JP2006344548A - Heating element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a high-reliability heating element having flexibility and extensibility. <P>SOLUTION: This heating element includes: a base non-woven fabric 2 having flexibility; a base film 5 with a barrier property stuck to the base non-woven fabric 2 and having flexibility and extensibility; electrodes 6 formed on the base film 5 with a barrier property by printing and drying; a polymer resistor 7 supplied with power by the electrodes 6; a cover non-woven fabric 9 having flexibility; and a cover film 8 with a barrier property having flexibility and extensibility, stuck to the cover non-woven fabric 9, and having adhesiveness to the electrodes 6, the polymer resistor 7 and the base film 5 with a barrier property. The heating element is composed by sealing the electrodes 6 and the polymer resistor 7 between the base film 5 with a barrier property and the cover film 8 with a barrier property by heat sealing. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a structure of a heating element using Joule heat of a polymer resistor, and can provide a heating element having flexibility and stretchability and high reliability.

  Conventionally, this type of heating element is obtained by printing and drying a conductive paste on an electrically insulating substrate 50 such as a polyester film having a thickness of about 100 micrometers as shown in FIG. A pair of comb-shaped electrodes 51 and 52 and a polymer resistor 53 obtained by printing and drying a polymer resistor ink are provided at positions where power is fed by the pair of comb-shaped electrodes 51 and 52, and a covering material 54 made of the same material as the base material 50 is further provided. The comb-shaped electrodes 51 and 52 and the polymer resistor 53 are covered and protected. When a polyester film is used as the base material 50 and the covering material 54, for example, a polyethylene-based heat-fusible resin 55 is bonded to the covering material 54 in advance, and the base material 50 and the covering material 54 are pressed by heating. Are bonded via a heat-fusible resin 55.

  4A is a partially cutaway plan view of the heating element, and FIG. 4B is a cross-sectional view taken along the line xy of FIG. 4A. Thereby, the comb-shaped electrodes 51 and 52 and the polymer resistor 53 are isolated from the outside world and given long-term reliability. As the hot pressurizing means, a laminator provided with two hot rolls is used.

  Conventionally, examples in which a polymer resistor is formed by printing and used as a heating element include an automobile door mirror and a sink mirror for removing dew and frost. The usage pattern was not subjected to mechanical stress such as bending, but was used by being attached to the back of the mirror and fixed. Further, as a safety measure, a thermal fuse, a thermostat, or the like is attached to a portion representing the heat generation temperature of the planar heating element. In practice, a terminal is required for power supply, but this is not shown.

  The polymer resistor ink for forming the polymer resistor 53 includes a base polymer and a conductive material such as carbon black, metal powder, and graphite dispersed in a solvent. In particular, ethylene vinyl acetate is used as the base polymer. Many of them have PTC characteristics using a crystalline resin such as a polymer or low density polyethylene (for example, see Patent Documents 1, 2, and 3). As long as it has PTC characteristics, it is also used as an overcurrent protection element in addition to the heating element described above.

The PTC characteristic is a resistance temperature characteristic in which the resistance value increases as the temperature rises, and when the temperature reaches a certain temperature, the resistance value increases rapidly (takes the acronym for Positive Temperature Coefficient in English, meaning that the resistance has a positive temperature coefficient). The polymer resistor 53 having PTC characteristics can provide a heating element having a self-temperature adjusting function.
Japanese Patent Laid-Open No. 56-13689 JP-A-6-96843 JP-A-8-120182

However, in the conventional heating element, since the polyester film is used as the base material 50 and the covering material 54, the film is poor in flexibility, and when folded, it makes a sound or breaks. Is not applicable. Of course, when the thickness of the polyester film is reduced, the flexibility is increased, but the mechanical strength is decreased. In terms of stretchability,
Polyester is poor in elasticity because it is determined by the physical properties of the material itself. Therefore, these heating elements that require flexibility and stretchability, such as car seat heaters, are deformed by fitting to the human body, i.e., they do not impair the user's feeling of sitting and pay close attention to safety. It was not possible to apply it to the product.

  For this reason, it is conceivable to use a flexible and stretchable elastomer such as polyester as a film, such as a polyester, such as a thermoplastic, as a film. The fact is that it has not yet been realized. Durability to the operating environment means that the elastomer lacks barrier properties against gases such as water vapor, aqueous solutions, or various solvents and oils in a high-temperature and high-humidity atmosphere. This is thought to be due to the above.

  In general, conductive paste and polymer resistor ink contain an organic solvent. Therefore, if a base material with poor barrier properties is used, the conductive paste or polymer resistance swells or dissolves in the organic solvent. It affects the body ink itself. In addition, it is possible to pass through the base material or the coating material by contacting with various liquids such as various solvents and oil entering from the outside, or to swell the base material and the coating material, and to place and hold between the films. It affects the molecular resistor and its resistance value changes greatly. As mentioned above, considering that the PTC characteristics are attributable to slight thermal changes in the specific volume of the crystalline resin, even the slight swelling caused by various liquids on the substrate has a large effect on the resistance value of the polymer resistor. You can easily imagine doing it.

  SUMMARY OF THE INVENTION The present invention solves the above-described conventional problems, and an object thereof is to provide a heating element using a polymer resistor that has flexibility and stretchability and has high reliability.

  In order to solve the conventional problems, a heating element of the present invention includes a base nonwoven fabric having flexibility, a barrier / base film having flexibility / stretchability bonded to the base nonwoven fabric, and the barrier base film. An electrode formed on the electrode, a polymer resistor fed by the electrode, a cover nonwoven fabric having flexibility, and an adhesive property to the electrode, polymer resistor, and barrier base film bonded to the cover nonwoven fabric And a barrier cover film having flexibility and stretchability, and the electrode and the polymer resistor are hermetically sealed between the barrier base film and the barrier cover film by heat fusion.

  The heating element of the present invention can be applied to applications that require flexibility, elasticity, and high reliability, for example, car seat heaters and handle heaters.

  According to a first aspect of the present invention, there is provided a base nonwoven fabric having flexibility, a barrier base film having flexibility / stretchability bonded to the base nonwoven fabric, an electrode formed on the barrier base film, and power feeding by the electrode. The polymer resistor, the cover nonwoven fabric having flexibility, and the barrier nonwoven fabric that is bonded to the cover nonwoven fabric and has adhesiveness with the electrode, polymer resistor, and barrier base film, and has flexibility and stretchability A cover film, and the electrode and the polymer resistor are sealed by thermal fusion between the barrier base film and the barrier cover film.

  With this configuration, it is possible to prevent the influence of the heating element on the polymer resistor by disposing a barrier film that prevents the penetration of various liquids and gases.

In the second invention, the barrier base film is compatible with the barrier resin, the flexible / stretchable resin incompatible with the barrier resin, and the flexible / stretchable resin. And a reactive resin.

  With this configuration, the flexible / stretchable resin is dispersed in an island shape in the barrier resin, and at the interface, the barrier resin and the reactive resin are bonded by reaction to provide a base film having a high barrier property.

  In the third invention, the barrier base film is formed by T-die extrusion of a kneaded material composed of a flexible / stretchable resin and a reactive resin, and the barrier resin.

  With this configuration, a film is formed while adjusting the reactivity of the reactive resin dispersed in the flexible / stretchable resin and the barrier resin, and the base nonwoven fabric is removed from the die of the extruder without using an adhesive. The barrier base film can be directly fused to the base nonwoven fabric when heated.

  The fourth invention is an ethylene / vinyl alcohol copolymer, a saponified ethylene / vinyl acetate copolymer, a polybutylene terephthalate, a polyethylene terephthalate, a polyethylene terephthalate copolymer, a polypropylene, a polypropylene copolymer, a polyamide as a barrier resin. Mold resins are used alone or in combination.

  With this configuration, it is possible to provide a highly barrier resin made of a film having a high barrier property.

  The fifth invention is an olefin-based thermoplastic elastomer, a styrene-based thermoplastic elastomer, a urethane-based thermoplastic elastomer, a polyamide-based thermoplastic elastomer, a polyester-based thermoplastic elastomer, a polyester copolymer alone, as a flexible / stretchable resin, Or they are used in combination.

  With this configuration, it is possible to obtain a flexible and stretchable resin that has flexibility and stretchability and is highly manufactured.

  In the sixth invention, an epoxy group-containing resin, a carboxylic acid group-containing resin, an oxazoline group-containing resin, or a maleic anhydride group-containing resin is used alone or in combination as a reactive resin.

  With this structure, it is possible to obtain a highly reactive resin made of a film while reacting to form a molecular bond (crosslinking).

  7th invention mix | blends the reactive resin which reacts with reactive resin as needed in barrier resin.

  With this configuration, even when the barrier resin is poor in reactivity, the reactive resin can be interposed to provide a barrier film by reaction between the reactive resin and the reactive resin.

  The eighth invention relates to a reactive resin and a reactive resin, an epoxy group-containing resin and a carboxylic acid group-containing resin, an epoxy group-containing resin and a maleic anhydride group-containing resin, an oxazoline group-containing resin and a carboxylic acid group-containing resin, This is a combination of either an oxazoline group-containing resin and a maleic anhydride group-containing resin.

  With this configuration, a barrier film having high reactivity and high barrier properties can be provided.

  According to a ninth aspect of the present invention, there is provided a low melting point resin in which the barrier cover film has a melting point lower than that of the barrier base film, a flexible / stretchable resin incompatible with the low melting point resin, and the flexible / stretchable resin It consists of a reactive resin that is compatible and reacts with the low melting point resin.

  With this configuration, the flexible and stretchable resin is dispersed in an island shape in the low melting point resin, and at the interface, the low melting point resin and the flexible and stretchable resin are combined with the reactive resin to provide a high film forming property. A barrier cover film can be provided.

  According to a tenth aspect of the present invention, an epoxy group-containing resin and a carboxylic acid group-containing resin, an epoxy group-containing resin and a maleic anhydride group-containing resin, an oxazoline group-containing resin, a carboxylic acid group-containing resin, and an oxazoline are used. The combination is any combination of a group-containing resin and a maleic anhydride group-containing resin.

  With this configuration, it is possible to provide a combination of a low-melting-point resin and a reactive resin that are highly reactive and molecularly bond.

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

(Embodiment)
FIG. 1 is a schematic configuration diagram of a heating element according to an embodiment of the present invention. FIG. 1A is a partially cutaway plan view, and FIG. 1B is an xy position of FIG. It is sectional drawing.

In FIG. 1, the structure of the heating element 1 is as follows. Reference numeral 2 denotes a flexible base non-woven fabric, a spunlace 3 (weight per unit area: 40 g / m ² ) formed from a polyester fiber and a polyester straight fiber 4 arranged in a direction in which elongation is regulated (longitudinal direction of the main electrode of the electrode). Span bond (50 g / m ² basis weight) produced by bonding (trade name Milife: Nippon Oil Plast Co., Ltd., basis weight 10 g / m ² ) with a thermal dot (thermal bond) with a smaller diameter than usual. is there. 5 is a barrier base film having flexibility and stretchability, and has a barrier property having resistance to various liquids (water, oil, solvent) such as an ethylene / vinyl alcohol copolymer (Eval H101B, manufactured by Kuraray Co., Ltd.). From 50 parts of resin and 20 parts of reactive resin such as flexible and stretchable resin such as styrene thermoplastic elastomer (Tuftec H1062, manufactured by Asahi Kasei Co., Ltd.) and epoxy group-containing resin (bond first, manufactured by Sumitomo Chemical Co., Ltd.) And is bonded to the surface of the spunlace 3 of the base nonwoven fabric 2 with a thickness of 55 microns by a T-die extrusion method. Although it is possible to produce the barrier base film 5 by other film production methods, for example, an inflation method, in that case, a process of bonding the base nonwoven fabric 2 to the base nonwoven fabric 2 with an adhesive is required. Become. Therefore, here, the T-die extrusion method is adopted.

  A pair of comb-shaped electrodes 6 is printed and dried on a barrier base film 5 thermally fused to a base nonwoven fabric by printing and drying, and a polymer resistor ink is printed and dried at a position where power is fed by the electrodes 7. Polymer resistor 7 was produced. The polymer resistor 7 has a PTC characteristic and is manufactured for a car seat so that the heat generation temperature is about 45 ° C. The polymer resistor ink was prepared by combining several types of ethylene vinyl acetate copolymers and kneading and crosslinking carbon black with them, and using acrylonitrile butyl rubber as a binder to make an ink.

8 is a barrier cover film, which is 50 parts of a low melting point resin such as carboxyl group-containing polyethylene (Nucrel N1525, manufactured by Mitsui DuPont Polychemical Co., Ltd.) and a polyamide-based thermoplastic elastomer (Uvesta XPA9044X2, manufactured by Ube Industries, Ltd.). ) And a resin composition comprising 30 parts of a reactive resin such as an epoxy group-containing resin (Bond First, manufactured by Sumitomo Chemical Co., Ltd.) and 50-60 microns by a T-die extrusion method. It is bonded to the cover nonwoven fabric 9 with a thickness of. As the cover nonwoven fabric 9, an orthogonal fiber nonwoven fabric having a weight of 6 g such as TY0303E (manufactured by Nippon Steel Plast Co., Ltd.) was used. The barrier cover film 8 and the barrier base film 5 are heat-sealed by a laminator, and the electrode 6 and the polymer resistor 7 are sealed between the barrier base film 5 and the barrier cover film 8 to heat the heating element 1. Was made. In practice, it is necessary to form a terminal portion for supplying power on the electrode 6, but it is omitted here.

  With this configuration, various liquids were dropped from the base nonwoven fabric 2 side and the cover nonwoven fabric side to observe changes in the resistance value of the polymer resistor 8, but after 300 hours, the barrier base film 5 and the barrier cover film When there is no 8, the resistance value increases by one digit, but when the barrier base film 5 or the barrier cover film 8 is provided, the resistance value change rate is within 40%, and the barrier cover film 5 and the effectiveness of the barrier cover film 8 were confirmed.

  We focused on engine oil, brake oil, and thinner as harsh liquids among various liquids such as water, drinking water, oil, and solvent during the development of the barrier base film 5 and the barrier cover film 8. . The resin composition of the barrier base film 5 and the barrier cover film 8 includes a flexible / stretchable resin and a reactive resin in addition to the barrier resin, but the reactive resin itself is a polar group having reactivity. The brake oil, which is a polar oil, was considered to have the greatest influence on the resistance value change (resistance value increase). The engine oil is assumed to be resistant because it is nonpolar oil. In addition, the presence of a flexible / stretchable resin is indispensable for the present invention in terms of imparting flexibility / stretchability, but it was assumed that the liquid easily penetrates because of its amorphous nature and weak intermolecular force. . Although thinner is a representative low boiling point solvent, it was thought that the flexible / stretchable resin easily swells and affects the resistance value of the polymer resistor 7.

  On the other hand, ethylene vinyl alcohol copolymer (EVOH), polybutylene terephthalate (PBT), nylon, polypropylene (PP), etc., such as Evar (manufactured by Kuraray Co., Ltd.), which is generally called a barrier resin, It was confirmed that it has a barrier property not only for gas but also for liquid. A common property of these barrier resins is that they have a high crystallinity, a high melting point, and a hard material. It is considered that the molecules are closely oriented and the intermolecular force is strong, which is a cause of high barrier properties.

  The purpose of imparting flexibility and stretchability, which is the main focus of the present invention, cannot be achieved with this barrier resin alone. Therefore, a flexible / stretchable resin is added to such a barrier resin to such an extent that the barrier property of the barrier resin is not lowered so much. On the other hand, from the viewpoint of film formation, it is indispensable for the barrier resin and the flexible / stretchable resin to be compatible with each other. Not only the film thickness cannot be obtained, but the film is incomplete. Therefore, when a flexible / stretchable resin having poor barrier properties and compatible with the barrier resin is used, the amount of addition is limited to about 20% or less. This is because the flexible / stretchable resin is compatible with the barrier resin and uniformly dispersed throughout, and the flexible / stretchable resin portion having poor liquid resistance is affected by the liquid and swells. In order to minimize this effect, the amount of the flexible / stretchable resin is limited. As a result, since the hardness of the barrier resin remains in the obtained barrier film, it can be improved for applications that require further flexibility and stretchability, except when the hardness is compatible. Wanted. The image figure of the resin composition was shown in FIG. 10 is a barrier resin, and 11 is a flexible / stretchable resin.

The object of the present invention is to enhance flexibility and stretchability while ensuring barrier properties. Therefore, using a barrier resin, an incompatible flexible / stretchable resin, and a reactive resin compatible with the flexible / stretchable resin, at the interface between the barrier resin and the flexible / stretchable resin, Forms a reaction product (molecular crosslink) between the reactive resin and the barrier resin to protect the periphery of the flexible / stretchable resin with poor barrier properties with the reaction product, and also has a barrier property as a whole in terms of film formation. This is solved by creating a fine and homogeneous sea-island structure with the resin as the sea and the flexible and stretchable resin as the island. FIG. 3 shows an image diagram. 12 is a barrier resin, 13 is a flexible / stretchable resin, 14 is a reactive resin, and 15 is a reaction product of the barrier resin 12 and the reactive resin 14. The feature of this configuration is that when the barrier resin and the flexible / stretchable resin are compatible, the amount of the flexible / stretchable resin is limited to about 20%, whereas the non-invention of the present invention. In a compatible system, the amount added can be increased to about 50%. The intruding liquid is basically shielded by the barrier resin, but even if a slight amount of liquid enters, the periphery of the flexible / stretchable resin is protected by a reaction product consisting of the barrier resin and the reactive resin. Therefore, the penetration of the liquid into the flexible / stretchable resin is inhibited. As a result, a flexible and stretchable barrier film can be provided.

  Next, a second embodiment will be described. The barrier base film 5 is formed on the base nonwoven fabric by T-die extrusion of a kneaded material composed of a flexible / stretchable resin and a reactive resin and the barrier resin. As a result, when the barrier resin, the flexible / stretchable resin, and the reactive resin are put into the extruder at once, the barrier resin and the reactive resin immediately start to react and take a predetermined dispersion state. However, it is difficult to obtain a mixture of a flexible / stretchable resin and a reactive resin in advance, and the reactive resin is uniformly dispersed in the flexible / stretchable resin. Is put into the extruder, the reaction between the reactive resin located on the surface layer of the flexible and stretchable resin and the barrier resin can be adjusted according to the extrusion conditions, and the barrier property base is maintained while the film forming property is maintained. A film can be made.

  Here, mention will be made of the formation of the barrier base film 5 and the barrier cover film 8 on the base nonwoven fabric 2 or the cover nonwoven fabric 9 by the T-die extrusion method. In addition to the T-die extrusion method, an inflation method and a coating method are known as film production methods. However, although the inflation method is excellent as a method for producing a thin film, since the mechanical strength of the produced film is weak as it is, the non-woven fabric is bonded to the nonwoven fabric using an adhesive or the like, for example. Although it is necessary to match, an extra bonding step is required. In addition, the coating method requires a step of drying the coating solution, and both have the disadvantage of high production costs. On the other hand, in the T-die extrusion method, the barrier property base film or the barrier property cover film that has been ejected from the die of the extruder is directly heated in one step without using an adhesive on the base nonwoven fabric or the cover nonwoven fabric. Since it can sometimes be produced by fusing to a base nonwoven fabric or a cover nonwoven fabric, a high-quality film can be produced at low cost, which is extremely important in producing the heating element of the present invention.

  Next, a third embodiment will be described. As the barrier resin, ethylene / vinyl alcohol copolymer, saponified ethylene / vinyl acetate copolymer, polybutylene terephthalate, polyethylene terephthalate, polyethylene terephthalate copolymer, polypropylene, polypropylene copolymer, polyamide type resin alone, or Used in combination. These resins are hard but have high barrier properties and film-forming properties, and are optimal as the barrier resins of the present invention.

Next, a fourth embodiment will be described. Olefin-based thermoplastic elastomer, styrene-based thermoplastic elastomer, urethane-based thermoplastic elastomer, polyamide-based thermoplastic elastomer, polyester-based thermoplastic elastomer, polyester copolymer is used alone or in combination as a flexible / stretchable resin. . It is possible to provide a flexible / stretchable resin that is incompatible with the barrier resin used and rich in flexibility / stretchability.

  Next, a fifth embodiment will be described. As the reactive resin, an epoxy group-containing resin, a carboxylic acid group-containing resin, an oxazoline group-containing resin, or a maleic anhydride group-containing resin is used alone or in combination. A reactive resin has a reactive polar group, such as an epoxy group, a maleic anhydride group, an oxazoline group, and a certain polar group, such as a hydroxyl group, an ester group, an amino group, an amide group, a carboxyl group. It means a resin that mainly chemically bonds a ring-opening addition reaction with a resin having a group. Reactive resins such as Bond First 2C (manufactured by Sumitomo Chemical Co., Ltd.) and Epofriend AT501 (manufactured by Daicel Chemical Industries, Ltd.) and carboxylic acids such as Nucleel N1525 (manufactured by Mitsui DuPont Polychemical Co., Ltd.) Group-containing resins, oxazoline group-containing resins such as Epocross RPS1005 (manufactured by Nippon Shokubai Co., Ltd.), maleic anhydride group-containing resins such as Modic APM545 (manufactured by Mitsubishi Chemical Corporation), and the like are commercially available.

  There are various combinations, but the characteristic ones are listed. Combination of ethylene / vinyl alcohol copolymer or saponified ethylene / vinyl acetate copolymer, styrene thermoplastic elastomer and epoxy group-containing resin, carboxylic acid group-containing resin or oxazoline group-containing resin, polyester-based resin (polybutylene terephthalate, Polyethylene terephthalate, polyethylene terephthalate copolymer) and olefin-based thermoplastic elastomers, styrene-based thermoplastic elastomers or urethane-based thermoplastic elastomers, and carboxylic acid group-containing resins and oxazoline group-containing resins are effective.

  Next, a sixth embodiment will be described. A reactive resin that reacts with the reactive resin is blended in the barrier resin as necessary. When a nonpolar barrier resin such as polypropylene or a polypropylene copolymer is used as the barrier resin, a reaction with the reactive resin does not occur as it is, so that it is compatible with the resin, for example, containing a maleic anhydride group Using a resin in which a reactive resin such as a resin is dispersed, this barrier resin composition and a flexible / stretchable resin composition comprising a flexible / stretchable resin and a reactive resin are put into an extruder. It can use for film forming and can produce a barrier property base film.

  Next, a seventh embodiment will be described. Reactive resin and resin to be reacted include epoxy group-containing resin and carboxylic acid group-containing resin, epoxy group-containing resin and maleic anhydride group-containing resin, oxazoline group-containing resin and carboxylic acid group-containing resin, oxazoline group-containing resin and anhydrous Any combination of maleic acid group-containing resins. Thereby, a reactive resin and a to-be-reacted resin react efficiently, and a reaction product with high barrier property can be produced.

  Next, an eighth embodiment will be described. The barrier cover film is compatible with a low melting point resin having a melting point lower than that of the barrier base film, a flexible / stretchable resin incompatible with the low melting point resin, and the flexible / stretchable resin. It was composed of a reactive resin that reacts with a melting point resin. The barrier cover film is basically produced in the same way as the barrier base film, but the difference is that the barrier base film corresponds to the printing surface of the electrode or polymer resistor, and such an ink. However, the barrier cover film has a melting point lower than that of the barrier base film and melts at a low temperature, so that an electrode, a polymer resistor, Designed to fuse to a barrier base film. With this configuration, it is possible to provide a barrier cover film having flexibility and stretchability and high barrier properties like the barrier base film.

Next, a ninth embodiment will be described. Low melting point resin and reactive resin include epoxy group-containing resin and carboxylic acid group-containing resin, epoxy group-containing resin and maleic anhydride group-containing resin, oxazoline group-containing resin and carboxylic acid group-containing resin, oxazoline group-containing resin and maleic anhydride Any combination of acid group-containing resins. With this configuration, the low-melting point resin and the reactive resin can efficiently react to generate a reactive organism having a high barrier property.

  The difference between the barrier cover film and the barrier base film is only the use of a low melting point resin, and the use of a flexible / stretchable resin, a reactive resin, and a reactive resin is the same. As the low melting point resin, polyethylene, modified polyethylene (maleic anhydride-modified polyethylene, carboxyl group-modified polyethylene, epoxy group-modified polyethylene), EVA, EEA, or EMMA can be used.

  In addition, although not mentioned in the said Example, it cannot be overemphasized that a flame retardant may be kneaded into all the structural members which comprise a heat generating body, for example, and a flame retardance may be provided.

  In the seating feeling in which the heating element of the present invention was actually mounted on a car seat, the same evaluation as the current nonwoven fabric / linear type seat heater was obtained, and it was confirmed that there was no problem. The seating feeling as a seat heater is related to flexibility, stretchability, and cushioning properties, but all of them are satisfied.

  As described above, the heating element according to the present invention can provide a highly reliable heating element that has both flexibility / stretchability and barrier properties, and thus can be applied to car seat heaters, handle heaters, and the like.

(A) Partially cutaway plan view showing the configuration of the heating element in the first embodiment of the present invention (b) Cross-sectional view of the heating element at the XY position The image figure of the barrier property base film in the 1st Embodiment of this invention The image figure of the barrier property base film in the 2nd Embodiment of this invention (A) Partially cutaway plan view showing the configuration of a conventional heating element (b) Cross-sectional view of the heating element at the XY position

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Heat generating body 2 Base nonwoven fabric 5 Barrier base film 6 Electrode 7 Polymer resistor 8 Barrier cover film 9 Cover nonwoven fabric 10, 12 Barrier resin 11, 13 Flexible / stretchable resin 14 Reactive resin 15 Reaction product

Claims (10)

A base nonwoven fabric having flexibility, a barrier base film having flexibility and stretchability bonded to the base nonwoven fabric, an electrode formed on the barrier base film, and a polymer resistor fed by the electrode And a cover nonwoven fabric having flexibility, and a barrier cover film bonded to the cover nonwoven fabric having flexibility and stretchability, and having an adhesive property with the electrode, the polymer resistor, and the barrier base film, A heating element in which the electrode and the polymer resistor are sealed by heat sealing between the barrier base film and the barrier cover film. The barrier base film comprises a barrier resin, a flexible / stretchable resin that is incompatible with the barrier resin, and a reactive resin that is compatible with the flexible / stretchable resin and reacts with the barrier resin. The heating element according to claim 1. The heating element according to claim 2, wherein the barrier base film is formed on the base non-woven fabric by T-die extrusion of a kneaded material composed of a flexible / stretchable resin and a reactive resin and the barrier resin. As the barrier resin, at least one of ethylene / vinyl alcohol copolymer, saponified ethylene / vinyl acetate copolymer, polybutylene terephthalate, polyethylene terephthalate, polyethylene terephthalate copolymer, polypropylene, polypropylene copolymer, and polyamide resin. The heating element according to claim 2 or 3, wherein one is used. As the flexible / stretchable resin, at least one of olefin-based thermoplastic elastomer, styrene-based thermoplastic elastomer, urethane-based thermoplastic elastomer, polyamide-based thermoplastic elastomer, polyester-based thermoplastic elastomer, and polyester copolymer is used. The heating element according to claim 2 or 3. The heating element according to claim 2 or 3, wherein at least one of an epoxy group-containing resin, a carboxylic acid group-containing resin, an oxazoline group-containing resin, and a maleic anhydride group-containing resin is used as the reactive resin. The heating element according to claim 4 or 6, wherein a reactive resin that reacts with the reactive resin is blended in the barrier resin as required. Reactive resin and resin to be reacted include epoxy group-containing resin and carboxylic acid group-containing resin, epoxy group-containing resin and maleic anhydride group-containing resin, oxazoline group-containing resin and carboxylic acid group-containing resin, oxazoline group-containing resin and anhydrous The heating element according to claim 7, wherein the heating element is a combination of any of maleic acid group-containing resins. The barrier cover film is compatible with a low melting point resin having a melting point lower than that of the barrier base film, a flexible / stretchable resin incompatible with the low melting point resin, and the flexible / stretchable resin. The heating element according to claim 1, comprising a reactive resin that reacts with a melting point resin. Low melting point resin and reactive resin include epoxy group-containing resin and carboxylic acid group-containing resin, epoxy group-containing resin and maleic anhydride group-containing resin, oxazoline group-containing resin and carboxylic acid group-containing resin, oxazoline group-containing resin and maleic anhydride The heating element according to claim 9, which is a combination of any of acid group-containing resins.