JPS58123B2 - temperature sensitive wire - Google Patents

Description

[Detailed description of the invention] This invention relates to an improved thermosensitive wire.

Temperature-sensitive electric wires used in electric blankets etc. are made by wrapping a primary conductor such as copper alloy tape around a fiber core wire such as glass fiber, and then wrapping a secondary conductor on the outside of the wire through a thermo-sensitive resin layer. It is constructed by covering with a suitable protective layer such as soft polyvinyl chloride.

Conventionally, soft vinyl chloride, nylon, polyvinylidene fluoride resin, or the like has been generally used as the temperature-sensitive resin layer in the temperature-sensitive electric wire.

However, for example, in the case of using a soft vinyl chloride resin, the temperature-sensitive characteristics inevitably deteriorate due to its thermal history, and therefore, the appropriate continuous use temperature is usually about 80° C. or lower.

However, products using nylon-based resins similarly suffer from a decline in temperature-sensing properties due to the presence of moisture due to moisture absorption, and even nylon 11 and nylon 12, which are usually said to have good thermosensitivity, have poor temperature-sensing properties. At present, it is difficult to say that the improvement has been sufficient.

The inventors conducted extensive studies to improve the drawback of conventional temperature-sensitive electric wires, such as the deterioration of temperature-sensing characteristics in environments such as heat or water, and as a result, they decided to use polybutylene terephthalate resin as the temperature-sensitive resin layer. They discovered that when used, an electric wire with stable temperature-sensing characteristics could be obtained without causing the deterioration of temperature-sensing characteristics due to thermal history or moisture, which was seen in conventional products, and completed this invention.

That is, the present invention provides a temperature-sensitive electric wire in which a primary conductor is wound around a fiber core wire such as glass fiber, a secondary conductor is wound on the outside of the core wire through a moisture-sensitive resin layer, and the outermost layer is covered with an appropriate protective layer. The moisture-sensitive electric wire is characterized in that the moisture-sensitive resin layer is formed from a composition containing polybutylene terephthalate resin as a main component.

In this invention, as the temperature-sensitive resin layer, a resin composition containing polybutylene terephthalate resin as a main component is used as described above, but other resin compositions that can be well mixed with this, such as butylene terephthalate and Ike's ester, are used. Ether copolymers, polycaprolactone, etc. can also be mixed.

Generally, an appropriate amount of surfactant is added to the moisture-sensitive resin layer forming material in order to sharpen the temperature change in the impedance of the moisture-sensitive resin layer, but the polybutylene terephthalate resin used in the present invention also For this purpose, surfactants are blended, and ethylene oxato-based surfactants, quaternary alkyl ammonium salts, and alkyl betaine-based surfactants are particularly preferred, among which surfactants of the following formulas (1) and (2) are Surfactants selected from the chlorate group are most preferred because of their effectiveness and because they do not impair the heat resistance of the mixture.

This type of surfactant is available under the trade name Niregan ASK.
(Nippon Oil Company) etc. are commercially available.

Embodiment FIG. 1 is a partially cutaway view of the configuration of a temperature-sensitive electric wire 1 according to an embodiment of the present invention. As 3, a copper alloy tape with a width of Q and a thickness of 0.05 m'In is wound counterclockwise at a pitch of Q and 7 mm.
A composition consisting of 100 parts of polybutylene terephthalate resin (manufactured by Toshisha Co., Ltd. +1401) and a surfactant (2 parts of New Nilegan ASK, manufactured by Nihon Yushi Co., Ltd.) was extrusion coated on the outside as a temperature-sensitive resin layer 4 to a thickness of 0.2E17M. .

Second, a copper alloy tape similar to the above is wound clockwise on this outer circumference as a secondary conductor 5 at a pitch of 1.2 mm, and finally, a soft vinyl chloride composition is wound as a protective layer 6 with a thickness of 0.5 mm.
It is formed by thick extrusion coating.

When we investigated the moisture sensitivity characteristics of this equipment, we found that the second
It had a hot water temperature dependence of AC impedance (50 Hz sine wave) as shown in the curve shown in the figure, and had excellent temperature sensing characteristics.

Next, in order to compare with this experimental equipment, the temperature-sensitive resin layer in the above experimental equipment was replaced with soft vinyl chloride (comparison amount 1) with the composition of Note 1 (composition below) and nylon 12 (comparative amount 2) with the composition of Note 2, and the other Each temperature-sensitive electric wire was obtained in exactly the same manner as described above.

A heating test and an underwater standing test as shown in Table 1 were conducted on the experimental equipment and comparative example products thus obtained.

The obtained results are shown in the same table.

(Note 1) Vinyl chloride resin 100 parts (Nippon Zeon Co., Ltd. 101EP) Tri-n-octyl trimellitate 50 Tribasic sulfate 10 Surfactant (New Elegans 2) (Note 2) Nylon 12 ( 2,1179 Company □94o, 100 parts Surfactant (New Elegance) 2" According to the results in the table above, the equipment implementing this invention has a comparative amount of On the other hand, it was clear that there was little change in the moisture sensitivity characteristics and that the material had extremely stable temperature sensitivity characteristics.

As explained above, this invention uses a composition containing polybutylene terephthalate resin as the main component for the temperature-sensitive resin layer in the temperature-sensitive electric wire, so that it is less susceptible to heat history or the presence of moisture than conventional products. It is possible to provide an excellent and stable temperature-sensitive wire with significantly less deterioration in temperature-sensitive characteristics, and its industrial value is extremely large.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram showing a cut away main part of the temperature-sensitive electric wire of the present invention, and FIG. 2 is a temperature-sensing characteristic diagram of the same example product. 2... Core wire, 3, 5...-Next and secondary conductor, 4... Sensing resin layer, 6... Protective layer.

Claims (1)

[Claims] 1 Wrap the primary conductor around a fiber core wire such as glass fiber,
In a moisture-sensitive electric wire in which a secondary conductor is wound on the outside through a temperature-sensitive resin layer and the outermost layer is covered with an appropriate protective layer, the temperature-sensitive resin layer is formed from a composition containing polybutylene terephthalate resin as a main component. A temperature-sensitive electric wire that is characterized by