Iron-based magnetic absorbent with corrosion early warning and inhibition functions as well as preparation method and application of iron-based magnetic absorbent

Abstract

The invention discloses an iron-based magnetic absorbent with corrosion early warning and inhibition functions as well as a preparation method and application thereof, and relates to the technical field of electromagnetic wave absorbing materials. The method comprises the following steps: adding an absorbent, a silane coupling agent and ammonia water into a mixed solvent, and mixing and reacting to obtain dispersion liquid of the silane coupling agent surface treatment absorbent; and adding 1, 10-phenanthroline and / or a 1, 10-phenanthroline derivative into the dispersion liquid, stirring and mixing, and centrifugally drying to obtain the modified iron-based magnetic absorbent. A silane coupling agent is used for treating the surface of an absorbent to enhance the resin-absorbent interface bonding force, and then 1, 10-phenanthroline and derivatives thereof are deposited on the surface of the absorbent through a chemical deposition method.

Description

Technical Field

[0001] The invention relates to the technical field of electromagnetic absorbing materials, and in particular to an iron-based magnetic absorber with corrosion early warning and suppression functions, a preparation method and an application thereof. Background Art

[0002] The increasing demand for modern equipment to hide itself makes absorbing materials increasingly important. Absorbing materials can absorb and dissipate incident electromagnetic waves, reduce the radar reflection area of ​​the target, and effectively improve the survival rate of equipment systems in specific environments. Iron-based magnetic absorbers have the advantages of high magnetic permeability and large magnetic loss, and are currently a commonly used type of electromagnetic absorber. However, ferromagnetic materials are prone to corrosion in high humidity, high salt and other environments, which leads to a decrease in absorbing performance. In order to ensure that iron-based magnetic absorbers can serve for a long time in extremely corrosive environments, they must be modified to resist corrosion.

[0003] In actual environments, corrosion mostly starts from tiny pitting, and absorbers are usually embedded in resins, making corrosion difficult to detect. When rust spots appear on the coating surface, the material's absorbing performance has been severely damaged. In order to prevent the dangerous situation of failure of absorbing performance, it is necessary to establish an early warning-suppression mechanism so that the corrosion of the absorbing coating can be detected and suppressed in time at the early stage, which facilitates subsequent manual repairs and delays the deterioration of coating corrosion as much as possible.

[0004] 1,10-Phenanthroline is a commonly used metal complexing agent that can react with Fe 2+ The orange-red complex is generated, which makes the occurrence of corrosion visible and warns of the occurrence of corrosion; the complex can also be adsorbed on the metal surface to form a dense protective layer, repair the barrier effect of the coating, and inhibit further corrosion. In the prior art, a self-repairing mechanism is used to enhance the corrosion resistance of carbonyl iron coatings, but there is no report on the corrosion warning-inhibition mechanism. If this mechanism can be applied to iron-based magnetic absorbers, their corrosion problems can be dealt with more effectively. Summary of the invention

[0005] In view of the deficiencies in the above-mentioned background technology, the present invention mainly solves the problem that the corrosion of iron-based magnetic absorbents in the prior art is difficult to detect and inhibit in the early stage. The present invention provides an iron-based magnetic absorbent with corrosion warning and inhibition functions, as well as a preparation method and application. The method first uses a silane coupling agent to treat the surface of the absorbent to enhance the resin-absorbent interface bonding force, and then deposits 1,10-phenanthroline and its derivatives on the surface of the absorbent by chemical deposition. Once the absorbent is corroded, 1,10-phenanthroline and its derivatives will react with the Fe generated by the corrosion. 2+ The ions combine to form a red complex to warn of corrosion; at the same time, they are adsorbed on the corroded area to form a protective film to repair the corroded damaged area.

[0006] The first object of the present invention is to provide a method for preparing an iron-based magnetic absorbent having corrosion early warning and inhibition functions, comprising the following steps:

[0007] Adding absorbent, silane coupling agent and ammonia water into a mixed solvent, mixing and reacting, and obtaining a dispersion of silane coupling agent surface treated absorbent;

[0008] Adding 1,10-phenanthroline and / or 1,10-phenanthroline derivatives to the dispersion, stirring and mixing, and centrifugally drying to obtain a modified iron-based magnetic absorbent;

[0009] Wherein, the mixed solvent is prepared from water and anhydrous ethanol.

[0010] Preferably, the absorbent is one of carbonyl iron, iron-silicon-aluminum alloy, iron-silicon-chromium alloy, iron-silicon alloy, iron-aluminum-boron alloy or amorphous alloy, iron-boron-phosphorus alloy or amorphous alloy, iron-nickel alloy, iron-nickel-molybdenum alloy, iron-chromium-nickel alloy, iron-cobalt-chromium alloy, and iron-cobalt-nickel-chromium alloy; the absorbent is spherical or flaky in shape, with a particle size of 3-40 μm.

[0011] Preferably, the silane coupling agent is one or more of KH-550, KH-560, and KH-792.

[0012] Preferably, the mass ratio of the absorbent, the silane coupling agent and the ammonia water is (50-80):(5-30):(0.5-4).

[0013] Preferably, the mass ratio of the 1,10-phenanthroline or 1,10-phenanthroline derivative to the absorbent is (5-10):(50-80).

[0014] Preferably, the 1,10-phenanthroline derivative is 1,10-phenanthroline-5-amine and / or 1,10-phenanthroline monohydrate.

[0015] Preferably, the mixing reaction comprises: stirring at 500-800 rpm and keeping warm at 60-80° C. for 3-6 hours;

[0016] The stirring and mixing is performed at 500-800 rpm for 1-3 hours; the centrifugal drying is performed at 8000-10000 rpm for 5-10 minutes, and then drying is performed at 60-80° C. for 10-14 hours.

[0017] Preferably, the mass ratio of the anhydrous ethanol to water is 1:1-8.

[0018] The second object of the present invention is to provide an iron-based magnetic absorbent having corrosion warning and inhibition functions.

[0019] The third object of the present invention is to provide an iron-based magnetic absorbent with corrosion warning and inhibition functions for use in electromagnetic absorption.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] The present invention provides an iron-based magnetic absorbent with corrosion warning and inhibition functions, as well as a preparation method and application. The present invention aims at the problem that iron-based magnetic absorbents are easy to corrode and difficult to detect, and provides a modified iron-based magnetic absorbent with corrosion warning and inhibition functions. First, the silane coupling agent is hydrolyzed, condensed and adsorbed on the surface of the absorbent, and the functional group at the other end is used to bond with the active hydroxyl group and amino group in the resin to enhance the interface interaction between the absorbent and the resin. Then, 1,10-phenanthroline and its derivatives are deposited on the surface of the absorbent by physical adsorption. 1,10-phenanthroline and its derivatives are used to bond with Fe 2+ The generated complex develops color to warn of the occurrence of corrosion. At the same time, the generated complex can be adsorbed on the surface of the absorbent to form a protective film, repair the corroded area, and inhibit the progress of corrosion, thereby realizing a corrosion warning-inhibition mechanism suitable for iron-based magnetic absorbents. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 The actual color pictures of the systems of the embodiments and comparative examples after immersion for 1 hour. DETAILED DESCRIPTION

[0023] In order to enable those skilled in the art to better understand and implement the technical solution of the present invention, the present invention is further described below in conjunction with specific embodiments, but the embodiments are not intended to limit the present invention.

[0024] The purpose of the present invention is to provide an iron-based magnetic absorbent with corrosion warning and inhibition functions and a preparation method thereof in view of the problem that the corrosion of iron-based magnetic absorbents is difficult to detect and inhibit in the early stage. The method first uses a silane coupling agent to treat the absorbent surface to enhance the resin-absorbent interface bonding force, and then deposits 1,10-phenanthroline and its derivatives on the absorbent surface by chemical deposition. Once the absorbent is corroded, 1,10-phenanthroline and its derivatives will react with the Fe generated by the corrosion. 2+ The ions combine to form a red complex to warn of corrosion; at the same time, they are adsorbed on the corroded area to form a protective film to repair the corroded damaged area.

[0025] In order to achieve the above object, the first aspect of the present invention provides a method for preparing an iron-based magnetic absorbent having corrosion warning and inhibition functions, comprising the following steps:

[0026] Adding absorbent, silane coupling agent and ammonia water into a mixed solvent, mixing and reacting, and obtaining a dispersion of silane coupling agent surface treated absorbent;

[0027] Adding 1,10-phenanthroline and / or 1,10-phenanthroline derivatives to the dispersion, stirring and mixing, and centrifugally drying to obtain a modified iron-based magnetic absorbent;

[0028] Wherein, the mixed solvent is prepared from water and anhydrous ethanol

[0029] The mass ratio of the anhydrous ethanol to water is 1:1-8.

[0030] The modified iron-based magnetic absorbent provided by the present invention is prepared by using an iron-based magnetic absorbent as a substrate, using a silane coupling agent for surface treatment and depositing 1,10-phenanthroline and its derivatives. 1,10-phenanthroline and its derivatives can react with Fe generated by the corrosion of the absorbent. 2+ The ions generate bright orange-red complexes, thus warning of corrosion. They can also be adsorbed on the surface of the absorbent to repair the corroded area. The addition of silane coupling agents can enhance the surface activity of the absorbent and strengthen the combination of the absorbent and the resin.

[0031] Wherein, the absorbent is one of carbonyl iron, iron-silicon-aluminum alloy, iron-silicon-chromium alloy, iron-silicon alloy, iron-aluminum-boron alloy or amorphous alloy, iron-boron-phosphorus alloy or amorphous alloy, iron-nickel alloy, iron-nickel-molybdenum alloy, iron-chromium-nickel alloy, iron-cobalt-chromium alloy, and iron-cobalt-nickel-chromium alloy; the absorbent is spherical or flaky in shape, with a particle size of 3-40 μm.

[0032] The silane coupling agent is one or more of KH-550, KH-560 and KH-792.

[0033] The mass ratio of the absorbent, the silane coupling agent and the ammonia water is (50-80):(5-30):(0.5-4).

[0034] The mass ratio of the 1,10-phenanthroline or 1,10-phenanthroline derivative to the absorbent is (5-10):(50-80).

[0035] The 1,10-phenanthroline derivative is 1,10-phenanthroline-5-amine and / or 1,10-phenanthroline monohydrate.

[0036] The mixing reaction includes: stirring at 500-800 rpm and keeping warm at 60-80° C. for 3-6 hours;

[0037] The stirring and mixing is performed at 500-800 rpm for 1-3 hours; the centrifugal drying is performed at 8000-10000 rpm for 5-10 minutes, and then drying is performed at 60-80° C. for 10-14 hours.

[0038] In one embodiment, a method for preparing an iron-based magnetic absorbent having corrosion warning and inhibition functions comprises the following steps:

[0039] Step 1: Calculate by mass: first prepare 200-500 parts of a mixed solvent with deionized water and anhydrous ethanol, add 50-80 parts of absorbent powder, then add 5-30 parts of silane coupling agent and 0.5-4 parts of ammonia water, stir evenly, heat in a water bath, and obtain a dispersion of the absorbent surface treated with a silane coupling agent.

[0040] Step 2: Take 5-10 parts of 1,10-phenanthroline and its derivatives, add them into the dispersion, stir and mix them thoroughly, and centrifuge and dry them to obtain a modified carbonyl iron absorbent.

[0041] The mass ratio of deionized water to anhydrous ethanol in the mixed solvent described in step 1 is (2-8): (1-2).

[0042] The absorbent powder described in step one is one of carbonyl iron, iron silicon aluminum alloy, iron silicon chromium alloy, iron silicon alloy, iron aluminum boron alloy or amorphous alloy, iron boron phosphorus alloy or amorphous alloy, iron nickel alloy, iron nickel molybdenum alloy, iron chromium nickel alloy, iron cobalt chromium alloy, and iron cobalt nickel chromium alloy, and is spherical or flaky in shape with a particle size of 3-40 μm.

[0043] The silane coupling agent described in step 1 is one or more of KH-550, KH-560, and KH-792. The function of the silane coupling agent is to enhance the active groups on the surface of the absorbent and strengthen the bonding with the resin.

[0044] The stirring rate in step 1 is 500-800 rpm; the water bath heating temperature is 60-80° C., and the heating time is 3-6 h.

[0045] The 1,10-phenanthroline and its derivatives described in step 2 are one or more of 1,10-phenanthroline, 1,10-phenanthroline-5-amine, and 1,10-phenanthroline-monohydrate. 1,10-phenanthroline and its derivatives can react with Fe 2+ Ion coordination provides early warning of corrosion.

[0046] The stirring parameter described in step 2 is 500-800rpm, 1-3h; the centrifugation parameter is 8000-10000rpm for 5-10 minutes; and the drying parameter is 60-80℃ for 10-14h.

[0047] The second aspect of the present invention provides an iron-based magnetic absorbent having corrosion warning and inhibition functions.

[0048] A third aspect of the present invention provides an application of an iron-based magnetic absorbent having corrosion warning and inhibition functions in electromagnetic absorption.

[0049] It should be noted that the experimental methods used in the present invention are all conventional methods unless otherwise specified; the reagents and materials used are all commercially available unless otherwise specified.

[0050] Example 1

[0051] Step 1: First, prepare 200 parts of a mixed solvent with a mass ratio of 5:1 with deionized water and anhydrous ethanol, add 50 parts of carbonyl iron powder, then add 5 parts of KH-550 coupling agent, 1 part of KH-560 coupling agent, and 1 part of ammonia water, stir evenly at 500 rpm, and heat in a water bath at 60°C for 3 hours to obtain a dispersion of the absorbent surface treated with a silane coupling agent.

[0052] Step 2: Take 5 parts of 1,10-phenanthroline and 1 part of 1,10-phenanthroline-5-amine, add them to the dispersion, stir and mix at 500 rpm for 1 hour, centrifuge at 8000 rpm for 10 minutes, and dry at 60°C for 12 hours to obtain a modified iron-based magnetic absorbent.

[0053] Example 2

[0054] Step 1: First, prepare 200-500 parts of a mixed solvent with a mass ratio of 5:1 with deionized water and anhydrous ethanol, add 60 parts of sendustine alloy powder, then add 5 parts of KH-550 coupling agent, 2 parts of KH-560 coupling agent, and 2 parts of ammonia water, stir evenly at 600 rpm, heat in a water bath at 60°C for 4 hours, and obtain a dispersion of the absorbent surface treated with a silane coupling agent.

[0055] Step 2: Take 5 parts of 1,10-phenanthroline and 2 parts of 1,10-phenanthroline-5-amine and add them to the dispersion, stir and mix at 800 rpm for 1 hour, centrifuge at 8000 rpm for 10 minutes, and dry at 80°C for 12 hours to obtain a modified iron-based magnetic absorbent.

[0056] Example 3

[0057] Step 1: First, prepare 300 parts of a mixed solvent with a mass ratio of 5:2 with deionized water and anhydrous ethanol, add 80 parts of iron-silicon-chromium alloy powder, then add 10 parts of KH-550 coupling agent, 1 part of KH-792 coupling agent, and 3 parts of ammonia water, stir evenly at 600 rpm, and heat in a water bath at 80°C for 3 hours to obtain a dispersion of the absorbent surface treated with a silane coupling agent.

[0058] Step 2: Take 8 parts of 1,10-phenanthroline-5-amine and 1 part of 1,10-phenanthroline monohydrate, add them to the dispersion, stir and mix at 800 rpm for 1 hour, centrifuge at 10000 rpm for 5 minutes, and dry at 80°C for 12 hours to obtain a modified iron-based magnetic absorbent.

[0059] Example 4

[0060] Step 1: First, prepare 200 parts of a mixed solvent with a mass ratio of 8:1 with deionized water and anhydrous ethanol, add 50 parts of iron-silicon alloy powder, then add 5 parts of KH-550 coupling agent, 1 part of KH-560 coupling agent, and 1 part of ammonia water, stir evenly at 500 rpm, and heat in a water bath at 60°C for 6 hours to obtain a dispersion of the absorbent surface treated with a silane coupling agent.

[0061] Step 2: Take 5 parts of 1,10-phenanthroline and 2 parts of 1,10-phenanthroline-5-amine, add them to the dispersion, stir and mix at 800 rpm for 1 hour, centrifuge at 8000 rpm for 5 minutes, and dry at 80°C for 10 hours to obtain a modified iron-based magnetic absorbent.

[0062] Example 5

[0063] Step 1: First, prepare 300 parts of a mixed solvent with a mass ratio of 5:2 with deionized water and anhydrous ethanol, add 60 parts of iron-aluminum-boron alloy or amorphous alloy, then add 10 parts of KH-550 coupling agent, 1 part of KH-560 coupling agent, and 2 parts of ammonia water, stir evenly at 500 rpm, and heat in a water bath at 80°C for 3 hours to obtain a dispersion of the absorbent surface treated with a silane coupling agent.

[0064] Step 2: Take 5 parts of 1,10-phenanthroline and 1 part of 1,10-phenanthroline monohydrate, add them to the dispersion, stir and mix at 500 rpm for 3 hours, centrifuge at 8000 rpm for 10 minutes, and dry at 80°C for 12 hours to obtain a modified iron-based magnetic absorbent.

[0065] Example 6

[0066] Step 1: First, prepare 500 parts of a mixed solvent with a mass ratio of 5:1 with deionized water and anhydrous ethanol, add 80 parts of iron-boron-phosphorus alloy or amorphous alloy, then add 20 parts of KH-550 coupling agent, 1 part of KH-560 coupling agent, and 4 parts of ammonia water, stir evenly at 800 rpm, heat in a water bath at 80°C for 6 hours, and obtain a dispersion of the absorbent surface treated with a silane coupling agent.

[0067] Step 2: Take 9 parts of 1,10-phenanthroline and 1 part of 1,10-phenanthroline-5-amine, add them to the dispersion, stir and mix at 800 rpm for 3 hours, centrifuge at 10000 rpm for 5 minutes, and dry at 80°C for 14 hours to obtain a modified iron-based magnetic absorbent.

[0068] Example 7

[0069] Step 1: First, prepare 200 parts of a mixed solvent with a mass ratio of 5:1 with deionized water and anhydrous ethanol, add 50 parts of iron-nickel alloy powder, then add 5 parts of KH-550 coupling agent, 1 part of KH-792 coupling agent, and 1 part of ammonia water, stir evenly at 500 rpm, and heat in a water bath at 60°C for 3 hours to obtain a dispersion of the absorbent surface treated with a silane coupling agent.

[0070] Step 2: Take 5 parts of 1,10-phenanthroline and 1 part of 1,10-phenanthroline-5-amine, add them to the dispersion, stir and mix at 500 rpm for 2 hours, centrifuge at 8000 rpm for 5 minutes, and dry at 80°C for 10 hours to obtain a modified iron-based magnetic absorbent.

[0071] Example 8

[0072] Step 1: First, prepare 300 parts of a mixed solvent with a mass ratio of 5:1 with deionized water and anhydrous ethanol, add 60 parts of iron-nickel-molybdenum alloy powder, then add 10 parts of KH-550 coupling agent, 1 part of KH-560 coupling agent, and 2 parts of ammonia water, stir evenly at 800 rpm, heat in a water bath at 80°C for 6 hours, and obtain a dispersion of the absorbent surface treated with a silane coupling agent.

[0073] Step 2: Take 1 part of 1,10-phenanthroline and 5 parts of 1,10-phenanthroline-5-amine, add them to the dispersion, stir and mix at 800 rpm for 3 hours, centrifuge at 10000 rpm for 10 minutes, and dry at 80°C for 12 hours to obtain a modified iron-based magnetic absorbent.

[0074] Example 9

[0075] Step 1: First, prepare 300 parts of a mixed solvent with a mass ratio of 5:1 with deionized water and anhydrous ethanol, add 60 parts of iron-chromium-nickel alloy powder, then add 10 parts of KH-550 coupling agent, 1 part of KH-560 coupling agent, and 2 parts of ammonia water, stir evenly at 800 rpm, and heat in a water bath at 80°C for 3 hours to obtain a dispersion of the absorbent surface treated with a silane coupling agent.

[0076] Step 2: Take 5 parts of 1,10-phenanthroline and 1 part of 1,10-phenanthroline-5-amine, add them to the dispersion, stir and mix at 800 rpm for 3 hours, centrifuge at 8000 rpm for 10 minutes, and dry at 80°C for 12 hours to obtain a modified iron-based magnetic absorbent.

[0077] Example 10

[0078] Step 1: First, prepare 300 parts of a mixed solvent with a mass ratio of 5:1 with deionized water and anhydrous ethanol, add 60 parts of iron-cobalt-chromium alloy powder, then add 10 parts of KH-550 coupling agent, 1 part of KH-560 coupling agent, and 2 parts of ammonia water, stir evenly at 800 rpm, and heat in a water bath at 80°C for 6 hours to obtain a dispersion of the absorbent surface treated with a silane coupling agent.

[0079] Step 2: Take 5 parts of 1,10-phenanthroline and 1 part of 1,10-phenanthroline-5-amine, add them to the dispersion, stir and mix at 800 rpm for 3 hours, centrifuge at 8000 rpm for 10 minutes, and dry at 80°C for 12 hours to obtain a modified iron-based magnetic absorbent.

[0080] Embodiment 11

[0081] Step 1: First, prepare 300 parts of a mixed solvent with a mass ratio of 5:1 with deionized water and anhydrous ethanol, add 60 parts of iron-cobalt-nickel-chromium alloy powder, then add 10 parts of KH-550 coupling agent, 1 part of KH-560 coupling agent, and 2 parts of ammonia water, stir evenly at 800 rpm, and heat in a water bath at 80°C for 3 hours to obtain a dispersion of the absorbent surface treated with a silane coupling agent.

[0082] Step 2: Take 5 parts of 1,10-phenanthroline and 1 part of 1,10-phenanthroline-5-amine, add them to the dispersion, stir and mix at 800 rpm for 3 hours, centrifuge at 10000 rpm for 5 minutes, and dry at 80°C for 12 hours to obtain a modified iron-based magnetic absorbent.

[0083] Comparative Example 1

[0084] Step 1: First, prepare 300 parts of a mixed solvent with a mass ratio of 5:1 with deionized water and anhydrous ethanol, add 60 parts of iron-cobalt-nickel-chromium alloy powder, then add 10 parts of KH-550 coupling agent, 1 part of KH-560 coupling agent, and 2 parts of ammonia water, stir evenly at 800rpm, heat in a water bath at 80℃ for 3h, centrifuge at 10000rpm for 5 minutes, and dry at 80℃ for 12h to obtain a modified iron-based magnetic absorbent.

[0085] In order to illustrate the corrosion warning and inhibition capabilities of the modified iron-based magnetic absorbent provided by the present invention, an equal amount of the modified iron-based magnetic absorbent prepared in each embodiment and comparative example was immersed in a 3.5wt.% NaCl solution to test the Fe 2+ The changes in ion concentration and the color changes of the system are observed. The specific results are shown in Table 1 and Figure 1 shown.

[0086] Table 1 Fe of each embodiment and comparative example at different times 2+ Concentration and system color

[0087]

[0088]

[0089] As shown in Table 1, Fe 2+ The presence of ions proves that the samples have been corroded. Figure 1 It can be seen that each example can show an obvious orange-red color in 1 hour, while the comparative example is colorless, which proves that the 1,10-phenanthroline contained in the modified iron-based magnetic absorbent can react with Fe 2+ The ions generate red complexes, thus providing an early warning of corrosion. 2+The ion concentration at 6h and 12h is much lower than that of the comparative example, indicating that the corrosion in the example is weaker. This shows that the generated complex can be adsorbed on the surface of the absorbent to form a protective film, so that the modified iron-based magnetic absorbent has a corrosion inhibition function.

[0090] In order to illustrate the wave absorbing performance of the modified iron-based magnetic absorber, the modified iron-based magnetic absorber prepared in each embodiment and comparative example of the present invention was mixed with epoxy resin to prepare a coating, and the corresponding coating was prepared by spraying, as follows:

[0091] 70 parts of modified iron-based magnetic absorbent, 20 parts of epoxy resin, and 10 parts of polyamide curing agent were dispersed at 3000 rpm for 15 minutes using a stirring disperser, and then a certain amount of diluent was added to adjust the coating viscosity to 20-25 mPa·s, and stirring was continued at 3000 rpm for 15 minutes to obtain an absorbing coating.

[0092] The epoxy resin is a transparent viscous liquid, and is a product of Hubei Xinsihai Chemical Co., Ltd.

[0093] The polyamide curing agent is a medium-viscosity brown-yellow liquid, and is a product of Hubei Xinsihai Chemical Co., Ltd.

[0094] The diluent is prepared by mixing xylene and n-butanol in a mass ratio of 7:3. Both are colorless and transparent liquids and are products of Nanjing Hecheng Chemical Co., Ltd.

[0095] Subsequently, an absorbing coating with a thickness of 1 mm was prepared by compressed air spraying. The specific method is as follows: pour the coating into a W-71 spray gun, adjust the spraying pressure to 0.5 MPa, the spraying distance to 15-20 cm, the spray gun moving speed to 30-40 cm / s, and spray evenly on the surface of the substrate in an S-shaped path; after each 0.1 mm coating is sprayed, the sample is dried at room temperature for 10-15 minutes, and then the sample is placed in an oven and kept at 80°C for 12 hours to solidify the coating sprayed on the surface of the substrate, and the preparation process is repeated until the thickness of the obtained prefabricated layer reaches 1 mm.

[0096] In order to illustrate the absorption capacity of the prepared absorbing coating for electromagnetic waves, the reflection loss of the absorbing coating was tested by the bow method according to the GJB 2038-94 standard test. In order to verify the corrosion resistance of the absorbing coating, the absorbing coating was subjected to a 240h neutral salt spray test in accordance with the GJB150.11A-2009 standard, and then its absorbing performance was tested. The minimum reflection loss (RL min ) and effective absorption bandwidth (E A ) as shown in Table 2.

[0097] Table 2 Minimum reflection loss and effective absorption bandwidth of each embodiment and comparative example

[0098]

[0099] From the data in Table 2, it can be seen that the RL of the ferromagnetic absorbing coating in each embodiment is min Value and E A After 240 hours of salt spray treatment, the coating loss capacity of the comparative example decreased slightly, but the coating loss capacity of the comparative example decreased significantly, which proved that the modified iron-based magnetic absorber prepared in the embodiment can repair the damaged area, so that the ferromagnetic absorbing coating has excellent corrosion resistance. In short, the ferromagnetic absorbing coating with corrosion warning and suppression functions prepared in the embodiment of the present invention can well deal with the corrosion problem and effectively improve the use effect in harsh environments.

[0100] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing an iron-based magnetic absorbent having corrosion warning and inhibition functions, characterized in that: The following steps are involved: Adding absorbent, silane coupling agent and ammonia water into a mixed solvent, mixing and reacting, and obtaining a dispersion of silane coupling agent surface treated absorbent; Adding 1,10-phenanthroline and / or 1,10-phenanthroline derivatives to the dispersion, stirring and mixing, and centrifugally drying to obtain a modified iron-based magnetic absorbent; Wherein, the mixed solvent is prepared from water and anhydrous ethanol.

2. The method for preparing the iron-based magnetic absorbent with corrosion warning and inhibition functions according to claim 1, characterized in that: The absorbent is one of carbonyl iron, iron-silicon-aluminum alloy, iron-silicon-chromium alloy, iron-silicon alloy, iron-aluminum-boron alloy or amorphous alloy, iron-boron-phosphorus alloy or amorphous alloy, iron-nickel alloy, iron-nickel-molybdenum alloy, iron-chromium-nickel alloy, iron-cobalt-chromium alloy, and iron-cobalt-nickel-chromium alloy; the absorbent is spherical or flaky in shape, with a particle size of 3-40 μm.

3. The method for preparing the iron-based magnetic absorbent with corrosion warning and inhibition functions according to claim 1, characterized in that: The silane coupling agent is one or more of KH-550, KH-560 and KH-792.

4. The method for preparing the iron-based magnetic absorbent with corrosion warning and inhibition functions according to claim 1, characterized in that: The mass ratio of the absorbent, the silane coupling agent and the ammonia water is (50-80):(5-30):(0.5-4).

5. The method for preparing the iron-based magnetic absorbent with corrosion warning and inhibition functions according to claim 1, characterized in that: The mass ratio of the 1,10-phenanthroline or 1,10-phenanthroline derivative to the absorbent is (5-10):(50-80).

6. The method for preparing the iron-based magnetic absorbent with corrosion early warning and inhibition functions according to claim 1, characterized in that: The 1,10-phenanthroline derivative is 1,10-phenanthroline-5-amine and / or 1,10-phenanthroline monohydrate.

7. The method for preparing the iron-based magnetic absorbent with corrosion warning and inhibition functions according to claim 1, characterized in that: The mixing reaction includes: stirring at 500-800 rpm and keeping warm at 60-80° C. for 3-6 hours; The stirring and mixing is performed at 500-800 rpm for 1-3 hours; the centrifugal drying is performed at 8000-10000 rpm for 5-10 minutes, and then drying is performed at 60-80° C. for 10-14 hours.

8. The method for preparing the iron-based magnetic absorbent with corrosion early warning and inhibition functions according to claim 1, characterized in that: The mass ratio of the anhydrous ethanol to water is 1:1-8.

9. An iron-based magnetic absorbent having corrosion warning and inhibition functions, obtained by the method according to any one of claims 1 to 8.

10. Use of the iron-based magnetic absorbent with corrosion warning and inhibition functions as claimed in claim 9 in electromagnetic absorption.

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