JP2008197302A - Optical fiber cord - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical fiber cord having flame retardancy with a high self-extinguishing capability without containing halogen or metal hydroxide. <P>SOLUTION: The optical fiber cord has an external coating layer on the outer periphery of an optical fiber core. The external coating layer is composed of polymer alloy containing polyphenylene ether, wherein the polymer alloy has an oxygen index of ≥21 and a heating value of ≤28 kJ/g. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an optical fiber cord.

  In general, an optical fiber cord is used as an indoor transmission line in a device or a home.

  In the conventional optical fiber cord, an optical fiber made of quartz or the like is coated with an ultraviolet curable resin and a thermoplastic resin is coated. Further, a high tensile strength fiber vertically attached to the thermoplastic resin is coated. Through which the polymer is externally coated.

  Conventionally, polymers as external coating materials are (1) polyamide-based resin, fluorine-based resin, or polycarbonate, (2) PVC resin, (3) a mixed compound of an adhesive polymer such as EEA or EVA and a metal hydroxide ( For example, a material such as a mixed compound of flame retardant and Hytrel (trademark) has been used.

JP 2005-189349 A

  However, the optical fiber cord using the above-described material for the outer covering material has the following problems.

(1) Polyamide-based resin, fluorine-based resin, or polycarbonate Although excellent in flame retardancy, the calorific value at the time of combustion is large, and the self-extinguishing properties that disappear naturally when the flame is removed are poor.

(2) PVC resin Although excellent in flame retardancy, harmful gases such as halogen gas and dioxin gas are generated during combustion, so it is not suitable for use in equipment or indoors.

(3) Mixed compound of adhesive polymer such as EEA or EVA and magnesium hydroxide flame retardant Highly flame retardant and no harmful gas is generated, but bleed and deliquescence occur. That is, with the passage of time, the magnesium hydroxide is altered by nitrogen oxides, sulfurs and moisture in the air to produce a deliquescent compound. Due to the generation of the deliquescent compound, a bleed phenomenon in which the colorant contained in the coating material appears on the surface of the optical fiber cord easily occurs, and the bleed phenomenon deteriorates the surface appearance of the cord. In addition, the loss of the deliquescent compound from the coating material results in deterioration of properties such as mechanical properties and flame retardancy. In addition, deliquescent compounds flow out of the cord and drop, which adversely affects peripheral equipment.

(4) Mixed compound of flame retardant and Hytrel (trademark) Since the flame retardant is added, the flame retardant is high, but since the calorific value at the time of combustion is particularly large, the coating of (1) to (3) described above It is inferior in terms of self-extinguishing properties compared to the material. Further, if a large amount of a flame retardant is added in order to suppress the large amount of heat generation, the workability at the time of coating becomes very poor.

An object of the present invention is to provide a flame retardant optical fiber cord having a high self-extinguishing ability without containing a halogen substance or a metal hydroxide.

  The optical fiber cord according to claim 1 is an optical fiber cord provided with an outer coating layer on an outer periphery of an optical fiber core, and the outer coating layer is made of a polymer alloy containing polyphenylene ether, and the polymer alloy Has an oxygen index of 21 or more and a calorific value of 28 kJ / g or less.

  The optical fiber cord according to claim 2 is characterized in that, in the invention according to claim 1, the polymer alloy includes a styrene resin.

  The optical fiber cord according to claim 3 is the optical fiber cord according to claim 1, wherein the polymer alloy includes a styrene resin and a polyamide resin.

  An optical fiber cord according to a fourth aspect is characterized in that, in the invention according to the second aspect, the polymer alloy is one to which a phosphorus-based flame retardant is added.

  The optical fiber cord according to claim 5 is characterized in that, in the invention according to claim 3, the polymer alloy is added with a nitrogen-based flame retardant.

  The optical fiber cord according to claim 6 is the invention according to any one of claims 1 to 5, wherein high tensile strength fibers are vertically attached between the optical fiber core wire and the outer coating layer. It is characterized by.

  The optical fiber cord according to claim 7 is the invention according to any one of claims 1 to 6, wherein an outer diameter of the optical fiber core wire is in a range of 0.4 mm to 0.9 mm, and the outer coating layer The outer diameter is in the range of 1.0 mm to 3.0 mm.

  According to the present invention, flame retardancy having a high self-extinguishing ability can be obtained without containing a halogen substance or a metal hydroxide.

  DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The best mode for carrying out the present invention will be described below with reference to the drawings. However, this embodiment is exemplarily shown, and various modifications can be made without departing from the technical idea of the present invention. .

  The configuration of the optical fiber cord 8 according to the embodiment of the present invention will be described with reference to FIG. As shown in FIG. 1, for example, light coated with a thermoplastic resin 3 such as a polyamide resin on an optical fiber 5 in which the outside of an optical fiber 1 mainly composed of quartz glass is coated with an ultraviolet curable resin 2. A fiber core wire 6 is provided. Further, an aramid fiber such as Kevlar (trademark) is coated on the optical fiber core wire 6 as the high tensile strength fiber 4.

Next, a polymer alloy containing no halogen or metal hydroxide is coated on the outer periphery of the high tensile strength fiber 4 as an outer coating layer 7. This polymer alloy is obtained by mixing a plurality of polymers so as to have an oxygen index and a calorific value having flame retardancy with self-extinguishing ability (self-extinguishing).
In an environment where a large tension does not act on the optical fiber core 6, the polymer alloy may be directly coated on the optical fiber core without coating the high strength fiber 4.

The oxygen index is the proportion of oxygen in the atmosphere that allows the burned material to continue to burn when placed in a certain space. In the present invention, since the polymer alloy has self-extinguishing flame retardancy, in addition to a predetermined value of the calorific value described later, the oxygen index is preferably 21 or more, preferably 22 or more. If the oxygen index is 21 or more, even if the optical fiber cord 8 is burned, it will not burn continuously, and if it is 22 or more, it will not burn unless it is an extreme condition. is there.

The calorific value is the amount of heat released when the combusted material burns. In the present invention, since the polymer alloy has self-extinguishing flame retardancy, the calorific value is 28 kJ / g or less, preferably 25 kJ / g or less, in addition to the above-mentioned predetermined value of the oxygen index. Conventionally used polymers such as polyamide have a calorific value of 28.7 kJ / g, and polycarbonate has a calorific value of 29.4 kJ / g. Therefore, when a calorific value polymer alloy having a calorific value of 28 kJ / g or less, which is smaller than these calorific values, is used. This is because even if the cord 8 is burned, it will not burn continuously, and if it is 25 kJ / g or less, it will not burn unless it is an extreme condition.
The oxygen index and the calorific value may be satisfied only by mixing a plurality of polymers, or may be satisfied by adding a flame retardant. Furthermore, after satisfy | filling the value of the said oxygen index and the emitted-heat amount only by mixing of a some polymer, you may make it have a more self-extinguishing flame retardance by adding a flame retardant.

  Moreover, the polymer alloy which comprises the said outer coating layer 7 uses the some polymer which does not contain a halogen and a metal hydroxide. The plurality of polymers include, for example, any combination of polyphenylene ether and styrene resin, polyphenylene ether and polyamide resin, or polyphenylene ether, styrene resin, and polyamide resin.

  An optical fiber cord 8 is manufactured by covering the high tensile strength fiber 4 with the outer coating layer 7 made of such a polymer alloy.

  Here, the outer diameter of the optical fiber core 6 is in the range of 0.4 mm to 0.9 mm, and the outer diameter of the manufactured optical fiber cord 8 is in the range of 1.0 mm to 3.0 mm. Is preferred. When the outer diameter of the optical fiber core 6 and the outer diameter of the optical fiber cord 8 are outside the respective ranges, the shrinkage at low temperatures increases, the optical fiber strands bend slightly and the optical transmission loss increases, This is because a compressive stress is applied at a low temperature to compress the optical fiber 1 and increase transmission loss, thereby preventing them.

  Next, the mixture constituting the polymer alloy will be described. As described above, the polymer alloy is a mixture of polyphenylene ether and a styrene resin or a polyamide resin, and a flame retardant is attached if necessary. The chemical formula of polyphenylene ether is shown below.

  Examples of the styrene resin include a block polymer type styrene elastomer in addition to polystyrene alone. As block polymer type styrene elastomers, SBS (PS-polybutadiene-PS triblock copolymer), SIS (PS-polyisoprene-PS triblock copolymer), SEBS (PS-polyethylene / butylene-PS triblock). Copolymer), SEPS (PS-polyethylene / propylene-PS triblock copolymer), SEEPS (PS-polyethylene / ethylenepropylene-PS triblock copolymer), SB (PS-polybutadiene diblock copolymer), Examples thereof include SEB (PS-polyethylene / butadiene diblock copolymer), SEP (PS-polyethylene / propylene diblock copolymer), PS-polyvinyl acetate graft copolymer, and the like. These can be used alone or in combination.

  Examples of the polyamide-based resin include polyamide 6, polyamide 66, polyamide 612, polyamide 12 (nylon 12 (trademark)), polyamide 11, polyamide 610, and aromatic polyamide. These can be used alone or in combination.

Further, the flame retardant includes a phosphorus flame retardant and a nitrogen flame retardant.
Examples of the phosphorus flame retardant include organic phosphorus compounds such as phosphate esters and condensed phosphate esters, and inorganic phosphorus compounds such as red phosphorus, ammonium polyphosphate, and polyphosphate amide.

  Examples of the nitrogen-based flame retardant include melamine cyanurate, melamine sulfate, guanidine compound, tetrazole compound, ammonium compound and the like.

The optical fiber cord 8 of the present embodiment described above has the following effects.
The polymer alloy coated on the high tensile strength fiber 4 provided on the optical fiber core 6 has higher flame retardancy and self-extinguishing ability than the polyamide resin, the fluorine resin, or the polycarbonate. Furthermore, since expensive fluororesins are not used, material costs can be reduced.
In addition, since the polymer alloy does not contain halogen, an effect that no halogen-based harmful gas such as hydrogen chloride, chlorine, dioxin is generated is produced as compared with the PVC resin.
Further, since the polymer alloy does not contain a metal hydroxide, a bleeding phenomenon due to the formation of a deliquescent compound does not occur.
Compared with mixed compounds of flame retardant and Hytrel (trademark), the use of a low calorific value polymer alloy enables the use of a flame retardant to be used in a small amount, thus improving workability during coating. There is no reduction, and the manufacturing cost can be reduced.

  The outer coating layer 7 made of a polymer alloy in the optical fiber cord 8 is one layer in the present embodiment, but if the outer diameter of the optical fiber cord 8 does not exceed 3.0 mm, the layer bending resistance In order to improve performance, it is good also as a coating layer which consists of two or more layers.

<Example 1>
As shown in FIG. 1, a high strength fiber 4 made of Kevlar fiber (trademark) is vertically attached to an optical fiber core wire 6 having an outer diameter of 0.25 mm and an outer diameter of 0.9 mm. Covered. Furthermore, the outer coating layer 7 was further coated with a polymer alloy having the composition shown in FIG. The outer coating layer 7 was formed by extrusion coating a polymer alloy produced using a biaxial kneader into a tube shape with an extruder. The produced optical fiber cord 8 had an outer diameter of 2.0 mm.
From FIG. 2, the polymer alloy is 70 parts by weight of PPO (manufactured by GE Plastics) as polyphenylene ether, 20 parts by weight of SEBS (Clayton ™ 1651; manufactured by Shell) as a styrene resin, and PS (GP-PS; 10 parts by weight of A & M PS) was mixed, and the plurality of polymers were mixed.

The oxygen index and calorific value of this polymer alloy were determined. As shown in the lower part of FIG. 2, the results were an oxygen index of 23.5 and a calorific value of 24 kJ / g.
The oxygen index was determined according to JIS K 7201. The sample shape was 150 mm long × 6.5 mm wide × 3 mm thick, and was measured using an oxygen index measuring device manufactured by Toyo Seiki.
The calorific value was determined using an average combustion effective calorific value obtained from a combustion test conducted under the condition of a radiant heat of 50 kW / m ² using a cone calorimeter with a sample shape of 100 mm long × 100 mm wide × 3 mm thick.

  For the optical fiber cord 8 obtained in Example 1, (1) Flame retardancy and self-extinguishing ability determination experiment by JIS C3005 inclined combustion test, (2) Experiment for confirming the generation of harmful gases during combustion, (3) Bleed and deliquescence phenomenon An outbreak confirmation experiment was conducted. The results of these experiments are shown in FIG.

(1) JIS C3005 inclined combustion test About the flame retardance and self-extinguishing ability judgment experiment of the optical fiber cord 8 in Example 1, it implemented based on the standard JIS C3005. The experiment and determination method are as follows. The optical fiber cord 8 having a length of about 300 mm was inclined 60 degrees from the horizontal plane, and the upper end and the lower end of the cord were gripped. The tip of the burner's inner flame was applied to a position about 20 mm from the lower end of the cord until it burned within 30 seconds. After removing the burner, the degree of combustion was visually confirmed. Here, the burner flame was an inner flame of 35 mm and an outer flame of 130 mm. A sample that self-extinguished within 60 seconds without burning continued after removing the burner was evaluated as “pass”, and a sample that continued burning for 60 seconds or longer was determined as “failed”.

(2) Experiment for confirming generation of harmful gas during combustion A sample of 1000 mg was taken from the outer coating layer 7 of the optical fiber cord 8 and measured according to JIS C 3666-2. However, instead of measuring pH and conductivity, the anion contained in the solution was analyzed by ion chromatography. The case where the total of halogen ions was 900 ppm or less was designated as “none”, and the case where the total amount of halogen ions exceeded 900 ppm was designated as “present”.

(3) Bleed / Deliquesce Phenomenon Confirmation Experiment An experiment for confirming the occurrence of a bleed / deliquescent phenomenon of the optical fiber cord 8 in Example 1 was performed. The experiment and determination method are as follows. The manufactured optical fiber cord 8 having a length of 200 mm was exposed to 400 ppm of NO gas at room temperature for 48 hours, and then left in a constant temperature and humidity chamber at a temperature of 60 ° C. and a humidity of 90% for 2 hours. Then, the optical fiber cord 8 was taken out and the surface was visually observed to determine whether or not water droplets were generated on the surface. The case where water droplets did not occur was designated as “none”, and the case where water droplets occurred was designated as “present”.

  From FIG. 3, (1) “Pass” in the JIS C3005 inclined combustion test, (2) “None” in the toxic gas generation confirmation experiment during combustion, and (3) “None” in the bleed and deliquescence occurrence confirmation experiment. The example was “◯ (ie, passed)” as a result of comprehensive judgment, and the other examples were “x (ie, failed)”. The optical fiber cord 8 in Example 1 was a pass and the overall judgment was (◯) from (1) to (3).

<Example 2>
As shown in FIG. 2, the polymer alloy is composed of polyphenylene ether, a styrene resin, and a polyamide resin. The polymer alloy is 55 parts by weight of PPO (manufactured by GE Plastics) as the polyphenylene ether and SEBS (Clayton as the styrene resin). (Trademark) 1651 (made by Shell) is mixed with 10 parts by weight, and nylon 12 (trademark) (UBESTA3035; made by Ube Industries) as a polyamide-based resin is blended by 35 parts by weight. The oxygen index of the polymer alloy is 22.5, and the calorific value is 25 kJ. An optical fiber cord 8 was produced under the same conditions as in Example 1 except that the value was set to / g, and the same experiment as in Example 1 was performed.
The result of the experiment is shown in FIG.

<Example 3>
As shown in FIG. 2, the polymer alloy is composed of polyphenylene ether and a styrene resin. The polymer alloy includes 70 parts by weight of PPO (manufactured by GE Plastics) as the polyphenylene ether and SEBS (Clayton (trademark) as the styrene resin. 1651; made by Shell), 20 parts by weight of PS (GP-PS; made by A & M PS), and 15 parts by weight of condensed phosphate ester (PX200; made by Daihachi Chemical) as a phosphorus flame retardant An optical fiber cord 8 was produced under the same conditions as in Example 1 except that the oxygen index of the alloy was 29.0 and the calorific value was 22 kJ / g, and the same experiment as in Example 1 was performed.
The result of the experiment is shown in FIG.

<Example 4>
As shown in FIG. 2, the polymer alloy is composed of polyphenylene ether, styrene resin, and polyamide resin. The polymer alloy includes 55 parts by weight of PPO (manufactured by GE Plastics) as polyphenylene ether and SEBS (as styrene resin). 10 parts by weight of Clayton (trademark) 1651 (made by Shell), 35 parts by weight of nylon 12 (UBESTA3035; made by Ube Industries) as a polyamide-based resin, and 20 parts by weight of melamine cyanurate (MC640; made by Nissan Chemical) as a nitrogen-based flame retardant An optical fiber cord 8 was produced under the same conditions as in Example 1 except that the oxygen index of the polymer alloy was 27.5 and the calorific value was 23 kJ / g, and the same experiment as in Example 1 was performed. It was.
The result of the experiment is shown in FIG.

<Comparative Example 1>
As shown in FIG. 2, the optical fiber is the same as in Example 1 except that the outer coating is made of nylon 12 which is a polyamide resin, the oxygen index is 21.5, and the calorific value is 28.7 kJ / g. A cord was prepared and the same experiment as in Example 1 was performed.
As shown in FIG. 3, the optical fiber cord in Comparative Example 1 was “failed” in the JIS C3005 inclined combustion test.

<Comparative example 2>
As shown in FIG. 2, an optical fiber cord was produced under the same conditions as in Example 1 except that the outer coating was made of soft PVC, the oxygen index was 24.5, and the calorific value was 33.2 kJ / g. The same experiment as in Example 1 was performed.
As shown in FIG. 3, generation of HCl, which is a harmful gas, was confirmed in the optical fiber cord in Comparative Example 2. In addition, it was determined that there was “somewhat” in the occurrence of bleed and deliquescence.

<Comparative Example 3>
As shown in FIG. 2, the outer coating is made of a mixture obtained by adding metal hydroxide magnesium hydroxide (Kisuma 5A; manufactured by Kyowa Chemical) to polyolefin, and has an oxygen index of 29.0 and a calorific value of 35 kJ / g. In the above mixture, an optical fiber cord was prepared under the same conditions as in Example 1 except that 100 parts by weight of EEA (A714; manufactured by Mitsui DuPont) and 100 parts by weight of magnesium hydroxide were used. The same experiment as in Example 1 was performed.
As shown in FIG. 3, the optical fiber cord in Comparative Example 3 was determined to be “present” in the occurrence of bleed and deliquescence.

<Comparative Example 4>
As shown in FIG. 2, the outer coating is made of a thermoplastic polyester rubber elastic body (Hytrel; manufactured by Toray) to which a flame retardant is added, except that the oxygen index is 22.6 and the calorific value is 30.7 kJ / g. An optical fiber cord was produced under the same conditions as in Example 1, and the same experiment as in Example 1 was performed.
As shown in FIG. 3, the optical fiber cord in Comparative Example 4 was “failed” in the JIS C3005 inclined combustion test.

  In the optical fiber cord of the present invention, the outer coating layer provided on the outer periphery of the optical fiber core is made of a polymer alloy containing polyphenylene ether, the oxygen index of the polymer alloy is 21 or more, and the calorific value is 28 kJ / g or less. is there. It does not contain halogen substances or metal hydroxides, has high self-extinguishing ability, and does not generate harmful gases, bleed or deliquescence.

It is sectional drawing of the optical fiber cord of one Embodiment of this invention. It is the figure which showed the mixing | blending of the polymer in an Example and a comparative example, an oxygen index, and the emitted-heat amount. It is the figure which showed each result and comprehensive result of the JIS C3005 inclination combustion test in a Example and a comparative example, the harmful gas generation | occurrence | production confirmation experiment at the time of combustion, and a bleed and deliquescence generation | occurrence | production confirmation experiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Optical fiber 2 Ultraviolet curable resin 3 Thermoplastic resin 4 High tensile fiber 5 Optical fiber strand 6 Optical fiber core wire 7 Outer coating layer 8 Optical fiber cord

Claims (7)

An optical fiber cord having an outer coating layer on the outer periphery of the optical fiber core,
The outer coating layer is made of a polymer alloy containing polyphenylene ether, and the polymer alloy has an oxygen index of 21 or more and a calorific value of 28 kJ / g or less.   The optical fiber cord according to claim 1, wherein the polymer alloy includes a styrene resin.   The optical fiber cord according to claim 1, wherein the polymer alloy includes a styrene resin and a polyamide resin.   The optical fiber cord according to claim 2, wherein the polymer alloy is added with a phosphorus-based flame retardant.   The optical fiber cord according to claim 3, wherein the polymer alloy is added with a nitrogen-based flame retardant.   The optical fiber cord according to any one of claims 1 to 5, wherein a high tensile strength fiber is vertically attached between the optical fiber core wire and the outer coating layer. The outer diameter of the optical fiber core wire is in the range of 0.4 mm to 0.9 mm, and the outer diameter to the outer coating layer is in the range of 1.0 mm to 3.0 mm. The optical fiber cord described.

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