JP2001313491A - One-dimensional orientation electromagnetic wave absorbing film, method for manufacturing the same and electromagnetic wave absorber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a one-dimension orientation electromagnetic wave absorbing film with polarization plane dependency and a method for satisfactorily manufacturing this one- dimensional orientation electromagnetic wave absorbing film. SOLUTION: In a one-dimensional orientation electromagnetic wave absorbing film 10, electromagnetic wave absorbing fibers 12 are orientated in an almost fixed direction. Thus, electromagnetic waves having the plane of polarization in parallel to the oriented direction of the electromagnetic wave absorbing fibers 12 can be efficiently absorbed, and the one- dimensional orientation electromagnetic wave absorbing film 10 can be provided with polarization plane dependency. Also, in manufacturing the one-dimensional orientation electromagnetic wave absorbing film 10, a plurality of columnar mixed medium columns are formed from mixed media 14 in a melted state into which the electromagnetic wave absorbing fibers 12 are mixed through a multiple nozzle or the like, and the plurality of mixed media columns are coagulated and linked so as to be arranged in parallel without any clearance. In this case, the mixed medium columns are formed so as to be thinner than the length of the electromagnetic wave absorbing fibers 12 so that all the electromagnetic wave absorbing fibers 12 can be oriented in an almost fixed direction, and that the one-dimensional orientation electromagnetic wave absorbing film 10 can be satisfactorily manufactured.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a one-dimensionally oriented electromagnetic wave absorbing film in which electromagnetic wave absorbing fibers are oriented in a substantially constant direction, a method for producing a one-dimensionally oriented electromagnetic wave absorbing film, and a method using the one-dimensionally oriented electromagnetic wave absorbing film. Related to an electromagnetic wave absorber.

[0002]

2. Description of the Related Art In an electromagnetic wave absorber, for example, an electromagnetic wave absorbing fiber (carbon fiber, etc.) having conductivity and absorbing electromagnetic waves is mixed with a mixed medium (epoxy, polyurethane, etc.).
There is an electromagnetic wave absorber manufactured by being mixed into the electromagnetic wave absorber. Such an electromagnetic wave absorber is configured to have an electromagnetic wave absorbing function by absorbing incoming electromagnetic waves by electromagnetic wave absorbing fibers.

Here, in general, the more the plane of polarization of electromagnetic waves arriving at the electromagnetic wave absorber (the plane along the direction of arrival of the electromagnetic waves and the direction of the electric field) is parallel to the direction of orientation of the electromagnetic wave absorbing fibers, the more the electromagnetic wave absorbing fibers become electromagnetic waves. On the other hand, the more the plane of polarization of the electromagnetic wave arriving at the electromagnetic wave absorber is perpendicular to the orientation direction of the electromagnetic wave absorbing fiber, the more the electromagnetic wave absorbing fiber transmits the electromagnetic wave.

However, in such an electromagnetic wave absorber, it is not possible to control the orientation of the electromagnetic wave absorbing fibers, so that the electromagnetic wave absorbing fibers are mixed in a state of being oriented in an arbitrary direction (random direction). Therefore, there is a problem that such an electromagnetic wave absorber cannot be provided with a property of efficiently absorbing an electromagnetic wave having a polarization plane in a specific direction (hereinafter referred to as “polarization plane dependence”).

Further, since the electromagnetic wave absorbing fibers can be mixed with the electromagnetic wave absorbing material only at a substantially constant density, the electromagnetic wave reflecting surface which reflects the electromagnetic waves by partially increasing the mixing density of the electromagnetic wave absorbing fibers. Cannot be formed. For this reason, there is also a problem that the electromagnetic wave absorber cannot have a function of absorbing the electromagnetic wave because the electromagnetic waves reflected by the surface on the electromagnetic wave arrival side and the electromagnetic wave reflecting surface interfere with each other and cancel each other.

In general, a so-called divided conductive film (a plurality of conductor pieces are substantially perpendicular to the plane of polarization of the electromagnetic wave) is provided on the side of the electromagnetic wave reflection surface on the side where the electromagnetic wave comes from (between the surface of the electromagnetic wave absorber on the side of the electromagnetic wave arrival side and the electromagnetic wave reflection surface). , A large phase change with respect to the electromagnetic wave can be brought about on both sides of the divided conductive film, whereby the thickness of the electromagnetic wave absorber can be reduced. However, in the electromagnetic wave absorber, since the electromagnetic wave absorbing fibers cannot be oriented in a substantially constant direction, a divided conductive film cannot be formed by the electromagnetic wave absorbing fibers, and therefore, the electromagnetic wave absorbing material cannot be thinned. There's a problem.

[0007]

SUMMARY OF THE INVENTION The present invention has been made in consideration of the above facts, and has been made in consideration of the above-mentioned facts, and a one-dimensionally oriented electromagnetic wave absorbing film having polarization plane dependency, a good method for manufacturing the one-dimensionally oriented electromagnetic wave absorbing film, and a one-dimensionally oriented electromagnetic wave absorbing film. An object is to obtain electromagnetic wave absorbers of various thicknesses using an electromagnetic wave absorbing film.

[0008]

The one-dimensionally oriented electromagnetic wave absorbing film according to claim 1 is formed in a fibrous state, and is a state in which electromagnetic wave absorbing fibers having conductivity and absorbing electromagnetic waves are oriented in a substantially constant direction. Is mixed with the mixed medium and provided in a planar manner.

In the one-dimensionally oriented electromagnetic wave absorbing film according to the first aspect, the electromagnetic wave absorbing fibers are oriented in a substantially constant direction. Therefore, it is possible to efficiently absorb electromagnetic waves having a polarization plane parallel to the orientation direction of the electromagnetic wave absorbing fiber,
This one-dimensionally oriented electromagnetic wave absorbing film can have polarization plane dependency.

According to a second aspect of the present invention, there is provided the method for producing a one-dimensionally oriented electromagnetic wave absorbing film, wherein the mixing medium is formed in a state where the electromagnetic wave absorbing fibers which are made of fibrous and have conductivity and absorb electromagnetic waves are oriented in a substantially constant direction. In the method of manufacturing a one-dimensionally oriented electromagnetic wave absorbing film provided in a plane by mixing the electromagnetic wave absorbing fibers into the molten mixed medium, the mixed medium is formed into a columnar shape thinner than the length of the electromagnetic wave absorbing fibers. Are provided, and the plurality of mixed medium pillars are solidified and connected in a state where the plurality of mixed medium pillars are arranged in parallel without gaps.

In the method for manufacturing a one-dimensionally oriented electromagnetic wave absorbing film according to a second aspect, first, a plurality of columnar mixed medium columns are formed using a mixed medium in a molten state into which electromagnetic wave absorbing fibers are mixed. Here, since the mixed medium column is formed in a column shape smaller than the length of the electromagnetic wave absorbing fiber, all the electromagnetic wave absorbing fibers in the mixed medium column are substantially parallel to the longitudinal direction of the mixed medium column.

Further, the plurality of mixed medium columns are coagulated and connected in a state where they are arranged in parallel without gaps, thereby producing a one-dimensionally oriented electromagnetic wave absorbing film. For this reason, the electromagnetic wave absorbing fibers in the one-dimensionally oriented electromagnetic wave absorbing film are all oriented in a substantially constant direction (a direction substantially parallel to the longitudinal direction of the mixing medium column). Thereby, a one-dimensionally oriented electromagnetic wave absorbing film can be favorably manufactured.

According to a third aspect of the present invention, there is provided a method of manufacturing a one-dimensionally oriented electromagnetic wave absorbing film according to the second aspect, wherein the mixed medium column has the electromagnetic wave absorbing fiber therein. It is characterized by having a viscosity or surface tension capable of being confined.

In the method for manufacturing a one-dimensionally oriented electromagnetic wave absorbing film according to the third aspect, since the mixing medium column has a viscosity or surface tension capable of confining the electromagnetic wave absorbing fiber inside, the electromagnetic wave in the mixing medium column is The absorbing fibers can be reliably made substantially parallel to the longitudinal direction of the mixed medium column. Thereby, the electromagnetic wave absorbing fibers in the one-dimensionally oriented electromagnetic wave absorbing film can be reliably oriented in a substantially constant direction, and a highly reliable one-dimensionally oriented electromagnetic wave absorbing film can be manufactured.

According to a fourth aspect of the present invention, there is provided an electromagnetic wave absorber which is formed into a fibrous shape and has a conductivity in which electromagnetic wave absorbing fibers which absorb electromagnetic waves are mixed in a mixing medium in a state of being oriented in a substantially constant direction. An electromagnetic wave absorber provided by laminating a plurality of one-dimensionally oriented electromagnetic wave absorbing films provided in the, the orientation direction of the electromagnetic wave absorbing fibers in the plurality of one-dimensionally oriented electromagnetic wave absorbing film is the same as each other, Features.

In the electromagnetic wave absorber according to the fourth aspect, since a plurality of one-dimensionally oriented electromagnetic wave absorption films are provided in a laminated manner, electromagnetic wave absorbers having various thicknesses can be obtained.

Here, since the orientation directions of the electromagnetic wave absorbing fibers in the plurality of one-dimensionally oriented electromagnetic wave absorbing films are the same, electromagnetic waves having a plane of polarization parallel to the orientation direction of the electromagnetic wave absorbing fibers can be more efficiently used. The electromagnetic wave absorber can have good polarization plane dependency.

According to a fifth aspect of the present invention, there is provided an electromagnetic wave absorber which is formed into a fibrous shape and has a conductivity in which the electromagnetic wave absorbing fiber which absorbs the electromagnetic wave is mixed in the mixing medium in a state of being oriented in a substantially constant direction. An electromagnetic wave absorber provided by laminating a plurality of one-dimensionally oriented electromagnetic wave absorbing films provided in, wherein the orientation directions of the electromagnetic wave absorbing fibers in the plurality of one-dimensionally oriented electromagnetic wave absorbing films are different from each other. Features.

In the electromagnetic wave absorber according to the fifth aspect, since a plurality of one-dimensionally oriented electromagnetic wave absorbing films are provided in a laminated manner, electromagnetic wave absorbers of various thicknesses can be obtained.

Here, since the orientation directions of the electromagnetic wave absorbing fibers in the plurality of one-dimensionally oriented electromagnetic wave absorbing films are different from each other, the electromagnetic wave absorbing fibers are oriented in various directions in this electromagnetic wave absorber. For this reason, the electromagnetic wave absorber can efficiently absorb a plurality of types of electromagnetic waves having different polarization plane directions.

According to a sixth aspect of the present invention, in the electromagnetic wave absorber according to the fourth or fifth aspect, the electromagnetic wave absorbing fiber is provided between the pair of the one-dimensionally oriented electromagnetic wave absorbing films adjacent to each other. An electromagnetic wave reflecting surface that reflects an electromagnetic wave by making the mixed concentration in the mixed medium or the conductivity of the electromagnetic wave absorbing fiber different from each other is formed, and the electromagnetic wave reflected by the electromagnetic wave arriving surface and the electromagnetic wave reflecting surface interfere with each other. It is characterized by absorbing electromagnetic waves by canceling each other out.

In the electromagnetic wave absorber according to the present invention, the concentration of the electromagnetic wave absorbing fibers mixed into the mixing medium or the conductivity of the electromagnetic wave absorbing fibers differs between a pair of one-dimensionally oriented electromagnetic wave absorbing films adjacent to each other. Thus, an electromagnetic wave reflecting surface that reflects electromagnetic waves can be formed on the surface where the mixing concentration or conductivity of the electromagnetic wave absorbing fiber changes. For this reason, the electromagnetic wave absorber can have an electromagnetic wave absorbing function by which the electromagnetic waves reflected by the surface on the electromagnetic wave arrival side and the electromagnetic wave reflecting surface interfere with each other and cancel each other.

When the electromagnetic wave reflected by the electromagnetic wave reflecting surface is reflected again by the surface of the electromagnetic wave absorber on the side where the electromagnetic wave comes, the surface of the electromagnetic wave absorber passes through the surface of the electromagnetic wave absorber on the side where the electromagnetic wave comes. Electromagnetic waves that have entered the interior of the electromagnetic wave absorber can be attenuated by being reflected a plurality of times between the surface of the electromagnetic wave absorber on the electromagnetic wave arrival side and the electromagnetic wave reflecting surface, whereby the electromagnetic waves can also be absorbed.

According to a seventh aspect of the present invention, there is provided an electromagnetic wave absorber which is formed into a fibrous shape and has a conductivity in which electromagnetic wave absorbing fibers which absorb electromagnetic waves are mixed in a mixing medium in a state of being oriented in a substantially constant direction. For a predetermined number of one-dimensionally oriented electromagnetic wave absorbing films provided in a predetermined number of planarly provided mixing the mixing medium in a state where the electromagnetic wave absorbing fibers are oriented in an arbitrary direction substantially on the same plane. At least one of a two-dimensionally oriented electromagnetic wave absorbing film and a predetermined number of non-oriented electromagnetic wave absorbing solids provided three-dimensionally by being mixed in the mixing medium in a state where the electromagnetic wave absorbing fibers are oriented in an arbitrary direction, Is provided.

In the electromagnetic wave absorber according to the seventh aspect, a predetermined number of two-dimensionally oriented electromagnetic wave absorbing films in which electromagnetic wave absorbing fibers are oriented in an arbitrary direction on substantially the same plane with respect to a predetermined number of one-dimensionally oriented electromagnetic wave absorbing films. Since at least one of the film and the predetermined number of non-oriented electromagnetic wave absorbing solids in which the electromagnetic wave absorbing fibers are oriented in an arbitrary direction is provided, electromagnetic wave absorbers of various thicknesses can be obtained.

For this reason, in the electromagnetic wave absorber, the electromagnetic wave absorbing fibers are oriented in various directions, whereby the electromagnetic wave absorber efficiently absorbs a plurality of types of electromagnetic waves having different polarization plane directions. be able to.

An electromagnetic wave absorber according to an eighth aspect is the electromagnetic wave absorber according to the seventh aspect, wherein any one of the one-dimensionally oriented electromagnetic wave absorbing film, the two-dimensionally oriented electromagnetic wave absorbing film, and the non-oriented electromagnetic wave absorbing solid which are adjacent to each other. In the meantime, the concentration of the electromagnetic wave absorbing fiber mixed into the mixing medium or the conductivity of the electromagnetic wave absorbing fiber is different from each other to form an electromagnetic wave reflecting surface that reflects electromagnetic waves, and a surface on the electromagnetic wave arrival side and the electromagnetic wave reflecting surface The electromagnetic waves reflected by the electromagnetic waves interfere with each other and cancel each other, thereby absorbing the electromagnetic waves.

[0028] In the electromagnetic wave absorber according to the eighth aspect, the mixing concentration of the electromagnetic wave absorbing fiber or the conductivity between any one of the one-dimensionally oriented electromagnetic wave absorbing film, the two-dimensionally oriented electromagnetic wave absorbing film and the non-oriented electromagnetic wave absorbing solid body adjacent to each other. By making the ratios different from each other, it is possible to form an electromagnetic wave reflecting surface that reflects electromagnetic waves on a surface where the mixing concentration or the conductivity of the electromagnetic wave absorbing fiber changes. For this reason, the electromagnetic wave absorber can have an electromagnetic wave absorbing function by which the electromagnetic waves reflected by the surface on the electromagnetic wave arrival side and the electromagnetic wave reflecting surface interfere with each other and cancel each other.

When the electromagnetic wave reflected by the electromagnetic wave reflecting surface is reflected again by the surface of the electromagnetic wave absorber on the side where the electromagnetic wave comes, the light passes through the surface of the electromagnetic wave absorber on the side where the electromagnetic wave comes. Electromagnetic waves that have entered the interior of the electromagnetic wave absorber can be attenuated by being reflected a plurality of times between the surface of the electromagnetic wave absorber on the electromagnetic wave arrival side and the electromagnetic wave reflecting surface, whereby the electromagnetic waves can also be absorbed.

The electromagnetic wave absorber according to the ninth aspect is provided with an electromagnetic wave reflecting surface for reflecting the electromagnetic wave, and the electromagnetic wave reflected by the electromagnetic wave arriving surface and the electromagnetic wave reflected by the electromagnetic wave reflecting surface interfere with each other and cancel each other. In an electromagnetic wave absorber that absorbs electromagnetic waves, the electromagnetic wave absorbing fibers that are formed into fibers and have conductivity and absorb electromagnetic waves are mixed in a mixing medium in a state where they are oriented substantially perpendicular to the plane of polarization of the electromagnetic waves, and are provided in a plane. The obtained one-dimensionally oriented electromagnetic wave absorbing film is provided on an electromagnetic wave arrival side of the electromagnetic wave reflecting surface.

The electromagnetic wave absorber according to the ninth aspect has a function of absorbing the electromagnetic wave by causing the electromagnetic waves reflected by the surface on the electromagnetic wave arrival side and the electromagnetic wave reflection surface to interfere with each other and cancel each other.

Here, a one-dimensionally oriented electromagnetic wave absorbing film in which the electromagnetic wave absorbing fibers are oriented substantially perpendicular to the plane of polarization of the electromagnetic wave is provided on the electromagnetic wave arriving side of the electromagnetic wave reflecting surface. It can serve as a conductive film. Thereby, a large phase change can be brought about the electromagnetic wave on both sides of the one-dimensionally oriented electromagnetic wave absorbing film, and therefore, the electromagnetic wave absorber can be made thin.

According to a tenth aspect of the present invention, in the electromagnetic wave absorber according to any one of the fourth to ninth aspects, the mixing concentration of the electromagnetic wave absorbing fiber is gradually reduced toward the electromagnetic wave arrival side. It is characterized by being lowered.

In the electromagnetic wave absorber according to the tenth aspect, the mixing concentration of the electromagnetic wave absorbing fiber is gradually reduced toward the electromagnetic wave arrival side, so that the inside of the electromagnetic wave absorber (the surface on the electromagnetic wave arrival side and the electromagnetic wave reflection surface) The reflection of the electromagnetic wave at (between) and the electromagnetic wave absorber can be suppressed and the penetration of the electromagnetic wave into the electromagnetic wave absorber can be promoted. Thereby, the electromagnetic wave absorbing performance of the electromagnetic wave absorber can be improved.

According to an eleventh aspect of the present invention, there is provided the electromagnetic wave absorber according to any one of the sixth and eighth to tenth aspects, wherein the electromagnetic wave absorber has a fibrous shape and has conductivity. An electromagnetic wave absorbing fiber that absorbs electromagnetic waves is mixed in a mixing medium in a state oriented in a direction substantially parallel to the plane of polarization of the electromagnetic wave, and a one-dimensionally oriented electromagnetic wave absorbing film provided in a plane is provided on the surface on the electromagnetic wave arrival side. Absorbing the electromagnetic wave by reflecting and attenuating the electromagnetic wave transmitted through the oriented electromagnetic wave absorbing film and entering the inside thereof a plurality of times between the one-dimensionally oriented electromagnetic wave absorbing film and the electromagnetic wave reflecting surface, and attenuating the electromagnetic wave. .

In the electromagnetic wave absorber according to the eleventh aspect, since the electromagnetic wave absorbing fibers of the one-dimensionally oriented electromagnetic wave absorbing film provided on the surface on the electromagnetic wave arrival side are oriented substantially parallel to the polarization plane of the electromagnetic wave, The oriented electromagnetic wave absorbing film can serve as a so-called matching film.

That is, the electromagnetic waves transmitted through the one-dimensionally oriented electromagnetic wave absorbing film (the surface of the electromagnetic wave absorber on the side where the electromagnetic wave comes in) and penetrated into the electromagnetic wave absorbing body are separated by the one-dimensionally oriented electromagnetic wave absorbing film and the electromagnetic wave reflecting surface. This electromagnetic wave can be absorbed by being reflected a plurality of times and attenuated well between them. In addition, the electromagnetic wave arriving at the electromagnetic wave absorber and reflected by the one-dimensionally oriented electromagnetic wave absorbing film (the surface of the electromagnetic wave absorber on the side where the electromagnetic wave arrives) is reflected by the electromagnetic wave reflecting surface as described above, and is reflected by the one-dimensionally oriented electromagnetic wave absorber. The electromagnetic waves transmitted through the film can be absorbed by interfering with each other and canceling each other out. Thereby, the electromagnetic wave absorbing performance of the electromagnetic wave absorber can be further improved.

[0038]

FIG. 1 is a perspective view showing a one-dimensionally oriented electromagnetic wave absorbing film 10 according to an embodiment of the present invention.

The one-dimensionally oriented electromagnetic wave absorbing film 10 is provided in a plane, and has an electromagnetic wave absorbing fiber 12.
The electromagnetic wave absorbing fiber 12 is formed in a fibrous shape, has conductivity, and has a property of absorbing electromagnetic waves. As the electromagnetic wave absorbing fiber 12, for example, carbon fiber, stainless steel fiber, conductive short fiber, or the like is used, and the length of the electromagnetic wave absorbing fiber 12 is 3 mm to 20 mm.
mm. Further, the electromagnetic wave absorbing fibers 12 are mixed in the mixing medium 14 while being oriented in a substantially constant direction. The mixing medium 14 has a property that can be melted under specific conditions. As the mixing medium 14, for example, epoxy,
Resins such as polyurethane, Teflon (registered trademark), tar, silicone, wood chips, mortar, various foam materials,
Non-woven fabric, paper and sand are used. In the one-dimensionally oriented electromagnetic wave absorbing film 10, an electromagnetic wave having a plane of polarization parallel to the orientation direction of the electromagnetic wave absorbing fiber 12 is transmitted to the electromagnetic wave absorbing fiber 12.
Has a function of absorbing electromagnetic waves by absorbing efficiently.

As a method of manufacturing the one-dimensionally oriented electromagnetic wave absorbing film 10, first, the electromagnetic wave absorbing fibers 12 are uniformly mixed into a molten mixed medium 14, and as shown in FIG. By injecting into the base 18 through the spout 16 shaped like a letter, a mixed medium column 14A having a column shape smaller than the length of the electromagnetic wave absorbing fiber 12 is formed. Further, by repeating the same operation a plurality of times, a plurality of mixed medium columns 14A are arranged in parallel on the base 18 without any gap, and thereafter, the plurality of mixed medium columns 14A are solidified (eg, dried). By being connected to each other,
The one-dimensionally oriented electromagnetic wave absorbing film 10 is manufactured. Here, since the mixed medium column 14A is formed in a column shape smaller than the length of the electromagnetic wave absorbing fiber 12, all the electromagnetic wave absorbing fibers 12 in the mixed medium column 14A are substantially parallel to the longitudinal direction of the mixed medium column 14A. Thereby, the electromagnetic wave absorbing fibers 12 in the one-dimensionally oriented electromagnetic wave absorbing film 10 are all in a substantially constant direction (a direction substantially parallel to the longitudinal direction of the mixed medium column 14A).
Is oriented. Further, the mixing medium column 14A has a viscosity or a surface tension capable of confining the electromagnetic wave absorbing fiber 12 inside, whereby the electromagnetic wave absorbing fiber 12 in the mixing medium column 14A is surely secured in the longitudinal direction of the mixing medium column 14A. Are substantially parallel to.

Further, the one-dimensionally oriented electromagnetic wave absorbing film 1
Another manufacturing method is as follows.
4, the electromagnetic wave absorbing fiber 12 is uniformly mixed, and as shown in FIG. 3, the mixed medium 14 is simultaneously passed through a plurality of multiple nozzles 20 provided with a plurality of cylindrical nozzles 20A connected in parallel. By injecting the mixture into the base 18, a plurality of mixed medium columns 14A similar to the above are arranged in parallel on the base 18 without any gap. Then, the one-dimensionally oriented electromagnetic wave absorbing film 10 is manufactured by coagulating (drying, etc.) the plurality of mixed medium columns 14A and connecting them together. Also,
Even in this case, the mixed medium column 14A is
Has a viscosity or surface tension capable of confining the inside.

FIG. 4 is a perspective view showing the two-dimensionally oriented electromagnetic wave absorbing film 22.

The two-dimensionally oriented electromagnetic wave absorbing film 22 is provided in a plane, and has the same electromagnetic wave absorbing fiber 12 as described above. The electromagnetic wave absorbing fiber 12 is oriented in an arbitrary direction on the substantially same plane, and the same mixed medium 14 as described above.
Is mixed in. In the two-dimensionally oriented electromagnetic wave absorbing film 22, the electromagnetic wave arriving from a direction perpendicular to the plane of the two-dimensionally oriented electromagnetic wave absorbing film 22 is transmitted to the electromagnetic wave absorbing fiber 12.
Has a function of absorbing electromagnetic waves by absorbing efficiently.

The method of manufacturing the two-dimensionally oriented electromagnetic wave absorbing film 22 is as follows. First, the electromagnetic wave absorbing fibers 12 are uniformly mixed into the molten mixed medium 14, and the mixed medium 14 is placed on a base 18 similar to the above. By injecting, the mixed medium 14
Is formed into a film thinner than the length of the electromagnetic wave absorbing fiber 12 to form a mixed medium film. Thereafter, the mixed medium film is coagulated (eg, dried) to produce the two-dimensionally oriented electromagnetic wave absorbing film 22. Here, since the mixed medium film is formed into a thin film having a thickness smaller than the length of the electromagnetic wave absorbing fiber 12, all the electromagnetic wave absorbing fibers 12 in the mixed medium film are substantially parallel to the surface direction of the mixed medium film. The electromagnetic wave absorbing fibers 12 in the oriented electromagnetic wave absorbing film 22 are oriented in an arbitrary direction on a substantially same plane (a direction substantially parallel to the plane direction of the mixed medium film). Further, the mixed medium film has a viscosity or a surface tension capable of confining the electromagnetic wave absorbing fiber 12 therein, thereby ensuring that the electromagnetic wave absorbing fiber 12 in the mixed medium film is substantially parallel to the plane direction of the mixed medium film. It is said.

FIG. 5 is a perspective view showing the non-oriented electromagnetic wave absorbing solid 24.

The non-oriented electromagnetic wave absorbing solid 24 is provided three-dimensionally and has the same electromagnetic wave absorbing fiber 12 as described above. The electromagnetic wave absorbing fibers 12 are mixed in the same mixing medium 14 as described above in a state of being oriented in an arbitrary direction. The non-oriented electromagnetic wave absorbing solid 24 has a function of absorbing the electromagnetic wave by absorbing the incoming electromagnetic wave by the electromagnetic wave absorbing fiber 12.

As a method of manufacturing the non-oriented electromagnetic wave absorbing solid 24, first, the electromagnetic wave absorbing fibers 12 are uniformly mixed into the molten mixed medium 14, and the mixed medium 14 is solidified (drying, etc.) in this state. Thus, the non-oriented electromagnetic wave absorbing solid 24 is manufactured.

FIG. 6 is a perspective view in which the electromagnetic wave absorber 26 provided by using the one-dimensionally oriented electromagnetic wave absorbing film 10 is partially broken.

The electromagnetic wave absorber 26 is provided by laminating a plurality of the one-dimensionally oriented electromagnetic wave absorbing films 10. Here, in the electromagnetic wave absorber 26, the electromagnetic wave absorbing fibers 12 in the plurality of one-dimensionally oriented electromagnetic wave absorbing films 10 and the electromagnetic wave absorbing fibers 12 in the plurality of one-dimensionally oriented electromagnetic wave absorbing films 10 are the same. Have different orientation directions.

Further, in the electromagnetic wave absorber 26, the one-dimensionally oriented electromagnetic wave absorbing film 10 arranged on the surface on the anti-electromagnetic wave arrival side has a role as an electromagnetic wave reflecting layer (hereinafter, this one-dimensionally oriented electromagnetic wave absorbing layer). The absorbing film 10 is referred to as “electromagnetic wave reflecting layer 28”). That is, the electromagnetic wave reflection layer 2
8, the orientation direction of the electromagnetic wave absorbing fiber 12 is substantially parallel to the plane of polarization of the electromagnetic wave, and the mixing concentration of the electromagnetic wave absorbing fiber 12 is extremely increased in the electromagnetic wave reflecting layer 28 with respect to the adjacent one-dimensionally oriented electromagnetic wave absorbing film 10. Or, the electromagnetic wave absorbing fiber 12 having a high conductivity is mixed therein, so that the electromagnetic wave reflecting layer 28 reflects the electromagnetic wave on the electromagnetic wave reflecting surface 28A. For this reason, the electromagnetic wave absorber 26 has a function of absorbing the electromagnetic wave by arriving electromagnetic waves being reflected by the surface 26A on the electromagnetic wave arrival side and the electromagnetic wave reflecting surface 28A and interfering with each other and canceling each other.

In the electromagnetic wave absorber 26, the concentration of the electromagnetic wave absorbing fiber 12 mixed therein is gradually reduced toward the electromagnetic wave arrival side.
(The surface 26A on the electromagnetic wave arrival side and the electromagnetic wave reflection surface 28)
A), the reflection of the electromagnetic wave is suppressed, and the penetration of the electromagnetic wave into the electromagnetic wave absorber 26 is promoted.

Further, in the electromagnetic wave absorber 26, the one-dimensionally oriented electromagnetic wave absorbing film 10 disposed on the surface on the side from which the electromagnetic wave arrives has a role as a so-called matching layer (hereinafter, this one-dimensionally oriented electromagnetic wave absorbing film). The film 10 is referred to as “matching layer 30”). That is, in the matching layer 30, the orientation direction of the electromagnetic wave absorbing fibers 12 is substantially parallel to the plane of polarization of the electromagnetic wave, so that the electromagnetic waves that have passed through the matching layer 30 and entered the inside of the electromagnetic wave absorber 26 are subjected to this matching. This electromagnetic wave is absorbed by being well reflected and attenuated a plurality of times between the layer 30 and the electromagnetic wave reflecting surface 28A.

As shown in detail in FIG. 7, in the electromagnetic wave absorber 26, the matching layer 30 and the electromagnetic wave reflecting layer 28
A predetermined number (usually four or less) of the one-dimensionally oriented electromagnetic wave absorbing films 10 disposed between them may be configured to serve as a so-called divided conductive film. "Divided conductive film 31"). That is, in the divided conductive film 31, the orientation direction of the electromagnetic wave absorbing fibers 12 is substantially perpendicular to the plane of polarization of the electromagnetic wave, whereby a large phase change can be brought about the electromagnetic wave on both sides of the divided conductive film 31.

As a method of manufacturing the electromagnetic wave absorber 26, a one-dimensionally oriented electromagnetic wave absorbing film 10 (a plurality of mixed medium columns 14A are solidified and connected to each other) is placed on the one-dimensionally oriented electromagnetic wave absorbing film 10. By laminating the one-dimensionally oriented electromagnetic wave absorbing film 10 by the same method as the manufacturing method (see FIGS. 2 and 3), the electromagnetic wave absorber 2
6 is manufactured (for example, see FIG. 8).

FIG. 9 is a perspective view in which the electromagnetic wave absorber 32 provided using the one-dimensionally oriented electromagnetic wave absorbing film 10 is partially broken.

The electromagnetic wave absorber 32 is composed of a predetermined number of the one-dimensionally oriented electromagnetic wave absorbing films 10 and a predetermined number of the two-dimensionally oriented electromagnetic wave absorbing films 22 and a predetermined number of the non-oriented electromagnetic wave absorbing solids 24. They are provided in combination (only one of the predetermined number of two-dimensionally oriented electromagnetic wave absorbing films 22 and the predetermined number of non-oriented electromagnetic wave absorbing solids 24 may be combined).

Further, in the electromagnetic wave absorber 32, any one of the one-dimensionally oriented electromagnetic wave absorbing film 10, the two-dimensionally oriented electromagnetic wave absorbing film 22, and the non-oriented electromagnetic wave absorbing solid 24 (FIG. 9) In this example, the one-dimensionally oriented electromagnetic wave absorbing film 10) has a role as an electromagnetic wave reflecting layer (hereinafter, this layer is referred to as an "electromagnetic wave reflecting layer 34"). That is, the electromagnetic wave reflection layer 34 is formed on any one of the adjacent one-dimensionally oriented electromagnetic wave absorbing film 10, the two-dimensionally oriented electromagnetic wave absorbing film 22, and the non-oriented electromagnetic wave absorbing solid 24.
In this case, the mixing concentration of the electromagnetic wave absorbing fiber 12 is extremely increased or the electromagnetic wave absorbing fiber 12 having a high conductivity is mixed (when the electromagnetic wave reflecting layer 34 is the one-dimensionally oriented electromagnetic wave absorbing film 10, The orientation direction of the absorbing fibers 12 is substantially parallel to the plane of polarization of the electromagnetic wave), whereby the electromagnetic wave reflecting layer 34 reflects the electromagnetic wave on the electromagnetic wave reflecting surface 34A. Therefore, the electromagnetic wave absorber 32 has a function of absorbing an electromagnetic wave by arriving electromagnetic waves being reflected by the surface 32A on the electromagnetic wave arrival side and the electromagnetic wave reflecting surface 34A and interfering with each other and canceling each other.

Further, in the electromagnetic wave absorber 32, the concentration of the electromagnetic wave absorbing fiber 12 mixed gradually decreases toward the electromagnetic wave arrival side.
(Electromagnetic wave arrival side surface 32A and electromagnetic wave reflection surface A
) Is suppressed, and the penetration of the electromagnetic wave into the electromagnetic wave absorber 32 is promoted.

Further, in the electromagnetic wave absorber 32, the one-dimensionally oriented electromagnetic wave absorbing film 10 is disposed on the surface on the side from which the electromagnetic wave has arrived.
Has a role as a so-called matching layer (hereinafter, this layer is referred to as a “matching layer 36”). That is, in the matching layer 36, the orientation direction of the electromagnetic wave absorbing fibers 12 is substantially parallel to the plane of polarization of the electromagnetic wave, so that the electromagnetic waves that have passed through the matching layer 36 and entered the inside of the electromagnetic wave absorber 32 can be matched. This electromagnetic wave is absorbed by being well reflected and attenuated a plurality of times between the layer 36 and the electromagnetic wave reflecting surface 34A.

In this electromagnetic wave absorber 32,
A predetermined number (usually four or less) of one-dimensionally oriented electromagnetic wave absorbing film 1 disposed between matching layer 36 and electromagnetic wave reflecting layer 34
0 may serve as a so-called divided conductive film (hereinafter, this one-dimensionally oriented electromagnetic wave absorbing film 10
Is referred to as “divided conductive film 38”). That is, in the divided conductive film 38, the orientation direction of the electromagnetic wave absorbing fiber 12 is substantially perpendicular to the plane of polarization of the electromagnetic wave.
8 can produce a large phase change for the electromagnetic wave (see FIG. 7).

The method for producing the electromagnetic wave absorber 32 is the same as the method for producing the one-dimensionally oriented electromagnetic wave absorbing film 10 (see FIGS. 2 and 3), the method for producing the two-dimensionally oriented electromagnetic wave absorbing film 22, and the method for producing the two-dimensionally oriented electromagnetic wave absorbing film 22. By sequentially laminating the one-dimensionally oriented electromagnetic wave absorbing film 10, the two-dimensionally oriented electromagnetic wave absorbing film 22, and the non-oriented electromagnetic wave absorbing solid 24 in the same manner and in the same manner as the method for producing the non-oriented electromagnetic wave absorbing solid 24, electromagnetic wave absorption is achieved. The body 32 is manufactured.

Next, the operation of the present embodiment will be described.

As shown in FIG. 1, in the one-dimensionally oriented electromagnetic wave absorbing film 10, the electromagnetic wave absorbing fibers 12 are oriented in a substantially constant direction. Therefore, it is possible to efficiently absorb an electromagnetic wave having a polarization plane parallel to the orientation direction of the electromagnetic wave absorbing fiber 12,
Thereby, the one-dimensionally oriented electromagnetic wave absorbing film 10 can have polarization plane dependency.

As shown in FIG. 2 or FIG. 3, in the production of the one-dimensionally oriented electromagnetic wave absorbing film 10, first, a mixed medium 14 mixed with an electromagnetic wave absorbing fiber 12 in a molten state is supplied through a spout 16 or a multiple nozzle 20. Columnar mixed media column 1
4A is formed in plurality. Here, since the mixed medium column 14A is formed in a column shape smaller than the length of the electromagnetic wave absorbing fiber 12, all the electromagnetic wave absorbing fibers 12 in the mixed medium column 14A are substantially parallel to the longitudinal direction of the mixed medium column 14A. .

Further, the one-dimensionally oriented electromagnetic wave absorbing film 10 is manufactured by coagulating (drying, etc.) and connecting the plurality of mixed medium columns 14A in a state of being arranged in parallel without gaps.
For this reason, all the electromagnetic wave absorbing fibers 12 in the one-dimensionally oriented electromagnetic wave absorbing film 10 are oriented in a substantially constant direction (a direction substantially parallel to the longitudinal direction of the mixing medium column 14A). Thereby, the one-dimensionally oriented electromagnetic wave absorbing film 10 can be favorably manufactured.

Further, since the mixing medium column 14A has a viscosity or surface tension capable of confining the electromagnetic wave absorbing fiber 12 inside, the electromagnetic wave absorbing fiber 12 inside the mixing medium column 14A
Can be reliably made substantially parallel to the longitudinal direction of the mixed medium column 14A. Thereby, the electromagnetic wave absorbing fibers 12 in the one-dimensionally oriented electromagnetic wave absorbing film 10 can be surely oriented in a substantially constant direction, and a highly reliable one-dimensionally oriented electromagnetic wave absorbing film 10 can be manufactured.

As shown in FIG. 5, in the electromagnetic wave absorber 26,
Since the plurality of one-dimensionally oriented electromagnetic wave absorbing films 10 are provided in a stacked manner, the electromagnetic wave absorbers 26 having various thicknesses can be obtained.

Here, in this electromagnetic wave absorber 26,
When the orientation directions of the electromagnetic wave absorbing fibers 12 in the plurality of one-dimensionally oriented electromagnetic wave absorbing films 10 are the same, electromagnetic waves having a polarization plane parallel to the orientation direction of the electromagnetic wave absorbing fibers 12 can be absorbed more efficiently. ,
The electromagnetic wave absorber 26 can have good polarization plane dependency, and the cost can be reduced by making the electromagnetic wave absorber 26 thinner.

On the other hand, in the electromagnetic wave absorber 26, when the orientation directions of the electromagnetic wave absorbing fibers 12 in the plurality of one-dimensionally oriented electromagnetic wave absorbing films 10 are different from each other, the electromagnetic wave absorbing fibers 12 are oriented in various directions. For this reason, the electromagnetic wave absorber 26 can efficiently absorb a plurality of types of electromagnetic waves having different polarization plane directions, and the electromagnetic wave absorber 26 can be made thinner to reduce the cost. In particular, when the orientation directions of the electromagnetic wave absorbing fibers 12 in the plurality of one-dimensionally oriented electromagnetic wave absorbing films 10 are orthogonal to each other, the electromagnetic wave absorber 26 can absorb any electromagnetic wave regardless of the direction of the polarization plane.

Further, in the electromagnetic wave absorber 26, the one-dimensionally oriented electromagnetic wave absorbing film 10 disposed on the surface on the side where the anti-electromagnetic wave arrives is used as the electromagnetic wave reflecting layer 28. In the electromagnetic wave reflecting layer 28, the orientation of the electromagnetic wave absorbing fiber 12 is adjusted. The direction is substantially parallel to the plane of polarization of the electromagnetic wave, and the mixed concentration of the electromagnetic wave absorbing fiber 12 in the electromagnetic wave reflecting layer 28 with respect to the adjacent one-dimensionally oriented electromagnetic wave absorbing film 10 is extremely increased or the electromagnetic wave having a high conductivity Absorbing fiber 12 is mixed. Thereby, the electromagnetic wave reflection layer 28 is configured to reflect the electromagnetic wave on the electromagnetic wave reflection surface 28A. Therefore, the electromagnetic wave absorber 26 reflects the incoming electromagnetic wave by the surface 26A on the electromagnetic wave arrival side and the electromagnetic wave reflection surface 28A. A function of absorbing electromagnetic waves can be provided by leverage electromagnetic waves interfering with each other and canceling each other out.

Further, in the electromagnetic wave absorber 26, since the concentration of the electromagnetic wave absorbing fibers 12 gradually decreases toward the electromagnetic wave arrival side, the inside of the electromagnetic wave absorber 26 (the surface 26A on the electromagnetic wave arrival side and the electromagnetic wave reflection side). The reflection of the electromagnetic wave on the surface 28A) can be suppressed, and the penetration of the electromagnetic wave into the electromagnetic wave absorber 26 can be promoted. Thereby, the electromagnetic wave absorbing performance of the electromagnetic wave absorber 26 can be improved.

Further, in the electromagnetic wave absorber 26, the one-dimensionally oriented electromagnetic wave absorbing film 10 arranged on the surface on the side where the electromagnetic wave arrives is used as the matching layer 30, and in the matching layer 30, the orientation direction of the electromagnetic wave absorbing fibers 12 is changed. It is substantially parallel to the plane of polarization of the electromagnetic wave. As a result, the electromagnetic waves transmitted through the matching layer 30 and entering the inside of the electromagnetic wave absorber 26 are
This electromagnetic wave can be absorbed by satisfactorily reflecting and attenuating a plurality of times between the electromagnetic wave and the electromagnetic wave reflecting surface 28A.
Therefore, the electromagnetic wave absorbing performance of the electromagnetic wave absorber 26 can be further improved.

As shown in FIG. 9, in the electromagnetic wave absorber 32,
A predetermined number of two-dimensionally oriented electromagnetic wave absorbing films 22 in which electromagnetic wave absorbing fibers 12 are oriented in an arbitrary direction on substantially the same plane with respect to a predetermined number of one-dimensionally oriented electromagnetic wave absorbing films 10, and an electromagnetic wave absorbing fiber 12 in an arbitrary direction And at least one of the predetermined number of non-oriented electromagnetic wave absorbing solids 24 oriented in the same manner, so that electromagnetic wave absorbers 32 of various thicknesses can be obtained.

For this reason, in the electromagnetic wave absorber 32, the electromagnetic wave absorbing fibers 12 are oriented in various directions, so that the electromagnetic wave absorber 32 efficiently converts a plurality of types of electromagnetic waves having different polarization plane directions. And the cost can be reduced by making the electromagnetic wave absorber 32 thinner.

Further, in the electromagnetic wave absorber 32, any one of the one-dimensionally oriented electromagnetic wave absorbing film 10, the two-dimensionally oriented electromagnetic wave absorbing film 22, and the non-oriented electromagnetic wave absorbing solid 24 (FIG. 9) In FIG. 1, the one-dimensionally oriented electromagnetic wave absorbing film 10) is used as the electromagnetic wave reflecting layer 34, and the electromagnetic wave reflecting layer 34 reflects any one of the adjacent one-dimensionally oriented electromagnetic wave absorbing film 10, the two-dimensionally oriented electromagnetic wave absorbing film 22, and the non-oriented electromagnetic wave absorbing solid 24. In the layer 34, the mixing concentration of the electromagnetic wave absorbing fiber 12 is extremely increased or the electromagnetic wave absorbing fiber 12 having high conductivity is mixed. (When the electromagnetic wave reflecting layer 34 is the one-dimensionally oriented electromagnetic wave absorbing film 10, Further, the orientation direction of the electromagnetic wave absorbing fiber 12 is substantially parallel to the plane of polarization of the electromagnetic wave. Thereby, the electromagnetic wave reflecting layer 34 is configured to reflect the electromagnetic wave on the electromagnetic wave reflecting surface 34A, and therefore, the electromagnetic wave absorber 32
Thus, a function of absorbing the electromagnetic wave can be provided because the incoming electromagnetic wave is reflected by the surface 32A on the electromagnetic wave arrival side and the electromagnetic wave reflecting surface 34A, and the electromagnetic waves interfere with each other and cancel each other.

In the electromagnetic wave absorber 32, the concentration of the electromagnetic wave absorbing fibers 12 gradually decreases toward the electromagnetic wave arrival side, so that the inside of the electromagnetic wave absorber 32 (the surface 32A on the electromagnetic wave arrival side and the electromagnetic wave reflection side). The reflection of the electromagnetic wave on the surface 34A) can be suppressed, and the penetration of the electromagnetic wave into the electromagnetic wave absorber 32 can be promoted. Thereby, the electromagnetic wave absorbing performance of the electromagnetic wave absorber 32 can be improved.

Further, in the electromagnetic wave absorber 32, the one-dimensionally oriented electromagnetic wave absorbing film 10 arranged on the surface on the side where the electromagnetic wave arrives is used as the matching layer 36. In the matching layer 36, the orientation direction of the electromagnetic wave absorbing fiber 12 is changed. It is substantially parallel to the plane of polarization of the electromagnetic wave. As a result, the electromagnetic wave transmitted through the matching layer 36 and entering the inside of the electromagnetic wave absorber 32 is
This electromagnetic wave can be absorbed by satisfactorily reflecting and attenuating a plurality of times between the electromagnetic wave and the electromagnetic wave reflecting surface 34A.
Therefore, the electromagnetic wave absorbing performance of the electromagnetic wave absorber 32 can be further improved.

As shown in detail in FIG. 7, the electromagnetic wave absorber 26
The one-dimensionally oriented electromagnetic wave absorbing film 10 disposed between the matching layer 30 and the electromagnetic wave reflecting layer 28 and between the matching layer 36 and the electromagnetic wave reflecting layer 34 of the electromagnetic wave absorber 32 is divided into conductive films 31.
Or the divided conductive film 38 (a film in which the orientation direction of the electromagnetic wave absorbing fiber 12 is substantially perpendicular to the plane of polarization of the electromagnetic wave), the electromagnetic wave is applied to both sides of the divided conductive film 31 and the divided conductive film 38. On the other hand, a large phase change can be brought about. Thereby, the electromagnetic wave absorber 26 and the electromagnetic wave absorber 32 can be thinned.

In the present embodiment, the one-dimensionally oriented electromagnetic wave absorbing film 10 is manufactured by using the spout 16 and the multiple nozzles 20, but the method of manufacturing the one-dimensionally oriented electromagnetic wave absorbing film 10 is as follows. It is not limited.
For example, first, the electromagnetic wave absorbing fibers 12 are uniformly mixed into the melted mixed medium 14, and the mixed medium 14 is injected onto a base 18 (see FIGS. 2 and 3) similar to the above, whereby the mixed medium is mixed. The mixed medium film is formed by making the film thinner than the length of the electromagnetic wave absorbing fiber 12. Further, the mixed medium film is scratched in parallel with an interval shorter than the length of the electromagnetic wave absorbing fiber 12 by, for example, a thin rod or the like, so that all the electromagnetic wave absorbing fibers 12 in the mixed medium film are oriented in a substantially constant direction. State. Thereafter, the one-dimensionally oriented electromagnetic wave absorbing film 10 can be manufactured by solidifying (drying, etc.) the mixed medium film.

In this embodiment, the electromagnetic wave absorber 2
6, an electromagnetic wave reflecting surface 28A is formed, and the electromagnetic wave absorbing member 32 is formed with an electromagnetic wave reflecting surface 34A.
The electromagnetic wave reflecting surface may be formed of a metal film or the like that reflects electromagnetic waves on the electromagnetic wave absorber. The electromagnetic wave absorber configured as described above can also have an electromagnetic wave absorbing function by causing the electromagnetic waves reflected by the surface on the electromagnetic wave arrival side and the electromagnetic wave reflecting surface to interfere with each other and cancel each other.

Furthermore, in the present embodiment, the one-dimensionally oriented electromagnetic wave absorbing film 10 is arranged on the surface of the electromagnetic wave absorber 32 on the side from which the electromagnetic wave comes, so as to form the matching layer 36.
The two-dimensionally oriented electromagnetic wave absorbing film 22 or the non-oriented electromagnetic wave absorbing solid 24 may be disposed on the surface of the electromagnetic wave absorber 32 on the electromagnetic wave arrival side to form a matching layer. In this case, the two-dimensionally oriented electromagnetic wave absorbing film 22 or the non-oriented electromagnetic wave absorbing solid 24 inside the electromagnetic wave absorbing fiber 12 that is substantially parallel to the plane of polarization of the electromagnetic wave is used. Oriented electromagnetic wave absorbing solid 2
4 can serve as a matching layer.

[0082]

In the one-dimensionally oriented electromagnetic wave absorbing film according to the first aspect, since the electromagnetic wave absorbing fibers are oriented in a substantially constant direction, the electromagnetic wave having a plane of polarization parallel to the direction of orientation of the electromagnetic wave absorbing fibers can be efficiently used. And polarization plane dependency can be provided.

In the method for manufacturing a one-dimensionally oriented electromagnetic wave absorbing film according to the second aspect, since the mixed medium column is formed into a column shape smaller than the length of the electromagnetic wave absorbing fiber, all the electromagnetic wave absorbing fibers in the mixed medium column are mixed. It is substantially parallel to the longitudinal direction of the medium column. In addition, since a plurality of mixed medium columns are coagulated and connected in a state where they are arranged in parallel without gaps, the electromagnetic wave absorbing fibers are all oriented in a substantially constant direction, so that a one-dimensionally oriented electromagnetic wave absorbing film can be favorably manufactured. Can be.

According to the method for manufacturing a one-dimensionally oriented electromagnetic wave absorbing film according to the third aspect, the electromagnetic wave absorbing fibers in the mixed medium column can be reliably made substantially parallel to the longitudinal direction of the mixed medium column, and high reliability is achieved. A one-dimensionally oriented electromagnetic wave absorbing film can be manufactured.

In the electromagnetic wave absorber according to the fourth aspect, since a plurality of one-dimensionally oriented electromagnetic wave absorption films are provided so as to be laminated, electromagnetic wave absorbers having various thicknesses can be obtained. Further, since the orientation directions of the electromagnetic wave absorbing fibers in the plurality of one-dimensionally oriented electromagnetic wave absorbing films are the same, good polarization plane dependency can be provided.

In the electromagnetic wave absorber according to the fifth aspect, since a plurality of one-dimensionally oriented electromagnetic wave absorption films are provided so as to be laminated, electromagnetic wave absorbers having various thicknesses can be obtained. Further, since the orientation directions of the electromagnetic wave absorbing fibers in the plurality of one-dimensionally oriented electromagnetic wave absorbing films are different from each other, the electromagnetic wave absorber can efficiently absorb a plurality of types of electromagnetic waves having different polarization plane directions.

In the electromagnetic wave absorber according to the sixth aspect, an electromagnetic wave reflecting surface is provided by making the mixed concentration or conductivity of the electromagnetic wave absorbing fiber different between a pair of one-dimensionally oriented electromagnetic wave absorbing films adjacent to each other. Can be. Therefore, an electromagnetic wave absorbing function can be provided in which the electromagnetic waves reflected by the surface of the electromagnetic wave absorber on the electromagnetic wave arrival side and the electromagnetic wave reflecting surface interfere with each other and cancel each other.

In the electromagnetic wave absorber according to claim 7, at least one of a predetermined number of two-dimensionally oriented electromagnetic wave absorbing films and a predetermined number of non-oriented electromagnetic wave absorbing solids is provided for a predetermined number of one-dimensionally oriented electromagnetic wave absorbing films. Are provided in combination, so that electromagnetic wave absorbers of various thicknesses can be obtained. Therefore, it is possible to efficiently absorb a plurality of types of electromagnetic waves having different polarization plane directions.

In the electromagnetic wave absorber according to the eighth aspect, the mixing concentration or the conductivity of the electromagnetic wave absorbing fiber is in any one of the one-dimensionally oriented electromagnetic wave absorbing film, the two-dimensionally oriented electromagnetic wave absorbing film and the non-oriented electromagnetic wave absorbing solid which are adjacent to each other. By making the rates different from each other, an electromagnetic wave reflecting surface can be provided. Therefore, an electromagnetic wave absorbing function can be provided in which the electromagnetic waves reflected by the surface of the electromagnetic wave absorber on the electromagnetic wave arrival side and the electromagnetic wave reflecting surface interfere with each other and cancel each other.

In the electromagnetic wave absorber according to the ninth aspect, the one-dimensionally oriented electromagnetic wave absorption film disposed on the side of the electromagnetic wave reflection surface where the electromagnetic wave comes from serves as a so-called divided conductive film. Can be.

In the electromagnetic wave absorber according to the tenth aspect, the concentration of the electromagnetic wave absorbing fiber is gradually lowered toward the electromagnetic wave arrival side, so that the reflection of the electromagnetic wave inside the electromagnetic wave absorber can be suppressed, The electromagnetic wave absorption performance of the absorber can be improved.

In the electromagnetic wave absorber according to the eleventh aspect, the one-dimensionally oriented electromagnetic wave absorbing film provided on the surface on the electromagnetic wave arrival side serves as a matching film. The electromagnetic wave absorption performance can be further improved by satisfactorily reflecting and attenuating the electromagnetic wave a plurality of times.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a one-dimensionally oriented electromagnetic wave absorbing film according to an embodiment of the present invention.

FIG. 2 is a perspective view illustrating a method for manufacturing a one-dimensionally oriented electromagnetic wave absorbing film.

FIG. 3 is a perspective view showing another example of a method for manufacturing a one-dimensionally oriented electromagnetic wave absorbing film.

FIG. 4 is a perspective view showing a two-dimensionally oriented electromagnetic wave absorbing film.

FIG. 5 is a perspective view showing a non-oriented electromagnetic wave absorbing solid.

FIG. 6 is a perspective view showing an electromagnetic wave absorber provided with a plurality of one-dimensionally oriented electromagnetic wave absorbing films laminated.

FIG. 7 is a cross-sectional view showing an electromagnetic wave reflection surface, a matching layer, and a divided conductive film.

FIG. 8 is a perspective view showing a method of manufacturing an electromagnetic wave absorber provided with a plurality of one-dimensionally oriented electromagnetic wave absorbing films laminated.

FIG. 9 is a perspective view showing an electromagnetic wave absorber provided by combining a one-dimensionally oriented electromagnetic wave absorbing film, a two-dimensionally oriented electromagnetic wave absorbing film, and a non-oriented electromagnetic wave absorbing solid.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 One-dimensionally-oriented electromagnetic-wave-absorbing film 12 Electromagnetic-wave-absorbing fiber 14 Mixed medium 14A Mixed-media column 22 Two-dimensionally-oriented electromagnetic-wave-absorbing film 24 Non-oriented electromagnetic-wave-absorbing three-dimensional 26 Electromagnetic-wave-absorber 26A Surface 28A Electromagnetic-wave-reflection surface 30 Matching layer 31 Split conductive film 32 Electromagnetic wave Absorber 32A Surface 34A Electromagnetic wave reflecting surface 36 Matching layer 38 Divided conductive film

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H01Q 17/00 H01Q 17/00 (72) Inventor Toshio Saito 1-5-1, Otsuka, Inzai City, Chiba Pref. Inside the Takenaka Corporation Technical Research Institute (72) Inventor Takeshi Kunishima 8-21-1, Ginza, Chuo-ku, Tokyo Inside the company Takenaka Road (72) Kenichi Yoshimura 8-2-1-1, Ginza, Chuo-ku, Tokyo F-term in Takenaka Road Co., Ltd. (Reference) 4F072 AA02 AB10 AB11 AD23 AD37 AD43 AD47 AK05 AL00 4F100 AB04 AD11 AK18 AK51 AK52 AK53 AP00 BA02 BA03 BA04 BA05 BA10A BA10C BA10D BA10E BA13 BA22 DG01A DG01G01 DG01G01 DG01G01 DG01G JG01D JG01E 4J002 AA001 AG001 CD001 CK001 CP031 DA016 DA086 FA046 FD016 GR01 5E321 BB25 BB41 BB44 GG05 GG12 5J020 BD02 EA03 EA07 EA10

Claims (11)

[Claims] 1. A one-dimensionally oriented electromagnetic wave absorber provided in a planar manner by mixing an electromagnetic wave absorbing fiber which is fibrous and has conductivity and absorbs electromagnetic waves in a mixed medium in a state of being oriented in a substantially constant direction. the film. 2. A one-dimensionally oriented electromagnetic wave absorber provided in a planar manner by mixing an electromagnetic wave absorbing fiber which is fibrous and has conductivity and absorbs an electromagnetic wave in a mixing medium while being oriented in a substantially constant direction. In the method for producing a film, the electromagnetic wave absorbing fiber is mixed with the mixed medium that has been melted, and a plurality of mixed medium columns formed by forming the mixed medium into a column shape smaller than the length of the electromagnetic wave absorbing fiber are provided; A method for producing a one-dimensionally oriented electromagnetic wave absorbing film, wherein the plurality of mixed medium columns are solidified and connected in a state where the mixed medium columns are arranged in parallel without gaps. 3. The method for producing a one-dimensionally oriented electromagnetic wave absorbing film according to claim 2, wherein said mixed medium column has a viscosity or a surface tension capable of confining said electromagnetic wave absorbing fiber inside. 4. A one-dimensionally oriented electromagnetic wave absorber provided in a plane by mixing an electromagnetic wave absorbing fiber which is fibrous and has conductivity and absorbs electromagnetic waves in a mixed medium in a state of being oriented in a substantially constant direction. An electromagnetic wave absorber provided by laminating a plurality of films, wherein the orientation directions of the electromagnetic wave absorbing fibers in the plurality of one-dimensionally oriented electromagnetic wave absorbing films are the same as each other. 5. A one-dimensionally oriented electromagnetic wave absorber provided in a planar manner by mixing an electromagnetic wave absorbing fiber which is fibrous and has conductivity and absorbs an electromagnetic wave in a mixed medium in a state of being oriented in a substantially constant direction. An electromagnetic wave absorber provided by laminating a plurality of films, wherein the orientation directions of the electromagnetic wave absorbing fibers in the plurality of one-dimensionally oriented electromagnetic wave absorbing films are different from each other. 6. An electromagnetic wave that reflects an electromagnetic wave by making the concentration of the electromagnetic wave absorbing fiber mixed into the mixing medium or the conductivity of the electromagnetic wave absorbing fiber different between a pair of the one-dimensionally oriented electromagnetic wave absorbing films adjacent to each other. The electromagnetic wave according to claim 4, wherein a reflection surface is formed, and the surface on the electromagnetic wave arrival side and the electromagnetic wave reflected by the electromagnetic wave reflection surface interfere with each other and cancel each other to absorb the electromagnetic wave. Absorber. 7. A predetermined number of one-dimensionally provided one-dimensionally provided by mixing an electromagnetic wave absorbing fiber having a fibrous shape and having conductivity and absorbing an electromagnetic wave into a mixing medium while being oriented in a substantially constant direction. For the oriented electromagnetic wave absorbing film, a predetermined number of two-dimensionally oriented electromagnetic wave absorbing films provided in a plane by mixing the electromagnetic wave absorbing fibers in the mixing medium in a state of being oriented in an arbitrary direction substantially on the same plane; An electromagnetic wave absorber provided by combining at least one of: a predetermined number of non-oriented electromagnetic wave absorbing solids which are mixed in the mixing medium in a state where the electromagnetic wave absorbing fibers are oriented in an arbitrary direction and are provided in a three-dimensional manner. 8. The concentration of the electromagnetic wave absorbing fibers in the mixing medium or the electromagnetic wave absorption between any one of the one-dimensionally oriented electromagnetic wave absorbing film, the two-dimensionally oriented electromagnetic wave absorbing film, and the non-oriented electromagnetic wave absorbing solid body adjacent to each other. Forming an electromagnetic wave reflection surface that reflects electromagnetic waves by making the conductivity of the fibers different from each other, and absorbs the electromagnetic waves by interfering with each other and canceling out the electromagnetic waves reflected by the electromagnetic wave arrival surface and the electromagnetic wave reflection surface; The electromagnetic wave absorber according to claim 7, characterized in that: 9. An electromagnetic wave absorber provided with an electromagnetic wave reflecting surface for reflecting an electromagnetic wave, wherein the surface on the electromagnetic wave arrival side and the electromagnetic waves reflected by the electromagnetic wave reflecting surface interfere with each other and cancel each other, thereby absorbing the electromagnetic wave. A one-dimensionally oriented electromagnetic wave absorbing film provided in a plane by mixing electromagnetic wave absorbing fibers which are shaped and conductive and absorb electromagnetic waves in a mixed medium while being oriented substantially perpendicular to the plane of polarization of the electromagnetic waves. An electromagnetic wave absorber provided on an electromagnetic wave arrival side of the electromagnetic wave reflection surface. 10. The electromagnetic wave absorber according to claim 4, wherein the mixed concentration of the electromagnetic wave absorbing fibers is gradually reduced toward the electromagnetic wave arrival side. An electromagnetic wave absorbing fiber, which is fibrous and has conductivity and absorbs electromagnetic waves, is mixed with a mixing medium in a state of being oriented substantially parallel to the plane of polarization of the electromagnetic waves, and is provided in a planar manner. An original oriented electromagnetic wave absorbing film is provided on the surface on the side where electromagnetic waves arrive, and electromagnetic waves transmitted through the one-dimensionally oriented electromagnetic wave absorbing film and entering the interior are reflected multiple times between the one-dimensionally oriented electromagnetic wave absorbing film and the electromagnetic wave reflecting surface. The electromagnetic wave is absorbed by attenuating the electromagnetic wave.
The electromagnetic wave absorber according to any one of the above.