JP2006030478A - Method and apparatus for manufacturing optical member with protective layer, and plastic optical fiber with protective layer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain a covered plastic optical fiber by forming a protective layer provided with flame retardancy on a plastic optical fiber. <P>SOLUTION: The plastic optical fiber (POF) 12 is sent out from a delivery reel 31 at constant velocity. The POF 12 is coated with a thermosetting urethane composition by means of a coater 32 to form a coated POF 33. A water tank 34 contains a liquid 35 regulated to 80°C and containing a flame retardant which is a phosphoric acid compound. The coated POF 33 is conveyed into the liquid 35, where the thermosetting urethane composition is cured to form the protective layer, whereby the covered plastic optical fiber 36 is obtained. The protective layer is provided with the flame retardant and the flame retardancy of the covered plastic optical fiber 36 is improved. The covered plastic optical fiber 36 is reeled by a take-up reel 43 after drying with a dryer 39. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

    The present invention relates to a manufacturing method and manufacturing apparatus for an optical member with a protective layer, and a plastic optical fiber with a protective layer, and more particularly to a manufacturing method and manufacturing apparatus for a plastic optical fiber with a protective layer, and a plastic optical fiber with a protective layer.

  Plastic optical members have advantages such as easy manufacture and processing and low cost compared to quartz optical members having the same structure. In recent years, optical fibers and optical lenses, Application to waveguides has been attempted. In particular, among these optical members, plastic optical fibers (hereinafter referred to as POF) are all made of plastic, and thus have a disadvantage that transmission loss is slightly larger than that of quartz, but good flexibility. It is lightweight and has good workability. Further, it has an advantage that it can be easily manufactured as an optical fiber having a large aperture and can be manufactured at a low cost. Accordingly, various studies have been made on optical communication transmitters for short distances where the magnitude of transmission loss does not become a problem (see, for example, Patent Document 1).

  POF is generally a core made of an organic compound having a polymer as a matrix (hereinafter referred to as a core or core part) and an organic compound having a refractive index different from that of the core part (generally having a low refractive index). And an outer shell (hereinafter referred to as a clad or a clad portion). In particular, a refractive index distribution type plastic optical fiber (hereinafter referred to as GI POF) having a core having a distribution of refractive index from the center to the outside increases the band of the optical signal to be transmitted. Therefore, it is attracting attention as an optical fiber having a high transmission capacity. One method for producing such a refractive index distribution type optical member is a method of producing an optical member base material (hereinafter referred to as a preform) using interfacial gel polymerization and then heating and stretching the preform. (For example, refer to Patent Document 2).

  The POF obtained by stretching the preform is used for high-speed communication over short distances as described above, and it is difficult to cause serious troubles due to sticking into the human body when broken, and easy to connect. While it has the advantages of vibration resistance and low cost, it has the property that the material itself is flammable. For this reason, it has been studied to impart flame retardancy to flammable POF, particularly when installed in a house, for home use or for in-vehicle use. In order not to impair the optical transmission performance of the POF, it is difficult to contain additives and the like in the POF. Therefore, it is very difficult to make POF itself flame-retardant as a method for imparting flame retardancy.

  On the other hand, for the purpose of improving the bending weather resistance of POF, suppressing the deterioration of performance due to moisture absorption, improving tensile strength, imparting stepping resistance, protecting from chemicals, and improving merchantability by coloring, one or more layers on the surface of POF It is widely used to provide a protective layer (coating layer) made of a thermoplastic resin. It has been studied to make POF flame retardant by imparting flame retardancy to this protective layer. Conventionally, halogen compounds and heavy metal compounds have been used as additives for making the protective layer flame-retardant. After such a thermoplastic resin is heated and melted, it is extruded from the nipple and covered so as to cover the POF surface (for example, see Patent Document 3).

JP 61-130904 A Japanese Patent No. 3333292 Japanese Patent Publication No.51-047628

  By the way, in melt coating of a thermoplastic resin, the resin must be heated until it is in a molten state, and damage (elongation due to heat, deformation, structural irregularities caused by them) occurs when the POF comes into contact with the hot molten resin. May become a big problem. For the POF core, flammable polymethyl methacrylate (PMMA) is usually used. For this reason, the flame-retardant coating layer is required to have higher flame-retardant performance than the coating layer such as copper wire or quartz optical fiber.

  Increasing the amount of flame retardant can increase flame retardancy. However, there is a problem that the viscosity of the resin before curing increases, making it difficult to push and apply from the nipple at high speed. Although it is necessary to increase the production efficiency as the production amount increases, there is a problem that it is difficult to increase the coating speed even though it can be extruded and coated at a low speed. In addition, it is difficult to keep the protective layer forming material to which these materials are added in a uniform state, and it tends to be non-uniform, which tends to cause deterioration in physical properties such as mechanical performance. For example, a plastic optical fiber core wire (also referred to as a plastic optical fiber cord, hereinafter referred to as an optical fiber core wire) or POF and / or optical fiber core wire, which is a POF having a protective layer formed by adding a large amount of flame retardant, is bundled. In addition, the bending softness of plastic optical fiber cables (hereinafter referred to as optical fiber cables) is lowered, and there is a problem that the mechanical performance and the commercial value are reduced.

  The present invention forms a protective layer having excellent flame retardancy when applying a protective layer to the optical member, and does not impair the mechanical properties of the optical member with the protective layer and has a protective layer with excellent optical properties. An object is to provide an optical member, a manufacturing method thereof, and a manufacturing apparatus.

  The manufacturing method of the optical member with a protective layer according to the first aspect of the present invention is a method for forming a protective layer on an optical member having a polymer as a main component, and manufacturing the optical member with a protective layer. Applying the material, transporting the optical member coated with the protective layer forming material into a liquid containing a flame retardant material, curing the protective layer forming material to form a protective layer and into the protective layer The flame retardant substance is added. According to a second aspect of the present invention, there is provided a method for producing an optical member with a protective layer, comprising: forming a protective layer on an optical member having a polymer as a main component, and producing the optical member with a protective layer; After coating the protective layer-forming material blended with the above, it is transported into the liquid, the protective layer-forming material is cured, the protective layer is formed on the optical member, and the flame-retardant substance is imparted to the protective layer Let According to a third aspect of the present invention, there is provided a method for producing an optical member with a protective layer, wherein a protective layer is formed on an optical member having a polymer as a main component, and the optical member with a protective layer is produced. After applying the protective layer forming material blended with the flammable substance, it is conveyed into a liquid containing the second flame retardant substance, and the protective layer forming material is cured to form a protective layer and the protective layer Add flame retardant material. The first flame retardant material and the second flame retardant material may be the same type or different types.

  The liquid for curing the protective layer is preferably adjusted to a temperature range of 45 ° C. or higher and 95 ° C. or lower. The liquid for curing the protective layer forming material is preferably a binder solution that forms a film on the surface of the protective layer. The liquid for curing the protective layer forming material is preferably a catalyst solution that accelerates the curing of the protective layer surface.

  It is preferable that the conveyance speed of the optical member is 3 m / min or more and 50 m / min or less. The protective layer-forming material is preferably composed mainly of a thermosetting urethane composition, and more preferably composed mainly of a thermosetting urethane composition having a room temperature and high viscosity. It is preferable that the flame retardant material includes at least one of an inorganic metal compound, a bromine compound, a phosphorus compound, and a silicone compound. The optical member is preferably a plastic optical fiber. It is preferable that the polymer contains at least polymethyl methacrylate.

  The manufacturing apparatus for an optical member with a protective layer according to the present invention forms a protective layer on an optical member having a polymer as a main component, and in the manufacturing apparatus with an optical member with a protective layer, a material for forming a protective layer is applied to the optical member. An application means for carrying out the treatment, a liquid tank containing a liquid for curing the protective layer forming material, and a conveying means for conveying the optical member coated with the protective layer forming material into the liquid tank. It is preferable that a flame retardant substance is contained in at least one of the protective layer forming material and the liquid, and the flame retardant substance is applied to the protective layer. The optical member is preferably a plastic optical fiber.

  The plastic optical fiber with a protective layer according to the present invention is a plastic optical fiber with a protective layer in which a protective layer is formed on an optical member mainly composed of a polymer. The protective layer is a thermosetting urethane composition having a highly viscous liquid at room temperature. Each of the terminally active isocyanate group-containing urethane prepolymers obtained by reacting a polyisocyanate compound with a compound having active hydrogen and an excess amount of a polyisocyanate compound alone or a mixture thereof, A polyurethane elastomer obtained by curing at a temperature of 150 ° C. or less, more preferably 100 ° C. or less, with a fine powder-coated amine whose surface is coated to render the amino group inactive as a main component.

  The method for producing an optical member with a protective layer according to the present invention comprises forming a protective layer on an optical member having a polymer as a main component, and applying the protective layer forming material to the optical member in the method for producing an optical member with a protective layer. Then, the optical member coated with the protective layer forming material is conveyed into a liquid containing a flame retardant substance, and the protective layer forming material is cured to form a protective layer and the flame retardant in the protective layer. Therefore, excellent flame retardancy can be imparted without impairing the mechanical strength of the protective layer. In addition, the optical member is formed without increasing the number of steps of the production of the optical member with a protective layer in order to form the flame retardant layer simultaneously with the formation of the protective layer or to impart a flame retardant function to the protective layer itself. It is possible to impart flame retardancy. In addition, the conventional thermoplastic resin has the above-mentioned problems in the blending of the flame retardant substance, but the thermosetting urethane composition desirable as the protective layer of the present invention is a room temperature high-viscosity liquid, Solid and liquid flame retardant materials can be blended as appropriate as long as the extrusion coating moldability is not impaired. Furthermore, when the optical member is a plastic optical fiber, it is possible to continuously manufacture a plastic optical fiber core wire having excellent mechanical strength and improved flame retardancy.

  According to the method for producing an optical member with a protective layer of the present invention, in the method for producing an optical member with a protective layer by forming a protective layer on an optical member having a polymer as a main component, the optical member has a flame retardant substance. After applying the protective layer forming material blended with the above, it is transported into the liquid, or after the protective layer forming material blended with the first flame retardant material is applied to the optical member, the second flame retardant material is coated. Since the protective layer forming material is cured to form the protective layer and the flame retardant is imparted to the protective layer, the material is excellent in difficulty without impairing the mechanical strength of the protective layer. The above-mentioned effects such as imparting flammability can be obtained.

(Core part)
As the polymerizable monomer for the raw material of the core part, it is preferable to select a raw material that can be easily bulk-polymerized. Examples of raw materials that are highly light transmissive and easy to bulk polymerize include, for example, the following (meth) acrylic acid esters (fluorine-free (meth) acrylic acid ester (a), fluorine-containing (meth) acrylic acid ester (b) ), Styrenic compounds (c), vinyl esters (d), etc., and the core part is a homopolymer of these, or a copolymer comprising two or more of these monomers, and a homopolymer and / or It can be formed from a mixture of copolymers. Among these, a composition containing (meth) acrylic acid esters as a polymerizable monomer can be preferably used. Of course, the present invention is not limited to these, and the types and composition ratios of the constituent monomers are set so that the refractive index of the polymer consisting of the monomer alone or the copolymer is equal to or higher than that of the clad portion. Is preferred.

  Furthermore, when the optical member to be produced is used for near-infrared light, absorption loss due to the C—H bond constituting it occurs, so the hydrogen atom of the C—H bond is replaced with deuterium atom or fluorine. Polymers (for example, deuterated polymethyl methacrylate (PMMA-d8), polytrifluoroethyl methacrylate (P3FMA), polyhexafluoroisopropyl-2-fluoroacrylate (HFIP) as described in Japanese Patent No. 3332922, etc.) 2-FA) and the like), the wavelength region that causes this transmission loss can be lengthened and the loss of transmission signal light can be reduced.

  When the polymer is polymerized from the monomer, a polymerization initiator is used. The polymerization initiator is appropriately selected according to the monomer used and the polymer to be polymerized. For example, benzoyl peroxide (BPO), t-butyl peroxy-2-ethyl hexanate (PBO), di-t-butyl peroxide (PBD), t-butyl peroxyisopropyl carbonate (PBI), n-butyl- Examples thereof include, but are not limited to, 4,4 (t-butylperoxy) valerate (PHV). Two or more kinds of polymerization initiators may be used in combination.

  A chain transfer agent (also referred to as a polymerization degree adjusting agent) can be used for the purpose of controlling the molecular weight and molecular weight distribution of the polymer. Examples of chain transfer agents include alkyl mercaptans (for example, n-butyl mercaptan, n-pentyl mercaptan, n-octyl mercaptan, n-lauryl mercaptan, tert-dodecyl mercaptan), thiophenols (for example, thiophenol, m- Bromothiophenol, p-bromothiophenol, m-toluenethiol, p-toluenethiol, etc.) are preferably used. In particular, alkyl mercaptans such as n-octyl mercaptan, n-lauryl mercaptan, and tert-dodecyl mercaptan are preferably used. Of course, the chain transfer agent is not limited to these. Two or more chain transfer agents may be used in combination.

  In order to increase the refractive index of the core part, a refractive index adjusting agent (hereinafter referred to as a dopant) may be added. The dopant has the property that the polymer containing it has a higher refractive index than the additive-free polymer. A material that has this property and can stably coexist with a polymer and is stable under polymerization conditions (such as heating and pressurization) is used. For example, benzyl benzoate (BEN), diphenyl sulfide (DPS), triphenyl phosphate (TPP), benzyl-n-butyl phthalate (BBP), diphenyl phthalate (DPP), diphenyl (DP), diphenylmethane (DPM) , Tricresyl phosphate (TCP), diphenyl sulfoxide, and the like, and BEN, DPS, TPP, and DPSO are particularly preferable.

  The dopant may be a polymerizable compound. When a dopant of the polymerizable compound is used, the copolymer containing this as a copolymerization component has a property of increasing the refractive index as compared with a polymer not containing the copolymer. Use what has. Examples of such a copolymer include MMA-BzMA copolymer.

(Clad part)
The clad portion uses a compound having a refractive index lower than the refractive index of the core portion and a refractive index lower than the refractive index of the core portion because the light transmitted through the core portion is totally reflected at the interface between them. Further, those having good adhesion to the core part, excellent toughness and excellent heat resistance are preferably used. Examples include acrylic resins polymerized from methyl methacrylate (MMA), deuterated methyl methacrylate, trifluoroethyl methacrylate, hexafluoroisopropyl-2-fluoroacrylate, and the like. Also, perfluoroalkyl methacrylate polymers, methacrylate esters A copolymer etc. are mentioned. In addition, also when polymerizing the polymer of a clad part from monomers, such as MMA, the said polymerization initiator and chain transfer agent used for formation of a core part can also be used.

  A fluororesin can also be used for the clad part. For example, polyvinylidene fluoride (PVDF: melting point 160 ° C. to 180 ° C.), polyvinyl fluoride (PVF: melting point 206 ° C.), polytetrafluoroethylene (PTFE: melting point 330 ° C.), tetrafluoroethylene-hexafluoropropylene copolymer (FEP) : Melting point 250 ° C. to 280 ° C.), tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PFA: melting point 300 ° C. to 310 ° C.), ethylene-tetrafluoroethylene copolymer (ETFE: melting point 260 ° C. to 270 ° C.), Examples thereof include polychlorotrifluoroethylene (PCTFE: melting point 210 ° C.), tetrafluoroethylene-hexafluoropropylene-perfluoroalkyl vinyl ether copolymer (EPE: melting point 290 ° C. to 300 ° C.), and the like.

  Furthermore, a vinylidene fluoride polymer can also be used. This includes a copolymer, such as a vinylidene fluoride-tetrafluoroethylene copolymer (preferably containing 50% by weight or more of vinylidene fluoride, more preferably containing 70% by weight or more and 90% by weight or less. ), A vinylidene fluoride-hexafluoropropylene copolymer, a vinylidene fluoride-hexafluoroacetone copolymer, a vinylidene fluoride-trifluoroethylene copolymer, a ternary copolymer of vinylidene fluoride, and the like. It is done.

  When the clad part is formed by melt extrusion, it is preferable that the melt viscosity is appropriate. About this melt viscosity, it is preferable that the average molecular weight, especially a weight average molecular weight are the range of 10,000-1 million as a physical property to correlate, More preferably, it is the range of 50,000-500,000.

  Additives may be added to the cladding part within a range that does not deteriorate the optical transmission performance. The additive can be easily contained in the polymer by polymerizing the polymer from the monomer after being added to the raw material monomer. Examples of the additive include a stabilizer that improves weather resistance and durability, and a stimulated emission functional compound for optical signal amplification that improves optical transmission performance. By adding the stimulated emission functional compound, the attenuated signal light can be amplified by the excitation light. This improves the transmission distance, so that it can be used as a fiber amplifier in a part of the optical transmission link. In addition, these additives can also be contained in a core part by adding to a monomer at the time of formation of a core part.

(Protective layer forming material)
As the material for forming the protective layer used in the present invention, a material that does not give thermal damage (for example, deformation, modification, thermal decomposition, etc.) to the POF which is an optical member is selected. Therefore, a material that can be reacted and cured at a glass transition temperature Tg (° C.) or lower and 50 ° C. or higher of the polymer that forms the POF core portion is used. The curing temperature is set to 50 ° C or higher. In general, a material that cures at a low temperature (particularly around room temperature) has a short pot life, and in the optical fiber core manufacturing process, it is continuously protected immediately after melt drawing. When the layer coating process is performed, curing starts with preheating brought in by the POF. For this reason, it is difficult to manage materials and set coating conditions. In consideration of these viewpoints, and when the glass transition temperature Tg (° C.) to be coated is 100 ° C. or higher, the lower limit of the curing temperature (Tg− 50) The temperature may be raised to ° C.

  It is preferable to use a molding time (time for curing the material) of 1 second or more, 10 minutes or less, preferably 3 minutes or less. Those having a long curing time are not preferable because POF is exposed to heating conditions. Furthermore, since the protective layer forming material retains fluidity for a long time, a material having a short curing time is preferable from the viewpoint of controlling the thickness. If the molding time is too short, there is a possibility that uneven curing occurs in the protective layer when a thick protective layer is formed.

  When the POF is formed from a plurality of chemical compositions such as a case where the content of the additive to which plasticity is imparted and the copolymerization ratio of the copolymer are distributed, the glass transition temperature of those chemical compositions Among them, the glass transition temperature at the lowest temperature is regarded as Tg (° C.). Further, when the polymer constituting the POF has no glass transition temperature Tg, the one having the lowest phase transition temperature (for example, melting point) is regarded as the Tg (° C.) of the present invention and controlled. In the present invention, an additive for imparting plasticity may be contained in the case of a single polymer (homopolymer). Also in this case, the lowest glass transition temperature having a distribution is regarded as Tg (° C.).

  By setting the curing temperature of the material for forming the protective layer to Tg (° C.) or lower and 50 ° C. or higher, thermal damage at the time of forming the protective layer is avoided, POF deformation due to thermal damage, deterioration of various physical property values, When the refractive index distribution type core portion is provided, deformation of the refractive index profile can be suppressed. Since performance degradation caused by this coating process can be suppressed, an optical member maintaining high performance can be provided. Depending on the type of the optical member and the protective layer forming material, the lower limit value of the curing temperature of the protective layer forming material can be set to (Tg-50) ° C.

  As the material for forming a protective layer of the present invention, a room temperature highly viscous liquid thermosetting urethane composition is preferably used. For example, the urethane composition which the compound which has an isocyanate group (NCO group), and the compound which has active hydrogen reacts and hardens | cures is mentioned. Since such a material proceeds by its own reactivity, it is not necessary to add a large amount of heat or light energy from the outside. Moreover, if the thickness of the coating is taken into consideration, reaction heat that is so great as to cause great damage to the optical member is not generated. Furthermore, the reaction proceeds by moisture as necessary, and heat does not necessarily need to be used for the reaction, but it is heated to a temperature not higher than Tg of the optical member and not lower than 45 ° C. and not higher than 100 ° C. In general, it is desirable to cure almost instantaneously. To specifically illustrate the above, terminal active NCO obtained by reacting an NCO group-containing polyisocyanate compound described in Japanese Patent No. 3131224 and a compound having active hydrogen with an excess amount of polyisocyanate compound. Each of the group-containing urethane prepolymers alone or a mixture thereof is coated with the surface of a polyamine which is solid at room temperature, and the amino group is made inert by fine powder. A one-component thermosetting urethane composition can be exemplified.

  In the composition comprising the polyisocyanate compound and the solid polyamine, a specific ratio of fine powder having a specific center particle size (excluding solid amine, the same applies hereinafter) on the surface of the solid polyamine having a melting point of 35 ° C. or more and a specific center particle size If the active amino group on the surface is coated, it can be easily dispersed in a terminally active NCO group-containing urethane prepolymer, which is a polyisocyanate compound, in a stable state to obtain excellent storage stability. Also during heat curing, the surface-coated solid polyamine compound generates active amino groups by heat melting. For example, immediate (fast) curing can occur at a temperature of 40 ° C. to 100 ° C. for about 10 minutes, and the polyisocyanate compound itself is used in place of or in combination with a terminally active NCO group-containing urethane prepolymer. You can also

  Specifically, in detail, the thermosetting urethane composition having a highly viscous liquid at room temperature has a terminal active NCO group obtained by reacting an excess amount of a polyisocyanate compound with (A) a polyisocyanate compound and a compound having active hydrogen. Each containing urethane prepolymer alone or a mixture thereof; and (B) a fine powder having a center particle size of 2 μm or less on the surface of a solid polyamine having a melting point of 35 ° C. or more and a center particle size of 20 μm or less. It is used as a main component of the thermosetting urethane composition, which is composed of fine powder coating amine which is fixed so that the weight ratio is 1 / 0.001 to 1.0 and is coated with active amino groups on the surface. is there.

  As the polyisocyanate compound, any of those belonging to aromatic, aliphatic or alicyclic may be used. For example, tolylene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), 3,3′-dimethyl-4, 4'-biphenylene diisocyanate, 1,4-phenylene diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, naphthylene diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, crude MDI, polymethylene polyphenyl isocyanate, isophorone diisocyanate, hexa Examples include methylene diisocyanate, hydrogenated xylylene diisocyanate, these isocyanurates, carbodiimides, burettes, etc., and one or a mixture of two or more of these may be used. To.

  An NCO group-containing urethane prepolymer (hereinafter referred to as a terminal NCO prepolymer) is obtained by adding an excess amount of a polyisocyanate compound to an ordinary active hydrogen-containing compound, for example, an OH / NCO equivalent ratio of 1 / 1.2-3.5. It can manufacture by making it react so that. If necessary, the reaction is carried out by using an appropriate reaction solvent (for example, ethyl acetate, toluene, xylene) and a reaction catalyst (for example, an organic tin-based catalyst such as dibutyltin dilaurate, a bismuth-based catalyst such as bismuth octylate, 1,4-diaza [2.2 .2] In the presence of a tertiary amine-based catalyst such as bicyclooctane), the reaction can usually be performed at room temperature to 60 to 90 ° C. for 1 to 7 hours. The terminal NCO-containing urethane prepolymer to be obtained is usually set to have a terminal NCO content of 0.5% to 25% (% by weight, the same applies hereinafter) and a viscosity of 500 cP to 500000 cP (20 ° C.). Examples of the compound having active hydrogen include polyhydric alcohols such as ethylene glycol, propylene glycol, glycerin, trimethylolpropane, pentaerythritol, sorbitol, and sucrose, and alkylene oxides such as propylene oxide and propylene oxide and ethylene oxide. Polyether polyols obtained by addition polymerization of ethylene glycol, propylene glycol and oligoglycols thereof; butylene glycol, hexylene glycol, polytetramethylene ether glycols; polycaprolactone polyols; polyester polyols such as polyethylene adipate; Polyols; higher fatty acid esters having a hydroxyl group such as castor oil; Polymer polyols, etc. grafted vinyl monomers Le polyols or polyester polyols and the like.

  Chain extenders can also be used in the preparation of the terminal active NCO group-containing urethane prepolymer. For example, it is a short-chain diol, and specific examples include ethylene glycol, diethylene glycol, triethylene glycol, propane diol, butane diol, neopentyl glycol, hexane diol, dipropylene glycol, and tripropylene glycol. A terminally active NCO group-containing urethane prepolymer using a chain extender can be prepared with tough physical properties.

  As the component (A) which is the polyisocyanate component, the above-described polyisocyanate compound itself, the terminal NCO-containing urethane prepolymer alone or a mixture of these is used.

  As the solid polyamine, any aromatic or aliphatic one having a melting point of 35 ° C. or higher may be used. For example, 4,4′-diaminodiphenylmethane, 2,4′-diaminodiphenylmethane, 3,3′-diamino Diphenylmethane, 3,4'-diaminodiphenylmethane, 2,2'-diaminobiphenyl, 2,4'-diaminobiphenyl, 3,3'-diaminobiphenyl, 2,4-diaminophenol, 2,5-diaminophenol, o- Fragrances such as phenylenediamine, m-phenylenediamine, 2,3-tolylenediamine, 2,4-tolylenediamine, 2,5-tolylenediamine, 2,6-tolylenediamine, 3,4-tolylenediamine Aliphatic groups such as 1,12-dodecanediamine, 1,10-decanediamine, 1,8-octanediamine, 1,14-tetradecanediamine, 1,16-hexadecanediamine, and the like. Species or a mixture of two or more may be provided for use. The solid amine is adjusted to have a center particle size of 20 μm or less, preferably 3 μm to 15 μm. When the center particle diameter exceeds 20 μm, the heat-cured polyurethane elastomer becomes incomplete reaction curing, and the desired physical properties tend not to be obtained.

  The fine powder-coated amine as the component (B) is prepared by pulverizing the solid polyamine to a predetermined center particle size range, and simultaneously adding the fine powder to the fine particle particle size range. Are mixed and pulverized to produce fine powder on the surface of the solid polyamine by a shear friction mixing method. In addition, a fine powder-coated amine can be produced by using a high-speed impact mixing stirrer or a compression shear mixing stirrer together with fine powder of a solid polyamine finely pulverized in advance. More preferably.

As said fine powder, it can use arbitrarily from inorganic type or organic type, For example, a titanium oxide, a calcium carbonate, clay, a silica, a zirconia, carbon, an alumina, a talc etc. are mentioned as an inorganic type. Moreover, polyvinyl chloride, a polyacrylic resin, polystyrene, polyethylene, etc. are mentioned as an organic type, These 1 type (s) or 2 or more types of mixtures are used for use. The amount used is selected so that the weight ratio between the solid polyamine and the fine powder is 1 / 0.001 to 1.0, preferably 1 / 0.002 to 0.5. When the ratio of the fine powder is less than 0.001, the effect of storage stability is not recognized, and when it exceeds 1.0, the storage stability is not further improved. By mixing and pulverizing the solid polyamine and fine powder in this way, static electricity is generated and the fine powder adheres to the surface of the solid polyamine, or the mechanical force of the mixing stirrer generates friction, impact, compression shear, etc. It is predicted that the fine powder adheres due to the local melting and sticking phenomenon of the solid amine due to the heat generated by the solid, or is physically thrown or embedded on the surface of the solid polyamine, or is chemically activated and fixed. (That is, the active amino group (NH ₂ ) on the surface of the solid polyamine is covered with the fine powder). It is important that the center particle size of the fixed fine powder is set to 2 μm or less, preferably 1 μm or less. If it exceeds 2 μm, it does not adhere to the surface of the solid polyamine.

Therefore, the blending ratio of both components (A) and (B) is usually selected so that the equivalent ratio of NH ₂ and NCO after heating activity is 1 / 0.5 to 2.0. A thermosetting urethane composition of room temperature and high viscosity used for a protective layer forming material of an optical member is composed of a system in which the above-mentioned polyisocyanate component (A) and fine powder coating amine (B) are blended. Accordingly, a proper amount of a bifunctional or higher functional epoxy resin may be added as the component (C) in order to impart physical properties of the cured product, particularly tough durability against compression set.

  Examples of the epoxy resin include bisphenol A type, F type, AD type, phenol type, cresol type, cycloaliphatic type, glycidyl ester type, glycidylamine type, and the like. Due to the addition of the epoxy resin (C), in addition to the reaction between the polyisocyanate component (A) and the solid polyamine, the reaction between the epoxy resin (C) and the solid polyamine occurs during the heat curing. Since it has a network structure, a cured product having the above-mentioned tough durability can be formed. The epoxy resin (C) is usually used in the range of 1 to 15 parts with respect to 100 parts (parts by weight, hereinafter the same) of the polyisocyanate component (A). If it is less than 1 part, the physical properties of the epoxy resin (C) cannot be expected, and if it exceeds 15 parts, the rubber physical properties of the polyurethane cured product are impaired. In addition, when the physical property of an epoxy resin (C) is desired, the said epoxy resin (C) can also be made rich.

  Further, if necessary, conventional additives such as urethane catalysts, solvents (for example, as polar solvents such as aliphatic hydrocarbons, aromatic hydrocarbons, alicyclic hydrocarbons, halogenated hydrocarbons, ethers) , Esters, ketones, etc., and aliphatic hydrocarbon solvents are particularly desirable), plasticizers (eg, dibutyl phthalate, dioctyl phthalate, dicyclohexyl phthalate, diisooctyl phthalate, diisodecyl phthalate, dibenzyl phthalate, butyl Benzyl phthalate, trioctyl phosphate, epoxy plasticizer, toluene-sulfonamide, chloroparaffin, adipic acid ester, castor oil, etc.) Filler (Organic and inorganic fillers such as polyethylene, polypropylene, acrylic resin, cellulose, polyester) Powders such as polystyrene, calcium carbonate, carbon black, talc, clay, silicon dioxide, silicate, alumina, glass balloons, plastic balloons, etc.), thixotropic agents, UV absorbers, anti-aging agents, dyes and pigments, adhesives, An appropriate amount of a dehydrating agent or the like may be blended.

  Examples of the urethane catalyst include DBU [1,8-diazabicyclo (5.4.0) undecene-7], DBU phenol salts, DBU octylates, DBU formates, and the like; monoamines (such as triethylamine), diamines ( N, N, N ′, N′-tetramethylethylenediamine etc.), triamine (tetramethylguanidine etc.), cyclic amine (triethylenediamine etc.), alcohol amine (dimethylaminomethanol etc.), ether amine [bis (2-dimethylamino Ethyl group such as ethyl) ether; organic metal carboxylate such as Sn series (dibutyltin dilaurate, tin octylate, etc.), Pb series (lead octylate, etc.), Zn series (zinc octylate, etc.); 2- Examples include imidazole series such as methylimidazole and 1,2-dimethylimidazole.

  The thermosetting urethane composition is three-dimensionally crosslinked to form a polyurethane elastomer (hereinafter referred to as a three-dimensional polyurethane). This can be obtained, for example, by reacting a compound having a plurality of NCO groups with a compound having active hydrogen. For example, the thermosetting urethane composition is held at 80 ° C. for 5 minutes. A three-dimensional polyurethane is obtained by three-dimensional reaction-curing polymerization with a polyamine having an activated terminal active NCO group in the thermosetting urethane composition. This method is advantageous in terms of cost because water or the like can be used as a heating medium.

  Three-dimensional polyurethane is a polyurethane-based elastomer and has the property of a rubber that deforms even at a small force at room temperature and returns almost to its original shape when the force is removed. Because it is soft and elastic, even if a force is applied, the original shape is maintained after the force is removed. For this reason, it has a function of relieving stress during work where pressure is applied from the outside, such as when a connector is attached. Thereby, it is suppressed that the pressure from the outside propagates to POF. Therefore, it is possible to suppress deterioration of optical characteristics due to deformation of POF, for example, transmission loss.

  The polyurethane-based elastomer can be obtained by thermosetting a thermosetting urethane composition. This polyurethane-based elastomer can be used up to 120 ° C. even when used for a long time. When used for a short time, it has heat resistance up to 130 ° C to 140 ° C. In addition, long-time use measures the stress-strain curve (SS curve) of a dumbbell sample after 200 hours or more and under predetermined temperature. When the dumbbell sample left in the room temperature environment for the same time is substantially the same as the SS curve, it is considered that it can be used at the predetermined temperature. Moreover, short-time use means that the leaving time is less than 100 hours. Further, in low density polyethylene (LDPE) conventionally used as a coating material, the upper limit usable temperature is 60 ° C to 75 ° C when used for a long time, and the upper limit is 80 ° C to 90 ° C even when used for a short time. It is possible temperature. It can be seen that the three-dimensional polyurethane is far less susceptible to thermal damage than the LDPE and has heat resistance.

(Flame retardant material)
In this invention, the liquid (henceforth a liquid) containing the flame-retardant substance by which temperature adjustment was carried out is put in the liquid tank mentioned later. As a result, the resin, which is a protective layer forming material on the POF surface, is cured and a flame retardant substance is imparted in the protective layer, so that the flame resistance of the optical fiber core wire passes through a special process or a plurality of protective layers. No flame retardant function can be imparted. Moreover, it is preferable to use water as the solvent of the liquid from the viewpoint of heat capacity. If the flame retardant material is water soluble, use an aqueous solution. When it is insoluble or hardly soluble in water, the liquid is prepared by emulsifying or dispersing. An organic solvent (for example, ethanol, ethylene glycol, glycerin, etc.) can be used as long as it does not cause modification of the polymer of the optical member (for example, POF) or the protective layer forming material. When using liquids using these solvents, they are preferably used below the boiling point of the solvent from the viewpoint of management, etc., and the present invention can be carried out at 95 ° C. or higher depending on the combination of the solvent and the flame retardant. It is. Furthermore, if the viscosity of the liquid is too high, excessive tension is applied to the optical fiber, which may cause a reduction in function. Therefore, it is preferable to suppress the viscosity low.

  Specific examples of the flame retardant material include organic compounds such as a halogen-containing compound containing bromine or chlorine, a phosphorus-containing compound, a polyphosphoric acid compound, or a nitrogen-containing compound. Alternatively, inorganic compounds such as metal hydroxides such as magnesium hydroxide and aluminum hydroxide can be used. Furthermore, for the purpose of improving the flame retardancy, it is preferable to contain a flame retardant aid in the liquid. Examples of the flame retardant aid include antimony trioxide, antimony pentoxide, zinc borate, barium metaborate, zirconium oxide, tin oxide hydrate and the like, and antimony trioxide is most preferably used in terms of cost. In addition, when it is difficult to impart a flame retardant substance to the protective layer forming material, it is preferable to add a binder that forms a film on the surface of the protective layer in the liquid. The binder is not particularly limited, and examples thereof include water-soluble resins such as polyvinyl alcohol (PVA) and sodium carboxymethyl cellulose, acrylic resin emulsions, and the like, when the protective layer is a polyurethane elastomer, from the viewpoint of affinity. PVA is preferably used. Furthermore, although the temperature dependency of the reaction curing of the thermosetting urethane composition is rate-determining, it can be made into a curing solution to which a catalyst is added in order to accelerate the curing of the thermosetting urethane composition. As such a catalyst, the above-mentioned tertiary amines, organic carboxylic acid metal salts, imidazoles and the like can be dissolved or dispersed in a liquid tank.

  Examples of the flame retardant material include bromine compounds (for example, ethylene bispentabromodiphenyl, hexabromobenzene, hexabromocyclododecane, ethylene bistetrabromophthalimide), chlorinated compounds (for example, chlorinated paraffin, bis ( Hexachlorocyclopentadieno) cyclooctane, 1,4,5,6,7,7-hexachlorobicyclo- (1,2,2) -5-heptene-2,3-dicarboxylic acid and the like. However, in recent years, the use of halogen-containing substances has been limited, and alternative phosphorus-containing compounds (for example, triethyl phosphate, trimethyl phosphate, trixylenyl phosphate), polyphosphate compounds (for example, polyphosphoric acid) Ammonium, melamine polyphosphate, etc.), nitrogen-containing compounds (for example, peroxidized 4-butylamino-2,2,6,6-tetramethylpiperidine and 2,4,6-trichloro-1,3,5-triazine) And a reaction product obtained by reacting cyclohexane with N, N′-ethane-1,2-diyl (bis1,3-propanediamine).

  The flame retardant substance or the flame retardant aid may be mixed in advance with the protective layer molding material. When the protective layer molding material is a thermosetting urethane composition and the flame retardant compound is used, it does not cause problems such as gelation by reacting with the NCO group which is the main component of the thermosetting urethane composition. Or in a range that does not cause problems. For example, the flame-retardant compound is used in an amount of 2 to 50% by weight, preferably 5 to 30% by weight in the thermosetting urethane composition.

  The blending method is not particularly limited. For example, the protective layer forming material may be blended after obtaining the protective layer forming material, or the raw material may be reacted after blending with any of the raw materials to obtain the protective layer forming material. Moreover, in this invention, a flame retardant substance can be made to give a flame retardance to a protective layer by mix | blending (containing) at least any one of the said liquid and the said protective layer formation material. Which is contained (contained) is appropriately selected according to the type of the protective layer forming material and the flame retardant used.

  In addition, when the thermosetting urethane composition is used for the protective layer molding material, the above-mentioned solvent and plasticizer are used as necessary, but the flame retardant function as a plasticizer to impart the flame retardant function. It is desirable to use one that can be added. In particular, as a plasticizer that imparts a flame retardant function, in addition to trioctyl phosphate, tricresyl phosphate, triphenyl phosphate, tri-2-ethylhexyl phosphate, tributoxyethyl phosphate, triisopropylphenyl phosphate, mono ( Alternatively, it is desirable to use a phosphate ester such as di) phenyl di (mono) isopropyl phosphate or resorcinol bisdiphenyl phosphate ester. Usually, the plasticizer is appropriately adjusted so as to be an elastomer desired as a flame retardant function and a protective layer. Usually, in a thermosetting urethane composition, it is more than 0 weight% and 50 weight% or less, Preferably it is set as the range of 5 weight%-30 weight%. In addition to the plasticizer having a flame retardant function, a chlorinated plasticizer such as chloroparaffin or a chlorinated solvent such as trichloroethylene can be used. However, there is a concern that the impact on the global environment may be concerned. It is desirable not to use it.

  As a flame retardant standard, UL (Underwriters Laboratories Inc.) has decided on several test methods. CMX (combustion test is generally referred to as VW-1 test) from the lowest flame retardant performance. Grades such as CM (vertical tray combustion test), CMR (riser test), and CMP (plenum test) are set. In the case of coating with POF, the plastic material is usually flammable. Therefore, in order to prevent the spread of fire in the event of a fire, it is preferably a cord or cable having the VW-1 standard.

(Preform manufacturing method)
In the SI type POF, when PMMA is used for the core part, it is preferable to use a fluororesin, particularly PVDF, for the clad part. This is because the difference in refractive index between PMMA in the core portion and PVDF in the cladding portion is a preferable range for an optical fiber. Moreover, since PVDF is excellent in mechanical strength, POF using it as a cladding is also excellent in mechanical strength. The production method of SI-type POF is preferably carried out by melt spinning. In the melt spinning method, PMMA serving as a core portion and PVDF serving as a cladding portion are discharged into respective holes from a composite spinning nozzle. Thereafter, PVDF is coated around PMMA with a nozzle and combined to obtain a preform.

  Next, a method for manufacturing GI POF will be described. First, a hollow cylindrical tube made of PMMA is prepared. In addition, this hollow cylindrical tube becomes a clad part. The hollow cylindrical tube may be manufactured by a known rotational polymerization method, or a commercially available pipe may be used. The hollow cylindrical tube is preferably bottomed because it is used as a polymerization vessel. Then, MMA and a dopant (for example, benzyl methacrylate) are put into the hollow tube, and interfacial gel polymerization is performed. In the hollow cylindrical tube, a polymer (PMMA) as a main component is formed, and a core portion whose refractive index continuously decreases from the center toward the outer periphery is formed, and a preform can be obtained.

  The molecular weight of the polymer obtained by polymerizing the polymer composition for forming the clad part, outer core part and inner core part is in the range of 10,000 to 1,000,000 in terms of weight average molecular weight because of stretching the preform. It is preferably 30,000 to 500,000. Further, the molecular weight distribution (MWD: weight average molecular weight / number average molecular weight) is also influenced from the viewpoint of stretchability. When MWD becomes large, it contains a component having an extremely high molecular weight. This is because if the amount of the component is too small, the stretchability is deteriorated, and in some cases, the stretch cannot be performed. Therefore, as a preferable range, MWD is 4 or less, and further preferably 3 or less.

(Production method of POF)
As shown in FIG. 1, the preform 10 is placed in a heating furnace 11. When the preform 10 is heated in the heating furnace 11, a part thereof is melted. In addition, although melting temperature is not specifically limited, It is preferable that it is the range of 180 to 270 degreeC. Drawing (stretching) is performed from the tip portion 10a of the melted portion as a starting point to obtain POF12. The POF 12 is cooled to a desired temperature (for example, 30 ° C. to 80 ° C.) by the cooling device 13 and passed through the wire diameter measuring device 14. Then, drawing is performed while a desired tension (for example, 0.3 MPa to 0.98 MPa (30 g to 100 g)) is applied by a drawing roller pair 17 including two rollers 15 and 16, and POF 12 is continuously obtained. In addition, the wire diameter of the POF is measured by the wire diameter measuring device 14, and the POF 12 is adjusted to have a desired diameter based on the measured value. The adjustment is performed by adjusting the arrangement position of the preform 10 in the heating furnace 11, the heating temperature, and the drawing speed by the drawing roller pair 17. The POF 12 is stored in a roll form (hereinafter referred to as a POF roll) after being wound on the take-up reel 18. The inside of the heating furnace 11 is preferably an inert atmosphere. Therefore, it is preferable to supply an inert gas into the heating furnace 11. The inert gas is not particularly limited, but nitrogen gas, helium gas, argon gas and the like are preferably used.

  FIG. 2 shows a coating means 30 according to the present invention. The POF roll is set on the delivery reel 31. The POF 12 is pulled out from the delivery reel 31. In the coating device 32, a protective layer forming material mainly composed of a thermosetting polyurethane composition is placed. When the POF 12 passes through the coating device 32, the protective layer forming material is applied. In the following description, this is referred to as a coated POF 33. For the application of the protective layer forming material, a resin pot type coating device or a coating device using an extrusion device used for coating an electric wire can be used.

  The liquid tank 34 contains a heated liquid 35. When the coated POF 33 passes through the liquid 35, the surface of the protective layer forming material of the optical member is cured to form the optical fiber core 36. The liquid 35 cures the protective layer forming material and imparts a flame retardant substance to the protective layer. Therefore, the temperature of the liquid 35 is preferably in the range of 10 ° C. or higher and 150 ° C. or lower, and more preferably in the range of 40 ° C. or higher and 100 ° C. or lower. More specifically, when a thermosetting urethane composition is used as the protective layer forming material, it is preferably in the range of 45 ° C. or higher and 95 ° C. or lower.

  The conveying speed of the coated POF 33 (including the case of the optical fiber core wire 36) is preferably in the range of 5 m / min to 100 m / min, and is preferably in the range of 10 m / min to 50 m / min. It is more preferable. If the conveyance speed is slower than 5 m / min, the productivity is inferior and the cost may increase. Moreover, when a conveyance speed exceeds 100 m / min, there exists a possibility that it may become difficult to acquire the effect of this invention which provides the flame retardance to a protective layer further, since the liquid 35 becomes difficult to apply | coat uniformly to a protective layer forming material. The optical fiber core wire 36 is conveyed by pulleys 37 and 38. The liquid 35 is dried by the drying device 39. A desired tension (for example, 0.5 MPa to 2.0 MPa (50 g to 200 g)) is applied to the optical fiber core wire 36 by a take-off roller pair 42 including two rollers 40 and 41 arranged to face the optical fiber core wire 36. Is taken over while being granted. Thereafter, the film is taken up on the take-up reel 43.

  A specific example of the optical member of the present invention is a plastic optical fiber (POF) 12. An optical fiber core wire 36 shown in FIG. 3 has a protective layer formed on this plastic optical fiber. In the present invention, the form is not particularly limited. Specifically, the outer diameter L1 of the POF 12 is preferably 200 μm or more and 1200 μm or less. The POF 12 is formed of a core portion 12a and a clad portion 12b. The thickness t1 of the cladding part is preferably in the range of 10 μm to 500 μm. In this case, the thickness L2 of the protective layer with flame retardant function (hereinafter referred to as protective layer) 50 is preferably 50 μm or more and 2000 μm or less, and more preferably 200 μm or more and 1500 μm or less. If the protective layer thickness L2 is less than 50 μm, the function of protecting the POF may not occur. In this case, the liquid 35 may permeate to the POF 12, which may deteriorate the optical characteristics of the POF 12. On the other hand, when the protective layer thickness L2 exceeds 2000 μm, the flexibility of the optical fiber core wire 36 is deteriorated and handling is deteriorated. Thereby, since the freedom degree of the wiring of the optical fiber core wire 36 deteriorates, there is a possibility that the value as a product may be reduced.

  In the optical member of the present invention, if necessary, the protective layer of the present invention may be used as a primary protective layer, and a secondary (or multilayer) protective layer may be further formed on the outer periphery. When the primary protective layer has a sufficient thickness, the thermal damage given to the POF is reduced, so that the limit of the curing temperature of the material can be made gentler than when directly covering the POF. As materials for forming a protective layer above the secondary protective layer, polyolefins such as low density polyethylene (LDPE) and polypropylene (PP), which are used as conventional coating materials in addition to the aforementioned materials, polyvinyl chloride ( PVC), various nylons, polyesters, ethylene vinyl acetate copolymers, EEA (ethylene-ethyl acrylate copolymer), and other thermoplastic resins. In coating, the resin is heated to a desired temperature and melted. When the heat of the molten resin is transmitted to the POF, transmission loss is deteriorated. In particular, when the core portion is made of GI type, when heated, the refractive index adjusting component added to impart a refractive index distribution may develop plasticity, in which case the glass transition temperature of the resin decreases. Therefore, deformation and flow easily occur, and the shape and refractive index distribution of the POF may be disturbed. However, if a polyurethane-based elastomer is used for the protective layer, the heat conductivity is low, so that the heat of the molten resin is suppressed from being transmitted to the POF. Thereby, the refractive index distribution is not disturbed by the POF shape, the core / cladding interface irregularity, and heat, and it is possible to prevent the transmission loss and the band from being deteriorated due to the coating process.

  Thus, by forming the three-dimensional polyurethane-based elastomer as a layer between the POF and the secondary protective layer (hereinafter also referred to as a primary protective layer), even when coating a resin having a high melting temperature, The POF is prevented from being thermally damaged. Thus, since heat conductivity is low while having heat resistance, the propagation of heat to the POF due to coating is reduced, so that damage due to heat can be reduced. Therefore, the three-dimensional polyurethane elastomer can be preferably used as the primary protective layer. Polyurethane is extremely excellent in sliding resistance. Therefore, even when rubbed with the thermoplastic resin forming the secondary protective layer, stress is suppressed from being applied to the POF due to its good sliding resistance. In this way, in order to increase the mechanical strength of the POF, a secondary protective layer is provided, and a side pressure transmitted from the secondary protective layer and stress relaxation when the POF is bent are performed by the primary protective layer. As a result, it is possible to suppress deterioration of optical characteristics due to unintended stress applied to the POF.

  Specific examples of the secondary protective layer include the following materials. Since these have high elasticity, they are also effective in terms of imparting mechanical properties such as bending. First, rubber that is one form of polymer can be used. For example, isoprene rubber (for example, natural rubber, isoprene rubber, etc.), butadiene rubber (for example, styrene-butadiene copolymer rubber, butadiene rubber, etc.), diene special rubber (for example, nitrile rubber, chloroprene rubber, etc.), olefin Examples of the rubber include ethylene-propylene rubber, acrylic rubber, butyl rubber, and halogenated butyl rubber, ether rubber, polysulfide rubber, and urethane rubber.

  Furthermore, a thermoplastic resin (TPE) for forming the secondary protective layer can also be used. Thermoplastic resins are a group of substances that exhibit rubber elasticity at room temperature, are plasticized at high temperatures, and are easy to mold. Specific examples include styrene TPE, olefin TPE, vinyl chloride TPE, urethane TPE, ester TPE, amide TPE, and the like. The above listed elastomers are not particularly limited as long as they can be molded at a temperature lower than the temperature at which the POF polymer is modified, and a copolymer or mixed polymer other than each material or other than the above compound group is used. You can also.

  As described above, a flame retardant, an ultraviolet absorber, an antioxidant, a radical scavenger, a light raising agent, a lubricant and the like may be introduced into the secondary protective layer. Examples of the flame retardant include halogen-containing resins such as bromine. Moreover, a metal hydroxide can be preferably used as a flame retardant from the viewpoint of stability such as reduction of toxic gases. The metal hydroxide has moisture as crystal water inside, and the attached water cannot be completely removed in the manufacturing process. Therefore, the flame retardant coating with the metal hydroxide is the outer layer of the primary protective layer. It is desirable to provide a moisture-resistant coating on the outer layer and further provide a protective layer on the outer layer.

  In order to provide a plurality of functions, a coating having various functions may be formed as a protective layer. For example, the flame retardant function of the protective layer can be improved by blending a flame retardant compound or a flame retardant aid in advance with the protective layer forming material of the optical member. In addition to the above-mentioned flame retardancy, a barrier layer for suppressing the moisture absorption of POF may be formed. Further, a moisture absorbing material for removing moisture, such as a moisture absorbing tape or a moisture absorbing gel, may be provided in the protective layer or between the protective layers. Further, a cushioning material such as a flexible material layer or a foamed layer for stress relaxation at the time of flexibility can be provided. Or it can select and provide according to uses, such as a reinforcement layer for raising rigidity. In addition to the resin, a fiber such as a fiber having a high elastic modulus (so-called tensile fiber) and / or a metal wire having high rigidity is blended in the protective layer forming material. By covering with the protective layer forming material, the mechanical strength of the obtained optical fiber cable can be reinforced. Examples of the tensile strength fiber include aramid fiber, polyester fiber, and polyamide fiber. Examples of the metal wire include stainless steel wire, zinc alloy wire, copper wire, and galvanized copper wire. In addition, any thing is not limited to what was mentioned above. In addition, a metal tube exterior for protection, an aerial support line, and a material for improving workability during wiring can be incorporated.

  In addition, depending on the form of use, the shape of the optical fiber cable is a collective cable in which POFs are concentrically arranged, an aspect called a tape core wire arranged in a row, and a collective cable in which they are gathered together with a presser winding or wrap sheath The form can be selected according to the application.

  The optical signal transmission system using the POF as the optical member of the present invention includes optical signal processing including optical components such as various light emitting elements and light receiving elements, optical switches, optical isolators, optical integrated circuits, and optical transceiver modules. It consists of devices. Moreover, you may combine with another optical fiber etc. as needed. Any known technique can be applied as a technique related to them. For example, the basic and actual of plastic optical fiber (published by NTS Corporation), Nikkei Electronics 2001.1.2.3, pp. 110-127 “Printed Wiring You can refer to "This time, optical components are mounted on the board." Combined with various technologies described in the above documents, internal wiring in computers and various digital devices, internal wiring in vehicles and ships, optical terminals and digital devices, optical links between digital devices, general households and housing complexes・ Suitable for optical transmission systems suitable for short distances such as high-speed, large-capacity data communications and control applications that are not affected by electromagnetic waves, including optical LANs in factories, offices, hospitals, schools, etc. Can be used.

  Furthermore, IEICE TRANS. ELECTRON., VOL. E84-C, No.3, MARCH 2001, p.339-344 “High-Uniformity StarCoupler Using Diffused Light Transmission”, Journal of Japan Institute of Electronics Packaging Vol.3, No.6, 2000 476 to 480 pages "Interconnection by optical sheet bus technology" and the light described in JP-A-10-123350, JP-A-2002-90571, JP-A-2001-290055, etc. Bus: described in JP-A-2001-74971, JP-A-2000-329962, JP-A-2001-74966, JP-A-2001-74968, JP-A-2001-318263, JP-A-2001-31840, etc. Optical branch coupler; optical star coupler described in Japanese Unexamined Patent Publication No. 2000-241655; Japanese Unexamined Patent Publication No. 2002-62457, Japanese Unexamined Patent Publication No. 2002-101044, Japanese Unexamined Patent Publication No. 20 Optical signal transmission device and optical data bus system described in each publication such as JP-A-305395; Optical signal processing apparatus described in JP-A-2002-23011; Optical signal cross-connect described in JP-A-2001-86537 System; optical transmission system described in JP-A-2002-26815; multi-function system described in JP-A-2001-339554, JP-A-2001-339555, etc .; and various optical waveguides, optical splitters, By combining with an optical coupler, optical multiplexer, optical demultiplexer, etc., a more advanced optical transmission system using multiplexed transmission / reception can be constructed. In addition to the above optical transmission applications, it can also be used in the fields of illumination, energy transmission, illumination, and sensors.

  Hereinafter, the present invention will be described more specifically with reference to Example 1 and Example 2. The types of materials, their proportions, operations and the like shown in the following examples can be appropriately changed without departing from the spirit of the present invention. Therefore, the scope of the present invention is not limited to the specific examples shown below. The description will be made in detail in Experiment 1 and Experiment 4, which are examples. Further, another embodiment according to the present invention will be described as Experiment 3. In Experiment 2 and Experiment 5, which are comparative examples, only different points from Experiment 1 and Experiment 4 will be described.

  An outer diameter 20 mm and a length of 60 cm preform (PVDF clad is a thermoplastic resin composition whose main component is PMMA) drawn by extrusion molding is stretched using a heating furnace having a maximum temperature of 280 ° C. 320 μm POF 12 was obtained. The transmission loss of POF12 at 650 nm was 157 dB / Km.

  From the liquid tank 34, 50 parts by weight of a flame retardant compound (Nikkafinon P-205 (phosphate compound) manufactured by Nikka Chemical Co., Ltd.), 5 parts by weight of polyvinyl alcohol, and 45 parts by weight of pure water A liquid 35 was added. The temperature of the liquid tank 34 is set to 80 ° C., and a thermosetting urethane composition (Penguin Foam # 3150 manufactured by Sunstar Giken Co., Ltd.) is applied with an applicator 32 with an outer diameter of about 1.2 mm. The tank 34 was passed at a feed rate of 5 m / min to cure the thermoplastic urethane composition and dried with a drying device 39 at 60 ° C. Furthermore, when the transmission loss of the optical fiber core wire 36 coated with this thermoplastic urethane composition as a protective layer was measured, it remained at 157 dB / Km, and there was no change. A UL flammability test (VW-1 flammability test based on UL1581) was performed on this optical fiber core wire 36. Passed the VW-1 grade. In addition, in the VW-1 flammability test based on UL1581, it is a test performed by the test piece shape originally defined. However, in the test of the optical fiber core wire 36, the shape was kept as the optical fiber core wire 36. In the following tests, tests were performed under the same conditions.

  In Experiment 2, the experiment was performed under the same conditions as Experiment 1 except that only pure water was added to the liquid tank 34. The transmission loss between the POF 12 and the optical fiber core 36 was the same value as in Experiment 1. However, a UL flammability test (VW-1 flammability test based on UL1581) was performed on the optical fiber core wire 36. The VW-1 grade was unacceptable.

  In Experiment 3, in place of the thermosetting urethane composition used in Experiment 1, a thermosetting urethane composition containing 30% resorcinol bisdiphenyl phosphate and 22% melamine polyphosphate as a flame retardant (RD manufactured by Sunstar Giken) -10336C), an optical member with a protective layer was prepared in the same manner as in Example 1 as an aqueous solution containing no flame retardant in the liquid tank 34, and used for the test. The UL flammability test passed the VW-1 grade.

  In Experiment 4, a clad pipe made of polyvinylidene fluoride (PVDF) having an outer diameter of 20 mm, an inner diameter of 19 mm (cladding wall thickness of 0.5 mm), and a length of 900 mm was used. This clad pipe was inserted into a sufficiently rigid polymerization vessel having an inner diameter of 20 mm and a length of 1000 mm. The polymerization vessel was washed with pure water together with the clad pipe and then dried at 90 ° C. Thereafter, one end of the clad pipe was sealed with a Teflon (registered trademark) stopper. After washing the inner wall of the clad pipe with ethanol, the pressure was reduced for 12 hours in a hot oven at 80 ° C. with the pressure (−0.08 MPa relative to atmospheric pressure).

  Next, an outer core polymerization process was performed. In an Erlenmeyer flask, 205.0 g of deuterated methyl methacrylate (MMA-d8 manufactured by Wako Pure Chemical Industries, Ltd.), 0.0512 g of 2,2′-azobis (isobutyric acid) dimethyl, 1-dodecanethiol (lauryl) Mercaptan) 0.766 g was weighed to prepare an outer core solution. This outer core solution was irradiated with ultrasonic waves for 10 minutes using an ultrasonic cleaning device USK-3 (38000 MHz, output 360 W) manufactured by Inoue Seieido Co., Ltd. Next, after the outer core liquid was poured into the clad pipe, the inside of the clad pipe was depressurized by 0.01 MPa with respect to atmospheric pressure using a vacuum filtration device. Ultrasonic treatment was performed for 5 minutes using the ultrasonic cleaning apparatus while degassing under reduced pressure.

  After replacing the air at the tip of the clad pipe with argon, the tip of the clad pipe was sealed with a silicon stopper and a seal tape. The clad pipe containing the outer core solution was placed in a 60 ° C. hot water bath and prepolymerized for 2 hours while shaking. Thereafter, the prepolymerized clad pipe is heated for 2 hours (rotational polymerization) while rotating at 500 rpm while maintaining a temperature of 60 ° C. in a horizontal state (a state in which the length direction of the clad pipe is horizontal). went. Thereafter, rotational polymerization was performed at a rotational speed of 3000 rpm at 60 ° C. for 16 hours, and further at 3000 rpm at 90 ° C. for 4 hours. A cylindrical tube having an outer core made of PMMA-d8 inside the clad pipe was obtained.

  Next, an inner core part preparation pretreatment was performed. The above-described clad pipe on which the outer core was formed was subjected to a pressure reduction treatment for 3 hours in a 90 ° C. heat oven at a pressure (−0.08 MPa with respect to atmospheric pressure). Furthermore, an inner core polymerization process was performed. In an Erlenmeyer flask, 82.0 g of deuterated methyl methacrylate (MMA-d8), 0.070 g of 2,2′-azobis (isobutyric acid) dimethyl, 0.306 g of 1-dodecanethiol, and diphenyl sulfide (DPS) as a dopant ) 6.00 g each was weighed to prepare an inner core solution. Thereafter, ultrasonic irradiation was performed for 10 minutes using an ultrasonic cleaning apparatus USK-3.

  After the clad pipe on which the outer core was formed was kept at 80 ° C. for 20 minutes, the inner core liquid was injected into the hollow portion. One end of the clad pipe was sealed with a Teflon (registered trademark) stopper. The rotating gel polymerization method was performed at 70 ° C. for 5 hours at a rotation speed of 3000 rpm. Thereafter, heat polymerization and heat treatment were further performed at 120 ° C. for 24 hours to form an inner core. Thereafter, it was taken out as a preform out of the autoclave.

  Using a heating furnace divided into 5 sections with a preform attached to an adapter (not shown), the temperature of the heater unit is adjusted so that the internal temperature is 215 ° C, 164 ° C, 144 ° C, 111 ° C, 60 ° C from the top. It was set. The preform was fed into the heating furnace at a constant speed of about 2 mm / min. When the tip of the preform fed into the heating furnace melted and dropped down into a filament shape, the drawing speed was 10 m / min to obtain a POF with an outer diameter of 300 μm of 500 m. The variation value of the internal temperature of the heater unit was ± 0.2 ° C. The obtained POF was measured with a laser beam having a wavelength of 650 nm and the POF transmission loss value was measured and found to be as good as 97 dB / km. A protective layer was formed on this POF using a thermosetting urethane composition under the same conditions as in Experiment 1 to obtain a plastic optical fiber core wire. The transmission loss value was 97 dB / km, and no deterioration occurred. The UL flammability test passed the VW-1 grade.

  In Experiment 5, the experiment was performed under the same conditions as Experiment 4 except that only pure water was added to the liquid tank 34. The transmission loss between the POF 12 and the optical fiber core 36 was the same value as in Experiment 4. However, a UL flammability test (VW-1 flammability test based on UL1581) was performed on the optical fiber core wire 36. The VW-1 grade was unacceptable.

It is the schematic of the extending | stretching apparatus containing a heating furnace. It is the schematic of the coating equipment for manufacturing the plastic optical fiber core wire which concerns on this invention. It is sectional drawing of the plastic optical fiber core wire which is an optical member with a protective layer concerning this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 12 Plastic optical fiber 30 Application | coating means 32 Coating apparatus 34 Liquid tank 35 Liquid 36 Plastic optical fiber core wire 50 Flame-resistant protective layer

Claims (15)

In the method of forming an optical member with a protective layer by forming a protective layer on an optical member mainly composed of a polymer,
Applying a protective layer forming material to the optical member,
Transporting the optical member coated with the protective layer forming material into a liquid containing a flame retardant substance,
A method for producing an optical member with a protective layer, comprising: curing the protective layer forming material to form a protective layer; and imparting the flame retardant substance to the protective layer. In the method of forming an optical member with a protective layer by forming a protective layer on an optical member mainly composed of a polymer,
After applying a protective layer forming material containing a flame retardant substance to the optical member, it is transported into the liquid,
The manufacturing method of the optical member with a protective layer characterized by making the said protective layer forming material harden | cure, forming the said protective layer in the said optical member, and giving the said flame-retardant substance to the said protective layer. In the method of forming an optical member with a protective layer by forming a protective layer on an optical member mainly composed of a polymer,
After applying the protective layer forming material containing the first flame retardant to the optical member, the optical member is conveyed into a liquid containing the second flame retardant,
A method for producing an optical member with a protective layer, comprising: curing the protective layer forming material to form a protective layer; and imparting the flame retardant substance to the protective layer.   The method for producing an optical member with a protective layer according to any one of claims 1 to 3, wherein the liquid for curing the protective layer is adjusted to a temperature range of 45 ° C or higher and 95 ° C or lower.   5. The method for producing an optical member with a protective layer according to claim 1, wherein the liquid for curing the protective layer forming material is a binder solution for forming a film on the surface of the protective layer.   6. The method for producing an optical member with a protective layer according to claim 1, wherein the liquid for curing the protective layer forming material is a catalyst solution that promotes curing of the surface of the protective layer.   The method for producing an optical member with a protective layer according to claim 1, wherein the conveyance speed of the optical member is 3 m / min or more and 50 m / min or less.   The method for producing an optical member with a protective layer according to any one of claims 1 to 7, wherein the protective layer-forming material contains a thermosetting urethane composition as a main component.   The method for producing an optical member with a protective layer according to any one of claims 1 to 8, wherein the flame retardant material includes at least one of an inorganic metal compound, a bromine compound, a phosphorus compound, and a silicone compound. .   The method for producing an optical member with a protective layer according to any one of claims 1 to 9, wherein the optical member is a plastic optical fiber.   The method for producing an optical member with a protective layer according to any one of claims 1 to 10, wherein the polymer contains at least polymethyl methacrylate. In a manufacturing apparatus for forming a protective layer on an optical member mainly composed of a polymer and forming an optical member with a protective layer,
Application means for applying a protective layer forming material to the optical member;
A liquid tank containing a liquid for curing the protective layer forming material;
Conveying means for conveying the optical member coated with the protective layer forming material into the liquid tank;
An apparatus for producing an optical member with a protective layer, comprising: A flame retardant is contained in at least one of the protective layer forming material and the liquid,
The said flame-retardant substance is provided to the said protective layer, The manufacturing apparatus of the optical member with a protective layer of Claim 13 characterized by the above-mentioned.   The said optical member is a plastic optical fiber, The manufacturing apparatus of the optical member with a protective layer of Claim 12 or 13 characterized by the above-mentioned. In a plastic optical fiber with a protective layer in which a protective layer is formed on an optical member mainly composed of a polymer,
The protective layer is formed from a thermosetting urethane composition having a highly viscous liquid at room temperature,
The thermosetting urethane composition is
Each of the terminally active isocyanate group-containing urethane prepolymers obtained by reacting a polyisocyanate compound with an excess amount of a polyisocyanate compound and a compound having active hydrogen, alone or a mixture thereof, coats the surface of a polyamine solid at room temperature. A plastic optical fiber with a protective layer, which is a polyurethane elastomer obtained by curing at a temperature of 150 ° C. or less with a fine powder coated amine having an amino group inactive as a main component.

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