JP2006216476A - Polymer heating element - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polymer heating element high in durability, safety, and chemical resistance. <P>SOLUTION: This polymer heating element is provided with: a pair of electrodes 3 sandwiched between a base-side resin film 2 and a cover-side resin film 5; and a polymer resistive element 4 formed between the pair of electrodes. The polymer heating element is characterized by that the base-side resin film 2 and/or the cover-side resin film contains a resin constituent comprising one kind out of homopolypropylene, random copolypropylene and block copolypropylene. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a polymer heating element using Joule heat of a polymer resistor, and more particularly to a polymer heating element having high durability, safety and chemical resistance.

  Conventionally, many heater units using PTC characteristics have been used. The PTC characteristic is based on a resistance temperature characteristic (which means an abbreviation of English Positive Temperature Coefficient which means a positive resistance temperature characteristic) in which the resistance value increases with a temperature rise, and the resistance value rapidly increases when reaching a certain temperature. A polymer resistor that exhibits a self-temperature control function and in which a conductive material is dispersed in a crystalline polymer is widely known. The principle is that due to the rapid volume expansion when the crystalline polymer is converted from crystalline to amorphous, the average particle spacing of the conductive material dispersed therein rapidly increases. The probability that the current path is broken increases, and as a result, the resistance value also increases. The heater unit based on the above principle is known as an advantageous device because it has a self-temperature control function, so there is no need to provide a safety function and the number of parts can be reduced. ing.

  As shown in FIG. 6, these configurations are electrodes obtained by printing or applying a conductive ink composition on a base material 33 having a function as a housing structure such as a ceramic or an insulating metal plate. 3 and a resistor 4 obtained by printing or applying a resistor ink composition at a position to which power is supplied, and a cover material 34 covering the electrode 3 and the resistor 4. Form. Further, a heat-fusible resin 35 such as polyethylene is bonded in advance to the inside of the base material 33 and the cover material 34, and the base material 33 and the cover material 34 are bonded to each other by heating and pressurizing. The heating element can be easily configured. 6A is a plan view of the heating element, and FIG. 6B is a cross-sectional view taken along line xy of FIG. 6A. Since the comb-shaped electrode 3 and the resistor 4 are isolated from the outside by the base material 33, the cover material 34, or the heat-fusible resin 35, long-term reliability is imparted.

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 applied with mechanical stress such as bending, but was used by being attached to the back of the mirror and fixed.
JP 2002-371699 A

  However, since the conventional heating element uses a polyester film as a base material and a covering material, it is damaged when bent, and thus cannot be applied to such applications. Furthermore, in addition to the lack of flexibility, due to the lack of stretchability, attention should be paid not to impair the seating feeling of a person such as a seat heater as a heating element that requires these flexibility and stretchability. It could not be applied to the necessary products.

  Another object of the present invention is to provide a polymer heating element having high durability, safety, and chemical resistance that is effective even when these flexible substrates are used, and a method for producing the heating element. Thus, the inventors have found that it becomes more effective by examining the composition, configuration, and manufacturing method of a resin film having a role of protecting electrodes and resistors.

  The polymer heating element of the present invention for solving the conventional problems includes a pair of electrodes sandwiched between a base-side resin film and a cover-side resin film, and a resistor formed between the pair of electrodes. And at least one of the base-side resin film and the cover-side resin film has a resin component made of any one of homopolypropylene, random copolypropylene, and block copolypropylene.

  Although not particularly limited in the present invention, it is effective for a polymer heating element using a flexible substrate. The definition of flexibility means that even if a shape change occurs due to moderate mechanical stress such as bending, it means that it is not affected by the characteristics and maintains the durability ability, and the shape cannot be changed. Items other than those whose performance deteriorates due to changes in shape are subject to flexibility.

  Polypropylene (PP) can be classified into isotactic polypropylene (IPP), syndiotactic polypropylene (SPP), and atactic polypropylene (APP) based on the stereoregularity based on the arrangement of methyl groups protruding from the side chain. Although it is possible, IPP is mainly used as an industrial material. These are mainly synthesized using Ziegler-Natta catalysts, and are roughly classified into homopolymers (homopolypropylene, homoPP), random copolymers (random copolypropylene, random coPP), block copolymers (blockcopolypropylene, blockcoPP). Three types are obtained.

  Homo PP is a polymer composed only of polypropylene and has a high crystallinity. Random co-PP contains 1 to 7 parts by weight of ethylene or butene-1 as a comonomer. Block copolymer PP usually contains 20 parts by weight or less of an ethylene propylene rubber (EPR) component, and those containing more EPR are regarded as olefin-based thermoplastic elastomers or dynamically cross-linked olefin-based thermoplastic elastomers. Resins classified as homo PP, random co PP, and block co PP are extremely resistant to organic solvents and exhibit moderate flexibility even when used as a film. It was newly found that the film can maintain the stability and satisfy the purpose.

  Although the electrodes and resistors may be printed directly on these PP resin films, the printing performance of the electrodes and resistors can be improved by modifying the film surface. In addition to these PP films, it is also possible to create a film layer by blending with a resin composition containing an elastomer component so that electrodes and resistors can be printed easily. Specific examples include resin compositions classified as olefinic thermoplastic resin elastomers, and examples thereof include ethylene, styrene, and urethane. In the case of these blend systems, the weight ratio of homo PP, random co PP, and block co PP is 50% or more, more preferably 70% or more. When it is 50% or less, the resistance to various organic solvents is often insufficient, which is not preferable.

  In the present invention, it is also possible to obtain a film by superposing a plurality of layers instead of a single layer. When producing a film having a multilayer structure in this way, at least one of the layers only needs to have a resin component consisting of any one of homo PP, random co PP, and block co PP, and the other layers are Any resin component may be used as long as the heating element operates effectively. For example, a film having an excellent chemical resistance function that has a barrier property against intruders from the outside on the outside of the film and a function for showing good adhesion of electrodes and resistors on the inside are provided. Thus, the object of the present invention can be achieved. Further, by obtaining a film having a three-layer structure from, for example, a resin composition having three different characteristics of chemical resistance, flexibility, and adhesiveness, a device satisfying long-term reliability can be obtained. At this time, the single resin component may not be a composition composed of a single component, and may be, for example, a blended product for exhibiting characteristics specific to each resin. Since each layer bonded in the form of a film exhibits a function corresponding to the characteristics of these resins, it is possible to express the required characteristics more easily than when a uniform resin composition is obtained by kneading or the like. In particular, it has been found in the present invention that good chemical resistance can be imparted by using a resin component composed of any one of homo-PP, random-co PP, and block-co PP.

  As a method for producing a film in the present invention, in addition to a method of extruding a homogeneous melt from a die into a film, a method of joining films extruded from a plurality of dies into a multilayer film, an inflation method is used. Examples thereof include a method for producing a film in a balloon shape and a method for producing a flat film using a roll or the like, and any of these methods may be used. As for the number of layers, the outer side of a film made of a specific resin component may have a three-layer structure in which the outside is sandwiched with a resin having a different composition, or a two-layer structure in which two sheets are bonded together. It does not matter. Of course, it may have a multilayer structure of four or more layers.

  As the definition of the film in the present invention, a film having a thickness of less than 0.2 mm is shown as in the description of JIS K6745, and a case of 0.1 mm or less is more preferable.

  Specific examples of the apparatus used include a sheet extrusion molding apparatus, an inflation film extrusion molding apparatus, and a flat film molding apparatus, and may have an extrusion port number capable of producing a multilayer film.

  The polymer heating element may be configured to be sandwiched only between resin films, and has both the resin film and a protective member having flexibility such as woven fabric or nonwoven fabric. Also good. The polymer heating element only needs to have a resin film that covers the electrode and the polymer resistor, which are the minimum functions of the heating element. Generally, since it is difficult to maintain the strength at the time of processing only with a resin film, a release paper is often used only at the time of processing, or a film is often stuck on a thin nonwoven fabric.

  Moreover, in this invention, when using flexible members, such as a nonwoven fabric, as a protective member of these resin films, it has the resin component which consists of any one of homo PP, random co PP, and block co PP further outside them The use of a film is more preferable because it can improve the barrier performance against intruders from the outside, such as water and chemicals. Of course, these films may be a single layer or a multilayer structure.

  Moreover, the protective member and the resin film may have flame retardancy. As the definition of flame retardancy, there are various HB grades, V0 grades, and the like depending on the standard, but those with improved combustibility compared to those not prescribed for flame retardancy may be used. Although the heating element shown in the present invention may be handled as a final product as it is, the heating element is often used by being incorporated in the product. Therefore, when a resin base material such as cushioning material or urethane mat is used as a cover for the heating element, the heating element itself can be used alone if it is designed to satisfy the flame resistance required for the final product. It does not have to meet the flame retardant standard. Naturally, it is more preferable if the heating element itself exhibits flame retardancy that satisfies the standard value required for each product and clears various conditions such as processability and cost conditions.

  With these configurations, it is possible to provide a configuration with flame retardancy using materials mainly composed of polymers such as resins and non-woven fabrics, so that the final form will be expanded to flexible products that require flame retardant specifications. It becomes easy.

  Since the polymer heating element of the present invention can provide a device having high durability, safety, and chemical resistance for a heating element made of a resin or fiber base, the conventional configuration and composition Thus, the limited applications can be expanded at once, and products with excellent mass productivity can be provided at low cost.

  A first invention is a polymer heating element comprising a pair of electrodes sandwiched between a base side resin film and a cover side resin film, and a resistor formed between the pair of electrodes, wherein the base side At least one of the resin film and the cover-side resin film has a resin component composed of any one of homopolypropylene, random copolypropylene, and block copolypropylene, and has a high durability and high chemical resistance polymer type heat generation. Can provide the body.

  2nd invention consists of a 2 or more types of multilayer structure from which at least 1 differs among a base side resin film and a cover side resin film, and one layer has any one of a homopolypropylene, a random copolypropylene, and a block copolypropylene. It is a film layer and can provide a highly reliable heating element.

  According to the third aspect of the present invention, at least one outer surface of the base-side resin film and the cover-side resin film is covered with a protective member, thereby providing a base material having excellent flexibility.

  According to a fourth aspect of the present invention, there is provided a flexible polymer excellent in reliability and chemical resistance by providing a barrier layer having a resin component composed of any one of homopolypropylene, random copolypropylene and block copolypropylene on the outer surface of the protective member. A heating element can be provided.

  5th invention is a woven fabric or a nonwoven fabric in which a protective member has a flame retardance, and can provide the flexible coating material with a high flame-retardant effect.

  According to the sixth invention, at least one of the base-side resin film and the cover-side resin film contains a flame retardant component, and a holding body having a high flame retardant effect can be provided.

  In the seventh invention, the flame retardant component is either a phosphorus-based flame retardant, a nitrogen-based flame retardant, or a combination thereof, and can exhibit good flame retardant performance.

  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.

(Embodiments 1, 2, 3, 4)
FIG. 1 is a schematic cutaway configuration diagram of a polymer heating element according to the first invention. FIG. 1 (a) is a plan view, and FIG. 1 (b) is a cross-sectional view taken along line xy in FIG. FIG. In FIG. 1, the structure of the heating element 1 is as follows. Reference numeral 2 denotes a base-side resin film, which is not shown in FIG. 1, but maintained flatness with a release paper for handling in subsequent processing steps.

  Homo PP (W101, Sumitomo Mitsui Polypro), Homo PP (F107DV, Mitsui Polypro), Random Co PP (F329D, Mitsui Polypro), Block Co PP (J715M, Mitsui Polypro) are used as the base side resin films, respectively. It was created. As the thickness of the film after being bonded to the release paper, a film having a thickness of 50 to 60 microns could be obtained.

  A pair of comb-shaped electrodes 3 is printed and dried by silver paste on the film formed as the base-side resin film 2, and a polymer resistor is printed and dried by a polymer resistor ink at a position fed by the electrodes 3. 4 was produced. The polymer resistor has PTC characteristics and is produced so that the heat generation temperature is about 45 ° C. The polymer resistor ink was prepared by combining several kinds of ethylene vinyl acetate copolymers, kneading and cross-linking carbon black, and using acrylonitrile butyl rubber as a binder as an ink with a solvent.

  The cover-side resin film 5 was the same as the base-side resin film 2 and was bonded to the electrode 3 and the polymer resistor 4 described above to produce the heating element 1.

  As an evaluation of chemical resistance characteristics, an aliphatic mineral oil (nonpolar solvent) was dropped on a heating element, and changes in PTC resistance characteristics were observed after standing at room temperature for 48 hours. The results are shown in Table 1.

  In the polymer heating element thus obtained, no defects are seen in the cover-side resin film and the base-side resin film, and as a result of the chemical resistance evaluation, the rate of change in resistance characteristics is extremely low, and the durability is high. Moreover, it turned out that it fully satisfies safety | security.

(Embodiments 5 and 6)
In the embodiment of the second invention, a base side resin film having a two-layer structure composed of two types of resin components was produced. A schematic view of the multilayer sheet extrusion molding apparatus is shown in FIG. In FIG. 2, the structure of the multilayer sheet extrusion molding apparatus 6 is as follows. Reference numerals 7, 8, and 9 denote first, second, and third extruders, respectively, each having a hopper. The resin charged in the hopper is extruded while being kneaded, passes through the die 10, and the film 11 is formed. And is wound up by the winder 12. This time, homo PP (W101, Sumitomo Mitsui Polypro) is used for the hopper of the first extruder 7, and a thermoplastic resin (for example, ethylene and ethylene) is used for the hopper of the second extruder 8 to develop heat resistance and adhesiveness. A polymerization type TPO obtained by directly reacting propylene was blended with a polyethylene resin containing a maleic anhydride component in a ratio of 7: 3) to obtain a film having two layers. As the thickness of the film after bonding, a film having a thickness of 50-60 microns could be obtained. Of course, it is possible to obtain a film composed of three layers by charging a different resin into the third extruder 9 and discharging it from the die 10. First, here, the first extruder 7 and the second extruder are used. A film was prepared using two of the eight.

  A pair of comb-shaped electrodes 3 are printed and dried on the two-layer film formed as the base-side resin film 2 by polymer paste printing and drying. Resistor 4 was produced. The polymer resistor has PTC characteristics and is produced so that the heat generation temperature is about 45 ° C. The polymer resistor ink was prepared by combining several kinds of ethylene vinyl acetate copolymers, kneading and cross-linking carbon black, and using acrylonitrile butyl rubber as a binder as an ink with a solvent.

  The cover-side resin film 5 is the same resin composition as the base-side resin film 2, and is a multilayer film composed of two layers obtained by the multilayer sheet extrusion method described above. This was bonded to the electrode 3 and polymer resistor 4 described above to produce a heating element 1.

  As in Embodiments 1 to 4, as an evaluation of chemical resistance characteristics, an aliphatic mineral oil (non-polar solvent) was dropped on a heating element, and the change in PTC resistance characteristics after standing at room temperature for 48 hours was observed. The state was observed. The results are shown in (Table 2). Embodiment 5 is a case where a film made of a thermoplastic resin exhibiting adhesiveness is disposed on the electrode surface side, while Embodiment 6 is the opposite, and a film made of homo PP is disposed on the electrode surface side for evaluation. went.

  In the polymer heating element thus obtained, there are no defects such as pinholes in the cover-side resin film and the base-side resin film, and the resistance change rate is extremely low as a result of chemical resistance evaluation. It has been found that it has high performance and sufficiently satisfies safety.

(Embodiment 7)
In the seventh embodiment, a multilayer film composed of two layers of different resin components was obtained in the same manner as in the fifth and sixth embodiments. The first hopper 7 has a hopper of random co-PP (F329D, Mitsui Polypro) and a thermoplastic urethane elastomer in a weight ratio of 7: 3. The hopper of the second extruder 8 has contact characteristics with electrodes and resistors. An olefin-based adhesive resin (for example, a polyethylene-based resin containing a maleic anhydride component) was added, and a polymer heating element was prepared by using a total of two kneaders. At this time, a film thickness of 50-60 microns could be obtained after bonding.

  In the polymer heating element thus obtained, the cover side resin film and the base side resin film are free from defects such as pinholes, have excellent chemical resistance, high durability, and sufficient safety. It was found that it was satisfying.

(Embodiment 8)
In order to obtain the polymer heating element in the second invention, a film having the same resin component as that used in Embodiment 7 was prepared using the multilayer blown film extrusion molding apparatus shown in FIG. The configuration of the inflation film extrusion molding apparatus 13 in FIG. 3 is as follows. Random Co PP (F329D, Mitsui Polypro) is used for the hopper of the first extruder 14, and an olefin-based adhesive resin (for example, anhydrous) that has good contact characteristics with the electrode and the resistor for the hopper of the second extruder 15. Polyethylene resin containing maleic acid component) was added. The resin charged in each extruder is extruded while being kneaded, passes through the inflation die 16, and an inflation film 17 swelled in a balloon shape while being pulled upward is formed. These films pass through the stabilizer 18 and the pinch roll 19 and are wound up by a winder 20. The normal inflation film 17 is cut into two sheets by a slitter before being wound up by the winder 20, and then wound up. What was obtained as a convenient four-layer film consisting of two or more different resin components by pasting again with the roll part 19 was used as the base-side resin film. Thus, a film having no defects such as pinholes can be easily obtained by pasting together the films once produced as separate films. The thickness of the film after bonding this time was 50-60 microns. Of course, if it cuts with a slitter, the film which consists of two layers can be obtained, and it cannot be overemphasized that they may be used.

  A pair of comb-shaped electrodes is printed on the multilayer film formed as the base-side resin film by printing and drying, and a polymer resistor is produced by printing and drying polymer resistor ink at the position where power is supplied by the electrodes. did. The polymer resistor has PTC characteristics and is produced so that the heat generation temperature is about 45 ° C. The polymer resistor ink was prepared by combining several kinds of ethylene vinyl acetate copolymers, kneading and cross-linking carbon black, and using acrylonitrile butyl rubber as a binder as an ink with a solvent.

  The cover-side resin film is a resin composition similar to the base-side resin film, and is a multilayer film composed of a total of four layers obtained by the above-described inflation method. This was bonded to the electrode 3 and polymer resistor 4 described above to produce a heating element 1.

  In the polymer heating element thus obtained, the cover side resin film and the base side resin film are free from defects such as pinholes, are excellent in chemical resistance, have high durability, and have sufficient safety. It was found that it was satisfying.

(Embodiment 9)
In the present embodiment, a heating element was created using the same inflation film extrusion molding apparatus as in the eighth embodiment. In the present embodiment, a resin composition containing 20 parts by weight of a flame retardant is introduced into a hopper with respect to 100 parts of the olefin-based adhesive resin used in the second extruder 15, and an inflation film extrusion molding apparatus is used. A film was obtained. The used flame retardant is an ammonium phosphate flame retardant having a phosphorus content of about 20 parts by weight and a nitrogen content of about 19 parts by weight. Depending on the kneading ability of the second extruder 15 used at this time, pellets in which the flame retardant is kneaded in advance may be prepared by another apparatus. When the second extruder 15 has a twin screw, a mixture of a resin and a flame retardant can generally be put into the hopper as it is, so that if such an apparatus can be used, it is possible to save time and thus more effective. It is considered a means.

  Evaluation of the flame retardant standard for automobiles (FMVSS 302) with this configuration confirmed that the combustion rate could be reduced to half compared to the case where no flame retardant was used in the flexible carrier. Further, the flexibility of the heating element was not impaired even when flame retardancy was imparted, and the flexibility and flame retardancy were satisfied. The chemical resistance was also observed in the same manner, and a heating element with good durability could be produced.

(Embodiment 10)
FIG. 4 is a schematic cutaway configuration diagram of the polymer heating element according to the third aspect of the present invention. FIG. 4 (a) is a plan view, and FIG. 4 (b) is an xy position cross section of FIG. FIG.

  In FIG. 4, the structure of the heating element 21 is as follows. The base holding body and the cover holding body in the present invention are cases in which a resin film that covers an electrode or a polymer resistor and a protective member that covers the resin film are used. A case where both the protective member and the protective member are flame-retardant treated will be described specifically.

The protective member 22 on the base side includes a spun lace (weight per unit area: 40 g / m ² ) formed from a polyester fiber (made by Toyobo Co., Ltd.) copolymerized with a flame retardant, and a direction for regulating elongation (the length of the main electrode of the electrode A spunbond (60 g / m ² basis weight) produced by thermal bonding of polyester straight fibers (Nisseki Plast Co., Ltd., basis weight 20 g / m ² ) arranged in the direction).

  The resin film 23 on the base side has the same resin composition as in the ninth embodiment, and comprises 20 parts by weight of a flame retardant and 0.3 parts by weight of Teflon (registered trademark) fine powder as a flame retardant aid. Using an inflation film extrusion molding apparatus indicated by 3, a thickness of 50 to 60 microns was obtained. The base-side resin film 23 is bonded to the base-side protective member 22 to form an integrated base holder. A pair of comb-shaped electrodes 3 are printed on the base-side protective member 22 and the base-side resin film 23 by printing and drying, and a position where power is supplied by the electrodes 3 is printed and dried by polymer resistor ink. A molecular resistor 4 was produced. The polymer resistor has PTC characteristics and is produced so that the heat generation temperature is about 45 ° C. The polymer resistor ink was prepared by combining several kinds of ethylene vinyl acetate copolymers, kneading and cross-linking carbon black, and using acrylonitrile butyl rubber as a binder as an ink with a solvent.

The cover-side resin film 24 is a film prepared in the same manner as the base-side resin film 23, and is bonded to the cover-side protection member 25. The protective member 25 on the cover side was a needle punch (weight per unit area: 150 g / m ² ) made of a flame retardant impregnated polyester obtained by impregnating and drying a liquid flame retardant. The heating element 21 was produced by sealing the electrode 3 and the polymer resistor 4 using a laminate in which the cover-side resin film 24 and the cover-side protection member 25 were bonded together in advance.

  With this configuration, an evaluation of the flame retardant standard for automobiles (FMVSS302) was performed, and nonflammability was confirmed (horizontal arrangement, ignition from the end face, combustion stopped without reaching 38 mm mark). Further, the flexibility of the heating element 21 was not impaired, and the flexibility and flame retardancy were satisfied.

  In this embodiment, the flame retardancy ratio of the resin film is the same flame retardant content and the same flame retardant both in the upper and lower sides, but the amount and the flame retardant species do not have to be the same, and what ratio is used. May be. These flame retardant ratios are often determined by mass production processability when processing a heating element and cost at the time of mass production. Further, in the present embodiment, the case where the upper and lower resin films are subjected to the flame retardant treatment is described. However, only one of the resin films may have a flame retardant in a form according to the final product.

(Embodiment 11)
FIG. 5 is a schematic cutaway configuration diagram of the polymer heating element according to the fourth aspect of the present invention. FIG. 5 (a) is a plan view, and FIG. 5 (b) is a cross-sectional view taken along line xy in FIG. FIG.

  In FIG. 5, the structure of the heating element 26 is as follows. The base holding body and the cover holding body in the present invention are cases where a resin film covering the electrode or the polymer resistor and a protective member covering the resin film are used, respectively, and further on the outer surface of the base-side protective member. Has a film to be a barrier layer. As the eleventh embodiment, a case where a barrier layer made of a homo PP resin is provided will be specifically described.

  The base-side protection member 28 and the cover-side protection member 31 are both the flame retardant-containing nonwoven fabric used in the tenth embodiment.

  By using a sheet extrusion apparatus having one extruder, a resin film made of a homo PP component is bonded to both sides of the protective member 28 on the base side through two steps, whereby the barrier layer 27 on the base side is bonded. A base-side resin film 29 was prepared. Each film thickness is about 50 microns, and the homo PP used is W101 (Sumitomo Mitsui Polypro). On the other hand, the resin film 30 on the cover side is the same film as used in Embodiment 8, and is bonded to the protective member 31 on the cover side.

  A pair of comb-like electrodes 3 and electrodes are formed by printing and drying a silver paste on the resin film 29 of the base holding body composed of the base-side barrier layer 27, the base-side protective member 28, and the base-side resin film 29. The polymer resistor 4 was produced by printing and drying the polymer resistor ink at the position where the power was fed by 3. The polymer resistor has PTC characteristics and is produced so that the heat generation temperature is about 45 ° C. The polymer resistor ink was prepared by combining several kinds of ethylene vinyl acetate copolymers, kneading and cross-linking carbon black, and using acrylonitrile butyl rubber as a binder as an ink with a solvent.

  Thereafter, the cover-side resin film 30 side attached to the cover-side protection member 31 was bonded to the above-described electrode and polymer resistor to produce a heating element.

  In the polymer heating element thus obtained, the cover side resin film and the base side resin film are free from defects such as pinholes, have excellent chemical resistance, high durability, and sufficient safety. It was found that it was satisfying.

  As described above, since the heating element according to the present invention can provide a highly safe heating element having high reliability such as flexibility and chemical resistance, it can be applied to seat heaters and handle heaters. Become.

(A) Notch top view which shows the structure of the heat generating body in Embodiment 1, 2, 3, 4 of this invention (b) xy position sectional drawing of (a) Schematic of multilayer sheet extrusion apparatus for producing multilayer films in Embodiments 5 and 6 of the present invention Schematic of a multilayer blown film extrusion molding apparatus for producing a multilayer film in Embodiment 8 of the present invention (A) Cutaway plan view showing the configuration of the heating element according to the tenth embodiment of the present invention (b) xy position sectional view of (a) (A) Cutaway plan view showing the configuration of the heating element in Embodiment 11 of the present invention (b) xy position sectional view of (a) (A) Plan view showing a conventional heating element (b) xy position sectional view of (a)

Explanation of symbols

1, 2, 26, 32 Heating element 2, 23, 29 Resin film on base side 3 Electrode 4 Polymer resistor 5, 24, 30 Resin film on cover side 22, 28 Base side protection member 25, 31 Cover side Protective member 27 Base-side barrier layer 33 Base material 34 Cover material 35 Heat-sealable resin

Claims (7)

In a polymer heating element comprising a pair of electrodes sandwiched between a base side resin film and a cover side resin film, and a resistor formed between the pair of electrodes, the base side resin film and the cover side A polymer heating element, wherein at least one of the resin films has a resin component of any one of homopolypropylene, random copolypropylene, and block copolypropylene. At least one of the base-side resin film and the cover-side resin film is composed of two or more kinds of multilayer structures, and at least one of the multilayer structures has any one of homopolypropylene, random copolypropylene, and block copolypropylene. The polymer heating element according to claim 1, which is a film layer. The polymer heating element according to claim 1 or 2, wherein at least one outer surface of the base-side resin film and the cover-side resin film is covered with a protective member. The polymer heating element according to claim 3, wherein a barrier layer having a resin component made of any one of homopolypropylene, random copolypropylene, and block copolypropylene is provided on the outer surface of the protective member. The polymer heating element according to claim 3 or 4, wherein the protective member is a woven or non-woven fabric having flame retardancy. The polymer heating element according to any one of claims 1 to 5, wherein at least one of the base-side resin film and the cover-side resin film contains a flame retardant component. The polymer heating element according to any one of claims 1 to 6, wherein the flame retardant component is a phosphorous flame retardant, a nitrogen flame retardant, or a combination thereof.

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