JPH05288948A - Optical transmission hose - Google Patents

Abstract

PURPOSE:To prevent the hollow part of a clad from being put in a negative pressure state even when the optical transmission hose is used at low temperature, to maintain transparency, and to prevent a kink by setting the pressure of a core material high. CONSTITUTION:A liquid or fluid core material 2 which has a higher refractive index than a clad material 1 in a hollow tube shape is charged in the clad material 1 and both the end opening parts of the clad material 1 are closed with sealing stoppers 3. The pressure of the core material 2 is made high. A material which has plasticity like plastic and elastomer and can be molded in a tube shape and is low in refractive index is used for the clad material 1 in the hollow tube shape. A liquid or fluid transparent material which has a higher refractive index than the clad 1 is used for the core material 2 charged in the hollow part of the clad material 1 in the hollow tube shape. The internal pressure of the core material 2 is selected corresponding to the quality, and internal diameter and external diameter of the clad material 1, and the temperature range of use.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical transmission hose in which a core material is in a liquid or fluid state, and more specifically, it prevents gas from entering the core material and is excellent in flexibility. The present invention relates to an optical transmission hose that does not lose its function over a long period of time.

[0002]

2. Description of the Related Art Conventionally known optical fibers include inorganic glass based optical fibers such as quartz glass and multi-component glass, and plastic based optical fibers such as polymethylmethacrylate and polystyrene, both of which have a solid core and clad material. It is an all-solid-state optical fiber made of material.

Although these optical fibers have excellent characteristics, they are limited in flexibility because they are made of glass or a hard plastic material, and when they have a large diameter for transmitting a large amount of light. , Diameter 10-1000μ
It is necessary to bundle a large number of optical fibers of about m.
However, no matter how densely the optical fibers are bundled, since the voids remain between the fibers, the effective light-receiving area when light is incident becomes narrow, resulting in poor efficiency and a very high cost. was there.

As a solution to these problems of the all-solid-state optical fiber, the inventors of the present invention disclosed in Japanese Patent Laid-Open No. 64-809.
No. 10, 64-80912, proposed an optical transmission hose using an optical transmission medium that is liquid at room temperature. In these liquid optical fibers, a clad material composed of a flexible hollow tubular body is filled with a liquid core material having a refractive index higher than that of the clad material, and openings at both ends of the clad material are closed by window materials. Therefore, it was easy to increase the aperture, had a wide effective light receiving area, high efficiency, and was excellent in economic efficiency.

[0005]

However, although the liquid type optical fiber has excellent characteristics as described above, since the rigidity is maintained by the clad material made of the flexible hollow tubular body, the force such as bending is applied to the fiber. When applied, the clad material was likely to be kinked (broken) and the flexibility was not sufficient. In addition, since it is easy to kink during transportation and construction, careful attention was required.

Further, there is a problem that gas changes into the core liquid due to changes in the temperature of the environment in which it is used, and the transparent performance is degraded. Since the core material is a liquid, the expansion coefficient is generally larger than that of a hollow tubular clad material made of a resin material, and therefore at a low temperature, the volume of the core liquid becomes smaller than the inner volume of the clad material, Since the hollow portion of the clad material is in a negative pressure state, gas permeates through the tube wall of the clad material, and this gas causes bubbles in the core liquid.

As a liquid type optical fiber which solves the problem of gas invasion, for example, British Patent 1450608.
There are optical fibers proposed in the issue. This optical fiber consists of a core liquid reservoir connected to a hollow tubular clad material, and the core liquid is supplied from the reservoir even when the volume of the core liquid becomes small at low temperatures, so the hollow part of the clad material is under negative pressure. It is possible to prevent gas from entering the core liquid without causing a state.

However, in this optical fiber, when connecting the reservoir and the hollow tubular clad material, it is necessary to make a hole for liquid inflow in the clad material,
Light scattering occurs at the holes, and the transparency is reduced. Further, since the reservoir is attached, there is a problem that it is heavy and expensive.

The present invention has been made in view of the above circumstances.
It has excellent flexibility and handleability, can prevent gas from entering the core liquid, and can maintain the transparency of the optical transmission hose over a wide temperature range for a long period of time. Intended to provide hoses.

[0010]

Means and Actions for Solving the Problems As a result of intensive studies for achieving the above-mentioned object, the present inventors have found that a liquid or fluid state having a higher refractive index than the clad material is inside the hollow tubular clad material. In a light-transmitting hose filled with the core material and closing both ends of the clad material with sealing plugs, when the pressure of the core material is increased, the hollow part of the clad is negative even when used at low temperature. The pressure does not occur, gas does not permeate through the tube wall of the clad material and bubbles do not occur in the core liquid, so the transparency of the optical transmission hose is maintained over a wide temperature range, and there is no kink. Since it can be prevented, it is possible to further improve flexibility and handleability, it is possible to prevent a decrease in transparency due to light scattering at the kink portion, and further, to reduce the pressure of the core material. Since the hollow portion of the clad material is prevented from being in a negative pressure state only by making it difficult, it was found that the weight does not increase and the manufacturing cost is low, and the present invention has been accomplished. It was

The present invention will be described in more detail below. The optical transmission hose of the present invention comprises a hollow tubular clad material,
In an optical transmission hose filled with a liquid or fluid core material having a refractive index higher than that of the clad material, and closing both end openings of the clad material with sealing plugs, the pressure of the core material is increased. It will be.

FIG. 1 shows the basic structure of the optical transmission hose of the present invention. In FIG. 1, 1 is a hollow tubular clad material, 2 is a liquid or fluid core material filled in the clad material 1, 3
Are sealing plugs for holding the internal pressures of the hollow portions of the core material and the clad material, and 4 are end fasteners for preventing the sealing plug 3 from coming off and the core material 2 from leaking.

Here, as a material for forming the hollow tubular clad material 1, it is preferable to use a flexible material such as plastic or elastomer, which can be formed into a tube and has a low refractive index. .. Specific examples thereof include polyethylene, polypropylene, polyamide, polystyrene, ABS, polymethylmethacrylate, polycarbonate, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyethylene-vinyl acetate copolymer, polyvinyl alcohol, polyethylene-polyvinyl alcohol copolymer. Polymer, fluororesin, silicone resin, natural rubber, polyisoprene rubber, polybutadiene rubber, styrene-butadiene copolymer, butyl rubber, halogenated butyl rubber, chloroprene rubber, acrylic rubber, EPDM, acrylonitrile-butadiene copolymer, fluororubber, Silicon rubber etc. are mentioned.

Of these, fluorine-based polymers having a low refractive index are particularly preferable, and specifically, silicone-based polymers such as polydimethylsiloxane polymer, polymethylphenylsiloxane polymer, fluorosilicone polymer, polytetrafluoroethylene (PTFE), and tetrafluorine. Ethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFE), polychlorotrifluoroethylene (PCT)
FE), tetrafluoroethylene-ethylene copolymer (ETF
E), polyvinylidene fluoride, polyvinyl fluoride, vinylidene fluoride-trifluorochloroethylene copolymer, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-hexafluoropropylene-tetrafluoroethylene Examples thereof include a terpolymer, tetrafluoroethylene propylene rubber, and a fluorinated thermoplastic elastomer.

These materials may be used alone or as a mixture of two or more kinds, and may be used as a single tube or a multiple tube. Furthermore, only the inner surface in contact with the core liquid can be subjected to a treatment such as a smoothing treatment by a method such as coating or double extrusion.

As the core material 2 filled in the hollow portion of the hollow tubular clad material 1, a liquid or fluid transparent material having a higher refractive index than the clad material is used. Specific examples thereof include aqueous solutions of inorganic salts, polyhydric alcohols such as ethylene glycol and glycerin, silicone oils such as polydimethylsiloxane and polyphenylmethylsiloxane, hydrocarbons such as polyether, polyester and liquid paraffin, and trifluorochlorochloride. Examples thereof include halogenated hydrocarbons such as ethylene oil, phosphoric acid esters such as tris (chloroethyl) phosphate and trioctylphosphate, and polymer solutions obtained by diluting a polymer with a suitable solvent.

The material forming the sealing plug 3 is inorganic glass,
It can be selected from organic glass, metals, inorganic materials, plastics and the like according to the purpose. For example, as shown in FIG. 2, the sealing plugs 31 and 32 are transparent in order to allow light to enter the light transmission hose body and to act as a window material for light that transmits the light. However, for example, when the light is emitted from the side surface of the hose as shown in FIG. 3, the end sealing plug 32 does not necessarily have to be transparent.

Specifically, when transparency is required as the material of the sealing plug, quartz glass, multi-component glass, sapphire, crystal, polyethylene, polypropylene, ABS resin, acrylonitrile-styrene copolymer resin, styrene. Butadiene copolymer, acrylonitrile / styrene copolymer resin, styrene / butadiene copolymer, acrylonitrile / EPDM / styrene terpolymer, styrene /
Methyl methacrylate copolymer, methacrylic resin, epoxy resin, polymethylpentene, allyl diglycol carbonate resin, spirane resin, amorphous polyolefin, polycarbonate, polyamide, polyarylate, polysulfone, polyallylsulfone, polyethersulfone, polyetherimide , It is preferable to use transparent materials such as polyimide, polyethylene terephthalate, diallyl phthalate, fluororesin, polyester carbonate, and silicone resin. Among them, quartz glass, Pyrex glass, inorganic glass such as multi-component glass is not only transparent but also heat resistant. Since it has excellent properties and is chemically stable, the core material 2 contacting at the end face 3a,
The end face 3b does not chemically react with the contacting gas or moisture and can provide excellent performance for a long period of time.

When transparency is not required, a metal or ceramic material can be used in addition to the above materials. In this case, it is preferable to polish at least the surface of the sealing material that is in contact with the core liquid or to provide a reflective film in order to reflect the light with the sealing material and increase the light emission from the side surface.

The end fastening portion 4 is provided to prevent the sealing plug from coming off and the core liquid from leaking. For example, tightening with a hose band or the like, winding with a wire wire,
Mechanical sealing such as tightening through a sleeve, an O-ring, packing, etc., heat shrinkage treatment, adhesive treatment, sealing with a curable material, etc. can be performed alone or in combination.

Here, the internal pressure of the core material can be selected according to the material of the clad material, the inner diameter and the outer diameter, and the temperature range in which the optical transmission hose is used. For example, when used in the temperature range of 0 to 50 ° C, the internal pressure at 0 ° C is 0 kg / c.
It is preferable to set the internal pressure so that the internal pressure at m ² or more and at 50 ° C. becomes smaller than the withstand pressure of the clad material. Even in other temperature ranges, the internal pressure at the lower limit temperature is 0 kg /
It is preferable to set the internal pressure so that the internal pressure is not less than cm ² and at the upper limit temperature is smaller than the withstand pressure of the clad material. Also, as a method of increasing the pressure of the core material higher than the pressure of the clad material, after inserting and fastening one sealing plug, press the sealing plug from the other end for a certain length. You can

Here, when the internal pressure of the core material becomes high at a high temperature but the pressure resistance of the clad material is low, the pressure resistance is increased by a method such as coating with a metal or plastic material, winding a tape-like material, or fiber reinforcement. A method of increasing can be adopted.

[0023]

EXAMPLES The present invention will be specifically described below by showing Examples and Comparative Examples, but the present invention is not limited to the following Examples.

[Example 1] Inner diameter 12 mm, outer diameter 13 m
m, 3 m in length, a pressure gauge was attached to one end of a hollow tubular clad material made of a tetrafluoroethylene / hexafluoropropylene copolymer, and trioctyl phosphate was charged from the other open end. A quartz rod having a diameter of 13 mm and a length of 50 mm was inserted so that the pressure was 4 kg / cm ² at room temperature, and the end portion was tied with a wire. The internal pressure of this optical transmission hose for measuring internal pressure at −10 ° C. was maintained at 0.5 kg / cm ² .

A quartz rod was inserted in place of the pressure gauge, and an optical transmission hose manufactured by the same method as described above was used.
It was left to stand in a refrigerator at 0 ° C, but no air entered even after about 6 months, and high light transmittance was maintained.

In addition, this optical transmission hose has a radius of 200 mm.
Kink did not occur even when bent to the end, and showed excellent flexibility and handleability.

[Comparative Example] The internal pressure at room temperature was 0 kg / cm ^2.
The internal pressure at 10 ° C. of the optical transmission hose for measuring internal pressure produced by the same material and method as in Example 1 was 50 mm.
It was Hg.

A quartz rod was inserted in place of the pressure gauge, and an optical transmission hose manufactured by the same method as above was used at 10 ° C.
It was left standing in the refrigerator, but after 1 week, about 2 ml was added to the core.
Air was generated, and the light transmittance decreased to 40% from 70% before entering the air. When this optical transmission hose was bent, a kink occurred at a radius of 400 mm.

[0029]

EFFECTS OF THE INVENTION According to the present invention, the flexibility and handleability are excellent, and the transparency of the optical transmission hose is maintained for a long period of time in a wide temperature range by preventing gas from entering the core liquid. It is possible to obtain a lightweight and inexpensive optical transmission hose.

[Brief description of drawings]

FIG. 1 is a sectional view showing a basic configuration of an optical transmission hose of the present invention.

FIG. 2 is an explanatory diagram illustrating an optical transmission hose of the present invention.

FIG. 3 is an explanatory diagram illustrating an optical transmission hose of the present invention.

[Explanation of symbols]

 1 clad material 2 core material

Claims (1)

[Claims] 1. A light obtained by filling a hollow tubular clad material with a liquid or fluid core material having a refractive index higher than that of the clad material, and closing both end openings of the clad material with sealing plugs. A transmission hose, wherein the pressure of the core material is increased.