JPH10115737A - Single core coated optical fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make it possible to make connection work easier and more efficient by incorporating a specific weight or above of a reactive silicone compd. into a UV curing type resin of the outermost layer protective film. SOLUTION: The single core coated optical fiber 10 consists of an optical fiber 12 and the outermost layer protective film 14. The optical fiber 12 comprises an optical fiber 16, a coating layer 18 clad on the optical fiber 16 and a colored layer 20 clad on the coating layer 18. The optical fiber 16 consists of a core 22 and a clad 24 existing on the outer periphery of the core 22. The coating layer 18 consists of a primary coating layer 18A clad on the optical fiber 16 and a secondary coating layer 18B clad on the primary coating layer 18A. The outermost layer protective film 14 is formed of a UV curing type resin, such as urethane acrylate. The UV curing type resin of the outermost layer protective film 14 contains >=1wt.% reactive silicone and, therefore, the outermost layer protective film 14 may be provided with a release property.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in a single optical fiber formed by coating an optical fiber with an ultraviolet curable resin or the like.

[0002]

2. Description of the Related Art In general, a single optical fiber used for optical communication or the like generally includes a core 22 and a cladding 2 as shown in FIG.
4 and a coating layer 18 coated on the optical fiber 16. In the illustrated optical fiber single fiber 10, the coating layer 18 is formed on the optical fiber 16 by a primary coating layer 18A made of a thermosetting resin such as silicon, and on the primary coating layer 18A. And a secondary coating layer 18B made of a thermoplastic resin such as nylon.

The single optical fiber 10 is connected to, for example, each optical fiber 2 of an optical fiber ribbon 1 laid outdoors as shown in FIG. 5 to drop an optical communication network into a house. Sometimes used as a cable.
Each optical fiber strand 2 of the optical fiber ribbon 1 shown in FIG. 5 usually has an outer diameter d _{t of} 250 μm (see FIG. 5). However, on the other hand, the general optical fiber single core fiber 10 shown in FIG. 4 is usually provided with a coating layer 18 in consideration of handleability in indoor wiring, protection from various external environments, and the like. The outer diameter d ₁ (see FIG. 4) is about 0.9 mm, which is larger than this 250 μm, and coincides with the outer diameter _dt of each optical fiber 2 of the optical fiber ribbon 1. Did not.

For this reason, for example, when four optical fiber single wires 10 shown in FIG. 4 are connected to four optical fiber tape wires 1 shown in FIG.
Are arranged closely in parallel, the optical fiber 16 of these four optical fiber single wires 10 and the optical fiber tape
5 cannot be collectively connected because the positions of the optical fibers and the optical fibers do not match. Conventionally, it was necessary to separate and connect the optical fiber ribbons 1 shown in FIG.
Therefore, a total of four connections were required, and the work efficiency of the connection was poor.

In order to solve this problem, as shown in FIG. 1, an optical fiber 16 and a coating layer 18 (a primary coating layer 18A and a secondary coating layer 18B) coated on the optical fiber 16 are provided. And a colored layer 20 coated as required on the coating layer 18. The outer diameter d ₂ (see FIG. 1) is 250 μm.
Outermost protective coating 14 made of UV-curable resin or the like
To form the optical fiber single fiber 10.

In such an optical fiber single fiber 10, the outermost protective coating 14 provides the optical fiber 1
2. While ensuring easy handling and protection from the external environment,
At the time of connection, as shown in FIG. 2, the optical fiber strand 12 having an outer diameter d ₂ of 250 μm is exposed simply by stripping the outermost protective coating 14. In this case, the outer diameter d ₂ of the exposed optical fiber 12 matches the outer diameter _dt of each optical fiber 2 of the optical fiber ribbon 1 shown in FIG. The optical fiber 12 of the four optical fibers 10 without separating the
Can be connected to the four optical fiber strands 2 of the optical fiber ribbon 1 by simply arranging them in parallel and closely. In other words, only one connection work is required, so that the connection work efficiency is improved.

[0007]

However, if the adhesion between the outermost protective coating 14 and the colored layer 20 is too strong, the outermost protective coating 14 takes time to peel off, and in some cases, the outermost protective coating 14 may be peeled off. The ultraviolet curable resin or the like forming the coating 14 partially remains on the surface of the coloring layer 20, or the coloring layer 20 or the coating layer 18 together with the outermost protective coating 14.
Of the outermost protective coating 14
May not be properly peeled off from the colored layer 20.

In this case, the coloring layer 20 itself is made to have releasability by adjusting the components and the like of the coloring layer 20 which is in close contact with the outermost protective coating 14 to reduce the adhesion of the coloring layer 20.
The outermost protective coating 14 is coated with the colored layer 20 of the optical fiber 12.
It is conceivable that the film is easily peeled off. However, if the colored layer 14 itself has such easy releasability, not only the adhesion of the colored layer 20 to the outermost protective coating 14 but also the adhesion of the colored layer 20 to the inner coating layer 18 is reduced. At the time of or after the peeling operation of the outermost protective coating 14, even the colored layer 20 may be peeled from the coating layer 18. If the coloring layer 20 is also peeled off from the coating layer 18 in this manner, the identification function of the coloring layer 20 is impaired, and it becomes necessary to apply the coloring layer 20 again, and the connection work is rather troublesome. There is.

The same problem may occur in the coating layer 18 even when the colored layer 20 is not provided.
That is, in this case, if the coating layer 18 (the secondary coating layer 18B in the case of the two-layer coating layer 18B as shown in FIG. 1) itself having a releasability is provided, the coating layer 18 adheres to the outermost protective coating 14. The coating layer 18 (or the secondary coating layer 18B) is peeled off from the optical fiber 16 (or the primary coating layer 18A), and it becomes necessary to coat the coating layer 18 or the secondary coating layer 18B again. There is a risk that the work will be rather troublesome.

An object of the present invention is to solve the above-mentioned problems by providing the outermost protective coating with releasability so that only the outermost protective coating can be almost certainly easily and appropriately peeled off. An object of the present invention is to provide an optical fiber single-core wire that can perform work easily and efficiently.

[0011]

According to the present invention, there is provided an optical fiber comprising a core and a clad, and an optical fiber comprising a coating layer coated on the optical fiber. An optical fiber single core wire comprising a fiber strand and an outermost protective coating made of an ultraviolet curable resin coated on the optical fiber strand, wherein the ultraviolet curable resin of the outermost protective coating is 1 An object of the present invention is to provide an optical fiber single core wire characterized by containing a reactive silicone compound in an amount of at least% by weight. In this case, the optical fiber may further include a coloring layer provided on the coating layer.

As described above, when the UV-curable resin of the outermost protective coating contains 1% by weight or more of the reactive silicone compound, the outermost protective coating can have releasability. The adhesion of the protective coating to the coating layer or the colored layer is reduced, and as can be seen from the embodiments of the present invention described later, the outermost protective coating alone is almost certainly easily and appropriately peeled off with a simple jig to be connected. Work can be performed easily and efficiently.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a single optical fiber 10 of the present invention. The optical fiber comprises an optical fiber 12 and an outermost protective coating 14 further coated on the optical fiber 12.

As shown in FIG. 1, the optical fiber 12 is composed of an optical fiber 16, a coating layer 18 coated on the optical fiber 16, and a colored layer coated on the coating layer 18. 20.

As is well known, the optical fiber 16 comprises a core 22 and a clad 24 located on the outer periphery of the core 22, as shown in FIG. 1, and is used for optical communication in the illustrated embodiment. It has a typical outer diameter of 125 μm. In addition, as the optical fiber 16, a quartz-based fiber mainly used for optical communication can be used.
The present invention is not necessarily limited to this, and for example, other glass-based fibers such as halide glass-based or multi-component glass-based, or plastic-based fibers can also be used.

The coating layer 18 can be formed of, for example, an ultraviolet curable resin such as urethane acrylate.
In this case, the coating layer 18 converts the optical fiber 16 into, for example,
The optical fiber 16 is coated with an ultraviolet-curable resin through a resin extruder, and then the optical fiber 16 on which the ultraviolet-curable resin is applied is passed through an ultraviolet irradiator to remove the ultraviolet-curable resin. It can be formed by curing. However, the coating layer 18 is not necessarily limited to the UV-curable resin, and the coating layer 18 may be formed of another thermosetting resin such as silicon or a thermoplastic resin such as nylon.

In the illustrated embodiment, the coating layer 18 has a primary coating layer 18A coated on the optical fiber 16 and a primary coating layer 18A on the optical fiber 16, as shown in FIG. And a coated secondary coating layer 18B. These primary and secondary coating layers 18A and 18B can be formed on the optical fiber 16 by tandem extrusion coating. The primary coating layer 18A and the secondary coating layer 18
B may be formed from different materials or may be formed from the same material. Further, unlike the illustrated embodiment, the coating layer 18 may be formed as a single layer.

The coloring layer 20 can be formed, for example, by coating a UV-curable resin containing a pigment on the coating layer 18 in a thin coating, as shown in FIG. The colored layer 20 is mainly coated for identifying the optical fiber 12 at the time of connection, and is preferably provided as much as possible from the viewpoint of improving the efficiency of the connection work.
It is sufficient if provided as needed, and it is not always necessary to provide it.

The outer diameter d of the optical fiber 12 is as follows.
₂ (see FIG. 1) is the optical fiber ribbon 1 shown in FIG.
It is desirable to set the outer diameter _dt of the optical fiber 2 to 250 μm, which is the same as the outer diameter _dt . Thus, at the time of connection, the optical fiber 12 can be directly connected to the optical fiber 2 of the optical fiber ribbon 1 without adjusting the outer diameter d ₂ of the optical fiber 12.

As shown in FIG. 2, the outermost protective coating 14 is used to connect the single optical fiber 10 of the present invention to the single optical fiber ribbon 1 shown in FIG.
Is peeled off from the colored layer 20 of the optical fiber 12 at the connection end of the optical fiber. On the other hand, the outermost protective coating 14 has an outer diameter d of a certain size on the optical fiber single core wire 10 at a portion other than the connection end and before the connection work.
₁ (see FIG. 1), and the small-diameter optical fiber 12
To provide easy handling for indoor wiring,
The optical fiber 12 is sufficiently protected from the external environment.

The outermost protective coating 14 is formed of an ultraviolet-curable resin such as urethane acrylate, and is formed on the optical fiber 12 in the same manner as the coating layer 18 of the optical fiber 12 described above. It can be coated with an appropriate outer diameter and thickness such as 0.5 mm. In this case, in the present invention, the ultraviolet curable resin of the outermost protective coating 14 contains 1% by weight or more of the reactive silicone compound. Thereby, the outermost protective coating 14 can have releasability.

As described above, in the present invention, since the adhesion of the outermost protective coating 14 to the colored layer 20 is low, as will be understood from the embodiments of the present invention described later, the outermost protective coating 14 will be described.
Can be easily peeled off from the colored layer 20 with a simple jig such as a cutter or a nipper. At the same time, in this case, since only the outermost protective coating 14 has releasability, it is necessary to appropriately peel off only the outermost protective coating 14 from the optical fiber 12 without peeling off the coloring layer 20 from the coating layer 18. Can be. Therefore, the identification function of the colored layer 20 is not impaired, and there is no need to cover the colored layer 20 again, and the connection operation can be performed easily and efficiently.

Further, since the above-described optical fiber wire 12 having an outer diameter d ₂ of 250 μm is appropriately exposed by simply peeling off the outermost protective coating 14, the connection of the single optical fiber 10 The outer diameter at the end can be easily set to 250 μm without adjusting by cutting or the like, and therefore, the optical fiber ribbon 1 shown in FIG. By simply arranging the plurality of optical fiber wires 12 closely and in parallel, it is possible to collectively connect the optical fiber ribbons 1 to the optical fiber ribbon 1 in a single connection operation, and perform the connection operation easily and efficiently. be able to.

The outermost protective coating 14 is effective even when the colored layer 20 is not provided. Specifically, for example, unlike the embodiment shown in FIG. 1, the coating layer 18 is formed into a single layer, and the single-layer coating layer 18 is formed.
On the outermost protective coating 1 without providing the coloring layer 20
In the case where the optical fiber 1 is provided, the coating layer 18 is
6, only the outermost protective coating 14 can be simply and properly peeled off. The coating layer 18
1, the outermost protective coating 14 is provided on the secondary coating layer 18B without providing the coloring layer 20 on the secondary coating layer 18B, similarly to the embodiment of FIG.
Can be simply and appropriately peeled off without peeling off the primary coating layer 18A.

[0025]

EXAMPLES AND COMPARATIVE EXAMPLES Next, the process of obtaining the appropriate content of the reactive silicone compound in the ultraviolet-curable resin forming the outermost protective coating layer 14 described above will be described with reference to Examples of the present invention and various comparative examples. The effects of the present invention will be proved, as described below with reference to examples.

First, as Examples and Comparative Examples of the present invention,
A coating layer 18 composed of a primary coating 18A and a secondary coating 18B of urethane acrylate is coated on a silica glass optical fiber 16 having an outer diameter of 125 μm, and a urethane containing pigment is coated on the coating layer 18. An optical fiber wire 12 having an outer diameter d ₂ of 250 μm coated with the acrylate coloring layer 20 is manufactured, and an outermost protective coating 14 of urethane acrylate is coated on the optical fiber wire 12 to form an outer diameter d. The optical fiber single core wire 10 shown in FIG. 1 having d ₁ of 0.5 mm was manufactured.

In this case, the content of the reactive silicone compound in the urethane acrylate forming the outermost protective coating 14 was set to 1% by weight in the examples of the present invention, and in some comparative examples, These were set to 0% by weight (Comparative Example 1: one containing no reactive silicone compound), 0.5% by weight (Comparative Example 2), and 0.8% by weight (Comparative Example 3).

Next, as shown in FIG. 3, a peeling test of the outermost protective coating 14 was performed on the four single-core optical fibers 10 using a peeling test apparatus 30 as shown in FIG. Specifically, as shown in FIGS. 3B and 3C, a total of four single optical fibers 10 of the embodiment of the present invention and the comparative example are respectively connected to the upper and lower 3A and 3B.
As shown by the arrow (B), the single-core optical fiber 10 was pulled in one direction by 30 cm, and an attempt was made to peel off the outermost protective coating 14 over a length of 30 cm. Each of the upper and lower semicircular cutter portions 32A and 32B has an opening width t (see FIG. 3C) of 250 μm, which is the same as the outer diameter of the optical fiber 12.

[0029]

[Table 1]

Table 1 shows the results of the above peeling test. In the evaluation of the test results, the peel test was performed ten times for the examples of the present invention and each comparative example, and the number of successful peels in the ten peel tests was used as a reference. In this case, a part of the ultraviolet curable resin of the outermost protective coating 14 remains on the colored layer 20 of each optical fiber 12, or the uppermost and lower semicircular cutter portions A case in which the outer layer protective coating 14 cannot be peeled off by being caught on 32A or 32B, or a part of the colored layer 20 that has been peeled off together with the outermost protective coating 14 is regarded as a failure, and only the outermost protective coating 14 can be properly peeled off. Only succeeded.

Focusing on Table 1 based on the above evaluation method, in Comparative Example 1 containing no reactive silicone compound, the outermost protective coating 14 was properly peeled off even once in ten peel tests. I couldn't do that. From this, without containing any reactive silicone compound,
It has been found that it is difficult to even strip the outermost protective coating 14.

Next, focusing on Comparative Examples 2 and 3 in Table 1, although the success rate was low, it was possible to peel off the outermost protective coating 14 with a certain probability. From a comparison between the results of Comparative Examples 2 and 3 and the results of Comparative Example 1, it was found that the outermost protective coating 14 could have releasability if a reactive silicone compound was included. . However, on the other hand,
In Comparative Example 2 and Comparative Example 3, there were several failures. However, in this case, the outermost protective coating 14 could not be peeled off almost certainly, which might hinder the connection work. For this reason, it is necessary to further improve the peeling success probability.

Therefore, focusing on the embodiment of the present invention containing 1% by weight of the reactive silicone compound, only the outermost protective coating 14 was coated with the colored layer 2 in all 10 peeling tests.
It could be stripped from zero. From this, it was found that the UV-curable resin of the outermost protective coating 14 needed to contain at least 1% by weight of the reactive silicone compound, and at the same time, in the embodiment of the present invention, almost 100% by weight.
%, Easily and properly, the outermost protective coating 1
It can be seen that only 4 can be stripped.

[0034]

According to the present invention, as described above, the ultraviolet curable resin of the outermost protective coating contains 1% by weight or more of the reactive silicone compound. The outermost protective coating has low adhesion to the coating layer or coloring layer, and the outermost protective coating alone is almost certainly easily and properly peeled off with a simple jig, facilitating connection work. There are benefits that can be done efficiently.

[Brief description of the drawings]

FIG. 1 is an end view of an optical fiber single fiber of the present invention.

FIG. 2 is an end view when a single optical fiber of the present invention is connected.

FIG. 3 shows a peeling test apparatus for testing the peelability of the single optical fiber of Examples and Comparative Examples of the present invention, and FIG. 3A is a schematic perspective view showing a state before the single optical fiber is sandwiched. FIG. 1B is a schematic perspective view showing a state where an optical fiber single fiber is sandwiched, and FIG. 1C is an enlarged front view of a semicircular cutter portion of the peeling test apparatus.

FIG. 4 is an end view of a general single optical fiber.

FIG. 5 is an end view of an optical fiber ribbon connected to the optical fiber single core of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Optical fiber ribbon 2 Optical fiber strand of optical fiber tape 10 Optical fiber single core 12 Optical fiber single core of optical fiber 14 Outermost protective coating 16 Optical fiber 18 Coating layer 18A Primary coating layer 18B Secondary coating layer 20 Colored layer 22 Core 24 Cladding d ₁ Outer diameter of outermost protective coating (outer diameter of single optical fiber) d ₂ Outer diameter of optical fiber strand t Opening width of semicircular cutter d _t Outside diameter of optical fiber strand of optical fiber

Continuing from the front page (72) Inventor Yasuhiro Uekura 2-6-1 Marunouchi, Chiyoda-ku, Tokyo Inside Furukawa Electric Co., Ltd. (72) Inventor Kazuo Hokari 3-2-19-1 Nishishinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Telephone Co., Ltd. (72) Inventor Shinichi Furukawa Nippon Telegraph and Telephone Co., Ltd.

Claims (2)

[Claims] 1. An optical fiber comprising an optical fiber comprising a core and a clad and a coating layer coated on the optical fiber, and an ultraviolet curing type coated on the optical fiber. An optical fiber single core wire comprising a resin outermost protective coating, wherein the ultraviolet curable resin of the outermost protective coating contains 1% by weight or more of a reactive silicone compound. Single fiber fiber. 2. The single-core optical fiber according to claim 1, wherein the single-core optical fiber further includes a coloring layer provided on the covering layer. line.