JPS6016837A - Optical fiber coated with plastic - Google Patents

Abstract

PURPOSE:To improve oil resistance of optical fiber, by forming coating layer of a polyfluoroalkyl methacrylate or a polyfluoroalkyl acrylate on the outside of a glass core of optical fiber or optical fiber having a plastic coating layer. CONSTITUTION:A coating layer of a polymer such as a polyfluoroalkyl methacrylate, e.g., trifluoroethyl methacrylate, tetrafluoropropyl methacrylate, octylfluoropentyl methacrylate, etc. is formed on the outside of a glass core of optical fiber or optical fiber having a plastic coating layer. Or, a coating layer of a polymer such as a polyfluoroalkyl acrylate, e.g., trifluoroethyl acrylate, tetrafluoropropyl acrylate, octylfluoropentyl acrylate, etc. is made.

Description

Detailed Description of the Invention [Background and Objectives of the Invention] The present invention relates to a plastic-sheathed optical fiber, and particularly to a plastic-coated optical fiber in which a plastic cladding layer is provided on the surface of a glass fiber core, or a glass fiber core. The present invention relates to a plastic-coated optical fiber that has seven plastic coating layers such as cladding and precoating on the surface of the fiber, and further has a plastic reinforcing layer on the outside thereof.

Conventionally, plastic-coated optical fibers, which have a plastic cladding and a silicone resin coating layer directly on the surface of the core glass fiber, have a higher numerical aperture and are less expensive than optical fibers whose cladding is glass. , used in optical fibers intended for relatively short-distance optical transmission.

However, although silicone resin has excellent heat resistance, it has poor oil resistance and will etch when soaked in mineral oil, making it unsuitable for lifting platforms such as transformers and thyristors that are submerged in oil. It was appropriate.

As a cladding material with low refractive index and good oil resistance,
Polyvinylidene butonide, tetrafluoride-hexabutylene ethylene copolymer, and the like are known. However, all of them have poor adhesion to glass, and although it is possible to improve this to some extent by modifying them to give them adhesive properties, it cannot be said that this is sufficient in terms of multiplicity.

This is a conventional plastic-covered optical fiber.The glass fiber surface is coated with a cladding or pre-coat layer made of silicone resin, epoxy resin, or laminate resin, and then an oil-resistant polyamide fiber layer is further coated on the outside for reinforcement. However, there is a limit to the manufacturing speed and it is difficult to increase productivity.

On the other hand, materials that can be cured by ultraviolet light have been proposed for the cladding and precoat layers, and for the reinforcing layer, a method of melting and extruding plastic has been proposed, but in order to make the reinforcing layer thinner, the extrusion conditions must be changed. There is a problem that strict control is required and it is easy to increase the speed, and furthermore, it is difficult to coat in the same line as the cladding and precoat layer.

SUMMARY OF THE INVENTION An object of the present invention is to provide a plastic-coated optical fiber which can solve the above-mentioned problems, greatly improve productivity, and has excellent oil distribution.

[Summary of the invention]

The present invention is characterized in that a coating layer of a polyfluoroalkyl methacrylate polymer or a polyfluoroalkyl acrylate polymer is provided on the outside of the glass core of the optical fiber or the glass fiber having a plastic coating layer. It is something.

The plastic-coated optical fiber of the present invention does not include glass fibers made of non-silica glass used in ordinary optical transmission glass fibers, quartz glass doped with a small amount of components, or multi-component glass. t-sill. In the glass fiber or the glass fiber having a honey plastic coating layer (the polymer provided on the outside of the glass fiber), the polyfluoroargyl mecrylate-1.
For example, fluorine-containing monomers such as trifluoroethyl acrylate, tetrafluoropropyl methacrylate, octylfluoropentyl methacrylate, polyfluoroalkyl acrylate acrylate, tetrafluoropropyl acrylate, octylfluoropentyl acrylate, etc. A coating layer of a polymer obtained by heating and polymerizing the mixture with a polymerization catalyst, a polymerization regulator, etc. is provided.

In order to obtain these polymers, monomers may be polymerized alone or two or more components may be mixed and polymerized, and in some cases, monomers other than these may be added for polymerization.

Furthermore, crosslinking may be performed by electron beam irradiation or the like.

〔Example〕

The present invention will be explained in detail below.

First, as shown in FIG. 1, a plastic-coated optical fiber in which a cladding 2 of the plastic polymer is directly provided on a glass fiber core 1 will be described.

Example 1 Quartz glass was heated and drawn in a drawing furnace to form a glass core of an optical fiber with an outer diameter of 150μ, and a polymer of octylfluoropentyl methacrylate melted at about 200°C was fed into a resin bath equipped with a coating die. Then, the glass core was passed through the coating die and coated to a thickness of 60 μm.

Then, it was immediately passed through a heating furnace at about 650°C to perform baking. This plastic? AaE-t7 Aiva,
When immersed in transformer oil at 70°C, there was very little change in weight, and the adhesion to glass was strong.Also, almost no increase in conduction loss was observed.

Example 2 Using tetrafluoropropyl acrylic V-) containing methyl ether ketone as the cladding material, the same procedure as in Example 1 was carried out to obtain Itoyoshi fruits of Example 1 and 1 Tsukasa.

Next, as shown in Fig. 2, the optical fiber core 1 is covered with a glass or plastic cladding 2, and 6 plastic precoats, and on the outside is a polyfluoroalkyl methacrylate plastic coating. explain about.

Example 6 A polymer of octyl flumeropentyl methacrylate melted at about 200°C was supplied into a resin bath in which a coating bath had been heated, and coated with RCC15C resin (manufactured by Brace Co., Ltd.). The glass optical fiber whose surface has been hardened with ultraviolet rays 4 is passed through the coating die to undergo polymerization 121=i, and immediately passed through a heating furnace at about 650°C to undergo baking τ1. <itsuta. This plastic-coated optical fiber can be manufactured in a single process from drawing the final fiber to baking it, and moreover, there is no damage during twisting, and there is almost no deterioration in transmission characteristics due to microbending. Ta.

The change in weight when immersed in transformer oil at 70'C was extremely small, and the increase in transmission loss was almost unbearable.

Example 4 (adding 6 parts by weight of benzophenone to 100 parts by weight of tetrafluoropropyl acrylate) - A uniformly mixed photocurable composition was supplied into a resin bath, and the same optical fiber as in Example 6 was prepared in the same manner. The polymer was coated by passing it through a coating die, and then using a high-pressure mercury lamp (80 W/cm), the irradiation distance was 100 m.

Curing was performed at a speed of 70 m/H.

The performance of this plastic coated optical fiber was similar to that of Example 6.

〔Effect of the invention〕

As explained below, the plastic-coated optical fiber of the present invention has excellent oil resistance, and the manufacturing process from drawing the core glass fiber to coating the outermost layer with plastic can be performed in one step. It's possible.

Therefore, in its production, it is possible to enjoy the industrial effects of significantly improving both performance and productivity.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view of the optical fibers of Examples 1 and 2 of the present invention, and FIG. 2 is a cross-sectional view of the same optical fibers of Examples 6 and 4. 1; Core, 2.2'; Clad, 6; Precoat, 4
; Reinforcement layer. Yu 1 Kyou Z-huge

Claims (1)

[Claims] (1) A plastic coating characterized by providing a coating layer of a polyfluoroalkyl methacrylate polymer or a polyfluoroalkyl acrylate polymer on the outside of an optical fiber having a glass core or a plastic coating layer. optical fiber.