JPH0933770A - Optical fiber core or cord - Google Patents

Abstract

(57) 【Abstract】 PROBLEM TO BE SOLVED: To satisfy various characteristics such as heat resistance, cold resistance and mechanical characteristics required for an optical fiber core wire or cord, and to elute heavy metal compounds, a large amount of smoke and corrosive gas at the time of disposal. An optical fiber core wire or a cord that does not generate SOLUTION: A styrene-based thermoplastic elastomer (a2) 40-80 having 20% by weight or more of a polypropylene-based resin (a1), polystyrene as a hard segment, and hydride of a butadiene and / or isoprene (co) polymer as a soft segment. 30 to 70 parts by weight of ammonium polyphosphate flame retardant (B) or 80 to 120 parts by weight of metal hydrate (C) is mixed with 100 parts by weight of resin component (A) containing 100% by weight. An optical fiber core wire or a cord in which a coating layer 2 of the composition is formed on the outer circumference of the optical fiber strand 1 and / or the core wire.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an optical fiber core wire and an optical fiber cord, and more specifically, it has excellent flexibility, tensile properties, abrasion resistance, flame resistance, heat resistance and cold resistance. The present invention relates to an optical fiber core wire and a cord which do not generate heavy metal compounds, a large amount of smoke, and a corrosive gas when they are discarded such as landfill and burning.

[0002]

2. Description of the Related Art Optical fiber cores or cords have various properties such as tensile properties, mechanical properties such as wear resistance, flexibility, flame retardancy, heat resistance and cold resistance. Characteristics are required. Therefore, as a coating material for the optical fiber core wire or the cord, for example, an ethylene / vinyl acetate copolymer blended with a polyvinyl chloride compound or a halogen-based flame retardant, an ethylene / ethyl acrylate copolymer, an ethylene / propylene rubber, or the like is used. A composition containing an ethylene-based copolymer or a mixture of the copolymer and polyethylene as a main component is used. In recent years, when coating materials containing polyvinyl chloride and halogen-based flame retardants are discarded without proper treatment, the plasticizers and heavy metal stabilizers contained in them are eluted and a large amount of smoke and corrosive gases are generated. The problem of occurrence has been discussed, and a non-halogen flame-retardant coating material in which a metal hydrate is highly filled instead of a coating material containing polyvinyl chloride or a halogen-based flame retardant is being studied. These non-halogen flame-retardant coating materials are required to be highly filled with metal hydrates, and ethylene-vinyl acetate copolymers, ethylene-ethyl acrylate copolymers, and ethylene-based copolymers such as ethylene-propylene rubber are used. Used as a base polymer.

However, the tensile strength of these coating materials is about 10 MPa and the melting point is about 100 ° C., so that the characteristics of the polyvinyl chloride compound (tensile strength of 15 to 20) which is mainly used as a coating material for optical fiber cords at present.
However, the required characteristics were not satisfied as compared with the case of a MPa, 120 ° C. heat deformation rate of about 10%). In order to solve such problems, examples of compositions and electric wires using a polypropylene-based resin as a base polymer, which has excellent mechanical strength and heat resistance, are disclosed in JP-A-62-131052 and JP-A-6-7.
Although disclosed in Japanese Patent No. 6645, the flexibility and cold resistance of optical fiber cores or cords coated with these are problems.

Specifically, the optical fiber core wire or cord coated with these buckles during wiring or connection, and particularly in the optical fiber cord, the coating material shrinks in a low temperature region of 0 ° C. or less, There has been a problem that the center optical fiber core is bent and the transmission loss is increased.
The present invention solves the above problems and has excellent tensile properties, wear resistance, flexibility, flame retardancy, heat resistance, and cold resistance, and elution of heavy metal compounds at the time of disposal such as landfill and combustion. Another object of the present invention is to provide an optical fiber core wire or cord that does not generate a large amount of smoke or corrosive gas.

[0005]

In order to achieve the above object, in the present invention, (1) 20% by weight or more of polypropylene resin (a1), polystyrene as a hard segment, and butadiene and / or isoprene as a soft segment. 40-80% by weight of styrene-based thermoplastic elastomer (a2) having hydride of (co) polymer
A composition comprising 30 to 70 parts by weight of an ammonium polyphosphate flame retardant (B) or 80 to 120 parts by weight of a metal hydrate (C) based on 100 parts by weight of a resin component (A) containing Is formed on the outer periphery of the optical fiber elemental wire and / or the outer periphery of the optical fiber optical fiber in which tensile strength fibers are vertically attached or twisted, (2) Polypropylene type Resin (a1) 20
Resin component (A) 100 containing 40% to 80% by weight of polystyrene as a hard segment and 40 to 80% by weight of a styrene-based thermoplastic elastomer (a2) having hydride of butadiene and / or isoprene (co) polymer as a soft segment. 30 parts by weight of a mixture of ammonium polyphosphate flame retardant and metal hydrate (D) based on parts by weight.
An optical fiber, characterized in that a coating of a composition containing 120 parts by weight is formed on the outer circumference of an optical fiber element wire and / or the outer circumference of an optical fiber core wire in which tensile strength fibers are vertically attached or twisted. Cord or cord, (3) The resin component (A) contains an ethylene copolymer (a3) in a range of 30% by weight or less, the light according to (1) or (2). Fiber core or cord, and (4)
The shrinkage force of the composition when the temperature is lowered from room temperature to −20 ° C. is 5 MPa or less, (1), (2) or (3), the optical fiber core wire or the cord. Will be provided.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
First, each component constituting the coating composition used for the optical fiber core wire or the cord of the present invention and its mixing ratio will be described. (A1) Polypropylene resin As the polypropylene resin used in the present invention, polypropylene homopolymer, ethylene / propylene block copolymer, ethylene / propylene random copolymer, propylene / 1-butene block copolymer, propylene / 1-butene random copolymer, propylene / 4
-Methylpentene-1 block copolymer, propylene
One or two or more resins selected from 4-methylpentene-1 random copolymer, propylene / 1-hexene block copolymer, propylene / 1-hexene random copolymer and the like can be used in combination. Of these, ethylene / propylene block copolymers and ethylene / propylene random copolymers are preferable. Melt flow rate (MFR) of ethylene / propylene block copolymer and ethylene / propylene random copolymer
Is preferably in the range of 0.5 to 15 g / 10 minutes (load 2.16 kgf, temperature 230 ° C.).

(A2) Styrenic Thermoplastic Elastomer The styrene thermoplastic elastomer used in the present invention has polystyrene as a hard segment and butadiene and / or isoprene (co) polymer hydride as a soft segment. This is a hydrogenated block-shaped copolymer composed of a block segment A made of polystyrene and a homopolymer of butadiene or isoprene or a block B made of a copolymer thereof. As the block A, polystyrene, poly o-methyl styrene, poly m-methyl styrene, poly p-methyl styrene, poly α-methyl styrene, poly β-methyl styrene, polydimethyl styrene, poly trimethyl styrene, etc. are used as the block B. Examples include polybutadiene, polyisoprene, butadiene-isoprene copolymer, and the like.

In addition to the ABA type triblock copolymer, the styrene-based thermoplastic elastomer (a2) includes the block B'in which the vinyl bond amount of the block B is reduced in order to improve the fluidity. It is also possible to use the A-B-B 'type triblock copolymer used, and it is also possible to combine two or more thereof. The hydrides of these block copolymers are preferably those in which block A is hardly hydrogenated and blocks B and B ′ are selectively hydrogenated. As such, "KR
"ATON" (trade name, manufactured by SHELL), "Dynaron" (trade name, manufactured by Japan Synthetic Rubber Co., Ltd.) and the like are commercially available.

The composition for coating an optical fiber core wire or a cord of the present invention contains an ammonium polyphosphate flame retardant and / or a metal hydrate for imparting flame retardancy. Ammonium Polyphosphate Flame Retardant In the present invention, ammonium polyphosphate containing a nitrogen-containing compound such as tris- (2-hydroxyethyl) isocyanurate, melamine and polyphosphoric acid amide as the ammonium polyphosphate flame retardant (phosphorus flame retardant). Is used. An example of this is "Hostafl
am AP745 ”(trade name, manufactured by HOECHST),
"Sumisafe PM" (trade name, manufactured by Sumitomo Chemical Co., Ltd.) is commercially available.

Metal Hydrate As the metal hydrate, there are inorganic compounds having a hydroxyl group or crystal water such as aluminum hydroxide, magnesium hydroxide, hydrated aluminum silicate, hydrated magnesium silicate, basic magnesium carbonate and hydrotalcite. These can be used alone or in combination of two or more. Of these metal hydrates, magnesium hydroxide is preferable, and one subjected to surface treatment is particularly preferable. As such, commercially available products such as "Kisuma 5, 5A, 5B, 5E, 5J" (trade name, manufactured by Kyowa Chemical Co., Ltd.) can be used.

These ammonium polyphosphate flame retardants,
In order to enhance the flame retardant effect of metal hydrate, "SFR-10
It is also possible to blend a silicone compound such as "0" (trade name, manufactured by GENERAL ELECTRIC) and a quartz glass filler such as "Crystallite, Hugh Rex" (trade name, manufactured by Tatsumori). Further, in order to improve the deterioration of mechanical properties when using a metal hydrate or quartz glass filler, a polyolefin such as "N polymer" (trade name, manufactured by Nippon Petrochemical Co., Ltd.) is used as an unsaturated carboxylic acid or its derivative. You may use the modified polyolefin modified by.

(A3) Ethylene Copolymer Further, for the purpose of reducing smoke generation or improving flame retardancy of the optical fiber core wire or cord of the present invention,
Ethylene / vinyl acetate copolymer (EVA), ethylene /
Ethyl acrylate copolymer (EEA), ethylene / methyl acrylate copolymer (EMA), ethylene / methyl methacrylate copolymer (EMMA), ethylene / acrylic acid copolymer (EAA), ethylene / methacrylic acid copolymer The ethylene-based copolymer (a3) such as a polymer (EMAA) can be blended in the resin component in an amount of less than 30% by weight. Among these ethylene-based copolymers, EV
A and EEA are preferable. Ethylene copolymer MFR
Is preferably in the range of 0.5 to 10 g / 10 minutes (load 2.16 kgf, temperature 190 ° C.).

Next, each of the polypropylene resin (a1), the styrene thermoplastic elastomer (a2), the ethylene copolymer (a3), the ammonium polyphosphate flame retardant, and the metal hydrate in the coating composition. The mixing ratio of will be described. The proportion of the polypropylene resin (a1) used in the composition is 20% by weight or more of the total amount of the resin component (A), that is, the resin component including polypropylene resin, styrene thermoplastic elastomer, ethylene copolymer and the like. And 25 to 50% by weight is preferable.
When this ratio is 20% by weight or more, the optical fiber core wire or cord coated with the composition has good mechanical properties such as wear resistance and tensile properties, and the conventional optical fiber core coated with polyvinyl chloride. Excellent heat resistance, such as heat deformation rate and heat aging characteristics, compared to wire or cord.

Styrenic thermoplastic elastomer (a2)
The ratio is 40 to 80% by weight in the resin component (A), and the preferable range is 50 to 70% by weight. The ratio of styrene-based thermoplastic elastomer in the resin component is 4
If the amount is less than 0% by weight, the flexibility and cold resistance of the optical fiber core wire or cord become a problem as in the case of the conventional coating material. On the other hand, when this ratio exceeds 80% by weight, the fluidity of the material is significantly reduced, which causes a problem in extrusion moldability and makes it difficult to coat the outer circumference of the optical fiber core wire or the cord with extrusion.

The proportion of the ammonium polyphosphate flame retardant (B) is 30 to 100 parts by weight of the resin component (A).
70 parts by weight, preferably 40-60 parts by weight. If the amount is less than 30 parts by weight, the flame retardance required for the optical fiber cord cannot be obtained. On the other hand, if it exceeds 70 parts by weight, smoke and gas generated during combustion increase, which is not preferable. The ratio of the metal hydrate (C) is the resin component (A) 10
It is 80 to 120 parts by weight, preferably 95 to 105 parts by weight, relative to 0 parts by weight. If the compounded amount of the metal hydrate is less than 80 parts by weight, sufficient flame retardancy cannot be obtained as the optical fiber core wire or the optical fiber cord. On the other hand, 1
If it exceeds 20 parts by weight, mechanical properties such as abrasion resistance and tensile properties are deteriorated, and there is a problem in extrusion processability, which is not preferable. The ratio of the ammonium polyphosphate flame retardant and the metal hydrate mixture (D) is 100% by weight of the resin component (A).
It is 30 to 120 parts by weight, preferably 50 to 100 parts by weight, based on parts by weight. If the amount is less than 30 parts by weight, sufficient flame retardancy required for the optical fiber core wire or the cord cannot be obtained. On the other hand, when it exceeds 120 parts by weight, mechanical properties such as abrasion resistance and tensile properties are deteriorated and a problem occurs in extrusion moldability, which is not preferable.

The blending of the ethylene-based copolymer (a3) makes it possible to further improve the smoke generation property and flame retardancy of the coating composition. However, the proportion thereof is preferably less than 30% by weight in the resin component (A), and more preferably 5 to 25% by weight. 3
If it is 0% by weight or more, the heat resistance of the optical fiber core or the cord, such as the heat deformation rate and the heat aging characteristics, may deteriorate. Further, carbon black, red phosphorus or the like may be added to the coating composition in order to improve the flame retardancy of the obtained optical fiber core wire or cord. Moreover, you may add antioxidant, a ultraviolet absorber, a copper damage inhibitor, a dispersing agent, a pigment, etc. as needed.

Further, the composition used as the coating material for the optical fiber core wire or the cord of the present invention is from room temperature to −20.
It is preferable that the shrinkage force when the temperature is lowered to ° C is 5 MPa or less. For example, when an optical fiber cord having a loose structure as shown in FIG. 2 is used in a place close to an outdoor environment, the conventional polypropylene resin composition shrinks when the temperature drops from room temperature to a low temperature of −20 ° C. Power is 5
Since the pressure is higher than MPa, the center optical fiber core is bent due to the contracting force of the coating material, and 0.1 at the wavelength of 1.3 μm.
The transmission loss increases by more than dB. In order to eliminate this increase in transmission loss when the temperature drops, it is usually necessary to set the shrinkage force of the coating material when the temperature drops to 5 MPa or less.

The low temperature shrinkage force of the coating material can be measured as follows. (Method) Using a tensile tester conforming to JIS K7113 (1981), put the gripping part in a constant temperature bath, and strip a strip of the above composition (length 50 mm, width 2.5 m).
m, thickness 2 mm), or tubular pieces 20 mm apart, attached to the grip. Then, the temperature inside the thermostatic chamber is set to + 20 ° C., and the test piece is set at a speed of 5 mm / min or less so that the tensile stress of the tensile chart becomes 0 kg. From this state, the force generated by the contraction of the material when the temperature in the constant temperature bath was lowered to -20 ° C in 1 hour from the chart was read from the chart, and the force per unit cross-sectional area was taken as the low temperature contraction force of the material.

The coating composition used for the optical fiber core wire or cord of the present invention can be obtained by melt-kneading the above-mentioned components. To melt and knead each component,
Biaxial kneading extruder, pressure kneader, Banbury mixer,
A known device such as a roll can be used. The polypropylene resin, the styrene thermoplastic elastomer, the ethylene copolymer, the ammonium polyphosphate flame retardant, and the metal hydrate components may be kneaded in any order, and after dry blending at room temperature. You may melt-knead.

The optical fiber core wire or cord of the present invention is produced by using a general-purpose extrusion coating device, by using the above-mentioned composition as a coating layer, around the optical fiber strand, or by vertically attaching or twisting tensile strength fibers. It is manufactured by extrusion coating around the optical fiber core. At this time, the temperature of the extrusion coating apparatus is preferably about 180 ° C. in the cylinder part and about 180 to 200 ° C. in the crosshead part. The optical fiber core wire of the present invention may be used as it is without further providing a coating layer around it depending on the application. The optical fiber core wire or cord of the present invention includes, as a coating layer of the above-mentioned composition, all those coated on the outer circumference of the optical fiber element wire or core wire, and does not particularly limit the structure thereof. . The thickness of the coating layer, the type and amount of the tensile strength fiber to be longitudinally attached to or twisted with the optical fiber core wire may vary depending on the type and use of the optical fiber cord and can be appropriately set.

1 to 3 show structural examples of the optical fiber core wire and the cord of the present invention. FIG. 1 is a cross-sectional view of an embodiment of an optical fiber core wire of the present invention in which a coating layer 2 made of a coating composition is directly provided on the outer circumference of an optical fiber element wire 1. FIG.
It is sectional drawing of one Example of the optical fiber cord of this invention which formed the coating layer 5 on the outer periphery of the one optical fiber core wire 3 with which the some tensile strength fiber 4 was vertically attached. FIG. 3 shows an optical fiber cord of the present invention (optical fiber two-core cord) in which a plurality of tensile strength fibers 4 are vertically attached to the outer peripheries of two optical fiber core wires 3 and 3 and a coating layer 6 is further formed on the outer periphery thereof. 2) is a cross-sectional view of one embodiment of FIG.

[0022]

EXAMPLES The present invention will be described in more detail with reference to Examples and Comparative Examples. Examples 1 to 15 and Comparative Examples 1 to 11 The components shown in Tables 1 to 4 were each dry blended at a blending ratio at room temperature, and a kneading temperature of 180 was obtained using a pressure kneader.
The composition (coating material) corresponding to each of the examples and comparative examples was obtained by melt-kneading at a temperature of 15 ° C. for 15 minutes. Next, using a general-purpose extrusion coating device, the obtained composition was applied to the outer circumference of an optical fiber nylon core wire (3) having an outer diameter (φ) of 0.90 mm, to which tensile strength fibers (aramid fibers) (4) were attached. The optical fiber cord of the structure of FIG. 2 extruded and coated with a thickness of 0.35 mm, and the composition of the structure of FIG. 1 in which the composition is directly coated on the optical fiber element wire (1) of φ0.25 mm to have an outer diameter of 0.9 mm. An optical fiber core wire was produced. The tensile properties were evaluated by measuring the tensile strength (MPa) and elongation (%) of the coating layer of each optical fiber cord in a tensile test. The test conditions are 25 mm between marked lines and 200 mm pulling speed /
min.

The heat resistance and cold resistance of each optical fiber cord are
It was evaluated by the heat deformation test and the loss increase during the heat cycle test after coating the optical fiber cord having the structure of FIG. The heating deformation test of optical fiber cord is JIS C
The evaluation was performed according to the insulator heat deformation test of 3005. Test temperature is 120 ° C, load is 306gf, deformation rate is 30%
The following items were passed (○). The heat cycle test is performed for 4 cycles at a temperature of −20 to 80 ° C.
Heat resistance ◯, -20 to 0 when the transmission loss at a measurement wavelength of 1.3 μm in the high temperature region of ℃ is 0.05 dB / km or less.
When the transmission loss at the measurement wavelength of 1.3 μm in the low temperature region of ° C was 0.05 dB / km or less, the cold resistance was evaluated as ◯.

The wear resistance is determined by the automobile standard (JASO
Based on the blade reciprocating method of the abrasion resistance test of D611-86), the amount of wear reduction (mm) was measured by reciprocating the sheet piece of each coating composition with a blade over a length of 10 mm or more in the axial direction. The blade used had a piano wire with a diameter of 0.75 mm attached to the tip, and the weight was 700 gf.
Then, a blade having a wear reduction amount of 0.50 mm or less when the blade was reciprocated at a speed of 60 times per minute was regarded as a pass (◯). Regarding the flame retardancy, an optical fiber element wire (1) with a diameter of 0.25 mm was coated with the composition to have an outer diameter of 0.9 mm.
Regarding the optical fiber core wire of the structure of JIS C3005
It was evaluated according to. The flame contact time was set to 15 seconds, and the time taken for the flame of the optical fiber core wire to spontaneously disappear after the burner flame was removed was measured. 5 sample tests and all 30
Those that disappeared within seconds were passed (○).

The smoke emission property was evaluated by preparing a hot press sheet of each coating material and conducting an NBS smoke emission test. A sample having a specific optical density of 125 or less was evaluated as ◯, a sample having a specific optical density of 125 to 175 was evaluated as Δ, and a sample having a specific optical density of 175 or more was evaluated as x.

Regarding the extrusion processability, the cylinder diameter is 3
Cylinder temperature 180 using 5 mm extrusion coating equipment
℃, crosshead temperature 200 ℃, 0.9 as shown in Figure 2
A tensile strength fiber (Kevlar) is vertically attached around the 0 mmφ optical fiber core, and the composition has a thickness of 0.35 mm on the outer circumference.
When the extrusion coating is performed with, the optical fiber cord with a good appearance can be obtained. The extrusion coating speed of 50 m / min or more is ○, 50
Those of less than m / min were marked with x.

The following components were used as the components shown in Tables 1 to 4. (01) Ube Industries, Ltd. ethylene / propylene random copolymer; MFR 5g / 10 minutes (230 ° C, 2.16k)
gf) Product name RF338A (02) Ube Industries, Ltd. ethylene / propylene block copolymer; MFR 3g / 10 minutes (230 ° C, 2.16k)
gf) Trade name J903HK (03) SHELL company styrene thermoplastic elastomer; MFR 10g / 10 minutes (200 ° C., 5 kgf) Trade name Kraton G1652 (04) Nippon Synthetic Rubber Company styrene thermoplastic elastomer MFR 3.5g / 10 Min (230 ℃, 2.16
kgf) Trade name Dynaron 1320P (05) Mitsui DuPont Polychemical Co., Ltd. Ethylene / vinyl acetate copolymer; MFR 1.0 g / 10 min (190
℃, 2.16kgf) Vinyl acetate content 28wt% Brand name Evaflex EV-270

(06) Mitsui DuPont Polychemical Co., Ltd.
Ethylene / ethyl acrylate copolymer; MFR 0.5g
/ 10 minutes (190 ° C, 2.16 kgf) Vinyl acetate content 15 wt% Product name Evaflex A-710 (07) Nippon Petrochemical Co., Ltd. Modified polyolefin; MF
R 1.0 g / 10 min (190 ° C., 2.16 kgf) Trade name N polymer L6100M (08) Nippon Synthetic Rubber Co., Ltd. ethylene propylene rubber; Trade name EP01P (09) Riken Vinyl Industry Co., Ltd. polyvinyl chloride compound; Trade name IG-5071 (10) Sumitomo Chemical Co., Ltd. ammonium polyphosphate flame retardant A; trade name Sumisafe PM (11) HOECHST Co. ammonium polyphosphate flame retardant B; trade name HOSTAFLAM AP745 (12) Kyowa Chemical Industry Co., Ltd. hydroxide Magnesium; Trade name Kisuma 5A (13) GENERAL ELECTRIC Silicone; Trade name SFR-100 (14) CIBA-GEIGY pentaerythrityl-tetrakis [3- (3,5-di-
t-butyl-4-hydroxyphenyl) propionate]; trade name IRGANOX1010

[0029]

[Table 1]

[0030]

[Table 2]

[0031]

[Table 3]

[0032]

[Table 4]

From the results of Tables 1 to 4, the following can be seen. Comparative Example 1 is an example in which polyvinyl chloride compound is used as a coating material and is excellent in various characteristics, but there is a problem that a large amount of smoke and corrosive gas are generated during its combustion. Comparative Example 2 is an example using only an ethylene / propylene random copolymer as the base polymer. This product is coated with a halogen-free flame-retardant material with excellent mechanical strength, but when it is used as an optical fiber core wire or cord, it has a problem of flexibility at low temperatures. Especially when it is used as an optical fiber cord, it has a low temperature range. However, there is a problem that the transmission loss increases significantly. Comparative Example 3 is an example in which an ethylene / vinyl acetate copolymer is used as the base polymer of the coating composition and magnesium hydroxide is used as the flame retardant. Although a modified polyolefin is blended for the purpose of improving the compatibility between the base polymer and the metal hydrate, there is a problem that mechanical properties such as tensile properties and abrasion resistance are low. Further, depending on the base polymer, the heat resistance is low.

In Comparative Examples 4 and 5, the compounding amount of the styrene thermoplastic elastomer is outside the range of the present invention.
From the comparison between Comparative Example 4 and Example 1, when the blending amount of the styrene-based thermoplastic elastomer is less than 40% by weight of the resin component, the tensile strength is improved, but the increase in transmission loss in the low temperature region is not improved. Recognize. Comparative Example 5
From the comparison between Example 2 and Example 2, when the blending amount of the styrene-based thermoplastic elastomer exceeds 80% by weight, the increase of transmission loss in the low temperature region is improved, while the decrease of the tensile light intensity and the extrusion processability are improved. It can be seen that the decrease of the value becomes a problem.

Comparative Example 6 is an example in which ethylene / propylene rubber was blended without blending the styrene thermoplastic elastomer. As can be seen by comparison with Examples 3 and 4,
Low tensile strength.

In Comparative Examples 7 and 8, the compounding amount of the ammonium polyphosphate flame retardant was outside the range of the present invention. As can be seen by comparison with Examples 3 and 4, when the compounding amount of the ammonium polyphosphate flame retardant is less than 30 parts by weight with respect to 100 parts by weight of the resin component, the self-extinguishing time in the combustion test increases. When the amount of the flame-retardant agent exceeds 70 parts by weight, smoke generation becomes a problem, which is no different from that of the polyvinyl chloride compound of Comparative Example 1 having a problem.

Comparative Examples 9 and 10 are examples in which a metal hydrate was used as a flame retardant in an amount outside the range of the present invention.
By comparison with Examples 5 and 6, when the compounded amount of the metal hydrate was less than 80 parts by weight with respect to 100 parts by weight of the resin component,
If there is a problem with flame retardancy and it exceeds 120 parts by weight,
It can be seen that there arises a problem that mechanical properties such as tensile properties and wear resistance deteriorate. Comparative Example 11 is an example in which the blending amount of the ethylene copolymer exceeds 30% by weight in the resin component. Comparing with Example 11, it can be seen that when the blending amount of the ethylene copolymer is increased, the tensile property improved by using the polypropylene resin is deteriorated.

Example 7 is an example in which an ethylene / propylene block copolymer was used as the polypropylene resin. It will be appreciated that block copolymers can be used as well as random copolymers. When importance is attached to the heat resistance of the coating material, a block copolymer is preferable.
Example 8 is a styrene-based thermoplastic elastomer,
This is an example of using an ABA type. Compared with the A-B-B 'type used in other examples, the extrusion processability is slightly lowered, but the level is not a problem as a coating material, and the tensile strength is improved. In Example 9, as a styrene-based thermoplastic elastomer, ABA, A-
This is an example in which two types of BB ′ type are used, and it is possible to have high mechanical properties of the ABA type and excellent molding processability of the ABB ′ type.

Example 10 is an example in which ammonium polyphosphate flame retardants having different nitrogen-containing compounds are used, but no problem is observed in characteristics. Example 13 is an example in which an ammonium polyphosphate flame retardant and a silicone compound are used in combination. It can be seen that the use of the silicone compound as the coating material improves the flame retardancy of the optical fiber core wire or the cord of the present invention. Example 14 is an example of blending a modified polyolefin in a system using a metal hydrate as a flame retardant, and blending the modified polyolefin for the purpose of improving the compatibility between the base polymer and the metal hydrate. Is also possible.

[0040]

INDUSTRIAL APPLICABILITY The present invention relates to a styrene-based thermoplastic resin having a polypropylene resin (a1) and polystyrene as the hard segment, and butadiene and / or isoprene (co) polymer hydride as the soft segment, which are used in specific ratios. Resin component (A) containing elastomer (a2), ammonium polyphosphate flame retardant (B), metal hydrate (C) or mixture of ammonium polyphosphate flame retardant and metal hydrate (D) An optical fiber core wire or an optical fiber cord coated with a coating composition composed of, tensile properties, abrasion resistance, flexibility,
Not only does it satisfy various characteristics required for optical fiber cores or optical fiber cords such as flame resistance and cold resistance, but also when these are discarded, elution of heavy metal compounds and generation of large amounts of smoke and corrosive gas It has the excellent feature that there is no As an optical fiber core wire or cord, it has excellent heat resistance and cold resistance as compared with the one using PVC which is a conventional coating material, so it can be used in a wide temperature range, and the coating thickness is currently the same. It becomes possible to have the same mechanical properties as the conventional ones even when the thickness is made thinner and the diameter is reduced.

[Brief description of drawings]

FIG. 1 is a cross-sectional view of an embodiment of an optical fiber core wire of the present invention in which a coating layer is directly provided on the outer circumference of an optical fiber element wire.

FIG. 2 is a cross-sectional view of an example of an optical fiber cord of the present invention in which a coating layer is formed on the outer circumference of one optical fiber core wire in which a plurality of tensile strength fibers are vertically attached.

FIG. 3 is a cross-sectional view of another embodiment of the optical fiber cord of the present invention in which a plurality of tensile strength fibers are vertically attached to the outer circumferences of two optical fiber core wires, and a coating layer is further formed on the outer circumferences thereof.

[Explanation of symbols]

 1 Optical Fiber Element 2 Coating Layer 3 Optical Fiber Core 4 Tensile Fiber 5 Coating Layer 6 Coating Layer

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Claims (7)

[Claims] 1. A styrene-based thermoplastic elastomer (a2) 40-having 20% by weight or more of a polypropylene resin (a1), polystyrene as a hard segment and hydride of a butadiene and / or isoprene (co) polymer as a soft segment. 30 to 70 parts by weight of ammonium polyphosphate flame retardant (B) or 80 to 120 parts by weight of metal hydrate (C) is mixed with 100 parts by weight of resin component (A) containing 80% by weight. An optical fiber core wire or a cord, wherein a coating of the composition is formed on the outer circumference of the optical fiber core wire and / or the optical fiber core wire. 2. A styrene-based thermoplastic elastomer (a2) 40-having 20% by weight or more of a polypropylene-based resin (a1), polystyrene as a hard segment, and hydride of a butadiene and / or isoprene (co) polymer as a soft segment. Mixture (D) 30 to 120 of ammonium polyphosphate flame retardant and metal hydrate with respect to 100 parts by weight of the resin component (A) containing 80% by weight.
An optical fiber core wire or cord, characterized in that a coating of a composition containing parts by weight is formed on the outer periphery of the optical fiber core wire and / or the optical fiber core wire. 3. The polypropylene resin (a1),
The optical fiber core wire or cord according to claim 1 or 2, which is one of an ethylene / propylene random copolymer, an ethylene / propylene block copolymer, or a mixture thereof. 4. The optical fiber core wire or cord according to claim 1, 2 or 3, wherein the metal hydrate is magnesium hydroxide. 5. The optical fiber according to claim 1, wherein the resin component (A) contains an ethylene copolymer (a3) in an amount of 30% by weight or less. Core wire or cord. 6. The ethylene-based copolymer (a3) is any one of an ethylene / vinyl acetate copolymer, an ethylene / ethyl acrylate copolymer, or a mixture thereof. The optical fiber core wire or the cord according to 1. 7. The shrinkage force of the composition when the temperature is lowered from room temperature to −20 ° C. is 5 MPa or less, wherein the composition is 1, 2, 3, 4, 5 or 6. Optical fiber core or cord.