JP6973080B2 - How to use the electromagnetic wave absorption laminate, housing and electromagnetic wave absorption laminate - Google Patents

Description

The present invention relates to an electromagnetic wave absorbing laminate, a housing, and a method of using the electromagnetic wave absorbing laminated body.

In recent years, with the development and spread of information and communication technology such as the Internet, the use of electromagnetic waves is being considered not only for communication devices such as personal computers and mobile phones, but also for various electronic devices that have not used electromagnetic waves so far. It has become like that. At the same time, for electronic devices that use electromagnetic waves, various inconveniences such as malfunction, malfunction, and failure of the electronic devices caused by the influence of electromagnetic noise emitted from other electronic devices may occur. Numerous studies have been made to curb it. In particular, various reports have been made on electromagnetic wave absorbers.

As a technique related to such an electromagnetic wave absorber, for example, there are the following techniques.

Patent Document 1 describes, as a useful technique for absorbing a wide band of electromagnetic waves, an electromagnetic wave absorber having a flat plate-shaped electromagnetic wave absorption band composed of a laminated body of two or more layers formed of a material containing thin layer graphite. It has been disclosed.

Patent Document 2 describes, as a technique for improving electromagnetic wave absorption performance in a low frequency band, a dielectric layer made of a matrix containing an electromagnetic wave absorbing material having a peak frequency of 6.4 GHz or less, and one surface of the dielectric layer. Between the laminated split conductive film layer, the electromagnetic wave reflection layer laminated on the other surface of the dielectric layer, and the dielectric layer and the split conductive film layer, the facing surfaces of the dielectric layer and the split conductive film layer. Disclosed is an electromagnetic wave absorber having a resin layer that joins the two to each other.

Japanese Unexamined Patent Publication No. 2015-23036 Japanese Unexamined Patent Publication No. 2013-201359

However, even if the present inventors house the electronic device in the housing made of the conventional electromagnetic wave absorber described in Patent Document 1, Patent Document 2, etc., the electronic device housed in the housing still remains. Various inconveniences caused by electromagnetic noise such as malfunction, malfunction, and failure may occur. Therefore, the present inventors have diligently investigated the factors that cause the above-mentioned inconvenience due to the conventional electromagnetic wave absorber. As a result, it has been found that the electromagnetic wave transmitted through the housing (electromagnetic wave absorber) without being absorbed may affect the malfunction, malfunction or failure of the electronic device. Further, the present inventor also described above when the electromagnetic wave emitted by the electronic device itself housed in the housing is reflected by the electromagnetic wave absorber constituting the housing and is taken into the electronic device as electromagnetic wave noise. It was found that the above inconvenience may occur.

Therefore, the present invention provides an electromagnetic wave absorbing laminate having both good electromagnetic wave shielding properties and good electromagnetic wave absorbing properties, a housing, and a method of using the electromagnetic wave absorbing laminated body.

As a result of diligent research to achieve the above problems, the present inventor has found that it is effective as a design guideline to have a laminated structure capable of absorbing incident electromagnetic waves in a plurality of times. Obtained and completed the present invention.

According to the present invention, a magnetic material layer formed of a first resin material containing a thermosetting resin and particles and / or fibers made of a magnetic metal.
It has a thermosetting resin and a conductive material layer formed of a second resin material including a conductive material.
When the electromagnetic wave reflection amount of the magnetic material layer is Ra and the electromagnetic wave reflection amount of the conductive material layer is Rb, an electromagnetic wave absorption laminate satisfying the relationship of Ra ≦ Rb is provided.

Further, according to the present invention, there is provided a housing made of the electromagnetic wave absorbing laminate.

Further, according to the present invention, the step of preparing the electromagnetic wave absorbing laminate and
The process of covering the surface of the electronic device with the electromagnetic wave absorbing laminate and
A method of using the electromagnetic wave absorbing laminate including the above is provided.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to provide an electromagnetic wave absorbing laminate having both good electromagnetic wave shielding property and good electromagnetic wave absorbing property, a housing, and a method of using the electromagnetic wave absorbing laminated body.

FIG. 1 is a cross-sectional view schematically showing an example of an electromagnetic wave absorbing laminate according to the present embodiment. 2A and 2B are diagrams for explaining how to use the electromagnetic wave absorbing laminate according to the present embodiment. 3A and 3B are diagrams for explaining how to use the electromagnetic wave absorbing laminate according to the present embodiment. FIG. 4 is a perspective view schematically showing an example of the paper machine according to the present embodiment. FIG. 5 is a cross-sectional view schematically showing an example of the electromagnetic wave absorbing laminate according to the present embodiment. 6 (a) to 6 (c) are cross-sectional views schematically showing an example of a method for manufacturing a papermaking body according to the present embodiment.

Hereinafter, the method of using the electromagnetic wave absorbing laminate, the housing, and the electromagnetic wave absorbing laminated body of the present invention will be described based on the preferred embodiments shown in the accompanying drawings.

<Electromagnetic wave absorption laminate>
FIG. 1 is a cross-sectional view schematically showing an example of an electromagnetic wave absorbing laminate according to the present embodiment. 2A and 2B are diagrams for explaining how to use the electromagnetic wave absorbing laminate according to the present embodiment. 3A and 3B are diagrams for explaining how to use the electromagnetic wave absorbing laminate according to the present embodiment. FIG. 4 is a perspective view schematically showing an example of the paper machine according to the present embodiment. Further, FIG. 5 is a cross-sectional view schematically showing an example of the electromagnetic wave absorbing laminate according to the present embodiment.

The electromagnetic wave absorption laminated body 150 (hereinafter, also referred to as the present laminated body 150) according to the present embodiment is used to cover the surface of the electronic device (electronic device) 50. The present laminate 150 includes a magnetic material layer 100 formed of a first resin material containing a thermosetting resin, particles and / or fibers made of a magnetic metal, a thermosetting resin, and a conductive material. It has a conductive material layer 200 formed of a second resin material including the above. The relationship between the magnetic material layer 100 and the conductive material layer 200 in the laminated body 150 is Ra ≦ Rb when the electromagnetic wave reflection amount of the magnetic material layer 100 is Ra and the electromagnetic wave reflection amount of the conductive material layer 200 is Rb. Meet. By satisfying the above relationship between the magnetic material layer 100 and the conductive material layer 200, it is possible to realize the electromagnetic wave absorbing laminated body 150 having both good electromagnetic wave shielding property and good electromagnetic wave absorbing property. It is assumed that the laminated body 150 shields electromagnetic waves having a frequency of 5 GHz or more and 18 GHz or less.
Here, the magnetic metal refers to a metal material capable of absorbing electromagnetic waves in terms of both magnetism and conductivity.

Even if an electronic device is housed in a housing made of a conventional electromagnetic wave absorber, various inconveniences caused by electromagnetic noise such as malfunction, malfunction, and failure of the electronic device housed in the housing still remain. May occur. As a result of diligent studies by the present inventors on the cause of this, the above-mentioned inconveniences are caused by the trace amount of electromagnetic waves transmitted through the housing (electromagnetic wave absorber) and the trace amount of electromagnetic waves emitted from the electronic device itself and reflected by the housing. I found that it may be a factor. According to the knowledge obtained by the present inventor, in the conventional electromagnetic wave absorber, about 40% of the electromagnetic wave emitted by the electronic device is not absorbed and is transmitted through the electromagnetic wave absorber. Or it was mostly reflected.

The electromagnetic wave absorbing laminated body 150 according to the present embodiment can solve the above-mentioned inconvenience related to the conventional electromagnetic wave absorbing material by adopting a laminated structure capable of absorbing the incident electromagnetic wave in a plurality of times. The present inventor has focused on the fact that an electromagnetic wave is a wave that propagates in space while both electric and magnetic fields oscillate alternately. The laminated body 150 has a laminated structure including a conductive material layer 200 containing a magnetic metal that functions as a conductive material and a magnetic material layer 100 that contains a magnetic metal that functions as a magnetic material. The magnetic metal that functions as a conductive material has a heat generating mechanism that converts the current flowing when the electric field is applied into heat energy. Further, the magnetic metal functioning as a magnetic material has a heat generating mechanism that converts the current flowing when the magnetic field is applied into thermal energy. That is, the laminated body 150 includes a layer that absorbs electromagnetic waves from the viewpoint of an electric field and a layer that absorbs electromagnetic waves from the viewpoint of a magnetic field. Therefore, the electromagnetic wave absorbing laminate 150 according to the present embodiment has excellent electromagnetic wave absorbing property as compared with the conventional electromagnetic wave absorbing material.

Further, it is generally known that a conductive material layer containing a magnetic metal that functions as a conductive material is superior in electromagnetic wave reflectivity to a magnetic material layer containing a magnetic metal that functions as a magnetic material. Based on these circumstances, according to the laminated body 150 according to the present embodiment, not only the electromagnetic wave absorption from the two viewpoints of the electric field and the magnetic field, but also one of the layers is once transmitted to the other layer. It is possible to absorb even electromagnetic waves that have been reflected and incident again. As a result, the electromagnetic wave absorbing laminate 150 according to the present embodiment has not only excellent electromagnetic wave absorbing property but also excellent electromagnetic wave shielding property as compared with the conventional electromagnetic wave absorbing material.

First, a method of using the electromagnetic wave absorbing laminate 150 according to the present embodiment will be described.

Here, when the main laminated body 150 is used, first, the above-mentioned main laminated body 150 is prepared. Next, the surface of the desired electronic device 50 is covered with the prepared laminate 150. At this time, the laminated body 150 may be a housing processed to a size capable of accommodating the electronic device 50, or may be processed into a sheet shape for attachment to the surface of the electronic device 50. ..

Hereinafter, a method of using the laminated body 150 will be described with reference to FIGS. 2 and 3 by taking as an example a case where the laminated body 150 is processed into a housing.

The laminated body 150 shown in FIG. 2A is a magnetic material of the conductive material layer 200 in order to protect the electronic device 50 housed in the housing from electromagnetic waves generated from the electronic device 50 arranged outside the housing. The surface opposite to the layer 100 is arranged so as to face the surface of the electronic device 50 housed in the housing. That is, in the present laminated body 150 shown in FIG. 2A, the conductive material layer 200 is arranged so as to face the surface of the electronic device 50. In this case, as shown in FIG. 2B, the laminated body 150 can absorb the electromagnetic wave emitted by the electronic device 50 outside the housing in at least three stages. Specifically, first, the magnetic material layer 100 absorbs electromagnetic waves from the viewpoint of the magnetic field (first absorption, (1) in FIG. 2 (b)). Next, the electromagnetic wave transmitted through the magnetic material layer 100 without being absorbed by the magnetic material layer 100 is absorbed by the conductive material layer 200 from the viewpoint of the electric field (second absorption, (2) of FIG. 2 (b)). After that, the electromagnetic wave reflected on the conductive material layer 200 and re-entered on the magnetic material layer 100 is absorbed again from the viewpoint of the magnetic field (third absorption, (3) in FIG. 2 (b)). By doing so, when the frequency of the electromagnetic wave is 5 GHz or more and 18 GHz or less, it is possible to cut at least 99% or more of the electromagnetic waves emitted by the electronic device 50 outside the housing. Specifically, due to the configuration of the laminated body 150, it is possible to absorb 80% or more of the total amount of electromagnetic waves emitted by the electronic device 50 outside the housing, and most of the residual electromagnetic waves that could not be absorbed are also absorbed. It is possible to reflect without transmitting.

Further, the laminated body 150 shown in FIG. 3A is a conductive material of the magnetic material layer 100 in order to prevent the electronic device 50 from being damaged by electromagnetic waves emitted by the electronic device 50 itself housed in the housing. The surface opposite to the layer 200 is arranged so as to face the surface of the electronic device 50 housed in the housing. That is, in the present laminated body 150 shown in FIG. 3A, the magnetic material layer 100 is arranged so as to face the surface of the electronic device 50. In this case, as shown in FIG. 3B, the laminated body 150 can absorb the electromagnetic wave emitted by the electronic device 50 in at least three stages. Specifically, first, the magnetic material layer 100 absorbs electromagnetic waves from the viewpoint of the magnetic field (first absorption, (1) in FIG. 3 (b)). Next, the electromagnetic wave transmitted through the magnetic material layer 100 without being absorbed by the magnetic material layer 100 is absorbed by the conductive material layer 200 from the viewpoint of the electric field (second absorption, (2) of FIG. 3 (b)). After that, the electromagnetic wave reflected on the conductive material layer 200 and re-entered on the magnetic material layer 100 is absorbed again from the viewpoint of the magnetic field (third absorption, (3) in FIG. 3 (b)). By doing so, when the frequency of the electromagnetic wave is 5 GHz or more and 18 GHz or less, it is possible to cut at least 99% or more of the electromagnetic waves emitted by the electronic device 50 housed in the housing. Specifically, with the configuration of the laminated body 150, it is possible to absorb 80% or more of the total amount of electromagnetic waves emitted by the electronic device 50, and most of the residual electromagnetic waves that could not be absorbed are not transmitted. It is possible to reflect.

Based on the above, it is preferable that the laminated body 150 has a laminated structure in which the conductive material layer 200, the magnetic material layer 100, and the conductive material layer 200 are laminated in this order at least three layers or more. By doing so, the electrons housed in the housing by both the electromagnetic waves emitted by the electronic device 50 arranged outside the housing and the electromagnetic waves emitted by the electronic device 50 itself housed in the housing. It is possible to prevent the device 50 from failing.

Here, specific examples of the electronic device 50 according to the present case include a mobile phone, a personal computer, a television, a housing having a wireless LAN function (about 5 GHz), an in-vehicle sensor, and the like. Further, according to the present laminated body 150, not only the type of the electronic device 50 but also an electromagnetic wave having a frequency of 5 GHz or more and 18 GHz or less can achieve both good electromagnetic wave shielding property and electromagnetic wave absorption property.

Next, the configuration of the electromagnetic wave absorbing laminated body 150 according to the present embodiment assuming that it is used by any of the above-mentioned methods will be described. Here, it is preferable that both the conductive material layer 200 and the magnetic material layer 100 constituting the laminated body 150 are layers obtained by molding a papermaking body made of a resin material forming each layer. In the present laminated body 150, only one of the conductive material layer 200 and the magnetic material layer 100 may be a layer obtained by molding a papermaking body.

Here, the papermaking body is generally used as a technical term indicating the state of a product obtained by using a method of straining a fiber material. This state is described in, for example, Japanese Patent No. 4675276 and Japanese Patent No. 5426399. According to the document, the paper is described as referring to a wet solid content remaining on a filter after dehydration of a liquid component from a raw material slurry in which raw materials such as fibers and resins are dispersed in a dispersion medium. ing. The wet state referred to here means a cured state before drying and heat treatment, that is, a cured state before post-cure. Further, according to the same document, the papermaking body is used for a molded body obtained by heating and drying molding in a molding mold. That is, it is stated that the abstract is used as a molding material.

Hereinafter, the present laminated body 150 will be described in detail by taking as an example a case where both the conductive material layer 200 and the magnetic material layer 100 are layers obtained by molding a papermaking body. That is, the present laminated body 150, which will be described later, has a laminated structure made of a molded product obtained by molding such a papermaking body by, for example, a heat-pressing press treatment or the like. The papermaking body may be in the form of a sheet, or may be in the form of a raw form processed into a shape imitating a desired molded product shape.

First, the above-mentioned papermaking body will be described with reference to FIG.
In FIG. 4, an enlarged view of the region shown by the dotted line in the papermaking body is shown. The papermaking body 10 according to the present embodiment includes a binder resin A and a fiber material (filler) B. Further, the fiber material B is preferably oriented in the plane direction of the papermaking body 10 as shown in FIG. 4 from the viewpoint of improving the electromagnetic wave shielding property of the papermaking body 10. In other words, the fiber material (filler) B is randomly oriented when viewed from the in-plane direction of the paper machine 10, while the plane of the paper machine 10 when viewed from the thickness direction of the paper machine 10. It is preferably oriented in the direction. In the present specification, the fact that the fiber material B is oriented in the plane direction of the papermaking body 10 means that the majority of the fiber material B is oriented in the plane direction of the papermaking body 10, and all the fiber materials. B does not have to be oriented in the plane direction of the papermaking body 10. For example, 90% or more of the fiber material B may be oriented in the plane direction of the papermaking body 10. In addition to the fibrous material, the "fiber material" in the present specification also includes non-spherical materials such as flat and needle-shaped materials. When a flat material (flat filler) is used as the fiber material B, the flat filler is oriented so that its thick wall direction is substantially parallel to the plane direction of the papermaking body 10.

Further, the binder resin A contained in the papermaking body 10 functions as a binder for binding the fiber materials (fillers) B to each other, and also as a molding material for forming the papermaking body 10 into a molded body by a subsequent heat treatment. Function. The binder resin A in the papermaking body 10 is in a state where it is not completely cured, for example, in a B stage state. By heating the abstract 10 at the curing temperature of the binder resin A to be used, it can be deformed into another shape, and the binder resin A can be completely cured to obtain a molded body. The papermaking body 10 is used as a molding material for manufacturing a molded body.

The papermaking body 10 according to the present embodiment is obtained by the papermaking method described later, and has structural features A to C in the following points.
(Characteristic A) In the plan view of the surface of the papermaking body 10 (in the in-plane direction of the papermaking body 10), the fiber materials are randomly oriented.
(Characteristic B) In the cross-sectional view of the papermaking body 10 in the thickness direction, the orientation state of the fiber material is highly controlled, and the fiber material is oriented in a specific direction. In other words, the fiber materials are in a laminated state in the thickness direction of the papermaking body 10.
(Characteristic C) The fiber materials are bound to each other with a binder resin.

Since the papermaking body 10 according to the present embodiment is formed by the papermaking method, the fiber material (filler) B is uniformly dispersed in the papermaking body 10, and the fiber material (filler) B is appropriately entangled with each other. It is estimated that it can be made. Although it is not always clear, for these reasons, it is considered that the electromagnetic wave shielding property and the electromagnetic wave absorbing property of the electromagnetic wave absorbing laminated body 150 formed by using the papermaking body 10 can be compatible at a high level. Further, since the papermaking method is excellent in processability, the designability of the papermaking body 10 can be improved. Further, in the papermaking method, there are few restrictions on the combination of materials constituting the papermaking body 10. Therefore, various other additives can be appropriately used together with the binder resin A and the fiber material (filler) B according to the characteristics required for the electromagnetic wave absorbing laminate.

The papermaking body 10 can have, for example, a flat plate shape.
As described above, the fiber material (filler) B is oriented in the papermaking body 10 in the plane direction of the papermaking body 10. Thereby, the electromagnetic wave shielding property of the papermaking body 10 can be improved particularly in the thickness direction of the papermaking body 10. In the enlarged cross-sectional view of the paper machine 10 shown in FIG. 4 in the thickness direction, the fiber material (filler) B (B in FIG. 4) is oriented in the plane direction of the paper machine 10, and the fiber material (filler) B is oriented. The case where the binder resin A (A in FIG. 4) is interposed between the two is exemplified. In this case, the fiber materials (fillers) B are bound to each other by, for example, the binder resin A. By orienting the fiber material B in the plane direction of the papermaking body 10, a network structure of the fiber material B is formed, and the conductive paths are easily connected. Thereby, the electromagnetic wave shielding property of the papermaking body 10 can be further improved. Further, in the papermaking body 10, since the fiber material B is oriented in the plane direction of the papermaking body 10, even when the content of the fiber material B is small, the network structure of the fiber material B is surely formed and the papermaking body 10 is formed. The electromagnetic wave shielding property can be improved. That is, by using the papermaking body 10, the conductive material layer or the magnetic material having high electromagnetic wave shielding property while reducing the content of the fiber material B as compared with the case where the conductive material layer or the like is formed by a method other than the papermaking method. Layers can be formed.

In the enlarged plan view of the papermaking body 10 shown in FIG. 4, the case where the fiber material (filler) B is randomly arranged in the plane and is entangled with each other is exemplified. The fiber material (filler) B may have a linear shape, may be curved, or may be bent in a plan view. Further, even in a plan view, for example, a binder resin A is interposed between the fiber materials (fillers) B.

Further, in the papermaking body 10, the angle formed by the longitudinal direction of the fiber material (filler) B and the surface direction of the papermaking body 10 is preferably about 0 to 10 °, more preferably about 0 to 8 °. preferable. By orienting the fiber material (filler) B so as to satisfy such conditions, the fiber material (filler) B is more uniformly laminated in the thickness direction of the papermaking body 10. In the present laminated body 150 formed by using the papermaking body 10, the electromagnetic wave shielding property and the electromagnetic wave absorbing property can be compatible at a higher level.

When both the conductive material layer 200 and the magnetic material layer 100 of the laminated body 150 are layers obtained by molding the abstracted body 10 having the above-mentioned structural characteristics, the fiber material (filler) B (filler) B (filler) B (in each layer). The conductive material or magnetic material) is controlled to face a predetermined direction in the thickness direction. Therefore, it is possible to obtain the present laminated body 150 which is dramatically superior in both electromagnetic wave absorption and electromagnetic wave shielding property as compared with the case where the conductive material layer and the magnetic material layer are molded by a molded body other than the abstracted body 10. ..

Further, although the laminated body 150 shown in FIG. 1 is formed by joining the magnetic material layer 100 and the conductive material layer 200, an intermediate layer may be provided between the layers. When the magnetic material layer 100 and the conductive material layer 200 are bonded to each other in the laminated body 150, as shown in FIG. 5, the magnetic material is formed in the bonding interface region between the magnetic material layer 100 and the conductive material layer 200. It is preferable to have an intermediate layer in which the resin material forming the layer 100 and the resin material forming the conductive material layer 200 are mixed. Specifically, it is preferable that the bonding interface between the magnetic material layer 100 and the conductive material layer 200 forms a jaggies structure. By doing so, the bonding interface region between the magnetic material layer 100 and the conductive material layer 200 can be formed so as to have an apparent gradation. As a result, the difference in characteristic impedance between the resin materials forming each of the above layers can be reduced, so that the amount of electromagnetic wave reflection at the junction interface between the magnetic material layer 100 and the conductive material layer 200 in the present laminate 150 is reduced. be able to. As a result, the amount of electromagnetic waves transmitted through the magnetic material layer 100 without being absorbed by the magnetic material layer 100 reaches the conductive material layer 200, and the amount of electromagnetic waves absorbed by the conductive material layer 200 from the viewpoint of the electric field increases. It will be. Therefore, as a result, the amount of electromagnetic wave absorption itself by the laminated body 150 increases, so that the electromagnetic wave shielding performance of the laminated body 150 can be further improved. In order to form the jaggies structure, it is preferable to mold the magnetic material layer 100 and the conductive material layer 200 from the papermaking body obtained by using the papermaking method described later, respectively. More specifically, first, the papermaking body formed of the constituent materials of the magnetic material layer 100 and the conductive material layer 200 is surface-treated so as to obtain a desired jaggies structure. Next, the paper machines are laminated so that the surface side of each paper machine that has been surface-treated is in contact with each other. Then, this laminate is molded by press molding or the like to obtain an electromagnetic wave absorption laminate. Such a jaggies structure can be easily formed by laminating and molding (for example, press molding) the papermaking bodies, and is a general laminating body of a film or a laminating body obtained by coating and drying. You can't get it with your body. Further, the injection molding method and the extrusion molding method are not suitable for forming a jaggies structure because laminating is difficult.

Next, a method for manufacturing the papermaking body 10 will be described.
6 (a) to 6 (c) are cross-sectional views schematically showing an example of the manufacturing method of the papermaking body 10 according to the present embodiment.
The papermaking body 10 is manufactured, for example, by using a wet papermaking method. The method for producing a papermaking body 10 according to the present embodiment includes, for example, a step of preparing a material composition containing a binder resin A and a fiber material (filler) B by using a papermaking method. Therefore, in the following, a case where a material composition containing a thermosetting resin A and a filler B is produced will be described as an example.

First, as shown in FIG. 6A, the prepared material composition is added to the solvent, stirred and dispersed. Here, a material composition containing a thermosetting resin A, a filler B, and other additives as required is added to the solvent, stirred, and dispersed. Thereby, a varnish-like material composition for forming the papermaking body 10 can be obtained. Examples of the method of dispersing each component in a solvent include a method of stirring using a disperser. In FIG. 6, reference numeral A indicates a thermosetting resin, and reference numeral B indicates a filler.

As the solvent, it is difficult to volatilize in the process of dispersing the constituent materials of the material composition, it is easy to remove the solvent in order to suppress the residue in the abstract 10, and the energy is increased by the removal of the solvent. From the viewpoint of suppressing this, a solvent having a boiling point of 50 ° C. or higher and 200 ° C. or lower is preferable. Specific examples of such a solvent include water, alcohols such as ethanol, 1-propanol, 1-butanol, and ethylene glycol, ketones such as acetone, methyl ethyl ketone, 2-heptanone, and cyclohexanone, and ethyl acetate and acetic acid. Examples thereof include esters such as butyl, methyl acetoacetate and methyl acetoacetate, and ethers such as tetrahydrofuran, isopropyl ether, dioxane and furfural. These solvents may be used alone or in combination of two or more. Among these, it is particularly preferable to use water because of its abundant supply, low cost, low environmental load, high safety and easy handling.

In the above step of obtaining a varnish-like material composition, as the thermosetting resin A, for example, a solid state thermosetting resin having an average particle size of 500 μm or less can be used. Thereby, in the step of aggregating the material composition containing the thermosetting resin described later, it is possible to make it easier to form the aggregated state of the material composition. In the above step of obtaining a varnish-like material composition, the average particle size of the thermosetting resin is more preferably 1 nm or more and 300 μm or less. The thermosetting resin A having such an average particle size can be obtained by performing a pulverization treatment using, for example, an atomizer pulverizer or the like. For the average particle size of the thermosetting resin A, for example, a laser diffraction type particle size distribution measuring device such as SALD-7000 manufactured by Shimadzu Corporation is used to obtain a mass-based 50% particle size as the average particle size. be able to.

In the present embodiment, it is preferable to add a flocculant to the varnish-like material composition obtained above. This makes it easier to agglomerate the thermosetting resin A and the filler B in the solvent in a floc-like manner to obtain the agglomerate F.

Next, as shown in FIG. 6B, the solvent and the agglomerate F obtained above are placed in a container whose bottom surface is made of mesh 30, and the solvent is discharged from the mesh 30. As a result, the agglomerate F and the solvent can be separated from each other. At this time, the agglomerates F remain in the form of a sheet on the mesh 30. In the present embodiment, the shape of the obtained papermaking body 10 can be adjusted by appropriately selecting the shape of the mesh 30.

In the present embodiment, the sheet-shaped agglomerate F obtained above can be taken out and placed in a drying oven to be dried to further remove the solvent. In this way, the papermaking body 10 as shown in FIG. 6 (c) is manufactured.

Then, by molding the obtained papermaking body 10, a desired layer can be obtained. Here, examples of the method for molding the magnetic material layer 100 or the conductive material layer 200 according to the present embodiment include press molding and the like. Specifically, first, the papermaking body 10 is pressed with a press plate, and a hot plate is arranged on the outer peripheral side of the press plate to heat it. Thereby, a molded body constituting the magnetic material layer 100 or the conductive material layer 200 can be obtained. When the thermosetting resin A is contained in the abstract 10 as the binder resin A, the above molding step can be performed so that the thermosetting resin in the molded product is in a semi-cured state, for example. As a result, the molded body can be thermally cured after laminating the molded body on the other member, so that the molded body and the other member can be more strongly fixed to each other.

Hereinafter, the material forming the magnetic material layer 100 or the conductive material layer 200 will be described in detail.

<Resin material forming the magnetic material layer 100>
As described above, the resin material (first resin material) forming the magnetic material layer 100 includes a thermosetting resin and particles and / or fibers made of a magnetic metal. Here, when the magnetic material layer 100 is a layer formed by molding a papermaking body, the thermosetting resin functions as the binder resin A shown in FIG. Further, the particles and / or fibers made of the magnetic metal function as the filler B shown in FIG.

(Binder resin A)
As the name implies, the binder resin A acts as a binder for binding the filler B in the papermaking body. Therefore, the binder resin A may be any resin that can bind the filler B. As the binder resin A, that is, a thermosetting resin, for example, using a resin in a solid form at room temperature (25 ° C.) in a non-heated state is from the viewpoint of stably producing the papermaking body 10. preferable.

Specific examples of the thermosetting resin include phenol resin, epoxy resin, unsaturated polyester resin, melamine resin, polyurethane and the like. These may be used alone or in combination of two or more. Above all, from the viewpoint of moldability, it is preferable to contain at least one of a phenol resin and an epoxy resin.

In the present embodiment, the papermaking body for forming the magnetic material layer 100 (hereinafter, also referred to as papermaking body X) can include, for example, a thermosetting resin having a granular or powdery shape. This makes it possible to more effectively improve the mechanical properties of the cured product obtained by curing the papermaking body X. Although the reason for this is not clear, when the abstract X is heated and pressed for molding, the thermosetting resin has a granular or powdery shape, so that the impregnation property at the time of melting is improved, and the filler B and the heat It is presumed that the interface with the curable resin is well formed. In the present embodiment, for example, by making a thermosetting resin which is a powder or granular material and a filler B to produce a papermaking body X, a papermaking containing a thermosetting resin having a granular or powdery shape is produced. It is possible to realize the body X.

The thermosetting resin having a granular or powdery shape can include, for example, a resin having an average particle size of 500 μm or less. From the viewpoint of more effectively improving the mechanical properties of the cured product obtained by curing the abstract X, the average particle size of the thermosetting resin having a granular or powdery shape is 1 nm or more and 300 μm or less. Is more preferable. A thermosetting resin having such an average particle size can be obtained by performing a pulverization treatment using, for example, an atomizer pulverizer or the like. For the average particle size of the thermosetting resin, for example, a laser diffraction type particle size distribution measuring device such as SALD-7000 manufactured by Shimadzu Corporation shall be used to determine the 50% particle size based on the mass as the average particle size. Can be done.

The content of the thermosetting resin is preferably 5% by weight or more, more preferably 15% by weight or more, and most preferably 20% by weight or more with respect to the total amount of the papermaking body X. This makes it possible to more effectively improve the workability and lightness of the papermaking body X. On the other hand, the content of the thermosetting resin is preferably 80% by weight or less, more preferably 60% by weight or less, and most preferably 40% by weight or less with respect to the total amount of the abstract X. .. This makes it possible to more effectively improve the thermal properties of the cured product obtained by curing the papermaking body X.

(Fiber material (filler) B)
The papermaking body X according to the present embodiment contains particles or fibers made of a magnetic metal as the filler B. Here, the fiber composed of a magnetic metal may be a metal fiber composed of a single metal element or an alloy fiber composed of a plurality of metals. Such metal fibers preferably contain one or more metal elements selected from the group consisting of, for example, aluminum, silver, copper, magnesium, iron, chromium, nickel, titanium, zinc, tin, molybdenum and tungsten. .. The fibers made of magnetic metal in the present embodiment include, for example, stainless steel fibers manufactured by Nippon Seisen Co., Ltd. and Bekarto Japan Co., Ltd., copper fibers manufactured by Nijigi Co., Ltd., aluminum fibers, brass fibers, and steel. Fibers, titanium fibers, phosphor bronze fibers and the like are available as commercial products, but are not limited thereto. As the fibers made of these magnetic metals, one type may be used alone, or two or more types may be used in combination.

Further, as the fiber made of magnetic metal, in order to improve the adhesion and handleability with the fiber surface-treated with a silane coupling agent, an aluminate coupling agent, a titanate coupling agent, etc., or a resin according to the required characteristics. Fibers treated with a converging agent may be used.

The fiber length of the fiber composed of the magnetic metal is, for example, preferably 100 μm or more and 200 mm or less, more preferably 500 μm or more and 50 mm or less, and particularly preferably 500 μm or more and 10 mm or less. Further, the fiber width of the fiber made of magnetic metal is preferably, for example, 0.5 μm or more and 1 mm or less, and more preferably 3 μm or more and 100 μm or less. By setting the fiber length and fiber width of the fiber made of magnetic metal within the above ranges, it becomes easier to set the aspect ratio of the fiber made of magnetic metal within a desired range. Therefore, the strength of the present laminated body 150 obtained by molding the papermaking body X can be improved more effectively. It is also possible to contribute to the improvement of the uniform dispersibility of the filler B in the papermaking body X.

The content of the fiber made of magnetic metal is preferably 15% by weight or more, more preferably 30% by weight or more, and particularly preferably 45% by weight or more with respect to the entire papermaking body X. As a result, it is possible to more effectively improve all of the mechanical properties, the thermal properties, and the electromagnetic wave shielding properties of the molded body obtained by molding the papermaking body X. On the other hand, the content of the fiber made of magnetic metal is preferably 80% by weight or less, more preferably 70% by weight or less, and particularly preferably 65% by weight or less with respect to the entire papermaking body X. preferable. This makes it possible to improve the workability and lightness of the papermaking body X. It is also possible to more effectively improve the dispersibility of the fibers made of magnetic metal and contribute to the improvement of the mechanical properties, thermal properties, and electromagnetic wave shielding properties of the molded body obtained by molding the papermaking body X. Is.

The particles made of the magnetic metal may be particles made of a metal capable of becoming magnetic. Specific examples of such metals include metals such as Fe, Ni and Co, as well as Fe-Co alloys, Fe-Cr alloys, Fe-Ni alloys, Ni-Co alloys, Fe-Cr-Si alloys and Fe-Ni. Examples thereof include alloys such as −Mo alloys, Fe—Si alloys and Fe—Si—Al alloys. Further, examples thereof include alloys in which one or more sub-components of Al, Co, Cr, Cu, Mn, Mo, Nb, Ti and Zn are added to the above metals and alloys. Of these, alloy particles containing iron and aluminum are preferable.

Sub-components such as Al, Co, Cr, Cu, Mn, Mo, Nb, Ti and Zn contained in the particles composed of the magnetic metal are affected by a decrease in magnetic flux density when the content thereof is excessively large. Occurs. Therefore, the total amount of the sub-components is preferably 10% by mass or less, and particularly preferably 5% by mass or less. Further, as another subcomponent, trace components other than the above elements (for example, O, C, P, Mn, etc.) may be derived from the raw material of the alloy or mixed in during the manufacturing process of the alloy. It is acceptable as long as it does not interfere with the purpose. The total amount of these trace components is preferably 1% by mass or less. Examples of the shape of the particles made of magnetic metal include flat, granular, plate-like, and needle-like.

The content of the particles composed of the magnetic metal is preferably 15% by weight or more, more preferably 30% by weight or more, and particularly preferably 45% by weight or more with respect to the entire papermaking body X. .. As a result, it is possible to more effectively improve all of the mechanical properties, the thermal properties, and the electromagnetic wave shielding properties of the molded body obtained by molding the papermaking body X. On the other hand, the content of the particles composed of the magnetic metal is preferably 80% by weight or less, more preferably 70% by weight or less, and 65% by weight or less with respect to the entire papermaking body X. Is particularly preferable. This makes it possible to improve the workability and lightness of the papermaking body X. Further, it is necessary to more effectively improve the dispersibility of particles composed of magnetic metal, and to contribute to the improvement of mechanical properties, thermal properties, and electromagnetic wave shielding properties of the molded body obtained by molding the papermaking body X. Is also possible.

The filler B may contain the following fibrous fillers and other fillers having a lower aspect ratio than the fibrous fillers, depending on the required properties. Further, the fibrous filler and other fillers having a lower aspect ratio than the fibrous filler may be surface-treated with a silane coupling agent, an aluminate coupling agent, a titanate coupling agent, or the like, or may be surface-treated with a resin. It may be treated with a converging agent in order to improve the adhesion and handleability of the resin.

The fibrous fillers include inorganic fibers such as carbon fibers, glass fibers and ceramic fibers; natural fibers such as wood fibers, cotton, hemp and wool; recycled fibers such as rayon fibers; semi-synthetic fibers such as cellulose fibers; polyamide fibers. , Aramid fiber, polyimide fiber, polyvinyl alcohol fiber, polyester fiber, acrylic fiber, polyparaphenylene benzoxazole fiber, polyethylene fiber, polypropylene fiber, polyacrylonitrile fiber, ethylene vinyl alcohol fiber, etc. Can include more than seeds. Among these, from the viewpoint of improving thermal conductivity, it is preferable to contain inorganic fibers, and it is more preferable to contain carbon fibers. Further, from the viewpoint of improving mechanical properties, it is more preferable to contain one or more of synthetic fibers and inorganic fibers. Further, from the viewpoint of improving the bending strength, it is particularly preferable to contain carbon fiber. Further, from the viewpoint of improving impact resistance, it is particularly preferable to contain aramid fiber.

The aspect ratio of the fibrous filler is preferably 100 or more, more preferably 150 or more, and particularly preferably 200 or more. On the other hand, the aspect ratio of the fibrous filler is preferably 1000 or less, preferably 700 or less, from the viewpoint of improving the ease of manufacturing the papermaking body X and the strength of the cured product obtained by molding the papermaking body X. Is more preferable. The aspect ratio of the fibrous filler is determined by the fiber length / fiber width. Further, the fibrous filler in the present specification is a concept that does not include pulp C, which will be described later.

The fiber length of the fibrous filler is, for example, preferably 100 μm or more and 200 mm or less, more preferably 500 μm or more and 50 mm or less, and particularly preferably 500 μm or more and 10 mm or less. The fiber width of the fibrous filler is, for example, preferably 0.5 μm or more and 1 mm or less, and more preferably 3 μm or more and 100 μm or less. By setting the fiber length and fiber width of the fibrous filler within the above ranges, it becomes easier to set the aspect ratio of the fibrous filler within the desired range.

Another filler having a lower aspect ratio than the fibrous filler is, for example, a filler having an aspect ratio of 50 or less. By including such another filler, it is possible to entangle the other filler with the above-mentioned fibrous filler, and as a result, the mechanical strength of the obtained molded product can be improved. The aspect ratio is preferably 50 or less, more preferably 30 or less, and particularly preferably 20 or less.

The fiber length or major axis of the other filler is, for example, preferably 1 μm or more and 10 mm or less, more preferably 10 μm or more and 1 mm or less, and particularly preferably 10 μm or more and 500 μm or less. The fiber width or minor axis of the other filler is preferably, for example, 0.5 μm or more and 500 μm or less, and more preferably 1 μm or more and 100 μm or less. This makes it easier to keep the aspect ratio within the desired range. By doing so, it is possible to improve the balance between the thermal properties, the mechanical properties, and the electromagnetic wave shielding performance of the obtained molded product.

The other fillers may have various shapes depending on the required properties. In the present embodiment, at least one of a fiber material such as milled fiber or a powder or granular material can be used as the other filler.

Here, when the other fillers include a fibrous material, such other fillers are selected from the group consisting of, for example, aluminum, silver, copper, magnesium, iron, chromium, nickel, titanium, zinc, tin, molybdenum and tungsten. Metal fiber containing one or more kinds of metal elements; inorganic fiber such as carbon fiber, glass fiber, ceramic fiber; natural fiber such as wood fiber, cotton, linen, wool; recycled fiber such as rayon fiber; cellulose fiber Semi-synthetic fibers such as: polyamide fibers, aramid fibers, polyimide fibers, polyvinyl alcohol fibers, polyester fibers, acrylic fibers, polyparaphenylene benzoxazole fibers, polyethylene fibers, polypropylene fibers, polyacrylonitrile fibers, ethylene vinyl alcohol fibers and other synthetic fibers. It can contain one or more selected from. Among these, from the viewpoint of improving thermal conductivity, it is preferable to contain one or more of metal fibers and inorganic fibers, and it is more preferable to contain at least one of metal fibers and carbon fibers. .. From the viewpoint of improving the balance between mechanical properties and thermal conductivity, it is particularly preferable to contain at least carbon fibers.

When the above other fillers contain fiber materials, such other fillers are carbon materials such as, for example, graphite, carbon black, charcoal, coke, diamond, carbon nanotubes, graphene, fullerene, talc, calcined clay, unfired clay, mica. , Silicates like glass, titanium oxide, oxides like alumina, magnesium silicate, fused silica, silicon compounds like crystalline silica, carbonates like calcium carbonate, magnesium carbonate, hydrotalcite, oxidation Oxides such as zinc, magnesium oxide, aluminum hydroxide, magnesium hydroxide, hydroxides such as calcium hydroxide, barium sulfate, calcium sulfate, sulfates or sulfates such as calcium sulfite, zinc borate, metahou Includes one or more powders selected from silicates such as barium acid, aluminum borate, calcium borate, sodium borate, and nitrides such as aluminum nitride, boron nitride, silicon nitride. be able to. Among these, from the viewpoint of improving the balance between mechanical properties and thermal conductivity, it is preferable to contain a carbon material, and it is more preferable to contain at least one of graphite and carbon black.

(Pulp C)
The papermaking body X can contain, for example, pulp C. Pulp C is a fiber material having a fibril structure and can be obtained, for example, by mechanically or chemically fibrilizing the fiber material. In the method for producing a paper machine using the above-mentioned papermaking method, the thermosetting resin can be more effectively aggregated by making the pulp C together with the thermosetting resin and the filler B. This makes it possible to realize more stable production of the papermaking body X.

Examples of pulp C include cellulose fibers such as linter pulp and wood pulp, natural fibers such as kenaf, jute and bamboo, para-type total aromatic polyamide fibers (aramid fibers) and their copolymers, aromatic polyester fibers and polybenza. Examples thereof include fibrils of organic fibers such as sol fibers, meta-type aramid fibers and their copolymers, acrylic fibers, acrylonitrile fibers, polyimide fibers and polyamide fibers. Pulp C can contain one or more of these. Among these, from the viewpoint of improving the mechanical properties and electromagnetic wave shielding properties of the molded product using the papermaking body X, and from the viewpoint of improving the dispersibility of the filler B, the aramid pulp composed of the aramid fiber and the acrylonitrile fiber. It is particularly preferred to include either or both of the polyacrylonitrile pulps composed of.

The content of pulp C is preferably 0.5% by weight or more, more preferably 1.5% by weight or more, and particularly preferably 2% by weight or more, based on the total amount of the papermaking body X. As a result, it is possible to more effectively generate agglomeration of the thermosetting resin at the time of papermaking, and to realize more stable production of the papermaking body X. The content of pulp C is preferably 15% by weight or less, more preferably 10% by weight or less, and particularly preferably 8% by weight or less, based on the total amount of the paper machine X. This makes it possible to more effectively improve the mechanical properties and thermal properties of the cured product obtained by curing the papermaking body X.

(Coagulant D)
The papermaking body X can contain, for example, a flocculant D. The aggregating agent D has a function of aggregating a thermosetting resin and a fiber material in a floc shape in the method for producing a papermaking body X using the above-mentioned papermaking method. Therefore, it is possible to realize more stable production of the resin sheet.

The flocculant D can include, for example, one or more selected from a cationic polymer flocculant, an anionic polymer flocculant, a nonionic polymer flocculant, and an amphoteric polymer flocculant. Examples of such flocculant D include cationic polyacrylamide, anionic polyacrylamide, Hoffmann polyacrylamide, mannic polyacrylamide, amphoteric copolymer polyacrylamide, cationized starch, amphoteric starch, polyethylene oxide and the like. can. Further, the polymer structure, molecular weight, functional group amount such as hydroxyl group and ionic group of the flocculant D can be adjusted without particular limitation according to the required properties.

The content of the flocculant D is preferably 0.05% by weight or more, more preferably 0.1% by weight or more, and 0.15% by weight, based on the total amount of the constituent materials of the above-mentioned papermaking body X. It is particularly preferable that the weight is% by weight or more. Thereby, in the production of the papermaking body X using the papermaking method, the yield can be improved. On the other hand, the content of the flocculant D is preferably 3% by weight or less, more preferably 2% by weight or less, and 1.5% by weight, based on the total amount of the constituent materials of the above-mentioned papermaking body X. % Or less is particularly preferable. This makes it possible to more easily and stably perform dehydration treatment and the like in the production of the papermaking body X using the papermaking method.

The abstract X can contain, for example, a powdery substance having an ion exchange ability in addition to the above-mentioned components. As the powdery substance having an ion exchange ability, for example, it is preferable to use one kind or two or more kinds of interlayer compounds selected from clay minerals, scaly silica fine particles, hydrotalcites, fluorine teniolite and swellable synthetic mica. .. Examples of clay minerals include smectite, halloysite, kanemite, kenyite, zirconium phosphate, titanium phosphate and the like. Examples of hydrotalcites include hydrotalcites and hydrotalcite-like substances. Examples of the fluorine teniolite include lithium type fluorine teniolite and sodium type fluorine teniolite. Examples of the swellable synthetic mica include sodium type tetrasilicon fluorine mica, lithium type tetrasilicon fluorine mica and the like. These interlayer compounds may be natural products or synthetic compounds. Of these, clay minerals are more preferred, and smectites are more preferred in that they are present from natural products to synthetics and have a wide range of choices. Examples of smectite include montmorillonite, biderite, nontronite, saponite, hectorite, saponite, stephensite and the like, and any one or more of these can be used. Montmorillonite is a hydrous silicate of aluminum, but it may be bentonite containing montmorillonite as a main component and other minerals such as quartz, mica, feldspar, and zeolite. When used for applications where coloration or impurities are a concern, synthetic smectite (smectone) having few impurities is preferable.

Further, the abstract X is, for example, a stabilizer such as an antioxidant or an ultraviolet absorber for the purpose of improving characteristics, a mold release agent, a plastic, a flame retardant, a resin curing catalyst or curing accelerator, a pigment, and a dry paper strength. Paper strength improver such as improver, wet paper strength improver, yield improver, drainage improver, size fixing agent, defoaming agent, rosin-based sizing agent for acidic paper making, rosin-based sizing agent for neutral paper making, alkyl One selected from sizing agents such as ketendimer-based sizing agents, alkenyl succinic acid anhydride-based sizing agents, special modified rosin-based sizing agents, and additives such as sulfate bands, aluminum chloride, and coagulants such as polyaluminum chloride. Two or more kinds can be included for the purpose of adjusting production conditions and expressing required physical properties.

<Material forming the conductive material layer 200>
As described above, the resin material (second resin material) forming the conductive material layer 200 includes a thermosetting resin and a conductive material. Here, the thermosetting resin functions as the binder resin A shown in FIG. 4 when the conductive material layer 200 is a layer formed by molding a papermaking body. Next, when the conductive material layer 200 is a layer formed by molding a papermaking body, the conductive material functions as the filler B shown in FIG.

Further, as the resin material for forming the conductive material layer 200, the same material as the material for forming the magnetic material layer 100 can be used except for the filler B. In the following description, the papermaking body for forming the conductive material layer 200 is referred to as a papermaking body Y.

(Filler B)
The papermaking body Y according to the present embodiment contains a conductive material as the filler B. Examples of such a conductive material include fibers and particles formed of a material capable of being conductive. Examples of such fibers include metal fibers and carbon fibers. Specific examples of the metal material constituting the above-mentioned metal fiber include copper, stainless steel, aluminum, nickel, titanium, tungsten, tin, lead, iron, silver, chromium, carbon, and alloys thereof. Of these, alloy particles containing iron and aluminum are preferable. When the conductive material is a particle, the shape thereof includes a flat shape, a granular shape, a plate shape, a needle shape, and the like.

The conductive material according to the present embodiment is a magnetic particle processed into a flat shape from the viewpoint of achieving both a conductive effect due to the network structure of the filler B formed in the abstract Y and an electromagnetic wave absorption effect due to magnetism. (Flat magnetic particles) are preferable. As described above, the flat magnetic particles in the abstract Y are oriented so that the thickness direction thereof is substantially parallel to the plane direction of the abstract Y, whereby the conductivity of the abstract Y is improved. .. As a result, the electromagnetic wave shielding property of the conductive material layer 200 using the papermaking body Y can be further improved. The above-mentioned effect can be obtained by including the flat magnetic particles as the filler B of the papermaking body Y. In a method other than the papermaking method, it is difficult to uniformly disperse the flat magnetic particles in the molded body, so it is better to use a filler B having another shape (for example, spherical shape).

The content of the conductive material is preferably 15% by weight or more, more preferably 30% by weight or more, and particularly preferably 45% by weight or more with respect to the entire papermaking body Y. As a result, it is possible to more effectively improve any of the mechanical properties, the thermal properties, and the electromagnetic wave shielding properties of the molded body obtained by molding the papermaking body Y. On the other hand, the content of the conductive material is preferably 80% by weight or less, more preferably 70% by weight or less, and particularly preferably 65% by weight or less with respect to the entire papermaking body Y. This makes it possible to improve the workability and lightness of the papermaking body Y. It is also possible to more effectively improve the dispersibility of the conductive material and contribute to the improvement of the mechanical properties, thermal properties, and electromagnetic wave shielding properties of the molded body obtained by molding the papermaking body Y.

As the filler B, the following fibrous filler or another filler having a lower aspect ratio than the fibrous filler may be used depending on the required properties. In addition, the fibrous filler and other fillers having a lower aspect ratio than the fibrous filler may be surface-treated with a silane coupling agent, an aluminate coupling agent, a titanate coupling agent, or the like, or a resin. It may be treated with a converging agent in order to improve the adhesion with the fiber and the handleability.

The fibrous fillers include inorganic fibers such as carbon fibers, glass fibers and ceramic fibers; natural fibers such as wood fibers, cotton, hemp and wool; recycled fibers such as rayon fibers; semi-synthetic fibers such as cellulose fibers; polyamide fibers. , Aramid fiber, polyimide fiber, polyvinyl alcohol fiber, polyester fiber, acrylic fiber, polyparaphenylene benzoxazole fiber, polyethylene fiber, polypropylene fiber, polyacrylonitrile fiber, ethylene vinyl alcohol fiber, etc. Can include more than seeds. Among these, from the viewpoint of improving thermal conductivity, it is preferable to contain inorganic fibers, and it is more preferable to contain carbon fibers. Further, from the viewpoint of improving mechanical properties, it is more preferable to contain one or more of synthetic fibers and inorganic fibers. In particular, from the viewpoint of improving the bending strength, it is particularly preferable to contain carbon fiber. Further, from the viewpoint of improving impact resistance, it is particularly preferable to contain aramid fiber.

The aspect ratio of the fibrous filler is preferably 100 or more, more preferably 150 or more, and particularly preferably 200 or more. On the other hand, the aspect ratio of the fibrous filler is preferably 1000 or less, preferably 700 or less, from the viewpoint of improving the ease of manufacturing the papermaking body Y and the strength of the cured product obtained by molding the papermaking body Y. Is more preferable. The aspect ratio of the fibrous filler is determined by the fiber length / fiber width. Further, the fibrous filler in the present specification is a concept that does not contain pulp C.

The fiber length of the fibrous filler is, for example, preferably 100 μm or more and 200 mm or less, more preferably 500 μm or more and 50 mm or less, and particularly preferably 500 μm or more and 10 mm or less. The fiber width of the fibrous filler is, for example, preferably 0.5 μm or more and 1 mm or less, and more preferably 3 μm or more and 100 μm or less. By setting the fiber length and fiber width of the fibrous filler in the above ranges, it becomes easier to set the aspect ratio of the fibrous filler within a desired range.

Other fillers having an aspect ratio lower than that of the fibrous filler have, for example, an aspect ratio of 50 or less. By doing so, it is possible to entangle with the above-mentioned fibrous filler, and it is possible to improve the mechanical strength of the obtained molded product. The aspect ratio is preferably 50 or less, more preferably 30 or less, and particularly preferably 20 or less.

The fiber length or major axis of the other filler having a lower aspect ratio than the fibrous filler is preferably, for example, 1 μm or more and 10 mm or less, more preferably 10 μm or more and 1 mm or less, and 10 μm or more and 500 μm or less. Especially preferable. The fiber width or minor axis of the other filler is preferably, for example, 0.5 μm or more and 500 μm or less, and more preferably 1 μm or more and 100 μm or less. This makes it easier to keep the aspect ratio within the desired range. By doing so, it is possible to improve the balance between the thermal properties, the mechanical properties, and the electromagnetic wave shielding performance of the obtained molded product.

Other fillers having a lower aspect ratio than the fibrous filler can have various shapes depending on the required properties. In the present embodiment, at least one of a fiber material such as milled fiber or a powder or granular material can be used as the other filler.

Here, when another filler having a lower aspect ratio than the fibrous filler contains a fibrous material, the other filler may be, for example, aluminum, silver, copper, magnesium, iron, chrome, nickel, titanium, zinc, tin, etc. Metal fiber containing one or more metal elements selected from the group consisting of molybdenum and tungsten; inorganic fiber such as carbon fiber, glass fiber and ceramic fiber; natural fiber such as wood fiber, cotton, linen and wool; Recycled fiber such as rayon fiber; Semi-synthetic fiber such as cellulose fiber; Polyamide fiber, Aramid fiber, Polyimide fiber, Polyvinyl alcohol fiber, Polyester fiber, Acrylic fiber, Polyparaphenylene benzoxazole fiber, Polyethylene fiber, Polypropylene fiber, Polyacrylonitrile fiber , One or more selected from synthetic fibers such as ethylene vinyl alcohol fiber. Among these, from the viewpoint of improving thermal conductivity, it is preferable to contain one or more of metal fibers and inorganic fibers, and it is more preferable to contain at least one of metal fibers and carbon fibers. .. From the viewpoint of improving the balance between mechanical properties and thermal conductivity, it is particularly preferable to contain at least carbon fibers.

When other fillers having a lower aspect ratio than the above fibrous fillers contain fibrous materials, such other fillers include carbon materials such as graphite, carbon black, charcoal, coke, diamond, carbon nanotubes, graphene, fullerene, and talc. , Calcined clay, unfired clay, mica, silicates like glass, titanium oxide, oxides like alumina, magnesium silicate, molten silica, silicon compounds like crystalline silica, calcium carbonate, magnesium carbonate, hydro Carbonates like tarcite, oxides like zinc oxide, magnesium oxide, hydroxides like aluminum hydroxide, magnesium hydroxide, calcium hydroxide, sulfates like barium sulfate, calcium sulfate, calcium sulfite Or one selected from borosulfates, zinc borate, barium metaborate, aluminum borate, calcium borate, borates such as sodium borate, and nitrides such as aluminum nitride, boron nitride, silicon nitride or It can contain two or more kinds of powders and granules. Among these, from the viewpoint of improving the balance between mechanical properties and thermal conductivity, it is preferable to contain a carbon material, and it is more preferable to contain at least one of graphite and carbon black.

The present invention is not limited to the above-described embodiment, and modifications, improvements, and the like to the extent that the object of the present invention can be achieved are included in the present invention.

Next, examples and comparative examples of the present invention will be described.

<Example: Manufacture of a resin sheet for forming an electromagnetic wave absorbing laminate>
For each example, a resin sheet for forming an electromagnetic wave absorbing laminate was manufactured as follows.

First, a prime body used to form the magnetic material layer was produced by the following method.
The constituent material composed of the binder resin A, the filler B, and the pulp C crushed to an average particle size of 45 μm (50% particle size based on the mass) with an atomizer crusher having the blending amounts shown in Table 1 is water as a solvent. Was added to the mixture and stirred with a disperser for 30 minutes to obtain a mixture. Here, a total of 100 parts by weight of the constituent materials (binder resin A, filler B and pulp C) was added to 10,000 parts by weight of water. Next, the flocculant D previously dissolved in water was added in an amount of 1% by weight based on the total amount of the above-mentioned constituent material and the flocculant D, and the constituent material was aggregated in a floc shape. The resulting agglomerates were then separated from water by a 30 mesh metal mesh. Then, the separated agglomerates were used as a prime body used to form the magnetic material layer. When a jaggies structure is formed at the junction interface between the magnetic material layer and the conductive material layer in the electromagnetic wave absorbing laminate which is the final product, it is used to form the conductive material layer described later in the obtained elemental body. The surface to be joined to the element was surface-processed so that the desired jaggies structure could be obtained.

Next, the elemental body used for forming the conductive material layer was produced by the same method as the elemental form used for forming the magnetic material layer described above. When a jaggies structure is formed at the junction interface between the magnetic material layer and the conductive material layer in the electromagnetic wave absorbing laminate which is the final product, the elemental body used to form the magnetic material layer in the obtained elemental form. The surface to be joined with was surface-processed so as to obtain the desired jaggies structure.

Next, after laminating the two types of the obtained aggregates (aggregates), the laminate of the aggregates was dehydrated and pressed, and further placed in a dryer at 50 ° C. for 5 hours to be dried to form a composite resin composition. A resin sheet composed of materials was obtained. The yield was 97%.

<Comparative example: Manufacture of a resin sheet for forming an electromagnetic wave absorbing laminate>
For each comparative example, a resin sheet for forming an electromagnetic wave absorbing laminate was manufactured as follows.
The constituent material composed of the binder resin A, the filler B, and the pulp C crushed to an average particle size of 45 μm (50% particle size based on the mass) with an atomizer crusher having the blending amounts shown in Table 1 is water as a solvent. Was added to the mixture and stirred with a disperser for 30 minutes to obtain a mixture. Here, a total of 100 parts by weight of the constituent materials (binder resin A, filler B and pulp C) was added to 10,000 parts by weight of water. Next, the flocculant D previously dissolved in water was added in an amount of 1% by weight based on the total amount of the above-mentioned constituent material and the flocculant D, and the constituent material was aggregated in a floc shape. The resulting agglomerates were then separated from water by a 30 mesh metal mesh. Then, the agglomerates after separation were dehydrated and pressed, and further placed in a dryer at 50 ° C. for 5 hours to be dried to obtain a resin sheet composed of the composite resin composition. The yield was 97%.

For each Example and Comparative Example, it was confirmed that the filler B was oriented in the resin sheet in the plane direction of the resin sheet. The details of each component shown in Table 1 are as follows. The unit of the blending ratio of each component in Table 1 is% by weight.

(Binder resin A)
-Phenol resin: Resol resin (PR-51723, manufactured by Sumitomo Bakelite Co., Ltd.)

(Filler B)
-Aramid fiber: fiber length 3 mm, fiber width 12 μm
-Stainless steel fiber (SUS fiber): fiber length 5 mm, fiber width 10 μm
-Silicon steel spherical powder (magnetic spherical powder): manufactured by Sanyo Special Steel Co., Ltd., FM79DF6H, average particle size 50 μm
-Silicon steel flat powder (magnetic flat powder): Sanyo Special Steel Co., Ltd., FME3DH, long side 100 μm, thickness approx. 3 μm

(Pulp C)
・ Aramid pulp: Kevlar pulp 1F303 (manufactured by Toray DuPont Co., Ltd.)

(Coagulant D)
-Synthetic smectite: smecton (manufactured by Kunimine Kogyo Co., Ltd.)

<Manufacturing of electromagnetic wave absorber>
The resin sheet obtained by the above method was ^{heat-treated for 10 minutes under the conditions of a pressure of 300 kg / cm 2} and a temperature of 180 ° C. to prepare an electromagnetic wave absorber according to each Example and Comparative Example. The electromagnetic wave absorber according to the comparative example was not a laminated body having a conductive material layer and a magnetic material layer, but was composed of a single layer containing the conductive material and the magnetic material in the same layer. In Table 1 below, such a single layer is referred to as a mixed layer, and the results according to the comparative example are shown.
Further, the thickness of the conductive material layer and the magnetic material layer in the electromagnetic wave absorber of the example was 1 mm, respectively. On the other hand, the thickness of the electromagnetic wave absorber of the comparative example was 2 mm.

The following evaluations were made using the electromagnetic wave absorbers of Examples and Comparative Examples.

-Electromagnetic wave absorption amount of electromagnetic wave absorber: First, the obtained electromagnetic wave absorber was cut concentrically to prepare a test piece. Then, using the obtained test piece and a network analyzer (manufactured by Agilent Technologies), electromagnetic waves having frequencies of 5 GHz, 8 GHz, 10 GHz, 12 GHz, 14 GHz, 16 GHz and 18 GHz by the coaxial tube method (according to the IEC62333 standard). The amount of attenuation (electromagnetic wave absorption) was measured. As the coaxial tube used for such measurement, S-GPC7 (outer diameter: 6.97 mm, inner diameter: 3.05 mm) manufactured by Keycom Co., Ltd. was used. The unit of the amount of electromagnetic wave absorption is%.

-Electromagnetic wave reflection amount Ra of the magnetic material layer and electromagnetic wave reflection amount Rb of the conductive material layer: The electromagnetic wave reflection amount was measured for each of the magnetic material layer and the conductive material layer constituting the electromagnetic wave absorber of the example by the following method. ..

First, by the method described above, the elemental body used for forming the magnetic material layer and the elemental form used for forming the conductive material layer are dehydrated and pressed, respectively, without laminating, and further dried at 50 ° C. Was put in the water for 5 hours and dried to obtain a resin sheet composed of the composite resin composition. Next, the obtained resin sheet was ^{heat-treated for 10 minutes under the conditions of a pressure of 300 kg / cm 2} and a temperature of 180 ° C. to prepare a cured product. This cured product was cut concentrically to prepare a test piece. Then, using the obtained test piece and a network analyzer (manufactured by Agilent Technologies), the frequency of the test piece was 5 GHz, 8 GHz, 10 GHz, 12 GHz, 14 GHz, 16 GHz by the coaxial tube method (according to the IEC62333 standard). , The amount of reflection attenuation (electromagnetic wave reflection amount) of an electromagnetic wave of 18 GHz was determined. As the coaxial tube used for such measurement, S-GPC7 (outer diameter: 6.97 mm, inner diameter: 3.05 mm) manufactured by Keycom Co., Ltd. was used. The unit of the amount of electromagnetic wave reflection is%.

-Electromagnetic wave reflection amount Rc of the mixed layer: The above-mentioned magnetism except that a test piece obtained from a resin sheet having a thickness of 2 mm using a prime body used for forming the mixed layer produced by the above-mentioned method was used. The electromagnetic wave reflection amount Rc was obtained by the same method as the electromagnetic wave reflection amount Ra of the material layer and the electromagnetic wave reflection amount Rb of the conductive material layer.

The evaluation results for the above evaluation items are shown in Table 1 below together with the compounding composition of the conductive material layer, the magnetic material layer and the mixed layer.

The electromagnetic wave absorption laminates of the examples were all electromagnetic wave absorption laminates having both good electromagnetic wave shielding properties and good electromagnetic wave absorption properties. Therefore, when the surface of the electronic device is covered with the electromagnetic wave absorbing laminate of the embodiment as shown in FIG. 3A, it is possible to effectively suppress inconveniences such as malfunction and malfunction of the electronic device. It is thought that it can be done. On the other hand, the electromagnetic wave absorber of the comparative example was inferior in the electromagnetic wave shielding property as compared with the example. Therefore, when the surface of the electronic device is covered with the electromagnetic wave absorber of the comparative example as shown in FIG. 3A, the occurrence of inconveniences such as malfunction and malfunction of the electronic device is satisfied to the extent required. It is considered that it cannot be suppressed.

Further, the constituent materials of the magnetic material layer and the conductive material layer of Example 1 were laminated with the raw materials obtained by coating and drying, respectively, to obtain a resin sheet. Using such a resin sheet, an electromagnetic wave absorber was manufactured in the same manner as in Example 1. As a result, the electromagnetic wave absorber also had good electromagnetic wave shielding property and good electromagnetic wave absorbing property.

The electromagnetic wave absorbing laminate of the present invention comprises a magnetic material layer formed of a first resin material containing particles and / or fibers composed of a thermosetting resin and a magnetic metal, and a thermosetting resin and a conductive material. It has a conductive material layer formed of a second resin material containing. Further, in the electromagnetic wave absorbing laminate of the present invention, the electromagnetic wave reflection amount Rb of the conductive material layer and the electromagnetic wave reflection amount Ra of the magnetic material layer satisfy the relationship of Ra ≦ Rb. An electromagnetic wave absorbing laminate that satisfies these conditions can have both good electromagnetic wave shielding properties and good electromagnetic wave absorbing properties. Therefore, when the surface of the electronic device (device) is covered with the electromagnetic wave absorbing laminate, it is possible to effectively suppress the occurrence of inconveniences such as malfunction and malfunction of the electronic device. Therefore, the present invention has industrial applicability.

Claims (13)

A magnetic material layer formed of a first resin material containing a thermosetting resin and particles and / or fibers made of a magnetic metal.
It has a thermosetting resin and a conductive material layer formed of a second resin material including a conductive material.
The magnetic material layer and the conductive material layer are obtained by laminating resin sheets obtained by sheet-molding the first resin material and the second resin material, respectively, and performing heat treatment while applying pressure. A cured product of the first resin material and a cured product of the second resin material.
Said first resin material and the second resin material, respectively sheet forming alone, pressure 300 kg / cm ^2, by heat treatment for 10 minutes at a temperature of 180 ° C., the curing of the first resin material prepare the object and the cured product of the second resin material, the electromagnetic wave of a predetermined frequency frequency 5～18GHz, the cured product of said first resin material measured by coaxial tube method conforming to IEC62333 standard An electromagnetic wave absorbing laminate characterized in that the relationship of Ra <Rb is satisfied when the electromagnetic wave reflection amount is Ra and the electromagnetic wave reflection amount of the cured product of the second resin material is Rb. The electromagnetic wave absorbing laminate according to claim 1, wherein the conductive material is an alloy particle containing iron and aluminum. The electromagnetic wave absorbing laminate according to claim 1 or 2, wherein the conductive material is magnetic particles processed into a flat shape. The electromagnetic wave absorbing laminate according to any one of claims 1 to 3, wherein the particles made of the magnetic metal are alloy particles containing iron and aluminum. The invention according to any one of claims 1 to 4, wherein the thermosetting resin contains one or more selected from the group consisting of a phenol resin, an epoxy resin, an unsaturated polyester resin, a melamine resin and a polyurethane. Electromagnetic absorption laminate. The electromagnetic wave absorption laminate according to any one of claims 1 to 5, wherein the magnetic material layer and the conductive material layer are bonded to each other. The invention according to any one of claims 1 to 6, further comprising an intermediate layer in which the first resin material and the second resin material are mixed between the magnetic material layer and the conductive material layer. Electromagnetic wave absorption laminate. The electromagnetic wave absorption laminate according to any one of claims 1 to 7, wherein the magnetic material layer is composed of a papermaking body containing the first resin material. The electromagnetic wave absorption laminate according to any one of claims 1 to 8, wherein the conductive material layer is composed of a papermaking body containing the second resin material. A housing made of the electromagnetic wave absorbing laminate according to any one of claims 1 to 9. The step of preparing the electromagnetic wave absorbing laminate according to any one of claims 1 to 9, and the step of preparing the electromagnetic wave absorbing laminate.
The process of covering the surface of the electronic device with the electromagnetic wave absorbing laminate and
How to use the electromagnetic wave absorption laminate including. The use of the electromagnetic wave absorbing laminate according to claim 11, wherein the step of covering the surface of the electronic device includes a step of arranging the electromagnetic wave absorbing laminate so that the magnetic material layer faces the surface of the electronic device. Method. The step of covering the surface of the electronic device includes the step of arranging the electromagnetic wave absorbing laminate so that the conductive material layer faces the surface of the electronic device, according to claim 11. how to use.

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