JP2001322838A - Method for manufacturing tape like coated optical fiber - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress the tack phenomenon due to the tackiness of the integral coating surfaces of tape-like coated optical fibers and to improve transmission characteristics as well. SOLUTION: The integral coating is formed by lining up a plurality of optical fibers 2 formed by applying fiber coatings on glass fibers in parallel, applying an electron beam curing type resin by a coating applicator 7 thereon so as to cover these fibers and curing the resin by irradiating the resin with electron beams of different acceleration voltages regulated in one to, for example, >=30 60 kv and in the other to 60 250 kv by means of primary and secondary electron beam irradiation devices 9 and 11. The formation of the continuous integral coating is made possible by applying the electron beam curing type resin by a coating applicator 7' on a plurality of the ribbon-like coated optical fibers lined up in parallel and curing the resin by irradiating the resin with the electron beams of the different acceleration voltages by means of the primary and secondary electron beam irradiation devices 9' and 11'.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing a tape-shaped optical fiber cable mainly used by being housed in an optical fiber cable.

[0002]

2. Description of the Related Art FIGS. 2A and 2B are cross-sectional views of a tape-shaped optical fiber cable widely used as a main member of an optical fiber cable. In FIG. 2, 2
1 is a glass fiber, 22 is a strand coating, 23 is an optical fiber, 24 is a batch coating, 25 is a tape-shaped optical fiber core,
Reference numeral 26 denotes a connection collective covering, and reference numeral 27 denotes a connection-type optical fiber ribbon. A tape-shaped optical fiber core 25 shown in FIG.
A plurality of optical fibers 3 having, for example, an outer diameter of 250 μm, each formed by applying a wire coating 22 made of an ultraviolet curable resin to a μm glass fiber 21 are arranged in parallel, and a collective coating 24 made of a resin is applied so as to cover them. 0.3mm ~
It is a 0.5 mm tape shape.

[0003] Further, a connection type tape-shaped optical fiber core 27 shown in FIG. 2 (B) is obtained by further arranging a plurality of tape-shaped optical fiber cores 25 similar to the above-mentioned tape-shaped optical fiber core in parallel. Batch covering 2 made of resin so as to cover
6, wherein a plurality of tape-shaped optical fiber core wires shown in FIG. 2A are connected in the width direction. Since the connection type tape-shaped optical fiber core 27 is often divided into a plurality of tape-shaped optical fiber cores at the terminal portion when used, it is sometimes called a split-type tape-shaped optical fiber core. Here, unless otherwise specified, the tape-shaped optical fiber core is the one shown in FIG.
It refers to both the configuration of FIG. 2A and the configuration of FIG.

In FIGS. 2A and 2B, the wire coating 22 on the glass fiber 21 is depicted as a single layer, but the wire coating 22 is generally made of a relatively soft ultraviolet curable resin. A layer made of a relatively hard UV-curable resin is provided on the layer made of, and a colored layer is further provided thereon. In some cases, a coloring layer is not provided. Further, the number of layers of the wire coating 22 is not limited to two or three.

[0005] Further, in using the above-mentioned tape-shaped optical fiber in the production of an optical fiber cable, in many cases, a slot member or a spacer member provided with a plastic molded body having a groove formed on the surface around a strength member. A plurality of tape-shaped optical fiber cords are stacked and accommodated in a groove of a container called "etc."

[0006] In addition, the batch coating or the joint batch coating of a tape-shaped optical fiber core according to the prior art is performed by applying an ultraviolet-curable resin onto a parallel optical fiber or a parallel tape-shaped optical fiber core and applying the resin to the resin. It is formed by irradiating and curing ultraviolet rays. In this coating forming step, after applying the ultraviolet curing resin, the uncured resin is exposed to the air until it enters the ultraviolet irradiation device.At that time, oxygen is absorbed on the surface of the resin, and the presence of the oxygen causes Irradiation with ultraviolet light can suppress the curing of the resin. Therefore, the surface of the resin may remain in a state where it is not completely cured. In addition, a photoinitiator is added to the ultraviolet curable resin in order to promote curing by irradiation with ultraviolet light, but if there is a resin that does not contribute to the curing reaction of the photoinitiator, it blooms on the surface and the surface becomes blunt. May be sticky.

[0007] On the other hand, the manufactured tape-shaped optical fiber is usually wound up in layers on a bobbin. At that time, the surface portion of the coating layer made of the ultraviolet curable resin is not completely cured or the photoinitiator is in a bloomed state, and if the surface is sticky, the tape-shaped optical fiber core is removed from the bobbin in the next step. When the wire is drawn out, a tack phenomenon may occur in which the wound tape-shaped optical fibers of the respective layers adhere to each other and cannot be drawn out smoothly. In a remarkable case, the collective coating or the joint collective coating of the tape-shaped optical fibers in each layer may be broken if the collective covering or the joint collective covering adhere to each other and are forcibly pulled out.

Therefore, a method has been adopted in which the collective coating or the joint collective coating of the tape-shaped optical fiber is made slippery to reduce the adhesiveness. The method described in JP-A-7-209564 is to add a fluorine-containing organic compound to an ultraviolet-curable resin. Also, JP-A-8-2174
The method described in Japanese Patent Publication No. 95 is a method in which a silicone structure is contained in an ultraviolet curable resin or silica fine particles are added to a resin material. In addition, Japanese Patent Application Laid-Open No.
No. 1 discloses a method of connecting an ultraviolet curable resin coating device and an irradiation device with a connecting cylinder to fill an inert gas and eliminate oxygen.

[0009]

However, fluorine organic compounds or organic compounds having a silicone structure are
Poor compatibility with urethane acrylate resins or epoxy acrylate resins generally used as UV-curable resins, and phase separation easily occurs during storage. Further, when the production linear speed in the process of applying the ultraviolet curing resin to the tape-shaped optical fiber core and applying ultraviolet radiation is increased, a shear force is applied to the resin at a die portion in the coating apparatus, so that phase separation easily occurs.

When a resin is applied onto an optical fiber while phase separation is occurring and ultraviolet rays are applied, the surface energy of the base resin and the additive such as a fluorine-based organic compound is different, and irregularities are formed on the surface of the collective coating or the joint collective coating. It is formed. When an optical fiber cable is formed by stacking and accommodating a tape-shaped optical fiber core having irregularities on the surface of such a collective coating or a joint collective coating, an uneven side pressure acts on the optical fiber and the transmission loss of the optical fiber. And other characteristics are deteriorated. Also, when silica fine particles are added, irregularities are likely to be formed on the surface of the collective coating or the joint collective coating, and the irregularities may increase the transmission loss of the optical fiber.

A method of connecting an ultraviolet curable resin coating device and an irradiation device with a connecting cylinder to fill an inert gas is a method in which oxygen around the resin immediately after leaving the coating device is removed. Is in a state where it is extremely easy to cure, so that the resin is hardened even by a slight leak of ultraviolet light, and there is a problem that the clogging of the die at the outlet of the coating apparatus is apt to occur.

The present invention suppresses the occurrence of a tack phenomenon based on the adhesiveness of the coating surface, eliminates the problem of forming unevenness on the coating surface due to the phase separation of the UV-curable resin or clogging the dice, and also improves the transmission characteristics. An object of the present invention is to provide a good method for producing a tape-shaped optical fiber core.

[0013]

According to the method of the present invention, a plurality of optical fibers each having a wire coated on a glass fiber are arranged in parallel and a batch coating is performed so as to cover them. Method for manufacturing a tape-shaped optical fiber core coated, or a method for manufacturing a connection-type tape-shaped optical fiber core in which the tape-shaped optical fiber core is further parallel-coated so as to cover them and collectively cover them. An electron beam curable resin is applied so as to cover a plurality of optical fibers arranged in parallel or a plurality of tape-shaped optical fiber cores arranged in parallel, so that the accelerating voltages of the resin are different. Irradiation of primary and secondary electron beams is carried out to cure and form a batch coating or a joint batch coating.

[0014] The tape-shaped optical fiber core thus manufactured is cured by irradiating electron beams having different accelerating voltages by using an electron beam curable resin for collective coating or joint collective coating. Both the part very close to the surface and the part far from the outer surface can be sufficiently cured.
In addition, since the resin is an electron beam-curable resin, addition of a photoinitiator is not required, and stickiness due to bloom of the photoinitiator does not occur. Since the adhesiveness of the surface of the collective covering or the collective covering is suppressed by these, the tape-like optical fiber core wire or the like can be smoothly fed out from the bobbin.

In the manufacturing method of the present invention, only the collective coating and the joint collective coating are made of the electron beam curable resin. When an electron beam is applied to the optical fiber coating using an electron beam-curable resin, the glass fiber inside will be irradiated with a strong electron beam, causing lattice defects to occur in the glass fiber and deteriorating the characteristics. There is fear. In order to avoid this, the optical fiber is not covered with the electron beam irradiation type resin but is cured by, for example, ultraviolet irradiation using an ultraviolet curing type resin.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A tape-shaped optical fiber core according to the manufacturing method of the present invention is the same as that shown in FIG.
It has the same cross section as (B), but differs from the prior art in that the blanket coating 24 or the combined batch coating 2
6 is formed by applying an electron beam-curable resin and irradiating primary and secondary electron beams. FIG. 1 is a diagram showing a main part of a manufacturing process of a tape-shaped optical fiber core wire according to the present invention, wherein 1 is a supply bobbin, 2 is an optical fiber,
Is a dancer roller, 4 is a guide roller, 5 is a concentrator,
6, 6 'is a resin supply device, 7, 7' is a coating device, 8,
8 ', 10 and 10' are connecting tubes, 9 and 9 'are primary electron beam irradiation devices, 11 and 11' are secondary electron beam irradiation devices, 12
Denotes a tape-shaped optical fiber core, 13 denotes a connection type tape-shaped optical fiber core, 14 denotes a take-up machine, 15 denotes a dancer roller, and 16 denotes a winding bobbin.

Each of the plurality of supply bobbins 1 is wound with an optical fiber 2 provided with a wire coating on a glass fiber manufactured by a manufacturing process (not shown). The optical fibers 2 respectively fed from the supply bobbin 1 reach the concentrator 5 via the dancer roller 3 and the guide roller 4. In the case of manufacturing an eight-fiber connection type optical fiber ribbon having the form shown in FIG. 2B, eight supply bobbins 1 are used, and the eight fed out optical fibers 2 are collected in a concentrator 5. In the concentrator 5, eight optical fibers 2 are connected to 4
The optical fibers 2 are divided into two groups each, and the optical fibers 2 are arranged in parallel and directed toward the coating device 7. The coating device 7 includes a dice having two dice holes. Each of the optical fiber groups is passed through another dice hole, and an electron beam curable resin is supplied from the resin supply device 6 for each group to perform coating.

Each of the two die holes of the coating device 7 is
While the four optical fibers 2 pass, an electron beam-curable resin is applied on each of the four optical fibers 2, and subsequently enters the primary electron beam irradiation device 9 and is irradiated with an electron beam. The electron beam irradiation device 11 is irradiated with an electron beam to cure the resin and form a batch coating. Then, two tape-shaped optical fibers 12 are formed.

At this time, the acceleration voltage of the primary electron beam irradiation device and the acceleration voltage of the secondary electron beam irradiation device are set to different voltages. For example, a primary acceleration voltage of 30 kV or more, 60 kV
And a secondary acceleration voltage of 60 kV or more and 250 kV
The following is assumed. Further, the primary and secondary acceleration voltages may be reversed. In addition, the primary and secondary electron beam irradiation is performed from two or more directions around the applied line, respectively, so as to irradiate from the periphery of the collective coating or the joint collective coating.

The reason why the acceleration voltage of one of the primary and secondary electron beam irradiation devices is set to 30 kV or more and less than 60 kV and the other acceleration voltage is set to 60 kV or more and 250 kV or less is as follows. When the accelerating voltage exceeds 60 kV,
The electron beam does not contribute very much to the hardening of the portion very close to the surface of the batch coating, that is, the portion about several μm from the surface, but mainly contributes to the hardening of the portion farther than the portion very close to the surface. On the other hand, when the acceleration voltage is less than 60 kV, the electron beam sufficiently contributes to the hardening of a portion extremely near the surface. However, if the accelerating voltage is low, it takes time to cure the portion far from the surface. Therefore, one of the accelerating voltages is set to less than 60 kV to promote the hardening of the portion extremely close to the surface, and the other is set to the accelerating voltage of 60 kV or more to accelerate the hardening of the portion other than the portion mainly close to the surface. .

When the acceleration voltage is less than 30 kV,
Since the effect of accelerating hardening is low, the smaller accelerating voltage is 30
kV or more. If the acceleration voltage exceeds 250 kV, the electron beam may reach the glass fiber in the optical fiber inside the collective coating, causing a lattice defect in the glass fiber.
V or less. Further, as the electron beam irradiation device, a device such as a microminiature electron beam irradiation device Min-EB manufactured by Ushio Inc. can be used.

It is also possible to combine the primary and secondary electron beam irradiation devices into a device having a plurality of electron beam emitting units. In this case, even if a single device emits electron beams of different accelerating voltages from different electron beam emitting units, it corresponds to the primary and secondary electron beam irradiation devices according to the present invention. I do.

Further, a period from when the coating device 7 exits to the primary electron beam irradiating device 9, and a period between the time when the primary electron beam irradiating device 9 exits and enters the secondary electron beam irradiating device 11, It is desirable that the connection is made by connecting the cylindrical connecting tubes 8 and 10 to form an inert gas atmosphere such as nitrogen gas so that the uncured resin does not come into contact with air. Further, it is preferable that the connecting cylinder 8 can be divided into two parts so as not to hinder the work such as the initial wiring. In addition, it is desirable that the inside of each electron beam irradiation apparatus is also in an inert gas atmosphere. In addition, even if the space between the coating device and the primary electron beam irradiation device is covered with a connecting cylinder,
In the case of electron beam irradiation, since the electron beam is sufficiently shielded so as not to leak out of the irradiation device, in the case of ultraviolet light, the problem equivalent to the occurrence of clogging of the die due to the curing of the resin at the die exit due to the leaked light is as follows. Does not happen.

In FIG. 1, eight optical fibers 2 and two tape-shaped optical fiber cores 12 from the concentrator 5 to the coating device 7 'are arranged in a direction perpendicular to the paper surface. Because it is, it is drawn as one.

Next, the two tape-shaped optical fiber cores 12
Are arranged in parallel and enter the coating device 7 ′, and the electron beam-curable resin supplied from the resin supply device 6 ′ and serving as the collective coating is collectively placed on the two tape-shaped optical fiber cores 12. The resin is applied so as to cover it, and subsequently enters the primary and secondary electron beam irradiation devices 9 'and 11' to irradiate the resin with an electron beam to cure the resin. The accelerating voltage of the primary and secondary electron beam irradiation devices 9 'and 11' is set to 30 kV or more and less than 60 kV, and the other accelerating voltage is set to 60 kV or more and 250 kV, as in the case of the batch coating. The following is assumed. The connecting tubes 8 'and 10' are connected to the connecting tubes 8 and 10 respectively.
It has the same configuration and function as described above, and is filled with an inert gas such as nitrogen gas. The connected tape-shaped optical fiber core 13 that has exited the electron beam irradiation device 11 ′ is wound around a winding bobbin 16 through a take-up machine 14 and a dancer roller 15.

In the case of manufacturing a four-core optical fiber ribbon having the form shown in FIG. 2A, four optical fibers 2 are arranged in parallel by a concentrator 5 and supplied to a coating device 7. . The coating device 7 has one die hole. Then, the coating device 7 'to the electron beam irradiation device 1
1 'is detached, and the tape-shaped optical fiber core 12 that has exited the electron beam irradiation device 11 is directly taken by a take-off machine 14, whereby a four-core tape-shaped optical fiber core can be manufactured.

FIG. 1 shows an example in which, when manufacturing the connection type tape-shaped optical fiber ribbon of the form shown in FIG. 2B, both the collective coating and the collective collective coating are formed of an electron beam-curable resin. However, in the case of a connection type tape-shaped optical fiber core wire, since it is not taken up on the take-up reel when it is covered with the inner batch coating, only the connection batch coating is formed with the electron beam curing resin. Alternatively, the inner batch coating can be formed of an ultraviolet curable resin.

[0028]

EXAMPLE Table 1 shows that four tape-shaped optical fiber cores were manufactured by changing the accelerating voltage of each of the primary and secondary electron beam irradiation devices in various ways, and the performance of the completed tape-shaped optical fiber core was measured. It is a table | surface which shows the result of checking. The optical fiber ribbon was manufactured under the following conditions. Outer diameter 125
A single mode glass fiber mainly composed of quartz glass of μm is coated with two layers of an ultraviolet curable resin made of a urethane acrylate resin, and a colored layer made of an ultraviolet curable resin is further formed to form an optical fiber having an outer diameter of about 250 μm. Manufactured.

Then, four optical fibers are arranged in parallel, and an electron beam curable resin which is to be collectively coated is coated by a coating device so as to cover them, thereby forming a tape having a thickness of 0.4 mm.
The applied resin was irradiated with an electron beam having an acceleration voltage shown in Table 1 by a primary and secondary electron beam irradiation device to be cured. At this time, the production linear speed was set to 500 m / min, and the winding tension at the time of winding on the winding bobbin was set to 1.5N. The connection between the coating device and the primary electron beam irradiation device and between the primary electron beam irradiation device and the secondary electron beam irradiation device are connected by a connecting cylinder, and the inside thereof is filled with nitrogen gas. The cured electron beam curable resin was prevented from coming into direct contact with air.

The electron beam curable resin of the batch coating is made of P
A urethane acrylate-based oligomer obtained by copolymerizing PG (polypropylene glycol), TDI (tolylene diisocyanate), and HEA (hydroxyethyl acrylate) is used as a base oligomer, and tetraethylene glycol diacrylate and trianul isocyanurate are added as diluting monomers. The used resin was used.

The performance of the completed optical fiber ribbon was examined as follows. Transmission loss is wavelength 1.5
At 5 μm, the transmission loss of each optical fiber was measured by OTDR, and the average value was obtained. Transmission loss is 0.18dB
If it is / km to 0.22 dB / km, it is "good", but if it exceeds that range, it is "bad". The gel fraction is
Strip the bulk coating with a razor and apply 60
It was immersed at 16 ° C. for 16 hours, and calculated from the weight change before and after that. If the gel fraction is 90% or more, the curing is sufficiently advanced and is “good”. The tackiness of the surface is checked by checking whether the tape-shaped optical fiber core wound on the reel can be smoothly fed out from the reel. Was not able to be paid out, it was determined that there was tackiness.

[0032]

[Table 1]

According to the results, the case numbers 1 and 2 have acceleration voltages of 40 kV and 150 kV, or 240 kV or 240 kV.
kV and 40 kV, and one acceleration voltage is 30 kV or more and less than 60 kV, and the other acceleration voltage is 60 kV.
It is in the range from V to 250 kV. In this case, the transmission loss, the gel fraction and the surface tackiness are all good.

In the case of Case No. 3, the primary and secondary acceleration voltages are both 70 kV, and both values are 6 kV.
0 kV or more. In this case, the transmission loss and the gel fraction are good, but the tackiness of the surface is poor. The reason why the surface tackiness is poor is thought to be that the acceleration voltage is high in both the primary and secondary, so the hardening of the very surface part of the batch coating does not proceed and the part very close to the surface is in a semi-hardened state. Can be

In case number 4, the acceleration voltage is a combination of 30 kV and 50 kV,
less than kV. In this case, the transmission loss and tackiness are good, but the gel fraction is as low as about 80%. The reason why the tackiness is good and the gel fraction is low is that, because the acceleration voltage is low for both, the curing of the part very close to the surface has progressed sufficiently, but the curing of the part far from the surface and the average curing are sufficient. Probably because he did not go to.

In case number 5, the acceleration voltage is a combination of 50 kV and 300 kV.
0 kV or more and less than 60 kV, but the other is 60 kV
It is higher than the range of kV or more and 250 kV or less. In this case, the gel fraction and tackiness are good, but the transmission loss is as large as 0.256 dB / km. The reason for the poor transmission loss is considered to be that the electron beam with a high accelerating voltage affected the internal optical fiber and caused lattice defects in the glass fiber.

[0037]

The method of manufacturing a tape-shaped optical fiber according to the present invention is directed to a method for covering an electron beam so as to cover a plurality of optical fibers arranged in parallel or a plurality of tape-shaped optical fibers arranged in parallel. A curable resin is applied and the resin is irradiated with electron beams of different accelerating voltages by primary and secondary electron beam irradiation devices to be cured to form a collective coating or a collective coating. While accelerating the curing of the part very close to the surface of the collective coating, the collective coating other than the surface or the joint collective coating part can be sufficiently cured.

Further, since it is an electron beam-curable resin, it is not necessary to add a photoinitiator, so that the photoinitiator does not bloom on the surface and the surface does not stick. Further, by these, it is possible to manufacture a tape-shaped optical fiber core wire which suppresses the tack phenomenon by suppressing the adhesiveness of the surface and has a good transmission loss.

Further, by covering the space between the coating device and the electron beam irradiation device with a connecting cylinder so that the applied wire does not come into contact with air, it is possible to prevent curing of the electron beam-curable resin from being caused by air contact. Can be prevented.

[Brief description of the drawings]

FIG. 1 is a view showing a main part of a manufacturing process of a tape-shaped optical fiber core according to the present invention.

FIGS. 2A and 2B are cross-sectional views of an optical fiber ribbon.

[Explanation of symbols]

 1: Supply bobbin 2: Optical fiber 3: Dancer roller 4: Guide roller 5: Concentrator 6, 6 ': Resin supply device 7, 7': Coating device 8, 8 ', 10, 10': Connecting cylinder 9, 9 ': Primary electron beam irradiator 11, 11': Secondary electron beam irradiator 12: Tape-shaped optical fiber core 13: Connected tape-shaped optical fiber core 14: Take-off machine 15: Dancer roller 16: Winding bobbin 21: Glass fiber 22: Wire coating 23: Optical fiber 24: Collective coating 25: Tape-like optical fiber core 26: Connection collective coating 27: Connection type tape-type optical fiber core

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 2H001 BB15 BB22 KK02 KK17 MM02 2H050 AB04X BA17 BA21 BA22 BB17R BB17S BB34R BB34S BC04 BD02 4G060 AA20 AC16 AD44 CB22

Claims (3)

[Claims] 1. A method for producing a tape-shaped optical fiber core fiber in which a plurality of optical fibers each having a wire coated on a glass fiber are arranged in parallel and collectively coated so as to cover them.
Or, in the method of manufacturing a connection type tape-shaped optical fiber core in which the tape-shaped optical fiber cores are further parallel-coated and the connection collective coating is performed so as to cover them, a plurality of optical fibers arranged in parallel or An electron beam-curable resin is applied to a plurality of tape-shaped optical fiber cores arranged in parallel so as to cover them, and the resin is irradiated with primary and secondary electron beams having different accelerating voltages to be cured and coated at once. Alternatively, a method for producing a tape-shaped optical fiber core, characterized in that the connection collective coating is performed. 2. The primary and secondary electron beam irradiation devices,
2. The method according to claim 1, wherein one of the accelerating voltages is 30 kV or more and less than 60 kV, and the other accelerating voltage is 60 kV or more and 250 kV or less. 3. 3. After the electron beam-curable resin is applied, the resin is applied until it enters a primary electron beam irradiation device and until it leaves the primary electron beam irradiation device and enters a secondary electron beam irradiation device. 3. The method according to claim 1, wherein the electron beam-curable resin is exposed to an inert gas atmosphere so as not to be exposed to air.