JPH07198947A - Optical transmission tube - Google Patents

Abstract

PURPOSE:To obtain an optical transmission tube having high surface luminance which can be safely used in an environment such as in water by specifying the average roughness of the inner surface of the clad material. CONSTITUTION:The optical transmission tube consists of a transparent cylindrical clad material 1, transparent core material which fills the clad material 1 and sealing caps 3. In this method, as for the material to form the hollow tubular clad material 1, a flexible material which can be formed into a tube and has lower refractive index than that of the core material 2 is used. The average roughness of the inner surface of the clad material 1 in contact with the core material 2 is specified to >=0.05mum, preferably 0.05-10mum, and more preferably 0.1-5mum. Thereby, during light entering through the one end surface of the core material 2 transmits through the core material 2, not all of the light is reflected on the inner surface of the clad material but partly effectively transmits through the clad material 1 to emit outside. Thus, the luminance of the inner surface of the the optical transmission tube is increased.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light transmission tube, and more particularly to a light transmission tube in which the light emission brightness on the outer surface of the light transmission tube is increased by adjusting the roughness of the inner surface of the clad material.

[0002]

2. Description of the Related Art Conventionally, the problems to be solved by the invention
A neon tube is a luminous body that can emit light over a long length. However, the neon tube requires an electric power of about 1 kW per 1 m, and a long voltage requires a high voltage proportional to its length, so that the length of about 3 to 5 m is practically limited. In addition, since there is a problem of electric leakage in water, it cannot be used in water. Further, since the neon tube is made of glass, there is a problem that the glass tube is broken.

Therefore, the applicant has filed Japanese Patent Application Laid-Open No. 62-2319.
In JP-A-04-04, an optical transmission tube that can be used with a length of 50 m is proposed. This light transmission tube can be used in water and in environments where there is a risk of explosion, and it does not require complicated processing such as glasswork and has good workability, but the light emission brightness of the peripheral surface is neon. 1/2 to 1 of tube
It is about / 4.

The present invention has been made in view of the above circumstances.
An object of the present invention is to provide an optical transmission tube which has high peripheral brightness and can be safely used even in an environment such as underwater.

[0005]

Means for Solving the Problems and Actions The inventors of the present invention have conducted extensive studies to achieve the above object, and as a result, an optical transmission tube comprising a transparent core material and a transparent tubular clad material having a refractive index lower than that of the core material. In the above, it was found that the peripheral surface has high brightness when the average roughness Ra of the inner peripheral surface of the clad material is 0.05 μm or more, and the present invention has been completed.

The present invention will be described in more detail below. The optical transmission tube of the present invention comprises a transparent core material and a transparent tubular clad material having a refractive index lower than that of the core material. The average roughness of the peripheral surface is 0.
It is formed to have a thickness of 05 μm or more.

FIG. 1 shows an example of the optical transmission hose of the present invention. In FIG. 1, 1 is a transparent tubular clad material, 2 is a transparent core material filled in the clad material 1, and 3 is a sealing plug.

Here, as a material for forming the hollow tubular clad material 1, a material such as plastic or elastomer which has flexibility, can be formed into a tube shape, and has a lower refractive index than the core material is used. . 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, silicone-based polymers and fluorine-based polymers having a low refractive index are particularly preferable. Specifically, silicone-based polymers such as polydimethylsiloxane polymer, polymethylphenylsiloxane polymer and fluorosilicone polymer, and polytetrafluoroethylene (P
TFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroethylene-perfluoroalkoxyethylene copolymer (PFE), polychlorotrifluoroethylene (PCTFE), tetrafluoroethylene-ethylene Copolymer (ETFE), polyvinylidene fluoride, polyvinyl fluoride, vinylidene fluoride-trifluoroethylene chloride copolymer, vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-propylene hexafluoride- Examples thereof include tetrafluoroethylene terpolymer, tetrafluoroethylene propylene rubber, and fluorine-based thermoplastic elastomer. These materials can be used alone or as a mixture of two or more kinds.

In the present invention, the average roughness of the inner peripheral surface 1a of the clad material 1 in contact with the core material 2 is 0.05 μm.
As described above, the thickness is preferably 0.05 to 10 μm, and more preferably 0.1 to 5 μm, so that when the light incident from one end surface of the core material is transmitted through the core material, all of it is clad. Instead of being reflected on the inner peripheral surface of the material, part of it is effectively emitted through the clad material to the outside,
It has been found that the brightness of the inner surface of the light transmission tube is increased. On the other hand, if the average roughness is less than 0.05 μm, such effects cannot be sufficiently exhibited, and the object of the present invention cannot be achieved. If the average roughness exceeds 10 μm, the light emission luminance distribution in the length direction becomes extremely uneven, which may cause a disadvantage that only a part of the light incident side emits light. Therefore, the average roughness is 10 μm or less. It is preferable that

As described above, the method of setting the average roughness of the inner peripheral surface of the clad material to 0.05 μm is not particularly limited. For example, in the case of fluororesin, the extrusion conditions when extruding into a tube can be appropriately changed or the blasting can be performed. A method of applying treatment or the like is adopted.

The thickness of the clad material is not particularly limited, but is preferably about 0.1 to 5 mm.

As the core material 2 to be filled in the hollow portion of the clad material 1, a solid, liquid or fluid transparent material having a refractive index higher than that of the clad material is used.

In this case, as the solid transparent material, acrylic resins and methacrylic resins are preferably used. For example, alkyl acrylates such as methyl acrylate and methyl methacrylate, homopolymers and copolymers of alkyl methacrylates, copolymers of these monomers and the like. Other acrylates, capable of obtaining transparent polymers,
The thing which copolymerized the methacrylate etc. can be mentioned.

Specific examples of the liquid or fluid transparent material 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 paraffin, halogenated hydrocarbons such as trifluorochloroethylene oil, phosphoric acid esters such as tris (chloroethyl) phosphate and trioctylphosphate, polymer solutions prepared by diluting the polymer with an appropriate solvent. Is mentioned. These may be used alone or as a blend of two or more.

The sealing plug 3 can be used even if the core material 2 is solid, but it is necessary especially when the core material 2 is liquid or fluid. In this case, when acting as a window material for light, it is necessary that the material forming the sealing plug 3 is transparent, and specific examples of the material of the sealing plug 3 include quartz glass and multi-component glass. , Sapphire, inorganic glass such as 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, polyimide,
Examples include organic glass and plastic transparent materials such as polyethylene terephthalate, diallyl phthalate, fluororesins, polyester carbonates and silicone resins. Among these, quartz glass, Pyrex glass,
Inorganic glass such as multi-component glass is excellent not only in transparency but also in heat resistance and is chemically stable. Therefore, the core material 2 in contact with the end face 3a and the gas and moisture in contact with the end face 3b are used. It does not chemically react with either, and can provide excellent performance in the long term.

If transparency is not required, metal or ceramics can be used.

The optical transmission tube of the present invention is not particularly limited, but usually the outer diameter of the clad material is 3 to 1.
It can be formed to have a length of about 10 mm and a length of about 1 to 100 m.

[0019]

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] An inner diameter of 12 mm and an outer diameter of 14 obtained by extruding PFA (n = 1.35) with a wall thickness of 1 mm.
mm, length 5 m, average roughness (Ra) of the inner peripheral surface is about 0.
After filling a 6 μm tube (cladding material) with trioctyl phosphate (core material), both ends were sealed with quartz rods to obtain an optical transmission tube.

[Comparative Example] The tube (cladding material) has a wall thickness of 0.5 mm, and the inner peripheral surface has an average roughness (Ra) of about 0.03.
An optical transmission tube similar to that of the example except that the thickness was set to μm was obtained.

Next, light (metal halide lamp, 150 W) was incident from one end face of the obtained light transmission tube, and the brightness at a point 2 m from the one end face was measured. The brightness was measured at a position about 1 m away from the tube using a brightness meter (CS-100) manufactured by Olympus. The results are shown in Table 1.

[0023]

[Table 1]

From the above results, it was confirmed that the optical transmission tube of the present invention has a high hardness on the peripheral surface.

[0025]

According to the present invention, it is possible to obtain an optical transmission tube which has a high peripheral brightness and can be safely used even in an environment such as underwater.

[Brief description of drawings]

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

[Explanation of symbols]

 1 clad material 1a inner peripheral surface 2 core material

Claims (1)

[Claims] 1. An optical transmission tube comprising a transparent core material and a transparent tubular clad material having a refractive index lower than that of the core material, wherein the average roughness of the inner peripheral surface of the clad material is 0.05 μm.
An optical transmission tube formed as described above.