JP3334457B2 - Light guide for light guide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a thermoplastic norvol.
A light guide light guide consisting of nen-based resin fiber, deterioration by heat of the light source is related to very small durable light guide for the light guide.

[0002]

2. Description of the Related Art An optical fiber having a core portion and a clad portion made of a transparent resin is used as various light guides because it is lightweight, has excellent flexibility and flexibility, and has excellent workability. Such a light guide usually guides the light of a light source such as a halogen lamp to a remote place. However, since the temperature of the light source is often as high as 100 ° C. or more, the light source side end face of the optical fiber is located at the light source side. There is a problem in that heat causes reaction with oxygen in the air to cause deterioration such as coloring, thereby deteriorating the performance as a light guide.

[0003]

[0008] The present invention has been made against the background of the problems of the prior art, deterioration by heat of the light source is suppressed as much as possible, a thermoplastic norbornene Durable
An object of the present invention is to provide a light guide for a light guide made of a resin- based optical fiber.

[0004]

According to the present invention, there is provided an optical fiber having a core material made of a thermoplastic norbornene-based resin (hereinafter also referred to as "resin") having an end face on the light source side having a thickness of 0.5 to 2 mm.
Sealed with a window material made of glass or quartz.
The periphery of the material and the vicinity of the end face of the optical fiber are held by the window material holder.
The window material holder and the optical fiber are used as a sealant.
The light guide for light guide , which is more tightly fixed, is also referred to as “light guide”. The light guide of the present invention is such that the end face of the optical fiber made of resin on the light source side is not directly in contact with the air end face because the fiber end face is hermetically covered with a window material made of glass or quartz. It is possible to prevent resin deterioration of the fiber end face. The window material used for the light guide of the present invention is made of glass or quartz, and is held by the window material holder . Here, the shape of the window material may be a flat plate or a lens. The thickness of the window material, or the maximum thickness when the window material is in the form of a lens is not particularly limited, but is in the range of 0.5 to 2 mm, particularly 0.7 to 1.1 mm in that the transparency of glass or quartz is not impaired. Is preferred. The above-mentioned window material holder is adapted to the outer diameter and the shape of the optical fiber made of the resin used in the present invention. As shown in FIG. 1, the optical fiber made of the resin and the window material holder is hermetically sealed with a sealant. ing. Here, as the sealing agent, an epoxy resin, a polyvinyl alcohol resin, an ethylene-polyvinyl alcohol copolymer, a polydiethylene glycol bisallyl carbonate resin generally known by a trade name of “CR-39”, or the like can be used. The window material holder may be made of metal or resin, but preferably has a heat deformation temperature of 100 ° C. or more, preferably 120 ° C. or more.

In the light guide of the present invention, the end face of the fiber and the window member made of glass or quartz may be in direct contact with each other or may be provided with a gap. Also,
It may be bonded via a transparent resin such as an epoxy resin. In the optical fiber made of the resin used in the present invention, the light source side end face that is hermetically covered with the window material may or may not be subjected to an end face treatment so that the face becomes smooth. When the fiber end face is processed, a known end face processing method such as a polishing method, a cold cut method, a hot knife method, and a hot plate method can be used. The optical fiber made of the resin used for the light guide of the present invention is a thermoplastic norbornene-based resin.
Core material of a transparent resin consisting of polymethyl methacrylate, polymethyl pentene, ethylene-vinyl acetate copolymer, vinyl acetate-vinyl chloride copolymer, tetrafluoroethylene polymer, tetrafluoroethylene-hexafluoropropylene copolymer Copolymer, chlorotrifluoroethylene polymer, chlorotrifluoroethylene-ethylene copolymer, vinylidene fluoride-tetrafluoroethylene copolymer, trifluoroethylene-vinylidene fluorite copolymer, fluorinated ester of (meth) acrylic acid Polymers, trifluoroethyl methacrylate, hexafluoro-2-propyl polymethacrylate, perfluoro-t-butyl methacrylate, selected from resins such as fluoropolymers such as polyfluoroisopropyl methacrylate, It is made of a cladding material consisting of a lower refractive index than A material resin. Used as core material
Thermoplastic norbornene resin has a heat distortion temperature of 100
° C or higher, and has heat resistance to the heat of the light source. Departure
In particular, the core material may be thermoplastic norbornene
Long-lasting without deformation due to heat of the light source
High light guide performance can be maintained over a period of time. The thermoplastic norbornene-based resin used in the light guide of the present invention has a norbornane skeleton in its repeating unit. For example, the thermoplastic resin contains a norbornane skeleton represented by the general formulas (I) to (IV).

[0006]

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[0007]

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[0008]

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[0009]

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(In the formula, A, B, C and D each represent a hydrogen atom or a monovalent organic group.) The thermoplastic resin having a norbornane skeleton used in the present invention is required to have a sufficient strength. Has a weight average molecular weight of 5,000 to 100.
10,000, preferably 8,000 to 200,000. Examples of the thermoplastic resin having a norbornane skeleton that can be used in the present invention include, for example, JP-A-60-168708.
JP, JP-A-62-252406, JP-A-62-252406
-252407, JP-A-2-133413, JP-A-63-145324, JP-A-63-2
Examples of the resin include resins described in JP-A-64626, JP-A-1-240517, and JP-B-57-8815. Specific examples of the thermoplastic resin include metathesis polymerization of at least one tetracyclododecene derivative represented by the following general formula (V) or an unsaturated cyclic compound copolymerizable with the tetracyclododecene. A hydrogenated polymer obtained by hydrogenating the obtained polymer can be exemplified.

[0011]

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(Wherein A to D are the same as above.) In the tetracyclododecene derivative represented by the above general formula (V), A, B, C and D each include a polar group.
It is preferable from the viewpoint of heat resistance and adhesion to a sealant. further,
The polar group - (CH _{2) n} COOR (where, R represents a hydrocarbon group having 1 to 20 carbon atoms, n represents an integer of 0) water to be a group represented by the resulting The addition polymer is preferable because it has a high glass transition temperature.
In particular, the - (CH ₂₎ a polar substituent represented by _n COOR is of general formula (V) of tetracyclododecene derivatives 1
It is preferable that one is contained per molecule. In the above general formula, R is a hydrocarbon group having 1 to 20 carbon atoms, but it is preferable in terms of decreasing the hygroscopicity of the obtained hydrogenated polymer as the number of carbon atoms increases, but the glass of the obtained hydrogenated polymer is preferred. From the viewpoint of a balance with the transition temperature, a chain alkyl group having 1 to 4 carbon atoms or a (poly) cyclic alkyl group having 5 or more carbon atoms is preferable, and a methyl group, an ethyl group,
Preferably, it is a cyclohexyl group. Further, the tetracyclododecene derivative of the general formula (V) in which a hydrocarbon group having 1 to 10 carbon atoms is simultaneously bonded as a substituent to the carbon atom to which the carboxylic acid ester group is bonded, reduces the hygroscopicity. preferable. In particular, the tetracyclododecene derivative of the general formula (V) in which the substituent is a methyl group or an ethyl group is preferable in that the synthesis is easy. Specifically, 8-methyl-8-methoxycarbonyltetracyclo [4.4.0.1 ^2,5 1 ^7,10 ] dodec-8-ene is preferred. These tetracyclododecene derivatives or mixtures of unsaturated cyclic compounds copolymerizable therewith are described, for example, in JP-A-4-77520, page 4, upper right column, line 12 to page 6, lower right column, line 6 The thermoplastic resin used in the present invention can be subjected to metathesis polymerization and hydrogenation by the method described. The hydrogenated polymer preferably has a softening temperature of 90 ° C. or higher and a glass transition temperature of 100 ° C. or higher from the viewpoint of heat resistance.

The hydrogenation rate of the hydrogenated polymer is 60 M
The value measured by Hz and ¹ H-NMR is 50% or more, preferably 90% or more, and more preferably 98% or more.
The higher the hydrogenation rate, the better the stability to heat and light. The hydrogenated polymer used as the thermoplastic resin having a norbornane skeleton in the present invention has a gel content of 5 in the hydrogenated polymer in order to prevent the occurrence of defects such as skin roughness on the surface of the molded product. % By weight or less, more preferably 1% by weight. ASTM of the thermoplastic norbornene resin thus obtained
The total light transmittance measured by D-1003 is 85% or more, preferably 90% or more, and more preferably 92% or more.

In addition, the thermoplastic norbornene resin used in the present invention may contain, if necessary, a known antioxidant such as 2,6-di-t-butyl-4-methylphenol and 2,2'-dioxy. -3,3'-di-t-butyl-5,5'-dimethylphenylmethane, tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane, 1,1 , 3-Tris (2-methyl-4-hydroxy-5-t-butylphenyl) butane, 1,3,5-trimethyl-2,4,6
-Tris (3,5-di-t-butyl-4-hydroxybenzyl-benzene, stearyl-β- (3,5-di-t
-Butyl-4-hydroxyphenyl) propionate,
2,2′-dioxy-3,3′-di-t-butyl-5,5
5'-diethylphenylmethane, 3,9-bis [1,1
-Dimethyl-2- [β- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy] ethyl], 2,4,8,10-tetraoxospiro [5,5]
Undecane, tris (2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis (2,4-di-t-butylphenyl) phosphite, cyclic neopentanetetraylbis (2 6
-Di-t-butyl-4-methylphenyl) phosphite, 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite can be added. The addition amount of these antioxidants is usually 0.1 to 3 parts by weight, preferably 0.2 to 2 parts by weight based on 100 parts by weight of the thermoplastic norbornene resin. If the amount of the antioxidant is too small, the effect of improving the durability is insufficient. If the amount is too large, problems such as bleeding from the molding surface and reduction in transparency are not preferred.

In the thermoplastic norbornene resin used in the present invention, in addition to the above-mentioned antioxidants, if necessary, an ultraviolet absorber, for example, pt-butylphenyl salicylate, 2,2 '. -Dihydroxy-4-methoxybenzophenone, 2,4-dihydroxybenzophenone, 2-
Hydroxy-4-methoxybenzophenone, 2- (2 ′
-Dihydroxy-4'-m-octoxyphenyl) benzotriazole; a stabilizer, an antistatic agent, a dye, a pigment, a flame retardant, an elastomer for improving impact resistance, and the like can be added. Further, an additive such as a lubricant may be added for the purpose of improving workability. As a method for obtaining an optical fiber used for the light guide of the present invention, a known method can be used.For example, the above-mentioned transparent resin to be the core material is heated and melted, and the clad material is formed by forming the core material into a fiber while pulling it. Examples of the method include attaching them. In the production of the optical fiber, a thermoplastic norbornene-based resin is used as a core material, and the resin temperature is preferably set to 210 ° C. to 390 ° C. Here, the above-described materials can be used as the cladding material. In the present invention, the diameter of the core material is 0.1.
The diameter is 2 to 50 mm, preferably 0.5 to 20 mm, and the diameter including the thickness of the clad material is 0.1 to 100 μm, preferably 0.5 to 60 μm.

In the optical fiber used in the light guide of the present invention, the outside of the cladding material is further provided with a thermoplastic resin such as polyvinyl chloride, polyethylene, polyvinyl alcohol, ethylene-vinyl alcohol copolymer, fluorine rubber, ethylene-propylene (-). Diene) copolymer rubber, styrene
It may be coated with a rubbery polymer such as butadiene copolymer rubber. Among them, those coated with an ethylene-polyvinyl alcohol copolymer are particularly excellent in durability because deterioration of the optical fiber due to contact with oxygen in the outside air at high temperature is suppressed. As shown in FIG.
The end face of the optical fiber of the present invention may be sealed with a window material, and the end face of an optical fiber bundle formed by bundling a plurality of optical fibers as shown in FIG. 2 is sealed with a single window material. It may be. Further, in the light guide of the present invention, the end face of the optical fiber opposite to the end face on the light source side may have the same hermetic coating as that on the light source side, or in particular, the end face is not coated. There may be. The light guide of the present invention is used for medical and dental applications, inspection / measurement applications, automobile / home appliance applications, optical device applications, display /
It can be used for a wide range of applications such as signs and displays.

[0017]

Hereinafter, embodiments of the present invention will be described.
The present invention is not limited by this. In addition,
In Examples, parts and% are based on weight unless otherwise specified. Reference Example 1 8-methyl-8-methoxycarbonyltetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodeca-3-ene 10
2. A toluene solution of 0 g, 60 g of 1,2-dimethoxyethane, 240 g of cyclohexane, 9 g of 1-hexene, and 0.96 mol / l of diethylaluminum chloride.
4 ml was added to an autoclave having a volume of 1 liter. On the other hand, in another flask, 0.1 kg of tungsten hexachloride was added.
20 ml of a 05 mol / l 1,2-dimethoxyethane solution
And 10 ml of a 0.1 mol / l 1,2-dimethoxyethane solution of paraaldehyde. This mixed solution 4.9
ml was added to the mixture in the autoclave. After sealing, the mixture was heated to 80 ° C. and stirred for 4 hours.
To the obtained polymer solution, a mixed solvent of 2/8 (weight ratio) of 1,2-dimethoxyethane and cyclohexane was added to make the polymer / solvent 1/10 (weight ratio), and then 20 g of triethanolamine was added. Was added and stirred for 10 minutes. 500 g of methanol was added to the polymerization solution, and the mixture was stirred for 30 minutes and allowed to stand. The upper layer separated into two layers was removed, methanol was added again, and the mixture was stirred and allowed to stand, and then the upper layer was removed. The same operation was further performed twice, and the obtained lower layer was cyclohexane, 1,
Dilute appropriately with 2-dimethoxyethane and polymer concentration is 10
% Cyclohexane-1,2-dimethoxyethane solution. 20 g of palladium / silica magnesia [manufactured by Nikki Chemical Co., Ltd., palladium amount = 5%] was added to the solution, and the mixture was reacted at 165 ° C. in an autoclave under a hydrogen pressure of 40 kg / cm ² for 4 hours. Was removed by filtration to obtain a hydrogenated polymer solution. Further, pentaerythrityl-, an antioxidant, was added to this hydrogenated polymer solution.
0.1% of tetrakis [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] was added to the hydrogenated polymer, and the solvent was removed at 380 ° C under reduced pressure. Next, the molten resin was pelletized by an extruder in an atmosphere under nitrogen, and the weight average molecular weight was 7.0 × 1.
0 ^4, hydrogenation ratio of 99.5%, a glass transition temperature of 168 ° C., to obtain a thermoplastic resin A having a refractive index of 1.51. Reference Example 2 6-ethylidene-2-tetracyclododecene was subjected to metathesis ring-opening polymerization in the same manner as in Reference Example 1, then hydrogenated and pelletized to obtain a weight average molecular weight of 5.5 × 10 ⁴ and a hydrogenation rate of 99.
A thermoplastic resin B having 5%, a glass transition temperature of 140 ° C. and a refractive index of 1.53 was obtained.

Example 1 Using the thermoplastic resin obtained in Reference Example 1 as a core material and polymethacryl perfluoro-t-butyl having a refractive index of 1.36 as a cladding material, the outer diameter of the core was 1 mm, and the cladding portion was used. An optical fiber having a thickness of 50 μm was manufactured by a known method. On the other hand, diethylene glycol is placed on the inner wall surface of the window material holder with a holder made by holding a disc-shaped glass plate having a diameter of 2 mm and a thickness of 1.1 mm with an aluminum window material holder having an inner diameter of 2 mm, an outer diameter of 2.5 mm and a cylinder length of 5 mm. Bisallyl carbonate ("CR-39", manufactured by Asahi Pen Chemical Co., Ltd.) 100 g
And a mixture of 3 g of diisopropyl carbonate. Insert the optical fiber into this holder until the end face of the optical fiber and the glass window material come into contact with each other, and then 5 hours at 45 ° C., 5 hours at 55 ° C., 3 hours at 65 ° C., 3 hours at 75 ° C., 85 The composition was heated and cured by holding at 3 ° C. for 3 hours and at 95 ° C. for 3 hours to obtain a light guide. The side surface of the light guide where the window material was mounted was placed so as to be in contact with the halogen lamp, and after the lamp was continuously lit for 100 hours, the YI value of the window material mounting side end surface of the optical fiber was measured in accordance with JIS K7103. Met.

Example 2 An optical fiber was formed in the same manner as in Example 1 except that the thermoplastic resin B obtained in Reference Example 2 was used, and a window material was attached to one end face to obtain a light guide. The YI value of this light guide was 1.0. Comparative Example 1 The optical fiber formed in Example 1 was placed directly in contact with a halogen lamp without attaching a window material to the end face, and then the lamp was continuously lit for 100 hours. When the YI value of the end face of the optical fiber after emitting light was measured, it was as large as 12.

[0020]

The light guide of the present invention is hermetically covered with a window material so that the light source side end face does not touch the outside air.
The end face is not colored and deteriorated by heat generated when the halogen lamp emits light, and maintains high light guide characteristics for a long time. Also, since the optical fiber is made of thermoplastic norbornene resin , heat resistance is low.
It is high and can be suitably used in applications requiring high heat resistance, such as in-vehicle applications.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing an example of a light guide of the present invention.

FIG. 2 is a schematic sectional view showing another example of the light guide of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Optical fiber 2 Window material 3 Window material holder 4 Sealant

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-7-234327 (JP, A) JP-A-4-365003 (JP, A) JP-A-61-59303 (JP, A) 81606 (JP, U) (58) Field surveyed (Int. Cl. ⁷ , DB name) G02B 6/00-6/10 G02B 6/16-6/26 G02B 6/30-6/44

Claims (1)

(57) [Claims] An optical fiber whose core material is made of a thermoplastic norbornene resin has a light source side end face having a thickness of 0.5 to 2 mm.
Sealed and covered with window material made of glass or quartz,
The periphery of the window material and the vicinity of the end face of the optical fiber are a window material holder.
In addition, the window material holder and the optical fiber are sealed
A light guide for a light guide, wherein the light guide is hermetically sealed and fixed .