JP3161036B2 - Light transmission hose - Google Patents

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 having a core material in a liquid or fluid state, and more particularly to an optical transmission hose in which gas is prevented from entering the core material and has excellent flexibility. The present invention relates to an optical transmission hose whose function is not impaired 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 polymethyl methacrylate and polystyrene. This is an all-solid-state optical fiber made of a material.

[0003] Although these optical fibers have excellent characteristics, they are made of glass or a hard plastic material, so that their flexibility is limited. In addition, when optical fibers having a large diameter are required to transmit 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, there is a gap between the fibers, which reduces the effective light receiving area at the time of light incidence, resulting in poor efficiency and extremely high cost. was there.

As a solution to these problems of the all-solid-state optical fiber, the present inventors have disclosed Japanese Patent Application Laid-Open No. 64-809.
10, No. 64-80912 (U.S. Pat.
382, No. 3,814,497) proposed an optical transmission hose using an optical transmission medium which is liquid at room temperature. In these liquid optical fibers, a liquid core material having a refractive index higher than that of the clad material is filled in a clad material made of a flexible hollow tubular body, and both ends of the clad material are closed with window materials. Therefore, the diameter can be easily increased, the effective light receiving area is wide, the efficiency is high, and the economy is excellent.

[0005]

However, as described above, although the liquid optical fiber has excellent characteristics, when used for a long period of time, gas enters into the core liquid and the transparency is reduced. There was a point. This is because the core material is a liquid, so its expansion coefficient is larger than that of a hollow tubular clad material that is generally made of a resin 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 to be generated in the core liquid.

As a liquid optical fiber which has solved such a problem of gas intrusion, for example, British Patent No. 1450608
There is an optical fiber proposed in the issue. In this optical fiber, the core liquid reservoir is connected to the hollow tubular cladding material. Even if the volume of the core liquid becomes small at a low temperature, the core liquid is supplied from the reservoir, so that the hollow portion of the cladding material has a negative pressure. It is possible to prevent gas from entering the core liquid without being in a state.

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

[0008] The present invention has been made in view of the above circumstances,
It is an object of the present invention to provide a lightweight and inexpensive optical transmission hose that can prevent gas from entering the core liquid and maintain the transparency of the optical transmission hose over a wide temperature range over a long period of time.

[0009]

The present inventors have conducted intensive studies to achieve the above object, and as a result, a liquid or fluid state having a refractive index higher than that of the clad material is provided inside the hollow tubular clad material. In an optical transmission hose in which the core material is filled and the openings at both ends of the clad material are closed with sealing plugs, the outer periphery of the clad material is coated with polyvinyl alcohol or ethylene-vinyl alcohol copolymer having a high gas barrier property. In this case, even when the core liquid is used at a low temperature and the internal pressure of the core liquid is reduced and the hollow part of the clad is in a negative pressure state, the gas permeates through the cladding material wall and bubbles are generated in the core liquid. Can be effectively prevented, the transparency of the optical transmission hose is maintained over a wide temperature range, and the outer periphery of the clad material is coated with the material having a high gas barrier property. Since so as to prevent the hollow portion of the cladding material is a negative pressure state by it without the weight is increased, also by finding that it is possible to inexpensively manufacture, the present invention has been accomplished.

Hereinafter, the present invention will be described in more detail. The optical transmission hose of the present invention comprises a hollow tubular clad material,
A liquid or fluid core material having a higher refractive index than the clad material is filled, and in an optical transmission hose in which both ends of the clad material are closed with sealing plugs, the outer periphery of the clad material has gas barrier properties. It is coated with a high material.

FIG. 1 shows an example 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 is a sealing plug for maintaining the internal pressure of the hollow portions of the core material and the clad material, This is a gas barrier coating material that coats the outer periphery of the four-clad material 1. Reference numeral 5 denotes a terminal fastener for preventing the sealing plug 3 from coming off or the core material 2 from leaking.

Here, as a material for forming the hollow tubular cladding material 1, it is preferable to use a material having flexibility, such as plastic or elastomer, which can be formed into a tube shape and has a low refractive index. . Specific examples thereof include polyethylene, polypropylene, polyamide, polystyrene, ABS, polymethyl methacrylate, polycarbonate, polyvinyl chloride, polyvinylidene chloride, polyvinyl acetate, polyethylene-vinyl acetate copolymer, polyvinyl alcohol, and polyethylene-polyvinyl alcohol. 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 and the like can be mentioned.

Of these, silicone polymers and fluorine polymers having a low refractive index are particularly preferred. Specifically, silicone polymers such as polydimethylsiloxane polymer, polymethylphenylsiloxane polymer and fluorosilicone polymer, and polytetrafluoroethylene (P
TFE), ethylene tetrafluoride-propylene hexafluoride copolymer (FEP), ethylene tetrafluoride-perfluoroalkoxyethylene copolymer (PFE), polychlorotrifluoroethylene (PCTFE), ethylene tetrafluoride-ethylene Copolymer (ETFE), polyvinylidene fluoride, polyvinyl fluoride, vinylidene fluoride-ethylene trifluoride ethylene chloride copolymer, vinylidene fluoride-propylene hexafluoride copolymer, vinylidene fluoride-propylene hexafluoride- Examples include a tetrafluoroethylene terpolymer, a tetrafluoroethylene propylene rubber, and a fluorine-based thermoplastic elastomer.

These materials can be used alone or in combination of two or more, and can be used as a single tube or a multi-tube. Further, a treatment such as a smoothing treatment can be performed on only the inner surface in contact with the core liquid 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 polyethers, polyesters, liquid paraffins, and trifluorinated chlorides. Examples include halogenated hydrocarbons such as ethylene oil, phosphates such as tris (chloroethyl) phosphate and trioctyl phosphate, and polymer solutions obtained by diluting a polymer with an appropriate solvent.

The material forming the sealing plug 3 is inorganic glass,
It can be selected from organic glass, metal, inorganic material, plastic and the like according to the purpose. For example, as shown in FIG. 2, the sealing plugs 31 and 32 must be transparent in order to make light incident on the optical transmission hose body or to act as a light window material for emitting transmitted light. However, when light is emitted from the side of the hose as shown in FIG. 3, for example, the sealing plug 32 at the end does not necessarily have to be transparent.

When transparency is required for the material of the sealing plug, specifically, quartz glass, multi-component glass, sapphire, inorganic glass such as quartz, 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, polymethyl Pentene, allyl diglycol carbonate resin, spirane resin, amorphous polyolefin, polycarbonate, polyamide, polyarylate, polysulfone, polyallylsulfone, polyethersulfone, polyetherimide, polyimide, polyethylene It is preferable to use an organic glass or a plastic transparent material such as terephthalate, diallyl phthalate, fluororesin, polyester carbonate, or silicon resin.In particular, quartz glass, Pyrex glass, and inorganic glass such as multi-component glass are not only transparent, Since it is excellent in heat resistance and also chemically stable, the core material 2 contacting at the end face 3a and the end face 3b
It does not react chemically with the gas or moisture contacting with it, and can provide excellent long-term performance.

When transparency is not required, stainless steel such as Cr-Fe and Cr-Ni-Fe, and metals and ceramic materials such as Al, Fe, Ti, Cu and Shinchu can be used in addition to the above materials. . In this case, in order to reflect light with the sealing material and increase light emission from the side surface, it is preferable to polish at least a surface of the sealing material which is in contact with the core liquid or to provide a reflective film.

As a material of the gas barrier coating material 4, polyvinyl alcohol or ethylene glycol is used as a material having a high gas barrier property and not impairing the flexibility of the optical transmission hose.
Use vinyl alcohol.

[0020]

The present invention has high gas barrier properties, high transparency,
Polyvinyl alcohol and ethylene-vinyl alcohol copolymer are used because they are excellent in environmental resistance and workability and are easily available. In this case, the coating material 4 is used.
Is preferably 0.01 to 10 mm, particularly preferably 0.5 to 2 mm.

In order to coat the outer periphery of the clad material 1 using these materials, methods such as coating, extrusion molding, winding of a tape-shaped material, and heat shrinkage treatment can be adopted. Further, a method of inserting an optical transmission hose in which the outer periphery of the clad material is not covered with the gas barrier material into a flexible tube formed of the gas barrier material can also be adopted. In this case, silicone oil, fluorine oil, ethylene glycol, or the like is used to prevent gas such as air existing in the gap between the optical transmission hose and the flexible tube from entering the optical transmission hose.
It is preferable to seal with water, a liquid such as liquid paraffin, or a polymer material such as silicone rubber or urethane rubber.

The terminal fastening portion 5 is provided for preventing gas from entering the joint end between the clad material 1 and the gas barrier coating material 4 in addition to preventing the sealing plug from coming off and the core liquid from leaking. Mechanical sealing such as tightening with a hose band, winding with a wire, etc., tightening via a sleeve, O-ring, packing, etc., heat shrinking treatment, adhesive treatment, sealing with a curable material, etc. Can be used alone or in combination. Above all, sealing by mechanical crimping using a base is suitably used, and iron, nickel, Fe—Cr—Ni alloy, aluminum, brass, titanium, and the like can be used as the material of the base.

[0024]

EXAMPLES The present invention will be described below in detail with reference to examples and comparative examples, but the present invention is not limited to the following examples.

REFERENCE EXAMPLE 1 A hollow tubular clad material of 12 mm in inner diameter, 13 mm in outer diameter and 3 m in length made of a copolymer of ethylene tetrafluoride and propylene hexafluoride was coated with a polyvinyl chloride resin to a thickness of 1 mm. After filling the hollow portion of the obtained double tube with trioctyl phosphate, a quartz rod having a diameter of 13 mm and a length of 50 mm was inserted at both ends, and the end was tied with a wire.

The light transmission hose was allowed to stand in a refrigerator at -5 ° C., but air did not enter even after about 6 months had passed, and high light transmittance was maintained.

Reference Example 2 An optical transmission hose was produced in the same manner as in Reference Example 1, except that a polyethylene-vinyl acetate copolymer (vinyl acetate content: 25%) was used instead of the polyvinyl chloride resin as the coating material. .

The light transmission hose was left standing in a refrigerator at -5 ° C., but air did not enter even after about 6 months had passed, and high light transmittance was maintained.

Comparative Example An optical transmission hose was produced in the same manner as in Reference Example 1, except that the clad material was not coated.

When this light transmission hose was allowed to stand in a refrigerator at -5 ° C., about 1 ml of air was generated in the core after 2 days, and the light transmittance was reduced to 40% from 70% before the air was introduced. did.

[0031]

According to the present invention, the flexibility and handleability are excellent, and the invasion of gas into the core liquid is prevented to maintain the transparency of the optical transmission hose in a wide temperature range for a long period of time. And a light and inexpensive optical transmission hose can be obtained.

[Brief description of the drawings]

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

FIG. 2 is a sectional view showing another embodiment of the optical transmission hose of the present invention.

FIG. 3 is a sectional view showing another embodiment of the optical transmission hose of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Clad material 2 Core material 4 Gas barrier coating material

Continuation of the front page (56) References JP-A-57-30804 (JP, A) JP-A-64-80912 (JP, A) JP-A-64-80910 (JP, A) JP-A-64-54405 (JP) JP-A-64-40805 (JP, A) JP-A-64-9407 (JP, A) JP-A-60-33514 (JP, A) JP-A-63-237950 (JP, A) 2-63136 (JP, A) JP-A-4-72137 (JP, A) JP-A-62-43303 (JP, U) (58) Fields investigated (Int. Cl. ⁷ , DB name) G02B 6/00 G02B 6/20

Claims (1)

(57) [Claims] 1. A light in which a hollow or tubular clad material is filled with a liquid or fluid core material having a higher refractive index than the clad material, and openings at both ends of the clad material are closed with sealing plugs. In a transmission hose, an outer periphery of the clad material is coated with polyvinyl alcohol or an ethylene-vinyl alcohol copolymer.