JP3290265B2 - Flame retardant plastic optical fiber cord - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant plastic optical fiber cord. The optical fiber cord of the present invention is suitable for optical signal communication between or within devices such as OA devices, illumination for medical devices, measurement / control sensors such as optical fiber switches, image transmission such as pattern transmission, and other fields such as decoration. Used for

[0002]

2. Description of the Related Art Plastic optical fibers are inferior to quartz-based optical fibers in terms of light transmission over a wide wavelength range and have high light transmission loss, but are excellent in workability.
Even with a large diameter and a large aperture ratio, it has excellent flexibility and small bending stress, and is therefore used in many industrial fields. The plastic optical fiber is made of a polymer having a high refractive index, such as polymethyl methacrylate, polycarbonate, polystyrene, poly-4-methylpentene-1, and a silicone-based polymer having a high light transmittance, and a vinylidene fluoride-based polymer. A sheath material (cladding) made of a polymer having a lower refractive index than the core material, such as a perfluoroalkyl methacrylate polymer or a methacrylate polymer.
It has a concentric form, and transmits the light incident from one end to the other end while repeating reflection by total reflection caused by a refractive index difference at the interface between the core and the clad, and transmitting the light to the other end. Gives heat resistance and strength,
For protection from water, chemicals, oxygen, light, etc., a polyethylene resin, a polypropylene resin, a polyamide resin, a polyvinyl chloride resin, a polyacetal resin, or the like is coated. In recent years, when plastic optical fiber cords are used for the above-mentioned various applications, the requirements for flame retardancy have become strict, and the standards for the flame retardancy have often been set. Correspondingly, in order to impart flame retardancy to the plastic optical fiber cord, a polyethylene resin composition containing a polyvinyl chloride resin, magnesium hydroxide or the like as an outer covering material has been proposed. However, when a polyvinyl chloride-based resin is used, the plasticizer tends to migrate to the core material and increase transmission loss. This tendency is more problematic especially at high temperature and high humidity. Further, when magnesium hydroxide is blended with a polyethylene resin, flame retardancy cannot be imparted unless a large amount of magnesium hydroxide of 60% or more of the composition is blended, and in this case, the coating speed becomes slow and the productivity becomes low. Poor, and the flexibility of the manufactured plastic optical fiber cord,
There is a problem with poor mechanical properties. In addition, since the coating must be performed at a high temperature, the plastic optical fiber of the core is deteriorated, and there is a problem that the light transmission property is deteriorated. on the other hand,
Plastic optical fiber cords are required not only for flame retardancy but also for performance when the cords are connected.
That is, at the time of connection, the covering layer at the end of the core of the plastic optical fiber must be cut and then stripped, and the core portion must be a bare wire exposed to about 1.5 to 2.5 mm. Use a tool that cuts the coating layer at right angles to the cord length direction and pulls the coating layer parallel to the cord length direction to strip the coating layer. There is a demand for a coating material that has a "stripable length", has no cut portion elongation, and has a long strippable length. In addition, a connector of a type in which the coating layer is fixed by caulking at the end of the cord is attached. When the connector and the cord are pulled, the strength at which the optical fiber starts to be pulled in from the connector end face must be higher than a reference value.

[0003]

As described above, recent plastic optical fiber cords have excellent flame retardancy,
Good coating processability, flexibility, excellent mechanical properties,
There is a demand for a coating layer having good strip characteristics at the time of connection and having excellent connector pull-out properties. Accordingly, an object of the present invention is to provide a plastic optical fiber cord satisfying all of these required characteristics.

[0004]

Means for Solving the Problems The present inventors have prepared a number of flame-retardant resin compositions by combining various polymers and various flame retardants and the like, coated these on plastic optical fiber bare wires, and evaluated them. The present inventors have found that the subject of the present invention can be solved only when a coating material is formed by combining a specific polymer and a specific flame retardant, and further studied and completed the present invention.

That is, according to the present invention, a plastic optical fiber bare wire having a plastic core is melted at a melt index of 0.5 to 7 g / 10 minutes and a density of 0.92 to 0.95 g.
/ Ml, ethylene having a vinyl acetate content of 5 to 25% by weight.
20-100 parts by weight of vinyl acetate copolymer, melt index 0.5-7 g / 10 min, density 0.915-0.
Polymer component 1 comprising 80 to 0 parts by weight of 930 g / ml high-pressure radical polymerization long-chain branched low-density ethylene polymer
00 parts by weight, brominated flame retardant 20 to 60 parts by weight, antimony trioxide 5 to 30 parts by weight, magnesium hydroxide 10 to 8
The present invention relates to a flame-retardant plastic optical fiber cord coated with a resin composition comprising 0 parts by weight.

In the present invention, the plastic optical fiber cord is a plastic optical fiber bare wire coated with a resin composition. The plastic of the plastic optical fiber bare wire means a thermoplastic resin having a high light refractive index and a high light transmittance, such as polymethyl methacrylate, polycarbonate, polystyrene, poly-4-methylpentene-1, and a silicone polymer. In addition, the bare plastic optical fiber has the above-mentioned plastic as a core, and is coated with a polymer such as a vinylidene fluoride-based polymer, a perfluoroalkyl methacrylate-based polymer, and a methacrylate-based polymer having a smaller light refractive index than the core. Means what you have.

The ethylene-vinyl acetate copolymer of the present invention has a melt index of 0.5 to 7 g / 10 minutes, a density of 0.92 to 0.95 g / ml, and a vinyl acetate content of 5 to 5.
25% by weight, giving excellent properties such as flexibility, workability, mechanical properties, low-temperature resistance, flame retardancy, filling properties such as flame retardants and antioxidants, and stripping properties. It is produced by a radical polymerization method. The melt index of this ethylene-vinyl acetate copolymer is 0.5 to
Although it is 7 g / 10 minutes, if it is less than 0.5 g / 10 minutes, processability and flexibility are poor, and if it exceeds 7 g / 10 minutes, mechanical properties are deteriorated, which is not desirable. The density is 0.92
However, when the content is less than 0.92 g / ml, the vinyl acetate content is less than 5%, and the flexibility, flame retardancy, filling property, etc. are poor. , Stripping property and the like are deteriorated, which is not desirable. Further, the vinyl acetate content is 5 to 25% by weight, but if it is less than 5% by weight, flexibility, flame retardancy, filling properties, low-temperature resistance, etc. are deteriorated. Properties, heat resistance, stripping properties, etc. are deteriorated, which is not desirable.

In the present invention, the high-pressure radical polymerization long-chain branched low-density ethylene polymer has a melt index of 0.5 to 7 g / 10 min and a density of 0.915 to 0.930.
g / ml, and imparts excellent properties in workability when coating the bare wire, connector pull-out property, cutting property, stripping property, and the like. -It is produced by a radical polymerization method using the same production equipment as the vinyl acetate copolymer. The melt index of this high-pressure radical polymerization long-chain branched low-density ethylene polymer is 0.5 to 7
g / 10 minutes, but less than 0.5 g / 10 minutes,
Workability is poor, and if it exceeds 7 g / 10 minutes, mechanical strength is low, which is not desirable. The density is 0.915 to 0.930
Although it is g / ml, if it is less than 0.915 g / ml, the mechanical strength is low, and if it exceeds 0.930 g / ml, it is difficult to manufacture, and it is not desirable.

An ethylene-vinyl acetate copolymer (hereinafter referred to as E
20 to 100 parts by weight of a high-pressure radical polymerization long-chain branched low-density ethylene polymer (hereinafter referred to as HP)
-LDPE) and 80 to 0 parts by weight in total.
The polymer component of the present invention is defined as 00 parts by weight. EVA
Is less than 20 parts by weight, flexibility, flame retardancy, filling properties,
Mechanical properties, low-temperature resistance, stripping properties, etc. deteriorate, which is not desirable. In addition, vinyl acetate (hereinafter also described as VA)
As the content increases, the amount of EVA used can be reduced. However, as the VA content approaches 5% by weight, the HP-LDP decreases.
The usage of E may be reduced. Examples of preferred amounts of both components used are 20 parts by weight of EVA having a VA content of 25% by weight, 80 parts by weight of HP-LDPE, and E having a VA content of 20% by weight.
25 parts by weight of VA, 75 parts by weight of HP-LDPE, 33 parts by weight of EVA having a VA content of 15% by weight, and HP-LDPE67
Parts by weight, 50 parts by weight of EVA having a VA content of 10% by weight and H
EVA with 50 parts by weight of P-LDPE and 7% by weight of VA
71 parts by weight, 29 parts by weight of HP-LDPE, VA content 6
83% by weight of EVA and 17 parts by weight of HP-LDPE. In the case of EVA having a VA content of 5% by weight, EVA100 is used.
Parts by weight (that is, 0 parts by weight of HP-LDPE). V
When using EVA with an A content other than 5% by weight, HP-
The use of LDPE is a mandatory requirement.

The brominated flame retardant in the present invention is a brominated aromatic, aliphatic, araliphatic or alicyclic compound such as decabromodiphenyl ether, hexabromobenzene, ethylenebistetrabromophthalimide, tris (2,3-dibromopropyl) isocyanurate, 2,2-bis (4-bromoethyl ether-3,
5-dibromophenyl) propane and the like, and these may be used alone or in combination of two or more. The brominated flame retardant is used in an amount of 20 to 60 parts by weight based on 100 parts by weight of the polymer component. If the amount is less than 20 parts by weight, the flame retardancy is insufficient. If the amount is more than 60 parts by weight, burning may occur at the time of combustion, and mechanical properties and flexibility may be deteriorated.

In the present invention, 5 to 30 parts by weight of antimony trioxide is blended with respect to 100 parts by weight of the polymer component. 5
If the amount is less than 30 parts by weight, the flame retardancy is insufficient. If the amount exceeds 30 parts by weight, the mechanical properties, low-temperature properties, workability, etc. are deteriorated, which is not desirable.

The magnesium hydroxide in the present invention is blended in an amount of 10 to 80 parts by weight based on 100 parts by weight of the polymer component.
Provides flame retardancy, halogen catcher properties, moderate hardness, etc. If the amount is less than 10 parts by weight, the flame retardancy is insufficient. When the polymer component is burned, Br ₂ or HBr generated from the brominated flame retardant cannot be caught and smoke generation cannot be suppressed. Poor mechanical properties, flexibility, low temperature properties, etc.
Not desirable.

The antimony trioxide, magnesium hydroxide, and the like used in the present invention are better dispersed in the resin component when used in powder form, and have smaller mechanical properties, abrasion resistance, heat resistance, and flexibility. The more you increase. The particle size of the powder is 0.1-2
It is preferably in the range of 0 μm, and particularly preferably the average particle size is 0.2 to 3 μm.
m is preferable. The surface of the powder is made of titanium to impart dispersibility to resin components, improve mechanical properties, abrasion resistance, carbon dioxide gas whitening resistance, moisture resistance, oil resistance, chemical resistance, workability, etc. It is preferable to treat with a coupling agent, a silicone coupling agent, an aluminum coupling agent, a saturated fatty acid, an unsaturated fatty acid, a metal salt thereof, a fatty acid ester, a fatty acid amide, or the like.

The resin composition of the present invention contains other resin components such as an ultra-low-density ethylene-α-olefin copolymer and linear ethylene-α as long as the properties of the plastic optical fiber cord of the present invention are not impaired. -Olefin copolymer, high-density polyethylene, ethylene-ethyl acrylate copolymer, ionomer, polypropylene, styrene-based elastomer and the like may be blended. In addition, known additives such as an antioxidant, a weather resistance improver, an ultraviolet absorber, a colorant, a pigment, a filler, a slip agent, an antiblocking agent, an antistatic agent, a crosslinking agent, and a flame retardant are added to the resin composition. In addition, a rust inhibitor, an antibacterial agent, a fragrance, a plasticizer, a processing aid, and the like may be blended within a range that does not impair the properties of the plastic optical fiber cord of the present invention.

The resin composition of the present invention is compounded and kneaded by, for example, a Banbury mixer, a Henschel mixer, a co-kneader, a multi-screw extruder, a ribbon blender, etc., and has an extrusion speed of 300 to 1000 m at a temperature lower than the softening point of the bare plastic optical fiber. / Min to produce the plastic optical fiber cord of the present invention. As a bare plastic optical fiber, the outer diameter is usually 0.2 to
About 1 mm is used, and the thickness of the coating layer of the resin composition is usually 0.2 to 2 mm. As a result, the outer diameter of the plastic optical fiber cord is usually in the range of 0.4 to 3 mm. However, it goes without saying that those outside this range are also included in the present invention.

The plastic optical fiber cord of the present invention is excellent in flame retardancy, flexibility, mechanical properties, low temperature resistance, cutting property and stripping property of a coating layer, connector pull-out property, etc., and is suitable for OA equipment (computer peripheral equipment, Personal computer, printer, copier, etc.), digital audio equipment, FA equipment (photoelectric switch, sequence controller, NC processing machine, semiconductor manufacturing equipment, etc.), optical signal communication between equipment such as automobiles or optical signal communication in equipment;
Lighting of home appliances and medical equipment (light guides); Optical fiber switches, mark sensors, defect detection, measurement and control sensors (sensor heads) for measuring signal transmission, etc .; Pattern transmission, image transmission such as video transmission (image guides,
Image scope); it can be used for decorative displays, sign boards, product displays, decoration of toys and the like.

[0017]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. Example 1 a. Preparation of resin composition Melt index 3.5 g / 10 min, density 0.93 g
/ Ml, 60 parts by weight of an ethylene-vinyl acetate copolymer having a vinyl acetate content of 10% by weight (manufactured by Nippon Unicar, manufactured by a high-pressure radical polymerization method), and a melt index of 2.3 g / 1
0 minutes, high pressure radical polymerization of 0.918 / ml density, 40 parts by weight of long chain branched low density polyethylene (manufactured by Nippon Unicar, manufactured by high pressure radical polymerization method), bromine flame retardant (decabromodiphenyl flame retardant, US ethyl) Product name, SAYTE
X8010) 40 parts by weight, antimony trioxide (Nippon Seiko)
20 parts by weight, magnesium hydroxide (Kyowa Chemical, trade name
KISMA 5B, average particle size 0.6-1.0 μm, surface treated with oleic acid) 25 parts by weight, carbon black master batch (manufactured by Nippon Unicar, 100 parts by weight of high-pressure polyethylene, 30 parts by weight of furnace black) And 0.5 parts by weight of an antioxidant (phenolic antioxidant, manufactured by Ciba-Geigy, trade name: IRGANOX 1010) were kneaded with a Banbury mixer at 180 ° C. for 10 minutes, and then granulated to a diameter of 3 mm and a length of 3 mm. Was obtained. b. Preparation / Evaluation Results of Test Specimens The pellets were preheated at 160 ° C. for 5 minutes by a hot press molding machine, and then pressed at 150 kg / cm ² for 3 minutes and molded to a thickness of 3 mm, 2 mm or 1 m.
m, 150 mm length, 180 mm width sheet
The tangled specimen (A-1) specified by K7201
No. 3) or a dumbbell-shaped test piece (No. 3) specified by JIS K6301 was punched out to obtain various test test pieces. Using these test pieces, various physical properties were determined according to the following measurement methods. -Tensile strength: 200 m using the dumbbell-shaped No. 3 test piece (1 mm) according to JIS C3005, Item 18.
The test is performed at a tensile speed of m / min, and the average value of five test pieces as one set is defined as the tensile strength. -Elongation: Using the dumbbell-shaped No. 3 test piece (1 mm), in accordance with JIS C3005, paragraph 18, the tensile speed is 200 mm / min, and the elongation is the average value of a set of five pieces. . -LOI: Using the above-mentioned A-1 test piece,
It is measured according to IS K7201. Heat aging: Using the above-mentioned dumbbell-shaped No. 3 test pieces (1 mm) in groups of five, the tensile strength residual ratio and the elongation residual ratio of the test pieces heated at an oven temperature of 100 ° C. for 4 days in accordance with JIS K7212 were measured. Ask. Evaluation results Tensile strength: 110 kg / cm ² · elongation: 500%, LOI: 34 - Heat Aging: Tensile strength retention of 93% elongation residual ratio 97% c. Manufacture of plastic optical fiber cord High purity polymethyl methacrylate (PMMA) as core material and sheath material of vinylidene fluoride-tetrafluoroethylene hexafluoropropylene copolymer (sheath material is coated to 50/1000 thickness of core diameter) )), A plastic optical fiber bare wire having a diameter of 1.0 mm was prepared. The bare wire is coated with the resin composition prepared in the above a from an extruder so as to have a thickness of 0.6 mm at a temperature of 135 ° C. and an outer diameter of 2.2 mm at a wire winding speed of 600 m / min. A plastic optical fiber was manufactured. d. Evaluation method and evaluation result of plastic optical fiber cord Evaluation method Elongation of cut portion at stripping: The coating layer at the end of the core of the plastic optical fiber is cut, then stripped, and the core portion is bare wire of about 1.5 to 2.5 mm. And when
A cut is made in the coating layer at right angles to the cord length direction, and when the coating layer is pulled and stripped, it is confirmed whether or not the cut portion of the coating layer has elongated. Strip success rate: The strip success rate is measured when the length from the cord end to the cut surface of the coating layer is 1 cm or 5 cm.・ Connector pull-out property: When a connector of the type that caulks and fixes the coating layer at the end of the cord is attached, and when the connector and the cord are pulled, the strength at which the fiber starts to be pulled in from the connector end face is measured and is 3.0 kg or more. Check whether or not. Flame retardancy: A horizontal combustion test and a vertical combustion test (VW-1) in UL-1581 are performed. Evaluation results-Elongation of cut portion at stripping: no elongation, good. -Strip success rate: 1 cm 100% success 5 cm 100% success-Connector pull-out property: The strength was 3.6 kg, which was good. -Flame retardancy: All tests passed, and sufficient flame retardancy was recognized.

Example 2 a. Preparation of resin composition Melt index 2.7 g / 10 min, density 0.94 g
/ Ml, 20 parts by weight of an ethylene-vinyl acetate copolymer having a vinyl acetate content of 23% by weight (manufactured by Nippon Unicar, manufactured by a high-pressure radical polymerization method), and a melt index of 1.3 g / 1
0 minutes, high pressure radical polymerization with a density of 0.923 / ml, 80 parts by weight of long chain branched low density polyethylene (manufactured by Nippon Unicar, manufactured by a high pressure radical polymerization method), bromine flame retardant (decabromodiphenyl flame retardant, ethyl in the United States) Product name, SAYTE
X8010) 20 parts by weight, antimony trioxide (Nippon Seiko)
30 parts by weight, magnesium hydroxide (Kyowa Chemical, trade name
KISMA 5B, average particle size 0.6 to 1.0 μm, surface treated with oleic acid) 10 parts by weight, carbon black masterbatch (manufactured by Nippon Unicar, 100 parts by weight of high-pressure polyethylene, 30 parts by weight of furnace black) 5 parts by weight Parts, 0.7 parts by weight of an antioxidant (phenolic antioxidant, Ciba-Geigy, IRGANOX 1010) were kneaded with a Banbury mixer at 180 ° C. for 10 minutes, then granulated and pelletized with a diameter of 3 mm and a length of 3 mm. I got b. Preparation and evaluation results of test pieces Two kinds of test pieces were prepared from the pellets in the same manner as in Example 1, and various physical properties were determined in the same manner as in Example 1. Tensile strength: 130 kg / cm ² · elongation: 600%, LOI: 33 - Heat Aging: Tensile strength retention 92% elongation residual ratio 90% c. Production of Plastic Optical Fiber Cord The same plastic optical fiber bare wire as in Example 1 was prepared. The bare wire is coated with the resin composition prepared in the above a from an extruder so as to have a thickness of 0.6 mm at a temperature of 135 ° C. and an outer diameter of 2.2 mm at a wire winding speed of 800 m / min. A plastic optical fiber was manufactured. d. Evaluation method and evaluation result of plastic optical fiber cord The plastic optical fiber cord was evaluated in the same manner as in Example 1. -Elongation of cut portion at stripping: no elongation, good. -Strip success rate: 1 cm 100% success 5 cm 100% success-Connector pull-out property: The strength was 3.8 kg, which was good. -Flame retardancy: All tests passed, and sufficient flame retardancy was recognized.

Example 3 a. Preparation of resin composition Melt index 0.9 g / 10 min, density 0.927
g / ml, 95 parts by weight of an ethylene-vinyl acetate copolymer having a vinyl acetate content of 5% by weight (manufactured by Nippon Unicar, manufactured by a high-pressure radical polymerization method), and a melt index of 4.6 g / 1
0 minutes, high-pressure radical polymerization of density 0.925 / ml 5 parts by weight of long-chain branched low-density polyethylene (manufactured by Nippon Unicar, manufactured by high-pressure radical polymerization method), bromine-based flame retardant (decabromodiphenyl-based flame retardant, US ethyl) Product name, SAYTEX
8010) 60 parts by weight, antimony trioxide (Nippon Seimitsu) 5
Parts by weight, magnesium hydroxide (Kyowa Chemical, trade name KIS
MA5B, average particle size 0.6-1.0 μm, surface treated with oleic acid) 50 parts by weight, carbon black masterbatch (manufactured by Nippon Unicar, 100 parts by weight of high pressure polyethylene, 30 parts by weight of furnace black blended) 20 parts by weight ,
0.9 parts by weight of an antioxidant (phenolic antioxidant, manufactured by Ciba-Geigy, IRGANOX 1010) was kneaded with a Banbury mixer at 180 ° C. for 10 minutes, and then granulated to give a diameter of 3 mm.
mm, and a pellet having a length of 3 mm was obtained. b. Preparation and evaluation results of test pieces Two kinds of test pieces were prepared from the pellets in the same manner as in Example 1, and various physical properties were determined in the same manner as in Example 1.・ Tensile strength: 150 kg / cm ²・ Elongation: 550% ・ LOI: 36 ・ Heat aging: Residual tensile strength 90% Residual elongation 93% c. Production of Plastic Optical Fiber Cord The same plastic optical fiber bare wire as in Example 1 was prepared. The bare wire is coated with the resin composition prepared in the above a from an extruder so as to have a thickness of 0.6 mm at a temperature of 135 ° C. and a wire winding speed of 300 m / min so as to have an outer diameter of 2.2 mm, A plastic optical fiber was manufactured. d. Evaluation method and evaluation result of plastic optical fiber cord The plastic optical fiber cord was evaluated in the same manner as in Example 1. -Elongation of cut portion at stripping: no elongation, good. -Strip success rate: 1 cm 100% success 5 cm 100% success-Connector pull-out property: The strength was 3.5 kg, which was good. -Flame retardancy: All tests passed, and sufficient flame retardancy was recognized.

Comparative Example 1 Example 1 was repeated except that the ethylene-vinyl acetate copolymer in Example 1 was not used and only a high-pressure radical polymerization long-chain branched low-density ethylene polymer was used as a polymer component.
When the same operation was performed, flexibility, low-temperature characteristics, mechanical characteristics, flame retardancy and the like were deteriorated. Comparative Example 2 The same operation as in Example 1 was performed, except that the ethylene-vinyl acetate copolymer in Example 1 was replaced with one having a vinyl acetate content of 30% by weight, the cut portion elongation at the time of stripping was 5 mm. And a part of the coating layer was adhered and left on the bare wire. Also, the extrusion coating speed was reduced to 400 m / min,
Productivity deteriorated. Comparative Example 3 The same operation as in Example 1 was performed except that the amount of the brominated flame retardant in Example 1 was changed to 15 parts by weight, and the flame retardancy was insufficient. Comparative Example 4 The same operation as in Example 1 was carried out except that the amount of antimony trioxide in Example 1 was changed to 3 parts by weight, the flame retardancy was insufficient, and the stripping property was somewhat insufficient. there were. Comparative Example 5 The same operation as in Example 1 was performed, except that the amount of antimony trioxide in Example 1 was changed to 35 parts by weight,
The mechanical properties deteriorated and the coating speed decreased. Comparative Example 6 The same operation as in Example 1 was performed, except that the amount of magnesium hydroxide in Example 1 was changed to 7 parts by weight,
The flame retardancy was insufficient, the amount of smoke was increased, and the weather resistance and cutting properties were deteriorated. Comparative Example 7 The same operation as in Example 1 was carried out except that the amount of magnesium hydroxide in Example 1 was changed to 90 parts by weight, the mechanical properties, flexibility, low-temperature resistance and the like were deteriorated, and the coating was performed. The speed is very slow.

[0021]

As described in detail above, the present invention provides
Using ethylene-vinyl acetate copolymer and high-pressure radical polymerization long-chain branched low-density ethylene polymer as the polymer component, bromine-based flame retardant, antimony trioxide and magnesium hydroxide as the flame retardant component, Uses a resin composition blended in a specific amount in a well-balanced manner as a coating material for bare plastic optical fiber, so that the resulting plastic optical fiber cord has flame retardancy, flexibility, mechanical properties, low temperature resistance, and coating. Layer cutting properties
It is particularly excellent in stripping properties, connector pullout properties, etc., and it can be extrusion coated at a temperature considerably lower than the softening point of the core plastic, so it has good light transmission properties and high resistance to light, heat, halogen gas, etc. . Therefore, the plastic optical fiber cord of the present invention having such excellent characteristics can be used for optical signal communication between or within devices such as OA devices, illumination of medical devices, measurement / control sensors such as optical fiber switches, and pattern transmission. It can be suitably used in a wide range of fields such as image transmission and other decoration.

────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI C08L 23/04 C08L 23/04 23/08 23/08 (56) References JP-A-60-21012 (JP, A) JP-A JP-A-62-292846 (JP, A) JP-A-63-77958 (JP, A) JP-A-4-248506 (JP, A) JP-A-58-79040 (JP, A) (58) Fields investigated (Int) .Cl. ⁷ , DB name) G02B 6/00 G02B 6/44 C08K 3/00-13/08 C08L 1/00-101/16

Claims (1)

(57) [Claims] 1. A plastic optical fiber bare wire having a plastic core as a core having a melt index of 0.5 to 7 g /
10 to 20 parts by weight of an ethylene-vinyl acetate copolymer having a density of 0.92 to 0.95 g / ml and a vinyl acetate content of 5 to 25% by weight, and a melt index of 0.5 to 7
g / 10 minutes, high-pressure radical polymerization long-chain branched low-density ethylene polymer 80 having a density of 0.915 to 0.930 g / ml 80
To 0 parts by weight of the polymer component, 20 to 60 parts by weight of a brominated flame retardant, 5 to 30 parts by weight of antimony trioxide, and 10 to 80 parts by weight of magnesium hydroxide. Flame retardant plastic optical fiber cord.