JPH05341125A - Side surface light emitting cable and structure thereof - Google Patents

Abstract

PURPOSE:To obtain a side surface light emitting body having excellent flexibility without unevenness of emission by coating one plastic optical fiber of a specified diameter, which has the sufficient light emitting quantity, with a diffusion layer at a specified thickness. CONSTITUTION:The periphery of one plastic optical fiber, which consists of a core 1 and a sheath 2 and which has a diameter at 1m or more, is coated with a diffusion layer 3 made of the semitransparent resin having the light diffusing property at 0.1mm or more of thickness. As the resin for the sheath 2 of the plastic optical fiber, the crystalline milky resin composed mainly of vinylidene phlorydro at 98-100% and having a melting point at 150 deg.C or more is desirable. As the resin for the core 1, polymethyl methacrylate resin, which includes 0.001ppm-50ppm of the spherical silicon resin at 1-3mum of diameter, is desirable. Furthermore, a plastic optical fiber having the heat resistance at 120 deg.C or more is desirably connected to the end surface of the cable, to which the light enters, at 15cm or less.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a side-emission fiber suitable for illumination, in which light incident on the end face of the fiber is leaked from the side face of the fiber to show the shape or existence of an object or to the destination. It is also used for indicating various directions and other decorations.

[0002]

2. Description of the Related Art As a method of emitting light linearly or in a plane over a relatively long distance, there are many side emission techniques using a plastic optical fiber. These techniques include mechanically scratching the interface between the core and the sheath of the plastic optical fiber or by partially dissolving it with a solvent, or by leaking the light by bending the plastic optical fiber. Method, a plastic optical fiber woven fabric, a planar light emitting device in which a semi-transparent light scattering film layer is adhered to one side of the woven fabric, and a plastic optical fiber bare wire bundled into a transparent hose. .. When it is desired to widen the light emitting surface for emitting light, there is usually a method of arranging a plurality of plastic optical fibers on a plane, or by arranging them in different thicknesses and widths to emit light from the side. It is described in the official gazette.

[0003]

Among the side surface light emitters according to the prior art, the one in which the cladding of the plastic optical fiber is damaged has a decrease in mechanical strength of the plastic optical fiber and a uniform damage. Because it is difficult to
The problem is that the light emission becomes uneven and lacks elegance. When a plastic optical fiber is bent or made into a woven fabric, the light shines strongly at the bent part, so it has a special taste, so depending on the taste of the user, that taste may be used. is there. However, its use is limited because it is not a light emitter that emits uniform light. When a plurality of commercially available plastic optical fibers are inserted into a transparent plastic hose, the plastic optical fibers are complicatedly overlapped and twisted in the hose, and uneven light emission occurs. Furthermore, even if the light is emitted in a straight line or a curved line, the bulky bundle makes wiring difficult and smooth expression is difficult.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in order to solve the above-mentioned problems, and coat a plastic optical fiber having a constant core / sheath structure with a semitransparent resin having a light diffusing property. To emit a uniform light,
A side light emitting cable having good workability was obtained. That is, 1) A diffusion layer formed by coating a bare plastic optical fiber having a core-sheath structure with a diameter of 1 mm or more with a semi-transparent resin having a light diffusing property to a thickness of 0.1 mm or more Side-lighting cable covered with.

2) 98 to 100 mol% of vinylidene fluoride as a sheath resin of a plastic optical fiber,
A crystalline cloudy resin having a melting point of 150 ° C. or higher.
Side emitting cable. 3) The core resin of the plastic optical fiber is polymethylmethacrylate resin (PMMA resin), and 0.001% of spherical silicon resin of 1 to 3 μm is contained in the core resin.
The cable for side light emission according to claim 1, wherein the cable contains ppm to 50 ppm.

4) The core resin of the plastic optical fiber is polymethylmethacrylate resin (PMMA resin). The plastic optical fiber having heat resistance of 120 ° C. or higher at the light incident end face portion of the side surface light emitting cable. A side-emitting structure in which is connected within 15 cm or less. The present invention will be described in detail below.

The present invention has a diameter of 1 m consisting of a core and a sheath.
A side light emitting cable in which a bare plastic optical fiber having a length of m or more is covered with a diffusion layer formed by coating a semi-transparent resin having a light diffusing property to a thickness of 0.1 mm or more. The cable of the present invention uses one relatively thick bare plastic optical fiber bare wire as a light emitter, and the cable is a substantially rod-shaped, semi-transparent plastic optical fiber with a substantially uniform structure at any part of the entire circumference. Even if a fiber cable is used to emit light from the side surface with little unevenness, and when wiring to express light emission, the cable bends in a smooth curve as if it were a flexible curve ruler, so elegant light emission is possible. The thickness of the bare wire of the plastic optical fiber is usually about 1 mm to 5 mm in diameter. If it is less than 1 mm, the amount of light emission is insufficient. 1.5 mm to 3 mm to obtain particularly effective brightness
A bare wire is more preferable. Brightness increases with increasing thickness, but rigidity increases, so it is preferable to select the thickness according to the application. It is necessary to form a diffusion layer by coating the outside of the bare plastic optical fiber with a translucent resin having a light diffusing property to a thickness of 0.1 mm or more. This diffusion layer may be in close contact with the plastic optical fiber, or there may be a space between the diffusion layer and the bare plastic optical fiber. Especially when there is a space, the light emission becomes soft.

In order to obtain the diffusion layer, a thick plastic optical fiber is melted in an extruder through a crosshead die like an ordinary wire coating in a hose made of a light diffusion resin. There is a method of coating. The light-diffusing resin is polyethylene, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polyvinyl chloride, thermoplastic polyurethane, styrene / butadiene block copolymer elastomer, or its copolymer. Hydrogenated most of the double bonds of the polymer, vinylidene fluoride / hexafluoropropene copolymer, vinylidene fluoride / hexafluoropropene / tetrafluoroethylene copolymer, vinylidene fluoride / chlorotrifluoroethylene copolymer , Silicone rubber and the like, but not limited to these. These resins preferably have a Shore A hardness of 92 or less, and more preferably 70 or less because the flexibility is improved. Most of the above-mentioned resins have a light transmissive property because the resin itself is semi-transparent due to its crystallinity and the like, but it is more positively active in these resins, and an inorganic diffusing material having a particle size of about 1 μm to 5 μm, For example, add barium sulfate, titanium oxide, calcium carbonate, silica, alumina, talc,
Alternatively, it is preferable to use a spherical silicone resin or a resin having a different refractive index and not compatible with each other so as to use a resin having a small amount of light transmission but a large amount of light transmission. The light diffusing layer diffuses the light leaking from the bare plastic optical fiber to form a more even and smooth light emitting body. If desired, the diffusion layer may be colored blue or the like.

The thickness of the diffusion layer can be determined mainly by the requirement for the thickness of the light emitting body of the side light emitting cable and the ease of handling the cable. In particular, in order to make the cable easy to handle, it is sufficient to coat the flexible resin thickly. The thickness of the diffusion layer needs to be at least 0.1 mm in order to maintain mechanical strength and to diffuse the light of the internal plastic optical fiber bare wire softly. Although the upper limit of the thickness is not particularly specified, it is usually about 2 mm. The turbidity and the thickness of this diffusion layer must be considered synergistically. To reduce the thickness, the turbidity of the resin should be thick, and to increase the thickness, the turbidity of the resin should be thin. .. To give a preferable requirement for this diffusion layer for that purpose, it is advisable to confirm in advance the sheet molded to the thickness of the diffusion layer to be actually used by the following evaluation method.

That is, the sample sheet is irradiated with a laser beam (for example, a He-Ne laser beam of 2 mm) at a right angle,
It is preferable to measure the intensity of the light emitted from the back side with respect to the angle with respect to the incident optical axis, and to select the half-value width of the spectrum to be about 5 degrees to 40 degrees, more preferably 10 degrees to 30 degrees. More preferred is the uniformity and brightness of light.

As a bare wire of a plastic optical fiber, a low-loss fiber as used in ordinary optical communication can be used. However, such a fiber has little sheath turbidity and happens to be on the outside of the sheath. Bright spots tend to occur due to adhered foreign matter. Therefore, in order to effectively perform more uniform side surface light emission, it is preferable that the sheath be uniformly cloudy because glittering light is suppressed. For that purpose, it is preferable to use a highly crystalline sheath resin in which the sheath of the core / sheath fiber occupies 98% to 100 mol% of vinylidene fluoride. Such a resin has a melting point of about 150 to 170 ° C., and when such a resin has a PMMA resin core,
It is preferable because it is well compatible with the core resin and keeps the mechanical strength of the plastic optical fiber strong. The melt flow index of the resin used for this sheath is ASTM-123
8; temperature 230 ° C., load 3.8 kg, die inner diameter 2.
It is preferably 1 g / 10 minutes or more, more preferably 10 g / 10 minutes to 50 g / 1 as measured by 0955 mm.
0 minutes.

Regarding the transmission loss of the side light emitting fiber, more efficient light emission can be achieved by adjusting the transmission loss of the plastic optical fiber according to the intended light emission length. In this method, various transmission losses can be obtained by adding light diffusing impurities to the PMMA resin of the core of the core / sheath fiber, but impurities that increase absorption loss must not be added. Since a scattering substance having a wavelength smaller than the wavelength has a large wavelength dependency and scattered light is colored red in the longitudinal direction, it is preferable to disperse uniform fine particles of about 1 to 3 μm as the scattering substance. As a result, the transmission loss of the plastic optical fiber is 0.1 dB / m when measured at a wavelength of 570 nm.
To about 10 dB / m.

In order to effectively scatter light as side emission, a plastic optical fiber whose transmission loss due to scattering loss is controlled is preferable. For side emission of 20 m or more, about 0.2 dB / m at 570 nm, A plastic optical fiber of about 0.5 dB / m for 10 m, 0.7 dB / m for 5 m, 1 dB / m for 2 m, and 10 dB / m for 0.5 m is suitable. Of course, when a plastic optical fiber with a lower loss than the above value is used, the total amount of light emission decreases, but instead, the degree to which the emission intensity is attenuated in the longitudinal direction is small, so it is optimally selected according to the application. You can choose the right one. As described above, as the scattering substance having a small absorption loss, a large scattering loss, and a small wavelength dependence, particularly preferable are granular particles of silicon-based resin or silica, in which particles having a diameter of about 1 μm to 3 μm are uniform. Is preferably used. In particular, silicone resin is preferable because it does not wear the extruder.

The method of using the side-emission optical fiber cable of the present invention is to cause light to be incident on one end surface or both end surfaces of the cable, to cause light to leak from the side surface in the longitudinal direction of the optical fiber, and to make the diffusion layer emit light. Is. The optical fiber cable should be wired in the shape you want to display, and in some cases black tape may be used to display characters, the shape of objects, or the bottom course of a swimming pool by partially shielding it. Can be done.

Since a high-temperature light source is used at the end portion of these side-emitting optical fiber cables, if PM
When the heat resistance of the MA resin cable is insufficient, a heat insulating spacer having a length of 15 cm or less, preferably 3 to 6 cm, made of a polycarbonate resin plastic optical fiber or another heat resistant plastic optical fiber is used. It is possible to connect between the side emitting optical fiber cable and the stainless tube. With this length, the loss due to connection can be ignored.

The method of coating the diffusion layer according to the present invention is a method of coating a bare plastic plastic optical fiber with a molten resin with a crosshead die in the same manner as a normal wire coating.
The other is to prepare a hose in advance and insert a plastic optical fiber into it.

[0017]

EXAMPLES Hereinafter, the present invention will be described with reference to examples in order to further clarify the present invention, but the scope of the present invention is not limited to these examples.

[0018]

Example 1 As a PMMA resin, pellets having a weight average molecular weight of 100,000 and containing 99.5% of MMA (methyl methacrylate) and 0.5% by weight of MA (methyl acrylate) were used. The pellets were processed as follows in a clean room. The number of fine particles in the PMMA resin pellets was measured with a fine particle measuring instrument: High Acryco Model 4100. The number of fine particles is 0.5-2 μm and 800 pieces / g
Met. The pellets are put into a core extruder, while a vinylidene fluoride homopolymer as a sheath polymer,
Refractive index 1.42, melting point 170 ° C, melt index (ASTM-1238 temperature 230 ° C, weighted 3.8K
g, die inner diameter 2.0955 mm) was 20 g / 10 min. This sheath polymer was put into a sheath extruder, and the molten core polymer and sheath polymer were introduced into a composite spinning die to produce a core-sheath structure bare optical fiber at a temperature of 230 ° C. The bare wire had a diameter of 2.0 mm and a sheath thickness of 20 μm. The transmission loss of this plastic optical fiber was 0.3 dB at 570 nm when measured with a cutback at 11 m-1 m with an incident NA = 0.15.
Was / m. This plastic optical fiber has an inner diameter of 4.
5mm outer diameter 6mm, the diffusion degree of the diffusion layer, the light at each angle of the light emitted from the emission end when the sheet of 0.75mm thickness of the same material as the hose used for the diffusion layer is irradiated with helium neon laser light The power distribution was investigated. According to this, the full width at half maximum of the emitted light distribution was 21.6 degrees. The emission distribution spectrum is shown in FIG.

Now, 10 m of the side surface emitting plastic optical fiber cable was connected to a halogen lamp of 50 W. This lamp was equipped with an infrared cut filter and a fan for cooling the wind, and the end face was directly connected to the light source. Light emission from the side surface is not uneven,
Although the brightness gradually decreased over 10 m, it showed a sufficient illumination effect in the dark. The light emitted from the side was still pale at 10m.

[0020]

[Example 2] Example 2 was carried out except that the particulate resin Tospearl (trademark) 120 (average particle size 2 mμ refractive index 1.44) added to the PMMA resin used in Example 1 in an amount of about 1 ppm was used. A 2 mm plastic optical fiber was obtained in the same manner as in Example 1. This plastic optical fiber can barely transmit 2m of indoor light,
The transmission loss was 570 nm and was 8 dB / m. 1.0 m of this fiber was inserted into the silicon hose used in Example 1, and the light of a halogen lamp of 50 W was made to enter. By the visual observation, the emission from the white side was strongly observed up to about 0.5 m, but the intensity of the side emission was significantly attenuated at the position of 1 m.

[0021]

Example 3 As the PMMA resin, pellets having a weight average molecular weight of 100,000 and containing 99.5% of MMA (methyl methacrylate) and 0.5% by weight of MA (methyl acrylate) were used. The pellets were processed as follows in a clean room. When the number of fine particles in the PMMA resin pellet was measured by a fine particle measuring instrument, Hiacureco Model 4100, the number of fine particles was 0.5-2 μm and was 2000.
It was K / g. The same as in Example 1 below, the diameter is 2 mm.
I got a plastic optical fiber. This transmission loss is 57
It was 0.7 dB / m at 0 nm.

SHOR is added to this plastic optical fiber.
It was coated with translucent PVC resin having an EA hardness of 60 to 4 mm. Spread this diffusion layer into a sheet and add He-Ne
A razor ray was applied to measure the radiant intensity according to the angle of the radiant light on the back side of the sheet, and the half-width was determined to be 15 degrees. In this cable, the plastic optical fiber and the diffusion layer are almost intimately coated. 50 on this cable
When it was irradiated with light from a W halogen lamp, it emitted a bluish milky-white smooth light emission with no bright spots and no unevenness over 5 m.

It was confirmed that this cable can be freely bent with almost no resistance at a bending radius of 25 mm.

[0024]

Example 4 As a PMMA resin, 99.5% of MMA (methyl methacrylate) produced by a continuous polymerization method,
Molecular weight 1 consisting of MA (methyl acrylate) 0.5%
0,000 of the resin was directly introduced into the composite spinning die from the devolatilizing extruder, and the polyvinylidene fluoride of Example 1 was used as the sheath resin. The transmission loss of this plastic optical fiber with a diameter of 2.0 mm was 0.1 dB / m at 570 nm. A 50 W halogen lamp was passed through a cable obtained by coating the fiber with the same PVC resin as in Example 3 to a thickness of 4 mm.
Side emission was performed over a length of m. As a result, 3
Although there was a gradual attenuation over 0 m, a milky white luminescence was observed at a point of 30 m.

[0025]

[Embodiment 5] As a heat-resistant measure for the end portion of the cable of Embodiment 3, a 125 ° C. heat-resistant plastic optical fiber having a polycarbonate resin core and a bare wire of 2 mm in diameter is heat-resistant coated with polypropylene resin to 4 mm. A plastic optical fiber cable of 5 cm, an inner diameter of 4.1 mm, an outer diameter of 4.5 mm, and a length of 8 cm of a stainless steel pipe were prepared, and the heat-resistant plastic optical fiber cable of 5 cm was used. The light emitting cable (3 cm) was inserted into each stainless steel pipe, and both ends of the stainless steel pipe were clamped and fixed.

FIG. 4 shows a structural diagram. The side light emitting structure having this structure was used to connect to a 50 W halogen lamp.
I approached the distance where the tip temperature rose to 115 ° C,
The temperature at the tip of the PMMA fiber was only about 80 ° C.

[0027]

As described above, by coating one plastic optical fiber having a sufficient amount of light emission with a diffusion layer, it is possible to provide a side light emitting body having no unevenness and a high flexibility.

[Brief description of drawings]

FIG. 1 is a sectional view of a plastic optical fiber structure of the present invention (diffusion layer adhesion type).

FIG. 2 is a sectional view of a plastic optical fiber structure of the present invention (diffusion layer non-adhesion type).

FIG. 3 is a radiant intensity distribution according to an angle of radiated light when the diffuser layer is irradiated with laser light.

FIG. 4 is a side view light emitting structure and end portion of the present invention.

[Explanation of symbols]

1, core 2, sheath 3, diffusion layer 4, air layer 5, side light emitting cable 6, heat insulating spacer 7 made of heat-resistant plastic optical fiber cable, stainless tube 8, caulking fixing part

Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location G02B 6/44 321 7036-2K

Claims (4)

[Claims] 1. A diffusion formed by coating a bare plastic optical fiber having a core-sheath structure with a diameter of 1 mm or more with a light-diffusing semitransparent resin to a thickness of 0.1 mm or more. Side emitting cable covered with layers. 2. The side light emitting cable according to claim 1, which is a crystalline cloudy resin having a vinylidene fluoride content of 98 to 100 mol% as a sheath resin of a plastic optical fiber and a melting point of 150 ° C. or higher. 3. The plastic optical fiber core resin is a polymethylmethacrylate resin (PMMA resin), and the core resin contains 0.001 ppm to 50 ppm of a spherical spherical silicon resin of 1 to 3 μm. Side emitting cable. 4. The side surface of the cable for side light emission according to claim 1, wherein the core resin of the plastic optical fiber is polymethylmethacrylate resin (PMMA resin).
A side light emitting structure in which a plastic optical fiber having a heat resistance of 20 ° C. or higher is connected within 15 cm.