JP5220696B2 - Electromagnetic shielding molding material, electromagnetic shielding molding for electronic parts, electromagnetic shielding molding for building materials, and method for producing electromagnetic shielding molding material - Google Patents

Description

  The present invention relates to an electromagnetic shielding molding material for forming a molded article having electromagnetic shielding properties, an electromagnetic shielding member for an electronic component and an electromagnetic shielding building material formed from the electromagnetic shielding molding material, and the electromagnetic shielding properties. The present invention relates to a method for producing a molding material.

  An electronic component may be a noise source that emits an electromagnetic wave, or may malfunction due to the influence of the electromagnetic wave. Therefore, an electromagnetic shield may be applied to the electronic component. Also, in recent years, with the widespread use of PHS and wireless LAN, it is indispensable to prepare the radio environment in the office from the viewpoint of preventing information leakage and malfunction and noise due to external intrusion radio waves. For this reason, the necessity of applying electromagnetic shielding to building materials in buildings is also increasing.

  In general, electromagnetic shielding materials have higher electromagnetic shielding performance (especially electric field shielding performance) as the frequency is lower, but most of the frequencies of electromagnetic waves emitted from electronic components are 100 MHz or higher. Therefore, it is said that, for example, at least 10 to 30 dB is required for the electric field shielding performance in this frequency band. In recent years, malfunctions due to electromagnetic noise have become more and more problematic in electronic devices, and the electromagnetic shielding properties required for electronic parts and building materials have become higher.

  For such an electromagnetic shield, it has been conventionally proposed to use a molding material containing a carbon material such as a carbon nanotube. For example, in Patent Document 1, an electromagnetic shielding molded product is manufactured using a molding material made of a thermoplastic resin composition containing 0.5 to 20% by weight of carbon nanotubes and 5 to 50% by weight of conductive fibers. Is disclosed.

  However, carbon materials such as carbon nanotubes are bulky in conventional electromagnetic shielding molding materials, so there is a limit on the upper limit of the content thereof, and even if the content of carbon nanotubes is increased, matrix materials such as resins and ceramics are not suitable. As a result, the carbon material cannot be uniformly dispersed in the electromagnetic shielding molding material. Thus, the electromagnetic shielding characteristics of the molded product formed from the electromagnetic shielding molding material containing the carbon material are limited, and it is difficult to obtain a molded product having sufficient electromagnetic shielding properties over a wide frequency range. there were.

JP 2002-290094 A

  The present invention has been made in view of the above points, and is a molding material containing a carbon material such as a carbon nanotube, and can form a molded product having high electromagnetic shielding properties over a wide frequency range. An object of the present invention is to provide an electromagnetic shielding molding material, an electromagnetic shielding member for an electronic component and an electromagnetic shielding building material formed from the electromagnetic shielding molding material, and a method for producing the electromagnetic shielding molding material.

The electromagnetic shielding molding material according to the present invention contains mixed particles and a matrix material made of resin or ceramics , and the mixed particles are embedded in a copper powder having a number average particle size of 25 to 100 μm and the copper powder. It is characterized by comprising the carbon material .

  For this reason, even if the content of the carbon material in the electromagnetic shielding molding material is increased, the carbon material is mechanically integrated with the copper powder in the molding material, thereby reducing the volume of the carbon material. The material can be uniformly dispersed in the electromagnetic shielding molding material, and by this carbon material and copper powder, the molded article 1 formed from this electromagnetic shielding molding material has high electromagnetic shielding properties in a wide frequency range. Can be granted.

In this electromagnetic shielding molding material, the content of the carbon material is in the range of 24 to 40 % by mass .

  In this case, it is possible to form a molded article 1 having higher electromagnetic shielding performance in a wide frequency range from the electromagnetic shielding molding material.

Moreover, in this electromagnetic shielding molding material, copper content is the range of 40-70 mass% .

  In this case, it is possible to form a molded article 1 having higher electric field shielding performance in a wide frequency range from the electromagnetic shielding molding material.

  Moreover, it is preferable that content of the said copper is the range of 55-70 mass% further.

  In this case, the molded product 1 having not only high electric field shielding performance but also high magnetic field shielding performance can be formed from the electromagnetic shielding molding material.

  The electromagnetic shielding molded product 1a for electronic parts according to the present invention is obtained by molding the electromagnetic shielding molding material. Examples of the electromagnetic shielding molded product 1a for electronic parts include a case 2 and a sheet that cover elements, terminals, and the like on an electronic substrate.

  For this reason, it becomes possible to mold an electromagnetic shielding molding material even when the content of the carbon material is large. From this electromagnetic shielding molding material, an electromagnetic component for electronic parts having high electromagnetic shielding properties in a wide frequency range can be obtained. The shield molding 1a can be formed. For this reason, the electromagnetic shielding molding 1a for electronic parts having various shapes can be formed by molding or the like. The degree of freedom in designing the electromagnetic shielding molded product 1a is improved.

  The electromagnetic shielding molding for building materials according to the present invention is obtained by molding the electromagnetic shielding molding material.

  For this reason, it becomes possible to mold an electromagnetic shielding molding material even when the content of the carbon material is large. From this electromagnetic shielding molding material, an electromagnetic shielding for building materials having high electromagnetic shielding properties in a wide frequency range. Therefore, it is possible to form the electromagnetic shielding molding product 1a for building materials having various shapes by molding, etc., so that the electromagnetic shielding molding for building materials can be formed. The degree of freedom in designing the product 1a is improved.

The method for producing an electromagnetic shielding molding material according to the present invention is a method for producing the electromagnetic shielding molding material, wherein a copper powder having a number average particle size of 25 to 100 μm and a carbon material are mechanically integrated. After obtaining mixed particles composed of copper powder and a carbon material embedded in the copper powder, this is added to the matrix material, so that the content of the carbon material is in the range of 24 to 40% by mass, copper It is characterized by making content of 40 into the range of 40-70 mass% .

  Therefore, it is possible to reduce the volume of the copper powder and the carbon material before mixing with the matrix material, and to easily mix the matrix material, the copper powder and the carbon material even when the amount of the carbon material is increased. Become.

  As described above, according to the present invention, by increasing the content of the carbon material in the electromagnetic shielding molding material containing the carbon material such as the carbon nanotube, the electromagnetic shielding molding material can increase the electromagnetic wave in a wide frequency range. Molded products such as electromagnetic shielding molded products for electronic parts and electromagnetic shielding molded products for building materials having shielding properties can be formed.

(A) And (b) is a perspective view which shows an example of embodiment of this invention. It is a perspective view which shows the other example of embodiment of this invention. It is a microscope picture which shows the mixed powder obtained by mixing and knead | mixing copper powder and a carbon nanotube mechanically. It is a graph which shows the result of having measured the electric field shielding performance of the molded article obtained by the Example and the comparative example. It is a graph which shows the result of having measured the magnetic field shielding performance of the molded article obtained by the Example and the comparative example.

  Hereinafter, modes for carrying out the present invention will be described.

  The electromagnetic shielding molding material according to the present embodiment contains a copper powder, a carbon material, and a matrix material.

  The number average particle diameter of copper powder (number average particle diameter measured when model ethyl SALD3000 manufactured by Shimadzu Corporation is used and methyl ethyl ketone is used as the dispersion) is preferably in the range of 25 to 100 μm. In this case, the dispersibility in the matrix resin of the mixed particles in which the copper powder and the carbon material are mechanically integrated becomes very high.

  The mechanical integration means that the carbon material is embedded in the copper powder, so that it can be regarded as an integral particle.

  As the carbon material, it is preferable to use nanocarbon, and it is particularly preferable to use carbon nanotubes. Although it does not specifically limit as a carbon nanotube, For example, Showa Denko Co., Ltd. vapor phase method carbon fiber (Brand name "VGCF": Diameter 150nm, length 10-20micrometer, multiwall) can be used. Of course, the present invention is not limited to this, and any carbon nanotube having a diameter of 1 to 200 nm and a length of 0.5 to 20 μm may be used. Moreover, it is not limited to a multiwall, and may be a single wall or cup stack type carbon nanotube. In addition to carbon nanotubes, carbon materials such as fullerenes, carbon nanocoils, carbon nanohorns, carbon onions, nanopeabots, carbon nanoribbons, carbon black, graphite, expanded graphite, carbon fibers, activated carbon, activated carbon fibers, carbon Carbon materials such as microcoils, coke, and coal tar pitch can also be used. Carbon materials may be used alone or in combination of two or more.

  As the matrix material, a resin material or a ceramic material can be used.

  As the resin material, an appropriate thermoplastic resin or thermosetting resin can be used. Although it does not specifically limit as a thermoplastic resin, For example, polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS), ABS resin, methacrylic resin (PMMA), polymethylpentene (trademark: TPX) ), Polyamide (PA), polyacetal (POM), polycarbonate (PC), polyphenylene oxide (PPO), polyphenylene ether (PPE), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polyethylene naphthalate (PEN), poly Tetrafluoroethylene (PTFE), perfluoroalkyl vinyl ether (PFA), polyvinyl fluoride (PVF), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PC) FE), polyphenylene sulfide (PPS), polysulfone resin (PSF), polyarylate (PAR), polyetherimide (PEI), polyimide (PI), polyetherketone (PEK), polyetheretherketone (PEEK), liquid crystal Examples thereof include a polymer (LCP) and a polyamideimide (PAI). Thermosetting resins include phenolic resin (PF), epoxy resin (EP), urea resin (UF), melamine resin (MF), polyurethane resin (PU), unsaturated polyester (UP), silicone resin, dicyclo Examples include pentadiene (DCPD) and triazine (BT). In addition to using one kind of resin material alone, a polymer alloy obtained by blending two or more kinds may be used. Further, a thermosetting rubber or a thermoplastic elastomer may be used.

  The ceramic material is not particularly limited, and examples thereof include alumina, aluminum nitride, silicon nitride, silicon carbide, boron nitride, barium titanate, and PZT. Ceramic materials may be used alone or in combination of two or more.

  An electromagnetic shielding molding material can be prepared by mixing the copper powder, carbon material and matrix material as described above. By mixing the carbon material with the copper powder in the matrix material in this way, the carbon material is mechanically integrated with the copper powder in the molding material to reduce the volume of the carbon material, and a large amount of carbon material is electromagnetically shielded. It becomes possible to disperse uniformly in the material, and the content of the carbon material in the electromagnetic shielding molding material can be increased.

  Since this electromagnetic shielding molding material can increase the content of the carbon material and contains the copper powder together with the carbon material, the electromagnetic shielding performance of the molded product 1 formed from this electromagnetic shielding molding material is improved. It can be improved over a wide frequency range (for example, 1 to 1000 MHz).

  Although content of the carbon material in an electromagnetic shielding molding material is set suitably, it is preferred that it is the range of 21-80 mass%. In this way, by increasing the content of the carbon material in the electromagnetic shielding molding material to 21% by mass or more, the electromagnetic shielding performance of the molded product 1 formed from the electromagnetic shielding molding material is further increased over a wide frequency range. The electric field shielding performance measured in accordance with the KEC method of the Kansai Electronics Industry Promotion Center in the frequency band of 1 to 100 MHz of the molded product 1 can be increased to 10 dB or more. . Moreover, the favorable moldability of an electromagnetic shielding molding material can be maintained because content of the carbon material in an electromagnetic shielding molding material shall be 80 mass% or less. In order to improve the moldability of the electromagnetic shielding molding material and the electromagnetic shielding performance of the molded product 1 in a well-balanced manner, the carbon material content in the electromagnetic shielding molding material is particularly in the range of 24 to 40% by mass. It is preferable that

  Moreover, although content of the copper powder in an electromagnetic shielding molding material is also set suitably, it is preferable that it is the range of 40-70 mass%. In this case, the electric field shielding performance of the molded product 1 formed from the electromagnetic shielding molding material can be further improved over a wide frequency range, and the molded product 1 in the frequency band of 1 to 100 MHz is Kansai Corporation. The electric field shielding performance measured in accordance with the KEC method of the Electronics Industry Promotion Center can be 50 dB or more. In particular, if the content of the copper powder in the electromagnetic shielding molding material is in the range of 46 to 55% by mass, the electric field shielding performance of the molded product 1 can be further improved.

  Moreover, it is also preferable to make content of the copper powder in an electromagnetic shielding molding material into the range of 55-70 mass%. In this case, the electric field shielding performance of the molded product 1 can be improved, and the magnetic field shielding performance can be further improved over a wide frequency range. Moreover, in order to improve the moldability of the electromagnetic shielding molding material and the electromagnetic shielding performance of the molded product 1 in a well-balanced manner, the copper powder content in the electromagnetic shielding molding material is particularly in the range of 55 to 65 mass%. It is preferable that

  In preparing the electromagnetic shielding molding material, the copper powder, the carbon material, and the matrix material can be mixed by an appropriate method according to the properties of the matrix material.

  For example, when the matrix material is a resin material, an electromagnetic shielding molding material can be prepared by heating and kneading a mixture obtained by adding copper powder and a carbon material to the resin material. Alternatively, the electromagnetic shielding molding material after kneading may be tableted and formed into a pellet.

  When the matrix material is a ceramic material, an electromagnetic shielding molding material is prepared by stirring and mixing a mixture obtained by adding copper powder and a carbon material to a powdered ceramic material with an appropriate stirring mixer. be able to.

  In preparing the electromagnetic shielding molding material as described above, it is preferable to mechanically integrate the copper powder and the carbon material in advance before mixing the matrix material, the copper powder and the carbon material. .

  As a method for mechanically integrating the copper powder and the carbon material, for example, a predetermined amount of the copper powder and the carbon material may be mixed and kneaded by a ball mill. The material of the pot and ball in the ball mill may be an appropriate material such as stainless steel. The mechanically integrated copper powder and carbon material are preferably made uniform in particle size by, for example, sieving.

  FIG. 3 shows a micrograph of a mixed powder obtained by mixing and kneading copper powder and carbon nanotubes for 180 minutes with a stainless steel ball mill. Thus, the copper powder and the carbon nanotube can be mechanically integrated by embedding the carbon nanotube in the copper powder by mixing and kneading using a ball mill or the like.

  When the copper powder and the carbon material previously mechanically integrated in this way are mixed with the matrix material, the copper powder and the carbon material can be mixed with the matrix material in a state where the volume of the copper powder and the carbon material is reduced. Even if the amount of the carbon material is increased, it becomes easy to uniformly mix the matrix material, the copper powder, and the carbon material. Further, when the copper powder and the carbon material are mixed and kneaded by the ball mill in this way, the shape of the particles of the mixed powder of the copper powder and the carbon material becomes a scaly shape. As a result, the shrinkage rate of the molded product 1 formed from the electromagnetic shielding molding material is reduced and the dimensional accuracy is increased.

  The molded product 1 having electromagnetic shielding properties can be formed by molding the electromagnetic shielding molding material adjusted in this way by an appropriate method according to the properties of the matrix material. For example, when the matrix material is a resin material, the electromagnetic shielding molding material is molded by various known molding methods such as injection molding, extrusion molding, compression molding, blow molding and injection compression molding, and the molded product 1 (resin molded body). ) Can be obtained. In addition, when the matrix material is a ceramic material, after adding a binder to the electromagnetic shielding molding material as necessary, it is molded by injection molding or the like, and the obtained molded body is heated and degreased as necessary By firing, a molded article 1 (sintered body) having electromagnetic shielding properties can be obtained.

  Since the carbon material content can be increased in the molded product 1 thus obtained, high electromagnetic shielding properties can be imparted. As such a molded product 1, various members for electromagnetic shielding can be obtained.

  For example, by molding an electromagnetic shielding molding material, an electromagnetic shielding molded product 1a for an electronic component that performs electromagnetic shielding of an electronic component can be obtained as the electromagnetic shielding molded product 1. Examples of the electromagnetic shielding molded product 1a for electronic parts include an electromagnetic shielding case 2 and a sheet that cover an electronic part that is a source of electromagnetic waves and an electronic part that is susceptible to electromagnetic waves. In this case, the moldability at the time of molding of the electromagnetic shielding molded product 1a for electronic parts is excellent, and the design flexibility of the electromagnetic shielding molded product 1a for electronic parts is further improved.

  FIG. 1 shows an example in which an electromagnetic shielding case 2 is attached to a wiring board 6 on which a semiconductor element 7 is mounted. As shown in FIG. 1A, a conductor wiring 8 connected to the semiconductor element 7 and a ground pattern 9 are formed on one surface of the wiring substrate 6. The semiconductor element 7 is fixed to one surface of the wiring substrate 6 and is electrically connected to the conductor wiring 8 via the bonding wire 10.

  On the other hand, the case 2 is formed in a container shape with only the lower surface opened. Further, the case 2 is provided with connection terminals 5 connected to the ground pattern 9 on the wiring board 6. The connection terminal 5 is formed on the outer surface of the case 2 at a position that matches the ground pattern 9 on the wiring board 6. The connection terminal 5 can be formed, for example, by a method similar to that employed for forming a conductor wiring on an MID (Molded Interconnect Devices) substrate. Specifically, for example, after forming a metal film on the case 2 by an appropriate technique such as sputtering, the outline of the connection terminal is drawn using an appropriate technique such as photolithography, ink jet, screen printing, or laser outline removal method. Further, the connection terminal 5 can be formed by sequentially performing electrolytic copper plating, soft etching, electrolytic nickel plating, and electrolytic gold plating.

  As shown in FIG. 1B, the case 2 has the semiconductor element 7 in a state where the ground pattern 9 on the wiring board 6 and the connection terminal 5 in the case 2 are aligned with one surface of the wiring board 6. It is attached to cover. The ground pattern 9 on the wiring board 6 and the connection terminal 5 in the case 2 are conductively connected by solder 11.

  By attaching the electromagnetic shielding case 2 to the wiring board 6 in this way, it is possible to suppress the electromagnetic wave generated from the semiconductor element 7 from leaking to the outside, and the external electromagnetic wave reaches the semiconductor element 7. Can be cut off. In addition, since the electromagnetic shielding case 2 is connected to the ground pattern 9 of the wiring board 6 through the connection terminal 5, the ground pattern 9 on the wiring board 6 can be used when connecting the case 2 to the ground. Therefore, it is possible to save the space of the mounted parts.

  FIG. 2 shows an example in which the electromagnetic shielding case 2 is a housing constituting a connector (optical connector) provided at the tip of the optical cable 3. The case 2 covers the connection terminal 4 provided at the tip of the optical cable 3. For this reason, it is possible to suppress the electromagnetic wave generated from the connection terminal 4 from leaking to the outside, and to block the external electromagnetic wave from reaching the connection terminal 4.

  In producing such an electromagnetic shielding molding product 1a for electronic components, various functions are imparted to the electromagnetic shielding molding product 1a for electronic components by including an appropriate material in the electromagnetic shielding molding material. You can also. For example, when polyimide is used as at least part of the matrix material in the electromagnetic shielding molding material, the solder adhesion of the electromagnetic shielding molding product 1a for electronic parts such as the case 2 is increased. In this case, the electromagnetic shielding molded product 1a for electronic components such as the case 2 can be easily attached to the wiring substrate by solder-connecting the electromagnetic shielding molded product 1a for electronic components to the wiring substrate.

  Moreover, the electromagnetic shielding molding product for building materials can be obtained as the electromagnetic shielding molding 1 by molding the electromagnetic shielding molding material. Examples of the building material molded product 1 include building wall materials, floor materials, and ceiling materials. Use of such electromagnetic shielding moldings for building materials can prevent information leakage at offices, offices, etc., and prevent malfunctions and noise caused by intruding radio waves from outside. Will be able to.

  In producing such an electromagnetic shielding molded product for building materials, various functions can be imparted to the electromagnetic shielding molded product for building materials by including an appropriate material in the electromagnetic shielding molding material. For example, when polytetrafluoroethylene is used as at least part of the matrix material in the electromagnetic shielding molding material, high water repellency can be imparted to the electromagnetic shielding molding for building materials.

  Hereinafter, the present invention will be described in more detail by presenting specific examples of the present invention.

(Examples 1-4)
About each Example, what was shown in following Table 1 was used as a material for preparing an electromagnetic shielding molding material. The matrix material is 9T nylon (trade name “Genesta N1000” manufactured by Kuraray Co., Ltd.), the copper powder has a number average particle size of 75 μm, and the carbon nanotube is a vapor grown carbon fiber manufactured by Showa Denko KK The name “VGCF”: diameter 150 nm, length 10-20 μm, multiwall) was used.

  When preparing the electromagnetic shielding molding material, first, copper powder and carbon nanotubes were blended, and this was mixed and kneaded in a stainless steel ball mill for 180 minutes. The mixed powder thus obtained is passed through a sieve having an opening of 150 μm to make the particle size uniform, then blended with a matrix material, mixed and kneaded to form a powdery electromagnetic shielding property having a particle size of 250 μm or less. Obtained material.

(Comparative Examples 1-3)
About each comparative example, what was shown in following Table 1 was used as a material for preparing an electromagnetic shielding molding material. The matrix material is 9T nylon (trade name “Genesta N1000” manufactured by Kuraray Co., Ltd.), the Al powder has a number average particle size of 100 μm, and the carbon nanotubes are vapor-grown carbon fibers manufactured by Showa Denko KK The name “VGCF”: diameter 150 nm, length 10-20 μm, multiwall) was used.

  When preparing the electromagnetic shielding molding material, first, Al powder and carbon nanotube were blended, and this was mixed and kneaded for 180 minutes with a stainless steel ball mill. The mixed powder thus obtained is passed through a sieve having an opening of 150 μm to make the particle size uniform, then blended with a matrix material, mixed and kneaded to form a powdery electromagnetic shielding property having a particle size of 250 μm or less. Obtained material.

(Comparative Example 4)
The materials shown in Table 1 below were used as materials for preparing the electromagnetic shielding molding material. The matrix material is 9T nylon (trade name “Genesta N1000” manufactured by Kuraray Co., Ltd.), and the carbon nanotube is vapor grown carbon fiber manufactured by Showa Denko KK (trade name “VGCF”: diameter 150 nm, length 10 to 20 μm). , Multiwall) were used respectively.

  When preparing the electromagnetic shielding molding material, carbon nanotubes and a matrix material were blended and mixed and kneaded to obtain a powdery electromagnetic shielding molding material having a particle size of 250 μm or less.

(Comparative Example 5)
The materials shown in Table 1 below were used as materials for preparing the electromagnetic shielding molding material. As the matrix material, 9T nylon (manufactured by Kuraray Co., Ltd., trade name “Genesta N1000”) and copper powder having a number average particle diameter of 75 μm were used.

  When preparing the electromagnetic shielding molding material, copper powder and matrix material were blended, mixed and kneaded to obtain a powdery electromagnetic shielding molding material having a particle size of 200 μm or less.

(Electromagnetic shield performance evaluation)
The electromagnetic shielding material obtained in each of the examples and comparative examples is heated at a molding temperature of 300 to 350 ° C. with a mold having a cavity of 100 mm × 100 mm, applied with a pressing force of 5 kN, and then rapidly cooled. Thus, a molded product 1 having a size of 100 mm × 100 mm × 1 mm was obtained.

  The electric field shielding performance and magnetic field shielding performance in the frequency band of 1 MHz to 1000 MHz (1 GHz) of the molded product 1 were measured according to the KEC method of the Kansai Electronics Industry Promotion Center. The measurement result of the electric field shielding performance is shown in FIG. 4, and the measurement result of the magnetic field shielding performance is shown in FIG. Table 1 below shows the measurement results of the electric field shielding performance and the magnetic field shielding performance when the frequencies are 10 MHz and 100 MHz.

According to this result, in Examples 1 to 4, the content of carbon nanotubes in the molding material can be improved, and these molded articles 1 have a high electric field shielding performance as shown in FIG. In particular, in Examples 1 and 2 where the copper contents were 55% by mass and 46% by mass, respectively, the electric field shielding performance was remarkably high.

  On the other hand, Comparative Examples 1 to 3 contained aluminum powder and the content of carbon nanotubes could be improved as in Comparative Examples 1 and 3, but the electric field shielding performance was poor. Further, in Comparative Example 4 in which only the carbon nanotube was contained in the matrix material, the electric field shielding property was higher than in Comparative Examples 1 to 3, but it was not sufficient as compared with Examples 1 to 4. Further, in Comparative Example 5 in which only the copper powder is contained in the matrix material, the electric field shielding property may be higher than that in Example 3 or Example 4 in the high frequency band, but when the entire range from 1 MHz to 1000 MHz is seen. The electric field shielding property was low, and in Comparative Example 5, the moldability was poor, and the molded product 1 was cracked even when a slight impact was applied.

  Further, as shown in FIG. 5, in Example 1 in which the content of the copper powder in the molding material was 55% by mass, not only the electric field shielding property but also the magnetic field shielding performance was particularly high.

1 Molded product 1a Electromagnetic shielding molded product for electronic parts

Claims (5)

And mixed particles, containing a matrix material comprising a resin or a ceramic, wherein the mixed particles are, the copper powder having an average particle diameter of 25 to 100 m, Ri Do and a carbon material is embedded in the copper powder, a carbon material content is in the range of 24 to 40 wt%, the electromagnetic shielding molded material content of copper and said range der Rukoto of 40 to 70 wt%. The electromagnetic shielding molding material according to claim 1 , wherein the copper content is in the range of 55 to 70 mass%. Claim 1 or 2 for electronic components electromagnetic shielding molded article characterized by being obtained by molding the electromagnetic shielding molded material according to. An electromagnetic shielding molding product for building materials, which is obtained by molding the electromagnetic shielding molding material according to claim 1 or 2 . A method for producing the electromagnetic shielding molding material according to claim 1 or 2 , wherein the copper powder and the carbon material having a number average particle diameter of 25 to 100 µm are mechanically integrated to thereby form a copper powder, After obtaining mixed particles consisting of a carbon material embedded in copper powder, by adding this to the matrix material , the carbon material content is in the range of 24 to 40% by mass, and the copper content is 40 to 40%. The manufacturing method of the electromagnetic shielding molding material characterized by setting it as the range of 70 mass% .