JPH09133821A - Plastic optical fiber - Google Patents

Abstract

(57) Abstract: A plastic optical fiber having high heat resistance, low transmission loss, and capable of transmitting a large capacity signal is provided. In a plastic optical fiber having a core portion having a multilayer structure of two or more layers and having a cladding layer on the outer side thereof, the core portion has 2,2-bis (4-hydroxyphenyl) -1,1, An aromatic polycarbonate obtained by reacting a dihydric phenol containing 1,3,3,3-hexafluoropropane and 9,9-bis (4-hydroxyphenyl) fluorene with a carbonate precursor. The mole fraction of the 9,9-bis (4-hydroxyphenyl) fluorene component constituting the aromatic polycarbonate in the inner layer (nth layer) of the core portion is higher than that in the outer layer (n + 1th layer). Is a high plastic optical fiber.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plastic optical fiber having a small transmission loss and capable of transmitting a large capacity signal and having excellent heat resistance.

[0002]

2. Description of the Related Art Although a plastic optical fiber has a large transmission loss and is unsuitable for long-distance transmission, it has flexibility and is easy to process a terminal. Is expected to be used. Since most of the plastic optical fibers have a core layer made of polymethylmethacrylate, they have a heat resistance of 100 ° C. or less and cannot be used in an engine room of an automobile or a heat resistant part of an electronic device. In order to improve this, a plastic optical fiber using polycarbonate (the following structural formula (A)) for the core layer has been used, and the plastic optical fiber using this polycarbonate also has a heat resistance of about 125 to 130 ° C. is there. In addition, such a heat-resistant plastic optical fiber has a step index and has a large aperture coefficient, so that the band is small and is about 100 MHz · 50 m. Therefore, there is a problem that a large capacity signal cannot be transmitted.

In order to solve this problem, acrylic G
Although an I-type plastic optical fiber has been developed, it has a problem of poor heat resistance because the core part is made of acrylic resin. Further, although the plastic optical fiber of this system can transmit light in the visible region of 660 nm, it cannot transmit light in the near infrared region of 780 nm or 950 nm. The LED of visible light in the 660 nm region has a problem that the operating speed is slower and the life is shorter and expensive than the LD and the LED of 780 nm and 950 nm.

[0004]

Embedded image

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a plastic optical fiber having high heat resistance, low transmission loss, and high capacity signal transmission.

[0006]

DISCLOSURE OF THE INVENTION The inventors of the present invention have found that, without achieving the above object, 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane and 9 As a result of extensive studies on a polycarbonate resin obtained by using 9,9-bis (4-hydroxyphenyl) fluorene as a raw material, this was used as a core layer, and as the inner layer was formed into 9,9-bis (4-hydroxy). The transmission loss is small and 780 nm due to the formation of multiple layers with a high proportion of the (phenyl) fluorene component.
It has been found that a plastic optical fiber having a high heat resistance and a wide band usable in a wavelength range can be obtained. The present invention has been completed based on this finding. According to the present invention, in a plastic optical fiber having a core portion having a multilayer structure of two or more layers and having a cladding layer on the outer side thereof, the core portion has 2,2-bis (4-hydroxyphenyl)-.
An aromatic polycarbonate obtained by reacting a dihydric phenol containing 1,1,1,3,3,3-hexafluoropropane and 9,9-bis (4-hydroxyphenyl) fluorene with a carbonate precursor. There
The inner layer (nth layer) of the core portion is the outer layer (nth layer).
+1 layer), the present invention relates to a plastic optical fiber having a higher mole fraction of 9,9-bis (4-hydroxyphenyl) fluorene component constituting an aromatic polycarbonate.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3 used in the present invention
-Hexafluoropropane and this and 9,9-bis (4
-Hydroxyphenyl) fluorene, a two-component dihydric phenol, and a plastic optical fiber having an aromatic polycarbonate obtained by reacting a carbonate precursor as a core agent have no absorption in the 780 nm and 950 nm regions, and an LED having a wavelength in this region. It is possible to perform optical transmission using. The LED and LD in the 780 nm region are inexpensive, operate at high speed, and have a long life. In the present invention,
The number of layers of the core is not particularly limited, but it is preferable that the number of layers is multilayer as long as there is no problem in processing. Further, the refractive index distribution is preferably close to a quadratic distribution based on the inner layer. That is, the refractive index of each layer is preferably close to a quadratic distribution with the inner layer as a reference.

In the present invention, when the plastic optical fiber of the present invention having a multilayered core, for example, k layers, has 1 to k layers from the innermost layer to the clad layer, the innermost n layer is the outermost n + 1 layer. The 9,9-bis (4-hydroxyphenyl) fluorene component of the dihydric phenol that is the raw material must be higher than the eye. This 9,
When the 9-bis (4-hydroxyphenyl) fluorene component is present in a larger amount in the outer layer portion, not only the transmission band is lowered, but also the transmission loss is significantly reduced.

Containing 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane and 9,9-bis (4-hydroxyphenyl) fluorene used in the core part The amount of 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane is 53 to 100 mol% and 9,9-bis (4-hydroxyphenyl) fluorene is used. It is 47 to 0 mol%. 2,2-bis (4-hydroxyphenyl)-
When the content of 1,1,1,3,3,3-hexafluoropropane is less than 53 mol%, not only the heat resistance is lowered, but also the workability of the plastic optical fiber is remarkably lowered. Preferably, the content of 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane is 60 mol% or more.

2,2-bis (4-hydroxyphenyl) used as the core material of the plastic optical fiber of the present invention
As -1,1,1,1,3,3,3-hexafluoropropane, a commercially available bisphenol AF purified using a benzene derivative and activated clay is preferably used.
As the benzene derivative, any of toluene, xylene and benzene is preferable, and one kind or a mixed solvent of two or more kinds may be used. The amount of these solvents used is such that bisphenol AF is sufficiently dissolved, that is, bisphenol AF.
2 to 10 times is necessary. The activated clay is a commercially available powder and granular activated clay mainly containing silica-alumina. Further, 9,9-bis (4-hydroxyphenyl) fluorene can be obtained by purification using dioxane.

In the present invention, 2,2-bis (4-hydroxyphenyl)-
Part of 1,1,1,3,3,3-hexafluoropropane or 9,9-bis (4-hydroxyphenyl) fluorene may be replaced with another dihydric phenol. Examples of other dihydric phenols include bisphenol A, bis (4-hydroxyphenyl) methane, and 2,2-bis (4
-Hydroxy-3-methylphenyl) propane, 4,4
-Bis (4-hydroxyphenyl) heptane, 2,2-
Bis (4-hydroxy-3,5-dichlorophenyl) propane, 2,2-bis (4-hydroxy-3,5-dibromophenyl) propane, bis (4-hydroxyphenyl) oxide, bis (3,5-dichloro-) 4-hydroxyphenyl) oxide, p, p'-dihydroxydiphenyl, 3,3'-dichloro-4,4'-dihydroxydiphenyl, bis (4-hydroxyphenyl) sulfone, bis (3,5-dimethyl-4-hydroxy) Phenyl) sulfone, resorcinol, hydroquinone, 1,
4-dihydroxy-2,5-dichlorobenzene, 1,4
-Dihydroxy-3-methylbenzene, bis (4-hydroxyphenyl) sulfide, bis (4-hydroxyphenyl) sulfoxide and the like are mentioned, and bisphenol A is particularly preferable. The amount of this other dihydric phenol is usually 10 mol% or less in the total dihydric phenol.

Next, examples of the carbonate precursor to be reacted with the above dihydric phenol include phosgene and diphenyl carbonate. To produce the aromatic polycarbonate of the present invention, conventional bisphenol A is used.
The method adopted when producing the polycarbonate from
For example, a reaction between bisphenol and phosgene or a transesterification reaction between bisphenol and bisaryl carbonate is adopted. For example, in the reaction of dihydric phenol and phosgene, the reaction is usually performed in the presence of an acid binder and an organic solvent. Examples of the acid binder include sodium hydroxide,
An alkali metal hydroxide such as potassium hydroxide, pyridine or the like is used. As the organic solvent, for example, a halogenated hydrocarbon such as methylene chloride chlorobenzene is used.
A catalyst such as a tertiary amine or a quaternary ammonium salt can be used to accelerate the reaction, and a terminal terminator such as phenol or p-tert-butylphenol is preferably used as the molecular weight modifier. It is preferable that the reaction temperature is usually 0 to 40 ° C., the reaction time is several minutes to 5 hours, and the pH during the reaction is usually 10 or higher. On the other hand, in the transesterification reaction, bisphenol and bisaryl carbonate are mixed in the presence of an inert gas, and the pressure is reduced to 120
React at ~ 350 ° C. The degree of decompression is changed step by step,
Finally, the phenols produced at a pressure of 1 mmHg or less are distilled out of the system. The reaction time is usually about 1 to 4 hours. You may add a molecular weight regulator and antioxidant as needed.

The thus-obtained aromatic polycarbonate having a high transmittance is 0.
The one having a specific viscosity of 0.160 to 0.418 at 20 ° C. measured by dissolving 7 g in methylene chloride 100 is suitable, and one having a specific viscosity of 0.165 to 0.345 is particularly preferable.
If the molecular weight is too small, the strength of the plastic optical fiber will decrease, and if it is too large, the moldability will greatly decrease, and further the transmission loss of the plastic optical fiber will greatly decrease. Further, after the synthesis, it is preferable to remove foreign matters sufficiently through a filter of about 0.1 μm using methylene chloride or the like as a solvent. In the present invention, an antioxidant, a light stabilizer and the like may be added to this aromatic polycarbonate as needed. In particular, it is preferable to mix at least one of phosphite-based, phenol-based, and organic ion-based antioxidants with the aromatic polycarbonate of the present invention.

As the clad layer, a tetrafluoroethylene-hexafluoroethylene copolymer, a tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer, an ethylene-tetrafluoroethylene copolymer, a fluorinated polymethylmethacrylate, Teflon AF, Examples include fluororesins such as TOP (trade name, manufactured by Asahi Glass Co., Ltd.), silicone resins, and imidized acrylic resins. The plastic optical fiber is manufactured by the conventional multilayer extrusion method,
Alternatively, it can be formed by using other methods. The temperature of the head when the plastic optical fiber is subjected to the multilayer spinning method is preferably 240 to 280 ° C.

[0015]

Next, the present invention will be described in more detail with reference to examples. In addition, the part in an example shows a weight part. The analysis was performed by the following method. Specific viscosity (polycarbonate) 0.7 g of a polymer was dissolved in 100 ml of methylene chloride and measured at 20 ° C. Transmission Loss (Plastic Optical Fiber) Using a 660 nm LED and a 760 nm LED as a light source, measurement was performed by a 10 m-1 m cutback method. After heat resistance, it was measured by the 9m-1m cutback method. Band The band was measured by a pulse method using an LD having a wavelength of 780 nm.

Synthesis of Polycarbonate A 48.5 in a reaction vessel equipped with a stirrer, thermometer, reflux condenser.
A 94% aqueous sodium hydroxide solution and 8251 parts of ion-exchanged water were added, and nitrogen gas was bubbled for about 30 minutes to deoxygenate. To this, 2.4 parts of hydrosulfite was added and purified using activated clay and toluene2.
2-bis (4-hydroxyphenyl) -1,1,1,
3,3,3-Hexafluoropropane 99.99% 1
After dissolving 740.5 parts, 6170 parts of methylene chloride was added, and 600 parts of phosgene was added to about 60 parts at 14 to 16 ° C. under stirring.
It took a minute to blow. Then, 42.7 parts of p-tert-butylphenol and 322.6 parts of a 48.5% sodium hydroxide aqueous solution were added and stirred to emulsify, then 10 parts of triethylamine was added, and the mixture was stirred at 30 ° C. for about 2 hours to react. Finished. After completion of the reaction, the product was diluted with methylene chloride, washed with water, acidified with hydrochloric acid and further washed with water, and when the conductivity of the aqueous phase became almost the same as that of ion-exchanged water, methylene chloride was evaporated to obtain a polymer. . The polymer had a specific viscosity of 0.175 and a glass transition temperature of 159 ° C.

Synthesis of Polycarbonate B 249 parts of ion-exchanged water and 16.4 parts of 48.5% aqueous sodium hydroxide solution were placed in a reaction vessel equipped with a stirrer, a thermometer and a reflux condenser, and bubbled with nitrogen gas for 30 minutes. Deoxidized. To this, 0.05 part of hydrosulfite was added, and 27.1 parts of 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane having 99.99% purity and Purified with dioxane 9
After dissolving 3.14 parts of 9,9-bis (4-hydroxyphenyl) fluorene having a purity of 9.8%, 267 parts of methylene chloride was added, and phosgene 10.
Four copies were blown in over 60 minutes. Then p-tert
-Butylphenol (0.67 parts) and 48.5% sodium hydroxide aqueous solution (5.6 parts) were added and stirred to emulsify, then triethylamine (0.02 part) was added, and the reaction was completed by stirring at 30 ° C for about 2 hours. did. After completion of the reaction, the product was diluted with methylene chloride, washed with water, acidified with hydrochloric acid and further washed with water, and when the conductivity of the aqueous phase became almost the same as that of ion-exchanged water, methylene chloride was evaporated to obtain a copolymer. Obtained. The copolymer had a specific viscosity of 0.211 and a glass transition temperature of 167 ° C. When the obtained polycarbonate was analyzed by NMR, it was found that, in the polymer, 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3
90% by mol of 3-hexafluoropropane component, 9,9
1-bis (4-hydroxyphenyl) fluorene component
It was 0 mol%.

Synthesis of Polycarbonate C 1897 parts of ion-exchanged water and 125 parts of 48.5% sodium hydroxide aqueous solution were put into a reaction tank equipped with a stirrer, a thermometer and a reflux condenser, and degassed by bubbling with nitrogen gas for 30 minutes. I got oxygen. Hydrosulfite (0.5 part) was added to this, and 183.5 parts of 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3-hexafluoropropane having a purity of 99.99% and Purified with dioxane 9
After dissolving 47.9 parts of 9,9-bis (4-hydroxyphenyl) fluorene having a purity of 9.8%, 2038 parts of methylene chloride was added, and phosgene 7 was added under stirring at 14 to 16 ° C.
9.1 parts was blown in after 50 minutes. Then p-ter
6.7 parts of t-butylphenol and 42.5 parts of a 48.5% aqueous sodium hydroxide solution were added and stirred to emulsify, then 0.17 parts of triethylamine was added and stirred at 30 ° C. for 2 hours to complete the reaction. . After completion of the reaction, the product was diluted with methylene chloride, washed with water, acidified with hydrochloric acid and further washed with water, and when the conductivity of the aqueous phase became almost the same as that of ion-exchanged water, methylene chloride was evaporated to obtain a copolymer. Obtained. The copolymer had a specific viscosity of 0.177 and a glass transition temperature of 178 ° C. When the obtained polycarbonate was analyzed by NMR, it was found that, in the polymer, 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3
3-hexafluoropropane component 80 mol%, 9,9
-Bis (4-hydroxyphenyl) fluorene component is 2
It was 0 mol%.

Example 1 The polycarbonate resin of B and A, from which dust was removed through a 0.1 μm filter, was added to the resin introduction passage of the double extruder with B as the inner layer and A as the outer layer, and the head temperature was 245.
Spun at ° C. A plastic optical fiber having a two-layer core and a clad by installing a die in the middle of spinning, adding a thermosetting silicone resin (X38-091HAB: manufactured by Shin-Etsu Chemical Co., Ltd.) into the die, and further curing the resin in a lower furnace. Got The diameter of the inner layer was 0.60 mm. The obtained plastic optical fiber had a core diameter of 0.94 mm and a clad outer diameter of 1.0 mm. Also, the transmission loss is 50
0 dB / km (760 nm: LED) with a band of 4
It was 00 MHz and 50 m. When the obtained plastic optical fiber was left at 140 ° C. for one month, the transmission loss was 530 dB / km (760 nm: LED).

Example 2 The above C and A polycarbonate resins from which dust had been removed through a 0.1 μm filter were added to the resin introduction passage of a double extruder with C as the inner layer and A as the outer layer, and the head temperature was set to 255.
Spun at ° C. A plastic optical fiber having a two-layer core and a clad by installing a die in the middle of spinning, adding a thermosetting silicone resin (X38-091HAB: manufactured by Shin-Etsu Chemical Co., Ltd.) into the die, and further curing the resin in a lower furnace. Got The diameter of the inner layer was 0.60 mm. The obtained plastic optical fiber had a core diameter of 0.94 mm and a clad outer diameter of 1.0 mm. The transmission loss is 65
0 dB / km (760 nm: LED) with a bandwidth of 5
It was 50 MHz and 50 m. When the obtained plastic optical fiber was left at 140 ° C. for one month, the transmission loss was 700 dB / km (760 nm: LED).

Example 3 The above polycarbonate resins C, B and A from which dust had been removed through a 0.1 μm filter were added to the resin introduction passage of a triple extruder, with the inner layer being C, the middle layer being B and the outer layer being A. Spinning was performed at a head temperature of 255 ° C. A die is installed in the middle of spinning, and a thermosetting silicone resin (X38-091
HAB: manufactured by Shin-Etsu Chemical Co., Ltd. was added and further cured in a lower furnace to obtain a plastic optical fiber having a two-layer core and clad. Inner layer diameter is 0.55m
m, the diameter of the middle layer was 0.77 mm. The obtained plastic optical fiber had a core diameter of 0.94 mm and a clad outer diameter of 1.0 mm. The transmission loss is 800 dB /
km (760 nm: LED), bandwidth is 700 MH
It was z.50m. When the obtained plastic optical fiber was left at 140 ° C for 1 month, the transmission loss was 8
It was 40 dB / km (760 nm: LED).

Comparative Example 1 The above-mentioned A in which dust was removed through a 0.1 μm filter
Add the polycarbonate resin of to the resin introduction path of the extruder,
Spinning was performed at a head temperature of 240 ° C. A die is installed in the middle of spinning and the thermosetting silicone resin (X38-09
1HAB: manufactured by Shin-Etsu Chemical Co., Ltd. was added and further cured in a lower furnace to obtain a plastic optical fiber having a core and a clad. The obtained plastic optical fiber has a core diameter of 0.94 mm and a cladding outer diameter of 1.0 m.
m. The transmission loss is 500 dB / km (760
nm: LED) and the band was 80 MHz · 50 m. Also, the obtained plastic optical fiber is
Transmission loss is 530 dB / km when left for 1 month at
(760 nm: LED).

Comparative Example 2 Panlite AD-9000TG (polycarbonate made by Teijin Chemicals, bisphenol A type) and a polycarbonate resin of A from which dust was removed through a filter of 0.1 μm were designated as Panlite AD-9000TG for the inner layer and A for the outer layer.
In addition to the resin introduction furnace of the heavy extruder, spinning was carried out at a head temperature of 240 ° C. A plastic optical fiber having a two-layer core and a clad by installing a die in the middle of spinning, adding a thermosetting silicone resin (X38-091HAB: manufactured by Shin-Etsu Chemical Co., Ltd.) into the die, and further curing the resin in a lower furnace. Got The inner layer was 0.60 mm. The obtained plastic optical fiber had a core diameter of 0.94 mm and a clad outer diameter of 1.0 mm. The transmission loss is 1500
dB / km (760 nm: LED), bandwidth is 15
It was 0 MHz and 50 m. When the obtained plastic optical fiber was left at 140 ° C. for one month, the transmission loss was very large and could not be measured.

Comparative Example 3 A plastic optical fiber was obtained in the same manner as in Example 1, except that the polycarbonate resin of A and B from which dust was removed through a 0.1 μm filter was used as the inner layer of A and the outer layer of B. The diameter of the inner layer was 0.60 mm. The obtained plastic optical fiber had a core diameter of 0.94 mm and a clad outer diameter of 1.0 mm. The transmission loss is 800 dB /
km (760 nm: LED), bandwidth is 60 MHz
・ It was 50 m. When the obtained plastic optical fiber was left at 140 ° C for 1 month, the transmission loss was 83
It was 0 dB / km (760 nm: LED).

[0025]

According to the present invention, 2,2-bis (4-hydroxyphenyl) -1,1,1,3,3,3 is added to the core portion.
-Hexafluoropropane and this and 9,9-bis (4
-Hydroxyphenyl) fluorene binary diphenols by reacting a carbonate precursor with an aromatic polycarbonate obtained by arranging 780
It is possible to obtain a plastic optical fiber having a large transmission band with a small transmission loss in the nm band and high heat resistance. This plastic optical fiber can be used as various high-speed optical signal transmission lines and its effect is great.

Claims (1)

[Claims] 1. A plastic optical fiber having a core portion having a multilayer structure of two or more layers and having a cladding layer on the outside thereof, wherein the core portion is 2,2-bis (4-hydroxyphenyl)-.
An aromatic polycarbonate obtained by reacting a dihydric phenol containing 1,1,1,3,3,3-hexafluoropropane and 9,9-bis (4-hydroxyphenyl) fluorene with a carbonate precursor. There
The inner layer (nth layer) of the core portion is the outer layer (nth layer).
+1 layer), a plastic optical fiber having a higher mole fraction of the 9,9-bis (4-hydroxyphenyl) fluorene component constituting the aromatic polycarbonate.