Orthopedic Packaging Materials

Abstract

The present invention provides a packaging material comprising a first layer formed of thermoplastic polyurethane (TPU) and a second layer formed of a heat-activated olefin-based polymer coupling agent, the coupling agent containing ethylene-vinyl acetate (EVA) copolymer and a second polar comonomer, wherein the packaging material has a total thickness of 2 mils (50µm) to 24 mils (600µm), the first layer has a thickness of 0.8 mils (20µm) to 16 mils (400µm), and the second layer has a thickness of 0.8 mils (20µm) to 8 mils (200µm). The packaging material of the present invention can be used to provide thermoformed containers and trays for storing sharp abrasive articles (e.g., orthopedic devices including bone implants).

Description

Field of the Invention

[0001] The present invention relates generally to packaging and, more particularly, to packaging materials for sharp abrasive articles such as bone implants. Background of the Invention

[0003] Bone implants have extremely sharp edges in order to be placed with minimal tolerance during surgery. Packaging of such sharp items is a challenge as the sharp edges create abrasive dust from contact and wear on the packaging material. Surgical implants are often packaged in bags made of plastic for transportation from the manufacturer to the hospital for implantation.

[0004] The exterior of such a bag must be durable enough to resist perforation, must exhibit adequate barrier properties to control the transmission of oxygen and moisture, and must resist contaminants such as bacteria. Tensile strength is necessary to resist bursting, tearing, and cutting over a wide temperature range. This can make the product resilient and is desirable for all applications where there is a risk of abrasion.

[0005] Composite structures made of established materials are known in the art. These structures are most commonly composed of PET-G to obtain rigidity and dimensionally stable, and a bag made of thermoplastic polyurethane to provide excellent surface wear stability.

[0006] Difficulties to overcome in the process of producing such packaging include, for example, the additional handling of PET-G blisters with separate bags, including the expanded input of raw materials. This leads to high manufacturing costs for the additional bags and high costs for manual packaging assembly. On the user side in the hospital, nurses / end users who must handle multiple items during surgery also face difficulties. Nested blister packaging provides some benefits, but the processing costs are still high. This is because two different materials and two different tools are required for thermoforming and deep drawing. The same problems also apply to PET-G blisters nested with alternative materials such as silicone. In either case, the risk of the implant slipping and damaging the package still exists.

[0007] Medical device packaging materials must also exhibit the appropriate barrier properties necessary to maintain the proper composition of the fluids that interact with these materials to ensure that oxygen, moisture, and potential contaminants cannot penetrate the film or tube. Regardless of the rigidity of the package, these packages must also have the durability to withstand the rigors and fast pace of the medical environment. Finally, medical device packaging should demonstrate a clear history of biocompatibility.

[0008] Multilayer medical packaging made of elastic TPU film combined with PET-G film is available in the art and has been used for packaging of bone implants. Examples are, for example, Covestro's BAYFOL MA502 or MA504 grades, which have shown excellent performance. Such structured films have higher strength and durability and have proven to be suitable for form-fill-seal (FFS) packaging on highly automated production lines.

[0009] Nevertheless, those skilled in the art continue to seek solutions that provide better adhesion between the various layers. They are looking for a combination of the economics of cheaper materials and the performance of technically superior materials.

[0010] There remains a need in the art for ways to overcome the shortcomings of adhesion between incompatible polymers. SUMMARY OF THE INVENTION

[0012] Thus, the present invention provides a composite film structure that improves the adhesion of thermoplastic polyurethane (TPU) to various target thermoforming materials intended for lamination. Such laminates can then be thermoformed into containers and trays for packaging abrasive sharp medical articles such as orthopedic devices including bone implants.

[0013] These and other advantages and benefits of the present invention will be apparent from the following detailed description of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will now be described, for purposes of illustration and not limitation, with reference to the accompanying drawings, in which:

[0016] Figure 1 A cross-sectional view of a packaging material of the present invention is shown. DETAILED DESCRIPTION OF THE INVENTION

[0018] The invention will now be described for purposes of illustration and not limitation.Except in the operating examples, or where otherwise indicated, all numerical values ​​expressing quantities, percentages, etc. in this specification are to be understood as being modified in all instances by the term "about".

[0019] Any numerical range described in this specification is intended to include all sub-ranges of the same numerical precision included in the range. For example, the range of "1.0 to 10.0" is intended to include all sub-ranges between the minimum value 1.0 and the maximum value 10.0 (including the end value), that is, the minimum value is equal to or greater than 1.0 and the maximum value is equal to or less than all sub-ranges of 10.0, such as 2.4 to 7.6. Any maximum numerical limit described in this specification is intended to include all lower numerical limits contained therein, and any minimum numerical limit described in this specification is intended to include all higher numerical limits contained therein. Therefore, the applicant reserves the right to modify this specification (including claims) to explicitly narrate any sub-range included in the scope clearly recorded herein. All these ranges are intended to be inherently described in this specification so that the modification of any such sub-range clearly recorded meets the requirements of 35 USC §112 (a) and 35 USC §132 (a). The various embodiments disclosed and described in this specification may include the features and characteristics described in various ways herein, be composed of the features and characteristics, or be substantially composed of the features and characteristics.

[0020] Unless otherwise stated, any patent, publication or other public material identified herein is incorporated by reference in its entirety into this specification, but only to the extent that the incorporated material does not conflict with existing definitions, statements or other public materials clearly set forth in this specification. Thus, and to the extent necessary, the explicit disclosures set forth in this specification replace any conflicting material incorporated by reference herein. Any material or portion thereof incorporated by reference into this specification but conflicting with existing definitions, statements or other public materials set forth herein is incorporated only to the extent that there is no conflict between the incorporated material and the existing public materials. The applicant reserves the right to amend this specification to expressly record any subject matter or portion thereof incorporated by reference herein.

[0021] References throughout this specification to "various non-limiting embodiments," "certain embodiments," etc., are intended to indicate that a particular feature or characteristic may be included in one embodiment. Thus, the use of the phrases "in various non-limiting embodiments," "certain embodiments," etc., in this specification does not necessarily refer to a common embodiment, but may refer to different embodiments. Furthermore, particular features or characteristics may be combined in any suitable manner in one or more embodiments. Thus, particular features or characteristics illustrated or described in conjunction with various or certain embodiments may be combined in whole or in part with features or characteristics of one or more other embodiments without limitation. Such modifications and variations are intended to be included within the scope of this specification.

[0022] Unless otherwise indicated, the grammatical articles "a", "an", and "the" as used herein are intended to include "at least one" or "one or more", even though in some cases "at least one" or "one or more" is explicitly used. Thus, these articles are used in this specification to refer to one or more than one (i.e., "at least one") of the grammatical objects of the article. For example, and not limitation, "a component" means one or more components, and thus, feasibly, more than one component is contemplated and may be employed or used in the implementation of the described embodiments. Furthermore, unless the context requires otherwise, the use of a singular noun includes the plural, and the use of a plural noun includes the singular.

[0023] In one aspect, the present invention is directed to a packaging material comprising a first layer formed of a thermoplastic polyurethane (TPU) and a second layer formed of a heat activated olefin-based polymer coupling agent containing an ethylene vinyl acetate (EVA) copolymer and a second polar comonomer, wherein the packaging material has a total thickness of 2 mils (50 µm) to 24 mils (600 µm), the first layer has a thickness of 0.8 mils (20 µm) to 16 mils (400 µm), and the second layer has a thickness of 0.8 mils (20 µm) to 8 mils (200 µm).

[0024] Thermoplastic polyurethane (TPU) is well known in the art for its wear stable properties. TPU is a strong material, and TPU products exhibit high tear strength and tolerance, durability (even for soft grades), good chemical resistance, desirable clarity, significant abrasion resistance, and excellent low temperature performance. Bags consisting of TPU alone do not provide adequate barrier properties for small format films. Solutions for packaging including nested blister packs and composite blister packs are provided.

[0025] Due to its customizability, thermoplastic polyurethane (TPU) is an ideal material for building various medical devices, such as tubes and fluid storage bags. The safety of TPU products for use on or in the human body is very important, because medical products must often transport drugs, blood or other fluids, and therefore the materials used in their development must not leak any harmful substances that may penetrate (leach) into these fluids and damage the integrity of the fluids. The combination of materials does not have to be carried out in one step. Lamination of materials is a preferred way to obtain thermoformable products for subsequent thermoforming or FFS packaging.

[0026] New packaging design can combine the anti-mechanical puncture and wear stability of TPU-elastomer with the thermoforming properties of rigid polymers, such as polyethylene terephthalate (PETG), cycloolefin copolymer (COC), or polyolefins such as cross-linked polyethylene (PE) foam. This can be achieved by forming a laminate of different materials and customizing these laminates using a thermoforming process. If bonded in a reliable and consistent manner, these layers can form a specific shape together to meet the needs of orthopedic medical implants being firmly held in place. Such user-friendly design helps to avoid more complicated packaging structures, which include a separate sleeve, or a bag with a wear-stabilizing layer and a rigid thermoformed outer packaging box.

[0027] Thermoplastic polyurethane (TPU) formulations can be tailored to the requirements of use in the medical industry. Since no plasticizers are involved in TPU production, harmful by-products are eliminated. TPU is well known for its reliability in the medical field, and its formulations have long been certified as biocompatible.

[0028] In order to ensure the longevity of medical products, convenient sealing is necessary. Such sealing techniques such as ultrasonic and solvent welding can provide more effective and consistent weld quality than other conventional methods. The use of these sealing techniques using thermoplastic polyurethane (TPU) is well known to those skilled in the art.

[0029] like Figure 1 As shown in FIG. 1 , the packaging material according to the present invention comprises a first layer 1 made of thermoplastic polyurethane (TPU) and a second layer 2 comprising modified ethylene vinyl acetate (EVA).

[0030] In certain embodiments, the second layer 2 comprises a TPU-modified EVA copolymer, which is made by blending TPU and EVA to improve adhesion to different polymers. This blending process provides excellent adhesion properties to both TPU and rigid thermoforming polymers. In these embodiments, the packaging material according to the present invention contains at least one TPU / EVA blend layer.

[0031] The second layer 2 also contains polar comonomers, such as disclosed in U.S. Patent No. 5,593,775. Ethylene is preferably used as a comonomer. In the packaging material according to the present invention, at least two different polar oxygen-containing olefin copolymers A and B are blended and melted together under sufficient shearing. In various embodiments, relative to the gross weight of the polymer resin used, the total proportion of polar oxygen-containing comonomer units is 18 wt % to 40 wt %. Olefin comonomer A should be present in a larger amount, and its total proportion is at least 60% of the total weight of the comonomer units. In certain embodiments, the comonomers used for polar olefin copolymers A and B are methacrylic acid and / or its salt and / or its ester, and / or acrylic acid and / or its salt and / or its ester, and / or vinyl acetate in unsaponified and / or saponified form.

[0032] In some embodiments, TPU ether-based films are preferred over TPU ester-based films due to the improved hydrolysis resistance of the former.

[0033] In addition, the coextrusion manufacturing of the film comprising a common TPU layer facing a surface and at least one TPU / EVA layer facing another surface for the purpose of bonding improves the performance of the packaging material of the present invention. The coextrusion process provides a selection for further bridging by combining with an extra layer. Such coextrusion film is particularly suitable for flame bonding to cross-linked polyethylene (PE) foam. As known in the art, the PE foam improved through the surface is suitable for packaging medical equipment, and is particularly suitable for medical equipment packaging intended for surgical implants.

[0034] Adhesive modified EVA provides improved adhesion properties between TPU and structured olefin surfaces. Adhesion properties can be introduced by inserting an adhesive layer between the TPU and the olefin, or by blending the TPU with the olefin. In certain embodiments, this can be accomplished by providing a bridging layer that is compatible by blending the TPU with the EVA and having a TPU surface layer.

[0035] Suitable olefinic materials for use in the present invention include, but are not limited to, polyethylene (eg, high density HDPE, low density LDPE, and linear low density LLDPE), polypropylene, polymethylpentene, polyisobutylene, polybutene, and ethylene propylene diene monomer (EPDM) rubber.

[0036] For a blending ratio of 0.3% to 3.0% by mass of TPU / EVA, the adhesion property of the second layer 2 exhibits the most suitable performance. In certain embodiments, the blending ratio between TPU and modified EVA is 0.7% to 1.5% by mass.

[0037] TPU and EVA can be used in thermoplastic technology due to the combined processing window, which makes them suitable partners for enhancing adhesion properties. This combined thermoplastic processing window can be used in the film extrusion process to allow co-extrusion of the various layers.

[0038] In some embodiments, EVA-maleic anhydride (MSA) terpolymers can be selected. These polymers can be random copolymers, or in some embodiments, MSA can be grafted onto the EVA backbone. Certain embodiments of the packaging material of the present invention contain at least the following two layers: a layer 1 formed by TPU providing wear stability, and a layer 2 formed by a TPU / EVA blend providing adhesion.

[0039] In certain embodiments, the coupling material resin used for the second layer 2 contains ethylene, vinyl acetate and maleic anhydride as comonomers, wherein the total amount of maleic anhydride does not exceed 5000 ppm.

[0040] The first layer 1 of the packaging material according to the present invention comprises at least one TPU elastomer, preferably a linear TPU elastomer, whose long-chain diol component is a polyester or a polyether, and has a Shore A hardness of preferably 75-95 measured according to ASTM D 2240. TPU ether-based films are preferred over TPU ester-based films because the former have improved hydrolysis resistance.

[0041] Suitable thermoplastic polyurethanes are available from various commercial suppliers under the trade names: DESMOPAN, ELASTOLLAN, ESTANE, MORTHANE and TEXIN.

[0042] The packaging material according to various embodiments of the present invention may contain additional processing additives in the first layer 1, such as the following:

[0043] a) Anti-blocking agent, inorganic or organic spacer;

[0044] b) Slip aids or release aids, usually surface-active;

[0045] c) pigments or fillers; and

[0046] d) Stabilizer.

[0047] In selected embodiments, the total amount of additive a, additive b, additive c, and additive d is from 0% to 30%, and in certain embodiments, the total amount is >0% to 30%.

[0048] In various embodiments, the film has a total thickness of 2 mils (50 µm) to 24 mils (600 µm). In these embodiments, the first (TPU) layer 1 has a layer thickness of 0.8 mils (20 µm) to 16 mils (400 µm), and the second (blend) layer 2 has a thickness gauge of 0.8 mils (20 µm) to 8 mils (200 µm).

[0049] To produce multilayer structures such as packaging materials, known thermoforming processes for processing plastic materials can be used. In particular, coextrusion technology is preferred for a higher level of bond strength between the layers at temperatures of 160° C. to 200° C. Blown film coextrusion is a particularly preferred method for producing the packaging material according to the invention.

[0050] During the manufacture of the packaging material of the present invention, the film may be surface treated so that at least one of the outer layers of the packaging material may be chemically or physically treated.

[0051] The packaging material according to the present invention can be used to make containers (e.g. bags, trays, etc.) for sharp abrasive articles by lamination to a rigid plastic material followed by thermoforming. The packaging material provides the advantage that it can be obtained by various heat and solvent based sealing methods. The packaging material according to the present invention is particularly advantageous in the packaging of sharp abrasive articles. Example

[0052] The following non-limiting and non-exhaustive examples are intended to further describe various non-limiting and non-exhaustive embodiments without limiting the scope of the embodiments described in this specification. Unless otherwise indicated, all quantities given in "parts" and "percents" are understood to be by weight.

[0053] The following examples and comparative examples were produced by blown film extrusion. Kunststoffe (84 (1994) 1131-1138), Pearson Mechanics of Polymer Processing (Elsevier Publishers, New York, 1985), or Davis-Standard Company, Paper, Film & Foil Converter Extrusion processes suitable for processing thermoplastic materials are described in Rauwendaal 64 (1990), pp. 84-90. Polymer Extrusion (Hanser Publishers, New York 1986), and Michaeli in Extrusions-Werkzeuge(Hanser Verlag, Munich 1991) describes a blown film tool for forming the melt into a film shape.

[0054] Example 1

[0055] A coextruded film was produced using a two-layer blown film die, comprising a first layer formed of a TPU-ether having a Shore A hardness of 89 measured according to ASTM D2240, equivalent to a Shore D hardness of 36. The TPU-ether had a melt flow index (MFI) (@190°C / 21.6kg) of 25 g / 10 min according to ISO 1133-1, a thermal conductivity of 1.12 g / cm2 according to ISO 1183-1, and a thermal conductivity of 1.12 g / cm3 according to ISO 1183-1. 3 The 100µm layer contained processing additives: 2.5% diatomaceous earth and 0.3% amide wax. All ingredients of this first layer were processed in a single extruder.

[0056] The second layer is ethylene-vinyl acetate copolymer grafted with maleic anhydride having a melt flow index (MFI) of 3.5 g / 10 min (@ 230°C / 2.16 kg) according to ISO 1133-1 and a MFI of 0.94 g / cm2 according to ISO 1183-1. 3 The specific gravity is 28 mass %. The vinyl acetate (VA) content of the resin is 28 mass %, and the maleic anhydride is less than 4000 ppm. The Shore A hardness according to ASTM D2240 is 80 / Shore D hardness is 27. The TMA starting temperature is 75°C. The second layer has a thickness of 50 µm.

[0057] The extrusion tool was set to a temperature of 160° C. to 200° C. The two melt streams were combined in a double-layer blown film die at a processing temperature of 195° C. and ejected through a circular die with a diameter of 130 mm. The circular melt was cooled by blowing cold air thereon. The film was then shrunk, laid flat, separated, and rolled up.

[0058] Example 2

[0059] The coextruded film was produced using a two-layer blown film die starting with a first layer formed from a TPU-ether having a Shore A hardness of 89 measured according to ASTM D2240, equivalent to a Shore D hardness of 36. The TPU-ether had a melt flow index (MFI) (@190°C / 21.6kg) of 25 g / 10 min according to ISO 1133-1, a hardness of 1.12 g / cm2 according to ISO 1183-1, and a hardness of 1.2 g / cm3 according to ISO 1183-1. 3The 90µm layer contained processing additives: 2.5% diatomaceous earth and 0.3% amide wax. All ingredients of this first layer were processed in a single extruder.

[0060] The second layer is a blend of 50 wt% TPU-ether having a melt flow index (MFI) (@190°C / 21.6 kg) of 25 g / 10 min according to ISO 1133-1, a MFI of 1.12 g / cm2 according to ISO 1183-1, and a graft copolymer of 50 wt% ethylene-vinyl acetate / maleic anhydride. 3 The graft copolymer has a specific gravity of 89 Shore A hardness / 36 Shore D hardness according to ASTM D2240, and a TMA onset temperature of 165°C, and the graft copolymer has a melt flow index (MFI) of 3.5 g / 10 min according to ISO 1133-1 (@230°C / 2.16 kg) and a TMA onset temperature of 165°C. 3 The specific gravity is 28 mass %. The vinyl acetate content of the resin is 28 mass %, and the maleic anhydride is less than 4000 ppm. The Shore A hardness according to ASTM D2240 is 80 / Shore D hardness is 27. The TMA starting temperature is 75°C. The second layer has a thickness of 60 µm.

[0061] The extrusion tool was set to a temperature of 160° C. to 200° C. The two melt streams were combined in a double-layer blown film die at a processing temperature of 195° C. and ejected through a circular die with a diameter of 130 mm. The circular melt was cooled by blowing cold air thereon. The film was then shrunk, laid flat, separated, and rolled up.

[0062] Comparative Example 1

[0063] A film was made from the TPU-ether using a single-layer blown film die, which had a Shore A hardness of 89 measured according to ASTM D2240, equivalent to a Shore D hardness of 36. The TPU-ether had a melt flow index (MFI) (@190°C / 21.6kg) of 25 g / 10 min according to ISO 1133-1, a hardness of 1.12 g / cm according to ISO 1183-1, and a hardness of 1.2 g / cm 3 The 150 µm layer contains processing additives: 2.5% diatomaceous earth and 0.3% amide wax. All components of this layer are processed in a single extruder.

[0064] The extruder was operated at a temperature of 160°C to 200°C. The melt stream was inserted into a blown film die at a processing temperature of 195°C and ejected through a lip set of 130 mm in diameter. The round melt was cooled by blowing cold air on it. The film was then shrunk, laid flat, separated, and rolled up.

[0065] Comparative Example 2

[0066] A coextruded film comprising a layer formed of a TPU-ester having a Shore A hardness of 90 measured according to ASTM D2240, equivalent to a Shore D hardness of 40, was produced using a two-layer blown film die. The TPU-ester had a melt flow index (MFI) (@190°C / 21.6kg) of 60 g / 10 min according to ISO 1133-1, a hardness of 1.22 g / cm2 according to ISO 1183-1, and a hardness of 1.5 g / cm3 according to ISO 1183-1. 3 and a TMA onset temperature of 170°C. The 30µm layer contains processing additives: 5% diatomaceous earth and 1% amide wax. All components of this layer are processed in a single extruder.

[0067] The second layer is essentially made of linear hydroxyl polyester polyurethane. This flexible hot melt polyurethane with a high crystallinity generally has excellent adhesion to a wide range of materials. Extruded flat products made from this raw material are known to have a high quality. The TPU-ester has a viscosity of 1200 mPas according to ISO 3219 and a viscosity of 1.16 g / cm2 according to ISO 1183-1. 3 A specific gravity of 94, a Shore A hardness of 45 according to ASTM D2240, and a TMA onset temperature of 55° C. The second layer has a thickness of 20 µm.

[0068] The extrusion tool is set to a temperature of 130° C. to 180° C. The melt stream is introduced into a multilayer blown film die at a processing temperature of 180° C. and ejected through a round lip assembly having a diameter of 300 mm. The round melt is cooled by blowing cold air thereon. The film is then shrunk, laid flat, separated, and rolled up.

[0069] Comparative Example 3

[0070] A single-layer blown film die was used to make a film made of a TPU-ester having a Shore A hardness of 90 measured according to ASTM D2240, equivalent to a Shore D hardness of 39. The TPU-ester had a melt flow index (MFI) of 16 g / 10 min (@ 190°C / 8.7 kg) according to ISO 1133-1, a hardness of 1.19 g / cm2 according to ISO 1183-1, and a hardness of 1.2 g / cm3 according to ISO 1183-1. 3The 130 µm layer contains processing additives: 1.5% diatomaceous earth and 0.4% amide wax. All components of this layer are processed in a single extruder.

[0071] The extruder is operated at a temperature of 160°C to 190°C. The melt stream is introduced into a blown film die at a processing temperature of 185°C and ejected through a lip assembly having a diameter of 130 mm. The round melt is cooled by blowing cold air thereon. The film is then shrunk, laid flat, separated, and rolled up.

[0072] Evaluation of the performance of the samples of the invention and the comparative samples focused on adhesion directly to polyethylene and to polyethylene during thermoforming. The adhesion strength to the olefin layer was tested in the films prepared as samples and comparative examples.

[0073] The films prepared as samples and comparative examples were laminated using a HOTRONIX laminator. The films were laminated against a polyethylene (PE) film having a thickness of 0.0045 inches / 115 µm. The PE had a melt flow index (MFI) (@190°C / 2.16 kg) of 0.4 g / 10 min according to ISO 1133-1, a MFI of 0.92 g / cm2 according to ISO 1183-1, and a MFI of 0.5 g / cm3 according to ISO 1183-1. 3 and a Shore D hardness of 45 / Shore A hardness of 94. The PE film had a TMA onset temperature of 103° C. Lamination was performed at 150° C. for 10 seconds.

[0074] A visual depiction of the artificial separation was determined, as well as tensile test results from the test rig.

[0075] For tensile testing, 1 inch / 25.4 mm wide specimen strips were cut from the laminate using a parallel blade specimen cutter. The separation force was determined using a conventional specimen grip and the load cell of the tensile testing apparatus.

[0076] To obtain the thermoforming results, blanks of approximately 125 mm diameter were cut from the laminate and heated using a MINISTAR S thermoforming device. They were heated in an infrared (IR) field for approximately 20 seconds and then drawn on a cylindrical round-bottom shape (75 mm in height and 75 mm in diameter).

[0077] Table I summarizes the results of the examples detailed above.

[0078] Table I

[0079] nature Example 1 Example 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 EVA layer facing PE TPU / EVA blend layer facing PE Hot melt adhesive polyurethane layer facing PE Delamination - Description Film Stretch Failure* - Very Good Bond Film Tensile Failure* - Good Bonding Bond failure - very weak bond Bond failure - very weak bond Bond failure - very weak bond Tensile test-peel strength g / in. (gf) 825 292 10 8 7 Thermoforming - Visual Description Consistent, visually uniform, transparent Consistent, fuzzy, turbid Consistent, visually uniform, blurry Consistent, visually uniform, blurry Consistent, visually uniform, transparent Thermoformed parts No layer separation No layer separation Layer separation Layer separation Layer separation

[0080] It is apparent by reference to Table I that the films made according to the present invention outperform the comparative films.

[0081] This specification has been written with reference to various non-limiting and non-exhaustive embodiments. However, it will be appreciated by those of ordinary skill in the art that various substitutions, modifications or combinations of any disclosed embodiment (or portion thereof) may be made within the scope of this specification. Therefore, it is conceivable and understood that this specification supports additional embodiments that are not explicitly set forth herein. Such embodiments may be obtained, for example, by combining, modifying or reorganizing the steps, components, elements, features, aspects, characteristics, limitations, etc. disclosed in the various non-limiting embodiments described in this specification. Thus, the applicant reserves the right to amend the claims during the examination to add the various described features in this specification, and such amendments comply with the requirements of 35 U.S.C. §112(a) and 35 USC §132(a).

[0082] Various aspects of the subject matter described herein are set forth in the numbered clauses below:

[0083] Clause 1. A packaging material comprising a first layer formed of a thermoplastic polyurethane (TPU) and a second layer formed of a heat activated olefin-based polymer coupling agent containing an ethylene vinyl acetate (EVA) copolymer and a second polar comonomer, wherein the packaging material has a total thickness of 2 mils (50 µm) to 24 mils (600 µm), the first layer has a thickness of 0.8 mils (20 µm) to 16 mils (400 µm), and the second layer has a thickness of 0.8 mils (20 µm) to 8 mils (200 µm).

[0084] Clause 2. The packaging material of Clause 1, wherein the first layer comprises TPU-ether.

[0085] Clause 3. The packaging material according to any one of Clauses 1 and 2, wherein the first layer has a Shore A hardness of 75-95 measured according to ASTM D 2240.

[0086] Clause 4. The packaging material of any one of Clauses 1 to 3, wherein the second layer is a blend comprising thermoplastic polyurethane (TPU) and ethylene vinyl acetate (EVA) copolymer.

[0087] Clause 5. The packaging material according to any one of Clauses 1 to 4, wherein the ethylene vinyl acetate (EVA) copolymer contains at least 15% vinyl acetate.

[0088] Clause 6. The packaging material according to any one of Clauses 1 to 5, wherein the olefin-based polymer coupling agent contains less than 5000 ppm of maleic anhydride.

[0089] Clause 7. The packaging material according to any one of Clauses 1 to 6, wherein the second layer comprises a blend of thermoplastic polyurethane (TPU) and modified ethylene vinyl acetate (EVA) in a ratio of 0.3% to 3.0% by mass.

[0090] Clause 8. The packaging material according to any one of Clauses 1 to 7, wherein the second layer comprises a blend of thermoplastic polyurethane (TPU) and modified ethylene vinyl acetate (EVA) in a ratio of 0.7% to 1.5% by mass.

[0091] Clause 9. The packaging material according to any one of Clauses 1 to 8, wherein the second polar comonomer contains one of a plurality of comonomers selected from the group consisting of vinyl acetate, acrylic acid, acrylic acid esters, acrylic acid salts, methacrylic acid, methacrylic acid esters and methacrylic acid salts.

[0092] Clause 10. The packaging material according to any one of clauses 1 to 9, wherein 0% to 30% of an additive is added to the first layer, the additive being selected from anti-blocking agents, inorganic or organic release agents, slip aids or separation aids, pigments, fillers and stabilizers.

[0093] Clause 11. The packaging material according to any one of clauses 1 to 10, wherein the packaging material is produced in a coextrusion process at a temperature of 160°C to 200°C.

[0094] Clause 12. The packaging material according to any one of clauses 1 to 10, wherein the packaging material is produced in a blown film coextrusion process at a temperature of 160°C to 200°C.

[0095] Clause 13. The packaging material according to any one of Clauses 1 to 12, wherein at least one layer is subjected to a physical or chemical surface treatment.

[0096] Clause 14. One of a container and a tray comprising the packaging material according to any one of Clauses 1 to 13.

[0097] Clause 15. One of a container and a tray according to Clause 14, wherein the packaging material is laminated to the polyethylene or cross-linked polyethylene by one selected from thermal lamination and flame bonding.

[0098] Clause 16. One of a container and a tray according to any one of Clauses 14 and 15, wherein the one is thermoformed.

[0099] Clause 17. A method of transporting a sharp abrasive article, the method comprising placing the article in a thermoformed container according to Clause 16.

[0100] Clause 18. A method of transporting a sharp abrasive article, the method comprising contacting the article with the thermoformed tray according to Clause 16.

[0101] Clause 19. The method of any one of Clauses 16 and 17, wherein the sharp abrasive article is an orthopedic device.

[0102] Clause 20. The method of Clause 19, wherein the orthopedic device is a bone implant.

[0103] Clause 21. A sharp abrasive article in a thermoformed container comprising the packaging material of any one of Clauses 1 to 13.

[0104] Clause 22. A sharp abrasive article contacting a thermoformed tray comprising the packaging material of any one of Clauses 1 to 13.

Claims

1. A packaging material, comprising: a first layer formed of thermoplastic polyurethane; and a second layer formed from a heat activated olefin-based polymer coupling agent comprising ethylene-vinyl acetate copolymer grafted with maleic anhydride, wherein the total amount of maleic anhydride does not exceed 5000 ppm, wherein the second polar comonomer is selected from acrylic acid, acrylates, acrylate salts, methacrylic acid, methacrylates and methacrylate salts, wherein the second layer is a blend comprising thermoplastic polyurethane and ethylene-vinyl acetate copolymer, Wherein the packaging material has a total thickness of 50 μm to 600 μm, the first layer has a thickness of 20 μm to 400 μm, and the second layer has a thickness of 20 μm to 200 μm.

2. The packaging material of claim 1, wherein the first layer comprises a thermoplastic polyurethane-ether. 3 . The packaging material of claim 1 , wherein the first layer has a Shore A hardness of 75-95 measured according to ASTM D 2240. 4 .

4. The packaging material of claim 1, wherein the ethylene-vinyl acetate copolymer contains at least 15% vinyl acetate. 5 . The packaging material according to claim 1 , wherein the second layer comprises a blend of thermoplastic polyurethane and modified ethylene vinyl acetate in a ratio of 0.3% to 3.0% by mass. 6 . The packaging material according to claim 1 , wherein the second layer comprises a blend of thermoplastic polyurethane and modified ethylene vinyl acetate in a ratio of 0.7% to 1.5% by mass.

7. The packaging material according to claim 1, wherein 0% to 30% of an additive is added to the first layer, the additive being selected from anti-blocking agents, inorganic or organic release agents, slip aids or separation aids, pigments, fillers and stabilizers.

8. The packaging material according to claim 1, wherein the packaging material is produced in a co-extrusion process at a temperature of 160°C to 200°C.

9. The packaging material according to claim 8, wherein the packaging material is produced in a blown film coextrusion process at a temperature of 160°C to 200°C.

10. The packaging material of claim 1, wherein at least one layer is subjected to a physical or chemical surface treatment.

11. One of a container and a tray thermoformed comprising the packaging material according to claim 1.

12. One of a container and a tray according to claim 11, wherein the packaging material is laminated to polyethylene or cross-linked polyethylene by one selected from thermal lamination and flame bonding.

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