JPH0332009Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Field of Application] This invention relates to a coaxial cable for use in low-noise communication applications that has significantly increased flexibility.

[Conventional technology]

Due to cable bending and other mechanical vibrations,
Electrostatic charges are generated when the conductor and dielectric slide against each other,
In order to prevent the phenomenon of noise caused by this,
Conventional low-noise cables are extremely flexible because a semiconducting layer is placed between the conductor and dielectric, and these layers are tightly coupled to each other to prevent sliding. It was scarce.

For this reason, as described in JP-A-51-100289, for example, by irradiating the cable with ionizing radiation and then heat-treating it at a temperature of 100°C or higher, the low noise characteristics can be improved and the adhesion between each layer can be strengthened. A method has been proposed that can reduce the

However, in such a method, not only the manufacturing equipment is expensive but also the number of steps is large, making it uneconomical.

[Problem that the invention attempts to solve]

After careful consideration, we found that if a fluorine-containing resin semiconducting layer is placed on the conductor surface and a fluororesin is used as the dielectric material in contact with this semiconducting layer, noise will be extremely low.
We have discovered that this cable can also be made with excellent flexibility.

That is, this invention aims to provide a coaxial low-noise cable with excellent flexibility.

[Means for solving problems]

Therefore, according to this invention, there is provided a central conductor having a fluororesin semiconductive layer on the outer periphery, a fluororesin dielectric provided on the outside of the center conductor, and a fluororesin dielectric provided on the outside of the dielectric at least on the inner circumferential surface. A coaxial flexible low-noise cable comprising an outer conductor having a fluororesin semiconductive layer, an expanded tetrafluoroethylene resin layer disposed outside the outer conductor, and a soft vinyl chloride resin sheath disposed on the outermost periphery. Configure.

[Effect]

The fluorine-containing resin semiconductive layer on the surface of the conductor and the dielectric material slide well together, making the cable functional part highly flexible.

Furthermore, since the fluororesin semiconductive layer has a structure in which a conductive substance is dispersed in the fluororesin, it is stable and does not generate noise even when sliding with the fluororesin dielectric.

Further, the expanded tetrafluoroethylene resin layer disposed between the outer conductor and the sheath acts as an elastic lubricant to increase the flexibility of the cable.

〔Example〕

The figure shows a cross-sectional view of a coaxial flexible low-noise cable 1 according to this invention.

A fluorine-containing resin semiconductive layer 3 is provided around the outer periphery of the central conductor 2 of this cable 1.

As this fluorine-containing resin semiconductive layer 3, for example, a plating layer called Metaflon plating film, which is a eutectoid composite of fluororesin particles, can be used.
In the case of this plating layer, a layer having good sliding properties, self-lubricating properties, and not only excellent wear resistance but also excellent non-electrostatic properties can be obtained.

The outside of the center conductor 2 is made of expanded porous tetrafluoroethylene resin (PTFE), foamed tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin (PFA), and tetrafluoroethylene-ethylene copolymer resin (ETFE). ) A fluororesin dielectric 4 made of other fluororesin or the like is provided. On the outside of this dielectric 4, an outer conductor 7 having fluorine-containing resin semiconductive layers 5 and 6 on both the inner and outer surfaces is provided concentrically with the center conductor 2, forming a functional part of the coaxial cable 1. . Such an external conductor 7 can be formed of, for example, a braided layer of a conductor having a fluorine-containing resin semiconductive layer on its outer periphery, or a film layer having a fluorine-containing resin semiconductive layer on both sides.

A soft vinyl chloride resin sheath 9 is provided on the outer periphery of the external conductor 7 with a stretched tetrafluoroethylene resin layer 8 interposed therebetween. As a result, due to the presence of the expanded tetrafluoroethylene resin layer 8, the outer conductor 7 and the sheath 9
The presence of the soft vinyl chloride resin sheath provides a highly flexible sheath that is water resistant, acid resistant, alkali resistant, highly flame retardant, and highly flexible. Become.

Therefore, according to this invention, the functional part of the cable is highly flexible, and the sheath surrounding this functional part is also highly flexible, resulting in a coaxial cable that is not only highly flexible as a whole, but also has excellent low noise properties. This results in a cable that has been modified.

[Effect of idea]

As described above, according to this invention, there is provided a central conductor having a fluorine-containing resin semiconductive layer on the outer periphery, a fluororesin dielectric provided on the outside of this central conductor, and at least an inner circumferential surface provided on the outside of this dielectric. an outer conductor having a fluorine-containing resin semiconductive layer; an expanded tetrafluoroethylene resin layer disposed outside the outer conductor;
By configuring a coaxial flexible low-noise cable with a soft vinyl chloride resin sheath provided on the outermost periphery, a coaxial cable with excellent flexibility and low-noise properties can be obtained economically, and it is practical. There are some things that are very effective.

[Brief explanation of the drawing]

The figure shows a cross-sectional view of a coaxial flexible low-noise cable according to an embodiment of the invention. DESCRIPTION OF SYMBOLS 1: Coaxial flexible low-noise cable, 2: Center conductor, 3, 5, 6: Fluorine-containing resin semiconductive layer, 4: Fluororesin dielectric, 7: Outer conductor, 8: Stretched tetrafluoroethylene resin layer, 9: Soft vinyl chloride resin sheath.

Claims (1)

[Scope of utility model registration request] A central conductor having a fluororesin semiconducting layer on the outer periphery, a fluororesin dielectric provided outside the center conductor, and an external conductor having a fluororesin semiconducting layer provided at least on the inner peripheral surface of the dielectric. A coaxial flexible low-noise cable comprising a conductor, an expanded tetrafluoroethylene resin layer provided on the outside of the outer conductor, and a soft vinyl chloride resin sheath provided on the outermost periphery.