JP2021157175A - Coated optical fiber conjugation tape and optical fiber cable - Google Patents

Abstract

To provide a coated optical fiber conjugation tape capable of avoiding breakage even at a high dice temperature or melting beyond necessity, and an optical fiber cable using the same.SOLUTION: A coated optical fiber conjugation tape 1 is formed of a tape-shaped sea component resin 2 consisting of a thermoplastic resin and a fibrous island component resin 3 dispersed in a state arranged in parallel in the sea component resin 2 and consisting of a thermoplastic resin. The melting point of the sea component resin 2 is more than 150°C and 230°C or less, and the melting point of the island component resin 3 is 200°C or more and 260°C or less and is higher by 20°C or more than the melting point of the sea component resin 2. An optical fiber cable 10 is formed by covering an optical fiber bundle 12 formed by directly winding the coated optical fiber conjugation tape 1 around a predetermined number of coated optical fibers 11 with a sheath 13.SELECTED DRAWING: Figure 2

Description

The present invention relates to an optical fiber core wire ligation tape for directly winding around an optical fiber core wire and bundling them, and an optical fiber cable using the tape.

As the structure of the optical fiber cable, cables using resin slots (also referred to as slot rods, spacers, etc.) have been the mainstream until now (see, for example, Patent Document 1 and the like).
In such an optical fiber cable, the optical fibers are arranged at a predetermined slot position, such as passing the optical fiber through a groove provided on the outer peripheral surface of the slot or a tube fixed in the slot.

However, in recent years, in order to arrange as many optical fibers as possible in one optical fiber cable, the optical fiber core wire ligation tape is directly wound around a plurality of optical fiber core wires and bundled without using a slot. , Optical fiber cables in which bundled ones are twisted together or twisted ones are further twisted and coated with a sheath have been put into practical use (see Patent Documents 2 and 3).
In such an optical fiber cable, the position of the optical fiber in the cable is not fixed as in the case of the slot type cable described above, so that, for example, the optical fiber core wire that bundles the optical fiber core wires is bundled. Ingenuity has been made such as distinguishing bundles of optical fiber core wires by coloring the conjugating tape in a different color for each tape.

At that time, the optical fiber core wire conjugation tape is configured so that, for example, the fibrous island component resin is dispersed in parallel in the tape-shaped sea component resin.
Then, for example, two optical fiber core wire conjugating tapes are spirally wound around a bundle of a plurality of optical fiber core wires in opposite directions from the outside (that is, the two optical fiber core wire conjugating tapes cycle. Bundle multiple optical fiber core wires by winding them in a spiral so that they intersect with each other.

Japanese Unexamined Patent Publication No. 2008-139635 Japanese Patent No. 5707539 Japanese Patent No. 5852806

By the way, for example, when forming a sheath by extrusion molding a twisted optical fiber core wire or the like, if the die temperature is high, the optical fiber core wire ligation tape that bundles the optical fiber core wire may break or light may be generated. Problems such as the sea component resin of the fiber core wire conjugation tape leaching out more than necessary, contaminating the optical fiber core wire, and reducing the end processability when the optical fiber core wire is taken out from the optical fiber cable. Occurs.
Therefore, it is necessary to set the die temperature at the time of extrusion molding to a temperature at which the optical fiber core wire ligation tape does not break or the sea component resin does not melt more than necessary.

However, in the optical fiber core wire ligation tapes (optical fiber unit conjugation fibers) described in Patent Documents 2 and 3, the die temperature must be lowered because the melting point of the sea component resin is low, and therefore, as a sheath. The resins that can be used have been limited to those that melt at such low die temperatures.

The present invention has been made in view of the above problems, and is an optical fiber core wire conjugation tape having excellent manufacturability that does not break or melt more than necessary even at a high die temperature during the manufacture of an optical fiber cable. The purpose is to provide. Another object of the present invention is to provide an optical fiber cable having excellent terminal processability using such an optical fiber core wire ligation tape.

In order to solve the above problem, the invention according to claim 1 is used in an optical fiber core wire conjugation tape.
It is formed of a tape-shaped sea component resin made of a thermoplastic resin and a fibrous island component resin made of a thermoplastic resin dispersed in the sea component resin in parallel.
The melting point of the sea component resin is larger than 150 ° C. and 230 ° C. or lower.
The island component resin has a melting point of 200 ° C. or higher and 260 ° C. or lower, and is 20 ° C. or higher higher than the melting point of the sea component resin.

The invention according to claim 2 is characterized in that the optical fiber core wire conjugation tape according to claim 1 has a tensile elastic modulus of 4000 to 10000 [MPa].

According to the third aspect of the present invention, in the optical fiber core wire conjugation tape according to the first or second aspect, the sea component resin is a polyester copolymer and the island component resin is polyethylene terephthalate. It is characterized by.

According to the invention of claim 4, in the optical fiber core wire conjugation tape according to any one of claims 1 to 3, the diameter of the island component resin is 10 to 60 [μm]. It is a feature.

According to the fifth aspect of the present invention, in an optical fiber cable, the optical fiber core wire ligation tape according to any one of claims 1 to 4 is directly wound around a predetermined number of optical fiber core wires. It is characterized in that the formed optical fiber bundle is covered with a sheath.

According to the present invention, it is possible to make an optical fiber core wire ligation tape excellent in manufacturability without breaking or melting more than necessary even at a high die temperature during manufacturing of an optical fiber cable. Further, by using such an optical fiber core wire ligation tape, it becomes possible to make the optical fiber cable excellent in terminal processability.

It is a figure which shows the structural example of the optical fiber cable which concerns on this embodiment. It is a figure which shows the structure of the optical fiber core wire conjugation tape which concerns on this embodiment. It is a figure which shows the example of the tape wire which coated the fibrous island component resin with the sea component resin.

Hereinafter, the optical fiber core wire ligation tape and the optical fiber cable according to the present invention will be described with reference to the drawings.
However, although the embodiments described below are provided with various technically preferable limitations for carrying out the present invention, the scope of the present invention is not limited to the following embodiments and illustrated examples.

[Optical fiber cable configuration]
FIG. 1 is a diagram showing a configuration example of an optical fiber cable according to the present embodiment.
In the present embodiment, as shown in FIG. 1, the optical fiber cable 10 is formed by directly winding an optical fiber core wire conjugating tape 1 around a predetermined number of optical fiber core wires 11 and bundling them to form an optical fiber core wire conjugating tape. The bundle 12 of the optical fiber core wires 11 bundled in 1 (hereinafter, this is referred to as an optical fiber bundle 12) is twisted with each other and covered with a sheath 13.

In the present embodiment, the two optical fiber core wire conjugating tapes 1 are spirally wound around the optical fiber core wire 11, and the two optical fibers are spirally wound in opposite directions to each other. The core wire conjugation tape 1 is designed to intersect periodically.
The two optical fiber core wire conjugation tapes 1 are welded to each other at the intersections.

Also in this embodiment, the color of the optical fiber core wire conjugating tape 1 for bundling the optical fiber core wires 11 is colored differently for each optical fiber core wire conjugating tape 1 or for each optical fiber bundle 12.
In addition, in FIG. 1, when a plurality of optical fiber core wires 11 are bundled to form an optical fiber bundle 12, it is described that the plurality of optical fiber core wires 11 are not twisted. The optical fiber core wire 11 of the book may be twisted and then bundled with the optical fiber core wire ligation tape 1.

Further, in FIG. 1, in order to make the figure easier to see, a case where three optical fiber bundles 12 which are relatively thick with respect to the sheath 13 are included is shown, but there are more thin optical fiber bundles 12. It may be included.
Further, in the optical fiber cable 10, in addition to the optical fiber bundle 12 (optical fiber core wire 11), for example, a tension member or the like is appropriately arranged in the sheath 13.

[Structure of optical fiber core wire conjugation tape, etc.]
Next, the optical fiber core wire conjugation tape 1 according to the present embodiment will be described. FIG. 2 is a diagram showing a configuration of an optical fiber core wire ligation tape according to the present embodiment.
The optical fiber core wire conjugation tape 1 is formed of a tape-shaped sea component resin 2 and a fibrous island component resin 3 dispersed in the sea component resin 2 in parallel.

Both the sea component resin 2 and the island component resin 3 are made of a thermoplastic resin, and the melting point (melting peak temperature; the same applies hereinafter) of the sea component resin 2 is larger than 150 ° C. and 230 ° C. or less, and the melting point of the island component resin 3 Is 200 ° C. or higher and 260 ° C. or lower.
Then, as the island component resin 3, a resin whose melting point is higher than the melting point of the sea component resin 2 by 20 ° C. or more is used.
The melting point is measured using a differential scanning calorimeter (hereinafter, DSC), and the melting point is the endothermic peak obtained from DSC data obtained by measuring 7.0 mg of a sample from room temperature to 300 ° C. under heating conditions of 10 ° C./min. Is the melting peak temperature at which reaches the peak.

Examples of the material of the sea component resin 2 include homopolypropylene, block polypropylene, polyester copolymer and the like, and among them, polyester copolymer is preferably used.
Further, as the material of the island component resin 3, for example, crystalline polypropylene, polyethylene terephthalate and the like can be mentioned, and among them, polyethylene terephthalate is preferably used.
As for the combination of the sea component resin 2 and the island component resin 3, since the combination of the sea component resin 2 as a polyester copolymer and the island component resin 3 as polyethylene terephthalate is compatible with each other, the sea component resin 2 and the island component resin 3 are compatible with each other. Interfacial peeling does not occur in the component resin 3 and the integrity is good, which is preferable from the viewpoint of strength.

In particular, by using a polyester copolymer having high strength as the sea component resin 2, the function can be sufficiently exhibited even if the thickness t (see FIG. 2) of the optical fiber core wire conjugation tape 1 is thinly formed. Will be able to.
Then, when the optical fiber core wire conjugation tape 1 is thinned, more optical fiber core wires 11 can be passed through the optical fiber cable 10 by that amount, and the optical fiber cable 10 can be multi-core. Become.

Further, by using a polyester copolymer having high strength as the sea component resin 2, the width w (see FIG. 2) of the optical fiber core wire conjugation tape 1 can be narrowed, and the optical fiber core wire conjugation tape 1 can be narrowed. It is possible to improve the flexibility of 1.

The method for manufacturing the optical fiber core wire ligation tape 1 can be any method as long as the optical fiber core wire ligation tape 1 can be appropriately manufactured.
For example, as shown in FIG. 3, a predetermined number of tape strands 1a obtained by coating the fibrous island component resin 3 with the sea component resin 2 are focused, and the temperature at which the island component resin 3 does not melt but the sea component resin 2 melts. As shown in FIG. 2, the cross-sectional shape is formed into a rectangular shape of an appropriate size while the sea component resins 2 of the adjacent tape strands 1a are melted and integrated with each other by heating to melt only the sea component resin 2. It is possible to manufacture such an optical fiber core wire ligation tape 1.
Although not shown, for example, a predetermined number of fibrous island component resins 3 are arranged, and molten sea component resin 2 is poured between the fibers of the island component resin 3 or around the fibers by extrusion molding or the like to make an optical fiber. It is also possible to manufacture the core wire conjugation tape 1.
The cross-sectional shape shown in FIG. 3 is an example, and may be a polygon other than a circle, an ellipse, or a hexagon, and is not particularly limited.

The diameter of the island component resin 3 is one factor that determines the rigidity of the optical fiber core wire conjugating tape 1. If the diameter of the island component resin 3 is too small, the rigidity of the optical fiber core wire conjugating tape 1 becomes low. Insufficiently, even if the optical fiber core wire 11 is spirally wound as described above, the optical fiber core wire 11 cannot be properly bundled.
On the contrary, if the diameter of the island component resin 3 is too large, the rigidity of the optical fiber core wire conjugating tape 1 is too strong and the optical fiber core wire conjugating tape 1 is difficult to bend, so that the optical fiber core wire 11 is also appropriate. Can no longer be bundled in.
Therefore, if the diameter of the island component resin 3 is 10 to 60 [μm], the rigidity of the optical fiber core wire ligation tape 1 becomes appropriate, and the above-mentioned problems are less likely to occur.
The diameter of the island component resin 3 was measured by cutting the optical fiber core wire conjugation tape 1 in the cross-sectional direction and measuring the cut surface with an observation image of a microscope. It was confirmed that the diameter of the island component resin 3 was in the range of 10 to 60 [μm] in five different cross sections.

Further, the tensile elastic modulus of the optical fiber core wire conjugation tape 1 is preferably 4000 to 10000 [MPa], and more preferably 6300 to 8000 [MPa] from the viewpoint of binding force and ease of winding. .. The tensile elastic modulus of the optical fiber core wire conjugation tape 1 is such that the optical fiber core wire ligation tape 1 is subjected to a tensile tester (manufactured by Shimadzu Corporation (product number: AGS-J)) with a chuck width of 500 mm and a tensile speed of 500 mm / min. It was measured by pulling it until it broke. The elastic modulus is determined according to the method specified in JIS K7161-1. In the stress-strain curve obtained when the stress is pulled by the tensile tester, the slopes of two points, one where the stress reaches 1N and the other where the stress reaches 5N. And said.
When the tensile elasticity of the optical fiber core wire ligation tape 1 is smaller than 4000 [MPa], the optical fiber core wire ligation tape 1 is likely to stretch, and the optical fiber core wire 11 is easily loosened due to loosening of the conjugation. If the tensile elasticity is greater than 10000 [MPa], the optical fiber core wire conjugating tape 1 is too hard, causing cracks in the optical fiber core wire conjugating tape 1 itself. The problem of damage can occur.

The optical fiber cable 10 can be manufactured, for example, as follows.
That is, the two optical fiber core wire conjugation tapes 1 manufactured as described above are spirally wound around a predetermined number of optical fiber core wires 11 in opposite directions to form an optical fiber bundle 12. It is heated to a predetermined temperature and two two optical fiber core wire conjugating tapes 1 are welded to each other at an intersecting point.
Then, while forming a predetermined number of such optical fiber bundles 12 at the same time, they are twisted together, and a predetermined resin composition is extruded and coated on them to form a sheath 13 to manufacture an optical fiber cable 10. can do.

When manufacturing the optical fiber cable 10 in this way, since the melting point of the sea component resin is low in the conventional optical fiber core wire ligation tape, the optical fiber core wire ligation must be lowered unless the die temperature at the time of forming the sheath 13 is lowered. Problems such as breakage of the tape for use and melting of the sea component resin more than necessary may reduce workability when taking out the optical fiber core wire may occur.
Therefore, as the material of the sheath 13, only a resin that melts even at a low temperature as described above can be used.

However, in the optical fiber core wire conjugation tape 1 according to the present invention, the melting point of the sea component resin 2 is higher than 150 ° C. and as high as 230 ° C. or less, so that when the sheath 13 is formed (that is, when the optical fiber cable 10 is manufactured). Even at a die temperature higher than the conventional one, the optical fiber core wire ligation tape 1 does not break or melt more than necessary.
As a material for the sheath 13, a resin having a relatively high melting point such as nylon can also be used, and the types of resins that can be used as a material for the sheath 13 have been greatly increased, resulting in excellent manufacturability. It has become. That is, even a resin that could not be used as a material for the sheath 13 in the past can be used as a material for the sheath 13 in the optical fiber cable 10 using the optical fiber core wire ligation tape 1 according to the present invention. be.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited thereto.
(Example, comparative example)
As shown in FIG. 3, 144 tape strands obtained by coating a fibrous island component resin with a sea component resin are focused and heated at a predetermined temperature to melt and integrate the sea component resin to form a tape. The strands were fused to each other to prepare an optical fiber core wire conjugation tape.
Further, the two prepared optical fiber core wire conjugation tapes are spirally wound around the twelve optical fiber core wires in opposite directions to prepare twelve optical fiber bundles, and they are twisted together. A predetermined resin composition was extruded and coated on them to form a sheath to prepare an optical fiber cable.

Each of the following evaluation items was evaluated for each optical fiber core wire ligation tape and optical fiber cable obtained in each Example and Comparative Example. The results are shown in the table.

[Evaluation item 1]
The ease of taking out the optical fiber core wire from the optical fiber bundle with the sheath removed was evaluated (terminal workability).
Then, the case where the optical fiber core wire can be easily peeled off was evaluated as ◯, and the case where the optical fiber core wire was attached to each other via the sea component resin of the optical fiber conjugation tape was evaluated as x.

[Evaluation item 2]
The sheath of the produced optical fiber cable is peeled off as a whole, and the part where the optical fiber core wire ligation tape spirally wound around the optical fiber core wire is broken or thinned (including the thinned part). It was visually evaluated whether or not there was any (presence or absence of breakage or thinning).
Then, the case where the part was not broken and there was no thinned part was evaluated as ◯, the case where the part was not broken but was thinned was evaluated as Δ, the case where there was a broken part was evaluated as ×, and the cases other than ○ were rejected.

[Evaluation item 3]
Whether or not the optical fiber core wire conjugation tape melted between the optical fiber core wires and soiled the optical fiber core wires was visually evaluated by disassembling the optical fiber bundle (dirt of the optical fiber core wires).
Then, the case where the optical fiber core wire was not dirty was marked with ◯, and the case where the optical fiber core wire was dirty was marked with x.

[Evaluation item 4]
Remove the optical fiber core wire conjugation tape from the optical fiber core wire, slice the cross section perpendicular to the longitudinal direction of the optical fiber core wire conjugation tape into thin slices, magnify and photograph, and the island component resin becomes the sea component resin. It was evaluated whether or not it melted and integrated (tape soundness).
Then, the case where the island component resin was not dissolved in the sea component resin was marked with ◯, and the case where it was integrated was marked with x.

[Evaluation item 5]
The tensile elastic modulus and the elongation at break of the optical fiber core wire conjugation tape were measured by the following methods. The measurement was performed by pulling the optical fiber core wire conjugation tape with a tensile tester (manufactured by Shimadzu Corporation) at a width of 500 mm and a tensile speed of 500 mm / min until it broke.
The tensile elastic modulus was rated as ⊚ if it was 6300 to 8000 MPa, ◯ if it was 4000 to 10000 MPa (passed above), and x if it was outside the range of 4000 to 10000 MPa. If the elongation at break was 60% or less, it was evaluated as ◯, and if it exceeded 60%, it was evaluated as x.

The resins and the like used in Examples and Comparative Examples are as follows.
<Sea component resin>
(1) Low melting point polyester copolymer (polyester copolymer, manufactured by Unitika Ltd., melting point 160 ° C)
(2) Homo polypropylene (homo PP): Sumitomo Noblen D101 (trade name, manufactured by Sumitomo Chemical Co., Ltd., 163 ° C)
(3) Nylon (nylon (I)): Polyamide 6 1020 (trade name, manufactured by Ube Industries, Ltd., melting point 230 ° C)
(4) Random polypropylene (random PP): Wintech WSX02 (trade name, manufactured by Nippon Polypropylene, melting point 125 ° C)
(5) High-density polyethylene (HDPE): Nipolon Hard 6300 (trade name, manufactured by Tosoh Corporation, melting point 134 ° C)

<Island component resin>
(6) Polyethylene terephthalate (PET, manufactured by Unitika Ltd., melting point 250 ° C)
(7) Nylon (nylon (II)): Amylan CM1007 (trade name, manufactured by Toray Industries, Inc., melting point 225 ° C)
(8) Homopolypropylene (HomoPP): Sumitomo Noblen D101 (trade name, manufactured by Sumitomo Chemical Co., Ltd., 163 ° C)

<Sheath>
(9) Linear polyethylene (LLDPE): NUCG-7641 (trade name, manufactured by NUC, melting point 120 ° C.)
(10) Polyamide 6/66/12 copolymer (PA copolymer): UBESTA6434 (trade name, manufactured by Ube Industries, Ltd., melting point 188 ° C.)
(11) Nylon (Nylon (I)): Polyamide 6 1020 (trade name, manufactured by Ube Industries, Ltd.,
Melting point 230 ° C)
In Examples 1 and 2, three Unitika melsets 560detx / 48f were used.

In Examples 1 to 5, the melting point of the sea component resin of the optical fiber core wire conjugation tape, the melting point of the island component resin, and the difference between the melting point of the island component resin and the melting point of the sea component resin are described in claim 1 of the present invention. This is the case when the value is changed within the range, and the evaluation results are shown in Table I.
The evaluation results of each evaluation item are acceptable (○ or ◎), and the optical fiber core wire ligation tape 1 does not break or melt more than necessary even at a high die temperature during the manufacture of the optical fiber cable. It has become an excellent one. In addition, all of them are excellent in terminal workability required for optical fiber cables.

In Comparative Examples 1 to 3, the difference between the melting point of the sea component resin of the optical fiber core wire conjugation tape, the melting point of the island component resin, and the melting point of the island component resin and the melting point of the sea component resin is described in claim 1 of the present invention. If it is out of the range and the melting point of the sea component resin of the optical fiber core wire ligation tape is too low as in Comparative Examples 1 and 2, the terminal processability is not good at a high die temperature, and the optical fiber core wire conjugation In some cases, the tape was broken or thinned, or melted and the optical fiber core wire became dirty.
Further, as in Comparative Example 3, if the difference between the melting point of the island component resin and the melting point of the sea component resin is too small (0 ° C in the case of Comparative Example 3), the island component resin melts into the sea component resin and becomes integrated. Therefore, the original structure of the optical fiber core wire conjugation tape in which the fibrous island component resin is arranged in the sea component resin is not maintained.

Needless to say, the present invention is not limited to the above-described embodiment and can be changed as appropriate as long as it does not deviate from the gist of the present invention.

1 Optical fiber core wire conjugation tape 2 Sea component resin 3 Island component resin 10 Optical fiber cable 11 Optical fiber core wire 12 Optical fiber bundle 13 sheath

Claims (5)

It is formed of a tape-shaped sea component resin made of a thermoplastic resin and a fibrous island component resin made of a thermoplastic resin dispersed in the sea component resin in parallel.
The melting point of the sea component resin is larger than 150 ° C. and 230 ° C. or lower.
An optical fiber core wire conjugation tape characterized in that the melting point of the island component resin is 200 ° C. or higher and 260 ° C. or lower, and the melting point of the sea component resin is 20 ° C. or higher. The optical fiber core wire ligation tape according to claim 1, wherein the tensile elastic modulus is 4000 to 10000 [MPa]. The optical fiber core wire conjugation tape according to claim 1 or 2, wherein the sea component resin is a polyester copolymer, and the island component resin is polyethylene terephthalate. The optical fiber core wire conjugation tape according to any one of claims 1 to 3, wherein the island component resin has a diameter of 10 to 60 [μm]. A bundle of optical fibers formed by directly winding the optical fiber core wire ligation tape according to any one of claims 1 to 4 around a predetermined number of optical fiber cores is covered with a sheath. An optical fiber cable characterized by being

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