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RU2674193 -- POLYMER COMPOSITION FOR
ABSORPTION OF HIGH-FREQUENCY ENERGY
CN108129758 -- P wave band traveling
wave inhibiting sheet material
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RU2012111336 -- POLYMER COMPOSITION
FOR ABSORBING HIGH-FREQUENCY ENERGY
POLYMER COMPOSITION FOR ABSORPTION OF
HIGH-FREQUENCY ENERGY
RU2674193
FIELD: radio equipment; electronics.SUBSTANCE: invention relates
to electronic equipment, in particular the production of polymer
compositions, designed to absorb the energy of parasitic types of
waves in the chart-forming devices of the quasi-optical type of
multibeam antenna arrays made on foil microwave fluoropolymer
based dielectrics. Polymer composition for absorption of
high-frequency energy contains polymer - synthetic rubber of low
molecular weight dimethylsiloxane SKTN 15-25 parts by weight, cold
curing catalyst K-68 0.4-0.6 parts by weight, absorbing filler -
carbonyl carbon iron radio of R-10 grade 34-56 parts by weight and
ethyl silicate-40 1.5 to 2.5 parts by weight.EFFECT: invention
provides a good level of coordination of the transition from the
foiled microwave dielectric to the polymer composition.1 cl, 2
tbl, 3 ex
The invention relates to electronic equipment, in particular the
production of polymer compositions intended to absorb the energy
of parasitic types of waves in the chart-forming devices of the
quasi-optical type of multibeam antenna arrays made on foil
microwave fluoroplast-based dielectrics.
Known "Composition for the absorption of high-frequency energy"
[RU 2349615 C1, publ. 20.09.2009 , IPC C09D 5/32]. The essence of
this invention is that it contains a polymer - synthetic rubber,
heat-resistant low molecular weight SKTN, cold-curing catalyst
K-68, as well as an absorbent filler - iron carbonyl radio grade
R-10 in the following ratio of components, May. including:
Synthetic heat-resistant synthetic rubber low molecular weight
SKTN 15-25 Cold-curing catalyst ?-68 0.6-1.0 Radio-carbonyl iron
<tb > brand P-10 78-83
The composition for absorbing high-frequency energy of such a
composition is made by simply mixing the components and curing
them at room temperature.
However, this composition has a significant shrinkage after curing
and various climatic influences, insufficient absorbing
properties. Known "Polymer composition for the absorption of
high-frequency energy" [RU 2493186 C1, publ. 20.09.2013 year IPC
C09D 5/32] contains low molecular weight dimethylsiloxane SKTN as
a base, iron carbonyl radio engineering and cold curing catalyst
K-68 as an absorbing filler, in addition, it additionally contains
a solution of high-molecular-mass SKT in a polymethylsiloxane
liquid and tetraethoxysilane isomericyne isomers, and it also
contains a solution of high-molecular-mass SKT in a
polymethylsiloxane liquid and tetraethoxysilane and its
composition. , as well as polyethylene polyamine as a curing rate
regulator in the following ratio of components, wt. including:
Low molecular weight dimethylsiloxane rubber SKTN 13-20 Rubber 2-3
Tetraethoxysilane or its derivatives selected from from ethyl
silicate-40 and ethyl silicate -32 2-3 Iron carbonyl radio
engineering P-10 78-90 Cold-curing catalyst K-68 1.0-1.5
Polyethylene polyamine to 1.0 Polymethylsiloxane liquid selected
by from PMS-50 and PMS-100 2-3
The method of obtaining the composition consists in the fact that
iron carbonyl radio engineering is pre-combined with rubber with
low molecular weight dimethylsiloxane SKTN, part of
polymethylsiloxane fluid, part of tetraethoxysilane or its
derivatives in component A, and is kept after mixing for at least
24 hours. its derivatives in component B, incubated after mixing
to a homogeneous state for at least 24 hours, and then mixed with
component A, add catalyst K-68 or its mixture with polyethylene
polyamine followed by curing.
However, this composition is multicomponent, laborious (more than
24 hours to prepare and 24 hours to cure) and does not provide the
required attenuation of the electromagnetic wave of the microwave
range.
The closest in technical essence to the proposed polymer
composition is a "Polymer composition for the absorption of
high-frequency energy" [RU 2497851 C1, publ. 10.11.2013 MCP G08L].
Polymer composition for absorbing high-frequency energy,
containing polymer - synthetic rubber of low molecular weight
dimethylsiloxane SKTN, catalyst - cold curing catalyst ?68, and
also contains P-10 radio-carbonyl radio engineering grade 40 as
well as absorbing filler, with the following ratio of components ,
wt. including:
Synthetic low-molecular rubber dimethylsiloxane SKTN 15-25
Radio-carbonyl iron of the mark ?-10 105-175
Cold Curing Catalyst # 68 1.5-2,5
Ethyl silicate-40 1.5-2.5.
The disadvantage of the prototype is the high value of the
relative dielectric constant and, as a result, insufficient
coordination of the transition from the foiled dielectric to the
absorbing composition, which makes it impossible to use it for the
manufacture of plates for absorbing the energy of parasitic wave
types in devices based on fluoroplastic based foil .
The technical problem of the claimed invention is to improve the
properties of the absorbing material.
The technical result of the proposed invention is to obtain a
polymer composition that provides a good level of coordination of
the transition from the foiled microwave dielectric to the
absorbing composition, which is associated with a decrease in the
real part of the relative dielectric constant and reflection
coefficient at a normal incidence of a flat uniform
electromagnetic wave at the "insulator-absorber" interface .
The essence of the invention lies in the fact that the proposed
polymer composition for absorbing high-frequency energy contains
polymer - synthetic rubber of low molecular weight
dimethylsiloxane SKTN, and cold curing catalyst K-68, as well as
absorbing filler - iron carbonyl radio technical grade P-10 and
ethyl silicate-40.
New is the fact that they use the polymer composition in the
following ratio of components, in May. including:
Synthetic low-molecular rubber dimethylsiloxane SKTN GOST 13835-73
15-25 Radio-carbonyl iron of the mark ?-10 GOST 13610-79 34-56
Cold-curing catalyst ?68 TU 38.303-04-05-90 0.4-0.6 Ethyl
silicate-40 GOST 26371-84 1.5-2 ,5
The polymer composition for absorbing high-frequency energy is
made by simply mixing the components and curing at room
temperature.
Table 1 shows the compositions of the proposed composition for
absorption
high frequency energy.
[image]
The specified range of components is chosen due to the fact that
with a decrease in the amount of carbonyl carbon radio
engineering, the absorbing properties deteriorate, and with an
increase it is impossible to achieve the required level of
matching. With a decrease in the amount of cold curing catalyst
No. 68, the composition does not completely cure, and with an
increase, the viscosity quickly increases, the viability of the
composition decreases, and the electrophysical parameters
deteriorate due to the presence of unselected air bubbles.
Table 2 shows the results of comparative tests of the analogue and
the claimed polymer composition for the absorption of
high-frequency energy.
[image]
As can be seen from the data presented in table 2, the proposed
polymer composition for the absorption of high-frequency energy
has the advantages:
- a lower maximum value of the dielectric constant of the
absorbing composition in the frequency range 12-14 GHz ("8.4" vs.
"20");
- a lower maximum value of the power reflection coefficient at a
normal incidence of a flat homogeneous electromagnetic wave at the
interface "foil microwave fluoroplast-based dielectric - absorbing
composition" in the frequency range 12-14 GHz ("-12" vs. "-7.5" ).
P wave band traveling wave inhibiting sheet
material
CN108129758
Abstract The invention belongs to the technical field of
electromagnetic functional materials. The powder absorbent is
used, and the surface of the absorbent is coated to achieve high
microwave permeability, which imparts high traveling wave
attenuation in the P-band and increases the filling ratio in the
matrix material. The P-band traveling wave suppression sheet
according to the present invention is a vulcanized film containing
a sheet-like absorbent having a thickness of 3.5 to 10 mm, and the
material quality composition comprises at least 20 parts of a
sheet-like absorbent powder of 60 to 110 parts of a base rubber.
The P-band traveling wave suppression sheet according to the
present invention has high saturation magnetization, good weather
resistance, good insulation performance, and high magnetic
permeability in the microwave section. In the radar wave P-band
has high magnetic permeability and magnetic loss, the average
value of the traveling wave loss effect of the material of 3 to 10
mm thick in the frequency range of 300 MHz to 1000 MHz is greater
than -10 dB. Applicable to the field of electromagnetic
anti-interference, especially suitable for phased array radar.
P-band traveling wave suppression sheet
Technical field
The invention belongs to the technical field of electromagnetic
functional materials, and relates to anti-interference
electromagnetic material design technology, in particular to
P-band anti-interference technology.
Background technique
P-band as radar detection signal has many advantages: P-band can
detect stealth target; P-band atmospheric attenuation is small,
detection distance is far; P-band radar component has low process
difficulty and low power consumption.
The distance between the remote warning phased array radar
antennas is relatively close. When the two antenna arrays work at
the same time, due to the traveling wave, the antenna array will
interfere with each other, and there are electromagnetic
interference and electromagnetic compatibility problems, which
cannot work normally, which seriously affects the use efficiency
and system tasks of the radar. To solve this problem, there are
two schemes for suppressing traveling waves by electromagnetic
functional materials and expanding the dynamic range of the
receiver. Extending the dynamic range of the receiver requires
changes to the antenna design, replacement of some key components,
long development cycle, and huge research costs. The use of
electromagnetic functional materials does not require changes to
the antenna array. It is only necessary to lay the absorbing
material directly in the middle of the two antenna arrays, which
has a short development cycle and is easy to operate.
At present, domestic application bands for absorbing sheets are
mainly concentrated in the range of 1 to 18 GHz, which are used
for special parts of aircraft and missiles. There are no reports
and studies on sheets below 1 GHz, especially for P-bands for
absorbing.
Summary of the invention
The object of the present invention is to provide a patch-type
radar wave absorbing material, which solves the problem of mutual
interference between antennas in a phased array radar.
The object of the present invention is achieved by using a powder
absorbent and coating the surface of the absorbent to prevent the
absorbing material from forming a conductive network during the
preparation process, thereby achieving high microwave permeability
and imparting a high P-band. The traveling wave is attenuated
while increasing its filling ratio in the matrix material.
The P-band traveling wave suppression sheet according to the
present invention is a vulcanized film containing a sheet-like
absorbent having a thickness of 3.5 to 10 mm, and the material
quality composition includes at least:
Flaky absorbent powder 60~110 parts
Base rubber 20 parts
The sheet-like absorbent is one or more of SiO2 coated sheet-like
ferrosilicon, ferrite-coated sheet-like ferrosilicon, flaky
carbonyl iron, and SiO2-coated ultrafine iron powder; The base
compound is a free radical vulcanization system.
The P-band traveling wave suppression sheet according to the
present invention is a vulcanized film containing a sheet-like
absorbent, and the material quality composition comprises at
least:
Absorbent powder 75~100 parts
Base compound 20 parts.
The P-band traveling wave suppression sheet according to the
present invention is characterized in that the ferrosilicon has a
sheet diameter of 20 to 70 µm and a sheet diameter to thickness
ratio of 50:1 to 150:1.
The P-band traveling wave suppression sheet according to the
present invention is characterized in that the carbonyl iron sheet
has a diameter distribution of 10 to 50 µm and a sheet diameter to
thickness ratio of 40:1 to 100:1.
The P-band traveling wave suppression sheet according to the
present invention is characterized in that the ultrafine iron
powder has a particle size ranging from 1 to 10 µm and the
particle shape is a branch shape.
The P-band traveling wave suppression sheet according to the
present invention is characterized in that: the base rubber is a
kind of EPDM rubber, silicone rubber, acrylate rubber, urethane
rubber, and nitrile rubber.
The P-band traveling wave suppression sheet according to the
present invention is characterized in that the vulcanizing agent
is 2,4-dichlorobenzoyl peroxide, p-p-diaminodiphenylmethane or
poly-p-nitrosobenzene. One.
The P-band traveling wave suppression sheet according to the
present invention is characterized in that the base rubber further
comprises an accelerator and an antifungal agent.
The P-band traveling wave suppression sheet according to the
present invention is characterized in that the accelerator is one
of TMTD, TETD, TMTM, and DDTD.
The P-band traveling wave suppression sheet according to the
present invention is characterized in that the antifungal agent is
phenol.
A preparation method for preparing a P-band traveling wave
suppression sheet, comprising an absorbent coating, a rubber
compounding and kneading, a calendering and a hot pressing
vulcanization process, wherein the thickness of the rolled lower
sheet is between 1.5 and 3 mm The mixed film is stacked in
parallel and placed in a mold having a thickness of 3.5 to 10 mm,
100 to 160 ° C / 15 to 25 MPa, and vulcanized by heat pressing for
15 minutes to 30 minutes.
The P-band traveling wave suppression sheet according to the
present invention has high saturation magnetization, good weather
resistance, good insulation performance, and high magnetic
permeability in the microwave section. In the radar wave P-band
has high magnetic permeability and magnetic loss, the average
value of the traveling wave loss effect of the material of 3 to 10
mm thick in the frequency range of 300 MHz to 1000 MHz is greater
than -10 dB. Applicable to the field of electromagnetic
anti-interference, especially suitable for phased array radar.
Detailed ways
The embodiments of the present invention are described below by
way of specific specific examples, and those skilled in the art
can readily understand other advantages and effects of the present
invention from the disclosure of the present disclosure. The
present invention may be embodied or applied in various other
specific embodiments. The various details of the present invention
can be variously modified and changed without departing from the
spirit and scope of the invention.
The microstructure of the composite was observed by Zeiss field
emission scanning microscope. The particle size of the absorbing
agent powder was measured by Marlven 2000 laser particle size
analyzer. The magnetic permeability and dielectric constant of the
microwave section of the composite were measured by Agilent vector
network analyzer. The point frequency RCS value of the absorbing
sheet was tested using an Agilent microwave millimeter wave RCS
test system.
Embodiment 1
100 parts of flake silicon-aluminum powder (BNA-130) was mixed
with 200 parts of absolute ethanol, 4 parts of
3-aminopropyltriethoxysilane (APTES) coupling agent and deionized
water, and stirred at room temperature for 2 h. Thereafter, 12
parts of tetraethyl orthosilicate (TEOS) was added to the system,
and the mixture was stirred at 80 r/min in a water bath at 40 ° C
for 3 hours to obtain an SiO 2 insulating coating layer on the
surface of the absorbent powder particles. The coated powder was
rinsed with absolute ethanol for 4 to 5 times to remove the
unreacted organic matter, and dried at 60 ° C for 3 hours. The
dried powder was heat-treated at 500 ° C for 2 h in a nitrogen
atmosphere, and after cooling, a SiO 2 -coated
iron-silicon-aluminum composite absorbent powder was obtained.
20 parts of ethylene propylene diene monomer (Dow 4770P) was
placed in an open mill for mixing, the front roll was 85 ° C, and
the rear roll was 80 ° C. After the sheeting, 60 parts of the
SiO2-coated iron-silicon-aluminum composite absorbent powder
prepared above was added, and after mixing, 0.3 parts of
triethylenetetramine, 0.3 parts of promoter MZ, and 0.3 parts of
phenol were added, and the mixture was uniformly adjusted. The
roll film obtained from the lower sheet was 1.5 mm, and the 6
sheets of the mixed film were placed in a mold in parallel, 100 °
C / 15 MPa, and heat-pressed for 15 min to obtain a 3.5-m thick
P-band traveling wave suppression sheet.
3.5 The test results of magnetic permeability and dielectric
constant of the mm-band P-wave traveling wave suppression sheet in
the 450MHz to 650MHz band are shown in Table 1. The real and
imaginary parts of the magnetic permeability at 450MHz are 11.8
and 10.2, respectively. . The attenuation values of the traveling
wave of each frequency point are obtained by simulation
calculation as shown in Table 2.
Table 1
Frequency (MHz) 450 550 650 µ' 11.8 10.4 9.3 µ" 10.2 10.3 10.4 3'
9.8 9.9 9.9 3" 0.8 1.0 1.2
Table 2
[image]
Embodiment 2
20 parts of silicone rubber (Shin-Etsu KE9X1-U) was placed in an
open mill for mastication. After tableting, 100 parts of flaky
carbonyl iron (LDXB-100) was added, kneaded uniformly, and 0.15
parts of benzoyl peroxide was added. 0.15 parts of accelerator
TMTD and 0.1 part of phenol were kneaded uniformly, and the
thickness of the sheet was adjusted to obtain a mixed film of 3
mm.
Four pieces of the mixed film were placed in a mold, placed at 160
° C / 25 MPa, and vulcanized by hot pressing for 20 minutes to
obtain a 4.5-m thick P-band traveling wave suppression sheet.
The relative density of the sheet is 100%; in the range of 450MHz
to 650MHz, the test results of magnetic permeability and
dielectric constant are shown in Table 3; the real and imaginary
parts of the magnetic permeability at 450MHz are respectively For
9.6 and 8.2. The attenuation values of the traveling wave of each
frequency point are obtained by simulation calculation as shown in
Table 4.
table 3
Frequency (MHz) 450 550 650 µ' 9.6 8.8 7.9 µ" 8.2 8.3 9.2 3' 8.6
9.0 8.9 3" 0.9 0.9 1.1
Table 4
[image]
Embodiment 3
100 parts of sheet-like iron silicon aluminum (BNA-130) was mixed
with 200 parts of absolute ethanol, 4 parts of
3-aminopropyltriethoxysilane (APTES) coupling agent and deionized
water, and stirred at room temperature for 1 hour. To the system,
14 parts of tetraethyl orthosilicate (TEOS) was added and stirred
at 40 r/min in a water bath at 40 ° C for 3 h. The coated powder
was washed with anhydrous ethanol for 4 to 5 times, dried at 60 °
C for 4 hours, and heat-treated at 500 ° C for 1 hour in a
nitrogen atmosphere, and cooled to obtain a SiO 2 -coated
iron-silicon-aluminum composite absorbent powder.
The preparation method of the rubber compound is the same as that
of the second embodiment, and the thickness of the kneaded film is
2.5 mm. The material composition includes 20 parts of silicone
rubber (Shin-Etsu KE9X1-U), 75 parts of SiO2 coated
iron-silicon-aluminum composite absorbent powder, 0.25 parts of
2,4-dichlorobenzoyl peroxide, 0.25 parts of accelerator TMTD and
0.2 Parts of phenol.
Five sheets of green film were placed in a parallel stack in a
mold, 160 ° C / 20 MPa, and hot pressed for 20 min to obtain a 6
mm thick P-band traveling wave suppression sheet.
The test results of magnetic permeability and dielectric constant
in the 450MHz to 650MHz band are shown in Table 5 at room
temperature; the real and imaginary parts of the magnetic
permeability of 450MHz are 10.8 and 9.9, respectively. The
traveling wave attenuation values of each frequency point are
obtained by simulation calculation as shown in Table 6.
table 5
Frequency (MHz) 450 550 650 µ' 10.8 10.4 10.0 µ" 9.9 9.9 10.6 3'
9.6 10.0 9.5 3" 0.7 0.8 1.0
Table 6
[image]
Embodiment 4
This embodiment provides a method for preparing a P-band traveling
wave suppression material, which includes the following steps:
The preparation method of the rubber compound is the same as that
in the first embodiment, and the thickness of the kneaded film is
2 mm. The material composition included 20 parts of ethylene
propylene diene monomer (Dow 4770P), 90 parts of flaky carbonyl
iron (LDXB-100), 0.2 parts of triethylenetetramine, 0.2 parts of
promoter MZ and 0.1 parts of phenol.
Six sheets of green film were placed in a parallel stack in a
mold, 160 ° C / 20 MPa, and hot pressed for 20 min to obtain a 5
mm thick P-band traveling wave suppression sheet.
The samples were tested for performance. The test results of
magnetic permeability and dielectric constant in the range of 450
MHz to 650 MHz at room temperature are shown in Table 7. The real
and imaginary parts of the magnetic permeability of the sample at
450 MHz were 9.4 and 8.0, respectively. The attenuation values of
the traveling wave of each frequency point are obtained by
simulation calculation as shown in Table 8.
Table 7
Frequency (MHz) 450 550 650 µ' 9.4 8.7 8.0 µ" 8.0 8.3 9.3 3' 8.8
9.2 9.2 3" 1.0 1.0 1.1
Table 8
[image]
Embodiment 5
This embodiment provides a method for preparing a P-band traveling
wave suppression material, which includes the following steps:
(1)Sheet-shaped ferrosilicon-aluminum (BNA-130) coated ferrite
technology: 10 parts of manganese-zinc ferrite and 100 parts of
FeSiAl are selected, converted into the required molar mass of
manganese-zinc ferrite, according to Fe<3+>, A mixed nitrate
solution was prepared in a molar ratio of Zn<2+>,
Mn<2+> of 10:3:2. The FeSiAl powder was poured into the
Fe-Zn-Mn mixed nitrate solution, and a 2 mol/L NaOH solution was
slowly added dropwise under constant stirring to adjust the pH of
the solution to 9. The precipitate was added to an appropriate
amount of deionized water and transferred to a stainless steel
reaction vessel, and reacted at 160 ° C for 5 h. After the
reaction was completed, the prepared sample was first washed with
deionized water to remove residual nitrate ions and sodium ions.
Then, it was washed several times with absolute ethanol, and dried
in a drying oven at 80 ° C for 3 hours to obtain a composite
magnetic powder.
(2)The base was mixed with an absorbent: 20 parts of a urethane
rubber elastomer (BASF 1090A) was placed in an open mill and
kneaded at a temperature of 140 ° C for the front roll and 135 ° C
for the rear roll. After kneading into a sheet form, 85 parts of
the coated absorbent (1) are added, and after mixing, 0.2 parts of
p-diaminodiphenylmethane, 0.2 part of accelerator TETD and 0.2
part of phenol are added. Mix evenly and adjust the film thickness
to 2mm.
(3)The absorbing rubber sheet is hot-pressed and vulcanized: 7
pieces of (2) absorbing rubber sheets are placed in parallel in a
7.5 mm mold, placed in a hot press, set at a temperature of 130 °
C, a pressure of 15 MPa, and a heat pressurization for 15 minutes.
forming. Remove the film and cut out the desired size and shape.
The sample was tested for performance. The test results of
magnetic permeability and dielectric constant in the 450MHz to
650MHz band at room temperature are shown in Table 9. The real and
imaginary parts of the sample at 450 MHz have a real and imaginary
part of 12 and 10.9, respectively. The attenuation values of the
traveling wave of each frequency point are obtained by simulation
calculation as shown in Table 10.
Table 9
Frequency (MHz) 450 550 650 µ' 12.0 11.2 10.0 µ" 10.9 10.3 11.5 3'
9.2 9.0 9.1 3" 0.8 0.8 0.9
Table 10
[image]
Embodiment 6
This embodiment provides a method for preparing a P-band traveling
wave suppression material, which includes the following steps:
(1) Ferrous silicon aluminum (BNA-130) surface treatment coated
ferrite: 10 parts of manganese zinc ferrite and 100 parts of
FeSiAl are selected, converted to the required molar mass of
manganese zinc ferrite, according to Fe<3+>, Zn <2+>,
Mn<2+> molar ratio 10:4:3 configuration mixed nitrate
solution. The FeSiAl powder was poured into the Fe-Zn-Mn mixed
nitrate solution, and a 2 mol/L NaOH solution was slowly added
dropwise under constant stirring to adjust the pH of the solution
to 11. The precipitate was added to an appropriate amount of
deionized water and transferred to a stainless steel reaction
vessel, and reacted at 200 ° C for 7 h. After the reaction was
completed, the prepared sample was first washed with deionized
water to remove residual nitrate ions and sodium ions. Then, it
was washed several times with absolute ethanol, and dried in a
drying oven at 80 ° C for 3 hours to obtain a composite magnetic
powder.
(2)The base body is mixed with the absorbent: 20 parts of the
acrylate rubber elastic (AR840) body is placed in an open mill for
kneading, and the kneading temperature is: front roll temperature
80 ° C, rear roll temperature 75 ° C, to be kneaded After the
sheet is formed, (1) 45 parts of the absorbent and the flaky
carbonyl iron are added, and after mixing, 0.2 parts of
triethylenetetramine, 0.2 part of accelerator TMTM and 0.15 parts
of phenol are added, uniformly mixed, and the thickness is
adjusted. 2mm.
(3) The absorbing rubber sheet is hot-pressed and vulcanized: 7
pieces of the absorbing rubber sheets in (2) are placed in
parallel in a 9 mm mold, placed in a hot press, set at a
temperature of 90 ° C, a pressure of 20 MPa, and a heat-cured
vulcanization for 15 minutes. forming. Remove the film and cut out
the desired size and shape.
The samples were tested for performance. The test results of
magnetic permeability and dielectric constant in the 450 MHz to
650 MHz band at room temperature are shown in Table 11. The real
and imaginary parts of the magnetic permeability of the sample at
450 MHz were 11.4 and 10.4, respectively. The traveling wave
attenuation values of each frequency point are obtained by
simulation calculation as shown in Table 12.
Table 11
Frequency (MHz) 450 550 650 µ' 11.4 11.4 11.2 µ" 10.4 10.3 10.6 3'
8.6 9.0 8.8 3" 0.8 0.9 1.0
Table 12
[image]
Example 7
This embodiment provides a method for preparing a P-band traveling
wave suppression material, which includes the following steps:
(1) Ultrafine iron powder (JS-D01) surface treatment coated with
SiO2: 100 parts of ultrafine iron powder with 200 parts of
absolute ethanol, 6 parts of 3-aminopropyltriethoxysilane (APTES)
coupling agent and deionized After mixing at room temperature for
2 h, 14 parts of tetraethyl orthosilicate (TEOS) was added to the
system, and stirred at 40-800 r/min in a water bath at 40 ° C for
3 h, initially on the surface of the iron powder particles. A SiO2
insulating coating is obtained. The coated powder was rinsed with
absolute ethanol for 4 to 5 times to remove the unreacted organic
matter, and dried at 60 ° C for 4 hours. The dried powder was
heat-treated at 500 ° C for 2 h in a hydrogen atmosphere, and
after cooling, an ultrafine iron powder composite powder having a
uniform surface coated with SiO 2 was obtained.
(2) The preparation method of the rubber compound is the same as
that in the first embodiment, and the thickness of the kneaded
film is 2 mm. The material composition included 20 parts of
ethylene propylene diene monomer (Dow 4770P), 110 parts (1) of the
coated absorbent, 0.1 part of triethylenetetramine, 0.1 part of
promoter MZ and 0.1 part of phenol.
9 sheets of green film were placed in a parallel stack in a mold,
100 ° C / 25 MPa, and heat-pressed for 15 minutes to obtain a 10
mm thick P-band traveling wave suppression sheet.
The samples were tested for performance. The test results of
magnetic permeability and dielectric constant in the 450 MHz to
650 MHz band at room temperature are shown in Table 13. The real
and imaginary parts of the magnetic permeability of the sample at
450 MHz were 10.8 and 10.2, respectively. The attenuation values
of the traveling wave of each frequency point are obtained by
simulation calculation as shown in Table 14.
Table 13
Frequency (MHz) 450 550 650 µ' 10.8 10.2 10.6 µ" 10.2 10.5 10.7 3'
8.8 9.2 8.6 3" 1.0 1.1 0.9
Table 14
[image]
Example eight
This embodiment provides a method for preparing a P-band traveling
wave suppression material, which includes the following steps:
(1) Sheet-like ferrosilicon-aluminum (BNA-130) and ultra-fine iron
powder (JS-D01) surface-coated SiO2: 50 parts of sheet-like
ferrosilicon and 50 parts of ultrafine iron powder mixed absorbent
with 200 parts Water ethanol, 6 parts of
3-aminopropyltriethoxysilane (APTES) coupling agent and deionized
water were mixed. After stirring at room temperature for 1 h, 12
parts of tetraethyl orthosilicate (TEOS) was added to the system.
The mixture was stirred in a 40 ° C water bath for 3 h at a speed
of 500 to 800 r/min, and an SiO 2 insulating coating layer was
initially obtained on the surface of the iron powder particles.
The coated powder was rinsed with absolute ethanol for 4 to 5
times to remove the unreacted organic matter, and dried at 60 ° C
for 4 hours. The dried powder is heat-treated at 500 ° C for 1 h
in a hydrogen atmosphere, and after cooling, an ultrafine iron
powder composite powder having a uniform surface coated with SiO 2
is obtained.
(2) The preparation method of the rubber compound is the same as
that in the fifth embodiment, and the thickness of the kneaded
film is 3 mm. The material composition included 20 parts of
urethane rubber elastomer (BASF 1090A), 80 parts (1) of the mixed
absorbent, 0.2 parts of triethylenetetramine, 0.2 parts of
promoter MZ and 0.2 parts of phenol.
Four sheets of green film were placed in a parallel stack in a
mold, 160 ° C / 15 MPa, and hot pressed for 15 min to obtain a 7
mm thick P-band traveling wave suppression sheet.
The performance test of the sample is shown in Table 15 for the
magnetic permeability and dielectric constant in the 450 MHz to
650 MHz band at room temperature. The real and imaginary parts of
the magnetic permeability of the sample at 450 MHz were 11.8 and
10.7, respectively. The traveling wave attenuation values of each
frequency point are obtained by simulation calculation as shown in
Table 16.
Table 15
Frequency (MHz) 450 550 650 µ' 11.8 11.9 11.6 µ" 10.7 11.3 11.6 3'
7.8 7.6 7.9 3" 1.0 1.2 1.1
Table 16
[image]
Example nine
This embodiment provides a method for preparing a P-band traveling
wave suppression material, which includes the following steps:
(1) Ultrafine iron powder (JS-D01) surface treatment coated with
SiO2: 100 parts of ultrafine iron powder with 200 parts of
absolute ethanol, 3 parts of 3-aminopropyltriethoxysilane (APTES)
coupling agent and deionization After mixing at room temperature
for 1 h, 10 parts of tetraethyl orthosilicate (TEOS) was added to
the system, and stirred at 40-800 r/min in a water bath at 40 ° C
for 3 h, initially on the surface of the iron powder particles. A
SiO2 insulating coating is obtained. The coated powder was rinsed
with absolute ethanol for 4 to 5 times to remove the unreacted
organic matter, and dried at 60 ° C for 4 hours. The dried powder
is heat-treated at 500 ° C for 1 h in a hydrogen atmosphere, and
after cooling, an ultrafine iron powder composite powder having a
uniform surface coated with SiO 2 is obtained.
(2) The substrate was mixed with an absorbent: 20 parts of nitrile
rubber (JSR-N230SL) was placed in an open mill and kneaded at a
mixing temperature of 90 ° C for the front roll and 85 ° C for the
rear roll. After kneading into a sheet form, 95 parts of the
coated absorbent (1) is added, and after mixing, 0.25 parts of
poly-p-nitrosobenzene, 0.25 parts of accelerator TMTM, and 0.25
parts of phenol are added. Mix evenly and adjust the thickness to
2mm.
(3) The absorbing rubber sheet is hot-pressed and vulcanized: 6
sheets (2) of the absorbing rubber sheet are placed in a hot
press, and the temperature is set to 100 ° C, the pressure is 15
MPa, and the time is 15 minutes. Remove the film and cut out the
desired size and shape.
The performance of the sample was tested. The test results of
magnetic permeability and dielectric constant in the 450 MHz to
650 MHz band at room temperature are shown in Table 17. The real
and imaginary parts of the magnetic permeability of the sample at
450 MHz were 9.4 and 10.0, respectively. The traveling wave
attenuation values of each frequency point are obtained by
simulation calculation as shown in Table 18.
Table 17
Frequency (MHz) 450 550 650 µ' 9.4 10.4 10.2 µ" 10.0 10.0 10.2 3'
9.2 9.4 9.4 3" 0.9 0.0 0.9
Table 18
Tapered wave-absorbing material and
preparation method thereof
CN108084694
The invention discloses a tapered wave-absorbing material and a
preparation method thereof. The method comprises the following
steps: mixing polyurethane rubber, stearic acid, an antioxidant,
dicumylperoxide, a plasticizer and carbonyl iron powder in
proportion for blending evenly to obtain blended polyurethane
rubber; and pressing the blended polyurethane rubber in a
pyramidal mold to form the tapered wave-absorbing material. The
prepared tapered wave-absorbing material includes a plurality of
adjacent and repetitively-arranged square-pyramid pieces and is
added with the carbonyl iron powderas a wave absorber, so that the
prepared tapered wave-absorbing material has a good wide-band wave
absorbing performance and can realize a good wave absorbing
performance in a wide-band range from microwave to millimeter
wave, and by multiple reflections between wedges of the plurality
of square-pyramid pieces and conversion of energy of
electromagnetic waves into thermal energy by use of the wave
absorber for consumption, the tapered wave-absorbing material has
a good absorbing effect at specific wavelength bands. The tapered
wave-absorbing material can be applied to many fields such as
aerospace, high-speed locomotives, warships, radar antennas, and
electronics.
Abstract The invention discloses a cone absorbing material and a
preparation method thereof, the method comprising: mixing urethane
rubber, stearic acid, anti-aging agent, dicumyl peroxide,
plasticizer and carbonyl iron powder in proportion. Uniformly, a
urethane rubber is obtained; the urethane rubber is pressed and
formed in a pyramidal mold to obtain a tapered absorbing material.
The tapered energy absorbing material has a wide broadband
absorbing property due to the inclusion of a plurality of adjacent
and repeatedly arranged quadrangular pyramids and the addition of
the absorbing agent carbonyl iron powder, and can realize wide
frequency from microwave to millimeter wave. Good absorbing
properties in the range, and can be consumed by multiple
reflections between the tips of a plurality of quadrangular
pyramids and the absorption of electromagnetic waves by the
absorbing agent into thermal energy, and have good in specific
bands The absorbing effect. The tapered absorbing material of the
present invention can be applied to many fields such as aerospace,
high-speed locomotives, ships, radar antennas, and electronics.
Conical absorbing material and preparation method thereof
Technical field
The invention relates to the field of composite materials, in
particular to a cone absorbing material and a preparation method
thereof.
Background technique
Absorbing material is a type of material that absorbs the energy
of electromagnetic waves that are projected onto its surface. In
engineering applications, in addition to requiring the absorbing
material to have a high absorption rate for electromagnetic waves
in a wide frequency band, it is also required to have light
weight, temperature resistance, moisture resistance, corrosion
resistance and the like.
At present, patch-type materials generally have the disadvantage
of high surface density, and the temperature resistance is
generally lower than 100 ° C, which cannot meet the mechanical
properties of equipment such as aircraft. A microporous absorbing
material having an array structure surface developed, and some
materials are subjected to a microcellular foaming process during
vulcanization, and the obtained material has a small surface
density, but the absorbing agent used is micron. Conductive carbon
black, although conductive carbon black is used as a absorbing
agent on the one hand and as a reinforcing agent on the other
hand, the biggest disadvantage of using carbon black as an
absorbent is that the absorbing property is poor and cannot be
very good. Meet the absorbing requirements of cutting-edge
technical equipment such as ship equipment.
Based on this, an attempt was made to find an absorbing material
with better absorbing properties.
Summary of the invention
In view of the problems in the related art, the present invention
proposes a method for preparing a tapered absorbing material to
solve the problem of poor absorbing properties of the absorbing
material in the prior art.
According to one aspect of the present invention, there is
provided a method for preparing a tapered absorbing material
comprising: pressing a urethane rubber, a stearic acid, an
antioxidant, dicumyl peroxide, a plasticizer, and a carbonyl iron
powder The mixture is uniformly mixed and mixed to obtain a
urethane rubber which is densely mixed; the urethane rubber is
pressed and formed in a pyramidal mold to obtain a tapered
absorbing material.
In the above method, urethane rubber, stearic acid, antioxidant,
dicumyl peroxide, plasticizer and carbonyl iron powder are mixed
in proportion in an internal mixer and at a temperature of 65 to
85 °C. The step of mixing evenly.
In the above method, in the step of vulcanizing machine, a step of
press molding the dense urethane rubber in a pyramidal mold is
carried out.
In the above method, in press molding, vulcanization is carried
out at a temperature of 160 to 170 ° C, and the vulcanization time
is 25 to 30 min.
In the above method, 100 parts by weight of urethane rubber, 0.3
to 3 parts of stearic acid, 0.5 to 1.5 parts of an antioxidant,
1.5 to 3 parts of dicumyl peroxide, and 2 to 6 parts by mass. The
plasticizer and 50 to 80 parts of carbonyl iron powder are mixed
and mixed uniformly.
In the above method, the antioxidant includes one or a combination
of N-phenyl-a-aniline, N-phenyl-ß-naphthylamine,
N-phenyl-N'-cyclohexyl p-phenylenediamine.
In the above method, the plasticizer comprises one or a
combination of di-n-octyl phthalate, a benzene polyester,
diisobutyl phthalate, and dimethyl phthalate.
In the above method, the pyramid mold comprises a plurality of
adjacent and repeatedly arranged quadrangular pyramid holes, the
size of the pyramid mold is 330 mm × 330 mm, and the height of the
pyramid mold after removing the cone absorbing material is 22mm.
In the above method, the tapered absorbing material comprises a
plurality of adjacent and repeatedly arranged quadrangular
pyramids.
According to an aspect of the invention, there is provided a
tapered absorbing material prepared by the method of any one of
claims 1-9.
The tapered absorbing material provided by the invention comprises
a plurality of adjacent and repeatedly arranged quadrangular
pyramids and is added with a absorbing agent carbonyl iron powder,
so that the broadband absorbing property is good, and the
microwave to millimeter wave can be realized. Good absorbing
properties in a wide frequency range, and can be consumed by
multiple reflections between the tips of a plurality of
quadrangular pyramids and in which the absorbing agent converts
the energy of electromagnetic waves into heat energy, and has a
specific band Good absorbing effect. The tapered absorbing
material of the present invention can be applied to many fields
such as aerospace, high-speed locomotives, ships, radar antennas,
and electronics.
DRAWINGS
In order to more clearly illustrate the embodiments of the present
invention or the technical solutions in the prior art, the
drawings to be used in the embodiments will be briefly described
below. Obviously, the drawings in the following description are
only some of the present invention. For the embodiments, those
skilled in the art can obtain other drawings according to the
drawings without any creative work.
1 is a partial structural schematic view of a tapered absorbing
material according to an embodiment of the present invention.
Detailed ways
The technical solutions in the embodiments of the present
invention are clearly and completely described in the following
with reference to the accompanying drawings in the embodiments of
the present invention. It is obvious that the described
embodiments are only a part of the embodiments of the present
invention, but not all embodiments. All other embodiments obtained
by those of ordinary skill in the art based on the embodiments of
the present invention are within the scope of the present
invention.
Method for preparing a tapered absorbing material
Step 1: Polyurethane rubber, stearic acid, anti-aging agent,
dicumyl peroxide, plasticizer and carbonyl iron powder are mixed
and mixed in proportion to obtain a dense polyurethane rubber. In
a preferred embodiment, in this step, 100 parts by weight of
urethane rubber, 0.3 to 3 parts of stearic acid, 0.5 to 0.5 parts
by mass in an internal mixer and at a temperature of 65 to 85 °C.
1.5 parts of an antioxidant, 1.5 to 3 parts of dicumyl peroxide, 2
to 6 parts of a plasticizer, and 50 to 80 parts of carbonyl iron
powder are mixed and uniformly mixed. Among them, the antioxidant
includes one or a combination of N-phenyl-a-aniline,
N-phenyl-ß-naphthylamine, N-phenyl-N'-cyclohexyl
p-phenylenediamine. The plasticizer includes one or a combination
of di-n-octyl phthalate, benzene polyacrylates, diisobutyl
phthalate, and dimethyl phthalate. In this step, the additive is
not limited to the additives such as antioxidants and plasticizers
listed in the step, and other additives may be added according to
actual conditions and needs. In this step, a certain proportion of
the absorbing agent carbonyl iron powder is added to further
improve the absorbing properties of the finally obtained tapered
absorbing material. The carbonyl iron powder has strong absorbing
ability and large magnetic loss, but its density is large, the
absorbent has a large duty ratio, and has a large specific surface
area. Therefore, it is difficult to mix with rubber, so In the
invention, the good mixing effect of the carbonyl iron powder and
the urethane rubber is achieved by adjusting the ratio of various
auxiliaries to ensure uniform mixing of the carbonyl iron powder
and the urethane rubber.
Step 2: Press-molding the dense polyurethane rubber in a pyramidal
mold to obtain a tapered absorbing material. In this step, in the
step of press-molding the urethane rubber in a pyramidal mold in a
flat vulcanizer, vulcanization is carried out at a temperature of
160 to 170 ° C, and the vulcanization time is 25 to 30 min. . In
this step, the pyramid mold used includes a plurality of adjacent
and repeatedly arranged quadrangular pyramid holes. Preferably,
the pyramid mold has a size of 330 mm × 330 mm, and the pyramidal
mold removes the cone absorbing wave. The height behind the
material is 22mm (including the base). In this step, since the
tapered absorbing material to be prepared has a plurality of
quadrangular conical members arranged in a dense and convex shape,
it is necessary to control the press forming process in the press
forming, and the preparation method provided by the present
invention has The tapered mold of a specific structure and the
process of controlling the press forming ensure the integrity of
the press-forming of the tapered absorbing material. 1 is a
partial structural schematic view of a tapered absorbing material
according to an embodiment of the present invention. As shown in
Figure 1, the resulting tapered absorbing material comprises a
plurality of adjacent and densely repeating quadrangular pyramids
1.
The tapered absorbing material provided by the invention comprises
a plurality of adjacent and repeatedly arranged quadrangular
pyramids and is added with a absorbing agent carbonyl iron powder,
so that the broadband absorbing property is good, and the
microwave to millimeter wave can be realized. Good absorbing
properties in a wide frequency range, and can be consumed by
multiple reflections between the tips of a plurality of
quadrangular pyramids and in which the absorbing agent converts
the energy of electromagnetic waves into heat energy, and has a
specific band Good absorbing effect. The tapered absorbing
material of the present invention can be applied to many fields
such as aerospace, high-speed locomotives, ships, radar antennas,
and electronics.
Example 1
100 parts by weight of polyurethane rubber, 2 parts of stearic
acid, 1 part of antioxidant N-phenyl-a-aniline, 2 parts of dicumyl
peroxide, 3 parts of plasticizer orthobenzene Di-n-octyl
dicarboxylate and 60 parts of carbonyl iron powder are mixed and
kneaded uniformly in an internal mixer and at a temperature of 65
° C to obtain a dense polyurethane rubber;
In the flat vulcanizing machine, the dense polyurethane rubber is
press-formed in a pyramidal mold, and vulcanization is carried out
at a temperature of 160 ° C in a press molding process, and the
vulcanization time is 25 min, thereby producing a cone-shaped
absorbing wave. material. Wherein, the pyramid mold comprises a
plurality of adjacent and repeatedly arranged quadrangular pyramid
holes, the size of the pyramid mold is 330 mm×330 mm, and the
height of the pyramid mold after removing the cone absorbing
material is 22 mm (including Base).
Example 2
100 parts of urethane rubber, 0.3 parts of stearic acid, 0.5 part
of antioxidant N-phenyl-ß-naphthylamine, 2 parts of dicumyl
peroxide, 5 parts of benzene polyacrylate plasticizer, and 70
parts of carbonyl iron powder in an internal mixer and at a
temperature of 85 ° C, mixed in a mass fraction, uniform to obtain
a dense polyurethane rubber;
In the flat vulcanizing machine, the dense polyurethane rubber is
press-formed in a pyramidal mold, and in the press molding
process, vulcanization is performed at a temperature of 170 ° C
and the vulcanization time is 30 min, thereby producing a
cone-shaped absorbing wave. material. Wherein, the pyramid mold
comprises a plurality of adjacent and repeatedly arranged
quadrangular pyramid holes, the size of the pyramid mold is 330
mm×330 mm, and the height of the pyramid mold after removing the
cone absorbing material is 22 mm (including Base).
Example 3
100 parts by weight of polyurethane rubber, 3 parts of stearic
acid, 1.5 parts of antioxidant N-phenyl-N'-cyclohexyl
p-phenylenediamine, 1.5 parts of dicumyl peroxide, 2 parts by mass
The plasticizer diisobutyl phthalate and 50 parts of carbonyl iron
powder are mixed and kneaded uniformly in an internal mixer and at
a temperature of 70 ° C to obtain a dense polyurethane rubber;
In the flat vulcanizing machine, the dense polyurethane rubber is
press-molded in a pyramidal mold, and vulcanization is carried out
at a temperature of 165 ° C during the press molding process, and
the vulcanization time is 38 min, thereby producing a cone-shaped
absorbing wave. material. Wherein, the pyramid mold comprises a
plurality of adjacent and repeatedly arranged quadrangular pyramid
holes, the size of the pyramid mold is 330 mm×330 mm, and the
height of the pyramid mold after removing the cone absorbing
material is 22 mm (including Base).
Example 4
100 parts by weight of polyurethane rubber, 0.5 parts of stearic
acid, 0.5 part of antioxidant N-phenyl-N'-cyclohexyl
p-phenylenediamine, 1.8 parts of dicumyl peroxide, 6 parts by mass
The plasticizer and 75 parts of carbonyl iron powder are mixed and
kneaded uniformly in an internal mixer and at a temperature of 69
° C to obtain a dense polyurethane rubber;
In the flat vulcanizing machine, the dense polyurethane rubber is
press-formed in a pyramidal mold, and in the press molding
process, vulcanization is performed at a temperature of 167 ° C
and the vulcanization time is 27 min, thereby producing a
cone-shaped absorbing wave. material. Wherein, the pyramid mold
comprises a plurality of adjacent and repeatedly arranged
quadrangular pyramid holes, the size of the pyramid mold is 330
mm×330 mm, and the height of the pyramid mold after removing the
cone absorbing material is 22 mm (including Base).
Example 5
100 parts by weight of polyurethane rubber, 0.5 parts of stearic
acid, 1 part of antioxidant N-phenyl-a-aniline, 3 parts of dicumyl
peroxide, 3 parts of plasticizer orthobenzene Dimethyl diformate
and 80 parts of carbonyl iron powder are mixed and kneaded
uniformly in an internal mixer at a temperature of 82 ° C to
obtain a dense polyurethane rubber;
In the flat vulcanizing machine, the dense polyurethane rubber is
press-formed in a pyramidal mold, and vulcanization is carried out
at a temperature of 162 ° C for 25 minutes in the press molding
process, thereby producing a cone-shaped absorbing wave. material.
Wherein, the pyramid mold comprises a plurality of adjacent and
repeatedly arranged quadrangular pyramid holes, the size of the
pyramid mold is 330 mm×330 mm, and the height of the pyramid mold
after removing the cone absorbing material is 22 mm (including
Base).
The above are only the preferred embodiments of the present
invention, and are not intended to limit the present invention.
Any modifications, equivalents, improvements, etc., which are
within the spirit and scope of the present invention, should be
included in the scope of the present invention. within.
METHOD OF OBTAINING POLYMER COMPOSITION FOR
HIGH-FREQUENCY ENERGY ABSORBING
RU2633903
FIELD: radio engineering, communication.SUBSTANCE: method of
obtaining a polymer composition for high-frequency energy
absorbing is based on the fact that components of the polymer
composition are mixed to absorb high-frequency energy of the
following makeup pts. wt.: a low molecular dimethylsiloxane
caoutchouc SKTN 15-25, carbonyl iron P-10 105-175, a cold curing
accelerator No. 68 1.5-2.5, ethyl silicate-40 1.5-2.5 and cured.
The method includes the steps of weighing rubber of a low
molecular dimethylsiloxane caoutchouc SKTN and ethyl silicate-40,
the mixing these components to a uniform state for 10 minutes at a
temperature of 25±10°C, then injecting into this mixture the
carbonyl iron P-10, previously dried at a temperature of 120±5°C
for 2-3 hours in a pan of a 2-3 cm, cooled to a temperature of
25±10°C and sieved through a sieve ? 0.05. A mixture of a low
molecular dimethylsiloxane caoutchouc SKTN, ethyl silicate-40,
carbonyl iron P-10 is thoroughly mixed for 10 minutes at a
temperature 25±10°C. Then, a cold curing accelerator No. 68 is
injected into the prepared mixture and the mixture is mixed for 10
minutes at a temperature 25±10°C. The final mixture is kept at a
temperature of 25±10°C for 10 minutes to remove air bubbles.
Curing is carried out at a temperature of 25±10°C with not less
than 20 hours, then at a temperature of 160±5°C for 7
hours.EFFECT: reduction of shrinkage of the composition after its
curing, ensuring the stability of the composition after exposuring
high temperature and cyclic temperature changes, increasing the
attenuation of the microwave signal wave.
Microwave shielding device
CN205711688
The utility model discloses a microwave shielding device, the
piece of bending including two mutual symmetric connection, bend
the piece including both ends groove area and intermediate
junction board, ancient piece of jade, round, flat and with a hole
in its centre embedded metal cloth in the groove area, metal cloth
inner chamber is filled has silicon rubber or other elastic
material. In this way, the utility model relates to a microwave
shielding device who goes out, through changeing between the wall
design piece of bending to the microwave applicator flip
horizontal wall with turning on one's side, the piece of the
bending shielding material that makes up tong has effectually
shielded the leakage of microwave applicator heat, has improved
microwave applicator's heating efficiency.
The utility model discloses a microwave shielding device, which
comprises two bending parts which are symmetrically connected with
each other, the bending part comprises a grooved area at both ends
and an intermediate connecting plate, wherein the grooved area is
embedded with a metal cloth. The metal cloth inner cavity is
filled with silicone rubber or other elastic material. Through the
above manner, the microwave shielding device pointed out by the
utility model designs a bending member between the horizontally
flipped wall and the side flip wall of the microwave heater, and
the shielding material inside the bending member is clamped,
thereby effectively shielding the heat leakage of the microwave
heater. The heating efficiency of the microwave heater is
improved.
Microwave shielding device
Technical field
The utility model relates to a microwave heater, in particular to
a microwave shielding device used in a microwave heater.
Background technique
Pavement maintenance mainly requires heating the pavement,
especially the asphalt pavement, to soften it, and then filling
the asphalt to repair the pavement. In the prior art, gas infrared
radiation, open flame, or microwave heating mainly used for road
asphalt heating is used to soften the asphalt of the road surface,
and then new materials are added for road surface repair.
Microwave heaters are generally used in microwave heating
equipment and are connected to the underside of the chassis to
heat the road surface. The microwave heater is designed as a
heating wall. The width of the heating wall cannot be greater than
the width of the road during the walking process. Therefore, when
designing the microwave heating wall, the heating wall is designed
as a horizontal heating wall. And the heating wall is turned on
both sides, so that the heating wall does not affect the walking
of the vehicle, and the maximum Chengdu can make the heating wall
and the width of the road consistent, and the heating efficiency
of the microwave heater is improved.
The inverted heating wall and the horizontal heating wall are
hingedly connected, and the inverted heating wall is horizontally
prevented during operation, and is horizontally level with the
horizontal heating wall. Due to the hinged connection, there is a
long gap between the flip heating wall and the horizontal heating
wall. The gap causes the microwave leakage to exceed the standard,
and at the same time reduces the working efficiency of the
microwave heater.
Utility model content
The technical problem mainly solved by the utility model is to
provide a microwave shielding device. By designing a bending part
between the horizontally flipped wall of the microwave heater and
the side flip wall, the shielding material of the bending part is
clamped, and the microwave heater is effectively shielded. Heat
leakage increases the heating efficiency of the microwave heater.
In order to solve the above technical problem, a technical
solution adopted by the present invention is to provide a
microwave shielding device, which comprises two bending members
symmetrically connected to each other, the bending member
comprising a grooved area at both ends and an intermediate
connecting plate. A metal cloth is embedded in the groove region,
and the inner cavity of the metal cloth is filled with silicone
rubber or other elastic material.
In a preferred embodiment of the present invention, the two
mutually symmetric bending members are connected to each other in
the opening direction of the groove portions.
In a preferred embodiment of the present invention, the groove has
a width of 25-35 mm and is formed by bending a steel plate.
The utility model has the beneficial effects that the microwave
shielding device pointed out by the utility model designs a
bending member between the horizontally flipped wall and the side
flip wall of the microwave heater, and the shielding material
inside the bending member is clamped, and the microwave heating is
effectively shielded. The heat leakage of the device increases the
heating efficiency of the microwave heater.
DRAWINGS
In order to more clearly illustrate the technical solutions in the
embodiments of the present invention, the drawings used in the
description of the embodiments will be briefly described below. It
is obvious that the drawings in the following description are only
some implementations of the present invention. For example, those
skilled in the art can obtain other drawings according to these
drawings without any creative work, among which:
1 is a schematic structural view of a microwave shielding device
according to a preferred embodiment of the present invention.
Detailed ways
The technical solutions in the embodiments of the present
invention are clearly and completely described below. It is
obvious that the described embodiments are only a part of the
embodiments of the present invention, and not all of the
embodiments. All other embodiments obtained by those skilled in
the art based on the embodiments of the present invention without
creative efforts are within the scope of the present invention.
Referring to FIG. 1 , an embodiment of the present invention
includes:
A microwave shielding device comprising two bending members 1
symmetrically connected to each other, the bending member 1
comprising a groove portion 11 at both ends and an intermediate
connecting plate 12, wherein the groove portion 11 is embedded
with a metal cloth 2, The inner surface of the metal cloth 2 is
filled with a silicone rubber 3, and the metal cloth 2 is wrapped
with a polytetrafluoroethylene sheet 3 to shield the microwave
leakage.
The two mutually symmetric bending members 1 are connected to each
other in the opening direction of the groove portion.
The groove has a width of 25-35 mm and is bent by a steel plate to
reduce the blind zone of microwave heating.
The utility model has the beneficial effects that the microwave
shielding device pointed out by the utility model designs a
bending member between the horizontally flipped wall and the side
flip wall of the microwave heater, and the shielding material
inside the bending member is clamped, and the microwave heating is
effectively shielded. The heat leakage of the device increases the
heating efficiency of the microwave heater.
The above description is only an embodiment of the present
invention, and thus does not limit the scope of the patent of the
present invention. Any equivalent structure or equivalent process
transformation made by using the specification of the present
invention and the contents of the drawings, or directly or
indirectly Other related technical fields are equally included in
the scope of patent protection of the present invention.
COMBAT PROTECTIVE MILITARY DRESS
UA98637
Combat protective military dress is a bundle of clothing...
are multi-layer composite structure based magnetic ferrite
magnetic powders with a high dielectric losses and rubber
compounds attached to the outer surface of each of the units set
of clothing, ...and the screening package made multiple odd number
of quarters of working medium wave band that emits electromagnetic
microwave radiation generator.
Preparation method of graphene-based
composite wave-absorbing material
CN108034408
The method comprises the following steps: firstly, preparing
graphene oxide by using natural graphite powder as a raw material,
using concentrated sulfuric acid and permanganate as an oxidizing
agent and adopting an improved Hummers method; then, preparing
neodymium-cobalt doped strontium ferrite by selecting nitrates of
strontium, neodymium, cobalt and iron as raw materials, taking
citric acid as a complexing agent and using a sol-gel
self-propagating method; after that, preparing a
graphene/neodymium-cobalt doped strontium ferrite composite
material by taking dimethyl formamide as a solvent, using
hexadecyl trimethyl ammonium bromide as a surface active agent,
taking hydrazine hydrate asa reducing agent, and adopting a
self-assembly method; finally, evenly mixing the
graphene/neodymium-cobalt doped strontium ferrite composite
material with an aniline monomer, and preparing a ternarynano
composite material by taking ammonium persulfate as an initiator
and using an in-situ polymerization method. The material is low in
preparation cost, simple in technology, low in density, high
inwave-absorbing ability and wide in frequency band, thus having
an important application value in the aspects of microwave
absorption and electromagnetic wave shielding.
The invention relates to a preparation method of a graphene-based
composite absorbing material. Firstly, a natural graphite powder
is used as a raw material, concentrated sulfuric acid and
permanganate are used as oxidants, and a modified Hummers method
is used to prepare graphene oxide, and then ruthenium and osmium
are selected. Cobalt and iron nitrates are used as raw materials,
citric acid is used as a complexing agent, samarium-cobalt-doped
barium ferrite is prepared by sol-gel-self-propagation method, and
then dimethylformamide is used as solvent, cetyl group III.
Ammonium methylammonium bromide is a surfactant, hydrazine hydrate
is a reducing agent, and graphene/samarium-cobalt-doped barium
ferrite composite material is prepared by self-assembly method.
Finally, graphene-yttrium-cobalt-doped barium ferrite composite
material is used. The aniline monomer is uniformly mixed, and
ammonium persulfate is used as an initiator to obtain a ternary
nanocomposite by in-situ polymerization. The material has low
preparation cost, simple process, low density, strong absorbing
ability and frequency bandwidth, and has important application
value in microwave absorption and electromagnetic wave shielding.
Preparation method of graphene-based composite absorbing material
Technical field
The invention relates to a preparation method of a absorbing
material, in particular to a preparation method of a
graphene-based composite absorbing material, and belongs to the
technical field of absorbing materials.
Background technique
In the 21st century, where science and technology are developing
rapidly, various electronic products have come out one after
another and quickly entered the homes of ordinary people, bringing
great convenience to life. However, people are worried that they
are suffering from different electromagnetic waves while enjoying
these benefits. Degree of violation. Long-term in the
electromagnetic wave environment, it is easy to cause the human
body to produce lesions, and electromagnetic waves will interfere
with the normal operation of various electronic devices and
communication instruments, and even cause malfunction.
Electromagnetic interference is the fourth largest source of
environmental pollution after industrial “three wastes”.
Therefore, how to effectively prevent and eliminate
electromagnetic interference has become the focus of the
scientific and technological community.
Graphene, a honeycomb two-dimensional material, has been
successfully ranked among the top in the list of commonly used
absorbing materials due to its light weight, large specific
surface area, good flexibility, good electrical conductivity and
large dielectric loss. At the same time, the surface of the
oxidized graphene is exposed to a large number of chemical bonds,
and the polarization relaxation is more likely to occur under the
action of the electromagnetic field, thereby achieving the purpose
of attenuating the electromagnetic wave, which also makes the
application of graphene in the field of absorbing waves more
broad. However, new absorbing materials need to meet the
requirements of “thin, light, wide and strong”. Electrical losses
are mainly derived from electron polarization, atomic
polarization, intrinsic electric dipole orientation polarization,
and interfacial polarization. Magnetic losses mainly include eddy
current loss, hysteresis loss and residual loss. Graphene has
large dielectric loss and a small amount of magnetic loss. The
single graphene interface has poor impedance matching, and its
loss mechanism is less, and the absorbing effect is not strong.
However, since graphene has a large specific surface area, it can
be combined with a magnetic loss absorbing material to form a
complementary advantage. On the one hand, the combination of the
electric loss absorbing material and the magnetic loss absorbing
material can exert two forms of electromagnetic loss. To obtain
better electromagnetic wave absorption performance; on the other
hand, compounding with light weight graphene material is also
beneficial to reduce the weight of the absorbing material.
Summary of the invention
The object of the present invention is to solve the deficiencies
of the prior art and provide a method for preparing a
graphene-based composite absorbing material. The method is simple,
easy to operate, low in cost, and has high dielectric loss and
magnetic loss of the absorbing material. Stable performance,
absorbing bandwidth and good absorbing performance.
In order to achieve the above object, the inventors combine
graphene with samarium-cobalt-doped barium ferrite to improve the
impedance matching thereof, and further add a conductive polymer
as a coating layer in the composite system to enhance the
interface bonding between the magnetic particles and graphene. At
the same time, the conductive polymer itself has high dielectric
loss, and the ternary composite can enhance the absorbing
properties of the material in the high frequency band.
The specific plan is as follows:
A graphene-based composite absorbing material is a "sandwich
structure", the middle layer is graphene/samarium cobalt doped
barium ferrite, and the outermost layer is polyaniline.
The preparation method of the above graphene-based composite
absorbing material comprises the following steps:
(1)Preparation of graphene oxide: weigh 3 ~ 4g graphite powder,
2.5 ~ 3.5g persulfate and 2 ~ 4g P2O5 are added to 15 ~ 18ml
concentrated sulfuric acid, stirred at 80 ~ 85 ° C for 6 ~ 8h, to
be cooled by the reaction system After being brought to room
temperature, diluted with distilled water to a pH of 4 to 5,
allowed to stand for 20 to 24 hours, filtered, washed with water
until the filtrate is neutral, and the obtained product is dried
to constant weight at room temperature to obtain pre-oxidized
graphite; pre-oxidized graphite is added Stir well in 120~150mL
concentrated sulfuric acid, and slowly add 15~18g strong oxidant
in the ice water bath. After stirring evenly, slowly heat up to
35~40°C, continue to react for 2~4h, slowly add 250~ to the
system. 300mL distilled water, followed by reaction for 2 ~ 3h,
the temperature of the control system does not exceed 50 ° C, add
300 ~ 350mL distilled water again and stir until the system is
uniform, then add 10 ~ 40ml of 30% concentration of hydrogen
peroxide, the solution turns bright brown, centrifuge After
separation, it is washed with hydrochloric acid solution, and
finally dialyzed against distilled water for 7-8 days, and the
obtained upper layer dispersion is freeze-dried to obtain graphene
oxide;
(2)Preparation of SNCF (samarium-cobalt-doped barium ferrite):
Sr(NO3)2, Fe(NO3) is weighed according to the stoichiometric ratio
of the samarium-cobalt-doped barium ferrite chemical formula
Sr0.85Nd0.15Co0.15Fe11.85O19 3·9H2O, Nd(NO3)3·6H2O, Co(NO3)2·4H2O
is dissolved in distilled water, and stirred to obtain a clear
solution. The citric acid solution is slowly added dropwise, and
the pH is adjusted to 7 after stirring, to obtain a sol. The sol
is evaporated in a 75-85 ° C water bath and stirred to obtain a
wet gel, and the wet gel is dried, and then ignited in the air to
obtain a fluffy precursor, which is ground and calcined to obtain
SNCF;
(3)Preparation of graphene/samarium-cobalt-doped barium ferrite
composite material: taking graphene oxide and
samarium-cobalt-doped barium ferrite in DMF respectively,
obtaining graphene oxide solution and samarium-cobalt-doped barium
ferrite suspension Liquid, adding cetyltrimethylammonium bromide
(CTAB) to the graphene oxide solution, dispersing uniformly,
slowly adding dropwise to the samarium-cobalt-doped strontium
ferrite suspension, mixing uniformly, and then reacting The system
is added with hydrazine hydrate, stirred in a 95 ° C water bath
for 12 to 14 h, then suction filtered, washed with water, alcohol
washed until the filtrate is neutral, and finally vacuum dried to
obtain a graphene/samarium cobalt doped barium ferrite composite
material;
(4)Preparation of graphene-based composite absorbing materials:
taking graphene/samarium-cobalt-doped barium ferrite composite
material and 1-2 ml of aniline monomer dissolved in 30-50 ml of
hydrochloric acid solution, graphene/samarium-cobalt-doped barium
ferrite The molar ratio of the composite material to the aniline
is 1:2.5, and the dispersion is uniform to obtain a dispersion;
2.5 to 3.5 g of ammonium persulfate is dissolved in 20-30 ml of
hydrochloric acid solution to obtain a transparent solution, which
is slowly added dropwise to the above dispersion. After stirring
in an ice water bath for 12 to 15 hours, it was subjected to
suction filtration, water washing, alcohol washing, and vacuum
drying to obtain a graphene-based composite absorbing material.
Further, in the step (1), the persulfate is potassium persulfate
or sodium persulfate.
Further, in the step (1), the strong oxidizing agent is potassium
permanganate or potassium dichromate.
Further, in the step (1), the hydrochloric acid solution has a
volume concentration of 10%.
Further, in the step (2), the amount of citric acid is added in a
molar ratio of 1:1 to the metal ion.
Further, in the step (2), the drying temperature is 120 ° C and
the time is 10 to 12 h.
Further, in the step (2), the calcination temperature is 900 ° C
and the time is 2-4 h.
Further, in the step (3), the molar ratio of graphene oxide to
samarium cobalt-doped barium ferrite is 6:100, and the molar ratio
of cetyltrimethylammonium bromide to graphene oxide is 0.8:100.
The molar ratio of hydrazine hydrate to graphene oxide was 0.7:1.
Further, in the step (3), the temperature of the vacuum drying is
60 ° C, and the time is 10 to 12 h.
Further, in the step (4), the hydrochloric acid solution has a
concentration of 1.0 mol/L.
The invention has the advantages that the method has the
advantages of simple method, easy operation and low cost, and the
prepared absorbing material has high dielectric loss and magnetic
loss, stable electromagnetic performance, absorbing wave frequency
bandwidth and good absorbing performance, and is in the field of
electromagnetic wave shielding and electromagnetic wave
absorption. Very good application prospects.
DRAWINGS
1 is an XRD pattern of a graphene-based composite absorbing
material prepared in Example 1;
2 is a graph showing the absorbing properties of the
graphene-based composite absorbing material prepared in Example 1.
Detailed ways
The invention is further described below in conjunction with the
drawings and specific embodiments.
Example 1
(1)Preparation of graphene oxide: Weigh 3g graphite powder, 2.5g
sodium persulfate and 2.5g P2O5 were added to 15ml concentrated
sulfuric acid, stirred at 80 ° C for 6h, after the reaction system
was cooled to room temperature, diluted with distilled water to a
pH of 4 After standing for 20 h, it was filtered, washed with
water until the filtrate was neutral, and the obtained product was
dried to constant weight at room temperature to obtain
pre-oxidized graphite; the pre-oxidized graphite was added to 120
mL of concentrated sulfuric acid, stirred uniformly, and slowly
cooled in an ice water bath. Add 15g of strong oxidizing agent
potassium permanganate, stir evenly, slowly heat up to 35 ° C,
continue the reaction for 2h, slowly add 250mL distilled water to
the system, then react for 2h, control system temperature does not
exceed 50 ° C, add 350mL distilled water again To the system
uniform, then add 10ml of 30% hydrogen peroxide solution, the
solution turns bright brown, after centrifugation, wash with 1L
volume of 10% hydrochloric acid solution, and finally dialyzed
with distilled water for 7d to remove residual metal ions and acid
, the obtained upper layer dispersion is freeze-dried to obtain
graphene oxide GO;
(2)Preparation of SNCF (samarium-cobalt-doped barium ferrite):
Sr(NO3)2, Fe(NO3)3·9H2O, Nd(NO3)3·6H2O are weighed according to
the stoichiometric ratio of strontium-cobalt-doped barium ferrite.
Co(NO3)2·4H2O is dissolved in distilled water and stirred to
obtain a clear solution. According to the molar ratio of metal
ions to citric acid 1:1, citric acid is weighed as a complexing
agent and dissolved in distilled water to obtain a citric acid
solution. The acid solution was slowly added dropwise to the above
clear solution, stirred and adjusted to pH 7, to obtain a sol. The
sol was evaporated in a water bath at 80 ° C and stirred to obtain
a wet gel. The wet gel was dried and dried at 120 ° C for 12 h,
then Ignite in the air to obtain a fluffy precursor, calcined
after grinding, calcined at 900 ° C for 3 h to obtain SNCF;
(3)Preparation of graphene/samarium-cobalt-doped barium ferrite
composite material: GO and samarium-cobalt-doped barium ferrite
were weighed into dimethylformamide according to
m(GO):m(SNCF)=6:100 To obtain a graphene oxide solution and a
samarium-cobalt-doped barium ferrite suspension, and to add
cetyltrimethylammonium bromide (CTAB) to the graphene oxide
solution, (m(CTAB):m(GO) ) = 0.8: 100), ultrasonically 2h, the GO
solution was slowly added dropwise to the samarium-cobalt-doped
strontium ferrite suspension, and stirred for 1 h to make the
mixture uniform, according to m (hydrated hydrazine): m (GO) = 0.7
The ratio of 1:1, hydrazine hydrate was added to the reaction
system, stirred in a water bath at 95 ° C for 12 h, then suction
filtered, washed with water and alcohol washed until the filtrate
was neutral, and dried under vacuum at 60 ° C for 12 h to obtain
graphene/samarium cobalt doped cesium. Ferrite composite.
(4)Preparation of graphene-based composite absorbing materials:
graphene/samarium-cobalt-doped barium ferrite composite and 1 ml
of aniline monomer dissolved in 30 ml of hydrochloric acid
solution, graphene/samarium-cobalt-doped barium ferrite composite
and aniline The molar ratio is 1:2.5, and the dispersion is
uniform to obtain a dispersion; 2.5 g of ammonium persulfate is
dissolved in 20 ml of a 1 mol·L<-1> hydrochloric acid
solution to obtain a transparent solution, which is slowly added
dropwise to the above dispersion. After stirring for 12 hours in
an ice water bath, it was subjected to suction filtration, water
washing, alcohol washing, and vacuum drying at 60 ° C for 12 hours
to obtain a graphene-based composite absorbing material.
The phase structure analysis of the graphene-based composite
absorbing material prepared in Example 1 was carried out by X-ray
diffractometer. The XRD pattern is shown in Fig. 1. In Fig. 1, (a)
indicates SNCF, and (b) indicates RGO/SNCF nanocomposite.
Materials, (c) denotes RGO/SNCF/PANI nanocomposites, (d) denotes
GO, and (e) denotes PANI. From Fig. 1, we can see that at 30.1°,
32.2°, 34.1°, 37.0°, 40.3 Characteristic diffraction peaks
appeared at °, 42.3°, 55.20°, 56.83° and 63.31°, which is
basically consistent with the characteristic peak of standard
SrFe12O19, indicating that the prepared SNCF ferrite is still
magnetite. Type, samarium cobalt enters the lattice of barium
ferrite very well, and no other impurity phase is formed.
Figures 1(b) and (c) correspond to the XRD patterns of RGO/SNCF
and RGO/SNCF/PANI, respectively. The characteristic peaks of SNCF
can be clearly seen from the two graphs. The GO shown in Figure
1(a) is not shown. The characteristic peak around 10° indicates
that under the action of the reducing agent hydrazine hydrate, GO
is reduced to RGO, and SNCF is dispersed onto the RGO sheet by
self-assembly.
It is worth noting that no significant PANI peaks were observed in
the XRD pattern of RGO/SNC/PANI, probably due to the low PANI
content in the system.
The electromagnetic parameters and absorbing properties of the
samples were analyzed by vector network analysis. The results are
shown in Fig. 2. Fig. 2 is the absorbing performance of the
graphene-based composite absorbing materials prepared in Example
1, which is RGO with RGO content of 6%. The reflectance loss curve
of /SNCF/PANI nanocomposites at different thicknesses. It can be
seen from Fig. 2 that the reflection loss value is -42.4dB when
the thickness is 2mm, the corresponding peak frequency is
14.56GHz, and the effective absorption band is 5.7GHz. , exhibits
excellent absorbing properties.
It is to be understood that those skilled in the art can make
modifications and changes in the form of the above description,
and all such modifications and changes are intended to be included
within the scope of the appended claims.
Composition for microwave shielding
material
TW229336
composition for microwave shielding material, which comprises: (a)
a 65 to 90 weight percent of iron and cobalt mixed powder blending
in rubber matrix, where this mixture is obtained from carbonyl
iron powder and cobalt powder after mechanical processing, where
the mixing ratio is from 6.5:3.5 to 9.5:0.5, where the diameter of
the matrix is from 1 to 7.5 micrometers and where the surface area
is from 0.1 to 1.0 square meters per gram; (b) 10 to 35 weight
percent of rubber and vulcanization processing dose.
Microporous wave-absorbing material with
low surface density and high tensile strength and preparation
method
CN103589010
The invention discloses a microporous wave-absorbing material with
low surface density and high tensile strength and a preparation
method and belongs to the technical field of wave-absorbing
material. According to the invention, problems of high density,
low mechanical properties and poor temperature resistance of a
present microwave material are solved. The preparation method
comprises steps of: uniformly stirring rubber, zinc oxide,
eleaostearic acid, an anti-aging agent, a flow promoter, sulphur,
a promoter, a foaming agent, a plasticiser and an absorbent,
banburying, open-milling, vulcanizing at 150-160 DEG C and
simultaneously foaming for 25-35min so as to obtain the
microporous wave-absorbing material. The total thickness of the
prepared microporous wave-absorbing material is between 1.4mm and
2.0mm, and its surface density is less than 1.7kg/m<2>. The
material has good wave-absorbing performance at specific
wavelengths. Meanwhile, the material has good temperature
resistance and mechanical property. The temperature that the
material resists can reach 150 DEG C. Average value of tensile
strength is greater than 8.5MPa, and the minimum elongation at
break is 360%.
The invention discloses a micropore absorbing material with low
surface density and high tensile strength and a preparation method
thereof, and belongs to the technical field of absorbing
materials. The problem that the existing microwave material has
high density, low mechanical property and poor temperature
resistance is solved. The preparation method of the invention
comprises the steps of: mixing rubber, zinc oxide, stearic acid,
anti-aging agent, flow aid, sulfur, accelerator, foaming agent,
plasticizer and absorbent, and then mixing and kneading, in
Vulcanization at 150-160 ° C and simultaneous foaming for 25-35
min gives a microporous absorbing material. The microporous
absorbing material prepared by the invention has a total thickness
of between 1.4 and 2.0 mm and an areal density of less than 1.7
kg/m. The material has good absorbing properties in a specific
wavelength band, and has good temperature resistance and
mechanics. The temperature resistance can reach 150 ° C, the
average tensile strength is greater than 8.5 MPa, and the minimum
elongation at break is 360%.
Low-density density high tensile strength microporous absorbing
material and preparation method thereof
Technical field
The invention relates to a microporous absorbing material with low
areal density and high tensile strength and a preparation method
thereof, and belongs to the technical field of absorbing
materials.
Background technique
In the prior art, the patch type absorbing material is generally
formed by mixing and rolling an adhesive with an absorbent
(generally a magnetic material). By selecting different substrates
and optimizing the formulation design, the performance of the
absorbing materials can meet different needs. Such patch-type
materials have the advantages of good uniformity, strong process
controllability, stable material properties (especially electrical
properties), and simple construction process.
However, the existing patch-type absorbing materials generally
have the disadvantage of high surface density, and the surface
density of the absorbing sheets having a thickness of less than 1
mm has mostly exceeded 3.0 kg/m < 2 >, and the strength is
generally about 4 MPa, and the temperature is resistant. The
performance is generally lower than 100 ° C, which cannot meet the
mechanical properties of equipment such as aircraft.
Summary of the invention
The object of the present invention is to solve the problems of
large surface density, low mechanical properties and poor
temperature resistance of the prior art absorbing materials, and
to provide a absorbing material with low areal density and high
tensile strength and a preparation method thereof.
The low surface density high tensile strength microporous
absorbing material of the invention comprises rubber, zinc oxide,
stearic acid, anti-aging agent, flow aid, sulfur, accelerator,
foaming agent, plasticizer and absorbent; The mass ratio of the
rubber, the foaming agent and the plasticizer is 100: (5-18):
(15-25); the blowing agent is azodicarbonamide (AC), modified azo
Amide (ACPW) or N,N'-dimethylpentamethyltetramine; the absorbent
is micron-sized conductive carbon black, the mass of the absorbent
is rubber, zinc oxide, stearic acid, anti-aging agent, flow aid
30-40% of the total mass of the agent, sulfur, accelerator,
blowing agent and plasticizer.
Preferably, the mass of the absorbent is 5-18% of the total mass
of the rubber, zinc oxide, stearic acid, antioxidant, flow aid,
sulfur, accelerator, foaming agent and plasticizer.
Preferably, the mass ratio of the rubber, zinc oxide, stearic
acid, antioxidant, flow aid, sulfur and accelerator is
100:5:2:2:1.5:2:1.
Preferably, the rubber is a nitrile rubber or a hydrogenated
nitrile rubber.
Preferably, the antioxidant is N,N-dibutyldithiocarbamate (NBC),
2,2,4-trimethyl-1,2-dihydroquinoline polymer (RD), N One or more
of isopropyl-N'-phenyl-p-phenylenediamine (4010NA).
Preferably, the flow aid is a particulate fatty acid, a
particulate fatty acid derivative or granular isonicate
pentaerythritol.
Preferably, the promoter is N-cyclohexyl-2-benzothiazole
sulfenamide (CZ) or 2-thiol benzothiazole (MBT).
Preferably, the plasticizer is one or more of dibutyl phthalate,
dioctyl phthalate, and diethyl phthalate.
The preparation method of the low surface density and high tensile
strength microporous absorbing material comprises the following
steps:
(1)After mixing rubber, zinc oxide, stearic acid, antioxidant,
flow aid, sulfur, accelerator, foaming agent, plasticizer and
absorbent, the mixture is uniformly mixed to obtain a mixture;
(2)The mixture obtained in the step (1) is kneaded to obtain a
uniformly stable raw material;
(3)Te uniformly stable raw material obtained in the step (2) is
vulcanized at 150-160 ° C and foamed at the same time for 25-35
min to obtain a microporous absorbing material having a low areal
density and a high tensile strength.
Preferably, in the step (1), the kneading is carried out in an
internal mixer at 85 ° C for 10-15 min, and in the step (2), the
kneading is carried out in the open mill for 20 or more times. .
The beneficial effects of the invention:
(1)The invention adopts the micron-scale conductive carbon black
as the absorbent, so that the material has excellent absorbing
property and has low surface density, and provides a certain
reinforcing effect to the material, further increases the
mechanical properties of the material; and adopts and vulcanizes
The foaming agent in the same temperature interval causes the
material to be vulcanized while being vulcanized in the
preparation process, thereby ensuring uniform distribution of
cells and having a closed cell structure, thereby realizing low
density and high strength of the material;
(2)The microporous absorbing material prepared by the invention
has a total thickness of between 1.4 and 2.0 mm, and an areal
density of less than 1.7 kg/m < 2 >. The material has good
absorbing properties in a specific wavelength band and has good
temperature resistance. And mechanical properties, temperature
resistance can reach 150 ° C, the average tensile strength is
greater than 8.5 MPa, the minimum elongation at break is 360%;
(3)The preparation method of the invention foams at the same time
as the material is vulcanized, which not only ensures the
structure of the microwave material, but also is simple, easy and
low in cost, and is advantageous for mass production.
DRAWINGS
1 is a graph showing a flat plate reflectance test of a
microporous absorbing material prepared in Example 1-3 of the
present invention;
2, (a) is an optical microscope image of a cross section of a
microporous absorbing material prepared in Example 1 of the
present invention; (b) is an optical microscope imaging of a cross
section of a microporous absorbing material prepared in Example 2
of the present invention; Figure.
Detailed ways
For a better understanding of the present invention, the preferred
embodiments of the present invention are described in the
accompanying drawings.
The low surface density high tensile strength microporous
absorbing material comprises 100 parts by weight of rubber, 5
parts by weight of zinc oxide, 2 parts by weight of stearic acid,
2 parts by weight of an antioxidant, 1.5 parts by weight of a flow
aid, 2 parts by weight of sulfur, 1 part by weight of a promoter,
5-18 parts by weight of a foaming agent, 15-25 parts by weight of
a plasticizer and an absorbent; wherein the rubber is a nitrile
rubber 220 or a hydrogenated nitrile rubber; The antioxidant is
N,N-dibutyldithiocarbamate, 2,2,4-trimethyl-1,2-dihydroquinoline
polymer, N-isopropyl-N'-phenyl pair One or more of
phenylenediamine; the flow aid is a granular fatty acid, a
granulated fatty acid derivative or granulated isonicate stearic
acid, preferably a particulate fatty acid derivative ZC-56 or a
granulated stearic acid Pentaerythritol D-821; accelerator is
N-cyclohexyl-2-benzothiazole sulfenamide or 2-thiol benzothiazole;
plasticizer is dibutyl phthalate, phthalic acid One or more of
octyl ester and diethyl phthalate; the blowing agent is
azodicarbonamide, modified azodicarbonamide or
N,N'-dimethylpentamethyltetramine Absorbent is micron Conductive
carbon black, the mass of which is 30-40%, preferably 5-18% of the
total mass of rubber, zinc oxide, stearic acid, antioxidant, flow
aid, sulfur, accelerator, foaming agent and plasticizer It is well
known in the art that the default blowing agent has no residual
calculation after forming the final product).
The preparation method of the low-density high tensile strength
microporous absorbing material comprises the following steps:
(1)The rubber, the zinc oxide, the stearic acid, the antioxidant,
the flow aid, the sulfur, the accelerator, the foaming agent, the
plasticizer and the absorbent are physically stirred uniformly,
and then uniformly mixed and mixed in an internal mixer to obtain
a mixture;
The mass ratio of the rubber, zinc oxide, stearic acid,
antioxidant, flow aid, sulfur, accelerator, foaming agent and
plasticizer is 100:5:2:2:1.5:2:1:(5 -18): (15-25), the blowing
agent is azodicarbonamide, modified azodicarbonamide or
N,N'-dimethylpentamethyltetramine, and the absorbent is
Micron-scale conductive carbon black, the mass of which is 30-40%,
preferably 5-18, of the total mass of rubber, zinc oxide, stearic
acid, antioxidant, flow aid, sulfur, accelerator, foaming agent
and plasticizer % (according to the field, the default blowing
agent has no residual calculation after forming the final
product);
(2)The mixture obtained in the step (1) is added to an open mill,
and is opened by a process of wrapping rolls to obtain a uniformly
stable raw material;
(3)The uniform and stable raw material obtained in the step (2) is
added into the mold, the mold is placed in a flat vulcanizing
machine, vulcanized at 150-160 ° C and foamed at the same time for
25-35 min, and the excess edge material is cut off to obtain a low
surface density. Tensile strength microporous absorbing material.
In the present invention, the rubber is a nitrile rubber 220 or a
hydrogenated nitrile rubber, and the antioxidant is
N,N-dibutyldithiocarbamate, 2,2,4-trimethyl-1,2-dihydroquine. One
or more of porphyrin polymer,
N-isopropyl-N'-phenyl-p-phenylenediamine, flow aid is granular
fatty acid, granular fatty acid derivative ZC-56 or granular
isostearic acid Tetraol D-821, preferably granular fatty acid
derivative ZC-56 or granular stearic acid isovaltol D-821, the
accelerator is N-cyclohexyl-2-benzothiazole sulfenamide or 2-thiol
The benzothiazole, the plasticizer is one or more of dibutyl
phthalate, dioctyl phthalate, and diethyl phthalate.
In the step (1) of the present invention, the order of adding
rubber, zinc oxide, stearic acid, anti-aging agent, flow aid,
sulfur, accelerator, foaming agent, plasticizer and absorbent has
certain requirements, according to the field personnel It is well
known that sulfur and accelerators are added at the end in order
to prevent premature vulcanization from excessive temperature.
In the step (1) of the present invention, in order to prevent the
active ingredient from being destroyed at a high temperature, the
temperature of the mixing process is preferably controlled within
85 °C.
In the step (2) of the present invention, the rubber opening
process is not uniform enough to be fully smelted according to the
conventional three-pack two-rolling process of the rubber mixing
process. Therefore, it is preferred to use a method of 20 or more
times of kneading. .
The types of internal mixers and open mills used in the present
invention are selected in accordance with the amount of the
absorbing material to be prepared.
The die vulcanizer used in the present invention has a die size of
200×200 mm < 2 > or 300×300 < 2 > mm, more preferably
300×300 < 2 > mm, and the cavity height can be adjusted, and
is between 1.0 and 2.0 mm according to requirements. Variety.
The present invention will be further described in detail below
with reference to the embodiments and the accompanying drawings.
Example 1
100 g of nitrile rubber 220, 5 g of zinc oxide, 2 g of stearic
acid, 2 g of N,N-dibutyldithiocarbamate, 1.5 g of granular fatty
acid, 2 g of sulfur, 1 g of N-cyclohexyl-2-benzothiazole
Sulfonamide, 5 g of azodicarbonamide, 15 g of dibutyl phthalate
and 40.5 g of micron-sized conductive carbon black are added to
the internal mixer at 85 ° C to be uniformly mixed to obtain a
mixture; the mixture obtained by the mixing is moved Open to the
open mill to obtain a uniform and stable raw material, and then
cut 62.0g of raw material into a suitable size into a mold of 200
× 200 < 2 > mm, the cavity height of 1.2mm, 150 ° C in the
flat vulcanizing machine The vulcanization foaming was carried out
for 25 min to obtain a microporous absorbing material, and the
mechanical properties of the material are shown in Table 1.
Example 2
100 g of nitrile rubber 220, 5 g of zinc oxide, 2 g of stearic
acid, 2 g of 2,2,4-trimethyl-1,2-dihydroquinoline polymer, 1.5 g
of granular fatty acid derivative ZC-56, 2 g of sulfur 1g2-thiol
benzothiazole, 10g modified azodicarbonamide, 20g dioctyl
phthalate and 50.225g micron conductive carbon black are added to
the internal mixer and mixed uniformly to obtain a mixture; The
obtained mixture was transferred to an open mill to obtain a
uniform and stable raw material, and then 65.0 g of the raw
material was cut into a suitable size and placed in a mold of 200
× 200 < 2 > mm, and the cavity height was 1.5 mm at 155 ° C.
After vulcanization and foaming in a flat vulcanizing machine for
30 min, a microporous absorbing material was obtained, and the
mechanical properties of the material are shown in Table 1.
Example 3
100 g of hydrogenated nitrile rubber, 5 g of zinc oxide, 2 g of
stearic acid, 1 g of N-isopropyl-N'-phenyl-p-phenylenediamine, 1 g
of nickel N,N-dibutyldithiocarbamate, 1.5 g of granules Isobaric
acid D-821, 2g sulfur, 1g 2-thiol benzothiazole, 15g N,
N'-dimethyl pentamethyltetramine, 20g dioctyl phthalate, 3g
phthalic acid Diethyl dicarboxylate and 50.3275 g of micron-sized
conductive carbon black were mixed and mixed uniformly in an
internal mixer to obtain a mixture; the mixture obtained by the
kneading was transferred to an open mill to obtain a uniform and
stable raw material, and then the 71.0 raw material was cut. The
mold was placed in a 200×200 < 2 > mm mold with a height of
1.7 mm, and vulcanized and foamed in a flat vulcanizer for 35
minutes at 155 ° C to obtain a microporous absorbing material.
The microporous absorbing material of Example 1-2 was fabricated
into a dumbbell sample having a width of 6 mm and an effective
distance of 25 mm.
The mechanical performance testing equipment is the SUNS
electronic universal testing machine of Shenzhen Sansi Vertical
and Horizontal Technology Co., Ltd., and the GB/T528-1998
vulcanized rubber stretching method is tested.
The test results are shown in Table 1.
Table 1 Mechanical properties of the microporous absorbing
materials of Example 1 and Example 2
[image]
The microporous absorbing material obtained in Example 1-3 was cut
into a standard sample of 180×180 mm < 2 >, and the material
RCS test equipment was N-5244A of Agilent vector network analyzer
PNA-X series, and the test method was arcuate. The method is
tested for the 8-12 GHz band.
The test results are shown in Figure 1. The material was cut into
longitudinal sections to obtain a horizontal section, and the
cross-sectional structure was taken by an electron microscope to
obtain the foaming size and foaming distribution. The test results
are shown in Figure 2.
Curve (a) in Fig. 1 is the plate reflectance of the microporous
absorbing material of Example 1, and as can be seen from the curve
(a), the absorption of the material in the range of 8-12 GHz is
lower than -6 dB, and the peak value can be reached - The curve
(b) in Fig. 1 is the plate reflectance of the microporous
absorbing material of Example 2. As can be seen from the curve
(b), the absorption of the material in the range of 8-12 GHz is
lower than -7 dB, and the peak value is It can reach below -25dB;
curve (c) in Figure 1 is the plate reflectivity of the microporous
absorbing material of Example 3, as can be seen from curve (c),
the material absorption in the 8-12 GHz band is lower than -
7.5dB, the peak can reach below -25dB.
2(a) is a cross-sectional optical microscope image of the
microporous absorbing material of Example 1. It can be seen from
the figure that the material foam distribution is relatively
uniform, and the diameter of the closed cell is about 100 µm; FIG.
2(b) For the cross-sectional optical microscopy image of the
microporous absorbing material of Example 2, it can be seen from
the figure that the foamed closed pore diameter of the microwave
material is mostly 100 micrometers, and the maximum value is more
than 200 micrometers.
It will be apparent that the description of the above embodiments
is merely to assist in understanding the method of the present
invention and its core idea. It should be noted that those skilled
in the art can also make several improvements and modifications to
the present invention without departing from the principles of the
present invention. These modifications and modifications are also
within the scope of the claims of the present invention. .
POLYMER COMPOSITION FOR ABSORBING
HIGH-FREQUENCY ENERGY
RU2012111336
FIELD: chemistry.SUBSTANCE: invention relates to radioelectronic
engineering, particularly to producing polymer compositions for
absorbing high-frequency energy in microwave devices, e.g. in
amplifiers of compensation channels of radar stations. The polymer
composition for absorbing high-frequency energy contains a polymer
- low-molecular weight dimethylsiloxane synthetic rubber SKTN, a
cold curing catalyst No68 and absorbent filler - pigment aluminium
powder.EFFECT: invention provides improved absorption properties
with low thickness of the absorbent layer in a wide temperature
range and high humidity.
The invention relates to electronic equipment, in particular the
production of polymer compositions intended to absorb
high-frequency energy in microwave devices, for example, in
amplifiers of compensation channels of radar stations.
Known polymer composition for the absorption of high-frequency
energy [RF patent 2294347 C1, published 27.02.2007], including
synthetic low molecular weight rubber dimethylsiloxane SKTN,
absorbing filler powder alsifer fraction not more than 63 microns
and the catalyst for cold hardening No. 68, with the following
ratio of components, wt.h. .:
Synthetic low-molecular rubber dimethylsiloxane SKTN 15-25 Powder
alsifer fraction not exceeding 63 microns 75-85 Cold-curing
catalyst ?68 0.6 -one,0
The disadvantage of this composition is the complex manufacturing
technology of alsifer powder and low absorbing properties with a
small thickness of the absorbing layer.
The closest in technical essence to the proposed polymer
composition for absorbing high-frequency radiation is [RF Patent
2349615 C1, published March 20, 2009] a polymer composition for
absorbing high-frequency energy, containing synthetic rubber of
low molecular weight dimethylsiloxane SKTN, cold curing catalyst
No. 68, and absorbing iron filler carbonyl radio engineering, in
the following ratio of components, parts by weight:
Synthetic low-molecular rubber dimethylsiloxane SKTN 15-25
Radio-carbonyl iron of the mark ?-10 78-83 Cold-curing catalyst
?68 0.6 -one,0
The disadvantage of the prototype is the high density and low
absorption properties with a small thickness of the absorbing
layer.
The technical result of the invention is to obtain a polymer
composition with high absorbing properties with a small thickness
of the applied absorbing layer in a wide range of temperatures and
high humidity, which is important for onboard equipment of
aircraft.
The essence of the invention is that the proposed polymer
composition for absorbing high-frequency energy contains polymer -
synthetic rubber of low molecular weight dimethylsiloxane SKTN (TU
2294-002-00152000-96) and cold-curing catalyst ?68 (OST
38.03239-81), as well as absorbing filler.
New in the proposed solution is that the polymer composition to
absorb high-frequency energy as an absorbing filler contains
aluminum pigment powder (GOST 5494-71) in the following ratio of
components, parts by weight:
Synthetic low molecular rubber dimethylsiloxane SKTN (TU
2294-002-00152000-96) 15-25 Cold-cured Catalyst No. 68 (OST
38.03239-81) 0.5-1.2 Aluminum pigment powder (GOST 5494-71) 12-20
The polymer composition for absorbing high-frequency energy is
made by simply mixing the components and curing them at room
temperature.
Table 1 shows the compositions of the proposed composition for the
absorption of high-frequency energy.
Table 1 PPN Components Example 1 Example 2 Example 3 1 Low
molecular weight synthetic rubber 15 20 25 dimethylsiloxane SKTN 2
Cold-cured catalyst ?68 0.5 0.85 1.2 <tb > 3 Aluminum
pigment powder 12 16 20
The specified range of components is chosen due to the fact that
with a decrease in the amount of aluminum powder the required
efficiency of microwave energy absorption is not achieved, and
with an increase, the composition is non-technological (viscous,
non-uniform) and cannot be applied with a thin layer.
With an increase in the number of catalyst for cold curing ?68
reduces the viability of the composition, while due to the rapid
increase in viscosity it is impossible to obtain a thin
homogeneous film of the composition.
When reducing the amount of catalyst for cold curing ?68 does not
completely cure the absorbent composition.
Table 2 shows the results of comparative tests of the analogue and
the claimed polymer composition for absorbing high-frequency
energy deposited on the microwave signal amplifier.
Table 2 No. of paragraphs Indicators Prototype (patent 2349615)
Example 1 Example 2 Example 3 1 Microwave signal attenuation in
the range frequencies 8-12 GHz, dB: - at a temperature of + 25 ° C
5 13 15 18 < tb> - at -60 ° C 5 18 16 17 - at + 200 ° C 3 13
< SEP> 15 14 After exposure to high humidity 4 14 13 15 98%
at a temperature of + 40 ° C for 12 days 2 Density, g / cm
<3> 4 , 45 1.55 1.60 1.52 3 The thickness applied 1.0 0.45
0.50 0.60 absorbing of coverage 4 Weight loss no <SEP >>
5 times <SEP >> 5 times <SEP >> 5 times
As can be seen from the data presented in table 2, the proposed
polymer composition for absorbing high-frequency energy has
several advantages:
- the efficiency of the absorption of microwave energy with a
small thickness of the absorbing layer ("13-18 dB" against "5 dB"
with a thickness of less than 1 mm);
- radio-technical characteristics are preserved in a wide range of
temperatures (from -60 ° C to 200 ° C) and exposure to high
humidity;
- lower density ("1.5-1.6 g / cm <3>" against "4.45 g / cm
<3>"), which is important for the onboard equipment of the
aircraft.
- weight reduction of the proposed composition in comparison with
the prototype more than 5 times
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