JPH0523035B2 - - Google Patents

Description

Detailed Description of the Invention (Technical Field) The present invention relates to a linear
The present invention relates to a planar heat-sensitive element and a heat-sensitive heat-generating element that integrates a heat-sensitive element part and a heat-generating part.

(Background Art) Conventionally, in electric carpets, heat-sensitive wires have been used in combination with heat-generating wires, as shown in FIG.

That is, a tubular negative polymer thermosensitive material (heat-sensitive resin material) 3 whose impedance changes according to temperature changes, an outer electrical conductor wire 4 wound around the outer surface of the tubular electrical conductor wire 4, and a negative electrical conductor wire 4 wound around the core wire 1. Inner-wound electric conductor wire 2 arranged on the inner surface of the characteristic polymer temperature sensitive body 3
and an insulating layer 5 provided on the outer surface of the outer-wound electrical conductor wire 4 were used.

Further, FIG. 4 shows another example, in which 3 is a negative characteristic polymer temperature sensitive body, 2, 4, and 6 are electrical conductor wires, and 5 is an insulating layer.

Incidentally, in this type of heat-sensitive element, a material obtained by kneading a PVC material with a plasticizer, an ionic additive, etc. is used as the negative-characteristic polymer temperature-sensitive body 3, and an insulating layer 5 on the outer surface is used.
Heat-resistant PVC material is also used. The reason for this is that it has lower hygroscopicity than polyamide-based materials known as other practical negative-characteristic polymer thermosensitive materials, and its impedance |Z| changes less with time.

However, in recent years, the surface materials for electric carpets have changed from the conventional needle punch type, which is thin and has low heat insulating properties, to thicker, softer, and more heat insulating materials such as tufted weaves, which have improved the carpet life. These products are becoming more popular with the growing desire for authenticity, and in order to accommodate this trend, it has become necessary to raise the temperature of the internal heater to a higher temperature than before. Correspondingly, the temperature of heat-sensitive wires also tends to increase.

In addition, in the past, a so-called two-wire system was used in which a pair of heat-generating wires was used in addition to the heat-sensitive wire, but the so-called one-wire system, in which one electrode of the heat-sensitive wire was used as the heat-generating wire, was used. Studies are also being conducted due to demands for cost reduction and improved safety. In this case as well, as described above, the temperature of the negative polymer temperature sensitive body tends to be higher than the conventional temperature because it is in contact with the heating wire.

In this way, when the temperature of the negative polymer thermosensitive element increases, the bleed-out phenomenon of plasticizer in the thermosensitive element made of PVC material becomes a value that cannot be ignored, and the impedance changes over time in the direction of increasing. In some cases, the temperature could reach dangerous levels due to a decline in temperature detection ability.

(Objective of the Invention) The present invention has been proposed in view of the above points, and provides a heat-sensitive element that has a higher limit temperature at which the impedance value does not change over time than conventional heat-sensitive elements, and is easily compatible with the desire for authentic surface materials. The object of the present invention is to provide a feasible configuration of a heat-sensitive element having a heat-generating function that integrates a heat-sensitive wire and a heat-generating wire.

(Disclosure of the Invention) The present invention requires the use of a plasticizer for PVC-based thermosensitive resin, and when the plasticity decreases (that is, when it bleeds out), the volume-specific impedance increases, causing a change in impedance over time. With this in mind, it is characterized by a structure in which the plasticizer does not easily bleed out, and the use of a plasticizer that does not easily bleed out.

Preferred embodiments of the present invention will be described below.

〔sample〕

Samples were prepared from heat-sensitive resin and insulator materials with different types and amounts of plasticizer added, and a prototype heat-sensitive element with the specifications shown below was fabricated.

〔Evaluation methods〕

The prototype heat-sensitive element was cut into 3m lengths and heated to 120℃.
A voltage of AC100V, 60Hz is applied in an ON-OFF cycle in an atmosphere, and the impedance change of each sample is measured using the voltage drop method at each elapsed time, and plotted on a graph to determine how much the impedance value has changed compared to the initial value. We compared what we did.

[Sample composition and dimensions]

As shown in FIG. 1, the heat-sensitive element includes a core wire 1, an inner-wound electric conductor wire 2 wound around the outer surface of the core wire, and a tubular negative characteristic polymer temperature sensor 3 arranged on the outer surface of the core wire 1.
and an outer electrical conductor wire 4 wrapped around its outer surface.
, a separation layer 7 and an insulating layer 5 disposed on the outer surface thereof.

In addition, the dimensions of each part were as follows.

Core perforation 1...0.5mmφ polyester wrapped electrical conductor wire 2...0.08mm x 0.8mm copper plated with Ni-plated foil wrapped in 0.75mm pitch Negative polymer thermosensitive material 3...Thermosensitive resin 0.3mm thick Extruded outer-wound electric conductor wire 4... 0.08 mm x 0.8 mm copper wrapped with Ni-plated foil at a pitch of 1.05 mm Separation layer 7... Polyester tape 12μ2/3 wrap wrapped insulation layer 5... Insulator extruded to a thickness of 0.4 mm [Conventional specifications] A conventional heat-sensitive element used for comparison was set as follows.

Heat-sensitive resin PVC Average degree of polymerization = 1300 100 parts Plasticizer Phthalate ester plasticizer 40 parts Stabilizer Tribasic lead sulfate 5 parts Modifier Quaternary ammonium salt 0.5 parts Insulator PVC Average degree of polymerization = 1300 100 parts Plasticizer Phthal Acid ester plasticizer 40 parts Stabilizer Tribasic lead sulfate 5 parts [Example] Heat-sensitive resin PVC Average degree of polymerization = 1300 100 parts Plasticizer Trimellitic acid ester plasticizer 40 parts Stabilizer Tribasic lead sulfate 5 parts Modifier No. Quaternary ammonium salt 0.5 parts Insulator PVC Average degree of polymerization = 1300 100 parts Plasticizer Trimellitic acid ester plasticizer 55 parts Stabilizer Tribasic lead sulfate 5 parts [Example] Thermosensitive resin PVC Average degree of polymerization = 1300 100 parts Plasticizer Trimellitic acid ester plasticizer 40 parts Stabilizer Tribasic lead sulfate 5 parts Modifier Quaternary ammonium salt 0.5 parts Insulator PVC Average degree of polymerization = 1300 100 parts Plasticizer Pyromellitic acid ester plasticizer 55 parts Stabilizer Tribasic sulfuric acid Lead 5 parts [Example] Heat-sensitive resin PVC Average degree of polymerization = 1300 100 parts Plasticizer Pyromellitic acid ester plasticizer 40 parts Stabilizer Tribasic lead sulfate 5 parts Modifier Quaternary ammonium salt 0.5 parts Insulator PVC Average degree of polymerization =1300 100 parts Plasticizer Pyromellitic acid ester plasticizer 55 parts Stabilizer Tribasic lead sulfate 5 parts The structural formula of the plasticizer used in each of the above examples is as follows.

Trimellitic acid ester plasticizer Pyromellitic acid ester plasticizer The evaluation results at 120° C. are shown in FIG. 2, and as can be seen from the figure, the changes in impedance over time in the examples of the present invention are significantly improved compared to the conventional product A.

Although not shown, the impedance change in the example of the present invention is even smaller than the impedance change at 100°C of the conventional product, and it can be determined that the usable limit temperature is 20 degrees higher than that of the conventional product. can.

These effects are due to the synergistic effect of increasing the amount of plasticizer in the outer insulating layer 5 than the amount of plasticizer in the thermosensitive resin used for the internal negative characteristic polymer temperature sensitive body 3 and increasing the molecular weight of the plasticizer. As a result, the bleed-out of the plasticizer was significantly reduced and the change in impedance over time was improved.

It goes without saying that the present invention is not limited to the tubular or cable-like structures as shown in FIG. 1, but can also be applied to linear or planar structures as shown in FIG. 4.

(Effects of the Invention) As described below, the heat-sensitive element according to the present invention includes a tubular negative-characteristic polymer temperature-sensitive body whose impedance changes according to temperature changes, and an outer electric conductor wire wound around the outer surface of the tubular negative-characteristic polymer temperature-sensitive body. and an insulating layer arranged on the outer surface of the outer-wound electrical conductor wire; The negative characteristic polymer thermosensor is made of a material obtained by kneading a PVC material, a trimellitic acid plasticizer, and an ionic additive, and the insulating layer is made of a PVC material, and the trimellitic acid plasticizer is mixed with the negative characteristic polymer thermosensor. Furthermore, since the plasticizer added to the negative characteristic polymer temperature sensitive body and the insulating layer is a pyromellitic acid plasticizer, Since the plasticizer added to the molecular thermosensitive element is a trimellitic acid plasticizer, and the plasticizer added to the insulating layer is a pyromellitic acid plasticizer, (a) the impedance stability limit temperature of the thermosensitive element is significantly lowered. Improved when applied to electric carpets,
Even if a surface material with good cushioning properties is used, it is possible to set the surface temperature to a sufficiently warm temperature.

(b) It becomes possible to realize a one-wire system in which one electrode of the heat-sensitive element is used as a heating wire.

(c) The amount of plasticizer in the outer insulating layer is greater than the amount of plasticizer in the inner negative polymer thermosensitive material, so when finished in a linear shape, it is easy to bend and the force is not concentrated locally. The electrical conductor wire can be made less likely to break even if it is repeatedly bent.

There are other effects.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing the structure of an embodiment of the heat-sensitive element of the present invention, FIG. 2 is a characteristic diagram showing evaluation results, and FIGS. 3 and 4 are structural diagrams of a conventional heat-sensitive element. DESCRIPTION OF SYMBOLS 1... Core wire, 2... Inner-wound electrical conductor wire, 3... Negative characteristic polymer temperature sensitive body, 4... Outer-wound electrical conductor wire, 5...
...Insulating layer, 7...Separation layer.

Claims (1)

[Scope of Claims] 1. A tubular negative characteristic polymer temperature sensitive body whose impedance changes in accordance with temperature changes, an outer-wound electrical conductor wire wound around the outer surface of the tubular negative characteristic polymer temperature sensitive body, and the negative characteristic polymer temperature sensitive body wound around a core wire. In a heat-sensitive element consisting of an inner-wound electric conductor wire arranged on the inner surface of the temperature-sensitive element and an insulating layer arranged on the outer surface of the outer-wound electric conductor wire, the negative-characteristic polymer temperature-sensitive element is trimmed into a PVC material. It is made of a material kneaded with an acid plasticizer and an ionic additive, and the insulating layer is made of a PVC material with a trimellitic acid plasticizer added in a larger amount than the negative characteristic polymer thermosensitive material. A heat-sensitive element characterized by 2. The heat-sensitive element according to claim 1, wherein either one of the electric conductor wires also serves as a heating wire. 3. A tubular negative polymer temperature sensitive body whose impedance changes in accordance with temperature changes, an outer electric conductor wire wound around the outer surface of the tubular negative polymer temperature sensitive body, and a core wire wound around the inner surface of the negative polymer temperature sensitive body. In a heat-sensitive element comprising an inner-wound electrical conductor wire and an insulating layer disposed on the outer surface of the outer-wound electrical conductor wire, the negative characteristic polymer thermosensor and the plasticizer added to the insulating layer are pyromerite. A heat-sensitive element comprising an acid plasticizer. 4. The heat-sensitive element according to claim 3, wherein either one of the electric conductor wires also serves as a heating wire. 5. A tubular negative polymer temperature sensitive body whose impedance changes in accordance with temperature changes, an outer electric conductor wire wound around the outer surface of the tubular negative polymer temperature sensitive body, and a core wire wound around the inner surface of the negative polymer temperature sensitive body. In a heat-sensitive element comprising an inner-wound electrical conductor wire and an insulating layer arranged on the outer surface of the outer-wound electrical conductor wire, the plasticizer added to the negative characteristic polymer thermosensitive member is a trimellitic acid-based plasticizer. A heat-sensitive element, wherein the plasticizer added to the insulating layer is a pyromellitic acid plasticizer. 6. The heat-sensitive element according to claim 5, wherein either one of the electric conductor wires also serves as a heating wire.