JPH09113773A - Coated optical fiber ribbon - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the mechanical strength characteristic as a coated optical fiber ribbon by substantially eliminating the influence of side pressures in unwinding, bending and pulling. SOLUTION: This coated optical fiber ribbon is constituted by supplying plural pieces of optical fibers 13 in the state of arranging these fibers side by side in parallel, coating the fibers with a UV curing type resin as a first coating layer 14 and coating this first coating layer 14 with the UV curing type resin as second coating layers 15. Two kinds of the UV curing type resins varying in Young's modulus and viscosity are used for the resin for coating the fibers as the second coating layers 15 and the resin for coating the fibers as the first coating 14. The UV curing type resin of the lower Young's modulus and viscosity of two kinds of the UV curing type resins is used for the first coating layer 14 and the plural optical fibers 13 are arranged side by side in parallel and are coated in this sate with this UV curing type resin uniformly over the entire part so as to meet to appearance and shape. The UV curing type resin having the higher Young's modulus and viscosity of two kinds of the UV curing type resins is used for the second coating layers 15 and the coated optical fiber ribbon is constituted by coating the first coating layer 14 described above with this UV curing type resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber ribbon, and more particularly to an GI type optical fiber ribbon having excellent mechanical properties.

[0002]

2. Description of the Related Art An optical fiber has a remarkable difference in physical or mechanical characteristics from a conventional copper conductor. Therefore, in an optical fiber drawing device, a primary coating and a secondary coating are drawn after spinning from an electric furnace. It has been applied to improve the mechanical properties and handleability of the optical fiber strand. In this state, the surface of this optical fiber strand is easily scratched and its mechanical strength is weak.Therefore, a single-core optical fiber core made of resin coating or multiple optical fiber strands arranged in parallel. To form a multi-fiber optical fiber ribbon which is lined up with and coated with a resin to form a tape.

Conventionally, when manufacturing an optical fiber ribbon, as shown in FIG. 4, an ultraviolet ray curable type buffer layer 2 and an ultraviolet ray curable type protective layer 3 are provided on the surface of a glass fiber 1.
And a UV-curable colored layer 4 for recognition on the UV-curable protective layer 3 and two optical fiber strands 5 having a predetermined outer diameter (usually about 250 μm), Four
Four or eight (four in FIG. 4) are arranged in parallel and covered collectively with the coating resin 6 to obtain the optical fiber ribbon 7.
An ultraviolet-curable acrylate resin is used as the coating resin 6, and after the ultraviolet-curable acrylate resin is coated, UV irradiation is performed with a UV lamp or the like to cure the optical fiber tape core wire 7.

The optical fiber tape core wire 7 thus obtained is used to secure mechanical strength in cable production, laying and use such as rewinding load, bending and tensile strength.
A so-called hard resin having a large Young's modulus, viscosity, etc. is generally used for the ultraviolet acrylate resin as the coating resin 6.

Further, as shown in FIG. 5 of Japanese Patent Laid-Open No. 1-155306, the surface of a glass fiber 1 is covered with two layers of an ultraviolet-curable buffer layer 2 and an ultraviolet-curable protective layer 3. 2, 4 or 8 (4 in FIG. 5) optical fiber strands 8 arranged in parallel are arranged in parallel, and the inner layer 9 and the Young's layer 9 of the ultraviolet curable resin having a Young's modulus at -40 ° C. of 10 kg / mm ² or more. The optical fiber tape core wire 1 is obtained by collectively coating the outer layer 10 of the ultraviolet curable resin having a rate of 40 to 100 kg / mm ^2.
1 is configured.

[0006]

However, in the case of the former case, a plurality of GI type optical fibers having a larger core diameter than the SM type fiber and in which transmission loss is likely to increase due to the influence of microbend due to lateral pressure are arranged in parallel. In the case of covering them side by side, or considering that the SM type optical fiber is used at a wavelength of 1.55 μm in an ordinary 1.31 μm wavelength specification fiber, the Young's modulus as a coating resin for the optical fiber tape core wire 7, Large viscosity,
If the so-called hard resin is used for collective coating, the hard resin and the optical fiber element wire 5 come into direct contact with each other, and are easily affected by lateral pressure generated during rewinding, bending, pulling, or the like.

In the latter case, the soft inner layer 9 and the hard outer layer 10 are covered by a two-layer coating so that the outer layer 10 and the outer layer 10 have the same outer shape. The inner layer 9 and the outer layer 10 forming the wire 11 are not evenly applied to the optical fiber wire 8 when the resin is hardened by irradiation with a hardening UV lamp, and are easily affected by lateral pressure.

An object of the present invention is to apply a force generated when a resin is cured by irradiation of a curing UV lamp to a coating layer constituting an optical fiber ribbon, and to apply the force to the optical fiber strand substantially evenly. The purpose is to make it less susceptible to lateral pressure during bending, pulling, etc. and to improve the mechanical strength resistance characteristics of the optical fiber ribbon.

[0009]

In order to achieve the above object, in the optical fiber ribbon according to the first aspect of the present invention, a plurality of optical fiber element wires are supplied in parallel and UV is supplied. In the optical fiber tape core wire, which is obtained by coating a curable resin as a first coating layer, and coating a UV curable resin as a second coating layer on the first coating layer, a resin coated as the first coating layer. And two kinds of UV-curable resins having different Young's moduli and viscosities are used as the resin to be coated as the second coating layer, and the first coating layer has two types of UV-curable resins having different Young's modulus and viscosity. A low UV curable resin is used to uniformly coat the entire plurality of optical fiber strands in parallel according to the external shape of the aligned state.
The coating layer is formed by coating the first coating layer with a UV-curing resin having a high Young's modulus and a high viscosity among two types of UV-curing resins. In this way, a plurality of optical fiber strands are arranged in parallel, the periphery is softened, and the surface portion of the optical fiber tape core wire is hardened to obtain a transmission loss characteristic against a microbend or the like in the GI type optical fiber tape core wire, Both the mechanical strength resistance characteristics of the fiber tape core wire can be improved. Further, the presence of the first coating layer (relaxation layer) having a uniform thickness prevents the lateral pressure from being relaxed on the optical fiber strand at low temperature and prevents the array disorder of the optical fiber strand in the optical fiber ribbon during manufacturing. You can

In order to achieve the above object, claim 2 of the present application
In the optical fiber ribbon according to the invention described above, the resin coated as the first coating layer and the resin coated as the second coating layer are used as the second coating layer after the resin coated as the first coating layer is UV-cured. It is carried out by a two-step coating in which a resin to be coated is coated. Therefore, in order to coat the second coating layer after the first coating layer is UV-cured, a uniform pressure can be applied to the optical fiber strand when the second coating layer is coated and UV-cured, The second coating layer can prevent uneven lateral pressure from being applied.

In order to achieve the above object, claim 3 of the present application
In the optical fiber ribbon according to the invention described above, the second coating layer is uniformly coated over the entire surface in accordance with the external shape of the first coating layer. Therefore, in order to coat the second coating layer in a shape similar to that of the first coating layer, the pressure generated when the second coating layer is UV-cured is uniformly applied to the optical fiber element wire, and an unreasonable lateral pressure is applied. It is possible to prevent adding.

[0012] In order to achieve the above-mentioned object, claim 4 of the present application
In the optical fiber ribbon according to the invention, the resin coated as the first coating layer has a viscosity of 25 at 25 ° C.
1500 to 30 at 35 ° C at 00 to 5000 cps
It is composed of a UV-curable acrylate resin of 00 cps. Therefore, the hardness of the resin coated as the first coating layer is low, the pressure generated when the second coating layer is UV-cured is absorbed, and the lateral pressure can be prevented from being directly applied to the optical fiber element wire.

In order to achieve the above-mentioned object, claim 5 of the present application
In the optical fiber ribbon according to the invention described above, the resin coated as the second coating layer has a viscosity of 50 at 25 ° C.
2000-40 at 35 ° C at 00-9000cps
It is composed of a UV-curable acrylate resin of 00 cps. Therefore, the hardness of the resin coated as the second coating layer is high, and the mechanical strength resistance characteristic of the optical fiber ribbon can be improved.

In order to achieve the above object, claim 6 of the present application
In the optical fiber ribbon according to the invention described above, the resin coated as the first coating layer has a Young's modulus of 1.0 at 60 ° C.
Kg / mm ² or less, which is constituted by 10.0 kg / mm ² or less of ultraviolet curable acrylate resin at -40 ° C..
Therefore, the hardness of the resin coated as the first coating layer is low, the pressure generated when the second coating layer is UV-cured is absorbed, and the lateral pressure can be prevented from being directly applied to the optical fiber element wire.

In order to achieve the above object, claim 7 of the present application
In the optical fiber ribbon according to the invention described above, the resin coated as the second coating layer has a Young's modulus of 50K at 60 ° C.
It is composed of an ultraviolet ray-curable acrylate resin of g / mm ² or less and 250 Kg / mm ² or less at −40 ° C. Therefore, the hardness of the resin coated as the second coating layer is high,
The mechanical strength resistance property of the optical fiber ribbon can be improved.

In order to achieve the above object, the present invention
In the optical fiber ribbon according to the invention described above, the resin coated as the first coating layer is composed of an ultraviolet curable acrylate resin having a curing shrinkage of 3% or less. Therefore, the hardness of the resin coated as the first coating layer is low, the pressure generated when the second coating layer is UV-cured is absorbed, and the lateral pressure can be prevented from being directly applied to the optical fiber element wire.

In order to achieve the above object, claim 9 of the present application
In the optical fiber ribbon according to the invention described above, the resin coated as the second coating layer is composed of an ultraviolet-curable acrylate resin having a curing shrinkage of 3 to 6%. Therefore, the hardness of the resin coated as the second coating layer is high, and the mechanical strength resistance characteristic of the optical fiber ribbon can be improved.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below. FIG. 1 shows one embodiment of an optical fiber ribbon according to the present invention.

In the figure, reference numeral 12 is an optical fiber tape core wire, in which four optical fiber element wires 13 are arranged in parallel and four optical fiber element wires 13 are entirely covered with a first coating layer 14,
The first coating layer 14 is covered with a second coating layer 15 to form a structure. This optical fiber strand 13 is, specifically,
It is a GI type optical fiber.

The optical fiber strand 13 is the glass fiber 1
UV curable buffer layer 2 and UV curable protective layer 3 on the surface of
And is molded into a predetermined outer diameter (usually about 250 μm). The optical fiber strand 13 may be formed by coating the ultraviolet-curable protective layer 3 with an ultraviolet-curable colored layer 4 for identification, if necessary. The first coating layer 14 and the second coating layer 15 are coating layers that coat the entire four optical fiber strands 13, and two types of UV curable resins having different Young's modulus, viscosity, and curing shrinkage ratio are used. Has been. Of the two types of UV-curable resins, the first coating layer 14 is a UV-curable resin having a low Young's modulus, viscosity, and curing shrinkage ratio, and the second coating layer 15 is one of the two types of UV-curable resins. UV curable resins having high Young's modulus, viscosity, and curing shrinkage are used, respectively. That is, "soft resin" is used as the buffer layer for the first coating layer 14 as the inner layer, and "hard resin" is used as the protective layer for improving the mechanical strength as the second coating layer 15 as the outer layer. . This first
UV-curable acrylate resins are used for the coating layer 14 and the second coating layer 15, and the viscosity, Young's modulus, and curing shrinkage of these UV-curable acrylate resins are specified within the ranges shown in Table 1. It seems that.

Table 1 That is, the viscosity of the ultraviolet curable acrylate resin that is the first coating layer 14 is 2500 to 5000 cps at 25 ° C.
And 1500 to 3000 cps at 35 ° C. Also,
Young's modulus of the UV-curable acrylate resin is first coating layer 14, at 60 ℃ 1.0Kg / mm ² or less, 23 ° C. at 1.0 Kg / mm ² or less, 1.0 Kg / mm ² or less at -40 ℃ Is. Further, the curing shrinkage rate of the ultraviolet curable acrylate resin that is the first coating layer 14 is 3% or less.

Further, the viscosity of the UV-curable acrylate resin as the second coating layer 15 is 5000 to 90 at 25 ° C.
00 cps, 2000-4000 cps at 35 ° C. The Young's modulus of the ultraviolet curable acrylate resin which is the second coating layer 15 is 50 Kg / mm ² or less at 60 ° C.,
100 kg / mm ² or less at 23 ° C, 250 kg at -40 ° C
/ Mm ² or less. In addition, the curing shrinkage rate of the ultraviolet curable acrylate resin that is the second coating layer 15 is 3% to 6% or less.

The first coating layer 14 and the second coating layer 15 are formed by coating the coating resin on which four optical fiber strands 13 are arranged in parallel.
In the case of using the above two kinds of coating resins, the relationship between the two coating layers may be any one of the viscosity, the Young's modulus and the curing shrinkage as shown in Table 1. That is,
The first coating layer 14 has a viscosity of 2500 to 50 at 25 ° C.
The ultraviolet ray-curable acrylate resin having the characteristics of 00 cps and 1500 to 3000 cps at 35 ° C. is used.
A desired effect can be obtained by using an ultraviolet-curable acrylate resin having a characteristic of 2000 to 4000 cps at 35 pC and 35 ° C. In addition, the first coating layer 14
And its Young's modulus at 60 ° C is 1.0 Kg / mm ² or less, 2
1.0 Kg / mm ² or less at 3 ° C, 1.0 Kg / mm at -40 ° C
The second coating layer 15 has a Young's modulus of 5 at 60 ° C. by using an ultraviolet-curable acrylate resin having a characteristic of not more than mm ^2.
0 kg / mm ² or less, 100 Kg / mm ² or less at 23 ° C., -
A desired effect can be obtained by using an ultraviolet-curable acrylate resin having a characteristic of 250 Kg / mm ² or less at 40 ° C. Further, the first coating layer 14 is made of an ultraviolet curable acrylate resin having a curing shrinkage of 3% or less, and the second coating layer 15 is made of an ultraviolet ray having a curing shrinkage of 3 to 6%. A desired effect can be obtained by using the curable acrylate resin.
Furthermore, when the relationship between the first coating layer 14 and the second coating layer 15 satisfies any two characteristics among viscosity, Young's modulus and curing shrinkage, three characteristics of viscosity, Young's modulus and curing shrinkage are obtained. Needless to say, the case may be satisfied.

The first coating layer 14 is made uniform (so-called spectacles shape) as a whole in accordance with the external shape of a state in which four optical fiber strands 13 are arranged in parallel with each other and a plurality of ultraviolet ray-curable acrylate resins are aligned. It is configured by coating. That is, unlike the cross-sectional shape of the second coating layer 15, the first coating layer 14 has a cross-sectional shape in which the coating layer thickness is relatively uniform and the pressure and the like are evenly dispersed / buffered for each optical fiber element wire 13. ing. The second coating layer 15 is formed by extruding and coating an ultraviolet-curable acrylate resin on the first coating layer 14.

Such an optical fiber tape core wire 12 is
It is manufactured based on the manufacturing line 16 as shown in FIG.
That is, four optical fiber strands 13 wound around separate optical fiber strand bobbins 17 are collected,
Immediately after applying the first coating layer resin (ultraviolet curable acrylate resin) with the first coating die 18 to obtain the cross-sectional shape of the first coating layer 14 by arranging four in parallel, the first curing UV lamp 1
The first coating layer resin is cured at 9, and then the second coating die 2
The second coating resin (ultraviolet curable acrylate resin) is applied at 0, and immediately after that, the second coating resin is cured by the second UV lamp 21 to obtain a predetermined size and is wound by the winding bobbin 22. This coating method is usually performed in a vertical line,
It is also possible to carry out on horizontal lines.

FIG. 3 shows another embodiment of the optical fiber ribbon according to the present invention.

In the figure, reference numeral 23 is an optical fiber tape core wire, in which four optical fiber element wires 13 are arranged in parallel and the four optical fiber element wires 13 are entirely covered with a first coating layer 14.
The first coating layer 14 is covered with a second coating layer 24. This optical fiber strand 23 is, specifically,
It is a GI type optical fiber.

The present embodiment differs from the embodiment shown in FIG. 1 in that the embodiment shown in FIG. 1 has an external shape in which four optical fiber strands 13 are arranged in parallel. According to the above, the first coating layer 14 is coated with a substantially uniform thickness, and the second coating layer 15 is coated on the first coating layer 14 in a vertically flat manner. The external shape of the first coating layer 14 in which the four optical fiber strands 13 are arranged side by side in parallel and the thickness of the first coating layer 14 is substantially uniform (so-called eyeglass type) (the optical fiber strands 13 are arranged in parallel). This is the point that the second coating layer 15 is coated in conformity with the four external appearances that are aligned. Others are the same as the embodiment shown in FIG.

[0029]

According to the present invention, by using two kinds of UV-curable acrylate resins having different Young's moduli and viscosities to soften the periphery of the optical fiber strand and harden the surface of the optical fiber tape, the GI type optical fiber is particularly effective. It is possible to improve both the transmission loss characteristics of the fiber tape core wire against micro bends and the like and the mechanical strength resistance characteristics of the optical fiber tape core wire. Further, compared with the conventional collective coating method, the lateral pressure is relaxed to the optical fiber element wire at a low temperature due to the presence of the first coating layer (relaxation layer) of uniform thickness, and the optical fiber element in the optical fiber tape core wire at the time of manufacturing. It is also effective in preventing line arrangement disorder.

[Brief description of the drawings]

FIG. 1 is an end view showing an embodiment of an optical fiber ribbon according to the present invention.

FIG. 2 is a schematic view of a manufacturing line for manufacturing the optical fiber ribbon shown in FIG.

FIG. 3 is an end view showing another embodiment of the optical fiber ribbon according to the present invention.

FIG. 4 is an end view of a conventional optical fiber ribbon.

FIG. 5 is an end view of another conventional optical fiber tape core wire.

[Explanation of symbols]

 1 ………………………………………… Glass fiber 2 …………………………………… UV curing buffer layer 3 …………………………………… UV rays Curing type protective layer 4 ………………………………………… UV curing type coloring layer 12 …………………………………… Optical fiber tape core wire 13 …………………… ………… Optical fiber element 14 …………………………………… 1st coating layer 15 ……………………………… 2nd coating layer 16 …………………… …………… Production line 17 …………………………………… Optical fiber strand bobbin 18 ……………………………… First coating die 19 …………………… …………… First curing UV lamp 20 …………………………………… Second coating die 21 ……………………………… Second UV lamp 22 ……………… ……………… Winding bobbin 23 ……………… .................. optical fiber ribbon 24 .................................... second covering layer

Claims (9)

[Claims] 1. A plurality of optical fiber strands are arranged in parallel and supplied, a UV-curable resin is coated as a first coating layer, and a second UV-curable resin is coated on the first coating layer. In an optical fiber ribbon coated with a layer, a resin coated as the first coating layer and a resin coated as the second coating layer have two types of U having different Young's moduli and viscosities.
V-curable resin is used, and the first coating layer has two types of U
The UV-curing resin having a low Young's modulus and a low viscosity of the V-curing resin is used to uniformly coat the plurality of optical fiber strands in parallel with each other according to the external shape of the aligned optical fibers. The optical fiber tape core wire is characterized in that the layer is formed by coating the first coating layer with a UV curable resin having a high Young's modulus and a high viscosity among two types of UV curable resins. . 2. The resin coated as the first coating layer and the resin coated as the second coating layer are the resin coated as the second coating layer after the resin coating as the first coating layer is UV cured. The optical fiber tape core wire according to claim 1, which is performed by a two-step coating for coating. 3. The optical fiber tape core wire according to claim 1, wherein the second coating layer is uniformly coated over the entire surface in accordance with the outer shape of the first coating layer. 4. The resin coated as the first coating layer comprises:
Viscosity is 35 at 2,500 to 5,000 cps at 25 ° C
The optical fiber ribbon according to claim 1, which is an ultraviolet-curable acrylate resin having a temperature of 1500 to 3000 cps at a temperature of ℃. 5. The resin coated as the second coating layer is
Viscosity 35 at 5,000-9000 cps at 25 ° C
The optical fiber ribbon according to claim 1, which is an ultraviolet-curable acrylate resin having a temperature of 2000 to 4000 cps at a temperature of ℃. 6. The resin coated as the first coating layer comprises:
Young's modulus of 1.0 Kg / mm ² or less at 60 ° C., the optical fiber according to claim 2, 3, 4, 5 or 6, wherein the 10.0 kg / mm ² or less of ultraviolet curable acrylate resin at -40 ℃ Tape core wire. 7. The resin coated as the second coating layer comprises:
Young's modulus is less than 50 kg / mm ² at 60 ° C, 2 at -40 ° C
The optical fiber ribbon according to claim 1, which is an ultraviolet-curable acrylate resin having a weight of 50 kg / mm ² or less. 8. The resin coated as the first coating layer comprises:
The optical fiber tape core wire according to claim 1, which is an ultraviolet curable acrylate resin having a curing shrinkage of 3% or less. 9. The resin coated as the second coating layer comprises:
An optical fiber ribbon according to claim 1, 2, 3, 4, 5, 6, 7 or 8, which is an ultraviolet curable acrylate resin having a curing shrinkage of 3 to 6%.