JP2009237479A - Coated optical fiber tape - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fire resistant coated optical fiber tape with little surface ruggedness. <P>SOLUTION: The tape coating comprises: a first tape coating for coating optical fiber cable cores; and a second tape coating for coating the outer periphery of the first tape coating, and the first tape coating and the second tape coating comprise an ultraviolet curing resin in which a fire resistant substance A which is phosphate, phosphonic acid ester, phosphine oxides, fire resistant nitrogen-containing heteroannular ethylenically unsaturated compound, phosphorus-containing acrylate, methacrylate functionality oligomer, and the mixture thereof, is added to an irradiation curing monomer and oligomer. In this case, only the first tape coating further contains a fire resistant substance B which is metal hydroxide, metal carbonate, metal oxide or the mixture thereof. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical fiber ribbon, and more particularly to a flame retardant optical fiber ribbon.

  There are two types of signals used for signal transmission in equipment: an electric transmission method and an optical interconnection method. With the recent increase in CPU clock frequency, in electrical transmission systems, the occurrence of crosstalk due to high-density wiring has become a problem, and it is necessary to apply a waveform shaping technique or the like. As a result, it has been found that when an electric transmission method is applied as a signal transmission method in a device, a transmission distance of about 100 m and a transmission speed of about 10 Gbps become transmission limits.

  On the other hand, if the optical interconnection method is applied as a signal transmission method in equipment, it is possible to perform transmission over a wider band compared to the electric transmission method, and use small and low power consumption optical components. Can be constructed. For this reason, the optical interconnection system is currently attracting attention as an in-device signal transmission technique that replaces the electrical transmission system.

  The optical interconnection system includes a system using an optical waveguide circuit as an optical transmission means and a system using an optical fiber, but it is desirable that all optical components used in the equipment can be stored in a space-saving manner as much as possible. Therefore, an optical fiber that can be flexibly wired and can transmit light with low loss is positioned as one of optical components suitable for optical interconnection.

On the other hand, in recent years, parts including wiring members used in electronic and electrical equipment are required to be flame retardant, and these parts are exposed to flames in order to prevent fires and reduce environmental impact. Even in such a case, it is required that no harmful gas such as hydrogen chloride gas is generated during combustion.
On the other hand, many of optical fibers and optical fiber ribbons are coated with an ultraviolet curable resin, but a general ultraviolet curable resin coating layer is not flame retardant. Therefore, in order to impart flame retardancy to the UV-curable resin-coated optical fiber core or the optical fiber tape core, for example, one or a plurality of UV-curable resin coating layers are coated and bundled into a plurality of bundles. It was necessary to coat the outer side of the optical fiber core with an outermost coating layer made of a so-called flame-retardant thermoplastic resin such as flame-retardant polyvinyl chloride (PVC) or flame-retardant polyethylene (PE) (for example, Patent Document 1).

However, when a coating layer made of a flame-retardant thermoplastic resin is provided outside the ultraviolet curable resin coating layer, there are the following problems. That is,
1) The number of manufacturing processes increases by one and productivity decreases.
2) Since the coating layer made of thermoplastic resin is formed by extrusion coating, there is a limit to reducing the coating thickness. As a result, the core cross-sectional area of the optical fiber ribbon becomes large, and the wiring inside the device is small. When stored in space, the bending diameter cannot be reduced.

Therefore, in order to reduce the core cross-sectional area of the optical fiber ribbon and to impart flame retardancy, an optical fiber and an optical fiber ribbon coated with a flame retardant ultraviolet curable resin have been proposed (for example, Patent Documents 2 and 3).
An example of the flame retardant ultraviolet curable resin is a coating material containing a halogenated epoxy resin (Patent Document 4). However, in the case of a coating material containing such a resin, if exposed to a flame, a harmful gas such as hydrogen chloride gas may be generated during combustion, which is not preferable from the viewpoint of reducing environmental burden.
On the other hand, a coating material substantially free of halogen has been proposed as the flame retardant ultraviolet curable resin (Patent Document 5).

JP 2002-214492 A Japanese Utility Model Publication 5-96811 JP 2005-326567 A JP-A-2004-83404 JP-A-2005-189816

  However, in the case of a resin containing substantially no halogen as described in Patent Document 5, a metal oxide, a metal hydroxide, a metal carbonate or the like is compared as a pigment dispersion to impart flame retardancy. It is contained in large amounts. These flame retardant pigments have a particle size of several μm to several tens of μm even when used alone, and easily aggregate in a solvent to form a particle lump and behave as larger particles. As a result, these particles or particle lumps float on the surface of the coating layer having a thickness of several tens of micrometers, and the unevenness level on the surface of the coating layer increases. As a result, when the optical fiber ribbon is connected to the connector, the optical fiber butting position in the connector is shifted from the correct position due to the increase in the unevenness level, which causes an increase in transmission loss at the connecting portion.

  The present invention has been made in view of the above, and an optical fiber tape core having a flame retardancy in which the cross-sectional area of the optical fiber ribbon is reduced and the transmission loss when the connector is connected is reduced. It is to provide.

  In order to solve the above problems, in order to solve the above-described problems and achieve the object, an optical fiber ribbon according to the present invention includes a plurality of optical fibers having a coating on the outer periphery of a glass optical fiber in parallel. An optical fiber ribbon that is collectively coated with an array tape coating, the tape coating comprising: a first tape coating that covers the optical fiber core; and a second tape coating that further covers the outer periphery of the first tape coating. And the first tape coating and the second tape coating comprise a radiation curable monomer and oligomer, a phosphate ester, a phosphonate ester, a phosphine oxide, a flame retardant nitrogen-containing heterocyclic ethylenically unsaturated compound, phosphorus UV-cured with the addition of at least one flame-retardant substance A among acrylates, methacrylate-functional oligomers and mixtures thereof The first tape coating is made of an ultraviolet curable resin further including at least one flame retardant substance B among a metal hydroxide, a metal carbonate, a metal oxide, and a mixture thereof. To do.

  Moreover, the optical fiber ribbon according to the present invention is characterized in that, in the above invention, the first tape coating and the second tape coating are flame retardant ultraviolet curable resins substantially free of halogen. To do.

  The optical fiber ribbon according to the present invention is characterized in that, in the above invention, the flame retardant substance B is at least one of aluminum trihydroxide, magnesium hydroxide, and a mixture thereof. To do.

  In the optical fiber ribbon according to the present invention, the flame retardant substance A is phosphoric acid ester or phosphonic acid ester, triphenyl phosphate, diethyl ethylphosphonate, tris (2-cyanoethyl) phosphine oxide. , And a mixture thereof.

The optical fiber ribbon according to the present invention is characterized in that, in the above invention, the flame retardant substance A is an ethylenically unsaturated phosphorus-containing urethane oligomer.
The optical fiber ribbon according to the present invention is characterized in that, in the above invention, the surface roughness of the optical fiber ribbon is 5.0 nm or less.

  The optical fiber ribbon according to the present invention has the effect of realizing a flame retardant optical fiber ribbon having a reduced cross-sectional area of the optical fiber ribbon and a reduced transmission loss when connecting the connector. Play.

  Embodiments of an optical fiber ribbon according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

FIG. 1 is a cross-sectional view schematically showing an optical fiber ribbon according to Embodiment 1 of the present invention. As shown in FIG. 1, the optical fiber ribbon 11 according to the first embodiment includes an optical fiber 12 having a primary coating layer 16 and a secondary coating layer 17 on the outer periphery of a glass optical fiber 15. The four tapes are arranged in parallel, and are collectively covered with a first tape coating 13 and a second tape coating 14.
In addition, although the optical fiber core wire 12 has shown in FIG. 1 and the optical fiber core wires 12 are arranged in contact with each other, the optical fiber core wires 12 may be disposed in a non-contact state. Moreover, the number of the optical fiber core wires 12 is not limited to four.

  The first tape coating 13 and the second tape coating 14 are made of an ultraviolet curable resin containing at least one flame retardant substance A, and only the first tape coating 13 further contains at least one flame retardant substance B. Made of resin.

Examples of the flame retardant substance A include phosphate esters, phosphonate esters, phosphine oxides, flame retardant nitrogen-containing heterocyclic ethylenically unsaturated compounds, phosphorus-containing acrylates, methacrylate functional oligomers, and mixtures thereof.
Moreover, as the flame retardant substance B contained only in the 1st tape coating 13, there exist a metal hydroxide, a metal carbonate, a metal oxide, and a mixture thereof.

  More specifically, as flame retardant substance A, in particular phosphorus can be added to the composition as a soluble and flame retardant organic derivative. Examples of suitable flame retardant organophosphorus compounds include triaryl phosphate esters and aryl phosphate esters such as trixyl phosphate esters, cyclic diphosphonate esters, and the like. Alkylated triphenyl phosphates such as isopropylated triphenyl phosphate are particularly preferred. Examples of other phosphate esters and phosphonate esters suitable for use in the present invention include alkylated polyesters such as alkyl phosphate esters, aryl phosphate esters, alkylaryl phosphate esters, alkylated polyphenyl phosphate esters. Included are alkylated polyarylphosphonates such as aryl phosphate esters, alkyl phosphonates, aryl phosphonates, alkylaryl phosphonates, and alkylated polyphenyl phosphonates. Flame retardant nitrogen-containing heterocyclic ethylenically unsaturated oligomers suitable for use in the present invention include pentafunctional melamine acrylate, tris (hydroxyethyl) isocyanurate acrylic acid or methacrylate, triallyl isocyanurate, Triaryl cyanurate and triacryloyl hexahydrotriazine are included.

As the flame retardant substance B, elements such as antimony, boron, tin, molybdenum, phosphorus, aluminum, magnesium, and zinc can be used. These elements can be included in, for example, uncured ultraviolet curable resins as oxides, hydroxides and carbonates, and as hydrates of the oxides, hydroxides and carbonates.
Examples of the metal oxide include aluminum trihydroxide and magnesium hydroxide, which are also known as alumina trihydrate. Antimony oxide, antimony oxide, antimony oxide, antimony oxide, sodium antimonate, and antimony oxide hydrate, molybdenum oxides, calcium carbonate, tin oxide, zinc stannate, zinc hydroxide stannate, zinc borate, and metaborane Other metal oxides such as barium acid are also suitable.
The flame retardant substance B is preferably included as a pigment dispersion having a small particle diameter from the viewpoint of suppressing the particle diameter from rising to the surface and suppressing the occurrence of microbend loss of the optical fiber core wire. .

  Examples of suitable components for producing a flame-retardant UV-curable resin containing no halogen according to the present invention are also disclosed in, for example, US Pat. No. 7,221,841 (Japanese Patent Laid-Open No. 2005-189816). .

  According to the present invention, only the first tape coating 13 includes at least one flame retardant substance B among metal hydroxides, metal carbonates, metal oxides, and mixtures thereof having a high flame retardant effect. There is no concern that the flammable substance B will float on the surface of the optical fiber ribbon 11 and the surface irregularities will not increase. Furthermore, both the first tape coating 13 and the second tape coating 14 include radiation curable monomers and oligomers, phosphate esters, phosphonate esters, phosphine oxides, flame retardant nitrogen-containing heterocyclic ethylenically unsaturated compounds, The addition of at least one flame retardant substance A of phosphorus-containing acrylate, methacrylate functional oligomer, and a mixture thereof can maintain high flame retardancy and reduce transmission loss when connected to the connector, and at the time of combustion An optical fiber ribbon that does not generate harmful gas such as hydrogen chloride gas can be obtained.

  The flame retardant substance A includes at least one of phosphoric acid ester or phosphonic acid ester, triphenyl phosphate, diethyl ethyl phosphonate, tris (2-cyanoethyl) phosphine oxide, and a mixture thereof, including halogen It is preferable from the viewpoint of not.

Further, the flame retardant substance A is more preferably an ethylenically unsaturated phosphorus-containing urethane oligomer. The phosphorus-containing urethane acrylate oligomer functions as a radiation curable oligomer of the present invention and as a flame retardant material of the optical fiber tape core coating composition of the present invention without adding any additional flame retardant material. sell.
However, as a matter of course, not only the phosphorus-containing urethane (meth) acrylate oligomer but also another kind of flame retardant substance A can be added. Thus, when another kind of flame retardant substance A is further added, more reliable flame retardance can be obtained.

  The flame retardant substance B is preferably at least one of aluminum trihydroxide, magnesium hydroxide, and a mixture thereof from the viewpoint of being a hydrate. That is, because it is a hydrous substance, water molecules are detached during combustion, and the effect of lowering the heat of combustion is exhibited at that time.

  Further, from the viewpoint of preventing transmission loss at the time of connector connection, the surface roughness of the optical fiber ribbon is preferably 5.0 nm or less. For example, the coating layer containing no flame retardant substance B in the second tape coating The surface roughness of the optical fiber ribbon can be reduced to 5.0 nm or less.

  Table 1 shows the specifications and performance of the examples and comparative examples.

(Examples 1-4, Comparative Examples 1 and 3)
The outer periphery of the glass optical fiber 15 having an outer diameter of about 125 μm is coated with a soft primary coating layer 16 and a hard secondary coating layer 17 made of urethane acrylate-based UV curable resin, and a colorant made of UV curable resin on the outer periphery. Was applied to form a colored layer 18 to produce an optical fiber core 12 having an outer diameter of about 250 μm. The optical fiber core is an ITU-T (International Telecommunication Union Telecommunication Standard Sector) G. A single mode optical fiber compliant with 652 was used. Then, four of the optical fiber cores 12 are arranged in a band shape, and the outer periphery of the optical fiber tape core wire collectively covered with the primary tape coating 13 which is an ultraviolet curable resin is further covered with a secondary tape coating 14 which is an ultraviolet curable resin. A coated optical fiber ribbon 11 was produced.
In addition, as shown in Table 1, the primary tape coating and the secondary tape coating were formed by mixing a flame retardant with a urethane acrylate-based non-flame retardant ultraviolet resin composed of a radiation curable monomer and an oligomer.

(Comparative Examples 2 and 4)
An optical fiber ribbon was manufactured in the same manner as in Examples 1 to 4 and Comparative Examples 1 and 3 except that the tape coating was made one layer.

  Table 2 below shows the widths and thicknesses of the obtained four-core optical fiber ribbons of Examples and Comparative Examples.

  Although the present invention is not limited to the width and thickness of the optical fiber ribbon shown here, the preferred optical fiber ribbon has a width of 1.05 to 1.20 mm, and a more preferred range is 1.06 to 1.15 mm. Moreover, as thickness preferable as an optical fiber tape core wire, it is the range of 0.29-0.40 mm, and a more preferable range is between 0.30-0.36 mm. When the width of the optical fiber ribbon is less than 1.05 mm or the thickness is less than 0.29 mm, the tape coating layer may be too thin to cover the entire circumference of the inner optical fiber. Conversely, if the width of the optical fiber ribbon is wider than 1.20 mm or thicker than 0.40 mm, the tape coating resin that exists in the valleys between the optical fibers will not be cured sufficiently, and the connector connection This is because problems such as stickiness due to uncured resin may occur during disassembly of the optical fiber ribbon.

Table 1 shows the optical characteristics, connector connectivity, and combustibility of each of the manufactured four-core optical fiber ribbons.
In addition, the test method of the optical fiber tape core wire illustrated in the Example and the comparative example is as follows.

(Connection loss)
Two optical fiber ribbons were prepared for each Example and Comparative Example, a connector was attached to the tip of the optical fiber ribbon, the connector was connected, and the connection loss was measured. Table 1 shows the average connection loss of the four optical fibers. Note that the connection loss is as follows: LD light having a wavelength (λ) of 1.30 μm is incident from one end of the optical fiber ribbon, and is connected to the single length of the same length without passing through the connector connecting portion. The light emitted from the other end of the optical fiber ribbon was measured with an optical power meter, and the difference was calculated.
For the connector connection portion, a 4-core type MT connector (Furukawa Electric Co., Ltd.) defined in JIS standard C5981 was used. The connector is structured to ensure a stable connection state by precisely positioning and butting the optical fiber in the ferrule with two guide pins and applying a constant pressing pressure with a clip.

(Concentricity)
It is defined as twice the distance between the ferrule center axis and the optical fiber core center axis defined in JIS standard C5961. The measuring method was a ferrule outer diameter reference method.

(Surface roughness)
The arithmetic mean roughness (Ra) in JIS standard B0601 is meant. The reference length L is extracted from the roughness curve in the direction of the average line, and the absolute value of the deviation from the average line of the extracted portion to the measurement curve is calculated. It is a value obtained by adding up and averaging. A film-like sample having a thickness of about 100 μm was prepared by UV curing (metal halide lamp 240 W / cm) in a nitrogen atmosphere and measured. In the case of the two-layer structure, the primary tape coating and the secondary tape coating were laminated in a thickness of 50 μm each, and a film-like sample of about 100 μm was used, and the surface roughness on the secondary tape coating surface side was measured.

(Flame retardance)
In accordance with UL standard (UL94 "flammability test method for plastic materials for equipment parts"), a flammability test was performed and judged. “VTM-1” and “VTM-2” are standards indicating the following degree of combustion.
A film-like sample with a thickness of about 100 μm, similar to the material whose surface roughness was measured, is held in a cylindrical shape, and a set of five samples is subjected to flame contact twice for 3 seconds for each sample. Classify as follows according to the total burning time and burning distance. VTM-1 means less combustible than VTM-2.

Combustion class criteria VTM-1 VTM-2
Afterflame burning time of each sample ≦ 30 seconds ≦ 30 seconds
Total burning time of 5 samples ≦ 250 seconds ≦ 250 seconds Afterflame time after second flame contact + flameless combustion time ≦ 60 seconds ≦ 60 seconds Whether or not the cotton is ignited by dripping No Yes
Existence of after-flame or flameless combustion up to 125mm mark

As described above, regarding Examples 1 to 4, good results are obtained for any of the characteristics. On the other hand, in Comparative Examples 1 and 3, the flame retardancy does not pass VTM-1, which is inferior to the examples of the present invention. This indicates that either one of the flame retardant pigment or the flame retardant organophosphorus compound is not blended, so that the flame retardancy is not sufficiently improved. Furthermore, in Comparative Example 2, since only the first tape coating containing the flame retardant pigment is formed, the connection loss and concentricity are reduced due to the unevenness of the tape coating surface during connector connection. In Comparative Example 4, no flame retardancy is observed.
As described above, the optical fiber ribbon according to the present invention makes it possible to reduce the cross-sectional area of the core and reduce the bending diameter when housed in the device. Transmission loss can be reduced and no harmful gas such as hydrogen chloride gas is generated during combustion.

It is sectional drawing which shows one Embodiment of the optical fiber tape cable core concerning one Embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Optical fiber tape core 12 ... Optical fiber core wire 13 ... 1st tape coating | cover 14 ... 2nd tape coating | cover 15 ... Glass optical fiber 16 ... Primary coating layer 17 ... Secondary coating layer 18 ... Colored layer

Claims (6)

A plurality of optical fiber cores having a coating on the outer periphery of the glass optical fiber are arranged in parallel, and the optical fiber tape core wire is collectively covered by tape coating,
The tape coating comprises a first tape coating for coating the optical fiber core wire and a second tape coating for further coating the outer periphery of the first tape coating,
The first tape coating and the second tape coating include a radiation curable monomer and oligomer, phosphate ester, phosphonate ester, phosphine oxide, flame retardant nitrogen-containing heterocyclic ethylenically unsaturated compound, phosphorus-containing acrylate. , A methacrylate functional oligomer, and an ultraviolet curable resin to which at least one flame retardant substance A is added.
An optical fiber tape characterized in that only the first tape coating is made of an ultraviolet curable resin further containing at least one flame retardant material B among metal hydroxide, metal carbonate, metal oxide, and a mixture thereof. Heartline.   2. The optical fiber ribbon according to claim 1, wherein the first tape coating and the second tape coating are flame-retardant ultraviolet-curing resin substantially free of halogen.   3. The optical fiber ribbon according to claim 1, wherein the flame retardant substance B is at least one of aluminum trihydroxide, magnesium hydroxide, and a mixture thereof.   The flame retardant substance A is at least one of phosphoric acid ester or phosphonic acid ester, triphenyl phosphate, diethyl ethylphosphonate, tris (2-cyanoethyl) phosphine oxide, and a mixture thereof. Item 4. The optical fiber ribbon according to any one of Items 1 to 3.   The optical fiber tape core wire according to any one of claims 1 to 3, wherein the flame retardant substance A is an ethylenically unsaturated phosphorus-containing urethane oligomer.   6. The optical fiber ribbon according to claim 1, wherein a surface roughness of the optical fiber ribbon is 5.0 nm or less.

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