JP2009009706A - Planar heating element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve problems that a conventional planar heating element lacks in flexibility with a multilayer structure and, when used for a car seat heater or the like, a feeling of seating is spoiled and due to the deformation of the planar heating element, an electrode is damaged by bent wrinkle or the like and durability is poor with small PTC characteristics. <P>SOLUTION: The planar heating element 1 is composed of a resin composition and a conductor, and the conductor is constructed of a polymer resistor 5 of tungsten or a tungsten compound. This planar heating element 1 is superior in a feeling of use and productivity as it is constructed of a material with a simple structure and flexibility. Furthermore, since it contains noncombustible and high conductive conductor, it is excellent in low resistance, and PTC characteristics and has fire retardancy. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a polymer resistor composition having excellent PTC characteristics and a deformable surface having flexibility and high reliability that can be attached to an instrument having an arbitrary surface shape using the polymer resistor composition. Related to a heating element.

  Conventionally, in this type of planar heating element, a heating element is used that is produced by printing, drying, and firing a resistor ink in which a heating part is dispersed in a base polymer and a conductive material in a solvent.

  This resistor generates heat when energized. In this type of resistor, carbon black, metal powder, graphite, or the like is generally used as a conductive substance, and a crystalline resin is used as a base polymer. With such a material, the heat generating portion exhibits PTC characteristics (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3).

  FIG. 9 shows a conventional planar heating element 30 described in Patent Document 1, and includes a base material 31, a pair of comb-shaped electrodes 32 and 33, a polymer resistor 34, and a covering material 35.

  The electrically insulating substrate 31 is made of a resin such as a polyester film. The comb-shaped electrodes 32 and 33 are formed by printing and drying a conductive paste such as a silver paste on the substrate 31.

  The polymer resistor 34 is formed by printing and drying polymer resistor ink at a position where power is supplied by the comb-shaped electrodes 32 and 33.

  The covering material 35 made of the same material as the base material 31 covers and protects the comb-shaped electrodes 32 and 33 and the polymer resistor 34.

  When using a polyester film as the base material 31 and the covering material 35, a heat-fusible resin 36 such as a modified polyethylene is bonded to the covering material 35 in advance. Then, pressurizing while applying heat.

  By doing in this way, the base material 31 and the coating | covering material 35 are joined via the heat-fusible resin 36. FIG. The covering material 35 and the heat-fusible resin 36 isolate the comb-shaped electrodes 32 and 33 and the polymer resistor 34 from the outside. Therefore, long-term reliability is imparted to the planar heating element 30.

  FIG. 10 shows a schematic configuration of an apparatus for bonding the covering material 35. As described above, a laminator 39 including two heating rolls 37 and 38 is generally used as a heating and pressurizing method.

  That is, the base material 31 on which the comb-shaped electrodes 32 and 33 and the polymer resistor 34 are formed in advance and the covering material 35 on which the heat-fusible resin 36 is bonded in advance are supplied, and these are heated by the heating rolls 37 and 38. Pressurize.

  The PTC characteristic means a resistance temperature characteristic in which the resistance value increases as the temperature rises, and the resistance value increases rapidly when a certain temperature is reached. The polymer resistor 34 having PTC characteristics can give the planar heating element 30 a self-temperature adjusting function.

  In addition, in Patent Document 2, a PTC composition composed of amorphous polymer, crystalline polymer particles, conductive carbon black, graphite, and an inorganic filler is dispersed in an organic solvent to prepare an ink. A planar heating element is described in which a polymer resistor is printed with a PTC composition ink on a resin film provided with a heat treatment for crosslinking, and a resin film is laminated as a protective layer of the polymer resistor. .

  The planar heating element described in Patent Document 2 has a heat generation function similar to that of Patent Document 1.

  FIG. 11 shows another conventional planar heating element 40 described in Patent Document 3, in which electrodes 42 and 43 and a polymer resistor 44 are sequentially laminated on a flexible substrate 41 by a printing method. In addition, a flexible coating layer 45 is formed.

  The flexible base material 41 has a function of impregnating a liquid such as gas barrier property and waterproof property, polymer resistor ink, etc., and a polyester non-woven fabric composed of long fibers and a hot surface such as polyurethane on the surface of the polyester non-woven fabric. The melt film is laminated.

  On the other hand, the flexible coating layer 45 has gas barrier properties and waterproof properties and covers the electrodes 42 and 43 and the polymer resistor 44 as a whole. The polyester nonwoven fabric and the surface of the polyester nonwoven fabric are hot-melted such as polyester. It is the structure which bonded the film together, and is adhere | attached with the flexible base material 41. FIG.

  Therefore, the planar heating element 40 in Patent Document 3 has a six-layer structure in total. The planar heating element of this Patent Document 3 also has a heat generation function similar to that of Patent Document 1.

  As the resin exhibiting the PTC characteristics of the polymer resistor 44, a modified olefin resin which is a low melting point resin, such as ethylene vinyl acetate copolymer, ethylene ethyl acrylate copolymer, ethylene methyl methacrylate copolymer, ethylene Ester-based ethylene copolymers such as methacrylic acid copolymers and ethylene butyl acrylate are used, and are generally crosslinked by methods such as crosslinking materials and ultraviolet irradiation to suppress changes due to changes in resistance over time. is there.

Here, the resistance change magnification (R50 / R20), which is the ratio of the resistance value of 50 ° C. and the resistance value of 20 ° C. of the polymer resistor 44, is all 2 or less.
Japanese Patent Laid-Open No. 56-13689 JP-A-8-120182 US Pat. No. 7,049,559

  In the conventional planar heating element 30 of Patent Documents 1 and 2, a rigid material such as a polyester film is used as the base material 31. The substrate 31 has a five-layer structure including a comb-shaped electrode 32, 33 printed thereon, a polymer resistor 34, and a covering 35 having an adhesive layer disposed thereon. .

  Therefore, depending on the material and the thickness of the base material 31 and the covering material 35, flexibility is lacking. That is, when the planar heating element 30 is used as a car seat heater (heater for heating a seat of an automobile), the seating feeling is impaired, and when it is used as a handle heater, the feeling of touch is impaired.

  Moreover, since the shape is planar, when a load due to seating or the like is applied to a part of the surface, the force is exerted on the entire surface and the planar heating element 30 is deformed.

  Depending on the shape of the deformation, the closer to the end of the sheet heating element 30, the larger the amount of deformation, causing creases or the like in part of the surface. There is a possibility that cracks or the like may occur in the comb-shaped electrodes 32 and 33 and the polymer resistor 34 in the folded portion. Therefore, durability may be reduced.

  Further, since the base material 31 such as a non-breathable polyester sheet and the covering material 35 are used, moisture is likely to be trapped when used for a car seat heater or a handle heater. Therefore, when used for a long time, the seating feeling and the touch feeling are impaired.

  On the other hand, the sheet heating element 40 of Patent Document 3 is used as a seat heater or a steering wheel heater of an automobile because the base material and covering layer of the electrodes 42 and 43 and the polymer resistor 44 have flexibility. Although the seating feeling and the touch feeling are good, the planar heating element 40 has a six-layer structure, so that the productivity is poor and the cost is increased as a result.

  Further, the conventional PTC characteristics are not sufficient in terms of energy saving and quick heat, and have a problem that the resistance change magnification is low. In addition, since conventional carbon black and graphite, which are conductive, are flammable, it is necessary to add a flame retardant.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object of the present invention is to provide a planar heating element that easily exhibits flexibility even when an external force is applied and is excellent in flame retardancy.

  In order to solve the above-described conventional problems, the planar heating element of the present invention includes a resin composition in which a main component is cross-linked through a reactive resin and a conductor, and the conductor is tungsten or a tungsten compound. It is equipped with a polymer resistor characterized by

  Thereby, low resistance and high change magnification can be realized, and flame retardancy can be imparted.

  Moreover, since the resin composition is bridge | crosslinked, the resistor composition can suppress the time-dependent change of a specific resistance value. Thereby, stable PTC characteristics over a long period, that is, stable heat generation performance can be realized.

  The planar heating element of the present invention is composed of a polymer resistor having high PTC characteristics, so that it has excellent performance as a heating element and can realize excellent flame resistance over a long period of time. Since the productivity is high, productivity can be improved and a low-cost polymer resistor can be produced.

  Further, in contrast to the conventional sheet heating element having a five- to six-layer structure, the present invention has a three-layer structure so that the sheet heating element is highly flexible and strong against deformation caused by external force. Is something that can be done.

  According to a first aspect of the present invention, there is provided a polymer resistor comprising a resin composition whose main component is crosslinked through a reactive resin and a conductor, wherein the conductor is tungsten or a tungsten compound. It is a thing.

  Tungsten and tungsten compounds do not burn. Moreover, not only can the resistance value be lowered due to high conductivity, but also the resistance change magnification is as high as 2 or more.

  In addition, since the resin composition is cross-linked, it is possible to suppress the time-dependent change of the specific resistance value and to obtain stable PTC characteristics over a long period of time. In other words, it is possible to realize a stable heat generation performance by preventing a decrease or rise in a preset heat generation temperature. Thereby, comfortable heating is realizable.

  According to a second aspect of the present invention, there is provided an electrically insulating substrate, at least one pair of electrodes disposed on the electrically insulating substrate, and electrically connected to the pair of electrodes, the main component being a reactive resin. A sheet heating element comprising a polymer resistor characterized in that it is composed of a resin composition cross-linked through a conductive material and a conductor, and the conductor is tungsten or a tungsten compound. It becomes a layer, and it becomes easy to exhibit a softness | flexibility rather than the conventional planar heating element.

  Therefore, the planar heating element is easily deformed by external force, so that the polymer resistor can be prevented from cracking or peeling due to creases, and the durability and reliability of the planar heating element are improved. .

  In addition, since a resin film such as a non-breathable polyester sheet is not used with a polymer resistor in between, the problem that moisture tends to be trapped like conventional sheet heating elements is solved, and even when used for a long time A feeling of touch equivalent to that of the initial stage can be obtained, and a comfortable heating effect can be obtained.

  Further, the planar heating element of the present invention has a simple three-layer structure, so that the productivity can be improved and the cost can be reduced.

  In a third aspect of the invention, the conductor is tungsten carbide. Not only does the compound not burn, but also a large resistance change ratio can be maintained by adding the compound.

  In the fourth invention, in particular, the resin composition contained in the first or second invention is a composition of a reactive resin that exhibits at least PTC characteristics and a reactive resin, whereby the conductor is a reactive resin. It is possible to stabilize the conductive path formed of the conductor by capturing with the adhesive force and bonding force.

  Furthermore, due to the bonding force between the reactive resin and the reactive resin that exhibits PTC characteristics, the temperature characteristics of the expansion coefficient and the change over time of the melting temperature due to repeated cooling are suppressed, and the conductive path can be further stabilized. . As a result, physical, chemical, and electrical behavior can be stabilized, so that stable PTC characteristics can be realized over a long period of time.

  In the fifth invention, in particular, the resin composition contained in the resistor composition B of the first or second invention is composed mainly of a carboxyl group, a carbonyl group, a hydroxyl group, an ester group, a vinyl group, an amino group, an oxazoline. And a reaction resin containing at least one functional group of a maleic anhydride group and at least one functional group of an epoxy group, an oxazoline group and a maleic anhydride group whose main component is different from the functional group of the reaction resin By making a composition comprising a reactive resin containing a group, a chemical bond is formed by a reaction between the reactive resin and the functional group having the polarity of the reactive resin, and the thermal stability of the reactive resin alone is increased. be able to.

  Thereby, similarly to the fourth invention, physical, chemical, and electrical behavior can be stabilized, so that stable PTC characteristics can be realized over a long period of time.

According to the sixth aspect of the invention, in particular, by adding a thermoplastic elastomer to the resin composition, flexibility can be imparted to the resistor composition constituting the polymer resistor, so that it follows the deformation due to external force. Even if mechanical stress is repeated, the polymer resistor is prevented from cracking and breaking, and excellent durability and reliability can be realized. In addition, the flexibility of the resistor composition is increased, so that the processability of the polymer resistor is improved and the productivity is improved.

  In the seventh invention, in particular, by using at least one of olefin, styrene, urethane, and polyester as the thermoplastic elastomer of the sixth invention, the action of the sixth invention is more effectively expressed. be able to.

  According to an eighth aspect of the present invention, the polymer resistor of the first or second aspect is a flexible sheet or film, so that even if an external force is applied to the planar heating element, it is as high as the electrically insulating substrate. Since the molecular resistor itself stretches or deforms in response to an external force, the polymer resistor is prevented from being damaged such as cracking or breaking, thereby realizing excellent durability.

  In the ninth aspect of the invention, in particular, the electrode of the second aspect of the invention is composed of at least one type of wire electrode of a metal conductor and a metal braided conductor, so that the metal conductor and the metal braided conductor are excellent in flexibility and mechanical. Because of its high strength, it can withstand long-term use even if the planar heating element is repeatedly stretched, bent, or deformed.

  Further, the selection range of the material and shape of the metal conductor and the metal braided conductor is widened. Furthermore, the electrical base material insulation and the sewing to the polymer resistor are facilitated, and the productivity is improved.

  In the tenth invention, in particular, the electrically insulating base material of the second invention is composed of at least one of a woven fabric and a non-woven fabric, so that flexibility is imparted to the planar heating element and even if an external force is applied. Will be deformed.

  The eleventh aspect of the invention is the sheet heating device of the first to tenth aspects of the invention in an automobile seat device, and the twelfth aspect of the invention is the planar heating element of the first to tenth aspects of an automobile handle device. It has been installed in and realized comfortable heating.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the present embodiment.

(Embodiment 1)
In FIG. 1, the planar heating element 1 includes an electrically insulating substrate 2, a first filament electrode 3 </ b> A, a second filament electrode 3 </ b> B, and a polymer resistor 5.

  The linear electrodes 3A and 3B are arranged on the electrically insulating base material 2 so as to be symmetrical with each other and are partially sewn with a thread 4.

  The polymer resistor 5 is formed on the electrically insulating substrate 2 on which the linear electrodes 3A and 3B are arranged by being extruded into a film shape by, for example, a T-die extrusion method.

  As a result, the polymer resistor 5 is thermally fused to the linear electrodes 3A and 3B and the electrically insulating substrate 2.

  The central portion of the planar heating element 1 is punched after the polymer resistor 5 is thermally fused to the linear electrodes 3A and 3B and the electrically insulating substrate 2.

  In addition, the lead wire for supplying the electric power from a power supply to the filament electrodes 3A and 3B is not illustrated. Further, the punching of the central portion is not limited to this place, and may be provided at other places depending on the material and shape. In this case, the wiring pattern of the line electrode 3 is changed.

  FIG. 2 shows an automobile seat apparatus to which the planar heating element 1 shown in FIG. 1 is attached.

  The planar heating element 1 is used by being attached to a seat portion 6 or a backrest 7 which is a seat device of an automobile so that the electrically insulating base material 2 is located on the surface side. A seat base 8 and a skin 9 are used for the seat 6 and the backrest 7.

  The seat base material 8 such as a urethane pad is deformed when a load is applied by a human body seated on the seat, and the shape is restored when the load is no longer applied.

  The skin 9 covers the seat base 8. That is, the planar heating element 1 is attached by arranging the polymer resistor 5 side on the seat base material 8 and the electrically insulating base material 2 side on the skin 9.

  In addition, in order to correspond to the hanging part (not shown) of the seat part 6 and the backrest 7, the extension part (not shown) of the electrically insulating base material 2 for hanging in a center part or a peripheral part is provided. There may be.

  Thus, the thin planar heating element 1 is disposed along the seat base 8 and the skin 9 that can be deformed. Therefore, the planar heating element 1 must be similarly deformed corresponding to the deformation of the seat 6 and the backrest 7.

  Therefore, it is necessary to design various heat generation patterns and change the arrangement shape of the line electrodes 3 for that purpose, but the details are omitted here.

  A pair of wide linear electrodes 3 </ b> A and 3 </ b> B arranged so as to face each other are disposed along the outer side in the longitudinal direction of the planar heating element 1.

  By supplying power from the filament electrodes 3A and 3B, a current flows through the polymer resistor 5 to generate heat.

  The polymer resistor 5 has a PTC characteristic, and has a self-temperature adjusting function so that the resistance value increases as the temperature rises to reach a predetermined temperature.

  That is, the polymer resistor 5 gives the planar heating element 1 a function that is highly safe and does not require temperature control. In addition, as a car seat heater incorporated in an automobile seat, the planar heating element 1 can satisfy a seating feeling and flame retardancy. The seating feeling can be satisfied by the fact that there is no squeaking like paper and an elongation characteristic equivalent to that of the seat skin material, that is, a load of 7 kgf or less for 5% elongation.

  In addition, the planar heating element 1 having the PTC characteristic can exhibit quick heat and energy saving as compared with the heating element having no PTC characteristic.

  A heating element having no PTC characteristic requires a temperature controller, and the temperature controller controls the heat generation temperature by controlling energization by ON-OFF control.

  In particular, in the case of a heating element having a PTC characteristic using a filament heating wire, the heating element temperature at the time of ON is raised to about 80 ° C. in order to avoid a low temperature portion between the filament heating wires. Need to be placed at some distance.

  On the other hand, in the planar heating element 1, the heating element temperature is self-controlled within the range of 40 ° C to 45 ° C. Therefore, it can be arranged close to the vicinity of the skin 10.

Since the sheet heating element 1 has a low heating element temperature and is disposed in the vicinity of the skin 9, it can reduce the rapid heating property and heat radiation loss to the outside. Therefore, energy saving can be realized.

  As described above, in the planar heating element 1 of the present embodiment, the conventional planar heating element has a 5-6 layer structure of a base material, an electrode, a polymer resistor, a heat-fusible resin, and a coating material. In contrast to this, it has a three-layer structure of an electrically insulating substrate 2, a pair of filament electrodes 3, and a polymer resistor 5.

  With this simple configuration, even when an external force is applied, the restriction of the external force is reduced, and thus flexibility is easily exhibited.

  Therefore, even when subjected to an external force when used as a car seat heater, it is highly flexible and easily deformed, and cracking and peeling of the polymer resistor caused by creases as in the prior art are prevented.

  In addition, the planar heating element 1 can be manufactured with a simple configuration of three layers, so that it is excellent in productivity, and the material cost for configuring the planar heating element 1 is reduced, so that it can be produced at a lower cost.

  Further, since a resin film such as a non-breathable polyester sheet is not used with the polymer resistor 5 interposed therebetween, moisture is accumulated when it is used for a car seat heater or a handle heater like a conventional sheet heating element. The problem of being easy to solve is solved, and even when used for a long time, a feeling of sitting and touch equivalent to the initial stage can be obtained, and a comfortable heating effect can be obtained.

  As the electrically insulating base material 2, for example, a needle punch type nonwoven fabric made of polyester fiber is used.

  Besides this, a polyester woven fabric may be used. These electrically insulating base materials 2 impart flexibility to the planar heating element 1 and easily deform even when an external force is applied to improve the seating feeling when used as a car seat heater.

  In particular, when the filament electrode 3 is attached by sewing, the above nonwoven fabric and woven fabric are optimal in terms of prevention of cracks generated from the needle holes of the electrically insulating base material 2 by sewing and flexibility.

  The filament electrodes 3A and 3B are attached to the electrically insulating base material 2 by sewing with a sewing machine or the like. According to the structure produced by this method, the linear electrodes 3A and 3B can be firmly fixed to the electrically insulating substrate 2 and deformed following the deformation of the electrically insulating substrate 2, and mechanical reliability is improved. improves.

  Moreover, since the sewing to the electrically insulating base material 2 is performed by the thread 4, the selection range of the electrode material and the shape is expanded.

  Furthermore, unlike the conventional complicated comb-shaped electrodes, the linear electrodes 3A and 3B can be formed into a simple configuration having at least a pair of linear shapes, so that the material cost is low and the cost can be reduced.

  Further, even when an external force is applied when used as a car seat heater, the generation of wrinkles on the filament electrode 3 is suppressed, and the electrode is prevented from being damaged.

  The filament electrodes 3A and 3B are composed of at least one of a metal conductor and a metal braided conductor. These materials are easy to sew to the electric base material insulation 2 and have high productivity.

  Further, the selection range of the material and shape of the metal conductor and the metal braided conductor is widened.

  Further, since the metal conductor and the metal braided conductor are excellent in flexibility and have high mechanical strength, they can endure for a long period of time even if the planar heating element is repeatedly stretched, bent, or deformed.

  In addition, since the electrode is composed of a filament, unlike the conventional complicated comb-shaped electrode, it can have a simple structure, and the cost of the electrode material can be reduced.

  It is preferable that the wire electrodes 3A and 3B have a resistance as low as possible and have a small voltage drop.

  The linear electrodes 3A and 3B are suitable to have a resistance value at which a voltage drop of a voltage applied to the planar heating element 1 is 1 V or less, and is preferably 1 Ω / m or less in terms of the resistance value.

  Moreover, since the unevenness | corrugation will be formed in the planar heating element 1 and the seating feeling will be impaired if the wire diameter of the line electrodes 3A and 3B is large, the diameter is preferably 1 mm or less, and in order to realize a more comfortable seating feeling. The diameter is preferably 0.5 mm or less.

  Examples of the material that realizes the resistance value include copper, tin-plated copper, copper-silver alloy single wire, stranded wire, and braided wire. Particularly, in terms of mechanical strength, it is preferable to use copper-silver having high tensile strength.

  In this embodiment, the line electrode 3 is used as an electrode. However, the present invention is not limited to this, and a metal foil electrode, an electrode film by screen printing such as a silver paste, or the like can also be used.

  The resin composition of the polymer resistor 5 reacts with a modified polyethylene having a carboxyl group as a reaction resin that expresses PTC and a reaction resin in order to suppress a change in PTC characteristics with time and reproduce a stable PTC characteristic. What mixed the modified polyethylene which has an epoxy group as a reactive resin to perform is good.

  This is because the carbonyl group of the reactive resin reacts with the oxygen of the epoxy group of the reactive resin to be chemically bonded and has a crosslinked structure.

  By this crosslinking reaction, as described above, the thermal stability can be improved compared to the case of the resin alone, and as a result, the temperature at which the conductive path of the conductor in the resin composition is formed and cut is reduced. Stabilize.

  This cross-linking reaction can occur even through nitrogen in addition to oxygen. If a combination of a reactive resin having a functional group containing at least one of oxygen and nitrogen and a reactive resin having a functional group capable of reacting with these functional groups, a crosslinking reaction will occur, and the resin composition As a combination of the reactive functional group of the reactive resin and the functional group of the resin to be reacted, there are the following in addition to the above-described epoxy group and carbonyl group.

  The epoxy group undergoes addition polymerization by reacting with a carboxyl group, an ester group, a hydroxyl group, an amino group, a vinyl group, a maleic anhydride group, or an oxazoline group in addition to the above carbonyl group. A reaction resin having these functional groups may be used.

  On the other hand, as a functional group of the reactive resin, a reactive resin having an oxazoline group or a maleic anhydride group in addition to an epoxy group can be used.

  Thus, the resin composition has a structure crosslinked through at least one of oxygen and nitrogen.

  When the exothermic temperature is relatively low as 40 to 50 ° C. like a car seat heater, a modified olefin resin that is a low melting point resin such as an ethylene vinyl acetate copolymer, It is preferable to use ester ethylene copolymers such as ethylene ethyl acrylate copolymer, ethylene methyl methacrylate copolymer, ethylene methacrylic acid copolymer, and ethylene butyl acrylate.

  The above-mentioned reactive resin and reactive resin can be used either individually or in combination, and are appropriately selected according to the target PTC characteristics.

  In addition, it is also possible to use a reactive resin or a reactive resin alone depending on the allowable range of change with time in PTC characteristics.

  Moreover, although reactive resin was used for the crosslinking reaction, the crosslinking agent different from reactive resin can also be used.

  Furthermore, crosslinking means such as an electron beam can be used. In that case, the above-described reactive resin having no functional group is applicable, and it is not necessary to use a reactive resin.

  Moreover, in order to exhibit the above-mentioned effect more, it is useful to make the polymer resistor 5 contain a thermoplastic elastomer. By containing a thermoplastic elastomer, flexibility can be imparted to the polymer resistor 5, so that it can follow deformation due to external force, and even if mechanical stress is repeated, Breakage is prevented, and excellent durability and reliability can be realized.

  In addition, the increased flexibility improves the processability of the polymer resistor 5 film and improves the productivity.

  By using at least one of olefin-based, styrene-based, urethane-based, and polyester-based materials as the thermoplastic elastomer material, flexibility can be more effectively expressed.

  As described above, by optimizing the composition of the resin constituting the polymer resistor 5, it is possible to achieve stable film processing, excellent durability, and reliability of the polymer resistor 5, There is a problem that the PTC characteristic of the polymer resistor 5, that is, the resistance change magnification of 20 ° C. and 50 ° C. cannot be obtained twice or more.

  Therefore, tungsten or tungsten carbide is used as the conductor.

  When the content of tungsten or tungsten carbide in the polymer resistor 5 is 90% by weight, the resistance change magnifications were 5 times and 9 times, respectively. it can.

  If it is 80% by weight or less, the resistance becomes high and cannot be used.

  The above-mentioned characteristics can be realized if the content of the reactive resin constituting the polymer resistor 5 is 1 to 20% by weight, preferably 1 to 10% by weight, particularly of the polymer resistor 5 In order to improve the workability and the PTC characteristics, the resistor composition B13 is best in the range of 2 to 5% by weight.

Moreover, content of the thermoplastic elastomer in the case of making it contain in a resin composition is 5 to 20 weight%
Is preferable in terms of improvement in flexibility.

  Next, an example of a method for manufacturing the planar heating element 1 will be described.

  First, an electrically insulating base material 2 made of polyester fiber non-woven fabric is formed by twisting 19 copper-silver alloy wires having a diameter of 0.05 .mu.m into a shape shown in FIG. Then, the line electrode 3 is formed. The distance between the pair of linear electrodes 3A and 3B at this time is 100 mm.

  Next, the resin to be reacted, the reactive resin, and the conductor that express the PTC characteristics are kneaded and mixed, extruded from a T die connected to an extrusion apparatus, and molded into a film.

  In this way, the polymer resistor 5 is manufactured. In addition, kneading | mixing mixing is performed with apparatuses, such as a hot roll, a kneader, and a biaxial kneader.

  The thickness of the polymer resistor 5 is not particularly limited, but 20 to 200 μm is appropriate in terms of flexibility, material cost, appropriate resistance value, and strength when a load is applied. 30-100 micrometers is good.

  Next, the polymer resistor 5 molded into a film and extruded from the T-die is a surface on which the filament electrodes 3 of the electrically insulating substrate 2 to which the filament electrodes 3A and 3B prepared in advance are attached. And heat-sealed by a laminator. The planar heating element 1 is completed as described above.

  The linear electrodes 3A and 3B and the polymer resistor 5, the electrically insulating substrate 2 and the polymer resistor 5 are joined by thermal fusion, respectively, so that the linear electrodes 3A and 3B are electrically insulated substrate. 2 and the polymer resistor 5 are arranged in an electrically connected state.

  The polymer resistor 5 is a flexible sheet or film, so that even if an external force is applied to the planar heating element 1, the polymer resistor 5 itself responds to the external force in the same manner as the electrically insulating substrate 2. Since elongation and deformation occur, breakage such as cracks and breaks of the polymer resistor 5 is prevented, and excellent durability is realized.

  Further, by forming the polymer resistor 5 in the form of a sheet or film, the film thickness can be made thicker than the polymer resistor of the printed film, and electrical connection with the linear electrodes 3A and 3B and the machine The reliability of the joint is increased.

  Furthermore, since the polymer resistor 5 continuously extruded can be bonded while being bonded to the electrically insulating substrate 2 to which the filament electrode 3 is attached, the productivity is excellent and low cost can be realized.

  The polymer resistor 5 preferably has an elongation equal to or greater than that of the electrically insulating substrate 2.

  By making the elongation of the polymer resistor 5 equal to or higher than that of the electrically insulating substrate 2, the electrically insulating substrate 2 having a high mechanical strength can regulate elongation and deformation due to external force, and thus is more excellent. Durability and reliability.

  Further, by arranging the polymer resistor 5 on the electrically insulating substrate 2 and the filament electrode 3, the polymer resistor 5 is attached to the electrically insulating substrate 2 to which the filament electrodes 3A and 3B are previously attached. A manufacturing method can be adopted.

  According to this manufacturing method, since the polymer resistor 5 immediately after molding is in a high temperature state, the polymer resistor 5 is easily and firmly bonded to the linear electrode 3 and the electrically insulating substrate 2. As a result, electrical connection and mechanical joining can be obtained stably.

  Furthermore, by thermally fusing the polymer resistor 5 to the line electrodes 3A and 3B, the material of the polymer resistor 5 moves around the line electrodes 3A and 3B, and the line electrodes 3A and 3B are high. The molecular resistor 5 can be a surface adhesion instead of a point adhesion.

  As a result, the mechanical joining and electrical connection between the line electrodes 3A and 3B and the polymer resistor 5 are strengthened, and the sheet heating element 1 is obtained which is electrically and mechanically stable.

  The planar heating element 1 configured as described above is preferably used by being disposed on the seat portion 6 or the backrest 7 so that the electrically insulating base material 2 is on the surface side.

  That is, with the cushioning property of the electrically insulating base material 2, the unevenness due to the thickness and hardness of the linear electrodes 3A and 3B is not felt on the seating surface, and the seating feeling and the backrest feeling are not impaired.

  In addition, when flame resistance is imparted to the electrically insulating base material 2, it is possible to prevent the spread of fire in combustion by arranging the electrically insulating base material 2 on the surface side, and a highly safe seat is obtained.

(Embodiment 2)
FIG. 3 shows the second embodiment. The difference from the first embodiment is that the linear electrodes 3A and 3B are formed in a wave shape.

  The other configuration is the same as that of the first embodiment.

  With this configuration, even when an external force that causes elongation or deformation is applied to the planar heating element 1, the linear electrodes 3A and 3B have a margin as the electrodes due to the waveform shape, and thus the linear electrodes 3A and 3B. As a result, the tension, elongation, bending, and other forces received by the material are alleviated, and a material having superior mechanical strength, such as flexibility, can be obtained rather than a linear arrangement.

  Thereby, the planar heating element 1 in which the mechanical joining and electrical connection between the line electrodes 3A and 3B and the polymer resistor 5 are stable over a long period of time is obtained, and the durability and reliability are improved.

  In addition, the potential in the polymer resistor 5 is equalized in a region corresponding to the waveform width of the polymer resistor 5, and the temperature distribution of heat generation in the polymer resistor 5 becomes uniform.

(Embodiment 3)
FIG. 4 shows a third embodiment of the present invention. The difference from the first embodiment is that a line auxiliary electrode 10 is arranged between a pair of line electrodes 3A and 3B.

  That is, the filament auxiliary electrode 10 is disposed between the pair of filament electrodes 3A and 3B of the electrically insulating substrate 2, and the thread 11 made of polyester fiber or the like is used in the sewing machine in the same manner as the filament electrodes 3A and 3B. Is fixed by sewing.

  In the configuration of FIG. 1, there is a case where the temperature is partially kept between the line electrodes 3A and 3B, the resistance value of the portion increases, and the potential concentrates. When this state further proceeds, a so-called hot line phenomenon occurs in which the temperature of a part of the polymer resistor 5 rises as compared with the temperature of other parts.

However, by providing the filament auxiliary electrode 10, potential concentration inside the polymer resistor 5 is avoided, and the heat generation temperature is equalized.

  As a result, the occurrence of a hot line in the polymer resistor 5 is avoided, the safety of the planar heating element 1 is further increased, and a stable heating performance is obtained.

  In addition, the wire auxiliary electrode 10 can apply a metal conducting wire and a metal braided conducting wire similarly to the filament electrodes 3A and 3B.

  In FIG. 4, two line auxiliary electrodes 10 are arranged between the pair of line electrodes 3 </ b> A and 3 </ b> B. However, the number of the line auxiliary electrodes 10 is not limited to this, and the polymer resistor 5 The number may be determined according to the size, the distance between the electrodes 3A and 3B, and the required heat distribution.

  Moreover, although the filament auxiliary electrode 10 is disposed substantially parallel to the pair of filament electrodes 3A and 3B, this arrangement is not particularly limited, and at least one pair of filament auxiliary electrodes 10 is provided as a pair. The linear electrodes 3A and 3B may be meandered.

  In addition, it is also useful to arrange corrugated filamentary auxiliary electrodes like the corrugated filamentary electrodes 3A and 3B shown in the second embodiment. Of course, combinations of corrugated filament electrodes and corrugated filament auxiliary electrodes can also be applied.

(Embodiment 4)
FIG. 5 shows a fourth embodiment of the present invention. The difference from the first embodiment is that a polymer resistor 5 is disposed between the electrically insulating substrate 2 and the linear electrodes 3A and 3B. is there.

  That is, the polymer resistor 5 is thermally laminated in the form of a film on the electrically insulating substrate 2, and then the linear electrodes 3A and 3B are arranged on the polymer resistor 5 and sewn with a sewing machine. is there.

  The filament electrodes 3A and 3B and the polymer resistor 5 are subjected to a heat and pressure treatment, and have a strong and stable electrical connection and mechanical connection.

  Even in this configuration, the planar heating element 1 as a car seat heater for automobiles is obtained. And since the line electrodes 3A and 3B are on the polymer resistor 5, it is easy to confirm the arrangement of the line electrodes 3A and 3B, and the central part of the electrically insulating substrate 2 is performed to increase flexibility. Can be reliably punched out.

  Further, since there is a degree of freedom in the arrangement of the line electrodes 3A and 3B, the process of bonding the polymer resistor 5 to the electrically insulating substrate 2 is made common, and the sheet heating element 1 having various heating patterns is produced. can do.

  Also in this embodiment, a line auxiliary electrode may be provided.

  In addition, the bonding between the linear electrodes 3A and 3B and the polymer resistor 5 is thermally bonded, but the present invention is not limited to this, and the wire is bonded by bonding through a conductive adhesive or mechanical contact by simple pressing. The strip electrodes 3A and 3B and the polymer resistor 5 can be electrically connected.

(Embodiment 5)
FIG. 6 shows a fifth embodiment, which is different from the fourth embodiment in that a polymer resistor 12 in which a nonwoven fabric or a woven fabric having an opening is impregnated with a polymer resistor material is used.

  The polymer resistor 12 is a non-woven fabric or woven fabric prepared by printing, painting, dipping, or the like using an ink produced by dispersing and mixing the polymer resistor materials described in the first to fifth embodiments in a liquid such as a solvent. It is made by impregnating the mesh-shaped opening and drying it.

  After the polymer resistor 12 and the electrically insulating substrate 2 are attached by thermal lamination, the line electrodes 3A and 3B are arranged on the polymer resistor 12, and are attached by sewing with a sewing machine.

  The filament electrodes 3A and 3B and the polymer resistor 12 are subjected to heat and pressure treatment, and they are firmly and stably electrically connected and mechanically joined.

  In this configuration, since the polymer resistor 12 has an opening, the polymer resistor 12 can be easily deformed even when subjected to external force, and can take advantage of the flexibility of the nonwoven fabric and the woven fabric, and thus has high flexibility. .

  Further, since the polymer resistor material is held between the non-woven fabric and the woven fabric as a skeleton, the adhesion of the polymer resistor material is improved, and the mechanical strength as the polymer resistor 12 is improved.

  In the above embodiment, the mesh resistor non-woven fabric or woven fabric having the openings is impregnated with the polymer resistor material with the polymer resistor ink. A mesh-like non-woven fabric or woven fabric having an opening may be impregnated by heat and pressure treatment.

  Moreover, although joining of the line electrodes 3A and 3B and the polymer resistor 12 is thermal bonding, it is not limited to this. The linear electrodes 3A and 3B and the polymer resistor 12 can be electrically connected by adhesion through a conductive adhesive or mechanical contact by simple pressing.

  Moreover, in the said embodiment, you may provide the filament auxiliary electrode 10 of Embodiment 3. FIG.

(Embodiment 6)
FIG. 7 shows the sixth embodiment, which is different from the first embodiment in that a coating layer 13 is further added on the polymer resistor 5.

  That is, an electrically insulating coating layer 13 that covers the polymer resistor 5 and the linear electrodes 3A and 3B is provided.

  Specifically, after the polymer resistor 5 is thermally laminated on the electrically insulating substrate 2 to which the line electrodes 3A and 3B are attached, an electrically insulating coating layer 13 is further thermally laminated. .

  With this configuration, since the polymer resistor 5 can be protected from external impacts and scratches, the planar heating element 1 can be prevented from being damaged.

  Further, since the electrically insulating coating layer 13 can suppress the wear of the polymer resistor 5 even under a situation where an external force is constantly applied and slides like a car seat heater, the heat generation function is not impaired. .

  Moreover, the electrical insulation function when using a high voltage | pressure as a power supply of the planar heating element 1 can also be provided.

  The electrically insulating coating layer 13 preferably covers at least the polymer resistor 5 having low strength. However, it is preferable to use a thin coating layer in consideration of flexibility.

  In order to ensure the flexibility of the planar heating element 1, the material of the electrically insulating coating layer 13 is composed mainly of a polyolefin-based thermoplastic elastomer, a styrene-based thermoplastic elastomer, a urethane-based thermoplastic elastomer or a combination thereof. A combination is used.

  The electrically insulating coating layer 13 can be applied to the configurations of the above-described second to fifth embodiments and has the same effect.

(Embodiment 7)
FIG. 8 shows a sixth embodiment, and a difference from the first embodiment is a deformed shape conforming portion that conforms to a shape deformed by an external force in at least one of the electrically insulating substrate 2 and the polymer resistor 5. A slit 14 is provided.

  That is, the linear electrodes 3A and 3B are disposed on the electrically insulating base 2 and attached by sewing. The polymer resistor 5 is extruded into a film shape or a sheet shape by a T-die extrusion molding method, and the polymer resistor 5 is heat-sealed to the linear electrodes 3A and 3B and the electrically insulating substrate 2.

  And after punching the center part of the electrically insulating base material 2, the position between the strip electrodes 3A and 3B of the polymer resistor 5 is punched with Thomson, and the electrical resistor base material 2 is changed from the polymer resistor 5 to the electrically insulating base material 2. A through slit 14 is provided.

  The punching location at Thomson is not limited to this location, and may be provided at other locations depending on the form of the skin material 9 of the seat shown in FIG.

  In this case, it is necessary to change the wiring pattern of the line electrodes 3A and 3B, but this can be dealt with.

  Although the central portion can be regarded as the deformed shape familiar portion, the central portion is often pulled out depending on the shape of the skin material 9 of the seat, and is therefore distinguished from the deformed shape familiar portion.

  Further, the linear electrodes 3A and 3B and the polymer resistor 5 are attached to the electrical insulating base material 2 which is punched with Thomson in advance and provided with the slits 14, and the polymer is applied to the linear electrodes 3A and 3B and the electrical insulating base material 2. The resistor 5 may be attached.

  Alternatively, the polymer resistor 5 may be attached to a separator (not shown) such as polypropylene or release paper, and the slit 14 may be provided in the polymer resistor 5 by punching at this stage.

  In the former case, the slit 14 is formed only in the electrically insulating substrate 2, and in the latter case, the slit 14 is formed only in the polymer resistor 5.

  As described above, the planar heating element 1 according to the present embodiment is provided with the slits 14 which are deformed shape conforming parts adapted to the shape deformed by the external force, so that the planar heating element 1 is easily deformed by the external force. .

  In addition, the slit 14 of this Embodiment is applicable also in the planar heating element 1 of Embodiment 1-6, and has the same effect.

  The planar heating element according to the present invention has a simple structure, is particularly excellent in PTC characteristics, and has flame retardancy. Since this planar heating element can be mounted on the surface shape of an appliance having, for example, a continuous curved surface or a combination of flat surfaces, an automobile floor, a handle, and other electric floor heating that requires heating as a heater for heating, etc. Applicable to any apparatus. In addition, since the productivity is excellent and the cost can be reduced, the application range of applied products is expanded.

(A) is a top view which shows the planar heating element in Embodiment 1 of this invention, (b) is sectional drawing of the same planar heating element (A) is a side view which shows the seat of the motor vehicle which attached the planar heating element in Embodiment 1 of this invention, (b) is the same front view (A) is a top view which shows the planar heating element in Embodiment 2 of this invention, (b) is sectional drawing of the same planar heating element (A) is a top view which shows the planar heating element in Embodiment 3 of this invention, (b) is XY sectional drawing of (a). (A) is a top view which shows the planar heating element in Embodiment 4 of this invention, (b) is XY sectional drawing of (a). (A) is a top view which shows the planar heating element in Embodiment 5 of this invention, (b) is XY sectional drawing of (a). (A) is a top view which shows the planar heating element in Embodiment 6 of this invention, (b) is XY sectional drawing of (a). (A) is a top view which shows the planar heating element in Embodiment 7 of this invention, (b) is XY sectional drawing of (a). (A) is a top view of the conventional planar heating element, (b) is an XY sectional view of (a). Sectional drawing which shows schematic structure of an example of the preparation apparatus of the conventional planar heating element Sectional view of another conventional sheet heating element

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Planar heating element 2 Electrically insulating base material 5 Polymer resistor

Claims (12)

A planar heating element comprising a polymer resistor, wherein the main component comprises a resin composition cross-linked via a reactive resin and a conductor, and the conductor is tungsten or a tungsten compound. An electrically insulating substrate, at least one pair of electrodes disposed on the electrically insulating substrate, and electrically connected to the pair of electrodes, and the main component is cross-linked through a reactive resin A planar heating element comprising a polymer resistor, the resin composition comprising a resin composition and a conductor, wherein the conductor is tungsten or a tungsten compound. The planar heating element according to claim 1 or 2, wherein the conductor is tungsten carbide. The planar heating element according to claim 1 or 2, wherein the resin composition comprises a reactive resin that exhibits at least PTC characteristics and a reactive resin. The resin composition comprises a reactive resin having a main component containing at least one functional group of a carboxyl group, a carbonyl group, a hydroxyl group, an ester group, a vinyl group, an amino group, an oxazoline group, and a maleic anhydride group; The planar heating element according to claim 1 or 2, comprising a reactive resin containing at least one functional group of an epoxy group, an oxazoline group, and a maleic anhydride group different from the functional group of the reactive resin. The planar heating element according to claim 1, wherein a thermoplastic elastomer is contained in the resin composition. The planar heating element according to claim 6, wherein the thermoplastic elastomer is made of at least one of olefin, styrene, urethane, and polyester. The planar heating element according to claim 1 or 2, wherein the polymer resistor is composed of a flexible sheet or film. The planar heating element according to claim 2, wherein the electrode is at least one type of line electrode of a metal conductor or a metal braided conductor. The planar heating element according to claim 2, wherein the electrically insulating substrate is composed of at least one of a woven fabric and a nonwoven fabric. A seat device for an automobile in which the planar heating element according to any one of claims 1 to 10 is mounted for heating. A steering wheel device for an automobile on which the planar heating element according to any one of claims 1 to 10 is mounted for heating.