Multi-loss mechanism electromagnetic functional honeycomb core material and preparation method thereof

Abstract

The invention relates to a multi-loss mechanism electromagnetic functional honeycomb core material and a preparation method thereof, and belongs to the technical field of functional materials. The multi-loss mechanism electromagnetic function honeycomb core material comprises a paper-based electromagnetic loss layer and a resin electromagnetic loss layer, the paper-based electromagnetic loss layer is an electromagnetic modified aramid paper honeycomb grid hole wall; and the resin electromagnetic loss layer is a resin layer impregnated on the hole wall of the electromagnetic modified aramid paper honeycomb.

Description

TECHNICAL FIELD

[0001] The application relates to a multi-loss mechanism electromagnetic functional honeycomb core material and a preparation method thereof, and belongs to the technical field of functional materials. BACKGROUND

[0002] The electromagnetic functional honeycomb core material is a typical structural and functional integrated material, has multiple functions such as electromagnetic loss and bearing, and also has excellent mechanical properties, high temperature resistance, corrosion resistance and aging resistance, and has been applied to electromagnetic stealth structural parts of a large number of weapons and equipment. The research on the material is a development trend of the application of the functional honeycomb core material. The relatively mature technical solutions of the electromagnetic functional honeycomb core material currently include an electromagnetic modified aramid paper honeycomb, an impregnated honeycomb and a filled honeycomb. The electromagnetic modified aramid paper honeycomb is prepared by mixing a functional component into paper pulp in a papermaking process of aramid paper, preparing aramid paper with electromagnetic loss function, and then preparing the aramid paper into a honeycomb. The impregnated honeycomb is obtained by impregnating a honeycomb core material with resin with electromagnetic loss function, and then curing the resin under specific temperature and time. The filled honeycomb is obtained by filling electromagnetic functional foam and electromagnetic functional aerogel into a honeycomb core material cell, so that the bearing and electromagnetic loss capacity of the honeycomb core material are realized. The currently widely used electromagnetic functional honeycomb structure is mainly aimed at 8GHz-18GHz, and the electromagnetic loss performance is poor in the low-frequency range below 8GHz. In order to realize the low-frequency performance, part of the high-frequency performance is sacrificed, and the application requirement of wide-frequency electromagnetic loss cannot be truly realized. SUMMARY

[0003] The application breaks the technical limitation that the low-frequency electromagnetic loss performance of the electromagnetic functional honeycomb needs to rely on a large load of high-magnetic filler and a large thickness of the honeycomb core material, and solves the technical problem that the electromagnetic functional honeycomb is difficult to realize the low-frequency wide-frequency electromagnetic loss performance under the conditions of low bulk density and low thickness through the matching design of the low-load electromagnetic filler and the multi-electromagnetic loss layer.

[0004] TECHNICAL SCHEME In a first aspect, a multi-loss mechanism electromagnetic functional honeycomb core material is provided, which comprises a paper-based electromagnetic loss layer and a resin electromagnetic loss layer. The paper-based electromagnetic loss layer is a honeycomb cell wall of electromagnetic modified aramid paper, and the resin electromagnetic loss layer is a resin layer impregnated on the honeycomb cell wall of the electromagnetic modified aramid paper.

[0005] In a second aspect, a preparation method of the multi-loss mechanism electromagnetic functional honeycomb core material is provided, and the method comprises the following steps. Step 1: electromagnetic loss resin preparation: one or more of an electric loss type filler, a magnetic loss type absorber and an electromagnetic loss composite type filler is blended with impregnated resin, a solvent is used to dilute the one or more of the electric loss type filler, the magnetic loss type absorber and the electromagnetic loss composite type filler to a certain viscosity, electromagnetic loss resin dispersion is carried out, and the filler is uniformly dispersed in the resin solution until the electromagnetic loss resin is prepared. Step 2, electromagnetic modified aramid paper honeycomb treatment: the electromagnetic modified aramid paper honeycomb is placed in an oven for drying treatment; Step 3, impregnation: the electromagnetic modified aramid paper honeycomb is soaked in the prepared electromagnetic loss resin; Step 4, purification: purification treatment is performed after each impregnation; Step 5, drying; Step 6, curing.

[0006] Further, the electric loss type filler is a carbon material, and the mass fraction in the impregnated resin is 5% to 30%; The magnetic loss type absorber is a magnetic metal, and the mass fraction in the impregnated resin is 5% to 30%; The electromagnetic loss composite type filler is a carbon material and a magnetic metal composite filler, and the weight ratio is 1:5 to 10:1, which can be adjusted according to the electromagnetic parameter requirements; The solvent is an organic solvent; The viscosity of the electromagnetic loss resin is 13s to 15s; The impregnated resin is one or more of a phenolic resin system and an epoxy resin system; The electromagnetic modified aramid paper honeycomb is an electromagnetic modified aramid paper honeycomb loaded with carbon fibers, carbon nanotubes or carbonyl iron, and the loading amount is 0.5% to 10%.

[0007] Further, the dispersion time of the electromagnetic loss resin is 4h to 10h, and the rotation speed is 400rmp to 1000rmp.

[0008] Further, the drying treatment temperature is 110℃±5℃, and the drying time is 2h.

[0009] Further, the impregnation lifting speed is 0.5mm / s to 3mm / s, the first impregnation is 10min, and then each impregnation is 2min; the impregnation times are related to the density of the multi-loss mechanism electromagnetic functional honeycomb core material.

[0010] Further, the purification treatment includes: The honeycomb L is placed vertically to the ground, the honeycomb cell is close to the air inlet of the purification equipment, the cell direction is parallel to the wind direction, the purification time is 6h to 10h, and the purification wind speed is 0.3m / s to 1.0m / s.

[0011] Further, the method further includes: Drying and weighing after purification is completed; If the density of the multi-loss mechanism electromagnetic functional honeycomb core material does not meet the standard, supplementary impregnation and supplementary purification are performed; each supplementary impregnation is 2min; the supplementary impregnation lifting speed is the same as the impregnation lifting speed; the supplementary purification and the purification parameters and methods are the same; If the standard is met, step 5 is performed; Specifically, step five comprises: The honeycomb is dried by using an oven, the honeycomb L is placed vertically to the ground, the honeycomb cells are close to the air outlet of the oven, and the cell direction is parallel to the wind direction; the drying process is 60 DEG C * 0.5h + 85 DEG C * 1h + 100 DEG C * 1h, the constant temperature deviation is ± 5 DEG C, and the natural cooling to 60 DEG C or below can be taken out.

[0012] Further, the curing system is: 115 DEG C * 1h + 155 DEG C * 2h + 180 DEG C * 1.5h, the heating rate is less than or equal to 1 DEG C / min, and the curing is completed after natural cooling to 60 DEG C.

[0013] Beneficial effects: The synergistic mechanism of the paper-based electromagnetic loss layer and the resin electromagnetic loss layer is established, the air layer-resin electromagnetic loss layer-paper-based electromagnetic loss layer forms a gradient of electromagnetic parameters, the optimal balance of the electromagnetic matching characteristics and the attenuation characteristics of the electromagnetic functional honeycomb is achieved, the electromagnetic wave can be incident on the air layer-resin electromagnetic loss layer-paper-based electromagnetic loss layer and the synergistic loss of the double electromagnetic loss layer, the functional bandwidth of the electromagnetic functional honeycomb is expanded on the premise of maintaining the low electromagnetic loss material load of the honeycomb.

[0014] The application provides an electromagnetic functional honeycomb with resin and paper-based electromagnetic loss layers, which can realize synergistic loss mechanism of electric loss, magnetic loss and multiple interface scattering loss between layers, the electromagnetic performance of the electromagnetic functional honeycomb is adjusted by adjusting the types and adding amounts of fillers, and the low-frequency electromagnetic loss performance is expanded. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 It is a schematic diagram of the preparation method of the electromagnetic functional honeycomb core material.

[0016] Figure 2 It is a preparation process flow chart.

[0017] Figure 3 It is a physical diagram of the double electromagnetic loss layer wave-absorbing honeycomb.

[0018] Figure 4 It is a comparison diagram of the HH polarization loss curves of the multi-loss mechanism electromagnetic functional honeycomb core material and the ordinary electromagnetic modified aramid paper honeycomb.

[0019] Figure 5 It is a comparison diagram of the VV polarization loss curves of the multi-loss mechanism electromagnetic functional honeycomb core material and the ordinary electromagnetic modified aramid paper honeycomb. DETAILED DESCRIPTION

[0020] The application provides a multi-loss mechanism electromagnetic functional honeycomb core material and a preparation method thereof. Figures 1-2 The method comprises the following steps: Step 1, electromagnetic loss resin preparation: according to the mass fraction, the electric loss filler, the magnetic loss filler, and one or more of the electromagnetic loss composite filler are blended with the impregnated resin. The solvent is used to dilute it to a certain viscosity. The electromagnetic loss resin is dispersed by a high-speed disperser for a certain time and speed until the filler is uniformly dispersed in the resin solution. The electromagnetic loss resin is prepared.

[0021] The electric loss filler is preferably conductive carbon black, activated carbon, graphene, and other carbon materials, which are 5% to 30% in mass fraction in the absorbing resin.

[0022] The magnetic loss filler is preferably carbonyl iron, ferrite, and other magnetic metals, which are 5% to 30% in mass fraction in the absorbing resin.

[0023] The electromagnetic loss composite filler is preferably a carbon material and a magnetic metal composite filler, with a ratio of 1:5 to 10:1, which can be adjusted according to the electromagnetic parameter requirements.

[0024] The solvent is preferably anhydrous ethanol, acetone, and other organic solvents.

[0025] The impregnated resin is preferably a phenolic resin, epoxy resin, and other resin systems.

[0026] The viscosity of the electromagnetic loss resin is preferably 13s to 15s.

[0027] The dispersion time is preferably 4h to 10h. The dispersion speed is preferably 400rmp to 1000rmp.

[0028] Step 2, electromagnetic modified aramid paper honeycomb treatment: the electromagnetic modified aramid paper honeycomb is placed in an oven for drying treatment, the treatment temperature is 110℃±5℃, the drying time is 2h, and the honeycomb is taken out after cooling to room temperature.

[0029] The electromagnetic modified aramid paper honeycomb is preferably loaded with carbon fiber, carbon nanotube, or carbonyl iron, with a loading amount of 0.5% to 10%.

[0030] Step 3, impregnation: the honeycomb is impregnated by a rubber dipping machine, the electromagnetic modified aramid paper honeycomb is soaked in the prepared electromagnetic loss resin, the impregnation lifting speed is 0.5mm / s to 3mm / s, the first impregnation is 10min, and then each impregnation is 2min, and the purification treatment is carried out after impregnation.

[0031] Step 4, purification: after each impregnation, the purification equipment is used for purification treatment, the honeycomb L is placed vertically to the ground, the honeycomb grid hole is close to the equipment air inlet, the grid hole direction is parallel to the wind direction, the purification time is 6h to 10h, and the purification wind speed is 0.3m / s to 1.0m / s.

[0032] Step 5, drying: After purification, the weight is dried, if the density is not up to standard, the immersion is supplemented, steps 3~5 are repeated until the density reaches the specification. The honeycomb is dried in an oven, the honeycomb L is placed vertically to the ground, the honeycomb cells are close to the air outlet of the oven, and the cell direction is parallel to the wind direction. The drying process is 60℃x0.5h+85℃x1h+100℃x1h, the constant temperature deviation is ±5℃, and the natural cooling to 60℃ or below can be taken out.

[0033] Step 6, curing: the honeycomb is cured in an oven: when curing, the honeycomb L is placed vertically to the ground, the honeycomb cells are close to the air outlet of the oven, and the cell direction is parallel to the wind direction. The honeycomb curing process is 115℃x1h+155℃x2h+180℃x1.5h, the heating rate is ≤1℃ / min, and the natural cooling to 60℃ after the curing is completed.

[0034] Example 1 Example 1, a multi-loss mechanism electromagnetic functional honeycomb core with a cell size of 3mm and a density of 80kg / m 3 and a preparation method thereof. It is realized by the following steps: Step 1, electromagnetic loss resin preparation: according to the addition proportion of 20% of activated carbon mass fraction, the activated carbon is blended with phenolic resin, and is diluted with anhydrous ethanol to a viscosity of 13s. The wave-absorbing resin is dispersed by a high-speed dispersing machine at a speed of 500rmp for 4h until the filler is uniformly dispersed in the resin solution to prepare the electromagnetic loss resin.

[0035] Step 2, electromagnetic modified aramid paper honeycomb treatment: the electromagnetic modified aramid paper honeycomb with a carbon fiber loading of 1.5% is placed in an oven for drying treatment, the treatment temperature is 110℃±5℃, and the drying time is 2h, and it is taken out after cooling to room temperature.

[0036] Step 3, impregnation: the honeycomb is impregnated by a glue dipping machine, the electromagnetic modified aramid paper honeycomb is soaked in the prepared electromagnetic loss resin, the impregnation lifting speed is 2mm / s, the first impregnation is 10min, and then every 2min, and the purification treatment is carried out after impregnation.

[0037] Step 4, purification: after each impregnation, the purification equipment is used for purification treatment, the honeycomb L is placed vertically to the ground, the honeycomb cells are close to the air inlet of the equipment, and the cell direction is parallel to the wind direction, the purification time is 8h, and the purification wind speed is 0.5m / s.

[0038] Step 5, drying: After the purification is completed, the weight is dried, if the density is not up to standard, the immersion is supplemented, and steps 3~5 are repeated until the density reaches the specification. The honeycomb is dried in an oven, the honeycomb L is placed perpendicular to the ground, the honeycomb cells are close to the air outlet of the oven, and the cell direction is parallel to the wind direction. The drying process is 60℃×0.5h+85℃×1h+100℃×1h, the constant temperature deviation is ±5℃, and the natural cooling to 60℃ or below can be taken out.

[0039] Step 6, curing: when the bulk density reaches the requirement, the honeycomb is cured in an oven, if the bulk density does not reach the requirement. When curing, the honeycomb L is placed perpendicular to the ground, the honeycomb cells are close to the air outlet of the oven, and the cell direction is parallel to the wind direction. The honeycomb curing process is 115℃×1h+155℃×2h+180℃×1.5h, the heating rate is ≤1℃ / min, and the natural cooling to 60℃ after the curing is completed. After the curing is completed, the multi-loss mechanism electromagnetic function honeycomb core material is obtained, the physical diagram is shown in Figure 3 , the reflection loss curve is shown in Figures 4-5 , and the perpendicular reflectivity contrast results are shown in Table 1.

[0040] Table 1

Claims

1. A multi-loss mechanism electromagnetic functional honeycomb core, characterized by, Comprise: A paper-based electromagnetic loss layer and a resin electromagnetic loss layer; The paper-based electromagnetic loss layer is an electromagnetic modified aramid paper honeycomb grid hole wall; The resin electromagnetic loss layer is a resin layer impregnated on the electromagnetic modified aramid paper honeycomb grid hole wall.

2. A method of making a multi-loss mechanism electromagnetic functional honeycomb core according to claim 1, characterized in that, Comprise: Step 1, electromagnetic loss resin preparation: one or more of the electric loss type filler, the magnetic loss type absorber, and the electromagnetic loss composite type filler are blended with the impregnating resin, a solvent is used to dilute them to a certain viscosity, electromagnetic loss resin dispersion is carried out, and the filler is uniformly dispersed in the resin solution until the filler is uniformly dispersed in the resin solution, and the electromagnetic loss resin is prepared; Step 2, electromagnetic modified aramid paper honeycomb processing: the electromagnetic modified aramid paper honeycomb is placed in an oven for drying treatment; Step 3, impregnation: the electromagnetic modified aramid paper honeycomb is soaked in the prepared electromagnetic loss resin; Step 4, purification: purification treatment is carried out after each impregnation; Step 5, drying; Step 6, curing.

3. The method of claim 2, wherein, The electric loss type filler is a carbon material, and the mass fraction in the impregnating resin is 5%~30%; The magnetic loss type absorber is a magnetic metal, and the mass fraction in the impregnating resin is 5%~30%; The electromagnetic loss composite type filler is a carbon material and a magnetic metal compounded filler, and the weight ratio is 1:5~10:1, which can be adjusted according to the electromagnetic parameter requirements; The solvent is an organic solvent; The impregnating resin is one or more of a phenolic resin system and an epoxy resin system; The viscosity range of the electromagnetic loss resin is 13s~15s; The electromagnetic modified aramid paper honeycomb selects an electromagnetic modified aramid paper honeycomb loaded with carbon fiber, carbon nanotube or carbonyl iron, and the loading amount is 0.5%~10%.

4. The method of claim 2, wherein, The electromagnetic loss resin dispersion time is 4h~10h, and the rotation speed is 400rmp~1000rmp.

5. The method of claim 2, wherein, The drying treatment temperature is 110℃±5℃, and the drying time is 2h.

6. The method of claim 2, wherein, The impregnation lifting speed is 0.5mm / s~3mm / s, the first impregnation is 10min, and each subsequent impregnation is 2min; the impregnation times are related to the density of the multi-loss mechanism electromagnetic functional honeycomb core material.

7. The method of claim 2, wherein, The purification treatment includes: The honeycomb L is placed vertically to the ground, the honeycomb grid hole is close to the purification equipment air inlet, the grid hole direction is parallel to the wind direction, the purification time is 6h~10h, and the purification wind speed is 0.3m / s~1.0m / s.

8. The method of claim 2, wherein, The method further comprises: Drying and weighing after purification is completed; If the density of the multi-loss mechanism electromagnetic functional honeycomb core material does not meet the standard, supplementary impregnation and supplementary purification are carried out; each supplementary impregnation is 2min; the supplementary impregnation lifting speed is the same as the impregnation lifting speed; the supplementary purification and the purification parameters and methods are the same; If the standard is met, step 5 is executed; Specifically, step five comprises: An oven is used to dry the honeycomb, the honeycomb L is placed vertically to the ground, the honeycomb hole is close to the air outlet of the oven, and the grid hole direction is parallel to the wind direction; the drying process is 60℃×0.5h+85℃×1h+100℃×1h, the constant temperature temperature deviation is ±5℃, and the natural cooling to below 60℃ can be taken out.

9. The method of claim 2, wherein, The curing system is: 115℃×1h+155℃×2h+180℃×1.5h, the heating rate is ≤1℃ / min, and the curing is completed after natural cooling to 60℃.

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