JPS59202404A - Optical fiber core and unit - Google Patents

Abstract

PURPOSE:To obtain an optical fiber core which has superior lateral pressure resistance, elongation relief effect, and watertight structure and is usable for a submarine cable, etc., by providing glass fiber with a hard, a gel, and a protection coating film in order from the inside. CONSTITUTION:The optical fiber core 10 is formed by providing the glass fiber 1 with the hard coating layer 7, gel coating layer 8, and protection coating layer 9 in order from the inside. The hard coating layer 7 of the core 10 has a >=10kg/mm.<2> Young's modulus, and a screening test is taken with an about 2kg load in the stage where the optical fiber 1 is coated with the layer 7. The layer 8 operates as a buffer layer, so the lateral pressure resistance is excellent. The Young's modulus is therefore smaller than that of conventional Si rubber, etc., by 1-2 figures. The fiber 1 having the layer 7 is movable in the layer 8, so the elongation relief effect of the core 10 is superior. The layer 9 protects the fiber and also eliminates the difficulty in handling originating from the too soft layer 8.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to an optical fiber (+4) structure and an optical fiber unit in which a plurality of the optical fibers are assembled.

[Prior art]

FIG. 1 shows a conventional optical fiber core with a solid structure.

As shown in FIG. 1, conventional optical fiber cores include an optical fiber 1, a protective primary coating 2, a binding layer 3 that relieves stress on the optical fiber 1, and a layer 3 that eases handling and reduces stress. It is composed of secondary vertebrates 4 that serve as a durable shell.

Table 1 shows general dimensions and materials of optical fibers not shown in FIG.

Table 1 Dimensions and material O1 (E: Young's modulus) The optical fiber core shown in FIG. 1 has excellent lateral pressure resistance.

Now, for optical fiber core wires, a screening test is always performed to ensure reliability. This screening test is a kind of screening test. For example, in FIG.
After installing 0.5 k17 to 2.0 k inline
This is a test in which a load of approximately 100 g is intentionally applied, and optical fibers that would break under that load are screened out.

For general optical cables, a screening test is performed at approximately 0.5 kg, but optical fiber cores used in highly reliable cables such as submarine cables require high reliability. A load of approximately 2 kg is applied.

However, in the conventional example shown in FIG. 1, when a screening test was conducted under a load of about 2 kg after the secondary coating 2 was provided, as shown in Table 1 above, the secondary coating 2 was soft. - Problems such as peeling, deformation and eccentricity of the second coating 2 occur.

That is, it has the disadvantage that it is not possible to perform a screening test with a load of approximately 2 kg, which is an essential condition for highly reliable cables such as submarine cables.

In addition, in the case where an optical fiber unit is constructed by aggregating a plurality of the optical fiber cores, each optical fiber core has a buffer layer 3, so that the lateral pressure resistance is low. Are better.

However, when used in submarine cables, it is necessary to have excellent lateral pressure resistance and at the same time tensile resistance, that is, a large elongation relaxation effect. Unfortunately, this problem υ・The relaxation effect is lacking.

[Objective of the Invention J] In view of the above-mentioned problems, an object of the present invention is to provide an optical fiber core wire with improved screening resistance and excellent lateral pressure resistance, and to provide an optical fiber core wire with improved resistance to elongation by using the core wire. An object of the present invention is to provide an optical fiber unit that is highly effective and has excellent watertightness.

[Structure of the invention]

In order to achieve the above object, the optical fiber core wire of the present invention is characterized in that a glass fiber is provided with a hard coating layer, a gel coating layer, and a protective coating layer in order from the inside. In the fiber unit, a plurality of optical fiber cores made of a protective coating layer of the optical fiber core wire or a hard acrylate resin are gathered around a high-tension wire, and the optical fiber core wires are formed between the optical fiber core wires and between the optical fiber core wires. A soft acrylate resin is filled between and around the high tension wires, and the area around them is filled with a soft acrylate resin.

[Embodiments of the invention]

FIG. 2 shows an embodiment of the optical fiber core according to the present invention.

FIG. 2 is a cross-sectional view of the optical fiber core wire 10.
A K hard coating layer 7, a gel coating layer 8, and a protective coating layer 9 are provided.

In the optical fiber core 10, the hard layer 7 has a Young's modulus of approximately 10 k! ? / m4 or more of hard tillage,
Optical fiber] EWeighs approximately 2 kg with this coating applied.
A screening test is conducted with a load of . However, as mentioned above, since the hardness of the coating layer is sufficient, the enveloping layer does not peel off, deform, or become eccentric during the screening test.

The gel-like coating layer 8 coated after the screening test acts as a buffer layer and has good lateral pressure resistance. In addition, its Young's modulus is one to two orders of magnitude lower than that of silicone rubber or urethane acrylate, which are conventionally used as buffer layers.

Therefore, the optical fiber I having the hard coating 7 is movable within this gel-like coating layer 8, which indicates that the optical fiber core 1o of the present invention also has an excellent elongation relaxation effect.

Furthermore, the protective abrasion layer 9 provided on the gel-like breakable layer 8 protects the optical fiber as well as the handling stress due to the gel-like covering layer 8, that is, the gel-like covering layer protects the optical fiber. The problem that the gel layer 8 is too soft and difficult to handle can be solved by chewing the gel-like stepped layer 8.

As described above, the optical fiber core wire 0 of the present invention has improved screening resistance, and even though the second coating is hard, the outer periphery is an extremely soft gel-like covering layer, so it has excellent screening resistance. Good lateral pressure properties. Furthermore, the stretching and relaxation effects are also excellent.

Next, an embodiment will be described in more detail using the schematic diagram of the optical fiber manufacturing apparatus of the present invention shown in FIG.

A quartz glass optical fiber drawn to an outer diameter of 0.125 mm using a normal drawing device is coated with epoxy acrylate having a Young's modulus of about 40/miA after curing, and cured with an ultraviolet lamp to form a hard coating. After forming a layer, one in-line screening test is performed to form an optical fiber strand 11.

This optical fiber wire 11 is sealed by a supply 12 shown in FIG. 3, and guided to an applicator 14 via a reel 13. Each of the applicators 14 has a Young's modulus of 0 after curing.
．． 001, 9/m++4.11 okg/T+TA ultraviolet curable silicone gel and epoxy acrylate were simultaneously applied to outer diameters of 0.5 mm and 0.7 mm, cured with ultraviolet lamp 15, and reel 1.
6 and then pulled by a take-up 1 17 and wound up by a winder 18.

Here, the dimensions of this embodiment described above, A=J 1, are summarized in Table 2.

Table 2 Dimensions and interest rate (E knee?:/G rate) Not shown in Table 2, there are 80 gel-like employee layers in 5, or the conventional loose f
The reason why layers i1 and 3 are thicker is that, as mentioned in +, L, and 1ifJ, this layer not only acts as a buffer layer against lateral pressure, but also plays a role in producing an elongation relaxation effect.

Now, a plurality of optical fiber core wires 10 made in this way are gathered around the high tension wire, and the above-mentioned light is applied between the optical fiber core wires, between the optical fiber core wire and the high tension wire, and around them. filled with a soft acrylate resin similar to the protective coating layer 0 of the fiber core wire 10 and opposite to the protective coating layer 9;
Coating to make an optical fiber unit.

Next, this will be specifically explained using examples.

FIG. 4 is a sectional view of an embodiment of the optical fiber unit. As shown in FIG. 4, an optical fiber core 10 according to the present invention is placed around a stainless steel wire 9 having an outer diameter of 0.7 mm.
Let's gather together with our hearts together.

After that, the Young's modulus after curing was 0.3 k! ? /
Urethane acrylate having an rni of about 4 is filled thoroughly into the gaps between the core wires and between the core wires 10 and the stainless steel wires 19, and their surroundings are also covered as shown in FIG. 4 to form a protective layer 20. After the filling and coating, the optical fiber unit 21 is cured using an ultraviolet lamp to form an integrated optical fiber unit 21 having a watertight structure with an outer diameter of 2.3 mm.

As shown in FIG. 2, the optical fiber unit 21 formed in this manner has an optical fiber core 1o o) The buffer layer is made of a gel-like covering layer, so it is different from the conventional optical fiber core shown in FIG. Unlike the conventional fiber unit constructed with 7
), the optical fiber unit 21 of the present investigation is )IJj,
It is also okay to use a pull V-hole, which is subjected to quite high tension during installation.

Furthermore, the optical fiber core i ] 0 has a 11φ coating layer.)
Since the protective layer 20 of the optical fiber unit 21 and the protective layer 20 of the optical fiber unit 21 are made of the same type of acrylate resin, the adhesion between the two is good. In addition, the acrylate resin (4) has good adhesion to the steel wire, so the optical fiber unit 2 has an excellent watertight structure as a whole.

In addition, since the protective colored layer ( ) of the optical fiber core wire 10 and the maintenance layer 20 of the optical fiber unit 21 have good adhesion or have a large difference in hardness, when stripping the terminal 1d, the protective layer 20 It can be separated by tearing it apart.

〔Effect of the invention〕

As described above, the optical fiber core wire of the present invention does not cause peeling, deformation, or eccentricity of the stepped layer even in high-load screening tests, has excellent lateral pressure resistance, and has excellent elongation relaxation. It also has the advantage of being effective.

In other words, it is not simply a hard coating to improve screening resistance, but has a structure that takes into account the various conditions of VC used in harsh environments such as submarine cables. Therefore, it is an extremely reliable optical fiber.

Next, the optical fiber unit of the present invention has the above-mentioned features,
Because it is composed of optical fiber core wire with advantages,
The advantage of the optical fiber core wire is that it has excellent lateral pressure resistance,
In addition to retaining the advantage of having an elongation-reducing effect, it also has an excellent watertight structure. Therefore, high reliability can be guaranteed even when used under severe conditions such as submarine cables.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of a conventional optical fiber core, FIG. 2 is a sectional view of the optical fiber core of the present invention, and FIG. 3 is a schematic diagram showing the method of manufacturing the optical fiber core of the present invention. FIG. 4 is a sectional view of the optical fiber unit of the present invention. 1 optical fiber, 7 hard coating layer, 8 gel coating layer,
9 protective coating layer, 10 optical fiber core wire, 19 stainless steel wire, 20 protective layer, 21 optical fiber unit l-. Figure 1 Figure 2 Figure 3 Figure 1

Claims (1)

[Claims] (+1) An optical fiber core wire characterized in that a glass fiber is provided with a hard coating layer, a gel coating layer, and a protective coating layer in order from the inside. (2) A glass fiber is provided with a hard coating layer, a gel coating layer, and a protective coating layer in order from the inside. A plurality of optical fiber cores provided with a protective coating layer consisting of a hard coating layer, a gel-like covering layer, and a hard acrylate resin are assembled around a high-tension wire, and the optical fiber core wires are separated between the optical fiber core wires and between the optical fiber core wires. An optical fiber unit characterized by filling and coating a soft acrylate resin between and around the high tension wires.