CN108020892B

CN108020892B - Heat-resistant plastic optical fiber cable

Info

Publication number: CN108020892B
Application number: CN201711057697.6A
Authority: CN
Inventors: 冲田光史
Original assignee: Asahi Kasei Corp
Current assignee: Asahi Kasei Corp
Priority date: 2016-11-02
Filing date: 2017-11-01
Publication date: 2020-07-31
Anticipated expiration: 2037-11-01
Also published as: CN108020892A; JP7320337B2; JP2022105637A; JP2018077467A

Abstract

The present invention relates to a heat-resistant plastic optical fiber cable having excellent durability in a severe environment and effectively suppressed transmission loss [ solution ] A plastic optical fiber cable (10) comprising a plastic optical fiber wire (16) and a covering layer (18), wherein the plastic optical fiber wire (16) has 1 or 2 or more cores (12) and at least 1 layer of a sheath layer (14) formed on the outer periphery of the cores, the covering layer (18) is formed on the outer periphery of the plastic optical fiber wire (16), and the plastic optical fiber cable has a shrinkage rate of 1% or less when left standing for 1 hour under a temperature condition of 105 ℃, and satisfies the standard U L VW-1.

Description

Heat-resistant plastic optical fiber cable

Technical Field

The invention relates to a heat-resistant plastic optical fiber cable.

Background

The plastic optical fiber has the following structure: the medium is a medium in which a core fiber including a transparent resin is surrounded by a sheath including a resin having a lower refractive index than the transparent resin, and light is reflected at a boundary between the core and the sheath to transmit an optical signal in the core.

Plastic optical fibers have advantages over silica glass optical fibers in that they are superior in flexibility and can be used as optical fibers having a large diameter, which are easily overlapped with each other at the time of connection.

Therefore, plastic optical fiber cables are widely used as a countermeasure against communication failure due to electromagnetic wave noise, instead of metal cables for short-distance communication within electronic devices or between devices.

Generally, a high-voltage cable is given as a source of generation of electromagnetic noise, but the environment in which the high-voltage cable is laid is often under severe environments such as high temperature (100 to 105 ℃), and therefore, plastic optical fibers are required to have durability under severe environments, that is, to have no deterioration in transmission loss and less deformation such as shrinkage due to heat.

In view of the above, plastic optical fibers having heat resistance have been proposed (see, for example, patent documents 1 and 2).

On the other hand, plastic optical fibers having a flame-retardant covering material have also been proposed (for example, see patent document 3).

Documents of the prior art

Patent document

Patent document 1: japanese laid-open patent application No. 2005-266742

Patent document 2: japanese laid-open patent application No. 2001-324626

Patent document 3: japanese patent laid-open publication No. 2016-021019

Disclosure of Invention

Problems to be solved by the invention

However, the plastic optical fibers disclosed in patent documents 1 and 2 exhibit a certain performance improvement effect with respect to transmission loss, but do not consider shrinkage due to heat, and therefore have the following problems: a cable that is contracted in consideration of use in a high-temperature environment and has a sufficient extra length in advance must be used, the degree of freedom of wiring is low, and wiring in an optical cable cannot be performed due to the design of the apparatus.

The plastic optical fiber disclosed in patent document 3 has a problem that the heat resistance is not sufficient, and is about 90 ℃.

Therefore, there is an increasing demand for plastic optical fiber cables that can be used in severe environments and have a high degree of freedom in wiring.

Accordingly, an object of the present invention is to provide: a plastic optical fiber cable which is excellent in durability in a severe environment such as a high temperature environment and effectively suppresses transmission loss.

Means for solving the problems

The present inventors have conducted extensive studies to solve the above problems of the prior art, and as a result, have found that a plastic optical fiber cable having 1 or more cores, which has a shrinkage ratio under a predetermined environment and a characteristic satisfying a predetermined standard of flame retardancy, can solve the above problems of the prior art, and have completed the present invention.

Namely, the present invention is as follows.

[1]

A plastic optical fiber cable is provided with:

a plastic optical fiber wire having 1 or 2 or more cores and at least 1 layer of sheath layer formed on the outer periphery of the cores; and the combination of (a) and (b),

a covering layer formed on the outer periphery of the plastic optical fiber,

the shrinkage rate of the plastic optical fiber cable after standing for 1 hour at the temperature of 105 ℃ is less than 1 percent,

meets the standard of U L VW-1.

[2]

The plastic optical fiber cable according to the foregoing item [1], wherein,

the cover layer contains 1 or more resins selected from the group consisting of flame-retardant polyethylene, polyvinyl chloride, polyvinylidene fluoride, tetrafluoroethylene-ethylene copolymer (ETFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), and silicone resin.

[3]

The plastic optical fiber cable according to the aforementioned item [1] or [2], wherein,

a protective layer is provided between the plastic optical fiber wire and the covering layer.

[4]

The plastic optical fiber cable according to the aforementioned item [3], wherein,

the protective layer has a tensile yield strength (JIS K7113) of 20MPa or more.

[5]

The plastic optical fiber cable according to the aforementioned item [3] or [4], wherein,

the protective layer contains 1 or more resins selected from the group consisting of polyamide resins, crosslinked polyethylene resins, and polypropylene resins.

ADVANTAGEOUS EFFECTS OF INVENTION

According to the present invention, there can be provided: a heat-resistant plastic optical fiber cable which is excellent in durability in a severe environment and effectively suppresses transmission loss.

Drawings

Fig. 1 is a schematic cross-sectional view of an example of a single-core/single-wire optical fiber cable according to the present embodiment.

Fig. 2 is a schematic cross-sectional view of another example of the single-core/single-wire optical fiber cable according to the present embodiment.

Fig. 3 is a schematic cross-sectional view of an example of the multi-core/single-wire optical fiber cable according to the present embodiment.

Fig. 4 is a schematic cross-sectional view of another example of the multi-core/single-wire optical fiber cable according to the present embodiment.

Fig. 5 is a schematic cross-sectional view of still another example of the multi-core/single-wire optical fiber cable according to the present embodiment.

Fig. 6 is a schematic cross-sectional view of an example of the single-fiber and two-fiber optical cable according to the present embodiment.

Description of the reference numerals

10. 20, 30, 40, 50, 60 … plastic optical fiber cable

12. 22, 32, 42, 52, 62a, 62b … core

14. 24, 34, 44, 54, 64a, 64b … sheath

441 st sheath layer (441 st 441 …)

442 … sheath 2

16. 26, 36, 46, 56, 66a, 66b … plastic optical fiber wire

18. 29, 38, 48, 59, 68 … cover layer

28. 58 … protective layer

Detailed Description

Hereinafter, a mode for carrying out the present invention (hereinafter, simply referred to as "the present embodiment") will be described in detail.

The following embodiments are examples for illustrating the present invention, and the present invention is not intended to be limited to the following. The present invention can be suitably modified and implemented within the scope of the gist thereof.

[ Plastic fiber Cable ]

The plastic optical fiber cable of the present embodiment is a plastic optical fiber cable,

it is provided with: a plastic optical fiber wire having 1 or 2 or more cores and a sheath layer formed on the outer periphery of the cores and composed of at least 1 layer; and the combination of (a) and (b),

a covering layer formed on the outer periphery of the plastic optical fiber,

meets the standard of U L VW-1.

The "covering layer formed on the outer periphery of the plastic optical fiber wire" is not limited to the case where the outer peripheral surface of the plastic optical fiber wire is in contact with the covering layer, and includes: in the case where another resin layer is interposed between the covering layer and the optical fiber wire.

The plastic optical fiber cable of the present embodiment has the above-described limited thermal shrinkage rate and the above-described limited flame retardancy, and thus is excellent in reduction of transmission loss. The reason for this is estimated as follows.

That is, it is considered that the magnitude of the thermal shrinkage rate is released when a certain amount of heat is applied, and affects the residual stress in the optical fiber cable. In general, when a plastic optical fiber cable is laid, it is common practice to bend the cable at a plurality of positions, and the plastic optical fiber cable is evaluated in a bent state also in the evaluation of heat resistance, but when a resin having a large heat shrinkage rate and being strong is heated in a bent state, strong stress is generated in the plastic optical fiber wire inside due to the heating and deformation, and it is considered that some damage is caused to the wire in the same manner as in the periphery of the connector mounting portion.

In view of this, in the plastic optical fiber cable of the present embodiment, the shrinkage rate after standing for 1 hour under a temperature condition of 105 ℃ is limited to 1% or less, and the reduction of the transmission loss is surely prevented.

In addition, the magnitude of flame retardancy is believed to have an effect on the degree of oxidative degradation of a substance. It is estimated that in the plastic optical fiber cable according to the present embodiment, by appropriately adjusting the degree of residual stress and oxidative degradation released when heat is applied, physical and chemical loads applied to the plastic optical fiber cable can be suppressed, and physical and chemical signal interference causing transmission loss can be reduced.

In view of this, the plastic optical fiber cable according to the present embodiment is limited to satisfy the standard U L VW-1, and the reduction of the transmission loss is surely prevented.

Generally, it is presumed that a resin having high flame retardancy has high heat resistance, and when it has flame retardancy conforming to the standard U L VW-1, it is considered advantageous to improve the heat resistance of the plastic optical fiber cable.

Therefore, the covering material used for the covering layer constituting the plastic optical fiber cable of the present embodiment must meet the standard U L VW-1.

Fig. 1 is a schematic cross-sectional view of a single-core, single-wire plastic optical fiber cable, which is an example of the plastic optical fiber cable according to the present embodiment.

The plastic optical fiber cable 10 is a single-wire single-core optical fiber cable having 1 wire.

The plastic optical fiber cable 10 includes: the core 12 is provided inside, and the sheath layer 14 formed on the outer periphery of the core 12 is covered, and the cover layer 18 formed on the outer periphery of the sheath layer 14 is covered.

In the above case, the plastic optical fiber 16 including the core 12 and the sheath 14 is referred to as a plastic optical fiber.

Further, a predetermined outer cover layer (not shown) may be further provided on the outer periphery of the cover layer 18. This makes it possible to protect the plastic optical fiber 16 more reliably from long-term use outdoors, chemicals coming into contact with the plastic optical fiber, and the like.

Fig. 2 is a schematic cross-sectional view of another example of the plastic optical fiber cable according to the present embodiment, which is another embodiment of a single-core, single-wire plastic optical fiber cable.

As shown in fig. 2, the plastic optical fiber cable 20 of the present embodiment may include a protective layer between the sheath layer and the covering layer.

The plastic optical fiber cable 20 includes: a sheath 24 having a core 22 at the center and covering the outer periphery of the core 22, a protective layer 28 covering the outer periphery of the sheath 24, and a cover layer 29 covering the outer periphery of the protective layer 28.

In the above case, the plastic optical fiber wire 26 including the core 22 and the sheath 24 is referred to as a "plastic optical fiber.

By further forming the protective layer 28 on the outer periphery of the sheath 24 of the plastic optical fiber wire 26, the plastic optical fiber wire 26 can be more reliably protected from long-term use in the field, chemicals and the like coming into contact with the plastic optical fiber wire.

Fig. 3 is a schematic cross-sectional view of another example of the plastic optical fiber cable according to the present embodiment, which is one embodiment of a multi-core, single-wire plastic optical fiber cable.

As shown in fig. 3, the plastic optical fiber cable of the present embodiment may be a multi-core optical fiber cable having a plurality of cores.

The plastic optical fiber cable 30 is a 7-core type optical fiber cable.

The plastic optical fiber cable 30 is multi-cored by covering 7 cores 32 with a sheath 34. A covering layer 38 is formed on the outer periphery of the sheath layer 34.

In the above case, the plastic optical fiber wire 36 including the core 32 and the sheath 34 is referred to as "plastic optical fiber wire".

Further, an outer cover layer (not shown) may be further provided on the outer periphery of the cover layer 38. This makes it possible to protect the plastic optical fiber 36 more reliably from long-term use outdoors, chemicals coming into contact with the plastic optical fiber, and the like.

Fig. 4 is a schematic cross-sectional view of another embodiment of the plastic optical fiber cable according to the present embodiment, which is another embodiment of a multi-core, single-wire plastic optical fiber cable.

As shown in fig. 4, each core 42 of the plastic optical fiber cable of the present embodiment may be covered with a first sheath 441, respectively.

The plastic optical fiber cable 40 is multi-stranded by covering the cores 42 with the first sheath 441 and covering them with the second sheath 442.

A covering layer 48 is formed on the outer periphery of the second sheath layer 442.

The inclusion of the first and

second sheaths

441 and 442 is referred to as the sheath 44, and the inclusion of the core 42 and sheath 44 is referred to as the plastic optical fiber wire 46.

Fig. 5 is a schematic cross-sectional view of another embodiment of the plastic optical fiber cable according to the present embodiment, which is another embodiment of a multi-core, single-wire plastic optical fiber cable.

As shown in fig. 5, the plastic optical fiber cable according to the present embodiment may be a multi-core optical fiber cable having a protective layer between a plastic optical fiber wire and a covering layer.

The plastic optical fiber cable 50 is multi-stranded by covering the cores 52 with the sheaths 54, and covering 7 cores 52 covered with the sheaths 54 with the protective layer 58. Including the core 52 and the sheath 54 is referred to as a plastic optical fiber wire 56, and the outer periphery of the plastic optical fiber wire 56 is covered with a protective layer 58. Further, a covering layer 59 is formed on the outer periphery of the protective layer 58.

Fig. 6 is a schematic cross-sectional view of another example of the plastic optical fiber cable according to the present embodiment, which is a single-core, double-wire plastic optical fiber cable.

The plastic optical fiber cable 60 is a single-core, double-wire plastic optical fiber cable having 2

cores

62a, 62 b.

The plastic optical fiber cable 60 has

cores

62a and 62b inside,

sheaths

64a and 64b formed on the outer peripheries of the

cores

62a and 62b, and a covering 68 formed on the outer peripheries of the

sheaths

64a and 64 b.

In the above case, the core 62a and the sheath 64a are referred to as a plastic optical fiber wire 66a, and the core 62b and the sheath 64b are referred to as a plastic optical fiber wire 66 b.

A predetermined outer cover layer (not shown) may be provided on the outer periphery of the cover layer 68. This makes it possible to protect the plastic

optical fiber wires

66a and 66b more reliably from long-term use outdoors, chemicals coming into contact with the wires, and the like.

(core)

The resin constituting the core (hereinafter, also referred to as "core resin") is preferably a transparent resin.

As the core resin, those known as core resins of plastic optical fibers can be used, and examples thereof include, but are not limited to, polymethyl methacrylate resins and polycarbonate resins. Among them, polymethyl methacrylate resins are preferred from the viewpoint of transparency.

The polymethyl methacrylate resin is a homopolymer of methyl methacrylate or a copolymer containing 50 mass% or more of a methyl methacrylate component. The polymethyl methacrylate resin may be a copolymer containing methyl methacrylate and a component copolymerizable with methyl methacrylate.

The component copolymerizable with methyl methacrylate is not particularly limited, and examples thereof include acrylic esters such as methyl acrylate, ethyl acrylate, and butyl acrylate; methacrylates such as methyl methacrylate, ethyl methacrylate, propyl methacrylate, and cyclohexyl methacrylate; maleimides such as isopropylmaleimide; acrylic acid, methacrylic acid, styrene, and the like. These may be used alone in 1 kind, or may be used in combination of 2 or more kinds.

The molecular weight of the polymethyl methacrylate resin is preferably 8 to 20 ten thousand, more preferably 10 to 12 ten thousand, in terms of weight-average molecular weight, from the viewpoint of melt flow (ease of molding).

The number of cores of the wires constituting the plastic optical fiber cable according to the present embodiment is preferably 1 in the case of a single core and 7 or more in the case of a multi-core.

The maximum number of cores in the cross section in the case of a multi-core is preferably 10000 or less, more preferably 19 to 1000, from the viewpoint of ease of production.

The cross-sectional diameter of the core of the plastic optical fiber wire is preferably 100 to 3000 μm, more preferably 250 to 2000 μm, and still more preferably 500 to 1500 μm in the case of a single core. The light quantity passing through the core can be further increased if the cross-sectional diameter of the core is 100 μm or more, and the light quantity can be further increased if the cross-sectional diameter is 250 μm or more. Further, the core can be flexibly bent if the cross-sectional diameter is 3000 μm or less, and can be further flexibly bent if the cross-sectional diameter is 2000 μm or less.

In the case of a multi-core, the cross-sectional diameter of each core is preferably 5 to 500. mu.m, more preferably 60 to 200. mu.m. When the cross-sectional diameter of the core is 5 μm or more, the amount of light passing therethrough can be further increased. Further, if the diameter of the core is 500 μm or less, the decrease in the amount of transmitted light due to warping can be further reduced.

(sheath layer)

The sheath layer is a layer covering the outer periphery of the core.

By providing the sheath, the plastic optical fiber cable can propagate an optical signal even if the cable is bent, by utilizing reflection at the interface between the sheath and the core.

In this case, if the refractive index of the second sheath layer located outside the first sheath layer located inside is lowered, part of the light transmitted through the first sheath layer can be collected by the interface reflection of the first sheath layer and the second sheath layer, which is preferable.

The resin constituting the sheath layer (hereinafter also referred to as "sheath resin") is not particularly limited as long as it has a refractive index smaller than that of the resin constituting the core, and a known resin can be used.

A preferable example of the plastic optical fiber cable according to the present embodiment is a plastic optical fiber cable in which the plastic optical fiber wire is composed of a core made of the transparent resin and at least 1-layer sheath layer formed on the outer periphery of the core and covered with a resin having a lower refractive index than the transparent resin, for example, a fluororesin.

The refractive index of the resin constituting the core is more preferably 0.01 to 0.15 higher than the refractive index of the resin constituting the sheath.

As the difference in refractive index between the resin constituting the core and the resin constituting the sheath is smaller, signals up to high frequencies can be propagated, but the cable tends to be fragile to bending.

On the other hand, the larger the difference in refractive index between the resin constituting the core and the resin constituting the sheath, the more the bending of the cable can be enhanced, but light of a high frequency tends to be less likely to pass therethrough.

From the above viewpoint, it is preferable that the difference in refractive index between the resin constituting the core and the resin constituting the sheath is within the above numerical range.

The resin constituting the sheath layer is not limited to the following, and examples thereof include a fluororesin and the like. Among them, a fluororesin having high transmittance to light to be used is preferable.

By using a fluororesin as the resin constituting the sheath layer, transmission loss can be further suppressed.

The fluororesin is not limited to the following, and examples thereof include a fluoromethyl methacrylate polymer, a polyvinylidene fluoride resin, and the like.

The fluoro methacrylate-based polymer is not limited to the following, but is preferably a polymer of a fluorine-containing acrylate monomer or a methacrylate monomer, such as fluoroalkyl methacrylate, fluoroalkyl acrylate, α -fluoro-fluoroalkyl acrylate, from the viewpoint of high transmittance, heat resistance, and excellent moldability.

The copolymer may contain a fluorine-containing (meth) acrylate monomer and another component copolymerizable therewith, and is preferably a copolymer of a fluorine-containing (meth) acrylate monomer and a copolymerizable hydrocarbon monomer such as methyl methacrylate. It is preferable to form a copolymer of a (meth) acrylate monomer containing fluorine and a hydrocarbon monomer copolymerizable therewith because the refractive index can be controlled.

On the other hand, the polyvinylidene fluoride resin is not limited to the following, and for example, a homopolymer of vinylidene fluoride is preferable from the viewpoint of excellent heat resistance and moldability; a copolymer of vinylidene fluoride and at least 1 or more monomer selected from the group consisting of tetrafluoroethylene, hexafluoropropylene, trifluoroethylene, hexafluoroacetone, perfluoroalkyl vinyl ether, chlorotrifluoroethylene, ethylene, and propylene; an alloy of a polymer containing these vinylidene fluoride components and a PMMA resin.

(protective layer)

The plastic optical fiber cable according to the present embodiment may include a predetermined protective layer between the plastic optical fiber wire and a coating layer described later.

That is, the protective layer may cover the outer circumference of the sheath layer formed on the 1 plastic optical fiber wire, and the protective layer may be further covered by the covering layer. In this embodiment, when the protective layer is used without being further covered with a cover layer, the cover layer is not a protective layer.

The protective layer may be a layer containing a resin that is in contact with the outside of the sheath layer, and that can impart functions such as mechanical properties, heat resistance, and light shielding properties to the plastic optical fiber cable as needed.

In the present embodiment, when the refractive index is higher than that of the inner sheath layer or the opaque or colored layer (that is, the layer does not have transparency to the extent that it can reflect the target light), the layer is a protective layer and is not the outer sheath layer. The thickness of the protective layer is not limited, and if it is 300 μm or less, the flexibility of the plastic optical fiber cable can be maintained, preferably, if it is 250 μm or less, the flexibility can be further maintained, preferably.

The material of the protective layer is not limited to the following, and examples thereof include polyamide resin, polyethylene resin, polypropylene resin, polyvinylidene fluoride resin, and the like. The refractive index used was a value measured at 20 ℃ by sodium D-ray.

The protective layer is preferably disposed so as to surround the sheath layer. In particular, the protective layer can protect the plastic optical fiber cable from external force such as lateral pressure, and can also have an effect of alleviating external impact. It is preferable to have sufficient strength for protecting it from external force, and particularly tensile yield strength (JIS K7113) is preferably 20MPa or more, more preferably 25MPa or more, and further preferably 30MPa or more.

Examples of the resin having such strength include polyamide resins, particularly polyamide 12 resins, crosslinked polyethylene resins, and polypropylene resins.

(cover layer)

In the plastic optical fiber cable according to the present embodiment, the covering layer is a layer covering the outer periphery of the optical fiber wire, and does not mean a protective layer.

The covering layer contains a resin composition conforming to the U L VW-1 standard, and when such a resin composition is used for the covering layer, a plastic optical fiber with less deterioration of transmission loss in a high-temperature environment is obtained.

In order to prevent deterioration of transmission loss in a high-temperature environment, it is useful to comply with the U L VW-1 standard, as estimated as follows.

That is, it is generally estimated that a resin having high flame retardancy has high heat resistance, and it is considered that the resin having flame retardancy meeting this standard is advantageous for improving the heat resistance of the plastic optical fiber cable.

Therefore, the resin material constituting the covering layer used for the plastic optical fiber cable of the present embodiment must meet the standard U L VW-1.

The resin used for the cover layer is not particularly limited as long as the above properties are satisfied, and examples thereof include flame-retardant polyethylene resins, polyvinyl chloride, polyvinylidene fluoride, tetrafluoroethylene-ethylene copolymer (ETFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), and the like; a silicone resin. From the viewpoint of environmental concerns, it is particularly preferable that the flame-retardant polyethylene resin composition to which flame retardancy is imparted by blending a flame-retardant material with a polyethylene resin does not contain halogen.

The flame-retardant polyethylene resin composition is not limited to the following, and preferably contains, for example, (a) at least 1 or more copolymer selected from the group consisting of an ethylene- α -olefin copolymer, an ethylene-vinyl acetate copolymer, and an ethylene-ethyl acrylate copolymer, (B) high-density polyethylene modified with an unsaturated carboxylic acid or a derivative thereof, (C) magnesium hydroxide, and (D) red phosphorus.

Further, from the viewpoint of further improving flame retardancy, it is more preferable to contain (E) melamine isocyanurate.

The content of the component (a) in the flame-retardant polyethylene resin composition is not particularly limited as long as the flame retardancy can be maintained, and is preferably 10 to 50% by mass, more preferably 20 to 50% by mass, and still more preferably 30 to 50% by mass.

By setting the content of the component (a) within the above range, the plastic optical fiber cable of the present embodiment can maintain practically sufficient flame retardancy, and further can suppress the occurrence of peeling and twisting during the covering of the plastic optical fiber wire.

The component (A) is preferably at least one selected from the group consisting of (A-1) an ethylene- α -olefin copolymer, (A-2) an ethylene-vinyl acetate copolymer, and (A-3) an ethylene-ethyl acrylate copolymer, and among these, a combination of (A-1) an ethylene- α -olefin copolymer, and (A-2) an ethylene-vinyl acetate copolymer and/or (A-3) an ethylene-ethyl acrylate copolymer is more preferred.

The components are described in detail below.

< (A-1) ethylene- α -olefin copolymer

The ethylene- α -olefin copolymer is not limited to the following, and examples thereof include a copolymer of ethylene and α -olefin having 3 to 12 carbon atoms.

Examples of the α -olefin include propylene, 1-butene, 1-hexene, 4-methyl-1-pentene, 1-octene, 1-decene, and 1-dodecene.

The ethylene- α -olefin copolymer is not limited to the following, and examples thereof include an ethylene-1-butene copolymer, an ethylene-1-hexene copolymer, and an ethylene-1-octene copolymer.

These may be used alone or in combination of 2 or more.

The melt flow rate (MFR; measured in accordance with JIS K7210 (load: 2.16 kg)) of the ethylene- α -olefin copolymer is preferably 0.1 to 50g/10 min, more preferably 0.5 to 10g/10 min, from the viewpoint of improving the processability, flame retardancy, heat resistance, etc. of the resulting resin composition in a well-balanced manner.

The density of the ethylene- α -olefin copolymer (measured according to JIS K7112) is preferably 0.91 to 0.96g/cm³More preferably 0.92 to 0.95g/cm³。

Commercially available ethylene- α -olefin copolymers may be used, and examples of the commercially available products include trade names "NEO-ZEX", "Ult-Zex", "Moretec", "Evolue" (manufactured by Prime Polymer Co., L td), trade names "Novatec", "Harmorex", and the like (manufactured by Nippon polyethylene Co., Ltd.).

The content of the component (A-1) in the flame-retardant polyethylene resin composition is not particularly limited, but is preferably 0 to 50% by mass, more preferably 5 to 45% by mass, and still more preferably 10 to 20% by mass. When the content of the component (A-1) is 5% by mass or more, the processability of the coating layer when the plastic optical fiber wire is coated is excellent. Flame retardancy is further improved by setting the content of the component (A-1) to 50% by mass or less.

< (A-2) ethylene-vinyl acetate copolymer

The ethylene-vinyl acetate copolymer used is preferably an ethylene-vinyl acetate copolymer having a melt flow rate (MFR: measured in accordance with JIS K7210 (load: 2.16 kg)) of 0.1 to 50g/10 min, more preferably 0.5 to 10g/10 min, in order to further improve the physical properties, processability and flame retardancy of the resulting resin composition.

The content of the vinyl acetate monomer in the ethylene-vinyl acetate copolymer is preferably 5 to 45 mass%, more preferably 10 to 35 mass%.

Commercially available ethylene-vinyl acetate copolymers may be used, and examples of the commercially available ethylene-vinyl acetate copolymers include those having a trade name of "EVAF L EX" (manufactured by Dupont-Mitsui Polychemical Co., L td), and those having a trade name of "ME L THENE" (manufactured by Tosoh Corp.).

< (A-3) ethylene-ethyl acrylate copolymer

The melt flow rate (measured in accordance with JIS K7210 (load: 2.16 kg)) of the ethylene-vinyl acetate copolymer used as the ethylene-ethyl acrylate copolymer is preferably 0.1 to 50g/10 min, more preferably 0.5 to 20g/10 min, in order to further improve the physical properties, processability and flame retardancy of the resulting resin composition.

The content of the ethyl acrylate monomer in the ethylene-ethyl acrylate copolymer is preferably 5 to 45 mass%, more preferably 10 to 35 mass%.

Examples of the commercially available product include a product name "Rexpearl" (manufactured by japan polyethylene corporation), a product name "Elvaloy" (manufactured by Dupont-Mitsui polychemicalco., &lttt translation = L "&gttl &ttt/t &gtttd), and the like.

The flame-retardant polyethylene resin composition constituting the covering layer contains the above-mentioned component (A), component (B), component (C), component (D) and the like, and preferably contains, as the component (A), an ethylene- α -olefin copolymer (A-1), an ethylene-vinyl acetate copolymer (A-2) and/or an ethylene-ethyl acrylate copolymer (A-3), and the total content of the component (A-1) in the component (A) is 5 to 40% by mass and the total content of the component (A-2) and/or the component (A-3) in the component (A) is 5 to 45% by mass.

When the components (A) to (D) are used in combination, the content of the components (A-2) and (A-3) is set to the above ratio, whereby the adhesion between the plastic optical fiber wire and the covering layer can be further improved while maintaining the practically required flame retardancy. As a result, the flame retardant composition has excellent flame retardancy, and further, the piston (Japanese: ピストニング) characteristics tend to be improved, and therefore, the flame retardant composition is more preferable.

The content of the component (A-2) and the component (A-3) in the flame-retardant polyethylene resin composition is not particularly limited, and the total content of the component (A-2) and the component (A-3) is preferably 5 to 45% by mass, more preferably 10 to 40% by mass.

When the total content of the component (A-2) and the component (A-3) is 5% by mass or more, the filling property of the resulting resin composition into other compounds is further improved. When the total content of the components (A-2) and (A-3) is 45% by mass or less, the heat resistance of the resulting plastic optical fiber is further improved.

< (B) high-density polyethylene modified with unsaturated carboxylic acid or derivative thereof

The high-density polyethylene modified with an unsaturated carboxylic acid or a derivative thereof (hereinafter, sometimes referred to as acid-modified high-density polyethylene) is obtained by modifying a high-density polyethylene with an unsaturated carboxylic acid or a derivative thereof (hereinafter, sometimes referred to as acid modification).

The density of the high-density polyethylene before acid modification is 0.935-0.975 g/cm³The polyethylene of (1).

Generally, the density of high density polyethylene is substantially unchanged by acid modification. Therefore, the density of the acid-modified high-density polyethylene is preferably 0.935 to 0.975g/cm³。

The unsaturated carboxylic acid used for the acid modification is not limited to the following, and examples thereof include unsaturated carboxylic acids such as fumaric acid, acrylic acid, maleic acid, itaconic acid, methacrylic acid, sorbic acid, crotonic acid, citraconic acid, 5-norbornene-2, 3-dicarboxylic acid, 4-methylcyclohexene-1, 2-dicarboxylic acid, and 4-cyclohexene-1, 2-dicarboxylic acid, and anhydrides thereof (for example, maleic anhydride, itaconic anhydride, citraconic anhydride, 5-norbornene-2, 3-dicarboxylic anhydride, 4-methylcyclohexene-1, 2-dicarboxylic anhydride, and 4-cyclohexene-1, 2-dicarboxylic anhydride). Among them, maleic anhydride is preferable.

The amount of the unsaturated carboxylic acid or derivative thereof used for acid modification is preferably 0.05 to 10% by mass based on the high-density polyethylene before modification.

The modification method is not particularly limited, and a known method may be used. Examples of the modification method include a solution method, a suspension method, and a melting method.

In the case of the solution method, for example, the following methods can be mentioned: adding high-density polyethylene and unsaturated carboxylic acid or derivatives thereof into a non-polar organic solvent, further adding a free radical initiator, and heating to a high temperature of 100-160 ℃. Thus, an acid-modified high-density polyethylene can be obtained. Examples of the nonpolar solvent include hexane, heptane, benzene, toluene, xylene, chlorobenzene, tetrachloroethane, and the like. Examples of the radical initiator include organic peroxides such as 2, 5-dimethyl-2, 5-di (t-butylperoxy) hexane, 2, 5-dimethyl-2, 5-di (t-butylperoxy) -3-hexyne, and benzoyl peroxide.

In the case of the suspension method, for example, the following methods can be mentioned: high-density polyethylene and an unsaturated carboxylic acid or its derivative are put into a polar solvent such as water, and a radical initiator is further added thereto, and the mixture is heated under high pressure to a high temperature of 100 ℃ or higher. Thus, an acid-modified high-density polyethylene can be obtained. As the radical initiator, those mentioned above can be suitably used as specific examples.

In the case of the melting method, for example, the following methods can be mentioned: the high-density polyethylene, the unsaturated carboxylic acid or its derivative, and the radical initiator are melt-kneaded using a melt-kneading machine (for example, an extruder, a banbury mixer, a kneader, or the like) which can be used in the field of synthetic resins. Thus, an acid-modified high-density polyethylene can be obtained.

In order to sufficiently satisfy the physical properties and processability of the resin composition obtained, the melt flow rate (MFR: measured in accordance with JIS K7210 (load: 2.16 kg)) of the high-density polyethylene before modification is preferably 0.1 to 50g/10 min, more preferably 0.5 to 10g/10 min.

Commercially available products can be used as the high-density polyethylene for obtaining the acid-modified high-density polyethylene, and commercially available products can be used as the commercially available products, for example, a product name "Novatec" (manufactured by Nippon polyethylene Co., Ltd.), a product name "SANTAC" (manufactured by Asahi Kasei corporation), and commercially available products can be used as the acid-modified high-density polyethylene.

In the present embodiment, the acid-modified high-density polyethylene as the component (B) may be used alone in 1 kind or in combination of 2 or more kinds.

The ratio of the component (B) in the flame-retardant polyethylene resin composition constituting the covering layer is not particularly limited, but is preferably 1 to 15% by mass, more preferably 5 to 10% by mass. When the content of the component (B) in the flame-retardant polyethylene resin composition constituting the covering layer is 1 mass% or more, the heat resistance of the plastic optical fiber cable of the present embodiment is further improved. When the content of the component (B) in the flame-retardant polyethylene resin composition constituting the covering layer is 15% by mass or less, the piston characteristics are further improved.

Magnesium hydroxide (C)

The magnesium hydroxide is not limited to the following, and examples thereof include synthetic magnesium hydroxide produced from seawater and the like, and natural ore-derived substances mainly containing magnesium hydroxide produced by pulverizing natural brucite ore.

The average particle diameter of the component (C) is preferably 40 μm or less, more preferably 0.2 to 6 μm, from the viewpoint of dispersibility and flame retardancy effects. The average particle diameter can be measured by a laser diffraction particle size distribution measuring apparatus.

When the flame-retardant polyethylene resin composition contains at least the component (A), the component (B), the component (C) and the component (D), the component (C) is preferably magnesium hydroxide surface-treated with a predetermined surface-treating agent. This can further improve the kneading property with a nonpolar resin derived from an ethylene structure or the like.

The surface-treating agent is not limited to the following, and examples thereof include fatty acids (e.g., higher fatty acids such as stearic acid, oleic acid, palmitic acid, linoleic acid, lauric acid, capric acid, behenic acid, montanic acid), fatty acid metal salts (e.g., sodium salt, potassium salt, aluminum salt, calcium salt, magnesium salt, zinc salt, barium salt, cobalt salt, tin salt, titanium salt, iron salt, etc. of the above-mentioned fatty acids), fatty acid amides (e.g., amides of the above-mentioned fatty acids), titanate coupling agents (e.g., isopropyl-tris (dioctyl phosphate) titanate, titanium (octyl phosphate) oxyacetate, etc.), silane coupling agents (e.g., vinyltriethoxysilane, vinyltris (β -methoxyethoxy) silane, methacryloxypropyltrimethoxysilane, methacryloxypropyltriethoxysilane, methacryloxypropylmethyldimethoxysilane, etc.), among which preferable surface-treating agents are stearic acid, calcium stearate, methacryloxypropyltrimethoxysilane, etc.

The amount of the surface treatment agent to be treated with the magnesium hydroxide is not particularly limited, but is preferably 0.5 to 5.0% by mass, more preferably 1.0 to 4.0% by mass, and still more preferably 1.5 to 3.5% by mass.

When the treatment amount of the surface treatment agent is 0.5% by mass or more, the entire surface of magnesium hydroxide can be effectively covered and the effect as a compatibilizing agent is further improved. On the other hand, when the surface treatment amount is 5.0 mass% or less, an economically excellent treatment effect can be obtained.

As the magnesium hydroxide subjected to surface treatment, commercially available ones can also be used. Examples of the commercially available product include a trade name "KISUMA" (manufactured by kyo chemical industries), a trade name "マグシーズ" (manufactured by sheniso chemical industries). The magnesium hydroxide may be used alone or in combination of 2 or more.

The content of the magnesium hydroxide (C) in the flame-retardant polyethylene resin composition constituting the covering layer is not particularly limited as long as the flame retardancy of the covering layer is maintained, and is preferably 30 to 60 mass%, more preferably 30 to 50 mass%, further preferably 30 to 40 mass%, and further more preferably 30 to 35 mass%.

When the content of magnesium hydroxide is 30% by mass or more, the flame retardancy of the flame retardant polyethylene resin composition obtained is further improved. (C) When the content of magnesium hydroxide is 60% by mass or less, the resultant flame-retardant polyethylene resin composition can be prevented from becoming brittle, and the processability, flexibility, and the like can be further improved.

Red phosphorus

Red phosphorus can function as a flame retardant aid or the like.

Red phosphorus is a relatively unstable compound, is liable to ignite, is particularly liable to cause dust explosion, and is liable to deteriorate a resin with time, and therefore, it is preferable to use red phosphorus in which the surface of red phosphorus particles is covered with a stabilizer.

The stabilizer is not limited to the following, and examples thereof include metals, metal oxides, thermosetting resins, and the like.

Examples of the metal include aluminum, iron, chromium, nickel, zinc, manganese, antimony, zirconium, titanium, and the like.

Examples of the metal oxide include zinc oxide, aluminum oxide, and titanium oxide.

Examples of the thermosetting resin include phenol resin, epoxy resin, melamine resin, urea resin, polyester resin, silicone resin, polyamide resin, and acrylic resin.

The stabilizer may be used alone in 1 kind or in combination of 2 or more kinds.

The surface coverage of the stabilizer is preferably 0.5 to 15% by mass in terms of metal, metal oxide, and the thermosetting resin is preferably 5 to 30% by mass in terms of solid content, with respect to the red phosphorus particles.

The average particle diameter of red phosphorus is preferably 50 μm or less, more preferably 1 to 40 μm, from the viewpoint of dispersibility in a resin and an effect as a flame retardant aid. The average particle diameter of red phosphorus can be measured by a laser diffraction particle size distribution measuring apparatus.

The commercially available product may be, for example, the trade name "RINKA _ FE" (manufactured by RINKAGAKU KOGYO Co., Ltd., L td.) or the trade name "HISHIGUARD" (manufactured by Nippon chemical industry Co., Ltd.).

The content of red phosphorus (D) in the polyethylene resin composition of the present embodiment is not particularly limited as long as flame retardancy can be maintained, and is preferably 0.1 to 10% by mass, more preferably 1 to 5% by mass.

When the content of red phosphorus is 0.1 mass% or more, the flame retardancy is further improved. When the content of red phosphorus is 10% by mass or less, the processability and the like of the flame-retardant polyethylene resin composition obtained are further improved.

< (E) Melamine isocyanurate

In order to further improve the flame retardancy of the plastic optical fiber cable, the flame retardant polyethylene resin composition preferably further contains (E) melamine cyanurate.

The flame retardancy can be further improved by using the component (B), the component (C), the component (D) and the like in combination.

The content of the component (E) in the flame-retardant polyethylene resin composition is preferably 1 to 5% by mass.

The melamine cyanurate may be a commercially available product. Examples of commercially available products include those available from Sakai chemical industry Co., Ltd.

When the flame-retardant polyethylene resin composition contains the component (a), the component (B), the component (C) and the component (D), the flame-retardant polyethylene resin composition preferably contains the component (a) in an amount of 10 to 50% by mass, the component (B) in an amount of 1 to 15% by mass, the component (C) in an amount of 30 to 60% by mass and the component (D) in an amount of 0.1 to 10% by mass. When the flame-retardant polyethylene resin composition further contains component (E), the content of component (E) in the flame-retardant polyethylene resin composition is preferably 1 to 5% by mass. The flame-retardant polyethylene resin composition having the above-described composition has more excellent flame retardancy, and the various effects of the present embodiment are further improved.

< (F) other component

Each portion constituting the plastic optical fiber cable of the present embodiment may further contain other additives than the above-described additives within a range not to impair the effects of the present embodiment.

The additives may be selected according to the purpose of use, and examples thereof include, but are not limited to, colorants such as carbon black, antioxidants, ultraviolet absorbers, light stabilizers, metal deactivators, lubricants, flame retardants other than those described above, flame retardant aids, and fillers.

(other constitution)

As described above, the plastic optical fiber cable according to the present embodiment includes: a plastic optical fiber wire having 1 or 2 or more cores and a sheath layer formed on the outer periphery of the cores and composed of at least 1 layer; and a covering layer formed on the outer circumference of the plastic optical fiber wire.

The plastic optical fiber cable of the present embodiment may further include an outer cover layer described later, and the number of wires may be appropriately selected.

< outer cover layer >

The plastic optical fiber cable of the present embodiment may be used with the above-described covering layer as the outermost layer, or may be used as a further reinforced optical fiber cable whose outer periphery is further coated with an outer covering layer (also referred to as "jacket") made of thermoplastic resin such as nylon 12, soft nylon, polyethylene, polyvinyl chloride, polypropylene, fluorine resin, or the like.

The optical fiber cable according to the present embodiment, and materials other than the optical fiber cable according to the present embodiment, such as a metal cable and a reinforcing material, may be covered with an outer covering layer to form a composite cable.

< number of lines >

The plastic optical fiber cable of the present embodiment is not limited to a single-wire cable, and may be a double-wire cable or more.

The method of forming a double wire cable is not particularly limited, and a method of simultaneously extruding and covering double wires, a method of bonding single wires 2 with another resin, an adhesive, or the like, and the like may be mentioned.

(Properties of Plastic optical fiber Cable)

< Heat shrinkage >

In general, a plastic optical fiber is stretched in manufacturing, and therefore, shrinkage is often caused in a high-temperature environment. Therefore, when such shrinkage occurs after the plastic optical fiber cable is laid, the cable may be broken.

Therefore, the plastic optical fiber cable of the present embodiment has a shrinkage rate (thermal shrinkage rate) of 1% or less, preferably 0.5% or less, and more preferably 0.3% or less, when left to stand at 105 ℃ for 1 hour.

The thermal shrinkage varies depending on the method of manufacturing the plastic optical fiber wire, the protective layer, and the coating layer, and therefore, these are not particularly limited, but must be measured after manufacturing the plastic optical fiber cable.

The thermal shrinkage rate can be controlled to 1% or less by, for example, allowing the plastic optical fiber cable to stand (aging) at a high temperature of 100 ℃ or higher for a certain period of time, or allowing the plastic optical fiber wire to stand at a high temperature of 100 ℃ or higher for a certain period of time and then covering the plastic optical fiber wire. When a plastic optical fiber cable is manufactured by covering a plastic optical fiber wire material having a heat shrinkage rate of 1% or less under the above-mentioned conditions, it is not necessary to cure the plastic optical fiber cable, or even if necessary, the heat shrinkage rate under the above-mentioned conditions can be reduced to 1% or less by curing in a short time, and therefore, this is particularly preferable.

The plastic optical fiber cable of the present embodiment has characteristics satisfying the standard U L VW-1.

The "U L VW-1 standard" is a combustion test, and specifically, it is a test mode in which a test specimen is held vertically, brought into contact with a flame of a burner at an angle of 20 degrees, ignited for 15 seconds, and stopped for 15 seconds, and repeated 5 times to examine the degree of combustion of the test specimen.

In order to comply with the "U L VW-1 standard", the plastic optical fiber cable of the present embodiment is effectively provided with a flame-retardant covering material as described above.

[ method for manufacturing Plastic optical fiber Cable ]

The method for manufacturing the plastic optical fiber cable according to the present embodiment is not particularly limited, and can be performed by a known method.

For example, the following method can be preferably used: a method of forming a coating layer comprising the polyethylene resin, polyvinyl chloride, polyvinylidene fluoride, tetrafluoroethylene-ethylene copolymer (ETFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), and silicone resin, which are thermally fused by a cross-head die, on the outer side of a plastic optical fiber strand produced by a known composite spinning method.

[ examples ]

The present embodiment will be described in detail below with reference to specific examples and comparative examples, but the present embodiment is not limited to the following examples.

The physical property values used in the present specification and the evaluation physical property values evaluated in [ example ] and [ comparative example ] described later are measured by the following measurement methods and evaluation methods, respectively.

((1) Heat resistance)

A connector HFBR-4503Z manufactured by Broadcom corporation was attached to both ends of a 10m plastic optical fiber cable by the method described in the data sheet of the connector.

The plastic optical fiber cable with the connector mounted thereon was wound around a tube of phi 306mm, and the amount of light was measured as an "initial value" using an optical power meter photosom 205A made by Graytechnos co., &lttttranslation = L "&tttl &/t &ttt TD..

Thereafter, both ends were fixed to a bobbin with tapes, and after standing at 105 ℃ for 1000 hours, the light quantity was measured again in the same manner, the difference in light quantity from the "initial value" was measured, and the case where the light quantity difference was 3dB or less was evaluated as acceptable.

((2)UL VW-1)

Flame retardancy was measured according to the U L VW-1 standard.

(3) Heat shrinkage (measurement of Heat shrinkage)

The plastic optical fiber cable was cut into 1m pieces with an industrial razor at room temperature (23 ℃) to flatten both ends, heated at 105 ℃ for 1 hour, cooled to room temperature, and measured for the length of the cable, and the shrinkage was determined according to the following formula. The evaluation was 1% or less as a pass.

Heat shrinkage factor (1 m-cable length after test)/1 m × 100 (%)

[ example 1]

In the plastic optical fiber with a protective layer, a polyamide 12 resin (Vestamid N1901 manufactured by Daicel-Evonik L td.) having a thickness of 0.15mm and serving as a protective layer was formed by extrusion molding on a plastic optical fiber SHB-1000(1 core, core material PMMA, wire diameter 1.0mm manufactured by asahi chemical co., ltd.) having a heat shrinkage ratio of 0.8%, and a plastic optical fiber cable was manufactured by forming a covering layer using a flame retardant polyethylene composition having the following composition as a covering material and forming a diameter of 2.2mm after the covering layer was added.

The heat resistance, flame retardancy and heat shrinkage were measured and evaluated by the methods described above.

The evaluation results are shown in table 1.

The heat shrinkage of the wire rod was measured by the same method as described above ((3) heat shrinkage (measurement of heat shrinkage)).

15 parts by mass of DHDA-1184NTJ (Dihydronaphthalene-Dithiopropionic acid) prepared from polyethylene resin NUC (non-uniform nucleating agent)

NUC-319520 parts by mass of polyethylene resin NUC

Polyethylene resin Rexpearl EEA 115020 part by mass manufactured by Japan polyethylene Co., Ltd

Magnesium hydroxide Kisuma5A 40 parts by mass manufactured by Kyoho chemical industries Co., Ltd

RINKA _ FE140F 5 parts by mass, manufactured by HONGPHOSPHORUS CORPORATION CHEMICAL INDUSTRIAL CO

[ example 2]

As the covering material, PVC (polyvinyl chloride RIKEN TECHNOS CORP, manufactured by SMV9993S) was used.

Other conditions were the same as in [ example 1] above, and a plastic optical fiber cable was produced and evaluated in the same manner.

[ example 3]

PVDF (PVDF 31008/0003, manufactured by 3M Co., Ltd.) was used as the covering material.

[ example 4]

PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer DAIKINDUSTRIES, &lTtT transfer = L "&gTt L &lTt/T &gTt TD., manufactured by AP-201) was used as the covering material.

[ example 5 ]

A plastic optical fiber SHB-1000(1 core, core material PMMA, line diameter 1.0mm manufactured by Asahi chemical Co., Ltd.) was coated with a coating layer without forming a protective layer.

Other conditions were the same as in [ example 3] above, and a plastic optical fiber cable was produced and evaluated in the same manner.

[ example 6 ]

As the plastic optical fiber with a protective layer, a plastic optical fiber SHB-500 (core material PMMA, a wire diameter of 0.5mm manufactured by Asahi chemical Co., Ltd.) was used, which was obtained by extrusion molding a polyamide 12 resin (Vestamid N1901 manufactured by Daicel-Evonik L td.) as a protective layer with a thickness of 0.25mm, and other conditions were evaluated in the same manner as in the above [ example 1 ].

[ example 7 ]

As the plastic optical fiber, SHMBK-1000P (19 core material PMMA, manufactured by Asahi chemical Co., Ltd., diameter of the fiber: 1.0mm) having a heat shrinkage ratio of 0.9% was used.

[ example 8 ]

A plastic optical fiber wire EB-1000(1 core, core material PMMA, wire diameter 1.0mm manufactured by Asahi chemical Co., Ltd.) having a heat shrinkage of 2.0% was used.

Other conditions were the same as in [ example 1] above, and after a plastic optical fiber cable was produced, the cable was left standing at 105 ℃ for 10 hours, and after aging treatment, the cable was evaluated in the same manner as in [ example 1 ].

[ example 9 ]

A plastic optical fiber cable was produced in the same manner as in [ example 1] above. Thereafter, the mixture was left standing at 105 ℃ for 10 hours to effect aging treatment, and then evaluated in the same manner as in example 1.

[ comparative example 1]

Polyethylene (M1920, asahi chemical corporation) was used as the covering material.

Other conditions were the same as in [ example 5 ] above, and a plastic optical fiber cable was produced and evaluated in the same manner.

[ comparative example 2]

A plastic optical fiber SHB-1000(1 core, core material PMMA, line diameter 1.0mm manufactured by Asahi chemical Co., Ltd.) was coated with a coating layer without adding a protective layer.

Other conditions were the same as in [ example 2] above, and a plastic optical fiber cable was produced and evaluated in the same manner.

[ comparative example 3]

The same evaluation as in [ example 1] was carried out on a plastic optical fiber obtained by extrusion molding of a polyamide 12 resin (Vestamid N1901 manufactured by Daicel-Evonik L td.) as a coating layer on a plastic optical fiber SHB-1000(1 core, core material PMMA, wire diameter 1.0mm manufactured by Asahi chemical Co., Ltd.) with a thickness of 0.15 mm.

In the heat resistance test, the connector was mounted by filling a gap between the connector and the plastic optical fiber wire with a protective layer with an epoxy resin (Highsuper 30, manufactured by Cemedine corporation).

[ comparative example 4]

Other conditions were the same as in [ example 1] above, and a plastic optical fiber cable was produced and evaluated in the same manner as in [ example 1 ].

[ comparative example 5 ]

A plastic optical fiber wire TB-1000(1 core, core PMMA, wire diameter 1.0mm manufactured by Asahi chemical Co., Ltd.) having a heat shrinkage of 2.0% was used.

[ Table 1]

[ Table 2]

Examples 1 to 9 have a thermal shrinkage of 1% or less and satisfy U L-VW-1.

These examples all met the heat resistance test.

In comparative example 1, the heat shrinkage was 1% or less, but the test was not satisfactory in the U L VW-1 test, and the heat resistance test was not satisfactory.

In comparative example 2, the test was satisfied with the U L VW-1, but the heat shrinkage was more than 1%, and the heat resistance test was not satisfactory.

In comparative example 3, the heat shrinkage rate exceeded 1%, and the test was not satisfactory in the U L VW-1 test, nor in the heat resistance test.

In comparative example 4, the test was satisfied with the U L VW-1 test, but the heat shrinkage was more than 1%, and the heat resistance test was not satisfactory.

In comparative example 5, the test was satisfied with the U L VW-1 test, but the heat shrinkage was more than 1%, and the heat resistance test was not satisfactory.

Industrial applicability

The plastic optical fiber of the present invention is industrially applicable as a communication cable, an optical fiber sensor, and the like in electronic equipment and between equipments.

Claims

1. A plastic optical fiber cable is provided with:

a plastic optical fiber wire having 1 or 2 or more cores and at least 1 layer of sheath layer formed on the outer periphery of the cores;

a covering layer formed on an outer periphery of the plastic optical fiber; and

a protective layer between the plastic optical fiber wire and the cover layer,

the cover layer contains 1 or more resins selected from the group consisting of flame retardant polyethylene, polyvinylidene fluoride, tetrafluoroethylene-ethylene copolymer (ETFE), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA), and silicone resin,

meets the standard of U L VW-1.

2. The plastic optical fiber cable according to claim 1,

the protective layer has a tensile yield strength of 20MPa or more according to JIS K7113.

3. The plastic optical fiber cable according to claim 1 or 2,