JP2007165282A - Planar heating element and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a planar heating element allowing various kinds of dimension design, and particularly excelling in flexibility; and to provide its manufacturing method, in relation to a planar heating element formed by sewing electrode wires into cloth having conductivity. <P>SOLUTION: This planar heating element 10 is characterized in that at least two electrodes 12a and 12b each formed with a metal wire are separately sewed into at least two conductive sheet pieces 11a and 11b each formed by supporting a resin containing conductive powder to cloth; partial parts 121a and 121b of the electrodes are extended from the sheet pieces 11a and 11b; the sheet pieces 11a and 11b are connected to each other through the extended parts 121a and 121b of the electrodes; and the sheet pieces 11a and 11b and the electrodes 12a and 12b are sandwiched between insulating films 13a and 13b. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a planar heating element in which electrode wires are sewn into a conductive cloth, and more particularly to a planar heating element excellent in flexibility and a method for manufacturing the same.

  As a planar heating element in which electrode wires are sewn into a conductive cloth, there is a planar heating element described in Patent Document 1, for example. This sheet heating element wovens a composite yarn composed of a single metal fiber yarn and a fabric single thread as warp or weft yarns at both ends of a woven fabric serving as a sheet heating element, and is electrically conductive on the entire surface of the cloth. A sheet heating element coated with a conductive paint, embedded under the road surface to prevent snow melting or freezing, and used as a heating element for heating and bedding in the home and for floor and attic heating in buildings Used as. However, in this planar heating element, since the electrodes are woven into the woven fabric as warp or weft, it is difficult to obtain planar heating elements of various dimensions, or the electrode part becomes thick and is flexible. There was a problem of being inferior.

  Further, as a planar heating element obtained by improving the planar heating element, there is a planar heating element described in Patent Document 2, for example. This sheet heating element is a sheet heating element in which a plurality of metal fibers are sewn at both ends of a sheet impregnated with a conductive resin agent such as carbon in a cloth, and electrodes having various dimensions. It is possible to obtain a heating element. Moreover, the thickness of the sheet impregnated with the conductive resin agent is the same thickness at the center portion of the cloth and both end portions of the electrode portion, and can be curved. However, this planar heating element contains a large amount of conductive resin agent such as carbon in the cloth, so that it becomes hard and is flexible when it is used repeatedly for bending or bending, for example, for use with clothing. There was a problem of being inferior.

Japanese Utility Model Publication No. 03-84584 JP-A-11-214131

  The present invention solves the above problems and relates to a planar heating element in which electrode wires are sewn into a conductive cloth, and various dimensional designs are possible. In particular, the planar heating element having excellent flexibility and its It is an object to provide a manufacturing method.

  Means for solving the problems of the present invention include, as illustrated in FIGS. 1A and 1B, at least two conductive sheet pieces 11a in which a resin containing conductive powder is supported on a fabric. 11b, at least two electrodes 12a, 12b made of metal wires are sewn apart from each other, and part of the electrodes 121a, 121b extend from the sheet pieces 11a, 11b, The sheet pieces 11a and 11b are connected via the extended portions 121a and 121b, and the sheet pieces 11a and 11b and the electrodes 12a and 12b are sandwiched between insulating films 13a and 13b. It is the planar heating element 10 characterized.

  The means for solving the problem of the present invention is, as illustrated in FIGS. 1A and 1B, at least two conductive sheet pieces 11a carrying a resin containing conductive powder on a fabric. 11b are placed on the support sheet 15 at intervals, and then at least two electrodes 12a and 12b made of metal wires are separated from each other and sewn to the sheet pieces 11a and 11b and the support sheet 15. Then, the sheet heating element 10 is manufactured by sandwiching the sheet pieces 11a and 11b, the electrodes 12a and 12b, and the support sheet 15 with insulating films 13a and 13b.

  According to the present invention, a sheet heating element in which electrode wires are sewn into a conductive cloth can be designed in various dimensions, and in particular, a sheet heating element excellent in flexibility and a method for manufacturing the sheet heating element can be provided. It has become possible.

  As illustrated in FIGS. 1A and 1B, the planar heating element of the present invention has at least two conductive sheet pieces 11a and 11b formed by carrying a resin containing conductive powder on a fabric. The at least two electrodes 12a and 12b made of metal wires are sewn apart. The fabric is not particularly limited as long as it is a fabric having a structure that can contain a resin containing a conductive powder. Examples of the fabric having such a structure include woven fabrics, knitted fabrics, and nonwoven fabrics. If it is a nonwoven fabric, many voids between fibers can be secured and it is rich in porosity, which is preferable. As a kind of the nonwoven fabric, a short fiber nonwoven fabric by a dry method, a long fiber nonwoven fabric by a spunbond method, a wet method nonwoven fabric and the like can be applied. The short fiber nonwoven fabric by the dry method has an average fiber length of preferably 10 to 100 mm, more preferably 20 to 80 mm, and a fiber called a normal staple fiber having 5 to 30 crimps / inch is used as a card machine or an air array device. Can be obtained by forming into a fiber web. In addition, the method of bonding the constituent fibers of the nonwoven fabric is not particularly limited, for example, a method of bonding fibers by impregnating an adhesive, a method of tangling fibers by needle punching or water entanglement, and the like For example, a method of thermally bonding fibers together by heat treatment after mixing the conductive fibers can be applied.

  The fineness of the constituent fibers contained in the nonwoven fabric is not particularly limited, and the average fineness is preferably 0.05 to 50 dtex. Moreover, in order to make a structure rich in flexibility, the average fineness is preferably 0.1 to 10 dtex. In addition, in order to obtain a non-woven fabric of constituent fibers having a small average fineness such as an average fineness of 0.1 to 0.5 dtex, for example, using a splittable conjugate fiber having two or more fiber-forming resin components, A method of dividing the fiber at the same time as the hydroentanglement can be applied.

Moreover, 20-300 g / m < ² > is preferable, as for the surface density of the said fabric, 30-250 g / m < ² > is more preferable, and 40-200 g / m < ² > is still more preferable. If it is less than 20 g / m ² , the amount of the resin containing conductive powder may be reduced, and heat generation may be reduced. If it exceeds 300 g / m ² , it may take too much time to sew the electrode. , Flexibility may be reduced. The thickness of the fabric is not particularly limited as long as it is possible to sew an electrode made of a metal wire, and is preferably 0.03 to 2 mm, more preferably 0.05 to 1.5 mm, 0.1-1.0 mm is still more preferable. If the thickness is less than 0.03 mm, the amount of the resin containing the conductive powder is reduced, and the heat build-up may be reduced. If the thickness exceeds 2 mm, it takes too much time to sew the electrode, and the flexibility is low. May decrease. The thickness is the thickness specified in the 6.1.2A method of JIS L1913-1998. However, the load is 2.0 kPa.

  In the present invention, a resin containing conductive powder is supported on the fabric. The conductive powder is not particularly limited as long as it is conductive powder, and for example, carbon or graphite powder can be preferably applied. The carbon or graphite used for the conductive powder is preferably spherical, shell-like, scale-like, needle-like, or fiber-like particles having an average particle size of 0.5 to 500 μm.

  The resin containing conductive powder can also contain rubber such as natural rubber and synthetic rubber, and as the resin, a synthetic resin such as a thermoplastic resin and a thermosetting resin can be applied. Polyacrylic resins, polyester resins, epoxy resins, polyamide resins, polyimide resins, polyolefin resins, polyether / etherketone resins, polyphenylene sulfide resins, silicone resins, and the like can be applied. Moreover, as a compounding quantity of the electroconductive powder with respect to the said resin, 20-1000 mass parts is preferable with respect to 100 mass parts of resin, for example, 30-800 mass parts is more preferable, 50-500 mass parts is still more preferable.

  In order to obtain a conductive sheet piece carrying a resin containing a conductive powder on the fabric, specifically, for example, the resin in the form of a powder or an emulsion-type dispersion and the conductive powder Is dispersed in a solvent such as water, a thickener, a surfactant or the like is added to increase the viscosity of the mixture into a paste form, and the fabric is impregnated or applied by coating. As a conductive sheet, the sheet can be cut into a predetermined size to form conductive sheet pieces 11a and 11b. Further, for example, as illustrated in FIGS. 4A and 4B, the powdery resin or emulsion-type dispersion and the conductive powder are dispersed in water to increase the thickener and the surfactant. And the like, and the compounded liquid that has been thickened to form a paste is partially impregnated in a predetermined position of the fabric 14 or is applied by coating or the like, so that it is partially formed in the fabric 14 It can also be set as the electrically conductive sheet pieces 11a and 11b.

  Moreover, as an adhesion amount of the said resin containing the electroconductive powder with respect to the said fabric, 50-400 mass parts is preferable with respect to 100 mass parts of fabrics, 70-300 mass parts is more preferable, 90-250 mass parts is still more preferable. .

  The shape of the sheet piece is not particularly limited, and for example, a rectangular shape and other polygonal shapes can be applied as illustrated in FIG. 1A, but a rectangular shape is preferable in terms of heat generation efficiency. Moreover, although the dimension and area are not specifically limited, In the case of a rectangle, it is preferable that one side is 2-35 cm, it is more preferable that it is 3-25 cm, and it is still more preferable that it is 4-15 cm. If the side is less than 2 cm, the flexibility may be rather inferior, and if it exceeds 35 cm, the voltage between the electrodes becomes too high, which may be inconvenient for use such as clothing or portable use. In addition, when the shape of the sheet piece is rectangular, it is preferable that the adjacent sides of the two adjacent sheet pieces are substantially parallel to each other in consideration of the ease of sewing of the electrodes.

  Further, the arrangement of the sheet pieces is not particularly limited. For example, in FIG. 1A, four rectangular conductive sheet pieces have 11a and 11b arranged vertically, and 11c and 11d are arranged next to them. They are arranged vertically and are arranged so that the sides of each sheet piece are parallel to each other, and the two electrodes 12a and 12b are connected to four sheet pieces. Further, for example, in FIG. 3A, three rectangular conductive sheet pieces 11a and 11b are arranged vertically, 11e is arranged beside them, and the sides of the sheet pieces are parallel to each other. The two electrodes 12a and 12b are connected to three sheet pieces. In the present invention, the arrangement of the sheet pieces is not particularly limited, and it is possible that the sides of the sheet pieces are not parallel to each other. Are preferably arranged so as to be parallel to each other.

  Further, in the present invention, the arrangement of electrode stitching is not particularly limited. For example, in FIG. 1 (a), the electrode 12a is connected in the order of the sheet pieces 11a, 11b, 11c, and 11d, and the electrode 12b corresponding to the electrode 12b. Are connected in the order of sheet pieces 11a, 11b, 11c, and 11d. For example, in FIG. 3A, the electrode 12a is connected in the order of the sheet pieces 11a, 11b, and 11e, and the corresponding electrode 12b is connected in the order of the sheet pieces 11a, 11e, and 11b. As described above, in FIG. 3A, the adjacent sheet pieces 11a and 11b are connected via the extending portion 121a of the electrode 12a, and the adjacent sheet pieces 11a and 11b are connected to the electrode 12b. It connects via the sheet piece 11e while passing through the extension part 121b.

  Further, in the present invention, as illustrated in FIG. 1A, the distance between the sheet pieces 11a and 11b is not particularly limited, and the distance between the sheet pieces in the adjacent row, for example, the sheet pieces 11a and 11d, The interval is not particularly limited. In consideration of the case where the adjacent sheet pieces 11a and 11d are polygonal and the adjacent sides are not parallel, in the present invention, the interval between the adjacent sheet pieces is determined as follows. That is, in the adjacent side of the adjacent sheet piece, a perpendicular is drawn from the vertex included in the side of one sheet piece to the side of the other sheet piece, and the minimum length of the legs is adjacent. Determined as the distance between sheet pieces. For example, as illustrated in FIG. 5, in the adjacent sheet pieces 11 a and 11 b, the sheet piece 11 a is a triangle formed by vertices A, B, and C, and the sheet piece 11 b is formed by vertices D, E, F, and G. In the case of a quadrangular shape, a perpendicular line is drawn from the vertex E to the side AB and the length of the foot is d1, similarly, a perpendicular line is drawn from the vertex D to the side AB and the length of the foot is d2, and similarly the side from the vertex A to the side A perpendicular is drawn to DE and the length of the foot is set to d3. The minimum length is set to d1 as the distance between the adjacent sheet pieces 11a and 11b.

  In the present invention, according to the above definition, the interval between adjacent sheet pieces is preferably 2 to 100 mm, more preferably 5 to 75 mm, and still more preferably 10 to 50 mm. If it is less than 2 mm, the flexibility may be inferior or the electrode may be easily deteriorated. If it exceeds 100 mm, it takes time to sew the electrode, or a sufficient amount of heat can be applied to the object. It may disappear.

  Further, in the present invention, as described above, it is preferable that the sides of the sheet pieces are arranged so as to be parallel to each other, but in such a case, as illustrated in FIG. When the length of the electrode 12a or 12b sewn into the sheet piece 11a is L1, and the length of the electrode 121a of the extending part from the sheet piece 11a is L2, L1 is 2 to 100 of L2. It is preferably doubled, more preferably 3 to 50 times, and even more preferably 4 to 20 times. If L1 is less than twice L2, it may take time to sew the electrode, or it may not be possible to apply a sufficient amount of heat to the object. If it exceeds 100 times, the flexibility is poor. Or the electrode is likely to deteriorate. As illustrated in FIG. 1A, the magnification between L1 and L2 is between the sheet pieces 11a and 11b adjacent to each other in the extending direction of the electrodes, or between the sheet pieces 11c and 11d. The lengths of the electrodes 122a and 122b in the extending portion between the sheet piece 11b in the left row and the sheet piece 11c in the right row are as described above between L1 and L2. Magnification shall not be applied.

  In the present invention, the electrodes 12a and 12b are composed of metal wires, and a metal wire in which thin conductive metal strands are bundled or a twisted wire obtained by twisting metal strands is used. The conductive sheet pieces 11a and 11b are sewn separately so as to penetrate the front and back sides. In addition to the metal wires, it is also possible to use stranded wires combined with organic fibers such as synthetic fibers, semi-synthetic fibers, and natural fibers. Further, the number of the metal wires is not particularly limited, and may be one as illustrated in FIG. 1 or may be plural as illustrated in FIG. In the case of one, it is suitable for applications where the heat generation temperature is relatively low, and is also suitable for a relatively small sheet piece. Further, the manufacturing process is simplified and the cost can be kept low. There is. Moreover, when there are a plurality of sheets, it is suitable for an application having a relatively high heat generation temperature, and also suitable for a relatively large sheet piece.

  As the conductive wire, for example, a wire drawn from a metal material having a low electrical resistance such as copper, silver, aluminum, tin, the same electrical resistance such as copper, silver, aluminum, tin on the surface of synthetic fiber or natural fiber An element wire plated with a small metal material can be applied. The wire diameter of the conductive element wire is preferably 0.01 to 0.5 mm, and more preferably 0.03 to 0.3 mm. The number of conductive wires constituting the stranded wire is preferably 2 to 100, more preferably 2 to 25. The interval between the seams is preferably 1 to 10 mm, and can be sewn with an industrial sewing machine or the like.

  In the present invention, as illustrated in FIGS. 1A and 1B, at least two electrodes 12a and 12b are sewn into at least two conductive sheet pieces 11a and 11b at a distance from each other. . The degree of separation depends on the dimensions of the conductive sheet pieces 11a and 11b. Specifically, the distance between the center lines of the electrodes 12a and 12b is preferably 1 to 30 cm, and preferably 2 to 20 cm. Preferably, 2-10 cm is more preferable. If it is less than 1 cm, the number of electrodes becomes too large and the flexibility may be rather poor. On the other hand, if it exceeds 30 cm, the voltage between the electrodes becomes too high, which may be inconvenient for clothing or portable use. .

  In the present invention, as illustrated in FIGS. 1A and 1B, the electrode portions 121 a and 121 b extend from the sheet pieces 11 a and 11 b, and the electrode extension portions 121 a and 121 b are The sheet pieces 11a and 11b are connected to each other. In order to obtain such extended portions 121a and 121b, there is a method in which the two electrodes 12a and 12b are sewn apart with the conductive sheet pieces 11a and 11b spaced apart. However, in this method, it may take time and effort to equalize the length of the electrode extension 121a and the length of 121b. Therefore, as illustrated in FIGS. 1A and 1B, at least two conductive sheet pieces 11a and 11b are placed on the support sheet 15 at intervals, and as necessary. Fixing on the support sheet 15 with a double-sided adhesive tape 16 or the like, and then separating the two electrodes 12a and 12b from each other and sewing them into the sheet pieces 11a and 11b and the support sheet 15, thereby improving work efficiency. Can be improved.

The support sheet 15 is not particularly limited as long as it is relatively thin and can support the sheet piece. For example, a woven fabric, a knitted fabric, a nonwoven fabric, a film, or the like can be applied. In particular, a nonwoven fabric is preferable as the support sheet 15 because the fiber structure is dense and the surface density can be lowered. More specifically, preferred areal density is 5 to 100 g / ^{m 2,} more preferably 10~70g / ^{m 2,} more preferably 15 to 60 g / ^{m 2.} Moreover, the nonwoven fabric etc. which heat-fused the fiber web containing a heat-fusible fiber component using a pair of heating rolls can be used suitably.

  Further, as another method for obtaining the electrode extended portions 121a and 121b with high work efficiency, as illustrated in FIGS. 4A and 4B, partially conductive sheet pieces 11a, 11b is formed, and then the two electrodes 12a and 12b are separated from each other and sewn into the sheet pieces 11a and 11b and the fabric 14, and this method can also improve the working efficiency. it can. In this case, by using a stretchable nonwoven fabric in which crimps are expressed using latent crimpable fibers as the fabric 14, a planar heating element having excellent flexibility can be obtained.

  In the present invention, as illustrated in FIGS. 1A and 1B, the sheet pieces 11a and 11b and the electrodes 12a and 12b are sandwiched between electrically insulating films 13a and 13b. The insulating film is not particularly limited as long as it can be laminated, for example, and is preferably a film made of a thermoplastic resin. For example, polyester resins such as polyethylene terephthalate and polybutylene terephthalate, nylon 6, and nylon 66 Examples thereof include polyamide resins such as polypropylene, polyolefin resins such as polypropylene and polyethylene, acrylic resins such as polyacrylonitrile, and polyvinyl alcohol resins such as polyvinyl acetate and polyethylene vinyl acetate copolymer. It is also possible to apply a laminated film made of a combination of these resins, or a composite film made of a laminated film made of these resins and other materials such as woven or knitted fabric and nonwoven fabric. For example, polyethylene terephthalate resin and polyethylene A laminated film composed of a combination with a vinyl acetate copolymer resin can be exemplified. Moreover, when especially electrical insulation and heat resistance are required, films, such as a fluorine resin and a silicon resin, can be mentioned, for example.

  The thickness of the film is not particularly limited, and may be appropriately selected according to the material of the film and the required flexibility. For example, the thickness is preferably 10 to 150 μm, more preferably 15 to 100 μm, and still more preferably 20 to 70 μm. If it is less than 10 μm, it may deteriorate due to repeated bending, and if it exceeds 150 μm, it may be inferior in flexibility.

  In the present invention, the sheet pieces 11a and 11b and the electrodes 12a and 12b are sandwiched by the insulating films 13a and 13b, and the extended portions 121a and 121b of the electrodes are also sandwiched in the same manner. Note that the method of sandwiching with an insulating film is not particularly limited, and the insulating film can be adhered and covered with an adhesive or a heat-adhesive resin powder. Is preferred. Specifically, the sheet pieces 11a, 11b, 11c, 11d fixed to the support sheet 15 and the electrodes 12a, 12b are sandwiched between two insulating films made of a thermoplastic resin as necessary. Then, it can be laminated with an insulating film by passing between a pair of heating rolls and heating and pressing.

  In the present invention, the method of joining the electrodes 12a and 12b and the lead wire 19 is not particularly limited, and as shown in FIG. 1 (a), the conductive material is formed near the ends of the electrodes 12a and 12b. There is a method of attaching a terminal 17 made of the above material and connecting a lead wire 19 to the terminal 17. The terminal 17 is attached by passing a rivet 171 made of a conductive material through the electrode, the sheet piece and the film from above the sandwiched film, and attaching the terminal 17 by the rivet 171. Yes. In the example of this figure, the terminals 17 and part of the lead wires 19 are further covered with an insulating tape 18.

  In the sheet heating element of the present invention, at least two electrodes made of metal wires are sewn into a conductive sheet piece in which a resin containing conductive powder is supported on a cloth. The heating element can be heated at a relatively low applied voltage, for example, a low applied voltage of 30 V or less. More specifically, for example, even at a low voltage of about 1.2V to 24V, the temperature is preferably 20 to 150 ° C, more preferably 20 to 100 ° C, and still more preferably 20 to 80 ° C. Can do. Therefore, as a power source, a sufficiently high exothermic temperature can be obtained not only for a commercial high voltage AC power source such as 100 V but also for a low voltage such as a battery (dry battery or the like). Therefore, the present invention is not limited to a stationary planar heating element, but can also be applied to a portable and small planar heating element, and is particularly suitable for clothes having flexibility.

  In addition, since the sheet heating element of the present invention has a portion where the conductive sheet piece does not exist, this portion can be bent with a small force, and has a structure with excellent flexibility as a whole. It has become. In addition, electrode wires can be arranged on the conductive sheet pieces at arbitrary intervals, and the conductive sheet pieces can be arranged at arbitrary intervals. It can be a body.

  Note that the use of the planar heating element of the present invention is not particularly limited, and is a heating device having a planar or curved heating portion, such as a heat retaining plate, a heater, a road, a roof, or the like. The present invention can be widely applied to snow melting devices, heating devices such as floors, walls, carpets and blankets, winter clothes, sports clothes, work clothes, insoles, warming waists, warming pouchettes, and the like. In addition, as described above, since it is possible to generate heat even with a low-voltage battery, and because it is excellent in flexibility, it is particularly used in applications in which bending or bending repeatedly occurs, such as an application used with clothing, or an application having a large degree of bending. Is suitable.

  Examples of the present invention will be described below, but these are only suitable examples for facilitating understanding of the invention, and the present invention is not limited to the contents of these examples.

Example 1
In Example 1, a sheet heating element having the form shown in FIGS. 1A and 1B was manufactured by the following process.
As a fabric for supporting a resin containing conductive powder, a fiber web by a spunbond method comprising a splittable long fiber (average fineness 2.4 decitex) made of a polyester resin component and a nylon resin component and having a chrysanthemum cross section. Were entangled with water to prepare a nonwoven fabric in which the long fibers were divided and the long fibers were entangled. The surface density of this nonwoven fabric was 100 g / m ² and the thickness was 0.4 mm. The average fineness of the ultrafine fibers generated by the division was 0.15 dtex.
As a resin containing conductive powder, a powder made of carbon or graphite and an emulsion type dispersion of a copolymer of acrylic ester and styrene are dispersed in water, and a thickener and a surfactant are added. Then, a blended liquid was prepared by increasing the viscosity.
Next, the fabric is impregnated with the compounded liquid using a pair of rubber rolls, and then dried at 120 ° C. for 5 minutes in two steps. Conductivity containing 140 g / m ^{2 of} resin containing conductive powder. Sex sheet was obtained. The surface density of this conductive sheet was 240 g / m ² and the thickness was 0.70 mm. Next, as shown in FIG. 1A, four sheets (11a, 11b, 11c, and 11d) of sheet pieces obtained by cutting the conductive sheet into a size of horizontal 5 cm × vertical 7 cm were produced.
Next, as shown in FIGS. 1 (a) and 1 (b), as the support sheet 15, a fiber web containing a heat-fusible fiber component is heat-sealed between fibers using a pair of heating rolls. A non-woven fabric having a density of 50 g / m ² and a thickness of 0.13 mm (horizontal 13.5 cm × vertical 20 cm) is prepared. On this support sheet 15, conductive sheet pieces are arranged in two rows and two rows. Each was placed at intervals. In addition, the space | interval of 2 cm was opened between 11a and 11b, and the space | interval of 2 cm was also opened between 11b and 11c. Moreover, each sheet piece was fixed on the support sheet 15 with the double-sided adhesive tape 16.
Next, one metal wire composed of six strands of copper element wire having a wire diameter of 0.08 mm is placed on the sheet pieces 11 a and 11 b and the support sheet 15 with an industrial sewing machine so that the seam spacing is about 2 mm. In this way, two electrodes 12a and 12b were sewn in two rows. The two electrodes are provided so as to be spaced apart by 4 cm, and are sewn in the order of 11a, 11b, 11c, and 11d, and have a U-shape as a whole.
Next, this laminated film 2 with the polyethylene vinyl acetate copolymer resin side of the electrically insulating laminated film (thickness: 35 μm) laminated with polyethylene terephthalate resin and polyethylene vinyl acetate copolymer resin (melting point: about 100 ° C.) as the inner side. By sandwiching the sheet pieces 11a, 11b, 11c, 11d and the electrodes 12a, 12b fixed on the support sheet 15 between sheets, and then passing between a pair of heating rolls, heating and pressurizing, Laminated with an insulating film.
Next, as shown in FIG. 1A, a terminal 17 made of a conductive material was attached near the ends of the electrodes 12a and 12b, and a lead wire 19 was connected to the terminal 17. The terminal 17 is attached by passing a rivet 171 made of a conductive material through the electrode, the sheet piece, and the film from above the sandwiched film, and the terminal 17 is attached by the rivet 171. . Next, the terminal 17 and the lead wire were further covered with an insulating tape 18 to obtain a planar heating element.
When a voltage of DC 7V was applied to the lead wire of the obtained sheet heating element for 2 minutes, the surface temperature of the sheet heating element was 70 ° C. at a room temperature of 26 ° C.
In addition, in the planar heating element, a part of the electrode extends from the sheet piece, and the sheet piece is connected via the extended portions 121a and 121b of the electrode. In addition, since the sheet piece does not exist in this extended portion, it can be bent with a small force, and has a structure with excellent flexibility as a whole. This planar heating element repeats bending and bending. It was suitable for applications that occur, such as those used with clothing, or applications that have a large degree of curvature.

(Example 2)
In Example 2, a sheet heating element having the form shown in FIGS. 2A and 2B was manufactured by the following steps.
As a fabric for supporting a resin containing conductive powder, a fiber web by a spunbond method comprising a splittable long fiber (average fineness 2.4 decitex) made of a polyester resin component and a nylon resin component and having a chrysanthemum cross section. Were entangled with water to prepare a nonwoven fabric in which the long fibers were divided and the long fibers were entangled. The surface density of this nonwoven fabric was 100 g / m ² and the thickness was 0.4 mm. The average fineness of the ultrafine fibers generated by the division was 0.15 dtex.
As a resin containing conductive powder, a powder made of carbon or graphite and an emulsion type dispersion of a copolymer of acrylic ester and styrene are dispersed in water, and a thickener and a surfactant are added. Then, a blended liquid was prepared by increasing the viscosity.
Next, the fabric is impregnated with the compounded liquid using a pair of rubber rolls, and then dried at 120 ° C. for 5 minutes in two steps. Conductivity containing 140 g / m ^{2 of} resin containing conductive powder. Sex sheet was obtained. The surface density of this conductive sheet was 240 g / m ² and the thickness was 0.70 mm. Next, as shown in FIG. 2A, four pieces (11a, 11b, 11c, 11d) of sheet pieces cut into a size of 5 cm wide × vertical 7 cm were produced from this conductive sheet.
Next, as shown in FIGS. 2 (a) and 2 (b), as the support sheet 15, a fiber web containing a heat-fusible fiber component is heat-sealed between the fibers using a pair of heating rolls. A non-woven fabric having a density of 50 g / m ² and a thickness of 0.13 mm (horizontal 13.5 cm × vertical 20 cm) is prepared. On this support sheet 15, conductive sheet pieces are arranged in two rows and two rows. Each was placed at intervals. In addition, the space | interval of 2 cm was opened between 11a and 11b, and the space | interval of 2 cm was also opened between 11b and 11c. Moreover, each sheet piece was fixed on the support sheet 15 with the double-sided adhesive tape 16.
Next, three metal wires made of six strands of copper wire having a wire diameter of 0.08 mm are spaced about 0.8 mm apart, and the sheet pieces 11a, 11b, and the support sheet 15 with an industrial sewing machine, Two electrodes 12a and 12b were sewn in two rows so that the distance between the stitches was about 2 mm. The two electrodes are provided so as to be spaced apart by 4 cm, and are sewn in the order of 11a, 11b, 11c, and 11d, and have a U-shape as a whole.
Next, this laminated film 2 with the polyethylene vinyl acetate copolymer resin side of the electrically insulating laminated film (thickness: 35 μm) laminated with polyethylene terephthalate resin and polyethylene vinyl acetate copolymer resin (melting point: about 100 ° C.) as the inner side. By sandwiching the sheet pieces 11a, 11b, 11c, 11d and the electrodes 12a, 12b fixed on the support sheet 15 between sheets, and then passing between a pair of heating rolls, heating and pressurizing, Laminated with an insulating film.
Next, as shown in FIG. 2A, a terminal 17 made of a conductive material was attached in the vicinity of the ends of the electrodes 12 a and 12 b, and a lead wire 19 was connected to the terminal 17. The terminal 17 is attached by passing a rivet 171 made of a conductive material through the electrode, the sheet piece, and the film from above the sandwiched film, and the terminal 17 is attached by the rivet 171. . Next, the terminal 17 and the lead wire were further covered with an insulating tape 18 to obtain a planar heating element.
When a voltage of DC 7V was applied to the lead wire of the obtained sheet heating element for 2 minutes, the surface temperature of the sheet heating element was 71 ° C. at a room temperature of 26 ° C.
In addition, in the planar heating element, a part of the electrode extends from the sheet piece, and the sheet piece is connected via the extended portions 121a and 121b of the electrode. In addition, since the sheet piece does not exist in this extended portion, it can be bent with a small force, and has a structure with excellent flexibility as a whole. This planar heating element repeats bending and bending. It was suitable for applications that occur, such as those used with clothing, or applications that have a large degree of curvature.

(A) is a top view which shows an example of the planar heating element by this invention, (b) is typical sectional drawing of the D-D 'line | wire of (a). (A) is a top view which shows another example of the planar heating element by this invention, (b) is typical sectional drawing of the A-A 'line of (a). (A) is a top view which shows another example of the planar heating element by this invention, (b) is typical sectional drawing of the B-B 'line | wire of (a). (A) is a top view which shows another example of the planar heating element by this invention, (b) is typical sectional drawing of the C-C 'line | wire of (a). The schematic diagram which shows an example of arrangement | positioning of the electroconductive sheet piece of the planar heating element by this invention

Explanation of symbols

10 Sheet heating elements 11a, 11b, 11c, 11d, 11d Conductive sheet pieces 12a, 12b Electrodes 121a, 121b Electrode extending portions 122a, 122b Electrode extending portions 13a, 13b Electrical insulating film 14 Fabric 15 Support sheet 16 Double-sided adhesive tape 17 Terminal 171 Rivet 18 Electrical insulating tape 19 Lead wire

Claims (6)

  At least two electrodes made of metal wires are sewn into at least two conductive sheet pieces in which a resin containing conductive powder is carried on a cloth, and the electrodes are separated from the sheet pieces. A surface that is partially extended, the sheet pieces are connected via an extended portion of the electrode, and the sheet piece and the electrode are sandwiched between insulating films. Heating element.   The planar heating element according to claim 1, wherein the metal wire includes a plurality of metal wires.   The planar heating element according to claim 1 or 2, wherein the sheet piece is placed on a support sheet, and an electrode including the extending portion is sewn into the support sheet.   The planar heating element according to any one of claims 1 to 3, wherein the shape of the sheet piece is rectangular, and adjacent sides of two adjacent sheet pieces are substantially parallel to each other.   L1 is 2 to 100 times L2 where L1 is the length of the electrode sewn into the sheet piece and L2 is the length of the electrode extending from the sheet piece. Item 5. The planar heating element according to any one of Items 1 to 4. At least two conductive sheet pieces carrying a resin containing conductive powder on a fabric are placed on a support sheet at intervals, and then at least two electrodes made of metal wires are separated from each other. A method of manufacturing a planar heating element, wherein the sheet piece and the support sheet are sewn together, and then the sheet piece, the electrode and the support sheet are sandwiched by an insulating film.

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