JPH11149020A - Optical fiber cord - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical fiber cord which has bending rigidity suitable for handling, is less buckled by bending and is formed to a smaller diameter. SOLUTION: A reinforcing layer 4 having a thickness of 200 to 300 μm is formed on an optical fiber 1 by impregnating a tension member with a UV curing type resin having a Young's modulus of 0.1 to 20 kg/mm<2> . An over-coating layer 5 of a thickness 100 to 200 μm consisting of the UV curing type resin having the Young's modulus of 40 to 200 kg/mm<2> is formed on this reinforcing layer 4.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber cord used for connection between optical devices in a station.

[0002]

2. Description of the Related Art In recent years, diversification and increase of transmission information in long-distance optical communication and the like have led to an increase in intra-station optical wiring used between intra-station devices and the like.
There is a need for ultra-fine diameter optical fiber cords. FIG.
Shows an example of a conventional optical fiber cord, and this optical fiber cord has a loose type structure. In the figure, reference numeral 1 denotes an optical fiber.
A tension member 2 such as a glass fiber or an aramid fiber is provided as a tension member on the outer periphery of the optical fiber 1. On the outer periphery of the tension member 2, polyvinyl chloride,
A sheath 3 made of plastic such as polyethylene is provided. In this loose type structure, the strength member 2 remains fibrous and is not bonded to the optical fiber 1. The outer diameter of such an optical fiber cord is usually 1.7 to 2.0 mm.

FIG. 1 shows an example of an optical fiber cord called a tight structure in which a tensile member is integrated with a resin. In the figure, reference numeral 1 denotes an optical fiber. On the outer periphery of the optical fiber 1, a reinforcing layer 4 is formed by impregnating a glass fiber, an aramid fiber, or the like of a tensile strength material with an ultraviolet-curable resin and solidifying it. An overcoat layer 5 made of an ultraviolet curable resin is provided on the outer periphery of the reinforcing layer 4. In this tight structure, the strength member is integrated and adhered to the optical fiber 1. For this reason,
The outer diameter can be made smaller than that of the loose-type optical fiber cord. Therefore, since a small-diameter optical fiber cord is desired, it is changing from a loose type structure to a tight type structure.

[0004]

However, in an optical fiber cord having a tight structure, the bending strength of the optical fiber cord is increased by integrating the strength member with an ultraviolet curable resin, and the loose type structure having the same outer diameter is used. Buckling due to bending is more likely to occur than in an optical fiber cord.
Usually, the optical fiber cord is handled by a human hand at the time of use, so buckling due to bending is a serious problem.
The buckling problem can be improved to some extent by providing a thick overcoat layer. However, when the overcoat layer is made thicker, the bending rigidity of the optical fiber cord is further increased, which leads to deterioration in handling, making it difficult to compactly store the optical fiber cord and making it difficult to reduce the diameter of the optical fiber cord. Therefore, the demand for high-density optical wiring in the office cannot be satisfied.

The present invention has been made in view of the above circumstances, and has as its object to provide an optical fiber cord which has bending rigidity suitable for handling, has no buckling due to bending, and has a reduced diameter. I do.

[0006]

The object of the present invention is to provide a reinforcing layer having a thickness of 200 to 300 μm formed by impregnating a tensile strength member with a resin having a Young's modulus of 0.1 to 20 kg / mm ² on an optical fiber. The problem is solved by an optical fiber cord characterized in that an overcoat layer made of a resin having a Young's modulus of 40 to 200 kg / mm ^{2 and having} a thickness of 100 to 200 μm is provided on the reinforcing layer.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to FIG. The optical fiber cord of the present invention differs from the conventional tight-structured optical fiber cord shown in FIG. 1 in that a tensile strength member is impregnated with a UV-curable resin having a Young's modulus of 0.1 to 20 kg / mm ^2. A reinforcing layer 4 having a thickness of 200 to 300 μm is provided, and a Young's modulus 40 to 20
Thickness 100 ~ ^{20 made} of UV-curable resin of 0kg / mm2
That is, an overcoat layer 5 of 0 μm was provided. In a conventional tight-structure optical fiber cord, the reinforcing layer 4
Had high bending stiffness and tended to buckle. To improve this, the overcoat layer 5 was provided thicker, but the bending rigidity was further increased, and as a result, the outer diameter of the optical fiber cord was increased, and it was difficult to reduce the diameter. In the optical fiber cord of the present invention, the use of the above-described UV-curable resin having a low Young's modulus for the reinforcing layer 4 makes the reinforcing layer 4 low in bending rigidity and hardly causes buckling. For this reason, unlike the conventional tight-structure optical fiber cord, it is not necessary to make the overcoat layer 5 thick to prevent the reinforcing layer 4 from being buckled. In this figure, the Young's modulus and the thickness of the ultraviolet curable resin of the layer 5 were adjusted. Therefore, the diameter of the optical fiber cord can be reduced.

As the optical fiber 1, a generally used quartz glass fiber bare wire having a diameter of about 125 μm coated with an ultraviolet curable resin or the like is used.
The diameter of the optical fiber 1 is about 250 μm. Examples of the tension member used for the tensile strength member of the reinforcing layer 4 include glass fiber and aramid fiber. The UV-curable resin impregnated in the tensile strength member of the reinforcing layer 4 preferably has a Young's modulus after curing of 0.1 to 20 kg / mm ² . Because it is less than 0.1 kg / mm ² strength and curing of the reinforcing layer 4 is lowered, the strength of the optical fiber cord is also inconvenient becomes possible to decrease, during handling of the optical fiber cord exceeds 20 kg / mm ² This causes inconvenience because buckling occurs. The thickness of the reinforcing layer 4 is 200 to 300 μm
It is desirable to set to about. If the thickness is less than 200 μm, the effect of the tensile strength member on the optical fiber 1 becomes large, which is inconvenient.
Must be reduced, and sufficient rigidity cannot be obtained, which is inconvenient.

The UV-curable resin used for the overcoat layer 5 has a Young's modulus after curing of 40 to 200 kg.
/ mm ² is desirable. Is less than 40 kg / mm ^2, in order to flexural rigidity of the optical fiber cord is reduced, it is necessary to increase the thickness of the reinforcing layer 4 becomes a disadvantage since become impossible diameter of the optical fiber cord, exceeding 200 kg / mm ² In a low-temperature environment, the ultraviolet-curable resin of the overcoat layer 5 shrinks, and the side pressure causes microbends in the optical fiber cord, thereby increasing transmission loss, which is inconvenient. The thickness of the overcoat layer 5 is 100
It is desirable to set it to about 200 μm. If it is less than 100 μm, sufficient rigidity cannot be obtained, which is inconvenient.
If it exceeds 0 μm, handling becomes difficult, which is inconvenient.

The production of the optical fiber cord of the present invention can be performed, for example, by the following method. First, around the optical fiber 1, a glass fiber serving as a strength member,
A plurality of strands such as aramid fibers are longitudinally added, and the strands are fed to an application die for applying an ultraviolet-curable resin, and then sent to an ultraviolet irradiation device to cure the ultraviolet-curable resin to form a reinforcing layer 4. Next, this is sent to an application die for applying an ultraviolet-curable resin, and is similarly irradiated with ultraviolet rays to be cured to form an overcoat layer 5. Since the optical fiber cord of the present invention comprises the above-described optical fiber 1, the reinforcing layer 4, and the overcoat layer 5, the outer diameter is about 0.5 to 0.9 mm. The resin used for the optical fiber cord of the present invention is preferably an ultraviolet curable resin from the viewpoint of manufacturing. However, even if another thermosetting resin such as an epoxy resin is used, there is no particular problem in characteristics.

[0011]

EXAMPLES Specific examples of the present invention will be described below. FIG.
An optical fiber cord having the structure shown in FIG. At this time, various types of Young's modulus as shown in Table 1 were used as the ultraviolet curable resin constituting the reinforcing layer 4 and the overcoat layer 5. Glass fiber is used for the tensile member, the thickness of the reinforcing layer 4 is 250 μm, and the thickness of the overcoat layer 5 is 100 μm.
m. The buckling characteristics of the obtained optical fiber cord were evaluated. The buckling characteristics were evaluated as x when the bending was performed with a bending radius of 10 mm, and as を when not bending. Table 1 shows the results.

[0012]

[Table 1]

[0013]

As described above, the optical fiber cord of the present invention has a thickness of 200 to 200 kg / mm ^{2 in} which a tensile strength member is impregnated with a resin having a Young's modulus of 0.1 to 20 kg / mm ² on an optical fiber.
A reinforcing layer of 300 μm is provided, and a Young's modulus of 4
0-200kg / mm ² resin thickness 100-200μ
m overcoat layer is provided. Therefore, it is possible to provide an optical fiber cord which has bending rigidity suitable for handling, does not cause buckling due to bending, and has a reduced diameter. Therefore, it can be used for a single-core cord used for connection between optical devices in a station, a cord for an intra-office cable, a cord for a distribution cable, and the like, and can cope with a high-density optical fiber cord in the office.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an example of an optical fiber cord having a tight structure.

FIG. 2 is a sectional view showing an example of an optical fiber cord having a loose type structure.

[Explanation of symbols]

 DESCRIPTION OF REFERENCE NUMERALS 1: optical fiber, 2: strength member, 3: sheath 4: reinforcement layer, 5: overcoat layer

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Takeshi Shimichi, 1440, Mukurosaki, Sakura City, Chiba Prefecture Inside Fujikura Sakura Plant (72) Inventor Keiji Ohashi, 1440, Misaki, Sakura City, Chiba Prefecture Inside Fujikura Sakura Plant, Inc. (72) Inventor Masao Tatekura 3-19-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo Nippon Telegraph and Telephone Co., Ltd. In company

Claims (1)

[Claims] 1. Young's strength member on optical fiber
Rate 0.1-20kg / mm ^TwoThickness of 200 impregnated with resin
A reinforcing layer of about 300 μm is provided, and a Young's modulus
40-200kg / mm^Two100-200 thickness of resin
An optical filter characterized by providing a μm overcoat layer.
Fiber code.