Film layers, articles, tapes, wound dressings, and methods

Abstract

The present disclosure provides film layer including a polyurethane film and a release agent distributed in the polyurethane film. Additionally, an article is provided including a film layer disposed on a substrate. A method of making an article includes extruding a film layer on a substrate. A tape is also provided, including a layer of an adhesive disposed on a substrate and a film layer disposed on the layer of adhesive opposite the substrate. Further, a wound dressing is provided including a layer of an adhesive disposed on a substrate, a film layer disposed on the layer of adhesive opposite the substrate, and a carrier frame disposed on a periphery of the film layer.

Description

[0001] FILM LAYERS, ARTICLES, TAPES, WOUND DRESSINGS, AND METHODS

[0002] Summary

[0003] In a first aspect, a film layer is provided. The film layer comprises a polyurethane film and a release agent distributed in the polyurethane film.

[0004] In a second aspect, an article is provided. The article comprises a substrate having a major surface and a film layer according to any embodiment of the first aspect disposed on at least a portion of the major surface of the substrate.

[0005] In a third aspect a tape is provided. The tape comprises a substrate having a first major surface and a second major surface; a layer of an adhesive disposed on at least a portion of the first major surface of the substrate; and a film layer disposed on the layer of adhesive opposite the substrate. The film layer comprises a polyurethane film and a release agent distributed in the polyurethane film.

[0006] In a fourth aspect, a wound dressing is provided. The wound dressing comprises a substrate having a first major surface and a second major surface and a layer of an adhesive disposed on at least a portion of the first major surface of the substrate. The wound dressing further comprises a film layer disposed on the layer of adhesive opposite the substrate and a carrier frame disposed on a periphery of the film layer. The film layer comprises a polyurethane film and a release agent distributed in the polyurethane film.

[0007] In a fifth aspect, a method of making an article is provided. The method comprises extruding onto a major surface of a substrate a film layer comprising a polyurethane and a release agent distributed in the polyurethane film.

[0008] The above summary of the present disclosure is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The description that follows more particularly exemplifies illustrative embodiments. In several places throughout the application, guidance is provided through lists of examples, which examples may be used in various combinations. In each instance, the recited list serves only as a representative group and should not be interpreted as an exclusive list.

[0009] Brief Description of the Drawings

[0010] FIG. 1 is a schematic cross-sectional view of an exemplary film layer;

[0011] FIG. 2 is a schematic cross-sectional view of an exemplary article;

[0012] FIG. 3 is a schematic cross-sectional view of an exemplary tape;

[0013] FIG. 4A is a schematic cross-sectional view of an exemplary wound dressing;

[0014] FIG. 4B is a perspective view of another exemplary wound dressing; and

[0015] FIG. 5 is a schematic cross-sectional view of a single screw extruder. While the above-identified figures set forth various embodiments of the disclosure, other embodiments are also contemplated, as noted in the description. In all cases, this disclosure presents the invention by way of representation and not limitation. The figures are not necessarily to scale. Like numbers used in the figures refer to like components. However, it will be understood that the use of a number to refer to a component in a given figure is not intended to limit the component in another figure labeled with the same number.

[0016] Detailed Description

[0017] Glossary:

[0018] The term “adhesive” as used herein refers to polymeric compositions useful to adhere together two adherends. Examples of adhesives are pressure sensitive adhesives.

[0019] Pressure sensitive adhesive compositions are well known to those of ordinary skill in the art to possess properties including the following: (1) aggressive and permanent tack, (2) adherence with no more than finger pressure, (3) sufficient ability to hold onto an adherend, and (4) sufficient cohesive strength to be cleanly removable from the adherend. Materials that have been found to function well as pressure sensitive adhesives are polymers designed and formulated to exhibit the requisite viscoelastic properties resulting in a desired balance of tack, peel adhesion, and shear holding power. Obtaining the proper balance of properties is not a simple process.

[0020] The term “(meth)acrylate” refers to monomeric acrylic or methacrylic esters of alcohols. Acrylate and methacrylate monomers or oligomers are referred to collectively herein as "(meth)acrylates”. Materials referred to as “(meth)acry late-based” are materials that contain one or more (meth)acrylate and may contain additional co-polymerized free radically polymerizable materials.

[0021] The terms “free radically polymerizable” and “ethylenically unsaturated” are used interchangeably and refer to a reactive group which contains a carbon-carbon double bond which is able to be polymerized via a free radical polymerization mechanism.

[0022] The term “branched” when used to describe an alkyl (meth)acry late refers to the alkyl group, where the branching is not present at the carbon directly adjacent to the ester group, i.e. H2C=CR1- C(O)-O-CH2-Ra, where C(O) refers to a carbonyl group C=O, and the branching occurs in the Ragroup. This is in contrast to a secondary alkyl (meth)acrylate where there are 2 alkyl groups bonded to the carbon directly adjacent to the ester group, i.e. H2C=CR1-C(O)-O-CRbRc, where C(O) refers to a carbonyl group C=O, and Rband Rcare each alkyl groups.

[0023] The terms “room temperature” and “ambient temperature” are used interchangeably to mean temperatures in the range of 20°C to 25°C. The term “adjacent” as used herein when referring to two layers means that the two layers are in proximity with one another with no intervening open space between them. They may be in direct contact with one another (e.g., laminated together) or there may be intervening layers.

[0024] The terms “polymer” and “macromolecule” are used herein consistent with their common usage in chemistry. Polymers and macromolecules are composed of many repeated subunits. As used herein, the term “macromolecule” is used to describe a group attached to a monomer that has multiple repeating units. The term “polymer” is used to describe the resultant material formed from a polymerization reaction.

[0025] The term “alkyl” refers to a monovalent group that is a radical of an alkane, which is a saturated hydrocarbon. The alkyl can be linear, branched, cyclic, or combinations thereof and typically has 1 to 20 carbon atoms. In some embodiments, the alkyl group contains 1 to 18, 1 to 12, 1 to 10, 1 to 8, 1 to 6, or 1 to 4 carbon atoms. Examples of alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl, n-pentyl, n-hexyl, cyclohexyl, n-heptyl, n-octyl, ethylhexyl, n-dodecyl, 2-dodecyl, 3-dodecyl, 4-dodecyl, and 5- dodecyl.

[0026] As used herein, “film” or “layer” refers to a single stratum within a multilayer article.

[0027] As used herein, “thickness” refers to the smallest dimension of a film or layer, e.g., in a z- axis while a major surface of the film or layer is in the x- and y-axes.

[0028] As used herein, “substrate” encompasses films and layers, including microstructured films / layers.

[0029] As used herein, the term “essentially free” in the context of a composition being essentially free of a component, refers to a composition containing less than 1% by weight (wt.%), 0.5 wt.% or less, 0.25 wt.% or less, 0.1 wt.% or less, 0.05 wt.% or less, 0.001 wt.% or less, or 0.0001 wt.% or less of the component, based on the total weight of the composition.

[0030] The words “preferred” and “preferably” refer to embodiments of the disclosure that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the disclosure.

[0031] In this application, terms such as “a”, “an”, and “the” are not intended to refer to only a singular entity, but include the general class of which a specific example may be used for illustration. The terms “a”, “an”, and “the” are used interchangeably with the term “at least one.” The phrases “at least one of’ and “comprises at least one of’ followed by a list refers to any one of the items in the list and any combination of two or more items in the list. As used herein, the term “or” is generally employed in its usual sense including “and / or” unless the content clearly dictates otherwise.

[0032] The term “and / or” means one or all of the listed elements or a combination of any two or more of the listed elements.

[0033] Also herein, all numbers are assumed to be modified by the term “about” and preferably by the term “exactly.” As used herein in connection with a measured quantity, the term “about” refers to that variation in the measured quantity as would be expected by the skilled artisan making the measurement and exercising a level of care commensurate with the objective of the measurement and the precision of the measuring equipment used. Also herein, the recitations of numerical ranges by endpoints include all numbers subsumed within that range as well as the endpoints (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

[0034] As used herein as a modifier to a property or attribute, the term “generally”, unless otherwise specifically defined, means that the property or attribute would be readily recognizable by a person of ordinary skill but without requiring absolute precision or a perfect match (e.g., within + / - 20 % for quantifiable properties). The term “substantially”, unless otherwise specifically defined, means to a high degree of approximation (e.g., within + / - 10% for quantifiable properties) but again without requiring absolute precision or a perfect match. Terms such as same, equal, uniform, constant, strictly, and the like, are understood to be within the usual tolerances or measuring error applicable to the particular circumstance rather than requiring absolute precision or a perfect match.

[0035] It has been unexpectedly discovered that a release agent may be incorporated into a (e.g., elastomeric) polyurethane film, for instance by using an extruder. The resulting film layer may have numerous uses, such as a backing or another component in a medical article. Advantageously, forming a film layer by extrusion can avoid instead coating a solvent-based composition that contains a release agent.

[0036] In a first aspect, a film layer is provided. The film layer comprises: a polyurethane film; and a release agent distributed in the polyurethane film.

[0037] Referring to FIG. 1, a film layer 100 includes a polyurethane film 110 having a first major surface 112 and an opposing second major surface 114.

[0038] In a second aspect, an article is provided. The article comprises: a substrate having a major surface; and a film layer according to any embodiments of the first aspect disposed on at least a portion of the major surface of the substrate. Referring to FIG. 2, an article 200 includes a substrate 220 having a (e.g., first) major surface 222 and a film layer 210 disposed on at least a portion of the major surface 222 of the substrate 220. The film layer 210 has a first major surface 212 and a second major surface 214. Preferably, the release agent of the film layer 210 blooms to the first major surface 212 of the film layer 210, which is opposite the substrate 220. In some cases, the article has a form of a surgical drape, a surgical tape, a suture strip or sheet, an adhesive dressing, a bandage, or a plaster.

[0039] In a third aspect, a tape is provided. The tape comprises: a substrate having a first major surface and a second major surface; a layer of an adhesive disposed on at least a portion of the first major surface of the substrate; and a film layer disposed on the layer of adhesive opposite the substrate, wherein the film layer comprises a polyurethane film and a release agent distributed in the polyurethane film.

[0040] Referring to FIG. 3, a tape 300 includes a substrate 320 having a first major surface 322 and a second major surface 324 and a layer of an adhesive 330 disposed on at least a portion of the first major surface 322 of the substrate 320. The tape additionally includes a film layer 310 disposed on (e.g., a first major surface 332 of) the layer of adhesive 330 opposite the substrate 320. In certain embodiments, the substrate 320 comprises a release liner. It is noted that the adhesive layer 330 also has a second major surface 334 and the film layer 310 has both a first major surface 312 and a second major surface 314.

[0041] In a fourth aspect, a wound dressing is provided. The wound dressing comprises: a substrate having a first major surface and a second major surface; a layer of an adhesive disposed on at least a portion of the first major surface of the substrate; a film layer disposed on the layer of adhesive opposite the substrate, wherein the film layer comprises a polyurethane film and a release agent distributed in the polyurethane film; and a carrier frame disposed on a periphery of the film layer.

[0042] Referring to FIG. 4A, a wound dressing 400a includes a substrate 420 having a first major surface 422 and a second major surface 424 and a layer of an adhesive 430 disposed on at least a portion of the first major surface 422 of the substrate 420. The adhesive 430 has a first major surface 432 and an opposing second major surface 434. The wound dressing 400a also includes a film layer 410 disposed on (e.g., on the first major surface 432) of the layer of adhesive 430 opposite the substrate 420 and a carrier frame 440 disposed on a periphery 415 of (e.g., a first major surface 412 of) the film layer 410. It is noted that the film layer 410 also has a second major surface 414. In the embodiment depicted in FIG. 4A, the wound dressing 400a further includes an optional writable surface 450 attached to (e.g., the first major surface 412 of) the film layer 410 opposite the adhesive layer 430. For example, useful information may be handwritten on the writable surface 450, such as a date that the wound dressing 400a was applied to a user. One suitable material that has a writable surface 450, for instance, is a tape that has a nonwoven backing adhered 456 to the film layer 410 with an acrylic adhesive layer 458.

[0043] Referring to FIG. 4B, a perspective view is provided of another exemplary wound dressing 400b about to be applied to a user 460. In this view, the carrier frame 440 is visible around the full periphery 415 of the film layer 410. Typically, the carrier frame is removable from the wound dressing. In addition, optionally a design 470 is printed on (e.g., the first major surface 412 of) the film layer 410, such as a company logo, other indicia, or a decorative design.

[0044] Each of the layers for use within one or more of these aspects are described in detail below. Film Layer

[0045] K film layer comprises a polyurethane film and a release agent distributed in the polyurethane film.

[0046] Representative examples of suitable release agents include polyvinyl N-alkyl carbamates, polyvinyl N-alkyl carbamides, poly alkyl(meth)acrylate copolymers, silicone polyurea segmented copolymers, and siloxane-acrylate block or graft copolymers. Such release agents are described in detail as polymeric release materials in U.S. Patent No. 6,919,405 (Kinning et al.), incorporated herein by reference in its entirety. U.S. Patent No. 6,919,405 describes employing the release agent in a mixture with a thermoplastic olefin-based polymer comprising an acid or a base functionality. The release agents are not soluble in such an olefin-based polymer. It has now been discovered that these release agents can also be used in a polyurethane film, which was unexpected because the release agents and polyurethane resins are more chemically compatible together such that the release agent would not be expected to bloom to the surface of the polyurethane layer to be able to act as a release agent. In some cases, the release agent is selected from the group consisting of polyvinyl N-alkyl carbamates, polyvinyl N-alkyl carbamides, poly alkyl(meth)acrylate copolymers, silicone polyurea segmented copolymers, and siloxane-acrylate block copolymers. In certain select embodiments, the release agent is polyvinyl octadecyl carbamate, which is commercially available under the trade designations “ESCOAT P-20 Solids” from Anderson Development Co. (Adrian, MI) and “MAYZO 95H” available from Mayzo Inc. (Norcross, GA). Typically, a polyvinyl octadecyl carbamate release agent has a molecular weight from about 50,000 to about 300,000 grams / mole. Polyvinyl alkyl carbamide release agents include the polyethyleneimine alkyl carbamide commercially available under the designation “MAYZO RA-60R” from Mayzo Inc. Often, the release agent is present in an amount of 1 weight percent (wt.%) or greater of the total amount of the film layer, 2 wt.%, 3 wt.%, 4 wt.%, 5 wt.%, 6 wt.%, 7 wt.%, 8 wt.%, 9 wt.%, 10 wt.%, 11 wt.%, or even 12 wt.% or greater; and 15 wt.% or less of the total amount of the film layer, 14 wt.%, 13 wt.%, 12 wt.%, 11 wt.%, 10 wt.%, 9 wt.%, or 8 wt.% or less. In some cases, the release agent is present in an amount of 1 wt.% to 15 wt.% of the total amount of the film layer.

[0047] In certain embodiments, it is advantageous for the film layer to have a high moisture vapor transmission rate (MVTR). U.S. Patent Nos. 3,645,835 (Hodgson) and 4,595,001 (Potter et al.), the disclosures of which are hereby incorporated by reference in their entireties, describe methods of making such films and methods for testing their permeability. Preferably, the film layer (or an article including the film layer) should transmit moisture vapor at a rate equal to or greater than human skin. In some cases, the polyurethane film transmits moisture vapor at a rate of at least 300 g / m2 / 24 hrs / 37° C. / 100-10% relative humidity (RH), using the inverted cup method. In select embodiments, the polyurethane transmits moisture vapor at a rate more preferably of at least 700 g / m2 / 24 hrs / 37° C. / 100-10% RH, and most preferably at least 2000 g / m2 / 24 hrs / 37° C. / 100-10% RH, using the inverted cup method. The inverted cup method is as described as the ““Wet” MVP determination” in U.S. Pat. No. 4,595,001.

[0048] Suitable high moisture vapor transmission rate polyurethanes for use as the polyurethane film include those described in detail in U.S. Pat. No. 4,595,001. Additionally, some useful commercially available polyurethane resins include aromatic polyether thermoplastic polyurethanes available under the trade designations “PELLETHANE” and “ESTANE”, both from Lubrizol Advanced Materials, Inc. (Cleveland, OH).

[0049] The film layer is preferably conformable to anatomical surfaces. As such, when the film layer is applied to an anatomical surface, it conforms to the surface even when the surface is moved. The preferred film layer is also conformable to animal anatomical joints. When the joint is flexed and then returned to its unflexed position, the film layer stretches to accommodate the flexion of the joint, but is resilient enough to continue to conform to the joint when the joint is returned to its unflexed condition.

[0050] The thickness of the film layer may be 6 micrometers or greater, 8 micrometers, 10 micrometers, 12 micrometers, 15 micrometers, 17 micrometers, 20 micrometers, 22 micrometers, 25 micrometers, 27 micrometers, 30 micrometers, 32 micrometers, 35 micrometers, 37 micrometers, or 40 micrometers or greater; and 50 micrometers or less, 45 micrometers, 40 micrometers, 35 micrometers, 30 micrometers, 25 micrometers, 20 micrometers, 15 micrometers, or 10 micrometers or less. In some cases, the film layer has a thickness of 6 micrometers to 50 micrometers. Thickness may be determined using a micrometer gauge or doing a microscopic analysis of a cross-sectional sample of a layer or article.

[0051] Substrate

[0052] The substrate of any of the article, the tape, or the wound dressing is not particularly limited. In some cases, the substrate comprises a sheet of paper or polymeric fdm. Often, the substrate comprises or consists of a release liner. Release liners are sheet materials that have a low adhesion coating on at least one surface. When the substrate is included as part of a tape or wound dressing, the adhesive can be disposed on a release liner. At the time of using the tape or wound dressing, the release liner may be removed and the adhesive placed into contact with another surface (e.g., another substrate or a wound area).

[0053] Suitable release liners may comprise flexible paper and polymeric films having sufficient dimensional stability to hold layers and structures formed thereon in position relative to one another without excessive stretching. Suitable paper liners include, but are not limited to, densified Kraft paper (commercially available from, for example, Loparex North America, Willowbrook, IL), poly -coated paper such as polyethylene coated Kraft paper, and the like. Suitable polymeric film / liners include, but are not limited to, thermoplastic polymer films including polyalkylenes, e.g., polyethylene and polypropylene; polybutadiene, polyisoprene; polyalkylene oxides, e.g., polyethylene oxide; polyesters, e.g., PET and PBT; polyamides; polycarbonates, polystyrenes, block copolymers of any of the proceeding polymers, and combinations thereof. Other suitable polymeric materials include polyimide, polysilicone, polytetrafluoroethylene, polyethylenephthalate, polyvinylchloride, or combinations thereof. Polymer blends of any of the above may also be employed, and nonwoven or woven liners may also be used.

[0054] In some embodiments, any or all of the major surfaces of a release liner may include a release coating, which may be the same or different, to tune or otherwise modify their release values. In various embodiments, which are not intended to be limiting, the release coatings applied to the major surfaces of the release liners may be selected from a fluorine-containing material, a silicone-containing material, a fluoropolymer, a silicone polymer, or a poly (meth)acry late ester derived from a monomer including an alkyl (methjacrylate having an alkyl group with 12 to 30 carbon atoms. In one embodiment, the alkyl group on the alkyl (methjacrylate can be branched. Illustrative examples of useful fluoropolymers and silicone polymers can be found in U.S. Patent No. 4,472,480 (Olson), U.S. Patent No. 4,567,073 and U.S. Patent No. 4,614,667 (both Larson et al), incorporated herein by reference in their entireties. Illustrative examples of useful poly(meth)acrylate esters can be found in U.S. Patent Appl. Publ. No. 2005 / 0118352 (Suwa), incorporated herein by reference in its entirety. Adhesive Layer

[0055] Exemplary suitable adhesives for an adhesive layer include pressure-sensitive adhesives Suitable pressure sensitive adhesives comprise, for instance, an acrylate copolymer pressure sensitive adhesive or a silicone pressure sensitive adhesive.

[0056] Suitable acrylate copolymer pressure sensitive adhesives which can be used in tapes and wound dressings of the present disclosure are the adhesives which are typically applied to the skin such as the acrylate copolymers described in U.S. Patent No. RE 24,906 (Ulrich), particularly a 96:4 iso-octyl acrylate:acrylamide copolymer. Also preferred is an 70:15:15 isooctyl acrylate: ethyleneoxide acrylate :acry lie acid terpolymer, as described in U.S. Patent No. 4,737,410 (Example 31) (Kantner). Other useful adhesives are described in U.S. Pat. Nos. 3,389,827 (Abere et al.); 4,112,213 (Waldman); 4,310,509 (Berglund et al.); and 4,323,557 (Rosso et al.). Inclusion of medicaments or antimicrobial agents in the adhesive is also contemplated, as described in U.S. Patent Nos. 4,310,509 and 4,323,557. Each of the above-mentioned U.S. patents is incorporated herein by reference in its entirety.

[0057] The preferred pressure sensitive adhesives described above preferably transmit moisture vapor at a rate greater to or equal to that of human skin. While such a characteristic can be achieved through the selection of an appropriate adhesive, it is also contemplated in the present invention that other methods of achieving a high relative rate of moisture vapor transmission may be used, such as pattern coating the adhesive on the backing, as described in U.S. Patent No. 4,595,001.

[0058] Suitable silicone pressure sensitive adhesives include those described in detail in U.S. Patent No. 9,359,529 (Liu et al.), incorporated by reference herein in its entirety. In some embodiments, the silicone pressure sensitive adhesive comprises a crosslinked, silicone elastomer, wherein the adhesive is substantially free of catalysts and initiators. Silicone pressure sensitive adhesives may be prepared by combining silicone materials (e.g., silicone gums or elastomers) with an appropriate tackifying resin (e.g., an MQ resin tackifier), hot melt coating the resulting combination, and curing using electron beam (E-beam) irradiation. Generally, any known additives useful in the formulation of pressure sensitive adhesives (e.g., dyes, pigments, fillers, flame retardants, rheology modifiers, flow agents, surfactants, microspheres (e.g., expandable microspheres), and the like may also be included.

[0059] The adhesive layer thus formed may be a continuous layer, a patterned layer, or a combination thereof. Additionally, the adhesive layer may comprise sublayers. The sublayers may be the same adhesive material, or they may be different adhesive materials. If the sublayers are different materials, typically the different materials are hot melt processable pressure sensitive adhesive compositions of the type described above. The sublayers may likewise be continuous layers or paterned layers. In some embodiments, the adhesive layer comprises two sublayers, a first sublayer comprising a continuous layer, and a second sublayer disposed on the first sublayer in a patern.

[0060] Carrier Frame

[0061] K carrier frame for a wound dressing is formed from a carrier material, cut to fit a particular sized and shaped wound dressing. Advantageously, even with the presence of a release agent in the polyurethane film layer, a good carrier bond is still achieved in wound dressings according to the present disclosure.

[0062] The carrier material used to supply the carriers for wound dressings is preferably more rigid than the film layer (which acts as a dressing backing) to prevent the film layer from wrinkling during application. The carrier material can also be heat-sealable to the film layer, with or without a low adhesion coating, for the purpose of manufacturing wound dressings. In general, the preferred carrier materials can include, but are not limited to, ethylene vinyl acetate copolymer or ethylene acrylic acid coated papers and polyester films. Preferably the carrier material is transparent to visualize the site during application. The most preferred carrier is EVA coated polyester available under the tradename SCOTCHPAK from 3M Company (St. Paul, MN). Methods

[0063] In a fifth aspect, a method of making an article is provided. The method comprises: extruding onto a major surface of a substrate a film layer comprising a polyurethane and a release agent distributed in the polyurethane film. It has been discovered that a release agent may be incorporated into a (e.g., elastomeric) polyurethane film, for instance by using an extruder.

[0064] In some cases, the extruder is a single screw extruder. Typically, single screw extruders are not employed when two or more components are combined for extrusion, thus it was unexpected that a release agent could successfully be incorporated into a polyurethane resin to form an extruded film layer using a single screw extruder. For instance, a release agent may be included in an amount of up to about 5 wt.% of the total amount of combined release agent and polyurethane resin when using a single screw extruder for extrusion of the film layer. The release agent, in some cases, is present in an amount of 1 wt.% to 5 wt.% or 1 wt.% to 2 wt.% of the total amount of the film layer. In select embodiments, the single screw extruder comprises a screw having a mixing element. Referring to FIG. 5, a schematic cross-sectional view is provided of a single screw extruder 500 having a mixing element 525. In this case, the mixing element 525 includes at least a gap between adjacent threads 535 of the screw 515.

[0065] In some embodiments, a twin screw extruder may be employed for the extrusion. Twin screw extruders are often used when two or more components are combined for extrusion and it has been found that a greater amount of a release agent may be used the film layer is extruded using a twin screw extruder to mix polyurethane resin and the release agent together than when a single screw extruder is employed. In select embodiments, the release agent is present in an amount of 1 wt.% to 15 wt.%, 3 wt.% to 15 wt.%, 5 wt.% to 15 wt.%, 5 wt.% to 10 wt.%, or 7 wt.% to 15 wt.% of the total amount of the fdm layer and the film layer is extruded using a twin screw extruder to mix polyurethane resin and the release agent together.

[0066] In some cases, the substrate on which the fdm layer is extruded is a carrier material, as described in detail above with respect to the carrier frame. In other cases, the substrate is a paper or polymer film. Optionally, the substrate is a release liner, as described in detail above. Exemplary Embodiments

[0067] In a first embodiment, the present disclosure provides a film layer. The film layer comprises a polyurethane film and a release agent distributed in the polyurethane film.

[0068] In a second embodiment, the present disclosure provides a film layer according to the first embodiment, wherein the release agent is present in an amount of 1 weight percent (wt.%) to 15 wt.% of the total amount of the film layer.

[0069] In a third embodiment, the present disclosure provides a film layer according to the first embodiment or the second embodiment, wherein the release agent is selected from the group consisting of polyvinyl N-alkyl carbamates, polyvinyl N-alkyl carbamides, poly alkyl(meth)acrylate copolymers, silicone polyurea segmented copolymers, and siloxane-acrylate block copolymers.

[0070] In a fourth embodiment, the present disclosure provides a film layer according to any of the first through third embodiments, wherein the release agent is polyvinyl octadecyl carbamate.

[0071] In a fifth embodiment, the present disclosure provides a film layer according to any of the first through fourth embodiments, wherein the polyurethane film transmits moisture vapor at a rate of at least 300 g / m2 / 24 hrs / 37° C. / 100-10% RH, using the inverted cup method.

[0072] In a sixth embodiment, the present disclosure provides an article. The article comprises a substrate having a major surface and a film layer according to any of the first through fifth embodiments disposed on at least a portion of the major surface of the substrate.

[0073] In a seventh embodiment, the present disclosure provides an article according to the sixth embodiment, wherein the substrate comprises a sheet of paper or polymeric film.

[0074] In an eighth embodiment, the present disclosure provides an article according to the sixth embodiment or the seventh embodiment, wherein the release agent blooms to a surface of the film layer opposite the substrate.

[0075] In a ninth embodiment, the present disclosure provides an article according to any of the sixth through eighth embodiments, having a form of a surgical drape, a surgical tape, a suture strip or sheet, an adhesive dressing, a bandage, or a plaster. In a tenth embodiment, the present disclosure provides a tape. The tape comprises a substrate having a first major surface and a second major surface; a layer of an adhesive disposed on at least a portion of the first major surface of the substrate; and a film layer disposed on the layer of adhesive opposite the substrate. The film layer comprises a polyurethane film and a release agent distributed in the polyurethane film.

[0076] In an eleventh embodiment, the present disclosure provides a tape according to the tenth embodiment, wherein the substrate comprises a release liner.

[0077] In a twelfth embodiment, the present disclosure provides a tape according to the tenth embodiment or the eleventh embodiment, wherein the release agent is present in an amount of 1 weight percent (wt.%) to 15 wt.% of the total amount of the film layer.

[0078] In a thirteenth embodiment, the present disclosure provides a tape according to any of the tenth through twelfth embodiments, wherein the adhesive comprises an acrylate copolymer pressure sensitive adhesive or a silicone pressure sensitive adhesive.

[0079] In a fourteenth embodiment, the present disclosure provides a tape according to any of the tenth through thirteenth embodiments, wherein the release agent is selected from the group consisting of polyvinyl N-alkyl carbamates, polyvinyl N-alkyl carbamides, poly alkyl(meth)acrylate copolymers, silicone polyurea segmented copolymers, and siloxane-acrylate block copolymers.

[0080] In a fifteenth embodiment, the present disclosure provides a tape according to any of the tenth through fourteenth embodiments, wherein the release agent is polyvinyl octadecyl carbamate.

[0081] In a sixteenth embodiment, the present disclosure provides a tape according to any of the tenth through fifteenth embodiments, wherein the polyurethane film transmits moisture vapor at a rate of at least 300 g / m2 / 24 hrs / 37° C. / 100-10% RH.

[0082] In a seventeenth embodiment, the present disclosure provides a wound dressing. The wound dressing comprises a substrate having a first major surface and a second major surface and a layer of an adhesive disposed on at least a portion of the first major surface of the substrate. The wound dressing further comprises a film layer disposed on the layer of adhesive opposite the substrate and a carrier frame disposed on a periphery of the film layer. The film layer comprises a polyurethane film and a release agent distributed in the polyurethane film.

[0083] In an eighteenth embodiment, the present disclosure provides a wound dressing according to the seventeenth embodiment, wherein the layer of adhesive is discontinuous.

[0084] In a nineteenth embodiment, the present disclosure provides a wound dressing according to the seventeenth embodiment or the eighteenth embodiment, wherein the carrier frame is removable from the wound dressing. In a twentieth embodiment, the present disclosure provides a wound dressing according to any of the seventeenth through nineteenth embodiments, further comprising a writable surface attached to the film layer.

[0085] In a twenty-first embodiment, the present disclosure provides a wound dressing according to any of the seventeenth through twentieth embodiments, wherein the release agent is present in an amount of 1 wt.% to 15 wt.% of the total amount of the film layer.

[0086] In a twenty-second embodiment, the present disclosure provides a wound dressing according to any of the seventeenth through twenty -first embodiments, wherein the adhesive comprises an acrylate copolymer pressure sensitive adhesive or a silicone pressure sensitive adhesive.

[0087] In a twenty-third embodiment, the present disclosure provides a wound dressing according to any of the seventeenth through twenty-second embodiments, further comprising a design printed on the film layer.

[0088] In a twenty -fourth embodiment, the present disclosure provides a wound dressing according to any of the seventeenth through twenty -third embodiments, wherein the release agent is selected from the group consisting of polyvinyl N-alkyl carbamates, polyvinyl N-alkyl carbamides, poly alkyl(meth)acrylate copolymers, silicone polyurea segmented copolymers, and siloxane-acrylate block copolymers.

[0089] In a twenty -fifth embodiment, the present disclosure provides a wound dressing according to any of the seventeenth through twenty -fourth embodiments, wherein the release agent is polyvinyl octadecyl carbamate.

[0090] In a twenty-sixth embodiment, the present disclosure provides a wound dressing according to any of the seventeenth through twenty -fifth embodiments, wherein the polyurethane fdm transmits moisture vapor at a rate of at least 300 g / m2 / 24 hrs / 37° C. / l 00-10% RH.

[0091] In a twenty-seventh embodiment, the present disclosure provides a wound dressing according to any of the seventeenth through twenty-sixth embodiments, wherein the substrate comprises a release liner.

[0092] In a twenty -eighth embodiment, the present disclosure provides a method of making an article. The method comprises extruding onto a major surface of a substrate a film layer comprising a polyurethane and a release agent distributed in the polyurethane film.

[0093] In a twenty -ninth embodiment, the present disclosure provides a method according to the twenty-eighth embodiment, wherein the release agent is present in an amount of 1 wt.% to 5 wt.% of the total amount of the film layer and wherein the film layer is extruded using a single screw extruder. In a thirtieth embodiment, the present disclosure provides a method according to the twenty -ninth embodiment, wherein the single screw extruder comprises a screw having a mixing element.

[0094] In a thirty -first embodiment, the present disclosure provides a method according to the twenty-eighth embodiment, wherein the release agent is present in an amount of 1 wt.% to 15 wt.% of the total amount of the film layer and wherein the film layer is extruded using a twin screw extruder to mix polyurethane resin and the release agent together.

[0095] EXAMPLES

[0096] The following Examples are merely for illustrative purposes and are not meant to be overly limiting on the scope of the appended claims. Unless otherwise noted or otherwise apparent from the context, all parts, percentages, ratios, and the like in the Examples and the rest of the specification are provided on the basis of weight.

[0097] Materials Used in the Examples

[0098] Polyurethanes:

[0099] ESTANE® 58309 TPU from Lubrizol Advanced Materials, Inc. (Cleveland, OH).

[0100] ESTANE® 58237 TPU from Lubrizol Advanced Materials, Inc.

[0101] Release agent:

[0102] Escoat P-20 Solids from Mayzo (Suwanee, GA)

[0103] Release paper:

[0104] Y 05501 double side polypropylene coated kraft, matt / matt from Felix Schoeller (Osnabrtick, Germany).

[0105] Examples

[0106] Single screw extrusion examples

[0107] Polyurethane (PU) pellets were pre-dried at 80 degrees Celsius (C) overnight, then extruded by a conventional single screw extruder with either a conventional single screw or a unique single screw that has a mixing element. In these examples, we used a 45 mm single screw at 185-190 degrees C. We cast the PU film on release paper.

[0108] Twin screw extrusion examples

[0109] PU pellets were pre-dried at 80 degrees C overnight, then extruded by a conventional twin screw extruder from Coperion (Stuttgart, Germany). In these examples, we used a 25 mm twin-screw at 185-190 degrees C. We cast the PU film on release paper.

[0110] Cast PU film observation

[0111] When cast PU film on paper, we observe the cast film appearance for each sample.

[0112] Very Good: Cast film looked smooth, no voids.

[0113] Good: Few small voids were observed. Not Good: Cast film had voids.

[0114] Test methods PU films were tested for tensile strength and elongation percent (T&E). A Zwick Universal

[0115] Tabletop Tensile Tester, Model Z005 (Zwick USA, Kennesaw, GA) was used to measure the tensile properties based on ASTM D882 and ASTM D3759. Test sample size: 1 inch (2.54 cm) wide by 25 mm long. Gauge length: 1 inch (2.54 cm) with crosshead speed of 10 inches (25.4 cm) / min. Test specimens were squarely tabbed crosswise at each end with a 1 inch (2.54 cm) wide piece of tabbing tape overlapped once in such a way as to leave only the specified gauge length exposed and leave the ends of the tape tabs outside of the jaw faces. Example Test Results

[0116] Release agent blended polyurethane (PU) films had similar physical characteristics with nonrelease material blended PU films. It means that the release agent blended PU film can be used as same as typical PU films that do not contain any release agent.

[0117] Although specific embodiments have been illustrated and described herein, it will be appreciated by those of ordinary skill in the art that a variety of alternate and / or equivalent implementations can be substituted for the specific embodiments shown and described without departing from the scope of the present disclosure. This application is intended to cover any adaptations or variations of the specific embodiments discussed herein. Therefore, it is intended that this disclosure be limited only by the claims and the equivalents thereof. Furthermore, all publications and patents referenced herein are incorporated by reference in their entirety to the same extent as if each individual publication or patent was specifically and individually indicated to be incorporated by reference. In the event of inconsistencies or contradictions between portions of the incorporated references and this application, the information in the preceding description prevails.

Claims

What is claimed is:

1. A film layer comprising a polyurethane film; and a release agent distributed in the polyurethane film.

2. The film layer of claim 1, wherein the release agent is present in an amount of 1 weight percent (wt.%) to 15 wt.% of the total amount of the film layer.

3. The film layer of claim 1 or claim 2, wherein the release agent is selected from the group consisting of polyvinyl N-alkyl carbamates, polyvinyl N-alkyl carbamides, poly alkyl(meth)acrylate copolymers, silicone polyurea segmented copolymers, and siloxaneacrylate block copolymers.

4. The film layer of any of claims 1 to 3, wherein the release agent is polyvinyl octadecyl carbamate.

5. The film layer of any of claims 1 to 4, wherein the polyurethane film transmits moisture vapor at a rate of at least 300 g / m2 / 24 hrs / 37° C. / 100-10% RH, using the inverted cup method.

6. An article comprising a substrate having a major surface; and the film layer of any of claims 1 to 5 disposed on at least a portion of the major surface of the substrate.

7. The article of claim 6, wherein the substrate comprises a sheet of paper or polymeric film.

8. The article of claim 6 or claim 7, wherein the release agent blooms to a surface of the film layer opposite the substrate.

9. The article of any of claims 6 to 8, having a form of a surgical drape, a surgical tape, a suture strip or sheet, an adhesive dressing, a bandage, or a plaster.

10. A tape comprising: a substrate having a first major surface and a second major surface; a layer of an adhesive disposed on at least a portion of the first major surface of the substrate; and a film layer disposed on the layer of adhesive opposite the substrate, wherein the film layer comprises a polyurethane film and a release agent distributed in the polyurethane film.

11. The tape of claim 10, wherein the substrate comprises a release liner.

12. The tape of claim 10 or claim 11, wherein the release agent is present in an amount of 1 weight percent (wt.%) to 15 wt.% of the total amount of the film layer.

13. The tape of any of claims 10 to 12, wherein the adhesive comprises an acrylate copolymer pressure sensitive adhesive or a silicone pressure sensitive adhesive.

14. The tape of any of claims 10 to 13, wherein the release agent is selected from the group consisting of polyvinyl N-alkyl carbamates, polyvinyl N-alkyl carbamides, poly alkyl(meth)acrylate copolymers, silicone polyurea segmented copolymers, and siloxaneacrylate block copolymers.

15. The tape of any of claims 10 to 14, wherein the release agent is polyvinyl octadecyl carbamate.

16. The tape of any of claims 10 to 15, wherein the polyurethane film transmits moisture vapor at a rate of at least 300 g / m2 / 24 hrs / 37° C. / 100-10% RH.

17. A wound dressing comprising: a substrate having a first major surface and a second major surface; a layer of an adhesive disposed on at least a portion of the first major surface of the substrate; a film layer disposed on the layer of adhesive opposite the substrate, wherein the film layer comprises a polyurethane film and a release agent distributed in the polyurethane film; and a carrier frame disposed on a periphery of the film layer.

18. The wound dressing of claim 17, wherein the layer of adhesive is discontinuous.

19. The wound dressing of claim 17 or claim 18, wherein the carrier frame is removable from the wound dressing.

20. The wound dressing of any of claims 17 to 19, further comprising a writable surface attached to the film layer.

21. The wound dressing of any of claims 17 to 20, wherein the release agent is present in an amount of 1 wt.% to 15 wt.% of the total amount of the film layer.

22. The wound dressing of any of claims 17 to 21, wherein the adhesive comprises an acrylate copolymer pressure sensitive adhesive or a silicone pressure sensitive adhesive.

23. The wound dressing of any of claims 17 to 22, further comprising a design printed on the film layer.

24. The wound dressing of any of claims 17 to 23, wherein the release agent is selected from the group consisting of polyvinyl N-alkyl carbamates, polyvinyl N-alkyl carbamides, poly alkyl(meth)acrylate copolymers, silicone polyurea segmented copolymers, and siloxaneacrylate block copolymers.

25. The wound dressing of any of claims 17 to 24, wherein the release agent is polyvinyl octadecyl carbamate.

26. The wound dressing of any of claims 17 to 25, wherein the polyurethane film transmits moisture vapor at a rate of at least 300 g / m2 / 24 hrs / 37° C. / 100- 10% RH.

27. The wound dressing of any of claims 17 to 26, wherein the substrate comprises a release liner.

28. A method of making an article, the method comprising: extruding onto a major surface of a substrate a film layer comprising a polyurethane; and a release agent distributed in the polyurethane film.

29. The method of claim 28, wherein the release agent is present in an amount of 1 wt.% to 5 wt.% of the total amount of the film layer and wherein the film layer is extruded using a single screw extruder.

30. The method of claim 29, wherein the single screw extruder comprises a screw having a mixing element.

31. The method of claim 28, wherein the release agent is present in an amount of 1 wt.% to 15 wt.% of the total amount of the film layer and wherein the film layer is extruded using a twin screw extruder to mix polyurethane resin and the release agent together.

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