JPS61245110A - Plastic optical fiber - Google Patents

Abstract

PURPOSE:To obtain the titled fiber having a stability which pass the UL standard of USA, by constituting a core composed of a polycarbonate resin having prescribed characteristics and a clad composed of a silicon resin. CONSTITUTION:The titled fiber comprises the core 3 composed of the polycarbonate resin having a number average molecular weight (n)+(1.2-2.1)X10<4>, and the clad 4 composed of a component selected from a silicon resin, a silicone acrylate resin, an urethane acrylate resin, a nylon resin and a poly-4-methyl- pentene-1,and a coating material 5 composed of a polyolefin vinyl chloride copolymer. So that, the resin constituting the core 3 has the glass transition point of 140 deg.C, and the resin constituting the clad 4 has the glass transition point of 140 deg.C. As the coating material 5 covered on the surface of the titled fiber has >=150 deg.C the heat resisting temp., the titled fiber may be used at the usable temp. range of the optical fiber, and does not lose the transparency, and does not deform, even if contacting it with a hot water of 100 deg.C.

Description

[Detailed Description of the Invention] [Summary] Conventional plastic optical fibers use polystyrene resin (Pst) or polymethyl methacrylate resin (PMMA) as the core material, but both have 100%
The present invention makes it possible to construct a plastic optical fiber that can be used in an atmosphere of 100° C. or higher using a material with a high glass transition point.

[Industrial application field]

The present invention relates to an optical fiber for transmitting optical signals, and more particularly to a plastic optical fiber with excellent heat resistance.

Recently, inexpensive and lightweight plastic optical fibers have been used in place of conventional glass optical fibers in forming optical transmission networks that connect terminals located relatively close to each other.

However, the plastic that makes up the optical fiber crystallizes at temperatures near the glass transition point and its light transmittance decreases, so it cannot be used in areas where the temperature is higher than the glass transition point. For example, plastic optical fibers made of polystyrene resin or polymethyl methacrylate resin whose glass transition point is 100°C or lower cannot be used in a high-temperature atmosphere of 100°C or higher.

Furthermore, if the materials constituting the plastic optical fiber contain flammable materials, there is a problem that their use is regulated by standards that guarantee safety and that they cannot be used in atmospheres where there is a possibility of ignition.

For example, in electronic automobiles, optical fibers are installed in the engine room for transmitting optical signals, but the above-mentioned plastic optical fibers cannot be used because they have problems in terms of heat resistance and flame retardancy.

Therefore, it is desired to develop a plastic optical fiber that can be used even in a high-temperature atmosphere where the glass transition point is high<100° C. or higher and is made of a flame-retardant material.

[Conventional technology]

FIG. 4 is a cross-sectional perspective view showing a conventional plastic optical fiber.

In the figure, the optical fiber has a core (core wire) as shown in Figure 4.
1 and cladding CM>2, and the refractive index of light of the material forming core 1 (core material) is higher than that of the material forming cladding 2 (cladding material). They are combined to make them larger.

Conventional plastic optical fibers use polystyrene resin or polymethyl methacrylate resin as the core material, and polyvinylidene fluoride copolymer resin as the cladding material.

[Problem that the invention seeks to solve]

However, the glass transition point of polystyrene resin is about 70°C, and that of polymethyl methacrylate resin is about 10°C.
For example, polymethyl methacrylate resin is 5I! As shown in the temperature characteristic diagram of 1, the light transmittance rapidly decreases from 90°C. Therefore, it cannot be used for optical signal transmission in parts that may come into contact with boiling water, such as in certain food factories or in the engine compartment of automobiles.
In addition, polymethyl methacrylate resin is a flammable resin, and there is a problem in that it does not meet standards that guarantee safety, such as the UL standards of the United States.

[Means for solving problems]

FIG. 1 is a cross-sectional perspective view showing a plastic optical fiber according to the present invention.

The above problem is that the number average molecular weight is n-1,2~2.1×10
A core 3 made of polycarbonate resin 4, a cladding 4 made of any one of silicone resin, silicone acrylate resin, urethane acrylate resin, nylon resin, poly-4-methyl-pentene-1, and polyolefin-vinyl chloride. This problem is solved by the plastic optical fiber of the present invention, which comprises a coating 5 made of a copolymer.

[Effect]

Number average molecular weight fl-” 1.2 to 2.1× constituting the core
The glass transition point of the polycarbonate resin No. 104 is <140°C or higher, as shown in the temperature characteristics in Figure 2, and the glass transition point of the silicone resin, silicone acrylate resin, urethane acrylate resin, nylon resin, etc. constituting the cladding is The temperature is also 140°C or higher. Also poly
Although the glass transition point of 4-methyl-pentene-1 is about 25°C, it has a high melting point of 250°C or higher (in the lower temperature range, it can be used satisfactorily as a crund material).

Furthermore, the heat resistance temperature of the polyolefin-vinyl chloride copolymer that covers the surface of the plastic optical fiber is 150°C.
℃ or higher, and is a coating material that can withstand the temperature range in which plastic optical fibers are used. - Therefore, plastic optical fibers made of the above materials can be used satisfactorily in high-temperature environments of 140°C or lower, and will not devitrify or deform even if they come into contact with boiling water (100°C), for example. Never.

In addition, all of the above constituent materials are flame-retardant resins, and plastic optical fibers made of such materials can meet standards that guarantee safety, and are suitable for optical signal transmission in potentially flammable atmospheres. It can be used as

〔Example〕

Examples of the present invention will be described in detail below.

In order to construct an optical fiber, the refractive index of light of the core material must be greater than that of the cladding material. Under these conditions, the number average molecular weight of the core material is n-1, 2-2. The refractive index of the polycarbonate resin (for example, poly-4,4''-dihydroxydiphenyl-2,2-propane carbonate) of I x 10' is 1.5
86, and the refractive index of the cladding material is 1 for silicone resin.
．． 51, silicone acrylate resin and urethane acrylate resin are 1.45 to 1.50. 1.54 for nylon resin, 1.46 for poly-4-methyl-pentene-1
In both cases, the optical fiber can be constructed smaller than the core material.

For example, the plastic optical fiber of this example, which is composed of a core 3 with a diameter of 1 mm made of the above-mentioned core material and a cladding 4 made of silicone resin, has a light transmission loss rate of 3
As shown in the optical transmission loss rate characteristic in the figure (5 dB/M or less, the optical transmission loss rate is 2 to 3 dB/H for conventional plastic optical fibers whose core materials are polystyrene resin or polymethyl methacrylate resin). Although it is somewhat large, it is small enough to be used as a short-distance plastic optical fiber.

Moreover, the plastic optical fiber shown in this example has 14
It can be used satisfactorily in a high-temperature atmosphere of 0° C. or lower, can meet standards that guarantee safety, and can be used for optical signal transmission in an atmosphere that may be flammable.

〔Effect of the invention〕

As mentioned above, according to the present invention, the glass transition point is high at 100°C.
It is possible to provide a plastic optical fiber that can be used even in a high-temperature atmosphere, and is made of a flame-retardant material.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional perspective view showing a plastic optical fiber according to the present invention, and FIG. 2 is a temperature characteristic diagram of this embodiment. FIG. 3 is a light transmission loss rate characteristic diagram of this embodiment, FIG. 4 is a cross-sectional perspective view showing a conventional example, and FIG. 5 is a temperature characteristic diagram of polymethyl methacrylate resin. In the figure, 3 represents the core, 4 represents the cladding, and 5 represents the coating. 9r quantum nuclear application θ blade 1. Meat [Character 1 Gender Q] Vines 2 Tsukasa 0 7X/θ4 2xlO' 3xlO
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Claims (2)

[Claims] (1) Core (3) made of polycarbonate resin with number average molecular weight n = 1.2 to 2.1 x 10^4, silicone resin, silicone acrylate resin, urethane acrylate resin, nylon resin, poly-4-methyl- Cladding consisting of any one of Penten-1 (
4) A plastic optical fiber comprising: (2) A plastic optical fiber according to claim 1, the surface of which is covered with a coating (5) made of a polyolefin-vinyl chloride copolymer.