JPH04162005A - Optical fiber colored core wire and its manufacturing method - Google Patents

Abstract

PURPOSE:To prevent a secondary covering layer as a colored layer from being removed in association with removal of an omnibus covering layer by preparing a reactive diluting agent having a functional radical, which makes radical reaction quickly on an energy line of ultraviolet rays, etc., and an ion reactive functional radical with a low reaction speed, which reacts under effect of heat, etc., allowing a primary covering layer and/or colored layer to contain this reactive diluting agent, and thereby increasing the strength of tight contacting. CONSTITUTION:Each colored core 4 is formed by putting a primary covering layer 2 on over the periphery of an optical fiber, and further thereon a colored layer 3 is applied, wherein the covering materials shall appear in different combinations. This is subjected to 80 deg.C heat treatment for 10hr. Then four such colored cores 4 are placed in line, and an omnibus covering 5 is applied to their periphery. Thus a tape-form optical fiber is accomplished.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a coated optical fiber used for optical communications and the like, and particularly to a coated optical fiber with a colored layer.

[Conventional technology]

In optical fibers used for optical communication, it is said that it is preferable not only to optical glass fibers and quartz-based glass fibers, but also to immediately apply a plastic coating (primary coating) to the outer periphery of the optical fibers after forming them into fibers. This is to prevent the strength of the fiber from decreasing due to scratches on the surface of the fiber that occur when the fiber is made into a fiber, or cracks that grow when the bare fiber is exposed to the air. Generally, thermosetting resins, ultraviolet curable resins (hereinafter referred to as ``UV resins''), radiation curable resins, etc. are used for such plastic layers, and in recent years UV resins have been particularly popular. It is being

Optical fiber using UV resin as the primary coating layer (UV
Resin-coated optical fiber) is produced by, for example, continuously applying UV resin to an optical fiber drawn in a drawing furnace using a coach inverter, and then curing the applied UV resin by irradiating it with ultraviolet rays. Manufactured. In addition, such UV resin-coated optical fibers are further coated with a secondary coating either singly or in combination to form an optical fiber core.As this secondary coating layer, for identification,
A colored layer may be coated onto a single UV resin-coated optical fiber, and this is called a colored line.

[Problem that the invention seeks to solve]

Usually, multiple colored core wires are laid out horizontally, and the outer one of them is
By not applying this blanket coating, a tape-shaped optical fiber core wire is obtained.

This tape-shaped optical fiber core is used when laying cables, etc.
When attempting to joint, it is necessary to remove the end coating layer at the end portion to expose the colored core wire. However, when removing the cover layer, it often happens that the colored layer is also removed together.

If the colored layer is removed at the same time, it becomes impossible to distinguish between the strands, which makes the jointing process very difficult and takes a long time.

[Means for solving problems]

The present invention provides a colored core wire of an optical fiber that allows easy joint work without the colored layer being removed together with the binding coating layer. It is.

That is, the present invention uses a reactive diluent that has a functional group that undergoes a rapid radical reaction with energy rays such as ultraviolet rays, and an ion-reactive functional group that reacts with a slower reaction rate than the functional group that reacts with the action of heat. A colored optical fiber core characterized by containing a coating layer, a colored layer, or both a primary coating layer and a colored layer, and further improved by heat treatment after curing with ultraviolet rays. The adhesion strength between the primary coating layer and the secondary coating layer is increased, and the secondary coating layer, which is a colored layer, is not removed together with the binding coating layer, simplifying the joint work. This is a method for manufacturing colored optical fibers that can be carried out in the following manner.

The reactive diluent used in the present invention is a functional group that undergoes an ionic reaction and has a high reaction rate due to the action of ultraviolet rays, etc., and a functional group that causes an ionic reaction due to the action of heat and has a reaction rate that is slower than that of the functional group. Examples of reactive diluents containing in one molecule include the following compounds.

H3 CR2 / \ In these compounds, the C 12-C portion undergoes a decal reaction due to the action of ultraviolet rays, etc., and undergoes an ionic reaction due to a reaction rate reaction, forming a functional group whose 1 reaction rate is slower than that of the functional group It is.

The method of using a combination of compounds having one type of each of these two types of functional groups is also effective, but the effect when using compounds such as ■ to ■ that have two types of functional groups in one molecule is particularly effective. ;This was remarkable.

In addition, in the present invention, the heat treatment performed after curing the primary coating layer and the secondary coating layer by ultraviolet irradiation is performed at a temperature of 60°C to 100°C.
Although it is preferable to carry out the treatment under normal conditions, effective results may also be obtained by leaving it for a few days at room temperature. Due to the action of
This reactive dilution is achieved by adding a reactive diluent that has in its molecules a functional group with a fast reaction rate and a functional group that undergoes an ionic reaction under the action of heat and has a reaction rate slower than the functional group. The agent acts as a binder between the primary coating layer and the colored layer, increasing the adhesion strength between the primary coating layer and the colored layer.

As a result, when removing the coating at the end portion at the time of noyointing, the colored layer is not removed at the same time.
Each core can be easily identified, so the knotting work can be carried out more efficiently.

〔Example〕

As shown in Figure 1, a colored optical fiber coated wire with a primary coating layer and then a colored layer provided on the outer periphery of the optical fiber was strung together with various coating materials, and colored coated wire A was prepared as shown in Table 1. - Colored core wires F were prepared and each of these was heat-treated at 80° C. for 10 hours.

Subsequently, four each of the colored core wires A to F were lined up horizontally, and as shown in FIG. 2, their outer peripheries were coated all at once to produce tape-shaped optical fiber cores.

Table 1 Various optical fiber colored core wires [Effects] Radical reactions occur due to the action of ultraviolet rays used in the present invention,
A reactive diluent that has in one molecule a functional group with a fast reaction rate and a functional group that is ionized by the action of heat and has a reaction rate slower than the functional group is not added to the primary coating layer or the colored layer. For the colored cores a to #iIf, which were created in the same manner as the colored cores A to F, except for this point, lay out four of each of them horizontally, and lay them out as shown in Figure 2. When we created a tape-shaped optical fiber by applying a coating to the outer periphery and removing the coating at the end, the colored layer was also removed, making it difficult to separate each core. Ta.

However, in the case of the tape-shaped optical fiber core using the colored cores A to F of the embodiments of the present invention, only the -bracket coating can be removed, and each core can be easily identified. Therefore, the efficiency of joint work was extremely high.

In addition, in the example, colored core wires A to colored core wires F are created,
After heat treatment at 80°C for 10 hours, a coating was applied to the outer periphery of each of the four colored cores to create tape-shaped optical fibers. However, colored cores A to #jF were created. hand,
Even if you leave it at room temperature for several days and then apply a cover,
- The colored layer was not removed together with the coating when the coating was removed.

It was also confirmed that Compound (1), Compound (2), Compound (2), and Compound (2) had the same effects as Compound (2) and Compound (2).

[Brief explanation of the drawings] Figure 1 is a cross-sectional view of a colored optical fiber, and Figure 2 is a cross-sectional view of a colored optical fiber.
FIG. 2 is a cross-sectional view of a tape-shaped optical fiber core. l: Optical fiber 2: Primary coating layer 3: Secondary coating layer (colored layer) 4: Optical fiber colored core 5 and bulk coating layer 6: Tape-shaped optical fiber core

Claims (4)

[Claims] (1) In colored optical fiber cores, which are formed by applying a primary coating layer and then a colored layer (secondary coating layer) to the outer periphery of the optical fiber, functional groups that rapidly react with radicals due to energy rays such as ultraviolet rays and heat, etc. A reaction diluent having in one molecule a functional group that undergoes an ionic reaction and whose reaction rate is slower than that of the functional group is added to the primary coating layer or the colored layer, or between the primary coating layer and the colored layer. A colored optical fiber characterized by the addition of (2) The reactive diluent described in claim 1 ▲ has a mathematical formula, chemical formula, table, etc. ▼ or ▲ has a mathematical formula, chemical formula, table, etc. ▼ [However, R_1, R_2, R_3, R_4, R_5 represents hydrogen, methyl group, ethyl group, allyl group, phenyl group, etc. Further, n indicates a repeating unit. ] A colored optical fiber core characterized by being a compound represented by (3) A colored optical fiber core characterized in that the reaction diluent according to claim 2 is glycidyl acrylate or glycidyl methacrylate. (4) A method for manufacturing a colored optical fiber, which comprises performing a heat treatment after forming the colored optical fiber according to claim 1.