive groups, and the addition amount of the substance with highly reactive groups is 15%-25% of the mass of the basalt flakes.

[0018] The process of the second modification includes: weighing the once-modified basalt flakes and mixing and stirring them with a solvent to obtain a first mixture; weighing a catalyst and mixing and stirring it with a solvent to obtain a second mixture; weighing a corrosion inhibitor and mixing and stirring it with a solvent to obtain a third mixture; adding the second mixture to the first mixture to obtain a fourth mixture; dropping the third mixture into the fourth mixture, and adjusting to the reaction temperature for reaction after dropping; after the reaction is completed, washing and drying to obtain the twice-modified basalt flakes;

[0019] Preferably, the temperature when the third mixed liquid is added is 60 - 80°C, and / or the dropping rate is 40 - 60 drops / min, and / or the reaction temperature is 60 - 80°C, and / or the reaction time is 2 - 4 h. The washing method is to wash 3 - 5 times with anhydrous xylene, and / or the drying is carried out in a vacuum drying oven;

[0020] Preferably, in the step of obtaining the first mixed liquid, the treatment temperature is 40 - 60°C, and the stirring treatment time is 20 - 30 min; and / or the solvent in the first mixed liquid is xylene; and / or the solvent in the second mixed liquid includes ethanol and xylene with a mass ratio of 1:1; and / or the solvent in the third mixed liquid is ethanol;

[0021] Preferably, the addition amount of the catalyst is 20% - 30% of the mass of the primary modified basalt scales, and the addition amount of the corrosion inhibitor is 40% - 60% of the primary modified basalt scales.

[0022] A kind of modified basalt scales is prepared by the above preparation method.

[0023] A corrosion-resistant coating, the raw materials of which include the above-mentioned modified basalt scales.

[0024] The raw materials further include epoxy resin. In the raw materials, the mass ratio of the modified basalt scales to the epoxy resin is 5 - 30:100.

[0025] The corrosion-resistant coating includes 100 parts of epoxy resin, 5 - 30 parts of secondary modified basalt scales, 10 - 20 parts of diluent, 0.3 - 0.8 parts of defoamer, 30 - 50 parts of curing agent, and 3 - 5 parts of leveling agent.

[0026] The preparation method of the above-mentioned corrosion-resistant coating includes:

[0027] Preparation of the mixed liquid: Add the defoamer, leveling agent, and diluent to the epoxy resin, stir and mix, and let it stand to obtain the mixed liquid;

[0028] Preparation of the coating: Mix and stir the mixed liquid with the secondary modified basalt scales, and then mix and stir with the curing agent to obtain the coating;

[0029] Preparation of the coating: Spray the coating onto the metal substrate and cure to obtain the coating.

[0030] The technical solution of the present invention has the following advantages:

[0031] 1. A preparation method of modified basalt flakes provided by the present invention obtains secondary modified basalt flakes through grafting of highly reactive groups and secondary modification with corrosion inhibitors. When applied to an organic coating, it can better improve the durability, mechanical strength, and chemical stability of the organic coating, thereby effectively protecting the metal substrate, enhancing the corrosion resistance, and extending its service life. Specifically, highly reactive groups such as isocyanate groups are grafted onto the surface of basalt flakes. The highly reactive groups serve as "molecular bridges" for loading corrosion inhibitors on the surface of basalt flakes and form the basis for the next reaction. Then, using the highly reactive groups grafted on the surface of basalt flakes as chemical reaction sites, corrosion inhibitors such as benzotriazole are further grafted onto the surface of basalt flakes, thereby achieving the composite modification of basalt flakes and obtaining the final secondary modified basalt flakes. Through result verification, it is found that when the secondary modified basalt flakes are applied to an organic coating, compared with directly applying basalt flakes to the organic coating, its durability, mechanical strength, and chemical stability can be significantly improved, thereby significantly enhancing the corrosion resistance of the organic coating and extending its service life.

[0032] 2. The corrosion-resistant coating of the present invention is prepared by combining specific secondary modified basalt flakes with epoxy resin. In the organic coating formed on the surface of the metal substrate, after part of the secondary modified basalt flakes settle on the surface of the metal substrate, the corrosion inhibitor on its surface can react with the metal substrate to form a protective film, further slowing down the corrosion of the metal substrate and better preventing the metal substrate from rusting. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the following drawings are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0034] Figure 1 It is the process flow chart of Embodiment 1 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0035] The following embodiments are provided to better understand the present invention further. They are not limited to the best embodiments, and do not limit the content and protection scope of the present invention. Any product obtained by anyone under the inspiration of the present invention or by combining the features of the present invention with other prior art features that is the same or similar to the present invention falls within the protection scope of the present invention.

[0036] For those without specific experimental procedures or conditions noted in the examples, the operations or conditions of the conventional experimental procedures described in the literature in this field can be followed. For reagents or instruments without the manufacturer noted, they are all conventional reagent products that can be obtained through commercial purchase.

[0037] Example 1

[0038] A preparation method of modified basalt flakes, as Figure 1 shown, includes:

[0039] A. Pre-activation step: A certain amount of 150-mesh basalt flakes are stirred in ethanol for 0.8 h, then filtered by suction, separated, dried, and then stirred in 15% hydrogen peroxide solution for 0.8 h to remove surface dirt, achieving the pre-activation of basalt flakes.

[0040] B. First modification step: Take 50 g of the basalt flakes treated in step A in a three-necked flask, add 300 mL of anhydrous xylene and catalyst DY-5350, with the catalyst addition amount being 0.1 g, and ultrasonically disperse at room temperature for 10 min. Weigh 10 g of methyl-2,4-diisocyanate (TDI) and uniformly mix it in a beaker containing 100 mL of anhydrous xylene, ultrasonically disperse for 10 min, then transfer it to a constant-pressure dropping funnel, and under the conditions of high-speed dispersion and nitrogen protection, drop it into the three-necked flask at a speed of 60 drops / min. After dropping, adjust the temperature to 70 °C and react for 4 h. After the reaction is completed, filter the basalt flakes by suction and wash them 4 times with anhydrous xylene, and then dry them in a vacuum drying oven to obtain the first-modified basalt flakes BS-TDI.

[0041] C. Second modification step: Weigh 10 g of BS-TDI in a three-necked flask containing 200 mL of anhydrous xylene, and stir at 60 °C under nitrogen protection for 20 min. Weigh 2.5 g of catalyst benzoyl peroxide, put it into a beaker containing 100 mL of ethanol and xylene (1:1), and magnetically stir and disperse it until it is completely dissolved. Then add it to the three-necked beaker containing BS-TDI. Weigh 5 g of corrosion inhibitor benzotriazole in a beaker containing 100 mL of ethanol, magnetically stir to dissolve it, then transfer it to a constant-pressure dropping funnel, and at 60 °C under nitrogen protection, drop it into the three-necked flask at a dropping speed of 60 drops / min. After completion, adjust the temperature to 80 °C and react for 3 h. After the reaction is completed, filter the basalt flakes by suction and wash them 4 times with anhydrous xylene, and then dry them in a vacuum drying oven to obtain the second-modified basalt flakes BS-TDI-corrosion inhibitor composite material.

[0042] A corrosion-resistant coating, comprising 100 g of epoxy resin E-51, 5 g of secondary modified basalt flakes, 10 g of 1,4-butanediol diglycidyl ether diluent, 0.8 g of BYK-037 defoamer, 50 g of phenolic amine curing agent, and 3 g of BYK-302 leveling agent. The preparation process is as follows:

[0043] 1) Add the defoamer, leveling agent, and diluent to the epoxy resin, stir at a rate of 400 rpm for 10 minutes, and let it stand at room temperature in a vacuum drying oven for 12 h to obtain a mixed solution.

[0044] 2) Add the secondary modified basalt flakes to the mixed solution obtained in step 1, stir at a rate of 400 rpm for 10 minutes, mix it with the curing agent, and stir at a rate of 400 rpm for 10 minutes to prepare the coating. Spray the coating onto a metal substrate (low-carbon steel plate Q235) and let it cure naturally.

[0045] Example 2

[0046] A preparation method of modified basalt flakes, comprising:

[0047] A. Pre-activation step: Stir a certain amount of 150-mesh basalt flakes in ethanol for 0.8 h, then filter and separate them by suction, dry them, and stir them in a 15% hydrogen peroxide solution for 0.8 h to remove surface dirt, thereby realizing the pre-activation of the basalt flakes.

[0048] B. Primary modification step: Take 50 g of the basalt flakes treated in step A in a three-necked flask, add 300 mL of anhydrous xylene and 0.1 g of catalyst DY-5350, and ultrasonically disperse them at room temperature for 10 min. Weigh 10 g of methyl-2,4-diisocyanate (TDI), uniformly mix it in a beaker containing 100 mL of anhydrous xylene, ultrasonically disperse it for 10 min, then transfer it to a constant-pressure dropping funnel, and drop it into the three-necked flask at a speed of 60 drops / min under the conditions of high-speed dispersion and nitrogen protection. After dropping, adjust the temperature to 70 °C and react for 4 h. After the reaction is completed, filter the basalt flakes by suction, wash them 4 times with anhydrous xylene, and then dry them in a vacuum drying oven to obtain primary modified basalt flakes BS-TDI.

[0049] C. Secondary modification step: Weigh 10 g of BS-TDI into a three-necked flask containing 200 mL of anhydrous xylene, and stir for 20 min at 60 °C under nitrogen protection. Weigh 2.5 g of benzoyl peroxide as the catalyst, put it into a beaker containing 100 mL of ethanol and xylene (1:1), and stir magnetically to disperse and dissolve it completely. Then add it to the three-necked beaker containing BS-TDI. Weigh 5 g of benzotriazole as the corrosion inhibitor into a beaker containing 100 mL of ethanol, stir magnetically to dissolve it, then transfer it into a constant-pressure dropping funnel, and drop it into the three-necked flask at a dropping rate of 60 drops / min at 60 °C under nitrogen protection. After completion, adjust the temperature to 80 °C and react for 3 h. After the reaction is completed, filter the basalt flakes by suction and wash them 4 times with anhydrous xylene, and then dry them in a vacuum drying oven to obtain the secondary-modified basalt flake BS-TDI-corrosion inhibitor composite material.

[0050] A corrosion-resistant coating comprises 100 g of waterborne epoxy resin E-44, 30 g of secondary-modified basalt flakes, 20 g of 1,6-hexanediol diglycidyl ether diluent, 0.5 g of BYK-A530 defoamer, 30 g of polyamide curing agent, and 3 g of BYK-331 leveling agent. The preparation process is as follows:

[0051] 1) Add the defoamer, leveling agent, and diluent to the epoxy resin, stir at a rate of 400 rpm for 10 minutes, and leave it standing at room temperature in a vacuum drying oven for 12 h to obtain a mixed solution.

[0052] 2) Add the secondary-modified basalt flakes to the mixed solution obtained in step 1, stir at a rate of 400 rpm for 10 minutes, mix it with the curing agent, and stir at a rate of 400 rpm for 10 minutes to prepare a coating. Spray the coating onto a metal substrate (low-carbon steel plate Q235) and cure it naturally.

[0053] Example 3

[0054] A preparation method of modified basalt flakes includes:

[0055] A. Pre-activation step: Stir a certain amount of 150-mesh basalt flakes in ethanol for 0.8 h, then filter and separate them by suction, dry them, and then stir them in a 15% hydrogen peroxide solution for 0.8 h to remove surface dirt and achieve the pre-activation of basalt flakes.

[0056] B. Primary modification step: Take 50 g of the basalt scales processed in step A and place them in a three-necked flask. Add 300 mL of anhydrous xylene and catalyst DY-5350, with the catalyst addition amount being 0.1 g. Ultrasonically disperse for 10 min at room temperature. Weigh 10 g of methyl-2,4-diisocyanate (TDI) and uniformly mix it into a beaker containing 100 mL of anhydrous xylene. After ultrasonically dispersing for 10 min, transfer it to a constant-pressure dropping funnel. Under the conditions of high-speed dispersion and nitrogen protection, drop it into the three-necked flask at a rate of 60 drops / min. After dropping, adjust the temperature to 70 °C and react for 4 h. After the reaction is completed, filter the basalt scales by suction and wash them 4 times with anhydrous xylene, and then dry them in a vacuum drying oven to obtain the primary modified basalt scales BS-TDI.

[0057] C. Secondary modification step: Weigh 10 g of BS-TDI and place it in a three-necked flask containing 200 mL of anhydrous xylene. Stir for 20 min at 60 °C under nitrogen protection. Weigh 2.5 g of the catalyst benzoyl peroxide, put it into a beaker containing 100 mL of ethanol and xylene (1:1), and magnetically stir and disperse it until it is completely dissolved. Then add it to the three-necked flask containing BS-TDI. Weigh 5 g of the corrosion inhibitor benzotriazole and put it into a beaker containing 100 mL of ethanol, magnetically stir to dissolve it, and then transfer it to a constant-pressure dropping funnel. At 60 °C under nitrogen protection, drop it into the three-necked flask at a dropping rate of 60 drops / min. After completion, adjust the temperature to 80 °C and react for 3 h. After the reaction is completed, filter the basalt scales by suction and wash them 4 times with anhydrous xylene, and then dry them in a vacuum drying oven to obtain the secondary modified basalt scale BS-TDI-corrosion inhibitor composite material.

[0058] A corrosion-resistant coating includes 100 g of bisphenol F epoxy resin, 15 g of secondary modified basalt scales, 15 g of benzyl glycidyl ether diluent, 0.3 g of BYK-012 defoamer, 40 g of phenolic amine curing agent, and 5 g of BYK-358 leveling agent. Its preparation process is as follows:

[0059] 1) Add the defoamer, leveling agent, and diluent to the epoxy resin, stir at a rate of 400 rpm for 10 minutes, and leave it standing at room temperature in a vacuum drying oven for 12 h to obtain a mixed solution.

[0060] 2) Add the secondary modified basalt scales to the mixed solution obtained in step 1, stir at a rate of 400 rpm for 10 minutes, mix the curing agent with it, and stir at a rate of 400 rpm for 10 minutes to prepare the coating. Spray the coating onto a metal substrate (low-carbon steel plate Q235) and let it cure naturally.

[0061] Example 4

[0062] A preparation method of modified basalt scales includes:

[0063] A. Pre-activation step: A certain amount of basalt scales with a mesh size of 150 are stirred in ethanol for 0.5 h, then filtered by suction, separated and dried. After that, they are stirred in a 10% hydrogen peroxide solution for 0.5 h to remove surface dirt, thus achieving the pre-activation of basalt scales.

[0064] B. First modification step: Take 50 g of the basalt scales treated in step A and put them into a three-necked flask. Add 300 mL of anhydrous xylene and catalyst DY-5508, with the catalyst addition amount being 0.05 g. Ultrasonically disperse for 10 min at room temperature. Weigh 7.5 g of methyl-2,4-diisocyanate (TDI) and uniformly mix it into a beaker containing 100 mL of anhydrous xylene. After ultrasonic dispersion for 10 min, transfer it into a constant-pressure dropping funnel. Under the conditions of high-speed dispersion and nitrogen protection, drop it into the three-necked flask at a rate of 50 drops / min. After dropping, adjust the temperature to 60 °C and react for 4 h. After the reaction is completed, filter the basalt scales by suction and wash them 5 times with anhydrous xylene. Then dry them in a vacuum drying oven to obtain the first-modified basalt scales BS-TDI.

[0065] C. Second modification step: Weigh 10 g of BS-TDI and put it into a three-necked flask containing 200 mL of anhydrous xylene. Stir for 30 min at 40 °C under nitrogen protection. Weigh 3 g of catalyst benzoyl peroxide, put it into a beaker containing 100 mL of ethanol and xylene (1:1), and magnetically stir and disperse it until it is completely dissolved. Then add it to the three-necked beaker containing BS-TDI. Weigh 6 g of corrosion inhibitor benzotriazole, put it into a beaker containing 100 mL of ethanol, magnetically stir to dissolve it, and then transfer it into a constant-pressure dropping funnel. At 70 °C and under nitrogen protection, drop it into the three-necked flask at a dropping rate of 50 drops / min. After completion, adjust the temperature to 60 °C and react for 4 h. After the reaction is completed, filter the basalt scales by suction and wash them 5 times with anhydrous xylene. Then dry them in a vacuum drying oven to obtain the second-modified basalt scales BS-TDI-corrosion inhibitor composite material.

[0066] A corrosion-resistant coating comprises 100 g of epoxy resin E-51, 5 g of second-modified basalt scales, 10 g of 1,4-butanediol diglycidyl ether diluent, 0.8 g of BYK-037 defoamer, 50 g of phenolic amine curing agent, and 3 g of BYK-302 leveling agent. The preparation process is as follows:

[0067] 1) Add the defoamer, leveling agent, and diluent to the epoxy resin, stir at a rate of 400 rpm for 10 minutes, and leave it standing at room temperature in a vacuum drying oven for 12 h to obtain a mixed solution.

[0068] 2) Add secondary modified basalt flakes to the mixed solution obtained in step 1, stir at a rate of 400 rpm for 10 minutes, mix with a curing agent, stir at a rate of 400 rpm for 10 minutes to prepare a coating, and spray the coating onto a metal substrate (low-carbon steel plate Q235) for natural curing.

[0069] Example 5

[0070] A preparation method of modified basalt flakes, comprising:

[0071] A. Pre-activation step: Stir a certain amount of 150-mesh basalt flakes in ethanol for 1 h, then filter by suction, separate and dry, and then stir in a 20% hydrogen peroxide solution for 1 h to remove surface dirt, thereby realizing the pre-activation of basalt flakes.

[0072] B. Primary modification step: Take 50 g of the basalt flakes treated in step A in a three-necked flask, add 300 mL of anhydrous xylene and the catalyst dibutyltin dilaurate, with the catalyst addition amount being 0.15 g, and ultrasonically disperse at room temperature for 10 min. Weigh 12.5 g of methyl-2,4-diisocyanate (TDI), uniformly mix it in a beaker containing 100 mL of anhydrous xylene, ultrasonically disperse for 10 min, then transfer it to a constant-pressure dropping funnel, and under the conditions of high-speed dispersion and nitrogen protection, drop it into the three-necked flask at a rate of 40 drops / min. After dropping, adjust the temperature to 80 °C and react for 3 h. After the reaction is completed, filter the basalt flakes by suction and wash them 3 times with anhydrous xylene, and then dry them in a vacuum drying oven to obtain primary modified basalt flakes BS-TDI.

[0073] C. Secondary modification step: Weigh 10 g of BS-TDI in a three-necked flask containing 200 mL of anhydrous xylene, and stir at 50 °C under nitrogen protection for 25 min. Weigh 2 g of the catalyst benzoyl peroxide, put it in a beaker containing 100 mL of ethanol and xylene (1:1), stir magnetically to disperse it until it is completely dissolved. Then add it to the three-necked beaker containing BS-TDI. Weigh 4 g of the corrosion inhibitor benzotriazole in a beaker containing 100 mL of ethanol, stir magnetically to dissolve it, and then transfer it to a constant-pressure dropping funnel. At 80 °C and under nitrogen protection, drop it into the three-necked flask at a dropping rate of 40 drops / min. After completion, adjust the temperature to 70 °C and react for 2 h. After the reaction is completed, filter the basalt flakes by suction and wash them 3 times with anhydrous xylene, and then dry them in a vacuum drying oven to obtain secondary modified basalt flake BS-TDI-corrosion inhibitor composite material.

[0074] A corrosion-resistant coating, comprising 100 g of epoxy resin E-51, 5 g of secondary modified basalt flakes, 10 g of 1,4-butanediol diglycidyl ether diluent, 0.8 g of BYK-037 defoamer, 50 g of phenolic amine curing agent, and 3 g of BYK-302 leveling agent. The preparation process is as follows:

[0075] 1) Add the defoamer, leveling agent, and diluent to the epoxy resin, stir at a rate of 400 rpm for 10 minutes, and let it stand at room temperature in a vacuum drying oven for 12 h to obtain a mixed solution.

[0076] 2) Add the secondary modified basalt flakes to the mixed solution obtained in step 1, stir at a rate of 400 rpm for 10 minutes, mix it with the curing agent, and stir at a rate of 400 rpm for 10 minutes to prepare the coating. Spray the coating onto a metal substrate (low-carbon steel plate Q235) and let it cure naturally.

[0077] Example 6

[0078] A preparation method of modified basalt flakes, comprising:

[0079] A. Pre-activation step: Stir a certain amount of 150-mesh basalt flakes in ethanol for 0.8 h, then filter and separate them by suction, dry them, and stir them in a 15% hydrogen peroxide solution for 0.8 h to remove surface dirt, thereby achieving the pre-activation of the basalt flakes.

[0080] B. Primary modification step: Take 50 g of the basalt flakes treated in step A in a three-necked flask, add 300 mL of anhydrous xylene and 0.1 g of catalyst DY-5350, and ultrasonically disperse them at room temperature for 10 min. Weigh 10 g of hexamethylene diisocyanate (HDI), uniformly mix it in a beaker containing 100 mL of anhydrous xylene, ultrasonically disperse it for 10 min, then transfer it to a constant-pressure dropping funnel, and drop it into the three-necked flask at a speed of 60 drops / min under the conditions of high-speed dispersion and nitrogen protection. After dropping, adjust the temperature to 70 °C and react for 4 h. After the reaction is completed, filter the basalt flakes by suction, wash them 4 times with anhydrous xylene, and then dry them in a vacuum drying oven to obtain the primary modified basalt flakes BS-HDI.

[0081] C. Secondary modification step: Weigh 10 g of BS-HDI into a three-necked flask containing 200 mL of anhydrous xylene, and stir for 20 min at 60 °C under nitrogen protection. Weigh 2.5 g of benzoyl peroxide as the catalyst, put it into a beaker containing 100 mL of ethanol and xylene (1:1), and stir magnetically to disperse and completely dissolve it. Then add it to the three-necked beaker containing BS-HDI. Weigh 5 g of benzotriazole as the corrosion inhibitor into a beaker containing 100 mL of ethanol, stir magnetically to dissolve it, then transfer it into a constant-pressure dropping funnel, and drop it into the three-necked flask at a dropping rate of 60 drops / min at 60 °C under nitrogen protection. After completion, adjust the temperature to 80 °C and react for 3 h. After the reaction is completed, filter the basalt flakes by suction and wash them 4 times with anhydrous xylene, and then dry them in a vacuum drying oven to obtain the secondary-modified basalt flake BS-HDI-corrosion inhibitor composite material.

[0082] A corrosion-resistant coating includes 100 g of epoxy resin E-51, 5 g of secondary-modified basalt flakes, 10 g of 1,4-butanediol diglycidyl ether diluent, 0.8 g of BYK-037 defoamer, 50 g of phenolic amine curing agent, and 3 g of BYK-302 leveling agent. The preparation process is as follows:

[0083] 1) Add the defoamer, leveling agent, and diluent to the epoxy resin, stir at a rate of 400 rpm for 10 minutes, and let it stand at room temperature in a vacuum drying oven for 12 h to obtain a mixed solution.

[0084] 2) Add the secondary-modified basalt flakes to the mixed solution obtained in step 1, stir at a rate of 400 rpm for 10 minutes, mix the curing agent with it, and stir at a rate of 400 rpm for 10 minutes to prepare the coating. Spray the coating onto a metal substrate (low-carbon steel plate Q235) and let it cure naturally.

[0085] Example 7

[0086] A preparation method of modified basalt flakes includes:

[0087] A. Pre-activation step: Stir a certain amount of 150-mesh basalt flakes in ethanol for 0.8 h, then filter and separate them by suction, dry them, and then stir them in a 15% hydrogen peroxide solution for 0.8 h to remove surface dirt and achieve the pre-activation of the basalt flakes.

[0088] B. Primary modification step: Take 50 g of the basalt scales treated in step A and place them in a three-necked flask. Add 300 mL of anhydrous xylene and catalyst DY-5350, with the catalyst addition amount being 0.1 g. Ultrasonically disperse for 10 min at room temperature. Weigh 10 g of methyl-2,4-diisocyanate (TDI) and uniformly mix it into a beaker containing 100 mL of anhydrous xylene. After ultrasonically dispersing for 10 min, transfer it to a constant-pressure dropping funnel. Under the conditions of high-speed dispersion and nitrogen protection, drop it into the three-necked flask at a rate of 60 drops / min. After dropping, adjust the temperature to 70 °C and react for 4 h. After the reaction is completed, filter the basalt scales by suction and wash them 4 times with anhydrous xylene, and then dry them in a vacuum drying oven to obtain the primary modified basalt scales BS-TDI.

[0089] C. Secondary modification step: Weigh 10 g of BS-TDI and place it in a three-necked flask containing 200 mL of anhydrous xylene. Stir at 60 °C under nitrogen protection for 20 min. Weigh 2.5 g of the catalyst benzoyl peroxide, put it into a beaker containing 100 mL of ethanol and xylene (1:1), and stir magnetically to disperse it until it is completely dissolved. Then add it to the three-necked beaker containing BS-TDI. Weigh 5 g of the corrosion inhibitor triethanolamine phosphate and put it into a beaker containing 100 mL of ethanol. Stir magnetically to dissolve it, and then transfer it to a constant-pressure dropping funnel. At 60 °C under nitrogen protection, drop it into the three-necked flask at a dropping rate of 60 drops / min. After completion, adjust the temperature to 80 °C and react for 3 h. After the reaction is completed, filter the basalt scales by suction and wash them 4 times with anhydrous xylene, and then dry them in a vacuum drying oven to obtain the secondary modified basalt scale BS-TDI-corrosion inhibitor composite material.

[0090] A corrosion-resistant coating includes 100 g of epoxy resin E-51, 5 g of secondary modified basalt scales, 10 g of 1,4-butanediol diglycidyl ether diluent, 0.8 g of BYK-037 defoamer, 50 g of phenolic amine curing agent, and 3 g of BYK-302 leveling agent. Its preparation process is as follows:

[0091] 1) Add the defoamer, leveling agent, and diluent to the epoxy resin, stir at a rate of 400 rpm for 10 minutes, and let it stand at room temperature in a vacuum drying oven for 12 h to obtain a mixed solution.

[0092] 2) Add the secondary modified basalt scales to the mixed solution obtained in step 1, stir at a rate of 400 rpm for 10 minutes, mix it with the curing agent, and stir at a rate of 400 rpm for 10 minutes to prepare the coating. Spray the coating onto a metal substrate (low-carbon steel plate Q235) and let it cure naturally.

[0093] Comparative Example 1

[0094] A corrosion-resistant coating, comprising 100 g of epoxy resin E-51, 5 g of basalt scales, 10 g of 1,4-butanediol diglycidyl ether diluent, 0.8 g of BYK-037 defoamer, 50 g of phenolic amine curing agent, and 3 g of BYK-302 leveling agent. The preparation process is as follows:

[0095] 1) Add the defoamer, leveling agent, and diluent to the epoxy resin, stir at a rate of 400 rpm for 10 minutes, and let it stand at room temperature in a vacuum drying oven for 12 h to obtain a mixed solution.

[0096] 2) Add the secondarily modified basalt scales to the mixed solution obtained in step 1, stir at a rate of 400 rpm for 10 minutes, mix the curing agent with it, and stir at a rate of 400 rpm for 10 minutes to prepare the coating. Spray the coating onto a metal substrate (low-carbon steel plate Q235) and let it cure naturally.

[0097] Among them, the basalt scales are the pre-activated basalt scales in Example 1. The specific process is as follows: Stir a certain amount of 150-mesh basalt scales in ethanol for 0.8 h, then filter and separate them by suction and dry them. Then stir them in a 15% hydrogen peroxide solution for 0.8 h to remove surface dirt, thereby achieving the pre-activation of the basalt scales.

[0098] Comparative Example 2

[0099] A corrosion-resistant coating, comprising 100 g of waterborne epoxy resin E-44, 30 g of basalt scales, 20 g of 1,6-hexanediol diglycidyl ether diluent, 0.5 g of BYK-A530 defoamer, 30 g of polyamide curing agent, and 3 g of BYK-331 leveling agent. The preparation process is as follows:

[0100] 1) Add the defoamer, leveling agent, and diluent to the epoxy resin, stir at a rate of 400 rpm for 10 minutes, and let it stand at room temperature in a vacuum drying oven for 12 h to obtain a mixed solution.

[0101] 2) Add the secondarily modified basalt scales to the mixed solution obtained in step 1, stir at a rate of 400 rpm for 10 minutes, mix the curing agent with it, and stir at a rate of 400 rpm for 10 minutes to prepare the coating. Spray the coating onto a metal substrate (low-carbon steel plate Q235) and let it cure naturally.

[0102] Among them, the basalt scales are the pre-activated basalt scales in Example 2. The specific process is as follows: Stir a certain amount of 150-mesh basalt scales in ethanol for 0.8 h, then filter and separate them by suction and dry them. Then stir them in a 15% hydrogen peroxide solution for 0.8 h to remove surface dirt, thereby achieving the pre-activation of the basalt scales.

[0103] Comparative Example 3

[0104] A corrosion-resistant coating, comprising 100 g of bisphenol F epoxy resin, 15 g of basalt scales, 15 g of benzyl glycidyl ether diluent, 0.3 g of BYK-012 defoamer, 40 g of phenolic amine curing agent, and 5 g of BYK-358 leveling agent. The preparation process is as follows:

[0105] 1) Add the defoamer, leveling agent, and diluent to the epoxy resin, stir at a rate of 400 rpm for 10 minutes, and leave it standing at room temperature in a vacuum drying oven for 12 h to obtain a mixed solution.

[0106] 2) Add the secondary-modified basalt scales to the mixed solution obtained in step 1, stir at a rate of 400 rpm for 10 minutes, mix it with the curing agent, and stir at a rate of 400 rpm for 10 minutes to prepare the coating. Spray the coating onto a metal substrate (low-carbon steel plate Q235) and cure it naturally.

[0107] Among them, the basalt scales are the pre-activated basalt scales in Example 3. The specific process is as follows: Stir a certain amount of 150-mesh basalt scales in ethanol for 0.8 h, then filter and separate them by suction and dry them. Then stir them in a 15% hydrogen peroxide solution for 0.8 h to remove surface dirt, realizing the pre-activation of the basalt scales.

[0108] Perform performance tests on the coatings prepared in the examples and comparative examples, such as film appearance, coating hardness, coating adhesion, and salt spray resistance. The specific test methods for each test are as follows:

[0109] Film appearance: Tested with reference to GB / T 1721-2008;

[0110] Coating hardness: Tested with reference to GB / T 6739-2006;

[0111] Coating adhesion: Tested with reference to GB / T 9286-1998;

[0112] Salt spray resistance: Tested with reference to GB / T 1771-2007.

[0113] The test results of each example and comparative example are shown in Table 1 below.

[0114] Table 1

[0115]

[0116] The data of the above Examples 4-7 are basically equivalent to the data of Example 1.

[0117] In summary, it can be seen that highly reactive groups such as isocyanate groups are grafted onto the surface of basalt scales, and these highly reactive groups serve as the "molecular bridges" for loading corrosion inhibitors on the surface of basalt scales, which is the basis for the next step of the reaction. Then, using the highly reactive groups grafted on the surface of basalt scales as chemical reaction sites, corrosion inhibitors such as benzotriazole are further grafted onto the surface of basalt scales, thereby realizing the composite modification of basalt scales and obtaining the final doubly modified basalt scales. Through result verification, it is found that when the doubly modified basalt scales are applied to an organic coating, compared with directly applying basalt scales to the organic coating, its durability, mechanical strength, and chemical stability can be significantly improved, thereby significantly enhancing the corrosion resistance of the organic coating and extending its service life.

[0118] Obviously, the above embodiments are merely examples for clear illustration and not limitations on the implementation manners. For those of ordinary skill in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to enumerate all the implementation manners here. And the obvious changes or modifications derived therefrom still fall within the protection scope of the present invention.

Claims

1. A method for preparing modified basalt flakes, characterized in that: include: Pre-activation: cleaning the basalt flakes to obtain pre-activated basalt flakes; Primary modification: grafting highly reactive groups onto the surface of basalt flakes to obtain primary modified basalt flakes; Secondary modification: Corrosion inhibitor is grafted onto the surface of primary modified basalt flakes to obtain secondary modified basalt flakes.

2. The preparation method according to claim 1, characterized in that: The highly reactive groups include isocyanates, preferably methyl-2,4-diisocyanate or hexamethylene diisocyanate; And / or, the corrosion inhibitor includes benzotriazole or triethanolamine phosphate.

3. The preparation method according to claim 1 or 2, characterized in that: The pre-activation process includes: stirring the basalt flakes with ethanol, separating and drying, and then stirring with a hydrogen peroxide solution; Preferably, the stirring treatment time is 0.5 h to 1 h, and / or the concentration of the hydrogen peroxide solution is 10-20%.

4. The preparation method according to claim 1 or 2, characterized in that: The primary modification process includes: mixing and dispersing basalt flakes with a solvent and a catalyst to obtain a first dispersion; dispersing a substance with a highly reactive group with a solvent to obtain a second dispersion; dripping the second dispersion into the first dispersion, and adjusting the temperature to a reaction temperature for reaction after dripping; washing and drying after the reaction is completed to obtain a primary modified basalt flake; Preferably, the solvent is anhydrous xylene, and / or the catalyst is selected from DY-5350, DY-5508, DY-5115 or dibutyltin dilaurate, and / or the dripping speed of the second dispersion is 40-60 drops / min, and / or the reaction temperature is 60-80° C., and / or the reaction time is 3-4 hours, and / or the washing method is washing 3 to 5 times with anhydrous xylene; Preferably, the amount of the catalyst added is 0.5%-1.5% of the substance with high reactive groups, and the amount of the substance with high reactive groups added is 15%-25% of the mass of the basalt flakes.

5. The preparation method according to claim 1 or 2, characterized in that: The secondary modification process comprises: weighing the primary modified basalt flakes and mixing with a solvent to obtain a first mixed solution; weighing the catalyst and mixing with a solvent to obtain a second mixed solution; weighing the corrosion inhibitor and mixing with a solvent to obtain a third mixed solution; adding the second mixed solution to the first mixed solution to obtain a fourth mixed solution; dripping the third mixed solution into the fourth mixed solution, and adjusting the temperature to react after dripping; washing and drying after the reaction is completed to obtain the secondary modified basalt flakes; Preferably, the temperature of the third mixed solution when added dropwise is 60-80°C, and / or the dropping speed is 40-60 drops / min, and / or the reaction temperature is 60-80°C, and / or the reaction time is 2-4h, the washing method is washing with anhydrous xylene for 3 to 5 times, and / or the drying is carried out in a vacuum drying oven; Preferably, in the step of obtaining the first mixed solution, the treatment temperature is 40-60°C and the stirring treatment time is 20-30min; and / or, the solvent in the first mixed solution is xylene; and / or, the solvent in the second mixed solution includes ethanol and xylene in a mass ratio of 1:1; and / or, the solvent in the third mixed solution is ethanol; Preferably, the amount of the catalyst added is 20%-30% of the mass of the primary modified basalt flakes, and the amount of the corrosion inhibitor added is 40%-60% of the mass of the primary modified basalt flakes.

6. A modified basalt flake, characterized in that: The preparation method is described in any one of claims 1 to 5.

7. A corrosion-resistant coating, characterized in that: The raw material comprises the modified basalt flakes of claim 6.

8. The corrosion-resistant coating according to claim 7, characterized in that: The raw materials also include epoxy resin, and in the raw materials, the mass ratio of modified basalt flakes to epoxy resin is 5-30:

100.

9. The corrosion-resistant coating according to claim 8, characterized in that: It includes 100 parts of epoxy resin, 5-30 parts of secondary modified basalt flakes, 10-20 parts of diluent, 0.3-0.8 parts of defoaming agent, 30-50 parts of curing agent and 3-5 parts of leveling agent.

10. The method for preparing the corrosion-resistant coating according to claim 9, characterized in that: include: Preparation of mixed solution: adding defoamer, leveling agent and diluent into epoxy resin, stirring and mixing, and standing to obtain mixed solution; Preparation of coating: mixing the mixed liquid with the secondary modified basalt flakes, and then mixing with the curing agent to obtain the coating; Preparation of coating: The coating is sprayed onto the metal substrate and the coating is obtained after curing.

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