JP2889136B2 - Method for producing composite monofilament for light / image transmission and composite monofilament produced by the method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a composite monofilament for light / image transmission by extrusion processing (hereinafter sometimes referred to as a polymer material column for light / image transmission), and more particularly to a method for producing a different refractive index. Polymer solution containing two monomers having different refractive indices is extruded through a mold such that the monomers diffuse into each other in the diffusion region to form a polymer material column having a continuous refractive index distribution. The present invention relates to a method for producing a polymer material column for light / image transmission and a polymer column for light / image transmission produced by the method.

[0002]

2. Description of the Related Art An optical transmission column having a continuous refractive index distribution from the surface layer toward the center of the column (here, the column means a monofilament or a composite monofilament, the same applies hereinafter) is made of glass in other places. I have been. However, this type of optical transmission column has a very low production rate and a very high cost in production. Glass optical transmission columns also have the problem of poor flexibility for use in various applications. This type of glass light transmission column is disclosed in Japanese Patent Application Laid-Open No. 47-816.
No. 6,086,045.

Others have proposed a method of manufacturing an optical transmission column having a continuous refractive index distribution from the surface layer toward the center of the column using a polymer material. One such method is to continuously change the concentration of metal ions from the center of the column to the surface so as to obtain a polymer material light transmission column having a continuous refractive index distribution from the surface toward the center of the column. A synthetic resin filament is manufactured by graft polymerization. Such a method is described in Japanese Patent Application Laid-Open No. 47-26913.
As another method, a method has been proposed in which a filament is produced from a mixture of two or more transparent polymer resins having different refractive indexes. After the special solvent treatment, a part of the resin mixture is dissolved to obtain an optical transmission column. This technique is disclosed in Japanese Patent Application Laid-Open No. 47-28059. In addition, in the method disclosed in Japanese Patent Application Laid-Open No. 54-30301, two monomers having different refractive indices are used to have a continuous refractive index distribution from the surface to the center of the column. It teaches a polymerization method for forming a polymeric material. In still another method, a method is disclosed in which the monomer is diffused into the surface layer of the block copolymer such that the content of the monomer in the block copolymer is continuously distributed from the surface layer of the block copolymer to the center. Was. Next, a polymerization reaction is carried out to produce an optical transmission column having a continuous refractive index distribution. These techniques are described in Japanese
-5857, 56-37521 and 57-29682. It should be noted that all of the disclosed methods and techniques are performed in a discontinuous batch operation.

[0004] In order to overcome the deficiencies of the discontinuous production process, the continuous production method is disclosed in Japanese Patent Application Laid-Open Nos. 1-189621 and 1-25.
3704, 2-16505 and 2-233104. In this technique, a polymeric material and a monomer are mixed in a mixing tank and heated until the polymeric material is dissolved and uniformly mixed in the monomer. Thereafter, the monofilament is extruded from the mold and sent to a gas evaporator. Gas is sent to the evaporator so that the monomer evaporates from the monofilament surface. In this way, a monofilament in which the concentration of the monomer is continuously distributed is formed. After the curing treatment, a polymer material monofilament having a continuous refractive index distribution from the surface layer toward the center is obtained.

The above method has several disadvantages:
For example, the time required for diffusion is long (thus, the production time is long and the production speed is reduced), it is difficult to select the optimal production conditions, and there is a lack of reproducibility. These issues must be resolved before the method can be applied to the production floor.

[0006]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an optical transmission column having a refractive index distribution that is continuous from its surface layer (or surface, hereinafter referred to as a surface layer) toward the center of the column. To provide a method of manufacturing from

Another object of the present invention is to provide a method for manufacturing a column for optical transmission having a continuous refractive index distribution in a column from a polymer material, that is, a process which can be actually produced.

It is a further object of the present invention to provide a method for manufacturing an optical transmission column having a continuous refractive index distribution from its surface layer toward the center of the column from a polymer material at a high production rate. is there.

Another object of the present invention is to manufacture an optical transmission column having a continuous refractive index distribution from its surface layer toward the center of the column from a polymer material with a high level of reproducibility in a continuous process. The purpose is to provide a way to gain.

[0010]

According to the present invention, there is provided a method for producing, from a polymer material, an optical transmission column having a refractive index distribution that is continuous from the surface layer toward the center of the column in a continuous production process.

In a preferred embodiment, the composite monofilament is extruded from a polymer solution containing two monomers having different refractive indices, and the monomers diffuse into each other before the composite monofilament is cured. A continuous manufacturing method is provided by diffusing the diffusion regions together. Then, after the curing step, a part of the composite monofilament is removed in a layer form from the surface.

In an alternative embodiment, the composite monofilament is extruded from a solution of a polymeric material containing two monomers having different refractive indices, and the monomers are diffused into each other in the composite monofilament. , A continuous manufacturing process of the light / image transmission column is performed. A portion of the composite monofilament is then removed from the surface in a layer before the composite monofilament is cured.

[0013]

According to the preferred or alternative embodiment described above,
An optical / image transmitting polymer material column having a refractive index distribution in the column and capable of transmitting an image can be produced. This type of polymer column for light / image transmission is composed of an optical lens,
It can be used as an optical fiber or an optical integrated circuit.

According to the present invention, the above-mentioned light / image transmission column having high optical transparency can be produced in a continuous process.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention discloses a method for producing a light / image transmission column having a continuous refractive index distribution from a surface layer toward the center of a column from a polymer material in a continuous production process.

In the present invention, a first mixture of one polymer material and one monomer which is a solvent of the polymer material or a single mixture of one polymer material and a solvent of the polymer material is used. A first mixture of two or more monomers comprising a body;
One polymeric material and a second mixture of one monomer different from the monomers contained in the first mixture are extruded through a concentric mold into a double-layer composite monofilament. . The separate monomers are diffused in the diffusion region of the composite monofilament until the two monomers diffuse into one another. The composite monofilament is then cured and a portion of the composite monofilament is removed from the surface in a layer.

In the second embodiment, before the composite monofilament is cured, a part of the composite monofilament is first removed from the surface in a layer. In either embodiment, a polymer column for light / image transmission having a continuous refractive index distribution from the surface layer toward the center of the column is generated for the purpose of image transmission.

The polymer material used in the present invention may be polymethyl methacrylate, or methyl methacrylate and other monomers such as ethyl methacrylate and n-methacrylate.
Propyl, isopropyl methacrylate, t-methacrylate
-Butyl, cyclohexyl methacrylate, fluoroalkyl methacrylate, methyl 2-hydroxymethacrylate, ethyl 2-phenoxymethacrylate, glyceryl methacrylate, benzyl methacrylate, phenyl methacrylate. The polymeric material may be a copolymer of methyl methacrylate and an acrylate such as methyl acrylate, ethyl acrylate, propyl acrylate or fluoroalkyl acrylate. Further, the polymer material may be a copolymer of methyl methacrylate and methacrylic acid such as acrylic acid.

The first monomer, monomer B, and the second monomer, monomer C, used in the present invention are methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, methacrylic acid. Isopropyl acrylate, t-butyl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, fluoroalkyl methacrylate, 2-hydroxymethyl methacrylate, 2-phenoxyethyl methacrylate, gallyl methacrylate, methyl acrylate, methyl acrylate, acrylic Acrylic acid type monomers such as ethyl acrylate, propyl acrylate or fluoroalkyl acrylate may be included.

In order to carry out the present invention, a first mixture of a polymer material of methyl methacrylate and a monomer B and a second mixture of a polymer material of methyl methacrylate and a monomer C are formed. Is done. During production, heat activated curing agent or UV
An activated hardener is added to the mixture. The content of monomer B or monomer C in the mixture is about 10% of the total mixture.
To about 80 weight percent, preferably between about 30 to about 80 weight percent, and more preferably about 4 to about 80 weight percent.
It ranges from 0 to about 70 weight percent. Thermally activated curing agents commonly used in the present invention are peroxide type curing agents, while typical UV activated curing agents are benzophenone and 1-hydroxycyclohexyl phenyl ketone.

In the present invention, the polymer material / monomer B
And when the two mixtures of the polymer material / monomer C is made, the viscosity of the resulting mixture is in the range of between about 10 ² to 10 ⁵ poise. When lower than 10 ² poise viscosity,
The composite monofilament is frequently cut, making it difficult to extrude the aforementioned composite monofilament. Viscosity is 10
Above ⁵ poise, extrusion of the composite monofilament is practically difficult.

In the next processing step, the two different mixtures are extruded through concentric molds to form a composite monofilament having inner and outer layers of different materials. The extrusion process is performed according to the following standard industry practice. After the extrusion process, the monomer B and the monomer C mutually diffuse through a diffusion region which is a boundary between the inner and outer layers. The extruded composite monofilament is then cured by either heat activation or UV activation means, followed by removal of a portion of the composite monofilament from the surface in a layer to complete the process.

In order to obtain excellent image transmission, the distribution of the refractive index must follow a quadratic parabolic curve. After the completion of the diffusion treatment of the monomers B and C, the layered portion having a certain thickness from the surface of the composite monofilament (hereinafter referred to as the outermost layer) no longer has a refractive index distribution according to such a secondary parabolic curve. It became clear that it would not be shown. Therefore, in order to maintain the image transmission property of the composite monofilament, it is necessary to remove the outermost layer of the composite monofilament. A suitable thickness of the outermost layer to be removed is between about 10% and about 60% of the diameter of the composite monofilament.
Preferably between about 20% and about 50%, and more preferably between about 25% and about 40%.

In an alternative embodiment, a portion of the composite monofilament is first layered off the surface (with the outermost layer) before it is cured. Therefore, a high-quality light / image transmission column having a continuous refractive index distribution and capable of transmitting an image can be obtained.

In the composite monofilament made according to the present invention, the volume ratio of the inner and outer layers of the composite monofilament extruded through the concentric mold is about 1: 1 to about 1: 100, and the above-mentioned inner and outer layers are preferably used. The volume ratio is between about 1: 1 and about 1:10, and the more preferred volume ratio of the inner and outer layers is between about 1: 1 and about 1: 5.

As an additional processing step, if desired during the diffusion of the two monomers of the composite monofilament, the diffusion zone may be heated in a conventional manner to further promote diffusion. However, such heating should not cause any further polymerization of the composite monofilament.

By subjecting the above-mentioned composite monofilament to UV irradiation or heat treatment, the curing treatment of the composite monofilament may be accelerated, but is not always necessary. Suitable irradiation sources are, for example, carbon arc lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, low-pressure mercury lamps, electrodeless lamps, xenon lamps or laser sources used at a wavelength between 150 nm and 600 nm.

The apparatus used in the present invention will be described with reference to FIG. 1 (FIG. 1). The material supply tank 10 contains a solution of one polymer material and at least one monomer B, and the material supply tank 12 contains 1 solution.
A solution of one polymeric material and at least one monomer C is charged. Heating devices 14 and 16 are used to facilitate dissolution of the polymeric material in monomers B and C. The solution is usually heated to a predetermined temperature above room temperature. Constant volume pumps 18 and 20 are used to pump the two mixtures at a predetermined flow rate into a concentric mold 22. The double-layer composite monofilament 24 is
From the orifice (not shown) of the
It is sent to 6. While traveling through the diffusion zone 26 for a time not less than 1 second, the monomer in the outer layer and the monomer in the inner layer diffuse with each other to exert the effect of the continuous refractive index distribution on the composite monofilament. Occurs. At the outlet end of the diffusion zone 26, a separating device 28 is provided, and
4. Separate the outermost layer. This separation device may be mechanical, optical or any other means. Thereafter, the composite monofilament 24 is sent to a curing zone 30 where it is cured. The composite monofilament 24 is then removed through a roller 32 by a take-off roll 34.

Other objects, features and advantages of the present invention will become apparent from a consideration of the accompanying drawings, which show a specification and an overview of the apparatus used in the method of the present invention.

EXAMPLE 1 The first mixture used for the inner layer (ie, the core) was 50 parts by weight of methyl methacrylate, 50 parts by weight of benzyl methacrylate monomer, 0.2 part by weight of 1-hydroxycyclohexyl phenyl ketone. , And 0.1 part by weight of hydroquinone. The total weight of the first mixture is approximately 100. The second mixture used for the outer layer (i.e., the cladding) was 50 parts by weight of methyl methacrylate, 50 parts by weight of methyl methacrylate monomer, 0.2 part by weight of 1-hydroxycyclohexyl phenyl ketone, and 0.1 part by weight of hydroquinone.
Consists of 1 part by weight. The total weight of the second mixture is approximately 1
00. The two mixtures are pumped simultaneously through concentric orifices.

After passing the composite monofilament 24 through a closed diffusion zone approximately 20 cm long using the apparatus shown in FIG. 1, the composite monofilament 24 is cured with four equally spaced 60 cm long hardened Through a curing zone 30 containing a high pressure mercury lamp. The resulting composite monofilament has a volume ratio of inner layer to outer layer of 1: 3. Thereafter, the outermost layer of the composite monofilament 24 is removed by the separating device 28.

After removal of the outermost layer, the composite monofilament
It has a diameter of 1 mm. The refractive index distribution was found to be 1.525 at the center of the composite monofilament and 1.503 at the outer layer of the composite monofilament. The refractive index data was measured using an Interphako interference microscope. Also, composite monofilament
It is also evident that there was a continuous decrease in the refractive index from the center of the composite monofilament to the periphery of the composite monofilament. There is no distortion in the image transmitted by the composite monofilament for light / image transmission.

EXAMPLE 2 The first mixture used for the inner layer of the composite monofilament was composed of 50 parts by weight of polymethyl methacrylate, 50 parts by weight of a monomer of benzyl methacrylate, 0.2 part by weight of 1-hydroxycyclohexyl phenyl ketone. , And 0.1 part by weight of hydroquinone. The total weight of the first mixture is approximately 100. The second mixture used for the outer layer was 50 parts by weight of a polymethyl methacrylate polymer material,
50 parts by weight of a monomer of 2,2,3,3-tetrafluoropropyl methacrylic acid, 0.2 part by weight of 1-hydroxycyclohexyl phenyl ketone, and 0.1 part of hydroquinone
It is a mixture of parts by weight. The total weight of the second mixture is approximately 100. The two mixtures are extruded simultaneously through concentric mold orifices to form a composite monofilament.

The composite monofilament is then passed through a closed diffusion zone of 40 cm length shown in FIG. The resulting composite monofilament has a volume ratio of inner layer to outer layer of 1: 3. The outermost layer of the composite monofilament is removed before the composite monofilament is cured. The composite monofilament is then passed through a curing zone equipped with four equally spaced 60 cm long curing high pressure mercury lamps with a 60 watt power for curing.

The obtained composite monofilament is 1 mm
Having a diameter of The refractive index measured at the center of the composite monofilament is 1.522, while that measured at the outermost layer of the composite monofilament is 1.480. It has been observed that the refractive index decreases continuously from the center of the composite monofilament to the outermost layer of the composite monofilament. The image transmitted by the composite monofilament is not distorted.

A second composite monofilament having a different value of the inner layer to outer layer volume ratio (before removal of the outermost layer) of 1: 2 was also obtained. The diameter of the obtained composite monofilament is kept at 1 mm. The refractive index measured at the center of the composite monofilament is 1.522, while that measured at the outermost layer of the composite monofilament is 1.483. The composite monofilament shows a continuous decrease in the refractive index value from the center of the composite monofilament to the outermost layer of the composite monofilament. No distortion was observed in the image transmitted by the composite monofilament.

A third composite monofilament having a 1: 1 volume ratio of inner layer to outer layer (before removal of the outermost layer) was also obtained. The diameter of the obtained composite monofilament is again kept at 1 mm. The refractive index was measured using an Interphako interference microscope and was determined to be 1.518 at the center of the composite monofilament and 1.491 at the outermost layer of the composite monofilament. The composite monofilament also demonstrates a continuous decrease in refractive index from the center of the composite monofilament to the outermost layer. The image transmitted by the composite monofilament is not distorted.

While the foregoing has been described to describe the invention, the terms used should be understood as being intended to be illustrative rather than restrictive.

Further, while this invention has been described in terms of a preferred embodiment and its alternatives, it is contemplated that those skilled in the art will readily apply these teachings to other possible variations of the invention. .

The embodiments of the invention in which an exclusive property or patent is claimed are limited as set forth in the following claims.

[0041]

In a preferred embodiment, the composite monofilament is extruded from a polymer solution containing two monomers having different refractive indices, and the monomers are exchanged before the composite monofilament is cured. A continuous manufacturing method is provided by diffusing in a diffusion region so as to diffuse into each other. Then, after the curing step, a part of the composite monofilament is removed in a layer form from the surface.

In an alternative embodiment, the composite monofilament is extruded from a solution of a polymeric material containing two monomers having different refractive indices, and the monomers are diffused into each other in the composite monofilament. , A continuous manufacturing process of the light / image transmission column is performed. A portion of the composite monofilament is then removed from the surface in a layer before the composite monofilament is cured.

According to the preferred or alternative embodiment described above, the light / light having a refractive index distribution in the column and capable of transmitting an image.
A polymer material column for image transmission can be produced.
This kind of polymer column for light / image transmission can be used as an optical lens, an optical fiber, or an optical integrated circuit.

According to the present invention, the above-described light / image transmission column having high optical transparency can be produced in a continuous process.

Further, according to the present invention, there is provided a method of manufacturing an optical transmission column having a continuous refractive index distribution from a surface layer toward a column center from a polymer material in a continuous production process.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of an apparatus for manufacturing a composite monofilament for light / image transmission.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Material supply tank 12 Material supply tank 14 Heating device 16 Heating device 18 Metering pump 20 Metering pump 22 Concentric mold 24 Composite monofilament 26 Closed diffusion zone 28 Separation device 30 Curing zone 32 Roller 34 Roll

Continuation of the front page (72) Inventor Li Shigematsu 2nd floor 321 Guanghua Road, Hsinchu City, Taiwan (56) References JP-A-2-16504 (JP, A) JP-A-2-136804 (JP, A) JP-A 4-267205 (JP, A) JP-A-2-16505 (JP, A) JP-A-2-25804 (JP, A) JP-A-6-174944 (JP, A) (58) Fields investigated (Int. G02B ⁶ /00-6/44 B29C 47/26 B29D 11/00

Claims (13)

(57) [Claims] 1. A first mixture of a first polymer material and at least one first monomer that is a solvent for the first polymer material, and a second polymer material and a second mixture of the second polymer material and the second polymer material.
At least one second solvent that is a solvent for the polymeric material of
Preparing a second mixture with the at least one second monomer, wherein the at least one second monomer is different from the at least one first monomer. The first and second mixtures are concentric with orifices so that a composite monofilament having an inner layer and an outer layer formed by the first and second mixtures and having an interface therebetween is obtained. Flowing through a mold, and then passing the composite monofilament through a diffusing device for a time sufficient to allow a sufficient amount of the first and second monomers to diffuse across the interface to the outer and inner layers, respectively. After a part of the composite monofilament is removed in a layer form from the surface by passing the composite monofilament through the separation device, the irradiation energy of the composite monofilament is increased. Thus, the composite monofilament is made of a polymer material having a continuous refractive index distribution from the center of the composite monofilament to the outermost layer of the composite monofilament, which is useful for light / image transmission, by passing the composite monofilament through a curing jig so as to be cured. Of composite monofilaments. 2. The method according to claim 1, wherein the first polymer material and the second polymer material are polymethyl methacrylate, methyl methacrylate and ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, t-methacrylate. Butyl, cyclohexyl methacrylate, fluoroalkyl methacrylate, 2-hydroxymethyl methacrylate, 2-
Copolymer of a monomer selected from the group consisting of ethyl phenoxy methacrylate, glyceryl methacrylate, benzyl methacrylate, phenyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate, fluoroalkyl acrylate and acrylic acid The method of claim 1, wherein the method is selected from the group consisting of: 3. The at least one first monomer and the at least one second monomer are methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, methacrylic acid. t-butyl, cyclohexyl methacrylate, phenyl methacrylate, benzyl methacrylate, fluoroalkyl methacrylate, 2-hydroxymethyl methacrylate, 2-phenoxyethyl methacrylate, gallyl methacrylate, methyl acrylate, ethyl acrylate, propyl acrylate 2. The process according to claim 1, wherein the process is selected from the group consisting of: and fluoroalkyl acrylates. 4. The method of claim 1 wherein at least one of said first mixture and said second mixture is heated to a predetermined temperature to facilitate formation of said mixture. 5. The method of claim 1 wherein the formed composite monofilament has a diameter between about 0.1 mm and about 5 mm. 6. The method according to claim 1, wherein at least one of the first mixture and the second mixture further comprises a catalyst. 7. The volume ratio between the inner layer and the outer layer is about 1: 1.
The method of claim 1 wherein the ratio is between 1 and about 1: 100. 8. The method of claim 1, wherein the volume ratio of the inner layer to the outer layer is preferably between about 1: 1 and about 1:10. 9. The method of claim 1, wherein said separation device is selected from the group consisting of mechanical means, optical means and hydraulic means. 10. The method of claim 1, wherein said separating step of removing a portion of the composite monofilament from the surface in a layered manner is performed prior to a curing step. 11. The layered portion of the composite monofilament, wherein a portion of the composite monofilament is removed from the surface in a layer is between about 10% and about 60% of the diameter of the composite monofilament. Item 1. The method according to Item 1. 12. The laminar portion from which a portion of the composite monofilament is removed from the surface in a layer is preferably between about 20% and about 50% of the diameter of the composite monofilament. The method according to claim 1, wherein 13. The layered portion of the composite monofilament from which a portion of the composite monofilament is removed in a layered manner is more preferably between about 25% and about 40% of the diameter of the composite monofilament. The method according to claim 1, characterized in that: