JPH0414728Y2 - - Google Patents

Description

[Detailed Description of the Invention] "Purpose of the Invention" The present invention relates to the invention of an optical fiber, and is an attempt to obtain sufficient strength and durability in the primary coating layer of a silica-based optical fiber core.

Industrial applications Silica-based optical fiber with primary coating.

Prior Art Various studies have been made regarding the primary coating of silica-based glass optical fibers. That is, such a tight structure core wire made of silica-based glass optical fiber is generally coated with a first coat, then a buffer layer is formed, and then a second coat is applied. However, silicone resin is the main material used as the primary covering material.
Although various studies have been made, it is necessary for this one-sheet coating to have good adhesion to the glass and to be able to form a uniform coating.

The buffer layer requires a material with a low Young's modulus that has a cushioning effect to prevent microbending that occurs when external force is applied, and the material is generally silicone resin, and the secondary coating is polyamide resin. is considered to be the main subject.

Problems to be solved by the invention However, in the conventional products as described above, the primary coating is simply a coating film of silicone resin, which is unsatisfactory in terms of strength. They are generally brittle, susceptible to scratching forces, and lack reliability. Note that the stress-absorbing gel-type products used in some cases are also very brittle in this respect, making it difficult to obtain desirable durability.

``Structure of the invention'' Means for solving the problem Silicon rubber was applied to a film in which numerous fine fibers were formed between micro nodules by stretching a polytetrafluoroethylene resin film around a silica-based glass optical fiber. An optical fiber characterized by forming a primary coating that is impregnated and crosslinked.

Function: The polytetrafluoroethylene resin film is stretched to form numerous fine fibers between micro nodules, and the strength of the primary coating is appropriately increased, making it suitable for use in fiber manufacturing processes, cable production processes, and during installation. The glass fiber is not damaged even by external force, does not cause flaws on the surface of the glass fiber, and increases the strength of the optical fiber against microbending.

The impregnated silicone rubber provides a precise adhesive coating to the glass optical fiber, and also integrates the structure of the film consisting of the fine fibers and micro nodules to form a stable primary coating layer.

A buffer layer and a secondary coating can be effectively formed on the outer surface of the primary coating by an appropriate method.

EXAMPLE To explain a specific embodiment of the present invention as described above, in the present invention, a uniaxially stretched fired film 1 of a polytetrafluoroethylene resin film is used as the primary coating of a quartz-based optical fiber as described above. In one example of such a uniaxially stretched fired film, as shown in FIG. 1, a large number of micro nodules 11 are formed across the stretching direction. Fine fibers 12 are formed along the stretching direction, and voids 13 are formed between the fine fibers 12. In the present invention, such fine fibers 12
It is used by impregnating the voids with gel-type silicone rubber.

The stretched and fired film has a porosity of 50% or more, especially about 65 to 85%, and a pore size of about 0.1 μm to 10 μm, which can be easily obtained by stretching.
Stabilizes the structure formed by firing. This product is impregnated with the silicone rubber and crosslinked by heating. Of course, such silicone rubber impregnation and crosslinking may be carried out after the film 1 is wound around the quartz optical fiber 2 as shown in FIG. The optical fiber 2 may be wound after being impregnated with silicone rubber and cross-linked. It is clear that the tape-shaped film 1 and the optical fiber 2 may be wrapped along the length thereof, but in some cases, the ends of the film 1 may be appropriately polymerized in a spiral shape. It may be wrapped and coated in this state.

To explain a specific structural example, the outer diameter
As shown in FIG. 2, a polytetrafluoroethylene stretched porous combustion film (thickness 65 μm, porosity 70%,
A pore diameter of 1 μm) 1 is added and coated along the axial direction of the fiber 2, and silicone rubber (manufactured by Shin-Etsu Chemical Co., Ltd.) is coated on this.
KE-106) was impregnated and then heated to 100°C to cause crosslinking. The overall outer diameter of this thing is approximately 500μm
After the primary coating, the buffer layer and secondary coating were formed in the same manner as in the conventional method described above to produce a product.

A similar product can also be obtained by coating the fiber 2 with a film 1 impregnated with gel type silicone rubber (for example, KE-104GEL manufactured by Shin-Etsu Chemical Co., Ltd.) and crosslinking it.

The device according to the present invention as described above uses a tissue material in which the fibers 12 are finely arranged in a spider web shape in the primary coating, so the strength of the primary coating is extremely high, and the cable manufacturing process and cable forming process are , a transmission line that does not cause flaws on the two sides of the glass fiber even when external forces are applied during installation work, use environments, etc., greatly improves the strength of the optical fiber against micro-bends, and that can be used satisfactorily. It was confirmed that it is possible to form

``Effect of the invention'' The invention as explained above can sufficiently increase the strength of the primary coating, which is important for this type of optical fiber, and can provide a product that can withstand harsh working conditions and has high durability. This is a device with great industrial effects.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, and FIG. 1 is an explanatory diagram showing an enlarged structure of the stretched porous fired film of polytetrafluoroethylene resin membrane used in the present invention, and FIG. 2 is a part of the product according to the present invention. FIG. 3 is a side view showing a target peeled state. In these drawings, 1 is a polytetrafluoroethylene stretched porous film, 2 is a quartz optical fiber, 11 is a minute nodule, 12 is a fine fiber, and 13 is a void.

Claims (1)

[Scope of utility model registration request] Forming a primary coating on the circumferential surface of a silica-based glass optical fiber by impregnating and crosslinking silicone rubber on a film in which numerous fine fibers are formed between micronodules by stretching a polytetrafluoroethylene resin film. An optical fiber characterized by