JPH11242142A - Optical fiber coloring code - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent intrusion of light through side faces and to obtain good stripping property by forming an achromatic color resin layer as a primary coating layer and forming a chromatic color layer as a secondary coating layer. SOLUTION: A primary coating layer 2 and further, a secondary coating layer 3 are formed around an optical fiber 1 to form an optical fiber color code. In this method, the primary coating layer 2 is an achromatic color layer, while the secondary coating layer 3 is a chromatic color layer. A pigment or dye such as titanium oxide and carbon black is added to the resin of the primary coating layer 2 to make the coating film achromatic. It is preferable to add carbon black by >=0.1% so as to prevent intrusion of light through the side face. A pigment or dye is added to the resin of the secondary coating layer to make the layer chromatic, and the chroma is preferably controlled to >=4.0 to distinguish from electric wire code by colors. In this method, it is effective to control the thickness ratio (a/b) of the primary coating layer 2 (a) to the secondary coating layer 3 (b) to 0.1 to 0.50, preferably 0.15 to 0.35.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber coloring cord excellent in preventing light from entering from the side.

[0002]

2. Description of the Related Art Generally, an optical fiber is formed into a cord whose outer periphery is coated with an achromatic resin, and is used for communication purposes. If the optical fiber is coated with a chromatic resin to distinguish it from the electric wire code and used as an optical fiber colored code, light will enter from the side of the optical fiber code and the communication information will change, causing a malfunction of the equipment. was there.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an optical fiber colored cord excellent in preventing light from entering from the side.

[0004]

Means for Solving the Problems In order to solve such a problem, the present inventors have paid attention to multilayer optical fiber coating,
It has been found that by using an optical fiber coloring cord in which the primary coating layer is an achromatic colored resin layer and the secondary coating layer is a chromatic colored layer, light penetration from the side is excellent. That is, the present invention provides an optical fiber cord having a primary coating layer on the outer periphery of an optical fiber and a secondary coating layer on the outer periphery of the optical fiber. An optical fiber coloring code which is a colored resin layer. "

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. The optical fiber coloring cord of the present invention is shown with reference to FIGS.
FIGS. 1 and 2 are cross-sectional views of an example of an optical fiber coloring cord according to the present invention. Code is formed. In the optical fiber coloring cord of the present invention, it is important that the primary coating layer is an achromatic coloring layer and the secondary coating layer is a chromatic coloring layer, thereby being excellent in preventing light from entering from the side.

[0006] Pigments and dyes such as titanium oxide and carbon black are added to the resin of the primary coating layer to make it achromatic.
It is preferable to add 0.1% or more of carbon black in order to prevent light from entering from the side. Pigments and dyes are added to the resin of the secondary coating layer to make the resin a chromatic color, and the saturation is preferably 4.0 or more in order to distinguish the color from the electric wire cord.

Since an optical fiber cord cannot be directly connected to a communication device, a connector is connected to the optical fiber and used in consideration of operability when detaching from an ordinary device. At this time, since the coating layer on the end face of the cord is peeled off from the surface of the optical fiber using a wire stripper or the like, the optical fiber cord is required to be easily peelable.

The ease of peeling of the coating layer is determined by the ratio of the thickness (a) of the primary coating layer (a) to the thickness (b) of the secondary coating layer (a /
b) is important and its value must be between 0.10 and 0.50. If the ratio is less than 0.10, the primary coating layer remains on the cord when the coating of the optical fiber cord is peeled off, which is not preferable. On the other hand, if the ratio exceeds 0.50, the hue of the primary coating layer passes through the secondary coating layer and appears on the code surface, which is not preferable because the brightness of the secondary coating layer surface decreases. Therefore, the layer thickness ratio (a / b) is 0.10
It is effective that the ratio is 0.50, preferably 0.15 to 0.35.

The material of the optical fiber is not particularly limited, and may be a plastic optical fiber or a glass optical fiber. Further, the number of optical fiber core wires is not limited.

Examples of the resin of the coating layer include polyethylene, polypropylene, polyamide, polyester, polyolefin elastomer, polyamide elastomer, polyester elastomer, cross-linked polyethylene, cross-linked polypropylene and the like. 11, nylon 12 is preferred.

[0011]

EXAMPLE A nylon 12 coloring composition or a polyester elastomer coloring composition having the composition shown in Table 1 was applied to a 1000 μm diameter plastic optical fiber having a polymethyl methacrylate core and a perfluoroacrylate copolymer sheath. Coating was performed at a melting temperature of 220 ° C. so as to have a layer thickness ratio shown in Table 2 to produce an optical fiber colored cord. The coloring composition of the nylon 12 or the polyester elastomer was prepared by adding 0.5% of carbon black to a black color to make it achromatic, and a pigment having a color saturation of 6 to make it orange and a chromatic color. Used as resin.

Each of the optical fiber coloring cords is cut into a length of 4 m to form a quadruple winding. As shown in FIG. 3, one end of the optical fiber coloring cord is covered with a black cap so that light does not leak, and the other end is colored. Connected to optical power meter. Light was irradiated from a height of 200 mm above the optical fiber cord by a 50 W halogen lamp, and at this time, the amount of light passing through the cord surface and entering the optical fiber was measured. Table 2 shows the results of the light quantity, brightness, and strip property.

In Table 2, the brightness is visually determined based on the hue of the code surface, and the strip property is 1.2 m.
Using a wire stripper having a diameter of mφ, judgment was made based on whether or not the primary coating layer was completely peeled off from the optical fiber surface. As a criterion, the light amount, the brightness and the stripping property were evaluated in three stages: ：: very good, ：: good, and x: bad. The smaller the light amount, the better the brightness and the strippability, the better the optical fiber coloring code.

According to Table 2, the primary coating layer is achromatic, the secondary coating layer is chromatic, and the ratio (a / b) of the layer thickness is 0.10 to 0.10.
It can be seen that 0.50 is significantly better as an optical fiber colored cord.

[0015]

[Table 1]

[0016]

[Table 2]

[0017]

The optical fiber colored cord of the present invention is excellent in preventing light from entering from the side, and has a vivid chromatic color and good stripping properties.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing an example (single-core cord) of an optical fiber colored cord of the present invention.

FIG. 2 is a cross-sectional view showing another example (double-core cord) of the optical fiber colored cord of the present invention.

FIG. 3 is a schematic diagram of a light amount measuring method shown in the embodiment.

[Explanation of symbols]

 1: Optical fiber 2: Primary coating layer (achromatic color) 3: Secondary coating layer (chromatic color) 4: Optical fiber coloring code 5: 50W halogen lamp 6: Black cap 7: Optical power meter

Claims (5)

[Claims] 1. An optical fiber cord comprising a primary coating layer on the outer periphery of an optical fiber and a secondary coating layer on the outer periphery thereof, wherein the primary coating layer is achromatic and the secondary coating layer is chromatic. An optical fiber coloring code which is a resin layer colored. 2. The primary coating layer contains 0.1% of carbon black.
2. The optical fiber coloring cord according to claim 1, wherein the secondary coating layer is a chromatic coloring resin layer having a saturation of 4.0 or more. 3. The resin of the primary coating layer is polyamide,
3. The optical fiber coloring cord according to claim 1, wherein the resin of the secondary coating layer is at least one selected from polyethylene, polypropylene, polyamide, polyester, polyolefin elastomer, polyamide elastomer, polyester elastomer, crosslinked polyethylene, and crosslinked polypropylene. 4. The method according to claim 1, wherein the ratio (a / b) of the thickness (a) of the primary coating layer to the thickness (b) of the secondary coating layer is 0.10 to 0.50. Optical fiber coloring code as described. 5. The resin of the primary coating layer and the secondary coating layer is polyamide, and the ratio (a / b) of the thickness (a) of the primary coating layer to the thickness (b) of the secondary coating layer is 0. .10 to 0.50
The optical fiber coloring cord according to claim 1 or 2, wherein: