JPS63170903A - Heat-sensitive wire - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a heat-sensitive wire having heat-adhesive properties for use in planar heating devices such as panel heaters and electric carpets.

Conventional technology In general, this type of heat-sensitive wire is made into a unit by placing it in parallel with a cord-shaped heating wire and welding it to an adhesive film made of crystalline resin by thermocompression bonding, and then this unit is bonded to a matte material and a outer material. It is used in planar heating devices that are integrally joined by heat-compression bonding between the two. The matte and outer surfaces of planar heating devices are felt-like fibers made of needle-punched fibers, so a crystalline adhesive film is suitable for bonding them together. Therefore, in order to form a unit with this adhesive film, the material of the outermost shell of the heat-sensitive wire must be able to be welded to the crystalline resin by thermocompression bonding.

Conventional heat-sensitive wires, as proposed in Japanese Utility Model Publication No. 59-3513, include a heat-sensitive body having a negative temperature coefficient between a pair of metal conductors, an insulator covering the outer periphery of the heat-sensitive body, and this insulation. After wrapping a heat-resistant plastic film around the outside of the body, an adhesive layer that could be welded to crystalline resin was provided on the outermost shell.

Problems to be Solved by the Invention However, conventional heat-sensitive wires have the following drawbacks.

(a) If a significant concentrated load is applied, a pair of electrodes may be short-circuited.

(b) Since the insulator is partially in close contact with the heat-sensitive element, if both are of the same type of material, the heat generated during molding of the insulator will cause them to weld, making it difficult to peel off the terminals and making it difficult to remove the metal conductor. If the heat sensitive element is damaged or cut, resulting in poor workability, or if the temperature rises, plasticizers added to the heat sensitive element and additives added to improve thermistor characteristics may migrate to the insulator side. As a result, the characteristics change.

(c) Since a plastic film is wrapped around the outer circumference of the insulator in a spiral shape, it becomes stiff and reduces flexibility, making it difficult to install meanderingly and to break the planar heating device. Inferior.

(d) Since the adhesive layer is made of a crystalline resin, it becomes harder and less flexible when the temperature drops, and the number of manufacturing steps increases, resulting in high costs.

An object of the present invention is to provide a heat-sensitive wire that eliminates the above-mentioned drawbacks of conventional heat-sensitive wires.

Means for Solving the Problems In order to achieve the object, the present invention has the following configuration. In other words, the heat-sensitive wire according to the present invention comprises: a cylindrical heat-sensitive body having a negative temperature coefficient; a pair of metal electrodes arranged in parallel on the inner or outer surface of the heat-sensitive body with a separator interposed therebetween; The structure includes a heat-fusible insulator made of polyolefin thermoplastic elastomer coated on the outer circumferential side with a shield interposed therebetween.

Function The heat-sensitive wire of the present invention exhibits the following functions by having the above-described structure.

(a) By arranging a pair of metal electrodes and a separator between them on the inner or outer surface of the heat sensitive body, the metal electrodes will not short-circuit even if a weighted stress is applied.

(b) By providing a shield between the heat-sensitive body and the heat-fusible insulator, the terminals can be easily peeled off, and there is no migration of additives from the heat-sensitive body to the heat-fusible insulator.

(c) By using a polyolefin-based thermoplastic elastomer as the heat-fusible insulator, it has insulation and adhesive properties and always maintains flexibility regardless of temperature.

Example Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 shows an embodiment of the heat-sensitive wire of the present invention.
2 and 3 are a pair of metal electrodes made of copper, for example, which are spirally wound in parallel around the outer periphery of the core yarn 1;
4 is a separator made of enameled wire or heat-resistant fiber, such as polyester or aromatic polyamide, which is interposed between a pair of metal electrodes 2.3 and spirally wound in parallel around the outer circumference of the core thread 1; 5 is a core; A thermosensitive body made of, for example, a vinyl chloride resin with a surfactant added thereto, having a negative temperature coefficient and coated by extrusion molding around the outer periphery of the thread 1, a pair of metal conductors 2.3, and the separator 4 interposed therebetween. , 6 is a shielding material wrapped around the outer periphery of the heat-sensitive member 5, such as a single or composite material such as a heat-resistant plastic film, nonwoven fabric, or metal foil, or a heat-resistant fiber such as polyester or aromatic polyamide; is a heat-fusible insulator made of a polyolefin-based thermoplastic elastomer having heat-fusibility with a crystalline resin material, such as a thermoplastic elastomer consisting of an ethylene propylene resin component and an ethylene propylene rubber component.

FIG. 2 shows an application example in which the heat-sensitive wire 8 of this embodiment is made into a unit, where 8 is a heat-sensitive wire with a heat-fusible insulator 7 provided on the outermost shell, and 9 is a heat-sensitive wire 8. A heating wire 10 is placed above the heat-sensitive wire 8 and the heating wire 9, which are arranged in parallel, and is bonded by thermocompression. It is an adhesive film made of a crystalline resin material such as polyethylene, ethylene ethyl acrylate, polypropylene, etc. alone or in combination, which is welded to the heat-fusible insulator 7.

Next, the operation of the above configuration will be explained.

When the core thread 1 used in the present invention is wound around the metal electrode 2.3 and the separator 4, the outer diameter is 1.5 to 2.
By doubling the number, it is possible to improve the parallel winding performance and the workability of the end portion. In addition, by treating the surface of the core yarn 1 with the same or similar surfactant as the surfactant added in the heat sensitive body 5, the bleeding phenomenon of the surfactant in the heat sensitive body can be suppressed to a small level. , the change in impedance over time can be reduced.

Since the metal electrodes 2.3 are wound in parallel around the outer periphery of the core thread 1 with the separator 4 interposed, even when load stress is applied,
The metal electrodes 2 and 3 are no longer short-circuited, and impedance detection based on the temperature of the heat-sensitive element 5 can be performed without malfunction even after long-term use. Furthermore, a pair of metal electrodes 2.
3 can be wound in parallel around the outer periphery of the core yarn 1, so the number of work steps can be reduced by one compared to the conventional method.

The separator 4 is used to keep the distance between the two electrodes constant and obtain stable impedance during the work process of winding the metal electrodes 2.3 around the outer circumference of the core thread 1 in parallel, and to keep both electrodes from each other. This is provided to prevent crossing, and is an essential component of the present invention. As the material of the separator 4,
If heat-resistant fibers are used, the surface of the heat-resistant fiber can be treated with the same or similar surfactant as the surfactant added into the heat-receptor 5, and as a result, the bleeding of the surfactant in the heat-receptor 5 is reduced. Therefore, changes in impedance over time can be reduced.

Since the shielding body 6 is interposed between the heat sensitive body 5 and the heat-fusible insulator 7, the plasticizer, surfactant, etc. added to the heat-sensitive body 5 are transferred to the heat-fusible insulator 7. It also has the function of preventing the heat sensitive body 5 from deforming due to stress such as thermocompression bonding and loading. In addition, the shielding body 6 is replaced by the heat sensitive body 5.
In the case of wrapping around the thermosensitive member 5, the heat-fusible insulator 7 can be wrapped at the same time as the extrusion process by wrapping it around the heat-sensitive member 5 in a striped manner, thereby eliminating the cost of one step.

The heat-adhesive insulator 7 is made of a polyolefin-based thermoplastic elastomer material, so that it is difficult to permanently deform and has resilience even when subjected to stress such as thermocompression bonding or loading, and has rubber elasticity and temperature resistance. It is difficult to harden and maintains flexibility even when the temperature decreases, and since it is welded to the polyolefin adhesive film 10 by thermocompression bonding, the cord-shaped heat-sensitive wire 8
There are also effects such as the fact that the heating wire 9 can be easily formed into a planar unit.

The elasticity and hardness of a thermoplastic elastomer vary depending on its component ratio, but as properties suitable for the heat-fusible insulator 7, the hardness has a rubber hardness value of 50 to 100.

In the embodiment, an example was shown in which impedance is detected by winding the pair of metal electrodes 2.3 and the separator 4 in parallel around the outer circumference of the core yarn 1, but the present invention is not limited to this. Similar effects can also be obtained by winding a pair of metal electrodes 2.3 and a separator 4 in parallel around the outer surface of the heat sensitive body 5.

Effects of the Invention The present invention has the following effects and has great industrial utility value.

(a) The metal electrodes have a structure that does not easily short-circuit with each other even when the stress of a concentrated load is applied, so it has long-term durability.

(b) By wrapping a shield between the heat-sensitive body and the heat-fusible insulator, the end of the heat-sensitive wire can be easily peeled off, and the change over time of the thermistor can be kept small even at high temperatures.

CQ) By using a polyolefin-based thermoplastic elastomer as the heat-fusible insulator, it has rubber elasticity and excellent flexibility regardless of the temperature, and therefore it is easy to arrange in a meandering manner and can be easily bonded by thermocompression or by weight. It is difficult to deform under stress such as
Furthermore, it has excellent foldability when made into a planar heating device.

(d) It can be manufactured at low cost with fewer man-hours.

[Brief explanation of the drawing]

FIG. 1 is a structural diagram showing an embodiment of the present invention, and FIG. 2 is a sectional view of a heater unit to which the heat-sensitive wire of the present invention is applied. 2.3... Metal electrode, 4... Separator, 5... Heat sensitive body, 6... Shielding body. 7... Heat-fusible insulator

Claims (1)

[Claims] A cylindrical heat sensitive body (5) having a negative temperature coefficient, and a pair of metal electrodes (2) and (3) arranged in parallel on the inner or outer surface of the heat sensitive body (5) with a separator (4) in between. and a heat-fusible insulator (7) made of polyolefin-based thermoplastic elastomer, which is coated on the outer periphery of the heat-sensitive member (5) via a shield (6).