JP2010107961A - Plastics optical fiber cord - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plastics optical fiber cord for house wiring and car interior wiring, which has excellent adhesiveness to a covering layer, while maintaining transmission loss, resistance to moist heat, flexing resistance etc. <P>SOLUTION: The plastics optical fiber cord has a plastics optical fiber 1 composed of a core and at least one cladding layer and at least one coating layer 2 disposed on the outer layer thereof, wherein the cladding of the outermost layer of the plastics optical fiber contains the following components and adhesive force between the coating layer and the plastics primary coated optical fiber at a length of 30 mm is 50 N or more. The components are: vinylidene fluoride of 52-72 mol%; tetrafluoroethylene of 26-46 mol%; and hexafluoropropylene of 2-8 mol%. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a plastic optical fiber cord that is used for indoor wiring, automobile wiring, and the like having excellent adhesion to a coating layer while maintaining heat resistance, moist heat resistance, bending resistance, and the like.

  Plastic optical fibers are superior to glass-based optical fibers in terms of processability, handleability, and manufacturing cost, and are widely used for short-distance optical signal transmission, lighting light guides, and the like. For the purpose of protecting plastic optical fibers, plastic optical fiber cords are known in which the outer periphery of the plastic optical fiber is covered with a coating layer using an extrusion molding machine. Photoelectric sensors, optical signal transmission, and recently in-car information communication It is used in fields such as applications.

  The plastic optical fiber is composed of two types of polymers, a core and a clad. For the core, a polymer having excellent transparency and good weather resistance is generally used, as represented by polymethyl methacrylate (hereinafter abbreviated as PMMA). On the other hand, the clad needs to have a lower refractive index than the core in order to confine light inside the core, and fluorine-containing polymers are widely used.

  For indoor wiring and in-car information communication applications, plastic optical fibers are often constructed in a narrow space in a hot and humid environment, and have heat resistance, moisture and heat resistance, bending resistance, bending loss resistance, etc. Required.

  Furthermore, plastic optical fiber cords are usually used with a connector attached to the end. However, when the coating layer is peeled off, it is easy to damage the plastic optical fiber wire. A mounting method for connecting and fixing parts is used. When the covering layer is connected and fixed to the connector component, it is necessary that the adhesive strength between the plastic optical fiber and the covering layer be high in order to maintain the connection strength between the connector and the plastic optical fiber cord.

  Therefore, it has been studied to polymer blend or copolymerize a clad material with the resin of the coating layer, or to use a special highly adhesive resin.

  By the way, for the purpose of improving the heat resistance, moist heat resistance, bending resistance, and bending loss resistance properties of plastic optical fibers, vinylidene fluoride (vinylidene fluoride), tetrafluoroethylene, and hexafluoropropylene, which have a low refractive index in the cladding, are used. Several techniques have been proposed for improving the bending properties using a terpolymer comprising

  For example, as shown in Patent Document 1, a terpolymer having a clad material in the range of 30 to 50% by weight of vinylidene fluoride component, 25 to 55% by weight of tetrafluoroethylene component, and 15 to 25% by weight of hexafluoropropylene component is used. A plastic optical fiber using is disclosed.

  Moreover, as shown in Patent Document 2, the clad material has a vinylidene fluoride component in the range of 45 to 57 mol%, a tetrafluoroethylene component in the range of 31 to 35 mol%, and a hexafluoropropylene component in the range of 12 to 20 mol%. There has been proposed a plastic optical fiber in which a protective layer made of a vinylidene fluoride resin is coated on the outside of a plastic optical fiber element using a terpolymer.

  In Patent Document 3, the refractive index of the first cladding is made of a resin higher than the refractive index of the second cladding, and the second cladding has a vinylidene fluoride component of 30 to 92 mol% and a tetrafluoroethylene component of 0 to 55 mol%. A plastic optical fiber made of a terpolymer in the range of 8 to 25 mol% of the hexafluoropropylene component is disclosed. Further, (meth) acrylic acid long chain fluoroalkyl ester / (meth) acrylic acid short chain fluoroalkyl ester / (meth) acrylic acid methyl copolymer is exemplified as an optimum material for the first cladding.

  On the other hand, in Patent Document 4, the core is a (co) polymer containing methyl methacrylate as a main component, the first cladding is a copolymer containing perfluoroalkyl methacrylate and methyl methacrylate, and the second cladding is a hexafluoropropylene component 10. A plastic optical fiber comprising a copolymer containing -25% by weight, a tetrafluoroethylene component of 35-70% by weight, and a vinylidene fluoride component of 15-45% by weight is disclosed.

  However, the plastic optical fiber disclosed in Patent Document 1 has a high numerical aperture and excellent transmission loss. On the other hand, since the clad material is flexible, there is a problem of sticking at the time of winding, and heat resistance and heat and humidity resistance are inferior. There was a problem.

  In addition, the plastic optical fiber disclosed in Patent Document 2 has a problem that heat resistance, wet heat resistance, adhesion to the coating layer, etc. are inferior, although the above-mentioned adhesiveness is improved by adopting a two-layer clad structure. was there.

  In addition, the second clad in the plastic optical fiber disclosed in Patent Documents 2, 3, 4, and 5 has a problem that although the heat resistance and the heat and humidity resistance are improved, the adhesion with the coating layer is insufficient. It was.

Japanese Patent No. 2857411 (Claims) Japanese Patent No. 3850961 (Claims) JP-A-11-101915 (Claims) JP 2002-156533 A (Claims) JP 2003-139773 A (Claims)

  Provided is a plastic optical fiber cord used for indoor wiring, automobile wiring, and the like, which maintains excellent balance with heat resistance, moist heat resistance, bending resistance and the like, and has excellent adhesion to a coating layer.

  In order to achieve the above object, the present invention has the following configuration.

That is, the present invention is a plastic optical fiber cord in which at least one coating layer is provided on an outer layer of a plastic optical fiber composed of a core and at least one clad, and the outermost clad of the plastic optical fiber has the following clad: This is a plastic optical fiber cord containing a component and having an adhesive force of 50 N or more between a coating layer and a plastic optical fiber in a length of 30 mm.
Vinylidene fluoride: 52-72 mol%
Tetrafluoroethylene: 26-46 mol%
Hexafluoropropylene: 2-8 mol%

  According to the present invention, a plastic optical fiber cord used for indoor wiring, automobile wiring, and the like, having excellent adhesion to the coating layer while maintaining a balance with heat resistance, moist heat resistance, bending resistance, and the like. Can provide.

FIG. 1 shows a schematic cross-sectional view of one embodiment of the plastic optical fiber cord of the present invention.

  The plastic optical fiber cord of the present invention is a plastic optical fiber cord in which at least one coating layer is provided on an outer layer of a plastic optical fiber comprising a core and at least one clad.

  FIG. 1 shows a schematic cross-sectional view of one embodiment of the plastic optical fiber cord of the present invention. In the figure, 1 is a plastic optical fiber, and 2 is a coating layer in contact with the plastic optical fiber.

  The core material of the plastic optical fiber cord of the present invention is preferably a (co) polymer containing methyl methacrylate (hereinafter abbreviated as MMA) as a main component, and PMMA or MMA is 70% by weight or more. Includes coalescence. The (co) polymer containing MMA as a main component is, for example, a copolymer of (meth) acrylic acid ester, (meth) acrylic acid, (substituted) styrene, (N-substituted) maleimide, or the like. Examples thereof include modified polymers such as reacted glutaric anhydride and glutarimide. Examples of (meth) acrylic acid esters include methyl acrylate, ethyl acrylate, ethyl methacrylate, butyl methacrylate, t-butyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, phenyl methacrylate, bornyl methacrylate, adamantyl methacrylate, and the like as substituted styrene. Examples of N-substituted maleimide include N-isopropylmaleimide, N-cyclohexylmaleimide, N-methylmaleimide, N-ethylmaleimide, and N-o-methylphenylmaleimide. A plurality of these copolymer components may be used, and a small amount of other components may be used. Further, a stabilizer such as an antioxidant may be contained in an amount that does not adversely affect transmission loss. Among these polymers, PMMA is most preferable from the viewpoint of productivity, transmission loss, environmental resistance and the like.

The clad material in the plastic optical fiber cord of the present invention is such that the outermost clad has the following components: vinylidene fluoride: 52 to 72 mol%
Tetrafluoroethylene: 26-46 mol%
Hexafluoropropylene: 2-8 mol%
contains.

  When the copolymerization component is outside this range, low refractive index and low crystallization (low transmission loss) cannot be achieved, the adhesion of the core to the MMA-based (co) polymer is inferior, Mechanical properties such as bendability are greatly reduced, low crystallization (colorless and transparent) cannot be achieved, mechanical properties such as bend resistance are greatly reduced, and there is stickiness and heat resistance. There are problems such as insufficient.

  The outermost clad is preferably made of an organic polymer having a refractive index smaller than that of the core, and the copolymer has a melt flow rate (hereinafter referred to as MFR) value of 5 to 30 g / 10 min. It is preferable.

  Moreover, it is preferable that the MFR value of the said copolymer exists in the range of 5-30 g / 10min (conditions: 230 degreeC, load 2.16kg, orifice diameter 2mm, length 8mm). If the MFR value is less than 5, the melt viscosity is too high and molding may be difficult, and transmission loss tends to deteriorate. If it exceeds 30, the molecular weight may be low and the mechanical properties and heat resistance may be poor.

  In the present invention, it is important that the adhesive force between the coating layer and the plastic optical fiber in the 30 mm length of the outer periphery of the plastic optical fiber is 50 N or more. The method for measuring the adhesion force between the coating layer and the plastic optical fiber in the length of 30 mm will be described later.

  When the adhesion force is less than 50 N, when the plastic optical fiber cord is pulled out from the connector, the plastic optical fiber strand and the coating layer are peeled off, and the end face of the plastic optical fiber is retracted, thereby reducing the reliability of optical coupling. Further, there is a concern that pistoning may occur even in environmental changes, and 50 N or more is necessary. Further preferable adhesion is 60 N or more. In the case of a plastic optical fiber having an outer diameter of 1000 μm, the adhesion is more preferably 60 to 100N. If the adhesive force is 100 N or more, the plastic optical fiber is more than the breaking strength of the plastic optical fiber.

  When the plastic optical fiber cord of the present invention has a core / clad two-layer core-sheath structure, the thickness of the clad layer is preferably 2 to 20 μm, particularly preferably 5 to 15 μm.

  In the plastic optical fiber cord of the present invention, preferably, the clad includes a first clad and a second clad.

The plastic optical fiber cord of the present invention has CH ₂ ═C (CH ₃ ) —COOCH ₂ (CF ₂ ) _n R as the first cladding.
(However, R represents a fluorine atom or a hydrogen atom, and n represents an integer of 1 to 4.)
From the viewpoint of transparency and heat resistance, it is preferable to use a copolymer containing 40 to 90 mol% of perfluoroalkyl methacrylate and 10 to 60 mol% of methyl methacrylate as a copolymerization component.

  Perfluoroalkyl methacrylates other than those represented by the above chemical formulas may cause the copolymer to become cloudy, yellow, or have extremely poor mechanical properties. If plastic optical fibers are used, the transmission loss, heat resistance, flex resistance, etc. are poor. It may be enough.

  The perfluoroalkyl methacrylate preferably used in the present invention is more preferably 2,2,2-trifluoroethyl methacrylate, 2,2,3,3-tetrafluoropropyl methacrylate, 2,2, There are 3,3,3-pentafluoropropyl methacrylate.

  Perfluoroalkyl methacrylates preferably used in the present invention are (meth) acrylic acid esters other than MMA, methacrylic acid having an alicyclic hydrocarbon in the ester, (meth) acrylic acid, (substituted) styrene, (N- Substitution) Maleimide or the like may be copolymerized within about 10% by weight.

In the plastic optical fiber cord of the present invention, preferably, the second cladding has the following component vinylidene fluoride: 52 to 72 mol%
Tetrafluoroethylene: 26-46 mol%
Hexafluoropropylene: 2-8 mol%
Have

  In the plastic optical fiber cord of the present invention, preferably, the refractive index of the first cladding is made of a resin lower than that of the core and higher than that of the second cladding. If the second clad has a lower refractive index than the first clad, it is preferable because the plastic optical fiber cord is bent or functions to reflect and collect light leaking from the irregular portion of the first clad.

  In the plastic optical fiber cord of the present invention, the theoretical numerical aperture of the plastic optical fiber using the first cladding is preferably NA = 0.45 to 0.52.

The theoretical numerical aperture is as follows: Numerical aperture = ((refractive index of the core) ² − (refractive index of the first cladding) ² ) ^1/2
It is represented by the refractive index difference between the core and the first cladding. By setting the numerical aperture to 0.45 to 0.52, it is possible to use the clad having a well-balanced physical property conventionally used in one layer as the first clad of the present invention.

  In the case where the plastic optical fiber cord of the present invention has a core / first cladding / second cladding three-layer core-sheath structure, the first and second cladding thicknesses are preferably 2 to 10 μm, respectively. Furthermore, it is preferable to make it thin so as not to cause a problem in characteristics, and it is particularly preferable that the total thickness of the first and second claddings is 5 to 15 μm.

  The plastic optical fiber cord of the present invention has at least one coating layer on the outer peripheral portion thereof.

  The coating layer is preferably made of a thermoplastic resin. For example, a polyamide resin such as a polyolefin resin, an olefin polymer containing an organosilane group, an ethylene-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene fluoride, nylon 12 or the like. Polyester resin, nylon elastomer, polyester elastomer, polyolefin elastomer, urethane resin, or fluororesin is used.

  From the viewpoints of oil resistance, wear resistance, heat resistance, and impact resistance, which are characteristics required for in-car communication applications, among these, the coating layer is made of polyamide 12 or polypropylene as the coating layer in contact with the outer periphery of the plastic optical fiber. It is preferable to use a resin having a main component. The resin mainly composed of polyamide 12 refers to a polyamide 12 homopolymer or a copolymer or polymer blend containing 50% by weight or more of polyamide 12, and includes a plasticizer, a flame retardant, an antioxidant, It may contain stabilizers such as aging agents, UV stabilizers, carbon black for coloring, pigments, dyes, etc., and a flexural modulus of 1.0 to 2.0 GPa, a tensile yield strength of 30 to 55 MPa, A general commercial product having a characteristic such as a deflection temperature under load (0.45 MPa) of 135 to 150 ° C. can be used, but it may have a characteristic in a range other than the above depending on the inclusion of the above additives or a polymer blend with another resin. Absent. Polypropylene-based resin refers to polypropylene, copolymers including cross-links with polyethylene, or mixtures thereof. In addition to flame retardants, antioxidants, anti-aging agents, UV stabilizers Or a pigment for coloring, tensile yield strength 20 to 35 MPa (ASTM D638), flexural modulus 1.1 to 1.7 GPa (ASTM D790), Rockwell hardness (R) General commercial products with characteristics such as 80 to 110 (JIS-K7202) and deflection temperature under load of 105 to 130 ° C. (JIS-K7207, 0.45 MPa) can be used, but the inclusion of the above additives and polymers with other resins Other blending characteristics may be used by blending.

In the plastic optical fiber cord of the present invention, more preferably, the first cladding is CH2 = C (CH3) -COOCH2 (CF2) nR.
(However, R represents a fluorine atom or a hydrogen atom, and n represents an integer of 1 to 4.)
A copolymer containing 40 to 90 mol% perfluoroalkyl methacrylate and 10 to 60 mol% methyl methacrylate as a copolymerization component, and a second clad,
An optical fiber made of a copolymer containing (1) vinylidene fluoride: 52 to 72 mol%, (2) tetrafluoroethylene: 26 to 46 mol%, and (3) hexafluoropropylene: 2 to 8 mol%. And a coating layer made of a thermoplastic resin increase the interaction between the optical fiber and the coating layer component, and the adhesion between the coating layer and the plastic optical fiber at a length of 30 mm at the outer periphery of the plastic optical fiber. Can be 50 N or more.

  The plastic optical fiber used in the present invention will be described.

  The plastic optical fiber of the present invention can be manufactured by a conventional method. For example, a composite spinning method in which a core material and a clad material are discharged from a composite die for concentric composites in a heated and melted state to form a core / clad two-layer core-sheath structure is preferably used. Further, for example, a composite spinning method for forming a core / first clad / second clad three-layer core-sheath structure is preferably used.

  Subsequently, for the purpose of improving mechanical properties, a stretching process of about 1.2 to 3 times is generally performed to obtain a plastic optical fiber.

  The outer diameter of the plastic optical fiber is usually about 0.1 to 3 mm, and an outer diameter of 0.7 to 1.5 mm is more preferable from the viewpoints of strength and wiring for wiring in an automobile. Further, when a protective layer is further provided on the outer layer, it can be produced by a known method, but a three-layer simultaneous spinning method is preferably used.

  Next, a method for manufacturing a plastic optical fiber cord will be described.

  The plastic optical fiber cord is obtained by forming a coating layer on the outer layer of the plastic optical fiber. The coating layer can be formed by a known method such as a melt extrusion method using a crosshead or a die.

  Hereinafter, the present invention will be described in more detail with reference to examples. Evaluation was performed by the following method.

Transmission loss:
Measurement was performed by a 30/2 m cutback method using halogen parallel light (wavelength 650 nm, incident NA = 0.25). It is a pass at 150 dB / km or less.

Pistoning:
A plastic optical fiber cord having a test length of 50 cm was placed in a high-temperature oven (PHH-200 manufactured by Tabai Espec Co., Ltd.) at 85 ° C. for 24 hours, and the length of the plastic optical fiber cord before and after the test was measured. Pistoning evaluation was performed by subtracting the length after the test from the length before the test in the plastic optical fiber cord. (-Represents a state in which the plastic optical fiber protrudes from the coating layer, and + represents a state in which the plastic optical fiber is retracted from the coating layer.) Within ± 0.5 mm is acceptable.

Heat-resistant:
A plastic optical fiber cord with a test length of 28m (1m at each end is outside the oven) is placed in a high-temperature oven (PHH-200 manufactured by Tabai Espec Co., Ltd.) at 85 ° C for 500 hours. Was used as an index (average value of n = 3, minus indicates a decrease in light amount). If the amount of change is within -1.0 dB, it is acceptable.

Moisture and heat resistance:
Evaluation was performed at a temperature of 85 ° C. and a humidity of 85% in the same manner as the heat resistance except that a constant temperature and humidity chamber (LH41-12A manufactured by Nagano Science Co., Ltd.) was used. If the amount of change is within -1.0 dB, it is acceptable.

Bending loss:
Using a 660 nm LED, the amount of light when it was wound 360 degrees around a metal round bar with a radius of 10 mm was measured, and the amount of change after winding was used as an index (average value of n = 3). If the amount of change is within -1.0 dB, it is acceptable.

Adhesion:
The coating layer of the plastic optical fiber cord having a test length of 90 mm was peeled off by 60 mm, and the optical fiber was exposed leaving only the coating layer by 30 mm. The fiber is passed through a metal plate with a hole 0.1 mm larger than the diameter of the optical fiber, and the fiber is pulled out at a tensile speed of 50 mm / min with a commercially available tensile tester. As shown. If the minimum value of n = 20 is 50N or more, it is a pass.

Refractive index:
An Abbe refractometer was used as a measuring device, and measurement was performed in an atmosphere at room temperature of 25 ° C.

Number of continuous bends:
Number of times until a cord is cut by applying a load of 500 g to one end of a plastic optical fiber cord and supporting it with a mandrel with a diameter of 30 mm, bending the other end of the fiber continuously at an angle of 90 ° around the support point Was measured (average value of n = 5). If you have more than 50,000 times, you will pass.

[Example 1]
A vinylidene fluoride (2F) / tetrafluoroethylene (4F) / hexafluoropropylene (6F) copolymer (refractive index: 1.371 MFR12) having the composition shown in Table 1 was supplied to the composite spinning machine as a clad material. Further, PMMA ((refractive index: 1.492)) produced by continuous soul polymerization is supplied as a core material to a composite spinning machine, and the core and cladding are melt-spun at 235 ° C., and the fiber diameter is 1000 μm (core A plastic optical fiber having a diameter of 980 μm and a cladding thickness of 10.0 μm was obtained.

  A polyamide resin (“Daiamide” L1640 manufactured by Daicel-Evonik Co., Ltd.) having a tensile yield strength of 40 MPa and a melting point of 178 ° C. was formed on the outer layer of the obtained plastic optical fiber by a melt extrusion molding method at a linear velocity of 50 m / min. . Further, a polyamide elastomer resin (“Grillamide” ELYXE3833 manufactured by Ems Chemie) having a tensile yield strength of 25 MPa and a melting point of 178 ° C. is formed on the outer layer by a melt extrusion molding method at a linear velocity of 50 m / min, and a plastic optical fiber cord It was.

  The plastic optical fiber cord thus obtained was evaluated by the above evaluation method. The results are shown in Table 2. As can be seen from Table 2, the adhesion, transmission loss, repeatability, heat resistance, heat and humidity resistance, and bending loss were all excellent.

[Examples 2 to 6 and Comparative Examples 1 to 5]
A plastic optical fiber cord was obtained in the same manner as in Example 1 except that the first clad / second clad were changed as shown in Table 1 (however, all the fiber diameters were unified to 1000 μm). These plastic optical fiber cords were used for the same evaluation as in Example 1, and the results are shown in Table 2.

  In Examples 2 to 6 of the present invention, the adhesion between the coating layer and the fiber was high, and the transmission loss, bending resistance, heat resistance, moist heat resistance, and bending resistance were all excellent.

  On the other hand, Comparative Examples 1 to 5 having different cladding composition ratios had poor adhesion, and transmission loss, bending resistance, and other physical property balances could not be achieved.

PMMA: Polymethyl methacrylate MMA: Methyl methacrylate 3FM: 2,2,2-trifluoroethyl methacrylate 4FM: 2,2,3,3-tetrafluoropropyl methacrylate 5FM: 2,2 , 3,3,3-pentafluoropropyl methacrylate 17FM: 1,1,2,2-tetrahydroperfluorodecyl methacrylate 2F: vinylidene fluoride 4F: tetrafluoroethylene 6F: hexafluoropropylene

Claims (7)

A plastic optical fiber cord in which at least one coating layer is provided on an outer layer of a plastic optical fiber composed of a core and at least one clad, wherein the outermost clad of the plastic optical fiber contains the following components: A plastic optical fiber cord in which the adhesion between the coating layer and the plastic optical fiber in a length of 30 mm is 50 N or more.
Vinylidene fluoride: 52-72 mol%
Tetrafluoroethylene: 26-46 mol%
Hexafluoropropylene: 2-8 mol% The clad is a plastic optical fiber cord composed of a first clad and a second clad, and the first clad is CH ₂ = C (CH ₃ ) -COOCH ₂ (CF ₂ ) _n R
(However, R represents a fluorine atom or a hydrogen atom, and n represents an integer of 1 to 4.)
The said 2nd clad has the following component which consists of a copolymer which contains 40-90 mol% of perfluoroalkylmethacrylate shown by these, and 10-60 mol% of methyl methacrylate as a copolymerization component. Plastic optical fiber cord.
Vinylidene fluoride: 52-72 mol%
Tetrafluoroethylene: 26-46 mol%
Hexafluoropropylene: 2-8 mol%   3. The plastic optical fiber cord according to claim 1, wherein the coating layer has a two-layer structure of a first coating layer and a second coating layer.   The plastic optical fiber cord according to claim 3, wherein the first coating layer is mainly composed of polyamide.   The plastic optical fiber cord according to claim 4, wherein the polyamide resin comprises polyamide 12 as a main component.   6. The plastic optical fiber cord according to claim 3, wherein the second coating layer is made of polyamide and / or thermoplastic elastomer.   The plastic optical fiber cord according to claim 6, wherein the thermoplastic elastomer has a flame retardancy equal to or higher than V2 in a flame retardancy test of UL94 standard.

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