JP2000082895A - Conductive panel material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low-cost conductive panel material which comprises an electromagnetic wave shielding characteristics, conductivity, and heat- generation characteristics while excellent in energy efficiency. SOLUTION: A conductive powder comprising at least a sericite, etc., which is a conductive material comprising PTC characteristics or a carbon group powder material and an inorganic glue are kneaded to form a plate-like or sheet-like panel material 10. The conductor powder comprises a self-temperature- control function. Related to an inorganic glue, a calcium oxide or silicon oxide, for example, is a main component while a baked carbon powder is used for a carbon group powder material.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electromagnetic wave shield and a conductive panel material that generates heat by conduction.

[0002]

2. Description of the Related Art Conventionally, as a panel material having conductivity, a resin-based or rubber-based conductive resin material in which particles of metal or carbon are mixed or small pieces are known. In some cases, a heater was buried under the sidewalk for melting snow on the sidewalk.

On the other hand, as a panel material having an electromagnetic shielding property, for example, there is a precast concrete plate in which a chop of carbon fiber is mixed. This precast concrete plate is used for building exterior walls and partitions to prevent electromagnetic waves from entering the building,
This is to prevent malfunctions of medical equipment and electronic equipment in general.

[0004]

In the case of the above-mentioned resin-based panel material of the prior art, it has been difficult to obtain a uniform shielding effect over a wide area in order to improve the electromagnetic wave shielding effect and conductivity. Further, the heat resistance temperature of the resin-based panel material is relatively low, and there is a risk that the properties of the resin may change or the panel material may be deformed by heating for a long time. In addition, they are difficult to increase in size and have a high cost. Further, those in which a heater is buried in the sidewalk also have problems such as the cost and durability of the heater, the temperature control is difficult, and the waste of energy due to heating is large.

[0005] In the latter case of the prior art, the cost of carbon fibers is high, and it is difficult to uniformly disperse them in concrete.

The present invention has been made in view of the above-mentioned conventional problems, and has as its object to provide an inexpensive conductive panel material which has electromagnetic wave shielding properties, conductivity and heat generation, has good energy efficiency, and is inexpensive. It is what it was.

[0007]

A conductive panel material according to the present invention comprises kneading a conductive powder containing at least one of carbon, such as sericite, which is a conductive material having PTC characteristics, and an inorganic glue. Or a sheet-like conductive panel material formed in this way. The inorganic glue contains calcium oxide or silicon oxide as a main component. The conductor powder has a self-temperature control function. Also,
As the carbon-based powder material, calcined carbon powder is preferable in terms of cost.

The carbon powder material and the inorganic glue are kneaded to form a plate-like or sheet-like panel material, and a plurality of wire nets separated from each other by a predetermined distance are provided in the panel material. Connect the wire mesh alternately to the negative and positive electrodes,
Further, it is also possible to supply electricity to the wire mesh to generate heat in the panel material between the wire meshes.

By applying an insulating resin to the surface of the panel material and providing a reinforcing layer having thermal conductivity or the like on the surface of the insulating resin, it can be used for various applications.

[0010]

Embodiments of the present invention will be described below. The conductive panel material 10 is obtained by mixing lime (calcium oxide) or silicon oxide, which is an inorganic adhesive agent, with carbon powder and sericite powder, which is a conductive mica, into a plate-shaped or sheet-shaped mold and pressing. It is formed.

The conductive panel material 10 contains 20 to 70% of calcined carbon powder and 30 to 60% of calcium oxide.
%, Diatomaceous earth and silica sand 10 to 50%, sand and sandstone 10
20% or the like is mixed, and aluminum powder or the like is mixed in an amount of about 10 to 20% in order to further strengthen the strength and improve the heat conductivity. Further, an appropriate amount of sericite powder is added. This sericite may be used instead of carbon or aluminum or may be mixed.

On the other hand, inside the conductive panel material 10, as shown in FIG. 1, rectangular wire meshes are provided separately for a predetermined time and provided in an independent state. Connected to the wiring 12 connected to the negative electrode, a positive electrode wire mesh 14 and a negative electrode wire mesh 16 are formed. Here, the positive electrode wire mesh 14 and the negative electrode wire mesh 16 are provided adjacent to each other. The conductive panel material 10 between the metal meshes 14 and 16 generates heat due to energization, and is maintained at a constant temperature after being entirely heated. At this time, by mixing a porous material into the conductive panel material 10, good heat retention and heat insulation can be obtained.

Further, as shown in FIG. 2, an insulating resin 18 is applied to the entire surface of the conductive panel material 10, and a material having good thermal conductivity or aluminum as a strength reinforcing material is coated on the outside of the insulating resin 18. The reinforcing layer 20 made of iron, resin, or the like may be formed. Thereby, it can be embedded in the outer wall of a building material or a road and used for various purposes such as road heating.

The conductive panel material 10 of this embodiment
By changing the mixing ratio of calcined carbon powder, calcium oxide, or silicon oxide, a shielding effect suitable for the intended use can be obtained. Also, by changing the ratio of sericite to another conductor, the upper limit of the control temperature due to the PTC characteristics can be adjusted.

According to the conductive panel material 10 of this embodiment, the carbon involved in the conductivity and the electromagnetic wave shielding performance is made into inexpensive calcined carbon, and furthermore, aluminum powder, which is industrial waste, is added. It can be manufactured at very low cost and with good conductivity. In addition, by mixing sericite, self-temperature control based on PTC characteristics is performed, and the temperature automatically works at an optimum temperature, and energy efficiency is high.

The conductive panel material of this embodiment is not limited to the above-described embodiment, and the material forming the panel material and the mixing ratio can be appropriately selected.
In addition to the wire mesh, other metal materials or other members may be used for the electrode, and an aluminum mesh may be used for the electrode. Materials other than sericite may be used as the material having PTC characteristics.

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the conductive panel material of the present invention will be described below. The conductive panel material 10 of this embodiment includes:
The resistivity between the electrodes is about 0.6 Ωm, for example, 15 c
Conductive panel 10 having a thickness of about 1 cm to about 50 cm square and about 50 cm square
When the calorific value of the conductive panel 1 was measured using a 100 V power supply, a current of about 2.5 A was supplied.
0 could be connected in series and in parallel, and the total resistance could be set to be 40Ω to 20Ω. And, in this state, heat generation of 250 to 500 kcal was obtained.

Next, using the conductive panel material of the present invention,
FIGS. 3 to 5 show the results of measuring the electric field and the shielding effect up to a frequency of 1000 MHz by changing the mixing ratio of calcium oxide and silicon oxide involved in the electromagnetic shielding effect, and the firing system carbon.

Here, the ratio of the glue such as calcium oxide to the carbon of the firing system is 60:40 (FIG. 3), respectively.
A panel material having a thickness of about 1 cm was measured at 40:60 (FIG. 4) and 30:70 (FIG. 5). As a result, as shown in FIG. 5, the best shielding effect was obtained when the mixing ratio was 15% of calcium oxide, 15% of silicon oxide, and 70% of carbon in the firing system.

Further, when the temperature rise in the case of being used as a snow melting device by laying in a roadbed was measured, this panel material was laid at 2.5 A and 250 W with a 100 V power supply, and the surface temperature was measured. As a result, at a temperature of 18 ° C,
After 5 minutes, the surface temperature was 30.09 ° C., and after 20 minutes 37.degree.
The temperature reached 65.degree. C., 40.86.degree. C. after 40 minutes, and then reached an equilibrium state.

[0021]

The conductive panel material of the present invention has a good shielding effect and, by providing a heat-generating electrode, has excellent heat generation and moderate heat retention. In addition, since it can be manufactured at low cost, it can be used in the same manner as general building materials, is widely used, and is easy to use and handle.

[Brief description of the drawings]

FIG. 1 is a plan view showing a conductive panel material according to an embodiment of the present invention.

FIG. 2 is a longitudinal sectional view showing a conductive panel material according to one embodiment of the present invention.

FIG. 3 is a graph showing an electrolytic shielding effect of a conductive panel material according to one embodiment of the present invention.

FIG. 4 is a graph showing an electrolytic shielding effect of a conductive panel material according to another embodiment of the present invention.

FIG. 5 is a graph showing an electrolytic shielding effect by a conductive panel material according to still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Conductive panel material 12 Wiring 14 Positive wire mesh 16 Negative wire mesh 18 Insulating resin 20 Reinforcing layer

Claims (6)

[Claims] 1. A plate-like or sheet-like conductive panel material formed by kneading a conductive powder containing carbon and an inorganic adhesive material. 2. A plate-shaped or sheet-shaped conductive panel material formed by kneading a conductive powder containing a conductive material having PTC characteristics and an inorganic adhesive material. 3. The conductive panel material according to claim 3, wherein the conductive material having PTC characteristics is sericite. 4. The conductive panel material according to claim 1, wherein the inorganic glue is mainly composed of calcium oxide or silicon oxide. 5. A panel material formed by kneading the conductive powder material and an inorganic glue material and compressing it into a plate or a sheet, and a plurality of panels separated from each other by a predetermined distance in the panel material. 5. The conductive panel material according to claim 1, wherein said wire mesh is connected to a negative electrode and a positive electrode alternately, and electricity is supplied to said wire mesh to generate heat in said panel material between each wire mesh. 6. The conductive panel material according to claim 5, wherein an insulating resin is applied to a surface of the panel material having the wire net therein, and a reinforcing layer is provided on the surface of the insulating resin.