CN115058143A - Electromagnetic wave absorbent, preparation method thereof and method for preparing wave-absorbing coating by using electromagnetic wave absorbent - Google Patents
Electromagnetic wave absorbent, preparation method thereof and method for preparing wave-absorbing coating by using electromagnetic wave absorbent Download PDFInfo
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Abstract
An electromagnetic wave absorbent, a preparation method thereof and a method for preparing wave-absorbing coating by using the electromagnetic wave absorbent relate to the electromagnetic wave absorbent, the preparation method and the application thereof. The electromagnetic wave absorbent aims to solve the technical problem that the wave absorption efficiency of the existing electromagnetic wave absorbent in the X wave band is low. The electromagnetic wave absorbent is a graphene-supported cobalt-based compound, wherein the cobalt-based compound is Co 3 O 4 And Co 2 (OH) 3 A mixture of Cl. The preparation method comprises the following steps: preparing precursor solution from graphene and a cobalt system, putting the precursor solution into a high-pressure reaction kettle for reaction, and cleaning and drying the precursor solution to obtain the electromagnetic wave absorbent. The electromagnetic wave absorbent is used for preparing the wave-absorbing coating, the coated film can effectively absorb 7.5 GHz-9 GHz in an X waveband of electromagnetic waves within the range of 3mm of the film thickness to-10 dB, the adhesive force of the coating is 0 grade, the wave-absorbing coating is not layered after being placed for more than 10 days at normal temperature, and the coating is not solidified and kept in an environment at-40 ℃ and is keptGood flowing state, and can be used in the wave-absorbing field.
Description
Technical Field
The invention relates to an electromagnetic wave absorbent, a preparation method and application thereof.
Background
The application of the wave-absorbing coating can be traced to the second war period at the earliest time, and is mainly applied to the body of a fighter. Stealth fighters utilize the wave-absorbing coating on the surface to achieve stealth. The wave-absorbing coating is formed by dispersing powder (absorbent) with specific dielectric parameters in a matrix (binder). Generally, the matrix acts as a bond, strength and environmental resistance, and the absorber acts as an electromagnetic loss.
The wave absorbing performance of the absorbent is closely related to certain parameters of the absorbent, such as particle size, morphology, microstructure and chemical composition. The microstructure of the composite nano material has the characteristics of multilayer, multi-dimension and multi-component, and the unique effect generated among the characteristics causes the design and synthesis of the composite nano material to be widely concerned.
The existing Chinese patent with application number 201310562605.5 discloses a graphene/polyaniline/cobalt composite wave-absorbing material, which is composed of a film-forming material and an electromagnetic wave absorbent, wherein the film-forming material adopts paraffin, the electromagnetic wave absorbent adopts a graphene/polyaniline/cobalt ternary compound, and the mass ratio of the graphene/polyaniline/cobalt compound to the paraffin is 1: 1. The electromagnetic wave absorbent has low wave absorbing range and wave absorbing efficiency, and particularly has low wave absorbing efficiency in an X wave band.
Disclosure of Invention
The application aims to solve the technical problem that the wave absorbing efficiency of the existing electromagnetic wave absorbent in the X wave band is low, and provides an electromagnetic wave absorbent, a preparation method thereof and a method for preparing special absorbing coating by using the electromagnetic wave absorbent.
The electromagnetic wave absorbent is a graphene-supported cobalt-based compound, wherein the cobalt-based compound is Co 3 O 4 And Co 2 (OH) 3 A mixture of Cl;
further, Co 3 O 4 The loading amount of the graphene is 0.5-3% of the mass of the graphene.
Further, Co 2 (OH) 3 The Cl loading is 1-1.5% of the graphene mass.
The preparation method of the electromagnetic wave absorbent comprises the following steps:
firstly, uniformly mixing a solvent and water at the temperature of 50-60 ℃, then adding polyol and uniformly mixing, and finally adding a pH regulator to enable the pH of the solution to reach 7.5-8.5 to obtain a mixed solution;
secondly, adding graphene into the mixed solution, carrying out ultrasonic treatment for 30-60 min, and stirring for 30-40 min; then adding a cobalt system, and stirring for 100-120 min at the temperature of 50-60 ℃ to obtain a precursor solution;
thirdly, transferring the precursor solution into a high-pressure reaction kettle, heating to 180-220 ℃ at a heating rate of 4-5 ℃/min, keeping for 8-15 hours, and cooling to normal temperature to obtain a product mixed solution;
and fourthly, pouring out the supernatant in the product mixed solution, washing with absolute ethyl alcohol, then centrifugally separating out solid phase substances, and then drying in vacuum to obtain the electromagnetic wave absorbent.
Further, the solvent in step one is ethanol (EtOH), ethylene glycol, pentaerythritol, Ethylene Glycol (EG), 1, 2-propanediol (1,2-PG), 1, 4-Butanediol (BDO), 1, 6-Hexanediol (HD), neopentyl glycol (NPG), diethylene glycol (EG.), dipropylene glycol (I) (PG), or Trimethylolpropane (TMP).
Further, the polyol in the first step is polyethylene glycol (PEG), neopentyl glycol (NPG), dipropylene glycol (I) (PG).
Further, the pH regulator in step one is sodium hydroxide, potassium hydroxide or sodium carbonate.
Further, the volume ratio of the solvent to the water in the step one is 1: (1-1.2).
Further, the mass ratio of the water to the polyhydric alcohol in the step one is (10-12): 1.
furthermore, the cobalt compound in the second step is cobalt chloride hexahydrate, cobalt sesquioxide, cobalt sulfate, cobalt acetate tetrahydrate, cobalt chloride, cobalt hydroxide or cobalt nitrate.
Furthermore, the mass ratio of the graphene to the cobalt-based material in the second step is 1: (5-10).
Further, the ratio of the mass of the graphene to the volume of the mixed solution in the second step is 1 g: (10-15) mL.
Furthermore, the rotating speed of the centrifugal separation in the fourth step is 8000r/min, and the centrifugal time is 10-15 min.
Further, the vacuum drying in the fourth step is vacuum drying in a vacuum drying oven at 50-60 ℃ for 12-14 h.
The method for preparing the wave-absorbing coating by using the electromagnetic wave absorbent comprises the following steps:
firstly, preparing epoxy high-strength resin;
weighing epoxy high-strength resin, anti-sagging resin, a flatting agent, a defoaming agent, an adhesion promoter, a dispersing agent, a solvent I and an electromagnetic wave absorbent, adding the epoxy high-strength resin, the anti-sagging resin, the flatting agent, the defoaming agent, the adhesion promoter, the dispersing agent, the solvent I and the electromagnetic wave absorbent into a sand mill, adding quartz sand, and dispersing for 3-5 hours at a stirring speed of 1000-3000 r/min; taking out, filtering to remove quartz sand, and obtaining a special liquid wave-absorbing medium material;
adding a solvent II into the high-density black body fluid intermediate, adding a curing agent, placing on an oscillating mixer, and shaking and mixing at room temperature for 6-8 hours to obtain a special liquid wave-absorbing medium material;
and fourthly, adding the working medium material into a reduced pressure distillation system for distillation, removing the low boiling point solvent, and distilling until the viscosity is 500-1000 mPa & s to obtain the wave-absorbing coating.
Further, the epoxy high-strength resin in the first step is prepared as follows: building a set of reactor with a condensation reflux, an oil-water separator and a stirring device, sequentially adding benzoic acid, trimethylolpropane, phthalic anhydride, a catalyst and a solvent, heating to 150-200 ℃ under the stirring condition, and carrying out reflux reaction for 3-5 hours to obtain epoxy high-strength resin; wherein the catalyst is dimethyl selenium, bis (4-methoxyphenyl) selenium oxide or potassium selenate; the solvent is toluene, xylene or tetrahydrofuran. The molar ratio of formic acid, trimethylolpropane, phthalic anhydride and catalyst is 3: 3: 3: 2; the mass ratio of the amount of benzoic acid to the mass of the solvent is 1mol (300-400 g).
Further, the anti-sagging resin described in step two is Wacker SILRES HP 2000 or Blackerland L-6310.
Further, the leveling agent in the second step is BYK-333, BYK-350 or BYK-323.
Further, the antifoaming agent in the second step is BYK-060N, BYK-037 or BYK-055.
Further, the adhesion promoter described in step two is Dow Corning 6040, Wingchuang Delgaseitai LTW or Pasteur Loxanol MI 6735.
Further, the dispersant described in step two is basf Dispex CX 4240, BYK163 or BYK 110;
further, the solvent I in the second step is dipropylene glycol butyl ether, neopentyl glycol (NPG) or diethylene glycol (EG).
Furthermore, in the second step, the mass ratio of the epoxy high-strength resin, the anti-sagging resin, the flatting agent, the defoaming agent, the adhesion promoter, the dispersing agent, the solvent I and the electromagnetic wave absorbent is 1: (10-50): (1-5): (1-10): (1-10): (1-10): (1-10): (30-80).
Furthermore, the particle size of the quartz sand in the step two is 100-500 microns.
Furthermore, the adding amount of the quartz sand in the step two is 20-80% of the mass of the liquid.
Furthermore, the solvent II in the third step is propylene glycol monophenyl ether, diethylene glycol butyl ether or diethylene glycol ethyl ether.
Still further, the curing agent described in step three is CYD-593, CYD-594 or T31 curing agent.
Furthermore, the volume ratio of the high-density black body fluid to the solvent II in the third step is 1: (3-10).
Furthermore, the volume ratio of the high-density black body fluid to the curing agent in the third step is (2.8-3.2): 1.
furthermore, the temperature during distillation in the fourth step is 150-220 ℃, and the vacuum degree is 1000-50 Pa; under the condition, low-boiling-point molecules can be removed, and meanwhile, the proper viscosity of the wave-absorbing coating can be ensured, so that the drying process after the coating is coated is facilitated.
The invention has the beneficial effects that:
the electromagnetic wave absorbent is a graphene-supported cobalt-based compound, wherein the cobalt-based compound is Co 3 O 4 、 Co 2 (OH) 3 And (4) Cl. Preparation with the electromagnetic wave absorbentThe film prepared by coating the wave-absorbing coating can effectively absorb 7.5 GHz-9 GHz in the X wave band of electromagnetic waves within the range of 3mm of film thickness (-10 dB).
The wave-absorbing coating prepared by using the electromagnetic wave absorbent has the adhesive force of a coating layer of 0 grade, and the wave-absorbing coating can not be layered after being placed for more than 10 days at normal temperature, so that the stability is good. Does not solidify in an environment of-40 ℃ and has good flowing state.
The electromagnetic wave absorbent and the wave-absorbing coating prepared by the invention can be used in the field of wave absorption.
Drawings
FIG. 1 is a photograph of an electromagnetic wave absorbent prepared in example 1;
FIG. 2 is an XRD spectrum of the electromagnetic wave absorbent prepared in example 1;
FIG. 3 is a transmission electron micrograph of an electromagnetic wave absorbent prepared in example 1;
FIG. 4 is a high magnification transmission electron micrograph of the electromagnetic wave absorbent prepared in example 1;
FIG. 5 is a graph of the electromagnetic wave absorption performance of the wave-absorbing coating prepared in example 2;
FIG. 6 is a graph of the electromagnetic wave absorption performance of the wave-absorbing coating prepared in example 3;
FIG. 7 is a graph of the electromagnetic wave absorption performance of the wave-absorbing coating prepared in example 4;
FIG. 8 is a graph of the electromagnetic wave absorption performance of the wave-absorbing coating prepared in example 5;
FIG. 9 is a graph of the electromagnetic wave absorption performance of the wave-absorbing coating prepared in example 6;
FIG. 10 is a graph of the electromagnetic wave absorption performance of the wave-absorbing coating prepared in example 7;
FIG. 11 is a photograph of an adhesion test of the wave-absorbing coating prepared in example 2;
FIG. 12 is a photograph showing that the wave-absorbing coating prepared in examples 2, 3 and 4 is allowed to stand for 10 days;
FIG. 13 is a photograph showing the flowing state of the wave-absorbing coating prepared in example 2 at-40 ℃.
Detailed Description
The following examples are used to demonstrate the beneficial effects of the present invention.
Example 1: the preparation method of the electromagnetic wave absorbent of the embodiment is carried out according to the following steps:
firstly, uniformly mixing 36mL of ethanol (EtOH) and 6mL of water at the temperature of 60 ℃, then adding 3g of polyethylene glycol (PEG) and uniformly mixing, and finally adding NaOH to adjust the pH value of the solution to 8 to obtain a mixed solution;
secondly, adding 0.3g of graphene into the mixed solution, carrying out ultrasonic treatment for 40min, and stirring for 30 min; 0.3625g CoCl was then added 2 ·6H 2 O, stirring for 120min at the temperature of 60 ℃ to obtain a precursor solution;
thirdly, transferring the precursor solution into a high-pressure reaction kettle, heating to 180 ℃ at the heating rate of 4 ℃/min, keeping for 8 hours, and cooling to normal temperature to obtain a product mixed solution;
and fourthly, pouring out the supernatant in the product mixed solution, washing the supernatant by using 30mL of absolute ethyl alcohol, centrifuging the supernatant for 15min under the condition of 8000r/min, putting the separated solid phase substance into a vacuum drying box, and drying the solid phase substance for 12h under the vacuum condition at the temperature of 60 ℃ to obtain the electromagnetic wave absorbent.
The photograph of the electromagnetic wave absorber obtained in this example is a black block as shown in fig. 1.
The XRD spectrum of the electromagnetic wave absorbent obtained in this example is shown in fig. 2, and it can be seen from fig. 2 that the cobalt-based compound supported on graphene is Co 3 O 4 、Co 2 (OH) 3 A mixture of both Cl.
Transmission electron micrographs of the electromagnetic wave absorbent obtained in this example are shown in FIGS. 3 and 4, and Co is shown in FIGS. 3 and 4 3 O 4 、Co 2 (OH) 3 Cl particles are loaded on graphene, and Co is obtained through calculation 3 O 4 The loading of (b) was 0.3%; co 2 (OH) 3 The Cl loading was 0.5%.
Example 2: the method for preparing the wave-absorbing coating by using the electromagnetic wave absorbent prepared in the embodiment 1 comprises the following steps:
firstly, preparing epoxy high-strength resin: building a set of three-neck flask with a condensation reflux device, an oil-water separator and a stirring device, sequentially adding 0.3mol of benzoic acid, 0.3mol of trimethylolpropane, 0.3mol of phthalic anhydride, 0.2mol of catalyst dimethyl selenium and 100g of solvent toluene, slowly heating and stirring, heating to 180 ℃ for reflux reaction, gradually dissolving reactants in the reflux reaction process, changing the reaction solution from black (the color of the catalyst) to yellowish brown, and cooling to normal temperature after reflux reaction for 4 hours to obtain epoxy high-strength resin;
weighing 100g of epoxy high-strength resin, 1g of sagging prevention resin Wake SILRES HP 2000, 2 g of leveling agent BYK-333, 2 g of defoaming agent BYK-060N, 1.5 g of adhesion promoter Dow Corning 6040, 3g of dispersing agent Bassflex CX 4240, 10 g of dipropylene glycol butyl ether and 15 g of electromagnetic wave absorbent prepared in the embodiment 1, adding the mixture into a sand mill, adding 50 g of quartz sand with the particle size of 1mm, and dispersing for 4 hours under the condition that the stirring speed is 3000 r/min; taking out, filtering to remove quartz sand, and obtaining a special liquid wave-absorbing medium material;
adding 200mL of solvent trimethylene di-monophenyl ether into 100mL of special liquid wave-absorbing medium material, adding 30mL of curing agent CYD-593, placing on an oscillating mixer, and shaking and mixing for 8 hours at room temperature to obtain the special liquid wave-absorbing medium material;
and fourthly, adding the working medium material into a reduced pressure distillation system for distillation, carrying out reduced pressure distillation under the conditions that the vacuum degree is 100Pa and the temperature is 160 ℃, removing the low-boiling-point solvent, and distilling until the dynamic viscosity is 870mPa & s to obtain the wave-absorbing coating. The electromagnetic wave absorbent in the wave-absorbing coating of the embodiment is 20% by mass.
Example 3: the difference between this embodiment and embodiment 2 is that 30 g of the electromagnetic wave absorbent prepared in embodiment 1 is added in step two, and the other steps are the same as embodiment 2, and the mass percentage of the electromagnetic wave absorbent in the wave-absorbing coating of this embodiment is 15%.
Example 4: the difference between this example and example 2 is that 25g of the electromagnetic wave absorbent prepared in example 1 is added in the second step, and the other steps are the same as example 2, and the mass percentage of the electromagnetic wave absorbent in the wave-absorbing coating material in this example is 10%.
Example 5: the difference between this example and example 2 is that 20 g of the electromagnetic wave absorbent prepared in example 1 is added in the second step, and the other steps are the same as example 2, and the mass percentage of the electromagnetic wave absorbent in the wave-absorbing coating material in this example is 5%.
Example 6: the difference between this embodiment and embodiment 2 is that 50 g of the electromagnetic wave absorbent prepared in embodiment 1 is added in step two, and the other steps are the same as embodiment 2, and the mass percentage of the electromagnetic wave absorbent in the wave-absorbing coating of this embodiment is 25%.
Example 7: the difference between this embodiment and embodiment 2 is that 70 g of the electromagnetic wave absorbent prepared in embodiment 1 is added in step two, and the other steps are the same as embodiment 2, and the mass percentage of the electromagnetic wave absorbent in the wave-absorbing coating of this embodiment is 30%.
The density of the wave-absorbing coating prepared in example 2 was tested. According to the definition formula of the density: rho is m/V, a medical injector with accurate scales is adopted to extract a certain volume of special working medium material, and the total mass m of the injector and the special working medium material is weighed on a balance 1 Then a certain volume of special working medium material V is pushed out 1 Then weighing the total mass m of the injector and the special working medium material 2 The density of the special working medium material can be calculated as follows: ρ ═ m 1 -m 2 )/V 1 . The average value is taken over a number of measurements. The density of the wave-absorbing coating prepared in the embodiment 2 is 1.0401g/cm 3 Close to 1g/cm 3 。
The wave-absorbing coating prepared in the embodiment 2-7 is made into films with the thickness of 4.0mm, 3.5mm, 3.0mm, 2.5mm, 2.0mm, 1.5mm, 1.0mm and 0.5mm, then a vector network analyzer is used for analyzing the dielectric property and the electromagnetic property of the film material, the obtained electromagnetic wave absorption performance curve diagram is shown in figures 5-10, and then the relevant wave-absorbing performance is discussed. As can be seen from fig. 5 to 10, the following law can be obtained in the electromagnetic wave absorption performance curve corresponding to the electromagnetic wave absorbent content of 5%, 10%, 15%, 20%, 25%, and 30%: with the increase of the content of the absorbent, the left shift trend of the absorption peak is obvious; the content of the absorbent has little influence on the intensity of the absorbed electromagnetic waves; when the film thickness is different under the condition of the same absorbent content, the absorption peak is obviously shifted to the left along with the increase of the film thickness. When the content of the absorbent is 15%, 20%, 25% and 30%, the absorbent can effectively absorb (10 dB) 7.5 GHz-9 GHz in an electromagnetic wave X wave band within the range of 3mm of the film thickness, and can also show that the requirement of absorbing electromagnetic waves can be met when the content of the electromagnetic wave absorbent in the wave-absorbing coating is more than 15% by mass fraction.
The wave-absorbing coating prepared in example 2 is coated on a flat glass plate and cured, the surface adhesion performance of the wave-absorbing coating prepared in example 2 is tested, and a grating device adopting a grating knife adhesion method is used for testing the surface adhesion performance of the coating. The hundred-grid knife cuts and penetrates the coating in a grid pattern by using a tool with a certain specification, the adhesion degree of the coating to the base material is evaluated by evaluating the integrity degree of the coating in the grid, the adhesion degree is expressed by grade, the pattern after grid division is classified according to six grades, and the separation resistance of the coating from the base material is evaluated. The "levels" are classified as follows:
1) ISO class: 0, the edges of the cuts were completely smooth, without any flaking of the grid edges.
2) ISO class: 1, small pieces are peeled off at the intersection of the cuts, and the actual damage in the grid-divided area is not more than 5%.
3) ISO class: 2, the edges and/or intersections of the cuts are peeled off, and the area of the cuts is more than 5 percent but less than 15 percent.
4) ISO class: 3, partial peeling or whole peeling or partial cell peeling is carried out along the edge of the cut. The area peeled off was more than 15% but less than 35%.
5) ISO class: 4, the edge of the cut is largely peeled off and/or some squares are partially or totally peeled off, and the area of the cut is more than 35% of the area of the grid area but not more than 65%.
6) ISO class: 5, ASTM grade: 0B exceeds the previous level.
The film before the crosshatch and before the crosshatch was shown in fig. 11 (a), and the film after the crosshatch was shown in fig. 11 (b), and it can be seen from fig. 11 (b) that the edges of the mouth were completely smooth and the edges of the crosshatch did not peel off after the hundred-grid knife test, and they were 0 grade, and they were the coating materials having the best adhesion.
The wave-absorbing coatings prepared in examples 2, 3 and 4 were placed in glass test tubes, respectively, and the uniformity of the coating in the test tubes was observed by standing (mainly to observe whether delamination occurred). The photograph after the standing time reaches 10 days is shown in fig. 12, wherein a is the wave-absorbing coating with the electromagnetic wave absorbent content of 10% by mass prepared in example 4, b is the wave-absorbing coating with the electromagnetic wave absorbent content of 15% by mass prepared in example 3, and c is the wave-absorbing coating with the electromagnetic wave absorbent content of 20% by mass prepared in example 2, as can be seen from fig. 12, the electromagnetic wave absorbent has good dispersion performance, and no delamination occurs after the standing time reaches more than 10 days, the mixing is very uniform, and the stable state can be maintained for a long time. This is because the electromagnetic wave absorber is dispersed completely and effectively at the initial stage of dispersion when stirred for 6 hours or more using dipropylene glycol butyl ether as a diluting solvent.
The wave-absorbing coating prepared in the embodiment 2 is subjected to ultralow temperature flow dynamic inspection, and the specific method is that the wave-absorbing coating is filled into a glass bottle, then the glass bottle is placed into a freezer, the temperature is adjusted to-40 ℃ and kept for 100 minutes, and whether the wave-absorbing coating is solidified or in a flowing state after 10 minutes is observed, wherein a is a photograph of the glass bottle placed vertically, and b is a photograph of the glass bottle placed obliquely, as shown in a field diagram 13. As can be seen from FIG. 13, no solidification occurs at a low temperature of-40 ℃, which is related to the physical properties of the solvent, the freezing point of the solvent dipropylene glycol butyl ether is-70 ℃, and although the viscosity of the resin material adopted in the high-density blackbody material is high at a low temperature, the whole solidification point of the special working medium material is reduced by the dilution of the solvent dipropylene glycol butyl ether.
Claims (10)
1. An electromagnetic wave absorbent is characterized in that the electromagnetic wave absorbent is a graphene-supported cobalt-based compound, wherein the cobalt-based compound is Co 3 O 4 And Co 2 (OH) 3 A mixture of Cl.
2. A method for preparing an electromagnetic wave absorbent according to claim 1, characterized in that the method is carried out by the steps of:
firstly, uniformly mixing a solvent and water at the temperature of 50-60 ℃, then adding polyol and uniformly mixing, and finally adding a pH regulator to enable the pH of the solution to reach 7.5-8.5 to obtain a mixed solution;
secondly, adding graphene into the mixed solution, carrying out ultrasonic treatment for 30-60 min, and stirring for 30-40 min; then adding a cobalt material, and stirring for 100-120 min at the temperature of 50-60 ℃ to obtain a precursor solution;
thirdly, transferring the precursor solution into a high-pressure reaction kettle, heating to 180-220 ℃ at a heating rate of 4-5 ℃/min, keeping for 8-15 hours, and cooling to normal temperature to obtain a product mixed solution;
and fourthly, pouring out supernatant in the product mixed solution, washing the supernatant with absolute ethyl alcohol, then centrifugally separating out solid phase substances, and drying the solid phase substances in vacuum to obtain the electromagnetic wave absorbent.
3. The method for preparing an electromagnetic wave absorbent according to claim 2, wherein the solvent in the first step is ethanol, ethylene glycol, pentaerythritol, ethylene glycol, 2-propanediol, 1, 4-butanediol, 1, 6-hexanediol, neopentyl glycol, diethylene glycol, dipropylene glycol, or trimethylolpropane.
4. The method for preparing an electromagnetic wave absorbent according to claim 2 or 3, wherein the polyol in the first step is polyethylene glycol, neopentyl glycol or dipropylene glycol.
5. The method according to claim 2 or 3, wherein the cobalt compound in step two is cobalt chloride hexahydrate, cobalt trioxide, cobalt sulfate, cobalt acetate tetrahydrate, cobalt chloride, cobalt hydroxide, or cobalt nitrate.
6. The method for preparing the wave-absorbing coating by using the electromagnetic wave absorbent as claimed in claim 1, which is characterized by comprising the following steps:
firstly, preparing epoxy high-strength resin;
weighing epoxy high-strength resin, anti-sagging resin, a flatting agent, a defoaming agent, an adhesion promoter, a dispersing agent, a solvent I and an electromagnetic wave absorbent, adding the epoxy high-strength resin, the anti-sagging resin, the flatting agent, the defoaming agent, the adhesion promoter, the dispersing agent, the solvent I and the electromagnetic wave absorbent into a sand mill, adding quartz sand, and dispersing for 3-5 hours at a stirring speed of 1000-3000 r/min; taking out, filtering to remove quartz sand, and obtaining a special liquid wave-absorbing medium material;
adding a solvent II into the high-density black body fluid intermediate, adding a curing agent, placing on an oscillating mixer, and shaking and mixing at room temperature for 6-8 hours to obtain a special liquid wave-absorbing medium material;
and fourthly, adding the working medium material into a reduced pressure distillation system for distillation, removing the low boiling point solvent, and distilling until the viscosity is 500-1000 mPa & s to obtain the wave-absorbing coating.
7. The method for preparing the wave-absorbing coating according to claim 6, wherein the method for preparing the epoxy high-strength resin in the first step comprises the following steps: building a set of reactor with a condensation reflux device, an oil-water separator and a stirring device, sequentially adding benzoic acid, trimethylolpropane, phthalic anhydride, a catalyst and a solvent, heating to 150-200 ℃ under the stirring condition, and carrying out reflux reaction for 3-5 hours to obtain epoxy high-strength resin; wherein the catalyst is dimethyl selenium, bis (4-methoxyphenyl) selenium oxide or potassium selenate; the solvent is toluene, xylene or tetrahydrofuran.
8. The method for preparing the wave absorbing coating according to claim 6 or 7, wherein the solvent I in the second step is dipropylene glycol butyl ether, neopentyl glycol or diethylene glycol.
9. The preparation method of the wave-absorbing coating according to claim 6 or 7, wherein in the second step, the mass ratio of the epoxy high-strength resin, the anti-sagging resin, the leveling agent, the antifoaming agent, the adhesion promoter, the dispersing agent, the solvent I and the electromagnetic wave absorbent is 1: (10-50): (1-5): (1-10): (1-10): (1-10): (1-10): (30-80).
10. The method for preparing the wave absorbing coating according to claim 6 or 7, characterized in that the solvent II in the step three is propylene glycol monophenyl ether, diethylene glycol butyl ether or diethylene glycol ethyl ether.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104263317A (en) * | 2014-09-26 | 2015-01-07 | 厦门大学 | Method for synthesizing cobalt oxide/graphene composite wave-absorbing material |
| CN105670560A (en) * | 2016-01-08 | 2016-06-15 | 北京科技大学 | Preparation method of nano-cobalt oxide/graphene composite wave-absorbing coating |
| CN107626931A (en) * | 2017-09-12 | 2018-01-26 | 四川大学 | The preparation and application of a kind of cobalt graphene composite material of electromagnetic wave absorption |
| US10975249B1 (en) * | 2019-10-11 | 2021-04-13 | Roham Rafiee | Nanocomposite coating for antenna reflector and methods of making same |
-
2022
- 2022-05-24 CN CN202210568982.9A patent/CN115058143A/en not_active Withdrawn
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104263317A (en) * | 2014-09-26 | 2015-01-07 | 厦门大学 | Method for synthesizing cobalt oxide/graphene composite wave-absorbing material |
| CN105670560A (en) * | 2016-01-08 | 2016-06-15 | 北京科技大学 | Preparation method of nano-cobalt oxide/graphene composite wave-absorbing coating |
| CN107626931A (en) * | 2017-09-12 | 2018-01-26 | 四川大学 | The preparation and application of a kind of cobalt graphene composite material of electromagnetic wave absorption |
| US10975249B1 (en) * | 2019-10-11 | 2021-04-13 | Roham Rafiee | Nanocomposite coating for antenna reflector and methods of making same |
Non-Patent Citations (1)
| Title |
|---|
| XIAOLU ZHAO等: "Graphene decorated by Co2(OH)3Cl: A promising lightweight wideband microwave absorber", 《JOURNAL OF ALLOYS AND COMPOUNDS》 * |
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