Composite microwave-absorbing and anticorrosion material with carbonyl iron as core, preparation method and application thereof in corrosion-resistant microwave-absorbing coating

Abstract

The present invention provides a composite absorbing and anti-corrosion material with carbonyl iron as a core body, a preparation method and its application in a corrosion-resistant absorbing coating, belonging to the technical field of absorbing and anti-corrosion materials. The material comprises: carbonyl iron particles, which are core bodies; a mesoporous SiO2 layer, which is coated on the surface of the carbonyl iron particles to form a shell; and a corrosion inhibitor loaded in the mesoporous SiO2 layer; the corrosion inhibitor is an imidazole ammonium salt corrosion inhibitor or a benzoheterocyclic corrosion inhibitor. The composite absorbing and anti-corrosion material of the present invention has excellent absorbing performance, and can also provide anti-oxidation and anti-corrosion effects, so as to delay or prevent coating aging or metal substrate corrosion, realize long-term anti-corrosion protection function, and improve its adaptability and service life in harsh marine environments; its preparation method is simple in process and highly operable, and the obtained composite absorbing and anti-corrosion material has good dispersibility, is not prone to particle agglomeration, and has the potential for large-scale mass production.

Description

Technical Field

[0001] The present invention relates to the technical field of microwave absorbing and anti-corrosion materials, and in particular to a composite microwave absorbing and anti-corrosion material with carbonyl iron as a core, a preparation method and application thereof in corrosion-resistant microwave absorbing coatings. Background Art

[0002] With the rapid development of information technology and the popularization of 5G communication technology, electronic products are widely used, and the resulting electromagnetic radiation and electromagnetic pollution are becoming increasingly severe. At the same time, in the field of national defense, the further improvement of radar technology has put forward higher requirements for electromagnetic stealth materials. Therefore, the research and development of advanced absorbing materials has become a research hotspot for many scientific researchers. Absorbing materials refer to a type of material that can absorb and attenuate the energy of incident electromagnetic waves, and convert its electromagnetic energy into heat energy to dissipate or make the electromagnetic waves disappear due to interference. They have important applications in electromagnetic radiation protection and military stealth.

[0003] However, in the actual service of absorbing materials, adverse conditions in the environment will cause the absorbing performance to weaken. For example, the actual application effect of absorbing materials in the marine environment where ships are in service is poor. The absorbing coating on the surface of the ship is exposed to harsh marine environments such as high heat, high humidity, high salt fog, strong light, and high ultraviolet rays for a long time, as well as the influence of various factors such as sea fog, tides, and seawater splash. The surface of the ship is very prone to corrosion. Corrosion will gradually change the morphology and structure of the absorbing material in the absorbing coating. Various corrosion factors gradually spread through coating defects, causing the electromagnetic wave absorption performance of the coating to decay until it is completely lost, and the service life is greatly shortened compared to other application environments. Therefore, in order to better maintain the stability of the absorbing performance, materials with excellent anti-corrosion and absorbing dual properties have become the focus of research and development.

[0004] Carbonyl iron powder (CIP) is a common magnetic metal absorbing material. It has the advantages of high saturation magnetization, high Curie temperature, low cost, etc. It also has good absorbing performance and can effectively absorb electromagnetic waves, especially in the high-frequency band. It is a very potential absorbing material. However, its own high electrical conductivity leads to poor absorbing performance, poor oxidation resistance and corrosion resistance. When used in hot and humid and marine environments, absorbing coatings prepared with carbonyl iron as absorbing material are prone to electrochemical corrosion problems such as oxygen absorption corrosion, causing aging and failure of the absorbing coating, thus limiting the application of carbonyl iron. Summary of the invention

[0005] 1. Technical issues to be resolved

[0006] The present invention provides a composite absorbing and anti-corrosion material with carbonyl iron as a core, a preparation method and application thereof in a corrosion-resistant absorbing coating, so as to solve the problems that the existing carbonyl iron has poor absorbing performance, poor oxidation resistance and corrosion resistance, and is prone to electrochemical corrosion and coating aging failure.

[0007] (II) Technical solution

[0008] To achieve the above object, the present invention provides a composite wave absorbing and anti-corrosion material with carbonyl iron as the core, comprising: carbonyl iron particles, the carbonyl iron particles as the core; mesoporous SiO 2 Layer, mesoporous SiO 2 The layer is coated on the surface of the carbonyl iron particles to form a shell; and the 2 The corrosion inhibitor in the layer; the particle size of the carbonyl iron particles is 1-20 μm; the corrosion inhibitor is an imidazole ammonium salt corrosion inhibitor or a benzoheterocyclic corrosion inhibitor.

[0009] Compared with conventional carbonyl iron particles, the composite wave absorbing and anti-corrosion material of the present invention has enhanced wave absorbing performance and also has anti-oxidation and anti-corrosion capabilities. When the composite wave absorbing and anti-corrosion material is exposed to corrosive media, the mesoporous SiO 2 The coating and the corrosion inhibitor therein can provide anti-corrosion effect, block the penetration of corrosive media, inhibit and delay the spread of corrosion, thereby delaying or preventing coating aging or corrosion of the metal substrate, and improving its adaptability and service life in harsh marine environments.

[0010] According to the present invention, the corrosion inhibitor is an imidazole ammonium salt corrosion inhibitor, and its chemical structure is shown in formula (I):

[0011]

[0012] The corrosion inhibitor of the above formula (I) is 1-hexadecyl-3-(3-(3-propylureido)propyl)imidazolium bromide, also known as corrosion inhibitor M16.

[0013] According to the present invention, the corrosion inhibitor is a benzoheterocyclic corrosion inhibitor, and its chemical structure is shown in formula (II):

[0014] Wherein, R is a C16 alkyl group.

[0015] The corrosion inhibitor of the above formula (II) is a derivative of benzotriazole, referred to as BTA-16-BTA.

[0016] The present invention also provides a method for preparing a composite wave absorbing and anti-corrosion material with carbonyl iron as a core, comprising: coating the surface of carbonyl iron particles with mesoporous SiO 2 layer, and obtain CIP@SiO 2 particles; and, using vacuum impregnation method in CIP@SiO2 The corrosion inhibitor is adsorbed and loaded on the particle surface to obtain powdered CIP@SiO 2 - Corrosion inhibitor material, that is, a composite wave absorbing and anti-corrosion material with carbonyl iron as the core; the corrosion inhibitor is an imidazole ammonium salt corrosion inhibitor or a benzoheterocyclic corrosion inhibitor; the chemical structure of the imidazole ammonium salt corrosion inhibitor is shown in formula (I):

[0017]

[0018] The chemical structure of benzoheterocyclic corrosion inhibitor is shown in formula (II):

[0019] Wherein, R is a C16 alkyl group.

[0020] Using CIP as the matrix, SiO 2 The corrosion inhibitor was loaded on the CIP surface in two steps to synthesize the core-shell structure of CIP@SiO 2 -Corrosion inhibitor material, shell SiO 2 The conductive paths between CIPs are avoided, and the impedance matching is further optimized, thereby enhancing the wave absorption performance of CIPs, and also improving the anti-corrosion and anti-oxidation capabilities of CIPs. The preparation method is simple in process and highly operable. The prepared composite wave absorbing and anti-corrosion material has good dispersibility and is not prone to particle agglomeration, thus having the potential for large-scale mass production.

[0021] According to the present invention, CIP@SiO 2 The particle preparation steps are as follows: CIP particles are dispersed in a mixed solution of ethanol and deionized water, and then ammonia water is added to adjust the pH to 10, and then tetraethyl orthosilicate is added dropwise to the obtained mixed system under stirring conditions, and the tetraethyl orthosilicate in the mixed system is hydrolyzed at room temperature to obtain CIP@SiO 2 Particles. Ethyl orthosilicate contains abundant silicon-oxygen bonds, which can generate SiO 2 , providing sufficient silicon source for the subsequent coating process, and forming a uniform and dense coating layer on the surface of CIP particles under stirring. 2 The layer is coated on the surface of CIP particles, which enhances the wave absorption, corrosion resistance and oxidation resistance of CIP and can effectively protect CIP. 2 The rich hydroxyl groups on the surface of the layer are also beneficial to the subsequent adsorption and loading of corrosion inhibitors.

[0022] According to the present invention, in the mixed solution of ethanol and deionized water, the mass ratio of ethanol to water is (14-16):1; the added amount of CIP particles is 90-150g, and the added amount of tetraethyl orthosilicate is 40-50mL; the stirring speed is 350-500r / min, the dropping speed is 0.05-0.10mL / s, and the hydrolysis time is 4-6h.

[0023] According to the present invention, the steps of the vacuum impregnation method are as follows: CIP@SiO 2 The particles were added to an ethanol solution containing a corrosion inhibitor, dispersed evenly by ultrasonication, and then the dispersion system was evacuated. The obtained solid was washed with ethanol for 1-3 times, and finally dried in vacuum at 55-65°C for 24 hours to form a powdered CIP@SiO 2 -Corrosion inhibitor material. The corrosion inhibitor is adsorbed on SiO by vacuuming 2 In the mesopores of the layer, the unabsorbed corrosion inhibitor is removed by ethanol cleaning. The loaded corrosion inhibitor improves the compactness of the shell, forms a coordination interaction with the CIP surface, enhances the corrosion resistance, and protects the CIP substrate, isolating the substrate from external corrosive media. After the formed coating is scratched, the corrosion inhibitor can be released to form a passivation film, which effectively inhibits the expansion of corrosion on the surface of the coating substrate.

[0024] According to the present invention, CIP@SiO 2 The mass ratio of particles to corrosion inhibitor is (9-12):(5-15); the conditions for ultrasonic dispersion are: power 180-250W, frequency 35-45KHz, time 5-20min, and temperature is room temperature; the conditions for evacuating the dispersed system are: vacuum degree 10-15Pa, time 2.5-3.5h, and temperature is room temperature.

[0025] In addition, the present invention also provides an application of a composite absorbing and anti-corrosion material in a corrosion-resistant absorbing coating. The composite absorbing and anti-corrosion material is used to prepare a corrosion-resistant absorbing coating material. The composite absorbing and anti-corrosion material is the aforementioned composite absorbing and anti-corrosion material with carbonyl iron as the core.

[0026] The composite wave-absorbing and anti-corrosion material of the present invention endows the coating with good electromagnetic wave absorption performance and corrosion resistance as a whole, and has strong corrosion inhibition ability, which effectively improves the corrosion resistance of the coating and prolongs the service life of the coating. The components in the coating material work synergistically, and have the characteristics of strong wave-absorbing performance, strong corrosion inhibition ability, long anti-corrosion life, and synergistic long-term protection. When coating, the coating material has low requirements on the substrate and can be constructed under relatively harsh construction environment conditions to achieve long-term wave-absorbing and anti-corrosion protection functions.

[0027] According to the present invention, the corrosion-resistant absorbing coating material includes resin, composite absorbing anti-corrosion material and curing agent, the mass ratio of resin to curing agent is (2-5):1; the mass ratio of resin to composite absorbing anti-corrosion material is (0.5-10):1.

[0028] (III) Beneficial technical effects

[0029] Compared with the prior art, the present invention has the following beneficial technical effects:

[0030] 1) Mesoporous SiO in the composite wave absorbing and anti-corrosion material of the present invention 2 The layer can enhance the microwave absorption and anti-corrosion performance of carbonyl iron particles, and the loaded corrosion inhibitor can further enhance its anti-corrosion ability, thereby effectively solving the problems of poor microwave absorption, poor oxidation and corrosion resistance, easy corrosion and aging failure of conventional carbonyl iron materials.

[0031] 2) The core-shell structure of the composite wave-absorbing and anti-corrosion material allows electromagnetic waves to reach the surface of the material and pass through SiO 2 The layer impedance matching reduces reflection and avoids CIP from contacting each other to form a conductive path, which reduces the dielectric constant and makes the impedance matching better, thus obtaining excellent wave absorbing performance; the shell can significantly reduce the agglomeration of CIP particles and improve their dispersion. When the thickness of the composite wave absorbing and anti-corrosion material is 1mm, the effective absorption bandwidth (reflection loss is less than -10dB) reaches 7.7GHz, and its wave absorbing performance is excellent.

[0032] 3) The preparation method of the present invention uses carbonyl iron particles as the main absorber to form the core body, and ethyl orthosilicate as the coated silicon source of the core body to form the mesoporous SiO 2 layer, and then fill the corrosion inhibitor into the mesoporous SiO 2 In the gaps of the layers, a composite absorbing and anti-corrosion material with a core-shell structure is formed. The method has a simple process, easy conditions to implement, can be carried out without high-temperature heating, has strong operability, and can be produced on a large scale. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention is clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work also fall within the scope of protection of the present invention.

[0034] The following examples use conventional instruments and equipment in the art. Unless otherwise specified, the test materials and reagents used in the following examples can be obtained from commercial sources, and their specifications are conventional specifications in the art. If no specific techniques or conditions are specified in the following examples, they can be carried out according to the techniques or conditions described in the literature in the art or according to the product instructions.

[0035] It should be noted that, in the present invention and the following embodiments, concentrations, ratios, etc. not otherwise specified are all weight concentrations, weight ratios, etc., "%" means weight percentage, and "parts" means parts by weight, which are common writing habits used by those skilled in the art and are therefore not described in detail in the present invention.

[0036] As a further improvement of the above implementation, the present invention also provides an improved method for preparing a composite wave absorbing and anticorrosive material with carbonyl iron as a core, comprising: dispersing a corrosion inhibitor in a mixed solution of ethanol and deionized water, adding CIP particles to the mixed solution, adding ammonia water to adjust the pH to 10, and then dropping tetraethyl orthosilicate into the obtained mixed system under stirring conditions, hydrolyzing the tetraethyl orthosilicate in the mixed system at room temperature, and then vacuuming the hydrolysis system, washing the obtained solid with ethanol for 1-3 times, and finally vacuum drying at 55-65°C to form a powdered CIP@SiO 2 - Corrosion inhibitor material. Moreover, the reaction operating conditions involved in the above method are consistent with those in the above preparation method.

[0037] In the improved preparation method, the corrosion inhibitor is dissolved in a mixed solution of ethanol and water, and during the hydrolysis of tetraethyl orthosilicate, the corrosion inhibitor is adsorbed on the mesoporous SiO 2 In the layer, the corrosion inhibitor M16 and BTA-16-BTA can also coordinate and assemble on the metal surface to achieve the corrosion inhibitor and SiO 2 Synergistic enhancement effect.

[0038] As a preferred embodiment, the composite wave-absorbing anti-corrosion material of the present invention can be applied to the fields of electromagnetic wave pollution protection and radar stealth. When the composite wave-absorbing anti-corrosion material is used to prepare a coating, the corrosion resistance of the coating is also significantly improved. Therefore, the composite wave-absorbing anti-corrosion material also has important application prospects in the fields of corrosion-resistant functional coatings, soft magnetic materials, etc.

[0039] As an improvement to the above implementation, examples of the resin in the corrosion-resistant absorbing coating material include, but are not limited to, epoxy resin, fluorocarbon resin, acrylic resin, silicone resin, etc., and may also be other resins that can form a film-like coating.

[0040] As an improvement to the above implementation, the above-mentioned corrosion-resistant and wave-absorbing coating material also includes functional additives such as leveling agents, penetrants, and rust inhibitors. The addition amounts of the above-mentioned various additives are common knowledge in the art and will not be repeated here. The leveling agent can enhance the coating performance of the coating material under humid working conditions, increase the continuity of the coating and the adhesion to the substrate; the penetrant can enhance the permeability of the coating material and promote the coating material to fully infiltrate and penetrate into the substrate; the rust inhibitor can further increase the adhesion area between the coating material and the substrate and improve the density of the coating.

[0041] It should be noted that when the above-mentioned corrosion-resistant and radar-absorbing coating material is applied as a coating, the coating method used is spraying or brushing. The present invention does not make specific requirements on the coating thickness, and those skilled in the art can set it according to actual conditions.

[0042] The present invention is further described in detail below in conjunction with the examples. However, it should be understood that the examples are for illustrative purposes only and are not intended to limit the scope of the present invention.

[0043] Embodiment 1:

[0044] A method for preparing a composite wave-absorbing and anti-corrosion material with carbonyl iron as a core body comprises the following steps:

[0045] 1) 100 g of CIP particles were dispersed in a mixed solution of ethanol and deionized water, and then ammonia was added to adjust the pH to 10. Then, 45 mL of tetraethyl orthosilicate was added dropwise at a speed of 0.05 mL / s under stirring conditions of 400 r / min. The tetraethyl orthosilicate in the mixed system was hydrolyzed at room temperature for 5 h to obtain CIP@SiO 2 In the mixed solution of ethanol and deionized water, the mass ratio of ethanol to water is 15:1. The particle size of the carbonyl iron particles is 1 μm.

[0046] 2) CIP@SiO 2 The particles were added to an ethanol solution containing the corrosion inhibitor M16 and ultrasonically dispersed for 10 min at a power of 200 W, a frequency of 40 kHz, and room temperature. The dispersion system was then evacuated, and the obtained solid was washed twice with ethanol and finally dried in a vacuum oven at 60 °C for 24 h to form a powdered CIP@SiO 2 -M16 material. CIP@SiO in the above ethanol solution 2 The mass ratio of particles to corrosion inhibitor is 10: 6. The conditions for evacuating the above dispersion system are: vacuum degree 10 Pa, time 3 h, and temperature is room temperature.

[0047] Embodiment 2:

[0048] A method for preparing a composite wave-absorbing and anti-corrosion material with carbonyl iron as a core body comprises the following steps:

[0049] 1) 140 g of CIP particles were dispersed in a mixed solution of ethanol and deionized water, and then ammonia was added to adjust the pH to 10. Then, 50 mL of tetraethyl orthosilicate was added dropwise at a speed of 0.10 mL / s under a stirring condition of 500 r / min, and the tetraethyl orthosilicate in the mixed system was hydrolyzed at room temperature for 6 h to obtain CIP@SiO 2 In the mixed solution of ethanol and deionized water, the mass ratio of ethanol to water is 16:1. The particle size of the carbonyl iron particles is 5 μm.

[0050] 2) CIP@SiO 2The particles were added to an ethanol solution containing corrosion inhibitor M16 and ultrasonically dispersed for 5 min at a power of 250 W, a frequency of 45 kHz, and room temperature. The dispersion system was then evacuated, and the solids were washed with ethanol three times and finally dried in a vacuum oven at 65 °C for 24 h to form a powdered CIP@SiO 2 -M16 material. CIP@SiO in the above ethanol solution 2 The mass ratio of particles to corrosion inhibitor is 12:5. The conditions for evacuating the above dispersion system are: vacuum degree 15 Pa, time 2.5 h, and temperature is room temperature.

[0051] Embodiment 3:

[0052] A method for preparing a composite wave-absorbing and anti-corrosion material with carbonyl iron as a core body comprises the following steps:

[0053] 1) 90 g of CIP particles were dispersed in a mixed solution of ethanol and deionized water, and then ammonia was added to adjust the pH to 10. Then, 40 mL of tetraethyl orthosilicate was added dropwise at a speed of 0.07 mL / s under stirring conditions of 350 r / min, and the tetraethyl orthosilicate in the mixed system was hydrolyzed at room temperature for 4 h to obtain CIP@SiO 2 In the mixed solution of ethanol and deionized water, the mass ratio of ethanol to water is 14:1. The particle size of the carbonyl iron particles is 10 μm.

[0054] 2) CIP@SiO 2 The particles were added to an ethanol solution containing corrosion inhibitor BTA-16-BTA, and ultrasonically dispersed for 20 min at a power of 180 W, a frequency of 35 kHz, and room temperature. The dispersion system was then evacuated, and the obtained solid was washed once with ethanol, and finally vacuum dried at 55 °C for 24 h to form a powdered CIP@SiO 2 -(BTA-16-BTA) material. CIP@SiO in the above ethanol solution 2 The mass ratio of particles to corrosion inhibitor is 9: 15. The conditions for evacuating the above dispersion system are: vacuum degree 10 Pa, time 2.5 h, and temperature is room temperature.

[0055] Embodiment 4:

[0056] A method for preparing a composite wave-absorbing and anti-corrosion material with carbonyl iron as a core body comprises the following steps:

[0057] 1) 150 g of CIP particles were dispersed in a mixed solution of ethanol and deionized water, and then ammonia was added to adjust the pH to 10. Then, 50 mL of tetraethyl orthosilicate was added dropwise at a speed of 0.10 mL / s under stirring conditions of 450 r / min. The tetraethyl orthosilicate in the mixed system was hydrolyzed at room temperature for 6 h to obtain CIP@SiO 2 In the mixed solution of ethanol and deionized water, the mass ratio of ethanol to water is 16:1. The particle size of the carbonyl iron particles is 8 μm.

[0058] 2) CIP@SiO 2 The particles were added to an ethanol solution containing corrosion inhibitor BTA-16-BTA, and ultrasonically dispersed for 15 min at a power of 230 W, a frequency of 40 kHz, and room temperature. The dispersion system was then evacuated, and the obtained solid was washed twice with ethanol and finally dried in a vacuum oven at 65 °C for 24 h to form a powdered CIP@SiO 2 -(BTA-16-BTA) material. CIP@SiO in the above ethanol solution 2 The mass ratio of particles to corrosion inhibitor is 12: 15. The conditions for evacuating the above dispersion system are: vacuum degree 15 Pa, time 3.5 h, and temperature is room temperature.

[0059] Embodiment 5:

[0060] A preparation method of a composite wave-absorbing and anti-corrosion material with carbonyl iron as a core body comprises the following steps: dispersing a corrosion inhibitor M16 in a mixed solution of ethanol and deionized water, adding 100 g of CIP particles to the mixed solution, adding ammonia water to adjust the pH to 10, and then dropping 45 mL of tetraethyl orthosilicate at a speed of 0.05 mL / s into the obtained mixed system under a stirring condition of a rotation speed of 400 r / min, hydrolyzing the tetraethyl orthosilicate in the mixed system at room temperature for 5 hours, and then vacuumizing the hydrolysis system, washing the obtained solid with ethanol twice, and finally vacuum drying at 60°C to form a powdered CIP@SiO 2 -M16 material. In the mixed solution of ethanol and deionized water, the mass ratio of ethanol to water is 15:1. The particle size of the carbonyl iron particles is 1 μm. The CIP@SiO 2 The mass ratio of particles to corrosion inhibitor is 10: 6. The conditions for evacuating the above dispersion system are: vacuum degree 10 Pa, time 3 h, and temperature is room temperature.

[0061] Comparative Example 1:

[0062] A preparation method of a composite wave-absorbing and anti-corrosion material with carbonyl iron as a core body comprises the following steps: dispersing 100 g of CIP particles in a mixed solution of ethanol and deionized water, then adding ammonia water to adjust the pH to 10, then dripping 45 mL of tetraethyl orthosilicate at a speed of 0.05 mL / s into the obtained mixed system under a stirring condition of a rotation speed of 400 r / min, and hydrolyzing the tetraethyl orthosilicate in the mixed system at room temperature for 5 hours to obtain CIP@SiO 2 The composite wave absorbing and anti-corrosion material is obtained by mixing the ethanol and deionized water in a mixed solution, wherein the mass ratio of the ethanol to the water is 15:1. The particle size of the carbonyl iron particles is 1 μm. The composite wave absorbing and anti-corrosion material is not formed in the mesoporous SiO 2 The corrosion inhibitor is loaded in the layer.

[0063] Test Example 1:

[0064] Wave absorption performance test

[0065] Test method: Take the composite absorbing and anticorrosive materials prepared in Example 1, Example 3, Example 5 and Comparative Example 1 as test samples, and take CIP particles as the control group. Coating preparation: Mix the samples with epoxy resin 901-75 at a mass ratio of 1:1, then add 2115 curing agent and mix evenly. The mass ratio of 2115 curing agent to resin is 3:1. Then brush the coating material evenly on the polytetrafluoroethylene film. The coating thickness is 1mm. After curing and molding under the same conditions (temperature 60°C, time 10h), the absorbing coating sample is obtained. The absorbing performance is tested by a vector network analyzer. The basic accuracy of the instrument is ±0.8%. The test frequency range is 1-18GHz. The difference in the frequency range where the reflection loss is less than -10dB is taken as the effective absorption bandwidth. Each test example is set up with 3 parallels, and the results are averaged. The results are shown in Table 1.

[0066] Table 1

[0067] Example 1 Example 3 Example 5 Comparative Example 1 Control group Effective absorption bandwidth GHz 7.7 7.5 7.6 7.4 5.3

[0068] The results show that setting different shells on the surface of CIP particles can significantly enhance their microwave absorption performance. 2 The layer can also improve the absorbing performance, and in the present invention, the loaded corrosion inhibitor can further improve the absorbing ability of the composite absorbing and anti-corrosion material and coating.

[0069] Test Example 2:

[0070] Antioxidant performance test

[0071] Test method: The composite wave absorbing and anticorrosive materials prepared in Example 1, Example 3, Example 5 and Comparative Example 1 were respectively taken as test samples, and CIP particles were taken as the control group. The anti-oxidation performance was characterized by thermogravimetric test. The thermogravimetric test was performed on each sample in the temperature range of 20-600°C using a WCT-2D microcomputer differential thermal balance, under air atmosphere conditions, with a heating rate of 10°C / min. Three parallels were set for each test example, and the results were averaged. The results are shown in Table 2.

[0072] Table 2

[0073] Example 1 Example 3 Example 5 Comparative Example 1 Control group Oxidation initial temperature ℃ 410 413 406 400 220

[0074] The results show that the CIP@SiO 2 -The corrosion inhibitor in M16 material is affected by mesoporous SiO 2 The protective effect of the layer, the decomposition of the corrosion inhibitor is delayed, resulting in an increase in its decomposition temperature. The decomposition of M16 will not occur until the temperature rises to about 240°C, and then the oxidation will begin when the temperature rises to 410°C and 406°C respectively. Comparison shows that the composite absorbing and anti-corrosion material loaded with corrosion inhibitor in the present invention has the best antioxidant performance, showing excellent temperature resistance and antioxidant properties, which is beneficial to increase the antioxidant property and service life of the coating during use.

[0075] Test Example 3:

[0076] Corrosion resistance test

[0077] Test samples: The composite absorbing and anticorrosive materials prepared in Example 1, Example 3, Example 5 and Comparative Example 1 were taken as test samples, and CIP particles were taken as the control group. Coating preparation: The samples were mixed with epoxy resin 901-75 at a mass ratio of 1:1, and then 2115 curing agent was added and mixed evenly. The mass ratio of 2115 curing agent to resin was 3:1, and then the coating material was evenly brushed on the 60mm×60mm×3mm tinplate surface, with a coating thickness of 70mm. After curing and molding under the same conditions (temperature 60°C, time 10h), the absorbing coating sample was obtained. Each test example was set with 3 parallels, and the results were averaged. The results are shown in Table 3.

[0078] 1) Alternating salt spray test: The test is carried out in accordance with GJB150.11A-2009 standard. The spraying is carried out alternately in a standard salt spray chamber with a cycle of spraying for 24 hours-stopping for 24 hours-spraying for 24 hours-stopping for 24 hours. The test period is 660 hours.

[0079] 2) Electrochemical impedance measurement: The electrochemical method is used for measurement. In a normal three-electrode system, a saturated KCl solution is used as the reference electrode, a platinum electrode is used as the counter electrode, and the tinplate covered with the coating is used as the working electrode. The test is conducted in a 3.5% NaCl solution, and the open circuit voltage is stabilized by soaking for 3 hours before the test.

[0080] Table 3

[0081]

[0082]

[0083] The results show that the initial corrosion time of the composite absorbing and anticorrosive material loaded with corrosion inhibitor in Example 1 is 1.69 times that of the CIP material in the control group, which is 1.69 times that of the composite absorbing and anticorrosive material loaded with corrosion inhibitor in Example 1. 2 The impedance value of Example 1 is also significantly increased. It can be seen that in salt spray environment and immersion environment, the corrosion inhibitor is 2 The effect of the layer causes its release rate to be relatively slow, which prolongs the action time of the corrosion inhibitor in the coating, thereby increasing the service life of the coating; it also shows that the corrosion resistance and corrosion inhibition ability of the composite absorbing and anti-corrosion material loaded with corrosion inhibitor in the present invention are significantly increased, so that its coating has long-term anti-corrosion performance and can meet the coating and anti-corrosion requirements under humid working conditions.

[0084] Test example 4:

[0085] Acid and alkali resistance test

[0086] Test method: Take the composite absorbing and anticorrosive materials of Examples 1 to 5 and Comparative Example 1 and the control group materials respectively, prepare coating samples according to the method in Test Example 3, and soak the coating samples in 10wt% H 2 SO 4 After 96 hours in solution, 10wt% NaOH solution and 3wt% NaCl solution, the corrosion condition of the tinplate substrate surface was detected, and each test example was set up with 3 parallels.

[0087] The results show that the coating surfaces of Examples 1 to 5 have no obvious discoloration or blistering, and the coatings are not peeled off and are in good condition; the coating of Comparative Example 1 has blistering and slight rust; the coating of the control group has blistering and serious rust. This indicates that the composite absorbing and anticorrosive material loaded with corrosion inhibitors and its coating in the present invention have excellent acid and alkali resistance, excellent corrosion resistance and corrosion inhibition ability, and are suitable for application on metal materials in harsh marine environments, and can increase the service life of metal substrates or components in seawater.

[0088] It should be noted that in the present invention, the detailed steps of some operations are not described in detail, but belong to the prior art known to those skilled in the art, so they will not be repeated here. In addition, in the present invention, all features such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are only for simplicity and convenience. Accordingly, the description of numerical ranges or percentage ranges should be deemed to have covered and specifically disclosed all possible secondary ranges and individual values ​​(including integers and fractions) within the range.

[0089] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit them. In the present invention, not all possible combinations of the various technical features in the various embodiments or embodiments are described. As long as there is no contradiction in the combination of these technical features, the various technical features in the various embodiments or embodiments can be arbitrarily combined, and all possible combinations should be considered to be within the scope of this specification. Although the present invention has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A composite microwave absorbing and anti-corrosion material with carbonyl iron as the core, characterized in that: include: Carbonyl iron particles, wherein the carbonyl iron particles are core bodies; A mesoporous SiO2 layer, wherein the mesoporous SiO2 layer is coated on the surface of the carbonyl iron particles to form a shell; and A corrosion inhibitor loaded in the mesoporous SiO2 layer; The particle size of the carbonyl iron particles is 1-20 μm; The corrosion inhibitor is an imidazole ammonium salt corrosion inhibitor or a benzoheterocyclic corrosion inhibitor.

2. The composite microwave absorbing and anti-corrosion material with carbonyl iron as the core according to claim 1, characterized in that: The corrosion inhibitor is an imidazole ammonium salt corrosion inhibitor, and its chemical structure is shown in formula (I):

3. The composite microwave absorbing and anti-corrosion material with carbonyl iron as the core according to claim 1, characterized in that: The corrosion inhibitor is a benzoheterocyclic corrosion inhibitor, and its chemical structure is shown in formula (II): Wherein, R is a C16 alkyl group.

4. A method for preparing a composite microwave absorbing and anti-corrosion material with carbonyl iron as a core, characterized in that: include: Using the Stober hydrolysis method to coat the surface of carbonyl iron particles with a mesoporous SiO2 layer to obtain CIP@SiO2 particles; and, Adsorbing and loading the corrosion inhibitor on the surface of CIP@SiO2 particles by vacuum impregnation method to obtain a powdered CIP@SiO2-corrosion inhibitor material, which is the composite wave-absorbing and anti-corrosion material with carbonyl iron as the core body as described in any one of claims 1 to 3; The corrosion inhibitor is an imidazole ammonium salt corrosion inhibitor or a benzoheterocyclic corrosion inhibitor; The chemical structure of the imidazole ammonium salt corrosion inhibitor is shown in formula (I): The chemical structure of the benzoheterocyclic corrosion inhibitor is shown in formula (II): Wherein, R is a C16 alkyl group.

5. The method for preparing a composite microwave absorbing and anti-corrosion material with carbonyl iron as a core according to claim 4, characterized in that: The preparation steps of the CIP@SiO2 particles are as follows: CIP particles are dispersed in a mixed solution of ethanol and deionized water, and then ammonia water is added to adjust the pH to 10, and then tetraethyl orthosilicate is added dropwise to the obtained mixed system under stirring conditions, and the tetraethyl orthosilicate in the mixed system is hydrolyzed at room temperature to obtain CIP@SiO2 particles.

6. The method for preparing the composite microwave absorbing and anticorrosive material with carbonyl iron as the core according to claim 5, characterized in that: In the mixed solution of ethanol and deionized water, the mass ratio of ethanol to water is (14-16):1; the added amount of the CIP particles is 90-150 g, and the added amount of tetraethyl orthosilicate is 40-50 mL; the stirring speed is 350-500 r / min, the dropping speed is 0.05-0.10 mL / s, and the hydrolysis time is 4-6 h.

7. The method for preparing a composite microwave absorbing and anti-corrosion material with carbonyl iron as a core according to claim 4, characterized in that: The steps of the vacuum impregnation method are as follows: adding CIP@SiO2 particles to an ethanol solution containing a corrosion inhibitor, ultrasonically dispersing them uniformly, then evacuating the dispersion system, washing the resulting solid with ethanol for 1-3 times, and finally vacuum drying at 55-65°C for 24 hours to form a powdered CIP@SiO2-corrosion inhibitor material.

8. The method for preparing a composite microwave absorbing and anti-corrosion material with carbonyl iron as a core according to claim 7, characterized in that: The mass ratio of CIP@SiO2 particles to corrosion inhibitor in the ethanol solution is (9-12):(5-15); the conditions for ultrasonic dispersion are: power 180-250W, frequency 35-45KHz, time 5-20min, and temperature is room temperature; the conditions for vacuuming the dispersed system are: vacuum degree 10-15Pa, time 2.5-3.5h, and temperature is room temperature.

9. Application of a composite absorbing and anti-corrosion material in a corrosion-resistant absorbing coating, characterized in that: The composite wave-absorbing and anti-corrosion material is used to prepare a corrosion-resistant wave-absorbing coating material. The composite wave-absorbing and anti-corrosion material is the composite wave-absorbing and anti-corrosion material with carbonyl iron as the core body as described in any one of claims 1 to 3.

10. The use of the composite absorbing and anti-corrosion material according to claim 9 in a corrosion-resistant absorbing coating, characterized in that: The corrosion-resistant absorbing coating material includes resin, composite absorbing and anti-corrosion material and curing agent, the mass ratio of the resin to the curing agent is (2-5):1; the mass ratio of the resin to the composite absorbing and anti-corrosion material is (0.5-10):1.

Images