Optical fibers and optical fiber ribbons

Abstract

This resin composition for an optical fiber coating contains a photopolymerizable compound, a photopolymerization initiator, and surface-treated copper phthalocyanine particles. The surface-treated copper phthalocyanine particle content is 0.1-10 mass% based on the total amount of the resin composition.

Description

Resin composition for optical fiber coating, colored coating material for optical fiber, optical fiber, and optical fiber ribbon

[0001] This disclosure relates to a resin composition for optical fiber coating, a colored coating material for optical fibers, an optical fiber, and an optical fiber ribbon. This application claims priority to Japanese Application No. 2023-132291, filed August 15, 2023, and incorporates by reference all of the contents of said Japanese application.

[0002] Generally, optical fibers have a resin coating layer to protect the glass fiber that transmits light. The resin coating layer includes, for example, a primary resin layer and a secondary resin layer. The outermost layer of the resin coating layer is a colored resin layer for identifying the optical fiber (see, for example, Patent Documents 1 to 3).

[0003] Japanese Patent Application Laid-Open No. 6-242355 Japanese Patent Application Laid-Open No. 2003-279811 International Publication No. 2016 / 047002

[0004] A resin composition for optical fiber coating according to one embodiment of the present disclosure contains a photopolymerizable compound, a photopolymerization initiator, and surface-treated copper phthalocyanine particles, and the content of the surface-treated copper phthalocyanine particles is 0.1 mass % or more and 10 mass % or less based on the total amount of the resin composition.

[0005] Fig. 1 is a schematic cross-sectional view showing an example of an optical fiber according to the present embodiment. Fig. 2 is a schematic cross-sectional view showing an example of an optical fiber according to the present embodiment. Fig. 3 is a schematic cross-sectional view showing an example of an optical fiber ribbon according to the present embodiment.

[0006] [Problem to be Solved by the Present Disclosure] Optical fibers are sometimes used in the form of an optical fiber ribbon in which a plurality of optical fibers are arranged and integrated with a ribbon resin. In an optical fiber ribbon using optical fibers having a colored resin layer, if there are protrusions on the surface of the colored resin layer, the adhesion between the colored resin layer and the ribbon material becomes locally strong, and when the ribbon material is removed to extract the optical fibers, a phenomenon known as "color peeling" may occur in which the colored resin layer peels off from the optical fibers.

[0007] An object of the present disclosure is to provide a resin composition for optical fiber coating that can produce optical fibers that are less susceptible to color peeling, a colored coating material for optical fibers, an optical fiber, and an optical fiber ribbon.

[0008] [Effects of the Present Disclosure] According to the present disclosure, it is possible to provide a resin composition for optical fiber coating, a colored coating material for optical fiber, an optical fiber, and an optical fiber ribbon, which can produce an optical fiber that is resistant to color peeling.

[0009] [Description of Embodiments of the Present Disclosure] First, the contents of the embodiments of the present disclosure will be listed and described.

[0010] (1) A resin composition for optical fiber coating according to one embodiment of the present disclosure contains a photopolymerizable compound, a photopolymerization initiator, and surface-treated copper phthalocyanine particles, and the content of the surface-treated copper phthalocyanine particles is 0.1 mass % or more and 10 mass % or less based on the total amount of the resin composition.

[0011] By containing surface-treated copper phthalocyanine particles in a specific range, such a resin composition can produce an optical fiber that is less susceptible to color peeling.

[0012] (2) In the above (1), in order to make color peeling less likely to occur, the surface-treated copper phthalocyanine particles may have a surface treatment layer derived from a rosin compound containing at least one selected from the group consisting of abietic acid, dehydroabietic acid, and tetrahydroabietic acid.

[0013] (3) In the above (1) or (2), from the viewpoint of dispersibility, the amount of the surface treatment layer in the surface-treated copper phthalocyanine particles may be 1% by mass or more and 20% by mass or less.

[0014] (4) In any of the above (1) to (3), the photopolymerizable compound may contain epoxy di(meth)acrylate in order to increase the strength of the resin layer.

[0015] (5) A colored coating material for an optical fiber according to an aspect of the present disclosure includes the resin composition according to any one of (1) to (4). By using the resin composition according to this embodiment for the colored resin layer, an optical fiber that is less susceptible to color peeling can be produced.

[0016] (6) An optical fiber according to one aspect of the present disclosure includes a glass fiber including a core and a cladding, a primary resin layer that contacts and coats the glass fiber, a secondary resin layer that coats the primary resin layer, and a colored resin layer that coats the secondary resin layer, wherein the colored resin layer contains a cured product of the resin composition according to any one of (1) to (4). Such an optical fiber is resistant to color peeling.

[0017] (7) An optical fiber according to one aspect of the present disclosure includes a glass fiber including a core and a cladding, a primary resin layer that contacts and coats the glass fiber, and a secondary resin layer that coats the primary resin layer, wherein the secondary resin layer contains a cured product of the resin composition according to any one of (1) to (4). Such an optical fiber is resistant to color peeling.

[0018] (8) An optical fiber ribbon according to an aspect of the present disclosure includes a plurality of optical fibers according to (6) or (7) arranged in parallel and coated with a ribbon resin. Such an optical fiber ribbon is less likely to peel off when the optical fibers are removed, and the optical fibers can be easily identified.

[0019] [Details of the Embodiments of the Present Disclosure] Specific examples of resin compositions, optical fibers, and optical fiber ribbons according to the embodiments of the present disclosure will be described with reference to the drawings as necessary. The present disclosure is not limited to these examples, but is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims. In the following description, the same elements in the drawings will be designated by the same reference numerals, and redundant explanations will be omitted. In this specification, (meth)acrylate means acrylate or the corresponding methacrylate. The same applies to other similar expressions such as (meth)acryloyl.

[0020] (Resin Composition) The resin composition for optical fiber coating according to this embodiment contains a photopolymerizable compound, a photopolymerization initiator, and surface-treated copper phthalocyanine particles, and the content of the surface-treated copper phthalocyanine particles is 0.1 mass % or more and 10 mass % or less based on the total amount of the resin composition.

[0021] It is known that copper phthalocyanine particles are added as an organic pigment when forming a colored resin layer on an optical fiber. However, poor dispersion of the copper phthalocyanine particles can cause unevenness on the surface of the optical fiber, which can lead to color peeling. In contrast, surface-treated copper phthalocyanine particles can improve dispersibility in the resin composition.

[0022] The surface-treated copper phthalocyanine particles may be, for example, copper phthalocyanine particles treated with a surface treatment agent containing a rosin compound. The surface-treated copper phthalocyanine particles may have a surface treatment layer derived from a rosin compound. The rosin compound contains components such as abietic acid, dehydroabietic acid, and tetrahydroabietic acid. The surface-treated copper phthalocyanine particles may have a surface treatment layer derived from a rosin compound containing at least one acid selected from the group consisting of abietic acid, dehydroabietic acid, and tetrahydroabietic acid, thereby further improving dispersibility. The surface treatment layer may be formed on at least a portion of the surface of the copper phthalocyanine particles, or may be formed on the entire surface of the copper phthalocyanine particles.

[0023] The amount of the surface treatment layer in the surface-treated copper phthalocyanine particles may be 1 mass % or more, 2 mass % or more, 3 mass % or more, or 4 mass % or more from the viewpoint of further improving dispersibility, and may be 20 mass % or less, 15 mass % or less, 10 mass % or less, 8 mass % or less, or 6 mass % or less from the viewpoint of improving hiding power. The amount of the surface treatment layer can be calculated by analyzing the surface-treated copper phthalocyanine particles using a pyrolysis gas chromatograph mass spectrometer.

[0024] The average particle size of the surface-treated copper phthalocyanine particles may be 1,000 nm or less, 800 nm or less, 500 nm or less, 300 nm or less, 200 nm or less, or 150 nm or less, from the viewpoint of further improving dispersibility. The average particle size of the surface-treated copper phthalocyanine particles may be 1 nm or more, 10 nm or more, 50 nm or more, or 80 nm or more, or may be 50 nm or more and 300 nm or less, from the viewpoint of improving coloring power. The average particle size can be measured, for example, by image analysis of an electron microscope photograph, a light scattering method, a BET method, or the like.

[0025] The content of the surface-treated copper phthalocyanine particles may be 0.2 mass% or more, 0.4 mass% or more, 0.6 mass% or more, or 0.8 mass% or more based on the total amount of the resin composition from the viewpoint of improving the visibility of the resin layer. The content of the surface-treated copper phthalocyanine particles may be 9 mass% or less, 8 mass% or less, 7 mass% or less, or 6 mass% or less based on the total amount of the resin composition from the viewpoint of further improving dispersibility.

[0026] The photopolymerizable compound is not particularly limited, but may contain epoxy di(meth)acrylate from the viewpoint of increasing the strength of the resin layer. As the epoxy di(meth)acrylate, a reaction product of a diglycidyl ether compound having a bisphenol skeleton and a compound having a (meth)acryloyl group, such as (meth)acrylic acid, can be used. The epoxy di(meth)acrylate may be used alone or in combination of two or more.

[0027] Examples of epoxy di(meth)acrylates include (meth)acrylic acid adducts of bisphenol A diglycidyl ether, (meth)acrylic acid adducts of bisphenol AF diglycidyl ether, and (meth)acrylic acid adducts of bisphenol F diglycidyl ether.

[0028] From the viewpoint of further increasing the strength of the resin layer, the content of the epoxy di(meth)acrylate may be 30 parts by mass or more, 40 parts by mass or more, or 45 parts by mass or more, relative to 100 parts by mass of the total amount of the photopolymerizable compound, and may be 70 parts by mass or less, 65 parts by mass or less, or 60 parts by mass or less.

[0029] The photopolymerizable compound may further contain a urethane (meth)acrylate from the viewpoint of adjusting the Young's modulus of the resin layer. As the urethane (meth)acrylate, for example, a reaction product of a polyol compound, a polyisocyanate compound, and a hydroxyl group-containing (meth)acrylate compound can be used. The urethane (meth)acrylate may be used alone or in combination of two or more.

[0030] Examples of polyol compounds include polytetramethylene glycol, polypropylene glycol, and bisphenol A-ethylene oxide addition diol. Examples of polyisocyanate compounds include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, isophorone diisocyanate, and dicyclohexylmethane 4,4'-diisocyanate. Examples of hydroxyl group-containing (meth)acrylate compounds include 2-hydroxyethyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 1,6-hexanediol mono(meth)acrylate, pentaerythritol tri(meth)acrylate, 2-hydroxypropyl (meth)acrylate, and tripropylene glycol mono(meth)acrylate.

[0031] From the viewpoint of adjusting the Young's modulus of the resin layer, the number average molecular weight (Mn) of the polyol compound may be 300 or more and 3,000 or less, 400 or more and 3,000 or less, or 500 or more and 2,500 or less.

[0032] Organotin compounds are generally used as catalysts for synthesizing urethane (meth)acrylates. Examples of organotin compounds include dibutyltin dilaurate, dibutyltin diacetate, dibutyltin maleate, dibutyltin bis(2-ethylhexyl mercaptoacetate), dibutyltin bis(isooctyl mercaptoacetate), and dibutyltin oxide. From the viewpoint of easy availability or catalytic performance, dibutyltin dilaurate or dibutyltin diacetate may be used as the catalyst.

[0033] When synthesizing the urethane (meth)acrylate, a lower alcohol having 5 or less carbon atoms may be used. Examples of the lower alcohol include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methyl-2-propanol, 1-pentanol, 2-pentanol, 3-pentanol, 2-methyl-1-butanol, 3-methyl-1-butanol, 2-methyl-2-butanol, 3-methyl-2-butanol, and 2,2-dimethyl-1-propanol.

[0034] The photopolymerizable compound may further include a photopolymerizable compound (hereinafter referred to as a "monomer") other than epoxy di(meth)acrylate and urethane (meth)acrylate.

[0035] Examples of the monomer include a monofunctional monomer having one polymerizable group and a polyfunctional monomer having two or more polymerizable groups. The monomer may be used alone or in combination of two or more.

[0036] Examples of monofunctional monomers include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, s-butyl (meth)acrylate, tert-butyl (meth)acrylate, isobutyl (meth)acrylate, n-pentyl (meth)acrylate, isopentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, isoamyl (meth)acrylate, and 2-ethylhexyl (meth)acrylate. (Meth)acrylate monomers such as acrylate, n-octyl (meth)acrylate, isooctyl (meth)acrylate, isodecyl (meth)acrylate, lauryl (meth)acrylate, 2-phenoxyethyl (meth)acrylate, 3-phenoxybenzyl acrylate, phenoxydiethylene glycol acrylate, phenoxypolyethylene glycol acrylate, 4-tert-butylcyclohexanol acrylate, tetrahydrofurfuryl (meth)acrylate, benzyl (meth)acrylate, dicyclopentenyl (meth)acrylate, dicyclopentenyloxyethyl (meth)acrylate, dicyclopentanyl (meth)acrylate, nonylphenol polyethylene glycol (meth)acrylate, nonylphenoxypolyethylene glycol (meth)acrylate, and isobornyl (meth)acrylate; (meth)acrylic acid, (meth)acrylic acid dimer, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, ω-carboxymethyl (meth)acrylate, Carboxy group-containing monomers such as carboxy-polycaprolactone (meth)acrylate; heterocycle-containing monomers such as N-(meth)acryloylmorpholine, N-vinylpyrrolidone, N-vinylcaprolactam, N-(meth)acryloylpiperidine, N-(meth)acryloylpyrrolidine, 3-(3-pyridine)propyl (meth)acrylate, and cyclic trimethylolpropane formal acrylate; maleimide-based monomers such as maleimide, N-cyclohexylmaleimide, and N-phenylmaleimide;Amide-based monomers such as (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N,N-diethyl(meth)acrylamide, N-hexyl(meth)acrylamide, N-methyl(meth)acrylamide, N-ethyl(meth)acrylamide, N-butyl(meth)acrylamide, N-methylol(meth)acrylamide, and N-methylolpropane(meth)acrylamide; aminoalkyl (meth)acrylate-based monomers such as aminoethyl (meth)acrylate, aminopropyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and tert-butylaminoethyl (meth)acrylate; and succinimide-based monomers such as N-(meth)acryloyloxymethylene succinimide, N-(meth)acryloyl-6-oxyhexamethylene succinimide, and N-(meth)acryloyl-8-oxyoctamethylene succinimide.

[0037] Examples of polyfunctional monomers include polyethylene glycol di(meth)acrylate, isocyanuric acid ethylene oxide modified di(meth)acrylate, ethylene oxide modified bisphenol F di(meth)acrylate, ethylene oxide modified bisphenol A di(meth)acrylate, polypropylene glycol di(meth)acrylate, propylene oxide modified bisphenol A di(meth)acrylate, propylene oxide modified neopentyl glycol di(meth)acrylate, polytetraethylene glycol di(meth)acrylate, Acrylates, hydroxypivalic acid neopentyl glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, 1,12-dodecanediol di(meth)acrylate, 1,14-tetradecanediol di(meth)acrylate, 1,16-hexadecanediol di(meth)acrylate, 1,20-eicosanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, isopentyl glycol di(meth)acrylate, diethyl-1,8-octanediol di(meth)acrylate, 3-ethyl-1,8-octanediol di(meth)acrylate; trimethylolpropane tri(meth)acrylate, trimethyloloctane tri(meth)acrylate, trimethylolpropane polyethoxy tri(meth)acrylate, trimethylolpropane polypropoxy tri(meth)acrylate, trimethylolpropane polyethoxypolypropoxy tri(meth)acrylate, tris[(meth)acryloyloxyethyl]isocyanurate, pentaerythritol tri(meth)acrylate acrylate, pentaerythritol polyethoxytetra(meth)acrylate, pentaerythritol polypropoxytetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and caprolactone-modified tris[(meth)acryloyloxyethyl]isocyanurate.

[0038] The photopolymerizable compound may contain an alkylene oxide-modified polyfunctional monomer from the viewpoint of adjusting the Young's modulus of the resin layer. The alkylene oxide-modified polyfunctional monomer may have at least one selected from the group consisting of an ethylene oxide (EO) chain and a propylene oxide (PO) chain. The ethylene oxide chain can be represented as "(EO)n" and the propylene oxide chain as "(PO)n". n is an integer of 1 or more, and may be 2 or more or 3 or more, or may be 30 or less, 25 or less, or 20 or less. Examples of the alkylene oxide-modified polyfunctional monomer include alkylene oxide-modified di(meth)acrylates and alkylene oxide-modified tri(meth)acrylates.

[0039] Examples of alkylene oxide-modified di(meth)acrylates include polyethylene glycol di(meth)acrylate, isocyanuric acid ethylene oxide-modified di(meth)acrylate, ethylene oxide-modified bisphenol F di(meth)acrylate, ethylene oxide-modified bisphenol A di(meth)acrylate, polypropylene glycol di(meth)acrylate, propylene oxide-modified bisphenol A di(meth)acrylate, and propylene oxide-modified neopentyl glycol di(meth)acrylate.

[0040] Examples of alkylene oxide-modified tri(meth)acrylates include trimethylolpropane tri(meth)acrylate, trimethyloloctane tri(meth)acrylate, trimethylolpropane polyethoxy tri(meth)acrylate, trimethylolpropane polypropoxy tri(meth)acrylate, trimethylolpropane polyethoxypolypropoxy tri(meth)acrylate, tris[(meth)acryloyloxyethyl]isocyanurate, and pentaerythritol tri(meth)acrylate.

[0041] The photopolymerization initiator can be appropriately selected from known radical photopolymerization initiators. Examples of the photopolymerization initiator include 1-hydroxycyclohexyl phenyl ketone (Omnirad 184, manufactured by IGM Resins), 2,2-dimethoxy-2-phenylacetophenone, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropan-1-one, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one (Omnirad 907, manufactured by IGM Resins), 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Omnirad TPO H, manufactured by IGM Resins), and ethyl phenyl(2,4,6-trimethylbenzoyl)phosphinate (Omnirad TPO-L, manufactured by IGM Resins). Resins), tri[phenyl(2,4,6-trimethylbenzoyl)phosphinic acid] polyethylene glycol ester (Omnipol TP, IGM Resins), and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (Omnirad 819, IGM Resins).

[0042] The content of the photopolymerization initiator may be 1 part by mass or more and 10 parts by mass or less, 2 parts by mass or more and 8 parts by mass or less, or 3 parts by mass or more and 7 parts by mass or less, relative to 100 parts by mass of the total amount of the photopolymerizable compounds.

[0043] The resin composition according to this embodiment may further contain a polydimethylsiloxane compound from the viewpoint of the lateral pressure resistance of the optical fiber. The polydimethylsiloxane compound has a dimethylsiloxane skeleton (—Si(CH ３ ) ２ O-) as a repeating unit.

[0044] The amount of silicon atoms (Si) contained in the polydimethylsiloxane compound may be 6% by mass or more, 8% by mass or more, 10% by mass or more, or 12% by mass or more from the viewpoint of lateral pressure resistance. From the viewpoint of stability of the resin composition, the amount of Si may be 40% by mass or less, 30% by mass or less, 25% by mass or less, or 21% by mass or less. The amount of Si contained in the polydimethylsiloxane compound can be measured by inductively coupled plasma optical emission spectroscopy (ICP-OES) of the polydimethylsiloxane compound.

[0045] From the viewpoints of lateral pressure resistance and hot water resistance, the polydimethylsiloxane compound may have at least one organic group selected from the group consisting of a (meth)acryloyl group, an epoxy group, and a polyether group. That is, from the viewpoints of lateral pressure resistance and hot water resistance, the polydimethylsiloxane compound may include at least one selected from the group consisting of a polydimethylsiloxane compound having a (meth)acryloyl group, a polydimethylsiloxane compound having an epoxy group, and a polydimethylsiloxane compound having a polyether group. The polydimethylsiloxane compound may have these organic groups on a side chain or at a terminal. Among these organic groups, from the viewpoints of lateral pressure resistance and hot water resistance, (meth)acryloyl groups and epoxy groups may be used, or a (meth)acryloyl group may be used.

[0046] A polydimethylsiloxane compound having a (meth)acryloyl group can be copolymerized with the above-mentioned photopolymerizable compound. A polydimethylsiloxane compound having a (meth)acryloyl group is not included in the above-mentioned photopolymerizable compound. The number of (meth)acryloyl groups contained in the polydimethylsiloxane compound may be 1 or more or 2 or more, and 10 or less or 8 or less. The number of epoxy groups contained in the polydimethylsiloxane compound may be 1 or more or 2 or more, and 10 or less or 8 or less. The number of polyether groups contained in the polydimethylsiloxane compound may be 1 or more or 2 or more, and 10 or less or 8 or less.

[0047] From the viewpoint of lateral pressure resistance and warm water resistance, the content of the polydimethylsiloxane compound may be 0.5 parts by mass or more and 5.0 parts by mass or less, 1.0 parts by mass or more and 4.0 parts by mass or less, or 1.5 parts by mass or more and 3.0 parts by mass or less, relative to 100 parts by mass of the total amount of the photopolymerizable compounds.

[0048] The resin composition according to this embodiment may further contain a silane coupling agent, a leveling agent, an antifoaming agent, an antioxidant, a sensitizer, and the like.

[0049] The silane coupling agent is not particularly limited as long as it does not interfere with the curing of the resin composition. Examples of the silane coupling agent include tetramethyl silicate, tetraethyl silicate, mercaptopropyltrimethoxysilane, vinyltrichlorosilane, vinyltriethoxysilane, vinyltris(β-methoxyethoxy)silane, β-(3,4-epoxycyclohexyl)-ethyltrimethoxysilane, dimethoxydimethylsilane, diethoxydimethylsilane, 3-acryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldiethoxysilane, γ-methacryloxypropyltrimethoxysilane, N-(β-aminoethyl)-γ N-aminopropyltrimethoxysilane, N-(β-aminoethyl)-γ-aminopropyltrimethyldimethoxysilane, N-phenyl-γ-aminopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, bis-[3-(triethoxysilyl)propyl]tetrasulfide, bis-[3-(triethoxysilyl)propyl]disulfide, γ-trimethoxysilylpropyldimethylthiocarbamoyltetrasulfide, and γ-trimethoxysilylpropylbenzothiazyltetrasulfide.

[0050] The viscosity at 25°C of the resin composition according to this embodiment may be 1000 mPa·s or more, 1500 mPa·s or more, or 2000 mPa·s or more from the viewpoint of storage stability, and may be less than 10000 mPa·s, 8000 mPa·s or less, or 6000 mPa·s or less from the viewpoint of coatability.

[0051] From the viewpoint of improving the single-fiber separation property of the optical fiber, the resin composition is applied at 1000±100 mJ / cm ２ The Young's modulus of the resin film when UV-cured under the conditions above may be 500 MPa or more, 600 MPa or more, or 700 MPa or more at 23° C. From the viewpoint of forming a resin layer having excellent toughness, the Young's modulus of the resin film may be 1500 MPa or less, 1400 MPa or less, or 1300 MPa or less at 23° C.

[0052] The resin composition according to the present embodiment can be suitably used as a colored coating material for optical fibers. By forming the outermost layer of a resin coating layer using a colored coating material containing the resin composition according to the present embodiment, an optical fiber that is resistant to color peeling can be produced.

[0053] (Optical Fiber) Fig. 1 is a schematic cross-sectional view showing the configuration of an optical fiber according to one embodiment. As shown in Fig. 1, the optical fiber 1 of this embodiment includes a glass fiber 10 and a coating resin layer 20 that contacts the glass fiber 10 and covers the outer periphery of the glass fiber 10.

[0054] The glass fiber 10 is a light-guiding optical transmission body that transmits light introduced into the optical fiber 1. The glass fiber 10 is a glass member, and is made of, for example, silica (SiO ２ The glass fiber 10 includes a core 12 and a cladding 14 that covers the core 12. The glass fiber 10 transmits light introduced into the optical fiber 1. The core 12 is provided, for example, in a region that includes the central axis of the glass fiber 10. The core 12 is made of, for example, pure SiO ２ Glass or SiO ２ Glass with germanium dioxide (GeO ２ The cladding 14 is formed from a material containing fluorine or the like. The cladding 14 is provided in a region surrounding the core 12. The cladding 14 has a refractive index lower than that of the core 12. The cladding 14 is formed from, for example, pure SiO ２ Glass or fluorine-doped SiO ２The glass fiber 10 is made of glass and has an outer diameter of about 100 μm to 125 μm, and a core 12 included in the glass fiber 10 has a diameter of about 7 μm to 15 μm.

[0055] The coating resin layer 20 is an ultraviolet-curable resin layer that covers the clad 14. The coating resin layer 20 includes a primary resin layer 22 that coats the outer periphery of the glass fiber 10, a secondary resin layer 24 that coats the outer periphery of the primary resin layer 22, and a colored resin layer 26 that coats the outer periphery of the secondary resin layer 24. The primary resin layer 22 is in contact with the outer periphery of the clad 14 and coats the entire clad 14. The secondary resin layer 24 is in contact with the outer periphery of the primary resin layer 22 and coats the entire primary resin layer 22. The colored resin layer 26 is in contact with the outer periphery of the secondary resin layer 24 and coats the outer periphery of the secondary resin layer 24.

[0056] The thickness of the primary resin layer 22 is, for example, 10 μm or more and 50 μm or less, the thickness of the secondary resin layer 24 is, for example, 10 μm or more and 40 μm or less, and the thickness of the colored resin layer 26 is, for example, 3 μm or more and 10 μm or less.

[0057] The primary resin layer 22 may be formed using a conventionally known resin composition for primary resin layers, for example, by curing a resin composition containing urethane (meth)acrylate, a monomer, a photopolymerization initiator, and a silane coupling agent.

[0058] The secondary resin layer 24 may be formed using a conventionally known resin composition for secondary resin layers, for example, by curing a resin composition containing urethane (meth)acrylate, a monomer, and a photopolymerization initiator.

[0059] The resin composition according to this embodiment can be applied to the colored resin layer 26. The colored resin layer 26 can be formed by curing the resin composition. By including the cured product of the resin composition according to this embodiment, the colored resin layer 26 can make the optical fiber less susceptible to color peeling.

[0060] Fig. 2 is a schematic cross-sectional view showing the configuration of an optical fiber according to one embodiment. As shown in Fig. 2, the optical fiber 1A includes a glass fiber 10 and a coating resin layer 20A that contacts the glass fiber 10 and covers the outer periphery of the glass fiber 10. The coating resin layer 20A includes a primary resin layer 22 and a secondary resin layer 24.

[0061] The resin composition according to this embodiment can be applied to the secondary resin layer 24. The secondary resin layer 24 can be formed by curing the resin composition. In this case, the secondary resin layer 24 functions as a colored secondary resin layer. By including a cured product of the resin composition according to this embodiment, the secondary resin layer 24 can make the optical fiber less susceptible to color peeling.

[0062] (Optical Fiber Ribbon) The optical fibers according to this embodiment can be used to fabricate an optical fiber ribbon, which is formed by arranging a plurality of the optical fibers in parallel and coating them with a ribbon resin.

[0063] 3 is a schematic cross-sectional view showing an optical fiber ribbon according to this embodiment. The optical fiber ribbon 100 includes a plurality of optical fibers 1 and a connecting resin layer 40 in which the optical fibers 1 are coated with a ribbon resin and connected. In FIG. 3, four optical fibers are shown as an example, but the number is not particularly limited.

[0064] The ribbon resin may be a resin material generally known as a ribbon material. From the viewpoint of preventing damage to the optical fiber and facilitating separation, the ribbon resin may contain a thermosetting resin such as a silicone resin, an epoxy resin, or a urethane resin, or an ultraviolet-curing resin such as an epoxy acrylate, a urethane acrylate, or a polyester acrylate.

[0065] By using the above-mentioned optical fiber, the optical fiber ribbon of this embodiment does not experience color peeling when removing the connecting resin layer from the optical fiber ribbon to extract the optical fiber, and the optical fiber can be easily identified.

[0066] The present disclosure will be described in more detail below by showing the results of evaluation tests using examples and comparative examples according to the present disclosure. Note that the present disclosure is not limited to these examples.

[0067] [Resin Composition for Colored Resin] The following components were prepared to prepare a resin composition for colored resin. (Photopolymerizable Compound) EA: Bisphenol A epoxy diacrylate PPGDA: Polypropylene glycol diacrylate (PO number: 3) TMP(EO) ３ TA: Trimethylolpropane EO adduct triacrylate (EO number: 3) TMP(EO) １５ TA: Trimethylolpropane EO adduct triacrylate (EO number: 15) BPA (EO) ３０ DA: EO-modified bisphenol A di(meth)acrylate (EO number: 30) (photopolymerization initiator) Omnirad 184: 1-hydroxycyclohexyl phenyl ketone Omnirad TPO H: 2,4,6-trimethylbenzoyldiphenylphosphine oxide (copper phthalocyanine particles) A1: Copper phthalocyanine particles surface-treated with a rosin compound containing abietic acid as the main component (average particle size: 100 nm, amount of surface treatment layer: 5% by mass) A2: Copper phthalocyanine particles surface-treated with a rosin compound containing dehydroabietic acid as the main component (average particle size: 100 nm, amount of surface treatment layer: 5% by mass) A3: Copper phthalocyanine particles surface-treated with a rosin compound containing tetrahydroabietic acid as the main component (average particle size: 100 nm, amount of surface treatment layer: 5% by mass) A4: Copper phthalocyanine particles without surface treatment (average particle size: 100 nm) (Polydimethylsiloxane Compound) PDMS: Polydimethylsiloxane compound having a Si content of 21% by mass

[0068] (Test Examples 1 to 6) Resin compositions were prepared by mixing the photopolymerizable compound, photopolymerization initiator, and polydimethylsiloxane compound in the amounts (parts by mass) shown in Table 1 with the copper phthalocyanine particles in the amount (% by mass) shown in Table 1. The content of the copper phthalocyanine particles is a value based on the total amount of the resin composition. Test Examples 1 to 5 correspond to Examples, and Test Example 6 corresponds to a Comparative Example.

[0069] (Young's modulus) After applying the resin composition onto a polyethylene terephthalate (PET) film using a spin coater, the resin composition was irradiated with 1000±100 mJ / cm using an electrodeless UV lamp system (Heraeus VPS600 (D bulb)). ２ The resin layer was peeled off from the PET film to obtain a resin film.

[0070] The resin film was punched into a dumbbell shape conforming to JIS K 7127 Type 5 and stretched using a tensile tester at 23±2°C, 50±10% RH, a tension rate of 1 mm / min, and a gauge length of 25 mm to obtain a stress-strain curve. The film Young's modulus was determined using the 2.5% secant line.

[0071] (Dispersibility) 1 g of the resin composition was diluted with 50 mL of methyl ethyl ketone, and 1 mL of the diluted solution was added to 100 mL of an electrolyte (a methyl ethyl ketone solution containing 2% by mass of sodium thiocyanate) to prepare a measurement solution. Using a measurement device (manufactured by Beckman Coulter, Inc., product name: Multisizer 4e, aperture: 50 μm), the number of particles with a particle size of 5 μm or more (agglomerated particles of copper phthalocyanine particles) contained in 100 mL of the measurement solution was measured by a Cole counter method. The fewer the number of particles with a particle size of 5 μm or more, the better the dispersibility of the copper phthalocyanine particles.

[0072] [Resin composition for primary resin layer] A urethane acrylate obtained by reacting polypropylene glycol having a molecular weight of 4000, isophorone diisocyanate, hydroxyethyl acrylate, and methanol was prepared. 75 parts by mass of this urethane acrylate, 12 parts by mass of nonylphenol EO-modified acrylate, 6 parts by mass of N-vinyl caprolactam, 2 parts by mass of 1,6-hexanediol diacrylate, 1 part by mass of Omnirad TPO H, and 1 part by mass of 3-mercaptopropyltrimethoxysilane were mixed to prepare resin composition P.

[0073] [Resin composition for secondary resin layer] A urethane acrylate obtained by reacting polypropylene glycol having a molecular weight of 600, 2,4-tolylene diisocyanate, and 2-hydroxyethyl acrylate was prepared. Resin composition S was prepared by mixing 40 parts by mass of this urethane acrylate, 35 parts by mass of isobornyl acrylate, 24 parts by mass of epoxy acrylate which is an acrylic acid adduct of bisphenol A diglycidyl ether, 1 part by mass of Omnirad TPO H, and 1 part by mass of Omnirad 184.

[0074] [Resin Composition for Ribbon] Urethane acrylate A obtained by reacting bisphenol A-ethylene oxide adduct diol, tolylene diisocyanate, and hydroxyethyl acrylate, and urethane acrylate B obtained by reacting polytetramethylene glycol, tolylene diisocyanate, and hydroxyethyl acrylate were prepared. Resin composition R was prepared by mixing 18 parts by mass of urethane acrylate A, 10 parts by mass of urethane acrylate B, 15 parts by mass of tricyclodecane dimethanol diacrylate, 10 parts by mass of N-vinylpyrrolidone, 10 parts by mass of isobornyl acrylate, 5 parts by mass of bisphenol A-ethylene oxide adduct diol diacrylate, 0.7 parts by mass of 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino-propan-1-one (Omnirad 907), and 1.3 parts by mass of Omnirad TPO H.

[0075] [Fabrication of Optical Fiber] An optical fiber was fabricated by forming a 35 μm thick primary resin layer around a 125 μm diameter glass fiber using resin composition P, and then forming a 25 μm thick secondary resin layer around the primary resin layer using resin composition S. Next, the optical fiber was wound up, and then a 5 μm thick colored resin layer was formed around the secondary resin layer using the resin compositions of Test Examples 1 to 6 while the optical fiber was being re-wound using a coloring machine, thereby fabricating an optical fiber with a diameter of 255 μm and a colored resin layer (hereinafter referred to as "colored optical fiber"). The linear speed during the formation of each resin layer was 1500 m / min.

[0076] [Preparation of Optical Fiber Ribbon] Four colored optical fibers were prepared, coated with resin composition R for ribbon, and then cured by irradiation with ultraviolet light to form a connecting resin layer, thereby preparing an optical fiber ribbon.

[0077] (Color Peeling Test) After storing the optical fiber ribbon for 120 days in an environment (dark place) at 85°C and 85% RH, the optical fibers were separated from the optical fiber ribbon in accordance with Telcordia GR-20 5.3.1. The presence or absence of peeling of the colored resin layer was evaluated. The case where there was no peeling of the colored resin layer was evaluated as "A," the case where some of the ribbon resin remained in the colored resin layer was evaluated as "B," and the case where there was peeling of the colored resin layer was evaluated as "C."

[0078]

[0079] REFERENCE SIGNS LIST 1, 1A... optical fiber 10... glass fiber 12... core 14... cladding 20, 20A... coating resin layer 22... primary resin layer 24... secondary resin layer 26... colored resin layer 40... connecting resin layer 100... optical fiber ribbon

Claims

1. A glass fiber comprising a core and a cladding, A primary resin layer that is in contact with and covers the glass fiber, A secondary resin layer covering the primary resin layer, The secondary resin layer comprises a colored resin layer covering the aforementioned secondary resin layer, The colored resin layer comprises a cured product of a resin composition containing a photopolymerizable compound, a photopolymerization initiator, and surface-treated copper phthalocyanine particles. An optical fiber in which the content of the surface-treated copper phthalocyanine particles is 0.1% by mass or more and 10% by mass or less, based on the total amount of the resin composition.

2. A glass fiber comprising a core and a cladding, A primary resin layer that is in contact with and covers the glass fiber, The system comprises a secondary resin layer covering the primary resin layer, The secondary resin layer comprises a cured product of a resin composition containing a photopolymerizable compound, a photopolymerization initiator, and surface-treated copper phthalocyanine particles. An optical fiber in which the content of the surface-treated copper phthalocyanine particles is 0.1% by mass or more and 10% by mass or less, based on the total amount of the resin composition.

3. The optical fiber according to claim 1 or claim 2, wherein the surface-treated copper phthalocyanine particles have a surface treatment layer derived from a rosin compound containing at least one selected from the group consisting of abietic acid, dehydroabietic acid, and tetrahydroabietic acid.

4. The optical fiber according to claim 1 or claim 2, wherein the amount of the surface treatment layer in the surface-treated copper phthalocyanine particles is 1% by mass or more and 20% by mass or less.

5. The optical fiber according to claim 1 or claim 2, wherein the photopolymerizable compound comprises epoxy di(meth)acrylate.

6. An optical fiber ribbon comprising a plurality of optical fibers as described in claim 1, arranged in parallel and coated with a ribbon resin.

7. An optical fiber ribbon comprising a plurality of optical fibers as described in claim 2, arranged in parallel and coated with a ribbon resin.