JPS5831267Y2 - Overtemperature detection wire - Google Patents

Description

[Detailed description of the invention] The present invention relates to the improvement of overtemperature detection wires used for fire alarms, etc., especially overtemperature detection wires with an operating temperature of 90°C to 1.00°C. Weight average molecular weight is 80,000 to 2
It is characterized by being made by twisting together multiple insulated wires coated with uncrosslinked 1,2 polybutadiene with a crystallinity of 10% to 40%, and is laid in a pear shape due to the heat generated during a fire. The insulation coating layer of the above-mentioned overtemperature detection wire softens, and the softened insulation coating layer is squeezed out from between the twisted highly elastic metal conductors, and the conductors eventually come into contact with each other, causing a short circuit in the electrical circuit. Therefore, an overtemperature condition can be detected.

Conventionally, vinyl chloride (PVC)-based insulating materials have generally been used as insulating materials for this type of overtemperature detection wire whose operating temperature is 90° C. to 100° C.

For example, a typical example is a mixture consisting of 100 parts of vinyl chloride resin, vinyl acetate resin copolymer (realization degree of about 800), 10 parts of dioctyl phthalate, 5 parts of decyclohexyl phthalate, and 5.5 parts of a stabilizer. .

As described above, the overtemperature detection wire using PVC-based insulating material has the following drawbacks.

That is, (1) If the insulation coating layer is left for a long period of time after installation, the plasticizer mixed into the insulation coating layer will be released and the softening characteristics of the insulation coating layer will change, making the operating temperature likely to become unstable.

(2) When PVC is in contact with steel wire for a long period of time in an atmosphere of about 60° C., the surface of the steel wire tends to corrode due to hydrogen chloride generated by the gradual thermal deterioration of PVC.

In view of the above, the present invention has a sharp softening property comparable to or better than that of PVC-based insulating materials, has a stable operating temperature over a long period of time, and has a steel wire surface that is stable even in an atmosphere of about 60°C. We strived to develop an insulating material that does not corrode the
They discovered polybutadiene.

An embodiment of the overtemperature detection line according to the present invention is shown in FIG.

In Fig. 1, 1 is a conductor 11 made of steel wire with an outer diameter of 0.9 mm, a weight average molecular weight of 100,000, and a crystallinity of 20%.
0.4 m thick made of uncrosslinked 1,2 polybutadiene
This is an insulated strand provided with an insulation coating 12 of m, and two insulated strands 1 are twisted together.

A Mylar tape was applied to the stranded wires, and then 0
．． The softening characteristics of the overtemperature detection wire coated with nylon having a thickness of 15 mm are shown in FIG. 2, and as shown in the figure, it exhibits sharp softening characteristics.

In Figure 2, the vertical axis is the ambient temperature ('C), and the horizontal axis is
This is the time (minutes) it takes for conductors to come into contact with each other.

The 1,2 polybutadiene used in the overtemperature detection wire of the present invention has a weight average molecular weight of 80,000 to 200,000, preferably 100,000 to 16
10,000, and the crystallinity is 10% to 40%, preferably 15
It has a content of 25% to 25% and constitutes an insulating coating layer in an uncrosslinked state.

Anything with an average molecular weight or crystallinity outside the above range is not preferred.

That is, if the weight average molecular weight is less than 80,000, it is difficult to liquefy and form a coating layer.

If it exceeds 200,000, the melting temperature will be high and the operating time will be long.

Further, if the degree of crystallinity is less than 10φ, the resin will be easily deformed even at room temperature under pressure, and if it exceeds 40, the melting point will be so high as to exceed the limit of thermal stability of the resin, making processing difficult.

As mentioned above, the overtemperature detection line of the present invention is 90 to 100℃.
It has a sensitive overtemperature detection performance under the ambient temperature of
Moreover, since the insulating material used does not contain a plasticizer and does not generate hydrogen chloride, the above-mentioned problems that occur when using a PVC-based insulating material are eliminated, and stable performance can be maintained over a long period of time.

Usually PVC to pure 1,2 polybutadiene as required
It is also possible to add fillers, pigments, etc. in amounts similar to those used in .

[Brief explanation of drawings]

Figure 1 is a sectional view of one embodiment of the overtemperature detection wire of the present invention, Figure 2
The figure is a graph showing the softening characteristics of one embodiment of the overtemperature detection line of the present invention. In Fig. 1, 11...conductor, 12...
...Insulating coating layer, 1...Insulating wire.

Claims (1)

[Scope of utility model registration request] On a highly elastic metal conductor, the weight average molecular weight is 80,000 to 200,000,
An overtemperature detection wire made by twisting together a plurality of insulated wires coated with uncrosslinked 1,2 polybutadiene having a crystallinity of 10% to 40%.