KR100291659B1 - Method for manufacturing polymer optical waveguide - Google Patents

Abstract

PURPOSE: A method for manufacturing a polymer optical waveguide is provided to increase a transmission speed by changing a refractive index distribution of a wave guide. CONSTITUTION: A chamber(5) capable of controlling a temperature is filled with a refined nitrogen gas. A reactor(3) installed on an inner side of the chamber(5) is rotated at a speed of 1,000-3,000rpm. The reactor(3) performs a polymerization on a main material to complete a clad of a preform. A refractive index control agent and the main material are polymerized by the reactor(3). After the polymerization, a polymer is divided from the reactor(3). The polymer is polymerized with a polymerization solution at a predetermined temperature. After performing a post-polymerizing process on the polymer, the preform for an optical waveguide is formed.

Description

Manufacturing Method of Polymer Optical Transporter

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an optical transmitter using characteristics of a polymer material having excellent transparency, and more particularly, to a manufacturing of an optical transmitter having a different refractive index distribution of a transmitter in order to increase a transmission speed.

The light transmitting body mainly uses quartz glass as a material. The use of quartz glass optical transmitters is increasing rapidly as a means of communication transmission in recent years.

However, quartz glass optical transmitters (optical fibers) have low flexibility because the material used is glass, and they are preferred in the case of very small diameters in the manufacturing process. Therefore, optical transmitters used in buildings are improved in use even though they have excellent optical properties. There are many things to do.

In other words, when changing the free position in the use of a short distance and frequently need to change the connection, the stone glass light transmission body does not play its role.

In order to cope with this, the polymer optical transmission body, which is excellent in optical properties, excellent in flexibility, and capable of manufacturing a transporter having a certain large diameter in the manufacturing process, was examined.

However, the polymer optical transmitter developed so far has a convenience in use, but since the optical characteristics are inferior to that of the quartz optical transmitter, a manufacturing method for improving the optical characteristics while maintaining the excellent characteristics of the polymer has been studied.

Until now, since the core of the polymer optical transmitter has a single index of refraction, when the light passes, the bending occurs at the clad, which is a reflection surface outside the core. The waveform is transformed from the waveform.

In this case, the transmission speed can be increased if a transmitter having a shape in which incident light is refracted in the transmitter in order to eliminate the line break in the reflection surface is manufactured.

In the present invention will be described with respect to the manufacture of an optical transport having a polymer and having a refractive index distribution in the transport.

The line bending phenomenon of the core reflection surface is shown in FIG. Accordingly, it can be seen that the incident waveform is distorted after being outputted through the transmission body, so it is not suitable for high speed transmission.

As a material of such a polymer optical transmission material, polymethyl methacrylate, polystyrene, polycarbonate, etc. which are excellent in light transmittance are used as a core material. In the manufacturing method, since the refractive index of the core is not changed, it is usually manufactured as a simple structure of core extrusion and clad extrusion. In order to reduce the thermal aging of the polymer as much as possible, two methods of pre-polymerizing core substrates (also called preforms) directly from monomers and manufacturing optical transmission bodies from the substrates by a general fiber manufacturing method are common. to be.

As shown in FIG. 2, the incident wave is refracted and transmitted without the line bending phenomenon. As shown, it can be seen that even after the incident waveform passes through the transmitter, the output waveform maintains the same shape as the incident waveform, so that it can be used for high-speed transmission.

In order to manufacture the polymer optical transporter of this type, a method of changing the refractive index in the core has been proposed. As a material to be used, polymethyl methacrylate, polystyrene, polycarbonate and the like having excellent light transmittance may be used. Several methods have already been proposed in the manufacturing method.

For example, the method described in US Pat. No. 5,541,247 incorporates additives that have a higher refractive index and do not affect the mutual reaction in the materials listed above, and then polymerize from the outside while completely sealing and rotating horizontally. It is a method to complete the polymerization to the central axis.

The additive used in this method is not directly involved in the polymerization reaction, but continues to exist in the polymer even after the polymerization and serves to control the refractive index when light passes through.

This method can impart a refractive index distribution to core, but has some problems as follows.

Firstly, since additives are stochastically distributed in the preparation of the base material, it is very difficult to artificially control the refractive index distribution in the core, which is dependent on the reaction state during the polymerization process. Therefore, in order to show the refractive index distribution as designed, it is very difficult to manufacture the base metal first. Therefore, in terms of production process control, only good ones can be used after the inspection.

Next, the size of the substrate is limited (about 1 cm in diameter), and the length that can be manufactured when manufacturing the optical transmitter (about 1 mm in diameter) from the base material is extremely limited, so that the length of the optical transmitter required (at least 200 m) is not reached. Many times you can't. Therefore, there is a big limitation in the commercial use.

In addition, in the proposed production method, at the same time injecting monomers and additives into the reaction vessel to ensure that no bubbles inside the reaction vessel at all, this task also has a problem.

The reaction vessel is filled with monomers and additives and then sealed, and then the reaction proceeds. As a result, volume shrinkage occurs after volume expansion.

At this time, because the reaction vessel is destroyed or the reaction occurs instantaneously due to the internal high pressure, the overall distribution of the additive may not occur.

For this reason, commercialization of polymer optical transmitters having a refractive index distribution has been delayed, and studies on productivity improvement have been continued.

In another example, the method described in US Pat. No. 5,614,253 is prepared by spraying the outer layer to the inner layer in a horizontal reaction vessel while adding to the diluent solution to a solvent having excellent volatility and solubility to the monomers presented above in the preparation of the base material. The reaction is controlled by adjusting the amount of the additive as it goes.

In this way, the polymer optical transmission body is manufactured using the prepared base material. This method can arbitrarily adjust the refractive index distribution of the base material and can make the size of the base material not significantly restricted, but this method also has the following problems.

That is, no matter how highly volatile a solvent is used, there may be a solvent remaining in the base metal and it is not so easy to remove the remaining solvent. This residual solvent causes fatal light loss in the polymer optical transmission body.

Therefore, the present invention was devised to solve the problems of the prior art as described above, and an object of the present invention is to arbitrarily adjust the refractive index distribution and to reduce the light transmission loss because the solvent is not used as a diluent. It is an object of the present invention to provide a method for producing a polymer optical transmission member that can be easily manufactured to produce a sufficient length usable as an optical transmission member.

In order to achieve the above object, the present invention is a transparent resin having a refractive index difference of 5% or more after the reaction is carried out while rotating at a high speed to the monomer capable of polymerization in the optically excellent resin, the polymerization initiator, the chain transfer agent in a horizontal rotating reactor The reaction proceeds again while increasing the amount of material proportionally, increasing the refractive index from the outside of the reactor toward the center, and filling the space at the center with a low polymerization solution with a slightly larger refractive index to prepare the base material of the polymer optical transmission body. It is done.

Other objects and advantages of the invention will be described below and will be appreciated by the practice of the invention. Furthermore, the objects and advantages of the present invention can be realized by means and combinations indicated in the appended claims.

FIG. 1 shows a conventional optical transmission body having a line break phenomenon.

2 shows an optical transmission body having a refractive index distribution produced by the present invention and having a line break phenomenon.

3 shows a conceptual diagram of a circular reactor for producing a polymer optical transmission body according to the present invention.

* Explanation of symbols for main parts of the drawings

1: Main material reservoir 2: Refractive index distribution control reservoir

3: reactor 4: inlet

5: chamber

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The present inventors have developed a new method that exhibits excellent optical properties required by the polymer optical transmission body, can arbitrarily adjust the refractive index distribution according to the designer's request, and can manufacture a sufficient length as the optical transmission body.

In order to manufacture an optical transmitter having a refractive index distribution, a base material having a refractive index distribution must first be manufactured, and a fibrous optical transmitter having a constant diameter is manufactured by using a known radiation method.

Therefore, the production of a base material having a refractive index distribution will be the most important technology, and here, the production of a base material capable of controlling the refractive index distribution will be described.

3 shows a schematic diagram of the base material manufacturing. As shown, the nitrogen gas is continuously injected during the reaction progress after filling the purified nitrogen gas into the chamber (5) capable of temperature control. Within the chamber 5 is installed a reactor 3 which is kept exactly horizontal, which can rotate up to 1000-3000 rpm.

On the other hand, the main material reservoir 1 and the refractive index distribution control reservoir 2 are connected to the other side of the reactor 3. The main material reservoir 1 is mixed with a main monomer, a polymerization initiator and a chain transfer agent, and the refractive index distribution control reservoir 2 has a refractive index about 10% larger than the refractive index indicated after polymerization of the main monomer. When mixed with, use a material that can be completely mixed.

The main material reservoir 1 and the refractive index distribution control reservoir 2 can be freely adjusted and injected into the reactor 3 through the inlet 4.

Hereinafter, a base material manufacturing process will be described based on the schematic diagram of FIG. 3.

The temperature is set to a proper temperature while rotating the reactor 3 in the chamber 5 filled with nitrogen. Next, the main material is measured in an appropriate amount and injected into the reactor 3 through the inlet 4. At this time, since the reactor 3 is rotating at a high speed, the injected amount is evenly distributed and a polymerization reaction occurs in the form of a tub of a predetermined thickness. After the completion of the complete polymerization, the thickness deviation and foundation on the tube are examined. This is the cladding of the base metal.

After the end of this work, the refractive index regulator is added to the main material little by little through the injection hole (4). At this time, when the reaction is completely finished, the amount of the refractive index control agent should be added in proportion so that the amount of the refractive index adjusting agent does not exceed 40% by weight in the main material.

On the other hand, since the polymerization rate may vary depending on the type, amount of the polymerization initiator used in the polymerization reaction, and the type and amount of the chain transfer agent, the input amount must be controlled so that the mixed solution is first polymerized first. If a lot is put together at the same time, careful attention is required because it does not show the refractive index distribution as required by the designer.

After the polymerization to the inside as described above can no longer be injected through the inlet 4, the reactor (3) is rotated continuously to fully polymerize and the polymer is separated from the reactor (3).

Since the separated polymer remains in the space at the center, it cannot be used as a base material as it is. The polymerization solution is 100Poise while polymerizing the polymerization solution that is added 1-2% more than the refractive index control agent for the last reaction stage with the space remaining on the central axis at the appropriate temperature (different depending on the type and amount of initiator). When it starts to show a degree of viscosity, the temperature is lowered, and once the reaction is stopped, the other side is filled with the low-polymerization solution while inhaling one side of the central axis of space. This is to prevent the formation of the micro-air layer by the phenomenon that the low polymer continues to shrink when the polymerization reaction occurs.

After the above-described operation, the base material is manufactured through a post-polymerization process, and the property test of the base material is performed while measuring the refractive index distribution curve by using a refractive index analyzer.

In general, methyl methacrylate is used as the main material of the polymer optical transporter. Since the refractive index after polymerization is 1.49, the refractive index regulator used in the above reaction should be higher than 1.49.

As such a material, benzyl benzoate, benzyl n-butyl phthalate, diphenyl sulfide, bromobenzene, dichlorobenzene, dibromobenzene, styrene monomer and the like can be used. When methyl methacrylate is used as the main material for the refractive index distribution inspection of the base material, the refractive index index (g) is represented to be between 2 and 2.5 because most of the light sources of the polymer optical transmitter use a wavelength of 650 nm. It is necessary to select and adjust the refractive index regulator.

Example 1

A glass tube with a diameter of 15 mm and a length of 200 mm is prepared and horizontally fixed to one side as shown in FIG. On the other hand, in the main material reservoir (1) was prepared a main solution containing a methyl methacrylate monomer, 0.4% by weight of benzoyl peroxide as a polymerization initiator, and 0.1% (weight ratio) of normal butyl mercapcan as a chain transfer agent.

On the other hand, the refractive index distribution control reservoir (2) was prepared by mixing a styrene monomer, 0.5% by weight of benzoyl peroxide as a polymerization initiator, and 0.12% (weight ratio) of normal butyl mercapcan as a chain transfer agent.

The reactor 3 is rotated at 1800 rpm while maintaining the chamber 5 sufficiently filled with nitrogen at a temperature of 100 ° C.

Initially, only a small amount of the main solution of the main material reservoir 1 was injected through the inlet 4, and after the polymerization was 15 mm, the injection was stopped once, and the polymerization reaction was continued for 6 hours while continuing to rotate.

This completes the polymethyl methacrylate tube, which acts as a clad for the polymer optical transmitter.

While continuously rotating the glass tube in the state of the polymethyl methacrylate tube, the ratio of the main solution of the main material reservoir 1 and the refractive index regulator of the refractive index distribution control reservoir 2 starts at 100: 1 and finally 100 The polymerization reaction is carried out while injecting a solution of the main material reservoir 1 and the refractive index distribution control reservoir 2 into the reactor 3 while adjusting the ratio to be 20.

In this case, it is very important to first polymerize the first injected solution because the polymerization reaction and reactant injection occur at the same time. If the next reaction solution is injected before the first injection even before the polymerization reaction occurs, it should be noted that the refractive index distribution may not be as designed by the later base metal inspection.

When the reaction is completed after the whole amount is injected, space remains on the central axis. The mixed solution of the refractive index distribution control reservoir (2) solution with respect to the main material reservoir (1) solution is 100: 22 and kneaded at 100 ° C. for 40 minutes. When the reaction was carried out, a low-polymer having a viscosity of about 100 Poise was obtained, which was then low-pressure filled in the central axis space, followed by post-polymerization at 120 ° C. for 8 hours to complete the base material.

In the prepared base material, the refractive index distribution curve was measured after removing unreacted substances such as low molecular weight monomer from the vacuum chamber at 100 ° C. for more than 20 hours, and the refractive index distribution index (g) was 1.92. On the other hand, in the manufacture of the optical transmission body, a polymer optical transmission body having a diameter of 1 mm was manufactured in a nitrogen cycle in which a furnace temperature was 200-220 ° C. in a vertically-heated radiating radiator.

The refractive index distribution of the prepared polymer optical transmission body was measured, and the optical properties were measured after confirming that they were in substantially the same state as the base material.

The optical loss was measured using a known photometer, spectrum analyzer, etc., and 160 dB / km (650 nm) was obtained. On the other hand, the measurement of the optical transmission rate was measured using a 650nm light source and a pulse generator capable of up to 1Giga. As a result, it was confirmed that the optical transmission speed had a transmission rate of 1Giga in the range of 4dB distortion (distortion phenomenon).

Example 2

A glass tube of 15 mm in diameter and 300 mm in length is prepared and horizontally fixed to one side as shown in FIG. On the other hand, in the main material reservoir (1) was prepared a main solution containing a methyl methacrylate monomer, 0.4% by weight of benzoyl peroxide as a polymerization initiator, and 0.1% (weight ratio) of normal butyl mercapcan as a chain transfer agent.

On the other hand, the diphenyl sulfide was mixed with the same solution (weight ratio) in the same refractive index distribution control reservoir 2 as the main material reservoir 1.

The reactor 3 is rotated at 1800 rpm while maintaining the chamber 5 sufficiently filled with nitrogen at a temperature of 100 ° C.

Initially, only a small amount of the main solution of the main material reservoir 1 was injected through the inlet 4, but after the polymerization had a thickness of 15 mm, the injection was stopped once, and the polymerization reaction was continued for 6 hours while continuing to rotate.

This completes the polymethyl methacrylate tube, which acts as a clad for the polymer optical transmitter.

While continuously rotating the glass tube in the state of the polymethyl methacrylate tube, the ratio of the main solution of the main material reservoir 1 and the refractive index regulator of the refractive index distribution control reservoir 2 starts at 100: 1 and finally 100 The polymerization reaction is carried out while injecting the solution of the main material reservoir 1 and the refractive index distribution control reservoir 2 into the reactor 3 while adjusting to 40.

In this case, it is very important to first polymerize the first injected solution because the polymerization reaction and reactant injection occur at the same time. If the next reaction solution is injected before the first injection even before the polymerization reaction occurs, it should be noted that the refractive index distribution may not be as designed by the later base metal inspection.

When the reaction is completed after the whole amount is injected, there is a space on the central axis. The mixed solution in which the ratio of the refractive index distribution control reservoir (2) to the main material reservoir (1) solution is 100: 44 is kneaded at 100 ° C. for 40 minutes. When the reaction was carried out, a low-polymer having a viscosity of about 100 Poise was obtained, which was then low-pressure filled in the central axis space, followed by post-polymerization at 120 ° C. for 8 hours to complete the base material.

The prepared base material was sufficiently removed at 100 ° C. for 20 hours or more in a vacuum chamber to remove unreacted substances such as low molecular weight monomers, and then the refractive index distribution curve was measured, and the refractive index distribution index (g) was 1.89. On the other hand, in the manufacture of the optical transmission body, a polymer optical transmission body having a diameter of 1 mm was manufactured in a nitrogen cycle in which a furnace temperature was 200-220 ° C. in a vertically-heated radiating radiator.

The refractive index distribution of the prepared polymer optical transmission body was measured, and the optical properties were measured after confirming that they were in substantially the same state as the base material.

The optical loss was measured using a known photometer, spectrum analyzer, and the like, and 130 dB / km (650 nm) was obtained. On the other hand, the measurement of the optical transmission rate was measured using a 650nm light source and a pulse generator capable of up to 1Giga. As a result, it was confirmed that the optical transmission speed had a transmission rate of 1Giga in the range of 4dB distortion (distortion phenomenon).

Example 3

A glass tube of 15 mm in diameter and 300 mm in length is prepared and horizontally fixed to one side as shown in FIG. On the other hand, in the main material reservoir (1) was prepared a main solution containing a methyl methacrylate monomer, 0.4% by weight of benzoyl peroxide as a polymerization initiator, and 0.1% (weight ratio) of normal butyl mercapcan as a chain transfer agent.

In the refractive index distribution control reservoir 2, 1.2 dibromoethane was mixed in the same solution as the main material reservoir 1 in the same ratio (weight ratio).

The reactor 3 is rotated at 1800 rpm while maintaining the chamber 5 sufficiently filled with nitrogen at a temperature of 100 ° C.

Initially, only a small amount of the main solution of the main material reservoir 1 was injected through the inlet 4, and after the polymerization was 15 mm, the injection was stopped once, and the polymerization reaction was continued for 6 hours while continuing to rotate.

This completes the polymethyl methacrylate tube, which acts as a clad for the polymer optical transmitter.

While continuously rotating the glass tube in the state of the polymethyl methacrylate tube, the ratio of the main solution of the main material reservoir 1 and the refractive index regulator of the refractive index distribution control reservoir 2 starts at 100: 1 and finally 100 The polymerization reaction is carried out while injecting the solution of the main material reservoir 1 and the refractive index distribution control reservoir 2 into the reactor 3 while adjusting to 40.

In this case, it is very important to first polymerize the first injected solution because the polymerization reaction and reactant injection occur at the same time. If the next reaction solution is injected before the first injection even before the polymerization reaction occurs, it should be noted that the refractive index distribution may not be as designed by the later base metal inspection.

When the reaction is completed after the whole amount is injected, there is a space on the central axis. The mixed solution in which the ratio of the refractive index distribution control reservoir (2) to the main material reservoir (1) solution is 100: 44 is kneaded at 100 ° C. for 40 minutes. When the reaction was carried out, a low-polymer having a viscosity of about 100 Poise was obtained, which was then low-pressure filled in the central axis space, followed by post-polymerization at 120 ° C. for 8 hours to complete the base material.

In the prepared base material, the refractive index distribution curve was measured after removing unreacted substances such as low molecular weight monomer from the vacuum chamber at 100 ° C. for 20 hours or more, and the refractive index distribution index (g) was 1.94. On the other hand, in the manufacture of the optical transmission body, a polymer optical transmission body having a diameter of 1 mm was manufactured in a nitrogen cycle in which a furnace temperature was 200-220 ° C. in a vertically-heated radiating radiator.

The refractive index distribution of the prepared polymer optical transmission body was measured, and the optical properties were measured after confirming that they were in substantially the same state as the base material.

The optical loss was measured using a known photometer, spectrum analyzer, and the like, and 150 dB / km (650 nm) was obtained. On the other hand, the measurement of the optical transmission rate was measured using a 650nm light source and a pulse generator capable of up to 1Giga. As a result, it was confirmed that the transmission speed was 1Giga in the range of 4dB change (distortion phenomenon).

The present invention is not limited to the above embodiments, and various modifications and variations are possible by those skilled in the art within the scope of the technical spirit of the present invention and the equivalent scope of the claims to be described below. Of course.

As described above, the present invention can arbitrarily adjust the refractive index distribution, and there is little light transmission loss since no solvent is used as the diluent. In addition, it is easy to manufacture a large-diameter base material, and a sufficient length that can be used as an optical transmission body can be manufactured.

Claims (3)

Filling the purified nitrogen gas into a temperature control chamber; Rotating the reactor installed inside the chamber at a speed of 1000 to 3000 rpm; Completing the cladding of the base material by injecting the main material mixed with the main monomer, the polymerization initiator, and the chain mover into the reactor to cause the polymerization reaction in the form of a tube having a predetermined thickness; Injecting a refractive index regulator with a main material into the reactor, the refractive index having a refractive index of about 10% greater than the refractive index after polymerization of the main monomer; Polymerizing to the inside through the above step and continuing the reactor rotation to sufficiently polymerize and separating the polymer from the reactor; The polymerization solution started to show a viscosity of about 100 Poise while polymerizing the polymerization solution at 1 ~ 2% more than the refractive index control agent for the last reaction stage with space remaining on the central axis of the separated polymer. When the temperature is lowered, and once the reaction is stopped and the suction of one side of the central axis of the space is filled with the low-polymerization solution on the other side, the method of producing a polymer optical transmission body. The method of claim 1, wherein the amount of the refractive index control agent is adjusted so that it is put in a horizontally rotating reactor to have a refractive index distribution. The method of claim 1 or 2, wherein the polymer optical transmitter is produced by a thermal stretching process using the prepared mother agent.

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