Polypropylene blister package

Abstract

A system for forming a blister package includes a thermoformable film and a capping film. The thermoformable film has an outer thermoformable film layer and an inner thermoformable film layer. The thermoformable film outer layer includes at least 50 wt% polypropylene. The thermoformable film inner layer includes at least 50% by weight of polypropylene and (a) a tackifier and / or (b) a cycloolefin copolymer. The sealing cover film comprises a sealing cover film outer layer, a sealing layer and a sealing cover film inner layer located between the sealing cover film outer layer and the sealing layer. The capping film outer layer includes at least 50% polypropylene. The capping film inner layer includes at least 50% polypropylene and a tackifier. The sealing layer includes a polyolefin plastomer.

Description

TECHNICAL FIELD

[0001] The present disclosure generally relates to films suitable for thermoforming into packaging components, such as recyclable films and the like. BACKGROUND OF THE INVENTION

[0002] Polypropylene is a highly adaptable semi-crystalline material that is easy to recycle. However, polypropylene is generally not used for thermoforming in molding / filling / sealing packaging lines due to its narrow thermoforming temperature window. Materials with a higher degree of amorphousness are generally used in such thermoforming due to their wider thermoforming temperature windows. SUMMARY OF THE INVENTION

[0003] The present disclosure particularly describes systems and methods for forming blister packages. A film containing at least 50 wt% polypropylene can be thermoformed and sealed to a capping film to produce a blister pack. The capping film can contain more than 50 wt% polypropylene. The blister pack can be recyclable.

[0004] The thermoformable film can comprise layers that include: at least 50% polypropylene, and a tackifier, a cycloolefin copolymer, or a tackifier and a cycloolefin copolymer. The tackifier and / or cycloolefin copolymer broaden the thermoforming temperature window and can improve sag resistance relative to a layer consisting essentially of polypropylene. Such films are suitable for practical use in thermoforming, particularly on molding / filling / sealing packaging lines with short dwell times.

[0005] In one or more aspects, the present disclosure describes a system for forming a blister package. The system includes a thermoformable film and a capping film. The thermoformable film comprises a thermoformable film outer layer and a thermoformable film inner layer. The thermoformable film outer layer contains at least 50 wt% polypropylene. The thermoformable film inner layer contains at least 50 wt% polypropylene and (a) a tackifier and / or (b) a cycloolefin copolymer. The capping film comprises a capping film outer layer, a capping film inner layer, and a sealing layer. The capping film outer layer contains at least 50 wt% polypropylene. The capping film inner layer contains at least 50 wt% polypropylene and a tackifier. The sealing layer contains a polyolefin plastomer.

[0006] A method for forming a blister pack includes thermoforming a tray from the thermoformable film and heat-sealing the capping film to the tray to form the blister pack.

[0007] The blister pack can include a tray formed from the thermoformable film and a cap formed from the capping film and sealed to the tray. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The following detailed description of specific embodiments of the present disclosure can be best understood when read in conjunction with the following drawings, in which like structures are indicated by like reference numerals, and in which:

[0009] Figures 1-7 is a schematic cross-sectional view of an embodiment of a film according to the present disclosure.

[0010] Figure 8 is a schematic perspective view of a thermoformed base assembly including 10 cavities according to an embodiment of the present disclosure.

[0011] Figure 9 is a schematic top view of an embodiment of a thermoformed base assembly showing 12 cavities and a flange.

[0012] Figure 10 is a schematic cross-sectional view of an embodiment of a package including a thermoformed base assembly, a product, and a lid assembly.

[0013] Figure 11 is a schematic view of a cross-section of an embodiment of a lid assembly for packaging a product.

[0014] Figure 12A -D and 13A-D are images of the film as described in the examples.

[0015] The drawings illustrate some but not all of the embodiments. The elements depicted in the drawings are illustrative and not necessarily drawn to scale. Throughout the drawings, like (or similar) reference numerals represent like (or similar) features. However, it should be understood that using a number to refer to a component in a given drawing is not intended to limit the component denoted by the same number in another drawing. Additionally, using different numbers to refer to components is not intended to indicate that components with different numbers cannot be the same or similar to other numbered components. Detailed Description

[0016] The present disclosure particularly relates to films comprising polypropylene layers suitable for thermoforming. The film comprises one or more layers that comprise at least 50% polypropylene and a tackifier and / or a cycloolefin copolymer. Such films can have thermoforming properties suitable for form / fill / seal packaging equipment, and such properties include a broadened thermoforming temperature window and anti-sag properties.

[0017] Polypropylene is a semi-crystalline material with a narrow thermoforming temperature window. As described herein, adding a tackifier can allow more polypropylene chains to move at a temperature close to the Tg of the tackifier, thereby making the polypropylene film or layer more stretchable. The result of adding the tackifier can extend the lower end of the thermoforming temperature window. In some embodiments, the films or layers described herein can include a crosslinking agent. The crosslinking agent can be used to enhance the melt strength of the material, which can increase the upper end of the thermoforming temperature window. The crosslinking agent can also be used to increase the number of times the film or article can be reused, thereby further enhancing recyclability.

[0018] Adding a cycloolefin copolymer to the polypropylene films or layers described herein can broaden the thermoforming temperature window. Adding a cycloolefin copolymer can improve sag resistance. In some embodiments, relative to a film or layer consisting essentially of polypropylene, the addition of a cycloolefin copolymer broadens the thermoforming temperature window and improves sag resistance. The addition of a cycloolefin copolymer can improve the barrier properties of the polypropylene film or layer. However, the total amount of cycloolefin copolymer in the layer, film, or package is preferably kept low enough to allow the film or package containing the cycloolefin copolymer-containing layer to be recyclable.

[0019] Polypropylene

[0020] The films, layers, and packages described herein contain polypropylene (PP). As used herein, "polypropylene" is a polymer formed from propylene monomers or propylene monomers and one or more other monomers. PP can be a homopolymer or a copolymer. PP can be unmodified or modified. For example, PP can be modified by, for example, post-polymerization derivatization to add functional groups or moieties along the polymer chain.

[0021] In some embodiments, PP is a homopolymer. In some embodiments, PP is a copolymer. In some embodiments, PP is a random copolymer. In some embodiments, PP is a blend of a homopolymer and a copolymer. In some embodiments, PP is a blend of a homopolymer and a random copolymer.

[0022] PP can contain at least 50 wt% propylene, such as at least 60 wt% of PP, at least 70 wt% of PP, at least 90 wt% of PP, or about 100 wt% of PP. In some embodiments, PP contains from about 80 wt% of PP to about 99.5 wt% of PP.

[0023] In some embodiments, PP cumulatively contains less than 50 wt% comonomer. In some embodiments, PP contains 40 wt% or less comonomer, 30 wt% or less comonomer, 20 wt% or less comonomer, or 10 wt% or less comonomer.

[0024] In some embodiments, PP contains a comonomer selected from ethylene and α-olefins having 4 to 12 carbon atoms. In some embodiments, PP contains ethylene. In embodiments, PP contains a comonomer selected from ethylene and α-olefins having 4 to 12 carbon atoms, and the weight percentage of the comonomer is 0.1% to about 20%, such as about 0.5% to about 15%, about 0.5% to about 10%, about 0.5% to about 8%, 1% to about 15%, about 1% to about 10%, about 1% to about 8%, 2% to about 15%, about 2% to about 10%, or about 2% to about 8%.

[0025] Films, layers, and packages containing PP can have any suitable amount of PP. In some embodiments, the film, layer, or package contains 50 wt% or more (at least 50 wt%) of PP, such as at least 60 wt% of PP, at least 70 wt% of PP, at least 80 wt% of PP, or at least 90 wt% of PP. In some embodiments, the film, layer, and package contain less than 95 wt% of PP. In some embodiments, the film, layer, and package contain from about 50 wt% of PP to about 95 wt% of PP, such as from about 50 wt% of PP to about 90 wt% of PP, from about 50 wt% of PP to about 80 wt% of PP, from about 50 wt% of PP to about 70 wt% of PP, from about 50 wt% of PP to about 60 wt% of PP, from about 60 wt% of PP to about 95 wt% of PP, from about 60 wt% of PP to about 90 wt% of PP, from about 60 wt% of PP to about 80 wt% of PP, from about 60 wt% of PP to about 70 wt% of PP, from about 70 wt% of PP to about 95 wt% of PP, from about 70 wt% of PP to about 90 wt% of PP, from about 70 wt% of PP to about 80 wt% of PP, from about 80 wt% of PP to about 95 wt% of PP, or from about 80 wt% of PP to about 90 wt% of PP.

[0026] In some embodiments, the PP comprises isotactic PP. The isotactic PP can be mostly, highly, or predominantly isotactic PP. The layers, films, or packages described herein can contain PP having any suitable molecular weight for forming the film or layer. The mass flow rate can be related to the molecular weight. In an embodiment, the mass flow rate of the PP is from about 0.5 grams per 10 minutes (g per 10 minutes) to about 10 grams per 10 minutes, such as from about 0.6 grams per 10 minutes to about 8 grams per 10 minutes, from about 0.8 grams per 10 minutes to about 6 grams per 10 minutes, or from about 2 grams per 10 minutes to about 4 grams per 10 minutes. The mass flow rate can be measured according to ASTM D1238-20 (September 3, 2020), the standard test method for measuring the melt flow rate of thermoplastics by an extrusion plastometer.

[0027] Examples of PP homopolymers that can be used in the layers, films, or packages described herein are 6021N polypropylene homopolymer (Braskem INSPIRE 6021N). Examples of polypropylene random copolymers that can be used in the blends or layers described herein are 6232 polypropylene copolymer (e.g., from Total or TotalEnergies).

[0028] In some embodiments, at least some of the PP in the layers, films or packages described herein is impact polypropylene. As used herein, "impact polypropylene" is a copolymer produced by the polymerization of propylene and ethylene, which has a heterogeneous, mainly amorphous structure within a polypropylene homopolymer matrix. Impact PP can be produced in any suitable manner. In some embodiments, impact PP is produced in a series reactor, where the rubber phase is produced in one reactor and the homopolymer is produced in another reactor. The properties of the resin depend not only on the rubber content but also on the size of the rubber domains.

[0029] Impact PP can have any suitable mass flow rate. In some embodiments, the mass flow rate of impact PP is from about 0.4 grams per 10 minutes to about 0.8 grams per 10 minutes.

[0030] Examples of impact polypropylene are propylene homopolymers containing a blended propylene random copolymer phase with an ethylene content of 45% to 65%. Examples of suitable impact PP that can be included in the blend or layer include Total (TotalEnergies) 4170, LyondellBasell Pro-fax 7823, and LyondellBasell Adflex Q 100F. Total 4170 has the following properties: melt flow rate (MFR) = 0.8 grams per 10 minutes; density = 0.905 g / cm 3 ; Tm = 160 - 165 °C. Profax 7823 has the following properties: MFR = 0.45 grams per 10 minutes; density = 0.90 g / cm 3 . Adflex Q 100F has the following properties: MFR = 0.6 grams per 10 minutes; density = 0.88 g / cm3; Tm = 142 °C.

[0031] In some embodiments, the blend or layer contains at least 5 wt% of impact PP, such as at least 10 wt% of impact PP, at least 15 wt% of impact PP, at least about 20 wt% of impact PP, at least about 25 wt% of impact PP, at least about 30 wt% of impact PP, or at least about 35 wt% of impact PP. In some embodiments, the blend or layer contains less than 50 wt% of impact PP, such as less than 40 wt% of impact PP. In some embodiments, the blend or layer contains from about 10 wt% to about 30 wt% of impact PP, from about 5 wt% to about 35 wt% of impact PP, or from 10 wt% to about 25 wt% of impact PP or from about 10 wt% to about 20 wt% of impact PP.

[0032] Cycloolefin copolymer

[0033] The films, layers, and packages described herein may include cycloolefin copolymer (COC). COC is a copolymer prepared by polymerizing at least one α-olefin comonomer with at least one cycloaliphatic comonomer (and / or at least one cycloaromatic comonomer), where the at least one cycloaliphatic comonomer has its reactive olefin moiety (i.e., part of the cyclic structure) or its reactive olefin moiety (e.g., an α-olefin substituent on the cyclic structure). In some embodiments, the COC is formed from α-olefin comonomers that include C2-C 20 α-olefins, such as C4-C 12 aliphatic α-olefin comonomers. In some embodiments, the COC is formed from α-olefin comonomers that include C4, C6, C8, C 10 and / or C 12 one or more of the α-olefin comonomers. In some embodiments, the COC is formed from α-olefin comonomers that include norbornene. In some embodiments, the COC is formed by the polymerization of propylene and an α-olefin comonomer. In some embodiments, the COC is a propylene / norbornene copolymer. In some embodiments, the COC is formed by the polymerization of ethylene and an α-olefin comonomer. In some embodiments, the COC is an ethylene / norbornene copolymer. In some embodiments, the ethylene-norbornene COC contains 20 mole % to 70 mole % ethylene and 30 mole % to 60 mole % norbornene.

[0034] Examples of commercially available COCs are the COCs from Topas Advanced Polymers, which are amorphous transparent copolymers of ethylene and norbornene prepared by polymerization with a metallocene catalyst. These commercially available COCs are reported to have high transparency and gloss, excellent moisture-barrier and odor-barrier properties, a variable glass transition point between 50 °C and 178 °C (such as 65 °C to 178 °C), high stiffness, high strength, excellent biocompatibility and inertness, and easy thermoformability. The COC can be blended with PP.

[0035] The layer of the film containing COC may contain any suitable amount of COC. In some embodiments, the COC is present in the layer in an amount between about 5 wt% and about 35 wt%, such as about 10 wt% to about 30 wt%, about 15 wt% to about 25 wt%, or about 20 wt%. In some embodiments, the layer of the film containing COC contains at least 50 wt% of PP.

[0036] Tackifier

[0037] The blends and layers described herein can include any suitable tackifier. For the purposes of this disclosure, "tackifier" and "hydrocarbon resin" are used interchangeably. The tackifier can be present in the blends and layers in any suitable amount. In embodiments, the tackifier is present in the blend or layer in an amount of 5 wt% or greater ("at least 5 wt%"), 10 wt% or greater, 15 wt% or greater, or 20 wt% or greater. In embodiments, the tackifier is present in the blend of the layer in an amount of 60 wt% or less, 50 wt% or less, or 40 wt% or less. In embodiments, the blend or layer comprises 5 wt% to 60 wt% of a tackifier, such as 5 wt% to 50 wt% of a tackifier, 5 wt% to 40 wt% of a tackifier, 10 wt% to 60 wt% of a tackifier, 10 wt% to 50 wt% of a tackifier, 10 wt% to 40 wt% of a tackifier, 15 wt% to 60 wt% of a tackifier, 15 wt% to 50 wt% of a tackifier, 15 wt% to 40 wt% of a tackifier, 20 wt% to 60 wt% of a tackifier, 20 wt% to 50 wt% of a tackifier, 20 wt% to 40 wt% of a tackifier, 10 wt% to 25 wt% of a tackifier, 15 wt% to 20 wt% of a tackifier, and the like.

[0038] The blend or layer can include any suitable tackifier. Suitable tackifiers include aliphatic hydrocarbon resins, at least partially hydrogenated aliphatic hydrocarbon resins, aliphatic / aromatic hydrocarbon resins, at least partially hydrogenated aliphatic aromatic hydrocarbon resins, aromatic resins, at least partially hydrogenated aromatic hydrocarbon resins, alicyclic hydrocarbon resins, at least partially hydrogenated alicyclic resins, alicyclic / aromatic hydrocarbon resins, alicyclic / aromatic at least partially hydrogenated hydrocarbon resins, polyterpene resins, terpene-phenol resins, rosin esters, rosin acids, graft resins, and mixtures of two or more of the foregoing. The hydrocarbon resin can be polar or nonpolar.

[0039] The tackifier can be a low molecular weight product (molecular weight less than about 10,000 daltons) produced by polymerization from coal tar, petroleum, citrus, or turpentine feedstocks.

[0040] The tackifier may comprise any hydrocarbon resin disclosed in U.S. Patent No. 6,432,496 issued on August 13, 2002 or U.S. Patent Application 2008 / 0286547 published on November 20, 2008, both of which are incorporated herein by reference in their entirety. More specifically, by way of non-limiting example, the tackifier may include petroleum resins, terpene resins, styrene resins, cyclopentadiene resins, saturated alicyclic resins, or mixtures of such resins. Additionally, by way of non-limiting example, the tackifier may comprise hydrocarbon resins derived from the polymerization of an olefin feed rich in dicyclopentadiene (DCPD), the polymerization of an olefin feed produced in a petroleum cracking process (such as a crude C9 feed stream), the polymerization of pure monomers (such as styrene, α-methylstyrene, 4-methylstyrene, vinyltoluene, or any combination of these or similar pure monomer feeds), the polymerization of terpene olefins (such as α-pinene, β-pinene, or d-limonene), or combinations thereof. The hydrocarbon resin may be fully or partially hydrogenated. Specific examples of hydrocarbon resins include, but are not limited to, R1140 hydrocarbon resin available from Synthomer plc (Essex, UK), T1140, P-140 available from Arakawa Chemical Industries, Limited (Osaka, Japan), and S135 polyterpene resin available from Pinova, Inc. (Brunswick, GA).

[0041] Crosslinking agent

[0042] The layers, films, or packages described herein may comprise a crosslinking agent or may be formed from a blend comprising a crosslinking agent. In some embodiments, the layers, films, or packages do not comprise a crosslinking agent. In some embodiments, the layers, films, or packages comprise a reversible crosslinking agent. Suitable reversible crosslinking agents include crosslinking agents that form crosslinks through ionic, hydrophobic, or other secondary interactions rather than through covalent bonds. In some embodiments, the crosslinking agent may increase the melt viscosity and reduce the sag of the film or layer by increasing entanglement through long-chain branching.

[0043] In an embodiment, the crosslinking agent comprises an organic peroxide. A coagent can be used with the organic peroxide. The coagent can be used to reduce breakage and enhance crosslinking. Examples of organic peroxides and coagents are described, for example, in U.S. Patent No. 6,987,149 and Romani et al. (February 2002), Monitoring the chemical crosslinking of propylene polymers through rheology, Polymer 43(4):1115-1131, which is incorporated herein by reference in its entirety to the extent that it does not conflict with the disclosure presented herein.

[0044] In an embodiment, the crosslinking agent produces long-chain branched polypropylene by extrusion (grafting). See, for example, Didier Graebling (2002), Synthesis of Branched Polypropylene by a Reactive Extrusion Process. Macromolecules, American Chemical Society, 35(12):4602-4610, which is incorporated herein by reference in its entirety to the extent that it does not conflict with the disclosure presented herein.

[0045] In an embodiment, the crosslinking agent produces long-chain branched isotactic polypropylene. See, for example, Weng et al. (2002), Long Chain Branched Isotactic Polypropylene, Macromolecules 35(10):3838-3843, DOI:10.1021 / ma020050j, which is incorporated herein by reference in its entirety to the extent that it does not conflict with the disclosure presented herein.

[0046] In an embodiment, the crosslinking agent produces long-chain branched polypropylene by irradiation. See, for example, Krause et al. (January 5, 2006), Long-chain branching of polypropylene by electron-beam irradiation in the molten state, Journal of Applied Polymer Science, 99(1):260-265 and Auhl et al. (November 11, 2004), Long-Chain Branched Polypropylenes by Electron Beam Irradiation and Their Rheological Properties, Macromolecules 37(25):9465-9472, which are incorporated herein by reference in their entirety to the extent that they do not conflict with the disclosure presented herein.

[0047] In an embodiment, the crosslinking agent comprises an ionic crosslinking agent. In an embodiment, the crosslinking agent is an ionic crosslinking agent as described in U.S. Patent No. 9,045,615, which is incorporated herein by reference in its entirety to the extent that it does not conflict with the disclosure presented herein.

[0048] Examples of suitable crosslinking agents that can be used include crosslinking monomers; reactive oligomers; polyisocyanate oligomers; functional crosslinkable polymers; derivatives of ethylene glycol di(meth)acrylate (such as ethylene glycol diacrylate, di(ethylene glycol) diacrylate, tetra(methylene / ethylene glycol) diacrylate, ethylene glycol dimethacrylate (EDMA), di(ethylene glycol) dimethacrylate (DEDMA), tri(methylene / ethylene glycol) dimethacrylate, tetraethylene glycol dimethacrylate (TEDMA)); derivatives of methylenebisacrylamide (such as N,N-methylenebisacrylamide, N,N-methylenebisacrylamide, N,N-(1,2-dihydroxyethylidene)bisacrylamide); formaldehyde-free crosslinking agents (such as N-(1-hydroxy-2,2-dimethoxyethyl)acrylamide); divinylbenzene; divinyl ether; diallyl phthalate; divinyl sulfone, etc.

[0049] In some embodiments, the crosslinking agent is an ionic crosslinking agent comprising a polyvalent metal oxide crosslinking agent, such as lead oxide, magnesium oxide, barium oxide, zinc oxide, manganese oxide, copper oxide, aluminum oxide, nickel oxide, or combinations thereof. In some embodiments, the ionic crosslinking agent comprises zinc hydroxide, aluminum hydroxide, magnesium hydroxide, or other metal hydroxides, such as barium hydroxide, manganese hydroxide, copper hydroxide, and nickel hydroxide. In embodiments, the ionic crosslinking agent comprises crosslinking monomers, reactive oligomers, polyisocyanate oligomers, functional crosslinkable polymers, derivatives of ethylene glycol di(meth)acrylate (such as ethylene glycol diacrylate, di(ethylene glycol) diacrylate, tetra(methylene / ethylene glycol) diacrylate, ethylene glycol dimethacrylate (EDMA), di(ethylene glycol) dimethacrylate (DEDMA), tri(methylene / ethylene glycol) dimethacrylate, tetraethylene glycol dimethacrylate (TEDMA)), derivatives of methylene bisacrylamide (such as N,N-methylenebisacrylamide, N,N-methylenebisacrylamide, N,N-(1,2-dihydroxyethylidene)bisacrylamide), formaldehyde-free crosslinking agents (such as N-(1-hydroxy-2,2-dimethoxyethyl)acrylamide), divinylbenzene, divinyl ether, diallyl phthalate, divinyl sulfone, etc. Combinations of these crosslinking agents can also be used.

[0050] In some embodiments, the crosslinking agent is zinc diacrylate salt. Examples of zinc diacrylate salt are the 9200 ionomeric diacrylate functional monomers available from Total (TotalEnergies) to modify polyolefins such as polypropylene.

[0051] The layers, films, or packages described herein, or blends used to prepare layers, films, or packages, can contain any suitable amount of crosslinking agent. In embodiments, the crosslinking agent is present in the blend or layer in an amount of 0.5 wt% or greater (“at least 0.5 wt%”), 1 wt% or greater, 1.5 wt% or greater, or 2 wt% or greater. In embodiments, the crosslinking agent is present in the blend of the layer in an amount of 10 wt%, 7.5 wt% or less, or 5 wt% or less. In embodiments, the blend or layer contains 0.5 wt% to 6 wt% of the crosslinking agent, such as 0.5 wt% to 5 wt% of the crosslinking agent, 0.5 wt% to 4 wt% of the crosslinking agent, 1 wt% to 6 wt% of the crosslinking agent, 1 wt% to 5 wt% of the crosslinking agent, 1 wt% to 4 wt% of the crosslinking agent, 1.5 wt% to 6 wt% of the crosslinking agent, 1.5 wt% to 5 wt% of the crosslinking agent, 1.5 wt% to 4 wt% of the crosslinking agent, 2.0 wt% to 6 wt% of the crosslinking agent, 2 wt% to 5 wt% of the crosslinking agent, 2 wt% to 4 wt% of the crosslinking agent, 1 wt% to 2.5 wt% of the crosslinking agent, 1.5 wt% to 2 wt% of the crosslinking agent, 1 wt% to 3 wt% of the crosslinking agent, etc.

[0052] Films and Recyclable Films and Packaging

[0053] The thermoformable films and capping films described herein can be fully co-extruded or can be produced by other methods such as lamination or coating. Generally, the films described herein can have any suitable thickness. In embodiments, the thickness of the film can be from about 4 mils (102 microns) to about 80 mils (2,032 microns), and such thickness can be suitable for thermoforming. Some packaging applications will benefit from a thermoformable base film having a thickness of from about 8 mils (203 microns) to about 50 mils (1,270 microns). In some embodiments, the thickness of the film is from about 8 mils (203 microns) to about 25 mils (635 microns).

[0054] The films and packaging described herein are preferably suitable for recycling. For a film or packaging to be suitable for recycling, the overall composition of the film or packaging should be suitable for recycling. In embodiments, the film has an overall composition suitable for recycling in processes that typically accept polypropylene-based materials. Some recycling streams that accept PP-based materials can accept mixed polyolefin-based materials, such as PP-based materials and polyethylene-based materials.

[0055] The films described herein can be recycled after their primary use is complete. As used herein, the term "suitable for recycling" is intended to indicate that the film can be converted into new useful articles by reprocessing in a polyolefin recycling stream (e.g., a PP-based recycling stream). Reprocessing may require washing, separation, melting, and forming, among many other steps. Generally, when plastic packaging is recycled by reprocessing, the material is mechanically chopped into small pieces, melted, mixed, and reformed into a new product. If there are multiple incompatible materials in the packaging, interactions occur during reprocessing, resulting in gels, brittle materials, poor appearance, and generally unusable or low-quality products. The use of the term "recyclable" indicates that these drawbacks are generally absent. The qualification of recyclable materials is not regulated by any specific agency but can be obtained from specific groups such as the Association of Plastic Recyclers (APR) and How2Recycle TM and the like. The recyclable films disclosed herein can be suitable for PP-based recycling streams. In some embodiments, introducing the recyclable film into any of these recycling-reprocessing pathways may not require an additional compatibilizer.

[0056] Suitability for recycling can be achieved by keeping the total amount of PP in the overall composition of the film or packaging high. Any additives used should be kept to a minimum. Any non-PP-based polymers present can be accompanied by a compatibilizer to achieve a composition suitable for recycling.

[0057] In some embodiments, the films or packages described herein include 50 wt% or more (“at least 50 wt%”) of PP, such as at least 60 wt% of PP, at least 70 wt% of PP, at least 80 wt% of PP, or at least 90 wt% of PP.

[0058] In a further effort to achieve a total composition suitable for recycling, some embodiments of the film or package are free or substantially free of polyester materials. Polyester materials are commonly used in films due to their ease of thermoforming, stiffness, and clarity. However, the presence of polyester can greatly hinder the recyclability of the film or package. In some embodiments, the film or package contains less than 20 wt% of polyester, such as less than 10 wt% of polyester, less than 5 wt% of polyester, or less than 1 wt% of polyester.

[0059] In a further effort to achieve a total composition suitable for recycling, some embodiments of the film or package are free or substantially free of EVOH materials. EVOH is commonly used in films because it is a thermoformable oxygen barrier material. However, the presence of EVOH can greatly hinder the recyclability of the film or package. In some embodiments, the film or package contains less than 10 wt% of EVOH, less than 5 wt% of EVOH, or less than 1 wt% of EVOH.

[0060] In a further effort to achieve a total composition suitable for recycling, some embodiments of the film or package are free or substantially free of polyamide materials. Polyamide materials are commonly used due to their ease of thermoforming, durability, and stiffness. However, the presence of polyamide can greatly hinder the recyclability of the film or package. In some embodiments, the film or package contains less than 20 wt% of polyamide, such as less than 10 wt% of polyamide, less than 5 wt% of polyamide, or less than 1 wt% of polyamide.

[0061] The films described herein may be free of polyester, EVOH, and polyamide. In some embodiments, the film contains less than 20 wt% in total of polyester, EVOH, and polyamide, such as less than 10 wt% in total of polyester, EVOH, and polyamide, less than 5 wt% in total of polyester, EVOH, and polyamide, or less than 1 wt% in total of polyester, EVOH, and polyamide.

[0062] In some embodiments, the film includes one or more oxygen barrier layers. In an embodiment, the oxygen barrier layer is the inner layer of the film. The oxygen barrier layer contains materials known to limit the transmission of oxygen through the film. One option for the oxygen barrier material is EVOH. In some cases, EVOH may be present together with a compatibilizer that allows EVOH to be incorporated into the PP recycle stream.

[0063] As used herein, "EVOH" refers to ethylene vinyl alcohol copolymer. EVOH is also known as saponified or hydrolyzed ethylene vinyl acetate copolymer and refers to a vinyl alcohol copolymer having ethylene comonomer. EVOH is prepared by hydrolysis (or saponification) of ethylene-vinyl acetate copolymer. EVOH is commercially available in resin form with various percentages of ethylene. Preferably, the ethylene / vinyl alcohol copolymer contains about 27-38 mol% ethylene or even 27-29 mol% ethylene.

[0064] The membranes described herein may include one or more tie layers. The tie layers bond to different layers. For example, a tie layer may be used to bond an EVOH layer to a PP layer. The need for a tie layer depends on the materials in the adjacent layers. Tie layers based on PP copolymers are generally suitable for the membranes described herein.

[0065] Thermoformable film

[0066] At least one layer of the thermoformable film described herein contains at least 50 wt% of PP and (a) a tackifier and / or (b) COC. The layer may also contain a crosslinking agent. The layer may contain weight percentages of the different components as described above. In an embodiment, the layer is the inner layer of the thermoformable film. As used herein, the "inner" layer of the film is the layer located between two other layers of the film.

[0067] The thermoformable film may further include one or more additional layers. In some embodiments, the thermoformable film includes an outer layer. The outer layer forms the surface of the film. The outer layer may contain at least 50 wt% of PP, such as at least 60 wt% of PP, at least 70 wt% of PP, at least 80 wt% of PP, at least 90 wt% of PP or at least 95 wt% of PP. The outer layer may consist essentially of PP. The outer layer may contain 99.9 wt% or less of PP. The film may include two outer layers. Each outer layer may be the same or different. In an embodiment, each outer layer is the same or substantially the same.

[0068] In an embodiment, the outer layer comprises a blend of PP and polyolefin elastomer (POE). In an embodiment, the blend comprises at least 50 wt% of PP. The outer layer can comprise any suitable POE. POE is an ethylene-based or propylene-based random copolymer produced by a single-site catalyst that bridges the performance gap between conventional polyolefins such as polyethylene or polypropylene and conventional elastomers such as ethylene propylene diene monomer (EPDM). See, e.g., Mark, J. (Ed.). (1999). *Polymer Data Handbook*. Oxford University Press. Any suitable catalyst such as a metallocene catalyst or a Ziegler-Natta catalyst can be used to produce POE. The density of POE is typically less than 0.886 g / cm 3 . Ethylene-based POE can have 65 wt% to 91 wt% ethylene and 9 wt% to 35 wt% linear alpha-olefin (LAO). LAO such as butene-1, hexene-1, or octene-1 can be used. Although incorporation of other comonomers and amounts is possible, propylene-based POE typically has 70 wt% to 90 wt% propylene and 10 wt% to 30 wt% ethylene or butene-1. POE can be produced by any suitable process such as a solution process, a gas-phase reactor process, and an autoclave process. In some embodiments, the POE is a propylene-based POE. In some embodiments, the POE comprises a propylene random copolymer.

[0069] As used herein, the term "layer" refers to a building block of a film, which is a structure of a single material type or a homogeneous blend of materials. Although the composition of the layer can be different, the composition of the layer is consistent throughout (i.e., the layer is not stratified). The film comprises one or more layers connected to each other. The layer can contain a single polymer, a blend of materials within a single polymer type, or a blend of various polymers (e.g., polypropylene), or a blend of various polymer types, can contain metallic materials or other non-polymeric materials, and can have additives. The layer can be continuous with the film, or can be discontinuous or patterned compared to the film. The film has two surfaces opposite each other. The layer at the surface of the film is not connected to another layer of the film at that surface.

[0070] The heat - formable film can be suitable for thermoforming on a form / fill / seal line with a short forming dwell time to maintain a suitable line speed. In some embodiments, the heat - formable films described herein are suitable for thermoforming where the pre - heat dwell time is ten seconds or less, such as five seconds or less, two seconds or less, one second or less, or 0.5 seconds or less. The pre - heating can be done in one or more zones of an indexing machine, and the pre - heat dwell time can be the sum of the dwell times in the one or more zones including the pre - heating. A thermoforming temperature window of about 5 °C can be considered the practical lower limit for thermoforming on high - speed form / fill / seal equipment having such a forming dwell time. As described in the following examples, the thermoforming temperature window of a polypropylene homopolymer control film is about 3 °C, which is too low to be practically used for thermoforming on large - scale commercial form / fill / seal equipment. In some embodiments, the thermoforming temperature window of the layer or film comprising the layer described herein is 5 °C or higher, such as 10 °C or higher or 15 °C or higher. Such a thermoforming temperature window can allow for practical thermoforming on a large commercial scale with short forming dwell times.

[0071] The thermoforming temperature window of a film can be determined by visually inspecting the articles thermoformed from the film at various temperatures. The minimum temperature of the thermoformed temperature window can be considered the lowest temperature at which a complete defect - free article is formed. The maximum temperature of the thermoforming temperature window can be considered the temperature at which the thermoformed article begins to melt, deform, or have poor aesthetics.

[0072] The thermoformable films described herein have one or more other properties suitable for thermoforming. For example, the films can have suitable sag resistance and other properties such as toughness or impact strength for practical use in thermoforming. Layers and films containing a sufficiently large tensile viscosity can have sufficient sag resistance for practical use in thermoforming, specifically in form / fill / seal equipment. In embodiments, the thermoformable film has a tensile viscosity of 500,000 Pa s or greater in the machine direction, such as 600,000 Pa s or greater, 700,000 Pa s or greater, 800,000 Pa s or greater, 900,000 Pa s or greater, or 1,000,000 Pa s or greater in the machine direction. In embodiments, the thermoformable film has a tensile viscosity of 500,000 Pa s or greater in the transverse direction, such as 600,000 Pa s or greater, 700,000 Pa s or greater, 800,000 Pa s or greater, 900,000 Pa s or greater, or 1,000,000 Pa s or greater in the transverse direction. The tensile viscosity of the layer and film in both the machine direction and the transverse direction can be 500,000 Pa s or greater, such as 600,000 Pa s or greater, 700,000 Pa s or greater, 800,000 Pa s or greater, 900,000 Pa s or greater, or 1,000,000 Pa s or greater in both the machine direction and the transverse direction. The tensile viscosity can be measured using a TA Instruments Discovery Hybrid Rheometer (DHR)-2 equipped with a SER3 Universal Testing Platform.

[0073] The extensional viscosity can be measured as follows. The sample can be compression molded from pellets into a 2 mm thick film. The pellets can be melted at 210 °C for 5 minutes with the mold kept in contact with both the top and bottom plates. Then, a pressure of 20,000 pounds can be applied for 2 minutes. The sample can be removed and placed in a 23 °C press at a pressure of 10,000 pounds to cool. The sample can then be removed from the mold and conditioned at 23 °C and 50% humidity for 24 hours, and then the extensional viscosity can be measured. Sample strips measured as 4 mm × 12 mm strips can be cut from the compression molded 2 mm film. These can each be loaded into a TA Instruments DHR-2 hybrid rheometer with a SER3 universal test platform attachment. The sample can receive a temperature soak at 170 °C for 300 seconds, and then an extension rate of 0.1 s-1 at 170 °C can be applied until a final strain of 4.0 is reached. The peak extensional viscosity measured according to this method can be reported as the extensional viscosity value. The method and apparatus (Sentmanat extensional rheometer) for measuring extensional viscosity are also described in U.S. Patent Nos. 6,578,413 and 6,691,569, the contents of which are incorporated herein by reference in their entirety to the extent that they do not conflict with the disclosure presented herein.

[0074] The thermoformable films described herein can comprise any suitable number of layers. In embodiments, the thermoformable film has 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, or more layers. In some embodiments, the thermoformable film has at least three layers.

[0075] When the film comprises more than one layer, the outer (and other) layers are preferably thinner than the inner layer comprising at least 50% PP and (a) a tackifier and / or (b) COC. The inner layer can have sufficient extensional behavior to compensate for defects in the other layers (e.g., layers comprising PP but no tackifier or COC). By making the other layers thinner, heat can more easily penetrate to the inner layer during thermoforming. In embodiments, the surface layer (or outer layer) of the film is each about 10% to about 15% of the total thickness of the film.

[0076] In some embodiments, and with reference to Figure 1, the heat - formable film 10 comprises three layers: a first layer 20, a second layer 30, and a third layer 40. The second layer 30 is located between the first layer 20 and the third layer 40. The second layer 30 may comprise at least 50 wt% of PP and (a) a tackifier and / or (b) a COC. The second layer 30 may or may not comprise a cross - linker. The second layer 30 may or may not comprise impact - modified PP. In some embodiments, the first layer 20 and the third layer 40 are PP layers. The first layer 20 and the third layer 40 may comprise 50 wt% or more of PP, 60 wt% or more of PP, 70 wt% or more of PP, 80 wt% or more of PP, 90 wt% or more of PP, or 95 wt% or more of PP. In some embodiments, the first layer 20 and the third layer 40 consist of or consist essentially of PP. The first layer 20 and the third layer 40 may be the same or different. In some embodiments, the first layer 20 and the third layer 40 are the same in composition.

[0077] In some embodiments, and referring to Figure 2 , the heat - formable film 10 comprises six layers. The second layer 30 may comprise at least 50 wt% of PP and (a) a tackifier and / or (b) a COC. The second layer 30 may or may not comprise a cross - linker. The second layer 30 may or may not comprise impact - modified PP. In some embodiments, the first layer 20 and the sixth layer 70 are PP layers. The first layer 20 and the sixth layer 70 may comprise 50 wt% or more of PP, 60 wt% or more of PP, 70 wt% or more of PP, 80 wt% or more of PP, 90 wt% or more of PP, or 95 wt% or more of PP. In some embodiments, the first layer 20 and the sixth layer 70 consist of or consist essentially of PP. The first layer 20 and the sixth layer 70 may be the same or different. In some embodiments, the first layer 20 and the sixth layer 70 are the same in composition.

[0078] Still referring to Figure 2 , the fourth layer 50 may be a barrier layer. In some embodiments, the fourth layer 50 is an EVOH layer. The third layer 40 and the fifth layer 60 may be tie layers. The tie layer may be a PP copolymer layer. The third layer 40 and the fifth layer 60 may be the same or different. In some embodiments, the third layer 40 and the fifth layer 60 are the same in composition.

[0079] In some embodiments, and referring to Figure 3, the heat - formable film 10 comprises seven layers. The second layer 30 and the sixth layer 70 may comprise at least 50 wt% of PP and (a) a tackifier and / or (b) COC. The second layer 30 and the sixth layer 70 may or may not comprise a cross - linker. The second layer 30 and the sixth layer 70 may or may not comprise impact - modified PP. The second layer 30 and the sixth layer 70 may be the same or different. In some embodiments, the second layer 30 and the sixth layer 70 are the same. In some embodiments, the first layer 20 and the seventh layer 80 are PP layers. The first layer 20 and the seventh layer 80 may comprise 50 wt% or more of PP, 60 wt% or more of PP, 70 wt% or more of PP, 80 wt% or more of PP, 90 wt% or more of PP, or 95 wt% or more of PP. In some embodiments, the first layer 20 and the seventh layer 80 consist of or consist essentially of PP. The first layer 20 and the seventh layer 80 may be the same or different. In some embodiments, the first layer 20 and the seventh layer 80 are the same.

[0080] Still referring to Figure 3 , the fourth layer 50 may be a barrier layer. In some embodiments, the fourth layer 50 is an EVOH layer. The third layer 40 and the fifth layer 60 may be tie layers. The tie layer may be a PP copolymer layer. The third layer 40 and the fifth layer 60 may be the same or different. In some embodiments, the third layer 40 and the fifth layer 60 are the same.

[0081] In some embodiments, and referring to Figure 4 , the film 10 comprises eight layers. The second layer 30 and the sixth layer 70 may comprise at least 50 wt% of PP and (a) a tackifier and / or (b) COC. The second layer 30 and the sixth layer 70 may or may not comprise a cross - linker. The second layer 30 and the sixth layer 70 may or may not comprise impact - modified PP. The second layer 30 and the sixth layer 70 may be the same or different. In some embodiments, the second layer 30 and the sixth layer 70 are the same. In some embodiments, the first layer 20 is a PP layer. The first layer 20 may comprise 50 wt% or more of PP, 60 wt% or more of PP, 70 wt% or more of PP, 80 wt% or more of PP, 90 wt% or more of PP, or 95 wt% or more of PP.

[0082] Still referring to Figure 4, the fourth layer 50 can be a barrier layer. In some embodiments, the fourth layer 50 is an EVOH layer. The third layer 40, the fifth layer 60, and the seventh layer 80 can be tie layers. The tie layer can be a PP copolymer layer. The third layer 40, the fifth layer 60, and the seventh layer 80 can be the same or different. In some embodiments, the third layer 40, the fifth layer 60, and the seventh layer 80 are the same. The eighth layer 90 can be a sealing layer. The sealing layer can comprise polyethylene and / or polypropylene materials. Examples of suitable polymers for polyethylene sealing layers include polyethylene homopolymers such as low density polyethylene; ethylene α-olefin copolymers such as linear low density polyethylene; ethylene vinyl acetate copolymers; ethylene alkyl acrylate copolymers such as ethylene methyl acrylate copolymer; copolymers of ethylene and ethylenically unsaturated carboxylic acids such as ethylene acrylic acid copolymer and ethylene methacrylic acid copolymer, ionomers, and combinations thereof.

[0083] In some embodiments, and referring to Figure 5 , the film 10 comprises seven layers. The second layer 30 can comprise at least 50 wt% of PP and (a) a tackifier and / or (b) COC. The second layer 30 can comprise or can not comprise a crosslinking agent. The second layer 30 can comprise or can not comprise impact PP. In some embodiments, the first layer 20, the third layer 40, and the seventh layer 80 are PP layers. The first layer 20, the third layer 40, and the seventh layer 80 can be the same or different. In embodiments, the first layer 20, the third layer 40, and the seventh layer 80 are the same. In embodiments, the third layer 40 and the seventh layer 80 are the same. The first layer 20, the third layer 40, and the seventh layer 80 can comprise 50 wt% or more of PP, 60 wt% or more of PP, 70 wt% or more of PP, 80 wt% or more of PP, 90 wt% or more of PP, or 95 wt% or more of PP. In embodiments, the first layer 20, the third layer 40, and the seventh layer 80 consist of or consist essentially of PP. The fifth layer 60 can be an EVOH layer. The fourth layer 50 and the sixth layer 70 can be tie layers. The tie layer can be a PP copolymer layer. The fourth layer 50 and the sixth layer 70 can be the same or different. In some embodiments, the fourth layer 50 and the sixth layer 70 are the same.

[0084] In some embodiments, Figure 5 the third layer 40 to the seventh layer 80 of the film 10 depicted in can comprise a blown film 15. The blown film 15 can be prepared in any suitable manner. For example, the blown film 15 can be prepared by a standard blown film coextrusion process, collapsing the bubble into a single palindromic film. The film comprising the first layer 20 and the second layer 30 can be coated on the blown film 15 to produce the final film 10.

[0085] In some embodiments, and referring to Figure 6, the film 10 comprises eight layers. In an embodiment, the first layer 20, the second layer 30, the third layer 40, the fourth layer 50, the fifth layer 60, the sixth layer 70, and the seventh layer 80 are the same as those depicted and discussed with respect to Figure 5 In some of the embodiments depicted in Figure 6 , the eighth layer 90 is a PP layer. The eighth layer 90 may be the same as or different from the first layer 20. In an embodiment, the eighth layer 90 is the same as the first layer 20. The eighth layer 90 may be coated on the blown film 15.

[0086] In some embodiments, and with reference to Figure 7 , the film 10 comprises eleven layers. In some embodiments, the film 10 is prepared by forming a blown film 15 and coating films 13 and 17 on the blown film 15. Films 13 and 17 may be the same or different. In an embodiment, films 13 and 17 are the same. For example, the second layer 30 and the tenth layer 110 may comprise at least 50 wt% of PP and (a) a tackifier and / or (b) a COC. The second layer 30 and the tenth layer 110 may or may not comprise a crosslinking agent. The second layer 30 and the tenth layer 110 may or may not comprise impact-resistant PP. The second layer 30 and the tenth layer 110 may be the same or different.

[0087] In some embodiments, the first layer 20, the third layer 40, the ninth layer 100, and the eleventh layer 120 are PP layers. The first layer 20, the third layer 40, the ninth layer 100, and the eleventh layer 120 may comprise 50 wt% or more of PP, 60 wt% or more of PP, 70 wt% or more of PP, 80 wt% or more of PP, 90 wt% or more of PP, or 95 wt% or more of PP. In some embodiments, the first layer 20, the third layer 40, the ninth layer 100, and the eleventh layer 120 consist of or consist essentially of PP. The first layer 20, the third layer 40, the ninth layer 100, and the eleventh layer 120 may be the same or different. In some embodiments, the first layer 20 and the third layer 40 are the same, and the ninth layer 100 and the eleventh layer 120 are the same.

[0088] In some embodiments, Figure 5 the fourth layer 50 to the eighth layer 90 of the film 10 depicted in

[0089] It should be understood that Figures 1-7The film 10 depicted is merely several of many possible thermoformable films prepared in accordance with the teachings provided herein. Regarding Figures 1-7 The film 10 depicted and discussed, as well as many other films, can be used as the base film for thermoformed articles such as packaging assemblies.

[0090] Thermoformed packaging assemblies and packaged products

[0091] The films described herein having a layer comprising at least 50 wt% of PP and (a) a tackifier and / or (b) COC can be base films suitable for packaging products. The lid film can be heat-sealed to the thermoformed base packaging assembly made from the thermoformable base film, thereby producing a packaging that can be accepted during the recycling process. The packaging can be suitable for products such as, but not limited to, pharmaceuticals, nutritional foods, medical products, fresh foods, refrigerated foods, shelf-stable foods, consumer goods, cosmetics, and chemicals.

[0092] The packaging described herein incorporates at least two packaging assemblies. First is a thermoformed base assembly made from a PP-based film. The thermoformed cavity can be deep or shallow and is generally formed to accommodate the intended product therein. The thermoformable base film should have a certain thickness to provide the desired hardness (i.e., stiffness), durability, and barrier during thermoforming. Second is the lid packaging assembly. The lid is configured from a film capable of hermetically heat-sealing to the thermoformed base assembly, thereby producing a protective packaging for the product.

[0093] In some embodiments of the packaging, a lid assembly having a high PP composition can be used in combination with the thermoformed base. The combination of the thermoformed base assembly and the lid packaging assembly can provide a highly uniform polymer composition (primarily comprising PP), offering the opportunity to recycle the entire packaging in a single stream.

[0094] The packaging assemblies described herein are unique in that they are produced using a high level of PP but retain the high-performance characteristics required for demanding thermoformed packaging applications. The hermetically sealed packaging can provide excellent product protection, good appearance, good forming accuracy and consistency, good heat resistance, and good seal strength. Packaging with these performance levels has not previously been delivered using materials that can be easily recycled in the PP recycling stream.

[0095] The thermoformable base film can be formed into a packaging component (the thermoformed base) and used in combination with other packaging components, such as a lid, to produce a package. The thermoformed base can be produced from the thermoformable base film by a thermoforming process using heat and pressure (mechanical and / or vacuum). The thermoformed base can be highly rigid and non-flexible, or the thermoformed base can be flexible while still maintaining the thermoformed shape. The thermoformed bases described herein have at least one cavity for receiving a product and a flange surrounding each of the cavities. The flange is typically an unformed area of the film and serves as a location for attaching the thermoformed base to other packaging components, which can be a lid, another thermoformed base component, or some other packaging component.

[0096] Examples of thermoformed bases are shown in Figures 8-10 In the embodiment depicted in Figures 8-10 the thermoformed base 200 has a plurality (10 or 12) of small cavities 210 surrounded by a flange 220. The size of such cavities can be specifically adapted to receive individual pharmaceutical tablets or capsules. Alternatively, the cavities of the thermoformed base can be larger and accommodate multiple product pieces. The present disclosure contemplates cavities of all numbers, sizes, and shapes.

[0097] Each cavity 210 present is surrounded by a flange 220, as shown in the Figure 10 packaged product embodiment of. The flange 220 of the thermoformed base 200 should be an area without curvature for attachment to another packaging component, such as a lid packaging component 300. A product 500 is encapsulated in each cavity. The lid 300 component can be hermetically sealed to the flange 220 in the area around each of the cavities 210 in the thermoformed base 200. Alternatively, the lid 300 can be attached to the thermoformed base 200 at the flange 220 in an area including the entire perimeter surrounding all of the cavities 210 rather than between each of the cavities 210.

[0098] The thermoformed base can be attached to another packaging component by a seal, preferably a hermetic seal. In this way, the product inside the package is completely encapsulated in the cavity and protected by the thermoformed base and the other packaging component. Exchange of gases, liquids, microorganisms, or other materials is limited to those that can pass through the packaging components, as the hermetic seal does not allow passage in the space between the components.

[0099] The products accommodated in the cavities of the thermoformed base are not limited. The products may be environmentally sensitive, such as pharmaceuticals or food. The products may require physical protection, such as delicate medical devices. It may be necessary to accommodate the products for consumer protection, such as pharmaceuticals or cleaners that should be in child-resistant packaging. Products such as chewing gum or candy can be suitable for easy dispensing.

[0100] If the packaged product includes a lid packaging component, the lid can be of any composition suitable for the application. The lid should have a heat-sealable outer layer configured such that it can be easily attached to the thermoformed base by heat-sealing. The seal between the lid packaging component and the thermoformed base can be peelable (i.e., easily separable by hand, with a peel strength of less than about 2,500 g / in) or fused.

[0101] If the lid is fused-sealed to the thermoformed base, the lid can be configured and / or designed such that the product can be pushed through the lid for dispensing. Specifically, for applications of packaged products including pharmaceutical tablets, films, etc., the cavity of the thermoformed base can be flexible enough such that a consumer can manually press on the cavity, forcing the product through the lid assembly for dispensing.

[0102] The lid packaging component can have a moisture and / or oxygen barrier that performs similarly to the thermoformed base. Materials commonly used for high-performance caps include, but are not limited to, metal layers or paper layers. The metal and / or paper layer can be laminated or otherwise attached to a polymer layer including a heat-sealing layer. The lid can be printed, scored, or otherwise modified for specific properties.

[0103] Any suitable capping film can be used as the cap for the packaging. In some embodiments, the capping film includes a capping film outer layer, a sealing layer, and a capping film inner layer located between the capping film outer layer and the sealing layer. The sealing layer can be heat-sealed to the thermoformable film to form a sealed package.

[0104] The capping film can include any suitable capping outer layer. In some embodiments, the capping outer layer includes 50 wt% or more of PP, such as 60 wt% or more of PP, 70 wt% or more of PP, 80 wt% or more of PP, 80 wt% or more of PP, or 95 wt% or more of PP. The capping outer layer can consist of or consist essentially of PP. In some embodiments, the capping outer layer includes 99.9 wt% or less of PP.

[0105] The capping outer layer can or can not include COC. The capping outer layer can include any suitable amount of COC. In some embodiments, COC is present in the capping outer layer in an amount between about 5 wt% and about 50 wt%, such as about 10 wt% to about 45 wt%, about 15 wt% to about 35 wt%, or about 30 wt%.

[0106] The inner sealant layer may or may not contain a tackifier. The inner sealant layer may contain any suitable tackifier. Examples of suitable tackifiers are discussed above under the heading "Tackifiers". The inner sealant layer may contain any suitable amount of tackifier. For example, the inner sealant layer may contain from 5 wt% to 50 wt% of tackifier, from 5 wt% to 40 wt% of tackifier, from 10 wt% to 60 wt% of tackifier, from 10 wt% to 50 wt% of tackifier, from 10 wt% to 40 wt% of tackifier, from 15 wt% to 60 wt% of tackifier, from 15 wt% to 50 wt% of tackifier, from 15 wt% to 40 wt% of tackifier, from 20 wt% to 60 wt% of tackifier, from 20 wt% to 50 wt% of tackifier, from 20 wt% to 40 wt% of tackifier, from 10 wt% to 25 wt% of tackifier, from 15 wt% to 20 wt% of tackifier, etc.

[0107] The cap seal layer contains a polyolefin plastomer (POP). The POP is similar to POE, except that the POP has a higher density than the POP.

[0108] The cap seal layer may contain any suitable POP. The POP is a single-site catalyst-produced ethylene-based or propylene-based random copolymer that bridges the performance gap between conventional polyolefins such as polyethylene or polypropylene and conventional elastomers such as ethylene propylene diene monomer (EPDM). See, for example, Mark, J. (Ed.). (1999). Polymer Data Handbook. Oxford University Press. Any suitable catalyst such as a metallocene catalyst or a Ziegler-Natta catalyst can be used to produce the POP. The density of the POP generally ranges from 0.855 g / cm 3 and 0.912 g / cm 3 3. Ethylene-based POP may have 65 wt% to 91 wt% ethylene and 9 wt% to 35 wt% linear alpha-olefin (LAO). LAOs such as butene-1, hexene-1, or octene-1 can be used. Propylene-based POP generally has 70 wt% to 90 wt% propylene and 10 wt% to 30 wt% ethylene or butene-1. Any suitable process can be used to produce the POP. Examples of suitable processes include solution processes, gas phase reactor processes, and autoclave processes. In some embodiments, the POE is a propylene-based POP. In some embodiments, the POP contains a propylene random copolymer. Examples of suitable POPs include grades of Exact (ExxonMobil), Affinity (Dow), Engage (Dow), Versify (Dow), Vistamaxx (ExxonMobil), and Tafmer (Mitsui).

[0109] The capping seal layer may or may not contain a PP copolymer. The capping seal layer may contain any suitable PP copolymer. In some embodiments, the PP copolymer is formed by the polymerization of polypropylene with ethylene or an alpha-olefin having 4 to 12 carbon atoms. In some embodiments, the PP contains ethylene. In an embodiment, the PP contains a comonomer selected from ethylene and an alpha-olefin having 4 to 12 carbon atoms, and the weight percentage of the comonomer is 0.1% to about 20%, such as about 0.5% to about 15%, about 0.5% to about 10%, about 0.5% to about 8%, 1% to about 15%, about 1% to about 10%, about 1% to about 8%, 2% to about 15%, about 2% to about 10% or about 2% to about 8%.

[0110] The PP copolymer as described above is also referred to as a random copolymer (RCP). See, for example, Mark, J. (Ed.). (1999). Polymer Data Handbook. Oxford University Press. In some embodiments, the PP copolymer contains a random copolymer of ethylene or butene-1 and propylene. Heterophasic and impact copolymers are also PP copolymers.

[0111] Preferably, the product sealed between the thermoformed base (e.g., the product in a tray) and the capping can be easily pushed through the capping.

[0112] Preferably, the capping has no score marks or weak lines.

[0113] An example of a lid assembly that can be sealed to a thermoformed base to provide a packaged product is shown in Figure 11 FIG. The lid 300 may have a capping outer layer 310 as described above. The lid 300 may have a capping inner layer 320 as described above. The lid 300 may have a seal layer 330 as described above.

[0114] As Figure 11 shown, one advantage of the lid 300 is that it will have a similar recyclability compared to the thermoformable base film described herein, such that the entire package can be recycled together without separation.

[0115] Certain Definitions

[0116] As used herein, unless the context clearly indicates otherwise, the singular forms "a / an" and "the" include plural referents. Thus, for example, unless the context clearly states otherwise, reference to "structured bottom surface" includes instances having two or more such "structured bottom surfaces".

[0117] As used herein, unless the context clearly indicates otherwise, the term "or" is generally used in its inclusive sense, including "and / or". The term "and / or" means one or all of the listed elements or a combination of any two or more of the listed elements. In some cases herein, the use of "and / or" does not imply that in other cases the use of "or" does not mean "and / or".

[0118] As used herein, terms such as "have / has / having", "include / includes / including / comprise / comprises / comprising" are used in their open, inclusive sense and generally mean "include, but not limited to".

[0119] "Optional" or "optionally" means that the subsequently described event, circumstance or component may or may not occur, and the description includes both the case where the described event, circumstance or component occurs and the case where the described event, circumstance or component does not occur.

[0120] The terms "preferred" and "preferably" refer to embodiments of the present disclosure that may provide certain benefits in certain circumstances. However, in the same or other circumstances, other embodiments may also be preferred. Moreover, 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 present invention.

[0121] For the purposes of the present disclosure, a numerical range recited by endpoints includes all values subsumed within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.). When a value range is "greater than", "less than", etc. a particular value, that value is included within the range.

[0122] For clarity, any directions mentioned herein, such as "top", "bottom", "left", "right", "up", "down", "above", "below" and other directions and orientations, are described with reference to the accompanying drawings and do not limit the actual device or system or the use of the device or system. Many of the devices, articles or systems described herein can be used in multiple directions and orientations.

[0123] As used herein, "providing" an article such as a film means manufacturing, purchasing or otherwise obtaining the article.

[0124] The term "layer" refers to a discrete component of a film having a substantially uniform composition. A layer may or may not be coextensive with the film.

[0125] As used herein, "polymer" refers to a material that is the product of polymerization or copolymerization of natural, synthetic, or a combination of natural and synthetic monomers or comonomers or monomers and comonomers and includes homopolymers, copolymers, terpolymers, etc. A layer may comprise a single polymer, a mixture of polymer and non-polymer materials, a combination of two or more polymers blended together, or a mixture of two or more polymers and non-polymer materials.

[0126] "Polyolefin", "polyethylene", "polypropylene", or "EVOH" includes not only polymers that include repeating units derived from monomers known to polymerize to form polymers of the designated type, but also comonomers, and both unmodified and modified polymers obtained by derivatizing the polymer after its polymerization to add functional groups or moieties along the polymer chain. Additionally, the term identifying a polymer also includes "blends" of such polymers.

[0127] Unless otherwise specified, the percentages of components in blends or layers described herein are expressed as weight percentages.

[0128] Unless otherwise expressly stated, no method set forth herein is intended to be construed as requiring that its steps be performed in a particular order. Accordingly, where a method claim does not actually recite an order to be followed by its steps or where the steps are not otherwise specifically limited to a particular order in the claims or the specification, no particular order should ever be inferred. Any single or multiple recited features or aspects in any one claim may be combined with or permuted with any other recited features or aspects in any other one or more claims.

[0129] It should also be noted that the recitations herein refer to components that are "configured" or "adapted" to function in a specific manner. In this regard, such components are "configured" or "adapted" to embody a specific property or function in a specific manner, where such recitation is a structural recitation and not a recitation of intended use. More specifically, the reference herein to the manner in which a component is "configured" or "adapted" represents the existing physical condition of the component and, accordingly, will be regarded as an express recitation of a structural characteristic of the component.

[0130] References in this specification to "some embodiments", "embodiments", "one embodiment", "one or more embodiments", "the embodiments", "other embodiments", etc., mean that a particular feature, structure, or characteristic described in connection with the embodiments is included in at least one or more embodiments of the present disclosure, but not necessarily all embodiments.

[0131] While the transitional phrase "comprising" may be used to disclose the various features, elements or steps of a particular embodiment, it should be understood that alternative embodiments are implied, including those that may be described using the transitional phrases "consisting of" or "consisting essentially of". Thus, for example, the implied alternative embodiments of a film comprising polypropylene, tie and EVOH layers include embodiments in which the film consists of polypropylene, tie and EVOH layers and embodiments in which the film consists essentially of polypropylene, tie and EVOH layers.

[0132] Incorporated by reference

[0133] For all purposes, all references, articles, publications, patents, patent publications and patent applications cited herein are incorporated herein by reference in their entirety. However, the mention of any reference, article, publication, patent, patent publication and patent application cited herein is not to be taken as and should not be taken as an admission or any form of implication that it constitutes valid prior art or forms part of the common general knowledge in any country in the world.

[0134] Examples

[0135] Example 1: Monolayer film thermoformed on a laboratory line

[0136] The monolayer sample films were formed from four different blends having the compositions shown in Table 1 below, and the sample films were thermoformed in a prototype laboratory using a one-up former. The one-up former has an infrared oven for heating which does not have temperature control. The residence time is used to control the heat received by the film. Once the desired residence time / temperature is reached, a vacuum is formed in the die.

[0137] Table 1: Compositions of monolayer films

[0138] Film Homopolymer PP % Tackifier % Impact Copolymer PP % Crosslinking Agent % COC % 1 100 - - - - 2 70 20 10 - - 3 68.5 20 10 1.5 - 4 80 - - - 20

[0139] Homo-PP = Braskem INSPIRE 6021N, tackifier = available from SI Group R1140 hydrocarbon resin, impact PP = LyondellBasell Adflex Q100F, crosslinker = available from Total (TotalEnergies) 9200 ionomeric diacrylate functional monomer, COC = from Topas Advanced Polymers 5013F-04.

[0141] For each film, a film thermoforming tray was formed on the one-up former using a 7-second residence time. Images of the resulting trays are shown in Figure 12A(Film 1), 12B (Film 2), 12C (Film 3) and 12D (Film 4) are shown. As Figure 12A -D shows, relative to the control sample ( Figure 12A , Film 1), the sample containing the tackifier ( Figure 12B , Film 2) causes significantly improved tray formation, indicating improved thermoformability. The tray formed from the sample containing COC ( Figure 12D , Film 4) looks slightly clearer in contour than the tray formed from the sample containing the tackifier ( Figure 12B , Film 2). The tray formed from the sample containing the tackifier and the crosslinker ( Figure 12C , Film 3) has the clearest contour and the details at the bottom of the tray are more obvious.

[0142] The sag resistance of the four films was tested as follows. The film samples were baked in an oven for a long time to evaluate their sag resistance. After being taken out of the oven, the samples were cooled for 3 minutes to allow sufficient sag to form. Images of the films are shown in Figure 13A (Film 1), 13B (Film 2), 13C (Film 3) and 13D (Film 4), where the residence time was 38 seconds. The sag depth was measured as an index of the sag resistance of each film. Sag resistance. Similar to the Figure 12A -D shown tray, the film with the tackifier and the crosslinker (Film 3) has the best sag resistance, followed by the film with COC (Film 4), the film with the tackifier (Film 2) and the control film (Film 1).

[0143] With the aid of the crosslinker or amorphous COC, the melt strength of Films 2-4 is improved and the sag resistance is also improved.

[0144] Example 2: Thermoform a multilayer film on a commercial line and determine the thermoforming temperature window

[0145] A seven-layer film with different PP blends (the blends listed in Table 1 above for Films 1, 2, 3, and 4) is prepared by co-extrusion. The seven layers of the film are as follows: (1) 10% PP homopolymer (6021N), (2) 35% PP blend (1 / 2 / 3 / 4 blend), (3) 2.5% tie, (4) 5% EVOH, (5) 2.5% tie, (6) 35% PP blend (1 / 2 / 3 / 4 blend), and (7) 10% PP homopolymer (6021N). The film is subjected to thermoforming on a Bosch line former. For all films, zones 1 and 2 are set at 60 °C, and only zones 3, 4, and 5 are adjusted throughout the experiment. Each film is run with a similar pre-heating plate dwell to maintain consistency and comparison (1.64 seconds, top / 1.25 seconds, bottom). The air pressure is maintained between 65 - 85 psi and is adjusted only as needed to optimize the appearance of each film / temperature combination. The quality of the thermoformed articles is visually inspected and determined to be suitable or not. The temperature ranges determined to be suitable for thermoforming each test film are shown in Table 2 below.

[0146] Table 2: Thermoforming Temperature Window

[0147] Film Composition Thermoforming Temperature Window (°C) 1 162 to 165 2 150 to 160 3 150 to 165 4 155 to 165

[0148] As shown in Table 2, for each of the sample films containing blends (2 - 4), the thermoforming temperature window is increased from 3 °C (162 to 165) to 10 °C (150 to 160 or 155 to 165) or 15 °C (150 to 165) relative to the sample film containing homopolymer PP (no tackifier, no crosslinker, no impact PP, and no COC). The widest thermoforming temperature window is obtained with the blend containing a tackifier and a crosslinker (Film 3). The 10 °C thermoforming temperature window is large enough to allow the practical use of the film to produce thermoformed articles on a form / fill / seal line.

[0149] The thermoforming temperature window is determined by visually inspecting the defects of the thermoformed cups at various temperatures. Those temperatures at which high-quality cups are formed are included within the range shown in Table 2 above.

[0150] Example

[0151] System Example A: A system for forming a blister package, the system comprising:

[0152] A thermoformable film, the thermoformable film comprising a thermoformable film outer layer and a thermoformable film inner layer,

[0153] The thermoformable film outer layer comprises at least 50 wt% polypropylene,

[0154] The heat - formable film inner layer contains at least 50% by weight of polypropylene and (a) a tackifier and / or (b) a cycloolefin copolymer; and

[0155] A capping film, the capping film comprising a capping film outer layer, a capping film inner layer, and a sealing layer,

[0156] The capping film outer layer contains at least 50% of polypropylene,

[0157] The capping film inner layer contains at least 50% of polypropylene and a tackifier,

[0158] The sealing layer contains a polyolefin plastomer.

[0159] System Example B: The system according to System Example A, wherein the heat - formable film inner layer contains at least 5% by weight of the tackifier.

[0160] System Example C: The system according to System Example A or B, wherein the heat - formable film inner layer contains 5% to 40% by weight of the tackifier.

[0161] System Example D: The system according to System Example A or B, wherein the heat - formable film inner layer contains 10% to 25% by weight of the tackifier.

[0162] System Example E: The system according to System Example A or B, wherein the heat - formable film inner layer contains 15% to 20% by weight of the tackifier.

[0163] System Example F: The system according to any of the foregoing system examples, wherein the heat - formable film inner layer further contains a cross - linker.

[0164] System Example G: The system according to System Example F, wherein the heat - formable film inner layer contains 0.5% to 5% by weight of the cross - linker.

[0165] System Example H: The system according to System Example F, wherein the heat - formable film inner layer contains 1% to 3% by weight of the cross - linker.

[0166] System Example I: The system according to any one of System Examples F to H, wherein the cross - linker is an ionic cross - linker.

[0167] System Example J: The system according to any of the foregoing system examples, wherein the heat - formable film inner layer contains 5% to 40% by weight of the cycloolefin copolymer.

[0168] System Example K: The system according to any of the foregoing system examples, wherein the heat - formable film outer layer further contains a polyolefin elastomer.

[0169] System Embodiment L: The system according to System Embodiment K, wherein the polyolefin elastomer comprises an atactic propylene copolymer.

[0170] System Embodiment M: The system according to any of the preceding system embodiments, wherein the outer layer of the capping film further comprises a cycloolefin copolymer.

[0171] System Embodiment N: The system according to System Embodiment M, wherein the outer layer of the capping film comprises 5 wt% to 50 wt% of the cycloolefin copolymer.

[0172] System Embodiment O: The system according to any of the preceding system embodiments, wherein the sealing layer further comprises a polypropylene copolymer.

[0173] System Embodiment P: The system according to any of the preceding system embodiments, wherein the polyolefin plastomer of the sealing layer comprises an atactic propylene copolymer.

[0174] Method Embodiment A: A method comprising:

[0175] Providing a system according to any of the preceding system embodiments;

[0176] Thermoforming a tray from the thermoformable film; and

[0177] Thermally sealing the capping film to the tray.

[0178] Method Embodiment B: The method according to Method Embodiment A, wherein thermoforming the tray comprises thermoforming a blister pack tray.

[0179] Method Embodiment C: The method according to Method Embodiment A or B, further comprising placing a product in the tray before thermally sealing the capping film to the tray.

[0180] Blister Pack Embodiment A: A blister pack comprising:

[0181] A tray thermoformed from the thermoformable film of a system according to any of the preceding system embodiments; and

[0182] A capping sealed to the tray, wherein the capping is formed from the capping film of a system according to any of the preceding system embodiments.

[0183] Blister Pack Embodiment B: The blister pack according to Blister Pack Embodiment A, wherein the capping has no score lines or weak lines.

[0184] Blister Pack Embodiment C: The blister pack according to Blister Pack Embodiment A or B, further comprising a product sealed between the tray and the capping.

[0185] Blister pack embodiment D: The blister pack according to blister pack embodiment C, wherein the product can be easily pushed through the lid.

Claims

1. A system for forming a blister package, the system comprising: A thermoformable film, the thermoformable film comprising a thermoformable film outer layer and a thermoformable film inner layer, The thermoformable film outer layer comprising at least 50 wt% polypropylene, The thermoformable film inner layer comprising at least 50 wt% polypropylene and (a) a tackifier and / or (b) a cycloolefin copolymer; and A capping film, the capping film comprising a capping film outer layer, a capping film inner layer and a sealing layer, The capping film outer layer comprising at least 50% polypropylene, The capping film inner layer comprising at least 50% polypropylene and a tackifier, The sealing layer comprising a polyolefin plastomer.

2. The system according to claim 1, wherein the thermoformable film inner layer comprises at least 5 wt% of the tackifier.

3. The system according to claim 1, wherein the thermoformable film inner layer comprises 5 wt% to 40 wt% of the tackifier.

4. The system according to claim 1, wherein the thermoformable film inner layer comprises 10 wt% to 25 wt% of the tackifier.

5. The system according to claim 1, wherein the thermoformable film inner layer comprises 15 wt% to 20 wt% of the tackifier.

6. The system according to claim 1, wherein the thermoformable film inner layer further comprises a crosslinking agent.

7. The system according to claim 6, wherein the thermoformable film inner layer comprises 0.5 wt% to 5 wt% of the crosslinking agent.

8. The system according to claim 6, wherein the thermoformable film inner layer comprises 1% to 3% of the crosslinking agent.

9. The system according to any one of claims 6 to 8, wherein the crosslinking agent is an ionic crosslinking agent.

10. The system according to claim 1, wherein the thermoformable film inner layer comprises 5 wt% to 40 wt% of the cycloolefin copolymer.

11. The system according to claim 1, wherein the thermoformable film outer layer further comprises a polyolefin elastomer.

12. The system according to claim 11, wherein the polyolefin elastomer comprises an ethylene-propylene random copolymer.

13. The system according to claim 1, wherein the capping film outer layer further comprises a cycloolefin copolymer.

14. The system according to claim 13, wherein the capping film outer layer comprises 5 wt% to 50 wt% of the cycloolefin copolymer.

15. The system according to claim 1, wherein the sealing layer further comprises a polypropylene copolymer.

16. The system according to claim 1, wherein the polyolefin plastomer of the sealing layer comprises an ethylene-propylene random copolymer.

17. A method, comprising: Providing the system according to claim 1; Thermoforming a tray from the thermoformable film; and Thermally sealing the capping film to the tray.

18. The method according to claim 17, wherein thermoforming the tray comprises thermoforming a blister pack tray.

19. The method according to claim 17 or claim 18, further comprising placing a product in the tray before thermally sealing the capping film to the tray.

20. A blister pack, comprising: A tray, the tray being thermoformed from the thermoformable film of the system according to claim 1; and A lid, the lid being sealed to the tray, wherein the lid is formed from the lid film of the system according to claim 1.

21. The blister pack according to claim 20, wherein the lid has no score lines or weakened lines.

22. The blister pack according to claim 20 or 21, further comprising a product, the product being sealed between the tray and the lid.

23. The blister pack according to claim 22, wherein the product can be easily pushed through the lid.

Images