JPH0632636A - Produciton of optical fiber coated with metal - Google Patents

Abstract

PURPOSE:To produce metal-coated optical fiber having a limited part of low strength. CONSTITUTION:In the production of a metal coated optical fiber by forming a coated film of metal on a carbon coated optical fiber 3a prepared by making a coated film of carbon on an optical fiber 3, the carbon coated optical fiber 3a is coated with a resin to form an optical fiber 3b coated with the resin. Then a coated film of metal is formed while removing the coated resin of the optical fiber 3b coated with the resin.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a metal-coated optical fiber.

[0002]

2. Description of the Related Art When an optical fiber is laid at a high temperature for information transmission, a metal coating is formed on an ordinary silica glass optical fiber as an optical fiber to improve heat resistance and mechanical strength. Often used. A metal coating may be provided for the purpose of improving the strength of the optical fiber. As a method for manufacturing a metal-coated optical fiber having excellent heat resistance of this type, a carbon-coated optical fiber is manufactured,
A method of performing electroless plating, electrolytic plating, or two-layer plating of electroless and electrolytic plating on the metal has been already proposed (see Japanese Patent Application No. 1-221832). In this method, a carbon-coated optical fiber was first drawn and wound without resin coating, and then a metal coating layer was plated on the carbon-coated optical fiber in a separate step.

[0003]

However, in the above method, since the bare carbon-coated optical fiber always passes through the capstan, dancer roller, etc. during drawing, many scratches are formed on the carbon layer surface of the optical fiber, and There is a problem that the strength of the fiber is reduced, and thus the strength of the finally obtained metal-coated optical fiber is also reduced.

[0004]

The present invention provides a method for producing a metal-coated optical fiber which solves the above problems, in which a carbon coating is provided on the optical fiber to form a metal coating on the carbon-coated optical fiber. In the method for producing a metal-coated optical fiber, a step of forming a resin-coated optical fiber by applying a resin coating to a carbon-coated optical fiber, and forming a metal coating while removing the resin coating of the resin-coated optical fiber It is characterized by having a step of

[0005]

As described above, first, a carbon-coated optical fiber coated with resin is manufactured by a known method. Then, when the metal coating is formed on the carbon-coated optical fiber while removing the resin coating, it becomes unnecessary to pass the optical fiber through the caster or the roller with the carbon coating exposed.
Therefore, it is possible to obtain a metal-coated optical fiber with few low-strength portions without causing many scratches on the carbon layer of the optical fiber during the manufacturing process.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the embodiments shown in the drawings. FIG. 1 is a process explanatory diagram of an embodiment of a method for producing a metal-coated optical fiber according to the present invention.
1A shows a drawing process, and FIG. 1B shows a metal coating process. In FIG. 1A, 1 is a preform (base material for optical fiber), 2 is a drawing furnace, 3 is an optical fiber, 4 is an optical fiber outer diameter measuring instrument, 5 is a thermal CVD reaction container, 6 is a heater, and 7 Is a source gas introduction port, 8 is an exhaust port, 9 is a coating die, 10 is a resin curing furnace, and 11 is a bobbin. In FIG. 1B, 12 is a core feeding machine, 13 is a resin removing device, and 14 is a resin removing device.
Is a cleaning device, 15 is a plating device, and 16 is a take-up device. The process is as follows. That is, 1) First, a hydrocarbon gas such as acetylene introduced from the raw material gas introduction port 7 is heated by the thermal CV on the optical fiber 3 formed by drawing the preform 1 by the drawing furnace 2.
The carbon coating optical fiber 3a is formed by thermally decomposing in the D reaction vessel 5 to synthesize a carbon film having a thickness of about 400Å. 2) Next, an acrylic resin is coated on the carbon coated optical fiber 3a with a coating die 9, and this is cured through a resin curing furnace 10 to form a resin coated optical fiber 3b, which is wound on a bobbin 11. 3) Next, the bobbin 11 is mounted on the core feeder 12, and the resin-coated optical fiber 3b is sent from the core feeder 12 to the resin removing device 13 to remove the resin coating. 4) The carbon-coated optical fiber 3a coming out of the resin removing device 13 is passed through a cleaning device 14 provided if necessary, and then plated with nickel having a thickness of about 5 μm by a plating device 15. The resin removing device 13 is composed of a bath of an organic solvent such as toluene or trichlene heated to 60 to 90 ° C., and an ultrasonic vibrator is attached to this bath. When the resin coating optical fiber 3b is passed through the resin removing device 13 for about 10 minutes, the coating resin can be cleanly peeled from the carbon layer. When the temperature of the organic solvent was room temperature, it took 30 minutes or more to remove the resin. The following three types were manufactured as samples. That is, Sample 1: The resin-coated optical fiber 3b was passed through the resin removing device 13 in about 10 minutes. Specimen 2: A resin surface was scratched with a cutter in advance, and then the resin-coated optical fiber 3b was passed through the resin removing device 13 for about 5 minutes. In this case, the organic solvent quickly penetrates into the resin, and the resin on the carbon surface layer is easily peeled off and completely removed within 5 minutes. Sample 3: As a comparative example, a drawn carbon-coated optical fiber (without resin coating) was once wound around the bobbin 11 and then sent directly from the core feeder 12 to the cleaning device 14, the plating device 15, and the take-up device 16. . The results of examining the relationship between the breaking strength and the breaking probability of the above sample are shown in FIG. As can be seen from FIG. 2, Samples 1 and 2 had few low-strength parts, and showed a good strength distribution.
In particular, Sample 2 in which the resin was easily peeled off showed a better strength distribution. On the other hand, it can be seen that Sample 3 has a large number of low-strength portions, and the carbon-coated optical fiber is damaged during the manufacturing process.

[0007]

As described above, according to the present invention, in the method for producing a metal-coated optical fiber in which a metal coating is formed on a carbon-coated optical fiber in which a carbon coating is provided on the optical fiber, Since it has a step of forming a resin-coated optical fiber by applying a resin coating and a step of forming a metal coating while removing the resin coating of the resin-coated optical fiber, scratching the carbon-coated optical fiber Since the metal coating can be performed without using the metal coating, there is an excellent effect that it is possible to manufacture a metal coated optical fiber having a low strength portion.

[Brief description of drawings]

1A and 1B are process explanatory views of an embodiment of a method for producing a metal-coated optical fiber according to the present invention.

FIG. 2 is a diagram showing the relationship between the breaking strength and the breaking probability of the metal-coated optical fiber manufactured in the above process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Preform 2 Drawing furnace 3 Optical fiber 4 Optical fiber outer diameter measuring instrument 5 Thermal CVD reaction vessel 6 Heater 7 Raw material gas introduction port 8 Exhaust port 9 Coating die 10 Resin curing furnace 11 Bobbin 12 Core feeder 13 Resin removing device 14 Cleaning Equipment 15 Plating equipment 16 Collection equipment

Front page continued (72) Inventor Yoshito Uda 2-5 Kusunekita-machi, Neyagawa-shi, Osaka Kyowaden Line Co., Ltd. Within

Claims (1)

[Claims] 1. A method for producing a metal-coated optical fiber in which a metal coating is formed on a carbon-coated optical fiber in which a carbon coating is provided on an optical fiber. And a step of forming a metal coating while removing the resin coating of the resin-coated optical fiber, the method for producing a metal-coated optical fiber.