JP2700967B2 - Laminated sheath optical fiber cable and laminated sheath cable - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated sheath cable, such as a communication cable or a power cable, in which a laminated tape having a metal layer is provided on the outer periphery of a cable core.

[0002]

2. Description of the Related Art Conventionally, as a cable of this type, for example, as shown in FIG. 5, a cable core 11 having a glass optical fiber 11a and a metal coated on the outer periphery of the cable core 11 and having an ionization tendency larger than hydrogen, for example, as shown in FIG. Known is one that includes a tubular laminated tape 3 having a metal layer 30 made of aluminum, and a resin sheath 4 made of polyethylene or the like coated on the outer periphery of the laminated tape 3. Desirably, the outer periphery of the cable core 11 is covered with an upper winding tape, for example, a water-absorbing tape 2 made of a polyester nonwoven fabric containing a water-absorbing substance. The water-absorbing tape 2 absorbs water that enters inside due to some obstacle, thereby suppressing water permeation in the longitudinal direction.

As shown in FIG. 4, the laminating tape 3 includes a metal layer 30 made of a thin aluminum plate, and fusion resin layers 311, 312 made of a polyolefin resin laminated on both sides of the metal layer 30. The laminating tape 3 is formed in a tubular shape with its both ends in the width direction overlapped in the longitudinal direction, and the cable core 1 is housed inside the laminating tape 3. The fusion resin layers 311 and 31 are heated by heat during molding.
2 are melted and the end portions 31a of the fusion layer 312 overlapped with each other.
Then, the end 31b of the fusion layer 311 is solidified to be bonded and joined.

By arranging the laminating tape 3 in this way, it is possible to prevent moisture in the cable and water from the outside from coming into direct contact with the metal layer 30 by the fusion resin layers 311, 312, To prevent corrosion. Also, in addition to this optical fiber, a water-absorbing tape is applied to the outer periphery of a cable core in which conductors such as soft copper wires are assembled in the same manner as the above-described optical fiber, and the outer periphery of the water-absorbing tape is covered with a laminate tape. There is known a laminated sheath cable in which the outer periphery is covered with a sheath such as polyethylene.

[0005]

However, after cooling after covering with the sheath 4 as described above, the fusion layer 312 adheres to the cable core 1 or the water-absorbing tape 2 of the cable core 1. For this reason, in this cable, the cable core 1 is hard to slip inside, and the flexibility is insufficient, which is not sufficiently satisfactory in the laying work.
It has also been difficult to remove the covering portion of the cable end.

In order to solve such a disadvantage, for example, a polyolefin resin layer is bonded to one surface of the metal layer (the side facing the sheath), and urethane is bonded to the other surface of the metal layer (the side facing the cable core). It is also possible to use a laminate tape in which a polyester layer is laminated via a system resin layer. In this case, it is known that even when heat is applied to cover the sheath, the inner peripheral layer facing the cable core does not melt, and the cable after cooling has sufficient flexibility. Are in. However, in such an optical fiber cable, the adhesive force of the urethane resin layer is weakened by moisture in the cable, the polyester layer is peeled off from the urethane resin layer, and moisture contacts the metal layer,
The metal layer is oxidized to generate hydrogen gas, and this hydrogen gas reacts with SiO ₂ of the glass component of the optical fiber to generate an OH group, thereby generating an absorption peak in the 1.3 μm band used for transmission and transmitting. There is a problem of causing obstacles.

[0007] Also, in a laminated sheath cable having a cable core formed by assembling metal conductors,
When the polyester layer is bonded to the metal layer of the laminate tape on the side facing the cable core via the urethane resin layer, the moisture in the cable weakens the adhesive strength of the urethane resin layer, and the polyester layer becomes urethane resin. Moisture comes off from the layer and comes into contact with the metal layer, and the metal layer is corroded at an early stage, the withstand voltage characteristic is deteriorated, and the life of the laminated sheath cable is shortened.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and when a sheath is formed, a cable core can be firmly maintained. It can prevent sticking to the cable core, is excellent in flexibility, can easily remove the coating on the cable end, and can prevent transmission failure due to water in the optical fiber cable. It is an object of the present invention to provide a cable having a core, which is capable of maintaining a withstand voltage for a long period of time and having excellent durability.

[0009]

A first means is a cable core formed by assembling optical fibers made of glass, a laminate tape covering the outer periphery of the cable core, and covering the outer periphery of the laminate tape. A laminated sheath optical fiber cable having a sheath, wherein the laminated tape comprises a metal layer made of a metal having a higher ionization tendency than hydrogen, and a first water resistant adhesive bonded to at least a side of the metal layer facing the sheath. And a second adhesive layer bonded to at least a side of the metal layer facing the cable core.
And a hard-to-fusion resin layer having a melting point higher than the melting point of the second water-resistant fusion resin layer bonded through the second water-resistant fusion resin layer. It is characterized by the following.

The cable core is formed by assembling a plurality of glass optical fibers for optical communication. As the cable, preferably, the outer periphery of the cable core is covered with a water-absorbing tape, for example, as an upper winding tape. In the laminate tape, the first water-resistant fusion resin layer is laminated on one surface (the side facing the sheath) of the metal layer, and the second water-resistant fusion resin layer is laminated on the other surface (the side facing the cable core). The hard-to-fuse resin layer is laminated via the resin layer.

As the metal layer, a thin plate of aluminum-based metal, steel or the like can be used. The thickness of the metal layer is appropriately selected according to the type of the cable. For example, in the case of a metal layer made of aluminum, the thickness is preferably about 50 to 300 μm, particularly about 100 to 200 μm in terms of maintaining the sheath strength and reducing the weight. Is preferred. As the first water-resistant and second water-resistant fusion resin layers adhered to the metal layer, polyethylene, polypropylene, straight polymers such as polybutadiene, and modified polyolefin resins in which some of the olefin monomers are substituted with other monomers are used. A hot melt adhesive composed of a polyolefin resin, polyvinyl acetate, polyamide, phenoxy resin, ethylcellulose, polyester or the like alone or in a mixture can be employed. After laminating the first water-resistant fusion resin layer on one side of the metal layer and the second water-resistant fusion resin layer on the other side,
What is necessary is just to adhere | attach a hard-to-fusion resin layer further to a 2nd water resistant fusion | melting resin layer. The thickness of the second water-resistant fusion resin layer is appropriately selected according to the type of the cable. For example, EVA (ethylene / vinyl acetate copolymer) or EAA (ethylene / vinyl
In the case of a water-resistant fusion resin layer made of an acrylic acid copolymer), the thickness is preferably 10 to 300 μm, particularly preferably 20 to 100 μm, from the viewpoint of light weight and adhesiveness.

[0012] The hardly fusing layer has a melting point higher than that of the second water-resistant fusing resin layer. For example, HDPE (high-density polyethylene) can be used as the hard-to-fusion layer. The thickness of the hard-to-bond layer is appropriately selected according to the type of the cable. For example, in the case of a hard-to-bond layer made of HDPE, the cost and light weight are preferably 10 to 300 μm, particularly 20 to 70 μm. It is preferred in that respect.

The second means is a cable core formed by assembling metal conductors, a water-absorbing tape spirally or vertically wound around the outer periphery of the cable core, and a laminate covering the outer periphery of the water-absorbing tape. A laminated sheath cable having a tape and a resin sheath covering an outer periphery of the laminated tape, wherein the laminated tape faces a metal layer made of a metal having an ionization tendency larger than hydrogen and at least the sheath of the metal layer. A first water-resistant fusion resin layer bonded to the side to be bonded, a second water-resistant fusion resin layer bonded to at least a side of the metal layer facing the cable core, and the second water resistance. A laminated sheath cable comprising: a hardly-fusible resin layer having a melting point higher than the melting point of the second water-resistant fused resin layer adhered through the fused resin layer. Than it is.

This laminated sheath cable is the same as the above-described optical fiber cable, except that a cable core formed by assembling glass optical fibers is replaced with a cable core formed by assembling metal conductors. Can be configured by arranging a water-absorbing tape spirally or vertically wrapped around the outer periphery.

[0015]

In each of the optical fiber cable and the laminated sheathed cable of the present invention, at least the side facing the cable core has a hard-to-fusion resin layer having a melting point higher than the melting point of the second water-resistant fusion resin layer. Since the laminated tape adhered via the water-resistant fusion resin layer is used, the first water-resistant fusion resin layer and the second water-resistant fusion resin layer are heat-welded and laminated during sheath molding. Even if the tape is formed in a tubular shape, the heat of welding does not cause the hardly-fusible resin layer to be in a molten state, and the adhesive between the hardly-fusible layer and the upper winding tape or the cable core when the upper winding tape is not applied. Adhesion is prevented.

The side of the metal layer facing the sheath is the first side.
And the side facing the cable core is adhesively covered with the second water-resistant fusion resin layer. The tape is integrated, so that the cable core can be maintained firmly, and since both surfaces of the metal layer are adhesively coated with these water-resistant fusion resin layers, they prevent contact with moisture in the cable core and moisture that enters from outside. Even if the metal layer has a higher ionization tendency than hydrogen, it does not corrode and suppresses the generation of hydrogen gas. Further, since the hardly-fusible resin layer is interposed between the second water-resistant fusion resin layer and the cable core, the laminating tape is not integrally fixed to the upper winding tape or the cable core. Sliding occurs between the tape and the tape, and the tape is easily bent.

[0017]

Embodiments of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the following cable employs a cable core 1 entirely covered with a water-absorbing tape 2 as an upper winding tape. (Embodiment 1) This cable is composed of a cable core 1 having a plurality of glass optical fibers 1a,
A water-absorbing tape 2 spirally or vertically wound on the outer periphery of the tape, a laminated tape 5 covering the outer periphery of the water-absorbing tape 2, and a sheath 4 covering the outer periphery of the laminated tape 5.

A water-absorbing tape 2 is wound around the outer periphery of the cable core 1. The water absorbing tape 2 is made of a polyester nonwoven fabric and a chlorine acrylate resin impregnated in the polyester nonwoven fabric. The laminate tape 5 is shown in FIG.
As shown in FIG. 3, a metal layer 50 and a second water-resistant fusion resin layer 5 adhered to both surfaces of the metal layer 50, respectively.
11, first water-resistant fusion resin layer 512 and water-absorbing tape 2
And a hardly-fusible resin layer 52 laminated on the side opposite to the second water-resistant fusion resin layer 511. As the metal layer 50, an aluminum foil (JISA-1050-O material (purity: 99.5%)) is employed. This metal layer 50
Has a thickness of 200 μm. Second water-resistant fusion resin layer 5
11 is Yucalon EAA221 manufactured by Mitsubishi Yuka as EAA.
M (melting point: 80 to 90 ° C.). The thickness of the second water-resistant fusion resin layer 511 is about 25 μm. First
The water-resistant fusion resin layer 512 uses Admer VE300 (melting point: about 80 to 90 ° C.) manufactured by Mitsui Petrochemical as EVA. The thickness of the first water-resistant fusion resin layer 512 is about 50 μm. The hard-to-fusion resin layer 52 is made of Mitsui Petrochemical Hi-Zex 5305E (HD 120) as HDPE.
° C). The thickness of the resin layer 52 is about 50 μm. This laminated tape 5 was manufactured as follows. That is, 200 mm in a heating furnace (not shown).
The metal layer 50 preheated to about ° C. is sent to a heat roller side (not shown), and almost the entire area on both sides of the metal layer 50 is covered with the second and first water-resistant fusion resin layers 511 and 512 with the above thickness. Further, while transporting the metal layer 50 in the longitudinal direction, the hard-to-fuse resin layer 52 rewound from a film roll (not shown) is superimposed on the upper surface of the second water-resistant fusion resin layer 511, and pressed again by the heat roller. I do. Thus, the laminate tape 5 is obtained.

The sheath 4 is made of polyethylene (melting point 110 ° C.)
Consists of This optical fiber cable is manufactured as follows. As shown in FIG. 3, a cable core 1 is formed by twisting a plurality of optical fibers 1a, and then a water-absorbing tape 2 is wound on the outer periphery of the cable core 1, and then a laminate tape 5 is placed on the outer periphery. Tie together. At this time, the cable core 1 is housed inside the laminated tape 5 having the metal layer 50 with both ends in the width direction overlapping in the longitudinal direction, and finally, the sheath 4 is covered to form an optical fiber cable.

At the time of forming the sheath 4, between the second water-resistant fusion resin layer 511 and the water-absorbing tape 2, a hard-fusion-bonding material having a melting point higher than the melting point of the second water-resistance fusion resin layer 511 is formed. Since the resin layer 52 is interposed, even when the sheath 4 is covered in this state, the hardly-fusible resin layer 52 is not melted by the heat at that time. (Embodiment 2) The optical fiber cable of Embodiment 2 is HDP
LDPE (low density polyethylene, Mitsui Petrochemical, Miralin 12 SOBK-40, melting point 103 ° C) instead of E
Other than the point that the laminated tape was manufactured using the optical fiber cable, the optical fiber cable was the same as the optical fiber cable of the first embodiment.

(Embodiment 3) Instead of a plurality of glass optical fibers 1a forming the cable core 1 of the optical fiber cable of the first embodiment, a cable core is formed by assembling a conductor composed of a plurality of copper wires. Except for this point, a laminated sheath cable for communication is constituted by the same water-absorbing tape, laminated tape and sheath as in Example 1.

(Comparative Example) As shown in FIG. 5, an optical fiber cable of a comparative example has the same cable core 1 as in Example 1, a laminate tape 3 coated on the outer periphery of the cable core 1, It comprises the same sheath 4 as in the first embodiment, which is coated on the outer periphery of the tape 3.

The laminating tape 3 is formed in a tubular shape with the fusion resin layers 311 and 312 adhered to both surfaces of the metal layer 30 and joined at the overlapping portions 31a and 31b at both ends in the circumferential direction. This optical fiber cable is the same as the optical fiber cable of the first embodiment except that the laminated tape 3 is not covered with the hardly-fusible resin layer 52.

(Evaluation) (1) Using the cables of Example 1 and Comparative Example,
The peeling test was performed at a speed of 100 mm / min.
In the cable of Example 1 shown in FIG. 3, the metal layer 50 of the laminate tape 5 via the second water-resistant fusion resin layer 511 is provided.
The peel strength between the resin layer 52 and the hardly-fusible resin layer 52 is at least 0.625 kg / cm, the peel strength between the sheath 4 and the metal layer 50 via the first water-resistant fusion resin layer 512 is at least 5.0 kg / cm, Peel strength between the metal layers 50, 50 via the second water-resistant fusion resin layer 511 a, the hard-fusion resin layer 52 a, and the first water-resistance fusion resin layer 512 a at the overlapping portion of the laminate tape 5 Was 4.0 kg / cm or more. However, since the hardly-fusible resin layer 52 and the water-absorbing tape 2 were not substantially adhered, they were easily peeled off and required little force.

On the other hand, in the cable of the comparative example shown in FIG. 5, the peel strength between the sheath 4 and the metal layer 30 via the first water-resistant fusion resin layer 311 was 2.0 kg / cm or more. The peel strength between the metal layer 30 and the water-absorbing tape 2 via the fusion layer 312 was 1 kg / cm or more. (2) Using the cables of Example 1 and Comparative Example, a bending test was performed 10 times or more at room temperature to bend from a linear state to a radius of 10 × D (D is the outer diameter of the cable).

The optical fiber cable of Example 1 had good flexibility. On the other hand, the cable of the comparative example had bellows-like wrinkles on the outer peripheral portion of the cable, and was not sufficiently flexible. (3) Regarding the optical fiber cable of the second embodiment, (1)
When the tests of (2) to (2) were performed, almost the same characteristics as in Example 1 were obtained. (4) Regarding the laminated sheath cable of Example 3,
When the tests (1) and (2) were performed, almost the same characteristics as those of the example were obtained.

According to the evaluations of (1) to (4), the cables of Examples 1, 2 and 3 did not have the laminated tape adhered to the water-absorbing tape as compared with the optical fiber cable of the comparative example, and the cables were bent. Then, it was found that the cable core had good flexibility because the cable core slipped inside and the expansion and contraction stress of the jacket did not concentrate locally. Further, in the cables of Examples 1, 2 and 3, it is understood that the cable core is covered with the sheath of the laminate tape, the laminate tape and the sheath are well bonded, and the cable core can be firmly maintained.

In addition, in the optical fiber cables of Examples 1 and 2, the fusion resin layers adhered to both surfaces of the metal layer are excellent in water resistance. The generated water does not come into contact with the metal layer and does not generate hydrogen gas. Therefore, when the second water-resistant fusion resin layer is provided, the amount of hydrogen generated can be reduced to about 1/1000 or less as compared with the case without the second water-resistant fusion resin layer, and transmission failure due to water can be effectively prevented with these optical fiber cables. I understood.

Further, in the laminated sheath cable of the third embodiment, similarly to the optical fiber cables of the first and second embodiments,
Since the water entering the cable and the water entering from the outside do not come into contact with the metal layer, the corrosion of the metal layer can be prevented for a long time, and the withstand voltage characteristic does not deteriorate. In the present invention, a polyester (melting point: about 250 ° C.) of 5 to 100 μm is used as the hard-to-fusion resin layer instead of HDPE, and the EVC is replaced with EAA for the second water-resistant fusion resin layer.
A configuration in which various changes are made based on the knowledge of those skilled in the art can be made without departing from the spirit of the present invention, such as adoption of A20 to 100 μm.

[0030]

As described in detail above, according to the present invention,
While the cable core can be firmly maintained when forming the sheath,
It is possible to prevent the adhesion of the metal layer and the water-absorbing tape and the cable core or the adhesion of the metal layer and the cable core, and it is excellent in flexibility and can be easily laid. The work of removing the coating on the end can be easily performed.Furthermore, in the case of optical fiber bull, transmission failure due to water can be prevented,
In a laminated sheath cable having a cable core made of a metal conductor, the withstand voltage can be maintained for a long time.

[Brief description of the drawings]

FIG. 1 is a sectional view of a cable according to an embodiment.

FIG. 2 is a cross-sectional view of a laminate tape according to the cable of the example.

FIG. 3 is an enlarged cross-sectional view of the cable according to the embodiment.

FIG. 4 is a sectional view of a laminate tape according to a conventional cable.

FIG. 5 is an enlarged sectional view of a conventional cable.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Cable core 2 ... Water absorption tape 4 ... Sheath 5 ... Laminate tape 50 ... Metal layer 511 ... Second water resistant fusion bonding resin layer 52 ... Hard fusion bonding layer 512 ... First water resistant fusion bonding resin layer

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Kazuo Hokari 1-6-1, Uchisaiwaicho, Chiyoda-ku, Tokyo Nippon Telegraph and Telephone Corporation (72) Inventor Hiroshi Baba 1-chome Taya-cho, Sakae-ku, Yokohama, Kanagawa Prefecture Sumitomo Electric Industries, Ltd. Inside Yokohama Works

Claims (2)

(57) [Claims] 1. A laminated sheath optical fiber cable having a cable core formed by assembling glass optical fibers, a laminated tape covering the outer periphery of the cable core, and a resin sheath covering the outer periphery of the laminated tape. The laminate tape comprises a metal layer made of a metal having an ionization tendency larger than hydrogen, a first water-resistant fusion resin layer adhered to at least a side of the metal layer facing the sheath, A second water-resistant fusion resin layer adhered to at least a side of the layer facing the cable core, and the second water-resistant fusion resin adhered via the second water-resistant fusion resin layer A laminated sheath optical fiber cable comprising a hard-to-fusion resin layer having a melting point higher than the melting point of the layer. 2. A cable core formed by assembling metal conductors; a water-absorbing tape spirally or vertically wound around the outer periphery of the cable core; a laminate tape covering the outer periphery of the water-absorbing tape; A laminated sheath cable having a resin sheath covering the outer periphery of a laminated tape, wherein the laminated tape is bonded to a metal layer made of a metal having an ionization tendency larger than hydrogen and at least a side of the metal layer facing the sheath. A first water-resistant fusion resin layer, a second water-resistant fusion resin layer adhered to at least a side of the metal layer facing the cable core, and a second water-resistant fusion resin layer And a hard-to-fusion resin layer having a melting point higher than the melting point of the second water-resistant fusion resin layer adhered through the laminate sheath cable.