KR20030012783A - Cavity-Preventing Type Reactor and Method for Fabricating Preform for Plastic Optical Fiber Using the Same - Google Patents

Abstract

PURPOSE: A reactor for preventing a cavity and a method for manufacturing a base material for a plastic optical fiber using the same are provided to prevent the cavity formation due to volume contraction phenomenon by controlling a refractive index grade of a radius direction and a longitudinal direction. CONSTITUTION: An input unit(10) includes a reactant inflow hole(11) for flowing a reactant in the whole of a reactor. A reacting unit(20) is provided by setting a blocking wall(32) between the reacting unit(20) and the input unit(10) and includes a channel(21) connecting to the input unit(10) on the center of the blocking wall(32). A cavity blocking structure(30) is installed between the channel(21) of the reacting unit(20) and the reactant inflow hole(11) of the input unit(10) so that a cavity is not continued to the reacting unit(20), and includes one or one more channels(31) so that the reactant flows in the reacting unit(20).

Description

Cavity-Preventing Type Reactor and Method for Fabricating Preform for Plastic Optical Fiber Using the Same}

The present invention relates to a hollow anti-reactor and a method for manufacturing a base material for plastic optical fibers using the same, and more particularly, to prevent the hollow formation by the volume shrinkage phenomenon generated by polymerizing the monomer under rotation to avoid the additional monomer injection process It relates to a hollow prevention reactor and a method of manufacturing a base material for plastic optical fiber using the same.

Communication optical fibers are classified into single-mode fiber and multi-mode fiber according to the transmission mode of the optical signal. Most of the optical fiber for long distance high speed communication currently used is a step-index single-mode optical fiber based on quartz glass, and the glass optical fiber has a fine thickness of only 5 to 10 탆 in diameter. Therefore, such glass optical fibers are very difficult to align and connect, resulting in high cost loss. On the other hand, multimode glass fiber having a larger diameter than single mode fiber can be used for short-distance communication such as LAN (local area network), but it is difficult to be widely used due to the high cost and fragile disadvantage of connection. Many. Therefore, metal cables, such as twisted pairs or coaxial cables, have been mainly used for short range communications within 200m, such as LANs. However, since the metal wire has a maximum information transfer rate (or bandwidth) of about 150 Mbps, it cannot meet 625 Mbps, which is the Asynchronous Transfer Mode (ATM) standard of the 2000s, and thus can satisfy the future transfer rate standard. There was no. For this reason, there have been many efforts and investments in the development of polymer optical fibers that can be used for short-range communication such as LAN over the last decade in Japan and the United States. Due to the flexibility of the polymer material, the polymer optical fiber can reach 0.5 to 1.0 mm, which is more than 100 times larger than the glass fiber, so that the polymer optical fiber can be easily aligned or connected, and the polymer material connectors manufactured by extrusion molding can be used. As a result, large cost savings can be expected.

Meanwhile, the polymer optical fiber may have a step-index (SI) structure in which the refractive index change in the radial direction is stepped, or a graded-index (GI) structure in which the refractive index gradually changes in the radial direction. Because of the high modal dispersion of polymer optical fibers, the signal transmission speed (or transmission bandwidth) cannot be faster than the metal cable, whereas GI polymer optical fibers can have high bandwidth because of the small modal dispersion. have. Therefore, the GI polymer optical fiber is known to be suitable as a medium for short distance high speed communication due to the cost saving effect resulting from the thick diameter and the high information transmission speed due to the small modal dispersion.

As the manufacturing process of the conventional GI polymer optical fiber, the method of interfacial gel polymerization by Professor Koei Kei of Japan Keio University was first announced in 1988 (Koike, Y. et al., Applied Optics, vol. 27, 486). (1988) then US 5,253,323 to Nippon Petrochemicals Co .; U.S. Patent 5,382,448 to Nippon Petrochemicals Co .; US Pat. No. 5,593,621 to Yasuhiro Koike and Ryo Nihei; WO 92/03750; WO 92/03751 (Yasuhiro Koike / Nippon Petrochemical Co.); Japanese Patent 3-78706 (Mitsubishi Rayon); And Japanese Patent No. 4-86603 (Toray Ind.) Discloses a related content. Most of the processes related to the patent can be roughly divided into two kinds of processes as follows.

First, there is a batch process for producing a GI polymer optical fiber by making a preform, that is, a preform, in which a refractive index is changed in a radial direction using a polymer and a relatively small molecular weight additive, and then heating and stretching the base material.

Secondly, after manufacturing the polymer fiber by the extrusion process, a low molecular weight material added to the fiber is extracted radially, or conversely, a low molecular weight material is added radially to prepare a GI polymer optical fiber. have.

The first process was developed by Professor Koike and succeeded in producing a GI polymer optical fiber with a transmission rate of 2.5 Gbps, and the second process was known to succeed in manufacturing a polymer optical fiber with a relatively high transmission bandwidth. Most of the above-mentioned methods use well-known facts that the process proceeds while rotating in a state of laying down or standing so that the refractive index gradient does not collapse by gravity.

On the other hand, the method recently developed by Van Duijnhoven and Bastiaansen in the Netherlands and disclosed in WO 97/29903 and registered in US Pat. No. 6,166,107 uses a very powerful rotation of about 20,000 rpm using rotation. This method is described in other prior arts mentioned in the patent (“Review of Polymer Optical Fibers”, Emslie, C., Journal of Materials Science, 23 (1988), pages 2281-2293, WO 92/10357, DE-C1). -42 14 259, WO 87/01071), polymerizing monomers having different densities and refractive indices or mixtures of polymers dissolved in monomers under very strong centrifugal force, gives rise to concentration gradients according to density gradients. The method of ultrafast Winshim separation, which produces a gradient, is used, however, the above method is limited in the selection of the monomer to be used since the monomer having a higher density must have a smaller refractive index than the monomer having a lower density. No mention was made of the problem of volumetric shrinkage that occurs, ie, when the monomer polymerizes into a polymer, volume shrinkage occurs, causing centrifugation. The base material for plastic optical fiber made by force will have hollow tubular hollow in the middle part, and additional monomer input process will be required to fill this hollow, so the method of manufacturing the base material using other rotation is practical. It is difficult to say that there is an improvement in the manufacturing time compared to the case of the present invention. In addition, there is a limitation in the actual use because it causes a reduction in the amount of light, and may also cause a deterioration in optical properties due to external factors caused by contact with air or moisture or fine dust during the addition process. Equipment and costs. Huh the like is advantageous in controlling the refractive index difference is greater when the rotation speed is large central core and the cladding near but not emitted at all is referred to as the refractive index gradient produced only higher by the rotation of the following equation 10,000 × d ^-0.5 In practice, however, it is overlooked that if a centrifugal force field is formed in a monomer mixture with a difference in density, whether the rotational speed is large or small, the concentration gradient always occurs in proportion.

One object of the present invention for solving the problems of the prior art as described above is to provide a newly designed hollow-prevention reactor so that no additional injection step of monomers is required.

Another object of the present invention is to use the hollow-proof reactor, by adjusting the composition ratio of the monomer to be filled in the reactor or by adjusting the rotational speed of the rotary reactor in accordance with the degree of polymerization of the polymer, such as in the radial and longitudinal directions It is to provide a method for producing a base material for plastic optical fibers in which the refractive index gradient is adjusted.

That is, one aspect of the present invention (a) an input having a reactant inlet for introducing a reactant into the entire reactor; (b) a reaction part positioned between the input part and the blocking wall and having a flow path communicating with the input part in the center of the blocking wall; And (c) is installed between the flow path of the reaction part and the reactant inlet of the input part so that hollows generated from the reactant inlet space of the input part during the rotation of the reactor do not continue to the reaction part, and allows the reactant of the input part to flow into the reaction part, or A hollow anti-reactor comprising one or more hollow blocking structures, having two or more flow paths.

Another aspect of the present invention is a method for manufacturing a base material for plastic optical fiber using the hollow-prevention reactor, the method comprising the steps of: (a) filling the reactant and the inlet of the reactor; And (b) polymerizing the reactant of the reaction unit while rotating the reactor.

1 is a perspective view showing an example of a hollow prevention reactor designed according to the present invention,

2 is a flow chart showing the operating principle of the hollow-proof reactor of the present invention,

3 (a) and 3 (b) is a cross-sectional view showing a hollow anti-reactor of the modified form,

4 is a cross-sectional view showing a state in which a hollow is formed when using a general rotary reactor,

5 is a schematic view showing a case where the reaction is inclined to the reactor,

6 is a cross-sectional view showing an example of an apparatus for simultaneously pressurizing the inside and the outside of a hollow prevention reactor; and

Fig. 7 is a cross-sectional view showing the form of a reaction apparatus in the case of using a UV initiator.

Hereinafter, the present invention will be described in more detail with reference to the drawings.

Figure 1 is a perspective view showing an embodiment of the hollow anti-reactor of the present invention, the entire reactor is in the form of a circular reactor, divided into the input unit 10 and the reaction unit 20. The input unit 10 includes a reactant inlet 11 for introducing a reactant into the entire reactor, and the reaction unit 20 includes a flow path 21 for introducing the reactant from the input unit to the reaction unit 20. Doing. Between the reactant inlet 11 of the input unit 10 and the flow passage 21 of the reaction unit 20, a blocking wall 32 and a hollow blocking structure 30 separating the input unit and the reaction unit are installed to rotate the entire reactor. The hollow generated in the space of the reactant inlet 11 under the rotation generated at the time is prevented from continuing to the reaction part 20. The hollow blocking structure 30 is provided with a flow path 31 to allow reactants on the upper portion of the hollow blocking structure to flow into the reaction unit 20 through the hollow blocking structure 30.

FIG. 2 is a flowchart illustrating a principle in which hollows are prevented in a reaction unit when the reaction is performed under rotation using the hollow-type reactor of FIG. 1. When the entire reactor starts to rotate, hollows are generated from the unfilled space of the input. However, the generated hollow is blocked by the hollow blocking structure as shown in the drawing and cannot continue to the main reaction part. As the reactor continues to rotate, polymerization of the reaction unit proceeds, resulting in volume shrinkage, but the hollow of the inlet becomes large due to the flow of reactants from the inlet as much as the volume shrinkage, and no hollow is formed in the reaction unit. In this case, it is preferable to pressurize the empty space of the input part with a high pressure inert gas or the like to help the reactants of the input part flow into the reaction part.

Such a hollow prevention reactor is not limited to the reactor disclosed in FIG. 1, but blocks any hollows generated in the input unit from being continued to the reaction unit, and any role of the reaction agent may flow into the reaction unit. Also available. For example, not only the reaction part and the input part are formed to form a linear reactor as shown in FIG. 1, but also a reactor having a different diameter of the reactor constituting the reaction part and the diameter of the reactor constituting the input part may be used. In addition, the shape of the hollow block structure, as well as the cylindrical shape as described above can be plate-shaped, the number of hollow block structure can also be installed in two or more, the input section is located at the top and the reaction section is located at the bottom It is also possible to reverse the shape, or the reaction part is centered on the axis of rotation and the input part surrounds it.

3 shows a modification of the hollow-proof reactor of the present invention. FIG. 3 (a) shows a reactor in the case where two hollow blocking structures of the same structure as in FIG. 1 are installed, and FIG. 3 (b) shows a plate-shaped hollow blocking structure between the reactant inlet of the inlet and the passage of the reaction section. In this case, a plurality of flow paths are provided in the outer shell.

The above embodiments are not intended to limit the hollow prevention reactor of the present invention.

Hereinafter, a method of manufacturing a base material for plastic optical fiber using a hollow prevention reactor will be described.

The base material for plastic optical fibers of the present invention is prepared by a method of introducing a reactant into the above hollow prevention reactor, and then polymerizing the reactant in the reaction section under rotation of the reactor. At this time, in order to control the refractive index distribution in the radial direction of the plastic optical fiber base material to be manufactured, it is possible to control the composition of the reactants, the rotational speed of the reactor and the like filled in the reaction unit and the input unit.

More specifically, a method of manufacturing a base material for plastic optical fiber using the hollow-prevention reactor has the following aspects. Unless otherwise specified in the following embodiments, the monomer or monomer mixture refers to a monomer mixture capable of polymerization reaction by adding a thermal initiator and a molecular weight regulator.

In the first aspect of the present invention is characterized in that the refractive index is different by varying the composition ratio of the monomer mixture filling the reaction section and the input section. First, two or more kinds of mixtures having different composition ratios are prepared using two or more kinds of monomers having different refractive indices. Next, after filling the monomer mixture having a low refractive index in the reaction part of the reactor, and filling the monomer mixture having the high refractive index in the input part, the monomer mixture of the reaction part is polymerized while shifting or constant-rotating the reactor. At this time, even if the reaction proceeds in the reaction part and volume shrinkage occurs, since the monomer mixture having high refractive index filled in the input part flows into the center of the reaction part, volume shrinkage occurs only at the input part side, and the refractive index of the center of the reaction part becomes high. . This volumetric shrinkage process occurs after the polymerization has been considerably progressed, so that the monomer mixture of the inlet portion introduced into the center of the reaction portion diffuses radially into the polymer or oligomer and exhibits a continuous refractive index gradient. Therefore, when the polymerization of the reaction part is completely terminated, it is possible to obtain a base material for the plastic optical fiber which has a continuous refractive index gradient in the radial direction and has no hollow.

According to a second aspect of the present invention, the reaction portion and the input portion are filled with a monomer mixture having the same composition. In this case, after preparing a mixture of a low refractive index and high density monomer and a high refractive index and low density monomer, the mixture is filled in the reaction part and the input part of the hollow prevention reactor. The reactor thus filled is mounted in a rotary reaction apparatus and polymerized by applying heat to the reaction unit without initially rotating. After the polymerization is carried out to some extent, if the polymerization is continued while the reactor is rotated at constant speed or speed, it is possible to obtain a base material for the plastic optical fiber which has a continuous refractive index gradient in the radial direction and has no hollow. In this embodiment, even if the composition of the monomer mixture of the reaction section and the input section is the same, a monomer having a high density and a low refractive index diffuses to the outer shell under the influence of rotation, and thus the refractive index is lower at the outer shell and the refractive index becomes higher as it comes to the center. The base material for plastic optical fibers which have a refractive index gradient can be manufactured.

According to a third aspect of the present invention, a part of the reactant is added to the reaction part to form a clad part first, and then form a core part. First, only a part of the reaction part of the reactor is filled using a mixture having a composition having a low refractive index, and then polymerization is performed while rotating the reactor at constant speed, thereby forming a clad part having a desired thickness on the reaction part. When the cladding part is completely polymerized and vitrified, as in the first or second embodiment, the reaction part and the inlet part are filled with a monomer mixture having the same or different composition and polymerized under a variable speed or constant speed rotation so that the refractive index is continuous in the radial direction. It is possible to obtain a base material for plastic optical fibers having a distribution and preventing hollow formation.

According to a fourth aspect of the present invention, a polymer having a lower refractive index than that of the monomer mixture is polymerized separately and dissolved in the monomer mixture, followed by filling the reaction portion and the input portion to proceed with the reaction. When the mixture of the monomer and the polymer is placed in a hollow prevention reactor and rotated to polymerize, a polymer component having a relatively higher density than that of the monomer mixture is concentrated on the outer shell to form a cladding portion. Therefore, in the present embodiment, by using the monomer mixture in which the polymer is dissolved, it is possible to form a clad part even in a single feeding process, reduce heat generation during polymerization, and provide a stable base material manufacturing process by reducing volume shrinkage. There is an advantage. In the present aspect, as in the first or second aspect, the reaction and input portions are filled with monomer mixtures having the same or different composition, and are polymerized under a variable speed or constant speed rotation to have a continuous refractive index distribution in the radial direction. The base material for plastic optical fiber in which formation was prevented can be obtained.

In a fifth aspect of the present invention, the prepolymer component is used in combination with the monomer mixture. First, a prepolymer having a lower refractive index than the monomer mixture is prepared. After the prepared prepolymer component is mixed with the monomer mixture to fill the reaction part and the inlet part, or without mixing with the monomer mixture, the reactor is filled by filling only part of the reaction part using only the prepolymer and filling the monomer mixture thereon, and then constant or shifting Polymerization while rotating to obtain a base material for a plastic optical fiber without a hollow having a continuous refractive index distribution in the radial direction. In this case, too, the composition ratio of the mixture filling the input part and the reaction part can be adjusted differently. In this case, the viscosity of the prepolymer is preferably 500 to 500,000 cps (25 ° C), and more preferably 1,000 to 10,000 cps (25 ° C). If the viscosity is less than 500cps it is difficult to obtain the effect of the prepolymer addition, if it exceeds 500,000 because the viscosity is too high a lot of bubbles, the dosing time is long and stability and reproducibility can not be guaranteed.

Even when the prepolymer is added as described above, the cladding portion can be formed in a single feeding process as in the fourth embodiment used by dissolving the polymerized polymer, the heat generation during the polymerization can be reduced, and the volume shrinkage is stable. There is an effect that can provide a base material manufacturing process.

In a sixth aspect of the present invention, the reaction is performed by tilting the reactor at 0 to 180 degrees with respect to the gravity direction in order to remove the refractive index gradient in the longitudinal direction of the base material caused by the influence of gravity.

4 is a cross-sectional view showing a state in which a hollow is formed in a general rotary reactor. In the case of the hollow-proof reactor, when the monomer initially filled in the reaction part reacts, there is a volume shrinkage, so considering the virtual meniscus shape of the reaction part, the amount of reactant flowing from the input part to the reaction part can be predicted. It can be a rough reference for the appearance of the distribution, and can also be used as a reference for the uniformity of the refractive index gradient formed in the longitudinal direction of the base material. The hollow shape formed in the reactor is represented by Equation 1.

Where Ω is the rotational speed, g is the gravitational constant (approximately 9.8 m / s ² ), and z ₀ corresponds to the height of the meniscus at the bottom of the reactor, assuming a hypothetical meniscus has developed to the bottom of the reactor. Is a value.

Assuming there was 20% volumetric shrinkage, even if the reactor was initially filled with the monomer mixture And the radii r ₁ and r ₂ at z = 0 and z = L 'are as shown in Equation 2.

,

Using the radii r ₁ and r ₂ shown in Equation 2, for example, the difference between the upper and lower ends of the hollow reactor, which is virtually generated, is 1% or less of the total radius (r ₂ -r ₁ <0.01 R). When calculating the condition to be as follows.

As shown in Equation 3, the higher the rotational speed, the more advantageous it is to obtain the uniformity of the refractive index gradient in the longitudinal direction, but the uniformity of the refractive index in the longitudinal direction can be obtained even by reducing the height L ' with respect to the gravity direction. . To reduce the height L ' in the direction of gravity, there is a method in which the reactor is inclined as shown in FIG. 5, where the smaller the angle θ is, the smaller L' becomes and thus the refractive index gradient in the longitudinal direction of the base material is uniform without limiting the rotational speed. It can be done.

In all embodiments of the present invention, the formation of the hollow due to the volume shrinkage that occurs as the polymerization proceeds occurs only at the input portion, and the volume of the reactant filled in the input portion is formed at the time of the completion of the volume shrinkage. The diameter should be adjusted to be smaller than the diameter of the hollow block structure. Only then, the hollow enlarged at the inlet part during the volume shrinkage passes the hollow blocking structure to prevent the hollow from entering the reaction part.

On the other hand, pressurizing an inert gas such as argon in the empty space of the reactor helps inflow of the reactants from the reactor to the reactor, thus preventing the formation of hollows in the reactor and allowing the polymerization to proceed stably. By increasing the boiling point of the sample monomer, the reaction can be carried out at high temperatures, which shortens the reaction time and prevents the formation of unreacted substances, thereby preventing the formation of bubbles. In this case, when the hollow protection reactor is formed of a fragile material such as glass, quartz, ceramic or plastic, it is difficult to pressurize the inside of the reactor to 4 bar or more due to its breakage possibility. In this case, by pressurizing the outside of the hollow prevention reactor in the same manner, the degree of pressurization may be increased to about 10 bar.

Fig. 6 shows an example of a device that can pressurize both the inside and outside of the hollow anti-reactor reactor at the same time. Connect the argon gas cylinder through the quick connector (1) located in the upper part of the rotary reaction device for pressurization, and then lift the argon gas through the pressurizing furnace (3) while lifting the stopper (2) to adjust the height. At the same time, pressurize the inside of the hollow protection reactor (5) and the inside of the reactor (6) at the same time, and then press down the stopper to press the O-ring (4). It is a structure made up.

In the present invention, in principle, the hollow part is not formed in the reaction part due to the volume contraction, but due to the nature of the radical reaction, there is some vaporization of the monomer due to the exotherm. When this occurs in the reaction part, the vaporized bubbles of the monomer are hollowed out by rotation. There may be cases. As mentioned above, pressurizing the input unit and shifting the rotation is advantageous to produce a base material without forming a hollow out of the bubble toward the input unit.

In all embodiments of the present invention, the polymerization of the reaction unit may be performed by thermal polymerization or UV polymerization. 7 is a cross-sectional view showing the concept of carrying out the reaction using UV polymerization. When using UV polymerization, a photoinitiator is used instead of a thermal polymerization initiator as a reaction initiator. When UV is used, it is not necessary to increase the temperature of the reactor, so the possibility of hollow formation by the vaporization of the monomer is much lower, and since UV is irradiated only to the reaction part, the reactant of the input part is vitrified during the volume shrinkage of the reaction part to supply the reactant. Since there is no clogging phenomenon, a method of manufacturing a more stable base material for plastic optical fibers can be provided.

In all of the above embodiments of the present invention, various changes can be made to the rotational speed of the reactor in order to induce a better refractive index distribution, such as triangular functions varying in amplitude and period as well as simple repetition of rotation and stop. You can have a speed function.

In general, in order to facilitate heat transfer for the polymerization reaction, it is appropriate to set the radius of the base material to about 1 to 10 cm, and the length of the base material to be within about 100 cm so as to be suitable for a normal thermal drawing process. .

Two monomers having different refractive indices used in the present invention are specifically methyl methacrylate, benzyl methacrylate, phenyl methacrylate, 1-methylcyclohexyl methacrylate, cyclohexyl methacrylate, chlorobenzyl methacrylate. , 1-phenylethyl methacrylate, 1,2-diphenylethyl methacrylate, diphenylmethyl methacrylate, perfuryl methacrylate, 1-phenylcyclohexyl methacrylate, pentachlorophenyl methacrylate, penta Bromophenyl methacrylate, styrene, TFEMA (2,2,2-trifluoroethyl methacrylate), PFPMA (2,2,3,3,3-pentafluoropropylmethacrylate), HFIPMA (1 , 1,1,3,3,3-hexafluoroisomethacrylate) and HFBMA (2,2,3,3,4,4,4-heptafluorobutylmethacrylate) It may be, but is not limited to such.

In addition, a homopolymer or a copolymer may be used as the polymer to be introduced when the base material is manufactured in the fourth aspect of the present invention. Such homopolymers specifically include methyl methacrylate, benzyl methacrylate, phenyl methacrylate, 1-methylcyclohexyl methacrylate, cyclohexyl methacrylate, chlorobenzyl methacrylate and 1-phenylethyl methacrylate. Acrylate, 1,2-diphenylethyl methacrylate, diphenylmethyl methacrylate, perfuryl methacrylate, 1-phenylcyclohexyl methacrylate, pentachlorophenyl methacrylate, pentabromophenyl methacrylate , Styrene, TFEMA (2,2,2-trifluoroethylmethacrylate), PFPMA (2,2,3,3,3-pentafluoropropylmethacrylate), HFIPMA (1,1,1,3 Homopolymer of one monomer selected from the group consisting of 3,3-hexafluoroisomethacrylate) and HFBMA (2,2,3,3,4,4,4-heptafluorobutylmethacrylate) It may include, but is not limited to. In addition, the copolymer is specifically methyl methacrylate (MMA) -benzyl methacrylate (BMA) copolymer, styrene-acrylonitrile copolymer (SAN), MMA-TFEMA (2,2,2-trifluoro Low ethyl methacrylate) copolymer, MMA-PFPMA (2,2,3,3,3-pentafluoropropyl methacrylate) copolymer, MMA-HFIPMA (1,1,1,3,3,3- Hexafluoroisomethacrylate) copolymer, MMA-HFBMA (2,2,3,3,4,4,4-heptafluorobutylmethacrylate) copolymer, TFEMA-PFPMA copolymer, TFEMA-HFIPMA air Copolymers selected from the group consisting of copolymers, styrene-methylmethacrylate (SM) copolymers, and TFEMA-HFBMA copolymers, but are not limited thereto.

In addition, in the fifth aspect of the present invention, a compatible prepolymer may be specifically methyl methacrylate, benzyl methacrylate, phenyl methacrylate, 1-methylcyclohexyl methacrylate, cyclohexyl methacrylate, or chlorobenzyl. Methacrylate, 1-phenylethyl methacrylate, 1,2-diphenylethyl methacrylate, diphenylmethyl methacrylate, perfuryl methacrylate, 1-phenylcyclohexyl methacrylate, pentachlorophenyl methacrylate Latex, pentabromophenyl methacrylate, styrene, TFEMA (2,2,2-trifluoroethyl methacrylate), PFPMA (2,2,3,3,3-pentafluoropropyl methacrylate), Consisting of HFIPMA (1,1,1,3,3,3-hexafluoroisomethacrylate), and HFBMA (2,2,3,3,4,4,4-heptafluorobutylmethacrylate) Copolymers made from two or more monomers selected from the group. And it not limited to this.

In addition, the thermal polymerization initiator to be polymerized in the present invention is specifically 2,2'- azo-bis (isobutyronitrile) (2,2'-azo-bis (isobutyronitrile)), 1,1 '-Azo-bis (cyclohexanecarbonitrile) (1,1'-azo-bis (cyclohexanecarbonitrile), di-tert-butyl peroxide, lauroylperoxide , Benzoyl peroxide, tert-butylperoxide, azo-tert-butane, azo-bis-isopropyl, azo-normal- One or more materials selected from the group consisting of butane (azo-n-butane) and di-tert-butyl peroxide (di-tert-peroxide) may be used, but are not limited thereto.

In addition, the photopolymerization initiator introduced to polymerize the monomer in the present invention is specifically 4- (para-tolylthio) benzophenone (4- (p-tolylthio) benzophenone), 4,4'-bis (dimethylamino) Benzophenone (4,4'-bis (dimethylamino) benzophenone), 2-methyl-4 '-(methylthio) -2-morpholino-propiophenone 2-methyl-4'-(methylthio) -2-morpholino One or more substances selected from the group consisting of -propiophenone may be used, but are not limited thereto.

In addition, the molecular weight regulator (chain transfer agent) added to the monomer mixture in the present invention is composed of a normal-butyl- mercaptan (n-butyl mercaptan), lauryl mercaptan (lauryl mercaptan), dodecyl mercaptan (dodesyl mercaptan) One or more materials selected from the group may be used, but the present invention is not limited thereto.

The base material for the plastic optical fiber manufactured according to the manufacturing method may be converted into a refractive index distributed plastic optical fiber having a desired diameter through a process of thermal drawing as needed, and made into a rod shape having a relatively thick diameter. It can also be applied as a refractive index distribution lens and an image guide for image transmission.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the following Examples are intended to illustrate the present invention and are not intended to limit the present invention.

Example

As the hollow-prevention reactor used in the embodiment as shown in FIG. 1, a circular reactor having a diameter of 40 mm, a height of an upper input part of 100 mm, and a height of a lower reaction part of 120 mm was used. The reaction solution is a binary component of a monomer having different densities and refractive indices, or a pair of more than three minutes, styrene monomer (SM), methyl methacrylate (MMA), and trifluoroethyl methacrylate. (trifluoroethyl methacrylate: TFEMA) was used. 2,2'-azobis isobutyronitrile (hereinafter referred to as AIBN) was used as the thermal polymerization initiator in the MMA-SM reaction, and tert-butyl peroxybenzoate (tert-butyl peroxybenzoate: T-BPOB) was used for the MMA-TFEMA reaction, and 1-butanethiol (1-butanethiol: 1-BuSH) was used as a molecular weight regulator. When using a photoinitiation reaction by UV, 4,4'- dimethylamino benzophenone (4,4'-bis (dimethylamino) benzophenone: DMABP) was used as a photoinitiator.

In the present invention, the optical loss of the plastic optical fiber was measured by using an optical power meter of a 660 nm light source with a 1 mm thick optical fiber.

Example 1:

150g of a monomer mixture in which SM and MMA were mixed at a weight ratio of 20:80 were prepared so that AIBN and 1-BuSH were mixed at a concentration of 0.066% by weight and 0.2% by weight, respectively. Filled with wealth Next, 110 g of the monomer mixture containing SM and MMA at a weight ratio of 40:60 and a solution containing AIBN and 1-BuSH at a concentration of 0.066 wt% and 0.2 wt%, respectively, were added to the top feeder to a height of 85 mm. It was. In the empty space of the input section, 99.999% argon gas was pressurized and filled with 1 bar, and the stopper was closed. After 12 hours, the reactor was heated to 70 ° C at a rotational speed of 2,500rpm, and the reaction proceeded for 5 minutes after 12 hours. Dozens of times of shifting the rotation was stopped and rotated at 2,500 rpm for 10 minutes. Finally, the base material for the plastic optical fiber without hollow was prepared. The optical loss measured using an optical power meter was 300 dB / km.

Example 2:

A reaction mixture at the bottom of the hollow-proof reactor was prepared by preparing a solution in which 260 g of SM and MMA were mixed at a weight ratio of 30:70 by mixing AIBN and 1-BuSH at a concentration of 0.066 wt% and 0.2 wt%, respectively. Filled to a height of up to 85 mm at the top. In the empty space of the input section, 99.999% of argon gas was pressurized and filled with 1 bar, and the stopper was closed. After 12 hours, the reactor was heated to 70 ° C at a rotational speed of 2,500 rpm, and the reaction proceeded for 5 minutes after 12 hours. Dozens of times of shifting the rotation was stopped and rotated at 2,500 rpm for 10 minutes. Finally, the base material for the plastic optical fiber without hollow was prepared. The optical loss measured using an optical power meter was 300 dB / km.

Example 3:

A solution of AIBN and 1-BuSH was mixed in 50 g of MMA so as to have a concentration of 0.066% by weight and 0.2% by weight, respectively.Then, the reaction solution was filled in a hollow-proof reactor to a height of up to 40 mm in the lower reaction part, followed by argon The gas was charged and reacted at a rotational speed of 2,500 rpm and a temperature of 70 ° C. for 12 hours to form a clad layer. Next, the mixed solution of AIBN and 1-BuSH in a concentration of 0.066% by weight and 0.2% by weight was added to 110 g of the monomer mixture in which the SM and MMA were mixed at a weight ratio of 20:80. In addition, 110 g of the monomer mixture in which SM and MMA were mixed at a weight ratio of 40:60 were mixed with AIBN and 1-BuSH at a concentration of 0.066% by weight and 0.2% by weight, respectively. The feeder was fed up to a height of 85mm. In the empty space of the input section, 99.999% of argon gas was pressurized and filled with 1 bar, and the stopper was closed. After 12 hours, the reactor was heated at 70 ° C at a rotation speed of 2500rpm, and the reaction was stopped for 5 minutes after 12 hours. 10 minutes was repeated repeatedly applying a variable speed of rotation to 2500rpm. Finally, the base material for the plastic optical fiber without hollow was prepared. The optical loss measured using an optical power meter was 260 dB / km.

Example 4:

A polymer obtained by mixing AIBN and 1-BuSH in a concentration of 0.066% by weight and 0.2% by weight in 50 g of MMA was polymerized for 24 hours at 70 ° C, and SM and MMA were mixed in a weight ratio of 20:80. To 110 g of the mixed monomer mixture, AIBN and 1-BuSH were dissolved in a mixed solution at a concentration of 0.066 wt% and 0.2 wt%, respectively, and then charged to fill the reaction part. Then, a mixture of A and N-BuSH was mixed with 110 g of a monomer mixture containing SM and MMA at a weight ratio of 40:60 to 0.066% by weight and 0.2% by weight, respectively. Input to height. In the empty space of the input section, 99.999% of argon gas was pressurized and filled with 1 bar, and the stopper was closed. After 12 hours, the reactor was heated to 70 ° C at a rotational speed of 2,500 rpm, and the reaction proceeded for 5 minutes after 12 hours. Dozens of times of shifting the rotation was stopped and rotated at 2,500 rpm for 10 minutes. In this way, the base material for the plastic fiber without hollow was finally produced. The optical loss measured using an optical power meter was 250 dB / km.

Example 5:

A solution prepared by mixing AIBN and 1-BuSH in a concentration of 0.066% by weight and 0.2% by weight in 50 g of MMA was polymerized at 4 ° C. for 4 hours. , 110 g of SM and MMA were mixed at a weight ratio of 20:80 to 110g of AIBN and 1-BuSH, respectively. Then, a solution of AIBN and 1-BuSH mixed at a concentration of 0.066% by weight and 0.2% by weight was added to 110 g of the monomer mixture in which SM and MMA were mixed at a weight ratio of 40:60, respectively. In the empty space of the input section, 99.999% of argon gas was pressurized and filled with 1 bar, and the stopper was closed. After 9 hours, the reactor was heated to 70 ° C at a rotational speed of 2,500 rpm, and the reaction proceeded for 5 minutes after 9 hours. Dozens of times of shifting the rotation was stopped and rotated at 2,500 rpm for 10 minutes. Finally, the base material for the plastic optical fiber without hollow was prepared. The optical loss measured using an optical power meter was 230 dB / km.

Example 6:

A solution in which AIBN and 1-BuSH were mixed at a concentration of 0.066 wt% and 0.2 wt%, respectively, was prepared in 260 g of a monomer mixture in which SM and MMA were mixed at a weight ratio of 30:70. The reaction solution was added to the hollow-proof reactor to fill the reaction part at the bottom, and then the top input part was added at a time up to a height of 85 mm. The empty space of the inlet was pressurized with 99.999% of argon gas to 1 bar. After the reactor was inclined at an angle of 105 degrees (15 degrees to the ground) with respect to the gravity direction, the reaction was heated to 70 ° C. at a rotation speed of 1,000 rpm for 12 hours, and then stopped for 5 minutes after 12 hours. For several minutes, a variable speed rotation of rotating at 1,000 rpm was applied repeatedly. This manufacturing method finally produced a base material for plastic optical fiber without hollow. The optical loss measured using an optical power meter was 290 dB / km.

Example 7:

To 260 g of a monomer mixture in which SM and MMA were mixed at a weight ratio of 30:70, a solution was prepared in which DMABP and 1-BuSH were mixed at a concentration of 0.066 wt% and 0.2 wt%, respectively. The reaction solution was introduced into the hollow-proof reactor, and the reaction part and the upper input part of the reactor were put at a height of 85 mm at one time, and 99.999% of argon gas was charged to 1 bar into the empty space of the input part. Using the UV irradiation apparatus of the form as shown in Figure 6 to heat the hollow-prevention reactor at 40 ℃ at a rotational speed of 2,500rpm for 12 hours while proceeding the reaction while irradiating UV and after 12 hours stopped for 5 minutes 10 minutes was applied repeatedly a dozen times of variable speed rotation to rotate at 2,500rpm. This manufacturing method finally produced a base material for plastic optical fiber without hollow. The optical loss measured using an optical power meter was 300 dB / km.

Example 8:

Prepare a solution of t-BPOB and 1-BuSH mixed at a concentration of 0.066 wt% and 0.25 wt% to 170 g of a monomer mixture in which MMA and TFEMA are mixed at a weight ratio of 70:30, respectively, The reaction solution was added to the lower reaction part only and the stopper was closed. After stopping the reaction for 12 hours at a temperature of 70 ° C., the reaction solution was rotated at 2,500 rpm for 12 hours at a temperature of 70 ° C. to form a clad layer. . Then, 150 g of a monomer mixture in which MMA and TFEMA were mixed at a weight ratio of 90: 10 was heated to 70 ° C. in a solution mixed with t-BPOB and 1-BuSH so as to have a concentration of 0.066 wt% and 0.25 wt%, respectively. First, the solution was mixed with t-BPOB and 1-BuSH in a concentration of 0.066 wt% and 0.2 wt%, respectively, in 120 g of MMA. In the empty space of the input section, 99.999% of argon gas was pressurized and filled with 1 bar, and the stopper was closed. After 12 hours, the reactor was heated to 70 ° C at a rotational speed of 2,500 rpm, and the reaction proceeded for 5 minutes after 12 hours. Dozens of times of shifting the rotation was stopped and rotated at 2,500 rpm for 10 minutes. Finally, the base material for the plastic optical fiber without hollow was prepared. The optical loss measured using an optical power meter was 150 dB / km.

Example VII:

150 g of a monomer mixture containing SM and MMA in a weight ratio of 10: 0 was prepared to prepare a solution in which AIBN and 1-BuSH were mixed at a concentration of 0.066 wt% and 0.2 wt%, respectively, and then reacted at the bottom of the reactor. Filled with wealth Next, a solution of AIBN and 1-BuSH was mixed in a concentration of 0.066% by weight and 0.2% by weight to 110g of a monomer mixture containing SM and MMA in a weight ratio of 20:80, respectively. It was. The above hollow anti-reactor was mounted on the rotary reaction device shown in Fig. 6, and the stopper of the rotary device was closed. Then, the empty space of the hollow anti-reactor reactor and the inside of the rotary reactor were pressurized with argon gas of 10 bar for 4 hours. The reaction proceeded by heating to 110 ° C. at a rotational speed of 2,500 rpm. After 4 hours, the temperature was lowered to 90 ° C., the temperature was lowered to 90 ° C., stopped for 5 minutes, and rotated at 10,500 rpm for 10 minutes. After several hours, the manufacturing method finally yielded a base material for plastic optical fiber without hollow. The optical loss measured using an optical power meter was 250 dB / km.

Since SM and MMA have similar relative reactivity, the obtained base material was an amorphous random copolymer, and in the case of TFEMA and MMA, although the reactivity was high in MMA, the amorphous amorphous copolymer was transparent in the composition ratio of all the above-mentioned areas. Was obtained.

Addition of the reactant to the base material for the plastic optical fiber having a continuous refractive index gradient along the radial direction by preventing the generation of hollow due to volume shrinkage during the production of the base material for the plastic optical fiber under rotation by using the hollow-proof reactor according to the present invention It provides a new way to manufacture without a process.

Claims (21)

(a) an input having a reactant inlet for introducing the reactant throughout the reactor; (b) a reaction part positioned between the input part and the blocking wall and having a flow path communicating with the input part in the center of the blocking wall; And (c) one or two installed between the flow path of the reaction part and the reactant inlet of the input part so that the hollows generated from the reactant inlet space of the input part during the rotation of the reactor do not continue to the reaction part, and the reactants of the input part can flow into the reaction part; An anti-hollow reactor comprising one or more hollow blocking structures, having more than one flow path. The method of claim 1, wherein the hollow block structure is a hollow prevention reactor, characterized in that the cylindrical or plate-shaped. 2. The anti-barrel reactor of claim 1, wherein the reactor is made of glass, quartz, ceramic or plastic. The method of claim 1, wherein the diameter of the reactor is 1 ~ 10cm, the length of the reactor is a hollow prevention reactor, characterized in that less than 100cm. In the method for producing a base material for plastic optical fiber using the reactor of claim 1, (a) filling a reactant and an input into the reactor; And (B) a method of manufacturing a base material for plastic optical fiber comprising the step of polymerizing the reactants of the reaction portion while rotating the reactor. The method of manufacturing a base material for plastic optical fibers according to claim 5, wherein the inert gas is filled and pressurized into a space in which the reactants of the input part are not filled. The method of manufacturing a base material for plastic optical fiber according to claim 6, wherein the inside of the reactor and the outside of the reactor are simultaneously pressed. The method of manufacturing a base material for plastic optical fiber according to claim 5, wherein the reactor is rotated at a constant speed or a variable speed. 9. The method of claim 8, wherein the variable speed rotation of the reactor follows a rotational speed function having a form of repeating a high speed rotation and a low speed rotation or a stationary state, a triangular function form, or a specific function form in which the period, phase and amplitude change. Method for manufacturing a base material for plastic optical fiber The method of claim 5, wherein the reactant is a mixture of two or more monomers having different refractive indices, a polymerization initiator, and a molecular weight modifier. The method of claim 10, wherein the reactant is a mixture of a high refractive index and low density monomer, a low refractive index and high density monomer, a polymerization initiator and a molecular weight regulator, the monomer mixture is equally filled The manufacturing method of the base material for plastic optical fibers characterized by the above-mentioned. The method of manufacturing a base material for plastic optical fiber according to claim 10, wherein the refractive index of the monomer mixture filled in the input portion is higher than that of the monomer mixture filled in the reaction portion. The method of manufacturing a base material for plastic optical fibers according to claim 10, wherein a fragment of a polymer having a lower refractive index than that of the mixture is swelled or dissolved in the monomer mixture filled in the reaction part. The base material for plastic optical fibers according to claim 10, wherein the monomer mixture filled in the reaction part is mixed with a prepolymer having a lower refractive index than the mixture, or the prepolymer having a low refractive index is filled in advance with the reaction part and then the monomer mixture is filled. Way. The method of claim 10, wherein the monomer is methyl methacrylate, benzyl methacrylate, phenyl methacrylate, 1-methylcyclohexyl methacrylate, cyclohexyl methacrylate, chlorobenzyl methacrylate, 1-phenylethyl methacrylate Late, 1,2-diphenylethyl methacrylate, diphenylmethyl methacrylate, perfuryl methacrylate, 1-phenylcyclohexyl methacrylate, pentachlorophenyl methacrylate, pentabromophenyl methacrylate, Styrene, TFEMA (2,2,2-trifluoroethylmethacrylate), PFPMA (2,2,3,3,3-pentafluoropropylmethacrylate), HFIPMA (1,1,1,3, 3,3-hexafluoroisomethacrylate) and HFBMA (2,2,3,3,4,4,4-heptafluorobutylmethacrylate), each of which is selected from the group consisting of plastic optical fibers Method for producing the base metal. The method of claim 13, wherein the polymer is methyl methacrylate, benzyl methacrylate, phenyl methacrylate, 1-methylcyclohexyl methacrylate, cyclohexyl methacrylate, chlorobenzyl methacrylate, 1-phenylethyl methacrylate Acrylate, 1,2-diphenylethyl methacrylate, diphenylmethyl methacrylate, perfuryl methacrylate, 1-phenylcyclohexyl methacrylate, pentachlorophenyl methacrylate, pentabromophenyl methacrylate , Styrene, TFEMA (2,2,2-trifluoroethylmethacrylate), PFPMA (2,2,3,3,3-pentafluoropropylmethacrylate), HFIPMA (1,1,1,3 , 3,3-hexafluoroisomethacrylate) and HFBMA (2,2,3,3,4,4,4-heptafluorobutylmethacrylate), characterized in that it is a homopolymer of monomers selected from the group consisting of Method for producing a base material for plastic optical fibers. The method of claim 13, wherein the polymer is methyl methacrylate (MMA) -benzyl methacrylate (BMA) copolymer, styrene-acrylonitrile copolymer (SAN), MMA-TFEMA (2,2,2-trifluoro Low ethyl methacrylate) copolymer, MMA-PFPMA (2,2,3,3,3-pentafluoropropyl methacrylate) copolymer, MMA-HFIPMA (1,1,1,3,3,3- Hexafluoroisomethacrylate) copolymer, MMA-HFBMA (2,2,3,3,4,4,4-heptafluorobutylmethacrylate) copolymer, TFEMA-PFPMA copolymer, TFEMA-HFIPMA air Method for producing a base material for plastic optical fibers, characterized in that the copolymer selected from the group consisting of a copolymer, a styrene-methyl methacrylate copolymer and a TFEMA-HFBMA copolymer. The method according to claim 14, wherein the prepolymer is methyl methacrylate, benzyl methacrylate, phenyl methacrylate, 1-methylcyclohexyl methacrylate, cyclohexyl methacrylate, chlorobenzyl methacrylate, 1-phenylethyl methacrylate. Acrylate, 1,2-diphenylethyl methacrylate, diphenylmethyl methacrylate, perfuryl methacrylate, 1-phenylcyclohexyl methacrylate, pentachlorophenyl methacrylate, pentabromophenyl methacrylate , Styrene and TFEMA (2,2,2-trifluoroethylmethacrylate), PFPMA (2,2,3,3,3-pentafluoropropylmethacrylate), HFIPMA (1,1,1,3 , 3,3-hexafluoroisomethacrylate) and HFBMA (2,2,3,3,4,4,4-heptafluorobutylmethacrylate) from a single or two or more monomers selected from the group consisting of For plastic optical fibers, characterized in that the made prepolymer How material produced. 15. The method of claim 14, wherein the prepolymer has a viscosity of 500 to 500,000 cps (25 ° C). The method of claim 5, wherein the mixture of the reaction unit is thermally polymerized or UV polymerized. The method of manufacturing a base material for plastic optical fiber according to claim 5, wherein the reactor is reacted by tilting the reactor in a range of 0 to 180 degrees with respect to the direction of gravity.