JPS62192712A - Plastic optical cable - Google Patents

Abstract

PURPOSE:To obtain the titled fiber having a heat-resistance until near the glass transition point of a thermoplastic resin, and having a less tendency for suffering a mechanical injury by coating an org. optical fiber with a UV curable type resin, and by coating the obtd. optical fiber with a specific resin. CONSTITUTION:The titled cable is constituted of a core component 1 of the org. optical fiber, a shell component 2 of the org. optical fiber, the 1st coating resin layer 3 composed of the UV curable resin, and the 2nd coating resin layer 4. The characteristic of the titled cable lies in providing the 1st coating resin layer 3 composed of the UV curable resin, and the 2nd coating resin layer 4 composed of the resin having a larger glass transition point or a Vicat softening point than that of the core component polymer constituting the org. optical fiber, in order, as the resin layer coated on the org. optical fiber. Thus, the cable having the heat-resistance until the glass transition point of the core component 1 and having a sufficient resisting property against the mechanical injuring and a lateral pressure is obtd. The titled cable having an improved handling and practical properties is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a highly practical plastic optical cable that prevents mechanical damage.

[Conventional technology]

Conventionally, optical fibers made from organic polymers (hereinafter referred to as organic optical fibers) have the disadvantage that they are more easily damaged thermally and mechanically than glass-based optical fibers, and have not been used in practical applications such as optical cables. When used in organic optical fibers, the organic optical fibers are usually coated with a resin to prevent damage.

According to JP-A No. 60-194413, in order to improve the heat resistance, especially the heat and humidity resistance, of the organic optical fiber, the strands of the organic optical fiber were coated with an ultraviolet curing resin having a Shore hardness of 65 or more. Thereafter, a strand of organic optical fiber obtained by curing the resin by irradiating with ultraviolet rays is described.

This organic optical fiber strand has the effect of improving the disadvantage that polymethyl methacrylate, which is the core component of the fiber, shrinks when heated, increasing optical transmission loss as an optical fiber. It does not have enough heat resistance to prevent a decrease in light transmission when the core component of the optical fiber is heated to near the glass transition point.

[Problem to be solved by the invention]

The purpose of the present invention is to provide an organic optical fiber with heat resistance, particularly heat resistance up to near the glass transition point of the thermoplastic resin that constitutes the core component of the fiber, and optical transmission properties that are resistant to mechanical damage. To provide superior plastic optical cables.

[Means for solving problems]

The object of the present invention is to coat a linear optical fiber with an ultraviolet curable resin and coat it with an organic optical fiber.

This can be achieved by using a plastic optical cable coated with a resin having a Vicat softening point higher than the glass transition temperature of the core component polymer constituting the fiber.

The organic optical fiber constituting the plastic optical cable of the present invention may be any known organic optical fiber, and is not particularly limited. As a representative example of an organic optical fiber, the core component polymer may be polymethyl methacrylate. Examples include organic optical fibers in which the sheath component polymer is a polymer selected from vinylidene fluoride and tetrafluoroethylene copolymers and fluorinated acrylate copolymers.

The figure shows a sectional view of the plastic optical cable according to the present invention.

1 is a core component of the organic optical fiber, 2 is a sheath component of the organic optical fiber, 3 is a primary coating resin layer made of an ultraviolet curable resin, and 4 is a secondary coating resin layer.

The feature of the present invention is that a primary coating resin layer made of an ultraviolet curable resin is provided as a resin layer covering the top of these organic optical fibers, and the glass transition is larger than that of the core component polymer constituting the organic optical fibers. The main point is that a resin having a Vicat softening point or a Vicat softening point is provided as a secondary coating resin layer.

Examples of the ultraviolet curable resin used in the present invention include unsaturated polyester-based resins having a radically polymerizable double bond in the main chain or side chain of the polymer chain, epoxy acrylate-based resins, urethane acrylate-based resins, polyether acrylate-based resins,
List of resins that are cured by irradiating ultraviolet rays to resin compositions containing as main components polyester acrylate, acrylic, unsaturated polybutadiene, melamine acrylate resins, long side chain vinyl compounds, etc. and photopolymerization initiators. I can do it.

Preferably, the UV-curable resin has a higher refractive index than the refractive index of the sheath component polymer constituting the organic optical fiber, for example, when the core component polymer is polymethyl methacrylate, the resin does not contain a halogenated component. Any of the various resins mentioned above may be used.

That is, if the refractive index of the ultraviolet curable resin is lower than that of the core component polymer, there is a disadvantage that the transmission band may be reduced due to the re-incidence of leaked light, which is not preferable.

Here, the thickness of the primary coating resin layer made of ultraviolet curable resin is preferably within the range of 5 to 150 μm, preferably 10 to 10,071 μm; outside this range, the thermal behavior of the organic optical fiber will be substantially affected. It is undesirable because it cannot be regulated and heat resistance cannot be achieved.

In addition, as a photopolymerization initiator for the above ultraviolet curable resin,
There are benzoin-based, azo-based, diphenyl sulfide-based, organic peroxide-based, FM dye-based, iron/phthalocyanine-based, etc. UV sources include fluorescent chemical lamps, high-pressure mercury lamps, etc.

Next, examples of the resin forming the secondary coating resin layer of the plastic optical cable of the present invention include high-density polyethylene, polyester elastomer, ethylene-propylene copolymer,
Polypropylene, Robylene, polycarbonate, polybutylene terephthalate, etc. are used, and the resin forming this secondary coating resin layer must have a glass transition temperature or Vicat softening point higher than that of the core component polymer that makes up the organic optical fiber. .

In other words, if the glass transition temperature or Vicat softening point of the resin forming this secondary coating resin layer is lower than that of the core component polymer of the organic optical fiber, the plastic optical cable may be Even if heated to temperatures close to that temperature, it becomes difficult to provide heat resistance that maintains the optical transmission properties of organic optical fibers, and the properties to withstand the pressure (lateral pressure) of plastic optical cables become insufficient, which is undesirable. .

The thickness of this secondary coating resin layer is not particularly limited, but preferably the sum of the thicknesses of the primary and secondary coating resin layers is in the range of 250 to 1000μ. Good.

The method for manufacturing such a plastic optical cable of the present invention includes coating an organic optical fiber with the ultraviolet curable resin composition, curing the coating resin by irradiating it with ultraviolet rays,
Thereafter, a known method for coating the secondary coating resin is applied.

More specifically, after applying a predetermined N of the ultraviolet curable resin composition to the organic optical fiber, the coated fiber is run at a predetermined speed inside a mercury lamp in which a plurality of fibers are arranged on the circumference. A method is employed in which an ultraviolet curable resin applied around the component polymer is cured by ultraviolet rays.

The thus obtained plastic optical cable of the present invention can be further coated with a resin to impart resistance to external mechanical and thermal damage to the plastic optical cable.

〔Effect of the invention〕

According to the present invention, the following excellent technical effects are achieved.

(11) It is possible to provide a plastic optical cable that has heat resistance close to the glass transition point of the core component constituting the organic optical fiber, greatly improving its practicality.

(2) Since it exhibits sufficient resistance not only to mechanical damage but also to lateral pressure, it greatly improves the handling and practicality of the cable.

etc.

〔Example〕

EXAMPLES Hereinafter, the plastic optical cable of the present invention and its effects will be explained in more detail with reference to Examples.

Note that the glass transition point, Vicat softening point, heat resistance, lateral pressure resistance, and optical transmission characteristics are values measured by the following measuring method.

Glass transition point: Based on DSC method.

Vikasoto Softening Point: According to JIS K7206. However, the load is 1000 g.

Heat resistance: A 30m optical cable is placed in a skein shape in a hot air thermostat, and 660nm+ light emitting diode light is input from one end pulled out outside the tank, and the other end is connected to an optical power meter to measure the light before heating. Changes in optical power were measured using power as a reference. Note that the light-emitting diode autopower change was corrected by reference power check.

Lateral Pressure Resistance The central part of a 3 m long optical cable, in which 660 nn+ light emitting diode light is input from one end and the other end is connected to an optical power meter, is placed on a steel plate, a 5 cm long steel plate is placed on top of the optical cable, and a 150 kg A load was applied, and the change in optical power was measured based on the optical power when no load was applied.

Optical transmission characteristics: Based on the cutback method with a sample length of 50 m and a reference length of 2 m.

Example 1 A resin composition containing urethane acrylate as a main component was applied as an ultraviolet curable resin composition to an organic optical fiber having polymethyl methacrylate as a core component and a resin containing fluorinated acrylate as a main component as a sheath component. A primary coating resin layer having an ultraviolet curable resin layer having a thickness of 50 μm was formed.

After that, 550μ of ethylene/propylene copolymer resin was applied.
A secondary coating resin layer was formed by coating the plastic optical cable to a thickness of .

As a result of measuring the optical transmission characteristics, heat resistance, lateral pressure resistance, etc. of this plastic optical cable, optical transmission characteristics: 215 dB
/km (measurement wavelength 660nm) Heat resistance: 115℃
There was no change for 7 days.

Side pressure resistance: 0.1dB Met.

[Brief explanation of drawings]

The figure is a sectional view showing one embodiment of the plastic optical cable according to the present invention. (2) Core component of organic optical fiber, 2... Sheath component of organic optical fiber, 3... Primary coating resin layer, 4... Secondary coating resin layer.

Claims (2)

[Claims] (1) A plastic optical cable comprising an organic optical fiber coated with an ultraviolet curable resin and a resin having a Vicat softening point higher than the glass transition temperature of the core component polymer constituting the organic optical fiber. (2) The plastic optical cable according to claim 1, wherein the refractive index of the ultraviolet curable resin is greater than the refractive index of the sheath component polymer constituting the organic optical fiber.