JPS6057811A - Manufacture of plastic optical fiber cord - Google Patents

Abstract

PURPOSE:To reduce variations in optical waveguide loss value and to obtain stable transmission characteristics on various environmental conditions by coating a plastic optical fiber with a light-setting resin compound, and curing the resin compound below the glass transition point of the core component through reaction based upon irradiation with ultraviolet rays. CONSTITUTION:The plastic optical fiber is coated with the light-setting resin compound. This light-setting compound contains resin which reacts and sets below the glass dislocation temperature of the core component of the plastic optical fiber, preferably at <=80 deg. by ultraviolet-ray irradiation, or resin which reacts and sets below the glass transition temperature of the core component of the plastic optical fiber. The core component of the optical fiber deforms and also has thermal hysteresis above the glass dislocation temperature to decrease in characteristics easily. For example, the plastic optical fiber 7 having, for example, a 450mum fiber diameter is unwound from a drum 8 and coated by a resin coating device 9 with urethane acrylate resin which sets by ultraviolet-ray irradiation to about 100mum thickness the resin reacts and sets through an ultraviolet-ray irradiating device 1, and the fiber is taken up around a guide reel 10 by a take-up device 11. At this time, the internal temperature of the purging quartz pipe 5 in the ultraviolet-ray irradiating device 1 is set to 60 deg.C.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing a plastic optical fiber cord, and more particularly to a plastic ink optical fiber cord having stable transmission characteristics with small fluctuations in light guide loss under various environmental conditions. The present invention relates to a manufacturing method.

Conventionally, composite fibers have a concentric core-sheath structure in which the core is made of a highly transparent synthetic polymer such as polystyrene or polymethacrylate, and the sheath is made of a synthetic polymer with a lower refractive index than the core component. A plastic optical fiber is known in which the light incident on -αfii of the fiber is totally internally reflected along the length of the fiber and transmitted.

What should be considered when manufacturing this type of plastic optical fiber is to minimize factors that increase the attenuation of light due to absorption or scattering of the light when it is transmitted inside the optical fiber. That's true. Another thing to consider when handling optical fibers is to prevent TN scratches during use, and for this reason, the outside of the optical fiber is coated with an appropriate synthetic polymer to improve chemical resistance, weather resistance, etc. It is an optical fiber code that can be used as an optical fiber code.

In principle, such plastic coating can be performed using a normal wire coating device, and the coating materials include polyethylene, ethylene-vinyl acetate) 14Ji combination, ethylene-ethyl acrylate copolymer, and polyvinyl chloride. Synthetic polymers such as

When coating plastic optical fibers with these synthetic polymers, it is usually necessary to extrude them at an extrusion temperature of 20 to 180'C, but the heat during molding may impair the roundness of the plastic optical fibers. , by being pulled and stretched by the coating material, the scattering of light transmitted through the optical fiber increases and the attenuation of light may become stronger. Furthermore, thermal stress during coating remains in the optical fiber core material, resulting in significant fluctuations in light guiding properties over time under various environmental conditions.

In order to eliminate these drawbacks, the tension on the optical fiber during the coating process can be reduced by focusing the plastic optical fiber with a textile material made of a material that has a higher softening temperature than the coating material. However, even with such a method, it is not possible to block the heat during coating, and it is not possible to suppress fluctuations in the light guide characteristics over time.

The present invention has been made in view of the above points, and an object of the present invention is to provide a method for manufacturing a plastic optical fiber cord having stable transmission characteristics with small fluctuations in light guide loss value under various environmental conditions.

Therefore, the method for producing a plastic optical fiber cord according to the present invention involves coating a plasti-ink optical fiber with a photocurable resin composition, and then irradiating it with ultraviolet rays to achieve a temperature lower than the glass transition temperature of the core component of the plastic optical fiber. This method is characterized in that the resin composition is reacted and cured at a certain temperature.

According to the method for manufacturing a plastic optical fiber cord according to the present invention, when coating the optical fiber with a coating material, a liquid resin composition or a liquid or solid resin composition is used in a solvent without using an extrusion molding technique. Since the optical fiber is coated with a solution that is melted or dispersed and cured, it is possible to prevent damage to the optical fiber during use, improve chemical resistance and weather resistance, and make it possible to withstand various environmental conditions. There is an advantage in that it is possible to suppress fluctuations in light guiding characteristics over time.

The present invention will be explained in more detail.

According to the method for manufacturing a plastic optical fiber cord according to the present invention, first, a plastink optical fiber is coated with a photocurable resin composition.

The photocurable resin composition may be one that reacts and cures at a temperature lower than the glass transition temperature of the core component of the plasti-ink optical fiber, preferably 80° C. or lower, when irradiated with ultraviolet rays, or one that reacts and cures at a temperature below the glass transition temperature of the core component of the plasti-ink optical fiber. A composition is selected that includes a resin that reacts and cures at a temperature below the glass transition temperature.

This is because if the temperature is higher than the glass transition temperature, the core component of the optical fiber will be deformed and will be subject to thermal history, resulting in a tendency for properties to deteriorate. Considering the resin used in the plastic ink optical fiber, the temperature is generally preferably 80° C. or lower.

The resin composition that can be used in the present invention is preferably used in a liquid form in order to facilitate production.

In this case, a liquid resin composition or a resin composition obtained by dissolving or dispersing a liquid or solid resin composition in a solvent is used.

Specific examples of the resin components of the resin composition as described above include:
Examples include acrylic resins, urethane resins, epoxy resins, spiran resins, silicone resins, unsaturated polyester resins, alkyd resins, modified products thereof, and mixtures of two or more thereof.

Particularly, acrylic resins and modified products thereof, such as urethane acrylate, epoxy acrylate, silicone acrylate, polybutadiene acrylate, etc., are effective in the present invention. These acrylates can be used in addition to monofunctional acrylates or polyfunctional acrylates, if necessary, in order to control the viscosity and mechanical properties after curing.

One or more additives such as a photopolymerization initiator, an antioxidant, an ultraviolet absorber, a reinforcing material, a filler, a silane coupling agent, etc. can be added to the resin component as described above.

The above-mentioned photocurable resin composition has characteristics such as fast curing, no limit on pot life, and little influence of temperature. It has the advantage of not applying stress.

After coating an optical fiber with the photocurable resin composition as described above, irradiating it with ultraviolet rays using an ultraviolet irradiation device,
Reaction hardening. At this time, it is possible to use a constant temperature drying oven.

The present invention will be described in detail below, but it is clear that the examples described below are merely illustrative and do not limit the present invention.

In the following examples, an ultraviolet ray irradiation device 1 as shown in FIG. 1 was used for irradiating ultraviolet rays.

The ultraviolet irradiation device 1 includes a cooling exhaust vent 2 and a mercury lamp 3 with a rated power of 2 degrees and a lamp length of 25 as a light source. Furthermore, an elliptical reflection plate 4 is provided in the ultraviolet irradiation device I so that the optical fiber 7 can be uniformly irradiated with ultraviolet rays from the light source 3. In addition, a quartz tube 5 for purging is provided in order to prevent curing inhibition caused by oxygen, remove the influence of moisture, or reduce radiant heat from the ultraviolet lamp 3. is connected so that nitrogen gas can flow through it.

Example 1 The fiber diameter is 450 mm by the line as shown in FIG.
A plastic optical fiber huff with a thickness of 100 μm is pulled out from the drum 8 and coated with ultraviolet curable urethane acrylate resin (Desolite) with a film thickness of 100 μm using a resin coating device 9.
Apply 950XO30 (trade name: manufactured by Desoto),
It was reacted and cured using an ultraviolet irradiation device 1 and wound up using a guide reel 10 and a winding machine 11. At this time, the internal temperature of the purging quartz tube 5 in the ultraviolet irradiation device 1 is 60°C.
It was ℃.

The plastic optical fiber coating obtained in this way has sufficient strength and is placed in a thermostatic oven at 70°C for 1 to 3 hours.
After being allowed to stand for a week, the light guiding properties varied within 3%.

Example 2 In the same manner as in Example 1, an ultraviolet curable epoxy acrylate resin (Lipoxy R-8400A, trade name: Showa Kobunshi Co., Ltd.) was applied to a film thickness of 100 μm and cured.

The resulting plastic optical fiber coating was
After being left standing in a constant temperature and humidity chamber at 90% R11 for one week, the light guiding properties were measured, and as a result, the variation in the properties was within 5%.

Example 3 The fiber diameter is 500 mm by the line as shown in FIG.
A 150 μm thick film of UV-curable epoxy acrylate resin (Deso
lite 950x037 (trade name, manufactured by Desoto) was coated and reaction-cured using an ultraviolet irradiation device 1 and a constant temperature drying oven 12 set at 60'C.

The obtained plastic optical fiber was heated at 70°C and 90% R.
After being left in a constant temperature and humidity chamber for one week, the light guide characteristics varied within 3%.

Example 4 In the same manner as in Example 1, an ultraviolet curable butadiene acrylate resin (ZF-127 trade name, manufactured by Nippon Zeon Co., Ltd.) was applied to a thickness of 120 μm and cured.

The resulting plastic optical fiber coating was
The light guide characteristics were measured after being left in a constant temperature bath at .degree. C. for one week, and as a result, the fluctuation in characteristics was within 5%.

Comparative Example I Fluctuations in light guide properties after a commercial grade plastic ink optical fiber cord with a fiber diameter of 500 μm, polyethylene coating, and film thickness of 250 pm+ was left standing in a constant temperature and humidity chamber at 60° C. and 90% RH for one day. was 18%.

Comparative Example 2 Plastic optical fiber G3 with a fiber diameter of 450 μm A plastic optical fiber cord obtained by extrusion molding at 1352°C using polyethylene as the coating material was heated at 60°C.
After being allowed to stand in a constant temperature and humidity chamber of 90% R11 for one day, the light guide characteristics varied by 20%.

As can be seen from the above-mentioned Examples 1 to 4 and Comparative Examples 1 to 2, plastin ink optical fiber cords obtained by conventional extrusion molding of polyethylene, etc. However, the light guiding properties after one day vary by as much as 20%, whereas the plastic optical fiber cord obtained by reactively curing and coating plastin ink optical fiber with the photocurable resin composition according to the method of the present invention , 70° C., or 70° C. and 90% R1+, the light guide characteristics varied within 5% even after one week.

That is, it had a great effect on stabilizing the light guide characteristics over time under various environmental conditions.

In addition, the strength, chemical resistance, and weather resistance of the plastic optical fibers obtained in Examples 1 to 4 showed almost no difference from those of the plastic optical fiber cords obtained by conventional techniques, and stable characteristics were obtained. .

As explained above, the plastic ink optical fiber cord manufactured by the method for manufacturing a plastic optical fiber cord according to the present invention is more susceptible to various environmental conditions than the optical fiber cord manufactured by the conventional press molding method. It is characterized by extremely small fluctuations in light guiding characteristics. Therefore, there is an advantage that stable optical signal transmission can be performed using this plastic optical fiber cord.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing an example of an ultraviolet irradiation device used in the method of the present invention, and FIGS. 2 and 3 are schematic diagrams of a plastic optical fiber cord manufacturing line. 1...UV irradiation device, 3...-Mercury lamp,
4...Reflector, 7...Plastink optical fiber, 9...Resin coating device, 12... Constant temperature drying oven. Applicant's agent Tadashi Amemiya Season 1 Figure 2

Claims (1)

[Claims] (11) Coating a plastic optical fiber with a photocurable resin composition, then irradiating it with ultraviolet rays, and reacting and curing the resin composition at a temperature below the glass transition temperature of the core component of the plastic optical fiber. A method for producing a plastic optical fiber cord characterized by: