JPH02210717A - Flame retardant cable - Google Patents

Abstract

PURPOSE:To obtain a flame retardant cable with improved flexibility, working property, and no problem as to environmental sanitation by using synthetic fiber or natural fiber instead of glass fiber for a cable jacket, and applying fluorine rubber onto the outer surface thereof. CONSTITUTION:In a flame retardant cable 1, the core part thereof consists of a plurality of insulated wires 5 each comprising a conductor 3 having an insulating cover of fluorine resin 2 with the wires 5 being stranded, and the outside thereof is covered by a cable jacket 7 via a separator 6. The cable jacket 7 is a bladed member consisting of cotton yarn which is organic fiber, and has a cover layer 8 providing multilayer cover for the insulated wires 5, and a fluorine rubber layer 9 formed on the outer surface of the cover layer 8. The fluorine rubber layer is formed by applying liquid fluorine rubber on the outer surface of the cover layer 8, and curing it. The term organic fiber used herein, includes natural fiber, synthetic fiber, and carbon fiber. Thus, a cable with improved flexibility, working property, and no problem as to environmental sanitation, and an improved flame retardant characteristic can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a flame-retardant cable, and particularly to a flame-retardant cable suitable for use in aircraft, railway vehicles, automobiles, and the like.

(Prior technology) In general, fluororesin insulated wires have excellent electrical properties and flame retardant properties, and can be made thinner than other insulated wires, so they are used in aircraft, railway vehicles, automobiles, etc. It is becoming widely used.

Conventionally, in cables in which the outside of a fluororesin insulated wire is covered with a cable jacket, the cable jacket is usually made of a plastic material such as fluororesin, vinyl chloride, or polyethylene, or a rubber such as silicone rubber, fluororubber, or chloroprene rubber. There is a type in which the material is extruded and coated onto the outer surface of an insulated wire using an extruder or the like.

In addition, especially for flame-retardant cables that emphasize flame-retardant properties, the cable jacket material of the cable is coated with fluororesin or braided material mainly made of glass fiber, and the surface of the cable is coated with silicone rubber or other materials. Some are coated with water-based fluororesin dispersion.

(Problem M to be Solved by the Invention) However, conventional fluororesin-coated devices have drawbacks such as insufficient flexibility and inferior workability for wiring and terminal processing. In addition, when cutting glass fibers, it is difficult to cut out the glass fibers, which takes time, and furthermore, the glass fibers get stuck in the skin of the worker during the cutting process, causing discomfort to the worker. There are also environmental health problems, such as workers inhaling glass fiber particles suspended in the air, which can harm the health of workers.

An object of the present invention is to solve the problems of the prior art and to provide a flame-retardant cable that has excellent flexibility and workability, and has excellent flame-retardant properties that pose no problems in terms of environmental hygiene.

(Means for Solving the Problems) As a result of various studies to achieve the above object, the present inventors used synthetic fibers or natural fibers instead of glass fibers for the cable jacket, and We found that applying fluororubber was effective.

The present inventors further conducted various studies and reached this conclusion.

That is, the flame-retardant cable according to the present invention is a flame-retardant cable in which the outside of an insulated wire is covered with a cable jacket, and the cable jacket has a coating layer covered with a braided material made of organic fibers, and an outer surface of the coating layer. It is characterized by having a fluororubber layer formed thereon. Also,
Preferably, the organic fibers are synthetic fibers. Moreover, it is preferable that the organic fiber is a natural fiber.

Here, organic fibers include natural fibers, synthetic fibers, and carbon fibers.

(Function) Since the coating layer of the flame-retardant cable of the present invention uses a braided material made of organic fibers, it is easy to remove the organic fibers at the end of the cable during wiring work, and it does not damage the worker's skin. or cause respiratory problems.

In addition, unlike cables using conventional glass fibers, they are expensive and pose environmental health problems.

Furthermore, since the fluororubber layer is formed on the outer surface of the braided material made of organic fibers, a cable can be obtained that has flame retardant properties that are superior to, or inferior to, cables using conventional glass fibers.

Furthermore, compared to applying water-based fluororesin dispersion to cables using glass fibers, the process of applying and curing the fluororubber layer allows for vulcanization and curing at extremely low temperatures. There is little thermal damage to the internal insulated wires.

(Example) The present invention will be explained below with reference to the drawings.

The figure is a perspective view showing an example of a flame-retardant cable according to the present invention. Reference numeral 1 denotes a flame-retardant cable, and the flame-retardant cable 1 is made by twisting together a plurality of insulated wires 5 (four in this example), each of which has a fluororesin 2 in its core and an insulation coating on the outside of a conductor 3. The outside is covered with a cable jacket 7 via a separator 6. The cable jacket 7 has a covering layer 8 in which the insulated wire 5 is covered in multiple layers with a braided material made of cotton yarn, which is an organic fiber, and a fluororubber layer 9 formed on the outer surface of the covering layer 8. The fluororubber layer 9 is formed by applying liquid fluororubber on the outer surface of the coating layer 8 and vulcanizing it.

Here, the organic fibers may be synthetic fibers, natural fibers, or carbon fibers, and examples of the synthetic fibers include nylon fibers, polyester fibers, aramid fibers, etc., and examples of the natural fibers include cotton threads, silk threads, etc. can be mentioned.

There are various methods for applying liquid fluororubber on the outer surface of the coating layer 8, but for example, an insulated wire coated with a braided material may be coated with fluororubber and a compounding agent dispersed in a dispersant. After being immersed in a fluororubber dispersion liquid, it is heated to a predetermined temperature (for example, 250 to 250″C).
A method of continuously vulcanizing and winding in a vulcanizing furnace heated to It is preferable to apply fluororubber not only to the surface of the braided material but also to the entire surface of the braided material. Furthermore, fluororubber may penetrate into the braided material.

In the present invention, it is particularly important to combine fluororubber with the coating layer of the braid made of organic fibers. Conventional braided material mainly made of glass fiber (covering layer)
Even if silicone rubber, alkyd resin, fluororesin, etc., which have been used to coat the surface of the organic fibers, are applied to the coating layer made of organic fibers, satisfactory flame retardant performance cannot be obtained.

Cables obtained by variously changing the material of the coating layer and the coating agent applied to the surface of the ffJi were subjected to a vertical flame retardant test specified by UL safety standards, and the results of evaluating the flame retardant performance (burning time) were as follows. Shown in the table below.

As shown in this table, it is clear that a unique flame retrieval effect can be obtained by combining a coating layer made of organic fibers such as cotton yarn or polyester fiber with fluororubber.

In the above description, an example has been described in which a plurality of fluororesin insulated wires are twisted together, but it goes without saying that only one conducting wire may be coated with fluororesin.

(Effects) As described above, according to the present invention, it is possible to provide a cable that is excellent in flexibility and workability, and has excellent flame retardant properties that cause no problems in terms of environmental hygiene.

[Brief explanation of the drawing]

The figure is a perspective view showing an embodiment of the flame-retardant cable of the present invention. DESCRIPTION OF SYMBOLS 1...Flame retardant cable, 5...Insulated wire, 7...Cable jacket, 8...Coating layer, 1...Fluorine rubber layer.

Claims (3)

[Claims] (1) In a flame-retardant cable in which the outside of an insulated wire is covered with a cable jacket, the cable jacket has a covering layer covered with a braided material made of organic fibers and a fluororubber layer formed on the outer surface of the covering layer. A flame-retardant cable comprising: (2) The flame-retardant cable according to claim 1, wherein the organic fiber is a synthetic fiber. (3) The flame-retardant cable according to claim 1, wherein the organic fiber is a natural fiber.