JP3454609B2 - Sealed surface heating element - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sheet heating element having a heating resistor made of sheet-shaped plastic or rubber-like elastic material mixed with conductive fine particles, which is a laminated sheet of a plastic film and an aluminum foil. The present invention relates to a hermetically sealed planar heating element formed by hermetically coating.

[0002]

2. Description of the Related Art The above-mentioned sheet heating element is widely used not only for a heating device to be embedded in a floor or a wall of a building, but also for freezing various facilities and buildings in cold regions or for melting snow. This sheet heating element has a structure in which sheet heating resistors made of sheet plastic or rubber mixed with conductive fine particles are formed, and electrode wires for energization are embedded on both sides of the sheet heating resistor. It can be easily and freely adjusted depending on the type and mixing amount of fine particles, for example, 40 ° C to
It can be set to a desired temperature of about 60 ° C. and is excellent in safety and economy (including energy saving).

Although the above-mentioned sheet heating element can be applied as it is, the sealing property, the durability, the weather resistance, the chemical resistance and the like are improved, and the surface thermal diffusivity (uniform temperature distribution) is improved. From the standpoint of preventing the permeation of gas or permeation of gas, the planar heating element is used as a hermetically sealed planar heating element by hermetically covering with a laminate sheet of a plastic film and an aluminum foil.

[0004]

However, in the conventional example of this type of hermetically sealed sheet-like heating element, the above-mentioned laminate sheet is a laminate of a plastic film and an aluminum foil up to the edge of the entire circumference. Since the sheet heating element was sandwiched between the upper and lower laminate sheets and the two laminate sheets were heated and melted at the edges to be sealed, they were embedded in a mortar like a floor heater, for example. When used, the liquid such as mortar (which shows high alkalinity) comes into contact with the edge of the aluminum foil, so that the aluminum foil is melted and the aluminum surface coating member and the insulating member are partially peeled off. There is an inconvenient aspect that the hermeticity is deteriorated.

The present invention has been made in view of the above technical problems, and an object of the present invention is to seal and cover a planar heating element with a laminate sheet in which a plastic film and an aluminum foil are joined. By reducing or preventing the peeling of the aluminum foil at the hermetically sealed portion at the peripheral edge of the above, it is possible to provide a hermetically sealed planar heating element having excellent hermeticity, durability and chemical resistance.

[0006]

DISCLOSURE OF THE INVENTION According to the present invention, a surface is formed of a plastic or rubber-like elastic material mixed with conductive fine particles, and conductive electrodes are embedded on both sides of the surface. In a hermetically sealed planar heating element, which is formed by hermetically covering a flat heating element with a laminated sheet in which a plastic film and an aluminum foil are joined together, only a plastic film layer of a predetermined width is provided on the peripheral portions of two front and back laminated sheets. A region is provided, and the upper and lower laminate sheets are heat-welded and sealed in the region of only the layer of the plastic film, or the region of the layer of the plastic film and the joint portion of the aluminum foil and the plastic film are provided. The above object is achieved by adopting a constitution in which the upper and lower laminated sheets are heat-welded in the straddling range.

[0007]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a first example of a sealed sheet heating element to which the present invention is applied.
2 is a perspective view of an embodiment, FIG. 2 is a perspective view of the sheet heating element in FIG. 1, and FIG. 3 is a hermetically sealed sheet heating element of FIG. It is a partial perspective view which shows a joining part. 1 to 3, the sheet heating element 10 includes conductive electrode particles 12 and 12 embedded on both sides of a sheet-like portion 11 which is a strip-shaped molded product of a plastic or rubber-like elastic material mixed with conductive fine particles. It has a structure. The planar portion 11 forms a heating resistor, and a voltage is applied between the electrode wires 12 on both sides of the planar portion 1.
1 is energized to raise the temperature of the planar portion 11 to, for example, about 40 ° C. to 60 ° C.

The sheet heating element 10 is sandwiched between upper and lower (front and back) laminating sheets 13 and 13, and the peripheral edges of the laminating sheets 13 and 13 are heat-welded to each other to thereby form the laminating sheets 13 and 13. Is sealed inside a sealed bag body formed by. The laminate sheet 13 has a structure in which a plastic film 14 and an aluminum foil 15 are joined together.

In the case of the laminate sheet 13 shown in the figure, as shown in FIG. 3, a plastic protective film 16 covering the entire area of the laminate sheet 13 is further formed on the surface of the aluminum foil 15. Further, the aluminum foil 15 enhances the sealing function of the planar heating element 10 by blocking the permeation of not only liquid but also gas, and quickly spreads the heat generated by the planar heating element 10 to spread the entire surface area. This is for equalizing the temperature distribution.

The reason why the sheet heating element 10 is covered with the laminate sheet 13 having such a layer of the aluminum foil 15 and hermetically sealed is that the gas is completely cut off and the durability of the sheet heating element 10 is improved. The reason is that the heat generated from the sheet heating element 10 is quickly diffused to make the temperature distribution on the surface of the sheet heating element 10 uniform.

Therefore, according to the present embodiment, FIGS.
As shown in FIG.
In each of these, the peripheral region is provided with a region B of only a layer of the plastic film 14 having a predetermined width, and the upper and lower laminating sheets 13 at a portion of the predetermined width S within the region B of the layer of the plastic film 14 only, By heat-welding 13 it is sealed all around. In a specific example, the plastic film 14 has a thickness of about 1 mm.
The width dimension of the region B of only the layer is about 15 mm, and the width dimension of the heat-welded portion S is about 10 mm.

In the embodiment of FIG. 1, the sealing structure as shown in FIG. 3 is formed over the entire circumference of the sheet heating element 10 (all four sides in the illustrated example). In FIG. 1, the electrode wires 12 and 12 of the sheet heating element 10 are connected to the internal connecting portions 21 and 21.
Connected to the power supply wires 18, 18 with these power supply wires 1
8 and 19 are taken out to the outside by a suitable sealed take-out unit 19 and 19.

FIG. 4 is a partial perspective view corresponding to FIG. 3, showing a peripheral edge sealed joint of another embodiment of the hermetically sealed sheet heating element to which the present invention is applied. In this embodiment, in each of the two front and back laminated sheets 13, 13, an area D of only a layer of the plastic film 14 having a predetermined width is provided at the peripheral edge thereof, and the upper and lower laminated sheets 13, 13 are heat-welded together. The sealing area W is set in a range that extends over the area D of only the layer of the plastic film and the joint portion of the aluminum foil 15 and the plastic film 14. The sealing region W may include the entire region D of only the layer of the plastic film 14, or may be a range including a part of the region D except the edge side portion.

The present embodiment is different from the embodiment of FIG. 3 in the points described above, but is substantially the same in other points, and the sealing structure as shown in FIG. It is formed all around. Further, in one embodiment, when the thickness of the plastic film 14 is about 1 mm, the width dimension of the region D of only the layer of the plastic film 14 is about 10 mm to about 15 mm, and the width dimension of the heat welding portion W. The positions and the positions were selected in the range of about 5 mm to about 10 mm on both sides of the edge of the aluminum foil 15 as the center.

FIG. 5 is a partial perspective view showing still another embodiment of the hermetically sealed sheet heating element to which the present invention is applied, and FIG. 6 is a partial sectional view taken along line 6-6 in FIG. . In this embodiment, the peripheral edges on both sides of the planar heating element 10 in the lengthwise direction (the direction parallel to the electrode wire 12) are hermetically fixed with the same structure as the peripheral edge heat-welding portions described with reference to FIGS. However, a sealing structure as shown in FIG. 6 is adopted at the peripheral portions along the front and rear end edges in the direction substantially perpendicular to the electrode wire 12.

In FIGS. 5 and 6, the laminated sheet 13 used in this embodiment is used by winding a long endless (endless) material in a roll and cutting it into predetermined lengths. is there. Therefore, the region B (FIG. 3) or the region D (FIG. 4), which is only a layer of the plastic film 14 having a predetermined width, is provided on both side peripheral portions in the length direction (direction parallel to the electrode wire 12) of the laminate sheet 13. The two side portions are hermetically fixed by the same structure as the peripheral edge heat-welding portion shown in FIG. 3 or 4.

On the other hand, at the peripheral edge along the front and rear edges (the front and rear edges in the direction substantially perpendicular to the electrode wire 12) of the laminate sheet 13, since the sheet is a roll material, the aluminum foil 15 is cut at the cut portion. The edge and the edge of the plastic film 14 are both joined to the edge of the sheet.
Therefore, at the front and rear edges of the laminate sheet 13, the aluminum foil 15 may come into contact with external gas or liquid.
It is desired to further seal the front and rear edges.

The embodiment shown in FIGS. 5 and 6 is implemented from such a point of view, and the sealing structure shown in FIG. 3 or FIG. At the edge portion, another plastic film patch member 20 is bent as shown in the figure to be closely attached to the outer surface of the entire area of the front and rear edge portions, and the upper and lower outer surfaces (outer surface and outer surface) to the upper and lower (front and back) laminated sheets 13 , 13 together with a heat-welded contact structure.

When the roll-shaped laminated sheet 13 is cut into a predetermined length to form the above-mentioned hermetically sealed planar heating element, the hermetically sealed structure shown in FIG. 3 or 4 is provided on both sides in the longitudinal direction. The upper and lower laminated sheets 1 at the front and rear edges
When heating and welding 3, 3 and 13, sufficient durability may be ensured even if the aluminum foil 15 and the plastic film 14 are hermetically fixed in a state in which the respective edges are overlapped. In such a case, in the embodiment of FIGS. 5 and 6, the patch member 20 may be omitted and the front and rear edge portions may be heat-welded, and the present invention also includes such an embodiment within its scope. It includes.

The laminate sheet 13 may be a laminate of at least one layer of plastic film and at least one layer of aluminum foil, and may have a structure having two or more layers of plastic film and aluminum foil.

According to the embodiment described above, the planar portion 11 is formed of a plastic or rubber-like elastic material mixed with conductive fine particles, and the electrode wires 12, 12 for energization are formed on both sides of the planar portion. In a sealed type sheet heating element formed by sealingly embedding the sheet heating element 10 with a laminate sheet 13 in which a plastic film 14 and an aluminum foil 15 are bonded to each other, the sealing sheet sheet heating element 10 is provided on the peripheral portions of the two front and back laminate sheets 13. An area of only a layer of the plastic film 14 having a predetermined width is provided, and the upper and lower laminate sheets 13 are heat-welded and sealed to each other in the area of the layer of the plastic film 14 alone, or only the layer of the plastic film 14 is formed. The upper and lower laminating sheets 13 are mutually attached to each other in a range straddling a region and the joint portion of the aluminum foil 15 and the plastic film 14. Since it is configured to be heat-welded, it is possible to reduce or prevent erosion of external gas or liquid on the joint surface of the aluminum foil, and peel off the aluminum foil 15 at the hermetically sealed joint portion of the peripheral edge portion of the laminate sheet 13. By preventing it, a hermetically sealed sheet heating element that can improve hermeticity, durability and chemical resistance is provided.

[0022]

As is apparent from the above description, according to the first aspect of the present invention, the planar portion is formed of the plastic or rubber-like elastic material mixed with the conductive fine particles, and both sides of the planar portion are formed. A sealing type planar heating element in which a sheet heating element having an energizing electrode wire embedded therein is hermetically covered with a laminate sheet in which a plastic film and an aluminum foil are joined. The area of only the layer of the plastic film of a predetermined width is provided in
Since the upper and lower laminated sheets are heat-welded in the region of only the layer of the plastic film, when the sheet heating element is hermetically covered by the laminated sheet in which the plastic film and the aluminum foil are joined, the peripheral portion of the laminated sheet is It is possible to reduce or prevent the peeling of the aluminum foil at the hermetically sealed joint, and to provide a hermetically sealed planar heating element having excellent hermeticity, durability and chemical resistance.

According to the second aspect of the present invention, a surface portion is formed of a plastic or rubber-like elastic material mixed with conductive fine particles, and a surface is formed by energizing electrode wires on both sides of the surface portion. In a hermetically sealed planar heating element, which is formed by hermetically covering a flat heating element with a laminated sheet in which a plastic film and an aluminum foil are joined together, only a plastic film layer of a predetermined width is provided on the peripheral portions of two front and back laminated sheets. Since a region is provided and the upper and lower laminate sheets are heat-welded in a range that extends over the region of only the layer of the plastic film and the joint portion of the aluminum foil and the plastic film, a laminate in which the plastic film and the aluminum foil are joined When the sheet-like heat generating element is hermetically covered with a sheet, an aluminum foil at a hermetically sealed portion of the peripheral edge of the laminate sheet Peeling can be reduced or prevented, sealed planar heating element having excellent durability and chemical resistance is provided.

[Brief description of drawings]

FIG. 1 is a schematic perspective view of an embodiment of a hermetically sealed planar heating element to which the present invention is applied.

FIG. 2 is a partial perspective view schematically showing the structure of the planar heating element in FIG.

3 is a partial perspective view showing an example of a sectional structure of a hermetically sealed welded portion taken along line 2-2 in FIG. 1. FIG.

FIG. 4 is a partial perspective view showing another example of the sectional structure of the hermetically sealed welded portion along the line 2-2 in FIG.

FIG. 5 is a partial perspective view showing another embodiment of the hermetically sealed sheet heating element to which the present invention is applied.

6 is a partial cross-sectional view taken along the line 6-6 in FIG.

[Explanation of symbols]

10 Sheet heating element 11 Plane 12 electrode wires 13 Laminated sheet 14 plastic film 15 Aluminum foil 20 patch members

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Claims (2)

(57) [Claims] 1. A plastic film comprising a planar heating element comprising a planar portion formed of plastic or rubber-like elastic material mixed with conductive fine particles, and electrode wires for energization embedded on both sides of the planar portion. In a hermetically sealed planar heating element, which is formed by hermetically covering with a laminate sheet in which an aluminum foil and an aluminum foil are joined, a region of only a plastic film layer having a predetermined width is provided at the peripheral edge of two laminate sheets on the front and back sides. A hermetically sealed sheet heating element, wherein the upper and lower laminate sheets are heat-welded in the area of only the layer. 2. A planar heating element comprising a plastic or rubber-like elastic material mixed with conductive fine particles to form a planar portion and burying electrode wires for energization on both sides of the planar portion. In a hermetically sealed planar heating element, which is formed by hermetically covering with a laminate sheet in which an aluminum foil and an aluminum foil are joined, a region of only a plastic film layer having a predetermined width is provided at the peripheral edge of two laminate sheets on the front and back sides. A heat-welded upper and lower laminate sheets in a range that straddles the region of only the layer and the joint of the aluminum foil and the plastic film.