JPH047483B2 - - Google Patents

Description

Detailed Description of the Invention (Industrial Application Field) The present invention relates to a method for manufacturing so-called tape-shaped optical fibers in which a plurality of optical transmission glass fibers (hereinafter referred to as optical fibers) having a primary coating are arranged. It is.

(Prior Art) Conventionally, tape-shaped optical fibers have been manufactured by two methods.

One method is to arrange coated optical fibers in a plane and use an extruder to coat them with thermoplastic resin such as nylon, polyethylene, or PVC (extrusion method). This is a method (adhesion method) in which a pressure-sensitive adhesive is applied to one side of a tape made of polyester or the like, and coated optical fibers arranged in a horizontal line are sandwiched and bonded between the two tapes.

(Problems to be Solved by the Invention) Both of these methods have the disadvantage of slow manufacturing speed. That is, in the former case, when extruded at high speed, there is a large residual strain in the longitudinal direction, which causes shrinkage after molding and bends the optical fiber, resulting in increased transmission loss of the optical fiber. On the other hand, in the latter case, there is a limit to the manufacturing speed because the tape sandwiching the optical fiber is pressed and molded from both sides.

Furthermore, the thermoplastic resin to be extruded coated or the polyester of the tape has a larger thermal expansion coefficient than the thermosetting resin such as epoxy resin or silicone resin that is generally used for the primary coating material.

Therefore, when a tape-shaped optical fiber is made up of optical fiber, primary coating material, and tape material that have different coefficients of thermal expansion, the amount of contraction or expansion of each of the constituent materials will be different when left at low or high temperatures. It will be subject to the stress caused by this.

(Means for Solving the Problems) The present invention has been made for the purpose of improving the drawbacks of these conventional tape-shaped optical fibers. A tape that draws out optical fibers adjacent to each other, applies a resin composition that is cured by ultraviolet rays or electron beams of the same type as the coating material of the optical fibers to the portions of the optical fibers that do not exceed the common tangent, and then cures and integrates the tape. 1 is a method for manufacturing a shaped optical fiber.

(Function) The present invention uses a resin composition that is reactively cured by ultraviolet rays or electron beams, such as urethane acrylate, polyester acrylate, epoxy acrylate, etc., as a tape material for adhering between optical fibers, so the thermoplastic resin can be melt extruded or bonded. Much higher production speeds can be obtained compared to tape methods. The tape material is made of the same type of resin composition as the primary coating, which is cured by ultraviolet rays or electron beams, and the entire coating can be made of a single material to form a tape-shaped optical fiber, which reduces stress caused by differences in thermal expansion coefficients. It has stable transmission loss without being affected by Since no heat is applied during tape forming, it has features such as not being subjected to stress caused by thermal contraction of the primary covering material, tape material, etc. Therefore, it goes without saying that the resulting tape-shaped optical fiber has superior stability in transmission loss with respect to temperature compared to tape-shaped optical fibers obtained by extrusion or compression methods.

On the other hand, even when the primary coating material and the tape material are made of the same material, reaction curing of the tape material occurs due to irradiation with ultraviolet rays or electron beams. Since no entanglement occurs, the adhesive force between the two is relatively small.

Furthermore, since this tape material is applied and cured within a range that does not cross the common tangent line of multiple optical fibers, the tape material only connects adjacent optical fibers,
Do not connect directly to multiple optical fibers.
Therefore, the obtained tape-shaped optical fiber can be torn relatively easily to form a single optical fiber. This is a great advantage in connection work.

(Example) The outline of the present invention will be explained with reference to FIGS. 1 and 2. A plurality of optical fibers 1 having a primary coating are supplied, arranged in a planar manner by an arraying device 2, coated with a resin composition that is reactively hardened by ultraviolet rays or electron beams by a resin coating device 3, and then coated with a resin composition that is reactively hardened by ultraviolet rays or electron beams by an ultraviolet ray or electron beam irradiating device 4. It is hardened and wound up by a winding device 5.

In the case of the present invention, tape-shaped optical fibers having different cross-sectional structures can be manufactured by changing the shape of the resin coating device 3. For example, by dropping a resin composition onto the contact surface of arranged optical fibers and curing it with ultraviolet rays or the like, a tape-shaped optical fiber having a cross-sectional structure as shown in FIG. 2a can be obtained.

Further, by applying the resin composition by dipping or other means and removing the excess with a doctor knife, a tape-shaped optical fiber having the cross-sectional structure shown in FIG. 2b can be obtained.

Examples are shown below.

A graded optical fiber base material with a relative refractive index difference of 1.0% manufactured by the VAD method was made into an optical fiber with a core diameter of 50 μm and an outer diameter of 125 μm in a carbon resistance furnace. Outer diameter of urethane acrylate composition
The film was coated to a thickness of 300 μm, and then cured using a mercury lamp with an output of 80 W/cm and a length of 26 cm at a position 10 cm directly below it, and then rolled up.

The five optical fibers thus obtained were arranged in a horizontal row using an arrangement device with rollers and comb teeth, and passed through a container containing a urethane acrylate composition of the same type as the primary coating material. The excess resin composition was removed by applying a doctor knife to the top and bottom, and the tape-shaped optical fiber was passed between two mercury lamp furnaces with an output of 80 W/cm and a length of 26 cm to obtain a tape-shaped optical fiber having the cross-sectional structure shown in FIG. 2b.

The urethane acrylate composition used was Desolite 950x039 manufactured by Desoto, USA.

The loss value of the five-core tape fiber obtained is the average
2.40dB/Km, maximum 2.55dB/Km, minimum 2.30dB/Km
(both 0.85 μm). Also, the maximum change in transmission loss in the temperature range of +80℃ to -40℃ is
It was 0.10dB/Km.

(Effects of the invention) As explained above, the present invention has a fast manufacturing speed,
In addition, a stable, high-density tape-shaped optical fiber with little stress caused by differences in thermal expansion coefficients can be obtained.

On the other hand, although this tape-shaped optical fiber is integrated with the same type of resin, it can be easily torn to form a single optical fiber.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of an embodiment of the manufacturing method of the present invention. FIGS. 2a and 2b are diagrams showing one form of a tape-shaped optical fiber obtained by the present invention. DESCRIPTION OF SYMBOLS 1... Primary coated optical fiber supply device, 2... Arranging device, 3... Resin composition coating device, 4... Ultraviolet ray or electron beam irradiation device, 5
... Winding device, 6 ... Optical fiber, 7 ... Primary coating, 8 ... Tape material.

Claims (1)

[Claims] 1. A plurality of pre-coated and wound optical fibers are drawn out adjacently, and a resin composition that is cured by ultraviolet rays or electron beams of the same type as the coating material of the optical fibers is applied to the portions of the optical fibers that do not exceed the common tangent line. 1. A method for manufacturing a tape-shaped optical fiber, the method comprising: curing the optical fiber and then curing the fiber to integrate it.