TW201729994A - Electromagnetic wave absorption laminated body, case body and method of using electromagnetic wave absorption laminated body - Google Patents

Abstract

An electromagnetic wave absorption laminated body is used for covering a surface of an electronic device. The electromagnetic wave absorption laminated body includes: a magnetic material layer formed of a first resin composition containing a thermosetting resin, and particles and/or fibers which are made of a magnetic material; and a conductive material layer formed of a second resin composition containing a thermosetting resin and a conductive material, wherein when an electromagnetic wave reflection amount of the magnetic material layer is defined as "Ra" and an electromagnetic wave reflection amount of the conductive material layer is defined as "Rb", Ra and Rb satisfy a relationship of "Ra ≤ Rb". Further, the magnetic material layer is preferably constituted from a paper-making body containing the first resin composition and the conductive material layer is preferably constituted from a paper-making body containing the second resin composition.

Description

Method for using electromagnetic wave absorbing laminated body, casing and electromagnetic wave absorbing laminated body

The present invention relates to a method of using an electromagnetic wave absorbing laminate, a casing, and an electromagnetic wave absorbing laminate.

In recent years, with the development and popularization of information and communication technologies such as the Internet, research on the use of electromagnetic waves has been carried out not only for communication devices such as personal computers and mobile phones, but also for various electronic devices that have not yet utilized electromagnetic waves. At the same time, in order to suppress malfunctions, incomplete functions, and even malfunctions caused by electromagnetic wave noise emitted from other electronic devices, electronic devices using electromagnetic waves have been extensively studied. In particular, there are various reports on electromagnetic wave absorbing materials.

As a technique for such an electromagnetic wave absorbing material, for example, there are the following techniques.

Patent Document 1 discloses, as a technique for absorbing a wide-band electromagnetic wave, an electromagnetic wave absorber including a flat electromagnetic wave absorption band, which is a laminate of two or more layers formed of a material containing a thin layer of graphite. Composition.

Patent Document 2 discloses a technique for improving electromagnetic wave absorption performance in a low frequency band, and discloses an electromagnetic wave absorber comprising: a dielectric layer composed of a matrix containing an electromagnetic wave absorbing material having a peak frequency of 6.4 GHz or less; and a divided conductive film a layer laminated on one side of the dielectric layer; an electromagnetic wave reflective layer laminated on the other side of the dielectric layer; and a resin layer between the dielectric layer and the divided conductive film layer to separate the dielectric layer from the divided conductive layer The opposite faces of the film layer are joined to each other.

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2015-23036

[Patent Document 2] Japanese Patent Laid-Open Publication No. 2013-201359

However, the present inventors have found that even if the electronic device is housed in a casing made of a conventional electromagnetic wave absorbing material described in Patent Document 1 or Patent Document 2, the electronic device housed in the casing may malfunction or function incompletely. Even a malfunction or the like is caused by various adverse conditions of electromagnetic wave noise. Therefore, the inventors of the present invention have made an effort to study the main causes of the above-mentioned adverse conditions when using a conventional electromagnetic wave absorbing material. As a result, it has been found that there is a possibility that electromagnetic waves transmitted through the casing (electromagnetic wave absorbing material) without absorption may affect the malfunction, malfunction, malfunction, and the like of the electronic device. Further, the inventors have found that electromagnetic waves emitted from the electronic device housed in the casing are reflected by the electromagnetic wave absorbing material constituting the casing and are absorbed by the electronic device as electromagnetic wave noise. The possibility of the above-mentioned adverse conditions.

Therefore, the present invention provides a good electromagnetic wave shielding property and good electrical power. A method of using a magnetic wave absorptive electromagnetic wave absorbing laminate, a casing, and the above electromagnetic wave absorbing laminate.

In order to achieve the above-mentioned problems, the inventors of the present invention have made an effort to carry out the research. As a result, it has been found that a laminated structure capable of absorbing a plurality of electromagnetic waves that have been incident multiple times is effective as a design guideline, and the present invention has been completed.

According to the invention, there is provided an electromagnetic wave absorptive laminate comprising a magnetic material layer formed of a first resin material and a conductive material layer formed of a second resin material containing a thermosetting resin and a conductive material, wherein the first resin material When the amount of electromagnetic wave reflection of the magnetic material layer is Ra and the amount of electromagnetic wave reflection of the conductive material layer is Rb, the thermosetting resin and the particles and/or fibers made of the magnetic material satisfy the Ra ≦ Rb. relationship.

Furthermore, according to the present invention, there is provided a casing comprising the electromagnetic wave absorbing laminate.

Furthermore, according to the present invention, there is provided a method of using an electromagnetic wave absorbing laminate, comprising the steps of: preparing the electromagnetic wave absorbing laminate; and coating the surface of the electronic device with the electromagnetic wave absorbing laminate.

According to the present invention, it is possible to provide an electromagnetic wave absorbing laminated body, a casing, and a method of using the electromagnetic wave absorbing laminated body which have both good electromagnetic wave shielding properties and good electromagnetic wave absorbing properties.

10‧‧‧

30‧‧30 mesh screen

50‧‧‧Electronic devices (electronic machines)

100‧‧‧ Magnetic material layer

150‧‧‧Electromagnetic wave absorption laminate (this laminate)

200‧‧‧ Conductive material layer

A‧‧‧Binder resin

B‧‧‧Fiber material (filler)

F‧‧‧Condensate

Fig. 1 is a cross-sectional view schematically showing an example of an electromagnetic wave absorptive laminate of the embodiment.

2(a) and 2(b) are views for explaining a method of using the electromagnetic wave absorptive laminate of the embodiment.

3(a) and 3(b) are views for explaining a method of using the electromagnetic wave absorptive laminate of the embodiment.

Fig. 4 is a perspective view schematically showing an example of a paper-making body of the embodiment.

Fig. 5 is a cross-sectional view schematically showing an example of an electromagnetic wave absorptive laminate of the embodiment.

6(a) to 6(c) are cross-sectional views schematically showing an example of a method for producing a paper-making body according to the embodiment.

Hereinafter, a method of using the electromagnetic wave absorptive laminate, the casing, and the electromagnetic wave absorbing laminate of the present invention will be described based on a preferred embodiment shown in the drawings.

<Electromagnetic wave absorption laminate>

Fig. 1 is a cross-sectional view schematically showing an example of an electromagnetic wave absorptive laminate of the embodiment. 2(a) and 2(b) are views for explaining a method of using the electromagnetic wave absorptive laminate of the embodiment. 3(a) and 3(b) are views for explaining a method of using the electromagnetic wave absorptive laminate of the embodiment. Fig. 4 is a perspective view schematically showing an example of a paper-making body of the embodiment. Fig. 5 is a cross-sectional view schematically showing an example of the electromagnetic wave absorptive laminate of the embodiment.

The electromagnetic wave absorptive laminate 150 of the present embodiment (hereinafter also referred to as the laminated body 150) is used to cover the surface of an electronic device (electronic device) 50. The laminated body 150 has a magnetic material layer 100 formed of a first resin material and a conductive material layer 200 formed of a second resin material containing a thermosetting resin and a conductive material, wherein the first resin material contains a thermosetting resin. And particles and/or fibers composed of magnetic metal. Further, 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, the magnetic material layer 100 and the conductive material layer 200 in the laminated body 150 satisfy Ra≦Rb. relationship. By satisfying the above relationship between the magnetic material layer 100 and the conductive material layer 200, the electromagnetic wave absorptive laminate 150 which achieves both good electromagnetic wave shielding properties and good electromagnetic wave absorptivity can be realized. Further, 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 term "magnetic metal" means a metal material that can absorb electromagnetic waves from the viewpoint of both magnetic properties and electrical conductivity.

Even if the electronic device is housed in a casing made of a conventional electromagnetic wave absorbing material, the electronic device housed in the casing may have various malfunctions due to electromagnetic wave noise such as malfunction, malfunction, or malfunction. The present inventors have made an effort to study the cause of the above, and as a result, it has been found that a small amount of electromagnetic waves transmitted through the casing (electromagnetic wave absorbing material) or a small amount of electromagnetic waves reflected from the casing after being emitted from the electronic device itself may cause various adverse conditions as described above. main reason. Further, according to the findings obtained by the present inventors, in the case of a conventional electromagnetic wave absorbing material, in many cases, electromagnetic waves of about 40% of the total amount of electromagnetic waves emitted by the electronic device are not absorbed and transmitted through the electromagnetic wave absorption. Material or reflection.

The electromagnetic wave absorbing laminated body 150 of the present embodiment can eliminate the above-mentioned irregularity of the electromagnetic wave absorbing material by using a laminated structure capable of absorbing the electromagnetic waves that are incident multiple times. Good condition. The present inventors paid attention to a case where an electromagnetic wave is an electric field and a magnetic field which alternately oscillate while propagating a wave in a space. The laminated body 150 has a laminated structure including a conductive material layer 200 and a magnetic material layer 100, and the conductive material layer 200 contains a magnetic metal that functions as a conductive material. The magnetic material layer 100 is contained as a magnetic material. Functional magnetic metal. Further, the magnetic metal functioning as a conductive material has a heating mechanism for converting a current flowing when the electric field is applied into heat energy. Further, the magnetic metal that functions as a magnetic material has a heating mechanism that converts a current flowing when the magnetic field is applied into heat energy. In other words, the laminated body 150 has 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 absorptive laminate 150 of the present embodiment has excellent electromagnetic wave absorptivity as compared with the conventional electromagnetic wave absorbing material.

Further, it is known that a conductive material layer containing a magnetic metal functioning as a conductive material generally has a higher electromagnetic wave reflectance than a magnetic material layer containing a magnetic metal functioning as a magnetic material. In this case, according to the present laminated body 150, the electromagnetic wave absorption can be performed not only by the electric field and the magnetic field, but also by the first layer and then by the other layer. Electromagnetic waves are absorbed. As a result, the electromagnetic wave absorptive laminate 150 of the present embodiment not only has excellent electromagnetic wave absorptivity, but also has excellent electromagnetic wave shielding properties as compared with the conventional electromagnetic wave absorbing material.

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

Here, in the case of using the laminated body 150, first, the above 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 can be processed into a casing sized to accommodate the electronic device 50. It can also be processed into a sheet shape to be attached to the surface of the electronic device 50.

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

In order to protect the electronic device 50 housed in the casing from the electromagnetic waves generated by the electronic device 50 disposed outside the casing, the laminated body 150 shown in FIG. 2(a) is made of the conductive material layer 200 and magnetic. The material layer 100 is disposed such that the opposite side faces the surface of the electronic device 50 housed in the casing. That is, the present laminated body 150 shown in FIG. 2(a) is disposed such that the conductive material layer 200 faces the surface of the electronic device 50. In this case, as shown in FIG. 2(b), the laminated body 150 can absorb electromagnetic waves emitted from the electronic device 50 outside the casing in at least three stages. Specifically, first, in the magnetic material layer 100, electromagnetic waves are absorbed from the viewpoint of a magnetic field (first absorption, (1) of FIG. 2(b)). Then, in the conductive material layer 200, electromagnetic waves that are not absorbed by the magnetic material layer 100 and transmitted through the magnetic material layer 100 are absorbed from the viewpoint of the electric field (second absorption, (2) of FIG. 2(b)). Then, from the viewpoint of the magnetic field, the electromagnetic wave which is reflected again on the conductive material layer 200 and is incident on the magnetic material layer 100 again (third absorption, (3) of FIG. 2(b)). Thereby, when the frequency of the electromagnetic wave is 5 GHz or more and 18 GHz or less, electromagnetic waves which are at least 99% or more of the total amount of electromagnetic waves emitted from the electronic device 50 outside the casing can be cut off. Specifically, by the configuration of the laminated body 150, it is possible to absorb electromagnetic waves of 80% or more of the total amount of electromagnetic waves emitted from the electronic device 50 outside the casing, and most of the residual electromagnetic waves that cannot be absorbed cannot be transmitted and can occur. reflection.

Moreover, in order to prevent the electronic device 50 from being broken due to electromagnetic waves emitted from the electronic device 50 itself contained in the casing, the laminated body 150 shown in FIG. 3(a) is a layer of the magnetic material layer 100 and the conductive material layer. 200 is the opposite side and the electrons contained in the housing The surface of the device 50 is configured in a relatively opposing manner. That is, the present laminated body 150 shown in FIG. 3(a) is disposed such that the magnetic material layer 100 faces the surface of the electronic device 50. In this case, as shown in FIG. 3(b), the laminated body 150 can absorb the electromagnetic waves emitted from the electronic device 50 in at least three stages. Specifically, first, in the magnetic material layer 100, electromagnetic waves are absorbed from the viewpoint of a magnetic field (first absorption, (1) of FIG. 3(b)). Then, in the conductive material layer 200, electromagnetic waves that are not absorbed by the magnetic material layer 100 and transmitted through the magnetic material layer 100 are absorbed from the viewpoint of the electric field (second absorption, (2) of FIG. 3(b)). Then, from the viewpoint of the magnetic field, the electromagnetic wave which is reflected again on the conductive material layer 200 and is incident on the magnetic material layer 100 again (third absorption, (3) of FIG. 3(b)). Therefore, when the frequency of the electromagnetic wave is 5 GHz or more and 18 GHz or less, electromagnetic waves having a minimum of 99% or more of the total amount of electromagnetic waves emitted from the electronic device 50 housed in the casing can be cut off. Specifically, with the configuration of the laminated body 150, it is possible to absorb electromagnetic waves of 80% or more of the total amount of electromagnetic waves emitted from the electronic device 50, and most of the residual electromagnetic waves that cannot be absorbed cannot be transmitted and can be reflected.

Based on the above, the laminated body 150 preferably has a laminated structure in which at least three or more layers of the conductive material layer 200, the magnetic material layer 100, and the conductive material layer 200 are sequentially laminated. Thereby, the electromagnetic wave emitted by the electronic device 50 disposed outside the casing or the electromagnetic wave emitted by the electronic device 50 itself housed in the casing can be prevented from occurring at the same time, and the electronic device 50 housed in the casing can be prevented from occurring. malfunction.

Here, specific examples of the electronic device 50 of the present invention include a mobile phone, a personal computer, a television, a casing having a wireless LAN function (about 5 GHz), and an in-vehicle sensor. Further, according to the laminated body 150, regardless of the type of the electronic device 50, it is possible to achieve both good electromagnetic wave shielding and electromagnetic wave absorption as long as the electromagnetic wave frequency is 5 GHz or more and 18 GHz or less. Retractable.

Next, the configuration of the electromagnetic wave absorptive laminate 150 of the present embodiment which is assumed to be used by any of the above methods will be described. Here, it is preferable that the conductive material layer 200 and the magnetic material layer 100 constituting the laminated body 150 are layers obtained by molding a paper-making body composed of a resin material forming each layer. Further, in the present laminate 150, only one of the conductive material layer 200 and the magnetic material layer 100 may be a layer obtained by molding a paper-making body.

Here, the paper-making body is generally used as a technical term indicating "the state of the object obtained by the method of making a fiber material." This state is described in, for example, Japanese Patent No. 4675276 and Japanese Patent No. 5426399. According to the description of the above-mentioned documents, the papermaking system refers to a solid component in a wet state in which a liquid component is removed from a raw material slurry obtained by dispersing a raw material such as a fiber or a resin in a dispersion medium and remaining on a filter. The above-mentioned wet state as used herein means a hardened state before the drying and heat treatment, that is, a hardened state before the post-hardening treatment. Further, according to these documents, the paper-making body is used for a molded body obtained by heating and drying and molding in a molding die. That is, it is described that a papermaking body is used as a molding material.

Hereinafter, the laminated body 150 will be described in detail as an example in which both the conductive material layer 200 and the magnetic material layer 100 are layers obtained by molding a paper-making body. In other words, the laminated body 150 described below has a laminated structure composed of a molded product obtained by molding the formed body by a method such as heat press pressing. Further, the paper-making body may be in the form of a sheet, or may be in the form of a green body processed into a shape that mimics the shape of a desired molded article.

First, the above-mentioned papermaking body will be described with reference to Fig. 4 .

Fig. 4 is an enlarged view showing a region indicated by a broken line in the papermaking body. The papermaking body 10 of the present embodiment contains a binder resin A and a fiber material (filler) B. Moreover, the electromagnetic of the papermaking body 10 is improved. From the viewpoint of the wave shielding property, the fiber material B is preferably aligned in the plane direction of the papermaking body 10 as shown in FIG. In other words, the fibrous material (filler) B is preferably randomly aligned when viewed in the in-plane direction of the papermaking body 10, and is aligned in the plane direction of the papermaking body 10 when viewed from the thickness direction of the papermaking body 10. In the present specification, the fiber material B is aligned in the plane direction of the papermaking body 10, that is, as long as most of the fiber material B is aligned in the plane direction of the papermaking body 10, a part of the fiber material B may not be formed along the papermaking. The plane direction of the body 10 is aligned. For example, 90% or more of the fiber material B may be aligned in the plane direction of the papermaking body 10. In addition, in the present specification, the "fibrous material" includes a non-spherical material such as a flat shape or a needle shape in addition to a fibrous material. In the case where a flat material (flat filler) is used as the fiber material B, the flat filler is aligned such that its thick wall direction is substantially parallel to the planar direction of the sheet body 10.

Further, the binder resin A contained in the papermaking body 10 functions as a bonding material that bonds the fiber materials (filler) B to each other, and serves as a molded body for the formed body 10 by the subsequent heat treatment. It functions as a molding material. The binder resin A in the papermaking body 10 is in an incompletely hardened state, for example, a B-stage state. By heating the papermaking body 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 producing a molded body.

The papermaking body 10 of the present embodiment is obtained by the following papermaking method, and has the following structural features A to C.

(Feature A) When the surface of the paper-making body 10 was observed in a plan view (in the in-plane direction of the papermaking body 10), it was found that the fiber materials were randomly aligned.

(Feature B) When the cross-section is observed in the thickness direction of the paper-making body 10, the fiber material can be seen. The alignment state is highly controlled and the fiber material is aligned in a particular direction. In other words, the fibrous material is in a laminated state in the thickness direction of the papermaking body 10.

(Feature C) The fiber materials are bonded to each other by a binder resin.

Since the papermaking body 10 of the present embodiment is formed by the papermaking method, it is presumed that the fibrous material (filler) B can be uniformly dispersed in the papermaking body 10, or the fibrous material (filler) B can be formed to be appropriately entangled with each other. Though it is not necessarily clear, it is considered that the electromagnetic wave absorbing laminated body 150 formed using the papermaking body 10 can achieve both electromagnetic wave shielding properties and electromagnetic wave absorbing properties at a high level. Moreover, since the workability of the papermaking method is excellent, the designability of the papermaking body 10 can be improved. Further, the papermaking method has few restrictions on the combination of the constituent materials of the papermaking body 10. Therefore, various other additives can be suitably used together with the binder resin A and the fiber material (filler) B in accordance with the characteristics required for the electromagnetic wave absorbing laminate.

The papermaking body 10 may have, for example, a flat shape.

As described above, the fibrous material (filler) B is aligned in the direction of the plane of the papermaking body 10 in the papermaking body 10. Thereby, in particular, the electromagnetic wave shielding property of the paper-making body 10 in the thickness direction thereof can be improved. In the enlarged cross-sectional view of the thickness of the blank 10 shown in Fig. 4, the fiber material (filler) B (B in Fig. 4) is exemplified along the plane direction of the papermaking body 10 and the adhesive resin A (Fig. 4 A) is between the fibrous material (filler) B. In this case, the fibrous materials (fillers) B are bonded to each other, for example, by the binder resin A. The mesh structure of the fiber material B is formed by the fiber material B being aligned in the planar direction of the papermaking body 10, so that the connection of the conductive paths can be easily realized. 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 aligned 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 can be surely formed, and the papermaking can be improved. Body 10 Magnetic wave shielding. In other words, the content of the fiber material B can be reduced by using the papermaking body 10, and the conductive material layer or the magnetic material having high electromagnetic wave shielding property can be formed as compared with the case where the conductive material layer or the like is formed by a method other than the papermaking method. Floor.

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

Further, in the papermaking body 10, the angle between the longitudinal direction of the fibrous material (filler) B and the surface direction of the papermaking body 10 is preferably about 0 to 10°, more preferably about 0 to 8°. The fiber material (filler) B is aligned so as to satisfy the condition, and the fiber material (filler) B is in a state of more uniform lamination in the thickness direction of the papermaking body 10. The present laminated body 150 formed by using the papermaking body 10 can achieve both electromagnetic wave shielding properties and electromagnetic wave absorptivity at a higher level.

In the case where the conductive material layer 200 and the magnetic material layer 100 of the present laminated body 150 are formed by forming the formed body 10 having the above structural features, the fibrous material (filler) B (conductive material) in each layer Or magnetic material) is controlled in the thickness direction toward a specific direction. Therefore, compared with the case where the conductive material layer and the magnetic material layer are formed by the molded body other than the papermaking body 10, the present laminated body 150 which is remarkably excellent in electromagnetic wave absorptivity and electromagnetic wave shielding property can be obtained.

Further, although the present laminated body 150 shown in Fig. 1 is formed by bonding the magnetic material layer 100 and the conductive material layer 200, an intermediate layer may be provided between the respective layers. Further, in the case where the magnetic material layer 100 and the conductive material layer 200 are bonded to each other in the present laminated body 150, as shown in FIG. 5, in the joint interface region of the magnetic material layer 100 and the conductive material layer 200, a magnetic material is formed. Floor An intermediate layer in which a resin material of 100 is mixed with a resin material forming the conductive material layer 200. Specifically, it is preferable that the joint interface of the magnetic material layer 100 and the conductive material layer 200 form a zigzag structure. Thereby, the joint interface region of the magnetic material layer 100 and the conductive material layer 200 can be formed in a gradual appearance. Thereby, the difference in the characteristic impedance between the resin materials forming the respective layers can be reduced, so that the amount of electromagnetic wave reflection at the joint interface between the magnetic material layer 100 and the conductive material layer 200 in the laminated body 150 can be reduced. Thereby, the amount of electromagnetic waves transmitted through the magnetic material layer 100 reaching the conductive material layer 200 without being absorbed by the magnetic material layer 100 is increased, and the amount of electromagnetic waves absorbed in the conductive material layer 200 from the viewpoint of the electric field is increased. Therefore, as a result, the electromagnetic wave absorption amount of the laminated body 150 itself is increased, so that the electromagnetic wave shielding ability of the laminated body 150 can be further improved. Further, in order to form a zigzag structure, it is preferable to form the magnetic material layer 100 and the conductive material layer 200 by a papermaking body obtained by the following papermaking method. More specifically, first, the formed body formed of each of the constituent materials of the magnetic material layer 100 and the conductive material layer 200 is subjected to surface processing so as to obtain a desired zigzag structure. Next, the paper-making bodies were laminated to each other so that the surface-side contact of the surface processing was performed. Thereafter, the laminated body is formed by press molding or the like to obtain an electromagnetic wave absorbing laminated body. Such a zigzag structure can be easily formed by re-forming and combining the paper-making bodies with each other (for example, press-forming), and it is not obtained if it is a laminated body of a general film or a laminated body obtained by drying after coating. Moreover, if it is an injection molding method or an extrusion molding method, it is difficult to laminate, and it is not suitable for forming a zigzag structure.

Next, a method of manufacturing the papermaking body 10 will be described.

6(a) to 6(c) are cross-sectional views schematically showing an example of a method of manufacturing the papermaking body 10 of the present embodiment.

The papermaking body 10 is produced, for example, by a wet papermaking method. The manufacturer of the papermaking body 10 of the present embodiment The method includes, for example, a step of preparing a material composition containing the binder resin A and the fiber material (filler) B by a papermaking method. Therefore, the case of forming a material composition containing the thermosetting resin A and the filler B will be described below by way of example.

First, as shown in FIG. 6(a), the adjusted material composition is added to a solvent and stirred to be dispersed. Here, the material composition containing the thermosetting resin A, the filler B, and other additives as needed is added to the solvent and stirred to disperse. Thereby, a varnish-like material composition for forming the papermaking body 10 can be obtained. As a method of dispersing each component in a solvent, the method of stirring by a disperser is mentioned, for example. In addition, in FIG. 6, the symbol A represents a thermosetting resin, and the symbol B represents a filler.

The solvent is preferably such that it is less volatile during the dispersion of the constituent material of the material composition, is easy to remove the solvent, inhibits the residue in the papermaking body 10, and suppresses an increase in energy due to solvent removal. It is a solvent having a boiling point of 50 ° C or more and 200 ° C or less. Specific examples of such a solvent include water; or an alcohol such as ethanol, 1-propanol, 1-butanol or ethylene glycol; or acetone, methyl ethyl ketone, 2-heptanone or cyclohexanone. Ketones; or ethyl acetate, butyl acetate, methyl acetate, methyl acetate, etc.; or tetrahydrofuran, isopropyl ether, two An ether such as an alkane or a furfural. These solvents may be used alone or in combination of two or more. Among them, water is preferably used because of its abundant supply, low price, low environmental load, high safety, and ease of handling.

In the above-described step of obtaining a varnish-like material composition, as the thermosetting resin A, for example, a thermosetting resin in a solid state having an average particle diameter of 500 μm or less can be used. Thereby, in the step of coagulating the material composition containing the thermosetting resin, the state of condensation of the material composition can be more easily formed. In the above steps of obtaining a varnish-like material composition, The average particle diameter 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 diameter can be obtained, for example, by a pulverization treatment using an atomizer or the like. In addition, the average particle diameter of the thermosetting resin A can be, for example, a laser diffraction type particle size distribution measuring apparatus such as SALD-7000 manufactured by Shimadzu Corporation, and a 50% particle diameter based on mass can be obtained as an average particle diameter.

In the present embodiment, it is preferred to add a coagulant to the varnish-like material composition obtained above. Thereby, the thermosetting resin A and the filler B in the solvent can be more easily condensed into a floc shape to obtain the coagulum F.

Next, as shown in Fig. 6 (b), the solvent and the condensate F obtained above were placed in a container having a bottom surface composed of a 30-mesh sieve, and the solvent was discharged from a 30-mesh sieve. Thereby, the condensate F and the solvent can be separated from each other. At this time, on the 30-mesh sieve, the condensate F was left in a sheet shape. In the present embodiment, the shape of the obtained formed body 10 can be adjusted by appropriately selecting the shape of the 30-mesh screen.

In the present embodiment, the sheet-like condensate F obtained above can be taken out, placed in a drying oven, and dried to further remove the solvent. The papermaking body 10 shown in Fig. 6(c) was produced in this manner.

Thereafter, the desired layer can be obtained by molding the obtained papermaking body 10. Here, examples of the method of molding the magnetic material layer 100 or the conductive material layer 200 of the present embodiment include press molding and the like. Specifically, first, the paper-making body 10 is pressed by a press plate, and a heating plate is placed on the outer peripheral side of the press plate to perform heating. Thereby, a molded body constituting the magnetic material layer 100 or the conductive material layer 200 can be obtained. In the case where the paper-making body 10 contains a thermosetting resin as the binder resin A, for example, the thermosetting resin in the molded body can be obtained. The above forming step is carried out in a semi-hardened state. Thereby, the molded body can be thermally cured after laminating the molded body to another member, so that the molded body and the other members can be more strongly adhered 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 Magnetic Material Layer 100>

As described above, the resin material (first resin material) forming the magnetic material layer 100 contains a thermosetting resin and particles and/or fibers composed of a magnetic metal. Here, in the case where the magnetic material layer 100 is a layer obtained by molding a paper-making body, the thermosetting resin functions as the binder resin A shown in FIG. 4 . Further, the particles and/or fibers composed of the above-described magnetic metal function as the filler B shown in Fig. 4 .

(Binder Resin A)

As the name implies, the binder resin A functions as a binder for bonding the filler B in the papermaking body. Therefore, the binder resin A may be any resin that can bond the filler B. From the viewpoint of stably producing the paper-making body 10 as the binder resin A, that is, the thermosetting resin, for example, a resin which is solid at a normal temperature (25 ° C) in a non-heated state is preferably used.

Specific examples of the thermosetting resin include a phenol resin, an epoxy resin, an unsaturated polyester resin, a melamine resin, and a polyurethane. These may be used alone or in combination of two or more. Among them, at least one of a phenol resin and an epoxy resin is preferably included from the viewpoint of formability.

The paper-making body (hereinafter also referred to as a paper-making body X) for forming the magnetic material layer 100 in the present embodiment may contain, for example, a thermosetting resin having a granular or powdery shape. With this, The mechanical properties of the cured product obtained by hardening the paper-making body X can be more effectively improved. The reason for this is not clear, but it is presumed that the shape of the thermosetting resin has a granular or powdery shape, and the impregnation property at the time of melting is improved, and the filler is formed satisfactorily. The interface between B and a thermosetting resin. In the present embodiment, for example, by producing a paper-making body X by thermosetting a thermosetting resin as a powder or a filler and a filler B, a paper-making body containing a thermosetting resin having a granular or powdery shape can be realized. X.

The thermosetting resin having a granular or powdery shape may include, for example, a resin having an average particle diameter of 500 μm or less. The average particle diameter of the thermosetting resin having a granular or powdery shape is more preferably 1 nm or more and 300 μm or less from the viewpoint of more effectively improving the mechanical properties of the cured product obtained by hardening the paper-making body X. The thermosetting resin having such an average particle diameter can be obtained, for example, by pulverizing treatment using an atomizing pulverizer or the like. In addition, the average particle diameter of the thermosetting resin can be, for example, a laser diffraction type particle size distribution measuring apparatus such as SALD-7000 manufactured by Shimadzu Corporation, and a 50% particle diameter based on mass is obtained as an average particle diameter.

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 based on the total mass of the preform X. Thereby, the workability or lightness of the papermaking body X can be more effectively improved. 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 based on the total mass of the preform X. Thereby, the thermal characteristics of the cured product obtained by hardening the paper-making body X can be more effectively improved.

(Fiber material (filler) B)

The papermaking body X of the present embodiment contains particles or fibers composed of a magnetic metal as the filler B. Here, the fiber made of a magnetic metal may be a metal fiber composed of a single metal element, or may be an alloy fiber composed of a plurality of metals. The metal fiber preferably contains, for example, selected from One or more metal elements of the group consisting of aluminum, silver, copper, magnesium, iron, chromium, nickel, titanium, zinc, tin, molybdenum, and tungsten. In addition, as the fiber made of a magnetic metal in the present embodiment, for example, a stainless steel fiber manufactured by Nippon Precision Co., Ltd. or Bekaert Japan Co., Ltd., or a copper fiber manufactured by Rainbow Technology Co., Ltd., which is commercially available, can be purchased. , aluminum fiber, brass fiber, steel fiber, titanium fiber, phosphor bronze fiber, etc., but are not limited thereto. These fibers made of a magnetic metal may be used alone or in combination of two or more.

Further, as the fiber made of a magnetic metal, a fiber which has been surface-treated with a decane coupling agent, an aluminate coupling agent, a titanate coupling agent or the like according to a desired property, or in order to improve adhesion to a resin or A fiber that has been treated with a sizing agent.

The fiber length of the fiber made of a 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 a magnetic metal is, for example, preferably 0.5 μm or more and 1 mm or less, more preferably 3 μm or more and 100 μm or less. When the fiber length and the fiber width of the fiber made of the magnetic metal are within the above range, it is easier to make the aspect ratio of the fiber made of the magnetic metal within a desired range. Therefore, the strength of the laminated body 150 obtained by molding the formed body X can be more effectively improved. Moreover, it can also contribute to the improvement of the uniform dispersibility of the filler B in the papermaking body X.

The content of the fiber 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 based on the entire body of the papermaking body X. Thereby, various characteristics of the mechanical properties, thermal characteristics, and electromagnetic wave shielding properties of the molded body obtained by molding the paper-making body X can be more effectively improved. On the other hand, the content of the fiber composed of the magnetic metal is preferably 80% by weight or less, more preferably 70% by weight or less, and particularly preferably 65% by weight or less based on the entire mass of the preform X. Thereby, the workability or lightness of the papermaking body X can be improved. Moreover, the dispersibility of the fiber made of the magnetic metal can be more effectively improved, and the mechanical properties, thermal characteristics, and electromagnetic wave shielding properties of the molded body obtained by molding the preform X can be improved.

The particles made of the magnetic metal may be any particles formed of a metal capable of being magnetic. Specific examples of the metal include metals such as Fe, Ni, and Co; and further examples thereof include Fe-Co alloy, Fe-Cr alloy, Fe-Ni alloy, Ni-Co alloy, Fe-Cr-Si alloy, and Fe-Ni. - alloys such as Mo alloy, Fe-Si alloy, and Fe-Si-Al alloy. Further, an alloy obtained by adding one or more of the subcomponents of Al, Co, Cr, Cu, Mn, Mo, Nb, Ti, and Zn to the above-mentioned metal and alloy may be mentioned. Among them, alloy particles containing iron and aluminum are preferred.

When the content of the subcomponents such as Al, Co, Cr, Cu, Mn, Mo, Nb, Ti, and Zn contained in the particles made of the magnetic metal is excessive, the influence of the magnetic flux density is lowered. Therefore, the total amount of the subcomponents is preferably 10% by mass or less, and particularly preferably 5% by mass or less. Further, there may be other sub-components, that is, trace components other than the above-mentioned elements (for example, O, C, P, Mn, etc.), which may be mixed in the raw material of the alloy or in the manufacturing process of the alloy, but as long as it is not damaged. The object of the invention is to allow its existence. These trace components are preferably 1% by mass or less in total. Further, examples of the shape of the particles made of a magnetic metal include a flat shape, a granular shape, a plate shape, and a needle shape.

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 based on the entire volume of the papermaking body X. Thereby, various characteristics of the mechanical properties, thermal characteristics, and electromagnetic wave shielding properties of the molded body obtained by molding the paper-making body X can be more effectively improved. 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 particularly preferably 65% by weight or less based on the entire mass of the preform X. Thereby, the workability or lightness of the papermaking body X can be improved. Moreover, the dispersibility of the particles made of the magnetic metal can be more effectively improved, and the mechanical properties, thermal characteristics, and electromagnetic wave shielding properties of the molded body obtained by molding the formed body X can be improved.

The filler B may contain the following fibrous fillers or other fillers having an aspect ratio lower than that of the fibrous filler depending on the desired properties. Further, the fibrous filler or the other filler having an aspect ratio lower than that of the fibrous filler may be surface-treated with a decane coupling agent, an aluminate coupling agent, a titanate coupling agent, or the like, or may be improved in adhesion to the resin. Alternatively, it is handled by a sizing agent.

The fibrous filler may include, for example, inorganic fibers selected from the group consisting of carbon fibers, glass fibers, and ceramic fibers; natural fibers such as wood fibers, cotton yarns, hemp, and wool; regenerated fibers such as rayon fibers; semi-synthetic fibers such as cellulose fibers; and polydecylamine. Fiber, polyarsenamide fiber, polyimide fiber, polyvinyl alcohol fiber, polyester fiber, acrylic fiber, polyparaphenylene benzoate One or more of synthetic fibers such as azole fibers, polyethylene fibers, polypropylene fibers, polyacrylonitrile fibers, and ethylene-vinyl alcohol fibers. Among them, from the viewpoint of improving thermal conductivity, it is preferred to contain inorganic fibers, and more preferably carbon fibers. Moreover, it is more preferable to contain one or more types of synthetic fibers and inorganic fibers from the viewpoint of improving mechanical properties. Further, in terms of improving the bending strength, it is particularly preferable to contain carbon fibers. Further, in view of improving impact resistance, it is particularly preferable to contain a polyarylene fiber.

Further, the aspect ratio of the fibrous filler is preferably 100 or more, more preferably 150 or more, and still more preferably 200 or more. On the other hand, the aspect ratio of the fibrous filler is preferably 1000 or less, and more preferably 700 or less, from the viewpoint of improving the ease of manufacture of the formed body X or the strength of the cured product obtained by molding the formed body X. Furthermore, the aspect ratio of fibrous fillers is determined by fiber length/fiber Find the width. Further, the fibrous filler described in the present specification does not include the following pulp C in its concept.

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. Further, the fiber width of the fibrous filler is, for example, preferably 0.5 μm or more and 1 mm or less, more preferably 3 μm or more and 100 μm or less. By setting the fiber length and the fiber width of the fibrous filler to the above range, it is easier to make the aspect ratio of the fibrous filler within a desired range.

The above filler having an aspect ratio lower than that of the fibrous filler is, for example, a filler having an aspect ratio of 50 or less. By including such another filler, other fillers can be wound around the fibrous filler, and as a result, the mechanical strength of the obtained molded article can be improved. Further, the aspect ratio is preferably 50 or less, more preferably 30 or less, and particularly preferably 20 or less.

The fiber length or the long diameter of the other 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 still more preferably 10 μm or more and 500 μm or less. Further, the fiber width or the short diameter of the other filler is preferably 0.5 μm or more and 500 μm or less, and more preferably 1 μm or more and 100 μm or less. Thereby, it is easier to make the aspect ratio within the desired range. It is also possible to improve the balance between the thermal properties, the mechanical properties, and the electromagnetic wave shielding ability of the molded body obtained in this manner.

The above other fillers may have various shapes depending on the desired characteristics. In the present embodiment, as the other filler, for example, at least one of a fiber material such as milled fiber or a powder or granule can be used.

Here, in the case where the other fillers described above comprise a fibrous material, the other filler may, for example, comprise a component selected from the group consisting of aluminum, silver, copper, magnesium, iron, chromium, nickel, titanium, zinc, tin, molybdenum and tungsten. Metal fibers of one or more metal elements in the group; inorganic fibers such as carbon fibers, glass fibers, ceramic fibers; natural fibers such as wood fibers, cotton yarn, hemp, wool; regenerated fibers such as rayon fibers; cellulose fibers, etc. Semi-synthetic fiber; polyamide fiber, polyamine fiber, polyimine fiber, polyvinyl alcohol fiber, polyester fiber, acrylic fiber, poly-p-phenylene benzoate One or more of synthetic fibers such as azole fibers, polyethylene fibers, polypropylene fibers, polyacrylonitrile fibers, and ethylene-vinyl alcohol fibers. Among these, it is preferable to contain one or two or more kinds of metal fibers and inorganic fibers from the viewpoint of improving thermal conductivity, and more preferably at least one of metal fibers and carbon fibers. It is particularly preferable to contain at least carbon fibers from the viewpoint of improving the balance between mechanical properties and thermal conductivity.

In the case where the other fillers described above comprise a fibrous material, the other filler may, for example, comprise a carbon material selected from the group consisting of graphite, carbon black, carbon, coke, diamond, carbon nanotubes, graphene, fullerene, talc, calcined clay, Uncalcined clay, mica, glassy silicates; oxides such as titanium oxide and aluminum oxide; antimony compounds such as magnesium niobate, molten vermiculite, crystalline vermiculite; calcium carbonate, magnesium carbonate, water a carbonate such as talc; an oxide such as zinc oxide or magnesium oxide; a hydroxide such as aluminum hydroxide, magnesium hydroxide or calcium hydroxide; a sulfate such as barium sulfate, calcium sulfate or calcium sulfite. Or a sulfite; a borate such as zinc borate, barium metaborate, aluminum borate, calcium borate or sodium borate; or one or more of a nitride such as aluminum nitride, boron nitride or tantalum nitride Powder granules. Among them, from the viewpoint of improving the balance between mechanical properties and thermal conductivity, it is preferable to contain a carbon material, and more preferably at least one of graphite or carbon black.

(Pulp C)

The papermaking body X may contain, for example, pulp C. Pulp C is a fibrous material having a fibril structure, and can be obtained, for example, by fibrillating a fibrous material by mechanical or chemical methods. In the method for producing a paper-making body using the above-mentioned papermaking method, the paper pulp C can be copied together with the thermosetting resin and the filler B. The thermosetting resin is more effectively coagulated. Thereby, a more stable copying body X can be produced.

Examples of the pulp C include cellulose fibers such as cotton pulp and wood pulp, natural fibers such as kenaf, jute, and bamboo, and para-type wholly aromatic polyamide fibers (polyarsenamide fibers) or copolymerization thereof. Fibrils of organic fibers such as aromatic polyester fibers, polybenzoxazole fibers, meta-type polyamine fibers or copolymers thereof, acrylic fibers, acrylonitrile fibers, polyimine fibers, and polyamide fibers Compound. The pulp C may contain one or two or more of them. Among them, from the viewpoint of improving the mechanical properties or electromagnetic wave shielding properties of the molded article using the formed body X or improving the dispersibility of the filler B, it is particularly preferable to contain a polyarylene composed of polyarylene fiber. Any one or both of an amine pulp and a polyacrylonitrile pulp composed of acrylonitrile fibers.

The content of the pulp C is preferably 0.5% by weight or more, more preferably 1.5% by weight or more, and still more preferably 2% by weight or more based on the total mass of the papermaking body X. Thereby, the thermosetting resin can be more effectively coagulated at the time of papermaking, and further, the production of the stable papermaking body X can be achieved. Further, the content of the pulp C is preferably 15% by weight or less, more preferably 10% by weight or less, even more preferably 8% by weight or less based on the total mass of the preform X. Thereby, the mechanical properties or thermal properties of the cured product obtained by hardening the paper-making body X can be more effectively improved.

(Coagulant D)

The papermaking body X may contain, for example, a coagulating agent D. The coagulant D has a function of coagulating the thermosetting resin or the fiber material into a floc in the production method using the papermaking body X of the above-mentioned papermaking method. Therefore, the manufacture of a more stable resin sheet can be achieved.

The coagulant D may include, for example, one or more selected from the group consisting of a cationic polymer coagulant, an anionic polymer coagulant, a nonionic polymer coagulant, and an amphoteric polymer coagulant. Examples of such a coagulant D include cationic polyacrylamide and an anion. Polyacrylamide, Huffman polyacrylamide, Mannich polyacrylamide, amphoteric copolymerized polyacrylamide, cationized starch, amphoteric starch, polyethylene oxide, and the like. Further, in the coagulant D, the polymer structure, the molecular weight, the amount of the functional group such as a hydroxyl group or an ionic group, and the like can be adjusted without particular limitation depending on the desired properties.

The total amount of the coagulant D to the constituent material of the papermaking body X is preferably 0.05% by weight or more, more preferably 0.1% by weight or more, and still more preferably 0.15% by weight or more. Thereby, in the manufacture of the papermaking body X using the papermaking method, the productivity can be improved. On the other hand, the total amount of the coagulant D to the constituent material of the papermaking body X is preferably 3% by weight or less, more preferably 2% by weight or less, and still more preferably 1.5% by weight or less. As a result, in the production of the papermaking body X using the papermaking method, the dehydration treatment and the like can be performed more easily and stably.

The papermaking body X may contain, for example, a powdery substance having ion exchange ability other than the above components. As the powdery substance having ion exchange ability, for example, one or two or more kinds of interlayer compounds selected from the group consisting of clay minerals, flaky fine-grain fine particles, hydrotalcites, fluorine-bearing mica, and swellable synthetic mica are preferably used. Examples of the clay mineral include bentonite, halloysite, sapite, shale, zirconium phosphate, and titanium phosphate. Examples of the hydrotalcites include hydrotalcites and hydrotalcite-like substances. Examples of the fluorine band mica include lithium type fluorine band mica and sodium type fluorine band mica. Examples of the swellable synthetic mica include sodium type fluorotetralin mica and lithium type fluorotetralin mica. The interlayer compounds may be natural or synthetic compounds. Among them, it is more preferable that the clay mineral has a wide range of choices in terms of both a natural product and a synthetic material, and further preferably a bentonite. Examples of the bentonite include montmorillonite, aluminum bentonite, nontronite, saponite, lithium bentonite, zinc bentonite, and strontite. Any one or more of them may be used. Montmorillonite is an aqueous silicate of aluminum, but It may be a bentonite containing montmorillonite as a main component and additionally containing minerals such as quartz or mica, feldspar, and zeolite. When used for the purpose of minding coloring or impurities, it is preferably a synthetic bentonite (Sumecton) having less impurities.

Further, the papermaking body X may be based on the adjustment of the production conditions or the purpose of the desired physical properties, for example, containing a stabilizer selected from the group consisting of an antioxidant or a UV absorber for improving the properties, a mold release agent, a plasticizer, and a flame retardant. , resin hardening catalyst or hardening accelerator, pigment, dry paper strength enhancer, wet paper strength enhancer and other paper strength enhancer, yield improver, water filter improver, size fixative, defoamer, acid paper Sizing with rosin-based sizing agent, rosin-based sizing agent for neutral paper, alkyl ketene dimer sizing agent, alkenyl succinic anhydride sizing agent, special modified rosin sizing agent, etc. One or more of additives such as a coagulant such as a reagent, aluminum sulfate, aluminum chloride or polyaluminum chloride.

<Material for Forming Conductive Material Layer 200>

As described above, the resin material (second resin material) forming the conductive material layer 200 contains a thermosetting resin and a conductive material. Here, when the conductive material layer 200 is a layer obtained by molding a paper-making body, the thermosetting resin functions as the binder resin A shown in FIG. 4 . Then, when the conductive material layer 200 is a layer formed by molding a paper-making body, the conductive material functions as the filler B shown in FIG. 4 .

Further, in addition to the filler B, the resin material forming the conductive material layer 200 may be the same material as the material forming the magnetic material layer 100. Further, in the following description, the paper-making body for forming the conductive material layer 200 is referred to as a paper-making body Y.

(filler B)

The material Y of the present embodiment may contain a conductive material as the filler B. As the conductive The material may, for example, be a fiber or a particle formed of a material which can be electrically conductive. Examples of the fiber include metal fibers, carbon fibers, and the like. Further, specific examples of the metal material constituting the metal fiber include copper, stainless steel, aluminum, nickel, titanium, tungsten, tin, lead, iron, silver, chromium, carbon, or the like. Among them, alloy particles containing iron and aluminum are preferred. Further, when the conductive material is a particle, the shape thereof may be a flat shape, a granular shape, a plate shape, a needle shape or the like.

Further, the conductive material of the present embodiment is preferably processed into a flat shape from the viewpoint of the conductive effect by the network structure of the filler B formed in the paper-making body Y and the electromagnetic wave absorbing effect by magnetic properties. Magnetic particles (flat magnetic particles). As described above, the flat magnetic particles in the paper-making body Y are aligned so that the thickness direction thereof is substantially parallel to the plane direction of the paper-making body Y, and the electrical conductivity of the paper-making body Y is improved. As a result, the electromagnetic wave shielding property of the conductive material layer 200 using the blank Y can be further improved. Further, the above effects are obtained by containing flat magnetic particles as the filler B of the preform Y. In the method other than the papermaking method, it is difficult to uniformly disperse the flat magnetic particles in the molded body, and therefore it is preferable to use the filler B of another shape (for example, a 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 based on the entire body of the papermaking body Y. Thereby, various characteristics of the mechanical properties, thermal characteristics, and electromagnetic wave shielding properties of the molded body obtained by molding the paper-making body Y can be more effectively improved. 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 based on the entire mass of the preform. Thereby, the workability or lightness of the paper-making body Y can be improved. Moreover, the dispersibility of the conductive material can be more effectively improved, and the mechanical properties, thermal characteristics, and electromagnetic wave shielding properties of the molded body obtained by molding the preform Y can be improved.

The filler B may use the following fibrous filler or other filler having an aspect ratio lower than that of the fibrous filler depending on the desired properties. Further, the fibrous filler or the other filler having an aspect ratio lower than that of the fibrous filler may be surface-treated with a decane coupling agent, an aluminate coupling agent, a titanate coupling agent, or the like, or may be improved in adhesion to the resin. Alternatively, it is handled by a sizing agent.

The fibrous filler may include, for example, inorganic fibers selected from the group consisting of carbon fibers, glass fibers, and ceramic fibers; natural fibers such as wood fibers, cotton yarns, hemp, and wool; regenerated fibers such as rayon fibers; semi-synthetic fibers such as cellulose fibers; and polydecylamine. Fiber, polyarsenamide fiber, polyimide fiber, polyvinyl alcohol fiber, polyester fiber, acrylic fiber, polyparaphenylene benzoate One or more of synthetic fibers such as azole fibers, polyethylene fibers, polypropylene fibers, polyacrylonitrile fibers, and ethylene-vinyl alcohol fibers. Among them, from the viewpoint of improving thermal conductivity, it is preferred to contain inorganic fibers, and more preferably carbon fibers. In addition, it is more preferable to contain one or more types of synthetic fibers and inorganic fibers from the viewpoint of improving mechanical properties. In particular, carbon fiber is particularly preferable from the viewpoint of improving the bending strength. Further, in view of improving impact resistance, it is particularly preferable to contain a polyarylene fiber.

Further, the aspect ratio of the fibrous filler is preferably 100 or more, more preferably 150 or more, and still more preferably 200 or more. On the other hand, from the viewpoint of improving the ease of manufacture of the paper-making body Y or the strength of the cured product obtained by molding the paper-making body Y, the aspect ratio of the fibrous filler is preferably 1,000 or less, more preferably 700 or less. Further, the aspect ratio of the fibrous filler was determined from the fiber length/fiber width. Further, the fibrous filler in the present specification does not include pulp C in its concept.

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. the following. Further, the fiber width of the fibrous filler is, for example, preferably 0.5 μm or more and 1 mm or less, more preferably 3 μm or more and 100 μm or less. By setting the fiber length and the fiber width of the fibrous filler to the above range, it is easier to make the aspect ratio of the fibrous filler within a desired range.

Regarding the above other filler having an aspect ratio lower than that of the fibrous filler, for example, the aspect ratio is 50 or less. Thereby, the fibrous filler can be wound around the above, and the mechanical strength of the obtained molded article can be improved. Further, the aspect ratio is preferably 50 or less, more preferably 30 or less, and particularly preferably 20 or less.

The fiber length or the long diameter of the other filler having an aspect ratio lower than that of the fibrous 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 still more preferably 10 μm or more and 500 μm or less. Further, the fiber width or the short diameter of the other filler is preferably 0.5 μm or more and 500 μm or less, and more preferably 1 μm or more and 100 μm or less. Thereby, it is easier to make the aspect ratio within the desired range. It is also possible to improve the balance between the thermal properties, the mechanical properties, and the electromagnetic wave shielding ability of the molded body obtained in this manner.

The other fillers having an aspect ratio lower than that of the fibrous filler may have various shapes depending on the desired characteristics. In the present embodiment, as the other filler, for example, at least one of a fiber material such as a milled fiber or a powder or granule can be used.

Here, in the case where the above-mentioned other filler having an aspect ratio lower than the fibrous filler contains the fibrous material, the other filler may include, for example, selected from the group consisting of aluminum, silver, copper, magnesium, iron, chromium, nickel, titanium, zinc. Metal fiber of one or more metal elements of tin, molybdenum and tungsten; inorganic fibers such as carbon fiber, glass fiber and ceramic fiber; natural fiber such as wood fiber, cotton yarn, hemp, wool; Regenerated fibers; semi-synthetic fibers such as cellulose fibers; polyamidamine fibers, polyarylene fibers, polyimine fibers, polyvinyl alcohol fibers, polyester fibers, acrylic fibers, polyparaphenylene benzophenone One or more of synthetic fibers such as azole fibers, polyethylene fibers, polypropylene fibers, polyacrylonitrile fibers, and ethylene-vinyl alcohol fibers. Among these, it is preferable to contain one or two or more kinds of metal fibers and inorganic fibers from the viewpoint of improving thermal conductivity, and more preferably at least one of metal fibers and carbon fibers. It is particularly preferable to contain at least carbon fibers from the viewpoint of improving the balance between mechanical properties and thermal conductivity.

In the case where the above-mentioned aspect ratio is lower than the other filler of the fibrous filler, the other filler may include, for example, graphite, carbon black, carbon, coke, diamond, carbon nanotube, graphene, fullerene, and the like. Carbon materials; talc, calcined clay, uncalcined clay, mica, phthalate such as glass; oxides such as titanium oxide and aluminum oxide; antimony compounds such as magnesium niobate, molten vermiculite, and crystalline vermiculite ; carbonates such as calcium carbonate, magnesium carbonate, hydrotalcite; oxides such as zinc oxide and magnesium oxide; hydroxides such as aluminum hydroxide, magnesium hydroxide, calcium hydroxide; barium sulfate, calcium sulfate, Sulfate or sulfite such as calcium sulfite; borate such as zinc borate, barium metaborate, aluminum borate, calcium borate, sodium borate; nitride such as aluminum nitride, boron nitride or tantalum nitride One or more of the powders and granules. Among them, from the viewpoint of improving the balance between mechanical properties and thermal conductivity, it is preferable to contain a carbon material, and more preferably at least one of graphite or carbon black.

Further, the present invention is not limited to the above-described embodiments, and modifications, improvements, etc. within a scope that can achieve the object of the invention are included in the present invention.

[Examples]

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

<Example: Production of Resin Sheet for Forming Electromagnetic Wave Absorbing Laminate>

In each of the examples, a resin sheet for forming an electromagnetic wave absorbing laminate was produced as follows.

First, a green body for forming a magnetic material layer is produced by the following method.

The composition of the binder resin A, the filler B, and the pulp C having an average particle diameter of 45 μm (50% by mass of the mass basis) obtained by pulverizing the atomizer by the amount shown in Table 1 is added as a constituent material. The mixture was stirred in water for 30 minutes using a disperser to obtain a mixture. Here, a total of 100 parts by weight of the constituent materials (adhesive resin A, filler B, and pulp C) was added to 10,000 parts by weight of water. Then, a coagulant D dissolved in water in an amount of 1% by weight based on the total amount of the above-mentioned constituent material and the coagulant D was added, and the constituent material was condensed into a floc. Next, the obtained coagulum was separated from the water using a 30 mesh metal mesh. Thereafter, the separated coagulum is used as a green body for forming a magnetic material layer. Further, in the case where the joint interface between the magnetic material layer and the conductive material layer in the electromagnetic wave absorbing laminate as the final product forms a zigzag structure, in the obtained body, the following is used to form a conductive material layer. The surface is processed in such a manner that the side of the blank is joined to obtain a desired zigzag structure.

Next, a green body for forming a conductive material layer is produced by the same method as the above-described green body for forming a magnetic material layer. Further, in the case where the joint interface between the magnetic material layer and the conductive material layer in the electromagnetic wave absorbing laminate as the final product forms a zigzag structure, in the obtained green body, the blank for forming the magnetic material layer Surface processing is performed in such a manner that the side of the body is joined to obtain the desired zigzag structure.

Next, after the obtained two kinds of green bodies (condensed materials) are laminated, the laminated body of the condensed material is subjected to dehydration pressing, and further dried in a drier at 50 ° C for 5 hours to be dried, thereby obtaining a composite resin composition. A resin sheet composed. The yield was 97%.

<Comparative Example: Manufacturing of Resin Sheet for Forming Electromagnetic Wave Absorbing Laminate>

For each comparative example, a resin sheet for forming an electromagnetic wave absorbing laminate was produced as follows.

The composition of the binder resin A, the filler B, and the pulp C having an average particle diameter of 45 μm (50% by mass of the mass basis) obtained by pulverizing the atomizer by the amount shown in Table 1 is added as a constituent material. The mixture was stirred in water for 30 minutes using a disperser to obtain a mixture. Here, a total of 100 parts by weight of the constituent materials (adhesive resin A, filler B, and pulp C) was added to 10,000 parts by weight of water. Then, a coagulant D dissolved in water in an amount of 1% by weight based on the total amount of the above-mentioned constituent material and the coagulant D was added, and the constituent material was condensed into a floc. Next, the obtained coagulum was separated from the water using a 30 mesh metal mesh. Thereafter, the separated coagulated product was subjected to dehydration pressing, and further dried in a drier at 50 ° C for 5 hours to obtain a resin sheet composed of a composite resin composition. The yield was 97%.

In each of the examples and the comparative examples, it was confirmed that the filler B was aligned in the direction of the plane of the resin sheet in the resin sheet. The details of each component shown in Table 1 are as follows. Further, the unit of the blending ratio of each component in Table 1 is % by weight.

(Binder Resin A)

‧Phenol resin: Resole phenolic resin (PR-51723, manufactured by Sumitomo Bakelite Co., Ltd.)

(filler B)

‧ Polyarsenamide fiber: fiber length 3mm, fiber width 12μm

‧Stainless steel fiber (SUS fiber): fiber length 5mm, fiber width 10μm

‧Small steel spherical powder (magnetic spherical powder): manufactured by Shanyang Special Steel Co., Ltd., FM79DF6H, average particle size 50μm

‧Suigang flat powder (magnetic flat powder): manufactured by Shanyang Special Steel Co., Ltd., FME3DH, long side 100μm, thickness about 3μm

(Pulp C)

‧ Polyarylamine pulp: Kevlar pulpl F303 (made by Toray DuPont Co., Ltd.)

(Coagulant D)

‧Synthetic bentonite: Sumecton (manufactured by KUNIMINE INDUSTRIES)

<Manufacture of Electromagnetic Wave Absorber>

The resin sheet obtained by the above method was subjected to heat treatment for 10 minutes under the conditions of a pressure of 300 kg/cm ² and a temperature of 180 ° C to prepare electromagnetic wave absorbers of the respective examples and comparative examples. Further, the electromagnetic wave absorber of the comparative example is not provided with a laminate of a conductive material layer and a magnetic material layer, and is composed of a single layer in which the conductive material and the magnetic material are contained in the same layer. In addition, in the following Table 1, this single layer is called a mixed layer, and shows the result of a comparative example.

Further, the thicknesses of the conductive material layer and the magnetic material layer in the electromagnetic wave absorber of the embodiment were each 1 mm. On the other hand, the electromagnetic wave absorber of the comparative example had a thickness of 2 mm.

The following evaluations were carried out using the electromagnetic wave absorbers of the examples and the comparative examples.

‧ Electromagnetic wave absorption amount of the electromagnetic wave absorber: First, the obtained electromagnetic wave absorber is cut into concentric shapes to prepare a test piece. Then, using the obtained test piece and network analyzer (manufactured by Agilent Technologies), electromagnetic waves of frequencies of 5 GHz, 8 GHz, 10 GHz, 12 GHz, 14 GHz, 16 GHz, and 18 GHz are performed by the coaxial tube method (according to the IEC 62333 specification). Determination of the amount of attenuation (electromagnetic wave absorption). Further, the coaxial tube used for the measurement was S-GPC7 (outer diameter: 6.97 mm, inner diameter: 3.05 mm) manufactured by KEYCOM. Furthermore, the unit of the electromagnetic wave absorption amount is %.

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

First, by the above method, the green body for forming the magnetic material layer and the green body for forming the conductive material layer are not laminated, and are respectively subjected to dehydration pressing, and further placed in a dryer at 50 ° C. It was dried in an hour to obtain a resin sheet composed of a composite resin composition. Next, the obtained resin sheet was heat-treated at a pressure of 300 kg/cm ² and a temperature of 180 ° C for 10 minutes to prepare a cured product. The cured product was cut into concentric shapes to prepare a test piece. Then, using the obtained test piece and a network analyzer (manufactured by Agilent Technologies, Inc.), the frequency of 5 GHz, 8 GHz, 10 GHz, 12 GHz, 14 GHz, and 16 GHz was obtained for the test piece by the coaxial tube method (according to the IEC 62333 specification). The amount of reflection attenuation of electromagnetic waves (electromagnetic wave reflection amount) of 18 GHz. Further, the coaxial tube used for the measurement was S-GPC7 (outer diameter: 6.97 mm, inner diameter: 3.05 mm) manufactured by KEYCOM. Furthermore, the unit of electromagnetic wave reflection amount is %.

‧ electromagnetic wave reflection amount Rc of the mixed layer: a test piece obtained by using a resin sheet having a thickness of 2 mm, which is formed by using a green body for forming a mixed layer produced by the above method, and The electromagnetic wave reflection amount Rc is obtained by the same method as the electromagnetic wave reflection amount Ra of the magnetic material layer and the electromagnetic wave reflection amount Rb of the conductive material layer.

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

The electromagnetic wave absorptive laminates of the examples are electromagnetic wave absorptive laminates which have good electromagnetic wave shielding properties and good electromagnetic wave absorptivity. Therefore, when the electromagnetic wave-absorbing laminated body of the embodiment is used to cover the surface of the electronic device as shown in FIG. 3(a), it is considered that the malfunction of the electronic device such as malfunction or malfunction can be effectively suppressed. On the other hand, the electromagnetic wave absorber of the comparative example was inferior in electromagnetic shielding properties as compared with the examples. Therefore, when the electromagnetic wave absorber of the comparative example is used to cover the surface of the electronic device as shown in FIG. 3(a), it is considered that the occurrence of a malfunction such as malfunction or malfunction of the electronic device cannot be suppressed to a level that satisfies the required level. .

Further, the constituent materials of the magnetic material layer and the conductive material layer of Example 1 were applied and dried to obtain a green body, and the green body layer was obtained by the volume layer. An electromagnetic wave absorber was produced in the same manner as in Example 1 using this resin sheet. As a result, the electromagnetic wave absorber also has good electromagnetic wave shielding properties and good electromagnetic wave absorptivity.

[Industrial availability]

The electromagnetic wave absorptive laminate of the present invention has a magnetic material layer formed of a first resin material and a conductive material layer formed of a second resin material containing a thermosetting resin and a conductive material, wherein the first resin material contains a thermosetting resin And particles and/or fibers composed of magnetic metal. Further, in the electromagnetic wave absorptive 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. The electromagnetic wave absorptive laminate that satisfies this condition can achieve both good electromagnetic wave shielding properties and good electromagnetic wave absorptivity. Therefore, when the surface of the electronic device (device) is covered by the electromagnetic wave absorbing laminate, it is possible to effectively suppress malfunctions such as malfunction or malfunction of the electronic device. Therefore, the present invention has industrial applicability.

Claims (13)

An electromagnetic wave absorptive laminate comprising: a magnetic material layer comprising: a first resin material comprising a thermosetting resin and particles and/or fibers composed of a magnetic metal; and a conductive material layer comprising: a heat hardening layer The resin is formed of a second resin material of a conductive material, and when the amount of electromagnetic wave reflection of the magnetic material layer is Ra, and the amount of electromagnetic wave reflection of the conductive material layer is Rb, the relationship of Ra ≦ Rb is satisfied. The electromagnetic wave absorptive laminate according to claim 1, wherein the conductive material is an alloy particle containing iron and aluminum. The electromagnetic wave absorptive laminate according to claim 1, wherein the conductive material is a magnetic particle processed into a flat shape. The electromagnetic wave absorptive laminate according to claim 1, wherein the particles made of the magnetic metal are alloy particles containing iron and aluminum. The electromagnetic wave absorptive laminate according to the first aspect of the invention, wherein the thermosetting resin contains one selected from the group consisting of a phenol resin, an epoxy resin, an unsaturated polyester resin, a melamine resin, and a polyurethane. Kind or more than two. An electromagnetic wave absorptive laminate according to claim 1, wherein the magnetic material layer is bonded to the conductive material layer. The electromagnetic wave absorptive laminate according to claim 1, 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. The electromagnetic wave absorptive laminate according to claim 1, wherein the magnetic material layer is composed of a paper-making body containing the first resin material. The electromagnetic wave absorptive laminate according to claim 1, wherein the conductive material layer is composed of a paper-making body containing the second resin material. A casing comprising the electromagnetic wave absorbing laminate of any one of claims 1 to 9. A method of using an electromagnetic wave absorbing laminate includes the steps of preparing an electromagnetic wave absorbing laminate according to any one of claims 1 to 9 and coating the surface of the electronic device with the electromagnetic wave absorbing laminate. The method of using an electromagnetic wave absorptive laminate according to claim 11, wherein the step of coating the surface of the electronic device includes the step of disposing the electromagnetic wave absorbing laminate in such a manner that the magnetic material layer faces the surface of the electronic device. The method of using the electromagnetic wave absorptive laminate according to claim 11, wherein the step of covering the surface of the electronic device comprises the step of disposing the electromagnetic wave absorbing laminate in such a manner that the conductive material layer faces the surface of the electronic device.