MXPA98000938A - Improved separability of tape through the use of revestimie additives - Google Patents

Abstract

The present invention relates to a fiber optic tape, the fiber optic tape includes a plurality of substantially coplanar coated optical fibers and a ribbon matrix material which holds the plurality of optical fibers coated in alignment includes a glass core, a coating layer surrounding and adjacent to the glass core, and a primary polymeric coating material, preferably containing a silicone, surrounding and adjacent to the coating layer, the primary polymeric coating material is adhered to the coating layer to form a layer interface Coating-primary polymeric coating material, after applying a longitudinal separation force at the interface of coating layer-primary polymeric coating material, the matrix material of the tape and the primary polymeric coating material are substantially removed from the Reagent material layer Primary polymeric clothing with a thickness of less than about 5æm remains in the coating layer, these fiber optic tapes exhibit improved separation properties without sacrificing the adhesion of the primary coating material, and are well adapted to be joined by fusion bonding techniques of ma

Description

IMPROVED SEPARABILITY OF TAPE THROUGH THE USE OF COATING ADDITIVES FIELD OF THE INVENTION The present invention relates generally to fiber optic tapes and, more particularly, to fiber optic tapes having improved separation capability.

BACKGROUND OF THE INVENTION Now fiber optic has largely replaced copper conductors in long-line telecommunications cable and is also widely used for data transmission. Expanded use of optical fibers in local circuit telephone and cable television service is expected, as local fiber networks are established to send even larger volumes of information, in the form of data, audio and video signals to residential users. and commercial. In addition, the use of optical fibers in the home and in business for internal data, voice and video communications has begun and is expected to increase. One of the main disadvantages of the use of optical fibers is the difficulty in achieving end-to-end separation with loss of acceptable light transmission. For a good connection, you can align the two fibers with a lot of precision Now, this requires a high level of experience by the installer, as well as more time and more expensive tools with respect to facilities that use metallic conductors. In addition, this problem, although it is important in long-line transmission fibers, improves when fiber is used in local applications, where the er of separations per installed fiber unit length increases greatly. Fiber optic tapes provide a modular design that simplifies the construction, installation and maintenance of fiber optic cable eliminating the need to handle individual fibers. A fiber optic ribbon of a plurality of optical waveguides is constructed, each of which is typically coated with one or more polymer coatings that serve to protect and cushion the waveguide. The plurality of coated waveguides, each of which is often referred to as an optical fiber, is held in a coplanar arrangement by a ribbon matrix material that joins the individual optical fibers together or surrounds the plurality of optical fibers. in a common external cover or protection. The use of fiber optic tapes promises to reduce the labor and cost involved in the separation of individual optical fibers, since the optical fibers in the tape can be separated by connecting the much longer tape, as long as the positions of the optical fibers can be fixed with precision and stay. In a commonly used method for separating tapes, known as mass melt separation, the first step involves the complete removal of all protective polymer coatings and tape matrix material. The procedure depends on a block V to align the individual fibers. The V block controls the angular alignment particularly well as long as the optical waveguide is free of any protrusions, such as residual of non-uniform primary coating material, in the region where the optical waveguide makes contact with the V block. In addition, block V allows precise alignment of the two ends of the optical waveguide as long as the residual primary coating material at both ends has the same thickness. Accordingly, the alignment of the two optical waveguides and the success of mass melt separation depend on the removal of the protective coatings. In fact, if the coating materials can not be separated cleanly and easily, separation operations will be seriously impeded by the use of block V and other similar devices. The need to completely remove the primary coating from the optical waveguide must be balanced with the paper coating to protect the fiber waveguide from mechanical stress, moisture infiltration, to which the silica material of which the Optical waveguide is typically constructed, and other hazards environmental The protection of the optical waveguide from these hazards will probably be an increased concern, especially as the use of optical fibers in local data transmission, audio and video grows. In contrast to the comparatively tight conditions in long-distance cables, where the exposure points of the fiber are much smaller and more protected, local optical fibers, which have a much larger number of separations, are more likely to attack from a variety of environmental hazards. For example, fiber optic connections are commonly made on neighboring pedestals, which are often not sealed, giving access to insects and animals in the optical fiber and exposing the optical fiber to moisture and water. In addition, a substantial percentage of fiber optic cables will find installation in existing pipe slots, including pipe slots that contain steam lines, where there is a risk of thermal damage to the coatings, alone or in combination with high humidity, even more so. direct steam shock. The ability of the coatings to protect the optical waveguide from mechanical stresses and moisture has been correlated with the strength of the wet adhesive forces between the primary coating and the optical waveguide. The dual requirements of strong bonding of the primary coating to the waveguide and ease and uniform separation ability have presented a difficult challenge in the formulation of primary coatings. The present invention is directed to meet these dual requirements of adhesion and separation ability.

BRIEF DESCRIPTION OF THE INVENTION The present invention relates to an optical fiber tape. The optical fiber tape includes a plurality of substantially coplanar optical fibers and a tape matrix material which holds the plurality of coated optical fibers in substantially co-planar alignment. Each of the optical fibers includes a core, a liner layer that surrounds and is adjacent to the core, and a primary polymeric coating material that surrounds and is adjacent to the liner layer. The primary polymeric coating material is adhered to the liner layer to form a liner layer separation surface-primary polymeric coating material. During the application of a longitudinal separation force on the liner layer separation surface-primary polymeric liner material, the tape matrix material and the primary polymer liner material are substantially removed from the liner layer leaving a residual layer smooth, continuous of the primary polymeric coating material with a thickness of less than about 5 μm. The present invention also relates to a tape fiber optic which includes a plurality of substantially coplanar, coated optical fibers and a ribbon matrix material that holds the plurality of coated optical fibers in substantially co-planar alignment. Each of the optical fibers includes a core, a liner layer that surrounds and is adjacent to the core, and a primary polymeric coating material that surrounds and is adjacent to the liner layer. The primary polymeric coating material includes a silicone. In another aspect, the present invention relates to a method for separating an optical fiber tape. The method includes providing an optical fiber tape that includes a plurality of substantially coplanar, coated optical fibers and a tape matrix material that maintains the substantially co-planar alignment of the plurality of coated optical fibers. Each of the substantially coplanar, coated optical fibers comprises a core, a liner layer that surrounds and is adjacent to the core, and a primary polymeric coating material that surrounds and is adjacent to the liner layer. The primary polymeric coating material is adhered to the liner layer to form a liner layer separation surface-primary polymeric coating material. The method further includes apng a longitudinal separation force to the effective primary polymeric liner layer-material separation surface to substantially remove the ribbon matrix material and the primary polymeric coating material of the liner layer. The primary polymeric coating material is constituted to leave in the liner layer a smooth, continuous residual layer of the primary polymeric coating material with a thickness of less than about 5 μm as a result of applying the longitudinal separation force. The present invention also relates to a coating composition adapted to provide a primary coating for an optical glass fiber. The coating composition comprises a silicone. The fiber optic tapes of the present invention allow the removal of the primary polymeric coating material from the liner layer, so that the residual primary polymeric coating material remaining in the liner layer by the removal process is sufficiently uniform to allow precise alignment of the tapes. Accordingly, the optical fiber tapes of the present invention allow production of high quality separations by the use of mass melt separation techniques. At the same time, the adhesion of the primary coating material to the liner layer is sufficient to prevent delamination in humid environments and, therefore, prevent exposure of the liner and core layer to the destructive effects of moisture and other environmental hazards.

BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a cross-sectional view of an example of a fiber tape 4 in accordance with the present invention. Figures 2A-C are perspective views of a tape separating apparatus that couples and separates an optical fiber tape according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an optical fiber tape, a cross-sectional view of which is presented in Figure 1. In one aspect, the optical fiber tape of the present invention includes a plurality of substantially coplanar, coated optical fibers. 2 and a tape matrix material 4 which holds the plurality of coated optical fibers in substantially co-planar alignment. Each of the optical fibers includes a glass core 6, a liner layer 8 that surrounds and is adjacent to the glass core 6, and a primary polymeric coating material 10 that surrounds and is adjacent to the liner layer 8. Primary polymeric coating material 10 is adhered to the liner layer 8 to form a liner layer separation surface 12-primary polymeric coating material. During the application of a longitudinal separation force on the lining layer 12 of the primary polymeric liner layer, the ribbon matrix material 4 and the primary polymeric liner material 10 are substantially removed from the liner 8 layer leaving a continuous, smooth, residual layer of primary polymeric coating material 10 with a thickness of less than about 5 μm. The primary polymeric coating material 10 can optionally be surrounded by and adjacent a secondary polymeric coating material 14. The secondary coating material 14 can be a hermetic coating or, alternatively, a loose tube coating. Regarding the type of secondary coating employed, it is preferred that the surface of the secondary coating material 14 be such that no glue occurs between the adjacent convolutions of the fiber, resulting in a jump adjustment of a spool of the process. The optical fiber components of the optical fiber tape of the present invention may, optionally, also include a coloring material, such as a dye ink coating that identifies each optical fiber in the tape. Preferably, the optional ink coating surrounds and is adjacent to the outer polymeric coating material. Referring again to Figure 1, wherein the optical fiber includes the polymeric coating material optional secondary 14, as illustrated in Figure 1, the ink coating 16 surrounds and is adjacent to the secondary polymeric coating material 14. The optical fiber contained in the optical fiber tape of the present invention includes a core. Suitable fibers include pitch-index fibers, which have a core whose refractive index is constant with the distance from the fiber axis, and fibers of marked index, which have a core whose refractive index varies with the distance from the axis of the index. the fiber. Any conventional core material, such as those identified in the U.S. Patent may be used. No. 4,486,222 to Berkey, which is incorporated herein by reference. The core typically is a silica glass having a cylindrical cross section and a diameter ranging from 5 to 10 μm for single mode fibers and 20 to 100 μm for multiple mode fibers. The core may optionally contain amounts which vary from other materials, such as titanium, thallium, gerium and boron oxides, which modify the refractive index of the core. Alternatively, the core can be a plastic material. However, since the attenuation loss for plastic-core fibers is large, typically several hundred dB / km, compared with the loss of attenuation for glass core fibers, typically less than 10 dB / km, the use of fibers with a plastic core are usually limited to very short path lengths.

The core is advantageously surrounded by and adjacent a liner layer having a refractive index less than the refractive index of the core. A variety of lining materials, both plastic and glass (eg, silica and borosilicate glass), are used in the construction of conventional optical fibers, and any of these materials can be used to form the liner layer in the fiber optic tapes of the present invention. In many applications, the core and liner layer have a discernible core-liner limit. Alternatively, the core and liner layer may lack a different boundary, such as where the core and liner, both usually made of glass, melt together to form a fiber with marked index. In another arrangement, the lining layer can be made from a series of glass or plastic layers of varying refractive index. The fiber optic tape of the present invention may contain optical fibers having any of the above core-shell configurations. The liner layer is surrounded by and adjacent to a primary polymeric coating material. The primary polymeric coating material is constituted such that, during the application of a longitudinal separation force on the lining layer separation surface-primary polymeric coating material, the tape matrix material and the primary polymeric coating material They are substantially removed from the liner layer leaving a smooth, continuous residual layer of the primary polymeric coating material. The thickness of the primary polymeric coating material is less than about 5 μm, preferably less than about 3 μm, most preferred, less than about 1 μm. The magnitude of the separation force used to perform the removal is not critical. However, particularly where the number of optical fibers contained in the optical fiber tape is large, it is preferred that the longitudinal separation force be less than about 5000 g, and more preferably, less than 4000 g alcohol. Those who are skilled in the art are well aware of the methods for measuring the longitudinal separation force. A suitable method for substantially removing the tape matrix material, the primary polymeric coating material, the secondary polymeric coating material, and the optional ink coating employs Fujikura HJS-01 or Sumitomo JR4A thermal separators adjusted to 60-140 °. C and a sheet gap of 150 μm and a separation speed of 100 mm / min. Typical separation tools of this type are illustrated in Figures 2A-2C. The separation apparatus 20 comprises a movable portion 22 and a stationary portion 24, slidably coupled together on the guides 26. The movable portion 22 includes a movable base portion 28 and a movable cover 30, coupled with hinge to the movable base portion 28. The stationary portion 24 includes a stationary base portion 32 and a stationary cover 34, hingedly coupled to the stationary base portion 32. In operation, the optical fiber tape 36 is placed in a fiber fastener 38, so that from about 25 mm to about 30 mm of the fiber optic belt 36 comes out of the fiber fastener 38. With the movable cover 30 and the stationary cover 34 of the separator 20 in the open position, as shown in figure 2A, the fiber fastener 38 is placed in the separating apparatus 20 as indicated by the arrow A in figure 2A. Movable cover 30 and stationary cover 34 then close, forcing opposite sheets 40 against fiber optic tape 36, and causing sheets 40 to cut into fiber optic tape 36 from opposite sides to a depth equal to half of the leaf gap. The closure of the stationary cover 34 also forces a portion of the optical fiber tape 36 against the heater 42 which is contained in the stationary base portion 34 and which is connected to an energy supply (not shown) through the wire 43 The portion of the optical fiber tape 36 in contact with the heater 42 is heated to the temperature of the heater 42, typically between about 5 and 10 seconds, and then the movable portion 22 is pulled away from the stationary portion 24. , in a line parallel to the guides 26, exposing the fibers separate optics 44, as indicated by arrow B in Figure 2B. Referring now to Figure 2C, then the movable cover 30 and the stationary cover 34 are opened, and the fiber holder 38 of the separator apparatus 20 is removed, as indicated by the arrow C in Figure 2C. The removed ribbon die material, primary polymeric coating material, optional secondary polymeric coating material, and optional ink coating, collectively referred to as tube 46, are retained in the stationary portion 24. The adhesion of the primary polymeric coating material of the optical fiber to the liner layer, as measured by the peel-off value of 180 °, is preferably from about 50 to about 2 g. Methods for measuring 180 ° peelable stress are described in ASTM D-903, which is incorporated herein by reference. The primary polymeric coating material preferably comprises a silicone. Suitable silicones are polymeric organosilicon compounds containing Si-O-Si linkages and having the general formula (R1R2Si-0) x, wherein x is an integer of at least 2, preferably from 2 to 105, and R1 and R2 are the same or different and are alkyl portions. Preferably, R1 and R2 are unsubstituted C1 to C6 alkyl groups, such as methyl, ethyl, propyl, iso-propyl, butyl, sec-butyl, tert-butyl, pentyl, iso-pentyl, neopentyl, hexyl, 2-methylpentyl , 3-methylpentyl, cyclohexyl and similar. More preferably, R1 and R2 are each methyl. Suitable silicones include linear, branched or cyclic siloxanes. An illustrative example of a suitable linear siloxane is hexa ethyldisiloxane. Preferred cyclic siloxanes are those containing at least three silicon atoms, more preferably, 3 to 6 silicon atoms. These include hexacylcylcyltrrisiloxane, octamethy1 cyclotyl rasiloxane ("OMCTS"), decamethylcyclopentasiloxane, dodeca ethylcyclohexasiloxane, and mixtures thereof. OMCTS is particularly preferred for use in the optical fiber tapes of the present invention. The precipitation of these and other polymethylcyclosiloxanes is described in the U.S. Patent. No. 4,669,420 to Baile et al., Which is incorporated herein by reference. Preferably, the silicone is present in the primary polymeric coating material in an amount of about 0.25% by weight to the solubility limit of the silicone in the polymer or polymers that constitute the primary polymeric coating material. Typically, the solubility limit is the largest silicone concentration that does not cause darkness of the primary polymeric coating material. Particularly preferred concentrations of silicone in the primary polymeric coating material are from about 2 to about 10% by weight, more preferably from about 3 to about 7% by weight. The primary polymeric coating material it preferably includes ethylenically unsaturated polymers, curable with ultraviolet, such as a poly (alkyl) alkacrylate or an acrylate-terminated acrylate. Suitable poly (alkyl acrylate) s include methyl methacrylate, ethyl methacrylate, and the like. Other suitable primary polymeric coating materials, such as those described in the U.S. Patent. No. 4,324,575 to Levy, which is incorporated herein by reference, will be apparent to those skilled in the art. A particularly preferred primary polymeric coating material combines a silicone with the coating material described in the U.S. Patent. No. 5,219,896 to Coady et al. ("Coady"), which is incorporated herein by reference. Briefly, the particularly preferred coating material comprises: (1) from about 30 to about 80% by weight, based on the total weight of the coating composition, of an acrylate-terminated polyurethane ("acrylated polyurethane") having an average molecular weight of about 2,500 to about 8,000 daltons; (2) from about 20 to about 60% by weight of an acrylate of an unsubstituted or substituted C7-C10 alkylphenol, preferably C8-C9, which is alkoxylated with an alkylene oxide of C2-C4 and contains about of about 5 moles of oxide per mole of phenol; (3) from about 5 to about 30% by weight of at least one alkyl acrylate having a glass transition temperature ("Tg") of about -90 ° C to about -45 ° C, preferably less than about -60 ° C; and (4) from about 2 to about 10% by weight, preferably from about 3 to about 7% by weight, of a silicone. The acrylate-terminated polyurethane is the reaction product of a prepolymer, an organic diisocyanate, and a hydroxy acrylate. The prepolymer is a carbon chain that can comprise oxygen and / or nitrogen atoms to which the terminal acrylate functionality is added through the use of diisocyanate. The prepolymer has on average about two polymerization prepolymer functional groups that are reactive with the isocyanate group, for example, a hydroxy, mercapto, amine or the like group. The average molecular weight of the prepolymer is from about 700 to about 2,000, preferably from about 800 to about 2,000, daltons. Suitable prepolymers include polycarbonates, and mixtures of polyethers (for example, poly (propylene oxide) and poly (tetramethylene glycol)) and polycarbonates. Although all the prepolymers described above are suitable for use in the optical fiber tape of the present invention, when used with the alkoxylated phenol acrylate, the polycarbonate diols give superior results, especially from the standpoint of hydrolytic stability and oxidant. , and in this way they are preferred. Polycarbonate diols are produced conventionally by the alcoholysis of diethylcarbonate or diphenylcarbonate with an alkane diol, such as 1,4-butane diol, 1,6-hexane diol, and 1,12-dodecane diol; an alkylene ether diol, such as triethylene glycol and tripropylene glycol; or mixtures thereof. Suitable polycarbonate diols include DURACARB 122, commercially available from PPG Industries and PERMANOL KM10-1733, commercially available from Permuthane Inc., MA. DURACARB 122 is produced by the alcoholysis of diethylcarbonate with hexane diol. A wide variety of diisocyanates can be used alone or in admixture with another to prepare the acrylated polyurethane. Representative diisocyanates include toluene diisocyanate, methylene diphenyl diisocyanate, hexamethylene diisocyanate, cyclohexylene diisocyanate, methylene dicyclohexane diisocyanate, 2,2,4-trimethyl hexamethylene diisocyanate, phenylene diisocyanate, 4-chloro-l diisocyanate, 3-phenylene, 4,4'-biphenylene diisocyanate, 1,5-naphthylene diisocyanate, 1,4-tetramethylene diisocyanate, 1,6-hexamethylene diisocyanate, 1,10-decamethylene diisocyanate, 1,4-diisocyanate -cyclohexylene, and, preferably, isophorone diisocyanate ("IPDI"). The hydroxy acrylate can be a monoacrylate or a polyacrylate. The reaction of the isocyanate group with a hydroxy group of the hydroxy acrylate produces a urethane ligation which results in the formation of a urethane acrylate finished. Suitable monohydric acrylates are the C2-C4 hydroxy alkyl acrylates and polyacrylates, such as 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, glyceryl diacrylate, and mixtures thereof. The acrylate counterparts of the previous acrylates can also be used. To prepare the acrylated polyurethane, the diol of prepolymer, diisocyanate, and hydroxy acrylate (in a molar ratio of about 1: 2: 2, respectively, to about 5: 6: 2, respectively) are mixed with a minor amount of a catalyst , such as from about 0.03 to about 0.1, preferably about 0.04, percent by weight of dibutyl tin dilaurate. A dry gas sprinkler, such as dry air, nitrogen or carbon dioxide, is used to ensure that no moisture is present that could adversely affect the reaction. The reaction is conducted at a temperature of about 40 ° to about 80 ° C for a period sufficient to consume substantially all of the hydroxy functionality of the prepolymer diol and the hydroxy acrylate and the free nitrogen-carbon-oxygen groups ("NCO" ) of the diisocyanate. Other details that relate to the preparation of acrylated polyurethanes are described in Coady, which is incorporated herein by reference. The primary polymeric coating material may include small amounts (typically from about 0.5 to about 6%) of photoinitiators and inhibitors, adhesion promoters and conventional stabilizers. The photoinitiators used are conventional components of light-curable ethylenically unsaturated coatings. Suitable photoinitiators are aryl ketones, such as benzophenone, acetophenone, diethoxy acetophenone, benzoin, benzyl, anthraquinone, and the like. A commercial photoinitiator is illustrated by IRGACURE 184, which is a hydroxycyclohexyl phenyl ketone available from Ciba-Geigy Corp., Ardsley, NY. When necessary, the free radical polymerization can be inhibited by the use of an agent, such as phenothiazine or butylated hydroxytoluene in an amount of less than about 0.1% by weight. Silane coupling agents are conventional adhesion promoters and can typically be present in an amount of about 1% by weight. Exemplary silane coupling agents include methacryloxypropyl trimethoxy silane range, commercially available from Huís, Bristol, PA, under the trademark MEMO and mercaptopropyl trimethoxy silane range, which is commercially available from Union Carbide Corp- (Danbury, CT) under the designation A-189 Conventional stabilizers, such as hindered amines, which provide ultraviolet stability for the cured composition, may be present in amounts of less than about 1% by weight. Illustrative stabilizers include bis (2,2,6,6-tetramethyl-4-) piperidinyl) sebacate, which is commercially available from Ciba-Geigy Corp., Ardsley, NY, under the trademark TINUVIN 770 and thiodiethylene (3,5-di-tert-butyl-4-hydroxy) hydrocinnamate, also commercially available from Ciba- Geigy Corp. under the trademark IRGANOX 1035. Typical coating materials for use in secondary coatings include urethane acrylate liquids whose molecules intertwine when exposed to ultraviolet light. Other materials suitable for use in the secondary polymeric coating material, as well as considerations related to the selection of these materials, are well known to those of skill in the art and are described in, for example, U.S. Pat. No. 5,104,433 to Chapín et al. ("Chapín Patents"), which are incorporated herein by reference. Various additives may also be present that improve one or more coating properties, including the aforementioned additives incorporated in the primary polymeric coating material. The thickness of the liner and each of the coatings as well as the diameter of the core are not critical to the practice of the present invention. By way of illustration, a typical diameter of the core and the liner layer, taken together, is approximately 125 microns for single mode fibers. Each polymeric coating material has a thickness of approximately 30 micrometers so that the diameter The overall coverage of the coated optical fiber is approximately 250 microns. The fiber optic tape of the present invention further includes a ribbon matrix material which maintains the plurality of coated optical fibers in substantially co-planar alignment. The tape material may encapsulate the plurality of optical fibers, or, alternatively, the optical fibers may be bonded together with the matrix material. The matrix material can be made from a single layer or from a mixed body construction. Suitable matrix materials include polyvinyl chloride as well as those other materials known to be useful as primary and secondary polymeric coating materials. Preferably, the matrix material is the same type of material as that used in the optional secondary coating. The production of the optical fiber tape of the present invention can be carried out by normal methods. In brief, the method involves fabricating the core and liner layer, coating the liner layer with the primary polymeric coating material, optionally coating the primary polymeric coating material with a secondary polymeric coating material, optionally arranging an ink coating around of the secondary coating material, arranging a plurality of the coated optical fibers in a coplanar configuration, and applying a ribbon matrix material to the fibers so that the flat arrangement is maintained afterwards. The core and liner layer are typically produced in a single operation by methods that are well known in the art. Suitable methods include the double crucible method, described, for example, in Midwinter, Optical Fibers for Transmission, New York: John Wiley, pp. 166-178 (1979), which is incorporated herein by reference; tube bar procedure; and contaminated deposited silica ("DDS") procedures (commonly referred to as chemical vapor deposition ("VPO") procedures). A variety of DDS processes are known and are suitable for producing the core and liner layer used in the optical fiber tape of the present invention. They include external CVD, described in, for example, Blakenship and others, "The Outside Vapor Deposition Method of Fabricating Optical Waveguide Fibers", IEEE J. Quantum Electron, 18: 1418-1423 (1982), which is incorporated herein by reference; and internal CVD (also commonly referred to as modified CVD ("MCVD") or internal vapor deposition ("IVD")), described in, eg, Nagel et al., "An Overview of the Modified Chemical Vapor Deposition (MCVD) Process and Performance, "IEEE J. Quantum Electron, 18: 459-476 (1982), which is incorporated herein by reference. The primary coating material is coated on a glass fiber using conventional methods. The coating procedure can carried out on an individual fiber or on a plurality of fibers. It is well known to extract glass fiber optics from a specially prepared cylindrical reform which has been heated locally and symmetrically at a temperature of about 2000 ° C. As the preform is heated, either by feeding it into and through an oven, a fiberglass is extracted from the molten material. Optional primary and secondary coating materials are applied to the glass fiber after it has been extracted from the preform, preferably immediately after. In general, the primary polymeric coating material, in an uncured or solution form, is applied to the glass fiber, typically by passing the fiber through a reservoir of uncured or dissolved primary polymeric coating material. The coating is then cured, or the solvent is then removed, to produce a cured and coated optical fiber. The curing method can be thermal or photonic, such as by exposing the coated uncured polymeric coating material to ultraviolet light, depending on the nature of the polymeric coating material and the initiator being used. During the extraction process, it is often advantageous to sequentially apply the primary and secondary coating polymeric materials. A method for applying double layers of coating materials to a moving glass fiber is described in the patent of E.U.A. No. 4,474,830 by Taylor, which is incorporated herein by reference. Another method for applying double layers of coating materials on a glass fiber is described in the U.S. patent. No. 4,851,165 by Rennell et al., Which is incorporated herein by reference. In the same way, the ink coating can be applied. The coated optical fibers are then arranged in a coplanar arrangement and maintained in this arrangement while a matrix material of the uncured tape is applied and cured. In some cases, it may be advantageous to initially prepare a plurality of coated fiber optic reels and then produce the fiber optic tape in a separate process, particularly if the optimum fiber removal and coating and ribbon manufacturing speeds are significantly different A typical matrix material of the UV curable tape is a mixture comprising a resin, a diluent and a photoinitiator. The resin may include a diethylene-terminated resin, synthesized from a reaction of a hydroxy-terminated alkyl acrylate with the reaction product of a polyether polyol polyester of molecular weight of 1000 to 6000 daltons with an aromatic or aliphatic diisocyanate . Alternatively, the resin may include a diethylene-terminated resin synthesized from the reaction of the glycidol acrylate with a polymer or polyether finished with carboxyl of molecular weight 1000 to 6000 daltons. The diluent may comprise monofunctional or multifunctional acrylic acid esters having a molecular weight of 100 to 1000 daltons, N-vinylpirolidone or vinyl caprolactam. Photoinitiators suitable for use in the ribbon matrix material include ketone compounds, such as diethoxyacetophenone, acetophenone, benzophenone, benzoin, anthraquinone and benzyl dimethyl ketal. In a typical composition, the matrix matrix material may include a resin (50 to 90% by weight), diluents (5 to 40% by weight) and a photoinitiator (1 to 10% by weight). Other suitable additives such as methacrylates, epoxides curable with UV light or unsaturated polyesters can also be used. Several methods are known in the art to encapsulate the optical fibers in a ribbon matrix material. For a short time, the plurality of coated optical fibers are conducted side by side through a liquid matrix matrix material, which is advantageously released under pressure or under vacuum in a coating chamber of substantially rectangular cross-section. More detailed information regarding the production of encapsulated fiber optic tapes is available in the patent of E.U.A. No. 4,752,112 by Mayr and the patent of E.U.A. No. 5,486,378 by Oestreich et al., Which are incorporated herein by reference. In cases where the matrix material of the tape is the same as the outermost polymeric coating material, the ribbon matrix can be formed by applying a suitable solvent to the outermost polymeric coating material, while the adjacent optical fibers are in tangential contact. The solvent dissolves a portion of the outermost polymeric coating material and, after evaporating it, the adjacent optical fibers come to fuse with each other, thus forming the optical fiber tape. In this process, solvent drying can be carried out by exposing it to the atmosphere, or it can be facilitated by directing gas that absorbs the solvent onto the moving fiber ribbon. Before being deposited on a reel, the tape is advantageously dusted with powder such as calcium stearate to reduce any residual adhesiveness that could have resulted from exposure to the solvent. During the formation of the tape matrix material from the outermost polymeric coating material, the solvent must be carefully selected and applied in controlled quantities and concentrations. If the solvent is too active, it will tend to separate the outermost polymeric coating material along with it. On the other hand, a weak solvent will not sufficiently dissolve the coating. More details regarding solvent welding as a means to produce an optical fiber tape is described in British Patent No. 1,570,624 and the US Patent. No. 4,147,407, both by Eichenbaum and others, which are incorporated in the present invention as a reference. The present invention also relates to a method for separating an optical fiber tape. The method includes providing an optical fiber tape that includes a plurality of substantially coplanar coated optical fibers and a ribbon matrix material that maintains substantially coplanar alignment of the plurality of coated optical fibers. Each of the substantially coplanar coated optical fibers comprises a glass core, a surrounding coating layer and adjacent to the glass core, a surrounding primary polymeric coating material and adjacent to the coating layer, an optional surrounding secondary coating polymeric material and adjacent to the primary polymeric coating material, and an optional ink coating surrounding and adjacent to the secondary polymeric coating material or, in the case where an optional polymeric secondary coating material is not used, adjacent to the primary polymeric coating material. The primary polymeric coating material is adhered to the coating layer to form a coating layer-primary polymeric coating material interface. The method further includes applying a longitudinal separation force at the interface of the coating layer-effective primary polymeric coating material to substantially remove the matrix material from the tape and the polymeric coating material. primary (as well as optional secondary polymeric coating material and optional ink coating if present) of the coating layer. The matrix material of the tape is formed to leave a uniform and continuous residual layer of the primary polymeric coating material with a thickness of less than about 5 μm as a result of applying the longitudinal separation force. The longitudinal separation force is provided to the interface of the coating layer-primary polymeric coating material by a separation tool. The separation tool has a pair of opposing cutting blades and a blade space equal to, or slightly greater than, the core diameter and the coating layer combined (i.e., equal to, or slightly greater than, the sum of the diameter of the core and twice the thickness of the coating layer). The tape is inserted into the separation tool near one end of the tape, with the portion thereof having its liners removed extending beyond the leading edge of the cutting sheets, and the sheets meeting until the distance that separates them is equal to the space of the sheet. This action cuts across opposite sides of the ribbon matrix material, the optional ink coating, the optional secondary polymer coating material, and most of the primary polymeric coating material, so that it can be made a well defined cut in the coating materials and the ribbon matrix. While held in the closed position, the sheets move towards the end of the tape being separated, thus exerting a longitudinal separation force (i.e., parallel to the axis of the optical fiber) at the coating layer interface. primary polymeric coating material. In most cases, the magnitude of the longitudinal separation force that is required to remove the coating material and the ribbon matrix can be reduced by applying heat, typically on the scale of about 80 to about 110 ° C during less than a second to several minutes, to the surface of that portion of the matrix material of the tape being removed before applying the longitudinal force. Particularly well-suited tools are available to carry out the separation operation. Preferred separation tools include Fujikura HJS-01 and Suunto JR4A thermal separators fixed at 60 to 140 ° C and a sheet space of 150 μm. Its construction and its use are described in figures 2 A-C, which were already described above. The present invention is further illustrated by the following examples.

EXAMPLES EXAMPLE 1 Preparation of primary coating compositions A polyurethane terminated with acrylate was prepared in a suitable flask by mixing 2-hydroxyethyl acrylate, isophorone diisocyanate, dibutyltin dilaurate, octyl / decyl acrylate and phenothiazine in the amounts described in Table 1 below. During the reaction, agitation and a spray of dry air were provided and maintained. The temperature of the mixture was raised to about 40 ° C and maintained at that temperature for about 2 hours. Then, the polycarbonate diol, in an amount described in Table 1, was introduced into the flask and mixed with the mixture. The mixing temperature was raised to about 70 ° C, and the mixture was kept at that temperature for a period sufficient to consume substantially all of the free NCO.

TABLE 1 Polycarbonate finished with acrylate Diol-based polyurethane Component Parts (by weight) Polycarbonate diol 55.50 2-hydroxyethyl acrylate 5.46 Isophorone diisocyanate 19.01 Octyl acrylate / decile 19.94 Dibutyltin dilaurate 0.06 Phenothiazine 0.03 The polycarbonate diol used in the formulation was PERMANOL KM 10-1733, commercially available from Permuthane Coatings, Peabody, MA. The octyl / decyl acrylate used was obtained from Radcure Specialties, Inc., Louisville, KY under the ODA factory name. An aliquot of the acrylated polyurethane described above was mixed with alkoxylated phenol acrylate and phenoxyethyl acrylate in proportions described in Table 2, coating A.

TABLE 2 Primary coating compositions Parts by weight Component Coating A Coating B Acrylated Polyurethane 62.3 57.9 Phenoxyethyl Acrylate 33.1 30.8 IRGACURE 184 * 2.0 1.9 PAPO * 1.0 0.9 Silanod 1.0 0.9 IRGANOX 1035 *? 0.5 0.5 POLYCAT DBU? 0.1 0MCTS9 7.0 a The acrylated polyurethane prepared in accordance with Table 1 was used. b An aryl ketone photoinitiator, commercially available from Ciba-Geigy Corp., Ardsley, NY. c An acylphosphine oxide photoinitiator, commercially available from Ciba-Geigy Corp., Ardsley, NY. d Accession promoter A-189, existing in commerce from Union Caribe Corp., Danbury, CT. e A stabilizer, existing in commerce from Ciba Geigy Corp., Ardsley, NY. f An amine catalyst, commercially available from Air Products and Chemicals, Inc., Allentown, PA. to Octamethylcyclotetrasiloxane.

To each of 5 small bottles containing composition A, 1, 3, 5, 7 and 10% by weight of OMCTS were added. The bottles were covered and inverted repeatedly to mix the components. With the exception of the bottle containing 10% by weight of the OMCTS, which appeared slightly cloudy, all the bottles were clear, indicating that the solubility limit of the OMCTS in the primary coating composition A was around 10% by weight. To maximize the effect of silicone on the separation properties, and to avoid the complications that OMCTS could cause without dissolving, primary coating B was formulated to contain 7% by weight of OMCTS. The primary coating B containing OMCTS, whose composition is described in Table 1, was prepared by adding 7 parts of OMCTS per 93 parts of the primary coating composition A and mixing the mixture overnight. During the inspection in the morning, a non-cloudy solution was observed.

EXAMPLE 2 Preparation of fiber optic tapes Individual pattern 1528 fibers were removed and coated from Corning Incorporated (Corning, NY) with the primary coating composition A or with the primary coating composition B using the coating methods described in the Chapin patents, which are incorporated in the present invention as a reference. The fibers were then coated with a secondary coating material such as formulation 950-044 and with an LTS ink composition., both available from DSM Desotech, Inc. (Elgin, IL). Using the method and apparatus described in the U.S.A. No. 5,486,378 by Oestreich et al., Which is incorporated herein by reference, and a ribbon matrix material (formulation 950-706 from DSM Desotech, INC. (Elgin, IL)), were obtained. 12 fiber ribbons. One tape used the fibers made with the primary coating composition A, and the other tape used the fibers made with the primary coating composition B.

EXAMPLE 3 Individual fiber evaluation Individual filaments of fibers A and B were evaluated, respectively, lacking OMCTS and presenting OMCTS at 7% by weight, to determine the strength of the strip in dry and wet (EIA / TIA-455-178) and the strength of dry and wet extraction (ITM-5). The data for individual fiber, presented in Table 3, show that the OMCTS-containing fiber exhibits a reduced extraction force in both the wet and dry states, compared to fiber without OMCTS. The reduced extraction force is a common feature of the fibers exhibiting increased yield in the strip in the form of a belt.

TABLE 3 Results of evaluation of the individual fiber Water bath at 70 ° C for 30 days Attenuation 1300 nm TYP < 0.05dB / km 0.01 dB / km 1550 nm TYP < 0.05dB / km 0.02 dB / km 1 TYP indicates that the presented value is a size of values obtained from this and other samples of the same material.

To evaluate the effect of OMCTS on the adhesion between the coating layer and the primary coating, each of the fibers was soaked in water at room temperature and at 70 ° C for 30 days. MIS tests were carried out, which correlate well with the degree of delamination as a result of immersion in water, after 2, 8, 14 and 30 days of immersion. The results of MIS, presented in Table 3, suggest that the addition of OMCTS does not inhibit the formation of adhesion between the primary coating and the coating layer. The absence of delamination is further confirmed by the absence of signal attenuation increased at 1300 nm and 1550 nm after immersion of the OMCTS fiber at 70 ° C for 30 days. If delamination had occurred, significant increases in attenuation in a water immersion environment would have been expected. This further demonstrates that the addition of OMCTS does not interfere with the development of adhesion with the primary coating.

The two coatings also exhibited almost the same water extraction and absorption characteristics.

EXAMPLE 4 Evaluation of fiber optic tape For each of the two 12-fiber tapes, the strength of the strip, the degree of cleanliness and the out-of-tube category were determined. The strength of the strip tape was determined using Fujikura thermal separators (Alcoa Fujikura Ltd., Duncan, SC) fixed at 100 ° C and having a fixed sheet space at 150 μm. The samples were separated at 100 mm / min, the strength of the strip was monitored at 200 Hz, and the maximum strength of the strip was recorded for each test. The degree of cleanliness was classified on a subjective scale of 1 to 5, where 1 denotes a completely clean strip without residues, and 5 denotes a residue after separation that can not be removed with alcohol. The data of the tape is presented in table 4.

As the data show, a significant decrease in the strength of the strip was observed, from 5800 g for the tape that does not contain OMCTS (designated as tape A), to 3974 g for the tape containing OMCTS (designated as tape B) . The degree of cleanliness for the tape containing OMCTS was significantly lower (indicating a cleaner tape), comparatively with the pattern ribbon.

TABLE 4 Evaluation of fiber optic tape Although the invention has been described in detail for illustrative purposes, it should be understood that such detail is solely for that purpose, and that those skilled in the art can make variations without departing from the spirit and scope of the invention which is defined by the following claims .

Claims (47)

NOVELTY OF THE INVENTION CLAIMS

1. - An optical fiber tape comprising: a plurality of substantially coplanar coated optical fibers, each comprising a core, a coating layer surrounding and adjacent the core, and a primary polymeric coating material surrounding and adjacent to the coating layer, characterized in that the primary polymeric coating material is adhered to the coating layer to form a coating layer-primary polymeric coating material interface and a tape matrix material that maintains substantially coplanar alignment of said plurality of coated optical fibers, characterized in that after applying a longitudinal separation force at the interface of the coating layer-primary polymeric coating material, said matrix material of the tape and the primary polymeric coating material are substantially removed from the coating layer leaving a layer of resin. uniform and continuous dual of the primary polymeric coating material with a thickness of less than about 5 μm.

2. An optical fiber tape according to claim 1, characterized in that the residual layer is less than about 1 μm thick.

3. - An optical fiber tape according to claim 1, characterized in that the longitudinal separation force is less than 5000 g.

4. An optical fiber tape according to claim 3, characterized in that the longitudinal separation force is less than 4000 g.

5. An optical fiber tape according to claim 1, characterized in that the primary polymeric coating material is adhered to the coating layer with a peel strength of 180 ° of about 50 to about 2 g.

6. An optical fiber tape according to claim 1, characterized in that said ribbon matrix material surrounds said plurality of coated optical fibers.

7. An optical fiber tape according to claim 1, characterized in that said ribbon matrix material comprises an ethylenically unsaturated polymer curable with ultraviolet light.

8. A fiber optic tape according to claim 1, characterized in that the primary polymeric coating material comprises an ethylenically unsaturated polymer curable with ultraviolet light.

9. A fiber optic tape according to claim 8, characterized in that the primary polymeric coating material comprises a poly (acrylate) of alkyl).

10. An optical fiber tape according to claim 1, characterized in that the primary polymeric coating material comprises a polyurethane terminated with acrylate.

11. A fiber optic tape according to claim 1, characterized in that the primary polymeric coating material also comprises a silicone.

12. A fiber optic tape according to claim 11, characterized in that the silicone is present in the primary polymeric coating material in an amount of about 2 to about 10 weight percent.

13. A fiber optic tape according to claim 12, characterized in that the silicone is present in the primary polymeric coating material in an amount of from about 3 to about 7 weight percent.

14. An optical fiber tape according to claim 11, characterized in that the silicone is a polymeric organosilicon compound containing Si-0-Si bonds and has the general formula (-RaR2Si-0-) x, characterized in that x is an integer from 2 to 100,000, and Ri and R2 are the same or different and are alkyl portions.

15. A fiber optic tape according to claim 11, characterized in that the silicone is a cyclic siloxane containing 3 to 6 silicon atoms.

16. A fiber optic tape according to claim 15, characterized in that the silicone is octamethyl-1-cyclic tetrasiloxane.

17. An optical fiber tape according to claim 1, characterized in that each of said substantially coplanar coated optical fibers further comprises a surrounding secondary polymeric coating material and adjacent to the primary polymeric coating material.

18. A fiber optic tape according to claim 17, characterized in that each of said substantially coplanar coated optical fibers further comprises a coating of ink surrounding and adjacent to the secondary polymer coating material.

19. An optical fiber tape comprising: a plurality of substantially coplanar coated optical fibers, each comprising a core, a surrounding coating layer and adjacent to the core, and a primary polymeric coating material surrounding and adjacent to the coating layer. coating, characterized in that the primary polymeric coating material contains a silicone and a matrix material of the tape which maintains in alignment substantially coplanar said plurality of coated optical fibers.

20.- A fiber optic tape in accordance with the claim 19, characterized in that the primary polymeric coating material further comprises an ethylenically unsaturated polymer curable with ultraviolet light.

21. An optical fiber tape according to claim 19, characterized in that the primary polymeric coating material further comprises a polyurethane terminated with acrylate.

22. A fiber optic tape according to claim 19, characterized in that the silicone is present in the primary polymeric coating material in an amount of from about 2 to about 10 weight percent.

23. An optical fiber tape according to claim 22, characterized in that the silicone is present in the primary polymeric coating material in an amount of from about 3 to about 7 weight percent.

24. A fiber optic tape according to claim 19, characterized in that the silicone is a polymeric organosilicon compound containing Si-0-Si bonds and has the general formula (-RiR Si-0-) x, characterized in that x is an integer from 2 to 100,000, and R1 and R2 are the same or different and are alkyl portions.

25. A fiber optic tape according to claim 19, characterized in that the silicone is a cyclic siloxane containing from 3 to 6 silicon atoms.

26. - An optical fiber tape according to claim 25, characterized in that the silicone is octamethylcyclote rasiloxane.

27. An optical fiber tape according to claim 19, characterized in that said ribbon matrix material surrounds said plurality of coated optical fibers.

28. An optical fiber tape according to claim 19, characterized in that said ribbon matrix material comprises an ethylenically unsaturated polymer and is curable with ultraviolet light.

29. A fiber optic tape according to claim 19, characterized in that each of said substantially coplanar coated optical fibers further comprises a surrounding secondary polymeric coating material and adjacent to the primary polymeric coating material.

30. An optical fiber tape according to claim 29, characterized in that each of said optical fibers further comprises a coating of ink surrounding and adjacent to the secondary polymeric coating material.

31. A method for separating an optical fiber tape comprising: providing an optical fiber tape comprising a plurality of substantially coplanar coated optical fibers and a tape matrix material that maintains substantially coplanar alignment of the plurality of coated optical fibers, characterized in that each of the substantially coplanar coated optical fibers comprises a core, a surrounding coating layer and adjacent to the core, and a primary polymeric coating material surrounding and adjacent to the coating layer. coating, characterized in that the primary polymeric coating material is adhered to the coating layer to form a coating layer-primary polymeric coating material interface, and a longitudinal separation force is applied at the coating layer-coating material interface effective polymeric polymer to substantially remove the matrix material from the tape and the primary polymeric coating material from the coating layer, characterized in that the primary polymeric coating is constituted to leave a uniform and continuous residual layer of the ial of primary polymeric coating with a thickness of less than about 5 μm as a result of applying said longitudinal separation force.

32.- A method in accordance with the claim 31, characterized in that the residual layer is less than about 1 μm thick.

33.- A method according to claim 31, characterized in that the longitudinal separation force is less than 5000 g.

34.- A method in accordance with the claim 33, characterized in that the longitudinal separation force is less than 4000 g.

35.- A method in accordance with the claim 31, characterized in that the primary polymeric coating material is adhered to the coating layer with a 180 ° peel strength of about 50 to about 2 g.

36.- A method according to claim 31, characterized in that the matrix material surrounds the plurality of coated optical fibers.

37. A method according to claim 31, characterized in that the primary polymeric coating material further comprises a silicone.

38.- A method according to claim 37, characterized in that the silicone is present in the primary polymeric coating material in an amount of about 2 to about 10 weight percent.

39. A method according to claim 31, characterized in that each of the substantially coplanar coated optical fibers further comprises a secondary polymeric coating material surrounding and adjacent to the primary polymeric coating material, and characterized in that when applying said separation force longitudinally at the interface of the coating layer-primary polymeric coating material, the secondary polymeric coating material is removed.

40. - A method according to claim 39, characterized in that each of the substantially coplanar coated optical fibers further comprises a coating of ink surrounding and adjacent to the secondary polymeric coating material, and characterized in that by applying said longitudinal separation force at the interface of coating layer-primary polymeric coating material, the coating of ink is removed.

41. A coating composition adapted to provide a primary coating for a glass optical fiber comprising a silicone.

42. A coating composition according to claim 41, characterized in that the silicone is present in the coating composition in an amount of from about 2 to about 10 weight percent.

43. A coating composition according to claim 42, characterized in that the silicone is present in the coating composition in an amount of from about 3 to about 7 weight percent.

44. A coating composition according to claim 41, characterized in that said silicone is a polymeric organosilicon compound containing Si-O-Si bonds and has the general formula (-R1R2Si-0-) x, characterized in that x is an integer from 2 to 100,000, and R1 and R2 are the same or different and are alkyl portions.

45.- A conformal coating composition with claim 41, characterized in that said silicone is a cyclic siloxane containing from 3 to 6 silicon atoms.

46.- A coating composition according to claim 45, characterized in that said silicone is octamethylcyclotetrasiloxane.

47. A coating composition according to claim 41, comprising: from about 30 to about 80 weight percent of an acrylate-terminated polyurethane; from about 20 to about 60 weight percent of an acrylate of an unsubstituted phenol or a phenol substituted by C7-C10 alkyl which is alkoxylated with a C2-C4 alkylene oxide and contains from about 1 to about 5 moles of oxide per mole of phenol; from about 5 to about 30 weight percent of at least one alkyl acrylate; and from about 2 to about 10 weight percent of said silicone. SUMMARY OF THE INVENTION The present invention relates to an optical fiber tape; the optical fiber tape includes a plurality of substantially coplanar coated optical fibers and a ribbon matrix material which maintains the plurality of coated optical fibers in substantially coplanar alignment; each of the optical fibers includes a glass core, a surrounding coating layer and adjacent to the glass core, and a primary polymeric coating material, preferably containing a silicone, surrounding and adjacent to the coating layer; the primary polymeric coating material is adhered to the coating layer to form a coating layer-primary polymeric coating material interface; after applying a longitudinal separation force at the interface of the coating layer-primary polymeric coating material, the matrix matrix material and the primary polymeric coating material are substantially removed from the coating layer; a uniform and continuous residual layer of the primary polymeric coating material with a thickness of less than about 5 μm remains in the coating layer; these fiber optic tapes exhibit improved separation properties without sacrificing the adhesion of the primary coating material, and are well adapted to be joined by techniques of union by mass fusion. BS / MG / blm * lpm * mmm P97-1243F