MULTILAYER FILM STRUCTURES INCLUDING A POLYESTER ELASTOMER LAYER AND A THERMOPLASTIC POLYURETHANE LAYER

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This Application claims the benefit of United States Provisional Patent Application Serial No. 61/481,555, titled Multilayer Film Structures Including a Polyester Elastomer Layer and A Thermoplastic Polyurethane Layer, filed May 2, 2011, which is hereby incorporated herein by reference.

BACKGROUND OF THE INVENTION

1. The Field of the Invention

[0002] The present disclosure relates to polymeric structures, including but not limited to thin films and flexible tubing.

2. The Relevant Technology

[0003] An important aim of the ongoing research in flexible polymer films and tubing is to provide a high-strength, transparent, sterilizable, disposable, leak-free, inert packaging, and/or tubing for pharmaceutical and biological fluids and other applications.

[0004] Desired attributes of polymer films used in the fabrication of flexible disposable containers, bags, tubing and connectors include all or a portion of the following: ability to seal; clarity; resistance to stress whitening; flexibility; durability, toughness; tear resistance, puncture resistance; non-tackiness; antistatic; chemical inertness; gas and moisture impermeability; and resistance to change during sterilization.

[0005] In order to produce materials with the foregoing properties in desired quantities, the polymer films should also be suitable for processing using existing equipment (both in manufacturing the film and converting the film into a container). Additionally, flexible thermoplastic-elastomeric barrier films used to form disposable containers for packaging of high-grade materials, such as pharmaceutical raw materials and pharmaceutical products, should be essentially free of leachable and extractable material to avoid contamination of the stored material.

[0006] Polymeric films can be quite simple in structure. However, there are thousands of different materials that can be assembled in many different ways to make such structures. Despite the simplicity of the structures, it can be very difficult to know what materials can be joined together to produce a film that satisfies the requisite criteria for making a usable film structure. Firstly, the properties of the overall structure depend on the bonding and other mechanical and chemical behaviors of adjacent layers in the multilayer structure. A material that produces a benefit in one particular configuration can lack the same benefits in another configuration and/or have a detrimental effect on one or more of the essential criteria for a desired film or tubing. The converse is also true; a material that does not produce a particular benefit when used in one structure may have a synergistic benefit in a different configuration. In many cases, even if one of skill in the art would know that two materials could be used to make a film structure, the skilled artisan would not know if the film structure would have sufficiently good adhesion or other properties to be useful for any particular application. For these and other reasons, the selection and configuration of multilayer polymeric structures to produce useful products can be inherently unpredictable and difficult.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Various embodiments of the present invention will now be discussed with reference to the appended drawings. It is appreciated that these drawings depict only typical embodiments of the invention and are therefore not to be considered limiting of its scope.

[0008] Figure 1 is a cross-sectional view of a multilayer film according to one embodiment of the present invention;

[0009] Figure 2 is a cross-sectional view of an alternative multilayer film according to the present invention;

[0010] Figure 3 is a cross-sectional view of another alternative multilayer film according to the present invention;

[0011] Figure 4 is a cross-sectional view of a thin film according to the present invention;

[0012] Figure 5A is a longitudinal cross-sectional view of tubing made from a film structure according the present invention; and

[0013] Figure 5B is a transverse cross sectional view of the tubing of Figure 5 A.

DETAILED DESCRIPTION

I. Introduction and Definitions [0014] The present invention relates to polymeric, multilayer, film structures that include a polyester elastomer layer and a thermoplastic polyurethane layer (hereinafter "TPU"). The polyester elastomers are copolymers of a polyester and an elastomer (hereinafter "COPE"). Multilayer film structures that include COPE and TPU have been found to have good properties for use in making thin film bags, containers, and flexible tubing. In particular, the polyester elastomer layer is particularly useful as the outer contact layer of the film structures (although its position as the outer contact layer is not required). The film structures may also include one or more additional layers, such as, but not limited to, a gas barrier layer and/or a fluid contact layer.

[0015] Surprisingly, it has been found that TPU provides excellent adhesions to COPE and between COPE layers and other layers such as, but not limited to a gas barrier layer made from EVOH and/or a fluid contact layer made from a melt processable fluoropolymer (e.g., PVDF or PVDF copolymers). The ability of TPU to provide excellent bonding between COPE and other materials such as EVOH and/or melt processable fluoropolymer, while imparting good mechanical and chemical properties to the material, while improving processability, is a surprising and unexpected result. In addition, the multilayer film structures have also been found to be highly recyclable.

[0016] In some embodiments, the multilayer film structures can be a clear, flexible bag used to hold pharmaceutical raw materials and/or pharmaceutical products. In one embodiment, the inventive multilayer film structure has improved product integrity as a result of low or extremely low water vapor transmission rates and/or low or extremely low oxygen transmission rates. Further, in one embodiment, the multilayer film may have a broader chemical resistance, improved levels of leachables and extractable materials, improved levels of nonspecific protein and lipid absorption, and/or reduced particle shedding.

[0017] The term "disposable" as used herein means, any item designed for or capable of being disposed of after use, whereas use may be a one-time or multiple use as required by the pertinent industry manufacturing process without the need to sterilize the entire disposable container more than one time.

[0018] The term "packaging" as used herein, is not limited to the specifically enclosed embodiments. Packaging, as used herein, includes physical containment of materials and products, protection of contained materials and product from environmental ingress and protection of the environment and operators from egress of contained materials and product.

[0019] The phrase "gas barrier" as used herein refers to a barrier that at least significantly restrains gas passage but may or may not completely block gas passage.

[0020] The phrase "essentially free of leachable and extractable materials," as used herein, means there is either no leachable or extractable material in the flexible multilayer film used to form disposable containers or the amount of leachable and extractable material is so low as to not adversely affect the stored or processed product.

[0021] The phrase "essentially chemically inert," as used herein, means that the film or polymeric structure is, as per the required concentration and temperature, chemically compatible with and resistant to the products stored therein (e.g., pharmaceutical raw materials and pharmaceutical products stored).

[0022] The phrase "essentially does not shed particles", as used herein, means that the multilayer film used to form polymeric structures does not shed particles or that the amount of shed particles is so low as to not adversely affect the stored or product being processed.

[0023] The phrase "pharmaceutical raw materials" as used herein, is not limited to the specifically enclosed embodiments. By way of example, pharmaceutical raw materials, as used herein, can include raw and in-process biological fluids such as culture media and nutritional components; buffers; aqueous solutions and salt solutions or combinations thereof of varying pH, such as those used in dialysis, chromatography, crystallization, purification; processing solutions composed of either acids, alkali or antifoam agents; water; sanitizing and cleaning detergents; chaotropic solutions and buffers of varying pH for protein refolding, adjuvants, biological materials such as cells, cell debris, cellular components, viruses, antigens; and aliphatic and aromatic organic solvents, such as those used in chemical synthesis, chromatography, crystallization, and extraction.

[0024] The phrase "pharmaceutical products" as used herein, is not limited to the specifically enclosed embodiments. By way of example, pharmaceutical products, as used herein, can include pharmaceutical and biological intermediate, bulk, purified, formulated and final manufactured products. II. Materials for Making Multilayer Film Structure

[0025] The multilayer film structures described herein can have two or more layers. The film structures can include 2, 3, 4, 5, 6 or more layers adhered together. Tie layers and adhesive layers may be part of the structure, or the different layers may adhere together without tie-layers of adhesives. Figure 1 illustrates an example five layer structure 100 that includes an outer contact layer 110, a gas barrier layer 120, a fluid contact layer 130, a first tie layer 140 disposed between layers 110 and 120, and a second tie layer 150 disposed between layers 120 and 130. The outer contact layer 110 is the layer that forms the outside surface of a part such as a container, bag or tubing made from the film. Fluid contact layer 130 forms the inside surface of the part and may be the layer that is configured to contact fluids (e.g., biological fluids).

[0026] The multilayer film structures can be a two dimensional structure such as a thin film (i.e., sheets where the thickness of the sheet is orders of magnitude smaller than the length or width of the sheet) or the structures can be formed into three dimensional shapes including, but not limited to containers, bags, and/or flexible tubing.

[0027] The multilayer films of the invention include at least one layer of a COPE material (also referred to herein as a polyester elastomer layer). The COPE layer can be any layer in the film structure, but is preferably the outer contact layer, such as layer 110. COPE can make a good outer contact layer because of its tactile feel and its high water vapor transmission rate. A COPE outer contact layer is particularly advantageous when used in combination with a gas barrier layer, such as layer 120, to keep the gas barrier layer dry. The use of a COPE outer layer can allow for very thin films, when desired. In one embodiment, the COPE layer has a thickness in a range from 0.1-20 mils (2.5-508 μπι), 0.5- 5 mils (12.7-127 μπι), or 1.0-3.0 mils (25.4-76.2 μιη). The foregoing thicknesses may be useful for making thin films such as bags. Alternatively, for making thicker structures such as flexible tubing, the COPE layer may have a thickness in a range from 0.5-225 mils (12.7-5715 μιη) , 5-175 mils (127- 4445 μιη), or 25-150 mils (635-3810 μιη). The COPE layer may be selected to be a desired percentage of the overall thickness of the structure. In one embodiment, the COPE layer is 1-75% of the overall thickness of the structure, alternatively 10-25% of the thickness of the film structure. [0028] The COPE is made from a dicarboxylic acid that is polymerized with another component, such as, but not limited to, a diol that can impart elastomeric properties to the copolymer. The COPE may be derived from a dicarboxylic acid component such as 1 ,4-cyclohexanedicarboxylic acid or an ester forming derivative thereof such as dimethyl- 1 ,4-cyclohexanedicarboxylate ester ethers. Additional compounds that can be used include, but are not limited to 1 ,4-cyclohexanedimethanol (CHDM) or a polytetramethylene ether glycol (PTMG). The polyester elastomers may also include from about 0.1 to about 1.5 mole %, based on the acid or glycol component, of a polyfunctional branching agent having at least 3 carboxyl or hydroxyl groups. Additional examples of polyester elastomers can be found in U.S. Patent No. 4,349,469, which is incorporated herein by reference.

[0029] In addition to the COPE layer, the film structures also include a thermoplastic polyurethane (TPU) layer. The TPU layer may be used as a contact layer, such as layer 130, an intermediate layer, and/or a tie layer, such as layers 140 and 150, and may be placed in any position in the film structure. In some embodiments, the TPU layer serves as a tie layer between the COPE layer and another layer in the structure. For example, the TPU layer can join the COPE layer to a gas barrier layer (e.g., EVOH) or a fluid contact layer (e.g., PVDF). The TPU layer can have a thickness in a range from 0.1-10 mils (2.5-254 μιη), 0.3-5 mils (7.6-127 μιη), or 1.0-2.5 mils (25.4-63.5). These ranges can be useful for making thin films such as bags. Alternatively, for making thicker structures such as flexible tubing the thickness may be in a range from 0.5-225 mils (12.7-5715 μπι) , 5-175 mils (127-4445 μπι), or 25-150 mils (635-3810 μπι)

[0030] There are various TPU materials that can be used, including TPU copolymers made from aliphatic or aromatic isocyanates, and polyester or polyether polyols. The type of polyols and isocyanates determine the final properties of the TPU copolymer. In one embodiment, the TPU copolymer may be an aromatic isocyanate polyester polyol based TPU copolymer with specific gravity of from about 1.10 to about 1.21 and having good clarity and tensile strength, resistant to change during sterilization by gamma (γ) irradiation, biological compatibility, and essentially free of leachable and extractable materials. Examples of suitable TPU based materials include, but are not limited to Noveon Estane® 58271, Noveon Estane® 58238, BASF Elastollan® 688A10N and BASF Elastollan® 685A10N and Elastollan C85, Pellethane® from The Dow Chemical Company, Texin® from Bayer MaterialScience, and Elastollan® 600 and 1100 series from BASF, and especially TPU copolymers with a Shore A hardness between about 76 and about 91].

[0031] The use of TPU with COPE has surprisingly been found to make the COPE layer more easily processable (i.e., formed into a film structure). For example, COPE layers that were extrusion blown to form a thin film can more easily form a bubble when COPE is used in conjunction with TPU. This result is surprising and unexpected at least in part because COPE and TPU are both elastomeric copolymers and therefore have similar properties. Thus, the use of TPU and COPE together would not be expected to have significant impact on processability. In addition, it has been found that TPU can be used as a tie layer to adhere COPE to other layers such as EVOH and PVDF.

[0032] Although both polyether and polyester polyol based TPU copolymers are disclosed, a polyester polyol based TPU copolymer may be preferred according to various embodiments of the present invention. It is believed, that a polyester polyol based TPU copolymer provides better adhesion to melt processable fluoropolymers and/or COPE. It is also believed, that a polyester polyol based TPU copolymer provides better clarity results.

[0033] Additional details regarding adhesion between PVDF and TPU is disclosed in U.S. Patent Publication No. US2008/0199645, which is hereby incorporated herein by reference for its teaching of TPU and melt processable fluoropolymer such as PVDF and PVDF copolymers.

[0034] In some embodiments of the invention, a gas barrier layer such as layer 120 can be provided in the film to minimize or otherwise provide resistance to transmission of gases, such as water vapor, oxygen and carbon dioxide through the film structure. The gas barrier layer may be a contact layer or an inner layer, but is typically an inner layer, positioned between the outer contact layer and the fluid contact layer. In one embodiment the gas barrier layer has several specific attributes including clarity, flexibility, biological compatibility and/or resistance to change during sterilization by gamma (γ) irradiation.

[0035] The gas barrier layer can have extremely low water vapor transmission rates (WVTR). In one embodiment, the gas barrier layer (or the film structure including the gas barrier layer) has a WVTR lower than 0.1 g/100 in /24 h gas as determined by ASTM F1249 test standard measured at 23 °C and 100% RH on the test gas side and 0% RH on the carrier gas side.

[0036] Similarly, the gas barrier layer may have an extremely low oxygen transmission rate (OTR). The gas barrier layer (or the film structures including the gas barrier layer may have an OTR lower than 0.1 cc/100 in /24h as determined by ASTM F1927 test standard measured at 23 °C and 50% RH on the test gas side and 100% RH on the carrier gas side.

[0037] The gas barrier layer may have a thickness ranging from about 1% to about 35% of the total thickness of multilayer film structure or alternatively ranging from about 5% to about 15% of the total thickness.

[0038] The material used for the gas barrier layer may be an ethylene vinyl acetate- vinyl alcohol copolymer (EVOH). In one embodiment, the EVOH of gas barrier layer includes about 25 mol% to about 45 mol% ethylene vinyl acetate (EVA) copolymer. In another embodiment, the EVOH copolymer used may have a melt flow rate of about 3.7 to about 5 g/10 min. Examples of materials with such characteristics include commercially available EVAL h series made by Kuraray and Soarnol 3803 made by Nippon Gohsei. Examples of materials other than EVOH that can be used as a barrier layer include, but are not limited to polyvinylidene chloride (PVDC) and resins that include nanoparticles.

[0039] The fluid contact layer may be made from a polymeric material suitable for contact with a particular fluid. In some embodiments, the fluid contact layer may be a melt processable fluoropolymer, although other materials may be used and the fluoropolymer may be used in other layers within the multilayer film structure. In a preferred embodiment, the fluoropolymer layer will be the layer in contact with the media or fluid to minimize absorption of lipids.

[0040] The fluoromonomer (also referred to as fluorinated monomer) may be a polymerizable alkene which contains at least one fluorine atom, fluoroalkyl group, or fluoroalkoxy group attached to the double bond of the alkene that undergoes polymerization. The term "fluoropolymer" includes polymers formed by the polymerization of at least one fluoromonomer, including homopolymers, copolymers, terpolymers and higher polymers which are thermoplastic in nature, meaning they are capable of being formed into useful pieces by flowing upon the application of heat, such as is done in molding and extrusion processes. Fluoropolymers useful in the present invention are those that are melt processable. Examples of fluoropolymers that are melt processable include, but are not limited to, polyvinylidene fluoride and its copolymers (PVDF and co-PVDF), ethylene tetrafluoro ethylene (ETFE), ethylene chlorotrifluoroethylene (ECTFE), fluorinated ethylene propylene (FEP), tetrafluoroethylene-perfluorovinyl propyl ether (PFA), and any combination of monomers where at least one of them is fluorinated. These could also include EFEP (ethylene, hexafluoropropylene, tetrafluoroethylene), PVDF copolymerized with hexaf uoropropylene, perf uorovinyl methyl or propyl ether, ethylene, tetrafluoroethylene, vinyl fluoride, vinyl trifluoride, ethylene, etc., as well as functional monomers such as maleic anhydride, glycidyl methacrylate, etc.

[0041] Preferred fluoropolymers are made by polymerizing vinylidene fluoride (VDF), and copolymers, terpolymers and higher polymers of vinylidene fluoride wherein the vinylidene fluoride units comprise greater than 70 percent of the total weight of all the monomer units in the polymer, and more preferably, comprise greater than 75 percent of the total weight of the units. In one embodiment, the at least one PVDF layer is 100 percent PVDF, and not blended with another polymer.

[0042] Copolymers, terpolymers and higher polymers of vinylidene fluoride may be made by reacting vinylidene fluoride with one or more monomers from the group consisting of vinyl fluoride, trifluoroethene, tetrafluoroethene, one or more of partly or fully fluorinated alpha-olefms such as 3,3,3-trifluoro-l-propene, 1,2,3,3,3- pentafluoropropene, 3,3,3,4,4-pentafluoro-l-butene, and hexafluoropropene, the partly fluorinated olefin hexafluoroisobutylene, perfluorinated vinyl ethers, such as perfluoromethyl vinyl ether, perfluoroethyl vinyl ether, perfluoro-n-propyl vinyl ether, and perfluoro-2-propoxypropyl vinyl ether, fluorinated dioxoles, such as perfluoro(l,3- dioxole) and perfluoro(2,2-dimethyl-l,3-dioxole), allylic, partly fluorinated allylic, or fluorinated allylic monomers, such as 2 -hydroxy ethyl allyl ether or 3- allyloxypropanediol, and ethene or propene. Preferred copolymers or terpolymers are formed with vinyl fluoride, trifluoroethene, tetrafluoroethene (TFE), and hexafluoropropene (HFP). [0043] Preferred copolymers are of VDF comprising from about 71 to about 99 weight percent VDF, and correspondingly from about 1 to about 29 percent TFE; from about 71 to 99 weight percent VDF, and correspondingly from about 1 to 29 percent HFP (such as disclosed in U.S. Pat. No. 3,178,399); and from about 71 to 99 weight percent VDF, and correspondingly from about 1 to 29 weight percent trifluoroethylene.

[0044] Preferred terpolymers are the terpolymer of VDF, HFP and TFE, and the terpolymer of VDF, trifluoroethene, and TFE, The especially preferred terpolymers have at least 71 weight percent VDF, and the other comonomers may be present in varying portions, but together they comprise up to 29 weight percent of the terpolymer.

[0045] The polyvinylidene fluoride could also be a functionalized PVDF, produced by either copolymerization or by post-polymerization functionalization. Some fluoropolymers are less preferred due to their poor melt processability, examples include, propylene chlorotrifluoroethylene (PCTFE) and polytetrafluoroethylene, and the like.

[0046] In addition to the fluoropolymer layer(s) in the multilayer film, other polymer layers, tie layers and adhesive layers may be present. Some particularly useful layers include, but are not limited to, polyolefms such as polyethylene (PE), including linear low density polyethylene (LLDPE), low density polyethylene (LDPE), medium density polyethylene (MDPE), polypropylene (PP), and functional polyolefms (FPO) containing grafted or reacted functional groups such as maleic anhydride or glycidal methacrylate; ethylene vinyl acetate (EVA); polyamides (PA); and high temperature polyolefms such as a 4-methyl pentene-1. Polyvinyl alcohol can also be used as a barrier layer in the multilayer structure.

[0047] The fluoropolymer layer can have a thickness in a range from 0.1-10 mils, 0.3-5 mils, or 1.0-2.5 mils. These ranges can be useful for making thin films such as bags. Alternatively, for making thicker structures such as flexible tubing the thickness may be in a range from 0.5-225 mils, 5-175 mils, or 25-150 mils.

[0048] The multilayer film structures can also include other layers of materials known in the art and used in known ways. For example, layers of polyolefms can be used. In addition, adhesives and/or other tie layers can also be used between one or more of the foregoing layers to provide desired adhesion. Adhesives and other bonding agents known in the art can also be used. III. Multilayer Film Structures

[0049] Set forth below are examples of a number of different multilayer film structures incorporating features of the present invention. It appreciated that the different layers discussed below can be made from the corresponding materials as discussed above.

[0050] Figure 2 illustrates a non-limiting example of a multilayer film structure 200 having two layers 210 and 220 made from COPE and TPU, respectively. In a preferred embodiment, the COPE layer 210 is directly adhered to and in contact with the TPU layer 220. Alternatively one or more additional layers or an adhesive can be disposed between COPE layer 210 and TPU layer 220. COPE layer 210 may be an outer contact layer and/or an inner layer and TPU layer 220 may be a fluid contact layer or an inner layer.

[0051] One or more additional layers, such as layer 240 may optionally be disposed on COPE layer 210 and one or more layers such as layer 230 may be disposed on TPU layer 220. In one non-limiting example, a bas-barrier layer is disposed on TPU layer 220 and can be directly or indirectly adhered.

[0052] Figure 3 illustrates an alternative multilayer film structure 300 that includes three layers. Layer 310 is made from COPE and layer 330 is made from a melt processable fluoropolymer (e.g., PVDF or PVDF copolymer). A layer 320 of TPU may be disposed between layer 330 and 310. In one embodiment, TPU layer 320 is in contact with and directly adheres to COPE layer 310 and/or melt processable layer 330, thereby joining the layers together. In an alternative embodiment, one or more additional layers or adhesives can be disposed between TPU layer 320 and COPE layer 310 or alternatively between TPU layer 320 and melt processable layer 330. Three layer structures can be used to make thin films or tubing. Three layer structures may typically be used where gas barrier properties are not needed. Such structures can be useful when making flexible tubing. Examples of three layer structures include, but are not limited to COPE/TPU/COPE and COPE/TPU/PVDF.

[0053] Figure 4 illustrates a five layer multilayer thin film structure 400. Structure 400 includes a contact layer 410 made from a COPE, a gas barrier layer 420 made from EVOH, and a fluid contact layer 430 made from a melt processable fluoropolymer (e.g., PVDF or PVDF copolymer). A tie layer 440 is disposed between layers 410 and 420 while tie layer 450 is disposed between layers 420 and 430. One or both of tie layers 440 and 450 are made from a polyester based TPU material. Alternatively, layer 440 may be a polyethylene tie layer. An example of a particular 5 layer structures that may be constructed according to the one embodiment of the invention includes COPE/TPU/EVOH/TPU/PVDF. Five layer structures are typically advantageous where gas barrier properties are desired. While flexible tubing may include 5 or more layers, the use of three layers for tubing is typically preferred.

[0054] The multilayer films of the invention have an overall thickness that will depend on the particular use of the film. For example, where a thin film is desired, the thickness may be in a range from 0.5-50 mils (0.012-1.2 mm), 1-20 mils (0.025-0.5 mm), or 5-10 mils (0.12 -0.25 mm). Where the film structure is configured as a flexible tubing, the overall thickness may be in a range from 10-300 mils (0.25-7.6 mm), 25-250 mils (.63-6.3 mm), or 50-200 mils (1.2-5 mm).

[0055] Figures 5A and 5B illustrate flexible tubing 500 having a wall 560 with an outer surface 550 and an inner surface 580. Inner surface 580 bounds a lumen 570 through which a fluid can be passed. Wall 560 is a thin film structure having multiple layers according to one embodiment of the invention. In the depicted embodiment, wall 560 has a three layer structure. Wall 560 includes an outer contact layer 510 made from a COPE, a fluid contact layer 530 made from a melt processable fluoropolymer (e.g., PVDF or PVDF copolymer), and a TPU layer 520 disposed between layer 510 and layer 530. The thickness of wall 560 depends on the difference between the outer and inner diameters of the tubing. In one embodiment, the outer diameter can be in a range from ¼ inch to 1.0 inch (6.3-25 mm) and the inner diameter may be in a range from 1/8 inch to 7/8 inch (3.1-22 mm). Examples of suitable tubing thicknesses include an outer diameter of ½ inch (12.7 mm) and an inner diameter of 3/8 (9.5 mm), or alternatively an outer diameter of 3/8 inch (9.5 mm)and an inner diameter of ¼ of an inch (6.3 mm). The selection of materials and thicknesses for wall 560 can be chosen to give the tubing a desired shore hardness. In one embodiment, the shore hardness of the flexible tubing is a shore hardness in a range from 40-80, 45-70, or 50-60. In addition, the flexible tubing may have a bend radius in a range from about 3/8 inch to 4 inch (9.5-101 mm), or 1 inch to 3 inch (25-76 mm) depending upon tubing construction and wall thickness. [0056] The configuration of the various layers of the film structure will depend upon the performance requirements of the application (barrier performance, flexibility, toughness, etc). For example, if the overall film is too thin, it may not provide the barrier properties or integrity needed, and if it is too thick, the ability to weld using conventional film welding techniques can be limited. The multilayer films may be autoclavable (steam sterilizable), and gamma sterilizable, as well as having high purity, high barrier performance, and high chemical resistance. The films can also be sterilized with radio frequency radiation. Since the sterilization can easily occur at the production site, manufacturers can have an option to assemble and steam sterilize their own system on site. This leads to decreased lead times and increased flexibility for the end user.

[0057] Since the multilayer films of the invention can be gamma sterilized, it also offers the end-user to qualify one system instead of two (one for steam sterilization and one for gamma sterilization).

[0058] In some embodiments, the multilayer films of the invention may have good heat sealability and flexibility not found with other film structures. For example, the films may have a large difference in melt temperature between the melting temperature of the outer contact layer as compared to the inner contact layer. This is particularly true where COPE provides the outer contact layer. The heat sealability property of the films may allow for the production of high strength joints in thin films such as bags.

[0059] The use of EVOH as a gas barrier layer and the use of PVDF or PVDF copolymer as the fluid contact layer can be particularly useful for storing and transporting biological fluids. The PVDF or PVDF copolymers used in the multilayer film structures can be used to form container, bags, and/or tubing that essentially does not absorb proteins and lipids, thereby avoiding loss of stored or processed product therein.

[0060] In addition, the multilayer film of the present invention may be used to form containers that can stretch and recover under changing or repeated loads such as loads from repeated filling and dispensing of fluids. The film is made to experience minimum fatigue and permanent set during transportation and shipping without flex cracking.

[0061] The containers or bags may include pillow, gusseted, conical, and/or cylindrically shaped bags formed from flexible film for collection, dispensing, storing, processing, and shipping of products, including, but not limited to, pharmaceutical raw materials and pharmaceutical products. The container or bag can be open at the top or can be closed. The container may include one or more access ports which can be located anywhere in the container. The interior volume of the container can be made to accommodate research and development scale operations or commercial production scale operations.

[0062] In one embodiment, a container may comprise a two-dimensional pillow style bag wherein two sheets of material are placed in overlapping relation and the two sheets are bonded together at their peripheries to form the internal compartment. Alternatively, a single sheet of material can be folded over and seamed around the periphery to form the internal compartment. In another embodiment, a container can be formed from a continuous tubular extrusion of polymeric material that is cut to length and is seamed closed at the ends.

[0063] In still other embodiments, a container can comprise a three-dimensional bag that not only has an annular side wall but also a two dimensional top end wall and a two dimensional bottom end wall. Three dimensional containers comprise a plurality of discrete panels, typically three or more, and more commonly four or six. Each panel is substantially identical and comprises a portion of the side wall, top end wall, and bottom end wall of the container. Corresponding perimeter edges of each panel are seamed. The seams are typically formed using methods known in the art such as heat energies, RF energies, sonics, or other sealing energies. In alternative embodiments, the panels can be formed in a variety of different patterns.

[0064] Typically the volume of the disposable container or bag will be at least 10 mL, but preferably at least 100 mL. However, sizes of the container ranging from 10 L to 10,000 L are also possible. Small containers can be used without support structure, while a rigid outer support structure can be used for larger containers. The containers may be disposable.

IV. Methods For Making Film Structures

[0065] The multilayer films can be formed by means known in the art. The multilayer films that can be produced by co-extrusion, lamination or some other process capable of producing these films. These can be produced by extrusion, cast film, blown film and oriented film followed by lamination. The use of tie layer to adhere layers may also be employed. V. Methods For Recycling Film Structures

[0066] The present invention also relates to methods for making recycled materials and parts from thin film structures according to the invention. One significant advantage of making multilayer film structures from COPE and TPU is that these two materials have been found to be recyclable to make an elastomeric material.

[0067] In one embodiment, the method includes providing a film structure including a layer of COPE and a layer of TPU. The film structure is compounded to form a mixture of the thin films in the structure (e.g., by extrusion). The compounded material can then be reprocessed, (e.g., by extrusion) to form a new film and/or an injection molded part.

VI. Examples

Example 1

[0068] Example 1 describes a multilayer structure including polyester elastomer (COPE) bonded to thermoplastic polyurethane (TPU). Multilayer blown film adhesion testing was performed between Eastman's Ecdel 9966 COPE and Lubrizol's Estane 58246 TPU. Three one inch single screw extruders fed a spiral mandrel blown film die to make a three layer blown film structure where the inside and outside layers were Ecdel 9966 COPE and the inside layer was Estane 58246 TPU. Table 1 below shows the processing conditions.

Table 1

[0069] Ecdel 9966 alone would form a stable bubble, but the addition of the Estane 58246 layer formed a more stable bubble. There was no delamination between the Ecdel 9966 and Estane 58246 materials.

Example 2

[0070] Example 2 describes a 5 layer structure having a polyester elastomer outer contact layer, and EVOH gas barrier layer, a PVDF fluid contact layer, and TPU tie layers. The materials and thicknesses are provided in Table 2 below: Outer contact layer COPE, Ecdel 9966 / 50 micron Cold temperature

Tie Layer TPU, Elastollan C85A10 / 12 micron profile (210°C) Gas Barrier Layer EVOH, EVAL 171b / 25 micron

Tie Layer TPU, Elastollan C85A10 / 12 micron

Fluid Contact Layer PVDF, Kynar Flex 2800-10. 50 micron

Table 2

[0071] To make a thin film a blown film line with line speed of 3.1 m/min and a blow up ratio of 2.55 with a die gap of 2 mm and single lip air ring was used. An inspection of the film confirmed that the adhesion between layers was good.

Example 3

[0072] Example 3 describes a process similar to Example 2, except that the process conditions were carried out at 230 °C instead of 210 °C. The thin film of Example 3 showed good adhesion.

Examples 4 and 5

[0073] Examples 4 and 5 describe sterile films produced from the films of Examples 2 and 3, respectively. The thin films of Examples 2 and 3 were die cut and placed into an autoclave and sterilized at 260°F for 30 minutes. The results showed that the sterilized films of Examples 4 and 5 had no signs of delamination nor did the sterilization step weaken the adhesion between the film layers.

Example 6

[0074] Example 6 describes physical testing of the thin film of Example 4. The thin film of Example 4 was tested for tensile, elongation, and graves tear in machine and transverse directions. The results are shown in Table 3 below.

Table 3

[0075] As shown from the results in Table, 3, the thin films including COPE and TPU layers exhibit excellent mechanical properties.

Example 7

[0076] Example 6 describes a method for making a recycled material using film structures of COPE and TPU. A 50/50 wt.% of Eastman's Ecdel 9966 COPE and BASF's Elastollan C85A10 TPU were pre-dried at 70°C over night and then compounded. Compounding was performed on a 18mm Leistritz co-rotating twin- screw extruder. The conditions used are show in Table 4 below.

Table 4

[0077] The compounded extrudate was opaque in appearance and elastic. The compounded extrudates was then examined using atomic force microscopy (AFM) and optical microscopy. AFM imaging showed mostly spherical domains of effective diameter ranging from 125nm to 2μιη. Few asymmetric domains were also identified.

Example 8

[0078] Example 8 describes a recycled part manufactured using the recycled material of Example 7. The recycled material of Example 7 was injection molded to form parts at the following conditions shown in Table 5 using a 75 -ton Arburg injection molding machine:

Table 5

[0079] The parts were then conditioned at 23°C with 50% RH over the weekend then mechanically tested using an Instron tensile machine for tensile, elongation, and flexural properties. The physical properties are shown below in table 6:

Table 6

Example 9

[0080] Example 9 describes a method for making a recycled material. The method was carried out on a thin film structure with the following composition: 14 wt% Eastman's Ecdel 9966 COPE, 43.6% BASF's Elastollan C85A10 TPU, 27.5 % EVOH, and 14.5% PVDF. Compounding was performed on a 18mm Leistritz co-rotating twin- screw extruder. The conditions used are show below in Table 7.

Table 7

[0081] The compounded extrudate was white and had sufficient melt strength.

Example 10

[0082] The recycled material of Example 9 was injection molded to make a part at the following conditions shown in Table 8 using a 75 -ton Arburg injection molding machine:

Table 8

[0083] The parts were then conditioned at 23°C with 50% RH over the weekend then mechanically tested using an Instron tensile machine for tensile, elongation, and flexural properties. The physical properties of the blend and original film are compared below:

Table 9

[0084] The present invention may be embodied in other specific forms without departing from its spirit or essential characteristics. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.