JP2001318285A - Optical fiber cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tape-type optical fiber cable that relieves stresseas and strains produced in tape type optical fibers by the improvement of the blocking resistance of the optical fibers, prevents movement of the optical fibers and reduces transmission loss. SOLUTION: In the tape-type optical fiber cable, containing a spacer with grooves cut in the outer surface and tape type optical fibers housed in the grooves, the surface of the optical fibers are coated with silicone powder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber cable, and more particularly, to improving the blocking resistance of a tape-type optical fiber core to reduce stress strain generated in the optical fiber and prevent the core from moving. The present invention relates to a tape type optical fiber cable which reduces transmission loss.

[0002]

2. Description of the Related Art In the field of optical communication, a plurality of optical fiber strands are arranged in parallel, and a tape type optical fiber having a structure in which the outer periphery thereof is collectively covered in a tape shape with an ultraviolet curable resin such as urethane acrylate resin. Fiber cores have been developed.

A tape type optical fiber cable having a structure in which such a tape type optical fiber core wire is housed in a spiral or SZ-shaped groove of a rod-shaped spacer can achieve high density and can be easily connected in tape units. It has excellent features such as that it can be performed.

[0004]

However, in such a tape type optical fiber core wire, since the ultraviolet curable resin has tackiness (adhesiveness) even after curing, and has a large friction coefficient,
Poor slipperiness on the surface, causing a blocking phenomenon (sticking of tape-type optical fiber cores) and turbulence during winding on a bobbin, causing uneven stress to be applied to the tape-type optical fiber core There was a problem. In addition, various problems have occurred such as difficulty in inserting a tape-type optical fiber core wire into a spiral groove of a rod-shaped spacer at the time of manufacturing an optical fiber cable. For this reason, at the time of optical fiber cable manufacturing, prior to winding on a bobbin, a lubricating lubricant (for example, powder such as talc, silicone oil, low molecular weight wax, etc.) is applied to the tape type optical fiber core. It has been practiced to apply directly to the surface to improve the surface slipperiness.

However, in a method of applying a powdery lubricant such as talc to the surface of a tape-type optical fiber core, a fine particle is formed in a short time before the tape-type optical fiber core is wound around a bobbin. Since it is difficult to apply the powder uniformly, the applied amount tends to be non-uniform, and microvents may be generated instead. In addition, the powder excessively adhered to the surface of the tape-type optical fiber is easily peeled and scattered in the atmosphere, which not only causes a failure of the equipment, but also may impair the health of workers. . Therefore, as a measure against scattering, attempts have been made to uniformly disperse these powders in a volatile solvent to prepare a dispersion (for example, to uniformly disperse talc in methanol, ethanol, or the like), and to apply the dispersion. Was. However, these powders have a high sedimentation speed, so that the dispersion liquid becomes non-uniform immediately (talc easily sediments due to the large difference between its specific gravity and the specific gravity of methanol, etc.), and the powder must be applied uniformly. Was difficult.

In the method of applying a liquid lubricant such as silicone oil, the silicone oil itself is
It has a slight volatility and diffuses into the resin coating layer, so that the amount of silicone oil remaining on the surface of the resin coating layer decreases over time, thus causing a blocking phenomenon. was there.

Further, in a tape-type optical fiber cable manufactured using the above-described tape-type optical fiber core, after the cable is laid, the tape-type optical fiber core moves due to the influence of vibration or the like, and as a result, the transmission occurs. There was an increase in losses.

Further, in the method of applying a low molecular weight wax, it is necessary to dissolve the wax in a highly volatile fluorocarbon-based solvent. At present, such a fluorocarbon-based solvent is regulated as one of the causes of environmental destruction. It is impossible to use.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to improve the blocking resistance of a tape-type optical fiber to reduce the stress strain generated in the optical fiber. Another object of the present invention is to provide a tape-type optical fiber cable that prevents the movement of a cord and reduces transmission loss.

[0010]

Means for Solving the Problems The present inventors have made intensive studies on the above-mentioned problems, and as a result, completed the present invention. That is, the present invention is as follows.

[0011] The tape type optical fiber cable of the present invention comprises:
It comprises a spacer having a groove on its outer surface, and a tape-type optical fiber core housed in the groove, and the surface of the tape-type optical fiber is coated with silicone powder. It is characterized by the following. Thereby, the above object is achieved.

In a preferred embodiment, the silicone powder has an average particle size of 10 μm or less.

[0013]

The operation of the present invention will be described below.

According to the present invention, a tape-type optical fiber cable includes a spacer having a groove on an outer surface thereof, and a tape-type optical fiber core housed in the groove. By coating the surface of the optical fiber with silicone powder, the surface slip property of the tape-type optical fiber is significantly improved, and as a result, the stress resistance generated in the optical fiber is improved by improving the blocking resistance. It can mitigate, prevent core movement and reduce transmission loss.

In the present invention, the anti-blocking property is determined when the laminated tape-type optical fiber core wire (for example, five 4-fiber tapes) housed in the groove of the spacer is taken out from the groove. The evaluation is made by visually checking whether or not the pieces are stuck to each other.

In the present invention, the movement of the cord is evaluated by using a tensile test. That is, under the conditions of a drawing speed of 50 mm / min, the core wire pulling force required to pull out the tape type optical fiber core wire from the tape type optical fiber cable was measured, and the core wire was moved by the obtained core wire pulling force. To evaluate.

In the present invention, the transmission loss is OTDR
(Optical Time Domain Refl
It is measured at a measurement wavelength of 1.55 μm using an electron microscope (Ectometer). The transmission loss is around 0.20 dB / km.

[0018]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the drawings. FIG. 1 is a sectional view of an embodiment of the tape-type optical fiber cable of the present invention.

As shown in FIG. 1, the tape type optical fiber cable 1 of the present embodiment comprises a tension member 2, a spacer 7 provided around the tension member 2, and a groove 5 provided on the outer surface of the spacer 7. , A tape-type optical fiber core wire 8 housed in the groove 5, a press-wrap tape 6 covering the outer surface of the spacer 7, a water-blocking layer 3 provided on the press-wrap tape 6, and a water-blocking layer 3. It consists of a sheath 4 provided above. Silicone powder (not shown) is applied to the surface of the tape-type optical fiber core 8.

The tape-type optical fiber cable 1 of this embodiment is different from the conventional one in structure, constituent material, manufacturing method or other aspects except that the surface of the tape-type optical fiber core 8 is coated with silicone powder. May be the same as the tape type optical fiber cable. Also groove 5
The inside may be filled with a waterproof grease or a waterproof compound for shielding the optical fiber from moisture and moisture. The waterproof layer 3 may be omitted in some cases, and the sheath 4 is directly placed on the holding tape 6. It may be provided. The thickness of the sheath 4 may be the same as the conventional one. For example, when the outer diameter of the tape-type optical fiber cable 1 is about 15 mm, it is about 1 to 2 mm.

FIG. 1 shows six grooves 5 and two tape-type optical fiber cores 8 accommodated in each groove 5.
However, in the tape-type optical fiber cable of the present invention, the number of grooves and the number of tape-type optical fibers accommodated in each groove are not limited to these numbers,
It can be appropriately selected according to the type of the desired tape type optical fiber cable.

The silicone powder used in the tape type optical fiber cable of the present invention is not particularly limited as long as it has lubricity. Preferably, the siloxane bond is represented by the general formula (RSiO _3/2 ) _n . Is a so-called cured polyorganosilsesquioxane powder having a three-dimensionally crosslinked structure. This silicone powder has excellent dispersibility in organic solvent dispersions, aqueous dispersions, and the like, and does not swell or dissolve in organic solvents and water. In addition, this silicone powder has excellent heat resistance as compared with an organic polymer, and has a 4 g
Even at 00 ° C., there is almost no change in weight and there is no thermal melting.

Examples of the substituent R in the general formula (RSiO _3/2 ) _n include an alkyl group (preferably having 1 carbon atom).
To 6 lower alkyl groups; for example, a methyl group, an ethyl group,
A propyl group), an aryl group (for example, a phenyl group) and the like, and a methyl group is more preferable.

The silicone powder is preferably 1
It has an average particle size of 0 μm or less, more preferably 5 μm or less, and most preferably 3 μm or less. Average particle size is 10μm
When the ratio exceeds 1, there is a problem that the coating state becomes non-uniform and that the coating is liable to be fooled.

The average particle size of the silicone powder in the present specification is a value measured by a laser diffraction method.

By applying such a silicone powder to the surface of the tape-type optical fiber, the surface slipperiness of the tape-type optical fiber is significantly improved,
As a result, stress strain generated in the optical fiber when the optical fiber cable is bent is relaxed, blocking resistance is improved,
An effect of preventing movement of the core wire and reducing transmission loss can be obtained.

Next, an example of a method for manufacturing the tape type optical fiber cable of the present invention will be described.

First, a plurality of (for example, two, four or eight) optical fiber strands are arranged in parallel, and their outer circumferences are collectively covered with an ultraviolet curing resin to form a tape type optical fiber core. Make it.

Next, the silicone powder is uniformly dispersed in a volatile solvent to prepare a dispersion. Examples of volatile solvents include lower alcohols (eg, methanol, ethanol, etc.), chloroform, ether, benzene,
Toluene, xylene, acetone, methyl ethyl ketone,
And carbon tetrachloride. The volatile solvent desirably evaporates quickly after the application of the dispersion and does not remain on the surface of the optical fiber ribbon. However, in the unlikely event that there is a possibility of swelling of the resin coating layer, it is preferable to use a lower alcohol that does not cause swelling,
Considering the effects on the human body, the use of ethanol is more preferable. When a lower alcohol is used, the specific gravity of the silicone powder is close to the specific gravity of methanol, ethanol or the like, so that it is difficult for the powder to settle. Therefore, the dispersion liquid does not become nonuniform and it is easy to apply it uniformly.

The dispersion prepared as described above is applied to the surface of the above-prepared optical fiber ribbon by, for example, a spraying method, and then the solvent is volatilized and removed. Thus, silicone powder is applied to the surface of the tape-type optical fiber core.

The amount of the silicone powder applied is preferably 10 g / m ^{2 to} 650 g / m ² , and most preferably 1 g / m ^{2 to} 650 g / m ²
It is a ^{00g / m 2 ~150g / m 2} . The application amount is 10
When the amount is less than g / m ² , the blocking phenomenon tends to occur. When the amount is more than 650 g / m ² , the excessively applied silicone powder is separated from the surface of the tape-type optical fiber core and scattered in the atmosphere. There is a problem that it becomes easier.

Next, the optical fiber ribbon coated with the silicone powder is wound around a bobbin. The tape-type optical fiber is accommodated in the groove of the spacer.

Finally, the outer surface of the spacer is sequentially covered with a press-wrap tape, a water-blocking layer, and a sheath to obtain a tape-type optical fiber cable of the present invention.

[0034]

EXAMPLES The present invention will be specifically described below with reference to examples.

(Embodiment 1) First, four single-mode optical fibers having an outer diameter of 250 μm are arranged in parallel, and the outer periphery thereof is collectively covered with an ultraviolet curable resin to obtain a width of 1.1 m.
A tape type optical fiber core wire having a thickness of 0.4 mm and a thickness of 0.4 mm was produced. Next, silicone powder (average particle size: 3 μm) was uniformly dispersed in ethanol to prepare a dispersion. This dispersion was coated with a silicone powder at an amount of 130 g / m2.
^In order to obtain 2, the surface of the above-prepared tape type optical fiber core was applied by a spraying method, and then ethanol was volatilized and removed. The optical fiber ribbon coated with the silicone powder was wound around a bobbin.

Next, the tape-type optical fiber core wires prepared as described above were inserted into each groove of a polyethylene spacer having an outer diameter of 9 mm having five grooves of a rectangular cross section having a width of 1.4 mm and a depth of 2.7 mm. Five are arranged, and a polyester holding tape is wound around the outer surface of the spacer. Thereafter, a 2.0 mm-thick aluminum-laminated polyethylene sheath was extruded (extrusion temperature: about 180 ° C.) to produce a tape-type optical fiber cable having a finished outer diameter of about 14 mm.

Comparative Example 1 A tape type optical fiber cable was produced in the same manner as in Example 1 except that silicone oil was applied to the surface of the tape type optical fiber core instead of silicone powder.

(Evaluation of Blocking Resistance) With respect to the tape-type optical fiber cables manufactured in Example 1 and Comparative Example 1, the blocking resistance was evaluated by measuring the laminated tape-type optical fiber core 5 accommodated in the groove of the spacer. When the sheet is taken out from the groove, it is visually observed whether or not the tape-type optical fibers are stuck to each other. Specifically, the tape-type optical fibers are not stuck to each other. The evaluation was performed by confirming whether the five laminated tapes could be separated without separating them with each other, or whether the tape-type optical fibers were stuck together and separated by hand. As a result, in the tape-type optical fiber cable manufactured in Example 1, the tape-type optical fiber core wire was not stuck, but in the tape-type optical fiber cable manufactured in Comparative Example 1, some stuck. Was.

From the above results, it can be seen that the tape-type optical fiber cable manufactured in Example 1 had better blocking resistance than the tape-type optical fiber cable manufactured in Comparative Example 1.

(Evaluation of Wire Movement) Using the test pieces of the tape-type optical fiber cable manufactured in Example 1 and Comparative Example 1, a pull-out test of the tape-type optical fiber cable was performed.
That is, using a tensile tester, a drawing speed of 50 mm /
Under the conditions of minutes, the core wire pulling force required to pull out the tape-type optical fiber core from the tape-type optical fiber cable was measured. As a result, the tape-type optical fiber cable manufactured in Example 1 required twice or more the core wire pulling force than the tape-type optical fiber cable manufactured in Comparative Example 1.

From the above results, it can be seen that the optical fiber cable manufactured in Example 1 is less likely to move the core than the optical fiber cable manufactured in Comparative Example 1.

(Evaluation of Transmission Loss) The maximum values of the transmission loss after winding the bobbin and after forming the cable of the tape-type optical fiber core wires manufactured in Example 1 and Comparative Example 1 were respectively measured by OTDR (Optical Time Domain).
n Reflectometer) at a measurement wavelength of 1.55 μm. As a result, the maximum value of the transmission loss of the tape-type optical fiber core wire manufactured in Example 1 was 0.20 d both after winding the bobbin and after forming the cable.
B / km or less. On the other hand, the maximum value of the transmission loss of the tape type optical fiber core wire manufactured in Comparative Example 1 was 0.2
They were 1 dB / km and 0.22 dB / km.

From the above results, it is understood that the transmission loss of the tape-type optical fiber core manufactured in Example 1 was smaller than that of the tape-type optical fiber core manufactured in Comparative Example 1.
Further, the tape-type optical fiber core wire manufactured in Example 1 had good loss temperature characteristics with little loss fluctuation.

[0044]

According to the present invention, there is provided a tape-type optical fiber that improves the blocking resistance of the optical fiber, thereby alleviating the stress distortion generated in the optical fiber, preventing the optical fiber from moving, and reducing the transmission loss. An optical fiber cable can be provided.

[Brief description of the drawings]

FIG. 1 is a sectional view of one embodiment of a tape type optical fiber cable according to the present invention.

[Description of Signs] 1 Tape type optical fiber cable 2 Tension member 3 Waterproof layer 4 Sheath 5 Strip provided on spacer surface 6 Holding tape 7 Spacer 8 Tape type optical fiber core

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Ryo Nishikawa 4-3 Ikejiri, Itami-shi, Hyogo Mitsubishi Electric Cable Industry Co., Ltd. Itami Works F-term (reference) 2H001 BB09 BB10 BB16 DD16 KK21

Claims (2)

[Claims] 1. A tape-type optical fiber cable comprising: a spacer having a groove on its outer surface; and a tape-type optical fiber core housed in the groove. A tape type optical fiber cable, wherein a silicone powder is applied to a surface of a fiber core. 2. The silicone powder has an average particle size of 10 μm.
2. The tape type optical fiber cable according to claim 1, wherein the length is not more than m.