JP2002245866A - Cable for x-ray - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a X-ray cable having excellent dielectric breakdown property. SOLUTION: A high tension insulator is composed of a resin component which contains ethylene-propylene-diene terpolymer, containing ethylene by 50-60 weight %, by 100 weight portion, FT carbon black with an average grain diameter of 90-500 μm, or MT carbon black with an average grain diameter of 90-500 μm by 0.1-1.0 weight portion, and Mistron Vapor Talc (R) by 50 weight portion or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an X-ray cable.

[0002]

2. Description of the Related Art As this kind of cable, a total of four insulated wires, two insulated wires provided with an insulator on the outer periphery of a conductor and two bare conductors, are twisted, and a semiconductive layer and a high-voltage insulator are sequentially provided on the outer periphery thereof.
Further, a structure in which a shielding layer and a sheath are sequentially provided on the outer periphery is known. In such a configuration, the high-pressure insulator is formed of a resin composition based on ethylene propylene rubber (EPR) and added with FEF carbon black and the like.

[0003]

However, the conventional X-ray cable has a problem that the insulation performance under a humid environment is remarkably deteriorated and the breakdown voltage is not stable.

[0004] It is an object of the present invention to provide an X-ray cable having excellent dielectric breakdown characteristics.

[0005]

In order to achieve the above object, the present invention provides an ethylene propylene diene terpolymer (EPDM) having an ethylene content of 50 to 60% by weight.
00 parts by weight, 0.1 to 1.0 parts by weight of FT carbon black having an average particle diameter of 90 to 500 μm or MT carbon black having an average particle diameter of 90 to 500 μm, and 50 parts by weight or more of Mythrone vapor talc (MVT) Provided is an X-ray cable having a high-voltage insulator formed from a resin composition containing the same.

[0006]

FIG. 1 is an explanatory sectional view of an embodiment of an X-ray cable according to the present invention. The insulated wire 3 is formed by applying the insulator 2 to the outer periphery of the conductor 1, and the core 5 is formed by twisting two of the insulated wires 3 and two of the bare conductors 4. A semiconductive layer 6 and a high-voltage insulator 7 are sequentially provided on the outer periphery of the core 5, and a shielding layer 8 and a sheath 9 are provided on the outer periphery of the high-voltage insulator 7 as necessary.

The high-voltage insulator 7 has an ethylene content of 50 to 50.
100 parts by weight of 60% by weight of EPDM having an average particle size of 90
FT carbon black having a mean particle size of 9 to 500 μm
MT carbon black of 0 to 500 μm is added to 0.1-1.
It is formed of a resin composition containing 0 parts by weight and 50 parts by weight or more of MVT.

In the present invention, the ethylene content is 50 to
The use of 60% by weight of EPDM is a reason that if the ethylene content is less than 50% by weight, the tensile strength of the insulator decreases, and
If the amount is more than the weight%, the flexibility of the cable is impaired.

[0009] FT carbon black is fine The Fine
rmal Furnace Black and MT carbon black is Merdium Thermal Fu
rnace Black, and it is necessary to use carbon black having an average particle size of 90 to 500 μm. By using carbon black having such a large particle size, it becomes difficult to coagulate, so that the dielectric breakdown strength can be increased. The compounding amount of carbon black is in the range of 0.1 to 1.0 part by weight with respect to 100 parts by weight of EPDM. If the amount is less than 0.1 part by weight, the dielectric breakdown strength cannot be improved. Is exceeded, the carbon black migrates to the shielding layer or the sheath and changes the color to black.

MVT is compounded to prevent the appearance of the high-voltage insulator from deteriorating.
If the amount is not more than 50 parts by weight with respect to 00 parts by weight, the effect of preventing appearance deterioration is not exhibited. The upper limit is about 100 parts by weight in consideration of extrusion processability.

Hereinafter, examples of the present invention will be described together with comparative examples. (Example 1) 100 parts by weight of EPDM having an ethylene content of 58% by weight, 0.9 parts by weight of MT carbon black having an average particle diameter of 500 µm, 60 parts by weight of MVT, and other additives such as a crosslinking agent. Semiconducting layer 6 containing resin composition
Extrusion coating on the outer periphery of the high pressure insulator 7
And an X-ray cable having an outer diameter of 16.6 mm was manufactured. (Example 2) 100 parts by weight of EPDM having an ethylene content of 58% by weight, 0.9 parts by weight of FT carbon black having an average particle diameter of 200 µm, 60 parts by weight of MVT, and other additives such as a crosslinking agent were used. Semiconducting layer 6 containing resin composition
Extrusion coating on the outer periphery of the high pressure insulator 7
And an X-ray cable having an outer diameter of 16.6 mm was manufactured. Example 3 100 parts by weight of EPDM having an ethylene content of 58% by weight, 0.9 parts by weight of FT carbon black having an average particle diameter of 200 μm, 90 parts by weight of MVT, and other additives such as a crosslinking agent Semiconducting layer 6 containing resin composition
Extrusion coating on the outer periphery of the high pressure insulator 7
And an X-ray cable having an outer diameter of 16.6 mm was manufactured. (Example 4) 100 parts by weight of EPDM having an ethylene content of 58% by weight, 0.9 parts by weight of FT carbon black having an average particle size of 90 μm, 60 parts by weight of MVT, and other additives such as a crosslinking agent. The resin composition contained was extrusion-coated on the outer periphery of the semiconductive layer 6 and then heat-crosslinked to form a high-pressure insulator 7, thereby producing an X-ray cable having an outer diameter of 16.6 mm. (Example 5) 100 parts by weight of EPDM having an ethylene content of 58% by weight, 0.4 parts by weight of FT carbon black having an average particle diameter of 200 µm, 60 parts by weight of MVT, and other additives such as a cross-linking agent. Semiconducting layer 6 containing resin composition
Extrusion coating on the outer periphery of the high pressure insulator 7
And an X-ray cable having an outer diameter of 16.6 mm was manufactured. Example 6 100 parts by weight of EPDM having an ethylene content of 52% by weight, 0.9 parts by weight of FT carbon black having an average particle diameter of 200 μm, 60 parts by weight of MVT, and other additives such as a crosslinking agent were added. Semiconducting layer 6 containing resin composition
Extrusion coating on the outer periphery of the high pressure insulator 7
And an X-ray cable having an outer diameter of 16.6 mm was manufactured. (Comparative Example 1) 100 parts by weight of EPDM having an ethylene content of 58% by weight, 0.9 parts by weight of FEF carbon black having an average particle size of 40 μm, 60 parts by weight of MVT, and other additives such as a crosslinking agent were used. Semiconducting layer 6 containing resin composition
Extrusion coating on the outer periphery of the high pressure insulator 7
And an X-ray cable having an outer diameter of 16.6 mm was manufactured. (Comparative Example 2) 100 parts by weight of EPDM having an ethylene content of 58% by weight, 2.8 parts by weight of FEF carbon black having an average particle size of 200 µm, 60 parts by weight of MVT, and other additives such as a cross-linking agent. The resin composition contained was extrusion-coated on the outer periphery of the semiconductive layer 6 and then heat-crosslinked to form a high-pressure insulator 7, thereby producing an X-ray cable having an outer diameter of 16.6 mm. Comparative Example 3 100 parts by weight of EPDM having an ethylene content of 45% by weight, 0.9 parts by weight of FT carbon black having an average particle diameter of 200 μm, 60 parts by weight of MVT, and other additives such as a crosslinking agent. Semiconducting layer 6 containing resin composition
Extrusion coating on the outer periphery of the high pressure insulator 7
And an X-ray cable having an outer diameter of 16.6 mm was manufactured. (Comparative Example 4) 1 EPR having an ethylene content of 70% by weight
The resin composition containing 00 parts by weight, 0.9 parts by weight of FT carbon black having an average particle diameter of 200 μm, 60 parts by weight of MVT, and other additives such as a crosslinking agent is extrusion-coated on the outer periphery of the semiconductive layer 6. Then, it was heated and crosslinked to form a high-voltage insulator 7, and an X-ray cable having an outer diameter of 16.6 mm was manufactured.

Table 1 shows the evaluation results of the compositions and properties of Examples 1 to 6 and Comparative Examples 1 to 4. Example 2
FIG. 2 shows the results of evaluating the flexibility of the X-ray cables of Comparative Examples 3 and 6 and Comparative Examples 1 and 4. Evaluation of characteristics was performed based on the following.

According to JIS C 3
005-18.

The dielectric strength was measured by applying a DC voltage of 120 kV, which is a withstand voltage specified in JIS C 3407, for 10 minutes, then increasing the voltage by 10 kV every minute, and continuing increasing the voltage until the cable was broken down. . When the breakdown voltage exceeded 280 kV, it was judged as ○, when it was 200 kV to 280 kV, it was judged as Δ, and when it was less than 200 kV, it was judged as ×.

The hardness of the high-voltage insulator is determined according to JIS K6301.
(A type testing machine).

For flexibility, the amount of flexure of the cable was measured. As shown in FIG. 3, the amount of deflection was measured by measuring a distance X from an initial value when one side of the cable C was fixed to the fixing base 10 and a load 11 was applied to the opposite side.

[0017]

[Table 1]

[0018]

As described above, according to the present invention, an X-ray cable having excellent dielectric breakdown characteristics and excellent mechanical characteristics can be realized.

[Brief description of the drawings]

FIG. 1 is an explanatory sectional view of an embodiment of an X-ray cable according to the present invention.

FIG. 2 is an explanatory diagram showing evaluation results of the flexibility of an X-ray cable.

FIG. 3 is a schematic explanatory view of a method for measuring the amount of deflection.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conductor 2 Insulator 3 Insulated wire 4 Bare conductor 5 Core 6 Semiconductive layer 7 High voltage insulator

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 4J002 BB151 DA036 DJ047 FA086 GB00 GQ01 5G305 AA02 AB02 BA15 CA47 CC20 DA16

Claims (1)

[Claims] An FT carbon black having an average particle diameter of 90 to 500 μm or an MT carbon black having an average particle diameter of 90 to 500 μm is used as an ethylene propylene diene terpolymer having an ethylene content of 50 to 60% by weight. 0.1 to 1.0 parts by weight and 5 parts of Mistron Vapor Talc
An X-ray cable characterized in that a high-voltage insulator is formed from a resin composition containing 0 parts by weight or more.