UNDERSEA CONDUITS TECHNICAL FIELD

[0001] The present application relates to an adhesive tape for conduits, undersea conduits and methods of making conduits. Specifically, the present application relates to an adhesive tape comprising a final tensile strength of at least about 80% of the initial tensile strength after being exposed to salt water at a temperature of about 60°C for 21 days. In some embodiments, the present application relates to an adhesive tape comprising a final tensile strength of at least about 80% of the initial tensile strength after being exposed to salt water at a temperature of about 90°C for 21 days.

BACKGROUND

[0002] Conduits are used to transport materials. In some instances, it is desired to transport materials to and/or from offshore locations. In these instances, undersea conduits are used to transport oil and gas from offshore wells to exploration platforms.

[0003] Adhesive tapes have been used in the construction and assembly of conduits. Specifically, filament-reinforced tapes, such as, for example, a glass filament reinforced tape available commercially from 3M Company under the designation Scotch 890 Filament tape, have been used for the assembly of undersea conduits.

[0004] U.S. Patent Publication No. 2008/0085388 (to Tynan Jr et al) describes a pressure-sensitive tape comprising a backing, a layer of corrosion-resistant filaments and a pressure-sensitive adhesive layer that coats the filaments and binds them to the backing. Preferably, the filaments of Tynan Jr et al are corrosion-resistant LCP filaments of polyester of 2-naphthalene-6-carboxylic acid and 4-hydroxy benzoic acid. This publication also describes a method for constructing a member for undersea deployment comprising a tubular member, winding a wire reinforcement around the tubular member and winding a corrosion-resistant filament-reinforced material over the wire reinforcement, and coating the filament- reinforced member with a layer of extruded polymer.

[0005] Undersea conduits are expected to have a service life of over 25 years under challenging conditions including varying pressures, acidic or basic pH, temperature variations and salt water.

Accordingly, there is a need for an adhesive tape for use in undersea conduits that withstands these conditions for long periods of time.

SUMMARY OF THE INVENTION

[0006] The present inventors sought to develop an adhesive tape that withstands challenging undersea environments. Particularly, the present inventors developed an adhesive tape particularly useful in salt water having a pH from about 4 to about 10. [0007] In one embodiment, the present application relates to an adhesive tape that has a final tensile strength of at least about 80% of the initial tensile strength after exposure to salt water at a temperature of about 60°C for 21 days. In another embodiment, the present application relates to an adhesive tape that has a final tensile strength of at least about 80% of the initial tensile strength after exposure to salt water at a temperature of about 90°C for 21 days.

[0008] In another aspect, the present application relates to an adhesive tape comprising: a backing having a first side and an opposite second side; a first adhesive layer adjacent the first side of the backing; a reinforcing layer comprising filaments adjacent the first adhesive layer; and a second adhesive layer adjacent the reinforcing layer; wherein the adhesive tape has a final tensile strength of at least about 80% of the initial tensile strength after being exposed to salt water at a temperature of about 60°C for 21 days. In some embodiments, the adhesive tape has a final tensile strength of at least about 80% of the initial tensile strength after being exposed to salt water at a temperature of about 90°C for 21 days.

[0009] In some embodiments, at least one of the first adhesive layer and the second adhesive layer is prepared from a solvent-based adhesive. In other embodiments, the adhesive is a water-based adhesive. In yet another embodiment, the adhesive is a hot-melt adhesive.

[0010] In some embodiments, the filaments are polyester filaments. In some embodiments, the polyester filaments are selected from the group consisting of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polycyclohexylenedimethylene terephthalate (PCT), and combinations thereof.

[001 1] In some embodiments, the adhesive tape of the present application may further comprise a protective layer adjacent the second adhesive layer. In other embodiments, the adhesive tape may additionally comprise a third adhesive layer adjacent the protective layer.

[0012] In some embodiments, the adhesive tape of the present application my further comprise a second reinforcing layer comprising filaments. In some embodiments, the adhesive tape further comprises a third adhesive layer adjacent the second reinforcing layer.

[0013] In yet another aspect, the present application relates to a conduit comprising: enclosed conveying means; and an adhesive tape adhered to the enclosed conveying means, wherein the adhesive tape has a final tensile strength of at least about 80% of the initial tensile strength after being exposed to salt water a temperature of about 60°C for 21 days. In another aspect, the adhesive tape has a final tensile strength of at least about 80% of the initial tensile strength after being exposed to salt water at a temperature of about 90°C for 21 days.

[0014] In another aspect, the present application relates to a method of making an conduit comprising the steps of: providing an enclosed conveying means; and adhering an adhesive tape to the enclosed conveying means; wherein the adhesive tape comprises a backing, a first adhesive layer, a reinforcing layer comprising filaments and a second adhesive layer. In some embodiments, the filaments are salt water resistant polymeric filaments. In some embodiments, the filaments are polyester filaments selected from the group consisting of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polycyclohexylenedimethylene terephthalate (PCT), and combinations thereof.

[0015] These and various other features and advantages will be apparent from a reading of the following detailed description.

BRIEF DESCRIPTION OF THE FIGURES

[0016] The disclosure may be more completely understood in consideration of the following detailed description of various embodiments of the disclosure in connection with the accompanying drawings, in which:

[0017] Fig. 1 is a cross-section of an exemplary embodiment of an adhesive tape according to the present application.

[0018] Fig. 2 is a cross-section of another exemplary embodiment of an adhesive tape according to the present application.

[0019] Fig. 3 is a cross-section of another exemplary embodiment of an adhesive tape according to the present application.

[0020] Fig. 4 is a cross-section of another exemplary embodiment of an adhesive tape according to the present application.

DETAILED DESCRIPTION OF THE INVENTION

[0021] In the following description, reference is made to the accompanying set of drawings that form a part hereof and in which are shown by way of illustration several specific embodiments. It is to be understood that other embodiments are contemplated and may be made without departing from the scope or spirit of the present disclosure. The following detailed description, therefore, is not to be taken in a limiting sense.

[0022] For purposes of the present application, the term "conduit" as used herein broadly refers to enclosed means of conveying (e.g., tubular member) for transporting one or more materials. In some embodiments, the conduit is used to transport utilities such as natural gas, oil, water, electrical cable, optical filament, phone cable, and the like.

[0023] Typically, adhesive tapes are susceptible to corrosion and/or degradation by water. The speed of corrosion and degradation may be vastly increased by the presence of salt water. This low resistance to salt water is especially problematic in underwater and/or undersea applications.

[0024] Filament-reinforced tapes have been used in the construction and assembly of undersea conduits. However, in some instances, filaments used in filament-reinforced tapes were corroded and caused the tape to fail (e.g., the adhesive tape peeled away from the substrate to which the tape was adhered). In other instances, the adhesive used in the adhesive tape degraded and as a result adhesive and/or cohesive failure occurred. [0025] To overcome the above-mentioned problems, a cover layer has sometimes been used in conjunction with the adhesive tape. The cover layer is typically disposed on the outermost surface of the adhesive tape (i.e., the surface that would be in direct contact with salt water).

[0026] In oil drilling and recovering operations, undersea conditions are sometimes worsened due to high pressures arising from the depth at which the wells are drilled and varying pH of the salt water, which may range from about 3 to about 7. In some instances, carbon dioxide and hydrogen sulfide present in the oil may pass through the metallic and polymeric layers of the enclosed conveying means and contribute to altering the pH of the surrounding salt water.

[0027] Offshore drilling infrastructure is difficult to build and expensive to maintain. As a result, oil companies expect long service lives. In addition, due to the complex nature of the offshore building and components, maintenance of undersea materials is difficult and sometimes poses an environmental risk of leakage and/or explosion.

[0028] The present inventors sought to develop an adhesive tape that can be applied to a substrate that can be immersed in salt water such as, for example, undersea conduits, without the need of a cover layer on the outermost surface of the tape. The present inventors also sought to develop an adhesive tape that can be immersed in salt water and has a service life greater than 20 years. In some embodiments, the present adhesive tape has a service life greater than 25 years. Accelerated weathering tests may be used to anticipate failure modes and conditions of adhesive tapes used in undersea applications. As such, the present inventors developed an adhesive tape that has a final tensile strength of at least about 80% of the initial tensile strength after being exposed to salt water at a temperature of about 60°C for 21 days. In some embodiments, the adhesive tape has a final tensile strength of at least 80% of the initial tensile strength after being exposed to salt water a temperature of about 90°C for 21 days.

[0029] In one aspect, the present application relates to an adhesive tape. Specifically, embodiment 1 of the present application relates to an adhesive tape comprising: a backing having a first side and an opposite second side; a first adhesive layer adjacent the first side of the backing; a reinforcing layer comprising filaments adjacent the first adhesive layer; and a second adhesive layer is disposed on the filaments and contacts a major surface of the first adhesive layer opposite the backing; wherein the adhesive tape has a final tensile strength of at least about 80% of the initial tensile strength after being exposed to salt water at a temperature of about 60°C for 21 days.

[0030] A second embodiment of the present application relates to the adhesive tape of embodiment 1, further comprising a sealer layer adjacent the reinforcing layer.

[0031] A third embodiment of the present application relates to the adhesive tape of embodiment 1, wherein the first adhesive layer is prepared from a solvent- based adhesive.

[0032] A fourth embodiment of the present application relates to the adhesive tape of embodiment 1, wherein at least one of the first adhesive layer or the second adhesive layer comprises one of a rosin resin, a polyterpene resin, a modified polyterpene resin, a hydrocarbon resin and a modified hydrocarbon resin. [0033] A fifth embodiment of the present application relates to the adhesive tape of embodiment 4, wherein the polyterpene resin is based on beta-pinene.

[0034] A sixth embodiment of the present application relates to the adhesive tape of any of the preceding embodiments wherein one of the first adhesive layer or the second adhesive layer has a weight average molecular weight of about 1600 g/mol.

[0035] A seventh embodiment of the present application relates to the adhesive tape of any of the preceding embodiments wherein one of the first adhesive layer or the second adhesive layer has a glass transition temperature (Tg) of less than 65°C and a softening point of less than 120°C.

[0036] An eighth embodiment of the present application relates to the adhesive tape of embodiment 7, wherein the Tg is 62°C and the softening point is 115°C.

[0037] A ninth embodiment of the present application relates to the adhesive tape of embodiment 1, wherein the filaments are selected from the group consisting of fiberglass, carbon fiber, polyester fiber, nylon fiber, aramide fiber, basalt fiber, polyethylene fiber, polypropylene fiber and combinations thereof.

[0038] A tenth embodiment of the present application relates to the adhesive tape of embodiment 1, wherein the filaments are fiberglass filaments and selected from the group consisting of E-glass, S-glass, C-glass, ECR-glass, AR-glass, and combinations thereof.

[0039] An eleventh embodiment of the present application relates to the adhesive tape of embodiment 1, wherein the filaments are twisted.

[0040] A twelfth embodiment of the present application relates to the adhesive tape of embodiment 1, wherein the backing is selected from the group consisting of polyolefin, polyester, polyetherketone, polyvinyl chloride, polycarbonate, polysulfone, polyamide and polyimide.

[0041] A thirteenth embodiment of the present application relates to the adhesive tape of embodiment 1, further comprising a protective layer adjacent the second adhesive layer.

[0042] A fourteenth embodiment of the present application relates to the adhesive tape of embodiment 13, further comprising a third adhesive layer adjacent the protective layer.

[0043] A fifteenth embodiment of the present application relates to the adhesive tape of embodiment 1, further comprising a release layer adjacent to the second side of the backing.

[0044] A sixteenth embodiment of the present application relates to the adhesive tape of embodiment 1, wherein the adhesive tape has a final tensile strength of at least about 80% of the initial tensile strength after exposure to salt water at a temperature of about 90°C for 21 days.

[0045] A seventeenth embodiment of the present application relates to the adhesive tape of embodiment 1, wherein at least one of the first adhesive layer or the second adhesive layer is prepared from a water- based adhesive and a hot-melt adhesive.

[0046] An eighteenth embodiment of the present application relates to the adhesive tape of embodiment 1, wherein at least one of the first adhesive layer or the second adhesive layer further comprises a tackifying resin having a softening point between 60°C and 160°C. [0047] A nineteenth embodiment of the present application relates to the adhesive tape of embodiment 1, wherein the adhesive has a Tg between about -40°C and about + 20°C.

[0048] A twentieth embodiment of the present application relates to the adhesive tape of embodiment 1, wherein the filaments are polyester filaments selected from the group consisting of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polycyclohexylenedimethylene terephthalate (PCT), and combinations thereof.

[0049] A twenty -first embodiment of the present application relates to the adhesive tape of claim 1, further comprising a second reinforcing layer and a third adhesive layer.

[0050] In another aspect, the present application relates to a conduit. Specifically, embodiment 22 of the present application relates to a conduit comprising: an enclosed conveying means; and an adhesive tape adhered to the enclosed conveying means, the adhesive tape comprising a backing, a first adhesive layer, a reinforcing layer comprising filaments and a second adhesive layer; wherein the adhesive tape has a final tensile strength of at least about 80% of the initial tensile strength after being exposed to salt water at a temperature of about 60°C for 21 days.

[0051] A twenty-third embodiment of the present application relates to the conduit of embodiment 22, wherein the adhesive tape further comprises a sealer layer adjacent the reinforcing layer.

[0052] A twenty -fourth embodiment of the present application relates to the conduit of embodiment 22, wherein the first adhesive layer was prepared from a solvent- based adhesive.

[0053] A twenty-fifth embodiment of the present application relates to the conduit of embodiment 22, wherein one of the first adhesive layer or the second adhesive layer comprises a polyterpene resin.

[0054] A twenty-sixth embodiment of the present application relates to the conduit of embodiment 25, wherein the polyterpene resin is based on beta-pinene.

[0055] A twenty-seventh embodiment of the present application relates to the conduit of embodiment 22, wherein at least one of the first adhesive layer or the second adhesive layer has a weight average molecular weight of about 1600 g/mol.

[0056] A twenty -eighth embodiment of the present application relates to the conduit of embodiment 22, wherein at least one of the first adhesive layer or the second adhesive layer has a Tg of less than 65°C and a softening point of less than 120°C.

[0057] A twenty-ninth embodiment of the present application relates to the conduit of embodiment 22, wherein the filaments are selected from the group consisting of fiberglass, carbon fiber, polyester fiber, nylon fiber, aramide fiber, basalt fiber, polyethylene fiber, polypropylene fiber and combinations thereof.

[0058] A thirtieth embodiment of the present application relates to the conduit of any of embodiments 22 - 29, wherein the adhesive tape comprises a protective layer.

[0059] A thirty-first embodiment of the present application relates to the conduit of embodiment 30, wherein the adhesive tape further comprises an adhesive layer adjacent the protective layer. [0060] A thirty-second embodiment of the present application relates to the conduit of embodiment 22, wherein the adhesive tape has a final tensile strength of at least about 80% of the initial tensile strength after exposure to salt water at a temperature of about 90°C for 22 days.

[0061] A thirty-third embodiment of the present application relates to the conduit of embodiment 22, wherein at least one of the first adhesive layer or the second adhesive layer is prepared from a water- based adhesive or a hot-melt adhesive.

[0062] A thirty-fourth embodiment of the present application relates to the conduit of embodiment 22, wherein the filaments are selected from the group consisting of fiberglass, carbon fiber, polyester fiber, nylon fiber, aramide fiber, basalt fiber, polyethylene fiber, polypropylene fiber and combinations thereof.

[0063] A thirty-fifth embodiment of the present application relates to the conduit of embodiment 22, wherein the polyester fibers are selected from the group consisting of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polycyclohexylenedimethylene terephthalate (PCT), and combinations thereof.

[0064] A thirty-sixth embodiment of the present application relates to the conduit of embodiment 22 wherein the adhesive tape further comprises a second reinforcing layer and a third adhesive layer.

[0065] A thirty-seventh embodiment of the present application relates to the conduit of any of embodiments 22-36, wherein the conduit is placed in salt water.

[0066] In yet another aspect, the present application relates to a method of making a conduit.

Specifically, embodiment 38 of the present application relates to a method of making a conduit comprising the steps of: providing an enclosed conveying means; and adhering an adhesive tape to the enclosed conveying means; wherein the adhesive tape comprises a backing, a first adhesive layer, a reinforcing layer comprising filaments and a second adhesive layer.

[0067] A thirty-ninth embodiment of the present application relates to the method of embodiment 38, wherein the adhesive tape has a final tensile strength of at least about 80% of the initial tensile strength after being exposed to salt water at a temperature of about 60°C for 21 days.

[0068] A fortieth embodiment of the present application relates to the method of embodiment 38, further comprising the step of placing the conduit in salt water.

[0069] A forty-first embodiment of the present application relates to the method of embodiment 38, wherein the adhesive tape has a final tensile strength of at least about 80% of the initial tensile strength after exposure to salt water at a temperature of about 90°C for 21 days.

[0070] A forty-second embodiment of the present application relates to the method of embodiment 38, wherein the filaments are selected from the group consisting of fiberglass, carbon fiber, polyester fiber, nylon fiber, aramide fiber, basalt fiber, polyethylene fiber, polypropylene fiber and combinations thereof.

[0071] A forty-third embodiment of the present application relates to the method of embodiment 41, wherein the polyester fibers are selected from the group consisting of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), polycyclohexylenedimethylene terephthalate (PCT), and combinations thereof. [0072] A forty-fourth embodiment of the present application relates to the method of embodiment 38, wherein at least one of the first adhesive layer or the second adhesive layer was prepared from one of a solvent-based adhesive, a water-based adhesive and a hot-melt adhesive.

[0073] A forty-fifth embodiment of the present application relates to the method of embodiment 38, wherein at least one of the first adhesive layer or the second adhesive layer further comprises one of a rosin resin, a polyterpene, a modified polyterpene, a hydrocarbon resin and a modified hydrocarbon resin.

[0074] A forty-sixth embodiment of the present application relates to the method of embodiment 38, wherein the adhesive tape further comprises a second reinforcing layer and a third adhesive layer.

[0075] In one aspect, as shown in Fig. 1, the present application relates to an adhesive tape 10 comprising a backing 20 having a first side 20a and an opposite second side 20b, a first adhesive layer 30 adjacent the first side 20a of the backing 20, a filament layer comprising filaments 40, and a second adhesive layer 50 coating (i.e., adjacent to) said filaments 40. In some embodiments, the second adhesive layer 50 is disposed on a major surface of the first adhesive 30 on a side opposite the backing 20 and filaments 40 are disposed along the interface of and embedded in the first and second adhesive layers 30, 50.

[0076] In one embodiment, the adhesive tape 10 comprises a polyethylene terephthalate (PET) backing 20 having a first adhesive layer 30 disposed thereon and a second adhesive layer 50 disposed along a major surface of the first adhesive layer 30 opposite the backing 20, where fiberglass filaments (E-glass) 40 are disposed along the interface of and embedded in the first and second adhesive layers 30, 50. The first and second adhesive layers may be used promote adhesion of the adhesive tape to a conduit and to seal the fiberglass filaments to avoid degradation of such filaments due to the combined effect of salt water and temperatures of up to 60°C.

[0077] In some embodiments, the first adhesive layer and the second adhesive layer are identical. In other embodiments, the first adhesive layer and the second adhesive layer have different compositions and/or properties.

[0078] Suitable polymers used to prepare the backing include but are not limited to polyolefin, polyester, polyetheretherketone, polyvinyl chloride, polycarbonate, polysulfone, polyamide and polyimide.

[0079] In some embodiments, filaments from the reinforcing layer are selected from any of the following materials: fiberglass, carbon fiber, polyester fiber, nylon fiber, aramide fiber, basalt fiber, polyethylene fiber, polypropylene fiber and combinations thereof. In some embodiments, the fiberglass filaments are selected from any of the following materials: E-glass, S-glass, C-glass, ECR-glass, AR-glass, and combinations thereof. In some embodiments, the filaments are twisted.

[0080] In some embodiments the polyester fibers include, but are not limited to, those made from polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), poly- 1,4 cyclohexylene-dimethylene terephthalate (PCT) and combinations thereof.

[0081] In some embodiments, the adhesive tape further comprises a sealer layer/composition contacting the filaments. The sealer layer or composition may further protect the filaments from degradation and corrosion. Exemplary sealer layer and/or compositions include, but are not limited to, polyisoprene rubber, styrene-isoprene-styrene block copolymer, and hydrocarbon or polyterpene resin. In some embodiments, the sealer layer and/or composition is an adhesive. In some embodiments, the adhesive is a pressure sensitive adhesive.

[0082] In some embodiments, the second side 20b of the backing 20 is coated with a release agent to facilitate unwinding of the adhesive tape. Suitable release agents include, but are not limited to silicones, urethane -containing polymers, fluorine-containing polymers and compounds, hydrocarbons, waxes, and long, branched alkyl polymers and compounds.

[0083] In some embodiments, a separate release layer is disposed the second side 20b of the backing 20. Contrary to a release coating, the release layer is a stand-alone layer.

[0084] In some embodiments, the adhesive tape further comprises a protective layer adjacent the second adhesive layer opposite the side adjacent to the filaments 40 and optionally, a third adhesive layer adjacent the protective layer opposite the side adjacent to the protective layer. In some embodiments, the third adhesive layer is used to bond the adhesive tape to the substrate (e.g., tubular member). In some embodiments, the third adhesive layer has the same composition as one of the first adhesive layer or the second adhesive layer. In other embodiments, the third adhesive layer has a different composition.

[0085] Fig. 2 is a cross-section of an exemplary embodiment of an adhesive tape having a protective layer according to the present application. Adhesive tape 110 comprises a backing 120 having a first side 120a and a second side 120b (outermost side). The adhesive tape 1 10 further comprises a first high temperature resistant adhesive layer 130 adjacent the first side 120a of the backing 120, a filament layer comprising filaments 140, and a second high temperature resistant adhesive layer 150 coating said filaments 140 and contacting the first high temperature resistant adhesive layer 130 along a major surface opposite the backing 120. A protective layer 160 is disposed on a major surface of the second high temperature resistant adhesive layer 150 opposite the side adjacent to the filaments 140. A third adhesive layer 170 is disposed adjacent the protective layer 160 on a major surface of the protective layer 160 opposite the second high temperature resistant adhesive layer 150. In some embodiments, the third adhesive layer 170 is used to improve adhesion of the adhesive tape 1 10 to a substrate (not shown).

[0086] Fig. 3 is a cross-section of an exemplary embodiment of an adhesive tape having a protective layer according to the present application. Adhesive tape 210 comprises a backing 220 having a first side 220a and a second side 220b (outermost side). The adhesive tape 210 further comprises a first adhesive layer 230 adjacent the first side 220a of the backing, a filament layer comprising filaments 240 disposed on a major surface of the first adhesive layer 230 opposite the backing 220, a sealer layer 230a coating said filaments 240 and a second adhesive layer 250 disposed on the filaments 240. A protective layer 260 is disposed on the second adhesive layer 250. A third adhesive layer 270 is disposed adjacent the protective layer 260 opposite the side adjacent to the second adhesive layer 250. In some embodiments, the addition of third adhesive layer 270 is useful to improve adhesion of the adhesive tape 210 to a substrate (not shown). In some embodiments, the sealer layer 230a is an adhesive layer. In some embodiments the first adhesive layer 230 and/or the second adhesive layer 250 comprises high temperature resistant compositions.

[0087] Fig. 4 is a cross-section of an exemplary embodiment of an adhesive tape having a second reinforcing layer and a third adhesive layer according to the present application. Adhesive tape 310 comprises a backing 320 having a first side 320a and a second side 320b (outermost side). The adhesive tape 310 further comprises a first adhesive layer 330 adjacent the first side 320a of the backing, a first filament layer comprising filaments 340 disposed on a major surface of the first adhesive layer 330 opposite the backing 320, and a second adhesive layer 350 disposed on the filaments 340. A second reinforcing layer comprising filaments 341 is disposed on a major surface of the second adhesive layer 350. A third adhesive layer 370 is disposed adjacent the second reinforcing layer comprising filaments

341, coating the filaments and in contact with at least a portion of the second adhesive layer 350. In some embodiments at least one of the first adhesive layer 330, the second adhesive layer 350, and the third adhesive layer 370 comprises high temperature resistant compositions.

[0088] In an alternative embodiment, the second adhesive layer 350 shown in Fig. 4 is replaced by a sealer layer (not shown). In some embodiments, a protective layer (not shown) is disposed on the third adhesive layer 370.

[0089] In some embodiments, filaments 340 of the first reinforcing layer are the same filaments as the filaments 341 of the second reinforcing layer. In other embodiments, the filaments 340 of the first reinforcing layer are different from the filaments 341 of the second reinforcing layer.

[0090] In some embodiments, the protective layer 160, 260 comprises a polymer selected from at least one of polyolefin, polyester, polyetherketone, polyvinyl chloride, polycarbonate, polysulfone, polyamide and polyimide.

[0091] When the present adhesive tape is adhered to a substrate, water or moisture may contact the adhesive tape from the outermost layer, that is, from the backing. In some instances, the backings have, albeit low, some permeability to water or moisture, allowing the first adhesive layer to be contacted. As a result, the present inventors sought to develop an adhesive tape comprising a first adhesive layer that is resistant to salt water. In some embodiments, the present adhesive tape is resistant to salt water at a temperature of about 60°C for at least 21 days.

[0092] The present inventors also sought to develop an adhesive tape comprising salt water resistant filaments. In some embodiments, the salt water resistant filaments include polymeric filaments such as, for example, polyester filaments. In some embodiments the polyester fibers include, but are not limited to, those made from polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polytrimethylene terephthalate (PTT), poly- 1,4 cyclohexylene-dimethylene terephthalate (PCT) and combinations thereof. In some embodiments, the present adhesive tape is resistant to salt water at a temperature of about 90°C for at least 21 days .

[0093] Accelerated aging tests were performed based on test method ISO 4433-1 ( 1997),

"Thermoplastics pipes; Resistance to liquid chemicals; Classification; Part 1 : Immersion Test Method". The test consisted of submerging the adhesive tape 12 mm wide and 300 mm long in salt water (5 wt% sodium chloride solution) for a predetermined period of time. In the present application, the adhesive tape remained submerged for 21 days (504 hours) at a temperature of about 60°C. Mechanical properties of the tape were measured before and after the aging tests.

[0094] In other instances, especially when the present adhesive tape is adhered to a cable that transports materials, the second adhesive layer may be contacted by such materials. Consequently, in some embodiments, it is preferred that the second adhesive layer exhibits similar levels of resistance to such materials as the first adhesive layer.

[0095] In some embodiments, at least one of the first adhesive layer, the second adhesive layer and/or the third adhesive layer is/are prepared from a solvent-based adhesive to allow for improved wettability of the filaments. In some embodiments, at least one of the first adhesive layer, the second adhesive layer and/or the third adhesive layer comprises a polyterpene resin. In some embodiments, the polyterpene resin is based on beta-pinene (β-pinene). The first, second and/or third adhesive layers may optionally additionally comprise tackifiers, such as, for example, polymerized terpenes, styrenated terpenes, phenolated terpenes, hydrocarbon resins (e.g., C5, C9, C5/C9), and combinations thereof.

[0096] In some embodiments, the weight average molecular weight of at least one of the first adhesive layer or the second adhesive layer is between 300 g/mol and 2000 g/mol, as determined by Rheological Dynamic Spectroscopy (RDS). In some embodiments, the weight average molecular weight is about 1600 g/mol.

[0097] In some embodiments, at least the first adhesive layer was prepared from a solvent-based adhesive and has a weight average molecular weight of 1600 g/mol.

[0098] In some embodiments, at least one of the first adhesive layer or the second adhesive layer is prepared from a water-based adhesive. Suitable water-based adhesives include polymers selected from the group consisting of acrylics, styrene-butadiene copolymers, vinyl acetate copolymers, natural or polyisoprene rubber latexes, and combinations thereof.

[0099] In some embodiments, at least one of the first adhesive layer or the second adhesive layer is prepared from a hot-melt adhesive. Suitable hot-melt adhesives include polymers selected from the group consisting of styrene-isoprene-styrene (SIS), natural rubber, acrylics, styrene-butadiene-styrene, and combinations thereof.

[00100] In some embodiments, the hot-melt adhesive has a Tg of between about -40°C and +20°C.

[00101] In some embodiments, at least one of the first adhesive layer or the second adhesive layer further comprises a tackifying resin (tackifier) having a softening point between about 60°C and between about 160°C. In some embodiments, the tackifying resin has a Tg of about 62°C and softening point 115°C. Suitable tackifying resins include, but are not limited to, rosin resins, polyterpene resins, modified polyterpene resins, hydrocarbon resins, and modified hydrocarbon resins. [00102] In some embodiments, at least one of the first adhesive layer or the second adhesive layer include other optional components such as, for example, crosslinkers, antioxidants, plasticizers, UV absorbers, colorants and fillers.

[00103] In another aspect, the present application relates to a conduit comprising a tubular member and an adhesive tape adhered thereto, where the adhesive tape has a final tensile strength of at least 80% of the initial tensile strength after being exposed to salt water at a temperature of about 60°C for 21 days. In another aspect, the adhesive tape has a final tensile strength of at least 80% of the initial tensile strength after being exposed to salt water at a temperature of about 90°C for 21 days.

[00104] In one embodiment, the conduit of the present application is immersed in salt water. In some embodiments, the conduit is used to transport oil from offshore platforms.

[00105] In yet another aspect, the present application relates to a method of making a conduit comprising the steps of: providing a tubular member, and adhering an adhesive tape to the tubular member, where the adhesive tape comprises a backing, a first adhesive layer, a reinforcing layer comprising filaments and a second adhesive layer.

[00106] Objects and advantages of the present application are further illustrated by the following examples. The particular materials and amounts thereof recited in the examples, as well as other conditions and details, should not be construed to unduly limit the invention. Those of skill in the art will recognize that other parameters, materials and equipment may be used. All parts, percentages and ratios herein are by weight unless otherwise specified.

EXAMPLES

[00107] TEST METHODS

[00108] Aging: accelerated aging was conducted according to the procedure described in test method ISO 4433-1 (1997), "Thermoplastics pipes; Resistance to liquid chemicals; Classification; Part 1 : Immersion Test Method". Test samples 0.5 inch (12 mm) wide and 300 mm long were cut and submersed in tanks were filled with salt water (sodium chloride 0.5 % (w/w) solution at pH = 7) for a predetermined period of time. The tanks were covered, sealed to prevent evaporation and placed in an oven at a temperature of about 60°C or about 90°C for 21 days (504 hours). After the set time period, the samples were removed from the tank, rinsed with deionized water and allowed to air dry overnight. Mechanical properties of the samples were measured and maximum load tensile strength at break was then determined.

[00109] Tensile strength: tensile strength was measured using a tensile strength tester (INSTRON model 5582) using a 10 kN load cell 10 generally following the procedure outlined in ASTM D-3759/3759-M- 05 (2011), "Standard Test Method for Breaking Strength and Elongation of Pressure-Sensitive Tape". The samples were tested at a speed of 150 mm/min. Tensile strength was recorded as the force at break on the load-elongation curve. The curve was normalized to the force per unit width of tape, Newtons per 100 mm of width. 0110] MATERIALS

Isopropyl alcohol Isopropyl alcohol Rhodia, Campinas, Brazil

ULTRA BLUE Blue pigment concentrate RTP, USA

SYLVAREZ TP 2019 Terpene phenolic resin Arizona Chemical, USA

[00111] EXAMPLES

[001121 Comparative Example A

[00113] A commercially available tape was obtained under the trade designation SCOTCH 890 SR from 3M Company of St. Paul, MN, and is hereinafter referred to as Comparative Example A.

[001141 Example 1

[00115] An adhesive tape according to the present application was prepared as follows. An adhesive composition was prepared by mixing the ingredients listed in Table 1 below, in the order provided, wherein weight is expressed as a percentage based on the total weight of the adhesive composition. A first adhesive layer was prepared by coating the adhesive composition onto a PET film backing (obtained under the trade designation THERPHANE 10.15, from Therphane) using a 60 μπι (micrometers) Meyer Bar. The adhesive composition was allowed to dry at a temperature of about 70°C for about 5 minutes, resulting in a dried coating weight of 30 g/m ² (grams/square meter).

[00116] Table 1 - Adhesive Composition

[00117] A reinforcing layer was subsequently prepared by applying fiberglass filaments (obtained under the trade designation E-GLASS G75 from Saint Gobain) to the first adhesive layer using a handspread device.

[00118] The same adhesive composition used in the first adhesive layer was coated onto the reinforcing layer, to form a second adhesive layer. The adhesive composition was applied using the 60 μπι Meyer Bar. The second adhesive layer was allowed to dry at a temperature of about 70°C for about 15 minutes resulting in a dried adhesive coating weight of 40 g/m ² .

TOO 1191 Example 2

[00120] An adhesive tape according to the present application was prepared as generally described in Example 1.

[00121] A PET protective layer (THERPHANE) having a first surface and a second surface, opposite the first surface, was disposed onto the second adhesive layer such that the first surface of the protective layer was in contact with the second adhesive layer.

[00122] A third adhesive layer was formed on the second surface of the protective layer. The third adhesive layer was prepared as described in Example 1 for the second adhesive layer, using the same adhesive composition and coating conditions. The third adhesive layer was allowed to dry at a temperature of about 70°C for about 15 minutes. The resulting dried coating weight was 40g/m ² .

[00123] The adhesive tape of Example 2 comprised, in this order, backing, first adhesive layer, reinforcing layer, second adhesive layer, protective layer and third adhesive layer, wherein first, second, and third adhesive layers comprised the same adhesive composition coated at varying coating weights.

[001241 Example 3

[00125] An adhesive tape according to the present application was prepared as follows. An adhesive composition was prepared by mixing the ingredients listed in Table 2 below, in a twin screw hot melt extruder set at a temperature of about 350-380°F (177 - 193°C). Ingredients listed in table 2 are expressed as weight percentage based on the total weight of the adhesive composition.

[00126] A first adhesive layer was prepared by hot melt coating the adhesive composition onto a 25 μιη PET film backing at coating weight of about 16 g/m ² .

[00127] Table 2 - Adhesive Composition of Example 3

[00128] A reinforcing layer was subsequently prepared by applying PET filament yarns having denier 500 to the first adhesive layer. [00129] The same adhesive composition used in the first adhesive layer was coated onto the reinforcing layer, to form a second adhesive layer. The adhesive composition was hot melt coated at a temperature of about 350-380°F and at a coating weight of 45 g/m ² .

Γ001301 Example 4

[00131] An adhesive tape according to the present application was prepared as generally described in Example 3, except that (i) the reinforcing layer comprised PET filament yarns having denier 1260 obtained from Far Eastern New Century Corporation; and (ii) the second layer adhesive was hot melt coated at a coating weight of about 75 g/m ² .

TOO 1321 Example 5

[00133] An adhesive tape according to the present application was prepared as generally described in Example 3, except that (i) a 40 μπι PET film backing was used; (ii) the adhesive composition used is shown in Table 3, below; and (iii) a second reinforcing layer and a third adhesive layer were formed, as shown in Fig. 4 and described below.

[00134] Table 3 - Adhesive Composition of Example 5

[00135] Comparative Example A and Examples 1-3 were submitted to accelerated aging tests at a temperature of about 60°C using the procedure described above. Results are shown in Table 4, below, wherein "initial tensile strength" (ITS) relates to the tensile strength of the adhesive tape measured prior to the aging test and "final tensile strength" (FTS) relates to the tensile strength of the adhesive tape measured after the aging test. Percent of FTS as it relates to ITS is also provided.

[00136] Table 4

Example A

Example 1 3898 3508 90

Example 2 3835 3679 95

Example 3 4553 4707 103

[00137] Examples 3 and 4 were submitted to accelerated aging tests at a temperature of about 90°C using the procedure described above. Results are shown in Table 5, below, wherein N/M stands for "not measured".

[00138] Table 5

[00139] Those having skill in the art will appreciate that many changes may be made to the details of the above-described embodiments and implementations without departing from the underlying principles thereof. Further, various modifications and alterations of the present application will become apparent to those skilled in the art without departing from the spirit and scope of the invention. The scope of the present application should, therefore, be determined only by the following claims.