JP3222649U - Carbon coated surface heater - Google Patents

Abstract

A carbon-coated planar heater that uses a conductive carbon material and is excellent in safety and durability at low cost. SOLUTION: A carbon coated paper 2A, which is a conductive sheet formed by attaching a conductive carbon material having a smaller diameter than the fiber to the fiber surface of a sheet-like fiber structure, generates heat by energizing the carbon coated paper 2A. In the carbon-coated sheet heater, resin coated layers 3B and 3A made of a nonconductive resin are formed on both front and back surfaces of the carbon coated paper 2A, and the nonconductive resin penetrates into the carbon coated paper 2A and is coated with resin. In the state where the intermediate part sandwiched between the layers 3B and 3A is deaerated, the non-conductive resin on the front and back sides and the intermediate part is cured, so that the intermediate part having the carbon coated paper 2A does not contain air. Sealed and waterproof inside and outside and inside and outside. [Selection] Figure 3

Description

  The present invention relates to a carbon-coated planar heater provided with a resin coating layer on the front and back of a conductive sheet obtained by attaching a conductive carbon material to the fiber surface of a fiber structure.

  In recent years, a technique for creating a conductive sheet or a planar heater by attaching a fine conductive carbon material such as carbon graphite or carbon nanotube to a fiber surface such as paper or cloth has become widespread. For example, Japanese Patent No. 4502182 discloses a technique for obtaining a sheet heater by applying a solution in which carbon black or carbon graphite is dispersed to a fiber fabric. Also disclosed is a technique in which carbon short fibers are diffused and mixed to form a planar heater.

  In this way, a planar heater can be created by simply attaching a fine conductive carbon material to the fiber surface, but paper is low cost but weak against water, has low strength, and leaks. There is a difficulty that it is easy, and in the case of the fabric, although it has a relatively high strength, it has a common problem that it is easy to cause electric leakage. Therefore, in both cases, measures are taken such as covering the surface of the heating element of the planar heater with a waterproof insulating sheet.

  However, since the above-described planar heater is a system in which conductive carbon attached to the fiber surface is energized to generate heat, the fiber may ignite and cause a fire accident when the temperature rises excessively. In addition, since conductive carbon easily oxidizes when exposed to air, even if the surface is covered with an insulating sheet, air exists in the voids of the fiber and can enter and exit, so there is a concern of deterioration due to aging. The

  On the other hand, a graphite sheet can be obtained by rolling a naturally occurring graphite or baking an organic synthetic film in the absence of oxygen, and this can be used as a planar heater. Although this graphite sheet is relatively resistant to deterioration but has low mechanical strength, as described in JP-A-2006-134672, the reinforcing sheets of the axial fabric are stacked and the insulating films are stacked on the upper and lower sides thereof. Then, this is bonded and fixed with a resin between a pair of upper and lower panel blocks to form a heat generating block.

  With such a configuration, a planar heater having mechanical strength and durability can be obtained. However, although the graphite sheet is less likely to ignite or deteriorate, the graphite sheet is likely to be more expensive than the fiber structure described above, and the difference is significant compared to the paper sheet. In addition, since it is configured to be sandwiched between hard plates such as panel blocks for the purpose of increasing mechanical strength, the cost tends to be further increased and the degree of freedom of shape as a planar heater tends to be poor.

Japanese Patent No. 4502182 Japanese Patent Laid-Open No. 8-31553 JP 2006-134672 A

  The present invention is intended to solve the above-described problems, and it is an object of the present invention to provide a carbon-coated surface heater using a conductive carbon material that is excellent in safety and durability at a low cost. And

  Accordingly, the present invention is provided with a conductive sheet in which a conductive carbon material having a diameter smaller than that of the fiber is attached to the fiber surface of the sheet-like fiber structure, and a carbon-coated surface that generates heat by energizing the conductive sheet. In the heater, a resin coat layer made of a non-conductive resin is formed on both the front and back surfaces of the conductive sheet, and the intermediate portion sandwiched between the resin coat layers by the non-conductive resin permeating the conductive sheet is removed. The non-conductive resin on the front and back sides and the middle part was cured in the aired state, so that the middle part having the conductive sheet was sealed in a state not including air, and had waterproofness inside and outside and inside and outside insulation. It was supposed to be a characteristic.

  Thus, by providing a non-conductive resin coat layer on the front and back of a conductive sheet made by attaching a conductive carbon material to the fiber surface of a sheet-like fiber structure such as cloth or paper, the mechanical strength is improved. In the present invention, a portion that is degassed while infiltrating a non-conductive resin into a conductive sheet made of a fiber structure and sandwiched between the inner and outer resin coat layers. By adopting a structure that does not contain air, the resin coating layers on the front and back sides are integrated via an intermediate conductive sheet that is a fiber component, so that the mechanical strength is further increased without excessive cost increase. Excellent waterproofness and insulation are realized, and the conductive sheet is sealed except for air in the middle portion, so that there is no fear that the conductive sheet will burn or deteriorate.

  Further, in this carbon-coated planar heater, if at least one of the front and back resin coat layers is made of a fiber reinforced resin, and constitutes one FRP molded body as a whole, The fiber structure of the conductive sheet is also more excellent in mechanical strength while being integrated with the resin coating layer together with the FRP reinforcing fiber, making it difficult to cause deterioration in waterproofness and insulation due to cracks and breaks. In addition, if a prepreg sheet in which a reinforcing fiber is impregnated with a resin is used, the manufacturing procedure becomes extremely easy.

  Furthermore, in the above-described carbon-coated planar heater, if the non-conductive resin is a thermosetting resin, a planar heater having excellent heat resistance can be easily created in a short time. In addition, the manufacturing method and manufacturing equipment for the FRP molded body can be applied as they are.

  Furthermore, in the above-described carbon-coated planar heater, the conductive carbon material is at least one selected from the group consisting of carbon black, carbon microfiber, carbon nanotube, and carbon nanohorn. For example, in addition to being easy to make thin as a planar heater, it is easy to realize excellent energy efficiency and quick rise of heating.

  In addition, in the above-described carbon-coated planar heater, if the fiber structure is paper, it is easy to simply apply and dry a solution in which a conductive carbon material is dispersed. In addition to being able to obtain a uniform conductive sheet with excellent heat generation at low cost and easy to process into various shapes, the set temperature can be easily changed simply by changing the coating concentration. It becomes.

  In addition, in the above-described carbon-coated planar heater, a heat reflecting sheet that reflects far-infrared rays is arranged on one surface side of the conductive sheet in a state that is parallel and not electrically connected to the conductive sheet. If the far-infrared ray is reflected toward the side where the heat reflecting sheet is not provided, a heating function in a desired direction without excessively thickening as a planar heater It becomes easy to concentrate.

  In addition, the carbon-coated planar heater described above includes an electrode that constitutes a part of the heater circuit while overlapping a predetermined portion at a predetermined position of the conductive sheet, and the electrode is made of a tape-shaped conductive material. If only the portion on the end side of the heater circuit is exposed to the outside and becomes a connection terminal, the heater circuit can be easily formed without impairing the thinness of the planar heater. .

  And after arrange | positioning the prepreg sheet | seat which has a reinforced fiber in uncured thermosetting resin on the inner surface or predetermined plane of one type | mold of a predetermined shape, and arrange | positioning a conductive sheet and an electrode on it, the On the conductive sheet, another prepreg sheet having reinforcing fibers in an uncured thermosetting resin is overlaid, and the upper surface is pressed or / FRP molding of a predetermined shape by sucking the intermediate part and degassing the intermediate part sandwiched between both prepreg sheets while impregnating the thermosetting resin into the conductive sheet and heating at a predetermined temperature for a predetermined time If a body is obtained, it becomes possible to produce a carbon-coated planar heater excellent in mechanical strength, safety and durability at low cost.

  According to the present invention, a conductive sheet made of a conductive carbon material is used to remove air from the middle part sandwiched between the inner and outer resin coat layers by infiltrating a non-conductive resin into a conductive sheet made of a fiber structure. The coated surface heater can be made excellent in safety and durability at low cost.

It is explanatory drawing which shows the procedure of the method of manufacturing the carbon covering planar heater of embodiment in this invention. It is a top view of the carbon covering planar heater created in the procedure of FIG. It is the fragmentary sectional view which expanded along the AA line of FIG. FIG. 3 is an enlarged partial sectional view taken along line B-B in FIG. 2. It is a top view which shows an example at the time of connecting the two carbon covering planar heaters of FIG. 2 to a power supply line collectively. FIG. 6 is an enlarged partial longitudinal sectional view taken along the line CC of FIG. 5. It is a top view which shows an example at the time of connecting one carbon covering planar heater of FIG. 2 to a power wire. FIG. 8 is an enlarged partial longitudinal sectional view for explaining the structure of the connecting portion in FIG. 7. It is the expanded partial longitudinal cross-sectional view for demonstrating the structure of the carbon covering planar heater as an application example which has arrange | positioned the heat | fever reflection sheet below the electroconductive sheet. (A), (B), (C) is a top view which shows the pattern of the sticking system of the electrode with respect to carbon coating paper.

Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. In the present invention, paper is a thin and flat shape made by glueing plant fibers and other fibers, and if it is an elongated fiber having a diameter of 100 μm or less, it can be a mineral, metal, animal-derived substance or synthetic material. Those made using various types of raw materials such as resins are included.

  FIG. 1 is an explanatory view showing a procedure for manufacturing a carbon-coated planar heater according to the present embodiment. In the present embodiment, as a non-conductive sheet-like fiber structure suitable for exerting the chemical characteristics of the conductive carbon material to be coated, a square having a side of about 30 to 40 cm using pulp as a main raw material. The case where two sheets of paper are used and carbon nanotubes are used as the conductive carbon material will be described.

  First, a coating liquid in which carbon nanotubes are uniformly dispersed is uniformly applied to one side of the paper by brush or printing, and dried to prepare carbon-coated paper as a conductive sheet. Next, a tape-like electrode is attached to a predetermined position of the carbon coated paper to form a heater circuit, and then a prepreg sheet (at least having glass fiber reinforced fibers in an uncured thermosetting resin). Place on non-conductive after curing.

  And by laying the same prepreg sheet as above on the carbon coated paper, pressing with a predetermined pressure means, or putting it in a bag sandwiched between two flat plates and pressing it from above and below, While impregnating the carbon-coated paper with the thermosetting resin of the prepreg sheet, discharge unnecessary materials such as air and debris to the outside through the discharge tube, etc., and deaerate the intermediate part sandwiched between the upper and lower prepreg sheets Integrate the whole.

  Finally, the thermosetting resin is cured by heating at a predetermined temperature for a predetermined time to obtain a carbon-coated planar heater that is a single hard board. Depending on the heating conditions, the degassing step by pressing or suction may be performed simultaneously with the heating step or partially at the same time.

  FIG. 2 is a plan view of the carbon-coated planar heater 1A manufactured by the method described above. In the present embodiment, carbon coated paper 2A formed by applying and adhering carbon nanotubes, which are conductive carbon materials having a smaller diameter than the fibers, to the fiber surface of the paper, which is a non-conductive sheet-like fiber constituent, 2A, and generates heat when energized through the electrodes 5a, 5b, 5c. On both the front and back surfaces of the carbon coated paper 2A, 2A, which is a conductive sheet, a resin coat layer 3A made of a nonconductive resin, 3B is formed.

  In the carbon-coated planar heater 1A, the thermosetting resin derived from the prepreg sheet penetrates into the carbon coated papers 2A and 2A, and the intermediate portion sandwiched between the resin coat layers 3A and 3B is deaerated. Since the non-conductive resin on the front and back surfaces and the middle portion is cured, the middle portion having the carbon coated papers 2A and 2B is hermetically sealed without containing air.

  That is, even if the carbon coated paper 2A, 2A based on a pulp paper having a low mechanical strength and weak against water, both front and back surfaces are completely covered with non-conductive resin coating layers 3A, 3B. Excellent waterproof and insulating properties will be demonstrated. Further, since the carbon coated papers 2A and 2A are sealed inside the resin without containing air, they are less likely to be ignited or oxidized, and thus are excellent in safety and durability.

  Further, since the carbon coated papers 2A and 2B made of the fiber structure are hardened in a deaerated state while impregnated with the non-conductive resin of the prepreg sheet to be the resin coat layers 3A and 3B, the carbon coated paper As a result of the paper 2A, 2A being integrated with the front and back non-conductive resins in the same manner as the FRP reinforcing fibers, one FRP molded body is formed as a whole, and even though it is thin, it is extremely excellent in mechanical strength.

  Incidentally, the electrodes 5a, 5b, 5c as energizing means constituting the heater circuit are formed by placing a conductive metal in the form of a thin tape and placing them partially on the carbon coated papers 2A, 2A as shown in the figure. In this state, it is disposed by being attached with a conductive adhesive or the like. One end of the circuit is exposed to the outside to form connection terminals 51 and 52, and this portion constitutes the connection portion 4. In addition, latching holes 30a, 30b, 30c, and 30d are opened at the four corners of the edge where the resin coat layers 3A and 3B extend in the width direction.

  The present embodiment will be described in detail with reference to FIG. 3 which is an enlarged cross-sectional view taken along line AA in FIG. This carbon-coated planar heater 1A is produced in substantially the same process as that for producing an FRP molded body as described above, and its thickness is substantially the same as that of a general FRP molded body. In this figure, the thickness is expressed slightly thicker for the sake of explanation, but the thickness is actually about 1 to 2 mm.

  And on the front and back of the carbon coated paper 2A, resin coated layers 3A and 3A are formed by prepreg sheets in which glass fibers 31 and 32 are arranged in a mesh pattern. It is integrated vertically, and the non-conductive resin is impregnated between the fibers of the carbon coated paper 2A at the intermediate portion of the carbon coated paper 2A, except for the portion where the electrode 5b is pasted. The resin coating layers 3A and 3B made of resin are integrated.

  On the other hand, FIG. 4 shows a cross-sectional view of the connecting portion 4 along line BB in the carbon-coated planar heater 1A of FIG. 2, but the electrode 5b extending in the width direction from above the carbon coated paper 2A is shown in FIG. One surface of the connecting portion 4 is exposed, and this portion serves as a connection terminal 51 for connection to a power supply line. In addition, as a method of forming this connection portion 4, when the second prepreg sheet is stacked, the convex portion of the upper prepreg sheet is shortened by the portion to be exposed at the connection portion 4, and is exposed in the stacked state. The masking tape may be placed on the lower convex portion, heated and cured, and then peeled off.

  The conductive sheet used in the present invention is not limited to the paper using the pulp in the above-described embodiment, and as a non-conductive fiber constituent sheet, it has moderate thinness, durability, and heat resistance. If so, a wide variety of things can be used. For example, cloths and nonwoven fabrics using various fiber materials can be used, and papers and fabrics made of fibers made from inorganic materials such as glass and ore can also be used. Excellent fire resistance. Furthermore, after the conductive carbon material is uniformly dispersed in the liquid in which the fibers are dispersed, the paper may be made and used as it is as a conductive sheet.

  The conductive carbon material used in the present invention is not limited to the carbon nanotube described above, and may be any of carbon black, carbon microfiber (short fiber), and carbon nanohorn. However, from the viewpoint of workability, electrical conductivity, thermal conductivity, and energy efficiency during production, those having a smaller diameter than the coated fibers are preferred, and in addition to this, those having a fiber diameter of at least 8 μm are more preferred, especially carbon. Nanotubes are preferred. Further, as the non-conductive resin constituting the resin coat layers 3A and 3A, it is essential to have heat resistance according to the assumed temperature of the heater, and a phenol resin exhibiting heat resistance of 150 degrees or more is preferable. However, it is not limited to such thermosetting resins, and various resins can be used as long as they can exhibit the prescribed permeability in an uncured state when impregnated into a conductive sheet. can do.

  FIG. 5 shows an example in which two carbon-coated planar heaters 1A of the present embodiment are connected together to a power line. In this example, two carbon-coated planar heaters 1A are electrically connected by a connecting tool 7A having two connecting portions, as shown in FIG. 6 which is an enlarged sectional view taken along the line CC. The connecting portions 4 and 4 are inserted from the left and right insertion ports 7a and 7b, and the elastic surfaces of the spring terminals 7c are pressed against the surfaces of the connection terminals 51 and 52, respectively, to be connected to the power line. Although not shown in the figure, the waterproof portion is covered with a waterproof tape so as to cover the thin portion having the insertion openings 7a and 7b of the connection tool 7A and the exposed portions of the connection portions 4 and 4 together. It is preferable from the viewpoint of preventing leakage.

  FIG. 7 shows an example in which one of the carbon-coated planar heaters 1A is connected to a power supply line, and uses a connection tool 7B having one connection part. In this case, as shown in the enlarged partial longitudinal sectional view of FIG. 8, the connecting portion of the connection tool 7B has the same configuration as the connecting portion 4 of the carbon-coated planar heater 1A, and the connection terminal 51 as shown in the figure. , 71, while superimposing thin portions, the portions are rolled and fixed with waterproof tape or the like.

  FIG. 9 is a partial longitudinal sectional view showing a carbon-coated planar heater 1B as an application example of the above-described carbon-coated planar heater 1A. In this example, the heat reflecting sheet 8 is disposed below the carbon coated paper 2C, which is a conductive sheet, in parallel and not electrically connected to the carbon coated paper 2C through the resin coat layer 3A. And has a resin coat layer 3C below it.

  In other words, the carbon-coated paper itself has a function of radiating a far-infrared ray of a substantially uniform amount in both front and back directions, but when used as a planar heater, there are many cases where it is desired to heat only one side. Therefore, the heat reflecting sheet 8 is arranged for the purpose of concentrating far-infrared radiation on one surface side. In this case, as the heat reflecting sheet 8, an aluminum vapor deposition film, an aluminum foil, or the like is suitable. However, when this is exposed to the outside, the heat reflectivity is deteriorated due to corrosion in a relatively short period of time. It is sealed in FRP to ensure its durability.

  As described above, the carbon-coated planar heater 1B having the directionality to the far infrared rays to be irradiated is suitable for use in a bathroom or a toilet in addition to floor heating and wall heating. Due to its excellent strength and waterproofness, it is also suitable for applications such as placing it in tatami mats, as a snow melting sheet for roofs and passages, or as a heat generating means inside a snow melting block or snow melting tile. Yes. In addition, since it can be produced by the same method and procedure as the FRP molded product, it is possible to provide a normal FRP product with a heater function as it is. The use is extremely diverse, such as adding a heat retaining function to the wall of the bathtub as a partial heater.

  When the heat reflecting sheet 8 is directly arranged on the lower surface of the carbon coated paper 2A, this is likely to cause an electrical short circuit, and the carbon coated paper 2A is impregnated with a non-conductive resin and coated with a resin. Since there is a concern that the integration with the layer is likely to be impaired, the arrangement is such that one prepreg sheet is interposed. In addition, when the adhesiveness between the heat reflecting sheet 8 and the resin coat layers 3A and 3B is low and the connecting force between the respective layers may be reduced to cause a decrease in mechanical strength, the heat reflecting sheet 8 may have a plurality of small sizes. By forming the holes uniformly, the connection force can be increased.

  Furthermore, although not shown in the drawings, as a modification of the above-described carbon-coated planar heater 1B, a sheet-like solar cell may be used in place of the heat reflecting sheet 8, thereby providing a planar heater that also serves as a solar panel. it can. In this case, a resin coating layer having a high translucency is used, and a carbon-coated paper having a predetermined translucency in a state where the resin is impregnated may be used. For example, it can be used as a snow melting means during snowfall in winter while using it as a solar power generation means in normal times by using this instead of the board or sheet constituting the top part of the roof of the carport or the greenhouse. It becomes possible.

  In addition, about the sticking of the electrode to the carbon coated paper 2A in the above-mentioned embodiment, as shown in FIG. Although the case where it provided was demonstrated, as shown to FIG. 10 (B), electrodes 5f and 5g are stuck only to the corner | angular part of the diagonal position in the square carbon application paper 2A, or as shown to FIG. 10 (C). A strip-shaped electrode 5h, 5i may be affixed to both short sides of an elongated strip-like carbon coated paper 2D, thereby reducing the resistance value and easily preventing electrode deterioration. It becomes. In addition, the coating liquid may be applied not only on one side of the paper but also on both sides, whereby a carbon coated paper with further excellent conductivity can be obtained. Furthermore, in FIG. 2, FIG. 5, and FIG. 7, since the resin coat layers 3A and 3B are almost transparent, the inside is seen through from the outside.

  As described above, a carbon-coated planar heater using a conductive carbon material can be made excellent in safety and durability at a low cost by the present invention.

  1A, 1B carbon coated sheet heater, 2A, 2C, 2D carbon coated paper, 3A, 3B, 3C resin coating layer, 4 connection part, 5a, 5b, 5c, 5d, 5e, 5f, 5g, 5h, 5i electrode, 7A, 7B connector, 8 heat reflecting sheet, 31, 32 glass fiber, 51, 52, 71 connection terminal

Claims (3)

A carbon-coated planar heater that includes a conductive sheet formed by attaching a conductive carbon material having a diameter smaller than that of the fiber to the fiber surface of the sheet-like fiber structure, and generates heat by energizing the conductive sheet. A resin coat layer made of a non-conductive resin is formed on both the front and back surfaces of the conductive sheet, and the intermediate portion sandwiched between the resin coat layers is deaerated by the non-conductive resin penetrating into the conductive sheet With the non-conductive resin of the front and back and the intermediate part cured, the intermediate part having the conductive sheet is sealed in a state that does not contain air, and it is said to have internal and external waterproofness and internal and external insulation, The front and back resin coat layers are made of a fiber reinforced resin obtained by curing a prepreg sheet having reinforcing fibers in an uncured thermosetting resin, and the intermediate portion is impregnated before the conductive sheet is impregnated. Thermosetting resin has been integrated with the fiber-reinforced resin of the front and back by a heat cured, carbon-coated planar heater characterized in that it constitutes one of the FRP molded body as a whole. On one surface side of the conductive sheet, a heat reflecting sheet that reflects far-infrared rays is disposed in parallel and not electrically connected to the conductive sheet, and the outer surface side is disposed on the resin coating layer. 2. The carbon-coated surface according to claim 1, wherein the carbon-coated surface is covered with an FRP molded body and reflects far-infrared rays toward a side on which the heat reflecting sheet is not disposed. Heater. The carbon-coated planar heater according to claim 2, wherein a plurality of small holes for increasing the connecting force between the layers are uniformly formed in the heat reflecting sheet.