Resin composition for coloring and coating optical fiber, optical fiber, and optical fiber ribbon

Abstract

The resin composition for coloring and coating an optical fiber contains a photopolymerizable compound, a polydimethylsiloxane compound, a photopolymerization initiator and titanium oxide, the photopolymerizable compound contains an epoxy di (meth) acrylate, and the content of the epoxy di (meth) acrylate is 100 parts by mass relative to the total amount of the photopolymerizable compound and the polydimethylsiloxane compound. The polydimethylsiloxane compound has a dimethyl siloxane unit and an alkylene oxide unit, and the molar ratio of the dimethyl siloxane unit with respect to the total amount of the dimethyl siloxane unit and the alkylene oxide unit is 12-80 mol%, inclusive.

Description

Technical Field

[0001] The present invention relates to a resin composition for coloring and coating optical fibers, optical fibers, and optical fiber ribbons.

[0002] This application claims priority based on Japanese Patent Application No. 2022-134777 filed on August 26, 2022, and cites all the contents described in the above Japanese Patent Application. Background Art

[0003] Generally, an optical fiber has a coating resin layer for protecting a glass fiber as a light transmission body. The coating resin layer includes, for example, a primary resin layer and a secondary resin layer. The outermost layer of the coating resin layer includes a colored resin layer for identifying the optical fiber (see, for example, Patent Documents 1 to 3).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Laid-Open No. 6-242355

[0007] Patent Document 2: Japanese Patent Application Publication No. 2003-279811

[0008] Patent Document 3: International Publication No. 2016 / 047002 Summary of the invention

[0009] A resin composition for coloring and coating an optical fiber according to one embodiment of the present disclosure contains a photopolymerizable compound, a polydimethylsiloxane compound, a photopolymerization initiator, and titanium oxide. The photopolymerizable compound includes epoxy di(meth)acrylate, and the content of epoxy di(meth)acrylate is 30 parts by mass or more and 75 parts by mass or less relative to 100 parts by mass of the total amount of the photopolymerizable compound and the polydimethylsiloxane compound. The polydimethylsiloxane compound has a dimethylsiloxane unit and an alkylene oxide unit, and the molar ratio of the dimethylsiloxane unit based on the total amount of the dimethylsiloxane unit and the alkylene oxide unit is 12 mol % or more and 80 mol % or less. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is a schematic cross-sectional view showing an example of the optical fiber according to the present embodiment.

[0011] Figure 2 It is a schematic cross-sectional view showing an example of the optical fiber according to the present embodiment.

[0012] Figure 3 It is a schematic cross-sectional view showing an example of the optical fiber ribbon according to the present embodiment. DETAILED DESCRIPTION

[0013] [Technical Problems to be Solved by the Present Disclosure]

[0014] The resin composition used to form the colored resin layer contains inorganic pigments such as titanium oxide. Since the specific gravity of the inorganic pigment is greater than that of the resin component, precipitation of the inorganic pigment may occur during the storage of the prepared resin composition. In addition, if the resin composition is not evenly applied when forming the colored resin layer, uneven coating diameter may occur, resulting in optical fiber breakage. Therefore, the resin composition used for optical fiber coloring and coating is not only required to have excellent storage stability, but also excellent coating properties.

[0015] An object of the present disclosure is to provide a resin composition for coloring and coating an optical fiber, an optical fiber, and an optical fiber ribbon having excellent storage stability and coating properties.

[0016] [Effects of the present disclosure]

[0017] According to the present disclosure, a resin composition for coloring and coating an optical fiber, an optical fiber, and an optical fiber ribbon having excellent storage stability and coating properties can be provided.

[0018] [Description of Embodiments of the Present Disclosure]

[0019] First, the contents of the embodiments of the present disclosure will be listed and described.

[0020] (1) A resin composition for coloring and coating an optical fiber according to one embodiment of the present disclosure comprises a photopolymerizable compound, a polydimethylsiloxane compound, a photopolymerization initiator, and titanium oxide, wherein the photopolymerizable compound comprises epoxy di(meth)acrylate, wherein the content of epoxy di(meth)acrylate is 30 parts by mass or more and 75 parts by mass or less relative to 100 parts by mass of the total amount of the photopolymerizable compound and the polydimethylsiloxane compound, and wherein the polydimethylsiloxane compound comprises a dimethylsiloxane unit and an alkylene oxide unit, and the molar ratio of the dimethylsiloxane unit based on the total amount of the dimethylsiloxane unit and the alkylene oxide unit is 12 mol % or more and 80 mol % or less.

[0021] Such a resin composition can achieve both storage stability and coating properties by specifying the content of epoxy di(meth)acrylate used as a photopolymerizable compound and containing a polydimethylsiloxane compound having a specific structure.

[0022] (2) In the above (1), from the viewpoint of further improving the storage stability of the resin composition, the polydimethylsiloxane compound may have a (meth)acryloyl group.

[0023] (3) In the above (1) or (2), from the viewpoint of further improving the coating properties of the resin composition, the viscosity of the resin composition according to the present embodiment may be 800 mPa·s or more and less than 10000 mPa·s at 25°C.

[0024] (4) In any of the above (1) to (3), from the viewpoint of adjusting the viscosity of the resin composition, the photopolymerizable compound may further include at least one selected from the group consisting of alkylene oxide-modified di(meth)acrylates and alkylene oxide-modified tri(meth)acrylates.

[0025] (5) An optical fiber according to one embodiment of the present disclosure comprises: a glass fiber including a core and a cladding, a primary resin layer that is in contact with the glass fiber and covers the glass fiber, a secondary resin layer that covers the primary resin layer, and a colored resin layer that covers the secondary resin layer, wherein the colored resin layer comprises a cured product of the resin composition described in any one of (1) to (4). By applying the resin composition according to this embodiment to the colored resin layer, an optical fiber that is less likely to be broken can be produced.

[0026] (6) An optical fiber according to one embodiment of the present disclosure comprises: a glass fiber including a core and a cladding, a primary resin layer connected to the glass fiber and covering the glass fiber, and a secondary resin layer covering the primary resin layer, wherein the secondary resin layer comprises a cured product of the resin composition described in any one of (1) to (4). By applying the resin composition according to this embodiment to the secondary resin layer, an optical fiber that is less likely to break can be produced.

[0027] (7) An optical fiber ribbon according to one embodiment of the present disclosure is formed by arranging a plurality of optical fibers described in (5) or (6) above in parallel and coating the plurality of optical fibers described in (5) or (6) above with a ribbon resin. Such an optical fiber ribbon does not cause coloring to flake off when removing the optical fibers, and the optical fibers can be easily identified.

[0028] [Details of the embodiments of the present disclosure]

[0029] Specific examples of the resin composition and optical fiber of the embodiments of the present disclosure are described with reference to the accompanying drawings as needed. Furthermore, the present disclosure is not limited to these examples, but is represented by the claims, and is intended to include all changes within the meaning and scope equivalent to the scope of the claims. In the following description, the same elements are marked with the same symbols in the description of the drawings and repeated descriptions are omitted. (Meth)acrylate in this specification refers to acrylate or its corresponding methacrylate. The same applies to other similar expressions such as (meth)acryloyl.

[0030] (Resin composition)

[0031] The resin composition for coloring and coating optical fiber involved in this embodiment contains a photopolymerizable compound, a polydimethylsiloxane compound, a photopolymerization initiator and titanium oxide, the photopolymerizable compound includes epoxy di(meth)acrylate, the content of epoxy di(meth)acrylate is 30 parts by mass or more and 75 parts by mass or less relative to 100 parts by mass of the total amount of the photopolymerizable compound and the polydimethylsiloxane compound, and the polydimethylsiloxane compound has a dimethylsiloxane unit and an alkylene oxide unit, and the molar ratio of the dimethylsiloxane unit based on the total amount of the dimethylsiloxane unit and the alkylene oxide unit is 12 mol% or more and 80 mol% or less.

[0032] The polydimethylsiloxane compound according to the present embodiment has a dimethylsiloxane unit (—Si(CH 3 ) 2 O—) including two methyl groups and an oxygen atom bonded to a silicon atom as a repeating unit in the main chain, and has an alkylene oxide unit in a side chain or at a terminal.

[0033] The amount of dimethylsiloxane units (hereinafter referred to as "DMS units") and alkylene oxide units (hereinafter referred to as "RO units") contained in the polydimethylsiloxane compound can be determined by measuring the 1 H NMR is calculated. Based on the viewpoint of further improving the storage stability of the resin composition, the molar ratio of the DMS unit can be 14 mol% or more, 16 mol% or more, 20 mol% or more, or 25 mol% or more when the total amount of the DMS unit and the RO unit is used as a reference. In addition, based on the viewpoint of further improving the compatibility with epoxy di(meth)acrylate, the molar ratio of the DMS unit can be 70 mol% or less, 60 mol% or less, 55 mol% or less, or 50 mol% or less when the total amount of the DMS unit and the RO unit is used as a reference.

[0034] As the alkylene oxide, ethylene oxide (EO) and propylene oxide (PO) may be mentioned.

[0035] Based on the viewpoint of further improving the storage stability of the resin composition, the polydimethylsiloxane compound may also have a (meth)acryloyl group. The polydimethylsiloxane compound may have a (meth)acryloyl group in the side chain or at the end. The (meth)acryloyl group may also be bonded to the alkylene oxide unit. The polydimethylsiloxane compound having a (meth)acryloyl group may be copolymerized with the photopolymerizable compound described below. In the present embodiment, the polydimethylsiloxane compound having a (meth)acryloyl group is not included in the photopolymerizable compound. The number of (meth)acryloyl groups possessed by the polydimethylsiloxane compound may be 1 or more or 2 or more, and may be 6 or less, 5 or less, or 4 or less. Based on the viewpoint of further improving the storage stability of the resin composition, the polydimethylsiloxane compound may have 1 or more and 6 or less (meth)acryloyl groups, and the molar ratio of the DMS unit may be 14 mol % or more and 70 mol % or less.

[0036] From the viewpoint of further improving the storage stability of the resin composition, the content of the polydimethylsiloxane compound may be 0.5 parts by mass or more, 1.0 parts by mass or more, 1.5 parts by mass or more, or 2.0 parts by mass or more, and may be 12.0 parts by mass or less, 10.0 parts by mass or less, 8.0 parts by mass or less, or 6.0 parts by mass or less, relative to 100 parts by mass of the total amount of the photopolymerizable compound and the polydimethylsiloxane compound.

[0037] The photopolymerizable compound of this embodiment is different from the polydimethylsiloxane compound having a (meth)acryloyl group in that it does not have a dimethylsiloxane skeleton. The photopolymerizable compound can improve the strength of the colored resin layer by including epoxy di(meth)acrylate. As 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.

[0038] Examples of the epoxy di(meth)acrylate 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.

[0039] The content of epoxy di(meth)acrylate may be 30 parts by mass or more, 35 parts by mass or more, 40 parts by mass or more, or 42 parts by mass or more, based on 100 parts by mass of the total amount of the photopolymerizable compound and the polydimethylsiloxane compound, from the viewpoint of improving the storage stability of the resin composition, and may be 75 parts by mass or less, 72 parts by mass or less, 70 parts by mass or less, or 69 parts by mass or less, from the viewpoint of improving the coating properties of the resin composition.

[0040] The photopolymerizable compound according to the present embodiment may further include a photopolymerizable compound (hereinafter referred to as a “monomer”) other than epoxy di(meth)acrylate.

[0041] As the monomer, a monofunctional monomer having one polymerizable group or a polyfunctional monomer having two or more polymerizable groups can be used. Two or more monomers may be mixed and used.

[0042] Examples of the monofunctional monomer include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, sec-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, Acrylate), 2-ethylhexyl (meth)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 (Meth)acrylate monomers such as ester, dicyclopentane (meth)acrylate, nonylphenol polyethylene glycol (meth)acrylate, nonylphenoxy polyethylene glycol (meth)acrylate, and isobornyl (meth)acrylate; (meth)acrylic acid, (meth)acrylic acid dimer, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, ω-carboxy-polycaprolactone (meth)acrylate and other carboxyl group-containing monomers; N-(meth)acryloylmorpholine, N-vinylpyrrolidone, N-vinylcaprolactam, N-(meth)acryloylpiperidine , N-(meth)acryloylpyrrolidine, (meth)acrylate 3-(3-pyridyl)propyl, cyclic trimethylolpropane formal acrylate and other heterocyclic monomers; maleimide monomers such as maleimide, N-cyclohexylmaleimide, and N-phenylmaleimide; (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- Amide monomers such as hydroxymethyl (meth)acrylamide and N-methylolpropane (meth)acrylamide; aminoalkyl (meth)acrylate monomers such as aminoethyl (meth)acrylate, aminopropyl (meth)acrylate, N,N-dimethylaminoethyl (meth)acrylate, and tert-butylaminoethyl (meth)acrylate; and succinimide monomers such as N-(meth)acryloyloxymethylenesuccinimide, N-(meth)acryloyl-6-oxyhexamethylenesuccinimide, and N-(meth)acryloyl-8-oxyoctamethylenesuccinimide.

[0043] Examples of the polyfunctional monomer 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, polyethylene glycol di(meth)acrylate, hydroxylated polyol di(meth)acrylate, and polyisocyanuric acid polyol di(meth)acrylate. 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-eicosandiol di(meth)acrylate, neopentyl glycol di(meth)acrylate trimethylolpropane tri(meth)acrylate, trimethyloloctane tri(meth)acrylate, trimethylolpropane polyethoxy tri(meth)acrylate, trimethylolpropane polypropoxy tri(meth)acrylate, trimethylolpropane polyethoxy polypropoxy tri(meth)acrylate, isocyanuric acid tris[(meth)acryloyloxyethyl] ester, pentaerythritol tri(meth)acrylate, pentaerythritol polyethoxy tetra(meth)acrylate, pentaerythritol polypropoxy tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate, di-trimethylolpropane tetra(meth)acrylate, dipentaerythritol tetra(meth)acrylate, dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, and caprolactone-modified isocyanuric acid tris[(meth)acryloyloxyethyl] ester.

[0044] From the viewpoint of adjusting the Young's modulus of the resin layer, the photopolymerizable compound involved in the present embodiment may also include a multifunctional monomer modified by an alkylene oxide. The multifunctional monomer modified by an alkylene oxide 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 may be represented as "(EO)n", and the propylene oxide chain may be represented as "(PO)n". n is an integer greater than 1, and may be greater than 2 or greater than 3, and may be less than 30, less than 25, or less than 20.

[0045] From the viewpoint of adjusting the viscosity of the resin composition, the photopolymerizable compound may further contain at least one selected from the group consisting of alkylene oxide-modified di(meth)acrylates and alkylene oxide-modified tri(meth)acrylates.

[0046] Examples of the alkylene oxide-modified di(meth)acrylate 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.

[0047] Examples of the alkylene oxide-modified tri(meth)acrylate include trimethylolpropane tri(meth)acrylate, trimethyloloctane tri(meth)acrylate, trimethylolpropane polyethoxy tri(meth)acrylate, trimethylolpropane polypropoxy tri(meth)acrylate, trimethylolpropane polyethoxy polypropoxy tri(meth)acrylate, trimethylolpropane polyethoxy polypropoxy tri(meth)acrylate, tris[(meth)acryloyloxyethyl] isocyanurate, and pentaerythritol tri(meth)acrylate.

[0048] The photopolymerization initiator can be appropriately selected from known free radical photopolymerization initiators and used. 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-methylpropane-1-one, bis(2,6-dimethoxybenzoyl)-2,4,4-trimethylpentylphosphine oxide, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinyl-propane-1-one (Omnirad 907, manufactured by IGM Resins), 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Omnirad TPO, manufactured by IGM Resins), and bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide (Omnirad 819, manufactured by IGM Resins).

[0049] The content of the photopolymerization initiator may be 1 to 10 parts by mass, 2 to 8 parts by mass, or 3 to 7 parts by mass, based on 100 parts by mass of the total amount of the photopolymerizable compound and the polydimethylsiloxane compound.

[0050] The resin composition may further contain a silane coupling agent, a leveling agent, a defoaming agent, an antioxidant, a sensitizer, and the like.

[0051] The silane coupling agent is not particularly limited as long as it does not hinder the curing of the resin composition. Examples of the silane coupling agent include tetramethyl silicate, tetraethyl silicate, mercaptopropyl trimethoxysilane, vinyl trichlorosilane, vinyl triethoxysilane, vinyl tri(β-methoxy-ethoxy)silane, β-(3,4-epoxycyclohexyl)-ethyl trimethoxysilane, dimethoxydimethylsilane, diethoxydimethylsilane, 3-acryloxypropyl trimethoxysilane, γ-glycidyloxypropyl trimethoxysilane, γ-glycidyloxypropyl methyl diethoxysilane, γ-methacryloxypropyl trimethoxysilane, N-(β-

[0043] The invention also includes bis-[3-(triethoxysilyl)propyl]tetrasulfide, bis-[3-(triethoxysilyl)propyl]disulfide, γ-trimethoxysilylpropyldimethylthiocarbamoyl tetrasulfide, and γ-trimethoxysilylpropylbenzothiazolyl tetrasulfide.

[0052] From the viewpoint of coloring the resin layer, the resin composition of the present embodiment may further contain titanium oxide particles. As titanium oxide particles, surface-treated titanium oxide particles may be used. Surface-treated titanium oxide particles are particles obtained by surface-treating titanium oxide using an inorganic substance, and have excellent dispersibility in the resin composition.

[0053] As inorganic substances used for surface treatment, for example, aluminum oxide, silicon dioxide, and zirconium dioxide can be cited. By providing the surface-treated titanium oxide particles with a surface treatment layer containing at least one selected from the group consisting of aluminum oxide, silicon dioxide, and zirconium dioxide, the dispersibility can be further improved. The surface treatment layer can be formed on at least a portion of the surface of the titanium oxide, or on the entire surface of the titanium oxide. The surface treatment layer is formed by surface treatment of the titanium oxide.

[0054] The amount of the surface treated layer in the surface treated titanium oxide particles may be 1% by mass or more, 1.5% by mass or more, or 2% by mass or more from the viewpoint of improving dispersibility, and may be 10% by mass or less, 9% by mass or less, or 8% by mass or less from the viewpoint of improving hiding power. The amount of the surface treated layer can be calculated by measuring the amount of titanium element and inorganic elements other than titanium contained in the surface treated titanium oxide particles using inductively coupled mass spectrometry (ICP-MS).

[0055] From the perspective of improving the lateral pressure resistance of the coating resin layer, the average primary particle size of the surface-treated titanium oxide particles may be 300 nm or less, 295 nm or less, or 290 nm or less. From the perspective of improving the hiding power, the average primary particle size of the surface-treated titanium oxide particles may be 100 nm or more, 150 nm or more, or 200 nm or more, and may be 200 nm or more and 300 nm or less. The average primary particle size may be measured, for example, by image analysis of electron microscope photographs, light scattering, BET (Brunauer-Emmett-Teller) method, or the like.

[0056] From the viewpoint of improving the visibility of the resin layer, the content of the surface-treated titanium oxide particles can be 0.6% by mass or more, 1% by mass or more, 2% by mass or more, or 3% by mass or more, based on the total amount of the resin composition as a reference. From the viewpoint of improving the curability of the resin composition, the content of the surface-treated titanium oxide particles can be 20% by mass or less, 15% by mass or less, 10% by mass or less, or 8% by mass or less, based on the total amount of the resin composition as a reference.

[0057] The viscosity of the resin composition of the present embodiment at 25° C. may be 800 mPa·s or more, 1000 mPa·s or more, 1500 mPa·s or more, or 2000 mPa·s or more from the viewpoint of further improving storage stability, and may be less than 10000 mPa·s, 9000 mPa·s or less, or 8500 mPa·s or less from the viewpoint of further improving coating properties.

[0058] If 900 mJ / cm 2 Above and 1100 mJ / cm 2 The following cumulative light intensity makes the elongation at break of the resin film obtained by curing the resin composition involved in this embodiment 6% or more and 50% or less at 23°C, and a resin layer with excellent toughness can be formed. The elongation at break of the resin film may be 6.5% or more, 7% or more, or 10% or more, and may be 45% or less, 40% or less, or 30% or less.

[0059] From the perspective of improving the single core separation property of the optical fiber, the Young's modulus of the resin film at 23° C. may be 500 MPa or more, 600 MPa or more, or 700 MPa or more. From the perspective of forming a resin layer with excellent toughness, the Young's modulus of the resin film at 23° C. may be 1600 MPa or less, 1500 MPa or less, or 1450 MPa or less.

[0060] The resin composition according to the present embodiment can be suitably used as a colored coating material for an optical fiber. By forming the outermost layer of the coating resin layer using the colored coating material including the resin composition according to the present embodiment, the single core separation property of the optical fiber can be improved.

[0061] (optical fiber)

[0062] Figure 1 1 is a schematic cross-sectional view showing the structure of an optical fiber according to one embodiment. Figure 1 As shown, the optical fiber 1 includes a glass fiber 10 and a coating resin layer 20 that is in contact with the glass fiber 10 and covers the outer circumference of the glass fiber 10 .

[0063] The glass fiber 10 is a light-guiding optical transmission body that transmits the light introduced into the optical fiber 1. The glass fiber 10 is a glass member, for example, composed of silica (SiO2) glass as a base material (main component). The glass fiber 10 includes a core 12 and a cladding 14 covering the core 12. The glass fiber 10 transmits the light introduced into the optical fiber 1. The core 12 is, for example, arranged in a region including the central axis of the glass fiber 10. The core 12 is, for example, composed of pure SiO2 glass, or glass containing GeO2 and / or fluorine elements in SiO2 glass. The cladding 14 is arranged in a region surrounding the core 12. The cladding 14 has a refractive index lower than the refractive index of the core 12. The cladding 14 is, for example, composed of pure SiO2 glass, or SiO2 glass to which fluorine elements are added. The outer diameter of the glass fiber 10 is about 100 μm to 125 μm, and the diameter of the core 12 constituting the glass fiber 10 is about 7 μm to 15 μm.

[0064] The coating resin layer 20 is an ultraviolet curing resin layer covering the coating layer 14. The coating resin layer 20 includes: a primary resin layer 22 covering the outer periphery of the glass fiber 10, and a secondary resin layer 24 covering the outer periphery of the primary resin layer 22. The primary resin layer 22 is in contact with the outer peripheral surface of the coating layer 14 and covers the entire coating layer 14. The secondary resin layer 24 is in contact with the outer peripheral surface of the primary resin layer 22 and covers the entire primary resin layer 22. The thickness of the primary resin layer 22 is, for example, not less than 10 μm and not more than 50 μm. The thickness of the secondary resin layer 24 is, for example, not less than 10 μm and not more than 40 μm.

[0065] The resin composition of this embodiment can be applied to the secondary resin layer 24. The secondary resin layer 24 can be formed by curing the resin composition. By making the secondary resin layer 24 contain the cured product of the resin composition of this embodiment, the single core separation property of the optical fiber can be improved.

[0066] The covering resin layer 20 may further include a colored resin layer 26 covering the outer periphery of the secondary resin layer 24 . Figure 21 is a schematic cross-sectional view showing the structure of an optical fiber according to one embodiment. Figure 2 As shown, the optical fiber 1A according to the present embodiment includes: a glass fiber 10, and a coating resin layer 20 that is connected to the glass fiber 10 and covers the outer periphery of the glass fiber 10. The coating resin layer 20 includes a primary resin layer 22, a secondary resin layer 24, and a colored resin layer 26. The thickness of the colored resin layer 26 is, for example, not less than 3 μm and not more than 10 μm.

[0067] The resin composition involved in this embodiment can be applied to the colored resin layer 26. The colored resin layer 26 can be formed by curing the above-mentioned resin composition. The colored resin layer 26 can improve the single core separation property of the optical fiber by including a cured product of the resin composition involved in this embodiment. The secondary resin layer 24 in the optical fiber 1A can be formed using a conventionally known resin composition, for example, by curing a resin composition containing urethane (meth) acrylate, a monomer, and a photopolymerization initiator.

[0068] The primary resin layer 22 can be formed, for example, by curing a resin composition containing urethane (meth)acrylate, a monomer, a photopolymerization initiator, and a silane coupling agent. A conventionally known technique can be used for the resin composition for the primary resin layer.

[0069] (Fiber Optic Ribbon)

[0070] The optical fiber according to this embodiment can be used to produce an optical fiber ribbon. The optical fiber ribbon is formed by arranging a plurality of the above optical fibers in parallel and coating the plurality of the above optical fibers with a ribbon resin.

[0071] Figure 3 1 is a schematic cross-sectional view showing an optical fiber ribbon according to the present embodiment. The optical fiber ribbon 100 includes a plurality of optical fibers 1A and a connecting resin layer 40 that covers and connects the optical fibers 1A with a ribbon resin. Figure 3 Although four optical fibers are shown as an example, the number is not particularly limited.

[0072] As the tape resin, a resin material commonly known as a tape material can be used. Based on the viewpoints of damage resistance and easy cutting of the optical fiber, the tape resin can also 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.

[0073] The optical fiber ribbon according to the present embodiment uses the above optical fibers, and when the connecting resin layer is removed from the optical fiber ribbon to take out the optical fibers, no color peeling occurs, and the optical fibers can be easily identified.

[0074] Example

[0075] Hereinafter, the results of evaluation tests using the examples and comparative examples according to the present disclosure will be shown to further explain the present disclosure in detail. In addition, the present invention is not limited to these examples.

[0076] [Resin composition for colored resin layer]

[0077] (Polydimethylsiloxane compounds)

[0078] The polydimethylsiloxane compounds shown in Table 1 were prepared. The molar ratio of the DMS unit in the polydimethylsiloxane compound (DMS unit / (DMS unit+RO unit)) was used to measure the molecular weight of the polydimethylsiloxane compound. 1 H NMR is calculated based on the ratio of hydrogen atoms in the DMS unit to hydrogen atoms in the RO unit. 1 H NMR measurement conditions.

[0079] Measurement device: Fourier transform nuclear magnetic resonance device ("Ascend500 + AVANCE III HD" manufactured by Bruker BioSpin)

[0080] Probe: 5 mm BBFO BB / 19F-1H / D probe

[0081] Determination solvent: deuterated chloroform

[0082] Sample concentration: 20% (mL / mL)

[0083] Determination of nuclear species: 1H

[0084] Determination method: 1D

[0085] Total times: 128 times

[0086] [Table 1]

[0087]

[0088] (Photopolymerizable compound)

[0089] Prepare bisphenol A epoxy diacrylate (EA), polypropylene glycol diacrylate (PPGDA), EO-modified trimethylolpropane triacrylate (TMP(EO)3TA), EO-modified bisphenol A diacrylate (BPA(EO) 30 DA) as a photopolymerizable compound.

[0090] 2,4,6-Trimethylbenzoyldiphenylphosphine oxide (Omnirad TPO) and 1-hydroxycyclohexylphenyl ketone (Omnirad 184) were prepared as photopolymerization initiators.

[0091] Surface-treated titanium oxide particles having a surface-treated layer containing aluminum oxide (Al2O3) were prepared as titanium oxide particles. The surface-treated titanium oxide particles had an average primary particle size of 200 to 300 nm, and the amount of Al2O3 calculated by ICP-MS measurement was 2.5 mass %.

[0092] The resin composition was prepared by mixing the polydimethylsiloxane compound, the photopolymerizable compound, and the photopolymerization initiator in the amounts (parts by mass) shown in Table 2 or Table 3, and then mixing so that the content of the surface-treated titanium oxide particles in the resin composition was 5% by mass. Test Examples 1 to 11 correspond to Examples, and Test Examples 12 to 15 correspond to Comparative Examples.

[0093] (Viscosity)

[0094] The rheometer (MCR-102 manufactured by Anton Paar) was used with a cone-plate CP25-2 and a shear rate of 10 s -1 The viscosity of the resin composition at 25°C was measured under the conditions of.

[0095] (Storage stability)

[0096] After the resin composition was prepared, it was stored in a thermostatic chamber at 30° C. The case where the appearance of the resin composition did not change after 30 days was evaluated as “A”, the case where the resin composition had phase separation such as precipitation within 15 days was evaluated as “B”, and the case where the resin composition had phase separation such as precipitation within 7 days was evaluated as “C”.

[0097] (Young's modulus)

[0098] The resin composition was applied onto a polyethylene terephthalate (PET) film using a spin coater, and then an electrodeless UV (Ultraviolet) lamp system ("VPS600 (D-bulb)" manufactured by Heraeus) was used at 1000±100 mJ / cm 2 The resin layer was cured under the conditions of , thereby forming a resin layer with a thickness of 50±5 μm on the PET film. The resin layer was peeled off from the PET film to obtain a resin film.

[0099] The resin film was punched into a dumbbell shape of JIS K 7127 No. 5 type, and stretched using a tensile tester at a tension rate of 1 mm / min and a line spacing of 25 mm under the conditions of 23±2°C and 50±10%RH to obtain a stress-strain curve. The Young's modulus was determined using the 2.5% secant line.

[0100] (Resin composition for primary resin layer)

[0101] A urethane acrylate oligomer obtained by reacting polypropylene glycol having a molecular weight of 4000, isophorone diisocyanate, hydroxyethyl acrylate and methanol was prepared. 75 parts by mass of the urethane acrylate oligomer, 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, and 1 part by mass of 3-mercaptopropyltrimethoxysilane were mixed to prepare a resin composition P.

[0102] (Resin composition for secondary resin layer)

[0103] Resin composition S was prepared by mixing 40 parts by mass of urethane acrylate oligomer which was a reaction product of polypropylene glycol having a molecular weight of 600, 2,4-toluene diisocyanate and 2-hydroxyethyl acrylate, 35 parts by mass of isobornyl acrylate, 24 parts by mass of epoxy acrylate which was an acrylic acid adduct of bisphenol A diglycidyl ether, 1 part by mass of Omnirad TPO, and 1 part by mass of Omnirad 184.

[0104] [Fabrication of optical fiber]

[0105] A primary resin layer with a thickness of 17.5 μm was formed on the periphery of a glass fiber with a diameter of 125 μm composed of a core and a cladding, and a secondary resin layer with a thickness of 15 μm was formed on the periphery using a resin composition S to produce an optical fiber. Subsequently, after the optical fiber was temporarily wound up, a coloring machine was used to rewind the optical fiber while forming a colored resin layer with a thickness of 5 μm on the periphery of the secondary resin layer using the resin composition of Test Examples 1 to 7, thereby producing an optical fiber with a diameter of 200 μm having a colored resin layer (hereinafter referred to as a "colored optical fiber"). The line speed when forming each resin layer was set to 1500 m / min.

[0106] (Coating properties)

[0107] The coating property of the resin composition was evaluated by checking whether the optical fiber was broken or not. The case where the optical fiber was not broken was evaluated as "OK", and the case where the optical fiber was broken was evaluated as "NG".

[0108] [Table 2]

[0109]

[0110] [Table 3]

[0111]

[0112] Description of Reference Numerals

[0113] 1.1A optical fiber

[0114] 10. Fiberglass

[0115] 12 core

[0116] 14 cladding

[0117] 20 coating resin layer

[0118] 22 primary resin layer

[0119] 24 Secondary resin layer

[0120] 26 Colored resin layer

[0121] 40 bonding resin layer

[0122] 100 fiber optic ribbon.

Claims

1. A resin composition for coloring and coating an optical fiber, comprising a photopolymerizable compound, a polydimethylsiloxane compound, a photopolymerization initiator and titanium oxide, The photopolymerizable compound includes epoxy di(meth)acrylate, The content of the epoxy di(meth)acrylate is 30 parts by mass or more and 75 parts by mass or less relative to 100 parts by mass of the total amount of the photopolymerizable compound and the polydimethylsiloxane compound, and The polydimethylsiloxane compound includes a dimethylsiloxane unit and an alkylene oxide unit, and a molar ratio of the dimethylsiloxane unit based on the total amount of the dimethylsiloxane unit and the alkylene oxide unit is 12 mol % or more and 80 mol % or less.

2. The resin composition according to claim 1, wherein The polydimethylsiloxane compound has a (meth)acryloyl group. 3 . The resin composition according to claim 1 , wherein the viscosity of the resin composition is 800 mPa·s or more and less than 10000 mPa·s at 25° C.

4. The resin composition according to any one of claims 1 to 3, wherein The photopolymerizable compound further includes at least one selected from the group consisting of alkylene oxide-modified di(meth)acrylates and alkylene oxide-modified tri(meth)acrylates.

5. An optical fiber having: Glass fiber comprising a core and a cladding; a primary resin layer connected to the glass fiber and covering the glass fiber; a secondary resin layer covering the primary resin layer; and a colored resin layer covering the secondary resin layer, and The colored resin layer comprises a cured product of the resin composition according to any one of claims 1 to 4.

6. An optical fiber having: Glass fiber comprising a core and a cladding; a primary resin layer that is in contact with the glass fiber and covers the glass fiber; and a secondary resin layer covering the primary resin layer, and The secondary resin layer comprises a cured product of the resin composition according to any one of claims 1 to 4.

7. An optical fiber ribbon, comprising a plurality of optical fibers according to claim 5 arranged in parallel and coated with a ribbon resin.

8. An optical fiber ribbon, comprising a plurality of optical fibers according to claim 6 arranged in parallel and coated with a ribbon resin.

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