JP2003223818A - Portable power cable - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a portable power cable which has a high wear resistance for its sheath, can easily be handled due to light weight, is recyclable, and generates no gases including hazardous halogens upon disposal. <P>SOLUTION: The sheath 7 of the portable power cable is composed of an olefinic thermoplastic elastomer. The olefinic thermoplastic elastomer has hard segments of polypropylene or polyethylene and soft segments of an olefinic rubber. Preferably, fine particles of the olefinic rubber as soft segments are dispersed uniformly in the matrix of polyethylene as hard segments. The waterproofing of the terminating portions of the portable power cable may be constituted of a similar olefinic thermoplastic elastomer, and as a result the water resistance of the terminating portions is improved. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable power cable such as a temporary power cable used for wiring line construction and the like, and more particularly to a wear resistant property thereof.

[0002]

2. Description of the Related Art Conventionally, there is a portable power cable of this type as shown in FIG. In FIG. 1, reference numeral 1 indicates a conductor. On this conductor 1, an inner semiconductive layer 2 made of a semiconductive olefin resin composition, an insulator 3 made of crosslinked polyethylene, an outer semiconductive layer 4 made of a semiconductive olefin resin composition, a copper tape, etc. The shielding layer 5 made of a wound layer of the metal tape, the pressing tape layer 6 wound with the polyester tape, and the sheath 7 are sequentially covered to form a portable power cable.

In such a portable power cable, it is usually wound around a drum or a container for storage, and when it is installed, it is pulled out from this and used after being extended, so that the cable has flexibility. Wear resistance is required.
Therefore, the conductor 1 is made of annealed copper stranded wire having good flexibility, and the sheath 7 is made of cross-linked chloroprene rubber, cross-linked butyl rubber or the like, which has high abrasion resistance.

However, the sheath 7 made of crosslinked rubber
In the case of a portable electric power cable having the above, the wear resistance of the crosslinked rubber cannot be said to be sufficient, and especially in a severe working environment or 50 to
Wear resistance is unsatisfactory when used at a high temperature of 60 ° C,
There is a problem that the sheath 7 is worn away as it is used. Further, the sheath 7 made of cross-linked rubber has a problem that the cable is heavy and the handleability is poor.

Furthermore, since the cross-linked rubber forming the sheath 7 is cross-linked and not thermoplastic, the sheath 7 cannot be separated, re-molded and reused when the cable is disposed of, There is also an inconvenience that it cannot be recycled. In addition, the portable power cable having the sheath 7 made of crosslinked chloroprene rubber has a problem that harmful halogen-containing gas is generated when the sheath 7 is incinerated when the cable is discarded.

[0006]

SUMMARY OF THE INVENTION Therefore, an object of the present invention is that the sheath has high abrasion resistance, the sheath is lightweight, the cable can be easily handled, the sheath can be recycled, and the sheath is incinerated. Is to obtain a portable power cable that does not generate harmful halogen-containing gas.

[0007]

In order to solve this problem, the invention according to claim 1 is a portable power cable whose sheath is made of an olefinic thermoplastic elastomer. The invention according to claim 2 is the portable power cable according to claim 1, wherein the olefin-based thermoplastic elastomer has a hard segment of polypropylene or polyethylene and a soft segment of olefin rubber. The invention according to claim 3 is the portable power cable according to claim 1 or 2, wherein the sheath has a multicolor multilayer structure. The invention according to claim 4 is the portable power cable according to claim 1, 2 or 3, wherein a part of the uppermost portion of the sheath is colored in a color different from that of the uppermost layer in the longitudinal direction.

According to a fifth aspect of the present invention, the waterproof treatment portion or the insulation treatment portion in the terminal treatment portion of the portable power cable having the sheath made of the olefin thermoplastic elastomer is made of the olefin thermoplastic elastomer. Good. Further, as in the invention according to claim 6, it is preferable to use an olefin-based thermoplastic elastomer having a hard segment of polypropylene or polyethylene and a soft segment of olefin rubber. It is also preferable that the conductor is not exposed from the terminal processing unit as in the invention according to claim 7.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below based on embodiments. The portable power cable of the present invention includes
For example, in the cable having the cross-sectional structure shown in FIG. 1, the outermost sheath 7 is made of an olefinic thermoplastic elastomer.

As the olefinic thermoplastic elastomer used here, one having a hard segment made of polypropylene or polyethylene and a soft segment made of olefin rubber is used. As the olefin rubber forming the soft segment, ethylene propylene rubber, ethylene propylene diene rubber, butyl rubber or the like is used, and may be crosslinked and used. Further, in this olefin-based thermoplastic elastomer, polypropylene or polyethylene of the hard segment serves as a matrix, and fine particles having a particle diameter of 1 μm or less, preferably 0.2 to 0.5 μm of the olefin rubber which is the soft segment are uniformly dispersed in the matrix. It is preferable that it takes the form of

The olefinic thermoplastic elastomer has a Shore hardness of 60 to 90, which varies depending on the amount ratio of the polymer component of the hard segment and the polymer component of the soft segment and the polymer species. The polymerized type produced inside has good quality stability and good physical property uniformity. The melt flow rate of this thermoplastic elastomer is preferably about 0.2 to 10. Specific examples of the olefin-based thermoplastic elastomer that can be preferably used in the present invention include products manufactured by AES Japan Co., Ltd. under the trade name “Santoprene”
Mitsui Chemicals, Inc., trade name "Milastomer" and the like.

The thickness of the sheath 7 made of an olefinic thermoplastic elastomer is not particularly limited, but is usually 1-2.
It is about 0 mm. Since the olefinic thermoplastic elastomer is thermoplastic, the sheath 7 is formed by extrusion coating on the pressing tape layer 6 by a usual extrusion coating method.

In such a portable power cable, since the olefinic thermoplastic elastomer is used for the sheath 7, the wear resistance is improved and, as will be apparent from the specific examples described later, conventional crosslinked rubber is used. It is about 2 times higher at room temperature and about 4 times higher at 60 ° C. than the one using the sheath.

Further, since the olefinic thermoplastic elastomer is easy to be colored, the sheath 7 has a multicolored multi-layered structure so that the color is changed by abrasion and the abrasion degree can be easily detected from the outside. It is also possible. At the same time, by coloring a part of the uppermost layer of the sheath 7 in a color different from that of the uppermost layer in the longitudinal direction of the cable,
It is also possible to prevent accidents due to incorrect connections by providing color-coded bands for phase confirmation. Further, by adopting the olefinic thermoplastic elastomer having a low specific gravity, the weight can be reduced by about 15% as compared with the one using the conventional crosslinked rubber, and the workability and the portability are improved.

Further, since the olefinic thermoplastic elastomer is thermoplastic, it becomes possible to separately collect the sheath 7 and recycle it when the cable is discarded.
Further, when the sheath 7 is incinerated, since the halogen element such as chlorine is not contained in the olefin-based thermoplastic elastomer, harmful halogen-containing gas such as dioxin is not generated.

FIG. 2 shows an example of the terminal processing unit of the portable power cable of the present invention. Reference numeral 11 in the figure denotes a sheath of the portable power cable. This sheath 11 is the sheath 7 in the portable power cable shown in FIG. Further, reference numeral 12 is a shielding layer of the portable power cable,
13 is also an insulator of the portable power cable, and 14
Are conductors, which are the end portions of the shield layer 5, the insulator 3 and the conductor 1 of the portable power cable described above.

Further, reference numeral 15 is a waterproof processing portion, and 16 is an electrical insulating portion. Both the waterproofing portion 15 and the electric insulating portion 16 are made of the above-mentioned olefinic thermoplastic elastomer. The waterproofing portion 15 has a substantially cylindrical outer shape, and covers the sheath 11, the shielding layer 12, and the electrical insulating portion 16 of the portable power cable.
Further, the electrical insulating portion 16 has a cylindrical outer shape and one end in the longitudinal direction thereof is formed in a tapered shape so as to cover the conductor 14 and the insulator 13. Further, the terminal portion of the conductor 14 is not exposed from the cable terminal portion. Therefore, even if the cable connecting portion is accidentally pulled out during charging or the like, an electric shock hazard does not occur, and the work can be performed safely and at ease.

The waterproofing section 15 and the electrical insulation section 16
Is formed by an ordinary injection molding method, and the waterproofing portion 15 is well adhered and integrated with the sheath 11 during this injection molding to exhibit high waterproofness.

In the terminal treatment section of the portable electric power cable having such a structure, the waterproof treatment section 15 which surrounds most of the outer circumference is made of the olefinic thermoplastic elastomer. The same action and effect as the cable can be obtained, and high waterproofness is exhibited. Even if rainwater or the like is splashed on the terminal processing unit, water such as rainwater does not enter the inside.

Specific examples will be shown below. A portable power cable having the structure shown in FIG. 1 was produced. At that time, as a material forming the sheath 7, a material using an olefinic thermoplastic elastomer (manufactured by AES Japan Co., Ltd., trade name “Santoprene”) and a conventional crosslinked chloroprene rubber (rubber 40
wt%, filler 55 wt%, process oil, etc. 5 wt%
%) Was used to prepare two types. The thickness of the sheath 7 was 2.5 mm.

Regarding these two types of portable power cables,
The wear resistance at room temperature and 60 ° C. was evaluated. Wear resistance, place the cable on a commercial concrete block,
The abrasion resistance was evaluated by reciprocating the cable a certain number of times while applying a load 5 times the weight of the cable from above the cable and measuring the amount of abrasion of the sheath 7. The reciprocating speed was such that the cable was reciprocated 60 times per minute and the reciprocating stroke was 100 mm. The results are shown in Table 1.

[0022]

[Table 1]

The results in Table 1 are shown as relative values when the amount of wear of a cable having a sheath made of conventional crosslinked chloroprene rubber at room temperature is 100. From the results shown in Table 1, it can be seen that the cable having the sheath made of the olefinic thermoplastic elastomer has extremely good wear resistance as compared with the conventional one, especially at high temperatures.

[0024]

As described above, since the sheath of the portable power cable of the present invention is made of the olefinic thermoplastic elastomer, its wear resistance is significantly improved and the conventional crosslinked rubber is not used. It is about 2 times higher at room temperature and about 4 times higher at 60 ° C. than the one using the sheath.

Further, the sheath can have a multicolored multi-layered structure so that the color changes due to abrasion, and the degree of abrasion can be easily detected from the outside. Also, by coloring a part of the uppermost layer of the sheath in a different color from the uppermost layer in the longitudinal direction of the cable to provide a color band for phase confirmation, accidents due to incorrect connection can be prevented. It is also possible. Further, the weight is reduced by about 15% as compared with the conventional one using the crosslinked rubber, and the workability and the portability are improved. Furthermore, it becomes possible to separately collect and recycle the sheath when disposing of the cable. further,
When the sheath is incinerated, since the halogen element is not contained in the olefinic thermoplastic elastomer, no harmful halogen-containing gas is generated.

Further, since the waterproofing portion or the electrical insulating portion of the terminal treatment portion of the portable power cable of the present invention is made of an olefinic thermoplastic elastomer,
It will be highly waterproof. Also, the conductor's terminal part is not exposed from the cable end part, so even if you accidentally pull out the cable connection part during charging, you will not get an electric shock hazard, and you can be safe and secure. Can do the work.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view showing an example of a portable power cable according to the present invention.

FIG. 2 is a schematic cross-sectional view showing an example of a terminal processing unit of the portable power cable of the present invention.

[Explanation of symbols]

7 ... Sheath, 15 ... Waterproof processing part, 16 ... Electrical insulation part.

Front page continuation (51) Int.Cl. ⁷ identification code FI theme code (reference) H01B 7/36 H01B 7/18 B H02G 1/06 501 7/28 E (72) Inventor Masaaki Tomari Kiba, Koto-ku, Tokyo 1-chome 5-1 Fujikura F-term in stock company (reference) 5G311 AA04 AC02 AD03 5G313 AB03 AC07 AE02 FA01 FB07 FD02 5G315 BA14 JA02 JB04 JC02

Claims (7)

[Claims] 1. A portable power cable whose sheath is made of an olefinic thermoplastic elastomer. 2. The portable power cable according to claim 1, wherein the olefin-based thermoplastic elastomer has a polypropylene or polyethylene hard segment and an olefin rubber soft segment. 3. The portable power cable according to claim 1, wherein the sheath has a multicolored multilayer structure. 4. The portable power cable according to claim 1, 2 or 3, wherein a part of the uppermost portion of the sheath is colored in a color different from that of the uppermost layer in the longitudinal direction. 5. A terminal treatment portion of a portable power cable, wherein a waterproof treatment portion or an insulation treatment portion of a terminal treatment portion of a portable power cable having a sheath made of an olefin thermoplastic elastomer is made of an olefin thermoplastic elastomer. 6. The terminal treatment section for a portable power cable according to claim 5, wherein the olefin thermoplastic elastomer has a polypropylene or polyethylene hard segment and an olefin rubber soft segment. 7. The end treatment unit of the portable power cable according to claim 5, wherein the terminal of the conductor is not exposed from the end treatment unit.