JP2013238695A - Optical fiber ribbon and optical fiber cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical fiber ribbon having excellent flame retardancy and transmission characteristics.SOLUTION: An optical fiber ribbon includes: a plurality of primary coated optical fibers 3 arranged side by side; an inner layer 5 enclosing the primary coated optical fibers 3; and an outer layer 7 covering the inner layer 5. The outer layer 7 is formed of resin, while the inner layer 5 is formed of a flame-retardant resin with the addition of a flame retardant to a base resin and having a Shore A hardness of 40 or less and an oxygen index of 25 or more, or a flame-retardant grease with the addition of a flame retardant to a base oil and having a consistency of 440 or less at room temperature, a consistency of 200 or more at -50°C, and an oxygen index of 25 or more.

Description

  The present invention relates to an optical fiber ribbon used for optical communication or the like, and more particularly to a flame retardant optical fiber ribbon.

  In recent years, the amount of information handled by computers and video equipment has increased, and there are limitations in the electric transmission system in terms of transmission capacity and transmission speed. In the future, by using optical interconnection as a wiring method for such devices, transmission over a wide band will be possible, and a small and low power consumption transmission system can be constructed.

  In order to connect between boards inside the device or between the control board and the display, it is effective to use an optical fiber ribbon capable of flexible wiring. On the other hand, when used in equipment, flame retardancy is generally required for the purpose of preventing combustion against fire. It is necessary to impart flame retardancy to the optical fiber ribbon while maintaining flexibility and size.

  In general, an optical fiber ribbon is coated with an ultraviolet curable resin at once to form a tape. Adding flame retardants to UV curable resins makes it difficult to transmit UV rays, making it difficult to make UV curable resins used for coating optical fiber tape cores difficult, and strict flame retardant standards such as vertical flame retardant It is difficult to meet.

  Further, a flame retardant optical fiber ribbon in which optical fiber strands are collectively covered with a flame retardant thermoplastic resin instead of an ultraviolet curable resin is disclosed (for example, see Patent Document 1).

  Also disclosed is a flame retardant optical fiber ribbon in which the outer perimeter of a bare fiber, generally called a primary or secondary coating itself, is formed of a flame retardant ultraviolet curable resin when manufacturing an optical fiber. (For example, see Patent Document 2).

JP 2002-214492 A JP-A-2005-008448

  However, in the invention described in Patent Document 1, since the optical fiber strand is in direct contact with the thermoplastic resin containing the flame retardant, the flame retardant particles are strongly pressed against the optical fiber strand, Anisotropic stress acts in the cross-sectional direction of the fiber strand, and a speed difference depending on the polarization direction of the transmitted light is generated, which causes polarization mode dispersion (PMD).

  Moreover, in the invention described in Patent Document 2, since a special optical fiber strand in which the primary and secondary are flame retardant ultraviolet curable resins is used, the price of the optical fiber strand is expensive.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to obtain an optical fiber ribbon excellent in flame retardancy and transmission characteristics.

In order to achieve the above-mentioned object, the following invention is provided.
(1) It has a plurality of optical fiber strands arranged side by side, an inner layer that wraps the optical fiber strands, and an outer layer that covers the inner layer, and the outer layer is made of resin, and the inner layer is a base An optical fiber ribbon comprising a flame retardant resin and a flame retardant resin having a Shore A hardness of 40 or less and an oxygen index of 25 or more.
(2) A plurality of optical fiber strands arranged side by side, an inner layer that wraps the optical fiber strand, and an outer layer that covers the inner layer, the outer layer being formed of a resin, and the inner layer being a base A fiber optic tape core comprising a flame retardant grease added with a flame retardant having a consistency of 440 or less at room temperature, a consistency of 200 or more at −50 ° C., and an oxygen index of 25 or more. .
(3) The base resin of the flame retardant resin is one or more selected from the group consisting of butyl rubber, acrylic rubber, silicone resin, fluorine resin, thermoplastic polyurethane, olefin elastomer, and block copolymer elastomer. The optical fiber ribbon as described in (1).
(4) In the flame retardant grease, the base oil is one or more selected from the group consisting of mineral oil, synthetic hydrocarbon oil, diphenyl ether oil, esters, glycols, and the flame retardant is magnesium hydroxide, huntite. One or more members selected from the group consisting of powder and hydromagnesite are selected from the group consisting of powder and hydromagnesite.
(5) The flame retardant resin or the flame retardant grease is phosphoric acid ester, phosphonic acid ester, phosphine oxide, flame retardant nitrogen-containing heterocyclic ethylenically unsaturated compound, phosphorus-containing acrylate, methacrylate functional oligomer. The optical fiber tape core according to any one of (1) to (4), further comprising a flame retardant selected from the group consisting of metal hydroxide, metal carbonate, and metal oxide line.
(6) The optical fiber ribbon according to any one of (1) to (5), wherein the outer layer is a radiation curable resin or a thermoplastic resin.
(7) The optical fiber ribbon according to any one of (1) to (6), wherein the outer layer is an ultraviolet curable resin.
(8) The outer layer is composed of phosphate ester, phosphonate ester, phosphine oxide, flame retardant nitrogen-containing heterocyclic ethylenically unsaturated compound, phosphorus-containing acrylate, methacrylate functional oligomer, metal hydroxide, metal carbonate The optical fiber tape core according to any one of (1) to (7), comprising a flame retardant selected from the group consisting of metal oxides in a proportion lower than that of the inner layer. line.
(9) An optical fiber cable using the optical fiber ribbon according to any one of (1) to (8).

  According to the present invention, an optical fiber tape core wire excellent in flame retardancy and transmission characteristics can be obtained.

1 is a cross-sectional perspective view showing an optical fiber ribbon 1 according to an embodiment of the present invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic sectional view showing an embodiment of the present invention. The optical fiber ribbon 1 of the present invention has a plurality of optical fiber strands 3 arranged side by side and a collective coating 9 that covers the optical fiber strands 3. The collective coating 9 includes an inner layer 5 and an outer layer 7 that covers the inner layer 5. The thickness of the optical fiber ribbon 1 can be appropriately changed depending on the specification, but is 300 μm to 600 μm in accordance with the thickness of 480 μm defined in “tape optical fiber” defined in JIS C6838. It is preferable. In particular, the thickness of the optical fiber ribbon including the outer layer 7 is preferably 350 μm or less. If the outer layer is too thick, PMD characteristics are also deteriorated due to the generation of stress due to the difference in Young's modulus between the outer layer and the inner layer, which is not desirable.

[Optical fiber 3]
The optical fiber 3 is an optical fiber that is coated with a primary coating (primary) and, if necessary, a secondary coating (secondary) immediately after drawing an optical fiber made of glass or resin. In FIG. 1, there are four optical fiber strands, but the number of optical fiber strands may be two or eight, two or eight. The primary coating and the secondary coating are formed using a resin composition such as an ultraviolet curable resin, for example, an ultraviolet curable urethane acrylate, and cured by irradiation with ultraviolet rays. Usually, the diameter of the optical fiber 3 is 125 μm or 250 μm.

[Inner layer 5]
The inner layer 5 is formed using a flame retardant resin having a Shore A hardness of 40 or less and an oxygen index of 25 or more so as to wrap the entire bundle of optical fiber strands 3.

  When the Shore A hardness is 40 or less, the flame retardant resin constituting the inner layer 5 is sufficiently soft, and it is possible to prevent the flame retardant particles from pressing the optical fiber 3 and causing transmission loss. .

  The flame retardant resin constituting the inner layer 5 preferably has a viscosity at 25 ° C. of 0.5 to 600 Pa · s, and more preferably has a viscosity at 25 ° C. of 5 to 140 Pa · s. 5 to 60 Pa · s is more preferable. Regarding the viscosity at 25 ° C. of the flame retardant resin constituting the inner layer 5, if less than 0.5 Pa / s, the fluidity is too high, and if it exceeds 600 Pa / s, the viscosity is too strong and it is difficult to apply the resin.

Here, the Shore A hardness is measured based on the amount of movement of the pusher when the pusher of the durometer is pressed against the resin.
Moreover, the viscosity here is a viscosity of the flame retardant resin after blending the flame retardant, and is defined by JIS K7117-2 (a method for measuring viscosity at a constant shear rate using a rotational viscometer).

  The flame retardant resin constituting the inner layer 5 is a base resin selected from one or more groups selected from the group consisting of butyl rubber, acrylic rubber, silicone resin, fluorine resin, thermoplastic polyurethane, olefin elastomer, and block copolymer elastomer. The flame retardant is added. In addition, as a block copolymer type | system | group elastomer, an ethylene-ethyl acrylate copolymer (EEA) can be used.

  The inner layer 5 may be formed of a flame retardant grease obtained by adding a flame retardant to a base oil and having a consistency of 440 or less at room temperature, a consistency of 200 or more at −50 ° C., and an oxygen index of 25 or more.

  When the consistency at room temperature exceeds 440, the fluidity of the flame retardant grease is very high, and it becomes difficult to enclose it as the inner layer 5. On the other hand, when the consistency at −50 ° C. is less than 200, it becomes too hard, the PMD characteristics are deteriorated, and the formation of the inner layer 5 becomes difficult.

  One or more base oils are selected from the group consisting of mineral oil, synthetic hydrocarbon oil, diphenyl ether oil, esters, and glycols.

  The consistency here is the blending consistency (1/10 mm) shown in JIS K2220 (2003), and is determined based on the depth of penetration of the cone into the grease.

  Flame retardants added to the flame retardant resin or flame retardant grease constituting the inner layer 5 are phosphoric acid esters, phosphonic acid esters, phosphine oxides, flame retardant nitrogen-containing heterocyclic ethylenically unsaturated compounds, phosphorus content Contains a flame retardant selected from the group consisting of acrylate, methacrylate functional oligomer, metal hydroxide, metal carbonate, metal oxide. As content, it is preferable to add a flame retardant 20-120 mass parts with respect to 100 mass parts of base resin, and it is more preferable to add 60-100 mass parts. If the amount of the flame retardant is too small, the flame retardancy is insufficient, and if the amount of the flame retardant is too large, microbends are generated.

  It is preferable that the thickness of the inner layer 5 (that is, the thickness of the portion A in FIG. 1) from the line connecting the tops of the optical fiber strands 3 provided side by side is 32 μm or less. If the inner layer 5 is too thick, the optical fiber ribbon 1 will be thick.

[Outer layer 7]
The outer layer 7 is a radiation curable resin or a thermoplastic resin, and more preferably an ultraviolet curable resin.

If the entire optical fiber ribbon 1 has sufficient flame resistance due to the presence of the inner layer 5, the outer layer 7 does not necessarily have flame retardancy, but the outer layer 7 also contains a flame retardant and is flame retardant. It is preferable to have properties.
As the flame retardant added to the outer layer 7, the same flame retardant as the flame retardant added to the inner layer 5 can be added, but the content of the flame retardant of the outer layer 7 is lower than the content of the flame retardant of the inner layer 5. preferable. This is because the coating with a smaller amount of flame retardant is easier to perform.

  The outer layer 7 has a thickness of 10 μm or more. If the outer layer is too thin, molding is difficult. The thickness of the outer layer is preferably 100 μm or less. If the thickness of the outer layer is too thick, the diameter of the optical fiber 3 is often 250 μm. Therefore, the thickness of the optical fiber ribbon is the “tape-type optical fiber” defined in JIS C6838. This is because there is a high possibility of exceeding the prescribed thickness of 480 μm.

  As the thermoplastic resin used for the outer layer 7, any of polyvinyl chloride resin, fluorine resin, polyethylene resin, polyethylene copolymer resin, acrylic rubber, polyamide resin, polyester resin, and polyether resin may be used. You may mix and use seed | species or more resin. Examples of the polyethylene resin include high-density polyethylene, linear low-density polyethylene, and high-pressure low-density polyethylene, and any of them may be used. As the polyethylene copolymer resin, any of ethylene-vinyl acetate copolymer resin (EVA), ethylene-ethyl acrylate copolymer resin (EEA), and ethylene-methyl acrylate (EMA) may be used.

  As the radiation curable resin or the ultraviolet curable resin used for the outer layer 7, a general radiation curable resin or an ultraviolet curable resin used for coating an optical fiber, such as an acrylate resin, can be used.

  Moreover, when using the metal hydrate flame retardant of aluminum hydroxide or magnesium hydroxide as a flame retardant, it is preferable to use that whose average particle diameter is 1.5 micrometers or less. The average particle diameter is determined by measuring the diameter of a flame retardant exposed to a cross-section in which an appropriate portion of a metal hydrate or a compound is brittlely broken under 50 microscopes. If the average particle diameter is too large, the outer layer 7 applies stress to the optical fiber 3 from above the inner layer 5 during coating, causing transmission loss.

  In addition, although the optical fiber ribbon 1 has only the inner layer 5 and the outer layer 7, the structure which provides a 3rd layer coating | cover is not excluded completely. However, since the number of steps for coating increases and the core separation becomes difficult, the third layer coating is rarely provided.

(Effect of optical fiber ribbon 1 according to the present invention)
Since the optical fiber tape core wire 1 according to the present invention can add a large amount of a flame retardant to the inner layer 5, it has a high degree of flame retardancy.

  Further, in the optical fiber ribbon 1 according to the present invention, the inner layer 5 is made of a flame retardant resin or flame retardant grease having specific properties, and the inner layer 5 is soft, so that the flame retardant particles are light. It is possible to prevent a transmission loss from occurring due to the fiber strand 3 being pressed.

  In addition, since the optical fiber ribbon 1 according to the present invention is composed of the inner layer 5 made of a resin that is not an ultraviolet curable resin or the like, there is no need to worry about the ultraviolet transparency of the resin. Can be added.

  Moreover, since the optical fiber tape core wire 1 according to the present invention does not need to make the primary and secondary of the optical fiber strand 3 flame retardant, a general optical fiber strand 3 can be used at low cost. is there.

  The optical fiber ribbon 1 according to the present invention can be used for an optical fiber cable.

Hereinafter, the present invention will be specifically described using examples and comparative examples.
[Examples 1 to 4 and Comparative Examples 1 to 4]
In order to produce the optical fiber ribbon 1 having the configuration shown in FIG. 1, a soft primary coating and a hard secondary coating made of urethane acrylate-based ultraviolet curable resin are formed on the outer periphery of a glass optical fiber having an outer diameter of about 125 μm. Further, an ultraviolet curable colorant was applied thereon to form a colored layer, which was then cured with ultraviolet rays, to produce an optical fiber 3 having an outer diameter of about 250 μm.
Four optical fiber strands 3 are arranged in parallel, and an inner layer 5 is formed by coating a flame retardant resin with an extruder, and an ultraviolet curable resin used for a general tape core wire is applied thereon. By forming the outer layer 7, a flame-retardant optical fiber ribbon 1 having a thickness of 350 to 400 μm was manufactured.
The following tests were performed on the obtained optical fiber ribbon 1.

The conditions and evaluations of each example and comparative example are shown in Table 1 below. Moreover, the kind of resin used by each Example and a comparative example is as follows.
Flame retardant resin A: 100 mass parts of resin based on ethylene-ethyl acrylate copolymer with 80 mass parts of phosphoric acid flame retardant added Flame retardant resin B: ethylene-ethyl acrylate copolymer Addition of 100 parts by weight of magnesium hydroxide as a flame retardant to 100 parts by weight of the base resin UV resin 1: UV resin thermoplastic resin for general tape cores: Polyester elastomer (Hytrel non-flame retardant grade)
Flame retardant UV resin A: UV resin flame retardant thermoplastic resin containing hydroxide flame retardant: Polyester elastomer containing brominated flame retardant (Hytrel, manufactured by Toray DuPont)

(1) Oxygen index The oxygen index was tested by the method defined in JIS K7201-2. The oxygen index is evaluated by the minimum oxygen concentration of a mixed gas of oxygen and nitrogen at 23 ° C. ± 2 ° C. necessary for the resin to maintain flammable combustion.

(2) Shore A hardness The Shore A hardness was measured by pressing a type A durometer of JIS K6253 against the surface of the inner layer 5.

(3) Viscosity The viscosity of the resin constituting the inner layer 5 is determined by using a parallel plate having a diameter of 20 mm with a viscoelasticity measuring device DAR-50 (manufactured by Rheological Instruments) using a resin before being molded. Measured under the condition of 0.0 mm.
The viscosity at 25 ° C. of the resin constituting the inner layer 5 of each example was in the range of 5 to 140.

(4) PMD measurement PMD measurement was performed by bundling a 1 km optical fiber ribbon in a coil with a diameter of 30 cm and measuring each of the four optical fibers by the Jones matrix method. And the average value of PMD value of four optical fibers was made into the PMD value of the optical fiber tape core wire. In addition, the PMD dispersion value is preferably 0.2 ps / km ^1/2 or less, more preferably 0.1 ps / km ^1/2 or less, as an optical fiber ribbon that contributes to an increase in communication capacity in wavelength multiplexing communication It is.

(5) Vertical flame retardancy test The tape core of the evaluation sample is set vertically in a test box. Set so that the flame of the burner hits 25cm below the display flag attached to the tape core. At that time, the burner and the sample are set so that they can be added at an angle of 20 °. The ignition time is 15 s, the rest time is 15 s, and this is repeated five times. The following three items are used as acceptance criteria.
i) Combustion due to after flame should not exceed 60 s.
ii) The display flag does not burn 25%.
iii) The surgical cotton is not burned by falling objects.

The tape core of Example 1 was prepared by coating the inner layer with a resin containing a phosphorus-based flame retardant such as phosphine and a UV curable resin, and having a tape thickness of 0.35 mm. Since a large amount of flame retardant can be blended by using a flexible resin for the inner layer, the outer layer can pass VW-1 even with a non-flame retardant UV resin. This is probably because the outer layer has a small thickness that can be burned and the inner layer suppresses the spread of combustion.
In Example 2, the inner layer was coated with a flame retardant resin compounded with a hydroxide system to a tape thickness of 0.31 mm without using a phosphorus flame retardant such as phosphine. The outer layer was coated with a UV curable resin, and was collectively coated to a tape thickness of 0.35 mm. It was manufactured at 100 m / min as in Example 1. The flame retardancy was able to pass VW-1 even when the outer layer was a non-flame retardant UV resin by using a highly flame retardant resin layer for the inner layer. It is considered that the flame retardance of the tape core wire is enhanced by covering the inner layer with a highly flame retardant resin as in Example 1. However, since the hardness is larger than that of Example 1, PMD is slightly increased.
In Examples 3 and 4, a thermoplastic resin was used for the outer layer. In Examples 3 and 4, the flame retardancy passed VW-1, and the PMD characteristics are also good. However, in the PMD characteristics, the PMD characteristics are larger in the third and fourth embodiments than in the first and second embodiments. This is considered to be due to the influence of thermal stress when the outer layer is produced by an extruder.

On the other hand, in Comparative Example 1, flame retardancy was attempted using a flame retardant UV resin for the outer layer. Although this UV resin has a high oxygen index, it does not cause dilution of flammable gas by containing hydroxide flame retardant or foam insulation effect by containing phosphorus flame retardant, so it is difficult in combustion test. Flame retardant is difficult, and flame retardant at 0.35 mm thickness is not successful.
In Comparative Example 2, the inner layer was coated with a general non-flame retardant UV resin and the outer layer was coated with a flame retardant thermoplastic resin. Although the flame retardancy can be achieved by increasing the thickness to 0.40 mm, the PMD characteristics are also deteriorated due to the generation of stress due to the difference in Young's modulus between the outer layer and the inner layer, which is not desirable.
In Comparative Example 3, the flame retardant UV resin was coated at a tape thickness of 0.35 mm, and in Comparative Example 4, the flame retardant thermoplastic resin was coated at a tape thickness of 0.35 mm. Both Comparative Example 3 and Comparative Example 4 passed VW-1. However, both of Comparative Example 3 and Comparative Example 4 have poor PMD characteristics. As described above, the PMD characteristics are easily influenced by the tape thickness because they are affected by the external pressure. This suggests that the external pressure applied to the fiber greatly depends on the Tg of the tape layer. The linear expansion coefficient of the resin changes greatly before and after Tg. For example, in the case of UV resin, if the temperature during curing is Tg or higher, the coating layer shrinks in the process of returning to room temperature after curing. This shrinkage becomes larger as Tg is lower, and an external pressure is applied to the fiber. The same applies to thermoplastic resins. However, it is presumed that the resin layer having different Tg is divided into two layers and the degree of shrinkage is different between the two layers, the external pressure to the fiber is different, and the PMD characteristics are lowered. Therefore, it is considered that PMD characteristics deteriorate when a single layer is coated with a highly flame-retardant resin such as Comparative Example 3 or Comparative Example 4.

[Example 5 / Comparative Example 5]
An optical fiber ribbon was prepared in the same manner as in Example 1 except that the inner layer 5 was formed using grease.
When using a flame retardant grease, four optical fiber strands 3 are arranged in parallel, and the flame retardant grease is applied to form the inner layer 5, on which an ultraviolet curable type used for general tape cores. A flame retardant tape core having a thickness of 350 to 400 μm was manufactured by applying resin to form the outer layer 7.
In addition, when apply | coating grease, it manufactured using the dispenser of the shape which arranged the several syringe with respect to the optical fiber aligned in parallel like used for manufacture of an intermittently bonding type | mold tape core wire.

The conditions and evaluations of the examples and comparative examples are shown in Table 2 below. Moreover, the kind of resin used by each Example and a comparative example is as follows.
Flame Retardant Grease A: Flame retardant compound flame retardant grease B: 100 parts by mass of paraffinic oil, 100 parts by mass of paraffinic oil, 100 parts by mass of huntite, 100 parts by mass of magnesium hydroxide, 100 parts by mass of hydromagnesite Flame retardant compound consisting of part by weight, magnesium hydroxide 200 parts by weight, hydromagnesite 100 parts by weight

(1) Consistency Consistency was tested by the method specified in JIS K2220 (2003), and the blending consistency after mixing 60 times at 25 ° C. was determined. The consistency at -50 ° C was also measured.

  In addition, the oxygen index, PMD measurement, and vertical flame retardancy test were performed in the same manner as in Example 1.

  In Example 5, a flame retardant grease, which is a mixture of paraffin oil and a flame retardant, was applied to the inner layer instead of the flexible resin, and the resin was coated thereon with a UV resin. If it adjusts to the range of suitable consistency by selecting the compounding quantity of a flame retardant, it can be made not to impair a PMD characteristic, making a tape core wire flame-retardant. When the blending amount is increased in order to increase the flame retardancy as in Comparative Example 5, the consistency becomes harder, so that stable application becomes difficult and production itself becomes impossible.

  The preferred embodiments of the present invention have been described above with reference to the accompanying drawings, but the present invention is not limited to such examples. It will be apparent to those skilled in the art that various changes and modifications can be made within the scope of the technical idea disclosed in the present application, and these are naturally within the technical scope of the present invention. Understood.

DESCRIPTION OF SYMBOLS 1 ......... Optical fiber ribbon 3 ......... Optical fiber 5 ......... Inner layer 7 ......... Outer layer 9 ......... Collective coating

Claims (9)

A plurality of optical fiber strands arranged side by side;
An inner layer that envelops the optical fiber;
An outer layer covering the inner layer,
The outer layer is formed of a resin,
The inner layer is formed of a flame retardant resin having a Shore A hardness of 40 or less and an oxygen index of 25 or more formed by adding a flame retardant to a base resin. A plurality of optical fiber strands arranged side by side;
An inner layer that envelops the optical fiber;
An outer layer covering the inner layer,
The outer layer is formed of a resin,
The inner layer is formed of a flame retardant grease having a consistency at room temperature of 440 or less, a consistency at -50 ° C. of 200 or more, and an oxygen index of 25 or more obtained by adding a flame retardant to a base oil. Fiber ribbon.   The base resin of the flame retardant resin is selected from the group consisting of butyl rubber, acrylic rubber, silicone resin, fluorine resin, thermoplastic polyurethane, olefin elastomer, and block copolymer elastomer. The optical fiber ribbon according to claim 1, wherein In the flame retardant grease,
The base oil is selected from the group consisting of mineral oil, synthetic hydrocarbon oil, diphenyl ether oil, esters, glycols,
The optical fiber tape core wire according to claim 2, wherein the flame retardant is one or more selected from the group consisting of magnesium hydroxide, huntite powder, and hydromagnesite.   The flame retardant resin or the flame retardant grease includes phosphate ester, phosphonate ester, phosphine oxide, flame retardant nitrogen-containing heterocyclic ethylenically unsaturated compound, phosphorus-containing acrylate, methacrylate functional oligomer, metal water 5. The optical fiber ribbon according to claim 1, comprising one or more flame retardants selected from the group consisting of oxides, metal carbonates, and metal oxides.   The optical fiber tape core wire according to any one of claims 1 to 5, wherein the outer layer is a radiation curable resin or a thermoplastic resin.   The optical fiber tape core wire according to any one of claims 1 to 6, wherein the outer layer is an ultraviolet curable resin.   The outer layer is composed of phosphate ester, phosphonate ester, phosphine oxides, flame retardant nitrogen-containing heterocyclic ethylenically unsaturated compound, phosphorus-containing acrylate, methacrylate functional oligomer, metal hydroxide, metal carbonate, metal oxide The optical fiber tape core wire according to any one of claims 1 to 7, further comprising a flame retardant selected from the group consisting of materials in a proportion lower than that of the inner layer.   An optical fiber cable using the optical fiber ribbon of any one of claims 1 to 8.

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