JP2011191689A - Coated optical fiber and method of producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a coated optical fiber that has superior identifiability, while keeping high quality, and to provide a method of producing the coated optical fiber. <P>SOLUTION: The coated optical fiber 11 includes: a glass fiber 21; a covering layer 22 arranged on the outer periphery of the glass fiber 21; a colored layer 23 which is arranged on the surface of the covering layer 22 and comprises a colored resin; and an identification part 12 comprising a ring mark 13 arranged by applying a ring mark ink to the surface of the colored layer 23. A contact angle θ of the mark ring ink with the surface of the colored layer 23 is <30°. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an optical fiber core in which a glass fiber is covered with a resin layer and a method for manufacturing the same.

  In recent years, the demand for high-speed data communication has increased due to the rapid spread of the Internet, and the service of FTTH (Fiber To The Home) that installs an optical fiber to each home is expanding. As the construction of this FTTH system is accelerated, a multi-core loose tube cable is being studied. Although the optical fiber core wire can usually identify, for example, 12 cores by the color of the colored layer in which the coating is colored, there is a further increase in the number of cores. Therefore, there is a need to identify each line other than the color of the colored layer.

As an optical fiber having such discriminability, an optical fiber core wire in which a glass fiber is coated with a resin, a colored layer provided on the outer periphery, and between the optical fiber core wire and the colored layer are visually recognized from the outside. There is known an optical fiber colored core wire that is roughly configured from a marker portion that can be provided (see, for example, Patent Documents 1 to 6).
Also known is an optical fiber core wire having a ring-shaped color mark on or in a synthetic resin layer outside the coating of the optical fiber core wire (see, for example, Patent Document 7). ).

JP 2004-12680 A Japanese Patent Laid-Open No. 2004-77536 Japanese Patent Laid-Open No. 2004-77537 Japanese Patent Laid-Open No. 2004-77538 Japanese Patent Laid-Open No. 2004-77539 JP 2004-157193 A Japanese National Patent Publication No. 11-513130

When the optical fiber colored cores disclosed in Patent Documents 1 to 6 are left in a high-temperature environment (about 85 ° C.), the ink component in the marker portion inside the colored layer penetrates and diffuses into the coating of the optical fiber core. However, it may reach the interface between the glass fiber and the coating. Then, peeling occurs due to a decrease in the adhesion between the glass fiber and the coating, which may cause a transmission loss and a decrease in the strength of the glass fiber. In particular, the penetration and diffusion of the ink into the coating is remarkable in a high temperature and high humidity environment (for example, 85 ° C. and 85% RH).
Also, when the optical fiber colored core is left in a submerged environment, water molecules are combined with the resin component of the ink, resulting in water bubbles (blisters) due to a decrease in adhesion at the interface between the ink and the colored layer, resulting in transmission loss. May increase. In particular, in the flooded environment with warm water (about 60 ° C.), the generation of water bubbles is remarkable.
As described above, the optical fiber colored core wire provided with the marking portion inside the colored layer is unavoidably deteriorated in a high temperature environment or a flooded environment.

  The optical fiber core of Patent Document 7 is provided with a color mark on a coating that is a synthetic resin layer. If the ink of the color mark with respect to the coating is not good in wettability, the ink is coated on the surface of the coating when the ink is applied. There was a risk that the film would not be coated and fixed satisfactorily. Even if the ink is fixed to the coating, the color mark disappears when it is rubbed off with a guide roller that guides the optical fiber core on the production line, or when the dirt is wiped off with alcohol during terminal processing. There was something to do. Further, if the thickness of the color mark is increased in order to reduce such peeling and disappearance, a minute bending distortion occurs in the glass fiber, and the transmission loss of the optical fiber is remarkably increased, resulting in a deterioration in quality. There was a fear.

  The objective of this invention is providing the optical fiber core wire excellent in the distinguishability, and its manufacturing method, maintaining high quality.

The optical fiber core of the present invention capable of solving the above-mentioned problems is a glass fiber, a coating layer provided on the outer periphery of the glass fiber, and a colored layer made of a colored resin provided on the surface of the coating layer. An optical fiber having an identification portion made of identification ink on the surface of the colored layer,
The contact angle of the identification ink with respect to the surface of the colored layer is less than 30 °.

Further, the optical fiber core manufacturing method of the present invention includes a glass fiber, a coating layer provided on an outer periphery of the glass fiber, a colored layer formed of a colored resin provided on a surface of the coating layer, and the coloring A method of manufacturing an optical fiber having an identification part made of identification ink on the surface of a layer,
The identification part is formed by ejecting the identification ink in the form of droplets having a contact angle of less than 30 ° with respect to the surface of the colored layer.

  In the method for producing an optical fiber core of the present invention, it is preferable to use an ink having a resin component of 15 wt% or more and 45 wt% or less as the identification ink.

According to the optical fiber core and the manufacturing method thereof of the present invention, the identification ink is fixed without being repelled on the surface of the colored layer. Thereby, even if it rubs with the guide roller in a manufacturing line, etc., the fall of the identification part from the surface of a colored layer can be prevented.
In addition, it does not disappear easily by alcohol wiping (about 5 times) to remove dirt during terminal processing work, and the thickness (height) of the ring mark is small. In addition, an increase in transmission loss can be suppressed.
Further, since the identification portion is provided on the surface of the colored layer, it is possible to eliminate problems caused by the penetration of the identification ink component of the identification portion into the coating layer or the generation of blisters.

It is a figure which shows the example of embodiment of the optical fiber core wire which concerns on this invention, Comprising: (a) is a side view of an optical fiber core wire, (b) is the side view which expanded the identification part in an optical fiber core wire. . It is sectional drawing in the ring mark part which comprises the identification part of the optical fiber core wire of FIG. It is a figure which shows the example of embodiment of the manufacturing method of the optical fiber core wire which concerns on this invention, Comprising: (a) is a side view of the optical fiber core wire in the application | coating process of a ring mark ink, (b) is a ring mark ink. It is the side view to which the identification part in an application process was expanded. It is a side view which shows the wettability of the ring mark ink with respect to a colored layer. It is a figure which shows the wettability of the ring mark ink with respect to a colored layer, Comprising: (a) is a side view in case wettability is good, (b) is a side view in case wettability is bad.

Hereinafter, an example of an embodiment of an optical fiber core and a manufacturing method for the same according to the present invention will be described with reference to the drawings.
As shown to Fig.1 (a), the optical fiber core wire 11 of this embodiment is provided with the some identification part 12 at predetermined intervals in the longitudinal direction.
As shown in FIG. 1 (b), the identification unit 12 has a plurality of ring marks 13 provided at equal intervals.

  As shown in FIG. 2, the optical fiber core wire 11 having the identification portion 12 has a coating layer 22 composed of a first coating 22a and a second coating 22b around a glass fiber 21 composed of a core 21a and a cladding 21b. Further, a colored layer 23 made of a colored resin is provided on the outer periphery thereof. The ring mark 13 constituting the identification unit 12 is provided on the surface of the colored layer 23 along the circumferential direction of the optical fiber core wire 11. The ring mark 13 is provided, for example, by ejecting and applying ring mark ink as identification ink to the optical fiber core wire 11 sent out at a predetermined linear velocity by an ink jet printer apparatus.

  In the optical fiber core wire 11, the color of the colored layer 23 is different from that of the other core wires so that the core fiber can be distinguished from the other core wires. In addition, the number of identifiable hearts is increased by the combination of the color of the ring mark 13 and the color of the colored layer 23. Further, the number of identifiable hearts may be increased by using the arrangement of the ring marks 13 as an identification code.

  The ring mark 13 preferably covers a range A of 180 ° or more and less than 360 ° on the circumference of the colored layer 23 of the optical fiber core wire 11 in order to maintain the distinguishability. Thereby, at the time of the terminal processing operation of the optical fiber core wire 11, the ring mark 13 of the identification unit 12 can be visually recognized and reliably identified from any circumferential direction.

  Moreover, as shown to Fig.1 (a), when maintaining the discriminability, it is preferable that the pitch P which is the space | interval of the identification part 12 in the longitudinal direction of the optical fiber core wire 11 is 100 mm or less, and 50 mm or less. It is more preferable that With such a pitch P, the ring mark 13 of the identification unit 12 can be visually recognized and reliably identified even if the length of the optical fiber core wire 11 that is fed out during the terminal processing operation is small. That is, it is possible to reduce the length of the optical fiber 11 that is drawn out when identifying the optical fiber 11 as much as possible.

  Moreover, as shown in FIG.1 (b), it is preferable that the width dimension W of one identification part 12 is 2 mm or more and 6 mm or less in order to maintain discriminability. When the width dimension W of one identification part 12 is less than 2 mm, it is difficult to visually recognize the identification part 12 and the discrimination is reduced. When the width dimension W of one identification part 12 exceeds 6 mm, the optical fiber core There is a risk that transmission loss as the line 11 increases.

  In order to maintain the discriminability, the discriminating unit 12 is preferably provided with 5 or more and 15 or less (six in this embodiment) ring marks 13. For example, when the width dimension W of the identification unit 12 is 5 mm, the identification unit 12 is provided with less than five ring marks 13 (5 dot ejection of ring mark ink in a section of 5 mm). When the identification unit 12 is provided with 15 or more ring marks 13 (15 dots of ring mark ink is ejected in a 5 mm section) or more, the drawing speed of the optical fiber core 11 is reduced to increase the manufacturing cost. I will invite you.

  The ring mark ink (identification ink) used for the ring mark 13 is preferably a fast-drying solvent-type dye ink. The solvent component is, for example, 13 to 90% methyl ethyl ketone (MEK), 10 to 35%. What contains the following methanol or 3-7% or less of acetone etc. is preferable. The dye component of the ring mark ink is preferably one containing 1 to 10% or less of a chromium complex dye or 5 to 15% or less of a chromium-containing dye. Further, as resin (polymer) components of the ring mark ink, styrene (ST: Styrene), methyl methacrylate (MMA), butyl acrylate (BA: Butyl Acrylate), methacrylic acid (MAA: Methacrylic acid), acrylic Those containing a copolymer (molecular weight of about 8,000 to several tens of thousands, about 15 to 45% by weight) composed of monomers such as methyl acrylate (MA) are preferable. Further, ultraviolet curable ink, electron beam curable ink, or the like having a high curing speed may be used. Furthermore, a pigment system can be used as a pigment instead of a dye system.

Next, a manufacturing method of the optical fiber core wire 11 having the identification unit 12 will be described.
First, a coating layer 22 is formed on the outer periphery of the glass fiber 21 by applying and curing a first coating 22a and a second coating 22b made of two types of ultraviolet curable urethane acrylate resins. A colored layer 23 made of an ultraviolet curable urethane acrylate ink is applied to the outer periphery of the layer 22 and cured.

Next, the ring mark ink 42 is intermittently fed from the printer head 41 of the ink jet printer apparatus as shown in FIGS. 3A and 3B while feeding the optical fiber core wire 11 having the colored layer 23 at a predetermined linear velocity. Spray and apply. When the ring mark ink 42 made of a fast-drying solvent-type dye ink is used, it can be naturally dried, so that a drying device, a curing device or the like is not particularly required. When an ultraviolet curable ink is used as the ring mark ink 42, ultraviolet rays are irradiated by an ultraviolet irradiation device after application, and when an electron beam curable ink is used as the ring mark ink 42, electrons are emitted by an electron beam irradiation device after application. Irradiate the line.
Thereby, the identification part 12 which has the some ring mark 13 on the surface of the colored layer 23 is intermittently provided in the optical fiber core wire 11 with the predetermined pitch P in the longitudinal direction.
In FIG. 1B and FIG. 3B, a drop-shaped ring mark ink 42 is applied from above. As shown in FIGS. 1B and 3B, the ring mark ink (droplet) 42 applied on the optical fiber core 11 hangs down by its own weight and lies on the side of the optical fiber core 11. When viewed from the side, a triangular mark is attached.

  Examples of the inkjet printer apparatus that ejects the ring mark ink 42 to provide the ring mark 13 include the “EXCEL MVP series” manufactured by VIDEOJET, the “Image 9000 series” manufactured by IMAJE, and the “manufactured by Hitachi Industrial Equipment Systems Co., Ltd.” Commercial products such as “PXR series” and “MK-9000 series” manufactured by Keyence Corporation can be used. These ink jet printer apparatuses have no difference except that the ink composition is different, and there is no influence of the difference in the resin composition as long as the conditions of contact angle and thickness described later are satisfied.

  The step of applying the ring mark ink 42 can be performed in a coloring step of applying and curing the colored ink that becomes the colored layer 23 on the outer periphery of the optical fiber core wire 11. That is, in the coloring process, after the colored ink that becomes the colored layer 23 is applied and cured by the coloring device, the ring mark ink 42 is sprayed and applied by the ink jet printer device installed in the coloring device, and then naturally dried. It can also be made. Further, the optical fiber core wire 11 having been provided with the colored layer 23 and stored therein is supplied at a predetermined linear velocity, and the ring mark ink 42 is sprayed and applied to the optical fiber core wire 11 and naturally dried. You can only do it.

By the way, when the ring mark ink 42 to be the ring mark 13 is applied to the surface of the colored layer 23 of the optical fiber core wire 11, whether or not the ring mark ink 42 is fixed well and reliably is determined with respect to the colored layer 23. The wettability of the ring mark ink 42 is affected.
If the wettability is poor, it is difficult to fix the ring mark ink 42 by being bounced on the surface of the colored layer 23 when the ring mark ink 42 is applied, or even if it can be fixed by a guide roller or the like in the production line. It may be rubbed and peeled off from the surface of the colored layer 23. Further, even if it can be manufactured, it disappears due to alcohol wiping (about 5 times) performed to remove dirt during the terminal processing operation, or the thickness (height) of the ring mark 13 increases, so that a slight bending strain is applied to the glass fiber 21. Will cause problems such as a significant increase in transmission loss.

Therefore, in this embodiment, in order to improve the wettability of the ring mark ink 42 with respect to the colored layer 23, an index “contact angle” is used.
Here, when the liquid is dropped on the surface of the solid, the droplet L is rounded on the surface of the solid S with its own surface tension as shown in FIG. At this time, the following equation holds.

γ _S = γ _L · cos θ + γ _SL
Where γ _S : surface tension of the solid
γ _L : surface tension of liquid
γ _SL : Interfacial tension between solid and liquid

  This equation is called “Young's equation”, and the angle θ formed by the tangent of the droplet L and the surface of the solid S is called the “contact angle”. This contact angle θ can be easily measured with a commercially available contact angle meter. For example, “DM Series” manufactured by Kyowa Interface Chemical Co., Ltd., “DSA Series” manufactured by Sanyo Trading Co., Ltd., or the like can be used.

  As shown in FIG. 5A, in a state where the contact angle θ is small, the wettability is improved because it is easy to wet. On the other hand, as shown in FIG. 5B, in a state where the contact angle θ is large, the wettability deteriorates because it is difficult to wet.

  In the present embodiment, the colored layer 23 and the ring mark ink 42 are selected so that the contact angle θ of the ring mark ink 42 with respect to the surface of the colored layer 23 is less than 30 °. That is, in the manufacturing process of the optical fiber core wire 11, the ring mark ink 42 is applied to the surface of the colored layer 23 so that the contact angle θ is less than 30 °. By applying the ring mark ink 42 so that the contact angle θ is less than 30 °, the ring mark ink 42 is fixed without being repelled on the surface of the colored layer 23 when the ring mark ink 42 is sprayed and applied. Is done. Thereby, even if it rubs with the guide roller in a manufacturing line, etc., the fall of the ring mark 13 from the surface of the colored layer 23 can be prevented.

Further, it is not easily lost by alcohol wiping (about 5 times) performed to remove dirt during the terminal processing operation, and the thickness (height) of the ring mark 13 is small. Therefore, an increase in transmission loss can be suppressed without adding a large bending strain.
Moreover, since the identification part 12 is provided on the surface of the colored layer 23, it is possible to eliminate problems caused by the penetration of the components of the ring mark ink 42 of the identification part 12 into the coating layer 22 and the occurrence of blisters.
That is, according to the optical fiber core and the manufacturing method thereof of the above embodiment, the optical fiber core 11 having excellent discrimination can be obtained while maintaining high quality, and can be identified with such high quality. The optical fiber core wire 11 having excellent properties can be easily manufactured.

Furthermore, in this embodiment, in the manufacturing process of the optical fiber core wire 11, the ring mark ink 42 having a resin component of 15 wt% or more and 45 wt% or less is applied to the colored layer 23.
If the resin component is applied to the colored layer 23 using the ring mark ink 42 of 15 wt% or more and 45 wt% or less, the contact angle θ of the ring mark ink 42 with respect to the surface of the colored layer 23 should be precisely less than 30 °. And a good ring mark 13 can be formed. In addition, it is possible to maintain a good adhesion of the ring mark 13 to the colored layer 23, and it is possible to eliminate a problem that the peeling easily occurs due to a decrease in the adhesion.

On a polypropylene (PP) sheet, colored inks (a), (b), (c), and (d) made of four types of ultraviolet curable inks that become colored layers are applied with a spin coater, and about 500 mJ / cm. A base film having a thickness of about 30 μm was produced by irradiating the ultraviolet ray ² .

  The ring mark inks (A), (B), (C), and (D) made of four types of quick-drying solvent dye inks to be ring marks are dropped on each of them, and the contact angle θ at that time is measured. did. As a result of various studies, it has been found that the contact angle θ of the ring mark ink with respect to the colored layer can be reduced and wettability can be improved by selectively combining the types of the color ink and the ring mark ink used as the colored layer.

Next, a combination of the above colored layer and ring mark ink is selected, ring marks are formed on the optical fiber core wire at various contact angles θ, and the manufacturability at that time is evaluated, and an alcohol wiping test is performed. went.
In the production of the optical fiber, specifically, a colored layer is provided on a single-mode optical fiber having an outer diameter of 250 μm, and an ink jet printer device is used on the surface of the colored layer to form a solvent-type dye ink. Ring mark ink was sprayed and applied, and a 7-dot ring mark was applied in a length of 5 mm at an interval of 50 mm. The width dimension of one dot is 0.25 mm at the widest place. The gap between dots was about 0.46 mm.
Table 1 shows the results of the combination of the colored layer and the ring mark ink, the contact angle θ, the evaluation of manufacturability, and the alcohol wiping test.

In the case of Comparative Example 1, which is a combination of a colored layer having a contact angle θ of 30 ° or more and less than 40 ° and a ring mark ink, the ring mark ink could be fixed on the surface of the colored layer. The ring mark was peeled off from the surface of the colored layer by rubbing, and the ring mark disappeared in an alcohol wiping test less than 5 times.
In the case of Comparative Examples 2 and 3 in which the contact angle θ is 40 ° or more and the combination of the ring mark ink and the ring mark ink, neither ring mark ink can be repelled on the surface of the color layer and fixed. Further, the ring mark disappeared in one alcohol wiping test.

In Examples 1 to 8, which are a combination of a colored layer and a ring mark ink with a contact angle θ of less than 30 °, the ring mark was not lost in an alcohol wiping test less than 5 times.
In particular, in Examples 1 to 5, which are a combination of a colored layer and a ring mark ink with a contact angle θ of less than 20 °, the ring mark 13 did not disappear even after about 15 alcohol wiping tests. From this, it was found that the contact angle θ is more preferably a combination of a colored layer and a ring mark ink that is less than 20 °.

  In Example 1, which is a combination of the colored layer comprising the colored ink (A) and the ring mark ink (A), the contact angle θ is less than 20 °, the manufacturability is good, and there was no problem in the alcohol wiping test. In Comparative Example 1, which is a combination of the colored layer made of ink (A) and the ring mark ink (B), the contact angle θ exceeds 30 °, and the surface of the colored layer is rubbed by a guide roller or the like in the production line. The ring mark peeled off, and the ring mark disappeared in an alcohol wiping test less than 5 times.

The ring mark ink (A) has a contact angle θ of less than 20 ° in Examples 1, 2, and 4 that are a combination of the colored inks (a), (b), and (c). Manufacturability was also good, and there was no problem in the alcohol wiping test. On the other hand, the ring mark ink (B) has a contact angle θ of less than 20 ° in Examples 3 and 5 which are a combination with the colored layers composed of the colored inks (a) and (c), and has good productivity. In the alcohol wiping test, there was no problem, but in Comparative Example 1, which is a combination with the colored layer made of the colored ink (a), the contact angle θ exceeds 30 ° and is rubbed by a guide roller or the like in the production line. As a result, the ring mark peeled off from the surface of the colored layer, and the ring mark disappeared in an alcohol wiping test less than 5 times.
From this, it is considered that the fixability of the ink can be distinguished not only by the difference in the composition of the ring mark ink but also by the combination of the ring mark ink and the colored ink, that is, the contact angle of the ring mark ink with respect to the colored layer.

  In the case of Examples 1 to 8, which are a combination of a colored layer and a ring mark ink with a contact angle θ of less than 30 °, the thickness (height) of the ring mark ink on the colored layer is 0.5 μm or more and less than 2 μm. Thus, even when wound on a bobbin after manufacture, the transmission loss was less than 0.22 dB / km as measured by an optical pulse tester (OTDR: Optical Time Domain Reflectometer) with a wavelength of 1.55 μm, and it was found that there was no problem. In order to suppress an increase in transmission loss, the thickness of the completed ring mark is important. If the thickness of the ring mark exceeds 2 μm, it is considered that an increase in transmission loss occurs.

Further, it was found that in order to keep the contact angle θ small, it is necessary to keep the ratio of the resin (polymer) component in the ring mark ink to an appropriate amount. When the resin component (in an uncured state) in the ring mark ink exceeds 45% by weight, the contact angle θ is 30 ° or more, and a good ring mark cannot be formed. Further, it was found that when the resin component was less than 15% by weight, the contact angle θ was less than 30 °, and the ring mark ink was well wetted on the surface of the colored layer, but the adhesion was reduced and easily peeled off.
That is, it was found that the resin component in the ring mark ink is preferably maintained at 15% by weight or more and 45% by weight or less in order to form a good ring mark.

11: optical fiber core wire, 12: identification part, 13: ring mark, 21: glass fiber, 22: coating layer, 23: colored layer, 42: ring mark ink (identification ink), θ: contact angle

Claims (3)

A glass fiber; a coating layer provided on an outer periphery of the glass fiber; a colored layer made of a colored resin provided on a surface of the coating layer; and an identification portion made of an identification ink on the surface of the colored layer. An optical fiber core,
The optical fiber core wire, wherein a contact angle of the identification ink with respect to a surface of the colored layer is less than 30 °. A glass fiber; a coating layer provided on an outer periphery of the glass fiber; a colored layer made of a colored resin provided on a surface of the coating layer; and an identification portion made of an identification ink on the surface of the colored layer. An optical fiber core manufacturing method comprising:
The method of manufacturing an optical fiber core wire, wherein the identification portion is formed by ejecting the identification ink in a droplet shape such that a contact angle is less than 30 ° with respect to a surface of the colored layer. A method of manufacturing an optical fiber core wire according to claim 2,
A method for manufacturing an optical fiber, wherein an ink having a resin component of 15% by weight to 45% by weight is used as the identification ink.

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