JP2005221839A - Optical fiber and optical fiber ribbon - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical fiber which hardly injures glass fiber and hardly causes the deterioration of strength, variations of transmission loss and breakdown of a connection part even when one part of clad layer is removed upon the connection between fiber terminals by themselves. <P>SOLUTION: The optical fiber 1 is provided with a quartz glass fiber 2, a first ultraviolet curing resin layer 3 which is formed on the outer circumference of the quartz glass fiber 2, has a Young's modulus of ≥50 MPa and a glass adhesion force of 20 to 50 g/cm width and has a layer thickness of 1 to 3 μm, a second ultraviolet curing resin layer 4 which is formed on the outer circumference of the first ultraviolet curing resin layer 3 and has a Young's modulus lower than the Young's modulus of the first ultraviolet curing resin and a third ultraviolet curing resin layer 5 which is formed on the outer circumference of the second ultraviolet curing resin layer 4. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to an optical fiber and an optical fiber tape, and in particular, when a part of a coating layer is removed when connecting wire ends, the glass fiber is hardly damaged, the strength of the connection is reduced, and the transmission is reduced. The present invention relates to an optical fiber and an optical fiber tape that are unlikely to cause fluctuations in loss or disconnection.

  In recent years, with the development of optical communication networks that provide various and broadband multimedia services, the optical cables have been increased in density and the like, and optical fiber tapes are often used for optical cables. In the optical wiring from the optical cable to the subscriber system, an optical fiber tape is pulled out from the optical cable, and a predetermined optical fiber is separated into a single core in the middle of the optical fiber tape and pulled down to the subscriber's house or the like. When an optical fiber is pulled down to a subscriber's house or the like, the optical fiber for dropping is connected to the optical fiber separated using a connection box or the like called a closure. When separating a single optical fiber from an optical fiber tape, work so that other optical fibers other than the optical fiber to be separated maintain the communication state and do not disturb the communication. There is a need.

  In the optical fiber tape, multiple optical fiber strands coated with UV-curing resin or the like are placed in a line in close contact with the bare glass fiber, and the whole is integrated with a common coating layer such as UV-curing resin. I am letting. In use, this optical fiber tape is separated into a single optical fiber and connected to another optical fiber or a terminal device.

  Further, as the optical fiber, generally, a coating layer of ultraviolet curable resin composed of two layers is used, and a relatively low Young's modulus resin having a Young's modulus of 0.1 MPa as a primary coating on a bare glass fiber is used. Is formed, and a secondary layer made of a resin having a Young's modulus higher than the primary layer by 10,000 or more is formed on the outer periphery of the primary layer (see, for example, Patent Document 1).

For connecting such optical fiber strands, a part of the coating layer of the end of the optical fiber strands is once removed, and the glass fibers are butt-melted and connected (fusion splicing), V-groove, etc. Mechanical splicing, etc., is performed in which the optical axes are aligned and fixed for easy connection.
JP 2001-108874 A

  However, since the removal of the coating layer of the optical fiber as described above is performed using a dedicated jig, the glass fiber is damaged when the coating layer is removed, There was a risk of strength reduction, fluctuations in transmission loss, and disconnection.

  Therefore, the object of the present invention is to prevent the glass fiber from being scratched even when part of the coating layer is removed when connecting the wire ends, and to reduce the strength of the connecting portion, to change the transmission loss, and to prevent disconnection. An object of the present invention is to provide an optical fiber and an optical fiber tape.

  In order to achieve the above object, the present invention is formed on a silica glass fiber and an outer periphery of the silica glass fiber, has a Young's modulus of 50 MPa or more, a glass adhesion force of 20 to 50 g / cm width, and a layer thickness of 1 to 3 μm. A first ultraviolet curable resin layer, and a second ultraviolet curable resin layer formed on an outer periphery of the first ultraviolet curable resin layer and having a Young's modulus lower than the Young's modulus of the first ultraviolet curable resin; An optical fiber is provided.

  In order to achieve the above object, the present invention is formed on a silica glass fiber and an outer periphery of the silica glass fiber, has a Young's modulus of 50 MPa or more, a glass adhesion force of 20 to 50 g / cm width, and a layer thickness of 1 to 3 μm. A first ultraviolet curable resin layer, and a second ultraviolet curable resin layer formed on an outer periphery of the first ultraviolet curable resin layer and having a Young's modulus lower than the Young's modulus of the first ultraviolet curable resin; An optical fiber tape is provided, in which a plurality of optical fiber strands including the above are arranged in parallel and collectively covered with a coating layer made of an ultraviolet curable resin.

  According to the optical fiber and the optical fiber tape of the present invention, the first ultraviolet curable resin layer has a Young's modulus of 50 MPa or more, a glass adhesion force of 20 to 50 g / cm width, and a layer thickness of 1 to 3 μm. Since the resin layer having a Young's modulus lower than that of the first UV curable resin is provided as the second UV curable resin layer, the second UV curable resin layer is easily peeled off when the coating layer is removed. The first UV curable resin layer is in close contact with the quartz glass fiber. For this reason, it is possible to prevent the quartz glass fiber from being damaged when the quartz glass fiber is connected, so that the transmission characteristics do not fluctuate and fluctuations in the optical loss change amount and disconnection can be suppressed.

  An optical fiber strand according to an embodiment of the present invention is shown in FIG. The optical fiber 1 includes a quartz glass fiber 2 constituting an optical fiber, a first ultraviolet curable resin layer 3 formed in contact with the outer periphery of the quartz glass fiber 2, and a first ultraviolet curable resin layer 3. The second ultraviolet curable resin layer 4 having a Young's modulus lower than that of the first ultraviolet curable resin layer 3 and the outer periphery of the second ultraviolet curable resin layer 4 are formed. And a third ultraviolet curable resin layer 5.

  The ultraviolet curable resin for forming the ultraviolet curable resin layers 3, 4, and 5 is not particularly limited in terms of composition, but a urethane acrylate ultraviolet curable resin is preferable in terms of versatility and cost. Examples thereof include ultraviolet curable resins such as polyester urethane (meth) acrylate, polyether (meth) acrylate, and polycarbonate (meth) urethane acrylate.

  The reason why the Young's modulus of the first ultraviolet curable resin layer 3 formed on the outer periphery in contact with the quartz glass fiber 2 is set higher than the Young's modulus of the second ultraviolet curable resin formed on the outer periphery thereof is the optical fiber 1 This is to prevent the silica glass fiber 2 from being damaged when the coating is removed in the operation of connecting the two.

  The layer thickness of the first ultraviolet curable resin layer 3 is preferably 1 to 3 μm, particularly preferably 2 μm. When the thickness is less than 1 μm, a part that is not partially covered tends to be formed, and when the first ultraviolet curable resin is coated, the die and the quartz glass fiber 2 come into contact with each other, and the glass strength is lowered. This is because there is a fear. On the other hand, if it is thicker than 3 μm, there is a risk of fluctuations in transmission characteristics with respect to temperature changes such as a heat cycle, and the first ultraviolet ray formed in contact with the quartz glass fiber 2 when the coating is removed using a jig. This is because the cured resin layer 3 is easily damaged.

  The Young's modulus of the first ultraviolet curable resin layer 3 is 50 MPa or more, preferably 100 MPa or more, and most preferably 600 MPa or more. If the pressure is smaller than 50 MPa, it is difficult to obtain the effect of preventing the damage to the jig for removing the coating layer, and distortion is likely to occur due to deformation such as stretching when the coating layer is removed, resulting in an increase in transmission loss. It is because it is easy to cause. Furthermore, it is preferable that the hardness in Shore hardness D is 50 or more.

  The lower limit of the glass adhesion force of the first ultraviolet curable resin layer 3 is 20 g / cm width, preferably 30 g / cm width, most preferably 40 g / cm width, and the upper limit is 50 g / cm width. The reason why the glass adhesion is defined in this way is that when the width is smaller than 20 g / cm, peeling easily occurs during handling work such as when the optical fiber 1 is connected, and a problem that transmission loss increases is likely to occur. Because. On the other hand, when the width is larger than 50 g / cm, there is a problem that when the first ultraviolet curable resin layer 3 is completely removed from the outer periphery of the quartz glass fiber 2, the residue of the first ultraviolet curable resin layer 3 tends to remain. Because there is.

The glass adhesion is measured as follows. FIG. 2 shows an outline of a sample preparation and measurement method for measuring the glass adhesion force. First, two quartz glass slides 12a and 12b are butted together, and an ultraviolet curable resin 11 is applied on the quartz glass slides 12a and 12b to a thickness of about 50 μm (FIGS. 2A and 2B). Next, the ultraviolet curable resin 11 is cured in a nitrogen atmosphere with an irradiation amount of 500 mJ / cm ³ and an oxygen concentration of 500 ppm or less, and slits 13 are inserted so that the width of the ultraviolet curable resin 11 is 10 mm, and left and right ultraviolet curing is performed. The mold resin 11 is removed (FIG. 2C), and the sample 10 is obtained by removing one piece of the quartz slide glass 12a (FIG. 2D). By peeling the tip of the sample 10 by 90 ° in the direction of the arrow shown in FIG. 2 (e), the value when the ultraviolet curable resin 11 is peeled from the quartz slide glass 12b is determined as the adhesion force (g / cm width). ).

  FIG. 3 shows a colored optical fiber according to the embodiment. This colored optical fiber strand 20 is in contact with the outer periphery of a quartz glass fiber 22 having a diameter of 125 ± 1 μm constituting the optical fiber, and has a Young's modulus of 100 ± 20 MPa and an adhesive strength of 35 ± 5 g / cm width with glass. A first ultraviolet curable resin layer 23 made of an ultraviolet curable resin A is formed, in contact with the outer periphery of the first ultraviolet curable resin layer 23, and a urethane acrylate ultraviolet curable resin B having a Young's modulus of 1.0 ± 0.2 MPa. A second ultraviolet curable resin layer 24 made of a urethane acrylate ultraviolet curable resin C having a Young's modulus of 800 ± 100 MPa in contact with the outer periphery of the second ultraviolet curable resin layer 24. A layer 25 is formed, and a colored layer 26 made of a colored ultraviolet curable resin is formed in contact with the third outer periphery. The colored layer 26 is formed for identifying the optical fiber.

  The colored optical fiber 20 is manufactured as follows. First, the outer circumference of the silica glass fiber 22 is coated with a urethane acrylate ultraviolet curable resin A having a Young's modulus of 100 ± 20 MPa and an adhesive strength of 35 ± 5 g / cm width with a thickness of 3 μm, and an ultraviolet irradiation device (6 kW × After the first ultraviolet curable resin layer 23 is formed by irradiating and curing ultraviolet rays with a single lamp (made by Fusion), a urethane acrylate ultraviolet curable resin B having a Young's modulus of 1.0 ± 0.2 MPa is formed to a thickness of 32 μm. The second UV curable resin layer 24 is formed by coating with UV and irradiating with UV by an UV irradiation device (6 kW × 1 lamp). Next, a urethane acrylate ultraviolet curable resin C having a Young's modulus of 800 ± 100 MPa is coated with a thickness of 25 μm, and is cured by irradiating with an ultraviolet ray by an ultraviolet irradiation device (6 kW × 4 lamps) to be cured by a third ultraviolet ray. The resin layer 25 is formed, and the outer periphery of the third ultraviolet curable resin layer 25 is coated with an ultraviolet curable coloring ink (EM-3000 series: manufactured by Kansai Paint Co., Ltd.) and cured by irradiation with ultraviolet rays. Form. The drawing speed at this time was 1200 m / min.

  FIG. 4 shows an optical fiber tape according to the first embodiment. This optical fiber tape 30 is formed by arranging four colored optical fiber wires 20 colored in different colors in parallel and collectively covering with a coating layer 31 made of a urethane acrylate-based ultraviolet curable resin.

  The colored optical fiber 20 and the optical fiber tape 30 manufactured as described above were evaluated. The colored optical fiber 20 was subjected to a bending test, a breaking strength test after connection, and a loss increase after connection test. Moreover, about the optical fiber tape 30, the bending test, the side pressure characteristic, the 60 degreeC warm water test, the temperature characteristic, and the torsion test were done.

  The outline of the test for the colored optical fiber and the test for the optical fiber tape is shown below.

<Test for colored optical fiber>
(1) Bending test The colored optical fiber 20 was wound 10 times around a cylinder with a radius of 15 mm, and the amount of increase in loss was measured when light having a center wavelength λ = 1.55 ± 0.02 μm was transmitted.
(2) Break strength test after connection The test method was based on EIA / TIA-455-28B. The measurement was performed at a tensile speed of 20 mm / min with the connection portion at the center with respect to a gauge point of 500 mm. The number of samples at this time is 10.
(3) Loss increase after connection The middle of the colored optical fiber 20 having a length of 1000 m is cut, and after 15 mm of the coating of the cut end is removed by a hot stripper, fusion splicing is performed, and the connection portion is UV cured. A recoating process was performed with a resin, and the difference between the initial amount of the colored optical fiber 20 and the increase in optical loss after the connection process was measured. The number of samples at this time is 10.

<Test on optical fiber tape>
(1) Bending test It carried out similarly to the test with respect to the colored optical fiber strand 20.
(2) Side Pressure Characteristics When a side pressure of 490 N / 10 cm was applied for 1 minute or more using a flat plate, the amount of increase in optical loss when transmitting light with a center wavelength λ = 1.55 ± 0.02 μm was measured.
(3) 60 ° C. hot water test Each colored fiber core is taken in a bundle of 1000 m, dipped in a state where several meters of both ends are taken out from the water bath, and centered in 60 ° C. hot water bathing in accordance with IEC 60793-1-53 The optical loss variation at the wavelength λ = 1.55 ± 0.02 μm was measured.
(4) Temperature characteristics The test was based on IEC 60793-1-52 and EIA / TIA-455-69, and the light loss fluctuation was measured for 10 cycles at -40 to 70 ° C.
(5) Torsion test The test was performed in accordance with JIS C6838.3.4, with a load of 100 mm and a load of 1N, twisted ± 180 °, and the presence or absence of delamination between the glass fiber and the coating layer was observed with an optical microscope. Observed.

  The same procedure as in Example 1 was used except that a urethane acrylate UV curable resin D having a Young's modulus of 600 ± 100 MPa and an adhesive strength of 25 ± 5 g / cm width was used as the first UV curable resin layer 23. A colored optical fiber 20 was produced. Moreover, the optical fiber tape 30 was produced similarly to Example 1, and the test similar to Example 1 was done about the colored optical fiber strand 20 and the optical fiber tape 30.

The same procedure as in Example 1 was used except that a urethane acrylate UV curable resin E having a Young's modulus of 1000 ± 100 MPa and an adhesive strength of 25 ± 5 g / cm width was used as the first UV curable resin layer 23. A colored optical fiber 20 was produced. Moreover, the optical fiber tape 30 was produced similarly to Example 1, and the test similar to Example 1 was done about the colored optical fiber strand 20 and the optical fiber tape 30.
(Comparative Example 1)

As Comparative Example 1, a colored optical fiber was manufactured as follows. First, the outer circumference of a silica glass fiber having a diameter of 125 ± 1 μm is coated with a urethane acrylate-based ultraviolet curable resin B having a Young's modulus of 1.0 ± 0.2 MPa at a thickness of 35 μm, and is irradiated with an ultraviolet irradiation device (6 kW × 1 lamp). After the first ultraviolet curable resin layer is formed by irradiation with ultraviolet rays, a urethane acrylate ultraviolet curable resin C having a Young's modulus of 800 ± 100 MPa is coated with a thickness of 25 μm, and an ultraviolet irradiation device (6 kW × 4 lamps) ) To form a second ultraviolet curable resin layer. Next, the outer periphery of the second ultraviolet curable resin layer was coated with an ultraviolet curable colored ink (EM-3000 series: manufactured by Kansai Paint Co., Ltd.) and cured by irradiation with ultraviolet rays to form a colored layer. The drawing speed at this time was 1200 m / min. Moreover, the optical fiber tape was manufactured similarly to Example 1, and the test similar to Example 1 was done about the colored optical fiber strand and the optical fiber tape.
(Comparative Example 2)

As Comparative Example 2, a colored optical fiber was manufactured as follows. The outer circumference of a quartz glass fiber with a diameter of 125 ± 1 μm is coated with a urethane acrylate ultraviolet curable resin F having a Young's modulus of 30 ± 5 MPa and an adhesive strength of 15 ± 5 g / cm width with a thickness of 3 μm. 6 kW × 1 lamp) is irradiated with ultraviolet rays and cured to form a first ultraviolet curable resin layer, and then coated with a urethane acrylate ultraviolet curable resin B having a Young's modulus of 1.0 ± 0.2 MPa at a thickness of 32 μm. Then, ultraviolet rays were irradiated by an ultraviolet irradiation device (6 kW × 1 lamp) and cured to form a second ultraviolet curable resin layer. Next, a urethane acrylate ultraviolet curable resin C having a Young's modulus of 800 ± 100 MPa is coated with a thickness of 25 μm, and cured by irradiating with an ultraviolet ray by an ultraviolet irradiation device (6 kW × 4 lamps) to form a third ultraviolet curable resin layer. The outer periphery of the third ultraviolet curable resin layer was coated with an ultraviolet curable colored ink (EM-3000 series: manufactured by Kansai Paint Co., Ltd.) and cured by irradiating with ultraviolet rays to form a colored layer. The drawing speed is the same as in Comparative Example 1. Moreover, the optical fiber tape was manufactured similarly to Example 1, and the test similar to Example 1 was done about the colored optical fiber strand and the optical fiber tape.
(Comparative Example 3)

As Comparative Example 3, a colored optical fiber was manufactured as follows. First, the outer circumference of a silica glass fiber having a diameter of 125 ± 1 μm is coated with a urethane acrylate ultraviolet curable resin D having a Young's modulus of 600 ± 100 MPa and an adhesive strength of 25 ± 5 g / cm width with a thickness of 10 μm, and then irradiated with ultraviolet rays. After the first ultraviolet curable resin layer is formed by irradiating with an ultraviolet ray by an apparatus (6 kW × 1 lamp) to form a first ultraviolet curable resin layer, a urethane acrylate ultraviolet curable resin B having a Young's modulus of 1.0 ± 0.2 MPa is 22 μm. And a second ultraviolet curable resin layer is formed by irradiating with an ultraviolet ray by an ultraviolet irradiation device (6 kW × 1 lamp) and curing. Next, a urethane acrylate ultraviolet curable resin C having a Young's modulus of 800 ± 100 MPa is coated with a thickness of 25 μm, and cured by irradiating with an ultraviolet ray by an ultraviolet irradiation device (6 kW × 4 lamps) to form a third ultraviolet curable resin layer. The outer periphery of the third ultraviolet curable resin layer was coated with an ultraviolet curable colored ink (EM-3000 series: manufactured by Kansai Paint Co., Ltd.) and cured by irradiating with ultraviolet rays to form a colored layer. The drawing speed at this time is the same as in Comparative Example 1. Moreover, the optical fiber tape was manufactured similarly to Example 1, and the test similar to Example 1 was done about the colored optical fiber strand and the optical fiber tape.
(Comparative Example 4)

  As a comparative example 4, a colored optical fiber was manufactured as follows. First, the outer circumference of a silica glass fiber having a diameter of 125 ± 1 μm is coated with a urethane acrylate-based ultraviolet curable resin G having a Young's modulus of 800 ± 100 MPa and an adhesive strength of 5 g / cm width or less with a thickness of 3 μm. (6 kW × 1 lamp) is irradiated with ultraviolet rays and cured to form a first ultraviolet curable resin layer, and then a urethane acrylate ultraviolet curable resin B having a Young's modulus of 1.0 ± 0.2 MPa is formed at a thickness of 32 μm. Coating is performed, and ultraviolet rays are irradiated and cured by an ultraviolet irradiation device (6 kW × 1 lamp) to form a second ultraviolet curable resin layer. Next, a urethane acrylate ultraviolet curable resin C having a Young's modulus of 800 ± 100 MPa is coated with a thickness of 25 μm, and is cured by irradiating with an ultraviolet ray by an ultraviolet irradiation device (6 kW × 4 lamps) to form a third ultraviolet curable resin layer. The outer periphery of the third ultraviolet curable resin layer was coated with an ultraviolet curable colored ink (EM-3000 series: manufactured by Kansai Paint Co., Ltd.) and cured by irradiating with ultraviolet rays to form a colored layer. The drawing speed at this time is the same as in Comparative Example 1. Moreover, the optical fiber tape was manufactured similarly to Example 1, and the test similar to Example 1 was done about the colored optical fiber strand and the optical fiber tape.

  The test results of Examples 1 to 3 and Comparative Examples 1 to 4 are shown in Table 1.

  As can be seen from Table 1, the colored optical fiber wires 20 of Examples 1 to 3 are superior to those of Comparative Examples 1 to 4 for any test item. In particular, it can be seen that in the colored optical fiber wires 20 of Examples 1 to 3, the increase in loss after connection is small, and the characteristic change during connection is small. Also, in the optical fiber tapes 30 of Examples 1 to 3, the superiority of the 60 ° C. hot water test, the temperature characteristics, and the torsion test is significant as compared with Comparative Examples 1 to 4.

It is sectional drawing which shows the optical fiber strand which concerns on one embodiment of this invention. It is a figure which shows the sample for a measurement of the glass adhesive force of the ultraviolet curable resin used for the optical fiber which concerns on embodiment of this invention, and the outline of a measurement. It is sectional drawing which shows the colored optical fiber wire which concerns on Examples 1-3. It is sectional drawing which shows the optical fiber tape which concerns on Examples 1-3.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical fiber strand 2 Quartz glass fiber 3 1st ultraviolet curable resin layer 4 2nd ultraviolet curable resin layer 5 3rd ultraviolet curable resin layer 10 Sample 11 UV curable resin 12a, 12b Quartz slide glass 13 Slit 20 Colored optical fiber 22 Silica glass fiber 23 First UV curable resin layer 24 Second UV curable resin layer 25 Third UV curable resin layer 26 Colored layer 30 Optical fiber tape 31 Covering layer

Claims (4)

Quartz glass fiber,
A first ultraviolet curable resin layer formed on the outer periphery of the silica glass fiber, having a Young's modulus of 50 MPa or more, a glass adhesion of 20 to 50 g / cm width, and a layer thickness of 1 to 3 μm;
And a second ultraviolet curable resin layer formed on an outer periphery of the first ultraviolet curable resin layer and having a Young's modulus lower than that of the first ultraviolet curable resin. .   The optical fiber strand according to claim 1, further comprising a third ultraviolet curable resin layer on an outer periphery of the second ultraviolet curable resin layer.   3. The optical fiber according to claim 1, wherein the ultraviolet curable resin layer is a urethane acrylate ultraviolet curable resin.   A quartz glass fiber, a first ultraviolet curable resin layer formed on an outer periphery of the quartz glass fiber, having a Young's modulus of 50 MPa or more, a glass adhesion force of 20 to 50 g / cm width, and a layer thickness of 1 to 3 μm; A plurality of optical fiber strands formed in parallel on the outer periphery of the first UV curable resin layer and having a second UV curable resin layer having a Young's modulus lower than that of the first UV curable resin. An optical fiber tape that is lined up and covered with a coating layer made of an ultraviolet curable resin.

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